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Sample records for 1-propanol

  1. 40 CFR 721.525 - 1-propanol, 3-propoxy-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-propanol, 3-propoxy-. 721.525... Substances § 721.525 1-propanol, 3-propoxy-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-propanol, 3-propoxy- (PMN P-00-0827; CAS No....

  2. 40 CFR 721.525 - 1-propanol, 3-propoxy-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 1-propanol, 3-propoxy-. 721.525... Substances § 721.525 1-propanol, 3-propoxy-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-propanol, 3-propoxy- (PMN P-00-0827; CAS No....

  3. 40 CFR 721.8175 - 1-Propanol, 3-mercapto-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-Propanol, 3-mercapto-. 721.8175... Substances § 721.8175 1-Propanol, 3-mercapto-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-propanol, 3-mercapto (PMN P-85-433; CAS No....

  4. 40 CFR 721.8175 - 1-Propanol, 3-mercapto-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 1-Propanol, 3-mercapto-. 721.8175... Substances § 721.8175 1-Propanol, 3-mercapto-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as 1-propanol, 3-mercapto (PMN P-85-433; CAS No....

  5. Dehydratase mediated 1-propanol production in metabolically engineered Escherichia coli

    PubMed Central

    2011-01-01

    Background With the increasing consumption of fossil fuels, the question of meeting the global energy demand is of great importance in the near future. As an effective solution, production of higher alcohols from renewable sources by microorganisms has been proposed to address both energy crisis and environmental concerns. Higher alcohols contain more than two carbon atoms and have better physiochemical properties than ethanol as fuel substitutes. Results We designed a novel 1-propanol metabolic pathway by expanding the well-known 1,2-propanediol pathway with two more enzymatic steps catalyzed by a 1,2-propanediol dehydratase and an alcohol dehydrogenase. In order to engineer the pathway into E. coli, we evaluated the activities of eight different methylglyoxal synthases which play crucial roles in shunting carbon flux from glycolysis towards 1-propanol biosynthesis, as well as two secondary alcohol dehydrogenases of different origins that reduce both methylglyoxal and hydroxyacetone. It is evident from our results that the most active enzymes are the methylglyoxal synthase from Bacillus subtilis and the secondary alcohol dehydrogenase from Klebsiella pneumoniae, encoded by mgsA and budC respectively. With the expression of these two genes and the E. coli ydjG encoding methylglyoxal reductase, we achieved the production of 1,2-propanediol at 0.8 g/L in shake flask experiments. We then characterized the catalytic efficiency of three different diol dehydratases on 1,2-propanediol and identified the optimal one as the 1,2-propanediol dehydratase from Klebsiella oxytoca, encoded by the operon ppdABC. Co-expressing this enzyme with the above 1,2-propanediol pathway in wild type E. coli resulted in the production of 1-propanol at a titer of 0.25 g/L. Conclusions We have successfully established a new pathway for 1-propanol production by shunting the carbon flux from glycolysis. To our knowledge, it is the first time that this pathway has been utilized to produce 1

  6. Fragrance material review on 3-phenyl-1-propanol.

    PubMed

    Bhatia, S P; Wellington, G A; Cocchiara, J; Lalko, J; Letizia, C S; Api, A M

    2011-12-01

    A toxicologic and dermatologic review of 3-phenyl-1-propanol when used as a fragrance ingredient is presented. 3-Phenyl-1-propanol is a member of the fragrance structural group cinnamyl phenylpropyl compounds. The common characteristic structural element of cinnamyl phenylpropyl materials is an aryl substituted primary alcohol/aldehyde/ester. They are simple aromatic compounds with saturated propyl or unsaturated propenyl side chains containing a primary oxygenated functional group which has little toxic potential. 3-Phenyl-1-propyl derivatives participate in the same beta-oxidation pathways as do their parent cinnamic acid derivatives. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for 3-phenyl-1-propanol was evaluated then summarized and includes physical properties, acute toxicity, skin irritation, skin sensitization, in vitro skin absorption and mutagenicity. A safety assessment of all cinnamyl phenylpropyl compounds will be published simultaneously with this document; please refer to Belsito et al. (2011) for an overall assessment of the safe use of this material and all cinnamyl phenylpropyl materials in fragrances (Belsito, D., Bickers, D., Bruze, M., Dagli, M.L., Fryer, A., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2011. A toxicologic and dermatologic assessment of cinnamyl phenylpropyl compounds when used as fragrance ingredients.).

  7. Densities and refractive indices for acetone + methanol + 1-propanol at 298.15 K

    SciTech Connect

    Iglesias, M.; Orge, B.; Tojo, J.

    1996-03-01

    Densities and refractive indices at 298.15 K for acetone + methanol + 1-propanol and the binary acetone + 1-propanol and methanol + 1-propanol mixtures have been measured as a function of the mole fraction at atmospheric pressure. Parameters of analytical expressions which represent the composition dependences of physical properties and excess values are reported. The refractive index results are compared with estimation methods. The excess properties for the ternary mixture are compared with those estimated on the basis of binary property contributions.

  8. Manipulating the sleeping beauty mutase operon for the production of 1-propanol in engineered Escherichia coli

    PubMed Central

    2013-01-01

    Background While most resources in biofuels were directed towards implementing bioethanol programs, 1-propanol has recently received attention as a promising alternative biofuel. Nevertheless, no microorganism has been identified as a natural 1-propanol producer. In this study, we manipulated a novel metabolic pathway for the synthesis of 1-propanol in the genetically tractable bacterium Escherichia coli. Results E. coli strains capable of producing heterologous 1-propanol were engineered by extending the dissimilation of succinate via propionyl-CoA. This was accomplished by expressing a selection of key genes, i.e. (1) three native genes in the sleeping beauty mutase (Sbm) operon, i.e. sbm-ygfD-ygfG from E. coli, (2) the genes encoding bifunctional aldehyde/alcohol dehydrogenases (ADHs) from several microbial sources, and (3) the sucCD gene encoding succinyl-CoA synthetase from E. coli. Using the developed whole-cell biocatalyst under anaerobic conditions, production titers up to 150 mg/L of 1-propanol were obtained. In addition, several genetic and chemical effects on the production of 1-propanol were investigated, indicating that certain host-gene deletions could abolish 1-propanol production as well as that the expression of a putative protein kinase (encoded by ygfD/argK) was crucial for 1-propanol biosynthesis. Conclusions The study has provided a novel route for 1-propanol production in E. coli, which is subjected to further improvement by identifying limiting conversion steps, shifting major carbon flux to the productive pathway, and optimizing gene expression and culture conditions. PMID:24074355

  9. Dielectric relaxation and crystallization of nanophase separated 1-propanol-isoamylbromide mixture.

    PubMed

    Power, G; Vij, J K; Johari, G P

    2007-09-01

    The effects of liquid-liquid phase separation on molecular relaxation of an apparently homogeneous mixture of 1-propanol and isoamylbromide has been studied by dielectric spectroscopy over a broad frequency and temperature range, and its crystallization kinetics investigated in real time. The mixture shows two widely separated relaxation processes, as before, with the faster relaxation due to the orientational diffusion of isoamylbromide and the slower due to that of 1-propanol. In the mixture, the scaled contribution to permittivity from orientation polarization, Deltaepsilon, of isoamylbromide is about the same as in the pure state, but that of 1-propanol decreases by a factor of approximately 3 at 120 K. As the temperature is decreased, this difference remains constant. The relaxation time, tau, of isoamylbromide and its distribution parameter remains the same as for the pure liquid, but that of 1-propanol is longer and increases with decrease in T, becoming approximately 130 times the pure liquid's value at 119 K. This is in contrast to the finding for an isomeric heptanol, whose tau had decreased. Extrapolation suggests that at T>151 K, tau of 1-propanol in the mixture may become less than that in the pure liquid (the isoamylbromide component crystallizes before this temperature could be reached). This indicates that Tg corresponding to tau of 10(3) s for 1-propanol in the mixture would be higher than in the pure liquid. Crystallization of the two components in the mixture occurs at different rates and 1-propanol remains partially uncrystallized while isoamylbromide completely crystallizes. tau of any remaining liquid isoamylbromide does not change in the presence of crystallized states while tau of residual liquid 1-propanol in the mixture is reduced. The mixture phase separates in submicron or nanosize aggregates of the alcohol in isoamylbromide, without affecting the latter's relaxation kinetics, while its own epsilon(s) decreases and tau increases

  10. Dehydration pathways of 1-propanol on HZSM-5 in the presence and absence of water

    SciTech Connect

    Zhi, Yuchun; Shi, Hui; Mu, Linyu; Liu, Yue; Mei, Donghai; Camaioni, Donald M.; Lercher, Johannes A.

    2015-12-23

    The Brønsted acid-catalyzed gas-phase dehydration of 1-propanol (0.075-4 kPa) was studied on zeolite H-MFI (Si/Al = 26, containing minimal amounts of extraframework Al moieties) in the absence and presence of co-fed water (0-2.5 kPa) at 413-443 K. It is shown that propene can be formed from monomeric and dimeric adsorbed 1-propanol. The stronger adsorption of 1-propanol relative to water indicates that the reduced dehydration rates in the presence of water are not a consequence of the competitive adsorption between 1-propanol and water. Instead, the deleterious effect is related to the different extents of stabilization of adsorbed intermediates and the relevant elimination/substitution transition states by water. Water stabilizes the adsorbed 1-propanol monomer significantly more than the elimination transition state, leading to a higher activation barrier and a greater entropy gain for the rate-limiting step, which eventually leads to propene. In a similar manner, an excess of 1-propanol stabilizes the adsorbed state of 1-propanol more than the elimination transition state. In comparison with the monomer-mediated pathway, adsorbed dimer and the relevant transition states for propene and ether formation are similarly, while less effectively, stabilized by intrazeolite water molecules. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences, and Biosciences, and was performed in part using the Molecular Sciences Computing Facility (MSCF) in the William R. Wiley Environmental Molecular Sciences Laboratory, a DOE national scientific user facility sponsored by the DOE’s Office of Biological and Environmental Research and located and the Pacific Northwest National Laboratory (PNNL). PNNL is operated by Battelle for DOE.

  11. Solubilities of carbon dioxide in aqueous mixtures of diethanolamine and 2-amino-2-methyl-1-propanol

    SciTech Connect

    Seo, D.J.; Hong, W.H.

    1996-03-01

    The gas solubility of CO{sub 2} has been measured in aqueous mixtures of diethanolamine and 2-amino-2-methyl-1-propanol at (40, 60, and 80) C and in the pressure range (10 to 300) kPa. The concentrations of the amine mixtures were 6 mass % diethanolamine (DEA) + 24 mass % 2-amino-2-methyl-1-propanol (AMP), 12 mass % DEA + 18 mass % AMP, and 18 mass % DEA + 12 mass % AMP. The solubilities show a systematic change as the composition of the aqueous mixtures varies.

  12. 40 CFR 721.10117 - Heteromonocyclo-beta-(2,4-dichlorophenyl) -1-propanol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Heteromonocyclo-beta-(2,4... Significant New Uses for Specific Chemical Substances § 721.10117 Heteromonocyclo-beta-(2,4-dichlorophenyl) -1... substance identified generically as heteromonocyclo-beta-(2,4-dichlorophenyl) -1-propanol (PMN P-04-776)...

  13. 40 CFR 721.10117 - Heteromonocyclo-beta-(2,4-dichlorophenyl) -1-propanol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Heteromonocyclo-beta-(2,4... Significant New Uses for Specific Chemical Substances § 721.10117 Heteromonocyclo-beta-(2,4-dichlorophenyl) -1... substance identified generically as heteromonocyclo-beta-(2,4-dichlorophenyl) -1-propanol (PMN P-04-776)...

  14. 40 CFR 721.8250 - 1-Propanol, 3,3′-oxybis[2,2-bis(bromomethyl)-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-Propanol, 3,3â²-oxybis[2,2-bis... Specific Chemical Substances § 721.8250 1-Propanol, 3,3′-oxybis[2,2-bis(bromomethyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

  15. 40 CFR 721.8250 - 1-Propanol, 3,3′-oxybis[2,2-bis(bromomethyl)-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 1-Propanol, 3,3â²-oxybis[2,2-bis... Specific Chemical Substances § 721.8250 1-Propanol, 3,3′-oxybis[2,2-bis(bromomethyl)-. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as...

  16. Effect of calcium chloride on the isobaric vapor-liquid equilibrium of 1-propanol + water

    SciTech Connect

    Iliuta, M.C.; Thyrion, F.C.; Landauer, O.M.

    1996-05-01

    The effect of calcium chloride at salt mole fractions from 0.02 to saturation on the vapor-liquid equilibrium (VLE) of 1-propanol + water has been studied at 101.32 kPa using a modified Othmer equilibrium still. The salt exhibited a salting-out effect of the alcohol over the whole range of liquid composition, the azeotrope being eliminated at salt mole fractions greater than 0.080. A liquid phase splitting into two immiscible liquid phases on the whole range of salt concentration and over a liquid range of about 0.01--0.54 1-propanol mole fraction (salt-free basis) was observed. The results were compared with the values predicted from the extended UNIQUAC models of Sander et al. and Macedo et al. and the modified UNIFAC group-contribution model of Kikic et al.

  17. Metabolic engineering of Escherichia coli for the production of 1-propanol.

    PubMed

    Choi, Yong Jun; Park, Jin Hwan; Kim, Tae Yong; Lee, Sang Yup

    2012-09-01

    An engineered Escherichia coli strain that produces 1-propanol under aerobic condition was developed based on an L-threonine-overproducing E. coli strain. First, a feedback resistant ilvA gene encoding threonine dehydratase was introduced and the competing metabolic pathway genes were deleted. Further engineering was performed by overexpressing the cimA gene encoding citramalate synthase and the ackA gene encoding acetate kinase A/propionate kinase II, introducing a modified adhE gene encoding an aerobically functional AdhE, and by deleting the rpoS gene encoding the stationary phase sigma factor. Fed-batch culture of the final engineered strain harboring pBRthrABC-tac-cimA-tac-ackA and pTacDA-tac-adhE(mut) allowed production of 10.8 g L(-1) of 1-propanol with the yield and productivity of 0.107 g g(-1) and 0.144 g L(-1) h(-1), respectively, from 100 g L(-1) of glucose, and 10.3 g L(-1) of 1-propanol with the yield and productivity of 0.259 g g(-1) and 0.083 g L(-1) h(-1), respectively, from 40 g L(-1) glycerol. PMID:22871504

  18. Optimization of lipase-catalyzed enantioselective production of 1-phenyl 1-propanol using response surface methodology.

    PubMed

    Soyer, Asli; Bayraktar, Emine; Mehmetoglu, Ulku

    2010-01-01

    Optically active 1-phenyl 1-propanol is used as a chiral building block and synthetic intermediate in the pharmaceutical industries. In this study, the enantioselective production of 1-phenyl 1-propanol was investigated systematically using response surface methodology (RSM). Before RSM was applied, the effects of the enzyme source, the type of acyl donor, and the type of solvent on the kinetic resolution of 1-phenyl 1-propanol were studied. The best results were obtained with Candida antartica lipase (commercially available as Novozym 435), vinyl laurate as the acyl donor, and isooctane as the solvent. In the RSM, substrate concentration, molar ratio of acyl donor to the substrate, amount of enzyme, temperature, and stirring rate were chosen as independent variables. The predicted optimum conditions for a higher enantiomeric excess (ee) were as follows: substrate concentration, 233 mM; molar ratio of acyl donor to substrate, 1.5; enzyme amount, 116 mg; temperature, 47 °C; and stirring rate, 161 rpm. A verification experiment conducted at these optimized conditions for maximum ee yielded 91% for 3 hr, which is higher than the predicted value of 83%. The effect of microwave on the ee was also investigated and ee reached 87% at only 5 min. PMID:21108142

  19. Liquid 1-propanol studied by neutron scattering, near-infrared, and dielectric spectroscopy.

    PubMed

    Sillrén, P; Matic, A; Karlsson, M; Koza, M; Maccarini, M; Fouquet, P; Götz, M; Bauer, Th; Gulich, R; Lunkenheimer, P; Loidl, A; Mattsson, J; Gainaru, C; Vynokur, E; Schildmann, S; Bauer, S; Böhmer, R

    2014-03-28

    Liquid monohydroxy alcohols exhibit unusual dynamics related to their hydrogen bonding induced structures. The connection between structure and dynamics is studied for liquid 1-propanol using quasi-elastic neutron scattering, combining time-of-flight and neutron spin-echo techniques, with a focus on the dynamics at length scales corresponding to the main peak and the pre-peak of the structure factor. At the main peak, the structural relaxation times are probed. These correspond well to mechanical relaxation times calculated from literature data. At the pre-peak, corresponding to length scales related to H-bonded structures, the relaxation times are almost an order of magnitude longer. According to previous work [C. Gainaru, R. Meier, S. Schildmann, C. Lederle, W. Hiller, E. Rössler, and R. Böhmer, Phys. Rev. Lett. 105, 258303 (2010)] this time scale difference is connected to the average size of H-bonded clusters. The relation between the relaxation times from neutron scattering and those determined from dielectric spectroscopy is discussed on the basis of broad-band permittivity data of 1-propanol. Moreover, in 1-propanol the dielectric relaxation strength as well as the near-infrared absorbance reveal anomalous behavior below ambient temperature. A corresponding feature could not be found in the polyalcohols propylene glycol and glycerol.

  20. Optimization of lipase-catalyzed enantioselective production of 1-phenyl 1-propanol using response surface methodology.

    PubMed

    Soyer, Asli; Bayraktar, Emine; Mehmetoglu, Ulku

    2010-01-01

    Optically active 1-phenyl 1-propanol is used as a chiral building block and synthetic intermediate in the pharmaceutical industries. In this study, the enantioselective production of 1-phenyl 1-propanol was investigated systematically using response surface methodology (RSM). Before RSM was applied, the effects of the enzyme source, the type of acyl donor, and the type of solvent on the kinetic resolution of 1-phenyl 1-propanol were studied. The best results were obtained with Candida antartica lipase (commercially available as Novozym 435), vinyl laurate as the acyl donor, and isooctane as the solvent. In the RSM, substrate concentration, molar ratio of acyl donor to the substrate, amount of enzyme, temperature, and stirring rate were chosen as independent variables. The predicted optimum conditions for a higher enantiomeric excess (ee) were as follows: substrate concentration, 233 mM; molar ratio of acyl donor to substrate, 1.5; enzyme amount, 116 mg; temperature, 47 °C; and stirring rate, 161 rpm. A verification experiment conducted at these optimized conditions for maximum ee yielded 91% for 3 hr, which is higher than the predicted value of 83%. The effect of microwave on the ee was also investigated and ee reached 87% at only 5 min.

  1. Dissociative ionization of the 1-propanol dimer in a supersonic expansion under tunable synchrotron VUV radiation.

    PubMed

    Tao, Yanmin; Hu, Yongjun; Xiao, Weizhan; Guan, Jiwen; Liu, Fuyi; Shan, Xiaobin; Sheng, Liusi

    2016-05-11

    Photoionization and dissociation of the 1-propanol dimer and subsequent fragmentations have been investigated by synchrotron vacuum ultraviolet (VUV) photoionization mass spectrometry and theoretical calculations. Besides the protonated monomer cation (C3H7OH)·H(+) (m/z = 61) and Cα-Cβ bond cleavage fragment CH2O·(C3H7OH)H(+) (m/z = 91), the measured mass spectrum at an incident photon energy of 13 eV suggests a new dissociation channel resulting in the formation of the (C3H7OH)·H(+)·(C2H5OH) (m/z = 107) fragment. The appearance energies of the fragments (C3H7OH)·H(+), CH2O·(C3H7OH)H(+) and (C3H7OH)·H(+)·(C2H5OH) are measured at 10.05 ± 0.05 eV, 9.48 ± 0.05 eV, and 12.8 ± 0.1 eV, respectively, by scanning photoionization efficiency (PIE) spectra. The 1-propanol ion fragments as a function of VUV photon energy were interpreted with the aid of theoretical calculations. In addition to O-H and Cα-Cβ bond cleavage, a new dissociation channel related to Cβ-Cγ bond cleavage opens. In this channel, molecular rearrangement (proton transfer and hydrogen transfer after surmounting an energy barrier) gives rise to the generated complex, which then dissociates to produce the mixed propanol/ethanol proton bound cation (C3H7OH)·H(+)·(C2H5OH). This new dissociation channel has not been reported in previous studies of ethanol and acetic acid dimers. The photoionization and dissociation processes of the 1-propanol dimer are described in the photon energy range of 9-15 eV. PMID:27141555

  2. Fluid Phase Topology of Benzene + Cyclohexane + 1-Propanol at 101.3 kPa

    NASA Astrophysics Data System (ADS)

    Andrade, R. S.; Iglesias, M.

    2015-07-01

    Isobaric vapor-liquid equilibria for the benzene + cyclohexane + 1-propanol ternary mixture were experimentally investigated at atmospheric pressure. Data were tested and considered thermodynamically consistent by means of the McDermott and Ellis method. The experimental results showed that this ternary mixture is completely miscible and exhibits three binary minimum homogeneous azeotropes and a ternary minimum azeotrope at the studied conditions. Satisfactory results were obtained for correlation of equilibrium compositions with the UNIQUAC equation and also for prediction with the UNIFAC method. In both cases, low root-mean-square deviations of the vapor mole fraction and temperature were calculated. The capability of 1-propanol as a modified distillation agent at atmospheric conditions is discussed in terms of thermodynamic topological analysis. However, because of the complex topology of the ternary mixture, it leads to a distillation scheme with two columns specifying ternary azeotrope recycling and difficult operation. Thus, this compound is not recommended as a separation agent for the binary benzene + cyclohexane azeotrope.

  3. Homogeneous nucleation rate measurements of 1-propanol in helium: the effect of carrier gas pressure.

    PubMed

    Brus, David; Zdímal, Vladimír; Stratmann, Frank

    2006-04-28

    Kinetics of homogeneous nucleation in supersaturated vapor of 1-propanol was studied using an upward thermal diffusion cloud chamber. Helium was used as a noncondensable carrier gas and the influence of its pressure on observed nucleation rates was investigated. The isothermal nucleation rates were determined by a photographic method that is independent on any nucleation theory. In this method, the trajectories of growing droplets are recorded using a charge coupled device camera and the distribution of local nucleation rates is determined by image analysis. The nucleation rate measurements of 1-propanol were carried out at four isotherms 260, 270, 280, and 290 K. In addition, the pressure dependence was investigated on the isotherms 290 K (50, 120, and 180 kPa) and 280 K (50 and 120 kPa). The isotherm 270 K was measured at 25 kPa and the isotherm 260 K at 20 kPa. The experiments confirm the earlier observations from several thermal diffusion chamber investigations that the homogeneous nucleation rate of 1-propanol tends to increase with decreasing total pressure in the chamber. In order to reduce the possibility that the observed phenomenon is an experimental artifact, connected with the generally used one-dimensional description of transfer processes in the chamber, a recently developed two-dimensional model of coupled heat, mass, and momentum transfer inside the chamber was used and results of both models were compared. It can be concluded that the implementation of the two-dimensional model does not explain the observed effect. Furthermore the obtained results were compared both to the predictions of the classical theory and to the results of other investigators using different experimental devices. Plotting the experimental data on the so-called Hale plot shows that our data seem to be consistent both internally and also with the data of others. Using the nucleation theorem the critical cluster sizes were obtained from the slopes of the individual isotherms

  4. Homogeneous nucleation rate measurements of 1-propanol in helium: the effect of carrier gas pressure.

    PubMed

    Brus, David; Zdímal, Vladimír; Stratmann, Frank

    2006-04-28

    Kinetics of homogeneous nucleation in supersaturated vapor of 1-propanol was studied using an upward thermal diffusion cloud chamber. Helium was used as a noncondensable carrier gas and the influence of its pressure on observed nucleation rates was investigated. The isothermal nucleation rates were determined by a photographic method that is independent on any nucleation theory. In this method, the trajectories of growing droplets are recorded using a charge coupled device camera and the distribution of local nucleation rates is determined by image analysis. The nucleation rate measurements of 1-propanol were carried out at four isotherms 260, 270, 280, and 290 K. In addition, the pressure dependence was investigated on the isotherms 290 K (50, 120, and 180 kPa) and 280 K (50 and 120 kPa). The isotherm 270 K was measured at 25 kPa and the isotherm 260 K at 20 kPa. The experiments confirm the earlier observations from several thermal diffusion chamber investigations that the homogeneous nucleation rate of 1-propanol tends to increase with decreasing total pressure in the chamber. In order to reduce the possibility that the observed phenomenon is an experimental artifact, connected with the generally used one-dimensional description of transfer processes in the chamber, a recently developed two-dimensional model of coupled heat, mass, and momentum transfer inside the chamber was used and results of both models were compared. It can be concluded that the implementation of the two-dimensional model does not explain the observed effect. Furthermore the obtained results were compared both to the predictions of the classical theory and to the results of other investigators using different experimental devices. Plotting the experimental data on the so-called Hale plot shows that our data seem to be consistent both internally and also with the data of others. Using the nucleation theorem the critical cluster sizes were obtained from the slopes of the individual isotherms

  5. Intermolecular interactions in mixtures of ethyl formate with methanol, ethanol, and 1-propanol on density, viscosity, and ultrasonic data

    NASA Astrophysics Data System (ADS)

    Elangovan, S.; Mullainathan, S.

    2014-12-01

    Density (ρ), viscosity (η), and ultrasonic velocity ( U) have been measured for binary mixtures of ethyl formate with methanol, ethanol, and 1-propanol at 303 K. From the experimental data, adiabatic compressibility (β), acoustic impedance ( Z), viscous relaxation time (τ), free length ( L f), free volume ( V f), internal pressure (πi), and Gibbs free energy (Δ G) have been deduced. It is shown that strength of intermolecular interactions between ethyl formate with selected 1-alcohols were in the order of methanol < ethanol < 1-propanol.

  6. Statistical thermodynamics of 1-butanol, 2-methyl-1-propanol, and butanal

    NASA Astrophysics Data System (ADS)

    Seal, Prasenjit; Papajak, Ewa; Yu, Tao; Truhlar, Donald G.

    2012-01-01

    The purpose of the present investigation is to calculate partition functions and thermodynamic quantities, viz., entropy, enthalpy, heat capacity, and Gibbs free energies, for 1-butanol, 2-methyl-1-propanol, and butanal in the vapor phase. We employed the multi-structural (MS) anharmonicity method and electronic structure calculations including both explicitly correlated coupled cluster theory and density functional theory. The calculations are performed using all structures for each molecule and employing both the local harmonic approximation (MS-LH) and the inclusion of torsional anharmonicity (MS-T). The results obtained from the MS-T calculations are in excellent agreement with experimental data taken from the Thermodynamics Research Center data series and the CRC Handbook of Chemistry and Physics, where available. They are also compared with Benson's empirical group additivity values, where available; in most cases, the present results are more accurate than the group additivity values. In other cases, where experimental data (but not group additivity values) are available, we also obtain good agreement with experiment. This validates the accuracy of the electronic structure calculations when combined with the MS-T method for estimating the thermodynamic properties of systems with multiple torsions, and it increases our confidence in the predictions made with this method for molecules and temperatures where experimental or empirical data are not available.

  7. Statistical thermodynamics of 1-butanol, 2-methyl-1-propanol, and butanal.

    PubMed

    Seal, Prasenjit; Papajak, Ewa; Yu, Tao; Truhlar, Donald G

    2012-01-21

    The purpose of the present investigation is to calculate partition functions and thermodynamic quantities, viz., entropy, enthalpy, heat capacity, and Gibbs free energies, for 1-butanol, 2-methyl-1-propanol, and butanal in the vapor phase. We employed the multi-structural (MS) anharmonicity method and electronic structure calculations including both explicitly correlated coupled cluster theory and density functional theory. The calculations are performed using all structures for each molecule and employing both the local harmonic approximation (MS-LH) and the inclusion of torsional anharmonicity (MS-T). The results obtained from the MS-T calculations are in excellent agreement with experimental data taken from the Thermodynamics Research Center data series and the CRC Handbook of Chemistry and Physics, where available. They are also compared with Benson's empirical group additivity values, where available; in most cases, the present results are more accurate than the group additivity values. In other cases, where experimental data (but not group additivity values) are available, we also obtain good agreement with experiment. This validates the accuracy of the electronic structure calculations when combined with the MS-T method for estimating the thermodynamic properties of systems with multiple torsions, and it increases our confidence in the predictions made with this method for molecules and temperatures where experimental or empirical data are not available. PMID:22280759

  8. Statistical thermodynamics of 1-butanol, 2-methyl-1-propanol, and butanal.

    PubMed

    Seal, Prasenjit; Papajak, Ewa; Yu, Tao; Truhlar, Donald G

    2012-01-21

    The purpose of the present investigation is to calculate partition functions and thermodynamic quantities, viz., entropy, enthalpy, heat capacity, and Gibbs free energies, for 1-butanol, 2-methyl-1-propanol, and butanal in the vapor phase. We employed the multi-structural (MS) anharmonicity method and electronic structure calculations including both explicitly correlated coupled cluster theory and density functional theory. The calculations are performed using all structures for each molecule and employing both the local harmonic approximation (MS-LH) and the inclusion of torsional anharmonicity (MS-T). The results obtained from the MS-T calculations are in excellent agreement with experimental data taken from the Thermodynamics Research Center data series and the CRC Handbook of Chemistry and Physics, where available. They are also compared with Benson's empirical group additivity values, where available; in most cases, the present results are more accurate than the group additivity values. In other cases, where experimental data (but not group additivity values) are available, we also obtain good agreement with experiment. This validates the accuracy of the electronic structure calculations when combined with the MS-T method for estimating the thermodynamic properties of systems with multiple torsions, and it increases our confidence in the predictions made with this method for molecules and temperatures where experimental or empirical data are not available.

  9. The temperature dependent structure of liquid 1-propanol as studied by neutron diffraction and EPSR simulations

    NASA Astrophysics Data System (ADS)

    Sillrén, Per; Swenson, Jan; Mattsson, Johan; Bowron, Daniel; Matic, Aleksandar

    2013-06-01

    The structure of liquid 1-propanol is investigated as a function of temperature using neutron diffraction together with Empirical Potential Structure Refinement modelling. The combined diffraction and computer modelling analysis demonstrates that propanol molecules form hydrogen bonded clusters with a relatively wide size distribution, which broadens at lower temperatures. We find that the cluster size distribution is well described by a recently proposed statistical model for branched H-bonded networks [P. Sillrén, J. Bielecki, J. Mattsson, L. Börjesson, and A. Matic, J. Chem. Phys. 136, 094514 (2012)], 10.1063/1.3690137. The average cluster size increases from ˜3 to 7 molecules, whilst the standard deviation of the size distribution increases from 3.3 to 8.5 as the temperature is decreased from 293 to 155 K. The clusters are slightly branched, with a higher degree of branching towards lower temperatures. An analysis of the cluster gyration tensor (Rmn) reveals an average elongated ellipsoidal shape with axes having proportions 1:1.4:1.9. We find that the average radius of gyration has a cluster size dependence consistent with that of fractal clusters, Rg ∝ n1/D, with a fractal dimension D ≈ 2.20, which is close to D = 2.00 expected for an ideal random walk or D = 2.11 expected for reaction limited aggregation. The characteristic angles between the H-bonded OH-groups that constitute the clusters show only a weak temperature dependence with O-H⋯O angles becoming more narrowly distributed around 180° at lower temperatures.

  10. Biochemical, genetic, and metabolic engineering strategies to enhance coproduction of 1-propanol and ethanol in engineered Escherichia coli.

    PubMed

    Srirangan, Kajan; Liu, Xuejia; Westbrook, Adam; Akawi, Lamees; Pyne, Michael E; Moo-Young, Murray; Chou, C Perry

    2014-11-01

    We recently reported the heterologous production of 1-propanol in Escherichia coli via extended dissimilation of succinate under anaerobic conditions through expression of the endogenous sleeping beauty mutase (Sbm) operon. In the present work, we demonstrate high-level coproduction of 1-propanol and ethanol by developing novel engineered E. coli strains with effective cultivation strategies. Various biochemical, genetic, metabolic, and physiological factors affecting relative levels of acidogenesis and solventogenesis during anaerobic fermentation were investigated. In particular, CPC-PrOH3, a plasmid-free propanogenic E. coli strain derived by activating the Sbm operon on the genome, showed high levels of solventogenesis accounting for up to 85 % of dissimilated carbon. Anaerobic fed-batch cultivation of CPC-PrOH3 with glycerol as the major carbon source produced high titers of nearly 7 g/L 1-propanol and 31 g/L ethanol, implying its potential industrial applicability. The activated Sbm pathway served as an ancillary channel for consuming reducing equivalents upon anaerobic dissimilation of glycerol, resulting in an enhanced glycerol dissimilation and a major metabolic shift from acidogenesis to solventogenesis. PMID:25301579

  11. Biochemical, genetic, and metabolic engineering strategies to enhance coproduction of 1-propanol and ethanol in engineered Escherichia coli.

    PubMed

    Srirangan, Kajan; Liu, Xuejia; Westbrook, Adam; Akawi, Lamees; Pyne, Michael E; Moo-Young, Murray; Chou, C Perry

    2014-11-01

    We recently reported the heterologous production of 1-propanol in Escherichia coli via extended dissimilation of succinate under anaerobic conditions through expression of the endogenous sleeping beauty mutase (Sbm) operon. In the present work, we demonstrate high-level coproduction of 1-propanol and ethanol by developing novel engineered E. coli strains with effective cultivation strategies. Various biochemical, genetic, metabolic, and physiological factors affecting relative levels of acidogenesis and solventogenesis during anaerobic fermentation were investigated. In particular, CPC-PrOH3, a plasmid-free propanogenic E. coli strain derived by activating the Sbm operon on the genome, showed high levels of solventogenesis accounting for up to 85 % of dissimilated carbon. Anaerobic fed-batch cultivation of CPC-PrOH3 with glycerol as the major carbon source produced high titers of nearly 7 g/L 1-propanol and 31 g/L ethanol, implying its potential industrial applicability. The activated Sbm pathway served as an ancillary channel for consuming reducing equivalents upon anaerobic dissimilation of glycerol, resulting in an enhanced glycerol dissimilation and a major metabolic shift from acidogenesis to solventogenesis.

  12. Oxidation, reduction, and isomerization of allyl alcohol and 1-propanol over Cu[sub 2]O(100)

    SciTech Connect

    Schulz, K.H.; Cox, D.F. )

    1993-01-21

    The reactivity of allyl alcohol and 1-propanol has been studied with TDS and XPS on the polar, Cu[sup +]-terminated, Cu[sub 2]O(100) surface. Allyl alcohol reacts on the (100) surface to give selective and nonselective oxidation products (acrolein, CO, CO[sub 2], H[sub 2]O), an isomerization product (propionaldehyde), and a reduction product (propene). 1-Propanol also reacts on the (100) surface to give selective and nonselective oxidation products (acrolein, propionaldehyde, CO, CO[sub 2], H[sub 2]O) and a reduction product (propene). Both alcohols dissociatively adsorb to form alkoxides. The alkoxide species undergo hydride elimination on the carbon [alpha] to the oxygen to form the corresponding aldehydes. The acrolein and propionaldehyde formed from the alcohols are linked by a common surface enolate intermediate which explains the similarity in C[sub 3] products observed from the two alcohols. A low-temperature reaction to propene is attributed to pathways involving C-O bond scission from unsaturated surface oxygenates to give a surface allyl. Hydrogenation of the resulting allyl produces propene at low temperature. 28 refs., 6 figs., 2 tabs.

  13. Molecular probe dynamics and free volume in organic glass-formers and their relationships to structural relaxation: 1-propanol

    NASA Astrophysics Data System (ADS)

    Bartoš, J.; Švajdlenková, H.; Šauša, O.; Lukešová, M.; Ehlers, D.; Michl, M.; Lunkenheimer, P.; Loidl, A.

    2016-01-01

    A joint study of the rotational dynamics and free volume in amorphous 1-propanol (1-PrOH) as a prototypical monohydroxy alcohol by electron spin resonance (ESR) or positron annihilation lifetime spectroscopy (PALS), respectively, is reported. The dynamic parameters of the molecular spin probe 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and the annihilation ones of the atomic ortho-positronium (o-Ps) probe as a function of temperature are compared. A number of coincidences between various effects in the ESR and PALS responses at the corresponding characteristic ESR and PALS temperatures were found suggesting a common origin of the underlying dynamic processes that were identified using viscosity (VISC) in terms of the two-order parameter (TOP) model and broadband dielectric spectroscopy (BDS) data.

  14. Prebiotic polymerization: Oxidative polymerization of 2, 3-dimercapto-1-propanol on the surface of iron(III) hydroxide oxide

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.

    1995-01-01

    The oxidation of 2, 3-dimercapto-1-propanol by ferric ions on the surface of iron(III) hydroxide oxide (Fe(OH)O) yielded polydisulfide oligomers. This polymerization occurred readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron(III) hydroxide oxide (20 mg, 160 micromole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the Fe(OH)O phase. Reactions carried out at the same ratio of dithiol to Fe(OH)O but at higher dithiol concentrations gave higher yields of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis is discussed.

  15. Prebiotic Polymerization: Oxidative Polymerization of 2,3 Dimercapto-1- Propanol on the Surface of Iron(III) Hydroxide Oxide

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.

    1995-01-01

    The oxidation of 2,3-dimercapto-1-propanol by ferric ions on the surface of iron(III) hydroxide oxide (Fe(OH)O) yielded polydisulfide oligomers. This polymerization occurred readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron(III) hydroxide oxide (20 mg, 160 micromole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the FE(OH)O phase. Reactions carried out at the same ratio of dithiol to FE(OH)O but at higher dithiol concentrations gave higher yields of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis is discussed.

  16. Novel Dehalogenase Mechanism for 2,3-Dichloro-1-Propanol Utilization in Pseudomonas putida Strain MC4

    PubMed Central

    Arif, Muhammad Irfan; Samin, Ghufrana; van Leeuwen, Jan G. E.; Oppentocht, Jantien

    2012-01-01

    A Pseudomonas putida strain (MC4) that can utilize 2,3-dichloro-1-propanol (DCP) and several aliphatic haloacids and haloalcohols as sole carbon and energy source for growth was isolated from contaminated soil. Degradation of DCP was found to start with oxidation and concomitant dehalogenation catalyzed by a 72-kDa monomeric protein (DppA) that was isolated from cell lysate. The dppA gene was cloned from a cosmid library and appeared to encode a protein equipped with a signal peptide and that possessed high similarity to quinohemoprotein alcohol dehydrogenases (ADHs), particularly ADH IIB and ADH IIG from Pseudomonas putida HK. This novel dehalogenating dehydrogenase has a broad substrate range, encompassing a number of nonhalogenated alcohols and haloalcohols. With DCP, DppA exhibited a kcat of 17 s−1. 1H nuclear magnetic resonance experiments indicated that DCP oxidation by DppA in the presence of 2,6-dichlorophenolindophenol (DCPIP) and potassium ferricyanide [K3Fe(CN)6] yielded 2-chloroacrolein, which was oxidized to 2-chloroacrylic acid. PMID:22752160

  17. Transient thermal behavior of the hydration of 2,3-epoxy-1-propanol in a continuously stirred tank reactor

    SciTech Connect

    Ball, R.; Gray, B.F.

    1995-11-01

    The equations that model a first-order reaction occurring in the four-dimensional parameter space of a CSTR are analyzed using the methods of singularity theory. By reference to experimental data for the hydration of 2,3-epoxy-1-propanol, a direct connection is established between the parameters of the equations and the physical quantities they represent. This simple step suggests a new use for singularity theory as a design tool for chemical reactors, which is illustrated in the latter part of this work by following the pathways of degenerate bifurcations through the codimension 1 and 2 parameter spaces. In the first part of this work, a physical constraint, namely, the boiling point of the reaction mixture, is used to construct a thermal runaway curve in the codimension zero operating parameter plane. The shape of this curve reveals the remarkable, but unpleasant, fact that a decrease in the ambient temperature can lead to a thermal runaway. Such unexpected and dangerous thermal misbehavior could not be predicted from the classical codimension zero Hopf and saddle-node bifurcation loci.

  18. NBO, conformational, NLO, HOMO-LUMO, NMR and electronic spectral study on 1-phenyl-1-propanol by quantum computational methods.

    PubMed

    Xavier, S; Periandy, S; Ramalingam, S

    2015-02-25

    In this study, FT-IR, FT-Raman, NMR and UV spectra of 1-phenyl-1-propanol, an intermediate of anti-depressant drug fluoxetine, has been investigated. The theoretical vibrational frequencies and optimized geometric parameters have been calculated by using HF and density functional theory with the hybrid methods B3LYP, B3PW91 and 6-311+G(d,p)/6-311++G(d,p) basis sets. The theoretical vibrational frequencies have been found in good agreement with the corresponding experimental data. (1)H and (13)C NMR spectra were recorded and chemical shifts of the molecule were compared to TMS by using the Gauge-Independent Atomic Orbital (GIAO) method. A study on the electronic and optical properties, absorption wavelengths, excitation energy, dipole moment and frontier molecular orbital energies are performed using HF and DFT methods. The thermodynamic properties (heat capacity, entropy and enthalpy) at different temperatures are also calculated. NBO analysis is carried out to picture the charge transfer between the localized bonds and lone pairs. The local reactivity of the molecule has been studied using the Fukui function. NLO properties related to polarizability and hyperpolarizability are also discussed.

  19. Solubilities of mixtures of carbon dioxide and hydrogen sulfide in water + diethanolamine + 2-amino-2-methyl-1-propanol

    SciTech Connect

    Jane, I.S.; Li, M.H.

    1997-01-01

    The removal of acidic gases such as CO{sub 2}, H{sub 2}S, and COS from gas streams is an important operation in the natural gas and synthetic ammonia industries, oil refineries, and petrochemical chemical plants. The solubilities of mixtures of carbon dioxide and hydrogen sulfide in water + diethanolamine (DEA) + 2-amino-2-methyl-1-propanol (AMP) have been measured at 40 C and 80 C and at partial pressures of acid gases ranging from 1.0 to 200 kPa. The ternary mixtures studied were 30 mass % AMP, 6 mass % DEA + 24 mass % AMP, 12 mass % DEA + 18 mass % AMP, 18 mass % DEA + 12 mass % AMP, 24 mass % DEA + 6 mass % AMP, and 30 mass % DEA aqueous solutions. The model of Deshmukh and Mather (1981) has been used to represent the solubility of mixtures of CO{sub 2} and H{sub 2}S in the ternary solutions. The model reasonably reproduces the equilibrium partial pressures of CO{sub 2} and H{sub 2}S above the ternary solutions for the systems tested.

  20. The enthalpies and entropies of pefloxacin dissolution in methanol, ethanol, 1-Propanol, 2-Propanol, acetone, and chloroform at 293.15-323.15 K

    NASA Astrophysics Data System (ADS)

    Zhang, C.-L.; Cui, S.-J.; Wang, Y.

    2012-12-01

    The solubilities of pefloxacin in methanol, ethanol, 1-propanol, 2-propanol, acetone, and chloroform have been determined from 293.15 to 323.15 K by a static equilibrium method. The experimental data were correlated with the modified Apelblat equation. The positive Δsol H and Δsol S for each system revealed that pefloxacin dissolution in each solvent is an entropy-driven process.

  1. Comparative disposition of 2,3-epoxy-1-propanol (glycidol) in rats following oral and intravenous administration.

    PubMed

    Nomeir, A A; Silveira, D M; Ferrala, N F; Markham, P M; McComish, M F; Ghanayem, B I; Chadwick, M

    1995-02-01

    Glycidol (2,3-epoxy-1-propanol), an industrial chemical, has been shown to be a reproductive toxicant in short-term studies and a carcinogen in rats and mice in oncogenicity studies. The reproductive toxicity of glycidol was believed to result from its conversion to alpha-chlorohydrin by the action of HCl in the stomach. The comparative disposition of glycidol was investigated in rats following oral (po) or intravenous (iv) administration at doses of 37.5 and 75 mg/kg. These were the doses used in the National Toxicology Program (NTP) oncogenicity study with glycidol. Approximately 87-92% of the dose was absorbed from the gastrointestinal tract of the rat. [14C]Glycidol equivalents were eliminated in urine (40-48% of dose in 72 h), feces (5-12%), and exhaled as CO2 (26-32%). At both doses, 9-12% and 7-8% (estimated) of the dose remained in tissues at 24 and 72 h following dosing, respectively. In general, the concentrations of glycidol equivalents in tissues were proportional to the dose. The highest concentrations of radioactivity were observed in blood cells, thyroid, liver, kidney, and spleen, and the lowest in adipose tissue, skeletal muscle, and plasma. The pattern of distribution of radioactivity in tissues was similar for both the iv and po routes. The total recovery of radioactivity ranged from 87 to 91% of dose. Urinary radioactivity was resolved by high-performance liquid chromatography (HPLC) analysis into 15 metabolites. There were one major (14-21% of the dose) and four lesser metabolites (each representing 2-8%); the others were minor, each representing 1% or less of the dose. In general, the urinary metabolic profile was similar following either iv or po administration at the two doses studied. Previous studies by other investigators suggested that alpha-chlorohydrin, which was presumably formed from glycidol by the HCl in the stomach, was metabolized and excreted in urine as beta-chlorolactic acid. The results of the present study show that very

  2. Vapor-liquid equilibrium measurements at 101. 32 kPa for binary mixtures of methyl acetate + ethanol or 1-propanol

    SciTech Connect

    Ortega, J.: Susial, P.; de Alfonso, C. )

    1990-07-01

    This paper reports on isobaric vapor-liquid equilibrium data at 101.32 {plus minus} 0.02 kPa for methyl acetate (1) + ethane (2) or + 1-propanol (2). The results are compared with those predicted by the UNIFAC and ASOG methods. The methyl acetate (1) + ethanol (2) system forms an azeotrope at 329.8 K and a molar concentration of x{sub 1} = 0.958. Both methods predict the vapor-phase compositions equally well, with overall mean errors of less than 5%.

  3. Solubility of lovastatin in a family of six alcohols: Ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-octanol.

    PubMed

    Nti-Gyabaah, J; Chmielowski, R; Chan, V; Chiew, Y C

    2008-07-01

    Accurate experimental determination of solubility of active pharmaceutical ingredients (APIs) in solvents and its correlation, for solubility prediction, is essential for rapid design and optimization of isolation, purification, and formulation processes in the pharmaceutical industry. An efficient material-conserving analytical method, with in-line reversed HPLC separation protocol, has been developed to measure equilibrium solubility of lovastatin in ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-octanol between 279 and 313K. Fusion enthalpy DeltaH(fus), melting point temperature, Tm, and the differential molar heat capacity, DeltaC(P), were determined by differential scanning calorimetry (DSC) to be 43,136J/mol, 445.5K, and 255J/(molK), respectively. In order to use the regular solution equation, simplified assumptions have been made concerning DeltaC(P), specifically, DeltaC(P)=0, or DeltaC(P)=DeltaS. In this study, we examined the extent to which these assumptions influence the magnitude of the ideal solubility of lovastatin, and determined that both assumptions underestimate the ideal solubility of lovastatin. The solubility data was used with the calculated ideal solubility to obtain activity coefficients, which were then fitted to the van't Hoff-like regular solution equation. Examination of the plots indicated that both assumptions give erroneous excess enthalpy of solution, H(infinity), and hence thermodynamically inconsistent activity coefficients. The order of increasing ideality, or solubility of lovastatin was butanol>1-propanol>1-pentanol>1-hexanol>1-octanol.

  4. Liquid chromatography method for quantifying D-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (D-threo-PPMP) in mouse plasma and liver.

    PubMed

    Wu, Xiaqin; Kim, Youngleem; Sun, Bee-Chun; Moore, Jeff D; Shaw, Walter A; Maurer, Barry J

    2006-06-01

    A high-performance liquid chromatography (HPLC) method was developed to measure levels of d-threo-1-phenyl-2-palmitoylamino-3-morpholino-1-propanol (d-threo-PPMP) in mouse plasma and liver. d-threo-PPMP was measured by HPLC with a Luna Pheny-Hexyl column (5 microm, 250 mm x 4.6 mm) employing UV detection at 210 nm using a mobile phase of potassium phosphate buffer (20mM, pH 3.0)-acetonitrile in a 45:55 (v/v) ratio. d-threo-1-phenyl-2-pentadecanoylamino-3-morpholino-1-propanol (PC15MP) was employed as an internal standard (IS). The lower limit of quantitation (LLOQ) was 0.3 microg/ml. The assay was linear over a concentration range of 0.3-10 microg/ml, with acceptable precision and accuracy. Assayed in plasma, the intra- and inter-day validation for all coefficients of variation (R.S.D.%) were found less than 15%. The method was applied to samples from athymic (nu/nu) mice treated with d-threo-PPMP by intraperitoneal injection. d-threo-PPMP levels of approximately 10-20 microg/ml ( approximately 20-40 microM) in plasma and approximately 45 microg/g in liver were obtained. The present method can be used to quantify d-threo-PPMP in mice for bioavailability and dose-response studies.

  5. Studies of corrosion and corrosion control in a CO{sub 2}-2-amino-2-methyl-1-propanol (AMP) environment

    SciTech Connect

    Veawab, A.; Tontiwachwuthikul, P.; Bhole, S.D.

    1997-01-01

    The carbon dioxide (CO{sub 2}) absorption process is essential for many industrial processing operations, i.e., natural gas purification. Corrosion and corrosion inhibition in a sterically hindered amine, 2-amino-2-methyl-1-propanol (AMP), were investigated by static weight loss tests. The corrosion data were compared with those of monoethanolamine (MEA), a conventional alkanolamine, which was simultaneously tested under the same conditions. The results indicated that the AMP system was generally less corrosive to carbon steel than the MEA system, but corrosion control is still necessary. Sodium metavanadate (NaVO{sub 3}) and sodium sulfite (Na{sub 2}SO{sub 3}) were proven to be effective corrosion inhibitors, with more than 90% protection efficiency.

  6. Thermal chemistry of 2-halo-1-propanols on Ni(1 1 1) and Cu(1 1 1) surfaces: A UBI-QEP energetic modeling

    NASA Astrophysics Data System (ADS)

    Mirzanejad, Amir

    2015-12-01

    The effect of β-halogen substitutions on the thermal chemistry of 1-propanol over Ni(1 1 1) and Cu(1 1 1) single-crystal surfaces was investigated using the method of unity bond index-quadratic exponential potential (UBI-QEP). This method was employed to investigate the energetics of the catalytic conversion routes of the ad-molecule mainly at the zero-coverage limit by calculating activation barriers and enthalpy changes for surface reactions. The alcohol molecule can be oxidized partially and totally over the Ni surface, however, the molecule is rather inactive on Cu. The β-halogen substitution makes extensive conversion of the alcohol possible on the Cu surface and changes conversion pathways on the Ni surface. It was found that halogen substitution as well as hydrogen bonding can affect the reactivity and conversion routes of the molecules on Ni and Cu surfaces. On account of energetic criteria, the predicted routes for decompositions and the TPD patterns for the surface species are in accord with the available experimental observations.

  7. Multistructural variational transition state theory: kinetics of the hydrogen abstraction from carbon-2 of 2-methyl-1-propanol by hydroperoxyl radical including all structures and torsional anharmonicity.

    PubMed

    Xu, Xuefei; Yu, Tao; Papajak, Ewa; Truhlar, Donald G

    2012-11-01

    We calculated the forward and reverse rate constants of the hydrogen abstraction reaction from carbon-2 of 2-methyl-1-propanol by hydroperoxyl radical over the temperature range 250-2400 K by using multistructural canonical variational transition state theory (MS-CVT) including both multiple-structure and torsional potential anharmonicity effects by the multistructural torsional anharmonicity (MS-T) method. In these calculations, multidimensional tunneling (MT) probabilities used to compute the tunneling transmission coefficients were evaluated by the small-curvature tunneling (SCT) approximation. Comparison with the rate constants obtained by the single-structural harmonic oscillator (SS-HO) approximation shows that multistructural anharmonicity increases the forward rate constants for all temperatures, but the reverse rate constants are reduced for temperatures lower than 430 K and increased for higher temperatures. The neglect of multistructural torsional anharmonicity would lead to errors of factors of 1.5, 8.8, and 13 at 300, 1000, and 2400 K, respectively, for the forward reaction, and would lead to errors of factors of 0.76, 3.0, and 6.0, respectively, at these temperatures for the reverse reaction. PMID:23020791

  8. Supercritical CO2 desorption of activated carbon loaded with 2,2,3,3-tetrafluoro-1-propanol in a rotating packed bed.

    PubMed

    Tan, Chung-Sung; Lee, Pei-Lun

    2008-03-15

    Desorption of activated carbon loaded with 2,2,3,3-tetrafluoro-1-propanol (TFP) by supercritical carbon dioxide in a rotating packed bed was investigated in this study. The experimental data show that the time required to achieve complete desorption of TFP from activated carbon in a rotating packed bed was much lower than that in a static packed bed. The reduction of desorption time is attributed to the presence of centrifugal force. The supercritical CO2 desorption efficiency in a rotating packed bed was observed to increase with increasing rotation speed, pressure, and C02 flow rate. To enhance desorption efficiency, a smaller activated carbon particle size was suggested. At low operating pressures such as 8.96 and 11.72 MPa, a better desorption efficiency was found to occur at lower temperatures in a temperature range of 305-335 K. However, at high operating pressures such as 15.86 MPa, a temperature of 315 K was found to be more appropriate for desorption, as compared to other temperatures. Due to a reduction of packed bed volume and an increase in desorption efficiency, supercritical CO2 desorption in a rotating packed bed is suggested for recovering TFP from the exhaust gases. PMID:18409651

  9. L- and D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) inhibit neurite outgrowth from SH-SY5Y cells.

    PubMed

    Hynds, D L; Takehana, A; Inokuchi, J; Snow, D M

    2002-01-01

    Gangliosides and extracellular matrix molecules influence neurite outgrowth, but the combinatorial effects of these endogenous agents on outgrowth are unclear. Exogenous gangliosides inhibit neurite outgrowth from SH-SY5Y cells stimulated with platelet-derived growth factor-BB, and different isoforms of the ceramide analog threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) stimulate (L-PDMP) or inhibit (D-PDMP) glycosphingolipid biosynthesis. In this study, we determined whether altering the endogenous ganglioside levels with PDMP in SH-SY5Y cells regulates neurite outgrowth on the outgrowth-supporting extracellular matrix molecule, laminin. In cells stimulated with 20 ng/ml platelet-derived growth factor-BB to promote outgrowth, we used image analysis to evaluate neurite outgrowth from SH-SY5Y cells grown on endogenous matrix or laminin and exposed to L- or D-PDMP. Both L- and D-PDMP decreased neurite initiation (the number of neurites/cell, the percent of neurite-bearing cells), elongation (the length of the longest neurite/cell, the total neurite length/cell), and branching (the number of branch points/neurite) from SH-SY5Y cells on endogenous matrix or laminin in a dose-dependent manner in serum-free or serum-containing medium. The inhibitory effects of each PDMP isoform were reversible. Inhibition of neurite outgrowth by L-PDMP could be mimicked by addition of exogenous gangliosides or C2-ceramide. Our analyses of neurite outgrowth in SH-SY5Y cells, a model of developing or regenerating noradrenergic neurons, demonstrate that increasing or decreasing endogenous ganglioside levels decreases neurite outgrowth. These results may indicate that SH-SY5Y cells undergo tight regulation by gangliosides, possibly through modulation of growth/trophic factor- and/or extracellular matrix-activated signaling cascades.

  10. Mineralization and defluoridation of 2,2,3,3-tetrafluoro -1-propanol (TFP) by UV oxidation in a novel three-phase fluidized bed reactor (3P-FBR).

    PubMed

    Shih, Yu-Jen; Tsai, Meng-Tso; Huang, Yao-Hui

    2013-05-01

    2,2,3,3-Tetrafluoro-1-propanol (TFP, C3H4F4O, M.W. = 132.06) is extensively used as the solvent in CD-R and DVD-R fabrication. Since it has a fluorinated alky-chain configuration and is non-biodegradable, its treatment by conventional oxidation methods is typically very inefficient. In this work, novel three-phase fluidized bed reactor (3P-FBR, 7.5 cm in diameter, 50 cm high) that combines photo oxidation (UV/H2O2, one of AOPs (Advanced Oxidation Process) and adsorption (BT5 iron oxide as adsorbent) processes is designed for mineralizing and defluorinizing TFP wastewater. The experimental results reveal that TFP can be efficiently mineralized, and the BT5 that is circulated by aeration in the 3P-FBR system can remove the released fluoride ions in the reaction period. Irradiation with 254 nm UV and a 10 mM H2O2 dose yield a TOC removal of TFP (1.39 mM, equivalent to an initial TOC of 50 ppm) of over 99.95% in 2 h, and 99% of fluoride was removed by BT5 with an adsorption capacity of 24.1 mg-F g(-1). PMID:23453590

  11. Mineralization and defluoridation of 2,2,3,3-tetrafluoro -1-propanol (TFP) by UV oxidation in a novel three-phase fluidized bed reactor (3P-FBR).

    PubMed

    Shih, Yu-Jen; Tsai, Meng-Tso; Huang, Yao-Hui

    2013-05-01

    2,2,3,3-Tetrafluoro-1-propanol (TFP, C3H4F4O, M.W. = 132.06) is extensively used as the solvent in CD-R and DVD-R fabrication. Since it has a fluorinated alky-chain configuration and is non-biodegradable, its treatment by conventional oxidation methods is typically very inefficient. In this work, novel three-phase fluidized bed reactor (3P-FBR, 7.5 cm in diameter, 50 cm high) that combines photo oxidation (UV/H2O2, one of AOPs (Advanced Oxidation Process) and adsorption (BT5 iron oxide as adsorbent) processes is designed for mineralizing and defluorinizing TFP wastewater. The experimental results reveal that TFP can be efficiently mineralized, and the BT5 that is circulated by aeration in the 3P-FBR system can remove the released fluoride ions in the reaction period. Irradiation with 254 nm UV and a 10 mM H2O2 dose yield a TOC removal of TFP (1.39 mM, equivalent to an initial TOC of 50 ppm) of over 99.95% in 2 h, and 99% of fluoride was removed by BT5 with an adsorption capacity of 24.1 mg-F g(-1).

  12. Enzymes involved in the glycidaldehyde (2,3-epoxy-propanal) oxidation step in the kinetic resolution of racemic glycidol (2,3-epoxy-1-propanol) by Acetobacter pasteurianus.

    PubMed

    Wandel, U; Machado, S S.; Jongejan, J A.; Duine, J A.

    2001-02-01

    It is already known that kinetic resolution of racemic glycidol (2,3-epoxy-1-propanol) takes place when Acetobacter pasteurianus oxidizes the compound to glycidic acid (2,3-epoxy-propionic acid) with glycidaldehyde (2,3-epoxy-propanal) proposed to be the transient seen in this conversion. Since inhibition affects the feasibility of a process based on this conversion in a negative sense, and the chemical reactivity of glycidaldehyde predicts that it could be the cause for the phenomena observed, it is important to know which enzyme(s) oxidise(s) this compound. To study this, rac.- as well as (R)-glycidaldehyde were prepared by chemical synthesis and analytical methods developed for their determination. It appears that purified quinohemoprotein alcohol dehydrogenase (QH-ADH type II), the enzyme responsible for the kinetic resolution of rac.-glycidol, also catalyses the oxidation of glycidaldehyde. In addition, a preparation exhibiting dye-linked aldehyde dehydrogenase activity for acetaldehyde, most probably originating from molybdohemoprotein aldehyde dehydrogenase (ALDH), which has been described for other Acetic acid bacteria, oxidised glycidaldehyde as well with a preference for the (R)-enantiomer, the selectivity quantified by an enantiomeric ratio (E) value of 7. From a comparison of the apparent kinetic parameter values of QH-ADH and ALDH, it is concluded that ALDH is mainly responsible for the removal of glycidaldehyde in conversions of glycidol catalysed by A. pasteurianus cells. It is shown that the transient observed in rac.-glycidol conversion by whole cells, is indeed (R)-glycidaldehyde. Since both QH-ADH and ALDH are responsible for vinegar production from ethanol by Acetobacters, growth and induction conditions optimal for this process seem also suited to yield cells with high catalytic performance with respect to kinetic resolution of glycidol and prevention of formation of inhibitory concentrations glycidaldehyde.

  13. Laser-Based Measurement of Refractive Index Changes: Kinetics of 2,3-Epoxy-1-propanol Hydrolysis.

    ERIC Educational Resources Information Center

    Spencer, Bert; Zare, Richard N.

    1988-01-01

    Describes an experiment in which a simple laser-based apparatus is used for measuring the change in refractive index during the acid-catalyzed hydrolysis of glycidol into glycerine. Gives a schematic of the experimental setup and discusses the kinetic analysis. (MVL)

  14. Factors relevant to the production of (R)-(+)-glycidol (2,3-epoxy-1-propanol) from racemic glycidol by enantioselective oxidation with Acetobacter pasteurianus ATCC 12874.

    PubMed

    Geerlof, A; Jongejan, J A; van Dooren, T J; Racemakers-Franken, P C; van den Tweel, W J; Duine, J A

    1994-12-01

    Acetobacter pasteurianus oxidizes glycidol with high activity, comparable to the oxidation of ethanol. The organism has a preference for the S-enantiomer, and the kinetic resolution process obeys a simple relationship, indicating an enantiomeric ratio (E) of 19. The compound is converted into glycidic acid, although a transient accumulation of glycidaldehyde occurs initially. Determination of other parameters revealed a temperature optimum of 50 degrees C, long-term stability (cells in the resting state), and a pH optimum compatible with the chemical stability of glycidol. However, it was also noted that respiration rates decrease at concentrations of glycidol above 1 M. This is most likely caused by substrate inhibition of the glycidol-oxidizing enzyme, the quinohemoprotein ethanol dehydrogenase. Comparison with existing methods for enantiomerically pure glycidol production indicated a number of attractive points for the method described here, although definitive evaluation must await further studies on the long-term stability under process conditions, reusability of the cells, and the mechanism of glycidol inhibition.

  15. Thermodynamic and acoustical properties of mixtures p-anisaldehyde—alkanols (C1-C4)—2-methyl-1-propanol at 303.15 K

    NASA Astrophysics Data System (ADS)

    Saini, Balwinder; Kumar, Ashwani; Rani, Ruby; Bamezai, Rajinder K.

    2016-07-01

    The density, viscosity and speed of sound of pure p-anisaldehyde and some alkanols, for example, methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, and the binary mixtures of p-anisaldehyde with these alkanols were measured over the entire composition range at 303.15 K. From the experimental data, various thermodynamic parameters such as excess molar volume ( V E), excess Gibbs free energy of activation (Δ G*E), and deviation parameters like viscosity (Δη), speed of sound (Δ u), isentropic compressibility (Δκs), are calculated. The excess as well as deviation parameters are fitted to Redlich—Kister equation. Additionally, the viscosity data for the systems has been used to correlate the application of empirical relation given by Grunberg and Nissan, Katti and Chaudhari, and Hind et al. The results are discussed in terms of specific interactions present in the mixtures.

  16. In vitro comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin(R), and the Hawaiian marine algae, Chaetoceros, activity against anaerobically grown Staphylococcus aureus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mastitis is a common illness of dairy cattle and is very costly, economically, to the dairy farmer. Thus, there is a need to develop broad-spectrum therapies that are effective while not leading to unacceptably long antibiotic withdrawal times. The effects of the CH4-inhibitors nitroethane (2 mg/m...

  17. In vitro comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin(R), and the Hawaiian marine algae, Chaetoceros, activity against anaerobically grown Staphylococcus aureus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen and may also contain foodborne or opportunistic human pathogens as well as causative agents of mastitis in cows. Thus, there is a need to develop broad-spectrum therapies that are effective while...

  18. Comparison of nitroethane, 2-nitro-1-propanol, lauric acid, Lauricidin and the Hawaiian marine algae, Chaetoceros, for potential broad-spectrum control of anaerobically grown lactic acid bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The gastrointestinal tract of bovines often contains bacteria that contribute to disorders of the rumen and may also contain foodborne or opportunistic human pathogens as well as bacteria capable of causing mastitis in cows. Thus, there is a need to develop broad-spectrum therapies that are effecti...

  19. Characterisation of tequila according to their major volatile composition using multilayer perceptron neural networks.

    PubMed

    Ceballos-Magaña, Silvia G; de Pablos, Fernando; Jurado, José Marcos; Martín, María Jesús; Alcázar, Ángela; Muñiz-Valencia, Roberto; Gonzalo-Lumbreras, Raquel; Izquierdo-Hornillos, Roberto

    2013-02-15

    Differentiation of silver, gold, aged and extra-aged tequila using 1-propanol, ethyl acetate, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-methyl-1-butanol and furan derivatives like 5-(hydroxymethyl)-2-furaldehyde and 2-furaldehyde has been carried out. The content of 1-propanol, ethyl acetate, 2-methyl-1-propanol, 3-methyl-1-butanol and 2-methyl-1-butanol was determined by means of head space solid phase microextraction gas chromatography mass-spectrometry. 5-(Hydroxymethyl)-2-furaldehyde and 2-furaldehyde were determined by high performance liquid chromatography with diode array detection. Kruskal-Wallis test was used to highlight significant differences between types of tequila. Principal component analysis was applied as visualisation technique. Linear discriminant analysis and multilayer perceptron artificial neural networks were used to construct classification models. The best classification performance was obtained when multilayer perceptron model was applied.

  20. Separation of eight selected flavan-3-ols on cellulose thin-layer chromatographic plates.

    PubMed

    Vovk, Irena; Simonovska, Breda; Vuorela, Heikki

    2005-06-10

    The potential of microcristaline cellulose as sorbent in the separation of eight compounds: (+)-catechin (C), (-)-epicatechin (EC), (-)-gallocatechin (GC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECg), (-)-epigallocatechin gallate (EGCg), procyanidin B1 and procyanidin B2 was studied. Cellulose HPTLC plates prewashed in water (not necessary, when water was used as developing solvent) and dried with a hair dryer, bandwise application and development in horizontal developing chamber (sandwich configuration) gave the best results. Detection was performed using vanillin-H3PO4 reagent. Four new developing solvent systems were proposed: water, 1-propanol-water (20:80, v/v), 1-propanol-water-acetic acid (4:2:1, v/v) and 1-propanol-water-acetic acid (20:80:1, v/v), and at least two of them were needed for the differentiation between all eight compounds. Surprisingly, water enabled the separation of epimers C from EC and GC from EGC, as well as the dimers procianidin B1 and B2. Additionally, C, EGC, B1 and B2 were separated from all the other compounds. The best choice for developing solvent is given for each of the studied compounds. The best separation of the five main catechins (EC, GC, EGC, ECg, EGCg) present in green tea extract was achieved using 1-propanol-water-acetic acid (20:80:1, v/v). The chromatograms of oak bark extract developed in solvents with higher water content (1-propanol-water (1:4, v/v) and 1-propanol-water-acetic acid (20:80:1, v/v)) showed less bands than chromatograms developed in solvents with higher organic modifier content (e.g. 1-propanol-water-acetic acid (4:2:1, v/v)). It was proved that such behavior was due to the presence of procyanidins beside the main component catechin.

  1. Effect of temperature on the dynamics of benzophenone anion solvation in alcohol

    SciTech Connect

    Zhang, X.; Jonah, C.D.

    1996-04-25

    The solvation of the benzophenone anion in 1-propanol, 2-propanol, and 1-butanol has been measured over the temperature range -10 to -50{degree}C. The initial spectra of the benzophenone anion were very similar in all three alcohols. The final spectrum of the benzophenone anion in 2-propanol is less blue-shifted (17nm) than the spectrum of the anion in 1-propanol and 1-butanol. The activation energies for solvation are 22 kJ/mol for 1-propanol and 1-butanol and 16 kJ/mol for 2-propanol, which are similar to the energy for hydrogen bond breakage in the pure solvents. This suggests that the solvent H-bond breakage plays an important role in anion solvation. 37 refs., 12 figs., 1 tab.

  2. Regioselective alkane hydroxylation with a mutant AlkB enzyme

    DOEpatents

    Koch, Daniel J.; Arnold, Frances H.

    2012-11-13

    AlkB from Pseudomonas putida was engineered using in-vivo directed evolution to hydroxylate small chain alkanes. Mutant AlkB-BMO1 hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. Mutant AlkB-BMO2 similarly hydroxylates propane and butane at the terminal carbon at a rate greater than the wild-type to form 1-propanol and 1-butanol, respectively. These biocatalysts are highly active for small chain alkane substrates and their regioselectivity is retained in whole-cell biotransformations.

  3. Alcohol Dehydration on Monooxo W=O and Dioxo O=W=O Species

    SciTech Connect

    Li, Zhenjun; Smid, Bretislav; Kim, Yu Kwon; Matolin, Vladimir; Kay, Bruce D.; Rousseau, Roger J.; Dohnalek, Zdenek

    2012-08-16

    The dehydration of 1-propanol on nanoporous WO3 films prepared via ballistic deposition at ~20 K has been investigated using temperature programmed desorption, infrared reflection absorption spectroscopy and density functional theory. The as deposited films are extremely efficient in 1-propanol dehydration to propene. This activity is correlated with the presence of dioxo O=W=O groups while monooxo W=O species are shown to be inactive. Annealing of the film induces densification that results in the loss of catalytic activity due to annihilation O=W=O species.

  4. Aversive Olfactory Learning and Associative Long-Term Memory in "Caenorhabditis elegans"

    ERIC Educational Resources Information Center

    Amano, Hisayuki; Maruyama, Ichiro N.

    2011-01-01

    The nematode "Caenorhabditis elegans" ("C. elegans") adult hermaphrodite has 302 invariant neurons and is suited for cellular and molecular studies on complex behaviors including learning and memory. Here, we have developed protocols for classical conditioning of worms with 1-propanol, as a conditioned stimulus (CS), and hydrochloride (HCl) (pH…

  5. Mass balance evaluation of alcohol emission from cattle feed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Silage on dairy farms has been recognized as an important source of volatile organic compounds (VOCs) to the atmosphere, and therefore a contributor to tropospheric ozone. Considering reactivity and likely emission rates, ethanol, 1-propanol, and acetaldehyde probably make the largest contribution t...

  6. BAL increases the arsenic-74 content of rabbit brain

    SciTech Connect

    Hoover, T.D.; Aposhian, H.V.

    1983-08-01

    The /sup 74/As content of the brain of rabbits was doubled following administration of BAL (2,3-dimercapto-1-propanol). DMPS (2,3-dimercapto-1-propanesulfonic acid, sodium salt), however, decreased the rabbit brain arsenic concentration. The use of BAL as the drug of choice for treatment of arsenic intoxication should be viewed with caution and re-examined.

  7. 40 CFR Appendix I to Part 192 - Listed Constituents

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Hydrocyanic acid Hydrofluoric acid Hydrogen sulfide (H2 S) Indeno(1,2,3-cd)pyrene Isobutyl alcohol (1-Propanol...-) Methylene chloride (Methane, dichloro-) Methyl ethyl ketone (MEK) (2-Butanone) Methyl ethyl ketone peroxide (2-Butanone, peroxide) Methyl hydrazine (Hydrazine, methyl-) Methyl iodide (Methane, iodo-)...

  8. 40 CFR Appendix I to Part 192 - Listed Constituents

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Hydrocyanic acid Hydrofluoric acid Hydrogen sulfide (H2 S) Indeno(1,2,3-cd)pyrene Isobutyl alcohol (1-Propanol...-) Methylene chloride (Methane, dichloro-) Methyl ethyl ketone (MEK) (2-Butanone) Methyl ethyl ketone peroxide (2-Butanone, peroxide) Methyl hydrazine (Hydrazine, methyl-) Methyl iodide (Methane, iodo-)...

  9. 40 CFR Appendix I to Part 192 - Listed Constituents

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Hydrocyanic acid Hydrofluoric acid Hydrogen sulfide (H2 S) Indeno(1,2,3-cd)pyrene Isobutyl alcohol (1-Propanol...-) Methylene chloride (Methane, dichloro-) Methyl ethyl ketone (MEK) (2-Butanone) Methyl ethyl ketone peroxide (2-Butanone, peroxide) Methyl hydrazine (Hydrazine, methyl-) Methyl iodide (Methane, iodo-)...

  10. Catalyst Activity Comparison of Alcohols over Zeolites

    SciTech Connect

    Ramasamy, Karthikeyan K.; Wang, Yong

    2013-01-01

    Alcohol transformation to transportation fuel range hydrocarbon on HZSM-5 (SiO2 / Al2O3 = 30) catalyst was studied at 360oC and 300psig. Product distributions and catalyst life were compared using methanol, ethanol, 1-propanol or 1-butanol as a feed. The catalyst life for 1-propanol and 1-butanol was more than double compared to that for methanol and ethanol. For all the alcohols studied, the product distributions (classified to paraffin, olefin, napthene, aromatic and naphthalene compounds) varied with time on stream (TOS). At 24 hours TOS, liquid product from 1-propanol and 1-butanol transformation primarily contains higher olefin compounds. The alcohol transformation process to higher hydrocarbon involves a complex set of reaction pathways such as dehydration, oligomerization, dehydrocyclization, and hydrogenation. Compared to ethylene generated from methanol and ethanol, oligomerization of propylene and butylene has a lower activation energy and can readily take place on weaker acidic sites. On the other hand, dehydrocyclization of propylene and butylene to form the cyclic compounds requires the sits with stronger acid strength. Combination of the above mentioned reasons are the primary reasons for olefin rich product generated in the later stage of the time on stream and for the extended catalyst life time for 1 propanol and 1 butanol compared to methanol and ethanol conversion over HZSM-5.

  11. Synthesis and characterization of DI-[3-(trimethylsilyl)-1-propylene] alkylenediphosphonic acids.

    SciTech Connect

    Griffith-Dzielawa, J. A.; Barrans, R. E., Jr.; McAlister, D. R.; Dietz, M. L.; Herlinger, A. W.; Chemistry; Loyola Univ. of Chicago

    2000-01-01

    A homologous series of alkylenediphosphonic acids was successfully esterified with 3-(trimethylsilyl)-1-propanol to the symmetrically-substituted diesters. The procedure, which has general applicability for incorporating silicon heteroatoms into diphosphonic acids, utilizes the esterification reagent dicyclohexyl-carbodiimide (DCC) to activate the acid. The aggregation properties of the di-[3-(trimethylsilyl)-1-propylene] alkylenediphosphonic acids were measured in toluene and 1-decanol.

  12. Ruminal fermentation of anti-methanogenic nitrate- and nitro-containing forages in vitro

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nitrate, 3-nitro-1-propionic acid (NPA), and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if fed at high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied li...

  13. AGONISTIC SENSORY EFFECTS OF AIRBORNE CHEMICALS IN MIXTURES: ODOR, NASAL PUNGENCY, AND EYE IRRITATION

    EPA Science Inventory

    Threshold responses of odor, nasal pungency (irritation), and eye irritation were measured for single chemicals (1-propanol, 1-hexanol, ethyl acetate, heptyl acetate, 2-pentanone, 2-heptanone, toluene, ethyl benzene, and propyl benzene) and mixtures of them (two three-component m...

  14. Characterization of bovine ruminal and equine cecal microbial populations enriched for enhanced nitro-toxin metabolizing activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The phytochemicals 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) are produced by a wide variety of leguminous plants, including over 150 different species and varieties of Astragalus. These compounds are toxic to naive grazing animals, but can be safely fed to cattle and sheep that h...

  15. Synthesis of both enantiomers of 12-methyl-13-tridecanolide and 14-methyl-15-pentadecanolide (muscolide).

    PubMed

    Noda, Yoshihiro; Mamiya, Natsuki; Kashin, Hitoshi

    2013-07-01

    Both enantiomers of 12-methyl-13-tridecanolide{(R)-(+)-1, (S)-(-)-1} and 14-methyl-15-pentadecanolide (muscolide) {(R)-(+)-2, (S)-(-)-2} were synthesized from either (S)-(+)- or (R)-(-)-3-bromo-2-methyl-1-propanol 8 as a chiral building block. PMID:23980425

  16. Control over the color transition behavior of polydiacetylene vesicles using different alcohols.

    PubMed

    Pattanatornchai, Thanutpon; Charoenthai, Nipaphat; Wacharasindhu, Sumrit; Sukwattanasinitt, Mongkol; Traiphol, Rakchart

    2013-02-01

    In this contribution, we investigate the color transition behavior of polydiacetylene (PDA) vesicles upon exposure to different chemical stimuli. A series of linear and branched alcohols are used as model additives, allowing systematic control of their molecular shape and polarity. The PDA vesicles are fabricated by using three monomers, 10,12-pentacosadiynoic acid (PCDA), 10,12-tricosadyinoic acid (TCDA), and N-(2-amino ethyl)pentacosa-10,12-dyinamide (AEPCDA). When a series of linear alcohols is used, the longer alcohol length causes color transition of all PDA vesicles. In this system, the penetration of linear alcohols into the inner layer of PDA vesicles is dictated by their polarity. The change of -OH position within the alcohol molecule also affects the degree of penetration. It requires a higher amount of the 2-propanol to induce color transitions of the PDAs compared to that of the 1-propanol. The addition of methyl branches into the hydrophobic tail of alcohols causes an increase in steric effect, which hinders the penetration as well. When the 2,2-dimethyl-1-propanol is used as a stimulus, the color transition of PDAs occurs at much higher alcohol concentration compared to 2-methyl-1-butanol, 3-methyl-1-butanol, and 1-pentanol. The variation of PDA structures also affects their ability to interact with the alcohols. The modified head group of poly(AEPCDA) promotes the ability to distinguish between 1-propanol and 2-propanol or 1-propanol and ethanol.

  17. Using Nuclear Magnetic Resonance Spectroscopy for Measuring Ternary Phase Diagrams

    ERIC Educational Resources Information Center

    Woodworth, Jennifer K.; Terrance, Jacob C.; Hoffmann, Markus M.

    2006-01-01

    A laboratory experiment is presented for the upper-level undergraduate physical chemistry curriculum in which the ternary phase diagram of water, 1-propanol and n-heptane is measured using proton nuclear magnetic resonance (NMR) spectroscopy. The experiment builds upon basic concepts of NMR spectral analysis, typically taught in the undergraduate…

  18. Biocatalytic synthesis of C3 chiral building blocks by chloroperoxidase-catalyzed enantioselective halo-hydroxylation and epoxidation in the presence of ionic liquids.

    PubMed

    Liu, Yan; Wang, Yali; Jiang, Yucheng; Hu, Mancheng; Li, Shuni; Zhai, Quanguo

    2015-01-01

    The optically active C3 synthetic blocks are remarkably versatile intermediates for the synthesis of numerous pharmaceuticals and agrochemicals. This work provides a simple and efficient enzymatic synthetic route for the environment-friendly synthesis of C3 chiral building blocks. Chloroperoxidase (CPO)-catalyzed enantioselective halo-hydroxylation and epoxidation of chloropropene and allyl alcohol was employed to prepare C3 chiral building blocks in this work, including (R)-2,3-dichloro-1-propanol (DCP*), (R)-2,3-epoxy-1-propanol (GLD*), and (R)-3-chloro-1-2-propanediol (CPD*). The ee values of the formed C3 chiral building blocks DCP*, CPD*, and glycidol were 98.1, 97.5, and 96.7%, respectively. Moreover, the use of small amount of imidazolium ionic liquid enhanced the yield efficiently due to the increase of solubility of hydrophobic organic substrates in aqueous reaction media, as well as the improvement of affinity and selectivity of CPO to substrate.

  19. Selective deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) surfaces

    NASA Astrophysics Data System (ADS)

    Xiong, Ke; Yu, Weiting; Chen, Jingguang G.

    2014-12-01

    The selective deoxygenation of aldehydes and alcohols without cleaving the Csbnd C bond is crucial for upgrading bio-oil and other biomass-derived molecules to useful fuels and chemicals. In this work, propanal, 1-propanol, furfural and furfuryl alcohol were selected as probe molecules to study the deoxygenation of aldehydes and alcohols on molybdenum carbide (Mo2C) prepared over a Mo(1 1 0) surface. The reaction pathways were investigated using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS). The deoxygenation of propanal and 1-propanol went through a similar intermediate (propoxide or η2(C,O)-propanal) to produce propene. The deoxygenation of furfural and furfuryl alcohol produced a surface intermediate similar to adsorbed 2-methylfuran. The comparison of these results revealed the promising deoxygenation performance of Mo2C, as well as the effect of the furan ring on the selective deoxygenation of the Cdbnd O and Csbnd OH bonds.

  20. Synthesis of 1,3,3-trinitroazetidine

    DOEpatents

    Hiskey, Michael A.; Coburn, Michael D.

    1994-01-01

    A process of preparing 1,3,3-trinitroazetidine including forming a 5-hydroxymethyl-5-nitro-1-alkyltetrahydro-1,3-oxazine, e.g., reacting a 1,3,5-trialkyl hexahydrotriazine and tris(hydroxymethyl)nitromethane, ring opening said 5-hydroxymethyl-5-nitro-1-alkyltetrahydro-1,3-oxazine to form a 3-alkylamino-2-hydroxymethyl-2-nitro-1-propanol salt, ring closing said 3-alkylamino-2-hydroxymethyl-2-nitro-1-propanol salt to form a 3-hydroxymethyl-3-nitro-1-alkylazetidine salt, nitrating said 3-hydroxymethyl-3-nitro-1-alkylazetidine salt to form a 1-alkyl-3,3-dinitroazetidine, and converting said 1-alkyl-3,3-dinitroazetidine into 1,3,3-trinitroazetidine is disclosed.

  1. Gas Scavenging of Soluble and Insoluble Organic Vapors by Levitated Water Drops.

    NASA Astrophysics Data System (ADS)

    Seaver, Mark; Barrett, Amy

    1994-07-01

    Three-millimeter-diameter drops of water were levitated with a standing acoustic wave centered in the jet of a small wind tunnel and the volume changes as the drop evaporates in the presence of 1-propanol vapor were measured. The results are compared with a steady-state continuum evaporation model based on nonideal solution theory. Because the thermodynamic parameter for the 1-propanol-water system are well known, this system provides a test for our model. Good overall agreement between model and experiment results means that small discrepancies can be used to establish limits for dynamic effects. An immiscible liquids version of this model, which accounts for gas scavenging of methyl salicylate, is used to predict the amount of insoluble material scavenged by a drop of water evaporating to dryness. This model predicts that the volume of organic liquid left behind increases as the relative humidity approaches 100%.

  2. Supercritical Carbon Dioxide-Soluble Ligands for Extracting Actinide Metal Ions from Porous Solids

    SciTech Connect

    Dietz, Mark L.; Barrans Jr., Richard E.; Herlinger, Albert; Brennecke, Joan F.

    1999-06-01

    The focus of the effort during the project period from 9/16/98 to 6/15/99 has been on the synthesis, aggregation, and coordination chemistry of silyl-containing diphosphonic acids that potentially could be useful as solvent extraction reagents in supercritical CO2. A homologous series of alkylenediphosphonic acids was esterified with 3-(trimethylsilyl)-1- propanol to the symmetrically-substituted diesters. The silicon-containing alcohol 3- (trimethylsilyl)-1-propanol was chosen for esterification of the diphosphonic acids because it contains both a silyl group and a trimethylene linker. Separating the trimethylsilyl from the organo-functional group by three carbon atoms is optimal for achieving chemical stability and synthetic accessibility. The synthesis of these compounds utilizes methodology that relies on dicyclohexylcarbodiimide as the esterification reagent to activate the acid.

  3. Synthesis of 1,3,3-trinitroazetidine

    DOEpatents

    Hiskey, M.A.; Coburn, M.D.

    1994-08-09

    A process of preparing 1,3,3-trinitroazetidine includes forming a 5-hydroxymethyl-5-nitro-1-alkyltetrahydro-1,3-oxazine, e.g., reacting a 1,3,5-trialkyl hexahydrotriazine and tris(hydroxymethyl)nitromethane, ring opening said 5-hydroxymethyl-5-nitro-1-alkyltetrahydro-1,3-oxazine to form a 3-alkylamino-2-hydroxymethyl-2-nitro-1-propanol salt, ring closing said 3-alkylamino-2-hydroxymethyl-2-nitro-1-propanol salt to form a 3-hydroxymethyl-3-nitro-1-alkylazetidine salt, nitrating said 3-hydroxymethyl-3-nitro-1-alkylazetidine salt to form a 1-alkyl-3,3-dinitroazetidine, and converting said 1-alkyl-3,3-dinitroazetidine into 1,3,3-trinitroazetidine is disclosed. 1 fig.

  4. 40 CFR Table 2a to Subpart E of... - Reactivity Factors

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Ethylene Glycol 107-21-1 3.36 2-Methyl-2,4-Pentanediol 107-41-5 1.04 Isohexane Isomers 107-83-5 1.80 Methyl...-0 0.51 C8 Disubstituted Benzenes (xylenes, mixed isomers) 1330-20-7 7.48 Ethylene Glycol 2... (Dipentene or Orange Terpene) 5989-27-5 3.99 Dipropylene Glycol Methyl Ether Isomer (2- -1-Propanol)...

  5. 40 CFR Table 2a to Subpart E of... - Reactivity Factors

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ethylene Glycol 107-21-1 3.36 2-Methyl-2,4-Pentanediol 107-41-5 1.04 Isohexane Isomers 107-83-5 1.80 Methyl...-0 0.51 C8 Disubstituted Benzenes (xylenes, mixed isomers) 1330-20-7 7.48 Ethylene Glycol 2... (Dipentene or Orange Terpene) 5989-27-5 3.99 Dipropylene Glycol Methyl Ether Isomer (2- -1-Propanol)...

  6. The bellamy relationship and the nature of the H-bond. 2-Haloethanols

    NASA Astrophysics Data System (ADS)

    Vokin, A. I.; Turchaninov, V. K.

    2015-01-01

    IR-spectroscopy data show that the intramolecular H-bond in alcohols with the general formula XCH2CH2OH (X = F, Cl, Br) in a solution is mainly of a nonspecific nature. Molecules of 2-haloethanol form three-center complexes with an external H-bond acceptor. The intramolecular component of their bifurcated bond causes a stronger spectroscopic effect as compared to the two-center H-bond of ethanol or 1-propanol.

  7. The Extraction of Caffeine from Tea: An Old Undergraduate Experiment Revisited

    NASA Astrophysics Data System (ADS)

    Murray, Scott D.; Hansen, Peter J.

    1995-09-01

    The extraction of caffeine from tea leaves is a common organic chemistry experiment. A water/1-propanol/sodium chloride ternary system was found to be a suitable replacement for the more traditional water/organochlorine solvent systems. Approximately 80% of the caffeine in the tea leaves can be recovered as crude caffeine. The ternary system employs chemicals which are not only less expensive, but also less toxic.

  8. Continuous-wave dye lasers in the DCM region.

    PubMed

    Hammond, P; Cooke, D

    1992-11-20

    Laser dye DCM in an ethylene glycol solution is a favored medium for converting the argon-ion 488- and 514-nm pump lines to tunable radiation in the 600-730-nm region. However, the dye precipitates from solution, is a powerful mutagen, and the glycol solvent is hygroscopic. Replacement dyes in 3-phenyl-1- propanol or 2-phenoxyethanol, particularly the latter, are proposed.

  9. Continuous-wave dye lasers in the DCM region

    SciTech Connect

    Hammond, P.; Cooke, D. )

    1992-11-20

    Laser dye DCM in an ethylene glycol solution is a favored medium for converting the argon-ion 488- and 514-nm pump lines to tunable radiation in the 600--730-nm region. However, the dye precipitates from solution, is a powerful mutagen, and the glycol solvent is hygroscopic. Replacement dyes in 3-phenyl-1-propanol or 2-phenoxyethanol, particularly the latter, are proposed.

  10. Escherichia coli mar and acrAB mutants display no tolerance to simple alcohols.

    PubMed

    Ankarloo, Jonas; Wikman, Susanne; Nicholls, Ian A

    2010-01-01

    The inducible Mar phenotype of Escherichia coli is associated with increased tolerance to multiple hydrophobic antibiotics as well as some highly hydrophobic organic solvents such as cyclohexane, mediated mainly through the AcrAB/TolC efflux system. The influence of water miscible alcohols ethanol and 1-propanol on a Mar constitutive mutant and a mar deletion mutant of E. coli K-12, as well as the corresponding strains carrying the additional acrAB deletion, was investigated. In contrast to hydrophobic solvents, all strains were killed in exponential phase by 1-propanol and ethanol at rates comparable to the parent strain. Thus, the Mar phenotype does not protect E. coli from killing by these more polar solvents. Surprisingly, AcrAB does not contribute to an increased alcohol tolerance. In addition, sodium salicylate, at concentrations known to induce the mar operon, was unable to increase 1-propanol or ethanol tolerance. Rather, the toxicity of both solvents was increased in the presence of sodium salicylate. Collectively, the results imply that the resilience of E. coli to water miscible alcohols, in contrast to more hydrophobic solvents, does not depend upon the AcrAB/TolC efflux system, and suggests a lower limit for substrate molecular size and functionality. Implications for the application of microbiological systems in environments containing high contents of water miscible organic solvents, e.g., phage display screening, are discussed. PMID:20480026

  11. Indirectly suspended droplet microextraction of water-miscible organic solvents by salting-out effect for the determination of polycyclic aromatic hydrocarbons.

    PubMed

    Daneshfar, Ali; Khezeli, Tahere

    2014-12-01

    A simple and low-cost method that indirectly suspended droplet microextraction of water-miscible organic solvents (ISDME) by salting-out effect before high-performance liquid chromatography and ultraviolet (HPLC-UV) detection was used for the determination of polycyclic aromatic hydrocarbons (PAHs) in different samples. The ISDME is a combination of salting-out extraction of water-miscible organic solvent and directly suspended droplet microextraction (DSDME). Ninety-five microliters water-miscible organic solvent (1-propanol) was added to a 500-µL sample. A homogeneous solution was formed immediately. To produce a steady vortex at the top of the solution, the sample was agitated at 700 rpm using a magnetic stirrer. By the addition of ammonium sulfate (saturated solution) to the homogeneous solution, 1-propanol was separated and collected at the bottom of the steady vortex. Finally, 20 µL 1-propanol was injected into HPLC-UV. The effects of important parameters such as water-miscible organic solvent (type and volume), type of salt, and extraction time were evaluated. Under optimum conditions, the method has a good linear calibration range (0.1 µg/L-300 µg/L), coefficients of determination (R(2) > 0.998), low limits of detection (between 0.02 µg/L and 0.27 µg/L), and acceptable recovery (>85.0%).

  12. Fiber content of diet affects exhaled breath volatiles in fasting and postprandial state in a pilot crossover study.

    PubMed

    Raninen, Kaisa J; Lappi, Jenni E; Mukkala, Maria L; Tuomainen, Tomi-Pekka; Mykkänen, Hannu M; Poutanen, Kaisa S; Raatikainen, Olavi J

    2016-06-01

    Our pilot study examined the potential of exhaled breath analysis in studying the metabolic effects of dietary fiber (DF). We hypothesized that a high-fiber diet (HFD) containing whole grain rye changes volatile organic compound (VOC) levels in exhaled breath and that consuming a single meal affects these levels. Seven healthy men followed a week-long low-fiber diet (17 g/d) and HFD (44 g/d) in a randomized crossover design. A test meal containing 50 g of the available carbohydrates from wheat bread was served as breakfast after each week. Alveolar exhaled breath samples were analyzed at fasting state and 30, 60, and 120 minutes after this meal parallel to plasma glucose, insulin, and serum lipids. We used solid-phase microextraction and gas chromatography-mass spectrometry for detecting changes in 15 VOCs. These VOCs were acetone, ethanol, 1-propanol, 2-propanol, 1-butanol, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, 2-methylbutyric acid, hexanoic acid, acetoin, diacetyl, and phenol. Exhaled breath 2-methylbutyric acid in the fasting state and 1-propanol at 120 minutes decreased (P = .091 for both) after an HFD. Ingestion of the test meal increased ethanol, 1-propanol, acetoin, propionic acid, and butyric acid levels while reducing acetone, 1-butanol, diacetyl, and phenol levels. Both DF diet content and having a single meal affected breathVOCs. Exploring exhaled breath further could help to develop tools for monitoring the metabolic effects of DF. PMID:27188907

  13. "Wet" Versus "Dry" Folding of Polyproline

    NASA Astrophysics Data System (ADS)

    Shi, Liuqing; Holliday, Alison E.; Bohrer, Brian C.; Kim, Doyong; Servage, Kelly A.; Russell, David H.; Clemmer, David E.

    2016-06-01

    When the all- cis polyproline-I helix (PPI, favored in 1-propanol) of polyproline-13 is introduced into water, it folds into the all- trans polyproline-II (PPII) helix through at least six intermediates [Shi, L., Holliday, A.E., Shi, H., Zhu, F., Ewing, M.A., Russell, D.H., Clemmer, D.E.: Characterizing intermediates along the transition from PPI to PPII using ion mobility-mass spectrometry. J. Am. Chem. Soc. 136, 12702-12711 (2014)]. Here, we show that the solvent-free intermediates refold into the all- cis PPI helix with high (>90%) efficiency. Moreover, in the absence of solvent, each intermediate appears to utilize the same small set of pathways observed for the solution-phase PPII → PPI transition upon immersion of PPIIaq in 1-propanol. That folding in solution (under conditions where water is displaced by propanol) and folding in vacuo (where energy required for folding is provided by collisional activation) occur along the same pathway is remarkable. Implicit in this statement is that 1-propanol mimics a "dry" environment, similar to the gas phase. We note that intermediates with structures that are similar to PPIIaq can form PPII under the most gentle activation conditions—indicating that some transitions observed in water (i.e. , "we t" folding, are accessible (albeit inefficient) in vacuo. Lastly, these "dry" folding experiments show that PPI (all cis) is favored under "dry" conditions, which underscores the role of water as the major factor promoting preference for trans proline.

  14. Nanoparticle-Mediated, Light-Induced Phase Separations.

    PubMed

    Neumann, Oara; Neumann, Albert D; Silva, Edgar; Ayala-Orozco, Ciceron; Tian, Shu; Nordlander, Peter; Halas, Naomi J

    2015-12-01

    Nanoparticles that both absorb and scatter light, when dispersed in a liquid, absorb optical energy and heat a reduced fluid volume due to the combination of multiple scattering and optical absorption. This can induce a localized liquid-vapor phase change within the reduced volume without the requirement of heating the entire fluid. For binary liquid mixtures, this process results in vaporization of the more volatile component of the mixture. When subsequently condensed, these two steps of vaporization and condensation constitute a distillation process mediated by nanoparticles and driven by optical illumination. Because it does not require the heating of a large volume of fluid, this process requires substantially less energy than traditional distillation using thermal sources. We investigated nanoparticle-mediated, light-induced distillation of ethanol-H2O and 1-propanol-H2O mixtures, using Au-SiO2 nanoshells as the absorber-scatterer nanoparticle and nanoparticle-resonant laser irradiation to drive the process. For ethanol-H2O mixtures, the mole fraction of ethanol obtained in the light-induced process is substantially higher than that obtained by conventional thermal distillation, essentially removing the ethanol-H2O azeotrope that limits conventional distillation. In contrast, for 1-propanol-H2O mixtures the distillate properties resulting from light-induced distillation were very similar to those obtained by thermal distillation. In the 1-propanol-H2O system, a nanoparticle-mediated, light-induced liquid-liquid phase separation was also observed. PMID:26535465

  15. The use of coenzyme Q0 as a template in the development of a molecularly imprinted polymer for the selective recognition of coenzyme Q10.

    PubMed

    Contin, Mario; Flor, Sabrina; Martinefski, Manuela; Lucangioli, Silvia; Tripodi, Valeria

    2014-01-01

    In this work, a novel molecularly imprinted polymer (MIP) for use as a solid phase extraction sorbent was developed for the determination of coenzyme Q10 (CoQ10) in liver extract. CoQ10 is an essential cofactor in mitochondrial oxidative phosphorylation and a powerful antioxidant agent found in low concentrations in biological samples. This fact and its high hydrophobicity make the analysis of CoQ10 technically challenging. Accordingly, a MIP was synthesised using coenzyme Q0 as the template, methacrylic acid as the functional monomer, acetonitrile as the porogen, ethylene glycol dimethacrylate as the crosslinker and benzoyl peroxide as the initiator. Various parameters affecting the polymer preparation and extraction efficiency were evaluated. Morphological characterisation of the MIP and its proper comparison with C18 as a sorbent in solid phase extraction were performed. The optimal conditions for the molecularly imprinted solid phase extraction (MISPE) consisted of 400 μL of sample mixed with 30 mg of MIP and 600 μL of water to reach the optimum solution loading. The loading was followed by a washing step consisting of 1 mL of a 1-propanol solution (1-propanol:water, 30:70,v/v) and elution with 1 mL of 1-propanol. After clean-up, the CoQ10 in the samples was analysed by high performance liquid chromatography. The extraction recoveries were higher than 73.7% with good precision (3.6-8.3%). The limits of detection and quantification were 2.4 and 7.5 μg g(-1), respectively, and a linear range between 7.5 and 150 μg g(-1) of tissue was achieved. The new MISPE procedure provided a successful clean-up for the determination of CoQ10 in a complex matrix.

  16. Production of propyl gallate in nonaqueous medium using cell-associated tannase of Bacillus massiliensis: effect of various parameters and statistical optimization.

    PubMed

    Aithal, Mahesh; Belur, Prasanna D

    2013-01-01

    Enzymatic synthesis of propyl gallate in an organic solvent was studied using cell-associated tannase (E.C. 3.1.1.20) of Bacillus massiliensis. Lyophilized biomass showing tannase activity was used as a biocatalyst. The influence of buffer pH and strength, water activity, temperature, biocatalyst loading, gallic acid concentration, and 1-propanol concentration was studied by the one-factor-at-a-time method. Subsequently, response surface methodology was applied based on a central composite design to determine the effects of three independent variables (biocatalyst loading, gallic acid concentration, and 1-propanol concentration) and their mutual interactions. A total of 20 experiments were conducted, and a statistical model was developed, which predicted the maximum propyl gallate yield of 20.28 μg/mL in the reaction mixture comprising 40.4 mg biocatalyst, 0.4 mM gallic acid, and 6.52 % (v/v) 1-propanol in 9.5 mL benzene at 30°C. The subsequent verification experiments established the validity of the model. Under optimal conditions, 25% conversion of gallic acid to propyl gallate was achieved on a molar basis. The absence of the need for enzyme purification and subsequent immobilization steps and good conversion efficiency makes this enzyme system an interesting one. Reports on the applications of bacterial whole cell systems for synthetic reactions in organic solvents are scarce, and perhaps this is the first report on bacterial cell-associated tannase-mediated esterification in a nonaqueous medium. PMID:23600575

  17. Comparison of solvents for removing pesticides from skin using an in vitro porcine model.

    PubMed

    Campbell, J L; Smith, M A; Eiteman, M A; Williams, P L; Boeniger, M F

    2000-01-01

    This study compared four solvents (1-propanol, polyethylene glycol [avg. MW 400], 10% Ivory Liquid and water, and D-TAM) for their ability to remove selected pesticides from an in vitro porcine skin model using a solvent-moistened wipe. Wipes were performed 90 min after pesticide was applied to the skin. The four pesticides selected (glyphosate, alachlor, methyl parathion, and trifluralin) were chosen because of their differences in water solubility. This study also determined whether pretreatment of skin with a solvent prior to pesticide application would either increase or decrease recovery of the pesticide. Recovery efficiencies for all solvents and pesticides were affected by the amount of contaminant on the skin. Although pesticide recoveries from all four solvents were similar (range: 45-57%), on average 1-propanol had significantly higher recoveries, followed by soap and water. There was no significant difference between polyethylene glycol, and D-TAM. When skin was pretreated with any of the four solvents before pesticide application, the recoveries of the more water soluble compounds, glyphosate and alachlor, decreased. When pretreatment with solvent preceded application of trifluralin, the pesticide with the lowest water solubility, recoveries increased. 1-Propanol or soap and water were more effective in removing pesticides from skin than polyethylene glycol or D-TAM, but the amount of pesticide recovered from skin was affected by the chemical characteristics of the pesticide (such as water solubility) and the amount of pesticide originally on the skin. This study provides information useful to the interpretation of skin wipe sample results collected in field studies.

  18. Application of solubility parameters in 1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol organogel in binary organic mixtures.

    PubMed

    Shen, Huahua; Niu, Libo; Fan, Kaiqi; Li, Jingjing; Guan, Xidong; Song, Jian

    2014-08-01

    The gelation behavior of 1,3:2,4-bis(3,4-dimethylbenzylidene)sorbitol (DMDBS) in binary solvents has been systematically investigated. DMDBS is soluble in DMSO and insoluble in toluene (apolar) or 1-propanol (polar). When DMSO is added to a poor solvent at a certain volume fraction, DMDBS forms an organogel in the mixed solvent. With increasing DMSO content, the minimum gelation concentration increases and the gel-to-sol transition temperature decreases in both systems. However, compared with those in toluene-DMSO mixtures, the gelation ability and thermal stability are better in 1-propanol-DMSO mixtures. Scanning electron microscopy images reveal that the gelators aggregate to form three-dimensional networks. X-ray diffraction shows that the gel has a lamellar structure, which is different from the structure of the precipitate. Fourier transform infrared results reveal H-bonding is the main driving force for self-aggregation and indicate that stronger H-bonding interactions exist between gelators in 1-propanol-DMSO mixtures in contrast with toluene-DMSO mixtures. Attempts have been taken to correlate solvent parameters to gelation behavior in binary solvents. A Teas plot exhibits distinctly different solvent zones in the studied mixed solvents. The polar parameter (δp) indicates a narrow favorable domain for gel formation in the range of 1.64-7.99 MPa(1/2) for some apolar solvent-DMSO mixtures. The hydrogen-bonding parameter (δh) predicts that gelation occurs for values of 14.00-16.50 MPa(1/2) for some polar solvent-DMSO mixtures. The result may have potential applications in predicting the gelation behavior of 1,3:2,4-di-O-benzylidene-d-sorbitol derivatives in mixed solvents. PMID:25019199

  19. Liquid organization and solvation properties at polar solid/liquid interfaces.

    PubMed

    Gobrogge, Eric A; Woods, B Lauren; Walker, Robert A

    2013-01-01

    Second order nonlinear optical spectroscopy has been employed to examine the organization of four different liquids at the hydrophilic silica/liquid interface. The liquids - cyclohexane, methylcyclohexane, 1-propanol, and 2-propanol - were chosen to isolate how intermolecular forces between the liquid and the substrate competed with steric effects to control liquid structure and solvating properties across the interfacial region. Vibrational sum frequency generation (VSFG) data showed that cyclohexane structure at the silica/liquid cyclohexane interface closely resembled the structure of a cyclohexane monolayer adsorbed to the silica/vapor interface. Methylcyclohexane, however, showed evidence of large structural reorganization between the silica/liquid and silica/monolayer/vapor interfaces. 1-Propanol at a silica/vapor interface formed a well-ordered, Langmuir-like monolayer due to strong hydrogen bonding with the surface silanols and cohesive van der Waals interactions between carbon chains. 1-Propanol at the silica/liquid interface retained the same ordered structure. In contrast, 2-propanol adopted different structures adsorbed to the solid/vapor and at the solid/ liquid interfaces. Specifically, the plane defined by 2-propanol's three carbon atoms changed orientation from being perpendicular to the surface (silica/vapor) to parallel to the surface (silica/liquid). Surface mediated liquid structure affected the solvation of adsorbed solutes. Resonance enhanced second harmonic generation (SHG) data showed that silica/alkane interfaces were significantly more polar than would be expected based on a solute's bulk solution solvatochromic behavior. Both silica/alcohol interfaces exhibited alkane-like polarity, a result that was interpreted in terms of a reduction in hydrogen bonding opportunities for adsorbed solutes.

  20. Self-reduction of a copper complex MOD ink for inkjet printing conductive patterns on plastics.

    PubMed

    Farraj, Yousef; Grouchko, Michael; Magdassi, Shlomo

    2015-01-31

    Highly conductive copper patterns on low-cost flexible substrates are obtained by inkjet printing a metal complex based ink. Upon heating the ink, the soluble complex, which is composed of copper formate and 2-amino-2-methyl-1-propanol, decomposes under nitrogen at 140 °C and is converted to pure metallic copper. The decomposition process of the complex is investigated and a suggested mechanism is presented. The ink is stable in air for prolonged periods, with no sedimentation or oxidation problems, which are usually encountered in copper nanoparticle based inks. PMID:25482984

  1. Separation of cis and trans Isomers of Polyproline by FAIMS Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Creese, Andrew J.; Cooper, Helen J.

    2016-10-01

    High field asymmetric waveform ion mobility spectrometry (FAIMS) is well-established as a tool for separating peptide isomers (sequence inversions and post-translationally modified localization variants). Here, we demonstrate the FAIMS is able to differentiate cis and trans isomers of polyproline. Polyproline assumes an all-cis conformation—the PPI helix—in 1-propanol, and an all-trans conformation—the PPII helix—in aqueous solutions. Differentiation of these conformers may be achieved both through use of a cylindrical FAIMS device and a miniaturized ultrahigh field planar FAIMS device.

  2. Analysis of polysaccharides in cider: their effect on sensory foaming properties.

    PubMed

    Mangas, J J; Moreno, J; Rodríguez, R; Picinelli, A; Suárez, B

    1999-01-01

    A feasible spectrophotometric method for determining acidic and neutral polysaccharides in cider is described, and the advantages of this method are examined with respect to precision, accuracy, and detection and quantitation limits. The concentration of nonvolatile and volatile components in cider, together with chemometric techniques such as principal component analysis (PCA), soft independent modeling of class analogy (SIMCA), and partial least squares (PLS), allowed us to typify the ciders on the basis of their foaming properties. Acidic polysaccharide and 1-propanol were the most relevant variables for this purpose. PMID:10563864

  3. Isothermal compressibility of amino alcohols in the pressure range from 0.1 to 300 MPa at 298 K

    NASA Astrophysics Data System (ADS)

    Rodnikova, M. N.; Troitskii, V. M.; Solonina, I. A.; Shirokova, E. V.; Kraevskii, S. V.

    2015-01-01

    The isothermal compressibilities of three amino alcohols are measured on a unique setup for direct compression in the pressure range of 0.1 to 300 MPa at 298 K. The lowest baric dependence of isothermal compressibility is found for 3-amino-1-propanol, while 2-amino-1-butanol is characterized by the highest isothermal compressibility. The crystallization of 4-amino-1-butanol is observed at pressures of 200-250 MPa. The resulting data are discussed from the viewpoint of the stability of spatial hydrogen bond networks in amino alcohols and are compared to the similar dependences of liquid diols.

  4. Propylene from renewable resources: catalytic conversion of glycerol into propylene.

    PubMed

    Yu, Lei; Yuan, Jing; Zhang, Qi; Liu, Yong-Mei; He, He-Yong; Fan, Kang-Nian; Cao, Yong

    2014-03-01

    Propylene, one of the most demanded commodity chemicals, is obtained overwhelmingly from fossil resources. In view of the diminishing fossil resources and the ongoing climate change, the identification of new efficient and alternative routes for the large-scale production of propylene from biorenewable resources has become essential. Herein, a new selective route for the synthesis of propylene from bio-derived glycerol is demonstrated. The route consists of the formation of 1-propanol (a versatile bulk chemical) as intermediate through hydrogenolysis of glycerol at a high selectivity. A subsequent dehydration produces propylene. PMID:24578188

  5. The lipid moiety of brincidofovir is required for in vitro antiviral activity against Ebola virus.

    PubMed

    McMullan, Laura K; Flint, Mike; Dyall, Julie; Albariño, César; Olinger, Gene G; Foster, Scott; Sethna, Phiroze; Hensley, Lisa E; Nichol, Stuart T; Lanier, E Randall; Spiropoulou, Christina F

    2016-01-01

    Brincidofovir (BCV) is the 3-hexadecyloxy-1-propanol (HDP) lipid conjugate of the acyclic nucleoside phosphonate cidofovir (CDV). BCV has established broad-spectrum activity against double-stranded DNA (dsDNA) viruses; however, its activity against RNA viruses has been less thoroughly evaluated. Here, we report that BCV inhibited infection of Ebola virus in multiple human cell lines. Unlike the mechanism of action for BCV against cytomegalovirus and other dsDNA viruses, phosphorylation of CDV to the diphosphate form appeared unnecessary. Instead, antiviral activity required the lipid moiety and in vitro activity against EBOV was observed for several HDP-nucleotide conjugates.

  6. Characteristic of Nitron for Use as a Chemical Sensor in Studies of the Upper Atmosphere

    NASA Technical Reports Server (NTRS)

    Meadows, Kapres; Wright, Cassandra K.; Sims, S. C.; Morris, V. R.

    1997-01-01

    We are investigating the use of nitron as a potential chemical sensor for nitric acid and other electron deficient nitrogen oxides. Solutions of nitron in 1-propanol, toluene, and chloroform have been tested for use on a piezoelectric quartz crystal microbalance. We are testing various solvents and metal cations which can maximize the lifetime and reaction specificity of nitron so that they may be used as chemical coatings for stratospheric measurement of trace gases. Results of the work to date will be shown, and future direction discussed.

  7. Method for producing high dielectric strength microvalves

    DOEpatents

    Kirby, Brian J.; Reichmuth, David S.; Shepodd, Timothy J.

    2006-04-04

    A microvalve having a cast-in-place and lithographically shaped mobile, polymer monolith for fluid flow control in microfluidic devices and method of manufacture. The microvalve contains a porous fluorinated polymer monolithic element whose pores are filled with an electrically insulating, high dielectric strength fluid, typically a perfluorinated liquid. This combination provides a microvalve that combines high dielectric strength with extremely low electrical conductivity. These microvalves have been shown to have resistivities of at least 100 G.OMEGA. and are compatible with solvents such as water at a pH between 2.7 and 9.0, 1-1 propanol, acetonitrile, and acetone.

  8. In search of the thermo/halochromism of the ET(30) pyridinium-N-phenolate betaine dye

    NASA Astrophysics Data System (ADS)

    Rezende, Marcos Caroli; Aracena, Andrés

    2012-12-01

    The thermohalochromic behavior of Reichardt's ET(30) betaine - the temperature-dependent variation of its halochromic band in the presence of a cation - was investigated for the first time in NaI solutions of HBD- (methanol, ethanol, 1-propanol, 1-butanol) and non-HBD-solvents (acetonitrile, dimethylformamide) at 15 and 55 °C. The solvent-dependent thermohalochromism of the pyridinium-N-phenolate betaine dye was interpreted in terms of the effect of the temperature on the dye-cation association in solution.

  9. Glass transition of associated solvents studied by fluorescence measurement of doped chromophores

    NASA Astrophysics Data System (ADS)

    Ye, Jing Yong; Hattori, Toshiaki; Inouye, Hideyuki; Ueta, Hiroshi; Nakatsuka, Hiroki; Maruyama, Yoshihiro; Ishikawa, Mitsuru

    1996-04-01

    The fluorescence lifetime of a triphenylmethane dye, malachite green, doped in three glass-forming associated solvents, 1-propanol, propylene glycol, and glycerol, was measured in a wide temperature range. For each sample three temperature regimes were found in the temperature dependence of the nonradiative relaxation time of malachite green. The lower crossover temperature corresponds to the calorimetric glass transition temperature, and the higher one, 30-50 K above the lower one, is attributed to the critical temperature that is predicted by mode-coupling theory.

  10. Propylene from renewable resources: catalytic conversion of glycerol into propylene.

    PubMed

    Yu, Lei; Yuan, Jing; Zhang, Qi; Liu, Yong-Mei; He, He-Yong; Fan, Kang-Nian; Cao, Yong

    2014-03-01

    Propylene, one of the most demanded commodity chemicals, is obtained overwhelmingly from fossil resources. In view of the diminishing fossil resources and the ongoing climate change, the identification of new efficient and alternative routes for the large-scale production of propylene from biorenewable resources has become essential. Herein, a new selective route for the synthesis of propylene from bio-derived glycerol is demonstrated. The route consists of the formation of 1-propanol (a versatile bulk chemical) as intermediate through hydrogenolysis of glycerol at a high selectivity. A subsequent dehydration produces propylene.

  11. Synthesis and tautomerization of hydroxylated isoflavones bearing heterocyclic hemi-aminals.

    PubMed

    Frasinyuk, Mykhaylo S; Bondarenko, Svitlana P; Khilya, Volodymyr P; Liu, Chunming; Watt, David S; Sviripa, Vitaliy M

    2015-01-28

    The aminomethylation of hydroxylated isoflavones with 2-aminoethanol, 3-amino-1-propanol, 4-amino-1-butanol, and 5-amino-1-pentanol in the presence of excess formaldehyde led principally to 9-(2-hydroalkyl)-9,10-dihydro-4H,8H-chromeno[8,7-e][1,3]-oxazin-4-ones 4 and/or the tautomeric 7-hydroxy-8-(1,3-oxazepan-3-ylmethyl)-4H-chromen-4-ones 5. The ratio of these tautomers was dependent on solvent polarity, electronic effects of aryl substituents in the isoflavone and the structure of the amino alcohol. NMR studies confirmed the interconversion of tautomeric forms.

  12. DFT modeling of CO2 interaction with various aqueous amine structures.

    PubMed

    Davran-Candan, Tugba

    2014-06-26

    In this study, the interaction of CO2 with aqueous monoethanolamine (MEA), 2-amino-2-methyl-1-propanol (AMP), ethylenediamine (EDA), guanidine, and tetramethylguanidine (TMG) was studied by using density functional theory (DFT) modeling. MEA was chosen as the benchmark system, and the reaction pathways of carbamate as well as bicarbonate formations were analyzed thoroughly in order to evaluate the performances of the amines involved in this study in terms of thermodynamics and reaction kinetics. Among the materials considered, AMP was shown to be the most promising one due to its decreased product stability.

  13. FTIR/PCA study of propanol in argon matrix: The initial stage of clustering and conformational transitions

    NASA Astrophysics Data System (ADS)

    Doroshenko, Iryna; Balevicius, Vytautas; Pitsevich, George; Aidas, Kestutis; Sablinskas, Valdas; Pogorelov, Valeriy

    2014-12-01

    FTIR spectra of 1-propanol in an argon matrix were studied in the range 11-30 K. Principal component analysis of dynamic FTIR spectra and nonlinear band shape fitting has been carried out. The peaks of monomer, open dimer, mixed propanol-water dimer and those of higher H-bond clusters have been resolved and analyzed. The attribution of certain FTIR peaks has been supported by proper density functional theory calculations. Analyzing dependences of the integral band intensities of various aggregates on temperature it has been deduced that in the initial stage of clustering monomers and dimers are the basic building blocks forming higher H-bond clusters. The peaks assigned to two conformers of monomers and mixed propanol-water dimers were investigated processing the temperature dependences of their integral intensities in Arrhenius plot. The obtained values of 0.18 kJ.mol-1 for propanol monomer and 0.26 kJ.mol-1 for mixed dimer are well comparable with the energy differences between the global minimum conformation of 1-propanol (Gt) and some other energetically higher structures (Tt or Tg).

  14. Hydrophobic and hydrophilic interactions in aqueous mixtures of alcohols at a hydrophobic surface.

    PubMed

    Ballal, Deepti; Chapman, Walter G

    2013-09-21

    Aqueous solutions of alcohols are interesting because of their anomalous behavior that is believed to be due to the molecular structuring of water and alcohol around each other in solution. The interfacial structuring and properties are significant for application in alcohol purification processes and biomolecular structure. Here we study aqueous mixtures of short alcohols (methanol, ethanol, 1-propanol, and 2-propanol) at a hydrophobic surface using interfacial statistical associating fluid theory which is a perturbation density functional theory. The addition of a small amount of alcohol decreases the interfacial tension of water drastically. This trend in interfacial tension can be explained by the structure of water and alcohol next to the surface. The hydrophobic group of an added alcohol preferentially goes to the surface preserving the structure of water in the bulk. For a given bulk alcohol concentration, water mixed with the different alcohols has different interfacial tensions with propanol having a lower interfacial tension than methanol and ethanol. 2-propanol is not as effective in decreasing the interfacial tension as 1-propanol because it partitions poorly to the surface due to its larger excluded volume. But for a given surface alcohol mole fraction, all the alcohol mixtures give similar values for interfacial tension. For separation of alcohol from water, methods that take advantage of the high surface mole fraction of alcohol have advantages compared to separation using the vapor in equilibrium with a water-alcohol liquid.

  15. N-substituted monodentate alcohols as ligands modifying structure, properties and thermal stability of Mo(IV) complexes

    NASA Astrophysics Data System (ADS)

    Jurowska, Anna; Szklarzewicz, Janusz; Hodorowicz, Maciej; Tomecka, Monika; Lipkowski, Janusz; Nitek, Wojciech

    2015-02-01

    The reaction of N-substituted alcohols (2-aminoethanol, 3-amino-1-propanol and 2-hydroxyethylhydrazine) with K3Na[Mo(CN)4O2]ṡ6H2O in water-ethanol solution results in isolation of three new complexes of formulae: (PPh4)2[Mo(CN)4O(amet)]ṡ3H2O (1), (amet = 2-aminoethanol), (PPh4)2[Mo(CN)4O(ampro)]ṡ3H2O (2) (ampro = 3-amino-1-propanol) and (PPh4)2[Mo(CN)4O(ethyd)]ṡ3H2O (3) (ethyd = 2-hydroxyethylhydrazine). The isolated salts were characterized by elemental analysis, single crystal X-ray structure measurements, IR and UV-Vis spectroscopy and cyclic voltammetry. The complexes crystalize in triclinic space group with distorted octahedral geometry of the anion. The obtained salts belongs to a very rare group of complexes with monodentate terminal N-donating alcohols. The thermal stability is described for all complexes and compared with crystal structure parameters.

  16. Nucleation of ethanol, propanol, butanol, and pentanol: A systematic experimental study along the homologous series

    NASA Astrophysics Data System (ADS)

    Manka, Alexandra A.; Wedekind, Jan; Ghosh, David; Höhler, Kristina; Wölk, Judith; Strey, Reinhard

    2012-08-01

    We present homogeneous vapor-liquid nucleation rates of the 1-alcohols (CnH2n+1OH, n = 2-4) measured in the well-established two-valve nucleation pulse chamber as well as in a novel one-piston nucleation pulse chamber at temperatures between 235 and 265 K. The nucleation rates and critical cluster sizes show a very systematic behavior with respect to the hydrocarbon chain length of the alcohol, just as their thermo-physical parameters such as surface tension, vapor pressure, and density would suggest. For all alcohols, except ethanol, predictions of classical nucleation theory lie several orders of magnitude below the experimental results and show a strong temperature-dependence typically found in nucleation experiments. The more recent Reguera-Reiss theory [J. Phys. Chem. B 108(51), 19831 (2004)] achieves reasonably good predictions for 1-propanol, 1-butanol, and 1-pentanol, and independent of the temperature. Ethanol, however, clearly shows the influence of strong association between molecules even in the vapor phase. We also scaled all experimental results with classic nucleation theory to compare our data with other data from the literature. We find the same overall temperature trend for all measurement series together but inverted and inconsistent temperature trends for individual 1-propanol and 1-butanol measurements in other devices. Overall, our data establishe a comprehensive and reliable data set that forms an ideal basis for comparison with nucleation theory.

  17. Impact of different techniques involving contact with lees on the volatile composition of cider.

    PubMed

    Antón-Díaz, María José; Suárez Valles, Belén; Mangas-Alonso, Juan José; Fernández-García, Ovidio; Picinelli-Lobo, Anna

    2016-01-01

    The effect of different treatments involving contact with natural lees on the aromatic profile of cider has been evaluated. Comparing with the untreated ciders, the contact with lees brought about a significant increase of the concentrations of most of the volatile compounds analysed, in particular fatty acids, alcohols, ethyl esters and 3-ethoxy-1-propanol. The opposite was observed among fusel acetate esters and 4-vinylguaiacol. The addition of β-glucanase enhanced the increase of ethyl octanoate, but produced a decrease in the contents of decanoic acid and all of the major volatiles excepting acetaldehyde, ethyl acetate and acetoine, whereas the application of oxygen influenced the rise of the level of 3-ethoxy-1-propanol only. The olfactometric profiles also revealed significant effects of the treatment with lees for ethyl propionate, diacetyl, cis-3-hexenol, acetic acid, benzyl alcohol, and m-cresol, while the addition of oxygen significantly influenced the perception of ethyl hexanoate, 1-octen-3-one, 3-methyl-2-butenol, t-3-hexenol and c-3-hexenol. PMID:26213084

  18. A novel chemoenzymatic synthesis of propyl caffeate using lipase-catalyzed transesterification in ionic liquid.

    PubMed

    Pang, Na; Gu, Shuang-Shuang; Wang, Jun; Cui, Hong-Sheng; Wang, Fang-Qin; Liu, Xi; Zhao, Xing-Yu; Wu, Fu-An

    2013-07-01

    Propyl caffeate has the highest antioxidant capacity in the caffeate alkyl esters family, but industrial production of propyl caffeate is hindered by low yields using either the chemical or enzymatic catalysis method. To set up a high-yield process for obtaining propyl caffeate, a novel chemoenzymatic synthesis method using lipase-catalyzed transesterification of an intermediate methyl caffeate or ethyl caffeate and 1-propanol in ionic liquid was established. The maximum propyl caffeate yield of 98.5% was obtained using lipase-catalyzed transesterification under the following optimal conditions: Novozym 435 as a biocatalyst, [Bmim][CF3SO3] as a medium, a molar ratio of methyl caffeate to 1-propanol of 1:5, a mass ratio of methyl caffeate to lipase of 1:20, and a reaction temperature of 60°C. The two-step conversion of caffeic acid to propyl caffeate via methyl caffeate is an efficient way to prepare propyl caffeate with an overall yield of 82.7%.

  19. Solubility of simvastatin: A theoretical and experimental study

    NASA Astrophysics Data System (ADS)

    Aceves-Hernández, Juan M.; Hinojosa-Torres, Jaime; Nicolás-Vázquez, Inés; Ruvalcaba, Rene Miranda; García, Rosa María Lima

    2011-05-01

    Solubility experimental data from Simvastatin in a family of alcohols were obtained at different temperatures. Simvastatin was characterized by using thermal analysis and X-ray diffraction. From the experimental solubility data an anomalous behavior was observed, since an increase the number of alcohol carbon atoms shows an increase in solubility only for the three first alcohols, ethanol, 1-propanol and 1-butanol. A decrease in solubility was obtained for 1-pentanol, 1-hexanol and 1-octanol. Van't·Hoff equation was used to obtain the theoretical solubility value and the ideal activity coefficient. Experimental error was very low and does not affect the plots and equations used. No polymorphic phenomenon was found from the Simvastatin characterization. Theoretical calculations were carried out in order to corroborate the experimental solubility data. Trends and results are similar in both cases. The geometry optimizations of Simvastatin was carried out using density functional theory with Becke's three parameter hybrid method and correlation functional of Lee, Yang and Parr (B3LYP) with 6-311++G∗∗ basis set. The solvent effect was treated using a continuum model as modeled in water, methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol and 1-octanol. Moreover, dielectric constant, dipolar moment and solubility in the solvents were obtained for explaining the former behavior.

  20. Investigation of chemical modifiers for the direct determination of arsenic in fish oil using high-resolution continuum source graphite furnace atomic absorption spectrometry.

    PubMed

    Pereira, Éderson R; de Almeida, Tarcísio S; Borges, Daniel L G; Carasek, Eduardo; Welz, Bernhard; Feldmann, Jörg; Campo Menoyo, Javier Del

    2016-04-01

    High-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS) has been applied for the development of a method for the determination of total As in fish oil samples using direct analysis. The method does not use any sample pretreatment, besides dilution with 1-propanole, in order to decrease the oil viscosity. The stability and sensitivity of As were evaluated using ruthenium and iridium as permanent chemical modifiers and palladium added in solution over the sample. The best results were obtained with ruthenium as the permanent modifier and palladium in solution added to samples and standard solutions. Under these conditions, aqueous standard solutions could be used for calibration for the fish oil samples diluted with 1-propanole. The pyrolysis and atomization temperatures were 1400 °C and 2300 °C, respectively, and the limit of detection and characteristic mass were 30 pg and 43 pg, respectively. Accuracy and precision of the method have been evaluated using microwave-assisted acid digestion of the samples with subsequent determination by HR-CS GF AAS and ICP-MS; the results were in agreement (95% confidence level) with those of the proposed method.

  1. Efficient yet accurate approximations for ab initio calculations of alcohol cluster thermochemistry.

    PubMed

    Umer, Muhammad; Kopp, Wassja A; Leonhard, Kai

    2015-12-01

    We have calculated the binding enthalpies and entropies of gas phase alcohol clusters from ethanol to 1-decanol. In addition to the monomers, we have investigated dimers, tetramers, and pentamers. Geometries have been obtained at the B3LYP/TZVP level and single point energy calculations have been performed with the Resolution of the Identity-MP2 (RIMP2) method and basis set limit extrapolation using aug-cc-pVTZ and aug-cc-pVQZ basis sets. Thermochemistry is calculated with decoupled hindered rotor treatment for large amplitude motions. The results show three points: First, it is more accurate to transfer the rigid-rotor harmonic oscillator entropies from propanol to longer alcohols than to compute them with an ultra-fine grid and tight geometry convergence criteria. Second, the computational effort can be reduced considerably by using dimerization energies of longer alcohols at density functional theory (B3LYP) level plus a RIMP2 correction obtained from 1-propanol. This approximation yields results almost with the same accuracy as RIMP2 - both methods differ for 1-decanol only 0.4 kJ/mol. Third, the entropy of dimerization including the hindered rotation contribution is converged at 1-propanol with respect to chain length. This allows for a transfer of hindered rotation contributions from smaller alcohols to longer ones which reduces the required computational and man power considerably. PMID:26646881

  2. Multi-walled carbon nanotubes covalently bonded cellulose composite for chemical vapor sensor

    NASA Astrophysics Data System (ADS)

    Yun, Sungryul; Yang, Sang Yeol; Kim, Jaehwan

    2010-04-01

    A cellulose solution was prepared by dissolving cotton pulp in LiCl/ N,N-Dimethylacetamide (DMAc) solution, and functionalized multi-walled carbon nanotubes (MWCNTs) were reacted with N, N-Carbonyldiimidazoles to obtain MWCNTs-imidazolides. By acylation of cellulose with MWCNTs-imidazolides, MWCNTs were covalently bonded with cellulose chains. Using the product, MWCNTs covalently bonded cellulose composite (M/C) composite was fabricated with mechanical stretching to align MWCNTs with cellulose. Finally, inter-digital comb electrode was formed on the composite via lift-off process. Chemo-electrical properties of the M/C composite in response of absorption of the volatile vapors corresponding to 1-propanol, 1-butanol, methanol and ethanol were investigated. Due to sensitive and reversible expansion/contraction of the M/C composite matrix in response to absorption of each analyte, the M/C composite showed fast and reversible change in chemo-electrical property. The ranking of relative resistance response of the composite was methanol < ethanol < 1-propanol < 1-butanol.

  3. Structure and thermodynamics of core-softened models for alcohols

    SciTech Connect

    Munaò, Gianmarco; Urbic, Tomaz

    2015-06-07

    The phase behavior and the fluid structure of coarse-grain models for alcohols are studied by means of reference interaction site model (RISM) theory and Monte Carlo simulations. Specifically, we model ethanol and 1-propanol as linear rigid chains constituted by three (trimers) and four (tetramers) partially fused spheres, respectively. Thermodynamic properties of these models are examined in the RISM context, by employing closed formulæ for the calculation of free energy and pressure. Gas-liquid coexistence curves for trimers and tetramers are reported and compared with already existing data for a dimer model of methanol. Critical temperatures slightly increase with the number of CH{sub 2} groups in the chain, while critical pressures and densities decrease. Such a behavior qualitatively reproduces the trend observed in experiments on methanol, ethanol, and 1-propanol and suggests that our coarse-grain models, despite their simplicity, can reproduce the essential features of the phase behavior of such alcohols. The fluid structure of these models is investigated by computing radial distribution function g{sub ij}(r) and static structure factor S{sub ij}(k); the latter shows the presence of a low−k peak at intermediate-high packing fractions and low temperatures, suggesting the presence of aggregates for both trimers and tetramers.

  4. Electron beam induced synthesis of uranium dioxide nanoparticles: Effect of solvent composition

    NASA Astrophysics Data System (ADS)

    Rath, M. C.; Keny, S. J.; Naik, D. B.

    2016-09-01

    The effect of various compositions of solvents was investigated on the electron beam induced synthesis of uranium dioxide, UO2 nanoparticles. The synthesis was carried out at different pHs from 2 to 7 in the aqueous solutions containing 10 mM uranyl nitrate and 10% 2-propanol. The formation of UO2 nanoparticles was found to occur only in the pH range from 2.5 to 3.7. Experiments were also carried out in the aqueous solutions containing various other alcohols (10% v/v) such as methanol, ethanol, 1-propanol, 1-butanol or tert-butanol as well as in solutions containing 10 mM sodium formate at pH 3.4. The formation of UO2 nanoparticles in the aqueous solutions was found to occur only in the presence of ethanol, 1-propanol, 2-propanol or 1-butanol. It is therefore confirmed that the electron beam induced synthesis of UO2 nanoparticles strongly depends on the solvent compositions as well as the pH of the medium.

  5. CEC column behaviour of butyl and lauryl methacrylate monoliths prepared in non-aqueous media.

    PubMed

    Cantó-Mirapeix, Amparo; Herrero-Martínez, José M; Mongay-Fernández, Carlos; Simó-Alfonso, Ernesto F

    2009-02-01

    Polymeric monolithic stationary phases for capillary electrochromatography were prepared using two bulk monomers, butyl methacrylate (BMA) and lauryl methacrylate (LMA), by in situ polymerization in non-aqueous media. The effect of 1,4-butanediol/1-propanol ratio on porous properties was investigated separately for each monomer, keeping the proportion of monomers to pore-forming solvents fixed at 40:60 wt:wt. Also, mixtures of BMA and LMA at different 1,4-butanediol/1-propanol ratios were studied for tailoring the morphological features of the monolithic columns. The chromatographic performance of the different columns was evaluated by means of van Deemter plots of polycyclic aromatic hydrocarbons. Mercury-intrusion porosimetry, SEM, and nitrogen-adsorption measurements were also performed in order to understand their retention behaviour and porous properties. A comparison of these features was also performed for monoliths made with one bulk monomer (BMA or LMA) and with mixtures of both. These mixed monoliths showed satisfactory efficiencies and analysis times compared with those made with one bulk monomer; thus, the BMA-LMA monoliths constitute an attractive alternative to manipulate the electrochromatographic properties of methacrylate beds in CEC. PMID:19170053

  6. Solvation of exchangeable Cu/sup 2 +/ cations by primary alcohols in montmorillonite clay studied by electron spin resonance and electron spin echo modulation spectroscopies

    SciTech Connect

    Brown, D.R.; Kevan, L.

    1988-04-07

    A montmorillonite clay (STx-1), with Mg/sup 2 +/ as the major exchangeable cation and Cu/sup 2 +/ exchanged into 5% of the Mg/sup 2 +/ sites, is used to study the interaction between the exchangeable cations and adsorbed primary alcohols, methanol, ethanol, and 1-propanol, in the clay interlayer region. Electron spin resonance (ESR) shows that, on saturation of the clay with methanol, a freely rotating Cu/sup 2 +/ center is formed in the clay interlayer. Electron spin echo modulation (ESEM) spectroscopy indicates that the center is a four-coordinate Cu/sup 2 +/ solvate, in which the methanol ligands are in a square-planar configuration. On adsorption of ethanol into the interlayer region, a rotationally restricted Cu/sup 2 +/ center is detected. ESEM again indicates a four-coordinate, square-planar solvate, and ESR of oriented clay films reveals that the major symmetry axis of the ethanol-solvated Cu/sup 2 +/ center is perpendicular to the plane of the clay lattice. Similar ESP data are reported for 1-propanol-saturated montmorillonite, and a four-coordinate, square-planar Cu/sup 2 +/ solvate, similar to that described for ethanol, is proposed.

  7. Efficient yet accurate approximations for ab initio calculations of alcohol cluster thermochemistry

    NASA Astrophysics Data System (ADS)

    Umer, Muhammad; Kopp, Wassja A.; Leonhard, Kai

    2015-12-01

    We have calculated the binding enthalpies and entropies of gas phase alcohol clusters from ethanol to 1-decanol. In addition to the monomers, we have investigated dimers, tetramers, and pentamers. Geometries have been obtained at the B3LYP/TZVP level and single point energy calculations have been performed with the Resolution of the Identity-MP2 (RIMP2) method and basis set limit extrapolation using aug-cc-pVTZ and aug-cc-pVQZ basis sets. Thermochemistry is calculated with decoupled hindered rotor treatment for large amplitude motions. The results show three points: First, it is more accurate to transfer the rigid-rotor harmonic oscillator entropies from propanol to longer alcohols than to compute them with an ultra-fine grid and tight geometry convergence criteria. Second, the computational effort can be reduced considerably by using dimerization energies of longer alcohols at density functional theory (B3LYP) level plus a RIMP2 correction obtained from 1-propanol. This approximation yields results almost with the same accuracy as RIMP2 — both methods differ for 1-decanol only 0.4 kJ/mol. Third, the entropy of dimerization including the hindered rotation contribution is converged at 1-propanol with respect to chain length. This allows for a transfer of hindered rotation contributions from smaller alcohols to longer ones which reduces the required computational and man power considerably.

  8. Notes on Vapor Pressure Equilibria Measurements

    NASA Astrophysics Data System (ADS)

    Krieger, Albert G.; Henderson, John W.

    1996-11-01

    After reading the article in this Journal (1), we would like to share our experience with a similar experiment based on an earlier article in this Journal (2). Freshman students at our institution use manometers and 24/40 ground-glass distillation apparatus (abandoned by our organic chemistry classes) to measure boiling points at reduced pressures. Distilled water and 2-methyl-1-propanol are typical liquids of interest. Students enter their collected data into an Excel template which generates graphs of P vs. T and log P vs 1/T to demonstrate the nonlinear and linear relationships that exist between vapor pressures and temperatures. The templates use the Clausius-Clapeyron equation to determine the normal boiling point and the enthalpy of vaporization of the liquid studies. The boiling point determined for water is 100 oC and for 2-methyl-1-propanol is 106 oC, within 2 o of the CRC Handbook data. We have found that the availability of state-of-the-art equipment need not limit the ability to teach and demonstrate fundamental principles. The Excel template (Macintosh) is available upon request domestically and for the cost of international postage for others. Literature Cited 1. Kidahl, N.; Berka, L. H. J. Chem. Educ. 1995, 72, 258. 2. Schaber, P. M. J. Chem. Educ. 1985, 62, 345.

  9. Combination effects of nitrocompounds, pyromellitic diimide, and 2-bromoethanesulfonate on in vitro ruminal methane production and fermentation of a grain-rich feed.

    PubMed

    Zhang, Dan-Feng; Yang, Hong-Jian

    2012-01-11

    An L(16) (4(5)) orthogonal experimental design was used to evaluate combination effects of nitroethane (0-15 mM), 2-nitroethanol (0-15 mM), 2-nitro-1-propanol (0-15 mM), pyromellitic diimide (0-0.07 mM), and 2-bromoethanesulfonate (0-0.05 mM) on in vitro ruminal fermentation of a grain-rich feed. In vitro dry matter disappearance was adversely affected by these inhibitors, while cumulative gas production was not affected. Volatile fatty acid production was increased by nitroethane and 2-bromoethanesulfonate in a dose-dependent manner and was decreased by 2-nitroethanol and pyromellitic diimide. All inhibitor treatments increased the molar acetate proportion, while decreasing proportions of propionate and butyrate; hydrogen recovery was decreased by 36.9-45.2%; and methane production was reduced by 95.2-99.2%. The methanogenesis inhibition ranked: nitroethane > 2-nitroethanol > 2-nitro-1-propanol > 2-bromoethanesulfonate > pyromellitic diimide; combined concentrations of 5, 5, 5, 0.02, and 0.03 mM, respectively, gave the optimal inhibiting efficiency. These results may provide a reference to develop effective mitigation of methane emission from ruminants.

  10. Effects of water-alcohol binary solvents on the thermochemical characteristics of L-tryptophane dissolution at 298.15 K

    NASA Astrophysics Data System (ADS)

    Badelin, V. G.; Smirnov, V. I.

    2013-01-01

    The enthalpies of L-tryptophane solution in water-methanol, water-ethanol, water-1-propanol, and water-2-propanol mixtures at alcohol concentrations of x 2 = 0-0.4 mole fractions were measured by calorimetry. The standard enthalpies of L-tryptophane solution (Δsol H ∘) and transfer (Δtr H ∘) from water to the binary solvent were calculated. The influence of the composition of the water-alcohol mixture and the structure and properties of L-tryptophane on the enthalpy characteristics of the latter was considered. The enthalpy coefficients of pair interactions ( h xy ) of L-tryptophane with alcohol molecules were calculated. The coefficients were positive and increased in the series: methanol (MeOH), ethanol (EtOH), 1-propanol (1-PrOH), and 2-propanol (2-PrOH). The solution and transfer enthalpies of L-tryptophane were compared with those of aliphatic amino acids (glycine, L-threonine, DL-alanine, L-valine, and L-phenylalanine) in similar binary solvents.

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

    PubMed

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

    2014-09-19

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

  12. Biodegradation of bisphenol A and other bisphenols by a gram-negative aerobic bacterium

    SciTech Connect

    Lobos, J.H.; Leib, T.K. ); Tahmun Su )

    1992-06-01

    A novel bacterium designated strain MV1 was isolated from a sludge enrichmet takes from the wastewater treatment plant at a plastics manufacturing facility and shown to degrade 2,2-bis(4-hydroxyphenyl)propane (4,4[prime]-isopropylidenediphenol or bisphenol A). Strain MV1 is a gram-negative, aerobic bacillus that grows on bisphenol A as a sole source of carbon and energy. Total carbon analysis for bisphenol A degradation demonstrated that 60% of the carbon was mineralized to CO[sub 2], 20% was associated with the bacterial cells, and 20% was converted to soluble organic compounds. Metabolic intermediates detected in the culture medium during growth on bisphenol A were identified as 4-hydroxybenzoic acid, 4-hydroxyacetophenone, 2,2-bis(4-hydroxyphenyl)-1-propanol, and 2,3-bis(4-hydroxyphenyl)-1,2-propanediol. Most of the bisphenol A degraded by strain MV1 is cleaved in some way to form 4-hydroxybenzoic acid and 4-hydroxyacetophenone, which are subsequently mineralized or assimilated into cell carbon. In addition, about 20% of the bisphenol A is hydroxylated to form 2,2-bis(4-hydroxyphenyl)-1-propanol, which is slowly biotransformed to 2,3-bis(4-hydroxyphenyl)-1,2-propanediol. Cells that were grown on bisphenol A degraded a variety of bisphenol alkanes, hydroxylated benzoic acids, and hydroxylated acetophenones during resting-cell assays. Transmission electron microscopy of cells grown on bisphenol A revealed lipid storage granules and intracytoplasmic membranes.

  13. Anodic deprotonation of polyaniline films in alcohol solutions

    SciTech Connect

    Susumu Kuwabata, Nobuo Kihira ); Hiroshi Yoneyama

    1993-05-01

    Polyaniline films prepared by electrochemical oxidation of aniline possess high redox activities both in aqueous acidic and in nonaqueous solutions. The high durability of the film against the redox cycling opens applications of this material to electrochromic and electronic devices and cathode-active materials of rechargeable lithium batteries. Polyaniline films immersed in alcohol solutions such as methanol, ethanol, 1-propanol, and 2-propanol are deprotonated by applying anodic potentials. The potential at which the deprotonation reaction is induced to occur is the most negative at methanol among the above four kinds of alcohols used, and ethanol, 1-propanol, and 2-propanol follow in this order. This finding is quantitatively discussed in terms of the difference of the affinity of the solvent for the protonated polyaniline. An equation to predict the potential at which the conductance of polyaniline is decreased to one-half of the highest conductance by the deprotonation is derived, and the validity of the equation is verified for results obtained both in aqueous solutions of different pH values and in the above alcohol solutions. 26 refs., 9 figs.

  14. Dispersive liquid-liquid microextraction of organophosphorous pesticides using nonhalogenated solvents.

    PubMed

    Alves, Andreia Cristina Henriques; Gonçalves, Maria Margarida Pontes Boavida; Bernardo, Maria Manuel Serrano; Mendes, Benilde Simões

    2012-10-01

    Dispersive liquid-liquid microextraction (DLLME) combined with gas chromatography and mass spectrometry (GC-MS) was applied to the determination of five organophosphorous pesticides (OPPs) in water samples. The analytes included in this study were prophos, diazinon, chlorpyrifos methyl, fenchlorphos, and chlorpyrifos. The use of nonhalogenated solvents (cyclohexane, heptane, and octane) as extraction solvents was investigated using acetone, acetonitrile, or methanol, as dispersion solvents. The combination of less polar dispersion solvents (1-propanol and 2-propanol) and nonhalogenated extraction solvents was also studied in dispersive liquid-liquid microextraction for the first time. Several experimental conditions were tested (nature and volume of extraction solvents, nature and volume of dispersion solvents, salting-out effect) and the corresponding enrichment factors and recoveries were evaluated. The best microextraction condition was obtained using 50 μL of cyclohexane and 0.3 mL of 1-propanol. The detection and quantification limits were in the low ppt range, with values between 3.3-8.0 ng/L and 11.0-26.6 ng/L, respectively. Relative standard deviations were between 6.6 and 13.1% for a fortification level of 500 ng/L. At the same fortification level, the relative recoveries (RR) of Alvito's dam water, Judeu's river water, and well water samples were in the range of 50.3-97.1%.

  15. Potassium sorbate reduces production of ethanol and 2 esters in corn silage.

    PubMed

    Hafner, Sasha D; Franco, Roberta B; Kung, Limin; Rotz, C Alan; Mitloehner, Frank

    2014-12-01

    The objective of this work was to evaluate the effects of biological and chemical silage additives on the production of volatile organic compounds (VOC; methanol, ethanol, 1-propanol, methyl acetate, and ethyl acetate) within corn silage. Recent work has shown that silage VOC can contribute to poor air quality and reduce feed intake. Silage additives may reduce VOC production in silage by inhibiting the activity of bacteria or yeasts that produce them. We produced corn silage in 18.9-L bucket silos using the following treatments: (1) control (distilled water); (2) Lactobacillus buchneri 40788, with 400,000 cfu/g of wet forage; (3) Lactobacillus plantarum MTD1, with 100,000 cfu/g; (4) a commercial buffered propionic acid-based preservative (68% propionic acid, containing ammonium and sodium propionate and acetic, benzoic, and sorbic acids) at a concentration of 1 g/kg of wet forage (0.1%); (5) a low dose of potassium sorbate at a concentration of 91 mg/kg of wet forage (0.0091%); (6) a high dose of potassium sorbate at a concentration of 1g/kg of wet forage (0.1%); and (7) a mixture of L. plantarum MTD1 (100,000 cfu/g) and a low dose of potassium sorbate (91 mg/kg). Volatile organic compound concentrations within silage were measured after ensiling and sample storage using a headspace gas chromatography method. The high dose of potassium sorbate was the only treatment that inhibited the production of multiple VOC. Compared with the control response, it reduced ethanol by 58%, ethyl acetate by 46%, and methyl acetate by 24%, but did not clearly affect production of methanol or 1-propanol. The effect of this additive on ethanol production was consistent with results from a small number of earlier studies. A low dose of this additive does not appear to be effective. Although it did reduce methanol production by 24%, it increased ethanol production by more than 2-fold and did not reduce the ethyl acetate concentration. All other treatments increased ethanol production

  16. Odorous gaseous emissions as influence by process condition for the forced aeration composting of pig slaughterhouse sludge

    SciTech Connect

    Blazy, V.; Guardia, A. de; Benoist, J.C; Daumoin, M.; Lemasle, M.; Wolbert, D.; Barrington, S.

    2014-07-15

    Highlights: • The gaseous emissions produced by various composting process conditions were characterized and quantified. • Nine compounds were potentially odorous: TMA, NH{sub 3}, 2-pentanone, 1-propanol-2-methyl, acetophenone and sulphur forms. • The tested composting process conditions reduced odour emissions by a factor of 5–10. • A reduction of 10{sup 5} to 10{sup 6} is required to reach an odour threshold limit at peak event emissions. • Both aeration rate and bulking agent had the most impact on reducing odour emissions. - Abstract: Compost sustainability requires a better control of its gaseous emissions responsible for several impacts including odours. Indeed, composting odours have stopped the operation of many platforms and prevented the installation of others. Accordingly, present technologies collecting and treating gases emitted from composting are not satisfactory and alternative solutions must be found. Thus, the aim of this paper was to study the influence of composting process conditions on gaseous emissions. Pig slaughterhouse sludge mixed with wood chips was composted under forced aeration in 300 L laboratory reactors. The process conditions studied were: aeration rate of 1.68, 4.03, 6.22, 9.80 and 13.44 L/h/kg of wet sludge; incorporation ratio of 0.55, 0.83 and 1.1 (kg of wet wood chips/kg of wet sludge), and; bulking agent particles size of <10, 10 < 20 and 20 < 30 mm. Out-going gases were sampled every 2 days and their composition was analysed using gas chromatography coupled with mass spectrometry (GC–MS). Fifty-nine compounds were identified and quantified. Dividing the cumulated mass production over 30 days of composting, by odour threshold, 9 compounds were identified as main potential odour contributors: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone, 1-propanol-2-methyl, dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide and acetophenone. Five gaseous compounds were correlated with both aeration rate and

  17. Ionic association and solvation of the ionic liquid 1-hexyl-3-methylimidazolium chloride in molecular solvents revealed by vapor pressure osmometry, conductometry, volumetry, and acoustic measurements.

    PubMed

    Sadeghi, Rahmat; Ebrahimi, Nosaibah

    2011-11-17

    A systematic study of osmotic coefficient, conductivity, volumetric and acoustic properties of solutions of ionic liquid 1-hexyl-3-methylimidazolium chloride ([C(6)mim][Cl]) in various molecular solvents has been made at different temperatures in order to study of ionic association and solvation behavior of [C(6)mim][Cl] in different solutions. Precise measurements on electrical conductances of solutions of [C(6)mim][Cl] in water, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and acetonitrile at 293.15, 298.15, and 303.15 K are reported and analyzed with Barthel's low-concentration chemical model (lcCM) to obtain the limiting molar conductivities and association constants of this ionic liquid in the investigated solvents. Strong ion pairing was found for the ionic liquid in 2-propanol, 1-butanol, and 1-propanol, whereas ion association in acetonitrile, methanol and ethanol is rather weak and in water the ionic liquid is fully dissociated. In the second part of this work, the apparent molar volumes and isentropic compressibilities of [C(6)mim][Cl] in water, methanol, ethanol, acetonitrile, 1-propanol, 2-propanol, and 1-butanol are obtained at the 288.15-313.15 K temperature range at 5 K intervals at atmospheric pressure from the precise measurements of density and sound velocity. The infinite dilution apparent molar volume and isentropic compressibility values of the free ions and ion pairs of [C(6)mim][Cl] in the investigated solvents as well as the excess molar volume of the investigated solutions are determined and their variations with temperature and type of solvents are also studied. Finally, the experimental measurements of osmotic coefficient at 318.15 K for binary solutions of [C(6)mim][Cl] in water, methanol, ethanol, 2-propanol, and acetonitrile are taken using the vapor pressure osmometry (VPO) method and from which the values of the solvent activity, vapor pressure, activity coefficients, and Gibbs free energies are calculated. The results are

  18. Preparation of microemulsions using polyglycerol fatty acid esters as surfactant for the delivery of protein drugs.

    PubMed

    Ho, H O; Hsiao, C C; Sheu, M T

    1996-02-01

    Phase diagrams containing the microemulsion region were constructed for pseudo-ternary systems composed for polyglycerol fatty acid ester/cosurfactant/Captex 300/water. It was found necessary to add ethanol, 1-propanol, 1-butanol as cosurfactant to produce microemulsions. The results also demonstrated microemulsions were only able to form when employing polyglycerol fatty acid esters with hydrophile-lipophile balances (HLBs) between 8 and 13, such as MO500, MO750, SO750, and ML310. Most microemulsions were determined to be Winsor type IV by dilution and dye solubility tests. Microemulsions stored at ambient temperature maintained constant viscosity, indicating that the system was thermodynamically stable for long periods. Further, several microemulsion formulations were demonstrated to be promising for oral delivery of insulin based on the results of stability tests and acid-protection efficiency.

  19. Effects of resonant phonon scattering from internal molecular modes on the thermal conductivity of molecular glasses

    NASA Astrophysics Data System (ADS)

    Krivchikov, A. I.; Yushchenko, A. N.; Korolyuk, O. A.; Bermejo, F. J.; Fernandez-Perea, R.; Bustinduy, I.; González, M. A.

    2008-01-01

    The thermal conductivity κ(T) of the crystalline and glassy phases of the two isomers of propyl alcohol has been measured. The two isomers differ by a minor chemical detail involving the position of the hydroxyl group with respect to the carbon backbone. Such a difference in molecular structure leads, however, to disparate behaviors for the temperature dependence of κ(T) , for both glass and crystal states. The κ(T) for the glass shows for 1-propanol an anomalously large plateau region comprising temperatures within 6-90K , while data for isomeric 2-propanol show only a small plateau up to 10K which is comparable to data on lower alcohols. The results emphasize the role played by internal molecular degrees of freedom as sources of strong resonant phonon scattering.

  20. Experimental Determination of Densities and Isobaric Vapor-Liquid Equilibria of Methyl Acetate and Ethyl Acetate with Alcohols (C3 and C4) at 0.3 MPa

    NASA Astrophysics Data System (ADS)

    Susial, Pedro; Estupiñan, Esteban J.; Castillo, Victor D.; Rodríguez-Henríquez, José J.; Apolinario, José C.

    2013-10-01

    The densities and excess volumes were determined at 298.15 K for the methyl acetate + 1-propanol, methyl acetate + 1-butanol, and ethyl acetate + 1-butanol mixtures. The vapor-liquid equilibria data at 0.3 MPa for these binary systems were obtained using a stainless steel equilibrium still. The activity coefficients were obtained from the experimental data using the Hayden and O’Connell method and the Yen and Woods equation. The binary systems in this study showed positive deviations from ideality. The experimental VLE data were verified with the point-to-point test of van Ness using the Barker routine and the Fredenslund criterion. The different versions of the UNIFAC and the ASOG group contribution models were applied.

  1. Metabolic Engineering of Microorganisms for the Production of Higher Alcohols

    PubMed Central

    Choi, Yong Jun; Lee, Joungmin; Jang, Yu-Sin

    2014-01-01

    ABSTRACT Due to the increasing concerns about limited fossil resources and environmental problems, there has been much interest in developing biofuels from renewable biomass. Ethanol is currently used as a major biofuel, as it can be easily produced by existing fermentation technology, but it is not the best biofuel due to its low energy density, high vapor pressure, hygroscopy, and incompatibility with current infrastructure. Higher alcohols, including 1-propanol, 1-butanol, isobutanol, 2-methyl-1-butanol, and 3-methyl-1-butanol, which possess fuel properties more similar to those of petroleum-based fuel, have attracted particular interest as alternatives to ethanol. Since microorganisms isolated from nature do not allow production of these alcohols at high enough efficiencies, metabolic engineering has been employed to enhance their production. Here, we review recent advances in metabolic engineering of microorganisms for the production of higher alcohols. PMID:25182323

  2. Process control of apple winemaking by low-resolution gas-phase Fourier-transform infrared spectroscopy.

    PubMed

    Ahro, M; Hakala, M; Kauppinen, J; Kallio, H

    2001-10-01

    Four apple wine fermentation processes have been observed by means of direct-inlet gas-phase FTIR spectroscopy. The apple juice concentrates were each fermented by two species of Saccharomyces cerevisiae starters, and the experiment was repeated. The development of the concentrations of 1-propanol, 4-methylpyridine, acetaldehyde, acetic acid, and ethyl acetate was monitored. Two different sampling methods were used--static headspace and direct injection of the must. The performance of the FTIR method is limited by the high ethanol concentration. It can be mathematically proven that the amount of sample can be selected so that any distortion due to ethanol is minimized. Headspace GC-MS was used for preliminary compound identification.

  3. Diffusion in mixed solvents. II - The heat of mixing parameter

    NASA Technical Reports Server (NTRS)

    Carapellucci, P. A.

    1975-01-01

    Correlation of second-order rate constants for many reactions involving electron transfer between organic molecules, solvated electron reactions, iodine diffusion coefficients, and triplet state electron transfer reactions has been made with the heat of mixing parameter (HMP) for the aqueous binary solvent systems. The aqueous binary solvents studied are those containing methanol or ethanol (type I solvent); 1-propanol or tert-butyl alcohol (type II solvent); or sucrose or glycerol (type III solvent). A plot of the HMP vs. the diffusion parameter for each reaction yields superimposable curves for these reactions in a particular solvent mixture over the entire solvent mixture range, irrespective of the value of the reaction's rate constant or diffusion coefficient in water.

  4. A study on corrosion resistant graphene films on low alloy steel

    NASA Astrophysics Data System (ADS)

    Sai Pavan, A. S.; Ramanan, Sutapa Roy

    2016-04-01

    Graphene nanosheets were produced after synthesizing graphene oxide via Hummer's method and a modified Hummer's method. The obtained graphene after reduction was dispersed in 1-propanol to get a coating solution. Mild steel coupons were coated with the graphene solution via dip coating method. Corrosion studies were carried out at different environments like water (pH 6.0), HCl (0.1 N), NaCl (3.5 wt%) and NaOH (1 M). Tafel analysis showed a reduction in the corrosion rate up to 99 % after three layer deposition with the graphene developed using the modified Hummer's method. X-ray diffraction and Raman Spectroscopy confirmed the presence of graphene.

  5. Phase Transition of a Structure II Cubic Clathrate Hydrate to a Tetragonal Form.

    PubMed

    Takeya, Satoshi; Fujihisa, Hiroshi; Yamawaki, Hiroshi; Gotoh, Yoshito; Ohmura, Ryo; Alavi, Saman; Ripmeester, John A

    2016-08-01

    The crystal structure and phase transition of cubic structure II (sII) binary clathrate hydrates of methane (CH4 ) and propanol are reported from powder X-ray diffraction measurements. The deformation of host water cages at the cubic-tetragonal phase transition of 2-propanol+CH4 hydrate, but not 1-propanol+CH4 hydrate, was observed below about 110 K. It is shown that the deformation of the host water cages of 2-propanol+CH4 hydrate can be explained by the restriction of the motion of 2-propanol within the 5(12) 6(4) host water cages. This result provides a low-temperature structure due to a temperature-induced symmetry-lowering transition of clathrate hydrate. This is the first example of a cubic structure of the common clathrate hydrate families at a fixed composition. PMID:27346760

  6. Fragrance contact dermatitis - a worldwide multicenter investigation (Part III).

    PubMed

    Larsen, Walter; Nakayama, Hideo; Fischer, Torkil; Elsner, Peter; Frosch, Peter; Burrows, Desmond; Jordan, William; Shaw, Stephanie; Wilkinson, John; Marks, James; Sugawara, M; Nethercott, Marc; Nethercott, James

    2002-03-01

    The purpose of this study was to determine the frequency of responses to selected fragrance materials in patients who were fragrance sensitive. 218 fragrance sensitive subjects were evaluated in eight centres worldwide with a fragrance mixture (FM) and 17 less well-studied fragrance materials. Reaction to the fragrance mixture (FM) occurred in 76% of the subjects. The (FM) detected all reactions to nerol and hydroxycitronellol and 93% of the reactions to clove bud oil. Ten fragrance materials were not detected by the FM and deserve further study: benzenepropanol, beta, beta, 3-trimethyl, hexyl-salicylate, dl-citronellol, synthetic ylang ylang oil, benzyl mixture, cyclohexyl-acetate, eugenyl methyl ether, isoeugenyl methyl ether, 3-phenyl-1-propanol, and 3, 7-dimethyl-7-methoxyoctan-2-ol.

  7. Acetic Acid Increases Stability of Silage under Aerobic Conditions

    PubMed Central

    Danner, H.; Holzer, M.; Mayrhuber, E.; Braun, R.

    2003-01-01

    The effects of various compounds on the aerobic stability of silages were evaluated. It has been observed that inoculation of whole-crop maize with homofermentative lactic acid bacteria leads to silages which have low stability against aerobic deterioration, while inoculation with heterofermentative lactic acid bacteria, such as Lactobacillus brevis or Lactobacillus buchneri, increases stability. Acetic acid has been proven to be the sole substance responsible for the increased aerobic stability, and this acid acts as an inhibitor of spoilage organisms. Therefore, stability increases exponentially with acetic acid concentration. Only butyric acid has a similar effect. Other compounds, like lactic acid, 1,2-propanediol, and 1-propanol, have been shown to have no effect, while fructose and mannitol reduce stability. PMID:12514042

  8. SO3H-functionalized ionic liquid: efficient catalyst for bagasse liquefaction.

    PubMed

    Long, Jinxing; Guo, Bin; Teng, Junjiang; Yu, Yinghao; Wang, Lefu; Li, Xuehui

    2011-11-01

    Liquefaction is a process for the production of biofuel or value-added biochemicals from non-food biomass. SO(3)H-, COOH-functionalized and HSO(4)-paired imidazolium ionic liquids were shown to be efficient catalysts for bagasse liquefaction in hot compressed water. Using SO(3)H-functionalized ionic liquid, 96.1% of bagasse was liquefied and 50.6% was selectively converted to low-boiling biochemicals at 543 K. The degree of liquefaction and selectivity for low-boiling products increased and the average molecular weight of the tetrahydrofuran soluble products decreased with increasing acidic strength of ionic liquids. Analysis of products and comparative characterization of raw materials and residues suggested that both catalytic liquefaction and hydrolysis processes contribute to the high conversion of bagasse. A possible liquefaction mechanism based on the generation of 3-cyclohexyl-1-propanol, one of the main products, is proposed. PMID:21906936

  9. Use of a flor velum yeast for modulating colour, ethanol and major aroma compound contents in red wine.

    PubMed

    Moreno, Juan; Moreno-García, Jaime; López-Muñoz, Beatriz; Mauricio, Juan Carlos; García-Martínez, Teresa

    2016-12-15

    The most important and negative effect of the global warming for winemakers in warm and sunny regions is the observed lag between industrial and phenolic grape ripeness, so only it is possible to obtain an acceptable colour when the ethanol content of wine is high. By contrast, the actual market trends are to low ethanol content wines. Flor yeast growing a short time under velum conditions, decreases the ethanol and volatile acidity contents, has a favorable effect on the colour and astringency and significantly changes the wine content in 1-propanol, isobutanol, acetaldehyde, 1,1-diethoxiethane and ethyl lactate. The Principal Component Analysis of six enological parameters or five aroma compounds allows to classify the wines subjected to different velum formation conditions. The obtained results in two tasting sessions suggest that the flor yeast helps to modulate the ethanol, astringency and colour and supports a new biotechnological perspective for red winemakers. PMID:27451159

  10. Ultrasonic relaxation studies of mixed micelles formed from alcohol-decyltrimethylammonium bromide-water

    SciTech Connect

    Jobe, D.J.; Verrall, R.E.; Skalski, B.

    1992-08-06

    This paper discusses how ultrasonic relaxation and conductance studies of alcohol (1-pentanol or 1-butanol)-DTAB-water mixed micelles reveal two relaxation frequencies related to the exchange of monomer surfactant and of alcohol between the micelles and the bulk phase. Conductance and time-resolved fluorescence measurements were used to obtain the alcohol distribution coefficients, micelle ionization, critical micellar concentration, and the alcohol and surfactant mean aggregation numbers. Using two models (Aniansson and Hall & Wyn-Jones), information about the forward and backward rate constants, polydispersity of the mixed micelles and the change in volumes of the two exchange processes are obtained and compared with 1-propanol-DTAB-water. Alcohol chain length influence on thermodynamics and kinetics is also discussed. 16 refs., 12 figs., 6 tabs.

  11. PMR-15 polyimide modifications for improved prepreg tack

    NASA Technical Reports Server (NTRS)

    Vannucci, R. D.

    1982-01-01

    The use of mixed solvents and of modified monomeric ester reactants was investigated as a means of improving the tack and drape retention characteristics of PMR-15 polyimide prepreg. Methanol, ethanol, 1-propanol and 1-butanol were used to prepare the esters, prepreg solutions, and T-300 graphite fabric and Celion 6000 unidirectional fiber prepregs. The tack retention characteristics of the T-300 fabric prepreg after exposure to simulated use conditions were determined using a simple lap shear test. Drape was qualitatively assessed by visually monitoring the deformability of the prepreg. Thermo-oxidative stability and mechanical properties retention of the Celion 6000 grahite fiber composites were determined as a function of exposure time in air at 600 F.

  12. Nanorod mediated collagen scaffolds as extra cellular matrix mimics.

    PubMed

    Vedhanayagam, Mohan; Mohan, Ranganathan; Nair, Balachandran Unni; Sreeram, Kalarical Janardhanan

    2015-12-01

    Creating collagen scaffolds that mimic extracellular matrices without using toxic exogenous materials remains a big challenge. A new strategy to create scaffolds through end-to-end crosslinking through functionalized nanorods leading to well-designed architecture is presented here. Self-assembled scaffolds with a denaturation temperature of 110 °C, porosity of 70%, pore size of 0.32 μm and Young's modulus of 231 MPa were developed largely driven by imine bonding between 3-mercapto-1-propanal (MPA) functionalized ZnO nanorods and collagen. The mechanical properties obtained were much higher than that of native collagen, collagen-MPA, collagen-3-mercapto-1-propanol (3MPOH) or collagen- 3-MPOH-ZnO, clearly bringing out the relevance of nanorod mediated assembly of fibrous networks. This new strategy has led to scaffolds with mechanical properties much higher than earlier reports and can provide support for cell growth and facilitation of cell attachment. PMID:26586667

  13. A re-appraisal of the concept of ideal mixtures through a computer simulation study of the methanol-ethanol mixtures

    NASA Astrophysics Data System (ADS)

    Požar, Martina; Lovrinčević, Bernarda; Zoranić, Larisa; Mijaković, Marijana; Sokolić, Franjo; Perera, Aurélien

    2016-08-01

    Methanol-ethanol mixtures under ambient conditions of temperature and pressure are studied by computer simulations, with the aim to sort out how the ideality of this type of mixtures differs from that of a textbook example of an ideal mixture. This study reveals two types of ideality, one which is related to simple disorder, such as in benzene-cyclohexane mixtures, and another found in complex disorder mixtures of associated liquids. It underlines the importance of distinguishing between concentration fluctuations, which are shared by both types of systems, and the structural heterogeneity, which characterises the second class of disorder. Methanol-1propanol mixtures are equally studied and show a quasi-ideality with many respect comparable to that of the methanol-ethanol mixtures, hinting at the existence of a super-ideality in neat mono-ol binary mixtures, driven essentially by the strong hydrogen bonding and underlying hydroxyl group clustering.

  14. Optical constants of alcohols in the infrared

    NASA Technical Reports Server (NTRS)

    Sethna, P. P.; Williams, D.

    1979-01-01

    The spectral reflectances at near-normal incidence for methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol are reported for the spectral range 6700-350 kaysers. The real and imaginary parts of the complex index of refraction of these liquids are obtained in the range 4000-400 kaysers by use of Kramers-Kronig phase-shift analysis. For all of the alcohols studied, the strength for the OH-stretch bands is directly proportional to the number of OH groups per unit volume; similar relations are established for CH- and CO-stretch bands. Absorption cross sections for stretch vibrations of the three groups are considered, and the role of characteristic group intensities in intensity spectroscopy is discussed.

  15. Fragrance contact dermatitis - a worldwide multicenter investigation (Part III).

    PubMed

    Larsen, Walter; Nakayama, Hideo; Fischer, Torkil; Elsner, Peter; Frosch, Peter; Burrows, Desmond; Jordan, William; Shaw, Stephanie; Wilkinson, John; Marks, James; Sugawara, M; Nethercott, Marc; Nethercott, James

    2002-03-01

    The purpose of this study was to determine the frequency of responses to selected fragrance materials in patients who were fragrance sensitive. 218 fragrance sensitive subjects were evaluated in eight centres worldwide with a fragrance mixture (FM) and 17 less well-studied fragrance materials. Reaction to the fragrance mixture (FM) occurred in 76% of the subjects. The (FM) detected all reactions to nerol and hydroxycitronellol and 93% of the reactions to clove bud oil. Ten fragrance materials were not detected by the FM and deserve further study: benzenepropanol, beta, beta, 3-trimethyl, hexyl-salicylate, dl-citronellol, synthetic ylang ylang oil, benzyl mixture, cyclohexyl-acetate, eugenyl methyl ether, isoeugenyl methyl ether, 3-phenyl-1-propanol, and 3, 7-dimethyl-7-methoxyoctan-2-ol. PMID:12000321

  16. Cytotoxicity of enantiomers of gossypol Schiff's bases and optical stability of gossypolone.

    PubMed

    Dao, Vi-Thuy; Dowd, Michael K; Martin, Marie-Thérèse; Gaspard, Christiane; Mayer, Michel; Michelot, Robert J

    2004-07-01

    Optical Schiff's bases of gossypol were prepared with chiral gossypol and ethylamine. As has been similarly observed among the gossypol enantiomers, the (-)-gossypol ethylimine was more active than either the (+)-gossypol ethylimine or the racemic gossypol ethylimine against KB and MCF7 cells. Gossypolone was also observed to be more toxic than gossypol against both cell lines. All of the gossypol products tested showed comparable toxicity toward MCF7/ADR (adriblastine-resistant) cells. Attempts at producing chiral gossypolone from chiral gossypol failed because of rapid racemization. In addition, the Schiff's base derivatives of gossypolone formed with R-(+)-2-amino-3-phenyl-1-propanol could only be separated at reduced temperature, indicating that gossypolone Schiff's bases are less optical stable than gossypol Schiff's bases.

  17. Enhancement of radiopharmaceutical excretion by chemical interventions

    SciTech Connect

    Oster, Z.H.; Som, P.; Brill, A.B.; Sacker, D.F.; Atkins, H.L.

    1982-01-01

    The goal was to find methods of decreasing the radiation dose after radionuclide studies, by giving a compound that will increase the rate of excretion of the radionuclide. Sprague - 1 Dawley rats were given Tc-99m pertechnetate, Ga-67 citrate or Tl-201 chloride intravenously followed at intervals of 1 to 24 hours by one of the following compounds: desferroxamine (DFO), 2,3-dimercapto-1-propanol (BAL), triethylene tetraamine hexaacetic acid (TETHA), stannous tartarate, bleomycin (BLEO), 2,3-dimercaptosuccinic acid (DMSA), diethylene-triaminepentaacetic acid (DTPA), DTPA+SnCl.2H/sub 2/O, dihydroxybenzoic acid (DHB), and ferric-cyanoferrate (IT)(Prussian blue, PB). All the agents except PB are chelators. Some of these agents enhance excretion through the urinary tract (DFO), while most are excreted through the bile. PB was shown to increase Cs excrection through the G.I. tract. (ACR)

  18. Comparison of chiral electrophoretic separation methods for phenethylamines and application on impurity analysis.

    PubMed

    Borst, Claudia; Holzgrabe, Ulrike

    2010-12-15

    A chiral microemulsion electrokinetic chromatography method has been developed for the separation of the enantiomers of the phenethylamines ephedrine, N-methylephedrine, norephedrine, pseudoephedrine, adrenaline (epinephrine), 2-amino-1-phenylethanol, diethylnorephedrine, and 2-(dibutylamino)-1-phenyl-1-propanol, respectively. The separations were achieved using an oil-in-water microemulsion consisting of the oil-component ethyl acetate, the surfactant sodium dodecylsulfate, the cosurfactant 1-butanol, the organic modifier propan-2-ol and 20mM phosphate buffer pH 2.5 as aqueous phase. For enantioseparation sulfated beta-cyclodextrin was added. The method was compared to an already described CZE method, which made use of heptakis(2,3-di-O-diacetyl-6-O-sulfo)-beta-cyclodextrin (HDAS) as chiral selector. Additionally, the developed method was successfully applied to the related substances analysis of noradrenaline, adrenaline, dipivefrine, ephedrine and pseudoephedrine monographed in the European Pharmacopoeia 6.

  19. SO3H-functionalized ionic liquid: efficient catalyst for bagasse liquefaction.

    PubMed

    Long, Jinxing; Guo, Bin; Teng, Junjiang; Yu, Yinghao; Wang, Lefu; Li, Xuehui

    2011-11-01

    Liquefaction is a process for the production of biofuel or value-added biochemicals from non-food biomass. SO(3)H-, COOH-functionalized and HSO(4)-paired imidazolium ionic liquids were shown to be efficient catalysts for bagasse liquefaction in hot compressed water. Using SO(3)H-functionalized ionic liquid, 96.1% of bagasse was liquefied and 50.6% was selectively converted to low-boiling biochemicals at 543 K. The degree of liquefaction and selectivity for low-boiling products increased and the average molecular weight of the tetrahydrofuran soluble products decreased with increasing acidic strength of ionic liquids. Analysis of products and comparative characterization of raw materials and residues suggested that both catalytic liquefaction and hydrolysis processes contribute to the high conversion of bagasse. A possible liquefaction mechanism based on the generation of 3-cyclohexyl-1-propanol, one of the main products, is proposed.

  20. Solute-solvent interactions in micellar electrokinetic chromatography: V. Factors that produce peak splitting.

    PubMed

    Ràfols, Clara; Poza, Ana; Fuguet, Elisabet; Rosés, Martí; Bosch, Elisabeth

    2002-08-01

    The experimental conditions that produce analyte peak splitting in micellar electrokinetic capillary chromatography (MEKC) have been systematically investigated. The system studied was a neutral phosphate buffer and sodium dodecyl sulfate (SDS) micelles as pseudostationary phase. A number of analytes showing a wide variety of hydrophobicity values and several organic solvents as sample diluents have been tested. Peak splitting phenomena are mainly due to the presence of organic solvent in the sample solution. They increase with the hydrophobicity of the analyte and decrease with the increase of the surfactant concentration. When hydrophobic compounds are analyzed the suggested ways to avoid split peaks are: (i) the use of 1-propanol or 1-butanol as sample diluent instead of methanol or acetonitrile or (ii) the use of high concentration of surfactant in the separating solution when the analyte must be dissolved in pure methanol or acetonitrile.

  1. Analysis of pharmaceutical preparations containing antihistamine drugs by micellar liquid chromatography.

    PubMed

    Martínez-Algaba, C; Bermúdez-Saldaña, J M; Villanueva-Camañas, R M; Sagrado, S; Medina-Hernández, M J

    2006-02-13

    Rapid chromatographic procedures for analytical quality control of pharmaceutical preparations containing antihistamine drugs, alone or together with other kind of compounds are proposed. The method uses C18 stationary phases and micellar mobile phases of cetyltrimethylammonium bromide (CTAB) with either 1-propanol or 1-butanol as organic modifier. The proposed procedures allow the determination of the antihistamines: brompheniramine, chlorcyclizine, chlorpheniramine, diphenhydramine, doxylamine, flunarizine, hydroxyzine, promethazine, terfenadine, tripelennamine and triprolidine, in addition to caffeine, dextromethorphan, guaifenesin, paracetamol and pyridoxine in different pharmaceutical presentations (tablets, capsules, suppositories, syrups and ointments). The methods require minimum handling sample and are rapid (between 3 and 12 min at 1 mLmin(-1) flow rate) and reproducible (R.S.D. values<5%). Limits of detection are lower than 1 microgmL(-1) and the recoveries of the analytes in the pharmaceutical preparations are in the range 100+/-10%.

  2. Nonionic gelation agents prepared from hydroxypropyl guar gum.

    PubMed

    Kono, Hiroyuki; Hara, Hideyuki; Hashimoto, Hisaho; Shimizu, Yuuichi

    2015-03-01

    Nonionic gels were prepared from hydroxypropyl guar gum (HPG) with different molar substitution degrees by crosslinking with ethylene glycol diglycidyl ether (EGDE). FTIR and solid-state NMR spectroscopy revealed that the crosslinking degree of HPG gels increased with the amount of EGDE used during the reaction; this result was also confirmed by the water mobility in the swollen gels. Rheological characterization revealed behaviors typical of true gels, and their viscoelastic behaviors strongly depended on the crosslinking degree. The HPG gels absorbed buffers, aqueous saline, and water, and the absorption was not affected by the ionic strength or pH of the solution. In addition, HPG gels with high crosslinking degrees and molar substitution degrees exhibited gelation ability toward protic organic solvents such as methanol, ethanol, and 1-propanol. These HPG gels may find application as gelation agents for many industrial uses. PMID:25498682

  3. Catalytic activity of carbon nanotubes in the conversion of aliphatic alcohols

    NASA Astrophysics Data System (ADS)

    Zhitnev, Yu. N.; Tveritinova, E. A.; Chernyak, S. A.; Savilov, S. V.; Lunin, V. V.

    2016-06-01

    Carbon nanotubes (CNTs) obtained via the catalytic pyrolysis of hexane at 750°C were studied as the catalysts in conversion of C2-C4 alcohols. The efficiency of CNTs as catalysts in dehydration and dehydrogenation of ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and tert-butanol was studied by means of pulse microcatalysis. The surface and structural characteristics of CNTs are investigated via SEM, TEM, DTA, BET, and XPS. CNTs are shown to be effective catalysts in the conversion of alcohols and do not require additional oxidative treatment. The regularities of the conversion of aliphatic alcohols, related to the properties of the CNTs surface and the structure of the alcohols are identified.

  4. Characterization of volatile components in makgeolli, a traditional Korean rice wine, with or without pasteurization, during storage.

    PubMed

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

    2013-01-01

    Changes in the volatile components of unpasteurized and pasteurized makgeolli during 30 days of storage were investigated by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GC-O). A total of 11 odor-active compounds such as 3-methyl-1-butanol (isoamyl alcohol), 2-methyl-1-butanol, 2,3-butanediol, butanoic acid, 3-methylbutanoic acid (isovaleric acid), 2-methylbutanoic acid, 3-(methylthio)-1-propanol (methionol), 2-phenylethanol, ethyl decanoate, ethyl dodecanoate, and ethyl tetradecanoate were determined in both the pasteurized and unpasteurized makgeolli during 30 days of storage. Although there were no significant differences in the concentrations of odor-active compounds at the initial storage time, most of odor-active compounds were more significantly increased in unpasteurized makgeolli compared to the pasteurized one during the storage period.

  5. Formation of Organic Peroxides and Ethers at Post-Discharge Plasma Plume-Liquid Interfaces

    NASA Astrophysics Data System (ADS)

    Begliarbekov, Milan; Kotowich, Steven; Tarnovsky, Vladimir

    2009-03-01

    A direct current (DC) micro-hollow cathode plasma source operating in a mixed glow-streamer regime was used to generate an atmospheric pressure N2 discharge. The post-discharge plume / afterglow was interfaced with a target liquid-phase solution, and caused a change in the chemistry of the target solution. In the present work we study the interaction of an N2 plume with a mixture of 2-methyl-1-propanol and hexane, which results in the formation of organic peroxides and ethers at the plume-liquid interface. The presence of the peroxide and ether functional groups is established by ^1H-NMR, FTIR, and Raman spectra of the reaction products. Fast Atom Bombardment (FAB) mass spectrometry is also used to further characterize the reaction products.

  6. Synthesis of a new cyclosporine-based stationary phase and separation behaviors toward aromatic positional isomers by high-performance liquid chromatography.

    PubMed

    Liu, Wen-na; Fan, Jun; Lin, Chun; Zheng, Sheng-run; Zhang, Wei-guang

    2015-04-01

    A new cyclosporine-bonded stationary phase has been synthesized through the Staudinger reaction between azido cyclosporine A (CsA) and aminopropyl silica gel and applied in separations of six disubstituted aromatic analytes by high-performance liquid chromatography. For dimethyl phthalate, nitroaniline and chloronitrobenzene, their positional isomers were well-separated on this CsA stationary phase, in which the separation factor for m-/o-dimethyl phthalates was the biggest. For nitrotoluene, dichlorobenzene and benzenediol, the m-/o-isomers were co-eluted. Then, effects of chromatographic conditions (such as types and content of alcoholic modifiers) on separation of nitroaniline positional isomers have been investigated. Retention behaviors of nitroaniline isomers on the column exhibited the strengthening trend along with increasing carbon number of alcohols, from ethanol to 1-propanol, and to 1-butanol. A similar phenomenon was observed by lowering the content of alcohol.

  7. [The resolution of racemic sec-phenethyl alcohol on cellulose tribenzoate-based CSP: influence of different alcohols in the mobile phase].

    PubMed

    Wang, L; Lü, S; Gao, P; Li, S

    1999-07-01

    Several primary and secondary alcohols (ethanol, 1-propanol, 2-propanol, 1-butanol) were used as the mobile phase components separately, to investigate their effects on the capacity factor and stereoselectivity of sec-phenethyl alcohol enantiomers on cellulose tribenzoate-based CSP. The chiral recognition mechanism for the enantiomeric aromatic alcohols studied may involve: (1) the aromatic portion of the solute may insert into a chiral cavity of the CSP through a hydrogen bonding interaction between the solute's alcoholic hydrogen and the ester carbonyl group on the CSP; (2) the mobile phase modifiers (various alcohols) compete with the solutes for chiral, as well as achiral, binding sites on the CSP; (3) the structure of the modifier has some effect on stereoselectivity through an alteration of the steric environment of the chiral cavity.

  8. Prebiotic Oxidative Polymerization of 2,3 Dimercaptopropanol on the Surface of Iron(III) Hydroxide Oxide

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.

    1994-01-01

    The oxidation of 2,3-Dimercapto-1-propanol by ferric ions on the surface of iron (III) hydroxide oxide yielded polydisulfide polymers. This polymerization occured readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron (III) hydroxide oxide (20 mg, 160 micro mole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the mineral phase. Reactions at higher dithiol concentrations with the same ratio of dithiol to mineral gave a higher yield of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis will be discussed.

  9. Relationship between membrane fluidity and capping of receptors for concanavalin A.

    PubMed

    Mak, W W; Wong, J T

    1980-12-01

    The activities of a range of phenylalaninol-related compounds on capping of concanavalin A and induction of rounding of Chinese hamster ovary tsHl cells, as well as on the fluidity of phosphatidylcholine-cholesterol (1:1) liposomes, have been examined. These compounds include phenylalaninol, histidinol, leucinol, benzyl alcohol, benzylamine, 2-phenylethanol, 2-phenylamine, 3-phenyl-1-propanol, 3-phenyl-1-propylamine, and 3-phenylpropionic acid. The results indicate a strong correlation between the capacities of these compounds to enhance fluidity and their capacities to inhibit capping of concanavalin A. The specificity of this correlation is suggested by the finding that both types of capacities are poorly correlated with the capacities of the various compounds to induce cell rounding. PMID:6265046

  10. Effect of the composition of a water-alcohol solvent on the thermodynamics of dissolution of DL-α-alanyl-β-alanine at 298.15 K

    NASA Astrophysics Data System (ADS)

    Smirnov, V. I.; Badelin, V. G.

    2014-12-01

    Enthalpies of solution for DL-α-alanyl-β-alanine in H2O-ethanol, H2O-1-propanol, and H2O-2-propanol mixed solvents with the alcohol mole fraction x 2 = 0-0.3 are measured at 298.15 K. Standard enthalpies of solution (Δsol H ∘), standard enthalpies of transfer of DL-α-alanyl-β-alanine from water to binary solvent (Δtr H ∘), and coefficients of enthalpies of pair interactions with alcohol molecules ( h xy) are calculated. The effect the structure and properties of alcohols and the composition of a water-alcohol mixture have on the enthalpy of dissolution for DL-α-alanyl-β-alanine are discussed. The h xy values for dipeptides of the alanine series in water-alcohol binary solvents are compared.

  11. Improved solvent formulations for efficient CO₂ absorption and low-temperature desorption.

    PubMed

    Barzagli, Francesco; Di Vaira, Massimo; Mani, Fabrizio; Peruzzini, Maurizio

    2012-09-01

    This experimental study describes efficient CO₂ capture by 2-amino-2-methyl-1-propanol (AMP)/piperazine (PZ) in ethylene glycol monoethyl ether (EGMEE, 2-ethoxyethanol) containing approximately 15 wt % of water. In these experiments, the solvent is continuously circulated between the absorber (packed-bed reactor at 30, 40, or 45 °C) and the desorber (at 80, 85, or 90 °C). The CO₂ -solvent reaction equilibria have been investigated by using ¹³C NMR spectroscopy, which provides confirmatory evidence that the formation of mono- and biscarbamate derivatives of PZ accounts for most of the CO₂ absorbed by the AMP/PZ/EGMEE/H₂O blend. The solid-state structures of AMP carbamate and of the carbonate salt of protonated AMP have been determined by using XRD. Both AMPCO₂(-) and CO(3)(2-) species completely convert to the monoalkyl carbonates on dissolving the respective salts in methanol, ethanol, or ethylene glycol. PMID:22778091

  12. Electron emission and fragmentation of molecules in intense laser fields

    NASA Astrophysics Data System (ADS)

    Ueda, K.; Prümper, G.; Hatamoto, T.; Okunishi, M.; Mathur, D.

    2007-06-01

    We have constructed an apparatus for high-resolution electron spectroscopy and electron-ion coincidence experiments on gas-phase molecules in intense laser fields. The apparatus comprises an electron time-of-flight (TOF) spectrometer and an ion TOF spectrometer with a position detector, placed on either side of an effusive molecular beam. The ionizing radiation is either the fundamental (800 nm wavelength) of a Ti:sapphire laser or frequency doubled 400-nm light, with pulse durations of ~ 150 fs and the repetition rate of 1 kHz. We have investigated the electron emission and fragmentation of linear alcohol molecules, methanol, ethanol and 1-propanol, in laser fields with peak intensities up to ~ 1×10 14 W/cm2. Details of our apparatus are described along with an overview of some recent results.

  13. Method for producing high surface area chromia materials for catalysis

    DOEpatents

    Gash, Alexander E.; Satcher, Joe; Tillotson, Thomas; Hrubesh, Lawrence; Simpson, Randall

    2007-05-01

    Nanostructured chromium(III)-oxide-based materials using sol-gel processing and a synthetic route for producing such materials are disclosed herein. Monolithic aerogels and xerogels having surface areas between 150 m.sup.2/g and 520 m.sup.2/g have been produced. The synthetic method employs the use of stable and inexpensive hydrated-chromium(III) inorganic salts and common solvents such as water, ethanol, methanol, 1-propanol, t-butanol, 2-ethoxy ethanol, and ethylene glycol, DMSO, and dimethyl formamide. The synthesis involves the dissolution of the metal salt in a solvent followed by an addition of a proton scavenger, such as an epoxide, which induces gel formation in a timely manner. Both critical point (supercritical extraction) and atmospheric (low temperature evaporation) drying may be employed to produce monolithic aerogels and xerogels, respectively.

  14. Kinetic analysis of the denaturation process by alcohols of sodium channels in squid giant axon.

    PubMed Central

    Kukita, F; Mitaku, S

    1993-01-01

    1. The effects of several aliphatic alcohols on sodium currents were examined in the intracellularly perfused squid giant axon when the same concentration of alcohol was applied on both sides of the membrane. 2. An irreversible suppression of sodium currents, accompanied by anaesthesia at high alcohol concentration, was examined in detail using four aliphatic alcohols, that is, ethanol, 1-propanol, 1-butanol and 1-pentanol. 3. This irreversible effect seemed to be attributable to the sequential denaturation of sodium channels, because the kinetics, the current-voltage relation and the sodium channel activation-voltage curve did not change after the sodium current decreased. 4. The time course of the remaining sodium conductance was measured as a function of the sum of the alcohol application time by repeating the process of applying and completely washing out alcohol. The remaining sodium conductance decayed as a function of time in a single exponential manner. This decay time constant depended strongly on the concentration of alcohol and could be assumed to be the denaturation time constant of the sodium channel. 5. The denaturation time constant decreased as the alcohol concentration increased. This time constant is proportional to the Nth power of the alcohol concentration. The N values are 4.3, 4.5, 5.8 and 7.6 for ethanol, 1-propanol, 1-butanol and 1-pentanol, respectively. This implies that alcohol molecules bind to a restricted number of specific sites in the sodium channel protein to cause the denaturation. 6. The concentration of alcohol which caused the same amount of denaturation is related to the exponential function of the carbon number of the alcohol. Considering the partition coefficient of alcohol between lipid and aqueous solution, the concentration of alcohol in the membrane which denatured half of the sodium channels in 2 h can be calculated to be 0.5 M for all alcohols. PMID:8246196

  15. Combustion chemistry of the propanol isomers : investigated by electron ionization and VUV-photoionization molecular-beam mass spectrometry.

    SciTech Connect

    Wang, J.; Kohse-Hoinghaus, Katharina; Cool, Terrill A.; Taatjes, Craig A.; Struckmeier, Ulf; OBwald, Patrick; Morel, Aude; Westmoreland, Phillip R.; Kasper, Tina Silvia

    2008-10-01

    The combustion of 1-propanol and 2-propanol was studied in low-pressure, premixed flat flames using two independent molecular-beam mass spectrometry (MBMS) techniques. For each alcohol, a set of three flames with different stoichiometries was measured, providing an extensive data base with in total twelve conditions. Profiles of stable and intermediate species, including several radicals, were measured as a function of height above the burner. The major-species mole fraction profiles in the 1-propanol flames and the 2-propanol flames of corresponding stoichiometry are nearly identical, and only small quantitative variations in the intermediate species pool could be detected. Differences between flames of the isomeric fuels are most pronounced for oxygenated intermediates that can be formed directly from the fuel during the oxidation process. The analysis of the species pool in the set of flames was greatly facilitated by using two complementary MBMS techniques. One apparatus employs electron ionization (EI) and the other uses VUV light for single-photon ionization (VUV-PI). The photoionization technique offers a much higher energy resolution than electron ionization and as a consequence, near-threshold photoionization-efficiency measurements provide selective detection of individual isomers. The EI data are recorded with a higher mass resolution than the PI spectra, thus enabling separation of mass overlaps of species with similar ionization energies that may be difficult to distinguish in the photoionization data. The quantitative agreement between the EI- and PI-datasets is good. In addition, the information in the EI- and PI-datasets is complementary, aiding in the assessment of the quality of individual burner profiles. The species profiles are supplemented by flame temperature profiles. The considerable experimental efforts to unambiguously assign intermediate species and to provide reliable quantitative concentrations are thought to be valuable for improving

  16. Combustion chemistry of the propanol isomers - investigated by electron ionization and VUV-photoionization molecular-beam mass spectrometry

    SciTech Connect

    Kasper, T.; Osswald, P.; Struckmeier, U.; Kohse-Hoeinghaus, K.; Taatjes, C.A.; Wang, J.; Cool, T.A.; Law, M.E.; Morel, A.; Westmoreland, P.R.

    2009-06-15

    The combustion of 1-propanol and 2-propanol was studied in low-pressure, premixed flat flames using two independent molecular-beam mass spectrometry (MBMS) techniques. For each alcohol, a set of three flames with different stoichiometries was measured, providing an extensive data base with in total twelve conditions. Profiles of stable and intermediate species, including several radicals, were measured as a function of height above the burner. The major-species mole fraction profiles in the 1-propanol flames and the 2-propanol flames of corresponding stoichiometry are nearly identical, and only small quantitative variations in the intermediate species pool could be detected. Differences between flames of the isomeric fuels are most pronounced for oxygenated intermediates that can be formed directly from the fuel during the oxidation process. The analysis of the species pool in the set of flames was greatly facilitated by using two complementary MBMS techniques. One apparatus employs electron ionization (EI) and the other uses VUV light for single-photon ionization (VUV-PI). The photoionization technique offers a much higher energy resolution than electron ionization and as a consequence, near-threshold photoionization-efficiency measurements provide selective detection of individual isomers. The EI data are recorded with a higher mass resolution than the PI spectra, thus enabling separation of mass overlaps of species with similar ionization energies that may be difficult to distinguish in the photoionization data. The quantitative agreement between the EI- and PI-datasets is good. In addition, the information in the EI- and PI-datasets is complementary, aiding in the assessment of the quality of individual burner profiles. The species profiles are supplemented by flame temperature profiles. The considerable experimental efforts to unambiguously assign intermediate species and to provide reliable quantitative concentrations are thought to be valuable for improving

  17. Conversion of 1,3-Propylene Glycol on Rutile TiO2(110)

    SciTech Connect

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

    2014-10-09

    The adsorption of 1,3-propylene glycol (1,3-PG) on partially reduced TiO2(110) and its conversion to products have been studied by a combination of molecular beam dosing and temperature programmed desorption (TPD). When the Ti surface sites are saturated by 1,3-PG, ~80% of the molecules undergo further reactions to yield products that are liberated during the TPD ramp. In contrast to ethylene glycol (EG) and 1,2- propylene glycol (1,2-PG) that yield only alkenes and water at very low coverages (< 0.05 ML), two additional products, HCHO and C2H4, along with propylene (CH3CHCH2) and water are observed for 1,3-PG. Identical TPD line shapes and desorption yields for HCHO and C2H4 suggest that these products result from C-C bond cleavage and are coupled. At higher 1,3-PG coverages (> 0.1 ML), propanal (CH3CH2CHO) and two additional products, 1-propanol (CH3CH2CH2OH) and acrolein (CH2CHCHO), are observed. The desorption of 1-propanol is found to be coupled with the desorption of acrolein, suggesting that these products are formed by the disproportionation of two 1,3-PG molecules. The coverage dependent TPD results further show that propylene formation dominates at low coverages (< 0.3 ML), while the decomposition and disproportionation channels increase rapidly at higher coverages and reach yields comparable to that of propylene at the 1,3-PG saturation coverage of 0.5 ML. The observed surface chemistry clearly shows how the molecular structure of glycols influences their reaction pathways on oxide surfaces.

  18. Contribution of liver alcohol dehydrogenase to metabolism of alcohols in rats.

    PubMed

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

    2015-06-01

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

  19. Gene structure and regulation of alkane monooxygenases in propane-utilizing Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7.

    PubMed

    Kotani, Tetsuya; Kawashima, Yui; Yurimoto, Hiroya; Kato, Nobuo; Sakai, Yasuyoshi

    2006-09-01

    Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7 were isolated from soil samples as propane-utilizing bacteria and were found to be able to utilize various gaseous and liquid n-alkanes as carbon and energy sources. One gene cluster, M-prmABCD, and two gene clusters, P-prm1ABCD and P-prm2ABCD, were cloned from the genomes of Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7, respectively. These gene clusters are homologous to the gene cluster encoding the multicomponent propane monooxygenase (prmABCD) of Gordonia sp. TY-5. The expression of prm gene clusters in Mycobacterium sp. TY-6 and Pseudonocardia sp. TY-7 was shown to be induced by gaseous n-alkanes (C2-C4) except methane, suggesting that the products of these genes are involved in gaseous n-alkane oxidation. Homologous genes for an alkane hydroxylase system (alk system) involved in liquid n-alkane oxidation were also cloned from the genomic DNA of Mycobacterium sp. TY-6. The alk gene cluster was transcribed in response to liquid n-alkanes (C11-C15). These results indicate that Mycobacterium sp. TY-6 has two distinct gene clusters for multicomponent monooxygenases involved in alkane oxidation. Whole-cell reactions revealed that propane is oxidized to 1-propanol through terminal oxidation in Mycobacterium sp. TY-6 and that propane is oxidized to 1-propanol and 2-propanol through both terminal and subterminal oxidations in Pseudonocardia sp. TY-7. This study reveals the diversity of propane metabolism present in microorganisms. PMID:17046531

  20. Biodegradation of propanol and isopropanol by a mixed microbial consortium.

    PubMed

    Bustard, M T; McEvoy, E M; Goodwin, J A; Burgess, J G; Wright, P C

    2000-09-01

    The aerobic biodegradation of high concentrations of 1-propanol and 2-propanol (IPA) by a mixed microbial consortium was investigated. Solvent concentrations were one order of magnitude greater than any previously reported in the literature. The consortium utilized these solvents as their sole carbon source to a maximum cell density of 2.4 x 10(9) cells ml(-1). Enrichment experiments with propanol or IPA as carbon sources were carried out in batch culture and maximum specific growth rates (mumax) calculated. At 20 degrees C, mumax values were calculated to be 0.0305 h(-1) and 0.1093 h(-1) on 1% (v/v) IPA and 1-propanol, respectively. Growth on propanol and IPA was carried out between temperatures of 10 degrees C and 45 degrees C. Temperature shock responses by the microbial consortium at temperatures above 45 degrees C were demonstrated by considerable cell flocculation. An increase in propanol substrate concentration from 1% (v/v) to 2% (v/v) decreased the mumax from 0.1093 h(-1) to 0.0715 h(-1). Maximum achievable biodegradation rates of propanol and IPA were 6.11 x 10(-3)% (v/v) h(-1) and 2.72 x 10(-3)% (v/v) h(-1), respectively. Generation of acetone during IPA biodegradation commenced at 264 h and reached a maximum concentration of 0.4% (v/v). The results demonstrate the potential of mixed microbial consortia in the bioremediation of solvent-containing waste streams.

  1. Effects of solvent hydrogen bonding, viscosity, and polarity on the dispersion and alignment of nanofluids containing Fe2O3 nanoparticles

    NASA Astrophysics Data System (ADS)

    Christensen, Greg; Younes, Hammad; Hong, Haiping; Smith, Pauline

    2015-12-01

    It has been shown that the alignment of Iron (III) oxide (Fe2O3) nanoparticles in water (H2O) can enhance the thermal conductivity of nanofluids. To better understand solvent effects such as hydrogen bonding, viscosity, and polarity, nanofluids were prepared by mixing Fe2O3 nanoparticles and various solvents (water, ethanol, 1-propanol, isopropanol, 2-propanone, hexane, cyclohexane, ethylene glycol, glycerol, etc.), and the dispersions and alignments of the Fe2O3 nanoparticles in these solvents with and without an applied magnetic field were investigated using an optical microscope. The microscope images indicated that inter-molecule hydrogen bonding of the solvents with one OH group (water, ethanol, 1-propanol, and isopropanol) could help to disperse and align the Fe2O3 nanoparticles. The intra-molecular hydrogen bonding causes a dramatic increase in viscosity for fluids with multiple OH groups, such as ethylene glycol (C2H6O2) and glycerol (C3H8O3), and makes the Fe2O3 nanoparticles dispersion and alignment difficult. Adding water to those fluids could lead to significantly reduced viscosity and make the particles disperse and align well. Polarity studies indicated that higher polarity yields better dispersion and alignment of the Fe2O3 nanoparticles. Thermal studies showed that thermal conductivity of nanofluids containing metal oxide particles with hydrogen bonding in solvents is enhanced compared to the theoretically calculated data. Intermolecular hydrogen bonding between water and ethylene glycol increases the thermal conductivity of nanofluids while decreasing the fluid viscosity. The results also well explain why 50 wt. % water/50 wt. % ethylene glycol is an excellent commercial coolant. Since high thermal conductivity enhancement with minimal viscosity increase is the primary goal of heat transfer nanofluids, this current research may open new doors to better understanding of the fundamental nature of nanofluids.

  2. Determination of volatile compounds in wine by gas chromatography-flame ionization detection: comparison between the U.S. Environmental Protection Agency 3sigma approach and Hubaux-Vos calculation of detection limits using ordinary and bivariate least squares.

    PubMed

    Caruso, Rosario; Scordino, Monica; Traulo, Pasqualino; Gagliano, Giacomo

    2012-01-01

    A capillary GC-flame ionization detection (FID) method to determine volatile compounds (ethyl acetate, 1,1-diethoxyethane, methyl alcohol, 1-propanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-butanol, and 2-butanol) in wine was investigated in terms of calculation of detection limits and calibration method. The main objectives were: (1) calculation of regression coefficient parameters by ordinary least-squares (OLS) and bivariate least-squares (BLS) regression models, taking into account errors in both axes; (2) estimation of linear dynamic range (LDR) according to International Conference on Harmonization recommendations; (3) performance evaluation of a method by using three different internal standards (ISs) such as acetonitrile, acetone, and 1-pentanol; (4) evaluation of LODs according to the U.S. Environmental Protection Agency (EPA) 3sigma approach and the Hubaux-Vos (H-V) method; (5) application of H-V theory to a gas chromatographic analytical method and to a food matrix; and (6) accuracy assessment of the method relative to methyl alcohol content through a Unione Italiana Vini (UIV) interlaboratory proficiency test. Calibration curves calculated via BLS and OLS show similar slopes, while intercepts are closer to zero in the first case, independent of the chosen IS. The studied ISs show a substantially equivalent behavior, even though the IS closer to the analyte retention time seems to be more appropriate in terms of LDR and LOD. Results indicate an underestimation of LODs using the EPA 3sigma approach instead of the more realistic H-V method, both with OLS and BLS regression models. Methanol contents compared with UIV average values indicate recovery between 90 and 110%.

  3. Effect of Initial Headspace O2 Level on the Growth and Volatile Metabolite Production of Leuconostoc Mesenteriodes and the Microbial and Sensorial Quality of Modified Atmosphere Packaged Par-Fried French Fries.

    PubMed

    Samapundo, Simbarashe; Mujuru, Felix Mugove; de Baenst, Ilse; Denon, Quenten; Devlieghere, Frank

    2016-02-01

    This study evaluated the effect of residual O2 level (0% to 5%) on microbial growth and volatile metabolite production on par-fried French fries packaged in a modified atmosphere with 60% CO2 (rest N2 ) at 4 °C. The results obtained showed that the initial headspace (IH) O2 level had an effect on growth of Leuconostoc mesenteroides on French fry simulation agar, whereby growth was slightly faster under 5% O2 . In terms of quantity, ethanol, 2-methyl-1-propanol, and dimethyl disulphide were the most significant volatile metabolites produced by L. mesenteroides. The production of ethanol by L. mesenteroides was highest on simulation agar packaged under low IH O2 levels (0% to 1%), indicating that the fermentative metabolism was induced under these conditions. In agreement with the results observed on the simulation medium, growth of native lactic acid bacteria was faster under an IH O2 level of 5%. In addition, ethanol, 2-methyl-1-propanol, and dimethyl disulphide were also quantitatively the most important volatile metabolites. However, in contrast, greater quantities of ethanol and dimethyl disulphide were produced on par-fried French fries packaged under 5% O2 . This was attributed to the limited growth of the native flora on the par-fried French fries under residual O2 levels of 0% and 1%. Although some significant differences (P < 0.05) occurred between the French fries packaged in 0%, 1%, and 5 % residual O2 during storage, all products were considered to be acceptable for consumption. The results of this study can be used to optimize the shelf-life of packaged chill stored potato products.

  4. Evaluating paint-sludge chars for adsorption of selected paint solvents

    SciTech Connect

    Kim, B.R.; Kalis, E.M.; Salmeen, I.T.; Kruse, C.W.; Demir, I.; Rostam-Abadi, M.; Carlson, S.L.

    1996-06-01

    At Ford, a study had been carried out to investigate the technical feasibility of converting paint sludge to activated char and reusing the char in paint spray-booth water to capture paint solvents from spray-booth air. As part of the study, several chars were made from a paint sludge and six dried paints to evaluate their effectiveness as adsorbents by conducting a series of liquid-phase adsorption experiments. Three commonly-used paint solvents and p-nitrophenol were selected as adsorbates. The three paint solvents were toluene, 2-methyl-1-propanol (iso-butanol), and 2-butoxyethanol (butylcellosolve). In this paper, the results of the pyrolysis and adsorption experiments are presented along with practical implications. The primary findings include the following: (1) Black-paint chars showed substantially larger surface area and higher adsorption capacity (based on total weight) than white-paint chars which had high ash contents due to the white pigment, titanium dioxide; (2) the adsorption capacity of the paint-sludge char was between those of black-paint and white-paint chars, and was 5--20% that of a commercial activated carbon; (3) titanium dioxide in white-paint chars did not improve the chars` affinity for hydrophilic compounds such as 2-methyl-1-propanol and 2-butoxyethanol; (4) coal could be added to paint sludge to improve the quality of the resulting char and to reduce ash content; and (5) the pyrolysis of paint sludge could present an attractive opportunity for reusing and recycling a waste product for pollution abatement and as a vehicle component.

  5. Determination of volatile compounds in wine by gas chromatography-flame ionization detection: comparison between the U.S. Environmental Protection Agency 3sigma approach and Hubaux-Vos calculation of detection limits using ordinary and bivariate least squares.

    PubMed

    Caruso, Rosario; Scordino, Monica; Traulo, Pasqualino; Gagliano, Giacomo

    2012-01-01

    A capillary GC-flame ionization detection (FID) method to determine volatile compounds (ethyl acetate, 1,1-diethoxyethane, methyl alcohol, 1-propanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-butanol, and 2-butanol) in wine was investigated in terms of calculation of detection limits and calibration method. The main objectives were: (1) calculation of regression coefficient parameters by ordinary least-squares (OLS) and bivariate least-squares (BLS) regression models, taking into account errors in both axes; (2) estimation of linear dynamic range (LDR) according to International Conference on Harmonization recommendations; (3) performance evaluation of a method by using three different internal standards (ISs) such as acetonitrile, acetone, and 1-pentanol; (4) evaluation of LODs according to the U.S. Environmental Protection Agency (EPA) 3sigma approach and the Hubaux-Vos (H-V) method; (5) application of H-V theory to a gas chromatographic analytical method and to a food matrix; and (6) accuracy assessment of the method relative to methyl alcohol content through a Unione Italiana Vini (UIV) interlaboratory proficiency test. Calibration curves calculated via BLS and OLS show similar slopes, while intercepts are closer to zero in the first case, independent of the chosen IS. The studied ISs show a substantially equivalent behavior, even though the IS closer to the analyte retention time seems to be more appropriate in terms of LDR and LOD. Results indicate an underestimation of LODs using the EPA 3sigma approach instead of the more realistic H-V method, both with OLS and BLS regression models. Methanol contents compared with UIV average values indicate recovery between 90 and 110%. PMID:22649934

  6. Effect of Initial Headspace O2 Level on the Growth and Volatile Metabolite Production of Leuconostoc Mesenteriodes and the Microbial and Sensorial Quality of Modified Atmosphere Packaged Par-Fried French Fries.

    PubMed

    Samapundo, Simbarashe; Mujuru, Felix Mugove; de Baenst, Ilse; Denon, Quenten; Devlieghere, Frank

    2016-02-01

    This study evaluated the effect of residual O2 level (0% to 5%) on microbial growth and volatile metabolite production on par-fried French fries packaged in a modified atmosphere with 60% CO2 (rest N2 ) at 4 °C. The results obtained showed that the initial headspace (IH) O2 level had an effect on growth of Leuconostoc mesenteroides on French fry simulation agar, whereby growth was slightly faster under 5% O2 . In terms of quantity, ethanol, 2-methyl-1-propanol, and dimethyl disulphide were the most significant volatile metabolites produced by L. mesenteroides. The production of ethanol by L. mesenteroides was highest on simulation agar packaged under low IH O2 levels (0% to 1%), indicating that the fermentative metabolism was induced under these conditions. In agreement with the results observed on the simulation medium, growth of native lactic acid bacteria was faster under an IH O2 level of 5%. In addition, ethanol, 2-methyl-1-propanol, and dimethyl disulphide were also quantitatively the most important volatile metabolites. However, in contrast, greater quantities of ethanol and dimethyl disulphide were produced on par-fried French fries packaged under 5% O2 . This was attributed to the limited growth of the native flora on the par-fried French fries under residual O2 levels of 0% and 1%. Although some significant differences (P < 0.05) occurred between the French fries packaged in 0%, 1%, and 5 % residual O2 during storage, all products were considered to be acceptable for consumption. The results of this study can be used to optimize the shelf-life of packaged chill stored potato products. PMID:26784149

  7. Comparing the effects of various fuel alcohols on the natural attenuation of Benzene Plumes using a general substrate interaction model

    NASA Astrophysics Data System (ADS)

    Gomez, Diego E.; Alvarez, Pedro J. J.

    2010-04-01

    The effects of five fuel alcohols (methanol, ethanol, 1-propanol, iso-butanol and n-butanol) on the natural attenuation of benzene were compared using a previously developed numerical model (General Substrate Interaction Module — GSIM) and a probabilistic sensitivity analysis. Simulations with a 30 gal dissolving LNAPL (light non-aqueous phase liquid) source consisting of a range of gasoline blends (10% and 85% v:v alcohol content) suggest that all fuel alcohols can hinder the natural attenuation of benzene, due mainly to accelerated depletion of dissolved oxygen and a decrease in the specific degradation rate for benzene (due to catabolite repression and metabolic flux dilution). Simulations for blends with 10% alcohol, assuming a homogeneous sandy aquifer, inferred maximum benzene plume elongations (relative to a regular gasoline release) of 26% for ethanol, 47% for iso-butanol, 147% for methanol, 188% for 1-propanol, and 265% for n-butanol. The corresponding elongation percentages for blends with 85% alcohol were generally smaller (i.e., 25%, 54%, 135%, 163%, and 181%, respectively), reflecting a lower content of benzene in the simulated release. Benzene plume elongation and longevity were more pronounced in the presence of alcohols that biodegrade slower (e.g., propanol and n-butanol), forming longer and more persistent alcohol plumes. Conversely, ethanol and iso-butanol exhibited the lowest potential to hinder the natural attenuation of benzene, illustrating the significant effect that a small difference in chemical structure (e.g., isomers) can have on biodegradation. Overall, simulations were highly sensitive to site-specific biokinetic coefficients for alcohol degradation, which forewarns against generalizations about the level of impact of specific fuel alcohols on benzene plume dynamics.

  8. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 April--30 June 30 1996

    SciTech Connect

    1996-07-25

    A series of CuMgCeO{sub x} catalysts have been prepared by coprecipitating the corresponding metal nitrates with a mixed solution of potassium carbonate and potassium hydroxide. Kinetic studies of methanol and ethanol coupling reactions on K-Cu/MgO/CeO{sub 2} and MgO/CeO{sub 2} catalysts indicate that Cu enhances the rates of alcohol dehydrogenation. The cross-coupling reactions of acetaldehyde and {sup 13}C-labeled methanol produce singly-labeled propionaldehyde, suggesting that it forms by the condensation of acetaldehyde and a reactive intermediate derived from methanol. Isobutyraldehyde, a precursor to isobutanol, forms via the condensation of propionaldehyde and a reactive C{sub 1} intermediate resulting from methanol. CO{sub 2}, one of the reaction products, poisons both basic and metal sites on Ce-containing CuMgO{sub x} catalysts, resulting in decreases in the rates of both alcohol dehydrogenation (Cu sites) and chain-growth condensation reactions (basic sites). CO{sub 2} inhibits ethanol dehydrogenation on both low-Cu and high-Cu CuMgCeO{sub x} catalysts; however, CO{sub 2} has no effect on the activity of low-Cu Ce-free Cu-MgO{sub x} catalysts, suggesting that the Cu on CuMgCeO{sub x} catalysts is more likely to be oxidized by CO{sub 2} to Cu{sup +} species that can be subsequently stabilized by CeO{sub 2}. CO{sub 2} effects on high-pressure isobutanol synthesis from CO/H{sub 2} have been studied on low- and high-Cu CuMgCeO{sub x} catalysts at 320{degrees}C and 4.5 MPa. CO{sub 2} addition and removal on low- and high-Cu catalysts show similar directional effects on CO conversion. CO conversion is lower at all space velocities in the presence of CO{sub 2}, and removal Of CO{sub 2} from the feed partially recovers CO conversion. CO{sub 2} decreases methanol and isobutanol productivities on both catalysts. Addition of 1-propanol to CO/H{sub 2} feed increases isobutanol production, suggesting that 1-propanol is a precursor to isobutanol.

  9. Alkylresorcinols in selected Polish rye and wheat cereals and whole-grain cereal products.

    PubMed

    Kulawinek, Mariola; Jaromin, Anna; Kozubek, Arkadiusz; Zarnowski, Robert

    2008-08-27

    The alkylresorcinol content and homologue composition in selected Polish rye and wheat cultivars and selected whole-grain cereal products were determined in this study. Cereal grains and whole-grain cereal products were extracted with acetone, whereas bread types were extracted with hot 1-propanol. The average alkylresorcinol content in tested rye (approximately 1100 mg/kg DM) and wheat (approximately 800 mg/kg DM) grains harvested in Poland was within the range previously reported in Swedish and Finnish samples. The total alkylresorcinol content in tested cereal products available on the Polish market varied from very low levels in barley grain-based foods up to 3000 mg/kg DM in wheat bran. The total alkylresorcinol content in 14 bread samples extracted with hot 1-propanol varied from approximately 100 mg/kg DM in whole bread made with honey up to approximately 650 mg/kg DM in whole-rye bread. Calculated ratios of C17:0 to C21:0 homologues, a useful parameter previously used to distinguish between rye and wheat cereals and their derived products, was about 1.2-1.4 in rye products, about 0.2 in wheat products, and varied between 0.2 and 0.6 in cereal-derived products containing a mixture of whole rye and/or wheat. The data set obtained were subsequently compared using cluster and principal component analysis, which allowed the tested cereal products to be classified into two major groups consisting of whole-rye or whole-wheat products, respectively. On the basis of that approach, mixed cereal products containing rye and wheat bran or whole rye and wheat flour were grouped between those two well-defined clusters. Our work not only provides a detailed examination of alkylresorcinols in selected Polish rye and wheat cultivars and selected whole-grain cereal products, but also demonstrates that this type of analysis accompanied by the use of proper statistical algorithms offers an objective way to evaluate the quality of whole-grain rye and/or wheat and their derived

  10. Odorous gaseous emissions as influence by process condition for the forced aeration composting of pig slaughterhouse sludge.

    PubMed

    Blazy, V; de Guardia, A; Benoist, J C; Daumoin, M; Lemasle, M; Wolbert, D; Barrington, S

    2014-07-01

    Compost sustainability requires a better control of its gaseous emissions responsible for several impacts including odours. Indeed, composting odours have stopped the operation of many platforms and prevented the installation of others. Accordingly, present technologies collecting and treating gases emitted from composting are not satisfactory and alternative solutions must be found. Thus, the aim of this paper was to study the influence of composting process conditions on gaseous emissions. Pig slaughterhouse sludge mixed with wood chips was composted under forced aerationin 300 L laboratory reactors. The process conditions studied were: aeration rate of 1.68, 4.03, 6.22, 9.80 and 13.44 L/h/kg of wet sludge; incorporation ratio of 0.55, 0.83 and 1.1 (kg of wet wood chips/kg of wet sludge), and; bulking agent particles size of <10, 10<20 and 20<30 mm. Out-going gases were sampled every 2 days and their composition was analysed using gas chromatography coupled with mass spectrometry (GC-MS). Fifty-nine compounds were identified and quantified. Dividing the cumulated mass production over 30 days of composting, by odour threshold, 9 compounds were identified as main potential odour contributors: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone, 1-propanol-2-methyl, dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide and acetophenone. Five gaseous compounds were correlated with both aeration rate and bulking agent to waste ratio: hydrogen sulphide, trimethylamine, ammonia, 2-pentanone and 1-propanol-2-methyl. However, dropping the aeration rate and increasing the bulking agent to waste ratio reduced gaseous odour emissions by a factor of 5-10, when the required threshold dilution factor ranged from 10(5) to 10(6), to avoid nuisance at peak emission rates. Process influence on emissions of dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide were poorly correlated with both aeration rate and bulking agent to waste ratio as a reaction with

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

    PubMed Central

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

    2015-01-01

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

  12. Cytotoxicity of amino alcohols to rat hepatoma-derived Fa32 cells.

    PubMed

    Scheers, Ellen M; Forsby, Anna; Dierickx, Paul J

    2002-01-01

    Amino alcohols are used as emulsifying agents in dry-cleaning soaps, wax removers, cosmetics, paints and insecticides. The cytotoxicities of 12 amino alcohols, which differed in chain length, position of the amino and alcohol groups, and the presence of an additional phenyl group, were determined by the neutral red uptake inhibition assay with normally cultured, glutathione-depleted or antioxidant-enriched Fa32 rat hepatoma-derived cells. Glutathione depletion and antioxidant enrichment were achieved by including 50(M L-buthionine-S,R-sulphoximine (BSO) or 100(M (-tocopherol acetate (vitamin E) in the culture medium for 24 hours before and during the assay. The cytotoxicity of the amino alcohols observed after treatment for 24 hours was expressed as the concentration of compound needed to induce a 50% reduction in neutral red uptake (NI50). The observed NI50 values ranged from 3mM to 30mM. The individual stereoisomers and a racemic mixture of 1-amino-2-propanol exhibited similar cytotoxicities (with normally cultured Fa32 cells, and vitamin E- and BSO-treated cultures). Similar NI50 values for D-(+)-2-amino-1-propanol, 3-amino-1-propanol and the L-, D- or DL- forms of 1-amino-2-propanol, indicated that the position of the amino group had little influence on the cytotoxicities of the amino alcohols. In contrast, the position of the hydroxyl group appeared to play an important role for the toxicity of the compound, as indicated by the significantly different NI50 values for 4-amino-1-butanol and 4-amino-2-butanol. An additional phenyl group greatly increased the cytotoxicity of 2-amino-1,3-propanediol. For most of the compounds, cytotoxicity increased when GSH was depleted, and decreased when the cells were enriched with vitamin E. This indicated that most of the tested chemicals interact with GSH, either directly or indirectly, by processes which generate oxygen free-radicals. Decreased toxicity was found for most of the chemicals administered to vitamin E

  13. Excess around a central molecule with application to binary mixtures.

    PubMed

    Shulgin, Ivan L; Ruckenstein, Eli

    2008-02-28

    It was shown by us (J. Phys. Chem. B, 2006, 110, 12707) that the excess (deficit) of any species i around a central molecule j in a binary mixture is not provided by c(i)G(ij) (where c(i) is the molar concentration of species i in the mixture and G(ij) are the Kirkwood-Buff integrals) as usually considered and that an additional term, involving a volume V(j) which is inaccessible to molecules of species i because of the presence of the central molecule j, must be included. In this paper, the new expression is applied to various binary mixtures and used to establish a simple criterion for preferential solvation in a binary system. First, it is applied to binary Lennard-Jones fluids. The conventional expression for the excess (deficit) in binary mixtures, c(i)G(ij), provides always deficits around any central molecule in such fluids. In contrast, the new expression provides excess for one species and deficit for the other one. In addition, two kinds of binary mixtures involving weak (argon/krypton) and strong (alcohols/water) intermolecular interactions were considered. Again, the conventional expression for the excess (deficit) in a binary mixture, c(i)G(ij), provides always deficits for any central molecule in the argon/krypton mixture, whereas the new expression provides excess for argon (a somewhat smaller molecule) and deficit for krypton. Three alcohol/water binary mixtures (1-propanol/water, tert-butanol/water and methanol/water) with strong intermolecular interactions were considered and compared with the available experimental information regarding the molecular clustering in solutions. We found (for 1-propanol/water and tert-butanol/water) a large excess of alcohols around a central alcohol molecule and a large excess of water around a central water molecule. For both mixtures the maximum of the calculated excess with respect to the concentration corresponds to the maximum in the cluster size found experimentally, and the range of alcohol concentrations in

  14. Synthesis and Characterization of a Hyperbranched Copolymer

    NASA Astrophysics Data System (ADS)

    Royappa, A. Timothy

    2002-01-01

    This experiment involves the cationic ring-opening copolymerization of glycidol (2,3-epoxy-1-propanol) with propylene oxide and is suitable for undergraduate polymer chemistry or advanced organic synthesis laboratory courses. Students are introduced to hyperbranched polymers and learn how to use a combination of analytical techniques in constructing a coherent picture of polymer structure. The reaction mechanism involves active participation by the hydroxyl functional group (of glycidol) in a cationic polymerization, from which protic species are usually, but not always, excluded. This critical feature, which is responsible for the extensive branching in the polymer, helps students learn the difference between the so-called "active chain end" and "activated monomer" propagation mechanisms. The short, straightforward synthesis, which uses commonly available laboratory equipment and commercially available chemicals, is carried out at room temperature and proceeds in high yield. GC monitoring of the reaction and NMR and FTIR analysis yield information about polymer structure and confirm chain branching. The stable polymer product is checked for solubility and further examined by gel permeation chromatography and differential scanning calorimetry, yielding results consonant with the structural information gained by spectroscopic means.

  15. Characterization of the Enantioselective Properties of the Quinohemoprotein Alcohol Dehydrogenase of Acetobacter pasteurianus LMG 1635. 1. Different Enantiomeric Ratios of Whole Cells and Purified Enzyme in the Kinetic Resolution of Racemic Glycidol.

    PubMed

    Machado, S S; Wandel, U; Jongejan, J A; Straathof, A J; Duine, J A

    1999-01-01

    Resting cells of Acetobacter pasteurianus LMG 1635 (ATCC 12874) show appreciable enantioselectivity (E=16-18) in the oxidative kinetic resolution of racemic 2,3-epoxy-1-propanol, glycidol. Distinctly lower values (E=7-9) are observed for the ferricyanide-coupled oxidation of glycidol by the isolated quinohemoprotein alcohol dehydrogenase, QH-ADH, which is responsible for the enantiospecific oxidation step in whole cells. The accuracy of E-values from conversion experiments could be verified using complementary methods for the measurement of enantiomeric ratios. Effects of pH, detergent, the use of artificial electron acceptors, and the presence of intermediate aldehydes, could be accounted for. Measurements of E-values at successive stages of the purification showed that the drop in enantioselectivity correlates with the separation of QH-ADH from the cytoplasmic membrane. It is argued that the native arrangement of QH-ADH in the membrane-associated complex favors the higher E-values. The consequences of these findings for the use of whole cells versus purified enzymes in biocatalytic kinetic resolutions of chiral alcohols are discussed.

  16. Low-temperature specific heat of structural and orientational glasses of simple alcohols

    NASA Astrophysics Data System (ADS)

    Ramos, M. A.; Talón, C.; Jiménez-Riobóo, R. J.; Vieira, S.

    2003-03-01

    In this work, we review, extend and discuss low-temperature specific-heat experiments, that we have conducted on different molecular (hydrogen-bonded) solids both in crystalline and glassy (either amorphous or orientationally disordered) phases. In particular, we have measured the low-temperature specific heat Cp for a set of simple, well known alcohols: glycerol, propanol and ethanol. For glycerol, we have prepared and measured Cp of both glass and crystal phases down to 0.5 K. The same has been done for propanol, in this case comparing the strikingly different values observed for the two chemical isomers, 1-propanol and 2-propanol. Moreover, ethanol exhibits a very interesting polymorphism presenting three different solid phases at low temperature: a fully ordered (monoclinic) crystal, an orientationally disordered (cubic) crystal or 'orientational glass' and the ordinary structural (amorphous) glass. By measuring and comparing the low-temperature specific heat of the three phases, in the boson peak range 2-10 K as well as in the tunnelling-state range below 1 K, we provide a quantitative confirmation that 'glassy behaviour', either concerning low-temperature properties or the glass-transition phenomenon itself, is not directly related to the lack of long-range crystalline order occurring in amorphous solids.

  17. Comparative study of boson peak in normal and secondary alcohols with terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Yomogida, Yoshiki; Sato, Yuki; Nozaki, Ryusuke; Mishina, Tomobumi; Nakahara, Jun'ichiro

    2010-05-01

    Using terahertz (THz) time-domain spectroscopy, we measured the complex permittivity of some normal (1-propanol, 1-butanol, and 1-pentanol) and secondary alcohols (2-propanol, 2-butanol, and 2-pentanol) in the frequency ranges from 0.2 to 2.5 THz at temperatures from 253 to 323 K. For all the samples, the complex permittivity in the THz region includes the following three components: (i) a high frequency side of dielectric relaxation processes, (ii) a broad mode around 1 THz, and (iii) a low frequency side of an intermolecular vibration mode located above 2.5 THz. The mode around 1 THz is recognized as a boson peak which is related to the local structure of disordered materials. The intensity of the boson peak in secondary alcohols is higher than that in normal alcohols. On the other hand, the number of carbon atoms slightly affects the appearance of the boson peak. These observations indicate that the position of an OH group in a molecule has a profound effect on the local structures in monohydric alcohols.

  18. Thermal Conductivity of Metastable States of Simple Alcohols

    NASA Astrophysics Data System (ADS)

    Krivchikov, A. I.; Korolyuk, O. A.; Sharapova, I. V.; Romantsova, O. O.; Bermejo, F. J.; Cabrillo, C.; Bustinduy, I.; González, M. A.

    The thermal conductivity κ(T) of glassy and supercooled liquid methanol, ethanol and of 1-propanol has been measured under equilibrium vapor pressure in temperature interval from 2 K to 160 K by the steady-state method. The metastable orientationally disordered crystal of ethyl alcohol is found to exhibit a temperature dependence of κ(T) that is remarkably close to that of the fully amorphous solid, especially at low temperatures. In the case of propyl alcohol, our results emphasize the role played by internal molecular degrees of freedom as sources of strong resonant phonon scattering. For all samples here explored, the glass-like behavior of κ(T) is described at the phenomenological level using the model of soft potentials. The thermal transport is then understood in terms of a competition between phonon-assisted and diffusive transport effects. The thermal conductivity κ is thus a sum of two contributions: κ = κI + κII, where κI is the acoustic phonon component dependent on the translational and orientational ordering of molecules, κII — is the phonon diffusion component corresponding to a non — acoustic phonon heat transfer in accordance with the Cahill — Pohl model.

  19. Treating exposure to chemical warfare agents: Implications for health care providers and community emergency planning

    SciTech Connect

    Munro, N.B.; Watson, A.P.; Ambrose, K.R.; Griffin, G.D. )

    1990-11-01

    Current treatment protocols for exposure to nerve and vesicant agents found in the US stockpile of unitary chemical weapons are summarized, and the toxicities of available antidotes are evaluated. The status of the most promising of the new nerve agent antidotes is reviewed. In the US, atropine and pralidoxime compose the only approved antidote regimen for organophosphate nerve agent poisoning. Diazepam may also be used if necessary to control convulsions. To avoid death, administration must occur within minutes of substantial exposure together with immediate decontamination. Continuous observation and repeated administration of antidotes are necessary as symptoms warrant. Available antidotes do not necessarily prevent respiratory failure or incapacitation. The toxicity of the antidotes themselves and the individualized nature of medical care preclude recommending that autoinjectors be distributed to the general public. In addition, precautionary administration of protective drugs to the general population would not be feasible or desirable. No antidote exists for poisoning by the vesicant sulfur mustard (H, HD, HT); effective intervention can only be accomplished by rapid decontamination followed by palliative treatment of symptoms. British anti-Lewisite (BAL) (2,3-dimercapto-1-propanol) is the antidote of choice for treatment of exposure to Lewisite, another potent vesicant. Experimental water-soluble BAL analogues have been developed that are less toxic than BAL. Treatment protocols for each antidote are summarized in tabular form for use by health care providers.

  20. High octane ethers from synthesis gas-derived alcohols. Final technical report, September 25, 1990--December 24, 1993

    SciTech Connect

    Klier, K.; Herman, R.G.

    1994-05-01

    The objective of the research was to develop the methodology for the catalytic synthesis of ethers, primarily methyl isobutyl ether (MIBE) and methyl tertiary butyl ether (MTBE), directly from alcohol mixtures that are rich in methanol and 2-methyl-1-propanol (isobutanol). The overall scheme involves gasification of coal, purification and shifting of the synthesis gas, higher alcohol synthesis, and direct synthesis of ethers. The last stage of the synthesis involves direct coupling of synthesis gas-derived methanol and isobutanol that has been previously demonstrated by us to occur over superacid catalysts to yield MIBE and smaller amounts of MTBE at moderate pressures and a mixture of methanol and isobutene at low pressures. A wide range of organic resin catalysts and inorganic oxide and zeolite catalysts have been investigated for activity and selectivity in directly coupling alcohols, principally methanol and isobutanol, to form ethers and in the dehydration of isobutanol to isobutene in the presence of methanol. All of these catalysts are strong acids, and it was found that the organic and inorganic catalysts operate in different, but overlapping, temperature ranges, i.e. mainly 60--120{degrees}C for the organic resins and 90--175{degrees}C for the inorganic catalysts. For both types of catalysts, the presence of strong acid centers is required for catalytic activity, as was demonstrated by lack of activity of fully K{sup +} ion exchanged Nafion resin and zirconia prior to being sulfated by treatment with sulfuric acid.

  1. Application of an isothermal, three-phase catalytic reactor model to predict unsteady-state fixed-bed performance.

    PubMed

    Yang, Ji; Hand, David W; Hokanson, David R; Crittenden, John C

    2003-01-15

    CatReac, a three-phase catalytic mathematical model, was developed for analysis and optimization of the volatile reactor assembly used in International Space Station water processor. This wet oxidation process is used to remove low molecular weight contaminants such as acetic acid, acetone, ethanol, 1-propanol, 2-propanol, and propionic acid, which are not removed by the other treatment processes. The Langmuir-Hinshelwood (Hinshelwood, C. N. The Kinetics of Chemical Change in Gaseous Systems, 3rd ed.; Oxford: London, 1933; pp 301-347) isothermal adsorption expression was successfully used to describe the reaction kinetics of compounds on the catalyst surface for the compounds mentioned above. Small-column experiments combined with the use of the Arrhenius equation were successfully used to predict the Langmuir-Hinshelwood parameters under different temperatures for a temperature range from 93 to 149 degrees C. Full-scale and small-column experiments were successfully used to validate the model predictions for unsteady-state fixed-bed operations. PMID:12564919

  2. YqhD: a broad-substrate range aldehyde reductase with various applications in production of biorenewable fuels and chemicals.

    PubMed

    Jarboe, Laura R

    2011-01-01

    The Escherichia coli NADPH-dependent aldehyde reductase YqhD has contributed to a variety of metabolic engineering projects for production of biorenewable fuels and chemicals. As a scavenger of toxic aldehydes produced by lipid peroxidation, YqhD has reductase activity for a broad range of short-chain aldehydes, including butyraldehyde, glyceraldehyde, malondialdehyde, isobutyraldehyde, methylglyoxal, propanealdehyde, acrolein, furfural, glyoxal, 3-hydroxypropionaldehyde, glycolaldehyde, acetaldehyde, and acetol. This reductase activity has proven useful for the production of biorenewable fuels and chemicals, such as isobutanol and 1,3- and 1,2-propanediol; additional capability exists for production of 1-butanol, 1-propanol, and allyl alcohol. A drawback of this reductase activity is the diversion of valuable NADPH away from biosynthesis. This YqhD-mediated NADPH depletion provides sufficient burden to contribute to growth inhibition by furfural and 5-hydroxymethyl furfural, inhibitory contaminants of biomass hydrolysate. The structure of YqhD has been characterized, with identification of a Zn atom in the active site. Directed engineering efforts have improved utilization of 3-hydroxypropionaldehyde and NADPH. Most recently, two independent projects have demonstrated regulation of yqhD by YqhC, where YqhC appears to function as an aldehyde sensor.

  3. Increased significance of food wastes: selective recovery of added-value compounds.

    PubMed

    Reis, Igor A O; Santos, Samuel B; Santos, Ludmila A; Oliveira, Naiana; Freire, Mara G; Pereira, Jorge F B; Ventura, Sónia P M; Coutinho, João A P; Soares, Cleide M F; Lima, Álvaro S

    2012-12-15

    A single-step selective separation of two food additives was investigated using alcohol-salt aqueous two-phase systems (ATPS). The selective partitioning of two of the most used additives from a processed food waste material, vanillin and l-ascorbic acid, was successfully accomplished. The results obtained prove that alcohol-salt ATPS can be easily applied as cheaper processes for the selective recovery of valuable chemical products from food wastes and other sources. As a first approach, the phase diagrams of ATPS composed of different alcohol+inorganic salt+water were determined at 298 (± 1)K and atmospheric pressure. The influence of methanol, ethanol, 1-propanol, and 2-propanol and K(3)PO(4), K(2)HPO(4) or KH(2)PO(4)/K(2)HPO(4) in the design of the phase diagrams was addressed. After the evaluation of the phase diagrams behaviour, the influence of the phase forming constituents was assessed towards the partition coefficients and recovery percentages of vanillin and l-ascorbic acid among the coexisting phases. Both model systems and real processed food waste materials were employed. Using these ATPS as partitioning systems it is possible to recover and separate vanillin, which migrates for the alcohol-rich phase, from l-ascorbic acid, which preferentially partitions for the salt-rich phase. PMID:22980828

  4. Study of O/W micro- and nano-emulsions based on propylene glycol diester as a vehicle for geranic acid.

    PubMed

    Jaworska, Małgorzata; Sikora, Elżbieta; Ogonowski, Jan; Konieczna, Monika

    2015-01-01

    Nano- and microemulsions containing as the oil phase caprylic/capric propylene glycol diesters (Crodamol PC) were investigated as potential vehicle for controlled release of geranic acid. The influence of emulsifiers and co-surfactants on stability of the emulsions was investigated. Different kind of polysorbates (ethoxylated esters of sorbitan and fatty acids) were applied as the emulsifiers. The short-chain alcohols (ethanol, 1-propanol, 1-butanol) were used as co-surfactants. The emulsions were prepared at ambient temperature (25°C), by the phase inversion composition method (PIC). The stable O/W high dispersed emulsion systems based on Crodamol PC, of mean droplets size less than 200 nm, were prepared. Microemulsions stabilized by the mixture of Polisorbat 80 and 1-butanol were characterized by the largest degree of dispersion (137 nm) and the lowest PDI value (0.094), at surfactant/co-surfactant: oil weight ratio 90:10. The stable nano-emulsion (mean droplet size of 33 nm) was obtained for surfactant: oil (S:O) weight ratio 90:10, without co-surfactant addition. This nano-emulsion was chosen to release studies. The obtained results showed that the prepared stable nano-emulsion can be used as a carrier for controlled release of geranic acid. The active substance release from the nano-emulsion and the oil solution, after 24 hours was 22%.

  5. Temperature and viscosity dependence of the nonradiative decay rates of auramine-O and thioflavin-T in glass-forming solvents.

    PubMed

    Erez, Yuval; Amdursky, Nadav; Gepshtein, Rinat; Huppert, Dan

    2012-12-13

    Both auramine-O (AuO) and thioflavin-T (ThT) behave as fluorescent molecular rotors, meaning that their (non)radiative properties are markedly affected by the intramolecular rotation of the molecule. In this article, steady-state and time-resolved fluorescence of AuO and ThT were measured in three alcohols, 1-propanol, 1-butanol, and 1-pentanol, over a wide range of temperatures (86-260 K). These solvents are glass-forming liquids, and their viscosity and dielectric relaxation time increase by more than 10 orders of magnitude as the temperature is lowered from room temperature to ~100 K. Accordingly, the fluorescence nonradiative rates constants of AuO and ThT in these solvents decrease by about 3 orders of magnitude at the latter temperature range. We found very good correspondence between the temperature dependence of the nonradiative rate constant, k(nr), of both molecules and the dielectric relaxation rate of the solvents. The k(nr) values of AuO are twice those of ThT along the whole temperature range. The temperature dependence of k(nr) is consistent with the nonradiative model suggested by Glasbeek and co-workers.

  6. Simple cerium-triethanolamine complex: Synthesis, characterization, thermal decomposition and its application to prepare ceria support for platinum catalysts used in methane steam reforming

    NASA Astrophysics Data System (ADS)

    Wattanathana, Worawat; Nootsuwan, Nollapan; Veranitisagul, Chatchai; Koonsaeng, Nattamon; Laosiripojana, Navadol; Laobuthee, Apirat

    2015-06-01

    Cerium-triethanolamine complex was synthesized by simple complexation method in 1-propanol solvent using cerium(III) chloride as a metal source and triethanolamine as a ligand. The structures of the prepared complex were proposed based on FT-IR, FT-Raman and ESI-MS results as equimolar of triethanolamine and cerium chelated complex having monomeric tricyclic structure with and without chloride anion as another coordinating group known as ceratrane. The complex was used as a precursor for ceria material done by thermal decomposition. XRD result revealed that when calcined at 600 °C for 2 h, the cerium complex was totally turned into pure ceria with cubic fluorite structure. The obtained ceria was then employed to synthesize platinum doped ceria catalysts for methane steam reforming. Various amounts of platinum i.e. 1, 3, 5 and 10 mol percents were introduced on the ceria support by microwave-assisted wetness impregnation using ammonium tetrachloroplatinate(II). The platinum-impregnated ceria powders were subjected to calcination in 10% hydrogen/helium atmosphere at 500 °C for 3 h to reduce platinum(II) to platinum(0). XRD patterns of the catalysts confirmed that the platinum particles doped on the ceria support were in the form of platinum(0). Catalytic activity test showed that the catalytic activities got higher as the amounts of platinum doped increased. Besides, the portions of coke formation on the surface of catalysts were reduced as the amounts of platinum doped increased.

  7. Upconversion, size analysis, and fiber filling of NaYF4: Ho3+, Yb3+ crystals and nanocolloids

    NASA Astrophysics Data System (ADS)

    Patel, Darayas; Lewis, Ashley; Wright, Donald; Velentine, Maucus; Lewis, Danielle; Valentine, Ruben; Sarkisov, Sergey

    2014-03-01

    Nano-colloids and nano-crystals doped with ions of rare-earth elements have recently attracted a lot of attention in the scientific community. This attention is due to unique physical, chemical and optical properties attributed to nanometer size of the particles. They have great potential of being used in applications spanning from new types of lasers, especially blue and UV ones, phosphorous display monitors, optical communications, and fluorescence imaging. In this paper we investigate the near-infrared upconversion luminescence in bulk crystals and nanocolloid filled photonic crystal fiber with ytterbium and holmium co-doped NaYF4 phosphor. The phosphor is prepared by using simple co-precipitation synthetic method. The initially prepared phosphor has very week upconversion fluorescence. The fluorescence significantly increased after the phosphor was annealed at a temperature of 600 °C. Nanocolloids of this phosphor were obtained using 1-propanol as solvent and they were utilized as laser filling medium in photonic crystal fibers. Under 980 nm diode laser excitation very strong upconversion signals were obtained for ytterbium and holmium co-doped phosphor at 541 nm, 646 nm and 751 nm. Pump power emissions, laser ablation and size analysis of the particles was conducted to understand the upconversion mechanisms. The particle sizes of the nanocolloids were analyzed using Atomic Force Microscope and Malvern Zetasizer instrument. The reported nanocolloids are good candidates for fluorescent biosensing applications and also as a new laser filling medium in fiber laser.

  8. Lipase-catalysed production of biodiesel fuel from some Nigerian lauric oils.

    PubMed

    Abigor, R D; Uadia, P O; Foglia, T A; Haas, M J; Jones, K C; Okpefa, E; Obibuzor, J U; Bafor, M E

    2000-12-01

    Fatty acids esters were produced from two Nigerian lauric oils, palm kernel oil and coconut oil, by transesterification of the oils with different alcohols using PS30 lipase as a catalyst. In the conversion of palm kernel oil to alkyl esters (biodiesel), ethanol gave the highest conversion of 72%, t-butanol 62%, 1-butanol 42%, n-propanol 42% and iso-propanol 24%, while only 15% methyl ester was observed with methanol. With coconut oil, 1-butanol and iso-butanol achieved 40% conversion, 1-propanol 16% and ethanol 35%, while only traces of methyl esters were observed using methanol. Studies on some fuel properties of palm kernel oil and its biodiesel showed that palm kernel oil had a viscosity of 32.40 mm2/s, a cloud point of 28 degrees C and a pour point of 22 degrees C, while its biodiesel fuel had a viscosity of 9.33 mm2/s, a cloud point of 12 degrees C and a pour point of 8 degrees C. Coconut oil had a viscosity of 28.58 mm(2)/s, a cloud point of 27 degrees C and a pour point of 20 degrees C, while its biodiesel fuel had a viscosity of 7.34 mm2/s, a cloud point of 5 degrees C and a pour point of -8 degrees C. Some of the fuel properties compared favourably with international biodiesel specifications.

  9. Shape-tunable hollow silica nanomaterials based on a soft-templating method and their application as a drug carrier.

    PubMed

    Chen, Jiao; Wu, Xu; Hou, Xiaodong; Su, Xingguang; Chu, Qianli; Fahruddin, Nenny; Zhao, Julia Xiaojun

    2014-12-24

    A one-step soft-templating method for synthesizing shape-tunable hollow silica nanomaterials was developed in a reliable and highly reproducible way. For the first time, both nonspherical and spherical shapes with hollow interiors, including nanowire, nanospheres, and nanotadpole, were successfully obtained by simply changing the solvent. Poly(vinylpyrrolidone) (PVP)-water droplets were used as soft templates for the formation of hollow structures, while three different solvents, including 1-propanol, 1-pentanol, and ethanol, led to the designed shapes. It was found that the solvent, the formation of PVP-water droplets, the amount of ammonia, and the reaction time had great effects on the morphology of synthesized hollow nanomaterials. The effect of various factors on the morphology was systematically studied to propose a growth mechanism. The obtained hollow silica nanomaterials showed excellent reproducibility and great potential for a large-scale synthesis. Finally, the application of the developed hollow silica nanomaterials was demonstrated using the hollow spherical silica nanoparticles. Its drug-carrying ability was studied. The results could be extended for doping various target molecules into the hollow structures for a broad range of applications.

  10. Heterometallic Cu(II)-Dy(III) Clusters of Different Nuclearities with Slow Magnetic Relaxation.

    PubMed

    Modak, Ritwik; Sikdar, Yeasin; Cosquer, Goulven; Chatterjee, Sudipta; Yamashita, Masahiro; Goswami, Sanchita

    2016-01-19

    The synthesis, structures, and magnetic properties of two heterometallic Cu(II)-Dy(III) clusters are reported. The first structural motif displays a pentanuclear Cu(II)4Dy(III) core, while the second one reveals a nonanuclear Cu(II)6Dy(III)3 core. We employed o-vanillin-based Schiff base ligands combining o-vanillin with 3-amino-1-propanol, H2vap, (2-[(3-hydroxy-propylimino)-methyl]-6-methoxy-phenol), and 2-aminoethanol, H2vae, (2-[(3-hydroxy-ethylimino)-methyl]-6-methoxy-phenol). The differing nuclearities of the two clusters stem from the choice of imino alcohol arm in the Schiff bases, H2vap and H2vae. This work is aimed at broadening the diversity of Cu(II)-Dy(III) clusters and to perceive the consequence of changing the length of the alcohol arm on the nuclearity of the cluster, providing valuable insight into promising future synthetic directions. The underlying topological entity of the pentanuclear Cu4Dy cluster is reported for the first time. The investigation of magnetic behaviors of 1 and 2 below 2 K reveals slow magnetic relaxation with a significant influence coming from the variation of the alcohol arm affecting the nature of magnetic interactions. PMID:26702645

  11. Ternary DNA chip based on a novel thymine spacer group chemistry.

    PubMed

    Yang, Yanli; Yildiz, Umit Hakan; Peh, Jaime; Liedberg, Bo

    2015-01-01

    A novel thymine-based surface chemistry suitable for label-free electrochemical DNA detection is described. It involves a simple two-step sequential process: immobilization of 9-mer thymine-terminated probe DNAs followed by backfilling with 9-mer thymine-based spacers (T9). As compared to commonly used organic spacer groups like 2-mercaptoethanol, 3-mercapto-1-propanol and 6-mercapto-1-hexanol, the 9-mer thymine-based spacers offer a 10-fold improvement in discriminating between complementary and non-complementary target hybridization, which is due mainly to facilitated transport of the redox probes through the probe-DNA/T9 layers. Electrochemical measurements, complemented with Surface Plasmon Resonance (SPR) and Quartz Crystal Microbalance (QCM-D) binding analyses, reveal that optimum selectivity between complementary and non-complementary hybridization is obtained for a sensing surface prepared using probe-DNA and backfiller T9 at equimolar concentration (1:1). At this particular ratio, the probe-DNAs are preferentially oriented and easily accessible to yield a sensing surface with favorable hybridization and electron transfer characteristics. Our findings suggest that oligonucleotide-based spacer groups offer an attractive alternative to short organic thiol spacers in the design of future DNA biochips. PMID:25465760

  12. Graphene oxide membrane for liquid phase organic molecular separation

    NASA Astrophysics Data System (ADS)

    Liu, Renlong; Arabale, Girish; Kim, Jinseon; Sun, Ke; Lee, Yongwoon; Ryu, Changkook; Lee, Changgu

    2015-03-01

    The selective permeation of organic solvents and water through graphene oxide (GO) membranes has been demonstrated. Water was found to permeate through GO membranes faster than various alcohols. The permeation rates of propanol are about 80 times lower than that of water. Taking advantage of the differences in the permeation rates, we separated water from the alcohols and obtained alcohols with high purity. For ethanol and 1-propanol, binary solutions of the alcohol and water were filtered efficiently to produce alcohols with concentration of about 97%. However, the selectivity of the filtration of methanol is significantly lower than those of the other alcohols. To understand the mechanism we followed the structural changes in the GO membranes by X-Ray diffraction analysis. From the X-ray diffraction results we speculate that the selectivity of the permeation of water and alcohols is closely related to the molecular sizes of the solvents and their polarity. In order to demonstrate the potential applications of this process for the selective removal of water from aqueous organic mixtures, we performed the separation of water from a bio-oil containing 73% of water. The majority of the water was filtered out resulting in a higher purity bio-oil.

  13. Characterization of kinetic parameters and the formation of volatile compounds during the tequila fermentation by wild yeasts isolated from agave juice.

    PubMed

    Arellano, Melchor; Pelayo, Carlos; Ramírez, Jesús; Rodriguez, Ingrid

    2008-08-01

    The production of aroma compounds during tequila fermentation using four native yeast strains isolated from agave juice was quantified at controlled (35 degrees C) and uncontrolled temperatures (room temperature) by gas chromatography (FID). Three of the four strains were identified as Saccharomyces cerevisiae (MTLI 1, MALI 1 and MGLI 1) and one as Kloeckera apiculata (MALI 2). Among the aroma compounds produced, acetaldehyde has the highest accumulation at the controlled temperature and before 50% of sugar was consumed. The S. cerevisiae strains produced ethyl acetate in almost the same quantity at a concentration of 5 mg/L and the K. apiculata produced six-times more (30 mg/L) than the S. cerevisiae strains, independent of the fermentation temperature. The rate and amount of 1-propanol, amyl alcohols and isobutanol production were affected by the type of yeast used. The K. apiculate strain produced 50% less of the higher alcohols than the Saccharomyces strains. The results obtained showed that indigenous isolated yeasts play an important role in the tequila flavor and suggest that mixtures of these yeasts may be used to produce tequila with a unique and desirable aroma.

  14. Production of fermentation aroma compounds by Saccharomyces cerevisiae wine yeasts: effects of yeast assimilable nitrogen on two model strains.

    PubMed

    Carrau, Francisco M; Medina, Karina; Farina, Laura; Boido, Eduardo; Henschke, Paul A; Dellacassa, Eduardo

    2008-11-01

    The contribution of yeast fermentation metabolites to the aromatic profile of wine is well documented; however, the biotechnological application of this knowledge, apart from strain selection, is still rather limited and often contradictory. Understanding and modeling the relationship between nutrient availability and the production of desirable aroma compounds by different strains must be one of the main objectives in the selection of industrial yeasts for the beverage and food industry. In order to overcome the variability in the composition of grape juices, we have used a chemically defined model medium for studying yeast physiological behavior and metabolite production in response to nitrogen supplementation so as to identify an appropriate yeast assimilable nitrogen level for strain differentiation. At low initial nitrogen concentrations, strain KU1 produced higher quantities of esters and fatty acids whereas M522 produced higher concentrations of isoacids, gamma-butyrolactone, higher alcohols and 3-methylthio-1-propanol. We propose that although strains KU1 and M522 have a similar nitrogen consumption profile, they represent useful models for the chemical characterization of wine strains in relation to wine quality. The differential production of aroma compounds by the two strains is discussed in relation to their capacity for nitrogen usage and their impact on winemaking. The results obtained here will help to develop targeted metabolic footprinting methods for the discrimination of industrial yeasts.

  15. Conversion of Methanol, Ethanol and Propanol over Zeolites

    SciTech Connect

    Ramasamy, Karthikeyan K.; Wang, Yong

    2013-06-04

    Renewable fuel from lignocellulosic biomass has recently attracted more attention due to its environmental and the potential economic benefits over the crude oil [1]. In particular the production of fuel range hydrocarbon (HC) from alcohol generated lots of interest since the alcohol can be produced from biomass via thermochemical [2] (mixed alcohol from gasification derived synthesis gas) as well as the biochemical routes [3] (alcohol fermentation). Along with the development of ZSM5 synthesis and the discovery of methanol-to-gasoline (MTG) process by Mobil in 1970’s triggered lots of interest in research and development arena to understand the reaction mechanisms of alcohols over zeolites in particular ZSM5 [4]. More detailed research on methanol conversion was extensively reported [5] and in recent times the research work can be found on ethanol [6] and other alcohols as well but comprehensive comparison of catalyst activity and the deactivation mechanism of the conversion of various alcohols over zeolites has not been reported. The experiments were conducted on smaller alcohols such as methanol, ethanol and 1-propanol over HZSM5. The experimental results on the catalyst activity and the catalyst deactivation mechanism will be discussed.

  16. Comparative studies on the alcohol types presence in Gracilaria sp. and rice fermentation using Sasad

    NASA Astrophysics Data System (ADS)

    Mansa, R.; Mansuit, H.; Sipaut, C. S.; Yee, C. F.; Yasir, S. M.

    2016-06-01

    Alternative fuel sources such as biofuels are needed in order to overcome environmental problem caused by fossil fuel consumption. Currently, most biofuel are produced from land based crops and there is a possibility that marine biomass such as macroalgae can be an alternative source for biofuel production. The carbohydrate in macroalgae can be broken down into simple sugar through thermo-chemical hydrolysis and enzymatic hydrolysis. Dilute-acid hydrolysis was believed to be the most available and affordable method. However, the process may release inhibitors which would affect alcohol yield from fermentation. Thus, this work was aimed at investigating if it is possible to avoid this critical pre-treatment step in macroalgae fermentation process by using Sasad, a local Sabahan fermentation agent and to compare the yield with rice wine fermentation. This work hoped to determine and compare the alcohol content from Gracilaria sp. and rice fermentation with Sasad. Rice fermentation was found containing ethanol and 2 - methyl - 1 - propanol. Fermentation of Gracilaria sp. had shown the positive presence of 3 - methyl - 1 - butanol. It was found that Sasad can be used as a fermentation agent for bioalcohol production from Gracilaria sp. without the need for a pretreatment step. However further investigations are needed to determine if pre-treatment would increase the yield of alcohol.

  17. Development and validation of a stability-indicating micellar liquid chromatographic method for the determination of timolol maleate in the presence of its degradation products.

    PubMed

    Rizk, Mohamed S; Merey, Hanan A; Tawakkol, Shereen M; Sweilam, Mona N

    2015-04-01

    A stability-indicating micellar liquid chromatographic (MLC) method was developed and validated for the quantitative determination of timolol maleate (TM) in the presence of its degradation products resulting from accelerated degradation in a run time not more than 8 min. TM was subjected to stress conditions of hydrolysis (including alkaline, acidic and thermal hydrolysis) and oxidation. An isocratic, rapid and mobile phase saving the micellar LC method was developed with a BioBasic phenyl column (150 × 1.0 mm, 5 µm particle size) and a micellar mobile phase composed of 0.1 M sodium dodecyl sulfate, 10% of 1-propanol and 0.1% of triethylamine in 0.035 M ortho-phosphoric acid. The flow rate of the mobile phase was 0.1 mL/min. UV detection was adjusted at 298 nm and performed at room temperature. The method has been validated according to the International Conference on Harmonisation guidelines. The method is successfully applied for the determination of TM in bulk powder and pharmaceutical dosage form.

  18. Glycosphingolipid synthesis inhibitor represses cytokine-induced activation of the Ras-MAPK pathway in embryonic neural precursor cells.

    PubMed

    Yanagisawa, Makoto; Nakamura, Kazuo; Taga, Tetsuya

    2005-09-01

    Neuronal and glial cells in the central nervous system are generated from common neural precursor cells during development. To evaluate the functions of glycosphingolipids (GSLs) in neural precursor cells, neuroepithelial cells (NECs) were prepared from mouse embryos (E14.5), and the effects of an inhibitor of glucosylceramide synthesis, D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP), on NECs was investigated. In PDMP-treated NECs, the expression of GD3, a major ganglioside of NECs, disappeared. We found that basic fibroblast growth factor (bFGF)-induced proliferation and extracellular signal-regulated kinase (ERK) activation were repressed in PDMP-treated NECs. Leukemia inhibitory factor (LIF)-induced ERK activation was also abolished in PDMP-treated NECs, suggesting that PDMP specifically represses the Ras-MAPK pathway. bFGF-induced activation of the Ras-MAPK pathway in NECs is dependent on GSL-enriched microdomains, lipid rafts. The organization of lipid rafts and the distribution of Ras and Grb2-SOS in the microdomains were not affected. However, Ras activation was repressed in PDMP-treated NECs. In PDMP-treated NECs, some neuronal genes were up-regulated and glial genes were down-regulated. These results suggest that GSLs might be involved in the proliferation, survival, signal transduction and differentiation of NECs.

  19. Fungal volatiles as indicators of food and feeds spoilage.

    PubMed

    Schnürer, J; Olsson, J; Börjesson, T

    1999-01-01

    Fungal growth leads to spoilage of food and animal feeds and to formation of mycotoxins and potentially allergenic spores. Fungi produce volatile compounds, during both primary and secondary metabolism, which can be used for detection and identification. Fungal volatiles from mainly Aspergillus, Fusarium, and Penicillium have been characterized with gas chromatography, mass spectrometry, and sensory analysis. Common volatiles are 2-methyl-1-propanol, 3-methyl-1-butanol, 1-octen-3-ol, 3-octanone, 3-methylfuran, ethyl acetate, and the malodorous 2-methyl-isoborneol and geosmin. Volatile sesquiterpenes can be used for taxonomic classification and species identification in Penicillium, as well as to indicate mycotoxin formation in Fusarium and Aspergillus. Developments in sensor technology have led to the construction of "electronic noses" (volatile compound mappers). Exposure of different nonspecific sensors to volatile compounds produces characteristic electrical signals. These are collected by a computer and processed by multivariate statistical methods or in an artificial neural network (ANN). Such systems can grade cereal grain with regard to presence of molds as efficiently as sensory panels evaluating grain odor. Volatile compound mapping can also be used to predict levels of ergosterol and fungal colony-forming units in grain. Further developments should make it possible to detect individual fungal species as well as the degree of mycotoxin contamination of food and animal feeds.

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

    NASA Astrophysics Data System (ADS)

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

    2005-06-01

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

  1. A microfluidic device for open loop stripping of volatile organic compounds.

    PubMed

    Cvetković, Benjamin Z; Dittrich, Petra S

    2013-03-01

    The detection of volatile organic compounds is of great importance for assessing the quality of water. In this contribution, we describe a miniaturized stripping device that allows fast online detection of organic solvents in water. The core component is a glass microfluidic chip that facilitates the creation of an annular-flowing stream of water and nitrogen gas. Volatile compounds are transferred efficiently from the water into the gas phase along the microfluidic pathway at room temperature within less than 5 s. Before exiting the microchip, the liquid phase is separated from the enriched gas phase by incorporating side capillaries through which the hydrophilic water phase is withdrawn. The gas phase is conveniently collected at the outlet reservoir by tubing. Finally, a semiconductor gas sensor analyzes the concentration of (volatile) organic compounds in the nitrogen gas. The operation and use of the stripping device is demonstrated for the organic solvents THF, 1-propanol, toluene, ethylbenzene, benzaldehyde, and methanol. The mobile, inexpensive, and continuously operating system with liquid flow rates in the low range of microliters per minute can be connected to other detectors or implemented in chemical production line for process control.

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

    PubMed

    Li, Jing; Zhu, Yan

    2014-01-01

    This paper describes a novel analytical system for non-suppressed capillary ion chromatography. Methacrylate monolithic columns were prepared from silanized fused-silica capillaries of 320 µm i.d. by in situ polymerization of glycidyl methacrylate and ethylene dimethacrylate in the presence of 1,4-butanediol, 1-propanol and water as the porogen solvents. The introduction of cation-exchange sites was achieved by sulfonating the matrix with sodium sulfite to produce total cation-exchange capacities in the range of 45-105 μequiv/mL for a 25 cm column. The conditions (concentrations of sodium sulfite solution, reacting time and modified flow rate) of sulfonation were optimized. The hydrodynamic and chromatographic performances were estimated. Coupled with a conductivity detector, a capillary ion chromatography system was set up with the prepared column. Finally, the resultant column was used for the separations of five common univalent cations (Li(+), Na(+), NH4(+), K(+) and Cs(+)) using methanesulfonic acid as the eluent and four divalent cations (Mg(2+), Ca(2+), Sr(2+) and Ba(2+)) by non-suppressed capillary ion chromatography; the chromatographic parameters were further researched. PMID:23677716

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

    PubMed

    Li, Jing; Zhu, Yan

    2014-01-01

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

  4. Phase behavior and second osmotic virial coefficient for competitive polymer solvation in mixed solvent solutions.

    PubMed

    Dudowicz, Jacek; Freed, Karl F; Douglas, Jack F

    2015-11-21

    We apply our recently developed generalized Flory-Huggins (FH) type theory for the competitive solvation of polymers by two mixed solvents to explain general trends in the variation of phase boundaries and solvent quality (quantified by the second osmotic virial coefficient B2) with solvent composition. The complexity of the theoretically predicted miscibility patterns for these ternary mixtures arises from the competitive association between the polymer and the solvents and from the interplay of these associative interactions with the weak van der Waals interactions between all components of the mixture. The main focus here lies in determining the influence of the free energy parameters for polymer-solvent association (solvation) and the effective FH interaction parameters {χαβ} (driving phase separation) on the phase boundaries (specifically the spinodals), the second osmotic virial coefficient B2, and the relation between the positions of the spinodal curves and the theta temperatures at which B2 vanishes. Our classification of the predicted miscibility patterns is relevant to numerous applications of ternary polymer solutions in industrial formulations and the use of mixed solvent systems for polymer characterization, such as chromatographic separation where mixed solvents are commonly employed. A favorable comparison of B2 with experimental data for poly(methyl methacrylate)/acetonitrile/methanol (or 1-propanol) solutions only partially supports the validity of our theoretical predictions due to the lack of enough experimental data and the neglect of the self and mutual association of the solvents.

  5. A unique enzyme of acetic acid bacteria, PQQ-dependent alcohol dehydrogenase, is also present in Frateuria aurantia.

    PubMed

    Trček, Janja; Matsushita, Kazunobu

    2013-08-01

    A membrane-bound, pyrroloquinoline quinone (PQQ)-dependent alcohol dehydrogenase (ADH) was purified from Frateuria aurantia LMG 1558(T). Although F. aurantia belongs to a group of γ-Proteobacteria, the characteristics of its PQQ-ADH were similar to the enzyme characteristics of the typical high-acetic acid-resistant bacterium Gluconacetobacter europaeus from the group of α-Proteobacteria. The PQQ-dependent ADH was solubilized from the membranes and purified after anionic, cationic, and affinity chromatography with specific activity of 117 U/mg. The purified enzyme was estimated to be composed of two subunits of ca. 72 and 45 kDa, as judged by SDS-polyacrylamide gel electrophoresis. The purified enzyme had maximum activity at pH 4.5 and showed the highest substrate specificity to ethanol, isoamyl alcohol, 1-butanol, and 1-propanol. The deduced sequences of cloned genes adhA and adhB encoding subunits I and II of PQQ-ADH showed 80 % amino acid (AA) identity to AdhA and 68 % AA identity to AdhB of Ga. europaeus V3 (LMG 18494). Because of the high similarity between genes encoding subunits I and II of PQQ-ADH and its homologous genes found in a distantly related taxonomic group of acetic acid bacteria, the results suggest the possibility of horizontal gene transfer between these two groups of genera.

  6. Use of micellar liquid chromatography to analyze oxolinic acid, flumequine, marbofloxacin and enrofloxacin in honey and validation according to the 2002/657/EC decision.

    PubMed

    Tayeb-Cherif, K; Peris-Vicente, J; Carda-Broch, S; Esteve-Romero, J

    2016-07-01

    A micellar liquid chromatographic method was developed for the analysis of oxolinic acid, flumequine, marbofloxacin and enrofloxacin in honey. These quinolines are unethically used in beekeeping, and a zero-tolerance policy to antibiotic residues in honey has been stated by the European Union. The sample pretreatment was a 1:1 dilution with a 0.05M SDS at pH 3 solution, filtration and direct injection, thus avoiding extraction steps. The quinolones were eluted without interferences using mobile phase of 0.05M SDS/12.5% 1-propanol/0.5% triethylamine at pH 3, running at 1mL/min under isocratic room through a C18 column. The analytes were detected by fluorescence. The method was successfully validated according to the requirements of the European Union Decision 2002/657/EC in terms of: specificity, linearity (r(2)>0.995), limit of detection and decision limit (0.008-0.070mg/kg), lower limit of quantification (0.02-0.2mg/kg), detection capability (0.010-0.10mg/kg), recovery (82.1-110.0%), precision (<9.4%), matrix effects, robustness (<10.4%), and stability. The procedure was applied to several commercial honey supplied by a local supermarket, and the studied antibiotics were not detected. Therefore, the method was rapid, simple, safe, eco friendly, reliable and useful for the routine analysis of honey samples. PMID:26920300

  7. Physicochemical and Microbial Properties of the Korean Traditional Rice Wine, Makgeolli, Supplemented with Banana during Fermentation.

    PubMed

    Kim, Eunkyung; Chang, Yoon Hyuk; Ko, Jae Youn; Jeong, Yoonhwa

    2013-09-01

    The objective of the present study was to evaluate the physicochemical and microbial properties of the Korean traditional rice wine Makgeolli, supplemented with banana during 6 day fermentation. The alcohol contents of the control and banana Makgeolli were 17.0 and 16.5%, respectively. The pH values decreased while total acidity, total soluble solids, and color values increased throughout the fermentation process. An increase in microorganism counts throughout the 6-day fermentation period was noted in all samples. The major free sugar and organic acid detected in all samples were glucose and succinic acid, respectively. There were 39 volatile compounds detected in the control and banana Makgeolli. The major ester detected was ethyl acetate (20.037 and 22.604% for the control and banana Makgeolli, respectively). The major alcohol compounds detected were 3-methylbutanol (20.933%) and 3-methyl-1-butanol (34.325%) in the control. 2-mtehyl-1-propanol (22.289%) and 3-methyl-1-butanol (39.851%) were the highest alcohol compounds detected in the banana Makgeolli.

  8. Fluorescent-Protein Stabilization and High-Resolution Imaging of Cleared, Intact Mouse Brains

    PubMed Central

    Schwarz, Martin K.; Scherbarth, Annemarie; Sprengel, Rolf; Engelhardt, Johann; Theer, Patrick; Giese, Guenter

    2015-01-01

    In order to observe and quantify long-range neuronal connections in intact mouse brain by light microscopy, it is first necessary to clear the brain, thus suppressing refractive-index variations. Here we describe a method that clears the brain and preserves the signal from proteinaceous fluorophores using a pH-adjusted non-aqueous index-matching medium. Successful clearing is enabled through the use of either 1-propanol or tert-butanol during dehydration whilst maintaining a basic pH. We show that high-resolution fluorescence imaging of entire, structurally intact juvenile and adult mouse brains is possible at subcellular resolution, even following many months in clearing solution. We also show that axonal long-range projections that are EGFP-labelled by modified Rabies virus can be imaged throughout the brain using a purpose-built light-sheet fluorescence microscope. To demonstrate the viability of the technique, we determined a detailed map of the monosynaptic projections onto a target cell population in the lateral entorhinal cortex. This example demonstrates that our method permits the quantification of whole-brain connectivity patterns at the subcellular level in the uncut brain. PMID:25993380

  9. Application of integrated comprehensive/multidimensional gas chromatography with mass spectrometry and olfactometry for aroma analysis in wine and coffee.

    PubMed

    Chin, Sung-Tong; Eyres, Graham T; Marriott, Philip J

    2015-10-15

    Component coelution in chromatographic analysis complicates identification and attribution of individual odour-active volatile molecules in complex multi-component samples. An integrated system incorporating comprehensive two-dimensional gas chromatography (GC × GC) and multidimensional gas chromatography (MDGC), with flame ionisation, olfactometry and mass spectrometry detection was developed to circumvent data correlation across different systems. Identification of potent odorants in Shiraz wine and the headspace of ground coffee are demonstrated as selected applications. Multiple solid-phase microextraction (SPME) sampling with GC-O located odour-active regions; GC × GC established the complexity of odour-active regions; MDGC provided high-resolution separation for each region; simultaneous 'O' and MS detection completed the analysis for target resolved peaks. Seven odour regions in Shiraz were analysed with MDGC-O/MS detection, revealing 11 odour volatiles through matching of mass spectrometry and retention indices from both separating dimensions, including acetic acid; octen-3-ol; ethyl octanoate; methyl-2-oxo-nonanoate; butanoic acid, 2-methylbutanoic acid, and 3-methylbutanoic acid; 3-(methylthio)-1-propanol; hexanoic acid; β-damascenone; and ethyl-3-phenylpropanoate. A capsicum odour in ground coffee was identified as 2-methoxy-3-isobutylpyrazine with a 5-fold increase in S/N of the odorant when acquired using a 6-time cumulative SPME sampling approach.

  10. Protease activation in glycerol-based deep eutectic solvents

    PubMed Central

    Zhao, Hua; Baker, Gary A.; Holmes, Shaletha

    2011-01-01

    Deep eutectic solvents (DESs) consisting of mixtures of a choline salt (chloride or acetate form) and glycerol are prepared as easily accessible, biodegradable, and inexpensive alternatives to conventional aprotic cation-anion paired ionic liquids. These DES systems display excellent fluidity coupled with thermal stability to nearly 200 °C. In this work, the transesterification activities of cross-linked proteases (subtilisin and α-chymotrypsin), immobilized on chitosan, were individually examined in these novel DESs. In the 1:2 molar ratio mixture of choline chloride/glycerol containing 3% (v/v) water, cross-linked subtilisin exhibited an excellent activity (2.9 μmo l min−1 g−1) in conjunction with a selectivity of 98% in the transesterification reaction of N-acetyl-L-phenylalanine ethyl ester with 1-propanol. These highly encouraging results advocate more extensive exploration of DESs in protease-mediated biotransformations of additional polar substrates and use of DESs in biocatalysis more generally. PMID:21909232

  11. Lipid substrate specificity of phosphatidylethanolamine N-methyltransferase of Tetrahymena

    SciTech Connect

    Smith, J.D.

    1986-05-01

    The ciliate protozoan Tetrahymena thermophila forms about 60% of its phosphatidylcholine by methylation of phosphatidylethanolamine with S-adenosylmethionine using the enzyme phosphatidylethanolamine N-methyltransferase. Analogues of ethanolamine or of ethanolamine phosphate are incorporated into the phospholipids of Tetrahymena when cells are cultured in their presence. These compounds, 3-amino-1-propanol, 2-aminoethylphosphonate, 3-aminopropylphosphonate and N,N-dimethylaminoethylphosphonate replace from 50 to 75% of the ethanolamine phosphate in phosphatidylethanolamine. However, analysis of the phospholipids of lipid-altered Tetrahymena showed that none of the phosphatidylethanolamine analogues had been converted to the corresponding phosphatidylcholine analogue. No incorration of (/sup 14/C-CH/sub 3/)methionine into the phosphatidylcholine analogues could be demonstrated in vivo, nor was label from (/sup 3/H-CH/sub 3/)S-adenosylmethionine incorporated in virto. Thus, only phosphatidylethanolamine and its monomethyl and dimethyl derivatives have been found to be substrates for the phosphatidylethanoiamine N-methyltransferase. The enzyme therefore requires a phospholipid substrate containing an ester linkage between the alkylamine and phosphorus, with the amino group required to be ..beta.. to the alcohol.

  12. Correlation of Chemical and Physical Test Data for the Environmental Ageing of Tefzel (ETFE). Revised

    NASA Technical Reports Server (NTRS)

    Morgan, G. J.; Campion, R. P.

    1997-01-01

    In a similar approach to that used for the previously issued correlation report for Coflon (CAPP/M.10), this report aims to identify any correlations between mechanical property changes and chemical/morphological changes for Tefzel, using information supplied in other MERL and TRI project reports. Differences identified with Coflon behaviour will be of scientific interest as well as appropriate to project applications, as Tefzel and Coflon are chemical isomers. Owing to the considerable chemical resistance of Tefzel, much of its testing so far has been based on mechanical properties. Where changes have occurred, chemical analysis can now be targeted more effectively. Relevant test data collated here include: tensile modulus and related properties, permeation coefficients, % crystallinity, some crack growth resistance measurements, and other observations where significant. Fluids based on methanol and amine (Fluid G), a mixture of methane, carbon dioxide and hydrogen sulphide gases plus an aqueous amine solution (Fluid F), and an aromatic oil mix of heptane, cyclohexane, toluene and 1-propanol (Fluid I) have affected Tefzel to varying degrees, and are discussed in some detail herein.

  13. Extraction and purification of anthraquinones derivatives from Aloe vera L. using alcohol/salt aqueous two-phase system.

    PubMed

    Tan, Zhi-jian; Li, Fen-fang; Xu, Xue-lei

    2013-08-01

    An alcohol/salt aqueous two-phase system (ATPS) composed of 1-propanol and (NH4)2SO4 was employed to purify anthraquinones (AQs) extracted from Aloe vera L. The main influencing system parameters such as type of alcohol, type and concentration of salt, temperature and pH were investigated in detail. Under the optimal extraction conditions, AQs can be extracted into alcohol-rich phase with high extraction efficiency, meanwhile majority polysaccharides, proteins, mineral substances and other impurities were extracted into salt-rich phase. Partitioning of AQs is dependent on hydrophobic interaction, hydrogen bond interaction, and salting-out effect in ATPS. Temperature also played a great role in the partitioning. After ATPS extraction, alcohol can be recycled by evaporation; moreover, salt can be recycled by dilution crystallization method. Compared with other liquid-liquid extractions, this alcohol/salt system is much simpler, lower in cost with easier recovery of phase-forming components, which has the potential scale-up in down-processing of active ingredients in plant.

  14. Physico-chemical and microbiological characterization of spontaneous fermentation of Cellina di Nardò and Leccino table olives.

    PubMed

    Bleve, Gianluca; Tufariello, Maria; Durante, Miriana; Perbellini, Ezio; Ramires, Francesca A; Grieco, Francesco; Cappello, Maria S; De Domenico, Stefania; Mita, Giovanni; Tasioula-Margari, Maria; Logrieco, Antonio F

    2014-01-01

    Table olives are one of the most important traditional fermented vegetables in Europe and their world consumption is constantly increasing. In the Greek style, table olives are obtained by spontaneous fermentations, without any chemical debittering treatment. Evolution of sugars, organic acids, alcohols, mono, and polyphenol compounds and volatile compounds associated with the fermentative metabolism of yeasts and bacteria throughout the natural fermentation process of the two Italian olive cultivars Cellina di Nardò and Leccino were determined. A protocol was developed and applied aimed at the technological characterization of lactic acid bacteria (LAB) and yeast strains as possible candidate autochthonous starters for table olive fermentation from Cellina di Nardò and Leccino cultivars. The study of the main physic-chemical parameters and volatile compounds during fermentation helped to determine chemical descriptors that may be suitable for monitoring olive fermentation. In both the analyzed table olive cultivars, aldehydes proved to be closely related to the first stage of fermentation (30 days), while higher alcohols (2-methyl-1-propanol; 3-methyl-1-butanol), styrene, and o-cymene were associated with the middle stage of fermentation (90 days) and acetate esters with the final step of olive fermentation (180 days). PMID:25389422

  15. Phenyl- vs cyclohexyl-substitution in methanol: implications for the OH conformation and for dispersion-affected aggregation from vibrational spectra in supersonic jets.

    PubMed

    Altnöder, Jonas; Oswald, Sönke; Suhm, Martin A

    2014-05-01

    The monomers and hydrogen-bonded dimers of benzyl alcohol, cyclohexylmethanol, and 2-methyl-1-propanol are investigated by jet-FTIR spectroscopy, complemented by Raman spectra and quantum chemical calulations, including CCSD(T) corrections. A large variety of London dispersion effects from the interacting carbon cycles is revealed, sometimes adding to and sometimes competing with the alcoholic hydrogen bonds. Conformational (in-)flexibility provides the key for understanding these effects, and this requires accurate predictions of monomer conformational preferences, which are shown to be subtly at variance with experiment even for some triple-ζ MP2 calculations. In some observed dimers, cooperative OH···OH···π patterns are sacrificed to optimize σ-π dispersion interactions. In other competitive dimers, dispersion interactions are far from maximized, because that would imply a substantial weakening of the hydrogen bond. In the series from methanol dimer to 1-indanol dimer, which this contribution bridges, B3LYP-D3 appears to switch from an overestimation to a slight underestimation of cohesion, but overall it provides a very useful modeling tool for vibrational spectra of systems affected by both hydrogen bonds and London dispersion.

  16. Polypeptide-based aerosol nanoparticles: self-assembly and control of conformation by solvent and thermal annealing.

    PubMed

    Rahikkala, Antti; Junnila, Susanna; Vartiainen, Ville; Ruokolainen, Janne; Ikkala, Olli; Kauppinen, Esko; Raula, Janne

    2014-07-14

    Nanoconfined self-assemblies within aerosol nanoparticles and control of the secondary structures are shown here upon ionically complexing poly(L-lysine) (PLL) with dodecylbenzenesulfonic acid (DBSA) surfactant and using solvents chloroform, 1-propanol, or dimethylformamide. Different solvent volatilities and drying temperatures allowed tuning the kinetics of morphology formation. The supramolecular self-assembly and morphology were studied using cryo-TEM and SEM, and the secondary structures, using FT-IR. Highly volatile chloroform led to the major fraction of α-helical conformation of PLL(DBSA), whereas less volatile solvents or higher drying temperatures led to the increasing fraction of β-sheets. Added drugs budesonide and ketoprofen prevented β-sheet formation and studied PLL(DBSA)-drug nanoparticles were in the α-helical conformation. Preliminary studies showed that ketoprofen released with a slower rate than budesonide which was hypothesized to result from different localization of drugs within the PLL(DBSA) nanoparticles. These results instruct to prepare polypeptide aerosol nanoparticles with internal self-assembled structures and to control the secondary structures by aerosol solvent annealing, which we foresee to be useful, e.g., toward controlling the release of poorly soluble drug molecules.

  17. Comparison of volatile components in Chinese traditional pickled peppers using HS-SPME-GC-MS, GC-O and multivariate analysis.

    PubMed

    Xiao, Z B; Zhu, J C; Feng, T; Tian, H X; Yu, H Y; Niu, Y W; Zhang, X M

    2010-12-01

    Volatile compounds of Chinese traditional pickled peppers (CTPPs) were extracted by solid-phase micro-extraction (SPME) and analysed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) to visually compare their volatile compositions by applying principal component analysis (PCA). A total of 67 volatile components were identified by GC-MS, including 7 acids, 6 alkanes, 14 alcohols, 9 esters, 11 terpenes, 3 aldehydes, 5 ketones, 7 phenols and 5 miscellaneous compounds, tentatively identified or identified by comparing with mass spectra and retention indices of the standards or from literature. Of 45 volatile compounds detected in the sniffing port of GC-O, the majority of odour-active components included acetic acid, 2-ethyl phenol, L-linalool, tridecane, butyl butanoate, δ-3-carene. The individual concentrations of the volatile compounds such as acetic acid, ethanol, 1-propanol, L-linalool, hexyl 2-methyl butyrate and hexyl pentanoate corresponded well to the intensities of related attributes in the correlation analysis. Due to their high concentration level and low threshold value, these compounds played an important role in the final aromatic profile of the pickled peppers. The differences in flavours were observed by applying PCA to GC-MS data sets. From the PCA results, samples were primarily separated along the first principal component.

  18. A toxicologic and dermatologic assessment of cinnamyl phenylpropyl materials when used as fragrance ingredients.

    PubMed

    Belsito, D; Bickers, D; Bruze, M; Calow, P; Dagli, M; Fryer, A D; Greim, H; Miyachi, Y; Saurat, J H; Sipes, I G

    2011-12-01

    The cinnamyl phenylpropyl fragrance ingredients are a diverse group of chemical structures that have similar metabolic and toxicity profiles. A toxicological and dermatological review of these fragrance ingredients is presented. The common characteristic structural element of cinnamyl phenylpropyl materials is an aryl substituted primary alcohol/aldehyde/ester. For high end users, calculated maximum dermal exposures vary from 0.14% to 0.72%; systemic exposures vary from 0.0002 to 0.0280 mg/kg/day. Human dermatological studies show that these materials are not generally irritants or sensitizers at lower exposures from consumer products. Reactions (0.9%) in fragrance sensitive patients were observed with 3-phenyl-1-propanol at 5% in petrolatum. The cinnamyl phenylpropyl materials had low acute toxicity and no significant toxicity in repeat dose oral or dermal toxicity studies. No mutagenic or genotoxic activity in bacteria and mammalian cell line assays was observed. The cinnamyl phenylpropyl alcohol materials participate in the same beta oxidation pathways as their parent cinnamic acid derivatives, including common routes of absorption, distribution, and metabolic detoxification, and exhibit similar toxicological endpoints. Based on the review of available data, it is concluded that these materials would not present a safety concern at current levels of use as fragrance ingredients.

  19. Phase behavior and second osmotic virial coefficient for competitive polymer solvation in mixed solvent solutions

    NASA Astrophysics Data System (ADS)

    Dudowicz, Jacek; Freed, Karl F.; Douglas, Jack F.

    2015-11-01

    We apply our recently developed generalized Flory-Huggins (FH) type theory for the competitive solvation of polymers by two mixed solvents to explain general trends in the variation of phase boundaries and solvent quality (quantified by the second osmotic virial coefficient B 2 ) with solvent composition. The complexity of the theoretically predicted miscibility patterns for these ternary mixtures arises from the competitive association between the polymer and the solvents and from the interplay of these associative interactions with the weak van der Waals interactions between all components of the mixture. The main focus here lies in determining the influence of the free energy parameters for polymer-solvent association (solvation) and the effective FH interaction parameters {χαβ} (driving phase separation) on the phase boundaries (specifically the spinodals), the second osmotic virial coefficient B 2 , and the relation between the positions of the spinodal curves and the theta temperatures at which B 2 vanishes. Our classification of the predicted miscibility patterns is relevant to numerous applications of ternary polymer solutions in industrial formulations and the use of mixed solvent systems for polymer characterization, such as chromatographic separation where mixed solvents are commonly employed. A favorable comparison of B 2 with experimental data for poly(methyl methacrylate)/acetonitrile/methanol (or 1-propanol) solutions only partially supports the validity of our theoretical predictions due to the lack of enough experimental data and the neglect of the self and mutual association of the solvents.

  20. The Search for a Volatile Human Specific Marker in the Decomposition Process

    PubMed Central

    Rosier, E.; Loix, S.; Develter, W.; Van de Voorde, W.; Tytgat, J.; Cuypers, E.

    2015-01-01

    In this study, a validated method using a thermal desorber combined with a gas chromatograph coupled to mass spectrometry was used to identify the volatile organic compounds released during decomposition of 6 human and 26 animal remains in a laboratory environment during a period of 6 months. 452 compounds were identified. Among them a human specific marker was sought using principle component analysis. We found a combination of 8 compounds (ethyl propionate, propyl propionate, propyl butyrate, ethyl pentanoate, pyridine, diethyl disulfide, methyl(methylthio)ethyl disulfide and 3-methylthio-1-propanol) that led to the distinction of human and pig remains from other animal remains. Furthermore, it was possible to separate the pig remains from human remains based on 5 esters (3-methylbutyl pentanoate, 3-methylbutyl 3-methylbutyrate, 3-methylbutyl 2-methylbutyrate, butyl pentanoate and propyl hexanoate). Further research in the field with full bodies has to corroborate these results and search for one or more human specific markers. These markers would allow a more efficiently training of cadaver dogs or portable detection devices could be developed. PMID:26375029

  1. Characterization of volatile compounds in chilled cod (Gadus morhua) fillets by gas chromatography and detection of quality indicators by an electronic nose.

    PubMed

    Olafsdottir, Gudrun; Jonsdottir, Rosa; Lauzon, Hélène L; Luten, Joop; Kristbergsson, Kristberg

    2005-12-28

    Volatile compounds in cod fillets packed in Styrofoam boxes were analyzed during chilled storage (0.5 degrees C) by gas chromatography (GC)-mass spectrometry and GC-olfactometry to screen potential quality indicators present in concentrations high enough for detection by an electronic nose. Photobacterium phosphoreum dominated the spoilage bacteria on day 12 when the fillets were rejected by sensory analysis. Ketones, mainly 3-hydroxy-2-butanone, were detected in the highest level (33%) at sensory rejection, followed by amines (TMA) (29%), alcohols (15%), acids (4%), aldehydes (3%), and a low level of esters (<1%). The electronic nose's CO sensor showed an increasing response with storage time coinciding with the production of ethanol and 2-methyl-1-propanol that were produced early in the storage, followed by the production of 3-methyl-1-butanol, 3-methyl-butanal, 2,3-butandiol, and ethyl acetate. Lipid-derived aldehydes, like hexanal and decanal, were detected in similar levels throughout the storage time and contributed to the overall sweet odors of cod fillets in combination with other carbonyls (3-hydroxy-2-butanone, acetaldehyde, 2-butanone, 3-pentanone, and 6-methyl-5-heptene-2-one).

  2. New organic aerogels based upon a phenolic-furfural reaction

    SciTech Connect

    Hrubesh, L.W.

    1994-09-01

    The aqueous polycondensation of (1) resorcinol with formaldehyde and (2) melamine with formaldehyde are two proven synthetic routes for the formation of organic aerogels. Recently, we have discovered a new type of organic aerogel based upon a phenolic-furfural (PF) reaction. This sol-gel polymerization has a major advantage over past approaches since it can be conducted in alcohol (e.g., 1-propanol), thereby eliminating the need for a solvent exchange step prior to supercritical drying from carbon dioxide. The resultant aerogels are dark brown in color and can be converted to a carbonized version upon pyrolysis in an inert atmosphere. BET surface areas of 350--600 m{sup 2}/g have been measured, and transmission electron microscopy reveals an interconnected structure of irregularly-shaped particles or platelets with {approximately}10 nm dimensions. Thermal conductivities as low as 0.015 W/m-K have been recorded for PF aerogels under ambient conditions. This paper describes the chemistry-structure-property relationships of these new materials in detail.

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

    PubMed

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

    2009-08-01

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

  4. Volatile compounds in whole meal bread crust: The effects of yeast level and fermentation temperature.

    PubMed

    Nor Qhairul Izzreen, M N; Hansen, Se S; Petersen, Mikael A

    2016-11-01

    The influence of fermentation temperatures (8°C, 16°C, and 32°C) and yeast levels (2%, 4%, and 6% of the flour) on the formation of volatile compounds in the crust of whole meal wheat bread was investigated. The fermentation times were regulated to optimum bread height for each treatment. The volatile compounds were extracted by dynamic headspace extraction and analyzed by gas chromatography-mass spectrometry. The results were evaluated using multivariate data analysis and ANOVA. In all crust samples 28 volatile compounds out of 58 compounds were identified and the other 30 compounds were tentatively identified. Higher fermentation temperatures promoted the formation of Maillard reaction products 3-methyl-1-butanol, pyrazine, 2-ethylpyrazine, 2-ethyl-3-methylpyrazine, 2-vinylpyrazine, 3-hydroxy-2-butanone, 3-(methylsulfanyl)-propanal, and 5-methyl-2-furancarboxaldehyde whereas at lower temperature (8°C) the formation of 2- and 3-methylbutanal was favored. Higher levels of yeast promoted the formation of 3-methyl-1-butanol, 2-methyl-1-propanol and 3-(methylsulfanyl)-propanal, whereas hexanal was promoted in the crust fermented with lower yeast level. PMID:27211683

  5. Effects of Fermentation Temperature on Key Aroma Compounds and Sensory Properties of Apple Wine.

    PubMed

    Peng, Bangzhu; Li, Fuling; Cui, Lu; Guo, Yaodong

    2015-12-01

    Fermentation temperature strongly affects yeast metabolism during apple wine making and thus aromatic and quality profiles. In this study, the temperature effect during apple wine making on both the key aroma compounds and sensory properties of apple wine were investigated. The concentration of nine key aroma compounds (ethyl acetate, isobutyl acetate, isopentylacetate, ethyl caprylate, ethyl 4-hydroxybutanoate, isobutylalcohol, isopentylalcohol, 3-methylthio-1-propanol, and benzeneethanol) in apple wine significantly increased with the increase of fermentation temperature from 17 to 20 °C, and then eight out of the nine key aroma compounds with an exception of ethyl 4-hydroxybutanoate, decreased when the temperature goes up 20 to 26 °C. Sensory analysis showed that the apple wine fermented at 20 °C had the highest acceptance for consumers. Fermentation at the temperature of 20 °C was therefore considered to be the most suitable condition using the selected yeast strain (Saccharomyces cerevisiae AP05) for apple wine making. Changes in the fermentation temperature can considerably affect the production of key aroma compounds and sensory profiles of apple wine. These results could help apple wine producers make better quality production for consumers at the optimal fermentation temperature. PMID:26509667

  6. Effects of Fermentation Temperature on Key Aroma Compounds and Sensory Properties of Apple Wine.

    PubMed

    Peng, Bangzhu; Li, Fuling; Cui, Lu; Guo, Yaodong

    2015-12-01

    Fermentation temperature strongly affects yeast metabolism during apple wine making and thus aromatic and quality profiles. In this study, the temperature effect during apple wine making on both the key aroma compounds and sensory properties of apple wine were investigated. The concentration of nine key aroma compounds (ethyl acetate, isobutyl acetate, isopentylacetate, ethyl caprylate, ethyl 4-hydroxybutanoate, isobutylalcohol, isopentylalcohol, 3-methylthio-1-propanol, and benzeneethanol) in apple wine significantly increased with the increase of fermentation temperature from 17 to 20 °C, and then eight out of the nine key aroma compounds with an exception of ethyl 4-hydroxybutanoate, decreased when the temperature goes up 20 to 26 °C. Sensory analysis showed that the apple wine fermented at 20 °C had the highest acceptance for consumers. Fermentation at the temperature of 20 °C was therefore considered to be the most suitable condition using the selected yeast strain (Saccharomyces cerevisiae AP05) for apple wine making. Changes in the fermentation temperature can considerably affect the production of key aroma compounds and sensory profiles of apple wine. These results could help apple wine producers make better quality production for consumers at the optimal fermentation temperature.

  7. Acid Lipase from Candida viswanathii: Production, Biochemical Properties, and Potential Application

    PubMed Central

    de Almeida, Alex Fernando; Carmona, Eleonora Cano

    2013-01-01

    Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U) was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield (YL/S = 1.381 g/g), lipase yield (YL/S = 6.892 U/g), and biomass productivity (PX = 0.282 g/h). Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield (YL/S) of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties. PMID:24350270

  8. First-Principles Exploration of the Competing Mechanisms for the Sign Preference in Ion-induced Nucleation

    NASA Astrophysics Data System (ADS)

    Xu, Liubin; Chen, Wei; Cui, Ping; Zhang, Zhenyu

    2015-03-01

    Ion-induced nucleation plays an important part in aerosol formation, under both atmospheric and experimental conditions. However, the dominant mechanism underlying the so-called sign preference, a phenomenon that ions of the same magnitude of charge but opposite signs exhibit notably different enhancement of nucleation, remains an enigma. Recent experiments revealed a negative charge affinity of 1-propanol molecules condensing on tungsten oxide seeds, while prevailing first-principles calculations indicated a positive preference. In this study, we investigate the adsorption of organic molecules on charged transition metal oxide via density functional theory (DFT) calculations by including new physical factors that were absent in previous theoretical studies. First, we demonstrate the significant role of van der Waals interactions in such systems. Furthermore, we show that the change of charge state effectively varies the spin moment of the seeds, which can be utilized to selectively influence the strengths of the intermolecular bindings. These new factors may prove to be instrumental in gaining an eventual complete understanding of the long-standing sign preference puzzle in ion-induced nucleation.

  9. Thermal desorption gas chromatography with mass spectrometry study of outgassing from polymethacrylimide foam (Rohacell®).

    PubMed

    Carrasco-Correa, Enrique J; Herrero-Martínez, José M; Consuegra, Lina; Ramis-Ramos, Guillermo; Sanz, Rafael Mata; Martínez, Benito Gimeno; Esbert, Vicente E Boria; García-Baquero, David Raboso

    2015-09-01

    Polymethacrylimide foams are used as light structural materials in outer-space devices; however, the foam closed cells contain volatile compounds that are outgassed even at low temperatures. These compounds ignite as plasmas under outer-space radiation and the intense radio-frequency fields used in communications. Since plasmas may cause spacecraft fatal events, the conditions in which they are ignited should be investigated. Therefore, qualitative and quantitative knowledge about polymethacrylimide foam outgassing should be established. Using thermogravimetric analysis, weight losses reached 3% at ca. 200°C. Thermal desorption gas chromatography with mass spectrometry detection was used to study the offgassed compounds. Using successive 4 min heating cycles at 125°C, each one corresponding to an injection, significant amounts of nitrogen (25.3%), water (2.6%), isobutylene (11.3%), tert-butanol (2.9%), 1-propanol (11.9%), hexane (25.3%), propyl methacrylate (1.4%), higher hydrocarbons (11.3%), fatty acids (2.2%) and their esters (1.3%), and other compounds were outgassed. Other compounds were observed during the main stage of thermal destruction (220-280°C). A similar study at 175°C revealed the extreme difficulty in fully outgassing polar compounds from polymethacrylimide foams by baking and showed the different compositions of the offgassed atmosphere that can be expected in the long term. PMID:26106018

  10. Dielectric Study of Alcohols Using Broadband Terahertz Time Domain Spectroscopy (THz-TDS).

    NASA Astrophysics Data System (ADS)

    Sarkar, Sohini; Saha, Debasis; Banerjee, Sneha; Mukherjee, Arnab; Mandal, Pankaj

    2016-06-01

    Broadband Terahertz-Time Domain Spectroscopy (THz-TDS) (1-10 THz) has been utilized to study the complex dielectric properties of methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, and 1-octanol. Previous reports on dielectric study of alcohols were limited to 5 THz. At THz (1 THz = 33.33 wn = 4 meV) frequency range (0.1 to 15 THz), the molecular reorientation and several intermolecular vibrations (local oscillation of dipoles) may coexist and contribute to the overall liquid dynamics. We find that the Debye type relaxations barely contribute beyond 1 THz, rather three harmonic oscillators dominate the entire spectral range. To get insights on the modes responsible for the observed absorption in THz frequency range, we performed all atom molecular dynamics (MD) using OPLS force field and ab initio quantum calculations. Combined experimental and theoretical study reveal that the complex dielectric functions of alcohols have contribution from a) alkyl group oscillation within H-bonded network ( 1 THz), b) intermolecular H-bond stretching ( 5 THz) , and c) librational motions in alcohols. The present work, therefore, complements all previous studies on alcohols at lower frequencies and provides a clear picture on them in a broad spectral range from microwave to 10 THz.

  11. Rotational Spectrum of Neopentyl Alcohol, (CH_3)_3CCH_2OH

    NASA Astrophysics Data System (ADS)

    Kisiel, Zbigniew; Pszczołkowski, Lech; Xue, Zhifeng; Suhm, Martin A.

    2012-06-01

    The rotational spectrum of neopentyl alcohol (2,2-dimethyl-1-propanol, (CH_3)_3CCH_2OH) has been investigated for the first time. This molecule differs from ethanol only in having the ^tBu group instead of the methyl group, and is likewise anticipated to exhibit two spectroscopic species, with trans and gauche hydroxyl orientation. Quantum chemistry computations predict the trans to be the more stable species. Rotational transitions of both species have now been assigned in supersonic expansion cm-wave FTMW experiment and in room temperature, mm-wave spectra up to 280 GHz. The supersonic expansion measurements with Ar carrier gas confirm that trans is the global minimum species. The trans spectrum is predominantly b-type, while the gauche is predominantly a-type and the frequencies of rotational transitions in both species appear to be perturbed in different ways. The results from effective and from coupled Hamiltonian fits for neopentyl alcohol are presented, and are compared with predictions from ab initio calculations.

  12. Preparation and characterization of alkyl methacrylate-based monolithic columns for capillary gas chromatography applications.

    PubMed

    Yusuf, Kareem; Aqel, Ahmad; A L Othman, Zeid; Badjah-Hadj-Ahmed, Ahmed Yacine

    2013-08-01

    Gas chromatography (GC) is considered the least common application of both polymer and silica-based monolithic columns. This study describes the fabrication of alkyl methacrylate monolithic materials for use as stationary phases in capillary gas chromatography. Following the deactivation of the capillary surface with 3-(trimethoxysilyl)propyl methacrylate (TMSM), the monoliths were formed by the co-polymerization of either hexyl methacrylate (HMA) or lauryl methacrylate (LMA) with different percentage of ethylene glycol dimethacrylate (EDMA) in presence of an initiator (azobisisobutyronitrile, AIBN) and a mixture of porogens include 1-propanol, 1,4-butanediol and water. The monoliths were prepared in 500mm length capillaries possessing inner diameters of 250μm. The efficiencies of the monolithic columns for low molecular weight compounds significantly improved as the percentage of crosslinker was increased, because of the greater proportion of pores less than 50nm. The columns containing lower percentages of crosslinker were able to rapidly separate a series of 8 alkane members in 0.7min, but the separation was less efficient for the light alkanes. Columns prepared with the lauryl methacrylate monomer yielded a different morphology for the monolith-interconnected channels. The channels were more branched, which increased the separation time, and unlike the other columns, allowed for temperature programming.

  13. Postmortem degradation of administered ethanol-d6 and production of endogenous ethanol: experimental studies using rats and rabbits.

    PubMed

    Takayasu, T; Ohshima, T; Tanaka, N; Maeda, H; Kondo, T; Nishigami, J; Nagano, T

    1995-12-18

    Deuterium-labeled ethanol-d6 was employed to study the metabolism and postmortem change of ethanol in putrefied organ tissues. First, 4 ml/kg body weight of 25% (w/v) solution of ethanol-d6 was administered orally to each of 15 rats. The heart blood and organs were collected 15-90 min after the administration and the ethanol-d6 was analyzed by head space gas chromatography/mass spectrometry. The ethanol-d6 concentration in the organ tissues reached its maximum at 15 min after the administration and then gradually declined, showing the same pattern as human ethanol metabolism. Ethanol-d6 (3 ml of the same solution/kg body weight) was injected into the vein of a rabbit's ear (total of 12 rabbits). The rabbit was killed with carbon monoxide 30 min after the administration and the carcass was allowed to stand for 1-4 days at 30 degrees C in a moist chamber. The concentration of ethanol-d6 decreased moderately. Postmortem ethanol and 1-propanol concentrations, in contrast, showed marked increases 2.5 days and more after sacrifice in line with the degree of putrefaction of each organ tissue including skeletal muscle. This suggests the postmortem activation of micro-organism activity. These results indicate that ethanol concentrations in cadaver tissues must be carefully assessed with due consideration of postmortem degradation and production.

  14. Preparation of magnetite/poly(styrene-divinylbenzene) nanoparticles for selective enrichment-determination of fenitrothion in environmental and biological samples.

    PubMed

    Eskandari, Habibollah; Naderi-Darehshori, Ali

    2012-09-19

    In the present study, a cross-linked nano-sized spherical magnetic poly(styrene-divinylbenzene) is synthesized and used as an adsorbent for enrichment-determination of fenitrothion. A miniemulsion polymerization procedure was used to prepare the adsorbent. The magnetic adsorbent was characterized by FT-IR, SEM and TEM. The prepared magnetic adsorbent nanoparticles were mixed with magnetite nanoparticles for faster and more efficient magnetic precipitation. The reduced fenitrothion was coupled with 3-methyl-2-benzothiazolinone hydrazone and then the blue colored complex was extracted. The blue derivative of fenitrothion was eluted by a 1 mL aliquot of 1-propanol prior to spectrophotometry at 571 nm. Beer's law was obeyed in the range of 2-230 ng mL(-1) of fenitrothion with relative standard deviation and recovery in the ranges of 0.9-5.1% and 97.2-100.0%, respectively. Selectivity of the method was evaluated, and the method was successfully applied to the determination of fenitrothion in various water, soil, urine and human plasma samples.

  15. Dielectric barrier discharge carbon atomic emission spectrometer: universal GC detector for volatile carbon-containing compounds.

    PubMed

    Han, Bingjun; Jiang, Xiaoming; Hou, Xiandeng; Zheng, Chengbin

    2014-01-01

    It was found that carbon atomic emission can be excited in low temperature dielectric barrier discharge (DBD), and an atmospheric pressure, low power consumption, and compact microplasma carbon atomic emission spectrometer (AES) was constructed and used as a universal and sensitive gas chromatographic (GC) detector for detection of volatile carbon-containing compounds. A concentric DBD device was housed in a heating box to increase the plasma operation temperature to 300 °C to intensify carbon atomic emission at 193.0 nm. Carbon-containing compounds directly injected or eluted from GC can be decomposed, atomized, and excited in this heated DBD for carbon atomic emission. The performance of this new optical detector was first evaluated by determination of a series of volatile carbon-containing compounds including formaldehyde, ethyl acetate, methanol, ethanol, 1-propanol, 1-butanol, and 1-pentanol, and absolute limits of detection (LODs) were found at a range of 0.12-0.28 ng under the optimized conditions. Preliminary experimental results showed that it provided slightly higher LODs than those obtained by GC with a flame ionization detector (FID). Furthermore, it is a new universal GC detector for volatile carbon-containing compounds that even includes those compounds which are difficult to detect by FID, such as HCHO, CO, and CO2. Meanwhile, hydrogen gas used in conventional techniques was eliminated; and molecular optical emission detection can also be performed with this GC detector for multichannel analysis to improve resolution of overlapped chromatographic peaks of complex mixtures. PMID:24328147

  16. In vitro study on the disinfectability of two split-septum needle-free connection devices using different disinfection procedures

    PubMed Central

    Engelhart, Steffen; Exner, Martin; Simon, Arne

    2015-01-01

    This in vitro study investigated the external disinfection of two needle-free connection devices (NFC) using Octeniderm® (spraying and wiping technique) vs. Descoderm® pads (wiping technique). The split-septum membrane of the NFC was contaminated with >105 CFU K. pneumoniae or S. epidermidis. The efficacy of the disinfection at 30 sec. exposure time was controlled by taking a swab sample and by flushing the NFC with sterile 0.9% sodium chloride solution. Disinfection with octenidine dihydrochloride 0.1 g, 1-Propanol 30.0 g, and 2-Propanol 45.0 g in 100 g solution was highly effective (CFU reduction ≥4 log) against both microorganisms, whereas the use of 63.1 g 2-Propanol in 100 ml solution led to residual contamination with S. epidermidis. Our investigation underlines that (i) in clinical practice disinfection of NFCs before use is mandatory, and that (ii) details of disinfection technique are of utmost importance regarding their efficacy. Our investigation revealed no significant differences between both split-septum NFC types. Clinical studies are needed to confirm a possible superiority of disinfectants with long-lasting residual antimicrobial activity. PMID:26693394

  17. Oxidation, Reduction, and Condensation of Alcohols over (MO3)3 (M=Mo, W) Nanoclusters

    SciTech Connect

    Fang, Zongtang; Li, Zhenjun; Kelley, Matthew S.; Kay, Bruce D.; Li, Shenggang; Hennigan, Jamie M.; Rousseau, Roger J.; Dohnalek, Zdenek; Dixon, David A.

    2014-10-02

    The reactions of deuterated methanol, ethanol, 1-propanol, 1-butanol, 2-propanol, 2-butanol and t-butanol over cyclic (MO3)3 (M = Mo, W) clusters were studied experimentally with temperature programmed desorption (TPD) and theoretically with coupled cluster CCSD(T) theory and density functional theory. The reactions of two alcohols per M3O9 cluster are required to provide agreement with experiment for D2O release, dehydrogenation and dehydration. The reaction begins with the elimination of water by proton transfers and forms an intermediate dialkoxy species which can undergo further reaction. Dehydration proceeds by a β hydrogen transfer to a terminal M=O. Dehydrogenation takes place via an α hydrogen transfer to an adjacent MoVI = O atom or a WVI metal center with redox involved for M = Mo and no redox for M = W. The two channels have comparable activation energies. H/D exchange to produce alcohols can take place after olefin is released or via the dialkoxy species depending on the alcohol and the cluster. The Lewis acidity of the metal center with WVI being larger than MoVI results in the increased reactivity of W3O9 over Mo3O9 for dehydrogenation and dehydration.

  18. Flow Synthesis of 2-Methylpyridines via α-Methylation.

    PubMed

    Manansala, Camille; Tranmer, Geoffrey K

    2015-01-01

    A series of simple 2-methylpyridines were synthesized in an expedited and convenient manner using a simplified bench-top continuous flow setup. The reactions proceeded with a high degree of selectivity, producing α-methylated pyridines in a much greener fashion than is possible using conventional batch reaction protocols. Eight 2-methylated pyridines were produced by progressing starting material through a column packed with Raney(®) nickel using a low boiling point alcohol (1-propanol) at high temperature. Simple collection and removal of the solvent gave products in very good yields that were suitable for further use without additional work-up or purification. Overall, this continuous flow method represents a synthetically useful protocol that is superior to batch processes in terms of shorter reaction times, increased safety, avoidance of work-up procedures, and reduced waste. A brief discussion of the possible mechanism(s) of the reaction is also presented which involves heterogeneous catalysis and/or a Ladenberg rearrangement, with the proposed methyl source as C1 of the primary alcohol. PMID:26334262

  19. Aminiphilus circumscriptus gen. nov., sp. nov., an anaerobic amino-acid-degrading bacterium from an upflow anaerobic sludge reactor.

    PubMed

    Díaz, C; Baena, S; Fardeau, M-L; Patel, B K C

    2007-08-01

    Strain ILE-2(T) was isolated from an upflow anaerobic sludge bed reactor treating brewery wastewater. The motile, non-sporulating, slightly curved cells (2-4 x 0.1 microm) stained Gram-negative and grew optimally at 42 degrees C and pH 7.1 with 0.5 % NaCl. The strain required yeast extract for growth and fermented Casamino acids, peptone, isoleucine, arginine, lysine, alanine, valine, glutamate, histidine, glutamine, methionine, malate, fumarate, glycerol and pyruvate to acetate, propionate and minor amounts of branched-chain fatty acids. Carbohydrates, formate, acetate, propionate, butyrate, isovalerate, methanol, ethanol, 1-propanol, butanol, lactate, succinate, starch, casein, gelatin, xylan and a number of other amino acids were not utilized. The DNA G+C content of strain ILE-2(T) was 52.7 mol%. 16S rRNA gene sequence analysis revealed that ILE-2(T) was distantly related to members of the genera Aminobacterium (83 % similarity) and Aminomonas (85 % similarity) in the family Syntrophomonadaceae, order Clostridiales, phylum Firmicutes. On the basis of the results of our polyphasic analysis, strain ILE-2(T) represents a novel species and genus within the family Syntrophomonadaceae, for which the name Aminiphilus circumscriptus gen. nov., sp. nov. is proposed. The type strain of Aminiphilus circumscriptus is ILE-2(T) (=DSM 16581(T) =JCM 14039(T)). PMID:17684281

  20. Physicochemical aspects of epoxide driven nano-ZrO2 hydrogel formation: milder kinetics for better properties.

    PubMed

    Oestreicher, V; Perullini, M; Jobbágy, M

    2016-06-14

    Robust and highly transparent quasi amorphous ZrO2-water-glycerol hydrogels were obtained in a mild one pot procedure, based on the 2,3-epoxy-1-propanol driven alkalinization. SAXS-based characterization of the sol-gel transition revealed that an homogeneously nucleated sol composed of 2 nm primary particles continuously grows up to a critical size of 5-6 nm, when gelation takes place. These particles reach a size of 8-10 nm, depending on the Zr(iv) concentration. Conductivity measurements offer an overall in situ assessment of the reaction rate. The gelled samples share a common trend: once the conductivity decays to 40% of the starting value, the primary particles nucleate and when this decay reaches 20%, the sol-gel transition takes place. The mild conditions employed herein prevent massive ripening and recrystallization leaving hydrogels with extremely low undesired visible light scattering. This suitable nanostructure was achieved in a wide range of total Zr(iv) concentrations or water to glycerol ratios.

  1. Experiments on bifurcation of periodic states into tori for a periodically forced chemical oscillator

    NASA Astrophysics Data System (ADS)

    Vance, William; Ross, John

    1988-05-01

    We study experimentally continuous transitions from quasiperiodic to periodic states for a time-periodically forced chemical oscillator. The chemical reaction is the hydration of 2,3-epoxy-1-propanol, and is carried out in a continuous stirred tank reactor (CSTR). Periodic oscillatory states are observed to arise in the autonomous system through supercritical Hopf bifurcations as either the total flow rate or the cooling coil temperature is changed. Under conditions of oscillation for the autonomous system, small-amplitude periodic variation of the total flow rate generates an attracting two-torus from the stable limit cycle. From the experiments we determine the structure of the toroidal flow, stroboscopic phase portraits, and circle maps as a function of the forcing amplitude and period. A continuous transition from the quasiperiodic to a periodic state, in which the two-torus contracts to a closed curve (Neimark-Sacker torus bifurcation), is observed as the forcing amplitude is increased at a constant forcing period, or as the forcing period is changed at a constant moderate forcing amplitude. Qualitative theoretical predictions compare well with the experimental observations. This paper presents the first experimental observation of a Neimark-Sacker torus bifurcation in a forced chemical oscillator system, and relates the bifurcation diagram of the unforced system to that of the forced system.

  2. Acid lipase from Candida viswanathii: production, biochemical properties, and potential application.

    PubMed

    de Almeida, Alex Fernando; Tauk-Tornisielo, Sâmia Maria; Carmona, Eleonora Cano

    2013-01-01

    Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U) was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield (Y L/S = 1.381 g/g), lipase yield (Y L/S = 6.892 U/g), and biomass productivity (P X = 0.282 g/h). Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield (Y L/S ) of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties. PMID:24350270

  3. Improved homopolymer separation to enable the application of 1H NMR and HPLC for the determination of the reaction parameters of the graft copolymerization of acrylic acid onto starch.

    PubMed

    Witono, Judy R; Marsman, Jan Henk; Noordergraaf, Inge-Willem; Heeres, Hero J; Janssen, Leon P B M

    2013-04-01

    Graft copolymers of starch with acrylic acid are a promising green, bio based material with many potential applications. The grafting of acrylic acid onto cassava starch in an aqueous medium initiated by Fenton's reagent has been studied. Common grafting result parameters are add-on (yield) and graft efficiency (selectivity). However, the analysis of the reaction products and an accurate determination of these parameters stand or fall with a complete separation of the entangled but ungrafted homopolymer from the grafted product. Therefore, this separation is the core of the newly developed analytical procedure. An appropriate solvent has been selected with dedicated testing from the range methanol, ethanol, acetone, dioxane, 2-propanol, and 1-propanol. Acetone showed the best performance in many respects. It has a high dissolving power for the homopolymer, as well as the highest yield of precipitation for the starch derivatives and it is the most economical in use. After the successful separation, the precipitated graft copolymers could be analyzed quantitatively by nuclear magnetic resonance. The liquid with homopolymer and unreacted monomer was analyzed by high pressure liquid chromatography. Proof of grafting has been found by FTIR and TGA analyses. The mass balance calculation shows a systematic error which appears fairly consistent: 18.0±2.5 wt%. This was used as a correction factor in the calculation of the grafting parameters but more importantly, it means that the method we developed has a high level of repeatability, in the order of 97%. PMID:23435285

  4. Purification and characterization of a hexanol-degrading enzyme extracted from apple.

    PubMed

    Zhu, Jing; Shi, Junling; Pan, Zhongli

    2012-03-28

    An enzyme having activity toward n-hexanol was purified from apple, and its biochemical characteristics were analyzed. The purification steps consisted of sedimentation with ammonium sulfate, DEAE Sepharose Fast Flow ion exchange chromatography, and Sephadex G-100 column. The obtained enzyme had a yield of 16.00% with a specific activity of 18879.20 U/mg protein and overall purification of 142.77-fold. The enzyme showed activity to isoamylol, 1-propanol, n-hexanol, and isobutanol but not toward methanol and ethanol. With n-hexanol as a substrate, the optimum conditions were pH 4.0 and 30 °C for enzyme activity and pH 3.0-4.0 and temperatures below 40 °C for enzyme stability. The enzyme activity was increased significantly by adding l-cysteine and Fe(2+) at all tested concentrations and slightly by Zn(2+) at a high concentration but decreased by additions of EDTA, Ga(2+), K(+), Mg(2+), sodium dodecyl sulfate (SDS), sodium aluminum sulfate (SAS), dithiothreitol (DTT), and glutathione (GSH). The enzyme activities toward n-hexanol and n-hexanal were increased by NADH but decreased by NAD(+), in contrast to a decrease toward n-hexane by addition of both NAD(+) and NADH.

  5. Monitoring of HAART regime antiretrovirals in serum of acquired immunodeficiency syndrome patients by micellar liquid chromatography.

    PubMed

    Casas-Breva, I; Peris-Vicente, J; Rambla-Alegre, M; Carda-Broch, S; Esteve-Romero, J

    2012-09-21

    A methodology based on micellar liquid chromatography to monitor five antiretroviral drugs (lamivudine, stavudine, tenofovir, zidovudine and efavirenz) was proposed. Antiretrovirals were studied in sets of three, corresponding to each highly active antiretroviral therapy (HAART) regime, prescribed to acquired immunodeficiency syndrome (AIDS)-infected patients. Four aqueous micellar mobile phases buffered at pH 7 were optimized to separate these compounds, using sodium dodecyl sulfate as the tensioactive, and 1-propanol or 1-pentanol as the organic modifier. The composition of each mobile phase was optimized for each antiretroviral. The common separation conditions were: C18 apolar column (125 × 4.6 mm, 5 μm particle size), UV detection set at 214 nm, and mobile phase running at 1 mL min(-1) without controlling the temperature. The finally suggested method was validated for five analysed antiretroviral drugs following the US Food and Drug Administration guidelines in terms of: linearity between 0.5 and 50 ppm (r(2) > 0.9995), sensitivity (LOD lower than 0.25 ppm), intra- and inter-day precision (<7.1 and <5.2%, respectively) and accuracy (recovery 88.5-105.3% and 93.5-101.3%, respectively), as well as robustness (<6.5%). The proposed method was used to monitor the level of antiretrovirals in the serum of AIDS patients. The suggested methodology was found to be useful in the routine analysis of antiretrovirals in serum samples.

  6. A sialic acid assay in isolation and purification of bovine k-casein glycomacropeptide: a review.

    PubMed

    Nakano, Takuo; Ozimek, Lech

    2014-01-01

    Sialic acid is a carbohydrate moiety of k-casein glycomacropeptide (GMP), which is a 64 amino acid residue C-terminal sialylated phosphorylated glycopeptide released from k-casein by the action of chymosin during cheese making. GMP lacks aromatic amino acids including phenylalanine, tyrosine, and tryptophan. Because of its unique amino acid composition and various biological activities, GMP is thought to be a potential ingredient for dietetic foods (e.g., a food for PKU patients) and pharmaceuticals. Thus, increased attention has been given to the development of techniques to purify GMP. In this review, techniques of GMP purification described in patents and scientific research papers were introduced. A sialic acid assay is the important method to track GMP isolation and purification processes, for which the thiobarbituric acid reaction with 1-propanol as a chromophore extracting solvent is an inexpensive, practical and specific technique. Sephacryl S-200 gel filtration chromatography, cellulose acetate electrophoresis, and sodium dodecyl sulfate polyacrylamide gel electrophoresis are the major techniques to identify sialic acid specific to GMP. Sephacryl S-200 chromatography and cellulose acetate electrophoresis are also used to detect GMP sialic acid in whey pearmeate and whey added commercial margarine samples. Future research includes development of an economical industrial scale method to produce high purity GMP.

  7. Analysis of some Italian lemon liquors (limoncello).

    PubMed

    Andrea, Versari; Nadia, Natali; Teresa, Russo Maria; Andrea, Antonelli

    2003-08-13

    The chemical composition of several commercial Italian Limoncellos, lemon-peel-based alcoholic beverages, was studied by chromatographic techniques. These methods allowed a rapid monitoring of Limoncello, giving information on quality markers and possible adulteration of the product. Quantitative data for more than 60 compounds are reported. Limoncellos were characterized by the presence of selected volatile (terpenes, aldehydes, alcohols) and nonvolatile compounds (psoralens, coumarins, phenolics, carbohydrates and acids). On the basis of their composition, the samples were grouped by PCA analysis in two sets; the first group showed a composition similar to lemon essential oils, with a high content of b-pinene, myrcene, trans-a-bergamottene, and b-bisabolene, and a low content in neral and geranial. The composition of the second group suggested the occurrence of oxidative phenomena and/or the addition of flavors. The presence of ethyl acetate, acetaldehyde, 2-methyl-1-propanol and glycerol showed that a fermentation probably occurred in the sugar syrup used to dilute the Limoncello after the extraction process.

  8. Preparation of optically active (2RS,3SR)-2-amino-3-hydroxy-3-phenylpropanoic acid (threo-beta-phenylserine) via optical resolutions by replacing and preferential crystallization.

    PubMed

    Shiraiwa, Tadashi; Kawashima, Yuka; Ikaritani, Atsushi; Suganuma, Yumiko; Saijoh, Reiichi

    2006-08-01

    To obtain optically active threo-2-amino-3-hydroxy-3-phenylpropanoic acid (1) via optical resolutions by replacing and preferential crystallization, the racemic structure of (2RS,3SR)-1 hydrochloride [(2RS,3SR)-1.HCl] was examined based on the melting point, solubility, and infrared spectrum. (2RS,3SR)-1.HCl was indicated to exist as a conglomerate at room temperature, although it forms a racemic compound at the melting point. When, in optical resolution by replacing crystallization, L-phenylalanine methyl ester hydrochloride (L-2) was used as the optically active co-solute, (2R,3S)-1.HCl was preferentially crystallized from the supersaturated racemic solution; the use of D-2 as the co-solute afforded (2S,3R)-1.HCl with an optical purity of 95%. In addition, optical resolution by preferential crystallization was successfully achieved to give successively (2R,3S)- and (2S,3R)-1.HCl with optical purities of 90-92%. The (2R,3S)- and (2S,3R)-1.HCl purified by recrystallization from 1-propanol were treated with triethylamine in methanol to give optically pure (2R,3S)- and (2S,3R)-1.

  9. A Sphingolipid Inhibitor Induces a Cytokinesis Arrest and Blocks Stage Differentiation in Giardia lamblia▿

    PubMed Central

    Sonda, Sabrina; Štefanić, Saša; Hehl, Adrian B.

    2008-01-01

    Sphingolipid biosynthesis pathways have recently emerged as a promising target for therapeutic intervention against pathogens, including parasites. A key step in the synthesis of complex sphingolipids is the glucosylation of ceramide, mediated by glucosylceramide (GlcCer) synthase, whose activity can be inhibited by PPMP (1-phenyl-2-palmitoylamino-3-morpholino-1-propanol). In this study, we investigated whether PPMP inhibits the proliferation and differentiation of the pathogenic parasite Giardia lamblia, the major cause of parasite-induced diarrhea worldwide. PPMP was found to block in vitro parasite replication in a dose-dependent manner, with a 50% inhibitory concentration of 3.5 μM. The inhibition of parasite replication was irreversible at 10 μM PPMP, a concentration that did not affect mammalian cell metabolism. Importantly, PPMP inhibited the completion of cell division at a specific stage in late cytokinesis. Microscopic analysis of cells incubated with PPMP revealed the aberrant accumulation of cellular membranes belonging to the endoplasmic reticulum network in the caudal area of the parasites. Finally, PPMP induced a 90% reduction in G. lamblia differentiation into cysts, the parasite stage responsible for the transmission of the disease. These results show that PPMP is a powerful inhibitor of G. lamblia in vitro and that as-yet-uncharacterized sphingolipid biosynthetic pathways are potential targets for the development of anti-G. lamblia agents. PMID:18086854

  10. A sphingolipid inhibitor induces a cytokinesis arrest and blocks stage differentiation in Giardia lamblia.

    PubMed

    Sonda, Sabrina; Stefanic, Sasa; Hehl, Adrian B

    2008-02-01

    Sphingolipid biosynthesis pathways have recently emerged as a promising target for therapeutic intervention against pathogens, including parasites. A key step in the synthesis of complex sphingolipids is the glucosylation of ceramide, mediated by glucosylceramide (GlcCer) synthase, whose activity can be inhibited by PPMP (1-phenyl-2-palmitoylamino-3-morpholino-1-propanol). In this study, we investigated whether PPMP inhibits the proliferation and differentiation of the pathogenic parasite Giardia lamblia, the major cause of parasite-induced diarrhea worldwide. PPMP was found to block in vitro parasite replication in a dose-dependent manner, with a 50% inhibitory concentration of 3.5 muM. The inhibition of parasite replication was irreversible at 10 muM PPMP, a concentration that did not affect mammalian cell metabolism. Importantly, PPMP inhibited the completion of cell division at a specific stage in late cytokinesis. Microscopic analysis of cells incubated with PPMP revealed the aberrant accumulation of cellular membranes belonging to the endoplasmic reticulum network in the caudal area of the parasites. Finally, PPMP induced a 90% reduction in G. lamblia differentiation into cysts, the parasite stage responsible for the transmission of the disease. These results show that PPMP is a powerful inhibitor of G. lamblia in vitro and that as-yet-uncharacterized sphingolipid biosynthetic pathways are potential targets for the development of anti-G. lamblia agents. PMID:18086854

  11. Production of CaCO3/hyperbranched polyglycidol hybrid films using spray-coating technique.

    PubMed

    Malinova, Kalina; Gunesch, Manfred; Montero Pancera, Sabrina; Wengeler, Robert; Rieger, Bernhard; Volkmer, Dirk

    2012-05-15

    Biomineralizing organisms employ macromolecules and cellular processing strategies in order to produce highly complex composite materials such as nacre. Bionic approaches translating this knowledge into viable technical production schemes for a large-scale production of biomimetic hybrid materials have met with limited success so far. Investigations presented here thus focus on the production of CaCO(3)/polymer hybrid coatings that can be applied to huge surface areas via reactive spray-coating. Technical requirements for simplicity and cost efficiency include a straightforward one-pot synthesis of low molecular weight hyperbranched polyglycidols (polyethers of 2,3-epoxy-1-propanol) as a simple mimic of biological macromolecules. Polymers functionalized with phosphate monoester, sulfate or carboxylate groups provide a means of controlling CaCO(3) particle density and morphology in the final coatings. We employ reactive spray-coating techniques to generate CaCO(3)/hybrid coatings among which vaterite composites can be prepared in the presence of sulfate-containing hyperbranched polyglycidol. These coatings show high stability and remained unchanged for periods longer than 9 months. By employing carboxylate-based hyperbranched polyglycidol, it is possible to deposit vaterite-calcite composites, whereas phosphate-ester-based hyperbranched polyglycidol leads to calcite composites. Nanoindentation was used to study mechanical properties, showing that coatings thus obtained are slightly harder than pure calcite.

  12. Physicochemical aspects of epoxide driven nano-ZrO2 hydrogel formation: milder kinetics for better properties.

    PubMed

    Oestreicher, V; Perullini, M; Jobbágy, M

    2016-06-14

    Robust and highly transparent quasi amorphous ZrO2-water-glycerol hydrogels were obtained in a mild one pot procedure, based on the 2,3-epoxy-1-propanol driven alkalinization. SAXS-based characterization of the sol-gel transition revealed that an homogeneously nucleated sol composed of 2 nm primary particles continuously grows up to a critical size of 5-6 nm, when gelation takes place. These particles reach a size of 8-10 nm, depending on the Zr(iv) concentration. Conductivity measurements offer an overall in situ assessment of the reaction rate. The gelled samples share a common trend: once the conductivity decays to 40% of the starting value, the primary particles nucleate and when this decay reaches 20%, the sol-gel transition takes place. The mild conditions employed herein prevent massive ripening and recrystallization leaving hydrogels with extremely low undesired visible light scattering. This suitable nanostructure was achieved in a wide range of total Zr(iv) concentrations or water to glycerol ratios. PMID:26974822

  13. Acid lipase from Candida viswanathii: production, biochemical properties, and potential application.

    PubMed

    de Almeida, Alex Fernando; Tauk-Tornisielo, Sâmia Maria; Carmona, Eleonora Cano

    2013-01-01

    Influences of environmental variables and emulsifiers on lipase production of a Candida viswanathii strain were investigated. The highest lipase activity (101.1 U) was observed at 210 rpm, pH 6.0, and 27.5°C. Other fermentation parameters analyzed showed considerable rates of biomass yield (Y L/S = 1.381 g/g), lipase yield (Y L/S = 6.892 U/g), and biomass productivity (P X = 0.282 g/h). Addition of soybean lecithin increased lipase production in 1.45-fold, presenting lipase yield (Y L/S ) of 10.061 U/g. Crude lipase presented optimal activity at acid pH of 3.5, suggesting a new lipolytic enzyme for this genus and yeast in general. In addition, crude lipase presented high stability in acid conditions and temperature between 40 and 45°C, after 24 h of incubation in these temperatures. Lipase remained active in the presence of organic solvents maintaining above 80% activity in DMSO, methanol, acetonitrile, ethanol, acetone, 1-propanol, isopropanol, and 2-propanol. Effectiveness for the hydrolysis of a wide range of natural triglycerides suggests that this new acid lipase has high potential application in the oleochemical and food industries for hydrolysis and/or modification of triacylglycerols to improve the nutritional properties.

  14. Multi-dimensional gas chromatography with a planar microfluidic device for the characterization of volatile oxygenated organic compounds.

    PubMed

    Luong, J; Gras, R; Cortes, H; Shellie, R A

    2012-09-14

    Oxygenated compounds like methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, acetaldehyde, crotonaldehyde, ethylene oxide, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, and 2-chloromethyl-1,3-dioxolane are commonly encountered in industrial manufacturing processes. Despite the availability of a variety of column stationary phases for chromatographic separation, it is difficult to separate these solutes from their respective matrices using single dimension gas chromatography. Implemented with a planar microfluidic device, conventional two-dimensional gas chromatography and the employment of chromatographic columns using dissimilar separation mechanisms like that of a selective wall-coated open tubular column and an ionic sorbent column have been successfully applied to resolve twelve industrially significant volatile oxygenated compounds in both gas and aqueous matrices. A Large Volume Gas Injection System (LVGIS) was also employed for sample introduction to enhance system automation and precision. By successfully integrating these concepts, in addition to having the capability to separate all twelve components in one single analysis, features associated with multi-dimensional gas chromatography like dual retention time capability, and the ability to quarantine undesired chromatographic contaminants or matrix components in the first dimension column to enhance overall system cleanliness were realized. With this technique, a complete separation for all the compounds mentioned can be carried out in less than 15 min. The compounds cited can be analyzed over a range of 250 ppm (v/v) to 100 ppm (v/v) with a relative standard deviation of less than 5% (n=20) with high degree of reliability.

  15. The Amino Acid Specificity for Activation of Phenylalanine Hydroxylase Matches the Specificity for Stabilization of Regulatory Domain Dimers

    PubMed Central

    2016-01-01

    Liver phenylalanine hydroxylase is allosterically activated by phenylalanine. The structural changes that accompany activation have not been identified, but recent studies of the effects of phenylalanine on the isolated regulatory domain of the enzyme support a model in which phenylalanine binding promotes regulatory domain dimerization. Such a model predicts that compounds that stabilize the regulatory domain dimer will also activate the enzyme. Nuclear magnetic resonance spectroscopy and analytical ultracentrifugation were used to determine the ability of different amino acids and phenylalanine analogues to stabilize the regulatory domain dimer. The abilities of these compounds to activate the enzyme were analyzed by measuring their effects on the fluorescence change that accompanies activation and on the activity directly. At concentrations of 10–50 mM, d-phenylalanine, l-methionine, l-norleucine, and (S)-2-amino-3-phenyl-1-propanol were able to activate the enzyme to the same extent as 1 mM l-phenylalanine. Lower levels of activation were seen with l-4-aminophenylalanine, l-leucine, l-isoleucine, and 3-phenylpropionate. The ability of these compounds to stabilize the regulatory domain dimer agreed with their ability to activate the enzyme. These results support a model in which allosteric activation of phenylalanine hydroxylase is linked to dimerization of regulatory domains. PMID:26252467

  16. Acrylate ester-based monolithic columns for capillary electrochromatography separation of triacylglycerols in vegetable oils.

    PubMed

    Lerma-García, M J; Vergara-Barberán, M; Herrero-Martínez, J M; Simó-Alfonso, E F

    2011-10-21

    A simple and reliable method for the evaluation of triacylglycerols (TAGs) in vegetable oils by capillary electrochromatography (CEC) with UV-Vis detection, using octadecyl acrylate (ODA) ester-based monolithic columns, has been developed. The percentages of the porogenic solvents in the polymerization mixture, and the mobile phase composition, were optimized. The optimum monolith was obtained at the following ratios: 40:60% (wt/wt) monomers/porogens, 60:40% (wt/wt) ODA/1,3-butanediol diacrylate and 23:77% (wt/wt) 1,4-butanediol/1-propanol (14 wt% 1,4-butanediol in the polymerization mixture). A satisfactory resolution between TAGs was achieved in less than 12 min with a 65:35 (v/v) acetonitrile/2-propanol mixture containing 5 mM ammonium acetate. The method was applied to the analysis of TAGs of vegetable oil samples. Using linear discriminant analysis of the CEC TAG profiles, the vegetable oils belonging to six different botanical origins (corn, extra virgin olive, hazelnut, peanut, soybean and sunflower) were correctly classified with an excellent resolution among all the categories.

  17. Toxicity in relation to mode of action for the nematode Caenorhabditis elegans: Acute-to-chronic ratios and quantitative structure-activity relationships.

    PubMed

    Ristau, Kai; Akgül, Yeliz; Bartel, Anna Sophie; Fremming, Jana; Müller, Marie-Theres; Reiher, Luise; Stapela, Frederike; Splett, Jan-Paul; Spann, Nicole

    2015-10-01

    Acute-to-chronic ratios (ACRs) and quantitative structure-activity relationships (QSARs) are of particular interest in chemical risk assessment. Previous studies focusing on the relationship between the size or variation of ACRs to substance classes and QSAR models were often based on data for standard test organisms, such as daphnids and fish. In the present study, acute and chronic toxicity tests were performed with the nematode Caenorhabditis elegans for a total of 11 chemicals covering 3 substance classes (nonpolar narcotics: 1-propanol, ethanol, methanol, 2-butoxyethanol; metals: copper, cadmium, zinc; and carbamates: methomyl, oxamyl, aldicarb, dioxacarb). The ACRs were variable, especially for the carbamates and metals, although there was a trend toward small and less variable ACRs for nonpolar narcotic substances. The octanol-water partition coefficient was a good predictor for explaining acute and chronic toxicity of nonpolar narcotic substances to C. elegans, but not for carbamates. Metal toxicity could be related to the covalent index χm2r. Overall, the results support earlier results from ACR and QSAR studies with standard freshwater test animals. As such C. elegans as a representative of small soil/sediment invertebrates would probably be protected by risk assessment strategies already in use. To increase the predictive power of ACRs and QSARs, further research should be expanded to other species and compounds and should also consider the target sites and toxicokinetics of chemicals.

  18. Monte Carlo Simulation Methods for Computing Liquid-Vapor Saturation Properties of Model Systems.

    PubMed

    Rane, Kaustubh S; Murali, Sabharish; Errington, Jeffrey R

    2013-06-11

    We discuss molecular simulation methods for computing the phase coexistence properties of complex molecules. The strategies that we pursue are histogram-based approaches in which thermodynamic properties are related to relevant probability distributions. We first outline grand canonical and isothermal-isobaric methods for directly locating a saturation point at a given temperature. In the former case, we show how reservoir and growth expanded ensemble techniques can be used to facilitate the creation and insertion of complex molecules within a grand canonical simulation. We next focus on grand canonical and isothermal-isobaric temperature expanded ensemble techniques that provide a means to trace saturation lines over a wide range of temperatures. To demonstrate the utility of the strategies introduced here, we present phase coexistence data for a series of molecules, including n-octane, cyclohexane, water, 1-propanol, squalane, and pyrene. Overall, we find the direct grand canonical approach to be the most effective means to directly locate a coexistence point at a given temperature and the isothermal-isobaric temperature expanded ensemble scheme to provide the most effective means to follow a saturation curve to low temperature.

  19. Higher-alcohols biorefinery: improvement of catalyst for ethanol conversion.

    PubMed

    Olson, Edwin S; Sharma, Ramesh K; Aulich, Ted R

    2004-01-01

    The concept of a biorefinery for higher-alcohol production is to integrate ethanol and methanol formation via fermentation and biomass gasification, respectively, with conversion of these simple alcohol intermediates into higher alcohols via the Guerbet reaction. 1-Butanol results from the self-condensation of ethanol in this multistep reaction occurring on a single catalytic bed. Combining methanol with ethanol gives a mixture of propanol, isobutanol, and 2-methyl-1-butanol. All of these higher alcohols are useful as solvents, chemical intermediates, and fuel additives and, consequently, have higher market values than the simple alcohol intermediates. Several new catalysts for the condensation of ethanol and alcohol mixtures to higher alcohols were designed and tested under a variety of conditions. Reactions of methanol-ethanol mixtures gave as high as 100% conversion of the ethanol to form high yields of isobutanol with smaller amounts of 1-propanol, the amounts in the mixture depending on the starting mixture. The most successful catalysts are multifunctional with basic and hydrogen transfer components.

  20. Enzymes extracted from apple peels have activity in reducing higher alcohols in Chinese liquors.

    PubMed

    Han, Qi'an; Shi, Junling; Zhu, Jing; Lv, Hongliang; Du, Shuangkui

    2014-10-01

    As the unavoidable byproducts of alcoholic fermentation, higher alcohols are unhealthy compounds widespread in alcoholic drinks. To investigate the activity of apple crude enzymes toward higher alcohols in liquors, five kinds of apple peels, namely, Fuji, Gala, Golden Delicious, Red Star, and Jonagold, were chosen to prepare enzymes, and three kinds of Chinese liquors, namely, Xifeng (containing 45% ethanol), Taibai (containing 50% ethanol), and Erguotou (containing 56% ethanol), were tested. Enzymes were prepared in the forms of liquid solution, powder, and immobilized enzymes using sodium alginate (SA) and chitosan. The treatment was carried out at 37 °C for 1 h. The relative amounts of different alcohols (including ethanol, 1-propanol, isobutanol, 1-butanol, isoamylol, and 1-hexanol) were measured using gas chromatography (GC). Conditions for preparing SA-immobilized Fuji enzymes (SA-IEP) were optimized, and the obtained SA-IEP (containing 0.3 g of enzyme) was continuously used to treat Xifeng liquor eight times, 20 mL per time. Significant degradation rates (DRs) of higher alcohols were observed at different degrees, and it also showed enzyme specificity according to the apple varieties and enzyme preparations. After five repeated treatments, the DRs of the optimized Fuji SA-IEP remained 70% for 1-hexanol and >15% for other higher alcohols.

  1. Aminiphilus circumscriptus gen. nov., sp. nov., an anaerobic amino-acid-degrading bacterium from an upflow anaerobic sludge reactor.

    PubMed

    Díaz, C; Baena, S; Fardeau, M-L; Patel, B K C

    2007-08-01

    Strain ILE-2(T) was isolated from an upflow anaerobic sludge bed reactor treating brewery wastewater. The motile, non-sporulating, slightly curved cells (2-4 x 0.1 microm) stained Gram-negative and grew optimally at 42 degrees C and pH 7.1 with 0.5 % NaCl. The strain required yeast extract for growth and fermented Casamino acids, peptone, isoleucine, arginine, lysine, alanine, valine, glutamate, histidine, glutamine, methionine, malate, fumarate, glycerol and pyruvate to acetate, propionate and minor amounts of branched-chain fatty acids. Carbohydrates, formate, acetate, propionate, butyrate, isovalerate, methanol, ethanol, 1-propanol, butanol, lactate, succinate, starch, casein, gelatin, xylan and a number of other amino acids were not utilized. The DNA G+C content of strain ILE-2(T) was 52.7 mol%. 16S rRNA gene sequence analysis revealed that ILE-2(T) was distantly related to members of the genera Aminobacterium (83 % similarity) and Aminomonas (85 % similarity) in the family Syntrophomonadaceae, order Clostridiales, phylum Firmicutes. On the basis of the results of our polyphasic analysis, strain ILE-2(T) represents a novel species and genus within the family Syntrophomonadaceae, for which the name Aminiphilus circumscriptus gen. nov., sp. nov. is proposed. The type strain of Aminiphilus circumscriptus is ILE-2(T) (=DSM 16581(T) =JCM 14039(T)).

  2. A rapid and sensitive alcohol oxidase/catalase conductometric biosensor for alcohol determination.

    PubMed

    Hnaien, M; Lagarde, F; Jaffrezic-Renault, N

    2010-04-15

    A new conductometric biosensor has been developed for the determination of short chain primary aliphatic alcohols. The biosensor assembly was prepared through immobilization of alcohol oxidase from Hansenula sp. and bovine liver catalase in a photoreticulated poly(vinyl alcohol) membrane at the surface of interdigitated microelectrodes. The local conductivity increased rapidly after alcohol addition, reaching steady-state within 10 min. The sensitivity was maximal for methanol (0.394+/-0.004 microS microM(-1), n=5) and decreased by increasing the alcohol chain length. The response was linear up to 75 microM for methanol, 70 microM for ethanol and 65 microM for 1-propanol and limits of detection were 0.5 microM, 1 microM and 3 microM, respectively (S/N=3). No significant loss of the enzyme activities was observed after 3 months of storage at 4 degrees C in a 20mM phosphate buffer solution pH 7.2 (two or three measurements per week). After 4 months, 95% of the initial signal still remained. The biosensor response to ethanol was not significantly affected by acetic, lactic, ascorbic, malic, oxalic, citric, tartaric acids or glucose. The bi-enzymatic sensor was successfully applied to the determination of ethanol in different alcoholic beverages. PMID:20188912

  3. Bismuth Dimercaptopropanol (BisBAL) Inhibits the Expression of Extracellular Polysaccharides and Proteins by Brevundimonas diminuta: Implications for Membrane Microfiltration

    SciTech Connect

    Badireddy, Appala R.; Chellam, Shankararaman; Yanina, Svetlana; Gassman, Paul L.; Rosso, Kevin M.

    2008-02-15

    A 2:1 molar ratio preparation of bismuth with a lipophilic dithiol (3-dimercapto-1-propanol, BAL)significantly reduced extracellular polymeric substances (EPS) expression by Brevundimonas diminuta in suspended cultures at levels just below the minimum inhibitory concentration (MIC). Total polysaccharides and proteins secreted by B. diminuta decreased by approximately 95% over a 5-day period when exposed to the bismuth-BAL chelate (BisBAL) at near MIC (12 μM). Fourier-transform infrared spectroscopy (FTIR) suggested that a possible mechanism of biofilm disruption by BisBAL is the inhibition of carbohydrate Oacetylation. FTIR also revealed extensive homology between EPS samples with and without BisBAL treatment, with proteins, polysaccharides, and peptides varying predominantly only in the amount expressed. EPS secretion decreased following BisBAL treatment as verified by atomic force microscopy and scanning electron microscopy. Without BisBAL treatment, a slime-like EPS matrix secreted by B. diminuta resulted in biofouling and inefficient hydrodynamic backwashing of microfiltration membranes.

  4. Mobilization of lead by esters of meso-2,3-dimercaptosuccinic acid

    SciTech Connect

    Singh, P.K.; Jones, M.M.; Xu, Z.; Gale, G.R.; Smith, A.B.; Atkins, L.M. )

    1989-01-01

    An examination was made of the relative efficacies of 2,3-dimercapto-1-propanol (BAL) and three diesters (CH(SH)COOR)2; DMDMS, R = CH3; DEDMS, R = C2H5; and Di-PDMS, R = CH(CH3)2 of meso-2,3-dimercaptosuccinic acid (DMSA) in mobilizing freshly injected lead from mice. These diesters, like BAL, reduced the lead levels resulting from freshly injected lead in both the soft tissues (liver, kidneys, spleen, and brain) and the bone (tibia). After treatment with the dimethyl (DMDMS), the diethyl (DEDMS), and the diisopropyl (Di-PDMS) esters the lead content of each of the organs was significantly less than that present in the untreated controls. Each of the diesters reduced lead levels in the kidneys, liver, and spleen significantly below those levels found after BAL treatment. The action of the diesters in reducing brain lead levels was comparable to that of BAL. Di-PDMS was the most effective of these compounds and was significantly superior to BAL. Each of the esters was also significantly more effective than BAL in reducing the whole body level of lead.

  5. Using the Griess colorimetric nitrite assay for measuring aliphatic β-nitroalcohols

    PubMed Central

    Wen, Quan; Paik, David C.

    2012-01-01

    Our recent studies suggest that aliphatic β-nitroalcohols (BNAs) may represent a useful class of compounds for topical therapeutic corneoscleral cross-linking agents. Thus, this study was undertaken in order to standardize a simple method for nitroalcohol quantitation based on a denitration step followed by colorimetric Griess nitrite assay. Conditions necessary for denitration included a pH of 7-9 and heating for 1 hour at 100°C. Standard curves for two mono-nitroalcohols (2-nitroethanol and 2-nitro-1-propanol), a nitro-diol (2-methyl-2-nitro-1,3-propanediol), and a nitro-triol (2-hydroxymethyl-2-nitro-1,3-propanediol) showed excellent linearity in the 100-500 M range with absorbance values <1.0 and R2 values >0.98. The lower limit of detection was ~20 M. Recovery from tissue homogenates (10mg/mL wet weight) of rabbit cornea and sclera as well as solutions of gelatin B (1mg/mL) ranged from 89-103% for scleral tissue, 68-106% for corneal tissue, and 90-99% for gelatin B. The Griess colorimetric nitrite assay can be successfully used for the quantitative determination of BNAs and is simpler to use than conventional chromatographic techniques. PMID:22406005

  6. Voltammetric determination of ruthenium in the form of complexes with biologically active ligands

    SciTech Connect

    Medyantseva, E.P.; Budnikov, G.K.; Balakaeva, T.A.

    1992-02-10

    The interest in the analytical chemistry of ruthenium and its compounds has recently been increasing. Ruthenium compounds can be used an antitumor agents and in the treatment of tuberculosis and fungal infections. It has been suggested that there is a specific relationship between the reduction potentials of the compounds and their biological activity. Of greatest interest among the biologically active compounds are the compounds with nitrogen-containing heterocycles. In order to obtain information on the degree of oxidation of the central atom in the complexes and to select the optimum conditions for the determination of the mono- and bi-nuclear complexes of ruthenium compounds with biologically active ligands such as imidazole (Im), histidine (His), benzimidazole (BIm) and its methyl derivative [1,2(CH{sub 3}){sub 2} - BIm], benzohyroxamic acid (Bha), and 1-phenyl-2-methylamino-1-propanol or ephedrine (Eph) in the present work, the authors studied their electrochemical behavior at dropping mercury (dme) and a platinum electrodes. 6 refs., 1 fig., 2 tabs.

  7. Characterizing Olfactory Perceptual Similarity Using Carbon Chain Discrimination in Fischer 344 Rats

    PubMed Central

    2014-01-01

    Performance on olfactory tests can be influenced by a number of stimulus characteristics including chemical structure, concentration, perceptual similarity, and previous experience with the test odorants. Few of these parameters have been extensively characterized in the Fischer 344 rat strain. To investigate how odor quality affects perception in this rat strain, we measured how graded perceptual similarity, created by varying carbon chain length across a series of homologous alcohol pairs, influenced odor discrimination using a liquid-motivated go/no-go task. We employed an automated, liquid-dilution olfactometer to train Fischer 344 rats (N = 8) on a 2-odor discrimination task. Six odorants (1-propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol) were arranged to produce 15 novel odorant pairs differing between 1 and 5 carbon atoms; testing sessions included presentation of only 1 pseudorandomly assigned pair daily (200 trials). Results show that although rats can learn to discriminate between any 2 odorant pairs, performance declines systematically as the pairs become more structurally similar and, therefore, more perceptually confusing. As such, the easier discrimination pairs produced reliable ceiling effects across all rats, whereas performance for the difficult discrimination pairs was consistently worse, even after repeated testing. These data emphasize the importance of considering odorant stimulus dimensions in experimental designs employing olfactory stimuli. Moreover, establishing baseline olfactory performance in Fischer 344 rats may be particularly useful for predicting age-related cognitive decline in this model. PMID:24488965

  8. Experimental Measurement and Thermodynamic Modeling of the Solubility of Carbon Dioxide in Aqueous Alkanolamine Solutions in the High Gas Loading Region

    NASA Astrophysics Data System (ADS)

    Suleman, Humbul; Maulud, Abdulhalim Shah; Man, Zakaria

    2016-09-01

    The solubility of carbon dioxide in aqueous alkanolamine solutions was investigated in the high gas loading region based on experimental measurements and thermodynamic modeling. An experimental phase equilibrium study was performed to evaluate the absorption of carbon dioxide in aqueous solutions of five representative alkanolamines, including monoethanolamine, diethanolamine, N-methyldiethanolamine, 2-amino-2-methyl-1-propanol and piperazine. The carbon dioxide loadings of these solutions were determined for a wide range of pressures (62.5 kPa to 4150 kPa), temperatures (303.15 K to 343.15 K) and alkanolamine concentrations (2 M to 4 M). The results were found to be largely consistent with those previously reported in the literature. Furthermore, a hybrid Kent-Eisenberg model was developed for the correlation of the experimental data points. This new model incorporated an equation of state/excess Gibbs energy model for determining the solubility of carbon dioxide in the high-pressure-high gas loading region. This approach also used a single correction parameter, which was a function of the alkanolamine concentration. The results of this model were in excellent agreement with our experimental results. Most notably, this model was consistent with other reported values from the literature.

  9. Electron spin lattice relaxation of nitroxyl radicals in temperature ranges that span glassy solutions to low-viscosity liquids

    NASA Astrophysics Data System (ADS)

    Sato, Hideo; Bottle, Steven E.; Blinco, James P.; Micallef, Aaron S.; Eaton, Gareth R.; Eaton, Sandra S.

    2008-03-01

    Electron spin-lattice relaxation rates, 1/ T1, at X-band of nitroxyl radicals (4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl, 3-carbamoyl-2,2,5,5-tetramethylpyrrolidin-1-oxyl and 3-carbamoyl-2,2,5,5-tetramethylpyrrolin-1-oxyl) in glass-forming solvents (decalin, glycerol, 3-methylpentane, o-terphenyl, 1-propanol, sorbitol, sucrose octaacetate, and 1:1 water:glycerol) at temperatures between 100 and 300 K were measured by long-pulse saturation recovery to investigate the relaxation processes in slow-to-fast tumbling regimes. A subset of samples was also studied at lower temperatures or at Q-band. Tumbling correlation times were calculated from continuous wave lineshapes. Temperature dependence and isotope substitution ( 2H and 15N) were used to distinguish the contributions of various processes. Below about 100 K relaxation is dominated by the Raman process. At higher temperatures, but below the glass transition temperature, a local mode process makes significant contributions. Above the glass transition temperature, increased rates of molecular tumbling modulate nuclear hyperfine and g anisotropy. The contribution from spin rotation is very small. Relaxation rates at X-band and Q-band are similar. The dependence of 1/ T1 on tumbling correlation times fits better with the Cole-Davidson spectral density function than with the Bloembergen-Purcell-Pound model.

  10. Universal critical-like scaling of dynamic properties in symmetry-selected glass formers

    NASA Astrophysics Data System (ADS)

    Drozd-Rzoska, Aleksandra; Rzoska, Sylwester J.; Paluch, Marian

    2008-11-01

    Evidence for a possible general validity of the critical-like behavior of dielectric relaxation time or viscosity τ,η∝(T-TC)-ϕ with ϕ →9 and TC1-propanol). Results presented explain the puzzling experimental artifacts supporting the dynamical scaling model [R. H. Colby, Phys. Rev. E 61, 1783 (2000); B. M. Erwin, R. H. Colby, J. Non-Cryst. Solids 307-310, 225 (2002)]. It is suggested that spin-glass-like systems may be linked to the discussed pattern.

  11. HS-SPME GC/MS characterization of volatiles in raw and dry-roasted almonds (Prunus dulcis).

    PubMed

    Xiao, Lu; Lee, Jihyun; Zhang, Gong; Ebeler, Susan E; Wickramasinghe, Niramani; Seiber, James; Mitchell, Alyson E

    2014-05-15

    A robust HS-SPME and GC/MS method was developed for analyzing the composition of volatiles in raw and dry-roasted almonds. Almonds were analyzed directly as ground almonds extracted at room temperature. In total, 58 volatiles were identified in raw and roasted almonds. Straight chain aldehydes and alcohols demonstrated significant but minimal increases, while the levels of branch-chain aldehydes, alcohols, heterocyclic and sulfur containing compounds increased significantly (500-fold) in response to roasting (p<0.05). Benzaldehyde decreased from 2934.6±272.5 ng/g (raw almonds) to 315.8±70.0 ng/g (averaged across the roasting treatments evaluated i.e. 28, 33 and 38 min at 138 °C) after roasting. Pyrazines were detected in only the roasted almonds, with the exception of 2,5-dimethylpyrazine, which was also found in raw almonds. The concentration of most alcohols increased in the roasted samples with the exception of 2-methyl-1-propanol, 3-methyl-1-butanol and 2-phenylethyl alcohol, which decreased 68%, 80%, and 86%, respectively.

  12. A Pseudomonas putida Strain Genetically Engineered for 1,2,3-Trichloropropane Bioremediation

    PubMed Central

    Samin, Ghufrana; Pavlova, Martina; Arif, M. Irfan; Postema, Christiaan P.; Damborsky, Jiri

    2014-01-01

    1,2,3-Trichloropropane (TCP) is a toxic compound that is recalcitrant to biodegradation in the environment. Attempts to isolate TCP-degrading organisms using enrichment cultivation have failed. A potential biodegradation pathway starts with hydrolytic dehalogenation to 2,3-dichloro-1-propanol (DCP), followed by oxidative metabolism. To obtain a practically applicable TCP-degrading organism, we introduced an engineered haloalkane dehalogenase with improved TCP degradation activity into the DCP-degrading bacterium Pseudomonas putida MC4. For this purpose, the dehalogenase gene (dhaA31) was cloned behind the constitutive dhlA promoter and was introduced into the genome of strain MC4 using a transposon delivery system. The transposon-located antibiotic resistance marker was subsequently removed using a resolvase step. Growth of the resulting engineered bacterium, P. putida MC4-5222, on TCP was indeed observed, and all organic chlorine was released as chloride. A packed-bed reactor with immobilized cells of strain MC4-5222 degraded >95% of influent TCP (0.33 mM) under continuous-flow conditions, with stoichiometric release of inorganic chloride. The results demonstrate the successful use of a laboratory-evolved dehalogenase and genetic engineering to produce an effective, plasmid-free, and stable whole-cell biocatalyst for the aerobic bioremediation of a recalcitrant chlorinated hydrocarbon. PMID:24973068

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

    PubMed

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

    2013-07-01

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

  14. Photocatalytic degradation of Reactive Black 5 and Malachite Green with ZnO and lanthanum doped nanoparticles

    NASA Astrophysics Data System (ADS)

    Kaneva, N.; Bojinova, A.; Papazova, K.

    2016-02-01

    Here we report the preparation of ZnO particles with different concentrations of La3+ doping (0, 0.5 and 1 wt%) via sol-gel method. The nanoparticles are synthesized directly from Zn(CH3COO)2.2H2O in the presence of 1-propanol and triethylamine at 80°C. The conditions are optimized to obtain particles of uniform size, easy to isolate and purify. The nanoparticles are characterized by SEM, XRD and UV-Vis analysis. The photocatalytic properties of pure and La-doped ZnO are studied in the photobleaching of Malachite Green (MG) and Reactive Black 5 (RB5) dyes in aqueous solutions upon UV illumination. It is observed that the rate constant increases with the La loading up to 1 wt%. The doping helps to achieve complete mineralization of MG within a short irradiation time. 1 wt% La-doped ZnO nanoparticles show highest photocatalytic activity. The La3+ doped ZnO particles degrade faster RB5 than MG. The reason is weaker N=N bond in comparison with the C-C bond between the central carbon atom and N,N-dimethylaminobenzyl in MG. The as-prepared ZnO particles can find practical application in photocatalytic purification of textile wastewaters.

  15. Antimicrobial evaluation of selected naturally occurring oxyprenylated secondary metabolites.

    PubMed

    Di Giulio, Mara; Genovese, Salvatore; Fiorito, Serena; Epifano, Francesco; Nostro, Antonia; Cellini, Luigina

    2016-08-01

    This study tested the antimicrobial activity of eight selected naturally occurring oxyprenylated secondary metabolites against Staphylococcus aureus ATCC 29213, S. epidermidis ATCC 35984, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 9027 and Candida albicans ATCC 10231. Results showed a moderate antimicrobial activity. The most active compounds were 3-(4-geranyloxyphenyl)-1-ethanol (4) and 3-(4-isopentenyloxyphenyl)-1-propanol (5) that were tested on mature and in-formation biofilms of all micro-organisms, moreover the cytotoxic activity was evaluated. Except for S. epidermidis, both compounds reduced significantly (p < 0.05) the microbial biofilm formation at 1/2 MIC and 1/4 MIC, in particular, compounds 4 and 5 at each concentration, inhibited E. coli biofilm formation to a greater extent, the biofilm formation was never more than 44% in respect to the control, moreover both compounds showed a low cytotoxic effect. Oxyprenylated derivatives may be of great interest for the development of novel antimicrobial therapeutic strategies and the synthesis of semi-synthetic analogues with anti-biofilm efficacy. PMID:27498831

  16. Choline Essentiality and Its Requirement in Diets for Juvenile Parrot Fish (Oplegnathus fasciatus)

    PubMed Central

    Khosravi, Sanaz; Jang, Ji-Woong; Rahimnejad, Samad; Song, Jin-Woo; Lee, Kyeong-Jun

    2015-01-01

    A 12-wk feeding trial was conducted to evaluate the essentiality of choline supplementation in diets for parrot fish. Five isonitrogenous and isocaloric diets were supplemented with 0 (as control), 500, 1,000, and 2,000 mg choline per kg diet, and a positive control diet without choline contained 0.3% of 2-amino-2-methyl-1-propanol as choline biosynthesis inhibitor (designated as Con, C500, C1000, C2000 and Con+, respectively). Triplicate groups of fish (body weight, 8.8±0.01 g) were fed one of the experimental diets at a rate of 4% body weight twice daily. The fish fed Con+ diet revealed significantly lower growth performance and feed utilization efficiency than other fish groups. Supplementation of choline to the basal diet did not significantly influence fish growth. The highest liver lipid content was observed in fish fed the Con+ diet and inversely correlated with liver choline concentration although the differences were not significant. Also, significantly higher liver linoleic, eicosapentaenoic and docosahexaenoic acid contents were found in fish fed the Con+ diet. Innate immune parameters including respiratory burst and myeloperoxidase activities were not significantly affected by dietary choline levels. The findings in this study conclude that choline concentration of approximately 230 mg kg−1 diet meets the requirement of parrot fish. PMID:25924958

  17. Suitability of Macrolampis firefly and Pyrearinus click beetle luciferases for bacterial light off toxicity biosensor.

    PubMed

    Gabriel, Gabriele V M; Lopes, P S; Viviani, V R

    2014-01-15

    Bioluminescence is widely used in biosensors. For water toxicity analysis, the naturally bioluminescent bacteria Vibrio fischeri have been used extensively. We investigated the suitability of two new beetle luciferases for Escherichia coli light off biosensors: Macrolampis firefly and Pyrearinus termitilluminans click beetle luciferases. The bioluminescence detection assay using this system is very sensitive, being comparable or superior to V. fischeri. The luciferase of P. termitilluminans produces a strong and sustained bioluminescence that is useful for less sensitive and inexpensive assays that require integration of the emission, whereas Macrolampis luciferase displays a flash-like luminescence that is useful for fast and more sensitive assays. The effect of heavy metals and sanitizing agents was analyzed. Zinc, copper, 1-propanol, and iodide had inhibitory effects on bioluminescence and growth assays; however, in these cases the bioluminescence was not a very reliable indicator of cell growth and metabolic activity because these agents also inhibited the luciferase. On the other hand, mercury and silver strongly affected cell bioluminescence and growth but not the luciferase activity, indicating that bioluminescence was a reliable indicator of cell growth and metabolic activity in this case. Finally, bioluminescent E. coli immobilized in agarose matrix gave a more stable format for environmental assays.

  18. Impact of alcohols on the formation and stability of protein-stabilized nanoemulsions.

    PubMed

    Zeeb, Benjamin; Herz, Eva; McClements, David Julian; Weiss, Jochen

    2014-11-01

    Nanoemulsions are increasingly being used for encapsulation, protection, and delivery of bioactive lipids, however, their formation from natural emulsifiers is still challenging. We investigated the impact of alcohol on the formation and stability of protein-stabilized oil-in-water nanoemulsions prepared by high-pressure homogenization. The influence of different alcohols (ethanol, 1-propanol, and 1-butanol) at various concentrations (0-25% w/w) on the formation and stability of emulsions stabilized by sodium caseinate, whey protein isolate, and fish gelatin was investigated. The mean particle diameter decreased with increasing alcohol concentrations from 0 to 10%w/w, but extensive droplet aggregation occurred at higher levels. This phenomenon was attributed to enhanced protein-protein interactions between the adsorbed emulsifier molecules in the presence of alcohol leading to droplet flocculation. The smallest droplets (d<100nm) were obtained when 10%w/w 1-butanol was added to sodium caseinate-stabilized nanoemulsions, but relatively small droplets (d<150nm) could also be obtained in the presence of a food-grade alcohol (ethanol). This study demonstrated that alcohol addition might be a useful tool for producing protein-stabilized nanoemulsions suitable for use as delivery systems of lipophilic bioactive agents. PMID:25129338

  19. Effects of polar and nonpolar groups on the solubility of organic compounds in soil organic matter

    USGS Publications Warehouse

    Chiou, C.T.; Kile, D.E.

    1994-01-01

    Vapor sorption capacities on a high-organic-content peat, a model for soil organic matter (SOM), were determined at room temperature for the following liquids: n-hexane, 1,4-dioxane, nitroethane, acetone, acetonitrile, 1-propanol, ethanol, and methanol. The linear organic vapor sorption is in keeping with the dominance of vapor partition in peat SOM. These data and similar results of carbon tetrachloride (CT), trichloroethylene (TCE), benzene, ethylene glycol monoethyl ether (EGME), and water on the same peat from earlier studies are used to evaluate the effect of polarity on the vapor partition in SOM. The extrapolated liquid solubility from the vapor isotherm increases sharply from 3-6 wt % for low-polarity liquids (hexane, CT, and benzene) to 62 wt % for polar methanol and correlates positively with the liquid's component solubility parameters for polar interaction (??P) and hydrogen bonding (??h). The same polarity effect may be expected to influence the relative solubilities of a variety of contaminants in SOM and, therefore, the relative deviations between the SOM-water partition coefficients (Kom) and corresponding octanol-water partition coefficients (Kow) for different classes of compounds. The large solubility disparity in SOM between polar and nonpolar solutes suggests that the accurate prediction of Kom from Kow or Sw (solute water solubility) would be limited to compounds of similar polarity.

  20. Photoisomerization mechanism of 1,1'-dimethyl-2,2'-pyridocyanine in the gas phase and in solution.

    PubMed

    Gao, Aihua; Zhang, Peiyu; Zhao, Meiyu; Liu, Jianyong

    2015-02-01

    The trans→cis and cis→trans photoisomerization mechanisms of 1,1'-dimethyl-2,2'-pyridocyanine have been investigated theoretically in the gas phase and in methanol. Two-dimensional potential energy surfaces were computed for the ground and first excited singlet states of the isolated molecule using complete active space self-consistent field method. Our computations suggest that the torsion around the central C-C bonds with carbon-out-of-plane motion is the preferred photoisomerization mechanism. In the gas phase, conical intersections were found near the minima of excited state. The excited-state decay follows a barrierless minimum-energy pathway before the molecule moves to the excited-state global minimum (minS1) and the system relaxes to the ground state through a conical intersection. In methanol, the system would first reach a stationary structure of C2 symmetry after the trans form is electronically excited. Solvent polarity effects were investigated in chloroform, dichloromethane, 1-propanol, ethanol, methanol, and water. There is a significant barrier between the stationary structure of C2 symmetry and minS1 in the excited state in high polarity solvents. Thus, Me-1122P has a much longer lifetime of the excited state in solvents of high polarity. PMID:25456657

  1. Use of micellar liquid chromatography to analyze oxolinic acid, flumequine, marbofloxacin and enrofloxacin in honey and validation according to the 2002/657/EC decision.

    PubMed

    Tayeb-Cherif, K; Peris-Vicente, J; Carda-Broch, S; Esteve-Romero, J

    2016-07-01

    A micellar liquid chromatographic method was developed for the analysis of oxolinic acid, flumequine, marbofloxacin and enrofloxacin in honey. These quinolines are unethically used in beekeeping, and a zero-tolerance policy to antibiotic residues in honey has been stated by the European Union. The sample pretreatment was a 1:1 dilution with a 0.05M SDS at pH 3 solution, filtration and direct injection, thus avoiding extraction steps. The quinolones were eluted without interferences using mobile phase of 0.05M SDS/12.5% 1-propanol/0.5% triethylamine at pH 3, running at 1mL/min under isocratic room through a C18 column. The analytes were detected by fluorescence. The method was successfully validated according to the requirements of the European Union Decision 2002/657/EC in terms of: specificity, linearity (r(2)>0.995), limit of detection and decision limit (0.008-0.070mg/kg), lower limit of quantification (0.02-0.2mg/kg), detection capability (0.010-0.10mg/kg), recovery (82.1-110.0%), precision (<9.4%), matrix effects, robustness (<10.4%), and stability. The procedure was applied to several commercial honey supplied by a local supermarket, and the studied antibiotics were not detected. Therefore, the method was rapid, simple, safe, eco friendly, reliable and useful for the routine analysis of honey samples.

  2. The Effect of Organic Solvents and Other Parameters on Trypsin-Catalyzed Hydrolysis of Na-Benzoyl-arginine-p-nitroanilide. A Project-Oriented Biochemical Experiment

    NASA Astrophysics Data System (ADS)

    Correia, L. C.; Bocewicz, A. C.; Esteves, S. A.; Pontes, M. G.; Versieux, L. M.; Teixeira, S. M. R.; Santoro, M. M.; Bemquerer, M. P.

    2001-11-01

    The study of enzymatic catalysis is a classical biochemistry experiment for undergraduate classes. We propose the utilization of the serine protease trypsin to discuss several parameters affecting enzyme catalysis. Hydrolysis of the chromogenic substrate Na -benzoyl-arginine-p-nitroanilide (BApNA) was followed by spectrophotometric monitoring. The optimal pH and temperature values were found to be 8.0 and 40 °C, respectively. Km and Vmax values were obtained by adjustment to Michaelis-Menten, Lineweaver-Burke, and Hanes equations. We then investigated the effect of organic solvents (a series of alcohols) on the hydrolysis of the chromogenic substrate. The reaction rate was reduced in the presence of methanol and further reduced by ethanol, 1-propanol, and 2-propanol, when compared to the data obtained with buffer. Finally the students were asked to measure the molar absorptivity of p-nitrophenol in the presence of the alcohols employed for the kinetic experiments. Thus they could learn that the value of this parameter varies with the solvent. These experiments were designed as a project-oriented approach to teach biochemistry methodologies and theoretical aspects of enzyme kinetics. They took about four months with four to six hours per week spent in the laboratory.

  3. Adsorptive separation in bioprocess engineering

    SciTech Connect

    Huang, E.W.Y.

    1987-01-01

    The invention and development of an energy-efficient separation technique for recovery of desired chemicals from biomass conversion would greatly enhance the economic viability of this bioprocess. Adsorptive separation of several chemicals from aqueous solution was studied in this thesis. The desired species were recovered from the dilute aqueous solution by using crosslinked polyvinylpyridine resin to effect selective sorption. The sorbed chemicals were then removed from the resin by either thermal regeneration or elution with some appropriate desorbents. The effects of temperature, pH value, and solute concentration on resin swelling were investigated. The adsorption equilibrium isotherms, resin capacities and resin selectivities of methanol, ethanol, 1-propanol, isopropanol, glycerol, acetone, 1-butanol, tert-butanol, and 2,3-butanediol were determined to study the homologies. Furthermore, acetic acid, butyric acid, hydrochloric acid, lactic acid, and sulfuric acid were recovered from very dilute aqueous solutions. The concentration of the sorbed chemical in the stationary phase can be many times higher than in the mobile phase for some acids. Finally, different types of equilibrium isotherms were used to fit the experimental data. A mathematical model was developed by using the theory of interference to predict the breakthrough curves and the process efficiency to provide information for large-scale process design and development.

  4. Health assessment for Velsicol Chemical Corporation (St. Louis Plant Site), Gratiot County, Michigan, Region 5. CERCLIS No. MID000722439. Preliminary report

    SciTech Connect

    Not Available

    1989-04-18

    The Velsicol Chemical Corporation (Velsicol) site is currently listed on the National Priorities List. More than 60 contaminants were found throughout the site, but polybrominated biphenyl (PBB) is the contaminant that caused the most concern. Phenols, calcium, magnesium, sodium (as chloride or bromium salts) and PBB were present in wastes. Soil samples collected had the following maximum concentrations (parts per million - ppm); PBB, 1,100; phenol, 4.2; lead, 11,100; hexabromebenzene, 56; 2,3-dibromo-1-propanol phosphate, 4,700; and dimethylaminoethylchloride hydrochloride (DMAE), 53. On-site ground water samples contained the following maximum concentrations (ppm): PBB, 0.013; chloride, 82,000; sulfate, 650; phenol, 1.2; DMAE, 20 and carbon tetrachloride, 0.080. Of various species of fish carp had the highest maximum PBB concentrations. Wildlife (mice, earthworms, a raccoon and ducks) in the area were found to be contaminated with PBB and/or DDT. The site is of potential public health concern because of the risk to human health that could result from possible human exposure to hazardous substances at levels that may result in adverse human health effects over time. Occupational exposure to many harmful contaminants, including PBB and DDT, has occurred and exposure to the general population may possibly still be occurring via ingestion of contaminated fish and wildlife.

  5. Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

    PubMed

    Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

    2009-05-01

    The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product.

  6. Identification and characterization of stress degradants of lacosamide by LC-MS and ESI-Q-TOF-MS/MS: development and validation of a stability indicating RP-HPLC method.

    PubMed

    Ramisetti, Nageswara Rao; Kuntamukkala, Ramakrishna; Lakshetti, Sridhar; Sripadi, Prabhakar

    2014-07-01

    The current study dealt with the degradation behavior of lacosamide (LAC) under ICH prescribed stress conditions. LAC was found to be labile under acid and base hydrolytic stress conditions, while it was stable to neutral hydrolytic, oxidative, photolytic and thermal stress. In total, seven degradation products (DPs) were formed, which were separated on a C18 column using a stability-indicating method. LC-MS analyses indicated that one of the DPs had the same molecular mass as that of the drug. Structural characterization of DPs was carried out using ESI-Q-TOF-MS/MS technique. The degradation pathways and mechanisms of degradation of the drug were delineated by carrying out the degradation in different co-solvents viz. methanol, deuterated methanol, ethanol, 1-propanol and acetonitrile. The developed LC method was validated for the determination of related substances and assay of LAC as per ICH guidelines. This study demonstrates a comprehensive approach of LAC degradation studies during its development phase. PMID:24699370

  7. Rapid synthesis of propyl caffeate in ionic liquid using a packed bed enzyme microreactor under continuous-flow conditions.

    PubMed

    Wang, Jun; Gu, Shuang-Shuang; Cui, Hong-Sheng; Yang, Liu-Qing; Wu, Xiang-Yang

    2013-12-01

    Propyl caffeate has the highest antioxidant activity among caffeic acid alkyl esters, but its industrial production via enzymatic transesterification in batch reactors is hindered by a long reaction time (24h). To develop a rapid process for the production of propyl caffeate in high yield, a continuous-flow microreactor composed of a two-piece PDMS in a sandwich-like microchannel structure was designed for the transesterification of methyl caffeate and 1-propanol catalyzed by Novozym 435 in [B mim][CF3SO3]. The maximum yield (99.5%) in the microreactor was achieved in a short period of time (2.5h) with a flow rate of 2 μL/min, which kinetic constant Km was 16 times lower than that of a batch reactor. The results indicated that the use of a continuous-flow packed bed enzyme microreactor is an efficient method of producing propyl caffeate with an overall yield of 84.0%. PMID:24128399

  8. On the atmospheric degradation of multifunctional organic compounds by NO3 and SO4- radicals in aqueous solution

    NASA Astrophysics Data System (ADS)

    Schöne, Luisa; Stieger, Bastian; Weller, Christian; Herrmann, Hartmut

    2014-05-01

    The atmospheric decomposition and transformation of a large number of organic compounds is initiated by radicals in the gas and aqueous phase. With increasing degree of oxidation and functionalization, organics become less volatile and more water soluble and partition into aqueous particles and cloud droplets where the oxidation by radicals continues. NO3 and SO4- radicals dominate the atmospheric aqueous phase besides OH radicals. Within this work, temperature dependent kinetic investigations were conducted by use of a laser flash photolysis laser long path absorption (LFPLLPA) setup. Second order rate constants for the reactions of 3-methoxy-1-propanol, diethylether, methylpropylether, 2-methyloxirane-2-carbaldehyde, 2,3-dihydroxy-2-methylpropanal, pyruvic, glyoxylic and glycolic acid as well as glyoxal, methylglyoxal and glycolaldehyde with NO3 and SO4- radicals were measured in a temperature range of 278 and 318 K applying pseudo-first order kinetics. The reactivity of the acids and their anions were investigated separately adjusting the pH to pH 1 or pH 8 for the acid or the anion form, respectively. From these measurements, activation parameters were derived. Measured k2nd range from 106 - 108 M1 s1. The kinetic and thermodynamic parameters as well as reaction mechanisms will be discussed within this contribution.

  9. Photoelectron spectroscopy of liquid water, some alcohols, and pure nonane in free micro jets

    NASA Astrophysics Data System (ADS)

    Faubel, Manfred; Steiner, Björn; Toennies, J. Peter

    1997-06-01

    The recently developed technique of accessing volatile liquids in a high vacuum environment by using a very thin liquid jet is implemented to carry out the first measurements of photoelectron spectra of pure liquid water, methanol, ethanol, 1-propanol, 1-butanol, and benzyl alcohol as well as of liquid n-nonane. The apparatus, which consists of a commercial hemispherical (10 cm mean radius) electron analyzer and a hollow cathode discharge He I light source is described in detail and the problems of the sampling of the photoelectrons in such an environment are discussed. For water and most of the alcohols up to six different electronic bands could be resolved. The spectra of 1-butanol and n-nonane show two weakly discernable peaks from which the threshold ionization potential could be determined. A deconvolution of the photoelectron spectra is used to extract ionization potentials of individual molecular bands of molecules near the surface of the liquid and shifts of the order of 1 eV compared to the gas phase are observed. A molecular orientation for water molecules at the surface of liquid water is inferred from a comparison of the relative band strengths with the gas phase. Similar effects are also observed for some of the alcohols. The results are discussed in terms of a simple "Born-solvation" model.

  10. Diffusion studies of dihydroxybenzene isomers in water-alcohol systems.

    PubMed

    Codling, Dale J; Zheng, Gang; Stait-Gardner, Tim; Yang, Shu; Nilsson, Mathias; Price, William S

    2013-03-01

    Nuclear magnetic resonance diffusion studies can be used to identify different compounds in a mixture. However, because the diffusion coefficient is primarily dependent on the effective hydrodynamic radius, it is particularly difficult to resolve compounds with similar size and structure, such as isomers, on the basis of diffusion. Differential solution interactions between species in certain solutions can afford possibilities for separation. In the present study, the self-diffusion of the three isomers of dihydroxybenzene (i.e., (1,2-) catechol, (1,3-) resorcinol, and (1,4-) hydroquinone) was studied in water, aqueous monohydric alcohols (i.e., ethanol, 1-propanol, tert-butanol), and aqueous ethylene glycol. These systems allowed the effects of isomerism and differential solvent interactions on diffusion to be examined. It was found that, while in aqueous solution these isomers had the same diffusion coefficient, in water-monohydric alcohol systems the diffusion coefficient of catechol differed from those of resorcinol and hydroquinone. The separation was found to increase at higher concentrations of monohydric alcohols. The underlying chemical reasons for these differences were investigated.

  11. Insights into chiral recognition mechanisms in supercritical fluid chromatography V. Effect of the nature and proportion of alcohol mobile phase modifier with amylose and cellulose tris-(3,5-dimethylphenylcarbamate) stationary phases.

    PubMed

    Khater, Syame; West, Caroline

    2014-12-19

    In enantioselective supercritical fluid chromatography (SFC) with chiral stationary phases (CSP), the elution strength of carbon dioxide is usually modulated by the use of polar organic solvents, also called modifiers. Alcohols like methanol, ethanol and isopropanol are the most commonly used co-solvents. While most applications of chiral SFC are optimized through a process of varying the co-solvent nature and proportion, only a limited number of thorough investigations have been carried out to unravel the effects of the co-solvent on the enantioseparation process. In an attempt to clarify the effect of the mobile phase co-solvent on enantioselective SFC separations, a wide range of compounds (achiral and chiral) were analyzed on an amylosic (Chiralpak AD-H) and a cellulosic (Lux cellulose-1) CSP. The influence of the modifier polarity and steric hindrance must be considered thus several different alcoholic solvents were evaluated: methanol, ethanol, 1-propanol, 2-propanol and 1-butanol, with a proportion of 10% in carbon dioxide. A selected group of racemates was further analyzed with varying proportions of each alcohol ranging from 5 to 25%. Besides, because mixtures of solvents were sometimes reported to produce unexpected results, a 50:50 mixture of methanol and ethanol was also evaluated. Chemometric methods provide some insight into the enantio-separation process and help identifying the differences between the mobile phase conditions.

  12. Physico-chemical and microbiological characterization of spontaneous fermentation of Cellina di Nardò and Leccino table olives

    PubMed Central

    Bleve, Gianluca; Tufariello, Maria; Durante, Miriana; Perbellini, Ezio; Ramires, Francesca A.; Grieco, Francesco; Cappello, Maria S.; De Domenico, Stefania; Mita, Giovanni; Tasioula-Margari, Maria; Logrieco, Antonio F.

    2014-01-01

    Table olives are one of the most important traditional fermented vegetables in Europe and their world consumption is constantly increasing. In the Greek style, table olives are obtained by spontaneous fermentations, without any chemical debittering treatment. Evolution of sugars, organic acids, alcohols, mono, and polyphenol compounds and volatile compounds associated with the fermentative metabolism of yeasts and bacteria throughout the natural fermentation process of the two Italian olive cultivars Cellina di Nardò and Leccino were determined. A protocol was developed and applied aimed at the technological characterization of lactic acid bacteria (LAB) and yeast strains as possible candidate autochthonous starters for table olive fermentation from Cellina di Nardò and Leccino cultivars. The study of the main physic-chemical parameters and volatile compounds during fermentation helped to determine chemical descriptors that may be suitable for monitoring olive fermentation. In both the analyzed table olive cultivars, aldehydes proved to be closely related to the first stage of fermentation (30 days), while higher alcohols (2-methyl-1-propanol; 3-methyl-1-butanol), styrene, and o-cymene were associated with the middle stage of fermentation (90 days) and acetate esters with the final step of olive fermentation (180 days). PMID:25389422

  13. A regenerative electrochemical sensor based on oligonucleotide for the selective determination of mercury(II).

    PubMed

    Han, Donghoon; Kim, Yang-Rae; Oh, Jeong-Wook; Kim, Tae Hyun; Mahajan, Rakesh Kumar; Kim, Jong Seung; Kim, Hasuck

    2009-09-01

    We have developed a selective, sensitive, and re-usable electrochemical sensor for Hg2+ ion detection. This sensor is based on the Hg2+-induced conformational change of a single-stranded DNA (ssDNA) which involves an electroactive, ferrocene-labeled DNA hairpin structure and provides strategically the selective binding of a thymine-thymine mismatch for the Hg2+ ion. The ferrocene-labeled DNA is self-assembled through S-Au bonding on a polycrystalline gold electrode surface and the surface blocked with 3-mercapto-1-propanol to form a mixed monolayer. The modified electrode showed a voltammetric signal due to a one-step redox reaction of the surface-confined ferrocenyl moiety. The 'signal-on' upon mercury binding could be attributed to a change in the conformation of ferrocene-labeled DNA from an open structure to a restricted hairpin structure. The differential pulse voltammetry (DPV) of the modified electrode showed a linear response of the ferrocene oxidation signal with increase of Hg2+ concentration in the range between 0.1 and 2 microM with a detection limit of 0.1 microM. The molecular beacon mercury(II) ion sensor was amenable to regeneration by simply unfolding the ferrocene-labeled DNA in 10 microM cysteine, and could be regenerated with no loss in signal gain upon subsequent mercury(II) ion binding.

  14. Comparisons of amine solvents for post-combustion CO{sub 2} capture: A multi-objective analysis approach

    SciTech Connect

    Lee, Anita S; Eslick, John C; Miller, David C; Kitchin, John R

    2013-10-01

    Amine solvents are of great interest for post-combustion CO{sub 2} capture applications. Although the development of new solvents is predominantly conducted at the laboratory scale, the ability to assess the performance of newly developed solvents at the process scale is crucial to identifying the best solvents for CO{sub 2} capture. In this work we present a methodology to evaluate and objectively compare the process performance of different solvents. We use Aspen Plus, with the electrolyte-NRTL thermodynamic model for the solvent CO{sub 2} interactions, coupled with a multi-objective genetic algorithm optimization to determine the best process design and operating conditions for each solvent. This ensures that the processes utilized for the comparison are those which are best suited for the specific solvent. We evaluate and compare the process performance of monoethanolamine (MEA), diethanolamine (DEA), and 2-amino-2-methyl-1-propanol (AMP) in a 90% CO{sub 2} capture process from a 550 MW coal fired power plant. From our analysis the best process specifications are amine specific and with those specific, optimized specifications DEA has the potential to be a better performing solvent than MEA, with a lower energy penalty and lower capital cost investment.

  15. Modifying of etching anisotropy of silicon substrates by surface active agents

    NASA Astrophysics Data System (ADS)

    Rola, Krzysztof; Zubel, Irena

    2011-04-01

    The influence of alcohol additives on etch rate anisotropy of Si(hkl) planes has been studied. The etching processes were carried out in 3 and 5 M KOH aqueous solutions saturated and non-saturated with alcohols. Isopropanol, 1-propanol and tert-butanol were examined. It has been showed that the etching process cannot be controlled only by the surface tension of the solution. Saturation of the etching solution with alcohols modifies etch rate anisotropy, lowering the ratio of the etch rate of (110) and vicinal planes to the etch rate of (100) plane. The morphology of Si(hkl) planes etched in 3 M KOH solution saturated with tert-butyl alcohol has been studied in detail. Smooth (331) and (221) planes have been achieved in this solution. The (100) plane turned out to be densely covered by hillocks, opposite to the (100) plane etched in weak-alkaline solution saturated with isopropanol. To explain this phenomenon, the mechanism of hillocks formation on Si(100) surface has been proposed.

  16. Modifying of etching anisotropy of silicon substrates by surface active agents

    NASA Astrophysics Data System (ADS)

    Rola, Krzysztof P.; Zubel, Irena

    2011-04-01

    The influence of alcohol additives on etch rate anisotropy of Si( hkl) planes has been studied. The etching processes were carried out in 3 and 5 M KOH aqueous solutions saturated and non-saturated with alcohols. Isopropanol, 1-propanol and tert-butanol were examined. It has been showed that the etching process cannot be controlled only by the surface tension of the solution. Saturation of the etching solution with alcohols modifies etch rate anisotropy, lowering the ratio of the etch rate of (110) and vicinal planes to the etch rate of (100) plane. The morphology of Si( hkl) planes etched in 3 M KOH solution saturated with tert-butyl alcohol has been studied in detail. Smooth (331) and (221) planes have been achieved in this solution. The (100) plane turned out to be densely covered by hillocks, opposite to the (100) plane etched in weak-alkaline solution saturated with isopropanol. To explain this phenomenon, the mechanism of hillocks formation on Si(100) surface has been proposed.

  17. Gene cloning and catalytic characterization of cold-adapted lipase of Photobacterium sp. MA1-3 isolated from blood clam.

    PubMed

    Kim, Young Ok; Khosasih, Vivia; Nam, Bo-Hye; Lee, Sang-Jun; Suwanto, Antonius; Kim, Hyung Kwoun

    2012-12-01

    A lipase-producing Photobacterium strain (MA1-3) was isolated from the intestine of a blood clam caught at Namhae, Korea. The lipase gene was cloned by shotgun cloning and encoded 340 amino acids with a molecular mass of 38,015 Da. It had a very low sequence identity with other bacterial lipases, with the exception of that of Photobacterium lipolyticum M37 (83.2%). The MA1-3 lipase was produced in soluble form when Escherichia coli cells harboring the gene were cultured at 18°C. Its optimum temperature and pH were 45°C and pH 8.5, respectively. Its activation energy was calculated to be 2.69 kcal/mol, suggesting it to be a cold-adapted lipase. Its optimum temperature, temperature stability, and substrate specificity were quite different from those of M37 lipase, despite the considerable sequence similarities. Meanwhile, MA1-3 lipase performed a transesterification reaction using olive oil and various alcohols including methanol, ethanol, 1-propanol, and 1-butanol. In the presence of t-butanol as a co-solvent, this lipase produced biodiesel using methanol and plant or waste oils. The highest biodiesel conversion yield (73%) was achieved using waste soybean oil and methanol at a molar ratio of 1:5 after 12 h using 5 units of lipase. PMID:22841866

  18. The Amino Acid Specificity for Activation of Phenylalanine Hydroxylase Matches the Specificity for Stabilization of Regulatory Domain Dimers.

    PubMed

    Zhang, Shengnan; Hinck, Andrew P; Fitzpatrick, Paul F

    2015-08-25

    Liver phenylalanine hydroxylase is allosterically activated by phenylalanine. The structural changes that accompany activation have not been identified, but recent studies of the effects of phenylalanine on the isolated regulatory domain of the enzyme support a model in which phenylalanine binding promotes regulatory domain dimerization. Such a model predicts that compounds that stabilize the regulatory domain dimer will also activate the enzyme. Nuclear magnetic resonance spectroscopy and analytical ultracentrifugation were used to determine the ability of different amino acids and phenylalanine analogues to stabilize the regulatory domain dimer. The abilities of these compounds to activate the enzyme were analyzed by measuring their effects on the fluorescence change that accompanies activation and on the activity directly. At concentrations of 10-50 mM, d-phenylalanine, l-methionine, l-norleucine, and (S)-2-amino-3-phenyl-1-propanol were able to activate the enzyme to the same extent as 1 mM l-phenylalanine. Lower levels of activation were seen with l-4-aminophenylalanine, l-leucine, l-isoleucine, and 3-phenylpropionate. The ability of these compounds to stabilize the regulatory domain dimer agreed with their ability to activate the enzyme. These results support a model in which allosteric activation of phenylalanine hydroxylase is linked to dimerization of regulatory domains.

  19. Alternative chromatographic system for the quality control of lipophilic technetium-99m radiopharmaceuticals such as [(99m)Tc(MIBI)₆].

    PubMed

    Faria, D P; Buchpiguel, C A; Marques, F L N

    2015-10-01

    Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [(99m)Tc(MIBI)₆]⁺ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol:chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [(99m)Tc(MIBI)₆]⁺ since impurities such as (99m)Tc-reduced-hydrolyzed (RH), (99m)TcO(4)(-) and [(99m)Tc(cysteine)₂]⁻ complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.

  20. Photoisomerization mechanism of 1,1‧-dimethyl-2,2‧-pyridocyanine in the gas phase and in solution

    NASA Astrophysics Data System (ADS)

    Gao, Aihua; Zhang, Peiyu; Zhao, Meiyu; Liu, Jianyong

    2015-02-01

    The trans→cis and cis→trans photoisomerization mechanisms of 1,1‧-dimethyl-2,2‧-pyridocyanine have been investigated theoretically in the gas phase and in methanol. Two-dimensional potential energy surfaces were computed for the ground and first excited singlet states of the isolated molecule using complete active space self-consistent field method. Our computations suggest that the torsion around the central Csbnd C bonds with carbon-out-of-plane motion is the preferred photoisomerization mechanism. In the gas phase, conical intersections were found near the minima of excited state. The excited-state decay follows a barrierless minimum-energy pathway before the molecule moves to the excited-state global minimum (minS1) and the system relaxes to the ground state through a conical intersection. In methanol, the system would first reach a stationary structure of C2 symmetry after the trans form is electronically excited. Solvent polarity effects were investigated in chloroform, dichloromethane, 1-propanol, ethanol, methanol, and water. There is a significant barrier between the stationary structure of C2 symmetry and minS1 in the excited state in high polarity solvents. Thus, Me-1122P has a much longer lifetime of the excited state in solvents of high polarity.

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

    PubMed

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

    2015-01-30

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

  2. Evaluation of alkanolamine solutions for carbon dioxide removal in cross-flow rotating packed beds.

    PubMed

    Lin, Chia-Chang; Lin, Yu-Hong; Tan, Chung-Sung

    2010-03-15

    The removal of CO(2) from a 10 vol% CO(2) gas by chemical absorption with 30 wt% alkanolamine solutions containing monoethanolamine (MEA), piperazine (PZ), and 2-amino-2-methyl-1-propanol (AMP) in the cross-flow rotating packed bed (RPB) was investigated. The CO(2) removal efficiency increased with rotor speed, liquid flow rate and inlet liquid temperature. However, the CO(2) removal efficiency decreased with gas flow rate. Also, the CO(2) removal efficiency was independent of inlet gas temperature. The 30 wt% alkanolamine solutions containing PZ with MEA were the appropriate absorbents compared with the single alkanolamine (MEA, AMP) and the mixed alkanolamine solutions containing AMP with MEA. A higher portion of PZ in alkanolamine solutions was more favorable to CO(2) removal. Owing to less contact time in the cross-flow RPB, alkanolamines having high reaction rates with CO(2) are suggested to be used. For the mixed alkanolamine solution containing 12 wt% PZ and 18 wt% MEA, the highest gas flow rate allowed to achieve the CO(2) removal efficiency more than 90% at a liquid flow rate of 0.54 L/min was of 29 L/min. The corresponding height of a transfer unit (HTU) was found to be less than 5.0 cm, lower than that in the conventional packed bed.

  3. Highly stabilized lipase in polyaniline nanofibers for surfactant-mediated esterification of ibuprofen.

    PubMed

    Hong, Sung-Gil; Kim, Han Sol; Kim, Jungbae

    2014-01-28

    Lipase (LP) from Candida rugosa was immobilized and stabilized in polyaniline nanofibers (PANFs) via a three-step process of enzyme adsorption, precipitation, and cross-linking, which generates the final immobilization called "EAPC". The activity of EAPC was 5.1 and 5.9 times higher than those of LP immobilizations via enzyme adsorption (EA) and enzyme adsorption/cross-linking (EAC), respectively. After incubation in an aqueous buffer under shaking (200 rpm) for 84 days, EAPC maintained 74% of its initial activity, while EA and EAC retained 11 and 24% of their initial activities, respectively. Highly stable and active EAPC was employed for the resolution of racemic ibuprofen via esterification of S-(+)-ibuprofen with 1-propanol in isooctane. The addition of 100 mM dioctyl sulfosuccinate (AOT) into the reaction medium increased the esterification activity by 61-fold, which can be explained by the better dispersion of EAPC in isooctane. EAPC showed 42% conversion in the esterification of racemic ibuprofen after 102 h, whereas EA and EAC showed only 1.2 and 1.4% conversion in the same condition, respectively. The EAPC approach increases both loading and stability of LP, and the combination of EAPC with the surfactant addition can be employed for efficient enzymatic reactions in organic solvents.

  4. Capillary electrochromatography-atmospheric pressure ionization mass spectrometry of pesticides using a surfactant-bound monolithic column

    PubMed Central

    Gu, Congying; Shamsi, Shahab A.

    2011-01-01

    A surfactant bound poly (11-acrylaminoundecanoic acid-ethylene dimethacrylate) (AAUA-EDMA) monolithic column was simply prepared by in-situ co-polymerization of AAUA and EDMA with 1-propanol, 1,4-butanediol and water as porogens in 100 µm id fused silica capillary in one step. This column was used in capillary electrochromatography (CEC)-atmospheric pressure photoionization (APPI)-mass spectrometry system for separation and detection of N-methylcarbamates (NMCs) pesticides. Numerous parameters are optimized for CEC-APPI-MS. After evaluation of the mobile phase composition, sheath liquid composition and the monolithic capillary outlet position, a fractional factorial design (FFD) was selected as a screening procedure to identify factors of ionization source parameters, such as sheath liquid flow rate, drying gas flow rate, drying gas temperature, nebulizing gas pressure, vaporizer temperature, and capillary voltage, which significantly influence APPI-MS sensitivity. A face-centered central composite design (CCD) was further utilized to optimize the most significant parameters and predict the best sensitivity. Under optimized conditions signal-to-noise ratios (S/N) around 78 were achieved for an injection of 100 ng/mL of each pesticide. Finally, this CEC-APPI-MS method was successfully applied to the analysis of nine NMCs in spiked apple juice sample after solid phase extraction with recoveries in the range of 65 to 109%. PMID:20349511

  5. Engineering Escherichia coli for Microbial Production of Butanone

    PubMed Central

    Srirangan, Kajan; Liu, Xuejia; Akawi, Lamees; Bruder, Mark; Moo-Young, Murray

    2016-01-01

    To expand the chemical and molecular diversity of biotransformation using whole-cell biocatalysts, we genetically engineered a pathway in Escherichia coli for heterologous production of butanone, an important commodity ketone. First, a 1-propanol-producing E. coli host strain with its sleeping beauty mutase (Sbm) operon being activated was used to increase the pool of propionyl-coenzyme A (propionyl-CoA). Subsequently, molecular heterofusion of propionyl-CoA and acetyl-CoA was conducted to yield 3-ketovaleryl-CoA via a CoA-dependent elongation pathway. Lastly, 3-ketovaleryl-CoA was channeled into the clostridial acetone formation pathway for thioester hydrolysis and subsequent decarboxylation to form butanone. Biochemical, genetic, and metabolic factors affecting relative levels of ketogenesis, acidogenesis, and alcohologenesis under selected fermentative culture conditions were investigated. Using the engineered E. coli strain for batch cultivation with 30 g liter−1 glycerol as the carbon source, we achieved coproduction of 1.3 g liter−1 butanone and 2.9 g liter−1 acetone. The results suggest that approximately 42% of spent glycerol was utilized for ketone biosynthesis, and thus they demonstrate potential industrial applicability of this microbial platform. PMID:26896132

  6. Determination of unique microbial volatile organic compounds produced by five Aspergillus species commonly found in problem buildings.

    PubMed

    Gao, Pengfei; Korley, Frederick; Martin, Jennifer; Chen, Bean T

    2002-01-01

    This study identified unique microbial volatile organic compounds (UMVOCs) produced by five Aspergillus species (A. fumigatus, A. versicolor, A. sydowi, A. flavus, and A. niger) cultivated on malt extract agar and gypsum board. The hypothesis was that UMVOCs can be used to predict the presence of Aspergillus species. During the cultivation humidified air was continually supplied and evenly distributed through each of the culture flasks. Volatile metabolites were collected using Tenax TA tubes on Days 8, 16, and 30 after inoculation. The volatile metabolites were determined by gas chromatography/mass spectroscopy after thermal desorption. Nine compounds recognized as UMVOCs--3-methyl-1-butanol; 2-methyl-1-propanol; terpineol; 2-heptanone; 1-octen-3-ol; dimethyl disulfide; 2-hexanone; 3-octanone; and 2-pentylfuran--were found on the cultures in detectable amounts. The first two compounds were detected at the highest frequency when combining both media. The first four compounds were found to be the dominant UMVOCs on gypsum board, which could be used as chemical markers of the common Aspergillus species grown indoors.

  7. CO2 capture in alkanolamine-RTIL blends via carbamate crystallization: route to efficient regeneration.

    PubMed

    Hasib-ur-Rahman, Muhammad; Larachi, Faïçal

    2012-10-16

    One of the major drawbacks of aqueous alkanolamine based CO(2) capture processes is the requirement of significantly higher energy of regeneration. This weakness can be overcome by separating the CO(2)-captured product to regenerate the corresponding amine, thus avoiding the consumption of redundant energy. Replacing aqueous phase with more stable and practically nonvolatile imidazolium based room-temperature ionic liquid (RTIL) provided a viable approach for carbamate to crystallize out as supernatant solid. In the present study, regeneration capabilities of solid carbamates have been investigated. Diethanolamine (DEA) carbamate as well as 2-amino-2-methyl-1-propanol (AMP) carbamate were obtained in crystalline form by bubbling CO(2) in alkanolamine-RTIL mixtures. Hydrophobic RTIL, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([hmim][Tf(2)N]), was used as aqueous phase substituent. Thermal behavior of the carbamates was observed by differential scanning calorimetry and thermogravimetric analysis, while the possible regeneration mechanism has been proposed through (13)C NMR and FTIR analyses. The results showed that decomposition of DEA-carbamate commenced at lower temperature (∼55 °C), compared to that of AMP-carbamate (∼75 °C); thus promising easy regeneration. The separation of carbamate as solid phase can offer two-way advantage by letting less volume to regenerate as well as by narrowing the gap between CO(2) capture and amine regeneration temperatures.

  8. Qualitative identification of volatile metabolites from two fungi and three bacteria species cultivated on two media.

    PubMed

    Kiviranta, H; Tuomainen, A; Reiman, M; Laitinen, S; Liesivuori, J; Nevalainen, A

    1998-11-01

    Two fungal species, Aspergillus fumigatus and Penicillium brevicompactum and three bacteria, Klebsiella pneumoniae, Enterobacter agglomerans and Streptomyces albus were cultivated on two media, malt extract agar and dichloran glycerol agar. The volatile metabolite samples from the cultures were adsorbed on Tenax TA and analyzed qualitatively by thermal desorption gas chromatography and with a mass selective detector. Various hydrocarbons, alcohols, ketones, esters and terpenes were identified. The production was highly dependent on both the medium and the microbial species. 2-Methyl-1-propanol, 2-methyl-1-butanol and 3-methyl-1-butanol were the most commonly produced substances. The bacterial species did not produce any hydrocarbons that were characteristic to the fungi (e.g. methyl-1,3-pentadiene, 1-octene and 1,3-octadiene or 8-carbon alcohols 1-octen-3-ol and 3-octanol). Instead, K. pneumoniae and E. agglomerans produced 3-hydroxy-2-butanone and 1-hydroxy-2-propanone, which were not produced by the fungi. Geosmin and a large number of sesquiterpenes were produced by S. albus.

  9. Spectroscopic and thermal properties of short wavelength metal (II) complexes containing α-isoxazolylazo-β-diketones as co-ligands

    NASA Astrophysics Data System (ADS)

    Huang, Fuxin; Wu, Yiqun; Gu, Donghong; Gan, Fuxi

    2005-10-01

    Two new azo dyes of α-isoxazolylazo-β-diketones and their Ni(II) and Cu(II) complexes with blue-violet light wavelength were synthesized using a coupling component, different diazo components and metal (II) ions (Ni 2+ and Cu 2+). Based on the elemental analysis, MS spectra and FT-IR spectral analyses, azo dyes were unequivocally shown to exist as hydrazoketo and azoenol forms which were respectively obtained from the solution forms and from the solid forms. The action of sodium methoxide (NaOMe) on azo dyes in solutions converts hydrazoketo form into azoenol form, so azo dyes are coordinated with metal (II) ions as co-ligands in the azoenol forms. The solubility of all the compounds in common organic solvents such as 2,2,3,3-tetrafluoro-1-propanol (TFP) or chloroform (CHCl 3) and absorption properties of spin-coating thin films were measured. The difference of absorption maxima from the complexes to their ligands was discussed. In addition, the TG analysis of the complexes was also determined, and their thermal stability was evaluated. It is found that these new metal (II) complexes had potential application for high-density digital versatile disc-recordable (HD-DVD-R) system due to their good solubility in organic solvents, reasonable and controllable absorption spectra in blue-violet light region and high thermal stability.

  10. Fatty Acid Oxidation by Spores of Penicillium roqueforti

    PubMed Central

    Gehrig, R. F.; Knight, S. G.

    1963-01-01

    When 1 μm sodium octanoate was the substrate for spores, most of the molecule was recovered as CO2 and no ketone was produced. However, when larger concentrations (20 μm) were used as substrate, part of the molecule was converted to methyl ketone and part was completely oxidized. Optimal conditions for the production of 2-heptanone were determined because of the importance of this compound in giving aroma and flavor to mold-ripened cheeses. Optimal ketone formation was not dependent upon the temperature and length of time at which the spores were stored. The spore suspensions were stored for over 36 months at 4 C without losing their ability to convert octanoic acid to 2-heptanone. The oxidation of octanoic acid was inhibited by cyanide, carbon monoxide, mercury, 2,3-dimercapto-1-propanol, and α, α-dipyridyl. No ketone was produced under anaerobic conditions. Although no intermediates of fatty acid oxidation were isolated, since an active cell-free preparation could not be obtained, this investigation has yielded some evidence for the beta oxidation of the fatty acids by spores of Penicillium roqueforti. PMID:13947000

  11. The solubility of hydrophobic aromatic chemicals in organic solvent/water mixtures

    SciTech Connect

    Dickhut, R.M.

    1989-01-01

    The influence of dissolved organic solvents on the aqueous phase solubility of hydrophobic aromatic chemicals was investigated. To provide a basis for a comprehensive evaluation of the importance of cosolvent properties on solubility, the effects of several different organic cosolvents on the solubility of a model hydrophobic solute, naphthalene, were determined. Naphthalene solubility was measured in binary, ternary, and quaternary alcohol/water (methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol) mixtures, binary ketone/water (acetone, methylethylketone, diethylketone), and aromatic organic solvent/water (benzene, toluene) mixtures. The solubility data were statistically evaluated and used to obtain an estimate of the overall accuracy of solubility measurements of hydrophobic chemicals in organic solvent/water mixtures. An accurate data base for mixed solvent solubility was established by combining the solubility data with additional solubility data obtained experimentally and from the literature. Thermodynamic models for predicting solubility in organic solvent/water mixtures were tested against the experimental data. The effects of organic cosolvent properties and solute hydrophobicity on solubility behavior and model predictive capability were evaluated. The results were used to evaluate the accuracy of existing models for predicting solubility and to explore possible molecular interactions in organic solvent/water mixtures.

  12. Comparative Transcriptome Analysis of Methylibium petroleiphilum PM1 Exposed to the Fuel Oxygenates Methyl tert-Butyl Ether and Ethanol▿ †

    PubMed Central

    Hristova, Krassimira R.; Schmidt, Radomir; Chakicherla, Anu Y.; Legler, Tina C.; Wu, Janice; Chain, Patrick S.; Scow, Kate M.; Kane, Staci R.

    2007-01-01

    High-density whole-genome cDNA microarrays were used to investigate substrate-dependent gene expression of Methylibium petroleiphilum PM1, one of the best-characterized aerobic methyl tert-butyl ether (MTBE)-degrading bacteria. Differential gene expression profiling was conducted with PM1 grown on MTBE and ethanol as sole carbon sources. Based on microarray high scores and protein similarity analysis, an MTBE regulon located on the megaplasmid was identified for further investigation. Putative functions for enzymes encoded in this regulon are described with relevance to the predicted MTBE degradation pathway. A new unique dioxygenase enzyme system that carries out the hydroxylation of tert-butyl alcohol to 2-methyl-2-hydroxy-1-propanol in M. petroleiphilum PM1 was discovered. Hypotheses regarding the acquisition and evolution of MTBE genes as well as the involvement of IS elements in these complex processes were formulated. The pathways for toluene, phenol, and alkane oxidation via toluene monooxygenase, phenol hydroxylase, and propane monooxygenase, respectively, were upregulated in MTBE-grown cells compared to ethanol-grown cells. Four out of nine putative cyclohexanone monooxygenases were also upregulated in MTBE-grown cells. The expression data allowed prediction of several hitherto-unknown enzymes of the upper MTBE degradation pathway in M. petroleiphilum PM1 and aided our understanding of the regulation of metabolic processes that may occur in response to pollutant mixtures and perturbations in the environment. PMID:17890343

  13. Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

    PubMed

    Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

    2009-05-01

    The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product. PMID:19238469

  14. Characterization of an organic phase peroxide biosensor based on horseradish peroxidase immobilized in Eastman AQ.

    PubMed

    Konash, Anastassija; Magner, Edmond

    2006-07-15

    Due to their frequent occurrence in food, cosmetics and pharmaceutical products, and their poor solubility in water, the detection of peroxides in organic solvents has aroused significant interest. For diagnostics or on-site testing, a fast and specific experimental approach is required. Although aqueous peroxide biosensors are well known, they are usually not suitable for nonaqueous applications due to their instability. Here we describe an organic phase biosensor for hydrogen peroxide based on horseradish peroxidase immobilized in an Eastman AQ 55 polymer matrix. Rotating disc amperometry was used to examine the effect of the solvent properties, the amount and pH of added buffer, the concentration of peroxide and ferrocene dimethanol, and the amount of Eastman AQ 55 and of enzyme on the response of the biosensor to hydrogen peroxide. The response of the biosensor was limited by diffusion. Linear responses (with detection limits to hydrogen peroxide given in parentheses) were obtained in methanol (1.2 microM), ethanol (0.6 microM), 1-propanol (2.8 microM), acetone (1.4 microM), acetonitrile (2.6 microM), and ethylene glycol (13.6 microM). The rate of diffusion of ferrocene dimethanol was more constrained than the rate of diffusion of hydrogen peroxide, resulting in a comparatively narrow linear range. The main advantages of the sensor are its ease of use and a high degree of reproducibility, together with good operational and storage stability.

  15. Analysis of methanol and ethanol in virgin olive oil

    PubMed Central

    Gómez-Coca, Raquel B.; Cruz-Hidalgo, Rosario; Fernandes, Gabriel D.; Pérez-Camino, María del Carmen; Moreda, Wenceslao

    2014-01-01

    This work provides a short and easy protocol that allows the analysis of both methanol and ethanol in the static headspace of olive oil. The procedure avoids any kind of sample pre-treatment beyond that of heating the oil to allow a maximum volatile concentration in the headspace of the vials. The method's LOD is 0.55 mg kg−1 and its LOQ is 0.59 mg kg−1. Advantages of this method are:•Simultaneous determination of methanol and ethanol (the pre-existing Spanish specification UNE-EN 14110 only analyses methanol).•No need of equipment modifications (standard split injectors work perfectly). Use of a highly polar capillary GC column, leading in most cases to chromatograms in which only three dominant peaks are present – methanol, ethanol, and propanol (that is extremely positive for easy interpretation of results).•Use of an internal standard (1-propanol) to determine the concentration of the analytes, reducing the presence of error sources. PMID:26150954

  16. Adsorption and Reaction of C1-C3 Alcohols over CeOx(111) Thin Films

    SciTech Connect

    D Mullins; S Senanayake; T Chen

    2011-12-31

    This study reports the interaction of methanol, ethanol, 1-propanol, and 2-propanol with well-ordered CeO{sub 2}(111) thin film surfaces. All of the alcohols adsorb at low temperature by forming alkoxy and hydroxyl species on the surface. On fully oxidized CeO{sub 2}(111), recombination occurs between some of the alkoxys and hydroxyls, resulting in alcohol desorption near 220 K. At the same temperature, some of the surface hydroxyls disproportionate to produce water and the loss of lattice O. The remaining alkoxys react above 550 K. The primary alcohols favor dehydrogenation products (aldehydes). There is a net loss of O from the system, resulting in a reduction of the ceria. The secondary alcohol, 2-propanol, undergoes primarily dehydration, producing propene with no net change in the cerium oxidation state. Reduced CeO{sub x}(111) competes with the gaseous products for available O. Little or no water is produced. The reaction selectivity for the C{sub 2} and C{sub 3} alcohols shifts toward favoring dehydration products. The loss of O from the alcohols leads to oxidation of the reduced ceria. Compared with the oxidized surface, the alkene desorption shifts to lower temperature, whereas the aldehyde desorption shifts to higher temperature. This indicates that, on the reduced surface, it is easier to break the C-O bond but more difficult to break the O-substrate bond.

  17. Adsorption and Reaction of C(1)-C(3) Alcohols over CeO(x)(111) Thin Films

    SciTech Connect

    Mullins, David R; Senanayake, Sanjaya D; Chen, Tsung-Liang

    2010-01-01

    This study reports the interaction of methanol, ethanol, 1-propanol, and 2-propanol with well-ordered CeO{sub 2}(111) thin film surfaces. All of the alcohols adsorb at low temperature by forming alkoxy and hydroxyl species on the surface. On fully oxidized CeO{sub 2}(111), recombination occurs between some of the alkoxys and hydroxyls, resulting in alcohol desorption near 220 K. At the same temperature, some of the surface hydroxyls disproportionate to produce water and the loss of lattice O. The remaining alkoxys react above 550 K. The primary alcohols favor dehydrogenation products (aldehydes). There is a net loss of O from the system, resulting in a reduction of the ceria. The secondary alcohol, 2-propanol, undergoes primarily dehydration, producing propene with no net change in the cerium oxidation state. Reduced CeO{sub X}(111) competes with the gaseous products for available O. Little or no water is produced. The reaction selectivity for the C{sub 2} and C{sub 3} alcohols shifts toward favoring dehydration products. The loss of O from the alcohols leads to oxidation of the reduced ceria. Compared with the oxidized surface, the alkene desorption shifts to lower temperature, whereas the aldehyde desorption shifts to higher temperature. This indicates that, on the reduced surface, it is easier to break the C-O bond but more difficult to break the O-substrate bond.

  18. Densities of aqueous blended amines

    SciTech Connect

    Hsu, C.H.; Li, M.H.

    1997-05-01

    Solutions of alkanolamines are an industrially important class of compounds used in the natural gas and synthetic ammonia industries and petroleum chemical plants for the removal of CO{sub 2} and H{sub 2}S from gas streams. The densities of aqueous mixtures of diethanolamine (DEA) + N-methyldiethanolamine (MDEA) + water, DEA + 2-amino-2-methyl-1-propanol (AMP) + water, and monoethanolamine (MEA) + 2-piperidineethanol (2-PE) + water were measured from 30 C to 80 C. A Redlich-Kister equation of the excess volume was applied to represent the density. Based on the available density data for five ternary systems: MEA + MDEA + H{sub 2}O, MEA + AMP + H{sub 2}O, DEA + MDEA + H{sub 2}O, DEA + AMP + H{sub 2}O, and MEA + 2-PE + H{sub 2}O, a generalized set of binary parameters were determined. The density calculations show quite satisfactory results. The overall average absolute percent deviation is about 0.04% for a total of 686 data points.

  19. Viscosities of aqueous blended amines

    SciTech Connect

    Hsu, C.H.; Li, M.H.

    1997-07-01

    Solutions of alkanolamines are an industrially important class of compounds used in the natural gas, oil refineries, petroleum chemical plants, and synthetic ammonia industries for the removal of acidic components like CO{sub 2} and H{sub 2}S from gas streams. The viscosities of aqueous mixtures of diethanolamine (DEA) + N-methyldiethanolamine (MDEA), DEA + 2-amino-2-methyl-1-propanol (AMP), and monoethanolamine (MEA) + 2-piperidineethanol (2-PE) were measured from 30 C to 80 C. A Redlich-Kister equation for the viscosity deviation was applied to represent the viscosity. On the basis of the available viscosity data for five ternary systems, MEA + MDEA + H{sub 2}O, MEA + AMP + H{sub 2}O, DEA + MDEA + H{sub 2}O, DEA + AMP + H{sub 2}O, and MEA + 2-PE + H{sub 2}O, a generalized set of binary parameters were determined. For the viscosity calculation of the systems tested, the overall average absolute percent deviation is about 1.0% for a total of 499 data points.

  20. Solubility of nitrous oxide in alkanolamine aqueous solutions

    SciTech Connect

    Tsai, T.C.; Ko, J.J.; Wang, H.M.; Lin, C.Y.; Li, M.H.

    2000-04-01

    The solubility of nitrous oxide (N{sub 2}O) in alkanolamine aqueous solutions has been measured at (30, 35, and 40) C. The systems studied are monoethanolamine, diethanolamine, diisopropanolamine, triethanolamine, and 2-amino-2-methyl-1-propanol aqueous solutions. The concentration of amine for monoethanolamine ranges from (1 to 6) kmol/m{sup 3} and for other amines from (0.5 to 3) kmol/m{sup 3}. The accuracy of the measurement is estimated to be {+-}2%. A semiempirical model of the excess Henry's constant proposed by Wang et al. (1992) was used to correlate the solubility of N{sub 2}O in amine solutions. The parameters of the correlation were determined from the measured solubility data and the available data in the open literature. For a wide temperature range from (15 to 75) C, the obtained correlation has been shown to represent reasonably the solubility of N{sub 2}O in six amine aqueous solutions: MEA, DEA, DIPA, TEA, MDEA, and AMP. For the purpose of process design, the obtained correlations are, in general, satisfactory for estimating the solubility of N{sub 2}O in amine solutions, which in turn can be used to estimate the correct free-gas solubility of CO{sub 2} in amines.

  1. Development of indole chemistry to label tryptophan residues in protein for determination of tryptophan surface accessibility.

    PubMed

    Ladner, Carol L; Turner, Raymond J; Edwards, Robert A

    2007-06-01

    Solvent accessibility can be used to evaluate protein structural models, identify binding sites, and characterize protein conformational changes. The differential modification of amino acids at specific sites enables the accessible surface residues to be identified by mass spectrometry. Tryptophan residues within proteins can be differentially labeled with halocompounds by a photochemical reaction. In this study, tryptophan residues of carbonic anhydrase are reacted with chloroform, 2,2,2-trichloroethanol (TCE), 2,2,2-trichloroacetate (TCA), or 3-bromo-1-propanol (BP) under UV irradiation at 280 nm. The light-driven reactions with chloroform, TCE, TCA, and BP attach a formyl, hydroxyethanone, carboxylic acid, and propanol group, respectively, onto the indole ring of tryptophan. Trypsin and chymotrypsin digests of the modified carbonic anhydrase are used to map accessible tryptophan residues using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Tryptophan reactivity is determined by identifying peptides with tryptophan residues modified with the appropriate label. The reactivity is calculated from the frequency that the modification is identified and a semiquantitative measure of the amount of products formed. Both of these measures of tryptophan reactivity correlate significantly with the accessible surface area of tryptophan residues in carbonic anhydrase determined from the X-ray crystal structure. Therefore the photochemical reaction of halocompounds with tryptophan residues in carbonic anhydrase indicates the degree of solvent accessibility of these residues. PMID:17525468

  2. Thermal desorption gas chromatography with mass spectrometry study of outgassing from polymethacrylimide foam (Rohacell®).

    PubMed

    Carrasco-Correa, Enrique J; Herrero-Martínez, José M; Consuegra, Lina; Ramis-Ramos, Guillermo; Sanz, Rafael Mata; Martínez, Benito Gimeno; Esbert, Vicente E Boria; García-Baquero, David Raboso

    2015-09-01

    Polymethacrylimide foams are used as light structural materials in outer-space devices; however, the foam closed cells contain volatile compounds that are outgassed even at low temperatures. These compounds ignite as plasmas under outer-space radiation and the intense radio-frequency fields used in communications. Since plasmas may cause spacecraft fatal events, the conditions in which they are ignited should be investigated. Therefore, qualitative and quantitative knowledge about polymethacrylimide foam outgassing should be established. Using thermogravimetric analysis, weight losses reached 3% at ca. 200°C. Thermal desorption gas chromatography with mass spectrometry detection was used to study the offgassed compounds. Using successive 4 min heating cycles at 125°C, each one corresponding to an injection, significant amounts of nitrogen (25.3%), water (2.6%), isobutylene (11.3%), tert-butanol (2.9%), 1-propanol (11.9%), hexane (25.3%), propyl methacrylate (1.4%), higher hydrocarbons (11.3%), fatty acids (2.2%) and their esters (1.3%), and other compounds were outgassed. Other compounds were observed during the main stage of thermal destruction (220-280°C). A similar study at 175°C revealed the extreme difficulty in fully outgassing polar compounds from polymethacrylimide foams by baking and showed the different compositions of the offgassed atmosphere that can be expected in the long term.

  3. Lipase-catalysed production of biodiesel fuel from some Nigerian lauric oils.

    PubMed

    Abigor, R D; Uadia, P O; Foglia, T A; Haas, M J; Jones, K C; Okpefa, E; Obibuzor, J U; Bafor, M E

    2000-12-01

    Fatty acids esters were produced from two Nigerian lauric oils, palm kernel oil and coconut oil, by transesterification of the oils with different alcohols using PS30 lipase as a catalyst. In the conversion of palm kernel oil to alkyl esters (biodiesel), ethanol gave the highest conversion of 72%, t-butanol 62%, 1-butanol 42%, n-propanol 42% and iso-propanol 24%, while only 15% methyl ester was observed with methanol. With coconut oil, 1-butanol and iso-butanol achieved 40% conversion, 1-propanol 16% and ethanol 35%, while only traces of methyl esters were observed using methanol. Studies on some fuel properties of palm kernel oil and its biodiesel showed that palm kernel oil had a viscosity of 32.40 mm2/s, a cloud point of 28 degrees C and a pour point of 22 degrees C, while its biodiesel fuel had a viscosity of 9.33 mm2/s, a cloud point of 12 degrees C and a pour point of 8 degrees C. Coconut oil had a viscosity of 28.58 mm(2)/s, a cloud point of 27 degrees C and a pour point of 20 degrees C, while its biodiesel fuel had a viscosity of 7.34 mm2/s, a cloud point of 5 degrees C and a pour point of -8 degrees C. Some of the fuel properties compared favourably with international biodiesel specifications. PMID:11171279

  4. Close correlation between heat shock response and cytotoxicity in Neurospora crassa treated with aliphatic alcohols and phenols

    SciTech Connect

    Meyer, U.; Schweim, P.; Fracella, F.; Rensing, L.

    1995-03-01

    In Neurospora crassa the aliphatic alcohols methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, isobutanol, ethylene glycol, glycerol, and allyl alcohol and the phenolic compounds phenol, hydroquinone, resorcinol, pyrogallol, phloroglucinol, sodium salicylate, and acetylsalicylic acid were analyzed with respect to their capacities to induce heat shock proteins (HSP) and to inhibit protein synthesis. Both the alcohols and phenols showed the greatest levels of HSP induction at concentrations which inhibited the overall protein synthesis by about 50%. The abilities of the different alcohols to induce the heat shock response are proportional to their lipophilicities: the lipophilic alcohol isobutanol is maximally inductive at about 0.6 M, whereas the least lipophilic alcohol, methanol, causes maximal induction at 5.7 M. The phenols, in general, show a higher capability to induce the heat shock response. The concentrations for maximal induction range between 25 mM (sodium salicylate) and 100 mM (resorcinol). Glycerol (4.1 M) shifted the concentration necessary for maximal HSP induction by hydroquinone from 50 to 200 mM. The results reveal that the induction of HSP occurs under conditions which considerably constrain cell metabolism. The heat shock response, therefore, does not represent a sensitive marker for toxicity tests but provides a good estimate for the extent of cell damage.

  5. Detection of palladium by cold atom solution atomic absorption.

    PubMed

    Molloy, John L; Holcombe, James A

    2006-09-15

    One of the largest obstacles in miniaturizing traditional atomic spectroscopic sources is the need for a thermal/electrical source for free atom production. A single article in the literature has demonstrated atomic absorption detection of Ag, Cu, and Pd in solution at room temperature for atoms in the gas phase, which may ultimately permit miniaturization. Unfortunately, several laboratories have found that reproducing the phenomenon has been difficult. Without a sound fundamental explanation of the processes leading to the signal, one must conclude that it can be done, but some unsuspected and unknown design/methodological nuances are responsible for only a single reported success. Gas phase atoms could exist at room temperature "in solution" if the atoms were trapped in very small bubbles. In the current study, submicrometer-sized bubbles were created in a flow-through cell during the mixing of an alcohol-water solution containing a reducing agent with water containing the analyte. A repeatable atomic absorption signal was produced. Replacement of ethanol with 1-propanol and use of a surfactant increased the signal. Limits of detection of approximately 100 ppb in Pd were achieved, and it is estimated that approximately 0.4% of the Pd initially added is contained within the bubbles as gaseous atoms. The paper discusses the fundamental processes needed to achieve a repeatable signal. PMID:16970344

  6. PDMP induces rapid changes in vacuole morphology in Arabidopsis root cells.

    PubMed

    Krüger, Falco; Krebs, Melanie; Viotti, Corrado; Langhans, Markus; Schumacher, Karin; Robinson, David G

    2013-01-01

    PDMP (D-L-threo-1-phenyl-2-decanoyl amino-3-morpholino-1-propanol) is a well-known inhibitor of glucosylceramide synthase (GCS), a key enzyme in sphingolipid biosynthesis. Through the resultant increase in ceramides which interact with mTOR and Beclin1 (Atg6), this drug is also known to induce macroautophagy in mammalian cells. This study investigated the response of Arabidopsis root cells to PDMP, and what are probably numerous tightly packed small vacuoles in the control cells appear to fuse to form a single globular-shaped vacuole. However, during this fusion process, cytoplasm channels between the individual vacuoles become trapped in deep invaginations of the tonoplast. In both optical sections in the confocal laser scanning microscope and in ultrathin sections in the electron microscope, these invaginations have the appearance of cytoplasmic inclusions in the vacuole lumen. These changes in vacuole morphology are rapid (occurring within minutes after application of PDMP) and are independent of ongoing protein synthesis. The tonoplast invaginations remain visible for hours, but after 24h almost all disappear. Experiments designed to examine whether ceramide levels might be the cause of the PDMP effect have not proved conclusive. On the other hand, this study has been able to rule out the release of Ca(2+) ions from intracellular stores as a contributing factor.

  7. Isobutanol-methanol mixtures from synthesis gas. Quarterly technical progress report, 1 January--31 March 1996

    SciTech Connect

    1996-04-20

    A series of CuMgCeO{sub x} catalysts have been prepared. Range of Cu dispersion, determined by N{sub 2}O titration, was 19-48% and are among the highest reported in the literature for Cu-based methanol and higher alcohol synthesis catalysts. Kinetics of MeOH and EtOH coupling reactions on Cu/ZnO and K-Cu/MgO/CeO{sub 2} catalysts indicate that Cu promotes alcohol dehydrogenation. Acetaldehyde is a reactive intermediate. High-pressure isobutanol synthesis studies have been carried out on K- and Cs-promoted Cu/MgO/CeO{sub 2} catalysts. The K promoter is more active than Cs for CO conversion, but the Cs promoter activates the C{sub 1} to C{sub 2} step more effectively. Catalysts with high alkali loading resulted in low conversions. Temperature programmed surface reaction studies of MeOH, EtOH, and acetaldehyde on MgO/CeO{sub 2}-based Cu catalysts show evolution of acetone, crotonaldehyde, methyl ethyl ketone, H2, carbon oxides. Neither EtOH nor acetaldehyde produces propionaldehyde or 1- propanol, suggesting that these C{sub 3} species can only form via reactions involving C{sub 1} and C{sub 2} oxygenate species.

  8. Purification of pectinase from mango (Mangifera indica L. cv. Chokanan) waste using an aqueous organic phase system: a potential low cost source of the enzyme.

    PubMed

    Amid, Mehrnoush; Abdul Manap, Mohd Yazid; Mustafa, Shuhaimi

    2013-07-15

    As a novel method of purification, an aqueous organic phase system (AOPS) was employed to purify pectinase from mango waste. The effect of different parameters, such as the alcohol concentration (ethanol, 1-propanol, and 2-propanol), the salt type and concentration (ammonium sulfate, potassium phosphate and sodium citrate), the feed stock crude load, the aqueous phase pH and NaCl concentration, were investigated in the recovery of pectinase from mango peel. The partition coefficient (K), selectivity (S), purification factor (PF) and yield (Y, %) were investigated in this study as important parameters for the evaluation of enzyme recovery. The desirable partition efficiency for pectinase purification was achieved in an AOPS of 19% (w/w) ethanol and 22% (w/w) potassium phosphate in the presence of 5% (w/w) NaCl at pH 7.0. Based on the system, the purification factor of pectinase was enhanced 11.7, with a high yield of 97.1%.

  9. Chromatographic efficiency comparison of polyhedral oligomeric silsesquioxanes-containing hybrid monoliths via photo- and thermally-initiated free-radical polymerization in capillary liquid chromatography for small molecules.

    PubMed

    Wang, Hongwei; Ou, Junjie; Liu, Zhongshan; Lin, Hui; Peng, Xiaojun; Zou, Hanfa

    2015-09-01

    Monolithic poly(methacrylate epoxy cyclosiloxane-co-polyhedral oligomeric silsesquioxanes) (epoxy-MA-POSS) capillary columns have been prepared via either photo- or thermally-initiated polymerization of the corresponding monomers using a 1-propanol/PEG 400 mixture as porogens. Photochemical polymerization was accomplished by irradiation of the UV-transparent capillary for 10min at room temperature, while thermal polymerization was performed at 55°C, 60°C or 65°C for 18h. The evaluation of chromatographic property for two hybrid epoxy-MA-POSS monoliths was carried out. The results indicate that hybrid monoliths fabricated by photochemical initiation exhibit higher column efficiency (97,000-98,400plates/m) than those synthesized by thermal polymerization (41,100-48,000plates/m) in cLC. The higher efficiency of photo-initiated hybrid monoliths is closely related to lower eddy dispersion (A-term) and mass transfer resistance (C-term).

  10. Water miscible mono alcohols' effect on the proteolytic performance of Bacillus clausii serine alkaline protease.

    PubMed

    Duman, Yonca Avci; Kazan, Dilek; Denizci, Aziz Akin; Erarslan, Altan

    2014-01-01

    In this study, our investigations showed that the increasing concentrations of all examined mono alcohols caused a decrease in the Vm, kcat and kcat/Km values of Bacillus clausii GMBE 42 serine alkaline protease for casein hydrolysis. However, the Km value of the enzyme remained almost the same, which was an indicator of non-competitive inhibition. Whereas inhibition by methanol was partial non-competitive, inhibition by the rest of the alcohols tested was simple non-competitive. The inhibition constants (KI) were in the range of 1.32-3.10 M, and the order of the inhibitory effect was 1-propanol>2-propanol>methanol>ethanol. The ΔG(≠) and ΔG(≠)E-T values of the enzyme increased at increasing concentrations of all alcohols examined, but the ΔG(≠)ES value of the enzyme remained almost the same. The constant Km and ΔG(≠)ES values in the presence and absence of mono alcohols indicated the existence of different binding sites for mono alcohols and casein on enzyme the molecule. The kcat of the enzyme decreased linearly by increasing log P and decreasing dielectric constant (D) values, but the ΔG(≠) and ΔG(≠)E-T values of the enzyme increased by increasing log P and decreasing D values of the reaction medium containing mono alcohols. PMID:24092453

  11. Isolation and Characterization of Ethane, Propane, and Butane Consuming Bacteria from Marine Hydrocarbon Seeps

    NASA Astrophysics Data System (ADS)

    Redmond, M. C.; Valentine, D. L.

    2005-12-01

    Three strains of ethane, propane, or butane consuming bacteria were isolated from marine hydrocarbon seep sediments at Coal Oil Point, off shore Santa Barbara, CA. These three isolates (MR1, MR2 and MR3) were capable of growth at natural environmental temperatures and salinity. Isolate MR2 was capable of growth on ethane or propane as the sole carbon source, isolate MR4 on propane or butane, and isolate MR3 on ethane, propane, or butane. All three isolates were also able to grow on other carbon-containing molecules, including ethanol, 1-propanol, 2-propanol, acetate, butyrate, sucrose, and dextrose, and isolates MR3 and MR4 were able to grow on 1-butanol and 2-butanol. None showed significant growth with methane, methanol, or formate as the sole carbon source. 16S rDNA sequencing indicated that isolate MR2 was most closely related to the gamma-Proteobacterium Pseudomonas stutzeri, while isolates MR3 and MR4 were both Gram-positive and most similar to Rhodococcus wratislaviensis and Rhodococcus opacus, respectively. Compared to methanotrophs, relatively little is known about the organisms that consume the C2-C4 alkanes, but both our isolates and the previously described species appear to be capable of metabolizing a wide variety of carbon compounds, including several common pollutants. The growth of these hydrocarbon-oxidizing bacteria on other organic compounds raises the possibility that the abundance and distribution of organic matter might be expected to impact the oxidation of C2-C4 hydrocarbons. Additional studies will further characterize the range of metabolism, and will investigate the importance of these organisms in natural hydrocarbon seep environments.

  12. Crystal Structure, Cytotoxicity and Interaction with DNA of Zinc (II) Complexes with o-Vanillin Schiff Base Ligands

    PubMed Central

    Niu, Mei-Ju; Li, Zhen; Chang, Guo-Liang; Kong, Xiang-Jin; Hong, Min; Zhang, Qing-fu

    2015-01-01

    Two new zinc complexes, Zn(HL1)2 (1) and [Zn2(H2L2)(OAc)2]2 (2) [H2L1 = Schiff base derived from o-vanillin and (R)-(+)-2-amino-3-phenyl-1-propanol, H3L2 = Schiff base derived from o-vanillin and 2-amino-2-ethyl-1,3-propanediol], have been synthesized and characterized by single crystal X-ray diffraction, elemental analyses, TG analyses, solid fluorescence, IR, UV-Vis and circular dichroism spectra. The structural analysis shows that complex 1 has a right-handed double helical chain along the crystallographic b axis. A homochiral 3D supramolecular architecture has been further constructed by intermolecular C-H··· π, O-H···O and C-H···O interactions. Complex 2 includes two crystallographically independent binuclear zinc molecules. The two binuclear zinc molecules are isostructural. The 2-D sheet supramolecular structure was formed by intermolecular hydrogen bonding interaction. The fluorescence of ligands and complexes in DMF at room temperature are studied. The interactions of two complexes with calf thymus DNA (CT-DNA) are investigated using UV-Vis, CD and fluorescence spectroscopy. The results show that complex 1 exhibits higher interaction with CT-DNA than complex 2. In addition, in vitro cytotoxicity of the complexes towards four kinds of cancerous cell lines (A549, HeLa, HL-60 and K562) were assayed by the MTT method. Investigations on the structures indicated that the chirality and nuclearity of zinc complexes play an important role on cytotoxic activity. PMID:26114437

  13. Improved intervention of atherosclerosis and cardiac hypertrophy through biodegradable polymer-encapsulated delivery of glycosphingolipid inhibitor.

    PubMed

    Mishra, S; Bedja, D; Amuzie, C; Foss, C A; Pomper, M G; Bhattacharya, R; Yarema, K J; Chatterjee, S

    2015-09-01

    D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), a glycosphingolipid synthesis inhibitor, holds promise for the treatment of atherosclerosis and cardiac hypertrophy but rapid in vivo clearance has severely hindered translation to the clinic. To overcome this impediment, we used a materials-based delivery strategy wherein D-PDMP was encapsulated within a biodegradable polymer composed of poly ethylene glycol (PEG) and sebacic acid (SA). PEG-SA was formulated into nanoparticles that were doped with (125)I-labeled PEG to allow in vivo bio-distribution and release kinetics of D-PDMP to be determined by using γ-scintigraphy and subsequently, by mass spectrometry. Polymer-encapsulation increased the residence time of D-PDMP in the body of a treated mouse from less than one hour to at least four hours (and up to 48 h or longer). This substantially increased in vivo longevity provided by polymer encapsulation resulted in an order of magnitude gain in efficacy for interfering with atherosclerosis and cardiac hypertrophy in apoE-/- mice fed a high fat and high cholesterol (HFHC) diet. These results establish that D-PDMP encapsulated in a biodegradable polymer provides a superior mode of delivery compared to unconjugated D-PDMP by way of increased gastrointestinal absorption and increased residence time thus providing this otherwise rapidly cleared compound with therapeutic relevance in interfering with atherosclerosis, cardiac hypertrophy, and probably other diseases associated with the deleterious effects of abnormally high glycosphingolipid biosynthesis or deficient catabolism.

  14. Prediction of aged red wine aroma properties from aroma chemical composition. Partial least squares regression models.

    PubMed

    Aznar, Margarita; López, Ricardo; Cacho, Juan; Ferreira, Vicente

    2003-04-23

    Partial least squares regression (PLSR) models able to predict some of the wine aroma nuances from its chemical composition have been developed. The aromatic sensory characteristics of 57 Spanish aged red wines were determined by 51 experts from the wine industry. The individual descriptions given by the experts were recorded, and the frequency with which a sensory term was used to define a given wine was taken as a measurement of its intensity. The aromatic chemical composition of the wines was determined by already published gas chromatography (GC)-flame ionization detector and GC-mass spectrometry methods. In the whole, 69 odorants were analyzed. Both matrixes, the sensory and chemical data, were simplified by grouping and rearranging correlated sensory terms or chemical compounds and by the exclusion of secondary aroma terms or of weak aroma chemicals. Finally, models were developed for 18 sensory terms and 27 chemicals or groups of chemicals. Satisfactory models, explaining more than 45% of the original variance, could be found for nine of the most important sensory terms (wood-vanillin-cinnamon, animal-leather-phenolic, toasted-coffee, old wood-reduction, vegetal-pepper, raisin-flowery, sweet-candy-cacao, fruity, and berry fruit). For this set of terms, the correlation coefficients between the measured and predicted Y (determined by cross-validation) ranged from 0.62 to 0.81. Models confirmed the existence of complex multivariate relationships between chemicals and odors. In general, pleasant descriptors were positively correlated to chemicals with pleasant aroma, such as vanillin, beta damascenone, or (E)-beta-methyl-gamma-octalactone, and negatively correlated to compounds showing less favorable odor properties, such as 4-ethyl and vinyl phenols, 3-(methylthio)-1-propanol, or phenylacetaldehyde.

  15. Measurement of nitrosamine and nitramine formation from NOx reactions with amines during amine-based carbon dioxide capture for postcombustion carbon sequestration.

    PubMed

    Dai, Ning; Shah, Amisha D; Hu, Lanhua; Plewa, Michael J; McKague, Bruce; Mitch, William A

    2012-09-01

    With years of full-scale experience for precombustion CO(2) capture, amine-based technologies are emerging as the prime contender for postcombustion CO(2) capture. However, concerns for postcombustion applications have focused on the possible contamination of air or drinking water supplies downwind by potentially carcinogenic N-nitrosamines and N-nitramines released following their formation by NO(x) reactions with amines within the capture unit. Analytical methods for N-nitrosamines in drinking waters were adapted to measure specific N-nitrosamines and N-nitramines and total N-nitrosamines in solvent and washwater samples. The high levels of amines, aldehydes, and nitrite in these samples presented a risk for the artifactual formation of N-nitrosamines during sample storage or analysis. Application of a 30-fold molar excess of sulfamic acid to nitrite at pH 2 destroyed nitrite with no significant risk of artifactual nitrosation of amines. Analysis of aqueous morpholine solutions purged with different gas-phase NO and NO(2) concentrations indicated that N-nitrosamine formation generally exceeds N-nitramine formation. The total N-nitrosamine formation rate was at least an order of magnitude higher for the secondary amine piperazine (PZ) than for the primary amines 2-amino-2-methyl-1-propanol (AMP) and monoethanolamine (MEA) and the tertiary amine methyldiethanolamine (MDEA). Analysis of pilot washwater samples indicated a 59 μM total N-nitrosamine concentration for a system operated with a 25% AMP/15% PZ solvent, but only 0.73 μM for a 35% MEA solvent. Unfortunately, a greater fraction of the total N-nitrosamine signal was uncharacterized for the MEA-associated washwater. At a 0.73 μM total N-nitrosamine concentration, a ~25000-fold reduction in concentration is needed between washwater units and downwind drinking water supplies to meet proposed permit limits.

  16. Effects of new Torulaspora delbrueckii killer yeasts on the must fermentation kinetics and aroma compounds of white table wine

    PubMed Central

    Velázquez, Rocío; Zamora, Emiliano; Álvarez, María L.; Hernández, Luis M.; Ramírez, Manuel

    2015-01-01

    Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of wines. However, its impact on wine quality is still far from satisfactory at the winery level, mostly because it is easily replaced by Saccharomyces cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the wine quality score, the S. cerevisiae-dominated wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii–dominated wines, most of the compounds with fresh fruit odor descriptors, including those with the greatest odor activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate), were more abundant in the S. cerevisiae–dominated wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii–dominated wines the low-relative-concentration compounds with dried fruit and pastry odors. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these wines than in those dominated by S. cerevisiae. PMID

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

    PubMed

    Chen, Lei; Huang, Xiaojia

    2016-04-15

    In this study, a new polymeric ionic liquid-based adsorbent was prepared and used as the extraction medium of stir cake sorptive extraction (SCSE) of three organic acid preservatives, namely, p-hydroxybenzoic acid, sorbic acid and cinnamic acid. The adsorbent was synthesized by the copolymerization of 1-ally-3-vinylimidazolium chloride (AV) and divinylbenzene (DVB) in the presence of a porogen solvent containing 1-propanol and 1,4-butanediol. The effect of the content of monomer and the porogen solvent in the polymerization mixture on the extraction performance was investigated thoroughly. The adsorbent was characterized by infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. To obtain the optimal extraction conditions of SCSE/AVDVB for target analytes, key parameters including desorption solvent, adsorption and desorption time, ionic strength and pH value in sample matrix were studied in detail. The results showed that under the optimized conditions, the SCSE/AVDVB could extract the preservatives effectively through multiply interactions. At the same time, a simple and sensitive method by combining SCSE/AVDVB and high-performance liquid chromatography with diode array detection was developed for the simultaneous analysis of the target preservatives in orange juices and tea drinks. Low limits of detection (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target analytes were achieved within the range of 0.012-0.23 μg/L and 0.039-0.42 μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation (RSD), and it was found that the values were all below 10%. Finally, the proposed method was used to detect preservatives in different orange juice and tea drink samples successfully. The recoveries were in the range of 71.9-116%, and the RSDs were below 10% in the all cases.

  18. The same microbiota and a potentially discriminant metabolome in the saliva of omnivore, ovo-lacto-vegetarian and Vegan individuals.

    PubMed

    De Filippis, Francesca; Vannini, Lucia; La Storia, Antonietta; Laghi, Luca; Piombino, Paola; Stellato, Giuseppina; Serrazanetti, Diana I; Gozzi, Giorgia; Turroni, Silvia; Ferrocino, Ilario; Lazzi, Camilla; Di Cagno, Raffaella; Gobbetti, Marco; Ercolini, Danilo

    2014-01-01

    The salivary microbiota has been linked to both oral and non-oral diseases. Scant knowledge is available on the effect of environmental factors such as long-term dietary choices on the salivary microbiota and metabolome. This study analyzed the microbial diversity and metabolomic profiles of the saliva of 161 healthy individuals who followed an omnivore or ovo-lacto-vegetarian or vegan diet. A large core microbiota was identified, including 12 bacterial genera, found in >98% of the individuals. The subjects could be stratified into three "salivary types" that differed on the basis of the relative abundance of the core genera Prevotella, Streptococcus/Gemella and Fusobacterium/Neisseria. Statistical analysis indicated no effect of dietary habit on the salivary microbiota. Phylogenetic beta-diversity analysis consistently showed no differences between omnivore, ovo-lacto-vegetarian and vegan individuals. Metabolomic profiling of saliva using (1)H-NMR and GC-MS/SPME identified diet-related biomarkers that enabled a significant discrimination between the 3 groups of individuals on the basis of their diet. Formate, urea, uridine and 5-methyl-3-hexanone could discriminate samples from omnivores, whereas 1-propanol, hexanoic acid and proline were characteristic of non-omnivore diets. Although the salivary metabolome can be discriminating for diet, the microbiota has a remarkable inter-individual stability and did not vary with dietary habits. Microbial homeostasis might be perturbed with sub-standard oral hygiene or other environmental factors, but there is no current indication that a choice of an omnivore, ovo-lacto-vegetarian or vegan diet can lead to a specific composition of the oral microbiota with consequences on the oral homeostasis.

  19. Time-activity relationships to VOC personal exposure factors

    NASA Astrophysics Data System (ADS)

    Edwards, Rufus D.; Schweizer, Christian; Llacqua, Vito; Lai, Hak Kan; Jantunen, Matti; Bayer-Oglesby, Lucy; Künzli, Nino

    Social and demographic factors have been found to play a significant role in differences between time-activity patterns of population subgroups. Since time-activity patterns largely influence personal exposure to compounds as individuals move across microenvironments, exposure subgroups within the population may be defined by factors that influence daily activity patterns. Socio-demographic and environmental factors that define time-activity subgroups also define quantifiable differences in VOC personal exposures to different sources and individual compounds in the Expolis study. Significant differences in exposures to traffic-related compounds ethylbenzene, m- and p-xylene and o-xylene were observed in relation to gender, number of children and living alone. Categorization of exposures further indicated time exposed to traffic at work and time in a car as important determinants. Increased exposures to decane, nonane and undecane were observed for males, housewives and self-employed. Categorization of exposures indicated exposure subgroups related to workshop use and living downtown. Higher exposures to 3-carene and α-pinene commonly found in household cleaning products and fragrances were associated with more children, while exposures to traffic compounds ethylbenzene, m- and p-xylene and o-xylene were reduced with more children. Considerable unexplained variation remained in categorization of exposures associated with home product use and fragrances, due to individual behavior and product choice. More targeted data collection methods in VOC exposure studies for these sources should be used. Living alone was associated with decreased exposures to 2-methyl-1-propanol and 1-butanol, and traffic-related compounds. Identification of these subgroups may help to reduce the large amount of unexplained variation in VOC exposure studies. Further they may help in assessing impacts of urban planning that result in changes in behavior of individuals, resulting in shifts in

  20. VOC concentrations measured in personal samples and residential indoor, outdoor and workplace microenvironments in EXPOLIS-Helsinki, Finland

    NASA Astrophysics Data System (ADS)

    Edwards, Rufus D.; Jurvelin, J.; Saarela, K.; Jantunen, M.

    Thirty target volatile organic compounds (VOC) were analyzed in personal 48-h exposure samples and residential indoor, residential outdoor and workplace indoor microenvironment samples as a component of EXPOLIS-Helsinki, Finland. Geometric mean residential indoor concentrations were higher than geometric mean residential outdoor concentrations for all target compounds except hexane, which was detected in 40% of residential outdoor samples and 11% of residential indoor samples, respectively. Geometric mean residential indoor concentrations were significantly higher than personal exposure concentrations, which in turn were significantly higher than workplace concentrations for compounds that had strong residential indoor sources ( d-limonene, alpha pinene, 3-carene, hexanal, 2-methyl-1-propanol and 1-butanol). 40% of participants in EXPOLIS-Helsinki reported personal exposure to environmental tobacco smoke (ETS). Participants in Helsinki that were exposed to ETS at any time during the 48-h sampling period had significantly higher personal exposures to benzene, toluene, styrene, m, p-xylene, o-xylene, ethylbenzene and trimethylbenzene. Geometric mean ETS-free workplace concentrations were higher than ETS-free personal exposure concentrations for styrene, hexane and cyclohexane. Geometric mean personal exposures of participants not exposed to ETS were approximately equivalent to time weighted ETS-free indoor and workplace concentrations, except for octanal and compounds associated with traffic, which showed higher geometric mean personal exposure concentrations than any microenvironment ( o-xylene, ethylbenzene,benzene, undecane, nonane, decane, m, p-xylene, and trimethylbenzene). Considerable differences in personal exposure concentrations and residential levels of compounds with mainly indoor sources suggested differences in product types or the frequency of product use between Helsinki, Germany and the United States.

  1. Metabolism of L-methionine linked to the biosynthesis of volatile organic sulfur-containing compounds during the submerged fermentation of Tuber melanosporum.

    PubMed

    Liu, Rui-Sang; Zhou, Huan; Li, Hong-Mei; Yuan, Zhan-Peng; Chen, Tao; Tang, Ya-Jie

    2013-12-01

    Tuber melanosporum, known as the black diamond of cuisine, is highly appreciated for its unique and characteristic aroma, which is mainly due to its volatile organic sulfur-containing compounds (VOSCs). In this work, by adding 5 g/L L-methionine to the fermentation medium, the activities of aminotransferase and α-ketoacid decarboxylase were significantly enhanced by 103 and 250%, respectively, while the activities of alcohol dehydrogenase and demethiolase were decreased by 277 and 39%. Then, the six VOSCs, i.e., methanethiol (MTL), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), 3-(methylthio)propanal (methional), and 3-(methylthio)-1-propanol (methionol), were first detected in the submerged fermentation of T. melanosporum. These results indicated that the biosynthesis of VOSCs was triggered by aminotransferase and α-ketoacid decarboxylase. The production of methional and methionol increased with the increased concentrations of L-methionine (i.e., 5, 10, 15, and 20 g/L) before day 4 of the culture protocol, and methionol was the major product in the Ehrlich pathway. The production of MTL was significantly decreased after day 4 with a significantly increased DMDS, and DMDS was the major product of the demethiolation pathway. Compared with the demethiolation pathway with a total flux of sulfur of 11.33-24.32 μM, the Ehrlich pathway with a total flux of sulfur of 6,149-10,330 μM was considered the major pathway for the biosynthesis of VOSCs. This is the first report linking the metabolism of L-methionine to the biosynthesis of VOSCs by the Ehrlich and demethiolation pathways during the submerged fermentation of T. melanosporum.

  2. Testing of the World Health Organization-recommended formulations for surgical hand preparation and proposals for increased efficacy.

    PubMed

    Suchomel, M; Kundi, M; Allegranzi, B; Pittet, D; Rotter, M L

    2011-10-01

    The 2009 World Health Organization (WHO) Guidelines on hand hygiene in health care recommend alcohol-based hand rubs for both hygienic and pre-surgical hand treatment. Two formulations based on ethanol 80% v/v and 2-propanol 75% v/v are proposed for local preparation in healthcare settings where commercial products are not available or too expensive. Both formulations and our suggested modifications (using mass rather than volume percent concentrations) were evaluated for their conformity with the efficacy requirements of the forthcoming amendment of the European Norm (EN) 12791, i.e. non-inferiority of a product when compared with a reference procedure (1-propanol 60% v/v for 3 min) immediately and 3 h after antisepsis. In this study, the WHO-recommended formulations were tested for 3 min and 5 min. Neither formulation met the efficacy requirements of EN 12791 with 3 min application. Increasing the respective concentrations to 80 w/w (85% v/v) and 75 w/w (80% v/v), together with a prolonged application of 5 min, rendered the immediate effect of both formulations non-inferior to the reference antisepsis procedure. This was not the case with the 3h effect, which remained significantly inferior to the reference. Although the original formulations do not meet the efficacy requirements of EN 12791, the clinical significance of this finding deserves further clinical trials. To comply with the requirement of EN 12791, an amendment to the formulations is possible by increasing the alcohol concentrations through changing volume into mass percent and prolonging the duration of application from 3 min to 5 min.

  3. Construction of self-cloning bottom-fermenting yeast with low vicinal diketone production by the homo-integration of ILV5.

    PubMed

    Kusunoki, K; Ogata, T

    2012-10-01

    The vicinal diketones (VDK), such as diacetyl and 2,3-pentandione, impart an unpleasant butter-like flavour to beer. Typically, these are required to be reduced below the flavour thresholds during the maturation (lagering) stages of the brewing process. To shorten beer maturation time, we constructed a self-cloning, bottom-fermenting yeast with low VDK production by integrating ILV5, a gene encoding a protein that metabolizes α-acetolactate and α-aceto-α-hydroxybutyrate (precursors of VDK). A DNA fragment containing Saccharomyces cerevisiae-type ILV5 was inserted upstream of S. cerevisiae-type ILV2 in bottom-fermenting yeast to construct self-cloning strains with an increased copy number of ILV5. Via transformation, ILV2 was replaced with the sulfometuron methyl (SM) resistance gene SMR1B, which differs by a single nucleotide, to create SM-resistant transformants. The wort fermentation test, using the SC-ILV5-homo inserted transformant, confirmed a consecutive reduction in VDK and a shortening period during which VDK was reduced to within the threshold. The concentrations of ethyl acetate, isoamyl acetate, isoamyl alcohol, 1-propanol, isobutyl alcohol and active isoamyl alcohol (flavour components) were not changed when compared with the parent strain. We successfully constructed self-cloning brewer's yeast in which SC-ILV5 was homo-inserted. Using the transformed yeast, the concentration of VDK in fermenting wort was reduced, whereas the concentrations of flavour components were not affected. This genetically stable, low VDK-producing, self-cloning bottom-fermenting yeast would contribute to the shortening of beer maturation time without affecting important flavour components produced by brewer's yeast. PMID:23038161

  4. Cyanobacterial Blue Color Formation during Lysis under Natural Conditions

    PubMed Central

    Tsuji, Kiyomi; Tomita, Koji; Hasegawa, Masateru; Bober, Beata; Harada, Ken-Ichi

    2015-01-01

    Cyanobacteria produce numerous volatile organic compounds (VOCs), such as β-cyclocitral, geosmin, and 2-methylisoborneol, which show lytic activity against cyanobacteria. Among these compounds, only β-cyclocitral causes a characteristic color change from green to blue (blue color formation) in the culture broth during the lysis process. In August 2008 and September 2010, the lysis of cyanobacteria involving blue color formation was observed at Lake Tsukui in northern Kanagawa Prefecture, Japan. We collected lake water containing the cyanobacteria and investigated the VOCs, such as β-cyclocitral, β-ionone, 1-propanol, 3-methyl-1-butanol, and 2-phenylethanol, as well as the number of cyanobacterial cells and their damage and pH changes. As a result, the following results were confirmed: the detection of several VOCs, including β-cyclocitral and its oxidation product, 2,2,6-trimethylcyclohexene-1-carboxylic acid; the identification of phycocyanin based on its visible spectrum; the lower pH (6.7 and 5.4) of the lysed samples; and characteristic morphological change in the damaged cyanobacterial cells. We also encountered the same phenomenon on 6 September 2013 in Lake Sagami in northern Kanagawa Prefecture and obtained almost the same results, such as blue color formation, decreasing pH, damaged cells, and detection of VOCs, including the oxidation products of β-cyclocitral. β-Cyclocitral derived from Microcystis has lytic activity against Microcystis itself but has stronger inhibitory activity against other cyanobacteria and algae, suggesting that the VOCs play an important role in the ecology of aquatic environments. PMID:25662969

  5. Degradation of vinyl acetate by soil, sewage, sludge, and the newly isolated aerobic bacterium V2.

    PubMed Central

    Nieder, M; Sunarko, B; Meyer, O

    1990-01-01

    Vinyl acetate is subject to microbial degradation in the environment and by pure cultures. It was hydrolyzed by samples of soil, sludge, and sewage at rates of up to 6.38 and 1 mmol/h per g (dry weight) under aerobic and anaerobic conditions, respectively. Four yeasts and thirteen bacteria that feed aerobically on vinyl acetate were isolated. The pathway of vinyl acetate degradation was studied in bacterium V2. Vinyl acetate was degraded to acetate as follows: vinyl acetate + NAD(P)+----2 acetate + NAD(P)H + H+. The acetate was then converted to acetyl coenzyme A and oxidized through the tricarboxylic acid cycle and the glyoxylate bypass. The key enzyme of the pathway is vinyl acetate esterase, which hydrolyzed the ester to acetate and vinyl alcohol. The latter isomerized spontaneously to acetaldehyde and was then converted to acetate. The acetaldehyde was disproportionated into ethanol and acetate. The enzymes involved in the metabolism of vinyl acetate were studied in extracts. Vinyl acetate esterase (Km = 6.13 mM) was also active with indoxyl acetate (Km = 0.98 mM), providing the basis for a convenient spectrophotometric test. Substrates of aldehyde dehydrogenase were formaldehyde, acetaldehyde, propionaldehyde, and butyraldehyde. The enzyme was equally active with NAD+ or NADP+. Alcohol dehydrogenase was active with ethanol (Km = 0.24 mM), 1-propanol (Km = 0.34 mM), and 1-butanol (Km = 0.16 mM) and was linked to NAD+. The molecular sizes of aldehyde dehydrogenase and alcohol dehydrogenase were 145 and 215 kilodaltons, respectively. PMID:2285314

  6. The effect of vehicle on the diffusion of salicylic acid through hairless mouse skin.

    PubMed

    Sloan, K B; Siver, K G; Koch, S A

    1986-08-01

    The solubilities of salicylic acid in, and the fluxes through, hairless mouse skin from isopropyl myristate, 1-octanol, 1-propanol, propylene glycol, and formamide have been determined experimentally. Values for permeability coefficients (Kp) corresponding to the respective fluxes were determined from: flux/solubility = Kp. These values were then compared with values for the respective partition coefficients (P) which were calculated from the known solubility parameters for the vehicles (delta v), salicylic acid (delta i), and skin (delta s). Two different delta i values were used to calculate theoretical P values, one based on the peak solubility method and the other based on calculation from group contributions (11 and 14.4 (cal/cm3)1/2, respectively). There was good correlation between the values for theoretical log P - 1.42 and experimental log Kp for the delivery of salicylic acid from vehicles exhibiting solubility parameters in the range of delta v = 10-18 (cal/cm3)1/2, when delta i was assumed to be 14.4 (cal/cm3)1/2. There was also a good correlation between the values for theoretical log P - 2.09 and experimental log Kp for vehicles exhibiting solubility parameters in the range of delta v = 7.6-10 (cal/cm3)1/2, when delta i was assumed to be 11 (cal/cm3)1/2. Two different delta i values were used because salicylic acid apparently behaves like a polar molecule in polar vehicles and a nonpolar molecule in nonpolar vehicles. Qualitatively, fluxes and permeability coefficients were found to be inversely dependent on drug solubility in the vehicles, with a minimum that corresponded approximately to the point where delta v = delta i, and the minimum within the theoretical P curve.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. Evidence for the existence of an effective interfacial tension between miscible fluids. 2. Dodecyl acrylate-poly(dodecyl acrylate) in a spinning drop tensiometer.

    PubMed

    Zoltowski, Brian; Chekanov, Yuri; Masere, Jonathan; Pojman, John A; Volpert, Vitaly

    2007-05-01

    We studied drops of dodecyl acrylate in poly(dodecyl acrylate) (molecular weight of 25,000) in a spinning drop tensiometer to determine whether an effective interfacial tension (EIT) existed between these two miscible fluids. We found convincing evidence. We estimated the mechanical relaxation time from an immiscible analogue (1-propanol and poly(dodecyl acrylate)) and showed that the dodecyl acrylate drops maintained quasi-steady diameters long after this relaxation period. Drops continuously grew in length and became more diffuse, but the width of the transition zone did not grow with t(1/2) as expected from Fick's law although this system had been shown to follow Fick's law in a static configuration (Antrim, D.; Bunton, P.; Lewis, L. L.; Zoltowski, B. D.; Pojman, J. A. J. Phys. Chem. B 2005, 109, 11842-11849). The EIT was determined from Vonnegut's equation, EIT = (Deltarho)omega(2)r(3)/4; both the inner and outer diameters were measured, yielding values of 0.002 and 0.02 mN m(-1), respectively. The EIT was found to be independent of the rotation rate above 6000 rpm and independent of the initial drop volume. The EIT was found to decrease with temperature and increase with the difference in concentration between the monomer drop and polymer-monomer fluid. The square gradient parameter, k, was determined from EIT = k(Deltac(2)/delta), where Deltac is the difference in mole fraction and delta is the width of the transition zone. The square gradient parameter was on the order of 10(-9) N. The square gradient parameter was found to decrease with temperature, to be independent of concentration, and to increase with the molecular weight of the polymer.

  8. Nonoxidative ethanol metabolism in rabbit myocardium: purification to homogeneity of fatty acyl ethyl ester synthase

    SciTech Connect

    Mogelson, S.; Lange, L.G.

    1984-08-28

    Fatty acyl ethyl esters arise from an esterification of free fatty acids with ethanol in the absence of ATP and coenzyme A. This study was designed to purify the enzyme(s) in rabbit myocardium that catalyze(s) this reaction. Enzyme activity in homogenates of myocardium, as assayed by the rate of synthesis of ethyl (/sup 14/C)oleate from 0.4 mM (/sup 14/C)oleic acid and 0.2 M ethanol, was 31 nmol/ (g x h), and was recovered in the 48400g supernatant. This soluble ethyl ester synthase activity bound to DEAE-cellulose at pH 8, and elution with a NaCl gradient (0-0.25 M0 separated two enzyme activities accounting for 13 and 87% of recovered synthase activity. The major enzyme activity was purified over 5000-fold to homogeneity. Gel electrophoresis showed a single polypeptide with M/sub r/ 26,000, and gel permeation chromatography under nondenaturing conditions indicated a M/sub r/ of 50,000 for the active enzyme. Kinetic analyses indicated that greatest rates of synthesis were observed with unsaturated octadecanoic fatty acid substrates. K/sub m/'s for these fatty acids were essentially identical and equal to 0.2 mM; substrate specificity resulted from varying K/sub m/'s for methanol, ethanol, 1-propanol, and 1-butanol, while V/sub max/ was constant at approximately 1.5 nmol/(mg x s). The amino acid analysis of this synthase distinguishes it from typical cholesterol esterases. When the enzyme is maximally active with respect to ethyl ester synthesis, it does not hydrolyze cholesterol oleate. Fatty acid ethyl esters are synthesized in myocardium primarily by a soluble dimeric enzyme comprised of two nearly identical subunits which esterifies free fatty acids with ethanol to produce a nonoxidative metabolite.

  9. Ion Mobility-Mass Spectrometry Reveals the Energetics of Intermediates that Guide Polyproline Folding

    NASA Astrophysics Data System (ADS)

    Shi, Liuqing; Holliday, Alison E.; Glover, Matthew S.; Ewing, Michael A.; Russell, David H.; Clemmer, David E.

    2016-01-01

    Proline favors trans-configured peptide bonds in native proteins. Although cis/ trans configurations vary for non-native and unstructured states, solvent also influences these preferences. Water induces the all- cis right-handed polyproline-I (PPI) helix of polyproline to fold into the all- trans left-handed polyproline-II (PPII) helix. Our recent work has shown that this occurs via a sequential mechanism involving six resolved intermediates [Shi, L., Holliday, A.E., Shi, H., Zhu, F., Ewing, M.A., Russell, D.H., Clemmer, D.E.: Characterizing intermediates along the transition from PPI to PPII using ion mobility-mass spectrometry. J. Am. Chem. Soc. 136, 12702-12711 (2014)]. Here, we use ion mobility-mass spectrometry to make the first detailed thermodynamic measurements of the folding intermediates, which inform us about how and why this transition occurs. It appears that early intermediates are energetically favorable because of the hydration of the peptide backbone, whereas late intermediates are enthalpically unfavorable. However, folding continues, as the entropy of the system increases upon successive formation of each new structure. When PPII is immersed in 1-propanol, the PPII→PPI transition occurs, but this reaction occurs through a very different mechanism. Early on, the PPII population splits onto multiple pathways that eventually converge through a late intermediate that continues on to the folded PPI helix. Nearly every step is endothermic. Folding results from a stepwise increase in the disorder of the system, allowing a wide-scale search for a critical late intermediate. Overall, the data presented here allow us to establish the first experimentally determined energy surface for biopolymer folding as a function of solution environment.

  10. Ion Mobility-Mass Spectrometry Reveals the Energetics of Intermediates that Guide Polyproline Folding.

    PubMed

    Shi, Liuqing; Holliday, Alison E; Glover, Matthew S; Ewing, Michael A; Russell, David H; Clemmer, David E

    2016-01-01

    Proline favors trans-configured peptide bonds in native proteins. Although cis/trans configurations vary for non-native and unstructured states, solvent also influences these preferences. Water induces the all-cis right-handed polyproline-I (PPI) helix of polyproline to fold into the all-trans left-handed polyproline-II (PPII) helix. Our recent work has shown that this occurs via a sequential mechanism involving six resolved intermediates [Shi, L., Holliday, A.E., Shi, H., Zhu, F., Ewing, M.A., Russell, D.H., Clemmer, D.E.: Characterizing intermediates along the transition from PPI to PPII using ion mobility-mass spectrometry. J. Am. Chem. Soc. 136, 12702-12711 (2014)]. Here, we use ion mobility-mass spectrometry to make the first detailed thermodynamic measurements of the folding intermediates, which inform us about how and why this transition occurs. It appears that early intermediates are energetically favorable because of the hydration of the peptide backbone, whereas late intermediates are enthalpically unfavorable. However, folding continues, as the entropy of the system increases upon successive formation of each new structure. When PPII is immersed in 1-propanol, the PPII→PPI transition occurs, but this reaction occurs through a very different mechanism. Early on, the PPII population splits onto multiple pathways that eventually converge through a late intermediate that continues on to the folded PPI helix. Nearly every step is endothermic. Folding results from a stepwise increase in the disorder of the system, allowing a wide-scale search for a critical late intermediate. Overall, the data presented here allow us to establish the first experimentally determined energy surface for biopolymer folding as a function of solution environment. PMID:26362047

  11. Quantification of melamine in drinking water and wastewater by micellar liquid chromatography.

    PubMed

    Beltrán-Martinavarro, Beatriz; Peris-Vicente, Juan; Rambla-Alegre, Maria; Marco-Peiró, Sergio; Esteve-Romero, Josep; Carda-Broch, Samuel

    2013-01-01

    Because of the large potential health impact caused by deliberate contamination with the synthetic chemical melamine of different products for human and animal consumption, the World Health Organization and the Food and Agriculture Organization of the United Nations provided a range of recommendations in order to facilitate obtaining needed data, among which was the determination of the background levels of melamine in drinking water and wastewater (December 4, 2008). A chromatographic procedure using a C18 column, a micellar mobile phase consisting of sodium dodecyl sulfate (0.1 M), and 1-propanol (7.5%) buffered at pH 3, and detection by absorbance at 210 nm is reported in this paper for the quantification of melamine in drinking water and wastewater. Samples were filtered and directly injected into the chromatographic system, thus avoiding an extraction procedure. The optimal mobile phase composition was obtained by a chemometrics approach that considered the retention factor, efficiency, and peak shape. Melamine was eluted in about 6.2 min without interferences. Validation was performed following U.S. Food and Drug Administration guidelines. The analytical parameters studied were linearity (0.03-5 microg/mL, R2 = 0.998), LOD (13 nglmL), intraday and interday accuracy (between 4.1 and 12.2%), intraday and interday precision (less than 14.8%), and robustness (RSD < 5.1% for retention time and <9.0% for area). The proposed methodology was successfully applied for analysis of local wastewater and drinking water, in which no melamine was found.

  12. An ATR-FTIR Study on the Effect of Molecular Structural Variations on the CO2 Absorption Characteristics of Heterocyclic Amines, Part II

    PubMed Central

    Robinson, Kelly; McCluskey, Adam; Attalla, Moetaz I

    2012-01-01

    This paper reports on an ATR-FTIR spectroscopic investigation of the CO2 absorption characteristics of a series of heterocyclic diamines: hexahydropyrimidine (HHPY), 2-methyl and 2,2-dimethylhexahydropyrimidine (MHHPY and DMHHPY), hexahydropyridazine (HHPZ), piperazine (PZ) and 2,5- and 2,6-dimethylpiperazine (2,6-DMPZ and 2,5-DMPZ). By using in situ ATR-FTIR the structure–activity relationship of the reaction between heterocyclic diamines and CO2 is probed. PZ forms a hydrolysis-resistant carbamate derivative, while HHPY forms a more labile carbamate species with increased susceptibility to hydrolysis, particularly at higher CO2 loadings (>0.5 mol CO2/mol amine). HHPY exhibits similar reactivity toward CO2 to PZ, but with improved aqueous solubility. The α-methyl-substituted MHHPY favours HCO3− formation, but MHHPY exhibits comparable CO2 absorption capacity to conventional amines MEA and DEA. MHHPY show improved reactivity compared to the conventional α-methyl- substituted primary amine 2-amino-2-methyl-1-propanol. DMHHPY is representative of blended amine systems, and its reactivity highlights the advantages of such systems. HHPZ is relatively unreactive towards CO2. The CO2 absorption capacity CA (mol CO2/mol amine) and initial rates of absorption RIA (mol CO2/mol amine min−1) for each reactive diamine are determined: PZ: CA=0.92, RIA=0.045; 2,6-DMPZ: CA=0.86, RIA=0.025; 2,5-DMPZ: CA=0.88, RIA=0.018; HHPY: CA=0.85, RIA=0.032; MHHPY: CA=0.86, RIA=0.018; DMHHPY: CA=1.1, RIA=0.032; and HHPZ: no reaction. Calculations at the B3LYP/6-31+G** and MP2/6-31+G** calculations show that the substitution patterns of the heterocyclic diamines affect carbamate stability, which influences hydrolysis rates. PMID:22517608

  13. Study of the art: canine olfaction used for cancer detection on the basis of breath odour. Perspectives and limitations.

    PubMed

    Jezierski, Tadeusz; Walczak, Marta; Ligor, Tomasz; Rudnicka, Joanna; Buszewski, Bogusław

    2015-05-06

    Experimental studies using trained dogs to identify breath odour markers of human cancer, published in the recent decade, have been analyzed and compared with the authors' own results. Particular published studies differ as regards the experimental setup, kind of odour samples (breath, urine, tumor tissue, serum), sample collection methods, dogs' characteristics and dog training methods as well as in results presented in terms of detection sensitivity and specificity. Generally it can be stated that trained dogs are able to distinguish breath odour samples typical for patients with lung cancer and other cancers from samples typical for healthy humans at a 'better than by chance' rate. Dogs' indications were positively correlated with content of 2-pentanone and ethyl acetate (r = 0.97 and r = 0.85 respectively) and negatively correlated with 1-propanol and propanal in breath samples (r = -0.98 and -0.87 respectively). The canine method has some advantages as a potential cancer-screening method, due to its non-invasiveness, simplicity of odour sampling and storage, ease of testing and interpretation of results and relatively low costs. Disadvantages and limitations of this method are related to the fact that it is still not known exactly to which chemical compounds and/or their combinations the dogs react. So far it could not be confirmed that dogs are able to sniff out early preclinical cancer stages with approximately the same accuracy as already diagnosed cases. The detection accuracy may vary due to failure in conditioning of dogs, decreasing motivation or confounding factors. The dogs' performance should be systematically checked in rigorous double-blind procedures. Recommendations for methodological standardization have been proposed.

  14. Separation of total lipids on human lipoproteins using surfactant-coated multiwalled carbon nanotubes as pseudostationary phase in capillary electrophoresis.

    PubMed

    Su, Mei-Yu; Chen, Yen-Yi; Yang, Jian-Ying; Lin, You-Sian; Lin, Yang-Wei; Liu, Mine-Yine

    2014-04-01

    Surfactant-coated multiwalled carbon nanotubes (MWNTs) were used as pseudostationary phase (PSP) in CE to investigate the total lipids of high-density lipoproteins and low-density lipoproteins. To optimize the CE conditions, several experimental factors including carbon nanotube concentration, bile salt concentration, sodium phosphate (PB) concentration, organic modifier concentration and buffer pH value have been examined. In addition, the CE capillary temperature and applied voltage have also been examined. The optimal separation buffer selected was a mixture of 3.2 mg/L MWNT, 50 mM bile salt, 10 mM PB, 20% 1-propanol, pH 9.5. The optimal capillary temperature and applied voltage selected were 50°C and 20 kV, respectively. Phosphatidyl choline (PC) has been used as a model analyte and investigated by the optimal CE method. The linear range for PC was 0.1-3 mg/mL with a correlation coefficient of 0.9934, and the concentration LOD was 0.055 mg/mL. The optimal CE method has been used to characterize the total lipids of high-density lipoprotein and low-density lipoprotein. At absorbance 200 nm, one major peak and two or three minor peaks showed for the total lipids of lipoproteins within 13 minutes. Resolutions of the total lipids were enhanced using surfactant-coated MWNTs as PSPs in the CE separation buffer. However, resolutions of the total lipids were not enhanced using surfactant-coated single-walled carbon nanotubes as PSPs in the CE separation buffer.

  15. Effect of organic solvents on J aggregation of pseudoisocyanine dye at mica/water interfaces: morphological transition from three-dimension to two-dimension.

    PubMed

    Yao, Hiroshi; Morita, Yoshinobu; Kimura, Keisaku

    2008-02-01

    Morphological and spectroscopic properties of pseudoisocyanine (PIC) J aggregates produced at mica/solution interfaces have been characterized by absorption/fluorescence spectroscopy, fluorescence microscopy, and atomic force microscopy. Addition of organic solvents (1-propanol (PrOH) or 1,4-dioxane (Dox)) into aqueous solutions of the PIC dye induced a transition of the morphology of the interfacial J aggregates. The characteristic feature of this transition is the thickness (or height) change of the aggregate domain layers from three-dimensions to two-dimensions: The domain area of the J aggregates was dependent on the amount of the organic cosolvent, while the domain thickness was dependent on the type of the cosolvent. In pure aqueous solution, the J aggregates at the mica/water interface had a three-dimensional structure with the height of approximately 3 nm (multilayer structure). In mixed solvents of PrOH/water or Dox/water (5 or 10 vol%), the interfacial aggregates became a bilayer or monolayer structure, respectively, assuming that PIC molecules are adsorbed on their molecular plane perpendicular to the mica surface. Meanwhile, optical properties (band width and peak position) of the J band were invariant upon addition of the organic cosolvents, suggesting that molecular packing in the J aggregates is essentially unchanged. These results revealed that spectroscopic properties of the interfacial PIC J aggregates were determined only by the lateral (two-dimensional) interaction within the adsorbed monolayer of PIC molecules on mica, and interlayer interaction in the multilayered J aggregate was consequently small. PMID:17963780

  16. Thermodynamic Stability Analysis of Tolbutamide Polymorphs and Solubility in Organic Solvents.

    PubMed

    Svärd, Michael; Valavi, Masood; Khamar, Dikshitkumar; Kuhs, Manuel; Rasmuson, Åke C

    2016-06-01

    Melting temperatures and enthalpies of fusion have been determined by differential scanning calorimetry (DSC) for 2 polymorphs of the drug tolbutamide: FI(H) and FV. Heat capacities have been determined by temperature-modulated DSC for 4 polymorphs: FI(L), FI(H), FII, FV, and for the supercooled melt. The enthalpy of fusion of FII at its melting point has been estimated from the enthalpy of transition of FII into FI(H) through a thermodynamic cycle. Calorimetric data have been used to derive a quantitative polymorphic stability relationship between these 4 polymorphs, showing that FII is the stable polymorph below approximately 333 K, above which temperature FI(H) is the stable form up to its melting point. The relative stability of FV is well below the other polymorphs. The previously reported kinetic reversibility of the transformation between FI(L) and FI(H) has been verified using in situ Raman spectroscopy. The solid-liquid solubility of FII has been gravimetrically determined in 5 pure organic solvents (methanol, 1-propanol, ethyl acetate, acetonitrile, and toluene) over the temperature range 278 to 323 K. The ideal solubility has been estimated from calorimetric data, and solution activity coefficients at saturation in the 5 solvents determined. All solutions show positive deviation from Raoult's law, and all van't Hoff plots of solubility data are nonlinear. The solubility in toluene is well below that observed in the other investigated solvents. Solubility data have been correlated and extrapolated to the melting point using a semiempirical regression model. PMID:27238487

  17. Antioxidation Properties and Surface Interactions of Polyvinylpyrrolidone-Capped Zerovalent Copper Nanoparticles Synthesized in Supercritical Water.

    PubMed

    Morioka, Takuya; Takesue, Masafumi; Hayashi, Hiromichi; Watanabe, Masaru; Smith, Richard L

    2016-01-27

    Zerovalent copper nanoparticles (CuNPs) (diameter, 26.5 ± 9 nm) capped with polyvinylpyrrolidone (PVP) were synthesized in supercritical water at 400 °C and 30 MPa with a continuous flow reactor. The PVP-capped CuNPs were dispersed in distilled water, methanol, ethanol, 1-propanol, 2-propanol, butanol, and their mixed solvents to study their long-term stability. Temporal variation of UV-vis spectra and surface plasmon resonance were measured and showed that ethanol, the propanols, and butanol solvents provided varying degrees of oxidative protection for Cu(0). Fourier transform infrared spectroscopy showed that PVP adsorbed onto the surface of the CuNPs with a pyrrolidone ring of PVP even if the CuNPs were oxidized. Intrinsic viscosities of PVP were higher for solvents that provided antioxidation protection than those that give oxidized CuNPs. In solvents that provided Cu(0) with good oxidative protection (ethanol, the propanols, and butanol), PVP polymer chains formed large radii of gyration and coil-like conformations in the solvents so that they were arranged uniformly and orderly on the surface of the CuNPs and could provide protection of the Cu(0) surface against dissolved oxygen. In solvents that provided poor oxidative protection for Cu(0) (water, alcohol-water mixed solvents with 30% water), PVP polymer chains had globular-like conformations due to their relatively high hydrogen-bonding interactions and sparse adsorption onto the CuNP surface. Antioxidative properties of PVP-capped CuNPs in a solvent can be ascribed to the conformation of PVP polymer chains on the Cu(0) particle surface that originates from the interaction between polymer chains and its interaction with the solvent. PMID:26716468

  18. Ruminal Fermentation of Anti-Methanogenic Nitrate- and Nitro-Containing Forages In Vitro.

    PubMed

    Anderson, Robin C; Ripley, Laura H; Bowman, Jan G P; Callaway, Todd R; Genovese, Kenneth J; Beier, Ross C; Harvey, Roger B; Nisbet, David J

    2016-01-01

    Nitrate, 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if consumed in high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied little in this regard. Presently, we found that nitrate-, NPA-, or NPOH-containing forages effectively decreased methane production, by 35-87%, during in vitro fermentation by mixed cultures of ruminal microbes compared to fermentation by cultures incubated similarly with alfalfa. Methane production was further decreased during the incubation of mixed cultures also inoculated with Denitrobacterium detoxificans, a ruminal bacterium known to metabolize nitrate, NPA, and NPOH. Inhibition of methanogens within the mixed cultures was greatest with the NPA- and NPOH-containing forages. Hydrogen accumulated in all the mixed cultures incubated with forages containing nitrate, NPA or NPOH and was dramatically higher, exceeding 40 μmol hydrogen/mL, in mixed cultures incubated with NPA-containing forage but not inoculated with D. detoxificans. This possibly reflects the inhibition of hydrogenase-catalyzed uptake of hydrogen produced via conversion of 50 μmol added formate per milliliter to hydrogen. Accumulations of volatile fatty acids revealed compensatory changes in fermentation in mixed cultures incubated with the nitrate-, NPA-, and NPOH-containing forages as evidenced by lower accumulations of acetate, and in some cases, higher accumulations of butyrate and lower accumulations of ammonia, iso-buytrate, and iso-valerate compared to cultures incubated with alfalfa. Results reveal that nitrate, NPA, and NPOH that accumulate naturally in forages can be made available within ruminal incubations to inhibit methanogenesis. Further research is warranted to determine if diets can be formulated with nitrate-, NPA-, and NPOH-containing forages to achieve efficacious mitigation in

  19. Thermodynamical and structural properties of binary mixtures of imidazolium chloride ionic liquids and alcohols from molecular simulation

    NASA Astrophysics Data System (ADS)

    Raabe, Gabriele; Köhler, Jürgen

    2008-10-01

    We have performed molecular dynamics simulations to determine the densities, excess energies of mixing, and structural properties of binary mixtures of the 1-alkyl-3-methylimidazolium chloride ionic liquids (ILs) [amim][Cl] and ethanol and 1-propanol in the temperature range from 298.15to363.15K. As in our previous work [J. Chem. Phys. 128, 154509 (2008)], our simulation studies are based on a united atom model from Liu et al. [Phys. Chem. Chem. Phys. 8, 1096 (2006)] for the 1-ethyl- and 1-butyl-3-methylimidazolium cations [emim+] and [bmim+], which we have extended to the 1-hexyl-3-methylimidazolium [hmim+] cation and combined with parameters of Canongia Lopes et al. [J. Phys. Chem. B 108, 2038 (2004)] for the chloride anion [Cl-] and the force field by Khare et al. for the alcohols [J. Phys. Chem. B 108, 10071 (2004)]. With this, we provide both prediction for the densities of the mixtures that have mostly not been investigated experimentally yet and a molecular picture of the interactions between the alcohol molecules and the ions. The negative excess energies of all mixtures indicate an energetically favorable mixing of [amim][Cl] ILs and alcohols. To gain insight into the nonideality of the mixtures on the molecular level, we analyzed their local structures by radial and spatial distribution functions. These analyses show that the local ordering in these mixtures is determined by strong hydrogen-bond interactions between the chloride anion and the hydroxyls of the alcohols, enhanced interactions between the anion and the charged domain of the cation, and an increasing aggregation of the nonpolar alkyl tails of the alcohols and the cations with increasing cation size, which results in a segregation of polar and nonpolar domains.

  20. Effects of new Torulaspora delbrueckii killer yeasts on the must fermentation kinetics and aroma compounds of white table wine.

    PubMed

    Velázquez, Rocío; Zamora, Emiliano; Álvarez, María L; Hernández, Luis M; Ramírez, Manuel

    2015-01-01

    Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of wines. However, its impact on wine quality is still far from satisfactory at the winery level, mostly because it is easily replaced by Saccharomyces cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the wine quality score, the S. cerevisiae-dominated wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii-dominated wines, most of the compounds with fresh fruit odor descriptors, including those with the greatest odor activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate), were more abundant in the S. cerevisiae-dominated wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii-dominated wines the low-relative-concentration compounds with dried fruit and pastry odors. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these wines than in those dominated by S. cerevisiae.

  1. Towards the rational design of organic/inorganic interface for solid supported CO2 capture

    NASA Astrophysics Data System (ADS)

    He, Feng

    Monoethanolamine (MEA, HO(CH2)2NH2) aqueous solution based CO2 capture is the current technology used to mitigate power plants' green house gas emission. Solid based CO2 capture technique is regarded as a promising alternative, because it is more cost-effective and environmentally friendly than the solution based technique. Recently, solid-supported CO2 capture on MEA modified TiO 2 powders has been demonstrated [1]. It is believed that the main reaction pathway involved in solid-supported amine based CO2 capture is similar to the reaction in the amine solution, where the amine group reacts with CO2 to form carbamate (--NHCOO--). From the previous work on the MEA/TiO2 (110) system [2], it is found that MEA covered rutile TiO2 (110) did not capture CO 2. The main reaction pathway in this system was blocked because the amine group attached to the surface. In order to design a functional system, we proposed two possible mechanisms to free --NH2 from rutile TiO2 (110) surface. In this work, we investigated one of our six candidates, the 3-Amino-1-propanol (3AP, HO(CH2) 3NH2) molecule. The classical reactive force field (ReaxFF) [3] method has been employed to investigate the 3AP/TiO2 (110) system with emphasis on binding configurations and binding energies. We found that the amine group of 3AP did not attach to the rutile TiO2 (110) surface, indicating the CO2 capture capability of the 3AP/TiO 2 (110) system, which was confirmed by our experimental collaborators [4].

  2. Development and validation of an analytical method for the separation and determination of major bioactive curcuminoids in Curcuma longa rhizomes and herbal products using non-aqueous capillary electrophoresis.

    PubMed

    Anubala, S; Sekar, R; Nagaiah, K

    2014-06-01

    A simple, fast and efficient non-aqueous capillary electrophoresis method (NACE) was developed for the simultaneous determination of three major bioactive curcuminoids (CMNs) in Curcuma longa rhizomes and its herbal products. Good separation, resolution and reproducibility were achieved with the background electrolyte (BGE) consisting a mixture of 15.0 mM sodium tetraborate and 7.4 mM sodium hydroxide (NaOH) in 2:10:15 (v/v/v) of water, 1-propanol, and methanol. The influences of background electrolyte, sodium hydroxide, water, sodium dodecyl sulfate and hydroxylpropyl-β-cyclodextrin on separations were investigated. The separation was carried out in a fused-silica capillary tube with reverse polarity. Hydrodynamic injection of 25mbar for 12s was used for injecting samples and a voltage of 28 kV was applied for separation. The ultrasonication method was used for the extraction of CMNs from the turmeric herbal products and the extract was filtered and directly injected without any further treatments. The limits of detection and quantification were less than 5.0 and 14.6 µg/ml respectively for all CMNs. The percentage recoveries for CMNs were >97.2% (%RSD, <2.62). The results obtained by the method were compared with existing spectrophotometric and HPLC methods. The related compounds in the extract did not interfere in the determination of CMNs. The proposed NACE method is better than existing chromatographic and electrophoretic methods in terms of simple electrophoretic medium, fast analysis and good resolution.

  3. Alcohol metabolism by oral streptococci and interaction with human papillomavirus leads to malignant transformation of oral keratinocytes.

    PubMed

    Tao, Lin; Pavlova, Sylvia I; Gasparovich, Stephen R; Jin, Ling; Schwartz, Joel

    2015-01-01

    Poor oral hygiene, ethanol consumption, and human papillomavirus (HPV) are associated with oral and esophageal cancers. However, the mechanism is not fully known. This study examines alcohol metabolism in Streptococcus and its interaction with HPV-16 in the malignant transformation of oral keratinocytes. The acetaldehyde-producing strain Streptococcus gordonii V2016 was analyzed for adh genes and activities of alcohol and aldehyde dehydrogenases. Streptococcus attachment to immortalized HPV-16 infected human oral keratinocytes, HOK (HPV/HOK-16B), human oral buccal keratinocytes, and foreskin keratinocytes was studied. Acetaldehyde, malondialdehyde, DNA damage, and abnormal proliferation among keratinocytes were also quantified. We found that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB, and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol, and ethanol, respectively. S. gordonii V2016 did not show a detectable aldehyde dehydrogenase. AdhE is the major alcohol dehydrogenase in S. gordonii. Acetaldehyde and malondialdehyde production from permissible Streptococcus species significantly increased the bacterial attachment to keratinocytes, which was associated with an enhanced expression of furin to facilitate HPV infection and several malignant phenotypes including acetaldehyde adduct formation, abnormal proliferation, and enhanced migration through integrin-coated basement membrane by HPV-infected oral keratinocytes. Therefore, expression of multiple alcohol dehydrogenases with no functional aldehyde dehydrogenase contributes to excessive production of acetaldehyde from ethanol by oral streptococci. Oral Streptococcus species and HPV may cooperate to transform oral keratinocytes after ethanol exposure. These results suggest a significant clinical interaction, but further validation is warranted. PMID:25427911

  4. Ruminal Fermentation of Anti-Methanogenic Nitrate- and Nitro-Containing Forages In Vitro

    PubMed Central

    Anderson, Robin C.; Ripley, Laura H.; Bowman, Jan G. P.; Callaway, Todd R.; Genovese, Kenneth J.; Beier, Ross C.; Harvey, Roger B.; Nisbet, David J.

    2016-01-01

    Nitrate, 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) can accumulate in forages and be poisonous to animals if consumed in high enough amounts. These chemicals are also recognized as potent anti-methanogenic compounds, but plants naturally containing these chemicals have been studied little in this regard. Presently, we found that nitrate-, NPA-, or NPOH-containing forages effectively decreased methane production, by 35–87%, during in vitro fermentation by mixed cultures of ruminal microbes compared to fermentation by cultures incubated similarly with alfalfa. Methane production was further decreased during the incubation of mixed cultures also inoculated with Denitrobacterium detoxificans, a ruminal bacterium known to metabolize nitrate, NPA, and NPOH. Inhibition of methanogens within the mixed cultures was greatest with the NPA- and NPOH-containing forages. Hydrogen accumulated in all the mixed cultures incubated with forages containing nitrate, NPA or NPOH and was dramatically higher, exceeding 40 μmol hydrogen/mL, in mixed cultures incubated with NPA-containing forage but not inoculated with D. detoxificans. This possibly reflects the inhibition of hydrogenase-catalyzed uptake of hydrogen produced via conversion of 50 μmol added formate per milliliter to hydrogen. Accumulations of volatile fatty acids revealed compensatory changes in fermentation in mixed cultures incubated with the nitrate-, NPA-, and NPOH-containing forages as evidenced by lower accumulations of acetate, and in some cases, higher accumulations of butyrate and lower accumulations of ammonia, iso-buytrate, and iso-valerate compared to cultures incubated with alfalfa. Results reveal that nitrate, NPA, and NPOH that accumulate naturally in forages can be made available within ruminal incubations to inhibit methanogenesis. Further research is warranted to determine if diets can be formulated with nitrate-, NPA-, and NPOH-containing forages to achieve efficacious mitigation

  5. Aerobic MTBE biodegradation: an examination of past studies, current challenges and future research directions.

    PubMed

    Deeb, R A; Scow, K M; Alvarez-Cohen, L

    2000-01-01

    With the current practice of amending gasoline with up to 15% by volume MTBE, the contamination of groundwater by MTBE has become widespread. As a result, the bioremediation of MTBE-impacted aquifers has become an active area of research. A review of the current literature on the aerobic biodegradation of MTBE reveals that a number of cultures from diverse environments can either partially degrade or completely mineralize MTBE. MTBE is either utilized as a sole carbon and energy source or is degraded cometabolically by cultures grown on alkanes. Reported degradation rates range from 0.3 to 50 mg MTBE/g cells/h while growth rates (0.01-0.05 g MTBE/g cells/d) and cellular yields (0.1-0.2 g cells/g MTBE) are generally low. Studies on the mechanisms of MTBE degradation indicate that a monooxygenase enzyme cleaves the ether bond yielding tert-butyl alcohol (TBA) and formaldehyde as the dominant detectable intermediates. TBA is further degraded to 2-methyl-2-hydroxy-1-propanol, 2-hydroxyisobutyric acid, 2-propanol, acetone, hydroxyacteone and eventually, carbon dioxide. The majority of these intermediates are also common to mammalian MTBE metabolism. Laboratory studies on the degradation of MTBE in the presence of gasoline aromatics reveal that while degradation rates of other gasoline components are generally not inhibited by MTBE, MTBE degradation could be inhibited in the presence of more easily biodegradable compounds. Controlled field studies are clearly needed to elucidate MTBE degradation potential in co-contaminant plumes. Based on the reviewed studies, it is likely that a bioremediation strategy involving direct metabolism, cometabolism, bioaugmentation, or some combination thereof, could be applied as a feasible and cost-effective treatment method for MTBE contamination.

  6. ELISA assays and alcohol: increasing carbon chain length can interfere with detection of cytokines.

    PubMed

    von Maltzan, Kristine; Pruett, Stephen B

    2011-02-01

    Enzyme-linked immunosorbent assays (ELISAs) are frequently used in studies on cytokine production in response to treatment of cell cultures or laboratory animals. When an ELISA assay is performed on cell culture supernatants, samples often contain the treatment agents. The purpose of the present study was to determine if some of the agents evaluated might inhibit cytokine detection by interfering with the ELISA, leaving the question of whether cytokine production was inhibited unanswered. Mouse and human cytokine ELISA kits from BD Biosciences were used according to the manufacturer's instructions. Cytokine proteins were subjected to one to five carbon alcohols at 86.8mM (methanol, ethanol, 1-propanol, 2-propanol, n-butanol, and n-pentanol). After treating cell cultures with alcohols of different carbon chain lengths, we found that some of the alcohols interfered with measurement of some cytokines by ELISA, thus making their effects on cytokine production by cells in culture unclear. Increasing carbon chain length of straight chain alcohols positively correlated with their ability to inhibit detection of tumor necrosis factor alpha (TNF-α) and interleukin 10 (IL-10), but not with the detection of interleukin 6 (IL-6), interleukin 8, (IL-8), and interleukin 12 (IL-12). To avoid misinterpretation of treatment effects, ELISA assays should be tested with the reference protein and the treatment agent first, before testing biological samples. These results along with other recent results we obtained using circular dichroism indicate that alcohols with two or more carbons can directly alter protein conformation enough to disrupt binding in an ELISA (shown in the present study) or to inhibit ligand-induced conformational changes (results not shown). Such direct effects have not been given enough consideration as a mechanism of ethanol action in the immune system.

  7. Multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase causing excessive acetaldehyde production from ethanol by oral streptococci.

    PubMed

    Pavlova, Sylvia I; Jin, Ling; Gasparovich, Stephen R; Tao, Lin

    2013-07-01

    Ethanol consumption and poor oral hygiene are risk factors for oral and oesophageal cancers. Although oral streptococci have been found to produce excessive acetaldehyde from ethanol, little is known about the mechanism by which this carcinogen is produced. By screening 52 strains of diverse oral streptococcal species, we identified Streptococcus gordonii V2016 that produced the most acetaldehyde from ethanol. We then constructed gene deletion mutants in this strain and analysed them for alcohol and acetaldehyde dehydrogenases by zymograms. The results showed that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol and ethanol, respectively. Two additional dehydrogenases, S-AdhA and TdhA, were identified with specificities to the secondary alcohol 2-propanol and threonine, respectively, but not to ethanol. S. gordonii V2016 did not show a detectable acetaldehyde dehydrogenase even though its adhE gene encodes a putative bifunctional acetaldehyde/alcohol dehydrogenase. Mutants with adhE deletion showed greater tolerance to ethanol in comparison with the wild-type and mutant with adhA or adhB deletion, indicating that AdhE is the major alcohol dehydrogenase in S. gordonii. Analysis of 19 additional strains of S. gordonii, S. mitis, S. oralis, S. salivarius and S. sanguinis showed expressions of up to three alcohol dehydrogenases, but none showed detectable acetaldehyde dehydrogenase, except one strain that showed a novel ALDH. Therefore, expression of multiple alcohol dehydrogenases but no functional acetaldehyde dehydrogenase may contribute to excessive production of acetaldehyde from ethanol by certain oral streptococci.

  8. Preparation of an adsorbent based on polymeric ionic liquid for the simultaneous extraction of acidic, basic and neutral pollutants.

    PubMed

    Chen, Lei; Huang, Xiaojia

    2016-09-30

    In this study, coextraction of acidic, basic and neutral pollutants was realized with a new adsorbent based on polymeric ionic liquid (PIL). In the presence of a porogen solvent containing 1-propanol and 1,4-butanediol, an ionic liquid, 1-vinyl-3-octylimidazolium tetrafluoraborate was used as monomer to copolymerize with dual cross-linkers (divinylbenzene and N,N-methylene-bisacrylamide) to form the adsorbent for stir cake sorptive extraction (SCSE). Phenols, aromatic amines and parabens were selected as acidic, basic and neutral model analytes, respectively. The effects of preparation conditions and extraction parameters on the extraction performance of SCSE/PIL were investigated thoroughly. Under the optimized conditions, the prepared adsorbent showed satisfactory coextraction performance to the selected analytes with multiply interactions. At the same time, simple and sensitive analytical method for simultaneous determination of phenols, aromatic amines and parabens in environmental water samples was developed by the combination of SCSE/PIL with high-performance liquid chromatography with diode array detection. Low limits of detection (S/N=3) and quantification limits (S/N=10) of the proposed method for the targeted analytes were achieved within the range of 0.064-0.30μg/L and 0.21-0.99μg/L, respectively. The precision of the proposed method was evaluated in terms of intra- and inter-assay variability calculated as relative standard deviation (RSD), and it was found that the RSD values were all below 10%. Ultimately, the applicability of developed method was successfully confirmed by analyzing lake, reservoir and river water samples. Recoveries obtained for the determination of targeted analytes in spiking samples ranged from 70.0% to 112%, with RSDs within the range of 1.6-9.8%. PMID:27613147

  9. Influence of Sol-Gel Conditions on the Growth of Thiol-Functionalized Silsesquioxanes Prepared by In Situ Water Production.

    PubMed

    Borovin, Evgeny; Callone, Emanuela; Papendorf, Benjamin; Guella, Graziano; Diré, Sandra

    2016-03-01

    Thiol-functionalized oligosilsesquioxanes have been synthesized by sol-gel chemistry via the in-situ water production (ISWP) approach, exploiting the esterification reaction of chloro-acetic acid and 1-propanol. The extent of hydrolysis-condensation of 3-Mercaptopropyltrimethoxysilane (McPTMS) has been studied by FT-IR and NMR spectroscopy, gel permeation chromatography (GPC) and MALDI-TOF techniques. The esterification reaction plays a key role in ruling out the oligomer structural development. In this work, we have investigated the influence of the theoretical amount of water available for the organosilane hydrolysis, defined by the ratio of chloro-acetic acid to McPTMS in the reaction mixture, and the role of different catalysts like trifluoroacetic acid (TFA) and dibutyldilauryltin (DBTL). The behavior of the catalyst is complex since, according to its nature, it may improve the kinetics of the sol-gel reactions and the esterification reaction as well. Comparing the reactions carried out with under-stoichiometric water content, the degree of condensation of the silsesquioxanes is higher if the reaction is catalyzed by TFA than by DBTL, because TFA may improve the kinetics of both hydrolysis-condensation and esterification reactions. The use of DBTL in under-stoichiometric and stoichiometric hydrolytic conditions raises the yield in ladder-like structures. The degree of condensation generally increases increasing the hydrolysis ratio as well as the yield in cage-like structures. However, when an over-stoichiometric amount of water is provided for the sol-gel reaction, condensation degree and ratio among cages and ladder-like structures appear unaffected by the employed catalyst. PMID:27455755

  10. [Preparation and evaluation of pepsin affinity organic polymer capillary monolithic column].

    PubMed

    Chi, Cuijie; Wang, Wei; Ji, Yibing

    2014-08-01

    The protein modified monolithic column in affinity capillary electrochromatography (CEC) has attracted considerable attention over the past decades because of its great enantioseparation ability. A porous polymethacrylate ester-based capillary monolithic column poly (glycidyl methacrylate-co-ethyleneglycol dimethacrylate) (poly (GMA-co-EDMA)) was prepared by in situ co-polymerization. The process was initiated thermally by azobisisobutyronitrile (AIBN). The polymerization mixture contained GMA as the function monomer and EDMA as the crosslinking agent with 1,4-butanediol and 1-propanol as the binary porogen solvent. Under the optimized reaction conditions, including the proportion of monomer and porogens, reaction temperature etc, the column exhibited a uniform structure, sufficient permeability and excel- lent pressure resistance. The separation of alkyl benzenes on the column was mainly based on typical reversed-phase chromatographic retention mechanism. The reproducibility and stability were good with RSDs less than 9. 0%. A pepsin functionalized organic polymer monolith was prepared by covalently bonded pepsin to poly(GMA-co-EDMA) monolith with glutaraldehyde as a spacer based on the activity of epoxide group. The enantioseparation performance of the pepsin affinity monolith for basic enantiomers has been investigated by CEC. Nefopam, amlodipine, citalopram and chlorpheniramine were resolved, and baseline separations of nefopam, amlodipine, citalopram were achieved. The influences of pH, operating voltage, temperature and sample quantity used on the chiral separation were studied. The chiral recognition mechanism of enantiomers on the monolithic column in CEC is discussed. This work developed a new method for the prepataion and application of protein affinity monolith in CEC.

  11. Development and validation of LC methods for the separation of misoprostol related substances and diastereoisomers.

    PubMed

    Kahsay, Getu; Song, Huiying; Eerdekens, Fran; Tie, Yaxin; Hendriks, Danny; Van Schepdael, Ann; Cabooter, Deirdre; Adams, Erwin

    2015-01-01

    Misoprostol is a synthetic prostaglandin E1 analogue which is mainly used for prevention and treatment of gastric ulcers, but also for abortion due to its labour inducing effect. Misoprostol exists as a mixture of diastereoisomers (1:1) and has several related impurities owing to its instability at higher temperatures and moisture. A simple and robust reversed phase liquid chromatographic (RPLC) method is described for the separation of the related substances and a normal phase (NP) LC method for the separation of misoprostol diastereoisomers. The RPLC method was performed using an Ascentis Express C18 (150 mm × 4.6 mm, 5 μm) column kept at 35 °C. The mobile phase was a gradient mixture of mobile phase A (ACN-H2O-MeOH, 28:69:3 v/v/v) and mobile phase B (ACN-H2O-MeOH, 47:50:3 v/v/v) eluted at a flow rate of 1.5 mL/min. UV detection was performed at 200 nm. The NPLC method was undertaken by using an XBridge bare silica (150 mm × 2.1 mm, 3.5 μm) column at 35 °C. The mobile phase contained 1-propanol-heptane-TFA (4:96:0.1%, v/v/v), pumped at a flow rate of 0.5 mL/min. UV detection was performed at 205 nm. This LC method can properly separate the two diastereoisomers (Rs > 2) within an analysis time of less than 20 min. Both methods were validated according to the ICH guidelines. Furthermore, these new LC methods have been successfully applied for purity control and diastereoisomers ratio determination of misoprostol bulk drug, tablets and dispersion.

  12. Theoretical Modeling of the Chirality Discrimination of Enantiomers by Nanotubular Cyclic Peptides using Gas-Phase Photoelectron Spectroscopy: An ONIOM Spectroscopic Calculations.

    PubMed

    Farrokhpour, H; Karachi, S; Chermahini, A Najafi

    2016-09-01

    In the present work, the chirality recognition of the enantiomers of a chiral molecule (1-phenyl-1-propanol) interacting with a nanotubular cyclic peptide (E-type cyclic decapeptide) was investigated by their ionization in the gas phase, theoretically. The absolute energy difference between the interaction of the S- and R-enantiomer with the cyclic peptide, calculated at the M06-2X/6-311++G(d, p) level of theory, was 4.70 kcal·mol(-1). Two different schemes of "Our own N-layered Integrated molecular Orbital and molecular Mechanics (ONIOM)" method such as (quantum mechanics (QM):molecular mechanics (MM)) and (QM:QM) were employed to study the effect of the interaction on the gas-phase ionization energies of the enantiomers and cyclic peptide, separately. The symmetry-adapted cluster/configuration interaction (SAC-CI) methodology was used for the calculation of the ionization energies. It was found that the difference between the interactions of R- and S-enantiomer with the cyclic peptide caused different changes in the photoelectron spectrum of each enantiomer so that these changes could be used for the chirality discrimination of the enantiomers in the gas phase. Similarly, the photoelectron spectrum of the cyclic peptide interacting with the R and S-enantiomer were calculated, separately, and it was observed that the difference in the interaction with the R- and S-enantiomer created different changes in the spectrum of cyclic peptide. Finally, it was shown that the difference in the interaction of cyclic peptide with the enantiomers of a chiral molecule in the gas phase can be used for the identification of enantiomers in the gas phase by the direct ionization. PMID:27500312

  13. [Influences of uncommon isoenzymes on determination of alkaline phosphatase activity by dry-chemistry analyzers].

    PubMed

    Tozawa, T; Hashimoto, M

    2001-04-01

    Dry-chemistry(DC) analysis may be influenced by some matrix effects for measuring uncommon isoenzyme forms. Placental and intestinal alkaline phosphatase(AP) are overestimated by the VITROS DC, compared with results obtained with the wet-chemistry(WC) method of Bretaudiere, et al. using 2-amino-2-methyl-1-propanol (AMP) buffer, however, no such discrepancy between AP results in any DC method and that with a routine WC method recommended by Japanese Society of Clinical Chemistry in that 2-ethylaminoethanol(EAE) buffer is used, has been demonstrated. The type of buffer used affects differently the rates of AP isoenzymes activities. We therefore examined whether the presence of uncommon AP isoenzyme forms in serum caused aberrant DC results for AP in comparison with a routine WC method using EAE buffer. Here, serum samples with only liver AP and bone AP(n : 32); high-molecular-mass AP(n : 11); placental AP(n : 12); intestinal AP(n : 13) and immunoglobulin (Ig) bound AP(n : 12) were analyzed for total AP activity on three different DC analyzers: VITROS 700XR, FUJIDRYCHEM 5000, SPOTCHEM 4410 and a WC analyzer: HITACHI 7350. Values obtained in all of the DCs for sera containing only liver/bone AP agreed with those with the WC method. For sera containing placental AP, the VITROS values were higher than those with the WC method, while the FUJIDRYCHEM values and the SPOTCHEM values were lower. The VITROS values and the FUJIDRYCHEM values for sera containing intestinal AP were lower than those with the WC method, while the SPOTCHEM values were higher. All of the DCs did not affect high-molecular-mass AP and Ig bound liver/bone AP types of macro AP, but underestimated Ig bound intestinal type. Ig bound intestinal AP may be sieved by DC multilayer elements. PMID:11391954

  14. Aliphatic β-nitroalcohols for therapeutic corneoscleral cross-linking: chemical stability studies using 1H-NMR spectroscopy†

    PubMed Central

    Li, Xia; Li, Yongjun; Kim, MiJung; Trokel, Stephen L.; Turro, Nicholas J.; Paik, David C.

    2013-01-01

    Recent studies suggest that aliphatic β-nitro alcohols (BNAs) may represent a useful class of compounds for use as in vivo therapeutic corneoscleral cross-linking agents with higher order nitroalcohols (HONAs) showing enhanced efficacy over the mono-nitroalcohols. The current study was undertaken in order to evaluate the chemical stability of these compounds during storage conditions. Two mono-nitroalcohols (2-nitroethanol=2ne and 2-nitro-1-propanol=2nprop) and two HONAs, a nitrodiol (2-methyl-2-nitro-1,3-propanediol=MNPD), and a nitrotriol (2-hydroxymethyl-2-nitro-1,3-propanediol=HNPD) were monitored for chemical stability by 1H-NMR for up to 7 months. Each compound was studied at two concentrations (1% and 10%) either in unbuffered H2O or 0.2 M NaH2PO4/Na2HPO4 (pH=5), and at 0°C and room temperature (RT) for a total of 8 conditions for each compound. The 1H-NMR spectra for the starting material were compared to subsequent spectra. Under all 4 of the conditions studied, both the nitrodiol (MNPD) and nitrotriol (HNPD) were stable for the duration of 7 months. 2nprop became unstable under all conditions at 3 months. 2ne was the most unstable of all the compounds tested. HONAs exhibit excellent chemical stability under long-term storage conditions. In contrast, the nitromonols tested are significantly less stable. These findings are relevant to the translation of this technology into clinical use. PMID:23998198

  15. Anti-amyloidogenic effects of glycosphingolipid synthesis inhibitors occur independently of ganglioside alterations.

    PubMed

    Noel, Anastasia; Ingrand, Sabrina; Barrier, Laurence

    2016-09-01

    Evidence has suggested that ganglioside abnormalities may be linked to the proteolytic processing of amyloid precursor protein (APP) in Alzheimer's disease (AD) and that pharmacological inhibition of ganglioside synthesis may reduce amyloid β-peptide (Aβ) production. In this study, we assessed the usefulness of two well-established glycosphingolipid (GSL) synthesis inhibitors, the synthetic ceramide analog D-PDMP (1-phenyl 2-decanoylamino-3-morpholino-1-propanol) and the iminosugar N-butyldeoxynojirimycin (NB-DNJ or miglustat), as anti-amyloidogenic drugs in a human cellular model of AD. We found that both GSL inhibitors were able to markedly inhibit Aβ production, although affecting differently the APP cleavage. Surprisingly, the L-enantiomer of PDMP, which promotes ganglioside accumulation, acted similarly to D-PDMP to inhibit Aβ production. Concurrently, both D- and L-PDMP strongly and equally reduced the levels of long-chain ceramides. Altogether, our data suggested that the anti-amyloidogenic effects of PDMP agents are independent of the altered cellular ganglioside composition, but may result, at least in part, from their ability to reduce ceramide levels. Moreover, our current study established for the first time that NB-DNJ, a drug already used as a therapeutic for Gaucher disease (a lysosomal storage disorder), was also able to reduce Aβ production in our cellular model. Therefore, our study provides novel information regarding the possibilities to target amyloidogenic processing of APP through modulation of sphingolipid metabolism and emphasizes the potential of the iminosugar NB-DNJ as a disease modifying therapy for AD. PMID:27373967

  16. Analytical method for the trace determination of esterified 3- and 2-monochloropropanediol and glycidyl fatty acid esters in various food matrices.

    PubMed

    Samaras, Vasilios G; Giri, Anupam; Zelinkova, Zuzana; Karasek, Lubomir; Buttinger, Gerhard; Wenzl, Thomas

    2016-09-30

    Fatty acid esters of 3-monochloro-1,2-propanediol (3-MCPDEs), of 2-monochloro-1,3-propanediol (2-MCPDEs) and of 2,3-epoxy-1-propanol or glycidol (GEs), which are considered to be deleterious to human health, may occur in a broad variety of food samples. A proper risk assessment of those substances requires the availability of robust occurrence data; in this respect concerns have been raised regarding the reliability of results obtained with the currently available methods to determine those substances in processed food. This article presents an indirect analytical procedure for the simultaneous determination of 3-MCPDEs, 2-MCPDEs and GEs in a wide variety of food products after extraction by pressurised liquid extraction (PLE) and determination by gas chromatography mass-spectrometry (GC-MS). For the differentiation of MCPDEs and GEs, the latter were first converted to monobromopropanediol esters (MBPDEs) in acid aqueous solution of sodium bromide. MCPDEs and MBPDEs were then hydrolysed under acidic conditions followed by derivatisation of the released free (non-esterified) form in ethyl acetate with phenyl boronic acid (PBA). Quantification of the analytes was carried out using the isotopic labelled analogues of both MCPDEs and GEs. Limits of detection (LODs) and limits of quantitation (LOQs) were in the range of 7-17mgkg(-1) and 13-31mgkg(-1) respectively, while the working range of the method was between LOQ and 1850mgkg(-1) expressed on fat basis. The developed method was successfully applied for the analysis of the target compounds in more than 650 different food samples covering the following commodities: bread and rolls, fine bakery wares, smoked fish products, fried and roasted meat, potato based snacks and fried potato products, cereal-based snacks and margarines. PMID:27623063

  17. The same microbiota and a potentially discriminant metabolome in the saliva of omnivore, ovo-lacto-vegetarian and Vegan individuals.

    PubMed

    De Filippis, Francesca; Vannini, Lucia; La Storia, Antonietta; Laghi, Luca; Piombino, Paola; Stellato, Giuseppina; Serrazanetti, Diana I; Gozzi, Giorgia; Turroni, Silvia; Ferrocino, Ilario; Lazzi, Camilla; Di Cagno, Raffaella; Gobbetti, Marco; Ercolini, Danilo

    2014-01-01

    The salivary microbiota has been linked to both oral and non-oral diseases. Scant knowledge is available on the effect of environmental factors such as long-term dietary choices on the salivary microbiota and metabolome. This study analyzed the microbial diversity and metabolomic profiles of the saliva of 161 healthy individuals who followed an omnivore or ovo-lacto-vegetarian or vegan diet. A large core microbiota was identified, including 12 bacterial genera, found in >98% of the individuals. The subjects could be stratified into three "salivary types" that differed on the basis of the relative abundance of the core genera Prevotella, Streptococcus/Gemella and Fusobacterium/Neisseria. Statistical analysis indicated no effect of dietary habit on the salivary microbiota. Phylogenetic beta-diversity analysis consistently showed no differences between omnivore, ovo-lacto-vegetarian and vegan individuals. Metabolomic profiling of saliva using (1)H-NMR and GC-MS/SPME identified diet-related biomarkers that enabled a significant discrimination between the 3 groups of individuals on the basis of their diet. Formate, urea, uridine and 5-methyl-3-hexanone could discriminate samples from omnivores, whereas 1-propanol, hexanoic acid and proline were characteristic of non-omnivore diets. Although the salivary metabolome can be discriminating for diet, the microbiota has a remarkable inter-individual stability and did not vary with dietary habits. Microbial homeostasis might be perturbed with sub-standard oral hygiene or other environmental factors, but there is no current indication that a choice of an omnivore, ovo-lacto-vegetarian or vegan diet can lead to a specific composition of the oral microbiota with consequences on the oral homeostasis. PMID:25372853

  18. Effects of new Torulaspora delbrueckii killer yeasts on the must fermentation kinetics and aroma compounds of white table wine.

    PubMed

    Velázquez, Rocío; Zamora, Emiliano; Álvarez, María L; Hernández, Luis M; Ramírez, Manuel

    2015-01-01

    Torulaspora delbrueckii is becoming widely recommended for improving some specific characteristics of wines. However, its impact on wine quality is still far from satisfactory at the winery level, mostly because it is easily replaced by Saccharomyces cerevisiae-like yeasts during must fermentation. New T. delbrueckii killer strains were here isolated and selected for winemaking. They killed S. cerevisiae yeasts and were able to dominate and complete the fermentation of sterile grape must. Sequential yeast inoculation of non-sterile white must with T. delbrueckii followed by S. cerevisiae did not ensure T. delbrueckii dominance or wine quality improvement. Only a single initial must inoculation at high cell concentrations allowed the T. delbrueckii killer strains to dominate and complete the must fermentation to reach above 11% ethanol, but not the non-killer strains. None of the wines underwent malolactic fermentation as long as the must had low turbidity and pH. Although no statistically significant differences were found in the wine quality score, the S. cerevisiae-dominated wines were preferred over the T. delbrueckii-dominated ones because the former had high-intensity fresh fruit aromas while the latter had lower intensity, but nevertheless nice and unusual dried fruit/pastry aromas. Except for ethyl propanoate and 3-ethoxy-1-propanol, which were more abundant in the T. delbrueckii-dominated wines, most of the compounds with fresh fruit odor descriptors, including those with the greatest odor activity values (isoamyl acetate, ethyl hexanoate, and ethyl octanoate), were more abundant in the S. cerevisiae-dominated wines. The low relative concentrations of these fruity compounds made it possible to detect in the T. delbrueckii-dominated wines the low-relative-concentration compounds with dried fruit and pastry odors. An example was γ-ethoxy-butyrolactone which was significantly more abundant in these wines than in those dominated by S. cerevisiae. PMID:26579114

  19. Novel role of lactosylceramide in vascular endothelial growth factor-mediated angiogenesis in human endothelial cells.

    PubMed

    Rajesh, Mohanraj; Kolmakova, Antonina; Chatterjee, Subroto

    2005-10-14

    Vascular endothelial growth factor (VEGF) has been implicated in angiogenesis associated with coronary heart disease, vascular complications in diabetes, inflammatory vascular diseases, and tumor metastasis. The mechanism of VEGF-driven angiogenesis involving glycosphingolipids such as lactosylceramide (LacCer), however, is not known. To demonstrate the involvement of LacCer in VEGF-induced angiogenesis, we used small interfering RNA (siRNA)-mediated silencing of LacCer synthase expression (GalT-V) in human umbilical vein endothelial cells. This gene silencing markedly inhibited VEGF-induced platelet endothelial cell adhesion molecule-1 (PECAM-1) expression and angiogenesis. Second, we used D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), an inhibitor of LacCer synthase and glucosylceramide synthase, that significantly mitigated VEGF-induced PECAM-1 expression and angiogenesis. Interestingly, these phenotypic changes were reversed by LacCer but not by structurally related compounds such as glucosylceramide, digalactosylceramide, and ceramide. In a human mesothelioma cell line (REN) that lacks the endogenous expression of PECAM-1, VEGF/LacCer failed to stimulate PECAM-1 expression and tube formation/angiogenesis. In REN cells expressing human PECAM-1 gene/protein, however, both VEGF and LacCer-induced PECAM-1 protein expression and tube formation/angiogenesis. In fact, VEGF-induced but not LacCer-induced angiogenesis was mitigated by SU-1498, a VEGF receptor tyrosine kinase inhibitor. Also, VEGF/LacCer-induced PECAM-1 expression and angiogenesis was mitigated by protein kinase C and phospholipase A2 inhibitors. These results indicate that LacCer generated in VEGF-treated endothelial cells may serve as an important signaling molecule for PECAM-1 expression and in angiogenesis. This finding and the reagents developed in our report may be useful as anti-angiogenic drugs for further studies in vitro and in vivo. PMID:16151023

  20. Evaluation of fast volatile analysis for detection of Botrytis cinerea infections in strawberry.

    PubMed

    Vandendriessche, Thomas; Keulemans, Johan; Geeraerd, Annemie; Nicolai, Bart M; Hertog, Maarten L A T M

    2012-12-01

    Grey mold (Botrytis cinerea) is one of the major phytopathogens causing serious losses during strawberry postharvest and storage. B. cinerea-host interaction affect emissions of volatile compounds during infection resulting in a characteristic earthy, mushroom odor. Therefore, the objective of this study was to evaluate two analytical techniques based on fast volatile analysis on their performance for monitoring evolution and early detection of B. cinerea infections in strawberry. In a first experiment headspace multi-capillary column-ion mobility spectrometry (HS MCC-IMS) has been successfully used to evaluate development of strawberry aroma during shelflife. In a second experiment the same technique has been used to detect the degree of B. cinerea infection through changes in the volatile profile. Additionally, these samples were analyzed with headspace solid-phase-microextraction fast GC-MS (HS SPME fast GC-MS). Both HS MCC-IMS and HS SPME fast GC-MS could determine the changes in volatile composition as a function of the degree of B. cinerea infection as determined by an enzyme-linked immunosorbent assay (ELISA) and could be used to follow the evolution of infection. According to the ELISA data, some fruit were infected even without any symptoms and volatiles produced by the fungus may be overshadowed by the fruit volatiles. Therefore, both analytical techniques could not be used for early detection of B. cinerea infections. After identification of the volatile compounds and multivariate data analysis, potential biomarkers specific for B. cinerea were highlighted, being 3-methylbutanal, cis-4-decenal, 2-methyl-1-butanol, 2-methyl-1-propanol, 1-octen-3-one and 1-octen-3-ol. PMID:22986207

  1. Decomposition degree of chlorofluorocarbon (CFC) and CFC replacements during recovery with surface-modified activated carbon

    SciTech Connect

    Tanada, Seiki; Kawasaki, Naohito; Nakamura, Takeo; Abe, Ikuo

    1996-02-10

    The recovery efficiency of 1,1,2-trichloro-1,2,2-trifluoroethane (CFC113) and three CFC replacements (1,1-dichloro-1-fluoroethane, HCFC141b; 1,3-dichloro-1,1,2,2,3-pentafluoro-propane, HCFC225cb; and 2,2,3,3,3-pentafluoro-1-propanol, 5FP) were investigated on the basis of their degree of decomposition and adsorption isotherms. The authors prepared activated carbons with various surface polarities to elucidate the recovery efficiency, the amount adsorbed, and the degree of decomposition. The amount of CFC113 adsorbed onto untreated activated carbon was the largest of all. That of HCFC225cb adsorbed onto activated carbon treated with hydrogen gas was larger than that adsorbed onto untreated activated carbon and activated carbon treated with 6 N nitric acid. The amount of 5FP and HCFC141b adsorbed on the various activated carbons was not substantial. The degree of decomposition of CFC replacements using the untreated activated carbon except for HCFC225cb was the largest of all. In the case without the activated carbon, that of CFC and the CFC replacements increased in the order 5FP, CFC113 or HCFC225cb, and HCFC141b. It is concluded that the recovery of CFC replacements was possible using the surface-modified activated carbons rather than the untreated activated carbon. The degree of decomposition of the CFC replacements during recovery using the activated carbon depends on the relationship between the adsorption site of the surface of the activated carbon and the polarity, hydrophilic site, or hydrophobic site of the CFC replacement molecule.

  2. The Same Microbiota and a Potentially Discriminant Metabolome in the Saliva of Omnivore, Ovo-Lacto-Vegetarian and Vegan Individuals

    PubMed Central

    De Filippis, Francesca; Vannini, Lucia; La Storia, Antonietta; Laghi, Luca; Piombino, Paola; Stellato, Giuseppina; Serrazanetti, Diana I.; Gozzi, Giorgia; Turroni, Silvia; Ferrocino, Ilario; Lazzi, Camilla; Di Cagno, Raffaella; Gobbetti, Marco; Ercolini, Danilo

    2014-01-01

    The salivary microbiota has been linked to both oral and non-oral diseases. Scant knowledge is available on the effect of environmental factors such as long-term dietary choices on the salivary microbiota and metabolome. This study analyzed the microbial diversity and metabolomic profiles of the saliva of 161 healthy individuals who followed an omnivore or ovo-lacto-vegetarian or vegan diet. A large core microbiota was identified, including 12 bacterial genera, found in >98% of the individuals. The subjects could be stratified into three “salivary types” that differed on the basis of the relative abundance of the core genera Prevotella, Streptococcus/Gemella and Fusobacterium/Neisseria. Statistical analysis indicated no effect of dietary habit on the salivary microbiota. Phylogenetic beta-diversity analysis consistently showed no differences between omnivore, ovo-lacto-vegetarian and vegan individuals. Metabolomic profiling of saliva using 1H-NMR and GC-MS/SPME identified diet-related biomarkers that enabled a significant discrimination between the 3 groups of individuals on the basis of their diet. Formate, urea, uridine and 5-methyl-3-hexanone could discriminate samples from omnivores, whereas 1-propanol, hexanoic acid and proline were characteristic of non-omnivore diets. Although the salivary metabolome can be discriminating for diet, the microbiota has a remarkable inter-individual stability and did not vary with dietary habits. Microbial homeostasis might be perturbed with sub-standard oral hygiene or other environmental factors, but there is no current indication that a choice of an omnivore, ovo-lacto-vegetarian or vegan diet can lead to a specific composition of the oral microbiota with consequences on the oral homeostasis. PMID:25372853

  3. Cholesterol-dependent increases in glucosylceramide synthase activity in Niemann-Pick disease type C model cells: Abnormal trafficking of endogenously formed ceramide metabolites by inhibition of the enzyme.

    PubMed

    Hashimoto, Naohiro; Matsumoto, Ikiru; Takahashi, Hiromasa; Ashikawa, Hitomi; Nakamura, Hiroyuki; Murayama, Toshihiko

    2016-11-01

    Sphingolipids such as sphingomyelin and glycosphingolipids (GSLs) derived from glucosylceramide (GlcCer), in addition to cholesterol, accumulate in cells/neurons in Niemann-Pick disease type C (NPC). The activities of acid sphingomyelinase and lysosomal glucocerebrosidase (GCase), which degrade sphingomyelin and GlcCer, respectively, are down-regulated in NPC cells, however, changes in GlcCer synthase activity have not yet been elucidated. We herein demonstrated for the first time that GlcCer synthase activity for the fluorescent ceramide, 4-nitrobenzo-2-oxa-1,3-diazole-labeled C6-ceramide (NBD-ceramide) increased in intact NPC1((-/-)) cells and cell lysates without affecting the protein levels. In NBD-ceramide-labeled NPC1((-/-)) cells, NBD-fluorescence preferentially accumulated in the Golgi complex and vesicular specks in the cytoplasm 40 and 150 min, respectively, after labeling, while a treatment for 48 h with the GlcCer synthase inhibitors, N-butyldeoxynojirimycin (NB-DNJ) and 1-phenyl-2-palmitoylamino-3-morpholino-1-propanol, accelerated the appearance of vesicular specks emitting NBD-fluorescence within 40 min. The treatment of NPC1((-/-)) cells with NB-DNJ for 48 h additionally increased the levels of cholesterol, but not those of sphingomyelin. Increases in the activity of GlcCer synthase and formation of vesicular specks emitting NBD-fluorescence in NPC1((-/-)) cells were dependent on cholesterol. LacCer taken up by endocytosis, which accumulated in the Golgi complex in normal cells, accumulated in vesicular specks after 10 and 40 min in NPC1((-/-)) cells, and this response was not accelerated by the NB-DNJ treatment, but was restored by the depletion of cholesterol. The cellular roles for enhanced GlcCer synthesis and increased levels of cholesterol in the trafficking of NBD-ceramide metabolites in NPC1((-/-)) cells have been discussed.

  4. Alcohol metabolism by oral streptococci and interaction with human papillomavirus leads to malignant transformation of oral keratinocytes.

    PubMed

    Tao, Lin; Pavlova, Sylvia I; Gasparovich, Stephen R; Jin, Ling; Schwartz, Joel

    2015-01-01

    Poor oral hygiene, ethanol consumption, and human papillomavirus (HPV) are associated with oral and esophageal cancers. However, the mechanism is not fully known. This study examines alcohol metabolism in Streptococcus and its interaction with HPV-16 in the malignant transformation of oral keratinocytes. The acetaldehyde-producing strain Streptococcus gordonii V2016 was analyzed for adh genes and activities of alcohol and aldehyde dehydrogenases. Streptococcus attachment to immortalized HPV-16 infected human oral keratinocytes, HOK (HPV/HOK-16B), human oral buccal keratinocytes, and foreskin keratinocytes was studied. Acetaldehyde, malondialdehyde, DNA damage, and abnormal proliferation among keratinocytes were also quantified. We found that S. gordonii V2016 expressed three primary alcohol dehydrogenases, AdhA, AdhB, and AdhE, which all oxidize ethanol to acetaldehyde, but their preferred substrates were 1-propanol, 1-butanol, and ethanol, respectively. S. gordonii V2016 did not show a detectable aldehyde dehydrogenase. AdhE is the major alcohol dehydrogenase in S. gordonii. Acetaldehyde and malondialdehyde production from permissible Streptococcus species significantly increased the bacterial attachment to keratinocytes, which was associated with an enhanced expression of furin to facilitate HPV infection and several malignant phenotypes including acetaldehyde adduct formation, abnormal proliferation, and enhanced migration through integrin-coated basement membrane by HPV-infected oral keratinocytes. Therefore, expression of multiple alcohol dehydrogenases with no functional aldehyde dehydrogenase contributes to excessive production of acetaldehyde from ethanol by oral streptococci. Oral Streptococcus species and HPV may cooperate to transform oral keratinocytes after ethanol exposure. These results suggest a significant clinical interaction, but further validation is warranted.

  5. Conversion of Atmospheric Aerosol by Bacteria and Their Influence on Ice-Nucleation Activity

    NASA Astrophysics Data System (ADS)

    Kos, G.; Shawi, M.; Ariya, P. A.

    2004-05-01

    The presence of microorganisms such as bacteria and fungi in the boundary layer of the atmosphere has been established for some time. These species can also convert organic aerosol species (e.g. dicarboxylic acids), a transformation that was so far assumed to occur only via physico-chemical pathways. As a result, the ice nucleation activity of certain aerosol species can be altered by biochemical transformations including metabolite production and bacterial growth and these new species as well as the microorganisms themselves can act as ice nuclei. In this study we have used dicarboxylic acids (DCA) as model nutrients, which are commonly observed in the aerosol population of the boundary layer. Pseudomonas syringae and Erwinia herbicolae are two types of bacteria that have been found to possess ice nucleation ability, caused by lipoglycoprotein, which consists of a sequence of amino acids that favor the formation of ice. The main objective was to look into the conversion of DCA by bacterial species, their ice nucleating ability and the identification of metabolites from bacterial activity. Furthermore, the influence of different parameters on the ice nucleation of bacteria was investigated. A Freezing Nuclei apparatus was used in order to assess the freezing temperature of a population of small drops to study both homogenous and heterogeneous nucleation of different concentrations of malonic acid containing bacterial species. An acid concentration in the lower Fg/l-range was chosen, matching earlier observations in an urban environment. Other varied parameters include the pH and bacterial membrane shearing. All labware was sterilized prior to use and airtight containers minimized external contamination. Malonic acid concentration was determined by gas chromatography with mass spectrometric detection (GC-MS) after esterification with a mixture of borontrifluoride and 1-propanol, modified from Kawamura, 1991. Malonic acid and its metabolites were identified by

  6. Water-Soluble Pd Nanoparticles Synthesized from ω-Carboxyl-S-Alkanethiosulfate Ligand Precursors as Unimolecular Micelle Catalysts

    PubMed Central

    Gavia, Diego J.; Maung, May S.; Shon, Young-Seok

    2014-01-01

    This report describes a two-phase synthesis of water-soluble carboxylate-functionalized alkanethiolate-capped Pd nanoparticles from ω-carboxyl-S-alkanethiosulfate sodium salts. The two-phase methodology using the thiosulfate ligand passivation protocol allowed a highly specific control over the surface ligand coverage of these nanoparticles, which are lost in a one-phase aqueous system because of the base-catalyzed hydrolysis of thiosulfate to thiolate. Systematic synthetic variations investigated in this study included the concentration of ω-carboxyl-S-alkanethiosulfate ligand precursors and reducing agent, NaBH4, and the overall ligand chain length. The resulting water-soluble Pd nanoparticles were isolated and characterized by transmission electron microscopy (TEM), thermogravimetric analysis (TGA), 1H NMR, UV–vis, and FT-IR spectroscopy. Among different variations, a decrease in the molar equivalent of NaBH4 resulted in a reduction in the surface ligand density while maintaining a similar particle core size. Additionally, reducing the chain length of the thiosulfate ligand precursor also led to the formation of stable nanoparticles with a lower surface coverage. Since the metal core size of these Pd nanoparticle variations remained quite consistent, direct correlation studies between ligand properties and catalytic activities against hydrogenation/isomerization of allyl alcohol could be performed. Briefly, Pd nanoparticles dissolved in water favored the hydrogenation of allyl alcohol to 1-propanol whereas Pd nanoparticles heterogeneously dispersed in chloroform exhibited a rather high selectivity towards the isomerization product (propanal). The results suggested that the surrounding ligand environments, such as the ligand structure, conformation, and surface coverage, were crucial in determining the overall activity and selectivity of the Pd nanoparticle catalysts. PMID:24246150

  7. Contributions of organic peroxides to secondary aerosol formed from reactions of monoterpenes with O3.

    PubMed

    Docherty, Kenneth S; Wu, Wilbur; Lim, Yong Bin; Ziemann, Paul J

    2005-06-01

    The role of organic peroxides in secondary organic aerosol (SOA) formation from reactions of monoterpenes with O3 was investigated in a series of environmental chamber experiments. Reactions were performed with endocyclic (alpha-pinene and delta3-carene) and exocyclic (beta-pinene and sabinene) alkenes in dry and humid air and in the presence of the OH radical scavengers: cyclohexane, 1-propanol, and formaldehyde. A thermal desorption particle beam mass spectrometer was used to probe the identity and volatility of SOA components, and an iodometric-spectrophotometric method was used to quantify organic peroxides. Thermal desorption profiles and mass spectra showed that the most volatile SOA components had vapor pressures similar to pinic acid and that much of the SOA consisted of less volatile species that were probably oligomeric compounds. Peroxide analyses indicated that the SOA was predominantly organic peroxides, providing evidence that the oligomers were mostly peroxyhemiacetals formed by heterogeneous reactions of hydroperoxides and aldehydes. For example, it was estimated that organic peroxides contributed approximately 47 and approximately 85% of the SOA mass formed in the alpha- and beta-pinene reactions, respectively. Reactions performed with different OH radical scavengers indicated that most of the hydroperoxides were formed through the hydroperoxide channel rather than by reactions of stabilized Criegee intermediates. The effect of the OH radical scavenger on the SOA yield was also investigated, and the results were consistent with results of recent experiments and model simulations that support a mechanism based on changes in the [HO2]/[RO2] ratios. These are the first measurements of organic peroxides in monoterpene SOA, and the results have important implications for understanding the mechanisms of SOA formation and the potential effects of atmospheric aerosol particles on the environment and human health.

  8. Improved intervention of atherosclerosis and cardiac hypertrophy through biodegradable polymer-encapsulated delivery of glycosphingolipid inhibitor

    PubMed Central

    Foss, C.A.; Pomper, M.G.; Bhattacharya, R.; Yarema, K.J.; Chatterjee, S.

    2015-01-01

    D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (D-PDMP), a glycosphingolipid synthesis inhibitor, holds promise for the treatment of atherosclerosis and cardiac hypertrophy but rapid in vivo clearance has severely hindered translation to the clinic. To overcome this impediment, we used a materials-based delivery strategy wherein D-PDMP was encapsulated within a biodegradable polymer composed of poly ethylene glycol (PEG) and sebacic acid (SA). PEG-SA was formulated into nanoparticles that were doped with 125I-labeled PEG to allow in vivo bio-distribution and release kinetics of D-PDMP to be determined by using γ-scintigraphy and subsequently, by mass spectrometry. Polymer-encapsulation increased the residence time of D-PDMP in the body of a treated mouse from less than one hour to at least four hours (and up to 48 h or longer). This substantially increased in vivo longevity provided by polymer encapsulation resulted in an order of magnitude gain in efficacy for interfering with atherosclerosis and cardiac hypertrophy in apoE−/− mice fed a high fat and high cholesterol (HFHC) diet. These results establish that D-PDMP encapsulated in a biodegradable polymer provides a superior mode of delivery compared to unconjugated D-PDMP by way of increased gastrointestinal absorption and increased residence time thus providing this otherwise rapidly cleared compound with therapeutic relevance in interfering with atherosclerosis, cardiac hypertrophy, and probably other diseases associated with the deleterious effects of abnormally high glycosphingolipid biosynthesis or deficient catabolism. PMID:26111596

  9. DMSA, DMPS, and DMPA--as arsenic antidotes.

    PubMed

    Aposhian, H V; Carter, D E; Hoover, T D; Hsu, C A; Maiorino, R M; Stine, E

    1984-04-01

    meso-Dimercaptosuccinic acid (DMSA), 2,3-dimercapto-1-propanesulfonic acid, Na salt (DMPS), and N-(2,3- dimercaptopropyl )- phthalamidic acid (DMPA) are water soluble analogs of 2,3-dimercapto-1-propanol (BAL). The relative effectiveness or therapeutic index of these dimercapto compounds in protecting mice from the lethal effects of an LD99 of sodium arsenite is DMSA greater than DMPS greater than DMPA greater than BAL in the magnitude of 42:14:4:1, respectively. DMPS, DMPA, or DMSA will mobilize tissue arsenic. BAL, however, increases the arsenic content of the brain of rabbits injected with sodium arsenite. These results raise the question as to the appropriateness of BAL as the treatment for systemic arsenic poisoning. Either DMSA or DMPS, when given sc or po, will protect rabbits against the lethal systemic effects of subcutaneously administered Lewisite . DMPS and DMSA have promise as prophylactics for the prevention of the vesicant action of Lewisite . The sodium arsenite inhibition of the pyruvate dehydrogenase (PDH) complex can be prevented and reversed in vitro or in vivo by DMPS, DMSA, DMPA, or BAL. Of them all, DMPS is most potent and BAL appears to be the least potent. The usefulness of all these dimercapto compounds would be enhanced by a careful study of their metabolism and biotransformation. These dimercapto compounds are in a great many respects orphan drugs. At this stage of their development, it is very difficult for the clinician to obtain funds to study them clinically even though they appear to be useful for treatment of poisoning by any one of the heavy metals.

  10. 1,2-Ethanediol and 1,3-Propanediol Conversions over (MO3)3 (M = Mo, W) Nanoclusters: A Computational Study.

    PubMed

    Fang, Zongtang; Zetterholm, Patrick; Dixon, David A

    2016-03-24

    The dehydration and dehydrogenation reactions of one and two 1,2-ethanediol and 1,3-propanediol molecules on (MO3)3 (M = Mo, W) nanoclusters have been studied computationally using density functional and coupled cluster (CCSD(T)) theory. The reactions are initiated by the formation of a Lewis acid-base complex with an additional hydrogen bond. Dehydration is the dominant reaction proceeding via a metal bisdiolate. Acetaldehyde, the major product for 1,2-ethanediol, is produced by α-hydrogen transfer from one CH2 group to the other. For 1,3-propanediol, the C-C bond breaking pathways to produce C2H4 and HCH═O simultaneously and proton transfer to generate propylene oxide have comparable barrier energies. The barrier to produce propanal from the propylene oxide complex is less than that for epoxide release from the cluster. On the Mo3O9 cluster, a redox reaction channel for 1,2-ethanediol to break the C-C bond to form two formaldehyde molecules and then to produce C2H4 is slightly more favorable than the formation of acetaldehyde. For W(VI), the energy barrier for the reduction pathway is larger due to the lower reducibility of W3O9. Similar reduction on Mo(VI) for 1,3-propanediol to form propene is not a favorable pathway compared with the other pathways as additional C-H bond breaking is required in addition to breaking a C-C bond. The dehydrogenation and dehydration activation energies for the selected glycols are larger than the reactions of ethanol and 1-propanol on the same clusters. The CCSD(T) method is required because density functional theory with the M06 and B3LYP functionals does not predict quantitative energies on the potential energy surface. The M06 functional performs better than does the B3LYP functional. PMID:26901665

  11. The exometabolome of Clostridium thermocellum reveals overflow metabolism at high cellulose loading

    DOE PAGESBeta

    Holwerda, Evert K.; Thorne, Philip G.; Olson, Daniel G.; Amador-Noguez, Daniel; Engle, Nancy L.; Tschaplinski, Timothy J.; van Dijken, Johannes P.; Lynd, Lee R.

    2014-10-21

    Background: Clostridium thermocellum is a model thermophilic organism for the production of biofuels from lignocellulosic substrates. The majority of publications studying the physiology of this organism use substrate concentrations of ≤10 g/L. However, industrially relevant concentrations of substrate start at 100 g/L carbohydrate, which corresponds to approximately 150 g/L solids. To gain insight into the physiology of fermentation of high substrate concentrations, we studied the growth on, and utilization of high concentrations of crystalline cellulose varying from 50 to 100 g/L by C. thermocellum. Results: Using a defined medium, batch cultures of C. thermocellum achieved 93% conversion of cellulose (Avicel)more » initially present at 100 g/L. The maximum rate of substrate utilization increased with increasing substrate loading. During fermentation of 100 g/L cellulose, growth ceased when about half of the substrate had been solubilized. However, fermentation continued in an uncoupled mode until substrate utilization was almost complete. In addition to commonly reported fermentation products, amino acids - predominantly L-valine and L-alanine - were secreted at concentrations up to 7.5 g/L. Uncoupled metabolism was also accompanied by products not documented previously for C. thermocellum, including isobutanol, meso- and RR/SS-2,3-butanediol and trace amounts of 3-methyl-1-butanol, 2-methyl-1-butanol and 1-propanol. We hypothesize that C. thermocellum uses overflow metabolism to balance its metabolism around the pyruvate node in glycolysis. In conclusion: C. thermocellum is able to utilize industrially relevant concentrations of cellulose, up to 93 g/L. We report here one of the highest degrees of crystalline cellulose utilization observed thus far for a pure culture of C. thermocellum, the highest maximum substrate utilization rate and the highest amount of isobutanol produced by a wild-type organism.« less

  12. The exometabolome of Clostridium thermocellum reveals overflow metabolism at high cellulose loading

    SciTech Connect

    Holwerda, Evert K.; Thorne, Philip G.; Olson, Daniel G.; Amador-Noguez, Daniel; Engle, Nancy L.; Tschaplinski, Timothy J.; van Dijken, Johannes P.; Lynd, Lee R.

    2014-10-21

    Background: Clostridium thermocellum is a model thermophilic organism for the production of biofuels from lignocellulosic substrates. The majority of publications studying the physiology of this organism use substrate concentrations of ≤10 g/L. However, industrially relevant concentrations of substrate start at 100 g/L carbohydrate, which corresponds to approximately 150 g/L solids. To gain insight into the physiology of fermentation of high substrate concentrations, we studied the growth on, and utilization of high concentrations of crystalline cellulose varying from 50 to 100 g/L by C. thermocellum. Results: Using a defined medium, batch cultures of C. thermocellum achieved 93% conversion of cellulose (Avicel) initially present at 100 g/L. The maximum rate of substrate utilization increased with increasing substrate loading. During fermentation of 100 g/L cellulose, growth ceased when about half of the substrate had been solubilized. However, fermentation continued in an uncoupled mode until substrate utilization was almost complete. In addition to commonly reported fermentation products, amino acids - predominantly L-valine and L-alanine - were secreted at concentrations up to 7.5 g/L. Uncoupled metabolism was also accompanied by products not documented previously for C. thermocellum, including isobutanol, meso- and RR/SS-2,3-butanediol and trace amounts of 3-methyl-1-butanol, 2-methyl-1-butanol and 1-propanol. We hypothesize that C. thermocellum uses overflow metabolism to balance its metabolism around the pyruvate node in glycolysis. In conclusion: C. thermocellum is able to utilize industrially relevant concentrations of cellulose, up to 93 g/L. We report here one of the highest degrees of crystalline cellulose utilization observed thus far for a pure culture of C. thermocellum, the highest maximum substrate utilization rate and the highest amount of isobutanol produced by a wild-type organism.

  13. Random mutagenesis and selection of organic solvent-stable haloperoxidase from Streptomyces aureofaciens.

    PubMed

    Yamada, Ryosuke; Higo, Tatsutoshi; Yoshikawa, Chisa; China, Hideyasu; Yasuda, Masahiro; Ogino, Hiroyasu

    2015-01-01

    Haloperoxidases are useful oxygenases involved in halogenation of a range of water-insoluble organic compounds and can be used without additional high-cost cofactors. In particular, organic solvent-stable haloperoxidases are desirable for enzymatic halogenations in the presence of organic solvents. In this study, we adopted a directed evolution approach by error-prone polymerase chain reaction to improve the organic solvent-stability of the homodimeric BPO-A1 haloperoxidase from Streptomyces aureofaciens. Among 1,000 mutant BPO-A1 haloperoxidases, an organic solvent-stable mutant OST48 with P123L and P241A mutations and a high active mutant OST959 with H53Y and G162R mutations were selected. The residual activity of mutant OST48 after incubation in 40% (v/v) 1-propanol for 1 h was 1.8-fold higher than that of wild-type BPO-A1. In addition, the OST48 mutant showed higher stability in methanol, ethanol, dimethyl sulfoxide, and N,N-dimethylformamide than wild-type BPO-A1 haloperoxidase. Moreover, after incubation at 80°C for 1 h, the residual activity of mutant OST959 was 4.6-fold higher than that of wild-type BPO-A1. Based on the evaluation of single amino acid-substituted mutant models, stabilization of the hydrophobic core derived from P123L mutation and increased numbers of hydrogen bonds derived from G162R mutation led to higher organic solvent-stability and thermostability, respectively.

  14. Inactivation of Staphylococcus aureus in Oat and Soya Drinks by Enterocin AS-48 in Combination with Other Antimicrobials.

    PubMed

    Burgos, María José Grande; Aguayo, M Carmen López; Pulido, Rubén Pérez; Gálvez, Antonio; López, Rosario Lucas

    2015-09-01

    The presence of toxicogenic Staphylococcus aureus in foods and the dissemination of methicillin-resistant S. aureus (MRSA) in the food chain are matters of concern. In the present study, the circular bacteriocin enterocin AS-48, applied singly or in combination with phenolic compounds (carvacrol, eugenol, geraniol, and citral) or with 2-nitro-1-propanol (2NPOH), was investigated in the control of a cocktail made from 1 methicillin-sensitive and 1 MRSA strains inoculated on commercial oat and soya drinks. Enterocin AS-48 exhibited low bactericidal activity against staphylococci in the drinks investigated when applied singly. The combinations of sub-inhibitory concentrations of enterocin AS-48 (25 μg/mL) and phenolic compounds or 2NPOH caused complete inactivation of staphylococci in the drinks within 24 h of incubation at 22 °C. When tested in oat and soya drinks stored for 7 d at 10 °C, enterocin AS-48 (25 μg/mL) in combination with 2NPOH (5.5 mM) reduced viable counts rapidly in the case of oat drink (4.2 log cycles after 12 h) or slowly in soya drink (3.8 log cycles after 3 d). The same combined treatment applied on drinks stored at 22 °C achieved a fast inactivation of staphylococci within 12 to 24 h in both drinks, and no viable staphylococci were detected for up to 7 d of storage. Results from the study highlight the potential of enterocin AS-48 in combination with 2NPOH for inactivation of staphylococci.

  15. On the effective measurement frequency of time domain reflectometry in dispersive and nonconductive dielectric materials

    NASA Astrophysics Data System (ADS)

    Robinson, D. A.; Schaap, M. G.; Or, D.; Jones, S. B.

    2005-02-01

    Time domain reflectometry (TDR) is one of the most commonly used techniques for water content determination in the subsurface. The measurement results in a single bulk permittivity value that corresponds to a particular, but unknown, ``effective'' frequency (feff). Estimating feff using TDR is important, as it allows comparisons with other techniques, such as impedance or capacitance probes, or microwave remote sensing devices. Soils, especially those with high clay and organic matter content, show appreciable dielectric dispersion, i.e., the real permittivity changes as a function of frequency. Consequently, comparison of results obtained with different sensor types must account for measurement frequency in assessing sensor accuracy and performance. In this article we use a transmission line model to examine the impact of dielectric dispersion on the TDR signal, considering lossless materials (negligible electrical conductivity). Permittivity is inferred from the standard tangent line fitting procedure (KaTAN) and by a method of using the apex of the derivative of the TDR waveform (KaDER). The permittivity determined using the tangent line method is considered to correspond to a velocity associated with a maximum passable frequency; whereas we consider the permittivity determined from the derivative method to correspond with the frequency associated with the signal group velocity. The effective frequency was determined from the 10-90% risetime of the reflected signal. On the basis of this definition, feff was found to correspond with the permittivity determined from KaDER and not from KaTAN in dispersive dielectrics. The modeling is corroborated by measurements in bentonite, ethanol and 1-propanol/water mixtures, which demonstrate the same result. Interestingly, for most nonconductive TDR measurements, frequencies are expected to lie in a range from 0.7 to 1 GHz, while in dispersive media, feff is expected to fall below 0.6 GHz.

  16. On the effective measurement frequency of time domain reflectometry in dispersive and nonconductive dielectric materials

    NASA Astrophysics Data System (ADS)

    Robinson, D. A.; Schaap, M. G.; Or, D.; Jones, S. B.

    2005-02-01

    Time domain reflectometry (TDR) is one of the most commonly used techniques for water content determination in the subsurface. The measurement results in a single bulk permittivity value that corresponds to a particular, but unknown, "effective" frequency (feff). Estimating feff using TDR is important, as it allows comparisons with other techniques, such as impedance or capacitance probes, or microwave remote sensing devices. Soils, especially those with high clay and organic matter content, show appreciable dielectric dispersion, i.e., the real permittivity changes as a function of frequency. Consequently, comparison of results obtained with different sensor types must account for measurement frequency in assessing sensor accuracy and performance. In this article we use a transmission line model to examine the impact of dielectric dispersion on the TDR signal, considering lossless materials (negligible electrical conductivity). Permittivity is inferred from the standard tangent line fitting procedure (KaTAN) and by a method of using the apex of the derivative of the TDR waveform (KaDER). The permittivity determined using the tangent line method is considered to correspond to a velocity associated with a maximum passable frequency; whereas we consider the permittivity determined from the derivative method to correspond with the frequency associated with the signal group velocity. The effective frequency was determined from the 10-90% risetime of the reflected signal. On the basis of this definition, feff was found to correspond with the permittivity determined from KaDER and not from KaTAN in dispersive dielectrics. The modeling is corroborated by measurements in bentonite, ethanol and 1-propanol/water mixtures, which demonstrate the same result. Interestingly, for most nonconductive TDR measurements, frequencies are expected to lie in a range from 0.7 to 1 GHz, while in dispersive media, feff is expected to fall below 0.6 GHz.

  17. Cyanobacterial blue color formation during lysis under natural conditions.

    PubMed

    Arii, Suzue; Tsuji, Kiyomi; Tomita, Koji; Hasegawa, Masateru; Bober, Beata; Harada, Ken-ichi

    2015-04-01

    Cyanobacteria produce numerous volatile organic compounds (VOCs), such as β-cyclocitral, geosmin, and 2-methylisoborneol, which show lytic activity against cyanobacteria. Among these compounds, only β-cyclocitral causes a characteristic color change from green to blue (blue color formation) in the culture broth during the lysis process. In August 2008 and September 2010, the lysis of cyanobacteria involving blue color formation was observed at Lake Tsukui in northern Kanagawa Prefecture, Japan. We collected lake water containing the cyanobacteria and investigated the VOCs, such as β-cyclocitral, β-ionone, 1-propanol, 3-methyl-1-butanol, and 2-phenylethanol, as well as the number of cyanobacterial cells and their damage and pH changes. As a result, the following results were confirmed: the detection of several VOCs, including β-cyclocitral and its oxidation product, 2,2,6-trimethylcyclohexene-1-carboxylic acid; the identification of phycocyanin based on its visible spectrum; the lower pH (6.7 and 5.4) of the lysed samples; and characteristic morphological change in the damaged cyanobacterial cells. We also encountered the same phenomenon on 6 September 2013 in Lake Sagami in northern Kanagawa Prefecture and obtained almost the same results, such as blue color formation, decreasing pH, damaged cells, and detection of VOCs, including the oxidation products of β-cyclocitral. β-Cyclocitral derived from Microcystis has lytic activity against Microcystis itself but has stronger inhibitory activity against other cyanobacteria and algae, suggesting that the VOCs play an important role in the ecology of aquatic environments.

  18. Supporting technology for the development of Controlled Ecological Life Support Systems (CELSS)

    NASA Technical Reports Server (NTRS)

    Li, Ku-Yen; Yaws, Carl L.; Simon, William E.; Mei, Harry T.

    1995-01-01

    To support the development of Controlled Ecological Life Support Systems (CELSS) in the space program, a metabolic simulator has been selected for use in a closed chamber to test functions of the CELSS. This metabolic simulator is a catalytic reactor which oxidizes the methyl acetate to produce carbon dioxide and water vapor. In this project, kinetic studies of catalytic oxidation of methyl acetate were conducted using monolithic and pellet catalysts with 0.5% (by weight) platinum (Pt) on aluminum oxide (Al2O3). The reaction was studied at a pressure of one atmosphere and at temperatures varying from 160 C to 420 C. By-products were identified at the exit of the preheater and reactor. For the kinetic study with the monolithic catalyst, a linear regression method was used to correlate the kinetic data with zero-order, first-order and Langmuir-Hinshelwood models. Results indicate that the first-order model represents the data adequately at low concentrations of methyl acetate. For higher concentrations of methyl acetate, the Langmuir-Hinshelwood model best represents the kinetic data. Both rate constant and adsorption equilibrium constants were estimated from the regression. A Taguchi orthogonal array (L(sub 9)) was used to investigate the effects of temperature, flow rate, and concentration on the catalytic oxidation of methyl acetate. For the monolithic catalyst, temperature exerts the most significant effect, followed by concentration of methyl acetate. For the pellet catalyst, reaction temperature is the most significant factor, followed by gas flow rate and methyl acetate concentration. Concentrations of either carbon dioxide or oxygen were seen to have insignificant effect on the methyl acetate conversion process. Experimental results indicate that the preheater with glass beads can accomplish thermal cracking and catalytic reaction of methyl acetate to produce acetic acid, methanol, methyl formate, and 1-propanol. The concentration of all by-products was

  19. Biochemical Characterization of Rotavirus Receptors in MA104 Cells

    PubMed Central

    Guerrero, Carlos A.; Zárate, Selene; Corkidi, Gabriel; López, Susana; Arias, Carlos F.

    2000-01-01

    We have tested the effect of metabolic inhibitors, membrane cholesterol depletion, and detergent extraction of cell surface molecules on the susceptibility of MA104 cells to infection by rotaviruses. Treatment of cells with tunicamycin, an inhibitor of protein N glycosylation, blocked the infectivity of the SA-dependent rotavirus RRV and its SA-independent variant nar3 by about 50%, while the inhibition of O glycosylation had no effect. The inhibitor of glycolipid biosynthesis d,l-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) blocked the infectivity of RRV, nar3, and the human rotavirus strain Wa by about 70%. Sequestration of cholesterol from the cell membrane with β-cyclodextrin reduced the infectivity of the three viruses by more than 90%. The involvement of N-glycoproteins, glycolipids, and cholesterol in rotavirus infection suggests that the virus receptor(s) might be forming part of lipid microdomains in the cell membrane. MA104 cells incubated with the nonionic detergent octyl-β-glucoside (OG) showed a ca. 60% reduction in their ability to bind rotaviruses, the same degree to which they became refractory to infection, suggesting that OG extracts the potential virus receptor(s) from the cell surface. Accordingly, when preincubated with the viruses, the OG extract inhibited the virus infectivity by more than 95%. This inhibition was abolished when the extract was treated with either proteases or heat but not when it was treated with neuraminidase, indicating the protein nature of the inhibitor. Two protein fractions of around 57 and 75 kDa were isolated from the extract, and these fractions were shown to have rotavirus-blocking activity. Also, antibodies to these fractions efficiently inhibited the infectivity of the viruses in untreated as well as in neuraminidase-treated cells. Five individual protein bands of 30, 45, 57, 75, and 110 kDa, which exhibited virus-blocking activity, were finally isolated from the OG extract. These proteins are

  20. Insights on Alterations to the Rumen Ecosystem by Nitrate and Nitrocompounds.

    PubMed

    Latham, Elizabeth A; Anderson, Robin C; Pinchak, William E; Nisbet, David J

    2016-01-01

    Nitrate and certain short chain nitrocompounds and nitro-oxy compounds are being investigated as dietary supplements to reduce economic and environmental costs associated with ruminal methane emissions. Thermodynamically, nitrate is a preferred electron acceptor in the rumen that consumes electrons at the expense of methanogenesis during dissimilatory reduction to an intermediate, nitrite, which is primarily reduced to ammonia although small quantities of nitrous oxide may also be produced. Short chain nitrocompounds act as direct inhibitors of methanogenic bacteria although certain of these compounds may also consume electrons at the expense of methanogenesis and are effective inhibitors of important foodborne pathogens. Microbial and nutritional consequences of incorporating nitrate into ruminant diets typically results in increased acetate production. Unlike most other methane-inhibiting supplements, nitrate decreases or has no effect on propionate production. The type of nitrate salt added influences rates of nitrate reduction, rates of nitrite accumulation and efficacy of methane reduction, with sodium and potassium salts being more potent than calcium nitrate salts. Digestive consequences of adding nitrocompounds to ruminant diets are more variable and may in some cases increase propionate production. Concerns about the toxicity of nitrate's intermediate product, nitrite, to ruminants necessitate management, as animal poisoning may occur via methemoglobinemia. Certain of the naturally occurring nitrocompounds, such as 3-nitro-1-propionate or 3-nitro-1-propanol also cause poisoning but via inhibition of succinate dehydrogenase. Typical risk management procedures to avoid nitrite toxicity involve gradually adapting the animals to higher concentrations of nitrate and nitrite, which could possibly be used with the nitrocompounds as well. A number of organisms responsible for nitrate metabolism in the rumen have been characterized. To date a single rumen bacterium

  1. Slow oxidation of acetoxime and methylethyl ketoxime to the corresponding nitronates and hydroxy nitronates by liver microsomes from rats, mice, and humans.

    PubMed

    Völkel, W; Wolf, N; Derelanko, M; Dekant, W

    1999-02-01

    Acetoxime and methylethyl ketoxime (MEKO) are tumorigenic in rodents, inducing liver tumors in male animals. The mechanisms of tumorigenicity for these compounds are not well defined. Oxidation of the oximes to nitronates of secondary-nitroalkanes, which are mutagenic and tumorigenic in rodents, has been postulated to play a role in the bioactivation of ketoximes. In these experiments, we have compared the oxidation of acetoxime and methylethyl ketoxime to corresponding nitronates in liver microsomes from different species. The oximes were incubated with liver microsomes from mice, rats, and several human liver samples. After tautomeric equilibration and extraction with n-hexane, 2-nitropropane and 2-nitrobutane were quantitated by GC/MS-NCI (limit of detection of 250 fmol/injection volume). In liver microsomes, nitronate formation from MEKO and acetoxime was dependent on time, enzymatically active proteins, and the presence of NADPH. Nitronate formation was increased in liver microsomes of rats pretreated with inducers of cytochrome P450 and reduced in the presence of inhibitors (n-octylamine and diethyldithiocarbamate). Rates of oxidation of MEKO (Vmax) were 1.1 nmol/min/mg (mice), 0.5 nmol/min/mg (humans), and 0.1 nmol/min/mg (rats). In addition to nitronates, several minor metabolites were also enzymatically formed (two diastereoisomers of 3-nitro-2-butanol, 2-hydroxy-3-butanone oxime and 2-nitro-1-butanol). Acetoxime was also metabolized to the corresponding nitronate at rates approximately 50% of those observed with MEKO oxidation in the three species examined. 2-Nitro-1-propanol was identified as a minor product formed from acetoxime. No sex differences in the capacity to oxidize acetoxime and MEKO were observed in the species examined. The observed results show that formation of sec-nitronates from ketoximes occurs slowly, but is not the only pathway involved in the oxidative biotransformation of these compounds. Due to the lack of sex-specific oxidative

  2. Regulation of SREBPs by Sphingomyelin in Adipocytes via a Caveolin and Ras-ERK-MAPK-CREB Signaling Pathway.

    PubMed

    Makdissy, Nehman; Haddad, Katia; Mouawad, Charbel; Popa, Iuliana; Younsi, Mohamed; Valet, Philippe; Brunaud, Laurent; Ziegler, Olivier; Quilliot, Didier

    2015-01-01

    Sterol response element binding protein (SREBP) is a key transcription factor in insulin and glucose metabolism. We previously demonstrated that elevated levels of membrane sphingomyelin (SM) were related to peroxisome proliferator-activated receptor-γ (PPARγ), which is a known target gene of SREBP-1 in adipocytes. However, the role of SM in SREBP expression in adipocytes remains unknown. In human abdominal adipose tissue from obese women with various concentrations of fasting plasma insulin, SREBP-1 proteins decreased in parallel with increases in membrane SM levels. An inverse correlation was found between the membrane SM content and the levels of SREBP-1c/ERK/Ras/PPARγ/CREB proteins. For the first time, we demonstrate the effects of SM and its signaling pathway in 3T3-F442A adipocytes. These cells were enriched or unenriched with SM in a range of concentrations similar to those observed in obese subjects by adding exogenous natural SMs (having different acyl chain lengths) or by inhibiting neutral sphingomyelinase. SM accumulated in caveolae of the plasma membrane within 24 h and then in the intracellular space. SM enrichment decreased SREBP-1 through the inhibition of extracellular signal-regulated protein kinase (ERK) but not JNK or p38 mitogen-activated protein kinase (MAPK). Ras/Raf-1/MEK1/2 and KSR proteins, which are upstream mediators of ERK, were down-regulated, whereas SREBP-2/caveolin and cholesterol were up-regulated. In SM-unmodulated adipocytes treated with DL-1-Phenyl-2-Palmitoylamino-3-morpholino-1-propanol (PPMP), where the ceramide level increased, the expression levels of SREBPs and ERK were modulated in an opposite direction relative to the SM-enriched cells. SM inhibited the insulin-induced expression of SREBP-1. Rosiglitazone, which is an anti-diabetic agent and potent activator of PPARγ, reversed the effects of SM on SREBP-1, PPARγ and CREB. Taken together, these findings provide novel insights indicating that excess membrane SM might

  3. Photochemical ozone creation potentials for oxygenated volatile organic compounds: sensitivity to variations in kinetic and mechanistic parameters

    NASA Astrophysics Data System (ADS)

    Jenkin, Michael E.; Hayman, Garry D.

    The sensitivity of Photochemical Ozone Creation Potentials (POCP) to a series of systematic variations in the rates and products of reactions of radical intermediates and oxygenated products is investigated for the C 4 alcohols, 1-butanol ( n-butanol) and 2-methyl-1-propanol ( i-butanol), using the recently developed Master Chemical Mechanism (MCM) as the base case. The POCP values are determined from the calculated formation of ozone in the boundary layer over a period of approximately five days along an idealised straight line trajectory, using a photochemical trajectory model and methodology described in detail previously. The results allow the relative impacts on calculated ozone formation of various classes of chemical reaction within the degradation chemistry to be assessed. The calculated POCP is found to be very insensitive to many of the changes investigated. However, it is found to be sensitive to variations in the rate coefficient for the initiating reaction with OH ( kOH), although the sensitivity decreases with increasing kOH. The POCP appears to vary approximately linearly with kOH at low values (i.e. kOH less than ca. 4×10 -13 cm 3 molecule -1 s -1), whereas at high reactivities (i.e. kOH greater than ca. 4×10 -11 cm 3 molecule -1 s -1), the calculated POCP value is comparatively insensitive to the precise value of kOH. The POCP is also very sensitive to mechanistic changes which influence the yields of unreactive oxygenated products (i.e. those with OH reactivities below ca. 10 -12 cm 3 molecule -1 s -1), for example acetone. The propensity of the organic compound to produce organic nitrates (which act as comparatively unreactive reservoirs for free radicals and NO x) also appears to have a notable influence on the calculated POCP. Recently reported information relevant to the degradation of oxygenated VOCs is then used to update the chemical schemes for the 17 alcohols and glycols, 10 ethers and glycol ethers, and 8 esters included in the MCM

  4. Cross-linked gold nanoparticles on polyethylene: resistive responses to tensile strain and vapors.

    PubMed

    Olichwer, Natalia; Leib, Elisabeth W; Halfar, Annelie H; Petrov, Alexey; Vossmeyer, Tobias

    2012-11-01

    In this study, coatings of cross-linked gold nanoparticles (AuNPs) on flexible polyethylene (PE) substrates were prepared via layer-by-layer deposition and their application as strain gauges and chemiresistors was investigated. Special emphasis was placed on characterizing the influence of strain on the chemiresistive responses. The coatings were deposited using amine stabilized AuNPs (4 and 9 nm diameter) and 1,9-nonanedithiol (NDT) or pentaerythritol tetrakis(3-mercaptopropionate) (PTM) as cross-linkers. To prepare films with homogeneous optical appearance, it was necessary to treat the substrates with oxygen plasma directly before film assembly. SEM images revealed film thicknesses between ∼60 and ∼90 nm and a porous nanoscale morphology. All films showed ohmic I-V characteristics with conductivities ranging from 1 × 10⁻⁴ to 1 × 10⁻² Ω⁻¹ cm⁻¹, depending on the structure of the linker and the nanoparticle size. When up to 3% strain was induced their resistance increased linearly and reversibly (gauge factors: ∼20). A comparative SEM investigation indicated that the stress induced formation and extension of nanocracks are important components of the signal transduction mechanism. Further, all films responded with a reversible increase in resistance when dosed with toluene, 4-methyl-2-pentanone, 1-propanol or water vapor (concentrations: 50-10 000 ppm). Films deposited onto high density PE substrates showed much faster response-recovery dynamics than films deposited onto low density PE. The chemical selectivity of the coatings was controlled by the chemical nature of the cross-linkers, with the highest sensitivities (∼1 × 10⁻⁵ ppm⁻¹) measured with analytes of matching solubility. The response isotherms of all film/vapor pairs could be fitted using a Langmuir-Henry model suggesting selective and bulk sorption. Under tensile stress (1% strain) all chemiresistors showed a reversible increase in their response amplitudes (∼30

  5. Peak shapes of acids and bases under overloaded conditions in reversed-phase liquid chromatography, with weakly buffered mobile phases of various pH: a thermodynamic interpretation.

    PubMed

    Gritti, Fabrice; Guiochon, Georges

    2009-01-01

    We measured overloaded band profiles for a series of nine compounds (phenol, caffeine, 3-phenyl 1-propanol, 2-phenylbutyric acid, amphetamine, aniline, benzylamine, p-toluidine, and procainamidium chloride) on columns packed with four different C(18)-bonded packing materials: XTerra-C(18), Gemini-C(18), Luna-C(18)(2), and Halo-C(18), using buffered methanol-water mobile phases. The pHWS of the mobile phase was increased from 2.6 to 11.3. The buffer concentration (either phosphate, acetate, or carbonate buffers) was set constant at values below the maximum concentration of the sample in the band. The influence of the surface chemistry of the packing material on the retention and the shape of the peaks was investigated. Adsorbents having a hybrid inorganic/organic structure tend to give peaks exhibiting moderate or little tailing. The retention and the shape of the band profiles can easily be interpreted at pHsWS that are well above or well below the pKWS(a) of the compound studied. In contrast, the peak shapes in the intermediary pH range (i.e., close to the compound pKWS(a)) have rarely been studied. These shapes reveal the complexity of the competitive adsorption behavior of couples of acido-basic conjugated compounds at pHsWS that are close to their pKWS(a). They also reveal the role of the buffer capacity on the resulting peak shape. With increasing pHWS, the overloaded profiles are first langmuirian (isotherm type I) at low pHsWS, they become S-shaped (isotherm type II), then anti-langmuirian (isotherm type III), S-shaped again at intermediate pHsWS, and finally return to a langmuirian shape at high pHsWS. A new general adsorption isotherm model that takes into account the dissociation equilibrium of conjugated acidic and basic species in the bulk mobile phase accounts for these transient band shapes. An excellent agreement was achieved between experimental profiles and those calculated with a two-sites adsorption isotherm model at all pHsWS. The neutral

  6. Identification of potent odourants in wine and brewed coffee using gas chromatography-olfactometry and comprehensive two-dimensional gas chromatography.

    PubMed

    Chin, Sung-Tong; Eyres, Graham T; Marriott, Philip J

    2011-10-21

    Volatile constituents in wine and brewed coffee were analyzed using a combined system incorporating both GC-olfactometry (GC-O) and comprehensive two-dimensional GC-flame ionization detection (GC×GC-FID). A column set consisting of a 15m first dimension ((1)D; DB-FFAP (free fatty acid phase)), and a 1.0m (2)D column (DB-5 phase) was applied to achieve the GC×GC separation of the volatile extracts isolated by using solid phase extraction (SPE). While 1D GC resulted in many overlapping peaks, GC×GC allowed resolution of co-eluting compounds which coincided with the odour region located using GC-O. Character-impact odourants were tentatively identified through data correlation of GC×GC contour plots across results obtained using either time-of-flight mass spectrometry (TOFMS), or with flame photometric detection (FPD) for sulfur speciation. The odourants 2-methyl-2-butenal, 2-(methoxymethyl)-furan, dimethyl trisulfide, 2-ethyl-5-methyl-pyrazine, 2-octenal, 2-furancarboxaldehyde, 3-mercapto-3-methyl-1-butanol, 2-methoxy-3-(2-methylpropyl)-pyrazine, 2-furanmethanol and isovaleric acid were suspected to be particularly responsible for coffee aroma using this approach. The presented methodology was applied to identify the potent odourants in two different Australian wine varietals. 1-Octen-3-ol, butanoic acid and 2-methylbutanoic acid were detected in both Merlot and a Sauvignon Blanc+Semillon (SV) blend with high aroma potency. Several co-eluting peaks of ethyl 4-oxo-pentanoate, 3,7-dimethyl-1,5,7-octatrien-3-ol, (Z)-2-octen-1-ol, 5-hydroxy-2-methyl-1,3-dioxane were likely contributors to the Merlot wine aroma; while (Z)-3-hexen-1-ol, β-phenylethyl acetate, hexanoic acid and co-eluting peaks of 3-ethoxy-1-propanol and hexyl formate may contribute to SV wine aroma character. The volatile sulfur compound 2-mercapto-ethyl acetate was believed to contribute a fruity, brothy, meaty, sulfur odour to Australian Merlot and SV wines. PMID:21741655

  7. Lactivibrio alcoholicus gen. nov., sp. nov., an anaerobic, mesophilic, lactate-, alcohol-, carbohydrate- and amino-acid-degrading bacterium in the phylum Synergistetes.

    PubMed

    Qiu, Yan-Ling; Hanada, Satoshi; Kamagata, Yoichi; Guo, Rong-Bo; Sekiguchi, Yuji

    2014-06-01

    A mesophilic, obligately anaerobic, lactate-, alcohol-, carbohydrate- and amino-acid- degrading bacterium, designated strain 7WAY-8-7(T), was isolated from an upflow anaerobic sludge blanket reactor treating high-strength organic wastewater from isomerized sugar production processes. Cells of strain 7WAY-8-7(T) were motile, curved rods (0.7-1.0×5.0-8.0 µm). Spore formation was not observed. The strain grew optimally at 37 °C (range for growth was 25-40 °C) and pH 7.0 (pH 6.0-7.5), and could grow fermentatively on yeast extract, glucose, ribose, xylose, malate, tryptone, pyruvate, fumarate, Casamino acids, serine and cysteine. The main end-products of glucose fermentation were acetate and hydrogen. In co-culture with the hydrogenotrophic methanogen Methanospirillum hungatei DSM 864(T), strain 7WAY-8-7(T) could utilize lactate, glycerol, ethanol, 1-propanol, 1-butanol, L-glutamate, alanine, leucine, isoleucine, valine, histidine, asparagine, glutamine, arginine, lysine, threonine, 2-oxoglutarate, aspartate and methionine. A Stickland reaction was not observed with some pairs of amino acids. Yeast extract was required for growth. Nitrate, sulfate, thiosulfate, elemental sulfur, sulfite and Fe (III) were not used as terminal electron acceptors. The G+C content of the genomic DNA was 61.4 mol%. 16S rRNA gene sequence analysis revealed that the isolate belongs to the uncultured environmental clone clade (called 'PD-UASB-13' in the Greengenes database) in the bacterial phylum Synergistetes, showing less than 90% sequence similarity with closely related described species such as Aminivibrio pyruvatiphilus and Aminobacterium colombiense (89.7% and 88.7%, respectively). The major cellular fatty acids were iso-C(13 : 0), iso-C(15 : 0), anteiso-C(15 : 0), C(18 : 1), C(19 : 1), C(20 : 1) and C(21 : 1). A novel genus and species, Lactivibrio alcoholicus gen. nov., sp. nov. is proposed to accommodate strain 7WAY-8-7(T) ( = JCM 17151(T

  8. Molecular analysis of volatile metabolites released specifically by staphylococcus aureus and pseudomonas aeruginosa

    PubMed Central

    2012-01-01

    Background The routinely used microbiological diagnosis of ventilator associated pneumonia (VAP) is time consuming and often requires invasive methods for collection of human specimens (e.g. bronchoscopy). Therefore, it is of utmost interest to develop a non-invasive method for the early detection of bacterial infection in ventilated patients, preferably allowing the identification of the specific pathogens. The present work is an attempt to identify pathogen-derived volatile biomarkers in breath that can be used for early and non- invasive diagnosis of ventilator associated pneumonia (VAP). For this purpose, in vitro experiments with bacteria most frequently found in VAP patients, i.e. Staphylococcus aureus and Pseudomonas aeruginosa, were performed to investigate the release or consumption of volatile organic compounds (VOCs). Results Headspace samples were collected and preconcentrated on multibed sorption tubes at different time points and subsequently analyzed with gas chromatography mass spectrometry (GC-MS). As many as 32 and 37 volatile metabolites were released by S. aureus and P. aeruginosa, respectively. Distinct differences in the bacteria-specific VOC profiles were found, especially with regard to aldehydes (e.g. acetaldehyde, 3-methylbutanal), which were taken up only by P. aeruginosa but released by S. aureus. Differences in concentration profiles were also found for acids (e.g. isovaleric acid), ketones (e.g. acetoin, 2-nonanone), hydrocarbons (e.g. 2-butene, 1,10-undecadiene), alcohols (e.g. 2-methyl-1-propanol, 2-butanol), esters (e.g. ethyl formate, methyl 2-methylbutyrate), volatile sulfur compounds (VSCs, e.g. dimethylsulfide) and volatile nitrogen compounds (VNCs, e.g. 3-methylpyrrole). Importantly, a significant VOC release was found already 1.5 hours after culture start, corresponding to cell numbers of ~8*106 [CFUs/ml]. Conclusions The results obtained provide strong evidence that the detection and perhaps even identification of bacteria

  9. Alkaline phosphatase activity: new assay for the Reflotron system. Results of the evaluation in eight clinical laboratories.

    PubMed

    Schumann, G; Dominick, H C; Hellmann, D; Klauke, R; Möckesch, M; Stekel, H; von Schenck, H; Kraft, M; Nagel, R; Hänseler, E

    2001-01-01

    A new reagent carrier, Reflotron ALP, has been developed for the Reflotron system, allowing easy and rapid measurement (in less than 3 minutes) of alkaline phosphatase (ALP) activity in capillary blood, venous blood, heparinized plasma or serum. The evaluation of the analytical performance of the assay was carried out at eight clinical laboratories. The study of the imprecision using the measurements in human samples resulted in coefficients of variation ranging from 1.3% to 4.6% (within-run) and from 3.2% to 4.0% (day-to-day). The analytical specificity of the Reflotron ALP assay agrees well with ALP methods using a N-methyl-D-glucamine buffer solution. The calibration of the Reflotron ALP assay, however, is related to the reference intervals for ALP methods using a diethanolamine buffer solution. Method comparisons were performed with the ALP method on Hitachi instruments using diethanolamine buffer. Reflotron ALP measurements in blood and plasma in 157 randomly selected split samples showed excellent agreement (slope: 0.99; intercept: 0.7 U/l; median bias: 2.3%; median difference from the comparison method: -0.3%). Specimens from pregnant women and adolescents were excluded from this study. Differing values were obtained in a method comparison using 48 samples containing predominantly the ALP bone isoform (slope: 0.81; intercept: 31.5 U/l; median bias: 5.7%; median difference from the comparison method: -12.2%). Regression analysis of the results from 21 sera with prevailing placental ALP gave a slope of 1.51, and an intercept of -41.1 U/l (median bias: 8.6%; median difference from the comparison method: 35.6%). Reflotron ALP was compared with three different wet chemistry procedures using different buffer compounds: N-methyl-D-glucamine or diethanolamine or 2-amino-2-methyl-1-propanol. In samples containing predominantly ALP isoforms not of liver origin, the measurements with N-methyl-D-glucamine buffer gave the best fit with respect to Reflotron. In an

  10. Overloaded elution band profiles of ionizable compounds in reversed-phase liquid chromatography: Influence of the competition between the neutral and the ionic species

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A

    2008-01-01

    The parameters that affect the shape of the band profiles of acido-basic compounds under moderately overloaded conditions (sample size less than 500 nmol for a conventional column) in RPLC are discussed. Only analytes that have a single pK{sub a} are considered. In the buffer mobile phase used for their elution, their dissociation may, under certain conditions, cause a significant pH perturbation during the passage of the band. Two consecutive injections (3.3 and 10 {micro}L) of each one of three sample solutions (0.5, 5, and 50 mM) of ten compounds were injected on five C{sub 18}-bonded packing materials, including the 5 {micro}m Xterra-C{sub 18} (121 {angstrom}), 5 {micro}m Gemini-C{sub 18} (110 {angstrom}), 5 {micro}m Luna-C{sub 18}(2) (93 {angstrom}), 3.5 {micro}m Extend-C{sub 18} (80 {angstrom}), and 2.7 {micro}m Halo-C{sub 18} (90 {angstrom}). The mobile phase was an aqueous solution of methanol buffered at a constant {sub W}{sup W}pH of 6, with a phosphate buffer. The total concentration of the phosphate groups was constant at 50 mM. The methanol concentration was adjusted to keep all the retention factors between 1 and 10. The compounds injected were phenol, caffeine, 3-phenyl 1-propanol, 2-phenyl butyric acid, amphetamine, aniline, benzylamine, p-toluidine, procainamidium chloride, and propranololium chloride. Depending on the relative values of the analyte pK{sub a} and the buffer solution pH, these analytes elute as the neutral, the cationic, or the anionic species. The influence of structural parameters such as the charge, the size, and the hydrophobicity of the analytes on the shape of its overloaded band profile is discussed. Simple but general rules predict these shapes. An original adsorption model is proposed that accounts for the unusual peak shapes observed when the analyte is partially dissociated in the buffer solution during its elution.

  11. Gluconacetobacter medellinensis sp. nov., cellulose- and non-cellulose-producing acetic acid bacteria isolated from vinegar.

    PubMed

    Castro, Cristina; Cleenwerck, Ilse; Trcek, Janja; Zuluaga, Robin; De Vos, Paul; Caro, Gloria; Aguirre, Ricardo; Putaux, Jean-Luc; Gañán, Piedad

    2013-03-01

    The phylogenetic position of a cellulose-producing acetic acid bacterium, strain ID13488, isolated from commercially available Colombian homemade fruit vinegar, was investigated. Analyses using nearly complete 16S rRNA gene sequences, nearly complete 16S-23S rRNA gene internal transcribed spacer (ITS) sequences, as well as concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, allocated the micro-organism to the genus Gluconacetobacter, and more precisely to the Gluconacetobacter xylinus group. Moreover, the data suggested that the micro-organism belongs to a novel species in this genus, together with LMG 1693(T), a non-cellulose-producing strain isolated from vinegar by Kondo and previously classified as a strain of Gluconacetobacter xylinus. DNA-DNA hybridizations confirmed this finding, revealing a DNA-DNA relatedness value of 81 % between strains ID13488 and LMG 1693(T), and values <70 % between strain LMG 1693(T) and the type strains of the closest phylogenetic neighbours. Additionally, the classification of strains ID13488 and LMG 1693(T) into a single novel species was supported by amplified fragment length polymorphism (AFLP) and (GTG)5-PCR DNA fingerprinting data, as well as by phenotypic data. Strains ID13488 and LMG 1693(T) could be differentiated from closely related species of the genus Gluconacetobacter by their ability to produce 2- and 5-keto-d-gluconic acid from d-glucose, their ability to produce acid from sucrose, but not from 1-propanol, and their ability to grow on 3 % ethanol in the absence of acetic acid and on ethanol, d-ribose, d-xylose, sucrose, sorbitol, d-mannitol and d-gluconate as carbon sources. The DNA G+C content of strains ID13488 and LMG 1693(T) was 58.0 and 60.7 mol%, respectively. The major ubiquinone of LMG 1693(T) was Q-10. Taken together these data indicate that strains ID13488 and LMG 1693(T) represent a novel species of the genus Gluconacetobacter for which the name Gluconacetobacter

  12. Volumetric Properties of Dilute Aqueous Solutions of 1- and 2-propanol to 50 MPa and 373.15 K

    NASA Astrophysics Data System (ADS)

    Seitz, J.; Bahramian, J.; Blackwell, R.; Inaki, T.; York, D.; Schulte, M. D.

    2014-12-01

    The need to accurately model and understand reactions among organic compounds and biomolecules in solution is necessary to develop realistic chemical models for the reactions leading to the emergence of life and metabolic processes of extremophiles under elevated temperature and pressure conditions. Unfortunately, the scarcity of experimentally determined volumetric (and other) properties for important compounds at high temperatures and pressures leads to uncertainty in the calculation of reaction properties. Experimentally determined volumetric properties of aqueous solutions at non-standard conditions provide direct tests of current estimation methods and aid in the refinement of these methods. The goal of our research is to provide a database of experimentally determined volumetric properties. In previous studies, we have examined important organic molecules and biomolecules such as adenosine, coenzyme M and D-ribose. In this study, we investigate the volumetric properties of the structural isomers 1- and 2-propanol. 1-propanol (n-propanol) is a primary alcohol (CH3CH2CH2OH) and 2-propanol (isopropanol) is the simplest example of a secondary alcohol (CH3CHOHCH3). These compounds differ slightly in structure depending on to which carbon atom the hydroxyl group is bonded and will provide a sensitive test of current estimation methods and lead to more accurate predictions of the properties of complex aqueous systems at elevated temperatures and pressures. We obtained the densities of aqueous solutions of the alchohols using an Anton Paar DMA HP vibrating tube densimeter. Pressure was measured (pressure transducer) to an accuracy of ±0.01% and temperature was measured (integrated platinum thermometer) with an accuracy of ±0.05 K. Experimental uncertainty of density measurements is less than ±0.0001 g·cm-3. The partial molar volumes at infinite dilution (V∞) for 1- and 2-propanol were calculated from the measured densities and are shown in the figure at 0

  13. Volatile metabolite production of spoilage micro-organisms on a mixed-lettuce agar during storage at 7 degrees C in air and low oxygen atmosphere.

    PubMed

    Ragaert, P; Devlieghere, F; Devuyst, E; Dewulf, J; Van Langenhove, H; Debevere, J

    2006-11-01

    This paper describes the volatile metabolite production of spoilage bacteria (Pantoea agglomerans and Rahnella aquatilis) and spoilage yeasts (Pichia fermentans and Cryptococcus laurentii), previously isolated from mixed lettuce, on a simulation medium of shredded mixed lettuce (mixed-lettuce agar) both under air conditions and modified atmosphere (MA)-conditions at 7 degrees C. These latter conditions simulated the equilibrium modified atmosphere packaging, which is used to extend the shelf-life of shredded mixed lettuce. Besides volatile metabolites, organic acid metabolites and consumption of sugars were measured. Microbiological growth on the mixed-lettuce agar resulted in metabolite production and consumption of sugars. Bacteria and yeasts produced a range of volatile organic compounds both under air conditions and MA-conditions: ethanol, ethyl acetate, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2,3-butanedione, 3-methyl-1-pentanol, 1-butanol and 1-hexanol. Under MA-conditions, 2-methyl-1-butanol, 3-methyl-1-butanol and ethanol were the first compounds that were detected in the headspace as being produced by the inoculated micro-organisms. In the case of the yeast P. fermentans, production of these compounds was detected from a count of 5.0+/-0.1 log cfu/cm(2) with a fast increase when exceeding 6.0-6.5 log cfu/cm(2). Unlike P. fermentans, the yeast C. laurentii showed a slow metabolism under MA-conditions, compared to air conditions. In the case of the bacteria, production of 2-methyl-1-butanol and 3-methyl-1-butanol was detected starting from a count of 6.7+/-0.1 log cfu/cm(2) in the case of R. aquatilis and from a count of 7.1+/-0.4 log cfu/cm(2) in the case of P. agglomerans with a fast increase when exceeding 8 log cfu/cm(2). No production of ethanol by the bacteria under MA-conditions was detected in contradiction to air conditions. It could be concluded that, if these counts are reached on the cut surfaces of shredded mixed lettuce

  14. Aliphatic β-nitroalcohols for therapeutic corneoscleral cross-linking: corneal permeability considerations

    PubMed Central

    Wen, Quan; Trokel, Stephen L.; Paik, David C.

    2012-01-01

    Introduction Our recent tissue cross-linking studies have raised the possibility of using aliphatic β-nitro alcohols (BNAs) for pharmacologic, therapeutic corneal cross-linking. The present study was performed in order to determine the permeability of BNAs and to explore the use of permeability enhancing agents. Methods Ex vivo rabbit corneas were mounted in a typical Franz diffusion chamber. BNA permeability was determined by assaying the recipient chamber over time using a modification of the Griess nitrite colorimetric assay. The apparent permeability coefficient (Ptot) was determined for 2 mono-nitroalcohols, 2-nitroethanol (2NE) and 2-nitro-1-propanol (2NProp); a nitro-diol (2-methyl-2-nitro-1,3-propanediol=MNPD); and a nitro-triol (2-hydroxymethyl-2-nitro-1,3-propanediol=HNPD). Permeability enhancing effects using benzalkonium chloride (BAC) [0.01 and 0.02%], ethylenediaminetetraacetic acid (EDTA) [0.05%], and a combination of BAC 0.01% + tetracaine (TC) [0.5%] were also studied. Results The Ptot (+/−S.E.) values (cm/sec) were as follows: Ptot=4.33×10−5 (+/−9.82×10−6) for 2NE (MW=91), Ptot=9.34×10−6 (+/− 2.16×10−7) for 2NProp (MW=105), Ptot=4.37×10−6 (+/− 1.86×10−7) for MNPD (MW=135), and Ptot=8.95×10−7 (+/−1.93×10−8) for HNPD (MW=151). Using the nitrodiol, permeability increased approximately two-fold using BAC 0.01%, five-fold using BAC 0.02% and five-fold using the combination of BAC 0.01% + TC 0.5%. No effect was observed using EDTA 0.05%. Conclusions The results indicate that the corneal epithelium is permeable to BNAs with the apparent permeability corresponding to molecular weight. The findings are consistent with previous literature indicating that the small size of these compounds (<10Å) favors their passage through the corneal epithelium via the paracellular route. This information will help to guide dosing regimens for in vivo topical cross-linking studies. PMID:22868628

  15. The Effect of Cavitating Ultrasound on the Aqueous Phase Hydrogenation of Cis-2-buten-1-ol and Cis-2-penten-1-ol on Pd-black

    SciTech Connect

    Disselkamp, Robert S.; Denslow, Kayte M.; Hart, Todd R.; White, James F.; Peden, Charles HF.

    2005-07-15

    We have studied the effect of cavitating ultrasound on the heterogeneous aqueous hydrogenation of cis-2-buten-1-ol (C4 olefin) and cis-2-penten-1-ol (C5 olefin) on Pd-black to form the trans-olefins (trans-2-buten-1-ol and trans-2-penten-1-ol) and saturated alcohols (1-butanol and 1-pentanol, respectively). Silent (and magnetically stirred) experiments served as control experiments. As described in an earlier publication by our group, we have added an inert dopant, 1-propanol, in the reaction mixture to ensure the rapid onset of cavitation in the ultrasound-assisted reactions that can lead to altered selectivity compared to silent reaction systems [Disselkamp et al., J. Catal., 227 (2004) 552]. The motivation for this study is to examine whether cavitating ultrasound can reduce the [trans-olefin/saturated alcohol] molar ratio during the course of the reaction. This could have practical application in that it may offer an alternative processing methodology of synthesizing healthier edible seed oils by reducing trans-fat content. We have observed that cavitating ultrasound results in a [(trans-olefin/saturated alcohol)ultrasound/(trans-olefin/saturated alcohol)silent] ratio quantity less than 0.5 at the reaction mid-point for both the C4 and C5 olefin systems. This indicates that ultrasound reduces trans-olefin production compared to the silent control experiment. Furthermore, there is an added 30% reduction for the C5 versus C4 olefin compounds again at reaction mid-point. We attribute differences in the ratio quantity as a moment of inertia effect. In principle, the C4 versus C5 olefins has a {approx}52% increase in moment of inertia about C2=C3 double bond slowing isomerization. Since seed oils are C18 multiple cis olefins and have an moment of inertia even greater than our C5 olefin here, our study suggests that even a greater reduction in trans-olefin content may occur for partial hydrogenation of C18 seed oils.

  16. The effect of cavitating ultrasound on the aqueous phase hydrogenation of cis-2-buten-1-ol and cis-2-penten-1-ol on Pd-black

    SciTech Connect

    Disselkamp, Robert S.; Denslow, Kayte M.; Hart, Todd R.; White, James F.; Peden, Charles HF.

    2005-07-15

    We have studied the effect of cavitating ultrasound on the heterogeneous aqueous hydrogenation of cis-2-buten-1-ol (C4 olefin) and cis-2-penten-1-ol (C5 olefin) on Pd-black to form the trans-olefins (trans-2-buten-1-ol and trans-2-penten-1-ol) and saturated alcohols (1-butanol and 1-pentanol, respectively). Silent (and magnetically stirred) experiments served as control experiments. As described in an earlier publication by our group, we have added an inert dopant, 1-propanol, in the reaction mixture to ensure the rapid onset of cavitation in the ultrasound-assisted reactions that can lead to altered selectivity compared to silent reaction systems [R.S. Disselkamp, Ya-Huei Chin, C.H.F. Peden, J. Catal. 227 (2004) 552]. The motivation for this study is to examine whether cavitating ultrasound can reduce the [trans-olefin/saturated alcohol] molar ratio during the course of the reaction. This could have practical application in that it may offer an alternative processing methodology of synthesizing healthier edible seed oils by reducing trans-fat content.We have observed that cavitating ultrasound results in a [(trans-olefin/saturated alcohol)ultrasound/(trans-olefin/saturated alcohol)silent] ratio quantity less than 0.5 at the reaction mid-point for both the C4 and C5 olefin systems. This indicates that ultrasound reduces trans-olefin production compared to the silent control experiment. Furthermore, there is an added 30% reduction for the C5 versus C4 olefin compounds again at reaction mid-point. We attribute differences in the ratio quantity as a moment of inertia effect. In principle, the C4 versus C5 olefins has a {approx}52% increase in moment of inertia about C2 C3 double bond slowing isomerization. Since seed oils are C18 multiple cis-olefins and have a moment of inertia even greater than our C5 olefin here, our study suggests that even a greater reduction in trans-olefin content may occur for partial hydrogenation of C18 seed oils.

  17. Liquid-feed flame spray pyrolysis synthesis of oxide nanopowders for the processing of ceramic composites

    NASA Astrophysics Data System (ADS)

    Taylor, Nathan John

    In the liquid-feed flame spray pyrolysis (LF-FSP) process, alcohol solutions of metalloorganic precursors are aerosolized by O2 and combusted. The metal oxide combustion products are rapidly quenched (< 10 ms) from flame temperatures of 1500°C to temperatures < 400° C, limiting particle growth. The resulting nanopowders are typically agglomerated but unaggregated. Here, we demonstrate two processing approaches to dense materials: nanopowders with the exact composition, and mixed single metal oxide nanopowders. The effect of the initial degree of phase separation on the final microstructures was determined by sintering studies. Our first studies included the production of yttrium aluminum garnet, Y3Al5O12 (YAG), tubes which we extruded from a thermoplastic/ceramic blend. At equivalent final densities, we found finer grain sizes in the from the mixed Y2O3 and Al2 O3 nanopowders, which was attributed to densification occurring before full transformation to the YAG phase. The enhanced densification in production of pure YAG from the reactive sintering process led us to produce composites in the YAG/alpha-Al 2O3 system. Finally, a third Y2O3 stabilized ZrO2 (YSZ) phase was added to further refine grain sizes using the same two processing approaches. In a separate study, single-phase metastable Al2O3 rich spinels with the composition MO•3Al 2O3 where M = Mg, Ni, and Co were sintered to produce dense MAl2O4/alpha-Al2O3 composites. All of these studies provide a test of the bottom-up approach; that is, how the initial length scale of mixing affects the final composite microstructure. Overall, the length scale of mixing is highly dependent upon the specific oxide composites studied. This work provides a processing framework to be adopted by other researchers to further refine microstructural size. LF-FSP flame temperatures were mapped using different alcohols with different heats of combustion: methanol, ethanol, 1-propanol, and n-butanol. The effect of different

  18. Initial Studies Using Aliphatic β-Nitro Alcohols for Therapeutic Corneal Cross-Linking

    PubMed Central

    Paik, David C.; Wen, Quan; Braunstein, Richard E.; Airiani, Suzanna; Trokel, Stephen L.

    2009-01-01

    Purpose Corneal collagen cross-linking through UVA-riboflavin photochemistry (UVAR) has been shown to be an effective treatment for keratoconus and related keratectasias. In recent studies using sclera, the authors observed that short-chain aliphatic β-nitro alcohols can cross-link collagenous tissue under physiologic conditions. Thus, this study was undertaken to evaluate these agents as potential pharmacologic alternatives to UVAR. Methods Porcine corneal strips (8 × 4 mm) and corneoscleral complexes were cross-linked using 1 to 100 mM 2-nitroethanol (2ne), 2-nitro-1-propanol (2nprop), and 3-nitro-2-pentanol (3n2pent) at pH 7.4, 34°C. Cross-linking by UVAR was carried out for comparison. Thermal shrinkage temperature analysis was used to evaluate cross-linking effects, and changes in corneal light transmission were determined with a fiber-optic spectrophotometer. Results At 10 and 100 mM for 96 hours, initial shrinkage temperature (Ti) was shifted by 3.3°C (P < 0.001) and 9.8°C (P < 0.001) for 2ne, 2.9°C (P = 0.008) and 4.9°C (P < 0.001) for 2nprop, and 3.8°C (P = 0.003) and 4.9°C (P < 0.001) for 3n2pent. Reacting at 1 mM through daily exchange of fluid over 7 days shifted Ti by 3.8°C (P < 0.001), 4.4°C (P = 0.002), and 3.2°C (P = 0.005), for 2ne, 2nprop, and 3n2pent, respectively. These shifts were greater than cross-linking using UVAR (Ti = 1.9°C; P = 0.012). In the blue light region (400−500 nm), transmission was decreased by 5.6% (P = 0.003), 2.1% (P = 0.260), and 0% (P = 0.428) for 2ne, 2nprop, and 3n2pent, respectively. Conclusions β-Nitro alcohols can induce corneal cross-linking in vitro better than the UVAR technique and can induce negligible effects on light transmission. These early results suggest that such compounds could be used as topical stiffening agents for keratoconus and related disorders. PMID:18836172

  19. Hygienic safety of alcohol-based hand disinfectants and skin antiseptics.

    PubMed

    Steinhauer, Katrin; Meyer, Bernhard; Ostermeyer, Christiane; Rödger, Hans-Joachim; Hintzpeter, Matthias

    2013-01-01

    Hintergrund: Ziel dieser Untersuchung war die Klärung der Fragestellung, inwiefern eine Kontamination alkoholbasierter Händedesinfektionsmittel und Antiseptika mit bakteriellen Sporen ein gesundheitliches Risiko darstellen kann. Dabei wurde insbesondere die Möglichkeit einer Kontamination mit bakteriellen Sporen im Zuge des Produktionsprozesses sowie der späteren Verwendung untersucht.Methode: Es wurden umfangreiche mikrobiologische Untersuchungen der Primärpackmittel durchgeführt, um den mikrobiologischen Status bewerten zu können. Des Weiteren wurde die Langzeitüberlebensfähigkeit bakterieller Sporen in Alkohol untersucht. Dabei wurde sporulierter B. subtilis ATCC 6633 als Standardtestorganismus verwendet. Die Untersuchung der mikrobiellen Kontamination während der Anwendung wurde über einen Zeitraum von 12 Monaten unter praktischen Bedingungen untersucht. Dabei wurden mikrobiologische und physiko-chemische Daten erhoben.Ergebnisse: Von insgesamt 625 untersuchten Primärverpackungen konnte bei 542 Verpackungen keinerlei mikrobielle Kontamination nachgewiesen werden. Der Median lag insgesamt bei 0,2 cfu/10 ml Verpackungsgefäß in Bezug auf aerobe sporenbildende Bakterien. Es wurden keine anaeroben sporenbildenden Bakterien gefunden. Die Untersuchung ergab weiterhin, dass aliphatische C2–C3 Alkohole die Lebensfähigkeit bakterieller Sporen beeinträchtigen. Dabei zeigte 1-Propanol die beste Wirksamkeit. 2-Propanol und Ethanol waren ebenfalls wirksam, jedoch in geringerem Umfang. Im Rahmen der Anwendungstests wurden keinerlei Veränderungen der physiko-chemischen Daten detektiert. Des Weiteren wurde keinerlei mikrobielle Kontamination über den gesamten Anwendungszeitraum nachgewiesen.Diskussion: Die Daten dieser Untersuchung zeigen, dass mit Hilfe moderner Produktionsprozesse hergestellte alkoholbasierte Händedesinfektionsmittel und Antiseptika als mikrobiologisch sicher betrachtet werden können. Die Untersuchung von Primärpackmitteln und

  20. Insights on Alterations to the Rumen Ecosystem by Nitrate and Nitrocompounds

    PubMed Central

    Latham, Elizabeth A.; Anderson, Robin C.; Pinchak, William E.; Nisbet, David J.

    2016-01-01

    Nitrate and certain short chain nitrocompounds and nitro-oxy compounds are being investigated as dietary supplements to reduce economic and environmental costs associated with ruminal methane emissions. Thermodynamically, nitrate is a preferred electron acceptor in the rumen that consumes electrons at the expense of methanogenesis during dissimilatory reduction to an intermediate, nitrite, which is primarily reduced to ammonia although small quantities of nitrous oxide may also be produced. Short chain nitrocompounds act as direct inhibitors of methanogenic bacteria although certain of these compounds may also consume electrons at the expense of methanogenesis and are effective inhibitors of important foodborne pathogens. Microbial and nutritional consequences of incorporating nitrate into ruminant diets typically results in increased acetate production. Unlike most other methane-inhibiting supplements, nitrate decreases or has no effect on propionate production. The type of nitrate salt added influences rates of nitrate reduction, rates of nitrite accumulation and efficacy of methane reduction, with sodium and potassium salts being more potent than calcium nitrate salts. Digestive consequences of adding nitrocompounds to ruminant diets are more variable and may in some cases increase propionate production. Concerns about the toxicity of nitrate's intermediate product, nitrite, to ruminants necessitate management, as animal poisoning may occur via methemoglobinemia. Certain of the naturally occurring nitrocompounds, such as 3-nitro-1-propionate or 3-nitro-1-propanol also cause poisoning but via inhibition of succinate dehydrogenase. Typical risk management procedures to avoid nitrite toxicity involve gradually adapting the animals to higher concentrations of nitrate and nitrite, which could possibly be used with the nitrocompounds as well. A number of organisms responsible for nitrate metabolism in the rumen have been characterized. To date a single rumen bacterium

  1. Microstructure investigation on micropore formation in microporous silica materials prepared via a catalytic sol-gel process by small angle X-ray scattering.

    PubMed

    Shimizu, Wataru; Hokka, Junsuke; Sato, Takaaki; Usami, Hisanao; Murakami, Yasushi

    2011-08-01

    The so-called sol-gel technique has been shown to be a template-free, efficient way to create functional porous silica materials having uniform micropores. This appears to be closely linked with a postulation that the formation of weakly branched polymer-like aggregates in a precursor solution is a key to the uniform micropore generation. However, how such a polymer-like structure can precisely be controlled, and further, how the generated low-fractal dimension solution structure is imprinted on the solid silica materials still remain elusive. Here we present fabrication of microporous silica from tetramethyl orthosilicate (TMOS) using a recently developed catalytic sol-gel process based on a nonionic hydroxyacetone (HA) catalyst. Small angle X-ray scattering (SAXS), nitrogen adsorption porosimetry, and transmission electron microscope (TEM) allowed us to observe the whole structural evolution, ranging from polymer-like aggregates in the precursor solution to agglomeration with heat treatment and microporous morphology of silica powders after drying and hydrolysis. Using the HA catalyst with short chain monohydric alcohols (methanol or ethanol) in the precursor solution, polymer-like aggregates having microscopic correlation length (or mesh-size) < 2 nm and low fractal dimensions ∼2, which is identical to that of an ideal coil polymer, can selectively be synthesized, yielding the uniform micropores with diameters <2 nm in the solid materials. In contrast, the absence of HA or substitution of 1-propanol led to considerably different scattering behavior reflecting the particle-like aggregate formation in the precursor solution, which resulted in the formation of mesopores (diameter >2 nm) in the solid product due to apertures between the particle-like aggregates. The data demonstrate that the extremely fine porous silica architecture comes essentially from a gaussian polymer-like nature of the silica aggregates in the precursor having the microscopic mesh-size and

  2. The effect of thiolated additives on the properties of wheat gluten based plastics, aqueous solutions and electrospun fibers

    NASA Astrophysics Data System (ADS)

    Dong, Jing

    Wheat gluten (WG) is a promising substitute for petroleum-based plastics due to its unique ability to form a cohesive blend with viscoelastic properties once plasticized. Previous work blending WG with thiolated poly(vinyl alcohol) (TPVA) showed that both the strength and elongation of compression molded native WG bars can be improved via thiol/disulfide interchange reactions between WG and TPVA. In this study, the morphology of WG/TPVA blends was investigated by atomic force (AFM) and transmission electron microscopy (TEM), as well as by modulated dynamic scanning calorimetry (MDSC). Consistent with our earlier results, AFM and TEM imaging clearly indicated that TPVA is much more compatible with WG compared with poly(vinyl alcohol) (PVA) although there are still two phases in the blend: one WG rich phase and another TPVA rich phase. TPVA was also blended with WG in an aqueous solvent (1/1 (v/v) water/1-propanol mixture) to improve its solubility and spinnability. Control experiments were conducted with PVA and dithiothreitol (DTT) for comparison purposes. The concentration and the thiolation level of TPVA were also varied to explore the parameter space. The interactions of thiol groups from TPVA and soluble WG were found to be important during electrospinning. The fiber diameter became more uniform and the fiber quality increased very noticeably when TPVA was included. Furthermore, the time-dependent rheology behaviors of TPVA/WG and DTT/WG electrospinning solutions were investigated by using steady shear sweeps, oscillatory frequency sweeps, SE-HPLC and free -SH content determination. A two-step mechanism of interaction was proposed for DTT/WG and TPVA/WG solutions based on current results and other earlier studies. In comparison with WG and PVA/WG solutions, the reduction and reformation of disulfide linkages in both TPVA/WG and DTT/WG solutions were believed to play a key role in determining the rheological properties and molecular weight distribution of WG

  3. Enneanuclear [Ni6Ln3] Cages: [Ln(III)3] Triangles Capping [Ni(II)6] Trigonal Prisms Including a [Ni6Dy3] Single-Molecule Magnet.

    PubMed

    Canaj, Angelos B; Tzimopoulos, Demetrios I; Siczek, Milosz; Lis, Tadeusz; Inglis, Ross; Milios, Constantinos J

    2015-07-20

    The use of (2-(β-naphthalideneamino)-2-hydroxymethyl-1-propanol) ligand, H3L, in Ni/Ln chemistry has led to the isolation of three new isostructural [Ni(II)6Ln(III)3] metallic cages. More specifically, the reaction of Ni(ClO4)2·6H2O, the corresponding lanthanide nitrate salt, and H3L in MeCN, under solvothermal conditions in the presence of NEt3, led to the isolation of three complexes with the formulas [Ni6Gd3(OH)6(HL)6(NO3)3]·5.75MeCN·2Et2O·1.5H2O (1·5.75MeCN·2Et2O·1.5H2O), [Ni6Dy3(OH)6(HL)6(NO3)3]·2MeCN·2.7Et2O·2.4H2O (2·2MeCN·2.7Et2O·2.4H2O), and [Ni6Er3(OH)6(HL)6(NO3)3]·5.75MeCN·2Et2O·1.5H2O (3·5.75MeCN·2Et2O·1.5H2O). The structure of all three clusters describes a [Ln(III)3] triangle capping a [Ni(II)6] trigonal prism. Direct current magnetic susceptibility studies in the 5-300 K range for complexes 1-3 reveal the different nature of the magnetic interactions within the clusters: dominant antiferromagnetic exchange interactions for the Dy(III) and Er(III) analogues and dominant ferromagnetic interactions for the Gd(III) example. Alternating current magnetic susceptibility measurements under zero external dc field displayed fully formed temperature- and frequency-dependent out-of-phase peaks for the [Ni(II)6Dy(III)3] analogue, establishing its single molecule magnetism behavior with Ueff = 24 K.

  4. Insights on Alterations to the Rumen Ecosystem by Nitrate and Nitrocompounds.

    PubMed

    Latham, Elizabeth A; Anderson, Robin C; Pinchak, William E; Nisbet, David J

    2016-01-01

    Nitrate and certain short chain nitrocompounds and nitro-oxy compounds are being investigated as dietary supplements to reduce economic and environmental costs associated with ruminal methane emissions. Thermodynamically, nitrate is a preferred electron acceptor in the rumen that consumes electrons at the expense of methanogenesis during dissimilatory reduction to an intermediate, nitrite, which is primarily reduced to ammonia although small quantities of nitrous oxide may also be produced. Short chain nitrocompounds act as direct inhibitors of methanogenic bacteria although certain of these compounds may also consume electrons at the expense of methanogenesis and are effective inhibitors of important foodborne pathogens. Microbial and nutritional consequences of incorporating nitrate into ruminant diets typically results in increased acetate production. Unlike most other methane-inhibiting supplements, nitrate decreases or has no effect on propionate production. The type of nitrate salt added influences rates of nitrate reduction, rates of nitrite accumulation and efficacy of methane reduction, with sodium and potassium salts being more potent than calcium nitrate salts. Digestive consequences of adding nitrocompounds to ruminant diets are more variable and may in some cases increase propionate production. Concerns about the toxicity of nitrate's intermediate product, nitrite, to ruminants necessitate management, as animal poisoning may occur via methemoglobinemia. Certain of the naturally occurring nitrocompounds, such as 3-nitro-1-propionate or 3-nitro-1-propanol also cause poisoning but via inhibition of succinate dehydrogenase. Typical risk management procedures to avoid nitrite toxicity involve gradually adapting the animals to higher concentrations of nitrate and nitrite, which could possibly be used with the nitrocompounds as well. A number of organisms responsible for nitrate metabolism in the rumen have been characterized. To date a single rumen bacterium

  5. Porcine Sapelovirus Uses α2,3-Linked Sialic Acid on GD1a Ganglioside as a Receptor

    PubMed Central

    Kim, Deok-Song; Son, Kyu-Yeol; Koo, Kyung-Min; Kim, Ji-Yun; Alfajaro, Mia Madel; Park, Jun-Gyu; Hosmillo, Myra; Soliman, Mahmoud; Baek, Yeong-Bin; Cho, Eun-Hyo; Lee, Ju-Hwan; Kang, Mun-Il

    2016-01-01

    ABSTRACT The receptor(s) for porcine sapelovirus (PSV), which causes diarrhea, pneumonia, polioencephalomyelitis, and reproductive disorders in pigs, remains largely unknown. Given the precedent for other picornaviruses which use terminal sialic acids (SAs) as receptors, we examined the role of SAs in PSV binding and infection. Using a variety of approaches, including treating cells with a carbohydrate-destroying chemical (NaIO4), mono- or oligosaccharides (N-acetylneuraminic acid, galactose, and 6′-sialyllactose), linkage-specific sialidases (neuraminidase and sialidase S), lectins (Maakia amurensis lectin and Sambucus nigra lectin), proteases (trypsin and chymotrypsin), and glucosylceramide synthase inhibitors (dl-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol and phospholipase C), we demonstrated that PSV could recognize α2,3-linked SA on glycolipids as a receptor. On the other hand, PSVs had no binding affinity for synthetic histo-blood group antigens (HBGAs), suggesting that PSVs could not use HBGAs as receptors. Depletion of cell surface glycolipids followed by reconstitution studies indicated that GD1a ganglioside, but not other gangliosides, could restore PSV binding and infection, further confirming α2,3-linked SA on GD1a as a PSV receptor. Our results could provide significant information on the understanding of the life cycle of sapelovirus and other picornaviruses. For the broader community in the area of pathogens and pathogenesis, these findings and insights could contribute to the development of affordable, useful, and efficient drugs for anti-sapelovirus therapy. IMPORTANCE The porcine sapelovirus (PSV) is known to cause enteritis, pneumonia, polioencephalomyelitis, and reproductive disorders in pigs. However, the receptor(s) that the PSV utilizes to enter host cells remains largely unknown. Using a variety of approaches, we showed that α2,3-linked terminal sialic acid (SA) on the cell surface GD1a ganglioside could be used for PSV

  6. Cross-linked gold nanoparticles on polyethylene: resistive responses to tensile strain and vapors.

    PubMed

    Olichwer, Natalia; Leib, Elisabeth W; Halfar, Annelie H; Petrov, Alexey; Vossmeyer, Tobias

    2012-11-01

    In this study, coatings of cross-linked gold nanoparticles (AuNPs) on flexible polyethylene (PE) substrates were prepared via layer-by-layer deposition and their application as strain gauges and chemiresistors was investigated. Special emphasis was placed on characterizing the influence of strain on the chemiresistive responses. The coatings were deposited using amine stabilized AuNPs (4 and 9 nm diameter) and 1,9-nonanedithiol (NDT) or pentaerythritol tetrakis(3-mercaptopropionate) (PTM) as cross-linkers. To prepare films with homogeneous optical appearance, it was necessary to treat the substrates with oxygen plasma directly before film assembly. SEM images revealed film thicknesses between ∼60 and ∼90 nm and a porous nanoscale morphology. All films showed ohmic I-V characteristics with conductivities ranging from 1 × 10⁻⁴ to 1 × 10⁻² Ω⁻¹ cm⁻¹, depending on the structure of the linker and the nanoparticle size. When up to 3% strain was induced their resistance increased linearly and reversibly (gauge factors: ∼20). A comparative SEM investigation indicated that the stress induced formation and extension of nanocracks are important components of the signal transduction mechanism. Further, all films responded with a reversible increase in resistance when dosed with toluene, 4-methyl-2-pentanone, 1-propanol or water vapor (concentrations: 50-10 000 ppm). Films deposited onto high density PE substrates showed much faster response-recovery dynamics than films deposited onto low density PE. The chemical selectivity of the coatings was controlled by the chemical nature of the cross-linkers, with the highest sensitivities (∼1 × 10⁻⁵ ppm⁻¹) measured with analytes of matching solubility. The response isotherms of all film/vapor pairs could be fitted using a Langmuir-Henry model suggesting selective and bulk sorption. Under tensile stress (1% strain) all chemiresistors showed a reversible increase in their response amplitudes (∼30

  7. Reactivity trends in reactions of the nitrate radical (NO[sub 3]) with inorganic and organic cloudwater constituents

    SciTech Connect

    Herrmann, H.; Exner, M.; Zellner, R. )

    1994-08-01

    NO[sub 3] radicals were produced by excimer laser photolysis of peroxodisulfate anions in the presence of excess nitrate. For the time-resolved detection of NO[sub 3], a sensitive laser long path absorption technique at 632.8 nm was applied. For the reaction of NO[sub 3] with H[sub 2]O[sub 2] the temperature dependent rate coefficient was found to be k[sub 1](T) = (4.0 [+-] 0.5)[center dot]10[sup 9] exp[-(2000 [+-] 850)/T] L mol[sup [minus]1] s[sup [minus]1], corresponding to k[sub 1] = (7.0 [+-] 1.2)[center dot]10[sup 6] L mol[sup [minus]1] s[sup [minus]1] at 298 K. The rate coefficients of the reactions of NO[sub 3] with acetone, tetrahydrofuran, and hydrated formaldehyde were determined at T = 298 K to be k[sub 2] = (4.4 [+-] 0.6)[center dot]10[sup 3] L mol[sup [minus]1] s[sup [minus]1], k[sub 3] = (2.1 [+-] 0.1)[center dot]10[sup 7] L mol[sup [minus]1] s[sup [minus]1], and k[sub 4] = (7.8 [+-] 1.2)[center dot]10[sup 5] L mol[sup [minus]1] s[sup [minus]1], respectively. For the reactions of NO[sub 3] with the alcohols methanol, ethanol, 1-propanol, 2-propanol, and 2-methyl-2-propanol the following rate constants at T = 298 K were obtained: k[sub 5] = (5.1 [+-] 0.3)[center dot]10[sup 5] L mol[sup [minus]1] s[sup [minus]1], k[sub 6] = (2.4 [+-] 0.5)[center dot]10[sup 6] L mol[sup [minus]1] s[sup [minus]1], k[sub 7] = (3.2 [+-] 0.1)[center dot]10[sup 6] L mol[sup [minus]1] s[sup [minus]1], k[sub 8] = (3.7 [+-] 0.9)[center dot]10[sup 6] L mol[sup [minus]1] s[sup [minus]1], and k[sub 9] = (6.6 [+-] 0.7)[center dot]10[sup 4] L mol[sup [minus]1] s[sup [minus]1], respectively. A linear relationship between the logarithm of the rate coefficients and C-H bond dissociation energies was found, which is described by the expression lg (k[sub NO[sub 3

  8. Dip-angle influence on areal DNAPL recovery by co-solvent flooding with and without pre-flooding.

    PubMed

    Boyd, Glen R; Li, Minghua; Husserl, Johana; Ocampo-Gómez, Ana M

    2006-01-10

    A two-dimensional (2D) laboratory model was used to study effects of gravity on areal recovery of a representative dense non-aqueous phase liquid (DNAPL) contaminant by an alcohol pre-flood and co-solvent flood in dipping aquifers. Recent studies have demonstrated that injection of alcohol and co-solvent solutions can be used to reduce in-situ the density of DNAPL globules and displace the contaminant from the source zone. However, contact with aqueous alcohol reduces interfacial tension and causes DNAPL swelling, thus facilitating risk of uncontrolled downward DNAPL migration. The 2D laboratory model was operated with constant background gradient flow and a DNAPL spill was simulated using tetrachloroethene (PCE). The spill was dispersed to a trapped, immobile PCE saturation by a water flood. Areal PCE recovery was studied using a double-triangle well pattern to simulate a remediation scheme consisting of an alcohol pre-flood using aqueous isobutanol ( approximately 10% vol.) followed by a co-solvent flood using a solution of ethylene glycol (65%) and 1-propanol (35%). Experiments were conducted with the 2D model oriented in the horizontal plane and compared to experiments at the 15 degrees and 30 degrees dip-angle orientations. Injection was applied either in the downward or upward direction of flow. Experimental results were compared to theoretical predictions for flood front stability and used to evaluate effects of gravity on areal PCE recovery. Sensitivity experiments were performed to evaluate effects of the alcohol pre-flood on PCE areal recovery. For experiments conducted with the alcohol pre-flood and the 2D model oriented in the horizontal plane, results indicate that 89-93% of source zone PCE was recovered. With injection oriented downward, results indicate that areal PCE recovery was 70-77% for a 15 degrees dip angle and 57-59% for a 30 degrees dip angle. With injection oriented upward, results indicate that areal PCE recovery was 57-60% at the 30

  9. Dexamethasone modulates rat renal brush border membrane phosphate transporter mRNA and protein abundance and glycosphingolipid composition.

    PubMed Central

    Levi, M; Shayman, J A; Abe, A; Gross, S K; McCluer, R H; Biber, J; Murer, H; Lötscher, M; Cronin, R E

    1995-01-01

    Glucocorticoids are important regulators of renal phosphate transport. This study investigates the role of alterations in renal brush border membrane (BBM) sodium gradient-dependent phosphate transport (Na-Pi cotransporter) mRNA and protein abundance in the dexamethasone induced inhibition of Na-Pi cotransport in the rat. Dexamethasone administration for 4 d caused a 1.5-fold increase in the Vmax of Na-Pi cotransport (1785 +/- 119 vs. 2759 +/- 375 pmol/5 s per mg BBM protein in control, P < 0.01), which was paralleled by a 2.5-fold decrease in the abundance of Na-Pi mRNA and Na-Pi protein. There was also a 1.7-fold increase in BBM glucosylceramide content (528 +/- 63 vs. 312 +/- 41 ng/mg BBM protein in control, P < 0.02). To determine whether the alteration in glucosylceramide content per se played a functional role in the decrease in Na-Pi cotransport, control rats were treated with the glucosylceramide synthase inhibitor, D-threo-1-phenyl-2-decanoyl-amino-3-morpholino-1-propanol (PDMP). The resultant 1.5-fold decrease in BBM glucosylceramide content (199 +/- 19 vs. 312 +/- 41 ng/mg BBM protein in control, P < 0.02) was associated with a 1.4-fold increase in Na-Pi cotransport activity (1422 +/- 73 vs. 1048 +/- 85 pmol/5 s per mg BBM protein in control, P < 0.01), and a 1.5-fold increase in BBM Na-Pi protein abundance. Thus, dexamethasone-induced inhibition of Na-Pi cotransport is associated with a decrease in BBM Na-Pi cotransporter abundance, and an increase in glucosylceramide. Since primary alteration in BBM glucosylceramide content per se directly and selectively modulates BBM Na-Pi cotransport activity and Na-Pi protein abundance, we propose that the increase in BBM glucosylceramide content plays an important role in mediating the inhibitory effect of dexamethasone on Na-Pi cotransport activity. Images PMID:7615789

  10. Thermodynamics of Organic Compound Alteration in Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Shock, E. L.

    2005-12-01

    Organic compounds enter hydrothermal systems through infiltrating surface waters, zones of microbial productivity in the subsurface, extracts of organic matter in surrounding host rocks, and abiotic synthesis. Owing to variations in pH, oxidation state, composition, temperature, and pressure throughout the changing pathways of fluid migration over the duration of the system, organic compounds from all of these sources are introduced to conditions where their relative stabilities and reactivities can be dramatically transformed. If those transformations were predictable, then the extent to which organic alteration reactions have occurred could be used to reveal flowpaths and histories of hydrothermal systems. Speciation and mass transfer calculations permit some insight into the underlying thermodynamic driving forces that result in organic compound alteration. As an example, the speciation of many geochemist's canonical organic matter: CH2O depends strongly on oxidation state, temperature, and total concentration of dissolved organic matter. Calculations show that at oxidation states buffered by iron-bearing mineral assemblages, organic acids dominate the speciation of CH2O throughout hydrothermal systems, with acetic acid (itself equivalent to 2 CH2O by bulk composition) and propanoic acid generally the most abundant compounds. However, at more reduced conditions, which may prevail in organic-rich iron-poor sediments, the drive is to form ketones and especially alcohols at the expense of organic acids. The distribution of organic carbon among the various members of these compound classes is strongly dependent on the total concentration of dissolved organic matter. As an example, at a bulk concentration equivalent to average dissolved organic matter in seawater (45μm), the dominant alcohols at 100°C are small compounds like ethanol and 1-propanol. In contrast, at a higher bulk concentration of 500μm, there is a drive to shift large percentages of dissolved

  11. Peak shapes of acids and bases under overloaded conditions in reversed-phase liquid chromatography, with weakly buffered mobile phases of various pH: A thermodynamic interpretation

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A

    2009-01-01

    We measured overloaded band profiles for a series of nine compounds (phenol, caffeine, 3-phenyl 1-propanol, 2-phenylbutyric acid, amphetamine, aniline, benzylamine, p-toluidine, and procainamidium chloride) on columns packed with four different C{sub 18}-bonded packing materials: XTerra-C{sub 18}, Gemini-C{sub 18}, Luna-C{sub 18}(2), and Halo-C{sub 18}, using buffered methanol-water mobile phases. The {sub W}{sup S}pH of the mobile phase was increased from 2.6 to 11.3. The buffer concentration (either phosphate, acetate, or carbonate buffers) was set constant at values below the maximum concentration of the sample in the band. The influence of the surface chemistry of the packing material on the retention and the shape of the peaks was investigated. Adsorbents having a hybrid inorganic/organic structure tend to give peaks exhibiting moderate or little tailing. The retention and the shape of the band profiles can easily be interpreted at {sub W}{sup S}pHs that are well above or well below the {sub W}{sup S}pK{sub a} of the compound studied. In contrast, the peak shapes in the intermediary pH range (i.e., close to the compound {sub W}{sup S}pK{sub a}) have rarely been studied. These shapes reveal the complexity of the competitive adsorption behavior of couples of acido-basic conjugated compounds at {sub W}{sup S}pHs that are close to their {sub W}{sup S}pK{sub a}. They also reveal the role of the buffer capacity on the resulting peak shape. With increasing {sub W}{sup S}pH, the overloaded profiles are first langmuirian (isotherm type I) at low {sub W}{sup S}pHs, they become S-shaped (isotherm type II), then anti-langmuirian (isotherm type III), S-shaped again at intermediate {sub W}{sup S}pHs, and finally return to a langmuirian shape at high {sub W}{sup S}pHs. A new general adsorption isotherm model that takes into account the dissociation equilibrium of conjugated acidic and basic species in the bulk mobile phase accounts for these transient band shapes. An

  12. Supercritical carbon dioxide-soluble ligands for extracting actinide metal ions from porous solids (EMSP Project Number 64965)

    SciTech Connect

    Dietz, M. L.; Barrans, Jr., R. E.; Herlinger, A. W.; Brennecke, J. F.

    2000-04-24

    The objective of this project is to develop novel, substituted diphosphonic acid ligands that can be used for supercritical carbon dioxide extraction (SCDE) of actinide ions from solid wastes. Specifically, selected diphosphonic acids, which are known to form extremely stable complexes with actinides in aqueous and organic solution, are to be rendered carbon dioxide-soluble by the introduction of appropriate alkyl- or silicon-containing substituents. The metal complexation chemistry of these new ligands in SC-CO{sub 2} will then be investigated and techniques for their use in actinide extraction from porous solids developed. This report summarizes the work performed during the first 1.3 years of a 3-year program. Because the planned studies of metal complexation and the development of techniques for actinide removal from solids are dependent on the availability of suitable ligands, efforts to date have focused primarily on the synthesis of selected alkyl- or silicon-containing diphosphonic acids. The authors' principal targets have been derivatives in which the silicon-containing groups either serve as the ester function or are attached to the anchor carbon of the diphosphonic acid. Because methylenediphosphonic acid (MDPA) is commercially available and because its esterification with simple alcohols to yield symmetrical diesters is well-established, their initial studies have focused on this ligand and its reactions with silyl alcohols. Success has been achieved in the reaction of MDPA and its ethylene, propylene, and butylene analogs with 3-(trimethylsilyl)-1-propanol. Using a procedure similar to that previously employed for the synthesis of C-8 dialkylmethylenediphosphonic acids, this series of alkylenediphosphonic acids has been esterified in good yield (ca. 60%) to the symmetrically-substituted diesters. Vapor phase osmometric and cryoscopic studies of these compounds in toluene and 1-decanol, respectively, indicate that their aggregation properties closely

  13. Oxygenates vs. synthesis gas

    SciTech Connect

    Kamil Klier; Richard G. Herman; Alessandra Beretta; Maria A. Burcham; Qun Sun; Yeping Cai; Biswanath Roy

    1999-04-01

    Methanol synthesis from H{sub 2}/CO has been carried out at 7.6 MPa over zirconia-supported copper catalysts. Catalysts with nominal compositions of 10/90 mol% and 30/70 mol% Cu/ZrO{sub 2} were used in this study. Additionally, a 3 mol% cesium-doped 10/90 catalyst was prepared to study the effect of doping with heavy alkali, and this promoter greatly increased the methanol productivity. The effects of CO{sub 2} addition, water injection, reaction temperature, and H{sub 2}/C0 ratio have been investigated. Both CO{sub 2} addition to the synthesis gas and cesium doping of the catalyst promoted methanol synthesis, while inhibiting the synthesis of dimethyl ether. Injection of water, however, was found to slightly suppress methanol and dimethyl ether formation while being converted to CO{sub 2} via the water gas shift reaction over these catalysts. There was no clear correlation between copper surface area and catalyst activity. Surface analysis of the tested samples revealed that copper tended to migrate and enrich the catalyst surface. The concept of employing a double-bed reactor with a pronounced temperature gradient to enhance higher alcohol synthesis was explored, and it was found that utilization of a Cs-promoted Cu/ZnO/Cr{sub 2}O{sub 3} catalyst as a first lower temperature bed and a Cs-promoted ZnO/Cr{sub 2}O{sub 3} catalyst as a second high-temperature bed significantly promoted the productivity of 2-methyl-1-propanol (isobutanol) from H{sub 2}/CO synthesis gas mixtures. While the conversion of CO to C{sub 2+} oxygenates over the double-bed configuration was comparable to that observed over the single Cu-based catalyst, major changes in the product distribution occurred by the coupling to the zinc chromite catalyst; that is, the productivity of the C{sub 1}-C{sub 3} alcohols decreased dramatically, and 2-methyl branched alcohols were selectively formed. The desirable methanol/2-methyl oxygenate molar ratios close to 1 were obtained in the present double

  14. The Production of Biodiesel from Cottonseed Oil Using Rhizopus oryzae Whole Cell Biocatalysts

    NASA Astrophysics Data System (ADS)

    Athalye, Sneha Kishor

    accumulation of 15.6 g (dry cell wt)/L. A reduction in dynamic viscosity of the reaction mixture from 47.3 centipoise to 30.6 centipoise was observed. The impact of moisture addition to the reaction mixture and use of ethanol as acylating agent on R.oryzae BSP fatty acid alkyl ester production was also tested. The presence of 10 wt % moisture in the reaction system had a significant effect (p ≤ 0.05) on the transesterification reaction with ethanol unlike methanol. Fatty acid ethyl ester concentration tripled from 39.3 to 129.1 g/L when moisture was added during transesterification .When oil to acyl acceptor ratio was increased from 1:3 and 1:6 to determine effect of excess alcohol on conversion, an ester conversion of 128.1 g/L for methanol and 129.1 g/L for ethanol were observed. Use of excess amount of acylating agent had a significant adverse effect (p ≤ 0.05) on the overall FAAE production due to deactivation of lipases on contact with large amounts of insoluble alcohol in the oil phase of the reaction. The effect of short chain alcohols on the enzymatic transesterification of cottonseed oil using freeze dried Rhizopus oryzae biomass was examined with and without water addition using methanol, ethanol, 1-Propanol and 1-Butanol at various molar ratios. 1- Butanol in the absence of water resulted in a significantly higher (p . 0.1) conversion of cottonseed oil to 12.5 % fatty acid butyl esters (FABEs). Addition of 10 % water to the reaction mixture significantly reduced (p ≤ 0.1) conversion. No significant difference (p > 0.1) between the conversions was observed for time points after 24 h for a 72 h reaction. 1- Butanol in ratios higher than 3:1 to cottonseed oil had a significant impact (p ≤ 0.1) on conversion. Increasing the amount of biomass used during the reaction lead to significantly higher conversion (p ≤ 0.1). The highest conversion of 27.9 % was observed for the transesterification reaction between cottonseed oil and 1-Butanol, in a 1:6 molar ratio, in

  15. Oxy-combustion of high water content fuels

    NASA Astrophysics Data System (ADS)

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the

  16. The Production of Biodiesel from Cottonseed Oil Using Rhizopus oryzae Whole Cell Biocatalysts

    NASA Astrophysics Data System (ADS)

    Athalye, Sneha Kishor

    accumulation of 15.6 g (dry cell wt)/L. A reduction in dynamic viscosity of the reaction mixture from 47.3 centipoise to 30.6 centipoise was observed. The impact of moisture addition to the reaction mixture and use of ethanol as acylating agent on R.oryzae BSP fatty acid alkyl ester production was also tested. The presence of 10 wt % moisture in the reaction system had a significant effect (p ≤ 0.05) on the transesterification reaction with ethanol unlike methanol. Fatty acid ethyl ester concentration tripled from 39.3 to 129.1 g/L when moisture was added during transesterification .When oil to acyl acceptor ratio was increased from 1:3 and 1:6 to determine effect of excess alcohol on conversion, an ester conversion of 128.1 g/L for methanol and 129.1 g/L for ethanol were observed. Use of excess amount of acylating agent had a significant adverse effect (p ≤ 0.05) on the overall FAAE production due to deactivation of lipases on contact with large amounts of insoluble alcohol in the oil phase of the reaction. The effect of short chain alcohols on the enzymatic transesterification of cottonseed oil using freeze dried Rhizopus oryzae biomass was examined with and without water addition using methanol, ethanol, 1-Propanol and 1-Butanol at various molar ratios. 1- Butanol in the absence of water resulted in a significantly higher (p . 0.1) conversion of cottonseed oil to 12.5 % fatty acid butyl esters (FABEs). Addition of 10 % water to the reaction mixture significantly reduced (p ≤ 0.1) conversion. No significant difference (p > 0.1) between the conversions was observed for time points after 24 h for a 72 h reaction. 1- Butanol in ratios higher than 3:1 to cottonseed oil had a significant impact (p ≤ 0.1) on conversion. Increasing the amount of biomass used during the reaction lead to significantly higher conversion (p ≤ 0.1). The highest conversion of 27.9 % was observed for the transesterification reaction between cottonseed oil and 1-Butanol, in a 1:6 molar ratio, in

  17. NTP Toxicology and Carcinogenesis Studies of Glycidol (CAS No. 556-52-5) In F344/N Rats and B6C3F1 Mice (Gavage Studies).

    PubMed

    1990-03-01

    mice administered glycidol by intraperitoneal injection. Conclusions: Under the conditions of these 2-year gavage studies, there was clear evidence of carcinogenic activity of glycidol for male F344/N rats, based on increased incidences of mesotheliomas of the tunica vaginalis; fibroadenomas of the mammary gland; gliomas of the brain; and neoplasms of the forestomach, intestine, skin, Zymbal gland, and thyroid gland. There was clear evidence of carcinogenic activity for female F344/N rats, based on increased incidences of fibroadenomas and adenocarcinomas of the mammary gland; gliomas of the brain; neoplasms of the oral mucosa, forestomach, clitoral gland, and thyroid gland; and leukemia. There was clear evidence of carcinogenic activity for male B6C3F1 mice based on increased incidences of neoplasms of the harderian gland, forestomach, skin, liver, and lung. There was clear evidence of carcinogenic activity for female B6C3F1 mice, based on increased incidences of neoplasms of the harderian gland, mammary gland, uterus, subcutaneous tissue, and skin. Other neoplasms that may have been related to the administration of glycidol were fibrosarcomas of the glandular stomach in female rats and carcinomas of the urinary bladder and sarcomas of the epididymis in male mice. Synonym: 2,3-epoxy-1-propanol

  18. Oxy-combustion of high water content fuels

    NASA Astrophysics Data System (ADS)

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the