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Sample records for acid composition based

  1. Deoxyribonucleic acid base compositions of dermatophytes.

    PubMed

    Davison, F D; Mackenzie, D W; Owen, R J

    1980-06-01

    DNA was extracted and purified from 55 dermatophyte isolates representing 34 species of Trichophyton, Microsporum and Epidermophyton. The base compositions of the chromosomal DNA were determined by CsCl density gradient centrifugation and were found to be in the narrow range of 48.7 to 50.3 mol % G + C. A satellite DNA component assumed to be of mitochondrial origin was present in most strains, with a G + C content ranging from 14.7 to 30.8 mol % G + C. Heterogeneity in microscopic and colonial characteristics was not reflected in differences in the mean G + C content of the chromosomal DNAs. Strains varied in the G + C contents of satelite DNA, but these did not correlate with traditional species concepts.

  2. Thermal and Mechanical Characteristics of Polymer Composites Based on Epoxy Resin, Aluminium Nanopowders and Boric Acid

    NASA Astrophysics Data System (ADS)

    Nazarenko, O. B.; Melnikova, T. V.; Visakh, P. M.

    2016-01-01

    The epoxy polymers are characterized by low thermal stability and high flammability. Nanoparticles are considered to be effective fillers of polymer composites for improving their thermal and functional properties. In this work, the epoxy composites were prepared using epoxy resin ED-20, polyethylene polyamine as a hardener, aluminum nanopowder and boric acid fine powder as flame-retardant filler. The thermal characteristics of the obtained samples were studied using thermogravimetric analysis and differential scanning calorimetry. The mechanical characteristics of epoxy composites were also studied. It was found that an addition of all fillers enhances the thermal stability and mechanical characteristics of the epoxy composites. The best thermal stability showed the epoxy composite filled with boric acid. The highest flexural properties showed the epoxy composite based on the combination of boric acid and aluminum nanopowder.

  3. Carbon composite micro- and nano-tubes-based electrodes for detection of nucleic acids

    PubMed Central

    2011-01-01

    The first aim of this study was to fabricate vertically aligned multiwalled carbon nanotubes (MWCNTs). MWCNTs were successfully prepared by using plasma enhanced chemical vapour deposition. Further, three carbon composite electrodes with different content of carbon particles with various shapes and sizes were prepared and tested on measuring of nucleic acids. The dependences of adenine peak height on the concentration of nucleic acid sample were measured. Carbon composite electrode prepared from a mixture of glassy and spherical carbon powder and MWCNTs had the highest sensitivity to nucleic acids. Other interesting result is the fact that we were able to distinguish signals for all bases using this electrode. PMID:21711910

  4. Influence of a peracetic acid-based immersion on indirect composite resin.

    PubMed

    Samuel, Susana Maria Werner; Fracaro, Gisele Baggio; Collares, Fabrício Mezzomo; Leitune, Vicente Castelo Branco; Campregher, Ulisses Bastos

    2011-06-01

    The aim of this study was to evaluate the influence of immersion in a 0.2% peracetic acid-based disinfectant on the three-point flexural strength, water sorption and water solubility of an indirect composite resin. Specimens were produced according to ISO 4049:2000 specifications and were divided in two groups: Control group, with no disinfection and Disinfected group, with three 10 min immersions in the peracetic acid intercalated with 10 min immersions in sterile distilled water. All evaluations were conducted in compliance with ISO specifications. Three-point flexural strength, water sorption and solubility of indirect composite resin before and after immersion showed no statistical significant differences (p > 0.05) and met ISO standard requirements. Immersion in peracetic acid solution showed no influence in indirect composite resin tested properties.

  5. Food composition and acid-base balance: alimentary alkali depletion and acid load in herbivores.

    PubMed

    Kiwull-Schöne, Heidrun; Kiwull, Peter; Manz, Friedrich; Kalhoff, Hermann

    2008-02-01

    Alkali-enriched diets are recommended for humans to diminish the net acid load of their usual diet. In contrast, herbivores have to deal with a high dietary alkali impact on acid-base balance. Here we explore the role of nutritional alkali in experimentally induced chronic metabolic acidosis. Data were collected from healthy male adult rabbits kept in metabolism cages to obtain 24-h urine and arterial blood samples. Randomized groups consumed rabbit diets ad libitum, providing sufficient energy but variable alkali load. One subgroup (n = 10) received high-alkali food and approximately 15 mEq/kg ammonium chloride (NH4Cl) with its drinking water for 5 d. Another group (n = 14) was fed low-alkali food for 5 d and given approximately 4 mEq/kg NH4Cl daily for the last 2 d. The wide range of alimentary acid-base load was significantly reflected by renal base excretion, but normal acid-base conditions were maintained in the arterial blood. In rabbits fed a high-alkali diet, the excreted alkaline urine (pH(u) > 8.0) typically contained a large amount of precipitated carbonate, whereas in rabbits fed a low-alkali diet, both pH(u) and precipitate decreased considerably. During high-alkali feeding, application of NH4Cl likewise decreased pH(u), but arterial pH was still maintained with no indication of metabolic acidosis. During low-alkali feeding, a comparably small amount of added NH4Cl further lowered pH(u) and was accompanied by a significant systemic metabolic acidosis. We conclude that exhausted renal base-saving function by dietary alkali depletion is a prerequisite for growing susceptibility to NH4Cl-induced chronic metabolic acidosis in the herbivore rabbit.

  6. Development of palm-based reference materials for the quantification of fatty acids composition.

    PubMed

    Tarmizi, Azmil Haizam Ahmad; Lin, Siew Wai; Kuntom, Ainie

    2008-01-01

    Characterisation of fatty acids composition of three palm-based reference materials was carried out through inter-laboratory proficiency tests. Twelve laboratories collaborated in these tests and the fatty acids compositions of palm oil, palm olein and palm stearin were determined by applying the MPOB Test Methods p3.4:2004 and p3.5:2004. Determination of consensus values and their uncertainties were based on the acceptable statistical agreement of results obtained from the collaborating laboratories. The consensus values and uncertainties (%) for each palm oil reference material produced are listed as follows : 0.20% (C12:0), 1.66+/-0.05% (C14:0), 43.39+/-0.39% (C16:0), 0.14+/-0.06% (C16:1), 3.90+/-0.11% (C18:0), 40.95+/-0.23% (C18:1), 9.68+/-0.21% (C18:2), 0.16+/-0.07% (C18:3) and 0.31+/-0.08% (C20:0) for fatty acids composition of palm oil; 0.23+/-0.04% (C12:0), 1.02+/-0.04% (C14:0), 39.66+/-0.19% (C16:0), 0.18+/-0.07% (C16:1), 3.81+/-0.04% (C18:0), 44.01+/-0.08% (C18:1), 10.73+/-0.08% (C18:2), 0.20+/-0.06% (C18:3) and 0.34+/-0.04% (C20:0) for fatty acids composition of palm olein; and 0.20% (C12:0), 1.14+/-0.05% (C14:0), 49.42+/-0.25% (C16:0), 0.16+/-0.08% (C16:1), 4.15+/-0.10% (C18:0), 36.14+/-0.77% (C18:1), 7.95+/-0.29% (C18:2), 0.11+/-0.07% (C18:3) and 0.30+/-0.08% (C20:0) for fatty acids composition of palm stearin.

  7. Morphology and properties of hybrid composites based on polypropylene/polylactic acid blend and bamboo fiber.

    PubMed

    Ying-Chen, Zhang; Hong-Yan, Wu; Yi-Ping, Qiu

    2010-10-01

    The design of new composites based on a polypropylene (PP)/polylactic acid (PLA) matrix and filler bamboo fiber (BF) leads to changes in process ability, morphology, and rheological properties of the raw thermoplastic. We have designed more environmentally friendly composites blended with PLA, filled with bamboo fiber. To refine dispersion of PLA and improve composite toughness, MAH-g-PP was included in the filler-matrix interface to enhance interface strength for PP, PLA and BF. The incorporation of MAH-g-PP into composites brought about beneficial changes in morphology and rheological, related with improved dispersion of PLA and increased bamboo fiber-matrix interactions. The SEM results showed the particle size of the dispersed PLA and BF phase significantly reduced with adding a litter MAH-g-PP. The XRD and DSC results showed that spread and phases in the composites preserved crystallization. The good rheological, morphological and thermal properties obtained when the ratio of PP/PLA/BF/MAH-g-PP was 48.75/13/35/3.25.

  8. Agreement Between Deoxyribonucleic Acid Base Composition and Taxometric Classification of Gram-Positive Cocci1

    PubMed Central

    Silvestri, L. G.; Hill, L. R.

    1965-01-01

    Silvestri, L. G. (Università Statale, Milan, Italy), and L. R. Hill. Agreement between deoxyribonucleic acid base composition and taxometric classification of gram-positive cocci. J. Bacteriol. 90:136–140. 1965.—It had been previously proposed, from taxometric analyses, that gram-positive, catalase-positive cocci be divided into two subgroups. Thirteen strains, representative of both subgroups, were examined for deoxyribonucleic acid (DNA) base composition, determined from melting temperatures. Per cent GC (guanine + cytosine/total bases) values fell into two groups: 30.8 to 36.5% GC and 69 to 75% GC. Strains with low per cent GC values belonged to the Staphylococcus aureus–S. saprophyticus–S. lactis taxometric subgroups, and those with high per cent GC values belonged to the S. roseus–S. afermentans subgroup. The hypothetical nature of any classification is emphasized, and, in the present work, the hypothesis derived from taxometric analyses of division into two subgroups is confirmed by the study of DNA base ratios. The two subgroups correspond, respectively, to the genera Staphylococcus and Micrococcus. PMID:16562008

  9. Influence of the composition of monoacyl phosphatidylcholine based microemulsions on the dermal delivery of flufenamic acid.

    PubMed

    Hoppel, Magdalena; Ettl, Hanna; Holper, Evelyn; Valenta, Claudia

    2014-11-20

    Although microemulsions are one of the most promising dermal carrier systems, their clinical use is limited due to their skin irritation potential. Therefore, microemulsions based on naturally derived monoacyl phosphatidylcholine (MAPL) were developed. The influence of the water, oil and surfactant content on dermal delivery of flufenamic acid was systematically investigated for the first time. A water-rich microemulsion led to significantly higher in vitro skin penetration of flufenamic acid compared to other microemulsions. The superiority of the water-rich microemulsion over a marketed flufenamic acid containing formulation was additionally confirmed. Differences in drug delivery could be explained by alterations of the microemulsions after application. Evaporation of isopropanol led to crystal-like structures of MAPL on the skin surface from the surfactant- or oleic acid-rich microemulsions. In contrast, the formation of this additional barrier was hindered in case of the water-rich microemulsion. The skin penetration of MAPL was additionally analyzed by combined ATR-FTIR and tape stripping experiments, where MAPL itself penetrated only into the initial layers of the stratum corneum, independent of the microemulsion composition. Since a surfactant must penetrate the skin to cause irritation, MAPL can be presumed as a skin-friendly emulsifier with the ability to stabilize pharmaceutically acceptable microemulsions.

  10. 3D composites based on the blends of chitosan and collagen with the addition of hyaluronic acid.

    PubMed

    Sionkowska, Alina; Kaczmarek, Beata; Lewandowska, Katarzyna; Grabska, Sylwia; Pokrywczyńska, Marta; Kloskowski, Tomasz; Drewa, Tomasz

    2016-08-01

    3D porous composites based on blends of chitosan, collagen and hyaluronic acid were obtained through the lyophilization process. Mechanical properties, swelling behavior and thermal stability of the blends were studied. Moreover, SEM images were taken and the structure of the blends was studied. Biological properties of the materials obtained were investigated by analyzing of proliferation rate of fibroblast cells incubated with biomaterial extract using MTT assay (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide). The results showed that the properties of 3D composites based on the blends of chitosan and collagen were altered after the addition 1%, 2% and 5% of hyaluronic acid. Mechanical properties and thermal stability of chitosan/collagen blends were improved in the presence of hyaluronic acid in the composite. New 3D materials based on the blends of chitosan, collagen and hyaluronic acid were non-toxic and did not significantly affect cell morphology.

  11. BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA.

    PubMed

    SIGAL, N; SENEZ, J C; LEGALL, J; SEBALD, M

    1963-06-01

    Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315-1318. 1963-The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c(3) and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin ("nigrificans" and "orientis") are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively.

  12. Novel ammonia sensor based on polyaniline/polylactic acid composite films

    NASA Astrophysics Data System (ADS)

    Sotirov, S.; Bodurov, I.; Marudova, M.

    2017-01-01

    We propose a new type of ammonia sensor based on composite film between polyaniline (emeraldine base) dissolved in dimethylformamide, and poly(DL-lactic) acid dissolved in chloroform. The two solutions were mixed in weight ratio of the components 1:1 and cast on Al2O3 substrate, on which silver electrodes were deposited previously. The active layer structure and morphology were examined by atomic force microscopy. The sensor resistance at constant humidity and different ammonia concentrations was measured. It was found that an increase in the ammonia concentration leads to resistance increase. This result is explained in the terms of ionic interactions between the polyaniline and the ammonia, which change the permittivity of the sensor active media. A response between 2% and 590% was shown depending on the ammonia concentration. The sensor is reversible and possesses response time of typically 100 s. Based on the changes of the sensor resistance, ammonia concentration from 10 ppm to 1000 ppm could be detected.

  13. Composition of exchangeable bases and acidity in soils of the Crimean Mountains

    NASA Astrophysics Data System (ADS)

    Kostenko, I. V.

    2015-08-01

    Acid forest and mountainous meadow soils of the Crimean Mountains were studied. The amount of hydrogen and aluminum ions extracted from these soils depended on the pH of extracting agents. The maximum values of the soil acidity were obtained upon the extraction with a strongly alkaline solution of sodium acetate in 0.05 N NaOH. The application of this extractant made it possible to determine the total exchange acidity, the total amount of extractable aluminum, and the total cation exchange capacity of the soils after the extraction of all the acidic components from them. The values of these characteristics were significantly higher than the values of the potential acidity and cation exchange capacity obtained by the routine analytical methods. Hydrogen predominated among the acidic components of the exchange acidity in the humus horizons, whereas aluminum predominated among them in the underlying mineral horizons. Hydrothermic conditions and the character of vegetation and parent materials were the major factors affecting the relationships between bases and acidic components in the soil adsorption complex.

  14. Insight into acid-base nucleation experiments by comparison of the chemical composition of positive, negative, and neutral clusters.

    PubMed

    Bianchi, Federico; Praplan, Arnaud P; Sarnela, Nina; Dommen, Josef; Kürten, Andreas; Ortega, Ismael K; Schobesberger, Siegfried; Junninen, Heikki; Simon, Mario; Tröstl, Jasmin; Jokinen, Tuija; Sipilä, Mikko; Adamov, Alexey; Amorim, Antonio; Almeida, Joao; Breitenlechner, Martin; Duplissy, Jonathan; Ehrhart, Sebastian; Flagan, Richard C; Franchin, Alessandro; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Kangasluoma, Juha; Keskinen, Helmi; Kim, Jaeseok; Kirkby, Jasper; Laaksonen, Ari; Lawler, Michael J; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Mathot, Serge; Onnela, Antti; Petäjä, Tuukka; Riccobono, Francesco; Rissanen, Matti P; Rondo, Linda; Tomé, António; Virtanen, Annele; Viisanen, Yrjö; Williamson, Christina; Wimmer, Daniela; Winkler, Paul M; Ye, Penglin; Curtius, Joachim; Kulmala, Markku; Worsnop, Douglas R; Donahue, Neil M; Baltensperger, Urs

    2014-12-02

    We investigated the nucleation of sulfuric acid together with two bases (ammonia and dimethylamine), at the CLOUD chamber at CERN. The chemical composition of positive, negative, and neutral clusters was studied using three Atmospheric Pressure interface-Time Of Flight (APi-TOF) mass spectrometers: two were operated in positive and negative mode to detect the chamber ions, while the third was equipped with a nitrate ion chemical ionization source allowing detection of neutral clusters. Taking into account the possible fragmentation that can happen during the charging of the ions or within the first stage of the mass spectrometer, the cluster formation proceeded via essentially one-to-one acid-base addition for all of the clusters, independent of the type of the base. For the positive clusters, the charge is carried by one excess protonated base, while for the negative clusters it is carried by a deprotonated acid; the same is true for the neutral clusters after these have been ionized. During the experiments involving sulfuric acid and dimethylamine, it was possible to study the appearance time for all the clusters (positive, negative, and neutral). It appeared that, after the formation of the clusters containing three molecules of sulfuric acid, the clusters grow at a similar speed, independent of their charge. The growth rate is then probably limited by the arrival rate of sulfuric acid or cluster-cluster collision.

  15. Chemical composition and acid-base properties of the surface of GaAs-CdS solid solutions

    NASA Astrophysics Data System (ADS)

    Kirovskaya, I. A.; Zemtsov, A. E.

    2007-01-01

    Chemical composition and acid-base properties of the surfaces of GaAs-CdS solid solutions and the constituent binary compounds exposed to air, vacuum, CO, and NH3 were analyzed using mass spectrometry, IR spectrometry, isoelectric-point pH (pHiso) analysis, and mechanochemical methods. Powders and films were prepared from the solid solutions by isothermal diffusion and discrete vacuum evaporation, respectively. XRD and Raman analysis revealed that a solid solution has a sphalerite or wurtzite structure, depending on its composition. The initial surface of all the systems studied exhibited acidic properties: the pH value ranged from 4.9 to 6.45. The surfaces contained Lewis (electron accepting) and Brönsted (adsorbed H2O and CO2 molecules, OH- groups) sites. The acidity of the surface increased upon treatment with CO and decreased upon treatment with NH3. For all types of treatment, the concentration dependence of the acid-base properties of the surface exhibited an extremum. The strongest acidic sites were revealed on the surface of the (GaAs)0.95 (CdS)0.05 solid solution. The adsorption activity of this solution, a promising material for manufacturing gas sensors, was evaluated.

  16. Water Absorption of Jute/Polylactic Acid Composite Intended for an Interior Application and Comparison with Wood-Based Panels

    NASA Astrophysics Data System (ADS)

    Zandvliet, C.; Bandyopadhyay, N. R.; Ray, D.

    2014-04-01

    Jute/polylactic acid (PLA) composite is of special interest because it is entirely from renewable resources with high mechanical properties. Thus, it could be a more eco-friendly alternative to the conventional wood-based panels made of formaldehyde resin which is asserted to be carcinogenic. Yet the water affinity of the natural fibres and susceptibility of polylactic acid towards hydrolysis raise a question about the water resistance of such composites in service condition. In this work, the water absorption behaviour of jute/PLA composites, jute/maleated polypropylene was investigated with regard to interior applications following the standard test method in accordance to ISO 16983:2003 `Wood-based panels—determination of swelling in thickness after immersion in water' and compared to standard of wood-based panels. Untreated and treated jute/PLA composites exhibited a superior water resistance property compared to particleboard, MDF and hardboard and they are by far, below the minimum requirement of the ISO standard 16983.

  17. Biodegradable poly-lactic acid based-composite reinforced unidirectionally with high-strength magnesium alloy wires.

    PubMed

    Li, X; Chu, C L; Liu, L; Liu, X K; Bai, J; Guo, C; Xue, F; Lin, P H; Chu, Paul K

    2015-05-01

    Biodegradable poly-lactic acid (PLA)--based composites reinforced unidirectionally with high-strength magnesium alloy wires (MAWs) are fabricated by a heat-compressing process and the mechanical properties and degradation behavior are studied experimentally and theoretically. The composites possess improved strengthening and toughening properties. The bending strength and impact strength of the composites with 40 vol% MAWs are 190 MPa and 150 kJ/m(2), respectively, although PLA has a low viscosity and an average molecular weight of 60,000 g/mol. The mechanical properties of the composites can be further improved by internal structure modification and interface strengthening and a numerical model incorporating the equivalent section method (ESM) is proposed for the bending strength. Micro arc oxidization (MAO) of the MAWs is an effective interfacial strengthening method. The composites exhibit high strength retention during degradation and the PLA in the composite shows a smaller degradation rate than pure PLA. The novel biodegradable composites have large potential in bone fracture fixation under load-bearing conditions.

  18. Deoxyribonucleic acid base composition and taxonomy of Moniliella and allied genera.

    PubMed

    de Hoog, G S; Guého, E

    1984-01-01

    DNA base compositions of representative (type) strains of Moniliella, Trichosporonoides and Hyalodendron were determined. Within Trichosporonoides over 16% variance was found. Most species separated well, but M. suaveolens showed considerable heterogeneity. The standard 2% G + C differences for species distinction is probably not applicable to these yeasts. The new combination M. pollinis is proposed for M. tomentosa var. pollinis on the basis of slight ecological, morphological and physiological differences, supported by a marked difference in % G + C.

  19. Nucleic acid detection compositions

    DOEpatents

    Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James L.

    2008-08-05

    The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.

  20. Synthesis and characterization of new composite materials based on poly(methacrylic acid) and hydroxyapatite with applications in dentistry.

    PubMed

    Cucuruz, Andrei Tiberiu; Andronescu, Ecaterina; Ficai, Anton; Ilie, Andreia; Iordache, Florin

    2016-08-30

    The use of methacrylic acid (MAA) in medicine was poorly investigated in the past but can be of great importance because the incorporation of hydroxyapatite (HA) can lead to new composite materials with good properties due to the strong electrostatic interactions between carboxylate groups of polymer and Ca(2+) ions from HA. The scope of this study was to determine the potential of using composite materials based on poly(methacrylic acid) (PMAA) and hydroxyapatite in dentistry. Two routes of synthesis were taken into account: i) HA was synthesised in situ and ii) commercial HA was used. Fourier transform infrared spectroscopy and X-ray diffraction were used for compositional assessments. Scanning electron microscopy was performed to determine the morphology and differential thermal analysis (DTA) coupled with thermogravimetric analysis (TG) was used to study the thermal behaviour and to observe quantitative changes. In-vitro tests were also performed in order to evaluate the biocompatibility of both PMAA/HA composites by monitoring the development potential of human endothelial cells using MTT assay and fluorescent microscopy.

  1. Structural and dynamical studies of acid-mediated conversion in amorphous-calcium-phosphate based dental composites

    SciTech Connect

    Zhang, Fan; Allen, Andrew J.; Levine, Lyle E.; Vaudin, Mark D.; Skrtic, Drago; Antonucci, Joseph M.; Hoffman, Kathleen M.; Giuseppetti, Anthony A.; Ilavsky, Jan

    2014-07-28

    Our objective was to investigate the complex structural and dynamical conversion process of the amorphous-calcium-phosphate (ACP)-to-apatite transition in ACP based dental composite materials. Composite disks were prepared using zirconia hybridized ACP fillers (0.4 mass fraction) and photo-activated Bis-GMA/TEGDMA resin (0.6 mass fraction). We performed an investigation of the solution-mediated ACP-to-apatite conversion mechanism in controlled acidic aqueous environment with in situ ultra-small angle X-ray scattering based coherent X-ray photon correlation spectroscopy and ex situ X-ray diffraction, as well as other complementary techniques. We established that the ACP-to-apatite conversion in ACP composites is a two-step process, owing to the sensitivity to local structural changes provided by coherent X-rays. Initially, ACP undergoes a local microstructural rearrangement without losing its amorphous character. We established the catalytic role of the acid and found the time scale of this rearrangement strongly depends on the pH of the solution, which agrees with previous findings about ACP without the polymer matrix being present. In the second step, ACP is converted to an apatitic form with the crystallinity of the formed crystallites being poor. Separately, we also confirmed that in the regular Zr-modified ACP the rate of ACP conversion to hydroxyapatite is slowed significantly compared to unmodified ACP, which is beneficial for targeted slow release of functional calcium and phosphate ions from dental composite materials. Significantly, for the first time, we were able to follow the complete solution-mediated transition process from ACP to apatite in this class of dental composites in a controlled aqueous environment. A two-step process, suggested previously, was conclusively identified.

  2. Structural and dynamical studies of acid-mediated conversion in amorphous-calcium-phosphate based dental composites

    DOE PAGES

    Zhang, Fan; Allen, Andrew J.; Levine, Lyle E.; ...

    2014-07-28

    Our objective was to investigate the complex structural and dynamical conversion process of the amorphous-calcium-phosphate (ACP)-to-apatite transition in ACP based dental composite materials. Composite disks were prepared using zirconia hybridized ACP fillers (0.4 mass fraction) and photo-activated Bis-GMA/TEGDMA resin (0.6 mass fraction). We performed an investigation of the solution-mediated ACP-to-apatite conversion mechanism in controlled acidic aqueous environment with in situ ultra-small angle X-ray scattering based coherent X-ray photon correlation spectroscopy and ex situ X-ray diffraction, as well as other complementary techniques. We established that the ACP-to-apatite conversion in ACP composites is a two-step process, owing to the sensitivity to localmore » structural changes provided by coherent X-rays. Initially, ACP undergoes a local microstructural rearrangement without losing its amorphous character. We established the catalytic role of the acid and found the time scale of this rearrangement strongly depends on the pH of the solution, which agrees with previous findings about ACP without the polymer matrix being present. In the second step, ACP is converted to an apatitic form with the crystallinity of the formed crystallites being poor. Separately, we also confirmed that in the regular Zr-modified ACP the rate of ACP conversion to hydroxyapatite is slowed significantly compared to unmodified ACP, which is beneficial for targeted slow release of functional calcium and phosphate ions from dental composite materials. Significantly, for the first time, we were able to follow the complete solution-mediated transition process from ACP to apatite in this class of dental composites in a controlled aqueous environment. A two-step process, suggested previously, was conclusively identified.« less

  3. An optical sensor based on H-acid/layered double hydroxide composite film for the selective detection of mercury ion.

    PubMed

    Sun, Zhiyong; Jin, Lan; Zhang, Shitong; Shi, Wenying; Pu, Min; Wei, Min; Evans, David G; Duan, Xue

    2011-09-19

    A novel optical chemosensor was fabricated based on 1-amino-8-naphthol-3,6-disulfonic acid sodium (H-acid) intercalated layered double hydroxide (LDH) film via the electrophoretic deposition (EPD) method. The film of H-acid/LDH with the thickness of 1 μm possesses a well c-orientation of the LDH microcrystals confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The fluorescence detection for Hg(II) in aqueous solution was performed by using the H-acid/LDH film sensor at pH 7.0, with a linear response range in 1.0 × 10(-7) to 1.0 × 10(-5) mol L(-1) and a detection limit of 6.3 × 10(-8) mol L(-1). Furthermore, it exhibits excellent selectivity for Hg(II) over a large number of competitive cations including alkali, alkaline earth, heavy metal and transitional metals. The specific fluorescence response of the optical sensor is attributed to the coordination between Hg(II) and sulfonic group in the H-acid immobilized in the LDH matrix, which was verified by NMR spectroscopy and UV-vis spectra. In addition, density functional theory (DFT) calculation further confirms that the coordination occurs between one Hg(2+) and two O atoms in the sulfonic group, which is responsible for the significant fluorescence quenching of the H-acid/LDH film. The results indicate that the H-acid/LDH composite film can be potentially used as a chemosensor for the detection of Hg(2+) in the environmental and biomedical field.

  4. Prediction of bulk milk fatty acid composition based on farming practices collected through on-farm surveys.

    PubMed

    Coppa, M; Ferlay, A; Chassaing, C; Agabriel, C; Glasser, F; Chilliard, Y; Borreani, G; Barcarolo, R; Baars, T; Kusche, D; Harstad, O M; Verbič, J; Golecký, J; Martin, B

    2013-07-01

    The aim of this study was to predict the fatty acid (FA) composition of bulk milk using data describing farming practices collected via on-farm surveys. The FA composition of 1,248 bulk cow milk samples and the related farming practices were collected from 20 experiments led in 10 different European countries at 44°N to 60°N latitude and sea level to 2,000 m altitude. Farming practice-based FA predictions [coefficient of determination (R(2)) >0.50] were good for C16:0, C17:0, saturated FA, polyunsaturated FA, and odd-chain FA, and very good (R(2) ≥0.60) for trans-11 C18:1, trans-10 + trans-11 C18:1, cis-9,trans-11 conjugated linoleic acid, total trans FA, C18:3n-3, n-6:n-3 ratio, and branched-chain FA. Fatty acids were predicted by cow diet composition and by the altitude at which milk was produced, whereas animal-related factors (i.e., lactation stage, breed, milk yield, and proportion of primiparous cows in the herd) were not significant in any of the models. Proportion of fresh herbage in the cow diet was the main predictor, with the highest effect in almost all FA models. However, models built solely on conserved forage-derived samples gave good predictions for odd-chain FA, branched-chain FA, trans-10 C18:1 and C18:3n-3 (R(2) ≥0.46, 0.54, 0.52, and 0.70, respectively). These prediction models could offer farmers a valuable tool to help improve the nutritional quality of the milk they produce.

  5. Fatty acid composition at the base of aquatic food webs is influenced by habitat type and watershed land use

    USGS Publications Warehouse

    Larson, James H.; Richardson, William B.; Knights, Brent C.; Bartsch, Lynn; Bartsch, Michelle; Nelson, J. C.; Veldboom, Jason A.; Vallazza, Jonathan M.

    2013-01-01

    Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary systems of Lake Michigan, USA. FA composition of food is important because all metazoans require certain FAs for proper growth and development that cannot be produced de novo, including many polyunsaturated fatty acids (PUFAs). Here we sampled three habitat types (river, rivermouth and nearshore zone) in 11 tributaries of Lake Michigan to assess the amount of FA in seston and primary consumers of seston. We hypothesize that among-system and among-habitat variation in FAs at the base of food webs would be related to algal production, which in turn is influenced by three land cover characteristics: 1) combined agriculture and urban lands (an indication of anthropogenic nutrient inputs that fuel algal production), 2) the proportion of surface waters (an indication of water residence times that allow algal producers to accumulate) and 3) the extent of riparian forested buffers (an indication of stream shading that reduces algal production). Of these three land cover characteristics, only intense land use appeared to strongly related to seston and consumer FA and this effect was only strong in rivermouth and nearshore lake sites. River seston and consumer FA composition was highly variable, but that variation does not appear to be driven by the watershed land cover characteristics investigated here. Whether the spatial variation in FA content at the base of these food webs significantly influences the production of economically important species higher in the food web should be a focus of future research.

  6. Fatty Acid Composition at the Base of Aquatic Food Webs Is Influenced by Habitat Type and Watershed Land Use

    PubMed Central

    Larson, James H.; Richardson, William B.; Knights, Brent C.; Bartsch, Lynn A.; Bartsch, Michelle R.; Nelson, John C.; Veldboom, Jason A.; Vallazza, Jon M.

    2013-01-01

    Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary systems of Lake Michigan, USA. FA composition of food is important because all metazoans require certain FAs for proper growth and development that cannot be produced de novo, including many polyunsaturated fatty acids (PUFAs). Here we sampled three habitat types (river, rivermouth and nearshore zone) in 11 tributaries of Lake Michigan to assess the amount of FA in seston and primary consumers of seston. We hypothesize that among-system and among-habitat variation in FAs at the base of food webs would be related to algal production, which in turn is influenced by three land cover characteristics: 1) combined agriculture and urban lands (an indication of anthropogenic nutrient inputs that fuel algal production), 2) the proportion of surface waters (an indication of water residence times that allow algal producers to accumulate) and 3) the extent of riparian forested buffers (an indication of stream shading that reduces algal production). Of these three land cover characteristics, only intense land use appeared to strongly related to seston and consumer FA and this effect was only strong in rivermouth and nearshore lake sites. River seston and consumer FA composition was highly variable, but that variation does not appear to be driven by the watershed land cover characteristics investigated here. Whether the spatial variation in FA content at the base of these food webs significantly influences the production of economically important species higher in the food web should be a focus of future research. PMID:23940619

  7. Retention of nucleic acids in ion-pair reversed-phase high-performance liquid chromatography depends not only on base composition but also on base sequence.

    PubMed

    Qiao, Jun-Qin; Liang, Chao; Wei, Lan-Chun; Cao, Zhao-Ming; Lian, Hong-Zhen

    2016-12-01

    The study on nucleic acid retention in ion-pair reversed-phase high-performance liquid chromatography mainly focuses on size-dependence, however, other factors influencing retention behaviors have not been comprehensively clarified up to date. In this present work, the retention behaviors of oligonucleotides and double-stranded DNAs were investigated on silica-based C18 stationary phase by ion-pair reversed-phase high-performance liquid chromatography. It is found that the retention of oligonucleotides was influenced by base composition and base sequence as well as size, and oligonucleotides prone to self-dimerization have weaker retention than those not prone to self-dimerization but with the same base composition. However, homo-oligonucleotides are suitable for the size-dependent separation as a special case of oligonucleotides. For double-stranded DNAs, the retention is also influenced by base composition and base sequence, as well as size. This may be attributed to the interaction of exposed bases in major or minor grooves with the hydrophobic alky chains of stationary phase. In addition, no specific influence of guanine and cytosine content was confirmed on retention of double-stranded DNAs. Notably, the space effect resulted from the stereostructure of nucleic acids also influences the retention behavior in ion-pair reversed-phase high-performance liquid chromatography.

  8. Composition for nucleic acid sequencing

    DOEpatents

    Korlach, Jonas; Webb, Watt W.; Levene, Michael; Turner, Stephen; Craighead, Harold G.; Foquet, Mathieu

    2008-08-26

    The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is followed in real time. The sequence is deduced by identifying which base is being incorporated into the growing complementary strand of the target nucleic acid by the catalytic activity of the nucleic acid polymerizing enzyme at each step in the sequence of base additions. A polymerase on the target nucleic acid molecule complex is provided in a position suitable to move along the target nucleic acid molecule and extend the oligonucleotide primer at an active site. A plurality of labelled types of nucleotide analogs are provided proximate to the active site, with each distinguishable type of nucleotide analog being complementary to a different nucleotide in the target nucleic acid sequence. The growing nucleic acid strand is extended by using the polymerase to add a nucleotide analog to the nucleic acid strand at the active site, where the nucleotide analog being added is complementary to the nucleotide of the target nucleic acid at the active site. The nucleotide analog added to the oligonucleotide primer as a result of the polymerizing step is identified. The steps of providing labelled nucleotide analogs, polymerizing the growing nucleic acid strand, and identifying the added nucleotide analog are repeated so that the nucleic acid strand is further extended and the sequence of the target nucleic acid is determined.

  9. Effect of Acid-Base Property of Inorganic Nanoparticles on Antifouling Performance of PVDF Composite Ultrafiltration Membranes

    NASA Astrophysics Data System (ADS)

    He, Mingjia; Shi, Baoli

    Pure poly(vinylidene fluoride) (PVDF) membrane and PVDF composite membranes modified by three kinds of inorganic nanoparticles (SiO2, Al2O3, and TiO2) were made using a phase inversion method and characterized by pure water flux, retention efficiency of Bovine serum albumin (BSA), flux reduction coefficient, and scanning electron microscope (SEM). The results of flux reduction coefficient illustrated that PVDF membrane modified by nanoparticles had better antifouling property in the order of TiO2, Al2O3, SiO2. The Lewis acid-base properties of the nanoparticle materials were measured by inverse gas chromatography (IGC). The Lewis acid number, Ka, and Lewis base number, Kb, had the following order Ka TiO2 < Ka Al2O3 < Ka SiO2, and Kb TiO2 > Kb Al2O3 > Kb SiO2. The experimental results indicated that PVDF membrane modified by nanoparticles with relatively strong base exhibited excellent antifouling performance.

  10. Mechanical Behavior and Thermal Stability of Acid-Base Phosphate Cements and Composites Fabricated at Ambient Temperature

    NASA Astrophysics Data System (ADS)

    Colorado Lopera, Henry Alonso

    This dissertation presents the study of the mechanical behavior and thermal stability of acid-base phosphate cements (PCs) and composites fabricated at ambient temperature. These materials are also known as chemically bonded phosphate ceramics (CBPCs). Among other advantages of using PCs when compared with traditional cements are the better mechanical properties (compressive and flexural strength), lower density, ultra-fast (controllable) setting time, controllable pH, and an environmentally benign process. Several PCs based on wollastonite and calcium and alumino phosphates after thermal exposure up to 1000°C have been investigated. First, the thermo-mechanical and chemical stability of wollastonite-based PC (Wo-PC) exposed to temperatures up to 1000°C in air environment were studied. The effects of processing conditions on the curing and shrinkage of the wollastonite-based PC were studied. The chemical reactions and phase transformations during the fabrication and during the thermal exposure are analyzed in detail using scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermo-gravimetric analysis (TGA Then, the thermo-mechanical and chemical stability of glass, carbon and basalt fiber reinforced Wo-PC composites, were studied using SEM, XRD, TGA. The flexural strength and Weibull statistics were analyzed. A significant strength degradation in the composites were found after the thermal exposure at elevated temperatures due to the interdifusion and chemical reactions across the fibers and the matrix at temperatures over 600°C. To overcome this barrier, we have developed a new PC based on calcium and alumino-phosphates (Ca-Al PCs). The Ca-Al PCs were studied in detail using SEM, XRD, TGA, curing, shrinkage, Weibull statistics, and compression tests. Our study has confirmed that this new composite material is chemically and mechanically stable at temperatures up to 1000°C. Moreover, the compression strength increases after exposure to 1000

  11. Harnessing Computational Biology for Exact Linear B-Cell Epitope Prediction: A Novel Amino Acid Composition-Based Feature Descriptor.

    PubMed

    Saravanan, Vijayakumar; Gautham, Namasivayam

    2015-10-01

    Proteins embody epitopes that serve as their antigenic determinants. Epitopes occupy a central place in integrative biology, not to mention as targets for novel vaccine, pharmaceutical, and systems diagnostics development. The presence of T-cell and B-cell epitopes has been extensively studied due to their potential in synthetic vaccine design. However, reliable prediction of linear B-cell epitope remains a formidable challenge. Earlier studies have reported discrepancy in amino acid composition between the epitopes and non-epitopes. Hence, this study proposed and developed a novel amino acid composition-based feature descriptor, Dipeptide Deviation from Expected Mean (DDE), to distinguish the linear B-cell epitopes from non-epitopes effectively. In this study, for the first time, only exact linear B-cell epitopes and non-epitopes have been utilized for developing the prediction method, unlike the use of epitope-containing regions in earlier reports. To evaluate the performance of the DDE feature vector, models have been developed with two widely used machine-learning techniques Support Vector Machine and AdaBoost-Random Forest. Five-fold cross-validation performance of the proposed method with error-free dataset and dataset from other studies achieved an overall accuracy between nearly 61% and 73%, with balance between sensitivity and specificity metrics. Performance of the DDE feature vector was better (with accuracy difference of about 2% to 12%), in comparison to other amino acid-derived features on different datasets. This study reflects the efficiency of the DDE feature vector in enhancing the linear B-cell epitope prediction performance, compared to other feature representations. The proposed method is made as a stand-alone tool available freely for researchers, particularly for those interested in vaccine design and novel molecular target development for systems therapeutics and diagnostics: https://github.com/brsaran/LBEEP.

  12. Effect of compatibilization on the properties of in situ microfibrillar composites based on polylactic acid and polypropylene

    NASA Astrophysics Data System (ADS)

    Oliviero, Maria; Buonocore, Giovanna G.; Verdolotti, Letizia; Lavorgna, Marino

    2015-12-01

    The aim of this work was to explore the feasibility of using polypropylene (PP) as an reinforcing material for polylactide acid (PLA) based on the concept of in situ microfibrillar composites (iMFCs). Microfibers of PP were successfully generated by melt mixing, slit die extrusion and cold stretching. However, due to their immiscibility feature, the interfacial interaction between PP microfibers and PLA matrix is poor. In order to reduce the interfacial tension of the blend, PP-grafted with maleic anhydride was used as an interfacial compatibilizer. The effect of filler content on morphological appearance, mechanical and water vapor barrier properties were investigated. Results show the effect of the compatibilizer to stabilize the morphology developed during compounding and to enhance adhesion between the phases thus improving the properties of the obtained iMFCs.

  13. Oil base drilling fluid composition

    SciTech Connect

    Patel, A.D.; Salandanan, C.

    1988-04-26

    This patent describes an improved oil-base drilling fluid composition characterized by thixotropic properties resulting in a yield point of from about 10 to about 75 comprising an oil-base continuous phase and a gelling composition. The gelling composition includes a latex material copolymerized with one or more functional monomers selected from the group consisting of: amides, amines, sulfonates, monocarboxylic acids, dicarboxylic acids and combinations thereof and wherein at least one of the one or more functional monomers is an amide selected from the group consisting of: acrylamide, N-methylolacrylamide, N-alkyl-acrylamide, vinylacetamide, vinylpyrrolidone, N-vinyl-N-methylacetamide, vinylformamide and combinations thereof.

  14. Development of Novel Biodegradable Amino Acid Ester Based Polyphosphazene-Hydroxyapatite Composites for Bone Tissue Engineering

    DTIC Science & Technology

    2005-01-01

    dicalcium phosphate dehydrate cement [5, 6]. Biodegradable polymers are attractive candidates for developing composites for transient applications...TetCP, with a calcium to phosphate ratio of 2.0 and dicalcium phosphate anhydrous were reacted in varying molar ratios to obtain two different calcium...laurencin@virginia.edu ASTRACT Hydroxyapatite formed from low temperature setting calcium phosphate cements (CPC) are currently been used for

  15. Biological and mechanical evaluation of poly(lactic-co-glycolic acid) based composites reinforced with one, two and three dimensional carbon biomaterials for bone tissue regeneration.

    PubMed

    Kaur, Tejinder; Kulanthaivel, Senthilguru; Arunachalam, Thirugnanam; Banerjee, Indranil; Pramanik, Krishna

    2017-02-09

    Considering the fact that life on earth is carbon based, carbon materials are being introduced in biological systems. However, very limited information is existing concerning the potential effects of different structures of carbon materials on biological systems. In the present study, poly(lactic-co-glycolic acid) (PLGA) based carbonaceous composites were developed by reinforcing 1 wt% of three different carbon based materials i.e. carbon nanotubes (CNTs-one dimensional), graphene nanoplatelets (GNPs-two dimensional) and activated carbon (AC-three dimensional). The developed composites were characterized for physicochemical, biological and mechanical properties. Along with their hemocompatible nature, the composites exhibited better swelling ratio, degradation percentage, bioactivity and tensile strength. The improvement in hydrophilicity and protein adsorption resulted in enhancement of cell proliferation and differentiation. Amongst all, sheet like GNPs showed strongest effect on composite's properties due to its larger area exposed. These results demonstrate the potential of PLGA based carbonaceous composites for accelerating bone tissue regeneration.

  16. Effect of phosphate-based glass fibre surface properties on thermally produced poly(lactic acid) matrix composites.

    PubMed

    Mohammadi, Maziar Shah; Ahmed, Ifty; Muja, Naser; Rudd, Christopher D; Bureau, Martin N; Nazhat, Showan N

    2011-12-01

    Incorporation of soluble bioactive glass fibres into biodegradable polymers is an interesting approach for bone repair and regeneration. However, the glass composition and its surface properties significantly affect the nature of the fibre-matrix interface and composite properties. Herein, the effect of Si and Fe on the surface properties of calcium containing phosphate based glasses (PGs) in the system (50P(2)O(5)-40CaO-(10-x)SiO(2)-xFe(2)O(3), where x = 0, 5 and 10 mol.%) were investigated. Contact angle measurements revealed a higher surface energy, and surface polarity as well as increased hydrophilicity for Si doped PG which may account for the presence of surface hydroxyl groups. Two PG formulations, 50P(2)O(5)-40CaO-10Fe(2)O(3) (Fe10) and 50P(2)O(5)-40CaO-5Fe(2)O(3)-5SiO(2) (Fe5Si5), were melt drawn into fibres and randomly incorporated into poly(lactic acid) (PLA) produced by melt processing. The ageing in deionised water (DW), mechanical property changes in phosphate buffered saline (PBS) and cytocompatibility properties of these composites were investigated. In contrast to Fe10 and as a consequence of the higher surface energy and polarity of Fe5Si5, its incorporation into PLA led to increased inorganic/organic interaction indicated by a reduction in the carbonyl group of the matrix. PLA chain scission was confirmed by a greater reduction in its molecular weight in PLA-Fe5Si5 composites. In DW, the dissolution rate of PLA-Fe5Si5 was significantly higher than that of PLA-Fe10. Dissolution of the glass fibres resulted in the formation of channels within the matrix. Initial flexural strength was significantly increased through PGF incorporation. After PBS ageing, the reduction in mechanical properties was greater for PLA-Fe5Si5 compared to PLA-Fe10. MC3T3-E1 preosteoblasts seeded onto PG discs, PLA and PLA-PGF composites were evaluated for up to 7 days indicating that the materials were generally cytocompatible. In addition, cell alignment along the PGF

  17. Deoxyribonucleic acid base composition and biochemical properties of certain coagulase-negative enterotoxigenic cocci.

    PubMed

    Lotter, L P; Genigeorgis, C A

    1975-02-01

    Eight coagulase-negative, enterotoxigenic strains of cocci and one weakly coagulase-positive strain isolated from a number of different sources, including cases of food poisoning incidents, were evaluated for their relationship to Staphylococcus aureus on the basis of deoxyribonucleic acid (DNA) buoyant density and physiological studies. One strain of cocci produced enterotoxins A and C, two strains produced types B and C, four strains produced only type C, and one strain only type D. The enterotoxin produced by one strain of cocci was serologically untypable. None of the test organisms produced detectable amounts of enterotoxin in broth cultures. The test strains of cocci exhibited the following profile: all produced catalase; all grew anaerobically and fermented glucse; five were sensitive to lysostaphin; the percentage of guanine plus cytosine content of their DNA varied from 32.7 to 37.6; five produced acid from mannitol both aerobically and anaerobically; two formed delta-hemolysin; five produced phosphatase and acetoin; and all produced heat-stable nuclease. None of the organisms exhibited typical characteristics of S. aureus, S. epidermidis, or S. saprophyticus. On the basis of the present data and data reported elsewhere, these organisms should be considered as variants or mutants of S. aureus.

  18. TMB-Hunt: An amino acid composition based method to screen proteomes for beta-barrel transmembrane proteins

    PubMed Central

    Garrow, Andrew G; Agnew, Alison; Westhead, David R

    2005-01-01

    Background Beta-barrel transmembrane (bbtm) proteins are a functionally important and diverse group of proteins expressed in the outer membranes of bacteria (both gram negative and acid fast gram positive), mitochondria and chloroplasts. Despite recent publications describing reasonable levels of accuracy for discriminating between bbtm proteins and other proteins, screening of entire genomes remains troublesome as these molecules only constitute a small fraction of the sequences screened. Therefore, novel methods are still required capable of detecting new families of bbtm protein in diverse genomes. Results We present TMB-Hunt, a program that uses a k-Nearest Neighbour (k-NN) algorithm to discriminate between bbtm and non-bbtm proteins on the basis of their amino acid composition. By including differentially weighted amino acids, evolutionary information and by calibrating the scoring, an accuracy of 92.5% was achieved, with 91% sensitivity and 93.8% positive predictive value (PPV), using a rigorous cross-validation procedure. A major advantage of this approach is that because it does not rely on beta-strand detection, it does not require resolved structures and thus larger, more representative, training sets could be used. It is therefore believed that this approach will be invaluable in complementing other, physicochemical and homology based methods. This was demonstrated by the correct reassignment of a number of proteins which other predictors failed to classify. We have used the algorithm to screen several genomes and have discussed our findings. Conclusion TMB-Hunt achieves a prediction accuracy level better than other approaches published to date. Results were significantly enhanced by use of evolutionary information and a system for calibrating k-NN scoring. Because the program uses a distinct approach to that of other discriminators and thus suffers different liabilities, we believe it will make a significant contribution to the development of a

  19. Incremental effect of a calcium salt of cis-monounsaturated fatty acids supplement on milk fatty acid composition in cows fed maize silage-based diets.

    PubMed

    Kliem, K E; Reynolds, C K; Humphries, D J; Kirkland, R M; Barratt, C E S; Livingstone, K M; Givens, D I

    2013-05-01

    In most Western countries, saturated fatty acid (SFA) intake exceeds recommended levels, which is considered a risk factor for cardiovascular disease (CVD). As milk and dairy products are major contributors to SFA intake in many countries, recent research has focused on sustainable methods of producing milk with a lower saturated fat concentration by altering dairy cow diets. Human intervention studies have shown that CVD risk can be reduced by consuming dairy products with reduced SFA and increased cis-monounsaturated fatty acid (MUFA) concentrations. This milk fatty acid profile can be achieved by supplementing dairy cow diets with cis-MUFA-rich unsaturated oils. However, rumen exposure of unsaturated oils also leads to enhanced milk trans fatty acid (TFA) concentrations. Because of concerns about the effects of TFA consumption on CVD, feeding strategies that increase MUFA concentrations in milk without concomitant increases in TFA concentration are preferred by milk processors. In an attempt to limit TFA production and increase the replacement of SFA by cis-MUFA, a preparation of rumen-protected unsaturated oils was developed using saponification with calcium salts. Four multiparous Holstein-Friesian cows in mid-late lactation were used in a 4 × 4 Latin square design with 21-d periods to investigate the effect of incremental dietary inclusion of a calcium salt of cis-MUFA product (Ca-MUFA; 20, 40, and 60 g/kg of dry matter of a maize silage-based diet), on milk production, composition, and fatty acid concentration. Increasing Ca-MUFA inclusion reduced dry matter intake linearly, but no change was observed in estimated ME intake. No change in milk yield was noted, but milk fat and protein concentrations were linearly reduced. Supplementation with Ca-MUFA resulted in a linear reduction in total SFA (from 71 to 52 g/100 g of fatty acids for control and 60 g/kg of dry matter diets, respectively). In addition, concentrations of both cis- and trans-MUFA were

  20. Computational Identification of Protein Pupylation Sites by Using Profile-Based Composition of k-Spaced Amino Acid Pairs.

    PubMed

    Hasan, Md Mehedi; Zhou, Yuan; Lu, Xiaotian; Li, Jinyan; Song, Jiangning; Zhang, Ziding

    2015-01-01

    Prokaryotic proteins are regulated by pupylation, a type of post-translational modification that contributes to cellular function in bacterial organisms. In pupylation process, the prokaryotic ubiquitin-like protein (Pup) tagging is functionally analogous to ubiquitination in order to tag target proteins for proteasomal degradation. To date, several experimental methods have been developed to identify pupylated proteins and their pupylation sites, but these experimental methods are generally laborious and costly. Therefore, computational methods that can accurately predict potential pupylation sites based on protein sequence information are highly desirable. In this paper, a novel predictor termed as pbPUP has been developed for accurate prediction of pupylation sites. In particular, a sophisticated sequence encoding scheme [i.e. the profile-based composition of k-spaced amino acid pairs (pbCKSAAP)] is used to represent the sequence patterns and evolutionary information of the sequence fragments surrounding pupylation sites. Then, a Support Vector Machine (SVM) classifier is trained using the pbCKSAAP encoding scheme. The final pbPUP predictor achieves an AUC value of 0.849 in 10-fold cross-validation tests and outperforms other existing predictors on a comprehensive independent test dataset. The proposed method is anticipated to be a helpful computational resource for the prediction of pupylation sites. The web server and curated datasets in this study are freely available at http://protein.cau.edu.cn/pbPUP/.

  1. Well acidizing compositions and method

    SciTech Connect

    Gardener, T.R.; Dill, W.R.; Ford, W.G.F.; King, K.L.

    1991-07-23

    This patent describes a concentrate which forms an acid internal microemulsion well treatment composition when added to an acid treatment fluid. It comprises in the range of from about 20% to about 98% by weight of a hydrocarbon carrier fluid; in the range of from about 1% to about 50% by weight of an alkyl alcohol having in the range of from about 4 to 18 carbon atoms; and in the range of from about 1% to about 50% by weight of an emulsifying agent comprising at least one compound selected from the group consisting of amine salts having ester or amide linkages and propoxylated alcohols, each of the components being different compounds or different mixtures of compounds.

  2. DNA binding protein identification by combining pseudo amino acid composition and profile-based protein representation

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Wang, Shanyi; Wang, Xiaolong

    2015-10-01

    DNA-binding proteins play an important role in most cellular processes. Therefore, it is necessary to develop an efficient predictor for identifying DNA-binding proteins only based on the sequence information of proteins. The bottleneck for constructing a useful predictor is to find suitable features capturing the characteristics of DNA binding proteins. We applied PseAAC to DNA binding protein identification, and PseAAC was further improved by incorporating the evolutionary information by using profile-based protein representation. Finally, Combined with Support Vector Machines (SVMs), a predictor called iDNAPro-PseAAC was proposed. Experimental results on an updated benchmark dataset showed that iDNAPro-PseAAC outperformed some state-of-the-art approaches, and it can achieve stable performance on an independent dataset. By using an ensemble learning approach to incorporate more negative samples (non-DNA binding proteins) in the training process, the performance of iDNAPro-PseAAC was further improved. The web server of iDNAPro-PseAAC is available at http://bioinformatics.hitsz.edu.cn/iDNAPro-PseAAC/.

  3. Preparation and characterization of composites based on poly(lactic acid) and CaCO{sub 3} nanofiller

    SciTech Connect

    Moreno, Janaína Fernandes; Silva, Ana Lúcia N. da E-mail: ananazareth@ima.ufrj.br; Sousa, Ana Maria F. de

    2015-05-22

    In recent years, extensive studies have been conducted on the study of the poly(lactic acid) (PLA) properties, because of its being a typical biobased and biodegradable polymer, with good mechanical properties. However, its toughness and gas barrier properties are not satisfactory and can be improved by the addition of nanofillers, such as calcium carbonate (n-CaCO{sub 3}). The present work PLA composites with nano-sized precipitated calcium carbonate (n-NPCC) were prepared by melt extrusion. Thermal, mechanical and flow properties of the composites were evaluated by using a factorial design.The results showed that the addition of the nanofiller in the PLA matrix didn’t improve thethermal and mechanical properties of the matrix significantly. This behavior is probably due to the presence of the stearic acid that is coating on the n-NPCC particles, resulting in a weak polymer-particle interaction. Beyond this, it was also observed a decrease in MFI of the composites when nanofiller was added and at a higher screw speed.

  4. Preparation and characterization of composites based on poly(lactic acid) and CaCO3 nanofiller

    NASA Astrophysics Data System (ADS)

    Moreno, Janaína Fernandes; da Silva, Ana Lúcia N.; da Silva, Antonio Henrique Monteiro da Fonseca T.; de Sousa, Ana Maria F.

    2015-05-01

    In recent years, extensive studies have been conducted on the study of the poly(lactic acid) (PLA) properties, because of its being a typical biobased and biodegradable polymer, with good mechanical properties. However, its toughness and gas barrier properties are not satisfactory and can be improved by the addition of nanofillers, such as calcium carbonate (n-CaCO3). The present work PLA composites with nano-sized precipitated calcium carbonate (n-NPCC) were prepared by melt extrusion. Thermal, mechanical and flow properties of the composites were evaluated by using a factorial design.The results showed that the addition of the nanofiller in the PLA matrix didn't improve thethermal and mechanical properties of the matrix significantly. This behavior is probably due to the presence of the stearic acid that is coating on the n-NPCC particles, resulting in a weak polymer-particle interaction. Beyond this, it was also observed a decrease in MFI of the composites when nanofiller was added and at a higher screw speed.

  5. Fatty acid composition of selected prosthecate bacteria.

    PubMed

    Carter, R N; Schmidt, J M

    1976-10-11

    The cellular fatty acid composition of 14 strains of Caulobacter speices and types, two species of Prosthecomicrobium, and two species of Asticcacaulis was determined by gas-liquid chromatography. In most of these bacteria, the major fatty acids were octadecenoic acid (C18:1), hexadecenoic acid (C16:1) and hexadecanoic acid (C16:0). Some cyclopropane and branched chain fatty acids were detected in addition to the straight chained acids. Hydroxytetradecanoic acid was an important component of P.enhydrum but significant amounts of hydroxy acids were not detected in other prosthecate bacteria examined.

  6. Enteric methane production, rumen volatile fatty acid concentrations, and milk fatty acid composition in lactating Holstein-Friesian cows fed grass silage- or corn silage-based diets.

    PubMed

    van Gastelen, S; Antunes-Fernandes, E C; Hettinga, K A; Klop, G; Alferink, S J J; Hendriks, W H; Dijkstra, J

    2015-03-01

    The objective of this study was to determine the effects of replacing grass silage (GS) with corn silage (CS) in dairy cow diets on enteric methane (CH4) production, rumen volatile fatty acid concentrations, and milk fatty acid (FA) composition. A completely randomized block design experiment was conducted with 32 multiparous lactating Holstein-Friesian cows. Four dietary treatments were used, all having a roughage-to-concentrate ratio of 80:20 based on dry matter (DM). The roughage consisted of either 100% GS, 67% GS and 33% CS, 33% GS and 67% CS, or 100% CS (all DM basis). Feed intake was restricted (95% of ad libitum DM intake) to avoid confounding effects of DM intake on CH4 production. Nutrient intake, apparent digestibility, milk production and composition, nitrogen (N) and energy balance, and CH4 production were measured during a 5-d period in climate respiration chambers after adaptation to the diet for 12 d. Increasing CS proportion linearly decreased neutral detergent fiber and crude protein intake and linearly increased starch intake. Milk production and milk fat content (on average 23.4 kg/d and 4.68%, respectively) were not affected by increasing CS inclusion, whereas milk protein content increased quadratically. Rumen variables were unaffected by increasing CS inclusion, except the molar proportion of butyrate, which increased linearly. Methane production (expressed as grams per day, grams per kilogram of fat- and protein-corrected milk, and as a percent of gross energy intake) decreased quadratically with increasing CS inclusion, and decreased linearly when expressed as grams of CH4 per kilogram of DM intake. In comparison with 100% GS, CH4 production was 11 and 8% reduced for the 100% CS diet when expressed per unit of DM intake and per unit fat- and protein-corrected milk, respectively. Nitrogen efficiency increased linearly with increased inclusion of CS. The concentration of trans C18:1 FA, C18:1 cis-12, and total CLA increased quadratically, and

  7. Compositions for acid treating subterranean formations

    SciTech Connect

    Clark, E. Jr.; Swanson, B.L.

    1991-03-05

    This patent describes a high viscosity acid composition. It comprises: an aqueous acid solution; one or more acrylamide polymers dissolved in the acid solution in an amount sufficient to increase the viscosity of the acid solution; a liquid hydrocarbon dispersed in the acid solution; and one or more nonionic surface active agents having at least one reactive hydroxyl group per molecule present in the composition in an amount sufficient to interact with the acrylamide polymer or polymers in the presence of the liquid hydrocarbon whereby the viscosity of the acid solution is further increased and stabilized.

  8. Effect of feeding palm oil by-products based diets on muscle fatty acid composition in goats.

    PubMed

    Abubakr, Abdelrahim; Alimon, Abdul Razak; Yaakub, Halimatun; Abdullah, Norhani; Ivan, Michael

    2015-01-01

    The present study aims to evaluate the effects of feeding palm oil by-products based diets on different muscle fatty acid profiles in goats. Thirty-two Cacang × Boer goats were randomly assigned to four dietary treatments: (1) control diet (CD), (2) 80% decanter cake diet (DCD), (3) 80% palm kernel cake diet (PKCD) and (4) CD plus 5% palm oil (PO) supplemented diet (CPOD). After 100 days of feeding, four goats from each group were slaughtered and longissimus dorsi (LD), infraspinatus (IS) and biceps femoris (BF) were sampled for analysis of fatty acids. Goats fed the PKCD had higher (P<0.05) concentration of lauric acid (C12:0) than those fed the other diets in all the muscles tested. Compared to the other diets, the concentrations of palmitic acid (C16:0) and stearic acid (C18:0) were lower (P<0.05) and that of linoleic acid (C18:2 n-6) was higher (P<0.05) in the muscles from goats fed the CD. It was concluded that palm kernel cake and decanter cake can be included in the diet of goats up to 80% with more beneficial than detrimental effects on the fatty acid profile of their meat.

  9. Effect of Feeding Palm Oil By-Products Based Diets on Muscle Fatty Acid Composition in Goats

    PubMed Central

    Abubakr, Abdelrahim; Alimon, Abdul Razak; Yaakub, Halimatun; Abdullah, Norhani; Ivan, Michael

    2015-01-01

    The present study aims to evaluate the effects of feeding palm oil by-products based diets on different muscle fatty acid profiles in goats. Thirty-two Cacang × Boer goats were randomly assigned to four dietary treatments: (1) control diet (CD), (2) 80% decanter cake diet (DCD), (3) 80% palm kernel cake diet (PKCD) and (4) CD plus 5% palm oil (PO) supplemented diet (CPOD). After 100 days of feeding, four goats from each group were slaughtered and longissimus dorsi (LD), infraspinatus (IS) and biceps femoris (BF) were sampled for analysis of fatty acids. Goats fed the PKCD had higher (P<0.05) concentration of lauric acid (C12:0) than those fed the other diets in all the muscles tested. Compared to the other diets, the concentrations of palmitic acid (C16:0) and stearic acid (C18:0) were lower (P<0.05) and that of linoleic acid (C18:2 n-6) was higher (P<0.05) in the muscles from goats fed the CD. It was concluded that palm kernel cake and decanter cake can be included in the diet of goats up to 80% with more beneficial than detrimental effects on the fatty acid profile of their meat. PMID:25789610

  10. Production of a composite hyaluronic acid/gelatin blood plasma gel for hydrogel-based adipose tissue engineering applications.

    PubMed

    Korurer, Esra; Kenar, Halime; Doger, Emek; Karaoz, Erdal

    2014-07-01

    Standard approaches to soft-tissue reconstruction include autologous adipose tissue transplantation, but most of the transferred adipose tissue is generally reabsorbed in a short time. To overcome this problem, long lasting implantable hydrogel materials that can support tissue regeneration must be produced. The purpose of this study was to evaluate the suitability of composite 3D natural origin scaffolds for reconstructive surgery applications through in vitro tests. The Young's modulus of the glutaraldehyde crosslinked hyaluronic acid/gelatin (HA/G) plasma gels, composed of human platelet-poor plasma, gelatin and human umbilical cord hyaluronic acid, was determined as 3.5 kPa, close to that of soft tissues. The composite HA/G plasma gels had higher porosity than plain plasma gels (72.5% vs. 63.86%). Human adipose tissue derived stem cells (AD-MSCs) were isolated from human lipoaspirates and characterized with flow cytometry, and osteogenic and adipogenic differentiation. Cell proliferation assay of AD-MSCs on the HA/G plasma gels revealed the nontoxic nature of these constructs. Adipogenic differentiation was distinctly better on HA/G plasma gels than on plain plasma gels. The results showed that the HA/G plasma gel with its suitable pore size, mechanical properties and excellent cell growth and adipogenesis supporting properties can serve as a useful scaffold for adipose tissue engineering applications.

  11. Effect of plant oils in the diet on performance and milk fatty acid composition in goats fed diets based on grass hay or maize silage.

    PubMed

    Bernard, Laurence; Shingfield, Kevin J; Rouel, Jacques; Ferlay, Anne; Chilliard, Yves

    2009-01-01

    Based on the potential benefits to long-term human health there is interest in developing sustainable nutritional strategies for reducing saturated and increasing specific unsaturated fatty acids in ruminant milk. The impact of plant oil supplements to diets containing different forages on caprine milk fatty acid composition was examined in two experiments using twenty-seven Alpine goats in replicated 3 x 3 Latin squares with 28 d experimental periods. Treatments comprised of no oil (control) or 130 g/d of sunflower-seed oil (SO) or linseed oil (LO) supplements added to diets based on grass hay (H; experiment 1) or maize silage (M; experiment 2). Milk fat content was enhanced (P<0.01) on HSO, HLO and MLO compared with the corresponding H or M control diets, resulting in 17, 15 and 14% increases in milk fat secretion, respectively. For both experiments, plant oils decreased (P<0.05) milk 10:0-16:0 and odd- and branched-chain fatty acid content and increased 18:0, trans-Delta(6-9,11-14,16)-18:1 (and their corresponding Delta-9 desaturase products), trans-7, trans-9-conjugated linoleic acid (CLA), trans-9, trans-11-CLA and trans-8, cis-10-CLA concentrations. Alterations in the distribution of cis-18:1, trans-18:1, -18:2 and CLA isomers in milk fat were related to plant oil composition and forage in the diet. In conclusion, plant oils represent an effective strategy for altering the fatty acid composition of caprine milk, with evidence that the basal diet is an important determinant of ruminal unsaturated fatty acid metabolism in the goat.

  12. Survey of the fatty acid composition of retail milk differing in label claims based on production management practices.

    PubMed

    O'Donnell, A M; Spatny, K P; Vicini, J L; Bauman, D E

    2010-05-01

    Consumers are becoming increasingly health conscious, and food product choices have expanded. Choices in the dairy case include fluid milk labeled according to production management practices. Such labeling practices may be misunderstood and perceived by consumers to reflect differences in the quality or nutritional content of milk. Our objective was to investigate nutritional differences in specialty labeled milk, specifically to compare the fatty acid (FA) composition of conventional milk with milk labeled as recombinant bST (rbST)-free or organic. The retail milk samples (n=292) obtained from the 48 contiguous states of the United States represented the consumer supply of pasteurized, homogenized milk of 3 milk types: conventionally produced milk with no specialty labeling, milk labeled rbST-free, and milk labeled organic. We found no statistical differences in the FA composition of conventional and rbST-free milk; however, these 2 groups were statistically different from organic milk for several FA. When measuring FA as a percentage of total FA, organic milk was higher in saturated FA (65.9 vs. 62.8%) and lower in monounsaturated FA (26.8 vs. 29.7%) and polyunsaturated FA (4.3 vs. 4.8%) compared with the average of conventional and rbST-free retail milk samples. Likewise, among bioactive FA compared as a percentage of total FA, organic milk was slightly lower in trans 18:1 FA (2.8 vs. 3.1%) and higher in n-3 FA (0.82 vs. 0.50%) and conjugated linoleic acid (0.70 vs. 0.57%). From a public health perspective, the direction for some of these differences would be considered desirable and for others would be considered undesirable; however, without exception, the magnitudes of the differences in milk FA composition among milk label types were minor and of no physiological importance when considering public health or dietary recommendations. Overall, when data from our analysis of FA composition of conventional milk and milk labeled rbST-free or organic were combined

  13. Starch composites with aconitic acid.

    PubMed

    Gilfillan, William Neil; Doherty, William O S

    2016-05-05

    The aim of this project is to examine the effectiveness of using aconitic acid (AcA), a tricarboxylic acid which contains a carbon/carbon double bond (CC), to enhance the properties of starch-based films. Starch/glycerol cast films were prepared with 0, 2, 5, 10 and 15wt% AcA (starch wt% basis) and the properties analysed. It was shown that AcA acted as both a cross-linking agent and also a strong plasticising agent. The 5wt% AcA derived starch films were the most effectively cross-linked having the lowest solubility (28wt%) and decreased swelling coefficient (35vol.%) by approximately 3 times and 2.4 times respectively compared to the control film submerged in water (23°C). There was also a significant increase in the film elongation at break by approximately 35 times (compared to the control) with the addition of 15wt% AcA, emphasising the plasticising effect of AcA. However, generally there was a reduced tensile strength, softening of the film, and reduced thermal stability with increased amounts of AcA.

  14. Physically Cross-linked Polymer Binder Induced by Reversible Acid-Base Interaction for High-Performance Silicon Composite Anodes.

    PubMed

    Lim, Sanghyun; Chu, Hodong; Lee, Kukjoo; Yim, Taeeun; Kim, Young-Jun; Mun, Junyoung; Kim, Tae-Hyun

    2015-10-28

    Silicon is greatly promising for high-capacity anode materials in lithium-ion batteries (LIBs) due to their exceptionally high theoretical capacity. However, it has a big challenge of severe volume changes during charge and discharge, resulting in substantial deterioration of the electrode and restricting its practical application. This conflict requires a novel binder system enabling reliable cyclability to hold silicon particles without severe disintegration of the electrode. Here, a physically cross-linked polymer binder induced by reversible acid-base interaction is reported for high performance silicon-anodes. Chemical cross-linking of polymer binders, mainly based on acidic polymers including poly(acrylic acid) (PAA), have been suggested as effective ways to accommodate the volume expansion of Si-based electrodes. Unlike the common chemical cross-linking, which causes a gradual and nonreversible fracturing of the cross-linked network, a physically cross-linked binder based on PAA-PBI (poly(benzimidazole)) efficiently holds the Si particles even after the large volume changes due to its ability to reversibly reconstruct ionic bonds. The PBI-containing binder, PAA-PBI-2, exhibited large capacity (1376.7 mAh g(-1)), high Coulombic efficiency (99.1%) and excellent cyclability (751.0 mAh g(-1) after 100 cycles). This simple yet efficient method is promising to solve the failures relating with pulverization and isolation from the severe volume changes of the Si electrode, and advance the realization of high-capacity LIBs.

  15. Graphene-based composites.

    PubMed

    Huang, Xiao; Qi, Xiaoying; Boey, Freddy; Zhang, Hua

    2012-01-21

    Graphene has attracted tremendous research interest in recent years, owing to its exceptional properties. The scaled-up and reliable production of graphene derivatives, such as graphene oxide (GO) and reduced graphene oxide (rGO), offers a wide range of possibilities to synthesize graphene-based functional materials for various applications. This critical review presents and discusses the current development of graphene-based composites. After introduction of the synthesis methods for graphene and its derivatives as well as their properties, we focus on the description of various methods to synthesize graphene-based composites, especially those with functional polymers and inorganic nanostructures. Particular emphasis is placed on strategies for the optimization of composite properties. Lastly, the advantages of graphene-based composites in applications such as the Li-ion batteries, supercapacitors, fuel cells, photovoltaic devices, photocatalysis, as well as Raman enhancement are described (279 references).

  16. PCL-gelatin composite nanofibers electrospun using diluted acetic acid-ethyl acetate solvent system for stem cell-based bone tissue engineering.

    PubMed

    Binulal, N S; Natarajan, Amrita; Menon, Deepthy; Bhaskaran, V K; Mony, Ullas; Nair, Shantikumar V

    2014-01-01

    Composite nanofibrous scaffolds with various poly(ε-caprolactone) (PCL)/gelatin ratios (90:10, 80:20, 70:30, 60:40, 50:50 wt.%) were successfully electrospun using diluted acetic and ethyl acetate mixture. The effects of this solvent system on the solution properties of the composites and its electrospinning properties were investigated. Viscosity and conductivity of the solutions, with the addition of gelatin, allowed for the electrospinning of uniform nanofibers with increasing hydrophilicity and degradation. Composite nanofibers containing 30 and 40 wt.% gelatin showed an optimum combination of hydrophilicity and degradability and also maintained the structural integrity of the scaffold. Human mesenchymal stem cells (hMSCs) showed favorable interaction with and proliferation on, the composite scaffolds. hMSC proliferation was highest in the 30 and 40 wt.% gelatin containing composites. Our experimental data suggested that PCL-gelatin composite nanofibers containing 30-40 wt.% of gelatin and electrospun in diluted acetic acid-ethyl acetate mixture produced nanofiber scaffolds with optimum hydrophilicity, degradability, and bio-functionality for stem cell-based bone tissue engineering.

  17. Designing novel macroporous composite hydrogels based on methacrylic acid copolymers and chitosan and in vitro assessment of lysozyme controlled delivery.

    PubMed

    Dragan, Ecaterina Stela; Cocarta, Ana Irina; Gierszewska, Magdalena

    2016-03-01

    Designing structure and morphology of macroporous hydrogels is crucial for their applications in controlled release systems of macromolecular drugs. Macroporous hydrogels, consisting of methacrylic acid (MAA) and either acryl amide (AAm) or 2-hydroxyethyl methacrylate (HEMA) (1st network), were prepared for this purpose by cryogelation (single network cryogels, SNCs). Macroporous interpenetrating polymer network (IPN) hydrogel composites were then prepared by a sequential strategy, the 2nd network consisting of chitosan (CS) cross-linked with poly(ethyleneglycol) diglycidyl ether (PEGDGE) being generated by the sorption of a CS and PEGDGE mixture in the 1st network followed by cross-linking. A strong difference in the behavior of SNCs and IPN hydrogel composites was found during the loading and release of lysozyme (LYS) used as macromolecular drug model. Thus, while the amount of LYS loaded on SNCs was higher than that loaded on the IPNs, the release of LYS from SNCs occurred at pH 2, when the ratio between MAA and AAm was 50:50, and only at pH 1 when the ratio between MAA and AAm was 70:30. The 2nd network led to the decrease of the pore size of the IPNs, mainly when the initial concentration of monomers was 10wt/v%, but the presence of CS facilitates the LYS release from IPNs, mainly at a concentration of monomer of 5wt/v%, and when HEMA was used as nonionic comonomer.

  18. Thermal properties of poly (lactic acid)/milkweed composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently, most polymer composites utilize petroleum-based materials that are non-degradable and difficult to recycle or incur substantial cost for disposal. Green composites can be used in nondurable limited applications. In order to determine the degree of compatibility between Poly (lactic Acid...

  19. Amino acid composition of some Mexican foods.

    PubMed

    Morales de León, Josefina; Camacho, M Elena; Bourges, Héctor

    2005-06-01

    Knowledge of the amino acid composition of foods is essential to calculate their chemical score, which is used to predict protein quality of foods and diets. Though amino acid composition of many foods is reasonably well established, better knowledge is needed on native foods consumed in different regions and countries. This paper presents the amino acid composition of different presentations of raw and processed foods produced and consumed in Mexico. The amino acid composition was determined using Beckman amino acid analyzers (models 116 and 6300). Tryptophan was determined using the Spies and Chambers method. Of the different foods analyzed, some comments are made on native or basic foods in Mexico: Spirulin, where lysine is the limiting amino acid, with a chemical score of 67%, is a good source of tryptophan (1.16g/16 gN); amaranth contains high levels of sulphur amino acids (4.09 to 5.34 g/16gN), with a protein content of 15 g/100g; and pulque, a Pre-Hispanic beverage that contains high levels of tryptophan (2.58 g/16 gN) and sulphur amino acids (2.72 g/16 gN). Finally, insects are good sources of sulphur amino acids and lysine.

  20. Hollow porous ionic liquids composite polymers based solid phase extraction coupled online with high performance liquid chromatography for selective analysis of hydrophilic hydroxybenzoic acids from complex samples.

    PubMed

    Dai, Xingping; Wang, Dongsheng; Li, Hui; Chen, Yanyi; Gong, Zhicheng; Xiang, Haiyan; Shi, Shuyun; Chen, Xiaoqing

    2017-02-10

    Polar and hydrophilic properties of hydroxybenzoic acids usually made them coelute with interferences in high performance liquid chromatography (HPLC) analysis. Then selective analysis of them was necessary. Herein, hollow porous ionic liquids composite polymers (PILs) based solid phase extraction (SPE) was firstly fabricated and coupled online with HPLC for selective analysis of hydroxybenzoic acids from complex matrices. Hollow porous PILs were firstly synthesized using Mobil Composition of Matter No. 48 (MCM-48) spheres as sacrificial support, 1-vinyl-3-methylimidazolium chloride (VMIM(+)Cl(-)) as monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker. Various parameters affecting synthesis, adsorption and desorption behaviors were investigated and optimized. Steady-state adsorption studies showed the resulting hollow porous PILs exhibited high adsorption capacity, fast adsorption kinetics, and excellent specific adsorption. Subsequently, the application of online SPE system was studied by selective analysis of protocatechuic acid (PCA), 4-hydroxybenzoic acid (4-HBA), and vanillic acid (VA) from Pollen Typha angustifolia. The obtained limit of detection (LOD) varied from 0.002 to 0.01μg/mL, the linear range (0.05-5.0μg/mL) was wide with correlation coefficient (R) from 0.9982 to 0.9994, and the average recoveries at three spiking levels ranged from 82.7 to 102.4%, with column-to-column relative standard deviation (RSD) below 8.1%. The proposed online method showed good accuracy, precision, specificity and convenience, which opened up a universal and efficient route for selective analysis of hydroxybenzoic acids from complex samples.

  1. A novel protein characterization based on Pseudo Amino Acids composition and Star-like graph topological indices.

    PubMed

    Dai, Qi; Tao, Hong; Ma, Tingting; Yao, Yuhua; He, Pingan

    2017-02-17

    In the work, a new description of proteins based on five topological indices of star-like graph representation and the occurrence frequency of 20 amino acids was proposed to compare the similarities of proteins. A phylogenetic tree of eight ND6 proteins was constructed to demonstrate the effectiveness and rationality of our approach. Analogously, we applied this method to RNA polymerase proteins of some subtypes of influenza virus to infer their phylogenetic relationship. The results showed that the phylogenetic relationship among RNA polymerase of influenza virus is closely related to distributions of species virus host and geographical distribution.

  2. Fullerene-C60-MWCNT composite film based ultrasensitive electrochemical sensing platform for the trace analysis of pyruvic acid in biological fluids.

    PubMed

    Brahman, Pradeep Kumar; Pandey, Nidhi; Topkaya, Seda Nur; Singhai, Rashmi

    2015-03-01

    We propose development of a novel electrochemical sensor based on fullerene-multi-walled carbon nanotubes composite film for the sensitive determination of the pyruvic acid in biological fluids. The developed sensor was characterized by cyclic voltammetry. The nanocomposite film of C60-MWCNTs on GCE exhibits electrocatalytic activity towards pyruvic acid reduction and also decreases the reduction overpotential. The influence of the optimization parameters such as pH and effect of loading of composite mixture of C60 and MWCNTs on the electrochemical performance of the sensor were evaluated. Various kinetic parameters such as electron transfer number (n=2), proton transfer number (m=2) and charge transfer coefficient (α=0.56) were also calculated. Under optimized conditions, the squarewave reduction peak current was linear over the concentration range of 2.0-55 nM with the detection and quantification limit of 0.1 nM and 0.8 nM respectively. The fabricated sensor was successfully applied to the detection of pyruvic acid in biological samples with good recovery ranging from 97.6% to 103.6%.

  3. Effects of different media and nitrogen sources and levels on growth and lipid of green microalga Botryococcus braunii KMITL and its biodiesel properties based on fatty acid composition.

    PubMed

    Ruangsomboon, Suneerat

    2015-09-01

    This work aimed to find an optimum culture medium for green microalga Botryococcus braunii KMITL and investigate its biodiesel properties based on fatty acid composition. Four different media were tested. Chlorella medium was the best medium for lipid yield. Among four nitrogen sources tested, KNO3 produced the highest lipid yield. When varied the nitrogen concentrations, this strain gave the highest lipid yield at the highest nitrogen level. When cultivated in the best medium and nitrogen source and level for 30 days, and then cultivated further for 14 days in the medium with no nitrogen, the highest lipid content and yield were 49.94±0.82% and 2.71±0.02 g L(-1), respectively. C16:0 fatty acid was the major fatty acid found. Fatty acid profiles of B. braunii KMITL cultivated in Chlorella medium with 1.25 g L(-1) KNO3 gave the best biodiesel properties with the lowest iodine value, maximum cetane number, and lowest degree of unsaturation.

  4. Compositions and method for controlling precipitation when acidizing sour wells

    SciTech Connect

    Dill, W.R.; Walker, M.L.

    1989-12-19

    This patent describes an acidizing composition for treating a sour well. It comprises: a base acid solution having an initial ph below 1.9; an iron sequestering agent to combine with iron present in the solution comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of the acids and ethers present in an amount of from about 0.25 to about 5 percent by weight of the acid solution; and a sulfide modifier to combine with sulfides present in the solution comprising at least one member selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming an aldehyde in solution, present in an amount of from about 1 to about 4 percent by weight of the acid solution, whereby precipitation of ferric hydroxide, ferrous sulfide and elemental sulfur is inhibited as acid spending occurs.

  5. Fatty acid composition of California grown almonds.

    PubMed

    Sathe, S K; Seeram, N P; Kshirsagar, H H; Heber, D; Lapsley, K A

    2008-11-01

    Eight almond (Prunus dulcis L.) cultivars from 12 different California counties, collected during crop years 2004 to 2005 and 2005 to 2006, were extracted with petroleum ether. The extracts were subjected to GC-MS analyses to determine fatty acid composition of soluble lipids. Results indicated palmitic (C16:0), oleic (C18:1), linoleic (C18:2), and alpha-linolenic (C18:3) acid, respectively, accounted for 5.07% to 6.78%, 57.54% to 73.94%, 19.32% to 35.18%, and 0.04% to 0.10%; of the total lipids. Oleic and linoleic acid were inversely correlated (r=-0.99, P= 0.05) and together accounted for 91.16% to 94.29% of the total soluble lipids. Statistically, fatty acid composition was significantly affected by cultivar and county.

  6. Effects of Biomass in Polyethylene or Polylactic Acid Composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown that compounding Polyethylene (PE) or Polylactic acid (PLA) with a dairy-based bioplastic resulted in composites with good mechanical properties. In this study, mass ratios of a dairy-protein-based material (DBP) ranging from 0, 5, 10 and 20 wt% replaced equivalent masse...

  7. Synthesis, characterization and fuel cell performance tests of boric acid and boron phosphate doped, sulphonated and phosphonated poly(vinyl alcohol) based composite membranes

    NASA Astrophysics Data System (ADS)

    Şahin, Alpay; Ar, İrfan

    2015-08-01

    The aim of this study is to synthesize a composite membrane having high proton conductivity, ion exchange capacity and chemical stability. In order to achieve this aim, poly(vinyl alcohol) (PVA) based composite membranes are synthesized by using classic sol-gel method. Boric acid (H3BO3) and boron phosphate (BPO4) are added to the membrane matrix in different ratios in order to enhance the membrane properties. Characterization tests, i.e; FT-IR analysis, mechanical strength tests, water hold-up capacities, swelling properties, ion exchange capacities, proton conductivities and fuel cell performance tests of synthesized membranes are carried out. As a result of performance experiments highest performance values are obtained for the membrane containing 15% boron phosphate at 0.6 V and 750 mA/cm2. Water hold-up capacity, swelling ratio, ion exchange capacity and proton conductivity of this membrane are found as 56%, 8%, 1.36 meq/g and 0.37 S/cm, respectively. These values are close to the values obtained ones for perfluorosulphonic acid membranes. Therefore this membrane can be regarded as a promising candidate for usage in fuel cells.

  8. Fabrication of an rhBMP-2 loaded porous β-TCP microsphere-hyaluronic acid-based powder gel composite and evaluation of implant osseointegration.

    PubMed

    Lee, Jae Hyup; Kim, Jungju; Baek, Hae-Ri; Lee, Kyung Mee; Seo, Jun-Hyuk; Lee, Hyun-Kyung; Lee, A-Young; Zheng, Guang Bin; Chang, Bong-Soon; Lee, Choon-Ki

    2014-09-01

    Methods to improve osseointegration that include implantation of rhBMP-2 with various kinds of carriers are currently of considerable interest. The present study was conducted to evaluate if the rhBMP-2 loaded β-TCP microsphere-hyaluronic acid-based powder-like hydrogel composite (powder gel) can act as an effective rhBMP-2 carrier for implantation in host bone with a bone defect or poor bone quality. The release pattern for rhBMP-2 was then evaluated against an rhBMP-2-loaded collagen sponge as a control group. Dental implants were also inserted into the tibias of three groups of rabbits: an rhBMP-2 (200 µg) loaded powder gel composite implanted group, an implant only group, and a powder gel implanted group. Micro-CT and histology of the implanted areas were carried out four weeks later. The rhBMP-2 powder gel released less rhBMP-2 than the collagen sponge, but it continued a slow release for more than 7 days. The rhBMP-2 powder gel composite improved osseointegration of the dental implant by increasing the amount of new bone formation in the implant pitch and it improved the bone quality and bone quantity of new bone. The histology results indicated that the rhBMP-2 powder gel composite improved the osseointegration in the cortical bone as well as the marrow space along the fixture. The bone-to-implant contact ratio of the rhBMP-2 (200 µg) loaded powder gel composite implanted group was significantly higher than those of the implant only group and the powder gel implanted group. The powder gel appeared to be a good carrier and could release rhBMP-2 slowly to promote the formation of new bone following implantation in a bone defect, thereby improving implant osseointegration.

  9. The Effects of Composition Variation and Nitric Acid on the Stability and Reactivity of the Han-Based Liquid Propellants

    DTIC Science & Technology

    1991-01-01

    predicted by the simple model. Modification of propellant structure would be expected to alter a number of colligative and transport properties . The...content and a number of the physical properties of the propellant The effect of composition variation on performance was studied in order to gain... properties degrading to where they can no longer be used for their intended purpose (Feuer, Rodriguez, and Teets 1988). The result of contact with

  10. High-Performance Flexible Solid-State Carbon Cloth Supercapacitors Based on Highly Processible N-Graphene Doped Polyacrylic Acid/Polyaniline Composites

    PubMed Central

    Wang, Yongguang; Tang, Shaochun; Vongehr, Sascha; Ali Syed, Junaid; Wang, Xiangyu; Meng, Xiangkang

    2016-01-01

    Improving the solubility of conductive polymers to facilitate processing usually decreases their conductivity, and they suffer from poor cycling stability due to swelling-shrinking during charging cycles. We circumvent these problems with a novel preparation method for nitrogen-doped graphene (NG) enhanced polyacrylic acid/polyaniline (NG-PAA/PANI) composites, ensuring excellent processibility for scalable production. The content of PANI is maximized under the constraint of still allowing defect-free coatings on filaments of carbon cloth (CC). The NG content is then adjusted to optimize specific capacitance. The optimal CC electrodes have 32 wt.% PANI and 1.3 wt.% NG, thus achieving a high capacitance of 521 F/g at 0.5 F/g. A symmetric supercapacitor made from 20 wt.% PANI CC electrodes has more than four times the capacitance (68 F/g at 1 A/g) of previously reported flexible capacitors based on PANI-carbon nanotube composites, and it retains the full capacitance under large bending angles. The capacitor exhibits high energy and power densities (5.8 Wh/kg at 1.1 kW/kg), a superior rate capability (still 81% of the 1 A/g capacitance at 10 A/g), and long-term electrochemical stability (83.2% retention after 2000 cycles). PMID:26883179

  11. Synthesis and Application of Novel 3D Magnetic Chlorogenic Acid Imprinted Polymers Based on a Graphene-Carbon Nanotube Composite.

    PubMed

    Yan, Liang; Yin, Yuli; Lv, Piaopiao; Zhang, Zhaohui; Wang, Jing; Long, Fang

    2016-04-20

    A novel three-dimensional (3D) magnetic chlorogenic acid (CGA) imprinted polymer (MMIP) was prepared with novel carbon hybrid nanocomposite as the carrier, chlorogenic acid as the template molecule, and methacrylic acid as the functional monomer. The 3D MMIPs were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, vibrating sample magnetometer, and UV spectrometry in detail. The results showed that the imprinted layer was attached successfully on the surface of a 3D magnetic carbon hybrid nanocomposite. The adsorption performance of the 3D MMIPs was investigated, and the results showed that the 3D MMIPs exhibited high adsorption capacity and fast adsorption rate toward CGA with a maximum adsorption capacity of 10.88 mg g(-1). The extraction conditions involving washing solvent, the pH of eluent solvent, elution volume, and desorption time were also investigated in detail. Combined with high-performance liquid chromatography, the 3D MMIPs have been applied to successfully extract CGA from Eucommia leaf extract samples.

  12. Fabrication of electrochemical interface based on boronic acid-modified pyrroloquinoline quinine/reduced graphene oxide composites for voltammetric determination of glycated hemoglobin.

    PubMed

    Zhou, Yanli; Dong, Hui; Liu, Lantao; Hao, Yuanqiang; Chang, Zhu; Xu, Maotian

    2015-02-15

    A voltammetric sensor for determination of glycated hemoglobin (HbA1c) was developed based on the composites of phenylboronic acid-modified pyrroloquinoline quinine (PBA-PQQ) and reduced graphene oxide. After the electrodeposition of reduced graphene oxide (ERGO) on the glassy carbon (GC) electrode, PQQ multilayer was decorated on the surface of the ERGO/GC electrode via potential cycling. Further modification with PBA would lead to the formation of the working electrode, namely PBA-PQQ/ERGO/GC electrode. PQQ on the electrode exhibited a quasi-reversible electrode process with 2-electron transfer and 2-proton participation, and the electron transfer efficiency was further enhanced by the introduction of ERGO layer. The complexation of PBA with HbA1c through specific boronic acid-diol recognition could cause the change of the oxidation peak current of PQQ on the electrode, which was utilized for HbA1c detection. Under the optimized conditions, the PBA-PQQ/ERGO/GC electrode provided high selectivity and high sensitivity for HbA1c detection with a linear range of 9.4-65.8 μg mL(-1) and a low detection limit of 1.25 μg mL(-1). The fabricated sensor was also successfully applied to determine the percentages of HbA1c in whole blood of healthy individuals.

  13. Methods and compositions for efficient nucleic acid sequencing

    DOEpatents

    Drmanac, Radoje

    2006-07-04

    Disclosed are novel methods and compositions for rapid and highly efficient nucleic acid sequencing based upon hybridization with two sets of small oligonucleotide probes of known sequences. Extremely large nucleic acid molecules, including chromosomes and non-amplified RNA, may be sequenced without prior cloning or subcloning steps. The methods of the invention also solve various current problems associated with sequencing technology such as, for example, high noise to signal ratios and difficult discrimination, attaching many nucleic acid fragments to a surface, preparing many, longer or more complex probes and labelling more species.

  14. Methods and compositions for efficient nucleic acid sequencing

    DOEpatents

    Drmanac, Radoje

    2002-01-01

    Disclosed are novel methods and compositions for rapid and highly efficient nucleic acid sequencing based upon hybridization with two sets of small oligonucleotide probes of known sequences. Extremely large nucleic acid molecules, including chromosomes and non-amplified RNA, may be sequenced without prior cloning or subcloning steps. The methods of the invention also solve various current problems associated with sequencing technology such as, for example, high noise to signal ratios and difficult discrimination, attaching many nucleic acid fragments to a surface, preparing many, longer or more complex probes and labelling more species.

  15. Effect of Glucose on the Fatty Acid Composition of Cupriavidus necator JMP134 during 2,4-Dichlorophenoxyacetic Acid Degradation: Implications for Lipid-Based Stable Isotope Probing Methods▿†

    PubMed Central

    Lerch, Thomas Z.; Dignac, Marie-France; Barriuso, Enrique; Mariotti, André

    2011-01-01

    Combining lipid biomarker profiling with stable isotope probing (SIP) is a powerful technique for studying specific microbial populations responsible for the degradation of organic pollutants in various natural environments. However, the presence of other easily degradable substrates may induce significant physiological changes by altering both the rate of incorporation of the target compound into the biomass and the microbial lipid profiles. In order to test this hypothesis, Cupriavidus necator JMP134, a 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterium, was incubated with [13C]2,4-D, [13C]glucose, or mixtures of both substrates alternatively labeled with 13C. C. necator JMP134 exhibited a preferential use of 2,4-D over glucose. The isotopic analysis showed that glucose had only a small effect on the incorporation of the acetic chain of 2,4-D into the biomass (at days 2 and 3) and no effect on that of the benzenic ring. The addition of glucose did change the fatty acid methyl ester (FAME) composition. However, the overall FAME isotopic signature reflected that of the entire biomass. Compound-specific individual isotopic analyses of FAME composition showed that the 13C-enriched FAME profiles were slightly or not affected when tracing the 2,4-D acetic chain or 2,4-D benzenic ring, respectively. This batch study is a necessary step for validating the use of lipid-based SIP methods in complex environments. PMID:21856833

  16. Development of a novel electrochemical DNA biosensor based on elongated hexagonal-pyramid CdS and poly-isonicotinic acid composite film.

    PubMed

    Zheng, Delun; Wang, Qingxiang; Gao, Feng; Wang, Qinghua; Qiu, Weiwei; Gao, Fei

    2014-10-15

    Three CdS materials with different shapes (i.e., irregular, rod-like, and elongated hexagonal-pyramid) were hydrothermally synthesized through controlling the molar ratio of Cd(2+) to thiourea. Electrochemical experiments showed that the elongated hexagonal-pyramid CdS (eh-CdS) modified on glassy carbon electrode (GCE) had the higher electrical conductivity than the other two forms. Then the eh-CdS modified GCE was further modified with a layer of poly-isonicotinic acid (PIA) through electro-polymerization in IA solution to enhance the stability and functionality of the interface. The layer-by-layer modification process was characterized by atomic force microscopy and electrochemistry. Then 5'-amino functionalized DNA was immobilized on the electrode surface through coupling with the carboxylic groups derived from PIA-eh-CdS composite film. The hybridization performance of the developed biosensor was evaluated using methylene blue as redox indicator, and the results showed that the peak currents of methylene blue varied with target concentrations in a wide linear range from 1.0 × 10(-14)M to 1.0 × 10(-9)M with a low detection limit of 3.9 × 10(-15)M. The biosensor also showed high stability and good discrimination ability to the one-base, three-base mismatched and non-complementary sequence.

  17. Manipulation of Galactolipid Fatty Acid Composition with Substituted Pyridazinones

    PubMed Central

    John, Judith B. St.

    1976-01-01

    The fatty acid composition of the major lipids of the chloroplast membranes, the mono- and digalactosyl diglycerides, can be definably altered with various substituted pyridazinones. Galactolipid fatty acid composition of wheat (Triticum aestivum L.) can be altered so that there is a decrease in linolenic acid accompanied by an increase in linoleic acid without a shift in the relative proportion of saturated to unsaturated fatty acids; the fatty acid composition can be shifted toward a higher proportion of saturated fatty acids; or the fatty acid composition of the monogalactosyl diglycerides can be altered in preference to the digalactosyl diglycerides. Also, the light-mediated parallel accumulation of chlorophyll and linolenic acid can be separated with a substituted pyridazinone. The substituted pyridazinones may be useful tools in clarifying the role the galactolipids and their component fatty acids play in the structure and function of chloroplast membranes in higher plants. PMID:16659420

  18. [Stewart's acid-base approach].

    PubMed

    Funk, Georg-Christian

    2007-01-01

    In addition to paCO(2), Stewart's acid base model takes into account the influence of albumin, inorganic phosphate, electrolytes and lactate on acid-base equilibrium. It allows a comprehensive and quantitative analysis of acid-base disorders. Particularly simultaneous and mixed metabolic acid-base disorders, which are common in critically ill patients, can be assessed. Stewart's approach is therefore a valuable tool in addition to the customary acid-base approach based on bicarbonate or base excess. However, some chemical aspects of Stewart's approach remain controversial.

  19. Amino acid composition predicts prion activity.

    PubMed

    Afsar Minhas, Fayyaz Ul Amir; Ross, Eric D; Ben-Hur, Asa

    2017-04-10

    Many prion-forming proteins contain glutamine/asparagine (Q/N) rich domains, and there are conflicting opinions as to the role of primary sequence in their conversion to the prion form: is this phenomenon driven primarily by amino acid composition, or, as a recent computational analysis suggested, dependent on the presence of short sequence elements with high amyloid-forming potential. The argument for the importance of short sequence elements hinged on the relatively-high accuracy obtained using a method that utilizes a collection of length-six sequence elements with known amyloid-forming potential. We weigh in on this question and demonstrate that when those sequence elements are permuted, even higher accuracy is obtained; we also propose a novel multiple-instance machine learning method that uses sequence composition alone, and achieves better accuracy than all existing prion prediction approaches. While we expect there to be elements of primary sequence that affect the process, our experiments suggest that sequence composition alone is sufficient for predicting protein sequences that are likely to form prions. A web-server for the proposed method is available at http://faculty.pieas.edu.pk/fayyaz/prank.html, and the code for reproducing our experiments is available at http://doi.org/10.5281/zenodo.167136.

  20. Thermal properties of epoxy composites filled with boric acid

    NASA Astrophysics Data System (ADS)

    Visakh, P. M.; Nazarenko, O. B.; Amelkovich, Yu A.; Melnikova, T. V.

    2015-04-01

    The thermal properties of epoxy composites filled with boric acid fine powder at different percentage were studied. Epoxy composites were prepared using epoxy resin ED-20, boric acid as flame-retardant filler, hexamethylenediamine as a curing agent. The prepared samples and starting materials were examined using methods of thermal analysis, scanning electron microscopy and infrared spectroscopy. It was found that the incorporation of boric acid fine powder enhances the thermal stability of epoxy composites.

  1. Fatty Acid Composition of Unicellular Strains of Blue-Green Algae1

    PubMed Central

    Kenyon, C. N.

    1972-01-01

    The fatty acids of 34 strains of unicellular blue-green algae provisionally assigned to the genera Synechococcus, Aphanocapsa, Gloeocapsa, Microcystis, and Chlorogloea by Stanier et al. have been chemically characterized. The strains analyzed can be divided into a series of compositional groups based upon the highest degree of unsaturation of the major cellular fatty acids. Twenty strains fall into the group characterized by one trienoic fatty acid isomer (α-linolenic acid), and seven strains fall into a group characterized by another trienoic acid isomer (γ-linolenic acid). These groups in many cases correlate well with groupings based upon other phenotypic characters of the strains, e.g., deoxyribonucleic acid base composition. The assignment of a strain to a compositional group is not altered when the strain is grown under a variety of different culture conditions. All strains contain glycolipids with the properties of mono- and digalactosyldiglycerides. PMID:4621688

  2. Dietary fish oil supplements depress milk fat yield and alter milk fatty acid composition in lactating cows fed grass silage-based diets.

    PubMed

    Kairenius, P; Ärölä, A; Leskinen, H; Toivonen, V; Ahvenjärvi, S; Vanhatalo, A; Huhtanen, P; Hurme, T; Griinari, J M; Shingfield, K J

    2015-08-01

    The potential of dietary fish oil (FO) supplements to increase milk 20:5n-3 and 22:6n-3 concentrations and the associated effects on milk fatty acid (FA) composition, intake, and milk production were examined. Four multiparous lactating cows offered a grass silage-based diet (forage:concentrate ratio 58:42, on a dry matter basis) supplemented with 0, 75, 150, or 300g of FO/d (FO0, FO75, FO150, and FO300, respectively) were used in a 4×4 Latin square with 28-d experimental periods. Milk FA composition was analyzed by complementary silver-ion thin-layer chromatography, gas chromatography-mass spectrometry, and silver-ion HPLC. Supplements of FO decreased linearly dry matter intake, yields of energy-corrected milk, milk fat and protein, and milk fat content. Compared with FO0, milk fat content and yield were decreased by 30.1 and 40.6%, respectively, on the FO300 treatment. Supplements of FO linearly increased milk 20:5n-3 and 22:6n-3 concentrations from 0.07 to 0.18 and 0.03 to 0.10g/100g of FA, respectively. Enrichment of 20:5n-3 and 22:6n-3 was accompanied by decreases in 4- to 18-carbon saturated FA and increases in total conjugated linoleic acid (CLA), trans FA, and polyunsaturated FA concentrations. Fish oil elevated milk fat cis-9,trans-11 CLA content in a quadratic manner, reaching a maximum on FO150 (from 0.61 to 2.15g/100g of FA), whereas further amounts of FO increased trans-10 18:1 with no change in trans-11 18:1 concentration. Supplements of FO also resulted in a dose-dependent appearance of 37 unique 20- and 22-carbon intermediates in milk fat. Concentrations of 16-, 18-, 20-, and 22-carbon trans FA were all increased by FO, with enrichment of trans 18:1 and trans 18:2 being quantitatively the most important. Decreases in milk fat yield to FO were not related to changes in milk trans-10,cis-12 CLA concentration or estimated milk fat melting point. Partial least square regression analysis indicated that FO-induced milk fat depression was associated with

  3. Influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of acidic, neutral and basic polysaccharides.

    PubMed

    Wang, Qing-Chi; Zhao, Xia; Pu, Jiang-Hua; Luan, Xiao-Hong

    2016-06-05

    Monosaccharide composition analysis is important for structural characterization of polysaccharides. To investigate the influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of polysaccharides, we chose alginate, starch, chitosan and chondroitin sulfate as representative of acidic, neutral, basic and complex polysaccharides to compare the release degree of monosaccharides under different hydrolytic conditions. The hydrolysis stability of 10 monosaccharide standards was also explored. Results showed that the basic sugars were hard to release but stable, the acidic sugars (uronic acids) were easy to release but unstable, and the release and stability of neutral sugars were in between acidic and basic sugars. In addition, the hydrolysis process was applied to monosaccharide composition analysis of Hippocampus trimaculatus polysaccharide and the appropriate hydrolytic condition was accorded with that of the above four polysaccharides. Thus, different hydrolytic conditions should be used for the monosaccharide composition analysis of polysaccharides based on their structural characteristics.

  4. Multifunctional co-poly(amic acid): A new binder for Si-based micro-composite anode of lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Lin, Che-Tseng; Huang, Tzu-Yang; Huang, Jau-Jiun; Wu, Nae-Lih; Leung, Man-kit

    2016-10-01

    Multifunctional co-poly(amic acid) (PAmA) containing pyrene and carboxylic acid side-chains is developed as a binder for the recycled kerf-loss Si-Ni-SiC composite anode. The capacity retention performance of the lithium-ion battery can be apparently enhanced. In a long-cycle test of 300 lithiation/delithiation cycles, 79% of capacity retention is achieved. In considering that the recycled kerf-loss Si sample contains 38 wt% inactive micro-sized SiC abrasive particles, the achieved capacity of 648 mAh g-1 is reasonably high in comparison to other reported values. Small anode thickness expansion of 43% is found in a 100 cycle test, reflecting that the use of the PAmA binder can create strong interconnection among the silicon particles, conductive carbons and copper electrode.

  5. Relative stability of major types of beta-turns as a function of amino acid composition: a study based on Ab initio energetic and natural abundance data.

    PubMed

    Perczel, András; Jákli, Imre; McAllister, Michael A; Csizmadia, Imre G

    2003-06-06

    Folding properties of small globular proteins are determined by their amino acid sequence (primary structure). This holds both for local (secondary structure) and for global conformational features of linear polypeptides and proteins composed from natural amino acid derivatives. It thus provides the rational basis of structure prediction algorithms. The shortest secondary structure element, the beta-turn, most typically adopts either a type I or a type II form, depending on the amino acid composition. Herein we investigate the sequence-dependent folding stability of both major types of beta-turns using simple dipeptide models (-Xxx-Yyy-). Gas-phase ab initio properties of 16 carefully selected and suitably protected dipeptide models (for example Val-Ser, Ala-Gly, Ser-Ser) were studied. For each backbone fold most probable side-chain conformers were considered. Fully optimized 321G RHF molecular structures were employed in medium level [B3LYP/6-311++G(d,p)//RHF/3-21G] energy calculations to estimate relative populations of the different backbone conformers. Our results show that the preference for beta-turn forms as calculated by quantum mechanics and observed in Xray determined proteins correlates significantly.

  6. A multilabel model based on Chou's pseudo-amino acid composition for identifying membrane proteins with both single and multiple functional types.

    PubMed

    Huang, Chao; Yuan, Jing-Qi

    2013-04-01

    Predicting membrane protein type is a meaningful task because this kind of information is very useful to explain the function of membrane proteins. Due to the explosion of new protein sequences discovered, it is highly desired to develop efficient computation tools for quickly and accurately predicting the membrane type for a given protein sequence. Even though several membrane predictors have been developed, they can only deal with the membrane proteins which belong to the single membrane type. The fact is that there are membrane proteins belonging to two or more than two types. To solve this problem, a system for predicting membrane protein sequences with single or multiple types is proposed. Pseudo-amino acid composition, which has proven to be a very efficient tool in representing protein sequences, and a multilabel KNN algorithm are used to compose this prediction engine. The results of this initial study are encouraging.

  7. Relative Amino Acid Composition Signatures of Organisms and Environments

    PubMed Central

    Moura, Alexandra; Savageau, Michael A.; Alves, Rui

    2013-01-01

    Background Identifying organism-environment interactions at the molecular level is crucial to understanding how organisms adapt to and change the chemical and molecular landscape of their habitats. In this work we investigated whether relative amino acid compositions could be used as a molecular signature of an environment and whether such a signature could also be observed at the level of the cellular amino acid composition of the microorganisms that inhabit that environment. Methodologies/Principal Findings To address these questions we collected and analyzed environmental amino acid determinations from the literature, and estimated from complete genomic sequences the global relative amino acid abundances of organisms that are cognate to the different types of environment. Environmental relative amino acid abundances clustered into broad groups (ocean waters, host-associated environments, grass land environments, sandy soils and sediments, and forest soils), indicating the presence of amino acid signatures specific for each environment. These signatures correlate to those found in organisms. Nevertheless, relative amino acid abundance of organisms was more influenced by GC content than habitat or phylogeny. Conclusions Our results suggest that relative amino acid composition can be used as a signature of an environment. In addition, we observed that the relative amino acid composition of organisms is not highly determined by environment, reinforcing previous studies that find GC content to be the major factor correlating to amino acid composition in living organisms. PMID:24204807

  8. Electrochemical behavior and voltammetric determination of acetaminophen based on glassy carbon electrodes modified with poly(4-aminobenzoic acid)/electrochemically reduced graphene oxide composite films.

    PubMed

    Zhu, Wencai; Huang, Hui; Gao, Xiaochun; Ma, Houyi

    2014-12-01

    Poly(4-aminobenzoic acid)/electrochemically reduced graphene oxide composite film modified glassy carbon electrodes (4-ABA/ERGO/GCEs) were fabricated by a two-step electrochemical method. The electrochemical behavior of acetaminophen at the modified electrode was investigated by means of cyclic voltammetry. The results indicated that 4-ABA/ERGO composite films possessed excellent electrocatalytic activity towards the oxidation of acetaminophen. The electrochemical reaction of acetaminophen at 4-ABA/ERGO/GCE is proved to be a surface-controlled process involving the same number of protons and electrons. The voltammetric determination of acetaminophen performed with the 4-ABA/ERGO modified electrode presents a good linearity in the range of 0.1-65 μM with a low detection limit of 0.01 μM (S/N=3). In the case of using the 4-ABA/ERGO/GCE, acetaminophen and dopamine can be simultaneously determined without mutual interference. Furthermore, the 4-ABA/ERGO/GCE has good reproducibility and stability, and can be used to determine acetaminophen in tablets.

  9. Fatty Acid Compositions of Six Wild Edible Mushroom Species

    PubMed Central

    Günç Ergönül, Pelin; Akata, Ilgaz; Kalyoncu, Fatih; Ergönül, Bülent

    2013-01-01

    The fatty acids of six wild edible mushroom species (Boletus reticulatus, Flammulina velutipes var. velutipes, Lactarius salmonicolor, Pleurotus ostreatus, Polyporus squamosus, and Russula anthracina) collected from different regions from Anatolia were determined. The fatty acids were identified and quantified by gas chromatography and studied using fruit bodies. Fatty acid composition varied among species. The dominant fatty acid in fruit bodies of all mushrooms was cis-linoleic acid (18 : 2). Percentage of cis-linoleic acid in species varied from 22.39% to 65.29%. The other major fatty acids were, respectively, cis-oleic, palmitic, and stearic acids. Fatty acids analysis of the mushrooms showed that the unsaturated fatty acids were at higher concentrations than saturated fatty acids. PMID:23844377

  10. Polylactic acid composites incorporating casein functionalized cellulose nanowhiskers

    PubMed Central

    2013-01-01

    Background Polylactic acid (PLA) is considered to be a sustainable alternative to petroleum-based polymers for many applications. Using cellulose fiber to reinforce PLA is of great interest recently due to its complete biodegradability and potential improvement of the mechanical performance. However, the dispersion of hydrophilic cellulose fibers in the hydrophobic polymer matrix is usually poor without using hazardous surfactants. The goal of this study was to develop homogenously dispersed cellulose nanowhisker (CNW) reinforced PLA composites using whole milk casein protein, which is an environmentally compatible dispersant. Results In this study, whole milk casein was chosen as a dispersant in the PLA-CNW system because of its potential to interact with the PLA matrix and cellulose. The affinity of casein to PLA was studied by surface plasmon resonance (SPR) imaging. CNWs were functionalized with casein and used as reinforcements to make PLA composites. Fluorescent staining of CNWs in the PLA matrix was implemented as a novel and simple way to analyze the dispersion of the reinforcements. The dispersion of CNWs in PLA was improved when casein was present. The mechanical properties of the composites were studied experimentally. Compared to pure PLA, the PLA composites had higher Young’s modulus. Casein (CS) functionalized CNW reinforced PLA (PLA-CS-CNW) at 2 wt% filler content maintained higher strain at break compared to normal CNW reinforced PLA (PLA-CNW). The Young’s modulus of PLA-CS-CNW composites was also higher than that of PLA-CNW composites at higher filler content. However, all composites exhibited lower strain at break and tensile strength at high filler content. Conclusions The presence of whole milk casein improved the dispersion of CNWs in the PLA matrix. The improved dispersion of CNWs provided higher modulus of the PLA composites at higher reinforcement loading and maintained the strain and stress at break of the composites at relatively low

  11. Amino acid composition of proteins reduces deleterious impact of mutations

    PubMed Central

    Hormoz, Sahand

    2013-01-01

    The evolutionary origin of amino acid occurrence frequencies in proteins (composition) is not yet fully understood. We suggest that protein composition works alongside the genetic code to minimize impact of mutations on protein structure. First, we propose a novel method for estimating thermodynamic stability of proteins whose sequence is constrained to a fixed composition. Second, we quantify the average deleterious impact of substituting one amino acid with another. Natural proteome compositions are special in at least two ways: 1) Natural compositions do not generate more stable proteins than the average random composition, however, they result in proteins that are less susceptible to damage from mutations. 2) Natural proteome compositions that result in more stable proteins (i.e. those of thermophiles) are also tuned to have a higher tolerance for mutations. This is consistent with the observation that environmental factors selecting for more stable proteins also enhance the deleterious impact of mutations. PMID:24108121

  12. Preparation and analysis of multilayer composites based on polyelectrolyte complexes

    NASA Astrophysics Data System (ADS)

    Petrova, V. A.; Orekhov, A. S.; Chernyakov, D. D.; Baklagina, Yu. G.; Romanov, D. P.; Kononova, S. V.; Volod'ko, A. V.; Ermak, I. M.; Klechkovskaya, V. V.; Skorik, Yu. A.

    2016-11-01

    A method for preparing multilayer film composites based on chitosan has been developed by the example of polymer pairs: chitosan-hyaluronic acid, chitosan-alginic acid, and chitosan-carrageenan. The structure of the composite films is characterized by X-ray diffractometry and scanning electron microscopy. It is shown that the deposition of a solution of hyaluronic acid, alginic acid, or carrageenan on a chitosan gel film leads to the formation of a polyelectrolyte complex layer at the interface, which is accompanied by the ordering of chitosan chains in the surface region; the microstructure of this layer depends on the nature of contacting polymer pairs.

  13. Surface roughness of composite resins subjected to hydrochloric acid.

    PubMed

    Roque, Ana Carolina Cabral; Bohner, Lauren Oliveira Lima; de Godoi, Ana Paula Terossi; Colucci, Vivian; Corona, Silmara Aparecida Milori; Catirse, Alma Blásida Concepción Elizaur Benitez

    2015-01-01

    The purpose of this study was to determine the influence of hydrochloric acid on surface roughness of composite resins subjected to brushing. Sixty samples measuring 2 mm thick x 6 mm diameter were prepared and used as experimental units. The study presented a 3x2 factorial design, in which the factors were composite resin (n=20), at 3 levels: microhybrid composite (Z100), nanofilled composite (FiltekTM Supreme), nanohybrid composite (Ice), and acid challenge (n=10) at 2 levels: absence and presence. Acid challenge was performed by immersion of specimens in hydrochloric acid (pH 1.2) for 1 min, 4 times per day for 7 days. The specimens not subjected to acid challenge were stored in 15 mL of artificial saliva at 37 oC. Afterwards, all specimens were submitted to abrasive challenge by a brushing cycle performed with a 200 g weight at a speed of 356 rpm, totaling 17.8 cycles. Surface roughness measurements (Ra) were performed and analyzed by ANOVA and Tukey test (p≤0.05). Surface roughness values were higher in the presence (1.07±0.24) as compared with the absence of hydrochloric acid (0.72±0.04). Surface roughness values were higher for microhybrid (1.01±0.27) compared with nanofilled (0.68 ±0.09) and nanohybrid (0.48±0.15) composites when the specimens were not subjects to acid challenge. In the presence of hydrochloric acid, microhybrid (1.26±0.28) and nanofilled (1.18±0,30) composites presents higher surface roughness values compared with nanohybrid (0.77±0.15). The hydrochloric acid affected the surface roughness of composite resin subjected to brushing.

  14. Characterization of ribonucleic acids from the venom glands of Crotalus durissus terrificus (Ophidia, Reptilia) after manual extraction of the venom. Studies on template activity and base composition

    PubMed Central

    De Lucca, F. L.; Imaizumi, M. T.; Haddad, A.

    1974-01-01

    RNA synthesis in the venom glands of Crotalus durissus terrificus was stimulated by the manual extraction of the venom (milking). RNA was extracted from venom glands activated by milking and fractionated by centrifugation through sucrose density gradients. Template activity for protein synthesis and base composition of the RNA fractions were studied. RNA fractions that sediment between 18S and 4S had the highest template activity. The base composition analysis indicated that the 28S and 18S rRNA have a C+G content of 65.4 and 58% respectively. The `melting' temperature (Tm) of DNA in 0.15m-NaCl–0.015m-trisodium citrate, pH7.0, was 85°C, corresponding to a C+G content of 38%. The base ratio of the RNA fractions that showed a high template activity was intermediate between that of rRNA and homologous DNA. The possible role of these fractions in the synthesis of the two main toxins (crotoxin and crotamine) of the South American rattlesnake's venom is discussed. ImagesPLATE 1 PMID:4463939

  15. THERMAL PROPERTIES OF EXTRUDED-INJECTION MOLDED POLY (LACTIC ACID) AND MILKWEED COMPOSITES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently, most polymer composites utilize petroleum-based materials that are non-degradable and difficult to recycle or incur substantial cost for disposal. Green composites can be used in nondurable limited applications. In order to determine the degree of compatibility between Poly (Lactic Acid...

  16. Novel amine-based presursor compounds and composite membranes thereof

    DOEpatents

    Lee, Eric K. L.; Tuttle, Mark E.

    1989-01-01

    Novel amine-based precursor compounds comprising the condensation products of dialkylenetriamine and alpha, beta-unsaturated acid halides are disclosed, as well as composite membranes containing such compounds, the membranes being useful in RO-type processes for desalination and the removal of low molecular weight organic compounds such as phenols and carboxylic acids.

  17. Evaluating and predicting the oxidative stability of vegetable oils with different fatty acid compositions.

    PubMed

    Li, Hongyan; Fan, Ya-wei; Li, Jing; Tang, Liang; Hu, Jiang-ning; Deng, Ze-yuan

    2013-04-01

    The aim of this research was to evaluate the oxidative stabilities and qualities of different vegetable oils (almond, blend 1-8, camellia, corn, palm, peanut, rapeseed, sesame, soybean, sunflower, and zanthoxylum oil) based on peroxide value (PV), vitamin E content, free fatty acid, and fatty acid composition. The vegetable oils with different initial fatty acid compositions were studied under accelerated oxidation condition. It showed that PV and n-3 polyunsaturated fatty acid (PUFA) changed significantly during 21 d accelerated oxidation storage. Based on the changes of PV and fatty acid composition during the oxidation process, mathematical models were hypothesized and the models were simulated by Matlab to generate the proposed equations. These equations were established on the basis of the different PUFA contents as 10% to 28%, 28% to 46%, and 46% to 64%, respectively. The simulated models were proven to be validated and valuable for assessing the degree of oxidation and predicting the shelf life of vegetable oils.

  18. Simultaneous determination of ascorbic acid and rutin in pharmaceutical preparations with electrochemical method based on multi-walled carbon nanotubes-chitosan composite film modified electrode.

    PubMed

    Deng, Peihong; Xu, Zhifeng; Li, Junhua

    2013-03-25

    In this paper, the simultaneous voltammetric determination of ascorbic acid (AA) and rutin (Ru) has been achieved at an acetylene black paste electrode modified with multi-walled carbon nanotubes-chitosan composite film (denoted as MWCNTs-CHIT/ABPE). Compared with bare electrode, the peak currents of AA and Ru at MWCNTs-CHIT/ABPE increased greatly and the anodic peak potential difference (ΔE(pa)) between AA and Ru are up to 342mV, which is undoubtedly attributed to the unique characteristics of AB and MWCNTs such as excellent electric conductivity, high surface area and strong adsorptive abilities, resulting in higher accumulation efficiency to AA and Ru. The influences of some experimental conditions on the oxidation of AA and Ru were tested and the calibration plot was examined. Under the optimized condition, a good linearity was obtained in the concentration range of 1μM-0.4mM for AA in the presence of 10μM Ru and 20nM-10μM for Ru in the presence of 1mM AA. The detection limits (S/N=3) of AA and Ru are 0.8μM and 10nM, respectively. The proposed method was successfully applied to the simultaneous determination of AA and Ru in pharmaceutical samples with reliable recovery.

  19. Polyphenolic drug composition based on benzenepolycarboxylic acids (BP-C3) increases life span and inhibits spontaneous tumorigenesis in female SHR mice

    PubMed Central

    Anisimov, Vladimir N.; Popovich, Irina G.; Zabezhinski, Mark A.; Yurova, Maria N.; Tyndyk, Margarita L.; Anikin, Ivan V.; Egormin, Peter A.; Baldueva, Irina A.; Fedoros, Elena I.; Pigarev, Sergey E.; Panchenko, Andrey V.

    2016-01-01

    Effects of long-term application of novel polyphenolic composition BP-C3, containing polyphenolic benzenepolycarboxylic acids, vitamins and minerals on some biomarkers of aging, life span and spontaneous tumorigenesis has been studied in female SHR mice. Administration of BP-C3 with drinking water (0.005%) did not exert any toxic effect (did not have effect on general condition of animals, weight dynamics and consumption of food), postponed age-related switch-off of estrous function, caused slight reduction of body temperature. An increased survival was observed in mice treated with BP-C3 (p=0.00164, log rank test). BP-C3 increased mean lifespan – by 8.4%, lifespan of the last 10% of animals – by 12.4%, and life span of tumor-free mice – by 11.6%. A tendency in ability of BP-C3 to inhibit development of spontaneous tumors in mice was detected, though it did not reach the level of statistical significance (p=0.166, log rank test). The number of malignant mammary tumors was 1.5 times less and total number of tumors of various localizations was 1.6 times less in BP-C3 treated animals. Multiple tumors were registered in 8% of mice in the control group and no cases – in BP-C3 treated group. Thus, BP-C3 demonstrated some anti-carcinogenic and a pronounced geroprotective activity. PMID:27574962

  20. Polyphenolic drug composition based on benzenepolycarboxylic acids (BP-C3) increases life span and inhibits spontaneous tumorigenesis in female SHR mice.

    PubMed

    Anisimov, Vladimir N; Popovich, Irina G; Zabezhinski, Mark A; Yurova, Maria N; Tyndyk, Margarita L; Anikin, Ivan V; Egormin, Peter A; Baldueva, Irina A; Fedoros, Elena I; Pigarev, Sergey E; Panchenko, Andrey V

    2016-08-28

    Effects of long-term application of novel polyphenolic composition BP-C3, containing polyphenolic benzenepolycarboxylic acids, vitamins and minerals on some biomarkers of aging, life span and spontaneous tumorigenesis has been studied in female SHR mice. Administration of BP-C3 with drinking water (0.005%) did not exert any toxic effect (did not have effect on general condition of animals, weight dynamics and consumption of food), postponed age-related switch-off of estrous function, caused slight reduction of body temperature. An increased survival was observed in mice treated with BP-C3 (p=0.00164, log rank test). BP-C3 increased mean lifespan - by 8.4%, lifespan of the last 10% of animals - by 12.4%, and life span of tumor-free mice - by 11.6%. A tendency in ability of BP-C3 to inhibit development of spontaneous tumors in mice was detected, though it did not reach the level of statistical significance (p=0.166, log rank test). The number of malignant mammary tumors was 1.5 times less and total number of tumors of various localizations was 1.6 times less in BP-C3 treated animals. Multiple tumors were registered in 8% of mice in the сontrol group and no cases - in BP-C3 treated group. Thus, BP-C3 demonstrated some anti-carcinogenic and a pronounced geroprotective activity.

  1. Expression-based GWAS identifies variants, gene interactions and key regulators affecting intramuscular fatty acid content and composition in porcine meat

    PubMed Central

    Puig-Oliveras, Anna; Revilla, Manuel; Castelló, Anna; Fernández, Ana I.; Folch, Josep M.; Ballester, Maria

    2016-01-01

    The aim of this work is to better understand the genetic mechanisms determining two complex traits affecting porcine meat quality: intramuscular fat (IMF) content and its fatty acid (FA) composition. With this purpose, expression Genome-Wide Association Study (eGWAS) of 45 lipid-related genes associated with meat quality traits in swine muscle (Longissimus dorsi) of 114 Iberian × Landrace backcross animals was performed. The eGWAS identified 241 SNPs associated with 11 genes: ACSM5, CROT, FABP3, FOS, HIF1AN, IGF2, MGLL, NCOA1, PIK3R1, PLA2G12A and PPARA. Three expression Quantitative Trait Loci (eQTLs) for IGF2, ACSM5 and MGLL were identified, showing cis-acting effects, whereas 16 eQTLs had trans regulatory effects. A polymorphism in the ACSM5 promoter region associated with its expression was identified. In addition, strong candidate genes regulating ACSM5, FOS, PPARA, PIK3R1, PLA2G12A and HIF1AN gene expression were also seen. Notably, the analysis highlighted the NR3C1 transcription factor as a strong candidate gene involved in the regulation of the 45 genes analysed. Finally, the IGF2, MGLL, MC2R, ARHGAP6, and NR3C1 genes were identified as potential regulators co-localizing within QTLs for fatness and growth traits in the IBMAP population. The results obtained increase our knowledge in the functional regulatory mechanisms involved in these complex traits. PMID:27666082

  2. The fatty acid, amino acid, and mineral composition of Egyptian goose meat as affected by season, gender, and portion.

    PubMed

    Geldenhuys, Greta; Hoffman, Louwrens C; Muller, Nina

    2015-05-01

    With the current absence of scientific information on the nutritive aspects it is essential to investigate the fatty acid, mineral, and amino acid composition of Egyptian geese as well as the factors of influence. The forage vs. grain based diets of Egyptian geese during certain periods of the yr leads to variation in the content of the key fatty acids such as oleic acid, linoleic acid, and α-linolenic acid. The differences in these fatty acids results in variation between the n-6/n-3 ratios of the seasons; the portions from winter (July) are within the recommendations (ratio <5) and those from summer (November) not. This study indicates that Egyptian goose meat does not only vary in nutritional composition but season may also have a substantial effect on the flavor profile and ultimate uniformity of the meat. The season and portion effects were, however, interlinked but the general tendency shows that the portions, especially the breast and thigh do differ concerning the major fatty acids. No substantial differences were found in the mineral composition of the breast portion on account of season and gender; however there were some variation in certain amino acids such as lysine and arginine due to season/diet. This research provides essential information that should be considered not only regarding the everyday consumption of Egyptian goose meat but the potential utilization and ultimate consistency of this meat product.

  3. Fatty acid composition of Tilia spp. seed oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As part of a study of the seed oil fatty acid composition of Malvaceae plants, seeds of seven Tilia species (limes or linden trees) were evaluated for their fatty acid profiles. Seeds were obtained from the Germplasm Research Information Network and from various commercial sources. After extractio...

  4. Fatty acid composition of two Tunisian pine seed oils.

    PubMed

    Nasri, Nizar; Khaldi, Abdelhamid; Hammami, Mohamed; Triki, Saida

    2005-01-01

    Oils were extracted from fully ripen Pinus pinea L. and Pinus halepensis Mill seeds and fatty acid composition has been established by capillary gas chromatography. Seeds are rich in lipids, 34.63-48.12% on a dry weight basis. Qualitatively, fatty acid composition of both species is identical. For P. halepensis linoleic acid is the major fatty acid (56.06% of total fatty acids) followed by oleic (24.03%) and palmitic (5.23%) acids. For P. pinea, the same fatty acids are found with the proportions 47.28%, 36.56%, and 6.67%, respectively. Extracted fatty acids from both species are mainly unsaturated, respectively, 89.87% and 88.01%. Pinus halepensis cis-5 olefinic acids are more abundant (7.84% compared to 2.24%). Results will be important as a good indication of the potential nutraceutical value of Pinus seeds as new sources of fruit oils rich in polyunsaturated fatty acids and cis-5 olefinic acids.

  5. Silicon-based nanoenergetic composites

    SciTech Connect

    Asay, Blaine; Son, Steven; Mason, Aaron; Yarrington, Cole; Cho, K Y; Gesner, J; Yetter, R A

    2009-01-01

    Fundamental combustion properties of silicon-based nano-energetic composites was studied by performing equilibrium calculations, 'flame tests', and instrumented burn-tube tests. That the nominal maximum flame temperature and for many Si-oxidizer systems is about 3000 K, with exceptions. Some of these exceptions are Si-metal oxides with temperatures ranging from 2282 to 2978 K. Theoretical maximum gas production of the Si composites ranged from 350-6500 cm{sup 3}/g of reactant with NH{sub 4}ClO{sub 4} - Si producing the most gas at 6500 cm{sup 3}/g and Fe{sub 2}O{sub 3} producing the least. Of the composites tested NH{sub 4}ClO{sub 4} - Si showed the fastest burning rates with the fastest at 2.1 km/s. The Si metal oxide burning rates where on the order of 0.03-75 mls the slowest of which was nFe{sub 2}O{sub 3} - Si.

  6. Solid Acid Based Fuel Cells

    DTIC Science & Technology

    2007-11-02

    superprotonic solid acids with elements such as P, As, Si and Ge, which have greater affinities to oxygen , we anticipate that the reduction reaction will be...bulk material consisted of an apatite phase (hexagonal symmetry) of variable composition, LixLa10-x(SiO4)6O3-x, with excess lithium residing in the...in Tables 1 and 2, indicate that this compound is a rather conventional apatite with fixed stoichiometry, LiLa9(SiO4)6O2 (x = 1). Such a result is

  7. Nucleic acids, compositions and uses thereof

    DOEpatents

    Preston, III, James F.; Chow, Virginia [Gainesville, FL; Nong, Guang [Gainesville, FL; Rice, John D [Gainesville, FL; John, Franz J [Baltimore, MD

    2012-02-21

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

  8. Nucleic acid compositions and the encoding proteins

    DOEpatents

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

    2014-09-02

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

  9. Fatty acid composition of selected macrophytes.

    PubMed

    Patarra, R F; Leite, J; Pereira, R; Baptista, J; Neto, A I

    2013-04-01

    The content of total lipids and the fatty acid (FA) profile were determined for eight macroalgae (Cystoseira abies-marina, Fucus spiralis, Chaetomorpha pachynema, Codium elisabethae, Porphyra sp., Osmundea pinnatifida, Pterocladiella capillacea and Sphaeroccoccus coronopifolius). Total lipids were extracted using a solvent mixture of methanol/chloroform (2/1, v/v) and further derivatised to FA methyl esters (FAME). The analyses of FAME samples were performed by gas chromatography coupled to a flame ionisation detector. The total lipid content ranged from 0.06 to 3.54 g (per 100 g). The most abundant saturated FA were palmitic (C16:0) and myristic (C14:0), while oleic (C18:1 n-9) was the dominant monounsaturated acid. All seaweeds contained linoleic FA (C18:2 n-6). The α-linolenic (C18:3 n-3) and eicosapentaenoic (20:5 n-3) acids were present only in Porphyra sp. (3.34% ± 0.13) and C. pachynema (0.47% ± 0.12), respectively. The n-6/n-3 and h/H ratios were low, suggesting a high nutritional value of the algae studied.

  10. Effects of supplementation with fish oil and barium selenate on performance, carcass characteristics and muscle fatty acid composition of late season lamb finished on grass-based or concentrate-based diets.

    PubMed

    Annett, R W; Carson, A F; Fearon, A M; Kilpatrick, D J

    2011-12-01

    The objectives of this study were to investigate the effects of fish oil supplementation on performance and muscle fatty acid composition of hill lambs finished on grass-based or concentrate-based diets, and to examine the interaction with selenium (Se) status. In September 2006, 180 entire male lambs of mixed breeds were sourced from six hill farms after weaning and finished on five dietary treatments: grazed grass (GG), grass +0.4 kg/day cereal-based concentrate (GC), grass +0.4 kg/day cereal-based concentrate enriched with fish oil (GF), ad libitum cereal-based concentrate (HC) and ad libitum fish oil-enriched concentrate (HF). Within each treatment, half of the lambs were also supplemented with barium selenate by subcutaneous injection. At the start of the trial, the proportion of lambs with a marginal (<0.76 μmol/l) or deficient (<0.38 μmol/l) plasma Se status was 0.84 and 0.39, respectively. Compared with control lambs, GG lambs treated with Se had higher (P < 0.01) plasma Se levels, whereas erythrocyte glutathione peroxidase activity was higher (P < 0.01) for Se-supplemented lambs fed diets GG and GF. However, Se supplementation had no effects on any aspect of animal performance. Fish oil increased (P < 0.05) levels of 22:5n-3 and 22:6n-3 in the Longissimus dorsi of HF lambs but otherwise had no effect on the health attributes of lamb meat. There were no significant effects of fish oil on dry matter intake, animal performance or lamb carcass characteristics. Daily carcass weight gain (CWG; P < 0.001), carcass weight (P < 0.01) and conformation score (P < 0.01) increased with increasing concentrate inputs. Lambs fed concentrate-based diets achieved a higher mean CWG (P < 0.001), dressing proportion (P < 0.001) and carcass weight (P < 0.011), and were slaughtered up to 8.3 days earlier (P < 0.05) and at 1.2 kg lower (P < 0.05) live weight than pasture-fed lambs. However, carcasses from grass-fed lambs contained lower levels of perinephric and retroperitoneal

  11. Variation in amino acid and lipid composition of latent fingerprints.

    PubMed

    Croxton, Ruth S; Baron, Mark G; Butler, David; Kent, Terry; Sears, Vaughn G

    2010-06-15

    The enhancement of latent fingerprints, both at the crime scene and in the laboratory using an array of chemical, physical and optical techniques, permits their use for identification. Despite the plethora of techniques available, there are occasions when latent fingerprints are not successfully enhanced. An understanding of latent fingerprint chemistry and behaviour will aid the improvement of current techniques and the development of novel ones. In this study the amino acid and fatty acid content of 'real' latent fingerprints collected on a non-porous surface was analysed by gas chromatography-mass spectrometry. Squalene was also quantified in addition. Hexadecanoic acid, octadecanoic acid and cis-9-octadecenoic acid were the most abundant fatty acids in all samples. There was, however, wide variation in the relative amounts of each fatty acid in each sample. It was clearly demonstrated that touching sebum-rich areas of the face immediately prior to fingerprint deposition resulted in a significant increase in the amount of fatty acids and squalene deposited in the resulting 'groomed' fingerprints. Serine was the most abundant amino acid identified followed by glycine, alanine and aspartic acid. The significant quantitative differences between the 'natural' and 'groomed' fingerprint samples seen for fatty acids were not observed in the case of the amino acids. This study demonstrates the variation in latent fingerprint composition between individuals and the impact of the sampling protocol on the quantitative analysis of fingerprints.

  12. Electrophoretic deposition of tannic acid-polypyrrolidone films and composites.

    PubMed

    Luo, Dan; Zhang, Tianshi; Zhitomirsky, Igor

    2016-05-01

    Thin films of polyvinylpyrrolidone (PVP)-tannic acid (TA) complexes were prepared by a conceptually new strategy, based on electrophoretic deposition (EPD). Proof of concept investigations involved the analysis of the deposition yield, FTIR and UV-vis spectroscopy of the deposited material, and electron microscopy studies. The analysis of the deposition mechanism indicated that the limitations of the EPD in the deposition of small phenolic molecules, such as TA, and electrically neutral polymers, similar to PVP, containing hydrogen-accepting carbonyl groups, can be avoided. The remarkable adsorption properties of TA and film forming properties of the PVP-TA complexes allowed for the EPD of materials of different types, such as huntite mineral platelets and hydrotalcite clay particles, TiO2 and MnO2 oxide nanoparticles, multiwalled carbon nanotubes, TiN and Pd nanoparticles. Moreover, PVP-TA complexes were used for the co-deposition of different materials and formation of composite films. In another approach, TA was used as a capping agent for the hydrothermal synthesis of ZnO nanorods, which were then deposited by EPD using PVP-TA complexes. The fundamental adsorption and interaction mechanisms of TA involved chelation of metal atoms on particle surfaces with galloyl groups, π-π interactions and hydrogen bonding. The films prepared by EPD can be used for various applications, utilizing functional properties of TA, PVP, inorganic and organic materials of different types and their composites.

  13. An electrochemical sensor for gallic acid based on Fe₂O₃/electro-reduced graphene oxide composite: Estimation for the antioxidant capacity index of wines.

    PubMed

    Gao, Feng; Zheng, Delun; Tanaka, Hidekazu; Zhan, Fengping; Yuan, Xiaoning; Gao, Fei; Wang, Qingxiang

    2015-12-01

    A highly sensitive electrochemical sensor for gallic acid (GA), an important polyphenolic compound, was fabricated using the hybrid material of chitosan (CS), fishbone-shaped Fe2O3 (fFe2O3), and electrochemically reduced graphene oxide (ERGO) as the sensing matrix. The electrochemical characterization experiments showed that the CS-fFe2O3-ERGO modified glassy carbon electrode (CS-fFe2O3-ERGO/GCE) had large surface area, excellent electronic conductivity and high stability. The GA presented a superior electrochemical response on CS-fFe2O3-ERGO/GCE in comparison with the single-component modified electrode. The electrochemical mechanism and optimal test conditions of GA on the electrode surface were carefully investigated. Under the optimal conditions, the oxidation peak currents in differential pulse voltammetry (DPV) experiments exhibited a good linear relationship with the logarithmic values of GA concentration over the range from 1.0×10(-6)M to 1.0×10(-4)M. Based on signal-to-noise (S/N) characteristic of 3, the detection limit was estimated to be 1.5×10(-7)M. The proposed sensor has also been applied for estimating the antioxidant capacity index of real samples of red and white wines.

  14. Synthesis and swelling behavior of Protein-g-poly Methacrylic acid/kaolin superabsorbent hydrogel composites

    NASA Astrophysics Data System (ADS)

    Sadeghi, Mohammad

    2008-08-01

    A novel superabsorbent hydrogel composite based on Collagen have been prepared via graft copolymerization of Methacrylic acid (MAA) in the presence of kaolin powder using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The composite structure was confirmed using FTIR spectroscopy. A new absorption band at 1728 cm-1 in the composite spectrum confirmed kaolin-organic polymer linkage. The effect of kaolin amount and MBA concentration showed that with increasing of these parameters, the water absorbency of the superabsorbent composite was decreased. The swelling measurements of the hydrogels were conducted in aqueous salt solutions.

  15. Effects of Nano-hydroxyapatite/Poly(DL-lactic-co-glycolic acid) Microsphere-Based Composite Scaffolds on Repair of Bone Defects: Evaluating the Role of Nano-hydroxyapatite Content.

    PubMed

    He, Shu; Lin, Kai-Feng; Sun, Zhen; Song, Yue; Zhao, Yi-Nan; Wang, Zheng; Bi, Long; Liu, Jian

    2016-07-01

    The aim of the current study was to prepare microsphere-based composite scaffolds made of nano-hydroxyapatite (nHA)/poly (DL-lactic-co-glycolic acid) (PLGA) at different ratios and evaluate the effects of nHA on the characteristics of scaffolds for tissue engineering application. First, microsphere-based composite scaffolds made of two ratios of nHA/PLGA (nHA/PLGA = 20/80 and nHA/PLGA = 50/50) were prepared. Then, the effects of nHA on the wettability, mechanical strength, and degradation of scaffolds were investigated. Second, the biocompatibility and osteoinductivity were evaluated and compared by co-culture of scaffolds with bone marrow stromal stem cells (BMSCs). The results showed that the adhesion, proliferation, and osteogenic differentiation of BMSCs with nHA/PLGA (50/50) were better than those with nHA/PLGA (20/80). Finally, we implanted the scaffolds into femur bone defects in a rabbit model, then the capacity of guiding bone regeneration as well as the in vivo degradation were observed by micro-CT and histological examinations. After 4 weeks' implantation, there was no significant difference on the repair of bone defects. However, after 8 and 12 weeks' implantation, the nHA/PLGA (20/80) exhibited better bone formation than nHA/PLGA (50/50). These results suggested that a proper concentration of nHA in the nHA/PLGA composite should be taken into account when the composite scaffolds were prepared, which plays an important role in the biocompatibility, degradation rate and osteoconductivity.

  16. In vitro biostability evaluation of polyurethane composites in acidic, basic, oxidative, and neutral solutions.

    PubMed

    Lyu, Suping; Schley, James; Loy, Brian; Luo, Lian; Hobot, Chris; Sparer, Randall; Untereker, Darrel; Krzeszak, Jason

    2008-05-01

    New and improved properties can often be achieved by compounding two or more different but compatible materials. But, can failure possibility also be increased by such a compounding strategy? In this article, we compared the in vitro biostability of composites with that of the pure polymer. We tested three model composites in oxidative, acidic, basic, and neutral solutions. We found that oxidation degradation was much more profound in the composites than in the corresponding pure polymer. This degradation seemed to be an intrinsic property of composite materials. We also observed the well documented interfacial debonding between filler and matrix and its effects on the mechanical reinforcement of the hydrated composites. The improvements in acid and base resistance were also observed.

  17. Graphene-based Composite Materials

    NASA Astrophysics Data System (ADS)

    Rafiee, Mohammad Ali

    We investigated the mechanical properties, such as fracture toughness (KIc), fracture energy (GIc), ultimate tensile strength (UTS), Young¡¦s modulus (E), and fatigue crack propagation rate (FCPR) of epoxy-matrix composites with different weight fractions of carbon-based fillers, including graphene platelets (GPL), graphene nanoribbons (GNR), single-walled carbon nanotubes (SWNT), multi-walled carbon nanotubes (MWNT), and fullerenes (C60). Only ˜0.125 wt.% GPL was found to increase the KIc of the pure epoxy by ˜65% and the GIc by ˜115%. To get similar improvement, CNT and nanoparticle epoxy composites required one to two orders of magnitude greater weight fraction of nanofillers. Moreover, ˜0.125% wt.% GPL also decreased the fatigue crack propagation rate in the epoxy by ˜30-fold. The E value of 0.1 wt.% GPL/epoxy nanocomposite was ˜31% larger than the pure epoxy while there was only an increase of ˜3% for the SWNT composites. The UTS of the pristine epoxy was improved by ˜40% with GPLs in comparison with ˜14% enhancement for the MWNTs. The KIc of the GPL nanocomposite enhanced by ˜53% over the pristine epoxy compared to a ˜20% increase for the MWNT-reinforced composites. The results of the FCPR tests for the GPL nanocomposites showed a different trend. While the CNT nanocomposites were not effective enough to suppress the crack growth at high values of the stress intensity factor (DeltaK), the reverse behavior is observed for the GPL nanocomposites. The advantage of the GPLs over CNTs in terms of mechanical properties enhancement is due to their enormous specific surface area, enhanced adhesion at filler/epoxy interface (because of the wrinkled surfaces of GPLs), as well as the planar structure of the GPLs. We also show that unzipping of MWNTs into graphene nanoribbons (GNRs) enhances the load transfer effectiveness in epoxy nanocomposites. For instance, at ˜0.3 wt.% of fillers, the Young's modulus (E) of the epoxy nanocomposite with GNRs increased

  18. [Amino acid composition of the rat quadriceps femoris muscle after a flight on the Kosmos-936 biosatellite].

    PubMed

    Vlasova, T F; Miroshnikova, E B; Poliakov, V V; Murugova, T P

    1982-01-01

    The amino acid composition of the quadriceps muscle of rats flown onboard the biosatellite Cosmos-936 and exposed to the ground-based synchronous control experiment was studied. The weightless rats showed changes in the amino acid concentration in the quadriceps muscle. The centrifuged flight and synchronous rats displayed an accumulation of free amino acids in the above muscle.

  19. Subgrouping of Pseudomonas cepacia by cellular fatty acid composition.

    PubMed Central

    Mukwaya, G M; Welch, D F

    1989-01-01

    The cellular fatty acid compositions were determined for 42 strains of Pseudomonas cepacia from five cystic fibrosis centers in North America. All isolates contained significant (20%) amounts of hexadecanoic (C16:0), and cis-9 hexadecenoic (C16:1 cis9) acids and an isomer of octadecenoic acid (C18:1). None had hydroxy acids containing fewer than 14 carbon atoms. The quantitative data from the fatty acid analysis were highly reproducible and provided a basis for numerical analysis. Five subgroups comprising all the strains were obtained by cluster analysis and further characterized by principal-component analysis. With minor exceptions, the predominant subgroup identified in each center was different from that identified in other centers and accounted for one-half of the isolates within each center. Cellular fatty acid composition is a useful adjunct to biochemical characterization for the identification of P. cepacia isolated from cystic fibrosis patients. Numerical analysis of the fatty acid data can separate P. cepacia into subgroups, which may provide useful epidemiologic information or a basis for further analysis by more complex techniques such as DNA probe analysis. PMID:2687315

  20. Corrosion of graphite composites in phosphoric acid fuel cells

    NASA Technical Reports Server (NTRS)

    Christner, L. G.; Dhar, H. P.; Farooque, M.; Kush, A. K.

    1986-01-01

    Polymers, polymer-graphite composites and different carbon materials are being considered for many of the fuel cell stack components. Exposure to concentrated phosphoric acid in the fuel cell environment and to high anodic potential results in corrosion. Relative corrosion rates of these materials, failure modes, plausible mechanisms of corrosion and methods for improvement of these materials are investigated.

  1. Additive Manufacturing and Characterization of Polylactic Acid (PLA) Composites Containing Metal Reinforcements

    NASA Technical Reports Server (NTRS)

    Kuentz, Lily; Salem, Anton; Singh, M.; Halbig, M. C.; Salem, J. A.

    2016-01-01

    Additive manufacturing of polymeric systems using 3D printing has become quite popular recently due to rapid growth and availability of low cost and open source 3D printers. Two widely used 3D printing filaments are based on polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS) systems. PLA is much more environmentally friendly in comparison to ABS since it is made from renewable resources such as corn, sugarcane, and other starches as precursors. Recently, polylactic acid-based metal powder containing composite filaments have emerged which could be utilized for multifunctional applications. The composite filaments have higher density than pure PLA, and the majority of the materials volume is made up of polylactic acid. In order to utilize functionalities of composite filaments, printing behavior and properties of 3-D printed composites need to be characterized and compared with the pure PLA materials. In this study, pure PLA and composite specimens with different metallic reinforcements (Copper, Bronze, Tungsten, Iron, etc) were 3D printed at various layer heights and resulting microstructures and properties were characterized. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) behavior of filaments with different reinforcements were studied. The microscopy results show an increase in porosity between 3-D printed regular PLA and the metal composite PLA samples, which could produce weaker mechanical properties in the metal composite materials. Tensile strength and fracture toughness behavior of specimens as a function of print layer height will be presented.

  2. Nucleic acid based logical systems.

    PubMed

    Han, Da; Kang, Huaizhi; Zhang, Tao; Wu, Cuichen; Zhou, Cuisong; You, Mingxu; Chen, Zhuo; Zhang, Xiaobing; Tan, Weihong

    2014-05-12

    Researchers increasingly visualize a significant role for artificial biochemical logical systems in biological engineering, much like digital logic circuits in electrical engineering. Those logical systems could be utilized as a type of servomechanism to control nanodevices in vitro, monitor chemical reactions in situ, or regulate gene expression in vivo. Nucleic acids (NA), as carriers of genetic information with well-regulated and predictable structures, are promising materials for the design and engineering of biochemical circuits. A number of logical devices based on nucleic acids (NA) have been designed to handle various processes for technological or biotechnological purposes. This article focuses on the most recent and important developments in NA-based logical devices and their evolution from in vitro, through cellular, even towards in vivo biological applications.

  3. Method of preparing and using and composition for acidizing subterranean formations

    SciTech Connect

    Dill, W.R.

    1984-08-21

    A composition and method of acidizing or fracturing a subterranean formation comprises contacting the formation with a composition comprising an acid, urea, and a selected gelling agent. The urea is present in an amount sufficient to extend the viscous stability of the gelled acid composition in comparison to the acid and gelling agent alone.

  4. Continuous microcellular foaming of polylactic acid/natural fiber composites

    NASA Astrophysics Data System (ADS)

    Diaz-Acosta, Carlos A.

    Poly(lactic acid) (PLA), a biodegradable thermoplastic derived from renewable resources, stands out as a substitute to petroleum-based plastics. In spite of its excellent properties, commercial applications are limited because PLA is more expensive and more brittle than traditional petroleum-based resins. PLA can be blended with cellulosic fibers to reduce material cost. However, the lowered cost comes at the expense of flexibility and impact strength, which can be enhanced through the production of microcellular structures in the composite. Microcellular foaming uses inert gases (e.g., carbon dioxide) as physical blowing agents to make cellular structures with bubble sizes of less than 10 microm and cell-population densities (number of bubbles per unit volume) greater than 109 cells/cm³. These unique characteristics result in a significant increase in toughness and elongation at break (ductility) compared with unfoamed parts because the presence of small bubbles can blunt the crack-tips increasing the energy needed to propagate the crack. Microcellular foams have been produced through a two step batch process. First, large amounts of gas are dissolved in the solid plastic under high pressure (sorption process) to form a single-phase solution. Second, a thermodynamic instability (sudden drop in solubility) triggers cell nucleation and growth as the gas diffuses out of the plastic. Batch production of microcellular PLA has addressed some of the drawbacks of PLA. Unfortunately, the batch foaming process is not likely to be implemented in the industrial production of foams because it is not cost-effective. This study investigated the continuous microcellular foaming process of PLA and PLA/wood-fiber composites. The effects of the processing temperature and material compositions on the melt viscosity, pressure drop rate, and cell-population density were examined in order to understand the nucleation mechanisms in neat and filled PLA foams. The results indicated that

  5. Alumina-based ceramic composite

    DOEpatents

    Alexander, Kathleen B.; Tiegs, Terry N.; Becher, Paul F.; Waters, Shirley B.

    1996-01-01

    An improved ceramic composite comprising oxide ceramic particulates, nonoxide ceramic particulates selected from the group consisting of carbides, borides, nitrides of silicon and transition metals and mixtures thereof, and a ductile binder selected from the group consisting of metallic, intermetallic alloys and mixtures thereof is described. The ceramic composite is made by blending powders of the ceramic particulates and the ductile to form a mixture and consolidating the mixture of under conditions of temperature and pressure sufficient to produce a densified ceramic composite.

  6. An In Vivo Study of Composite Microgels Based on Hyaluronic Acid and Gelatin for the Reconstruction of Surgically Injured Rat Vocal Folds

    ERIC Educational Resources Information Center

    Coppoolse, Jiska M. S.; Van Kooten, T. G.; Heris, Hossein K.; Mongeau, Luc; Li, Nicole Y. K.; Thibeault, Susan L.; Pitaro, Jacob; Akinpelu, Olubunm; Daniel, Sam J.

    2014-01-01

    Purpose: The objective of this study was to investigate local injection with a hierarchically microstructured hyaluronic acid-gelatin (HA-Ge) hydrogel for the treatment of acute vocal fold injury using a rat model. Method: Vocal fold stripping was performed unilaterally in 108 Sprague-Dawley rats. A volume of 25 µl saline (placebo controls),…

  7. Lactic acid fermentation by cells immobilised on various porous cellulosic materials and their alginate/poly-lactic acid composites.

    PubMed

    Kumar, Mrinal Nishant; Gialleli, Angelika-Ioanna; Masson, Jean Bernard; Kandylis, Panagiotis; Bekatorou, Argyro; Koutinas, Athanasios A; Kanellaki, Maria

    2014-08-01

    Porous delignified cellulose (or tubular cellulose, abbr. TC) from Indian Mango (Mangifera indica) and Sal (Shorea robusta) wood and Rice husk, and TC/Ca-alginate/polylactic acid composites, were used as Lactobacillus bulgaricus immobilisation carriers leading to improvements in lactic acid fermentation of cheese whey and synthetic lactose media, compared to free cells. Specifically, shorter fermentation rates, higher lactic acid yields (g/g sugar utilised) and productivities (g/Ld), and higher amounts of volatile by-products were achieved, while no significant differences were observed on the performance of the different immobilised biocatalysts. The proposed biocatalysts are of food grade purity, cheap and easy to prepare, and they are attractive for bioprocess development based on immobilised cells. Such composite biocatalysts may be used for the co-immobilisation of different microorganisms or enzymes (in separate layers of the biocatalyst), to efficiently conduct different types of fermentations in the same bioreactor, avoiding inhibition problems of chemical or biological (competition) nature.

  8. Meteoritic Amino Acids: Diversity in Compositions Reflects Parent Body Histories

    PubMed Central

    2016-01-01

    The analysis of amino acids in meteorites dates back over 50 years; however, it is only in recent years that research has expanded beyond investigations of a narrow set of meteorite groups (exemplified by the Murchison meteorite) into meteorites of other types and classes. These new studies have shown a wide diversity in the abundance and distribution of amino acids across carbonaceous chondrite groups, highlighting the role of parent body processes and composition in the creation, preservation, or alteration of amino acids. Although most chiral amino acids are racemic in meteorites, the enantiomeric distribution of some amino acids, particularly of the nonprotein amino acid isovaline, has also been shown to vary both within certain meteorites and across carbonaceous meteorite groups. Large l-enantiomeric excesses of some extraterrestrial protein amino acids (up to ∼60%) have also been observed in rare cases and point to nonbiological enantiomeric enrichment processes prior to the emergence of life. In this Outlook, we review these recent meteoritic analyses, focusing on variations in abundance, structural distributions, and enantiomeric distributions of amino acids and discussing possible explanations for these observations and the potential for future work. PMID:27413780

  9. Five Empirically Based Composition Skills.

    ERIC Educational Resources Information Center

    Marzano, Robert J.; DiStefano, Philip

    Seven hundred and fifty compositions, randomly selected from National Assessment of Educational Progress essays written by 9-, 13- and 17-year-olds, were analyzed in a study of the skills that go into the writing of a good composition. The essays were first rated as high, medium, or low in quality. A total of 43 different indices reported or…

  10. New matrix polymers for photo-activated resin composites using di-alpha-fluoroacrylic acid derivatives.

    PubMed

    Kurata, Shigeaki; Yamazaki, Noboru

    2008-07-01

    A novel matrix resin for photo-activated resin composites was developed using alpha-fluoroacrylic acid derivatives. To render resin composites with improved mechanical properties, silica fillers were also used. It was found that the newly developed fluorine-substituted monomer was polymerized quite easily not only by free radical chemical initiators, but also by photoirradiation using free radical photoinitiator system. In particular, the photopolymerization rate of the novel monomer was more than two times faster than that of corresponding methacrylate-based monomer. Composite based on the newly developed matrix resin had higher micro-Vickers hardness and compressive strength values than the methacrylate-based composite, and that it contained only trace residual monomers compared with the methacrylate-based material. The high polymerization conversion of the fluorine-substituted monomer could be attributed to the polar effect or the small steric hindrance of fluorine at the alpha-position.

  11. Fatty acid composition of fat depots in wintering Canada geese

    USGS Publications Warehouse

    Austin, J.E.

    1993-01-01

    I determined the fatty acid composition of subcutaneous, abdominal, visceral, and leg saddle depots in adult female Canada Geese (Branta canadensis) wintering in north-central Missouri during October 1984-March 1985. Mean levels of C14:0, C16:0, C16:1, C18:0, C18:1, C18:2, and C18:3 generally were highest in the subcutaneous and abdominal depots. The ratio of saturated to unsaturated fats was highest in the leg saddle depot and lowest in the abdominal depot. I also assessed the differences among sexes, seasons, and years in fatty acid composition of abdominal fat depots in adult geese collected during October-March, 1985-1987. Adult females had consistently higher levels of C14:0 in abdominal depots than males. Fatty acid composition of the abdominal depot differed among years but not by season. In the abdominal depot, C14:0, C16:0, C16:1, and C18:1 were higher in 1986-1987 compared with the previous two years, whereas C18:3 was highest in 1984-1985. Differences among years reflected changes in winter diet. Fatty acids of wintering geese were similar to those previously found in breeding Canada Geese.

  12. Proposition of an Accelerated Ageing Method for Natural Fibre/Polylactic Acid Composite

    NASA Astrophysics Data System (ADS)

    Zandvliet, Clio; Bandyopadhyay, N. R.; Ray, Dipa

    2015-10-01

    Natural fibre composite based on polylactic acid (PLA) composite is of special interest because it is entirely from renewable resources and biodegradable. Some samples of jute/PLA composite and PLA alone made 6 years ago and kept in tropical climate on a shelf shows too fast ageing degradation. In this work, an accelerated ageing method for natural fibres/PLA composite is proposed and tested. Experiment was carried out with jute and flax fibre/PLA composite. The method was compared with the standard ISO 1037-06a. The residual flexural strength after ageing test was compared with the one of common wood-based panels and of real aged samples prepared 6 years ago.

  13. Chemical and isotopic compositions in acid residues from various meteorites

    NASA Technical Reports Server (NTRS)

    Kano, N.; Yamakoshi, K.; Matsuzaki, H.; Nogami, K.

    1993-01-01

    We are planning to carry out systematic isotopic investigations of Ru, Mg, etc., in primordial samples. The investigations will be pursued in the context of a study of the pre-history of the solar system. It is hoped that the study will yield direct evidence for processes of nucleosynthesis in the pre-solar stage and detection of extinct radioactive nuclides. In this paper, we present the results of chemical compositions of acid residues obtained from three types of meteorites: Canyon Diablo (IA), Allende (CV3), and Nuevo Mercuro (H5); and the preliminary results of Ru isotopic compositions.

  14. Alumina-based ceramic composite

    DOEpatents

    Alexander, K.B.; Tiegs, T.N.; Becher, P.F.; Waters, S.B.

    1996-07-23

    An improved ceramic composite comprising oxide ceramic particulates, nonoxide ceramic particulates selected from the group consisting of carbides, borides, nitrides of silicon and transition metals and mixtures thereof, and a ductile binder selected from the group consisting of metallic, intermetallic alloys and mixtures thereof is described. The ceramic composite is made by blending powders of the ceramic particulates and the ductile to form a mixture and consolidating the mixture of under conditions of temperature and pressure sufficient to produce a densified ceramic composite. 5 figs.

  15. Fat deposition, fatty acid composition and meat quality: A review.

    PubMed

    Wood, J D; Enser, M; Fisher, A V; Nute, G R; Sheard, P R; Richardson, R I; Hughes, S I; Whittington, F M

    2008-04-01

    This paper reviews the factors affecting the fatty acid composition of adipose tissue and muscle in pigs, sheep and cattle and shows that a major factor is the total amount of fat. The effects of fatty acid composition on meat quality are also reviewed. Pigs have high levels of polyunsaturated fatty acids (PUFA), including the long chain (C20-22) PUFA in adipose tissue and muscle. The full range of PUFA are also found in sheep adipose tissue and muscle whereas cattle 'conserve' long chain PUFA in muscle phospholipid. Linoleic acid (18:2n-6) is a major ingredient of feeds for all species. Its incorporation into adipose tissue and muscle in relation to the amount in the diet is greater than for other fatty acids. It is deposited in muscle phospholipid at a high level where it and its long chain products eg aracidonic acid (20:4n-6) compete well for insertion into phospholipid molecules. Its proportion in pig adipose tissue declines as fat deposition proceeds and is an index of fatness. The same inverse relationships are not seen in ruminant adipose tissue but in all species the proportion of 18:2n-6 declines in muscle as fat deposition increases. The main reason is that phospholipid, where 18:2n-6 is located, declines as a proportion of muscle lipid and the proportion of neutral lipid, with its higher content of saturated and monounsaturated fatty acids, increases. Oleic acid (18:1cis-9), formed from stearic acid (18:0) by the enzyme stearoyl Co-A desaturase, is a major component of neutral lipid and in ruminants the same enzyme forms conjugated linoleic acid (CLA), an important nutrient in human nutrition. Like 18:2n-6, α-linolenic acid (18:3n-3) is an essential fatty acid and is important to ruminants since it is the major fatty acid in grass. However it does not compete well for insertion into phospholipid compared with 18:2n-6 and its incorporation into adipose tissue and muscle is less efficient. Greater biohydrogenation of 18:3n-3 and a long rumen transit time

  16. Cultural characteristics and fatty acid composition of Corynebacterium acnes.

    PubMed

    Moss, C W; Dowell, V R; Lewis, V J; Schekter, M A

    1967-11-01

    A detailed study of the cultural characteristics and cellular fatty acid composition of 27 isolates of Corynebacterium acnes was performed to establish the properties by which this organism may be identified and characterized. The fatty acids were extracted directly from whole cells and examined as methyl esters by gas-liquid chromatography. Each strain possessed a similar fatty acid profile which was characterized by a large percentage of C15 branched-chain acid. Uniformity in certain biochemical reactions and cultural characteristics was also observed. All strains were catalase-positive, nonmotile, and urease-negative, reduced nitrate, liquefied gelatin, failed to hydrolyze esculin and starch, and gave a positive methyl red test. Glucose, fructose, and glycerol were fermented, but not lactose, salicin, sucrose, maltose, xylose, or arabinose. Production of hydrogen sulfide and indole, fermentation of mannitol, and hemolytic activity were variable characteristics. Two species of the genus Propionibacterium were also tested and found to be similar to C. acnes both in cultural characteristics and fatty acid composition. The results strengthen previous suggestions that C. acnes should be classified in the genus Propionibacterium.

  17. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.

    USGS Publications Warehouse

    Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.; Brown, S.B.

    2009-01-01

    We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.

  18. Amino acid composition, score and in vitro protein digestibility of foods commonly consumed in northwest Mexico.

    PubMed

    Caire-Juvera, Graciela; Vázquez-Ortiz, Francisco A; Grijalva-Haro, Maria I

    2013-01-01

    A better knowledge of the amino acid composition of foods commonly consumed in different regions is essential to calculate their scores and, therefore, to predict their protein quality. This paper presents the amino acid composition, amino acid score and in vitro protein digestibility of fifteen foods that are commonly consumed in Northwest Mexico. The foods were prepared by the traditional methods and were analyzed by reverse-phase HPLC. The chemical score for each food was determined using the recommendations for children of 1-2 years of age, and the digestibility was evaluated using a multienzyme technique. Lysine was the limiting amino acid in cereal-based products (scores 15 to 54), and methionine and cysteine were limiting in legume products (scores 41 to 47), boiled beef (score = 75) and hamburger (score = 82). The method of preparation had an effect on the content of certain amino acids, some of them increased and others decreased their content. Meat products and regional cheese provided a high amino acid score (scores 67 to 91) and digestibility (80.7 to 87.8%). Bologna, a processed meat product, had a lower digestibility (75.4%). Data on the amino acid composition of foods commonly consumed in Mexico can be used to provide valuable information on food analysis and protein quality, and to contribute to nutrition and health research and health programs.

  19. The Acid-Base Titration of a Very Weak Acid: Boric Acid

    ERIC Educational Resources Information Center

    Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.

    2012-01-01

    A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…

  20. A 3D POM–MOF composite based on Ni(ΙΙ) ion and 2,2´-bipyridyl-3,3´-dicarboxylic acid: Crystal structure and proton conductivity

    SciTech Connect

    Wei, Meilin; Wang, Xiaoxiang; Sun, Jingjing; Duan, Xianying

    2013-06-01

    We have succeeded in constructing a 3D POM–MOF, (H[Ni(Hbpdc)(H₂O)₂]₂[PW₁₂O₄₀]·8H₂O)n (H₂bpdc=2,2´-bipyridyl-3,3´-dicarboxylic acid), by the controllable self-assembly of H₂bpdc, Keggin-anions and Ni²⁺ ions based on the electrostatic and coordination interactions. Interestingly, Hbpdc⁻ as polydentate organic ligands and Keggin-anion as polydentate inorganic ligands are covalently linked transition-metal nickel at the same time. The title complex represents a new example of introducing the metal N-heterocyclic multi-carboxylic acid frameworks into POMs chemistry. Based on Keggin-anions being immobilized as part of the metal N-heterocyclic multi-carboxylic acid framework, the title complex realizes four approaches in the 1D hydrophilic channel used to engender proton conductivity in MOFs. Its water adsorption isotherm at room temperature and pressure shows that the water content in it was 31 cm³ g⁻¹ at the maximum allowable humidity, corresponding to 3.7 water molecules per unit formula. It exhibits good proton conductivities (10⁻⁴–10⁻³ S cm⁻¹) at 100 °C in the relative humidity range 35–98%. The corresponding activation energy (E{sub a}) of conductivity was estimated to be 1.01 eV. - Graphical abstract: A POM–MOF composite constructed by Keggin-type polyanion, Ni²⁺ and H₂bpdc shows good proton conductivities of 10⁻⁴–10⁻³ S cm⁻¹ at 100 °C under 35–98% RH. - Highlights: • A POM–MOF was constructed by combining metal N-heterocyclic multi-carboxylic acid framework and Keggin anion. • It opens a pathway for design and synthesis of multifunctional hybrid materials based on two building units. • Three types of potential proton-carriers have been assembled in the 1D hydrophilic channels of the POM–MOF. • It achieved such proton conductivities as 10⁻⁴–10⁻³ S cm⁻¹ at 100 °C in the RH range 35–98%.

  1. Prediction of retention times of proteins in hydrophobic interaction chromatography using only their amino acid composition.

    PubMed

    Salgado, J Cristian; Rapaport, Ivan; Asenjo, Juan A

    2005-12-09

    This paper focuses on the prediction of the dimensionless retention time of proteins (DRT) in hydrophobic interaction chromatography (HIC) by means of mathematical models based, essentially, only on aminoacidic composition. The results show that such prediction is indeed possible. Our main contribution was the design of models that predict the DRT using the minimal information concerning a protein: its aminoacidic composition. The performance is similar to that observed in models that use much more sophisticated information such as the three-dimensional structure of proteins. Three models that, in addition to the amino acid composition, use different assumptions about the amino acids tendency to be exposed to the solvent, were evaluated in 12 proteins with known experimental DRT. In all the cases analyzed, the model that obtained the best results was the one based on a linear estimation of the aminoacidic surface composition. The models were adjusted using a collection of 74 vectors of aminoacidic properties plus a set of 6388 vectors derived from these using two mathematical tools: k-means and self-organizing maps (SOM) algorithms. The best vector was generated by the SOM algorithm and was interpreted as a hydrophobicity scale based partly on the tendency of the amino acids to be hidden in proteins. The prediction error (MSE(JK)) obtained by this model was almost 35% smaller than that obtained by the model that supposes that all the amino acids are completely exposed and 40% smaller than that obtained by the model that uses a simple correction factor considering the general tendency of each amino acid to be exposed to the solvent. In fact, the performance of the best model based on the aminoacidic composition was 5% better than that observed in the model based on the three-dimensional structure of proteins.

  2. Poly(lactic acid)-Based in Situ Microfibrillar Composites with Enhanced Crystallization Kinetics, Mechanical Properties, Rheological Behavior, and Foaming Ability.

    PubMed

    Kakroodi, Adel Ramezani; Kazemi, Yasamin; Ding, WeiDan; Ameli, Aboutaleb; Park, Chul B

    2015-12-14

    Melt blending is one of the most promising techniques for eliminating poly(lactic acid)'s (PLA) numerous drawbacks. However, success in a typical melt blending process is usually achieved through the inclusion of high concentrations of a second polymeric phase which can compromise PLA's green nature. In a pioneering study, we introduce the production of in situ microfibrillar PLA/polyamide-6 (PA6) blends as a cost-effective and efficient technique for improving PLA's properties while minimizing the required PA6 content. Predominantly biobased products, with only 3 wt % of in situ generated PA6 microfibrils (diameter ≈200 nm), were shown to have dramatically improved crystallization kinetics, mechanical properties, melt elasticity and strength, and foaming-ability compared with PLA. Crucially, the microfibrillar blends were produced using an environmentally friendly and cost-effective process. Both of these qualities are essential in guarantying the viability of the proposed technique for overcoming the obstacles associated with the vast commercialization of PLA.

  3. Electrochemical impedance based chiral analysis of anti-ascorbutic drug: l-Ascorbic acid and d-ascorbic acid using C-dots decorated conductive polymer nano-composite electrode.

    PubMed

    Pandey, Indu; Kant, Rama

    2016-03-15

    Clinical manifestations owing to l-ascorbic acid for scurvy as comparison to d-ascorbic acid and challenges of chiral purity are overcome by using chiral selective conductive polymer nanocomposite which mimics antibodies and enzymes. A novel chiral selective imprinted polyaniline-ferrocene-sulfonic acid film has been electrochemically fabricated on C-dots modified pencil graphite electrode. The performance of the obtained l-ascorbic acid or d-ascorbic acid chiral selective sensor was investigated by electrochemical impedance spectroscopy, cyclic and differential pulse voltammetry. The surface characteristics of the C-dots, chiral sensor before and after the de-doping of chiral d- and l-ascorbic acid were characterized by scanning electron microscopy, Raman spectroscopy and X-ray diffraction spectroscopy. Excellent recognition results were obtained by difference in electron transfer resistance. The proposed chiral sensor is capable of measuring d-ascorbic acid or l-ascorbic acid in aqueous as well as in real and commercial samples within the range of 0.020-0.187 nM and 0.003-0.232 nM with detection limit of 0.00073 nM and 0.00016 nM, respectively. The proposed method has also been examined for the chiral selective recognition of ascorbic acid isomers (d- and l-) quantitatively, in complicated matrices of real samples.

  4. Wear Characteristics of Polymer -Based Composites

    NASA Astrophysics Data System (ADS)

    Şahin, Y.; Mirzayev, H.

    2015-11-01

    The dry wear of polytetrafluoroethylene (PTFE)-based composites, including bronze-filled composites (B60), glass-filled composites (G15), and carbon-filled composites (C25), produced by the mold casting method were investigated under different sliding conditions. The Taguchi L27 method and the analysis of variance were used to identify the effect of process parameters on the wear of tested materials. Experimental results showed that the wear resistance of G15 polymer composites was better than those of C25 and B60 ones. The specific wear rate decreased with increasing sliding distance and load, but partly decreased with increasing tensile strength.

  5. Role of surface functionality on the formation of raspberry-like polymer/silica composite particles: Weak acid-base interaction and steric effect

    NASA Astrophysics Data System (ADS)

    Wang, Lan; Song, LinYong; Chao, ZhiYin; Chen, PengPeng; Nie, WangYan; Zhou, YiFeng

    2015-07-01

    The surface functionality of polymer microspheres is the crucial factor to determine the nucleation and growth of silica particles and to construct the organic/inorganic hierarchical structures. The objective of this work was to evaluate the surface functionality and hierarchical morphology relationship via in situ sol-gel reaction. Carboxylic-functionalized poly (styrene-co-maleic anhydride) [P(S-co-MA)], poly(ethylene glycol)-functionalized poly(styrene-co-poly(ethylene glycol) methacrylate) [P(S-co-PEGMA)], and hybrid functionalized poly(styrene-co-maleic anhydride-co-poly(ethylene glycol) methacrylate) [P(S-co-MA-co-PEGMA)] microspheres were synthesized by emulsifier-free polymerization and used as templates. The morphologies of the composite particles were observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results showed that core-shell structure was obtained with P(S-co-MA) as templates; raspberry-like structure was observed by using P(S-co-MA-co-PEGMA) as templates; and no silica particles were attached onto the surface of P(S-co-PEGMA) microspheres. These results indicated that the carboxylic groups on the surface formed by hydrolysis of anhydride groups were the determinate factor to control the nucleation of silica nanoparticles, and the PEG chains on the surface can affect the growth of silica particles. In addition, the particulate films were constructed by assembling these composite particles on glass substrates and modified with dodecyltrichlorosilane, the contact angles of water on the dual-sized structured surface were up to 160°.

  6. Neonatal jaundice and fatty acid composition of the maternal diet.

    PubMed

    Uhari, M; Alkku, A; Nikkari, T; Timonen, E

    1985-11-01

    The role of serum fatty acid composition in neonatal jaundice was studied by comparing the incidence of jaundice among 332 newborn infants receiving breast milk from mothers on a diet with either a low (0.1, n = 145) or a high (1.5, n = 187) polyunsaturated to saturated fatty acid (P/S) ratio. The diet was started immediately after delivery. The composition of fatty acids in the breast milk and sera of the mothers and in the sera of the newborns was evaluated from a random sample of 15 mother-newborn pairs on the control diet (low P/S ratio) and 19 pairs on the experimental diet. Five days after delivery the relative amounts of fatty acids, especially that of linoleate, in the sera of the mothers differed significantly depending on the diet. Differences were also observed in breast milk samples taken three, four or five days after delivery and in the sera of the newborns sampled at the age of four or five days. Nine of the 145 newborn infants (6.2%) in the control group had to be treated with light therapy compared with 12 out of 187 (6.4%) of the newborn infants in the experimental group (high P/S ratio). Serum bilirubin concentrations were 142.5 mumol/l (SD 65.8) and 140.7 mumol/l (SD 73.5) in the experimental and control groups, respectively, at the age of five days. It appears that the changes in the composition of serum fatty acids reached in this study had no effect on the neonatal jaundice.

  7. Photocurable bioadhesive based on lactic acid.

    PubMed

    Marques, D S; Santos, J M C; Ferreira, P; Correia, T R; Correia, I J; Gil, M H; Baptista, C M S G

    2016-01-01

    Novel photocurable and low molecular weight oligomers based on l-lactic acid with proven interest to be used as bioadhesive were successfully manufactured. Preparation of lactic acid oligomers with methacrylic end functionalizations was carried out in the absence of catalyst or solvents by self-esterification in two reaction steps: telechelic lactic acid oligomerization with OH end groups and further functionalization with methacrylic anhydride. The final adhesive composition was achieved by the addition of a reported biocompatible photoinitiator (Irgacure® 2959). Preliminary in vitro biodegradability was investigated by hydrolytic degradation in PBS (pH=7.4) at 37 °C. The adhesion performance was evaluated using glued aminated substrates (gelatine pieces) subjected to pull-to-break test. Surface energy measured by contact angles is lower than the reported values of the skin and blood. The absence of cytoxicity was evaluated using human fibroblasts. A notable antimicrobial behaviour was observed using two bacterial models (Staphylococcus aureus and Escherichia coli). The cured material exhibited a strong thrombogenic character when placed in contact with blood, which can be predicted as a haemostatic effect for bleeding control. This novel material was subjected to an extensive characterization showing great potential for bioadhesive or other biomedical applications where biodegradable and biocompatible photocurable materials are required.

  8. Postnatal changes in fatty acids composition of brown adipose tissue

    NASA Astrophysics Data System (ADS)

    Ohno, T.; Ogawa, K.; Kuroshima, A.

    1992-03-01

    It has been demonstrated that thermogenic activity of brown adipose tissue (BAT) is higher during the early postnatal period, decreasing towards a low adult level. The present study examined postnatal changes in the lipid composition of BAT. BAT from pre-weaning rats at 4 and 14 days old showed the following differences in lipid composition compared to that from adults of 12 weeks old. (i) Relative weight of interscapular BAT to body weight was markedly greater. (ii) BAT-triglyceride (TG) level was lower, while BAT-phospholipid (PL)level was higher. (iii) In TG fatty acids (FA) polyunsaturated fatty acids (PU; mol %), arachidonate index (AI), unsaturation index (UI) and PU/saturated FA (SA) were higher; rare FA such as eicosadienoate, bishomo- γ-linolenic acid and lignoceric acid in mol % were also higher. (iv) In PL-FA monounsaturated FA (MU) in mol % was lower; PU mol %, AI and UI were higher. These features in BAT of pre-weaning rats resembled those in the cold-acclimated adults, suggesting a close relationship of the PL-FA profile to high activity of BAT.

  9. Thermophysical properties of starch and whey protein composite prepared in presence of organic acid and esters

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previously, we prepared starch and protein composite by reactive mixing in presence of various organic acids and found that use of these acid esters resulted in composites with good mechanical properties. In this study, concentration (% w/w) of acid citrates in the starch-protein composites were var...

  10. Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition

    PubMed Central

    Mahanty, Arabinda; Sankar, T. V.; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md.; Debnath, Dipesh; Vijayagopal, P.; Sridhar, N.; Akhtar, M. S.; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Das, Debajeet; Das, Pushpita; Vijayan, K. K.; Laxmanan, P. T.; Sharma, A. P.

    2014-01-01

    Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs. PMID:25379285

  11. Amino Acid compositions of 27 food fishes and their importance in clinical nutrition.

    PubMed

    Mohanty, Bimal; Mahanty, Arabinda; Ganguly, Satabdi; Sankar, T V; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md; Debnath, Dipesh; Vijayagopal, P; Sridhar, N; Akhtar, M S; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Paria, Prasenjit; Das, Debajeet; Das, Pushpita; Vijayan, K K; Laxmanan, P T; Sharma, A P

    2014-01-01

    Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs.

  12. Electrochemiluminescence sensor for melamine based on a Ru(bpy)₃²⁺-doped silica nanoparticles/carboxylic acid functionalized multi-walled carbon nanotubes/Nafion composite film modified electrode.

    PubMed

    Chen, Xiaomei; Lian, Sai; Ma, Ying; Peng, Aihong; Tian, Xiaotian; Huang, Zhiyong; Chen, Xi

    2016-01-01

    In this work, a sensitive electrochemiluminescence (ECL) sensor for the determination of melamine (MEL) was developed based on a Ru(bpy)3(2+)-doped silica nanoparticles (RUDS)/carboxylic acid functionalized multi-walled carbon nanotubes (CMWCNTs)/Nafion composite film modified electrode. The homogeneous spherical RUDS were synthesized by a reverse microemulsion method. As Ru(bpy)3(2+) were encapsulated in the RUDS, Ru(bpy)3(2+) dropping from the modified electrode can be greatly prevented, which is helpful for obtaining a stable ECL signal. Moreover, to improve the conductivity of the film and promote the electron transfer rate on electrode surface, CMWCNTs with excellent electrical conductivity and large surface area were applied in the construction of the sensing film. As CMWCNTs acted as electron bridges making more Ru(bpy)3(2+) participate in the reaction, the ECL intensity was greatly enhanced. Under the optimum conditions, the relative ECL signal (△IECL) was proportional to the logarithmic MEL concentration ranging from 5×10(-13) to 1×10(-7) mol L(-1) with a detection limit of 1×10(-13) mol L(-1). To verify the reliability, the thus-fabricated ECL sensor was applied to determine the concentration of MEL in milk. Based on these investigations, the proposed ECL sensor exhibited good feasibility and high sensitivity for the determination of MEL, promising the applicability of this sensor in practical analysis.

  13. Concentration of Nitric Acid Strongly Influences Chemical Composition of Graphite Oxide.

    PubMed

    Jankovsky, Ondrej; Novacek, Michal; Luxa, Jan; Sedmidubsky, David; Bohacova, Marie; Pumera, Martin; Sofer, Zdenek

    2017-02-28

    Graphite oxide is the most widely used precursor for the synthesis of graphene by top-down methods. We demonstrate a significant influence of nitric acid concentration on the structure and composition of the graphite oxide prepared by graphite oxidation. In general, two main chlorate based oxidation methods are currently used for graphite oxide synthesis, Staudenmaier method dealing with 98 wt.% nitric acid and Hofmann method dealing with 68 wt.% nitric acid. However a gradual change of nitric acid concentration allowed for the continuous change of the graphite oxide composition. The prepared samples were thoroughly characterized by microscopic techniques as well as various spectroscopic and analytical methods. Lowering of nitric acid concentration led to an increase of oxidation degree and in particular to a concentration of epoxy and hydroxyl groups. This knowledge is not only useful for the large scale synthesis of graphite oxide with tunable size and chemical composition, but the use of nitric acid in lower concentration can also significantly reduce the overall cost of the synthesis.

  14. Polymer gel dosimeter based on itaconic acid.

    PubMed

    Mattea, Facundo; Chacón, David; Vedelago, José; Valente, Mauro; Strumia, Miriam C

    2015-11-01

    A new polymeric dosimeter based on itaconic acid and N, N'-methylenebisacrylamide was studied. The preparation method, compositions of monomer and crosslinking agent and the presence of oxygen in the dosimetric system were analyzed. The resulting materials were irradiated with an X-ray tube at 158cGy/min, 226cGymin and 298cGy/min with doses up to 1000Gy. The dosimeters presented a linear response in the dose range 75-1000Gy, sensitivities of 0.037 1/Gyat 298cGy/min and an increase in the sensitivity with lower dose rates. One of the most relevant outcomes in this study was obtaining different monomer to crosslinker inclusion in the formed gel for the dosimeters where oxygen was purged during the preparation method. This effect has not been reported in other typical dosimeters and could be attributed to the large differences in the reactivity among these species.

  15. Thermal properties of extruded injection-molded poly (lactic acid) and milkweed composites: degradation kinetics and enthalpic relaxation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Currently, most polymer composites utilize petroleum-based materials that are non-degradable and difficult to recycle or incur substantial cost for disposal. Green composites can be used in nondurable limited applications. In order to determine the degree of compatibility between Poly (lactic Acid...

  16. Estimating Decision Indices Based on Composite Scores

    ERIC Educational Resources Information Center

    Knupp, Tawnya Lee

    2009-01-01

    The purpose of this study was to develop an IRT model that would enable the estimation of decision indices based on composite scores. The composite scores, defined as a combination of unidimensional test scores, were either a total raw score or an average scale score. Additionally, estimation methods for the normal and compound multinomial models…

  17. Amino Acid Composition of Breast Milk from Urban Chinese Mothers

    PubMed Central

    Garcia-Rodenas, Clara L.; Affolter, Michael; Vinyes-Pares, Gerard; De Castro, Carlos A.; Karagounis, Leonidas G.; Zhang, Yumei; Wang, Peiyu; Thakkar, Sagar K.

    2016-01-01

    Human breast milk (BM) amino acid (AA) composition may be impacted by lactation stage or factors related to geographical location. The present cross-sectional study is aimed at assessing the temporal changes of BMAA over lactation stages in a large cohort of urban mothers in China. Four hundred fifty BM samples, collected in three Chinese cities covering eight months of lactation were analyzed for free (FAA) and total (TAA) AA by o-phthalaldehyde/ fluorenylmethylchloroformate (OPA/FMOC) derivatization. Concentrations and changes over lactation were aligned with previous reports. Both the sum and the individual TAA values significantly decreased during the first periods of lactation and then generally leveled off. Leucine and methionine were respectively the most and the least abundant indispensable amino acids across all the lactation stages, whereas glutamic acid + glutamine (Glx) was the most and cystine the least abundant dispensable AA. The contribution of FAA to TAA levels was less than 2%, except for free Glx, which was the most abundant FAA. In conclusion, the AA composition of the milk from our cohort of urban Chinese mothers was comparable to previous studies conducted in other parts of the world, suggesting that this is an evolutionary conserved trait largely independent of geographical, ethnic, or dietary factors. PMID:27690094

  18. Relationship between cannabinoids content and composition of fatty acids in hempseed oils.

    PubMed

    Petrović, Marinko; Debeljak, Željko; Kezić, Nataša; Džidara, Petra

    2015-03-01

    Hempseed oils acquired on the Croatian markets were characterised by cannabinoid content and fatty acid composition. The new method for determination of cannabinoid content was developed and validated in the range of 0.05-60 mg/kg, and the content of tetrahydrocannabinol varied between 3.23 and 69.5 mg/kg. Large differences among the samples were obtained for phenotype ratio suggesting that not all of analysed hempseed oils were produced from industrial hemp. Sample clustering based on cannabinoid content assigned samples to two groups closely related to the phenotype ratios obtained. The results of this study confirm that hempseed oil is a good source of polyunsaturated fatty acids, especially γ-linolenic and stearidonic acid, but the content varies a lot more than the omega-6/omega-3 ratio. The grouping of samples on fatty acid content assigned samples to two groups which were consistent with the groups obtained based on cannabinoid content clustering.

  19. Conducting polyheterocycle composites based on porous hosts

    NASA Astrophysics Data System (ADS)

    Park, J. S.; Ruckenstein, E.

    1992-02-01

    Conducting composites based on porous substrates (cotton fiber, non-woven polypropylene mat and porous crosslinked polystyrene) have been prepared by a two step imbibition technique. First, the substrate was imbibed with a solution of monomer (pyrrole or bithiophene) in acetonitrile, followed by partial drying. Subsequently, the substrate was again imbibed, this time with an oxidant dissolved in a suitable solvent. The polymerization of the monomer inside the host in the presence of the oxidant and the doping of the polymer with the oxidant leads to the conducting composite. The highly hydrophobic and porous crosslinked polystyrene, prepared by the concentrated emulsion polymerization method, is the most efficient. The solvent employed for the oxidant plays a major role. A FeCl3-methanol system and porous crosslinked polystyrene lead to conductivities of polythiophene and polypyrrole based composites of 3.63 and 0.65 S/cm, respectively. Copper perchlorate and iron perchlorate are also suitable oxidants. The environmental and thermal stabilities of polypyrrole based composites are lower than those of polythiophene based composites. The thermal stability of polypyrrole based composites can be enhanced by including a small amount of an organic antioxidant, such as amides or substituted phenols, in the composite.

  20. Variations in fatty acid composition of neem seeds collected from the Rajasthan state of India.

    PubMed

    Kaushik, N; Vir, S

    2000-12-01

    Neem (Azadirachta indica) is a multipurpose tree native to the Indian subcontinent and South-East Asian countries. Products derived from neem have been used for centuries, particularly in India, for medicinal and pest-management purposes. Azadirachtin and neem oil are the two major commercially important products derived from the tree. The oil contains palmitic, stearic, oleic and linoleic acids in good proportion. Although there is growing demand for quality planting material for plantation of neem, efforts are lacking for the selection of neem trees based on their biochemical composition. In the present study, 60 Neem seed samples were collected from different provinances of the Rajasthan state in India. These samples were analysed by GLC to study the variability of fatty acid composition. Significant variability in individual fatty acids was observed. The palmitic acid ranged from 16 to 34%, stearic acid from 6 to 24%, oleic acid from 25 to 58% and linoleic acid from 6 to 17%. This variability can be exploited for selection of trees and for studying the genetic variability in neem. These selections can also be utilized for genetic improvement of the tree.

  1. Processing and characterization of bio-based composites

    NASA Astrophysics Data System (ADS)

    Lu, Hong

    Much research has focused on bio-based composites as a potential material to replace petroleum-based plastics. Considering the high price of Polyhydroxyalkanoates (PHAs), PHA/ Distiller's Dried Grains with Solubles (DDGS) composite is a promising economical and high-performance biodegradable material. In this paper, we discuss the effect of DDGS on PHA composites in balancing cost with material performance. Poly (lactic acid) PLA/DDGS composite is another excellent biodegradable composite, although as a bio-based polymer its degradation time is relatively long. The goal of this research is therefore to accelerate the degradation process for this material. Both bio-based composites were extruded through a twin-screw microcompounder, and the two materials were uniformly mixed. The morphology of the samples was examined using a Scanning Electron Microscope (SEM); thermal stability was determined with a Thermal Gravimetric Analyzer (TGA); other thermal properties were studied using Differential Scanning Calorimetry (DSC) and a Dynamic Mechanical Analyzer (DMA). Viscoelastic properties were also evaluated using a Rheometer.

  2. Tetraethyl orthosilicate-based glass composition and method

    DOEpatents

    Wicks, G.G.; Livingston, R.R.; Baylor, L.C.; Whitaker, M.J.; O`Rourke, P.E.

    1997-06-10

    A tetraethyl orthosilicate-based, sol-gel glass composition with additives selected for various applications is described. The composition is made by mixing ethanol, water, and tetraethyl orthosilicate, adjusting the pH into the acid range, and aging the mixture at room temperature. The additives, such as an optical indicator, filler, or catalyst, are then added to the mixture to form the composition which can be applied to a substrate before curing. If the additive is an indicator, the light-absorbing characteristics of which vary upon contact with a particular analyte, the indicator can be applied to a lens, optical fiber, reagent strip, or flow cell for use in chemical analysis. Alternatively, an additive such as alumina particles is blended into the mixture to form a filler composition for patching cracks in metal, glass, or ceramic piping. 12 figs.

  3. Tetraethyl orthosilicate-based glass composition and method

    DOEpatents

    Wicks, George G.; Livingston, Ronald R.; Baylor, Lewis C.; Whitaker, Michael J.; O'Rourke, Patrick E.

    1997-01-01

    A tetraethyl orthosilicate-based, sol-gel glass composition with additives selected for various applications. The composition is made by mixing ethanol, water, and tetraethyl orthosilicate, adjusting the pH into the acid range, and aging the mixture at room temperature. The additives, such as an optical indicator, filler, or catalyst, are then added to the mixture to form the composition which can be applied to a substrate before curing. If the additive is an indicator, the light-absorbing characteristics of which vary upon contact with a particular analyte, the indicator can be applied to a lens, optical fiber, reagant strip, or flow cell for use in chemical analysis. Alternatively, an additive such as alumina particles is blended into the mixture to form a filler composition for patching cracks in metal, glass, or ceramic piping.

  4. Acid gas scrubbing by composite solvent-swollen membranes

    DOEpatents

    Matson, S.L.; Lee, E.K.L.; Friesen, D.T.; Kelly, D.J.

    1988-04-12

    A composite immobilized liquid membrane suitable for acid gas scrubbing is disclosed. The membrane is a solvent-swollen polymer and a microporous polymeric support, the solvent being selected from a class of highly polar solvents containing at least one atom selected from nitrogen, oxygen, phosphorus and sulfur, and having a boiling point of at least 100 C and a solubility parameter of from about 7.5 to about 13.5 (cal/cm[sup 3]-atm)[sup 1/2]. Such solvents are homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. Also disclosed are methods of acid gas scrubbing of high- and low-Btu gas effluents with such solvent-swollen membranes. 3 figs.

  5. Acid gas scrubbing by composite solvent-swollen membranes

    DOEpatents

    Matson, Stephen L.; Lee, Eric K. L.; Friesen, Dwayne T.; Kelly, Donald J.

    1988-01-01

    A composite immobilized liquid membrane suitable for acid gas scrubbing is disclosed. The membrane is a solvent-swollen polymer and a microporous polymeric support, the solvent being selected from a class of highly polar solvents containing at least one atom selected from nitrogen, oxygen, phosphorous and sulfur, and having a boiling point of at least 100.degree. C. and a solubility parameter of from about 7.5 to about 13.5 (cal/cm.sup.3 -atm).sup.1/2. Such solvents are homogeneously distributed through the solvent-swollen polymer from 20% to 95% by weight. Also disclosed are methods of acid gas scrubbing of high- and low-Btu gas effluents with such solvent-swollen membranes.

  6. Detailed Dimethylacetal and Fatty Acid Composition of Rumen Content from Lambs Fed Lucerne or Concentrate Supplemented with Soybean Oil

    PubMed Central

    Alves, Susana P.; Santos-Silva, José; Cabrita, Ana R. J.; Fonseca, António J. M.; Bessa, Rui J. B.

    2013-01-01

    Lipid metabolism in the rumen is responsible for the complex fatty acid profile of rumen outflow compared with the dietary fatty acid composition, contributing to the lipid profile of ruminant products. A method for the detailed dimethylacetal and fatty acid analysis of rumen contents was developed and applied to rumen content collected from lambs fed lucerne or concentrate based diets supplemented with soybean oil. The methodological approach developed consisted on a basic/acid direct transesterification followed by thin-layer chromatography to isolate fatty acid methyl esters from dimethylacetal, oxo- fatty acid and fatty acid dimethylesters. The dimethylacetal composition was quite similar to the fatty acid composition, presenting even-, odd- and branched-chain structures. Total and individual odd- and branched-chain dimethylacetals were mostly affected by basal diet. The presence of 18∶1 dimethylacetals indicates that biohydrogenation intermediates might be incorporated in structural microbial lipids. Moreover, medium-chain fatty acid dimethylesters were identified for the first time in the rumen content despite their concentration being relatively low. The fatty acids containing 18 carbon-chain lengths comprise the majority of the fatty acids present in the rumen content, most of them being biohydrogenation intermediates of 18∶2n−6 and 18∶3n−3. Additionally, three oxo- fatty acids were identified in rumen samples, and 16-O-18∶0 might be produced during biohydrogenation of the 18∶3n−3. PMID:23484024

  7. Influence of fatty acid composition of raw materials on biodiesel properties.

    PubMed

    Ramos, María Jesús; Fernández, Carmen María; Casas, Abraham; Rodríguez, Lourdes; Pérez, Angel

    2009-01-01

    The aim of this work was the study of the influence of the raw material composition on biodiesel quality, using a transesterification reaction. Thus, ten refined vegetable oils were transesterificated using potassium methoxide as catalyst and standard reaction conditions (reaction time, 1h; weight of catalyst, 1 wt.% of initial oil weight; molar ratio methanol/oil, 6/1; reaction temperature, 60 degrees C). Biodiesel quality was tested according to the standard [UNE-EN 14214, 2003. Automotive fuels. Fatty acid methyl esters (FAME) for diesel engines. Requirements and test methods]. Some critical parameters like oxidation stability, cetane number, iodine value and cold filter plugging point were correlated with the methyl ester composition of each biodiesel, according to two parameters: degree of unsaturation and long chain saturated factor. Finally, a triangular graph based on the composition in monounsaturated, polyunsaturated and saturated methyl esters was built in order to predict the critical parameters of European standard for whatever biodiesel, known its composition.

  8. Preparation and swelling properties of pH-sensitive composite hydrogel beads based on chitosan-g-poly (acrylic acid)/vermiculite and sodium alginate for diclofenac controlled release.

    PubMed

    Wang, Qin; Xie, Xiaoling; Zhang, Xiaowei; Zhang, Junping; Wang, Aiqin

    2010-04-01

    A series of pH-sensitive composite hydrogel beads, chitosan-g-poly (acrylic acid)/vermiculite/sodium alginate (CTS-g-PAA/VMT/SA), was prepared using CTS-g-PAA/VMT composite and SA by Ca(2+) as the crosslinking agent. The structure and morphologies of the developed composite hydrogel beads were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. The swelling properties and pH-sensitivity of the beads were investigated. In addition, the drug loading and controlled release behaviors of the beads were also evaluated using diclofenac sodium (DS) as the model drug in stimulated gastric fluids (pH 2.1) and intestinal fluids (pH 6.8). The results indicate that the composite hydrogel beads showed good pH-sensitivity. The release rate of the drug from the composite hydrogel beads is remarkably slowed down, which indicated that incorporating VMT into the composite hydrogel beads can improve the burst release effect of the drug.

  9. Evaluation of fatty acid and amino acid compositions in okra (Abelmoschus esculentus) grown in different geographical locations.

    PubMed

    Sami, Rokayya; Lianzhou, Jiang; Yang, Li; Ma, Ying; Jing, Jing

    2013-01-01

    Okra has different uses as a food and a remedy in traditional medicine. Since it produces many seeds, distribution of the plant is also quite easy. Although seed oil yield is low (4.7%), since the linoleic acid composition of the seed oil is quiet high (67.5%), it can still be used as a source of (UNSAT) unsaturated fatty acids. In this study, samples of okra grown in four different locations were analyzed to measure fatty acid and amino acid compositions. The content of the lipid extraction ranged from 4.34% to 4.52% on a dry weight basis. Quantitatively, the main okra fatty acids were palmitic acid (29.18-43.26%), linoleic acid (32.22-43.07%), linolenic acid (6.79-12.34%), stearic acid (6.36-7.73%), oleic acid (4.31-6.98%), arachidic acid (ND-3.48%), margaric acid (1.44-2.16%), pentadecylic acid (0.63-0.92%), and myristic acid (0.21-0.49%). Aspartic acid, proline, and glutamic acids were the main amino acids in okra pods, while cysteine and tyrosine were the minor amino acids. Statistical methods revealed how the fatty acid and amino acid contents in okra may be affected by the sampling location.

  10. Changes in fatty acid composition of Chlorella vulgaris by hypochlorous acid.

    PubMed

    Park, Ji-Yeon; Choi, Sun-A; Jeong, Min-Ji; Nam, Bora; Oh, You-Kwan; Lee, Jin-Suk

    2014-06-01

    Hypochlorous acid treatment of a microalga, Chlorella vulgaris, was investigated to improve the quality of microalgal lipid and to obtain high biodiesel-conversion yield. Because chlorophyll deactivates the catalyst for biodiesel conversion, its removal in the lipid-extraction step enhances biodiesel productivity. When microalgae contacted the hypochlorous acid, chlorophyll was removed, and resultant changes in fatty acid composition of microalgal lipid were observed. The lipid-extraction yield after activated clay treatment was 32.7 mg lipid/g cell; after NaClO treatment at 0.8% available chlorine concentration, it was 95.2 mg lipid/g cell; and after NaCl electrolysis treatment at the 1 g/L cell concentration, it was 102.4 mg lipid/g cell. While the contents of all of the unsaturated fatty acids except oleic acid, in the microalgal lipid, decreased as the result of NaClO treatment, the contents of all of the unsaturated fatty acids including oleic acid decreased as the result of NaCl electrolysis treatment.

  11. Base deflection and microleakage of composite restorations.

    PubMed

    Paulillo, L A; de Goes, M F; Consani, S

    1994-06-01

    The flexural deflections of human dentin, Herculite XR, Dycal, Vidrion F, zinc phosphate base, and combinations of composite-base were determined. The influence of the flexural deflections in the marginal microleakage was also determined for the composite-base combinations. The flexural deflection test for dentin showed no statistically significant differences between the two floor cavity depths studied. There were significant differences among cements when the thickness of the base was 1 mm whereas no differences occurred at 2 mm. The composite-base combinations did not present statistical differences. There were no statistically significant differences in the microleakage levels among loaded and non-loaded specimens; however, dye penetration was visually greater in loaded samples.

  12. New type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane for gallic acid encapsulation and controlled release.

    PubMed

    Paun, Gabriela; Neagu, Elena; Tache, Andreia; Radu, G L

    2014-01-01

    A new type of chitosan/2-hydroxypropyl-β-cyclodextrin composite membrane have been developed for the encapsulation and controlled release of gallic acid. The morphology of the composite membrane was investigated by infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM), whereas swelling gallic acid and release properties were investigated by UV-visible spectroscopy. The release behavior with pH changes was also explored. The composite membrane based on chitosan/2-hydroxypropyl-β-cyclodextrin with gallic acid included showed improved antioxidant capacities compared to plain chitosan membrane. The information obtained in this study will facilitate the design and preparation of composite membrane based on chitosan and could open a wide range of applications, particularly its use as an antioxidant in food, food packaging, biomedical (biodegradable soft porous scaffolds for enhance the surrounding tissue regeneration), pharmaceutical and cosmetics industries.

  13. Physical and sensory properties of dairy products from cows with various milk fatty acid compositions.

    PubMed

    Chen, She; Bobe, Gerd; Zimmerman, Shelly; Hammond, Earl G; Luhman, Cindie M; Boylston, Terri D; Freeman, Albert E; Beitz, Donald C

    2004-06-02

    Dairy products from milk of cows fed diets rich in polyunsaturated fatty acids have a more health-promoting fatty acid composition and are softer but often have oxidized flavors. Dairy products made from cow's milk that has more- or less-unsaturated fatty acid compositions were tested for differences in texture and flavor from those made from bulk-tank milk. The milk was manufactured into butter, vanilla ice cream, yogurt, Provolone cheese, and Cheddar cheese. The products were analyzed for fatty acid composition, physical properties, and flavor. Milk of cows with a more monounsaturated fatty acid composition yielded products with a more monounsaturated fatty acid composition that were softer and had a satisfactory flavor. Thus, selection of cows for milk fatty acid composition can be used to produce dairy products that are probably more healthful and have a softer texture.

  14. Stratification, composition, and function of marine mammal blubber: the ecology of fatty acids in marine mammals.

    PubMed

    Strandberg, Ursula; Käkelä, Anne; Lydersen, Christian; Kovacs, Kit M; Grahl-Nielsen, Otto; Hyvärinen, Heikki; Käkelä, Reijo

    2008-01-01

    Abstract This study of vertical fatty acid profiles, based on analysis of 58 fatty acids sampled at 3-mm intervals throughout the blubber column of a model marine mammal, the ringed seal (Pusa hispida), revealed three chemically distinct layers. The average depths of the outer and inner layers were quite consistent (approximately 1.5 and approximately 1 cm, respectively). Consequently, the middle layer varied greatly in thickness, from being virtually absent in the thinnest animals to 2.5 cm thick in the fattest. The relative consistencies of the thickness and composition of the layers as well as the nature of the fatty acids making up each layer support the generally assumed function of the various layers: (1) the outer layer is primarily structural and thermoregulatory, (2) the inner layer is metabolically active with a fatty acid composition that is strongly affected by recent/ongoing lipid mobilization/deposition, and (3) the middle layer is a storage site that contracts and expands with food availability/consumption. The remarkable dynamics of the middle layer along with the discrete pattern of stratification found in the vertical fatty acid profiles have important implications for methodological sampling design for studies of foraging ecology and toxicology based on analyses of blubber of marine mammals.

  15. High-capacity composite adsorbents for nucleic acids.

    PubMed

    Tiainen, Peter; Rokebul Anower, M; Larsson, Per-Olof

    2011-08-05

    Cytopore™ is a bead-shaped, macroporous and easily compressible cellulose-based anion-exchange material intended for cultivation of anchor-dependent animal cells. Reticulated vitreous carbon (RVC) is a strong, non-compressible, high voidage (97%) matrix material that can be cut to desired geometrical shapes. Cytopore and RVC were combined to cylindrical composites (25 mm × 10 mm) fitted inside chromatography columns. The composite combined the advantageous properties of both its constituents, making it suitable for column chromatography. The composite could withstand very high flow rates without compaction of the bed (>25 column volumes/min; 4000 cm h(-1)). Chromatography runs with tracers showed a low HETP value (0.3mm), suggesting that pore flow was in operation. The dynamic binding capacities (10% breakthrough) per gram of dry weight Cytopore were determined for several compounds including DNA and RNA and were found to be 240-370 mg/g. The composite was used to isolate pUC 18-type plasmids from a cleared alkaline lysate in a good yield. Confocal microscopy studies showed that plasmids were bound not only to the surface of the Cytopore material but also within the matrix walls, thus offering an explanation to the very high binding capacities observed. The concept of using a composite prepared from a mechanically weak, high-binding material and a strong scaffold material may be applied to other systems as well.

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

    DTIC Science & Technology

    2008-12-01

    Protection Agency, 2003: National Emission Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production, Federal Register, 68...G.R., 2007: Fatty acid-based vinyl ester composites with low hazardous air pollutant contents, J. of BioBased Matl. and BioEnergy, 1, 409-416

  17. Effects of 35% corn wet distillers grains plus solubles in steam-flaked and dry-rolled corn-based finishing diets on animal performance, carcass characteristics, beef fatty acid composition, and sensory attributes.

    PubMed

    Buttrey, E K; Jenkins, K H; Lewis, J B; Smith, S B; Miller, R K; Lawrence, T E; McCollum, F T; Pinedo, P J; Cole, N A; MacDonald, J C

    2013-04-01

    Fifty-four individually-fed Hereford-Angus cross steers (initial BW = 308 ± 9 kg) were used in an unbalanced randomized block design with a 2 × 2 factorial treatment arrangement to determine effects of corn processing method and corn wet distillers grains plus solubles (WDGS) inclusion in finishing diets on animal performance, carcass and beef characteristics, and sensory attributes. Dietary treatments included steam-flaked corn- (SFC) and dry-rolled corn (DRC)-based finishing diets containing 0 or 35% WDGS (DM basis; 0SFC and 35SFC, 0DRC and 35DRC, respectively). Yellow grease was used to equilibrate fat content of diets. Steers were fed 174 d, and were harvested on a single date when the mean ultrasound fat thickness was estimated to be 1.30 cm. No interactions between corn processing and WDGS were observed for performance or carcass characteristics (P ≥ 0.11). Final BW (556 ± 14 kg) and ADG (1.43 ± 0.06 kg) were not affected (P ≥ 0.25) by dietary treatment. Steers fed SFC-based diets consumed less feed, and were 10.6% more efficient (P < 0.01) than those fed DRC-based diets. Including WDGS in finishing diets improved feed efficiency of steers consuming both SFC- and DRC-based diets (P ≤ 0.04). Dietary treatment did not affect HCW, dressing percentage, fat thickness, or yield grade (P ≥ 0.27). Including WDGS in finishing diets decreased the concentration of 16:1cis-9, 18:1cis-9, and 18:1cis-11 fatty acids, and tended (P ≤ 0.10) to increase total fat concentration of steaks compared with diets without WDGS. A corn processing method by WDGS interaction was detected for 18:1trans-11 where steaks from 0DRC diets had decreased concentrations compared with other diets. There were no dietary effects on palatability attributes (P > 0.20). Livery-organy aromatics (P = 0.03) and sweet basic tastes (P = 0.01) in steaks from the 35SFC treatment were more intense than in other treatments, but were barely detectable. Thiobarbituric acid reactive substances tended

  18. [Prediction of lipases types by different scale pseudo-amino acid composition].

    PubMed

    Zhang, Guangya; Li, Hongchun; Gao, Jiaqiang; Fang, Baishan

    2008-11-01

    Lipases are widely used enzymes in biotechnology. Although they catalyze the same reaction, their sequences vary. Therefore, it is highly desired to develop a fast and reliable method to identify the types of lipases according to their sequences, or even just to confirm whether they are lipases or not. By proposing two scales based pseudo amino acid composition approaches to extract the features of the sequences, a powerful predictor based on k-nearest neighbor was introduced to address the problems. The overall success rates thus obtained by the 10-fold cross-validation test were shown as below: for predicting lipases and nonlipase, the success rates were 92.8%, 91.4% and 91.3%, respectively. For lipase types, the success rates were 92.3%, 90.3% and 89.7%, respectively. Among them, the Z scales based pseudo amino acid composition was the best, T scales was the second. They outperformed significantly than 6 other frequently used sequence feature extraction methods. The high success rates yielded for such a stringent dataset indicate predicting the types of lipases is feasible and the different scales pseudo amino acid composition might be a useful tool for extracting the features of protein sequences, or at lease can play a complementary role to many of the other existing approaches.

  19. Tantalum-Based Ceramics for Refractory Composites

    NASA Technical Reports Server (NTRS)

    Stewart, David A.; Leiser, Daniel; DiFiore, Robert; Kalvala, Victor

    2006-01-01

    A family of tantalum-based ceramics has been invented as ingredients of high-temperature composite insulating tiles. These materials are suitable for coating and/or permeating the outer layers of rigid porous (foam-like or fibrous) ceramic substrates to (1) render the resulting composite ceramic tiles impervious to hot gases and (2) enable the tiles to survive high heat fluxes at temperatures that can exceed 3,000 F ( 1,600 C).

  20. Magnesium Based Composite via Friction Stir Processing

    DTIC Science & Technology

    2013-04-01

    process developed by Mishra et.al [8] based on the principles of friction stir welding ( FSW ) is getting increased attention. It involves the traverse...compared to other thermomechanical processes [9]. Mishra et al. [10] have used FSP to fabricate a surface composite with SiC particulates in aluminum ...This work was followed by other reports of composite fabrication in aluminum alloys with various reinforcements, like Al3Ti, Al2Cu, Al2O3

  1. Fatty acid composition of seeds of some species of Nepeta L.

    PubMed

    Kiliç, Turgut; Dirmenci, Tuncay; Gören, Ahmet C

    2007-05-01

    The fatty acid compositions of Nepeta viscida, N. cilicica, N. crinita, N. nuda ssp. glandulifera and N. aristata were analyzed by GC/MS. The main free fatty acids were found as linolenic acid (49.8-58.5%), linoleic acid (10.9-23.5%), oleic acid (11.5-19.2%), palmitic acid (5.2-6.8%) and stearic acid (2.0-3.7%) and, total fatty acid compositions of species were analyzed and results were found as 36.2-49.8%, 17.1-25.8%, 15.4-25.8%, 6.4-7.8%, and 2.7-4.1%, respectively.

  2. Amino acid composition of Lagenaria siceraria seed flour and protein fractions.

    PubMed

    Ogunbusola, Moriyike Esther; Fagbemi, Tayo Nathaniel; Osundahunsi, Oluwatooyin Faramade

    2010-12-01

    Defatted seed flours of Lagenaria siceraria (calabash and bottle gourd) were fractionated into their major protein fractions. The amino acid composition of seed flours and their protein fractions were determined and the protein quality was evaluated. Glutamic acid (139-168 mg/g protein) was the most abundant amino acid followed by aspartic acid (89.0-116 mg/g protein) in both the seed flours and their protein fractions. The total essential amino acid ranged from 45.8 to 51.5%. The predicted protein efficiency ratio and the predicted biological value ranged from 2.4 to 2.9 and 8.7 to 44.0, respectively. Lysine and sulphur amino acids were mostly concentrated in the globulin fractions. The first and second limiting amino acids in seed flours and protein fractions were methionine and valine or threonine. The seed flours contained adequate essential amino acids required by growing school children and adults. The seed has potential as protein supplement in cereal based complementary diets or in the replacement of animal proteins in conventional foods.

  3. Effects of feeding camelina (seeds or meal) on milk fatty acid composition and butter spreadability.

    PubMed

    Hurtaud, C; Peyraud, J L

    2007-11-01

    The nutritional and rheological properties of butter depend on the fatty acid composition of milk. Therefore, feeding oilseeds rich in unsaturated fatty acids is likely to affect butter properties. The aim of this trial was to examine to what extent feeding the linolenic acid-rich cruciferous plant camelina can affect the fatty acid composition of dairy products and the properties of butter. A control diet composed of 60% corn silage-based ration and completed with high-energy and nitrogenous concentrates was compared with 2 experimental diets designed to provide the same amount of polyunsaturated fatty acids via either camelina seed (630 g/d, CS diet) or camelina meal (2 kg/d, CM diet). The diets were isoenergetic and isonitrogenous. The trial followed a double 3 x 3 Latin-square design with 4-wk periods on 6 Holstein dairy cows. The camelina diets tended to decrease dry matter intake but did not have a significant effect on milk production. They generated a slight decrease in milk protein and a strong decrease in milk fat yield and content. The CM diet led to a stronger decrease in fat content. Camelina generated a greater proportion of monounsaturated fatty acids, notably C18:1 trans isomers, including trans-10 and trans-11 C18:1, which increased by 11.0- and 2.6-fold, respectively, with the CM diet. Camelina also led to an increase in conjugated linoleic acids, particularly rumenic acid, cis-9, trans-11 C18:2. Camelina did not affect parameters of buttermaking except churning time with milk from CM fed cows, which was longer. The butters of camelina diets were softer at all temperatures tested, especially with the CM diet. In conclusion, feeding camelina can modify milk fatty acid profile and butter spreadability.

  4. Drought and heat stress effects on soybean fatty acid composition and oil stability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous studies have shown that oil concentration and fatty acid profile (composition) change with genotype, environment (mainly heat and drought), and geographical location. The changes in fatty acid composition under these conditions affect fatty acid stability, creating a challenge to oil proces...

  5. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E.P.; Alexandratos, S.D.; Gatrone, R.C.; Chiarizia, R.

    1995-09-12

    An ion exchange resin is described for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene. 10 figs.

  6. Phosphonic acid based exchange resins

    DOEpatents

    Horwitz, E. Philip; Alexandratos, Spiro D.; Gatrone, Ralph C.; Chiarizia, Ronato

    1995-01-01

    An ion exchange resin for extracting metal ions from a liquid waste stream. An ion exchange resin is prepared by copolymerizing a vinylidene diphosphonic acid with styrene, acrylonitrile and divinylbenzene.

  7. The Conjugate Acid-Base Chart.

    ERIC Educational Resources Information Center

    Treptow, Richard S.

    1986-01-01

    Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

  8. Students' Alternate Conceptions on Acids and Bases

    ERIC Educational Resources Information Center

    Pan, Hanqing; Henriques, Laura

    2015-01-01

    Knowing what students bring to the classroom can and should influence how we teach them. This study is a review of the literature associated with secondary and postsecondary students' ideas about acids and bases. It was found that there are six types of alternate ideas about acids and bases that students hold. These are: macroscopic properties of…

  9. The Kidney and Acid-Base Regulation

    ERIC Educational Resources Information Center

    Koeppen, Bruce M.

    2009-01-01

    Since the topic of the role of the kidneys in the regulation of acid base balance was last reviewed from a teaching perspective (Koeppen BM. Renal regulation of acid-base balance. Adv Physiol Educ 20: 132-141, 1998), our understanding of the specific membrane transporters involved in H+, HCO , and NH transport, and especially how these…

  10. Polyunsaturated fatty acids and conjugated linoleic acid isomers in breast milk are associated with plasma non-esterified and erythrocyte membrane fatty acid composition in lactating women.

    PubMed

    Torres, Alexandre G; Ney, Jacqueline G; Meneses, Flávia; Trugo, Nádia M F

    2006-03-01

    Maternal adipose tissue is a major contributor to breast milk long-chain fatty acids, probably through the pool of plasma NEFA. The fatty acid composition of the erythrocyte membrane (EM) is a biochemical index of the intake of fatty acids not synthesized endogenously and of PUFA and long-chain PUFA fatty acid status. The present study investigated the associations between breast milk fatty acid composition and the composition of plasma NEFA and of EM fatty acids with special reference to PUFA, long-chain PUFA and conjugated linoleic acid (CLA). The detailed fatty acid composition of mature breast milk was also reported. Thirty-three healthy, lactating Brazilian women donated milk samples; of these, twenty-four also donated blood samples in an observational cross-sectional study. Breast milk fatty acid composition presented several associations with NEFA and EM composition, which explained most (> or =50 %) of the variability of selected milk PUFA, long-chain PUFA and CLA. Milk CLA was associated with fatty acids that are markers of dairy fat intake in the diet, NEFA and EM. In general, breast milk n-3 fatty acids and CLA, but not n-6 fatty acids, were associated with EM composition, whereas both the n-6 and n-3 fatty acids and CLA in milk were associated with NEFA composition, possibly owing to its role as a direct source of fatty acids for breast milk. These findings emphasize the contribution of the NEFA pool derived from the adipose tissue to the long-chain fatty acid composition of breast milk.

  11. Dietary fatty acids influence the growth and fatty acid composition of the yellow mealworm Tenebrio molitor (Coleoptera: Tenebrionidae).

    PubMed

    Dreassi, Elena; Cito, Annarita; Zanfini, Assunta; Materozzi, Lara; Botta, Maurizio; Francardi, Valeria

    2017-03-01

    Fat is the second most abundant component of the nutrient composition of the mealworm Tenebrio molitor (Coleoptera: Tenebrionidae) that represents also an interesting source of PUFA, especially n-6 and n-3 fatty acids, involved in prevention of cardiovascular diseases. This study investigated the possibility of modifying the fat content and the FA composition of yellow mealworms through feeding and how this would be influenced by developmental stages, pupal sex, and generation with the future aim of applying this coleopteran as a diet supplement for human health. Growth rate and cumulative mortality percentage on the different feeding substrates were also evaluated to select the optimal conditions for a mass-raising of this insect species. Despite the different fat content in the six different breeding substrates used, T. molitor larvae and pupae contained a constant fat percentage (>34% in larvae and >30% in pupae). A similar total fat content was found comparing larvae and male and female pupae of the second generation to those of the first generation. On the contrary, FA composition differed both in larvae and pupae reared on the different feeding substrates. However, the exemplars reared on the diets based on 100% bread and 100% oat flour showed SFA, PUFA percentages, and an n-6/n-3 ratio more suitable for human consumption; the diet based on beer yeast, wheat flour, and oat flour resulted in a contemporary diet that most satisfied the balance between a fat composition of high quality and favorable growth conditions.

  12. Conjugated linoleic acid (CLA) and fatty acid composition of milk, curd and Grana Padano cheese in conventional and organic farming systems.

    PubMed

    Prandini, Aldo; Sigolo, Samantha; Piva, Gianfranco

    2009-08-01

    CLA levels and fatty acid composition were measured to compare the fat composition in organic bulk milk, destined to the production of Grana Padano cheese, with those produced by conventional system. The curds and Grana Padano cheeses were also analysed to evaluate the effects of the production technology on the CLA content. All analysed organic samples were characterized by higher annual means of CLA, vaccenic acid (TVA) and linolenic acid (LNA) in comparison with conventional samples (with P<0.05). Nevertheless, no particular effect of the production technology was seen on the CLA content. The animal diet appears to be the factor which has the highest effect on the CLA concentration in milk and milk products and an organic diet based on fresh or dried forage, that is rich in CLA precursory fatty acids, may improve the yield of fatty acids with beneficial effects on health.

  13. Composition and flux of particulate amino acids and chloropigments in equatorial Pacific seawater and sediments

    NASA Astrophysics Data System (ADS)

    Lee, Cindy; Wakeham, Stuart G.; Hedges, John I.

    2000-08-01

    Compositions and fluxes of amino acids and major chloropigments were measured in the central equatorial Pacific Ocean as part of the US JGOFS EqPac program. Fluxes decreased by several orders of magnitude, from 400 to 0.03 mg amino acid m -2 d -1 and from 9 mg to 0.0004 μg chloropigment m -2 d -1, between production in the surface waters and accumulation at the sea floor. Most rapid losses were in surface waters and at the sediment interface. Losses from the mid-water column were as great as those in surface waters or at the sediment interface, but occurred over a much greater depth range. Export flux estimates based on floating sediment traps were higher near the equator and decreased poleward, similar to primary production. Little meridional difference was apparent in composition of either amino acids or pigments in exported material over the 24° of latitude sampled in spite of the large (factor of 5-6) difference in fluxes. However, pigment composition changed dramatically with depth in the water column, and considerable diagenesis occurred before particles reached the sediment. Pigment compositions suggest that suspended particles were more degraded in the northern than in the southern hemisphere, possibly due to differences in food chain structure. Compositional changes in amino acids occurred in the water column, but were most noticeable at the sediment-seawater interface. Increases in the relative proportions of aspartic acid and glycine with depth were more consistent with preferential preservation within the particulate matrix than with any inherent stability of these compounds to heterotrophic consumption. The contribution of amino acids and pigments to total organic carbon clearly shows that selective degradation of organic matter occurs with depth; this is not evident from total organic carbon data alone. Amino acids contributed about a quarter of the total organic carbon (OC) in surface waters and 16% of the OC in sediment; pigments decreased from 1

  14. Protein packing: dependence on protein size, secondary structure and amino acid composition.

    PubMed

    Fleming, P J; Richards, F M

    2000-06-02

    We have used the occluded surface algorithm to estimate the packing of both buried and exposed amino acid residues in protein structures. This method works equally well for buried residues and solvent-exposed residues in contrast to the commonly used Voronoi method that works directly only on buried residues. The atomic packing of individual globular proteins may vary significantly from the average packing of a large data set of globular proteins. Here, we demonstrate that these variations in protein packing are due to a complex combination of protein size, secondary structure composition and amino acid composition. Differences in protein packing are conserved in protein families of similar structure despite significant sequence differences. This conclusion indicates that quality assessments of packing in protein structures should include a consideration of various parameters including the packing of known homologous proteins. Also, modeling of protein structures based on homologous templates should take into account the packing of the template protein structure.

  15. Predicting lipase types by improved Chou's pseudo-amino acid composition.

    PubMed

    Zhang, Guang-Ya; Li, Hong-Chun; Gao, Jia-Qiang; Fang, Bai-Shan

    2008-01-01

    By proposing a improved Chou's pseudo amino acid composition approach to extract the features of the sequences, a powerful predictor based on k-nearest neighbor was introduced to identify the types of lipases according to their sequences. To avoid redundancy and bias, demonstrations were performed on a dataset where none of the proteins has > or =25% sequence identity to any other. The overall success rate thus obtained by the 10-fold cross-validation test was over 90%, indicating that the improved Chou's pseudo amino acid composition might be a useful tool for extracting the features of protein sequences, or at lease can play a complementary role to many of the other existing approaches.

  16. Enhanced proton conductivity of Nafion composite membrane by incorporating phosphoric acid-loaded covalent organic framework

    NASA Astrophysics Data System (ADS)

    Yin, Yongheng; Li, Zhen; Yang, Xin; Cao, Li; Wang, Chongbin; Zhang, Bei; Wu, Hong; Jiang, Zhongyi

    2016-11-01

    Design and fabrication of efficient proton transport channels within solid electrolytes is crucial and challenging to new energy-relevant devices such as proton exchange membrane fuel cells (PEMFCs). In this study, the phosphoric acid (H3PO4) molecules are impregnated into SNW-1-type covalent organic frameworks (COFs) via vacuum assisted method. High loading of H3PO4 in SNW-1 and low guest leaching rate are achieved due to the similar diameter between H3PO4 and micropores in SNW-1. Then the COF-based composite membranes are fabricated for the first time with impregnated COFs (H3PO4@SNW-1) and Nafion matrix. For the composite membranes, the acid-base pairs formed between H3PO4@SNW-1 networks and Nafion optimize the interfacial interactions and hydrophilic domains. The acidic -PO3H2 groups in pores of H3PO4@SNW-1 provide abundant proton transfer sites. As a result, the continuous proton transfer channels with low energy barrier are created. At the filler content of 15 wt%, the composite membrane exhibits a superior proton conductivity of 0.0604 S cm-1 at 51% relative humidity and 80 °C. At the same time, the maximum power density of single fuel cell is 60.3% higher than that of the recast Nafion membrane.

  17. Metal salts of alkyl catechol dithiophosphoric acids and oil compositions containing the salts

    SciTech Connect

    Yamaguchi, E.S.; Liston, T.V.

    1988-03-08

    Metal salts of alkyl catechol esters of dithiophosphoric acid suitable as additives in oil compositions are disclosed in this patent. Oil compositions containing the salts of such esters show improved extreme pressure/anti-wear and anit-oxidant properties.

  18. Hydroxyapatite nanorod-reinforced biodegradable poly(L-lactic acid) composites for bone plate applications.

    PubMed

    Aydin, Erkin; Planell, Josep A; Hasirci, Vasif

    2011-11-01

    Novel PLLA composite fibers containing hydroxyapatite (HAp) nanorods with or without surface lactic acid grafting were produced by extrusion for use as reinforcements in PLLA-based bone plates. Fibers containing 0-50% (w/w) HAp nanorods, aligned parallel to fiber axis, were extruded. Lactic acid surface grafting of HAp nanorods (lacHAp) improved the tensile properties of composites fibers better than the non-grafted ones (nHAp). Best tensile modulus values of 2.59, 2.49, and 4.12 GPa were obtained for loadings (w/w) with 30% lacHAp, 10% nHAp, and 50% amorphous HAp nanoparticles, respectively. Bone plates reinforced with parallel rows of these composite fibers were molded by melt pressing. The best compressive properties for plates were obtained with nHAp reinforcement (1.31 GPa Young's Modulus, 110.3 MPa compressive strength). In vitro testing with osteoblasts showed good cellular attachment and spreading on composite fibers. In situ degradation tests revealed faster degradation rates with increasing HAp content. To our knowledge, this is the first study containing calcium phosphate-polymer nanocomposite fibers for reinforcement of a biodegradable bone plate or other such implants and this biomimetic design was concluded to have potential for production of polymer-based biodegradable bone plates even for load bearing applications.

  19. Chemical characteristics, fatty acid composition and conjugated linoleic acid (CLA) content of traditional Greek yogurts.

    PubMed

    Serafeimidou, Amalia; Zlatanos, Spiros; Laskaridis, Kostas; Sagredos, Angelos

    2012-10-15

    Many studies with conjugated linoleic acid (CLA) indicate that it has a protective effect against mammary cancer. Because dairy products are the most important dietary sources of CLA, we have investigated the CLA concentrations and additionally the fatty acid profiles and chemical composition of several commercial, traditional, Greek yogurts from different geographical origin. The fat content of yogurts was in the order of goatacids (SFA) were found in low-fat yogurts, of monounsaturated fatty acids (MUFA) in sheep milk yogurts and of polyunsaturated fatty acid (PUFA) in low-fat cow milk yogurts.

  20. Sequential injection redox or acid-base titration for determination of ascorbic acid or acetic acid.

    PubMed

    Lenghor, Narong; Jakmunee, Jaroon; Vilen, Michael; Sara, Rolf; Christian, Gary D; Grudpan, Kate

    2002-12-06

    Two sequential injection titration systems with spectrophotometric detection have been developed. The first system for determination of ascorbic acid was based on redox reaction between ascorbic acid and permanganate in an acidic medium and lead to a decrease in color intensity of permanganate, monitored at 525 nm. A linear dependence of peak area obtained with ascorbic acid concentration up to 1200 mg l(-1) was achieved. The relative standard deviation for 11 replicate determinations of 400 mg l(-1) ascorbic acid was 2.9%. The second system, for acetic acid determination, was based on acid-base titration of acetic acid with sodium hydroxide using phenolphthalein as an indicator. The decrease in color intensity of the indicator was proportional to the acid content. A linear calibration graph in the range of 2-8% w v(-1) of acetic acid with a relative standard deviation of 4.8% (5.0% w v(-1) acetic acid, n=11) was obtained. Sample throughputs of 60 h(-1) were achieved for both systems. The systems were successfully applied for the assays of ascorbic acid in vitamin C tablets and acetic acid content in vinegars, respectively.

  1. Fatty acid concentration, proximate composition, and mineral composition in fishbone flour of Nile Tilapia.

    PubMed

    Petenuci, Maria Eugênia; Stevanato, Flávia Braidoti; Visentainer, Jeane Eliete Laguila; Matsushita, Makoto; Garcia, Edivaldo Egea; de Souza, Nilson Evelázio; Visentainer, Jesui Vergilio

    2008-03-01

    Nile tilapia (Oreochormis niloticus) fishbone is a fish part with unknown composition. After elaboration of flour fishbone of tilapia it was analysede. The results in 100 g of flour were: moisture (14.2%), protein (40.8%), total lipids (25.3%), and ash (18.3%), and mineral (in 100 g) was 2715.9 mg (calcium), 1.3 mg (iron), and 1132.7 mg (phosphorus). A total of 22 fatty acids were detected in fishbone flour total lipids (TL), being the major ones in (g) of total lipids: 16:0 (208.5 mg); 18:1n-9 (344.3 mg); and 18:2n-6 (109.6 mg). The concentration of linolenic acid--LNA (18:3n-3); eicopentaenoic acid--EPA (20:5n-3), and docosahexaenoic acid--DHA (22:6n-3) were (29.9 mg), (3.3 mg), and (12.9 mg), respectively. The content to saturated (SFA) were (296.2 mg), monounsaturated (MUFA) 415.0 mg, and polyunsaturated (PUFA) 175.6 mg. The ratio PUFA:MUFA:SFA was 1:2.4:1.7, and the ratio omega-6/omega-3 fatty acids were 2.8. The last is within the recommended values. The results show low concentrations of omega-3 fatty acids in flour. The value caloric and calcium, iron, phosphorus, and protein content the fishbone flour of tilapia may results a valuable alternative food in the human diet.

  2. Effect of Gallic acid on mechanical and water barrier properties of zein-oleic acid composite films.

    PubMed

    Masamba, Kingsley; Li, Yue; Hategekimana, Joseph; Liu, Fei; Ma, Jianguo; Zhong, Fang

    2016-05-01

    In this study, the effect of gallic acid on mechanical and water barrier properties of zein-oleic acid 0-4 % composite films was investigated. Molecular weight distribution analysis was carried out to confirm gallic acid induced cross linking through change in molecular weight in fraction containing zein proteins. Results revealed that gallic acid treatment increased tensile strength from 17.9 MPa to 26.0 MPa, decreased water vapour permeability from 0.60 (g mm m(-2) h(-1) kPa(-1)) to 0.41 (g mm m(-2) h(-1) kPa(-1)), increased solubility from 6.3 % to 10.2 % and marginally increased elongation at break from 3.7 % to 4.2 % in zein films only. However, gallic acid treatment in zein-oleic composite films did not significantly influence mechanical and water barrier properties and in most instances irrespective of oleic acid concentration, the properties were negatively affected. Results from scanning electron microscopy showed that both gallic acid treated and untreated zein films and composite films containing 3 % oleic acid had a compact and homogeneous structure while those containing 4 % oleic acid had inhomogeneous structure. The findings have demonstrated that gallic acid treatment can significantly improve mechanical and water barrier properties especially in zein films only as opposed to when used in composite films using zein and oleic acid.

  3. Fatty acid composition of goat diets vs intramuscular fat.

    PubMed

    Rhee, K S; Waldron, D F; Ziprin, Y A; Rhee, K C

    2000-04-01

    Twenty Boer x Spanish goats, at the age range of 90-118 days, were assigned to two dietary treatments, with 10 animals fed a grain ration (G) and the other 10 grazed in rangeland. The grain ration contained sorghum grain (67.5%), cottonseed hulls, dehydrated alfalfa meal, cottonseed meal, soybean meal, molasses, and mineral and vitamin supplements. Animals were slaughtered at the age range of 206-234 days. Intramuscular fat (IF) and the diet specimens - representative samples of G and the parts of range plants (RPs) that goats were expected to have consumed - were analyzed for fatty acid composition. The percentage of 16:0 was higher in RPs than in G, but not different between IF from range goats and that from grain-fed goats. Total unsaturated fatty acid (UFA) percentage was higher in G than in RPs. The major UFAs were 18:2 and 18:3 in RPs, and 18:1 and 18:2 in G. In IF, 18:1 constituted more than two-thirds of UFAs, regardless of diet type.

  4. Fatty Acid and Proximate Composition of Bee Bread

    PubMed Central

    Kaplan, Muammer; Karaoglu, Öznur; Eroglu, Nazife

    2016-01-01

    Summary Palynological spectrum, proximate and fatty acid (FA) composition of eight bee bread samples of different botanical origins were examined and significant variations were observed. The samples were all identified as monofloral, namely Castanea sativa (94.4%), Trifolium spp. (85.6%), Gossypium hirsutum (66.2%), Citrus spp. (61.4%) and Helianthus annuus (45.4%). Each had moisture content between 11.4 and 15.9%, ash between 1.9 and 2.54%, fat between 5.9 and 11.5%, and protein between 14.8 and 24.3%. A total of 37 FAs were determined with most abundant being (9Z,12Z,15Z)-octadeca-9,12,15-trienoic, (9Z,12Z)- -octadeca-9,12-dienoic, hexadecanoic, (Z)-octadec-9-enoic, (Z)-icos-11-enoic and octadecanoic acids. Among all, cotton bee bread contained the highest level of ω-3 FAs, i.e. 41.3%. Unsaturated to saturated FA ratio ranged between 1.38 and 2.39, indicating that the bee bread can be a good source of unsaturated FAs. PMID:28115909

  5. Unusual fatty acid compositions of the hyperthermophilic archaeon Pyrococcus furiosus and the bacterium Thermotoga maritima.

    PubMed Central

    Carballeira, N M; Reyes, M; Sostre, A; Huang, H; Verhagen, M F; Adams, M W

    1997-01-01

    The fatty acid compositions of the hyperthermophilic microorganisms Thermotoga maritima and Pyrococcus furiosus were studied and compared. A total of 37 different fatty acids were identified in T. maritima, including the novel 13,14-dimethyloctacosanedioic acid. In contrast, a total of 18 different fatty acids were characterized, as minor components, in P. furiosus, and these included saturated, monounsaturated, and dicarboxylic acids. This is the first report of fatty acids from an archaeon. PMID:9098079

  6. Improving fatty acid composition in peanuts (Arachis hypogaea) by SNP genotyping and traditional breeding.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid composition is an important seed quality trait in cultivated peanuts (Arachis hypogaea L.). Monounsaturated fats, such as oleic acid (C18:1), an omega-9 fatty acid, has been shown to have beneficial effects on human health. In addition, peanuts bred to produce high levels of oleic acid ...

  7. Acid and base degraded products of ketorolac.

    PubMed

    Salaris, Margherita; Nieddu, Maria; Rubattu, Nicola; Testa, Cecilia; Luongo, Elvira; Rimoli, Maria Grazia; Boatto, Gianpiero

    2010-06-05

    The stability of ketorolac tromethamine was investigated in acid (0.5M HCl) and alkaline conditions (0.5M NaOH), using the same procedure reported by Devarajan et al. [2]. The acid and base degradation products were identified by liquid chromatography-mass spectrometry (LC-MS).

  8. Rheological, microstructural, and in vitro characterization of hybrid chitosan-polylactic acid/hydroxyapatite composites.

    PubMed

    Araújo, A B A; Lemos, A F; Ferreira, J M F

    2009-03-15

    In this work, hybrid chitosan/hydroxyapatite composites material were developed and characterized. The polymer matrix was first dissolved in polylactic acid, and then hydroxyapatite (HA) was added as filler material. The effects of the added amounts of a crosslinking agent (genipin) and of the concentrations of lactic acid, and of the presence of HA powder on the evolution of rheological properties were evaluated. A significant decrease of gelation time with increasing amounts of crosslinking agent was observed, the effect being even more pronounced in the presence of HA. The chitosan matrix and the composites with a chitosan/HA weight ratio of 2/5 were characterized using microstructural analysis and in vitro tests. The formation of large pore sizes in the chitosan-based scaffolds was favored by low concentrations of lactic acid and genipin. The in vitro tests in synthetic body fluid revealed an extensive formation of an apatitic layer onto the surface of the chitosan/HA composite scaffolds crosslinked with genipin.

  9. Automatic 1H-NMR Screening of Fatty Acid Composition in Edible Oils

    PubMed Central

    Castejón, David; Fricke, Pascal; Cambero, María Isabel; Herrera, Antonio

    2016-01-01

    In this work, we introduce an NMR-based screening method for the fatty acid composition analysis of edible oils. We describe the evaluation and optimization needed for the automated analysis of vegetable oils by low-field NMR to obtain the fatty acid composition (FAC). To achieve this, two scripts, which automatically analyze and interpret the spectral data, were developed. The objective of this work was to drive forward the automated analysis of the FAC by NMR. Due to the fact that this protocol can be carried out at low field and that the complete process from sample preparation to printing the report only takes about 3 min, this approach is promising to become a fundamental technique for high-throughput screening. To demonstrate the applicability of this method, the fatty acid composition of extra virgin olive oils from various Spanish olive varieties (arbequina, cornicabra, hojiblanca, manzanilla, and picual) was determined by 1H-NMR spectroscopy according to this protocol. PMID:26891323

  10. Carbohydrate, Organic Acid, and Amino Acid Composition of Bacteroids and Cytosol from Soybean Nodules 1

    PubMed Central

    Streeter, John G.

    1987-01-01

    Metabolites in Bradyrhizobium japonicum bacteroids and in Glycine max (L.) Merr. cytosol from root nodules were analyzed using an isolation technique which makes it possible to estimate and correct for changes in concentration which may occur during bacteroid isolation. Bacteroid and cytosol extracts were fractionated on ion-exchange columns and were analyzed for carbohydrate composition using gas-liquid chromatography and for organic acid and amino acid composition using high performance liquid chromatography. Analysis of organic acids in plant tissues as the phenacyl derivatives is reported for the first time and this approach revealed the presence of several unknown organic acids in nodules. The time required for separation of bacteroids and cytosol was varied, and significant change in concentration of individual compounds during the separation of the two fractions was estimated by calculating the regression of concentration on time. When a statistically significant slope was found, the true concentration was estimated by extrapolating the regression line to time zero. Of 78 concentration estimates made, there was a statistically significant (5% level) change in concentration during sample preparation for only five metabolites: glucose, sucrose, and succinate in the cytosol and d-pinitol and serine in bacteroids. On a mass basis, the major compounds in bacteroids were (descending order of concentration): myo-inositol, d-chiro-inositol, α,α-trehalose, sucrose, aspartate, glutamate, d-pinitol, arginine, malonate, and glucose. On a proportional basis (concentration in bacteroid as percent of concentration in bacteroid + cytosol fractions), the major compounds were: α-aminoadipate (94), trehalose (66), lysine (58), and arginine (46). The results indicate that metabolite concentrations in bacteroids can be reliably determined. PMID:16665774

  11. Essential fatty acid intake and serum fatty acid composition among adolescent girls in central Mozambique.

    PubMed

    Freese, Riitta; Korkalo, Liisa; Vessby, Bengt; Tengblad, Siv; Vaara, Elina M; Hauta-alus, Helena; Selvester, Kerry; Mutanen, Marja

    2015-04-14

    Many African diets are low in fat but are currently changing because of nutrition transition. We studied fat and fatty acid (FA) intake and the essential fatty acid (EFA) status of adolescent girls (aged 14-19 years, n 262) in Zambezia Province, central Mozambique. A cross-sectional study was carried out in a city as well as in the towns and rural villages of a coastal and an inland district. Dietary intake and FA sources were studied in a 24 h dietary recall. FA compositions of cholesteryl esters and phospholipids of non-fasting serum samples were analysed by GLC. Fat intake was low (13-18 % of energy) in all areas. Coconut and palm oil were the main sources of fat, and soyabean oil and maize were the main sources of PUFA. Compared to Food and Agriculture Organization/WHO 2010 recommendations, intake of linoleic acid (LA, 18 : 2n-6) was inadequate in the coastal district, and intakes of n-3 PUFA were inadequate in all areas. FA compositions of serum lipids differed between areas. The proportions of LA tended to be highest in the city and lowest in the rural areas. The phospholipid mead (20 : 3n-9):arachidonic acid (20 : 4n-6) ratio did not indicate EFA insufficiency. LA proportions in phospholipids were low, but those of long-chain n-6 and n-3 PUFA were high in comparison with Western adolescents. To conclude, fat sources, FA intake and EFA status differed between adolescent girls living in different types of communities. Fat intake was low, but EFA insufficiency was not indicated.

  12. MoSi2-Base Composites

    NASA Technical Reports Server (NTRS)

    Hebsur, Mohan G.

    2003-01-01

    Addition of 30 to 50 vol% of Si3N4 particulate to MoSi2 eliminated its low temperature catastrophic failure, improved room temperature fracture toughness and the creep resistance. The hybrid composite SCS-6/MoSi2-Si3N4 did not show any matrix cracking and exhibited excellent mechanical and environmental properties. Hi-Nicalon continuous fiber reinforced MoSi2-Si3N4 also showed good strength and toughness. A new MoSi2-base composite containing in-situ whisker-type (Beta)Si3N4 grains in a MoSi2 matrix is also described.

  13. Ammonia gas sensing behavior of tanninsulfonic acid doped polyaniline-TiO₂ composite.

    PubMed

    Bairi, Venu Gopal; Bourdo, Shawn E; Sacre, Nicolas; Nair, Dev; Berry, Brian C; Biris, Alexandru S; Viswanathan, Tito

    2015-10-16

    A highly active tannin doped polyaniline-TiO₂ composite ammonia gas sensor was developed and the mechanism behind the gas sensing activity was reported for the first time. A tanninsulfonic acid doped polyaniline (TANIPANI)-titanium dioxide nanocomposite was synthesized by an in situ polymerization of aniline in the presence of tanninsulfonic acid and titanium dioxide nanoparticles. X-ray diffraction and thermogravimetric analysis were utilized to determine the incorporation of TiO₂ in TANIPANI matrix. UV-Visible and infrared spectroscopy studies provided information about the electronic interactions among tannin, polyaniline, and TiO₂. Scanning electron microscopy (SEM) along with energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM) surface analysis techniques were used to investigate the metal oxide dispersions inside polyaniline matrix. Gas sensors were prepared by spin coating solutions of TANIPANI-TiO₂ and TANIPANI composites onto glass slides. Sensors were tested at three different concentrations (20 ppm, 40 ppm, and 60 ppm) of ammonia gas at ambient temperature conditions by measuring the changes in surface resistivity of the films with respect to time. Ammonia gas sensing plots are presented showing the response values, response times and recovery times. The TANIPANI-TiO₂ composite exhibited better response and shorter recovery times when compared to TANIPANI control and other polyaniline composites that have been reported in the literature. For the first time a proposed mechanism of gas sensing basing on the polaron band localization and its effects on the gas sensing behavior of polyaniline are reported.

  14. Trans fatty acids and fatty acid composition of mature breast milk in turkish women and their association with maternal diet's.

    PubMed

    Samur, Gülhan; Topcu, Ali; Turan, Semra

    2009-05-01

    The aim of this study was to determine the fatty acid composition and trans fatty acid and fatty acid contents of breast milk in Turkish women and to find the effect of breastfeeding mothers' diet on trans fatty acid and fatty acid composition. Mature milk samples obtained from 50 Turkish nursing women were analyzed. Total milk lipids extracts were transmethylated and analyzed by using gas liquid chromatography to determine fatty acids contents. A questionnaire was applied to observe eating habits and 3 days dietary records from mothers were obtained. Daily dietary intake of total energy and nutrients were estimated by using nutrient database. The mean total trans fatty acids contents was 2.13 +/- 1.03%. The major sources of trans fatty acids in mothers' diets were margarines-butter (37.0%), bakery products and confectionery (29.6%). Mothers who had high level of trans isomers in their milk consumed significantly higher amounts of these products. Saturated fatty acids, polyunsaturated fatty acids and monounsaturated fatty acids of human milk constituted 40.7 +/- 4.7%, 26.9 +/- 4.2% and 30.8 +/- 0.6% of the total fatty acids, respectively. The levels of fatty acids in human milk may reflect the current diet of the mother as well as the diet consumed early in pregnancy. Margarines, bakery products and confectionery are a major source of trans fatty acids in maternal diet in Turkey.

  15. Poly(L-lactic acid)/hydroxyapatite/collagen composite coatings on AZ31 magnesium alloy for biomedical application.

    PubMed

    Wang, Zhen-Lin; Yan, Yu-Hua; Wan, Tao; Yang, Hui

    2013-10-01

    Surface modification of biomedical magnesium alloy using composite coating shows an attemptable approach for the development of Mg-based biomaterials with excellent cytocompatibility. Hydroxyapatite/collagen composite was preliminarily fabricated by biomineralization, the bioactive poly(l-lactic acid)/hydroxyapatite/collagen composite coatings were spin coated on AZ31 magnesium alloy using poly(l-lactic acid) solution mixed with hydroxyapatite/collagen particles, and the resultant materials and coatings were characterized in structure and related properties; furthermore, the in vitro degradation behavior of modified magnesium alloy in 1.5-fold Hank's solution was investigated. The results show that hydroxyapatite/collagen composite achieved chemical bonding between hydroxyapatite and collagen similar to natural bone; composite coatings on AZ31 magnesium alloy retained the bioactive functional groups of the componential materials and improved the corrosion resistance of Mg alloy; the mass fraction of hydroxyapatite/collagen particles incorporated into the composite affected the porous structure, interfacial adhesion and thus the corrosion resistance of the composite coating due to phase separation as well as volume concentration effects of polymer solution. Composite coatings suppressed the sharp rising of pH value and the released Mg(2+) from substrate to extensive degree, and the degradation behavior of the modified magnesium alloy was supposed to be correlated to microstructure of the coating as well as the synergistic reactions among alkaline- and acidic-degraded products.

  16. Crack Formation in Cement-Based Composites

    NASA Astrophysics Data System (ADS)

    Sprince, A.; Pakrastinsh, L.; Vatin, N.

    2016-04-01

    The cracking properties in cement-based composites widely influences mechanical behavior of construction structures. The challenge of present investigation is to evaluate the crack propagation near the crack tip. During experiments the tension strength and crack mouth opening displacement of several types of concrete compositions was determined. For each composition the Compact Tension (CT) specimens were prepared with dimensions 150×150×12 mm. Specimens were subjected to a tensile load. Deformations and crack mouth opening displacement were measured with extensometers. Cracks initiation and propagation were analyzed using a digital image analysis technique. The formation and propagation of the tensile cracks was traced on the surface of the specimens using a high resolution digital camera with 60 mm focal length. Images were captured during testing with a time interval of one second. The obtained experimental curve shows the stages of crack development.

  17. Whole body acid-base modeling revisited.

    PubMed

    Ring, Troels; Nielsen, Søren

    2017-04-01

    The textbook account of whole body acid-base balance in terms of endogenous acid production, renal net acid excretion, and gastrointestinal alkali absorption, which is the only comprehensive model around, has never been applied in clinical practice or been formally validated. To improve understanding of acid-base modeling, we managed to write up this conventional model as an expression solely on urine chemistry. Renal net acid excretion and endogenous acid production were already formulated in terms of urine chemistry, and we could from the literature also see gastrointestinal alkali absorption in terms of urine excretions. With a few assumptions it was possible to see that this expression of net acid balance was arithmetically identical to minus urine charge, whereby under the development of acidosis, urine was predicted to acquire a net negative charge. The literature already mentions unexplained negative urine charges so we scrutinized a series of seminal papers and confirmed empirically the theoretical prediction that observed urine charge did acquire negative charge as acidosis developed. Hence, we can conclude that the conventional model is problematic since it predicts what is physiologically impossible. Therefore, we need a new model for whole body acid-base balance, which does not have impossible implications. Furthermore, new experimental studies are needed to account for charge imbalance in urine under development of acidosis.

  18. Synthesis of new kojic acid based unnatural α-amino acid derivatives.

    PubMed

    Balakrishna, C; Payili, Nagaraju; Yennam, Satyanarayana; Devi, P Uma; Behera, Manoranjan

    2015-11-01

    An efficient method for the preparation of kojic acid based α-amino acid derivatives by alkylation of glycinate schiff base with bromokojic acids have been described. Using this method, mono as well as di alkylated kojic acid-amino acid conjugates have been prepared. This is the first synthesis of C-linked kojic acid-amino acid conjugate where kojic acid is directly linked to amino acid through a C-C bond.

  19. Mito-GSAAC: mitochondria prediction using genetic ensemble classifier and split amino acid composition.

    PubMed

    Afridi, Tariq Habib; Khan, Asifullah; Lee, Yeon Soo

    2012-04-01

    Mitochondria are all-important organelles of eukaryotic cells since they are involved in processes associated with cellular mortality and human diseases. Therefore, trustworthy techniques are highly required for the identification of new mitochondrial proteins. We propose Mito-GSAAC system for prediction of mitochondrial proteins. The aim of this work is to investigate an effective feature extraction strategy and to develop an ensemble approach that can better exploit the advantages of this feature extraction strategy for mitochondria classification. We investigate four kinds of protein representations for prediction of mitochondrial proteins: amino acid composition, dipeptide composition, pseudo amino acid composition, and split amino acid composition (SAAC). Individual classifiers such as support vector machine (SVM), k-nearest neighbor, multilayer perceptron, random forest, AdaBoost, and bagging are first trained. An ensemble classifier is then built using genetic programming (GP) for evolving a complex but effective decision space from the individual decision spaces of the trained classifiers. The highest prediction performance for Jackknife test is 92.62% using GP-based ensemble classifier on SAAC features, which is the highest accuracy, reported so far on the Mitochondria dataset being used. While on the Malaria Parasite Mitochondria dataset, the highest accuracy is obtained by SVM using SAAC and it is further enhanced to 93.21% using GP-based ensemble. It is observed that SAAC has better discrimination power for mitochondria prediction over the rest of the feature extraction strategies. Thus, the improved prediction performance is largely due to the better capability of SAAC for discriminating between mitochondria and non-mitochondria proteins at the N and C terminus and the effective combination capability of GP. Mito-GSAAC can be accessed at http://111.68.99.218/Mito-GSAAC . It is expected that the novel approach and the accompanied predictor will have a

  20. All Biomass and UV Protective Composite Composed of Compatibilized Lignin and Poly (Lactic-acid)

    PubMed Central

    Kim, Youngjun; Suhr, Jonghwan; Seo, Hee-Won; Sun, Hanna; Kim, Sanghoon; Park, In-Kyung; Kim, Soo-Hyun; Lee, Youngkwan; Kim, Kwang-Jin; Nam, Jae-Do

    2017-01-01

    Utilization of carbon-neutral biomass became increasingly important due to a desperate need for carbon reduction in the issue of global warming in light of replacing petroleum-based materials. We used lignin, which was an abundant, low cost, and non-food based biomass, for the development of all biomass-based films and composites through reactive compatibilization with poly (lactic-acid) (PLA). Using a facile and practical route, the hydrophilic hydroxyl groups of lignin were acetylated to impose the compatibility with PLA. The solubility parameter of the pristine lignin at 26.3 (J/cm3)0.5 was altered to 20.9 (J/cm3)0.5 by acetylation allowing the good compatibility with PLA at 20.2 (J/cm3)0.5. The improved compatibility of lignin and PLA provided substantially decreased lignin domain size in composites (12.7 μm), which subsequently gave transparent and UV-protection films (visual transmittance at 76% and UV protection factor over 40). The tensile strength and elongation of the developed composite films were increased by 22% and 76%, respectively, and the biobased carbon content was confirmed as 96 ± 3%. The developed PLA/lignin composites provided 100% all-biomass contents and balanced optical and mechanical properties that could broaden its eco-friendly applications in various industries.

  1. All Biomass and UV Protective Composite Composed of Compatibilized Lignin and Poly (Lactic-acid)

    NASA Astrophysics Data System (ADS)

    Kim, Youngjun; Suhr, Jonghwan; Seo, Hee-Won; Sun, Hanna; Kim, Sanghoon; Park, In-Kyung; Kim, Soo-Hyun; Lee, Youngkwan; Kim, Kwang-Jin; Nam, Jae-Do

    2017-03-01

    Utilization of carbon-neutral biomass became increasingly important due to a desperate need for carbon reduction in the issue of global warming in light of replacing petroleum-based materials. We used lignin, which was an abundant, low cost, and non-food based biomass, for the development of all biomass-based films and composites through reactive compatibilization with poly (lactic-acid) (PLA). Using a facile and practical route, the hydrophilic hydroxyl groups of lignin were acetylated to impose the compatibility with PLA. The solubility parameter of the pristine lignin at 26.3 (J/cm3)0.5 was altered to 20.9 (J/cm3)0.5 by acetylation allowing the good compatibility with PLA at 20.2 (J/cm3)0.5. The improved compatibility of lignin and PLA provided substantially decreased lignin domain size in composites (12.7 μm), which subsequently gave transparent and UV-protection films (visual transmittance at 76% and UV protection factor over 40). The tensile strength and elongation of the developed composite films were increased by 22% and 76%, respectively, and the biobased carbon content was confirmed as 96 ± 3%. The developed PLA/lignin composites provided 100% all-biomass contents and balanced optical and mechanical properties that could broaden its eco-friendly applications in various industries.

  2. Distribution and enantiomeric composition of amino acids in the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Engel, M. H.; Nagy, B.

    1982-01-01

    Studies of the amino acid contents and enantiomeric compositions of a single stone from the Murchison meteorite are reported. Water-extracted and 6M HCl-extracted samples from the meteorite interior of meteorite fragments were analyzed by gas chromatography and combined gas chromatography-chemical ionization mass spectrometry. Examination of the D/L ratios of glutamic acid, aspartic acid, proline, leucine and alanine reveals those amino acids extractable by water to be partially racemized, whereas the acid-extracted amino acids were less racemized. The amino acid composition of the stone is similar to those previously reported, including the absence of serine, threonine, tyrosine phenylalanine and methionine and the presence of unusual amino acids including such as isovaline, alpha-aminoisobutyric acid and pseudoleucine. It is concluded that the most likely mechanism accounting for the occurrence of nonracemic amino acid mixtures in the Murchison meteorite is by extraterrestrial stereoselective synthesis or decomposition reactions.

  3. Obesogenic diets enriched in oleic acid vs saturated fatty acids differentially modify polyunsaturated fatty acid composition in liver and visceral adipose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emerging evidence indicates that the fatty acid composition of obesogenic diets impacts physiologic outcomes. Much attention is focused on the biologic effects of consuming monounsaturated fatty acids (MUFA) vs saturated fatty acids (SFA). We investigated the extent to which an obesogenic diet high ...

  4. A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid

    SciTech Connect

    Arceo, Elena; Ellman, Jonathan; Bergman, Robert

    2010-05-03

    An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.

  5. Enhanced Osteoblast Functions on Nanophase Titania in Poly-lactic-co-glycolic Acid (PLGA) Composites

    DTIC Science & Technology

    2005-01-01

    Poly - lactic -co-glycolic Acid (PLGA) Composites Huinan Liu’, Elliott B. Slamovich’ and Thomas J. Webster’ 2 1School of Materials Engineering, 501...collagen matrix. For this purpose, poly - lactic -co- glycolic acid (PLGA) was dissolved in chloroform and nanometer grain size titania was dispersed by...gelatin, fibrin or collagen [4-6]), synthetic bioresorbable polymers (e.g., polylactic acid , polyglycolic acid and poly - lactic -co-glycolic acid [7-9

  6. Ontogenetic trends in aspartic acid racemization and amino acid composition within modern and fossil shells of the bivalve Arctica

    NASA Astrophysics Data System (ADS)

    Goodfriend, Glenn A.; Weidman, Christopher R.

    2001-06-01

    Ontogenetic trends (umbo to growth edge of shell) in aspartic acid (Asp) racemization and amino acid composition and their evolution over time are examined in serial samples of annual growth bands from a time-series of three live-collected and two fossil (ca. 500 and 1000 y BP) shells of the long-lived bivalve Arctica islandica. The rate of Asp racemization is shown to be higher in the umbonal portion of the shells (laid down when the clams are young) but constant from a biological age of 10 to 20 y to more than 100 y. Corresponding changes are also seen in amino acid composition and concentration: with increasing biological age of the clam: total amino acid concentration increases substantially, the acidic amino acids Asp, glutamic acid, and alanine decrease in relative concentration (mole-percent) and more basic amino acids including tyrosine, phenylalanine, and lysine increase in relative concentration. These ontogenetic trends are generally retained in the fossil shells. These trends may reflect changing protein composition related to changes in growth rate. Clams grow considerably faster in their youth than when they are older, as indicated by changes in the annual growth increments. Production of more acidic proteins, which play a role in crystal growth, may be favored during the phase of faster growth, whereas more structural proteins, perhaps enhancing structural strength of the shell, may be favored during later growth. These ontogenetic differences in protein composition affect the observed rates of racemization of the protein pool. Some weak diagenetic trends in amino acid composition and abundance may be represented in the time series of shells. These results emphasize the importance of standardization of the location from which samples are taken from shells for dating by amino acid racemization analysis.

  7. Soy-based fillers for thermoset composites

    NASA Astrophysics Data System (ADS)

    Watt, Paula

    Considerable work has been done with bio-based fillers in thermoplastics. Wood dust has been used for decades in wood plastic composites in conjunction with recycled high HDPE and PET. In recent years rapidly renewable fillers derived from dried distillery grains and from wood have been introduced commercially for thermoset polymers. These fillers provide bio-content and weight reduction to thermoset molding compounds but issues with moisture absorption and polymerization inhibition have limited their commercial acceptance. The intent of this research was to develop a bio-based filler suitable for thermoset composites. This filler would provide a low density alternative to mined mineral filler, such as CaCO3 or clay. Composites made with these fillers would be lighter in weight, which is desirable for many markets, particularly transportation. Cost parity to the mineral fillers, on a volume basis, was desirable and the use of green chemistry principles was a key objective of the project. This work provides a basis from which further development of modified soy flours as fillers for thermoset composites will continue. Biomass has been evaluated as fillers for thermoset composites since the early 1980s but failed to gain commercial acceptance due to excessive water absorption and inhibition issues with free radical curing. Biomass, with a large percentage of carbohydrates, are very hydrophilic due to their abundance of hydroxyl groups, while biomass, high in lignin, resulted in inhibition of the free radical cure of the unsaturated styrenated polyester matrix systems. Generally protein use as a filler is not desirable due to its food value. Torrefaction has proved to be a good, cost effective, process to reduce hydrophilicity of high cellulose feedstock. Surprising, however, some levels of torrefaction were found to induce the inhibition effect of the filler. Scientific inquiry into this problem proved that aromatics form during the torrefaction process and can

  8. Butter composition and texture from cows with different milk fatty acid compositions fed fish oil or roasted soybeans.

    PubMed

    Bobe, G; Zimmerman, S; Hammond, E G; Freeman, A E; Porter, P A; Luhman, C M; Beitz, D C

    2007-06-01

    Changing the milk fatty acid composition can improve the nutritional and physical properties of dairy products and their acceptability to consumers. A more healthful milk fatty acid composition can be achieved by altering the cow's diet, for example, by feeding supplemental fish oil (FO) or roasted soybeans (RSB), or by selecting cows with a more unsaturated milk fatty acid composition. We examined whether feeding supplemental FO or RSB to cows that had a more unsaturated milk fatty acid composition acted additively to produce butter with improved fatty acid composition and texture. Using a 3 x 3 Latin square design with 2 replications, we fed diets to multiparous Holstein cows (60 to 200 DIM) chosen for producing either more or less unsaturated milk fatty acid composition (n = 6 for each group) for three 3-wk periods. The control diet contained 3.7% crude fat and the 2 experimental diets contained, on a dry matter basis, 0.8% of additional lipids in the form of 0.9% of FO or 5% of RSB. The milk, collected in the third week of feeding, was used to make butter, which was analyzed for its fatty acid composition and physical properties. Dry matter intake, milk yield, and milk composition were not significantly affected by cow diet or by cow selection. Cows that produced a more unsaturated and healthful milk fat prior to the feeding study, according to a "health-promoting index" [HPI = (sum of % of unsaturated fatty acids)/ (%12:0 + 4 x %14:0 + %16:0)], maintained a higher HPI in their butter during the feeding study than did cows with a low HPI. Milk from cows fed supplemental FO or RSB yielded more unsaturated butters with a higher HPI. This butter also was softer when the cows were fed RSB. Feeding RSB to cows chosen for their high milk HPI yielded the most unsaturated butter with the highest HPI and softest texture. Thus, selecting cows with a more health-promoting milk fatty acid composition and feeding supplemental RSB can be used in combination to produce butter

  9. Amino acid composition of human milk is not unique.

    PubMed

    Davis, T A; Nguyen, H V; Garcia-Bravo, R; Fiorotto, M L; Jackson, E M; Lewis, D S; Lee, D R; Reeds, P J

    1994-07-01

    To determine whether the amino acid pattern of human milk is unique, we compared the amino acid pattern of human milk with the amino acid patterns of the milks of great apes (chimpanzee and gorilla), lower primates (baboon and rhesus monkey) and nonprimates (cow, goat, sheep, llama, pig, horse, elephant, cat and rat). Amino acid pattern was defined as the relative proportion of each amino acid (protein-bound plus free) (in mg) to the total amino acids (in g). Total amino acid concentration was lower in primate milk than in nonprimate milk. There were commonalities in the overall amino acid pattern of the milks of all species sampled; the most abundant amino acids were glutamate (plus glutamine, 20%), proline (10%) and leucine (10%). Essential amino acids were 40%, branched-chain amino acids 20%, and sulfur amino acids 4% of the total amino acids. The amino acid pattern of human milk was more similar to those of great apes than to those of lower primates. For example, cystine was higher and methionine was lower in primate milks than in nonprimate milks, and in great ape and human milks than in lower primate milks. Because the milk amino acid patterns of the human and elephant, both slow-growing species, were dissimilar, the amino acid pattern of human milk seems unrelated to growth rate.

  10. Reinforced Poly(Propylene Carbonate) Composite with Enhanced and Tunable Characteristics, an Alternative for Poly(lactic Acid).

    PubMed

    Manavitehrani, Iman; Fathi, Ali; Wang, Yiwei; Maitz, Peter K; Dehghani, Fariba

    2015-10-14

    The acidic nature of the degradation products of polyesters often leads to unpredictable clinical complications, such as necrosis of host tissues and massive immune cell invasions. In this study, poly(propylene carbonate) (PPC) and starch composite is introduced with superior characteristics as an alternative to polyester-based polymers. The degradation products of PPC-starch composites are mainly carbon dioxide and water; hence, the associated risks to the acidic degradation of polyesters are minimized. Moreover, the compression strength of PPC-starch composites can be tuned over the range of 0.2±0.03 MPa to 33.9±1.51 MPa by changing the starch contents of composites to address different clinical needs. More importantly, the addition of 50 wt % starch enhances the thermal processing capacity of the composites by elevating their decomposition temperature from 245 to 276 °C. Therefore, thermal processing methods, such as extrusion and hot melt compression methods can be used to generate different shapes and structures from PPC-starch composites. We also demonstrated the cytocompatibility and biocompatibility of these composites by conducting in vitro and in vivo tests. For instance, the numbers of osteoblast cells were increased 2.5 fold after 7 days post culture. In addition, PPC composites in subcutaneous mice model resulted in mild inflammatory responses (e.g., the formation of fibrotic tissue) that were diminished from two to 4 weeks postimplantation. The long-term in vivo biodegradation of PPC composites are compared with poly(lactic acid) (PLA). The histochemical analysis revealed that after 8 weeks, the biodegradation of PLA leads to massive immune cell infusion and inflammation at the site, whereas the PPC composites are well-tolerated in vivo. All these results underline the favorable properties of PPC-starch composites as a benign biodegradable biomaterial for fabrication of biomedical implants.

  11. Hydrofluoric acid-resistant composite window and method for its fabrication

    DOEpatents

    Ostenak, C.A.; Mackay, H.A.

    1985-07-18

    A hydrofluoric acid-resistant composite window and method for its fabrication are disclosed. The composite window comprises a window having first and second sides. The first side is oriented towards an environment containing hydrofluoric acid. An adhesive is applied to the first side. A layer of transparent hydrofluoric acid-resistant material, such as Mylar, is applied to the adhesive and completely covers the first side. The adhesive is then cured.

  12. Migration of Co-cultured Endothelial Cells and Osteoblasts in Composite Hydroxyapatite/Polylactic Acid Scaffolds

    DTIC Science & Technology

    2011-07-16

    Migration of Co-cultured Endothelial Cells and Osteoblasts in Composite Hydroxyapatite/ Polylactic Acid Scaffolds AMITA R. SHAH,1,2,3 SARITA R. SHAH,2...bone. A scaffold design consisting of a hydroxy apatite (HA) ring surrounding a polylactic acid (PLA) core simulates the structure of bone and provides...and osteoblasts in composite hydroxyapatite/ polylactic acid scaffolds. 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR

  13. Hydrofluoric acid-resistant composite window and method for its fabrication

    DOEpatents

    Ostenak, Carl A.; Mackay, Harold A.

    1987-01-01

    A hydrofluoric acid-resistant composite window and method for its fabrication are disclosed. The composite window comprises a window having first and second sides. The first side is oriented towards an environment containing hydrofluoric acid. An adhesive is applied to the first side. A layer of transparent hydrofluoric acid-resistant material, such as Mylar, is applied to the adhesive and completely covers the first side. The adhesive is then cured.

  14. Amino Acids Composition of Teucrium Nutlet Proteins and their Systematic Significance

    PubMed Central

    JUAN, R.; PASTOR, J.; MILLÁN, F.; ALAIZ, M.; VIOQUE, J.

    2004-01-01

    • Background and Aims Plant species are considered as a good source of dietary proteins, although the nutritional quality of proteins depends on their amino acid composition. In this work the protein content and amino acid composition of nutlets of 21 Teucrium taxa (Lamiaceae) from Spain were analysed and their nutritional quality was compared with the minimum values established by the Food and Agriculture Organization of the United Nations (FAO). In addition, the amino acid composition was evaluated as a chemical character to clarify the taxonomic complexity in this genus. • Methods Amino acid content of nutlets was determined after derivatization with diethyl ethoxymethylenemalonate by high-performance liquid chromatography. Previously, nutlets samples were hydrolysed and incubated in an oven at 110 °C for 24 h. • Key Results The protein content was variable, ranging from 6·4 % in T. dunense to 43·8 % in T. algarbiense. According to the FAO values all taxa contain satisfactory amounts of leucine, threonine and valine and are deficient in lysine. The similarity analysis of Teucrium taxa using amino acid composition data did not clearly reflect the infrageneric classification of this genus. • Conclusions Annual species, such as T. spinosum, T. aristatum and T. resupinatum showed a better balanced amino acid composition. The dendrogram partly matched with the karyological complexity of Teucrium. No correlation between amino acid composition and habitat has been observed, showing that Teucrium nutlet amino acid composition may not be strongly influenced by the environment. PMID:15329333

  15. Recovery of uranium from phosphoric acid medium by polymeric composite beads encapsulating organophosphorus extractants

    SciTech Connect

    Singh, D.K.; Yadav, K.K.; Varshney, L.; Singh, H.

    2013-07-01

    The present study deals with the preparation and evaluation of the poly-ethersulfone (PES) based composite beads encapsulating synergistic mixture of D2EHPA and Cyanex 923 (at 4:1 mole ratio) for the separation of uranium from phosphoric acid medium. SEM was used for the characterization of the composite materials. Addition of 1% PVA (polyvinyl alcohol) improved the internal morphology and porosity of the beads. Additionally, microscopic examination of the composite bead confirmed central coconut type cavity surrounded by porous polymer layer of the beads through which exchange of metal ions take place. Effect of various experimental variables including aqueous acidity, metal ion concentration in aqueous feed, concentration of organic extractant inside the beads, extractant to polymer ratio, liquid to solid (L/S) ratio and temperature on the extraction of uranium was studied. Increase in acidity (1-6 M), L/S ratio (1- 10), metal ion concentration (0.2-3 g/L U{sub 3}O{sub 8}) and polymer to extractant ratio (1:4 -1:10) led to decrease in extraction of uranium. At 5.5 M (comparable to wet process phosphoric acid concentration) the extraction of uranium was about 85% at L/S ratio 5. Increase in extractant concentration inside the bead resulted in enhanced extraction of metal ion. Increase in temperature in the range of 30 to 50 Celsius degrees increased the extraction, whereas further increase to 70 C degrees led to the decrease in extraction of uranium. Amongst various reagents tested, stripping of uranium was quantitative by 12% Na{sub 2}CO{sub 3} solution. Polymeric beads were found to be stable and reusable up-to 10 cycles of extraction/stripping. (authors)

  16. Acid-base thermochemistry of gaseous oxygen and sulfur substituted amino acids (Ser, Thr, Cys, Met).

    PubMed

    Riffet, Vanessa; Frison, Gilles; Bouchoux, Guy

    2011-11-07

    Acid-base thermochemistry of isolated amino acids containing oxygen or sulfur in their side chain (serine, threonine, cysteine and methionine) have been examined by quantum chemical computations. Density functional theory (DFT) was used, with B3LYP, B97-D and M06-2X functionals using the 6-31+G(d,p) basis set for geometry optimizations and the larger 6-311++G(3df,2p) basis set for energy computations. Composite methods CBS-QB3, G3B3, G4MP2 and G4 were applied to large sets of neutral, protonated and deprotonated conformers. Conformational analysis of these species, based on chemical approach and AMOEBA force field calculations, has been used to identify the lowest energy conformers and to estimate the population of conformers expected to be present at thermal equilibrium at 298 K. It is observed that G4, G4MP2, G3B3, CBS-QB3 composite methods and M06-2X DFT lead to similar conformer energies. Thermochemical parameters have been computed using either the most stable conformers or equilibrium populations of conformers. Comparison of experimental and theoretical proton affinities and Δ(acid)H shows that the G4 method provides the better agreement with deviations of less than 1.5 kJ mol(-1). From this point of view, a set of evaluated thermochemical quantities for serine, threonine, cysteine and methionine may be proposed: PA = 912, 919, 903, 938; GB = 878, 886, 870, 899; Δ(acid)H = 1393, 1391, 1396, 1411; Δ(acid)G = 1363, 1362, 1367, 1382 kJ mol(-1). This study also confirms that a non-negligible ΔpS° is associated with protonation of methionine and that the most acidic hydrogen of cysteine in the gas phase is that of the SH group. In several instances new conformers were identified thus suggesting a re-examination of several IRMPD spectra.

  17. Fatty acids composition of Spanish black (Morus nigra L.) and white (Morus alba L.) mulberries.

    PubMed

    Sánchez-Salcedo, Eva M; Sendra, Esther; Carbonell-Barrachina, Ángel A; Martínez, Juan José; Hernández, Francisca

    2016-01-01

    This research has determined qualitatively and quantitatively the fatty acids composition of white (Morus alba) and black (Morus nigra) fruits grown in Spain, in 2013 and 2014. Four clones of each species were studied. Fourteen fatty acids were identified and quantified in mulberry fruits. The most abundant fatty acids were linoleic (C18:2), palmitic (C16:0), oleic (C18:1), and stearic (C18:0) acids in both species. The main fatty acid in all clones was linoleic (C18:2), that ranged from 69.66% (MN2) to 78.02% (MA1) of the total fatty acid content; consequently Spanish mulberry fruits were found to be rich in linoleic acid, which is an essential fatty acid. The fatty acid composition of mulberries highlights the nutritional and health benefits of their consumption.

  18. Multimode model based defect characterization in composites

    NASA Astrophysics Data System (ADS)

    Roberts, R.; Holland, S.; Gregory, E.

    2016-02-01

    A newly-initiated research program for model-based defect characterization in CFRP composites is summarized. The work utilizes computational models of the interaction of NDE probing energy fields (ultrasound and thermography), to determine 1) the measured signal dependence on material and defect properties (forward problem), and 2) an assessment of performance-critical defect properties from analysis of measured NDE signals (inverse problem). Work is reported on model implementation for inspection of CFRP laminates containing delamination and porosity. Forward predictions of measurement response are presented, as well as examples of model-based inversion of measured data for the estimation of defect parameters.

  19. GLC analysis of Indian rapeseed-mustard to study the variability of fatty acid composition.

    PubMed

    Kaushik, N; Agnihotri, A

    2000-12-01

    Rapeseed-mustard is one of the most economically important oilseed crops in India. Speciality oils having high amounts of a specific fatty acid are of immense importance for both nutritional and industrial purposes. Oil high in oleic acid has demand in commercial food-service applications due to a long shelf-life and cholesterol-reducing properties. Both linoleic and linolenic acids are essential fatty acids; however, less than 3% linolenic acid is preferred for oil stability. High erucic acid content is beneficial for the polymer industry, whereas low erucic acid is recommended for food purposes. Therefore, it is important to undertake systematic characterization of the available gene pool for its variable fatty acid profile to be utilized for specific purposes. In the present study the Indian rapeseed-mustard germplasm and some newly developed low-erucic-acid strains were analysed by GLC to study the fatty acid composition in these lines. The GLC analysis revealed that the rapeseed-mustard varieties being commonly grown in India are characterized by high erucic acid content (30-51%) in the oil with low levels of oleic acid (13-23%). However, from among the recently developed low-erucic-acid strains, several lines were identified with comparatively high oleic acid (60-70%), moderate to high linoleic acid (13-40%) and low linolenic acid (< 10%) contents. Work is in progress at TERI (New Delhi, India) to utilize these lines for development of strains with particular fatty acid compositions for specific purposes.

  20. Fatty acids from seeds of Pinus pinea L.: composition and population profiling.

    PubMed

    Nasri, Nizar; Khaldi, Abdelhamid; Fady, Bruno; Triki, Saida

    2005-07-01

    Pinus pinea L. is widely disseminated all over the Mediterranean Basin. Qualitatively, P. pinea fatty acid seed composition is identical and typical of the genus Pinus. This composition is made of unsaturated oil with several unusual polymethylene-interrupted unsaturated fatty acids. Linoleic acid is the major fatty acid followed by oleic, palmitic and stearic acids. Quantitatively, for all Mediterranean populations, total amounts of fatty acids seem to be fairly constant and independent from their origin. When applying principal component analysis, it seems that there is not a distinct geographical variability. Tunisian populations appear to be integral part of the Mediterranean populations without any particular structuring. Taking into account this research and the data reported in the literature, we can confirm that P. pinea expresses no significant variability. This low genetic diversity revealed by fatty acid composition can be explained by anthropogenetic diffusion of genetically homogeneous reproductive material as early as the first explorations.

  1. Gender Differences in Rat Erythrocyte and Brain Docosahexaenoic Acid Composition: Role of Ovarian Hormones and Dietary Omega-3 Fatty Acid Composition

    PubMed Central

    McNamara, Robert K.; Able, Jessica; Jandacek, Ronald; Rider, Therese; Tso, Patrick

    2009-01-01

    The two-fold higher prevalence rate of major depression in females may involve vulnerability to omega-3 fatty acid deficiency secondary to a dysregulation in ovarian hormones. However, the role of ovarian hormones in the regulation of brain omega-3 fatty acid composition has not been directly evaluated. Here we determined erythrocyte and regional brain docosahexaenoic acid (DHA, 22:6n-3) composition in intact male and female rats, and in chronically ovariectomized (OVX) rats with or without cyclic estradiol treatment (2 μg/4 d). All groups were maintained on diets with or without the DHA precursor alpha-linolenic acid (ALA, 18:3n-3). We report that both male (−21%) and OVX (−19%) rats on ALA+ diet exhibited significantly lower erythrocyte DHA composition relative to female controls. Females on ALA+ diet exhibited lower DHA composition in the prefrontal cortex (PFC) relative males (−5%). OVX rats on ALA+ diet exhibited significantly lower DHA composition in the hippocampus (−6%), but not in the PFC, hypothalamus, or midbrain. Lower erythrocyte and hippocampus DHA composition in OVX rats was not prevented by estrogen replacement. All groups maintained on ALA− diet exhibited significantly lower erythrocyte and regional brain DHA composition relative to groups on ALA+ diet, and these reductions were greater in males but not in OVX rats. These preclinical data corroborate clinical evidence for gender differences in peripheral DHA composition (female>male), demonstrate gender differences in PFC DHA composition (male>female), and support a link between ovarian hormones and erythrocyte and region-specific brain DHA composition. PMID:19046819

  2. Resolution and quantification of isomeric fatty acids by silver ion HPLC: fatty acid composition of aniseed oil (Pimpinella anisum, Apiaceae).

    PubMed

    Denev, Roumen V; Kuzmanova, Ivalina S; Momchilova, Svetlana M; Nikolova-Damyanova, Boryana M

    2011-01-01

    A silver ion HPLC procedure is described that is suitable to determine the fatty acid composition of plant seed oils. After conversion of fatty acids to p-methoxyphenacyl derivatives, it was possible to achieve baseline resolution of all fatty acid components with 0 to 3 double bonds, including the positionally isomeric 18:1 fatty acids oleic acid (cis 9-18:1), petroselinic acid (cis 6-18:1), and cis-vaccenic acid (cis 11-18:1), in aniseed oil (Pimpinella anisum, Apiaceae) by a single gradient run on a single cation exchange column laboratory converted to the silver ion form. The UV detector response (280 nm) was linearly related to the fatty acid concentration in the range 0.01 to 3.5 mg/mL.

  3. An amperometric biosensor based on ascorbate oxidase immobilized in poly(3,4-ethylenedioxythiophene)/multi-walled carbon nanotubes composite films for the determination of L-ascorbic acid.

    PubMed

    Liu, Ming; Wen, Yangping; Xu, Jingkun; He, Haohua; Li, Dong; Yue, Ruirui; Liu, Guodong

    2011-01-01

    An amperometric L-ascorbic acid (AA) biosensor fabricated by immobilizing ascorbate oxidase (AO) in poly(3,4-ethylenedioxythiophene) (PEDOT) and multi-walled carbon nanotubes (MWCNTs) composite films was reported for the first time. The entrapment of AO in PEDOT/MWCNTs composite films was performed during an electrochemical polymerization process. The influence of various experimental conditions was examined for determining the optimum analytical performance. The response of the biosensor towards AA under the optimized conditions is linear from 0.05 to 20 mM with a detection limit of 15 µM (S/N = 3). The biosensor shows a response time of 20 s and a sensitivity of 23.95 mA M(-1) cm(-2). The apparent Michaelis-Menten constant (K(m)) and apparent activation energy (E(a)) are 19.5 mM and 21 kJ mol(-1), respectively. Moreover, the biosensor exhibits good anti-interferent ability, good reproducibility and remarkable storage stability.

  4. Fatty acid composition including cis-9, trans-11 CLA of cooked ground lamb

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little information is available on effect of cooking on beneficial fatty acids such as conjugated linoleic acid (CLA) and n-3 polyunsaturated fatty acids (PUFA). The objective of this study was to examine impact of cooking on the FA composition of ground lamb of two different muscles. Samples were p...

  5. Fatty acid composition of the red blood cell membrane in relation to menopausal status.

    PubMed

    Tworek; Muti; Micheli; Krogh; Riboli; Berrino

    2000-10-01

    PURPOSE: Menopausal status effects female anatomical functioning at a variety of system-wide and cellular levels, including cellular membrane composition. This study analyzed a nested case-control ORDET data set of 433 pre and post-menopausal breast cancer controls to examine the effects of menopausal status on the fatty acid composition of the red blood cell membrane.METHODS: ORDET is a prospective cohort study conducted in Italy to investigate the etiologic role of hormones and diet in breast cancer development. The fatty acid composition was measured and analyzed by gas chromotography, comparing retention time with standard measurement. Twenty-two individual fatty acids were measured, recorded, and categorized into four fatty acid groups: saturated, monounsaturated, polyunsaturated n-6 (PUFA n-6), and polyunsaturated (PUFA n-3) fatty acids.RESULTS: Post-menopausal women had consistently lower mean values for all four fatty acid categories and all individual fatty acids. Statistically significant mean differences, by menopausal status, were observed for three of the four fatty acid categories: saturated fatty acids (p = 0.006), PUFA n-6 acids (p = 0.001), and PUFA n-3 acids (p = 0.000). The biggest statistically significant differences in mean values among individual fatty acids for each category were observed for Palmitic acid (p = 0.009), Oleic acid (p = 0.040), Linoleic acid (p = 0.000), and Docosahexaenoic acid (p = 0.000). Individual fatty acids were also less highly correlated among post-menopausal women.CONCLUSIONS: There was an observed relationship between menopausal status and the fatty acid composition of the red blood cell membrane that warrants further study. This relationship may contribute to the physiological and psychological changes that occur during and after menopause, and may have far-reaching implications for women's health.

  6. Serum Paraoxonase 1 Activity Is Associated with Fatty Acid Composition of High Density Lipoprotein

    PubMed Central

    Boshtam, Maryam; Pourfarzam, Morteza; Ani, Mohsen; Naderi, Gholam Ali; Basati, Gholam; Mansourian, Marjan; Dinani, Narges Jafari; Asgary, Seddigheh; Abdi, Soheila

    2013-01-01

    Introduction. Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. Methods. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Results. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω6 fatty acids of HDL. Conclusion. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health. PMID:24167374

  7. Bile acid composition of gallbladder contents in dogs with gallbladder mucocele and biliary sludge.

    PubMed

    Kakimoto, Toshiaki; Kanemoto, Hideyuki; Fukushima, Kenjiro; Ohno, Koichi; Tsujimoto, Hajime

    2017-02-01

    OBJECTIVE To examine bile acid composition of gallbladder contents in dogs with gallbladder mucocele and biliary sludge. ANIMALS 18 dogs with gallbladder mucocele (GBM group), 8 dogs with immobile biliary sludge (i-BS group), 17 dogs with mobile biliary sludge (m-BS group), and 14 healthy dogs (control group). PROCEDURES Samples of gallbladder contents were obtained by use of percutaneous ultrasound-guided cholecystocentesis or during cholecystectomy or necropsy. Concentrations of 15 bile acids were determined by use of highperformance liquid chromatography, and a bile acid compositional ratio was calculated for each group. RESULTS Concentrations of most bile acids in the GBM group were significantly lower than those in the control and m-BS groups. Compositional ratio of taurodeoxycholic acid, which is 1 of 3 major bile acids in dogs, was significantly lower in the GBM and i-BS groups, compared with ratios for the control and m-BS groups. The compositional ratio of taurocholic acid was significantly higher and that of taurochenodeoxycholic acid significantly lower in the i-BS group than in the control group. CONCLUSIONS AND CLINICAL RELEVANCE In this study, concentrations and fractions of bile acids in gallbladder contents were significantly different in dogs with gallbladder mucocele or immobile biliary sludge, compared with results for healthy control dogs. Studies are needed to determine whether changes in bile acid composition are primary or secondary events of gallbladder abnormalities.

  8. Fabrication of novel calcium phosphate/poly(lactic acid) fiber composites.

    PubMed

    Kothapalli, Chandrasekhar R; Shaw, Montgomery T; Olson, James R; Wei, Mei

    2008-01-01

    Composites using high-modulus polylactic acid (PLA) fibers coated with calcium phosphate (CaP) were prepared using a cyclic precipitation technique. Scanning electron microscopy revealed that small nuclei of CaP formed after the first soaking cycle, while large quantities of CaP particles were observed after the sixth cycle. The amount of CaP deposited on the PLA yarn increased with deposition time in Ca(2+) and PO(4) (3-) solutions and number of cycles, and decreased with stirring rate during washing cycles. It was observed that around 35 wt % of CaP was deposited on the yarn surface after six cycles of cyclic-soaking. Based on the results, a heterogeneous nucleation and growth mechanism was proposed for the CaP deposition on the surface of hydrolyzed polyester. Composites comprising the coated fibers in a poly(caprolactone) matrix exhibited flexural moduli within the range of that of the cortical bone.

  9. Photocatalytic degradation of commercially sourced naphthenic acids by TiO2-graphene composite nanomaterial.

    PubMed

    Liu, Juncheng; Wang, Lin; Tang, Jingchun; Ma, Jianli

    2016-04-01

    Naphthenic acids (NAs) are a major contributor to the toxicity in oil sands process-affected water (OSPW), which is produced by hot water extraction of bitumen. NAs are extremely difficult to be degraded due to its complex ring and side chain structure. Photocatalysis is recognized as a promising technology in the removal of refractory organic pollutants. In this work, TiO2-graphene (P25-GR) composites were synthesized by means of solvothermal method. The results showed that P25-GR composite exhibited better photocatalytic activity than pure P25. The removal efficiency of naphthenic acids in acid solution was higher than that in neutral and alkaline solutions. It was the first report ever known on the photodegradation of NAs based on graphene, and this process achieved a higher removal rate than other photocatalysis degradation of NAs in a shorter reaction time. LC/MS analysis showed that macromolecular NAs (carbon number 17-22, z value -2) were easy to be degraded than the micromolecular ones (carbon number 11-16, z value -2). Furthermore, the reactive oxygen species that play the main role in the photocatalysis system were studied. It was found that holes and ·OH were the main reactive species in the UV/P25-GR photocatalysis system. Given the high removal efficiency of refractory organic pollutants and the short degradation time, photodegradation based on composite catalysts has a broad and practical prospect. The study on the photodegradation of commercially sourced NAs may provide a guidance for the degradation of OSPW NAs by this method.

  10. Composition of amino acids in feed ingredients for animal diets.

    PubMed

    Li, Xilong; Rezaei, Reza; Li, Peng; Wu, Guoyao

    2011-04-01

    Dietary amino acids (AA) are crucial for animal growth, development, reproduction, lactation, and health. However, there is a scarcity of information regarding complete composition of "nutritionally nonessential AA" (NEAA; those AA which can be synthesized by animals) in diets. To provide a much-needed database, we quantified NEAA (including glutamate, glutamine, aspartate, and asparagine) in feed ingredients for comparison with "nutritionally essential AA" (EAA; those AA whose carbon skeletons cannot be formed by animals). Except for gelatin and feather meal, animal and plant ingredients contained high percentages of glutamate plus glutamine, branched-chain AA, and aspartate plus asparagine, which were 10-32, 15-25, and 8-14% of total protein, respectively. In particular, leucine and glutamine were most abundant in blood meal and casein (13% of total protein), respectively. Notably, gelatin, feather meal, fish meal, meat and bone meal, and poultry byproduct had high percentages of glycine, proline plus hydroxyproline, and arginine, which were 10-35, 9.6-35, and 7.2-7.9% of total protein, respectively. Among plant products, arginine was most abundant in peanut meal and cottonseed meal (14-16% of total protein), whereas corn and sorghum had low percentages of cysteine, lysine, methionine, and tryptophan (0.9-3% of total protein). Overall, feed ingredients of animal origin (except for gelatin) are excellent sources of NEAA and EAA for livestock, avian, and aquatic species, whereas gelatin provides highest amounts of arginine, glycine, and proline plus hydroxyproline. Because casein, corn, soybean, peanut, fish, and gelatin are consumed by children and adults, our findings also have important implications for human nutrition.

  11. Oleic acid-grafted chitosan/graphene oxide composite coating for corrosion protection of carbon steel.

    PubMed

    Fayyad, Eman M; Sadasivuni, Kishor Kumar; Ponnamma, Deepalekshmi; Al-Maadeed, Mariam Al Ali

    2016-10-20

    An anticorrosion coating film based on the formation of nanocomposite coating is reported in this study. The composite consisted of chitosan (green matrix), oleic acid, and graphene oxide (nano filler). The nanocomposite coating was arranged on the surface of carbon steel, and the corrosion resistance was monitored using electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PP). Compared to the pure chitosan (CS) coating, the corrosion resistance of oleic acid-modified chitosan/graphene oxide film (CS/GO-OA) is increased by 100 folds. Since the well-dispersed smart grafted nanolayers delayed the penetration rate of corrosive species and thus maintained long term anticorrosive stability which is correlated with hydrophobicity and permeability.

  12. Effect of Lactic Acid on Microleakage of Class V Low-Shrinkage Composite Restorations

    PubMed Central

    Hashemikamangar, Sedigheh Sadat; Pourhashemi, Seyed Jalal; Nekooimehr, Zohre; Dehaki, Mehrzad Gholampur; Kharazifard, Mohamad Javad

    2016-01-01

    Objectives: To assess the effect of lactic acid (LA) on microleakage of silorane-based composite restorations and methacrylate-based composites with self-etch and etch-and-rinse bonding systems. Materials and Methods: Class V cavities were prepared in 120 extracted human teeth, divided into four groups and restored as follows: 1. Silorane-based composite+P90 adhesive system (P90); 2. Filtek Z250+SE Bond (Z250SE); 3. Filtek Z350+SE Bond (Z350SE) and 4. Filtek Z250+Single Bond (Z250SB). Half of the samples in each group were immersed in LA and the other half in distilled water (DW) for seven days. Degree of microleakage was determined by dye penetration. Data were analyzed using Kruskal Wallis and Mann Whitney-U tests (type 1 error was considered 0.05 for primary and 0.017 for post-hoc tests). Results: No significant difference was found in microleakage between LA and DW groups. The difference among groups in gingival margin microleakage was significant (P<0.05). The highest degree of microleakage was seen in Z250SB; which was significantly higher than Z250SE (DW: P=0.012 and LA: P=0.002) and Z350SE (DW: P=0.002 and LA: P=0.014). Microleakage was not significantly different between Z250SE and Z350SE (DW: P=0.683 and LA: P=0.533). The degree of microleakage of P90 in both media was lower than Z250SB and higher than that of Z250SE and Z350SE; but these differences were not significant. Conclusions: Immersion in LA has no effect on microleakage of class V composite restorations regardless of the type of composite and adhesive system. At gingival margins, the highest microleakage occurred in Z250SB followed by P90 and self-etch groups. PMID:28127313

  13. Cellular fatty acid composition of Actinobacillus actinomycetemcomitans and Haemophilus aphrophilus.

    PubMed Central

    Braunthal, S D; Holt, S C; Tanner, A C; Socransky, S S

    1980-01-01

    Strains of Actinobacillus actinomycetemcomitans isolated from deep pockets of patients with juvenile periodontitis were analyzed for their content of cellular fatty acids. Oral Haemophilus strains, morphologically and biochemically similar to Haemophilus aphrophilus, were also examined for their content of cellular fatty acids. The extractable lipids of the actinobacilli represented approximately 10% of the cell dry weight, with the bound lipids representing 2 to 5%. The major fatty acids consisted of myristic (C14:0) and palmitic (C16:0) acids and a C16:1 acid, possibly palmitoleic acid, accounting for 21, 35, and 31% of the total extractable fatty acids, respectively. Haemophilus strains had a similar cellular fatty acid content. PMID:7430333

  14. Application of Granulated Blast Furnace Slag in Cement Composites Exposed to Biogenic Acid Attack

    NASA Astrophysics Data System (ADS)

    Kovalcikova, M.; Estokova, A.; Luptakova, A.

    2015-11-01

    The deterioration of cement-based materials used for the civil infrastructure has led to the realization that cement-based materials, such as concrete, must be improved in terms of their properties and durability. Leaching of calcium ions increases the porosity of cement- based materials, consequently resulting in a negative effect on durability since it provides an entry for aggressive harmful ions, causing corrosion of concrete. The use supplementary cementing composite materials have been reported to improve the resistance of concrete to deterioration by aggressive chemicals. The paper is focused on the investigation of the influence of biogenic acid attack on the cement composites affected by bacteria Acidithiobacillus thiooxidans. The concrete specimens with 65 wt. % addition of antimicrobial activated granulated blast furnace slag as durability increasing factor as well as without any addition were studied. The experiments proceeded during 150 days under model laboratory conditions. The pH values and chemical composition of leachates were measured after each 30- day cycle. The calcium and silicon contents in leachates were evaluated using X - ray fluorescence method (XRF). Summarizing the results, the 65% wt. addition of antimicrobial activated granulated blast furnace slag was not confirmed to be more resistant.

  15. A 3D POM-MOF composite based on Ni(ΙΙ) ion and 2,2‧-bipyridyl-3,3‧-dicarboxylic acid: Crystal structure and proton conductivity

    NASA Astrophysics Data System (ADS)

    Wei, Meilin; Wang, Xiaoxiang; Sun, Jingjing; Duan, Xianying

    2013-06-01

    We have succeeded in constructing a 3D POM-MOF, {H[Ni(Hbpdc)(H2O)2]2[PW12O40]·8H2O}n (H2bpdc=2,2'-bipyridyl-3,3'-dicarboxylic acid), by the controllable self-assembly of H2bpdc, Keggin-anions and Ni2+ ions based on the electrostatic and coordination interactions. Interestingly, Hbpdc- as polydentate organic ligands and Keggin-anion as polydentate inorganic ligands are covalently linked transition-metal nickel at the same time. The title complex represents a new example of introducing the metal N-heterocyclic multi-carboxylic acid frameworks into POMs chemistry. Based on Keggin-anions being immobilized as part of the metal N-heterocyclic multi-carboxylic acid framework, the title complex realizes four approaches in the 1D hydrophilic channel used to engender proton conductivity in MOFs. Its water adsorption isotherm at room temperature and pressure shows that the water content in it was 31 cm3 g-1 at the maximum allowable humidity, corresponding to 3.7 water molecules per unit formula. It exhibits good proton conductivities (10-4-10-3 S cm-1) at 100 °C in the relative humidity range 35-98%. The corresponding activation energy (Ea) of conductivity was estimated to be 1.01 eV.

  16. Nickel-cadmium batteries: effect of electrode phase composition on acid leaching process.

    PubMed

    Nogueira, C A; Margarido, F

    2012-01-01

    At the end of their life, Ni-Cd batteries cause a number of environmental problems because of the heavy metals they contain. Because of this, recycling of Ni-Cd batteries has been carried out by dedicated companies using, normally, pyrometallurgical technologies. As an alternative, hydrometallurgical processes have been developed based on leaching operations using several types of leachants. The effect of factors like temperature, acid concentration, reaction time, stirring speed and grinding of material on the leaching yields of metals contained in anodic and cathodic materials (nickel, cadmium and cobalt) using sulphuric acid, is herein explained based on the structural composition of the electrode materials. The nickel, cobalt and cadmium hydroxide phases, even with a small reaction time (less than 15 minutes) and low temperature (50 degrees C) and acid concentration (1.1 M H2SO4), were efficiently leached. However, leaching of the nickel metallic phase was more difficult, requiring higher values of temperature, acid concentration and reaction time (e.g. 85 degrees C, 1.1 M H2SO4 and 5 h, respectively) in order to obtain a good leaching efficiency for anodic and cathodic materials (70% and 93% respectively). The stirring speed was not significant, whereas the grinding of electrode materials seems to promote the compaction of particles, which appears to be critical in the leaching of Ni degrees. These results allowed the identification and understanding of the relationship between the structural composition of electrode materials and the most important factors that affect the H2SO4 leaching of spent Ni-Cd battery electrodes, in order to obtain better metal-recovery efficiency.

  17. Fish meal supplementation increases bovine plasma and luteal tissue omega-3 fatty acid composition.

    PubMed

    White, N R; Burns, P D; Cheatham, R D; Romero, R M; Nozykowski, J P; Bruemmer, J E; Engle, T E

    2012-03-01

    The objective of this experiment was to determine if dietary inclusion of fish meal would increase plasma and luteal tissue concentrations of eicosapentaenoic and docosahexaenoic acids. Seventeen nonlactating Angus cows (2 to 8 yr of age) were housed in individual pens and fed a corn silage-based diet for approximately 60 d. Diets were supplemented with fish meal at 5% DMI (a rich source of eicosapentaenoic acid and docosahexaenoic acid; n = 9 cows) or corn gluten meal at 6% DMI (n = 8 cows). Body weights and jugular blood samples were collected immediately before the initiation of supplementation and every 7 d thereafter for 56 d to monitor plasma n-3 fatty acid composition and BW. Estrous cycles were synchronized using 2 injections of PGF(2α) administered at 14-d intervals. The ovary bearing the corpus luteum was surgically removed at midcycle (between d 10 and 12) after estrus synchronization, which corresponded to approximately d 60 of supplementation. The ovary was transported to the laboratory, and approximately 1.5 g of luteal tissue was stored at -80°C until analyzed for n-3 fatty acid content. Initial and ending BW did not differ (P > 0.10) between cows supplemented with fish meal and those with corn gluten meal. Plasma eicosapentaenoic acid was greater (P < 0.05) beginning at d 7 of supplementation and docosahexaenoic was greater (P < 0.05) beginning at d 14 of supplementation for cows receiving fish meal. Luteal tissue collected from fish meal-supplemented cows had greater (P < 0.05) luteal n-3 fatty acids and reduced (P < 0.05) arachidonic acid and n-6 to n-3 ratio as compared with tissue obtained from cows supplemented with corn gluten meal. Our data show that fish meal supplementation increases luteal n-3 fatty acid content and reduces available arachidonic acid content, the precursor for PGF(2α). The increase in luteal n-3 fatty acids may reduce PGF(2α) intraluteal synthesis after breeding resulting in increased fertility in cattle.

  18. Fatty acid composition of seed oils from sixAdansonia species with particular reference to cyclopropane and cyclopropene acids.

    PubMed

    Ralaimanarivo, A; Gaydou, E M; Bianchini, J P

    1982-01-01

    The oil content of sixAdansonia species (Bombacaceae family) of Madagascar (Adansonia grandidieri, A. za, A. digitata, A. fony, A. madagascariensis andA. suarenzensis) and Africa (A. digitata) ranges from 8 to 46%. All the oils give a positive response to the Halphen test. Malvalic, sterculic and dihydrosterculic acids were detected using gas liquid chromatography-mass spectrometry (GLC-MS). Epoxy or hydroxy fatty acids were not found in these oils. Fatty acid composition was determined by GLC using glass capillary columns coated with BDS and Carbowax 20 M. Results obtained for cyclopropenic fatty acids (CPEFA) were compared to those given by glass capillary GLC after derivatization with silver nitrate in methanol, by hydrogen bromide titration and by proton magnetic resonance (PMR). Good agreement was observed for the results given by the various methods. Malvalic acid content ranges from 3 to 28%, sterculic acid from 1 to 8% and dihydrosterculic acid from 1.5 to 5.1%. Odd-numbered fatty acids (Pentadecanoic and hepatadecanoic) were also observed in minute amounts (0.1-1.1%). Among the normal fatty acids, we observed mainly palmitic (21-46%), oleic (15-40%) and linoleic (12-32%). The relationship between fatty acid composition andAdansonia species is discussed.

  19. Fermentation based carbon nanotube multifunctional bionic composites

    NASA Astrophysics Data System (ADS)

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-06-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal.

  20. Fermentation based carbon nanotube multifunctional bionic composites

    PubMed Central

    Valentini, Luca; Bon, Silvia Bittolo; Signetti, Stefano; Tripathi, Manoj; Iacob, Erica; Pugno, Nicola M.

    2016-01-01

    The exploitation of the processes used by microorganisms to digest nutrients for their growth can be a viable method for the formation of a wide range of so called biogenic materials that have unique properties that are not produced by abiotic processes. Here we produced living hybrid materials by giving to unicellular organisms the nutrient to grow. Based on bread fermentation, a bionic composite made of carbon nanotubes (CNTs) and a single-cell fungi, the Saccharomyces cerevisiae yeast extract, was prepared by fermentation of such microorganisms at room temperature. Scanning electron microscopy analysis suggests that the CNTs were internalized by the cell after fermentation bridging the cells. Tensile tests on dried composite films have been rationalized in terms of a CNT cell bridging mechanism where the strongly enhanced strength of the composite is governed by the adhesion energy between the bridging carbon nanotubes and the matrix. The addition of CNTs also significantly improved the electrical conductivity along with a higher photoconductive activity. The proposed process could lead to the development of more complex and interactive structures programmed to self-assemble into specific patterns, such as those on strain or light sensors that could sense damage or convert light stimulus in an electrical signal. PMID:27279425

  1. A comparative study of the fatty acid composition of prochloron lipids

    NASA Technical Reports Server (NTRS)

    Kenrick, J. R.; Deane, E. M.; Bishop, D. G.

    1983-01-01

    The chemical analysis of lipids of Prochloron isolated from several hosts is discussed. The object was to determine whether differences in lipid composition could be used to characterize organisms from different sources. Major lipid components are given. An analysis of fatty acid composition of individual lipids slowed a distinctive disstribution of fatty acids. While present results do not justify the use of fatty acid content in the taxonomy of Prochlon, the variations found in the lipids of cells from the same host harvested from different areas, or at different times in the same area, suggest that a study of the effects of temperature and light intensity on lipid composition would be rewarding.

  2. Proximate composition, fatty acid analysis and protein digestibility-corrected amino acid score of three Mediterranean cephalopods.

    PubMed

    Zlatanos, Spiros; Laskaridis, Kostas; Feist, Christian; Sagredos, Angelos

    2006-10-01

    Proximate composition, fatty acid analysis and protein digestibility-corrected amino acid score (PDCAAS) in three commercially important cephalopods of the Mediterranean sea (cuttlefish, octopus and squid) were determined. The results of the proximate analysis showed that these species had very high protein:fat ratios similar to lean beef. Docosahexaenoic, palmitic and eicosipentaenoic acid were the most abundant fatty acids among analyzed species. The amount of n-3 fatty acids was higher than that of saturated, monounsaturated and n-6 fatty acids. Despite the fact that cephalopods contain small amounts of fat they were found quite rich in n-3 fatty acids. Finally, PDCAAS indicated that these organisms had a very good protein quality.

  3. Effects of different dietary lipid sources on growth performance and tissue fatty acid composition of juvenile swimming crab Portunus trituberculatus

    NASA Astrophysics Data System (ADS)

    Han, Tao; Wang, Jiteng; Hu, Shuixin; Li, Xinyu; Jiang, Yudong; Wang, Chunlin

    2015-07-01

    This study was conducted to evaluate the effects of dietary lipid sources on the growth performance and fatty acid composition of the swimming crab, Portunus trituberculatus. Four isonitrogenous and isoenergetic experimental diets were formulated to contain four separate lipid sources, including fish, soybean, rapeseed, and linseed oils (FO, SO, RO, and LO, respectively). With three replicates of 18 crabs each for each diet, crabs (initial body weight, 17.00±0.09 g) were fed twice daily for 8 weeks. There were no significant differences among these groups in terms of weight gain, specific growth rate, and hepatosomatic index. However, the RO groups' survival rate was significantly lower than FO groups. The feed conversion and protein efficiency ratios of RO groups were poorer than other groups. The proximate compositions of whole body and hepatopancreas were significantly affected by these dietary treatments. Tissue fatty acid composition mainly reflected dietary fatty acid compositions. Crabs fed FO diets exhibited significantly higher arachidonic, eicosapentaenoic, and docosahexaenoic acid contents in muscle and hepatopancreas compared with VO crabs. Linoleic, oleic, and linolenic acids in muscle and hepatopancreas were the highest in the SO, RO, and LO groups, respectively. The present study suggested that SO and LO could substitute for FO in fishmeal-based diets for swimming crabs, without affecting growth performance and survival.

  4. Model based defect characterization in composites

    NASA Astrophysics Data System (ADS)

    Roberts, R.; Holland, S.

    2017-02-01

    Work is reported on model-based defect characterization in CFRP composites. The work utilizes computational models of the interaction of NDE probing energy fields (ultrasound and thermography), to determine 1) the measured signal dependence on material and defect properties (forward problem), and 2) an assessment of performance-critical defect properties from analysis of measured NDE signals (inverse problem). Work is reported on model implementation for inspection of CFRP laminates containing multi-ply impact-induced delamination, with application in this paper focusing on ultrasound. A companion paper in these proceedings summarizes corresponding activity in thermography. Inversion of ultrasound data is demonstrated showing the quantitative extraction of damage properties.

  5. Compositions and method for controlling precipitation when acidizing sour wells

    SciTech Connect

    Dill, W.R.; Walker, M.L.

    1990-08-21

    This patent describes a method of treating a sour well penetrating a subterranean formation. It comprises: introducing into the well a treating fluid comprising an acid solution having a pH below 1.9, an iron sequestering agent comprising at least one compound selected from the group consisting of aminopolycarboxylic acids, hydroxycarboxylic acids, cyclic polyethers and derivatives of the acids and ethers, present in an amount of from about 0.25 to about 5 percent by weight of the acid solution, and a sulfide modifier comprising at least one compound selected from the group consisting of an aldehyde, acetal, hemiacetal and any other compound capable of forming aldehydes in the acid solution, present in an amount of from about 0.25 to about 5 percent of the acid solution; and treating the subterranean formation with the treating fluid.

  6. Effect of Growth on Fatty Acid Composition of Total Intramuscular Lipid and Phospholipids in Ira Rabbits.

    PubMed

    Xue, Shan; He, Zhifei; Lu, Jingzhi; Tao, Xiaoqi; Zheng, Li; Xie, Yuejie; Xiao, Xia; Peng, Rong; Li, Hongjun

    2015-01-01

    The changes in fatty acid composition of total intramuscular lipid and phospholipids were investigated in the longissimus dorsi, left-hind leg muscle, and abdominal muscle of male Ira rabbits. Changes were monitored at 35, 45, 60, 75, and 90 d. Analysis using gas chromatography identified 21 types of fatty acids. Results showed that the intramuscular lipid increased and the intramuscular phospholipids (total intramuscular lipid %) decreased in all muscles with increasing age (p<0.05). An abundant amount of unsaturated fatty acids, especially polyunsaturated fatty acids, was distributed in male Ira rabbits at different ages and muscles. Palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), linoleic acid (C18:2), and arachidonic acid (C20:4) were the major fatty acids, which account to the dynamic changes of the n-6/n-3 value in Ira rabbit meat.

  7. Three-Year Breeding Cycle of Rainbow Trout (Oncorhynchus mykiss) Fed a Plant-Based Diet, Totally Free of Marine Resources: Consequences for Reproduction, Fatty Acid Composition and Progeny Survival

    PubMed Central

    Lazzarotto, Viviana; Corraze, Geneviève; Leprevost, Amandine; Quillet, Edwige; Dupont-Nivet, Mathilde; Médale, Françoise

    2015-01-01

    Terrestrial plant resources are increasingly used as substitutes for fish meal and fish oil in fish feed in order to reduce the reliance of aquaculture on marine fishery resources. Although many studies have been conducted to assess the effects of such nutritional transition, no whole breeding cycles of fish fed diets free from marine resources has been reported to date. We therefore studied the reproductive performance of trout after a complete cycle of breeding while consuming a diet totally devoid of marine ingredients and thus of n-3 long chain polyunsaturated fatty acids (n-3 LC-PUFAs) that play a major role in the formation of ova. Two groups of female rainbow trout were fed from first feeding either a commercial diet (C, marine and plant ingredients), or a 100% plant-based diet (V, blend of plant proteins and vegetable oils). Livers, viscera, carcasses and ova were sampled at spawning and analyzed for lipids and fatty acids. Although the V-diet was devoid of n-3 LC-PUFAs, significant amounts of EPA and DHA were found in livers and ova, demonstrating efficient bioconversion of linolenic acid and selective orientation towards the ova. Some ova were fertilized to assess the reproductive performance and offspring survival. We observed for the first time that trout fed a 100% plant-based diet over a 3-year breeding cycle were able to produce ova and viable alevins, although the ova were smaller. The survival of offspring from V-fed females was lower (-22%) at first spawning, but not at the second. Our study showed that, in addition to being able to grow on a plant-based diet, rainbow trout reared entirely on such a diet can successfully produce ova in which neo-synthesized n-3 LC-PUFAs are accumulated, leading to viable offspring. However, further adjustment of the feed formula is still needed to optimize reproductive performance. PMID:25658483

  8. Three-year breeding cycle of rainbow trout (Oncorhynchus mykiss) fed a plant-based diet, totally free of marine resources: consequences for reproduction, fatty acid composition and progeny survival.

    PubMed

    Lazzarotto, Viviana; Corraze, Geneviève; Leprevost, Amandine; Quillet, Edwige; Dupont-Nivet, Mathilde; Médale, Françoise

    2015-01-01

    Terrestrial plant resources are increasingly used as substitutes for fish meal and fish oil in fish feed in order to reduce the reliance of aquaculture on marine fishery resources. Although many studies have been conducted to assess the effects of such nutritional transition, no whole breeding cycles of fish fed diets free from marine resources has been reported to date. We therefore studied the reproductive performance of trout after a complete cycle of breeding while consuming a diet totally devoid of marine ingredients and thus of n-3 long chain polyunsaturated fatty acids (n-3 LC-PUFAs) that play a major role in the formation of ova. Two groups of female rainbow trout were fed from first feeding either a commercial diet (C, marine and plant ingredients), or a 100% plant-based diet (V, blend of plant proteins and vegetable oils). Livers, viscera, carcasses and ova were sampled at spawning and analyzed for lipids and fatty acids. Although the V-diet was devoid of n-3 LC-PUFAs, significant amounts of EPA and DHA were found in livers and ova, demonstrating efficient bioconversion of linolenic acid and selective orientation towards the ova. Some ova were fertilized to assess the reproductive performance and offspring survival. We observed for the first time that trout fed a 100% plant-based diet over a 3-year breeding cycle were able to produce ova and viable alevins, although the ova were smaller. The survival of offspring from V-fed females was lower (-22%) at first spawning, but not at the second. Our study showed that, in addition to being able to grow on a plant-based diet, rainbow trout reared entirely on such a diet can successfully produce ova in which neo-synthesized n-3 LC-PUFAs are accumulated, leading to viable offspring. However, further adjustment of the feed formula is still needed to optimize reproductive performance.

  9. Fatty acid composition of the estuarine amphipod, Melita plumulosa (Zeidler): link between diet and fecundity.

    PubMed

    Hyne, Ross V; Sánchez-Bayo, Francisco; Bryan, Ashley D; Johnston, Emma L; Mann, Reinier M

    2009-01-01

    The influence of various diets on the survival, fecundity, and the polyunsaturated fatty acid (PUFA) composition of the benthic estuarine amphipod Melita plumulosa (Zeidler) in laboratory cultures were determined. Apart from a natural silty sediment, six commercial food supplements were examined: an omega-6 PUFA enriched Spirulina-based dry powder, Sera micron; a shrimp-based pellet food; an omega-3 PUFA enriched algal paste, Rotiselco-ALG; an omega-6 PUFA enriched algal dry powder, AlgaMac-ARA (arachidonic acid); flaxseed meal; and an omega-3 PUFA enriched dry powder, Frippak. We have previously established that M. plumulosa cultures perform poorly and eventually decline if provided with silty sediment alone, but will thrive if supplemented with Sera micron. Conversely, if the amphipods are cultured on a nutrient-depleted sand substrate, Sera micron alone does not constitute an adequate feed. The major difference in the fatty acid composition of M. plumulosa cultured on silty sediment compared to amphipods cultured on a sand substrate and both fed Sera micron was an increase in the ratio of omega-3 to omega-6 PUFAs, indicating that the silty sediment provides additional food sources rich in omega-3 PUFAs. Furthermore, amphipods cultured in sand and fed any of the three algal-based foods or the Frippak powder as the sole food source had poor survival rates, although Sera micron maintained the best survival-this was attributed to it containing high amounts of beta-carotene and terpenoids. Melita plumulosa fed a mixture of Sera micron in conjunction with the omega-3 PUFA enriched Rotiselco-ALG and cultured on a silty substrate were found to have good fecundity with low variability.

  10. Highly sensitive and selective dopamine biosensor based on 3,4,9,10-perylene tetracarboxylic acid functionalized graphene sheets/multi-wall carbon nanotubes/ionic liquid composite film modified electrode.

    PubMed

    Niu, Xiuli; Yang, Wu; Guo, Hao; Ren, Jie; Gao, Jinzhang

    2013-03-15

    A sensitive and selective electrochemical sensor for determination of dopamine (DA) was fabricated based on 3,4,9,10-perylene tetracarboxylic acid functionalized graphene sheets, multi-wall carbon nanotubes and ionic liquid modified glass carbon electrode and the properties of modified electrode were characterized by scanning electron microscopy, transmission electron microscope and electrochemical impedance spectroscopy. The modified electrode showed excellent electrocatalytic activity toward the oxidation of DA. Meanwhile, a possible reaction mechanism related to the oxidation of DA was proposed. The differential pulse voltammetry was used for the determination of DA in the presence of 500 μM ascorbic acid and 330 μM uric acid under the optimum conditions and a good linear relationship between peak current and the concentration of DA was obtained in the concentration range from 0.03 μM to 3.82 mM with a detection limit of 1.2×10(-9) M (S/N=3). Moreover, the proposed method was successfully applied to determine DA in real sample and satisfactory results were obtained. The results showed that the modified electrode exhibits an excellent catalytic activity, good sensitivity, reproducibility and long-term stability.

  11. Ammonia Gas Sensing Behavior of Tanninsulfonic Acid Doped Polyaniline-TiO2 Composite

    PubMed Central

    Bairi, Venu Gopal; Bourdo, Shawn E.; Sacre, Nicolas; Nair, Dev; Berry, Brian C.; Biris, Alexandru S.; Viswanathan, Tito

    2015-01-01

    A highly active tannin doped polyaniline-TiO2 composite ammonia gas sensor was developed and the mechanism behind the gas sensing activity was reported for the first time. A tanninsulfonic acid doped polyaniline (TANIPANI)-titanium dioxide nanocomposite was synthesized by an in situ polymerization of aniline in the presence of tanninsulfonic acid and titanium dioxide nanoparticles. X-ray diffraction and thermogravimetric analysis were utilized to determine the incorporation of TiO2 in TANIPANI matrix. UV-Visible and infrared spectroscopy studies provided information about the electronic interactions among tannin, polyaniline, and TiO2. Scanning electron microscopy (SEM) along with energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM) surface analysis techniques were used to investigate the metal oxide dispersions inside polyaniline matrix. Gas sensors were prepared by spin coating solutions of TANIPANI-TiO2 and TANIPANI composites onto glass slides. Sensors were tested at three different concentrations (20 ppm, 40 ppm, and 60 ppm) of ammonia gas at ambient temperature conditions by measuring the changes in surface resistivity of the films with respect to time. Ammonia gas sensing plots are presented showing the response values, response times and recovery times. The TANIPANI-TiO2 composite exhibited better response and shorter recovery times when compared to TANIPANI control and other polyaniline composites that have been reported in the literature. For the first time a proposed mechanism of gas sensing basing on the polaron band localization and its effects on the gas sensing behavior of polyaniline are reported. PMID:26501291

  12. Novel composite material polyoxovanadate@MIL-101(Cr): a highly efficient electrocatalyst for ascorbic acid oxidation.

    PubMed

    Fernandes, Diana M; Barbosa, André D S; Pires, João; Balula, Salete S; Cunha-Silva, Luís; Freire, Cristina

    2013-12-26

    A novel hybrid composite material, PMo10V2@MIL-101 was prepared by the encapsulation of the tetra-butylammonium (TBA) salt of the vanadium-substituted phosphomolybdate [PMo10V2O40](5-) (PMo10V2) into the porous metal-organic framework (MOF) MIL-101(Cr). The materials characterization by powder X-ray diffraction, Fourier transform infrared spectra and scanning electron microscopy confirmed the preparation of the composite material without disruption of the MOF porous structure. Pyrolytic graphite electrodes modified with the original components (MIL-101(Cr), PMo10V2), and the composite material PMo10V2@MIL-101 were prepared and their electrochemical responses were studied by cyclic voltammetry. Surface confined redox processes were observed for all the immobilized materials. MIL-101(Cr) showed one-electron reduction process due to chromium centers (Cr(III) → Cr(II)), while PMo10V2 presented five reduction processes: the peak at more positive potentials is attributed to two superimposed 1-electron vanadium reduction processes (V(V) → V(IV)) and the other four peaks to Mo-centred two-electron reduction processes (Mo(VI) → Mo(V)). The electrochemical behavior of the composite material PMo10V2@MIL-101 showed both MIL-101(Cr) and PMo10V2 redox features, although with the splitting of the two vanadium processes and the shift of the Mo- and Cr- centered processes to more negative potentials. Finally, PMo10V2@MIL-101 modified electrode showed outstanding enhanced vanadium-based electrocatalytic properties towards ascorbic acid oxidation, in comparison with the free PMo10V2, as a result of its immobilization into the porous structure of the MOF. Furthermore, PMo10V2@MIL-101 modified electrode showed successful simultaneous detection of ascorbic acid and dopamine.

  13. Jigsaw Cooperative Learning: Acid-Base Theories

    ERIC Educational Resources Information Center

    Tarhan, Leman; Sesen, Burcin Acar

    2012-01-01

    This study focused on investigating the effectiveness of jigsaw cooperative learning instruction on first-year undergraduates' understanding of acid-base theories. Undergraduates' opinions about jigsaw cooperative learning instruction were also investigated. The participants of this study were 38 first-year undergraduates in chemistry education…

  14. Separation of Acids, Bases, and Neutral Compounds

    NASA Astrophysics Data System (ADS)

    Fujita, Megumi; Mah, Helen M.; Sgarbi, Paulo W. M.; Lall, Manjinder S.; Ly, Tai Wei; Browne, Lois M.

    2003-01-01

    Separation of Acids, Bases, and Neutral Compounds requires the following software, which is available for free download from the Internet: Netscape Navigator, version 4.75 or higher, or Microsoft Internet Explorer, version 5.0 or higher; Chime plug-in, version compatible with your OS and browser (available from MDL); and Flash player, version 5 or higher (available from Macromedia).

  15. Has resin-based composite replaced amalgam?

    PubMed

    Christensen, Gordon J; Child, Paul L

    2010-02-01

    The major health organizations in the world continue to accept amalgam use, but the "amalgam war" of the 1800s is still going on. The end is not in sight. There is little disagreement that amalgam serves well and, although controversial, it appears to have minimal to no health hazards. There is a wide variation in the relative amount of amalgam placed in developed countries, and many dentists in North America do not use it. However, amalgam is still being used at least some of the time by the majority of practitioners in North America, and most of those practitioners also place resin-based composite in Class II locations. The evolution from amalgam to tooth-colored restorations has been a slow and tumultuous journey. The acceptability of resin-based composite in Class II locations continues to be a question for some dentists, while others have concluded that amalgam is "dead." It would be highly desirable if some of dentists using the alleged poisonous properties of amalgam as a "practice building" ploy would find more legitimate methods to increase their practice activity.

  16. Erythrocyte Membrane Fatty Acid Composition in Premenopausal Patients with Iron Deficiency Anemia.

    PubMed

    Aktas, Mehmet; Elmastas, Mahfuz; Ozcicek, Fatih; Yilmaz, Necmettin

    2016-01-01

    Iron deficiency anemia (IDA) is one of the most common nutritional disorders in the world. In the present study, we evaluated erythrocyte membrane fatty acid composition in premenopausal patients with IDA. Blood samples of 102 premenopausal women and 88 healthy control subjects were collected. After the erythrocytes were separated from the blood samples, the membrane lipids were carefully extracted, and the various membrane fatty acids were measured by gas chromatography (GC). Statistical analyses were performed with the SPSS software program. We used blood ferritin concentration <15 ng/mL as cut-off for the diagnosis of IDA. The five most abundant individual fatty acids obtained were palmitic acid (16:0), oleic acid (18:1, n-9c), linoleic acid (18:2, n-6c), stearic acid (18:0), and erucic acid (C22:1, n-9c). These compounds constituted about 87% of the total membrane fatty acids in patients with IDA, and 79% of the total membrane fatty acids in the control group. Compared with control subjects, case patients had higher percentages of palmitic acid (29.9% case versus 25.3% control), oleic acid (16.8% case versus 15.1% control), and stearic acid (13.5% case versus 10.5% control), and lower percentages of erucic acid (11.5% case versus 13.6% control) and linoleic acid (15.2% case versus 15.4% control) in their erythrocyte membranes. In conclusion, the total-erythrocyte-membrane saturated fatty acid (SFA) composition in premenopausal women with IDA was found to be higher than that in the control group; however, the total-erythrocyte-membrane unsaturated fatty acid (UFA) composition in premenopausal women with IDA was found to be lower than that in the control group. The differences in these values were statistically significant.

  17. Permeability of rayon based polymer composites

    NASA Technical Reports Server (NTRS)

    Stokes, E. H.

    1992-01-01

    Several types of anomalous rayon based phenolic behavior have been observed in post-fired nozzles and exit cones. Many of these events have been shown to be related to the development of internal gas pressure within the material. The development of internal gas pressure is a function of the amount of gas produced within the material and the rate at which that gas is allowed to escape. The latter property of the material is referred to as the material's permeability. The permeability of two dimensional carbonized rayon based phenolic composites is a function of material direction, temperature, and stress/strain state. Recently significant differences in the permeability of these materials has been uncovered which may explain their inconsistent performance. This paper summarizes what is known about the permeability of these materials to date and gives possible implications of these finding to the performance of these materials in an ablative environment.

  18. Fatty acid composition of Euphausia superba, Thysanoessa macrura and Euphausia crystallorophias collected from Prydz Bay, Antarctica

    NASA Astrophysics Data System (ADS)

    Yang, Guang; Li, Chaolun; Wang, Yanqing

    2016-04-01

    The information of trophic relationship is important for studying the Southern Ocean ecosystems. In this study, three dominant krill species, Euphausia superba, Thysanoessa macrura and Euphausia crystallorophias, were collected from Prydz Bay, Antarctica, during austral summer of 2009/2010. The composition of fatty acids in these species was studied. E. superba and T. macrura showed a similar fatty acid composition which was dominated by C14:0, C16:0, EPA (eicosapentenoic acid) and DHA (decosahexenoic acid) while E. crystallorophias showed higher contents of C18:1(n-9), C18:1(n-7), DHA and EPA than the former two. Higher fatty acid ratios of C18:1(n-9)/18:1(n-7), PUFA (polyunsaturated fatty acid)/SFA (saturated fatty acid), and 18PUFA/16PUFA indicated that E. crystallorophias should be classified as a typical omnivore with a higher trophic position compared with E. superba and T. macrura.

  19. Oil content and fatty acid composition of eggs cooked in drying oven, microwave and pan.

    PubMed

    Juhaimi, Fahad Al; Uslu, Nurhan; Özcan, Mehmet Musa

    2017-01-01

    In this study, the effect of heating on the oil yield and fatty acid composition of eggs cooked in drying oven, microwave oven, pan and boiled were determined, and compared. The highest oil content (15.22%) was observed for egg cooked in drying oven, while the lowest oil (5.195%) in egg cooked in pan. The cooking in microwave oven caused a decrease in oleic acid content (46.201%) and an increase in the amount of palmitic acid content (26.862%). In addition, the maximum oleic acid (65.837%) and minimum palmitic acid (14.015%) contents were observed in egg oil cooked in pan. Results showed that fatty acids were significantly affected by cooking method. This study confirms that the cooking processing influences the fatty acid composition of egg oils.

  20. Fatty acid composition as a tool for screening alternative feedstocks for production of biodiesel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acid (FA) composition was used as a screening tool for the selection of feedstocks high in monounsaturated content for evaluation as biodiesel. The feedstocks were ailanthus (Ailanthus altissima), anise (Pimpinella anisum), arugula (Eruca vesicaria), camelina (Camelina sativa), coriander (Cori...

  1. Determination of fatty acid composition and quality characteristics of oils from palm fruits using solvent extraction

    NASA Astrophysics Data System (ADS)

    Kasmin, Hasimah; Lazim, Azwan Mat; Awang, Roila

    2015-09-01

    Palm oil contains about 45% of saturated palmitic acid and 39% of mono-unsaturated oleic acid. Investigations made in the past to trace the fatty acid composition in palm revealed that ripeness of fresh fruit bunch (FFB) affect oil composition. However, there is no evidence that processing operations affect oil composition, although different stage of processing does affect the quality of oil extracted. An improved method for sterilizing the oil palm fruits by dry heating, followed by oil extraction has been studied. This method eliminates the use of water, thus, increasing the extraction of lipid soluble. The objective of this study is to determine the possibility production of palm oil with different fatty acid composition (FAC) as well as the changes in quality from conventional milling. The unripe and ripe FFB were collected, sterilized and extracted using different method of solvent extraction. Preliminary data have shown that variation in FAC will also alter the physical and chemical properties of the oil extracted.

  2. The effects of borate minerals on the synthesis of nucleic acid bases, amino acids and biogenic carboxylic acids from formamide.

    PubMed

    Saladino, Raffaele; Barontini, Maurizio; Cossetti, Cristina; Di Mauro, Ernesto; Crestini, Claudia

    2011-08-01

    The thermal condensation of formamide in the presence of mineral borates is reported. The products afforded are precursors of nucleic acids, amino acids derivatives and carboxylic acids. The efficiency and the selectivity of the reaction was studied in relation to the elemental composition of the 18 minerals analyzed. The possibility of synthesizing at the same time building blocks of both genetic and metabolic apparatuses, along with the production of amino acids, highlights the interest of the formamide/borate system in prebiotic chemistry.

  3. Robustness of two-step acid hydrolysis procedure for composition analysis of poplar.

    PubMed

    Bhagia, Samarthya; Nunez, Angelica; Wyman, Charles E; Kumar, Rajeev

    2016-09-01

    The NREL standard procedure for lignocellulosic biomass composition has two steps: primary hydrolysis in 72% wt sulfuric acid at 30°C for 1h followed by secondary hydrolysis of the slurry in 4wt% acid at 121°C for 1h. Although pointed out in the NREL procedure, the impact of particle size on composition has never been shown. In addition, the effects of primary hydrolysis time and separation of solids prior to secondary hydrolysis on composition have never been shown. Using poplar, it was found that particle sizes less than 0.250mm significantly lowered the glucan content and increased the Klason lignin but did not affect xylan, acetate, or acid soluble lignin contents. Composition was unaffected for primary hydrolysis time between 30 and 90min. Moreover, separating solids prior to secondary hydrolysis had negligible effect on composition suggesting that lignin and polysaccharides are completely separated in the primary hydrolysis stage.

  4. Associations between plasma branched-chain amino acids, β-aminoisobutyric acid and body composition.

    PubMed

    Rietman, Annemarie; Stanley, Takara L; Clish, Clary; Mootha, Vamsi; Mensink, Marco; Grinspoon, Steven K; Makimura, Hideo

    2016-01-01

    Plasma branched-chain amino acids (BCAA) are elevated in obesity and associated with increased cardiometabolic risk. β-Aminoisobutyric acid (B-AIBA), a recently identified small molecule metabolite, is associated with decreased cardiometabolic risk. Therefore, we investigated the association of BCAA and B-AIBA with each other and with detailed body composition parameters, including abdominal visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). A cross-sectional study was carried out with lean (n 15) and obese (n 33) men and women. Detailed metabolic evaluations, including measures of body composition, insulin sensitivity and plasma metabolomics were completed. Plasma BCAA were higher (1·6 (se 0·08) (×10(7)) v. 1·3 (se 0·06) (×10(7)) arbitrary units; P = 0·005) in obese v. lean subjects. BCAA were positively associated with VAT (R 0·49; P = 0·0006) and trended to an association with SAT (R 0·29; P = 0·052). The association between BCAA and VAT, but not SAT, remained significant after controlling for age, sex and race on multivariate modelling (P < 0·05). BCAA were also associated with parameters of insulin sensitivity (Matsuda index: R -0·50, P = 0·0004; glucose AUC: R 0·53, P < 0·001). BCAA were not associated with B-AIBA (R -0·04; P = 0·79). B-AIBA was negatively associated with SAT (R -0·37; P = 0·01) but only trended to an association with VAT (R 0·27; P = 0·07). However, neither relationship remained significant after multivariate modelling (P > 0·05). Plasma B-AIBA was associated with parameters of insulin sensitivity (Matsuda index R 0·36, P = 0·01; glucose AUC: R -0·30, P = 0·04). Plasma BCAA levels were positively correlated with VAT and markers of insulin resistance. The results suggest a possible complex role of adipose tissue in BCAA homeostasis and insulin resistance.

  5. Linear Titration Curves of Acids and Bases.

    PubMed

    Joseph, N R

    1959-05-29

    The Henderson-Hasselbalch equation, by a simple transformation, becomes pH - pK = pA - pB, where pA and pB are the negative logarithms of acid and base concentrations. Sigmoid titration curves then reduce to straight lines; titration curves of polyelectrolytes, to families of straight lines. The method is applied to the titration of the dipeptide glycyl aminotricarballylic acid, with four titrable groups. Results are expressed as Cartesian and d'Ocagne nomograms. The latter is of a general form applicable to polyelectrolytes of any degree of complexity.

  6. Chronic administration of ursodeoxycholic and tauroursodeoxycholic acid changes microsomal membrane lipid content and fatty acid compositions in rats.

    PubMed

    Bellentani, S; Chao, Y C; Ferretti, I; Panini, R; Tiribelli, C

    1996-03-27

    We studied the effect of oral supplementation with ursodeoxycholate (UDCA) or tauroursodeoxycholate (TUDCA) on the lipid content and fatty acid composition of rat hepatic microsomes. UDCA and TUDCA significantly increased the total amount of lipids with the exception of cholesteryl-esters. UDCA significantly increased the triglycerides and phosphatidylethanolamine (PE) microsomal content, and decreased the cholesterol/phospholipids and the phosphatidylcholine (PC)/PE ratio. Both treatments increased the percentage oleic acid and of polyunsaturated fatty acids (PUFA) in each class of lipids. UDCA and TUDCA had a different action on PUFA microsomal molar percentage of phospholipids: UDCA increased the relative percentage of PUFA in the PE fraction, while TUDCA increased the relative percentage of PUFA in the PC fraction. These changes in the hepatic lipid content and composition might in part explain both cytoprotective action of these hydrophillic bile acids and their effect on membrane fluidity.

  7. Fatty Acid Composition of Different Collections of Coprinoid Mushrooms (Agaricomycetes) and Their Nutritional and Medicinal Values.

    PubMed

    Badalyan, Susanna M

    2016-01-01

    Qualitative and quantitative analyses of the free fatty acid (FA) composition of ethanol extracts obtained from mycelia of 30 genetically identified strains of 18 species of coprinoid mushrooms (CMs) or coprini belonging to clades Coprinellus (C. bisporus, C. curtus, C. disseminatus, C. domesticus, C. ellisii, C.flocculosus, C. micaceus, C. aff radians I, C. aff radians II, C. aff radians III, C. xanthothrix, Coprinellus sp. 4), Coprinopsis (C. cinerea, C. cothurnata, C. gonophylla, C. lagopides, C. maysoidispora, C. strossmayeri), and Coprinus (C. comatus) were evaluated using gas chromatography. Two unsaturated (lineolic, oleic) and 3 saturated (palmitic, stearic, myristic) FAs were detected in the tested mycelial samples. Amounts of unsaturated FAs prevailed over saturated FAs. Lineolic and palmitic acids were detected in all the species in high quantities (up to 64.73% and 53.82%, respectively). All 5 FAs were found in the Coprinus clade (family Agaricaceae) as opposed to the Coprinellus and Coprinopsis clades (family Psathyrellaceae). Based on the unsaturated and saturated FA content, the species from the clade Coprinellus were different from Coprinopsis species and C. comatus. The obtained data confirm that palmitic, linoleic, and stearic acids are predominant in mushrooms, including coprini. The presence of large amounts of unsaturated FAs in the tested coprini make them an option for further studies to formulate novel mushroom-based dietary supplements and nutriceuticals.

  8. Fatty acid compositions of triglycerides and free fatty acids in sebum depend on amount of triglycerides, and do not differ in presence or absence of acne vulgaris.

    PubMed

    Akaza, Narifumi; Akamatsu, Hirohiko; Numata, Shigeki; Matsusue, Miyuki; Mashima, Yasuo; Miyawaki, Masaaki; Yamada, Shunji; Yagami, Akiko; Nakata, Satoru; Matsunaga, Kayoko

    2014-12-01

    To clarify the influence of the fatty acid composition of sebum in acne vulgaris, we investigated the amounts and fatty acid compositions of triglycerides (TG) and free fatty acids (FFA), and the amounts of cutaneous superficial Propionibacterium acnes in acne patients and healthy subjects. The foreheads of 18 female patients, 10 male patients, 10 healthy females and 10 healthy males were studied in a Japanese population. There were significant differences in the amounts of sebum, TG and cutaneous superficial P. acnes, as well as the fatty acid compositions of TG and FFA between acne patients and healthy subjects in females. Their fatty acid compositions were correlated with the amount of TG with or without acne. It was clarified that the fatty acid compositions of TG and FFA depended on the amount of TG, and there were no differences in the fatty acid composition in the presence and absence of acne.

  9. Changes in fatty acid and hydrocarbon composition of zooplankton assemblages related to environmental conditions

    SciTech Connect

    Lambert, R.M.

    1989-01-01

    Changes in zooplankton fatty acid and hydrocarbon patterns are described in relation to changes in environmental conditions and species composition. The regulation of zooplankton abundance by sea nettle-ctenophore interaction was examined in a small Rhode Island coastal pond. Sea nettles were nettles were able to eliminate ctenophores from the pond and subsequently zooplankton abundance increased. During one increase in zooplankton abundance, it was found that polyunsaturated fatty acids decreased while monounsaturated fatty acids increased. It was concluded that this shift in biochemical pattern was due to food limitation. In addition, zooplankton fatty acids were used in multivariate discriminant analysis to classify whether zooplankton were from coastal or estuarine environments. Zooplankton from coastal environments were characterized by higher monounsaturate fatty acids. Zooplankton hydrocarbon composition was affected by species composition and by pollution inputs. The presence of Calanus finmarchicus was detected by increased levels of pristane.

  10. [FATTY ACID COMPOSITION ALTEROMONAS-LIKE BACTERIA ISOLATED FROM THE BLACK SEA WATER].

    PubMed

    Klochko, V V; Avdeeva, L V

    2015-01-01

    Alteromonas macleodii strains isolated from the Black sea water were similar in their fatty acids composition with the type strain of this species. Analysis of lipid composition of 10 A. macleodii strains isolated from the deep and surface water layers in different World ocean regions including the Black sea water has shown that the deep and surface isolates of this species formed two groups different in their fatty acids profiles. The Black sea isolates of Pseudoalteromonas haloplanktis, P. citrea, P. flavipulchra conformed to these species type strains in their fatty acids composition. On the basis of the fatty acids spectra similarity of three Pseudoalteromonas species strains with Plipolytica described in 2010 has been established. Presence of three isomers C16:1ψ7, C 16:1ψ9 and C16:1ψ6--components of hexadecenic acid in the Black sea isolates of Shewanella baltica has been shown.

  11. Bioinspired twisted composites based on Bouligand structures

    NASA Astrophysics Data System (ADS)

    Pinto, F.; Iervolino, O.; Scarselli, G.; Ginzburg, D.; Meo, M.

    2016-04-01

    The coupling between structural support and protection makes biological systems an important source of inspiration for the development of advanced smart composite structures. In particular, some particular material configurations can be implemented into traditional composites in order to improve their impact resistance and the out-of-plane properties, which represents one of the major weakness of commercial carbon fibres reinforced polymers (CFRP) structures. Based on this premise, a three-dimensional twisted arrangement shown in a vast multitude of biological systems (such as the armoured cuticles of Scarabei, the scales of Arapaima Gigas and the smashing club of Odontodactylus Scyllarus) has been replicated to develop an improved structural material characterised by a high level of in-plane isotropy and a higher interfacial strength generated by the smooth stiffness transition between each layer of fibrils. Indeed, due to their intrinsic layered nature, interlaminar stresses are one of the major causes of failure of traditional CFRP and are generated by the mismatch of the elastic properties between plies in a traditional laminate. Since the energy required to open a crack or a delamination between two adjacent plies is due to the difference between their orientations, the gradual angle variation obtained by mimicking the Bouligand Structures could improve energy absorption and the residual properties of carbon laminates when they are subjected to low velocity impact event. Two different bioinspired laminates were manufactured following a double helicoidal approach and a rotational one and were subjected to a complete test campaign including low velocity impact loading and compared to a traditional quasi-isotropic panel. Fractography analysis via X-Ray tomography was used to understand the mechanical behaviour of the different laminates and the residual properties were evaluated via Compression After Impact (CAI) tests. Results confirmed that the biological

  12. Spectrally based mapping of riverbed composition

    USGS Publications Warehouse

    Legleiter, Carl; Stegman, Tobin K.; Overstreet, Brandon T.

    2016-01-01

    Remote sensing methods provide an efficient means of characterizing fluvial systems. This study evaluated the potential to map riverbed composition based on in situ and/or remote measurements of reflectance. Field spectra and substrate photos from the Snake River, Wyoming, USA, were used to identify different sediment facies and degrees of algal development and to quantify their optical characteristics. We hypothesized that accounting for the effects of depth and water column attenuation to isolate the reflectance of the streambed would enhance distinctions among bottom types and facilitate substrate classification. A bottom reflectance retrieval algorithm adapted from coastal research yielded realistic spectra for the 450 to 700 nm range; but bottom reflectance-based substrate classifications, generated using a random forest technique, were no more accurate than classifications derived from above-water field spectra. Additional hypothesis testing indicated that a combination of reflectance magnitude (brightness) and indices of spectral shape provided the most accurate riverbed classifications. Convolving field spectra to the response functions of a multispectral satellite and a hyperspectral imaging system did not reduce classification accuracies, implying that high spectral resolution was not essential. Supervised classifications of algal density produced from hyperspectral data and an inferred bottom reflectance image were not highly accurate, but unsupervised classification of the bottom reflectance image revealed distinct spectrally based clusters, suggesting that such an image could provide additional river information. We attribute the failure of bottom reflectance retrieval to yield more reliable substrate maps to a latent correlation between depth and bottom type. Accounting for the effects of depth might have eliminated a key distinction among substrates and thus reduced discriminatory power. Although further, more systematic study across a broader

  13. Spectrally based mapping of riverbed composition

    NASA Astrophysics Data System (ADS)

    Legleiter, Carl J.; Stegman, Tobin K.; Overstreet, Brandon T.

    2016-07-01

    Remote sensing methods provide an efficient means of characterizing fluvial systems. This study evaluated the potential to map riverbed composition based on in situ and/or remote measurements of reflectance. Field spectra and substrate photos from the Snake River, Wyoming, USA, were used to identify different sediment facies and degrees of algal development and to quantify their optical characteristics. We hypothesized that accounting for the effects of depth and water column attenuation to isolate the reflectance of the streambed would enhance distinctions among bottom types and facilitate substrate classification. A bottom reflectance retrieval algorithm adapted from coastal research yielded realistic spectra for the 450 to 700 nm range; but bottom reflectance-based substrate classifications, generated using a random forest technique, were no more accurate than classifications derived from above-water field spectra. Additional hypothesis testing indicated that a combination of reflectance magnitude (brightness) and indices of spectral shape provided the most accurate riverbed classifications. Convolving field spectra to the response functions of a multispectral satellite and a hyperspectral imaging system did not reduce classification accuracies, implying that high spectral resolution was not essential. Supervised classifications of algal density produced from hyperspectral data and an inferred bottom reflectance image were not highly accurate, but unsupervised classification of the bottom reflectance image revealed distinct spectrally based clusters, suggesting that such an image could provide additional river information. We attribute the failure of bottom reflectance retrieval to yield more reliable substrate maps to a latent correlation between depth and bottom type. Accounting for the effects of depth might have eliminated a key distinction among substrates and thus reduced discriminatory power. Although further, more systematic study across a broader range

  14. Fatty acid composition of brown adipose tissue in genetically heat-tolerant FOK rats

    NASA Astrophysics Data System (ADS)

    Ohno, T.; Furuyama, F.; Kuroshima, A.

    The phospholipid fatty acid composition of brown adipose tissue (BAT) was examined in inbred heat-tolerant FOK rats and compared with that in conventional Wistar rats not previously exposed to heat. The FOK rats showed higher unsaturation states, as indicated by higher levels of polyunsaturated fatty acids and a higher unsaturation index and polyunsaturated fatty acids/saturated fatty acids ratio. This higher level of unsaturation was characterized by the higher amount of polyunsaturated fatty acids such as linoleic acid, arachidonic acid and docosahexaenoic acid. It may be concluded that the increased docosahexaenoic acid level in BAT phospholipids brings about the hyperplasia of BAT, causing an enhancement of its in vivo thermogernic activity as well as the systemic non-shivering thermogenesis observed in heat-tolerant FOK rats.

  15. Lipidomic Profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii Reveals Critical Changes in Lipid Composition in Response to Acetic Acid Stress

    PubMed Central

    Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

    2013-01-01

    When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L−1, while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L−1 acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large

  16. Lipidomic profiling of Saccharomyces cerevisiae and Zygosaccharomyces bailii reveals critical changes in lipid composition in response to acetic acid stress.

    PubMed

    Lindberg, Lina; Santos, Aline Xs; Riezman, Howard; Olsson, Lisbeth; Bettiga, Maurizio

    2013-01-01

    When using microorganisms as cell factories in the production of bio-based fuels or chemicals from lignocellulosic hydrolysate, inhibitory concentrations of acetic acid, released from the biomass, reduce the production rate. The undissociated form of acetic acid enters the cell by passive diffusion across the lipid bilayer, mediating toxic effects inside the cell. In order to elucidate a possible link between lipid composition and acetic acid stress, the present study presents detailed lipidomic profiling of the major lipid species found in the plasma membrane, including glycerophospholipids, sphingolipids and sterols, in Saccharomyces cerevisiae (CEN.PK 113_7D) and Zygosaccharomyces bailii (CBS7555) cultured with acetic acid. Detailed physiological characterization of the response of the two yeasts to acetic acid has also been performed in aerobic batch cultivations using bioreactors. Physiological characterization revealed, as expected, that Z. bailii is more tolerant to acetic acid than S. cerevisiae. Z. bailii grew at acetic acid concentrations above 24 g L(-1), while limited growth of S. cerevisiae was observed after 11 h when cultured with only 12 g L(-1) acetic acid. Detailed lipidomic profiling using electrospray ionization, multiple-reaction-monitoring mass spectrometry (ESI-MRM-MS) showed remarkable changes in the glycerophospholipid composition of Z. bailii, including an increase in saturated glycerophospholipids and considerable increases in complex sphingolipids in both S. cerevisiae (IPC 6.2×, MIPC 9.1×, M(IP)2C 2.2×) and Z. bailii (IPC 4.9×, MIPC 2.7×, M(IP)2C 2.7×), when cultured with acetic acid. In addition, the basal level of complex sphingolipids was significantly higher in Z. bailii than in S. cerevisiae, further emphasizing the proposed link between lipid saturation, high sphingolipid levels and acetic acid tolerance. The results also suggest that acetic acid tolerance is associated with the ability of a given strain to generate large

  17. Maximized PUFA measurements improve insight in changes in fatty acid composition in response to temperature.

    PubMed

    van Dooremalen, Coby; Pel, Roel; Ellers, Jacintha

    2009-10-01

    A general mechanism underlying the response of ectotherms to environmental changes often involves changes in fatty acid composition. Theory predicts that a decrease in temperature causes an increase in unsaturation of fatty acids, with an important role for long-chain poly-unsaturated fatty acids (PUFAs). However, PUFAs are particularly unstable and susceptible to peroxidation, hence subtle differences in fatty acid composition can be challenging to detect. We determined the fatty acid composition in springtail (Collembola) in response to two temperatures (5 degrees C and 25 degrees C). First, we tested different sample preparation methods to maximize PUFAs. Treatments consisted of different solvents for primary lipid extraction, mixing with antioxidant, flushing with inert gas, and using different temperature exposures during saponification. Especially slow saponification at low temperature (90 min at 70 degrees C) in combination with replacement of headspace air with nitrogen during saponification and methylation maximized PUFAs for GC analysis. Applying these methods to measure thermal responses in fatty acid composition, the data showed that the (maximized) proportion of C(20) PUFAs increased at low acclimation temperature. However, C(18) PUFAs increased at high acclimation temperature, which is contrary to expectations. Our study illustrates that PUFA levels in lipids may often be underestimated and this may hamper a correct interpretation of differential responses of fatty acid composition.

  18. Effect of γ irradiation on the fatty acid composition of soybean and soybean oil.

    PubMed

    Minami, Ikuko; Nakamura, Yoshimasa; Todoriki, Setsuko; Murata, Yoshiyuki

    2012-01-01

    Food irradiation is a form of food processing to extend the shelf life and reduce spoilage of food. We examined the effects of γ radiation on the fatty acid composition, lipid peroxidation level, and antioxidative activity of soybean and soybean oil which both contain a large amount of unsaturated fatty acids. Irradiation at 10 to 80 kGy under aerobic conditions did not markedly change the fatty acid composition of soybean. While 10-kGy irradiation did not markedly affect the fatty acid composition of soybean oil under either aerobic or anaerobic conditions, 40-kGy irradiation considerably altered the fatty acid composition of soybean oil under aerobic conditions, but not under anaerobic conditions. Moreover, 40-kGy irradiation produced a significant amount of trans fatty acids under aerobic conditions, but not under anaerobic conditions. Irradiating soybean oil induced lipid peroxidation and reduced the radical scavenging activity under aerobic conditions, but had no effect under anaerobic conditions. These results indicate that the fatty acid composition of soybean was not markedly affected by radiation at 10 kGy, and that anaerobic conditions reduced the degradation of soybean oil that occurred with high doses of γ radiation.

  19. Sugar beet pulp and poly(lactic acid) composites using methylene diphenyl diisocyanate as coupling agent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Composites from sugar beet pulp (SBP) and poly(lactic acid) (PLA) were extruded in the presence of polymeric methylene diphenyl diisocyanate (pMDI). SBP particles were evenly distributed within the PLA matrix phase as revealed by confocal fluorescence microscopic analysis. The resultant composites w...

  20. Starch/fiber/poly(lactic acid) foam and compressed foam composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Composites of starch, fiber, and poly(lactic acid) (PLA) were made using a foam substrate formed by dehydrating starch or starch/fiber gels. PLA was infiltrated into the dry foam to provide better moisture resistance. Foam composites were compressed into plastics using force ranging from 4-76MPa. Te...

  1. Poly(lactic acid) and Osage Orange Wood Fiber Composites for Agricultural Mulch Films

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Osage orange wood was combined with poly(lactic acid) to form a polymer composite intendedfor use as an agricultural mulch film. The mechanical properties were comparable to existing products and had the advantage of being completely biodegradable through a single growing season. PLA-OO composites...

  2. Graphene-carbon nanotube composite aerogel for selective detection of uric acid

    NASA Astrophysics Data System (ADS)

    Zhang, Feifei; Tang, Jie; Wang, Zonghua; Qin, Lu-Chang

    2013-12-01

    Graphene and single-walled carbon nanotube (SWNT) composite aerogel has been prepared by hydrothermal synthesis. The restacking of graphene is effectively reduced by SWNTs inserted in between graphene layers in order to make available more active sites and reactive surface area. Electrochemical experiments show that the graphene-SWNT composite electrode has superior catalytic performance in selective detection of uric acid (UA).

  3. Effect of oil type and fatty acid composition on dynamic and steady shear rheology of vegetable oils.

    PubMed

    Yalcin, Hasan; Toker, Omer Said; Dogan, Mahmut

    2012-01-01

    In this study, effect of fatty acid composition on dynamic and steady shear rheology of oils was studied. For this aim, different types of vegetable oils (soybean, sunflower, olive, hazelnut, cottonseed and canola), were used. Rheological properties of oil samples were identified by rheometer (Thermo-Haake) at 25°C and fatty acid composition of oils was determined by GC (Agilent 6890). Steady shear rheological properties of oil samples were measured at shear rate range of 0.1-100 s⁻¹. Viscosity of olive, hazelnut, cottonseed, canola, soybean and sunflower was 61.2 mPa.s, 59.7 mPa.s, 57.3 mPa.s, 53.5 mPa.s, 48.7 mPa.s and 48.2 mPa.s, respectively. There was a significant difference between viscosity of oils except soybean and sunflower. As a result it was seen that there was a correlation between viscosity and monounsaturated (R=0.89), polyunsaturated (R=-0.97) fatty acid composition of oils, separately. Equation was found to predict viscosity of the oils based on mono and polyunsaturation composition of oils. In addition the dynamic rheological properties of oils were also examined. G', G'' and tan δ (G''/G') values were measured at 0.3 Pa (in viscoelastic region) and 0.1-1 Hz. As a result of multiple regression analysis another equations were found between tan δ, viscosity and polyunsaturated fatty acids.

  4. The Amino Acid Composition of the Sutter's Mill Carbonaceous Chondrite

    NASA Technical Reports Server (NTRS)

    Glavin, D. P.; Burton, A. S.; Elsila, J. E.; Dworkin, J. P.; Yin, Q. Z.; Cooper, G.; Jenniskens, P.

    2012-01-01

    In contrast to the Murchison meteorite which had a complex distribution of amino acids with a total C2 to Cs amino acid abundance of approx.14,000 parts-per-billion (ppb) [2], the Sutters Mill meteorite was found to be highly depleted in amino acids. Much lower abundances (approx.30 to 180 ppb) of glycine, beta-alanine, L-alanine and L-serine were detected in SM2 above procedural blank levels indicating that this meteorite sample experienced only minimal terrestrial amino acid contamination after its fall to Earth. Carbon isotope measurements will be necessary to establish the origin of glycine and beta-alanine in SM2. Other non-protein amino acids that are rare on Earth, yet commonly found in other CM meteorites such as aaminoisobutyric acid (alpha-AIB) and isovaline, were not identified in SM2. However, traces of beta-AIB (approx.1 ppb) were detected in SM2 and could be" extraterrestrial in origin. The low abundances of amino acids in the Sutter's Mill meteorite is consistent with mineralogical evidence that at least some parts of the Sutter's Mill meteorite parent body experienced extensive aqueous and/or thermal alteration.

  5. Milk fat globules: fatty acid composition, size and in vivo regulation of fat liquidity.

    PubMed

    Timmen, H; Patton, S

    1988-07-01

    Populations of large and small milk fat globules were isolated and analyzed to determine differences in fatty acid composition. Globule samples were obtained by centrifugation from milks of a herd and of individual animals produced under both pasture and barn feeding. Triacylglycerols of total globule lipids were prepared by thin layer chromatography and analyzed for fatty acid composition by gas chromatography. Using content of the acids in large globules as 100%, small globules contained fewer short-chain acids, -5.9%, less stearic acid, -22.7%, and more oleic acids, +4.6%, mean values for five trials. These differences are consistent with alternative use of short-chain acids or oleic acid converted from stearic acid to maintain liquidity at body temperature of milk fat globules and their precursors, intracellular lipid droplets. Stearyl-CoA desaturase (EC 1.14.99.5), which maintains fluidity of cellular endoplasmic reticulum membrane, is suggested to play a key role in regulating globule fat liquidity. Possible origins of differences between individual globules in fatty acid composition of their triacylglycerols are discussed.

  6. The first proton sponge-based amino acids: synthesis, acid-base properties and some reactivity.

    PubMed

    Ozeryanskii, Valery A; Gorbacheva, Anastasia Yu; Pozharskii, Alexander F; Vlasenko, Marina P; Tereznikov, Alexander Yu; Chernov'yants, Margarita S

    2015-08-21

    The first hybrid base constructed from 1,8-bis(dimethylamino)naphthalene (proton sponge or DMAN) and glycine, N-methyl-N-(8-dimethylamino-1-naphthyl)aminoacetic acid, was synthesised in high yield and its hydrobromide was structurally characterised and used to determine the acid-base properties via potentiometric titration. It was found that the basic strength of the DMAN-glycine base (pKa = 11.57, H2O) is on the level of amidine amino acids like arginine and creatine and its structure, zwitterionic vs. neutral, based on the spectroscopic (IR, NMR, mass) and theoretical (DFT) approaches has a strong preference to the zwitterionic form. Unlike glycine, the DMAN-glycine zwitterion is N-chiral and is hydrolytically cleaved with the loss of glycolic acid on heating in DMSO. This reaction together with the mild decarboxylative conversion of proton sponge-based amino acids into 2,3-dihydroperimidinium salts under air-oxygen was monitored with the help of the DMAN-alanine amino acid. The newly devised amino acids are unique as they combine fluorescence, strongly basic and redox-active properties.

  7. Draft Genome Sequence of Cyanobacterium sp. Strain IPPAS B-1200 with a Unique Fatty Acid Composition

    PubMed Central

    Starikov, Alexander Y.; Usserbaeva, Aizhan A.; Sinetova, Maria A.; Sarsekeyeva, Fariza K.; Zayadan, Bolatkhan K.; Ustinova, Vera V.; Kupriyanova, Elena V.; Los, Dmitry A.

    2016-01-01

    Here, we report the draft genome of Cyanobacterium sp. IPPAS strain B-1200, isolated from Lake Balkhash, Kazakhstan, and characterized by the unique fatty acid composition of its membrane lipids, which are enriched with myristic and myristoleic acids. The approximate genome size is 3.4 Mb, and the predicted number of coding sequences is 3,119. PMID:27856596

  8. Polyurea-Based Aerogel Monoliths and Composites

    NASA Technical Reports Server (NTRS)

    Lee, Je Kyun

    2012-01-01

    aerogel insulation material was developed that will provide superior thermal insulation and inherent radiation protection for government and commercial applications. The rubbery polyureabased aerogel exhibits little dustiness, good flexibility and toughness, and durability typical of the parent polyurea polymer, yet with the low density and superior insulation properties associated with aerogels. The thermal conductivity values of polyurea-based aerogels at lower temperature under vacuum pressures are very low and better than that of silica aerogels. Flexible, rubbery polyurea-based aerogels are able to overcome the weak and brittle nature of conventional inorganic and organic aerogels, including polyisocyanurate aerogels, which are generally prepared with the one similar component to polyurethane rubber aerogels. Additionally, with higher content of hydrogen in their structures, the polyurea rubber-based aerogels will also provide inherently better radiation protection than those of inorganic and carbon aerogels. The aerogel materials also demonstrate good hydrophobicity due to their hydrocarbon molecular structure. There are several strategies to overcoming the drawbacks associated with the weakness and brittleness of silica aerogels. Development of the flexible fiber-reinforced silica aerogel composite blanket has proven to be one promising approach, providing a conveniently fielded form factor that is relatively robust in industrial environments compared to silica aerogel monoliths. However, the flexible, silica aerogel composites still have a brittle, dusty character that may be undesirable, or even intolerable, in certain application environments. Although the cross - linked organic aerogels, such as resorcinol- formaldehyde (RF), polyisocyanurate, and cellulose aerogels, show very high impact strength, they are also very brittle with little elongation (i.e., less rubbery). Also, silica and carbon aerogels are less efficient radiation shielding materials due

  9. Sensitive Amino Acid Composition and Chirality Analysis with the Mars Organic Analyzer (MOA)

    NASA Technical Reports Server (NTRS)

    Skelley, Alison M.; Scherer, James R.; Aubrey, Andrew D.; Grover, William H.; Ivester, Robin H. C.; Ehrenfreund, Pascale; Grunthaner, Frank J.; Bada, Jeffrey L.; Mathies, Richard A.

    2005-01-01

    Detection of life on Mars requires definition of a suitable biomarker and development of sensitive yet compact instrumentation capable of performing in situ analyses. Our studies are focused on amino acid analysis because amino acids are more resistant to decomposition than other biomolecules, and because amino acid chirality is a well-defined biomarker. Amino acid composition and chirality analysis has been previously demonstrated in the lab using microfabricated capillary electrophoresis (CE) chips. To analyze amino acids in the field, we have developed the Mars Organic Analyzer (MOA), a portable analysis system that consists of a compact instrument and a novel multi-layer CE microchip.

  10. Isoleucine epimerization and amino acid composition in molecular-weight separations of Pleistocene Genyornis eggshell

    NASA Astrophysics Data System (ADS)

    Kaufman, Darrell S.; Miller, Gifford H.

    1995-07-01

    This study explores the geochronological utility and analytical reproducibility of separating the high-molecular-weight fraction (HMW) from eggshells of the extinct late Pleistocene ratite, Genyornis, using disposable, prepacked gel-filtration columns. The superior integrity of ratite eggshell for the retention of amino acids indicates that this biomineral is better suited for this type of investigation than previously studied molluscan shell. To evaluate the reproducibility of the gel-filtration technique, we analyzed triplicate subsamples of three eggshells of different ages. The reproducibility, based on the average intrashell variation (coefficient of variation; CV) in the extent of isoleucine epimerization (aIle/Ile) in the HMW (enriched in molecules ca. >10,000 MW) is 3%, well within the range appropriate for geochronological purposes. The average intrashell variation in the total amino acid concentration (Σ[aa]) of the HMW is 5%, somewhat better than for the total acid hydrolysate (TOTAL) of the same samples (7%). To evaluate the relation between molecular weight and the rate of isoleucine epimerization, three molecular-weight fractions were separated using gel filtration, plus the naturally hydrolyzed free fraction (FREE), for each of four fossil eggshells. AIle/Ile increases with decreasing molecular weight in all shells, with a ca. sixfold to ninefold difference in ratios between the HMW andFREE, and a ca. fivefold difference between the HMW andTOTAL. Although linear correlations between aIle/Ile measured in each molecular-weight fraction and in theTOTAL are all highly significant (r ⩾ 0.951), the relation between the extent of epimerization in the HMW and in the TOTAL is best expressed as an exponential function (r = 0.951). This relation is consistent with the idea that, as the epimerization reaction approaches equilibrium in theTOTAL (ca. aIle/Ile > 1.1), its rate decreases beyond that of the HMW. The amino acid composition (relative percent of

  11. Analysis of fatty acid composition of sea cucumber Apostichopus japonicus using multivariate statistics

    NASA Astrophysics Data System (ADS)

    Xu, Qinzeng; Gao, Fei; Xu, Qiang; Yang, Hongsheng

    2014-11-01

    Fatty acids (FAs) provide energy and also can be used to trace trophic relationships among organisms. Sea cucumber Apostichopus japonicus goes into a state of aestivation during warm summer months. We examined fatty acid profiles in aestivated and non-aestivated A. japonicus using multivariate analyses (PERMANOVA, MDS, ANOSIM, and SIMPER). The results indicate that the fatty acid profiles of aestivated and non-aestivated sea cucumbers differed significantly. The FAs that were produced by bacteria and brown kelp contributed the most to the differences in the fatty acid composition of aestivated and nonaestivated sea cucumbers. Aestivated sea cucumbers may synthesize FAs from heterotrophic bacteria during early aestivation, and long chain FAs such as eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) that produced from intestinal degradation, are digested during deep aestivation. Specific changes in the fatty acid composition of A. japonicus during aestivation needs more detailed study in the future.

  12. [Amino acid composition and biologic value of the proteins of several sorts of buckwheat].

    PubMed

    Sarkisova, N E; Kirilenko, S K

    1976-01-01

    The amino acids composition of summary proteins in unground buckwheat of four common and promising varieties grown in the Ukraine was investigated by using ion-exchange chromatography with an automatic analyzor Hd-1200 E. Between individual varieties of buckweheat no essential differences in the amino acids content were in evidence. The total proteins of the buckwheat grit contain high quantities of lysine, treonine, leucine, glutamic acid and arginine. The amino acids score was instrumental in determining the biological value and in eliciting amino acids limiting this value in different grits. These data may be made use of in the practice of public catering for estimating formulae of meals prepared with grits differently combined with other products securing an improved amino acids composition of ready-to-eat meals.

  13. Essential and long-chain polyunsaturated fatty acid status and fatty acid composition of breast milk of lactating adolescents.

    PubMed

    Meneses, Flávia; Torres, Alexandre G; Trugo, Nádia M F

    2008-11-01

    The aims of the present study were to evaluate essential fatty acids (EFA) and long-chain PUFA (LCPUFA) status in lactating adolescents and its association with breast milk composition. Healthy nursing adolescents from Rio de Janeiro, Brazil (n 30; 14-19 years; 30-120 d postpartum), exclusively or predominantly breast-feeding, participated in this study. Breast milk and blood samples were collected after overnight fasting. Fatty acid composition of breast milk, erythrocyte membrane (EM) and plasma NEFA were determined by GC. Indices of fatty acid status (mean melting point (MMP); EFA status index; DHA status indices, 22 : 5n-6:22 : 4n-6 and 22 : 6n-3:22 : 5n-6 ratios) were calculated from EM fatty acid composition. Dietary intake of n-3 fatty acids was low when compared with current recommendations for lactating women. MMP was associated with indices of DHA status, some individual fatty acids in EM and years post-menarche and weeks postpartum, suggesting the use of erythrocyte MMP as a possible comprehensive biochemical marker of LCPUFA status in this physiological condition. The DHA status of lactating adolescents and their milk DHA concentrations were similar to the values of Brazilian lactating adults, but lower compared with the values of lactating adults from other countries. Therefore, these lactating adolescents were apparently not disadvantaged, as compared with the Brazilian adults, when EM and breast milk fatty acid composition were considered. In general, PUFA in milk from adolescents presented few associations with their concentrations in plasma NEFA and with maternal status. However, milk DHA was associated with maternal LCPUFA and DHA states.

  14. Dynamic gold nanoparticle, polymer-based composites

    NASA Astrophysics Data System (ADS)

    Firestone, Millicent; Junghans, Ann; Hayden, Steven; Majeski, Jaroslaw; CINT, Lujan Team

    2014-03-01

    Artificial polymer-based biomembranes may serve as a foundational architecture for the integration and spatial organization of metal nanoparticles forming functional nanocomposites. Nonionic triblock copolymer (PEO-PPO-PEO), lipid-based gels, containing Au nanoparticles (NPs) can be prepared by either external doping of the preformed nanoparticles or by in-situ reduction of Au 3+. Neutron reflectivity on quartz supported thin films of the Au NP -doped polymer-based biomembranes was used to determine the location of the Au. The nanoparticles were found to preferentially reside within the ethylene oxide chains located at the interface of the bulk water channels and the amphiphile bilayers. The embedded Au nanoparticles can act as localized heat sinks, inducing changes in the polymer conformation. The collective, thermally-triggered expansion and contraction of the EO chains modulate the mesophase structure of the gels. Synchrotron X-ray scattering (SAXS) was used to monitor mesophase structure as a function of both temperature and photo-irradiation. These studies represent a first step towards designingexternally-responsive polymer-nanoparticle composites.

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

    PubMed

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

    2015-01-30

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

  16. Compositions containing amino acids, phosphate and manganese and their uses

    DOEpatents

    Daly, Michael J.; Gaidamakova, Elena K.

    2016-01-12

    The invention provides methods of producing vaccines directed against microorganisms, with the methods comprising culturing, harvesting and/or suspending the microorganism in the presence of a radiation-protective composition and irradiating the bacteria or viruses with a dose of radiation sufficient to render the microorganism replication-deficient and/or non-infective. The radiation-protective compositions used in the methods of the present invention comprise at least one nucleoside, at least one antioxidant and at least one small peptide. The invention also provides methods of rendering bacteria in culture resistant to ionizing radiation (IR), with these methods comprising culturing the bacteria in the presence of a radiation-protective composition.

  17. Fatty acid composition and extreme temperature tolerance following exposure to fluctuating temperatures in a soil arthropod.

    PubMed

    van Dooremalen, Coby; Suring, Wouter; Ellers, Jacintha

    2011-09-01

    Ectotherms commonly adjust their lipid composition to ambient temperature to counteract detrimental thermal effects on lipid fluidity. However, the extent of lipid remodeling and the associated fitness consequences under continuous temperature fluctuations are not well-described. The objective of this study was to investigate the effect of repeated temperature fluctuations on fatty acid composition and thermal tolerance. We exposed the springtail Orchesella cincta to two constant temperatures of 5 and 20°C, and a continuously fluctuating treatment between 5 and 20°C every 2 days. Fatty acid composition differed significantly between constant low and high temperatures. As expected, animals were most cold tolerant in the low temperature treatment, while heat tolerance was highest under high temperature. Under fluctuating temperatures, fatty acid composition changed with temperature initially, but later in the experiment fatty acid composition stabilized and closely resembled that found under constant warm temperatures. Consistent with this, heat tolerance in the fluctuating temperature treatment was comparable to the constant warm treatment. Cold tolerance in the fluctuating temperature treatment was intermediate compared to animals acclimated to constant cold or warmth, despite the fact that fatty acid composition was adjusted to warm conditions. This unexpected finding suggests that in animals acclimated to fluctuating temperatures an additional underlying mechanism is involved in the cold shock response. Other aspects of homeoviscous adaptation may protect animals during extreme cold. This paper forms a next step to fully understand the functioning of ectotherms in more thermally variable environments.

  18. Composition of antioxidants and amino acids in Stevia leaf infusions.

    PubMed

    Periche, Angela; Koutsidis, Georgios; Escriche, Isabel

    2014-03-01

    Stevia, a non-caloric natural sweetener with beneficial properties and considerable antioxidants and amino acids, is increasingly consumed as an infusion. This work evaluates the influence of the conditions (temperature: 50, 70 or 90 °C and time: 1, 5, 20 or 40 min) applied to obtain Stevia infusions, on antioxidants (total phenols, flavonoids and antioxidant activity) and amino acids. The total concentration of the eleven amino acids found was 11.70 mg/g in dried leaves and from 6.84 to 9.11 mg/g per gram of Stevia in infusions. However, infusions showed higher levels of certain amino acids (alanine, asparagine, leucine and proline), and greater values of the three antioxidant parameters in comparison with dry leaves. Temperature had more influence (minimum values at 50 °C and maximum at 90 °C) than time in the case of antioxidants. At 90 °C there were no important increases in the extraction of antioxidant compounds after 5 min; each gram of Stevia had 117 mg trolox (total antioxidant activity), 90 mg gallic acid (total phenols) and 56 mg catechin equivalents (flavonoids). Varying the temperature and time conditions no notable differences were observed in the concentrations of the majority of amino acids. However, the infusion treatment at 90 °C for 5 min was the best, as it gave the highest yield of 8 of the 11 amino acids. Therefore, with respect to the compounds analyzed in this study, the best way to obtain Stevia leaf infusions is the same as the domestic process, almost boiling water for a short time.

  19. Fatty Acid Composition of Escherichia coli as a Possible Controlling Factor of the Minimal Growth Temperature

    PubMed Central

    Shaw, Maxwell K.; Ingraham, John L.

    1965-01-01

    Shaw, Maxwell K. (University of California, Davis), and John L. Ingraham. Fatty acid composition of Escherichia coli as a possible controlling factor of the minimal growth temperature. J. Bacteriol. 90:141–146. 1965.—If Escherichia coli ML30 is shifted from 37 to 10 C during exponential growth in glucose minimal medium, a 4.5-hr lag results. During this lag, the proportion of unsaturated fatty acids increases in the cellular lipids. However, the adjustment of the fatty acid composition does not appear to be prerequisite to growth at 10 C. If shifts are made to 10 C into minimal medium containing glucose after starvation for glucose at 37 C for 0.5 and 16 hr, the lag periods at 10 C are 4.5 and 6 hr, respectively. Withholding glucose during the lag periods does not affect the duration of the lag periods, but no change in fatty acid composition occurs if glucose is not present. Supplementing the medium with glucose after the lag period permits immediate growth at 10 C; however, the fatty acid composition is still typical of cells grown at 37 C. It is concluded that the fatty acid composition of cells does not determine the minimal temperature of growth. PMID:16562009

  20. Texture of butter from cows with different milk fatty acid compositions.

    PubMed

    Bobe, G; Hammond, E G; Freeman, A E; Lindberg, G L; Beitz, D C

    2003-10-01

    Milk fatty acid composition and textural properties of butter are known to be affected by the cows' diets. We examined the phenotypic variation in milk fatty acid composition among cows fed the same diet to see if the variation was sufficient to produce butter with different textural properties. Ten cows were selected that tested higher (n = 5) or lower (n = 5) in their proportion of milk unsaturated fatty acids. Milk samples were collected a week after testing, and butter was prepared from the individual samples. Milk and butter samples were again analyzed for fatty acid composition. Butter at 5 degrees C was evaluated by a sensory panel for spreadability and by a texture analyzer at both 5 and 23 degrees C for hardness and adhesiveness. Milk and butter samples from cows with a more unsaturated milk fatty acid composition had a lower atherogenic index, and the butter samples were more spreadable, softer, and less adhesive. Thus, phenotypic variation in milk fatty acid composition among cows fed the same diet is sufficient to produce butter with different textural properties.

  1. The oxygen isotope composition of nitrate generated by nitrification in acid forest floors

    NASA Astrophysics Data System (ADS)

    Mayer, Bernhard; Bollwerk, Sandra M.; Mansfeldt, Tim; Hütter, Birgit; Veizer, Jan

    2001-09-01

    The oxygen isotope composition of nitrate is used increasingly for identifying the origin of nitrate in terrestrial and aquatic ecosystems. This novel isotope tracer technique is based on the fact that nitrate in atmospheric deposition, in fertilizers, and nitrate generated by nitrification in soils appear to have distinct oxygen isotope ratios. While the typical ranges of δ 18O values of nitrate in atmospheric deposition and fertilizers are comparatively well known, few experimental data exist for the oxygen isotope composition of nitrate generated by nitrification in soils. The objective of this study was to determine δ 18O values of nitrate formed by microbial nitrification in acid forest floors. Evidence from laboratory incubation experiments and field studies suggests that during microbial nitrification in acid forest floor horizons, up to two of the three oxygen atoms in newly formed nitrate are derived from water, particularly if ammonium is abundant and nitrification rates are high. It was, however, also observed that in ammonium-limited systems with low nitrification rates, significantly less than two thirds of the oxygen in newly formed nitrate can be derived from water oxygen, presumably as a result of heterotrophic nitrification. It can be concluded from the presented data that the δ 18O values of nitrate formed by microbial nitrification in acid forest floors typically range between +2 and +14‰, assuming that soil water δ 18O values vary between -15 and -5‰. Hence, oxygen isotope ratios of nitrate formed by nitrification in forest floors are usually distinct from those of other nitrate sources such as atmospheric deposition and synthetic fertilizers and, therefore, constitute a valuable qualitative tracer for distinguishing among these sources of nitrate. A quantitative source apportionment appears, however, difficult because of the wide range of δ 18O values, particularly for atmospheric nitrate deposition and for nitrate from microbial

  2. Plasma and neutrophil fatty acid composition in advanced cancer patients and response to fish oil supplementation.

    PubMed

    Pratt, V C; Watanabe, S; Bruera, E; Mackey, J; Clandinin, M T; Baracos, V E; Field, C J

    2002-12-02

    Metabolic demand and altered supply of essential nutrients is poorly characterised in patients with advanced cancer. A possible imbalance or deficiency of essential fatty acids is suggested by reported beneficial effects of fish oil supplementation. To assess fatty acid status (composition of plasma and neutrophil phospholipids) in advanced cancer patients before and after 14 days of supplementation (12+/-1 g day(-1)) with fish (eicosapentaenoic acid, and docosahexaenoic acid) or placebo (olive) oil. Blood was drawn from cancer patients experiencing weight loss of >5% body weight (n=23). Fatty acid composition of plasma phospholipids and the major phospholipid classes of isolated neutrophils were determined using gas liquid chromatography. At baseline, patients with advanced cancer exhibited low levels (<30% of normal values) of plasma phospholipids and constituent fatty acids and elevated 20 : 4 n-6 content in neutrophil phospholipids. High n-6/n-3 fatty acid ratios in neutrophil and plasma phospholipids were inversely related to body mass index. Fish oil supplementation raised eicosapentaenoic acid and docosahexaenoic acid content in plasma but not neutrophil phospholipids. 20 : 4 n-6 content was reduced in neutrophil PI following supplementation with fish oil. Change in body weight during the supplementation period related directly to increases in eicosapentaenoic acid in plasma. Advanced cancer patients have alterations in lipid metabolism potentially due to nutritional status and/or chemotherapy. Potential obstacles in fatty acid utilisation must be addressed in future trials aiming to improve outcomes using nutritional intervention with fish oils.

  3. Amino acid composition of cadmium-binding protein induced in a marine diatom

    SciTech Connect

    Maita, Y.; Kawaguchi, S. )

    1989-09-01

    Organisms living in environments polluted with heavy metals develop tolerance against these contaminants. The tolerance has been attributed to the ability to synthesize metal binding substances. These recent findings imply metal binding complexes from animals and plants, although having very similar functional properties, may have entirely different amino acid compositions. Researchers reported that cadystin from fission yeast, Schizosaccharomyces pombe was composed of only glutamic acid, cysteine, and glycine. A year later, a heavy metal binding substance was isolated from Rauwolfia serpetina which contains only Glu, Cys, and Gly. Heavy metal binding complexes isolated from the water hyacinth and morning glory Datura innoxia also showed an amino acid composition similar to cadystin or phytochelatin. In this study, the cadmium binding protein induced in the marine diatom, Phaeodactylum tricornutum, was isolated and purified and its amino acid composition determined.

  4. Semantics-based composition of EMBOSS services

    PubMed Central

    2011-01-01

    Background More than in other domains the heterogeneous services world in bioinformatics demands for a methodology to classify and relate resources in a both human and machine accessible manner. The Semantic Web, which is meant to address exactly this challenge, is currently one of the most ambitious projects in computer science. Collective efforts within the community have already led to a basis of standards for semantic service descriptions and meta-information. In combination with process synthesis and planning methods, such knowledge about types and services can facilitate the automatic composition of workflows for particular research questions. Results In this study we apply the synthesis methodology that is available in the Bio-jETI workflow management framework for the semantics-based composition of EMBOSS services. EMBOSS (European Molecular Biology Open Software Suite) is a collection of 350 tools (March 2010) for various sequence analysis tasks, and thus a rich source of services and types that imply comprehensive domain models for planning and synthesis approaches. We use and compare two different setups of our EMBOSS synthesis domain: 1) a manually defined domain setup where an intuitive, high-level, semantically meaningful nomenclature is applied to describe the input/output behavior of the single EMBOSS tools and their classifications, and 2) a domain setup where this information has been automatically derived from the EMBOSS Ajax Command Definition (ACD) files and the EMBRACE Data and Methods ontology (EDAM). Our experiments demonstrate that these domain models in combination with our synthesis methodology greatly simplify working with the large, heterogeneous, and hence manually intractable EMBOSS collection. However, they also show that with the information that can be derived from the (current) ACD files and EDAM ontology alone, some essential connections between services can not be recognized. Conclusions Our results show that adequate domain

  5. Genotype, production system and sex effects on fatty acid composition of meat from goat kids.

    PubMed

    Özcan, Mustafa; Demirel, Gulcan; Yakan, Akın; Ekiz, Bülent; Tölü, Cemil; Savaş, Türker

    2015-02-01

    Two trials were performed to assess the meat fatty acid profile of goat kids from different genotypes, production systems and sex. In the first trial, genotype effect was determined in 24 suckling male kids from Turkish Saanen, Maltese and Gokceada breeds. In the second trial, male and female Gokceada Goat kids were used to compare the effect of extensive and semi-intensive production systems on fatty acid composition of meat. Significant genotype effect was observed in the percentages of myristic acid (C14:0), palmitic acid (C16:0), oleic acid (C18:1 n-9), linolenic acid (C18:3 n-3), arachidonic acid (C20:4 n-6) and docosahexaenoic acid (C22:6 n-3), despite no differences on the ratios of polyunsaturated fatty acids to saturated fatty acids (PUFA/SFA) and n-6/n-3 (P > 0.05). The effect of production system had also significant effects on fatty acids, but sex only influenced significantly stearic acid (C18:0), C18:1 n-9 and C18:3 n-3 fatty acids and total PUFA level and PUFA/SFA ratio. This study confirms that dairy breeds are prone to produce higher levels of unsaturated fatty acids in their muscle. Meanwhile, meat from Gokceada goat kids, which is one of the indigenous breeds in Turkey, had similar PUFA/SFA and n-6/n-3 ratios to Turkish Saanen and Maltase.

  6. Versatile Boron Carbide-Based Visual Obscurant Compositions for Smoke Munitions

    DTIC Science & Technology

    2015-04-17

    ToxProfiles/tp97.pdf (accessed March, 2015). (6) Eaton, J. C.; Lopinto, R. J.; Palmer, W. G. Health Effects of Hexachloroethane (HC) Smoke; accession number...movements. Such compositions are characterized by a hazard/performance trade-off. The most effective ones tend to be toxic or incendiary, while the... inhalation -related injuries and deaths.6 Other pyrotechnic smokes based on the sublimation of trans- cinnamic acid or terephthalic acid (CA, TA) are not

  7. Assessment of oil content and fatty acid composition variability in two economically important Hibiscus species.

    PubMed

    Wang, Ming Li; Morris, Brad; Tonnis, Brandon; Davis, Jerry; Pederson, Gary A

    2012-07-04

    The Hibiscus genus encompasses more than 300 species, but kenaf (Hibiscus cannabinus L.) and roselle (Hibiscus sabdariffa L.) are the two most economically important species within the genus. Seeds from these two Hibiscus species contain a relatively high amount of oil with two unusual fatty acids: dihydrosterculic and vernolic acids. The fatty acid composition in the oil can directly affect oil quality and its utilization. However, the variability in oil content and fatty acid composition for these two species is unclear. For these two species, 329 available accessions were acquired from the USDA germplasm collection. Their oil content and fatty acid composition were determined by nuclear magnetic resonance (NMR) and gas chromatography (GC), respectively. Using NMR and GC analyses, we found that Hibiscus seeds on average contained 18% oil and seed oil was composed of six major fatty acids (each >1%) and seven minor fatty acids (each <1%). Hibiscus cannabinus seeds contained significantly higher amounts of oil (18.14%), palmitic (20.75%), oleic (28.91%), vernolic acids (VA, 4.16%), and significantly lower amounts of stearic (3.96%), linoleic (39.49%), and dihydrosterculic acids (DHSA, 1.08%) than H. sabdariffa seeds (17.35%, 18.52%, 25.16%, 3.52%, 4.31%, 44.72%, and 1.57%, respectively). For edible oils, a higher oleic/linoleic (O/L) ratio and lower level of DHSA are preferred, and for industrial oils a high level of VA is preferred. Our results indicate that seeds from H. cannabinus may be of higher quality than H. sabdariffa seeds for these reasons. Significant variability in oil content and major fatty acids was also detected within both species. The variability in oil content and fatty acid composition revealed from this study will be useful for exploring seed utilization and developing new cultivars in these Hibiscus species.

  8. Enhanced in vitro cell activity on silicon-doped vaterite/poly(lactic acid) composites.

    PubMed

    Obata, Akiko; Tokuda, Shingo; Kasuga, Toshihiro

    2009-01-01

    A biodegradable composite with silicon-species releasability was prepared using poly(l-lactic acid) (PLLA) and silicon-doped vaterite (SiV) particles. SiV with particle diameters of approximately 1 mum was prepared using aminopropyltriethoxysilane (APTES) as the silicon species by a carbonation process and then mixed with PLLA in methylene chloride according to a SiV to PLLA weight ratio of 1:2, resulting in the preparation of composite slurry. A composite film was prepared by dipping a cover glass in the slurry. The composite films were incubated in a culture medium for 7 days and the silicon concentration of the medium was measured to estimate the species releasability of the composites. A trace amount of silicon species was continuously released from the composites for 7 days, the amount depending on the content of APTES in SiV. On the composite releasing silicon species, mouse osteoblast-like cells (MC3T3-E1 cells) were significantly stimulated to proliferate and differentiate in comparison with those on a composite containing no silicon species. The proliferation of the cells on the composites releasing larger amounts of silicon species (0.51mgl(-1)day(-1)) was higher than that on the composites releasing smaller amount of the species (0.21mgl(-1)day(-1)). The silicon species in the composites were effective in enhancing the cellular functions. The composites were expected to be useful as a scaffold material for bone tissue engineering.

  9. Electrophoretic deposition of hyaluronic acid and composite films for biomedical applications

    NASA Astrophysics Data System (ADS)

    Ma, R.; Li, Y.; Zhitomirsky, I.

    2010-06-01

    Hyaluronic acid (HYH) is a natural biopolymer, which has tremendous potential for various biomedical applications. Electrophoretic deposition (EPD) methods have been developed for the fabrication of HYH films and composites. New methods for the immobilization of drugs and proteins have been utilized for the fabrication of organic composites. Electrophoretic deposition enabled the fabrication of organic-inorganic composites containing bioceramics and bioglass in the HYH matrix. It was shown that the deposition yield, microstructure, and composition of the films can be controlled. Potential applications of EPD for the surface modification of biomedical implants and fabrication of biosensors are highlighted.

  10. Biodegradable composites from sugar beet pulp and poly(lactic acid).

    PubMed

    Liu, LinShu; Fishman, Marshall L; Hicks, Kevin B; Liu, Cheng-Kung

    2005-11-16

    Sugar beet pulp and poly(lactic acid) (PLA) composites were prepared by compression-heating. The resultant thermoplastics had a lower density, but they had tensile strength similar to that of pure PLA specimens as well as the same geometric properties. Tensile properties depended on the initial water content of sugar beet pulp and the process by which composites were manufactured. In comparison with sugar beet pulp, the composite showed improved water resistance. This can be attributed to the hydrophobic character of PLA and pulp-matrix interactions. The composite thermoplastics showed suitable properties for potential use as lightweight construction materials.

  11. Investigating Students' Reasoning about Acid-Base Reactions

    ERIC Educational Resources Information Center

    Cooper, Melanie M.; Kouyoumdjian, Hovig; Underwood, Sonia M.

    2016-01-01

    Acid-base chemistry is central to a wide range of reactions. If students are able to understand how and why acid-base reactions occur, it should provide a basis for reasoning about a host of other reactions. Here, we report the development of a method to characterize student reasoning about acid-base reactions based on their description of…

  12. Effect of copper on performance, carcass characteristics, and muscle fatty acid composition of meat goat kids.

    PubMed

    Huang, Y L; Wang, Y; Spears, J W; Lin, X; Guo, C H

    2013-10-01

    An experiment was conducted to determine the effects of dietary Cu on performance, carcass characteristics, and muscle fatty acid composition in meat goats. Thirty five Jianyang Big-ear goat (JYB) kids (average BW 20.3 ± 0.6 kg and age 3 to 4 mo) were stratified by weight and randomly assigned to 1 of 7 experimental treatments (n = 5 goats per treatment). Treatments consisted of: 1) control (no supplemental Cu; 14.3 mg Cu/kg DM), 2) 20 mg supplemental Cu/kg DM, 3) 40 mg supplemental Cu/kg DM, 4) 80 mg supplemental Cu/kg DM, 5) 160 mg supplemental Cu/kg DM, 6) 320 mg supplemental Cu/kg DM, and 7) 640 mg supplemental Cu/kg DM. Copper was supplemented from CuSO4•5H2O (25.2% Cu). Goats were individually fed a concentrate-hay based diet for 96 d. Performance was not affected by Cu concentration. Liver Cu concentration was increased (P < 0.01) with Cu supplementation. Goats supplemented with 0 or 20 mg Cu/kg DM had lower (P < 0.01) liver Cu concentrations than the other treatments. Backfat depth (P < 0.01) and intramuscular fat (IMF) content (P < 0.01) were also increased with Cu supplementation. However, Cu-supplemented goats had lower (P = 0.04) longissimus muscle area (LMA) compared with control. Dietary Cu supplementation increased the percentage of C14:0 (P < 0.01), C20:4 (P < 0.01), and total polyunsaturated fatty acids (P = 0.03), decreased C18:1 trans (P = 0.04), and tended to decrease C18:0 (P = 0.08) in LM. Other fatty acids detected were not affected by dietary Cu supplementation (P > 0.10). These results indicate that JYB goats can tolerate up to 640 mg Cu/kg DM for 96 d without adverse effects on performance, but fat deposition and fatty acid composition in the body could be altered by Cu supplementation as low as 20 mg/kg of diet with high concentrate-hay. Copper supplementation increased backfat depth, IMF, and percentage of polyunsaturated fatty acids in LM and decreased LMA in the carcass of JYB goats.

  13. Mechanical and thermal properties of polylactic acid composites reinforced with cellulose nanoparticles extracted from kenaf fibre

    NASA Astrophysics Data System (ADS)

    Ketabchi, Mohammad Reza; Khalid, Mohammad; Thevy Ratnam, Chantara; Walvekar, Rashmi

    2016-12-01

    Different approaches have been attempted to use biomass as filler for production of biodegradable polymer composites. In this study, cellulose nanoparticles (CNP) extracted from kenaf fibres were used to produce polylactic acid (PLA) based biodegradable nanocomposites. CNP concentration was varied from 1-5 wt. % and blended with PLA using Brabender twin-screw compounder. Effects of CNP loading on the mechanical, thermal and dynamic properties of PLA were investigated. Studies on the morphological properties and influence of CNP loading on the properties of CNP/PLA nanocomposite were also conducted. The results show an adequate compatibility between CNP and PLA matrix. Moreover, addition of 3 wt. % of CNP improved the PLA tensile strength by 25%.

  14. Analysis of Known Bacterial Protein Vaccine Antigens Reveals Biased Physical Properties and Amino Acid Composition

    PubMed Central

    Mayers, Carl; Rowe, Sonya; Miller, Julie; Lingard, Bryan; Hayward, Sarah; Titball, Richard W.

    2003-01-01

    Many vaccines have been developed from live attenuated forms of bacterial pathogens or from killed bacterial cells. However, an increased awareness of the potential for transient side-effects following vaccination has prompted an increased emphasis on the use of sub-unit vaccines, rather than those based on whole bacterial cells. The identification of vaccine sub-units is often a lengthy process and bioinformatics approaches have recently been used to identify candidate protein vaccine antigens. Such methods ultimately offer the promise of a more rapid advance towards preclinical studies with vaccines. We have compared the properties of known bacterial vaccine antigens against randomly selected proteins and identified differences in the make-up of these two groups. A computer algorithm that exploits these differences allows the identification of potential vaccine antigen candidates from pathogenic bacteria on the basis of their amino acid composition, a property inherently associated with sub-cellular location. PMID:18629010

  15. Asphaltenes-based polymer nano-composites

    DOEpatents

    Bowen, III, Daniel E

    2013-12-17

    Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

  16. FATTY ACID COMPOSITION AND TOCOPHEROL CONTENT OF PUMPKIN SEED OIL

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pumpkin seed oil (PSO) has high tocopherol content (TC) and unsaturated fatty acids (UFA) making it well-suited for improving human nutrition. PSO has been implicated in preventing prostate growth, retarding hypertension, mitigating hypercholesterolemia and arthritis, improved bladder compliance, a...

  17. Amino acid composition and amino acid-metabolic network in supragingival plaque.

    PubMed

    Washio, Jumpei; Ogawa, Tamaki; Suzuki, Keisuke; Tsukiboshi, Yosuke; Watanabe, Motohiro; Takahashi, Nobuhiro

    2016-01-01

    Dental plaque metabolizes both carbohydrates and amino acids. The former can be degraded to acids mainly, while the latter can be degraded to various metabolites, including ammonia, acids and amines, and associated with acid-neutralization, oral malodor and tissue inflammation. However, amino acid metabolism in dental plaque is still unclear. This study aimed to elucidate what kinds of amino acids are available as metabolic substrates and how the amino acids are metabolized in supragingival plaque, by a metabolome analysis. Amino acids and the related metabolites in supragingival plaque were extracted and quantified comprehensively by CE-TOFMS. Plaque samples were also incubated with amino acids, and the amounts of ammonia and amino acid-related metabolites were measured. The concentration of glutamate was the highest in supragingival plaque, while the ammonia-production was the highest from glutamine. The obtained metabolome profile revealed that amino acids are degraded through various metabolic pathways, including deamination, decarboxylation and transamination and that these metabolic systems may link each other, as well as with carbohydrate metabolic pathways in dental plaque ecosystem. Moreover, glutamine and glutamate might be the main source of ammonia production, as well as arginine, and contribute to pH-homeostasis and counteraction to acid-induced demineralization in supragingival plaque.

  18. Snorkeling preferences foster an amino acid composition bias in transmembrane helices.

    PubMed

    Chamberlain, Aaron K; Lee, Yohan; Kim, Sanguk; Bowie, James U

    2004-05-28

    By analyzing transmembrane (TM) helices in known structures, we find that some polar amino acids are more frequent at the N terminus than at the C terminus. We propose the asymmetry occurs because most polar amino acids are better able to snorkel their polar atoms away from the membrane core at the N terminus than at the C terminus. Two findings lead us to this proposition: (1) side-chain conformations are influenced strongly by the N or C-terminal position of the amino acid in the bilayer, and (2) the favored snorkeling direction of an amino acid correlates well with its N to C-terminal composition bias. Our results suggest that TM helix predictions should incorporate an N to C-terminal composition bias, that rotamer preferences of TM side-chains are position-dependent, and that the ability to snorkel influences the evolutionary selection of amino acids for the helix N and C termini.

  19. Nanostructured bacterial cellulose-poly(4-styrene sulfonic acid) composite membranes with high storage modulus and protonic conductivity.

    PubMed

    Gadim, Tiago D O; Figueiredo, Andrea G P R; Rosero-Navarro, Nataly C; Vilela, Carla; Gamelas, José A F; Barros-Timmons, Ana; Neto, Carlos Pascoal; Silvestre, Armando J D; Freire, Carmen S R; Figueiredo, Filipe M L

    2014-05-28

    The present study reports the development of a new generation of bio-based nanocomposite proton exchange membranes based on bacterial cellulose (BC) and poly(4-styrene sulfonic acid) (PSSA), produced by in situ free radical polymerization of sodium 4-styrenesulfonate using poly(ethylene glycol) diacrylate (PEGDA) as cross-linker, followed by conversion of the ensuing polymer into the acidic form. The BC nanofibrilar network endows the composite membranes with excellent mechanical properties at least up to 140 °C, a temperature where either pure PSSA or Nafion are soft, as shown by dynamic mechanical analysis. The large concentration of sulfonic acid groups in PSSA is responsible for the high ionic exchange capacity of the composite membranes, reaching 2.25 mmol g(-1) for a composite with 83 wt % PSSA/PEGDA. The through-plane protonic conductivity of the best membrane is in excess of 0.1 S cm(-1) at 94 °C and 98% relative humidity (RH), decreasing to 0.042 S cm(-1) at 60% RH. These values are comparable or even higher than those of ionomers such as Nafion or polyelectrolytes such as PSSA. This combination of electric and viscoelastic properties with low cost underlines the potential of these nanocomposites as a bio-based alternative to other polymer membranes for application in fuel cells, redox flow batteries, or other devices requiring functional proton conducting elements, such as sensors and actuators.

  20. Composition of fatty acids triacylglycerols and unsaponifiable matter in Calophyllum calaba L. oil from Guadeloupe.

    PubMed

    Crane, Sylvie; Aurore, Guylène; Joseph, Henry; Mouloungui, Zéphirin; Bourgeois, Paul

    2005-08-01

    The composition of the kernel oils of two Calophyllum species (Calophyllum calaba L. and Calophyllum inophyllum L.) was investigated. The physico-chemical properties and fatty acid composition of the kernel oils were examined. In two species, oleic acid C18:1 (39.1-50%) is the dominating fatty acid followed by linoleic acid C18:2 (21.7-31.1%) as the second major fatty acid. Stearic C18:0 (13.4-14.3%) and palmitic C16:0 (11-13.7%) acids are the major saturates. The oils contains an appreciable amount of unsaturated fatty acids (70.8-73.10%). Most of the fatty acids are present as triacylglycerol (76.7-84%), twenty one triacylglycerols are detected with predominantly unsaturated triacylglycerols. The total unsaponifiable content, its general composition and the identity of the components of the sterol and tocopherol fractions are presented. In both species, analysis of the unsaponifiable fractions revealed the preponderance of phytosterols, mainly stigmasterol (35.8-45.1%) and beta-sitosterol (41.1-43.1%). Among the eight tocopherols and tocotrienols present in two species, variations exist; alpha-tocopherol (183 mg/kg) is the main tocopherol in Calophyllum calaba L. and Delta-tocotrienol (236 mg/kg) is the dominant tocotrienol in Calophyllum inophyllum L.

  1. Gamma-irradiation effect on a commercial composite anticorrosive pigment and acidity-to-alkalinity conversion

    NASA Astrophysics Data System (ADS)

    Song, Weiqiang; Niu, Kaihui; Wu, Longchao

    2016-05-01

    A commercial composite anticorrosive pigment based on aluminum dihydrogen tripolyphosphate was studied after exposure to gamma irradiation (Co60, 0, 20, 50, 100 and 150 kGy) using FTIR, XRD, TGA and acid-base titration technologies. Although the FTIR spectra showed that the effect of the irradiation on functional groups in the pigments was not obvious, the decrease in the crystal lattice parameters of the irradiated pigments was observed in the XRD spectra compared to the non-irradiated sample. But the extent of the lattice parameter decrease monotonically with the increase of absorbed dose from 20 to 150 kGy, which was attributed to the decomposition of water and the simultaneous occurrence of lattice damage when the pigments were exposed to gamma rays. Of particular significance was the displayed basicity of the aqueous solutions of the irradiated pigments compared to the acidity of the solution of the non-irradiated pigment, which was attributed to the decomposition of P-OH groups (combined water).

  2. Microbiota transplantation restores normal fecal bile acid composition in recurrent Clostridium difficile infection.

    PubMed

    Weingarden, Alexa R; Chen, Chi; Bobr, Aleh; Yao, Dan; Lu, Yuwei; Nelson, Valerie M; Sadowsky, Michael J; Khoruts, Alexander

    2014-02-15

    Fecal microbiota transplantation (FMT) has emerged as a highly effective therapy for refractory, recurrent Clostridium difficile infection (CDI), which develops following antibiotic treatments. Intestinal microbiota play a critical role in the metabolism of bile acids in the colon, which in turn have major effects on the lifecycle of C. difficile bacteria. We hypothesized that fecal bile acid composition is altered in patients with recurrent CDI and that FMT results in its normalization. General metabolomics and targeted bile acid analyses were performed on fecal extracts from patients with recurrent CDI treated with FMT and their donors. In addition, 16S rRNA gene sequencing was used to determine the bacterial composition of pre- and post-FMT fecal samples. Taxonomic bacterial composition of fecal samples from FMT recipients showed rapid change and became similar to the donor after the procedure. Pre-FMT fecal samples contained high concentrations of primary bile acids and bile salts, while secondary bile acids were nearly undetectable. In contrast, post-FMT fecal samples contained mostly secondary bile acids, as did non-CDI donor samples. Therefore, our analysis showed that FMT resulted in normalization of fecal bacterial community structure and metabolic composition. Importantly, metabolism of bile salts and primary bile acids to secondary bile acids is disrupted in patients with recurrent CDI, and FMT corrects this abnormality. Since individual bile salts and bile acids have pro-germinant and inhibitory activities, the changes suggest that correction of bile acid metabolism is likely a major mechanism by which FMT results in a cure and prevents recurrence of CDI.

  3. Template engaged synthesis of hollow ceria-based composites

    NASA Astrophysics Data System (ADS)

    Chen, Guozhu; Rosei, Federico; Ma, Dongling

    2015-03-01

    Hollow ceria-based composites, which consist of noble metal nanoparticles or metal oxides as a secondary component, are being studied extensively for potential applications in heterogeneous catalysis. This is due to their unique features, which exhibit the advantages of a hollow structure (e.g. high surface area and low weight), and also integrate the properties of ceria and noble metals/metal oxides. More importantly, the synergistic effect between constituents in hollow ceria-based composites has been demonstrated in various catalytic reactions. In this feature article, we summarize the state-of-the-art in the synthesis of hollow ceria-based composites, including traditional hard-templates and more recently, sacrificial-template engaged strategies, highlighting the key role of selected templates in the formation of hollow composites. In addition, the catalytic applications of hollow ceria-based composites are briefly surveyed. Finally, challenges and perspectives on future advances of hollow ceria-based composites are outlined.

  4. Template engaged synthesis of hollow ceria-based composites.

    PubMed

    Chen, Guozhu; Rosei, Federico; Ma, Dongling

    2015-03-19

    Hollow ceria-based composites, which consist of noble metal nanoparticles or metal oxides as a secondary component, are being studied extensively for potential applications in heterogeneous catalysis. This is due to their unique features, which exhibit the advantages of a hollow structure (e.g. high surface area and low weight), and also integrate the properties of ceria and noble metals/metal oxides. More importantly, the synergistic effect between constituents in hollow ceria-based composites has been demonstrated in various catalytic reactions. In this feature article, we summarize the state-of-the-art in the synthesis of hollow ceria-based composites, including traditional hard-templates and more recently, sacrificial-template engaged strategies, highlighting the key role of selected templates in the formation of hollow composites. In addition, the catalytic applications of hollow ceria-based composites are briefly surveyed. Finally, challenges and perspectives on future advances of hollow ceria-based composites are outlined.

  5. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and fatty acids: Implications for atmospheric processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Zhang, Yan-Lin; Kawamura, Kimitaka; Cao, Fang; Lee, Meehye

    2016-04-01

    Stable carbon isotopic compositions (δ13C) were measured for 23 individual organic species including 9 dicarboxylic acids, 7 oxocarboxylic acids, 1 tricarboxylic acid, 2 α-dicarbonyls, and 4 fatty acids in the aerosols from Gosan background site in East Asia. δ13C values of particle phase glyoxal and methylglyoxal are significantly larger than those previously reported for isoprene and other precursors. The values are consistently less negative in oxalic acid (C2, average -14.1‰), glyoxylic acid (-13.8‰), pyruvic acid (-19.4‰), glyoxal (-13.5‰), and methylglyoxal (-18.6‰) compared to other organic species (e.g., palmitic acid, -26.3‰), which can be explained by the kinetic isotope effects during atmospheric oxidation of pre-aged precursors (e.g., isoprene) and the subsequent gas-particle partitioning after the evaporation of clouds or wet aerosols. The δ13C values of C2 is positively correlated with C2 to organic carbon ratio, indicating that photochemical production of C2 is more pronounced than its degradation during long-range atmospheric transport. The isotopic results also suggest that aqueous phase oxidation of glyoxal and methylglyoxal is a major formation process of oxalic acid via the intermediates such as glyoxylic acid and pyruvic acid. This study provides evidence that organic aerosols are intensively photochemically aged in the western North Pacific rim.

  6. Effect of dietary starch or micro algae supplementation on rumen fermentation and milk fatty acid composition of dairy cows.

    PubMed

    Boeckaert, C; Vlaeminck, B; Dijkstra, J; Issa-Zacharia, A; Van Nespen, T; Van Straalen, W; Fievez, V

    2008-12-01

    Two experiments with rumen-fistulated dairy cows were conducted to evaluate the effects of feeding docosahexaenoic acid (DHA; C22:6 n-3)-enriched diets or diets provoking a decreased rumen pH on milk fatty acid composition. In the first experiment, dietary treatments were tested during 21-d experimental periods in a 4 x 4 Latin square design. Diets included a control diet, a starch-rich diet, a bicarbonate-buffered starch-rich diet, and a diet supplemented with DHA-enriched micro algae [Schizochytrium sp., 43.0 g/kg of dry matter intake (DMI)]. Algae were supplemented directly through the rumen fistula. The total mixed ration consisted of grass silage, corn silage, soybean meal, and a standard or glucogenic concentrate. The glucogenic and buffered glucogenic diet had no effect on rumen fermentation and milk fatty acid composition because, unexpectedly, no reduced rumen pH was detected. The algae diet had no effect on rumen pH but provoked decreased butyrate and increased isovalerate molar proportions in the rumen. In addition, algae supplementation affected rumen biohydrogenation of linoleic and linolenic acid as reflected in the modified milk fatty acid composition toward increased conjugated linoleic acid (CLA) cis-9 trans-11, CLA trans-9 cis-11, C18:1 trans-10, C18:1 trans-11, and C22:6 n-3 concentrations. Concomitantly, on average, a 45% decrease in DMI and milk yield was observed. Based on these drastic and impractical results, a second animal experiment was performed for 20 d in which 9.35 g/kg of total DMI of algae were incorporated in the concentrate and supplemented to 3 rumen-fistulated cows. Algae concentrate feeding increased rumen pH, which was associated with decreased rumen short-chain fatty acid concentrations. Moreover, a different shift in rumen short-chain fatty acid proportions was observed compared with the first experiment because molar proportions of butyrate, isobutyrate, and isovalerate increased, whereas acetate molar proportion decreased

  7. CUTANEOUS DELIVERY OF α-TOCOPHEROL AND LIPOIC ACID USING MICROEMULSIONS: INFLUENCE OF COMPOSITION AND CHARGE

    PubMed Central

    Cichewicz, Allie; Pacleb, Chelsea; Connors, Ashley; Hass, Martha A.; Lopes, Luciana B.

    2013-01-01

    Objectives To assess whether the composition and charge of microemulsions affect their ability to simultaneously deliver α-tocopherol and lipoic acid into viable skin layers. Methods α-tocopherol and lipoic acid were added (1.1 and 0.5% w/w, respectively) to decylglucoside-based microemulsions containing mono-dicaprylin. Microemulsions containing surfactant:oil:water (w/w/w) at 60:30:10 (ME-O) and 46:23:31 (ME-W), as well as a cationic form of ME-W containing 1% phytosphingosine (ME-Wphy) were characterized, and their ability to disrupt the skin barrier and deliver the antioxidants in vitro in the skin was evaluated. Antioxidant activity in ME-Wphy-treated skin was assessed using the thiobarbituric acid-reactive substances (TBARS) assay. Key findings internal phase diameters of microemulsions ranged between 47.0–53.2 nm; phytosphingosine addition and pH adjustment to 5.0 increased zeta potential from −4.3 to +29.1 mV. ME-O displayed w/o structure, whereas ME-W and ME-Wphy were consistent with o/w. Microemulsions affected skin electrical resistance and transepidermal water loss, but did not affect lipoic acid penetration. α-Tocopherol delivery increased following the order ME-O

  8. Flexible hydrogel-based functional composite materials

    DOEpatents

    Song, Jie; Saiz, Eduardo; Bertozzi, Carolyn R; Tomasia, Antoni P

    2013-10-08

    A composite having a flexible hydrogel polymer formed by mixing an organic phase with an inorganic composition, the organic phase selected from the group consisting of a hydrogel monomer, a crosslinker, a radical initiator, and/or a solvent. A polymerization mixture is formed and polymerized into a desired shape and size.

  9. A magnetoelectric composite based microwave phase shifter

    NASA Astrophysics Data System (ADS)

    Bichurin, M. I.; Petrov, V. M.; Srinivasan, G.

    2008-03-01

    Magnetoelectric (ME) properties of ferrite-ferroelectric composites arise from their response to elastic and electromagnetic force fields. The unique combination of magnetic, electrical, and ME interactions opens up the possibility of electric field tunable ferromagnetic resonance (FMR) based devices [1]. Here we discuss an ME phase shifter operating in the FMR region at 9.3 GHz. A slot line on a yttrium iron garnet film bonded to lead zirconate titanate (PZT) provides a basis for the phase shifter. The circularly polarized microwave magnetic field of the slot line interacts with the ferrite and causes variation of phase velocity with the controlling magnetic and electric fields. Electrical tuning is realized with the application of a control voltage due to PZT. The estimated phase shift per unit length and unit voltage is to 20 deg/cm kV for a PZT thickness of 0.5 mm. 1 S. Shastry and G. Srinivasan, M.I. Bichurin, V.M. Petrov, A.S. Tatarenko. Phys. Rev. B, 70 064416 (2004). - supported by grants from the Office of Naval Research and the Russian Foundation for Basic Research.

  10. Heat expanded starch-based compositions.

    PubMed

    Glenn, Gregory M; Klamczynski, Artur K; Holtman, Kevin M; Shey, Justin; Chiou, Bor-Sen; Berrios, Jose; Wood, Delilah; Orts, William J; Imam, Syed H

    2007-05-16

    A heat expansion process similar to that used for expanded bead polystyrene was used to expand starch-based compositions. Foam beads made by solvent extraction had the appearance of polystyrene beads but did not expand when heated due to an open-cell structure. Nonporous beads, pellets, or particles were made by extrusion or by drying and milling cooked starch slurries. The samples expanded into a low-density foam by heating 190-210 degrees C for more than 20 s at ambient pressures. Formulations containing starch (50-85%), sorbitol (5-15%), glycerol (4-12%), ethylene vinyl alcohol (EVAL, 5-15%), and water (10-20%) were studied. The bulk density was negatively correlated to sorbitol, glycerol, and water content. Increasing the EVAL content increased the bulk density, especially at concentrations higher than 15%. Poly(vinyl alcohol) (PVAL) increased the bulk density more than EVAL. The bulk density was lowest in samples made of wheat and potato starch as compared to corn starch. The expansion temperature for the starch pellets decreased more than 20 degrees C as the moisture content was increased from 10 to 25%. The addition of EVAL in the formulations decreased the equilibrium moisture content of the foam and reduced the water absorption during a 1 h soaking period.

  11. Characterization of Fatty Acid Composition in Bone Marrow Fluid From Postmenopausal Women: Modification After Hip Fracture.

    PubMed

    Miranda, Melissa; Pino, Ana María; Fuenzalida, Karen; Rosen, Clifford J; Seitz, Germán; Rodríguez, J Pablo

    2016-10-01

    Bone marrow adipose tissue (BMAT) is associated with low bone mass, although the functional consequences for skeletal maintenance of increased BMAT are currently unclear. BMAT might have a role in systemic energy metabolism, and could be an energy source as well as an endocrine organ for neighboring bone cells, releasing cytokines, adipokines and free fatty acids into the bone marrow microenvironment. The aim of the present report was to compare the fatty acid composition in the bone marrow supernatant fluid (BMSF) and blood plasma of postmenopausal women women (65-80 years old). BMSF was obtained after spinning the aspirated bone marrow samples; donors were classified as control, osteopenic or osteoporotic after dual-energy X-ray absorptiometry. Total lipids from human bone marrow fluid and plasma were extracted, converted to the corresponding methyl esters, and finally analyzed by a gas chromatographer coupled with a mass spectrometer. Results showed that fatty acid composition in BMSF was dynamic and distinct from blood plasma, implying significance in the locally produced lipids. The fatty acid composition in the BMSF was enriched in saturated fatty acid and decreased in unsaturated fatty acids as compared to blood plasma, but this relationship switched in women who suffered a hip fracture. On the other hand, there was no relationship between BMSF and bone mineral density. In conclusion, lipid composition of BMSF is distinct from the circulatory compartment, most likely reflecting the energy needs of the marrow compartment. J. Cell. Biochem. 117: 2370-2376, 2016. © 2016 Wiley Periodicals, Inc.

  12. An Introductory Laboratory Exercise for Acids and Bases.

    ERIC Educational Resources Information Center

    Miller, Richard; Silberman, Robert

    1986-01-01

    Discusses an acid-base neutralization exercise requiring groups of students to determine: (1) combinations of solutions giving neutralization; (2) grouping solutions as acids or bases; and (3) ranking groups in order of concentration. (JM)

  13. The Bronsted-Lowery Acid-Base Concept.

    ERIC Educational Resources Information Center

    Kauffman, George B.

    1988-01-01

    Gives the background history of the simultaneous discovery of acid-base relationships by Johannes Bronsted and Thomas Lowry. Provides a brief biographical sketch of each. Discusses their concept of acids and bases in some detail. (CW)

  14. Effect of casein-based semi-synthetic food on renal acid excretion and acid-base state of blood in dogs.

    PubMed

    Zijlstra, W G; Langbroek, A J; Kraan, J; Rispens, P; Nijmeijer, A

    1995-01-01

    Urinary acid excretion and blood acid-base state were determined in dogs fed a casein-based semi-synthetic food (SSF), to which different amounts of salts had been added, in comparison with feeding normal dog food. Net acid excretion (NAE) and inorganic acid excretion (IAE) increased during SSF feeding. IAE was higher than the acid load calculated from the sulphur and phosphorus content of the casein. This higher IAE appeared to be due to the presence of calcium and magnesium phosphate in the diet, because calcium and magnesium may be in part precipitated as carbonate, leaving phosphate to be absorbed as phosphoric acid. Acid excretion decreased by addition of CaO. When no neutral Na+ and K+ salts were added, the increase in NAE was accompanied by a metabolic acidosis. K+ was more effective in attenuating the acidosis than Na+. On the basis of these findings a diet can be made which imposes a known acid load, and provides stable baseline values. Hence, any additions that influence the acid-base balance can be properly studied. The data obtained in these and future studies utilising this diet may be of help in optimising the composition of nutrient solutions to be used in the care of critically ill patients.

  15. Fatty acid, amino acid, and mineral composition of four common vetch seeds on Qinghai-Tibetan plateau.

    PubMed

    Mao, Zhuxin; Fu, Hua; Nan, Zhibiao; Wan, Changgui

    2015-03-15

    The chemical composition of four common vetch (Vicia sativa L.) seeds was investigated to determine their nutrition value. The result shows that the seeds are low in lipid (1.55-2.74% of dry weight), and high in the unsaturated fatty acid (74.51-77.36% of total fatty acid). The ratio of essential amino acid to non-essential amino acid (0.62-0.69) is even higher than the amount (0.38) recommended by World Health Organization. Besides, the seeds are also found rich in Mg, Mn and Cu, but with a low ratio of Ca to P (0.24-0.73), which may increase the risk of the mineral element toxicity. The results indicate that the four common vetch seeds could be taken as an alternative food source, but the possible toxic effect should be taken into consideration.

  16. The physiological assessment of acid-base balance.

    PubMed

    Howorth, P J

    1975-04-01

    Acid-base terminology including the sue of SI units is reviewed. The historical reasons why nomograms have been particularly used in acid-base work are discussed. The theoretical basis of the Henderson-Hasselbalch equation is considered. It is emphasized that the solubility of CO2 in plasma and the apparent first dissociation constant of carbonic acid are not chemical constants when applied to media of uncertain and varying composition such as blood plasma. The use of the Henderson-Hasselbalch equation in making hypothermia corrections for PCO2 is discussed. The Astrup system for the in vitro determination of blood gases and derived parameters is described and the theoretical weakness of the base excess concept stressed. A more clinically-oriented approach to the assessment of acid-base problems is presented. Measurement of blood [H+] and PCO2 are considered to be primary data which should be recorded on a chart with in vivo CO2-titration lines (see below). Clinical information and results of other laboratory investigations such as plasma bicarbonate, PO2,P50 are then to be considered together with the primary data. In order to interpret this combined information it is essential to take into account the known ventilatory response to metabolic acidosis and alkalosis, and the renal response to respiratory acidosis and alkalosis. The use is recommended of a chart showing the whole-body CO2-titration points obtained when patients with different initial levels of non-respiratory [H+] are ventilated. A number of examples are given of the use of this [H+] and PCO2 in vivo chart in the interpretation of acid-base data. The aetiology, prognosis and treatment of metabolic alkalosis is briefly reviewed. Treatment with intravenous acid is recommended for established cases. Attention is drawn to the possibility of iatrogenic production of metabolic alkalosis. Caution is expressed over the use of intravenous alkali in all but the severest cases of metabolic acidosis. The role of

  17. Cd(II) Sorption on Montmorillonite-Humic acid-Bacteria Composites

    NASA Astrophysics Data System (ADS)

    Du, Huihui; Chen, Wenli; Cai, Peng; Rong, Xingmin; Dai, Ke; Peacock, Caroline L.; Huang, Qiaoyun

    2016-01-01

    Soil components (e.g., clays, bacteria and humic substances) are known to produce mineral-organic composites in natural systems. Herein, batch sorption isotherms, isothermal titration calorimetry (ITC), and Cd K-edge EXAFS spectroscopy were applied to investigate the binding characteristics of Cd on montmorillonite(Mont)-humic acid(HA)-bacteria composites. Additive sorption and non-additive Cd(II) sorption behaviour is observed for the binary Mont-bacteria and ternary Mont-HA-bacteria composite, respectively. Specifically, in the ternary composite, the coexistence of HA and bacteria inhibits Cd adsorption, suggesting a “blocking effect” between humic acid and bacterial cells. Large positive entropies (68.1 ~ 114.4 J/mol/K), and linear combination fitting of the EXAFS spectra for Cd adsorbed onto Mont-bacteria and Mont-HA-bacteria composites, demonstrate that Cd is mostly bound to bacterial surface functional groups by forming inner-sphere complexes. All our results together support the assertion that there is a degree of site masking in the ternary clay mineral-humic acid-bacteria composite. Because of this, in the ternary composite, Cd preferentially binds to the higher affinity components-i.e., the bacteria.

  18. Cd(II) Sorption on Montmorillonite-Humic acid-Bacteria Composites

    PubMed Central

    Du, Huihui; Chen, Wenli; Cai, Peng; Rong, Xingmin; Dai, Ke; Peacock, Caroline L.; Huang, Qiaoyun

    2016-01-01

    Soil components (e.g., clays, bacteria and humic substances) are known to produce mineral-organic composites in natural systems. Herein, batch sorption isotherms, isothermal titration calorimetry (ITC), and Cd K-edge EXAFS spectroscopy were applied to investigate the binding characteristics of Cd on montmorillonite(Mont)-humic acid(HA)-bacteria composites. Additive sorption and non-additive Cd(II) sorption behaviour is observed for the binary Mont-bacteria and ternary Mont-HA-bacteria composite, respectively. Specifically, in the ternary composite, the coexistence of HA and bacteria inhibits Cd adsorption, suggesting a “blocking effect” between humic acid and bacterial cells. Large positive entropies (68.1 ~ 114.4 J/mol/K), and linear combination fitting of the EXAFS spectra for Cd adsorbed onto Mont-bacteria and Mont-HA-bacteria composites, demonstrate that Cd is mostly bound to bacterial surface functional groups by forming inner-sphere complexes. All our results together support the assertion that there is a degree of site masking in the ternary clay mineral-humic acid-bacteria composite. Because of this, in the ternary composite, Cd preferentially binds to the higher affinity components-i.e., the bacteria. PMID:26792640

  19. Coronavirus phylogeny based on triplets of nucleic acids bases

    NASA Astrophysics Data System (ADS)

    Liao, Bo; Liu, Yanshu; Li, Renfa; Zhu, Wen

    2006-04-01

    We considered the fully overlapping triplets of nucleotide bases and proposed a 2D graphical representation of protein sequences consisting of 20 amino acids and a stop code. Based on this 2D graphical representation, we outlined a new approach to analyze the phylogenetic relationships of coronaviruses by constructing a covariance matrix. The evolutionary distances are obtained through measuring the differences among the two-dimensional curves.

  20. Mathematical modeling of acid-base physiology

    PubMed Central

    Occhipinti, Rossana; Boron, Walter F.

    2015-01-01

    pH is one of the most important parameters in life, influencing virtually every biological process at the cellular, tissue, and whole-body level. Thus, for cells, it is critical to regulate intracellular pH (pHi) and, for multicellular organisms, to regulate extracellular pH (pHo). pHi regulation depends on the opposing actions of plasma-membrane transporters that tend to increase pHi, and others that tend to decrease pHi. In addition, passive fluxes of uncharged species (e.g., CO2, NH3) and charged species (e.g., HCO3− , NH4+) perturb pHi. These movements not only influence one another, but also perturb the equilibria of a multitude of intracellular and extracellular buffers. Thus, even at the level of a single cell, perturbations in acid-base reactions, diffusion, and transport are so complex that it is impossible to understand them without a quantitative model. Here we summarize some mathematical models developed to shed light onto the complex interconnected events triggered by acids-base movements. We then describe a mathematical model of a spherical cell–which to our knowledge is the first one capable of handling a multitude of buffer reaction–that our team has recently developed to simulate changes in pHi and pHo caused by movements of acid-base equivalents across the plasma membrane of a Xenopus oocyte. Finally, we extend our work to a consideration of the effects of simultaneous CO2 and HCO3− influx into a cell, and envision how future models might extend to other cell types (e.g., erythrocytes) or tissues (e.g., renal proximal-tubule epithelium) important for whole-body pH homeostasis. PMID:25617697

  1. Bipolar Membranes for Acid Base Flow Batteries

    NASA Astrophysics Data System (ADS)

    Anthamatten, Mitchell; Roddecha, Supacharee; Jorne, Jacob; Coughlan, Anna

    2011-03-01

    Rechargeable batteries can provide grid-scale electricity storage to match power generation with consumption and promote renewable energy sources. Flow batteries offer modular and flexible design, low cost per kWh and high efficiencies. A novel flow battery concept will be presented based on acid-base neutralization where protons (H+) and hydroxyl (OH-) ions react electrochemically to produce water. The large free energy of this highly reversible reaction can be stored chemically, and, upon discharge, can be harvested as usable electricity. The acid-base flow battery concept avoids the use of a sluggish oxygen electrode and utilizes the highly reversible hydrogen electrode, thus eliminating the need for expensive noble metal catalysts. The proposed flow battery is a hybrid of a battery and a fuel cell---hydrogen gas storing chemical energy is produced at one electrode and is immediately consumed at the other electrode. The two electrodes are exposed to low and high pH solutions, and these solutions are separated by a hybrid membrane containing a hybrid cation and anion exchange membrane (CEM/AEM). Membrane design will be discussed, along with ion-transport data for synthesized membranes.

  2. Effect of oilseed type on milk fatty acid composition of individual cows, and also bulk tank milk fatty acid composition from commercial farms.

    PubMed

    Kliem, K E; Humphries, D J; Reynolds, C K; Morgan, R; Givens, D I

    2017-02-01

    Supplementing dairy cow diets with oilseed preparations has been shown to replace milk saturated fatty acids (SFA) with mono- and/or polyunsaturated fatty acids (MUFA, PUFA), which may reduce risk factors associated with cardio-metabolic diseases in humans consuming milk and dairy products. Previous studies demonstrating this are largely detailed, highly controlled experiments involving small numbers of animals, but in order to transfer this feeding strategy to commercial situations further studies are required involving whole herds varying in management practices. In experiment 1, three oilseed supplements (extruded linseed (EL), calcium salts of palm and linseed oil (CPLO) and milled rapeseed (MR)) were included in grass silage-based diets formulated to provide cows with ~350 g oil/day, and compared with a negative control (Control) diet containing no supplemental fat, and a positive control diet containing 350 g/cow per day oil as calcium salt of palm oil distillate (CPO). Diets were fed for 28-day periods in a 5×4 Latin Square design, and milk production, composition and fatty acid (FA) profile were analysed at the end of each period. Compared with Control, all lipid supplemented diets decreased milk fat SFA concentration by an average of 3.5 g/100 g FA, by replacement with both cis- and trans-MUFA/PUFA. Compared with CPO, only CPLO and MR resulted in lower milk SFA concentrations. In experiment 2, 24 commercial dairy farms (average herd size±SEM 191±19.3) from the south west of the United Kingdom were recruited and for a 1 month period asked to supplement their herd diets with either CPO, EL, CPLO or MR at the same inclusion level as the first study. Bulk tank milk was analysed weekly to determine FA concentration by Fourier Transform mid-IR spectroscopy prediction. After 4 weeks, EL, CPLO and MR all decreased herd milk SFA and increased MUFA to a similar extent (average -3.4 and +2.4 g/100 g FA, respectively) when compared with CPO. Differing responses

  3. Biocompatibility and characterization of polylactic acid/styrene-ethylene-butylene-styrene composites.

    PubMed

    Tsou, Chi-Hui; Kao, Bo-Jyue; Yang, Ming-Chien; Suen, Maw-Cherng; Lee, Yi-Hsuan; Chen, Jui-Chin; Yao, Wei-Hua; Lin, Shang-Ming; Tsou, Chih-Yuan; Huang, Shu-Hsien; De Guzman, Manuel; Hung, Wei-Song

    2015-01-01

    Polylactic acid (PLA)/styrene-ethylene-butylene-styrene (SEBS) composites were prepared by melt blending. Differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WXRD) were used to characterize PLA and PLA/SEBS composites in terms of their melting behavior and crystallization. Curves from thermal gravimetric analysis (TGA) illustrated that thermostability increased with SEBS content. Further morphological analysis of PLA/SEBS composites revealed that SEBS molecules were not miscible with PLA molecules in PLA/SEBS composites. The tensile testing for PLA and PLA/SEBS composites showed that the elongation at the break was enhanced, but tensile strength decreased with increasing SEBS content. L929 fibroblast cells were chosen to assess the cytocompatibility; the cell growth of PLA was found to decrease with increasing SEBS content. This study proposes possible reasons for these properties of PLA/SEBS composites.

  4. Properties of polylactic acid composites reinforced with oil palm biomass microcrystalline cellulose.

    PubMed

    Haafiz, M K Mohamad; Hassan, Azman; Zakaria, Zainoha; Inuwa, I M; Islam, M S; Jawaid, M

    2013-10-15

    In this work, polylactic acid (PLA) composites filled with microcrystalline cellulose (MCC) from oil palm biomass were successfully prepared through solution casting. Fourier transform infrared (FT-IR) spectroscopy indicates that there are no significant changes in the peak positions, suggesting that incorporation of MCC in PLA did not result in any significant change in chemical structure of PLA. Thermogravimetric analysis was conducted on the samples. The T50 decomposition temperature improved with addition of MCC, showing increase in thermal stability of the composites. The synthesized composites were characterized in terms of tensile properties. The Young's modulus increased by about 30%, while the tensile strength and elongation at break for composites decreased with addition of MCC. Scanning electron microscopy (SEM) of the composites fractured surface shows that the MCC remained as aggregates of crystalline cellulose. Atomic force microscopy (AFM) topographic image of the composite surfaces show clustering of MCC with uneven distribution.

  5. Prebiotic syntheses of vitamin coenzymes: II. Pantoic acid, pantothenic acid, and the composition of coenzyme A

    NASA Technical Reports Server (NTRS)

    Miller, S. L.; Schlesinger, G.

    1993-01-01

    Pantoic acid can by synthesized in good prebiotic yield from isobutyraldehyde or alpha-ketoisovaleric acid + H2CO + HCN. Isobutyraldehyde is the Strecker precursor to valine and alpha-ketoisovaleric acid is the valine transamination product. Mg2+ and Ca2+ as well as several transition metals are catalysts for the alpha-ketoisovaleric acid reaction. Pantothenic acid is produced from pantoyl lactone (easily formed from pantoic acid) and the relatively high concentrations of beta-alanine that would be formed on drying prebiotic amino acid mixtures. There is no selectivity for this reaction over glycine, alanine, or gamma-amino butyric acid. The components of coenzyme A are discussed in terms of ease of prebiotic formation and stability and are shown to be plausible choices, but many other compounds are possible. The gamma-OH of pantoic acid needs to be capped to prevent decomposition of pantothenic acid. These results suggest that coenzyme A function was important in the earliest metabolic pathways and that the coenzyme A precursor contained most of the components of the present coenzyme.

  6. Magnetoimpedance of cobalt-based amorphous ribbons/polymer composites

    NASA Astrophysics Data System (ADS)

    Semirov, A. V.; Derevyanko, M. S.; Bukreev, D. A.; Moiseev, A. A.; Kudryavtsev, V. O.; Safronov, A. P.

    2016-10-01

    The combined influence of the temperature, the elastic tensile stress and the external magnetic field on the total impedance and impedance components were studied for rapidly quenched amorphous Co75Fe5Si4B16 ribbons. Both as-cast amorphous ribbons and Co75Fe5Si4B16/polymer amorphous ribbon based composites were considered. Following polymer coverings were studied: modified rubber solution in o-xylene, solution of butyl methacrylate and methacrylic acid copolymer in isopropanol and solution of polymethylphenylsiloxane resin in toluene. All selected composites showed very good adhesion of the coverings and allowed to provide temperature measurements from 163 K up to 383 K under the applied deforming tensile force up to 30 N. The dependence of the modulus of the impedance and its components on the external magnetic field was influenced by the elastic tensile stresses and was affected by the temperature of the samples. It was shown that maximal sensitivity of the impedance and its components to the external magnetic field was observed at minimal temperature and maximal deforming force depended on the frequency of an alternating current.

  7. Genome-wide association study for carcass traits, fatty acid composition, chemical composition, sugar, and the effects of related candidate genes in Japanese Black cattle.

    PubMed

    Sasago, Nanae; Abe, Tsuyoshi; Sakuma, Hironori; Kojima, Takatoshi; Uemoto, Yoshinobu

    2017-01-01

    We performed a genome-wide association study (GWAS) and candidate gene analysis to: (i) evaluate the effectiveness of the GWAS in our small population by performing GWAS for carcass weight (CW) and fatty acid composition; (ii) detect novel candidate regions affecting non-CW carcass traits, chemical composition and sugar; and (iii) evaluate the association of the candidate genes previously detected in CW and fatty acid composition with other economically important traits. A total of 574 Japanese Black cattle and 40 657 Single nucleotide polymorphisms were used. In addition, candidate gene analyses were performed to evaluate the association of three CW-related genes and two fatty acid-related genes with carcass traits, fatty acid composition, chemical composition and sugar. The significant regions with the candidate genes were detected for CW and fatty acid composition, and these results showed that a significant region would be detectable despite the small sample size. The novel candidate regions were detected on BTA23 for crude protein and on BTA19 for fructose. CW-related genes associated with the rib-eye area and fatty acid composition were identified, and fatty acid-related genes had no relationship with other traits. Moreover, the favorable allele of CW-related genes had an unfavorable effect on fatty acid composition.

  8. Novel light emissive yttrium-based nanoparticles and composites

    NASA Astrophysics Data System (ADS)

    Hill, Laura Burka

    place between the nanoparticles and the sol-gel medium. Stability of nanoparticles in suspension was overcome through the control of pH during sol-gel synthesis. Through both base- and/or acid-catalysis, we produced optically active nanoparticle doped sol-gel composites containing YAG and Yttria. Our results indicated no detrimental effect on the nanoparticles upon incorporation into the sol-gel matrix; this was demonstrated through XRD, where no silicate phases were observed, through EDX, where we saw no diffusion of yttrium into the sol-gel and no silicon diffusing into the nanoparticles, and through photoluminescence, where emissions were consistent with that of the as-made nanoparticles. These results led us to theorize that the nanoparticles, rather than being bonded to the matrix, are seated in the void space that is prevalent in sol-gel systems. Additionally, these materials are stable at much higher temperatures than current resin-based systems.

  9. Amino acid composition determined using multiple hydrolysis times for three goat milk formulations.

    PubMed

    Rutherfurd, Shane M; Moughan, Paul J; Lowry, Dianne; Prosser, Colin G

    2008-01-01

    The amino acid composition of goat milk formulations with varying protein and carbohydrate concentrations were determined. Proteins in goat milk infant formula, goat milk growing-up formula and goat whole milk powder were hydrolysed using multiple hydrolysis time intervals. A least-squares non-linear regression model was used to predict the free and protein bound amino acid concentrations. The amino acid composition of goat infant formula was compared with human milk reference values. There was good agreement between the multiple hydrolysis and single 24-h hydrolysis methods for approximately one-half of the amino acids. Tryptophan, aspartic acid, threonine, tyrosine, isoleucine, valine, serine and alanine contents were underestimated by 10.6, 5.6, 5.6, 4.7, 4.4, 3.7, 3.7 and 3.6%, respectively, by the single 24-h hydrolysis. The study provides accurate reference data on the amino acid composition of goat milk powders. Goat milk infant formula has amino acids in amounts similar to human milk reference values, when expressed on a per-energy basis.

  10. Phenolic acid induced growth of gold nanoshells precursor composites and their application in antioxidant capacity assay.

    PubMed

    Ma, Xiaoyuan; Qian, Weiping

    2010-11-15

    In the present work, the gold nanoshells (GNSs) precursor composites were preadsorbed onto the surface of ITO substrates. With the treatment of modified electrodes immersed in the gold nanoparticles (GNPs) growth solution containing different phenolic acids, the GNSs precursor composites were enlarged to varying degrees. Phenolic acids with one or more phenolic hydroxyl groups served as reductants for the growth of GNPs. The enlargement conditions varied with the different reducing capacity of phenolic acids, exhibiting specific morphologies differ from the complete GNSs. Consequently, the UV-vis-NIR spectra and cyclic voltammetry curves for the phenolic acid-treated ITO electrode were gradually changed. Results showed that the higher reducing capacity for phenolic acid to reduce AuCl(4)(-) to Au(0) resulted in the intensified localized surface plasmon resonance features and reduced cathodic currents. The spectral wavelength peaks red shifted hundreds of nanometers across the visible region. Moreover, the antioxidant capacity of phenolic acids correlates well with their reducing activity, both of which reflect their tendency to donate electrons. Thus, the optical and electrochemical results could be used to evaluate the antioxidant capacity of phenolic acids by utilizing GNSs precursor composites as nanoprobes. The method is simple, rapid and could be used in visual analysis to a certain extent.

  11. Photoproducts of carminic acid formed by a composite from Manihot dulcis waste.

    PubMed

    Antonio-Cisneros, Cynthia M; Dávila-Jiménez, Martín M; Elizalde-González, María P; García-Díaz, Esmeralda

    2015-04-15

    Carbon-TiO2 composites were obtained from carbonised Manihot dulcis waste and TiO2 using glycerol as an additive and thermally treating the composites at 800 °C. Furthermore, carbon was obtained from manihot to study the adsorption, desorption and photocatalysis of carminic acid on these materials. Carminic acid, a natural dye extracted from cochineal insects, is a pollutant produced by the food industry and handicrafts. Its photocatalysis was observed under different atmospheres, and kinetic curves were measured by both UV-Vis and HPLC for comparison, yielding interesting differences. The composite was capable of decomposing approximately 50% of the carminic acid under various conditions. The reaction was monitored by UV-Vis spectroscopy and LC-ESI-(Qq)-TOF-MS-DAD, enabling the identification of some intermediate species. The deleterious compound anthracene-9,10-dione was detected both in N2 and air atmospheres.

  12. Teaching Acid/Base Physiology in the Laboratory

    ERIC Educational Resources Information Center

    Friis, Ulla G.; Plovsing, Ronni; Hansen, Klaus; Laursen, Bent G.; Wallstedt, Birgitta

    2010-01-01

    Acid/base homeostasis is one of the most difficult subdisciplines of physiology for medical students to master. A different approach, where theory and practice are linked, might help students develop a deeper understanding of acid/base homeostasis. We therefore set out to develop a laboratory exercise in acid/base physiology that would provide…

  13. A clinical approach to acid-base conundrums.

    PubMed

    Garrubba, Carl; Truscott, Judy

    2016-04-01

    Acid-base disorders can provide essential clues to underlying patient conditions. This article provides a simple, practical approach to identifying simple acid-base disorders and their compensatory mechanisms. Using this stepwise approach, clinicians can quickly identify and appropriately treat acid-base disorders.

  14. Using Willie's Acid-Base Box for Blood Gas Analysis

    ERIC Educational Resources Information Center

    Dietz, John R.

    2011-01-01

    In this article, the author describes a method developed by Dr. William T. Lipscomb for teaching blood gas analysis of acid-base status and provides three examples using Willie's acid-base box. Willie's acid-base box is constructed using three of the parameters of standard arterial blood gas analysis: (1) pH; (2) bicarbonate; and (3) CO[subscript…

  15. Synthesis and properties of poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid)/PbS hybrid composite

    SciTech Connect

    Preda, N.; Rusen, E.; Musuc, A.; Enculescu, M.; Matei, E.; Marculescu, B.; Fruth, V.; Enculescu, I.

    2010-08-15

    The synthesis of a new hybrid composite based on PbS nanoparticles and poly(methyl methacrylate-2-acrylamido-2-methylpropane sulfonic acid) [P(MMA-AMPSA)] copolymer is reported. The chemical synthesis consists in two steps: (i) a surfactant-free emulsion copolymerization between methyl methacrylate and 2-acrylamido-2-methylpropane sulfonic acid and (ii) the generation of PbS particles in the presence of the P(MMA-AMPSA) latex, from the reaction between lead nitrate and thiourea. The composite was studied by scanning electron microscopy (SEM), X-ray diffraction, FTIR spectroscopy, thermogravimetric analysis and differential scanning calorimetry. The microstructure observed using SEM proves that the PbS nanoparticles are well dispersed in the copolymer matrix. The X-ray diffraction measurements demonstrate that the PbS nanoparticles have a cubic rock salt structure. It was also found that the inorganic semiconductor nanoparticles improve the thermal stability of the copolymer matrix.

  16. Stable carbon isotopic compositions of low-molecular-weight dicarboxylic acids, oxocarboxylic acids, α-dicarbonyls, and fatty acids: implications for atmospheric processing of organic aerosols

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Kawamura, K.; Cao, F.; Lee, M.

    2015-12-01

    Stable carbon isotopic compositions (δ13C) were measured for 23 individual organic species including 9 dicarboxylic acids, 7 oxocarboxylic acids, 1 tricarboxylic acid, 2 α-dicarbonyls and 4 fatty acids in the aerosols from Gosan background site in East Asia. δ13C of particle-phase glyoxal and methylglyoxal are significantly higher than those previously reported for isoprene and other precursors, associated with isotope fractionation during atmospheric oxidation. 13C is consistently more enriched for oxalic acid (C2), glyoxylic acid, pyruvic acid, glyoxal and methylglyoxal compared to other organic compounds identified, which can be explained by the kinetic isotope effects during aqueous-phase processing and the subsequent gas-particle partitioning after clouds or wet aerosols evaporation δ13C of C2 is positively correlated with C2 and organic carbon ratio, indicating that a photochemical production of C2 is more pronounced than its degradation process during long-range transport. The 13C results also suggest that aqueous-phase oxidation of glyoxal and methylglyoxal is major formation process of oxalic acid production via the major intermediates glyoxylic acid and pyruvic acid. This study provides evidence that organic aerosols are intensively photo-chemically aged in this region.

  17. The influence of dietary essential fatty acids on uterine C20 and C22 fatty acid composition.

    PubMed

    Howie, A; Leaver, H A; Wilson, N H; Yap, P L; Aitken, I D

    1992-06-01

    The effect of dietary fatty acids on uterine fatty acid composition was studied in rats fed control diet or semi-synthetic diet supplemented with 1.5 microliter/g/day evening primrose oil (EPO) or fish oil (FO). Diet-related changes in uterine lipid were detected within 21 days. Changes of 2- to 20-fold were detected in the uterine n-6 and n-3 essential fatty acids (EFA) and in certain saturated and monounsaturated fatty acids. The FO diet was associated with higher uterine C20 and C22 n-3, and the EPO diet, with higher uterine n-6 fatty acid. High uterine C18:2 n-6 was detected in neutral lipid (NL) of rats fed high concentrations of this fatty acid, but there was little evidence of selective incorporation or retention of C18:2 n-6 by uterine NL. The incorporation of EFA into uterine phospholipids (PL) was greater than NL EFA incorporation, and uterine PL n-3/n-6 ratios showed greater diet dependence. Tissue/diet fatty acid ratios in NL and PL also indicated preferential incorporation/synthesis of C16:1 n-9, and C16:0, and there was greater incorporation of C12:0 and C14:0 into uteri of rats fed EPO and FO. Replacement of 50-60% of arachidonate with n-3 EFA in uterine PL may inhibit n-6 EFA metabolism necessary for uterine function at parturition.

  18. Composites of manganese oxide with carbon materials as catalysts for the ozonation of oxalic acid.

    PubMed

    Orge, C A; Órfão, J J M; Pereira, M F R

    2012-04-30

    Manganese oxide and manganese oxide-carbon composites were prepared and tested as catalysts for the removal of oxalic acid by ozonation. Their performances were compared with the parent carbon material (activated carbon or carbon xerogel) used to prepare the composites. Oxalic acid degradation by carbon materials is slower than that attained with manganese oxide or manganese oxide-carbon composites. A complete degradation after 90 and 45 min of reaction was obtained for carbon materials and for the catalysts containing manganese, respectively. The ozonation in the presence of the prepared composites are supposed to occur mainly by surface reactions, following a direct oxidation mechanism by molecular ozone and/or surface oxygenated radicals.

  19. The effect of diet on the fatty acid compositions of serum, brain, brain mitochondria and myelin in the rat

    PubMed Central

    Rathbone, L.

    1965-01-01

    1. Three groups of female rats (8–12 weeks old) were maintained respectively on a linoleic acid-rich diet, a linoleic acid-poor predominantly saturated-fatty acid diet and a normal diet. Changes in the fatty acid compositions of serum, brain, brain mitochondria-rich fraction and myelin were observed. 2. Of the serum fatty acids, linoleic acid showed the greatest change in the percentage of the total acids in response to diet; the change in the proportion of oleic acid was considerable. The percentages of arachidonic acid in serum fatty acids in the groups on the linoleic acid-rich and linoleic acid-poor diets were similar, but higher than those in the normal group. 3. Changes in the proportions of linoleic acid, arachidonic acid and docosahexaenoic acid occurred in brain fatty acids that to some extent paralleled those occurring in the serum. Changes in the proportions of most other acids in the serum fatty acids were not accompanied by corresponding changes in the brain fatty acids. 4. The percentage fatty acid compositions of a mitochondria-rich fraction and myelin are given, and changes in the relative proportions of linoleic acid, arachidonic acid and possibly some docosapolyenoic acids were demonstrated to occur as a result of diet. 5. The results are discussed in relation to the possible aetiology of multiple sclerosis. PMID:5881652

  20. Oleic acid-based gemini surfactants with carboxylic acid headgroups.

    PubMed

    Sakai, Kenichi; Umemoto, Naoki; Matsuda, Wataru; Takamatsu, Yuichiro; Matsumoto, Mutsuyoshi; Sakai, Hideki; Abe, Masahiko

    2011-01-01

    Anionic gemini surfactants with carboxylic acid headgroups have been synthesized from oleic acid. The hydrocarbon chain is covalently bound to the terminal carbonyl group of oleic acid via an ester bond, and the carboxylic acid headgroups are introduced to the cis double bond of oleic acid via disuccinyl units. The surfactants exhibit pH-dependent protonation-deprotonation behavior in aqueous solutions. In alkaline solutions (pH 9 in the presence of 10 mmol dm(-3) NaCl as the background electrolyte), the surfactants can lower the surface tension as well as form molecular assemblies, even in the region of low surfactant concentrations. Under acidic (pH 3) or neutral (pH 6-7) conditions, the surfactants are intrinsically insoluble in aqueous media and form a monolayer at the air/water interface. In this study, we have investigated physicochemical properties such as the function of the hydrocarbon chain length by means of static surface tension, pyrene fluorescence, dynamic light scattering, surface pressure-area isotherms, and infrared external reflection measurements.

  1. Identification of Secretory Proteins in Mycobacterium tuberculosis Using Pseudo Amino Acid Composition

    PubMed Central

    Yang, Huan; Tang, Hua; Chen, Xin-Xin; Zhang, Chang-Jian; Zhu, Pan-Pan; Ding, Hui

    2016-01-01

    Tuberculosis is killing millions of lives every year and on the blacklist of the most appalling public health problems. Recent findings suggest that secretory protein of Mycobacterium tuberculosis may serve the purpose of developing specific vaccines and drugs due to their antigenicity. Responding to global infectious disease, we focused on the identification of secretory proteins in Mycobacterium tuberculosis. A novel method called MycoSec was designed by incorporating g-gap dipeptide compositions into pseudo amino acid composition. Analysis of variance-based technique was applied in the process of feature selection and a total of 374 optimal features were obtained and used for constructing the final predicting model. In the jackknife test, MycoSec yielded a good performance with the area under the receiver operating characteristic curve of 0.93, demonstrating that the proposed system is powerful and robust. For user's convenience, the web server MycoSec was established and an obliging manual on how to use it was provided for getting around any trouble unnecessary. PMID:27597968

  2. High performance bio-based thermosets for composites and coatings

    NASA Astrophysics Data System (ADS)

    Paramarta, Adlina Ambeg

    In the recent decade, there has been increasing interest in using renewable feedstocks as chemical commodities for composites and coatings application. Vegetable oils are promising renewable resources due to their wide availability with affordable cost. In fact, the utilization of vegetable oils to produce composite and coatings products has been around for centuries; linseed oil was widely used for wide variety of paints. However, due to its chemical structure, the application of vegetable oils for high-performance materials is limited; and thus chemical modification is necessary. One of the modification approaches is by substituting the glycerol core in the triglycerides with sucrose to form sucrose esters of vegetable oil fatty acids, in which this resin possesses a higher number of functional group per molecule and a more rigid core. In this research, thermosets of highly functionalized sucrose esters of vegetable oils were developed. Two crosslinking methods of epoxidized surcrose soyate (ESS) resins were explored: direct polymerization with anhydride moieties for composite applications and Michael-addition reaction of acrylated-epoxidized sucrose soyate (AESS) for coatings applications. In the first project, it was shown that the reaction kinetics, thermal and mechanical properties of the materials can be tuned by varying the molar ratio between the epoxide and anhydride, plus the type and amount of catalyst. Furthermore, the toughness properties of the ESS-based thermosets can be improved by changing the type of anhydride crosslinkers and incorporating secondary phase rubbers. Then, in the second system, the epoxy functionality in the ESS was converted into acrylate group, which then crosslinked with amine groups through the Michael-addition reaction to produce coatings systems. The high number of functional groups and the fast reactivity of the crosslinker results in coatings that can be cured at ambient temperature, yet still possess moderately high glass

  3. Conductive composites based on exfoliated graphite

    SciTech Connect

    Afanasov, I.M.; Morozov, V.A.; Seleznev, A.N.; Avdeev, V.V.

    2008-06-15

    Conductive composites of exfoliated graphite (EG) and coal-tar pitch have been prepared by mixing the components. The electrical properties of the composites have been studied, and the results have been interpreted in terms of the percolation theory. The threshold EG content for electrical conduction is determined to be similar or equal to 1.5 wt %, independent of the properties of the pitch and EG.

  4. Pitch-based carbon foam and composites

    DOEpatents

    Klett, James W.

    2002-01-01

    A process for producing carbon foam or a composite is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications.

  5. Pitch-based carbon foam and composites

    DOEpatents

    Klett, James W.

    2003-12-02

    A process for producing carbon foam or a composite is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications.

  6. Pitch-based carbon foam and composites

    DOEpatents

    Klett, James W.

    2001-01-01

    A process for producing carbon foam or a composite is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications.

  7. Pitch-based carbon foam and composites

    DOEpatents

    Klett, James W.

    2003-12-16

    A process for producing carbon foam or a composite is disclosed which obviates the need for conventional oxidative stabilization. The process employs mesophase or isotropic pitch and a simplified process using a single mold. The foam has a relatively uniform distribution of pore sizes and a highly aligned graphic structure in the struts. The foam material can be made into a composite which is useful in high temperature sandwich panels for both thermal and structural applications.

  8. Macro-Fiber Composite Based Transduction

    DTIC Science & Technology

    2016-03-01

    Canada); Julliere, B. Source: Smart Materials and Structures, v 16, n 6, p 2315-2322, December 1,2007 Active Shape control - [0/903]T composite...August 1, 2014 Control of a space rigidizable inflatable boom using macro-fiber composite actuators Tarazaga, Pablo A. (Center for Intelligent Material ...Structural Dynamics and Controls Lab., Pennsylvania State University, 157E Hammond Building , University Park, PA 16802, United States); Wang, K.W

  9. Method and compositions for reducing corrosion in the removal of acidic gases from gaseous mixtures

    SciTech Connect

    DuPart, M.S.; Cringle, D.C.; Oakes, B.D.

    1984-05-01

    A corrosion inhibited composition containing a gas conditioning solution such as an alkanol amine with water or with organic solvents and with small amounts of soluble thiocyanate compounds, soluble trivalent bismuth compounds with or without soluble divalent nickel or cobalt compounds. The compositions are useful to separate acid gases such as carbon dioxide from hydrocarbon feed streams in gas conditioning apparatus with minimum amounts of corrosion of the ferrous surfaces.

  10. Influence of Fatty Acid Precursors, Including Food Preservatives, on the Growth and Fatty Acid Composition of Listeria monocytogenes at 37 and 10°C ▿

    PubMed Central

    Julotok, Mudcharee; Singh, Atul K.; Gatto, Craig; Wilkinson, Brian J.

    2010-01-01

    Listeria monocytogenes is a food-borne pathogen that grows at refrigeration temperatures and increases its content of anteiso-C15:0 fatty acid, which is believed to be a homeoviscous adaptation to ensure membrane fluidity, at these temperatures. As a possible novel approach for control of the growth of the organism, the influences of various fatty acid precursors, including branched-chain amino acids and branched- and straight-chain carboxylic acids, some of which are also well-established food preservatives, on the growth and fatty acid composition of the organism at 37°C and 10°C were studied in order to investigate whether the organism could be made to synthesize fatty acids that would result in impaired growth at low temperatures. The results indicate that the fatty acid composition of L. monocytogenes could be modulated by the feeding of branched-chain amino acid, C4, C5, and C6 branched-chain carboxylic acid, and C3 and C4 straight-chain carboxylic acid fatty acid precursors, but the growth-inhibitory effects of several preservatives were independent of effects on fatty acid composition, which were minor in the case of preservatives metabolized via acetyl coenzyme A. The ability of a precursor to modify fatty acid composition was probably a reflection of the substrate specificities of the first enzyme, FabH, in the condensation of primers of fatty acid biosynthesis with malonyl acyl carrier protein. PMID:20048057

  11. Influencing fatty acid composition of yeasts by lanthanides.

    PubMed

    Kolouchova, Irena; Sigler, Karel; Zimola, Michal; Rezanka, Tomas; Matatkova, Olga; Masak, Jan

    2016-08-01

    The growth of microorganisms is affected by cultivation conditions, concentration of carbon and nitrogen sources and the presence of trace elements. One of the new possibilities of influencing the production of cell mass or lipids is the use of lanthanides. Lanthanides are biologically non-essential elements with wide applications in technology and industry and their concentration as environmental contaminants is therefore increasing. Although non-essential, lanthanides have been proposed (and even used) to produce beneficial effects in plants but their mechanisms of action are unclear. Recently, it was suggested that they may replace essential elements or operate as potent blockers of Ca(2+) channels. We tested the effect of low concentrations of lanthanides on traditional biotechnologically useful yeast species (Kluyveromyces polysporus, Saccharomyces cerevisiae, Torulospora delbrueckii), and species capable of high accumulation of lipids (Rhodotorula glutinis, Trichosporon cutaneum, Candida sp., Yarrowia lipolytica). Low concentrations of lanthanum and monazite were conducive to an increase in cell mass and lipids and also higher production of palmitoleic acid, commonly used in cosmetics and medicine, and ω6-linoleic acid which is a precursor of thromboxanes, prostaglandins and leucotrienes.

  12. The folding type of a protein is relevant to the amino acid composition.

    PubMed

    Nakashima, H; Nishikawa, K; Ooi, T

    1986-01-01

    The folding types of 135 proteins, the three-dimensional structures of which are known, were analyzed in terms of the amino acid composition. The amino acid composition of a protein was expressed as a point in a multidimensional space spanned with 20 axes, on which the corresponding contents of 20 amino acids in the protein were represented. The distribution pattern of proteins in this composition space was examined in relation to five folding types, alpha, beta, alpha/beta, alpha + beta, and irregular type. The results show that amino acid compositions of the alpha, beta, and alpha/beta types are located in different regions in the composition space, thus allowing distinct separation of proteins depending on the folding types. The points representing proteins of the alpha + beta and irregular types, however, are widely scattered in the space, and the existing regions overlap with those of the other folding types. A simple method of utilizing the "distance" in the space was found to be convenient for classification of proteins into the five folding types. The assignment of the folding type with this method gave an accuracy of 70% in the coincidence with the experimental data.

  13. Determination of fatty acid composition of γ-irradiated hazelnuts, walnuts, almonds, and pistachios

    NASA Astrophysics Data System (ADS)

    Gecgel, Umit; Gumus, Tuncay; Tasan, Murat; Daglioglu, Orhan; Arici, Muhammet

    2011-04-01

    Hazelnut, walnut, almonds, and pistachio nuts were treated with 1, 3, 5, and 7 kGy of gamma irradiation, respectively. Oil content, free fatty acid, peroxide value, and fatty acid composition of the nuts were investigated immediately after irradiation. The data obtained from the experiments indicated that gamma irradiation did not cause any significant change in the oil content of nuts. In contrast, free fatty acid and peroxide value of the nuts increased proportionally to the dose (p<0.05). Among the fatty acids determined, the concentration of total saturated fatty acids increased while total monounsaturated and total polyunsaturated fatty acids decreased with the irradiation dose (p<0.05 and <0.01).

  14. Stable nitrogen isotopic composition of amino acids reveals food web structure in stream ecosystems.

    PubMed

    Ishikawa, Naoto F; Kato, Yoshikazu; Togashi, Hiroyuki; Yoshimura, Mayumi; Yoshimizu, Chikage; Okuda, Noboru; Tayasu, Ichiro

    2014-07-01

    The stable N isotopic composition of individual amino acids (SIAA) has recently been used to estimate trophic positions (TPs) of animals in several simple food chain systems. However, it is unknown whether the SIAA is applicable to more complex food web analysis. In this study we measured the SIAA of stream macroinvertebrates, fishes, and their potential food sources (periphyton and leaf litter of terrestrial C3 plants) collected from upper and lower sites in two streams having contrasting riparian landscapes. The stable N isotope ratios of glutamic acid and phenylalanine confirmed that for primary producers (periphyton and C3 litter) the TP was 1, and for primary consumers (e.g., mayfly and caddisfly larvae) it was 2. We built a two-source mixing model to estimate the relative contributions of aquatic and terrestrial sources to secondary and higher consumers (e.g., stonefly larva and fishes) prior to the TP calculation. The estimated TPs (2.3-3.5) roughly corresponded to their omnivorous and carnivorous feeding habits, respectively. We found that the SIAA method offers substantial advantages over traditional bulk method for food web analysis because it defines the food web structure based on the metabolic pathway of amino groups, and can be used to estimate food web structure under conditions where the bulk method cannot be used. Our result provides evidence that the SIAA method is applicable to the analysis of complex food webs, where heterogeneous resources are mixed.

  15. Amino acid composition of some Amaranthus sp. grain proteins and of its fractions.

    PubMed

    Correa, A D; Jokl, L; Carlsson, R

    1986-09-01

    This study was carried out to determine the protein content of several Amaranthus sp. grains. Findings revealed this has a high lysine (5.3 to 6.3 of the protein) and sulphur amino acids content (3.4-4.0%), while leucine could well be limiting when those seeds are used as a sole protein source in food. Using the correction for in vitro protein digestibility, the chemical score varied from 50 to 67. The calculated protein efficiency ratios and biological values ranged from 1.39 to 1.80 and 53 to 68, respectively. Considering that amaranth grain is a good supplement to cereal grain, the protein of A. hypochondriacus HH5 (yellow seeds) and A. anclancalius (black seeds) was fractionated into albumin, globulin, prolamin and glutelin. The average proportions between those soluble proteins were 65:17:11:7, respectively. Albumin had the highest lysine content (7.3-8.2%), and globulin the highest methionine (4.1-5.3%) and phenylalanine (6.0-6.1%) content. Prolamin had the highest threonine (4.6-5.4%) and leucine (6.8-6.9%) content, while glutelin had a very low methionine content (0.6-1.0%). Based on the above-mentioned findings, the authors conclude the variation in the amino acid composition of the protein fractions can be used for genetic protein improvement.

  16. Compressive fatigue properties of an acidic calcium phosphate cement-effect of phase composition.

    PubMed

    Ajaxon, Ingrid; Öhman Mägi, Caroline; Persson, Cecilia

    2017-03-01

    Calcium phosphate cements (CPCs) are synthetic bone grafting materials that can be used in fracture stabilization and to fill bone voids after, e.g., bone tumour excision. Currently there are several calcium phosphate-based formulations available, but their use is partly limited by a lack of knowledge of their mechanical properties, in particular their resistance to mechanical loading over longer periods of time. Furthermore, depending on, e.g., setting conditions, the end product of acidic CPCs may be mainly brushite or monetite, which have been found to behave differently under quasi-static loading. The objectives of this study were to evaluate the compressive fatigue properties of acidic CPCs, as well as the effect of phase composition on these properties. Hence, brushite cements stored for different lengths of time and with different amounts of monetite were investigated under quasi-static and dynamic compression. Both storage and brushite-to-monetite phase transformation was found to have a pronounced effect both on quasi-static compressive strength and fatigue performance of the cements, whereby a substantial phase transformation gave rise to a lower mechanical resistance. The brushite cements investigated in this study had the potential to survive 5 million cycles at a maximum compressive stress of 13 MPa. Given the limited amount of published data on fatigue properties of CPCs, this study provides an important insight into the compressive fatigue behaviour of such materials.

  17. Effect of acidic solutions on the surface degradation of a micro-hybrid composite resin.

    PubMed

    Münchow, Eliseu A; Ferreira, Ana Cláudia A; Machado, Raissa M M; Ramos, Tatiana S; Rodrigues-Junior, Sinval A; Zanchi, Cesar H

    2014-01-01

    Composite resins may undergo wear by the action of chemical substances (e.g., saliva, alcohol, bacterial acids) of the oral environment, which may affect the material's structure and surface properties. This study evaluated the effect of acidic substances on the surface properties of a micro-hybrid composite resin (Filtek Z-250). Eighty specimens were prepared, and baseline hardness and surface roughness (KMN0 and Ra0, respectively) were measured. The specimens were subjected to sorption (SO) and solubility (SL) tests according to ISO 4049:2009, but using different storage solutions: deionized water; 75/25 vol% ethanol/water solution; lactic acid; propionic acid; and acetic acid. The acids were used in two concentrations: PA and 0.02 N. pH was measured for all solutions and final hardness (KMN1) and surface roughness (Ra1) were measured. Data were analyzed with paired t-tests and one-way ANOVA and Tukey's test (a=5%). All solutions decreased hardness and increased the Ra values, except for the specimens stored in water and 0.02 N lactic acid, which maintained the hardness. All solutions produced similar SO and SL phenomena, except for the 0.02 N lactic acid, which caused lower solubility than the other solutions. Ethanol showed the highest pH (6.6) and the 0.02 N lactic acid the lowest one (2.5). The solutions affected negatively the surface properties of the composite resin; in addition, an acidic pH did not seem to be a significant factor that intensifies the surface degradation phenomena.

  18. Evolution of proteomes: fundamental signatures and global trends in amino acid compositions

    PubMed Central

    Tekaia, Fredj; Yeramian, Edouard

    2006-01-01

    Background The evolutionary characterization of species and lifestyles at global levels is nowadays a subject of considerable interest, particularly with the availability of many complete genomes. Are there specific properties associated with lifestyles and phylogenies? What are the underlying evolutionary trends? One of the simplest analyses to address such questions concerns characterization of proteomes at the amino acids composition level. Results In this work, amino acid compositions of a large set of 208 proteomes, with significant number of representatives from the three phylogenetic domains and different lifestyles are analyzed, resorting to an appropriate multidimensional method: Correspondence analysis. The analysis reveals striking discrimination between eukaryotes, prokaryotic mesophiles and hyperthemophiles-themophiles, following amino acid usage. In sharp contrast, no similar discrimination is observed for psychrophiles. The observed distributional properties are compared with various inferred chronologies for the recruitment of amino acids into the genetic code. Such comparisons reveal correlations between the observed segregations of species following amino acid usage, and the separation of amino acids following early or late recruitment. Conclusion A simple description of proteomes according to amino acid compositions reveals striking signatures, with sharp segregations or on the contrary non-discriminations following phylogenies and lifestyles. The distribution of species, following amino acid usage, exhibits a discrimination between [high GC]-[high optimal growth temperatures] and [low GC]-[moderate temperatures] characteristics. This discrimination appears to coincide closely with the separation of amino acids following their inferred early or late recruitment into the genetic code. Taken together the various results provide a consistent picture for the evolution of proteomes, in terms of amino acid usage. PMID:17147802

  19. Decreased hepatotoxic bile acid composition and altered synthesis in progressive human nonalcoholic fatty liver disease

    SciTech Connect

    Lake, April D.; Novak, Petr; Shipkova, Petia; Aranibar, Nelly; Robertson, Donald; Reily, Michael D.; Lu, Zhenqiang; Lehman-McKeeman, Lois D.; Cherrington, Nathan J.

    2013-04-15

    Bile acids (BAs) have many physiological roles and exhibit both toxic and protective influences within the liver. Alterations in the BA profile may be the result of disease induced liver injury. Nonalcoholic fatty liver disease (NAFLD) is a prevalent form of chronic liver disease characterized by the pathophysiological progression from simple steatosis to nonalcoholic steatohepatitis (NASH). The hypothesis of this study is that the ‘classical’ (neutral) and ‘alternative’ (acidic) BA synthesis pathways are altered together with hepatic BA composition during progression of human NAFLD. This study employed the use of transcriptomic and metabolomic assays to study the hepatic toxicologic BA profile in progressive human NAFLD. Individual human liver samples diagnosed as normal, steatosis, and NASH were utilized in the assays. The transcriptomic analysis of 70 BA genes revealed an enrichment of downregulated BA metabolism and transcription factor/receptor genes in livers diagnosed as NASH. Increased mRNA expression of BAAT and CYP7B1 was observed in contrast to decreased CYP8B1 expression in NASH samples. The BA metabolomic profile of NASH livers exhibited an increase in taurine together with elevated levels of conjugated BA species, taurocholic acid (TCA) and taurodeoxycholic acid (TDCA). Conversely, cholic acid (CA) and glycodeoxycholic acid (GDCA) were decreased in NASH liver. These findings reveal a potential shift toward the alternative pathway of BA synthesis during NASH, mediated by increased mRNA and protein expression of CYP7B1. Overall, the transcriptomic changes of BA synthesis pathway enzymes together with altered hepatic BA composition signify an attempt by the liver to reduce hepatotoxicity during disease progression to NASH. - Highlights: ► Altered hepatic bile acid composition is observed in progressive NAFLD. ► Bile acid synthesis enzymes are transcriptionally altered in NASH livers. ► Increased levels of taurine and conjugated bile acids

  20. Stable carbon isotopic compositions of organic acids in total suspended particles and dusts from Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Ma, Shexia; Peng, Ping'an; Song, Jianzhong; Zhao, Jinping; He, Lulu; Sheng, Guoying; Fu, Jiamo

    2010-10-01

    Stable carbon isotopic compositions of individual organic acids were determined in total suspended particles and dusts from Guangzhou. The δ 13C values of high molecular weight n-alkanoic acids (C 20-C 28) varied from -34.1‰ to -32.4‰ and tended to be heavier in summer and lighter in winter. These δ 13C values indicate that high molecular weight n-alkanoic acids were derived mainly from emission by C 3 plants. Reduced biological synthesis of high molecular weight n-alkanoic acids in winter may be the reason for the light carbon isotopic composition. The δ 13C values of low molecular weight n-alkanoic acids (C 10-C 18) changed from -31.7‰ to -30.3‰ and exhibited a reverse seasonal trend, i.e., heavier in winter and lighter in summer. Slightly heavier δ 13C values of low molecular weight n-alkanoic acids than those of high molecular weight n-alkanoic acids suggested that they may be emitted from blended sources, e.g., anthropogenic sources and vegetation waxes. Lighter δ 13C values in summer may be attributed to relatively low anthropogenic sources and high botanic sources in summer. Dicarboxylic acids and aromatic acids have been proposed as secondary products from photochemical degradation. The average δ 13C values of dicarboxylic acids and aromatic acids were heavier, and ranged from -25.2‰ to -22.9‰ and from -30.0‰ to -27.6‰, respectively. Both dicarboxylic acids and aromatic acids displayed the same temporal variations in the δ 13C values, i.e., negative δ 13C in the summer samples and positive in the winter samples, which may be controlled by photochemical reactions; they are generally severe in winter in Guangzhou under the monsoon weather system. The heaviest δ 13C values were observed in dicarboxylic acids, indicating that dicarboxylic acids were formed by fast and more complete oxidation reactions. These results indicate that the stable carbon isotopic composition of organic acids may provide important information about sources and

  1. Effect of vitamin E on milk composition of grazing dairy cows supplemented with microencapsulated conjugated linoleic acid.

    PubMed

    Ramírez-Mella, Monica; Hernández-Mendo, Omar; Ramírez-Bribiesca, Efren Jacinto; Améndola-Massiotti, Ricardo Daniel; Crosby-Galván, María M; Burgueño-Ferreira, Juan A

    2013-11-01

    The objective of this study was to evaluate the effect of vitamin E on the fat content and fatty acid profile of grazing dairy cows supplemented with microencapsulated conjugated linoleic acid. Eight New Zealand Holstein cows in a rotational grazing system were used, in a crossover design, randomly assigned to four treatments: control (base diet with microencapsulated conjugated linoleic acid) and three levels of vitamin E (control with 4,000; 8,000; and 12,000 IU/cow per day). All the cows received a supplement apportioning 5 g of cis-9, trans-11, and 5 g of trans-10, cis-12 of conjugated linoleic acid. Moreover, they each received 4-kg dry matter (DM) concentrate and 3.2-kg DM corn silage every day. There were no differences in dry matter intake, milk production, milk composition (fat, protein, and lactose), or fatty acid profile as an effect of vitamin E, and fat content remained under 3 % in all treatments. Therefore, under the conditions that this experiment was carried out, high concentrations of vitamin E in the diet of grazing dairy cows do not inhibit milk fat depression associated with conjugated linoleic acid. It also has no effect on the fatty acid profile of the milk.

  2. Amino acid composition, including key derivatives of eccrine sweat: potential biomarkers of certain atopic skin conditions.

    PubMed

    Mark, Harker; Harding, Clive R

    2013-04-01

    The free amino acid (AA) composition of eccrine sweat is different from other biological fluids, for reasons which are not properly understood. We undertook the detailed analysis of the AA composition of freshly isolated pure human eccrine sweat, including some of the key derivatives of AA metabolism, to better understand the key biological mechanisms governing its composition. Eccrine sweat was collected from the axillae of 12 healthy subjects immediately upon formation. Free AA analysis was performed using an automatic AA analyser after ninhydrin derivatization. Pyrrolidine-5-carboxylic acid (PCA) and urocanic acid (UCA) levels were determined using GC/MS. The free AA composition of sweat was dominated by the presence of serine accounting for just over one-fifth of the total free AA composition. Glycine was the next most abundant followed by PCA, alanine, citrulline and threonine, respectively. The data obtained indicate that the AA content of sweat bears a remarkable similarity to the AA composition of the epidermal protein profilaggrin. This protein is the key source of free AAs and their derivatives that form a major part of the natural moisturizing factor (NMF) within the stratum corneum (SC) and plays a major role in maintaining the barrier integrity of human skin. As perturbations in the production of NMF can lead to abnormal barrier function and can arise as a consequence of filaggrin genotype, we propose the quantification of AAs in sweat may serve as a non-invasive diagnostic biomarker for certain atopic skin conditions, that is, atopic dermatitis (AD).

  3. The acid-base resistant zone in three dentin bonding systems.

    PubMed

    Inoue, Go; Nikaido, Toru; Foxton, Richard M; Tagami, Junji

    2009-11-01

    An acid-base resistant zone has been found to exist after acid-base challenge adjacent to the hybrid layer using SEM. The aim of this study was to examine the acid-base resistant zone using three different bonding systems. Dentin disks were applied with three different bonding systems, and then a resin composite was light-cured to make dentin disk sandwiches. After acid-base challenge, the polished surfaces were observed using SEM. For both one- and two-step self-etching primer systems, an acid-base resistant zone was clearly observed adjacent to the hybrid layer - but with differing appearances. For the wet bonding system, the presence of an acid-base resistant zone was unclear. This was because the self-etching primer systems etched the dentin surface mildly, such that the remaining mineral phase of dentin and the bonding agent yielded clear acid-base resistant zones. In conclusion, the acid-base resistant zone was clearly observed when self-etching primer systems were used, but not so for the wet bonding system.

  4. Are carboxyl groups the most acidic sites in amino acids? Gas-phase acidities, photoelectron spectra, and computations on tyrosine, p-hydroxybenzoic acid, and their conjugate bases.

    PubMed

    Tian, Zhixin; Wang, Xue-Bin; Wang, Lai-Sheng; Kass, Steven R

    2009-01-28

    Deprotonation of tyrosine in the gas phase was found to occur preferentially at the phenolic site, and the conjugate base consists of a 70:30 mixture of phenoxide and carboxylate anions at equilibrium. This result was established by developing a chemical probe for differentiating these two isomers, and the presence of both ions was confirmed by photoelectron spectroscopy. Equilibrium acidity measurements on tyrosine indicated that deltaG(acid)(o) = 332.5 +/- 1.5 kcal mol(-1) and deltaH(acid)(o) = 340.7 +/- 1.5 kcal mol(-1). Photoelectron spectra yielded adiabatic electron detachment energies of 2.70 +/- 0.05 and 3.55 +/- 0.10 eV for the phenoxide and carboxylate anions, respectively. The H/D exchange behavior of deprotonated tyrosine was examined using three different alcohols (CF3CH2OD, C6H5CH2OD, and CH3CH2OD), and incorporation of up to three deuterium atoms was observed. Two pathways are proposed to account for these results, and all of the experimental findings are supplemented with B3LYP/aug-cc-pVDZ and G3B3 calculations. In addition, it was found that electrospray ionization of tyrosine from a 3:1 (v/v) CH3OH/H2O solution using a commercial source produces a deprotonated [M-H]- anion with the gas-phase equilibrium composition rather than the structure of the ion that exists in aqueous media. Electrospray ionization from acetonitrile, however, leads largely to the liquid-phase (carboxylate) structure. A control molecule, p-hydroxybenzoic acid, was found to behave in a similar manner. Thus, the electrospray conditions that are employed for the analysis of a compound can alter the isomeric composition of the resulting anion.

  5. Effects of simulated acid rain on soil fauna community composition and their ecological niches.

    PubMed

    Wei, Hui; Liu, Wen; Zhang, Jiaen; Qin, Zhong

    2017-01-01

    Acid rain is one of the severest environmental issues globally. Relative to other global changes (e.g., warming, elevated atmospheric [CO2], and nitrogen deposition), however, acid rain has received less attention than its due. Soil fauna play important roles in multiple ecological processes, but how soil fauna community responds to acid rain remains less studied. This microcosm experiment was conducted using latosol with simulated acid rain (SAR) manipulations to observe potential changes in soil fauna community under acid rain stress. Four pH levels, i.e., pH 2.5, 3.5, 4.5, and 5.5, and a neutral control of pH 7.0 were set according to the current pH condition and acidification trend of precipitation in southern China. As expected, we observed that the SAR treatments induced changes in soil fauna community composition and their ecological niches in the tested soil; the treatment effects tended to increase as acidity increased. This could be attributable to the environmental stresses (such as acidity, porosity and oxygen supply) induced by the SAR treatments. In addition to direct acidity effect, we propose that potential changes in permeability and movability of water and oxygen in soils induced by acid rain could also give rise to the observed shifts in soil fauna community composition. These are most likely indirect pathways of acid rain to affect belowground community. Moreover, we found that nematodes, the dominating soil fauna group in this study, moved downwards to mitigate the stress of acid rain. This is probably detrimental to soil fauna in the long term, due to the relatively severer soil conditions in the deep than surface soil layer. Our results suggest that acid rain could change soil fauna community and the vertical distribution of soil fauna groups, consequently changing the underground ecosystem functions such as organic matter decomposition and greenhouse gas emissions.

  6. Tables of critical values for examining compositional non-randomness in proteins and nucleic acids

    NASA Technical Reports Server (NTRS)

    Laird, M.; Holmquist, R.

    1975-01-01

    A binomially distributed statistic is defined to show whether or not the proportion of a particular amino acid in a protein deviates from random expectation. An analogous statistic is derived for nucleotides in nucleic acids. These new statistics are simply related to the classical chi-squared test. They explicitly account for the compositional fluctuations imposed by the finite length of proteins, and they are more accurate than previous tables.

  7. Composite particles formed by complexation of poly(methacrylic acid) - stabilized magnetic fluid with chitosan: Magnetic material for bioapplications.

    PubMed

    Safarik, Ivo; Stepanek, Miroslav; Uchman, Mariusz; Slouf, Miroslav; Baldikova, Eva; Nydlova, Leona; Pospiskova, Kristyna; Safarikova, Mirka

    2016-10-01

    A simple procedure for the synthesis of magnetic fluid (ferrofluid) stabilized by poly(methacrylic acid) has been developed. This ferrofluid was used to prepare a novel type of magnetically responsive chitosan-based composite material. Both ferrofluid and magnetic chitosan composite were characterized by a combination of microscopy (optical microscopy, TEM, SEM), scattering (static and dynamic light scattering, SANS) and spectroscopy (FTIR) techniques. Magnetic chitosan was found to be a perspective material for various bioapplications, especially as a magnetic carrier for immobilization of enzymes and cells. Lipase from Candida rugosa was covalently attached after cross-linking and activation of chitosan using glutaraldehyde. Baker's yeast cells (Saccharomyces cerevisiae) were incorporated into the chitosan composite during its preparation; both biocatalysts were active after reaction with appropriate substrates.

  8. Identifying a base in a nucleic acid

    DOEpatents

    Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua

    2005-02-08

    Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.

  9. Fatty acid composition of umbilical arteries and veins: possible implications for the fetal EFA-status.

    PubMed

    Hornstra, G; van Houwelingen, A C; Simonis, M; Gerrard, J M

    1989-06-01

    Fatty acid compositions were determined of phospholipids, isolated from umbilical arteries and veins, obtained from Dutch neonates after vaginal delivery, terminating normal pregnancy. The fatty acid profiles of the cord vessels were characterized by the absence of eicosapentaenoic (timnodonic) acid, a low (2-3%) content of linoleic acid and reasonable amounts of arachidonic acid (10-15%) and docosahexaenoic (cervonic) acid (3-5%). Significant amounts of Mead acid (1-4%) and its direct elongation product (0.5-2%) were also observed. In each cord, the efferent blood vessels contained significantly more Mead acid and other fatty acids of the oleic acid (n-9) family and less fatty acids of the linoleic (n-6) and linolenic (n-3) families than the afferent blood vessel. This indicates that the essential fatty acid (EFA) status of 'downstream' neonatal tissue may be marginal. No signs of EFA-deficiency were observed in endothelial and smooth muscle cells in culture, or in blood vessels from adults. In all cords 22:5(n-6) was significantly higher in the artery compared to the vein, whereas for all other (n-6) fatty acids this difference was negative. Since the synthesis of 22:5(n-6) is known to be stimulated when the required amount of cervonic acid, 22:6(n-3), is too low, our observations also suggest that the cervonic acid status of the neonates investigated was not optimal. Further studies are in progress to relate these findings to maternal EFA status and complications of pregnancy.

  10. Effect of the fatty acid composition of acclimated oenological Lactobacillus plantarum on the resistance to ethanol.

    PubMed

    Bravo-Ferrada, B M; Gómez-Zavaglia, A; Semorile, L; Tymczyszyn, E E

    2015-02-01

    The aim of this work was to evaluate the changes due to acclimation to ethanol on the fatty acid composition of three oenological Lactobacillus plantarum strains and their effect on the resistance to ethanol and malic acid consumption (MAC). Lactobacillus plantarum UNQLp 133, UNQLp 65.3 and UNQLp 155 were acclimated in the presence of 6 or 10% v/v ethanol, for 48 h at 28°C. Lipids were extracted to obtain fatty acid methyl esters and analysed by gas chromatography interfaced with mass spectroscopy. The influence of change in fatty acid composition on the viability and MAC in synthetic wine was analysed by determining the Pearson correlation coefficient. Acclimated strains showed a significant change in the fatty composition with regard to the nonacclimated strains. Adaptation to ethanol led to a decrease in the unsaturated/saturated ratio, mainly resulting from an increase in the contribution of short-length fatty acid C12:0 and a decrease of C18:1. The content of C12:0 was related to a higher viability after inoculation of synthetic wine. The MAC increased at higher contents in saturated fatty acid, but its efficiency was strain dependent.

  11. Life-history evolution at the molecular level: adaptive amino acid composition of avian vitellogenins

    PubMed Central

    Hughes, Austin L.

    2015-01-01

    Avian genomes typically encode three distinct vitellogenin (VTG) egg yolk proteins (VTG1, VTG2 and VTG3), which arose by gene duplication prior to the most recent common ancestor of birds. Analysis of VTG sequences from 34 avian species in a phylogenetic framework supported the hypothesis that VTG amino acid composition has co-evolved with embryo incubation time. Embryo incubation time was positively correlated with the proportions of dietary essential amino acids (EAAs) in VTG1 and VTG2, and with the proportion of sulfur-containing amino acids in VTG3. These patterns were seen even when only semi-altricial and/or altricial species were considered, suggesting that the duration of embryo incubation is a major selective factor on the amino acid composition of VTGs, rather than developmental mode alone. The results are consistent with the hypothesis that the level of EAAs provided to the egg represents an adaptation to the loss of amino acids through breakdown over the course of incubation and imply that life-history phenotypes and VTG amino acid composition have co-evolved throughout the evolutionary history of birds. PMID:26224713

  12. High performance graphene oxide based rubber composites.

    PubMed

    Mao, Yingyan; Wen, Shipeng; Chen, Yulong; Zhang, Fazhong; Panine, Pierre; Chan, Tung W; Zhang, Liqun; Liang, Yongri; Liu, Li

    2013-01-01

    In this paper, graphene oxide/styrene-butadiene rubber (GO/SBR) composites with complete exfoliation of GO sheets were prepared by aqueous-phase mixing of GO colloid with SBR latex and a small loading of butadiene-styrene-vinyl-pyridine rubber (VPR) latex, followed by their co-coagulation. During co-coagulation, VPR not only plays a key role in the prevention of aggregation of GO sheets but also acts as an interface-bridge between GO and SBR. The results demonstrated that the mechanical properties of the GO/SBR composite with 2.0 vol.% GO is comparable with those of the SBR composite reinforced with 13.1 vol.% of carbon black (CB), with a low mass density and a good gas barrier ability to boot. The present work also showed that GO-silica/SBR composite exhibited outstanding wear resistance and low-rolling resistance which make GO-silica/SBR very competitive for the green tire application, opening up enormous opportunities to prepare high performance rubber composites for future engineering applications.

  13. High Performance Graphene Oxide Based Rubber Composites

    NASA Astrophysics Data System (ADS)

    Mao, Yingyan; Wen, Shipeng; Chen, Yulong; Zhang, Fazhong; Panine, Pierre; Chan, Tung W.; Zhang, Liqun; Liang, Yongri; Liu, Li

    2013-08-01

    In this paper, graphene oxide/styrene-butadiene rubber (GO/SBR) composites with complete exfoliation of GO sheets were prepared by aqueous-phase mixing of GO colloid with SBR latex and a small loading of butadiene-styrene-vinyl-pyridine rubber (VPR) latex, followed by their co-coagulation. During co-coagulation, VPR not only plays a key role in the prevention of aggregation of GO sheets but also acts as an interface-bridge between GO and SBR. The results demonstrated that the mechanical properties of the GO/SBR composite with 2.0 vol.% GO is comparable with those of the SBR composite reinforced with 13.1 vol.% of carbon black (CB), with a low mass density and a good gas barrier ability to boot. The present work also showed that GO-silica/SBR composite exhibited outstanding wear resistance and low-rolling resistance which make GO-silica/SBR very competitive for the green tire application, opening up enormous opportunities to prepare high performance rubber composites for future engineering applications.

  14. High Performance Graphene Oxide Based Rubber Composites

    PubMed Central

    Mao, Yingyan; Wen, Shipeng; Chen, Yulong; Zhang, Fazhong; Panine, Pierre; Chan, Tung W.; Zhang, Liqun; Liang, Yongri; Liu, Li

    2013-01-01

    In this paper, graphene oxide/styrene-butadiene rubber (GO/SBR) composites with complete exfoliation of GO sheets were prepared by aqueous-phase mixing of GO colloid with SBR latex and a small loading of butadiene-styrene-vinyl-pyridine rubber (VPR) latex, followed by their co-coagulation. During co-coagulation, VPR not only plays a key role in the prevention of aggregation of GO sheets but also acts as an interface-bridge between GO and SBR. The results demonstrated that the mechanical properties of the GO/SBR composite with 2.0 vol.% GO is comparable with those of the SBR composite reinforced with 13.1 vol.% of carbon black (CB), with a low mass density and a good gas barrier ability to boot. The present work also showed that GO-silica/SBR composite exhibited outstanding wear resistance and low-rolling resistance which make GO-silica/SBR very competitive for the green tire application, opening up enormous opportunities to prepare high performance rubber composites for future engineering applications. PMID:23974435

  15. Polarity based fractionation of fulvic acids.

    PubMed

    Li, Aimin; Hu, Jundong; Li, Wenhui; Zhang, Wei; Wang, Xuejun

    2009-11-01

    Fulvic acids from the soil of Peking University (PF) and a Nordic river (NF) were separated into well defined sub-fractions using sequential elution techniques based on eluent polarity. The chemical properties of the fractions including: PF1 and NF1 (eluted by 0.01 M HCl), PF2 and NF2 (eluted by 0.01 M HCl+20% methanol), PF3 and NF3 (eluted by 0.01 M HCl+40% methanol), and PF4 and NF4 (eluted by 100% methanol), were characterized using UV-Visible spectroscopy, elemental analysis and (13)C NMR. The results showed that the UV absorptions of the elution peaks at 280 nm (A280) increased from PF2 to PF4 and NF2 to NF4. No elution peaks were observed for PF1 and NF1. The carbon contents increased from 43.34% to 51.90% and 43.06% to 53.26% while the oxygen contents decreased from 46.39% to 36.76% and 49.76% to 40.03% for PF1-PF4 and NF1-NF4, respectively. As a polarity indicator, the (O+N)/C ratio for PF1-PF4 and NF1-NF4 decreased from 0.88 to 0.62 and 0.89 to 0.58, respectively. The aromatic carbon content increased from PF1 to PF4 and NF1 to NF4, suggesting an increase of the hydrophobicity of these fractions. The polarity was positively related to the ratio of UV absorption at 250 nm and 365 nm (E2/E3), and negatively related to the aromaticity. A high positive relationship between the aromaticity and E2/E3 of fulvic acid fractions was also obtained. The use of an eluent with a decreasing polarity allowed to providing simpler fractions of soil and aquatic fulvic acids.

  16. Finite element based micro-mechanics modeling of textile composites

    NASA Technical Reports Server (NTRS)

    Glaessgen, E. H.; Griffin, O. H., Jr.

    1995-01-01

    Textile composites have the advantage over laminated composites of a significantly greater damage tolerance and resistance to delamination. Currently, a disadvantage of textile composites is the inability to examine the details of the internal response of these materials under load. Traditional approaches to the study fo textile based composite materials neglect many of the geometric details that affect the performance of the material. The present three dimensional analysis, based on the representative volume element (RVE) of a plain weave, allows prediction of the internal details of displacement, strain, stress, and failure quantities. Through this analysis, the effect of geometric and material parameters on the aforementioned quantities are studied.

  17. A perspective on MoSi sub 2 based composites

    SciTech Connect

    Petrovic, J.J. ); Vasudevan, A.K. )

    1992-01-01

    MoSi{sub 2} based composites represent an important new class of high temperature structural silicides,'' with significant potential for elevated temperature structural applications in the range of 1200--1600{degrees}C in oxidizing and aggressive environments. The properties of MoSi{sub 2} which make it an attractive matrix for high temperature composites are described and the development history of these materials traced. Latest results on elevated temperature creep resistance, low temperature fracture toughness, and composite oxidation behavior are summarized. Important avenues for future MoSi{sub 2} based composite development are suggested.

  18. In vitro and in vivo evaluation of a polylactic acid-bioactive glass composite for bone fixation devices.

    PubMed

    Vergnol, Gwenaelle; Ginsac, Nathalie; Rivory, Pascaline; Meille, Sylvain; Chenal, Jean-Marc; Balvay, Sandra; Chevalier, Jérôme; Hartmann, Daniel J

    2016-01-01

    Poly(lactic acid) is nowadays among the most used bioabsorbable materials for medical devices. To promote bone growth on the material surface and increase the degradation rate of the polymer, research is currently focused on organic-inorganic composites by adding a bioactive mineral to the polymer matrix. The purpose of this study was to investigate the ability of a poly(L,DL-lactide)-Bioglass® (P(L,DL)LA-Bioglass(®) 45S5) composite to be used as a bone fixation device. In vitro cell viability testing of P(l,dl)LA based composites containing different amounts of Bioglass(®) 45S5 particles was investigated. According to the degradation rate of the P(L,DL)LA matrix and the cytocompatibility experiments, the composite with 30 wt % of Bioglass® particles seemed to be the best candidate for further investigation. To study its behavior after immersion in simulated physiological conditions, the degradation of the composite was analyzed by measuring its weight loss and mechanical properties and by proceeding with X-ray tomography. We demonstrated that the presence of the bioactive glass significantly accelerated the in vitro degradation of the polymer. A preliminary in vivo investigation on rabbits shows that the addition of 30 wt % of Bioglass(®) in the P(L,DL)LA matrix seems to trigger bone osseointegration especially during the first month of implantation. This composite has thus strong potential interest for health applications.

  19. Sire variation in fatty acid composition of crossbred Wagyu steers and heifers.

    PubMed

    Elías Calles, J A; Gaskins, C T; Busboom, J R; Duckett, S K; Cronrath, J D; Reeves, J J

    2000-09-01

    Effects of sires on lipid composition of subcutaneous adipose tissue and longissimus dorsi muscle were studied using 113 F(1) heifer and steer calves sired by eight Wagyu bulls out of three different cow herds. Wagyu sires were used and grouped as Old (n=6) and New (n =2) sires, respectively, based on the chronological order in which they were imported into the US. Animals were fed a backgrounding diet for 112 days consisting of an 80:20 ratio of roughage:concentrate, then grazed on orchard grass and bluegrass for 84 days, and finished on a 10:90 ratio of roughage:concentrate diet for 231 days in a feedlot. For longissimus dorsi muscle, progeny from Old sires had higher (P<0.05) monounsaturated to saturated fatty acid ratios (MUFA:SFA) than progeny of New sires. There were also differences (P<0.05) among individual sires for polyunsaturated to saturated fatty acid ratio (PUFA:SFA) (0.05-0.08) and MUFA:SFA (1.03-1.21). Progeny of Angus cows at Washington State University (WSU) had lower (P<0.05) MUFA:SFA and lower SFA than progeny of WSU crossbred and commercial cows. Steers had lower (P<0.05) MUFA:SFA and higher (P<0.05) SFA than heifers. For subcutaneous fat, heifers had higher levels (P<0.05) of linoleic acid (C18:2) and PUFA:SFA than the steers. Means for ether extractable fat in longissimus dorsi muscle differed among sires (P<0.05) and ranged from 7.58 to 13.13%. Progeny from WSU Angus cows had higher (P<0.05) ether extractable fat than WSU crossbred and commercial cows. Cholesterol content of longissimus dorsi muscle was not influenced by sire, cow herd or sex (P>0.05).

  20. Relationship between membrane fatty acid composition and heat resistance of acid and cold stressed Salmonella senftenberg CECT 4384.

    PubMed

    Alvarez-Ordóñez, Avelino; Fernández, Ana; López, Mercedes; Bernardo, Ana

    2009-05-01

    This study evaluates the adaptative response to heat (63 degrees C) and the modifications in membrane fatty acid composition of Salmonella senftenberg after its growth in an acidified medium and after its exposure to combinations of acid and cold stresses. Cells were grown in Brain Heart Infusion (BHI) buffered at pH 7.0 and acidified up to pH 4.5 (fresh cultures) and kept at refrigeration temperature (4 degrees C) for 7 days (refrigerated cultures). The results indicate that previous adaptation to a low pH increased the bacterial heat resistance, but combinations of sublethal stresses reduced S. senftenberg heat tolerance, specially when the growth medium pH was decreased. Acid-adapted cells showed D(63)-values ranging from 3.10 to 6.27 min, while non-acid-adapted cells showed D(63)-values of 1.07 min. As pH decreased, over the pH range studied (7.4-4.5), D(63)-values of the resulting cells increased. However, refrigerated acid-adapted cells showed lower D(63)-values, which ranged from 0.95 to 0.49 min. A linear relationship between the thermotolerance of S. senftenberg cells and the previous growth medium pH was found in both fresh and refrigerated cultures, which allowed us to predict changes in heat resistance of S. senftenberg that occur at any pH value within the range used in the present study in which most foodstuffs are included. Both acidification of the growth medium and refrigeration storage of cells induced modifications in membrane fatty acid composition, which were clearly linked to their heat resistance. Acid-adapted cells, regardless of the pH value of the growth medium, showed the lowest UFA/SFA ratio and a CFA content 1.5-2-fold higher than that observed for non-acid-adapted cells. On the other hand, the UFA/SFA ratio found for S. senftenberg cells exposed to a cold stress was 1.2-1.8-fold higher than that observed for non-refrigerated cultures. This increase in the UFA/SFA ratio was specially high for acid-adapted cells. The highest

  1. Genetic effects on fatty acid composition of carcass fat of Japanese Black Wagyu steers.

    PubMed

    Oka, A; Iwaki, F; Dohgo, T; Ohtagaki, S; Noda, M; Shiozaki, T; Endoh, O; Ozaki, M

    2002-04-01

    Two hundred ninety-three Japanese Black Wagyu steers derived from 34 sires were used to investigate genetic effects on the fatty acid composition of carcass fat. All steers were fed identical diets for 365 d and slaughtered at similar ages. If the percentage of genetic contribution of sire A, B, or C was not lower than 25%, steers were classified into groups A, B, and C, respectively. Fatty acid compositions differed depending on deposit sites. Mean percentage of monounsaturated fatty acids (MUFA) tended to be higher in the outer parts than in the inner parts of the body. Percentage of MUFA in carcass fat was negatively correlated with withers height and BW and positively correlated with meat quality score and marbling score. Fatty acid compositions of the 34 sire groups varied, and mean percentages of MUFA in i.m. fat ranged from 47.71 to 54.77%. Steers in the C group grew larger than those in the A or B group. Mean percentages of MUFA for i.m. fat in the A, B, and C groups (52.83, 51.88, and 50.33%, respectively) differed (P < 0.05) from each other. Steers in the C group had higher (P < 0.05) percentages of saturated fatty acids than those in the A or B groups. Percentages of genetic contribution of sires B (P < 0.05) and C (P < 0.001) were negatively correlated with percentage of MUFA in i.m. fat. These results suggested that genetic factors affected fatty acid composition of carcass fat in Japanese Black Wagyu cattle and that some sires had potent genetic factors affecting this composition.

  2. How to repair fillings made by silorane-based composites.

    PubMed

    Ivanovas, Sarah; Hickel, Reinhard; Ilie, Nicoleta

    2011-12-01

    In 2007, the low shrinkage silorane-based composites with a completely new resin chemistry were introduced. As for the case of composite repair, the question of whether this new material class can be repaired with the same methods like dimethacrylate-based composites arises. The ability of a silorane-based composite (SBC) to be repaired was therefore examined in a shear-bond test. Specimens of SBC were polymerised, water-stored at 37°C for 1 week and then repaired with fresh dimethacrylate-based composite (MBC) or SBC material by using several intermediate agents (IMA). The shear-bond strength was then measured after an additional water storage of 1 week. As IMA, we tested an experimental silorane-flowable composite, two dimethacrylate-based flowable composites, a filled silorane system adhesive bond and a conventional unfilled adhesive, a silane in addition to an adhesive as well as a repair kit. Additionally, repairs of MBC with dimethacrylate-based flowable composite were prepared. Specimens of MBC and SBC bonded to dentine with the corresponding adhesives were used as a reference. The repairs of MBC with the flowable composite resin Tetric Evo Flow exhibited the highest mean repair bond strength value (42.2 MPa). For repair of SBC, the highest shear-bond strengths were measured for repairs using a silane additionally to a dimethacrylate-based adhesive resin, followed by repairs with the experimental silorane-based flowable composite resin Hermes Flow as IMA. SBC can be repaired in combination with a MBC; then a silane coupling agent plus a dimethacrylate-based IMA should be used. A silorane flowable as IMA is the best choice when SBC is to be repaired with SBC.

  3. Lipid content and fatty acid composition of the digital cushion of bulls offered different amounts of linseed.

    PubMed

    Baird, L G; Dawson, L E R; Young, I S; O'Connell, N E

    2010-07-01

    demonstrates that dietary fatty acid composition influences the concentration of fatty acids incorporated in the digital cushion of cattle. Based on the large number of quadratic responses among the fatty acids, it appears there is a threshold amount of fatty acid incorporation in the digital cushion.

  4. On the composition of ammonia-sulfuric-acid ion clusters during aerosol particle formation

    NASA Astrophysics Data System (ADS)

    Schobesberger, S.; Franchin, A.; Bianchi, F.; Rondo, L.; Duplissy, J.; Kürten, A.; Ortega, I. K.; Metzger, A.; Schnitzhofer, R.; Almeida, J.; Amorim, A.; Dommen, J.; Dunne, E. M.; Ehn, M.; Gagné, S.; Ickes, L.; Junninen, H.; Hansel, A.; Kerminen, V.-M.; Kirkby, J.; Kupc, A.; Laaksonen, A.; Lehtipalo, K.; Mathot, S.; Onnela, A.; Petäjä, T.; Riccobono, F.; Santos, F. D.; Sipilä, M.; Tomé, A.; Tsagkogeorgas, G.; Viisanen, Y.; Wagner, P. E.; Wimmer, D.; Curtius, J.; Donahue, N. M.; Baltensperger, U.; Kulmala, M.; Worsnop, D. R.

    2015-01-01

    charged clusters grew on average by Δm/Δn = 1.05 and were only observed at sufficiently high [NH3] / [H2SO4]. The H2SO4 molecules of these clusters are partially neutralized by NH3, in close resemblance to the acid-base bindings of ammonium bisulfate. Supported by model simulations, we substantiate previous evidence for acid-base reactions being the essential mechanism behind the formation of these clusters under atmospheric conditions and up to sizes of at least 2 nm. Our results also suggest that electrically neutral NH3-H2SO4 clusters, unobservable in this study, have generally the same composition as ionic clusters for [NH3] / [H2SO4] > 10. We expect that NH3-H2SO4 clusters form and grow also mostly by Δm/Δn > 1 in the atmosphere's boundary layer, as [NH3] / [H2SO4] is mostly larger than 10. We compared our results from CLOUD with APi-TOF measurements of NH3-H2SO4 anion clusters during new-particle formation in the Finnish boreal forest. However, the exact role of NH3-H2SO4 clusters in boundary layer particle formation remains to be resolved.

  5. Comparison of Free Total Amino Acid Compositions and Their Functional Classifications in 13 Wild Edible Mushrooms.

    PubMed

    Sun, Liping; Liu, Qiuming; Bao, Changjun; Fan, Jian

    2017-02-24

    Thirteen popular wild edible mushroom species in Yunnan Province, Boletus bicolor, Boletus speciosus, Boletus sinicus, Boletus craspedius, Boletus griseus, Boletus ornatipes, Xerocomus, Suillus placidus, Boletinus pinetorus, Tricholoma terreum, Tricholomopsis lividipileata, Termitomyces microcarpus, and Amanita hemibapha, were analyzed for their free amino acid compositions by online pre-column derivazation reversed phase high-performance liquid chromatography (RP-HPLC) analysis. Twenty free amino acids, aspartic acid, glutamic acid, serine, glycine, alanine, praline, cysteine, valine, methionine, phenylalanine, isoleucine, leucine, lysine, histidine, threonine, asparagines, glutamine, arginine, tyrosine, and tryptophan, were determined. The total free amino acid (TAA) contents ranged from 1462.6 mg/100 g in B. craspedius to 13,106.2 mg/100 g in T. microcarpus. The different species showed distinct free amino acid profiles. The ratio of total essential amino acids (EAA) to TAA was 0.13-0.41. All of the analyzed species showed high contents of hydrophobic amino acids, at 33%-54% of TAA. Alanine, cysteine, glutamine, and glutamic acid were among the most abundant amino acids present in all species. The results showed that the analyzed mushrooms possessed significant free amino acid contents, which may be important compounds contributing to the typical mushroom taste, nutritional value, and potent antioxidant properties of these wild edible mushrooms. Furthermore, the principal component analysis (PCA) showed that the accumulative variance contribution rate of the first four principal components reached 94.39%. Cluster analysis revealed EAA composition and content might be an important parameter to separate the mushroom species, and T. microcarpus and A. hemibapha showed remarkable EAA content among the 13 species.

  6. Evaluation of cooling strategies for pumping of milk - impact of fatty acid composition on free fatty acid levels.

    PubMed

    Wiking, Lars; Bertram, Hanne C; Björck, Lennart; Nielsen, Jacob H

    2005-11-01

    Cooling strategies for pumping of raw milk were evaluated. Milk was pumped for 450 s at 31 degrees C, or pumped after cooling to 4 degrees C and subsequently subjected to various incubation times. Two types of milk were used; i.e. milk from cows fed a diet high in saturated fat supplements resulting in significantly larger milk fat globules than the other type of milk which comes from cows fed a low-fat diet that stimulates high de novo fat synthesis. The content of liquid fat was determined by low-field 1H NMR, which showed that milk from cows given the saturated fat diet also contained less liquid fat at both 4 degrees and 31 degrees C than the other type of milk. This can be ascribed to the differences in the fatty acid composition of the milk as a result of the fatty acid composition of the diets. After pumping of the milk at 31 degrees C, measurement of fat globule size distribution revealed a significant coalescence of milk fat globules in the milk obtained from the saturated fat diet due to pumping. Pumping at 4 degrees C or pumping the other type of milk did not result in coalescence of milk fat globules. Formation of free fatty acids increased significantly in both types of milk by pumping at 31 degrees C. Cooling the milk to 4 degrees C immediately before pumping inhibited an increased content of free fatty acids. However, when the milk was incubated at 4 degrees C for 60 min after cooling and then subjected to pumping, a significant increase in the formation of free fatty acids was observed in both types of milk. It is suggested that this increase in free fatty acids is caused by transition of polymorphic crystal forms or higher level of attached lipoprotein lipases to the milk fat globule before pumping.

  7. High-performance supercapacitors based on freestanding carbon-based composite paper electrodes

    NASA Astrophysics Data System (ADS)

    Yun, Young Soo; Lee, Min Eui; Joo, Min Jae; Jin, Hyoung-Joon

    2014-01-01

    Using a simple filtration method, we fabricate freestanding carbon-based composite paper electrodes (F-CCPEs), based on acid-treated carbon nanotubes (a-CNTs) and microporous carbon-based nanoplates containing numerous heteroatoms (H-CMNs). The F-CCPEs exhibited a high electrical conductivity of 2.3 × 102 S cm-1 and a high surface area of 1211.7 m2 g-1; moreover, they had numerous electroative heteroatoms and showed mechanical flexibility. Therefore, F-CCPEs without current collectors and binder show a superior electrochemical performance. In particular, the prepared F-CCPEs exhibit high capacitances of 275 and 148 F g-1 in aqueous and organic electrolytes, respectively. In addition, the specific energy density and specific power density of these F-CCPEs were found to be 63 Wh kg-1 and 140 kW kg-1, respectively, with good cyclic stability, even after 20,000 charge/discharge cycles.

  8. Development of polylactic acid-based materials through reactive modification

    NASA Astrophysics Data System (ADS)

    Fowlks, Alison Camille

    2009-12-01

    Polylactic acid (PLA)-based systems have shown to be of great potential for the development of materials requiring biobased content, biodegradation, and sufficient properties. The efforts in this study are directed toward addressing the current research need to overcome some of the inherent drawbacks of PLA. To meet this need, reactive extrusion was employed to develop new materials based on PLA by grafting, compounding, and polymer blending. In the first part of this work, maleic anhydride (MA) was grafted onto PLA by reactive extrusion. Two structurally different peroxides were used to initiate grafting and results were reported on the basis of grafting, molecular weight, and thermal behavior. An inverse relationship between degree of grafting and molecular weight was established. It was also found that, regardless of peroxide type, there is an optimum peroxid-to-MA ratio of 0.5:2 that promotes maximum grafting, beyond which degradation reactions become predominant. Overall, it was found that the maleated copolymer (MAPLA) could be used as an interfacial modifier in PLA-based composites. Therefore, MAPLA was incorporated into PLA-talc composites in varying concentrations. The influence of the MAPLA addition on the mechanical and thermal behavior was investigated. When added in an optimum concentration, MAPLA improved the tensile strength and crystallization of the composite. Furthermore, microscopic observation confirmed the compatibilization effect of MAPLA in PLA-talc composites. Vinyltrimethoxysilane was free-radically grafted onto the backbone of PLA and subsequently moisture crosslinked. The effects of monomer, initiator, and catalyst concentration on the degree of crosslinking and the mechanical and thermal properties were investigated. The presence of a small amount of catalyst showed to be a major contributor to the crosslinking formation in the time frame investigated, shown by an increase in gel content and decrease in crystallinity. Furthermore

  9. Scaling up of manufacturing processes of recycled carpet based composites

    NASA Astrophysics Data System (ADS)

    Lakshminarayanan, Krishnan

    2011-12-01

    In this work, feasibility of recycling post-consumer carpets using a modified vacuum assisted resisted molding process into large-scale components was successfully demonstrated. The scale up also included the incorporation of nano-clay films in the carpet composites. It is expected that the films will enhance the ability of the composite to withstand environmental degradation and also serve as a fire retardant. Low-cost resins were used to fabricate the recycled carpet-based composites. The scale up in terms of process was achieved by manufacturing composites without a hot press and thereby saving additional equipment cost. Mechanical and physical properties were evaluated. Large-scale samples demonstrated mechanical properties that were different from results from small samples. Acoustic tests indicate good sound absorption of the carpet composite. Cost analysis of the composite material based on the cost of the raw materials and the manufacturing process has been presented.

  10. Preliminary characterization and modeling of SMA-based textile composites

    NASA Astrophysics Data System (ADS)

    Masuda, Arata; Ni, Qing-Qing; Sone, Akira; Zhang, Run-Xin; Yamamura, Takahiko

    2004-07-01

    In this paper, we conduct a feasibility study to investigate the future potential of textile composites with shape memory alloys. Two different types of SMA-based textile composites are presented. First, a composite plate with embedded woven SMA layer is fabricated, and the stiffness tuning capability is evaluated by impact vibration tests. The results are not favorable, but may be improved by increasing the volume fraction of SMA, and by controlling the prestrain more accurately during the lamination process. The modeling and analysis methodology for woven SMA-based composites are briefly discussed. Then, the possibility of textile composites with SMA stitching is discussed, that is expected to give the composites multi-functions such as tunable stiffness, shape control and sensing capability, selectively distributed on demand.

  11. Modulation of fatty acid composition and growth in Sporosarcina species in response to temperatures and exogenous branched-chain amino acids.

    PubMed

    Tsuda, Kentaro; Nagano, Hideaki; Ando, Akinori; Shima, Jun; Ogawa, Jun

    2017-03-22

    Psychrotolerant endospore-forming Sporosarcina species have been predominantly isolated from minced fish meat (surimi), which is stored under refrigeration after heat treatment. To develop a better method for preserving surimi-based food products, we studied the growth and fatty acid compositions of the isolated strain S92h as well as Sporosarcina koreensis and Sporosarcina aquimarina at cold and moderate temperatures. The growth rates of strain S92h and S. koreensis were the fastest and slowest at cold temperatures, respectively, although these strains grew at a similar rate at moderate temperatures. In all three strains, the proportions of anteiso-C15:0 and unsaturated fatty acids (UFAs) were significantly higher at cold temperatures than at moderate temperatures. Furthermore, supplementation with valine, leucine, and isoleucine resulted in proportional increases in iso-C16:0, iso-C15:0, and anteiso-C15:0, respectively, among the fatty acid compositions of these strains. The proportions of the UFAs were also altered by the supplementation. At cold temperatures, the growth rates of strain S92h and S. koreensis, but not of S. aquimarina, were affected by supplementation with leucine. Supplementation with isoleucine enhanced the growth of S. koreensis at cold temperatures but not that of the other strains. Valine did not affect the growth of any strain. These results indicate that anteiso-C15:0 and UFAs both play important roles in the cold tolerance of the genus Sporosarcina and that these bacteria modulate their fatty acid compositions in response to the growth environment.

  12. Is the fatty acid composition of freshwater zoobenthic invertebrates controlled by phylogenetic or trophic factors?

    PubMed

    Makhutova, Olesia N; Sushchik, Nadezhda N; Gladyshev, Michail I; Ageev, Alexander V; Pryanichnikova, Ekaterina G; Kalachova, Galina S

    2011-08-01

    We studied the fatty acid (FA) content and composition of ten zoobenthic species of several taxonomic groups from different freshwater bodies. Special attention was paid to essential polyunsaturated fatty acids, eicosapentaenoic acid (EPA, 20:5n-3), docosahexaenoic acid (DHA, 22:6n-3), and arachidonic acid (ARA, 20:4n-6); and the n-3/n-6 and DHA/ARA ratios, which are important for consumers of higher trophic levels, i.e., fish. The content and ratios of these FA varied significantly in the studied zoobenthic species, consequently, the invertebrates were of different nutritional quality for fish. Eulimnogammarus viridis (Crustacea) and Dendrocoelopsis sp. (Turbellaria) had the highest nutrition value for fish concerning the content of EPA and DHA and n-3/n-6 and DHA/ARA ratios. Using canonical correspondence analysis we compared the FA profiles of species of the studied taxa taking into account their feeding strategies and habitats. We gained evidence that feeding strategy is of importance to determine fatty acid profiles of zoobenthic species. However, the phylogenetic position of the zoobenthic species is also responsible and may result in a similar fatty acid composition even if species or populations inhabit different water bodies or have different feeding strategies.

  13. Fatty acid composition and volatile compounds of caviar from farmed white sturgeon (Acipenser transmontanus).

    PubMed

    Caprino, Fabio; Moretti, Vittorio Maria; Bellagamba, Federica; Turchini, Giovanni Mario; Busetto, Maria Letizia; Giani, Ivan; Paleari, Maria Antonietta; Pazzaglia, Mario

    2008-06-09

    The present study was conducted to characterize caviar obtained from farmed white sturgeons (Acipenser transmontanus) subjected to different dietary treatments. Twenty caviar samples from fish fed two experimental diets containing different dietary lipid sources have been analysed for chemical composition, fatty acids and flavour volatile compounds. Fatty acid make up of caviar was only minimally influenced by dietary fatty acid composition. Irrespective of dietary treatments, palmitic acid (16:0) and oleic acid (OA, 18:1 n-9) were the most abundant fatty acid followed by docosahexaenoic acid (DHA, 22:6 n-3) and eicopentaenoic (EPA, 20:5 n-3). Thirty-three volatile compounds were isolated using simultaneous distillation-extraction (SDE) and identified by GC-MS. The largest group of volatiles were represented by aldehydes with 20 compounds, representing the 60% of the total volatiles. n-Alkanals, 2-alkenals and 2,4-alkadienals are largely the main responsible for a wide range of flavours in caviar from farmed white surgeon.

  14. Arguing for Computer-Based Composition Instruction.

    ERIC Educational Resources Information Center

    Larsen, Richard B.

    The English teaching profession must accept the fact that the new paradigm for composition involves microcomputers and word processors, and as such calls for a somewhat different set of skills on the part of both students and teachers. The "text editor" can lessen the effects of some physical and psychological constraints on students,…

  15. Effect of Finishing System on Subcutaneous Fat Melting Point and Fatty Acid Composition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Angus-cross steers (n = 69) were used to determine the effect of finishing system on subcutaneous fat melting point and fatty acid composition. Three finishing systems were evaluated: 1) mixed pasture for 134 d [MP], 2) mixed pasture for 93 d and alfalfa for 41 d [AL], or 3) concentrate finishing f...

  16. EVALUATION OF POLY(LACTIC ACID) AND AGRICULTURAL COPRODUCTS AS GREEN COMPOSITE MATERIALS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Green composite materials of poly(lactic acid)(PLA) and agricultural coproducts such as sugar beet pulp(SBP), cuphea, lesquerella, and milkweed were compounded using a twin-screw extruder, molded by injection molding and evaluated for structural and mechanical properties using acoustic emission and ...

  17. Gasoline compositions containing reaction products of fatty acid esters and amines as carburetor detergents

    SciTech Connect

    Schlicht, R.C.; Herbstman, S.; Levin, M.D.; Sung, R.L.

    1988-03-08

    A motor fuel composition is described comprising (a) a major portion of a fuel consisting essentially of a hydrocarbon boiling in the gasoline boiling range; and (b) a minor effective amount of, as detergent additive, a reaction product of C/sub 6/-C/sub 20/ fatty acid and a mono- or di-(hydroxy hydrocarbyl) amine.

  18. Antimicrobial activity of nisin incorporated in pectin and polylactic acid composite films against Listeria monocytogenes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extruded composite films from 20% pectin and 80% polylactic acids (PLA) were developed and nisin was loaded into films by a diffusion post extrusion. Inhibitory activities of the films against Listeria monocytogenes were evaluated in brain heart infusion (BHI) broth, liquid egg white and orange juic...

  19. Poly(lactic acid) and Osage Orange Wood Fiber Composites for Agricultural Mulch Films

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Osage orange wood(OO)was combined with poly(lactic acid)(PLA)to form a polymer composite intended for use as an agricultural mulch film. The PLA-OO mechanical properties were comparable to existing mulch film products and had the advantage of being completely biodegradable through a single growing ...

  20. Phenolic acids composition of fruit extracts of Ber (Ziziphus mauritiana L., var. Golo lemai)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruits of Ziziphus mauritiana L. (ber) are consumed in fresh and dried/processed form in many countries across Asia including Pakistan. In the present study, we analyzed the composition of total phenolic acids (free, soluble-bound and insoluble-bound) from Golo lemai ber fruit extracts by applying a...

  1. Pseudo and true visible light photocatalytic activity of nanotube titanic acid/graphene composites

    NASA Astrophysics Data System (ADS)

    Wang, Xiaodong; Liu, Xiaogang; Xue, Xiaoxiao; Pan, Hui; Zhang, Min; Li, Qiuye; Yu, Laigui; Yang, Jianjun; Zhang, Zhijun

    2013-09-01

    Nanotube titanic acid/graphene (NTA/Gr) composites were prepared by an easy hydrothermal treatment of graphene oxide (GO) and NTA in a mixed solvent of ethanol-water. As-prepared NTA/Gr composites and GO were characterized by means of Fourier transform infrared spectrometry, X-ray diffraction, diffuse-reflection spectrometry, thermal analysis, and transmission electron microscopy. Besides, the photocatalytic activities of as-prepared NTA/Gr composites were evaluated by monitoring the degradation of methyl orange (MO) under visible light irradiation. It has been found that extending hydrothermal reaction time (24 h instead of 3 h) leads to great changes in the morphology and crystal structure of as-prepared composites. Namely, the orthorhombic NTA (ca. 10 nm in diameter) in the composite transformed to anatase TiO2 particle (ca. 20-30 nm in diameter) while the Gr sheets (with micrometers-long wrinkles) in it transformed to a few Gr fragments (ca. 50 nm in diameter). Correspondingly, the NTA/Gr composite transformed to titanium dioxide/graphene (TiO2/Gr) composite. In the meantime, pure GO only has adsorption effect but it has no photocatalytic activity in the visible light region. Nevertheless, increasing Gr ratio results in enhanced visible light absorption capability and photocatalytic activity of NTA/Gr composites as well as the TiO2/Gr composites. This demonstrates that the true visible light photocatalytic activity of NTA/Gr composites as well as the TiO2/Gr composites for the degradation of MO is not as excellent as expected, and their high apparent activity is attributed to the strong adsorption of MO on the composites.

  2. Fabrication of tungsten wire reinforced nickel-base alloy composites

    NASA Technical Reports Server (NTRS)

    Brentnall, W. D.; Toth, I. J.

    1974-01-01

    Fabrication methods for tungsten fiber reinforced nickel-base superalloy composites were investigated. Three matrix alloys in pre-alloyed powder or rolled sheet form were evaluated in terms of fabricability into composite monotape and multi-ply forms. The utility of monotapes for fabricating more complex shapes was demonstrated. Preliminary 1093C (2000F) stress rupture tests indicated that efficient utilization of fiber strength was achieved in composites fabricated by diffusion bonding processes. The fabrication of thermal fatigue specimens is also described.

  3. Metal-ceramic composite development based on its modelling results

    NASA Astrophysics Data System (ADS)

    Dvilis, E. S.; Khasanov, O. L.; Khasanov, A. O.; Petyukevich, M. S.

    2016-02-01

    The modeling (and its experimental verification) of packing and deformation of the composites consisted of aluminum-magnesium alloy AMg6, B4C powder and W nano-powder has been performed. The powder compositions were determined using discrete element modeling of the composite particles packing based on the particle size distribution functions of real powders. The models of maximum mixture packing densities have been rendered.

  4. A protein delivery system: biodegradable alginate-chitosan-poly(lactic-co-glycolic acid) composite microspheres.

    PubMed

    Zheng, Cai-Hong; Gao, Jian-Qing; Zhang, Ye-Ping; Liang, Wen-Quan

    2004-10-29

    In the present study we developed alginate-chitosan-poly(lactic-co-glycolic acid) (PLGA) composite microspheres to elevate protein entrapment efficiency and decrease its burst release. Bovine serum albumin (BSA), which used as the model protein, was entrapped into the alginate microcapsules by a modified emulsification method in an isopropyl alcohol-washed way. The rapid drug releases were sustained by chitosan coating. To obtain the desired release properties, the alginate-chitosan microcapsules were further incorporated in the PLGA to form the composite microspheres. The average diameter of the composite microcapsules was 31+/-9microm and the encapsulation efficiency was 81-87%, while that of conventional PLGA microspheres was just 61-65%. Furthermore, the burst releases at 1h of BSA entrapped in composite microspheres which containing PLGA (50:50) and PLGA (70:30) decreased to 24% and 8% in PBS, and further decreased to 5% and 2% in saline. On the contrary, the burst releases of conventional PLGA microspheres were 48% and 52% in PBS, respectively. Moreover, the release profiles could be manipulated by regulating the ratios of poly(lactic acid) to poly(glycolic acid) in the composite microspheres.

  5. Choice of solvent extraction technique affects fatty acid composition of pistachio (Pistacia vera L.) oil.

    PubMed

    Abdolshahi, Anna; Majd, Mojtaba Heydari; Rad, Javad Sharifi; Taheri, Mehrdad; Shabani, Aliakbar; Teixeira da Silva, Jaime A

    2015-04-01

    Pistachio (Pistacia vera L.) oil has important nutritional and therapeutic properties because of its high concentration of essential fatty acids. The extraction method used to obtain natural compounds from raw material is critical for product quality, in particular to protect nutritional value. This study compared the fatty acid composition of pistachio oil extracted by two conventional procedures, Soxhlet extraction and maceration, analyzed by a gas chromatography-flame ionization detector (GC-FID). Four solvents with different polarities were tested: n-hexane (Hx), dichloromethane (DCM), ethyl acetate (EtAc) and ethanol (EtOH). The highest unsaturated fatty acid content (88.493 %) was obtained by Soxhlet extraction with EtAc. The Soxhlet method extracted the most oleic and linolenic acids (51.99 % and 0.385 %, respectively) although a higher concentration (36.32 %) of linoleic acid was extracted by maceration.

  6. Effect of ocean acidification on the fatty acid composition of a natural plankton community

    NASA Astrophysics Data System (ADS)

    Leu, E.; Daase, M.; Schulz, K. G.; Stuhr, A.; Riebesell, U.

    2012-07-01

    The effect of ocean acidification on the fatty acid composition of a natural plankton community in the Arctic was studied in a large-scale mesocosm experiment, carried out in Kongsfjorden (Svalbard, Norway) at 79° N. Nine mesocosms of ~50 cbm each were exposed to different pCO2 levels (from natural background conditions to ~1420 μatm), yielding pH values (on the total scale) from ~8.3 to 7.5. Inorganic nutrients were added on day 13. The phytoplankton development during this 30 days experiment passed three distinct phases: (1) prior to the addition of inorganic nutrients, (2) first bloom after nutrient addition, and (3) second bloom after nutrient addition. The fatty acid composition of the natural plankton community was analysed and showed, in general, high percentages of polyunsaturated fatty acids (PUFAs): 44-60% of total fatty acids. Positive correlations with pCO2 were found for most PUFAs during phases 2 and/or 3, with the exception of 20:5n3 (eicosapentaenoic acid, EPA), an important diatom marker. There are strong indications for these correlations being mediated indirectly through taxonomic changes and the natural development of the communities in the mesocosms exposed to different pCO2 levels. While diatoms increased during phase 3 mainly in the low and intermediate pCO2 treatments, dinoflagellates were favoured by high CO2 concentrations during the same time period. This is reflected in the development of group-specific fatty acid trophic markers. No indications were found for a generally detrimental effect of ocean acidification on the planktonic food quality in terms of essential fatty acids. The significant positive correlations between most PUFAs and pCO2 reflected treatment-dependent differences in the community composition between the mesocosms rather than a direct positive effect of pCO2 on specific fatty acids.

  7. Use of super acids to digest chrysotile and amosite asbestos in simple mixtures or matrices found in building materials compositions

    SciTech Connect

    Sugama, T.; Petrakis, L.; Webster, R.P.

    1999-12-21

    A composition for converting asbestos-containing material to environmentally benign components is provided. The composition comprises a fluoro acid decomposing agent which can be applied to either amosite-containing thermal insulation or chrysotile-containing fire-proof material or to any asbestos-containing material which includes of chrysotile and amosite asbestos. The fluoro acid decomposing agent includes FP{sub 0}(OH){sub 2}, hexafluorophosphoric acid, a mixture of hydrofluoric and phosphoric acid and a mixture of hexafluorophosphoric acid and phosphoric acid. A method for converting asbestos-containing material to environmentally benign components is also provided.

  8. The amino acid composition of the Sutter's Mill CM2 carbonaceous chondrite

    NASA Astrophysics Data System (ADS)

    Burton, Aaron S.; Glavin, Daniel P.; Elsila, Jamie E.; Dworkin, Jason P.; Jenniskens, Peter; Yin, Qing-Zhu

    2014-11-01

    We determined the abundances and enantiomeric compositions of amino acids in Sutter's Mill fragment #2 (designated SM2) recovered prior to heavy rains that fell April 25-26, 2012, and two other meteorite fragments, SM12 and SM51, that were recovered postrain. We also determined the abundance, enantiomeric, and isotopic compositions of amino acids in soil from the recovery site of fragment SM51. The three meteorite stones experienced terrestrial amino acid contamination, as evidenced by the low D/L ratios of several proteinogenic amino acids. The D/L ratios were higher in SM2 than in SM12 and SM51, consistent with rain introducing additional L-amino acid contaminants to SM12 and SM51. Higher percentages of glycine, β-alanine, and γ-amino-n-butyric acid were observed in free form in SM2 and SM51 compared with the soil, suggesting that these free amino acids may be indigenous. Trace levels of D+L-β-aminoisobutyric acid (β-AIB) observed in all three meteorites are not easily explained as terrestrial contamination, as β-AIB is rare on Earth and was not detected in the soil. Bulk carbon and nitrogen and isotopic ratios of the SM samples and the soil also indicate terrestrial contamination, as does compound-specific isotopic analysis of the amino acids in the soil. The amino acid abundances in SM2, the most pristine SM meteorite analyzed here, are approximately 20-fold lower than in the Murchison CM2 carbonaceous chondrite. This may be due to thermal metamorphism in the Sutter's Mill parent body at temperatures greater than observed for other aqueously altered CM2 meteorites.

  9. Fatty acid composition of freshwater wild fish in subalpine lakes: a comparative study.

    PubMed

    Vasconi, Mauro; Caprino, Fabio; Bellagamba, Federica; Busetto, Maria Letizia; Bernardi, Cristian; Puzzi, Cesare; Moretti, Vittorio Maria

    2015-03-01

    In this study, the proximate and fatty acid compositions of the muscle tissue of 186 samples of fish belonging to fifteen species of freshwater fish harvested in subalpine lakes (bleak, shad, crucian carp, whitefish, common carp, pike, black bullhead, burbot, perch, Italian roach, roach, rudd, wels catfish, chub and tench) were investigated. Most of the fish demonstrated a lipid content in the fillet lower than 2.0 g 100 g(-1) wet weight (range 0.6-9.7). A strong relationship between feeding behavior and fatty acid composition of the muscle lipids was observed. Planktivorous fish showed the lowest amounts of n-3 fatty acids (p < 0.05), but the highest monounsaturated fatty acid (MUFA) contents, in particular 18:1n-9. Conversely, carnivorous fish showed the highest amounts of saturated fatty acids and n-3 fatty acids (p < 0.05), but the lowest MUFA contents. Omnivorous fish showed substantial proportions of n-3 fatty acids and the highest contents of n-6 fatty acids. Principal component analysis showed a distinct separation between fish species according to their feeding habits and demonstrated that the most contributing trophic markers were 18:1n-9, 18:3n-3, 22:6n-3 and 20:4n-6. The quantitative amounts n-3 polyunsaturated fatty acid in muscle tissues varied depending on the fish species, the lipid content and the feeding habits. Some species were very lean, and therefore would be poor choices for human consumption to meet dietary n-3 fatty acid requirements. Nevertheless, the more frequently consumed and appreciated fish, shad and whitefish, had EPA and DHA contents in the range 900-1,000 mg 100 g(-1) fresh fillet.

  10. Composition-based effective chain length for prediction of protein folding rates

    NASA Astrophysics Data System (ADS)

    Chang, Le; Wang, Jun; Wang, Wei

    2010-11-01

    Folding rate prediction is a useful way to find the key factors affecting folding kinetics of proteins. Structural information is more or less required in the present prediction methods, which limits the application of these methods to various proteins. In this work, an “effective length” is defined solely based on the composition of a protein, namely, the number of specific types of amino acids in a protein. A physical theory based on a minimalist model is employed to describe the relation between the folding rates and the effective length of proteins. Based on the resultant relationship between folding rates and effective length, the optimal sets of amino acids are found through the enumeration over all possible combinations of amino acids. This optimal set achieves a high correlation (with the coefficient of 0.84) between the folding rates and the optimal effective length. The features of these amino acids are consistent with our model and landscape theory. Further comparisons between our effective length and other factors are carried out. The effective length is physically consistent with structure-based prediction methods and has the best predictability for folding rates. These results all suggest that both entropy and energetics contribute importantly to folding kinetics. The ability to accurately and efficiently predict folding rates from composition enables the analysis of the kinetics for various kinds of proteins. The underlying physics in our method may be helpful to stimulate further understanding on the effects of various amino acids in folding dynamics.

  11. Molecular size and amino acid composition of H-2d antigen solubilized in Nonidet P-40.

    PubMed

    Rossowski, W; Kloczewiak, M; Radzikowski, C; Strzadala, L

    1976-01-01

    H-2d antigenic material solubilized by the detergent Nonidet P-40 from L-1210 mouse leukemia cells was isolated by gel filtration on Bio-Gel P-100. A single peak eluted in the void volume consisted of about 90% protein, 8% hexose and traces of sialic acids. In sedimentation velocity runs, the antigen sedimented as a single peak of 3-1 S. Molecular weight determined by sedimentation equilibrium as well as calculated from amino acid composition was found to be in the range of 53,000 daltons and approx. 45,000-51,000 when calculated from sodium dodecyl sulfate polyacrylamide gel electrophoresis. Secondary structure of H-2d glycoprotein was predicted from the amino acid composition. For NP-40-solubilized H-2d antigen, about 34% of helix, 13% beta sheet and 41% turns was found.

  12. Composite separators and redox flow batteries based on porous separators

    DOEpatents

    Li, Bin; Wei, Xiaoliang; Luo, Qingtao; Nie, Zimin; Wang, Wei; Sprenkle, Vincent L.

    2016-01-12

    Composite separators having a porous structure and including acid-stable, hydrophilic, inorganic particles enmeshed in a substantially fully fluorinated polyolefin matrix can be utilized in a number of applications. The inorganic particles can provide hydrophilic characteristics. The pores of the separator result in good selectivity and electrical conductivity. The fluorinated polymeric backbone can result in high chemical stability. Accordingly, one application of the composite separators is in redox flow batteries as low cost membranes. In such applications, the composite separator can also enable additional property-enhancing features compared to ion-exchange membranes. For example, simple capacity control can be achieved through hydraulic pressure by balancing the volumes of electrolyte on each side of the separator. While a porous separator can also allow for volume and pressure regulation, in RFBs that utilize corrosive and/or oxidizing compounds, the composite separators described herein are preferable for their robustness in the presence of such compounds.

  13. Renal contribution to acid-base regulation during the menstrual cycle.

    PubMed

    Takano, N; Kaneda, T

    1983-03-01

    Menstruating women exhibit a light but sustained hypocapnia during the luteal phase. To elucidate whether the hypocapnia results primarily from a respiratory or renal mechanism, we measured the rate of urinary excretion of acid at intervals during the menstrual cycle in five subjects. The acid-base composition of arterial blood in three subjects and end-tidal PCO2 in the remaining two subjects were also determined. During the follicular phase, the acid-base composition of blood and the rate of net acid excretion remained virtually constant. After ovulation, significant decreases in PaCO2 (3.5 mmHg), [HCO3]p (2 meq/liter), and net acid excretion (2 meq/h) occurred in the first 4-6 days of the luteal phase (14 days long). Following this, net acid excretion returned to the preovulatory level. PaCO2 and [HCO3]p, however, remained decreased for 3 more days. At the end of the luteal phase, restoration of PaCO2 proceeded faster than that of [HCO3]p. The acid-base changes in blood and urine observed during the luteal phase were comparable to those occurring during adaptation and recovery from sustained hypocapnia, suggesting that hypocapnia during the luteal phase is primarily respiratory in origin.

  14. Short communication: The effect of substituting fish oil in dairy cow diets with docosahexaenoic acid-micro algae on milk composition and fatty acids profile.

    PubMed

    Abughazaleh, A A; Potu, R B; Ibrahim, S

    2009-12-01

    The effects of substituting fish oil (FO) with docosahexaenoic acid (DHA)-micro algae on milk chemical and fatty acid composition were examined in this study. Twenty-four Holstein cows in mid lactation grazing on an alfalfa-grass based pasture were divided into 4 treatment groups (6 cows/treatment) and supplemented with 7 kg/d grain mix plus 350 g of soybean oil and one of the following: 1) 150 g of FO, 2) 100 g of FO plus 50 g of algae, 3) 50 g of FO plus 100 g of algae, or 4) 150 g of algae. Cows were fed treatment diets for 3 wk, and milk samples were collected from each cow during the last 3 d of the study. Milk production (17.96, 17.56, 17.55, and 19.26 kg/d for treatment diets 1 to 4, respectively), milk fat percentages (3.17, 3.49, 3.74, and 3.43%), and milk protein percentages (3.35, 3.50, 3.71, and 3.42%) were similar between treatment diets. Concentrations (g/100 g of fatty acids) of milk cis-9 trans-11 (c9t11) conjugated linoleic acid (CLA; 3.41, 3.69, 4.47, and 4.21 for treatment diets 1 to 4, respectively) and vaccenic acid (11.80, 12.83, 13.87, and 13.53) were similar between treatment diets. Results of this study suggest that DHA-micro algae can partially or fully substitute FO in a cow's diet without any adverse effects on milk production, milk composition, or milk c9t11 CLA content. The DHA-micro algae may be used as a viable alternative for FO in cow's diet to modify rumen biohydrogenation to increase milk c9t11 CLA content.

  15. Composite biodegradable biopolymer coatings of silk fibroin - Poly(3-hydroxybutyric-acid-co-3-hydroxyvaleric-acid) for biomedical applications

    NASA Astrophysics Data System (ADS)

    Miroiu, Floralice Marimona; Stefan, Nicolaie; Visan, Anita Ioana; Nita, Cristina; Luculescu, Catalin Romeo; Rasoga, Oana; Socol, Marcela; Zgura, Irina; Cristescu, Rodica; Craciun, Doina; Socol, Gabriel

    2015-11-01

    Composite silk fibroin-poly(3-hydroxybutyric-acid-co-3-hydroxyvaleric-acid) (SF-PHBV) biodegradable coatings were grown by Matrix Assisted Pulsed Laser Evaporation on titanium substrates. Their physico-chemical properties and particularly the degradation behavior in simulated body fluid at 37 °C were studied as first step of applicability in local controlled release for tissue regeneration applications. SF and PHBV, natural biopolymers with excellent biocompatibility, but different biodegradability and tensile strength properties, were combined in a composite to improve their properties as coatings for biomedical uses. FTIR analyses showed the stoichiometric transfer from targets to coatings by the presence in the spectra of the main absorption maxima characteristic of both polymers. XRD investigations confirmed the FTIR results showing differences in crystallization behavior with respect to the SF and PHBV content. Contact angle values obtained through wettability measurements indicated the MAPLE deposited coatings were highly hydrophilic; surfaces turning hydrophobic with the increase of the PHBV component. Degradation assays proved that higher PHBV contents resulted in enhanced resistance and a slower degradation rate of composite coatings in SBF. Distinct drug-release schemes could be obtained by adjusting the SF:PHBV ratio to controllably tuning the coatings degradation rate, from rapid-release formulas, where SF predominates, to prolonged sustained ones, for larger PHBV content.

  16. Acid rain damage to carbonate stone: a quantitative assessment based on the aqueous geochemistry of rainfall runoff from stone

    USGS Publications Warehouse

    Reddy, M.M.

    1988-01-01

    An onsite experimental procedure was used to identify and quantify acid rain damage to carbonate stone, based on the change in rain runoff chemical composition. Onsite data obtained during the summer and fall of 1984 at three locations in the northeastern United States indicate that carbonate stone surface recession is related to acid deposition. -from Author

  17. Acid-base bifunctional catalytic surfaces for nucleophilic addition reactions.

    PubMed

    Motokura, Ken; Tada, Mizuki; Iwasawa, Yasuhiro

    2008-09-01

    This article illustrates the modification of oxide surfaces with organic amine functional groups to create acid-base bifunctional catalysts, summarizing our previous reports and also presenting new data. Immobilization of organic amines as bases on inorganic solid-acid surfaces afforded highly active acid-base bifunctional catalysts, which enabled various organic transformations including C--C coupling reactions, though these reactions did not proceed with either the homogeneous amine precursors or the acidic supports alone. Spectroscopic characterization, such as by solid-state MAS NMR and FTIR, revealed not only the interactions between acidic and basic sites but also bifunctional catalytic reaction mechanisms.

  18. Dietary n-3 polyunsaturated fatty acids modify fatty acid composition in hepatic and abdominal adipose tissue of sucrose-induced obese rats.

    PubMed

    Alexander-Aguilera, Alfonso; Berruezo, Silvia; Hernández-Diaz, Guillermo; Angulo, Ofelia; Oliart-Ros, Rosamaria

    2011-12-01

    The fatty acid profile of hepatocytes and adipocytes is determined by the composition of the dietary lipids. It remains unclear which fatty acid components contribute to the development or reduction of insulin resistance. The present work examined the fatty acid composition of both tissues in sucrose-induced obese rats receiving fish oil to determine whether the effect of dietary (n-3) polyunsaturated fatty acids (PUFAs) on the reversion of metabolic syndrome in these rats is associated to changes in the fatty acid composition of hepatocyte and adipocyte membrane lipids. Animals with metabolic syndrome were divided into a corn-canola oil diet group and a fish oil diet group, and tissues fatty acids composition were analyzed after 6 weeks of dietary treatment. Fatty acid profiles of the total membrane lipids were modified by the fatty acid composition of the diets fed to rats. N-3 PUFAs levels in animals receiving the fish oil diet plus sucrose in drinking water were significantly higher than in animals under corn-canola oil diets. It is concluded that in sucrose-induced obese rats, consumption of dietary fish oil had beneficial effects on the metabolic syndrome and that such effects would be conditioned by the changes in the n-3 PUFAs composition in hepatic and adipose tissues because they alter membrane properties and modify the type of substrates available for the production of active lipid metabolites acting on insulin resistance and obesity.

  19. Chia (Salvia hispanica L.) seed as an n-3 fatty acid source for finishing pigs: effects on fatty acid composition and fat stability of the meat and internal fat, growth performance, and meat sensory characteristics.

    PubMed

    Coates, W; Ayerza, R

    2009-11-01

    Coronary heart disease is caused by arteriosclerosis, which is triggered by an unbalanced fatty acid profile in the body. Today, Western diets are typically low in n-3 fatty acids and high in SFA and n-6 fatty acids; consequently, healthier foods are needed. Chia seed (Salvia hispanica L.), which contains the greatest known plant source of n-3 alpha-linolenic acid, was fed at the rate of 10 and 20% to finishing pigs, with the goal to determine if this new crop would increase the n-3 content of the meat as has been reported for other n-3 fatty acid-rich crops. The effects of chia on fatty acid composition of the meat, internal fats, growth performance, and meat sensory characteristics were determined. Productive performance was unaffected by dietary treatment. Chia seed modified the fatty acid composition of the meat fat, but not of the internal fat. Significantly (P < 0.05) less palmitic, stearic, and arachidic acids were found with both chia treatments. This is different than trials in which flaxseed, another plant based source of omega-3 fatty acid, has been fed. Alpha-linolenic acid content increased with increasing chia content of the diet; however, only the effect of the 20% ration was significantly (P < 0.05) different from that of the control. Chia seed increased panel member preferences for aroma and flavor of the meat. This study tends to show that chia seems to be a viable feed that can produce healthier pork for human consumption.

  20. New composite membranes based on modified Nafion or Flemion for PEM fuel cell application

    NASA Astrophysics Data System (ADS)

    Tian, Huimin

    A new composite membrane based on Nafion or Flemion and Silicotungstic acid (STA) was fabricated using a simple solvent evaporation procedure. The optimum evaporation temperature and the amount of STA have been investigated. The evaporation of solvent can be divided into two steps during membrane preparation. Firstly, the solvent was evaporated at 70°C for two hours. Secondly, the evaporated membrane was kept in an vacuum oven at 135°C overnight. The optimum amount of STA in the casting electrolyte solution is in the range from 5 x 10-4 to 5 x 10-3 M. The obtained cast composite membranes exhibit good thermal and mechanical properties. Study of the ionic conductivity shows that the composite membrane with STA gives a higher ionic conductivity than that without STA. The conductivity of composite membrane increases with the increase of STA concentration. When the STA concentration in the 10mL casting electrolyte solution is 5 x 10-3M, the conductivities of the composite membranes can reach up to 0.120 ohm-1 · cm-1 for Nafion/STA membrane and 0.133 ohm -1 · cm-1 for Flemion/STA membrane. On the other hand, the water uptake measurement shows that the water content of the composite membrane with STA is higher than that of composite membrane without STA. Consequently, due to the high conductivity and the high hydrated abiliy of STA, ionic conductivity and water uptake of the composite membrane can be significantly improved by the addition of STA. The morphology of the composite membrane was studied using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The results of AFM and SEM showed that the STA was uniformly dispersed in the Nafion and Flemion composite membranes. The structure of a composite membrane with STA has been studied by X-ray diffraction (XRD), the fourier transform infrared spectroscopy (FTIR), thermoanalysis and X-ray photoelectron spectroscopy (XPS). The results indicated that STA was successfully introduced into the structure of

  1. Thermochemical comparisons of homogeneous and heterogeneous acids and bases. 1. Sulfonic acid solutions and resins as prototype Broensted acids

    SciTech Connect

    Arnett, E.M.; Haaksma, R.A.; Chawla, B.; Healy, M.H.

    1986-08-06

    Heats of ionization by thermometric titration for a series of bases (or acids) can be used to compare solid acids (or bases) with liquid analogues bearing the same functionalities in homogeneous solutions. The method is demonstrated for Broensted acids by reacting a series of substituted nitrogen bases with solutions of p-toluenesulfonic acid (PTSA) in acetonitrile and with suspensions of the microporous polymeric arylsulfonic acid resin-Dowex 50W-X8 in the same solvent. Under well-controlled anhydrous conditions there is a good correlation (r = 0.992) between the heats of reaction of the bases with the homogeneous and heterogeneous acid systems, but the homogeneous system gives a more exothermic interaction by 3-4 kcal mol/sup -1/ for a series of 29 substituted pyrimidines, anilines, and some other amines. This difference may be attributed to homohydrogen bonding interactions between excess acid and sulfonate anion sites which are more restricted geometrically in the resin than in solution. Other factors which affect the enthalpy change for the acid-base interaction are the acid/base ratio, the water content of the sulfonic acid, the solvent, and the resin structure (e.g., microporous vs. macroporous). Steric hindrance in the base does not differentiate solid from homogeneous acid. In addition to the use of titration calorimetry, heats of immersion are reported for the Dowex-arylsulfonic acid resins and the Nafion-perfluorinated sulfonic acid resin in a series of basic liquids. The results are compared with each other and with those from a previous study of several varieties of coal.

  2. Fatty acid, triacylglycerol, and phytosterol composition in six Tunisian olive varieties.

    PubMed

    Haddada, Faouzia M; Manaï, Hédia; Oueslati, Imen; Daoud, Douja; Sánchez, Jacinto; Osorio, Emilio; Zarrouk, Mokhtar

    2007-12-26

    The physicochemical and stability properties as well as the fatty acid, triacylglycerol, sterol, and triterpenic dialcohol compositions of Tunisian olive oil varieties were analyzed. On the basis of our results, we classified all of the monovarietal oils into the extra virgin category. Oleic and linoleic acids were the most useful fatty acids to discriminate three cultivars, Neb Jmel, Chétoui, and Ain Jarboua, from the others. Of the six monovarietal virgin olive oils analyzed, the main triacylglycerols were OOO, POO, PLO plus SLL, and OLO, which was expected given the high oleic acid and low linoleic and linolenic acids content observed in total fatty acids. In total, these accounted for more than 80% of the total HPLC chromatogram peak area. The main sterols found were beta-sitosterol, Delta5-avenasterol, and campesterol. The statistical analysis showed significant differences between oil samples, and the obtained results showed a great variability in the oil composition between cultivars, which is influenced exclusively by genetic factors.

  3. Fatty acid composition of Juniperus species (Juniperus section) native to Turkey.

    PubMed

    Güvenç, Aysegül; Küçükboyaci, Nurgün; Gören, Ahmet Ceyhan

    2012-07-01

    Fatty acid compositions of seeds of five taxa of the Juniperus section of the genus Juniperus L. (Cupressaceae), i. e. J. drupacea Lab., J. communis L. var. communis, J. communis var. saxatilis Pall., J. oxycedrus L. subsp. oxycedrus, and J. oxycedrus subsp. macrocarpa (Sibth. & Sm.) Ball, were investigated. Methyl ester derivatized fatty acids of the lipophylic extracts of the five species were comparatively analyzed by capillary gas chromatography-mass spectrometry (GC-MS). Juniperus taxa showed uniform fatty acid patterns, among which linoleic (25.8 - 32.5%), pinolenic (11.9 - 24.1%) and oleic acids (12.4 - 17.2%) were determined to be the main fractions in the seed oils. Juniperonic acid was found to be remarkably high in J. communis var. saxatilis (11.4%), J. oxycedrus subsp. oxycedrus (10.4%), and J. communis var. communis (10.1%). To the best of our knowledge, the present work discloses the first report on the fatty acid compositions of seeds of this Juniperus section grown in Turkey.

  4. Fatty acid composition of symbiotic zooxanthellae in relation to their hosts.

    PubMed

    Bishop, D G; Kenrick, J R

    1980-10-01

    Gymnodinoid dinoflagellate symbionts, commonly referred to as zooxanthellae, are widely distributed among marine invertebrates. It has been assumed that they represent only one species,Gymnodinium microadriaticum. The fatty acid composition of total lipids and galactolipids of zooxanthellae isolated from 8 species of corals, 3 species of clams and a foraminiferan have been analyzed and found to vary according to the host. For example, the content of eicosapentaenoic acid in clam zooxanthellae monogalactosyldiacylglycerol was less than 2%, whereas in the same lipid from coral zooxanthellae, the content ranged from 9 to 22%. Corresponding values for the acid in digalactosyl-diacylglycerol were 1-8% from clam zooxanthellae and 23-40% from coral zooxanthellae. Coral zooxanthellae monogalactosyldiacylglycerol contain higher levels of octadecatetraenoic acid than are found in digalactosyldiacylglycerol, whereas the reverse is true in clam zooxanthellae. The fatty acid composition of the lipids of an axenic culture of zooxanthellae isolated from the clamTridacna maxima are similar to those of cells freshly isolated from the host. The results suggest either that the host is capable of affecting the fatty acid metabolism of the symbiont or that different strains of zooxanthellae occur in corals and clams.

  5. Cellular fatty acid compositions and isoprenoid quinone contents of 23 Legionella species.

    PubMed Central

    Lambert, M A; Moss, C W

    1989-01-01

    The cellular fatty acid compositions and ubiquinone contents of 182 Legionella strains representing 23 species were determined by capillary gas-liquid chromatography and reverse-phase high-performance liquid chromatography, respectively. Except for the type strain of Legionella erythra (ATCC 35303T), all Legionella species contained large (40 to 90%) amounts of branched-chain fatty acids and only trace to small (less than 0.5 to 5%) amounts of ester-linked hydroxy acids. The 23 species were placed in three major fatty acid groups on the basis of differences in the relative amounts of 14-methylpentadecanoic (Ci16:0), hexadecanoic (C16:1), and 12-methyltetradecanoic (Ca15:0) acids. All Legionella species contained ubiquinones with 9 to 14 isoprene units in the side chains and were divided into five different ubiquinone groups. The species were further differentiated into 16 groups on the basis of qualitative and quantitative differences in their fatty acid compositions and ubiquinone contents. Both of these chemical characteristics can be used to distinguish Legionella species from other gram-negative bacteria and rapidly and accurately identify suspected isolates before serologic and other tests are done. PMID:2715320

  6. Fatty acid composition of 12 fish species from the Black Sea.

    PubMed

    Huang, L-T C; Bülbül, U; Wen, P-C; Glew, R H; Ayaz, F A

    2012-05-01

    The long-chain polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are healthful to humans, particularly in promoting growth and cognitive development in infants and young children, and in reducing the risk of cardiovascular disease. Though the populations who inhabit the Trabzon province of Turkey include seafood from the Black Sea in their diet, knowledge of the fatty acid composition and content of these fish is scant. Fatty acid analysis was performed on freeze-dried muscle tissue of 12 species of fish purchased in markets in Trabzon. The fat content varied from 0.2% (garfish) to 12% (shad) of dry weight. The highest DHA and DHA plus EPA contents were found in horse mackerel 16.1 and 20.6 mg/g dry weight, respectively. Only in sea bass and sea bream did the essential fatty acid linoleic acid account for more than 10% of the fatty acid total. For all 12 species, arachidonic acid accounted for 0.09% to 7.64% of the fatty acid total. Oleic acid varied greatly from 0.14% (garfish) to 32.7% (shad). The omega-3/omega-6 fatty acid ratio ranged from 0.8 to 25. A 100 g serving of fresh horse mackerel would contribute 586 mg of DHA to the diet, which exceeds the recommended daily intake of 200 to 300 mg of DHA for pregnant and lactating women. These data indicate that some, but not all, of the 12 fish species from the Black Sea fish we studied could contribute significantly to satisfy the DHA and EPA needs of the inhabitants of the eastern Black Sea region of Turkey.

  7. On the composition of ammonia-sulfuric acid clusters during aerosol particle formation

    NASA Astrophysics Data System (ADS)

    Schobesberger, S.; Franchin, A.; Bianchi, F.; Rondo, L.; Duplissy, J.; Kürten, A.; Ortega, I. K.; Metzger, A.; Schnitzhofer, R.; Almeida, J.; Amorim, A.; Dommen, J.; Dunne, E. M.; Ehn, M.; Gagné, S.; Ickes, L.; Junninen, H.; Hansel, A.; Kerminen, V.-M.; Kirkby, J.; Kupc, A.; Laaksonen, A.; Lehtipalo, K.; Mathot, S.; Onnela, A.; Petäjä, T.; Riccobono, F.; Santos, F. D.; Sipilä, M.; Tomé, A.; Tsagkogeorgas, G.; Viisanen, Y.; Wagner, P. E.; Wimmer, D.; Curtius, J.; Donahue, N. M.; Baltensperger, U.; Kulmala, M.; Worsnop, D. R.

    2014-05-01

    The formation of particles from precursor vapors is an important source of atmospheric aerosol. Research at the Cosmics Leaving OUtdoor Droplets (CLOUD) facility at CERN tries to elucidate which vapors are responsible for this new particle formation, and how in detail it proceeds. Initial measurement campaigns at the CLOUD stainless-steel aerosol chamber focused on investigating particle formation from ammonia (NH3) and sulfuric acid (H2SO4). Experiments were conducted in the presence of water, ozone and sulfur dioxide. Contaminant trace gases were suppressed at the technological limit. For this study, we mapped out the compositions of small NH3-H2SO4 clusters over a wide range of atmospherically relevant environmental conditions. We covered [NH3] in the range from <2 to 1400 pptv, [H2SO4] from 3.3 × 106 to 1.4 × 109 cm-3, and a temperature range from -25 to +20 °C. Negatively and positively charged clusters were directly measured by an atmospheric pressure interface time-of-flight (APi-TOF) mass spectrometer, as they initially formed from gas-phase NH3 and H2SO4, and then grew to larger clusters containing more than 50 molecules of NH3 and H2SO4, corresponding to mobility-equivalent diameters greater than 2 nm. Water molecules evaporate from these clusters during sampling and are not observed. We found that the composition of the NH3-H2SO4 clusters is primarily determined by the ratio of gas-phase concentrations [NH3] / [H2SO4], as well as by temperature. Pure binary H2O-H2SO4 clusters (observed as clusters of only H2SO4) only form at [NH3] / [H2SO4]<0.1 to 1. For larger values of [NH3] / [H2SO4], the composition of NH3-H2SO4 clusters was characterized by the number of NH3 molecules m added for each added H2SO4 molecule n (Δm / Δn), where n is in the range 4-18 (negatively charged clusters) or 1-17 (positively charged clusters). For negatively charged clusters, Δm / Δn saturated between 1 and 1.4 for [NH3] / [H2SO4]>10. Positively charged clusters grew on

  8. Shape memory-based tunable resistivity of polymer composites

    NASA Astrophysics Data System (ADS)

    Luo, Hongsheng; Zhou, Xingdong; Ma, Yuanyuan; Yi, Guobin; Cheng, Xiaoling; Zhu, Yong; Zu, Xihong; Zhang, Nanjun; Huang, Binghao; Yu, Lifang

    2016-02-01

    A conductive composite in bi-layer structure was fabricated by embedding hybrid nanofillers, namely carbon nanotubes (CNTs) and silver nanoparticles (AgNPs), into a shape memory polyurethane (SMPU). The CNT/AgNP-SMPU composites exhibited a novel tunable conductivity which could be facially tailored in wide range via the compositions or a specifically designed thermo-mechanical shape memory programming. The morphologies of the conductive fillers and the composites were investigated by scanning electron microscope (SEM). The mechanical and thermal measurements were performed by tensile tests and differential scanning calorimetry (DSC). By virtue of a specifically explored shape memory programming, the composites were stretched and fixed into different temporary states. The electrical resistivity (Rs) varied accordingly, which was able to be stabilized along with the shape fixing. Theoretical prediction based upon the tunneling model was performed. The Rs-strain curves of the composites with different compositions were well fitted. Furthermore, the relative resistivity and the Gauge factor along with the elongation were calculated. The influence of the compositions on the strain-dependent Rs was disclosed. The findings provided a new avenue to tailor the conductivity of the polymeric nano-composites by combining the composition method and a thermo-mechanical programming, which may greatly benefit the application of intelligent polymers in flexible electronics and sensors fields.

  9. Base pairing and base mis-pairing in nucleic acids

    NASA Technical Reports Server (NTRS)

    Wang, A. H. J.; Rich, A.

    1986-01-01

    In recent years we have learned that DNA is conformationally active. It can exist in a number of different stable conformations including both right-handed and left-handed forms. Using single crystal X-ray diffraction analysis we are able to discover not only additional conformations of the nucleic acids but also different types of hydrogen bonded base-base interactions. Although Watson-Crick base pairings are the predominant type of interaction in double helical DNA, they are not the only types. Recently, we have been able to examine mismatching of guanine-thymine base pairs in left-handed Z-DNA at atomic resolution (1A). A minimum amount of distortion of the sugar phosphate backbone is found in the G x T pairing in which the bases are held together by two hydrogen bonds in the wobble pairing interaction. Because of the high resolution of the analysis we can visualize water molecules which fill in to accommodate the other hydrogen bonding positions in the bases which are not used in the base-base interactions. Studies on other DNA oligomers have revealed that other types of non-Watson-Crick hydrogen bonding interactions can occur. In the structure of a DNA octamer with the sequence d(GCGTACGC) complexed to an antibiotic triostin A, it was found that the two central AT base pairs are held together by Hoogsteen rather than Watson-Crick base pairs. Similarly, the G x C base pairs at the ends are also Hoogsteen rather than Watson-Crick pairing. Hoogsteen base pairs make a modified helix which is distinct from the Watson-Crick double helix.

  10. Electrochemical performance of electroactive poly(amic acid)-Cu2+ composites

    NASA Astrophysics Data System (ADS)

    Yan, Ying; Li, Fangfei; Hanlon, Ashley M.; Berda, Erik B.; Liu, Xincai; Wang, Ce; Chao, Danming

    2017-01-01

    Electroactive poly(amic acid)-Cu2+ (EPAA-Cu) composites on substrates were successfully prepared via nucleophilic polycondensation followed by the use of an immersing method. Analysis of the structure properties of EPAA-Cu composites was performed using scanning electron microscopy (SEM), X-ray photoelectron spectra (XPS) and Fourier-transform infrared spectra (FTIR). A significant current enhancement phenomenon of EPAA-Cu/ITO electrodes was found as evident from cyclic voltammetry (CV) measurements. In addition, Cu2+ ions were incorporated into the composites and had a positive effect on their electrochromic behaviors decreasing their switching times. The anticorrosive performance of EPAA-Cu composites coatings on the carbon steel in 3.5 wt% NaCl solution were also investigated in detail using tafel plots analysis and electrochemical impedance spectroscopy. The anticorrosive ability of these coatings significantly enhanced through the incorporation of Cu2+ ions.

  11. Effect of ocean acidification on the fatty acid composition of a natural plankton community

    NASA Astrophysics Data System (ADS)

    Leu, E.; Daase, M.; Schulz, K. G.; Stuhr, A.; Riebesell, U.

    2013-02-01

    The effect of ocean acidification on the fatty acid composition of a natural plankton community in the Arctic was studied in a large-scale mesocosm experiment, carried out in Kongsfjorden (Svalbard, Norway) at 79° N. Nine mesocosms of ~50 m3 each were exposed to 8 different pCO2 levels (from natural background conditions to ~1420 μatm), yielding pH values (on the total scale) from ~8.3 to 7.5. Inorganic nutrients were added on day 13. The phytoplankton development during this 30-day experiment passed three distinct phases: (1) prior to the addition of inorganic nutrients, (2) first bloom after nutrient addition, and (3) second bloom after nutrient addition. The fatty acid composition of the natural plankton community was analysed and showed, in general, high percentages of polyunsaturated fatty acids (PUFAs): 44-60% of total fatty acids. Positive correlations with pCO2 were found for most PUFAs during phases 2 and/or 3, with the exception of 20:5n3 (eicosapentaenoic acid, EPA), an important diatom marker. These correlations are probably linked to changes in taxonomic composition in response to pCO2. While diatoms (together with prasinophytes and haptophytes) increased during phase 3 mainly in the low and intermediate pCO2 treatments, dinoflagellates were favoured by high CO2 concentrations during the same time period. This is reflected in the development of group-specific fatty acid trophic markers. No indications were found for a generally detrimental effect of ocean acidification on the planktonic food quality in terms of essential fatty acids.

  12. [FATTY ACID COMPOSITION OF PHOSPHOLIPIDS AND ESTERIFIED CHOLESTEROL OF THE BLOOD PLASMA OF RABBIT UNDER ARGININE ACUTE PANCREATITIS].

    PubMed

    Hopanenko, O O; Rivis, J F

    2015-01-01

    The content and fatty acid composition of phospholipids and esterified cholesterol were studied in the blood plasma of rabbits under acute arginine pancreatitis and its correction using linseed oil. It is established that the transport and anti-inflammatory functions of blood plasma deteriorates under acute arginine pancreatitis due to a decrease of the content of polyunsaturated fatty acids in phospholipids. The amount of cholesterol esterified with saturated and monounsaturated fatty acids increases in the blood plasma of rabbits. The concentration of phospholipids and esterified cholesterol is normalized and their fatty acid composition is improved in the lipid composition of the blood plasma of rabbits with acute arginine pancreatitis fed with linseed oil.

  13. Nutritional value of 15 corn gluten meals for growing pigs: chemical composition, energy content and amino acid digestibility.

    PubMed

    Ji, Ying; Zuo, Lei; Wang, Fengli; Li, Defa; Lai, Changhua

    2012-08-01

    The objectives of this study were to determine the chemical composition, energy content and amino acid digestibility for corn gluten meals (CGM) and to develop prediction equations for estimating energy content and amino acid digestibility for growing pigs based on the chemical characteristics of these meals. The 15 CGM tested were obtained from seven Chinese companies. Experiment 1 was conducted to determine the digestible (DE) and metabolisable energy (ME) of the 15 CGM. The 18 growing barrows (38 +/- 4 kg) were assigned to three 6 x 6 Latin square designs. The 15 CGM test diets were formulated to contain 19.20% CGM, which replaced 20% of the energy supplied by corn and crystalline amino acid in the basal diet. Experiment 2 was conducted to determine the apparent (AID) and standardised (SID) ileal digestibility of the crude protein (CP) and amino acids in the 15 CGM using chromic oxide as an inert marker. The 18 growing barrows (25 +/- 2 kg) fitted with a simple T-cannula were assigned to three 6 x 6 Latin square designs. The 15 test diets contained 35% of one of the 15 CGM as the sole source of amino acids in the diet. The results showed a considerable variation in the chemical composition of CGM within and among plants. On dry matter basis, the DE and ME content of the CGM ranged from 18.8 to 21.0 MJ/kg and from 18.0 to 19.9 MJ/kg, respectively. There were no significant differences in the AID and SID for CP, arginine, lysine, glycine and proline among the 15 CGM, however, for all the other amino acids, significant differences were found for their AID and SID. With R2 values exceeding 0.50, the DE of CGM can be predicted accurately from CP and fibre content and ME from starch and fibre content. Suitable prediction equations for SID of methionine were also developed.

  14. Porous calcium phosphate-poly (lactic-co-glycolic) acid composite bone cement: A viable tunable drug delivery system.

    PubMed

    Roy, Abhijit; Jhunjhunwala, Siddharth; Bayer, Emily; Fedorchak, Morgan; Little, Steve R; Kumta, Prashant N

    2016-02-01

    Calcium phosphate based cements (CPCs) are frequently used as bone void fillers for non-load bearing segmental bone defects due to their clinically relevant handling characteristics and ability to promote natural bone growth. Macroporous CPC scaffolds with interconnected pores are preferred for their ability to degrade faster and enable accelerated bone regeneration. Herein, a composite CPC scaffold is developed using newly developed resorbable calcium phosphate cement (ReCaPP) formulation containing degradable microspheres of bio-compatible poly (lactic-co-glycolic acid) (PLGA) serving as porogen. The present study is aimed at characterizing the effect of in-vitro degradation of PLGA microspheres on the physical, chemical and structural characteristics of the composite cements. The porosity measurements results reveal the formation of highly interconnected macroporous scaffolds after degradation of PLGA microspheres. The in-vitro characterizations also suggest that the degradation by products of PLGA reduces the pH of the local environment thereby increasing the dissolution rate of the cement. In addition, the in-vitro vancomycin release from the composite CPC scaffold suggests that the drug association with the composite scaffolds can be tuned to achieve control release kinetics. Further, the study demonstrates control release lasting for longer than 10weeks from the composite cements in which vancomycin is encapsulated in PLGA microspheres.

  15. New Bioactive Composite Nanomaterials Based on Fullerene Derivatives

    NASA Astrophysics Data System (ADS)

    Soldatov, A. G.; Shpilevsky, E. M.; Goranov, V. A.; Pushkarchuk, A. L.; Khrutchinsky, A. A.; Nizovtsev, A. P.; Kilin, S. Ya.

    2013-05-01

    Formation conditions of the fullerene based composite material with a homogeneous distribution of bioactive particles are defined. An influence of C60(FeCp2)2 particle size on the proliferative activity of stem cells is discussed.

  16. Key volatile aroma compounds of lactic acid fermented malt based beverages - impact of lactic acid bacteria strains.

    PubMed

    Nsogning Dongmo, Sorelle; Sacher, Bertram; Kollmannsberger, Hubert; Becker, Thomas

    2017-08-15

    This study aims to define the aroma composition and key aroma compounds of barley malt wort beverages produced from fermentation using six lactic acid bacteria (LAB) strains. Gas chromatography mass spectrometry-olfactometry and flame ionization detection was employed; key aroma compounds were determined by means of aroma extract dilution analysis. Fifty-six detected volatile compounds were similar among beverages. However, significant differences were observed in the concentration of individual compounds. Key aroma compounds (flavor dilution (FD) factors ≥16) were β-damascenone, furaneol, phenylacetic acid, 2-phenylethanol, 4-vinylguaiacol, sotolon, methional, vanillin, acetic acid, nor-furaneol, guaiacol and ethyl 2-methylbutanoate. Furthermore, acetaldehyde had the greatest odor activity value of up to 4266. Sensory analyses revealed large differences in the flavor profile. Beverage from L. plantarum Lp. 758 showed the highest FD factors in key aroma compounds and was correlated to fruity flavors. Therefore, we suggest that suitable LAB strain selection may improve the flavor of malt based beverages.

  17. Fatty acids composition of Caenorhabditis elegans using accurate mass GCMS-QTOF.

    PubMed

    Henry, Parise; Owopetu, Olufunmilayo; Adisa, Demilade; Nguyen, Thao; Anthony, Kevin; Ijoni-Animadu, David; Jamadar, Sakha; Abdel-Rahman, Fawzia; Saleh, Mahmoud A

    2016-08-02

    The free living nematode Caenorhabditis elegans is a proven model organism for lipid metabolism research. Total lipids of C. elegans were extracted using chloroform and methanol in 2:1 ratio (v/v). Fatty acids composition of the extracted total lipids was converted to their corresponding fatty acids methyl esters (FAMEs) and analyzed by gas chromatography/accurate mass quadrupole time of flight mass spectrometry using both electron ionization and chemical ionization techniques. Twenty-eight fatty acids consisting of 12 to 22 carbon atoms were identified, 65% of them were unsaturated. Fatty acids containing 12 to17 carbons were mostly saturated with stearic acid (18:0) as the major constituent. Several branched-chain fatty acids were identified. Methyl-14-methylhexadecanoate (iso- 17:0) was the major identified branched fatty acid. This is the first report to detect the intact molecular parent ions of the identified fatty acids in C. elegans using chemical ionization compared to electron ionization which produced fragmentations of the FAMEs.

  18. Amino acid composition and crude protein values of some Cyanobacteria from Çanakkale (Turkey).

    PubMed

    Akgül, Rıza; Kızılkaya, Bayram; Akgül, Füsun; Erduğan, Hüseyin

    2015-09-01

    Cyanobacteria (blue-green algae) form an important component of integrated nutrient managements in agriculture and are exploited in commercial biotechnological ventures. In this study, Rivularia bullata (Poir) Berkeley ex Bornet & Flahault, Nostocs pongiaeforme C. Agardh ex Bornet & Flahault were researched for their amino acid composition and crude protein values. R. bullata was collected from coastal zones of the Gulf of Saros and N. spongiaeforme from the Ayazma Stream. The levels of amino acids were measured in algae samples using EZ: fast kits (EZ: fast GC/FID Protein Hydrolysate Amino Acid Kit) by gas chromatography. The crude proteins of samples were determined by the Kjeldahl method and were calculated using a nitrogen conversion factor of 6.25. Thirty-two amino acids were investigated, for N. spongiaeforme eight free essential amino acids (EAA), eight free non-essential amino acids (NEAA) and eleven other amino acids (OAA); for R. bullata eight EAA, eight NEAA and eight OAA were detected. Aspartic acid is the major constituent for both species. The total protein percents were determined for N. spongiaeforme as % 19.83 and for R. bullata as % 6.15. When considering the increasing world population and reducing natural products; Cyanobacteria will benew feed sources for all living.

  19. Composition-based prediction of dielectric properties of foods.

    PubMed

    Sun, E; Datta, A; Lobo, S

    1995-01-01

    Prediction of accurate dielectric property data from fundamental principles for systems as complex as foods has not been possible. Simple prediction models based on easily measurable composition data can serve many useful purposes. Literature dielectric data on foods and their composition were statistically correlated. Dielectric data on salt solutions were measured to explain some of the results. When composition data were not available, standard handbook compositions were used. Inclusion of all types of foods (meats, fruits, and vegetables) inhibited any useful correlation with composition. Based on a smaller data set of meats, both dielectric constant and loss increased with water and salt content. Dielectric constant generally decreased with temperature whereas dielectric loss decreased with temperature at lower salt concentrations and increased with temperature at higher salt concentrations.

  20. Subcutaneous fatty acid composition of steers finished as weanlings or yearlings with and without growth promotants

    PubMed Central

    2013-01-01

    Background The current study evaluated the subcutaneous fatty acid (FA) composition of calf- and yearling-fed steers with or without growth promoting implants. Crossbred steers (n = 112; 267 ± 5.0 kg) of the same contemporary group were allocated to one of four production system and implant strategy based treatments in a completely randomized design with a 2 × 2 factorial arrangement of treatments. Results There were no interactions (P > 0.05) between production systems and growth promoting implants for the total and individual subcutaneous FA. Yearling as opposed to calf finishing reduced (P < 0.05) subcutaneous proportions of C20:3n-6, trans (t)12-18:1, C14:0, several minor cis-monounsaturated FA (c-MUFA; c9-14:1, c11-16:1, c11-18:1, c12-18:1, c13-18:1, c9-20:1 and c11-20:1), and increased (P < 0 .05) subcutaneous proportions of t11c15-18:2, total and individual branched-chain FA. Subcutaneous fat from steers implanted with growth promotants had higher (P < 0.05) proportions of total polyunsaturated FA (PUFA), total n-6 PUFA, C18:2n-6 and individual t-18:1 isomers (t6 to t10) compared to non-implanted steers. Conclusions Overall, current findings show that production systems and growth promotants led to only minor differences in subcutaneous FA composition of beef steers. PMID:24188642

  1. Preparation and characterization of dry method esterified starch/polylactic acid composite materials.

    PubMed

    Zuo, Yingfeng; Gu, Jiyou; Yang, Long; Qiao, Zhibang; Tan, Haiyan; Zhang, Yanhua

    2014-03-01

    Corn starch and maleic anhydride were synthesized from a maleic anhydride esterified starch by dry method. Fourier transform infrared spectroscopy (FTIR) was used for the qualitative analysis of the esterified starches. The reaction efficiency of dry method esterified starch reached 92.34%. The dry method esterified starch was blended with polylactic acid (PLA), and the mixture was melted and extruded to produce the esterified starch/polylactic acid (ES/PLA) composites. The degree of crystallinity of the ES/PLA was lower than that of the NS/PLA, indicating that the relative dependence between these two components of starch and polylactic acid was enhanced. Scanning electron microscopy (SEM) indicated that the dry method esterified starch increased the two-phase interface compatibility of the composites, thereby improving the tensile strength, bending strength, and elongation at break of the ES/PLA composite. The introduction of a hydrophobic ester bond and increase in interface compatibility led to an increase in ES/PLA water resistance. Melt index determination results showed that starch esterification modification had improved the melt flow properties of starch/PLA composite material. Strain scanning also showed that the compatibility of ES/PLA was increased. While frequency scanning showed that the storage modulus and complex viscosity of ES/PLA was less than that of NS/PLA.

  2. Changes in fatty acid composition in sardines (Sardinops melanosticta) with cooking and refrigerated storage.

    PubMed

    Yamamoto, Y; Imose, K

    1989-02-01

    The influence of cooking and later storage in a refrigerator for 7 days on the fatty acid composition of lipids in sardines (Sardinops melanosticta) was studied. The total lipid and triacylglycerol (TG) levels did not change and the phospholipid (PL) level decreased somewhat with cooking or during storage. The fatty acid composition of the total lipids and TG fractions was little changed and that in the PL fractions was somewhat changed by the cooking. The composition of the polyunsaturated fatty acids (PUFA) in lipids of sardine precooked at 100 or 170 degrees C for 30 min changed from 42.7 to 38.3 or 33.5%, respectively, for total lipids and from 51.5 to 38.4 or 37.6%, respectively, for PL fractions during storage. The fatty acids in lipids from the ordinary meat of sardine was stable and those in the dark meat were extremely unstable during storage after cooking. We concluded that the PUFA in the lipids of sardines were stable to cooking, but unstable to oxidation during storage in a refrigerator. The PUFA of lipids in the dark meat of sardine were extremely unstable to oxidation.

  3. Hydrocarbon-based polymer electrolyte cerium composite membranes for improved proton exchange membrane fuel cell durability

    NASA Astrophysics Data System (ADS)

    Lee, Hyejin; Han, Myungseong; Choi, Young-Woo; Bae, Byungchan

    2015-11-01

    Hydrocarbon-based cerium composite membranes were prepared for proton exchange membrane fuel cell applications to increase oxidative stability. Different amounts of cerium ions were impregnated in sulfonated poly(arylene ether sulfone) (SPES) membranes and their physicochemical properties were investigated according to the cerium content. Field-emission scanning electron microscopy and inductively coupled plasma analyses confirmed the presence of cerium ions in the composite membranes and 1H NMR indicated the successful coordination of sulfonic acid groups with the metal ions. Increasing amounts of cerium ions resulted in decreases in the proton conductivity and water uptake, but enhanced oxidative stability. The oxidative stability of the composite membranes was proven via a hydrogen peroxide exposure experiment which mimicked fuel cell operating conditions. In addition, more than 2200 h was achieved with the composite membrane under in situ accelerated open circuit voltage (OCV) durability testing (DOE protocol), whereas the corresponding pristine SPES membrane attained only 670 h.

  4. Effect of replacing dietary menhaden oil with pollock or soybean oil on muscle fatty acid composition and growth performance of juvenile pacific threadfin (polyactylus sexfilis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study compared the nutritional values of menhaden fish oil and pollock oil; and studied the potential of replacing dietary pollock oil by soybean oil based on the effect of pollock oil on growth performance, body composition, and muscle fatty acid profiles of juvenile Pacific threadfin. All te...

  5. Effect of phytic acid and microbial phytase on the flow and amino acid composition of endogenous protein at the terminal ileum of growing broiler chickens.

    PubMed

    Cowieson, A J; Ravindran, V

    2007-10-01

    The effects of phytic acid and microbial phytase on the flow and composition of endogenous protein at the terminal ileum of broiler chickens were investigated using the peptide alimentation method. Phytic acid (fed as the sodium salt) was included in a synthetic diet at 8.5, 11.5 and 14.5 g/kg (or 2.4, 3.2 and 4.0 g/kg phytate-phosphorus) and each diet was fed without or with an Escherichia coli-derived microbial phytase at 500 phytase units/kg diet. A control containing no phytate was fed as a comparison to estimate basal endogenous flows. Ingestion of phytic acid increased (P < 0.05) the flow of endogenous amino acids and N by an average of 47 % at the lowest phytic acid concentration and 87 % at the highest. The addition of microbial phytase reduced (P < 0.05) the inimical effects of phytic acid on endogenous amino acid flow at all dietary phytic acid levels. The composition of endogenous protein was also influenced (P < 0.10-0.001) by increasing phytic acid concentrations and phytase addition. The effects of phytic acid and phytase on endogenous flow and composition of endogenous protein, however, varied depending on the amino acid. It is concluded that the effects of phytase on amino acid digestibility may be mediated, in part, through a route of reduced endogenous loss.

  6. Relationship between hydroxycinnamic acid content, lignin composition and digestibility of maize silages in sheep.

    PubMed

    Novo-Uzal, Esther; Taboada, Alfredo; Rivera, Antonio; Flores, Gonzalo; Barceló, Alfonso Ros; Masa, Antón; Pomar, Federico

    2011-04-01

    Cell wall-bound hydroxycinnamic acids and the composition of lignin were studied in relation to the digestibility of a collection of 91 maize silages in wethers. Total lignin and guaiacyl content showed the highest correlation coefficients with digestibility. Using the above-mentioned chemical parameters, eight equations were also developed to predict digestibility. The prediction of organic matter digestibility produced a high adjusted R2 value (0.487) using total lignin, guaiacyl, esterified ferulic acid and esterified p-coumaric acid content as predictors. The prediction of in vivo dry matter digestibility produced a higher adjusted R2 value (0.516) using the same variables as predictors. Cell wall digestibility depends on a multiplicity of factors and it is not possible to attribute a causal effect on in vivo digestibility to any single factor. However, total lignin, guaiacyl and p-coumaric acid content emerge as good predictors of digestibility.

  7. Enhancement effect of ethanol on lipid and fatty acid accumulation and composition of Scenedesmus sp.

    PubMed

    Wu, Chengchen; Wang, Wei; Yue, Long; Yang, Zhen; Fu, Qiuguo; Ye, Qingfu

    2013-07-01

    The effects of ethanol concentration gradients along with varied cultivation times on lipid and fatty acid accumulation and composition of Scenedesmus sp. were studied. The maximum increment of algal density, lipid productivity, lipid content and fatty acid content were 6.61, 11.75, 1.34 and 3.14 times higher than the control group under 12h photoperiod. Algal light deprivation inhibited ethanol positive effects on algal growth and lipid biomass. The cumulative quantity of C16:0 and C18:0 decreased correspondingly with the increase of ethanol concentrations and cultivation times. Besides, unsaturated fatty acids appeared early in algal cells and increased 57.02% in maximum. However, only 2.27% (14)C was transferred from ethanol to fatty acids. The results indicated that adding proper amount of ethanol in algal culture medium was beneficial to biodiesel feedstock production and biodiesel properties.

  8. Eggshell composition of squamate reptiles: relationship between eggshell permeability and amino acid distribution.

    PubMed

    Sexton, Owen J; Bramble, Judith E; Heisler, I Lorraine; Phillips, Christopher A; Cox, David L

    2005-10-01

    Most snakes and lizards produce eggs with flexible shells that interact with the environment to maintain water balance. Geckos produce rigid eggshells that are independent of an external source of water and can be oviposited in more open, dryer locations. In this study, we analyzed and compared the amino acid composition of 24 lizard species, six snake species, and four outgroups (including avian and reptilian elastin and chicken eggshell). Rigid Gecko eggshells had significantly lower levels of seven of the 17 amino acids evaluated. Multivariate analysis showed that proline was the most important amino acid in distinguishing between these two groups of eggshells, occurring at significantly higher levels in flexible eggshells. High levels of proline have also been observed in the eggshells of other species. Proline and other amino acids are associated with the alleviation of water and salt stress in plants.

  9. Chemical composition and amino acid profiles of goose muscles from native Polish breeds.

    PubMed

    Okruszek, A; Woloszyn, J; Haraf, G; Orkusz, A; Werenska, M

    2013-04-01

    The aim of the study was to compare the chemical and amino acid composition of breast (pectoralis major) and thigh (biceps femoris) muscles in 17-wk-old geese from 2 Polish conservative flocks: Rypińska (Ry, n = 20) and Garbonosa (Ga, n = 20). The geese were fed ad libitum during the experimental period on the same complete feed. Genotypes affected the moisture and fat content of breast and thigh meat. The Ga geese were characterized by higher moisture as well as lower fat lipid content compared with the Ry breast and thigh muscles. The amino acid proportions of meat proteins depended on the goose flock and type of muscles, where significant differences were found. The proteins of Ga breast muscles contained more glutamic acid, glycine, lysine, tryptophan, histidine, and methionine, and less aspartic acid, proline, serine, leucine, valine, phenyloalanine, tyrosine, and threonine than the Ry geese (P ≤ 0.05). The proteins of Ry thigh muscles were characterized by higher content of proline, serine, and essential amino acids (without lysine and methionine) and lower glutamic and asparagine acid, alanine, and glycine compared with the Ga flock. According to the Food and Agriculture Organization of the United Nations/World Health Organization (1991) standard, tryptophan was the amino acid limiting the nutritional value of meat proteins of Ry breast muscles (amino acid score for tryptophan = 90%). Except for tryptophan, the meat proteins of the investigated raw materials contained more essential amino acids than the standard. The total content of essential amino acids for all investigated muscles was also higher (52.51 to 55.54%) than the standard (33.90%). It is evident that muscle protein from both flocks of geese have been characterized by high nutritional value. The values of the essential amino acid index of breast muscle proteins were similar in both flocks.

  10. Adsorption of Acid Red 57 from aqueous solutions onto polyacrylonitrile/activated carbon composite.

    PubMed

    El-Bindary, Ashraf A; Diab, Mostafa A; Hussien, Mostafa A; El-Sonbati, Adel Z; Eessa, Ahmed M

    2014-04-24

    The adsorption of Acid Red 57 (AR57) onto Polyacrylonitrile/activated carbon (PAN/AC) composite was investigated in aqueous solution in a batch system with respect to contact time, pH and temperature. Physical characteristics of (PAN/AC) composite such as fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were obtained. Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The activation energy of adsorption was also evaluated for the adsorption of AR57 onto (PAN/AC) composite. The pseudo-first-order and pseudo-second-order kinetic models were used to describe the kinetic data. The dynamic data fitted the pseudo-second-order kinetic model well. The activation energy, change of free energy, enthalpy and entropy of adsorption were also evaluated for the adsorption of AR57 onto (PAN/AC) composite. The thermodynamics of the adsorption indicated spontaneous and exothermic nature of the process. The results indicate that (PAN/AC) composite could be employed as low-cost material for the removal of acid dyes from textile effluents.

  11. A novel basalt fiber-reinforced polylactic acid composite for hard tissue repair.

    PubMed

    Chen, Xi; Li, Yan; Gu, Ning

    2010-08-01

    A basalt fiber (BF) was, for the first time, introduced into a poly(l-lactic acid) (PLLA) matrix as innovative reinforcement to fabricate composite materials for hard tissue repair. Firstly, BF/PLLA composites and pure PLLA were produced by the methods of solution blending and freeze drying. The results showed that basalt fibers can be uniformly dispersed in the PLLA matrix and significantly improve the mechanical properties and hydrophilicity of the PLLA matrix. The presence of basalt fibers may retard the polymer degradation rate and neutralize the acid degradation from PLLA. Osteoblasts were cultured in vitro to evaluate the cytocompatibility of the composite. An MTT assay revealed that osteoblasts proliferated well for 7 days and there was little difference found in their viability on both PLLA and BF/PLLA films, which was consistent with the alkaline phosphatase (ALP) activity results. A fluorescent staining observation showed that osteoblasts grew well on the composites. SEM images displayed that osteoblasts tended to grow along the fiber axis. The formation of mineralized nodules was observed on the films by Alizarin red S staining. These results suggest that the presence of basalt fibers does not noticeably affect osteoblastic behavior and the designed composites are osteoblast compatible. It is concluded that basalt fibers, as reinforcing fibers, may have promising applications in hard tissue repair.

  12. Formation of titanium phosphate composites during phosphoric acid decomposition of natural sphene

    NASA Astrophysics Data System (ADS)

    Maslova, Marina V.; Rusanova, Daniela; Naydenov, Valeri; Antzutkin, Oleg N.; Gerasimova, Lidia G.

    2008-12-01

    Decomposition of mineral sphene, CaTiOSiO 4, by H 3PO 4 is investigated in detail. During the dissolution process, simultaneous calcium leaching and formation of titanium phosphate (TiP) take place. The main product of decomposition is a solid titanium phosphate-silica composite. The XRD, solid-sate NMR, IR, TGA, SEM and BET data were used to identify and characterize the composite as a mixture of crystalline Ti(HPO 4) 2·H 2O and silica. When 80% phosphoric acid is used the decomposition degree is higher than 98% and calcium is completely transferred into the liquid phase. Formation of Ti(HPO 4) 2·H 2O proceeds via formation of meta-stable titanium phosphate phases, Ti(H 2PO 4)(PO 4)·2H 2O and Ti(H 2PO 4)(PO 4). The sorption affinities of TiP composites were examined in relation to caesium and strontium ions. A decrease of H 3PO 4 concentration leads to formation of composites with greater sorption properties. The maximum sorption capacity of TiP is observed when 60% H 3PO 4 is used in sphene decomposition. The work demonstrates a valuable option within the Ti(HPO 4) 2·H 2O-SiO 2 composite synthesis scheme, to use phosphoric acid flows for isolation of CaHPO 4·2H 2O fertilizer.

  13. The influence of dietary docosahexaenoic acid and arachidonic acid on central nervous system polyunsaturated fatty acid composition.

    PubMed

    Brenna, J Thomas; Diau, Guan-Yeu

    2007-01-01

    Numerous studies on perinatal long-chain polyunsaturated fatty acid nutrition have clarified the influence of dietary docosahexaenoic acid (DHA) and arachidonic acid (ARA) on central nervous system PUFA concentrations. In humans, omnivorous primates, and piglets, DHA and ARA plasma and red blood cells concentrations rise with dietary preformed DHA and ARA. Brain and retina DHA are responsive to diet while ARA is not. DHA is at highest concentration in cells and tissues associated with high energy consumption, consistent with high DHA levels in mitochondria and synaptosomes. DHA is a substrate for docosanoids, signaling compounds of intense current interest. The high concentration in tissues with high rates of oxidative metabolism may be explained by a critical role related to oxidative metabolism.

  14. The Influence of Dietary Docosahexaenoic Acid and Arachidonic Acid on Central Nervous System Polyunsaturated Fatty Acid Composition

    PubMed Central

    Brenna, J. Thomas; Diau, Guan-Yeu

    2007-01-01

    Numerous studies on perinatal long chain polyunsaturated fatty acid nutrition have clarified the influence of dietary docosahexaenoic acid (DHA) and arachidonic acid (ARA) on central nervous system PUFA concentrations. In humans, omnivorous primates, and piglets, DHA and ARA plasma and red blood cells concentrations rise with dietary preformed DHA and ARA. Brain and retina DHA are responsive to diet while ARA is not. DHA is at highest concentration cells and tissues associated with high energy consumption, consistent with high DHA levels in mitochondria and synaptosomes. DHA is a substrate for docosanoids, signaling compounds of intense current interest. The high concentration in tissues with high rates of oxidative metabolism may be explained by a critical role related to oxidative metabolism. PMID:18023566

  15. Comparative study of the fatty acid composition of sponges of the genus Ircinia. Identification of the new 23-methyl-5,9-tetracosadienoic acid.

    PubMed

    Carballeira, N M; Shalabi, F; Cruz, C; Rodriguez, J; Rodriguez, E

    1991-01-01

    1. The phospholipid fatty acid compositions of the sponges Ircinia strobilina, Ircinia felix, Ircinia campana, Ircinia sp., Spongia tubulifera and Dysidea etherea were studied, revealing the presence, besides other common fatty acids, of considerable amounts (2-5%) of the novel 23-methyl-5,9-tetracosadienoic acid (1). 2. The demospongic acids 5,9-tetracosadienoic acid, 23-methyl-5,9-tetracosadienoic acid (1), and 5,9-pentacosadienoic acid, were particularly abundant in sponges of the genus Ircinia, in contrast to the most common 5,9-hexacosadienoic acid found in other species. These findings are discussed in terms of the taxonomy of the Dictyoceratida. 3. The complete characterization of the novel phospholipid fatty acid 23-methyl-5,9-tetracosadienoic acid (1) is presented.