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Sample records for adipic acid dihydrazide

  1. Effect of adipic dihydrazide modification on the performance of collagen/hyaluronic acid scaffold.

    PubMed

    Zhang, Ling; Xiao, Yumei; Jiang, Bo; Fan, Hongsong; Zhang, Xingdong

    2010-02-01

    Collagen and hydrazide-functionalized hyaluronic acid derivatives were hybridized by gelating and genipin crosslinking to form composite hydrogel. The study contributed to the understanding of the effects of adipic dihydrazide modification on the physicochemical and biological properties of the collagen/hyaluronic acid scaffold. The investigation included morphology observation, mechanical measurement, swelling evaluation, and collagenase degradation. The results revealed that the stability of composites was increased through adipic dihydrazide modification and genipin crosslinking. The improved biocompatibility and retention of hyaluronic acid made the composite material more favorable to chondrocytes growing, suggesting the prepared scaffold might be high potential for chondrogenesis.

  2. Injectable oxidized hyaluronic acid/adipic acid dihydrazide hydrogel for nucleus pulposus regeneration.

    PubMed

    Su, Wen-Yu; Chen, Yu-Chun; Lin, Feng-Huei

    2010-08-01

    Injectable hydrogel allows irregular surgical defects to be completely filled, lessens the risk of implant migration, and minimizes surgical defects due to the solution-gel state transformation. Here, we first propose a method for preparing oxidized hyaluronic acid/adipic acid dihydrazide (oxi-HA/ADH) injectable hydrogel by chemical cross-linking under physiological conditions. Fourier transform infrared spectrometry and trinitrobenzene sulfonate assay were used to confirm the oxidation of hyaluronic acid. Rheological properties were measured to evaluate the working ability of the hydrogel for further clinical application. The oxi-HA/ADH in situ forming hydrogel can transform from liquid form into a gel-like matrix within 3-8 min, depending on the operational temperature. Furthermore, hydrogel degradation and cell assessment is also a concern for clinical application. Injectable oxi-HA/ADH8 hydrogel can maintain its gel-like state for at least 5 weeks with a degradation percentage of 40%. Importantly, oxi-HA/ADH8 hydrogel can assist in nucleus pulposus cell synthesis of type II collagen and aggrecan mRNA gene expression according to the results of real-time PCR analysis, and shows good biocompatibility based on cell viability and cytotoxicity assays. Based on the results of the current study, oxi-HA/ADH hydrogel may possess several advantages for future application in nucleus pulposus regeneration.

  3. An injectable oxidated hyaluronic acid/adipic acid dihydrazide hydrogel as a vitreous substitute.

    PubMed

    Su, Wen-Yu; Chen, Ko-Hua; Chen, Yu-Chun; Lee, Yen-Hsien; Tseng, Ching-Li; Lin, Feng-Huei

    2011-01-01

    Vitrectomy is a common procedure for treating ocular-related diseases. The surgery involves removing the vitreous humor from the center of the eye, and vitreous substitutes are needed to replace the vitreous humor after vitrectomy. In the present study, we developed a colorless, transparent and injectable hydrogel with appropriate refractive index as a vitreous substitute. The hydrogel is formed by oxidated hyaluronic acid (oxi-HA) cross-linked with adipic acid dihydrazide (ADH). Hyaluronic acid (HA) was oxidized by sodium periodate to create aldehyde functional groups, which could be cross-linked by ADH. The refractive index of this hydrogel ranged between 1.3420 and 1.3442, which is quite similar to human vitreous humor (1.3345). The degradation tests demonstrated that the hydrogel could maintain the gel matrix over 35 days, depending on the ADH concentration. In addition, the cytotoxicity was evaluated on retina pigmented epithelium (RPE) cells cultivated following the ISO standard (tests for in vitro cytotoxicity), and the hydrogel was found to be non-toxic. In a preliminary animal study, the oxi-HA/ADH hydrogel was injected into the vitreous cavity of rabbit eyes. The evaluations of slit-lamp observation, intraocular pressure, cornea thickness and histological examination showed no significant abnormal biological reactions for 3 weeks. This study suggests that the injectable oxi-HA/ADH hydrogel should be a potential vitreous substitute.

  4. Structure and spectroscopic studies of homo-and heterometallic complexes of adipic acid dihydrazide.

    PubMed

    Jeragh, Bakir; El-Asmy, Ahmed A

    2014-05-05

    A single crystal of adipic acid dihydrazide, ADH, has been analyzed. Its reaction with Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Hg(2+), Ag(+), Pd(2+) and/or Pt(2+) gave homometallic and heterometallic complexes which are characterized by partial elemental analysis, spectra (MS, ESR, (1)H NMR, electronic; IR), thermal analysis and magnetic measurements. Some complexes: Zn(0.73)Cu(ADH)Cl4·H2O; Zn(0.71)Hg(0.36)(ADH)Cl4·H2O; Zn(0.65)Cd(0.46)(ADH)Cl4·½H2O; Zn(0.75)Co(0.41)(ADH-2H)Cl2·3H2O; Cd0.85Co0.43(ADH)Cl4·½EtOH were isolated having nonstiochiometric metal ratios. The ligand behaves as a neutral (bidentate or tetradentate) and/or binegative tetradentate. A square-pyramid, square-planar and tetrahedral structures were proposed for the homo Co(II), Cu(II) and Ni(II) complexes, respectively. A similar and different stereochemistry around each metal ion (tetrahedral+tetrahedral; tetrahedral+square-planar; tetrahedral+tetrahedral and/or tetrahedral+octahedral) was suggested for the heterometallic complexes. Some complexes were found highly stable with stability point >240 °C; the most stable is [HgNi(ADH-2H)Cl2]. The presence of diamagnetic atom (Zn, Cd or Hg) reduces the magnetic moments and gave anomalous moments. The degradation steps and the hydrated complexes are confirmed through the TGA study. The order of covalency of [Zn(0.73)Cu(ADH)Cl4]·H2O, [CdCu(ADH)Cl4]·H2O and [HgCu(ADH-2H)Cl2] matches with the size of the second metal (Zn complex>Cd complex>Hg complex). Some heterometallic complexes were found nonstoichiometric through the analysis of their metal content and supported by TGA.

  5. Structure and spectroscopic studies of homo-and heterometallic complexes of adipic acid dihydrazide

    NASA Astrophysics Data System (ADS)

    Jeragh, Bakir; El-Asmy, Ahmed A.

    A single crystal of adipic acid dihydrazide, ADH, has been analyzed. Its reaction with Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Ag+, Pd2+ and/or Pt2+ gave homometallic and heterometallic complexes which are characterized by partial elemental analysis, spectra (MS, ESR, 1H NMR, electronic; IR), thermal analysis and magnetic measurements. Some complexes: Zn0.73Cu(ADH)Cl4·H2O; Zn0.71Hg0.36(ADH)Cl4·H2O; Zn0.65Cd0.46(ADH)Cl4·½H2O; Zn0.75Co0.41(ADH-2H)Cl2·3H2O; Cd0.85Co0.43(ADH)Cl4·½EtOH were isolated having nonstiochiometric metal ratios. The ligand behaves as a neutral (bidentate or tetradentate) and/or binegative tetradentate. A square-pyramid, square-planar and tetrahedral structures were proposed for the homo Co(II), Cu(II) and Ni(II) complexes, respectively. A similar and different stereochemistry around each metal ion (tetrahedral + tetrahedral; tetrahedral + square-planar; tetrahedral + tetrahedral and/or tetrahedral + octahedral) was suggested for the heterometallic complexes. Some complexes were found highly stable with stability point >240 °C; the most stable is [HgNi(ADH-2H)Cl2]. The presence of diamagnetic atom (Zn, Cd or Hg) reduces the magnetic moments and gave anomalous moments. The degradation steps and the hydrated complexes are confirmed through the TGA study. The order of covalency of [Zn0.73Cu(ADH)Cl4]·H2O, [CdCu(ADH)Cl4]·H2O and [HgCu(ADH-2H)Cl2] matches with the size of the second metal (Zn complex > Cd complex > Hg complex). Some heterometallic complexes were found nonstoichiometric through the analysis of their metal content and supported by TGA.

  6. Adipic acid dihydrazide treated partially oxidized alginate beads for sustained oral delivery of flurbiprofen.

    PubMed

    Maiti, Sabyasachi; Singha, Kamalika; Ray, Somasree; Dey, Paramita; Sa, Biswanath

    2009-01-01

    In this study, periodate oxidation of sodium alginate was controlled such that the oxidized alginate could form isolatable beads with Ca(+2) ions. The beads of oxidized alginate having a degree of oxidation 1 mol%, entrapped 89% flurbiprofen and released almost all of its content within 1.5 h in pH 7.2 phosphate buffer solution. The beads were covalently crosslinked with adipic dihydrazide (ADH) in addition to ionic crosslinks and were characterized. Scanning electron microscopy revealed that the beads were spherical having smooth surfaces. The drug entrapment efficiency decreased (90-86%) with increasing concentration of ADH (2-6% w/v) in the gelation medium. However, the beads prolonged the drug release in alkaline dissolution medium up to 8 h depending upon the concentration of ADH. The beads prepared with 2% ADH swelled more rapidly and led to faster drug release in either pH 1.2 HCl solution or pH 7.2 phosphate buffer solution. The swelling tendencies were reduced and the drug release became slower with higher concentrations in either fluid. The drug diffusion from the beads followed super case II transport mechanism. FTIR spectroscopy indicated stable nature of flurbiprofen in the beads and therefore had potential as sustained oral delivery system for the drug.

  7. The mechanics of hyaluronic acid/adipic acid dihydrazide hydrogel: towards developing a vessel for delivery of preadipocytes to native tissues.

    PubMed

    Shoham, Naama; Sasson, Aviad Levi; Lin, Feng-Huei; Benayahu, Dafna; Haj-Ali, Rami; Gefen, Amit

    2013-12-01

    Promising treatment approaches in repairing tissue defects include implementation of regenerative medicine strategies, particularly delivery of preadipocytes to sites where adipose tissue damage needs to be repaired or where fat needs to be generated. In this study, we suggest that the injectable hyaluronic acid/adipic acid dihydrazide (HA/ADH) hydrogel may be an adipose-tissue-like material in terms of biological compatibility as well as mechanical behavior. First, we show that the hydrogel enables and supports growth, proliferation and differentiation of 3T3-L1 preadipocytes. Second, given that adipose tissue is a weight-bearing biological structure, we investigate the large deformation mechanical behavior of the hydrogel with and without embedded preadipocytes, by performing confined and unconfined compression tests and then calibrating a strain energy density (SED) function to the results. Four test groups were examined: (1) Hydrogel specimens right after the preparation without cells, (2) and (3) 3-days-cultured hydrogel specimens with and without cells, respectively, and (4) 6-days-cultured hydrogel specimens with cells. A one-term Ogden SED was found to adequately describe the hyperelastic behavior of the hydrogel specimens in all experimental groups. Importantly, we found that the mechanical properties of the hydrogel, when subjected to compression, are in good agreement with those of native adipose tissue, with the better fit occurring 3-6 days after preparation of the hydrogel. Third, computational finite element studies of the mechanical (stress-strain) behavior of the HA/ADH hydrogel when containing mature adipocytes indicated that the stiffnesses of the constructs were mildly affected by the presence of the adipocytes. Hence, we conclude that injectable HA/ADH hydrogel may serve as a vessel for protecting preadipocytes during, and at a short-term after delivery to native tissues, e.g. in research towards regenerative medicine in tissue reconstructions.

  8. Toxicity of adipic acid.

    PubMed

    Kennedy, Gerald L

    2002-05-01

    Adipic acid has very low acute toxicity in rats with an LD50 > 5000 mg/kg. Adipic acid produced mild to no skin irritation on intact guinea pig skin as a 50% concentration in propylene glycol; it was not a skin sensitizer. Adipic acid caused mild conjunctival irritation in washed rabbit eyes; in unwashed rabbit eyes, there was mild conjunctival irritation, minimal iritis, but no corneal effects. Adipic acid dust may irritate the mucous membranes of the lungs and nose. In a 2-year feeding study, rats fed adipic acid at concentrations up to 5% in the diet exhibited only weight loss. Adipic acid is not genetically active in a wide variety of assay systems. Adipic acid caused no developmental toxicity in mice, rats, rabbits, or hamsters when administered orally. Adipic acid is partially metabolized in humans; the balance is eliminated unchanged in the urine. Adipic acid is slightly to moderately toxic to fish, daphnia, and algae in acute tests.

  9. [Biosynthesis of adipic acid].

    PubMed

    Han, Li; Chen, Wujiu; Yuan, Fei; Zhang, Yuanyuan; Wang, Qinhong; Ma, Yanhe

    2013-10-01

    Adipic acid is a six-carbon dicarboxylic acid, mainly for the production of polymers such as nylon, chemical fiber and engineering plastics. Its annual demand is close to 3 million tons worldwide. Currently, the industrial production of adipic acid is based on the oxidation of aromatics from non-renewable petroleum resources by chemo-catalytic processes. It is heavily polluted and unsustainable, and the possible alternative method for adipic acid production should be developed. In the past years, with the development of synthetic biology and metabolic engineering, green and clean biotechnological methods for adipic acid production attracted more attention. In this study, the research advances of adipic acid and its precursor production are reviewed, followed by addressing the perspective of the possible new pathways for adipic acid production.

  10. Syngas route to adipic acid

    SciTech Connect

    Kealing, H.S.

    1986-03-01

    In an era of escalating hydrocarbon prices, the development of new technology to synthesize large volume chemical intermediates from the least expensive sources of carbon and hydrogen has been a research area of increasing intensity. Adipic acid is prepared commercially by oxidative processes using either benzene or phenol as the raw material base. Since both benzene and phenol prices track with the price of crude oil, future adipic acid price will increase as the oil reserve decreases. Thus, there is a need for a new process to produce adipic acid from cheap, and readily available, raw materials such as butadiene obtained as a by-product from world scale olefin plants. One such process that capitalizes on the use of butadiene as a raw material is BASF's two-step carbonylation route to adipic acid. The butadiene in the C/sub 4/ cut from a steam cracker is transformed by a two-stage carbonylation with carbon monoxide and methanol into adipic acid dimethyl ester. Hydrolysis converts the ester into adipic acid. BASF is now engineering a 130 mm pound per year commercial plant based on this technology.

  11. 21 CFR 582.1009 - Adipic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Adipic acid. 582.1009 Section 582.1009 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1009 Adipic acid. (a) Product. Adipic acid. (b) (c) Limitations, restrictions, or explanation....

  12. 21 CFR 582.1009 - Adipic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Adipic acid. 582.1009 Section 582.1009 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1009 Adipic acid. (a) Product. Adipic acid. (b) (c) Limitations, restrictions, or explanation....

  13. 21 CFR 582.1009 - Adipic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Adipic acid. 582.1009 Section 582.1009 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1009 Adipic acid. (a) Product. Adipic acid. (b) (c) Limitations, restrictions, or explanation....

  14. 21 CFR 582.1009 - Adipic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Adipic acid. 582.1009 Section 582.1009 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1009 Adipic acid. (a) Product. Adipic acid. (b) (c) Limitations, restrictions, or explanation....

  15. 21 CFR 582.1009 - Adipic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Adipic acid. 582.1009 Section 582.1009 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1009 Adipic acid. (a) Product. Adipic acid. (b) (c) Limitations, restrictions, or explanation....

  16. 21 CFR 184.1009 - Adipic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Adipic acid. 184.1009 Section 184.1009 Food and... Substances Affirmed as GRAS § 184.1009 Adipic acid. (a) Adipic acid (C6H10O4, CAS Reg. No. 00124-04-9) is also known as 1,4-butanedicarboxylic acid or hexane-dioic acid. It is prepared by nitric acid...

  17. 21 CFR 184.1009 - Adipic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Adipic acid. 184.1009 Section 184.1009 Food and... Substances Affirmed as GRAS § 184.1009 Adipic acid. (a) Adipic acid (C6H10O4, CAS Reg. No. 00124-04-9) is also known as 1,4-butanedicarboxylic acid or hexane-dioic acid. It is prepared by nitric acid...

  18. 21 CFR 184.1009 - Adipic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Adipic acid. 184.1009 Section 184.1009 Food and... Substances Affirmed as GRAS § 184.1009 Adipic acid. (a) Adipic acid (C6H10O4, CAS Reg. No. 00124-04-9) is also known as 1,4-butanedicarboxylic acid or hexane-dioic acid. It is prepared by nitric acid...

  19. 21 CFR 184.1009 - Adipic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Adipic acid. 184.1009 Section 184.1009 Food and....1009 Adipic acid. (a) Adipic acid (C6H10O4, CAS Reg. No. 00124-04-9) is also known as 1,4-butanedicarboxylic acid or hexane-dioic acid. It is prepared by nitric acid oxidation of cyclohexanol...

  20. 21 CFR 184.1009 - Adipic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Adipic acid. 184.1009 Section 184.1009 Food and... Substances Affirmed as GRAS § 184.1009 Adipic acid. (a) Adipic acid (C6H10O4, CAS Reg. No. 00124-04-9) is also known as 1,4-butanedicarboxylic acid or hexane-dioic acid. It is prepared by nitric acid...

  1. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-dihydrazide (PMNs P-01-759 and P-05-555; CAS No. 4080-98-2) is subject to reporting under this section for the... equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  2. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-dihydrazide (PMNs P-01-759 and P-05-555; CAS No. 4080-98-2) is subject to reporting under this section for the... equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  3. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-dihydrazide (PMNs P-01-759 and P-05-555; CAS No. 4080-98-2) is subject to reporting under this section for the... equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  4. Adipic acid enhanced limestone flue gas desulfurization process - an assessment

    SciTech Connect

    Mobley, J.D.; Chang, J.C.S.

    1981-12-01

    Adipic acid, when used as an additive in a limestone FGD system, greatly increases both SO/sub 2/ removal and limestone utilization. Most existing limestone scrubbers would benefit from adipic acid addition without major process changes. No significant operating problems or adverse environmental impacts have been identified. The adipic acid enhanced system is economically attractive. Waste dibasic acids and glycolic acid appear to provide benefits similar to adipic acid at a lower cost.

  5. A "hidden" co-crystal of caffeine and adipic acid.

    PubMed

    Bucar, Dejan-Kresimir; Henry, Rodger F; Lou, Xiaochun; Borchardt, Thomas B; Zhang, Geoff G Z

    2007-02-07

    Co-crystal formation between caffeine and adipic acid has been explored over the years without success; utilizing the newly developed co-crystal screening method, we have finally discovered this "hidden" caffeine and adipic acid co-crystal.

  6. Benzene-free synthesis of adipic acid.

    PubMed

    Niu, Wei; Draths, K M; Frost, J W

    2002-01-01

    Strains of Escherichia coli were constructed and evaluated that synthesized cis,cis-muconic acid from D-glucose under fed-batch fermentor conditions. Chemical hydrogenation of the cis,cis-muconic acid in the resulting fermentation broth has also been examined. Biocatalytic synthesis of adipic acid from glucose eliminates two environmental concerns characteristic of industrial adipic acid manufacture: use of carcinogenic benzene and benzene-derived chemicals as feedstocks and generation of nitrous oxide as a byproduct of a nitric acid catalyzed oxidation. While alternative catalytic syntheses that eliminate the use of nitric acid have been developed, most continue to rely on petroleum-derived benzene as the ultimate feedstock. In this study, E. coli WN1/pWN2.248 was developed that synthesized 36.8 g/L of cis,cis-muconic acid in 22% (mol/mol) yield from glucose after 48 h of culturing under fed-batch fermentor conditions. Optimization of microbial cis,cis-muconic acid synthesis required expression of three enzymes not typically found in E. coli. Two copies of the Klebsiella pneumoniae aroZ gene encoding DHS dehydratase were inserted into the E. coli chromosome, while the K. pneumoniae aroY gene encoding PCA decarboxylase and the Acinetobacter calcoaceticus catA gene encoding catechol 1,2-dioxygenase were expressed from an extrachromosomal plasmid. After fed-batch culturing of WN1/pWN2.248 was complete, the cells were removed from the broth, which was treated with activated charcoal and subsequently filtered to remove soluble protein. Hydrogenation of the resulting solution with 10% Pt on carbon (5% mol/mol) at 3400 kPa of H2 pressure for 2.5 h at ambient temperature afforded a 97% (mol/mol) conversion of cis,cis-muconic acid into adipic acid.

  7. Urea-adipic acid (2/1).

    PubMed

    Chang, Hai-Sheng; Lin, Jian-Li

    2011-06-01

    The asymmetric unit of the title co-crystal, 2CH(4)N(2)O·C(6)H(10)O(4), contains two urea mol-ecules and two half-mol-ecules of adipic acid; the latter are completed by crystallographic inversion symmetry. The crystal packing is stabilized by O-H⋯O and N-H⋯O hydrogen bonds, generating a chain along [110]. Additional weak inter-chain O-H⋯O and N-H⋯O inter-molecular inter-actions lead to the formation of a three-dimensional network.

  8. Toward biotechnological production of adipic acid and precursors from biorenewables.

    PubMed

    Polen, Tino; Spelberg, Markus; Bott, Michael

    2013-08-20

    Adipic acid is the most important commercial aliphatic dicarboxylic acid in the chemical industry and is primarily used for the production of nylon-6,6 polyamide. The current adipic acid market volume is about 2.6 million tons/y and the average annual demand growth rate forecast to stay at 3-3.5% worldwide. Hitherto, the industrial production of adipic acid is carried out by petroleum-based chemo-catalytic processes from non-renewable fossil fuels. However, in the past years, efforts were made to find alternative routes for adipic acid production from renewable carbon sources by biotechnological processes. Here we review the approaches and the progress made toward bio-based production of adipic acid.

  9. Bis(2,6-diamino-pyridinium)-adipate-adipic acid-water (2/1/1/2).

    PubMed

    Karadayı, Nevzat

    2007-12-18

    The crystal structure of the title compound, 2C(5)H(8)N(3) (+)·C(6)H(8)O(4) (2-)·C(6)H(10)O(4)·2H(2)O, consists of amino-pyridinium cations, adipate dianions, adipic acid mol-ecules and disordered solvent water mol-ecules [occupancies 0.50 (4) and 0.50 (4)]. Both the adipate and adipic acid are located across inversion centres. Eight-membered hydrogen-bonded rings exist involving amino-pyridinium and adipate ions. Adipic acid mol-ecules and adipate anions are linked into zigzag supra-molecular chains by O-H⋯O hydrogen bonds.

  10. Alternative control techniques document: Nitric and adipic acid manufacturing plants

    SciTech Connect

    Lazzo, D.W.

    1991-12-01

    The Alternative Control Techniques document describes available control techniques for reducing NOx emission levels from nitric and adipic acid manufacturing plants. The document contains information on the formation of NOx and uncontrolled NOx emissions from nitric and adipic acid plants. The following NOx control techniques for nitric acid plants are discussed: extended absorption, nonselective catalytic reduction (NSCR), and selective catalytic reduction (SCR). The following NOx control techniques for adipic acid plants are discussed: extended absorption and thermal reduction. For each control technique, achievable controlled NOx emission levels, capital and annual costs, cost effectiveness, and environmental and energy impacts are presented.

  11. Metabolic engineering strategies to bio-adipic acid production.

    PubMed

    Kruyer, Nicholas S; Peralta-Yahya, Pamela

    2017-03-30

    Adipic acid is the most industrially important dicarboxylic acid as it is a key monomer in the synthesis of nylon. Today, adipic acid is obtained via a chemical process that relies on petrochemical precursors and releases large quantities of greenhouse gases. In the last two years, significant progress has been made in engineering microbes for the production of adipic acid and its immediate precursors, muconic acid and glucaric acid. Not only have the microbial substrates expanded beyond glucose and glycerol to include lignin monomers and hemicellulose components, but the number of microbial chassis now goes further than Escherichia coli and Saccharomyces cerevisiae to include microbes proficient in aromatic degradation, cellulose secretion and degradation of multiple carbon sources. Here, we review the metabolic engineering and nascent protein engineering strategies undertaken in each of these chassis to convert different feedstocks to adipic, muconic and glucaric acid. We also highlight near term prospects and challenges for each of the metabolic routes discussed.

  12. 40 CFR 721.10295 - IPDI modified isophthalic acid, neopentyl glycol and adipic acid (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., neopentyl glycol and adipic acid (generic). 721.10295 Section 721.10295 Protection of Environment..., neopentyl glycol and adipic acid (generic). (a) Chemical substances and significant new uses subject to... glycol and adipic acid (PMN P-11-591) is subject to reporting under this section for the significant...

  13. 40 CFR 721.10295 - IPDI modified isophthalic acid, neopentyl glycol and adipic acid (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., neopentyl glycol and adipic acid (generic). 721.10295 Section 721.10295 Protection of Environment..., neopentyl glycol and adipic acid (generic). (a) Chemical substances and significant new uses subject to... glycol and adipic acid (PMN P-11-591) is subject to reporting under this section for the significant...

  14. 40 CFR 721.10295 - IPDI modified isophthalic acid, neopentyl glycol and adipic acid (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., neopentyl glycol and adipic acid (generic). 721.10295 Section 721.10295 Protection of Environment..., neopentyl glycol and adipic acid (generic). (a) Chemical substances and significant new uses subject to... glycol and adipic acid (PMN P-11-591) is subject to reporting under this section for the significant...

  15. Dietary adipic acid reduces ammonia emission from swine excreta.

    PubMed

    van Kempen, T A

    2001-09-01

    Adipic acid is only partially catabolized when it is fed to animals, and a portion of it is excreted in urine. The excreted portion may lower urinary pH and, as a result, ammonia emission. The present study tested this hypothesis. In Exp. 1, nursery pigs (n = 14) were fed (for a period of 7 d) either a standard nursery diet or the same diet supplemented with 1% adipic acid to assess effects on urinary pH (collected on d 5 or 6) and in vitro ammonia emission from the collected urine samples that were mixed with control feces. In Exp. 2, grower pigs housed 10 each in one of two chambers were fed a control diet or the same diet supplemented with 1% adipic acid. Ventilated air was quantified and analyzed for ammonia using Fourier transform infrared spectroscopy to determine the effects of feeding 1% adipic acid on ammonia emission. The results from Exp. 1 showed that adipic acid strongly reduced urinary pH (from 7.7 to 5.5, P < 0.05). In vitro ammonia emission from these urine samples was significantly reduced at all the time points evaluated (1, 3, 18, and 46 h with reductions of 94, 93, 70, and 39%, respectively, P < 0.05). Experiment 2 showed that adipic acid supplementation reduced ammonia emission by 25% (P < 0.05), which corresponded to the predicted reduction in ammonia emission based on the reduction in manure pH observed. In conclusion, feeding adipic acid lowers urinary pH and reduces ammonia emission. The reduction in ammonia emission, though, does not correspond to the reduction in urinary pH but corresponds to the reduction in fecal pH as a result of mixing the urine and feces, in which feces act as a strong buffer.

  16. Adipic gets the acid test as flue gas scrubber additive

    SciTech Connect

    Miller, I.R.

    1980-02-11

    The first full-scale demonstration of adipic acid for such use, to be conducted early in the summer of 1980 in a 200 MW power plant burning high-sulfur coal, is designed to clarify the costs and show how to reduce losses of adipic acid via degradation. Adipic acid improves SO/sub 2/ removal by acting as a buffer to limit the pH drop normally occurring at the gas-liquid interface so that the higher SO/sub 2/ concentration in the surface film improves liquid-phase mass transfer; it also promotes higher limestone utilization. Prepared by the Tennessee Valley Authority, a preliminary economic analysis for a 500 MW plant burning 4% sulfur coal indicates that the addition of 1500 ppM of adipic acid (limestone at $7/ton and the acid at $840/ton) would raise SO/sub 2/ removal from 90 to 95%, reduce the total capital investment from $41.5 to $39.5 million, and have a first year revenue requirement of $19.9 million vs. $20.9 million without the acid. The large-scale trial will also help clarify concern over unpleasant odors that have been reported at test sites of the limestone/adipic system; valeric acid has been identified as the cause.

  17. Adipic acid increases plasma lysine but does not improve the efficiency of lysine utilization in swine.

    PubMed

    van Kempen, T A; van Heugten, E; Trottier, N L

    2001-09-01

    Adipic acid, upon catabolism, results in intermediates that bear a structural similarity to lysine degradation products. The objectives of this research were to determine whether adipic acid affects lysine concentrations in plasma and to evaluate whether adipic acid improves the efficiency of lysine utilization in pigs. In Exp. 1, nursery pigs (n = 14) were fed (for a period of 7 d) either a standard nursery diet or the same diet supplemented with 1% adipic acid to assess effects on plasma amino acid concentrations (plasma collected on d 7). In Exp. 2, nursery pigs (n = 56) were fed (for a period of 15 d) either a control diet or the same diet but deficient in either lysine, threonine, or tryptophan with or without supplemental adipic acid to assess the effects of adipic acid on the efficiency of amino acid utilization. The results from Exp. 1 showed that adipic acid increased plasma lysine (by 18%) but not alpha-amino adipic acid, an intermediate in lysine degradation. Experiment 2 demonstrated that adipic acid did not increase the efficiency of utilization of lysine, threonine, or tryptophan. The lack of effects on alpha-amino adipic acid in Exp. 1 and the lack of a positive effect on the efficiency of utilization of lysine, threonine, and tryptophan suggest that adipic acid does not inhibit the mitochondrial uptake of lysine and(or) its degradation in the mitochondrion. It is concluded that feeding adipic acid increases plasma lysine but does not improve the efficiency of lysine utilization.

  18. 40 CFR 721.10339 - Adipic acid, substituted propane, alkyldiol, acrylate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Adipic acid, substituted propane... Significant New Uses for Specific Chemical Substances § 721.10339 Adipic acid, substituted propane, alkyldiol... substance identified generically as adipic acid, substituted propane, alkyldiol, acrylate (PMN P-04-113)...

  19. 40 CFR 721.10339 - Adipic acid, substituted propane, alkyldiol, acrylate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Adipic acid, substituted propane... Significant New Uses for Specific Chemical Substances § 721.10339 Adipic acid, substituted propane, alkyldiol... substance identified generically as adipic acid, substituted propane, alkyldiol, acrylate (PMN P-04-113)...

  20. 40 CFR 721.10339 - Adipic acid, substituted propane, alkyldiol, acrylate (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Adipic acid, substituted propane... Significant New Uses for Specific Chemical Substances § 721.10339 Adipic acid, substituted propane, alkyldiol... substance identified generically as adipic acid, substituted propane, alkyldiol, acrylate (PMN P-04-113)...

  1. Assemblies of cytosine within H-bonded network of adipic acid and citric acid

    NASA Astrophysics Data System (ADS)

    Das, Babulal; Baruah, Jubaraj B.

    2011-08-01

    Adipic acid binds to cytosine to form H-bonded discrete cytosine-cytosinium assemblies embedded in 1D infinite chain of adipic acid, whereas citric acid stabilizes trimeric cytosine-cytosinium assemblies having length of 19.44 Å stabilized between layered structures of citric acid molecules.

  2. 78 FR 20029 - Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-03

    ... AGENCY 40 CFR Part 180 Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic..., polymer with adipic acid, linoleic acid, oleic acid and ricinoleic acid (CAS Reg. No. 1357486-09- 9) when used as an inert ingredient in a pesticide formulation. Advance Polymer Technology submitted a...

  3. FGD improves with adipic acid. [Flue gas desulfurization

    SciTech Connect

    Catalano, L.

    1982-07-01

    The addition of adipic acid to the limestone slurry in wet-scrubbing systems has been shown to enhance SO/sub 2/ collection and limestone utilisation whilst reducing operating costs. The results of demonstration tests carried out for the EPA on utility and industrial plants are presented.

  4. Effect of scrubbing operating conditions on adipic acid degradation. Final report February-August 1980

    SciTech Connect

    Chang, J.C.S.

    1981-02-01

    The report gives results of adipic acid degradation tests at EPA's IERL-RTP limestone SO2 scrubber, to investigate the effects of operating variables on unaccountable adipic acid loss. It was found that: (1) adipic acid degradation could not be totally quenched by only lowering the pH below 5.0; (2) pH change did significantly affect unaccountable adipic acid loss (other factors may increase the adipic acid degradation rate at both high and low pH); (3) an appreciable amount of adipic acid loss was caused by coprecipitation with calcium sulfite; and (4) forced oxidation could aggravate the adipic acid degradation loss even at pH below 5.0. Adipic acid loss could be reduced: at high sulfite concentrations (the adipic acid degradation rate could be decreased by lowering the destructive free radical concentrations by high total sulfite); in the presence of manganous ion at low pH (the metal ion might act as an inhibitor to the oxidative degradation reaction at low pH); and with high natural oxidation (the adipic acid coprecipitation loss might be reduced with the high natural oxidation). Adipic acid degradation (loss) data were compared from four different test facilities. Most of the data also support these conclusions.

  5. 76 FR 7703 - 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4-Butanediol, Adipic Acid, and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-11

    ... AGENCY 40 CFR Part 180 1,4-Benzenedicarboxylic Acid, Dimethyl Ester, Polymer With 1,4- Butanediol, Adipic..., polymer with 1,4-butanediol, adipic acid, and hexamethylene diisocyanate (CAS Reg. No. 55231-08-8... residues of 1,4-benzenedicarboxylic acid, dimethyl ester, polymer with 1,4-butanediol, adipic acid,...

  6. Novel molecular anti-colorectalcancer conjugate:chlorambucil-adipic acid dihydrizide-glutamine.

    PubMed

    Tabasi, Maryam Akhavan; Amanlou, Massoud; Siadat, Seyed Davar; Nourmohammadi, Zahra; Omoomi, Farnoor Davachi; Ebrahimi, Seyed Esmaeil Sadat; Aghasadeghi, Mohammad Reza; Rahimi, Pooneh; Pourhosseini, Sahar; Mehravi, Bita; Ardestani, Mehdi Shafiee

    2013-11-01

    Cancer is one of the most fatal diseases in the world and it has been years that finding new drugs and chemotherapeutic techniques with lowest side effects become one of the most important challenging matters needs really hard efforts. Chlorambucil (CBL), an ancient direct-acting alkylating anticancer agent, is commonly used for initial treatment of some kinds of cancers but the use of CBL is often limited because of the unpleasant side effects due to its lack of specificity for targeting cancer cells. In this research we tried to increase the specificity of CBL by producing a novel conjugate by using glutamine amino acid (Glut). Based on previous studies, poly amines and nitrogen compounds noticeably are used by cancer cells increasingly; therefore we decided to increase the efficiency and specificity of CBL by designing and producing a novel anti cancer conjugate using glutamine amino acid as an uptake enhancer, CBL, and Adipic acid Dihydrazide (ADH) as a spacer and linker. The biological tests were carried out on HT29 colorectal cancer cell line to evaluate its anticancer properties. Biological tests like MTT assay, finding IC50, evaluating the induced mechanism of the death of our novel CBL-Glutamine conjugate on HT29 cells, testing abnormal toxicity of this conjugate on mice in comparison with CBL drug were careid out. We found that not only CBL-Glutamine conjugate preserved its anti cancer property with regard to CBL drug, but also it represent lower abnormal toxicity in mice. Apoptosis was detected as its mechanism of the death. Our present study provides a promising strategy for targeting cancer cells using amino acids nano-conjugate drugs. The future perspectives have also been highlighted in continuing similar and relative researches.

  7. Effect of milling on DSC thermogram of excipient adipic acid.

    PubMed

    Ng, Wai Kiong; Kwek, Jin Wang; Yuen, Aaron; Tan, Chin Lee; Tan, Reginald

    2010-03-01

    The purpose of this research was to investigate why and how mechanical milling results in an unexpected shift in differential scanning calorimetry (DSC) measured fusion enthalpy (Delta(fus)H) and melting point (T(m)) of adipic acid, a pharmaceutical excipient. Hyper differential scanning calorimetry (hyper-DSC) was used to characterize adipic acid before and after ball-milling. An experimental study was conducted to evaluate previous postulations such as electrostatic charging using the Faraday cage method, crystallinity loss using powder X-ray diffraction (PXRD), thermal annealing using DSC, impurities removal using thermal gravimetric analysis (TGA) and Karl Fischer titration. DSC thermograms showed that after milling, the values of Delta(fus)H and T(m) were increased by approximately 9% and 5 K, respectively. Previous suggestions of increased electrostatic attraction, change in particle size distribution, and thermal annealing during measurements did not explain the differences. Instead, theoretical analysis and experimental findings suggested that the residual solvent (water) plays a key role. Water entrapped as inclusions inside adipic acid during solution crystallization was partially evaporated by localized heating at the cleaved surfaces during milling. The correlation between the removal of water and melting properties measured was shown via drying and crystallization experiments. These findings show that milling can reduce residual solvent content and causes a shift in DSC results.

  8. Adipic acid-enhanced limestone flue gas desulfurization system commercial demonstration. [Missouri

    SciTech Connect

    Hargrove, O.W. Jr.; Colley, J.D.; Mobley, J.D.

    1981-01-01

    A full-scale demonstration carried out at Springfield, Mo City Utilities Southwest Power Plant in 1980-1981 on adipic acid enhanced limestone flue gas desulfurization system is reported. The major process findings during the demonstration are discussed. It is found that adipic acid is a viable means for improving SO/sub 2/ removal in scrubbers which are limited from a dissolved alkalinity standpoint. Dibasic acid (a mixture of glutaric, adipic, and succinic acids) is a technically viable alternative to adipic acid. 6 refs.

  9. Buffered flue gas scrubbing system using adipic acid by-product stream

    SciTech Connect

    Lester, J.H. Jr.; Danly, D.E.

    1983-12-27

    A by-product stream from the production of adipic acid from cyclohexane, containing glutaric acid, succinic acid and adipic acid, is employed as a buffer in lime or limestone flue gas scrubbing for the removal of sulfur dioxide from combustion gases.

  10. Phase diagram of a system of adipic, glutaric, and sebacic acids

    NASA Astrophysics Data System (ADS)

    Kolyado, A. V.; Alenova, S. M.; Garkushin, I. K.

    2016-06-01

    Adipic acid-glutaric acid, glutaric acid-sebacic acid, and adipic acid-sebacic acid binary systems are studied, along with an adipic acid-glutaric acid-sebacic acid ternary system. It is shown all of these systems are eutectic. Phase equilibria for the diagram elements of the binary systems and the ternary system are described. It is concluded that the above low-melting compounds can be recommended for use as working bodies in heat accumulators, and for preparing electrolytes used in the thin-layer anodic oxidation of aluminum alloys.

  11. Use of adipic acid to enhance flue gas desulfurization

    SciTech Connect

    Ostroff, N.; Laslo, D.

    1984-01-01

    From a chemical point of view, FGD is an acid-base neutralization reaction where the overall rate is balanced by the dissolution of (limestone) alkali, and the absorption of sulfur dioxide. The former occurs at a solid/liquid interface, and the latter occurs at a liquid/gas interface. The rate of each of these processes is determined by local conditions, notably, pH. The introduction of a buffering agent lowers the pH at the solid-liquid interface, thereby increasing the rate of limestone dissolution, and simultaneously, raises the pH at the liquid/gas interface, thereby increasing the rate of absorption. Studies performed during the past several years have established that adipic acid is the best available choice for application because of its unique combination of physical and chemical properties, and its price and availability. This paper discusses the theory of adipic acid enhancement and the mathematics used to describe these phenomena trace its history from the laboratory through full scale trials.

  12. Adipic and malonic acid aqueous solutions: surface tensions and saturation vapor pressures.

    PubMed

    Riipinen, Ilona; Koponen, Ismo K; Frank, Göran P; Hyvärinen, Antti-Pekka; Vanhanen, Joonas; Lihavainen, Heikki; Lehtinen, Kari E J; Bilde, Merete; Kulmala, Markku

    2007-12-20

    The surface tension of adipic aqueous solutions was measured as a function of temperature (T=278-313 K) and adipic acid mole fraction (X=0.000-0.003) using the Wilhelmy plate method. A parametrization fitted to these data is presented. The evaporation rates of binary water-malonic and water-adipic acid droplets were measured with a TDMA technique at different temperatures (T=293-300 K) and relative humidities (58-80%), and the saturation vapor pressures of subcooled liquid malonic and adipic acids were derived from the data using a binary evaporation model. The temperature dependence of the vapor pressures was obtained as least-squares fits to the derived vapor pressures: ln(Psat,l) (Pa)=220.2389-22634.96/T (K)-26.66767 ln T (K) for malonic acid and ln(Psat,l) (Pa)=140.6704-18230.97/T (K)-15.48011 ln T (K) for adipic acid.

  13. Form II of adipic acid-nicotinohydrazide (1/2).

    PubMed

    Lemmerer, Andreas; Bernstein, Joel; Kahlenberg, Volker

    2012-01-01

    The crystal structure of the title co-crystal, 2C(6)H(7)N(3)O·C(6)H(10)O(4), is a second polymorph, designated form II, of the co-crystal formed between the two mol-ecules [Lemmerer et al. (2011 ▶). CrystEngComm, 13, 55-59]. The asymmetric unit comprises one mol-ecule of nicotinic acid hydrazide, and one half-mol-ecule of adipic acid (the entire mol-ecule is completed by the application of a centre of inversion). In the crystal, mol-ecules assemble into a three-dimensional network of hydrogen bonds, formed by three N-H⋯O hydrogen bonds and one O-H⋯N hydrogen bond. The O-H⋯N hydrogen bond formed between the carboxyl group and the pyridine ring is supported by a C-H⋯O hydrogen bond.

  14. Theoretical interpretation of the line shape of crystalline adipic acid.

    PubMed

    Blaise, Paul; El-Amine Benmalti, Mohamed; Henri-Rousseau, Olivier

    2006-01-14

    A general quantum theoretical approach of the upsilon(X-H) IR line shape of cyclic dimers of weakly H-bonded species in the crystal state is proposed. In this model, the adiabatic approximation (allowing to separate the high-frequency motion from the slow one of the H-bond bridge) is performed for each separate H-bond bridge of the dimer and a strong nonadiabatic correction is introduced into the model via the resonant exchange between the fast-mode excited states of the two moieties. Quantum indirect damping and Fermi resonances are taken into account. The present model reduces satisfactorily to many models in the literature dealing with more special situations. It has been applied to the cyclic dimers of adipic acid in the crystal phase. It correctly fits the experimental line shape of the hydrogenated compound and predicts satisfactorily the evolution in the line shapes with temperature and the change in the line shape with isotopic substitution.

  15. Adipic acid enhanced flue gas desulfurization process for industrial boilers. Volume 2. Technical assessment. Project summary

    SciTech Connect

    Behrens, G.P.; Hargrove, O.W.

    1983-03-01

    The SO/sub 2/ removal efficiency with the adipic acid averaged 94.3% over a 30-day period, representing a significant improvement in the performance of the system using only limestone. Economic calculations for an industrial boiler adipic-acid-enhanced limestone FGD system indicate a slight reduction in both capital and operating expenses relative to a limestone-only system designed for 90% SO/sub 2/ control of 3.5% sulfur coal. The costs are competitive with the dual alkali system. The successful demonstration of the adipic-acid-enhanced limestone system increases the number of demonstrated technologies available to a potential user.

  16. Evaluation of adipic acid addition to a bench-scale Chiyoda Thoroughbred 121 FGD system. Final report

    SciTech Connect

    Behrens, G.P.

    1981-12-01

    An experimental laboratory study testing the effectiveness of adipic acid in the Chiyoda Thoroughbred 121 FGD system has been sponsored by the Electric Power Research Institute. Additionally, economic calculations for the cost effectiveness of usng adipic acid in a commercial scale CT-121 FGD system have been performed. The results of this study indicate that although adipic acid can increase the SO/sub 2/ removal capability of the CT-121 system, it is not an economically attractive process improvement. This result is due to the CT-121 process chemistry which minimizes limestone consumption and sludge volume without the need of adipic acid. These two areas realize major cost savings when adipic is used in a conventional limestone FGD system. The economic evaluation indicates even though a lower gas-side pressue drop is achieved when adipic acid is used, the savings in electrical costs are insufficient to offset the cost of adipic acid.

  17. 40 CFR 721.10395 - Fatty acids, C14-18 and C16-18 unsatd., polymers with adipic acid and triethanolamine, di-Me...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...., polymers with adipic acid and triethanolamine, di-Me sulfate-quaternized. 721.10395 Section 721.10395... Fatty acids, C14-18 and C16-18 unsatd., polymers with adipic acid and triethanolamine, di-Me sulfate... identified as fatty acids, C14-18 and C16-18 unsat., polymers with adipic acid and triethanolamine,...

  18. 40 CFR 721.10395 - Fatty acids, C14-18 and C16-18 unsatd., polymers with adipic acid and triethanolamine, di-Me...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...., polymers with adipic acid and triethanolamine, di-Me sulfate-quaternized. 721.10395 Section 721.10395... Fatty acids, C14-18 and C16-18 unsatd., polymers with adipic acid and triethanolamine, di-Me sulfate... identified as fatty acids, C14-18 and C16-18 unsat., polymers with adipic acid and triethanolamine,...

  19. 40 CFR 721.10395 - Fatty acids, C14-18 and C16-18 unsatd., polymers with adipic acid and triethanolamine, di-Me...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...., polymers with adipic acid and triethanolamine, di-Me sulfate-quaternized. 721.10395 Section 721.10395... Fatty acids, C14-18 and C16-18 unsatd., polymers with adipic acid and triethanolamine, di-Me sulfate... identified as fatty acids, C14-18 and C16-18 unsat., polymers with adipic acid and triethanolamine,...

  20. Bimetallic nanocatalysts for the conversion of muconic acid to adipic acid.

    PubMed

    Thomas, John Meurig; Raja, Robert; Johnson, Brian F G; O'Connell, Timothy J; Sankar, Gopinathan; Khimyak, Tetyana

    2003-05-21

    Adipic acid (2) production currently entails use and generation of environmentally harmful materials: an efficient catalyst, consisting of nanoparticles of Ru10Pt2 anchored within the pores of mesoporous silica, facilitates the production of (2) by hydrogenating muconic acid, that may be derived biocatalytically from D-glucose.

  1. Relationship between adipic acid concentration and the core symptoms of autism spectrum disorders.

    PubMed

    Puig-Alcaraz, Carmen; Fuentes-Albero, Milagros; Cauli, Omar

    2016-08-30

    Dicarboxylic acids are an important source of information about metabolism and potential physiopathological alterations in children with autism spectrum disorders (ASDs). We measured the concentration between dicarboxylic adipic and suberic acids in children with an ASD and typically-developing (TD) children and analyzed any relationships between the severity of the core symptoms of ASDs and other clinical features (drugs, supplements, drugs, or diet). The core symptoms of autism were evaluated using the DSM-IV criteria, and adipic acid and suberic acid were measured in urine samples. Overall, no increase in the concentration of adipic acid in children with ASDs compared to TD children, however when considering vitamin B supplementation in ASD there were significantly increased level of urinary adipic acid in children with an ASD not taking vitamin B supplementation compared to supplemented children or to TD children. No significant difference were observed in suberic acid. Interestingly, the increase in adipic acid concentration was significantly and indirectly correlated with the severity of the deficit in socialization and communication skills in children with an ASD. Therefore, therapeutic treatments aimed at decreasing adipic acid concentration might not be beneficial for treating the core symptoms of ASDs.

  2. Direct biosynthesis of adipic acid from a synthetic pathway in recombinant Escherichia coli.

    PubMed

    Yu, Jia-Le; Xia, Xiao-Xia; Zhong, Jian-Jiang; Qian, Zhi-Gang

    2014-12-01

    The C6 dicarboxylic acid, adipic acid, is an important platform chemical in industry. Biobased production of adipic acid is a promising alternative to the current petrochemical route. Here, we report biosynthesis of adipic acid using an artificial pathway inspired by the reversal of beta-oxidation of dicarboxylic acids. The biosynthetic pathway comprises condensation of acetyl-CoA and succinyl-CoA to form the C6 backbone and subsequent reduction, dehydration, hydrogenation, and release of adipic acid from its thioester. The pathway was first tested in vitro with reconstituted pathway enzymes and then functionally introduced into Escherichia coli for the biosynthesis and excretion of adipic acid into the culture medium. The production titer was increased by approximately 20-fold through the combination of recruiting enzymes that were more suitable to catalyze the synthetic reactions and increasing availability of the condensation substrates. This work demonstrates direct biosynthesis of adipic acid via non-natural synthetic pathway, which may enable its renewable production.

  3. Encapsulating fluorescein using adipic acid self-assembly on the surface of PPI-3 dendrimer.

    PubMed

    Chai, Minghui; Holley, Aaron K; Kruskamp, Michael

    2007-01-14

    A water-soluble self-assembly has been formed by associating adipic acid molecules onto the surface of the third generation poly(propyleneimine) dendrimer and this system has been used to encapsulate fluorescein.

  4. Study on the Effects of Adipic Acid on Properties of Dicyandiamide-Cured Electrically Conductive Adhesive and the Interaction Mechanism

    NASA Astrophysics Data System (ADS)

    Wang, Ling; Wan, Chao; Fu, Yonggao; Chen, Hongtao; Liu, Xiaojian; Li, Mingyu

    2014-01-01

    A small quantity of adipic acid was found to improve the performance of dicyandiamide-cured electrically conductive adhesive (ECA) by enhancing its electrical conductivity and mechanical properties. The mechanism of action of the adipic acid and its effects on the ECA were examined. The results indicated that adipic acid replaced the electrically insulating lubricant on the surface of the silver flakes, which significantly improved the electrical conductivity. Specifically, one of the acidic functional groups in adipic acid reacted with the silver flakes, and an amidation reaction occurred between the other acidic functional group in adipic acid and the dicyandiamide, which participated in the curing reaction. Therefore, adipic acid may act as a coupling agent to improve the overall ECA performance.

  5. Effect of trace metals and sulfite oxidation of adipic acid degradation in FGD systems. Final report Dec 81-May 82

    SciTech Connect

    Jarvis, J.B.; Terry, J.C.; Schubert, S.A.; Utley, B.L.

    1982-12-01

    The report gives results of the measurement of the adipic acid degradation rate in a bench-scale flue gas desulfurization (FGD) system, designed to simulate many of the important aspects of full-scale FGD systems. Results show that the adipic acid degradation rate depends on the sulfite oxidation rate, the adipic acid concentration, the presence of manganese in solution, and temperature. The degradation rate is also affected by pH, but only when manganese is present. Adipic acid degradation products identified in the liquid phase include valeric, butyric, propionic, succinic, and glutaric acids. When manganese was present, the predominant degradation products were succinic and glutaric acids. Analysis of solids from the bench scale tests shows large concentrations of coprecipitated adipic acid in low oxidation sulfite solids. By contrast, low quantities of coprecipitated adipic acid were found in high oxidation gypsum solids.

  6. One-pot room-temperature conversion of cyclohexane to adipic acid by ozone and UV light.

    PubMed

    Hwang, Kuo Chu; Sagadevan, Arunachalam

    2014-12-19

    Nitric acid oxidation of cyclohexane accounts for ~95% of the worldwide adipic acid production and is also responsible for ~5 to 8% of the annual worldwide anthropogenic emission of the ozone-depleting greenhouse gas nitrous oxide (N2O). Here we report a N2O-free process for adipic acid synthesis. Treatment of neat cyclohexane, cyclohexanol, or cyclohexanone with ozone at room temperature and 1 atmosphere of pressure affords adipic acid as a solid precipitate. Addition of acidic water or exposure to ultraviolet (UV) light irradiation (or a combination of both) dramatically enhances the oxidative conversion of cyclohexane to adipic acid.

  7. Boosting one-step conversion of cyclohexane to adipic acid by NO2 and VPO composite catalysts.

    PubMed

    Jian, Jian; You, Kuiyi; Duan, Xuezhi; Gao, Hongxu; Luo, Qing; Deng, Renjie; Liu, Pingle; Ai, Qiuhong; Luo, He'an

    2016-02-25

    We demonstrate VPO composites as efficient catalysts for highly selective oxidation of cyclohexane to adipic acid with NO2. In particular, the Ni-Al-VPO composite catalyst exhibits the striking conversion of cyclohexane (60.6%) and exceptionally high selectivity towards adipic acid (85.0%). Moreover, N2O is an environmentally harmful gas, and its yield in the present process is only 0.03 t/t adipic acid, which is far below that obtained using the industrial method (0.3 t/t adipic acid). This work provides a new strategy for the one-step synthesis of dicarboxylic acids from cycloalkanes.

  8. A limited LCA of bio-adipic acid: manufacturing the nylon-6,6 precursor adipic acid using the benzoic acid degradation pathway from different feedstocks.

    PubMed

    van Duuren, J B J H; Brehmer, B; Mars, A E; Eggink, G; Dos Santos, V A P Martins; Sanders, J P M

    2011-06-01

    A limited life cycle assessment (LCA) was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process. The LCA comprises the biological conversion of the aromatic feedstocks benzoic acid, impure aromatics, toluene, or phenol from lignin to cis, cis-muconic acid, which is subsequently converted to adipic acid through hydrogenation. Apart from the impact of usage of petrochemical and biomass-based feedstocks, the environmental impact of the final concentration of cis, cis-muconic acid in the fermentation broth was studied using 1.85% and 4.26% cis, cis-muconic acid. The LCA focused on the cumulative energy demand (CED), cumulative exergy demand (CExD), and the CO(2) equivalent (CO(2) eq) emission, with CO(2) and N(2) O measured separately. The highest calculated reduction potential of CED and CExD were achieved using phenol, which reduced the CED by 29% and 57% with 1.85% and 4.26% cis, cis-muconic acid, respectively. A decrease in the CO(2) eq emission was especially achieved when the N(2) O emission in the combined biological and chemical process was restricted. At 4.26% cis, cis-muconic acid, the different carbon backbone feedstocks contributed to an optimized reduction of CO(2) eq emissions ranging from 14.0 to 17.4 ton CO(2) eq/ton adipic acid. The bulk of the bioprocessing energy intensity is attributed to the hydrogenation reactor, which has a high environmental impact and a direct relationship with the product concentration in the broth.

  9. X-ray studies of crystalline complexes involving amino acids and peptides. XLIII. Adipic acid complexes of L- and DL-lysine.

    PubMed

    Sharma, Alok; Thamotharan, S; Roy, Siddhartha; Vijayan, M

    2006-03-01

    The asymmetric unit of the DL-lysine complex of adipic acid [bis(DL-lysinium) adipate], 2C6H15N2O2+.C6H8O(4)2-, contains a zwitterionic singly charged lysinium cation and half a doubly charged adipate anion (the complete anion has inversion symmetry). That of the L-lysine complex (lysinium hydrogen adipate), C6H15N2O2+.C6H9O4-, consists of a lysinium cation and a singly charged hydrogen adipate anion. In both structures, the lysinium cations organize into layers interconnected by adipate or hydrogen adipate anions. However, the arrangement of the molecular ions in the layer is profoundly different in the DL- and L-lysine complexes. The hydrogen adipate anions in the L-lysine complex form linear arrays in which adjacent ions are interconnected by a symmetric O...H...O hydrogen bond.

  10. Isolated adipic aciduria.

    PubMed

    Hasbini, D A; Mikati, M A; Habbal, Z M

    2001-01-01

    Adipic acid can appear, in combination with other dicarboxylic acids, in the urine of patients in a number of underlying metabolic diseases. A child with seizures and mental retardation of unknown etiology who was found to have elevated isolated adipic aciduria on investigation for metabolic diseases is reported. A dietary artifact was suspected, and the adipic aciduria resolved after the child was kept on a specific restricted diet for 3 days. This is the third report of isolated adipic aciduria secondary to food. Findings confirm the previous reports of dietary origin of isolated adipic aciduria and should alert clinicians to such artifact before committing patients to unnecessary treatments.

  11. Highly efficient chemical process to convert mucic acid into adipic acid and DFT studies of the mechanism of the rhenium-catalyzed deoxydehydration.

    PubMed

    Li, Xiukai; Wu, Di; Lu, Ting; Yi, Guangshun; Su, Haibin; Zhang, Yugen

    2014-04-14

    The production of bulk chemicals and fuels from renewable bio-based feedstocks is of significant importance for the sustainability of human society. Adipic acid, as one of the most-demanded drop-in chemicals from a bioresource, is used primarily for the large-volume production of nylon-6,6 polyamide. It is highly desirable to develop sustainable and environmentally friendly processes for the production of adipic acid from renewable feedstocks. However, currently there is no suitable bio-adipic acid synthesis process. Demonstrated herein is the highly efficient synthetic protocol for the conversion of mucic acid into adipic acid through the oxorhenium-complex-catalyzed deoxydehydration (DODH) reaction and subsequent Pt/C-catalyzed transfer hydrogenation. Quantitative yields (99 %) were achieved for the conversion of mucic acid into muconic acid and adipic acid either in separate sequences or in a one-step process.

  12. Disorder and twinning in molecular crystals: impurity-induced effects in adipic acid.

    PubMed

    Williams-Seton, L; Davey, R J; Lieberman, H F; Pritchard, R G

    2000-03-01

    The variation in physical properties of crystals grown in the presence of additives or impurities have previously been attributed to lattice disorder developed during crystallization. Adipic acid crystallized in the presence of a variety of stereochemically related impurities typifies such behavior with disorder manifest in variations of dissolution rates and enthalpies of solution and fusion. In this case the most extreme habit, produced by the presence of added monoalkanoic acids, is a rounded dumbbell that was suggested previously to be a twinned crystal. In this contribution such crystals are fully characterized both through their external morphology and by means of single crystal X-ray diffraction. These techniques show that these particles are not twinned but rather are disordered single crystals comprising a small number of slightly misaligned domains. The interaction between additive and substrate is modeled and new additives selected that induce the formation of true mechanical twins in adipic acid.

  13. Capsule report: Adipic acid-enhanced lime/limestone test results at the EPA alkali scrubbing test facility

    SciTech Connect

    Burbank, D.A.; Wang, S.C.

    1982-04-01

    The fifth in a series of reports describing the results of the Shawnee Lime and Limestone Wet Scrubbing Test Program, the report describes the results of adipic acid-enhanced limestone wet scrubbing systems. A primary objective of the program was to enhance sulfur oxide removal and improve the reliability and economics of lime and limestone wet scrubbing systems by use of adipic acid as a chemical additive.

  14. Preparation of Nanocellulose Reinforced Chitosan Films, Cross-Linked by Adipic Acid

    PubMed Central

    Falamarzpour, Pouria; Behzad, Tayebeh; Zamani, Akram

    2017-01-01

    Adipic acid, an abundant and nontoxic compound, was used to dissolve and cross-link chitosan. After the preparation of chitosan films through casting technique, the in situ amidation reaction was performed at 80–100 °C as verified by Fourier transform infrared (FT-IR). The reaction was accompanied by the release of water which was employed to investigate the reaction kinetics. Accordingly, the reaction rate followed the first-order model and Arrhenius equation, and the activation energy was calculated to be 18 kJ/mol. Furthermore, the mechanical properties of the chitosan films were comprehensively studied. First, optimal curing conditions (84 °C, 93 min) were introduced through a central composite design. In order to evaluate the effects of adipic acid, the mechanical properties of physically cross-linked (uncured), chemically cross-linked (cured), and uncross-linked (prepared by acetic acid) films were compared. The use of adipic acid improved the tensile strength of uncured and chemically cross-linked films more than 60% and 113%, respectively. Finally, the effect of cellulose nanofibrils (CNFs) on the mechanical performance of cured films, in the presence of glycerol as a plasticizer, was investigated. The plasticized chitosan films reinforced by 5 wt % CNFs showed superior properties as a promising material for the development of chitosan-based biomaterials. PMID:28208822

  15. Preparation of Nanocellulose Reinforced Chitosan Films, Cross-Linked by Adipic Acid.

    PubMed

    Falamarzpour, Pouria; Behzad, Tayebeh; Zamani, Akram

    2017-02-13

    Adipic acid, an abundant and nontoxic compound, was used to dissolve and cross-link chitosan. After the preparation of chitosan films through casting technique, the in situ amidation reaction was performed at 80-100 °C as verified by Fourier transform infrared (FT-IR). The reaction was accompanied by the release of water which was employed to investigate the reaction kinetics. Accordingly, the reaction rate followed the first-order model and Arrhenius equation, and the activation energy was calculated to be 18 kJ/mol. Furthermore, the mechanical properties of the chitosan films were comprehensively studied. First, optimal curing conditions (84 °C, 93 min) were introduced through a central composite design. In order to evaluate the effects of adipic acid, the mechanical properties of physically cross-linked (uncured), chemically cross-linked (cured), and uncross-linked (prepared by acetic acid) films were compared. The use of adipic acid improved the tensile strength of uncured and chemically cross-linked films more than 60% and 113%, respectively. Finally, the effect of cellulose nanofibrils (CNFs) on the mechanical performance of cured films, in the presence of glycerol as a plasticizer, was investigated. The plasticized chitosan films reinforced by 5 wt % CNFs showed superior properties as a promising material for the development of chitosan-based biomaterials.

  16. Theoretical insights into heme-catalyzed oxidation of cyclohexane to adipic acid.

    PubMed

    Noack, Holger; Georgiev, Valentin; Blomberg, Margareta R A; Siegbahn, Per E M; Johansson, Adam Johannes

    2011-02-21

    Adipic acid is a key compound in the chemical industry, where it is mainly used in the production of polymers. The conventional process of its generation requires vast amounts of energy and, moreover, produces environmentally deleterious substances. Thus, there is interest in alternative ways to gain adequate amounts of adipic acid. Experimental reports on a one-pot iron-catalyzed conversion of cyclohexane to adipic acid motivated a theoretical investigation based on density functional theory calculations. The process investigated is interesting because it requires less energy than contemporary methods and does not produce environmentally harmful side products. The aim of the present contribution is to gain insight into the mechanism of the iron-catalyzed cyclohexane conversion to provide a basis for the further development of this process. The rate-limiting step of the process is discussed, but considering the accuracy of the calculations, it is difficult to ensure whether the rate-limiting step is in the substrate oxidation or in the generation of the catalytically active species. It is shown that the slowest step in the substrate oxidation is the conversion of cyclohexanol to cyclohexane-1,2-diol. Hydrogen-atom transfer from one of the OH groups of cyclohexane-1,2-diol makes the intradiol cleavage occur spontaneously.

  17. Oxidation-resistant acidic resins prepared by partial carbonization as cocatalysts in synthesis of adipic acid.

    PubMed

    Wei, Huijuan; Li, Hongbian; Liu, Yangqing; Jin, Peng; Wang, Xiangyu; Li, Baojun

    2012-08-01

    The oxidation-resistant acidic resins are of great importance for the catalytic oxidation systems. In this paper, the oxidatively stable acidic resins are obtained from the cation ion exchange resins (CIERs) through the thermal treatment in N(2) atmosphere. The structure and properties of the thermally treated CIERs were characterized by chemical analysis, Fourier transform infrared (FT-IR) spectra, acid capacity measurement and scanning electron microscope (SEM). The thermally treated CIERs possess high acid capacity up to 4.09 mmol g(-1). A partial carbonization is observed in the thermal treatment process of CIERs, but the morphology of resin spheres maintains well. The as-prepared CIERs are used as solid acids to assist the hydrogen peroxide oxidation of cyclohexene to adipic acid (ADA) with tungstic acid as the catalyst precursor. The improved yields of ADA in the recycling reaction are obtained in the presence of acidic CIERs. Meanwhile, the unproductive decomposition of H(2)O(2) is effectively suppressed. The high yields of ADA (about 81%) are kept by the thermally treated CIERs even after the fifth cycle. The thermally treated CIERs exhibit excellent acid-catalytic performance and possess remarkable oxidation-resistant capability.

  18. Full-scale utility FGD (flue gas desulfurization) system adipic acid demonstration program. Volume 1. Process results. Final report Jun 80-Nov 82

    SciTech Connect

    Hargrove, O.W. Jr; Colley, J.D.; Glover, R.L.; Owen, M.L.

    1983-06-01

    The report culminates a series of projects sponsored by the EPA, investigating the use of adipic acid as an additive to enhance SO/sub 2/ removal in aqueous flue gas desulfurization (FGD) systems, using limestone reagent. A 9-month program at the 194-MW Southwest Power Plant (SWPP) of City Utilities, Springfield, MO, demonstrated the effectiveness of adipic acid and dibasic acids (the latter, by-products of the production of adipic acid). The program examined the effect of adipic acid addition on a limestone FGD system under natural and forced-oxidation modes of operation.

  19. Full-scale utility FGD (flue gas desulfurization) system adipic acid demonstration program. Volume 2. Continuous emissions monitoring results. Final report Jun 80-Nov 82

    SciTech Connect

    Hargrove, O.W. Jr.; Colley, J.D.; Glover, R.L.; Owen, M.L.

    1983-06-01

    The report culminates a series of projects sponsored by the EPA, investigating the use of adipic acid as an additive to enhance SO/sub 2/ removal in aqueous flue gas desulfurization (FGD) systems, using limestone reagent. A 9-month program at the 194-MW Southwest Power Plant (SWPP) of City Utilities, Springfield, MO, demonstrated the effectiveness of adipic acid and dibasic acids (the latter, by-products of the production of adipic acid). The program examined the effect of adipic acid addition on a limestone FGD system under natural and forced-oxidation modes of operation.

  20. cis,cis-Muconic acid: separation and catalysis to bio-adipic acid for nylon-6,6 polymerization

    SciTech Connect

    Vardon, Derek R.; Rorrer, Nicholas A.; Salvachúa, Davinia; Settle, Amy E.; Johnson, Christopher W.; Menart, Martin J.; Cleveland, Nicholas S.; Ciesielski, Peter N.; Steirer, K. Xerxes; Dorgan, John R.; Beckham, Gregg T.

    2016-01-01

    cis,cis-Muconic acid is a polyunsaturated dicarboxylic acid that can be produced renewably via the biological conversion of sugars and lignin-derived aromatic compounds. Subsequently, muconic acid can be catalytically converted to adipic acid -- the most commercially significant dicarboxylic acid manufactured from petroleum. Nylon-6,6 is the major industrial application for adipic acid, consuming 85% of market demand; however, high purity adipic acid (99.8%) is required for polymer synthesis. As such, process technologies are needed to effectively separate and catalytically transform biologically derived muconic acid to adipic acid in high purity over stable catalytic materials. To that end, this study: (1) demonstrates bioreactor production of muconate at 34.5 g L-1 in an engineered strain of Pseudomonas putida KT2440, (2) examines the staged recovery of muconic acid from culture media, (3) screens platinum group metals (e.g., Pd, Pt, Rh, Ru) for activity and leaching stability on activated carbon (AC) and silica supports, (4) evaluates the time-on-stream performance of Rh/AC in a trickle bed reactor, and (5) demonstrates the polymerization of bio-adipic acid to nylon-6,6. Separation experiments confirmed AC effectively removed broth color compounds, but subsequent pH/temperature shift crystallization resulted in significant levels of Na, P, K, S and N in the crystallized product. Ethanol dissolution of muconic acid precipitated bulk salts, achieving a purity of 99.8%. Batch catalysis screening reactions determined that Rh and Pd were both highly active compared to Pt and Ru, but Pd leached significantly (1-9%) from both AC and silica supports. Testing of Rh/AC in a continuous trickle bed reactor for 100 h confirmed stable performance after 24 h, although organic adsorption resulted in reduced steady-state activity. Lastly, polymerization of bio-adipic acid with hexamethyldiamine produced nylon-6,6 with comparable properties to its petrochemical counterpart

  1. AFM studies of the crystallization and habit modification of an excipient material, adipic acid.

    PubMed

    Keel, T R; Thompson, C; Davies, M C; Tendler, S J B; Roberts, C J

    2004-08-06

    Atomic force microscopy (AFM) has been used to investigate the (1 0 0) face of crystalline adipic acid, both in air and liquid environments. In air, surface reorganization occurred during scanning of the AFM probe, which has been investigated using single point force-distance analysis under a controlled relative humidity (RH) environment. We suggest such reorganization can be attributed to the influence of a network of water molecules bound to the hydrophilic (1 0 0) surface permitting local AFM tip-enhanced dissolution and reorganization of the solute. In situ imaging was also carried out on the crystals, revealing etch-pit formation during dissolution, and rapid growth at higher levels of supersaturation (sigma), both of which are direct consequences of the hydrophilic nature of the (1 0 0) face. Also presented here are nanoscale observations of the effect of octanoic acid, a structurally-related habit modifier, on crystalline adipic acid. Using AFM, we have been able to show that the presence of octanoic acid at low concentration has little observable affect on the development of the (1 0 0) face; however, as this concentration is increased, there are clear changes in step morphology and growth mode on the (1 0 0) face of the crystal. At a concentration of 1.26 mmol dm(-3) (a concentration corresponding to a molar ratio of approximately 1:175 octanoic acid:adipic acid), growth on the (1 0 0) face is inhibited, with in situ AFM imaging indicating this is a direct consequence of octanoic acid binding to the surface, and pinning the monomolecular growth steps.

  2. Synthesis and characterization of copolyanhydrides of carbohydrate-based galactaric acid and adipic acid.

    PubMed

    Mehtiö, Tuomas; Nurmi, Leena; Rämö, Virpi; Mikkonen, Hannu; Harlin, Ali

    2015-01-30

    A series of copolyanhydrides, consisting of 2,3,4,5-tetra-O-acetylgalactaric acid (AGA) and adipic acid (AA) as monomer units, was polymerized. Synthesis of AGA monomer consisted of two steps. First, O-acetylation of galactaric acid secondary hydroxyl groups was performed using acetic anhydride as a reagent. Acetic anhydride was then further used as a reagent in the synthesis of diacetyl mixed anhydride of AGA. Polymerizations were conducted as bulk condensation polymerization at 150 °C. Thermal properties of the copolymers varied depending on monomer composition. Increase in the AGA content had a clear increasing effect on the Tg. A similar increasing effect was observed in Tm. The degree of crystallinity decreased as AGA content increased. There was a slightly lowering tendency in the molecular weights of the obtained polymers when the AGA content in the polymerization mixtures increased. The described synthesis route shows that bio-based aldaric acid monomers are potential candidates for the adjustment of thermal properties of polyanhydrides.

  3. Correlation of hydrolytic degradation with structure for copolyesters produced from glycolic and adipic acids.

    PubMed

    Simitzis, J; Triantou, D; Soulis, S; Triantou, K; Simitzis, Ch; Zoumpoulakis, L

    2010-04-01

    Copolyesters based on glycolic acid (G) combined with adipic acid (A) and ethylene glycol (E) were synthesized in different percentage of molar ratios (A: 100-50% and G: 100%) and their hydrolytic degradation was studied and correlated with their structures. According to the DSC, the production of polyesters leads to the formation of copolyesters and not to mixtures of homopolyesters. The crystallites in the copolyesters mainly consist of continuous sequences of ethylene adipate structural units. The hydrolytic degradation of the polyesters was followed by their weight loss during hydrolysis and by the FTIR spectra of the initial polyesters compared with that of the degraded polyesters at equilibrium. The region between 1142 and 800 cm(-1) can be utilized to evaluate the extent of degradation of polyesters after their hydrolysis. The absorption bands at 1142, 1077 and 850 cm(-1) due to the amorphous region decrease after hydrolysis, whereas those at 972, 901 and 806 cm(-1) due to the crystalline region increase. The experimental data of the hydrolytic degradation were fitted with exponential rise to maximum type functions using two-parameter model, which describes very well mainly the initial part of the degradation, and four-parameter model (containing two exponential terms), which is appropriate for fitting the hydrolytic degradation on the entire time period (including the equilibrium). Furthermore, the kinetics of the hydrolytic degradation of the polyesters for the initial time period based on both models results to similar values of the rate constant, k. The synthesized copolyesters of glycolic acid combined with adipic acid and ethylene glycol are soluble in many common organic solvents opposite to PGA, leading to modified biodegradable polyesters and therefore they can be easily processed.

  4. Adipic acid enhanced flue gas desulfurization process for industrial boilers: Volume 1. Field test results. Project summary

    SciTech Connect

    Clarke, P.A.; Gerstle, R.W.; Henzel, D.S.; Mason, K.W.; Sabatini, S.R.

    1983-03-01

    Test results show that adding adipic acid to the limestone slurry significantly improved the SO/sub 2/ removal efficiency of the FGD system. Limited baseline data on operations with limestone only indicated a performance level of 55% SO/sub 2/ removal. Adding about 2200 ppM of adipic acid to the limestone scrubbing systems, the unit's level of performance increased to an average of 94.3% SO/sub 2/ removal which was maintained within a standard deviation of 2.2% over a 30-day test period during which boiler load was 70 to 130 million Btu/hr and gas throughput varied 300%.

  5. Synthesis of C5-tetrazole derivatives of 2-amino-adipic acid displaying NMDA glutamate receptor antagonism.

    PubMed

    Lenda, Fatimazohra; Crouzin, Nadine; Cavalier, Mélanie; Guiramand, Janique; Lanté, Fabien; Barbanel, Gérard; Cohen-Solal, Catherine; Martinez, Jean; Guenoun, Farhate; Lamaty, Frédéric; Vignes, Michel

    2011-03-01

    Five derivatives of 2-amino-adipic acid bearing a tetrazole-substituted in C5 position were synthesized. These compounds displayed selective antagonism towards N-methyl-D: -aspartate (NMDA) receptors compared with AMPA receptors, and they were devoid of any neurotoxicity. Among these five analogues, one exhibited a higher affinity for synaptic NMDA responses than the other four. Therefore, C5 tetrazole-substituted of 2-amino-adipic acid represent an interesting series of new NMDA receptor antagonists. This approach may be considered as a new strategy to develop ligands specifically targeted to synaptic or extra-synaptic NMDA receptors.

  6. Influence of adipic acid on tensile and morphology properties of linear low density polyethylene/rambutan peels flour blends

    NASA Astrophysics Data System (ADS)

    Nadhirah, A. A.; Sam, S. T.; Noriman, N. Z.; Ragunathan, S.; Ismail, H.

    2015-07-01

    This study investigate about the tensile and morphological properties of degradable polymer produced from linear low density polyethylene/rambutan peel flour (LLDPE/RPF) blends and adipic acid (AA) was used as a compatibilizer by varying the rambutan peel flour (RPF) amount from 0-25wt%. The samples were subjected to tensile and morphological tests. AA compatibilized showed higher strength compared to uncompatibilized blends. The Young's modulus for LLDPE/RPF blends increased with increasing flour content. However, the addition of adipic acid had reduced the Young's Modulus.

  7. Engineering a Polyketide Synthase for In Vitro Production of Adipic Acid.

    PubMed

    Hagen, Andrew; Poust, Sean; Rond, Tristan de; Fortman, Jeffrey L; Katz, Leonard; Petzold, Christopher J; Keasling, Jay D

    2016-01-15

    Polyketides have enormous structural diversity, yet polyketide synthases (PKSs) have thus far been engineered to produce only drug candidates or derivatives thereof. Thousands of other molecules, including commodity and specialty chemicals, could be synthesized using PKSs if composing hybrid PKSs from well-characterized parts derived from natural PKSs was more efficient. Here, using modern mass spectrometry techniques as an essential part of the design-build-test cycle, we engineered a chimeric PKS to enable production one of the most widely used commodity chemicals, adipic acid. To accomplish this, we introduced heterologous reductive domains from various PKS clusters into the borrelidin PKS' first extension module, which we previously showed produces a 3-hydroxy-adipoyl intermediate when coincubated with the loading module and a succinyl-CoA starter unit. Acyl-ACP intermediate analysis revealed an unexpected bottleneck at the dehydration step, which was overcome by introduction of a carboxyacyl-processing dehydratase domain. Appending a thioesterase to the hybrid PKS enabled the production of free adipic acid. Using acyl-intermediate based techniques to "debug" PKSs as described here, it should one day be possible to engineer chimeric PKSs to produce a variety of existing commodity and specialty chemicals, as well as thousands of chemicals that are difficult to produce from petroleum feedstocks using traditional synthetic chemistry.

  8. Consecutive visible-light photoredox decarboxylative couplings of adipic acid active esters with alkynyl sulfones leading to cyclic compounds.

    PubMed

    Li, Jingjing; Tian, Hua; Jiang, Min; Yang, Haijun; Zhao, Yufen; Fu, Hua

    2016-07-07

    Novel and efficient consecutive photoredox decarboxylative couplings of adipic acid active esters (bis(1,3-dioxoisoindolin-2-yl)-substituted hexanedioates) with substituted 1-(2-arylethynylsulfonyl)benzenes have been developed under visible-light photocatalysis. The successive photoredox decarboxylative C-C bond formation at room temperature afforded the corresponding cyclic compounds in good yields with tolerance of some functional groups.

  9. Development of a solid-phase extraction method for simultaneous extraction of adipic acid, succinic acid and 1,4-butanediol formed during hydrolysis of poly(butylene adipate) and poly(butylene succinate).

    PubMed

    Lindström, Annika; Albertsson, Ann-Christine; Hakkarainen, Minna

    2004-01-02

    A solid-phase extraction (SPE) method was developed for the simultaneous extraction of dicarboxylic acids and diols formed during hydrolysis of poly(butylene succinate), PBS, and poly(butylene adipate), PBA. Four commercial non-polar SPE columns, three silica based: C8, C18, C18 (EC), and one resin based: ENV+, were tested for the extraction of succinic acid, adipic acid and 1,4-butanediol, the expected final hydrolysis products of PBS and PBA. ENV+ resin was chosen as a solid-phase, because it displayed the best extraction efficiency for 1,4-butanediol and succinic acid. Linear range for the extracted analytes was 1-500 ng/microl for adipic acid and 2-500 ng/microl for 1,4-butanediol and succinic acid. Detection and quantification limits for the analytes were between 1-2 and 2-7 ng/microl, respectively, and relative standard deviations were between 3 and 7%. Good repeatability and low detection limits made the developed SPE method and subsequent gas chromatography-mass spectrometry (GC-MS) analysis a sensitive tool for identification and quantification of hydrolysis products at early stages of degradation.

  10. Magnesium-mediated intramolecular reductive coupling: a stereoselective synthesis of C(2)-symmetric 3,4-bis-silyl-substituted adipic acid derivatives.

    PubMed

    Kundu, Pintu K; Ghosh, Sunil K

    2009-11-21

    Chiral C(2)-symmetric 3,4-bis-silyl-substituted adipic acid derivatives have been synthesised by a Mg/trimethylsilyl chloride-mediated intramolecular reductive coupling of symmetrical disiloxanes of beta-silylacrylic acid N-oxazolidinone derivatives. Efficient and short syntheses of enantiomerically pure enantiomers of 2,6-dioxabicyclo[3.3.0]octane-3,7-dione have been achieved from the bis-silylated adipic acid derivatives using Fleming-Tamao oxidation as the key step.

  11. Continuous-flow synthesis of adipic acid from cyclohexene using hydrogen peroxide in high-temperature explosive regimes.

    PubMed

    Damm, Markus; Gutmann, Bernhard; Kappe, C Oliver

    2013-06-01

    Safe only in a microreactor! The synthesis of adipic acid from cyclohexene by tungstic acid-catalyzed oxidation using hydrogen peroxide following the classical Noyori protocol can be accomplished in good yields with residence times as short as 20 min at 140 °C using a safe and scalable microreactor environment. Under these intensified conditions the use of a phase-transfer catalyst is not required.

  12. The adipic acid enhanced flue gas desulfurization process for industrial boilers. Volume 2. Technical assessment. Final report Feb 81-Feb 82

    SciTech Connect

    Behrens, G.P.; Hargrove, O.W. Jr

    1982-11-01

    The report gives results of an evaluation of an adipic acid enhanced limestone flue gas desulfurization (FGD) system on industrial boilers at Rickenbacker Air National Guard Base. The SO/sub 2/ removal efficiency with the adipic acid averaged 94.3% over a 30-day period. This represents a significant improvement in the performance of the system using only limestone. Economic calculations for an industrial boiler adipic acid enhanced limestone FGD system indicate a slight reduction in both capital and operating expenses relative to a limestone-only system designed for 90% SO2 control of 3.5% sulfur coal. The costs are competitive with those of the dual alkali system. The successful demonstration of the adipic acid enhanced limestone system increases the number of demonstrated technologies available to a potential user.

  13. Highly efficient one-step conversion of cyclohexane to adipic acid using single-site heterogeneous catalysts.

    PubMed

    Raja, Robert; Thomas, John Meurig; Xu, Mingcan; Harris, Kenneth D M; Greenhill-Hooper, Michael; Quill, Kieran

    2006-01-28

    A solid source of 'active' oxygen (acetylperoxyborate, APB), when dissolved in aqueous solution in the presence of a single-site microporous catalyst containing redox centres (Fe(III)AlPO-31, Mn(III)AlPO-5, Fe(III)AlPO-5), converts cyclohexane with high efficiency (ca. 88%) and exceptionally high selectivity (ca. 81%) to adipic acid at 383 K; this procedure is also effective in converting styrene to styrene oxide and -pinene and (+)-limonene to their corresponding epoxides.

  14. Properties of alkali-solubilized collagen solution crosslinked by N-hydroxysuccinimide activated adipic acid

    NASA Astrophysics Data System (ADS)

    Chen, Yihui; Zhang, Min; Liu, Wentao; Li, Guoying

    2011-03-01

    The effect of N-hydroxysuccinimide activated adipic acid (NHS-AA) on the properties of alkali-solubilized collagen solutions was examined. The residual amino group content in crosslinked collagen, determined by trinitrobenzensulfonic acid (TNBS) assay, was decreased with increasing NHS-AA concentration. The results from differential scanning calorimeter (DSC) indicated that the maximum denaturation temperature ( T d) of crosslinked collagen solution was about 4.2°C higher than that of un-crosslinked collagen solution (36.6°C). Moreover, the values of storage modulus ( G'), loss modulus ( G″) and complex viscosity ( η*), obtained by means of dynamic frequency sweeps, were increased as NHS-AA concentration added up to 1.5 mM, and then decreased slightly when further increased NHS-AA concentration. Besides, for collagen solution crosslinked with 1.5 mM NHS-AA, dynamic denaturation temperature ( T dd) was about 1.1°C lower than T d (40.8°C), and the Arrhenius-type time-temperature superposition (TTS) principle was applied to yield the activation energy to be 474.4 kJmol-1.

  15. Effects of strong inter-hydrogen bond dynamical couplings in the polarized IR spectra of adipic acid crystals

    NASA Astrophysics Data System (ADS)

    Flakus, Henryk T.; Tyl, Aleksandra; Jablońska, Magdalena

    2009-10-01

    This paper presents the results of the re-investigation of polarized IR spectra of adipic acid and of its d2, d8 and d10 deuterium derivative crystals. The spectra were measured at 77 K by a transmission method using polarized light for two different crystalline faces. Theoretical analysis concerned linear dichroic effects and H/D isotopic effects observed in the spectra of the hydrogen and deuterium bonds in adipic acid crystals at the frequency ranges of the νO-H and the νO-D bands. The two-branch fine structure pattern of the νO-H and νO-D bands and the basic linear dichroic effects characterizing them were ascribed to the vibronic mechanism of vibrational dipole selection rule breaking for IR transitions in centrosymmetric hydrogen bond dimers. It was proved that for isotopically diluted crystalline samples of adipic acid, a non-random distribution of protons and deuterons occurs in the dimers (H/D isotopic " self-organization" effect). This effect results from the dynamical co-operative interactions involving the dimeric hydrogen bonds.

  16. A study on reactive blending of (poly lactic acid) and poly (butylene succinate co adipate)

    NASA Astrophysics Data System (ADS)

    Bureepukdee, C.; Suttiruengwong, S.; Seadan, M.

    2015-07-01

    This research aims to study the blending of Polylactic acid (PLA) and Polybutylene succinate co adipate (PBSA) in order to understand the role of peroxide in free radical reaction on the compatibilization between these two biodegradable polyesters. Various ratios of PLA/PBSA blends with and without reactive agents were prepared in the twin screw extruder. Two types of peroxides, Di (tert-butylperoxyisopropyl) benzene (DTBP) and 2, 5-Dimethyl-2, 5-(t-butylperoxy) hexane (DTBH), were used with various concentrations to compare. From the torques measurement, DTBP was more reactive with PLA and PBSA than DTBH. PLA and PBSA 80:20, 60:40, 50:50, 40:60, and 20:80% by weight were melt-blended in a twin screw extruder. The reactive polymer blends were also prepared for the same ratios of the blends with addition of 0.08 and 0.1 phr of DTBP. The mechanical, thermal, rheological, and morphological properties were investigated. The impact strengths of the non-reactive blend increased with the increasing in PBSA content. The optimal impact strength was obtained at 40%wt of PBSA with 0.1 phr of DTBP. Adding 0.08 and 0.1 phr of DTBP led to the co continuous phase morphology of PLA/PBSA blends. The per cent crystallinity of PLA increased when blended with PBSA. PBSA might induce the crystallization of PLA.

  17. Chiral transformation in protonated and deprotonated adipic acids through multistep internal proton transfer.

    PubMed

    Min, Seung Kyu; Park, Mina; Singh, N Jiten; Lee, Han Myoung; Lee, Eun Cheol; Kim, Kwang S; Lagutschenkov, Anita; Niedner-Schatteburg, Gereon

    2010-09-10

    Protonated and deprotonated adipic acids (PAA: HOOC-(CH(2))(4)--COOH(2) (+) and DAA: HOOC-(CH(2))(4)-COO(-)) have a charged hydrogen bond under the influence of steric constraint due to the molecular skeleton of a circular ring. Despite the similarity between PAA and DAA, it is surprising that the lowest energy structure of PAA is predicted to have (H(2)O...H...OH(2))(+) Zundel-like symmetric hydrogen bonding, whereas that of DAA has H(3)O(+) Eigen-like asymmetric hydrogen bonding. The energy profiles show that direct proton transfer between mirror image structures is unfavorable. Instead, the chiral transformation is possible by subsequent backbone twistings through stepwise proton transfer along multistep intermediate structures, which are Zundel-like ions for PAA and Eigen-like ions for DAA. This type of chiral transformation by multistep intramolecular proton transfers is unprecedented. Several prominent OH...O short hydrogen-bond stretching peaks are predicted in the range of 1000-1700 cm(-1) in the Car-Parrinello molecular dynamics (CPMD) simulations, which show distinctive signatures different from ordinary hydrogen-bond peaks. The O-H-O stretching peaks in the range of 1800-2700 cm(-1) become insignificant above around 150 K and are almost washed out at about 300 K.

  18. Superconducting properties of adipic-acid-doped bulk MgB2 superconductor

    NASA Astrophysics Data System (ADS)

    Vajpayee, Arpita; Awana, V. P. S.; Bhalla, G. L.; Bhobe, P. A.; Nigam, A. K.; Kishan, H.

    2009-01-01

    We report the effect of adipic acid (C6H10O4) doping on lattice parameters, microstructure, critical temperature (Tc), current density (Jc) and irreversibility field (Hirr) for an MgB2 superconductor. Actual carbon (C) substitution level for boron (B) is estimated to be from 0.40 at.% to 2.95 at.% for different doping levels. A reduction in Tc from 38.43 to 34.93 K and in lattice parameter a from 3.084(3) Å to 3.075(6) Å is observed for the 10 wt% C6H10O4 doped sample in comparison to pristine MgB2. This is an indication of C substitution at boron sites, with the C coming from the decomposition of C6H10O4 at the time of reaction. Interestingly the doped samples have resulted in significant enhancement of Jc and Hirr. All the doped samples exhibit the Jc value of the order of 104 A cm-2 at 5 K and 8 T, which is higher by an order of magnitude as compared to the undoped sample. This result indicates that C6H10O4 is a promising material for MgB2 for obtaining the excellent Jc values under higher magnetic fields.

  19. Control of the phytopathogen Botrytis cinerea using adipic acid monoethyl ester.

    PubMed

    Vicedo, Begonya; de la O Leyva, María; Flors, Víctor; Finiti, Ivan; Del Amo, Gemma; Walters, Dale; Real, Maria Dolores; García-Agustín, Pilar; González-Bosch, Carmen

    2006-01-01

    The in vitro and in vivo antifungal activity of adipic acid monoethyl ester (AAME) on the necrotrophic pathogen Botrytis cinerea has been studied. This chemical effectively controlled this important phytopathogen, inhibited spore germination and mycelium development at non-phytotoxic concentrations. The effectiveness of AAME treatment is concentration-dependent and influenced by pH. Spore germination in the presence of AAME is stopped at a very early stage, preventing germ tube development. In addition, cytological changes such as retraction of the conidial cytoplasm in the fungus are observed. AAME was also found to act on membrane integrity, affecting permeability without exhibiting lytic activity, as described previously for other antifungal compounds. Polyamine content in the mycelium of B. cinerea was also affected in response to AAME treatment, resulting in putrescine reduction and spermine accumulation similar to a number of antifungal agents. Microscopic observation of treated conidia after inoculation on tomato leaves suggested that inhibited spores are not able to attach to and penetrate the leaf. Finally, AAME completely suppressed the grey mould disease of tomato fruits under controlled inoculation conditions, providing evidence for its efficacy in a biological context and for the potential use of this chemical as an alternative fungicide treatment.

  20. Properties of collagen gels cross-linked by N-hydroxysuccinimide activated adipic acid deriviate.

    PubMed

    Duan, Lian; Liu, Wentao; Tian, Zhenhua; Li, Conghu; Li, Guoying

    2014-08-01

    In order to improve the properties of collagen gel, N-hydroxysuccinimide activated adipic acid derivative (NHS-AA) was introduced into the formation of collagen fibrils. NHS-AA with different [NHS-AA]/[NH2] ratios (0.1-1.5, calculated by [ester group] of NHS-AA and [NH2] of lysine and hydroxylysine residues of collagen) was added after, simultaneously with or before the formation of collagen fibrils (abbreviated CAF, CSF and CBF, respectively) to obtain different collagen gels. With the same dose of NHS-AA, the cross-linking degree for CAF was lower than those for CSF and CBF. The formation of collagen fibrils was restrained by NHS-AA for CSF and CBF while that for CAF was unaffected. When the dose of NHS-AA increased from 0.1 to 1.5, the water contents of CSF and CBF increased while that of CAF had no obvious change. With lower dose of NHS-AA (0.1), CAF possessed higher value of G' (87.3Pa) and the best thermal stability (47.6°C). As the ratio of [NHS-AA]/[NH2] increased to 1.5, CSF had the maximum value of G' (288.8Pa) and CAF had the best thermal stability (52.9°C). These results showed collagen gels with different properties could be prepared by adding NHS-AA with different adding sequence and dose.

  1. Construction of two Cd(II) complexes by flexible adipic acid plus 2-((benzoimidazol-yl)methyl)-1H-tetrazole ligand

    NASA Astrophysics Data System (ADS)

    Duan, Wanlu; Zhang, Yuhong; Wang, Xiuxiu; Meng, Xiangru

    2015-10-01

    Two new complexes with the formulas [Cd(bimt)(adi)]n (1) and {[Cd(bimt)(adi)0.5Br]·H2O}n (2) were synthesized through reactions of 2-((benzoimidazol-yl)methyl)-1H-tetrazole (bimt) with Cd(II) salts in the presence of adipic acid (H2adi). Single crystal X-ray analysis reveals that complex 1 shows a 1D chain structure in which adipate ligand coordinates to Cd(II) ions with μ3-bridging mode. Complex 2 displays a 2D layer structure with 4-connected (44·62) topology in which adipate ligand coordinates to Cd(II) ions with μ2-bridging mode. These results reveal that the versatile coordination modes of adipate ligands play an important role in controlling the structures of the complexes. In addition, their IR spectra, element analyses, PXRD patterns and luminescent properties are investigated.

  2. Metabolism of phytanic acid and 3-methyl-adipic acid excretion in patients with adult Refsum disease.

    PubMed

    Wierzbicki, Anthony S; Mayne, Phillip D; Lloyd, Matthew D; Burston, David; Mei, Guam; Sidey, Margaret C; Feher, Michael D; Gibberd, F Brian

    2003-08-01

    Adult Refsum disease (ARD) is associated with defective alpha-oxidation of phytanic acid (PA). omega-Oxidation of PA to 3-methyl-adipic acid (3-MAA) occurs although its clinical significance is unclear. In a 40 day study of a new ARD patient, where the plasma half-life of PA was 22.4 days, omega-oxidation accounted for 30% initially and later all PA excretion. Plasma and adipose tissue PA and 3-MAA excretion were measured in a cross-sectional study of 11 patients. The capacity of the omega-oxidation pathway was 6.9 (2.8-19.4) mg [20.4 (8.3-57.4) micromol] PA/day. 3-MAA excretion correlated with plasma PA levels (r = 0.61; P = 0.03) but not adipose tissue PA content. omega-Oxidation during a 56 h fast was studied in five patients. 3-MAA excretion increased by 208 +/- 58% in parallel with the 158 (125-603)% rise in plasma PA. Plasma PA doubled every 29 h, while 3-MAA excretion followed second-order kinetics. Acute sequelae of ARD were noted in three patients (60%) after fasting. The omega-oxidation pathway can metabolise PA ingested by patients with ARD, but this activity is dependent on plasma PA concentration. omega-Oxidation forms a functional reserve capacity that enables patients with ARD undergoing acute stress to cope with limited increases in plasma PA levels.

  3. The first contribution of capillary electrophoresis to the study of abiotic origins of homochirality: investigation of the enantioselective adsorption of 3-carboxy adipic acid on minerals.

    PubMed

    Castro-Puyana, María; Salgado, Antonio; Hazen, Robert M; Crego, Antonio L; Alegre, María Luisa Marina

    2008-04-01

    CE with UV detection was used for the first time to determine the enantioselective adsorption of the short-chain tricarboxylic acid, 3-carboxy adipic acid, on minerals as a mean of investigating plausible mechanisms for the origin of biochemical homochirality on Earth. The use of vancomycine as chiral selector in the separation buffer using the partial filling technique enabled the separation of the two enantiomers of this organic acid in about 12 min. Taking into account that this compound has a low absorption of the UV light, and in order to achieve the sensitivity needed to determine the enantiomeric excess of samples of 3-carboxy adipic acid adsorbed on minerals, we applied a strategy consisting of a field-amplified sample stacking together with the use of a bubble capillary and detection at low wavelength (192 nm). This combination enabled an LOD of about 10(-7) M and the determination of the enantiomeric excess of 3-carboxy adipic acid adsorbed on calcite and feldspar mineral samples at subnanomol levels of this acid. Results showed that an enantioselective adsorption of the enantiomers of 3-carboxy adipic acid on minerals took place.

  4. X-ray studies on crystalline complexes involving amino acids and peptides. XLII. Adipic acid complexes of L- and DL-arginine and supramolecular association in arginine-dicarboxylic acid complexes.

    PubMed

    Roy, Siddhartha; Singh, Desh Deepak; Vijayan, M

    2005-02-01

    The adipic acid complexes of DL-arginine and L-arginine are made up of zwitterionic, singularly positively charged arginium ions and doubly negatively charged adipate ions, with a 2:1 stoichiometry. One of the two crystallographically independent arginium ions in the L-arginine complex has a conformation hitherto unobserved in crystal structures containing the amino acid. In the present study the structural data on arginine complexes of saturated dicarboxylic acids with 0-5 C atoms separating the two carboxyl functions are given. In terms of molecular aggregation, formic and acetic acid complexes behave in a similar way to those involving fairly long carboxylic acids such as adipic acid. By and large, the supramolecular assembly in complexes involving dicarboxylic acids with 3 or more C atoms separating the carboxyl groups (glutaric, adipic and pimelic acids), and those involving formic and acetic acids, have common features. The aggregation patterns in complexes involving oxalic, malonic and maleic acids do not share striking features among themselves (except for the mode of hydrogen-bonded dimerization of arginium ions) or with those involving larger dicarboxylic acids. Complexes of succinic acid, the shortest linear dicarboxylic acid, share features with those involving shorter as well as longer dicarboxylic acids. The difference in the behaviour of long and short dicarboxylic acids and the ambiguous behaviour of succinic acid can be broadly related to their lengths.

  5. High-index proton-exchanged MgO:LiNbO3 optical waveguides using adipic acid

    NASA Astrophysics Data System (ADS)

    Pun, E. Y. B.; Loi, K. K.; Mak, C. F.; Chung, P. S.

    1993-03-01

    We report the fabrication and characterization of proton-exchanged optical waveguides in z-cut MgO:LiNbO3 using adipic acid as a new proton source. These waveguides exhibit propagation losses of less than 1 dB/cm, a linear-step index profile, and a surface index increase of 0.149 measured at 0.633 μm wavelength. This is the largest surface index change reported for proton-exchanged MgO:LiNbO3 waveguides. The diffusion parameters were characterized optically, and the diffusion constant D0 and the activation energy Q were found to be 5.40×1010 μm2/h and 103.27 kJ/mol, respectively. The diffusion rate is slower than that of the popular phosphoric acid.

  6. Effect of dietary adipic acid and corn dried distillers grains with solubles on laying hen performance and nitrogen loss from stored excreta with or without sodium bisulfate.

    PubMed

    Romero, C; Abdallh, M E; Powers, W; Angel, R; Applegate, T J

    2012-05-01

    Effects of dietary adipic acid (0 vs. 1%) and corn dried distillers grains with solubles (DDGS; 0 vs. 20%) were evaluated on hen performance and egg characteristics from 26 to 34 wk of age. Four isocaloric and isonitrogenous diets were randomly assigned to blocks of 6 consecutive cages (36 cages per diet; 2 hens per cage). On wk 2 and 7 of the experiment, excreta were collected by cage block, mixed, and equally split into 2 containers. Sodium bisulfate (SBS) was spread (8.8 kg/100 m(2)) on the top surface of half of the containers. All containers were stored uncovered for 14 d at room temperature. Excreta pH, DM, and N content were measured on d 0, 7, and 14 of storage. Feed intake (112 g/d per hen), egg production (96.1%), and egg specific gravity (1.079 g/g) were not affected by diet. On excreta collection day, a synergy (P = 0.014) between dietary adipic acid and DDGS was detected, as the lowest excreta pH was obtained with the diet including both adipic acid and DDGS. On d 7 of storage, excreta pH was still reduced by dietary adipic acid (P = 0.046) and DDGS (P < 0.001), but a week later, only dietary DDGS decreased excreta pH (8.91 vs. 9.21; P < 0.001). Whereas dietary adipic acid had no influence on excreta N loss, excreta from hens fed 20% DDGS lost 19.7% more N (P = 0.039) during storage than hens not eating DDGS. Surface amendment of excreta with SBS increased excreta DM content, with the effect being even more marked on d 14 of storage (increase of 6.7 percentage units; P < 0.001), consistently decreased excreta pH during storage (P < 0.001) and reduced N loss by 26.1% for the 14 d of storage period.

  7. Adipic acid-2,6-bis-(1H-benzimidazol-2-yl)pyridine-water (1/2/4).

    PubMed

    Lin, Songzhu; Jia, Ruokun; Gao, Feng; Zhou, Xiaoqing

    2012-12-01

    The asymmetric unit of the title hydrated co-crystal, 2C19H13N5·C6H10O4·4H2O, consists of one 2,6-bis-(1H-benzimidazol-2-yl)pyridine mol-ecule, half of an adipic acid mol-ecule (bis-ected by an inversion center) and two water solvates. In the crystal, N-H⋯O, O-H⋯O and O-H⋯N hydrogen bonds and π-π inter-actions [centroid-centroid distances = 3.769 (2) and 3.731 (2) Å] form a three-dimensional supra-molecular structure.

  8. Dissociative Ionization Mechanism and Appearance Energies in Adipic Acid Revealed by Imaging Photoelectron Photoion Coincidence, Selective Deuteration, and Calculations.

    PubMed

    Heringa, Maarten F; Slowik, Jay G; Prévôt, André S H; Baltensperger, Urs; Hemberger, Patrick; Bodi, Andras

    2016-05-26

    Adipic acid, a model compound for oxygenated organic aerosol, has been studied at the VUV beamline of the Swiss Light Source. Internal energy selected cations were prepared by threshold photoionization using vacuum ultraviolet synchrotron radiation and imaging photoelectron photoion coincidence spectroscopy (iPEPICO). The threshold photoelectron spectrum yields a vertical ionization energy (IE) of 10.5 eV, significantly above the calculated adiabatic IE of 8.6 eV. The cationic minimum is accessible after vertical ionization by H-transfer from one of the γ-carbons to a carbonyl oxygen and is sufficiently energetic to decay by water loss at the ionization onset. The slope of the breakdown curves, quantum chemical calculations, and selective deuteration of the carboxylic hydrogens establish the dissociative photoionization mechanism. After ionization, one γ-methylene hydrogen and the two carboxylic hydrogens are randomized prior to H2O loss. On the basis of the deuteration degree in the H2O + CO-loss product at higher energies, a direct water-loss channel without complete randomization also exists. The breakdown diagram and center of gravity of the H2O + CO-loss peak were modeled to obtain 0 K appearance energies of 10.77, 10.32, and 11.53 eV for H2O + CO loss, CH2COOH loss, and H2O + CH2COOH loss from adipic acid. These agree well with the CBS-QB3 calculated values of 10.68, 10.45, and 11.57 eV, respectively, which shows that threshold photoionization can yield energetics data as long as the dissociation is statistical, even when the parent ion cannot be observed. The results can be used as a starting point for a deeper understanding of the ionization and low-energy fragmentation of organic aerosol components.

  9. Hybrid porous tin(IV) phosphonate: an efficient catalyst for adipic acid synthesis and a very good adsorbent for CO2 uptake.

    PubMed

    Dutta, Arghya; Pramanik, Malay; Patra, Astam K; Nandi, Mahasweta; Uyama, Hiroshi; Bhaumik, Asim

    2012-07-07

    A new porous organic-inorganic hybrid tin phosphonate material has been synthesized hydrothermally, which shows a Brunauer-Emmett-Teller surface area of 723 m(2) g(-1) and it adsorbs 4.8 mmol g(-1) CO(2) at 273 K and 5 bar pressure. The material also shows remarkable catalytic activity in one-pot liquid phase oxidation of cyclohexanone to adipic acid under eco-friendly conditions.

  10. Structure and properties of Al-MIL-53-ADP, a breathing MOF based on the aliphatic linker molecule adipic acid.

    PubMed

    Reinsch, Helge; Pillai, Renjith S; Siegel, Renée; Senker, Jürgen; Lieb, Alexandra; Maurin, Guillaume; Stock, Norbert

    2016-03-14

    The new aluminium based metal-organic framework [Al(OH)(O2C-C4H8-CO2)]·H2O denoted as Al-MIL-53-ADP-lp (lp stands for large pore) was synthesised under solvothermal conditions. This solid is an analogue of the archetypical aluminium terephthalate Al-MIL-53 based on the aliphatic single-chain linker molecule adipic acid (H2ADP, hexanedioic acid). In contrast to its aromatic counterparts, Al-MIL-53-ADP exhibits a structural breathing behaviour solely upon dehydration/rehydration. The crystal structure of the anhydrous compound denoted as Al-MIL-53-ADP-np (np stands for narrow pore) was determined by a combination of forcefield-based computations and Rietveld refinement of the powder X-ray diffraction data while the structure of the hydrated form Al-MIL-53-ADP-lp was derived computationally by a combination of force field based methods and Density Functional Theory calculations. Both structures were further supported by (1)H, (13)C and (27)Al high-resolution NMR MAS 1D data coupled again with simulations. Al-MIL-53-ADP was further characterised by means of vibrational spectroscopy, elemental analysis, thermogravimetry and water vapour sorption.

  11. The adipic acid enhanced flue gas desulfurization process for industrial boilers. Volume 1. Field test results. Final report Feb 81-Feb 82

    SciTech Connect

    Clarke, P.A.; Gerstle, R.W.; Henzel, D.S.; Mason, K.W.; Sabatini, S.R.

    1982-11-01

    The report gives results of an evaluation of the effect of adding adipic acid on the SO/sub 2/ removal of a wet limestone flue gas desulfurization (FGD) system on a coal-fired industrial boiler at Rickenbacker Air National Guard Base near Columbus, OH. Emission data were collected in accordance with the regulations for SO/sub 2/ compliance data specified in the Federal Register. The test results show that adding adipic acid to the limestone slurry significantly improved the SO/sub 2/ removal efficiency of the FGD system. Limited baseline data on operations with limestone only indicated a performance level of 55% SO/sub 2/ removal. With the addition of about 2200 ppm of adipic acid to the limestone scrubbing system, the unit's level of performance increased to an average of 94.3% SO/sub 2/ removal (within a standard deviation of 2.2%) during which boiler load was 70-130 million Btu/hr and gas throughput varied 300%.

  12. Growth and characterization of a single crystal of Urea Adipic acid (UAA)--a third order nonlinear optical material.

    PubMed

    Shanthi, A; Krishnan, C; Selvarajan, P

    2014-03-25

    An organic single crystal of Urea Adipic acid (UAA) was successfully grown in methanol solvent by slow solvent evaporation technique at room temperature (30 °C). The structure of grown crystal was elucidated from the X-ray diffraction study and it belongs to monoclinic system with centrosymmetric space group P21/c. The optical transmission spectrum of UAA has been recorded and its theoretical calculations were carried out to determine the linear optical constants such as linear absorption coefficient, extinction coefficient, refractive index and reflectance etc. The third-order nonlinearities of UAA crystal have been investigated by Z-scan method. The values of nonlinear refractive index (n2), the absorption coefficient (β) and third-order nonlinear susceptibility (χ((3))) are found to be the order of 0.96×10(-10) cm(2)/W, 1.248×10(-4) cm/W and 6.44×10(-8) esu respectively. Fourier Transform Infra Red and Raman spectroscopy studies reveal the intermolecular interactions present in the UAA sample. The dielectric and mechanical measurements of the title compound are also reported.

  13. Growth and characterization of a single crystal of Urea Adipic acid (UAA) - A third order nonlinear optical material

    NASA Astrophysics Data System (ADS)

    Shanthi, A.; Krishnan, C.; Selvarajan, P.

    2014-03-01

    An organic single crystal of Urea Adipic acid (UAA) was successfully grown in methanol solvent by slow solvent evaporation technique at room temperature (30 °C). The structure of grown crystal was elucidated from the X-ray diffraction study and it belongs to monoclinic system with centrosymmetric space group P21/c. The optical transmission spectrum of UAA has been recorded and its theoretical calculations were carried out to determine the linear optical constants such as linear absorption coefficient, extinction coefficient, refractive index and reflectance etc. The third-order nonlinearities of UAA crystal have been investigated by Z-scan method. The values of nonlinear refractive index (n2), the absorption coefficient (β) and third-order nonlinear susceptibility (χ(3)) are found to be the order of 0.96 × 10-10 cm2/W, 1.248 × 10-4 cm/W and 6.44 × 10-8 esu respectively. Fourier Transform Infra Red and Raman spectroscopy studies reveal the intermolecular interactions present in the UAA sample. The dielectric and mechanical measurements of the title compound are also reported.

  14. Synthesis of orthogonally protected (2S)-2-amino-adipic acid (α-AAA) and (2S,4R)-2-amino-4-hydroxyadipic acid (Ahad).

    PubMed

    Yadav, Saroj; Taylor, Carol M

    2013-06-07

    (2S,4R)-2-amino-4-hydroxyadipic acid (Ahad) building block 45 was synthesized in 11 steps and 6.5% overall yield from commercially available materials. Key steps in stereocontrol were an asymmetric conjugate addition employing a proline-based catalyst and a syn-selective intramolecular-conjugate addition of an oxygen nucleophile to an α,β-unsaturated ester. To enable incorporation of α-amino-adipic acid (α-AAA) and Ahad into peptides, a truly orthogonal protecting group scheme was developed, encompassing an allyloxycarbonyl (Alloc) carbamate for Nα, a tert-butyl ester for the δ-COOH, an acetol ester for the α-COOH, and a tert-butyldimethylsilyl ether for the γ-hydroxy group of Ahad.

  15. Solid-state characterization of novel active pharmaceutical ingredients: cocrystal of a salbutamol hemiadipate salt with adipic acid (2:1:1) and salbutamol hemisuccinate salt.

    PubMed

    Paluch, Krzysztof J; Tajber, Lidia; Elcoate, Curtis J; Corrigan, Owen I; Lawrence, Simon E; Healy, Anne Marie

    2011-08-01

    The production of salt or cocrystalline forms is a common approach to alter the physicochemical properties of pharmaceutical compounds. The goal of this work was to evaluate the impact of anion choice (succinate, adipate, and sulfate) on the physicochemical characteristics of salbutamol forms. Novel crystals of salbutamol were produced by solvent evaporation: a cocrystal of salbutamol hemiadipate with adipic acid (salbutamol adipate, SA), salbutamol hemisuccinate tetramethanolate (SSU.MeOH), and its desolvated form (SSU). The crystalline materials obtained were characterized using thermal, X-ray, nuclear magnetic resonance, Fourier transform infrared spectroscopy, dynamic vapor sorption (DVS), and elemental analysis. The crystal forms of SA and SSU.MeOH were determined to be triclinic, (Pī), and monoclinic, (P2(1) /n), respectively. DVS analysis confirmed that SSU and SA do not undergo hydration under increased relative humidity. Both thermal and elemental analyses confirmed the stoichiometry of the salt forms. The aqueous solubilities of SA and SSU were measured to be 82 ± 2 mg/mL (pH 4.5 ± 0.1) and 334 ± 13 mg/mL (pH 6.6 ± 0.1), respectively. Measured values corresponded well with the calculated pH solubility profiles. The intrinsic dissolution rate of cocrystallized SA was approximately four times lower than that of SSU, suggesting its use as an alternative to more rapidly dissolving salbutamol sulfate.

  16. Determination of polyadipates migrating from lid gaskets of glass jars. Hydrolysis to adipic acid and measurement by LC-MS/MS.

    PubMed

    Driffield, M; Bradley, E L; Harmer, N; Castle, L; Klump, S; Mottier, P

    2010-10-01

    Polyadipate plasticizers can be present in the polyvinylchloride (PVC) gaskets used to seal the lids of glass jars. As the gaskets can come into direct contact with the foodstuffs inside the jar, the potential exists for polyadipate migration into the food. The procedure and performance characteristics of a test method for the analysis of polyadipates in food simulants (3% aqueous acetic acid and 10% aqueous ethanol) and the volatile test media used in substitute fat tests (isooctane and 95% aqueous ethanol) are described. The PVC gaskets were exposed to the food simulants or their substitutes under standard test conditions. Studies were initially carried out using direct measurement of the polyadipate oligomers by liquid chromatography with time-of-flight mass spectrometric detection (LC-TOF-MS) but this was not practical due to the number of peaks detected. Instead, the migrating polyadipates were hydrolysed to adipic acid and measured by liquid chromatography with tandem mass spectrometric detection (LC-MS/MS). The amount of polyadipate that this measurement of adipic acid represents was then calculated. Method performance was assessed by analysis of gaskets from two types of jar lids by single-laboratory validation. Linearity, sensitivity, repeatability, intermediate reproducibility and recovery were determined to be suitable for checking compliance with the 30 mg/kg specific migration limits for polyesters of 1,2-propane diol and/or 1,3- and/or 1,4-butanediol and/or polypropylene-glycol with adipic acid, which may be end-capped with acetic acid or fatty acids C(12)-C(18) or n-octanol and/or n-decanol. The method was found to be much quicker than previous methods involving extraction, clean-up, hydrolysis, esterification, derivatisation and GC measurement, consequently saving time and money.

  17. Health Hazard Evaluation Report HETA 83-166-1594, Witco Chemical Corporation, Perth Amboy, New Jersey. [Ethylene oxide, glycols, and adipic acid

    SciTech Connect

    Cummings, C.E.; Roseman, J.

    1985-05-01

    Area and personel air samples were analyzed for ethylene oxide, glycols, and adipic-acid at the Witco Chemical Corporation, Perth Amboy, New Jersey from November to December, 1983 and May, 1984. The evaluation was requested by the union to investigate possible health effects due to polychlorinated biphenyls (PCBs), glycols, and ethylene oxide. The evaluation was assigned to the New Jersey State Department of Health. The authors conclude that health hazards due to ethylene oxide and airborne fatty acid exposures exist. Recommendations include improving ventilation and work practices and implementing an OSHA approved respirator program.

  18. Mesoporous core–shell Fenton nanocatalyst: a mild, operationally simple approach to the synthesis of adipic acid.

    PubMed

    Patra, Astam K; Dutta, Arghya; Bhaumik, Asim

    2013-09-09

    Mesoporous nanoparticles composed of γ-Al2O3 cores and α-Fe2O3 shells were synthesized in aqueous medium. The surface charge of γ-Al2O3 helps to form the core–shell nanocrystals. The core–shell structure and formation mechanism have been investigated by wide-angle XRD, energy-dispersive X-ray spectroscopy, and elemental mapping by ultrahigh-resolution (UHR) TEM and X-ray photoelectron spectroscopy. The N2 adsorption–desorption isotherm of this core–shell materials, which is of type IV, is characteristic of a mesoporous material having a BET surface area of 385 m2 g(−1) and an average pore size of about 3.2 nm. The SEM images revealed that the mesoporosity in this core–shell material is due to self-aggregation of tiny spherical nanocrystals with sizes of about 15–20 nm. Diffuse-reflectance UV/Vis spectra, elemental mapping by UHRTEM, and wide-angle XRD patterns indicate that the materials are composed of aluminum oxide cores and iron oxide shells. These Al2O3@Fe2O3 core–shell nanoparticles act as a heterogeneous Fenton nanocatalyst in the presence of hydrogen peroxide, and show high catalytic efficiency for the one-pot conversion of cyclohexanone to adipic acid in water. The heterogeneous nature of the catalyst was confirmed by a hot filtration test and analysis of the reaction mixture by atomic absorption spectroscopy. The kinetics of the reaction was monitored by gas chromatography and 1H NMR spectroscopy. The new core–shell catalyst remained in a separate solid phase, which could easily be removed from the reaction mixture by simple filtration and the catalyst reused efficiently.

  19. Experimental and theoretical charge density distribution in a host-guest system: synthetic terephthaloyl receptor complexed to adipic acid.

    PubMed

    Nguyen, Thanh Ha; Howard, Sian T; Hanrahan, Jane R; Groundwater, Paul W; Platts, James A; Hibbs, David E

    2012-06-14

    The experimental charge density distributions in a host-guest complex have been determined. The host, 1,4-bis[[(6-methylpyrid-2-yl)amino]carbonyl]benzene (1) and guest, adipic acid (2). The molecular geometries of 1 and 2 are controlled by the presence in the complex of intermolecular hydrogen bonding interactions and the presence in the host 1 of intramolecular hydrogen bonding motifs. This system therefore serves as an excellent model for studying noncovalent interactions and their effects on structure and electron density, and the transferability of electron distribution properties between closely related molecules. For the complex, high resolution X-ray diffraction data created the basis for a charge density refinement using a pseudoatomic multipolar expansion (Hansen-Coppens formalism) against extensive low-temperature (T = 100 K) single-crystal X-ray diffraction data and compared with a selection of theoretical DFT calculations on the same complex. The molecules crystallize in the noncentrosymmetric space group P2(1)2(1)2(1) with two independent molecules in the asymmetric unit. A topological analysis of the resulting density distribution using the atoms in molecules methodology is presented along with multipole populations, showing that the host and guest structures are relatively unaltered by the geometry changes on complexation. Three separate refinement protocols were adopted to determine the effects of the inclusion of calculated hydrogen atom anisotropic displacement parameters on hydrogen bond strengths. For the isotropic model, the total hydrogen bond energy differs from the DFT calculated value by ca. 70 kJ mol(-1), whereas the inclusion of higher multipole expansion levels on anisotropic hydrogen atoms this difference is reduced to ca. 20 kJ mol(-l), highlighting the usefulness of this protocol when describing H-bond energetics.

  20. Adipic acid-2,4-diamino-6-(4-meth-oxy-phen-yl)-1,3,5-triazine (1/2).

    PubMed

    Thanigaimani, Kaliyaperumal; Razak, Ibrahim Abdul; Arshad, Suhana; Jagatheesan, Rathinavel; Santhanaraj, Kulandaisamy Joseph

    2012-10-01

    The asymmetric unit of the title compound, 2C(10)H(11)N(5)O·C(6)H(10)O(4), consists of a 2,4-diamino-6-(4-meth-oxy-phen-yl)-1,3,5-triazine mol-ecule and one-half mol-ecule of adipic acid which lies about an inversion center. The triazine ring makes a dihedral angle of 12.89 (4)° with the adjacent benzene ring. In the crystal, the components are linked by N-H⋯O and O-H⋯N hydrogen bonds, thus generating a centrosymmetric 2 + 1 unit of triazine and adipic acid mol-ecules with R(2) (2)(8) motifs. The triazine mol-ecules are connected to each other by N-H⋯N hydrogen bonds, forming an R(2) (2)(8) motif and a supra-molecular ribbon along the c axis. The 2 + 1 units and the supra-molecular ribbons are further inter-linked by weak N-H⋯O, C-H⋯O and C-H⋯π inter-actions, resulting in a three-dimensional network.

  1. Polymer blends of polylactic acid (PLA) and polybutylene succinate-adipate

    NASA Astrophysics Data System (ADS)

    Ma, Wenguang

    A series of blends consisting of polylactic acid (PLA) and aliphatic succinate polyester (BionolleRTM #3000) had been prepared and investigated. The results of mechanical property investigations showed that using 20 wt% Bionolle#3000 can significantly increase the toughness of PLA. BionolleRTM #3000 also reduces the physical aging rate of PLA so blends remain tough longer. Conversely, the stiffness of BionolleRTM #3000 can be significantly increased by blending in PLA. DMA and DSC results show that PLA/BionolleRTM 3000 blends are not thermodynamically miscible, but are compatible blends. Studies have also been performed to determine the amount and rate of aerobic biodegradation of PLA/aliphatic succinate polyester blends in biologically active composting, enzymatic, and soil environments. The changes in molecular weight, molecular structure and thermal properties in the composting environment were also studied by GPC, NMR and DSC analyses. The research results showed BionolleRTM #3000 had a high degradation rate, while PLA had a low degradation rate. PLA/BionolleRTM #3000 blends had moderate degradation rates that increased with BionolleRTM #3000 content. The melt flow behavior of PLA/BionolleRTM #3000 blends has been studied by capillary rheometry. The relationship of the blends' viscosity with their composition, shear stress, shear rate, and temperature has been investigated. Power law index and activation energy of PLA, BionolleRTM #3000 and their blends have been calculated. The experimental and theoretical data can let us understand the processability of PLA/BionolleRTM #3000 blends. A scanning electron microscope (SEM) was used to investigate the morphological structure of the PLA/BionolleRTM #3000 blends. Micrographs of the samples made from different methods (blown film, extrudate and compression molding sheet) were taken; their differences in morphology were compared. For comparison, the micrographs of blend PLA/BionolleRTM #6000 was also studied. The

  2. Substrate specificity of 2-hydroxyglutaryl-CoA dehydratase from Clostridium symbiosum: toward a bio-based production of adipic acid.

    PubMed

    Parthasarathy, Anutthaman; Pierik, Antonio J; Kahnt, Jörg; Zelder, Oskar; Buckel, Wolfgang

    2011-05-03

    Expression of six genes from two glutamate fermenting clostridia converted Escherichia coli into a producer of glutaconate from 2-oxoglutarate of the general metabolism (Djurdjevic, I. et al. 2010, Appl. Environ. Microbiol.77, 320-322). The present work examines whether this pathway can also be used to reduce 2-oxoadipate to (R)-2-hydroxyadipic acid and dehydrate its CoA thioester to 2-hexenedioic acid, an unsaturated precursor of the biotechnologically valuable adipic acid (hexanedioic acid). 2-Hydroxyglutaryl-CoA dehydratase from Clostridium symbiosum, the key enzyme of this pathway and a potential radical enzyme, catalyzes the reversible dehydration of (R)-2-hydroxyglutaryl-CoA to (E)-glutaconyl-CoA. Using a spectrophotometric assay and mass spectrometry, it was found that (R)-2-hydroxyadipoyl-CoA, oxalocrotonyl-CoA, muconyl-CoA, and butynedioyl-CoA, but not 3-methylglutaconyl-CoA, served as alternative substrates. Hydration of butynedioyl-CoA most likely led to 2-oxosuccinyl-CoA, which spontaneously hydrolyzed to oxaloacetate and CoASH. The dehydratase is not specific for the CoA-moiety because (R)-2-hydroxyglutaryl-thioesters of N-acetylcysteamine and pantetheine served as almost equal substrates. Whereas the related 2-hydroxyisocaproyl-CoA dehydratase generated the stable and inhibitory 2,4-pentadienoyl-CoA radical, the analogous allylic ketyl radical could not be detected with muconyl-CoA and 2-hydroxyglutaryl-CoA dehydratase. With the exception of (R)-2-hydroxyglutaryl-CoA, all mono-CoA-thioesters of dicarboxylates used in this study were synthesized with glutaconate CoA-transferase from Acidaminococcus fermentans. The now possible conversion of (R)-2-hydroxyadipate via (R)-2-hydroxyadipoyl-CoA and 2-hexenedioyl-CoA to 2-hexenedioate paves the road for a bio-based production of adipic acid.

  3. Three-dimensional hydrogen-bonded structures in the hydrated proton-transfer salts of isonipecotamide with the dicarboxylic oxalic and adipic acid homologues.

    PubMed

    Smith, Graham; Wermuth, Urs D

    2013-10-01

    The structures of the 1:1 hydrated proton-transfer compounds of isonipecotamide (piperidine-4-carboxamide) with oxalic acid, 4-carbamoylpiperidinium hydrogen oxalate dihydrate, C6H13N2O(+)·C2HO4(-)·2H2O, (I), and with adipic acid, bis(4-carbamoylpiperidinium) adipate dihydrate, 2C6H13N2O(+)·C6H8O4(2-)·2H2O, (II), are three-dimensional hydrogen-bonded constructs involving several different types of enlarged water-bridged cyclic associations. In the structure of (I), the oxalate monoanions give head-to-tail carboxylic acid O-H···O(carboxyl) hydrogen-bonding interactions, forming C(5) chain substructures which extend along a. The isonipecotamide cations also give parallel chain substructures through amide N-H···O hydrogen bonds, the chains being linked across b and down c by alternating water bridges involving both carboxyl and amide O-atom acceptors and amide and piperidinium N-H···O(carboxyl) hydrogen bonds, generating cyclic R4(3)(10) and R3(2)(11) motifs. In the structure of (II), the asymmetric unit comprises a piperidinium cation, half an adipate dianion, which lies across a crystallographic inversion centre, and a solvent water molecule. In the crystal structure, the two inversion-related cations are interlinked through the two water molecules, which act as acceptors in dual amide N-H···O(water) hydrogen bonds, to give a cyclic R4(2)(8) association which is conjoined with an R4(4)(12) motif. Further N-H···O(water), water O-H···O(amide) and piperidinium N-H···O(carboxyl) hydrogen bonds give the overall three-dimensional structure. The structures reported here further demonstrate the utility of the isonipecotamide cation as a synthon for the generation of stable hydrogen-bonded structures. The presence of solvent water molecules in these structures is largely responsible for the non-occurrence of the common hydrogen-bonded amide-amide dimer, promoting instead various expanded cyclic hydrogen-bonding motifs.

  4. Interactions of collagen molecules in the presence of N-hydroxysuccinimide activated adipic acid (NHS-AA) as a crosslinking agent.

    PubMed

    Zhang, Min; Wu, Kun; Li, Guoying

    2011-11-01

    The effect of crosslinking agent on pepsin-soluble bovine collagen solution was examined using N-hydroxysuccinimide activated adipic acid (NHS-AA) as a crosslinker. Electrophoretic patterns indicated that crosslinks formed when NHS-AA was added. A higher polarity level deduced from the changes in the fluorescence emission spectrum of pyrene in the crosslinked collagen solution indicated that the formation of well-ordered aggregates was suppressed. The random aggregation of collagens was also observed by atomic force microscopy (AFM). Furthermore, the association of collagens into fibrils was influenced by crosslinking. Self-assembly was suppressed at 37°C; however, as temperature was increased to 39°C, a small amount of NHS-AA leaded to an improvement in the ability of self-aggregation. Although more random structure was brought about by crosslinking, self-aggregation might still be promoted as temperature was increased, accompanying by the thermal stability improvement of fibrils.

  5. The Penicillium chrysogenum aclA gene encodes a broad-substrate-specificity acyl-coenzyme A ligase involved in activation of adipic acid, a side-chain precursor for cephem antibiotics.

    PubMed

    Koetsier, Martijn J; Gombert, Andreas K; Fekken, Susan; Bovenberg, Roel A L; van den Berg, Marco A; Kiel, Jan A K W; Jekel, Peter A; Janssen, Dick B; Pronk, Jack T; van der Klei, Ida J; Daran, Jean-Marc

    2010-01-01

    Activation of the cephalosporin side-chain precursor to the corresponding CoA-thioester is an essential step for its incorporation into the beta-lactam backbone. To identify an acyl-CoA ligase involved in activation of adipate, we searched in the genome database of Penicillium chrysogenum for putative structural genes encoding acyl-CoA ligases. Chemostat-based transcriptome analysis was used to identify the one presenting the highest expression level when cells were grown in the presence of adipate. Deletion of the gene renamed aclA, led to a 32% decreased specific rate of adipate consumption and a threefold reduction of adipoyl-6-aminopenicillanic acid levels, but did not affect penicillin V production. After overexpression in Escherichia coli, the purified protein was shown to have a broad substrate range including adipate. Finally, protein-fusion with cyan-fluorescent protein showed co-localization with microbody-borne acyl-transferase. Identification and functional characterization of aclA may aid in developing future metabolic engineering strategies for improving the production of different cephalosporins.

  6. Evolution of insoluble eutectic Si particles in anodic oxidation films during adipic-sulfuric acid anodizing processes of ZL114A aluminum alloys

    NASA Astrophysics Data System (ADS)

    Hua, Lei; Liu, Jian-hua; Li, Song-mei; Yu, Mei; Wang, Lei; Cui, Yong-xin

    2015-03-01

    The effects of insoluble eutectic Si particles on the growth of anodic oxide films on ZL114A aluminum alloy substrates were investigated by optical microscopy (OM) and scanning electron microscopy (SEM). The anodic oxidation was performed at 25°C and a constant voltage of 15 V in a solution containing 50 g/L sulfuric acid and 10 g/L adipic acid. The thickness of the formed anodic oxidation film was approximately 7.13 μm. The interpore distance and the diameters of the major pores in the porous layer of the film were within the approximate ranges of 10-20 nm and 5-10 nm, respectively. Insoluble eutectic Si particles strongly influenced the morphology of the anodic oxidation films. The anodic oxidation films exhibited minimal defects and a uniform thickness on the ZL114A substrates; in contrast, when the front of the oxide oxidation films encountered eutectic Si particles, defects such as pits and non-uniform thickness were observed, and pits were observed in the films.

  7. Supra-molecular architecture in a co-crystal of the N(7)-H tautomeric form of N (6)-benzoyl-adenine with adipic acid (1/0.5).

    PubMed

    Swinton Darious, Robert; Thomas Muthiah, Packianathan; Perdih, Franc

    2016-06-01

    The asymmetric unit of the title co-crystal, C12H9N5O·0.5C6H10O4, consists of one mol-ecule of N (6)-benzoyl-adenine (BA) and one half-mol-ecule of adipic acid (AA), the other half being generated by inversion symmetry. The dihedral angle between the adenine and phenyl ring planes is 26.71 (7)°. The N (6)-benzoyl-adenine mol-ecule crystallizes in the N(7)-H tautomeric form with three non-protonated N atoms. This tautomeric form is stabilized by intra-molecular N-H⋯O hydrogen bonding between the carbonyl (C=O) group and the N(7)-H hydrogen atom on the Hoogsteen face of the purine ring, forming an S(7) ring motif. The two carboxyl groups of adipic acid inter-act with the Watson-Crick face of the BA mol-ecules through O-H⋯N and N-H⋯O hydrogen bonds, generating an R 2 (2)(8) ring motif. The latter units are linked by N-H⋯N hydrogen bonds, forming layers parallel to (10-5). A weak C-H⋯O hydrogen bond is also present, linking adipic acid mol-ecules in neighbouring layers, enclosing R (2) 2(10) ring motifs and forming a three-dimensional structure. C=O⋯π and C-H⋯π inter-actions are also present in the structure.

  8. Unusual reactivity of cytotoxic cis-dihydrazide Pt(II) complexes in aqueous solution.

    PubMed

    Kushev, Daniel; Grünert, Renate; Spassovska, Nadejda; Golovinsky, Evgeny; Bednarski, Patrick J

    2003-09-01

    Complexes of the general structure cis-[PtX(2)(hydrazide)(2)] and cis-[PtX(2)NH(3)(hydrazide)], where X=Cl(-), Br(-) and I(-), and hydrazide=cyclohexylcarboxylic acid hydrazide (chcah), cyclopentylcarboxylic acid hydrazide (cpcah), 3-aminocyclohexanspiro-5-hydantoin (achsh) and 3-aminocyclopentanspiro-5-hydantoin (acpsh), were investigated with respect to aqueous stability, DNA platination rates and cytotoxic activity on a panel of seven human cancer cell lines as well as a cisplatin-resistant cell line. Stabilities in aqueous solution, determined by RP-HPLC and UV-Vis methods, were highly dependent on the type of halide ligand, with stability decreasing in the order I(-)>Cl(-)>Br(-). Added chloride (100 mM) only stabilized the dichloro-Pt(II) complexes containing the hydrazide as part of a hydantoin ring (i.e., achsh). Platination of calf thymus DNA determined by AAS was most rapid with dichloro-Pt(II) complexes containing achsh ligand. The mixed-amine dichloro-Pt(II) complexes with either chcah or cpcah ligands also platinated DNA >80%, but at a slower rate, while dihydrazide dichloro-Pt(II) complexes with either chcah or cpcah ligands resulted in <25% DNA platination at 24 h. cis-[PtX(2)(hydrazide)(2)], where hydrazide=chcah or cpcah, were the most potent compounds (chcah>cpcah), but activity was independent of the halide ligand (I(-)=Cl(-)=Br(-)). These complexes showed no cross-resistance with cisplatin, but they also showed little differentiation in potency over the seven cell lines. Complexes with the hydantoin ligands achsh and acpsh were inactive in all cell lines. Thus, neither stability in aqueous media nor covalent binding to DNA are correlated with biological activity, suggesting that cis-dihydrazide Pt(II) complexes act by a unique mechanism of action.

  9. Self-assembled nanoparticles based on chondroitin sulfate-deoxycholic acid conjugates for docetaxel delivery: Effect of degree of substitution of deoxycholic acid.

    PubMed

    Liu, Mengrui; Du, Hongliang; Zhai, Guangxi

    2016-10-01

    Hydrophobically-modified polymers based on chondroitin sulfate with different degree of substitution (DS) of deoxycholic acid (DOCA) were developed for docetaxel delivery. Chondroitin sulfate-deoxycholic acid (CSAD) bioconjugates were synthesized via the linker of adipic dihydrazide by amide bond. They were characterized with spherical shape, mean diameter of around 165.2nm and negative zeta potential (-14.87 to -20.53mV). An increase of DOCA DS reduced size of nanoparticles, while increasing drug loading efficiency. Drug release in vitro showed a triphasic sustained pattern and higher accumulative drug release percentage was observed with increased DS of DOCA on polymer. Self-assemblies with higher DS also had enhanced internalization of nanoparticles and stronger cytotoxicity at the cellular level. The self-assemble nanoparticles demonstrate to be excellent targeting drug delivery systems and the desired therapeutics can be achieved via the alteration of DS.

  10. Improved production of adipate with Escherichia coli by reversal of β-oxidation.

    PubMed

    Kallscheuer, Nicolai; Gätgens, Jochem; Lübcke, Marvin; Pietruszka, Jörg; Bott, Michael; Polen, Tino

    2017-03-01

    The linear C6 dicarboxylic acid adipic acid is an important bulk chemical in the petrochemical industry as precursor of the polymer nylon-6,6-polyamide. In recent years, efforts were made towards the biotechnological production of adipate from renewable carbon sources using microbial cells. One strategy is to produce adipate via a reversed β-oxidation pathway. Hitherto, the adipate titers were very low due to limiting enzyme activities for this pathway. In most cases, the CoA intermediates are non-natural substrates for the tested enzymes and were therefore barely converted. We here tested heterologous enzymes in Escherichia coli to overcome these limitations and to improve the production of adipate via a reverse β-oxidation pathway. We tested in vitro selected enzymes for the efficient reduction of the enoyl-CoA and in the final reaction for the thioester cleavage. The genes encoding the enzymes which showed in vitro the highest activity were then used to construct an expression plasmid for a synthetic adipate pathway. Expression of paaJ, paaH, paaF, dcaA, and tesB in E. coli BL21(DE3) resulted in the production of up to 36 mg/L of adipate after 30 h of cultivation. Beside the activities of the pathway enzymes, the availability of metabolic precursors may limit the synthesis of adipate, providing another key target for further strain engineering towards high-yield production of adipate with E. coli.

  11. Novel electrospun nanofibrous matrices prepared from poly(lactic acid)/poly(butylene adipate) blends for controlled release formulations of an anti-rheumatoid agent.

    PubMed

    Siafaka, Panoraia I; Barmbalexis, Panagiotis; Bikiaris, Dimitrios N

    2016-06-10

    In the present work, a series of novel formulations consisting of poly(lactic acid)/poly(butylene adipate) (PLA/PBAd) electrospun blends was examined as controlled release matrices for Leflunomide's active metabolite, Teriflunomide (TFL). The mixtures were prepared using different ratios of PLA and PBAd in order to produce nanofibrous matrices with different characteristics. Miscibility studies of the blended polymeric fibers were performed through differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). Hydrolytic degradation in the prepared fibers was evaluated at 37°C using a phosphate buffered saline solution. Different concentrations of (TFL) (5, 10, 15wt.%) were incorporated into nanofibers for examining the drug release behavior in simulated body fluids (SBF), at 37°C. The drug-loaded nanofibrous formulations were further characterized by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, DSC and XRD. Gel permeation chromatography (GPC) analysis was used to evaluate the mechanism of TFL release. Artificial neural networks (ANN) and multi-linear-regression (MLR) models were used to evaluate the effect of % content of PBAd (X1) and TFL (X2) on an initial burst effect and a dissolution behavior. It was found that PLA/PBAd nanofibers have different diameters depending on the ratio of used polyesters and added drug. TFL was incorporated in an amorphous form inside the polymeric nanofibers. In vitro release studies reveal that a drug release behavior is correlated with the size of the nanofibers, drug loading and matrix degradation after a specific time. ANN dissolution modeling showed increased correlation efficacy compared to MLR.

  12. Supra­molecular architecture in a co-crystal of the N(7)—H tautomeric form of N 6-benzoyl­adenine with adipic acid (1/0.5)

    PubMed Central

    Swinton Darious, Robert; Thomas Muthiah, Packianathan; Perdih, Franc

    2016-01-01

    The asymmetric unit of the title co-crystal, C12H9N5O·0.5C6H10O4, consists of one mol­ecule of N 6-benzoyl­adenine (BA) and one half-mol­ecule of adipic acid (AA), the other half being generated by inversion symmetry. The dihedral angle between the adenine and phenyl ring planes is 26.71 (7)°. The N 6-benzoyl­adenine mol­ecule crystallizes in the N(7)—H tautomeric form with three non-protonated N atoms. This tautomeric form is stabilized by intra­molecular N—H⋯O hydrogen bonding between the carbonyl (C=O) group and the N(7)—H hydrogen atom on the Hoogsteen face of the purine ring, forming an S(7) ring motif. The two carboxyl groups of adipic acid inter­act with the Watson–Crick face of the BA mol­ecules through O—H⋯N and N—H⋯O hydrogen bonds, generating an R 2 2(8) ring motif. The latter units are linked by N—H⋯N hydrogen bonds, forming layers parallel to (10-5). A weak C—H⋯O hydrogen bond is also present, linking adipic acid mol­ecules in neighbouring layers, enclosing R 2 2(10) ring motifs and forming a three-dimensional structure. C=O⋯π and C—H⋯π inter­actions are also present in the structure. PMID:27308047

  13. Influence on the physicochemical properties of fish collagen gels using self-assembly and simultaneous cross-linking with the N-hydroxysuccinimide adipic acid derivative.

    PubMed

    Shen, Lirui; Tian, Zhenhua; Liu, Wentao; Li, Guoying

    2015-06-01

    Collagen gels from Southern catfish (Silurus meridionalis Chen) skins were prepared via the self-assembly of collagen molecules and simultaneous cross-linking with the N-hydroxysuccinimide adipic acid derivative (NHS-AA). The doses of NHS-AA were converted to [NHS-AA]/[NH2] ratios (0.025-1.6, calculated by the [active ester group] of NHS-AA and [ε-NH2] of lysine and hydroxylysine residues of collagen). When the ratio < 0.05, collagen gels were formed by collagen molecule self-assembly, resulting in the opalescent appearance of collagen gels and the characteristic D-periodicity of partial collagen fibrils, the collagen gel ([NHS-AA]/[NH2] = 0.05) displayed a small increase in denaturation temperature (Td, 42.8 °C), remaining weight (12.59%), specific water content (SWC 233.7) and elastic modulus (G' 128.4 Pa) compared with uncross-linked collagen gel (39.1 °C, 9.12%, 222.4 and 85.4 Pa, respectively). As the ratio > 0.05, disappearance of D-periodicity and a gradual change in appearance from opalescent to transparent suggested that the inhibition of NHS-AA in the self-assembly of collagen molecules was more obvious. As a result, the collagen gel ([NHS-AA]/[NH2] = 0.2) had the lowest Td (35.8 °C), remaining weight (7.96%), SWC (130.9) and G' (31.9 Pa). When the ratio was 1.6, the collagen molecule self-assembly was markedly suppressed and the formation of collagen gel was predominantly via the covalent cross-linking bonds which led to the transparent appearance, and the maximum values of Td (47.0 °C), remaining weight (45.92%) and G' (420.7 Pa) of collagen gel. These results indicated that collagen gels with different properties can be prepared using different NHS-AA doses.

  14. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... respirators meet the minimum requirement for § 721.63(a)(4): Air-purifying, tight-fitting full-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  15. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... respirators meet the minimum requirement for § 721.63(a)(4): Air-purifying, tight-fitting full-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  16. Amended final report of the safety assessment of dibutyl adipate as used in cosmetics.

    PubMed

    Andersen, Alan

    2006-01-01

    Dibutyl Adipate, the diester of butyl alcohol and adipic acid, functions as a plasticizer, skin-conditioning agent, and solvent in cosmetic formulations. It is reportedly used at a concentration of 5% in nail polish and 8% in suntan gels, creams, and liquids. Dibutyl Adipate is soluble in organic solvents, but practically insoluble in water. Dibutyl Adipate does not absorb radiation in the ultraviolet (UV) region of the spectrum. Dibutyl Adipate is not toxic in acute oral or dermal animal toxicity tests. In a subchronic dermal toxicity study, 1.0 ml/kg day-1 caused a significant reduction in body weight gain in rabbits, but 0.5 ml/kg/day1 was without effect. In a study with dogs, no adverse effects were observed when an emulsion containing 6.25% Dibutyl Adipate was applied to the entire body twice a week for 3 months. Dibutyl Adipate was tested for dermal irritation using rabbits and mice and a none to minimal irritation was observed. Dibutyl Adipate at a concentration of 25% was not a sensitizer in a guinea pig maximization study. Undiluted Dibutyl Adipate was minimally irritating to the eyes of rabbits and 0.1% was nonirritating. A significant increase in fetal gross abnormalities was observed in rats given intraperitoneal injections of Dibutyl Adipate at 1.75 ml/kg on 3 separate days during gestation, but no effect was seen in animals given 1.05 ml/kg. Dibutyl Adipate was not genotoxic in either bacterial or mammalian test systems. Clinical patch tests confirmed the absence of skin irritation found in animal tests. Clinical phototoxicity tests were negative. Dibutyl Adipate at 0.1% was not an ocular irritant in two male volunteers. In a clinical test of comedogenicity, Dibutyl Adipate produced no effect. The Cosmetic Ingredient Review (CIR) Expert Panel recognized that use of Dibutyl Adipate in suntan cosmetic products will result in repeated, frequent exposure in a leave-on product. The available data demonstrate no skin sensitization or cumulative skin

  17. Di(2-ethylhexyl)adipate

    Integrated Risk Information System (IRIS)

    Di ( 2 - ethylhexyl ) adipate ; CASRN 103 - 23 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Non

  18. Topological aspects of lanthanide-adipate-aqua compounds: Close packed and open framework structures

    NASA Astrophysics Data System (ADS)

    Chowdhuri, Durga Sankar; Kumar Jana, Swapan; Hazari, Debdoot; Zangrando, Ennio; Dalai, Sudipta

    2013-07-01

    A search in the Cambridge Structural Database (CSD) for lanthanide complexes with adipate [OOC(CH2)4COO]2- and aqua ligands retrieved a fair number of compounds. To this dataset a new lanthanum metal-organic framework, {[La2(adip)3(H2O)2] (1) (adipH2=adipic acid), synthesised and structurally characterized in these labs, was included. The crystal structures of these coordination polymers, of general formulation [Ln2(adip)3(H2O)x], exhibit a variety of topologies and dimensionality, which were clustered in different classes and described in detail. It was explored that the majority of these evidences the presence of metal chains or dinuclear Ln2 entities (separated in both cases by 4.0-4.8 Å), where lanthanide ions are differently connected by carboxylate groups with chelating or oxygen-bridging mode. The different amount of coordinated water molecules appear to affect the solid state networks. Moreover the crystal packing of these compounds shows peculiar aspects and examples were reported in the literature where the long alkyl chain of adipate connectors give rise to interpenetrated structures, or to porous material where lattice water or neutral larger molecules are clathrated.

  19. Effect of hyaluronic acid molecular weight on the morphology of quantum dot-hyaluronic acid conjugates.

    PubMed

    Kim, Jiseok; Park, Kitae; Hahn, Sei Kwang

    2008-01-01

    The morphological analysis of novel quantum dot-hyaluronic acid (QDot-HA) conjugates was carried out with a transmission electron microscope (TEM). Adipic acid dihydrazide-modified HA (HA-ADH) was synthesized and conjugated to quantum dots (QDots) having carboxyl terminal ligands which were activated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysulfosuccinimide (sulfo-NHS). HA molecules with a molecular weight (MW) of 20K, 234 K and 3000 K were used to investigate the effect of MW on the morphology of QDot-HA conjugates. The TEM micrographs of QDot-HA conjugates showed branched and multi-layered chain type morphology formed by inter- and intra-molecular conjugation of QDots to HA molecules. The size of QDot-HA conjugate increased with the MW of HA. QDot-HA conjugate could be successfully used for real-time bio-imaging of HA derivatives in nude mice. The novel QDot-HA conjugate will be further used to investigate the biological roles of HA with a different MW in the body.

  20. 78 FR 33748 - Diisopropyl Adipate; Exemption From the Requirement of a Tolerance

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-05

    ... manufacturer, or pesticide manufacturer. The following list of North American Industrial Classification System... day oral toxicity study, male rats were given 0, 0.1, 1 or 5% adipic acid and female rats were given 0... growth retardation in males. In a 19 week oral toxicity study in rats, each rat was given 0, 50, 100,...

  1. Combined anticalcification treatment of bovine pericardium with decellularization and hyaluronic acid derivative.

    PubMed

    Zhu, Deyi; Jin, Liqiang; Wang, Xuemei; Xu, Li; Liu, Tianqi

    2014-01-01

    The objective of this work was to evaluate the effect of decellularization and hyaluronic acid derivative on the improvement of anticalcification of glutaraldehyde fixed bovine pericardium (GFBP) using a rat subcutaneous implantation model A cell extraction process was employed to remove the cells and cellular components from bovine pericardium (BP), leaving a framework of largely insoluble collagen. Then acellular BP was cross-linked by glutaraldehyde solution and treated with hyaluronic acid derivative (HA-ADH) which was obtained by coupling adipic dihydrazide (ADH) on-COOH of hyaluronic acid (HA). The results of in vivo calcification tests showed that the calcium content was decreased dramatically by decellularization alone (from 28.07 ± 18.87 to 2.44 ± 0.55 μg Ca/mg dry tissue after 8 weeks' implantation), and even less concentration was shown by the combination of HA derivative treatment and decellularization (GFaBP-HA group) (0.25 ± 0.08 μg Ca/mg dry tissue after 8 weeks' implantation). In addition, GFaBP-HA group not only presented a lower degree of calcification, but also showed lower ratios of Ca/P molar, which corresponded to amorphous calcium phosphates. The obtained results indicated that GFaBP-HA was a potential candidate for the manufacture of anticalcification bioprostheses.

  2. Selected properties of acetylated adipate of retrograded starch.

    PubMed

    Zięba, T; Gryszkin, A; Kapelko, M

    2014-01-01

    Native potato starch (NS) and retrograded starch (R - obtained via freezing and defrosting of a starch paste) were used to prepare starch acetates: NS-A and R-A, and then acetylated distarch adipates: NS-ADA and R-ADA. The chemically-modified preparations produced from retrograded starch (R-A; R-ADA) were characterized by a higher degree of esterification compared to the modified preparations produced under the same conditions from native potato starch (NS-A; NS-ADA). Starch resistance to amylolysis was observed to increase (to 30-40 g/100 g) as a result of starch retrogradation and acetylation. Starch cross-linking had a significant impact on the increased viscosity of the paste in the entire course of pasting characteristics and on the increased values of rheological coefficients determined from the equations describing flow curves. The produced preparation of acetylated retrograded starch cross-linked with adipic acid (R-ADA) may be deemed an RS3/4 preparation to be used as a food thickening agent.

  3. Comparison of the hydrogen-bond patterns in 2-amino-1,3,4-thiadiazolium hydrogen oxalate, 2-amino-1,3,4-thiadiazole-succinic acid (1/2), 2-amino-1,3,4-thiadiazole-glutaric acid (1/1) and 2-amino-1,3,4-thiadiazole-adipic acid (1/1).

    PubMed

    Matulková, Irena; Císařová, Ivana; Němec, Ivan; Fábry, Jan

    2014-10-01

    The X-ray single-crystal structure determinations of the chemically related compounds 2-amino-1,3,4-thiadiazolium hydrogen oxalate, C2H4N3S(+)·C2HO4(-), (I), 2-amino-1,3,4-thiadiazole-succinic acid (1/2), C2H3N3S·2C4H6O4, (II), 2-amino-1,3,4-thiadiazole-glutaric acid (1/1), C2H3N3S·C5H8O4, (III), and 2-amino-1,3,4-thiadiazole-adipic acid (1/1), C2H3N3S·C6H10O4, (IV), are reported and their hydrogen-bonding patterns are compared. The hydrogen bonds are of the types N-H···O or O-H···N and are of moderate strength. In some cases, weak C-H···O interactions are also present. Compound (II) differs from the others not only in the molar ratio of base and acid (1:2), but also in its hydrogen-bonding pattern, which is based on chain motifs. In (I), (III) and (IV), the most prominent feature is the presence of an R2(2)(8) graph-set motif formed by N-H···O and O-H···N hydrogen bonds, which are present in all structures except for (I), where only a pair of N-H···O hydrogen bonds is present, in agreement with the greater acidity of oxalic acid. There are nonbonding S···O interactions present in all four structures. The difference electron-density maps show a lack of electron density about the S atom along the S···O vector. In all four structures, the carboxylic acid H atoms are present in a rare configuration with a C-C-O-H torsion angle of ∼0°. In the structures of (II)-(IV), the C-C-O-H torsion angle of the second carboxylic acid group has the more common value of ∼|180|°. The dicarboxylic acid molecules are situated on crystallographic inversion centres in (II). The Raman and IR spectra of the title compounds are presented and analysed.

  4. Effect of Alcohol Structure on the Optimum Condition for Novozym 435-Catalyzed Synthesis of Adipate Esters

    PubMed Central

    Abdul Rahman, Mohd Basyaruddin; Chaibakhsh, Naz; Basri, Mahiran

    2011-01-01

    Immobilized Candida antarctica lipase B, Novozym 435, was used as the biocatalyst in the esterification of adipic acid with four different isomers of butanol (n-butanol, sec-butanol, iso-butanol, and tert-butanol). Optimum conditions for the synthesis of adipate esters were obtained using response surface methodology approach with a four-factor-five-level central composite design concerning important reaction parameters which include time, temperature, substrate molar ratio, and amount of enzyme. Reactions under optimized conditions has yielded a high percentage of esterification (>96%) for n-butanol, iso-butanol, and sec-butanol, indicating that extent of esterification is independent of the alcohol structure for primary and secondary alcohols at the optimum conditions. Minimum reaction time (135 min) for achieving maximum ester yield was obtained for iso-butanol. The required time for attaining maximum yield and also the initial rates in the synthesis of di-n-butyl and di-sec-butyl adipate were nearly the same. Immobilized Candida antarctica lipase B was also capable of esterifying tert-butanol with a maximum yield of 39.1%. The enzyme is highly efficient biocatalyst for the synthesis of adipate esters by offering a simple production process and a high esterification yield. PMID:22389769

  5. Production and characterization of hyaluronic acid microparticles for the controlled delivery of growth factors using a spray/dehydration method.

    PubMed

    Babo, Pedro S; Reis, Rui L; Gomes, Manuela E

    2016-11-01

    Hyaluronic acid is the main polysaccharide present in the connective tissue. Besides its structural function as backbone of the extracellular matrix, hyaluronic acid plays staple roles in several biological processes including the modulation of inflammation and wound healing processes. The application of hyaluronic acid in regenerative medicine, either as cells and/or drug/growth factors delivery vehicles, relies on its ability to be cross-linked using a plethora of reactions, producing stable hydrogels. In this work, we propose a novel method for the production of hyaluronic acid microparticles that presents several advantages over others that have been used. Basically, droplets of hyaluronic acid solution produced with a nozzle are collected in an isopropanol dehydration bath, and stabilized after crosslinking with adipic acid dihydrazide, using a cabodiimide-based chemistry. The size and morphology of the hyaluronic acid microparticles produced by this method varied with the molecular weight and concentration of the hyaluronic acid solution, the nozzle chamber pressure, the distance between the nozzle and the crosslinking solution, and the number of crosslinking steps. The degree of crosslinking of the hyaluronic acid microparticles produced was tunable and allowed to control the rate of the degradation promoted by hyaluronidase. Moreover, the particles were loaded with platelet lysate, a hemoderivative rich in cytokines with interest for regenerative medicine applications. The hyaluronic acid microparticles showed potential to bind selectively to positively charged molecules, as the factors present in the platelet lysate. It is envisioned that these can be further released in a sustained manner by ion exchange or by the degradation of the hyaluronic acid microparticles matrix promoted by extracellular matrix remodeling.

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

    PubMed Central

    Perz, Veronika; Bleymaier, Klaus; Sinkel, Carsten; Kueper, Ulf; Bonnekessel, Melanie; Ribitsch, Doris; Guebitz, Georg M.

    2016-01-01

    The aliphatic-aromatic copolyester poly(butylene adipate-co-butylene terephthalate) (PBAT), also known as ecoflex, contains adipic acid, 1,4-butanediol and terephthalic acid and is proven to be compostable [1], [2], [3]). We describe here data for the synthesis and analysis of poly(butylene adipate-co-butylene terephthalate variants with different adipic acid:terephatalic acid ratios and 6 oligomeric PBAT model substrates. Data for the synthesis of the following oligomeric model substrates are described: mono(4-hydroxybutyl) terephthalate (BTa), bis(4-(hexanoyloxy)butyl) terephthalate (HaBTaBHa), bis(4-(decanoyloxy)butyl) terephthalate (DaBTaBDa), bis(4-(tetradecanoyloxy)butyl) terephthalate (TdaBTaBTda), bis(4-hydroxyhexyl) terephthalate (HTaH) and bis(4-(benzoyloxy)butyl) terephthalate (BaBTaBBa). Polymeric PBAT variants were synthesized with adipic acid:terephatalic acid ratios of 100:0, 90:10, 80:20, 70:30, 60:40 and 50:50. These polymeric and oligomeric substances were used as ecoflex model substrates in enzymatic hydrolysis experiments in the article “Substrate specificities of cutinases on aliphatic-aromatic polyesters and on their model substrates” [4]. PMID:26981550

  7. Synthesis, Spectroscopic Properties and Antioxidant Activity of Bis-Hydrazones and Schiff's bases Derived from Terephthalic Dihydrazide.

    PubMed

    Jois, H S Vidyashree; Kalluraya, Balakrishna; Vishwanath, T

    2015-05-01

    A series of novel Schiff base containing bis-1,2,4-triazole and bis-hydrazone derived from terephthalic dihydrazide was synthesized. All the newly synthesized compounds were characterized by (1)H, (13)C NMR, mass spectra, FTIR and elemental analysis. UV-vis spectra and fluorescent spectra of the compounds were recorded. The effect of substituent such as electron withdrawing and electron donating groups on the fluorescent spectra was studied. Also, the comparative discussion on fluorescent spectra of Schiff's base and hydrazones has been described. The antioxidant activity of the compounds revealed that compound 5c and 5f are the most potent compounds in this series.

  8. The multiple acyl-coenzyme A dehydrogenation disorders, glutaric aciduria type II and ethylmalonic-adipic aciduria. Mitochondrial fatty acid oxidation, acyl-coenzyme A dehydrogenase, and electron transfer flavoprotein activities in fibroblasts.

    PubMed Central

    Amendt, B A; Rhead, W J

    1986-01-01

    The multiple acyl-coenzyme A (CoA) dehydrogenation disorders (MAD) include severe (S) and mild (M) variants, glutaric aciduria type II (MAD:S) and ethylmalonic-adipic aciduria (MAD:M). Intact MAD:M mitochondria oxidized [1-14C]octanoate, [1-14C]palmityl-CoA, and [1,5-14C]glutarate at 20-46% of control levels; MAD:S mitochondria oxidized these three substrates at 0.4-18% of control levels. In MAD:M mitochondria, acyl-CoA dehydrogenase (ADH) activities were similar to control, whereas MAD:S ADH activities ranged from 38% to 73% of control. Electron transfer flavoprotein (ETF) activities in five MAD:M cell lines ranged from 29 to 51% of control (P less than 0.01); ETF deficiency was the primary enzymatic defect in two MAD:M lines. In four MAD:S patients, ETF activities ranged from 3% to 6% of control (P less than 0.001); flavin adenine dinucleotide addition increased residual ETF activity from 4% to 21% of control in a single MAD:S line (P less than 0.01). Three MAD:S patients had ETF activities ranging from 33 to 53% of control; other investigators found deficient ETF-dehydrogenase activity in these MAD:S and three of our MAD:M cell lines. PMID:3722376

  9. Development of Injectable Hyaluronic Acid/Cellulose Nanocrystals Bionanocomposite Hydrogels for Tissue Engineering Applications.

    PubMed

    Domingues, Rui M A; Silva, Marta; Gershovich, Pavel; Betta, Sefano; Babo, Pedro; Caridade, Sofia G; Mano, João F; Motta, Antonella; Reis, Rui L; Gomes, Manuela E

    2015-08-19

    Injectable hyaluronic acid (HA)-based hydrogels compose a promising class of materials for tissue engineering and regenerative medicine applications. However, their limited mechanical properties restrict the potential range of application. In this study, cellulose nanocrystals (CNCs) were employed as nanofillers in a fully biobased strategy for the production of reinforced HA nanocomposite hydrogels. Herein we report the development of a new class of injectable hydrogels composed of adipic acid dihydrazide-modified HA (ADH-HA) and aldehyde-modified HA (a-HA) reinforced with varying contents of aldehyde-modified CNCs (a-CNCs). The obtained hydrogels were characterized in terms of internal morphology, mechanical properties, swelling, and degradation behavior in the presence of hyaluronidase. Our findings suggest that the incorporation of a-CNCs in the hydrogel resulted in a more organized and compact network structure and led to stiffer hydrogels (maximum storage modulus, E', of 152.4 kPa for 0.25 wt % a-CNCs content) with improvements of E' up to 135% in comparison to unfilled hydrogels. In general, increased amounts of a-CNCs led to lower equilibrium swelling ratios and higher resistance to degradation. The biological performance of the developed nanocomposites was assessed toward human adipose derived stem cells (hASCs). HA-CNCs nanocomposite hydrogels exhibited preferential cell supportive properties in in vitro culture conditions due to higher structural integrity and potential interaction of microenvironmental cues with CNC's sulfate groups. hASCs encapsulated in HA-CNCs hydrogels demonstrated the ability to spread within the volume of gels and exhibited pronounced proliferative activity. Together, these results demonstrate that the proposed strategy is a valuable toolbox for fine-tuning the structural, biomechanical, and biochemical properties of injectable HA hydrogels, expanding their potential range of application in the biomedical field.

  10. The modification and characterization of maleic anhydride-styrene-methyl metacrylate terpolymer by poly(ethylene adipate)

    NASA Astrophysics Data System (ADS)

    Boztuğ, Ali; Basan, Satilmiş

    2007-03-01

    In this study, the functionality of maleic anhydride was utilized in the maleic anhydride-styrene-methyl metacrylate (MAStMMA) terpolymer. First, the polyester of poly(ethylene adipate), PEA, polycondensation copolymer was synthesized from ethylene glycol and adipic acid monomers. PEA was then modified on its maleic anhydride units in the MAStMMA terpolymer which has been synthesized previously. This modified copolymer was characterized by FTIR (Fourier Transform Infrared spectroscopy). The viscosimetric and thermomechanical characterization of MAStMMA terpolymer and its modified copolymer were also performed and the results were compared. The modified copolymer obtained was found to be more elastic and more soluble, and had lower viscosity and density.

  11. 21 CFR 178.3690 - Pentaerythritol adipate-stearate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Pentaerythritol adipate-stearate. 178.3690 Section 178.3690 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD ADDITIVES: ADJUVANTS, PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants...

  12. Structural characterization and thermal properties of polyamide 6.6/Mg, Al/adipate-LDH nanocomposites obtained by solid state polymerization

    SciTech Connect

    Herrero, M.; Benito, P.; Labajos, F.M.; Rives, V.; Zhu, Y.D.; Allen, G.C.; Adams, J.M.

    2010-07-15

    A new nanocomposite was obtained by dispersing an adipate-modified layered double hydroxide (Ad-LDH) with adipic acid and hexamethylene diamine. These samples were polymerized in the solid phase under a nitrogen flow for 200 min at 190 {sup o}C. The structural and compositional details of the nanocomposite were determined by powder X-ray diffraction (PXRD), fourier transform infrared (FTIR) spectroscopy, focused ion beam (FIB), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The PXRD patterns and FIB images show a partially intercalated and partially exfoliated dispersion of layered crystalline materials in the polyamide 6.6 matrix. The best dispersion level is achieved in polyamide 6.6/LDH nanocomposites with low LDH loading. Some residual tactoids and particle agglomerates are also evident at high concentration. The best thermal stability of the nanocomposites is shown by the sample with 0.1% LDH content, for which it is higher than that of pure polyamide. - Graphical abstract: A new nanocomposite was obtained by compounding an adipate-modified layered double hydroxides (LDH) with adipic acid and hexamethylene diamine. These samples were polymerized in the solid phase under a nitrogen flow for 200 min at 190 {sup o}C. The nanodispersion of LDH in polyamide 6.6 may be qualitatively estimated from the analysis and PXRD patterns and FIB images. The decomposition temperature in the nanocomposite with 0.1 % LDH increases significantly compared to that for pristine PA6.6. .

  13. Oncosecretomics coupled to bioenergetics identifies α-amino adipic acid, isoleucine and GABA as potential biomarkers of cancer: Differential expression of c-Myc, Oct1 and KLF4 coordinates metabolic changes.

    PubMed

    Bellance, Nadège; Pabst, Lisa; Allen, Genevara; Rossignol, Rodrigue; Nagrath, Deepak

    2012-11-01

    Bioenergetic profiling of tumors is a new challenge of cancer research and medicine as therapies are currently being developed. Meanwhile, methodological means must be proposed to gather information on tumor metabolism in order to adapt these potential therapies to the bioenergetic specificities of tumors. Studies performed on tumors and cancer cell lines have shown that cancer cells bioenergetics is highly variable. This profile changes with microenvironmental conditions (eg. substrate availability), the oncogenes activated (and the tumor suppressors inactivated) and the interaction with the stroma (i.e. reverse Warburg effect). Here, we assessed the power of metabolic footprinting (MFP) to unravel the bioenergetics and associated anabolic changes induced by three oncogenes, c-Myc, KLF4 and Oct1. The MFP approach provides a quantitative analysis of the metabolites secreted and consumed by cancer cells. We used ultra performance liquid chromatography for quantifying the amino acid uptake and secretion. To investigate the potential oncogene-mediated alterations in mitochondrial metabolism, we measured oxygen consumption rate and ATP production as well as the glucose uptake and lactate release. Our findings show that c-Myc deficiency initiates the Warburg effect along with a reduction of mitochondrial respiration. KLF4 deficiency also stimulated glycolysis, albeit without cellular respiration impairment. In contrast, Oct1 deficiency reduced glycolysis and enhanced oxidative phosphorylation efficiency. MFP revealed that c-Myc, KLF4 and Oct1 altered amino acid metabolism with specific patterns. We identified isoleucine, α-aminoadipic acid and GABA (γ-aminoisobutyric acid) as biomarkers related. Our findings establish the impact of Oct1, KLF4 and c-Myc on cancer bioenergetics and evidence a link between oncosecretomics and cellular bioenergetics profile.

  14. Gelation behaviour of a bent-core dihydrazide derivative: effect of incubation temperature in chloroform and toluene.

    PubMed

    Zhang, Chunxue; Zhang, Tianren; Ji, Nan; Zhang, Yan; Bai, Binglian; Wang, Haitao; Li, Min

    2016-02-07

    In this work, a new kind of gelator, 1,3-bis[(3,4-dioctyloxy phenyl) hydrazide]phenylene (BP8-C), containing two dihydrazide units as the rigid bent-core, has been synthesized and investigated. It was demonstrated that BP8-C is an efficient gelator which can gel various organic solvents, such as ethanol, benzene, toluene, chloroform, etc. Both an opaque gel (O-gel) and a transparent gel (T-gel), which is more stable, were obtained with BP8-C in chloroform at different incubation temperatures. Kinetic data based on fluorescence spectra revealed that the T-gels showed a larger Avrami parameter (n = 1.44 at 20 °C) than that of the O-gels (n = 1.21 for gelation at temperatures below 0 °C). While BP8-C did form the opaque gel in toluene, gelation took longer at lower incubation temperatures and even precipitated out below 0 °C. The kinetic Avrami analysis on sols of BP8-C with different concentrations shows a two-phrase mechanism, i.e. the n values are between 0.88 and 1.74 followed by 1.69 and 3.01 throughout the temperature range of 5 °C and 35 °C for 5.34 mg mL(-1) BP8-C in toluene, indicating that the fibers formed first and then bundled to produce compact networks. We propose that supersaturation governs the formation of gel in chloroform and that the diffusion process denominates gelation in toluene. XRD and FT-IR measurements confirmed that the xerogels prepared at different temperatures in different solvents exhibited a Col(h) structure and that there are three molecules in one columnar slice. Our results indicate that the gelation process, morphology of the gels and thus the final properties of the gels depend strongly on the preparation conditions such as temperature, solvent, concentration, etc.

  15. ADIP ORNL contribution: 12th ADIP quarterly progress report for period October-December 1980. [Nb-1Zr

    SciTech Connect

    Puigh, R.; Duncan, D.; Ermi, A.M.; Gelles, D.; Zimmerchied, M.

    1980-01-01

    The following ADIP tasks are reported on: MFE-5 in-reactor fatigue crack growth in 316 SS in ORR, titanium alloy tensile properties after neutron irradiation in EBR-II, voids in neutron-irradiated Ti alloys, fabrication of ferritic alloys for RB-1 experiment in HFIR, microstructural examination of commercial ferritic alloys irradiated to very high fluence, microstructural examination of HT-9 archive material from the AD-2 test, and swelling of commercial alloys irradiated to a very high fluence. (DLC)

  16. Cannabinoid receptor antagonist-induced striated muscle toxicity and ethylmalonic-adipic aciduria in beagle dogs.

    PubMed

    Tomlinson, Lindsay; Tirmenstein, Mark A; Janovitz, Evan B; Aranibar, Nelly; Ott, Karl-Heinz; Kozlosky, John C; Patrone, Laura M; Achanzar, William E; Augustine, Karen A; Brannen, Kimberly C; Carlson, Kenneth E; Charlap, Jeffrey H; Dubrow, Katherine M; Kang, Liya; Rosini, Laura T; Panzica-Kelly, Julieta M; Flint, Oliver P; Moulin, Frederic J; Megill, John R; Zhang, Haiying; Bennett, Michael J; Horvath, Joseph J

    2012-10-01

    Ibipinabant (IBI), a potent cannabinoid-1 receptor (CB1R) antagonist, previously in development for the treatment of obesity, causes skeletal and cardiac myopathy in beagle dogs. This toxicity was characterized by increases in muscle-derived enzyme activity in serum and microscopic striated muscle degeneration and accumulation of lipid droplets in myofibers. Additional changes in serum chemistry included decreases in glucose and increases in non-esterified fatty acids and cholesterol, and metabolic acidosis, consistent with disturbances in lipid and carbohydrate metabolism. No evidence of CB1R expression was detected in dog striated muscle as assessed by polymerase chain reaction, immunohistochemistry, Western blot analysis, and competitive radioligand binding. Investigative studies utilized metabonomic technology and demonstrated changes in several intermediates and metabolites of fatty acid metabolism including plasma acylcarnitines and urinary ethylmalonate, methylsuccinate, adipate, suberate, hexanoylglycine, sarcosine, dimethylglycine, isovalerylglycine, and 2-hydroxyglutarate. These results indicated that the toxic effect of IBI on striated muscle in beagle dogs is consistent with an inhibition of the mitochondrial flavin-containing enzymes including dimethyl glycine, sarcosine, isovaleryl-CoA, 2-hydroxyglutarate, and multiple acyl-CoA (short, medium, long, and very long chain) dehydrogenases. All of these enzymes converge at the level of electron transfer flavoprotein (ETF) and ETF oxidoreductase. Urinary ethylmalonate was shown to be a biomarker of IBI-induced striated muscle toxicity in dogs and could provide the ability to monitor potential IBI-induced toxic myopathy in humans. We propose that IBI-induced toxic myopathy in beagle dogs is not caused by direct antagonism of CB1R and could represent a model of ethylmalonic-adipic aciduria in humans.

  17. 40 CFR 721.8079 - Isophorone diisocyanate neopentyl glycol adipate polyurethane prepolymer.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... glycol adipate polyurethane prepolymer. 721.8079 Section 721.8079 Protection of Environment ENVIRONMENTAL... adipate polyurethane prepolymer. (a) Chemical substance and significant new uses subject to reporting. (1... polyurethane prepolymer (PMN P-94-1743) is subject to reporting under this section for the significant new...

  18. 40 CFR 721.8079 - Isophorone diisocyanate neopentyl glycol adipate polyurethane prepolymer.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... glycol adipate polyurethane prepolymer. 721.8079 Section 721.8079 Protection of Environment ENVIRONMENTAL... adipate polyurethane prepolymer. (a) Chemical substance and significant new uses subject to reporting. (1... polyurethane prepolymer (PMN P-94-1743) is subject to reporting under this section for the significant new...

  19. Structural characterization and thermal properties of polyamide 6.6/Mg, Al/adipate-LDH nanocomposites obtained by solid state polymerization

    NASA Astrophysics Data System (ADS)

    Herrero, M.; Benito, P.; Labajos, F. M.; Rives, V.; Zhu, Y. D.; Allen, G. C.; Adams, J. M.

    2010-07-01

    A new nanocomposite was obtained by dispersing an adipate-modified layered double hydroxide (Ad-LDH) with adipic acid and hexamethylene diamine. These samples were polymerized in the solid phase under a nitrogen flow for 200 min at 190 °C. The structural and compositional details of the nanocomposite were determined by powder X-ray diffraction (PXRD), fourier transform infrared (FTIR) spectroscopy, focused ion beam (FIB), thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The PXRD patterns and FIB images show a partially intercalated and partially exfoliated dispersion of layered crystalline materials in the polyamide 6.6 matrix. The best dispersion level is achieved in polyamide 6.6/LDH nanocomposites with low LDH loading. Some residual tactoids and particle agglomerates are also evident at high concentration. The best thermal stability of the nanocomposites is shown by the sample with 0.1% LDH content, for which it is higher than that of pure polyamide.

  20. In vitro release of clomipramine HCl and buprenorphine HCl from poly adipic anhydride (PAA) and poly trimethylene carbonate (PTMC) blends.

    PubMed

    Dinarvand, Rassoul; Alimorad, Mohammed Massoud; Amanlou, Massoud; Akbari, Hamid

    2005-10-01

    Controlled drug-delivery technology is concerned with the systematic release of a pharmaceutical agent to maintain a therapeutic level of the drug in the body for modulated and/or prolonged periods of time. This may be achieved by incorporating the therapeutic agent into a degradable polymer vehicle, which releases the agent continuously as the matrix erodes. In this study, poly trimethylene carbonate (PTMC), an aliphatic polycarbonate, and poly adipic anhydride (PAA), an aliphatic polyanhydride, were synthesized via melt condensation and ring-opening polymerization of trimethylene carbonate and adipic acid, respectively. The release of clomipramine HCl and buprenorphine HCl from discs prepared with the use of PTMC-PAA blends in phosphate buffer (pH 7.4) are also described. Clomipramine HCl and buprenorphine HCl were both used as hydrophilic drug models. Theoretical treatment of the data with the Peppas model revealed that release of clomipramine HCl (5%) in devices containing 70% PTMC or more followed a Fickian diffusion model. However, the releases of buprenorphine HCl (5%) in the same devices were anomalous. For devices containing 50% and more PAA, surface erosion may play a significant role in the release of both molecules.

  1. [The synthesis of RGD peptide derivatives containing glutaric and adipic residues].

    PubMed

    Vigorov, A Iu; Demin, A M; Nizova, I A; Krasnov, V P

    2014-01-01

    A method of the synthesis of RGD peptide derivatives containing glutaric or adipic residues linked with α-amino group of L-arginine and allowing carrying out their coupling with other biomolecules and nanoparticles.

  2. Microwave heating for the rapid generation of glycosylhydrazides.

    PubMed

    Mallevre, F; Roget, A; Minon, T; Kervella, Y; Ropartz, D; Ralet, M C; Canut, H; Livache, T

    2013-07-17

    Conditions for simple derivatization of reducing carbohydrates via adipic acid dihydrazide microwave-assisted condensation are described. We demonstrate with a diverse set of oligo- and polysaccharides how to improve a restrictive and labor intensive conventional conjugation protocol by using microwave-assisted chemistry. We show that 5 min of microwave heating in basic or acidic conditions are adequate to generate, in increased yields, intact and functional glycosylhydrazides, whereas hours to days and acidic conditions are generally required under conventional methods.

  3. Development of silver/titanium dioxide/chitosan adipate nanocomposite as an antibacterial coating for fruit storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel nanocomposite of silver/titanium dioxide/chitosan adipate (Ag/TiO2/CS) was developed through photochemical reduction using a chitosan adipate template. Chitosan served as a reducing agent for the metal ions, and anchored metal ions by forming Ag–N coordination bonds and electrostatic attract...

  4. [Synthesis of diisooctyl adipate catalyzed by lipase-displaying Pichia pastoris whole-cell biocatalysts].

    PubMed

    Zhang, Na; Jin, Zi; Lin, Ying; Zheng, Suiping; Han, Shuangyan

    2013-07-01

    An enzyme-displaying yeast as a whole-cell biocatalyst is an alternative to immobilized enzyme, due to its low-cost preparation and simple recycle course. Here, lipase-displaying Pichia pastoris whole-cell was used as a biocatalyst to synthesize diisooctyl adipate in the non-aqueous system. The maximum productivity of diisooctyl adipate was obtained as 85.0% in a 10 mL reaction system. The yield could be reached as high as 97.8% when the reaction system was scaled up to 200 mL. The purity obtained is 98.2% after vacuum distillation. Thus, the lipase-displaying P. pastoris whole-cell biocatalyst was promising in commercial application for diisooctyl adipate synthesis in non-aqueous phase.

  5. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid.

    PubMed

    Al-Amiery, Ahmed A; Binti Kassim, Fatin A; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2016-01-22

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10(-3) M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir's adsorption isotherm. The effect of te perature on corrosion behavior in the presence of 5 × 10(-3) M inhibitor was studied in the temperature range of 30-60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl.

  6. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid

    NASA Astrophysics Data System (ADS)

    Al-Amiery, Ahmed A.; Binti Kassim, Fatin A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2016-01-01

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10-3 M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir’s adsorption isotherm. The effect of temperature on corrosion behavior in the presence of 5 × 10-3 M inhibitor was studied in the temperature range of 30-60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl.

  7. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid

    PubMed Central

    Al-Amiery, Ahmed A.; Binti Kassim, Fatin A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2016-01-01

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10−3 M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir’s adsorption isotherm. The effect of temperature on corrosion behavior in the presence of 5 × 10−3 M inhibitor was studied in the temperature range of 30–60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl. PMID:26795066

  8. [Levels of phthalates and adipates in processed foods and migration of di-isononyl adipate from polyvinyl chloride film into foods].

    PubMed

    Saito, Isao; Ueno, Eiji; Oshima, Harumi; Matsumoto, Hiroshi

    2002-06-01

    The levels of dibutyl phthalate (DBP), butylbenzyl phthalate (BBP), di-(2-ethylhexyl) phthalate (DEPHP), di-isononyl phthalate (DINP), di-(2-ethylhexyl) adipate (DEHA) and di-isononyl adipate (DINA) were determined in 50 processed foods (ham and sausage, fried dumpling and shao-mai, fish paste products, croquette and fried fish, bread, noodle, pickles, etc.). DBP, BBP, DEHP, DINP, DEHA, and DINA were contained at nd approximately 47.7, nd approximately 16.6, nd approximately 749, nd approximately 358, nd approximately 57.2 and nd approximately 20,200 ppb, respectively. High-level contamination of DINA was found in fish paste products, croquette and shao-mai, presumably because of migration from plasticized wrapping film using for food packaging. We studied the relationship between DINA migration from wrapped PVC film into fried croquette and its standing time after frying. When the croquette was wrapped immediately after frying, the migration from wrapping film into the croquette was highest (36,400 ng/g). On wrapping after standing for 5 min and 30 min, the migration level was reduced to 1/3.5 and 1/14 of the highest level, respectively.

  9. Multifunctional Nanobiocomposite of Poly[(butylene succinate)-co-adipate] and Clay.

    PubMed

    Al-Thabaiti, Shaeel A; Ray, Suprakas Sinha; Basahel, Sulaiman Nassir; Mokhtar, Mohamed

    2015-03-01

    The processing and characterization of multifunctional nanobiocomposite of biodegradable poly[(butylene succinate)-co-adipate] (PBSA) and organically modified synthetic fluorine mica (OSFM) are reported. The nanobiocomposite of PBSA with OSFM was prepared using melt- blending, and the structure and morphology of the nanocomposite were characterized using X-ray diffraction and transmission electron microscopy. The mechanical and material properties measurements showed the concurrent improvement in temperature dependence storage modulus, tensile properties, gas barrier, and thermal stability of neat PBSA after nanocomposite formation. Such improved inherent properties along with the environmentally-friendly feature are expected to widen the use of PBSA for short-term food-packaging applications.

  10. Acetylated adipate of retrograded starch as RS 3/4 type resistant starch.

    PubMed

    Kapelko-Żeberska, M; Zięba, T; Spychaj, R; Gryszkin, A

    2015-12-01

    This study was aimed at producing acetylated adipate of retrograded starch (ADA-R) with various degrees of substitution with functional groups and at determining the effect of esterification degree on resistance and pasting characteristics of the produced preparations. Paste was prepared from native potato starch, and afterwards frozen and defrosted. After drying and disintegration, the paste was acetylated and crosslinked using various doses of reagents. An increase in the total degree of esterification of the produced ADA-R-preparation caused an increase in its resistance to the action of amyloglucosidase. Viscosity of the paste produced from ADA-R-preparation in a wide range of acetylation degrees was increasing along with increasing crosslinking of starch. The study demonstrated that acetylated adipate of retrograded starch may be classified as a preparation of RS 3/4 type resistant starch (retrograded starch/chemically-modified starch) with good texture-forming properties. The conducted modification offers the possibility of modeling the level of resistance of the produced preparation.

  11. Aqueous solubility and Daphnia magna chronic toxicity of di(2-ethylhexyl) adipate.

    PubMed

    Robillard, K A; Dufresne, D L; Gorsuch, J W; Stubblefield, W A; Staples, C A; Parkerton, T F

    2008-06-01

    A water solubility of 5.5 (+/-0.22) microg/L for di(2-ethylhexyl) adipate (DEHA) was measured using the slow-stir method. This value is consistent with computer estimations and over two orders of magnitude lower than that previously determined using the shake-flask method. We performed a 21-day chronic Daphnia magna limit test at an average exposure of 4.4 microg/L in laboratory diluent water to avoid insoluble test material and avoid physical entrapment. One hundred percent of the DEHA-treated organisms survived compared to 90% survival in both the controls and solvent controls. Mean neonate reproduction was 152, 137, and 148 and mean dry weight per surviving female was 0.804, 0.779, and 0.742 mg in the DEHA treatment, control, and solvent control, respectively. No adverse effects were observed.

  12. Poly(butylene succinate-co-butylene adipate)/cellulose nanocrystal composites modified with phthalic anhydride.

    PubMed

    Zhang, Xuzhen; Zhang, Yong

    2015-12-10

    As a kind of biomass nanofiller for polymers, cellulose nanocrystal (CNC) has good mechanical properties and reinforcing capability. To improve the compatibility of poly(butylene succinate-co-butylene adipate) (PBSA)/CNC composites, phthalic anhydride was used as a compatilizer during melt mixing, leading to the significant improvement of the mechanical properties and thermal stability of the composites, which is related to the better dispersion of CNC in the composites. The addition of phthalic anhydride could accelerate the crystallization of PBSA component as evidenced by the curves of isothermal crystallization of the composites, but had little effect on the crystalline polymorphs of PBSA component. The addition of phthalic anhydride could strongly improve the hydrophobicity of the composites. The good mechanical properties, fast crystallization and improved hydrophobicity of PBSA/CNC composites with phthalic anhydride are favor to their practical commercial utilization.

  13. The influence of pressure on the photoluminescence properties of a terbium-adipate framework

    NASA Astrophysics Data System (ADS)

    Spencer, Elinor C.; Zhao, Jing; Ross, Nancy L.; Andrews, Michael B.; Surbella, Robert G.; Cahill, Christopher L.

    2013-06-01

    The influence of pressure (over the 0-4.7 GPa range) on the photoluminescence emissions and crystal structure of the known 3D terbium-adipate metal-organic framework material Tb-GWMOF6 has been evaluated by high-pressure single-crystal X-ray diffraction and spectroscopic techniques. The results from this study show that this complex lanthanide framework structure undergoes three phase transitions within the 0-4 GPa pressure range that involve alterations in the number of symmetry independent Tb3+ ion sites within the crystal lattice. These pressure induced modifications to the structure of Tb-GWMOF6 lead to pronounced changes in the profiles of the 5D4→7F5 emission spectra of this complex.

  14. Gas chromatographic-mass spectrometric determination of adipate-based polymeric plasticizers in foods.

    PubMed

    Castle, L; Mercer, A J; Gilbert, J

    1988-01-01

    A method for the quantitative determination of adipate-based polymeric plasticizers in foods is described. The procedure involves extraction from the food and transmethylation of the polymeric plasticizer to form dimethyladipate (DMA). The derivative is cleaned up by size-exclusion chromatography and determined by capillary gas chromatography-mass spectrometry with selected ion monitoring. The use of a deuterated internal standard at the extraction stage enables quantitation by stable isotope dilution. A detection limit of 0.1 mg/kg of the polymeric plasticizer in foods and a relative standard deviation of 4% have been achieved routinely. The method has been applied successfully to the analysis of cheese, sandwiches, meat, biscuits, and cake that have been in contact with polymeric plasticized poly(vinyl chloride) films.

  15. Drug incorporation and release of water soluble drugs from novel functionalized poly(glycerol adipate) nanoparticles.

    PubMed

    Puri, Sanyogita; Kallinteri, Paraskevi; Higgins, Sean; Hutcheon, Gillian A; Garnett, Martin C

    2008-01-04

    We have previously demonstrated the ability of poly(glycerol adipate) backbone (PGA) and PGA polymer backbone substituted with varying amounts of pendant C(18) chain length acyl groups to yield Dexamethasone phosphate DXMP loaded nanoparticles. The aim of this study was to obtain a deeper understanding of the underlying principles responsible for good drug incorporation and controlled release of drugs from poly (glycerol adipate) (PGA) nanoparticles. We compared the incorporation of the water soluble drugs DXMP and Cytosine arabinoside (CYT-ARA) in both unmodified and substituted PGA polymers. We investigated the effect of change in acyl group chain length and the degree of substitution on the physicochemical properties, drug loading and release of DXMP and CYT-ARA. Nanoparticles were prepared by the interfacial deposition technique and the simultaneous emulsification method. Amongst the nanoparticles prepared using acylated polymers with varying chain lengths (C(2) to C(10)) for DXMP incorporation, polymers with acyl group chain lengths containing 8 carbon atoms (C(8)) showed maximum drug incorporation. Amongst the C(8) series, polymers with 100% acylation provided both good drug incorporation and a controlled release for DXMP while for CYT-ARA it was the unsubstituted polymer backbone that had maximum drug loading and slower release. A number of inter-related factors are responsible for producing particles with particular size, zeta potential, drug loading and release characteristics. Drug loading and release from nanoparticles are primarily influenced by the nature of interactions between the drug and polymers which in turn depend upon the type of drug used and the physical chemistry of the polymer.

  16. Second virial coefficient of poly(bisphenol-A diglycidyl ether-co-adipic acid)

    NASA Astrophysics Data System (ADS)

    Wohlfarth, Ch.

    This document is part of Subvolume D2 'Polymer Solutions - Physical Properties and their Relations I (Thermodynamic Properties: PVT -Data and miscellaneous Properties of polymer Solutions) of Volume 6 `Polymers' of Landolt-Börnstein - Group VIII `Advanced Materials and Technologies'.

  17. Limestone/adipic acid FGD and stack opacity reduction pilot plant tests at Big Rivers

    SciTech Connect

    Laslo, D.; Bakke, E.; Chisholm, E.

    1984-01-01

    Big Rivers Electric Corporation (BREC) contracted Peabody Process Systems, Inc. (PPSI) to install a flue gas cleaning (FGC) pilot plant at the BREC R.D. Green Station Unit No. 2 located at Sebree, KY. A six month test program was completed demonstrating technology for: alternatives to using lime as an alkali; methods for improving cake dewatering; identification of the causes of high stack opacity; and methods for the reduction of high stack opacity. This paper presents highlights extracted from the reports submitted by PPSI to BREC on this test program. BREC was primarily interested in reduction of operating costs, if possible, by using an alkali less expensive than lime, and by improving the poor dewatering characteristic inherent in a dolomitic lime system. BREC was also within compliance for particulate emissions and opacity in the duct after the dry electrostatic precipitator, but not in compliance with the stack opacity regulation, and therefore wanted to investigate methods for stack opacity reduction.

  18. Reproductive and Developmental Toxicity Screening Test of Ethyl Hydrogen Adipate in Rats

    PubMed Central

    Nam, Chunja; Hwang, Jae-Sik; Han, Kyoung-Goo; Jo, Eunhye; Yoo, Sun-kyoung; Eom, Ig-Chun; Kang, Jong-Koo

    2016-01-01

    This study aimed to evaluate the potential toxicity and safety of ethyl hydrogen adipate (EHA) by determining its effect on the reproductive function and development of Sprague-Dawley (SD) rats at dose levels of 0 (control), 200, 400, and 800 mg/kg/day. One male and five females of the 800 mg/kg/day died. Body weight loss was observed in the males of the 800 mg/kg/day and in females of the 400 and 800 mg/kg/day. In addition, mating indices decreased and pre-implantation loss rates increased in parental animals of the 400 and 800 mg/kg/day. The gestation index decreased in the male and female rats of the 800 mg/kg/day. Moreover, the body weight of the pups from the 800 mg/kg/day group decreased on post-parturition day 4. These results indicated that the no-observed-adverse-effect level of EHA for parental males and females was 400 mg/kg/day and 200 mg/kg/day, respectively, and that for pups was 400 mg/kg/day. PMID:27818735

  19. Pyridoxine-dependent epilepsy with elevated urinary α-amino adipic semialdehyde in molybdenum cofactor deficiency.

    PubMed

    Struys, Eduard Alexander; Nota, Benjamin; Bakkali, Abdellatif; Al Shahwan, Saad; Salomons, Gajja Sophi; Tabarki, Brahim

    2012-12-01

    α-Amino adipic semialdehyde (α-AASA) accumulates in body fluids from patients with pyridoxine-dependent epilepsy because of mutations in antiquitin (ALDH7A1) and serves as the biomarker for this condition. We have recently found that the urinary excretion of α-AASA was also increased in molybdenum cofactor and sulfite oxidase deficiencies. The seizures in pyridoxine-dependent epilepsy are caused by lowered cerebral levels of pyridoxal-5-phosphate (PLP), the bioactive form of pyridoxine (vitamin B(6)), which can be corrected by the supplementation of pyridoxine. The nonenzymatic trapping of PLP by the cyclic form of α-AASA is causative for the lowered cerebral PLP levels. We describe 2 siblings with clinically evident pyridoxine-responsive seizures associated with increased urinary excretion of α-AASA. Subsequent metabolic investigations revealed several metabolic abnormities, all indicative for molybdenum cofactor deficiency. Molecular investigations indeed revealed a known homozygous mutation in the MOCS2 gene. Based upon the clinically evident pyridoxine-responsive seizures in these 2 siblings, we recommend considering pyridoxine supplementation to patients affected with molybdenum cofactor or sulfite oxidase deficiencies.

  20. Characterization of a poly(butylene adipate-co-terephthalate)- hydrolyzing lipase from Pelosinus fermentans.

    PubMed

    Biundo, Antonino; Hromic, Altijana; Pavkov-Keller, Tea; Gruber, Karl; Quartinello, Felice; Haernvall, Karolina; Perz, Veronika; Arrell, Miriam S; Zinn, Manfred; Ribitsch, Doris; Guebitz, Georg M

    2016-02-01

    Certain α/β hydrolases have the ability to hydrolyze synthetic polyesters. While their partial hydrolysis has a potential for surface functionalization, complete hydrolysis allows recycling of valuable building blocks. Although knowledge about biodegradation of these materials is important regarding their fate in the environment, it is currently limited to aerobic organisms. A lipase from the anaerobic groundwater organism Pelosinus fermentans DSM 17108(PfL1) was cloned and expressed in Escherichia coli BL21-Gold (DE3) and purified from the cell extract. Biochemical characterization with small substrates showed thermoalkalophilic properties (Topt=50 °C, pHopt=7.5) and higher activity towards para-nitrophenyl octanoate (12.7 U mg(-1)) compared to longer and shorter chain lengths (C14 0.7 U mg(-1) and C2 4.3 U mg(-1), respectively). Crystallization and determination of the 3-D structure displayed the presence of a lid structure and a zinc ion surrounded by an extra domain. These properties classify the enzyme into the I.5 lipase family. PfL1 is able to hydrolyze poly(1,4-butylene adipate-co-terephthalate) (PBAT) polymeric substrates. The hydrolysis of PBAT showed the release of small building blocks as detected by liquid chromatography mass spectrometry (LC-MS). Protein dynamics seem to be involved with lid opening for the hydrolysis of PBAT by PfL1.

  1. Di-(2-ethylhexyl) adipate in selected total diet food composite samples.

    PubMed

    Cao, Xu-Liang; Zhao, Wendy; Churchill, Robin; Dabeka, Robert

    2013-11-01

    Polyvinyl chloride (PVC) food-wrapping films plasticized with di-(2-ethylhexyl) adipate (DEHA) are commonly used by grocery stores in Canada to rewrap meat, poultry, fish, cheese, and other foods. DEHA was assessed as part of the Government of Canada's Chemicals Management Plan. The main source of exposure for most age groups was expected to be food. Although the margin of exposure from food and beverages is considered to be adequately protective, the Government of Canada committed to performing targeted surveys of DEHA in foods and food packaging materials to better define Canadian exposure to DEHA through dietary intake. In order to determine whether more-comprehensive targeted surveys on DEHA in foods should be conducted, 26 food composite samples from the 2011 Canadian total diet study were selected and analyzed for DEHA using a method based on solvent and dispersive solid-phase extraction and gas chromatography-mass spectrometry. These 26 food composites include cheese, meat, poultry, fish, and fast foods, and PVC films were likely used in packaging the individual foods used to make the composites. DEHA was detected in most of the meat, poultry, and fish composite samples, with the highest concentration found in ground beef (11 μg/g), followed by beef steak (9.9 μg/g), freshwater fish (7.8 μg/g), poultry liver pâté (7.4 μg/g), fresh pork (6.9 μg/g), cold cuts and luncheon meats (2.8 μg/g), veal cutlets (2.1 μg/g), roast beef (1.3 μg/g), lamb (1.2 μg/g), and organ meats (0.20 μg/g). Targeted surveys should be conducted to investigate the presence of DEHA in various foods packaged with PVC films in more detail and provide updated occurrence data for accurate human exposure assessment.

  2. Crystal engineering of analogous and homologous organic compounds: hydrogen bonding patterns in trimethoprim hydrogen phthalate and trimethoprim hydrogen adipate

    PubMed Central

    Muthiah, Packianathan Thomas; Francis, Savarimuthu; Rychlewska, Urszula; Warżajtis, Beata

    2006-01-01

    Background Trimethoprim [2,4-diamino-5-(3',4',5'-trimethoxybenzyl)pyrimidine] is an antifolate drug. It selectively inhibits the bacterial dihydrofolate reductase (DHFR) enzyme. Results In the crystal structures of trimethoprim (TMP)-hydrogen phthalate (1) and trimethoprim-hydrogen adipate (2), one of the N atoms of the pyrimidine ring is protonated and it interacts with the deprotonated carboxylate oxygens through a pair of nearly parallel N-H...O hydrogen bonds to form a fork-like interaction. In the compound 1, the pyrimidine moieties of the TMP cations are centrosymmetrically paired through a pair of N-H...N hydrogen bonds involving 4-amino group and the N (N3) atom of the pyrimidine rings to form a 8-membered hydrogen bonded ring [R22(8)]. The 4-amino group of one TMP moiety and 2-amino group of another TMP moiety (both moieties are members of a base pair) are bridged by the carbonyl oxygen of the phthalate moiety through N-H...O hydrogen bonds forming 8-membered hydrogen-bonded ring [R22(8)]. The characteristic hydrogen-bonded rings observed in the structure aggregate into a supramolecular ladder consisting of a pair of chains, each of which is built up of alternate TMP and hydrogen phthalate ions. In the compound 2, two TMP cations and two hydrogen adipate anions are arranged about an inversion center so that the complementary DDAA (D = donor, A = acceptor) arrays of quadruple hydrogen-bonding patterns are formed. The head-to-tail arrangement of the hydrogen adipate ions leads to a hydrogen-bonded supramolecular chain. From crystal engineering point of view, it is interesting to note that the compound 1 has a hydrogen-bonded network remarkably identical with its aliphatic analogue, trimethoprim hydrogen maleate. Similarly the compound 2, resembles its homolog trimethoprim hydrogen glutarate. Conclusion In the crystal structure of trimethoprim hydrogen phthalate, the hydrogen-bonded network is remarkably identical with its aliphatic analogue, trimethoprim

  3. Oxidative carbonylation - A new syngas route to sebacic acid

    SciTech Connect

    Kesling, H.S.

    1986-03-01

    Conventional technology for sebacic acid manufacture involves caustic soda decomposition of ricinoleic acid at high temperature. Principal co-products include 2-octanol and glycerine. Castor oil, which is the natural source for ricinoleic acid, is subject to price fluctuation due to cyclic crop production and protectionist policies by foreign governments. Castor oil technology is also at disadvantage because the overall product yield is low (<80%) and co-product 2-octanol must compete with cheap 2-ethylhexanol in plasticizer applications. These and other factors have resulted in a significant decline in the sebacic acid market from about 30 MM lbs. per year in the 70's to less that 5 MM lbs. in the 80's. Thus, there is a clear need for a new process to produce sebacic acid from cheap and readily available petrochemicals. In Japan, the need for new technology was answered by the development of an electrolytic route to sebacic acid. The Kolbe type electrolytic process involves dimerization of adipic acid half methyl ester salt to give dimethyl sebacate. The dimerization proceeds in 92% yield with 90% selectivity based on the adipate half ester. The main drawbacks of this process are the cost of energy utilized by the electrolytic process and the cost of adipic acid. A recent Chem Systems report indicates a small advantage for the Asahi electrolytic process with ample room for new technology development.

  4. Economics of retrofitting Big Rivers Electric Corporation's lime-based FGD (Flue-Gas Desulfurization) system to organic-acid-enhanced limestone operations. Final report, August 1983-December 1984

    SciTech Connect

    Laslo, D.; Ostroff, N.; Foley, R.; Schreyer, D.G.

    1985-04-01

    The report describes the site specific changes required to convert an existing lime FGD system to a limestone system enhanced by dibasic acid (DBA) or adipic acid, and the costs of making such a change. In 1982-83, pilot plant tests were conducted at the R. D. Green Station of Big Rivers Electric Corporation (BREC). The final report of the pilot testing included comparisons of the operating costs of a lime-based full-size absorber, to those of a retrofit limestone system enhanced with DBA or adipic acid. Results of this analysis indicate that an annual cost savings of $2.6 million could be achieved by converting the existing BREC lime system to an adipic-acid-enhanced limestone system, and an annual savings of $3.1 million could be achieved by converting to a DBA-enhanced system.

  5. By-products of electrochemical synthesis of suberic acid

    SciTech Connect

    Shirobokova, O.I.; Adamov, A.A.; Freidlin, G.N.; Antonenko, N.S.; Grudtsyn, Yu.D.

    1988-05-10

    By-products of the electrochemical synthesis of dimethyl suberate from glutaric anhydride were studied. This is isolated by thermal dehydration of a mixture of lower dicarboxylic acids that are wastes from the production of adipic acid. To isolate the by-products, they used the methods of vacuum rectification and preparative gas-liquid chromatography, and for their identification, PMR, IR spectroscopy, gas-liquid chromatography, and other known physicochemical methods of investigation.

  6. 40 CFR 98.50 - Definition of source category.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.50 Definition of source category. The adipic acid production source category consists of all adipic acid production facilities that use oxidation to produce adipic acid....

  7. 40 CFR 98.50 - Definition of source category.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.50 Definition of source category. The adipic acid production source category consists of all adipic acid production facilities that use oxidation to produce adipic acid....

  8. Effects of chemical versus enzymatic processing of kenaf fibers on poly(hydroxybutyrate-co-valerate)/poly(butylene adipate-co-terephthalate) composite properties

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of fiber retting on crystallization and mechanical performance was investigated. A poly(hydroxybutyrate-co-valerate) (PHBV) and poly(butylene adipate-co-terephthalate) (PBAT) blend in a 80/20 ratio was modified using 5% by weight kenaf (Hibiscus cannabinus L.) fiber. Fibers were retted us...

  9. Conformations, energies, and intramolecular hydrogen bonds in dicarboxylic acids: implications for the design of synthetic dicarboxylic acid receptors.

    PubMed

    Nguyen, Thanh Ha; Hibbs, David E; Howard, Siân T

    2005-09-01

    The various conformers of the dicarboxylic acids HO2C--(CH2)n--CO2H, n = 1-4, were obtained using density functional methods (DFT), both in the gas phase and in the aqueous phase using a polarized continuum model (PCM). Several new conformers were identified, particularly for the two larger molecules glutaric (n = 3) and adipic acid (n =4). The PCM results show that the stability of most conformers were affected, many becoming unstable in the aqueous phase; and the energy ordering of conformers is also different. The results suggest that conformational preferences could be important in determining the design and stability of appropriate synthetic receptors for glutaric and adipic acid. Geometry changes between gas and aqueous phases were most marked in those conformers containing an intramolecular hydrogen bond. Additional calculations have probed the strength of intramolecular hydrogen bonds in these dicarboxylic acids. In the cases of glutaric and adipic acid, the strength of the intramolecular hydrogen bond were estimated to be around 28-29 kJ/mol, without any vibrational energy correction. The intramolecular hydrogen bond energies in malonic and succinic acid were also estimated from the calculated H-bond distances using an empirical relationship. Intramolecular H-bond redshifts of 170-250 cm(-1) have been estimated from the results of the harmonic frequency analyses.

  10. Ruthenium-catalyzed oxidation of alkenes, alkynes, and alcohols to organic acids with aqueous hydrogen peroxide.

    PubMed

    Che, Chi-Ming; Yip, Wing-Ping; Yu, Wing-Yiu

    2006-09-18

    A protocol that adopts aqueous hydrogen peroxide as a terminal oxidant and [(Me3tacn)(CF3CO2)2Ru(III)(OH2)]CF3CO2 (1; Me3tacn = 1,4,7-trimethyl-1,4,7-triazacyclononane) as a catalyst for oxidation of alkenes, alkynes, and alcohols to organic acids in over 80% yield is presented. For the oxidation of cyclohexene to adipic acid, the loading of 1 can be lowered to 0.1 mol %. On the one-mole scale, the oxidation of cyclohexene, cyclooctene, and 1-octanol with 1 mol % of 1 produced adipic acid (124 g, 85% yield), suberic acid (158 g, 91% yield), and 1-octanoic acid (129 g, 90% yield), respectively. The oxidative C=C bond-cleavage reaction proceeded through the formation of cis- and trans-diol intermediates, which were further oxidized to carboxylic acids via C-C bond cleavage.

  11. Alterations of amino Acid level in depressed rat brain.

    PubMed

    Yang, Pei; Li, Xuechun; Ni, Jian; Tian, Jingchen; Jing, Fu; Qu, Changhai; Lin, Longfei; Zhang, Hui

    2014-10-01

    Amino-acid neurotransmitter system dysfunction plays a major role in the pathophysiology of depression. Several studies have demonstrated the potential of amino acids as a source of neuro-specific biomarkers could be used in future diagnosis of depression. Only partial amino acids such as glycine and asparagine were determined from certain parts of rats' brain included hippocampi and cerebral cortex in previous studies. However, according to systematic biology, amino acids in different area of brain are interacted and interrelated. Hence, the determination of 34 amino acids through entire rats' brain was conducted in this study in order to demonstrate more possibilities for biomarkers of depression by discovering other potential amino acids in more areas of rats' brain. As a result, 4 amino acids (L-aspartic acid, L-glutamine, taurine and γ-amino-n-butyric acid) among 34 were typically identified as potentially primary biomarkers of depression by data statistics. Meanwhile, an antidepressant called Fluoxetine was employed to verify other potential amino acids which were not identified by data statistics. Eventually, we found L-α-amino-adipic acid could also become a new potentially secondary biomarker of depression after drug validation. In conclusion, we suggested that L-aspartic acid, L-glutamine, taurine, γ-amino-n-butyric acid and L-α-amino-adipic acid might become potential biomarkers for future diagnosis of depression and development of antidepressant.

  12. Photoelectron spectroscopy of carbonyls: saturated normal dicarboxylic acids

    SciTech Connect

    Chattopadhyay, S.; Meeks, J.L.; Findley, G.L.; McGlynn, S.P.

    1981-04-16

    The ultraviolet photoelectron spectra (UPS) of oxalic, malonic, succinic, glutaric, and adipic acids, and various of their simple derivatives, are presented and discussed. The four lowest-energy ionization events, (I(n/sub +/), I(n/sub -), I (..pi../sub +/), I(..pi../sub -/)), are assigned in all cases. Higher ionization events are not assigned because of molecule-limited resolution in the higher-energy UPS region.

  13. Intra-molecular cross-linking of acidic residues for protein structure studies.

    SciTech Connect

    Kruppa, Gary Hermann; Young, Malin M.; Novak, Petr; Schoeniger, Joseph S.

    2005-03-01

    Intra-molecular cross-linking has been suggested as a method of obtaining distance constraints that would be useful in developing structural models of proteins. Recent work published on intra-molecular cross-linking for protein structural studies has employed commercially available primary amine selective reagents that can cross-link lysine residues to other lysine residues or the amino terminus. Previous work using these cross-linkers has shown that for several proteins of known structure, the number of cross-links that can be obtained experimentally may be small compared to what would be expected from the known structure, due to the relative reactivity, distribution, and solvent accessibility of the lysines in the protein sequence. To overcome these limitations we have investigated the use of cross-linking reagents that can react with other reactive sidechains in proteins. We used 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) to activate the carboxylic acid containing residues, aspartic acid (D), glutamic acid (E), and the carboxy terminus (O), for cross-linking reactions. Once activated, the DEO sidechains can react to form 'zero-length' cross-links with nearby primary amine containing resides, lysines (K) and the amino terminus (X), via the formation of a new amide bond. We also show that the EDC-activated DEO sidechains can be cross-linked to each other using dihydrazides, two hydrazide moieties connected by an alkyl cross-linker ann of variable length. Using these reagents, we have found three new 'zero-length' cross-links in ubiquitin consistent with its known structure (M1-E16, M1-E18, and K63-E64). Using the dihydrazide cross-linkers, we have identified 2 new cross-links (D21-D32 and E24-D32) unambiguously. Using a library of dihydrazide cross-linkers with varying arm length, we have shown that there is a minimum arm length required for the DEO-DEO cross-links of 5.8 angstroms. These results show that additional structural information

  14. Oxidation of cyclohexanediol derivatives with 12-tungstophosphoric acid-hydrogen peroxide system.

    PubMed

    Fujitani, Kango; Mizutani, Toshihiro; Oida, Tatsuo; Kawase, Tokuzo

    2009-01-01

    Oxidation of cyclohexanediol derivatives with 12-tungstophospholic acid-hydrogen peroxide system was investigated focusing on a reaction mechanism in the preparation of dicarboxylic acids from olefin because oxidative cleavage of vicinal diols would be a rate-determining step in oxidative cleavage of carbon-carbon double bonds. trans-1,2-Cyclohexanediol (DHC) was converted to adipic acid almost quantatively, while 1-hydroxy-2-methoxycyclohexane (HMC) gave a mixture of adipic acid, glutaric acid and monomethyl adipate. In the case of 1,4-cyclohexanediol, 4-hydroxy-cyclohexanone and many hyperoxidated products were obtained. Based on results for HMC, it is concluded that following route would be also reasonable in oxidative cleavage of vicinal diol with 12-tungstophospholic acid-hydrogen peroxide system: (1) first oxidation of vicinal diol to alpha-hydroxyketone, (2) nucleophilic attack of hydrogen peroxide attacks to carbonyl carbon, (3) Baiyer-Villiger rearrangement of dihydroxy-hydroperoxide to a cyclic ester, (4) hydrolysis and final oxidation to dicarboxylic acid.

  15. Matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectra of poly(butylene adipate).

    PubMed

    Rizzarelli, Paola; Puglisi, Concetto; Montaudo, Giorgio

    2006-01-01

    Matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS/MS) was employed to analyze four poly(butylene adipate) (PBAd) oligomers and to investigate their fragmentation pathways as a continuation of our work on the MALDI-TOF/TOF-MS/MS study of synthetic polymers. MALDI-TOF/TOF-MS/MS analysis was performed on oligomers terminated by carboxyl and hydroxyl groups, methyl adipate and hydroxyl groups, dihydroxyl groups, and dicarboxyl groups. The sodium adducts of these oligomers were selected as precursor ions. Different end groups do not influence the fragmentation of sodiated polyester oligomers and similar series of product ions were observed in all the MALDI-TOF/TOF-MS/MS spectra. According to the structures of the most abundant product ions identified in the present work, three fragmentation pathways have been proposed to occur most frequently in PBAd: beta-hydrogen-transfer rearrangement, leading to the selective cleavage of the --O--CH(2)-- bonds; --CH(2)--CH(2)-- (beta--beta) bond cleavage in the adipate moiety; and ester bond scission.

  16. Synthesis of biocompatible poly(ɛ-caprolactone)- block-poly(propylene adipate) copolymers appropriate for drug nanoencapsulation in the form of core-shell nanoparticles.

    PubMed

    Nanaki, Stavroula G; Pantopoulos, Kostas; Bikiaris, Dimitrios N

    2011-01-01

    Poly(propylene adipate)-block-poly(ɛ-caprolactone) copolymers were synthesized using a combination of polycondensation and ring-opening polymerization of ɛ-caprolactone in the presence of poly(propylene adipate). Gel permeation chromatography was used for molecular weight determination, whereas hydrogen-1 nuclear magnetic resonance and carbon-13 nuclear magnetic resonance spectroscopy were employed for copolymer characterization and composition evaluation. The copolymers were found to be block while their composition was similar to the feeding ratio. They formed semicrystalline structures, while only poly(ɛ-caprolactone) formed crystals, as shown by wide angle X-ray diffraction. Differential scanning calorimetry data suggest that the melting point and heat of fusion of copolymers decreased by increasing the poly(propylene adipate) amount. The synthesized polymers exhibited low cytotoxicity and were used to encapsulate desferrioxamine, an iron-chelating drug. The desferrioxamine nanoparticles were self-assembled into core shell structures, had mean particle size <250 nm, and the drug remained in crystalline form. Further studies revealed that the dissolution rate was mainly related to the melting temperature, as well as to the degree of crystallinity of copolymers.

  17. Chemical modification of zinc hydroxide nitrate and Zn-Al-layered double hydroxide with dicarboxylic acids.

    PubMed

    Arizaga, Gregorio Guadalupe Carbajal; Mangrich, Antonio Salvio; da Costa Gardolinski, José Eduardo Ferreira; Wypych, Fernando

    2008-04-01

    A zinc hydroxide nitrate (ZHN), Zn5(OH)8(NO3)2.2H2O, and a layered double hydroxide (LDH), Zn/Al-NO3 were doped with 0.2 mol% of Cu2+ during alkaline chemical precipitation. Both compounds were intercalated with adipate ((-)OOC(CH2)4COO(-)), azelate ((-)OOC(CH2)7COO(-)), and benzoate (C6H5COO(-)) ions through ion exchange reactions. Solid state 13C nuclear magnetic resonance spectroscopy showed only one signal of carboxylic carbon for adipate and azelate intercalated into LDH, indicating that the carboxylic ends of both acids were equivalent, whereas the signal split when the intercalation was into the ZHN matrix. The electron paramagnetic resonance (EPR) spectrum of copper in octahedral cation sites of LDH layers showed a Hamiltonian parameter ratio g ||/A ||=170 cm and, after intercalation of adipate, the change was not significant: g ||/A ||=174 cm. This result indicates that the carboxylate ions did not coordinate with copper centers. Nonetheless, the intercalation of azelate increased the ratio to g ||/A ||=194 cm, similar to the spectra of ZHN modified with adipate, g ||/A ||=199 cm, and azelate, g ||/A ||=183 and 190 cm, which are associated with the coordination of copper by weak carboxylate anion ligands. Copper occupies octahedral or tetrahedral sites in ZHN layers, and the EPR spectra indicate that the dicarboxylate anions reacted preferentially with octahedral sites, whereas benzoate reacted with both sites.

  18. Structural, electrochemical characterization and SOD mimic activities of 1D chain or 3D network encouraged by unique μ2-bridging by adipate ion in mixed ligand complexes containing α-diimine as auxiliary ligand

    NASA Astrophysics Data System (ADS)

    Siddiqi, Zafar A.; Sharma, Prashant K.; Shahid, M.; Kumar, Sarvendra; Anjuli; Siddique, Armeen

    The present ternary complexes [Cu(ada)(phen)(H2O)]·2H2O (1), [Co2(ada)2(phen)2(H2O)2] (2) and [{Cu(ada)3(bipy)}n·3nH2O] (3) (H2ada = adipic acid, phen = 1,10-phenanthroline and bipy = 2,2'-bipyridine) obtained under varying experimental conditions were characterized by spectral, electrochemical and thermal studies. The bonding modes and the spatial arrangements of the carboxylate dianion around the metal ions have been investigated employing FTIR, EPR and X-ray crystallographic studies. Present data revealed a six coordinate distorted octahedral geometry for 2 with a = 8.068, b = 9.788, c = 11.788 Å, α = 70.464, β = 75.109, γ = 72.063° and a five coordinate square pyramidal geometry for 3 with a = 9.509, b = 9.912, c = 12.656 Å, α = 70.486, β = 73.604, γ = 75.162°. The superoxide dismutase (SOD) mimic activities of the complexes are in the order 1 > 3 > 2.

  19. Production and characterization of novel starch and poly(butylene adipate-co-terephthalate)-based materials and their applications

    NASA Astrophysics Data System (ADS)

    Stagner, Jacqueline Ann

    This work focuses on the production and characterization of blends of maleated thermoplastic starch (MTPS) and poly(butylenes adipate-co-terephthalate) and their application for use as thermoformed objects, films, and foams. First, by the production and characterization of maleated thermoplastic starch (MTPS) synthesized by reactive extrusion in a twin-screw extruder, a better understanding of MTPS was gained. This reactive thermoplastic starch was prepared with glycerol as the plasticizer, maleic anhydride (MA), and free-radical initiator, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (Luperox 101). Dynamic light scattering (DLS), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), soxhlet extraction in acetone, and environmental scanning electron microscopy (ESEM) were performed to determine the effect of maleation, extrusion temperature, initiator concentration, and maleic anhydride concentration on the resulting MTPS. Next, maleated thermoplastic starch (MTPS) and thermoplastic starch (TPS) were reactively blended in a twin-screw extruder with a biodegradable polyester, poly(butylene adipate-co-terephthalate) (PBAT). The blends were extruded to produce thermoformable sheets. The mechanical properties of the sheets were characterized by tensile and puncture tests. Proof of grafting was determined by soxhlet extraction in dichloromethane and FTIR analysis. Observations of the thermal properties were made using DSC, while the surface of the sheets was imaged using ESEM. Blends of MTPS and PBAT were also extruded to produce films. Mechanical testing (tensile and puncture tests) and barrier performance testing (carbon dioxide, oxygen, and water vapor permeability) were performed on the films. Transmission electron microscopy (TEM) was used to image the blends and to view the dispersion of the various phases. Finally, blends of MTPS and PBAT were extruded with an endothermic chemical blowing agent to produce foams. The foams were

  20. Testing and commercialization of byproduct dibasic acids as buffer additives for limestone flue gas desulfurization systems

    SciTech Connect

    Chang, J.C.S.; Mobley, J.D.

    1983-10-01

    Pilot plant (0.1 MW) tests and utility boiler full scale demonstration (194 MW) of byproduct organic dibasic acids (DBA) as buffer additives to limestone scrubbers have shown performance improvements equivalent to those achieved by the addition of pure adipic acid. Both SO/sub 2/ removal efficiency and limestone utilization increased, and no significant operating problems were observed with three of the four DBA tested. Chemical and biological evaluations of scrubber samples taken during the DBA testing indicated no detectable toxicity or mutagenicity, and no significant environmental impact is expected as a result of DBA addition. Economic estimates indicate that substitution of DBA for pure adipic acid as a buffer additive will result in additive cost savings of 30% or greater.

  1. Toughening of biodegradable polylactide/poly(butylene succinate-co-adipate) blends via in situ reactive compatibilization.

    PubMed

    Ojijo, Vincent; Ray, Suprakas Sinha; Sadiku, Rotimi

    2013-05-22

    Polylactide and poly(butylene succinate-co-adipate) (PLA/PBSA) were melt-blended in the presence of triphenyl phosphite (TPP). An increase in the torque during melt mixing was used to monitor the changes in viscosity as compatibilization of the blends occurred. Scanning electron micrographs showed not only a reduction in the dispersed-phase size with increased TPP content but also fibrillated links between the PLA and PBSA phases, signifying compatibilization. Moreover, optimization of parameters such as the mixing sequence and time, TPP content, and PBSA concentration revealed that blends containing 30 and 10 wt % PBSA and 2 wt % TPP, which were processed for 30 min, were optimal in terms of thermomechanical properties. The impact strength increased from 6 kJ/m(2) for PLA to 11 and 16 kJ/m(2) for blends containing 30 and 10 wt % PBSA, respectively, whereas the elongation-at-break increased from 6% for PLA to 20 and 37% for blends containing 30 and 10 wt % PBSA, respectively. Upon compatibilization, the failure mode shifted from the brittle fracture of PLA to ductile deformation, effected by the debonding between the two phases. With improved phase adhesion, compatibilized blends not only were toughened but also did not significantly lose tensile strength and thermal stability.

  2. In vitro dermal absorption of di(2-ethylhexyl) adipate (DEHA) in a roll-on deodorant using human skin.

    PubMed

    Zhou, Simon Ningsun; Moody, Richard P; Aikawa, Bio; Yip, Anna; Wang, Bing; Zhu, Jiping

    2013-01-01

    In vitro dermal absorption experiments were conducted using a roll-on deodorant that contains 1.56% di(2-ethylhexyl) adipate (DEHA), a plasticizer widely used in consumer products. Human skin specimens were fitted in Bronaugh flow-through Teflon diffusion cells. The diffusion cells were maintained at 32 °C to reflect the skin temperature. Two amounts (low dose: 5 mg of the product; high dose: 100 mg) were applied, in triplicate, each on four different human skins. DEHA was determined in the receiver solution at 6-h intervals, using headspace solid-phase microextraction gas chromatography-mass spectrometry (GC-MS). After 24 h, the experiment was terminated and masses of DEHA in the skin depot, skin wash, and upper and lower chambers of the diffusion cell were determined. A significant portion of applied DEHA, 28% in the low amount application and 34% in the high one, was found in the skin depot. In comparison, only 0.04% and 0.002% of applied DEHA were found in the receiver solutions for the low and high doses, respectively. Under our experimental conditions, an apparent steady-state flux of low DEHA mass penetrating from skin into the receiver solution was observed with a penetration rate of 2.2 ng/cm(2)/h for both the low and high doses. The average mass recovery was 81% for the low dose application and 56% for the high dose.

  3. Penetration and intracellular uptake of poly(glycerol-adipate) nanoparticles into three-dimensional brain tumour cell culture models.

    PubMed

    Meng, Weina; Garnett, Martin C; Walker, David A; Parker, Terence L

    2016-03-01

    Nanoparticle (NP) drug delivery systems may potentially enhance the efficacy of therapeutic agents. It is difficult to characterize many important properties of NPs in vivo and therefore attempts have been made to use realistic in vitro multicellular spheroids instead. In this paper, we have evaluated poly(glycerol-adipate) (PGA) NPs as a potential drug carrier for local brain cancer therapy. Various three-dimensional (3-D) cell culture models have been used to investigate the delivery properties of PGA NPs. Tumour cells in 3-D culture showed a much higher level of endocytic uptake of NPs than a mixed normal neonatal brain cell population. Differences in endocytic uptake of NPs in 2-D and 3-D models strongly suggest that it is very important to use in vitro 3-D cell culture models for evaluating this parameter. Tumour penetration of NPs is another important parameter which could be studied in 3-D cell models. The penetration of PGA NPs through 3-D cell culture varied between models, which will therefore require further study to develop useful and realistic in vitro models. Further use of 3-D cell culture models will be of benefit in the future development of new drug delivery systems, particularly for brain cancers which are more difficult to study in vivo.

  4. Evaluation of a predictive mathematical model of di-(2-ethylhexyl) adipate plasticizer migration from PVC film into foods.

    PubMed

    Mercer, A; Castle, L; Comyn, J; Gilbert, J

    1990-01-01

    The diffusion coefficient of the plasticizer di-(2-ethylhexyl)adipate (DEHA) in Cheddar cheese (Df) was determined by measuring the extent to which DEHA penetrated cheese that was placed in intimate contact with artificially DEHA-contaminated cheese. Slices (20 microns) of cheese from the boundary layer, into which DEHA had migrated, were microtomed at -40 degrees C, and analyzed for DEHA by gas chromatography (GC). Mean values of Df determined by graph fitting experimental and calculated data were 1.5 x 10(-9) cm2 s-1 at 5 degrees C and 3.0 x 10(-8) cm2 s-1 at 25 degrees C. The partition coefficient (K) of DEHA between cheese and PVC film was derived from the partition coefficients of DEHA between acetonitrile (ACN) and cheese lipid, ACN and cheese solid, and ACN and PVC film. The mean values of K between cheese and PVC film were estimated to be 0.70 at 5 degrees C and 0.58 at 25 degrees C. The estimated values of Df and K were then used in a mathematical model (Till et al. 1982) to predict migration levels of DEHA into cheese. Good agreement with previously published experimental data was obtained. Extrapolation of the prediction of DEHA migration into fatty foods, such as salami and avocado, was also successful (ratio of experimental to predicted results within a factor of two). The values of Df and K for cheese are, however, inappropriate for modelling non-fatty foods such as meat, cakes, fruit and vegetables. Predicted values for these foods were typically 3-10-fold too high. More accurate predictions would probably be obtained if values of Df more relevant to these foods are used. The predictions were relatively insensitive to the value of K.

  5. Comparative Studies on the Mechanical Properties of Nonwoven- and Woven-Flax-Fiber-Reinforced Poly(Butylene Adipate-Co-Terephthalate)-Based Composite Laminates

    NASA Astrophysics Data System (ADS)

    Phongam, N.; Dangtungee, R.; Siengchin, S.

    2015-03-01

    Textile biocomposites made from woven- and nonwoven-flax-fiber-reinforced poly(butylene adipate-co-terephthalate) (PBAT) were prepared by compression molding using the film stacking method, and their tensile strength and stiffness, flexural strength and modulus, and impact strength were determined experimentally. The PBAT-based composites were subjected to water absorption tests. The mechanical properties of pure PBAT and the textile composites were compared, and the influence of flax weave styles on the properties were evaluated. The biocomposite reinforced with 4 × 4-plain weave fibers showed the highest strength and stiffness compared with those of the other textile biocomposites and pure PBAT.

  6. [Synthesis and antituberculosis activity of the derivatives of glycoside steviolbioside from the plant Stevia rebaudiana and diterpenoid isosteviol containing hydrazone, hydrazide and pyridinoyl moieties].

    PubMed

    Kataev, V E; Strobykina, I Iu; Andreeva, O V; Garifullin, B F; Sharipova, R R; Mironov, V F; Chestnova, R V

    2011-01-01

    Conjugates of antitubercular drug Isoniazid (hydrazide of isonicotinic acid), nicotinic and alpha-picolinic acid hydrazides and glycoside steviolbioside from the plant Stevia rebaudiana as well as the product of its acid hydrolysis, diterpenoid isosteviol, were synthesized. Besides, isosteviol hydrazide and hydrazone derivatives as well as conjugates containing two isosteviol moieties connected by dihydrazide linker were also obtained. Both initial compounds and their synthetic derivatives inhibit the growth of Mycobacterium tuberculosis (H37Rv in vitro). The minimum concentration at which the growth of M. tuberculosis was inhibited by 100% (MIC) for stevioside and steviolbioside equals 7.5 and 3.8 microg/mL, respectively. MIC values for conjugates of the hydrazides of pyridine carbonic acids and steviolbioside as well as isosteviol are in the ranges 5-10 and 10-20 microg/mL, respectively. Maximum inhibitory effect against M. tuberculosis showed the conjugates of isosteviol and adipic acid dihydrazide (MIC values ranged from 1.7 to 3.1 microg/mL). Antitubercular activity of the compounds studied is higher than the activity of antitubercular drug Pyrizanamide (MIC = 12.5-20 microg/mL) but lower than the activity of antitubercular drug Isoniazid (MIC = 0.02-0.04 microg/mL).

  7. Homogeneous vs. heterogeneous nucleation in water-dicarboxylic acid systems

    NASA Astrophysics Data System (ADS)

    Hienola, A. I.; Vehkamäki, H.; Riipinen, I.; Kulmala, M.

    2009-03-01

    Binary heterogeneous nucleation of water-succinic/glutaric/malonic/adipic acid on nanometer-sized particles is investigated within the frame of classical heterogeneous nucleation theory. Homogeneous nucleation is also included for comparison. It is found that the nucleation probabilities depend on the contact angle and on the size of the seed particles. New thermodynamical properties, such as saturation vapor pressure, density and surface tension for all the dicarboxylic acid aqueous solutions are included in the calculations. While the new surface tension and density formulations do not bring any significant difference in the computed nucleation rate for homogeneous nucleation for succinic and glutaric acids, the use of the newly derived equations for the vapor pressure decrease the acid concentrations in gas phase by 3 orders of magnitude. According to our calculations, the binary heterogeneous nucleation of succinic acid-water and glutaric acid-water - although it requires a 3-4 orders of magnitude lower vapor concentrations than the homogeneous nucleation - cannot take place under atmospheric conditions. On the other hand binary homogeneous nucleation of adipic acid-water systems might be possible under conditions occuring in upper boundary layer. However, a more detailed characterization of the interaction between the surface and the molecules of the nucleating vapor should be considered in the future.

  8. Migration of di-(2-ethylhexylexyl)adipate plasticizer from food-grade polyvinyl chloride film into hard and soft cheeses.

    PubMed

    Goulas, A E; Anifantaki, K I; Kolioulis, D G; Kontominas, M G

    2000-08-01

    Food-grade polyvinyl chloride (PVC) film containing 28.3% di-(2-ethylhexylexyl)adipate (DEHA) plasticizer was used to wrap three different types of cheese (Kefalotyri, Edam, and Feta). Samples were split into two groups and stored at 5+/-0.5 degrees C. One group was analyzed for DEHA content at intervals between 1 and 240 h of contact (kinetic study), and a second group was cut into slices (1.2 mm thick) after 240 h of cheese/PVC contact and was analyzed for DEHA content (penetration study). The DEHA was determined by indirect gas chromatography. Statistically significant differences in migration of DEHA were observed between the cheese types. Migration of DEHA depended on contact time, fat, and moisture contents, and consistency of cheese samples. Equilibrium conditions were approached after approximately 100 h of contact for Edam and 150 h for Kefalotyri cheese. Equilibrium conditions were not reached for Feta cheese, even after 240 h of contact. After 240 h of contact under refrigeration, the migration of DEHA was approximately 345.4 mg/kg (18.9 mg/dm2) for Kefalotyri, 222.5 mg/kg (12.2 mg/dm2) for Edam, and 133.9 mg/kg (7.3 mg/dm2) for Feta. The loss of DEHA from the PVC film into the three cheese types was 37.8, 24.3, and 14.6%, respectively. These values, with the exception of Feta, were higher than the upper limit for global migration from plastic packaging materials into food and food stimulants set by the European Union (EU) (10 mg/dm2 or 60 mg/kg). After 240 h of cheese/film contact, DEHA was detected in the first three slices beneath the cheese surface (3.6 mm total depth) of Edam cheese and in the first two slices (2.4 mm total depth) of Kefalotryi and Feta cheeses. DEHA was not detected in subsequent layers. The effect of cheese rind on migration of DEHA was studied in Edam and Kefalotyri cheeses. The DEHA migration after 240 h into the first 1 mm beneath the surface of Kefalotyri cheese was 22.4 mg/kg, while DEHA was not detected in Edam cheese.

  9. Specific migration of di-(2-ethylhexyl)adipate (DEHA) from plasticized PVC film: results from an enforcement campaign.

    PubMed

    Petersen, J H; Breindahl, T

    1998-07-01

    A control campaign on the correct labelling of plasticized PVC film according to current legislation on food contact materials has been performed. Analytical methods based on the isotope dilution technique were developed. For enforcement purposes, the films were exposed to the official food simulant, olive oil, followed by clean-up using size exclusion chromatography and final determination of di-(2-ethylhexyl) adipate (DEHA) by combined capillary gas chromatography and mass spectrometry (GC-MS). In the initial screening, the samples were exposed to the alternative food simulant, isooctane, and DEHA could be determined by GC-MS without further clean-up. A good consistency between results from the two different methods was obtained. During the campaign, 49 samples of PVC films, the majority intended for use in retail shops, were sampled from importers and wholesalers by the Municipal Food Control Units. Initially, all films were screened for the migration into isooctane (exposed 2 h at 40 degrees C) of DEHA and other potentially present low molecular weight plasticizers using full scanning mass spectrometry. Films showing a substantial migration of DEHA were further tested with olive oil according to the declared field of application (exposed for 10 days at 40 degrees C). In 47 of the 49 films the migrate contained a substantial amount of DEHA. In 46 films the migration exceeded the specific migration limit of 3 mg/dm2 after use of the relevant reduction factor given in legislation. However, because of the general uncertainty of the analytical method and because the variation in the thickness of the films was calculated to be 1 mg/dm2, the action limit in this campaign was 4 mg/cm2. A migration higher than this action limit was found in 42 films (89% of the samples) and these films were deemed to be illegal according to their present declared field of application as given by their labelling. In a few cases, some migration of the plasticizer di-n-butyl phthalate was

  10. Measuring enthalpy of sublimation of volatiles by means of micro-thermogravimetry: the case of Dicarboxylic acids

    NASA Astrophysics Data System (ADS)

    Dirri, F.; Longobardo, A.; Palomba, E.; Zampetti, E.; Biondi, D.; Boccaccini, A.; Saggin, B.; Bearzotti, A.; Macagnano, A.

    2013-09-01

    VISTA (Volatile In Situ Thermogravimetry Analyser) is a thermogravimeter currently under study for the proposed mission MarcoPolo-R [1,2]. In the framework of this project, we developed a set-up to measure the enthalpy of sublimation ΔH of three dicarboxylic acids, i.e. adipic, succinic and oxalic. The obtained results are in good agreement with literature, and this demonstrates the capability of our device to perform this kind of measurements.

  11. Piezoelectric crystal microbalance measurements of enthalpy of sublimation of C2-C9 dicarboxylic acids

    NASA Astrophysics Data System (ADS)

    Dirri, F.; Palomba, E.; Longobardo, A.; Zampetti, E.

    2016-02-01

    We present here a novel experimental set-up that is able to measure the enthalpy of sublimation of a given compound by means of piezoelectric crystal microbalances (PCMs). The PCM sensors have already been used for space measurements, such as for the detection of organic and non-organic volatile species and refractory materials in planetary environments. In Earth atmospherics applications, PCMs can be also used to obtain some physical-chemical processes concerning the volatile organic compounds (VOCs) present in atmospheric environments. The experimental set-up has been developed and tested on dicarboxylic acids. In this work, a temperature-controlled effusion cell was used to sublimate VOC, creating a molecular flux that was collimated onto a cold PCM. The VOC recondensed onto the PCM quartz crystal, allowing the determination of the deposition rate. From the measurements of deposition rates, it has been possible to infer the enthalpy of sublimation of adipic acid, i.e. ΔHsub : 141.6 ± 0.8 kJ mol-1, succinic acid, i.e. 113.3 ± 1.3 kJ mol-1, oxalic acid, i.e. 62.5 ± 3.1 kJ mol-1, and azelaic acid, i.e. 124.2 ± 1.2 kJ mol-1. The results obtained show an accuracy of 1 % for succinic, adipic, and azelaic acid and within 5 % for oxalic acid and are in very good agreement with previous works (within 6 % for adipic, succinic, and oxalic acid and within 11 % or larger for azelaic acid).

  12. Pyridoxine-dependent seizures caused by alpha amino adipic semialdehyde dehydrogenase deficiency: the first polish case with confirmed biochemical and molecular pathology.

    PubMed

    Kaczorowska, Magdalena; Kmiec, Tomasz; Jakobs, Cornelis; Kacinski, Marek; Kroczka, Slawomir; Salomons, Gajja S; Struys, Eduard A; Jozwiak, Sergiusz

    2008-12-01

    Pyridoxine-dependent seizures are a rare condition recognized when numerous seizures respond to pyridoxine treatment and recur on pyridoxine withdrawal. For decades the diagnosis was confirmed only with pyridoxine treatment withdrawal trial. Recently described biochemical and molecular pathology improved the diagnostic process for those cases in which seizures are caused by alpha amino adipic semialdehyde dehydrogenase deficiency. This article presents a girl with recurrent status epilepticus episodes resistant to phenobarbital and phenytoin and partly responding to midazolam. Eventually the seizures were completely controlled with pyridoxine; however, due to the severe condition of this child when seizing, no trial of withdrawal has been performed. The diagnosis of pyridoxine-dependent seizures was confirmed with biochemical and molecular testing revealing elevated alpha-AASA excretion and the presence of 2 different mutations in the antiquitin ( ALDH7A1) gene. Due to the availability of reliable laboratory testing, confirmation of the diagnosis was made without the life-threatening trial of pyridoxine withdrawal.

  13. Binary blends of poly(butylene adipate-co-terephthalate) and poly(butylene succinate): A new matrix for biocomposites applications

    NASA Astrophysics Data System (ADS)

    Muthuraj, Rajendran; Misra, Manjusri; Mohanty, Amar Kumar

    2015-05-01

    In this study, biodegradable poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) binary blends were melt compounded. The mechanical, thermal and morphological properties of the PBAT/PBS blends were investigated. The melt compounded binary PBAT/PBS blends showed balanced mechanical properties (especially in tensile strength and elongation) compared to neat components. The obtained melt flow index (MFI) value of the blends is much higher than PBAT. This may be attributed to PBS phase residual catalyst that can induce thermal degradation of the polymers at higher temperature. The toughness of the PBAT is not significantly affected with addition of 40 wt% PBS in the PBAT/PBS blend. This could be the reason of good compatibility achieved between the PBAT and PBS phase in the blends. The phase morphology and spherulite morphology were also correlated with compatibility between the PBAT and PBS in the blends.

  14. Use of fluorescein hydrazide and fluorescein thiosemicarbazide reagents for the fluorometric determination of protein carbonyl groups and for the detection of oxidized protein on polyacrylamide gels.

    PubMed

    Ahn, B; Rhee, S G; Stadtman, E R

    1987-03-01

    Highly fluorescent thiosemicarbazide and hydrazide prepared by reaction of fluorescein isothiocyanate with hydrazine or adipic acid dihydrazide have been used to monitor the presence of carbonyl groups in oxidatively modified proteins. After oxidation, proteins react with these reagents under anaerobic conditions in the dark to yield fluorescent protein conjugates (presumably thiosemicarbazones or hydrazones) which can be visualized as fluorescent bands following electrophoresis (0-4 degrees C) on lithium dodecyl sulfate-polyacrylamide gels. These reagents do not react with unoxidized proteins. The conjugates formed dissociate readily at room temperature but are fairly stable at pH 6-9, 0 degrees C. Current data suggest that these reagents will be useful in the detection and quantitation of oxidatively modified proteins in biological systems.

  15. Enzymic oxidation of monoclonal antibodies by soluble and immobilized bifunctional enzyme complexes.

    PubMed

    Solomon, B; Koppel, R; Schwartz, F; Fleminger, G

    1990-06-27

    Site-specific modification of monoclonal antibodies was achieved by oxidation of the carbohydrate moieties of antibodies which are located remote from the antigen binding sites. Sialic acid and galactose are terminal sugars of these carbohydrate chains. Concomitant treatment of the antibodies with neuraminidase and galactose oxidase generated aldehyde groups in the oligosaccharide moieties of immunoglobulins which reacted selectively with amino or hydrazide groups of the matrix. Subsequent immobilization of neuraminidase and galactose oxidase on Eupergit C-adipic dihydrazide proved to be an efficient and selective system for the enzymic oxidation of the monoclonal antibodies without impairing their immunological activity. Oriented immobilization of enzymically oxidized monoclonal antibodies on hydrazide or amino Eupergit C derivatives thus leads to the formation of antibody matrix conjugates which possess high antigen-binding activities.

  16. New energetic epoxy binders

    SciTech Connect

    Jain, S.R.; Amanulla, S.

    1996-07-01

    A new class of epoxy resins having N{single_bond}N bonds in the backbone has been synthesized with a view to explore their properties as energetic binders. The N-epoxidation of bis-dicarbonylhydrazones of adipic, azelaic and sebacic dihydrazides results in the formation of viscous resins having epoxide end groups. The resins have been characterized by the elemental and end group analyses, IR and NMR spectra. Relevant properties for their use as binders in solid propellants, such as thermal stability, heat of combustion, burn rate and performance parameters of AP-based propellant systems, have been evaluated. A significant increase in the burn rate of AP-based propellants noticed, is perhaps related to the exothermicity of the binder decomposition and the reactivity of N{single_bond}N bonds with perchloric acid formed during the combustion of AP.

  17. Type IV resistant starch increases cecum short chain fatty acids level in rats.

    PubMed

    Le Thanh-Blicharz, Joanna; Anioła, Jacek; Kowalczewski, Przemysław; Przygoński, Krzysztof; Zaborowska, Zofia; Lewandowicz, Grażyna

    2014-01-01

    Resistant starches are type of dietary fibers. However, their physiological effects depend on the way they resist digestion in the gastrointestinal tract. The objective of this study was to examine the hypothesis that new type of RS4 preparations, of in vitro digestibility of about 50%, obtained by cross-linking and acetylation, acts as a prebiotic by increasing short chain fatty acids content in cecum digesta. The rats were fed with diet containing pregelatinized, cross-linked and acetylated starches as a main carbohydrate source. Pregelatinized, but not chemically modified, potato starch was used in the composition of the control diet. After two weeks of experiment the increase of short chain fatty acids contents in ceceum digesta was observed. The intake of starch A, cross-linked only with adipic acid, resulted in increase of about 40% of short chain fatty acids content, whereas starch PA cross-linked with sodium trimetaphosphate and adipic acid of about 50%. The utmost twofold increase was observed in the case of the production of propionic acid. In contrast, the content of butyric acid increased (12%) only as an effect of consumption of starch PA and even decreased (about 30%) in case of starch A. Both RS4 starches caused an increase of the production of acetic acid by more than 40%. No changes in serum biochemistry, liver cholesterol and organ weights of rats were stated.

  18. Water-enhanced solubility of carboxylic acids in organic solvents and its applications to extraction processes

    SciTech Connect

    Starr, J.N.; King, C.J.

    1991-11-01

    The solubilities of carboxylic acids in certain organic solvents increase remarkably with an increasing amount of water in the organic phase. This phenomenon leads to a novel extract regeneration process in which the co-extracted water is selectively removed from an extract, and the carboxylic acid precipitates. This approach is potentially advantageous compared to other regeneration processes because it removes a minor component of the extract in order to achieve a large recovery of acid from the extract. Carboxylic acids of interest include adipic acid, fumaric acid, and succinic acid because of their low to moderate solubilities in organic solvents. Solvents were screened for an increase in acid solubility with increased water concentration in the organic phase. Most Lewis-base solvents were found to exhibit this increased solubility phenomena. Solvents that have a carbonyl functional group showed a very large increase in acid solubility. 71 refs., 52 figs., 38 tabs.

  19. Heterogeneous Reaction of HO2 Radical with Dicarboxylic Acid Particles

    NASA Astrophysics Data System (ADS)

    Taketani, F.; Kanaya, Y.

    2010-12-01

    HOx(OH+ HO2) radical plays a central role in the tropospheric chemistry. Recently, the heterogeneous loss of HO2 by aerosol particles is a potentially important HOx sink in the troposphere suggested from observation study. However, there have been few studies for loss of HO2 by aerosols. In this study, we measured the HO2 uptake coefficients for four dicarboxylic acids (succinic acid, glutaric acid, adipic acid, and pimelic acid) aerosol particles under ambient conditions (760Torr and 296K) using an aerosol flow tube(AFT) coupled with a chemical conversion /laser-induced fluorescence(CC/LIF) technique. The CC/LIF technique enabled experiments to be performed at almost the same HO2 radical concentration as that in the atmosphere(-10^8 molecules/cm^3). In this system, the effect of the self-reaction of HO2 in the gas phase can be neglected. HO2 radicals were injected into the AFT through a vertically movable Pyrex tube. Injector position dependent profiles of LIF intensity were measured as a function of aerosol concentration at 30% and 70% of relative humilities (RH). Determined HO2 uptake coefficients by succinic acid, glutaric acid, adipic acid, and pimelic acid aerosol particles at 30% RH were 0.05 +/- 0.02, 0.07 +/- 0.03, 0.02 +/- 0.01, and 0.06 +/- 0.03, respectively, while the uptake coefficients by those particles at 70% RH were 0.13 +/- 0.05, 0.13 +/- 0.03, 0.06 +/- 0.01, and 0.11 +/- 0.03, respectively. These results suggest that compositions and relative humidity are significant to the HO2 uptake. We will discuss the potential HO2 loss processes.

  20. Oxidative cleavage with hydrogen peroxide: preparation of polycarboxylic acids from cyclic olefins.

    PubMed

    Fujitani, Kango; Mizutani, Toshihiro; Oida, Tatsuo; Kawase, Tokuzo

    2009-01-01

    Oxidative cleavage of carbon-carbon double bonds of cyclic olefins with hydrogen peroxide in the presence of heteropolyacids has been investigated as a clean and environmentally friendly preparation of polycarboxylic acids. In the presence of 12-tungstophospholic acid (H(3)PW(12)O(40)), adipic acid was obtained in 95% yield from cyclohexene in lipophilic phase and hydrogen peroxide in aqueous phase. In addition, 1,2,3,4-butanetetracarboxylic acid was also obtained in 87% yield from 1,2,3,6-tetrahydrophtharic acid anhydride, while endic acid anhydride did not afford corresponding 2,3,6-cyclopentanetetracarboxylic acid but only lactone compound was obtained. In this oxidation process, oxidative cleavage of carbon-carbon double bonds would proceed as the sequential reactions in which the rate determining step is oxidative cleavage of vicinal-diol compounds.

  1. Anaerobic Fermentation for Production of Carboxylic Acids as Bulk Chemicals from Renewable Biomass.

    PubMed

    Wang, Jufang; Lin, Meng; Xu, Mengmeng; Yang, Shang-Tian

    Biomass represents an abundant carbon-neutral renewable resource which can be converted to bulk chemicals to replace petrochemicals. Carboxylic acids have wide applications in the chemical, food, and pharmaceutical industries. This chapter provides an overview of recent advances and challenges in the industrial production of various types of carboxylic acids, including short-chain fatty acids (acetic, propionic, butyric), hydroxy acids (lactic, 3-hydroxypropionic), dicarboxylic acids (succinic, malic, fumaric, itaconic, adipic, muconic, glucaric), and others (acrylic, citric, gluconic, pyruvic) by anaerobic fermentation. For economic production of these carboxylic acids as bulk chemicals, the fermentation process must have a sufficiently high product titer, productivity and yield, and low impurity acid byproducts to compete with their petrochemical counterparts. System metabolic engineering offers the tools needed to develop novel strains that can meet these process requirements for converting biomass feedstock to the desirable product.

  2. Role of specific interfacial area in controlling properties of immiscible blends of biodegradable polylactide and poly[(butylene succinate)-co-adipate].

    PubMed

    Ojijo, Vincent; Sinha Ray, Suprakas; Sadiku, Rotimi

    2012-12-01

    Binary blends of two biodegradable polymers: polylactide (PLA), which has high modulus and strength but is brittle, and poly[(butylene succinate)-co-adipate] (PBSA), which is flexible and tough, were prepared through batch melt mixing. The PLA/PBSA compositions were 100/0, 90/10, 70/30, 60/40, 50/50, 40/60, 30/70, 10/90, and 0/100. Fourier-transform infrared measurements revealed the absence of any chemical interaction between the two polymers, resulting in a phase-separated morphology as shown by scanning electron microscopy (SEM). SEM micrographs showed that PLA-rich blends had smaller droplet sizes when compared to the PBSA-rich blends, which got smaller with the reduction in PBSA content due to the differences in their melt viscosities. The interfacial area of PBSA droplets per unit volume of the blend reached a maximum in the 70PLA/30PBSA blend. Thermal stability and mechanical properties were not only affected by the composition of the blend, but also by the interfacial area between the two polymers. Through differential scanning calorimetry, it was shown that molten PBSA enhanced crystallization of PLA while the stiff PLA hindered cold crystallization of PBSA. Optimal synergies of properties between the two polymers were found in the 70PLA/30PBSA blend because of the maximum specific interfacial area of the PBSA droplets.

  3. Effect of nanoclay loading on the thermal and mechanical properties of biodegradable polylactide/poly[(butylene succinate)-co-adipate] blend composites.

    PubMed

    Ojijo, Vincent; Sinha Ray, Suprakas; Sadiku, Rotimi

    2012-05-01

    Polylactide/poly[(butylene succinate)-co-adipate] (PLA/PBSA)-organoclay composites were prepared via melt compounding in a batch mixer. The weight ratio of PLA to PBSA was kept at 70:30, while the weight fraction of the organoclay was varied from 0 to 9%. Small angle X-ray scattering patterns showed slightly better dispersion in PBSA than PLA, and there was a tendency of the silicate layers to delaminate in PBSA at low clay content. Thermal analysis revealed that crystallinity was dependent on the clay content as well its localization within the composite. On the other hand, thermal stability marginally improved for composites with <2 wt % clay content in contrast to the deterioration observed in composites with clay content >2 wt %. Tensile properties showed dependence on clay content and localization. Composite with 2 wt % clay content showed slight improvement in elongation at break. Overall, the optimum property was found for a composite with 2 wt % of the organoclay. This paper therefore has demonstrated the significance of the clay content and localization on the properties of the PLA/PBSA blends.

  4. Investigation on sodium benzoate release from poly(butylene adipate-co-terephthalate)/organoclay/sodium benzoate based nanocomposite film and their antimicrobial activity.

    PubMed

    Mondal, Dibyendu; Bhowmick, Biplab; Maity, Dipanwita; Mollick, Md Masud R; Rana, Dipak; Rangarajan, Vivek; Sen, Ramkrishna; Chattopadhyay, Dipankar

    2015-03-01

    Polymeric nanocomposites embedded with nontoxic antimicrobial agents have recently gained potential industrial significance, mainly for their applicability to preserve food quality and ensure safety. In this study, a poly(butylene adipate-co-terephthalate) (PBAT)/organoclay (CMMT) based nanocomposite film doped with sodium benzoate (SB) as antimicrobial agent was prepared by a solution mixing process. A homogenous dispersion of organoclay (cetyltrimethylammonium-modified montmorillonite [CMMT]) in PBAT matrix was observed by X-ray diffraction and transmission electron microscopy. PBAT/CMMT nanocomposite film showed higher barrier properties against water and methanol vapor compared to the PBAT film. The release of SB from PBAT and its nanocomposite film was measured and the relevant data were fitted to the Weibull model. The higher values of Weibull's shape factor and scale parameter as corroborated by experimental findings indicated faster rate of SB release from PBAT/CMMT/SB nanocomposite film, when compared to the pristine PBAT film. Bacterial inhibition studies were accomplished against 2 food pathogenic bacteria, Bacillus subtilis and Staphylococcus aureus, by determining the zone of inhibition and corresponding growth profiles. Both bacterial inhibition studies and growth profiles established that PBAT/CMMT/SB demonstrated better antimicrobial activity than PBAT/SB film. Therefore, PBAT/CMMT/SB nanocomposite film can be used for food packaging application as it showed good barrier properties and antimicrobial activity against food pathogenic bacteria.

  5. Biomimetic Approach to Enhance Enzymatic Hydrolysis of the Synthetic Polyester Poly(1,4-butylene adipate): Fusing Binding Modules to Esterases.

    PubMed

    Perz, Veronika; Zumstein, Michael Thomas; Sander, Michael; Zitzenbacher, Sabine; Ribitsch, Doris; Guebitz, Georg M

    2015-12-14

    Mimicking a concept of nature for the hydrolysis of biopolymers, the Thermobifida cellulosilytica cutinase 1 (Thc_Cut1) was fused to a polymer binding module (PBM) to enhance the hydrolysis of the polyester poly(1,4-butylene adipate) (PBA). Namely, the binding module of a polyhydroxyalkanoate depolymerase from Alcaligenes faecalis (Thc_Cut1_PBM) was attached to the cutinase via two different linker sequences varying in length. In order to investigate the adsorption behavior, catalytically inactive mutants both of Thc_Cut1 and Thc_Cut1_PBM were successfully constructed by site-directed mutagenesis of serine 131 to alanine. Quartz crystal microbalance with dissipation monitoring (QCM-D) analysis revealed that the initial mass increase during enzyme adsorption was larger for the inactive enzymes linked with the PBM as compared to the enzyme without the PBM. The hydrolysis rates of PBA were significantly enhanced when incubated with the active, engineered Thc_Cut1_PBM as compared to the native Thc_Cut1. Thc_Cut1_PBM completely hydrolyzed PBA thin films on QCM-D sensors within approximately 40 min, whereas twice as much time was required for the complete hydrolysis by the native Thc_Cut1.

  6. Effect of Chain-Extenders on the Properties and Hydrolytic Degradation Behavior of the Poly(lactide)/Poly(butylene adipate-co-terephthalate) Blends

    PubMed Central

    Dong, Weifu; Zou, Benshu; Yan, Yangyang; Ma, Piming; Chen, Mingqing

    2013-01-01

    Biodegradable poly(lactide)/poly(butylene adipate-co-terephthalate) (PLA/PBAT) blends were prepared by reactive blending in the presence of chain-extenders. Two chain-extenders with multi-epoxy groups were studied. The effect of chain-extenders on the morphology, mechanical properties, thermal behavior, and hydrolytic degradation of the blends was investigated. The compatibility between the PLA and PBAT was significantly improved by in situ formation of PLA-co-PBAT copolymers in the presence of the chain-extenders, results in an enhanced ductility of the blends, e.g., the elongation at break was increased to 500% without any decrease in the tensile strength. The differential scanning calorimeter (DSC) results reveal that cold crystallization of PLA was enhanced due to heterogeneous nucleation effect of the in situ compatibilized PBAT domains. As known before, PLA is sensitive to hydrolysis and in the presence of PBAT and the chain-extenders, the hydrolytic degradation of the blend was evident. A three-stage hydrolysis mechanism for the system is proposed based on a study of weight loss and molecular weight reduction of the samples and the pH variation of the degradation medium. PMID:24152436

  7. Structure-barrier property relationship of biodegradable poly(butylene succinate) and poly[(butylene succinate)-co-(butylene adipate)] nanocomposites: influence of the rigid amorphous fraction.

    PubMed

    Charlon, S; Marais, S; Dargent, E; Soulestin, J; Sclavons, M; Follain, N

    2015-11-28

    Composites composed of polyesters, poly(butylene succinate) (PBS) or poly[(butylene succinate)-co-(butylene adipate)] (PBSA), and 5 wt% of montmorillonite (CNa) or organo-modified montmorillonite (C30B) were melt-processed and transformed into films by either compression-molding or extrusion-calendering. XRD, rheological measurements and TEM images clearly indicated that films containing CNa are microcomposites, while nanocomposites were observed for those containing C30B. Using Flash DSC, it was possible, for the first time, not only to measure the heat capacity step at the glass transition of these two materials in their amorphous state, but also to investigate whether the preparation technique influenced the Rigid Amorphous Fraction (RAF) in our PBS- and PBSA-based nanocomposites. In this work, we have successfully shown the correlation between the microstructure of the films and their barrier properties, and especially the role played by the RAF. Indeed, the lowest permeabilities to gases and to water were determined in the films containing the highest RAF in both PBS- and PBSA-based materials.

  8. Performance of AA5052 alloy anode in alkaline ethylene glycol electrolyte with dicarboxylic acids additives for aluminium-air batteries

    NASA Astrophysics Data System (ADS)

    Wang, DaPeng; Zhang, DaQuan; Lee, KangYong; Gao, LiXin

    2015-11-01

    Dicarboxylic acid compounds, i.e. succinic acid (SUA), adipic acid (ADA) and sebacic acid (SEA), are used as electrolyte additives in the alkaline ethylene glycol solution for AA5052 aluminium-air batteries. It shows that the addition of dicarboxylic acids lowers the hydrogen gas evolution rate of commercial AA5052 aluminium alloy anode. AA5052 aluminium alloy has wide potential window for electrochemical activity and better discharge performance in alkaline ethylene glycol solution containing dicarboxylic acid additives. ADA has the best inhibition effect for the self-corrosion of AA5052 anode among the three dicarboxylic acid additives. Fourier transform infrared spectroscopy (FT-IR) reveals that dicarboxylic acids and aluminium ions can form coordination complexes. Quantum chemical calculations shows that ADA has a smaller energy gap (ΔE, the energy difference between the lowest unoccupied orbital and the highest occupied orbital), indicating that ADA has the strongest interaction with aluminium ions.

  9. Effect of dicarboxylic acid chain length on the self-cleaning property of Nano-TiO2-coated cotton fabrics.

    PubMed

    Khajavi, Ramin; Berendjchi, Amirhosein

    2014-11-12

    In this study, the effect of dicarboxylic acid chain length on the amount of TiO2 nanoparticles (TiO2NPs) adsorption-produced self-cleaning property and washing durability on cotton fabrics were investigated. First, cotton fabric samples were treated with three kinds of dicarboxylic acids--oxalic, succinic, and adipic acids--and then dipped in TiO2NP solution with a certain concentration. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) was used to investigate bonds formation between dicarboxylic acid groups and hydroxyl groups of cellulose, and a scanning electron microscope (SEM) was applied for the analysis of surface morphology in specimens. Drop absorbency time was determined for samples using the AATCC TM 79:2000. Washing stability and the amount absorption of TiO2NPs were determined by weighing and absorption spectrophotometry procedures, and the stain removal evaluation was conducted to assess the self-cleaning property. Results showed that all of the dicarboxylic acids used in this experiment improved the amount of TiO2NPs absorbed onto cotton samples and their durability to washing. In addition, color variation of samples treated with oxalic acid after 180 min of UV irradiation and drop absorbency time for samples treated with succinic acid were significantly increased by about 126 and 600%, respectively. The best durability was obtained from adipic acid, while a better self-cleaning property was obtained from oxalic acid.

  10. Preparation, characterization, and immunological properties in mice of Escherichia coli O157 O-specific polysaccharide-protein conjugate vaccines.

    PubMed Central

    Konadu, E; Robbins, J B; Shiloach, J; Bryla, D A; Szu, S C

    1994-01-01

    Escherichia coli O157 causes severe enteritis and the extraintestinal complication of hemolytic-uremic syndrome, with their highest incidence occurring in children. We postulated that serum immunoglobulin G (IgG) antibodies to the O-specific polysaccharide of lipopolysaccharide (LPS) may confer protective immunity to enteric pathogens by inducing bactericidal reactions against the ingested organisms in the jejunum (J. B. Robbins, C. Chu, and R. Schneerson, Clin. Infect. Dis. 15:346-361, 1992; S. C. Szu, R. Gupta, and J. B. Robbins, p. 381-394, in I. K. Wachsmuth, P. A. Blake, and O. Olsvik, ed., Vibrio cholerae, 1994). Because polysaccharide-protein conjugates induce serum IgG antibodies in infants, we bound the O-specific polysaccharide of E. coli O157 to proteins. E. coli O157 LPS, treated with acetic acid or hydrazine, was derivatized with adipic acid dihydrazide and bound to proteins by carbodiimide-mediated condensation. Conjugates of these adipic hydrazide derivative were prepared with bovine serum albumin, formalin-treated exotoxin C of Clostridium welchii (Pig Bel toxoid), or Pseudomonas aeruginosa recombinant exoprotein A. The conjugates had low levels of endotoxin and elicited serum antibodies with bactericidal activity to the O157 LPS. The largest increase in LPS antibodies was of the IgG class. Clinical evaluation of E. coli O157-toxoid conjugates is planned. Images PMID:7927787

  11. Molecular structures and hydrogen bonding in the crystalline hydrates of two flexible double betaines with different quaternary ammonio groups in the adipic acid skeleton

    NASA Astrophysics Data System (ADS)

    Wu, De-Dong; Mak, Thomas C. W.

    1995-12-01

    Crystalline dihydrates of two flexible double betaines -O 2CCH(R)CH 2CH 2CH(R)CO -2 ( 1, R = Me 3N +, 2, R = C 5H 5N +) have been characterized by single-crystal X-ray analysis. Both compounds crystallize in the monoclinic space group {P2 1}/{c} with a = 7.463(4), b = 10.312(6), c = 9.978(5) Å, β = 90.18(5)°, Z = 2 for 1·2H 2O and a = 9.063(2), b = 7.665(1), c = 11.962(1) Å, β = 94.89(1)°, Z = 2 for 2·2H 2O. Both betaine molecules occupy l¯ sites but differ with regard to the orientation of the carboxylate groups and ammonio groups. In each crystal structure, the formation of donor hydrogen bonds from the water molecules to adjacent carboxylate groups gives rise to an infinte two-dimensional network composed of a packing of identical 26-membered rings.

  12. Enhancement of mechanical and thermal properties of oil palm empty fruit bunch fiber poly(butylene adipate-co-terephtalate) biocomposites by matrix esterification using succinic anhydride.

    PubMed

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Bin Wan; Rahman, Mohamad Zaki Ab

    2012-02-16

    In this work, the oil palm empty fruit bunch (EFB) fiber was used as a source of lignocellulosic filler to fabricate a novel type of cost effective biodegradable composite, based on the aliphatic aromatic co-polyester poly(butylene adipate-co-terephtalate) PBAT (Ecoflex™), as a fully biodegradable thermoplastic polymer matrix. The aim of this research was to improve the new biocomposites' performance by chemical modification using succinic anhydride (SAH) as a coupling agent in the presence and absence of dicumyl peroxide (DCP) and benzoyl peroxide (BPO) as initiators. For the composite preparation, several blends were prepared with varying ratios of filler and matrix using the melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 (wt %) and characterized. The effects of fiber loading and coupling agent loading on the thermal properties of biodegradable polymer composites were evaluated using thermal gravimetric analysis (TGA). Scanning Electron Microscopy (SEM) was used for morphological studies. The chemical structure of the new biocomposites was also analyzed using the Fourier Transform Infrared (FTIR) spectroscopy technique. The PBAT biocomposite reinforced with 40 (wt %) of EFB fiber showed the best mechanical properties compared to the other PBAT/EFB fiber biocomposites. Biocomposite treatment with 4 (wt %) succinic anhydride (SAH) and 1 (wt %) dicumyl peroxide (DCP) improved both tensile and flexural strength as well as tensile and flexural modulus. The FTIR analyses proved the mechanical test results by presenting the evidence of successful esterification using SAH/DCP in the biocomposites' spectra. The SEM micrograph of the tensile fractured surfaces showed the improvement of fiber-matrix adhesion after using SAH. The TGA results showed that chemical modification using SAH/DCP improved the thermal stability of the PBAT/EFB biocomposite.

  13. Effect of fiber esterification on fundamental properties of oil palm empty fruit bunch fiber/poly(butylene adipate-co-terephthalate) biocomposites.

    PubMed

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Wan; Rahman, Mohamad Zaki Ab

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG) after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP) initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24%) compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA)/differential thermogravimetric (DTG) thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites' thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens.

  14. Migration of di(2-ethylhexyl) adipate and acetyltributyl citrate plasticizers from food-grade PVC film into sweetened sesame paste (halawa tehineh): kinetic and penetration study.

    PubMed

    Goulas, Antonios E; Zygoura, Panagiota; Karatapanis, Andreas; Georgantelis, Dimitris; Kontominas, Michael G

    2007-04-01

    Food-grade polyvinyl chloride (PVC) cling-film containing 5.3% (w/w) di(2-ethylhexyl) adipate (DEHA) and 3.0% (w/w) acetyltributyl citrate (ATBC) plasticizers was used to wrap halawa tehineh (halva) samples. Samples were split into two groups and stored at 25+/-1 degrees C. One group was analyzed for DEHA and ATBC content at intervals between 0.5 and 240h of contact (kinetic study) and a second group was cut into slices (1.5mm thick) after 240h of halva/PVC contact and was analyzed for DEHA and ATBC content (penetration study). Determination of both plasticizers was performed using a direct gas chromatographic (GC) method after extraction of DEHA from halva samples. DEHA readily migrated into halva samples: the equilibrium amount of DEHA in halva (3.31mg/dm(2) film or 81.4mg/kg halva) corresponding to a loss of 54.7% (w/w) DEHA from PVC film. This value is slightly higher than the limit of 3mg/dm(2) of film surface set by the European Union for DEHA. The equilibrium amount of ATBC in halva was 1.46mg/dm(2) (36.1mg/kg) corresponding to a loss of 42.7% ATBC from PVC film. With regard to the penetration of both placticizers into halva samples, migration of DEHA was detectable up to the 7th slice beneath the surface of halva (total depth 10.5mm) while the migration of ATBC was detectable up to the 5th slice (total depth 7.5mm).

  15. Effect of Fiber Esterification on Fundamental Properties of Oil Palm Empty Fruit Bunch Fiber/Poly(butylene adipate-co-terephthalate) Biocomposites

    PubMed Central

    Siyamak, Samira; Ibrahim, Nor Azowa; Abdolmohammadi, Sanaz; Yunus, Wan Md Zin Wan; Rahman, Mohamad Zaki AB

    2012-01-01

    A new class of biocomposites based on oil palm empty fruit bunch fiber and poly(butylene adipate-co-terephthalate) (PBAT), which is a biodegradable aliphatic aromatic co-polyester, were prepared using melt blending technique. The composites were prepared at various fiber contents of 10, 20, 30, 40 and 50 wt% and characterized. Chemical treatment of oil palm empty fruit bunch (EFB) fiber was successfully done by grafting succinic anhydride (SAH) onto the EFB fiber surface, and the modified fibers were obtained in two levels of grafting (low and high weight percentage gain, WPG) after 5 and 6 h of grafting. The FTIR characterization showed evidence of successful fiber esterification. The results showed that 40 wt% of fiber loading improved the tensile properties of the biocomposite. The effects of EFB fiber chemical treatments and various organic initiators content on mechanical and thermal properties and water absorption of PBAT/EFB 60/40 wt% biocomposites were also examined. The SAH-g-EFB fiber at low WPG in presence of 1 wt% of dicumyl peroxide (DCP) initiator was found to significantly enhance the tensile and flexural properties as well as water resistance of biocomposite (up to 24%) compared with those of untreated fiber reinforced composites. The thermal behavior of the composites was evaluated from thermogravimetric analysis (TGA)/differential thermogravimetric (DTG) thermograms. It was observed that, the chemical treatment has marginally improved the biocomposites’ thermal stability in presence of 1 wt% of dicumyl peroxide at the low WPG level of grafting. The improved fiber-matrix surface enhancement in the chemically treated biocomposite was confirmed by SEM analysis of the tensile fractured specimens. PMID:22408394

  16. 40 CFR 98.56 - Data reporting requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.56 Data reporting requirements. In... emissions from adipic acid production (metric tons). (b) Annual adipic acid production (tons). (c) Annual adipic acid production during which N2O abatement technology (located after the test point) is...

  17. 40 CFR 98.56 - Data reporting requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.56 Data reporting requirements. In... emissions from adipic acid production (metric tons). (b) Annual adipic acid production (tons). (c) Annual adipic acid production during which N2O abatement technology (located after the test point) is...

  18. Microbial production of specialty organic acids from renewable and waste materials.

    PubMed

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2015-01-01

    Microbial production of organic acids has become a fast-moving field due to the increasing role of these compounds as platform chemicals. In recent years, the portfolio of specialty fermentation-derived carboxylic acids has increased considerably, including the production of glyceric, glucaric, succinic, butyric, xylonic, fumaric, malic, itaconic, lactobionic, propionic and adipic acid through innovative fermentation strategies. This review summarizes recent trends in the use of novel microbial platforms as well as renewable and waste materials for efficient and cost-effective bio-based production of emerging high-value organic acids. Advances in the development of robust and efficient microbial bioprocesses for producing carboxylic acids from low-cost feedstocks are also discussed. The industrial market scenario is also reviewed, including the latest information on the stage of development for producing these emerging bio-products via large-scale fermentation.

  19. Synthesis and characterization of polyacids from palm acid oil and sunflower oil via addition reaction.

    PubMed

    Zeimaran, Ehsan; Kadir, Mohammed Rafiq Abdul; Nor, Hussin Mohd; Kamarul, Tunku; Djordjevic, Ivan

    2013-12-15

    In this study aliphatic polyacids were synthesized using palm acid oil (PAO) and sunflower oil (SFO) via addition reaction technique. The synthesized materials were characterized using Fourier-transform infra-red (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF-MS) and thermo-gravimetric analysis (TGA). Mixing formic acid and hydrogen peroxide with PAO or SFO at the ratio 3:10:1 produced the lowest iodine value of 10.57 and 9.24 respectively, indicating the increase in epoxidization of both oils. Adding adipic acid to the epoxidized oils at a ratio of 1:10 increases the acid values of SFO and PAO to 11.22 and 6.73 respectively. The existence of multi-acid groups present in synthesized polyacid was confirmed by MALD-ToF-MS. This feature indicates a possible value to the biomaterials development.

  20. Relationship between the effects on bacterial activity of selected disinfectants and the hydrophobic characters of dibasic acid diesters.

    PubMed

    Furuta, T; Kihara, K

    1992-05-01

    We prepared test solutions which contained 80% (v/v) ethanol and 0.2% (w/v) chlorhexidine (CH) or benzalkonium chloride (BC) with or without a dibasic acid diester. After complete evaporation of the ethanol from the solution on filter paper, an overnight broth culture (Staphylococcus aureus) was repeatedly inoculated onto the filter paper, and viable bacterial counts were measured at 5 min after the last inoculation. By comparison with viable counts for CH or BC alone, we estimated the potentiating effects of dibasic acid diester on the bactericidal activity of CH or BC, and confirmed that this activity of the two disinfectants was potentiated in the presence of certain compounds in the homologs of di-n-butyl esters of aliphatic dibasic acid, and di-alkyl esters of adipic and phthalic acid. Diisobutyl adipate, one of the most effective diesters, substantially enhanced the bactericidal activities of benzethonium chloride, cetyl pyridinium chloride and didecyl dimethyl ammonium chloride, as well as CH and BC, but not those of polyhexamethylene biguanide or alkyldiaminoethyl glycinate. The potentiating effects of dibasic acid diesters observed for both CH and BC seemed to be affected by the hydrophobic character of these diesters themselves and are also expressed well by a particular quadratic equation as a function of these characters: namely, capacity factors, as determined by high-performance liquid chromatography.

  1. A triclinic polymorph of hexa-nedioic acid.

    PubMed

    Fun, Hoong-Kun; Chantrapromma, Suchada

    2009-02-28

    Hexane-dioic acid (or adipic acid), C(6)H(10)O(4), crystallizes with two crystallographically independent half-mol-ecules in the asymmetric unit of the triclinic unit cell, space group P, as each mol-ecule lies across a crystallographic inversion centre. A monoclinic polymorph has been reported previously, most recently by Ranganathan, Kulkarni & Rao [J. Phys. Chem. A, (2003), 107, 6073-6081]. The mol-ecules adopt the expected zigzag structure and are linked via centrosymmetric pairs of O-H⋯O hydrogen bonds, forming infinite one-dimensional chains along [011]. These chains are stacked along the a axis. The crystal is further stabilized by weak C-H⋯O inter-actions.

  2. Study on dicarboxylic acids in aerosol samples with capillary electrophoresis.

    PubMed

    Adler, Heidi; Sirén, Heli

    2014-01-01

    The research was performed to study the simultaneous detection of a homologous series of α , ω -dicarboxylic acids (C2-C10), oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, and sebacic acids, with capillary electrophoresis using indirect UV detection. Good separation efficiency in 2,6-pyridinedicarboxylic acid as background electrolyte modified with myristyl trimethyl ammonium bromide was obtained. The dicarboxylic acids were ionised and separated within five minutes. For the study, authentic samples were collected onto dry cellulose membrane filters of a cascade impactor (12 stages) from outdoor spring aerosols in an urban area. Hot water and ultrasonication extraction methods were used to isolate the acids from membrane filters. Due to the low concentrations of acids in the aerosols, the extracts were concentrated with solid-phase extraction (SPE) before determination. The enrichment of the carboxylic acids was between 86 and 134% with sample pretreatment followed by 100-time increase by preparation of the sample to 50  μ L. Inaccuracy was optimised for all the sample processing steps. The aerosols contained dicarboxylic acids C2-C10. Then, mostly they contained C2, C5, and C10. Only one sample contained succinic acid. In the study, the concentrations of the acids in aerosols were lower than 10 ng/m(3).

  3. Water-enhanced solubility of carboxylic acids in organic solvents and its application to extraction processes

    SciTech Connect

    Starr, J.N. ); King, C.J. )

    1992-11-01

    This paper reports on solubilities of carboxylic acids in certain organic solvents which increase sharply as the concentration of water in the solvent increases. This phenomenon leads to a method of regeneration for solvent-extraction processes whereby coextracted water is selectively removed from the extract, such as by stripping, thereby precipitating the acid. The removal of a minor constituent to cause precipitation reduces energy consumption, in contrast with bulk removal of solvent. Solubilities of fumaric acid were measured in a number of organic solvents, with varying amounts of water in the organic phase. Cyclohexanone and methylcyclohexanone were chosen as solvents for which detailed solid-liquid and liquid-liquid equilibria were measured for adipic, fumaric, and succinic acids in the presence of varying concentrations of water, at both 25 and 45[degrees]C. Batch precipitation experiments were performed to demonstrate the processing concept and determine the relative volatility of water to solvent in the presence of carbon.

  4. Piezoelectric crystal microbalance measurements of enthalpy of sublimation of C2-C9 dicarboxylic acids

    NASA Astrophysics Data System (ADS)

    Dirri, F.; Palomba, E.; Longobardo, A.; Zampetti, E.

    2015-07-01

    We present here a novel experimental setup able to measure the enthalpy of sublimation of a given compound by means of Piezoelectric Crystal Microbalances (PCM). This experiment was performed in the TG-Lab facility in IAPS-INAF, dedicated to the development of TGA sensors for space measurements, such as detection of organic and non-organic volatile species and refractory materials in planetary environments. In order to study physical-chemical processes concerning the Volatile Organic Compounds (VOC) present in atmospheric environments, the setup has been tested on Dicarboxylic acids. Acids with low molecular weight are among the components of organic fraction of particulate matter in the atmosphere, coming from different sources (biogenic and anthropogenic). Considering their relative abundance, it is useful to consider Dicarboxylic acid as "markers" to define the biogenic or anthropogenic origin of the aerosol, thus obtaining some information of the emission sources. In this work, a temperature controlled effusion cell was used to sublimate VOC, creating a molecular flux that was collimated onto a cold PCM. The VOC re-condensed onto the PCM quartz crystal allowing the determination of the deposition rate. From the measurements of deposition rates, it was possible to infer the enthalpy of sublimation of Adipic acid, i.e. Δ Hsub: 141.6 ± 0.8 kJ mol-1, Succinic acid, i.e. 113.3 ± 1.3 kJ mol-1, Oxalic acid, i.e. 62.5 ± 3.1 kJ mol-1 and Azelaic acid, i.e. 124.2 ± 1.2 kJ mol-1 (weight average values). The results obtained are in very good agreement with literature within 10 % for the Adipic, Succinic and Oxalic acid.

  5. Adsorption of organic acids on TiO2 nanoparticles: effects of pH, nanoparticle size, and nanoparticle aggregation.

    PubMed

    Pettibone, John M; Cwiertny, David M; Scherer, Michelle; Grassian, Vicki H

    2008-06-01

    In this study, the adsorption of two organic acids, oxalic acid and adipic acid, on TiO2 nanoparticles was investigated at room temperature, 298 K. Solution-phase measurements were used to quantify the extent and reversibility of oxalic acid and adipic acid adsorption on anatase nanoparticles with primary particle sizes of 5 and 32 nm. At all pH values considered, there were minimal differences in measured Langmuir adsorption constants, K ads, or surface-area-normalized maximum adsorbate-surface coverages, Gamma max, between 5 and 32 nm particles. Although macroscopic differences in the reactivity of these organic acids as a function of nanoparticle size were not observed, ATR-FTIR spectroscopy showed some distinct differences in the absorption bands present for oxalic acid adsorbed on 5 nm particles compared to 32 nm particles, suggesting different adsorption sites or a different distribution of adsorption sites for oxalic acid on the 5 nm particles. These results illustrate that molecular-level differences in nanoparticle reactivity can still exist even when macroscopic differences are not observed from solution phase measurements. Our results also allowed the impact of nanoparticle aggregation on acid uptake to be assessed. It is clear that particle aggregation occurs at all pH values and that organic acids can destabilize nanoparticle suspensions. Furthermore, 5 nm particles can form larger aggregates compared to 32 nm particles under the same conditions of pH and solid concentrations. The relative reactivity of 5 and 32 nm particles as determined from Langmuir adsorption parameters did not appear to vary greatly despite differences that occur in nanoparticle aggregation for these two different size nanoparticles. Although this potentially suggests that aggregation does not impact organic acid uptake on anatase particles, these data clearly show that challenges remain in assessing the available surface area for adsorption in nanoparticle aqueous suspensions

  6. Synthesis and biological evaluation of some substituted-2-N-(5-chloro-2-methoxy-4-methylphenylsulphonyl) glutamic acid derivatives against prostate cancer cell line PC3.

    PubMed

    Hassan, Ghaneya Sayed; Abdel Rahman, Doaa Ezzat

    2013-01-01

    New series of substituted glutamine 5a-l and glutamic acid diamides, diureide and dihydrazide 7a-e were synthesized from parent glutamic acid compound 3 and evaluated for their cytotoxic activity against tumor cell line PC3 (prostate cancer cell line). Most of the tested compounds exploited potent growth inhibitory activity with IC(50) values ranging 0.034-3.97 µM. Particularly, compounds 5a, 3, 5j, 5b, 7c, 7e, 5l, and 5k exhibited superior potency (IC(50)=0.034, 0.04, 0.05, 0.074, 0.25, 0.4, 0.49, 0.522 µM, respectively) to the reference drug Doxorubicin (IC(50)=0.63 µM), while compound 7b showed IC(50), 0.71 µM, comparable to that of Doxorubicin. In summary, the newly synthesized compounds provided promising new lead for the future design and development of glutamine and glutamic acid derivatives as novel antitumor agents. The quantitative structure-activity relationship (QSAR) study was applied to find a mathematical correlation between the structures of compounds and their activity against PC3 cell line expressed as IC(50) values.

  7. [Compositions of organic acids in PM10 emission sources in Xiamen urban atmosphere].

    PubMed

    Yang, Bing-Yu; Huang, Xing-Xing; Zheng, An; Liu, Bi-Lian; Wu, Shui-Ping

    2013-01-01

    The possible organic acid emission sources in PM10 in Xiamen urban atmosphere such as cooking, biomass burning, vehicle exhaust and soil/dust were obtained using a re-suspension test chamber. A total of 15 organic acids including dicarboxylic acids, fatty acids and aromatic acids were determined using GC/MS after derivatization with BF3/n-butanol. The results showed that the highest total concentration of 15 organic acids (53%) was found in cooking emission and the average concentration of the sum of linoleic acid and oleic acid was 24% +/- 14%. However, oxalic acid was the most abundant species followed by phthalic acid in gasoline vehicle exhaust. The ratios of adipic to azelaic acid in gasoline combustion emissions were significantly higher than those in other emission sources, which can be used to qualitatively differentiate anthropogenic and biological source of dicarboxylic acids in atmospheric samples. The ratios of malonic to succinic acid in source emissions (except gasoline generator emissions) were lower (0.07-0.44) than ambient PM10 samples (0.61-3.93), which can be used to qualitatively differentiate the primary source and the secondary source of dicarboxylic acids in urban PM10.

  8. Episodic hypoglycemia with psi-hydroxy fatty acid excretion.

    PubMed

    Colle, E; Mamer, O A; Montgomery, J A; Miller, J D

    1983-02-01

    We present case histories of two young children with episodes of hypoglycemia, elevation of SGOT, low insulin levels, increased urinary excretion of psi-hydroxy fatty acids (5-hydroxyhexanoic, 7-hydroxyoctanoic and 9-hydroxydecanoic), traces of the corresponding psi-ketoacids and elevations of urinary adipic, suberic, and sebacic acids. The ratio of psi-hydroxy fatty acids to 3-hydroxybutyric in the urine of these patients is higher than in patients of similar ages with similar illnesses. These acids persisted while the patients were well. Increased urinary psi-hydroxy fatty acids could be reproduced by a load of medium chain triglycerides without precipitating other clinical symptoms. Three children with hypoglycemia were found not to excrete measurable amounts of these unusual acids while ill. A medium chain triglyceride load in one of these children after recovery failed to elicit psi-hydroxy acid excretion. Small amounts of urinary 5-hydroxyhexanoic acid only were found in two patients with acute Reye's syndrome and in three of five severely ill children with starvation ketonuria. In this last group, no urinary psi-hydroxyacids could be detected after recovery. Normal children do not excrete measurable amounts (less than 1 mg/g creatinine) of these psi-hydroxyacids.

  9. Metabolic Engineering of a Novel Muconic Acid Biosynthesis Pathway via 4-Hydroxybenzoic Acid in Escherichia coli

    PubMed Central

    Sengupta, Sudeshna; Goonewardena, Lakshani; Juturu, Veeresh

    2015-01-01

    cis,cis-Muconic acid (MA) is a commercially important raw material used in pharmaceuticals, functional resins, and agrochemicals. MA is also a potential platform chemical for the production of adipic acid (AA), terephthalic acid, caprolactam, and 1,6-hexanediol. A strain of Escherichia coli K-12, BW25113, was genetically modified, and a novel nonnative metabolic pathway was introduced for the synthesis of MA from glucose. The proposed pathway converted chorismate from the aromatic amino acid pathway to MA via 4-hydroxybenzoic acid (PHB). Three nonnative genes, pobA, aroY, and catA, coding for 4-hydroxybenzoate hydrolyase, protocatechuate decarboxylase, and catechol 1,2-dioxygenase, respectively, were functionally expressed in E. coli to establish the MA biosynthetic pathway. E. coli native genes ubiC, aroFFBR, aroE, and aroL were overexpressed and the genes ptsH, ptsI, crr, and pykF were deleted from the E. coli genome in order to increase the precursors of the proposed MA pathway. The final engineered E. coli strain produced nearly 170 mg/liter of MA from simple carbon sources in shake flask experiments. The proposed pathway was proved to be functionally active, and the strategy can be used for future metabolic engineering efforts for production of MA from renewable sugars. PMID:26362984

  10. B vitamin supplementation reduces excretion of urinary dicarboxylic acids in autistic children.

    PubMed

    Kałużna-Czaplińska, Joanna; Socha, Ewa; Rynkowski, Jacek

    2011-07-01

    Urinary dicarboxylic acids are an important source of information about metabolism and potential problems especially connected with energy production, intestinal dysbiosis, and nutritional individuality in autistic children. A diet rich in vitamins and macroelements is a new idea of intervention in autism. The objective of the present study was to test the hypothesis that vitamin B2, vitamin B6, and magnesium supplementation is effective in reducing the level of dicarboxylic acids in the urine of autistic children. We examined the levels of succinic, adipic, and suberic acids in the urine of autistic children before and after vitamin supplementation. Thirty children with autism received magnesium (daily dose, 200 mg), vitamin B6 (pyridoxine; daily dose, 500 mg), and vitamin B2 (riboflavin; daily dose, 20 mg). The treatment was provided for a period of 3 months. Organic acids were determined using gas chromatography/mass spectrometry. Before supplementation, the levels of succinic, adipic, and suberic acids in the urine of autistic children were 41.47 ± 50.40 μmol/mmol creatinine, 15.61 ± 15.31 μmol/mmol creatinine, 8.02 ± 6.08 μmol/mmol creatinine; and after supplementation, the levels were 9.90 ± 8.26 μmol/mmol creatinine, 2.92 ± 2.41 μmol/mmol creatinine, and 2.57 ± 3.53 μmol/mmol creatinine, respectively. The results suggest that the supplementation reduces the level of dicarboxylic acid in the urine of autistic children.

  11. Renewable unsaturated polyesters from muconic acid

    DOE PAGES

    Rorrer, Nicholas A.; Dorgan, John R.; Vardon, Derek R.; ...

    2016-09-27

    cis,cis-Muconic acid is an unsaturated dicarboxylic acid that can be produced in high yields via biological conversion of sugars and lignin-derived aromatic compounds. Muconic acid is often targeted as an intermediate to direct replacement monomers such as adipic or terephthalic acid. However, the alkene groups in muconic acid provide incentive for its direct use in polymers, for example, in the synthesis of unsaturated polyester resins. Here, biologically derived muconic acid is incorporated into polyesters via condensation polymerization using the homologous series of poly(ethylene succinate), poly(propylene succinate), poly(butylene succinate), and poly(hexylene succinate). Additionally, dimethyl cis,cis-muconate is synthesized and subsequently incorporated intomore » poly(butylene succinate). NMR measurements demonstrate that alkene bonds are present in the polymer backbones. In all cases, the glass transition temperatures are increased whereas the melting and degradation temperatures are decreased. In the case of poly(butylene succinate), utilization of neat muconic acid yields substoichiometric incorporation consistent with a tapered copolymer structure, whereas the muconate diester exhibits stoichiometric incorporation and a random copolymer structure based on thermal and mechanical properties. Prototypical fiberglass panels were produced by infusing a mixture of low molecular weight poly(butylene succinate-co-muconate) and styrene into a woven glass mat and thermally initiating polymerization resulting in thermoset composites with shear moduli in excess of 30 GPa, a value typical of commercial composites. The increased glass transition temperatures with increasing mucconic incorporation leads to improved composites properties. We find that the molecular tunability of poly(butylene succinate-co-muconate) as a tapered or random copolymer enables the tunability of composite properties. Altogether, this study demonstrates the utility of muconic acid as a

  12. Renewable unsaturated polyesters from muconic acid

    SciTech Connect

    Rorrer, Nicholas A.; Dorgan, John R.; Vardon, Derek R.; Martinez, Chelsea R.; Yang, Yuan; Beckham, Gregg T.

    2016-09-27

    cis,cis-Muconic acid is an unsaturated dicarboxylic acid that can be produced in high yields via biological conversion of sugars and lignin-derived aromatic compounds. Muconic acid is often targeted as an intermediate to direct replacement monomers such as adipic or terephthalic acid. However, the alkene groups in muconic acid provide incentive for its direct use in polymers, for example, in the synthesis of unsaturated polyester resins. Here, biologically derived muconic acid is incorporated into polyesters via condensation polymerization using the homologous series of poly(ethylene succinate), poly(propylene succinate), poly(butylene succinate), and poly(hexylene succinate). Additionally, dimethyl cis,cis-muconate is synthesized and subsequently incorporated into poly(butylene succinate). NMR measurements demonstrate that alkene bonds are present in the polymer backbones. In all cases, the glass transition temperatures are increased whereas the melting and degradation temperatures are decreased. In the case of poly(butylene succinate), utilization of neat muconic acid yields substoichiometric incorporation consistent with a tapered copolymer structure, whereas the muconate diester exhibits stoichiometric incorporation and a random copolymer structure based on thermal and mechanical properties. Prototypical fiberglass panels were produced by infusing a mixture of low molecular weight poly(butylene succinate-co-muconate) and styrene into a woven glass mat and thermally initiating polymerization resulting in thermoset composites with shear moduli in excess of 30 GPa, a value typical of commercial composites. The increased glass transition temperatures with increasing mucconic incorporation leads to improved composites properties. We find that the molecular tunability of poly(butylene succinate-co-muconate) as a tapered or random copolymer enables the tunability of composite properties. Altogether, this study demonstrates the utility of muconic acid as

  13. Resolution of a Challenge for Solvation Modeling: Calculation of Dicarboxylic Acid Dissociation Constants Using Mixed Discrete-Continuum Solvation Models

    SciTech Connect

    Marenich, Aleksandr; Ding, Wendu; Cramer, Christopher J.; Truhlar, Donald G.

    2012-06-07

    First and second dissociation constants (pKa values) of oxalic acid, malonic acid, and adipic acid were computed by using a number of theoretical protocols based on density functional theory and using both continuum solvation models and mixed discrete-continuum solvation models. We show that fully implicit solvation models (in which the entire solvent is represented by a dielectric continuum) fail badly for dicarboxylic acids with mean unsigned errors averaged over six pKa values) of 2.4-9.0 log units, depending on the particular implicit model used. The use of water-solute clusters and accounting for multiple conformations in solution significantly improve the performance of both generalized Born solvation models and models that solve the nonhomogeneous dielectric Poisson equation for bulk electrostatics. The four most successful models have mean unsigned errors of only 0.6-0.8 log units.

  14. Dicarboxylic acids with limited numbers of hydrocarbons stabilize cell membrane and increase osmotic resistance in rat erythrocytes.

    PubMed

    Mineo, Hitoshi; Amita, Nozomi; Kawawake, Megumi; Higuchi, Ayaka

    2013-11-01

    We examined the effect of dicarboxylic acids having 0 to 6 hydrocarbons and their corresponding monocarboxylic or tricarboxylic acids in changing the osmotic fragility (OF) in rat red blood cells (RBCs). Malonic, succinic, glutaric and adipic acids, which are dicarboxylic acids with 1, 2, 3 and 4 straight hydrocarbons located between two carboxylic groups, decreased the OF in a concentration-dependent manner. Other long-chain dicarboxylic acids did not change the OF in rat RBCs. The benzoic acid derivatives, isophthalic and terephthalic acids, but not phthalic acid, decreased the OF in a concentration-dependent manner. Benzene-1,2,3-tricarboxylic acid, but not benzene-1,3,5-tricarboxylic acid, also decreased the OF in rat RBCs. On the other hand, monocarboxylic acids possessing 2 to 7 straight hydrocarbons and benzoic acid increased the OF in rat RBCs. In short-chain dicarboxylic acids, a limited number of hydrocarbons between the two carboxylic groups are thought to form a V- or U-shaped structure and interact with phospholipids in the RBC membrane. In benzene dicarboxylic and tricarboxylic acids, a part of benzene nucleus between the two carboxylic groups is thought to enter the plasma membrane and act on acyl-chain in phospholipids in the RBC membrane. For dicarboxylic and tricarboxylic acids, limited numbers of hydrocarbons in molecules are speculated to enter the RBC membrane with the hydrophilic carboxylic groups remaining outside, stabilizing the structure of the cell membrane and resulting in an increase in osmotic resistance in rat RBCs.

  15. Metabolic profile of mephedrone: Identification of nor-mephedrone conjugates with dicarboxylic acids as a new type of xenobiotic phase II metabolites.

    PubMed

    Linhart, Igor; Himl, Michal; Židková, Monika; Balíková, Marie; Lhotková, Eva; Páleníček, Tomáš

    2016-01-05

    Metabolic profile of mephedrone (4-methylmethcathinone, 4-MMC), a frequently abused recreational drug, was determined in rats in vivo. The urine of rats dosed with a subcutaneous bolus dose of 20mg 4-MMC/kg was analysed by LC/MS. Ten phase I and five phase II metabolites were identified by comparison of their retention times and MS(2) spectra with those of authentic reference standards and/or with the MS(2) spectra of previously identified metabolites. The main metabolic pathway was N-demethylation leading to normephedrone (4-methylcathinone, 4-MC) which was further conjugated with succinic, glutaric and adipic acid. Other phase I metabolic pathways included oxidation of the 4-methyl group, carbonyl reduction leading to dihydro-metabolites and ω-oxidation at the position 3'. Five of the metabolites detected, namely, 4-carboxynormephedrone (4-carboxycathinone, 4-CC), 4-carboxydihydronormephedrone (4-carboxynorephedrine, 4-CNE), hydroxytolyldihydro-normephedrone (4-hydroxymethylnorephedrine, 4-OH-MNE) and conjugates of 4-MC with glutaric and adipic acid, have not been reported as yet. The last two conjugates represent a novel, hitherto unexploited, type of phase II metabolites in mammals together with an analogous succinic acid conjugate of 4-MC identified by Pozo et al. (2015). These conjugates might be potentially of great importance in the metabolism of other psychoactive amines.

  16. Long-distance inter-hydrogen bond coupling effects in the polarized IR spectra of succinic acid crystals

    NASA Astrophysics Data System (ADS)

    Flakus, Henryk T.; Hachuła, Barbara; Hołaj-Krzak, Jakub T.

    2015-05-01

    The spectral properties of four different crystalline succinic acid (HOOC-(CH2)2-COOH) (SAC) isotopomer systems, h6, d2, d4 and d6, were examined by means of the IR spectroscopy in polarized light aided by numerical simulations of the νO-H and νO-D band contour shapes on utilizing the "strong-coupling" model. The abnormal IR spectral properties of SAC crystals in relation to the corresponding properties of glutaric, pimelic and adipic acid crystals were ascribed to the hyperconjugation electronic effects in the acid associated molecules. A vibronic coupling mechanism involving the proton stretching vibrations in the (COOH)2 cycles and the electronic motions in the molecular skeletons, the isotopic "H/D self-organization" mechanisms and a long-distance vibrational exciton coupling between the adjacent (COOH)2 cycles in the molecular chains are mainly responsible for the generation of the temperature effects in the crystalline IR spectra.

  17. The Heterogeneous Photocatalytic Decomposition of Benzoic Acid and Adipic Acid on Platinized TiO2 Powder. The Photo-Kolbe Decarboxylative Route to the Breakdown of the Benzene Ring and to the Production to Butane.

    DTIC Science & Technology

    1980-10-29

    photocatalyst design dis- cussed previously, lb’Ic where the rate of reaction at the catalyst powder is determined by the system operating at a potential... photocatalyst half reaction, as opposed to the results on aliphatic carboxylates. The reduction of oxygen on Pt (curve 7) occurs ai. potentials much more positive...semiconductor powders have been shown to behave as photocatalysts and promote the oxidation of sub- strates. 1-6 Irradiation of a semiconductor with

  18. Capillary electrophoretic study of dibasic acids of different structures: Relation to separation of oxidative intermediates in remediation

    SciTech Connect

    Yu, Z.; Cocke, D.L.

    1998-09-01

    Dicarboxylic acids are important in environmental chemistry because they are intermediates in oxidative processes involved in natural remediation and waste management processes such as oxidative detoxification and advanced oxidation. Capillary electrophoresis (CE), a promising technique for separating and analyzing these intermediates, has been used to examine a series of dibasic acids of different structures and conformations. This series includes malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, phthalic acid, and trans, trans-muconic acid. The CE parameters as well as structural variations (molecular structure and molecular isomers, buffer composition, pH, applied voltage, injection mode, current, temperature, and detection wavelength) that affect the separations and analytical results have been examined in this study. Those factors that affect the separation have been delineated. Among these parameters, the pH has been found to be the most important, which affects the double-layer of the capillary wall, the electro-osmotic flow and analyte mobility. The optimum pH for separating these dibasic acids, as well as the other parameters are discussed in detail and related to the development of methods for analyzing oxidation intermediates in oxidative waste management procedures.

  19. Aqueous Phase Photo-Oxidation of Succinic Acid: Changes in Hygroscopic Properties and Reaction Products

    NASA Astrophysics Data System (ADS)

    Hudson, P. K.; Ninokawa, A.; Hofstra, J.; de Lijser, P.

    2013-12-01

    Atmospheric aerosol particles have been identified as important factors in understanding climate change. The extent to which aerosols affect climate is determined, in part, by hygroscopic properties which can change as a result of atmospheric processing. Dicarboxylic acids, components of atmospheric aerosol, have a wide range of hygroscopic properties and can undergo oxidation and photolysis reactions in the atmosphere. In this study, the hygroscopic properties of succinic acid aerosol, a non-hygroscopic four carbon dicarboxylic acid, were measured with a humidified tandem differential mobility analyzer (HTDMA) and compared to reaction products resulting from the aqueous phase photo-oxidation reaction of hydrogen peroxide and succinic acid. Reaction products were determined and quantified using gas chromatography-flame ionization detection (GC-FID) and GC-mass spectrometry (GC-MS) as a function of hydrogen peroxide:succinic acid concentration ratio and photolysis time. Although reaction products include larger non-hygroscopic dicarboxylic acids (e.g. adipic acid) and smaller hygroscopic dicarboxylic acids (e.g. malonic and oxalic acids), comparison of hygroscopic growth curves to Zdanovskii-Stokes-Robinson (ZSR) predictions suggests that the hygroscopic properties of many of the product mixtures are largely independent of the hygroscopicity of the individual components. This study provides a framework for future investigations to fully understand and predict the role of chemical reactions in altering atmospheric conditions that affect climate.

  20. Isoquercitrin Esters with Mono- or Dicarboxylic Acids: Enzymatic Preparation and Properties

    PubMed Central

    Vavříková, Eva; Langschwager, Fanny; Jezova-Kalachova, Lubica; Křenková, Alena; Mikulová, Barbora; Kuzma, Marek; Křen, Vladimír; Valentová, Kateřina

    2016-01-01

    A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside) esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica), which accepted C5- to C12-dicarboxylic acids; the shorter ones, such as oxalic (C2), malonic (C3), succinic (C4) and maleic (C4) acids were not substrates of the lipase. Lipophilicity of monocarboxylic acid derivatives, measured as log P, increased with the chain length. Esters with glutaric and adipic acids exhibited hydrophilicity, and the dodecanedioic acid hemiester was more lipophilic. All derivatives were less able to reduce Folin–Ciocalteau reagent (FCR) and scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) than isoquercitrin; ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was comparable. Dodecanoate and palmitate were the least active in FCR and ABTS scavenging; dodecanoate and hemiglutarate were the strongest DPPH scavengers. In contrast, most derivatives were much better inhibitors of microsomal lipoperoxidation than isoquercitrin; butyrate and hexanoate were the most efficient. Anti-lipoperoxidant activity of monocarboxylic derivatives, except acetates, decreased with increasing aliphatic chain. The opposite trend was noted for dicarboxylic acid hemiesters, isoquercitrin hemidodecanedioate being the most active. Overall, IQ butyrate, hexanoate and hemidodecanedioate are the most promising candidates for further studies. PMID:27338349

  1. Isoquercitrin Esters with Mono- or Dicarboxylic Acids: Enzymatic Preparation and Properties.

    PubMed

    Vavříková, Eva; Langschwager, Fanny; Jezova-Kalachova, Lubica; Křenková, Alena; Mikulová, Barbora; Kuzma, Marek; Křen, Vladimír; Valentová, Kateřina

    2016-06-07

    A series of isoquercitrin (quercetin-3-O-β-d-glucopyranoside) esters with mono- or dicarboxylic acids was designed to modulate hydro- and lipophilicity and biological properties. Esterification of isoquercitrin was accomplished by direct chemoenzymatic reaction using Novozym 435 (lipase from Candida antarctica), which accepted C₅- to C12-dicarboxylic acids; the shorter ones, such as oxalic (C₂), malonic (C₃), succinic (C₄) and maleic (C₄) acids were not substrates of the lipase. Lipophilicity of monocarboxylic acid derivatives, measured as log P, increased with the chain length. Esters with glutaric and adipic acids exhibited hydrophilicity, and the dodecanedioic acid hemiester was more lipophilic. All derivatives were less able to reduce Folin-Ciocalteau reagent (FCR) and scavenge DPPH (1,1-diphenyl-2-picrylhydrazyl) than isoquercitrin; ABTS (2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) radical-scavenging activity was comparable. Dodecanoate and palmitate were the least active in FCR and ABTS scavenging; dodecanoate and hemiglutarate were the strongest DPPH scavengers. In contrast, most derivatives were much better inhibitors of microsomal lipoperoxidation than isoquercitrin; butyrate and hexanoate were the most efficient. Anti-lipoperoxidant activity of monocarboxylic derivatives, except acetates, decreased with increasing aliphatic chain. The opposite trend was noted for dicarboxylic acid hemiesters, isoquercitrin hemidodecanedioate being the most active. Overall, IQ butyrate, hexanoate and hemidodecanedioate are the most promising candidates for further studies.

  2. Thermoplastic starch/polyester films: effects of extrusion process and poly (lactic acid) addition.

    PubMed

    Shirai, Marianne Ayumi; Olivato, Juliana Bonametti; Garcia, Patrícia Salomão; Müller, Carmen Maria Olivera; Grossmann, Maria Victória Eiras; Yamashita, Fabio

    2013-10-01

    Biodegradable films were produced using the blown extrusion method from blends that contained cassava thermoplastic starch (TPS), poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA) with two different extrusion processes. The choice of extrusion process did not have a significant effect on the mechanical properties, water vapor permeability (WVP) or viscoelasticity of the films, but the addition of PLA decreased the elongation, blow-up ratio (BUR) and opacity and increased the elastic modulus, tensile strength and viscoelastic parameters of the films. The films with 20% PLA exhibited a lower WVP due to the hydrophobic nature of this polymer. Morphological analyses revealed the incompatibility between the polymers used.

  3. Impact property enhancement of poly (lactic acid) with different flexible copolymers

    NASA Astrophysics Data System (ADS)

    Likittanaprasong, N.; Seadan, M.; Suttiruengwong, S.

    2015-07-01

    The objective of this work was to improve the impact property of Poly (lactic acid) (PLA) by blending with different copolymers. Six flexible copolymers, namely, acrylonitrile butadiene styrene (ABS) powder, Biomax, polybutyrate adipate co-terephthalate (PBAT), polyether block amide (PEBAX), ethylene-vinyl acetate (EVA) and ethylene acrylic elastomer (EAE), with loading less than 20wt% were used and compared. The rheological, mechanical and morphological properties of samples were investigated by melt flow index, tensile testing, impact testing and scanning electron microscope (SEM), respectively. It was found that PLA added 20wt% EAE showed the highest impact strength (59.5 kJ/m2), which was 22 times higher than neat PLA. The elongation at break was also increased by 12 folds compared to neat PLA. The SEM images showed good interface and distribution for PLA containing 20wt% EAE, 15 phr Biomax and 20 wt% PEBAX.

  4. Oxidative degradation of organic acids conjugated with sulfite oxidation in flue-gas desulfurization. Final report, June 1984-June 1986

    SciTech Connect

    Lee, Y.J.; Rochelle, G.T.

    1988-02-01

    This report gives results of a study of organic acid-degradation conjugated with sulfite oxidation under flue-gas desulfurization (FGD) conditions. The oxidative degradation constant, k12, is defined as the ratio of organic-acid degradation rate and sulfite oxidation-rate times the ratio of the concentrations of dissolved S(IV) and organic acid. It is not significantly affected by pH or dissolved oxygen in the absence of Mn or Fe. However, k12 is increased by certain transition metals such as Fe, Co, and Ni and is decreased by Mn and halides. Lower dissolved S(IV) magnifies these effects. A free-radical mechanism was proposed to describe the kinetics. Hydroxy and sulfonated carboxylic acids degrade approximately three times slower than saturated dicarboxylic acids; while maleic acid, an unsaturated dicarboxylic acid, degraded an order of magnitude faster. A wide spectrum of degradation products of adipic acid were found, including carbon dioxide (the major product), smaller dicarboxylic acids, monocarboxylic acids, other carbonyl compounds, and hydrocarbons.

  5. Oxidative degradation of organic acid conjugated with sulfite oxidation in flue gas desulfurization: products, kinetics and mechanism

    SciTech Connect

    Lee, Y.J.; Rochelle, G.T.

    1987-03-01

    Organic acid degradation conjugated with sulfite oxidation has been studied under flue gas desulfurization (FGD) conditions. The oxidative degradation constant k/sub 12/ is defined as the ratio of organic acid degradation rate and sulfite oxidation rate times the ratio of the concentration of dissolved S(IV) and organic acid. It is not significantly affected by pH or dissolved oxygen in the absence of manganese or iron. However, k/sub 12/ is increased by certain transition metals such as Fe, Co, and Ni and is decreased by Mn and halides. Lower dissolved S(IV) magnifies these effects. A free radical mechanism was proposed to describe the kinetics. Hydroxy and sulfonated carboxylic acids degrade approximately 3 times slower than saturated dicarboxylic acids, while maleic acid, an unsaturated dicarboxylic acid, degraded an order of magnitude factor. A wide spectrum of degradation products of adipic acid were found, including carbon dioxide - the major product - smaller dicarboxylic acids, monocarboxylic acids, other carbonyl compounds, and hydrocarbons. 30 references, 7 figures, 7 tables.

  6. 40 CFR 98.51 - Reporting threshold.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.51 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an adipic acid production process and the...

  7. 40 CFR 98.51 - Reporting threshold.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.51 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an adipic acid production process and the...

  8. 40 CFR 98.55 - Procedures for estimating missing data.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.55 Procedures for... (a) and (b) of this section. (a) For each missing value of monthly adipic acid production,...

  9. 40 CFR 98.57 - Records that must be retained.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.57 Records that must be retained... paragraphs (a) through (h) of this section at the facility level: (a) Annual adipic acid production...

  10. 40 CFR 98.51 - Reporting threshold.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.51 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an adipic acid production process and the...

  11. 40 CFR 98.55 - Procedures for estimating missing data.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROGRAMS (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.55 Procedures for... (a) and (b) of this section. (a) For each missing value of monthly adipic acid production,...

  12. 40 CFR 98.51 - Reporting threshold.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.51 Reporting threshold. You must report GHG emissions under this subpart if your facility contains an adipic acid production process and the...

  13. A new technique for studying directional cell migration in a hydrogel-based three-dimensional matrix for tissue engineering model systems.

    PubMed

    Topman, Gil; Shoham, Naama; Sharabani-Yosef, Orna; Lin, Feng-Huei; Gefen, Amit

    2013-08-01

    Cell migration has a key role in biological processes, e.g. malignancy, wound healing, immune response and morphogenesis. Studying migration and factors that influence it is beneficial, e.g. for developing drugs to suppress metastasis, heal wounds faster or enhance the response to infection. Though the majority of the literature describes two-dimensional (2D) migration studies in culture dishes, a more realistic approach is to study migration in three-dimensional (3D) constructs. However, simple-to-implement, straight-forward standardized quantitative techniques for analysis of migration rates of cell colonies in 3D are still required in the field. Here, we describe a new model system for quantifying directional migration of colonies in a hyaluronic acid (oxi-HA) and adipic acid dihydrazide (ADH) hydrogel-based 3D matrix. We further demonstrate that our previously reported image processing technique for measuring migration in 2D (Topman et al., 2011, 2012) is extendable for analyzing the rates of migration of cells that directionally migrate in the hydrogel and are fluorescently stained with a 4',6-diamidino-2-phenylindole (DAPI) nuclear stain. Together, the present experimental setup and image processing algorithm provide a standard test bench for measuring migration rates in a fully automated, robust assay which is useful for high-throughput screening in large-scale drug evaluations, where effects on migration in a 3D matrix are sought.

  14. Determination of Dicarboxylic Acid Concentrations in Surface Microlayer of Dams in Okinawa, Japan

    NASA Astrophysics Data System (ADS)

    Kotani, Y.; Taira, N.; Kamizato, C.; Arakaki, T.

    2008-12-01

    The surface microlayer (SML) is a thin layer that forms the boundary between atmosphere and water body. The SML includes fatty acid, protein and other organic compounds. It is the site across which the atmosphere-water system interacts. It also has unique chemical, physical and biological properties, which are very different from those of the underlying water. We determined concentrations of dicarboxylic acids (oxalic, malic, malonic, succinic, adipic, phthalic, fumaric, and maleic acids) in the SML, and compared with those of underlying bulk water. Dicarboxylic acids are the major organic compounds found in atmospheric aerosols, which can be derived from the wind-blown SML. The sampling sites we chose were dams in Okinawa, Japan. The SML was sampled by using a glass plate method. Concentrations of dicarboxylic acids were determined by using a GC-FID after derivatization. The results showed that the dicarboxylic acid concentrations were 2- 17 times higher than those of the underlying water. We have also found that the concentrations of some of the dicarboxylic acids were lower in the afternoon than those in the morning at the same sampling site.

  15. Implication of azelaic acid in a Greenland Ice Core for oceanic and atmospheric changes in high latitudes

    NASA Astrophysics Data System (ADS)

    Kawamura, K.; Yokoyama, K.; Fujii, Y.; Watanabe, O.

    A Greenland ice core (450 years) has been studied for low molecular weight dicarboxylic acids (C2-C10) using a capillary gas chromatography and mass spectrometer. Their molecular distribution generally showed a predominance of succinic acid (C4) followed by oxalic (C2), malonic (C3), glutaric (C5), adipic (C6), and azelaic (C9) acids. Azelaic acid, that is a specific photochemical reaction product of biogenic unsaturated fatty acids, gave a characteristic historical trend in the ice core; i.e., the concentrations are relatively low during late 16th to 19th century (Little Ice Age) but become very high in late 19th to 20th century (warmer periods) with a large peak in 1940s AD. Lower concentrations of azelaic acid may have been caused by a depressed emission of unsaturated fatty acids from seawater microlayers due to enhanced sea ice coverage during Little Ice Age. Inversely, increased concentrations of azelaic acid in late 19th to 20th century are likely interpreted by an enhanced sea-to-air emission of the precursor unsaturated fatty acids due to a retreat of sea ice and/or by the enhanced production due to a potentially increased oxidizing capability of the atmosphere.

  16. Characterizing Corrosion Effects of Weak Organic Acids Using a Modified Bono Test

    NASA Astrophysics Data System (ADS)

    Zhou, Yuqin; Turbini, Laura J.; Ramjattan, Deepchand; Christian, Bev; Pritzker, Mark

    2013-12-01

    To meet environmental requirements and achieve benefits of cost-effective manufacturing, no-clean fluxes (NCFs) or low-solids fluxes have become popular in present electronic manufacturing processes. Weak organic acids (WOAs) as the activation ingredients in NCFs play an important role, especially in the current lead-free and halogen-free soldering technology era. However, no standard or uniform method exists to characterize the corrosion effects of WOAs on actual metallic circuits of printed wiring boards (PWBs). Hence, the development of an effective quantitative test method for evaluating the corrosion effects of WOAs on the PWB's metallic circuits is imperative. In this paper, the modified Bono test, which was developed to quantitatively examine the corrosion properties of flux residues, is used to characterize the corrosion effects of five WOAs (i.e., abietic acid, succinic acid, glutaric acid, adipic acid, and malic acid) on PWB metallic circuits. Experiments were performed under three temperature/humidity conditions (85°C/85% RH, 60°C/93% RH, and 40°C/93% RH) using two WOA solution concentrations. The different corrosion effects among the various WOAs were best reflected in the testing results at 40°C and 60°C. Optical microscopy was used to observe the morphology of the corroded copper tracks, and scanning electron microscopy (SEM) energy-dispersive x-ray (EDX) characterization was performed to determine the dendrite composition.

  17. 40 CFR 98.53 - Calculating GHG emissions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.53 Calculating GHG emissions. (a) You must determine annual N2O emissions from adipic acid production according to paragraphs (a)(1) or... adipic acid production units exhaust to a common abatement technology and/or emission point, you...

  18. 40 CFR 98.53 - Calculating GHG emissions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... adipic acid production (determined in paragraph (f) of this section) according to Equation E-3d of this... adipic acid production for unit “z” according to this Equation E-3d (metric tons). EFN 2 O = N2O... emissions from adipic acid production unit “z” according to Equation E-3d of this section (metric tons)....

  19. Synthesis and Characterization of Lipooligosaccharide-Based Conjugates as Vaccine Candidates for Moraxella (Branhamella) catarrhalis

    PubMed Central

    Gu, Xin-Xing; Chen, Jing; Barenkamp, Stephen J.; Robbins, John B.; Tsai, Chao-Ming; Lim, David J.; Battey, James

    1998-01-01

    Moraxella (Branhamella) catarrhalis is an important cause of otitis media and sinusitis in children and of lower respiratory tract infections in adults. Lipooligosaccharide (LOS) is a major surface antigen of the bacterium and elicits bactericidal antibodies. Treatment of the LOS from strain ATCC 25238 with anhydrous hydrazine reduced its toxicity 20,000-fold, as assayed in the Limulus amebocyte lysate (LAL) test. The detoxified LOS (dLOS) was coupled to tetanus toxoid (TT) or high-molecular-weight proteins (HMP) from nontypeable Haemophilus influenzae through a linker of adipic acid dihydrazide to form dLOS-TT or dLOS-HMP. The molar ratios of dLOS to TT and HMP conjugates were 19:1 and 31:1, respectively. The antigenicity of the two conjugates was similar to that of the LOS, as determined by double immunodiffusion. Subcutaneous or intramuscular injection of both conjugates elicited a 50- to 100-fold rise in the geometric mean of immunoglobulin G (IgG) to the homologous LOS in mice after three injections and a 350- to 700-fold rise of anti-LOS IgG in rabbits after two injections. The immunogenicity of the conjugate was enhanced by formulation with monophosphoryl lipid A plus trehalose dimycolate. In rabbits, conjugate-induced antisera had complement-mediated bactericidal activity against the homologous strain and heterologous strains of M. catarrhalis. These results indicate that a detoxified LOS-protein conjugate is a candidate for immunization against M. catarrhalis diseases. PMID:9573066

  20. Physico-chemical properties of Salmonella typhi Vi polysaccharide-diphtheria toxoid conjugate vaccines affect immunogenicity.

    PubMed

    An, So Jung; Yoon, Yeon Kyung; Kothari, Sudeep; Kothari, Neha; Kim, Jeong Ah; Lee, Eugene; Kim, Deok Ryun; Park, Tai Hyun; Smith, Greg W; Carbis, Rodney

    2011-10-13

    In this study it was demonstrated that the immunogenicity of Vi polysaccharide-diphtheria toxoid conjugates was related to the physical and chemical structure of the conjugate. Conjugates were prepared in two steps, firstly binding adipic acid dihydrazide (ADH) spacer molecules to diphtheria toxoid (DT) carrier protein then secondly binding varying amounts of this derivatized DT to a fixed amount of Vi capsular polysaccharide purified from Salmonella enterica Serovar Typhi. As the amount of DT bound to the Vi increased the size of the conjugate increased but also the degree of cross-linking increased. The immunogenicity of the conjugates was tested in mice and measured by ELISA for anti Vi and anti DT IgG responses, and the results revealed a trend that as the amount of DT bound to the Vi increased the anti Vi responses increased. This study establishes a correlation between physico-chemical characteristics of the conjugate and the magnitude of the anti Vi and anti DT responses.

  1. Purification and identification of the fusicoccin binding protein from oat root plasma membrane

    NASA Technical Reports Server (NTRS)

    de Boer, A. H.; Watson, B. A.; Cleland, R. E.

    1989-01-01

    Fusicoccin (FC), a fungal phytotoxin, stimulates the H(+) -ATPase located in the plasma membrane (PM) of higher plants. The first event in the reaction chain leading to enhanced H(+) -efflux seems to be the binding of FC to a FC-binding protein (FCBP) in the PM. We solubilized 90% of the FCBP from oat (Avena sativa L. cv Victory) root PM in an active form with 1% octyl-glucoside. The FCBP was stabilized by the presence of protease inhibitors. The FCBP was purified by affinity chromatography using FC-linked adipic acid dihydrazide agarose (FC-AADA). Upon elution with 8 molar urea, two major protein bands on sodium dodecyl sulfate-polyaerylamide gel electrophoresis with molecular weights of 29,700 and 31,000 were obtained. Successive chromatography on BBAB Bio-Gel A, hexyl agarose, and FC-AADA resulted in the same two bands when the FC-AADA was eluted with sodium dodecyl sulfate. A direct correlation was made between 3H-FC-binding activity and the presence of the two protein bands. The stoichiometry of the 29,700 and 31,000 molecular weight bands was 1:2. This suggests that the FCBP occurs in the native form as a heterotrimer with an apparent molecular weight of approximately 92,000.

  2. Value of furfural/ethanol coproduction from acid hydrolysis processes

    SciTech Connect

    Parker, S.; Calnon, M.; Feinberg, D.; Power, A.; Weiss, L.

    1983-08-01

    The benefits of two modifications in the acid hydrolysis of cellulosic feedstocks for the production of ethanol fuels were investigated: marketing of the by-product furfural and xylose fermentation. Preliminary analysis indicate that the furfural by-product furfural and xylose fermentation. Perliminary analyses indicate that the furfural by-product credit is more beneficial at a minimum net profit of $0.08/lb of furfural. For this credit to have a major impact on ethanol production costs, new markets for large quantities of furfural must be identified. Furfural can be an alternative feedstock for hydrocarbon-based commodity chemicals. The costs and profitabilities of producing five chemicals from furfurals as opposed to conventional hydrocarbon-based feedstocks were studied. The furfural processes for production of styrene and butadiene were found to be marginally competitive or not competitive. The furfural processes for adipic acid, maleic anhydride, and butanol could be competitive. Results of analysis by a computer model of the petrochemical industry indicate that with furfural markets additional to these three furfural processes, over 2.5 x 10/sup 9/ gal of ethanol could be marketed at about $1.00/gal. Converting the xylose stream to ethanol has about the same effect on the selling price of ethanol as the furfural credit. The greatest ethanol production will result from xylose fermentation, but the furfural credit offers large near-term profits and has a more diversified impact on reducing petroleum product demand. 6 figures, 17 tables.

  3. Oxidative degradation of organic acids conjugated with sulfite oxidation in flue gas desulfurization

    SciTech Connect

    Lee, Y.I.

    1986-01-01

    Organic acid degradation conjugated with sulfite oxidation has been studied under flue gas desulfurization (EGD) conditions. The oxidative degradation constant, k/sub 12/, is defined as the ratio of organic acid degradation rate and sulfite oxidation rate after being normalized by the concentrations of organic acid and dissolved S(IV). K/sub 12/, not significantly affected by pH or dissolved oxygen, is around 10/sup -3/ in the absence of manganese or iron. However, k/sub 12/ is increased by certain transition metals such as Co, Ni, and Fe and is decreased by Mn and halides. Lower dissolved S(IV) magnified these effects. No k/sub 12/ greater than 4 x 10/sup -3/ or smaller than 0.1 x 10/sup -3/ has been observed. A free radical mechanism was proposed to describe the kinetics: (1) sulfate free radical is the major radical responsible to the degradation of organic acid; (2) ferrous generates sulfate radical by reacting with monoxypersulfate to enhance k/sub 12/; (3) manganous consumes sulfate radical to decrease k/sub 12/; (4) dissolved S(IV) competes with ferrous for monoxypersulfate and with manganous for sulfate radical to demonstrate the effects of dissolved S(IV) on k/sub 12/. Hydroxy and sulfonated carboxylic acids degrade approximately three times slower than saturated dicarboxylic acids; while maleic acid, an unsaturated dicarboxylic acid, degraded an order of magnitude faster. A wide spectrum of degradation products of adipic acid were found, including carbon dioxide - the major product, glutaric semialdehyde - the major retained product with low manganese, glutaric acid and valeric acids - the major retained product with high manganese, lower molecular weight mono- and dicarboxylic acids, other carbonyl compounds, and hydrocarbons.

  4. Latitudinal distributions of atmospheric dicarboxylic acids, oxocarboxylic acids, and α-dicarbonyls over the western North Pacific: Sources and formation pathways

    NASA Astrophysics Data System (ADS)

    Bikkina, Srinivas; Kawamura, Kimitaka; Miyazaki, Yuzo

    2015-05-01

    The present study aims to assess the molecular distributions of water-soluble dicarboxylic acids (diacids: C2-C12), oxocarboxylic acids (C2-C9), and α-dicarbonyls (glyoxal and methylglyoxal) in aerosols collected over the western North Pacific (WNP) during a summer cruise (August to September 2008). The measured water-soluble organics show pronounced latitudinal distributions with higher concentrations in the region of 30°N-45°N (average 63 ng m-3) than 10°N-30°N (18 ng m-3). Mass fraction of oxalic acid (C2) in total aliphatic diacids (ΣC2-C12) showed higher values (72 ± 10%) in lower latitude (10°N-30°N) than that (56 ± 16%) in higher latitude (30°N-45°N), suggesting a photochemical production of C2 due to an increased insolation over the tropical WNP. A similar trend was found in other diagnostic ratios such as oxalic to succinic (C2/C4) and oxalic to glyoxylic acid (C2/ωC2), which further corroborate an enhanced photochemical aging over the WNP. In addition, relative abundances of oxalic acid in total diacids showed a marked increase as a function of ambient temperature, supporting their photochemical production. Constantly low concentration ratios of adipic and phthalic acids relative to azelaic acid suggest a small contribution of anthropogenic sources and an importance of oceanic sources during the study period. Significant production of C2 through oxidation of biogenic volatile organic compounds emitted from the sea surface is also noteworthy, as inferred from the strong linear correlations among water-soluble organic carbon, methanesulphonic acid, and oxalic acid. Sea-to-air emission of unsaturated fatty acids also contributes to formation of diacids over the WNP.

  5. Structure and end-group analysis of complex hexanediol-neopentylglycol-adipic acid copolyesters by matrix-assisted laser desorption/ionization collision-induced dissociation tandem mass spectrometry.

    PubMed

    Weidner, Steffen M; Falkenhagen, Jana; Knop, Karin; Thünemann, Andreas

    2009-09-01

    Sequences and end groups of complex copolyesters were determined by fragmentation analysis by means of matrix-assisted laser desorption/ionization collision-induced dissociation tandem mass spectrometry (MALDI CID MS/MS). The complexity of the crude copolyester mixture was reduced by a chromatographic separation followed by a MALDI time-of-flight (TOF) investigation of fractions. Due to overlapping compositional and end-group information a clear assignment of end groups was very difficult. However, the fragmentation of suitable precursor ions resulted in typical fragment ion patterns and, therefore, enabled a fast and unambiguous determination of the end groups and composition of this important class of polymers.

  6. 40 CFR 98.54 - Monitoring and QA/QC requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.54 Monitoring and QA/QC... methods used to determine the representative point. (2) Conduct the performance test when your adipic acid...); or (3) An equivalent method, with Administrator approval. (c) You must determine the adipic...

  7. Carboxylic acids in gas and PM2.5 particulate phase at a rural mountain site in northeastern United States

    NASA Astrophysics Data System (ADS)

    Hussain, M. M.; Khan, A. R.; Khwaja, H. A.

    2009-12-01

    Low molecular weight carboxylic acids are important constituents of the organic fraction of atmospheric particulate matter in rural and polluted regions. The knowledge on their source is sparse, however, and organic aerosols in general need to better characterized. Atmospheric gas- and particle-phase carboxylic acids (formic, acetic, pyruvic, glyoxalic, benzoaic, adipic, succinic, malonic, and oxalic) and related compounds were measured during August 2002 at a rural site, Whiteface Mountain, NY. Formic and acetic acids were present in the PM2.5 fraction and in the gas phase. Other seven carboxylic acids were below the detection limit in all samples. Formic and acetic acid were present in the atmosphere mostly in the gaseous form with less than 10% in the PM2.5 fraction. Concentrations of formic acid and acetic acid were in the 0.5 - 2.4 ppbv and 0.6 - 1.9 ppbv ranges, respectively. Formic-to-acetic acid ratios less than one (0.88) were recorded, likely due to an increase in acetic acid contribution from direct emissions. In the fine particulate mode (PM2.5 ) the concentrations for acetic acid and formic acid were 120 - 400 and 10 - 180 ng/m3 , respectively. Backward trajectory data indicate that air mass originated at midwestern region on August 5th and gradually moved towards north on August 9th. Correlation of formic acid with sulfate was investigated to interpret their possible secondary formation pathways. A strong correlation (0.73) was observed between formic acid and sulfate in PM2.5 particulates. Since the source of sulfate found at Whiteface Mountain widely accepted as anthropogenic, its association with formic acid indicated that the later might have anthropogenic source.

  8. Controlled Release of Salicylic Acid from Biodegradable Cross-Linked Polyesters.

    PubMed

    Dasgupta, Queeny; Chatterjee, Kaushik; Madras, Giridhar

    2015-09-08

    The purpose of this work was to develop a family of cross-linked poly(xylitol adipate salicylate)s with a wide range of tunable release properties for delivering pharmacologically active salicylic acid. The synthesis parameters and release conditions were varied to modulate polyester properties and to understand the mechanism of release. Varying release rates were obtained upon longer curing (35% in the noncured polymer to 10% in the cured polymer in 7 days). Differential salicylic acid loading led to the synthesis of polymers with variable cross-linking and the release could be tuned (100% release for the lowest loading to 30% in the highest loading). Controlled release was monitored by changing various factors, and the release profiles were dependent on the stoichiometric composition, pH, curing time, and presence of enzyme. The polymer released a combination of salicylic acid and disalicylic acid, and the released products were found to be nontoxic. Minimal hemolysis and platelet activation indicated good blood compatibility. These polymers qualify as "bioactive" and "resorbable" and can, therefore, find applications as immunomodulatory resorbable biomaterials with tunable release properties.

  9. Optical Properties of Internally Mixed Aerosol Particles Composed of Dicarboxylic Acids and Ammonium Sulfate

    NASA Astrophysics Data System (ADS)

    Freedman, Miriam A.; Hasenkopf, Christa A.; Beaver, Melinda R.; Tolbert, Margaret A.

    2009-10-01

    We have investigated the optical properties of internally mixed aerosol particles composed of dicarboxylic acids and ammonium sulfate using cavity ring-down aerosol extinction spectroscopy at a wavelength of 532 nm. The real refractive indices of these nonabsorbing species were retrieved from the extinction and concentration of the particles using Mie scattering theory. We obtain refractive indices for pure ammonium sulfate and pure dicarboxylic acids that are consistent with literature values, where they exist, to within experimental error. For mixed particles, however, our data deviates significantly from a volume-weighted average of the pure components. Surprisingly, the real refractive indices of internal mixtures of succinic acid and ammonium sulfate are higher than either of the pure components at the highest organic weight fractions. For binary internal mixtures of oxalic or adipic acid with ammonium sulfate, the real refractive indices of the mixtures are approximately the same as ammonium sulfate for all organic weight fractions. Various optical mixing rules for homogeneous and slightly heterogeneous systems fail to explain the experimental real refractive indices. It is likely that complex particle morphologies are responsible for the observed behavior of the mixed particles. Implications of our results for atmospheric modeling and aerosol structure are discussed.

  10. Developing an Acidic Residue Reactive and Sulfoxide-Containing MS-Cleavable Homobifunctional Cross-Linker for Probing Protein–Protein Interactions

    PubMed Central

    2016-01-01

    Cross-linking mass spectrometry (XL-MS) has become a powerful strategy for defining protein–protein interactions and elucidating architectures of large protein complexes. However, one of the inherent challenges in MS analysis of cross-linked peptides is their unambiguous identification. To facilitate this process, we have previously developed a series of amine-reactive sulfoxide-containing MS-cleavable cross-linkers. These MS-cleavable reagents have allowed us to establish a common robust XL-MS workflow that enables fast and accurate identification of cross-linked peptides using multistage tandem mass spectrometry (MSn). Although amine-reactive reagents targeting lysine residues have been successful, it remains difficult to characterize protein interaction interfaces with little or no lysine residues. To expand the coverage of protein interaction regions, we present here the development of a new acidic residue-targeting sulfoxide-containing MS-cleavable homobifunctional cross-linker, dihydrazide sulfoxide (DHSO). We demonstrate that DHSO cross-linked peptides display the same predictable and characteristic fragmentation pattern during collision induced dissociation as amine-reactive sulfoxide-containing MS-cleavable cross-linked peptides, thus permitting their simplified analysis and unambiguous identification by MSn. Additionally, we show that DHSO can provide complementary data to amine-reactive reagents. Collectively, this work not only enlarges the range of the application of XL-MS approaches but also further demonstrates the robustness and applicability of sulfoxide-based MS-cleavability in conjunction with various cross-linking chemistries. PMID:27417384

  11. Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels

    NASA Astrophysics Data System (ADS)

    Hansen, A. M. K.; Kristensen, K.; Nguyen, Q. T.; Zare, A.; Cozzi, F.; Nøjgaard, J. K.; Skov, H.; Brandt, J.; Christensen, J. H.; Ström, J.; Tunved, P.; Krejci, R.; Glasius, M.

    2014-08-01

    Sources, composition and occurrence of secondary organic aerosols in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeastern Greenland, during the full annual cycle of 2008 and 2010, respectively. Speciation of organic acids, organosulfates and nitrooxy organosulfates - from both anthropogenic and biogenic precursors were in focus. A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate and 3-methyl-1,2,3-butanetricarboxylic acid), 12 organosulfates and 1 nitrooxy organosulfate were identified in aerosol samples from the two sites using a high-performance liquid chromatograph (HPLC) coupled to a quadrupole Time-of-Flight mass spectrometer. At Station Nord, compound concentrations followed a distinct annual pattern, where high mean concentrations of organosulfates (47 ± 14 ng m-3) and organic acids (11.5 ± 4 ng m-3) were observed in January, February and March, contrary to considerably lower mean concentrations of organosulfates (2 ± 3 ng m-3) and organic acids (2.2 ± 1 ng m-3) observed during the rest of the year. At Zeppelin Mountain, organosulfate and organic acid concentrations remained relatively constant during most of the year at a mean concentration of 15 ± 4 ng m-3 and 3.9 ± 1 ng m-3, respectively. However during four weeks of spring, remarkably higher concentrations of total organosulfates (23-36 ng m-3) and total organic acids (7-10 ng m-3) were observed. Elevated organosulfate and organic acid concentrations coincided with the Arctic haze period at both stations, where northern Eurasia was identified as the main source region. Air mass transport from northern Eurasia to Zeppelin Mountain was associated with a 100% increase in the number of detected organosulfate species compared with periods of air mass transport from the Arctic Ocean, Scandinavia and Greenland. The results from this

  12. Salt and cocrystals of sildenafil with dicarboxylic acids: solubility and pharmacokinetic advantage of the glutarate salt.

    PubMed

    Sanphui, Palash; Tothadi, Srinu; Ganguly, Somnath; Desiraju, Gautam R

    2013-12-02

    Sildenafil is a drug used to treat erectile dysfunction and pulmonary arterial hypertension. Because of poor aqueous solubility of the drug, the citrate salt, with improved solubility and pharmacokinetics, has been marketed. However, the citrate salt requires an hour to reach its peak plasma concentration. Thus, to improve solubility and bioavailability characteristics, cocrystals and salts of the drug have been prepared by treating aliphatic dicarboxylic acids with sildenafil; the N-methylated piperazine of the drug molecule interacts with the carboxyl group of the acid to form a heterosynthon. Salts are formed with oxalic and fumaric acid; salt monoanions are formed with succinic and glutaric acid. Sildenafil forms cocrystals with longer chain dicarboxylic acids such as adipic, pimelic, suberic, and sebacic acids. Auxiliary stabilization via C-H···O interactions is also present in these cocrystals and salts. Solubility experiments of sildenafil cocrystal/salts were carried out in 0.1N HCl aqueous medium and compared with the solubility of the citrate salt. The glutarate salt and pimelic acid cocrystal dissolve faster than the citrate salt in a two hour dissolution experiment. The glutarate salt exhibits improved solubility (3.2-fold) compared to the citrate salt in water. Solubilities of the binary salts follow an inverse correlation with their melting points, while the solubilities of the cocrystals follow solubilities of the coformer. Pharmacokinetic studies on rats showed that the glutarate salt exhibits doubled plasma AUC values in a single dose within an hour compared to the citrate salt. The high solubility of glutaric acid, in part originating from the strained conformation of the molecule and its high permeability, may be the reason for higher plasma levels of the drug.

  13. Supramolecular architectures in the co-crystals involving carboxylic acids and 1,2-bis(4-pyridyl)ethane, an extended bipyridyl type ligand

    NASA Astrophysics Data System (ADS)

    Ebenezer, Samuel; Muthiah, Packianathan Thomas

    2011-03-01

    In the present study 1,2-bis(4-pyridyl)ethane (BPA) crystallizes with 2-chlorobenzoic acid (2CBA), 4-methylbenzoic acid (4MBA), phthalic acid (PA), succinic acid (SA) and adipic acid (AA) to yield co-crystals BPA.2CBA ( 1), BPA.4MBA ( 2), BPA.PA ( 3), BPA.SA ( 4) and BPA.AA ( 5) respectively. All the five co-crystals are constituted by the utilization of the R22(7) synthon, created by the combination of hard N-H⋯O and complementary soft C-H⋯O hydrogen bonds. 1 and 2 illustrate the formation of three component aggregate as in both cases BPA interacts with carboxylic acids to form supramolecular ladder-type assembies. Molecular recognition in co-crystals 3-5 results in the formation of extended infinite tapes and differ further as a consequence of the soft C-H⋯O bonds and stacking interactions. Structure 3 shows the formation of zig-zag tapes while 4 and 5 form linear infinite tapes. Structure 4 shows isostructural behaviour with an analogous structure previously reported (Bowes et al. (2003) [77]).The isostructurality is because of the structural resemblance between both the entities in the co-crystals - fumaric acid/succinic acid and 1,2-bis(4-pyridyl)ethane/1,2-bis(4-pyridyl)ethene. Compound 5 shows good degree of resemblance with another reported analogous structure-1,2-bis(4-pyridyl)ethene adipic acid. (Zhang et al. (2003) [72]). Structure 5 and the reported structure form similar supramolecular sheets through intertape interactions differing from each other only in the alignment of neighboring tapes. The linear tapes in both the cases are linked laterally through different C-H⋯O interactions and ventrally through different stacking interactions. This work illustrates the construction of different supramolecular architectures and the role of weak C-H⋯O hydrogen bonds and stacking interactions in the higher level of supramolecular organization.

  14. Aspartic acid

    MedlinePlus

    ... also called asparaginic acid. Aspartic acid helps every cell in the body work. It plays a role in: Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as ...

  15. Folic Acid

    MedlinePlus

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  16. Folic Acid

    MedlinePlus

    Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

  17. Seasonal cycle and temperature dependence of pinene oxidation products, dicarboxylic acids and nitrophenols in fine and coarse air particulate matter

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Müller, L.; Winterhalter, R.; Moortgat, G. K.; Hoffmann, T.; Pöschl, U.

    2010-05-01

    Filter samples of fine and coarse air particulate matter (PM) collected over a period of one year in central Europe (Mainz, Germany) were analyzed for water-soluble organic compounds (WSOCs), including the α- and β-pinene oxidation products pinic acid, pinonic acid and 3-methyl-1,2,3-butanetricarboxylic acid (3-MBTCA), as well as a variety of dicarboxylic acids and nitrophenols. Seasonal variations and other characteristic features in fine, coarse, and total PM (TSP) are discussed with regard to aerosol sources and sinks in comparison to data from other studies and regions. The ratios of adipic acid and phthalic acid to azelaic acid indicate that the investigated samples were mainly influenced by biogenic sources. A strong Arrhenius-type correlation was found between the 3-MBTCA concentration and inverse temperature (R2=0.79, n=52, Ea=126±10 kJ mol-1, temperature range 275-300 K). Model calculations suggest that the temperature dependence observed for 3-MBTCA can be explained by enhanced photochemical production due to an increase of hydroxyl radical (OH) concentration with increasing temperature, whereas the influence of gas-particle partitioning appears to play a minor role. The results indicate that the OH-initiated oxidation of pinonic acid is the rate-limiting step in the formation of 3-MBTCA, and that 3-MBTCA may be a suitable tracer for the chemical aging of biogenic secondary organic aerosol (SOA) by OH radicals. An Arrhenius-type temperature dependence was also observed for the concentration of pinic acid (R2=0.60, n=56, Ea=84±9 kJ mol-1); it can be tentatively explained by the temperature dependence of biogenic pinene emission as the rate-limiting step of pinic acid formation.

  18. Seasonal cycle and temperature dependence of pinene oxidation products, dicarboxylic acids and nitrophenols in fine and coarse air particulate matter

    NASA Astrophysics Data System (ADS)

    Zhang, Y. Y.; Müller, L.; Winterhalter, R.; Moortgat, G. K.; Hoffmann, T.; Pöschl, U.

    2010-08-01

    Filter samples of fine and coarse air particulate matter (PM) collected over a period of one year in central Europe (Mainz, Germany) were analyzed for water-soluble organic compounds (WSOCs), including the α- and β-pinene oxidation products pinic acid, pinonic acid and 3-methyl-1,2,3-butanetricarboxylic acid (3-MBTCA), as well as a variety of dicarboxylic acids and nitrophenols. Seasonal variations and other characteristic features in fine, coarse, and total PM (TSP) are discussed with regard to aerosol sources and sinks in comparison to data from other studies and regions. The ratios of adipic acid and phthalic acid to azelaic acid indicate that the investigated aerosol samples were mainly influenced by biogenic sources. A strong Arrhenius-type correlation was found between the 3-MBTCA concentration and inverse temperature (R2 = 0.79, n = 52, Ea = 126 ± 10 kJ mol-1, temperature range 275-300 K). Model calculations suggest that the temperature dependence observed for 3-MBTCA can be explained by enhanced photochemical production due to an increase of hydroxyl radical (OH) concentration with increasing temperature, whereas the influence of gas-particle partitioning appears to play a minor role. The results indicate that the OH-initiated oxidation of pinonic acid is the rate-limiting step in the formation of 3-MBTCA, and that 3-MBTCA may be a suitable tracer for the chemical aging of biogenic secondary organic aerosol (SOA) by OH radicals. An Arrhenius-type temperature dependence was also observed for the concentration of pinic acid (R2 = 0.60, n = 56, Ea = 84 ± 9 kJ mol-1); it can be tentatively explained by the temperature dependence of biogenic pinene emission as the rate-limiting step of pinic acid formation.

  19. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.

    1995-01-01

    Although acid rain is fading as a political issue in the United States and funds for research in this area have largely disappeared, the acidity of rain in the Eastern United States has not changed significantly over the last decade, and it continues to be a serious environmental problem. Acid deposition (commonly called acid rain) is a term applied to all forms of atmospheric deposition of acidic substances - rain, snow, fog, acidic dry particulates, aerosols, and acid-forming gases. Water in the atmosphere reacts with certain atmospheric gases to become acidic. For example, water reacts with carbon dioxide in the atmosphere to produce a solution with a pH of about 5.6. Gases that produce acids in the presence of water in the atmosphere include carbon dioxide (which converts to carbonic acid), oxides of sulfur and nitrogen (which convert to sulfuric and nitric acids}, and hydrogen chloride (which converts to hydrochloric acid). These acid-producing gases are released to the atmosphere through natural processes, such as volcanic emissions, lightning, forest fires, and decay of organic matter. Accordingly, precipitation is slightly acidic, with a pH of 5.0 to 5.7 even in undeveloped areas. In industrialized areas, most of the acid-producing gases are released to the atmosphere from burning fossil fuels. Major emitters of acid-producing gases include power plants, industrial operations, and motor vehicles. Acid-producing gases can be transported through the atmosphere for hundreds of miles before being converted to acids and deposited as acid rain. Because acids tend to build up in the atmosphere between storms, the most acidic rain falls at the beginning of a storm, and as the rain continues, the acids "wash out" of the atmosphere.

  20. Concentrations of higher dicarboxylic acids C5-C13 in fresh snow samples collected at the High Alpine Research Station Jungfraujoch during CLACE 5 and 6

    NASA Astrophysics Data System (ADS)

    Winterhalter, R.; Kippenberger, M.; Williams, J.; Fries, E.; Sieg, K.; Moortgat, G. K.

    2009-03-01

    Samples of freshly fallen snow were collected at the high alpine research station Jungfraujoch (Switzerland) in February and March 2006 and 2007, during the Cloud and Aerosol Characterization Experiments (CLACE) 5 and 6. In this study a new technique has been developed and demonstrated for the measurement of organic acids in fresh snow. The melted snow samples were subjected to solid phase extraction and resulting solutions analysed for organic acids by HPLC-MS-TOF using negative electrospray ionization. A series of linear dicarboxylic acids from C5 to C13 and phthalic acid, were identified and quantified. In several samples the biogenic acid pinonic acid was also observed. In fresh snow the median concentration of the most abundant acid, adipic acid, was 0.69 μg L-1 in 2006 and 0.70 μg L-1 in 2007. Glutaric acid was the second most abundant dicarboxylic acid found with median values of 0.46 μg L-1 in 2006 and 0.61 μg L-1 in 2007, while the aromatic acid phthalic acid showed a median concentration of 0.34 μg L-1 in 2006 and 0.45 μg L-1 in 2007. The concentrations in the samples from various snowfall events varied significantly, and were found to be dependent on the back trajectory of the air mass arriving at Jungfraujoch. Air masses of marine origin showed the lowest concentrations of acids whereas the highest concentrations were measured when the air mass was strongly influenced by boundary layer air.

  1. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  2. Stable carbon isotopic compositions of total carbon, dicarboxylic acids and glyoxylic acid in the tropical Indian aerosols: Implications for sources and photochemical processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Pavuluri, Chandra Mouli; Kawamura, Kimitaka; Swaminathan, T.; Tachibana, Eri

    2011-09-01

    The tropical Indian aerosols (PM10) collected on day- and nighttime bases in winter and summer, 2007 from Chennai (13.04°N; 80.17°E) were studied for stable carbon isotopic compositions (δ13C) of total carbon (TC), individual dicarboxylic acids (C2-C9) and glyoxylic acid (ωC2). δ13C values of TC ranged from -23.9‰ to -25.9‰ (-25.0 ± 0.6‰; n = 49). Oxalic (C2) (-17.1 ± 2.5‰), malonic (C3) (-20.8 ± 1.8‰), succinic (C4) (-22.5 ± 1.5‰) and adipic (C6) (-20.6 ± 4.1‰) acids and ωC2 acid (-22.4 ± 5.5‰) were found to be more enriched with 13C compared to TC. In contrast, suberic (C8) (-29.4 ± 1.8‰), phthalic (Ph) (-30.1 ± 3.5‰) and azelaic (C9) (-28.4 ± 5.8‰) acids showed smaller δ13C values than TC. Based on comparisons of δ13C values of TC in Chennai aerosols to those (-24.7 ± 2.2‰) found in unburned cow-dung samples collected from Chennai and isotopic signatures of the particles emitted from point sources, we found that biofuel/biomass burning are the major sources of carbonaceous aerosols in South and Southeast Asia. The decrease in δ13C values of C9 diacid by about 5‰ from winter to summer suggests that tropical plant emissions also significantly contribute to organic aerosol in this region. Significant increase in δ13C values from C4 to C2 diacids in Chennai aerosols could be attributed for their photochemical processing in the tropical atmosphere during long-range transport from source regions.

  3. Seasonal variations and source identification of selected organic acids associated with PM10 in the coastal area of Southeastern China

    NASA Astrophysics Data System (ADS)

    Wu, Shui-Ping; Schwab, James; Liu, Bi-Lian; Li, Tsung-Chang; Yuan, Chung-Shin

    2015-03-01

    PM10 aerosols from the coastal area of Southeastern China were collected from April 2010 to March 2011 and were measured for C2-C10 dicarboxylic acids, phthalic acids (Ph) and five fatty acids (palmitic, stearic, oleic, linoleic and elaidic acids). For all sites and seasons, molecular distributions of diacids were always characterized by a predominance of oxalic acid (C2), with a relative abundance of 68-87%, followed by malonic acid (C3) and by either succinic acid (C4) or phthalic acid (Ph). This observed molecular composition was different from that in Chinese megacities where Ph was significantly higher than C3 and C4 diacids, which was likely due to the less intensive traffic emissions in the coastal area. Seasonal means of total diacids ranged between 394 and 547 ng m- 3 at the coastal urban sites and between 163 and 245 ng m- 3 at off-island sites. These levels were much lower than those reported in Chinese megacities (668-1568 ng m- 3) and slightly lower than those in Jeju Island, Korea (464-744 ng m- 3) but higher than those in marine and continental background locations. In all seasons, saturated fatty acids were significantly higher than unsaturated fatty acids due to their greater photochemical stabilities in the atmosphere. Most organic acids showed higher levels in spring and winter and lower levels in summer and fall, which was likely due to the influence of transport and meteorology. The diagnostic ratios of malonic acid to succinic acid (C3/C4), adipic acid to azelaic acid (C6/C9) and phthalic acid to azelaic acid (Ph/C9) were significantly higher in summer than in winter. These diagnostic ratios in the sampled ambient aerosols were completely different from those in primary emissions, suggesting the importance of photochemical production - especially in summer. The diurnal variations of diacids and fatty acid as well as the diagnostic ratios are associated with higher solar radiation and anthropogenic activities during the daytime. Principal

  4. Integrated engineering of β-oxidation reversal and ω-oxidation pathways for the synthesis of medium chain ω-functionalized carboxylic acids.

    PubMed

    Clomburg, James M; Blankschien, Matthew D; Vick, Jacob E; Chou, Alexander; Kim, Seohyoung; Gonzalez, Ramon

    2015-03-01

    An engineered reversal of the β-oxidation cycle was exploited to demonstrate its utility for the synthesis of medium chain (6-10-carbons) ω-hydroxyacids and dicarboxylic acids from glycerol as the only carbon source. A redesigned β-oxidation reversal facilitated the production of medium chain carboxylic acids, which were converted to ω-hydroxyacids and dicarboxylic acids by the action of an engineered ω-oxidation pathway. The selection of a key thiolase (bktB) and thioesterase (ydiI) in combination with previously established core β-oxidation reversal enzymes, as well as the development of chromosomal expression systems for the independent control of pathway enzymes, enabled the generation of C6-C10 carboxylic acids and provided a platform for vector based independent expression of ω-functionalization enzymes. Using this approach, the expression of the Pseudomonas putida alkane monooxygenase system, encoded by alkBGT, in combination with all β-oxidation reversal enzymes resulted in the production of 6-hydroxyhexanoic acid, 8-hydroxyoctanoic acid, and 10-hydroxydecanoic acid. Following identification and characterization of potential alcohol and aldehyde dehydrogenases, chnD and chnE from Acinetobacter sp. strain SE19 were expressed in conjunction with alkBGT to demonstrate the synthesis of the C6-C10 dicarboxylic acids, adipic acid, suberic acid, and sebacic acid. The potential of a β-oxidation cycle with ω-oxidation termination pathways was further demonstrated through the production of greater than 0.8 g/L C6-C10 ω-hydroxyacids or about 0.5 g/L dicarboxylic acids of the same chain lengths from glycerol (an unrelated carbon source) using minimal media.

  5. Hydrazide functionalized core-shell magnetic nanocomposites for highly specific enrichment of N-glycopeptides.

    PubMed

    Liu, Liting; Yu, Meng; Zhang, Ying; Wang, Changchun; Lu, Haojie

    2014-05-28

    In view of the biological significance of glycosylation for human health, profiling of glycoproteome from complex biological samples is highly inclined toward the discovery of disease biomarkers and clinical diagnosis. Nevertheless, because of the existence of glycopeptides at relatively low abundances compared with nonglycosylated peptides and glycan microheterogeneity, glycopeptides need to be highly selectively enriched from complex biological samples for mass spectrometry analysis. Herein, a new type of hydrazide functionalized core-shell magnetic nanocomposite has been synthesized for highly specific enrichment of N-glycopeptides. The nanocomposites with both the magnetic core and the polymer shell hanging high density of hydrazide groups were prepared by first functionalization of the magnetic core with polymethacrylic acid by reflux precipitation polymerization to obtain the Fe3O4@poly(methacrylic acid) (Fe3O4@PMAA) and then modification of the surface of Fe3O4@PMAA with adipic acid dihydrazide (ADH) to obtain Fe3O4@poly(methacrylic hydrazide) (Fe3O4@PMAH). The abundant hydrazide groups toward highly specific enrichment of glycopeptides and the magnetic core make it suitable for large-scale, high-throughput, and automated sample processing. In addition, the hydrophilic polymer surface can provide low nonspecific adsorption of other peptides. Compared to commercially available hydrazide resin, Fe3O4@PMAH improved more than 5 times the signal-to-noise ratio of standard glycopeptides. Finally, this nanocomposite was applied in the profiling of N-glycoproteome from the colorectal cancer patient serum. In total, 175 unique glycopeptides and 181 glycosylation sites corresponding to 63 unique glycoproteins were identified in three repeated experiments, with the specificities of the enriched glycopeptides and corresponding glycoproteins of 69.6% and 80.9%, respectively. Because of all these attractive features, we believe that this novel hydrazide functionalized

  6. Joint effect of organic acids and inorganic salts on cloud droplet activation

    NASA Astrophysics Data System (ADS)

    Frosch, M.; Prisle, N. L.; Bilde, M.; Varga, Z.; Kiss, G.

    2011-04-01

    We have investigated CCN properties of internally mixed particles composed of one organic acid (oxalic acid dihydrate, succinic acid, adipic acid, citric acid, cis-pinonic acid, or Nordic reference fulvic acid) and one inorganic salt (sodium chloride or ammonium sulphate). Surface tension and water activity of aqueous model solutions with concentrations relevant for CCN activation were measured using a tensiometer and osmometry, respectively. The measurements were used to calculate Köhler curves and critical supersaturations, which were compared to measured critical supersaturations of particles with the same chemical compositions, determined with a cloud condensation nucleus counter. Surfactant surface partitioning was not accounted for. For the aqueous solutions containing cis-pinonic acid and fulvic acid, a depression of surface tension was observed, but for the remaining solutions the effect on surface tension was negligible at concentrations relevant for cloud droplet activation. The surface tension depression of aqueous solutions containing both organic acid and inorganic salt was approximately the same as or smaller than that of aqueous solutions containing the same mass of the corresponding pure organic acids. Water activity was found to be highly dependent on the type and amount of inorganic salt. Sodium chloride was able to decrease water activity more than ammonium sulphate and both inorganic salts are predicted to have a smaller Raoult term than the studied organic acids. Increasing the mass ratio of the inorganic salt led to a decrease in water activity. Water activity measurements were compared to results from the E-AIM model and values estimated from both constant and variable van't Hoff factors. The correspondence between measurements and estimates was overall good, except for highly concentrated solutions. Critical supersaturations calculated with Köhler theory based on measured water activity and surface tension, but not accounting for surface

  7. Self-assembly in solvates of 2,4-diamino-6-(4-methyl- phenyl)-1,3,5-triazine and in its molecular adducts with some aliphatic dicarboxylic acids

    NASA Astrophysics Data System (ADS)

    Nandy, Purnendu; Nayak, Amrita; Biswas, Sharmita Nandy; Pedireddi, V. R.

    2016-03-01

    Solid state structures of 2,4-diamino-6-(4-methylphenyl)-1,3,5-triazine, 1, in the form of methanol and dimethylsulfoxide (DMSO) solvates, as well as supramolecular assemblies of 1 with various aliphatic dicarboxylic acids, oxalic (a), malonic (b), succinic (c), glutaric (d) and adipic (e) have been reported. Analysis of the assemblies has been carried out by single crystal X-ray diffraction and thermal methods. Triazine 1 yields anhydrous molecular adducts with acids a-d, upon co-crystallization either from CH3OH and DMSO solvents. However acid e gives anhydrous adduct from DMSO solvent, while it gives a methanol adduct from CH3OH. Structure determination reveals that molecular adducts 1a, 1d and 1e are in a 2:1 ratio of 1 and the corresponding acid. However the ratio is 1:1, in 1b, perhaps due to the involvement of one of the acid groups in the intramolecular hydrogen bonding and in adduct 1c the ratio observed is 3:2. Structural features in all these assemblies have been rationalised in terms of various recognition patterns formed between the acceptor and donor groups. A noteworthy feature is that -COOH groups in acid a establish interaction with 1 through amino groups, while such interactions are observed to be through hetero -N atoms in case of the acids b-e.

  8. Obeticholic Acid

    MedlinePlus

    Obeticholic acid is used alone or in combination with ursodiol (Actigall, Urso) to treat primary biliary cholangitis (PBC; a ... were not treated successfully with ursodiol alone. Obeticholic acid is in a class of medications called farnesoid ...

  9. Aminocaproic Acid

    MedlinePlus

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  10. Acid mucopolysaccharides

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003368.htm Acid mucopolysaccharides To use the sharing features on this page, please enable JavaScript. Acid mucopolysaccharides is a test that measures the amount ...

  11. Aristolochic Acids

    MedlinePlus

    ... Sciences NIH-HHS www.niehs.nih.gov Aristolochic Acids Key Points Report on Carcinogens Status Known to be human carcinogens Aristolochia Clematitis Aristolochic Acids n Known human carcinogens n Found in certain ...

  12. Ascorbic Acid

    MedlinePlus

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

  13. Ethacrynic Acid

    MedlinePlus

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  14. Amino acids

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  15. Valproic Acid

    MedlinePlus

    Valproic acid is used alone or with other medications to treat certain types of seizures. Valproic acid is also used to treat mania (episodes of ... to relieve headaches that have already begun. Valproic acid is in a class of medications called anticonvulsants. ...

  16. Ameliorative Effect of Curcumin-Encapsulated Hyaluronic Acid–PLA Nanoparticles on Thioacetamide-Induced Murine Hepatic Fibrosis

    PubMed Central

    Chen, Yu-Nong; Hsu, Shih-Lan; Liao, Ming-Yuan; Liu, Yi-Ting; Lai, Chien-Hung; Chen, Ji-Feng; Nguyen, Mai-Huong Thi; Su, Yung-Hsiang; Chen, Shang-Ting; Wu, Li-Chen

    2016-01-01

    In this study, we developed curcumin-encapsulated hyaluronic acid–polylactide nanoparticles (CEHPNPs) to be used for liver fibrosis amelioration. CD44, the hyaluronic acid (HA) receptor, is upregulated on the surface of cancer cells and on activated hepatic stellate cells (aHSCs) rather than normal cells. CEHPNPs could bind to CD44 and be internalized effectively through endocytosis to release curcumin, a poor water-soluble liver protective agent. Thus, CEHPNPs were potentially not only improving drug efficiency, but also targeting aHSCs. HA and polylactide (PLA) were crosslinked by adipic acid dihydrazide (ADH). The synthesis of HA–PLA was monitored by Fourier-transform infrared (FTIR) and Nuclear Magnetic Resonance (NMR). The average particle size was approximately 60–70 nm as determined by dynamic light scattering (DLS) and scanning electron microscope (SEM). Zeta potential was around −30 mV, which suggested a good stability of the particles. This drug delivery system induced significant aHSC cell death without affecting quiescent HSCs, hepatic epithelial, and parenchymal cells. This system reduced drug dosage without sacrificing therapeutic efficacy. The cytotoxicity IC50 (inhibitory concentration at 50%) value of CEHPNPs was approximately 1/30 to that of the free drug treated group in vitro. Additionally, the therapeutic effects of CEHPNPs were as effective as the group treated with the same curcumin dose intensity in vivo. CEHPNPs significantly reduced serum aspartate transaminase/alanine transaminase (ALT/AST) significantly, and attenuated tissue collagen production and cell proliferation as revealed by liver biopsy. Conclusively, the advantages of superior biosafety and satisfactory therapeutic effect mean that CEHPNPs hold great potential for treating hepatic fibrosis. PMID:28029125

  17. Investigation and characterization of oxidized cellulose and cellulose nanofiber films

    NASA Astrophysics Data System (ADS)

    Yang, Han

    Over the last two decades, a large amount of research has focused on natural cellulose fibers, since they are "green" and renewable raw materials. Recently, nanomaterials science has attracted wide attention due to the large surface area and unique properties of nanoparticles. Cellulose certainly is becoming an important material in nanomaterials science, with the increasing demand of environmentally friendly materials. In this work, a novel method of preparing cellulose nanofibers (CNF) is being presented. This method contains up to three oxidation steps: periodate, chlorite and TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxyl) oxidation. The first two oxidation steps are investigated in the first part of this work. Cellulose pulp was oxidized to various extents by a two step-oxidation with sodium periodate, followed by sodium chlorite. The oxidized products can be separated into three different fractions. The mass ratio and charge content of each fraction were determined. The morphology, size distribution and crystallinity index of each fraction were measured by AFM, DLS and XRD, respectively. In the second part of this work, CNF were prepared and modified under various conditions, including (1) the introduction of various amounts of aldehyde groups onto CNF by periodate oxidation; (2) the carboxyl groups in sodium form on CNF were converted to acid form by treated with an acid type ion-exchange resin; (3) CNF were cross-linked in two different ways by employing adipic dihydrazide (ADH) as cross-linker and water-soluble 1-ethyl-3-[3-(dimethylaminopropyl)] carbodiimide (EDC) as carboxyl-activating agent. Films were fabricated with these modified CNF suspensions by vacuum filtration. The optical, mechanical and thermo-stability properties of these films were investigated by UV-visible spectrometry, tensile test and thermogravimetric analysis (TGA). Water vapor transmission rates (WVTR) and water contact angle (WCA) of these films were also studied.

  18. Multifunctional pH-sensitive magnetic nanoparticles for simultaneous imaging, sensing and targeted intracellular anticancer drug delivery

    NASA Astrophysics Data System (ADS)

    Banerjee, Shashwat S.; Chen, Dong-Hwang

    2008-12-01

    A novel multifunctional magnetic nanocarrier was fabricated for synchronous cancer therapy and sensing. The nanocarrier, programed to display a response to environmental stimuli (pH value), was synthesized by coupling doxorubicin (DOX) to adipic dihydrazide-grafted gum arabic modified magnetic nanoparticles (ADH-GAMNP) via the hydrolytically degradable pH-sensitive hydrazone bond. The resultant nanocarrier, DOX-ADH-GAMNP, had a mean diameter of 13.8 nm and the amount of DOX coupled was about 6.52 mg g-1. Also, it exhibited pH triggered release of DOX in an acidic environment (pH 5.0) but was relatively stable at physiological pH (pH 7.4). Furthermore, both GAMNP and DOX were found to possess fluorescence properties when excited in the near-infrared region due to the two-photon absorption mechanism. The coupling of DOX to GAMNP resulted in a reversible self-quenching of fluorescence through the fluorescence resonant energy transfer (FRET) between the donor GAMNP and acceptor DOX. The release of DOX from DOX-ADH-GAMNP when exposed to acidic media indicated the recovery of fluorescence from both GAMNP and DOX. The change in the fluorescence intensity of DOX-ADH-GAMNP on the release of DOX can act as a potential sensor to sense the delivery of the drug. The analysis of zeta potential and plasmon absorbance in different pH conditions also confirmed the pH sensitivity of the product. This multifunctional nanocarrier is a significant breakthrough in developing a drug delivery vehicle that combines drug targeting as well as sensing and therapy at the same time.

  19. Multifunctional pH-sensitive magnetic nanoparticles for simultaneous imaging, sensing and targeted intracellular anticancer drug delivery.

    PubMed

    Banerjee, Shashwat S; Chen, Dong-Hwang

    2008-12-17

    A novel multifunctional magnetic nanocarrier was fabricated for synchronous cancer therapy and sensing. The nanocarrier, programed to display a response to environmental stimuli (pH value), was synthesized by coupling doxorubicin (DOX) to adipic dihydrazide-grafted gum arabic modified magnetic nanoparticles (ADH-GAMNP) via the hydrolytically degradable pH-sensitive hydrazone bond. The resultant nanocarrier, DOX-ADH-GAMNP, had a mean diameter of 13.8 nm and the amount of DOX coupled was about 6.52 mg g(-1). Also, it exhibited pH triggered release of DOX in an acidic environment (pH 5.0) but was relatively stable at physiological pH (pH 7.4). Furthermore, both GAMNP and DOX were found to possess fluorescence properties when excited in the near-infrared region due to the two-photon absorption mechanism. The coupling of DOX to GAMNP resulted in a reversible self-quenching of fluorescence through the fluorescence resonant energy transfer (FRET) between the donor GAMNP and acceptor DOX. The release of DOX from DOX-ADH-GAMNP when exposed to acidic media indicated the recovery of fluorescence from both GAMNP and DOX. The change in the fluorescence intensity of DOX-ADH-GAMNP on the release of DOX can act as a potential sensor to sense the delivery of the drug. The analysis of zeta potential and plasmon absorbance in different pH conditions also confirmed the pH sensitivity of the product. This multifunctional nanocarrier is a significant breakthrough in developing a drug delivery vehicle that combines drug targeting as well as sensing and therapy at the same time.

  20. Fatty acids - trans fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The data supporting a negative effect of dietary trans fatty acids on cardiovascular disease risk is consistent. The primary dietary sources of trans fatty acids include partially hydrogenated fat and rudiment fat. The adverse effect of trans fatty acids on plasma lipoprotein profiles is consisten...

  1. Joint effect of organic acids and inorganic salts on cloud droplet activation

    NASA Astrophysics Data System (ADS)

    Frosch, M.; Prisle, N. L.; Bilde, M.; Varga, Z.; Kiss, G.

    2010-07-01

    We have investigated CCN properties of internally mixed particles composed of one organic acid (oxalic acid, succinic acid, adipic acid, citric acid, cis-pinonic acid, or nordic reference fulvic acid) and one inorganic salt (sodium chloride or ammonium sulphate). Surface tension and water activity of aqueous model solutions with concentrations relevant for CCN activation were measured using a tensiometer and osmometry, respectively. The measurements were used to calculate Köhler curves, which were compared to measured critical supersaturations of particles with the same chemical compositions, determined with a cloud condensation nucleus counter. Surfactant surface partitioning was not accounted for. For the mixtures containing cis-pinonic acid or fulvic acid, a depression of surface tension was observed, but for the remaining mixtures the effect on surface tension was negligle at concentrations relevant for cloud droplet activation, and water activity was the more significant term in the Köhler equation. The surface tension depression of aqueous solutions containing both organic acid and inorganic salt was approximately the same as or smaller than that of aqueous solutions containing the same mass of the corresponding pure organic acids. Water activity was found to be highly dependent on the type and amount of inorganic salt. Sodium chloride was able to decrease water activity more than ammonium sulphate and both inorganic compounds had a higher effect on water activity than the studied organic acids, and increasing the mass ratio of the inorganic compound led to a decrease in water activity. Water activity measurements were compared to results from the E-AIM model and values estimated from both constant and variable van't Hoff factors to evaluate the performance of these approaches. The correspondence between measuments and estimates was overall good, except for highly concentrated solutions. Critical supersaturations calculated with Köhler theory based on

  2. Physiological function of the Pseudomonas putida PpG6 (Pseudomonas oleovorans) alkane hydroxylase: monoterminal oxidation of alkanes and fatty acids.

    PubMed Central

    Nieder, M; Shapiro, J

    1975-01-01

    Pseudomonas putida PpG6 is able to utilize purified n-alkanes of six to ten carbon atoms for growth. It can also grow on the primary terminal oxidation products of these alkanes and on 1-dodecanol but not on the corresponding 2-ketones or 1,6-hexanediol, adipic acid, or pimelic acid. Revertible point mutants can be isolated which have simultaneously lost the ability to grow on all five n-alkane growth substrates but which can still grow on octanol or nonanol. An acetate-negative mutant defective in isocitrate lysase activity is unable to grow on even-numbered alkanes and fatty acids. Analysis of double mutants defective in acetate and propionate or in acetate and glutarate metabolism shows that alkane carbon is assimilated only via acetyl-coenzyme A and propionyl-coenzyme A. These results support the following conclusions: (i) The n-alkane growth specificity of P. putida PpG6 is due to the substrate specificity of whole-cell alkane hydroxylation; (ii) there is a single alkane hydroxylase enzyme complex; (iii) the physiological role of this complex is to initiate the monoterminal oxidation of alkane chains; and (iv) straight-chain fatty acids from butyric through nonanoic are degraded exclusively by beta-oxidation from the carboxyl end of the molecule. PMID:804473

  3. Cryo-transmission electron microscopy imaging of the morphology of submicrometer aerosol containing organic acids and ammonium sulfate.

    PubMed

    Veghte, Daniel P; Bittner, Danielle Rae; Freedman, Miriam Arak

    2014-03-04

    The effects of aerosol particles on heterogeneous atmospheric chemistry and climate are determined in part by the internal arrangement of compounds within the particles. To characterize the morphology of internally mixed aerosol particles in the accumulation mode size regime, we have used cryo-transmission electron microscopy to investigate the phase separation behavior of dry, submicrometer particles composed of ammonium sulfate mixed with carboxylic acids (adipic, azelaic, citric, glutaric, malonic, pimelic, suberic, and succinic acid). Determining the morphology of dry particles is important for understanding laboratory studies of aerosol optical properties, reactivity, and cloud condensation nucleus activity, results from field instruments where aerosol particles are dried prior to analysis, and atmospheric processes like deposition mode heterogeneous ice nucleation that occur on dried particles. We observe homogeneous morphologies for highly soluble organic compounds. For organic compounds with limited aqueous solubility, partially engulfed structures are observed. At intermediate aqueous solubilities, small particles are homogeneous and larger particles are partially engulfed. Results are compared to previous studies of liquid-liquid phase separation in supermicrometer particles and the impact of these dry particle morphologies on aerosol-climate interactions are discussed.

  4. Acid rain

    SciTech Connect

    Elsworth, S.

    1985-01-01

    This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

  5. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications.

  6. Acid rain

    SciTech Connect

    Sweet, W.

    1980-06-20

    Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

  7. Vibrio cholerae O139 Conjugate Vaccines: Synthesis and Immunogenicity of V. cholerae O139 Capsular Polysaccharide Conjugates with Recombinant Diphtheria Toxin Mutant in Mice

    PubMed Central

    Kossaczka, Zuzana; Shiloach, Joseph; Johnson, Virginia; Taylor, David N.; Finkelstein, Richard A.; Robbins, John B.; Szu, Shousun C.

    2000-01-01

    Epidemiologic and experimental data provide evidence that a critical level of serum immunoglobulin G (IgG) antibodies to the surface polysaccharide of Vibrio cholerae O1 (lipopolysaccharide) and of Vibrio cholerae O139 (capsular polysaccharide [CPS]) is associated with immunity to the homologous pathogen. The immunogenicity of polysaccharides, especially in infants, may be enhanced by their covalent attachment to proteins (conjugates). Two synthetic schemes, involving 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and 1-cyano-4-dimethylaminopyridinium tetrafluoroborate (CDAP) as activating agents, were adapted to prepare four conjugates of V. cholerae O139 CPS with the recombinant diphtheria toxin mutant, CRMH21G. Adipic acid dihydrazide was used as a linker. When injected subcutaneously into young outbred mice by a clinically relevant dose and schedule, these conjugates elicited serum CPS antibodies of the IgG and IgM classes with vibriocidal activity to strains of capsulated V. cholerae O139. Treatment of these sera with 2-mercaptoethanol (2-ME) reduced, but did not eliminate, their vibriocidal activity. These results indicate that the conjugates elicited IgG with vibriocidal activity. Conjugates also elicited high levels of serum diphtheria toxin IgG. Convalescent sera from 20 cholera patients infected with V. cholerae O139 had vibriocidal titers ranging from 100 to 3,200: absorption with the CPS reduced the vibriocidal titer of all sera to ≤50. Treatment with 2-ME reduced the titers of 17 of 20 patients to ≤50. These data show that, like infection with V. cholerae O1, infection with V. cholerae O139 induces vibriocidal antibodies specific to the surface polysaccharide of this bacterium (CPS) that are mostly of IgM class. Based on these data, clinical trials with the V. cholerae O139 CPS conjugates with recombinant diphtheria toxin are planned. PMID:10948122

  8. Preparation, Immunogenicity, and Protective Efficacy, in a Murine Model, of a Conjugate Vaccine Composed of the Polysaccharide Moiety of the Lipopolysaccharide of Vibrio cholerae O139 Bound to Tetanus Toxoid

    PubMed Central

    Boutonnier, Alain; Villeneuve, Sylvain; Nato, Farida; Dassy, Bruno; Fournier, Jean-Michel

    2001-01-01

    The epidemic and pandemic potential of Vibrio cholerae O139 is such that a vaccine against this newly emerged serogroup of V. cholerae is required. A conjugate made of the polysaccharide moiety (O-specific polysaccharide plus core) of the lipopolysaccharide (LPS) of V. cholerae O139 (pmLPS) was prepared by derivatization of the pmLPS with adipic acid dihydrazide and coupling to tetanus toxoid (TT) by carbodiimide-mediated condensation. The immunologic properties of the conjugate were tested using BALB/c mice injected subcutaneously three times at 2 weeks interval and then a fourth time 4 weeks later. Mice were bled 7 days after each injection and then once each month for the following 6 months. LPS and TT antibody levels were determined by enzyme-linked immunosorbent assay using immunoplates coated with either O139 LPS or TT. Both pmLPS and pmLPS-TT conjugate elicited low levels of immunoglobulin M (IgM), peaking 5 weeks after the first immunization. The conjugate elicited high levels of IgG antibodies, peaking 3 months after the first immunization and declining slowly during the following 5 months. TT alone, or as a component of conjugate, induced mostly IgG antibodies. Antibodies elicited by the conjugate recognized both capsular polysaccharide and LPS from V. cholerae O139 and were vibriocidal. They were also protective in the neonatal mouse model of cholera infection. The conjugation of the O139 pmLPS, therefore, enhanced its immunogenicity and conferred T-dependent properties to this polysaccharide. PMID:11292781

  9. Preparation and testing of a Haemophilus influenzae Type b/Hepatitis B surface antigen conjugate vaccine.

    PubMed

    An, So Jung; Woo, Joo Sung; Chae, Myung Hwa; Kothari, Sudeep; Carbis, Rodney

    2015-03-24

    The majority of conjugate vaccines focus on inducing an antibody response to the polysaccharide antigen and the carrier protein is present primarily to induce a T-cell dependent response. In this study conjugates consisting of poly(ribosylribitolphosphate) (PRP) purified from Haemophilus influenzae Type b bound to Hepatitis B virus surface antigen (HBsAg) virus like particles were prepared with the aim of inducing an antibody response to not only the PRP but also the HBsAg. A conjugate consisting of PRP bound to HBsAg via an adipic acid dihydrazide (ADH) spacer induced strong IgG antibodies to both the PRP and HBsAg. When conjugation was performed without the ADH spacer the induction of an anti-PRP response was equivalent to that seen by conjugate with the ADH spacer, however, a negligible anti-HBsAg response was induced. For comparison, PRP was conjugated to diphtheria toxoid (DT) and Vi polysaccharide purified from Salmonella Typhi conjugated to HBsAg both using an ADH spacer. The PRPAH-DT conjugate induced strong anti-PRP and anti-DT responses, the Vi-AHHBsAg conjugate induced a good anti-HBsAg response but not as strong as that induced by the PRPAH-HBsAg conjugate. This study demonstrated that in mice it was possible to induce robust antibody responses to both polysaccharide and carrier protein provided the conjugate has certain physico-chemical properties. A PRPAH-HBsAg conjugate with the capacity to induce anti-PRP and anti-HBsAg responses could be incorporated into a multivalent pediatric vaccine and simplify formulation of such a vaccine.

  10. Study of supramolecular frameworks having aliphatic dicarboxylic acids, N,N‧-bis(salicyl)ethylenediamine and N,N‧-bis(salicyl)butylenediamine

    NASA Astrophysics Data System (ADS)

    Goel, Nidhi; Kumar, Naresh

    2014-08-01

    The reaction of bases (L1 and L2) (where L1 = N,N‧-bis(salicyl)ethylenediamine, L2 = N,N‧-bis(salicyl)butylenediamine) with dicarboxylic acids [adipic acid (1,6-Hexanedioic acid, AA), pimelic acid (1,7-Heptanedioic acid, PA) and suberic acid (1,8-Octanedioic acid, SUA] yielded the corresponding six new ionic salts viz., [1/2L1H+ṡ1/2AA-ṡ1/2AA] (1), [2 × 1/2L1H+ṡPA2-ṡCHCl3] (2) [1/2L1H+ṡ1/2SUA-] (3), [1/2L2H+ṡ1/2AA-ṡ2CH3OH] (4), [1/2L2H+ṡ1/2PA-] (5) and [1/2L2H+ṡ1/2SUA-] (6), respectively. Theses salts were characterized by elemental analysis, FT-IR, NMR, X-ray crystallography, and theoretically by means of Gaussian 09. The X-ray crystallographic studies revealed that the proton transfer occurred from acid to base. It also demonstrated that different type of hydrogen bond interactions between cations and anions were responsible for the supramolecular frameworks. The optimized structures of these salts were calculated in terms of the density functional theory. The curve fitting analysis between experimental and simulated data of structural parameters was done, and found statistically close. The orientation of molecules was remained same in both the gas and solid phases. The thermal studies of these salts were investigated by TG-DTG.

  11. Acid fog

    SciTech Connect

    Hileman, B.

    1983-03-01

    Fog in areas of southern California previously thought to be pollution-free has been shown to have a pH as low as 1.69. It has been found to be most acidic after smoggy days, suggesting that it forms on the aerosol associated with the previously exiting smog. Studies on Whiteface Mountain in the Adirondacks show that fog water is often 10 times as acidic as rainwater. As a result of their studies, California plans to spend $4 million on acid deposition research in the coming year. (JMT)

  12. Mefenamic Acid

    MedlinePlus

    ... as mefenamic acid may cause ulcers, bleeding, or holes in the stomach or intestine. These problems may ... like coffee grounds, blood in the stool, or black and tarry stools.Keep all appointments with your ...

  13. Acid Rain

    MedlinePlus

    ... EPA Is Doing Acid Rain Program Cross-State Air Pollution Rule Progress Reports Educational Resources Kid's Site for ... Monitoring National Atmospheric Deposition Program (NADP) Exit Interstate Air Pollution Transport Contact Us to ask a question, provide ...

  14. Folic Acid

    MedlinePlus

    ... folic acid can hide signs that you lack vitamin B12, which can cause nerve damage. 10 Do I ... Rosenberg, I.H., et al. (2007). Folate and vitamin B12 status in relation to anemia, macrocytosis and cognitive ...

  15. Acid Precipitation

    ERIC Educational Resources Information Center

    Likens, Gene E.

    1976-01-01

    Discusses the fact that the acidity of rain and snow falling on parts of the U.S. and Europe has been rising. The reasons are still not entirely clear and the consequences have yet to be well evaluated. (MLH)

  16. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  17. Organosulfates and organic acids in Arctic aerosols: speciation, annual variation and concentration levels

    NASA Astrophysics Data System (ADS)

    Hansen, A. M. K.; Kristensen, K.; Nguyen, Q. T.; Zare, A.; Cozzi, F.; Nøjgaard, J. K.; Skov, H.; Brandt, J.; Christensen, J. H.; Ström, J.; Tunved, P.; Krejci, R.; Glasius, M.

    2014-02-01

    Sources, composition and occurrence of secondary organic aerosols (SOA) in the Arctic were investigated at Zeppelin Mountain, Svalbard, and Station Nord, northeast Greenland, during the full annual cycle of 2008 and 2010 respectively. We focused on the speciation of three types of SOA tracers: organic acids, organosulfates and nitrooxy organosulfates from both anthropogenic and biogenic precursors, here presenting organosulfate concentrations and compositions during a full annual cycle and chemical speciation of organosulfates in Arctic aerosols for the first time. Aerosol samples were analysed using High Performance Liquid Chromatography coupled to a quadrupole Time-of-Flight mass spectrometer (HPLC-q-TOF-MS). A total of 11 organic acids (terpenylic acid, benzoic acid, phthalic acid, pinic acid, suberic acid, azelaic acid, adipic acid, pimelic acid, pinonic acid, diaterpenylic acid acetate (DTAA) and 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA)), 12 organosulfates and one nitrooxy organosulfate were identified at the two sites. Six out of the 12 organosulfates are reported for the first time. Concentrations of organosulfates follow a distinct annual pattern at Station Nord, where high concentration were observed in late winter and early spring, with a mean total concentration of 47 (±14) ng m-3, accounting for 7 (±2)% of total organic matter, contrary to a considerably lower organosulfate mean concentration of 2 (±3) ng m-3 (accounting for 1 (±1)% of total organic matter) observed during the rest of the year. The organic acids followed the same temporal trend as the organosulfates at Station Nord; however the variations in organic acid concentrations were less pronounced, with a total mean organic acid concentration of 11.5 (±4) ng m-3 (accounting for 1.7 (±0.6)% of total organic matter) in late winter and early spring, and 2.2 (±1) ng m-3 (accounting for 0.9 (±0.4)% of total organic matter) during the rest of the year. At Zeppelin Mountain

  18. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.

    1993-01-01

    Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

  19. Acid Rain

    USGS Publications Warehouse

    Bricker, Owen P.; Rice, Karen C.; Dietrich, W.E.; Sposito, Garrison

    1997-01-01

    Acid deposition, or acid rain as it is more commonly referred to, has become a widely publicized environmental issue in the U.S. over the past decade. The term usually conjures up images of fish kills, dying forests, "dead" lakes, and damage to monuments and other historic artifacts. The primary cause of acid deposition is emission of S02 and NOx to the atmosphere during the combustion of fossil fuels. Oxidation of these compounds in the atmosphere forms strong acids - H2SO4 and HNO3 - which are returned to the Earth in rain, snow, fog, cloud water, and as dry deposition.Although acid deposition has only recently been recognized as an environmental problem in the U.S., it is not a new phenomenon (Cogbill & Likens 1974). As early as the middle of the 17th century in England, the deleterious effects of industrial emissions on plants, animals, and humans, and the atmospheric transport of pollutants between England and France had become issues of concern (Evelyn 1661, Graunt 1662). It is interesting that well over three hundred years ago in England, recommendations were made to move industry outside of towns and build higher chimneys to spread the pollution into "distant parts." Increasing the height of smokestacks has helped alleviate local problems, but has exacerbated others. In the U.S. the height of the tallest smokestack has more than doubled, and the average height of smokestacks has tripled since the 1950s (Patrick et al 1981). This trend occurred in most industrialized nations during the 20th century and has had the effect of transforming acid rain from a local urban problem into a problem of global scale.

  20. 40 CFR 98.53 - Calculating GHG emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (CONTINUED) MANDATORY GREENHOUSE GAS REPORTING Adipic Acid Production § 98.53 Calculating GHG emissions. (a) You must determine annual N2O emissions from adipic acid production according to paragraphs (a)(1) or... must conduct the test on the vent stream from the nitric acid oxidation step of the process,...

  1. Salicylic acids

    PubMed Central

    Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

    2012-01-01

    Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

  2. Topological aspects of lanthanide–adipate–aqua compounds: Close packed and open framework structures

    SciTech Connect

    Chowdhuri, Durga Sankar; Kumar Jana, Swapan; Hazari, Debdoot; Zangrando, Ennio; Dalai, Sudipta

    2013-07-15

    A search in the Cambridge Structural Database (CSD) for lanthanide complexes with adipate [OOC(CH{sub 2}){sub 4}COO]{sup 2−} and aqua ligands retrieved a fair number of compounds. To this dataset a new lanthanum metal–organic framework, ([La{sub 2}(adip){sub 3}(H{sub 2}O){sub 2}] (1) (adipH{sub 2}=adipic acid), synthesised and structurally characterized in these labs, was included. The crystal structures of these coordination polymers, of general formulation [Ln{sub 2}(adip){sub 3}(H{sub 2}O){sub x}], exhibit a variety of topologies and dimensionality, which were clustered in different classes and described in detail. It was explored that the majority of these evidences the presence of metal chains or dinuclear Ln{sub 2} entities (separated in both cases by 4.0–4.8 Å), where lanthanide ions are differently connected by carboxylate groups with chelating or oxygen-bridging mode. The different amount of coordinated water molecules appear to affect the solid state networks. Moreover the crystal packing of these compounds shows peculiar aspects and examples were reported in the literature where the long alkyl chain of adipate connectors give rise to interpenetrated structures, or to porous material where lattice water or neutral larger molecules are clathrated. - Graphical abstract: A survey of structures and topologies of lanthanide adipate compounds is presented. A newly synthesized lanthanium adipate complex ([La{sub 2}(adip){sub 3}(H{sub 2}O){sub 2}] (adipH{sub 2}=adipic acid) is also reported. - Highlights: • The use of lanthanide and adipic acid demonstrate the possibility to construct coordination polymer of different dimensionality. • The number of coordination and adipate conformation influence the different topologies. • The ionic radii of the rare earth cations seem also to affect the architecture observed.

  3. Solder Flux Residues and Humidity-Related Failures in Electronics: Relative Effects of Weak Organic Acids Used in No-Clean Flux Systems

    NASA Astrophysics Data System (ADS)

    Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

    2015-04-01

    This paper presents the results of humidity testing of weak organic acids (WOAs), namely adipic, succinic, glutaric, dl-malic, and palmitic acids, which are commonly used as activators in no-clean solder fluxes. The study was performed under humidity conditions varying from 60% relative humidity (RH) to ˜99%RH at 25°C. The following parameters were used for characterization of WOAs: mass gain due to water adsorption and deliquescence of the WOA (by quartz crystal microbalance), resistivity of the water layer formed on the printed circuit board (by impedance spectroscopy), and leakage current measured using the surface insulation resistance pattern in the potential range from 0 V to 10 V. The combined results indicate the importance of the WOA chemical structure for the water adsorption and therefore conductive water layer formation on the printed circuit board assembly (PCBA). A substantial increase of leakage currents and probability of electrochemical migration was observed at humidity levels above the RH corresponding to the deliquescence point of WOAs present as contaminants on the printed circuit boards. The results suggest that use of solder fluxes with WOAs having higher deliquescence point could improve the reliability of electronics operating under circumstances in which exposure to high humidity is likely to occur.

  4. Functionalised carboxylic acids in atmospheric particles: An annual cycle revealing seasonal trends and possible sources

    NASA Astrophysics Data System (ADS)

    Teich, Monique; van Pinxteren, Dominik; Herrmann, Hartmut

    2013-04-01

    Carboxylic acids represent a major fraction of the water soluble organic carbon (WSOC) in atmospheric particles. Among the particle phase carboxylic acids, straight-chain monocarboxylic acids (MCA) and dicarboxylic acids (DCA) with 2-10 carbon atoms have extensively been studied in the past. However, only a few studies exist dealing with functionalised carboxylic acids, i.e. having additional hydroxyl-, oxo- or nitro-groups. Regarding atmospheric chemistry, these functionalised carboxylic acids are of particular interest as they are supposed to be formed during atmospheric oxidation processes, e.g. through radical reactions. Therefore they can provide insights into the tropospheric multiphase chemistry. During this work 28 carboxylic acids (4 functionalised aliphatic MCAs, 5 aromatic MCAs, 3 nitroaromatic MCAs, 6 aliphatic DCAs, 6 functionalised aliphatic DCAs, 4 aromatic DCAs) were quantitatively determined in 256 filter samples taken at the rural research station Melpitz (Saxony, Germany) with a PM10 Digitel DHA-80 filter sampler. All samples were taken in 2010 covering a whole annual cycle. The resulting dataset was examined for a possible seasonal dependency of the acid concentrations. Furthermore the influence of the air mass origin on the acid concentrations was studied based on a simple two-sector classification (western or eastern sector) using a back trajectory analysis. Regarding the annual average, adipic acid was found to be the most abundant compound with a mean concentration of 7.8 ng m-3 followed by 4-oxopimelic acid with 6.1 ng m-3. The sum of all acid concentrations showed two maxima during the seasonal cycle; one in summer and one in winter, whereas the highest overall acid concentrations were found in summer. In general the target acids could be divided into two different groups, where one group has its maximum concentration in summer and the other group during winter. The first group contains all investigated aliphatic mono- and dicarboxylic

  5. Selenious acid

    Integrated Risk Information System (IRIS)

    Selenious acid ; CASRN 7783 - 00 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  6. Dichloroacetic acid

    Integrated Risk Information System (IRIS)

    EPA 635 / R - 03 / 007 www.epa.gov / iris TOXICOLOGICAL REVIEW OF DICHLOROACETIC ACID ( CAS No . 79 - 43 - 6 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) August 2003 U.S . Environmental Protection Agency Washington , DC DISCLAIMER This document has been revi

  7. Trichloroacetic acid

    Integrated Risk Information System (IRIS)

    EPA / 635 / R - 09 / 003F www.epa.gov / iris TOXICOLOGICAL REVIEW OF TRICHLOROACETIC ACID ( CAS No . 76 - 03 - 9 ) In Support of Summary Information on the Integrated Risk Information System ( IRIS ) September 2011 U.S . Environmental Protection Agency Washington , DC ii DISCLAIMER This document has

  8. Acid rain

    SciTech Connect

    Not Available

    1984-06-01

    An overview is presented of acid rain and the problems it causes to the environment worldwide. The acidification of lakes and streams is having a dramatic effect on aquatic life. Aluminum, present in virtually all forest soils, leaches out readily under acid conditions and interferes with the gills of all fish, some more seriously than others. There is evidence of major damage to forests in European countries. In the US, the most severe forest damage appears to be in New England, New York's Adirondacks, and the central Appalachians. This small region is part of a larger area of the Northeast and Canada that appears to have more acid rainfall than the rest of the country. It is downwind from major coal burning states, which produce about one quarter of US SO/sub 2/ emissions and one sixth of nitrogen oxide emissions. Uncertainties exist over the causes of forest damage and more research is needed before advocating expensive programs to reduce rain acidity. The President's current budget seeks an expansion of research funds from the current $30 million per year to $120 million.

  9. Benzoic acid

    Integrated Risk Information System (IRIS)

    Benzoic acid ; CASRN 65 - 85 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  10. Formic acid

    Integrated Risk Information System (IRIS)

    Formic acid ; CASRN 64 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  11. Acrylic acid

    Integrated Risk Information System (IRIS)

    Acrylic acid ( CASRN 79 - 10 - 7 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  12. Phosphoric acid

    Integrated Risk Information System (IRIS)

    Phosphoric acid ; CASRN 7664 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  13. Cacodylic acid

    Integrated Risk Information System (IRIS)

    Cacodylic acid ; CASRN 75 - 60 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  14. Analysis of phthalic acid diesters, monoester, and other plasticizers in polyvinyl chloride household products in Japan.

    PubMed

    Kawakami, Tsuyoshi; Isama, Kazuo; Matsuoka, Atsuko

    2011-01-01

    The aim of this study was to determine the concentrations of six phthalic acid diesters (PAEs) [di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), diisononyl phthalate (DINP), di-n-octyl phthalate (DNOP), and diisodecyl phthalate (DIDP)], two non-phthalic plasticizers [di(2-ethylhexyl) adipate (DEHA), 2,2,4-trimethyl-1,3-pentanediol diisobutylate (TMPDIB)], and mono 2-ethylhexyl phthalate(MEHP) in polyvinyl chloride (PVC) household products that children often places in their mouths and/or contact with their skin (41 products, 47 samples) in Japan. The detection frequencies of the studied compounds were as follows: DEHP (79 %), DINP-2 (13 %), DINP-1 (11 %), DBP (8.5 %), DEHA (8.5 %), DIDP (4.3 %), and DNOP (2.1 %). Concentrations of these compounds ranged from 0.021 % to 48 %. BBP and TMPDIB were not detected in the all samples. Most samples contained DEHP and DINP at high concentrations over 0.1 %. High concentrations of PAEs were detected in PVC household products that appear appealing to children and can possibly be licked and chewed by them. Di(2-ethylhexyl) terephtalete, diisononyl 1,2-cyclohexanedicarboxylic acid, acetyl tributyl citrate, and di(2-ethylhexyl) 4-cyclohexene-1,2-dicarboxylate used as substitute plasticizers were also detected in several samples. MEHP was present in 70 % of the samples, with concentrations ranging from trace amounts to 140 μg/g. The ratios of MEHP against DEHP were 6.2 × 10(-4) to 1.6 × 10(-1) %. MEHP in the household products investigated in this study was most probably an impurity in DEHP. The high concentrations of PAEs detected in products that children often place in their mouth reveal the importance of replacing plasticizers in common household products, and not just children's toys, with safer alternatives.

  15. Azelaic acid.

    PubMed

    Nazzaro-Porro, M

    1987-12-01

    This review is an update on the literature accumulated over the past 10 years following the original observation that azelaic acid, a naturally occurring and nontoxic C9 dicarboxylic acid, possesses significant biologic properties and a potential as a therapeutic agent. These studies have shown that azelaic acid is a reversible inhibitor of tyrosinase and other oxidoreductases in vitro and that it inhibits mitochondrial respiration. It can also inhibit anaerobic glycolysis. Both in vitro and in vivo it has an antimicrobial effect on both aerobic and anaerobic (Propionibacterium acnes) microorganisms. In tissue culture it exerts a dose- and time-dependent cytotoxic effect on malignant melanocytes, associated with mitochondrial damage and inhibition of deoxyribonucleic acid (DNA) synthesis. Tumoral cell lines not containing tyrosinase are equally affected. Normal cells in culture exposed to the same concentrations of the diacid that are toxic for tumoral cells are in general not damaged. Radioactive azelaic acid has been shown to penetrate tumoral cells at a higher level than normal cells of the corresponding line. Topically applied (a 20% cream), it has been shown to be of therapeutic value in skin disorders of different etiologies. Its beneficial effect on various forms of acne (comedogenic, papulopustular, nodulocystic) has been clearly demonstrated. Particularly important is its action on abnormal melanocytes, which has led to the possibility of obtaining good results on melasma and highly durable therapeutic responses on lentigo maligna. It is also capable of causing regression of cutaneous malignant melanoma, but its role in melanoma therapy remains to be investigated.(ABSTRACT TRUNCATED AT 250 WORDS)

  16. Hydroxycarboxylic acids and salts

    DOEpatents

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  17. Enhancing muconic acid production from glucose and lignin-derived aromatic compounds via increased protocatechuate decarboxylase activity

    SciTech Connect

    Johnson, Christopher W.; Salvachua, Davinia; Khanna, Payal; Smith, Holly; Peterson, Darren J.; Beckham, Gregg T.

    2016-04-22

    The conversion of biomass-derived sugars and aromatic molecules to cis,cis-muconic acid (referred to hereafter as muconic acid or muconate) has been of recent interest owing to its facile conversion to adipic acid, an important commodity chemical. Metabolic routes to produce muconate from both sugars and many lignin-derived aromatic compounds require the use of a decarboxylase to convert protocatechuate (PCA, 3,4-dihydroxybenzoate) to catechol (1,2-dihydroxybenzene), two central aromatic intermediates in this pathway. Several studies have identified the PCA decarboxylase as a metabolic bottleneck, causing an accumulation of PCA that subsequently reduces muconate production. A recent study showed that activity of the PCA decarboxylase is enhanced by co-expression of two genetically associated proteins, one of which likely produces a flavin-derived cofactor utilized by the decarboxylase. Using entirely genome-integrated gene expression, we have engineered Pseudomonas putida KT2440-derived strains to produce muconate from either aromatic molecules or sugars and demonstrate in both cases that co-expression of these decarboxylase associated proteins reduces PCA accumulation and enhances muconate production relative to strains expressing the PCA decarboxylase alone. In bioreactor experiments, co-expression increased the specific productivity (mg/g cells/h) of muconate from the aromatic lignin monomer p-coumarate by 50% and resulted in a titer of >15 g/L. In strains engineered to produce muconate from glucose, co-expression more than tripled the titer, yield, productivity, and specific productivity, with the best strain producing 4.92+/-0.48 g/L muconate. Furthermore, this study demonstrates that overcoming the PCA decarboxylase bottleneck can increase muconate yields from biomass-derived sugars and aromatic molecules in industrially relevant strains and cultivation conditions.

  18. Enhancing muconic acid production from glucose and lignin-derived aromatic compounds via increased protocatechuate decarboxylase activity

    DOE PAGES

    Johnson, Christopher W.; Salvachua, Davinia; Khanna, Payal; ...

    2016-04-22

    The conversion of biomass-derived sugars and aromatic molecules to cis,cis-muconic acid (referred to hereafter as muconic acid or muconate) has been of recent interest owing to its facile conversion to adipic acid, an important commodity chemical. Metabolic routes to produce muconate from both sugars and many lignin-derived aromatic compounds require the use of a decarboxylase to convert protocatechuate (PCA, 3,4-dihydroxybenzoate) to catechol (1,2-dihydroxybenzene), two central aromatic intermediates in this pathway. Several studies have identified the PCA decarboxylase as a metabolic bottleneck, causing an accumulation of PCA that subsequently reduces muconate production. A recent study showed that activity of the PCAmore » decarboxylase is enhanced by co-expression of two genetically associated proteins, one of which likely produces a flavin-derived cofactor utilized by the decarboxylase. Using entirely genome-integrated gene expression, we have engineered Pseudomonas putida KT2440-derived strains to produce muconate from either aromatic molecules or sugars and demonstrate in both cases that co-expression of these decarboxylase associated proteins reduces PCA accumulation and enhances muconate production relative to strains expressing the PCA decarboxylase alone. In bioreactor experiments, co-expression increased the specific productivity (mg/g cells/h) of muconate from the aromatic lignin monomer p-coumarate by 50% and resulted in a titer of >15 g/L. In strains engineered to produce muconate from glucose, co-expression more than tripled the titer, yield, productivity, and specific productivity, with the best strain producing 4.92+/-0.48 g/L muconate. Furthermore, this study demonstrates that overcoming the PCA decarboxylase bottleneck can increase muconate yields from biomass-derived sugars and aromatic molecules in industrially relevant strains and cultivation conditions.« less

  19. Acidic domains around nucleic acids.

    PubMed Central

    Lamm, G; Pack, G R

    1990-01-01

    The hydrogen ion concentration in the vicinity of DNA was mapped out within the Poisson-Boltzmann approximation. Experimental conditions were modeled by assuming Na-DNA to be solvated in a buffer solution containing 45 mM Tris and 3 mM Mg cations at pH 7.5. Three regions of high H+ concentration (greater than 10 microM) are predicted: one throughout the minor groove of DNA and two localized in the major groove near N7 of guanine and C5 of cytosine for a G.C base pair. These acidic domains correlate well with the observed covalent binding sites of benzo[a]pyrene epoxide (N2 of guanine) and of aflatoxin B1 epoxide (N7 of guanine), chemical carcinogens that presumably undergo acid catalysis to form highly reactive carbocations that ultimately bind to DNA. It is suggested that these regions of high H+ concentration may also be of concern in understanding interactions involving proteins and noncarcinogenic molecules with or near nucleic acids. PMID:2123348

  20. Thermomechanical Behavior of Monolithic SN-AG-CU Solder and Copper Fiber Reinforced Solders

    DTIC Science & Technology

    2005-09-01

    Aldrich # 20, 243-6) a white waxy solid, 1.6 parts of Adipic acid (Aldrich # A2635-7) a white solid powder, and 5.9 parts of polypropylene glycol, (PPG...step breaks down the Adipic acid precipitates into fine 25 micron particulates. Stirring was continued until a solution temperature of 30 oC was...

  1. Luminescence study of complexation of europium and dicarboxylic acids

    SciTech Connect

    Barthelemy, P.P.; Choppin, G.R. )

    1989-08-23

    Luminescence lifetime measurements of Eu(III) have been used to study the hdration of Eu(III) when complexed by alkane-dicarboxylate ligands. In its mono(malonate) complex, Eu(III) was found to have 2.3 fewer water molecules than the uncomplexed hydrated cation. In the formation of its 1:1 complexes with succinate, glutartate, and adipate, Eu(III) lost 1.5 molecules of water. When these dicarboxylate ligands reacted with the EuNTA complex to form the 1:1:1 ternary species, the malonate anion replaced 2.2, the succinate 1.5, and the glutarate and adipate 1.0 water molecules (all these values have ca. {plus minus}0.5 uncertainty). These data are discussed in terms of the effect on chelation of increased alkyl chain length. 13 refs., 4 figs., 5 tabs.

  2. Folic Acid and Pregnancy

    MedlinePlus

    ... Feeding Your 1- to 2-Year-Old Folic Acid and Pregnancy KidsHealth > For Parents > Folic Acid and ... before conception and during early pregnancy . About Folic Acid Folic acid, sometimes called folate, is a B ...

  3. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  4. New Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to new compounds, 7,10-dihydroxy-8(E)-octadecen...

  5. New bioactive fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to the new compounds, 7,10-dihydroxy-8(E)-octad...

  6. Stability and solubility enhancement of ellagic acid in cellulose ester solid dispersions.

    PubMed

    Li, Bin; Harich, Kim; Wegiel, Lindsay; Taylor, Lynne S; Edgar, Kevin J

    2013-02-15

    Structurally varied, carboxyl-containing cellulose derivatives were evaluated for their ability to form amorphous solid dispersions (ASD) with ellagic acid (EA), in order to improve the solubility of this high-melting, poorly bioavailable, but highly bioactive natural flavonoid compound. ASDs of EA with carboxymethylcellulose acetate butyrate (CMCAB), cellulose acetate adipate propionate (CAAdP), and hydroxypropylmethylcellulose acetate succinate (HPMCAS) were prepared, and EA dissolution from these ASDs was compared with that from pure crystalline EA and from EA/poly(vinylpyrrolidinone) (PVP) solid dispersions (SD). Polymer/drug mixtures were characterized by powder X-ray diffraction (XRPD), modulated differential scanning calorimetry (MDSC), nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR). The XRPD and FT-IR results indicated that EA was amorphous in solid dispersions with EA concentration up to 25 wt%. The stability against crystallization and solution concentrations of EA from these solid dispersions were significantly higher than those observed for physical mixtures and pure crystalline EA. HPMCAS stabilized EA most effectively, among the polymers tested, against both chemical degradation and recrystallization. The relative ability to solubilize EA from ASDs at pH 6.8 was PVP>HPMCAS>CMCAB. EA dissolves from ASD in PVP quickly and completely (maximum 92%) at pH 6.8, but EA is also released from PVP at pH 1.2, and then crystallizes rapidly. Therefore PVP is not a practical candidate for EA ASD. In contrast, the cellulose derivative ASDs show very slow EA release at pH 1.2 (<4%) and faster but still incomplete drug release at pH 6.8 (maximum 35% for HPMCAS SD). The pH-triggered drug release from HPMCAS ASD makes HPMCAS a practical choice for EA solubility enhancement.

  7. Acid rain

    SciTech Connect

    Boyle, R.H.; Boyle, R.A.

    1983-01-01

    Acid rain, says Boyle is a chemical leprosy eating into the face of North America and Europe, perhaps the major ecological problem of our time. Boyle describes the causes and scope of the phenomenon; the effects on man, wildlife, water, and our cultural heritage. He probes the delays of politicians and the frequent self-serving arguments advanced by industry in the face of what scientists have proved. The solutions he offers are to strengthen the Clean Air Act and require emission reductions that can be accomplished by establishing emission standards on a regional or bubble basis, burn low-sulfur coal, install scrubbers at critical plants, and invest in alternative energy sources. 73 references, 1 figure.

  8. Seasonal characteristics of oxalic acid and related SOA in the free troposphere of Mt. Hua, central China: implications for sources and formation mechanisms.

    PubMed

    Meng, Jingjing; Wang, Gehui; Li, Jianjun; Cheng, Chunlei; Ren, Yanqin; Huang, Yao; Cheng, Yuting; Cao, Junji; Zhang, Ting

    2014-09-15

    PM10 aerosols from the summit of Mt. Hua (2060 m a.s.l) in central China during the winter and summer of 2009 were analyzed for dicarboxylic acids, ketocarboxylic acids and α-dicarbonyls. Molecular composition of dicarboxylic acids (C2-C11) in the free tropospheric aerosols reveals that oxalic acid (C2, 399 ± 261 ng m(-3) in winter and 522 ± 261 ng m(-3) in summer) is the most abundant species in both seasons, followed by malonic (C3) and succinic (C4) acids, being consistent with that on ground levels. Most of the diacids are more abundant in summer than in winter, but adipic (C6) and phthalic (Ph) acids are twice lower in summer, suggesting more significant impact of anthropogenic pollution on the wintertime alpine atmosphere. Moreover, glyoxal (Gly) and methylglyoxal (mGly) are also lower in summer (12 ± 6.1 ng m(-3)) than in winter (22 ± 13 ng m(-3)). As both dicarbonyls are a major precursor of C2, their seasonal variation patterns, which are opposite to those of the diacids, indicate that the mountain troposphere is more oxidative in summer. C2 showed strong linear correlations with levoglucosan in winter and oxidation products of isoprene and monoterpene in summer. PCA analysis further suggested that the wintertime C2 and related SOA in the Mt. Hua troposphere mostly originate from photochemical oxidations of anthropogenic pollutants emitted from biofuel and coal combustion in lowland regions. On contrast, the summertime C2 and related SOA mostly originate from further oxidation of the mountainous isoprene and monoterpene oxidation products. The AIM model calculation results showed that oxalic acid concentration well correlated with particle acidity (R(2)=0.60) but not correlated with particle liquid water content, indicating that particle acidity favors the organic acid formation because aqueous-phase C2 production is the primary mechanism of C2 formation in ambient aerosols and is driven by acid-catalyzed oxidation.

  9. Effects of total gastrectomy on plasma silicon and amino acid concentrations in men.

    PubMed

    Tatara, Marcin R; Krupski, Witold; Szpetnar, Maria; Dąbrowski, Andrzej; Bury, Paweł; Szabelska, Anna; Charuta, Anna; Boguszewska-Czubara, Anna; Maciejewski, Ryszard; Wallner, Grzegorz

    2015-12-01

    The aim of the study was to determine one-year effects of total gastrectomy on plasma silicon and free amino acid concentrations in patients and evaluate changes of volumetric bone mineral density (vBMD) in lumbar spine. Eight patients were enrolled to the control (CTR) group. Six patients subjected to total gastrectomy (GX group) were included to the experimental group. vBMD in trabecular and cortical bone was measured in lumbar vertebrae at baseline (before surgery) and one year later using quantitative computed tomography. Plasma concentrations of silicon and free amino acids were determined at baseline and one year later using photometric method and ion-exchange chromatography. Body weights within CTR and GX groups were not different after one-year follow-up when compared to the baseline values (P > 0.05). An average annual decrease of vBMD in the trabecular bone in the gastrectomized patients reached 15.0% in lumbar spine and was significantly different in comparison to the percentage changes observed in CTR group (P = 0.02). One-year percentage change of vBMD in the cortical bone in L1 and L2 has shown significantly decreased values by 10.5 and 9.1% in the GX group when compared to the percentage change observed in the controls (P < 0.05). Plasma concentration of adipic acid was significantly higher by 101.6% one year after total gastrectomy procedure in the patients when compared to the baseline value (P = 0.01). Plasma concentration of silicon was significantly lowered by 26.7% one year after the total gastrectomy when compared to the baseline value (P = 0.009). Total gastrectomy in patients has induced severe osteoporotic changes in lumbar spine within one-year period. The observed osteoporotic changes were associated with decreased plasma concentration of silicon indicating importance of exocrine and endocrine functions of stomach for silicon homeostasis maintenance. Gastrectomy-induced bone loss was not related to decreased amino acid

  10. 21 CFR 178.3690 - Pentaerythritol adipate-stearate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (4) Iodine number not to exceed 2 as determined by Iodine Absorption Number, Hanus Method, of the “Official Methods...

  11. 21 CFR 178.3690 - Pentaerythritol adipate-stearate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (4) Iodine number not to exceed 2 as determined by Iodine Absorption Number, Hanus Method, of the “Official Methods...

  12. 21 CFR 178.3690 - Pentaerythritol adipate-stearate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (4) Iodine number not to exceed 2 as determined by Iodine Absorption Number, Hanus Method, of the “Official Methods...

  13. 21 CFR 178.3690 - Pentaerythritol adipate-stearate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. (4) Iodine number not to exceed 2 as determined by Iodine Absorption Number, Hanus Method, of the “Official Methods...

  14. [Teichoic acids from lactic acid bacteria].

    PubMed

    Livins'ka, O P; Harmasheva, I L; Kovalenko, N K

    2012-01-01

    The current view of the structural diversity of teichoic acids and their involvement in the biological activity of lactobacilli has been reviewed. The mechanisms of effects of probiotic lactic acid bacteria, in particular adhesive and immunostimulating functions have been described. The prospects of the use of structure data of teichoic acid in the assessment of intraspecific diversity of lactic acid bacteria have been also reflected.

  15. Organic acids tunably catalyze carbonic acid decomposition.

    PubMed

    Kumar, Manoj; Busch, Daryle H; Subramaniam, Bala; Thompson, Ward H

    2014-07-10

    Density functional theory calculations predict that the gas-phase decomposition of carbonic acid, a high-energy, 1,3-hydrogen atom transfer reaction, can be catalyzed by a monocarboxylic acid or a dicarboxylic acid, including carbonic acid itself. Carboxylic acids are found to be more effective catalysts than water. Among the carboxylic acids, the monocarboxylic acids outperform the dicarboxylic ones wherein the presence of an intramolecular hydrogen bond hampers the hydrogen transfer. Further, the calculations reveal a direct correlation between the catalytic activity of a monocarboxylic acid and its pKa, in contrast to prior assumptions about carboxylic-acid-catalyzed hydrogen-transfer reactions. The catalytic efficacy of a dicarboxylic acid, on the other hand, is significantly affected by the strength of an intramolecular hydrogen bond. Transition-state theory estimates indicate that effective rate constants for the acid-catalyzed decomposition are four orders-of-magnitude larger than those for the water-catalyzed reaction. These results offer new insights into the determinants of general acid catalysis with potentially broad implications.

  16. Plasma amino acids

    MedlinePlus

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  17. Uric acid - urine

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003616.htm Uric acid urine test To use the sharing features on this page, please enable JavaScript. The uric acid urine test measures the level of uric acid ...

  18. Facts about Folic Acid

    MedlinePlus

    ... Information For... Media Policy Makers Facts About Folic Acid Language: English Español (Spanish) Recommend on Facebook Tweet ... of the baby's brain and spine. About folic acid Folic acid is a B vitamin. Our bodies ...

  19. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... of the cells in the stomach to release acid. The stomach contents are then removed and analyzed. ... 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour in ...

  20. Methylmalonic acid blood test

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003565.htm Methylmalonic acid blood test To use the sharing features on this page, please enable JavaScript. The methylmalonic acid blood test measures the amount of methylmalonic acid ...

  1. Uric acid test (image)

    MedlinePlus

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  2. Fatty Acid Oxidation Disorders

    MedlinePlus

    ... other health conditions > Fatty acid oxidation disorders Fatty acid oxidation disorders E-mail to a friend Please ... these disorders, go to genetests.org . What fatty acid oxidation disorders are tested for in newborn screening? ...

  3. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  4. Affinity purification of antibodies using immobilized FB domain of protein A.

    PubMed

    Solomon, B; Raviv, O; Leibman, E; Fleminger, G

    1992-04-24

    A continuous method for the efficient digestion of protein A into active fragments (FB, Mr = 7000) using immobilized trypsin was developed. These fragments originate from almost identical five-repeated monovalent Fc-binding units of 58 residues each. The fragments obtained were found to be similar to the recently described genetically engineered fragment B. Antibody-binding characteristics of the FB domain and also of intact protein A, immobilized on to adipic dihydrazide-modified Eupergit CB6200 beads, were investigated. Based on the experimental data obtained, a high-performance liquid chromatographic column containing C30N Eupergit C-immobilized FB domain was prepared and its performance in antibody purification was compared with that of Eupergit C-immobilized intact protein A.

  5. Polar organic marker compounds in atmospheric aerosol in the Po Valley during the Supersito campaigns - Part 1: Low molecular weight carboxylic acids in cold seasons

    NASA Astrophysics Data System (ADS)

    Pietrogrande, Maria Chiara; Bacco, Dimitri; Visentin, Marco; Ferrari, Silvia; Poluzzi, Vanes

    2014-04-01

    In the framework of the “Supersito” project, three intensive experimental campaigns were conducted in the Po Valley (Northern Italy) in cold seasons, such as late autumn, pre-winter and deep-winter, over three years from 2011 to 2013. As a part of a study on polar marker compounds, including carboxylic acids, sugar derivatives and lignin phenols, the present study reports a detailed discussion on the atmospheric concentrations of 14 low molecular weight carboxylic acids, mainly dicarboxylic and oxo-hydroxy carboxylic acids, as relevant markers of primary and secondary organic aerosols. PM2.5 samples were collected in two monitoring sites, representing urban and rural background stations. The total quantities of carboxylic acids were 262, 167 and 249 ng m-3 at the urban site and 308, 115, 248 ng m-3 at the rural site in pre-winter, fall and deep-winter, respectively. These high concentrations can be explained by the large human emission sources in the urbanized region, combined with the stagnant atmospheric conditions during the cold seasons that accumulate the organic precursors and accelerate the secondary atmospheric reactions. The distribution profiles of the investigated markers suggest the dominant contributions of primary anthropogenic sources, such as traffic, domestic heating and biomass burning. These results are confirmed by comparison with additional emission tracers, such as anhydro-saccharides for biomass burning and fatty acids originated from different anthropogenic sources. In addition, some secondary constituents were detected in both sites, as produced by in situ photo-chemical reactions from both biogenic (e.g. pinonic acid) and anthropogenic precursors (e.g. phthalic and adipic acids). The impact of different sources from human activities was elucidated by investigating the week pattern of carboxylic and fatty acid concentrations. The weekly trends of analytes during the warmer campaign (fall 2012; mean temperature: 12 °C) may be related to

  6. Acid tolerance in amphibians

    SciTech Connect

    Pierce, B.A.

    1985-04-01

    Studies of amphibian acid tolerance provide information about the potential effects of acid deposition on amphibian communities. Amphibians as a group appear to be relatively acid tolerant, with many species suffering increased mortality only below pH 4. However, amphibians exhibit much intraspecific variation in acid tolerance, and some species are sensitive to even low levels of acidity. Furthermore, nonlethal effects, including depression of growth rates and increases in developmental abnormalities, can occur at higher pH.

  7. Preparation and Cross-Linking of All-Acrylamide Diblock Copolymer Nano-Objects via Polymerization-Induced Self-Assembly in Aqueous Solution

    PubMed Central

    2017-01-01

    Various carboxylic acid-functionalized poly(N,N-dimethylacrylamide) (PDMAC) macromolecular chain transfer agents (macro-CTAs) were chain-extended with diacetone acrylamide (DAAM) by reversible addition–fragmentation chain transfer (RAFT) aqueous dispersion polymerization at 70 °C and 20% w/w solids to produce a series of PDMAC–PDAAM diblock copolymer nano-objects via polymerization-induced self-assembly (PISA). TEM studies indicate that a PDMAC macro-CTA with a mean degree of polymerization (DP) of 68 or higher results in the formation of well-defined spherical nanoparticles with mean diameters ranging from 40 to 150 nm. In contrast, either highly anisotropic worms or polydisperse vesicles are formed when relatively short macro-CTAs (DP = 40–58) are used. A phase diagram was constructed to enable accurate targeting of pure copolymer morphologies. Dynamic light scattering (DLS) and aqueous electrophoresis studies indicated that in most cases these PDMAC–PDAAM nano-objects are surprisingly resistant to changes in either solution pH or temperature. However, PDMAC40–PDAAM99 worms do undergo partial dissociation to form a mixture of relatively short worms and spheres on adjusting the solution pH from pH 2–3 to around pH 9 at 20 °C. Moreover, a change in copolymer morphology from worms to a mixture of short worms and vesicles was observed by DLS and TEM on heating this worm dispersion to 50 °C. Postpolymerization cross-linking of concentrated aqueous dispersions of PDMAC–PDAAM spheres, worms, or vesicles was performed at ambient temperature using adipic acid dihydrazide (ADH), which reacts with the hydrophobic ketone-functionalized PDAAM chains. The formation of hydrazone groups was monitored by FT-IR spectroscopy and afforded covalently stabilized nano-objects that remained intact on exposure to methanol, which is a good solvent for both blocks. Rheological studies indicated that the cross-linked worms formed a stronger gel compared to linear precursor

  8. Gas-phase acidities of aspartic acid, glutamic acid, and their amino acid amides

    NASA Astrophysics Data System (ADS)

    Li, Zhong; Matus, Myrna H.; Velazquez, Hector Adam; Dixon, David A.; Cassady, Carolyn J.

    2007-09-01

    Gas-phase acidities (GA or [Delta]Gacid) for the two most acidic common amino acids, aspartic acid and glutamic acid, have been determined for the first time. Because of the amide linkage's importance in peptides and as an aid in studying side chain versus main chain deprotonation, aspartic acid amide and glutamic acid amide were also studied. Experimental GA values were measured by proton transfer reactions in an electrospray ionization/Fourier transform ion cyclotron resonance mass spectrometer. Calculated GAs were obtained by density functional and molecular orbital theory approaches. The best agreement with experiment was found at the G3MP2 level; the MP2/CBS and B3LYP/aug-cc-pVDZ results are 3-4 kcal/mol more acidic than the G3MP2 results. Experiment shows that aspartic acid is more acidic than glutamic acid by ca. 3 kcal/mol whereas the G3MP2 results show a smaller acidity difference of 0.2 kcal/mol. Similarly, aspartic acid amide is experimentally observed to be ca. 2 kcal/mol more acidic than glutamic acid amide whereas the G3MP2 results show a correspondingly smaller energy difference of 0.7 kcal/mol. The computational results clearly show that the anions are all ring-like structures with strong hydrogen bonds between the OH or NH2 groups and the CO2- group from which the proton is removed. The two amino acids are main-chain deprotonated. In addition, use of the COSMO model for the prediction of the free energy differences in aqueous solution gave values in excellent agreement with the most recent experimental values for pKa. Glutamic acid is predicted to be more acidic than aspartic acid in aqueous solution due to differential solvation effects.

  9. Reducing mechanical activation-induced amorphisation of salbutamol sulphate by co-processing with selected carboxylic acids.

    PubMed

    Curtin, Vincent; Amharar, Youness; Gallagher, Kieran H; Corcoran, Sarah; Tajber, Lidia; Corrigan, Owen I; Healy, Anne Marie

    2013-11-18

    The unintentional generation of amorphous character in crystalline active pharmaceutical ingredients (APIs) is an adverse consequence of mechanical activation during dosage form manufacture. In this study, we assess and compare the ability of low glass transition temperature (Tg) dicarboxylic acids to mitigate amorphisation of a model API, salbutamol sulphate (SS), on both co-milling and co-mixing. SS processed alone, as well as co-milled and co-mixed composites of the API with glutaric acid (GA), adipic acid (AA) and pimelic acid (PA) were characterised by powder X-ray diffraction (pXRD), differential scanning calorimetry (DSC) and dynamic vapour sorption (DVS). Milling and dry mixing of SS both resulted in pXRD amorphous materials. No amorphous content of SS was detected by DVS on co-milling with 50% (w/w) GA, while amorphisation was more than halved, relative to the API milled alone, on co-milling with 50% (w/w) AA and PA, respectively. Co-mixing with each excipient also resulted in a decrease in API amorphicity, although the extent of reduction was considerably less compared to the co-milling experiments. The solubility (Solexcipient) of each excipient in amorphous SS was determined by thermal methods. No further reduction in API amorphisation was achieved on co-mixing with 50% (w/w) excipient, compared to concentrations corresponding to the solubility of each excipient in the amorphous API (SolGA=36%, SolAA=21%, SolPA=22%). PXRD confirmed gradual dissolution over time of GA in amorphous SS on co-mixing. In contrast to co-mixing, co-milling SS at excipient weight fractions above their respective solubilities in the amorphous drug resulted in further reductions in API amorphisation. This is thought to be due to the generation of a molecular dispersion of amorphous API, supersaturated with excipient, thereby leading to a more pronounced composite Tg lowering effect. The results indicate that co-processing with low Tg excipients is an effective strategy at

  10. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    This communication notes the actual magnitude of the acidity in acidic fog particles and suggests a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air.

  11. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  12. Fatty acid analogs

    DOEpatents

    Elmaleh, David R.; Livni, Eli

    1985-01-01

    In one aspect, a radioactively labeled analog of a fatty acid which is capable of being taken up by mammalian tissue and which exhibits an in vivo beta-oxidation rate below that with a corresponding radioactively labeled fatty acid.

  13. Omega-3 fatty acids

    PubMed Central

    Schwalfenberg, Gerry

    2006-01-01

    OBJECTIVE To examine evidence for the role of omega-3 fatty acids in cardiovascular disease. QUALITY OF EVIDENCE PubMed was searched for articles on the role of omega-3 fatty acids in cardiovascular disease. Level I and II evidence indicates that omega-3 fatty acids are beneficial in improving cardiovascular outcomes. MAIN MESSAGE Dietary intake of omega-3 fatty acids has declined by 80% during the last 100 years, while intake of omega-6 fatty acids has greatly increased. Omega-3 fatty acids are cardioprotective mainly due to beneficial effects on arrhythmias, atherosclerosis, inflammation, and thrombosis. There is also evidence that they improve endothelial function, lower blood pressure, and significantly lower triglycerides. CONCLUSION There is good evidence in the literature that increasing intake of omega-3 fatty acids improves cardiac outcomes. Physicians need to integrate dietary recommendations for consumption of omega-3 fatty acids into their usual cardiovascular care. PMID:16812965

  14. Sulfuric acid poisoning

    MedlinePlus

    Sulfuric acid is a very strong chemical that is corrosive. Corrosive means it can cause severe burns and ... or mucous membranes. This article discusses poisoning from sulfuric acid. This article is for information only. Do NOT ...

  15. Lactic acid test

    MedlinePlus

    Lactate test ... test. Exercise can cause a temporary increase in lactic acid levels. ... not getting enough oxygen. Conditions that can increase lactic acid levels include: Heart failure Liver disease Lung disease ...

  16. Folic Acid Quiz

    MedlinePlus

    ... About Us Information For... Media Policy Makers Folic Acid Quiz Language: English Español (Spanish) Recommend on Facebook ... button beside the question. Good Luck! 1. Folic acid is: A a B vitamin B a form ...

  17. Hydrochloric acid poisoning

    MedlinePlus

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, such ... poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do NOT ...

  18. Azelaic Acid Topical

    MedlinePlus

    Azelaic acid gel and foam is used to clear the bumps, lesions, and swelling caused by rosacea (a skin ... redness, flushing, and pimples on the face). Azelaic acid cream is used to treat the pimples and ...

  19. Zoledronic Acid Injection

    MedlinePlus

    Zoledronic acid (Reclast) is used to prevent or treat osteoporosis (condition in which the bones become thin and weak ... of life,' end of regular menstrual periods). Zoledronic acid (Reclast) is also used to treat osteoporosis in ...

  20. Alpha Hydroxy Acids

    MedlinePlus

    ... Cosmetics Home Cosmetics Products & Ingredients Ingredients Alpha Hydroxy Acids Share Tweet Linkedin Pin it More sharing options ... for Industry: Labeling for Cosmetics Containing Alpha Hydroxy Acids The following information is intended to answer questions ...

  1. Uric Acid Test

    MedlinePlus

    ... products and services. Advertising & Sponsorship: Policy | Opportunities Uric Acid Share this page: Was this page helpful? Also known as: Serum Urate; UA Formal name: Uric Acid Related tests: Synovial Fluid Analysis , Kidney Stone Analysis , ...

  2. Amino Acid Metabolism Disorders

    MedlinePlus

    ... breaks the food parts down into sugars and acids, your body's fuel. Your body can use this ... process. One group of these disorders is amino acid metabolism disorders. They include phenylketonuria (PKU) and maple ...

  3. Valproic Acid and Pregnancy

    MedlinePlus

    ... live chat Live Help Fact Sheets Share Valproic Acid and Pregnancy Wednesday, 01 July 2015 In every ... This sheet talks about whether exposure to valproic acid may increase the risk for birth defects over ...

  4. Aminocaproic Acid Injection

    MedlinePlus

    Aminocaproic acid injection is used to control bleeding that occurs when blood clots are broken down too quickly. This ... the baby is ready to be born). Aminocaproic acid injection is also used to control bleeding in ...

  5. Omega-6 Fatty Acids

    MedlinePlus

    Omega-6 fatty acids are types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other types of omega-6 fatty acids are found in black currant seed, borage seed, ...

  6. Deoxycholic Acid Injection

    MedlinePlus

    Deoxycholic acid injection is used to improve the appearance and profile of moderate to severe submental fat ('double chin'; fatty tissue located under the chin). Deoxycholic acid injection is in a class of medications called ...

  7. PRODUCTION OF TRIFLUOROACETIC ACID

    DOEpatents

    Haworth, W.N.; Stacey, M.

    1949-07-19

    A method is given for the production of improved yields of trifluoroacetic acid. The compound is prepared by oxidizing m-aminobenzotrifluoride with an alkali metal or alkaline earth metal permanganate at a temperature in the range of 80 deg C to 100 deg C while dissolved ln a mixture of water with glacial acetic acid and/or trifluoroacetic acid. Preferably a mixture of water and trifluoroacetic acid ls used as the solvent.

  8. Refining Lurgi tar acids

    SciTech Connect

    Greco, N.P.

    1984-04-17

    There is disclosed a process for removing tar bases and neutral oils from the Lurgi tar acids by treating the tar acids with aqueous sodium bisulfate to change the tar bases to salts and to hydrolyze the neutral oils to hydrolysis products and distilling the tar acids to obtain refined tar acid as the distillate while the tar base salts and neutral oil hydrolysis products remain as residue.

  9. Plant fatty acid hydroxylases

    DOEpatents

    Somerville, Chris; Broun, Pierre; van de Loo, Frank

    2001-01-01

    This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.

  10. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    The chemical composition of fog particles has become of considerable interest, because of both the possibility of interpreting atmospheric- chemistry processes in fog particles in terms of the principles of aqueous chemistry and the potential health effects of species present in fog particles. The acidity of fog particles has received wide attention. This communication noted the actual magnitude of the excess acidity in acidic fog particles and suggested a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air. (DP)

  11. What Is Acid Rain?

    ERIC Educational Resources Information Center

    Likens, Gene E.

    2004-01-01

    Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…

  12. The Acid Rain Reader.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.; And Others

    A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…

  13. Acid Rain Study Guide.

    ERIC Educational Resources Information Center

    Hunger, Carolyn; And Others

    Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…

  14. Acid Lipase Disease

    MedlinePlus

    ... Page You are here Home » Disorders » All Disorders Acid Lipase Disease Information Page Acid Lipase Disease Information Page What research is being ... research to understand lipid storage diseases such as acid lipase deficiency. Additional research studies hope to identify ...

  15. [alpha]-Oxocarboxylic Acids

    ERIC Educational Resources Information Center

    Kerber, Robert C.; Fernando, Marian S.

    2010-01-01

    Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH…

  16. Organic-Acid-Assisted Fabrication of Low-Cost Li-Rich Cathode Material (Li[Li1/6Fe1/6Ni1/6Mn1/2]O-2) for Lithium-Ion Battery

    SciTech Connect

    Zhao, Taolin; Chen, Shi; Li, Li; Zhang, Xiaoxiao; Wu, Huiming; Wu, Tianpin; Sun, Cheng-Jun; Chen, Renjie; Wu, Feng; Lu, Jun; Amine, Khalil

    2014-12-24

    A novel Li-rich cathode Li[Li1/6Fe1/6Ni1/6Mn1/2]O-2 (0.4Li(2)MnO(3-)0.6LiFe(1/3)Ni(1/3)Mn(1/3)O(2)) was synthesized by a solgel method, which uses citric acid (SC), tartaric acid (ST), or adipic acid (SA) as a chelating agent. The structural, morphological, and electrochemical properties of the prepared samples were characterized by various methods. X-ray diffraction showed that single-phase materials are formed mainly with typical alpha-NaFeO2 layered structure (R3 m), and the SC sample has the lowest Li/Ni cation disorder. The morphological study indicated homogeneous primary particles in good distribution size (100 nm) with small aggregates. The Fe, Ni, and Mn valences were determined by X-ray absorption near-edge structure analysis. In coin cell tests, the initial reversible discharge capacity of an SA electrode was 289.7 mAh g(-1) at the 0.1C rate in the 1.54.8 V voltage range, while an SC electrode showed a better cycling stability with relatively high capacity retention. At the 2C rate, the SC electrode can deliver a discharge capacity of 150 mAh g(-1) after 50 cycles. Differential capacity vs voltage curves were employed to further investigate the electrochemical reactions and the structural change process during cycling. This low-cost, Fe-based compound prepared by the solgel method has the potential to be used as the high capacity cathode material for Liion batteries.

  17. Organic-acid-assisted fabrication of low-cost Li-rich cathode material (Li[Li1/6Fe1/6Ni1/6Mn1/2]O2) for lithium-ion battery.

    PubMed

    Zhao, Taolin; Chen, Shi; Li, Li; Zhang, Xiaoxiao; Wu, Huiming; Wu, Tianpin; Sun, Cheng-Jun; Chen, Renjie; Wu, Feng; Lu, Jun; Amine, Khalil

    2014-12-24

    A novel Li-rich cathode Li[Li1/6Fe1/6Ni1/6Mn1/2]O2 (0.4Li2MnO3-0.6LiFe1/3Ni1/3Mn1/3O2) was synthesized by a sol-gel method, which uses citric acid (SC), tartaric acid (ST), or adipic acid (SA) as a chelating agent. The structural, morphological, and electrochemical properties of the prepared samples were characterized by various methods. X-ray diffraction showed that single-phase materials are formed mainly with typical α-NaFeO2 layered structure (R3̅m), and the SC sample has the lowest Li/Ni cation disorder. The morphological study indicated homogeneous primary particles in good distribution size (100 nm) with small aggregates. The Fe, Ni, and Mn valences were determined by X-ray absorption near-edge structure analysis. In coin cell tests, the initial reversible discharge capacity of an SA electrode was 289.7 mAh g(-1) at the 0.1C rate in the 1.5-4.8 V voltage range, while an SC electrode showed a better cycling stability with relatively high capacity retention. At the 2C rate, the SC electrode can deliver a discharge capacity of 150 mAh g(-1) after 50 cycles. Differential capacity vs voltage curves were employed to further investigate the electrochemical reactions and the structural change process during cycling. This low-cost, Fe-based compound prepared by the sol-gel method has the potential to be used as the high capacity cathode material for Li-ion batteries.

  18. Group B Streptococcus Capsular Polysaccharide-Cholera Toxin B Subunit Conjugate Vaccines Prepared by Different Methods for Intranasal Immunization

    PubMed Central

    Shen, Xuzhuang; Lagergård, Teresa; Yang, Yonghong; Lindblad, Marianne; Fredriksson, Margareta; Holmgren, Jan

    2001-01-01

    Group B Streptococcus (GBS) type III capsular polysaccharide (CPS III) was conjugated to recombinant cholera toxin B subunit (rCTB) using three different methods which employed (i) cystamine and N-succinimidyl-3-(2-pyridyldithio)propionate (SPDP), (ii) carbodiimide with adipic acid dihydrazide (ADH) as a spacer, or (iii) reductive amination (RA). The CPS III-rCTB conjugates were divided into large- and small-molecular-weight (Mr) fractions, and the immunogenicities of the different preparations after intranasal (i.n.) immunization were studied in mice. Both large- and small-Mr conjugates of CPS III-rCTBRA or CPS III-rCTBADH induced high, almost comparable levels of CPS-specific immunoglobulin G (IgG) in serum, lungs, and vagina that were generally superior to those obtained with CPS III-rCTBSPDP conjugates or a CPS III and rCTB mixture. However, the smaller-Mr conjugates of CPS III-rCTBRA or CPS III-rCTBADH in most cases elicited a lower anti-CPS IgA immune response than the large-Mr conjugates, and the highest anti-CPS IgA titers in both tissues and serum were obtained with the large-Mr CPS III-rCTBRA conjugate. Serum IgG anti-CPS titers induced by the CPS III-rCTBRA conjugate had high levels of specific IgG1, IgG2a, IgG2b, and IgG3 antibodies. Based on the effectiveness of RA for coupling CPS III to rCTB, RA was also tested for conjugating GBS CPS Ia with rCTB. As for the CPS III-rCTB conjugates, the immunogenicity of CPS Ia was greatly increased by conjugation to rCTB. Intranasal immunization with a combination of CPS Ia-rCTB and CPS III-rCTB conjugates was shown to induce anti-CPS Ia and III immune responses in serum and lungs that were fully comparable with the responses to immunization with the monovalent CPS Ia-rCTB or CPS III-rCTB conjugates. These results suggest that the GBS CPS III-rCTB and CPS Ia-rCTB conjugates prepared by the RA method may be used in bivalent and possibly also in multivalent mucosal GBS conjugate vaccines. PMID:11119518

  19. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow; Mary Ann D.; Dahlberg, James E.

    2010-11-09

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  20. Amino acid analysis

    NASA Technical Reports Server (NTRS)

    Winitz, M.; Graff, J. (Inventor)

    1974-01-01

    The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.

  1. Editorial: Acid precipitation

    SciTech Connect

    1995-09-01

    This editorial focuses on acid rain and the history of public and governmental response to acid rain. Comments on a book by Gwineth Howell `Acid Rain and Acid Waters` are included. The editor feels that Howells has provide a service to the environmental scientific community, with a textbook useful to a range of people, as well as a call for decision makers to learn from the acid rain issue and use it as a model for more sweeping global environmental issues. A balance is needed among several parameters such as level of evidence, probability that the evidence will lead to a specific direction and the cost to the global community. 1 tab.

  2. Nucleic acid detection compositions

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James L.

    2008-08-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  3. Nucleic acid detection assays

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James E.

    2005-04-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  4. Cleavage of nucleic acids

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor L.; Brow, Mary Ann D.; Dahlberg, James E.

    2007-12-11

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  5. Nucleic acid detection kits

    DOEpatents

    Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.

    2005-03-29

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.

  6. Acidic Ionic Liquids.

    PubMed

    Amarasekara, Ananda S

    2016-05-25

    Ionic liquid with acidic properties is an important branch in the wide ionic liquid field and the aim of this article is to cover all aspects of these acidic ionic liquids, especially focusing on the developments in the last four years. The structural diversity and synthesis of acidic ionic liquids are discussed in the introduction sections of this review. In addition, an unambiguous classification system for various types of acidic ionic liquids is presented in the introduction. The physical properties including acidity, thermo-physical properties, ionic conductivity, spectroscopy, and computational studies on acidic ionic liquids are covered in the next sections. The final section provides a comprehensive review on applications of acidic ionic liquids in a wide array of fields including catalysis, CO2 fixation, ionogel, electrolyte, fuel-cell, membrane, biomass processing, biodiesel synthesis, desulfurization of gasoline/diesel, metal processing, and metal electrodeposition.

  7. Boric acid and boronic acids inhibition of pigeonpea urease.

    PubMed

    Reddy, K Ravi Charan; Kayastha, Arvind M

    2006-08-01

    Urease from the seeds of pigeonpea was competitively inhibited by boric acid, butylboronic acid, phenylboronic acid, and 4-bromophenylboronic acid; 4-bromophenylboronic acid being the strongest inhibitor, followed by boric acid > butylboronic acid > phenylboronic acid, respectively. Urease inhibition by boric acid is maximal at acidic pH (5.0) and minimal at alkaline pH (10.0), i.e., the trigonal planar B(OH)3 form is a more effective inhibitor than the tetrahedral B(OH)4 -anionic form. Similarly, the anionic form of phenylboronic acid was least inhibiting in nature.

  8. Biotransformation of cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid by plant cell cultures of Eucalyptus perriniana.

    PubMed

    Katsuragi, Hisashi; Shimoda, Kei; Kubota, Naoji; Nakajima, Nobuyoshi; Hamada, Hatsuyuki; Hamada, Hiroki

    2010-01-01

    Biotransformations of phenylpropanoids such as cinnamic acid, p-coumaric acid, caffeic acid, and ferulic acid were investigated with plant-cultured cells of Eucalyptus perriniana. The plant-cultured cells of E. perriniana converted cinnamic acid into cinnamic acid β-D-glucopyranosyl ester, p-coumaric acid, and 4-O-β-D-glucopyranosylcoumaric acid. p-Coumaric acid was converted into 4-O-β-D-glucopyranosylcoumaric acid, p-coumaric acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcoumaric acid β-D-glucopyranosyl ester, a new compound, caffeic acid, and 3-O-β-D-glucopyranosylcaffeic acid. On the other hand, incubation of caffeic acid with cultured E. perriniana cells gave 3-O-β-D-glucopyranosylcaffeic acid, 3-O-(6-O-β-D-glucopyranosyl)-β-D-glucopyranosylcaffeic acid, a new compound, 3-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, 4-O-β-D-glucopyranosylcaffeic acid, 4-O-β-D-glucopyranosylcaffeic acid β-D-glucopyranosyl ester, ferulic acid, and 4-O-β-D-glucopyranosylferulic acid. 4-O-β-D-Glucopyranosylferulic acid, ferulic acid β-D-glucopyranosyl ester, and 4-O-β-D-glucopyranosylferulic acid β-D-glucopyranosyl ester were isolated from E. perriniana cells treated with ferulic acid.

  9. Process for the preparation of lactic acid and glyceric acid

    DOEpatents

    Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI

    2008-12-02

    Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.

  10. Interactions of methylamine and ammonia with atmospheric nucleation precursor H2SO4 and common organic acids: Thermodynamics and atmospheric implications

    NASA Astrophysics Data System (ADS)

    Xu, Y.; Nadykto, A. B.; Jiang, L.; Bai, Z.

    2016-06-01

    Interactions of the two common atmospheric bases, ammonia (NH3) and methylamine MA (CH3NH2), which are considered to be important stabilizers of binary clusters in the Earth's atmosphere, with H2SO4, the key atmospheric precursor, and 14 common atmospheric organic acids (COA) (formic (CH2O2), acetic (C2H4O2), oxalic (C2H2O4), malonic (C3H4O4), succinic (C4H6O4), glutaric acid (C5H8O4), adipic (C6H10O4), benzoic (C6H5COOH), phenylacetic (C6H5CH2COOH), pyruvic (C3H4O3), maleic acid (C4H4O4), malic (C4H6O5), tartaric (C4H6O6) and pinonic acid (C10H16O3)) have been studied using the composite high-accuracy G3MP2 method. The thermodynamic stability of mixed (COA) (H2SO4), (COA)(B1) and (COA)(B2) dimers and (COA) (H2SO4) (B1) and (COA) (H2SO4) (B1) trimers, where B1 and B2 represent methylamine (CH3NH2) and ammonia (NH3), respectively, have been investigated and their impacts on the thermodynamic stability of clusters containing H2SO4 have been analyzed. It has been shown that in many cases the interactions of H2SO4 with COA, ammonia and methylamine lead to the formation of heteromolecular dimers and trimers, which are certainly more stable than (H2SO4)2 and (H2SO4)3. It has also been found that free energies of (COA) (H2SO4)+ CH3NH2⇔(COA) (H2SO4)(CH3NH2) reactions exceed 10-15 kcal mol-1. This is a clear indication that mixed trimers composed of COA, H2SO4 and methylamine are very stable and can thus serve as possible nucleation sites. The present study leads us to conclude that the interactions of COA coexisting with H2SO4 and common atmospheric bases in the Earth's atmosphere may be an important factor affecting the stability of nucleating sulfuric acid clusters and that the impacts of COA on atmospheric nucleation should be studied in further details.

  11. Microorganisms for producing organic acids

    DOEpatents

    Pfleger, Brian Frederick; Begemann, Matthew Brett

    2014-09-30

    Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.

  12. Citric Acid Alternative to Nitric Acid Passivation

    NASA Technical Reports Server (NTRS)

    Lewis, Pattie L. (Compiler)

    2013-01-01

    The Ground Systems Development and Operations GSDO) Program at NASA John F. Kennedy Space Center (KSC) has the primary objective of modernizing and transforming the launch and range complex at KSC to benefit current and future NASA programs along with other emerging users. Described as the launch support and infrastructure modernization program in the NASA Authorization Act of 2010, the GSDO Program will develop and implement shared infrastructure and process improvements to provide more flexible, affordable, and responsive capabilities to a multi-user community. In support of the GSDO Program, the purpose of this project is to demonstratevalidate citric acid as a passivation agent for stainless steel. Successful completion of this project will result in citric acid being qualified for use as an environmentally preferable alternative to nitric acid for passivation of stainless steel alloys in NASA and DoD applications.

  13. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  14. Recovery of organic acids

    DOEpatents

    Verser, Dan W [Menlo Park, CA; Eggeman, Timothy J [Lakewood, CO

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  15. USGS Tracks Acid Rain

    USGS Publications Warehouse

    Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.

    1995-01-01

    The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.

  16. Parenteral Nutrition: Amino Acids.

    PubMed

    Hoffer, Leonard John

    2017-03-10

    There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness.

  17. Parenteral Nutrition: Amino Acids

    PubMed Central

    Hoffer, Leonard John

    2017-01-01

    There is growing interest in nutrition therapies that deliver a generous amount of protein, but not a toxic amount of energy, to protein-catabolic critically ill patients. Parenteral amino acids can achieve this goal. This article summarizes the biochemical and nutritional principles that guide parenteral amino acid therapy, explains how parenteral amino acid solutions are formulated, and compares the advantages and disadvantages of different parenteral amino acid products with enterally-delivered whole protein products in the context of protein-catabolic critical illness. PMID:28287411

  18. Diterpenoid acids from Grindelia nana.

    PubMed

    Mahmoud, A A; Ahmed, A A; Tanaka, T; Iinuma, M

    2000-03-01

    Two new norditerpenoid acids of the labdane-type (norgrindelic acids), 4,5-dehydro-6-oxo-18-norgrindelic acid (1) and 4beta-hydroxy-6-oxo-19-norgrindelic acid (2), as well as a new grindelic acid derivative, 18-hydroxy-6-oxogrindelic acid (3), were isolated from the aerial parts of Grindelia nana. In addition, the known compounds, 6-oxogrindelic acid, grindelic acid, methyl grindeloate, 7alpha,8alpha-epoxygrindelic acid, and 4alpha-carboxygrindelic acid were also isolated. The structures of the new compounds were characterized on the basis of spectroscopic analysis.

  19. Structure of Acid phosphatases.

    PubMed

    Araujo, César L; Vihko, Pirkko T

    2013-01-01

    Acid phosphatases are enzymes that have been studied extensively due to the fact that their dysregulation is associated with pathophysiological conditions. This characteristic has been exploited for the development of diagnostic and therapeutic methods. As an example, prostatic acid phosphatase was the first marker for metastatic prostate cancer diagnosis and the dysregulation of tartrate resistant acid phosphatase is associated with abnormal bone resorption linked to osteoporosis. The pioneering crystallization studies on prostatic acid phosphatase and mammalian tartrate-resistant acid phosphatase conformed significant milestones towards the elucidation of the mechanisms followed by these enzymes (Schneider et al., EMBO J 12:2609-2615, 1993). Acid phosphatases are also found in nonmammalian species such as bacteria, fungi, parasites, and plants, and most of them share structural similarities with mammalian acid phosphatase enzymes. Acid phosphatase (EC 3.1.3.2) enzymes catalyze the hydrolysis of phosphate monoesters following the general equation. Phosphate monoester + H2O -->/<-- alcohol + phosphate. The general classification "acid phosphatase" relies only on the optimum acidic pH for the enzymatic activity in assay conditions using non-physiological substrates. These enzymes accept a wide range of substrates in vitro, ranging from small organic molecules to phosphoproteins, constituting a heterogeneous group of enzymes from the structural point of view. These structural differences account for the divergence in cofactor dependences and behavior against substrates, inhibitors, and activators. In this group only the tartrate-resistant acid phosphatase is a metallo-enzyme whereas the other members do not require metal-ion binding for their catalytic activity. In addition, tartrate-resistant acid phosphatase and erythrocytic acid phosphatase are not inhibited by L-(+)-tartrate ion while the prostatic acid phosphatase is tartrate-sensitive. This is an important

  20. Presidential Green Chemistry Challenge: 1998 Academic Award (Draths and Frost)

    EPA Pesticide Factsheets

    Presidential Green Chemistry Challenge 1998 award winners, Dr. Karen M. Draths and Professor John W. Frost, used benign, genetically engineered microbes and sugars (instead of benzene) to synthesize adipic acid and catechol.

  1. 40 CFR 52.222 - Negative declarations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) Mojave Desert Air Quality Management District. (i) Natural Gas and Gasoline Processing Equipment and...) Sacramento Metropolitan Air Quality Management District. (i) Plastic Parts Coating: Business Machines and...) Sacramento Metropolitan Air Quality Management District. (i) Nitric and Adipic Acid Manufacturing...

  2. 40 CFR 52.222 - Negative declarations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Implementation Plan. (1) Mojave Desert Air Quality Management District. (i) Natural Gas and Gasoline Processing...) Sacramento Metropolitan Air Quality Management District. (i) Plastic Parts Coating: Business Machines and...) Sacramento Metropolitan Air Quality Management District. (i) Nitric and Adipic Acid Manufacturing...

  3. SYNTHETIC OIL,

    DTIC Science & Technology

    The patent concerns a dicarboxylate-base synthetic oil with antiwear and antioxidation additives. The oil is prepared from the esterification of 2- or 3-methylcyclohexanol and 2-ethylhexanol with adipic acid. (Author)

  4. Real World of Industrial Chemistry: The Romance of HMDA.

    ERIC Educational Resources Information Center

    Wittcoff, Harold

    1979-01-01

    Describes the source of hexamethylenediamine (HMDA). The process of the original synthesis HMDA for nylon manufacture which started with adipic acid and the estimated production cost for alternative HMDA processes are included. (HM)

  5. Folic Acid and Pregnancy

    MedlinePlus

    ... Lessons? Visit KidsHealth in the Classroom What Other Parents Are Reading Your Child's Development (Birth to 3 Years) Feeding Your 1- to 3-Month-Old Feeding Your 4- to 7-Month-Old Feeding Your 8- to 12-Month-Old Feeding Your 1- to 2-Year-Old Folic Acid ... > For Parents > Folic Acid and Pregnancy A A A What's ...

  6. Bile acid transporters

    PubMed Central

    Dawson, Paul A.; Lan, Tian; Rao, Anuradha

    2009-01-01

    In liver and intestine, transporters play a critical role in maintaining the enterohepatic circulation and bile acid homeostasis. Over the past two decades, there has been significant progress toward identifying the individual membrane transporters and unraveling their complex regulation. In the liver, bile acids are efficiently transported across the sinusoidal membrane by the Na+ taurocholate cotransporting polypeptide with assistance by members of the organic anion transporting polypeptide family. The bile acids are then secreted in an ATP-dependent fashion across the canalicular membrane by the bile salt export pump. Following their movement with bile into the lumen of the small intestine, bile acids are almost quantitatively reclaimed in the ileum by the apical sodium-dependent bile acid transporter. The bile acids are shuttled across the enterocyte to the basolateral membrane and effluxed into the portal circulation by the recently indentified heteromeric organic solute transporter, OSTα-OSTβ. In addition to the hepatocyte and enterocyte, subgroups of these bile acid transporters are expressed by the biliary, renal, and colonic epithelium where they contribute to maintaining bile acid homeostasis and play important cytoprotective roles. This article will review our current understanding of the physiological role and regulation of these important carriers. PMID:19498215

  7. Analysis of Organic Acids.

    ERIC Educational Resources Information Center

    Griswold, John R.; Rauner, Richard A.

    1990-01-01

    Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)

  8. Salicylic Acid Topical

    MedlinePlus

    Propa pH® Peel-Off Acne Mask ... pimples and skin blemishes in people who have acne. Topical salicylic acid is also used to treat ... medications called keratolytic agents. Topical salicylic acid treats acne by reducing swelling and redness and unplugging blocked ...

  9. Toxicology of Perfluoroalkyl Acids*

    EPA Science Inventory

    The perfluoroalkyl acids (PFAAs) are a family of organic chemicals consisting of a perfluorinated carbon backbone (4-12 in length) and an acidic functional moiety (carboxylate or sulfonate). These compounds are chemically stable, have excellent surface-tension reducing properties...

  10. Mutant fatty acid desaturase

    DOEpatents

    Shanklin, John; Cahoon, Edgar B.

    2004-02-03

    The present invention relates to a method for producing mutants of a fatty acid desaturase having a substantially increased activity towards fatty acid substrates with chains containing fewer than 18 carbons relative to an unmutagenized precursor desaturase having an 18 carbon atom chain length substrate specificity. The method involves inducing one or more mutations in the nucleic acid sequence encoding the precursor desaturase, transforming the mutated sequence into an unsaturated fatty acid auxotroph cell such as MH13 E. coli, culturing the cells in the absence of supplemental unsaturated fatty acids, thereby selecting for recipient cells which have received and which express a mutant fatty acid desaturase with an elevated specificity for fatty acid substrates having chain lengths of less than 18 carbon atoms. A variety of mutants having 16 or fewer carbon atom chain length substrate specificities are produced by this method. Mutant desaturases produced by this method can be introduced via expression vectors into prokaryotic and eukaryotic cells and can also be used in the production of transgenic plants which may be used to produce specific fatty acid products.

  11. Omega-3 Fatty Acids

    MedlinePlus

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount of triglycerides (a fat-like ... people with very high triglycerides. Omega-3 fatty acids are in a class of medications called antilipemic ...

  12. Amino Acid Crossword Puzzle

    ERIC Educational Resources Information Center

    Sims, Paul A.

    2011-01-01

    Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…

  13. Production of shikimic acid.

    PubMed

    Ghosh, Saptarshi; Chisti, Yusuf; Banerjee, Uttam C

    2012-01-01

    Shikimic acid is a key intermediate for the synthesis of the antiviral drug oseltamivir (Tamiflu®). Shikimic acid can be produced via chemical synthesis, microbial fermentation and extraction from certain plants. An alternative production route is via biotransformation of the more readily available quinic acid. Much of the current supply of shikimic acid is sourced from the seeds of Chinese star anise (Illicium verum). Supply from star anise seeds has experienced difficulties and is susceptible to vagaries of weather. Star anise tree takes around six-years from planting to bear fruit, but remains productive for long. Extraction and purification from seeds are expensive. Production via fermentation is increasing. Other production methods are too expensive, or insufficiently developed. In the future, production in recombinant microorganisms via fermentation may become established as the preferred route. Methods for producing shikimic acid are reviewed.

  14. Fatty acid production from amino acids and alpha-keto acids by Brevibacterium linens BL2.

    PubMed

    Ganesan, Balasubramanian; Seefeldt, Kimberly; Weimer, Bart C

    2004-11-01

    Low concentrations of branched-chain fatty acids, such as isobutyric and isovaleric acids, develop during the ripening of hard cheeses and contribute to the beneficial flavor profile. Catabolism of amino acids, such as branched-chain amino acids, by bacteria via aminotransferase reactions and alpha-keto acids is one mechanism to generate these flavorful compounds; however, metabolism of alpha-keto acids to flavor-associated compounds is controversial. The objective of this study was to determine the ability of Brevibacterium linens BL2 to produce fatty acids from amino acids and alpha-keto acids and determine the occurrence of the likely genes in the draft genome sequence. BL2 catabolized amino acids to fatty acids only under carbohydrate starvation conditions. The primary fatty acid end products from leucine were isovaleric acid, acetic acid, and propionic acid. In contrast, logarithmic-phase cells of BL2 produced fatty acids from alpha-keto acids only. BL2 also converted alpha-keto acids to branched-chain fatty acids after carbohydrate starvation was achieved. At least 100 genes are potentially involved in five different metabolic pathways. The genome of B. linens ATCC 9174 contained these genes for production and degradation of fatty acids. These data indicate that brevibacteria have the ability to produce fatty acids from amino and alpha-keto acids and that carbon metabolism is important in regulating this event.

  15. Total syntheses of cis-cyclopropane fatty acids: dihydromalvalic acid, dihydrosterculic acid, lactobacillic acid, and 9,10-methylenehexadecanoic acid.

    PubMed

    Shah, Sayali; White, Jonathan M; Williams, Spencer J

    2014-12-14

    cis-Cyclopropane fatty acids (cis-CFAs) are widespread constituents of the seed oils of subtropical plants, membrane components of bacteria and protozoa, and the fats and phospholipids of animals. We describe a systematic approach to the synthesis of enantiomeric pairs of four cis-CFAs: cis-9,10-methylenehexadecanoic acid, lactobacillic acid, dihydromalvalic acid, and dihydrosterculic acid. The approach commences with Rh2(OAc)4-catalyzed cyclopropenation of 1-octyne and 1-decyne, and hinges on the preparative scale chromatographic resolution of racemic 2-alkylcycloprop-2-ene-1-carboxylic acids using a homochiral Evan's auxiliary. Saturation of the individual diastereomeric N-cycloprop-2-ene-1-carbonylacyloxazolidines, followed by elaboration to alkylcyclopropylmethylsulfones, allowed Julia-Kocienski olefination with various ω-aldehyde-esters. Finally, saponification and diimide reduction afforded the individual cis-CFA enantiomers.

  16. Molecular distribution, seasonal variation, chemical transformation and sources of dicarboxylic acids and related compounds in atmospheric aerosols at remote marine Gosan site, Jeju Island

    NASA Astrophysics Data System (ADS)

    Kundu, S.; Kawamura, K.; Lee, M.

    2009-12-01

    between Chinese cities and Chichi-jima Island in Japan was observed higher than those in Chinese cities and lower than that of the Chichi-jima Island, pointing to the formation of diacid during long range transport. The lowest values of adipic/azelaic (C6/C9) and phthalic/azelaic (Ph/C9) were observed as a result of the overwhelming biogenic emission of the precursors (e.g., unsaturated fatty acids) of azelaic acid in summer.In this study, we will also discuss the sources and transport pathways of diacids and related compounds resolved using a hybrid receptor model, potential source contribution function (PSCF) and model results will be compared with available in-situ observations in East Asia.

  17. Sulfuric Acid on Europa

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain.

    This image is based on data gathered by Galileo's near infrared mapping spectrometer.

    Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks.

    Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  18. Trans Fatty Acids

    NASA Astrophysics Data System (ADS)

    Doyle, Ellin

    1997-09-01

    Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.

  19. Gluconic acid production.

    PubMed

    Anastassiadis, Savas; Morgunov, Igor G

    2007-01-01

    Gluconic acid, the oxidation product of glucose, is a mild neither caustic nor corrosive, non toxic and readily biodegradable organic acid of great interest for many applications. As a multifunctional carbonic acid belonging to the bulk chemicals and due to its physiological and chemical characteristics, gluconic acid itself, its salts (e.g. alkali metal salts, in especially sodium gluconate) and the gluconolactone form have found extensively versatile uses in the chemical, pharmaceutical, food, construction and other industries. Present review article presents the comprehensive information of patent bibliography for the production of gluconic acid and compares the advantages and disadvantages of known processes. Numerous manufacturing processes are described in the international bibliography and patent literature of the last 100 years for the production of gluconic acid from glucose, including chemical and electrochemical catalysis, enzymatic biocatalysis by free or immobilized enzymes in specialized enzyme bioreactors as well as discontinuous and continuous fermentation processes using free growing or immobilized cells of various microorganisms, including bacteria, yeast-like fungi and fungi. Alternatively, new superior fermentation processes have been developed and extensively described for the continuous and discontinuous production of gluconic acid by isolated strains of yeast-like mold Aureobasidium pullulans, offering numerous advantages over the traditional discontinuous fungi processes.

  20. Strongly Acidic Auxin Indole-3-Methanesulfonic Acid

    PubMed Central

    Cohen, Jerry D.; Baldi, Bruce G.; Bialek, Krystyna

    1985-01-01

    A radiochemical synthesis is described for [14C]indole-3-methanesulfonic acid (IMS), a strongly acidic auxin analog. Techniques were developed for fractionation and purification of IMS using normal and reverse phase chromatography. In addition, the utility of both Fourier transform infrared spectrometry and fast atom bombardment mass spectrometry for analysis of IMS has been demonstrated. IMS was shown to be an active auxin, stimulating soybean hypocotyl elongation, bean first internode curvature, and ethylene production. IMS uptake by thin sections of soybean hypocotyl was essentially independent of solution pH and, when applied at a 100 micromolar concentration, IMS exhibited a basipetal polarity in its transport in both corn coleoptile and soybean hypocotyl sections. [14C]IMS should, therefore, be a useful compound to study fundamental processes related to the movement of auxins in plant tissues and organelles. PMID:16664007

  1. Aerobic catabolism of phenylacetic acid in Pseudomonas putida U: biochemical characterization of a specific phenylacetic acid transport system and formal demonstration that phenylacetyl-coenzyme A is a catabolic intermediate.

    PubMed Central

    Schleissner, C; Olivera, E R; Fernández-Valverde, M; Luengo, J M

    1994-01-01

    The phenylacetic acid transport system (PATS) of Pseudomonas putida U was studied after this bacterium was cultured in a chemically defined medium containing phenylacetic acid (PA) as the sole carbon source. Kinetic measurement was carried out, in vivo, at 30 degrees C in 50 mM phosphate buffer (pH 7.0). Under these conditions, the uptake rate was linear for at least 3 min and the value of Km was 13 microM. The PATS is an active transport system that is strongly inhibited by 2,4-dinitrophenol, 4-nitrophenol (100%), KCN (97%), 2-nitrophenol (90%), or NaN3 (80%) added at a 1 mM final concentration (each). Glucose or D-lactate (10 mM each) increases the PATS in starved cells (140%), whereas arsenate (20 mM), NaF, or N,N'-dicyclohexylcarbodiimide (1 mM) did not cause any effect. Furthermore, the PATS is insensitive to osmotic shock. These data strongly suggest that the energy for the PATS is derived only from an electron transport system which causes an energy-rich membrane state. The thiol-containing compounds mercaptoethanol, glutathione, and dithiothreitol have no significant effect on the PATS, whereas thiol-modifying reagents such as N-ethylmaleimide and iodoacetate strongly inhibit uptake (100 and 93%, respectively). Molecular analogs of PA with a substitution (i) on the ring or (ii) on the acetyl moiety or those containing (iii) a different ring but keeping the acetyl moiety constant inhibit uptake to different extents. None of the compounds tested significantly increase the PA uptake rate except adipic acid, which greatly stimulates it (163%). The PATS is induced by PA and also, gratuitously, by some phenyl derivatives containing an even number of carbon atoms on the aliphatic moiety (4-phenyl-butyric, 6-phenylhexanoic, and 8-phenyloctanoic acids). However, similar compounds with an odd number of carbon atoms (benzoic, 3-phenylpropionic, 5-phenylvaleric, 7-phenylheptanoic, and 9-phenylnonanoic acids) as well as many other PA derivatives do not induce the system

  2. Aminolevulinic Acid Topical

    MedlinePlus

    ... under the skin that result from exposure to sunlight and can develop into skin cancer) of the ... acid will make your skin very sensitive to sunlight (likely to get sunburn). Avoid exposure of treated ...

  3. Difficult Decisions: Acid Rain.

    ERIC Educational Resources Information Center

    Miller, John A.; Slesnick, Irwin L.

    1989-01-01

    Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)

  4. Folic acid - test

    MedlinePlus

    ... folic acid before and during pregnancy helps prevent neural tube defects, such as spina bifida. Women who ... take more if they have a history of neural tube defects in earlier pregnancies. Ask your provider ...

  5. Acid soldering flux poisoning

    MedlinePlus

    The harmful substances in soldering fluxes are called hydrocarbons. They include: Ammonium chloride Rosin Hydrochloric acid Zinc ... Lee DC. Hydrocarbons. In: Marx JA, Hockberger RS, Walls RM, et ... Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ...

  6. Amoxicillin and Clavulanic Acid

    MedlinePlus

    ... Amoxicillin is in a class of medications called penicillin-like antibiotics. It works by stopping the growth ... allergic to amoxicillin (Amoxil, Trimox, Wymox), clavulanic acid, penicillin, cephalosporins, or any other medications.tell your doctor ...

  7. Amino Acid Metabolism Disorders

    MedlinePlus

    ... acidemia? In ASA, the body can’t remove ammonia or a substance called argininosuccinic acid from the ... and children include: Breathing problems High levels of ammonia in the bloodIntense headache, especially after a high- ...

  8. [Hydrofluoric acid burns].

    PubMed

    Holla, Robin; Gorter, Ramon R; Tenhagen, Mark; Vloemans, A F P M Jos; Breederveld, Roelf S

    2016-01-01

    Hydrofluoric acid is increasingly used as a rust remover and detergent. Dermal contact with hydrofluoric acid results in a chemical burn characterized by severe pain and deep tissue necrosis. It may cause electrolyte imbalances with lethal consequences. It is important to identify high-risk patients. 'High risk' is defined as a total affected body area > 3% or exposure to hydrofluoric acid in a concentration > 50%. We present the cases of three male patients (26, 31, and 39 years old) with hydrofluoric acid burns of varying severity and describe the subsequent treatments. The application of calcium gluconate 2.5% gel to the skin is the cornerstone of the treatment, reducing pain as well as improving wound healing. Nails should be thoroughly inspected and possibly removed if the nail is involved, to ensure proper healing. In high-risk patients, plasma calcium levels should be evaluated and cardiac monitoring is indicated.

  9. Citric acid urine test

    MedlinePlus

    ... used to diagnose renal tubular acidosis and evaluate kidney stone disease. Normal Results The normal range is 320 ... tubular acidosis and a tendency to form calcium kidney stones. The following may decrease urine citric acid levels: ...

  10. Lead/acid batteries

    NASA Astrophysics Data System (ADS)

    Bullock, Kathryn R.

    Lead/acid batteries are produced in sizes from less than 1 to 3000 Ah for a wide variety of portable, industrial and automotive applications. Designs include Planté, Fauré or pasted, and tubular electrodes. In addition to the traditional designs which are flooded with sulfuric acid, newer 'valve-regulated" designs have the acid immolibized in a silica gel or absorbed in a porous glass separator. Development is ongoing worldwide to increase the specific power, energy and deep discharge cycle life of this commercially successful system to meet the needs of new applications such as electric vehicles, load leveling, and solar energy storage. The operating principles, current status, technical challenges and commercial impact of the lead/acid battery are reviewed.

  11. Amino Acids and Chirality

    NASA Technical Reports Server (NTRS)

    Cook, Jamie E.

    2012-01-01

    Amino acids are among the most heavily studied organic compound class in carbonaceous chondrites. The abundance, distributions, enantiomeric compositions, and stable isotopic ratios of amino acids have been determined in carbonaceous chondrites fi'om a range of classes and petrographic types, with interesting correlations observed between these properties and the class and typc of the chondritcs. In particular, isomeric distributions appear to correlate with parent bodies (chondrite class). In addition, certain chiral amino acids are found in enantiomeric excess in some chondrites. The delivery of these enantiomeric excesses to the early Earth may have contributed to the origin of the homochirality that is central to life on Earth today. This talk will explore the amino acids in carbonaceous chondritcs and their relevance to the origin of life.

  12. The linoleic acid and trans fatty acids of margarines.

    PubMed

    Beare-Rogers, J L; Gray, L M; Hollywood, R

    1979-09-01

    Fifty brands of margarine were analysed for cis-polyunsaturated acids by lipoxidase, for trans fatty acid by infared spectroscopy, and for fatty acid composition by gas-liquid chromatography. High concentrations of trans fatty acids tended to be associated with low concentrations of linoleic acid. Later analyses on eight of the brands, respresenting various proportions of linoleic to trans fatty acids, indicated that two of them contained still higher levels of trans fatty acids (greater than 60%) and negligible amounts of linoleic acid. It is proposed that margarine could be a vehicle for the distribution of some dietary linoleic acid and that the level of linoleic acid and the summation of the saturated plus trans fatty acids be known to ascertain nutritional characteristics.

  13. Method for isolating nucleic acids

    SciTech Connect

    Hurt, Jr., Richard Ashley; Elias, Dwayne A.

    2015-09-29

    The current disclosure provides methods and kits for isolating nucleic acid from an environmental sample. The current methods and compositions further provide methods for isolating nucleic acids by reducing adsorption of nucleic acids by charged ions and particles within an environmental sample. The methods of the current disclosure provide methods for isolating nucleic acids by releasing adsorbed nucleic acids from charged particles during the nucleic acid isolation process. The current disclosure facilitates the isolation of nucleic acids of sufficient quality and quantity to enable one of ordinary skill in the art to utilize or analyze the isolated nucleic acids for a wide variety of applications including, sequencing or species population analysis.

  14. [Acids in coffee. XI. The proportion of individual acids in the total titratable acid].

    PubMed

    Engelhardt, U H; Maier, H G

    1985-07-01

    22 acids in ground roast coffees and instant coffees were determined by GLC of their silyl derivatives (after preseparation by gel electrophoresis) or isotachophoresis. The contribution to the total acidity (which was estimated by titration to pH 8 after cation exchange of the coffee solutions) was calculated for each individual acid. The mentioned acids contribute with 67% (roast coffee) and 72% (instant coffee) to the total acidity. In the first place citric acid (12.2% in roast coffee/10.7% in instant coffee), acetic acid (11.2%/8.8%) and the high molecular weight acids (8%/9%) contribute to the total acidity. Also to be mentioned are the shares of chlorogenic acids (9%/4.8%), formic acid (5.3%/4.6%), quinic acid (4.7%/5.9%), malic acid (3.9%/3%) and phosphoric acid (2.5%/5.2%). A notable difference in the contribution to total acidity between roast and instant coffee was found for phosphoric acid and pyrrolidonecarboxylic acid (0.7%/1.9%). It can be concluded that those two acids are formed or released from e.g. their esters in higher amounts than other acids during the production of instant coffee.

  15. Acidification and Acid Rain

    NASA Astrophysics Data System (ADS)

    Norton, S. A.; Veselã½, J.

    2003-12-01

    Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw tremendous progress in the documentation of the chemistry of the atmosphere, precipitation, and the systems impacted by acid atmospheric deposition. Chronic acidification of ecosystems results in chemical changes to soil and to surface waters and groundwater as a result of reduction of base cation supply or an increase in acid (H+) supply, or both. The most fundamental changes during chronic acidification are an increase in exchangeable H+ or Al3+ (aluminum) in soils, an increase in H+ activity (˜concentration) in water in contact with soil, and a decrease in alkalinity in waters draining watersheds. Water draining from the soil is acidified and has a lower pH (=-log [H+]). As systems acidify, their biotic community changes.Acidic surface waters occur in many parts of the world as a consequence of natural processes and also due to atmospheric deposition of strong acid (e.g., Canada, Jeffries et al. (1986); the United Kingdom, Evans and Monteith (2001); Sweden, Swedish Environmental Protection Board (1986); Finland, Forsius et al. (1990); Norway, Henriksen et al. (1988a); and the United States (USA), Brakke et al. (1988)). Concern over acidification in the temperate regions of the northern hemisphere has been driven by the potential for accelerating natural acidification by pollution of the atmosphere with acidic or acidifying compounds. Atmospheric pollution ( Figure 1) has resulted in an increased flux of acid to and through ecosystems. Depending on the ability of an ecosystem to neutralize the increased flux of acidity, acidification may increase only imperceptibly or be accelerated at a rate that

  16. The second acidic constant of salicylic acid.

    PubMed

    Porto, Raffaella; De Tommaso, Gaetano; Furia, Emilia

    2005-01-01

    The second dissociation constant of salicylic acid (H2L) has been determined, at 25 degrees C, in NaCl ionic media by UV spectrophotometric measurements. The investigated ionic strength values were 0.16, 0.25, 0.50, 1.0, 2.0 and 3.0 M. The protolysis constants calculated at the different ionic strengths yielded, with the Specific Interaction Theory, the infinite dilution constant, log beta1(0) = 13.62 +/- 0.03, for the equilibrium L2- + H+ <==> HL-. The interaction coefficient between Na+ and L2-, b(Na+, L2-) = 0.02 +/- 0.07, has been also calculated.

  17. Differential activation of pregnane X receptor by carnosic acid, carnosol, ursolic acid, and rosmarinic acid.

    PubMed

    Seow, Chun Ling; Lau, Aik Jiang

    2017-03-10

    Pregnane X receptor (PXR) regulates the expression of many genes, including those involved in drug metabolism and transport, and has been linked to various diseases, including inflammatory bowel disease. In the present study, we determined whether carnosic acid and other chemicals in rosemary extract (carnosol, ursolic acid, and rosmarinic acid) are PXR activators. As assessed in dual-luciferase reporter gene assays, carnosic acid, carnosol, and ursolic acid, but not rosmarinic acid, activated human PXR (hPXR) and mouse PXR (mPXR), whereas carnosol and ursolic acid, but not carnosic acid or rosmarinic acid, activated rat PXR (rPXR). Dose-response experiments indicated that carnosic acid, carnosol, and ursolic acid activated hPXR with EC50 values of 0.79, 2.22, and 10.77μM, respectively. Carnosic acid, carnosol, and ursolic acid, but not rosmarinic acid, transactivated the ligand-binding domain of hPXR and recruited steroid receptor coactivator-1 (SRC-1), SRC-2, and SRC-3 to the ligand-binding domain of hPXR. Carnosic acid, carnosol, and ursolic acid, but not rosmarinic acid, increased hPXR target gene expression, as shown by an increase in CYP3A4, UGT1A3, and ABCB1 mRNA expression in LS180 human colon adenocarcinoma cells. Rosmarinic acid did not attenuate the extent of hPXR activation by rifampicin, suggesting it is not an antagonist of hPXR. Overall, carnosic acid, carnosol, and ursolic acid, but not rosmarinic acid, are hPXR agonists, and carnosic acid shows species-dependent activation of hPXR and mPXR, but not rPXR. The findings provide new mechanistic insight on the effects of carnosic acid, carnosol, and ursolic acid on PXR-mediated biological effects.

  18. Discovery of essential fatty acids

    PubMed Central

    Spector, Arthur A.; Kim, Hee-Yong

    2015-01-01

    Dietary fat was recognized as a good source of energy and fat-soluble vitamins by the first part of the 20th century, but fatty acids were not considered to be essential nutrients because they could be synthesized from dietary carbohydrate. This well-established view was challenged in 1929 by George and Mildred Burr who reported that dietary fatty acid was required to prevent a deficiency disease that occurred in rats fed a fat-free diet. They concluded that fatty acids were essential nutrients and showed that linoleic acid prevented the disease and is an essential fatty acid. The Burrs surmised that other unsaturated fatty acids were essential and subsequently demonstrated that linolenic acid, the omega-3 fatty acid analog of linoleic acid, is also an essential fatty acid. The discovery of essential fatty acids was a paradigm-changing finding, and it is now considered to be one of the landmark discoveries in lipid research. PMID:25339684

  19. Metabolic engineering of β-oxidation in Penicillium chrysogenum for improved semi-synthetic cephalosporin biosynthesis.

    PubMed

    Veiga, Tânia; Gombert, Andreas K; Landes, Nils; Verhoeven, Maarten D; Kiel, Jan A K W; Krikken, Arjen M; Nijland, Jeroen G; Touw, Hesselien; Luttik, Marijke A H; van der Toorn, John C; Driessen, Arnold J M; Bovenberg, Roel A L; van den Berg, Marco A; van der Klei, Ida J; Pronk, Jack T; Daran, Jean-Marc

    2012-07-01

    Industrial production of semi-synthetic cephalosporins by Penicillium chrysogenum requires supplementation of the growth media with the side-chain precursor adipic acid. In glucose-limited chemostat cultures of P. chrysogenum, up to 88% of the consumed adipic acid was not recovered in cephalosporin-related products, but used as an additional carbon and energy source for growth. This low efficiency of side-chain precursor incorporation provides an economic incentive for studying and engineering the metabolism of adipic acid in P. chrysogenum. Chemostat-based transcriptome analysis in the presence and absence of adipic acid confirmed that adipic acid metabolism in this fungus occurs via β-oxidation. A set of 52 adipate-responsive genes included six putative genes for acyl-CoA oxidases and dehydrogenases, enzymes responsible for the first step of β-oxidation. Subcellular localization of the differentially expressed acyl-CoA oxidases and dehydrogenases revealed that the oxidases were exclusively targeted to peroxisomes, while the dehydrogenases were found either in peroxisomes or in mitochondria. Deletion of the genes encoding the peroxisomal acyl-CoA oxidase Pc20g01800 and the mitochondrial acyl-CoA dehydrogenase Pc20g07920 resulted in a 1.6- and 3.7-fold increase in the production of the semi-synthetic cephalosporin intermediate adipoyl-6-APA, respectively. The deletion strains also showed reduced adipate consumption compared to the reference strain, indicating that engineering of the first step of β-oxidation successfully redirected a larger fraction of adipic acid towards cephalosporin biosynthesis.

  20. Acid Rain, pH & Acidity: A Common Misinterpretation.

    ERIC Educational Resources Information Center

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  1. [Lipid synthesis by an acidic acid tolerant Rhodotorula glutinis].

    PubMed

    Lin, Zhangnan; Liu, Hongjuan; Zhang, Jian'an; Wang, Gehua

    2016-03-01

    Acetic acid, as a main by-product generated in the pretreatment process of lignocellulose hydrolysis, significantly affects cell growth and lipid synthesis of oleaginous microorganisms. Therefore, we studied the tolerance of Rhodotorula glutinis to acetic acid and its lipid synthesis from substrate containing acetic acid. In the mixed sugar medium containing 6 g/L glucose and 44 g/L xylose, and supplemented with acetic acid, the cell growth was not:inhibited when the acetic acid concentration was below 10 g/L. Compared with the control, the biomass, lipid concentration and lipid content of R. glutinis increased 21.5%, 171% and 122% respectively when acetic acid concentration was 10 g/L. Furthermore, R. glutinis could accumulate lipid with acetate as the sole carbon source. Lipid concentration and lipid yield reached 3.20 g/L and 13% respectively with the initial acetic acid concentration of 25 g/L. The lipid composition was analyzed by gas chromatograph. The main composition of lipid produced with acetic acid was palmitic acid, stearic acid, oleic acid, linoleic acid and linolenic acid, including 40.9% saturated fatty acids and 59.1% unsaturated fatty acids. The lipid composition was similar to that of plant oil, indicating that lipid from oleaginous yeast R. glutinis had potential as the feedstock of biodiesel production. These results demonstrated that a certain concentration of acetic acid need not to be removed in the detoxification process when using lignocelluloses hydrolysate to produce microbial lipid by R. glutinis.

  2. Improving the pH-response of pHLIP insertion at tumor acidity for targeted drug delivery against cancer: Biophysical studies in model membranes and evaluations in cells

    NASA Astrophysics Data System (ADS)

    Onyango, Joab Otieno

    pH (Low) Insertion Peptide (pHLIP) possesses unique qualities that can be applied in cancer biology. It is a peptide that lives in three worlds: In State I, pHLIP exists as an unstructured monomer in solution at neutral pH; In State II, pHLIP partitions to the surface of a lipid bilayer at neutral pH; In State III, pHLIP inserts across the lipid bilayer by forming a transmembrane (TM) alpha helix under slightly acidic conditions (pH 6). These properties allow pHLIP to target acidosis (pH 6.5-7.0), a ubiquitous feature of solid tumors. Although pHLIP shows promise as a drug delivery vehicle, insertion properties such as pH50 (i.e. the pH at which 50% of pHLIP are inserted) and Hill coefficient must be tuned to improve tumor targeting and drug delivery in vivo. When TM region D14 and D25 residues were replaced with two glutamic acid residues as well as noncanonical amino acids such as alpha amino adipic acid (Aad) and gamma carboxyglutamic acid (Gla), we discovered pHLIP variants that possess a pH50 that can match tumor extracellular pH. pHLIP variants D25EE, Asp25Aad, and Asp14Gla/Asp25Aad, insert with pH50 of 6.60, 6.74, and 6.79, respectively. We also tuned pH-response (cooperativity of insertion) and we found that the Asp14Gla variant can insert into membrane with the sharpest transition observed so far for a pHLIP (i.e. over half pH unit vs. one pH unit for WT). Furthermore, we used turn-on fluorescence to evaluate the new variants in cancer cells. The most promising Asp25Aad pHLIP gave near theoretical maximum level of dequenching in cancerous A549 cells at pH 6.2 and 6.4, indicating a high level of plasma-membrane insertion. Under the same conditions, the `WT' and D25E pHLIP variants have low levels of plasma-membrane insertion in cells. Dequenching levels were low in non-cancerous HK2 cell line.

  3. Amino-acid contamination of aqueous hydrochloric acid.

    NASA Technical Reports Server (NTRS)

    Wolman, Y.; Miller, S. L.

    1971-01-01

    Considerable amino-acid contamination in commercially available analytical grade hydrochloric acid (37% HCl) was found. One bottle contained 8,300 nmol of amino-acids per liter. A bottle from another supplier contained 6,700 nmol per liter. The contaminants were mostly protein amino-acids and several unknowns. Data on the volatility of the amino-acids during HCl distillation were also obtained.

  4. Recurrent uric acid stones.

    PubMed

    Kamel, K S; Cheema-Dhadli, S; Shafiee, M A; Davids, M R; Halperin, M L

    2005-01-01

    A 46-year-old female had a history of recurrent uric acid stone formation, but the reason why uric acid precipitated in her urine was not obvious, because the rate of urate excretion was not high, urine volume was not low, and the pH in her 24-h urine was not low enough. In his discussion of the case, Professor McCance provided new insights into the pathophysiology of uric acid stone formation. He illustrated that measuring the pH in a 24-h urine might obscure the fact that the urine pH was low enough to cause uric acid to precipitate during most of the day. Because he found a low rate of excretion of NH(4)(+) relative to that of sulphate anions, as well as a high rate of citrate excretion, he speculated that the low urine pH would be due to a more alkaline pH in proximal convoluted tubule cells. He went on to suspect that there was a problem in our understanding of the function of renal medullary NH(3) shunt pathway, and he suggested that its major function might be to ensure a urine pH close to 6.0 throughout the day, to minimize the likelihood of forming uric acid kidney stones.

  5. Hydrogen production by fermentation using acetic acid and lactic acid.

    PubMed

    Matsumoto, Mitsufumi; Nishimura, Yasuhiko

    2007-03-01

    Microbial hydrogen production from sho-chu post-distillation slurry solution (slurry solution) containing large amounts of organic acids was investigated. The highest hydrogen producer, Clostridium diolis JPCC H-3, was isolated from natural environment and produced hydrogen at 6.03+/-0.15 ml from 5 ml slurry solution in 30 h. Interestingly, the concentration of acetic acid and lactic acid in the slurry solution decreased during hydrogen production. The substrates for hydrogen production by C. diolis JPCC H-3, in particular organic acids, were investigated in an artificial medium. No hydrogen was produced from acetic acid, propionic acid, succinic acid, or citric acid on their own. Hydrogen and butyric acid were produced from a mixture of acetic acid and lactic acid, showing that C. diolis. JPCC H-3 could produce hydrogen from acetic acid and lactic acid. Furthermore, calculation of the Gibbs free energy strongly suggests that this reaction would proceed. In this paper, we describe for the first time microbial hydrogen production from acetic acid and lactic acid by fermentation.

  6. A Demonstration of Acid Rain

    ERIC Educational Resources Information Center

    Fong, Man Wai

    2004-01-01

    A demonstration showing acid rain formation is described. Oxides of sulfur and nitrogen that result from the burning of fossil fuels are the major pollutants of acid rain. In this demonstration, SO[subscript 2] gas is produced by the burning of matches. An acid-base indicator will show that the dissolved gas turns an aqueous solution acidic.

  7. Biodegradation of Cyanuric Acid

    PubMed Central

    Saldick, Jerome

    1974-01-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO2 and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand. PMID:4451360

  8. [Aristolochic acid nephropathy].

    PubMed

    Witkowicz, Joanna

    2009-01-01

    Aristolochic acid nephropathy is a chronic, fibrosing, interstitial nephritis caused by aristolochic acid (AA), which is a component of the plants of Aristolochiacae family. It was first reported in 1993, in Belgium as a Chinese herb nephropathy, in patients who received a slimming regimen containing AA. The term aristolochic acid nephropathy also includes Balcan endemic nephropathy and other endemic tubulointerstitial fibrosis. Moreover, AA is a human carcinogen which induces urothelial cancer. The AA-containing herbs are banned in many countries and FDA published the warnings concerning the safety of AA-containing botanical remedies in 2000. Regarding the increasing interest in herbal medicines, uncontrolled access to botanical remedies and replacement of one herb by another AA-containing compounds makes thousands of people all around the world at risk of this grave disease.

  9. Calorimetry of Nucleic Acids.

    PubMed

    Rozners, Eriks; Pilch, Daniel S; Egli, Martin

    2015-12-01

    This unit describes the application of calorimetry to characterize the thermodynamics of nucleic acids, specifically, the two major calorimetric methodologies that are currently employed: differential scanning (DSC) and isothermal titration calorimetry (ITC). DSC is used to study thermally induced order-disorder transitions in nucleic acids. A DSC instrument measures, as a function of temperature (T), the excess heat capacity (C(p)(ex)) of a nucleic acid solution relative to the same amount of buffer solution. From a single curve of C(p)(ex) versus T, one can derive the following information: the transition enthalpy (ΔH), entropy (ΔS), free energy (ΔG), and heat capacity (ΔCp); the state of the transition (two-state versus multistate); and the average size of the molecule that melts as a single thermodynamic entity (e.g., the duplex). ITC is used to study the hybridization of nucleic acid molecules at constant temperature. In an ITC experiment, small aliquots of a titrant nucleic acid solution (strand 1) are added to an analyte nucleic acid solution (strand 2), and the released heat is monitored. ITC yields the stoichiometry of the association reaction (n), the enthalpy of association (ΔH), the equilibrium association constant (K), and thus the free energy of association (ΔG). Once ΔH and ΔG are known, ΔS can also be derived. Repetition of the ITC experiment at a number of different temperatures yields the ΔCp for the association reaction from the temperature dependence of ΔH.

  10. Acid rain in Asia

    NASA Astrophysics Data System (ADS)

    Bhatti, Neeloo; Streets, David G.; Foell, Wesley K.

    1992-07-01

    Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging perception that the problem in these Western nations is nearing solution. The situation in the developing world, particularly in Asia, is much bleaker. Given the policies of many Asian nations to achieve levels of development comparable with the industrialized world—which necessitate a significant expansion of energy consumption (most derived from indigenous coal reserves)—the potential for the formation of, and damage from, acid deposition in these developing countries is very high. This article delineates and assesses the emissions patterns, meteorology, physical geology, and biological and cultural resources present in various Asian nations. Based on this analysis and the risk factors to acidification, it is concluded that a number of areas in Asia are currently vulnerable to acid rain. These regions include Japan, North and South Korea, southern China, and the mountainous portions of Southeast Asia and southwestern India. Furthermore, with accelerated development (and its attendant increase in energy use and production of emissions of acid deposition precursors) in many nations of Asia, it is likely that other regions will also be affected by acidification in the near future. Based on the results of this overview, it is clear that acid deposition has significant potential to impact the Asian region. However, empirical evidence is urgently needed to confirm this and to provide early warning of increases in the magnitude and spread of acid deposition and its effects throughout this part of the world.

  11. Ethylenediaminetetraacetic acid in endodontics.

    PubMed

    Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid

    2013-09-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for its usage are presented.

  12. Ethylenediaminetetraacetic acid in endodontics

    PubMed Central

    Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid

    2013-01-01

    Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for its usage are presented. PMID:24966721

  13. A luminescent coordination polymer based on a π-conjugated ligand: Syntheses, structure and luminescent property

    NASA Astrophysics Data System (ADS)

    Li, Dan-Yang; Xie, Hua; Yao, Xiao-Qiang; Ma, Heng-Chang; Lei, Zi-Qiang; Liu, Jia-Cheng

    2017-04-01

    A new cadmium coordination polymer [Cd(DPFE)(adip)0.5(NO3)]n (1) has been synthesized hydrothermally from the self-assembly of the Cd2+ ion with a new π-conjugated rigid ligand DPFE and the adipic acid, where DPFE = 2,7-di(pyridin-4-yl)-9H-fluorene and H2adip = adipic acid. The structure of 1 was full characterized by elemental analysis, FT-IR spectroscopy and single crystal X-ray diffraction. Structural analysis reveals compound 1 is a dinuclear Cd(II) based two-dimensional (4,4) layer and two kinds of strong intramolecular π-π stacking interactions exist between pyridyl rings and benzene rings. In addition, the thermogravimetric analysis and solid-state luminescent properties have also been investigated.

  14. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    ERIC Educational Resources Information Center

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  15. Comparison of Buffer Effect of Different Acids During Sandstone Acidizing

    NASA Astrophysics Data System (ADS)

    Umer Shafiq, Mian; Khaled Ben Mahmud, Hisham; Hamid, Mohamed Ali

    2015-04-01

    The most important concern of sandstone matrix acidizing is to increase the formation permeability by removing the silica particles. To accomplish this, the mud acid (HF: HCl) has been utilized successfully for many years to stimulate the sandstone formations, but still it has many complexities. This paper presents the results of laboratory investigations of different acid combinations (HF: HCl, HF: H3PO4 and HF: HCOOH). Hydrofluoric acid and fluoboric acid are used to dissolve clays and feldspar. Phosphoric and formic acids are added as a buffer to maintain the pH of the solution; also it allows the maximum penetration of acid into the core sample. Different tests have been performed on the core samples before and after the acidizing to do the comparative study on the buffer effect of these acids. The analysis consists of permeability, porosity, color change and pH value tests. There is more increase in permeability and porosity while less change in pH when phosphoric and formic acids were used compared to mud acid. From these results it has been found that the buffer effect of phosphoric acid and formic acid is better than hydrochloric acid.

  16. Oxalic acid excretion after intravenous ascorbic acid administration.

    PubMed

    Robitaille, Line; Mamer, Orval A; Miller, Wilson H; Levine, Mark; Assouline, Sarit; Melnychuk, David; Rousseau, Caroline; Hoffer, L John

    2009-02-01

    Ascorbic acid is frequently administered intravenously by alternative health practitioners and, occasionally, by mainstream physicians. Intravenous administration can greatly increase the amount of ascorbic acid that reaches the circulation, potentially increasing the risk of oxalate crystallization in the urinary space. To investigate this possibility, we developed gas chromatography mass spectrometry methodology and sampling and storage procedures for oxalic acid analysis without interference from ascorbic acid and measured urinary oxalic acid excretion in people administered intravenous ascorbic acid in doses ranging from 0.2 to 1.5 g/kg body weight. In vitro oxidation of ascorbic acid to oxalic acid did not occur when urine samples were brought immediately to pH less than 2 and stored at -30 degrees C within 6 hours. Even very high ascorbic acid concentrations did not interfere with the analysis when oxalic acid extraction was carried out at pH 1. As measured during and over the 6 hours after ascorbic acid infusions, urinary oxalic acid excretion increased with increasing doses, reaching approximately 80 mg at a dose of approximately 100 g. We conclude that, when studied using correct procedures for sample handling, storage, and analysis, less than 0.5% of a very large intravenous dose of ascorbic acid is recovered as urinary oxalic acid in people with normal renal function.

  17. [Studies on interaction of acid-treated nanotube titanic acid and amino acids].

    PubMed

    Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang

    2010-06-01

    Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination.

  18. Alkyl phosphonic acids and sulfonic acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Cooper, George W.; Onwo, Wilfred M.; Cronin, John R.

    1992-01-01

    Homologous series of alkyl phosphonic acids and alkyl sulfonic acids, along with inorganic orthophosphate and sulfate, are identified in water extracts of the Murchison meteorite after conversion to their t-butyl dimethylsilyl derivatives. The methyl, ethyl, propyl, and butyl compounds are observed in both series. Five of the eight possible alkyl phosphonic acids and seven of the eight possible alkyl sulfonic acids through C4 are identified. Abundances decrease with increasing carbon number as observed of other homologous series indigenous to Murchison. Concentrations range downward from approximately 380 nmol/gram in the alkyl sulfonic acid series, and from 9 nmol/gram in the alkyl phosphonic acid series.

  19. Effect of domoic acid on brain amino acid levels.

    PubMed

    Durán, R; Arufe, M C; Arias, B; Alfonso, M

    1995-03-01

    The administration of Domoic Acid (Dom) in a 0.2 mg/kg i.p. dose induces changes in the levels of amino acids of neurochemical interest (Asp, Glu, Gly, Tau, Ala, GABA) in different rat brain regions (hypothalamus, hippocampus, amygdala, striatum, cortex and midbrain). The most affected amino acid is the GABA, the main inhibitory amino acid neurotransmitter, whereas glutamate, the main excitatory amino acid, is not affected. The rat brain regions that seem to be the main target of the Dom action belong to the limbic system (hippocampus, amygdala). The possible implication of the amino acids in the actions of Dom is also discussed.

  20. Hydrofluoric acid poisoning

    MedlinePlus

    Chemical Emergencies: Case Definition: Hydrofluoric Acid . Centers for Disease Control and Prevention, U.S. Dept of Health and Human Services; 2005. Goldfrank LR, ed. Goldfrank's Toxicologic Emergencies . 8th ed. New York, NY: McGraw Hill; 2006. Wax PM, Young A. ...