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Sample records for acid insoluble material

  1. Conversion and Extraction of Insoluble Organic Materials in Meteorites

    NASA Technical Reports Server (NTRS)

    Locke, Darren R.; Burton, Aaron S.; Niles, Paul B.

    2016-01-01

    We endeavor to develop and implement methods in our laboratory to convert and extract insoluble organic materials (IOM) from low car-bon bearing meteorites (such as ordinary chondrites) and Precambrian terrestrial rocks for the purpose of determining IOM structure and prebiotic chemistries preserved in these types of samples. The general scheme of converting and extracting IOM in samples is summarized in Figure 1. First, powdered samples are solvent extracted in a micro-Soxhlet apparatus multiple times using solvents ranging from non-polar to polar (hexane - non-polar, dichloromethane - non-polar to polar, methanol - polar protic, and acetonitrile - polar aprotic). Second, solid residue from solvent extractions is processed using strong acids, hydrochloric and hydrofluoric, to dissolve minerals and isolate IOM. Third, the isolated IOM is subjected to both thermal (pyrolysis) and chemical (oxidation) degradation to release compounds from the macromolecular material. Finally, products from oxidation and pyrolysis are analyzed by gas chromatography - mass spectrometry (GCMS). We are working toward an integrated method and analysis scheme that will allow us to determine prebiotic chemistries in ordinary chondrites and Precambrian terrestrial rocks. Powerful techniques that we are including are stepwise, flash, and gradual pyrolysis and ruthenium tetroxide oxidation. More details of the integrated scheme will be presented.

  2. XPS and STEM studies of Allende acid insoluble residues

    NASA Technical Reports Server (NTRS)

    Housley, R. M.; Clarke, D. R.

    1980-01-01

    Data on Allende acid residues obtained both before and after etching with hot HNO3 are presented. X-ray photoelectron spectra show predominantly carbonaceous material plus Fe-deficient chromite in both cases. The HNO3 oxidizes the carbonaceous material to some extent. The small chromites in these residues have a wide range of compositions somewhat paralleling those observed in larger Allende chromites and in Murchison chromites, especially in the high Al contents; however, they are deficient in divalent cations, which makes them metastable and indicates that they must have formed at relatively low temperatures. It is suggested that they formed by precipitation of Cr(3+) and Fe(3+) from olivine at low temperature or during rapid cooling.

  3. Hydroxylamine hydrochloride-acetic acid-soluble and -insoluble fractions of pelagic sediment: Readsorption revisited

    USGS Publications Warehouse

    Piper, D.Z.; Wandless, G.A.

    1992-01-01

    The extraction of the rare earth elements (REE) from deep-ocean pelagic sediment, using hydroxylamine hydrochloride-acetic acid, leads to the separation of approximately 70% of the bulk REE content into the soluble fraction and 30% into the insoluble fraction. The REE pattern of the soluble fraction, i.e., the content of REE normalized to average shale on an element-by-element basis and plotted against atomic number, resembles the pattern for seawater, whereas the pattern, as well as the absolute concentrations, in the insoluble fraction resembles the North American shale composite. These results preclude significant readsorption of the REE by the insoluble phases during the leaching procedure.

  4. DIRECT VERSES SEQUENTIAL ANALYSIS OF ACID-DETERGENT INSOLUBLE NITROGEN IN FORAGE LEGUME HAYS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acid-detergent insoluble nitrogen (ADIN) is thought to represent nitrogen that is not degraded during ruminal and post-ruminal digestion of forages by cattle. Forage ADIN can be determined following direct acid detergent extraction or following sequential extraction with neutral and acid detergents....

  5. STRUCTURAL IDENTIFICATION OF DEHYDROTRIFERULIC AND DEHYDROTETRAFERULIC ACIDS ISOLATED FROM INSOLUBLE MAIZE FIBER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Two new dehydrotriferulic acids and two dehydrotetraferulic acids were isolated from saponified maize bran insoluble fiber using size exclusion chromatography on BioBeads S-X3 followed by Sephadex LH-20 chromatography and semi-preparative Phenyl-Hexyl-RP-HPLC. Based on UV-spectroscopy, mass spectros...

  6. Classification and morphometric quantitation of insoluble materials from the lungs of patients with alveolar proteinosis.

    PubMed Central

    Gilmore, L. B.; Talley, F. A.; Hook, G. E.

    1988-01-01

    Insoluble materials isolated by bronchoalveolar lavage from the lungs of four patients with alveolar proteinosis were examined under the electron microscope, categorized according to ultrastructural criteria, and quantitated using morphometric procedures. The major component of the insoluble accumulations was the tubular myelinlike multilamellated structure that accounted for 42.6 +/- 12.4% of the total volume of insoluble material. These structures resembled tubular myelin as found in normal human lungs, consisting of lipid bilayer membranes separated by amorphous proteinaceous material; however, tubular myelinlike multilamellated structures lacked the intersecting membranes of normal tubular myelin. The distance between membranes varied from 150 to 300 A and this was similar to that found in tubular myelin from normal human lungs. Fused-membrane structures that were multilamellated but were without intervening amorphous lamellae accounted for 2.7 +/- 0.6% of the total volume of insoluble material. Crystals, identified by the presence of adhering materials, were present only in small amounts, accounting for only 0.07 +/- 0.03% of the volume of insoluble material. Neither fused-membrane structures nor crystals are present in lavage effluents from the lungs of normal humans. Membranous vesicles and electron-dense bodies, which resembled cell debris, together accounted for 21.2 +/- 10.1% of the total volume of insoluble material. Constituents of the pulmonary extracellular lining of normal human lungs such as secreted lamellar bodies and tubular myelin were minor components, together accounting for only 2.2 +/- 3.2% of the total volume of insoluble material. Amorphous material and miscellaneous structures accounted for 31.4 +/- 5.0% of the volume of insoluble material. Cellular disintegration and extracellular formation of unusual tubular myelinlike multilamellated structures appear to be major processes leading to the accumulation of insoluble materials in the

  7. Organic acids as cloud condensation nuclei: Laboratory studies of highly soluble and insoluble species

    NASA Astrophysics Data System (ADS)

    Pradeep Kumar, P.; Broekhuizen, K.; Abbatt, J. P. D.

    2003-05-01

    The ability of sub-micron-sized organic acid particles to act as cloud condensation nuclei (CCN) has been examined at room temperature using a newly constructed continuous-flow, thermal-gradient diffusion chamber (TGDC). The organic acids studied were: oxalic, malonic, glutaric, oleic and stearic. The CCN properties of the highly soluble acids - oxalic, malonic and glutaric - match very closely Köhler theory predictions which assume full dissolution of the dry particle and a surface tension of the growing droplet equal to that of water. In particular, for supersaturations between 0.3 and 0.6, agreement between the dry particle diameter which gives 50% activation and that calculated from Köhler theory is to within 3nm on average. In the course of the experiments, considerable instability of glutaric acid particles was observed as a function of time and there is evidence that they fragment to some degree to smaller particles. Stearic acid and oleic acid, which are both highly insoluble in water, did not activate at supersaturations of 0.6% with dry diameters up to 140nm. Finally, to validate the performance of the TGDC, we present results for the activation of ammonium sulfate particles that demonstrate good agreement with Köhler theory if solution non-ideality is considered. Our findings support earlier studies in the literature that showed highly soluble organics to be CCN active but insoluble species to be largely inactive.

  8. Removal of metals and water-insoluble materials from desalter emulsions

    SciTech Connect

    Goyal, S.K.; Mosby, J.F.; Treadman, J.E. II.

    1993-06-15

    A process for removing metals and insoluble materials from crude oil is described comprising the steps of: blending crude oil with water and desalting chemicals; charging the oil blend to a desalting chamber and passing it through an electrical field whereby agglomeration of suspended insoluble materials occurs and layers of clean oil, brine and oil-brine interface emulsion are formed; withdrawing the oil and brine; measuring the volume of the emulsion layer; withdrawing a portion of the emulsion layer; blending the withdrawn emulsion with up to 2 volumes of aromatic-rich hydrocarbon containing at least 20% aromatics by volume; maintaining the blend at a temperature of 100 to 300 F and a positive pressure; and subjecting the blend to a force of at least about 500 g, whereby oil free of at least 90% of suspended particulates and water results.

  9. The Insoluble Carbonaceous Material of CM Chondrites as Possible Source of Discrete Organics During the Asteroidal Aqueous Phase

    NASA Technical Reports Server (NTRS)

    Yabuta, H.; Williams, L.; Cody, G.; Pizzarello, S.

    2005-01-01

    The larger portion of the organic carbon in carbonaceous chondrites (CC) is present as a complex and heterogeneous macromolecular material that is insoluble in acids and most solvents (IOM). So far, it has been analyzed only as a whole by microscopy (TEM) and spectroscopy (IR, NMR, EPR), which have offered and overview of its chemical nature, bonding, and functional group composition. Chemical or pyrolytic decomposition has also been used in combination with GC-MS to identify individual compounds released by these processes. Their value in the recognition of the original IOM structure resides in the ability to properly interpret the decomposition pathways for any given process. We report here a preliminary study of IOM from the Murray meteorite that combines both the analytical approaches described above, under conditions that would realistically model the IOM hydrothermal exposure in the meteorite parent body. The aim is to document the possible release of water and solvent soluble organics, determine possible changes in NMR spectral features, and ascertain, by extension, the effect of this loss on the frame of the IOM residue. Additional information is included in the original extended abstract.

  10. Using acid insoluble ash marker ratios (diet:digesta) to predict digestibility of wheat and barley metabolizable energy and nitrogen retention in broiler chicks.

    PubMed

    Scott, T A; Hall, J W

    1998-05-01

    Routine bioassay measurements of AME or N retention of broiler diets require measurements of gross energy (GE) or N and an acid insoluble ash marker in diet, excreta, or ileal digesta. These measurements of GE and N are time-consuming and expensive in comparison to measurements of added or natural occurring levels of acid insoluble ash. Data from bioassay measurements of AME and N retention of 138 wheat and 97 barley samples (with or without enzyme) were used to develop prediction equations relying on measurements of one that uses acid insoluble ash of diet, excreta or ileal digesta and GE and N of diet only; and a second equation using only acid insoluble ash of diet, excreta, or ileal digesta. The prediction equations demonstrate that part of or all of routine bomb calorimetry measurements for GE used to determine AME of wheat- or barley-based diets could be eliminated if a prediction error of 80 kcal/kg ME or less were acceptable. The prediction of N retention as compared to AME, based in part or totally on acid insoluble ash measurements, was less accurate; the prediction errors were equal to 2.3 and 6.5% for wheat- and barley-based diets, respectively. Ongoing research to improve the determination (speed, ease, and accuracy) of acid insoluble ash could provide a useful method to assess feeding value of ingredients and commercial poultry diets. PMID:9603354

  11. Trace metal occurrences in acid-insoluble residues of the Ordovician Galena Group, southeastern Minnesota

    SciTech Connect

    Lively, R.S.; Mossler, J.H.; Morey, G.B. ); Hauck, S.A. . Natural Resources Research Inst.)

    1993-03-01

    Regional geochemical, studies on insoluble residues from Paleozoic carbonate rocks have become an integral part of the search for new Upper Mississippi Valley-type mineral deposits in the northern Midcontinent. The authors have extended these studies to southeastern Minnesota, an area well to the north of known lead-zinc deposits of commercial size and grade. In this region, a thin sequence of Upper Cambrian to Middle Ordovician strata unconformably overlies a complex Precambrian basement. More than 500 samples of limestone and dolomite from 40 drill holes and outcrops were analyzed for 29 related trace elements. Preliminary interpretations are based on the analysis of 380 samples of the Ordovician Galena Group from 37 localities. Results indicate that anomalous concentrations of Pb, Cu, zn, As, Cd, and Ni are confined to the southern half of the Galena subgroup area and extend less than 30 miles north of the Iowa border. The anomalous areas, as well as saddles between the, have a distinct northwest trend, coincident with structural features previously recognized in the Precambrian basement. The spatial relationships of the anomalies and the lack of direct correlation imply deposition from fluids moving north out of the main lead-zinc district along structural pathways. The lack of significant anomalies in the northern part of the subcrop area implies northwest weakening of the forces driving the metal-bearing fluids, as well as a decrease over distance in the absolute metal content of the migrating fluids.

  12. Production of furfural from xylose, water-insoluble hemicelluloses and water-soluble fraction of corncob via a tin-loaded montmorillonite solid acid catalyst.

    PubMed

    Li, Huiling; Ren, Junli; Zhong, Linjie; Sun, Runcang; Liang, Lei

    2015-01-01

    The conversion of xylose, water-insoluble hemicelluloses (WIH) and water-soluble fraction (WSF) of corncob to furfural was performed using montmorillonite with tin ions (Sn-MMT) containing double acid sites as a solid acid catalyst. The co-existence of Lewis acids and Brønsted acids in Sn-MMT was shown to improve the furfural yield and selectivity. 76.79% furfural yield and 82.45% furfural selectivity were obtained from xylose using Sn-MMT as a catalyst in a biphasic system with 2-s-butylphenol (SBP) as the organic extracting layer and dimethyl sulfoxide (DMSO) as the co-solvent in contact with an aqueous phase saturated with NaCl (SBP/NaCl-DMSO) at 180°C for 30min. Furthermore, Sn-MMT also demonstrated the excellent catalytic performance in the conversion of pentose-rich materials of corncob and 39.56% and 54.15% furfural yields can be directly obtained from WIH and WSF in the SBP/NaCl-DMSO system, respectively. PMID:25461009

  13. Glucansucrases from lactic acid bacteria which produce water-insoluble polysaccharides from sucrose

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dextrans and related glucans produced from sucrose by lactic acid bacteria have been studied for many years and are used in numerous commercial applications and products. Most of these glucans are water-soluble, except for a few notable exceptions from cariogenic Streptococcus spp. and a very small ...

  14. Long-Chain Fatty Acids Elicit a Bitterness-Masking Effect on Quinine and Other Nitrogenous Bitter Substances by Formation of Insoluble Binary Complexes.

    PubMed

    Ogi, Kayako; Yamashita, Haruyuki; Terada, Tohru; Homma, Ryousuke; Shimizu-Ibuka, Akiko; Yoshimura, Etsuro; Ishimaru, Yoshiro; Abe, Keiko; Asakura, Tomiko

    2015-09-30

    We have previously found that fatty acids can mask the bitterness of certain nitrogenous substances through direct molecular interactions. Using isothermal titration calorimetry, we investigated the interactions between sodium oleate and 22 bitter substances. The hydrochloride salts of quinine, promethazine, and propranolol interacted strongly with fatty acids containing 12 or more carbon atoms. The (1)H NMR spectra of these substances, obtained in the presence of the sodium salts of the fatty acids in dimethyl sulfoxide, revealed the formation of hydrogen bonds between the nitrogen atoms of the bitter substances and the carboxyl groups of the fatty acids. When sodium laurate and the hydrochloride salt of quinine were mixed in water, an equimolar complex formed as insoluble heterogeneous needlelike crystals. These results suggested that fatty acids interact directly with bitter substances through hydrogen bonds and hydrophobic interactions to form insoluble binary complexes that mask bitterness. PMID:26365517

  15. Insoluble Fe-humic acid complex as a solid-phase electron mediator for microbial reductive dechlorination.

    PubMed

    Zhang, Chunfang; Zhang, Dongdong; Li, Zhiling; Akatsuka, Tetsuji; Yang, Suyin; Suzuki, Daisuke; Katayama, Arata

    2014-06-01

    We report that the insoluble Fe-HA complex, which was synthesized with both commercial Aldrich humic acid (HA) and natural HA, functions as a solid-phase electron mediator (EM) for the anaerobic microbial dechlorination of pentachlorophenol. Spectroscopic characterizations and sequential Fe extraction demonstrated that the Fe-HA complex was predominated with Na4P2O7-labile Fe (represented as the organically bound Fe fraction) and poorly ordered Fe fraction (the fraction left in the residue after the sequential extraction), which were associated with different possible binding processes with carboxylate and phenolic groups. The change in the electron-mediating activity caused by Fe extraction indicated that the electron-mediating function of the Fe-HA complex is attributable to the Na4P2O7-labile Fe fraction. The Fe-HA complex also accelerated the microbial reduction of Fe(III) oxide, which suggested the presence of multiple electron-mediating functions in the complex. The electron shuttle assay showed that the Fe-HA complex had an electron-accepting capacity of 0.82 mequiv g(-1) dry Fe-HA complex. The presence of redox-active moieties in the Fe-HA complex was verified by cyclic voltammetry analysis of the sample after electrical reduction, with a redox potential estimated at 0.02 V (vs a standard hydrogen electrode). PMID:24758743

  16. Potent inhibitory effects of D-tagatose on the acid production and water-insoluble glucan synthesis of Streptococcus mutans GS5 in the presence of sucrose.

    PubMed

    Sawada, Daijo; Ogawa, Takaaki; Miyake, Minoru; Hasui, Yoshinori; Yamaguchi, Fuminori; Izumori, Ken; Tokuda, Masaaki

    2015-01-01

    We examined and compared the inhibitory effects of D-tagatose on the growth, acid production, and water-insoluble glucan synthesis of GS5, a bacterial strain of Streptococcus mutans, with those of xylitol, D-psicose, L-psicose and L-tagatose. GS5 was cultured for 12h in a medium containing 10% (w/v) of xylitol, D-psicose, L-psicose, D-tagatose or L-tagatose, and the inhibitory effect of GS5 growth was assessed. Each sugar showed different inhibitory effects on GS5. Both D-tagatose and xylitol significantly inhibited the acid production and water-insoluble glucan synthesis of GS5 in the presence of 1% (w/v) sucrose. However, the inhibitory effect of acid production by D-tagatose was significantly stronger than that of xylitol in presence of sucrose. PMID:25899632

  17. Incorporation of glycine-2-C-14 in acid-insoluble proteins of rat bones and teeth during hypokinesia and administration of thyrocalcitonine

    NASA Technical Reports Server (NTRS)

    Volozhin, A. I.; Stekolnikov, L. I.; Uglova, N. N.; Potkin, V. Y.

    1979-01-01

    A forced limitation of the motor activity in rats (from 5 to 60 days) results in reduced incorporation of glycine 2-C14 in the total acid insoluble proteins of limb bones and its increase in the teeth and mandibular-maxillary bones. Daily administration of five micrograms of thyrocalcitonine together with polyvinylpyrrolidone normalizes the protein metabolism in the bone tissues during the 40 days of experimentation.

  18. Catalyst of a metal heteropoly acid salt that is insoluble in a polar solvent on a non-metallic porous support and method of making

    DOEpatents

    Wang, Yong [Richland, WA; Peden, Charles H. F. [West Richland, WA; Choi, Saemin [Richland, WA

    2002-10-29

    The present invention includes a catalyst having (a) a non-metallic support having a plurality of pores; (b) a metal heteropoly acid salt that is insoluble in a polar solvent on the non-metallic support; wherein at least a portion of the metal heteropoly acid salt is dispersed within said plurality of pores. The present invention also includes a method of depositing a metal heteropoly acid salt that is insoluble in a polar solvent onto a non-metallic support having a plurality of pores. The method has the steps of: (a) obtaining a first solution containing a first precursor of a metal salt cation; (b) obtaining a second solution containing a second precursor of a heteropoly acid anion in a solvent having a limited dissolution potential for said first precursor; (c) impregnating the non-metallic support with the first precursor forming a first precursor deposit within the plurality of pores, forming a first precursor impregnated support; (d) heating said first precursor impregnated support forming a bonded first precursor impregnated support; (e) impregnating the second precursor that reacts with the precursor deposit and forms the metal heteropoly acid salt.

  19. Catalyst Of A Metal Heteropoly Acid Salt That Is Insoluble In A Polar Solvent On A Non-Metallic Porous Support And Method Of Making

    DOEpatents

    Wang. Yong; Peden. Charles H. F.; Choi. Saemin

    2004-11-09

    The present invention includes a catalyst having (a) a non-metallic support having a plurality of pores; (b) a metal heteropoly acid salt that is insoluble in a polar solvent on the non-metallic support; wherein at least a portion of the metal heteropoly acid salt is dispersed within said plurality of pores. The present invention also includes a method of depositing a metal heteropoly acid salt that is insoluble in a polar solvent onto a non-metallic support having a plurality of pores. The method has the steps of: (a) obtaining a first solution containing a first precursor of a metal salt cation; (b) obtaining a second solution containing a second precursor of a heteropoly acid anion in a solvent having a limited dissolution potential for said first precursor; (c) impregnating the non-metallic support with the first precursor forming a first precursor deposit within the plurality of pores, forming a first precursor impregnated support; (d) heating said first precursor impregnated support forming a bonded first precursor impregnated support; (e) impregnating the second precursor that reacts with the precursor deposit and forms the metal heteropoly acid salt.

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

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  1. Superwetting double-layer polyester materials for effective removal of both insoluble oils and soluble dyes in water.

    PubMed

    Li, Bucheng; Wu, Lei; Li, Lingxiao; Seeger, Stefan; Zhang, Junping; Wang, Aiqin

    2014-07-23

    Inspired by the mussel adhesive protein and the lotus leaf, Ag-based double-layer polyester (DL-PET) textiles were fabricated for effective removal of organic pollutants in water. The DL-PET textiles are composed of a top superamphiphilic layer and a bottom superhydrophobic/superoleophilic layer. First, the PET textiles were modified with a layer of polydopamine (PDA) and deposited with Ag nanoparticles to form the PET@PDA@Ag textiles. The top superamphiphilic layer, formed by immobilizing Ag3PO4 nanoparticles on the PET@PDA@Ag textile, shows excellent visible-light photocatalytic activity. The bottom superhydrophobic/superoleophilic layer, formed by modifying the PET@PDA@Ag textile using dodecyl mercaptan, is mechanically, environmentally, and chemically very stable. The water-insoluble oils with low surface tension can penetrate both layers of the DL-PET textiles, while the water with soluble organic dyes can only selectively wet the top layer owing to their unique wettability. Consequently, the water-soluble organic contaminants in the collected water can be decomposed by the Ag3PO4 nanoparticles of the top layer under visible-light irradiation or even sunlight in room conditions. Thus, the DL-PET textiles can remove various kinds of organic pollutants in water including both insoluble oils and soluble dyes. The DL-PET textiles feature unique wettability, high oil/water separation efficiency, and visible-light photocatalytic activity. PMID:24956183

  2. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false Insoluble wastes. 227.12 Section 227.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR... Insoluble wastes. (a) Solid wastes consisting of inert natural minerals or materials compatible with...

  3. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 26 2013-07-01 2013-07-01 false Insoluble wastes. 227.12 Section 227.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR... Insoluble wastes. (a) Solid wastes consisting of inert natural minerals or materials compatible with...

  4. Soluble vs. insoluble fiber

    MedlinePlus

    ... soluble and insoluble. Both are important for health, digestion, and preventing diseases. Soluble fiber attracts water and turns to gel during digestion. This slows digestion. Soluble fiber is found in ...

  5. Estimating pasture intake and nutrient digestibility of growing pigs fed a concentrate-forage diet by n-alkane and acid-insoluble ash markers.

    PubMed

    Kanga, Jean Serge; Kanengoni, Arnold Tapera; Makgothi, Onkabetswe Gogakgamatsamang; Baloyi, Joseph Jimu

    2012-10-01

    A study was carried out to determine voluntary forage intake and nutrient digestibility in growing pigs fed a mixed forage and concentrate diet. Twenty-five 8-week-old Large White × Landrace crossbred male pigs (27 ± 3.8 kg) were blocked by weight into five groups, and each was randomly allocated to four indoor treatments (A, B, C, and D), which received 100, 90, 80, and 70 % of ad lib concentrated intake and an outdoor treatment (E) that received 80 % of ad lib concentrate. Indoor treatments were either fed the concentrate only (A) or also received freshly cut Kikuyu grass (Pennissetum clandestinum) ad libitum (B, C, and D), while pigs on treatment E were reared outdoors in Kikuyu grass paddocks. There was a significant correlation between the amount of concentrate offered and its intake (P < 0.01). The intake of Kikuyu was similar among treatments (P > 0.05). Mean acid-insoluble ash digestibility estimates of organic and dry matter were superior to C(32) estimates (P < 0.05). Kikuyu intake was higher (P < 0.05) than the estimated intake by 0.076 ± 0.03 kg. It was concluded that Kikuyu intake was not affected by the reduction of the concentrate allowance, and this should be taken into consideration when feeding pigs on pasture. PMID:22467043

  6. Effect of insoluble-low fermentable fiber from corn on energy, fiber, and amino acid digestibility, and on hindgut degradability of fiber and growth performance of pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extensive use of corn co-products in swine diets increases the concentration of dietary fiber, raising concerns about energy and nutrient digestibility, and ultimately on pig performance. A metabolism trial was conducted to determine the effect of increasing levels of insoluble-low fermentable fiber...

  7. Short communication: Evaluation of acid-insoluble ash and indigestible neutral detergent fiber as total-tract digestibility markers in dairy cows fed corn silage-based diets.

    PubMed

    Lee, C; Hristov, A N

    2013-08-01

    The objective of this experiment was to evaluate acid-insoluble ash (AIA) and indigestible NDF (iNDF) as intrinsic digestibility markers in comparison with total fecal collection (TC) in dairy cows fed corn silage- and alfalfa haylage-based diets. The experiment was part of a larger experiment, which involved 8 Holstein cows [102±28.4 d in milk, 26.4±0.27 kg/d of dry matter (DM) intake, and 43±5.3 kg/d milk yield]. The experimental design was a replicated 4×4 Latin square with the following treatments: metabolizable protein (MP)-adequate diet [15.6% crude protein (CP); high-CP], MP-deficient diet (14.0% CP; low-CP), and 2 other low-CP diets supplemented (top-dressed) with ruminally protected Lys or Lys and Met. Data for the 3 low-CP diets were combined for this analysis. Total feces were collected for 5 consecutive days during each period to estimate total-tract apparent digestibility. Digestibility was also estimated using AIA (digestion with 2 N HCl) and iNDF (12-d ruminal incubation in 25-μm-pore-size bags). Significant diet × digestibility method interactions were observed for fecal output of nutrients and digestibility. Fecal output of nutrients estimated using AIA or iNDF was lower compared with TC and fecal output of DM, organic matter, and CP tended to be higher for iNDF compared with AIA for the high-CP diet. For the low-CP diet, however, fecal output of all nutrients was lower for AIA compared with TC and was higher for iNDF compared with TC. Data from this experiment showed that, compared with TC, AIA underestimated fecal output and overestimated digestibility, particularly evident with the fiber fractions and the protein-deficient diet. Compared with TC, fecal output was overestimated and digestibility of the low-CP diet was underestimated when iNDF was used as a marker, although the magnitude of the difference was smaller compared with that for AIA. In the conditions of the current study, iNDF appeared to be a more reliable digestibility marker

  8. In-depth proteomic analysis of a mollusc shell: acid-soluble and acid-insoluble matrix of the limpet Lottia gigantea

    PubMed Central

    2012-01-01

    Background Invertebrate biominerals are characterized by their extraordinary functionality and physical properties, such as strength, stiffness and toughness that by far exceed those of the pure mineral component of such composites. This is attributed to the organic matrix, secreted by specialized cells, which pervades and envelops the mineral crystals. Despite the obvious importance of the protein fraction of the organic matrix, only few in-depth proteomic studies have been performed due to the lack of comprehensive protein sequence databases. The recent public release of the gastropod Lottia gigantea genome sequence and the associated protein sequence database provides for the first time the opportunity to do a state-of-the-art proteomic in-depth analysis of the organic matrix of a mollusc shell. Results Using three different sodium hypochlorite washing protocols before shell demineralization, a total of 569 proteins were identified in Lottia gigantea shell matrix. Of these, 311 were assembled in a consensus proteome comprising identifications contained in all proteomes irrespective of shell cleaning procedure. Some of these proteins were similar in amino acid sequence, amino acid composition, or domain structure to proteins identified previously in different bivalve or gastropod shells, such as BMSP, dermatopontin, nacrein, perlustrin, perlucin, or Pif. In addition there were dozens of previously uncharacterized proteins, many containing repeated short linear motifs or homorepeats. Such proteins may play a role in shell matrix construction or control of mineralization processes. Conclusions The organic matrix of Lottia gigantea shells is a complex mixture of proteins comprising possible homologs of some previously characterized mollusc shell proteins, but also many novel proteins with a possible function in biomineralization as framework building blocks or as regulatory components. We hope that this data set, the most comprehensive available at present, will

  9. Comparison of acid-detergent lignin, alkaline-peroxide lignin, and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibility by cattle offered bermudagrass hays of varying nutrient composition

    PubMed Central

    2014-01-01

    Background The potential for acid-detergent insoluble ash (ADIA), alkaline-peroxide lignin (APL), and acid-detergent lignin (ADL) to predict fecal output (FO) and dry matter digestibility (DMD) by cattle offered bermudagrass [Cynodon dactylon (L.) Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 hay diets: low (L), medium low (ML), medium high (MH), and high (H) crude protein (CP) concentration (79, 111, 131, and 164 g CP/kg on a DM basis, respectively). Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08:00 and 16:00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake (DMI), DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. Results Forage DMI was affected by diet (P = 0.02), and DMI from MH and H was greater (P < 0.05) than from L. Apparent DMD tended (P = 0.08) to differ among diets while FO (P = 0.20) was not affected by diet treatments. Average ADL recovery (1.16) was greater (P < 0.05) than that of ADIA (1.03) and APL (1.06), but ADIA and APL did not differ (P = 0.42). Estimates of FO and DMD derived using APL and ADIA were not different (P ≥ 0.05) from total fecal collection while those using ADL differed (P < 0.05). There was no diet by marker interaction (P ≥ 0.22) for either FO or DMD. Conclusion Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. Results from such studies may be used to develop improved equations to predict energy values of

  10. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ....12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE EVALUATION OF PERMIT APPLICATIONS FOR OCEAN DUMPING OF MATERIALS Environmental Impact § 227.12... ocean environment may be generally approved for ocean dumping provided they are insoluble above...

  11. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true Insoluble wastes. 227.12 Section 227.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN DUMPING CRITERIA FOR THE... wastes. (a) Solid wastes consisting of inert natural minerals or materials compatible with the...

  12. Acid soluble, pepsin resistant platelet aggregating material

    SciTech Connect

    Schneider, M.D.

    1982-08-31

    Disclosed is an acid soluble, pepsin resistant, platelet aggregating material isolated from equine arterial tissue by extraction with dilute aqueous acid. The method of isolation and use to control bleeding are described. 4 figs.

  13. Soluble and insoluble fiber (image)

    MedlinePlus

    Dietary fiber is the part of food that is not affected by the digestive process in the body. ... of the stool. There are two types of dietary fiber, soluble and insoluble. Soluble fiber retains water and ...

  14. Acid Rain: Resource Materials for Schools.

    ERIC Educational Resources Information Center

    American Biology Teacher, 1983

    1983-01-01

    Provides listings of acid rain resource material groups under: (1) printed materials (pamphlets, books, articles); (2) audiovisuals (slide/tape presentations, tape, video-cassette); (3) miscellaneous (buttons, pocket lab, umbrella); (4) transparencies; (5) bibliographies; and (6) curriculum materials. Sources and prices (when applicable) are…

  15. Measurement of xylanase activity with insoluble xylan substrate.

    PubMed Central

    Nummi, M; Perrin, J M; Niku-Paavola, M L; Enari, T M

    1985-01-01

    Insoluble xylan was prepared from ground birch (Betula pubescens) pulp by alkali extraction and precipitation with ethanol. The only sugar detected after acid hydrolysis of the preparation was xylose. The insoluble xylan was used as substrate in a nephelometric assay to determine the xylanase (EC 3.2.1.8, 1,4-beta-D-xylan xylanohydrolase and EC 3.2.1.37, 1,4-beta-D-xylan xylohydrolase) activities of Aspergillus and Trichoderma enzymes. The nephelometric method is reliable in evaluating xylanase hydrolysis of insoluble xylan. PMID:3922355

  16. Isotopic composition of hydrogen in insoluble organic matter from cherts

    NASA Technical Reports Server (NTRS)

    Krishnamurthy, R. V.; Epstein, S.

    1991-01-01

    Robert (1989) reported the presence of unusually enriched hydrogen in the insoluble HF-HCl residue extracted from two chert samples of Eocene and Pliocene ages. Since the presence of heavy hydrogen might be due to the incorporation of extraterrestrial materials, we desired to reexamine the same samples to isolate the D-rich components. Our experiments did not reveal any D-rich components, but the hydrogen isotope composition of the insoluble residue of the two chert samples was well within the range expected for terrestrial organic matter. We also describe a protocol that needs to be followed in the hydrogen isotope analysis of any insoluble organic matter.

  17. Humic and fluvic acids and organic colloidal materials in the environment

    SciTech Connect

    Gaffney, J.S.; Marley, N.A.; Clark, S.B.

    1996-04-01

    Humic substances are ubiquitous in the environment, occurring in all soils, waters, and sediments of the ecosphere. Humic substances arise from the decomposition of plant and animal tissues yet are more stable than their precursors. Their size, molecular weight, elemental composition, structure, and the number and position of functional groups vary, depending on the origin and age of the material. Humic and fulvic substances have been studied extensively for more than 200 years; however, much remains unknown regarding their structure and properties. Humic substances are those organic compounds found in the environment that cannot be classified as any other chemical class of compounds. They are traditionally defined according to their solubilities. Fulvic acids are those organic materials that are soluble in water at all pH values. Humic acids are those materials that are insoluble at acidic pH values (pH < 2) but are soluble at higher pH values. Humin is the fraction of natural organic materials that is insoluble in water at all pH values. These definitions reflect the traditional methods for separating the different fractions from the original mixture. The humic content of soils varies from 0 to almost 10%. In surface waters, the humic content, expressed as dissolved organic carbon (DOC), varies from 0.1 to 50 ppm in dark-water swamps. In ocean waters, the DOC varies from 0.5 to 1.2 ppm at the surface, and the DOC in samples from deep groundwaters varies from 0.1 to 10 ppm. In addition, about 10% of the DOC in surface waters is found in suspended matter, either as organic or organically coated inorganic particulates. Humic materials function as surfactants, with the ability to bind both hydrophobic and hydrophyllic materials, making numic and fluvic materials effective agents in transporting both organic and inorganic contaminants in the environment.

  18. Chromium(III), insoluble salts

    Integrated Risk Information System (IRIS)

    Chromium ( III ) , insoluble salts ; CASRN 16065 - 83 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments

  19. Resistance of geopolymer materials to acid attack

    SciTech Connect

    Bakharev, T

    2005-04-01

    This article presents an investigation into durability of geopolymer materials manufactured using a class F fly ash (FA) and alkaline activators when exposed to 5% solutions of acetic and sulfuric acids. The main parameters studied were the evolution of weight, compressive strength, products of degradation and microstructural changes. The degradation was studied using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The performance of geopolymer materials when exposed to acid solutions was superior to ordinary Portland cement (OPC) paste. However, significant degradation of strength was observed in some geopolymer materials prepared with sodium silicate and with a mixture of sodium hydroxide and potassium hydroxide as activators. The deterioration observed was connected to depolymerisation of the aluminosilicate polymers in acidic media and formation of zeolites, which in some cases lead to a significant loss of strength. The best performance was observed in the geopolymer material prepared with sodium hydroxide and cured at elevated temperature, which was attributed to a more stable cross-linked aluminosilicate polymer structure formed in this material.

  20. Biochemical Composition and Assembly of Biosilica-associated Insoluble Organic Matrices from the Diatom Thalassiosira pseudonana.

    PubMed

    Kotzsch, Alexander; Pawolski, Damian; Milentyev, Alexander; Shevchenko, Anna; Scheffel, André; Poulsen, Nicole; Shevchenko, Andrej; Kröger, Nils

    2016-03-01

    The nano- and micropatterned biosilica cell walls of diatoms are remarkable examples of biological morphogenesis and possess highly interesting material properties. Only recently has it been demonstrated that biosilica-associated organic structures with specific nanopatterns (termed insoluble organic matrices) are general components of diatom biosilica. The model diatom Thalassiosira pseudonana contains three types of insoluble organic matrices: chitin meshworks, organic microrings, and organic microplates, the latter being described in the present study for the first time. To date, little is known about the molecular composition, intracellular assembly, and biological functions of organic matrices. Here we have performed structural and functional analyses of the organic microrings and organic microplates from T. pseudonana. Proteomics analysis yielded seven proteins of unknown function (termed SiMat proteins) together with five known silica biomineralization proteins (four cingulins and one silaffin). The location of SiMat1-GFP in the insoluble organic microrings and the similarity of tyrosine- and lysine-rich functional domains identifies this protein as a new member of the cingulin protein family. Mass spectrometric analysis indicates that most of the lysine residues of cingulins and the other insoluble organic matrix proteins are post-translationally modified by short polyamine groups, which are known to enhance the silica formation activity of proteins. Studies with recombinant cingulins (rCinY2 and rCinW2) demonstrate that acidic conditions (pH 5.5) trigger the assembly of mixed cingulin aggregates that have silica formation activity. Our results suggest an important role for cingulins in the biogenesis of organic microrings and support the hypothesis that this type of insoluble organic matrix functions in biosilica morphogenesis. PMID:26710847

  1. 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.

  2. Plant and soil intake by organic broilers reared in tree- or grass-covered plots as determined by means of n-alkanes and of acid-insoluble ash.

    PubMed

    Jurjanz, S; Germain, K; Juin, H; Jondreville, C

    2015-05-01

    Free-range birds such as organic broilers may ingest soil and plants during exploration. The estimation of such intakes is of great interest to quantify possible nutritional supplies and also to evaluate the risk of exposure to parasites or to environmental contaminants. Marker-based techniques are now available and would allow to quantify plant and, especially, soil intake in free-range birds, and this quantification was the aim of this study. Methodologically, the proportion of plants in diet intake was determined first using a method based on n-alkanes. Subsequently, the fraction of soil in the total intake was estimated with a second marker, acid-insoluble ash. This approach was carried out to estimate ingested amounts of plants and soil for five successive flocks of organic broilers, exploring grass-covered yards or those under trees, at two time points for each yard: 51 and 64 days of age. Each factor combination (yard type×period=flock number×age) was repeated on two different yards of 750 broilers each. The birds' plant intake varied widely, especially on grass-covered yards. The proportion of plant intake was significantly higher on grass-covered plots than under trees and was also affected, but to a lesser extent, by age or flock number. The ingestion of plants would generally not exceed 11 g of DM daily, except two extreme outliers of nearly 30 g. The daily plant intake under trees tended to be lower and never exceeded 7 g of DM. The amount of ingested plants increased significantly for spring flocks. It increased slightly but significantly with age. The proportion of ingested soil was significantly higher under trees than on grass-covered yards. Dry soil intake was generally low with not more than 3 g per day. Only in adverse conditions - that is, older birds exploring yards under trees in winter - soil intake reached the extreme value of nearly 5 g. Broilers on yards under trees ingested significantly more soil than on grass-covered yards with least

  3. Characterization of insoluble fractions of TNT transformed by composting

    SciTech Connect

    Caton, J.E.; Ho, C.H.; Williams, R.T.; Griest, W.H. )

    1994-05-01

    Soil contaminated with explosives was supplemented with carbon-14 labelled 2,4,6-trinitrotoluene ([sup 14]C-TNT) and was composted in a field static pile composting experiment. After 90 d of composting, the distribution of carbon-14 ([sup 14]C) activity in fractions from acetonitrile extraction ([open quotes]free[close quotes] fraction, 1.2% of the initial [sup 14]C-activity) and filtration ([open quotes]insoluble-particle[close quotes] fraction, 17.9%), alkaline hydrolysis ([open quotes]insoluble-hydrolyzable[close quotes] fraction, 56.8%), and combustion of the residue ([open quotes]insoluble-nonhydrolyzable[close quotes] fraction, 4.7%) showed that the bulk of the [sup 14]C-activity, and presumably transformed product(s) of the [sup 14]C-TNT, accumulated in a nonextractable, but hydrolyzable fraction. Repetitive aqueous leaching of the compost and also ultraviolet light irradiation followed by leaching suggest that the insoluble fraction of transformed TNT should not be released appreciably by the action of acid rain or sunlight. 16 refs., 11 figs., 2 tabs.

  4. Acid soluble platelet aggregating material isolated from human umbilical cord

    SciTech Connect

    Schneider, M.D.

    1983-12-27

    An acid soluble, pepsin sensitive platelet aggregating material is isolated from human umbilical cord tissue by extraction with dilute aqueous acid. The method of isolation is disclosed and its use to control bleeding is described. 2 figs.

  5. Acid-functionalized polyolefin materials and their use in acid-promoted chemical reactions

    DOEpatents

    Oyola, Yatsandra; Tian, Chengcheng; Bauer, John Christopher; Dai, Sheng

    2016-06-07

    An acid-functionalized polyolefin material that can be used as an acid catalyst in a wide range of acid-promoted chemical reactions, wherein the acid-functionalized polyolefin material includes a polyolefin backbone on which acid groups are appended. Also described is a method for the preparation of the acid catalyst in which a precursor polyolefin is subjected to ionizing radiation (e.g., electron beam irradiation) of sufficient power and the irradiated precursor polyolefin reacted with at least one vinyl monomer having an acid group thereon. Further described is a method for conducting an acid-promoted chemical reaction, wherein an acid-reactive organic precursor is contacted in liquid form with a solid heterogeneous acid catalyst comprising a polyolefin backbone of at least 1 micron in one dimension and having carboxylic acid groups and either sulfonic acid or phosphoric acid groups appended thereto.

  6. Acid Rain Materials for Classroom Use.

    ERIC Educational Resources Information Center

    Factor, Lance; Kooser, Robert G.

    This booklet contains three separate papers suitable for use in an advanced high school or college chemistry course. The first paper provides background information on acids and bases. The second paper provides additional background information, focusing on certain aspects of atmospheric chemistry as it relates to the acid rain problem. An attempt…

  7. Materials characterization of phosphoric acid fuel cell system

    NASA Technical Reports Server (NTRS)

    Venkatesh, Srinivasan

    1986-01-01

    The component materials used in the fabrication of phosphoric acid fuel cells (PAFC) must have mechanical, chemical, and electrochemical stability to withstand the moderately high temperature (200 C) and pressure (500 kPa) and highly oxidizing nature of phosphoric acid. This study discusses the chemical and structural stability, performance and corrosion data on certain catalysts, catalyst supports, and electrode support materials used in PAFC applications.

  8. Water-insoluble Silk Films with Silk I Structure

    SciTech Connect

    Lu, Q.; Hu, X; Wang, X; Kluge, J; Lu, S; Cebe, P; Kaplan, D

    2010-01-01

    Water-insoluble regenerated silk materials are normally produced by increasing the {beta}-sheet content (silk II). In the present study water-insoluble silk films were prepared by controlling the very slow drying of Bombyx mori silk solutions, resulting in the formation of stable films with a predominant silk I instead of silk II structure. Wide angle X-ray scattering indicated that the silk films stabilized by slow drying were mainly composed of silk I rather than silk II, while water- and methanol-annealed silk films had a higher silk II content. The silk films prepared by slow drying had a globule-like structure at the core surrounded by nano-filaments. The core region was composed of silk I and silk II, surrounded by hydrophilic nano-filaments containing random turns and {alpha}-helix secondary structures. The insoluble silk films prepared by slow drying had unique thermal, mechanical and degradative properties. Differential scanning calorimetry results revealed that silk I crystals had stable thermal properties up to 250 C, without crystallization above the T{sub g}, but degraded at lower temperatures than silk II structure. Compared with water- and methanol-annealed films the films prepared by slow drying had better mechanical ductility and were more rapidly enzymatically degraded, reflecting the differences in secondary structure achieved via differences in post processing of the cast silk films. Importantly, the silk I structure, a key intermediate secondary structure for the formation of mechanically robust natural silk fibers, was successfully generated by the present approach of very slow drying, mimicking the natural process. The results also point to a new mode of generating new types of silk biomaterials with enhanced mechanical properties and increased degradation rates, while maintaining water insolubility, along with a low {beta}-sheet content.

  9. Water-Insoluble Silk Films with Silk I Structure

    PubMed Central

    Lu, Qiang; Hu, Xiao; Wang, Xiaoqin; Kluge, Jonathan A.; Lu, Shenzhou; Cebe, Peggy; Kaplan, David L.

    2009-01-01

    Water-insoluble regenerated silk materials are normally achieved by increasing β-sheet content (silk II). In the present study, water-insoluble silk films were prepared by controlling very slow drying of B. mori silk solutions, resulting in the formation of stable films with dominating silk I instead of silk II structure. Wide angle x-ray scattering (WAXS) indicated that the silk films stabilized by slow drying were mainly composed of silk I rather than silk II, while water- and methanol-annealed silk films had a higher silk II content. The silk films prepared through slow drying had a globule-like structure in the core with nano-filaments. The core region was composed of silk I and silk II, and these regions are surrounded by hydrophilic nano-filaments containing random, turns, and α-helix secondary structures. The insoluble silk films prepared by slow drying had unique thermal, mechanical and degradative properties. DSC results revealed that silk I crystals had stable thermal properties up to 250°C, without crystallization above the Tg, but degraded in lower temperature than silk II structure. Compared with water- and methanol-annealed films, the films prepared through slow drying achieved better mechanical ductility and more rapid enzymatic degradation, reflective of the differences in secondary structure achieved via differences in post processing of the cast silk films. Importantly, the silk I structure, a key intermediate secondary structure for the formation of mechanically robust natural silk fibers, was successfully generated in the present approach of very slow drying, mimicking the natural process. The results also point to a new mode to generate new types of silk biomaterials, where mechanical properties can be enhanced, and degradation rates increased, yet water insolubility is maintained along with low beta sheet content. PMID:19874919

  10. Proteomics analysis of the nacre soluble and insoluble proteins from the oyster Pinctada margaritifera.

    PubMed

    Bédouet, Laurent; Marie, Arul; Dubost, Lionel; Péduzzi, Jean; Duplat, Denis; Berland, Sophie; Puisségur, Marion; Boulzaguet, Hélène; Rousseau, Marthe; Milet, Christian; Lopez, Evelyne

    2007-01-01

    Shell nacre is laid upon an organic cell-free matrix, part of which, paradoxically, is water soluble and displays biological activities. Proteins in the native shell also constitute an insoluble network and offer a model for studying supramolecular organization as a means of self-ordering. Consequently, difficulties are encountered in extraction and purification strategies for protein characterization. In this work, water-soluble proteins and the insoluble conhiolin residue of the nacre of Pinctada margaritifera matrix were analyzed via a proteomics approach. Two sequences homologous to nacre matrix proteins of other Pinctada species were identified in the water-soluble extract. One of them is known as a fundamental component of the insoluble organic matrix of nacre. In the conchiolin, the insoluble residue, four homologs of Pinctada nacre matrix proteins were found. Two of them were the same as the molecules characterized in the water-soluble extract. Results established that soluble and insoluble proteins of the nacre organic matrix share constitutive material. Surprisingly, a peptide in the conchiolin residue was found homologous to a prismatic matrix protein of Pinctada fucata, suggesting that prismatic and nacre matrices may share common proteins. The insoluble properties of shell matrix proteins appear to arise from structural organization via multimerization. The oxidative activity, found in the water-soluble fraction of the nacre matrix, is proposed as a leading process in the transformation of transient soluble proteins into the insoluble network of conchiolin during nacre growth. PMID:17641930

  11. CHALLENGES IN MEASURING INSOLUBLE DIETARY FIBER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objectives of this review are to define the criteria needed to evaluate insoluble dietary fiber (IDF) methods, discuss their relevance in meeting nutritional needs, describe problems with empirical IDF methods, and assess their relative merits. The challenge for the researcher, nutritionist, and...

  12. Endoplasmic Reticulum Bodies: Solving the Insoluble

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant cells produce and accumulate insoluble triglycerides, proteins and rubber that are assembled into inert ER-derived organelles broadly termed ER-bodies. ER-bodies appear to originate from tubular ER domains that are maintained by cytoskeletal interactions and integral ER proteins. ER-bodies seq...

  13. CELL WALL HYDROXYCINNAMATES IN WILD RICE (ZIZANIA AQUATICA L.) INSOLUBLE DIETARY FIBER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The contents of ester-linked phenolic acids in wild rice (Zizania aquatica L.) dietary fibre were quantified by HPLC analysis, and oligosaccharide hydroxycinnamates were isolated and identified to investigate the linkages of hydroxycinnamic acids to cell wall polymers. In wild rice insoluble dietary...

  14. Surface-functionalized diatom microcapsules for drug delivery of water-insoluble drugs.

    PubMed

    Aw, Moom Sinn; Bariana, Manpreet; Yu, Yang; Addai-Mensah, Jonas; Losic, Dusan

    2013-08-01

    Naturally available and biocompatible materials are potential substitutes for synthetic mesoporous materials as suitable drug carriers for the development of cost-effective drug delivery systems. This work investigates the application of a porous silica material derived from diatoms, also known as diatomaceous earth. The aim is to explore the surface functionalization of diatom microcapsules and their impact on the drug loading and release characteristics of water-insoluble drugs. Indomethacin was used as the model for poorly soluble drug. The surface modification on diatoms was performed with two organosilanes; 3-aminopropyltriethoxy silane and N-(3-(trimethoxysilyl) propyl) ethylene diamine and phosphonic acids (2-carboxyethyl-phosphonic acid and 16-phosphono-hexadecanoic acid) providing organic surface hydrophilic and hydrophobic properties. Extensive characterizations using scanning electron microscopy, X-ray photoelectron spectroscopy and differential scanning calorimetry was performed to confirm covalent grafting of monolayer aminosilane and phosphonic acid on the diatom surfaces. Differences in loading capacity of diatoms (15-24%) and release time (6-15 days) were observed which is due to the presence of different functional groups on the surface. It was found that 2-carboxyethyl-phosphonic acid, 3-aminopropyltriethoxy silane and N-(3-(trimethoxysilyl) propyl) ethylene diamine render diatom surfaces hydrophilic, due to polar carboxyl functional group (COOH) and active amine species (NH and NH2) that favor drug adsorption; better encapsulation efficiency and prolonged release of drugs, over the hydrophobic surface created by 16-phosphono-hexadecanoic acid. This work demonstrates diatom porous silica as a promising drug carrier, with possibility to further improve their performances by tailoring their surface functionalities to achieve the required drug loading and release characteristics for different therapeutic conditions. PMID:22457043

  15. Extraterrestrial material analysis: loss of amino acids during liquid-phase acid hydrolysis

    NASA Astrophysics Data System (ADS)

    Buch, Arnaud; Brault, Amaury; Szopa, Cyril; Freissinet, Caroline

    2015-04-01

    Searching for building blocks of life in extraterrestrial material is a way to learn more about how life could have appeared on Earth. With this aim, liquid-phase acid hydrolysis has been used, since at least 1970 , in order to extract amino acids and other organic molecules from extraterrestrial materials (e.g. meteorites, lunar fines) or Earth analogues (e.g. Atacama desert soil). This procedure involves drastic conditions such as heating samples in 6N HCl for 24 h, either under inert atmosphere/vacuum, or air. Analysis of the hydrolyzed part of the sample should give its total (free plus bound) amino acid content. The present work deals with the influence of the 6N HCl hydrolysis on amino acid degradation. Our experiments have been performed on a standard solution of 17 amino acids. After liquid-phase acid hydrolysis (6N HCl) under argon atmosphere (24 h at 100°C), the liquid phase was evaporated and the dry residue was derivatized with N-Methyl-N-(t-butyldimethylsilyl)trifluoroacetamide (MTBSTFA) and dimethylformamide (DMF), followed by gas chromatography-mass spectrometry analysis. After comparison with derivatized amino acids from the standard solution, a significant reduction of the chromatographic peak areas was observed for most of the amino acids after liquid-phase acid hydrolysis. Furthermore, the same loss pattern was observed when the amino acids were exposed to cold 6N HCl for a short amount of time. The least affected amino acid, i.e. glycine, was found to be 73,93% percent less abundant compared to the non-hydrolyzed standard, while the most affected, i.e. histidine, was not found in the chromatograms after hydrolysis. Our experiments thereby indicate that liquid-phase acid hydrolysis, even under inert atmosphere, leads to a partial or total loss of all of the 17 amino acids present in the standard solution, and that a quick cold contact with 6N HCl is sufficient to lead to a loss of amino acids. Therefore, in the literature, the reported increase

  16. Antimicrobial characteristic of insoluble alkylpyridinium iodide.

    PubMed Central

    Nakagawa, Y; Yamano, Y; Tawaratani, T; Kourai, H; Horie, T; Shibasaki, I

    1982-01-01

    Insoluble and soluble alkylpyridinium iodides (C8 to C18) were synthesized. The insoluble agents were quaternized 4-vinylpyridine-divinylbenzene copolymers. The insoluble agent [C12(50)] that contained 50% divinylbenzene and had a C12 alkyl chain was selected as the most suitable insoluble agent. C12(50) showed poor durability of the antibacterial activity, but C12(50), which had lost the activity, was refreshed by washing with ethanol. This washing became ineffective after a few cycles of antibacterial treatment and refreshment. Such C12(50) recovered the activity upon 1.0 N NaOH treatment. The antibacterial activity of C12(50) depended on its surface area. It showed high antimicrobial activity against gram-positive bacteria and also showed activity against gram-negative bacteria and yeasts. But the activities of C12(50) and laurylpyridinium iodide solution were different against some microbes. The antibacterial activities of the agents were investigated against Escherichia coli and Micrococcus luteus under various conditions. The activity of C12(50) was higher at a higher temperature or at a lower cell concentration. The activity of C12(50) decreased on addition of NaCl, glucose, or bovine albumin to the cell suspension or in 0.01 M sodium-potassium phosphate buffer. C12(50) showed less activity when cells were mixed with dead cells or the supernatant of dead cells killed in an autoclave. The mode of action of the laurylpyridinium iodide solution against E. coli and M. luteus was similar to that of C12(50) except for the influence of E. coli cell concentration. PMID:6808918

  17. Extraction of Nucleic Acids from Lyophilized Plant Material

    PubMed Central

    Guinn, Gene

    1966-01-01

    Four methods for extracting nucleic acids from lyophilized cotton (Gossypium hirsutum L. cv. Stoneville 62) leaves and roots were compared. They were based on the use of: (I) HC104; (II) KOH; (III) a mixture of 90% phenol, Tris (hydroxymethyl) aminomethane buffer, and sodium lauryl sulfate; and (IV) NaCl. (I) extracted large amounts of RNA but little DNA and extracted much carbohydrate and protein contaminants. (II) gave a good yield of both RNA and DNA but extracted such large amounts of contaminating material that purification of RNA on an anion exchange column was necessary. (III) extracted only part of the RNA and practically no DNA, but extracted contaminating materials. (IV) resulted in high yields of both RNA and DNA when modified to omit preliminary acid extraction of impurities. The use of cold trichloroacetic acid instead of ethanol, to precipitate NaCl-extracted nucleic acids, separated the nucleic acids from most of the carbohydrate and acid-soluble phosphate contaminants and resulted in good agreement among results by ultraviolet absorbance, pentose tests, and phosphate analysis. This method also resulted in lower protein contents and better ultraviolet absorption spectra than the other methods tested. Nucleic acids were extracted from leaves of 14 other species of plants, in addition to cotton, by this modified NaCl procedure. PMID:16656306

  18. Graphdiyne as a promising material for detecting amino acids

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Gao, Pengfei; Guo, Lei; Zhang, Shengli

    2015-11-01

    The adsorption of glycine, glutamic acid, histidine and phenylalanine on single-layer graphdiyne/ graphene is investigated by ab initio calculations. The results show that for each amino acid molecule, the adsorption energy on graphdiyne is larger than the adsorption energy on graphene and dispersion interactions predominate in the adsorption. Molecular dynamics simulations reveal that at room temperature the amino acid molecules keep migrating and rotating on graphdiyne surface and induce fluctuation in graphdiyne bandgap. Additionally, the photon absorption spectra of graphdiyne-amino-acid systems are investigated. We uncover that the presence of amino acid molecules makes the photon absorption peaks of graphdiyne significantly depressed and shifted. Finally, quantum electronic transport properties of graphdiyne-amino-acid systems are compared with the transport properties of pure graphdiyne. We reveal that the amino acid molecules induce distinct changes in the electronic conductivity of graphdiyne. The results in this paper reveal that graphdiyne is a promising two-dimensional material for sensitively detecting amino acids and may potentially be used in biosensors.

  19. Graphdiyne as a promising material for detecting amino acids

    PubMed Central

    Chen, Xi; Gao, Pengfei; Guo, Lei; Zhang, Shengli

    2015-01-01

    The adsorption of glycine, glutamic acid, histidine and phenylalanine on single-layer graphdiyne/ graphene is investigated by ab initio calculations. The results show that for each amino acid molecule, the adsorption energy on graphdiyne is larger than the adsorption energy on graphene and dispersion interactions predominate in the adsorption. Molecular dynamics simulations reveal that at room temperature the amino acid molecules keep migrating and rotating on graphdiyne surface and induce fluctuation in graphdiyne bandgap. Additionally, the photon absorption spectra of graphdiyne-amino-acid systems are investigated. We uncover that the presence of amino acid molecules makes the photon absorption peaks of graphdiyne significantly depressed and shifted. Finally, quantum electronic transport properties of graphdiyne-amino-acid systems are compared with the transport properties of pure graphdiyne. We reveal that the amino acid molecules induce distinct changes in the electronic conductivity of graphdiyne. The results in this paper reveal that graphdiyne is a promising two-dimensional material for sensitively detecting amino acids and may potentially be used in biosensors. PMID:26568200

  20. Graphdiyne as a promising material for detecting amino acids.

    PubMed

    Chen, Xi; Gao, Pengfei; Guo, Lei; Zhang, Shengli

    2015-01-01

    The adsorption of glycine, glutamic acid, histidine and phenylalanine on single-layer graphdiyne/graphene is investigated by ab initio calculations. The results show that for each amino acid molecule, the adsorption energy on graphdiyne is larger than the adsorption energy on graphene and dispersion interactions predominate in the adsorption. Molecular dynamics simulations reveal that at room temperature the amino acid molecules keep migrating and rotating on graphdiyne surface and induce fluctuation in graphdiyne bandgap. Additionally, the photon absorption spectra of graphdiyne-amino-acid systems are investigated. We uncover that the presence of amino acid molecules makes the photon absorption peaks of graphdiyne significantly depressed and shifted. Finally, quantum electronic transport properties of graphdiyne-amino-acid systems are compared with the transport properties of pure graphdiyne. We reveal that the amino acid molecules induce distinct changes in the electronic conductivity of graphdiyne. The results in this paper reveal that graphdiyne is a promising two-dimensional material for sensitively detecting amino acids and may potentially be used in biosensors. PMID:26568200

  1. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Insoluble glucose isomerase enzyme preparations... Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production of high fructose corn syrup described in §...

  2. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Insoluble glucose isomerase enzyme preparations... RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production...

  3. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Insoluble glucose isomerase enzyme preparations... RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production...

  4. Characterization of water insoluble solids isolated from various biomass fast pyrolysis oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A solid water insoluble material, commonly called pyrolytic lignin, can be isolated from biomass fast pyrolysis oils. Such material was isolated from the bio-oils produced from barley straw, barley hulls, switchgrass, soystraw and oak and then fully characterized. Analytical techniques employed in...

  5. [Determination of Sb and Bi in 24 international geological reference materials by using pressurized acid digestion-ICP-MS].

    PubMed

    Hu, Zhao-chu; Gao, Shan; Liu, Xiao-ming; Yuan, Hong-lin; Liu, Ye; Diwu, Chun-rong

    2007-12-01

    The authors studied in detail the memory effect of Bi, Sb, As and Te in ICP-MS. The produced memory effects of these element were in the order of Bi>Sb>Te>As. Bi was seriously adsorbed by the polypropylene sample storing bottle and the sample introduction system in the low nitric acid medium (0.01%-1% HNO3). The washout effect of 0.1% HF was found to be better than those of 6% HNO3 and 0.1% HClO4. Under the given experiment conditions, the instrumental limit of detection was 0.001 and 0.0001 ng x mL(-1) for Sb and Bi, respectively. The authors report the determination of Sb and Bi in 24 international geological reference materials by using pressurized acid digestion-ICP-MS (including AGV-2, BHVO-2, BCR-2, etc.). Most of the results were found to be in reasonable agreement with the reported values in the literature. The authors' determined values of Sb for GSR-1 (granite; 0.30 microg x g(-1)) and JP-1 (peridotite; 0.045 microg x g(-1)) are obviously higher than those reported values. This is attributed to the efficient pressurized acid digestion, which is generally much more efficient than conventional wet digestions for insoluble minerals. PMID:18330312

  6. Nanoparticles Containing Insoluble Drug for Cancer Therapy

    PubMed Central

    Guo, Shutao; Huang, Leaf

    2014-01-01

    Nanoparticle drug formulations have been extensively researched and developed in the field of drug delivery as a means to efficiently deliver insoluble drugs to tumor cells. By mechanisms of the enhanced permeability and retention effect, nanoparticle drug formulations are capable of greatly enhancing the safety, pharmacokinetic profiles and bioavailability of the administered treatment. Here, the progress of various nanoparticle formulations in both research and clinical applications is detailed with a focus on the development of drug/gene delivery systems. Specifically, the unique advantages and disadvanges of polymeric nanoparticles, liposomes, solid lipid nanoparticles, nanocrystals and lipid-coated nanoparticles for targeted drug delivery will be investigated in detail. PMID:24113214

  7. Effects of mutations on the insoluble glucan synthesized by Leuconostoc mesenteroides NRRL B-1118 glucansucrase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Twelve different amino acids were each substituted for Threonine-654 in a cloned glucansucrase from Leuconostoc mesenteroides NRRL B-1118 (DSR-I). The native enzyme produces a water-insoluble glucan containing approximately 44 mol% 1,3-disubstituted a-D-glucopyranosyl units and 29 mol% 1,6-disubstit...

  8. Adsorption of chromate/organic-acid mixtures in aquifer materials

    SciTech Connect

    Fish, W.; Palmer, C.D.

    1991-07-15

    The overall objective of this project is to develop a fuller understanding of the interactions of mixtures of anionic co-contaminants with oxide-mineral surfaces. Our specific focus is on the competitive interactions of chromate and oxalic acid on ferric oxyhydroxide and on natural aquifer materials. Chromate and oxalate are of practical interest as widespread contaminants at many DOE facilities. However, these anions also are excellent model adsorbates for elucidating fundamental aspects of ionic adsorption processes, particularly with respect to organic acids.

  9. Gradual surface degradation of restorative materials by acidic agents.

    PubMed

    Hengtrakool, Chanothai; Kukiattrakoon, Boonlert; Kedjarune-Leggat, Ureporn

    2011-01-01

    The aim of this study was to investigate the effect of acidic agents on surface roughness and characteristics of four restorative materials. Fifty-two discs were created from each restorative material: metal-reinforced glass ionomer cement (Ketac-S), resin-modified glass ionomer cement (Fuji II LC), resin composite (Filtek Z250), and amalgam (Valiant-PhD); each disc was 12 mm in diameter and 2.5 mm thick. The specimens were divided into four subgroups (n=13) and immersed for 168 hours in four storage media: deionized water (control); citrate buffer solution; green mango juice; and pineapple juice. Surface roughness measurements were performed with a profilometer, both before and after storage media immersion. Surface characteristics were examined using scanning electron microscopy (SEM). Statistical significance among each group was analyzed using two-way repeated ANOVA and Tukey's tests. Ketac-S demonstrated the highest roughness changes after immersion in acidic agents (p<0.05), followed by Fuji II LC. Valiant-PhD and Filtek Z250 illustrated some minor changes over 168 hours. The mango juice produced the greatest degradation effect of all materials tested (p<0.05). SEM photographs demonstrated gradual surface changes of all materials tested after immersions. Of the materials evaluated, amalgam and resin composite may be the most suitable for restorations for patients with tooth surface loss. PMID:21903509

  10. Using NMR chemical shift imaging to monitor swelling and molecular transport in drug-loaded tablets of hydrophobically modified poly(acrylic acid): methodology and effects of polymer (in)solubility.

    PubMed

    Knöös, Patrik; Topgaard, Daniel; Wahlgren, Marie; Ulvenlund, Stefan; Piculell, Lennart

    2013-11-12

    A new technique has been developed using NMR chemical shift imaging (CSI) to monitor water penetration and molecular transport in initially dry polymer tablets that also contain small low-molecular weight compounds to be released from the tablets. Concentration profiles of components contained in the swelling tablets could be extracted via the intensities and chemical shift changes of peaks corresponding to protons of the components. The studied tablets contained hydrophobically modified poly(acrylic acid) (HMPAA) as the polymer component and griseofulvin and ethanol as hydrophobic and hydrophilic, respectively, low-molecular weight model compounds. The water solubility of HMPAA could be altered by titration with NaOH. In the pure acid form, HMPAA tablets only underwent a finite swelling until the maximum water content of the polymer-rich phase, as confirmed by independent phase studies, had been reached. By contrast, after partial neutralization with NaOH, the polyacid became fully miscible with water. The solubility of the polymer affected the water penetration, the polymer release, and the releases of both ethanol and griseofulvin. The detailed NMR CSI concentration profiles obtained highlighted the clear differences in the disintegration/dissolution/release behavior for the two types of tablet and provided insights into their molecular origin. The study illustrates the potential of the NMR CSI technique to give information of importance for the development of pharmaceutical tablets and, more broadly, for the general understanding of any operation that involves the immersion and ultimate disintegration of a dry polymer matrix in a solvent. PMID:24106807

  11. EDTA-insoluble, calcium-binding proteoglycan in bovine bone

    NASA Technical Reports Server (NTRS)

    Hashimoto, Y.; Lester, G. E.; Caterson, B.; Yamauchi, M.

    1995-01-01

    A calcium ion precipitable, trypsin-generated proteoglycan fragment has been isolated from the demineralized, EDTA-insoluble matrices of bone. The demineralized matrix was completely digested with trypsin, increasing concentrations of CaCl2 were added to the supernatant, and the resulting precipitates were analyzed. The amount of precipitate gradually increased with higher concentrations of calcium and was reversibly solubilized by EDTA. After molecular sieve and anion exchange chromatography, a proteoglycan-containing peak was obtained. Immunochemical analysis showed that this peak contained chondroitin 4-sulfate and possibly keratan sulfate. Amino acid analysis showed that this proteoglycan contained high amounts of aspartic acid/asparagine (Asx), serine (Ser), glutamic acid/glutamine (Glx), proline (Pro), and glycine (Gly); however, it contained little leucine (Leu) which suggests that it is not a member of the leucine-rich small proteoglycan family. In addition, significant amounts of phosphoserine (P-Ser) and hydroxyproline (Hyp) were identified in hydrolysates of this fraction. A single band (M(r) 59 kDa) was obtained on SDS-PAGE that stained with Stains-all but not with Coomassie Brilliant Blue R-250. If bone powder was trypsinized prior to demineralization, this proteoglycan-containing fraction was not liberated. Collectively, these results indicate that a proteoglycan occurs in the demineralized matrix that is precipitated with CaCl2 and is closely associated with both mineral and collagen matrices. Such a molecule might facilitate the structural network for the induction of mineralization in bone.

  12. Potential SSP Perfluorooctanoic Acid Related Fluoropolymer Materials Obsolescence

    NASA Technical Reports Server (NTRS)

    Segars, Matt G.

    2006-01-01

    The Shuttle Environmental Assurance Initiative (SEA) has identified a potential for the Space Shuttle Program (SSP) to incur materials obsolescence issues due to agreements between the fluoro-chemical industry and the United States Environmental Protection Agency (USEPA) to participate in a Global Stewardship Program for perfluorooctanoic acid (PFOA). This presentation will include discussions of the chemistry, regulatory drivers, affected types of fluoropolymer and fluoroelastomer products, timeline for reformulations, and methodology for addressing the issue. It will cover the coordination of assessment efforts with the International Space Station and Head Quarters Air Force Space Command, along with some examples of impacted materials. The presentation is directed at all members of the international aerospace community concerned with identifying potential environmentally driven materials obsolescence issues.

  13. Effects of acid fog and dew on materials. Final report

    SciTech Connect

    Mansfeld, F.; Henry, R.; Vijayakumar, R.

    1989-10-01

    Field exposure tests have been carried out in order to separate the effects of acidic fog on materials damage from those caused by rain, dew and natural weathering. The test sites were McKittrick and Visalia in the Central Valley and West Casitas Pass in Ventura County. The field tests have been supported by laboratory tests in which materials damage has been determined during exposure to carefully controlled fog water chemistry. Analysis of the field exposure results for galvanized steel and the paint samples shows that the corrosivity of the atmosphere at the three test sites have been very low. The result is confirmed by the ACRM data which show very low corrosion activity. Since corrosion rates were so low approaching those for natural weathering, it was not possible to determine the effects of acidic fog. Based on the aerometric data and the observed corrosion behavior, it is doubtful that acidic fog conditions prevailed for significant times during the exposure period of 1/87 - 3/88 at Visalia and McKittrick. The results of the laboratory tests show that exposure to HNO3 at low pH and to high pollutant concentration increased the corrosion rate of galvanized steel to over 10 micro m/year. Exposure to HNO3 caused serious corrosion damage to anodized aluminum and the paint.

  14. Lysosomal glycosidases in mouse peritoneal macrophages stimulated in vitro with soluble and insoluble glycans.

    PubMed

    Bøgwald, J; Johnson, E; Hoffman, J; Seljelid, R

    1984-04-01

    Mouse peritoneal macrophages stimulated with insoluble glycans in vitro release high amounts of acid hydrolases, N-acetyl-beta-D-glucosaminidase, beta-D-glucuronidase, and beta-D-galactosidase. The most potent of the stimulatory glycans is a beta-1,3-D-glucan isolated from yeast cell walls. Up to 50% of total enzyme activity was found in the medium after stimulation with this glycan for three days. Agarose, another insoluble glycan containing an alternating sequence of the disaccharide beta-1,3-D-galactose-alpha-1,4-3,6-anhydro-L-galactose units was less potent. The soluble beta-1,3-D-glucan laminaran, which also contains small amounts of mannitol, was not able to induce release of acid glycosidases from macrophages. The release was independent of serum since macrophages cultured under serum-free conditions showed nearly the same pattern of enzyme activities, both in the cells and media. There was no increased release of the acid hydrolase alpha-D-mannosidase after stimulation with the insoluble beta-1,3-D-glucan for three days. The release of the lysosomal glycosidases was not due to cell death, since only small amounts of the cytoplasmic enzyme lactate dehydrogenase were found in the culture media. Insoluble polystyrene latex particles were not able to stimulate mouse macrophages to release lysosomal glycosidases. Tritiated glycans (amylose, dextran, laminaran, the insoluble beta-1,3-D-glucan, and agarose) and the p-nitrophenyl-glycopyranoside derivatives were used as substrates to investigate whether the macrophages contained or released glucanases capable of degrading alpha-1,4-D-glucans, alpha-1-6-D-glucans, beta-1,3-D-glucans, and agarose respectively. We conclude that the glycans were not degraded in macrophage cultures during the time period tested nor were the enzymes induced in macrophages by the glycans during in vitro culture for seven days. PMID:6584526

  15. Relationship of Enhanced Butyrate Production by Colonic Butyrate-Producing Bacteria to Immunomodulatory Effects in Normal Mice Fed an Insoluble Fraction of Brassica rapa L.

    PubMed

    Tanaka, Sachi; Yamamoto, Kana; Yamada, Kazuki; Furuya, Kanon; Uyeno, Yutaka

    2016-05-01

    This study was performed to determine the effects of feeding a fiber-rich fraction of Brassica vegetables on the immune response through changes in enteric bacteria and short-chain fatty acid (SCFA) production in normal mice. The boiled-water-insoluble fraction of Brassica rapa L. (nozawana), which consists mainly of dietary fiber, was chosen as a test material. A total of 31 male C57BL/6J mice were divided into two groups and housed in a specific-pathogen-free facility. The animals were fed either a control diet or the control diet plus the insoluble B. rapa L. fraction for 2 weeks and sacrificed to determine microbiological and SCFA profiles in lower-gut samples and immunological molecules. rRNA-based quantification indicated that the relative population of Bacteroidetes was markedly lower in the colon samples of the insoluble B. rapa L. fraction-fed group than that in the controls. Populations of the Eubacterium rectale group and Faecalibacterium prausnitzii, both of which are representative butyrate-producing bacteria, doubled after 2 weeks of fraction intake, accompanying a marginal increase in the proportion of colonic butyrate. In addition, feeding with the fraction significantly increased levels of the anti-inflammatory cytokine interleukin-10 (IL-10) and tended to increase splenic regulatory T cell numbers but significantly reduced the population of cells expressing activation markers. We demonstrated that inclusion of the boiled-water-insoluble fraction of B. rapa L. can alter the composition of the gut microbiota to decrease the numbers of Bacteroidetes and to increase the numbers of butyrate-producing bacteria, either of which may be involved in the observed shift in the production of splenic IL-10. PMID:26921420

  16. Immobilization of EAFD heavy metals using acidic materials.

    PubMed

    Mitrakas, Manassis G; Sikalidis, Constantinos A; Karamanli, Theoktisti P

    2007-03-01

    This study was undertaken to determine the chemical and leaching characteristics of the Electric Arc Furnace Dust (EAFD) generated by a Greek plant and to investigate various acidic materials efficiency on the EAFD stabilization. In order to investigate how [OH(-)] neutralization influences EAFD heavy metals leachability, Na HCO3(-), HNO3 and H3PO4 were used as acidic materials. The concentration of Pb in leachate was found between 40 and 3.7 x 10(3) mg Pb/kg of EAFD, exceeding in all EAFD samples the maximum acceptable limit (MAL) 25 mg/kg for landfill disposal. Neutralization of [OH(-)] with HCO3(-) decreased Pb concentration in leachate at 350 mg Pb/kg of EAFD, while excess over a stoichiometry in HCO3(-) addition increased leachability of Pb, Cd, Cr, Cu as well as F. Using HNO3 as an acidic material decreased leachability of almost all the parameters concerning the EC directive 33/19-01-2003 in a pH value up to 7.2, in exception of Zn. Zinc leachability showed a U shape curve as a function of pH value. The concentration of Zn was minimized in a concentration lower than 1 mg Zn/kg EAFD in a pH range 10.5 to 9 and exceeded the MAL 90 mg/kg at a pH value 7.2. However, the major disadvantage of HNO3 was proved to be its leachability, since NO3(-) concentration in leachate was equal to HNO3 dose. H3PO4 was found the most promising acidic material for the chemical immobilization of heavy metals, since it decreased their leachability in a concentration significantly lower than MAL at a pH value up to 7.1. Finally, the concentration of Cl(-) ranged between 18 and 33 x 10(3) mg Cl(-)/kg EAFD exceeding in all EAFD samples the MAL 17 x 10(3) mg/kg. This high concentration of Cl(-) is attributed to the scrap and it could be reduced only by modification of its composition. PMID:17365324

  17. DEVELOPMENT OF AN INSOLUBLE SALT SIMULANT TO SUPPORT ENHANCED CHEMICAL CLEANING TESTS

    SciTech Connect

    Eibling, R

    2008-05-23

    The closure process for high level waste tanks at the Savannah River Site will require dissolution of the crystallized salts that are currently stored in many of the tanks. The insoluble residue from salt dissolution is planned to be removed by an Enhanced Chemical Cleaning (ECC) process. Development of a chemical cleaning process requires an insoluble salt simulant to support evaluation tests of different cleaning methods. The Process Science and Engineering section of SRNL has been asked to develop an insoluble salt simulant for use in testing potential ECC processes (HLE-TTR-2007-017). An insoluble salt simulant has been developed based upon the residues from salt dissolution of saltcake core samples from Tank 28F. The simulant was developed for use in testing SRS waste tank chemical cleaning methods. Based on the results of the simulant development process, the following observations were developed: (1) A composition based on the presence of 10.35 grams oxalate and 4.68 grams carbonate per 100 grams solids produces a sufficiently insoluble solids simulant. (2) Aluminum observed in the solids remaining from actual waste salt dissolution tests is probably precipitated from sodium aluminate due to the low hydroxide content of the saltcake. (3) In-situ generation of aluminum hydroxide (by use of aluminate as the Al source) appears to trap additional salts in the simulant in a manner similar to that expected for actual waste samples. (4) Alternative compositions are possible with higher oxalate levels and lower carbonate levels. (5) The maximum oxalate level is limited by the required Na content of the insoluble solids. (6) Periodic mixing may help to limit crystal growth in this type of salt simulant. (7) Long term storage of an insoluble salt simulant is likely to produce a material that can not be easily removed from the storage container. Production of a relatively fresh simulant is best if pumping the simulant is necessary for testing purposes. The insoluble

  18. Adsorption of Ions at Uncharged Insoluble Monolayers.

    PubMed

    Peshkova, Tatyana V; Minkov, Ivan L; Tsekov, Roumen; Slavchov, Radomir I

    2016-09-01

    A method is proposed for the experimental determination of the adsorption of inorganic electrolytes at a surface covered with insoluble surfactant monolayer. This task is complicated by the fact that the change of the salt concentration alters both chemical potentials of the electrolyte and the surfactant. Our method resolves the question by combining data for the surface pressure versus area of the monolayer at several salt concentrations with data for the equilibrium spreading pressure of crystals of the surfactant (used to fix a standard state). We applied the method to alcohols spread at the surface of concentrated halide solutions. The measured salt adsorption is positive and has nonmonotonic dependence on the area per surfactant molecule. For the liquid expanded film, depending on the concentration, there is one couple of ions adsorbed per each 3-30 surfactant molecules. We analyzed which ion, the positive or the negative, stands closer to the surface, by measuring the effect of NaCl on the Volta potential of the monolayer. The potentiometric data suggest that Na(+) is specifically adsorbed, while Cl(-) remains in the diffuse layer, i.e., the surface is positively charged. The observed reverse Hofmeister series of the adsorptions of NaF, NaCl, and NaBr suggests the same conclusion holds for all these salts. The force that causes the adsorption of Na(+) seems to be the interaction of the ion with the dipole moment of the monolayer. PMID:27529571

  19. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Insoluble glucose isomerase enzyme preparations... enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production of... additional requirements for enzyme preparations in the Food Chemicals Codex, 3d Ed. (1981), p. 107, which...

  20. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Insoluble glucose isomerase enzyme preparations... enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production of... additional requirements for enzyme preparations in the Food Chemicals Codex, 3d Ed. (1981), p. 107, which...

  1. 1,3-Diethyl-2-thiobarbituric acid as an alternative coinitiator for acidic photopolymerizable dental materials.

    PubMed

    Münchow, Eliseu A; Valente, Lisia L; Peralta, Sonia L; Fernández, María Raquel; Lima, Giana da S; Petzhold, Cesar L; Piva, Evandro; Ogliari, Fabrício A

    2013-10-01

    The ethyl-4-dimethylaminobenzoate (EDAB) is widely used as a coinitiator of the camphorquinone (CQ), but in acidic circumstances it might present some instability, reducing the polymerization efficiency of the material. Considering this, new coinitiators are being evaluated. Hence, this study evaluated the kinetic of polymerization (KP), the degree of conversion (DC), and the rate of polymerization (RP ) of experimental resin adhesives containing 1,3-diethyl-2-thiobarbituric acid (TBA) as a coinitiator of the CQ. The experimental monomeric blend was prepared with bisphenol A glycidyl dimethacrylate, 2-hydroxyethyl methacrylate, and acidic monomers. CQ was added at 1 mol % as photoinitiator. Six groups were formulated: four containing concentrations of 0.1, 0.5, 1, and 2 mol % of TBA, one without coinitiator, and the last one containing 1 mol % of EDAB (control group). The KP and the RP were performed using real-time Fourier Transform infrared spectroscopy. The group without coinitiator has not formed a polymer, whereas the addition of TBA resulted in the conversion of monomers in polymer. The DC of the adhesives was as higher as the increase in the TBA content. The group with 2 mol % of TBA presented improved DC and reactivity (RP ) than the other groups and the control one. Hence, the TBA has performed as a coinitiator of the CQ for the radical polymerization of methacrylate resin adhesives and it has improved the DC and the reactivity of the materials. Thus, it is a potential coinitiator for the photopolymerization of dental materials. PMID:23564499

  2. Solubilization of insoluble inorganic phosphate by Burkholderia cepacia DA23 isolated from cultivated soil

    PubMed Central

    Song, Ok-Ryul; Lee, Seung-Jin; Lee, Yong-Seok; Lee, Sang-Cheol; Kim, Keun-Ki; Choi, Yong-Lark

    2008-01-01

    A mineral phosphate solubilizing bacterium, Burkholderia cepacia DA23 has been isolated from cultivated soils. Phosphate-solubilizing activities of the strain against three types of insoluble phosphate were quantitatively determined. When 3% of glucose concentration was used for carbon source, the strain had a marked mineral phosphate-solubilizing activity. Mineral phosphate solubilization was directly related to the pH drop by the strain. Analysis of the culture medium by high pressure liquid chromatography identified gluconic acid as the main organic acid released by Burkholderia cepacia DA23. Gluconic acid production was apparently the result of the glucose dehydrogenase activity and glucose dehydrogenase was affected by phosphate regulation. PMID:24031195

  3. Insoluble coatings for Stirling engine heat pipe condenser surfaces

    NASA Astrophysics Data System (ADS)

    Dussinger, Peter M.

    1993-09-01

    The work done by Thermacore, Inc., Lancaster, Pennsylvania, for the Phase 1, 1992 SBIR National Aeronautics and Space Administration Contract, 'Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces' is described. The work was performed between January 1992 and July 1992. Stirling heat engines are being developed for electrical power generation use on manned and unmanned earth orbital and planetary missions. Dish Stirling solar systems and nuclear reactor Stirling systems are two of the most promising applications of the Stirling engine electrical power generation technology. The sources of thermal energy used to drive the Stirling engine typically are non-uniform in temperature and heat flux. Liquid metal heat pipe receivers are used as thermal transformers and isothermalizers to deliver the thermal energy at a uniform high temperature to the heat input section of the Stirling engine. The use of a heat pipe receiver greatly enhances system efficiency and potential life span. One issue that is raised during the design phase of heat pipe receivers is the potential solubility corrosion of the Stirling engine heat input section by the liquid metal working fluid. This Phase 1 effort initiated a program to evaluate and demonstrate coatings, applied to nickel based Stirling engine heater head materials, that are practically 'insoluble' in sodium, potassium, and NaK. This program initiated a study of nickel aluminide as a coating and developed and demonstrated a heat pipe test vehicle that can be used to test candidate materials and coatings. Nickel 200 and nickel aluminide coated Nickel 200 were tested for 1000 hours at 800 C at a condensation heat flux of 25 W/sq cm. Subsequent analyses of the samples showed no visible sign of solubility corrosion of either coated or uncoated samples. The analysis technique, photomicrographs at 200X, has a resolution of better than 2.5 microns (.0001 in). The results indicate that the heat pipe environment is not directly

  4. Insoluble coatings for Stirling engine heat pipe condenser surfaces

    NASA Technical Reports Server (NTRS)

    Dussinger, Peter M.

    1993-01-01

    The work done by Thermacore, Inc., Lancaster, Pennsylvania, for the Phase 1, 1992 SBIR National Aeronautics and Space Administration Contract, 'Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces' is described. The work was performed between January 1992 and July 1992. Stirling heat engines are being developed for electrical power generation use on manned and unmanned earth orbital and planetary missions. Dish Stirling solar systems and nuclear reactor Stirling systems are two of the most promising applications of the Stirling engine electrical power generation technology. The sources of thermal energy used to drive the Stirling engine typically are non-uniform in temperature and heat flux. Liquid metal heat pipe receivers are used as thermal transformers and isothermalizers to deliver the thermal energy at a uniform high temperature to the heat input section of the Stirling engine. The use of a heat pipe receiver greatly enhances system efficiency and potential life span. One issue that is raised during the design phase of heat pipe receivers is the potential solubility corrosion of the Stirling engine heat input section by the liquid metal working fluid. This Phase 1 effort initiated a program to evaluate and demonstrate coatings, applied to nickel based Stirling engine heater head materials, that are practically 'insoluble' in sodium, potassium, and NaK. This program initiated a study of nickel aluminide as a coating and developed and demonstrated a heat pipe test vehicle that can be used to test candidate materials and coatings. Nickel 200 and nickel aluminide coated Nickel 200 were tested for 1000 hours at 800 C at a condensation heat flux of 25 W/sq cm. Subsequent analyses of the samples showed no visible sign of solubility corrosion of either coated or uncoated samples. The analysis technique, photomicrographs at 200X, has a resolution of better than 2.5 microns (.0001 in). The results indicate that the heat pipe environment is not directly

  5. Insoluble layer deposition and dilatational rheology at a microscale spherical cap interface.

    PubMed

    Kotula, Anthony P; Anna, Shelley L

    2016-08-17

    The dilatational properties of insoluble monolayers are important for understanding the mechanics of biological systems and consumer products, but isolating the dilatational response of an interface is challenging due to the difficulties in separating dilatation from shear and other deformation modes. Oscillations of a microscale bubble radius are useful for generating purely dilatational flows, but the current deposition methods for insoluble layers onto fluid interfaces are not easily scaled down. In this paper, we describe a miscible solvent exchange procedure for generating insoluble layers at an air-water interface pinned at the tip of a capillary tens of micrometers in diameter. We show that the amount of surfactant adsorbed at the interface can be controlled by the initial concentration dissolved in isopropanol (the starting solvent) and the volumetric flow rate of solvent exchange. Surface pressure-area isotherms and dilatational moduli are measured concurrently for three insoluble surfactants: palmitic acid (PA), dimyristoylphosphatidylcholine (DMPC) and dipalmitoylphosphatidylcholine (DPPC). The isotherms measured on the microscale interface compare well with previous experiments performed on a Langmuir trough. However, the magnitudes of the dilatational moduli differ from those measured on either Langmuir trough or pendant drop apparatuses. Several possible reasons for the observed differences are discussed. A comparison of the dilatational modulus with the Gibbs elasticity is used to determine the presence of dilatational extra stresses at the interface. The isotherm and dilatational modulus of the insoluble component of the industrial surfactant Tween 80 are measured using this approach. The methods developed here also open the possibility for future study of the important role of finite size effects on microstructure formation and the resulting interfacial mechanics. PMID:27478885

  6. Iron oxohydroxide-polyacrylic acid magnetic composite materials

    NASA Astrophysics Data System (ADS)

    Mata-Zamora, M. E.; Arriola, H.; Nava, N.; Saniger, J. M.

    1996-08-01

    Powdered nanometer-sized precipitates of Fe(II)Fe(III) 2O x(OH) y were obtained by reacting solutions of ferrous-ferric salts with a Fe(III)/Fe(II) ratio < 2, with an excess of ammonium hydroxide. These precipitates were then mixed at room temperature with a solution of polyacrylic acid (PAA) in order to obtain a composite material. The XRD analysis showed that the iron oxohydroxide precipitates, with an average size around 10 nm, were crystalline and had a spinel structure resembling to either magnetite or maghemite. The Mössbauer spectra of the iron oxohydroxide particles presented a major magnetic phase with the double Zeeman splitting characteristic of magnetite and a minor paramagnetic phase probably originated by the nanometer size of the particles. Its structure was found to correspond to a disordered spinel, as result of the analysis of the intrinsic magnetic field and its splitting parameters. The composite material PAA-Fe(II)Fe(III) 2O x(OH) y presented a diffractogram close to the original oxohydroxide, but its Mössbauer spectrum showed a major paramagnetic phase. This change was explained as a consequence of the chemical coordination of the nanometer sized iron oxohydroxides particles with the PAA carboxylate groups.

  7. Study of inlet materials for sampling atmospheric nitric acid

    SciTech Connect

    Neuman, J.A.; Huey, L.G.; Ryerson, T.B.; Fahey, D.W. |

    1999-04-01

    The adsorption of nitric acid (HNO{sub 3}) from a flowing gas stream is studied for a variety of wall materials to determine their suitability for use in atmospheric sampling instruments. Parts per billion level mixtures of HNO{sub 3} in synthetic air flow through tubes of different materials such that >80% of the molecules interact with the walls. A chemical ionization mass spectrometer with a fast time response and high sensitivity detects HNO{sub 3} that is not adsorbed on the tube walls. Less than 5% of available HNO{sub 3} is adsorbed on Teflon fluoropolymer tubing after 1 min of HNO{sub 3} exposure, whereas >70% is lost on walls made of stainless steel, glass, fused silica, aluminum, nylon, silica-steel, and silane-coated glass. Glass tubes exposed to HNO{sub 3} on the order of hours passivate with HNO{sub 3} adsorption dropping to zero. The adsorption of HNO{sub 3} on PFA Teflon tubing (PFA) is nearly temperature-independent from 10 to 80 C, but below {minus}10 C nearly all HNO{sub 3} that interacts with PFA is reversibly adsorbed. In ambient and synthetic air, humidity increases HNO{sub 3} adsorption. The results suggest that Teflon at temperatures above 10 C is an optimal choice for inlet surfaces used for in situ measurements of HNO{sub 3} in the ambient atmosphere.

  8. An Unique On-line Method to Infer Black Carbonaceous contributions to Water-Insoluble Aerosol Compositions

    NASA Astrophysics Data System (ADS)

    Asa-Awuku, A. A.; Short, D.

    2013-12-01

    Particle number, size, and composition information is important for constraining aerosol effects on air quality, climate, and health. The composition of particles, especially from vehicular sources, may contain insoluble material that may modify particle nucleating properties. Changes in fuel properties are known to modify criteria pollutants and particulate matter mass, size, and number. In this work we summarize findings as they pertain to the water-soluble and insoluble composition of particles. In field measuremnts and controlled laboratory studies, a water-based condensation particle counter (CPC) and a butanol-based CPC measure particle number concentration. Both instruments were coupled with a Scanning Mobility Particle Sizer (SMPS) and particle number and size data were recorded. Real time particle insoluble mass fractions are estimated with the SMPS data sets; theoretical soluble fractions are calculated from ideal hygroscopicty single parameter values. This is the first time that this experimental method has been employed and used to infer online insoluble fractions. The results show that near-roadway emissions contain water insoluble and black carbon components. We will discuss the contributions of the organic component to the water-insoluble nature. Time permitting, the emissions of different ethanol and butanol gasoline blends are also explored for light-duty vehicles on a light-duty dynaometer chassis. Laboratory results indicate that soluble vehicular components are strongly correlated with vehicle driving conditions.

  9. Cytotoxicity of corrosion products of degradable Fe-based stents: relevance of pH and insoluble products.

    PubMed

    Fagali, Natalia S; Grillo, Claudia A; Puntarulo, Susana; Fernández Lorenzo de Mele, Mónica A

    2015-04-01

    Fe-based biodegradable metallic materials (Fe-BMMs) have been proposed for cardiovascular applications and are expected to disappear via corrosion after an appropriate period. However, in vivo studies showed that Fe ions release leads to accumulation of orange and brownish insoluble products at the biomaterial/cell interface. As an additional consequence, sharp changes in pH may affect the biocompatibility of these materials. In the present work, the experimental protocols were designed with the aim of evaluating the relative importance that these factors have on biocompatibility evaluation of BMMs. Mitochondrial activity (MTT assay) and thiobarbituric acid reactive substances (TBARS) assay on mammalian cells, exposed to 1-5 mM of added Fe3+ salt, were assessed and compared with results linked exclusively to pH effects. Soluble Fe concentration in culture medium and intracellular Fe content were also determined. The results showed that: (i) mitochondrial activity was affected by pH changes over the entire range of concentrations of added Fe3+ assayed, (ii) at the highest added Fe3+ concentrations (≥3 mM), precipitation was detected and the cells were able to incorporate the precipitate, that seems to be linked to cell damage, (iii) the extent of precipitation depends on the Fe/protein concentration ratio; and (iv) lipid peroxidation products were detected over the entire range of concentrations of added Fe3+. Hence, a new approach opens in the biocompatibility evaluation of Fe-based BMMs, since the cytotoxicity would not be solely a function of released (and soluble) ions but of the insoluble degradation product amount and the pH falling at the biomaterial/cell interface. The concentration of Fe-containing products at the interface depends on diffusional conditions in a very complex way that should be carefully analyzed in the future. PMID:25797480

  10. Dissolving mechanism of strain P17 on insoluble phosphorus of yellow-brown soil

    PubMed Central

    Chuan-qing, Zhong; Guang-xiang, Cao; Wei-yi, Huang; Xing-she, Luan; Yi-fei, Yang

    2014-01-01

    Strain P17 was a bacterial strain identified as Bacillus megaterium isolated from ground accumulating phosphate rock powder. The fermentation broth of strain P17 and the yellow-brown soil from Nanjing Agricultural University garden were collected to conduct this study. The simulation of fixed insoluble phosphorous forms after applying calcium superphosphate into yellow-brown soil was performed in pots, while available P and total P of soil were extremely positive correlative with those of groundwater. Then the dissolving effect of strain P17 on insoluble P of yellow-brown soil was studied. Results showed that Bacillus megaterium strain P17 had notable solubilizing effect on insoluble phosphates formed when too much water-soluble phosphorous fertilizer used. During 100 days after inoculation, strain P17 was dominant. Until the 120th day, compared with water addition, available P of strain P17 inoculation treated soil increased by 3 times with calcium superphosphate addition. Besides available P, pH, activity of acid and alkaline phosphatase and population of P-solubilizing microbes were detected respectively. P-solubilizing mechanism of P-solubilizing bacteria strain P17 seems to be a synergetic effect of pH decrease, organic acids, phosphatase, etc. PMID:25477929

  11. Dissolving mechanism of strain P17 on insoluble phosphorus of yellow-brown soil.

    PubMed

    Zhong, Chuan-qing; Cao, Guang-xiang; Huang, Wei-yi; Luan, Xing-she; Yang, Yi-fei

    2014-01-01

    Strain P17 was a bacterial strain identified as Bacillus megaterium isolated from ground accumulating phosphate rock powder. The fermentation broth of strain P17 and the yellow-brown soil from Nanjing Agricultural University garden were collected to conduct this study. The simulation of fixed insoluble phosphorous forms after applying calcium superphosphate into yellow-brown soil was performed in pots, while available P and total P of soil were extremely positive correlative with those of groundwater. Then the dissolving effect of strain P17 on insoluble P of yellow-brown soil was studied. Results showed that Bacillus megaterium strain P17 had notable solubilizing effect on insoluble phosphates formed when too much water-soluble phosphorous fertilizer used. During 100 days after inoculation, strain P17 was dominant. Until the 120th day, compared with water addition, available P of strain P17 inoculation treated soil increased by 3 times with calcium superphosphate addition. Besides available P, pH, activity of acid and alkaline phosphatase and population of P-solubilizing microbes were detected respectively. P-solubilizing mechanism of P-solubilizing bacteria strain P17 seems to be a synergetic effect of pH decrease, organic acids, phosphatase, etc. PMID:25477929

  12. Erosion by acid rain, accelerating the tracking of polystyrene insulating material

    NASA Astrophysics Data System (ADS)

    Wang, X.; Chen, L.; Yoshimura, N.

    2000-05-01

    Because outdoor insulating materials in service are subjected to numerous wet and dry cycles, it is necessary to establish their performance in acid rain. The erosion effect of acid rain on atactic polystyrene insulating material is investigated using accelerated ageing by artificial acid rain. The degradation mechanisms of material structure and tracking resistance are discussed. The experimental results reported here show that the erosion of acid rain causes the degradation of the surface chemical and physical structures of polystyrene (PS) material so that the surface conductivity of aged material increases. Under electrical stress, the surface discharge current increases, and the local surface is deteriorated so that the tracking is initiated earlier and the material rapidly fails. The degradation rate of PS material in acid rain varies as function of the ion concentration, pH and conductivity of acid rain. Only the severe acid rain of high acidity and conductivity can exert an influence on PS insulating material. The concentration of actual rainwater is insufficient to lead to obvious erosion on PS insulation. PS insulation could resist on the erosion of normal acid rainwater. Even though clear degradation occurs with strong acid rain, PS could behave quite well in mild acid rain conditions.

  13. Soluble and insoluble signals sculpt osteogenesis in angiogenesis.

    PubMed

    Ripamonti, Ugo

    2010-05-26

    The basic tissue engineering paradigm is tissue induction and morphogenesis by combinatorial molecular protocols whereby soluble molecular signals are combined with insoluble signals or substrata. The insoluble signal acts as a three-dimensional scaffold for the initiation of de novo tissue induction and morphogenesis. The osteogenic soluble molecular signals of the transforming growth factor-β (TGF-β) supergene family, the bone morphogenetic/osteogenic proteins (BMPs/OPs) and, uniquely in the non-human primate Papio ursinus (P. ursinus), the three mammalian TGF-β isoforms induce bone formation as a recapitulation of embryonic development. In this paper, I discuss the pleiotropic activity of the BMPs/OPs in the non-human primate P. ursinus, the induction of bone by transitional uroepithelium, and the apparent redundancy of molecular signals initiating bone formation by induction including the three mammalian TGF-β isoforms. Amongst all mammals tested so far, the three mammalian TGF-β isoforms induce endochondral bone formation in the non-human primate P. ursinus only. Bone tissue engineering starts by erecting scaffolds of biomimetic biomaterial matrices that mimic the supramolecular assembly of the extracellular matrix of bone. The molecular scaffolding lies at the hearth of all tissue engineering strategies including the induction of bone formation. The novel concept of tissue engineering is the generation of newly formed bone by the implantation of "smart" intelligent biomimetic matrices that per se initiate the ripple-like cascade of bone differentiation by induction without exogenously applied BMPs/OPs of the TGF-β supergene family. A comprehensive digital iconographic material presents the modified tissue engineering paradigm whereby the induction of bone formation is initiated by intelligent smart biomimetic matrices that per se initiate the induction of bone formation without the exogenous application of the soluble osteogenic molecular signals. The

  14. Structural and physico-chemical properties of insoluble rice bran fiber: effect of acid–base induced modifications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structural modifications of insoluble rice bran fiber (IRBF) by sequential regimes of sulphuric acid (H2SO4) and their effects on the physicochemical attributes were studied. The increment of H2SO4 concentration resulted in decreased water holding capacity that ultimately enhanced the oil bindin...

  15. 40 CFR 227.12 - Insoluble wastes.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... benthic, demersal, or pelagic biota. (b) Persistent inert synthetic or natural materials which may float... ocean only when they have been processed in such a fashion that they will sink to the bottom and...

  16. Acid Precipitation Awareness Curriculum Materials in the Life Sciences.

    ERIC Educational Resources Information Center

    Stubbs, Harriett S.

    1983-01-01

    Provides an outline of course content for acid precipitation and two acid rain activities (introduction to pH and effects of acid rain on an organism). Information for obtaining 20 additional activities as well as an information packet containing booklets, pamphlets, and articles are also provided. (JN)

  17. Materials study supporting thermochemical hydrogen cycle sulfuric acid decomposer design

    NASA Astrophysics Data System (ADS)

    Peck, Michael S.

    Increasing global climate change has been driven by greenhouse gases emissions originating from the combustion of fossil fuels. Clean burning hydrogen has the potential to replace much of the fossil fuels used today reducing the amount of greenhouse gases released into the atmosphere. The sulfur iodine and hybrid sulfur thermochemical cycles coupled with high temperature heat from advanced nuclear reactors have shown promise for economical large-scale hydrogen fuel stock production. Both of these cycles employ a step to decompose sulfuric acid to sulfur dioxide. This decomposition step occurs at high temperatures in the range of 825°C to 926°C dependent on the catalysis used. Successful commercial implementation of these technologies is dependent upon the development of suitable materials for use in the highly corrosive environments created by the decomposition products. Boron treated diamond film was a potential candidate for use in decomposer process equipment based on earlier studies concluding good oxidation resistance at elevated temperatures. However, little information was available relating the interactions of diamond and diamond films with sulfuric acid at temperatures greater than 350°C. A laboratory scale sulfuric acid decomposer simulator was constructed at the Nuclear Science and Engineering Institute at the University of Missouri-Columbia. The simulator was capable of producing the temperatures and corrosive environments that process equipment would be exposed to for industrialization of the sulfur iodide or hybrid sulfur thermochemical cycles. A series of boron treated synthetic diamonds were tested in the simulator to determine corrosion resistances and suitability for use in thermochemical process equipment. These studies were performed at twenty four hour durations at temperatures between 600°C to 926°C. Other materials, including natural diamond, synthetic diamond treated with titanium, silicon carbide, quartz, aluminum nitride, and Inconel

  18. Hydrofluoric Acid Corrosion Study of High-Alloy Materials

    SciTech Connect

    Osborne, P.E.

    2002-09-11

    A corrosion study involving high-alloy materials and concentrated hydrofluoric acid (HF) was conducted in support of the Molten Salt Reactor Experiment Conversion Project (CP). The purpose of the test was to obtain a greater understanding of the corrosion rates of materials of construction currently used in the CP vs those of proposed replacement parts. Results of the study will help formulate a change-out schedule for CP parts. The CP will convert slightly less than 40 kg of {sup 233}U from a gas (UF{sub 6}) sorbed on sodium fluoride pellets to a more stable oxide (U{sub 3}O{sub 8}). One by-product of the conversion is the formation of concentrated HF. Six moles of highly corrosive HF are produced for each mole of UF{sub 6} converted. This acid is particularly corrosive to most metals, elastomers, and silica-containing materials. A common impurity found in {sup 233}U is {sup 232}U. This impurity isotope has several daughters that make the handling of the {sup 233}U difficult. Traps of {sup 233}U may have radiation fields of up to 400 R at contact, a situation that makes the process of changing valves or working on the CP more challenging. It is also for this reason that a comprehensive part change-out schedule must be established. Laboratory experiments involving the repeated transfer of HF through 1/2-in. metal tubing and valves have proven difficult due to the corrosivity of the HF upon contact with all wetted parts. Each batch of HF is approximately 1.5 L of 33 wt% HF and is transferred most often as a vapor under vacuum and at temperatures of up to 250 C. Materials used in the HF side of the CP include Hastelloy C-276 and Monel 400 tubing, Haynes 230 and alloy C-276 vessels, and alloy 400 valve bodies with Inconel (alloy 600) bellows. The chemical compositions of the metals discussed in this report are displayed in Table 1. Of particular concern are the almost 30 vendor-supplied UG valves that have the potential for exposure to HF. These valves have been

  19. 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

  20. 13C NMR spectroscopy of the insoluble carbon of carbonaceous chondrites

    NASA Technical Reports Server (NTRS)

    Cronin, J. R.; Pizzarello, S.; Frye, J. S.

    1987-01-01

    13C NMR spectra have been obtained of the insoluble carbon residues resulting from HF-digestion of three carbonaceous chondrites, Orgueil (C1), Murchison (CM2), and Allende (CV3). Spectra obtained using the cross polarization magic-angle spinning technique show two major features attributable respectively to carbon in aliphatic/olefinic structures. The spectrum obtained from the Allende sample was weak, presumably as a consequence of its low hydrogen content. Single pulse excitation spectra, which do not depend on 1H-13C polarization transfer for signal enhancement were also obtained. These spectra, which may be more representative of the total carbon in the meteorite samples, indicate a greater content of carbon in aromatic/olefinic structures. These results suggest that extensive polycyclic aromatic sheets are important structural features of the insoluble carbon of all three meteorites. The Orgueil and Murchison materials contain additional hydrogenated aromatic/olefinic and aliphatic groups.

  1. Organic Analysis in Miller Range 090657 and Buckley Island 10933 CR2 Chondrites: Part 1 In-Situ Observation of Carbonaceous Material

    NASA Technical Reports Server (NTRS)

    Cao, T.; Nakamura-Messenger, K.; Berger, E. L.; Burton, A. S.; Messenger, S.; Clemett, S. J.

    2016-01-01

    Primitive carbonaceous chondrites contain a wide variety of organic material, ranging from soluble discrete molecules to insoluble unstructured kerogen-like component as well as structured nano-globules of macromolecular carbon. The relationship between the soluble organic molecules, macromolecular organic material, and host minerals are poorly understood. Due to the differences in extractability of soluble and insoluble organic materials, the analysis methods for each differ and are often performed independently. The combination of soluble and insoluble analyses, when performed concurrently, can provide a wider understanding on spatial distribution, and elemental, structural and isotopic composition of organic material in primitive meteorites. Furthermore, they can provide broader perspective on how extraterrestrial organic ma-terials potentially contributed to the synthesis of life's essential compounds such as amino acids, sugar acids, activated phosphates and nucleobases.

  2. The potency-insolubility conundrum in pharmaceuticals: Mechanism and solution for hepatitis C protease inhibitors.

    PubMed

    Connelly, Patrick R; Snyder, Phillip W; Zhang, Yuegang; McClain, Brian; Quinn, Brian P; Johnston, Steve; Medek, Ales; Tanoury, Jerry; Griffith, James; Patrick Walters, W; Dokou, Eleni; Knezic, Dragutin; Bransford, Philip

    2015-01-01

    As compounds are optimized for greater potency during pharmaceutical discovery, their aqueous solubility often decreases, making them less viable as orally-administered drugs. To investigate whether potency and insolubility share a common origin, we examined the structural and thermodynamic properties of telaprevir, a sparingly soluble inhibitor of hepatitis C virus protease. Comparison of the hydrogen bond motifs in crystalline telaprevir with those present in the protease-telaprevir complex revealed striking similarities. Additionally, the thermodynamics of telaprevir dissolution closely resembles those of protein-ligand dissociation. Together, these findings point to a common origin of potency and insolubility rooted in particular amide-amide hydrogen bond patterns. The insolubility of telaprevir is shown by computational analysis to be caused by interactions in the crystal, not unfavorable hydrophobic hydration. Accordingly, competing out the particular amide-amide hydrogen bond motifs in crystalline telaprevir with 4-hydroxybenzoic acid yielded a co-crystalline solid with excellent aqueous dissolution and oral absorption. The analysis suggests a generalizable approach for identifying drug candidate compounds that either can or cannot be rendered orally bioavailable by alteration of their crystalline solid phases, in an approach that provides a pragmatic way to attain substantial enhancements in the success rate of drug discovery and development. PMID:25451684

  3. Improvement of thermostability and activity of Trichoderma reesei endo-xylanase Xyn III on insoluble substrates.

    PubMed

    Matsuzawa, Tomohiko; Kaneko, Satoshi; Yaoi, Katsuro

    2016-09-01

    Trichoderma reesei Xyn III, an endo-β-1,4-xylanase belonging to glycoside hydrolase family 10 (GH10), is vital for the saccharification of xylans in plant biomass. However, its enzymatic thermostability and hydrolytic activity on insoluble substrates are low. To overcome these difficulties, the thermostability of Xyn III was improved using random mutagenesis and directed evolution, and its hydrolytic activity on insoluble substrates was improved by creating a chimeric protein. In the screening of thermostable Xyn III mutants from a random mutagenesis library, we identified two amino acid residues, Gln286 and Asn340, which are important for the thermostability of Xyn III. The Xyn III Gln286Ala/Asn340Tyr mutant showed xylanase activity even after heat treatment at 60 °C for 30 min or 50 °C for 96 h, indicating a dramatic enhancement in thermostability. In addition, we found that the addition of a xylan-binding domain (XBD) to the C-terminal of Xyn III improved its hydrolytic activity on insoluble xylan. PMID:27138202

  4. Proteins of insoluble matrix of avian (gallus gallus) eggshell.

    PubMed

    Miksík, Ivan; Eckhardt, Adam; Sedláková, Pavla; Mikulikova, Katerina

    2007-01-01

    The protein composition of the insoluble avian eggshell matrix was studied. The determination of these proteins insoluble in water (EDTA-insoluble) was carried out using enzymatic cleavage followed by a high-performance liquid chromatography-mass spectrometry method. The influence of various enzymes on the protein splitting also was studied. The distribution of proteins depends on the type of layer (localization within the eggshell): ovocalyxin-32 was found mainly in the outer layer (the cuticle); ovocleidin-116 and 17 and ovocalyxin-36 were found throughout the whole eggshell, whereas ovalbumin was only found in the inner layer, the mammillary. The pigment (protoporphyrin IX) was mainly found in the cuticle and is incorporated into the protein network. PMID:17364661

  5. On the Maillard reaction of meteoritic amino acids

    NASA Astrophysics Data System (ADS)

    Kolb, Vera M.; Bajagic, Milica; Liesch, Patrick J.; Philip, Ajish; Cody, George D.

    2006-08-01

    We have performed the Maillard reaction of a series of meteoritic amino acids with sugar ribose under simulated prebiotic conditions, in the solid state at 65°C and at the room temperature. Many meteoritic amino acids are highly reactive with ribose, even at the room temperature. We have isolated high molecular weight products that are insoluble in water, and have studied their structure by the IR (infrared) and solid-state C-13 NMR (nuclear magnetic resonance) spectroscopic methods. The functional groups and their distribution were similar among these products, and were comparable to the previously isolated insoluble organic materials from the Maillard reaction of the common amino acids with ribose. In addition, there were some similarities with the insoluble organic material that is found on Murchison. Our results suggest that the Maillard products may contribute to the composition of the part of the insoluble organic material that is found on Murchison. We have also studied the reaction of sodium silicate solution with the Maillard mixtures, to elucidate the process by which the organic compounds are preserved under prebiotic conditions.

  6. Material compatibility evaluation for DWPF nitric-glycolic acid-literature review

    SciTech Connect

    Mickalonis, J.; Skidmore, E.

    2013-06-01

    Glycolic acid is being evaluated as an alternative for formic and nitric acid in the DWPF flowsheet. Demonstration testing and modeling for this new flowsheet has shown that glycolic acid and glycolate has a potential to remain in certain streams generated during the production of the nuclear waste glass. A literature review was conducted to assess the impact of glycolic acid on the corrosion of the materials of construction for the DWPF facility as well as facilities downstream which may have residual glycolic acid and glycolates present. The literature data was limited to solutions containing principally glycolic acid.

  7. Materials and methods for efficient lactic acid production

    DOEpatents

    Zhou, Shengde; Ingram, Lonnie O'Neal; Shanmugam, Keelnatham T.; Yomano, Lorraine; Grabar, Tammy B.; Moore, Jonathan C.

    2009-12-08

    The present invention provides derivatives of ethanologenic Escherichia coli K011 constructed for the production of lactic acid. The transformed E. coli of the invention are prepared by deleting the genes that encode competing pathways followed by a growth-based selection for mutants with improved performance. These transformed E. coli are useful for providing an increased supply of lactic acid for use in food and industrial applications.

  8. Materials and methods for efficient lactic acid production

    SciTech Connect

    Zhou, Shengde; Ingram, Lonnie O'Neal; Shanmugam, Keelnatham T; Yomano, Lorraine; Grabar, Tammy B; Moore, Jonathan C

    2013-04-23

    The present invention provides derivatives of Escherichia coli constructed for the production of lactic acid. The transformed E. coli of the invention are prepared by deleting the genes that encode competing pathways followed by a growth-based selection for mutants with improved performance. These transformed E. coli are useful for providing an increased supply of lactic acid for use in food and industrial applications.

  9. An oral controlled release system for ambroxol hydrochloride containing a wax and a water insoluble polymer.

    PubMed

    Chi, Na; Guo, Ju Hong; Zhang, Yu; Zhang, Wei; Tang, Xing

    2010-01-01

    This study was carried out to develop and optimize oral sustained-release formulations for Ambroxol hydrochloride matrix pellets using a combination of wax and water-insoluble polymer, glyceryl behenate (Compritol 888 ATO) and Ethylcellulose (EC(7 FP)). It involved three factors: the content of Compritol 888 ATO (X(1)), EC(7 FP) (X(2)), and the matrix formation methods (X(3)), as independent variables. The drug release percentages at 1, 2 and 4 h were the target responses and were restricted to 15-45% (Y(1)), 45-80% (Y(2)) and 80-100% (Y(3)), respectively. The final blend formulation prepared by extrusion spheronization, was achieved with 27.00% (w/w) Ambroxol hydrochloride, 48.70% (w/w) Compritol 888 ATO, and 24.30% (w/w) EC(7 Fp) with 40 degrees C for 12 h. Comparing the single matrix materials consisting of just the wax or water-insoluble in the complex matrix system containing wax and water-insoluble polymer, the release of the drug can be far more retarded, when the formulations have undergone the process of heat treatment. Furthermore, the combination of the two polymers, with flexible matrix formation methods, will offer a very promising way of producing matrix pellets instead of coated controlled-release pellets to meet various demands of drug release. PMID:19671037

  10. The effects of conditioning on meat collagen: Part 2-Direct biochemical evidence for proteolytic damage in insoluble perimysial collagen after conditioning.

    PubMed

    Stanton, C; Light, N

    1988-01-01

    The effect of proteolytic attack on unwashed and 6 M urea washed bovine perimysial collagen was examined using model systems. Pepsin and cathepsin solubilized collagen continuously over 24h (r = 0·95 andr = 0·88 for time course of pepsin and cathepsin solubilized collagen). Insoluble perimysium treated with pepsin over 24 h resulted in little damage to the insoluble collagenous residue remaining, as evidenced by one-dimensional SDS-polyacrylamide gel electrophoresis. Insoluble perimysium treated with cathepsin resulted in changes to the major peptide bands which were evident after 24 h treatment, visible as broadening and 'fuzziness' of bands, decreased staining intensity, loss of high molecular weight material and a significant reduction in quantity of all peptides when compared with untreated perimysium. The effects of proteolytic action on bovine perimysial collagen in vitro and in conditioned meat were investigated by means of two-dimensional polyacrylamide gel electrophoresis, which provided a more sensitive technique for elucidating changes than the one-dimensional method. The peptide maps obtained from conditioned insoluble perimysium and from insoluble perimysium treated with cathepsin for 24 h were altered relative to the unconditioned insoluble perimysium, with the loss of some peptides and generation of others. The in vitro case was extreme, but was comparable with samples of perimysium from conditioned muscles. The results provide direct biochemical evidence for the presence of proteolytic damage in the insoluble perimysial collagen matrix of meat after conditioning. PMID:22055668

  11. Acid Rain Affecting the Electrical Properties of Outdoor Composite Dielectric Materials

    NASA Astrophysics Data System (ADS)

    Wang, Xinsheng; Kumagai, Seiji; Yoshimura, Noboru

    1998-12-01

    Acid rain is precipitation with acidity, i.e., pH, below 5.6. There is an increasing interest in the degradation of the electrical properties of outdoor composite dielectric materials under severe contaminant conditions such as acid rain. In this study, the degradation effects of acid rain on the outdoor composite dielectrics are investigated by accelerated aging due to artificial acid rain. Based on the investigation of acid rain, the composition of artificial acid rain is chosen to agree with the actual composition of precipitation. The surface potential, breakdown voltage, tracking resistance, and surface discharge current of dielectric materials are studied. Furthermore, the degradation mechanisms of electrical properties of composite dielectrics are discussed by investigating the degradation of the chemical and physical microstructures of material surface using Fourier transform infrared (FTIR), the X-ray diffraction spectrum (XDS), and the metalloscope. Experimental results show that the outdoor polymeric dielectrics suffer severely and degrade due to acid rain so that their surface electrical properties deteriorate after aging. The erosion, by acid rain, of the energized dielectric materials is larger than that of outdoor materials used for other purposes.

  12. Insoluble distillers' dried grain (DDG) fraction in chemically leavened bread

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to evaluate the addition of thermo-mechanically treated corn Distillers’ Dried Grain (DDG) on batter and bread quality characteristics. DDG was processed by jet-cooking homogenized slurry of DDG and water followed by centrifugation and drum drying the insoluble fract...

  13. Battle of the starches: Insoluble versus soluble at the refinery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study using the USDA starch research method has been conducted to evaluate the effects of total, insoluble, and soluble starch on raw sugar filterability and viscosity in international carbonatation refineries. Raw sugar qualities, i.e., pol, color, % invert, ash, and dextran, were also studied in...

  14. Investigation of insoluble endogenous fractions of gastrointestinal tract by SRXRF

    NASA Astrophysics Data System (ADS)

    Trunova, V. A.; Zvereva, V. V.

    2005-05-01

    For the determination of the elemental composition of insoluble endogenous fractions from gastrointestinal tract by SRXRF (XRF experimental beam line, VEPP-3, INP SU RAS, Novosibirsk), an analytical method was developed for producing epithelial tissue in vivo. The metrological characteristics were determined using a number of international biological standards.

  15. Aqueous alkali metal hydroxide insoluble cellulose ether membrane

    NASA Technical Reports Server (NTRS)

    Hoyt, H. E.; Pfluger, H. L. (Inventor)

    1969-01-01

    A membrane that is insoluble in an aqueous alkali metal hydroxide medium is described. The membrane is a resin which is a water-soluble C2-C4 hydroxyalkyl cellulose ether polymer and an insolubilizing agent for controlled water sorption, a dialytic and electrodialytic membrane. It is particularly useful as a separator between electrodes or plates in an alkaline storage battery.

  16. Main chain acid-degradable polymers for the delivery of bioactive materials

    DOEpatents

    Frechet, Jean M. J.; Standley, Stephany M.; Jain, Rachna; Lee, Cameron C.

    2012-03-20

    Novel main chain acid degradable polymer backbones and drug delivery systems comprised of materials capable of delivering bioactive materials to cells for use as vaccines or other therapeutic agents are described. The polymers are synthesized using monomers that contain acid-degradable linkages cleavable under mild acidic conditions. The main chain of the resulting polymers readily degrade into many small molecules at low pH, but remain relatively stable and intact at physiological pH. The new materials have the common characteristic of being able to degrade by acid hydrolysis under conditions commonly found within the endosomal or lysosomal compartments of cells thereby releasing their payload within the cell. The materials can also be used for the delivery of therapeutics to the acidic regions of tumors and other sites of inflammation.

  17. Gas Cluster Ion Beam Etching under Acetic Acid Vapor for Etch-Resistant Material

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Akira; Hinoura, Ryo; Toyoda, Noriaki; Hara, Ken-ichi; Yamada, Isao

    2013-05-01

    Gas cluster ion beam (GCIB) etching of etch-resistant materials under acetic acid vapor was studied for development of new manufacturing process of future nonvolatile memory. Etching depths of various etch-resistant materials (Pt, Ru, Ta, CoFe) with acetic acid vapor during O2-GCIB irradiations were 1.8-10.7 times higher than those without acetic acid. Also, etching depths of Ru, Ta, CoFe by Ar-GCIB with acetic acid vapor were 2.2-16.1 times higher than those without acetic acid. Even after etching of Pt, smoothing of Pt was realized using O2-GCIB under acetic acid. From XPS and angular distribution of sputtered Pt, it was shown that PtOx layer was formed on Pt after O2-GCIB irradiation. PtOx reacted with acetic acid by GCIB bombardments; as a result, increase of etching depth was observed.

  18. Graphitization of Organic Material in a Progressively Metamorphosed Precambrian Iron Formation.

    PubMed

    French, B M

    1964-11-13

    Organic matter in the sedimentary Biwabik iron formation in northern Minnesota shows a progressive increase in crystallinity where the formation is metamorphosed by the intrusive Duluth gabbro complex. X-ray diffraction of acid-insoluble residues shows that there is a complete range in crystallinity, from amorphous material in the unmetamorphosed sediments to completely crystalline graphite adjacent to the gabbro. PMID:17777057

  19. Static corrosion of construction materials exposed to superphosphoric acid made from various sources of phosphate rock

    SciTech Connect

    Nguyen, D.T.; McDonald, C.L.; McGill, K.E.

    1994-10-01

    Corrosion tests were performed with various construction materials, such as carbon steel, cast iron, stainless steels, nickel and nickel-based alloys, copper and its alloys, aluminum alloy, zirconium alloy, and tantalum, exposed to wet-process superphosphoric acids (approximately 70% P{sub 2}O{sub 5}) from all the suppliers in the United States and to a technical-grade (55% P{sub 2}O{sub 5}) acid made by the electric furnace process. The study was conducted in response to reports from pipe-reactor users of excessive corrosion by superphosphoric acids and electric furnace acid. Test temperatures were ambient (approximately 21{degrees}C or 70{degrees}F), 66{degrees}C (150{degrees}F), and 93{degrees}C (200{degrees}F). Test results showed that temperature was a significant factor in acid corrosivity. Electric furnace acid was more corrosive than the superphosphoric acids. Carbon steel, cast iron, and aluminum alloy were not resistant to either the superphosphoric acids or the electric furnace acid. Nickel-chromium (Ni-Cr) and nickel-molybdenum (Ni-Mo) based alloys and tantalum exhibited adequate corrosion resistance in the superphosphoric acids and the electric furnace acid. Stainless steels performed well in all test acids at all test temperatures with some exceptions in the electric furnace acid at 93{degrees}C. Zirconium alloy, copper and its alloys, pure nickel, and Monel 400 provided adequate corrosion resistance to all test acids at ambient temperature only.

  20. Organic Analysis in the Miller Range 090657 CR2 Chondrite: Part 2 Amino Acid Analyses

    NASA Technical Reports Server (NTRS)

    Burton, A. S.; Cao, T.; Nakamura-Messenger, K.; Berger, E. L.; Messenger, S.; Clemett, S. J.; Aponte, J. C.; Elsila, J. E.

    2016-01-01

    Primitive carbonaceous chondrites contain a wide variety of organic material, ranging from soluble discrete molecules to insoluble, unstructured kerogen-like components, as well as structured nano-globules of macromolecular carbon. The relationship between the soluble organic molecules, macromolecular organic material, and host minerals are poorly understood. Due to the differences in extractability of soluble and insoluble organic materials, the analysis methods for each differ and are often performed independently. The combination of soluble and insoluble analyses, when performed concurrently, can provide a wider understanding of spatial distribution, and elemental, structural and isotopic composition of organic material in primitive meteorites. Using macroscale extraction and analysis techniques in combination with in situ microscale observation, we have been studying both insoluble and soluble organic material in the primitive CR2 chondrite Miller Range (MIL) 090657. In accompanying abstracts (Cao et al. and Messenger et al.) we discuss insoluble organic material in the samples. By performing the consortium studies, we aim to improve our understanding of the relationship between the meteorite minerals and the soluble and insoluble organic phases and to delineate which species formed within the meteorite and those that formed in nebular or presolar environments. In this abstract, we present the results of amino acid analyses of MIL 090657 by ultra performance liquid chromatography with fluorescence detection and quadrupole-time of flight mass spectrometry. Amino acids are of interest because they are essential to life on Earth, and because they are present in sufficient structural, enantiomeric and isotopic diversity to allow insights into early solar system chemical processes. Furthermore, these are among the most isotopically anomalous species, yet at least some fraction are thought to have formed by aqueously-mediated processes during parent body alteration.

  1. An In Situ Method for Sizing Insoluble Residues in Precipitation

    NASA Astrophysics Data System (ADS)

    Axson, J. L.; Creamean, J.; Bondy, A. L.; Warner, K. Y.; Ault, A. P.

    2014-12-01

    Aerosols acting as cloud condensation nuclei (CCN) and ice nuclei (IN) play an important role in the climate effects of clouds. Wet deposition of these particles via rainout, washout, or cloud seeding is an important removal mechanism for aerosols in the atmosphere. Many of these particles, especially those that serve as IN, are insoluble and remain suspended after uptake within precipitating droplets/crystals as insoluble residues. While studies have measured the dissolved ions or mass of species within collected precipitation, no studies to date have quantified the number and size of insoluble residues. Herein, we demonstrate for the first time an in situ method for determining the number concentration, number size distribution, and surface area distribution of insoluble residues < 1 μm in diameter in samples of melted snow and rain. This work evaluates the use of nanoparticle tracking analysis (NTA), a new and novel technique for determining particle size distributions in a liquid medium, to determine in situ size distributions of insoluble residue particles in precipitation and evaluate this technique versus other analytical methods, including dynamic light scattering (DLS) and transmission electron microscopy (TEM). Number size distribution modes ranged from 80-150 nm and were strongly sample dependent. Surface area distribution modes ranged from 150-400 nm. Differences were observed between concentrations and size distributions for snow collected at different locations and elevations and between rain and melted snow. These differences can indicate changes in the insoluble residues that vary with ambient aerosol concentration, cloud microphysics, and meteorological dynamics. This method has great potential for improving our understanding of the properties of the particles nucleating droplets and crystals, the surface area available for reactions to occur, and the number of particles removed by scavenging. Additionally, the snow samples were further evaluated

  2. A review on synthesis and characterization of solid acid materials for fuel cell applications

    NASA Astrophysics Data System (ADS)

    Mohammad, Norsyahida; Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Loh, Kee Shyuan

    2016-08-01

    Solid acids emerged as an electrolyte material for application in fuel cells due to their high protonic conductivity and stability at high temperatures between 100 °C and 250 °C. This paper gives an overview of the different solid acid materials and their properties, such as high protonic conductivity and thermal stability, in relation to phase transitions and mechanisms of proton transport. Various solid acid synthesis methods including aqueous and dry mixing, electrospinning, sol-gel, impregnation and thin-film casting will be discussed, and the impact of synthesis methods on the properties of solid acids will be highlighted. The properties of solid acids synthesized as either single crystals and or polycrystalline powders were identified via X-ray diffraction, nuclear magnetic resonance, thermal analyses, optical microscopy and infrared spectroscopy. A selection of electrolyte-electrode assembly methods and the performance of solid acid fuel cell prototypes are also reviewed.

  3. Repeated exposure of acidic beverages on esthetic restorative materials: An in-vitro surface microhardness study

    PubMed Central

    Sunny, Steffy M.; Rai, Kavita; Hegde, Amitha M.

    2016-01-01

    Background A manifold increase in the consumption of aerated beverages has witnessed a twin increase in tooth wear and raised demand for esthetic restorative materials. This study aimed to evaluate the surface microhardness changes of esthetic restorative materials following treatment with aerated beverages in an in-vitro situation. Material and Methods The initial surface microhardness of the restorative materials GC Fuji II LC, GC Fuji IX, Nano Glass ionomer, Resin and Nano composite was recorded. These materials were studied under 3 groups that included those exposed to the acidic beverages daily, weekly once in a month and those that had no exposures at all. The final surface microhardness of the materials was recorded following experimentation and was subjected to statistical comparisons. Results The restorative materials were compared for their surface microhardness changes following respective treatments using the T-test and One-way ANOVA analysis. Inter-comparisons between the groups showed statistical significance (p<.05), when treated with both the beverages. The five restorative materials revealed surface microhardness loss; the maximum reduction noticed with the Nano glass ionomer cement tested (p<.0005). Conclusions The surface microhardness of restorative materials markedly reduced upon repeated exposures with acidic beverages; the product with phosphoric acid producing the maximum surface microhardness loss. Key words:Restorative materials, acidic beverages, surface microhardness, resin composites, glass ionomers. PMID:27398183

  4. Soluble and insoluble carbon content in fog: a 16 year long study in the Po Valley (Italy)

    NASA Astrophysics Data System (ADS)

    Fuzzi, S.; Facchini, C.; Giulianelli, L.; Gilardoni, S.

    2015-12-01

    Fog samples have been collected throughout the fall-winter season during each dense fog episode since 1989 at the field station of San Pietro Capofiume (Bologna, Italy) located in a rural area in the south-eastern part of the Po Valley. Since the fall-winter season 1997/98 both soluble and insoluble carbon content was also measured and now a sixteen years long dataset is available. Carbonaceous matter accounts for a significant fraction of the insoluble material suspended in fog water. The sum of EC and water insoluble organic mass accounts on average for 46%-56% of the mass of total suspended material. Insoluble carbonaceous material is composed mainly by organic matter, EC accounting on average only for 17% of the total insoluble carbon. A good correlation observed between EC and OC through the different years, suggests that anthropogenic combustion processes, which represent the main source of EC, are also the most important source of OC in fog droplets. Recent results also show that a potential important contribution to WSOC in for water is derived by aqueous secondary organic aerosol from biomass burning emissions. The water soluble organic carbon (WSOC) represents on average 25% of the total solute mass and its contribution to the total organic carbon (TOC) ranges from 52 to 95% with an average of 86%. The high amount of carbonaceous compounds in the Po Valley fog detected and the simultaneous decrease of the main inorganic species concentration (Giulianelli et al., 2014) in the last two decades highlight the potential influence of organics on the decrease of fog frequency. Giulianelli L., Gilardoni S., Tarozzi L., Rinaldi M., Decesari S, Carbone C., Facchini M.C. and Fuzzi S., Atmos. Environ. 98, 394-401.

  5. 21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a... cystic fibrosis nucleic acid assays is a device intended to help monitor reliability of a test system by... testing. This type of device includes recombinant, synthetic, and cell line-based DNA controls....

  6. 21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a... cystic fibrosis nucleic acid assays is a device intended to help monitor reliability of a test system by... testing. This type of device includes recombinant, synthetic, and cell line-based DNA controls....

  7. 21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a... cystic fibrosis nucleic acid assays is a device intended to help monitor reliability of a test system by... testing. This type of device includes recombinant, synthetic, and cell line-based DNA controls....

  8. 21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a... cystic fibrosis nucleic acid assays is a device intended to help monitor reliability of a test system by... testing. This type of device includes recombinant, synthetic, and cell line-based DNA controls....

  9. 21 CFR 866.5910 - Quality control material for cystic fibrosis nucleic acid assays.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Test Systems § 866.5910 Quality control material for cystic fibrosis nucleic acid assays. (a... cystic fibrosis nucleic acid assays is a device intended to help monitor reliability of a test system by... testing. This type of device includes recombinant, synthetic, and cell line-based DNA controls....

  10. Starch-lipid complexes: Interesting material and applications from amylose-fatty acid salt inclusion complexes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aqueous slurries of high amylose starch can be steam jet cooked and blended with aqueous solutions of fatty acid salts to generate materials that contain inclusion complexes between amylose and the fatty acid salt. These complexes are simply prepared on large scale using commercially available steam...

  11. Characterization of insoluble nanoparticles in Antarctic ice cores

    NASA Astrophysics Data System (ADS)

    Ellis, A.; Edwards, R.; Van Riessen, A.; Saunders, M.; Smith, A. M.; Curran, M. A.; Goodwin, I. D.; Feiteng, W.

    2013-12-01

    Insoluble nanoparticles in the form of aerosols have significant effects on climate and biogeochemical cycles. Records of these aerosols are essential for understanding paleoclimate forcing and future climate change. These particles and their precursors are emitted to the atmosphere from a variety of primary and secondary sources including biomass burning as well as biogenic, anthropogenic, volcanic, extraterrestrial, and terrestrial mineral emissions. While a large body of research exists with respect to mineral dust particles (on the micrometer scale) derived from ice and sediment cores, very little is known with regards to the history of insoluble particles on the nano scale. Ice core records are the only reliable way to study the past history of these particles. Here, we will present new data regarding the physical and chemical properties of nanoparticles found in ice cores from East Antarctica.

  12. Insoluble polyelectrolyte and ion-exchange hollow fiber impregnated therewith

    NASA Technical Reports Server (NTRS)

    Rembaum, A. (Inventor)

    1977-01-01

    The number of quaternary sites and ion exchange capacity of a polyquaternary, cross linked, insoluble copolymer of a vinyl pyridine and a dihalo organic compound is increased by about 15-35% by reaction of the polymer with an amine followed by quaternization, if required. The polymer forms spontaneously in the presence of a substrate such as within the pores of a hollow fiber. The improved resin impregnated fiber may be utilized to remove ions from waste or process steams.

  13. Binding and solubility of oleic acid to laboratory materials: A possible artifact

    SciTech Connect

    Mailman, D.; Rose, C. )

    1990-01-01

    The possibility that significant amounts of fatty acids were dissolved in or bound to the surfaces of common laboratory materials was examined. The uptake or adsorption of radioisotopically labeled oleic acid and cholic acid by plastic tubing of Tygon{trademark}, Teflon{trademark}, and polyethylene, and Pyrex{trademark}, and borosilicate glass, and steel was measured. {sup 3}H-oleic acid and {sup 14}C-cholic acid were used in the presence of different concentration of unlabeled oleic acid, cholic acid, and/or bovine serum albumin. Concentrations, composition, pH, and perfusion rates were varied. Relatively large amounts of oleic acid were lost by dissolving in plastic and adsorption to glass or metal. The degree of losses decreased in the presence of compounds in the perfusion solution which could bind or dissolve oleic acid. In contrast, cholic acid was not lost to plastic, glass or metal. The magnitude of and influence of perfusion rate, composition, pH, and sequence of perfusion solutions on oleic acid losses were sufficiently large that the results of certain studies, such as those of unstirred water layers or albumin-stimulated fatty acid uptake by hepatocytes may need to be reexamined.

  14. Synthesis, characterization and catalytic activity of acid-base bifunctional materials through protection of amino groups

    SciTech Connect

    Shao, Yanqiu; Liu, Heng; Yu, Xiaofang; Guan, Jingqi; Kan, Qiubin

    2012-03-15

    Graphical abstract: Acid-base bifunctional mesoporous material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized under low acidic medium through protection of amino groups. Highlights: Black-Right-Pointing-Pointer The acid-base bifunctional material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized through protection of amino groups. Black-Right-Pointing-Pointer The obtained bifunctional material was tested for aldol condensation. Black-Right-Pointing-Pointer The SO{sub 3}H-SBA-15-NH{sub 2} catalyst containing amine and sulfonic acid groups exhibited excellent acid-basic properties. -- Abstract: Acid-base bifunctional mesoporous material SO{sub 3}H-SBA-15-NH{sub 2} was successfully synthesized under low acidic medium through protection of amino groups. X-ray diffraction (XRD), N{sub 2} adsorption-desorption, transmission electron micrographs (TEM), back titration, {sup 13}C magic-angle spinning (MAS) NMR and {sup 29}Si magic-angle spinning (MAS) NMR were employed to characterize the synthesized materials. The obtained bifunctional material was tested for aldol condensation reaction between acetone and 4-nitrobenzaldehyde. Compared with monofunctional catalysts of SO{sub 3}H-SBA-15 and SBA-15-NH{sub 2}, the bifunctional sample of SO{sub 3}H-SBA-15-NH{sub 2} containing amine and sulfonic acid groups exhibited excellent acid-basic properties, which make it possess high activity for the aldol condensation.

  15. Transmission of Soluble and Insoluble α-Synuclein to Mice.

    PubMed

    Jones, Daryl Rhys; Delenclos, Marion; Baine, AnnMarie T; DeTure, Michael; Murray, Melissa E; Dickson, Dennis W; McLean, Pamela J

    2015-12-01

    The neurodegenerative synucleinopathies, which include Parkinson disease, multiple-system atrophy, and Lewy body disease, are characterized by the presence of abundant neuronal inclusions called Lewy bodies and Lewy neurites. These disorders remain incurable, and a greater understanding of the pathologic processes is needed for effective treatment strategies to be developed. Recent data suggest that pathogenic misfolding of the presynaptic protein, α-synuclein (α-syn), and subsequent aggregation and accumulation are fundamental to the disease process. It is hypothesized that the misfolded isoform is able to induce misfolding of normal endogenous α-syn, much like what occurs in the prion diseases. Recent work highlighting the seeding effect of pathogenic α-syn has largely focused on the detergent-insoluble species of the protein. In this study, we performed intracerebral inoculations of the sarkosyl-insoluble or sarkosyl-soluble fractions of human Lewy body disease brain homogenate and show that both fractions induce CNS pathology in mice at 4 months after injection. Disease-associated deposits accumulated both near and distal to the site of the injection, suggesting a cell-to-cell spread via recruitment of α-syn. These results provide further insight into the prion-like mechanisms of α-syn and suggest that disease-associated α-syn is not homogeneous within a single patient but might exist in both soluble and insoluble isoforms. PMID:26574670

  16. An Insoluble Titanium-Lead Anode for Sulfate Electrolytes

    SciTech Connect

    Ferdman, Alla

    2005-05-11

    The project is devoted to the development of novel insoluble anodes for copper electrowinning and electrolytic manganese dioxide (EMD) production. The anodes are made of titanium-lead composite material produced by techniques of powder metallurgy, compaction of titanium powder, sintering and subsequent lead infiltration. The titanium-lead anode combines beneficial electrochemical behavior of a lead anode with high mechanical properties and corrosion resistance of a titanium anode. In the titanium-lead anode, the titanium stabilizes the lead, preventing it from spalling, and the lead sheathes the titanium, protecting it from passivation. Interconnections between manufacturing process, structure, composition and properties of the titanium-lead composite material were investigated. The material containing 20-30 vol.% of lead had optimal combination of mechanical and electrochemical properties. Optimal process parameters to manufacture the anodes were identified. Prototypes having optimized composition and structure were produced for testing in operating conditions of copper electrowinning and EMD production. Bench-scale, mini-pilot scale and pilot scale tests were performed. The test anodes were of both a plate design and a flow-through cylindrical design. The cylindrical anodes were composed of cylinders containing titanium inner rods and fitting over titanium-lead bushings. The cylindrical design allows the electrolyte to flow through the anode, which enhances diffusion of the electrolyte reactants. The cylindrical anodes demonstrate higher mass transport capabilities and increased electrical efficiency compared to the plate anodes. Copper electrowinning represents the primary target market for the titanium-lead anode. A full-size cylindrical anode performance in copper electrowinning conditions was monitored over a year. The test anode to cathode voltage was stable in the 1.8 to 2.0 volt range. Copper cathode morphology was very smooth and uniform. There was no

  17. Boronic acid-modified magnetic materials for antibody purification.

    PubMed

    Dhadge, Vijaykumar L; Hussain, Abid; Azevedo, Ana M; Aires-Barros, Raquel; Roque, Ana C A

    2014-02-01

    Aminophenyl boronic acids can form reversible covalent ester interactions with cis-diol-containing molecules, serving as a selective tool for binding glycoproteins as antibody molecules that possess oligosaccharides in both the Fv and Fc regions. In this study, amino phenyl boronic acid (APBA) magnetic particles (MPs) were applied for the magnetic separation of antibody molecules. Iron oxide MPs were firstly coated with dextran to avoid non-specific binding and then with 3-glycidyloxypropyl trimethoxysilane to allow further covalent coupling of APBA (APBA_MP). When contacted with pure protein solutions of human IgG (hIgG) and bovine serum albumin (BSA), APBA_MP bound 170 ± 10 mg hIgG g(-1) MP and eluted 160 ± 5 mg hIgG g(-1) MP, while binding only 15 ± 5 mg BSA g(-1) MP. The affinity constant for the interaction between hIgG and APBA_MP was estimated as 4.9 × 10(5) M(-1) (Ka) with a theoretical maximum capacity of 492 mg hIgG adsorbed g(-1) MP (Qmax), whereas control particles bound a negligible amount of hIgG and presented an estimated theoretical maximum capacity of 3.1 mg hIgG adsorbed g(-1) MP (Qmax). APBA_MPs were also tested for antibody purification directly from CHO cell supernatants. The particles were able to bind 98% of IgG loaded and to recover 95% of pure IgG (purity greater than 98%) at extremely mild conditions. PMID:24258155

  18. 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.

  19. Studies on the solubilization of the water-insoluble fraction from human lens and cataract.

    PubMed

    Ortwerth, B J; Olesen, P R

    1992-12-01

    Studies were carried out comparing the ability of urea extraction and sonication to solubilize the water-insoluble (WI) protein fraction from human lens tissue. Sonication and urea extraction were able to solubilize greater than 80% of the insoluble protein whether whole lenses or lens nuclei were used. This was true for normal lens and +1 cataracts; however, only 60% solubilization was obtained with the WI fraction from more advanced cataracts. Equal aliquots of a WI fraction from both pooled normal and pooled cataract lens nuclei were solubilized with and without reducing agents. The addition of dithiothreitol (DTT) had no significant effect on solubilization of the normal lens WI fraction. DTT did increase the protein solubilized from the cataract WI fraction by 30% with urea extraction; however, no increase was seen with sonication. When sodium borohydride was used as the reducing agent, essentially the same results were obtained. The solubilized protein populations were identical by SDS-PAGE and amino acid analysis. The addition of reducing agents had no effect on the amino acid content of the solubilized proteins with the single exception of lysine. This amino acid was markedly decreased in the proteins extracted in the presence of 40 mM sodium borohydride, but not with DTT. These data suggest that the borohydride not only increased the amount of protein solubilized, but likely also stabilized glycated lysine residues during the acid hydrolysis. Therefore, sonication readily provides a soluble preparation of the WI proteins from normal and cataract lens nuclei without the need for denaturing agents, however, disulfide-linked and lysine modified crystallins were best solubilized with urea. PMID:1486936

  20. Laboratory study of acid stimulation of drilling-mud-damaged geothermal-reservoir materials. Final report

    SciTech Connect

    Not Available

    1983-05-01

    Presented here are the results of laboratory testing performed to provide site specific information in support of geothermal reservoir acidizing programs. The testing program included laboratory tests performed to determine the effectiveness of acid treatments in restoring permeability of geologic materials infiltrated with hydrothermally altered sepiolite drilling mud. Additionally, autoclave tests were performed to determine the degree of hydrothermal alteration and effects of acid digestion on drilling muds and drill cuttings from two KGRA's. Four laboratory scale permeability/acidizing tests were conducted on specimens prepared from drill cuttings taken from two geothermal formations. Two tests were performed on material from the East Mesa KGRA Well No. 78-30, from a depth of approximately 5500 feet, and two tests were performed on material from the Roosevelt KGRA Well No. 52-21, from depths of approximately 7000 to 7500 feet. Tests were performed at simulated in situ geothermal conditions of temperature and pressure.

  1. Development and Evaluation of a Calibrator Material for Nucleic Acid-Based Assays for Diagnosing Aspergillosis

    PubMed Central

    Abdul-Ali, Deborah; Loeffler, Juergen; White, P. Lewis; Wickes, Brian; Herrera, Monica L.; Alexander, Barbara D.; Baden, Lindsey R.; Clancy, Cornelius; Denning, David; Nguyen, M. Hong; Sugrue, Michele; Wheat, L. Joseph; Wingard, John R.; Donnelly, J. Peter; Barnes, Rosemary; Patterson, Thomas F.; Caliendo, Angela M.

    2013-01-01

    Twelve laboratories evaluated candidate material for an Aspergillus DNA calibrator. The DNA material was quantified using limiting-dilution analysis; the mean concentration was determined to be 1.73 × 1010 units/ml. The calibrator can be used to standardize aspergillosis diagnostic assays which detect and/or quantify nucleic acid. PMID:23616459

  2. The formation of an ordered microporous aluminum-based material mediated by phthalic acid.

    PubMed

    Zhang, Wei; Cai, Jian-Hua; Huang, Pei-Pei; Hu, Lin-Lin; Cao, An-Min; Wan, Li-Jun

    2016-06-28

    By using phthalic acid as a soft template, we showed that it was possible to prepare a microporous aluminum-based material when the precipitation of Al(3+) was properly controlled. We also identified that this microporous aluminum-based material could be promising for the removal of fluoride ions in water treatment. PMID:27263661

  3. The polymer-like organic material in the Orgueil meteorite

    NASA Technical Reports Server (NTRS)

    Bandurski, E. L.; Nagy, B.

    1976-01-01

    Results are reported for analysis of polymeric organic material contained in powder from the Orgueil chondrite, using a stepwise high-vacuum pyrolysis-gas chromatography-mass spectrometry technique. Pyrolysis products obtained include a series of alkanes and alkenes to C8, an extensive series of alkylbenzene isomers, thiophene, alkylthiophenes, benzothiophene, acetonitrile, acrylonitrile, benzonitrile, acetone, and phenol. Most of these products are shown to be similar both qualitatively and quantitatively to those previously obtained from solvent-extracted Allende powder, indicating a basically aromatic and heteroaromatic polymer matrix with short aliphatic bridges or side chains. The production of acrylonitrile, acetonitrile, and benzonitrile (common breakdown products of amino acids) from the insoluble organic material is taken to suggest that amino acids exist in an insoluble form, perhaps as peptides, in the meteorite's polymeric component. Similarities between the structure of the Orgueil polymeric material and terrestrial kerogen are discussed which raise the possibility that both might have been produced in part by similar reactions.

  4. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydroxyethyl cellulose film, water-insoluble. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances... cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used...

  5. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydroxyethyl cellulose film, water-insoluble. 177... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances... cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used...

  6. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydroxyethyl cellulose film, water-insoluble. 177... cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used for... cellulose film consists of a base sheet manufactured by the ethoxylation of cellulose under...

  7. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydroxyethyl cellulose film, water-insoluble. 177... cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used for... cellulose film consists of a base sheet manufactured by the ethoxylation of cellulose under...

  8. 21 CFR 177.1400 - Hydroxyethyl cellulose film, water-insoluble.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydroxyethyl cellulose film, water-insoluble. 177... Repeated Use Food Contact Surfaces § 177.1400 Hydroxyethyl cellulose film, water-insoluble. Water-insoluble hydroxyethyl cellulose film may be safely used for packaging food in accordance with the following...

  9. Testing the role of silicic acid and bioorganic materials in the formation of rock coatings

    NASA Astrophysics Data System (ADS)

    Kolb, Vera M.; Philip, Ajish I.; Perry, Randall S.

    2004-11-01

    Silica, amino acids, and DNA were recently discovered in desert varnish. In this work we experimentally test the proposed role of silicic acid and bio-chemicals in the formation of desert varnish and other rock coatings. We have developed a protocol in which the rocks were treated with a mixture of silicic acid, sugars, amino acids, metals and clays, under the influence of heat and UV light. This protocol reflects the proposed mechanism of the polymerization of silicic acid with the biooganic materials, and the laboratory model for the natural conditions under which the desert varnish is formed. Our experiments produced coatings with a hardness and morphology that resemble the natural ones. These results provide a support for the role of silicic acid in the formation of rock coatings. Since the hard silica-based coatings preserve organic compounds in them, they may serve as a biosignature for life, here or possibly on Mars.

  10. Testing the Role of Silicic Acid and Bioorganic Materials in the Formation of Rock Coatings

    SciTech Connect

    Kolb, Vera; Philip, Ajish I.; Perry, Randall S.

    2004-12-01

    Silica, amino acids, and DNA were recently discovered in desert varnish. In this work we experimentally test the proposed role of silicic acid and bio-chemicals in the formation of desert varnish and other rock coatings. We have developed a protocol in which hte rocks were treated with a mixture of silicic acid, sugars, amino acids, metals and clays, under the influence of heat and UV light. This protocol reflects the proposed mechanism of hte polymerization of silicic acid with the bioorganic materials, and the laboratory model for the natural conditions under which the desert varnish is formed. Our experiments produced coatings with a hardness and morphology that resemble the nature ones. These results provide a support for the role of silicic acid in the formation of rock coatings. Since the hard silica-based coatings preserve organic compounds in them, they may serve as a biosignature for life, here or possibly Mars.

  11. Tracking of Drug Release and Material Fate for Naturally Derived Omega-3 Fatty Acid Biomaterials.

    PubMed

    Faucher, Keith M; Artzi, Natalie; Beck, Moshe; Beckerman, Rita; Moodie, Geoff; Albergo, Theresa; Conroy, Suzanne; Dale, Alicia; Corbeil, Scott; Martakos, Paul; Edelman, Elazer R

    2016-03-01

    In vitro and in vivo studies were conducted on omega-3 fatty acid-derived biomaterials to determine their utility as an implantable material for adhesion prevention following soft tissue hernia repair and as a means to allow for the local delivery of antimicrobial or antibiofilm agents. Naturally derived biomaterials offer several advantages over synthetic materials in the field of medical device development. These advantages include enhanced biocompatibility, elimination of risks posed by the presence of toxic catalysts and chemical crosslinking agents, and derivation from renewable resources. Omega-3 fatty acids are readily available from fish and plant sources and can be used to create implantable biomaterials either as a stand-alone device or as a device coating that can be utilized in local drug delivery applications. In-depth characterization of material erosion degradation over time using non-destructive imaging and chemical characterization techniques provided mechanistic insight into material structure: function relationship. This in turn guided rational tailoring of the material based on varying fatty acid composition to control material residence time and hence drug release. These studies demonstrate the utility of omega-3 fatty acid derived biomaterials as an absorbable material for soft tissue hernia repair and drug delivery applications. PMID:26502170

  12. Preparation, characterization and catalytic properties of MCM-48 supported tungstophosphoric acid mesoporous materials for green synthesis of benzoic acid

    SciTech Connect

    Wu, Hai-Yan; Zhang, Xiao-Li; Chen, Xi; Chen, Ya; Zheng, Xiu-Cheng

    2014-03-15

    MCM-48 and tungstophosphoric acid (HPW) were prepared and applied for the synthesis of HPW/MCM-48 mesoporous materials. The characterization results showed that HPW/MCM-48 obtained retained the typical mesopore structure of MCM-48, and the textural parameters decreased with the increase loading of HPW. The catalytic oxidation results of benzyl alcohol and benzaldehyde with 30% H{sub 2}O{sub 2} indicated that HPW/MCM-48 was an efficient catalyst for the green synthesis of benzoic acid. Furthermore, 35 wt% HPW/MCM-48 sample showed the highest activity under the reaction conditions. Highlights: • 5–45 wt% HPW/MCM-48 mesoporous catalysts were prepared and characterized. • Their catalytic activities for the green synthesis of benzoic acid were investigated. • HPW/MCM-48 was approved to be an efficient catalyst. • 5 wt% HPW/MCM-48 exhibited the highest catalytic activity.

  13. Development of botanical and fish oil standard reference materials for fatty acids.

    PubMed

    Schantz, Michele M; Sander, Lane C; Sharpless, Katherine E; Wise, Stephen A; Yen, James H; NguyenPho, Agnes; Betz, Joseph M

    2013-05-01

    As part of a collaboration with the National Institutes of Health's Office of Dietary Supplements and the Food and Drug Administration's Center for Drug Evaluation and Research, the National Institute of Standards and Technology has developed Standard Reference Material (SRM) 3274 Botanical Oils Containing Omega-3 and Omega-6 Fatty Acids and SRM 3275 Omega-3 and Omega-6 Fatty Acids in Fish Oil. SRM 3274 consists of one ampoule of each of four seed oils (3274-1 Borage (Borago officinalis), 3274-2 Evening Primrose (Oenothera biennis), 3274-3 Flax (Linium usitatissimum), and 3274-4 Perilla (Perilla frutescens)), and SRM 3275 consists of two ampoules of each of three fish oils (3275-1 a concentrate high in docosahexaenoic acid, 3275-2 an anchovy oil high in docosahexaenoic acid and eicosapentaenoic acid, and 3275-3 a concentrate containing 60% long-chain omega-3 fatty acids). Each oil has certified and reference mass fraction values for up to 20 fatty acids. The fatty acid mass fraction values are based on results from analyses using gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC/MS). These SRMs will complement other reference materials currently available with mass fractions for similar analytes and are part of a series of SRMs being developed for dietary supplements. PMID:23371533

  14. Surface acidity effects of Al-SBA-15 mesoporous materials on adsorptive desulfurization.

    PubMed

    Meng, Xiuhong; Wang, Yuan; Duan, Linhai; Qin, Yucai; Yu, Wenguang; Wang, Qiang; Dong, Shiwei; Ruan, Yanjun; Wang, Haiyan; Song, Lijuan

    2014-09-01

    SBA-15 and Aluminum-substituted SBA-15 with Si/Al molar ratio 10 (Al-SBA-15(10)) mesoporous materials were directly synthesized by a hydrolysis approach and characterized by a powder X-ray diffraction (XRD), N2 physisorption analysis and Fourier transform infrared (FTIR) etc. The relative number of hydroxyl groups was investigated by in situ FTIR systematically. The acid type and acid strength of the adsorbents were monitord by FTIR at 423 K and 673 K, respectively, utilizing pyridine as a probe. Desulfurization performances of the adsorbents were investigated via static adsorption experiment. Gas chromatography-sulfur chemiluminescence detector (GC-SCD) was employed to detect the sulfur compounds in model fuels before and after treated by the adsorbents. The calcined Al-SBA-15(10) material shows well-ordered hexagonal mesostructure and strong Lewis acid sites (L acid) and weak Brönsted acid sites (B acid). The number of hydroxy on the surface of the Al-SBA-15(10) is more than that of SBA-15, which is beneficial to further modifications such as spontaneous monolayer dispersion. Desulfurization performance of the adsorbents is affected by surface acidity of adsorbents and the constituent of model fuels (olefins, arene, etc.). The thiophene and olefins adsorbed on the B acid site of the adsorbent may occur subsequently alkylation reactions, which may block the pores of the adsorbents and thus cause the reduction of desulfurization capacity. PMID:25924387

  15. New pyrolytic and spectroscopic data on Orgueil and Murchison insoluble organic matter: A different origin than soluble?

    NASA Astrophysics Data System (ADS)

    Remusat, Laurent; Derenne, Sylvie; Robert, François; Knicker, Heike

    2005-08-01

    Pyrolysis with and without tetramethylammonium hydroxide (TMAH), vacuum pyrolysis, and solid state 15N nuclear magnetic resonance (NMR) were used to examine the macromolecular insoluble organic matter (IOM) from the Orgueil and Murchison meteorites. Conventional pyrolysis reveals a set of poorly functionalized aromatic compounds, ranging from one to four rings and with random methyl substitutions. These compounds are in agreement with spectroscopic and pyrolytic results previously reported. For the first time, TMAH thermochemolysis was used to study extraterrestrial material. The detection of aromatics bearing methyl esters and methoxy groups reveals the occurrence of ester and ether bridges between aromatic units in the macromolecular network. No nitrogen-containing compounds were detected with TMAH thermochemolysis, although they are a common feature in terrestrial samples. Along with vacuum pyrolysis results, thermochemolysis shows that nitrogen is probably sequestered in condensed structures like heterocyclic aromatic rings, unlike oxygen, which is mainly located within linkages between aromatic units. This is confirmed by solid state 15N NMR performed on IOM from Orgueil, showing that nitrogen is present in pyrrole, indole, and carbazole moieties. These data show that amino acids are neither derived from the hydrolysis of IOM nor from a common precursor. In order to reconcile the literature isotopic data and the present molecular results, it is proposed that aldehydes and ketones (1) originated during irradiation of ice in space and (2) were then mobilized during the planetesimal hydrothermalism, yielding the formation of amino acids. If correct, prebiotic molecules are the products of the subsurface chemistry of planetesimals and are thus undetectable through astronomical probes.

  16. Insoluble calcium content and rheological properties of Colby cheese during ripening.

    PubMed

    Lee, M-R; Johnson, M E; Govindasamy-Lucey, S; Jaeggi, J J; Lucey, J A

    2010-05-01

    Colby cheese was made using different manufacturing conditions (i.e., varying the lactose content of milk and pH values at critical steps in the cheesemaking process) to alter the extent of acid development and the insoluble and total Ca contents of cheese. Milk was concentrated by reverse osmosis (RO) to increase the lactose content. Extent of acid development was modified by using high (HPM) and low (LPM) pH values at coagulant addition, whey drainage, and curd milling. Total Ca content was determined by atomic absorption spectroscopy, and the insoluble (INSOL) Ca content of cheese was measured by the cheese juice method. The rheological and melting properties of cheese were measured by small amplitude oscillatory rheometry and UW-Melt Profiler, respectively. There was very little change in pH during ripening even in cheese made from milk with high lactose content. The initial (d 1) cheese pH was in the range of 4.9 to 5.1. The INSOL Ca content of cheese decreased during the first 4 wk of ripening. Cheeses made with the LPM had lower INSOL Ca content during ripening compared with cheese made with HPM. There was an increase in melt and maximum loss tangent values during ripening except for LPM cheeses made with RO-concentrated milk, as this cheese had pH <4.9 and exhibited limited melt. Curd washing reduced the levels of lactic acid produced during ripening and resulted in significantly higher INSOL Ca content. The use of curd washing for cheeses made from high lactose milk prevented a large pH decrease during ripening; high rennet and draining pH values also retained more buffering constituents (i.e., INSOL Ca phosphate), which helped prevent a large pH decrease. PMID:20412897

  17. Development of Stable Solidification Method for Insoluble Ferrocyanides-13170

    SciTech Connect

    Ikarashi, Yuki; Masud, Rana Syed; Mimura, Hitoshi; Ishizaki, Eiji; Matsukura, Minoru

    2013-07-01

    The development of stable solidification method of insoluble ferrocyanides sludge is an important subject for the safety decontamination in Fukushima NPP-1. By using the excellent immobilizing properties of zeolites such as gas trapping ability and self-sintering properties, the stable solidification of insoluble ferrocyanides was accomplished. The immobilization ratio of Cs for K{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O saturated with Cs{sup +} ions (Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O) was estimated to be less than 0.1% above 1,000 deg. C; the adsorbed Cs{sup +} ions are completely volatilized. In contrast, the novel stable solid form was produced by the press-sintering of the mixture of Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O and zeolites at higher temperature of 1,000 deg. C and 1,100 deg. C; Cs volatilization and cyanide release were completely depressed. The immobilization ratio of Cs, under the mixing conditions of Cs{sub 2}[CoFe(CN){sub 6}].nH{sub 2}O:CP= 1:1 and calcining temperature: 1,000 deg. C, was estimated to be nearly 100%. As for the kinds of zeolites, natural mordenite (NM), clinoptilolite (CP) and Chabazite tended to have higher immobilization ratio compared to zeolite A. This may be due to the difference in the phase transformation between natural zeolites and synthetic zeolite A. In the case of the composites (K{sub 2-X}Ni{sub X/2}[NiFe(CN){sub 6}].nH{sub 2}O loaded natural mordenite), relatively high immobilization ratio of Cs was also obtained. This method using zeolite matrices can be applied to the stable solidification of the solid wastes of insoluble ferrocyanides sludge. (authors)

  18. Determination of effect factor for effective parameter on saccharification of lignocellulosic material by concentrated acid

    NASA Astrophysics Data System (ADS)

    Aghili, Sina; Nodeh, Ali Arasteh

    2015-12-01

    Tamarisk usage as a new group of lignocelluloses material to produce fermentable sugars in bio ethanol process was studied. The overall aim of this work was to establish the optimum condition for acid hydrolysis of this new material and a mathematical model predicting glucose release as a function of operation variable. Sulfuric acid concentration in the range of 20 to 60%(w/w), process temperature between 60 to 95oC, hydrolysis time from 120 to 240 min and solid content 5,10,15%(w/w) were used as hydrolysis conditions. HPLC was used to analysis of the product. This analysis indicated that glucose was the main fermentable sugar and was increase with time, temperature and solid content and acid concentration was a parabola influence in glucose production. The process was modeled by a quadratic equation. Curve study and model were found that 42% acid concentration, 15 % solid content and 90oC were optimum condition.

  19. Determination of amino acids in fodders and raw materials using capillary zone electrophoresis.

    PubMed

    Komarova, N V; Kamentsev, J S; Solomonova, A P; Anufrieva, R M

    2004-02-01

    Two schemes were offered for analysis of amino acid contents in fodders and raw materials for mixed fodders by capillary zone electrophoresis (CZE). The first variant provides express analysis of four technologically important amino acids (lysine, methionine, threonine, cystine) in borate buffer on characteristic absorption of aminogroup (190 nm), with limits of quantitation being on average 0.2%. The second scheme includes pre-capillary derivatization of amino acids using phenylisothiocyanate (PITC) and separation of phenylthiocarbamyl (PTC)-derivatives obtained by CZE with a detection on 254 nm, which allows to widen a list of detectable components up to 19 (without tryptophan) and significantly improve detection limits down to 0.01%. Acid hydrolysis was used for a sample preparation. The results of analysis of fodders were compared using such methods, as CZE, ion exchange chromatography (amino acid analyzer) and reversed-phase (RP)-HPLC (with gradient technique of elution). PMID:14698247

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

    PubMed

    Alonso, Saúl; Rendueles, Manuel; Díaz, Mario

    2015-01-01

    Microbial production of organic acids has become a fast-moving field due to the increasing role of these compounds as platform chemicals. In recent years, the portfolio of specialty fermentation-derived carboxylic acids has increased considerably, including the production of glyceric, glucaric, succinic, butyric, xylonic, fumaric, malic, itaconic, lactobionic, propionic and adipic acid through innovative fermentation strategies. This review summarizes recent trends in the use of novel microbial platforms as well as renewable and waste materials for efficient and cost-effective bio-based production of emerging high-value organic acids. Advances in the development of robust and efficient microbial bioprocesses for producing carboxylic acids from low-cost feedstocks are also discussed. The industrial market scenario is also reviewed, including the latest information on the stage of development for producing these emerging bio-products via large-scale fermentation. PMID:24754448

  1. Nucleation and growth of intragranular defect and insoluble atom clusters in nuclear oxide fuels

    NASA Astrophysics Data System (ADS)

    Garcia, P.; Martin, G.; Sabathier, C.; Carlot, G.; Michel, A.; Martin, P.; Dorado, B.; Freyss, M.; Bertolus, M.; Skorek, R.; Noirot, J.; Noirot, L.; Kaitasov, O.; Maillard, S.

    2012-04-01

    Uranium and plutonium oxides are subjected to high levels of radiation damage due to the slowing of fission fragments. In addition the composition of the material evolves over time as a result of fission events. Rare gases which constitute an abundant class of fission products are particularly insoluble and therefore tend either to be released from the fuel or form small nanometre size clusters. Bubbles are liable to grow and become trapping sites for migrating defects or other insoluble atoms. Interactions between migrating atoms, defects and existing clusters will determine the rate and extent to which clusters grow. Because the transfer of gas from within the grain to the grain boundaries is thought of as being the rate limiting process for fission gas release, a review of phenomena occurring on the sub-grain scale is carried out. The microstructural modifications induced by neutron irradiations of UO2 fuels are discussed with an emphasis on their relation to fission gas release. Based mainly on TEM studies, the phenomena which are usually taken into account in fission gas behaviour models are looked at and the limitations of these models outlined. More recent experimental and modelling approaches involving ion-irradiation experiments and atomic scale modelling are presented. It is shown that combining these approaches may lead, despite the complexity inherent to the system, to a better understanding of basic radiation induced microstructural changes, clustering events, and rare gas behaviour.

  2. Surface fractal dimension, water adsorption efficiency, and cloud nucleation activity of insoluble aerosol.

    PubMed

    Laaksonen, Ari; Malila, Jussi; Nenes, Athanasios; Hung, Hui-Ming; Chen, Jen-Ping

    2016-01-01

    Surface porosity affects the ability of a substance to adsorb gases. The surface fractal dimension D is a measure that indicates the amount that a surface fills a space, and can thereby be used to characterize the surface porosity. Here we propose a new method for determining D, based on measuring both the water vapour adsorption isotherm of a given substance, and its ability to act as a cloud condensation nucleus when introduced to humidified air in aerosol form. We show that our method agrees well with previous methods based on measurement of nitrogen adsorption. Besides proving the usefulness of the new method for general surface characterization of materials, our results show that the surface fractal dimension is an important determinant in cloud drop formation on water insoluble particles. We suggest that a closure can be obtained between experimental critical supersaturation for cloud drop activation and that calculated based on water adsorption data, if the latter is corrected using the surface fractal dimension of the insoluble cloud nucleus. PMID:27138171

  3. Surface fractal dimension, water adsorption efficiency, and cloud nucleation activity of insoluble aerosol

    NASA Astrophysics Data System (ADS)

    Laaksonen, Ari; Malila, Jussi; Nenes, Athanasios; Hung, Hui-Ming; Chen, Jen-Ping

    2016-05-01

    Surface porosity affects the ability of a substance to adsorb gases. The surface fractal dimension D is a measure that indicates the amount that a surface fills a space, and can thereby be used to characterize the surface porosity. Here we propose a new method for determining D, based on measuring both the water vapour adsorption isotherm of a given substance, and its ability to act as a cloud condensation nucleus when introduced to humidified air in aerosol form. We show that our method agrees well with previous methods based on measurement of nitrogen adsorption. Besides proving the usefulness of the new method for general surface characterization of materials, our results show that the surface fractal dimension is an important determinant in cloud drop formation on water insoluble particles. We suggest that a closure can be obtained between experimental critical supersaturation for cloud drop activation and that calculated based on water adsorption data, if the latter is corrected using the surface fractal dimension of the insoluble cloud nucleus.

  4. Surface fractal dimension, water adsorption efficiency, and cloud nucleation activity of insoluble aerosol

    PubMed Central

    Laaksonen, Ari; Malila, Jussi; Nenes, Athanasios; Hung, Hui-Ming; Chen, Jen-Ping

    2016-01-01

    Surface porosity affects the ability of a substance to adsorb gases. The surface fractal dimension D is a measure that indicates the amount that a surface fills a space, and can thereby be used to characterize the surface porosity. Here we propose a new method for determining D, based on measuring both the water vapour adsorption isotherm of a given substance, and its ability to act as a cloud condensation nucleus when introduced to humidified air in aerosol form. We show that our method agrees well with previous methods based on measurement of nitrogen adsorption. Besides proving the usefulness of the new method for general surface characterization of materials, our results show that the surface fractal dimension is an important determinant in cloud drop formation on water insoluble particles. We suggest that a closure can be obtained between experimental critical supersaturation for cloud drop activation and that calculated based on water adsorption data, if the latter is corrected using the surface fractal dimension of the insoluble cloud nucleus. PMID:27138171

  5. Insoluble and soluble roasted walnut proteins retain antibody reactivity.

    PubMed

    Downs, Melanie L; Simpson, Angela; Custovic, Adnan; Semic-Jusufagic, Aida; Bartra, Joan; Fernandez-Rivas, Montserrat; Taylor, Steve L; Baumert, Joseph L; Mills, E N Clare

    2016-03-01

    Thermal processing techniques commonly used during food production have the potential to impact food allergens by inducing physical and/or chemical changes to the proteins. English walnuts (Juglans regia) are among the most commonly allergenic tree nuts, but little information is available regarding how walnut allergens respond to thermal processing. This study evaluated the effects of dry roasting (132 or 180°C for 5, 10, or 20min) on the solubility and immunoreactivity of walnut proteins. A dramatic decrease in walnut protein solubility was observed following dry roasting at 180°C for 20min. However, both the soluble and insoluble protein fractions from roasted walnuts maintained substantial amounts of IgG immunoreactivity (using anti-raw and anti-roasted walnut antisera), with similar patterns of reactivity observed for human IgE from walnut-allergic individuals. Thus, walnut proteins are relatively stable under certain thermal processing conditions, and IgE reactivity remains present even when insoluble aggregates are formed. PMID:26471647

  6. Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces

    NASA Technical Reports Server (NTRS)

    Dussinger, Peter M.; Lindemuth, James E.

    1997-01-01

    The principal objective of this Phase 2 SBIR program was to develop and demonstrate a practically insoluble coating for nickel-based superalloys for Stirling engine heat pipe applications. Specific technical objectives of the program were: (1) Determine the solubility corrosion rates for Nickel 200, Inconel 718, and Udimet 72OLI in a simulated Stirling engine heat pipe environment, (2) Develop coating processes and techniques for capillary groove and screen wick structures, (3) Evaluate the durability and solubility corrosion rates for capillary groove and screen wick structures coated with an insoluble coating in cylindrical heat pipes operating under Stirling engine conditions, and (4) Design and fabricate a coated full-scale, partial segment of the current Stirling engine heat pipe for the Stirling Space Power Convertor program. The work effort successfully demonstrated a two-step nickel aluminide coating process for groove wick structures and interior wall surfaces in contact with liquid metals; demonstrated a one-step nickel aluminide coating process for nickel screen wick structures; and developed and demonstrated a two-step aluminum-to-nickel aluminide coating process for nickel screen wick structures. In addition, the full-scale, partial segment was fabricated and the interior surfaces and wick structures were coated. The heat pipe was charged with sodium, processed, and scheduled to be life tested for up to ten years as a Phase 3 effort.

  7. Comparative toxicity and carcinogenicity of soluble and insoluble cobalt compounds.

    PubMed

    Behl, Mamta; Stout, Matthew D; Herbert, Ronald A; Dill, Jeffrey A; Baker, Gregory L; Hayden, Barry K; Roycroft, Joseph H; Bucher, John R; Hooth, Michelle J

    2015-07-01

    Occupational exposure to cobalt is of widespread concern due to its use in a variety of industrial processes and the occurrence of occupational disease. Due to the lack of toxicity and carcinogenicity data following exposure to cobalt, and questions regarding bioavailability following exposure to different forms of cobalt, the NTP conducted two chronic inhalation exposure studies in rats and mice, one on soluble cobalt sulfate heptahydrate, and a more recent study on insoluble cobalt metal. Herein, we compare and contrast the toxicity profiles following whole-body inhalation exposures to these two forms of cobalt. In general, both forms were genotoxic in the Salmonella T98 strain in the absence of effects on micronuclei. The major sites of toxicity and carcinogenicity in both chronic inhalation studies were the respiratory tract in rats and mice, and the adrenal gland in rats. In addition, there were distinct sites of toxicity and carcinogenicity noted following exposure to cobalt metal. In rats, carcinogenicity was observed in the blood, and pancreas, and toxicity was observed in the testes of rats and mice. Taken together, these findings suggest that both forms of cobalt, soluble and insoluble, appear to be multi-site rodent carcinogens following inhalation exposure. PMID:25896363

  8. Evaluation of Acid Digestion Procedures to Estimate Mineral Contents in Materials from Animal Trials

    PubMed Central

    Palma, M. N. N.; Rocha, G. C.; Valadares Filho, S. C.; Detmann, E.

    2015-01-01

    Rigorously standardized laboratory protocols are essential for meaningful comparison of data from multiple sites. Considering that interactions of minerals with organic matrices may vary depending on the material nature, there could be peculiar demands for each material with respect to digestion procedure. Acid digestion procedures were evaluated using different nitric to perchloric acid ratios and one- or two-step digestion to estimate the concentration of calcium, phosphorus, magnesium, and zinc in samples of carcass, bone, excreta, concentrate, forage, and feces. Six procedures were evaluated: ratio of nitric to perchloric acid at 2:1, 3:1, and 4:1 v/v in a one- or two-step digestion. There were no direct or interaction effects (p>0.01) of nitric to perchloric acid ratio or number of digestion steps on magnesium and zinc contents. Calcium and phosphorus contents presented a significant (p<0.01) interaction between sample type and nitric to perchloric acid ratio. Digestion solution of 2:1 v/v provided greater (p<0.01) recovery of calcium and phosphorus from bone samples than 3:1 and 4:1 v/v ratio. Different acid ratios did not affect (p>0.01) calcium or phosphorus contents in carcass, excreta, concentrate, forage, and feces. Number of digestion steps did not affect mineral content (p>0.01). Estimated concentration of calcium, phosphorus, magnesium, and zinc in carcass, excreta, concentrated, forage, and feces samples can be performed using digestion solution of nitric to perchloric acid 4:1 v/v in a one-step digestion. However, samples of bones demand a stronger digestion solution to analyze the mineral contents, which is represented by an increased proportion of perchloric acid, being recommended a digestion solution of nitric to perchloric acid 2:1 v/v in a one-step digestion. PMID:26333671

  9. 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 ...

  10. URBAN AEROSOL ACIDS: ANALYSIS OF NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY STANDARD REFERENCE MATERIAL 1649

    EPA Science Inventory

    Urban air particulate matter, collected from Washington, D.C. and certified by the National Institute of Standards and Technology (NIST) as Standard Reference Material 1649, was extracted and fractionated into acid, base and neutral fractions. ach fraction was tested for biologic...

  11. Modification of wheat gluten with citric acid to produce superabsorbent materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Wheat gluten was reacted with citric acid to produce natural superabsorbent materials able to absorb up to 78 times its weight in water. The properties of the modified gluten samples were characterized using Fourier Transform Infra-red (FTIR) spectroscopy, thermogravimetric analysis, and water uptak...

  12. The influence of acid treatments over vermiculite based material as adsorbent for cationic textile dyestuffs.

    PubMed

    Stawiński, Wojciech; Freitas, Olga; Chmielarz, Lucjan; Węgrzyn, Agnieszka; Komędera, Kamila; Błachowski, Artur; Figueiredo, Sónia

    2016-06-01

    The influence of different acid treatments over vermiculite was evaluated. Equilibrium, kinetic and column studies have been conducted. The results showed that vermiculite first treated with nitric acid and then with citric acid has higher adsorption capacity, presenting maximum adsorption capacities in column experiments: for Astrazon Red (AR), 100.8 ± 0.8 mg g(-1) and 54 ± 1 mg g(-1) for modified and raw material, respectively; for Methylene Blue (MB) 150 ± 4 mg g(-1) and 55 ± 2 mg g(-1) for modified and raw material, respectively. Materials characterization by X-ray diffraction, UV-vis-diffuse reflectance spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy, X-ray fluorescence, N2 adsorption and CEC determination, has been performed. The results suggest the existence of exchange of interlayer cations, leaching of metals from vermiculite's sheets and formation of an amorphous phase in the material. Adsorption follows pseudo 2(nd) order model kinetics for both dyestuffs and equilibrium occurs accordingly to Langmuir's model for AR and Freundlich's model for MB. In column systems Yan's model is the best fit. The enhanced properties of acid treated vermiculite offer new perspectives for the use of this adsorbent in wastewater treatment. PMID:27015571

  13. Long-term stability of earthen materials in contact with acidic tailings solutions

    SciTech Connect

    Peterson, S.R.; Erikson, R.L.; Gee, G.W.

    1982-11-01

    The objectives of the studies documented in this report were to use experimental and geochemical computer modeling tools to assess the long-term environmental impact of leachate movement from acidic uranium mill tailings. Liner failure (i.e., an increase in the permeability of the liner material) was not found to be a problem when various acidic tailings solutions leached through liner materials for periods up to 3 years. On the contrary, materials that contained over 30% clay showed a decrease in permeability with time in the laboratory columns. The high clay materials tested appear suitable for lining tailings impoundment ponds. The decreases in permeability are attributed to pore plugging resulting from the precipitation of minerals and solids. This precipitation takes place due to the increase in pH of the tailings solution brought about by the buffering capacity of the soil. Geochemical modeling predicts, and x-ray characterization confirms, that precipitation of solids from solution is occurring in the acidic tailings solution/liner interactions studied. In conclusion the same mineralogical changes and contaminant reactions predicted by geochemical modeling and observed in laboratory studies were found at a drained evaporation pond (Lucky Mc in Wyoming) with a 4 year history of acid attack.

  14. Preparation and Ion Recognition Characteristics of a Trichloroacetic Acid Surface-Imprinted Material.

    PubMed

    Gao, Baojiao; Zhang, Tintin; Chen, Tao

    2015-05-01

    In this work, a trichloroacetic acid (TCAA) surface-imprinted material with high performance was prepared. In an aqueous solution, the molecules of the cationic monomer acryloyloxyethyl-trimethyl ammonium chloride (DAC) arranged around the template TCAA anion via electrostatic interaction. By initiating of the surface-initiating system of -NH2/S2O8(2-), the graft/cross-linking polymerization of DAC and the crosslinker N,N'-Methylenebisacrylamide and the TCAA surface-imprinting were simultaneously carried out on SiO2 particles, forming TCAA anion surface-imprinted material IIP-PDAC/ SiO2. With monochloroacetic acid (MCAA) and phenylacetic acid (PAA) as two contrast acids, the recognition character of the imprinted material IIP-PDAC/SiO2 was investigated. This imprinted material possesses special recognition selectivity and excellent binding affinity for TCAA anion. The binding amount of IIP-PDAC/SiO2 particles for TCAA reaches 0.93 mmol/g, whereas their binding amounts for MCAA and PAA are only 0.48 mmol/g and 0.15 mmol/g, respectively. The selectivity coefficients of IIP-PDAC/SiO2 for TCAA relative to MCAA and PAA anions are 3.61 and 9.12, respectively. PMID:26460460

  15. Prediction of acid hydrolysis of lignocellulosic materials in batch and plug flow reactors.

    PubMed

    Jaramillo, Oscar Johnny; Gómez-García, Miguel Ángel; Fontalvo, Javier

    2013-08-01

    This study unifies contradictory conclusions reported in literature on acid hydrolysis of lignocellulosic materials, using batch and plug flow reactors, regarding the influence of the initial liquid ratio of acid aqueous solution to solid lignocellulosic material on sugar yield and concentration. The proposed model takes into account the volume change of the reaction media during the hydrolysis process. An error lower than 8% was found between predictions, using a single set of kinetic parameters for several liquid to solid ratios, and reported experimental data for batch and plug flow reactors. For low liquid-solid ratios, the poor wetting and the acid neutralization, due to the ash presented in the solid, will both reduce the sugar yield. Also, this study shows that both reactors are basically equivalent in terms of the influence of the liquid to solid ratio on xylose and glucose yield. PMID:23770535

  16. Biomolecular interactions of emerging two-dimensional materials with aromatic amino acids

    NASA Astrophysics Data System (ADS)

    Mallineni, Sai Sunil Kumar; Karakaya, Mehmet; Podila, Ramakrishna; Rao, Apparao

    The present work experimentally investigates the interaction of aromatic amino acids, viz., tyrosine, tryptophan, and phenylalanine with novel two-dimensional (2D) materials including graphene (G), graphene oxide (GO), and boron nitride (BN). Photoluminescence, micro-Raman spectroscopy and cyclic voltammetry were employed to investigate the nature of interactions and possible charge transfer between 2D materials and amino acids. Consistent with previous theoretical studies, graphene and BN were observed to interact with amino acids through π- π interactions. Furthermore, we found that GO exhibits strong interactions with tryptophan and tyrosine as compared to graphene and BN, which we attribute to the formation of H-bonds between tryptophan and GO as shown theoretically in Ref. 2. On the other hand, phenylalanine did not exhibit much difference in interactions with G, GO, and BN. Clemson Nanomaterials Center, Clemson University, Clemson, SC, USA.

  17. A modified enzyme-linked immunosorbent assay adapted for immunodetection of low amounts of water-insoluble proteins.

    PubMed

    Godfrin, Dominique; Sénéchal, Hélène; Sutra, Jean-Pierre; Busnel, Jean-Marc; Desvaux, François-Xavier; Peltre, Gabriel

    2007-09-30

    A mixture of thiourea, urea and CHAPS (TUC) is an excellent solvent compatible with isoelectrofocusing (IEF) separation of water-insoluble protein extracts, and their subsequent two-dimensional gel electrophoresis is an important step in proteomic studies. The main aim of this work was to quantify extremely low amounts of water-insoluble proteins contained, for instance, in samples collected in bio-aerosol samplers. High CHAPS concentrations solubilize many proteins. However, enzyme-linked immunosorbent assay (ELISA), which is the most popular immunodetection method of quantifying antigens, is unfortunately not compatible with these high CHAPS concentrations and with the low protein concentrations of TUC extracts. The most common mixture used to solubilize these proteins contains 2 mol l(-1) thiourea, 7 mol l(-1) urea and 5% w/v CHAPS. This paper shows that these components inhibit the adsorption and/or recognition of proteins on microtitration plates, preventing antigen quantification under classic ELISA conditions. We have tried several solvents (ethanol, isopropanol, acetonitrile and trichloroacetic acid) to make the TUC-soluble proteins stick to the ELISA plates, and ethanol was shown to be the most appropriate. In this study, we have defined a new ELISA protocol allowing rapid and sensitive detection of low concentrations (60-500 ng ml(-1)) of water-insoluble proteins extracted with high concentrations of TUC. PMID:17706662

  18. Morphological Study of Insoluble Organic Matter Residues from Primitive

    NASA Technical Reports Server (NTRS)

    Changela, H. G.; Stroud, R. M.; Peeters, Z.; Nittler, L. R.; Alexander, C. M. O'D.; DeGregorio, B. T.; Cody, G. D.

    2012-01-01

    Insoluble organic matter (IOM) constitutes a major proportion, 70-99%, of the total organic carbon found in primitive chondrites [1, 2]. One characteristic morphological component of IOM is nanoglobules [3, 4]. Some nanoglobules exhibit large N-15 and D enrichments relative to solar values, indicating that they likely originated in the ISM or the outskirts of the protoplanetary disk [3]. A recent study of samples from the Tagish Lake meteorite with varying levels of hydrothermal alteration suggest that nanoglobule abundance decreases with increasing hydrothermal alteration [5]. The aim of this study is to further document the morphologies of IOM from a range of primitive chondrites in order to determine any correlation of morphology with petrographic grade and chondrite class that could constrain the formation and/or alteration mechanisms.

  19. CLAY MINERALOGY OF INSOLUBLE RESIDUES IN MARINE EVAPORITES.

    USGS Publications Warehouse

    Bodine, Marc W., Jr.

    1985-01-01

    Insoluble residues from three sequences of Paleozoic marine evaporites (Retsof salt bed in western New York, Salado Formation in south-eastern New Mexico, and Paradox Member of the Hermosa Formation in southeastern Utah) are rich in trioctahedral clays. Chlorite (clinochlore), corrensite (mixed-layer chlorite-trioctahedral smectite), talc, and illite (the only dioctahedral clay) are the dominant clay minerals; serpentine, discrete trioctahedral smectite (saponite), and interstratified talc-trioctahedral smectite are sporadically abundant. These clay-mineral assemblages differ chemically and mineralogically from those observed in most continental and normal marine rocks, which commonly contain kaolinite, dioctahedral smectite (beidellite-montmorillonite), illite, mixed-layer illite-dioctahedral smectite, and, in most cases, no more than minor quantities of trioctahedral clay minerals. The distinctive clay mineralogy in these evaporite sequences suggests a largely authigenic origin. These clay minerals are thought to have formed during deposition and early diagenesis through interaction between argillaceous detritus and Mg-rich marine evaporite brines.

  20. Insoluble starch composite foams produced through microwave expansion.

    PubMed

    Deng, Yuzhi; Catchmark, Jeffrey M

    2014-10-13

    An insoluble biocomposite composed of potato starch and chitosan was prepared by microwave treatment. The effect of pH on swelling (liquid absorption) behavior of the composites was investigated at pH 2, pH 6.8 and pH 12. Analysis revealed that the solution uptake ratio of composites depends both on the aqueous pH value and the content of the chitosan. Composites exhibited a relatively high swelling ratio at pH environments lower than the pK(a) of amine groups on chitosan (about 6.3). Glucose analysis by ion exchange chromatography showed that there was little hydrolysis of such composites at low pH. When immersed in the same pH solution, composites with higher chitosan content exhibited higher swelling ratios. The microstructure of composites produced was also investigated by FE-SEM. PMID:25037426

  1. New insights into the characterization of 'insoluble black HCN polymers'.

    PubMed

    Ruiz-Bermejo, Marta; de la Fuente, José L; Rogero, Celia; Menor-Salván, César; Osuna-Esteban, Susana; Martín-Gago, José A

    2012-01-01

    The data presented here provide a novel contribution to the understanding of the structural features of HCN polymers and could be useful in further development of models for prebiotic chemistry. The interpretation of spectroscopic and analytical data, along with previous results reported by other authors, allowed us to propose a mechanism for the aqueous polymerization of HCN from its primary and simplest isolated oligomer, the diaminomaleonitrile (DAMN) tetramer. We suggest that 'insoluble black HCN polymers' are formed by an unsaturated complex matrix, which retains a significant amount of H(2) O and important bioorganic compounds or their precursors. This polymeric matrix can be formed by various motifs of imidazoles and cyclic amides, among others. The robust formation of HCN polymers assayed under several conditions seems to explain the plausible ubiquity of these complex substances in space. PMID:22253100

  2. Synthesis of acid-base bifunctional mesoporous materials by oxidation and thermolysis

    SciTech Connect

    Yu, Xiaofang; Zou, Yongcun; Wu, Shujie; Liu, Heng; Guan, Jingqi; Kan, Qiubin

    2011-06-15

    Graphical abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst. The obtained sample of SO{sub 3}H-MCM-41-NH{sub 2} containing amine and sulfonic acids exhibits excellent catalytic activity in aldol condensation reaction. Research highlights: {yields} Synthesize acid-base bifunctional mesoporous materials SO{sub 3}H-MCM-41-NH{sub 2}. {yields} Oxidation and then thermolysis to generate acidic site and basic site. {yields} Exhibit good catalytic performance in aldol condensation reaction between acetone and various aldehydes. -- Abstract: A novel and efficient method has been developed for the synthesis of acid-base bifunctional catalyst SO{sub 3}H-MCM-41-NH{sub 2}. This method was achieved by co-condensation of tetraethylorthosilicate (TEOS), 3-mercaptopropyltrimethoxysilane (MPTMS) and (3-triethoxysilylpropyl) carbamicacid-1-methylcyclohexylester (3TAME) in the presence of cetyltrimethylammonium bromide (CTAB), followed by oxidation and then thermolysis to generate acidic site and basic site. X-ray diffraction (XRD) and transmission electron micrographs (TEM) show that the resultant materials keep mesoporous structure. Thermogravimetric analysis (TGA), X-ray photoelectron spectra (XPS), back titration, solid-state {sup 13}C CP/MAS NMR and solid-state {sup 29}Si MAS NMR confirm that the organosiloxanes were condensed as a part of the silica framework. The bifunctional sample (SO{sub 3}H-MCM-41-NH{sub 2}) containing amine and sulfonic acids exhibits excellent acid-basic properties, which make it possess high activity in aldol condensation reaction between acetone and various aldehydes.

  3. Evaluation of the acid properties of porous zirconium-doped and undoped silica materials

    SciTech Connect

    Fuentes-Perujo, D.; Santamaria-Gonzalez, J.; Merida-Robles, J.; Rodriguez-Castellon, E.; Jimenez-Lopez, A.; Maireles-Torres, P. . E-mail: maireles@uma.es; Moreno-Tost, R.

    2006-07-15

    A series of porous silica and Zr-doped silica molecular sieves, belonging to the MCM-41 and MSU families, were prepared and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N{sub 2} adsorption at 77 K. Their acid properties have been evaluated by NH{sub 3}-TPD, adsorption of pyridine and deuterated acetonitrile coupled to FT-IR spectroscopy and the catalytic tests of isopropanol decomposition and isomerization of 1-butene. The acidity of purely siliceous solids were, in all cases, very low, while the incorporation of Zr(IV) into the siliceous framework produced an enhancement of the acidity. The adsorption of basic probe molecules and the catalytic behaviour revealed that Zr-doped MSU-type silica was more acidic than the analogous Zr-MCM-41 solid, with a similar Zr content. This high acidity observed in the case of Zr-doped silica samples is due to the presence of surface zirconium atoms with a low coordination, mainly creating Lewis acid sites. - Graphical abstract: The adsorption of basic probe molecules and the catalytic behaviour have revealed that MSU-type materials are more acidic than the analogous MCM-41 solids, mainly after the incorporation of zirconium into the silica framework.

  4. Nucleic acids and smart materials: advanced building blocks for logic systems.

    PubMed

    Pu, Fang; Ren, Jinsong; Qu, Xiaogang

    2014-09-01

    Logic gates can convert input signals into a defined output signal, which is the fundamental basis of computing. Inspired by molecular switching from one state to another under an external stimulus, molecular logic gates are explored extensively and recognized as an alternative to traditional silicon-based computing. Among various building blocks of molecular logic gates, nucleic acid attracts special attention owing to its specific recognition abilities and structural features. Functional materials with unique physical and chemical properties offer significant advantages and are used in many fields. The integration of nucleic acids and functional materials is expected to bring about several new phenomena. In this Progress Report, recent progress in the construction of logic gates by combining the properties of a range of smart materials with nucleic acids is introduced. According to the structural characteristics and composition, functional materials are categorized into three classes: polymers, noble-metal nanomaterials, and inorganic nanomaterials. Furthermore, the unsolved problems and future challenges in the construction of logic gates are discussed. It is hoped that broader interests in introducing new smart materials into the field are inspired and tangible applications for these constructs are found. PMID:25042025

  5. Microencapsulation of human fibroblasts in a water-insoluble polyacrylate.

    PubMed

    Boag, A H; Sefton, M V

    1987-12-01

    Viable human diploid fibroblasts have been micro-encapsulated in EUDRAGIT RL, a commercially available water-insoluble polyacrylate, by an interfacial precipitation technique. Cells in medium and polymer solution (in diethyl phthalate) were coextruded and formed into droplets by a coaxial air stream. The droplets fell into a corn-oil/mineral-oil mixture to extract the solvent to precipitate the polymer around the cells. Capsules were ca. 500 mum in diameter depending on the air flowrate with a ca. 10-mum thick wall. When collagen (1 mg/mL) was added to the cell suspension prior to encapsulation and base-washed corn oil was used, cell growth occurred with one doubling achieved after five to six days as the collagen gel contracted inside the capsule. In the absence of collagen, cells spread on the inner wall of the capsule but did not grow, presumably because the surface charge on the capsule was inadequate. In similar fashion fibroblasts spread but did not grow on films of EUDRAGIT RL but did grow on blends of EUDRAGIT RL and EUDRAGIT E containing 10-30% of the latter more highly aminated polyacrylate. Although not suitable for anchorage-dependent cell growth by itself, EUDRAGIT RL has been suitable as a model polymer to demonstrate the feasibility of using water insoluble polyacrylates and organic solvents and nonsolvents for the micro-encapsulation of fibroblasts. Such microcapsules are of potential interest as a mode of large scale tissue culture for the production of novel therapeutic agents. PMID:18581534

  6. 31P NMR characterization and efficiency of new types of water-insoluble phosphate fertilizers to supply plant-available phosphorus in diverse soil types.

    PubMed

    Erro, Javier; Baigorri, Roberto; Yvin, Jean-Claude; Garcia-Mina, Jose M

    2011-03-01

    Hydroponic plant experiments demonstrated the efficiency of a type of humic acid-based water-insoluble phosphate fertilizers, named rhizosphere controlled fertilizers (RCF), to supply available phosphorus (P) to different plant species. This effect was well correlated to the root release of specific organic acids. In this context, the aims of this study are (i) to study the chemical nature of RCF using solid-state (31)P NMR and (ii) to evaluate the real efficiency of RCF matrix as a source of P for wheat plants cultivated in an alkaline and acid soil in comparison with traditional water-soluble (simple superphosphate, SSP) and water-insoluble (dicalcium phosphate, DCP) P fertilizers. The (31)P NMR study revealed the formation of multimetal (double and triple, MgZn and/or MgZnCa) phosphates associated with chelating groups of the humic acid through the formation of metal bridges. With regard to P fertilizer efficiency, the results obtained show that the RCF matrix produced higher plant yields than SSP in both types of soil, with DCP and the water-insoluble fraction from the RCF matrix (WI) exhibiting the best results in the alkaline soil. By contrast, in the acid soil, DCP showed very low efficiency, WI performed on a par with SSP, and RCF exhibited the highest efficiency, thus suggesting a protector effect of humic acid from soil fixation. PMID:21254775

  7. The distribution of common construction materials at risk to acid deposition in the United States

    NASA Astrophysics Data System (ADS)

    Lipfert, Frederick W.; Daum, Mary L.

    Information on the geographic distribution of various types of exposed materials is required to estimate the economic costs of damage to construction materials from acid deposition. This paper focuses on the identification, evaluation and interpretation of data describing the distributions of exterior construction materials, primarily in the United States. This information could provide guidance on how data needed for future economic assessments might be acquired in the most cost-effective ways. Materials distribution surveys from 16 cities in the U.S. and Canada and five related databases from government agencies and trade organizations were examined. Data on residential buildings are more commonly available than on nonresidential buildings; little geographically resolved information on distributions of materials in infrastructure was found. Survey results generally agree with the appropriate ancillary databases, but the usefulness of the databases is often limited by their coarse spatial resolution. Information on those materials which are most sensitive to acid deposition is especially scarce. Since a comprehensive error analysis has never been performed on the data required for an economic assessment, it is not possible to specify the corresponding detailed requirements for data on the distributions of materials.

  8. Effect of Acidic Environment on Dislocation Resistance of Endosequence Root Repair Material and Mineral Trioxide Aggregate

    PubMed Central

    Shokouhinejad, Noushin; Yazdi, Kazem Ashofteh; Nekoofar, Mohammad Hossein; Matmir, Shakiba; Khoshkhounejad, Mehrfam

    2014-01-01

    Objective: The aim of this study was to compare the effect of an acidic environment on dislocation resistance (push-out bond strength) of EndoSequence Root Repair Material (ERRM putty and ERRM paste), a new bioceramic-based material, to that of mineral tri-oxide aggregate (MTA). Materials and Methods: One-hundred twenty root dentin slices with standardized canal spaces were divided into 6 groups (n = 20 each) and filled with tooth-colored ProRoot MTA (groups 1 and 2), ERRM putty (groups 3 and 4), or ERRM paste (groups 5 and 6). The specimens of groups 1, 3, and 5 were exposed to phosphate buffered saline (PBS) solution (pH=7.4) and those of groups 2, 4, and 6 were exposed to butyric acid (pH= 4.4). The specimens were then incubated for 4 days at 37°C. The push-out bond strength was then measured using a universal testing machine. Failure modes after the push-out test were examined under a light microscope at ×40 magnification. The data for dislocation resistance were analyzed using the t-test and one-way analysis of variance. Results: In PBS environment (pH=7.4), there were no significant differences among materials (P=0.30); but the mean push-out bond strength of ERRM putty was significantly higher than that of other materials in an acidic environment (P<0.001). Push-out bond strength of MTA and ERRM paste decreased after exposure to an acidic environment; whereas ERRM putty was not affected by acidic pH. The bond failure mode was predominantly cohesive for all groups except for MTA in an acidic environment; which showed mixed bond failure in most of the specimens. Conclusion: The force needed for dislocation of MTA and ERRM paste was significantly lower in samples stored in acidic pH; however, push-out bond strength of ERRM putty was not influenced by acidity. PMID:24910691

  9. Rates of dissolution and biodegradation of water-insoluble organic compounds.

    PubMed Central

    Thomas, J M; Yordy, J R; Amador, J A; Alexander, M

    1986-01-01

    We conducted a study of the relationship between the dissolution rates of organic compounds that are sparingly soluble in water and the biodegradation of these compounds by mixed cultures of bacteria. The rates of dissolution of naphthalene and 4-chlorobiphenyl were directly related to their surface areas. The bacteria caused a decline in the concentration of the soluble substrate. The rate of bacterial growth fell abruptly when 4-chlorobiphenyl or naphthalene was no longer detectable in solution. The population continued to increase in media with different surface areas of insoluble 4-chlorobiphenyl, but the final counts were higher in media in which the surface areas of the substrate were larger. The rates of dissolution of palmitic acid, octadecane, di(2-ethylhexyl) phthalate, and 1-naphthyl N-methylcarbamate were determined in the absence of microorganisms. A mixed culture of microorganisms mineralized palmitic acid, di(2-ethylhexyl) phthalate, and Sevin (1-naphthyl N-methylcarbamate) at a logarithmic rate, but octadecane mineralization was linear. The rates of mineralization at the end of the active phase of the biodegradation were lower than the rate of dissolution of palmitic acid but higher than the rate of dissolution of octadecane in the uninoculated medium. We suggest that spontaneous dissolution rates are only one of the factors that govern the rates of biodegradation. PMID:3092736

  10. Fermentative production of lactic acid from renewable materials: recent achievements, prospects, and limits.

    PubMed

    Wang, Ying; Tashiro, Yukihiro; Sonomoto, Kenji

    2015-01-01

    The development and implementation of renewable materials for the production of versatile chemical resources have gained considerable attention recently, as this offers an alternative to the environmental problems caused by the petroleum industry and the limited supply of fossil resources. Therefore, the concept of utilizing biomass or wastes from agricultural and industrial residues to produce useful chemical products has been widely accepted. Lactic acid plays an important role due to its versatile application in the food, medical, and cosmetics industries and as a potential raw material for the manufacture of biodegradable plastics. Currently, the fermentative production of optically pure lactic acid has increased because of the prospects of environmental friendliness and cost-effectiveness. In order to produce lactic acid with high yield and optical purity, many studies focus on wild microorganisms and metabolically engineered strains. This article reviews the most recent advances in the biotechnological production of lactic acid mainly by lactic acid bacteria, and discusses the feasibility and potential of various processes. PMID:25077706

  11. Biomolecular Interactions and Biological Responses of Emerging Two-Dimensional Materials and Aromatic Amino Acid Complexes.

    PubMed

    Mallineni, Sai Sunil Kumar; Shannahan, Jonathan; Raghavendra, Achyut J; Rao, Apparao M; Brown, Jared M; Podila, Ramakrishna

    2016-07-01

    The present work experimentally investigates the interaction of aromatic amino acids viz., tyrosine, tryptophan, and phenylalnine with novel two-dimensional (2D) materials including graphene, graphene oxide (GO), and boron nitride (BN). Photoluminescence, micro-Raman spectroscopy, and cyclic voltammetry were employed to investigate the nature of interactions and possible charge transfer between 2D materials and amino acids. Graphene and GO were found to interact strongly with aromatic amino acids through π-π stacking, charge transfer, and H-bonding. Particularly, it was observed that both physi and chemisorption are prominent in the interactions of GO/graphene with phenylalanine and tryptophan while tyrosine exhibited strong chemisorption on graphene and GO. In contrast, BN exhibited little or no interactions, which could be attributed to localized π-electron clouds around N atoms in BN lattice. Lastly, the adsorption of amino acids on 2D materials was observed to considerably change their biological response in terms of reactive oxygen species generation. More importantly, these changes in the biological response followed the same trends observed in the physi and chemisorption measurements. PMID:27281436

  12. Insoluble coatings for Stirling engine heat pipe condenser surfaces. Final report

    SciTech Connect

    Dussinger, P.M.

    1993-09-01

    The work done by Thermacore, Inc., Lancaster, Pennsylvania, for the Phase 1, 1992 SBIR National Aeronautics and Space Administration Contract, Insoluble Coatings for Stirling Engine Heat Pipe Condenser Surfaces' is described. The work was performed between January 1992 and July 1992. Stirling heat engines are being developed for electrical power generation use on manned and unmanned earth orbital and planetary missions. Dish Stirling solar systems and nuclear reactor Stirling systems are two of the most promising applications of the Stirling engine electrical power generation technology. The sources of thermal energy used to drive the Stirling engine typically are non-uniform in temperature and heat flux. Liquid metal heat pipe receivers are used as thermal transformers and isothermalizers to deliver the thermal energy at a uniform high temperature to the heat input section of the Stirling engine. The use of a heat pipe receiver greatly enhances system efficiency and potential life span. One issue that is raised during the design phase of heat pipe receivers is the potential solubility corrosion of the Stirling engine heat input section by the liquid metal working fluid. This Phase 1 effort initiated a program to evaluate and demonstrate coatings, applied to nickel based Stirling engine heater head materials, that are practically 'insoluble' in sodium, potassium, and NaK. This program initiated a study of nickel aluminide as a coating and developed and demonstrated a heat pipe test vehicle that can be used to test candidate materials and coatings. Nickel 200 and nickel aluminide coated Nickel 200 were tested for 1000 hours at 800 C at a condensation heat flux of 25 W/sq cm. Subsequent analyses of the samples showed no visible sign of solubility corrosion of either coated or uncoated samples. The analysis technique, photomicrographs at 200X, has a resolution of better than 2.5 microns (.0001 in).

  13. Pretreatment of solid carbonaceous material with dicarboxylic aromatic acids to prevent scale formation

    DOEpatents

    Brunson, Roy J.

    1982-01-01

    Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with a pretreating agent selected from the group consisting of phthalic acid, phthalic anhydride, pyromellitic acid and pyromellitic anhydride. The pretreatment is believed to convert the scale-forming components to the corresponding phthalate and/or pyromellitate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 1 to about 2 atmospheres. Temperature during pretreatment will generally be within the range from about 5.degree. to about 80.degree. C.

  14. Tank 12H Acidic Chemical Cleaning Sample Analysis And Material Balance

    SciTech Connect

    Martino, C. J.; Reboul, S. H.; Wiersma, B. J.; Coleman, C. J.

    2013-11-08

    A process of Bulk Oxalic Acid (BOA) chemical cleaning was performed for Tank 12H during June and July of 2013 to remove all or a portion of the approximately 4400 gallon sludge heel. Three strikes of oxalic acid (nominally 4 wt% or 2 wt%) were used at 55°C and tank volumes of 96- to 140-thousand gallons. This report details the sample analysis of a scrape sample taken prior to BOA cleaning and dip samples taken during BOA cleaning. It also documents a rudimentary material balance for the Tank 12H cleaning results.

  15. Formic acid as a hydrogen storage material - development of homogeneous catalysts for selective hydrogen release.

    PubMed

    Mellmann, Dörthe; Sponholz, Peter; Junge, Henrik; Beller, Matthias

    2016-07-11

    Formic acid (FA, HCO2H) receives considerable attention as a hydrogen storage material. In this respect, hydrogenation of CO2 to FA and dehydrogenation of FA are crucial reaction steps. In the past decade, for both reactions, several molecularly defined and nanostructured catalysts have been developed and intensively studied. From 2010 onwards, this review covers recent advancements in this area using homogeneous catalysts. In addition to the development of catalysts for H2 generation, reversible H2 storage including continuous H2 production from formic acid is highlighted. Special focus is put on recent progress in non-noble metal catalysts. PMID:27119123

  16. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates

    PubMed Central

    Alvelo-Maurosa, Jesús G.; Lee, Scott J.; Hazen, Samuel P.

    2015-01-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  17. Direct Image-Based Enumeration of Clostridium phytofermentans Cells on Insoluble Plant Biomass Growth Substrates.

    PubMed

    Alvelo-Maurosa, Jesús G; Lee, Scott J; Hazen, Samuel P; Leschine, Susan B

    2016-02-01

    A dual-fluorescent-dye protocol to visualize and quantify Clostridium phytofermentans ISDg (ATCC 700394) cells growing on insoluble cellulosic substrates was developed by combining calcofluor white staining of the growth substrate with cell staining using the nucleic acid dye Syto 9. Cell growth, cell substrate attachment, and fermentation product formation were investigated in cultures containing either Whatman no. 1 filter paper, wild-type Sorghum bicolor, or a reduced-lignin S. bicolor double mutant (bmr-6 bmr-12 double mutant) as the growth substrate. After 3 days of growth, cell numbers in cultures grown on filter paper as the substrate were 6.0- and 2.2-fold higher than cell numbers in cultures with wild-type sorghum and double mutant sorghum, respectively. However, cells produced more ethanol per cell when grown with either sorghum substrate than with filter paper as the substrate. Ethanol yields of cultures were significantly higher with double mutant sorghum than with wild-type sorghum or filter paper as the substrate. Moreover, ethanol production correlated with cell attachment in sorghum cultures: 90% of cells were directly attached to the double mutant sorghum substrate, while only 76% of cells were attached to wild-type sorghum substrate. With filter paper as the growth substrate, ethanol production was correlated with cell number; however, with either wild-type or mutant sorghum, ethanol production did not correlate with cell number, suggesting that only a portion of the microbial cell population was active during growth on sorghum. The dual-staining procedure described here may be used to visualize and enumerate cells directly on insoluble cellulosic substrates, enabling in-depth studies of interactions of microbes with plant biomass. PMID:26637592

  18. Characterization and Localization of Insoluble Organic Matrices Associated with Diatom Cell Walls: Insight into Their Roles during Cell Wall Formation

    PubMed Central

    Tesson, Benoit; Hildebrand, Mark

    2013-01-01

    Organic components associated with diatom cell wall silica are important for the formation, integrity, and function of the cell wall. Polysaccharides are associated with the silica, however their localization, structure, and function remain poorly understood. We used imaging and biochemical approaches to describe in detail characteristics of insoluble organic components associated with the cell wall in 5 different diatom species. Results show that an insoluble organic matrix enriched in mannose, likely the diatotepum, is localized on the proximal surface of the silica cell wall. We did not identify any organic matrix embedded within the silica. We also identified a distinct material consisting of glucose polymer with variable localization depending on the species. In some species this component was directly involved in the morphogenesis of silica structure while in others it appeared to be only a structural component of the cell wall. A novel glucose-rich structure located between daughter cells during division was also identified. This work for the first time correlates the structure, composition, and localization of insoluble organic matrices associated with diatom cell walls. Additionally we identified a novel glucose polymer and characterized its role during silica structure formation. PMID:23626714

  19. Recovery of organic acids

    DOEpatents

    Verser, Dan W.; Eggeman, Timothy J.

    2009-10-13

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  20. Recovery of organic acids

    SciTech Connect

    Verser, Dan W.; Eggeman, Timothy J.

    2011-11-01

    A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.

  1. Preparation, characterization, and thermal properties of starch microencapsulated fatty acids as phase change materials thermal energy storage applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stable starch-oil composites can be prepared from renewable resources by excess steam jet-cooking aqueous slurries of starch and vegetable oils or other hydrophobic materials. Fatty acids such as stearic acid are promising phase change materials (PCMs) for latent heat thermal energy storage applica...

  2. Use of Fly Ash as a Liming Material for Corn and Soybean Production on an Acidic Sandy Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fly ash (FA) produced from subbituminous coal combustion can potentially serve as a lime material for crop production in acidic soils in areas. A five-year study was conducted to determine if FA can be used as a liming material in an acid sandy soil under corn and soybean grain production. Fly ash...

  3. The well-coordinated linkage between acidogenicity and aciduricity via insoluble glucans on the surface of Streptococcus mutans

    PubMed Central

    Guo, Lihong; McLean, Jeffrey S.; Lux, Renate; He, Xuesong; Shi, Wenyuan

    2015-01-01

    Streptococcus mutans is considered the principal cariogenic bacterium for dental caries. Despite the recognition of their importance for cariogenesis, the possible coordination among S. mutans’ main virulence factors, including glucan production, acidogenicity and aciduricity, has been less well studied. In the present study, using S. mutans strains with surface-displayed pH-sensitive pHluorin, we revealed sucrose availability- and Gtf functionality-dependent proton accumulation on S. mutans surface. Consistent with this, using a pH-sensitive dye, we demonstrated that both in vivo cell-produced and in vitro enzymatically synthesized insoluble glucans displayed proton-concentrating ability. Global transcriptomics revealed proton accumulation triggers the up-regulation of genes encoding functions involved in acid tolerance response in a glucan-dependent manner. Our data suggested that this proton enrichment around S. mutans could pre-condition the bacterium for acid-stress. Consistent with this hypothesis, we found S. mutans strains defective in glucan production were more acid sensitive. Our study revealed for the first time that insoluble glucans is likely an essential factor linking acidogenicity with aciduricity. The coordination of these key virulence factors could provide new insights on how S. mutans may have become a major cariogenic pathogen. PMID:26657939

  4. Hydrogels from Amorphous Calcium Carbonate and Polyacrylic Acid: Bio-Inspired Materials for "Mineral Plastics".

    PubMed

    Sun, Shengtong; Mao, Li-Bo; Lei, Zhouyue; Yu, Shu-Hong; Cölfen, Helmut

    2016-09-19

    Given increasing environmental issues due to the large usage of non-biodegradable plastics based on petroleum, new plastic materials, which are economic, environmentally friendly, and recyclable are in high demand. One feasible strategy is the bio-inspired synthesis of mineral-based hybrid materials. Herein we report a facile route for an amorphous CaCO3 (ACC)-based hydrogel consisting of very small ACC nanoparticles physically cross-linked by poly(acrylic acid). The hydrogel is shapeable, stretchable, and self-healable. Upon drying, the hydrogel forms free-standing, rigid, and transparent objects with remarkable mechanical performance. By swelling in water, the material can completely recover the initial hydrogel state. As a matrix, thermochromism can also be easily introduced. The present hybrid hydrogel may represent a new class of plastic materials, the "mineral plastics". PMID:27444970

  5. Electrochemical degradation of trichloroacetic acid in aqueous media: influence of the electrode material.

    PubMed

    Esclapez, M D; Díez-García, M I; Sàez, V; Bonete, P; González-García, José

    2013-01-01

    The electrochemical degradation of trichloroacetic acid (TCAA) in water has been analysed through voltammetric studies with a rotating disc electrode and controlled-potential bulk electrolyses. The influence of the mass-transport conditions and initial concentration of TCAA for titanium, stainless steel and carbon electrodes has been studied. It is shown that the electrochemical reduction of TCAA takes place prior to the massive hydrogen evolution in the potential window for all electrode materials studied. The current efficiency is high (> 18%) compared with those normally reported in the literature, and the fractional conversion is above 50% for all the electrodes studied. Only dichloroacetic acid (DCAA) and chloride anions were routinely detected as reduction products for any of the electrodes, and reasonable values of mass balance error were obtained. Of the three materials studied, the titanium cathode gave the best results. PMID:23530352

  6. Insoluble surface carbon on steel sheet annealed in hydrogen-nitrogen atmosphere

    NASA Astrophysics Data System (ADS)

    Biber, H. E.; Takacs, R. C.; Dickey, A. E.

    1983-09-01

    The way in which heating in hydrogen-nitrogen atmosphere affects the pyrolysis of the residual lubricant on cold-reduced steel sheet was studied to discover the factors responsible for the formation of carbonaceous films on the steel surface. These films, referred to as insoluble surface carbon, cannot be removed with the usual solvents or water-base cleaners and adversely affect the paintability of the steel. A surprising result was the observation that the full-hard steel surface has a significant amount of insoluble surface carbon; amounts in excess of 0.010 gm/m2 (1 mg/ft2) were observed. The origin of this “initial” insoluble carbon can be traced to the pickling operation after hot rolling. During annealing much of the residual rolling lubricant on the surface is driven off by evaporation, but concurrently insoluble pyrolysis products are formed. The amount of insoluble pyrolysis product formed is directly related to the amount of “initial” insoluble carbon on the surface before annealing. The results show that at some point during annealing the total amount of insoluble carbon on the surface is more than double the amount of “initial” insoluble carbon. These insoluble pyrolysis products can also be driven from the surface at higher temperatures than are required for evaporation of the oil. The results suggest that removal of the “initial” insoluble carbon prior to cold reduction might be very beneficial with respect to decreasing the amount of insoluble carbon on the surface of steel sheet after annealing.

  7. Vinasse organic matter quality and mineralization potential, as influenced by raw material, fermentation and concentration processes.

    PubMed

    Parnaudeau, V; Condom, N; Oliver, R; Cazevieille, P; Recous, S

    2008-04-01

    Both dilute and concentrated vinasse can be spread on agricultural fields or used as organic fertilizer. The effects of different characteristics of the original raw material on the biochemical composition of vinasse and their C and N mineralization in soil were investigated. Vinasse samples were obtained from similar industrial fermentation processes based on the growth of microorganisms on molasses from different raw material (sugar beet or sugar cane) and vinasse concentration (dilute or concentrated). The nature of the raw material used for fermentation had the greatest effect on the nature and size of the resistant organic pool. This fraction included aromatic compounds originating from the raw material or from complex molecules and seemed to be quantitatively related to acid-insoluble N. Samples derived from sugar beet were richer in N compounds and induced greater net N mineralization. The effect of evaporation varied with the nature of the raw material. Concentration led to a slight increase in the abundance of phenolic compounds, acid-insoluble fraction, and a slight decrease in the labile fraction of vinasses partly or totally derived from sugar beet. The effect of the dilute vinasse from sugar cane was greater. The concentrated vinasse had a smaller labile fraction, induced N immobilization at the beginning of incubation, and exhibited greater N concentration in the acid-insoluble fraction than the dilute vinasse. PMID:17582760

  8. Boric acid corrosion of light water reactor pressure vessel head materials.

    SciTech Connect

    Park, J.-H.; Chopra, O. K.; Natesan, K.; Shack, W. J.; Cullen, Jr.; W. H.; Energy Technology; USNRC

    2005-01-01

    This work presents experimental data on electrochemical potential and corrosion rates for the materials found in the reactor pressure vessel head and control rod drive mechanism (CRDM) nozzles in boric acid solutions of varying concentrations at temperatures of 95-316 C. Tests were conducted in (a) high-temperature, high-pressure aqueous solutions with a range of boric acid concentrations, (b) high-temperature (150-316 C)H-B-Osolutions at ambient pressure, in wet and dry conditions, and (c) low-temperature (95 C) saturated, aqueous, boric acid solutions. These correspond to the following situations: (a) low leakage through the nozzle and nozzle/head annulus plugged, (b) low leakage through the nozzle and nozzle/head annulus open, and (c) significant cooling due to high leakage and nozzle/head annulus open. The results showed significant corrosion only for the low-alloy steel and no corrosion for Alloy 600 or 308 stainless steel cladding. Also, corrosion rates were significant in saturated boric acid solutions, and no material loss was observed in H-B-O solution in the absence of moisture. The results are compared with the existing corrosion/wastage data in the literature.

  9. Use of processed resistivity borehole imaging to assess the insoluble content of the massively bedded Preesall Halite NW England

    NASA Astrophysics Data System (ADS)

    Kingdon, Andrew; Evans, David J.

    2013-04-01

    With the decline of the UK's remaining conventional reserves of natural gas and associated growth of imports, the lack of adequate storage capacity is a matter of concern for ensuring energy security year-round. In a number of countries, subsurface caverns for gas storage have been created by solution mining of massive halite deposits and similar storage facilities are likely to become an important part of the UK's energy infrastructure. Crucial to the economic viability of such facilities is the percentage of insoluble material within the halite intervals, which influences strongly the relationship between cavern sump and working volumes: successful development of these caverns is dependent upon maximising the efficiency of cavern design and construction. The purity of a massive halite sequence can only be assessed either by direct means (i.e. coring) or indirectly by downhole geophysical logs The use of conventional geophysical logs in subsurface exploration is well established but literature generally relies on a very low resolution tools with a typical vertical logging sample interval of 15 centimetres. This means that such tools provide, at best, a "blurred" view of the sedimentary successions penetrated by the borehole and that discrete narrow bands of insoluble material will not be identifiable or distinguishable from zones of "dirtier" halite with disseminated mud materials. In 2008, Halite-Energy Group (formerly Canatxx Gas Storage Ltd) drilled the Burrows Marsh #1 borehole and acquired resistivity borehole imaging (FMI) logs through the Triassic Preesall Halite in the Preesall Saltfield, NW England. In addition to near full circumferal imaging capability, rather than a single measurement per increment, FMI logs allows millimetre to centimetre scale imaging of sedimentary features, that is one to two orders of magnitude higher vertical resolution. After binary segmentation of the FMI images to achieve a simple halite-insoluble ("mud") separation these were

  10. Toward an experimental synthesis of the chondritic insoluble organic matter

    NASA Astrophysics Data System (ADS)

    Biron, Kasia; Derenne, Sylvie; Robert, FrançOis; Rouzaud, Jean-NoëL.

    2015-08-01

    Based on the statistical model proposed for the molecular structure of the insoluble organic matter (IOM) isolated from the Murchison meteorite, it was recently proposed that, in the solar T-Tauri disk regions where (photo)dissociation of gaseous molecules takes place, aromatics result from the cyclization/aromatization of short aliphatics. This hypothesis is tested in this study, with n-alkanes being submitted to high-frequency discharge at low pressure. The contamination issue was eliminated using deuterated precursor. IOM was formed and studied using solid-state nuclear magnetic resonance, pyrolysis coupled to gas chromatography and mass spectrometry, RuO4 oxidation, and high-resolution transmission electron microscopy. It exhibits numerous similarities at the molecular level with the hydrocarbon backbone of the natural IOM, reinforcing the idea that the initial precursors of the IOM were originally chains in the gas. Moreover, a fine comparison between the chemical structure of several meteorite IOM suggests either that (i) the meteorite IOMs share a common precursor standing for the synthetic IOM or that (ii) the slight differences between the meteorite IOMs reflect differences in their environment at the time of their formation i.e., related to plasma temperature that, in turn, dictates the dissociation-recombination rates of organic fragments.

  11. Vibrational instabilities of a nonisothermal liquid layer with insoluble surfactant

    NASA Astrophysics Data System (ADS)

    Mikishev, Alexander; Nepomnyashchy, Alexander

    2015-11-01

    We consider an infinite horizontal layer of an incompressible liquid, the deformable upper free surface is covered by insoluble surfactant. The layer is subjected to vertical harmonic oscillations with fixed amplitude and frequency, as well as to a transverse gradient of temperature. We suppose that the surface tension of upper boundary linearly depends on temperature and surfactant concentration. Two types of waves on the surface are possible. The first one is capillary-gravity waves (transverse waves) excited by the usual Faraday instability mechanism, under the influence of the surfactant elasticity. The second type of waves is Marangoni waves (longitudinal waves) related to compressions - dilations of the surface. In this work we study the excitation of Marangoni waves by vibration and determine the existence conditions for each type of waves. The results are connected with our previous research on parametric excitation of Marangoni instability when the gradient of temperature is harmonically changed. The instability thresholds are calculated numerically using the Floquet method for disturbances with arbitrary wave numbers.

  12. Secreted expression of Leuconostoc mesenteroides glucansucrase in Lactococcus lactis for the production of insoluble glucans.

    PubMed

    Skory, Christopher D; Côté, Gregory L

    2015-12-01

    We expressed a glucansucrase, DsrI, from Leuconostoc mesenteroides that catalyzes formation of water-insoluble glucans from sucrose using a nisin-controlled gene expression system in Lactococcus lactis. These polymers have potential for production of biodegradable gels, fibers, and films. We optimized production of DsrI using several different background vectors, signal peptides, strains, induction conditions, and bioreactor parameters to increase extracellular accumulation. Optimal production of the enzyme utilized a high-copy plasmid, pMSP3535H3, which contains a nisin immunity gene, L. lactis LM0230, and bioreactors maintained at pH 6.0 to stabilize the enzyme. We were able to significantly improve growth using the lactic acid inhibitor heme and by continuous removal of lactic acid with anion exchange resins, but enzyme production was less than the controls. The recombinant enzyme under optimized conditions accumulated in the culture medium to approximately 380 mg/L, which was over 150-fold higher compared to the native L. mesenteroides strain. Methods are also included for purification of DsrI utilizing the glucan-binding domain of the enzyme. PMID:26239071

  13. Conquering the control of insoluble and soluble starch with novel applications of amylase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The new knowledge that there is markedly more insoluble starch than previously considered in products across both the sugarcane factory and refinery has processing implications. This includes the application of a-amylases in the factory to control not only soluble but insoluble starch. Studies wer...

  14. A method for the determination of soluble arabinoxylan released from insoluble substrates by xylanases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The propensity for xylanase to convert insoluble arabinoxylan to soluble oligosaccharides is an important parameter in many applications. Current methods for determining xylanase activity on insoluble substrates are labor intensive, non-specific, or utilize artificial substrates which may provide mu...

  15. A Simple Method for the Determination of Xylanase Activity on Insoluble Substrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The propensity for a xylanase to convert insoluble (arabino)xylan into soluble oligosaccharides is an important parameter in the baking, pulp and paper, prebiotics, and biofuel industries. Current methods for determining xylanase activity on insoluble substrates are labor intensive, non-specific, or...

  16. Effect of Naturally Acidic Agents on Microhardness and Surface Micromorphology of Restorative Materials

    PubMed Central

    Hengtrakool, Chanothai; Kukiattrakoon, Boonlert; Kedjarune-Leggat, Ureporn

    2011-01-01

    Objectives: This study investigated the titratable acidity and erosive potential of acidic agents on the microhardness and surface micromorphology of four restorative materials. Methods: Forty-seven discs of each restorative material; metal-reinforced glass ionomer cement (Ketac-S), resin-modified glass ionomer cement (Fuji II LC), resin composite (Filtek Z250) and amalgam (Valiant-Ph.D.), 12 mm in diameter and 2.5 mm in thickness, were divided into four groups (5 discs/group). Specimens were then immersed for 7 days into four storage media; deionized water (control), citrate buffer solution, green mango juice and pineapple juice. Microhardness testing before and after immersions was performed. Micromorphological changes were evaluated under a scanning electron microscope (SEM). Statistical significance among each group was analyzed using two-way repeated ANOVA and Tukey’s tests. Results: The Fuji II LC and the Ketac-S showed the highest reduction in microhardness (P<.05). The Valiant-Ph.D. and the Filtek Z250 showed some minor changes over the period of 7 days. The mango juice produced the greatest degradation effect (P<.05). Conclusions: This study suggested that for restorations in patients who have tooth surface loss, materials selected should be considered. In terms of materials evaluated, amalgam and resin composite are the most suitable for restorations. PMID:21311608

  17. 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. PMID:24308331

  18. Proteomic characterization of a triton-insoluble fraction from chloroplasts defines a novel group of proteins associated with macromolecular structures.

    PubMed

    Phinney, Brett S; Thelen, Jay J

    2005-01-01

    Proteomic analysis of a Triton X-100 insoluble, 30,000 x g pellet from purified pea chloroplasts resulted in the identification of 179 nonredundant proteins. This chloroplast fraction was mostly depleted of chloroplast membranes since only 23% and 9% of the identified proteins were also observed in envelope and thylakoid membranes, respectively. One of the most abundant proteins in this fraction was sulfite reductase, a dual function protein previously shown to act as a plastid DNA condensing protein. Approximately 35 other proteins known (or predicted) to be associated with high-density protein-nucleic acid particles (nucleoids) were also identified including a family of DNA gyrases, as well as proteins involved in plastid transcription and translation. Although nucleoids appeared to be the predominant component of 30k x g Triton-insoluble chloroplast preparations, multi-enzyme protein complexes were also present including each subunit to the pyruvate dehydrogenase and acetyl-CoA carboxylase multi-enzyme complexes, as well as a proposed assembly of the first three enzymes of the Calvin cycle. Approximately 18% of the proteins identified were annonated as unknown or hypothetical proteins and another 20% contained "putative" or "like" in the identifier tag. This is the first proteomic characterization of a membrane-depleted, high-density fraction from plastids and demonstrates the utility of this simple procedure to isolate intact macromolecular structures from purified organelles for analysis of protein-protein and protein-nucleic acid interactions. PMID:15822927

  19. The development and amino acid binding ability of nano-materials based on azo derivatives: theory and experiment.

    PubMed

    Shang, Xuefang; Du, Jinge; Yang, Wancai; Liu, Yun; Fu, Zhiyuan; Wei, Xiaofang; Yan, Ruifang; Yao, Ningcong; Guo, Yaping; Zhang, Jinlian; Xu, Xiufang

    2014-05-01

    Two nano-material-containing azo groups have been designed and developed, and the binding ability of nano-materials with various amino acids has been characterized by UV-vis and fluorescence titrations. Results indicated that two nano-materials showed the strongest binding ability for homocysteine among twenty normal kinds of amino acids (alanine, valine, leucine, isoleucine, methionine, aspartic acid, glutamic acid, arginine, glycine, serine, threonine, asparagine, phenylalanine, histidine, tryptophan, proline, lysine, glutamine, tyrosine and homocysteine). The reason for the high sensitivity for homocysteine was that two nano-materials containing an aldehyde group reacted with SH in homocysteine and afforded very stable thiazolidine derivatives. Theoretical investigation further illustrated the possible binding mode in host-guest interaction and the roles of molecular frontier orbitals in molecular interplay. Thus, the two nano-materials can be used as optical sensors for the detection of homocysteine. PMID:24656358

  20. Evaluation of oxygen pressurized microwave-assisted digestion of botanical materials using diluted nitric acid.

    PubMed

    Bizzi, Cezar Augusto; Barin, Juliano Smanioto; Müller, Edson Irineu; Schmidt, Lucas; Nóbrega, Joaquim A; Flores, Erico Marlon Moraes

    2011-02-15

    The feasibility of diluted nitric acid solutions for microwave-assisted decomposition of botanical samples in closed vessels was evaluated. Oxygen pressurized atmosphere was used to improve the digestion efficiency and Al, Ca, K, Fe, Mg and Na were determined in digests by inductively coupled plasma optical emission spectrometry (ICP OES). Efficiency of digestion was evaluated taking into account the residual carbon content (RCC) and residual acidity in digests. Samples were digested using nitric acid solutions (2, 3, 7, and 14 mol L(-1) HNO(3)) and the effect of gas phase composition inside the reaction vessels by purging the vessel with Ar (inert atmosphere, 1 bar), air (20% of oxygen, 1 bar) and pure O(2) (100% of oxygen, 1 bar) was evaluated. The influence of oxygen pressure was studied using pressures of 5, 10, 15 and 20 bar. It was demonstrated that a diluted nitric acid solution as low as 3 mol L(-1) was suitable for an efficient digestion of sample masses up to 500 mg of botanical samples using 5 bar of oxygen pressure. The residual acidities in final digests were lower than 45% in relation to the initial amount of acid used for digestion (equivalent to 1.3 mol L(-1) HNO(3)). The accuracy of the proposed procedure was evaluated using certified reference materials of olive leaves, apple leaves, peach leaves and pine needles. Using the optimized conditions for sample digestion, the results obtained were in agreement with certified values. The limit of quantification was improved up to a factor of 14.5 times for the analytes evaluated. In addition, the proposed procedure was in agreement with the recommendations of the green chemistry once it was possible to obtain relatively high digestion efficiency (RCC<5%) using only diluted HNO(3), which is important to minimize the generation of laboratory residues. PMID:21238716

  1. Evaporation of Sessile Droplets Laden with Particles and Insoluble Surfactants.

    PubMed

    Karapetsas, George; Chandra Sahu, Kirti; Matar, Omar K

    2016-07-12

    We consider the flow dynamics of a thin evaporating droplet in the presence of an insoluble surfactant and noninteracting particles in the bulk. On the basis of lubrication theory, we derive a set of evolution equations for the film height, the interfacial surfactant, and bulk particle concentrations, taking into account the dependence of liquid viscosity on the local particle concentration. An important ingredient of our model is that it takes into account the fact that the surfactant adsorbed at the interface hinders evaporation. We perform a parametric study to investigate how the presence of surfactants affects the evaporation process as well as the flow dynamics with and without the presence of particles in the bulk. Our numerical calculations show that the droplet lifetime is affected significantly by the balance between the ability of the surfactant to enhance spreading, suppressing the effect of thermal Marangoni stresses-induced motion, and to hinder the evaporation flux through the reduction of the effective interfacial area of evaporation, which tend to accelerate and decelerate the evaporation process, respectively. For particle-laden droplets and in the case of dilute solutions, the droplet lifetime is found to be weakly dependent on the initial particle concentration. We also show that the particle deposition patterns are influenced strongly by the direct effect of the surfactant on the evaporative flux; in certain cases, the "coffee-stain" effect is enhanced significantly. A discussion of the delicate interplay between the effects of capillary pressure and solutal and thermal Marangoni stresses, which drive the liquid flow inside of the evaporating droplet giving rise to the observed results, is provided herein. PMID:27300638

  2. Physiochemical characterization of insoluble residues in California Sierra Nevada snow

    NASA Astrophysics Data System (ADS)

    Creamean, Jessie; Axson, Jessica; Bondy, Amy; Craig, Rebecca; May, Nathaniel; Shen, Hongru; Weber, Michael; Warner, Katy; Pratt, Kerri; Ault, Andrew

    2015-04-01

    The effects atmospheric aerosols have on cloud particle formation are dependent on both the aerosol physical and chemical characteristics. For instance, larger, irregular-shaped mineral dusts efficiently form cloud ice crystals, enhancing precipitation, whereas small, spherical pollution aerosols have the potential to form small cloud droplets that delay the autoconversion of cloudwater to precipitation. Thus, it is important to understand the physiochemical properties and sources of aerosols that influence cloud and precipitation formation. We present an in-depth analysis of the size, chemistry, and sources of soluble and insoluble residues found in snow collected at three locations in the California Sierra Nevada Mountains during the 2012/2013 winter season. For all sites, February snow samples contained high concentrations of regional pollutants such as ammonium nitrate and biomass burning species, while March snow samples were influenced by mineral dust. The snow at the lower elevation sites in closer proximity to the Central Valley of California were heavily influenced by agricultural and industrial emissions, whereas the highest elevation site was exposed to a mixture of Central Valley pollutants in addition to long-range transported dust from Asia and Africa. Further, air masses likely containing transported dust typically traveled over cloud top heights at the low elevation sites, but were incorporated into the cold (-28°C, on average) cloud tops more often at the highest elevation site, particularly in March, which we hypothesize led to enhanced ice crystal formation and thus the observation of dust in the snow collected at the ground. Overall, understanding the spatial and temporal dependence of aerosol sources is important for remote mountainous regions such as the Sierra Nevada where snowpack provides a steady, vital supply of water.

  3. Proteome analysis of the triton-insoluble erythrocyte membrane skeleton.

    PubMed

    Basu, Avik; Harper, Sandra; Pesciotta, Esther N; Speicher, Kaye D; Chakrabarti, Abhijit; Speicher, David W

    2015-10-14

    Erythrocyte shape and membrane integrity is imparted by the membrane skeleton, which can be isolated as a Triton X-100 insoluble structure that retains the biconcave shape of intact erythrocytes, indicating isolation of essentially intact membrane skeletons. These erythrocyte "Triton Skeletons" have been studied morphologically and biochemically, but unbiased proteome analysis of this substructure of the membrane has not been reported. In this study, different extraction buffers and in-depth proteome analyses were used to more fully define the protein composition of this functionally critical macromolecular complex. As expected, the major, well-characterized membrane skeleton proteins and their associated membrane anchors were recovered in good yield. But surprisingly, a substantial number of additional proteins that are not considered in erythrocyte membrane skeleton models were recovered in high yields, including myosin-9, lipid raft proteins (stomatin, flotillin1 and 2), multiple chaperone proteins (HSPs, protein disulfide isomerase and calnexin), and several other proteins. These results show that the membrane skeleton is substantially more complex than previous biochemical studies indicated, and it apparently has localized regions with unique protein compositions and functions. This comprehensive catalog of the membrane skeleton should lead to new insights into erythrocyte membrane biology and pathogenic mutations that perturb membrane stability. Biological significance Current models of erythrocyte membranes describe fairly simple homogenous structures that are incomplete. Proteome analysis of the erythrocyte membrane skeleton shows that it is quite complex and includes a substantial number of proteins whose roles and locations in the membrane are not well defined. Further elucidation of interactions involving these proteins and definition of microdomains in the membrane that contain these proteins should yield novel insights into how the membrane skeleton

  4. Insoluble nonstarch polysaccharides in diets for weaned piglets.

    PubMed

    Gerritsen, R; van der Aar, P; Molist, F

    2012-12-01

    To examine the effect of inclusion insoluble nonstarch polysaccharides (iNSP) in weaned diets on postweaning piglet performance, intestinal activity, and microbial composition 2 experiments were designed. In Exp. 1, 180 piglets were weaned at 28 d of age and divided over 3 treatments: positive control (PC; highly digestible protein), negative control (NC; standard cereal-based diet), and an experimental diet {iNSP; standard + 15% iNSP [wheat straw and oat (Avena sativa) hull]}. Diets were fed during 14 d after weaning. The ADFI, ADG, and G:F were determined. The inclusion of iNSP increased (P < 0.001) ADFI and G:F during days 0 to 14 after weaning and increased the ADG (P = 0.008) during days 0 to 7 after weaning compared with the NC diet. In Exp. 2, 36 piglets were fed the same diets as in Exp. 1. On days 5 and 14 after weaning, 18 piglets were euthanized to determine enzyme activity, intestinal morphology, and microbial population in the ileum and colon and organ weight. The iNSP diet reduced the concentration of Escherichia coli bacteria in the ileum (P = 0.021) and in the colon (P = 0.002) digesta and tended to increase (P = 0.060) the amylase activity. The iNSP diet stimulated the physical adaptation of the gastrointestinal tract because stomach weight as percentage of BW was heavier (P = 0.004) than for the NC diet. In conclusion, the consumption of diets with higher iNSP content in the early weaning period affects the microbial colonization without reducing enzyme activity or animal performance compared with a standard weaned pig diet. PMID:23365366

  5. Method for acid oxidation of radioactive, hazardous, and mixed organic waste materials

    DOEpatents

    Pierce, Robert A.; Smith, James R.; Ramsey, William G.; Cicero-Herman, Connie A.; Bickford, Dennis F.

    1999-01-01

    The present invention is directed to a process for reducing the volume of low level radioactive and mixed waste to enable the waste to be more economically stored in a suitable repository, and for placing the waste into a form suitable for permanent disposal. The invention involves a process for preparing radioactive, hazardous, or mixed waste for storage by contacting the waste starting material containing at least one organic carbon-containing compound and at least one radioactive or hazardous waste component with nitric acid and phosphoric acid simultaneously at a contacting temperature in the range of about 140.degree. C. to about 210 .degree. C. for a period of time sufficient to oxidize at least a portion of the organic carbon-containing compound to gaseous products, thereby producing a residual concentrated waste product containing substantially all of said radioactive or inorganic hazardous waste component; and immobilizing the residual concentrated waste product in a solid phosphate-based ceramic or glass form.

  6. Method for acid oxidation of radioactive, hazardous, and mixed organic waste materials

    SciTech Connect

    Pierce, R.A.; Smith, J.R.; Ramsey, W.G.; Cicero-Herman, C.A.; Bickford, D.F.

    1999-09-28

    The present invention is directed to a process for reducing the volume of low level radioactive and mixed waste to enable the waste to be more economically stored in a suitable repository, and for placing the waste into a form suitable for permanent disposal. The invention involves a process for preparing radioactive, hazardous, or mixed waste for storage by contacting the waste starting material containing at least one organic carbon-containing compound and at least one radioactive or hazardous waste component with nitric acid and phosphoric acid simultaneously at a contacting temperature in the range of about 140 C to about 210 C for a period of time sufficient to oxidize at least a portion of the organic carbon-containing compound to gaseous products, thereby producing a residual concentrated waste product containing substantially all of said radioactive or inorganic hazardous waste component; and immobilizing the residual concentrated waste product in a solid phosphate-based ceramic or glass form.

  7. Acid and enzymatic hydrolysis of pretreated cellulosic materials as an analytical tool

    SciTech Connect

    Ladisch, C.M.; Chiasson, C.M.; Tsao, G.T.

    1982-07-01

    A rapid and accurate procedure for the quantitative analysis of cellulose in textiles based on acid and enzymatic hydrolysis was investigated. Total hydrolysis was achieved by a two-step procedure: the cellulose in the sample was first dissolved in cadoxen and then reprecipitated. The material, thus pretreated, was then hydrolyzed with acid or enzyme catalytic agents. Hydrolysis products were detected and quantified by colorimetric, enzymic, and liquid chromatographic methods of analysis. Samples examined included cotton, rayon, Avicel, CF-11, and cotton/polyester blends. The specificity of the enzyme hydrolysis method allowed analysis of raw cotton without prior purification. Results of the analyses were compared to those obtained by existing methods of analysis.

  8. Spectrophotometric determination of deacetylation degree of chitinous materials dissolved in phosphoric acid.

    PubMed

    Hsiao, Hsien-Yi; Tsai, Chih-Cheng; Chen, Suming; Hsieh, Bo-Chuan; Chen, Richie L C

    2004-10-20

    A simple spectrophotometric method is proposed for determining deacetylation degrees (DD) of chitinous materials using phosphoric acid as the UV-transparent solvent system. Calibrating by the extinction coefficients (A(210)) of D-glucosamine and N-acetyl-D-glucosamine, DD values (24-88%) were computed numerically. The results correlated well (R(2) = 0.9805, n = 50) with those obtained by solid-state (13)C NMR. Comparison of the results obtained by the proposed UV method and solid-state (13)C NMR. PMID:15490434

  9. Volatile tritiated organic acids in stack effluents and in air surrounding contaminated materials

    SciTech Connect

    Belot, Y.; Camus, H.; Marini, T.; Raviart, S. )

    1993-06-01

    A small fraction of the tritium released into the atmosphere from tritium-handling or solid waste storage facilities was shown to be in the form of volatile organic acids. The same compounds were also found, but at a much higher proportion, in the tritium evolved at room temperature from highly contaminated materials placed under air atmospheres. This might be due to the oxidation and labeling of hydrocarbon(s) by mechanisms that are presumably of a radiolytic nature. The new forms could have an impact on operational requirements and waste management strategies within a tritium facility and a fusion reactor hall. Further data are needed to assess the related doses.

  10. ACIDIC DEPOSITION AND THE CORROSION AND DETERIORATION OF MATERIALS IN THE ATMOSPHERE: A BIBLIOGRAPHY, 1880-1982

    EPA Science Inventory

    The bibliography contains more than 1300 article citations and abstracts on the effects of acidic deposition, air pollutants, and biological and meteorological factors on the corrosion and deterioration of materials in the atmosphere. The listing includes citations for the years ...

  11. Molecular organization of a water-insoluble iridium(III) complex in mixed monolayers.

    PubMed

    Giner-Casares, Juan J; Pérez-Morales, Marta; Bolink, Henk J; Muñoz, Eulogia; de Miguel, Gustavo; Martín-Romero, María T; Camacho, Luis

    2007-11-01

    In this work, organized mixed monolayers containing a cationic water-insoluble iridium(III) complex, Ir-dye, [Ir(ppy)(2)(tmphen)]PF(6), (tmphen = 3,4,7,8-tetramethyl-1,10-phenanthroline, and ppy = 2-phenylpyridine), and an anionic lipid matrix, DMPA, dimyristoyl-phosphatidic acid, with different molar proportions, were formed by the co-spreading method at the air-water interface. The presence of the dye at the interface, as well as the molecular organization of the mixed films, is deduced from surface techniques such as pi-A isotherms, Brewster angle microscopy (BAM) and reflection spectroscopy. The results obtained remark the formation of an equimolar mixed film, Ir-dye/DMPA = 1:1. BAM images reveal a whole homogeneous monolayer, with gradually increasing reflectivity along the compression process up to reaching the collapse of this equimolecular monolayer at pi approximately equal to 37 mNm(-1). Increasing the molar ratio of DMPA in the mixture, the excess of lipid molecules organizes themselves forming dark flower-like domains of pure DMPA at high surface pressures, coexisting with the mixed Ir-dye/DMPA = 1:1 monolayer. On the other hand, unstable mixed monolayers are obtained by using an initial dye surface concentration higher than the equimolecular one. These mixed Langmuir monolayers have been successfully transferred onto solid substrates by the LB (Langmuir-Blodgett) technique. PMID:17618641

  12. Folding and Purification of Insoluble (Inclusion Body) Proteins from Escherichia coli.

    PubMed

    Wingfield, Paul T; Palmer, Ira; Liang, Shu-Mei

    2014-01-01

    Heterologous expression of recombinant proteins in E. coli often results in the formation of insoluble and inactive protein aggregates, commonly referred to as inclusion bodies. To obtain the native (i.e., correctly folded) and hence active form of the protein from such aggregates, four steps are usually followed: (1) the cells are lysed, (2) the cell wall and outer membrane components are removed, (3) the aggregates are solubilized (or extracted) with strong protein denaturants, and (4) the solubilized, denatured proteins are folded with concomitant oxidation of reduced cysteine residues into the correct disulfide bonds to obtain the native protein. This unit features three different approaches to the final step of protein folding and purification. In the first, guanidine·HCl is used as the denaturant, after which the solubilized protein is folded (before purification) in an "oxido-shuffling" buffer system to increase the rate of protein oxidation. In the second, acetic acid is used to solubilize the protein, which is then partially purified by gel filtration before folding; the protein is then folded and oxidized by simple dialysis against water. Thirdly, folding and purification of a fusion protein using metal-chelate affinity chromatography are described. PMID:25367010

  13. Mechanisms of cholesterol-lowering effects of dietary insoluble fibres: relationships with intestinal and hepatic cholesterol parameters.

    PubMed

    van Bennekum, Ariëtte M; Nguyen, David V; Schulthess, Georg; Hauser, Helmut; Phillips, Michael C

    2005-09-01

    Fibres with a range of abilities to perturb cholesterol homeostasis were used to investigate how the serum cholesterol-lowering effects of insoluble dietary fibres are related to parameters of intestinal cholesterol absorption and hepatic cholesterol homeostasis in mice. Cholestyramine, chitosan and cellulose were used as examples of fibres with high, intermediate and low bile acid-binding capacities, respectively. The serum cholesterol levels in a control group of mice fed a high fat/high cholesterol (HFHC) diet for 3 weeks increased about 2-fold to 4.3 mm and inclusion of any of these fibres at 7.5 % of the diet prevented this increase from occurring. In addition, the amount of cholesterol accumulated in hepatic stores due to the HFHC diet was reduced by treatment with these fibres. The three kinds of fibres showed similar hypocholesterolaemic activity; however, cholesterol depletion of liver tissue was greatest with cholestyramine. The mechanisms underlying the cholesterol-lowering effect of cholestyramine were (1) decreased cholesterol (food) intake, (2) decreased cholesterol absorption efficiency, and (3) increased faecal bile acid and cholesterol excretion. The latter effects can be attributed to the high bile acid-binding capacity of cholestyramine. In contrast, incorporation of chitosan or cellulose in the diet reduced cholesterol (food) intake, but did not affect either intestinal cholesterol absorption or faecal sterol output. The present study provides strong evidence that above all satiation and satiety effects underlie the cholesterol-lowering properties of insoluble dietary fibres with moderate or low bile acid-binding capabilities. PMID:16176602

  14. Removal of Basic Violet 14 from aqueous solution using sulphuric acid activated materials.

    PubMed

    Suresh, S

    2016-01-01

    In this study the adsorption of Basic Violet, 14 from aqueous solution onto sulphuric acid activated materials prepared from Calophyllum inophyllum (CS) and Theobroma cacao (TS) shells were investigated. The experimental data were analysed by Langmuir, Freundlich and Temkin isotherm models. The results showed that CS has a superior adsorption capacity compared to the TS. The adsorption capacity was found to be 1416.43 mg/g for CS and 980.39 mg/g for TS. The kinetic data results at different concentrations were analysed using pseudo first-order and pseudo-second order model. Boyd plot indicates that the dye adsorption onto CS and TS is controlled by film diffusion. The adsorbents were characterised by scanning electron microscopy. The materials used in this study were economical waste products and hence can be an attractive alternative to costlier adsorbents for dye removal in industrial wastewater treatment processes. PMID:27330899

  15. Acid Functionalized Mesoporous Ordered Materials for the Production of 5-Hydroxymethyfurfural from Carbohydrates

    NASA Astrophysics Data System (ADS)

    Crisci, Anthony J.

    Solid acid catalysts were designed for the conversion of fructose to 5-hydroxymethylfurfural (HMF). Some of the catalysts incorporate thioether groups to promote the tautomerization of fructose to its furanose form, as well as sulfonic acid groups to catalyze its dehydration. A bifunctional silane, 3-((3-(trimethoxysilyl)propyl)thio)propane-1-sulfonic acid (TESAS), was designed for incorporation into SBA-15-type silica by co-condensation. To achieve mesopore ordering in the functionalized silica, the standard SBA-15 synthetic protocol was modified, resulting in well-formed hexagonal particles. Functional groups incorporated into mesoporous silica by co-condensation are more robust under the reaction conditions than those grafted onto a non-porous silica. In a variation, the thioether group of TESAS was oxidized by H2O 2 to the sulfone during the synthesis of the modified SBA-15. The materials were tested in batch reactors and compared in the selective dehydration of fructose to 5-hydroxymethylfurfural (HMF). Compared to benchmark catalysts, the thioether-containing TESAS-SBA-15 showed the highest activity in the dehydration of aqueous fructose, as well as the highest selectivity towards HMF (71 % at 84 % conversion). In addition, the stability of several supported acid catalysts was evaluated in tubular reactors designed to produce 5-hydroxymethylfurfural (HMF) continuously. The reactors, packed with the solid catalysts, were operated at 403 K for extended periods, up to 180 h. The behaviors of three propylsulfonic acid-functionalized, ordered porous silicas (one inorganic SBA-15-type silica, and two ethane-bridged SBA-15-type organosilicas) were compared with that of a propylsulfonic acid-modified, non-ordered porous silica. The HMF selectivity of the catalysts with ordered pore structures ranged from 60 to 75 %, while the selectivity of the non-ordered catalyst peaked at 20 %. The latter was also the least stable, deactivating with a first-order rate constant of

  16. Variability of humic acid properties depending on their precursor material: a study of peat profiles

    NASA Astrophysics Data System (ADS)

    Klavins, Maris; Purmalis, Oskars

    2015-04-01

    and impact of environmental conditions on the surfactant properties of humic matter. Amongst the main objectives of the study was the identification of the dependence of the humic acid properties on the composition of original living matter in the peat, especially considering high variability of peat composition in the studied bogs. Despite some correlation between peat botanical composition and properties exist, in general the similarities are much more expressed, thus indicating the significance of microbial decay processes on the properties of humic material. Acknowledgement: Support from a project ResProd

  17. Reaction Products of Unsaturated Polycarboxylic Acids and Sodium Hypophosphite for Improved Flame Resistance of Cotton-Containing Materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reaction products of unsaturated polycarboxylic acids and sodium hypophosite were found to improve flame resistance of cellulosic materials as determined by the 45 degree flammability test for apparel textiles. The most effective product was that from the reaction of maleic acid with sodium hypopho...

  18. 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. PMID:24315947

  19. Luminescence behavior of terbium sulphosalicylic acid complexes in sol-gel derived host materials

    SciTech Connect

    Fan, X.; Wang, M.; Wang, Z.; Hong, Z.

    1997-08-01

    The formation and luminescence behavior of terbium sulphosalicylic acid (TbSSA) complexes in sol-gel derived host materials have been investigated. The 5-sulphosalicylic acid (H{sub 3}SSA) was dissolved in ethanol in advance, and then the TbCl{sub 3} and ethanol containing H{sub 3}SSA were introduced into the initial precursor sol, respectively. The resulting sol exhibits intramolecular energy transfer from the coordinated sulphosalicylic acid to the terbium ion. The TbSSA complex has formed in the TbCl{sub 3} and H{sub 3}SSA codoped sol. The complexes were found to have notably higher fluorescence intensities than TbCl{sub 3} in both the sol and the gel. In the sol, the concentration quenching was a diffusion-controlled process due to aggregation and effective collision between molecules and the fluorescence was decreased with increase of H{sub 3}SSA concentration. On the other hand, the molecules in the gel were isolated in the pores of the silica network. The fluorescence intensities of TbSSA in the gel were increased with the increase of concentration ratio of H{sub 3}SSA/TbCl{sub 3}. Maximum fluorescence intensity was obtained at H{sub 3}SSA/TbCl{sub 3} = 2.

  20. Improvement of β-TCP/PLLA biodegradable material by surface modification with stearic acid.

    PubMed

    Ma, Fengcang; Chen, Sai; Liu, Ping; Geng, Fang; Li, Wei; Liu, Xinkuan; He, Daihua; Pan, Deng

    2016-05-01

    Poly-l-lactide (PLLA) is a biodegradable polymer and used widely. Incorporation of beta tricalcium phosphate (β-TCP) into PLLA can enhance its osteoinductive properties. But the interfacial layer between β-TCP particles with PLLA matrix is easy to be destroyed due to inferior interfacial compatibility of the organic/inorganic material. In this work, a method of β-TCP surface modification with stearic acid was investigated to improve the β-TCP/PLLA biomaterial. The effects of surface modification on the β-TCP were investigated by FTIR, XPS, TGA and CA. It was found that the stearic acid reacted with β-TCP and oxhydryl was formed during the surface modification. Hydrophilicity of untreated or modified β-TCP/PLLA composite was increased by the addition of 10wt.% β-TCP, but it decreased as the addition amount increased from 10wt.% to 20wt.%. Two models were suggested to describe the effect of β-TCP concentration on CA of the composites. Mechanical properties of β-TCP/PLLA composites were tested by bending and tensile tests. Fractures of the composites after mechanical test were observed by SEM. It was found that surface modification with stearic acid improved bending and tensile strengths of the β-TCP/PLLA composites obviously. The SEM results indicated that surface modification decreased the probability of interface debonding between fillers and matrix under load. PMID:26952440

  1. Chemical modeling of acid-base properties of soluble biopolymers derived from municipal waste treatment materials.

    PubMed

    Tabasso, Silvia; Berto, Silvia; Rosato, Roberta; Marinos, Janeth Alicia Tafur; Ginepro, Marco; Zelano, Vincenzo; Daniele, Pier Giuseppe; Montoneri, Enzo

    2015-01-01

    This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials. PMID:25658795

  2. Determination of perfluorinated alkyl acid concentrations in biological standard reference materials.

    PubMed

    Reiner, Jessica L; O'Connell, Steven G; Butt, Craig M; Mabury, Scott A; Small, Jeff M; De Silva, Amila O; Muir, Derek C G; Delinsky, Amy D; Strynar, Mark J; Lindstrom, Andrew B; Reagen, William K; Malinsky, Michelle; Schäfer, Sandra; Kwadijk, Christiaan J A F; Schantz, Michele M; Keller, Jennifer M

    2012-11-01

    Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned for legacy pollutants. These SRMs can also serve as test materials for method development, method validation, and measurement for contaminants of emerging concern. Because inter-laboratory comparison studies have revealed substantial variability of measurements of perfluoroalkyl acids (PFAAs), future analytical measurements will benefit from determination of consensus values for PFAAs in SRMs to provide a means to demonstrate method-specific performance. To that end, NIST, in collaboration with other groups, has been measuring concentrations of PFAAs in a variety of SRMs. Here we report levels of PFAAs and perfluorooctane sulfonamide (PFOSA) determined in four biological SRMs: fish tissue (SRM 1946 Lake Superior Fish Tissue, SRM 1947 Lake Michigan Fish Tissue), bovine liver (SRM 1577c), and mussel tissue (SRM 2974a). We also report concentrations for three in-house quality-control materials: beluga whale liver, pygmy sperm whale liver, and white-sided dolphin liver. Measurements in SRMs show an array of PFAAs, with perfluorooctane sulfonate (PFOS) being the most frequently detected. Reference and information values are reported for PFAAs measured in these biological SRMs. PMID:22476786

  3. Chemical Modeling of Acid-Base Properties of Soluble Biopolymers Derived from Municipal Waste Treatment Materials

    PubMed Central

    Tabasso, Silvia; Berto, Silvia; Rosato, Roberta; Tafur Marinos, Janeth Alicia; Ginepro, Marco; Zelano, Vincenzo; Daniele, Pier Giuseppe; Montoneri, Enzo

    2015-01-01

    This work reports a study of the proton-binding capacity of biopolymers obtained from different materials supplied by a municipal biowaste treatment plant located in Northern Italy. One material was the anaerobic fermentation digestate of the urban wastes organic humid fraction. The others were the compost of home and public gardening residues and the compost of the mix of the above residues, digestate and sewage sludge. These materials were hydrolyzed under alkaline conditions to yield the biopolymers by saponification. The biopolymers were characterized by 13C NMR spectroscopy, elemental analysis and potentiometric titration. The titration data were elaborated to attain chemical models for interpretation of the proton-binding capacity of the biopolymers obtaining the acidic sites concentrations and their protonation constants. The results obtained with the models and by NMR spectroscopy were elaborated together in order to better characterize the nature of the macromolecules. The chemical nature of the biopolymers was found dependent upon the nature of the sourcing materials. PMID:25658795

  4. Preparation and Electrochemical Performance of Hybrid Materials Containing Heteropoly Acid with Dawson Structure and Polymers

    NASA Astrophysics Data System (ADS)

    Tong, Xia; Wu, Wen; Zhou, Shengming; Wu, Qingyin; Cao, Fahe; Yaroslavtsev, A. B.

    2012-11-01

    Highly proton-conducting hybrid materials (P2W17V/PEG and P2W17V/PEG/SiO2) were prepared by heptadecatungstovanadodiphosphoric heteropoly acid with Dawson structure (P2W17V, 90 wt.%), polyethylene glycol (PEG, 10 wt.% and 5 wt.%) and silica gel (SiO2, 0 wt.% and 5 wt.%). The products were characterized by the infrared (IR) spectrum, X-ray powder diffraction (XRD) analysis and electrochemical impedance spectrum (EIS). The result reveals that their conductivity values are 1.02 × 10-2 and 2.58 × 10-2S ṡ cm-1 at room temperature (26°C) and 75% relative humidity (RH), respectively. Their conductivities increase with higher temperature and these activation energies of proton conduction are 9.51 and 14.95 kJṡmol-1, which are lower than that of pure heteropoly acid (32.23 kJṡmol-1). These mechanisms of proton conduction for these two materials are Grotthuss mechanism.

  5. On the future development of optimally-sized lipid-insoluble systemic therapies for CNS solid tumors and other neuropathologies.

    PubMed

    Sarin, Hemant

    2010-11-01

    It remains a challenge to deliver effective concentrations of therapeutics into CNS pathologies, which is primarily due to the fact that current and investigational CNS therapeutics are suboptimally-sized to accumulate to effective concentrations in individual diseased CNS tissue cells. The blood-CNS barrier of blood capillary microvasculature within neuropathologic tissues is known to be permeable to lipid-insoluble macromolecules in a wide-spectrum of neuropathologies. In the case of CNS solid tumor tissue blood capillaries, the physiological upper limit of pore size to the transcapillary passage of spherical lipid-insoluble macromolecules is approximately 12 nanometers, and systemically administered imageable dendrimer nanoparticles within the 7 to 10 nanometer size range accumulate to therapeutic concentrations in solid tumors since this size range of particles maintain peak blood concentrations for several hours. In preliminary pre-clinical studies, it has recently been shown that one intravenous dose of small molecule chemotherapy-conjugated imageable dendrimer nanoparticles within the 7 to 10 nanometer size range, with doxorubicin bound to the particle exterior via acid-labile covalent linkages, is effective at regressing orthotopic rodent malignant gliomas. Although it is foreseeable that such drug-conjugated imageable nanoparticles within the 7 to 10 nanometer size range will be effective theranostic agents for the concurrent treatment (i.e. neutron capture therapy) and imaging (i.e. magnetic resonance) of solid tumor disease, the issue of maintaining a neutralized particle exterior following the attachment of cationic drugs will need to be addressed to eliminate cationic charge-mediated nanoparticle toxicity to blood capillary walls. In this review, the ultrastructural basis for blood capillary microvascular permeability to lipid-insoluble macromolecules is discussed, and the importance of delineating the precise physiologic upper limits of pore size in

  6. Non-extractable procyanidins and lignin are important factors in the bile acid binding and radical scavenging properties of cell wall material in some fruits.

    PubMed

    Hamauzu, Yasunori; Mizuno, Yukari

    2011-03-01

    The cell wall components and the food functions of alcohol-insoluble solids (AIS) of Chinese quince, quince, hawthorn, apple, pear and blueberry fruits were analyzed. Chinese quince contained characteristically high contents of cellulose, lignin, and non-extractable procyanidins (NEPCs). On the other hand, the quince AIS contained the highest proportion of NEPCs, the highest mean degree of polymerization (mDP), the strongest radical scavenging activity, and strong bile acid binding activity. In fruit AIS, the lignin and NEPC contents both showed positive correlations with the bile acid binding and radical scavenging activities. The value for mDP × NEPC content was a good index for the radical scavenging activity. The results suggest that highly polymerized NEPCs and lignin are important factors of cell wall components of fruits to having a high functionality, and Chinese quince and quince are interesting fruits from this view point. PMID:21243435

  7. Critical evaluation of changes in the ratio of insoluble bound to soluble phenolics on antioxidant activity of lentils during germination.

    PubMed

    Yeo, JuDong; Shahidi, Fereidoon

    2015-01-21

    A new indicator, the ratio of insoluble bound phenolics (IBPs) to soluble phenolics (SPs), is suggested as an effective means to monitor changes in the antioxidant activity of lentils during germination. This indicator may be used to monitor other process-induced changes in antioxidant potential of food phenolics in other foods. The antioxidant activity of SPs, IBPs, and total value, the sum of both free and esterified phenolics, of germinated CDC Richlea lentil variety was evaluated for 4 days. Total phenolic content (TPC), total flavonoid content (TFC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging ability were employed to record antioxidant activities. An incremental increase in IBPs was found in TPC, TFC, DPPH, and ABTS radical cation scavenging ability, whereas SPs showed a declining trend in TFC, DPPH, and ABTS, except TPC during 4 days of germination. The ratio of IBPs to SPs increased using most methods, and this may be possibly due to the changes of phenolic compound formation from soluble into insoluble bound form during germination process. The ratio can be used as a novel method for monitoring process-induced changes in the antioxidant activity of foods. PMID:25560637

  8. The effects of hyaluronic acid incorporated as a wetting agent on lysozyme denaturation in model contact lens materials.

    PubMed

    Weeks, Andrea; Boone, Adrienne; Luensmann, Doerte; Jones, Lyndon; Sheardown, Heather

    2013-09-01

    Conventional and silicone hydrogels as models for contact lenses were prepared to determine the effect of the presence of hyaluronic acid on lysozyme sorption and denaturation. Hyaluronic acid was loaded into poly(2-hydroxyethyl methacrylate) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) hydrogels, which served as models for conventional and silicone hydrogel contact lens materials. The hyaluronic acid was cross-linked using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide in the presence of dendrimers. Active lysozyme was quantified using a Micrococcus lysodeikticus assay while total lysozyme was determined using 125-I radiolabeled protein. To examine the location of hyaluronic acid in the gels, 6-aminofluorescein labeled hyaluronic acid was incorporated into the gels using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide chemistry and the gels were examined using confocal laser scanning microscopy. Hyaluronic acid incorporation significantly reduced lysozyme sorption in poly(2-hydroxyethyl methacrylate) (p < 0.00001) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) (p < 0.001) hydrogels, with the modified materials sorbing only 20% and 16% that of the control, respectively. More importantly, hyaluronic acid also decreased lysozyme denaturation in poly(2-hydroxyethyl methacrylate) (p < 0.005) and poly(2-hydroxyethyl methacrylate)/TRIS--methacryloxypropyltris (trimethylsiloxy silane) (p < 0.02) hydrogels. The confocal laser scanning microscopy results showed that the hyaluronic acid distribution was dependent on both the material type and the molecular weight of hyaluronic acid. This study demonstrates that hyaluronic acid incorporated as a wetting agent has the potential to reduce lysozyme sorption and denaturation in contact lens applications. The distribution of hyaluronic acid within hydrogels appears to affect denaturation, with more surface mobile, lower

  9. Natural sedimentation of insoluble particles during directional solidification of upgraded metallurgical-grade silicon

    NASA Astrophysics Data System (ADS)

    Gan, C. H.; Xiong, H. P.; Fang, M.; Qiu, S.; Xing, P. F.; Luo, X. T.

    2016-04-01

    Upgraded metallurgical-grade silicon is used to cast an ingot by directional solidification. Black shadows are randomly distributed in the ingot, and the shadows are caused by natural sedimentation of insoluble particles. The insoluble particles mainly consist of SiC and Si3N4. SiC and Si3N4 exist as foreign particles and mainly sedimentate at the bottom of the ingot, not generating during directional solidification. Melt convection performs an important role in the sedimentation, resulting in the insoluble particles in the ingot center more than the nearby. Interestingly, since SiC and Si3N4 will not be the recombination center of the minority carrier, the insoluble particles do not have a significant influence on the minority carrier lifetime. In particular, the sedimentation is discussed according to the thermodynamics and kinetics in detail.

  10. Tunable macromolecular-based materials for the adsorption of perfluorooctanoic and octanoic acid anions.

    PubMed

    Karoyo, Abdalla H; Wilson, Lee D

    2013-07-15

    The sorption properties of tunable urethane-based copolymer materials containing β-cyclodextrin (β-CD) were evaluated with perfluorooctanoic acid (PFOA) and octanoic acid (OA) anions in aqueous solutions, respectively. The copolymer materials are herein referred to as macromolecular imprinted materials (MIMs) since their design strategy incorporates a porogen macromolecule (β-CD) within a cross-linked hexamethylene diisocyanate (HDI) framework. We report the tunable uptake of OA and PFOA anions from aqueous solution with variable adsorption modes, in accordance with the composition of the MIMs. The sorption results with granular activated carbon (GAC) were compared at 295 K and pH values exceeding the pKa values of each adsorbate. The BET and Sips models provided estimates of the monolayer sorption capacity (Qm) and related equilibrium sorption parameters. The Qm value for GAC with PFOA was ~1.4 mmol/g; whereas, a greater Qm value for PFOA (up to 2.6 mmol/g) was observed with the MIMs. GAC displays greater sorption capacity toward PFOA at relatively low Ce values and saturation of the monolayer occurs at Ce~0.5 mM. The MIMs/PFOA system displays monolayer completion at values of Ce~1 mM and multilayer sorption when Ce>1mM. Equilibrium sorption of PFOA onto MIMs occurs at the inclusion sites of β-CD and interstitial binding sites of the polymeric framework. Surface adsorption of the PFOA anion occurs between the PFOA carboxylate head group and dipolar interstitial domains of the cross-linker framework. The MIMs sorbents display tunable and favorable binding with PFOA and OA anions where the uptake (per mg MIMs) with PFOA was ~5-33% (5 μM-5 mM) and with OA was ~0.5-5% (1-20 mM). The overall sorptive uptake of OA and PFOA anions by the MIMs sorbents meets or exceeds those observed for GAC. PMID:23664395

  11. Acid/vanadium-containing saponite for the conversion of propene into coke: potential flame-retardant filler for nanocomposite materials.

    PubMed

    Ostinelli, Luca; Recchia, Sandro; Bisio, Chiara; Carniato, Fabio; Guidotti, Matteo; Marchese, Leonardo; Psaro, Rinaldo

    2012-10-01

    Vanadium-containing saponite samples were synthesized in a one-pot synthetic procedure with the aim of preparing samples for potential application as fillers for polymeric composites. These vanadium-modified materials were prepared from an acid support by adopting a synthetic strategy that allowed us to introduce isolated structural V species (H/V-SAP). The physicochemical properties of these materials were investigated by XRD analysis and by DR-UV/Vis and FTIR spectroscopy of CO that was adsorbed at 100 K; these data were compared to those of a V-modified saponite material that did not contain any Brønsted acid sites (Na/V-SAP). The surface-acid properties of both samples (together with the fully acidic H-SAP material and the Na-SAP solid) were studied in the catalytic isomerization of α-pinene oxide. The V-containing solids were tested in the oxidative dehydrogenation reaction of propene to evaluate their potential use as flame-retardant fillers for polymer composites. The effect of tuning the presence of Lewis/Brønsted acid sites was carefully studied. The V-containing saponite sample that contained a marked presence of Brønsted acid sites showed the most interesting performance in the oxidative dehydrogenation (ODH) reactions because they produced coke, even at 773 K. The catalytic data presented herein indicate that the H/V-SAP material is potentially active as a flame-retardant filler. PMID:22791515

  12. Self-Assembly of Charged Amphiphilic Diblock Copolymers with Insoluble Blocks of Decreasing Hydrophobicity: From Kinetically Frozen Colloids to Macrosurfactants

    SciTech Connect

    M Jacquin; P Muller; H Cottet; O Theodoly

    2011-12-31

    We have investigated the self-assembly properties in aqueous solution of amphiphilic diblock copolymers with insoluble blocks of different hydrophobicity and demonstrated that the condition to obtain dynamic micelles is to design samples with insoluble blocks of low enough hydrophobicity. We focus here on results with new water-soluble amphiphilic diblock copolymers poly(diethyleneglycol ethylether acrylate)-b-poly(acrylic acid), or PDEGA-b-PAA. The physical characteristics of PDEGA-b-PAA micelles at high ionization have been determined by small angle neutron scattering (SANS). We show that PDEGA-b-PAA samples form micelles at thermodynamic equilibrium. The critical micelle concentrations (CMCs) decrease strongly with ionic strength and temperature due to a solvent quality decrease for, respectively, the corona and the core. This behavior of reversible aggregation is remarkable as compared to the behavior of kinetically frozen aggregation that has been widely observed with samples of similar architecture and different hydrophobic blocks, for example, poly(styrene)-b-poly(acrylic acid), PS-b-PAA, and poly(butyl acrylate)-b-poly(acrylic acid), PBA-b-PAA. We have measured the interfacial tension between water and the homopolymers PDEGA and PBA at, respectively, 3 and 20 mN/m at room temperature, which permits one to estimate the energy cost to extract a unimer from a micelle. The results are consistent with a micelle association that is fast for PDEGA-b-PAA and kinetically frozen PBA-b-PAA. Hence, PDEGA-b-PAA samples form a new system of synthetic charged macrosurfactant with unique properties of fast dynamic association, tunable charge, and water solubility even at temperatures and NaCl concentrations as high as 65 C and 1 M.

  13. Biology Teacher and Expert Opinions about Computer Assisted Biology Instruction Materials: A Software Entitled Nucleic Acids and Protein Synthesis

    ERIC Educational Resources Information Center

    Hasenekoglu, Ismet; Timucin, Melih

    2007-01-01

    The aim of this study is to collect and evaluate opinions of CAI experts and biology teachers about a high school level Computer Assisted Biology Instruction Material presenting computer-made modelling and simulations. It is a case study. A material covering "Nucleic Acids and Protein Synthesis" topic was developed as the "case". The goal of the…

  14. AMINO ACID COMPOSITION OF SUSPENDED PARTICLES, SEDIMENT-TRAP MATERIAL, AND BENTHIC SEDIMENT IN THE POTOMAC ESTUARY

    EPA Science Inventory

    Sediment trap deployments in estuaries provide a method for estimating the amount of organic material transported to the sediments from the euphotic zone. he amino acid composition of suspended particles, benthic sediment, and sediment-trap material collected at 2.4 m, 5.8 m, and...

  15. Water-insoluble thin films from palmitoyl hyaluronan with tunable properties.

    PubMed

    Foglarová, Marcela; Chmelař, Josef; Huerta-Angeles, Gloria; Vágnerová, Hana; Kulhánek, Jaromír; Bartoň Tománková, Kateřina; Minařík, Antonín; Velebný, Vladimír

    2016-06-25

    Hyaluronan (HA) films exhibit properties suitable for various biomedical applications, but the solubility of HA limits their use in aqueous environments. Therefore, we developed water insoluble films based on palmitoyl esters of HA (pHA). Films were prepared from pHA samples with various degrees of substitution (DS) and molecular weights and their mechanical properties and swelling were characterized. Additionally, scanning electron microscopy and atomic force microscopy were used for visualization. Despite being prepared by solution casting, the films had a very smooth surface and were homogeneous in thickness. The film properties were in accordance with the polymer DS and molecular weight, enabling to tailor them for future applications by choosing a suitable pHA material. The behavior of the films toward cells was assessed in vitro. All films were non-cytotoxic and showed no adhesion of cells. These results show that the developed films are suitable candidates for various biomedical applications such as tissue engineering or wound healing. PMID:27083794

  16. Distribution of Components in Ion Exchange Materials Taken from the K East Basin and Leaching of Ion Exchange Materials by Nitric/Hydrofluoric Acid and Nitric/Oxalic Acid

    SciTech Connect

    Delegard, C.H.; Rinehart, D.E.; Hoopes, F.V.

    1999-04-02

    Laboratory tests were performed to examine the efficacy of mixed nitric/hydrofluoric acid followed by mixed nitric/oxalic acid leach treatments to decontaminate ion exchange materials that have been found in a number of samples retrieved from K East (KE)Basin sludge. The ion exchange materials contain organic ion exchange resins and zeolite inorganic ion exchange material. Based on process records, the ion exchange resins found in the K Basins is a mixed-bed, strong acid/strong base material marketed as Purolite NRW-037. The zeolite material is Zeolon-900, a granular material composed of the mineral mordenite. Radionuclides sorbed or associated with the ion exchange material can restrict its disposal to the Environmental Restoration Disposal Facility (ERDF). The need for testing to support development of a treatment process for K Basin sludge has been described in Section 4.2 of ''Testing Strategy to Support the Development of K Basins Sludge Treatment Process'' (Flament 1998). Elutriation and washing steps are designed to remove the organic resins from the K Basin sludge. To help understand the effects of the anticipated separation steps, tests were performed with well-rinsed ion exchange (IX) material from KE Basin floor sludge (sample H-08 BEAD G) and with well-rinsed IX having small quantities of added KE canister composite sludge (sample KECOMP). Tests also were performed to determine the relative quantities of organic and inorganic IX materials present in the H-08 K Basin sludge material. Based on chemical analyses of the separated fractions, the rinsed and dry IX material H-08 BEAD G was found to contain 36 weight percent inorganic material (primarily zeolite). The as-received (unrinsed) and dried H-08 material was estimated to contain 45 weight percent inorganic material.

  17. Crystal growth, spectral, optical and thermal properties of semiorganic nonlinear optical material: Picolinic acid hydrochloride

    NASA Astrophysics Data System (ADS)

    Gowri, S.; Uma Devi, T.; Sajan, D.; Surendra Dilip, C.; Chandramohan, A.; Lawrence, N.

    2013-06-01

    The bulk single crystal of 2-picolinic acid hydrochloride (PHCL) (a semi-organic nonlinear optical material of dimensions 25 × 15 × 10 mm3) was successfully grown by slow solvent evaporation technique. The XRD results revealed the cell parameters and the centrosymmetric nature of the crystal structure. FT-IR spectral study identified the functional groups, nature of bonding and their bond strength. The UV-Vis-NIR studies recognized the optical transmittance window and the lower cut off wavelength of the PHCL crystal and thus it could be performed as a NLO material. 1H NMR and 13CNMR spectra were correlated with the XRD standard for the molecular structure reveals harmony of the materials. Thermal properties of the crystal were studied by thermo gravimetric analysis (TGA) and differential thermal analysis (DTA); the derived kinetic parameter values support the intuitive association of picolinicacid and HCl leads to the spontaneous formation of PHCL with a first order reaction. The presence of a proton and a proton acceptor groups provide the necessary stability to induce charge asymmetry in the PHCL structure. The load dependent hardness values of the crystal were measured by microhardness testing.

  18. New composite materials based on alginate and hydroxyapatite as potential carriers for ascorbic acid.

    PubMed

    Ilie, Andreia; Ghiţulică, Cristina; Andronescu, Ecaterina; Cucuruz, Andrei; Ficai, Anton

    2016-08-30

    The purpose of this article was to obtain prolonged drug release systems in which the drug (ascorbic acid) to reach intact the target area in an environment that is able to control the administration of the active component by chemical or physiological pathways. As support for drug, it was used a material based on calcium phosphate - hydroxyapatite and a natural polymer - alginate, since it is one of the most investigated composite materials for medical applications due to its positive response to biological testing: bioactivity, biocompatibility and osteoconductivity. Three composites with different ratios between alginate and hydroxyapatite were obtained: (a) Alg/HA/AA 1:1 (the mass ratio between Alg and HA being of 1:1), (b) Alg/HA/AA 1:3 (Alg:HA mass ratio of 1:3) and (c) Alg/HA/AA 3:1 (Alg:HA mass ratio of 3:1). The synthesized materials were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and to observe the drug release process, UV-vis spectroscopy. PMID:26784979

  19. Analysis of glyphosate and aminomethylphosphonic acid in water, plant materials and soil.

    PubMed

    Koskinen, William C; Marek, LeEtta J; Hall, Kathleen E

    2016-03-01

    There is a need for simple, fast, efficient and sensitive methods of analysis for glyphosate and its degradate aminomethylphosphonic acid (AMPA) in diverse matrices such as water, plant materials and soil to facilitate environmental research needed to address the continuing concerns related to increasing glyphosate use. A variety of water-based solutions have been used to extract the chemicals from different matrices. Many methods require extensive sample preparation, including derivatization and clean-up, prior to analysis by a variety of detection techniques. This review summarizes methods used during the past 15 years for analysis of glyphosate and AMPA in water, plant materials and soil. The simplest methods use aqueous extraction of glyphosate and AMPA from plant materials and soil, no derivatization, solid-phase extraction (SPE) columns for clean-up, guard columns for separation and confirmation of the analytes by mass spectrometry and quantitation using isotope-labeled internal standards. They have levels of detection (LODs) below the regulatory limits in North America. These methods are discussed in more detail in the review. © 2015 Society of Chemical Industry. PMID:26454260

  20. Elemental, isotopic, and structural changes in Tagish Lake insoluble organic matter produced by parent body processes

    NASA Astrophysics Data System (ADS)

    Alexander, C. M. O'd.; Cody, G. D.; Kebukawa, Y.; Bowden, R.; Fogel, M. L.; Kilcoyne, A. L. D.; Nittler, L. R.; Herd, C. D. K.

    2014-04-01

    Here, we present the results of a multitechnique study of the bulk properties of insoluble organic material (IOM) from the Tagish Lake meteorite, including four lithologies that have undergone different degrees of aqueous alteration. The IOM C contents of all four lithologies are very uniform and comprise about half the bulk C and N contents of the lithologies. However, the bulk IOM elemental and isotopic compositions vary significantly. In particular, there is a correlated decrease in bulk IOM H/C ratios and δD values with increasing degree of alteration—the IOM in the least altered lithology is intermediate between CM and CR IOM, while that in the more altered lithologies resembles the very aromatic IOM in mildly metamorphosed CV and CO chondrites, and heated CMs. Nuclear magnetic resonance (NMR) spectroscopy, C X-ray absorption near-edge (XANES), and Fourier transform infrared (FTIR) spectroscopy confirm and quantitate this transformation from CR-like, relatively aliphatic IOM functional group chemistry to a highly aromatic one. The transformation is almost certainly thermally driven, and probably occurred under hydrothermal conditions. The lack of a paramagnetic shift in 13C NMR spectra and 1s-σ* exciton in the C-XANES spectra, both typically seen in metamorphosed chondrites, shows that the temperatures were lower and/or the timescales were shorter than experienced by even the least metamorphosed type 3 chondrites. Two endmember models were considered to quantitatively account for the changes in IOM functional group chemistry, but the one in which the transformations involved quantitative conversion of aliphatic material to aromatic material was the more successful. It seems likely that similar processes were involved in producing the diversity of IOM compositions and functional group chemistries among CR, CM, and CI chondrites. If correct, CRs experienced the lowest temperatures, while CM and CI chondrites experienced similar more elevated temperatures

  1. Combining insoluble and soluble factors to steer stem cell fate

    NASA Astrophysics Data System (ADS)

    Dingal, P. C. Dave P.; Discher, Dennis E.

    2014-06-01

    Materials-based control of stem cell fate is beginning to be rigorously combined with traditional soluble-factor approaches to better understand the cells' behaviour and maximize their potential for therapy.

  2. Insoluble protein purification with sarkosyl: facts and precautions.

    PubMed

    Chisnall, Ben; Johnson, Courtney; Kulaberoglu, Yavuz; Chen, Yu Wai

    2014-01-01

    When eukaryotic proteins are overexpressed in Escherichia coli hosts, they often form inclusion bodies. Natively folded proteins can be extracted from inclusion bodies using mild detergents such as sarkosyl. One common problem is the sequestration of nucleic acid contaminants with the protein of interest. Here we describe methods for monitoring the presence of co-precipitated nucleic acids, and their removal. These procedures are simple to implement and can be easily adapted to a high-throughput format. While sarkosyl is a common chemical, some information such as its UV absorption spectrum and micellar size are absent in the literature or poorly referenced. We review and summarize the properties that are the most relevant to structural biology. PMID:24203332

  3. A new supporting material for fascia grafting during myringoplasty: polyglycolic acid sheets.

    PubMed

    Yamanaka, Toshiaki; Sawai, Yachiyo; Hosoi, Hiroshi

    2013-08-01

    We used polyglycolic acid (PGA) sheets, a reinforcing material, as supporting devices for securing the fascia instead of fibrin glue or Gelfoam in patients with tympanic membrane (TM) perforations. PGA sheets were placed lateral to the fascia graft attached using the underlay grafting technique in 6 patients. In each case, the PGA sheet had been macerated and had merged into the fascia within 1 week of the procedure. At 2 to 3 postoperative weeks, parts of the sheet had become dehydrated and detached from the fascia, revealing a new epithelialized TM underneath. Eventually, the sheet had disappeared, and complete epithelialization had been achieved at 4 to 5 postoperative weeks, resulting in the successful closure of the perforation. The repair of TM remained stable throughout the follow-up period of at least 6 months in all patients. These results suggest that PGA sheets have the potential to secure fascia grafts and to guide the epithelialization of new tissue. PMID:23744836

  4. Enhanced biocompatibility and antibacterial property of polyurethane materials modified with citric acid and chitosan.

    PubMed

    Liu, Tian-Ming; Wu, Xing-Ze; Qiu, Yun-Ren

    2016-08-01

    Citric acid (CA) and chitosan (CS) were covalently immobilized on polyurethane (PU) materials to improve the biocompatibility and antibacterial property. The polyurethane pre-polymer with isocyanate group was synthesized by one pot method, and then grafted with citric acid, followed by blending with polyethersulfone (PES) to prepare the blend membrane by phase-inversion method so that chitosan can be grafted from the membrane via esterification and acylation reactions eventually. The native and modified membranes were characterized by attenuated total reflectance-Fourier transform infrared spectroscope, X-ray photoelectron spectroscopy, scanning electron microscopy, water contact angle measurement, and tensile strength test. Protein adsorption, platelet adhesion, hemolysis assay, activated partial thromboplastin time, prothrombin time, thrombin time, and adsorption of Ca(2+) were executed to evaluate the blood compatibility of the membranes decorated by CA and CS. Particularly, the antibacterial activities on the modified membranes were evaluated based on a vitro antibacterial test. It could be concluded that the modified membrane had good anticoagulant property and antibacterial property. PMID:27102367

  5. Synthesis and characterization of polymeric materials derived from 2,5-diketopiperazines and pyroglutamic acid

    NASA Astrophysics Data System (ADS)

    Parrish, Dennis Arch

    The research presented in this dissertation describes the investigation of 2,5-diketopiperazines (DKPs) as property modifiers for addition polymers and the self association behavior of pyroglutamic acid derivatives. The first project involved the copolymerization of methyl methacrylate and styrene with DKP-based methacrylate monomers. Low incorporations of serine- and aspartame-based DKPs in the copolymer resulted in dramatic increases in the glass transition temperature (Ts). The research presented in Chapter II focuses on the ring-opening reactions of pyroglutamic diketopiperazine (pyDKP). The original intent was to synthesize polymers containing backbone DKPs through ring-opening polymerization of the five-membered rings. However, it was discovered that regioselective ring-opening occurs at the six-membered ring to give pyroglutamic acid derivatives. Since this reaction had not been reported previously, the focus of research was altered to investigate the scope and limitations of the new reaction. The ring-opening reactions of pyDKP with diamines to give bispyroglutamides is described in Chapter IV. While these materials are not polymeric, they display polymeric behavior. It was found that multi-functional pyroglutamides display Tgs during thermal analysis, exhibit high thermal stability, and form melt-drawn fibers. In contrast, the materials have low solution viscosities and are freely soluble in water, ethanol, and chloroform. This behavior is attributed to non-covalent supramolecular associations. The final part of this dissertation involved the investigation of thermoreversible organic solvent gelators. The ring-opening reaction of pyDKP with long alkyl amines unexpectedly gelled the reaction solvent. A series of analogous gelators were synthesized, and the minimum concentration required for gelation in various solvents was determined. It was found that the nature of the solvent, alkyl chain length, and optical activity of the gelator determined gelator

  6. Characterization and Acid-Mobilization Study of Iron-Containing Mineral Dust Source Materials

    SciTech Connect

    Cwiertny, David M.; Baltrusaitis, Jonas; Hunter, Gordon J.; Laskin, Alexander; Scherer, Michelle; Grassian, Vicki H.

    2008-03-04

    Processes that solubilize the iron in mineral dust aerosols may increase the amount of iron supplied to ocean surface waters, and thereby stimulate phytoplankton productivity. It was recently proposed that mixing of mineral dusts with SO2 and HNO3 produces extremely acidic environments that favor the formation of bioavailable Fe(II). Here, four authentic mineral dust source materials (Saudi Beach sand (SB), Inland Saudi sand (IS), Saharan Sand (SS) and China Loess (CL)) and one commercial reference material (Arizona Test Dust (AZTD)) were spectroscopically characterized, and their dissolution at pH 1 was examined in aqueous batch systems. Spectroscopic analyses indicated that the bulk and near-surface region of all samples possessed similar elemental compositions and that iron was unevenly distributed among dust 10 particles. Mössbauer spectroscopy revealed Fe(III) in all samples, although SB, CL and AZTD also contained appreciable Fe(II). Both Fe(II) and Fe(III) were primarily substituted into aluminosilicates, although CL, AZTD and IS also contained Fe(III) oxides. Total iron solubility (defined as the summed concentration of dissolved Fe(II) and Fe(III) measured after 24 h) ranged 14 between 4-12% of the source materials’ iron content, but did not scale with either the surface area or the iron content of the samples. This suggests that other factors such as iron speciation and mineralogy may play a key role in iron solubility. Also, the elevated nitrate concentrations encountered from nitric acid at pH 1 suppressed dissolution of Fe(II) from AZTD, CL and SB particles, which we propose results from the surface-mediated, non-photochemical reduction of nitrate by Fe(II).

  7. Complexes of polyvinyl alcohol with insoluble inorganic compounds

    NASA Astrophysics Data System (ADS)

    Prosanov, I. Yu.; Bulina, N. V.; Gerasimov, K. B.

    2013-10-01

    Hybrid materials of polyvinyl alcohol-hydroxides/oxides of Be, Mg, Zn, Cd, B, Al, Cr, and Fe have been obtained. The studies have been carried out by the methods of optical spectroscopy, X-ray diffraction, and synchronous thermal analysis. Interpretation of experimental data is presented, presuming that, in systems with zinc, boron, aluminum, chromium, and iron hydroxides/oxides, interpolymeric complexes of polyvinyl alcohol with corresponding polymeric inorganic compounds are formed. They belong to a new class of materials with unusual structure containing chains of inorganic polymers isolated in the organic matrix.

  8. Influence of group composition of sulfonic acids on properties of sulfonate additives

    SciTech Connect

    Katrenko, T.I.; Bessonova, R.N.; Kuznetsova, M.G.; Potolovskii, L.A.

    1983-05-01

    Three types of sulfonic acids are formed in sulfonation of petroleum oils-- oil-soluble, oil-insoluble, and water-soluble. This study investigates the influence of the different acids on neutral calcium sulfonates. Samples are recovered from As-14 oil. Oil-insoluble synthesis failed. Water-soluble acid did synthesize with a mix of oil- and water-soluble sulfonates. Neutral calcium sulfonates synthesized from oil-soluble had good properties, from oil-insoluble, bad properties. Oil-insoluble sulfonate also has an inverse effect on cleanup, and it interferes with carbonation. These findings will help with improvements in the sulfonate additive manufacturing process.

  9. Pyrene-functionalized oligonucleotides and locked nucleic acids (LNAs): Tools for fundamental research, diagnostics, and materials science†

    PubMed Central

    Østergaard, Michael E.; Hrdlicka, Patrick J.

    2013-01-01

    Pyrene-functionalized oligonucleotides (PFOs) are increasingly explored as tools in fundamental research, diagnostics and materials science. Their popularity is linked to the ability of pyrenes to function as polarity-sensitive and quenchable fluorophores, excimer-generating units, aromatic stacking moieties and nucleic acid duplex intercalators. These characteristics have motivated development of PFOs for detection of complementary DNA/RNA targets, single nucleotide polymorphisms (SNPs), and generation of π-arrays on nucleic acid scaffolds. This Review will highlight the physical properties and applications of PFOs that are likely to provide high degree of positional control of the chromophore in nucleic acid complexes. Particular emphasis will be placed on pyrene-functionalized Locked Nucleic Acids (LNAs) since these materials display distinctive properties such as large fluorescence quantum yields, efficient discrimination of SNPs, and recognition of mixed-sequence double stranded DNA. PMID:21487621

  10. Silylated melamine and cyanuric acid as precursors for imprinted and hybrid silica materials with molecular recognition properties.

    PubMed

    Arrachart, Guilhem; Carcel, Carole; Trens, Philippe; Moreau, Jöel J E; Wong Chi Man, Michel

    2009-06-15

    Two monotrialkoxysilylated compounds that consist of complementary fragments of melamine (M) and cyanuric acid (CA) have been synthesised. The molecular recognition properties of the M and CA fragments through complementary hydrogen bonds (DAD and ADA; D=donor, A=acceptor) are the key factor used to direct the formation of hybrid silica materials by using a sol-gel process. These materials were synthesised following two methods: First, an organo-bridged silsesquioxane was obtained by the hydrolysis of the two complementary monotrialkoxysilylated melamine and cyanuric acid derivatives, with fluoride ions as a catalyst. The hydrogen-bonding interactions between the two organic fragments are responsible for the formation of the bridging unit. The transcription of the assembly into the hybrid material was characterised and evidenced by solid-state NMR (29Si, 13C) and FTIR spectroscopic experiments. Second, the molecular recognition was exploited to synthesise an imprinted hybrid silica. This material was prepared by co-condensation of tetraethyl orthosilicate (TEOS) with the monosilylated cyanuric acid derivative (CA) templated by nonsilylated melamine. The melamine template was completely removed by treating the solid material with hydrochloric acid. The reintroduction of the template was performed by treating the resulting material with an aqueous suspension of melamine. These steps were monitored and analysed by several techniques, such as solid-state NMR (29Si, 13C) and FTIR spectroscopic analysis and nitrogen adsorption-desorption isotherms. PMID:19440996

  11. Physicochemical and Functional Properties of Insoluble Dietary Fiber Isolated from Bambara Groundnut (Vigna subterranea [L.] Verdc.).

    PubMed

    Diedericks, Claudine F; Jideani, Victoria A

    2015-09-01

    Bambara groundnut (BGN) is a widely cultivated legume with a rich nutritional profile, yet despite its many benefits it still remains underutilized. To highlight its potential value, 4 BGN varieties-brown, red, black eye, and brown eye were subjected to sequential enzymatic treatments followed by centrifugation to obtain the insoluble dietary fiber (IDF) fraction. The IDFs were vacuum-dried and evaluated for color, hydration properties, fat absorption, polyphenolic compounds, neutral sugars, and uronic acids. An optimized white bread formulation was also determined using brown BGN-IDF in an optimal (IV) mixture design. Three mixture components constrained at lower and upper limits (water: 57% to 60%, yeast: 2.3% to 5.3%, and BGN-IDF: 7% to 10%) were evaluated for their effects on responses of specific loaf volume, gumminess, chewiness, and resilience of the loaves. All BGN-IDFs differed significantly (P ≤ 0.05) across all color parameters. Polyphenols were significantly (P ≤ 0.05) highest in red and brown BGN-IDFs. Arabinose/galactose (31.04% to 37.12%), xylose (16.53% to 27.30%), and mannose (14.48% to 22.24%) were the major sugars identified. Swelling capacity was significantly (P ≤ 0.05) highest for brown eye BGN-IDF (7.72 ± 0.49 mL/g). Water retention capacity ranged from 1.63 to 2.01 g water/g dry weight. Fat absorption for red BGN-IDF differed significantly (P ≤ 0.05). Furthermore, the best optimal white bread formulation enriched with brown BGN-IDF was established with numerical optimization at 59.5% water, 4.3% yeast, and 8.5% BGN-IDF. Overall positive physicochemical and functional properties were observed for BGN-IDFs, and it was shown that an optimal white bread enriched with BGN-IDF could be produced. PMID:26256094

  12. Surface discharge and tracking phenomena induced on acrylonitrile-butadiene-styrene polymer dielectric material by acid rain

    NASA Astrophysics Data System (ADS)

    Wang, X.; Yoshimura, N.

    1999-05-01

    The discharge and tracking phenomena induced on the polymer dielectric materials by acid rain are investigated by the accelerated aging of acrylonitrile-butadiene-styrene copolymer in artificial rainwater in this article. Based on the investigation of acid rain, the artificial rainwater is chosen to agree well with the actual ingredients of precipitation. The influence of hydrophobicity degradation on the surface discharge and tracking is studied. The relations among the surface discharge, tracking, hydrophobicity, and microchemical structure and physical morphology of material are furthermore discussed. Experimental results show that the polymer dielectric materials suffer a large attack and degradation from acid rain. The dielectric surface degrades and becomes rough, and the hydrophobicity decreases so that the surface discharge and tracking may occur on them.

  13. Production and Cytotoxicity of Extracellular Insoluble and Droplets of Soluble Melanin by Streptomyces lusitanus DMZ-3

    PubMed Central

    Madhusudhan, D. N.; Mazhari, Bi Bi Zainab; Dastager, Syed G.

    2014-01-01

    A Streptomyces lusitanus DMZ-3 strain with potential to synthesize both insoluble and soluble melanins was detected. Melanins are quite distinguished based on their solubility for varied biotechnological applications. The present investigation reveals the enhanced production of insoluble and soluble melanins in tyrosine medium by a single culture. Streptomyces lusitanus DMZ-3 was characterized by 16S rRNA gene analysis. An enhanced production of 5.29 g/L insoluble melanin was achieved in a submerged bioprocess following response surface methodology. Combined interactive effect of temperature (50°C), pH (8.5), tyrosine (2.0 g/L), and beef extract (0.5 g/L) were found to be critical variables for enhanced production in central composite design analysis. An optimized indigenous slant culture system was an innovative approach for the successful production (264 mg/L) of pure soluble melanin from the droplets formed on the surface of the culture. Both insoluble and soluble melanins were confirmed and characterized by Chemical, reactions, UV, FTIR, and TLC analysis. First time, cytotoxic study of melanin using brine shrimps was reported. Maximum cytotoxic activity of soluble melanin was Lc50-0.40 µg/mL and insoluble melanin was Lc50-0.80 µg/mL. PMID:24839603

  14. Medical devices; immunology and microbiology devices; classification of quality control material for cystic fibrosis nucleic acid assays. Final rule.

    PubMed

    2007-01-10

    The Food and Drug Administration (FDA) is classifying quality control material for cystic fibrosis nucleic acid assays into class II (special controls). The special control that will apply to the device is the guidance document entitled "Class II Special Controls Guidance Document: Quality Control Material for Cystic Fibrosis Nucleic Acid Assays." The agency is classifying the device into class II (special controls) in order to provide a reasonable assurance of safety and effectiveness of the device. Elsewhere in this issue of the Federal Register, FDA is announcing the availability of the guidance document that will serve as the special control for this device. PMID:17294552

  15. Perfluorinated carboxylic acids in directly fluorinated high-density polyethylene material.

    PubMed

    Rand, Amy A; Mabury, Scott A

    2011-10-01

    Perfluorinated carboxylic acids (PFCAs) are ubiquitous in the environment and have been detected in human blood worldwide. One potential route is direct exposure to PFCAs through contact with polymers that have been fluorinated through a process referred to as direct fluorination. PFCAs are hypothesized to be reaction byproducts of direct fluorination when trace amounts of oxygen are present. The objective of this research was to investigate whether PFCAs could be measured in directly fluorinated high-density polyethylene (HDPE) bottles. PFCAs were quantified using Soxhlet extraction with methanol, followed by LC-MS/MS analysis. Total concentrations of PFCAs ranged from 8.5 ± 0.53 to 113 ± 2.5 ng/bottle (1 L), with the short-chain PFCAs, perfluoropropanoic, perfluorobutanoic, perfluoropentanoic, and perfluorohexanoic acids, being the dominant congeners observed. Relative PFCA concentrations varied depending on fluorination level. Structural isomers were detected using (19)F NMR and are hypothesized to have formed during the fluorination process; NMR data revealed the linear isomer typically comprised 55% of the examined sample. Internally branched, isopropyl branched, and t-butyl PFCA isomers of varying chain length were also identified. Electrochemical fluorination was previously thought to be the only source of branched PFCA isomers. The observation here of branched isomers suggests direct fluorination may be an additional source of exposure to these chemicals. The purpose of this study was to measure PFCAs in directly fluorinated material, serving as a previously unidentified source contributing to the environmental load of PFCAs, with potential for human exposure. PMID:21688793

  16. Effects of material thickness and processing method on poly(lactic-co-glycolic acid) degradation and mechanical performance.

    PubMed

    Shirazi, Reyhaneh Neghabat; Aldabbagh, Fawaz; Ronan, William; Erxleben, Andrea; Rochev, Yury; McHugh, Peter

    2016-10-01

    In this study, the effects of material thickness and processing method on the degradation rate and the changes in the mechanical properties of poly(lactic-co-glycolic acid) material during simulated physiological degradation were investigated. Two types of poly(lactic-co-glycolic acid) materials were considered: 0.12 mm solvent-cast films and 1 mm compression-moulded plates. The experimental results presented in this study were compared to the experimental results of Shirazi et al. (Acta Biomaterialia 10(11):4695-703, 2014) for 0.25 mm solvent-cast films. These experimental observations were used to validate the computational modelling predictions of Shirazi et al. (J Mech Behav Biomed Mater 54: 48-59, 2016) on critical diffusion length scale and also to refine the model parameters. The specific material processing methods considered here did not have a significant effect on the degradation rate and the changes in mechanical properties during degradation; however, they influenced the initial molecular weight and they determined the stiffness and hardness of the poly(lactic-co-glycolic acid) material. The experimental observations strongly supported the computational modelling predictions that showed no significant difference in the degradation rate and the changes in the elastic modulus of poly(lactic-co-glycolic acid) films for thicknesses larger than 100 μm. PMID:27590824

  17. Ingestion of insoluble dietary fibre increased zinc and iron absorption and restored growth rate and zinc absorption suppressed by dietary phytate in rats.

    PubMed

    Hayashi, K; Hara, H; Asvarujanon, P; Aoyama, Y; Luangpituksa, P

    2001-10-01

    We examined the effects of ingestion of five types of insoluble fibre on growth and Zn absorption in rats fed a marginally Zn-deficient diet (6.75 mg (0.103 mmol) Zn/kg diet) with or without added sodium phytate (12.6 mmol/kg diet). The types of insoluble fibre tested were corn husks, watermelon skin, yam-bean root (Pachyrhizus erosus) and pineapple core, and cellulose was used as a control (100 g/kg diet). Body-weight gain in the cellulose groups was suppressed by 57 % by feeding phytate. Body-weight gain in phytate-fed rats was 80 % greater in the watermelon skin fibre and yam-bean root fibre group than that in the cellulose group. Zn absorption ratio in the cellulose groups was lowered by 46 and 70 % in the first (days 7-10) and second (days 16-19) measurement periods with feeding phytate. In the rats fed the phytate-containing diets, Zn absorption ratio in the watermelon skin, yam-bean root and pineapple core fibre groups was 140, 80 and 54 % higher respectively than that in the cellulose group, in the second period. Fe absorption was not suppressed by phytate, however, feeding of these three types of fibre promoted Fe absorption in rats fed phytate-free diets. The concentration of soluble Zn in the caecal contents in the watermelon skin fibre or yam-bean root fibre groups was identical to that in the control group in spite of a higher short-chain fatty acid concentration and lower pH in the caecum. These findings indicate that ingestion of these types of insoluble fibre recovered the growth and Zn absorption suppressed by feeding a high level of phytate, and factors other than caecal fermentation may also be involved in this effect of insoluble fibre. PMID:11591231

  18. Amino acids and amino sugars of surface particulate and sediment trap material from waters of the Scotia sea

    NASA Astrophysics Data System (ADS)

    Müller, Peter J.; Suess, Erwin; AndréUngerer, C.

    1986-06-01

    Two coarse suspended matter size classes (75-150 μm, >150 μm), from subantarctic and Antarctic surface waters in the Scotia Sea, and sediment trap material from the Drake Passage were analyzed for their elemental, amino acid and amino sugar compositions. Different proportions of biogenic silica and organic matter in the particulates of both regions reflect a zonation of primary producers, with diatoms predominating in the waters south of the Polar Front. High SiO 2:C org ratios, elevated proportions of hydroxyl amino acids, and essentially identical amino acid compositions for both size classes indicate that diatoms account for a major portion of the particulate proteinaceous material from Antarctic surface waters. Of the two amino sugars, glucosamine and galactosamine, only the former was detected in significant amounts in the surface particulates. The total amino acid : glucosamine ratio was lowest in surface particulates of subantarctic waters and increased with increasing latitude in Antarctic waters, reaching the highest values in the region of the Bransfield Strait. Moreover, amino acid : glucosamine ratios suggest day-night differences in particulate matter resulting from primary productivity in conjunction with the feeding behavior of vertical migrators. Significantly different amino acid and amino sugar compositions of the surface particulate matter >75 μm in size and the sediment trap material reflect fractionation processes at shallow depths. Remineralization and digestion of organic matter appear to result in a relative enrichment of structural components (diatom cell walls, chitinaceous matter) in fecal pellets and other large aggregates. The preferential preservation of diatom cell wall material is indicated by a strong relative enrichment of glycine and hydroxyl amino acids in the sediment trap material in conjunction with high biogenic silica:organic carbon ratios. Similarly, low amino acid:glucosamine ratios in the sediment trap material from

  19. On the acidity of saponite materials: a combined HRTEM, FTIR, and solid-state NMR study.

    PubMed

    Bisio, C; Gatti, G; Boccaleri, E; Marchese, L; Bertinetti, L; Coluccia, S

    2008-03-18

    Acid clays were prepared by exchanging a synthetic saponite in HCl solutions of different concentration (0.01 and 1M, respectively). A combined experimental approach (XRD, HRTEM, N2 physisorption, solid-state MAS NMR, and TGA) was used to investigate on the structural, morphological, and textural features of the samples treated under mild and strong acid conditions. FTIR spectroscopy of adsorbed probe molecules with different basicity (e.g., CO and NH3) was used to monitor the surface acid properties and acid site distribution. XRD and SS-MAS NMR indicated that the activation under mild acid conditions does not alter the clay structure, while a deep modification of the saponite framework occurred after ion exchange in 1 M HCl solution. The presence of porous amorphous silica phase after treatment under strong acid conditions was confirmed by TEM inspection augmented by SS-MAS NMR and FTIR spectroscopy. N2 and Ar physisorption measurements suggested that cavitation phenomena occurred in saponite structure. N2 physisorption confirmed that the porosity and surface area of the samples are strongly modified upon strong acid treatment. FTIR spectroscopy of adsorbed NH3 pointed out that the H-exchange in mild conditions increased the number of surface Brønsted acid sites. Conversely, these sites are significantly depleted after treatment under strong acid conditions. The use of CO as a FTIR probe molecule, which is applied for the first time to study synthetic acid clays, allowed to monitor distribution and strength of Brønsted acid sites, whose acidity is similar to that of strong acid zeolites. The Al-OH sites with medium acidity are also found in acid-activated saponites. The distribution of strong and medium acid sites is strictly dependent on the acid conditions adopted. PMID:18251562

  20. An In Situ Method for Sizing Insoluble Residues in Precipitation and Other Aqueous Samples

    PubMed Central

    Axson, Jessica L.; Creamean, Jessie M.; Bondy, Amy L.; Capracotta, Sonja S.; Warner, Katy Y.; Ault, Andrew P.

    2015-01-01

    Particles are frequently incorporated into clouds or precipitation, influencing climate by acting as cloud condensation or ice nuclei, taking up coatings during cloud processing, and removing species through wet deposition. Many of these particles, particularly ice nuclei, can remain suspended within cloud droplets/crystals as insoluble residues. While previous studies have measured the soluble or bulk mass of species within clouds and precipitation, no studies to date have determined the number concentration and size distribution of insoluble residues in precipitation or cloud water using in situ methods. Herein, for the first time we demonstrate that Nanoparticle Tracking Analysis (NTA) is a powerful in situ method for determining the total number concentration, number size distribution, and surface area distribution of insoluble residues in precipitation, both of rain and melted snow. The method uses 500 μL or less of liquid sample and does not require sample modification. Number concentrations for the insoluble residues in aqueous precipitation samples ranged from 2.0–3.0(±0.3)×108 particles cm−3, while surface area ranged from 1.8(±0.7)–3.2(±1.0)×107 μm2 cm−3. Number size distributions peaked between 133–150 nm, with both single and multi-modal character, while surface area distributions peaked between 173–270 nm. Comparison with electron microscopy of particles up to 10 μm show that, by number, > 97% residues are <1 μm in diameter, the upper limit of the NTA. The range of concentration and distribution properties indicates that insoluble residue properties vary with ambient aerosol concentrations, cloud microphysics, and meteorological dynamics. NTA has great potential for studying the role that insoluble residues play in critical atmospheric processes. PMID:25705069

  1. Timolol maleate release from hyaluronic acid-containing model silicone hydrogel contact lens materials.

    PubMed

    Korogiannaki, Myrto; Guidi, Giuliano; Jones, Lyndon; Sheardown, Heather

    2015-09-01

    This study was designed to assess the impact of a releasable wetting agent, such as hyaluronic acid (HA), on the release profile of timolol maleate (TM) from model silicone hydrogel contact lens materials. Polyvinylpyrrolidone (PVP) was used as an alternative wetting agent for comparison. The model lenses consisted of a hydrophilic monomer, either 2-hydroxyethyl methacrylate or N,N-dimethylacrylamide and a hydrophobic silicone monomer of methacryloxypropyltris (trimethylsiloxy) silane. The loading of the wetting and the therapeutic agent occurred during the synthesis of the silicone hydrogels through the method of direct entrapment. The developed materials were characterized by minimal changes in the water uptake, while lower molecular weight of HA improved their surface wettability. The transparency of the examined silicone hydrogels was found to be affected by the miscibility of the wetting agent in the prepolymer mixture as well as the composition of the developed silicone hydrogels. Sustained release of TM from 4 to 14 days was observed, with the drug transport occurring presumably through the hydrophilic domains of the silicone hydrogels. The release profile was strongly dependent on the hydrophilic monomer composition, the distribution of hydrophobic (silane) domains, and the affinity of the therapeutic agent for the silicone hydrogel matrix. Noncovalent entrapment of the wetting agent did not change the in vitro release duration and kinetics of TM, however the drug release profile was found to be controlled by the simultaneous release of TM and HA or PVP. In the case of HA, depending on the HA:drug ratio, the release rate was decreased and controlled by the release of HA, likely due to electrostatic interactions between protonated TM and anionic HA. Overall, partitioning of the drug within the hydrophilic domains of the silicone hydrogels as well as interactions with the wetting agent determined the drug release profile. PMID:25887216

  2. The effect of water on the mechanical properties of soluble and insoluble ceramic cements.

    PubMed

    Koh, Ilsoo; López, Alejandro; Pinar, Ana B; Helgason, Benedikt; Ferguson, Stephen J

    2015-11-01

    Ceramic cements are good candidates for the stabilization of fractured bone due to their potential ease of application and biological advantages. New formulations of ceramic cements have been tested for their mechanical properties, including strength, stiffness, toughness and durability. The changes in the mechanical properties of a soluble cement (calcium sulfate) upon water-saturation (saturation) was reported in our previous study, highlighting the need to test ceramic cements using saturated samples. It is not clear if the changes in the mechanical properties of ceramic cements are exclusive to soluble cements. Therefore the aim of the present study was to observe the changes in the mechanical properties of soluble and insoluble ceramic cements upon saturation. A cement with high solubility (calcium sulfate dihydrate, CSD) and a cement with low solubility (dicalcium phosphate dihydrate, DCPD) were tested. Three-point bending tests were performed on four different groups of: saturated CSD, non-saturated CSD, saturated DCPD, and non-saturated DCPD samples. X-ray diffraction analysis and scanning electron microscopy were also performed on a sample from each group. Flexural strength, effective flexural modulus and flexural strain at maximum stress, lattice volume, and crystal sizes and shape were compared, independently, between saturated and non-saturated groups of CSD and DCPD. Although material dissolution did not occur in all cases, all calculated mechanical properties decreased significantly in both CSD and DCPD upon saturation. The results indicate that the reductions in the mechanical properties of saturated ceramic cements are not dependent on the solubility of a ceramic cement. The outcome raised the importance of testing any implantable ceramic cements in saturated condition to estimate its in vivo mechanical properties. PMID:26210548

  3. A successful strategy for the recovering of active P21, an insoluble recombinant protein of Trypanosoma cruzi

    NASA Astrophysics Data System (ADS)

    Santos, Marlus Alves Dos; Teixeira, Francesco Brugnera; Moreira, Heline Hellen Teixeira; Rodrigues, Adele Aud; Machado, Fabrício Castro; Clemente, Tatiana Mordente; Brigido, Paula Cristina; Silva, Rebecca Tavares E.; Purcino, Cecílio; Gomes, Rafael Gonçalves Barbosa; Bahia, Diana; Mortara, Renato Arruda; Munte, Claudia Elisabeth; Horjales, Eduardo; da Silva, Claudio Vieira

    2014-03-01

    Structural studies of proteins normally require large quantities of pure material that can only be obtained through heterologous expression systems and recombinant technique. In these procedures, large amounts of expressed protein are often found in the insoluble fraction, making protein purification from the soluble fraction inefficient, laborious, and costly. Usually, protein refolding is avoided due to a lack of experimental assays that can validate correct folding and that can compare the conformational population to that of the soluble fraction. Herein, we propose a validation method using simple and rapid 1D 1H nuclear magnetic resonance (NMR) spectra that can efficiently compare protein samples, including individual information of the environment of each proton in the structure.

  4. Contemporaneous isolation of deoxyribonucleic acid-dependent ribonucleic acid polymerase and poly(A) polymerase from rat liver mitochondria.

    PubMed Central

    Gallerani, R; di Istituto; Istituto di, Ch; Saccone, C

    1976-01-01

    1. Poly(A) polymerase and DNA-dependent RNA polymerase from rat liver mitochondria can be completely separated by using two different chromatographic procedures. 2. Poly(A) polymerase can only incorporate ATP into acid-insoluble material and strongly depends on the addition of an endogenous factor (probably containing a mixture of oligoribonucleotides), but it is not stimulated by DNA. 3. RNA polymerase is fully DNA-dependent and rifampicin-sensitive, but was not stimulated by the endogenous factor mentioned above. 4. The chromatographic behaviour of the two enzymes, together with the properties described, suggest that they represent two different protein molecules. PMID:962867

  5. 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. PMID:18693011

  6. Element-Doped Polyacrylic Acid Thin Films as SIMS Standards for Organic Materials

    NASA Astrophysics Data System (ADS)

    Davisson, M.; Phinney, D. L.; Weber, P. K.

    2009-12-01

    To constrain relative sensitive factors for SIMS elemental analysis of organic materials, calibration standards are being developed by coordinating ppm quantities of Group I, Group II, and transition metals with polyacrylic acid resin and depositing them as thin films. Each element is prepared as an aqueous acetate, oxalate, or nitrate solution to avoid unwanted elements that compromise thin film uniformity or produce interfering masses. These are subsequently mixed proportionally with reagent grade resins (Mw ~2000 and ~50,000), and dried passively on an Al bullet or spin-coated for thin layering (~100nm). Initial results using an O- primary beam on a Cameca NanoSIMS demonstrate excellent lateral homogeneity for Na, K, Fe, Co, and Cd at nanometer scale and consistent ratios to 12C (stdev <10%) over multiple 10um raster areas, whereas Mg, Ca, Sr, and Cu show variable ratios to 12C over sputter depth (stdev >10%). Depth profiling over the entire film thickness using a Cameca 3f show high reproducibility of element trends at 250um raster areas. Additional measurements will incorporate multi-element suites of biologically-relevant species (e.g. Na, K, Ca, P) to facilitate quantitative analysis of sensitivity factors with compositional changes.

  7. Hydrothermal treatment of MSWI bottom ash forming acid-resistant material.

    PubMed

    Etoh, Jiro; Kawagoe, Takeshi; Shimaoka, Takayuki; Watanabe, Koichiro

    2009-03-01

    To recycle municipal solid waste incinerator (MSWI) bottom ash, synthesis of hydrothermal minerals from bottom ash was performed to stabilize heavy metals. MSWI bottom ash was mixed with SiO(2), Al(OH)(3), and Mg(OH)(2) so its chemical composition was similar to that of hydrothermal clay minerals. These solid specimens were mixed with water at a liquid/solid ratio of 5. The reaction temperature was 200 degrees C, and reactions were performed for 24-240h. Generation of kaolinite/smectite mixed-layer clay mineral was found in the samples after the reaction of the mixture of bottom ash, SiO(2), and Mg(OH)(2). Calcium silicate hydrate minerals such as tobermorite and xonotlite were also generated. X-ray powder diffraction suggested the presence of amorphous materials. Leaching tests at various pHs revealed that the concentration of heavy metals in the leachates from MSWI bottom ash hydrothermally treated with SiO(2) and Mg(OH)(2) was lower than that in leachates from non-treated bottom ash, especially under acid conditions. Hydrothermal treatment with modification of chemical composition may have potential for the recycling of MSWI bottom ash. PMID:18845427

  8. Hydrothermal treatment of MSWI bottom ash forming acid-resistant material

    SciTech Connect

    Etoh, Jiro Kawagoe, Takeshi; Shimaoka, Takayuki; Watanabe, Koichiro

    2009-03-15

    To recycle municipal solid waste incinerator (MSWI) bottom ash, synthesis of hydrothermal minerals from bottom ash was performed to stabilize heavy metals. MSWI bottom ash was mixed with SiO{sub 2}, Al(OH){sub 3}, and Mg(OH){sub 2} so its chemical composition was similar to that of hydrothermal clay minerals. These solid specimens were mixed with water at a liquid/solid ratio of 5. The reaction temperature was 200 deg. C, and reactions were performed for 24-240 h. Generation of kaolinite/smectite mixed-layer clay mineral was found in the samples after the reaction of the mixture of bottom ash, SiO{sub 2}, and Mg(OH){sub 2}. Calcium silicate hydrate minerals such as tobermorite and xonotlite were also generated. X-ray powder diffraction suggested the presence of amorphous materials. Leaching tests at various pHs revealed that the concentration of heavy metals in the leachates from MSWI bottom ash hydrothermally treated with SiO{sub 2} and Mg(OH){sub 2} was lower than that in leachates from non-treated bottom ash, especially under acid conditions. Hydrothermal treatment with modification of chemical composition may have potential for the recycling of MSWI bottom ash.

  9. Tough and elastic hydrogel of hyaluronic acid and chondroitin sulfate as potential cell scaffold materials.

    PubMed

    Ni, Yilu; Tang, Zhurong; Cao, Wanxu; Lin, Hai; Fan, Yujiang; Guo, Likun; Zhang, Xingdong

    2015-03-01

    Natural polysaccharides are extensively investigated as cell scaffold materials for cellular adhesion, proliferation, and differentiation due to their excellent biocompatibility, biodegradability, and biofunctions. However, their application is often severely limited by their mechanical behavior. In this study, a tough and elastic hydrogel scaffold was prepared with hyaluronic acid (HA) and chondroitin sulfate (CS). HA and CS were conjugated with tyramine (TA) and the degree of substitution (DS) was 10.7% and 11.3%, respectively, as calculated by (1)H NMR spectra. The hydrogel was prepared by mixing HA-TA and CS-TA in presence of H2O2 and HRP. The sectional morphology of hydrogels was observed by SEM, static and dynamic mechanical properties were analyzed by Shimadzu electromechanical testing machine and dynamic mechanical thermal analyzer Q800. All samples showed good ability to recover their appearances after deformation, the storage modulus (E') of hydrogels became higher as the testing frequency went up. Hydrogels also showed fatigue resistance to cyclic compression. Mesenchymal stem cells encapsulated in hydrogels showed good cell viability as detected by CLSM. This study suggests that the hydrogels have both good mechanical properties and biocompatibility, and may serve as model systems to explore mechanisms of deformation and energy dissipation or find some applications in tissue engineering. PMID:25445680

  10. Use of wet FGD material for revegetation of an abandoned acidic coal refuse pile

    SciTech Connect

    Mafi, S.; Stehouwer, R.C.

    1996-12-31

    Wet FGD material has a neutralizing potential of 15% CaCO{sub 3}. These properties may make it a beneficial amendment for revegetation of hyper-acidic coal refuse. In greenhouse and field experiments, coal refuse (pH = 2.5) was amended with wet FGD (300, 500, and 700 tons/acre). Amendment with FGD was as effective as agricultural lime (AL) in increasing refuse pH and decreasing soluble Al and Fe. Addition of compost to the FGD further increased pH and decreased soluble Al and Fe. Downward transport of Ca was greater with FGD than AL, but FGD did not increase leachate concentrations of S. Amendment with FGD increased refuse, leachate and plant tissue concentrations of B. Other trace elements were not increased by FGD. In the greenhouse, plant growth was similar with AL and FGD except during the first three months when AL produced more growth than FGD. The initial growth suppression by FGD was likely due to high soluble salts, and possibly by high B concentrations. During the first year of the field experiment plant growth was greater with FGD than with AL. In both the field and greenhouse experiments compost increased plant growth when combined with FGD. These experiments show revegetation of toxic coal refuse and improvement in drainage water quality is possible by amendment with FGD. Revegetation success will be improved by combined amendment with FGD and compost.

  11. Material balance studies with continuous SSF for ethanol production using dilute-acid pretreated hybrid popular

    SciTech Connect

    Kadam, K.L.; Hayward, T.K.; Philippidis, G.P.

    1995-10-01

    Simultaneous saccharification and fermentation (SSF) is a leading process option for converting lignocellulosic biomass to ethanol. Economic industrial production of ethanol by SSF would likely require a continuous mode of operation, and development of a database on continuous SSF using industrial substrates is essential. To this end, a single-stage continuous SSF system was designed and used for studying ethanol production by Saccharomyces cerevisiae strain D{sub 5}A with dilute-acid preheated hybrid poplar as substrate. Material balance studies were conducted using the bench-scale system; the objectives of these studies were to gain insight into how the cells allocate carbon and to account for all the substrate flowing through the system. It was possible to close the total mass and carbon balances with {+-}3% accuracy, which is within the limits of experimental error. In a typical continuous SSF run, about 57% of the consumed carbon was used to produce ethanol and less than 1% to synthesize cell mass; thus the majority of carbon flow was to ethanol. The ethanol yields based on consumed substrate and volumetric productivities were in the range of 85% and 0.2 g ethanol/l{times}h, respectively; both values are within the expectations for a nearterm biomass-to-ethanol process. In the single-stage system used, continuous inoculation was not needed even for whole-slurry fermentations; this has significant economic implications since the inoculum cost can be significant.

  12. 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. PMID:24690466

  13. Gelation properties of spent duck meat surimi-like material produced using acid-alkaline solubilization methods.

    PubMed

    Nurkhoeriyati, T; Huda, N; Ahmad, R

    2011-01-01

    The gelation properties of spent duck meat surimi-like material produced using acid solubilization (ACS) or alkaline solubilization (ALS) were studied and compared with conventionally processed (CON) surimi-like material. The ACS process yielded the highest protein recovery (P < 0.05). The ALS process generated the highest lipid reduction, and the CON process yielded the lowest reduction (P < 0.05). Surimi-like material produced by the CON process had the highest gel strength, salt extractable protein (SEP), and water holding capacity (WHC), followed by materials produced via the ALS and ACS processes and untreated duck meat (P < 0.05). The material produced by the CON process also had the highest cohesiveness, hardness, and gumminess values and the lowest springiness value. Material produced by the ACS and ALS processes had higher whiteness values than untreated duck meat gels and gels produced by the CON method (P < 0.05). Surimi-like material produced using the ACS and CON processes had significantly higher myoglobin removal (P < 0.05) than that produced by the ALS method and untreated duck meat. Among all surimi-like materials, the highest Ca(2+)-ATPase activity was found in conventionally produced gels (P < 0.05). This suggests that protein oxidation was induced by acid-alkaline solubilization. The gels produced by ALS had a significantly lower (P < 0.05) total SH content than the other samples. This result showed that the acid-alkaline solubilization clearly improved gelation and color properties of spent duck and possibly applied for other high fat raw material. PMID:21535715

  14. Development of novel mesoporous nanomatrix-supported lipid bilayers for oral sustained delivery of the water-insoluble drug, lovastatin.

    PubMed

    Zhang, Yanzhuo; Zhang, Heran; Che, Erxi; Zhang, Lihua; Han, Jin; Yang, Yihua; Wang, Siling; Zhang, Miao; Gao, Cunqiang

    2015-04-01

    The purpose of this study was to investigate the effect of a core/shell structured nanocomposite, mesoporous nanomatrix-supported lipid bilayer (MN-SLB), as an oral drug nanocarrier, on the dissolution behavior and in vivo absorption of a water-insoluble drug, lovastatin (LOV). The formulation strategy was based on the use of drug-loaded mesoporous silica as the core for the fusion of liposomes. Field emission scanning electron microscopy (FESEM), cryogenic transmission electron microscopy (Cryo-TEM) and nitrogen adsorption were used to systematically characterize the drug carrier and drug-loaded MN-SLB formulation, confirming the successful inclusion of LOV into the nano-pores of MN-SLB. Powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) confirmed that the incorporated drug in the carrier was in an amorphous state. An in vitro dissolution study showed that LOV-loaded MN-SLB exhibited a sustained drug release behavior. Compared with the LOV-loaded mesoporous silica particles, LOV-loaded MN-SLB markedly suppressed the burst release. Furthermore, the pharmacokinetics and relative bioavailability of the LOV-loaded MN-SLB formulation was studied in beagle dogs after oral administration and using a commercially available immediate release formulation (Sandoz Lovastatin®) as a reference. It was found that the relative bioavailability of LOV and LOV β-hydroxy acid (LOVA) for the LOV-loaded MN-SLB formulation was 207.2% and 192.1%, respectively. In addition, MN-SLB exhibited negligible toxicity against Caco-2 and HT-29 cells in cytotoxicity assays. The results of this study indicate that the MN-SLB nanocomposite is a promising candidate as a novel oral drug delivery nanovehicle for controlling the dissolution rate and improving the oral absorption of water-insoluble drugs. PMID:25731096

  15. Overexpression of Aspergillus tubingensis faeA in protease-deficient Aspergillus niger enables ferulic acid production from plant material.

    PubMed

    Zwane, Eunice N; Rose, Shaunita H; van Zyl, Willem H; Rumbold, Karl; Viljoen-Bloom, Marinda

    2014-06-01

    The production of ferulic acid esterase involved in the release of ferulic acid side groups from xylan was investigated in strains of Aspergillus tubingensis, Aspergillus carneus, Aspergillus niger and Rhizopus oryzae. The highest activity on triticale bran as sole carbon source was observed with the A. tubingensis T8.4 strain, which produced a type A ferulic acid esterase active against methyl p-coumarate, methyl ferulate and methyl sinapate. The activity of the A. tubingensis ferulic acid esterase (AtFAEA) was inhibited twofold by glucose and induced twofold in the presence of maize bran. An initial accumulation of endoglucanase was followed by the production of endoxylanase, suggesting a combined action with ferulic acid esterase on maize bran. A genomic copy of the A. tubingensis faeA gene was cloned and expressed in A. niger D15#26 under the control of the A. niger gpd promoter. The recombinant strain has reduced protease activity and does not acidify the media, therefore promoting high-level expression of recombinant enzymes. It produced 13.5 U/ml FAEA after 5 days on autoclaved maize bran as sole carbon source, which was threefold higher than for the A. tubingensis donor strain. The recombinant AtFAEA was able to extract 50 % of the available ferulic acid from non-pretreated maize bran, making this enzyme suitable for the biological production of ferulic acid from lignocellulosic plant material. PMID:24664515

  16. Determination of insoluble, soluble, and total dietary fiber (CODEX definition) by enzymatic-gravimetric method and liquid chromatography: collaborative study.

    PubMed

    McCleary, Barry V; DeVries, Jonathan W; Rader, Jeanne I; Cohen, Gerald; Prosky, Leon; Mugford, David C; Okuma, Kazuhiro

    2012-01-01

    A method for the determination of insoluble (IDF), soluble (SDF), and total dietary fiber (TDF), as defined by the CODEX Alimentarius, was validated in foods. Based upon the principles of AOAC Official Methods 985.29, 991.43, 2001.03, and 2002.02, the method quantitates water-insoluble and water-soluble dietary fiber. This method extends the capabilities of the previously adopted AOAC Official Method 2009.01, Total Dietary Fiber in Foods, Enzymatic-Gravimetric-Liquid Chromatographic Method, applicable to plant material, foods, and food ingredients consistent with CODEX Definition 2009, including naturally occurring, isolated, modified, and synthetic polymers meeting that definition. The method was evaluated through an AOAC/AACC collaborative study. Twenty-two laboratories participated, with 19 laboratories returning valid assay data for 16 test portions (eight blind duplicates) consisting of samples with a range of traditional dietary fiber, resistant starch, and nondigestible oligosaccharides. The dietary fiber content of the eight test pairs ranged from 10.45 to 29.90%. Digestion of samples under the conditions of AOAC 2002.02 followed by the isolation, fractionation, and gravimetric procedures of AOAC 985.29 (and its extensions 991.42 and 993.19) and 991.43 results in quantitation of IDF and soluble dietary fiber that precipitates (SDFP). The filtrate from the quantitation of water-alcohol-insoluble dietary fiber is concentrated, deionized, concentrated again, and analyzed by LC to determine the SDF that remains soluble (SDFS), i.e., all dietary fiber polymers of degree of polymerization = 3 and higher, consisting primarily, but not exclusively, of oligosaccharides. SDF is calculated as the sum of SDFP and SDFS. TDF is calculated as the sum of IDF and SDF. The within-laboratory variability, repeatability SD (Sr), for IDF ranged from 0.13 to 0.71, and the between-laboratory variability, reproducibility SD (SR), for IDF ranged from 0.42 to 2.24. The within

  17. Purification and properties of glucosyltransferase responsible for water-insoluble glucan synthesis from Streptococcus mutans.

    PubMed Central

    Fukui, K; Moriyama, T; Miyake, Y; Mizutani, K; Tanaka, O

    1982-01-01

    A glucosyltransferase responsible for water-insoluble glucan synthesis was purified from the culture fluids of Streptococcus mutans 6715-15 strain by column chromatography on Toyopearl HW-60 and subsequently on hydroxyapatite. The enzyme preparation gave a single band on analysis by polyacrylamide gel electrophoresis. The pH dependency of the activity showed two optimal peaks at 5.8 and 7.3 and the Km values for sucrose were 1.4 and 3.3 mM at the respective optimal pHs. The molecular weight determined by sodium dodecyl sulfate gel electrophoresis was 180,000. Although the enzyme scarcely synthesized water-insoluble and water-soluble glucans from sucrose, water-insoluble glucan formed from sucrose in the presence of dextran T10 consisted of over 93% alpha-1, 3-glucosidic linkage. Analysis of the structure of water-insoluble glucan indicated that the enzyme catalyzed the formation of branch points in alpha-1,6-glucan (dextran) and transferred the glucosyl moiety of sucrose to the C-3 position of the branching glucose residue of dextran. Since this enzyme has not yet been registered, we named it mutansynthetase (EC 2.4.1.?). Images PMID:6179873

  18. Turning a Water And Oil Insoluble Cisplatin Derivative into a Nanoparticle Formulation for Cancer Therapy

    PubMed Central

    Guo, Shutao; Wang, Yuhua; Miao, Lei; Xu, Zhenghong; Lin, C. Michael; Huang, Leaf

    2014-01-01

    The formulation of water insoluble organic compounds into nanoparticles has become a widely established method for enhancing the delivery and efficacy of cancer therapeutics. Therefore, a comparable approach when applied to water insoluble inorganic compounds should also promote similar advantages. Herein, we have successfully formulated insoluble iodinated cisplatin (CDDP-I) into a LPI NPs (lipid-coated iodinated CDDP nanoparticles). Two separate microemulsions were combined, each containing a precursor for the synthesis of CDDP-I. The resulting CDDP-I precipitate was then coated with an anionic lipid and dispersed in water with the help of an additional lipid. This method allows us to effectively encapsulate CDDP-I and was able to achieve a considerable drug loading of 82 wt%. Administered LPI NPs demonstrated high level accumulation in tumor tissues and exhibited an anti-cancer activity comparable to free CDDP in two melanoma xenograft models without inducing nephrotoxocity. The benefits offered through this delivery formulation are not unique to CDDP-I, as this versatile platform may be extended to the formulation of other inorganic compounds that are both water and oil insoluble into nanoparticles for superior anticancer efficacy. PMID:24920436

  19. Secreted expression of Leuconostoc mesenteroides glucansucrase in Lactococcus lactis for the production of insoluble glucans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We expressed a glucansucrase, DsrI, from Leuconostoc mesenteroides that catalyzes formation of water-insoluble glucans from sucrose in Lactococcus lactis using a nisin-controlled gene expression system. Production of DsrI was optimized using several different background vectors, signal peptides, str...

  20. FURTHER DEVELOPMENT OF RODENT WHOLE EMBRYO CULTURE: SOLVENT TOXICITY AND WATER INSOLUBLE COMPOUND DELIVERY SYSTEM

    EPA Science Inventory

    In order to study the in vitro embryotoxicity and dysmorphogenesis of water insoluble compounds, solvents or chemical delivery systems of low toxicity and teratogenicity to the developing embryo must be found. Therefore, day 10.5 rat embryos were cultured for 2 days in whole rat ...

  1. REMOVAL OF HEAVY METALS FROM INDUSTRIAL WASTEWATERS USING INSOLUBLE STARCH XANTHATE

    EPA Science Inventory

    The Northern Regional Research Center developed an effective process to remove heavy metals from wastewaters of two nonferrous metal industries and insoluble starch xanthate (ISX). The study included bench-scale evaluation of wastewaters from two lead battery and one brass mill w...

  2. Analysis of dietary insoluble and soluble fiber contents in school meal

    PubMed Central

    2012-01-01

    The objective of this study was to estimate the contents of dietary insoluble and soluble fiber in school meal. Samples of the school meals were collected from May to June in 2008. Three elementary schools and three middle schools around Masan area were selected for analysis. Dietary soluble and insoluble fibers in the school meals were analyzed directly by the AOAC method. From the initial experiment phase, we used cellulose and pectin as a standard of dietary fiber, and average recovery rate of insoluble fiber and soluble fiber was calculated. The recovery rate was observed, the cellulose 109.7±11.7% (range 90~150%) and pectin 77.8±10.8% (range 64.7~96.7%), respectively. The amounts of insoluble fiber and soluble fiber were analyzed in the total of 66 dishes, which included 7 kinds of cooked rice (bab) made with some cereal products and vegetables, 19 kinds of soup (guk) made with meats or vegetables, 11 kinds of kimchi, 21 kinds of entrées or side dishes, and 8 special dishes. Conclusively the school meal, per serving size, would provide above 75% KDRI of total dietary fibers through mainly soups and special menu, with the exception to fruits. In addition, it might be expected that children could consume more soluble fiber from the meals with the special dishes than from the regular ones. PMID:22413038

  3. The fluorimetric determination of oxalic acid in blood and other biological materials

    PubMed Central

    Zarembski, P. M.; Hodgkinson, A.

    1965-01-01

    1. Oxalic acid is separated from interfering substances by extraction with tri-n-butyl phosphate followed by co-precipitation with calcium sulphate. The precipitated oxalic acid is then reduced to glyoxylic acid, which is coupled with resorcinol to form a coloured fluorescent complex. 2. The spectrofluorometric method described is sensitive and highly specific, the minimum detectable amount of oxalic acid being 0·9μmole under the recommended conditions. 3. The concentration of oxalic acid in blood from 15 normal adults was 200–320μg./100ml. For serum the range was 135–280μg./100ml. The urinary excretion of oxalic acid by 60 normal adults on a normal diet was 9·0–28·5mg./24hr. PMID:5862411

  4. Amino acid composition of suspended particles, sediment-trap material, and benthic sediment in the Potomac Estuary

    USGS Publications Warehouse

    Sigleo, A.C.; Shultz, D.J.

    1993-01-01

    Sediment trap deployments in estuaries provide a method for estimating the amount of organic material transported to the sediments from the euphotic zone. The amino acid composition of suspended particles, benthic sediment, and sediment-trap material collected at 2.4 m, 5.8 m, and 7.9 m depths in the Potomac Estuary was determined in stratified summer waters, and in well-mixed oxygenated waters (DO) in late fall. The total vertical flow, or flux, of material into the top traps ranged from 3 g m-2 d-1 in August to 4.9 g m-2 d-1 in October. The carbon and nitrogen fluxes increased in the deepest traps relative to the surface traps during both sampling periods, along with that of the total material flux (up to 47.3 g m-2 d-1 in the deepest trap), although the actual weight percent of organic carbon and organic nitrogen decreased with depth. Amino acid concentrations ranged from 129 mg g-1 in surface water particulate material to 22 mg g-1 in particulate material in 9-m-deep waters and in the benthic sediment. Amino acid concentrations from 2.4-mg-depth sediment traps averaged 104??29 mg g-1 in stratified waters and 164??81 mg g-1 in well-mixed waters. The deep trap samples averaed, 77.3??4.8 mg g-1 amino acids in summer waters and 37??16 mg g-1 in oxygenated fall waters. Amino acids comprised 13% to 39% of the organic carbon and 12% to 89% of the orgnaic nitrogen in these samples. Analysis of the flux results suggest that resuspension combined with lateral advection from adjacent slopes can account for up to 27% of the material in the deep traps when the estuary was well-mixed and unstratified. When the estuary was stratified in late summer, the amino acid carbon produced by primary productivity in the euphotic zone decreased by 85% (86% for total organic carbon) at the pycnocline at 6 m depth, leaving up to 15% of the vertical organic flux available for benthic sediment deposition. ?? 1993 Estuarine Research Federation.

  5. Recovery of sterols as fatty acid steryl esters from waste material after purification of tocopherols.

    PubMed

    Nagao, Toshihiro; Hirota, Yoshinori; Watanabe, Yomi; Kobayashi, Takashi; Kishimoto, Noriaki; Fujita, Tokio; Kitano, Motohiro; Shimada, Yuji

    2004-08-01

    Tocopherols are purified industrially from soybean oil deodorizer distillate by a process comprising distillation and ethanol fractionation. The waste material after ethanol fractionation (TC waste) contains 75% sterols, but a purification process has not yet been developed. We thus attempted to purify sterols by a process including a lipase-catalyzed reaction. Candida rugosa lipase efficiently esterified sterols in TC waste with oleic acid (OA). After studying several factors affecting esterification, the reaction conditions were determined as follows: ratio of TC waste/OA, 1:2 (wt/wt); water content, 30%; amount of lipase, 120 U/g-reaction mixture; temperature, 40 degrees C. Under these conditions, the degree of esterification reached 82.7% after 24 h. FA steryl esters (steryl esters) in the oil layer were purified successfully by short-path distillation (purity, 94.9%; recovery, 73.1%). When sterols in TC waste were esterified with FFA originating from olive, soybean, rapeseed, safflower, sunflower, and linseed oils, the FA compositions of the steryl esters differed somewhat from those of the original oils: The content of saturated FA was lower and that of unsaturated FA was higher. The m.p. of the steryl esters synthesized (21.7-36.5 degrees C) were remarkably low compared with those of the steryl esters purified from high-b.p. soybean oil deodorizer distillate substances (56.5 degrees C; JAOCS 80, 341-346, 2003). The low-m.p. steryl esters were soluble in rapeseed oil even at a final concentration of 10%. PMID:15638248

  6. [Analysis of volcanic-ash-based insoluble ingredients of facial cleansers].

    PubMed

    Ikarashi, Yoshiaki; Uchino, Tadashi; Nishimura, Tetsuji

    2011-01-01

    The substance termed "Shirasu balloons", produced by the heat treatment of volcanic silicates, is in the form of hollow glass microspheres. Recently, this substance has gained popularity as an ingredient of facial cleansers currently available in the market, because it lends a refreshing and smooth feeling after use. However, reports of eye injury after use of a facial cleanser containing a substance made from volcanic ashes are on the rise. We presumed that the shape and size of these volcanic-ash-based ingredients would be the cause of such injuries. Therefore, in this study, we first developed a method for extracting water-insoluble ingredients such as "Shirasu balloons" from the facial cleansers, and then, we examined their shapes and sizes. The insoluble ingredients extracted from the cleansers were mainly those derived from volcanic silicates. A part of the ingredients remained in the form of glass microspheres, but for the most part, the ingredients were present in various forms, such as fragments of broken glass. Some of the fragments were larger than 75 microm in length. Foreign objects having a certain hardness, shape, and size (e.g., size greater than 75 microm) can possibly cause eye injury. We further examined insoluble ingredients of facial scrubs, such as artificial mineral complexes, mud, charcoal, and polymers, except for volcanic-silicate-based ingredients. The amounts of insoluble ingredients extracted from these scrubs were small and did not have a sharp edge. Some scrubs had ingredients with particles larger than 75 microm in size, but their specific gravities were small and their hardness values were much lower than those of glass microspheres of ingredients such as "Shirasu balloons". Because the fragments of glass microspheres can possibly cause eye injury, the facial cleansers containing large insoluble ingredients derived from volcanic ashes should be avoided to use around eyes. PMID:22259848

  7. Tau in Alzheimer's disease and Down's syndrome is insoluble and abnormally phosphorylated.

    PubMed Central

    Hanger, D P; Brion, J P; Gallo, J M; Cairns, N J; Luthert, P J; Anderton, B H

    1991-01-01

    Some investigators have described the presence in Alzheimer's disease brain extracts of several abnormal forms of the microtubule-associated protein tau, based on their unusual mobility in SDS/PAGE. It has been proposed that these abnormal forms of tau may be the result of aberrant tau phosphorylation. In this study we show that tau in extracts of Alzheimer's disease brain can be separated into two fractions based upon its solubility (100,000 g x 1 h supernatant) in non-denaturing conditions (100 mM-Mes, pH 6.5, 0.5 mM-MgCl2, 1 mM-EGTA and 1 M-NaCl). The tau isoforms with decreased mobility in SDS/PAGE are predominantly in an insoluble fraction, whereas the soluble tau is indistinguishable by its mobility in SDS/PAGE from tau in soluble extracts of control brain. Insoluble tau displaying abnormal mobility on SDS/PAGE was only found in Alzheimer and adult Down's syndrome brains and was absent from the brains of age-matched controls and from foetal and infant Down's syndrome brains. There was a good correlation between the presence of insoluble tau in brain extracts and the abundance of neurofibrillary tangles and senile neuritic plaques. The monoclonal antibody Tau. 1 stained insoluble tau on Western blots only after treatment of the nitrocellulose transfers with alkaline phosphatase, implying that this insoluble tau is in a particular state of phosphorylation. We conclude that, in Alzheimer's disease, a fraction of tau has a modified phosphorylation state and a decreased solubility; these modifications may precede formation of the neurofibrillary tangles characteristic of Alzheimer's disease and Down's syndrome in adults. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. PMID:1826835

  8. Cytotoxic and clastogenic effects of soluble and insoluble compounds containing hexavalent and trivalent chromium.

    PubMed Central

    Levis, A. G.; Majone, F.

    1981-01-01

    Cr(III) and Cr(VI) compounds of varying solubilities have been tested in vitro for their ability to inhibit cell growth and nucleic acid and protein syntheses in BHK cells, to induce alterations in the mitotic cycle in HEp cells, and to increase the frequency of chromosomal aberrations and sister chromatid exchanges (SCE) in CHO cells. All Cr(VI) compounds, and particularly those containing soluble Cr(VI), such as potassium dichromate and zinc yellow, differentially inhibit macromolecular syntheses in BKH cells, that of DNA being always the most affected. Among Cr(III) compounds, which generally have very low cytotoxicity, chromite is particularly active, and inhibits cell growth and DNA synthesis even more than the poorly soluble Cr(VI) compounds. Preincubation in growth medium, with or without metabolizing cell cultures, solubilizes considerable amounts of Cr(VI) from zinc yellow and chromite, but significant amounts are also obtained from the most insoluble Cr(VI) pigments. When BHK cells are treated with such preincubated solutions, reduction of soluble Cr(VI) to Cr(III) by cell metabolites is seen with all Cr(VI) compounds, accompanied by decreased cytotoxicity. The same differences between Cr(VI) and Cr(III) compounds apply to the cytotoxic effects on mitosis of HEp cells and the clastogenic effects on CHO cells. The activity of chromite, the only Cr(III) pigment capable of significantly increasing the frequency of SCE, is due to contamination with soluble Cr(VI). In contrast to the very low cytotoxicity of Cr(III), much higher chromium levels are detected in the cells incubated with soluble Cr(III) than with the same concentrations of soluble Cr(VI). 50% and 75% of chromium accumulated in the cells during treatments with Cr(VI) and Cr(III) respectively remains firmly bound to the cells, even when they are incubated for up to 48 h in normal growth medium. Chromium accumulated in the cells after treatment with Cr(III) is most probably bound to the cell

  9. Adsorption of chromate/organic-acid mixtures in aquifer materials. Technical progress report, 1 July 1990--30 June 1991

    SciTech Connect

    Fish, W.; Palmer, C.D.

    1991-07-15

    The overall objective of this project is to develop a fuller understanding of the interactions of mixtures of anionic co-contaminants with oxide-mineral surfaces. Our specific focus is on the competitive interactions of chromate and oxalic acid on ferric oxyhydroxide and on natural aquifer materials. Chromate and oxalate are of practical interest as widespread contaminants at many DOE facilities. However, these anions also are excellent model adsorbates for elucidating fundamental aspects of ionic adsorption processes, particularly with respect to organic acids.

  10. Development of a new ferulic acid certified reference material for use in clinical chemistry and pharmaceutical analysis.

    PubMed

    Yang, Dezhi; Wang, Fengfeng; Zhang, Li; Gong, Ningbo; Lv, Yang

    2015-05-01

    This study compares the results of three certified methods, namely differential scanning calorimetry (DSC), the mass balance (MB) method and coulometric titrimetry (CT), in the purity assessment of ferulic acid certified reference material (CRM). Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k) of 2 (P=95%). The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid. PMID:26579451

  11. Development of a new ferulic acid certified reference material for use in clinical chemistry and pharmaceutical analysis

    PubMed Central

    Yang, Dezhi; Wang, Fengfeng; Zhang, Li; Gong, Ningbo; Lv, Yang

    2015-01-01

    This study compares the results of three certified methods, namely differential scanning calorimetry (DSC), the mass balance (MB) method and coulometric titrimetry (CT), in the purity assessment of ferulic acid certified reference material (CRM). Purity and expanded uncertainty as determined by the three methods were respectively 99.81%, 0.16%; 99.79%, 0.16%; and 99.81%, 0.26% with, in all cases, a coverage factor (k) of 2 (P=95%). The purity results are consistent indicating that the combination of DSC, the MB method and CT provides a confident assessment of the purity of suitable CRMs like ferulic acid. PMID:26579451

  12. Preparation and characterization of humic acid-carbon hybrid materials as adsorbents for organic micro-pollutants.

    PubMed

    Radwan, Emad K; Abdel Ghafar, Hany H; Moursy, Ahmed S; Langford, Cooper H; Bedair, Ahmed H; Achari, Gopal

    2015-08-01

    The present work involves the preparation of novel adsorbent materials by the insolubilization and hybridization of humic acid (HA) with carbon. The prepared materials were characterized by N2 adsorption, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, solid-state (13)C cross polarization magic angle spinning nuclear magnetic resonance, and low-field nuclear magnetic resonance (NMR) relaxometry on wetted samples. The water solubility of these materials and the lack of effect of oxidants were also confirmed. With this background, the adsorption capacities toward phenol, 2,4,6-tricholrophenol, and atrazine were evaluated, using these as model compounds for organic micropollutants of concern in water. Experimental results show that the prepared materials are mesoporous and have a higher surface area than humic acid and even than the porous carbon in the case of carbon coating. They retain the basic features of the starting materials with lowered functional group content. Moreover, there are interesting new features. NMR relaxometry shows that equilibration of water uptake is very fast, making use in water simple. They have higher adsorption capacities than the pure materials, and they can be applied under a wide range of environmental conditions. PMID:25874433

  13. Proteomic and biochemical basis for enhanced growth yield of Enterobacter sp. LCR1 on insoluble phosphate medium.

    PubMed

    Kumar, Arvind; Rai, Lal Chand

    2015-01-01

    Proteomics and biochemical analyses were used to unravel the basis for higher growth yield of Enterobacter sp. LCR1 on insoluble phosphate medium compared to soluble. Proteomic analysis using 2-DE, MALDI-TOF/MS and LC-MS revealed the involvement of nine proteins. Down-regulation of fructose bisphosphate aldolase with decreased concentrations of glucose-6-phosphate and fructose-6-phosphate indicated diminished glycolysis. However, up-regulation of phosphoglycerate mutase, increase in the activities of 6-phosphogluconate dehydratase, 2-keto-3-deoxy-6-phosphogluconate aldolase and 6-phosphogluconate dehydrogenase suggested induction of Entner-Doudoroff and pentose phosphate pathways. These pathways generate sufficient energy from gluconic acid, which is also used for biosynthesis as indicated by up-regulation of elongation factor Tu, elongation factor G and protein disulfide isomerase. Increased reactive oxygen species (ROS) formation resulting from organic acid oxidation leads to overexpressed manganese superoxide dismutase and increased activities of catalase and ascorbate peroxidase. Thus the organism uses gluconate instead of glucose for energy, while alleviating extra ROS formation by oxidative defense enzymes. PMID:25053519

  14. Acid Precipitation Learning Materials: Science, Environmental and Social Studies, Grades 6-12.

    ERIC Educational Resources Information Center

    Hessler, Edward W.

    The major environmental problem of acid precipition is addressed through a series of activities contained in this guide for teachers of grades 6 through 12. Exercises are provided to help students learn science inquiry skills, facts, and concepts while focusing on the acid rain situation. Activities are organized by content areas. These include:…

  15. A novel sodium N-fatty acyl amino acid surfactant using silkworm pupae as stock material

    NASA Astrophysics Data System (ADS)

    Wu, Min-Hui; Wan, Liang-Ze; Zhang, Yu-Qing

    2014-03-01

    A novel sodium N-fatty acyl amino acid (SFAAA) surfactant was synthesized using pupa oil and pupa protein hydrolysates (PPH) from a waste product of the silk industry. The aliphatic acids from pupa oil were modified into N-fatty acyl chlorides by thionyl chloride (SOCl2). SFAAA was synthesized using acyl chlorides and PPH. GC-MS analysis showed fatty acids from pupa oil consist mainly of unsaturated linolenic and linoleic acids and saturated palmitic and stearic acids. SFAAA had a low critical micelle concentration, great efficiency in lowering surface tension and strong adsorption at an air/water interface. SFAAA had a high emulsifying power, as well as a high foaming power. The emulsifying power of PPH and SFAAA in an oil/water emulsion was better with ethyl acetate as the oil phase compared to n-hexane. The environment-friendly surfactant made entirely from silkworm pupae could promote sustainable development of the silk industry.

  16. A method for determining thermophysical properties of organic material in aqueous solutions: Succinic acid

    NASA Astrophysics Data System (ADS)

    Riipinen, I.; Svenningsson, B.; Bilde, M.; Gaman, A.; Lehtinen, K. E. J.; Kulmala, M.

    2006-12-01

    A method for determining evaporation rates and thermodynamic properties of aqueous solution droplets is introduced. The method combines evaporation rate measurements using modified TDMA technique with data evaluation using an accurate evaporation model. The first set of data has been collected and evaluated for succinic acid aqueous solution droplets. Evaporation rates of succinic acid solution droplets have been measured using a TDMA system at controlled relative humidity (65%) and temperature (298 K). A temperature-dependent expression for the saturation vapour pressure of pure liquid phase succinic acid at atmospheric temperatures has been derived by analysing the evaporation rate data with a numerical model. The obtained saturation vapour pressure of liquid phase succinic acid is ln( p) = 118.41 - 16204.8/ T - 12.452ln( T). The vapour pressure is in unit of Pascal and the temperature in Kelvin. A linear expression for the enthalpy of vaporization for liquid state succinic acid is also presented. According to the results presented in the following, a literature expression for the vapour pressure of liquid phase succinic acid defined for temperatures higher than 461 K [Yaws, C.L., 2003. Yaws' Handbook of Thermodynamic and Physical Properties of Chemical Compounds, Knovel] can be extrapolated to atmospheric temperatures with very good accuracy. The results also suggest that at 298 K the mass accommodation coefficient of succinic acid is unity or very close to unity.

  17. Behavior of transplutonium elements on ion-exchange materials in mixed aqueous-organic solutions of mineral acids

    SciTech Connect

    Guseva, L.I.; Tikhomirov, G.S.; Stepushkina, V.V.

    1987-03-01

    Systematic studies are reported on the behavior of transplutonium elements (TPE) on cation-exchange and anion-exchange materials in mixed aqueous-organic solutions of mineral acids (HClO/sub 4/, HCl, HNO/sub 3/, H/sub 2/SO/sub 4/, H/sub 3/PO/sub 4/) as affected by solution composition, nature of acid, and nature of organic solvent. With all these acids, replacing most of the water by alcohol increases the TPE uptake on the ion exchangers, and the effect occurs for the cation exchangers at lower contents of the organic component. Optimum conditions have been identified for concentrating and separating TPE from numerous elements. The most effective system consists of anion exchanger with HNO/sub 3/ and alcohol.

  18. Fabrication of Li2TiO3 pebbles using PVA-boric acid reaction for solid breeding materials

    NASA Astrophysics Data System (ADS)

    Park, Yi-Hyun; Cho, Seungyon; Ahn, Mu-Young

    2014-12-01

    Lithium metatitanate (Li2TiO3) is a candidate breeding material of the Helium Cooled Ceramic Reflector (HCCR) Test Blanket Module (TBM). The breeding material is used in pebble-bed form to reduce the uncertainty of the interface thermal conductance. In this study, Li2TiO3 pebbles were successfully fabricated by the slurry droplet wetting method using the cross-linking reaction between polyvinyl alcohol (PVA) and boric acid. The effects of fabrication parameters on the shaping of Li2TiO3 green body were investigated. In addition, the basic characteristics of the sintered pebble were also evaluated. The shape of Li2TiO3 green bodies was affected by slurry viscosity, PVA content and boric acid content. The grain size and average crush load of sintered Li2TiO3 pebble were controlled by the sintering time. The boron was completely removed during the final sintering process.

  19. Reduction of hydrogen peroxide stress derived from fatty acid beta-oxidation improves fatty acid utilization in Escherichia coli.

    PubMed

    Doi, Hidetaka; Hoshino, Yasushi; Nakase, Kentaro; Usuda, Yoshihiro

    2014-01-01

    Fatty acids are a promising raw material for substance production because of their highly reduced and anhydrous nature, which can provide higher fermentation yields than sugars. However, they are insoluble in water and are poorly utilized by microbes in industrial fermentation production. We used fatty acids as raw materials for L-lysine fermentation by emulsification and improved the limited fatty acid-utilization ability of Escherichia coli. We obtained a fatty acid-utilizing mutant strain by laboratory evolution and demonstrated that it expressed lower levels of an oxidative-stress marker than wild type. The intracellular hydrogen peroxide (H₂O₂) concentration of a fatty acid-utilizing wild-type E. coli strain was higher than that of a glucose-utilizing wild-type E. coli strain. The novel mutation rpsA(D210Y) identified in our fatty acid-utilizing mutant strain enabled us to promote cell growth, fatty-acid utilization, and L-lysine production from fatty acid. Introduction of this rpsA(D210Y) mutation into a wild-type strain resulted in lower H₂O₂ concentrations. The overexpression of superoxide dismutase (sodA) increased intracellular H₂O₂ concentrations and inhibited E. coli fatty-acid utilization, whereas overexpression of an oxidative-stress regulator (oxyS) decreased intracellular H₂O₂ concentrations and promoted E. coli fatty acid utilization and L-lysine production. Addition of the reactive oxygen species (ROS) scavenger thiourea promoted L-lysine production from fatty acids and decreased intracellular H₂O₂ concentrations. Among the ROS generated by fatty-acid β-oxidation, H₂O₂ critically affected E. coli growth and L-lysine production. This indicates that the regression of ROS stress promotes fatty acid utilization, which is beneficial for fatty acids used as raw materials in industrial production. PMID:24169950

  20. Use of wastewater sludge as a raw material for production of L-lactic acid

    SciTech Connect

    Nakasaki, Kiyohiko; Akakura, Naoki; Adachi, Tomohiko; Akiyama, Tetsuo

    1999-01-01

    This study utilizes wastewater sludges to produce L-lactic acid, a precursor of biodegradable plastic. The high concentrations of cellulose contained in the sludge, derived from a paper manufacturing facility, have been found to be convertible to L-lactic acid at a rate as high as 6.91 g/L. To achieve such a high conversion rate, the sludge must be pretreated with cellulase. This pretreatment includes inoculation of the sludge with lactic acid bacteria, strain LA1, after the sludge has been subjected to enzymatic hydrolysis.

  1. Surface acid-base characteristics of fiber materials by contact angle measurements

    SciTech Connect

    Mao Youan . Dept. of Materials Science and Applied Chemistry)

    1993-11-05

    Contact angle measurements were used to study the surface acid-base characteristics of treated and untreated carbon fibers, and of treated and untreated silicon carbide fibers. It has been shown that, when untreated the surfaces of these two fibers exhibits amphoteric, but the base character is dominant. After oxidization in a liquid phase, the surface acid character of the carbon fibers changes little, whereas the base character becomes much stronger. The treatment, with boiling-concentrated HNO[sub 3] for three hours and the sintering treatment in air at 500 C. for eight hours, has little effect on the surface acid-base characteristics of the silicon carbide fibers.

  2. Comparative Evaluation of Shear Bond Strength of Luting Cements to Different Core Buildup Materials in Lactic Acid Buffer Solution

    PubMed Central

    Patil, Siddharam M.; Desai, Raviraj G.; Arabbi, Kashinath C.; Prakash, Ved

    2015-01-01

    Aim and Objectives The core buildup material is used to restore badly broken down tooth to provide better retention for fixed restorations. The shear bond strength of a luting agent to core buildup is one of the crucial factors in the success of the cast restoration. The aim of this invitro study was to evaluate and compare the shear bond strength of luting cements with different core buildup materials in lactic acid buffer solution. Materials and Methods Two luting cements {Traditional Glass Ionomer luting cement (GIC) and Resin Modified Glass Ionomer luting cement (RMGIC)} and five core buildup materials {Silver Amalgam, Glass ionomer (GI), Glass Ionomer Silver Reinforced (GI Silver reinforced), Composite Resin and Resin Modified Glass Ionomer(RMGIC)} were selected for this study. Total 100 specimens were prepared with 20 specimens for each core buildup material using a stainless steel split metal die. Out of these 20 specimens, 10 specimens were bonded with each luting cement. All the bonded specimens were stored at 370c in a 0.01M lactic acid buffer solution at a pH of 4 for 7days. Shear bond strength was determined using a Universal Testing Machine at a cross head speed of 0.5mm/min. The peak load at fracture was recorded and shear bond strength was calculated. The data was statistically analysed using Two-way ANOVA followed by HOLM-SIDAK method for pair wise comparison at significance level of p<0.05. Results Two-Way ANOVA showed significant differences in bond strength of the luting cements (p<0.05) and core materials (p<0.05) and the interactions (p<0.05). Pairwise comparison of luting cements by HOLM-SIDAK test, showed that the RMGIC luting cement had higher shear bond strength values than Traditional GIC luting cement for all the core buildup materials. RMGIC core material showed higher bond strength values followed by Composite resin, GI silver reinforced, GI and silver amalgam core materials for both the luting agents. Conclusion Shear bond strength of

  3. High-sensitivity ascorbic acid sensor using graphene sheet/graphene nanoribbon hybrid material as an enhanced electrochemical sensing platform.

    PubMed

    Lavanya, J; Gomathi, N

    2015-11-01

    A novel electrode material of graphene sheet/graphene nanoribbon (GS/GNR) hybrid material was developed by incorporating graphene nanoribbons into graphene nanosheets through simultaneous chemical reduction of graphene oxide sheets and graphene oxide ribbons. The structure and properties of synthesized GS/GNR were characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, Brunauer Emmett Teller measurements and Fourier transform infrared spectroscopy. This work compares the electro catalytic performance of the GS/GNR, chemically reduced graphene oxide sheets (CRGOS) and GS/carbon nanotube (CNT) by modifying the glassy carbon electrode (GCE) using ascorbic acid (AA) as analyte. The electrochemical impedance spectroscopy revealed that the charge transfer resistance of GS/GNR modified electrode was less than that of CRGOS modified electrode and bare GCE. The cyclic voltammetric sensing of GS/GNR modified electrode towards AA was negatively shifted (0.08 V) compared to CRGOS, GS/CNT modified electrode and bare GCE (0.222, 0.150 and 0.666 V). This catalytic oxidation allows an amperometric detection of AA with a detection limit of 230 nM and sensitivity of 22 nA μM(-1) cm(-2). GS/GNR modified GCE exhibited a high selectivity for ascorbic acid in the presence of other interferents like dopamine, uric acid and citric acid. PMID:26452874

  4. Electrochemical synthesis of adiponitrile from the renewable raw material glutamic acid.

    PubMed

    Dai, Jian-Jun; Huang, Yao-Bing; Fang, Chi; Guo, Qing-Xiang; Fu, Yao

    2012-04-01

    Current affairs: Adiponitrile, used to produce nylon 6.6, is prepared from the renewable compound glutamic acid by an electrochemical route, involving electro-oxidative decarboxylation and Kolbe coupling reactions. The new route is an example of the use of glutamic acid as a versatile substrate in the transformation of biomass into chemicals. Also, it highlights the use of electrochemical methods in biomass conversion. PMID:22441826

  5. A technique for obtaining matrix-assisted laser desorption/ionization time-of-flight mass spectra of poorly soluble and insoluble aromatic polyamides.

    PubMed

    Gies, Anthony P; Nonidez, William K

    2004-04-01

    Wet grinding methods for obtaining matrix-assisted laser desorption/ionization time-of-flight mass spectra of poorly soluble and insoluble low molecular mass oligomers (<4600 Da) of Nomex and Kevlar are described. Optimum conditions for sample preparation are given along with a detailed analysis of the spectra obtained. Two matrix materials were employed in this analysis, 1,8-dihydroxyanthrone (dithranol) and 3-aminoquinoline with potassium trifluoroacetate used as the cationizing agent. The spectra obtained in this study are sensitive to the matrix, molar mixing ratios of matrix/polymer/cationizing agent, and the sample preparation method. PMID:15053662

  6. Evaluation of the acid properties of porous zirconium-doped and undoped silica materials

    NASA Astrophysics Data System (ADS)

    Fuentes-Perujo, D.; Santamaría-González, J.; Mérida-Robles, J.; Rodríguez-Castellón, E.; Jiménez-López, A.; Maireles-Torres, P.; Moreno-Tost, R.; Mariscal, R.

    2006-07-01

    A series of porous silica and Zr-doped silica molecular sieves, belonging to the MCM-41 and MSU families, were prepared and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and N 2 adsorption at 77 K. Their acid properties have been evaluated by NH 3-TPD, adsorption of pyridine and deuterated acetonitrile coupled to FT-IR spectroscopy and the catalytic tests of isopropanol decomposition and isomerization of 1-butene. The acidity of purely siliceous solids were, in all cases, very low, while the incorporation of Zr(IV) into the siliceous framework produced an enhancement of the acidity. The adsorption of basic probe molecules and the catalytic behaviour revealed that Zr-doped MSU-type silica was more acidic than the analogous Zr-MCM-41 solid, with a similar Zr content. This high acidity observed in the case of Zr-doped silica samples is due to the presence of surface zirconium atoms with a low coordination, mainly creating Lewis acid sites.

  7. A Pd8 Tetrafacial Molecular Barrel as Carrier for Water Insoluble Fluorophore.

    PubMed

    Roy, Bijan; Ghosh, Aloke Kumar; Srivastava, Shubhi; D'Silva, Patrick; Mukherjee, Partha Sarathi

    2015-09-23

    A new carbazole-based tetraimidazole ligand 1,3,6,8-tetra(1H-imidazol-1-yl)-9-methyl-9H-carbazole (L) has been synthesized. The unsymmetrical nature of L as well as the rotational freedom of imidazole donor moieties around C-N bond make it a special building unit, which upon treatment with cis-(tmeda)Pd(NO3)2 produced an unprecedented single linkage-isomeric Pd8 tetrafacial molecular nanobarrel (PSMBR-1) [tmeda = N,N,N',N'-tetramethylethane-1,2-diamine]. Unlike closed architectures, open barrel architecture of water-soluble PSMBR-1 makes it an ideal host for some water insoluble polyaromatic hydrocarbons in aqueous medium; one such inclusion complex coronene⊂PSMBR-1 was characterized by X-ray diffraction study. Moreover, the potential application of PSMBR-1 as carrier in aqueous medium for the transportation of water insoluble fluorophore (perylene) for live cell imaging is explored. PMID:26340646

  8. Antioxidants and bioactivities of free, esterified and insoluble-bound phenolics from berry seed meals.

    PubMed

    Ayoub, Maha; de Camargo, Adriano Costa; Shahidi, Fereidoon

    2016-04-15

    Phenolic compounds present in the free, soluble ester and insoluble-bound forms of blackberry, black raspberry and blueberry were identified and quantified using high-performance liquid chromatography-diode array detection-electrospray ionisation multistage mass spectrometry. The total phenolics, scavenging activity against hydroxyl and peroxyl radicals, the reducing power and chelating capacity were, in general, in the decreasing order of blackberry>black raspberry>blueberry. Amongst fractions, the order was insoluble-bound>esterified>free. These trends were the same as those found against copper-induced LDL-cholesterol oxidation and supercoiled plasmid DNA strand breakage inhibition induced by both peroxyl and hydroxyl radicals. Extracts were found to contain various levels of phenolic compounds that were specific to each berry seed meal type. Berry seed meals should be considered as a good source of phenolics with potential health benefits. Their full exploitation may be helpful for the food industry and consumers. PMID:26616944

  9. Total, insoluble and soluble dietary fibre intake in relation to blood pressure: the INTERMAP Study.

    PubMed

    Aljuraiban, Ghadeer S; Griep, Linda M Oude; Griep, Linda M O; Chan, Queenie; Daviglus, Martha L; Stamler, Jeremiah; Van Horn, Linda; Elliott, Paul; Frost, Gary S

    2015-11-14

    Prospective cohort studies have shown inverse associations between fibre intake and CVD, possibly mediated by blood pressure (BP). However, little is known about the impact of types of fibre on BP. We examined cross-sectional associations with BP of total, insoluble and soluble fibre intakes. Data were used from the INTERnational study on MAcro/micronutrients and blood Pressure (INTERMAP) study, including 2195 men and women aged between 40 and 59 years from the USA. During four visits, eight BP, four 24 h dietary recalls and two 24 h urine samples were collected. Linear regression models adjusted for lifestyle and dietary confounders to estimate BP differences per 2 sd higher intakes of total and individual types of fibre were calculated. After multivariable adjustment, total fibre intake higher by 6·8 g/4184 kJ (6·8 g/1000 kcal) was associated with a 1·69 mmHg lower systolic blood pressure (SBP; 95% CI -2·97, -0·41) and attenuated to -1·01 mmHg (95% CI -2·35, 0·34) after adjustment for urinary K. Insoluble fibre intake higher by 4·6 g/4184 kJ (4·6 g/1000 kcal) was associated with a 1·81 mmHg lower SBP (95% CI -3·65, 0·04), additionally adjusted for soluble fibre and urinary K excretion, whereas soluble fibre was not associated with BP. Raw fruit was the main source of total and insoluble fibre, followed by whole grains and vegetables. In conclusion, higher intakes of fibre, especially insoluble, may contribute to lower BP, independent of nutrients associated with higher intakes of fibre-rich foods. PMID:26328746

  10. Effect of components of resilient denture-lining materials on the growth, acid production and colonization of Candida albicans.

    PubMed

    Nikawa, H; Yamamoto, T; Hamada, T

    1995-11-01

    Variation in the components of soft lining materials, i.e. the size of polymer particles, the ethyl alcohol content of the liquids and the type of plasticizer, were investigated with respect to their effects on the growth and colonization of Candida albicans. Inhibitory effects on fungal growth and/or acid production were found to vary depending upon the components of soft lining materials. In particular, two plasticizers, benzyl benzoate (BB) and benzyl salicylate (BS), significantly decreased the growth rate, whereas the size of polymer particle had little effect on fungal growth. Ethyl alcohol content of liquid significantly affected the fungal growth and/or acid production depending upon the plasticizer used. For instance, in the case of BS, the antifungal effect was related to ethyl alcohol contents, whereas a reverse effect was observed with benzyl n-butyl phthalate (BBP). Further examination using scanning electron microscopy revealed that Candida blastospores colonized lining materials in the following two ways depending on the plasticizers used. On the BS and dibutyl phthalate (DBP) specimen, the blastospore of this yeast associated loosely, whereas, in the case of BB, BBP and butyl phthalyl butyl glycorate (BPBG), fungal blastospore tightly and invasively colonized onto the specimens. These results clearly demonstrated a relationship between components of soft lining materials and fungal growth and colonization. PMID:8558354

  11. Insoluble drug delivery strategies: review of recent advances and business prospects

    PubMed Central

    Kalepu, Sandeep; Nekkanti, Vijaykumar

    2015-01-01

    The emerging trends in the combinatorial chemistry and drug design have led to the development of drug candidates with greater lipophilicity, high molecular weight and poor water solubility. Majority of the failures in new drug development have been attributed to poor water solubility of the drug. Issues associated with poor solubility can lead to low bioavailability resulting in suboptimal drug delivery. About 40% of drugs with market approval and nearly 90% of molecules in the discovery pipeline are poorly water-soluble. With the advent of various insoluble drug delivery technologies, the challenge to formulate poorly water soluble drugs could be achieved. Numerous drugs associated with poor solubility and low bioavailabilities have been formulated into successful drug products. Several marketed drugs were reformulated to improve efficacy, safety and patient compliance. In order to gain marketing exclusivity and patent protection for such products, revitalization of poorly soluble drugs using insoluble drug delivery technologies have been successfully adopted by many pharmaceutical companies. This review covers the recent advances in the field of insoluble drug delivery and business prospects. PMID:26579474

  12. Effect of homogenization and ultrasonication on the physical properties of insoluble wheat bran fibres

    NASA Astrophysics Data System (ADS)

    Hu, Ran; Zhang, Min; Adhikari, Benu; Liu, Yaping

    2015-10-01

    Wheat bran is rich in dietary fibre and its annual output is abundant, but underutilized. Insoluble dietary fibre often influences food quality negatively; therefore, how to improve the physical and chemical properties of insoluble dietary fibre of wheat bran for post processing is a challenge. Insoluble dietary fibre was obtained from wheat bran and micronized using high-pressure homogenization, high-intensity sonication, and a combination of these two methods. The high-pressure homogenization and high-pressure homogenization+high-intensity sonication treatments significantly (p<0.05) improved the solubility, swelling, water-holding, oil-holding, and cation exchange capacities. The improvement of the above properties by high-intensity sonication alone was marginal. In most cases, the high-pressure homogenization process was as good as the high-pressure homogenization+high-intensity sonication process in improving the above-mentioned properties; hence, the contribution of high-`intensity sonication in the high-pressure homogenization+high-intensity sonication process was minimal. The best results show that the minimum particle size of wheat bran can reach 9 μm, and the solubility, swelling, water-holding, oil-holding, cation exchange capacities change significantly.

  13. Insoluble drug delivery strategies: review of recent advances and business prospects.

    PubMed

    Kalepu, Sandeep; Nekkanti, Vijaykumar

    2015-09-01

    The emerging trends in the combinatorial chemistry and drug design have led to the development of drug candidates with greater lipophilicity, high molecular weight and poor water solubility. Majority of the failures in new drug development have been attributed to poor water solubility of the drug. Issues associated with poor solubility can lead to low bioavailability resulting in suboptimal drug delivery. About 40% of drugs with market approval and nearly 90% of molecules in the discovery pipeline are poorly water-soluble. With the advent of various insoluble drug delivery technologies, the challenge to formulate poorly water soluble drugs could be achieved. Numerous drugs associated with poor solubility and low bioavailabilities have been formulated into successful drug products. Several marketed drugs were reformulated to improve efficacy, safety and patient compliance. In order to gain marketing exclusivity and patent protection for such products, revitalization of poorly soluble drugs using insoluble drug delivery technologies have been successfully adopted by many pharmaceutical companies. This review covers the recent advances in the field of insoluble drug delivery and business prospects. PMID:26579474

  14. Knockdown of versican 1 blocks cigarette-induced loss of insoluble elastin in human lung fibroblasts.

    PubMed

    Xu, Lu-lu; Lu, Yun-tao; Zhang, Jing; Wu, Lian; Merrilees, Mervyn J; Qu, Jie-ming

    2015-08-15

    COPD lung is characterized by loss of alveolar elastic fibers and an increase in the chondroitin sulfate (CS) matrix proteoglycan versican V1 (V1). V1 is a known inhibitor of elastic fiber deposition and this study investigates the effects of knockdown of V1, and add-back of CS, on CCL-210 lung fibroblasts treated with cigarette smoke extract (CSE) as a model for COPD. CSE inhibited fibroblast proliferation, viability, tropoelastin synthesis, and elastin deposition, and increased V1 synthesis and secretion. V1 siRNA decreased V1 and constituent CS, did not affect tropoelastin production, but blocked the CSE-induced loss in insoluble elastin. Exogenous CS reduced insoluble elastin, even in the presence of V1 siRNA. These findings confirm that V1 and CS impair the assembly of tropoelastin monomers into insoluble fibers, and further demonstrate that specific knockdown of V1 alleviates the impaired assembly of elastin seen in cultures of pulmonary fibroblasts exposed to CSE, indicating a regulatory role for this protein in the pathophysiology of COPD. PMID:25999281

  15. Effect of insoluble extracellular matrix molecules on Fas expression in epithelial cells.

    PubMed

    Fine, A; Miranda, K; Farmer, S R; Anderson, N L

    1998-03-01

    Fas, which functions to initiate a signal causing apoptosis, is expressed in epithelia, thus, suggesting a role in controlling cell number during states of cell and matrix turnover. In view of this, we hypothesized that cell-matrix interactions may be an important determinant of Fas expression in epithelial cells. To investigate this, we examined the effect of insoluble extracellular matrix molecules on Fas expression in murine lung epithelial (MLE) cells, a transformed mouse lung epithelial cell line. We report that 1) insoluble extracellular matrices increased Fas mRNA in a time and concentration-dependent manner; 2) induced increases in Fas mRNA were associated with concomitantly increased Fas protein; and 3) nonspecific adherence to a polylysine substrate did not induce Fas mRNA. Consistent with these findings, Fas-induced apoptosis was significantly enhanced in cultures plated on type IV collagen. Employing rat hepatocytes, we confirmed that the insoluble extracellular matrix also increases Fas expression in primary epithelial cells. By amplifying Fas-mediated apoptosis, these data suggest a mechanism whereby the extracellular matrix regulates the fate of specific epithelial cell populations. PMID:9462690

  16. Sequential Extraction of Soluble and Insoluble Alpha-Synuclein from Parkinsonian Brains

    PubMed Central

    Bandopadhyay, Rina

    2016-01-01

    Alpha-synuclein (α-syn) protein is abundantly expressed mainly within neurons, and exists in a number of different forms - monomers, tetramers, oligomers and fibrils. During disease, α-syn undergoes conformational changes to form oligomers and high molecular weight aggregates that tend to make the protein more insoluble. Abnormally aggregated α-syn is a neuropathological feature of Parkinson's disease (PD), dementia with Lewy bodies (DLB) and multiple system atrophy (MSA). Biochemical characterization and analysis of insoluble α-syn using buffers with increasing detergent strength and high-speed ultracentrifugation provides a powerful tool to determine the development of α-syn pathology associated with disease progression. This protocol describes the isolation of increasingly insoluble/aggregated α-syn from post-mortem human brain tissue. This methodology can be adapted with modifications to studies of normal and abnormal α-syn biology in transgenic animal models harbouring different α-syn mutations as well as in other neurodegenerative diseases that feature aberrant fibrillar deposits of proteins related to their respective pathologies. PMID:26780369

  17. Significant formation of water-insoluble secondary organic aerosols in semi-arid urban environment

    NASA Astrophysics Data System (ADS)

    Favez, Olivier; Sciare, Jean; Cachier, Hélène; Alfaro, Stéphane C.; Abdelwahab, Magdy M.

    2008-08-01

    Diurnal variations of submicron elemental carbon (EC), water-soluble organic carbon (WSOC) and water-insoluble organic carbon (WIOC) were investigated at an urban background site in Cairo (Egypt) from 23 March to 14 April 2005. Well-marked diurnal patterns, with minima during the traffic-influenced morning period (6:00-9:00) and maxima during the intense photochemical period (12:00-15:00), were observed for the WSOC/EC ratio and, more surprisingly, for the WIOC/EC ratio. Such diurnal variations suggest significant formation of both water-soluble and water-insoluble secondary organic aerosols during the afternoon. Applying the EC-tracer method, freshly-formed secondary organic carbon (fresh SOC) was found to possibly account for more than 50% of OC concentrations measured during the 12:00-15:00 period, and this fresh SOC was calculated to be mainly (~60%) composed of water-insoluble species. The latter (unexpected) result could be due to low ambient relative humidity as well as to the importance of anthropogenic volatile organic compounds in Cairo.

  18. Enrichment of By-Product Materials from Steel Pickling Acid Regeneration Plants (TRP 9942)

    SciTech Connect

    Lu Swan, Delta Ferrites LLC

    2009-09-30

    A new process for manufacturing an enriched, iron-based product (strontium hexaferrite) in existing steel pickling acid regeneration facilities was evaluated. Process enhancements and equipment additions were made to an existing acid regeneration plant to develop and demonstrate (via pilot scale testing and partial-capacity production trials) the viability of a patented method to produce strontium-based compounds that, when mixed with steel pickling acid and roasted, would result in a strontium hexaferrite powder precursor which could then be subjected to further heat treatment in an atmosphere that promotes rapid, relatively low-temperature formation of discrete strontium hexaferrite magnetic domains yielding an enriched iron-based product, strontium hexaferrite, that can be used in manufacturing hard ferrite magnets.

  19. Using Enviro-Pod low altitude imagery to inventory building surface materials for an acid rain study - A Baltimore example

    NASA Technical Reports Server (NTRS)

    Ellefsen, Richard; Coffland, Bruce

    1987-01-01

    Low altitude, oblique and vertical color photography taken from EPA's Enviro-Pod Ka 85 camera system has provided the data for taking an inventory of building surface materials in a test area of downtown Baltimore. Photography was acquired from a gridded flight plan to provide views of all sides of buildings. Color, texture, and linear detail are employed in the photo interpretation aided by contextual reference to a classification of building construction type developed in an earlier study. The work could potentially support a materials inventory initiated by the National Acid Precipitation Assessment Program (NAPAP) by scientists from EPA, Geological Survey, and the Department of Energy. Initial results show the method to be viable. Discrete surface materials such as brick, both bare and painted, stone, and metal are identified.

  20. Reversible collapse of insoluble monolayers: new insights on the influence of the anisotropic line tension of the domain.

    PubMed

    González-Delgado, Antonio M; Pérez-Morales, Marta; Giner-Casares, Juan J; Muñoz, Eulogia; Martín-Romero, María T; Camacho, Luis

    2009-10-01

    In this paper, we study the collapse of a mixed insoluble monolayer formed by a cationic matrix, dioctadecyl-dimethylammonium bromide (DOMA), and a tetra-anionic porphyrin, tetrakis(4-sulfonatophenyl)porphyrin (TSPP), in a molar ratio TSPP/DOMA = 1:4. During the collapse of this system, we visualized the formation of circular domains consisting exclusively of trilayer, although the domains coalescence was not observed. The coexistence of trilayer and monolayer at the final step of the collapse cannot be interpreted exclusively in terms of a thermodynamic phase equilibrium, intervening as an additional factor the anisotropic line tension of the domain. A high line tension implies a high resistance to the domain deformation, and the anisotropy of the line tension implies the lack of coalescence between these domains, which has been experimentally observed by Brewster angle microscopy for us. Under these circumstances, the domains of collapsed material could enclose monolayer regions where the local surface pressure drops thus stopping the collapse process. The collapse of the TSPP/DOMA system is reversible, that is, the return of the three-dimensional material to the monolayer fits into a simple kinetics according to the nucleation-growth-collision theory. As for the collapse, the reverse process is also affected by the line tension of the domains. This paper relates the high line tension and the anisotropic line tension of a given domains with the reversible nature of the collapse process. PMID:19791820

  1. Determination of Perfluorinated Alkyl Acid Concentrations in Biological Standard Reference Materials

    EPA Science Inventory

    Standard reference materials (SRMs) are homogeneous, well-characterized materials used to validate measurements and improve the quality of analytical data. The National Institute of Standards and Technology (NIST) has a wide range of SRMs that have mass fraction values assigned ...

  2. Synthesis and characterization of an insoluble polymer based on polyamidoamine: applications for the decontamination of metals in aqueous systems.

    PubMed

    Valdés, Oscar; Vergara, Claudia E; Camarada, Maria B; Carrasco-Sánchez, Veronica; Nachtigall, Fabiane M; Tapia, Jaime; Fischer, Rainer; González-Nilo, F D; Santos, Leonardo S

    2015-01-01

    We present a novel, insoluble, low-generation polyamidoamine (PAMAM)-based polymer. The monomer and polymer were characterized by fourier transform infrared spectroscopy, electrospray ionization mass spectrometry and thermogravimetric measurement, revealing that G0 acryloyl-terminated PAMAM were synthesized and polymerized using ammonium persulfate as an initiator, producing a high-density PAMAM derivative (PAMAM-HD). PAMAM-HD was tested for its ability to remove Na(I), K(I), Ca(II), Mg(II), Cu(II), Mn(II), Cd(II), Pb(II) and Zn(II) ions from acidic, neutral and basic aqueous solutions. PAMAM-HD efficiently removed metals ions from all three solutions. The greatest absorption efficiency at neutral pH was observed against Cu(II), Cd(II) and Pb(II), and the experimental data were supported by the calculated Kd values. Our data could have a significant impact on water purification by providing an inexpensive and efficient polymer for the removal of metal ions. PMID:25304521

  3. Morphological characterization of LiFePO 4/C composite cathode materials synthesized via a carboxylic acid route

    NASA Astrophysics Data System (ADS)

    Fey, George Ting-Kuo; Lu, Tung-Lin

    A new type of LiFePO 4/C composite surrounded by a web containing both amorphous and crystalline carbon phases was synthesized by incorporating malonic acid as a carbon source using a high temperature solid-state method. SEM, TEM/SAED/EDS and HRTEM were used to analyze surface morphology and confirmed for the first time that crystalline carbon was present in LiFePO 4/C composites. The composite was effective in enhancing the electrochemical properties such as capacity and rate capability, because its active component consists of nanometer-sized particles containing pores with a wide range of sizes. An EDS elemental map showed that carbon was uniformly distributed on the surface of the composite crystalline particles. TEM/EDS results clearly show a dark region that is LiFePO 4 with a trace of carbon and a gray region that is carbon only. To evaluate the materials' electrochemical properties, galvanostatic cycling and conductivity measurements were performed. The best cell performance was delivered by the material coated with 60 wt.% malonic acid, which delivered first cycle discharge capacity of 149 mAh g -1 at a C/5 rate and sustained 222 cycles at 80% of capacity retention. When carboxylic acid was used as a carbon source to produce LiFePO 4, overall conductivity increased from 10 -5 to 10 -4 S cm -1, since particle growth was prevented during the final sintering process.

  4. Characterization and catalytic performance of heteropoly acid H4SiW12O40 supported on nanoporous materials.

    PubMed

    Chen, Fengxi; Ma, Jiping; Dong, Zhibing; Liu, Rong

    2014-09-01

    Heteropoly acid H4SiW12O40 (SiW) has been supported on different nanoporous materials and characterized by powder X-ray diffraction (XRD), FTIR, HRTEM, N2 physisorption, and thermal analysis. No SiW diffraction peaks are observed after loading 33-50 wt% of SiW on various mesoporous materials (pore size: -30 Å) except for siliceous MCM-48. In contrast, the SiW diffraction peaks appear at 14 wt% loading on zeolite EMT with micropore size of ca. 7.4 x 6.5 Å. Supported SiW retains the Keggin structure on mesopore surface. The cubic mesostructure of MCM-48 is stable while MCM-41 loses its regular hexagonal mesostructure upon loading SiW. Several factors account for different behaviours of various supports, including pore size, curvature of mesopore interface and interaction between SiW and aluminium sites in the framework. The resulting 33-50 wt% SiW/MCM-48 solid acid catalysts have large surface area (- 550 m2/g), regular pore arrangement with uniform pore size (- 25 Å), finely dispersed SiW and good thermal stability. They exhibit significantly improved activity in acid-catalyzed cracking of long-chain hydrocarbons in comparison with bulk SiW and SiW/MCM-41. PMID:25924405

  5. Ultrasonic cleaning of depleted uranium material as an alternative to nitric acid cleaning

    SciTech Connect

    Frye, L.E.; Senviel, C.B.

    1991-05-28

    Nitric acid is used to clean depleted uranium in the form of cast billets, and cast and wrought parts in the processing cycle and is the largest contributor of waste to the West End Treatment Facility (WETF). An estimated 27,000 gallons of liquid and 75 to 95% of all uranium received was sent to the WETF for processing from this facility in our baseline year. Because wrought parts account for the largest throughput at the nitric acid facility, an alternative cleaning method for these parts was examined first. Test results on the first part type from the wrought family showed ultrasonic cleaning to be an effective cleaning method. Since the geometry for this part presented the most difficulty in terms of ultrasonic cleaning, the entire wrought family is expected to be moved from the nitric acid facility to the ultrasonic cleaning facility. As a result, there will be an 83% reduction part throughput at the nitric acid facility which corresponds to a significant decrease in wastes sent to the WETF and a reduction in the generation and associated costs of waste overall. This change also eliminated two building moves involving two RAD areas resulting in a part movement reduction of approximately 25% which is a significant cost savings.

  6. Growth and characterization of a new NLO material: L-Glutamic acid hydro bromide [L-GluHBr

    SciTech Connect

    Sathyalakshmi, R.; Bhagavannarayana, G.; Ramasamy, P.

    2009-05-06

    L-(+)-Glutamic acid hydro bromide, an isomorphic salt of L-glutamic acid hydrochloride, was synthesized and the synthesis was confirmed using Fourier transform infrared analysis. Solubility of the material in water was determined. L-Glutamic acid hydro bromide crystals were grown by low temperature solution growth using the solvent evaporation technique. Single crystal X-ray diffraction studies were carried out and the cell parameters, atomic co-ordinates, bond lengths and bond angles were reported. High-resolution X-ray diffraction studies were carried out and good crystallinity for the grown crystal was observed from the diffraction curve. The grown crystals were subjected to dielectric studies. Ultraviolet-visible-near infrared spectral analysis shows good optical transmission in the visible and infrared region of the grown crystals. The second harmonic generation efficiency of L-glutamic acid hydro bromide crystal was determined using the Kurtz powder test and it was found that it had efficiency comparable with that of the potassium di-hydrogen phosphate crystal.

  7. A study of the metal binding capacity of saccharinic acids formed during the alkali catalysed decomposition of cellulosic materials: nickel complexation by glucoisosaccharinic acids and xyloisosaccharinic acids.

    PubMed

    Almond, Michael; Belton, Daniel; Humphreys, Paul N; Laws, Andrew P

    2016-06-01

    The stoichiometry of the metal complexes formed between nickel and the ligand β-glucoisosaccharinic acid (β-GISA) and a racemic mixture of enantiomers of xyloisosaccharinic acid (XISA) has been determined at both neutral and alkaline pHs. Bjerrum plots, Job's plots and conductance measurements indicated that for each of the systems one to one Ni(ligand) complexes were formed at near neutral pHs (<7.5). At intermediate alkaline pHs (7.5-13) there is evidence to support the formation and precipitation of Ni2(ligand)(OH)3 complexes, finally, at high pH (>13) sparingly soluble Ni2(ligand)(OH)4 complexes were formed. The stability constants for the Ni(β-GISA), Ni(α-GISA) and Ni(XISA) complexes formed at neutral pH were determined under identical conditions using polarographic studies. The measured stability constants for Ni(β-GISA) (log10 β = 1.94 ± 0.15) and for Ni(α-GISA)(log10 β = 2.07 ± 0.13) are very similar; the value measured for the Ni(XISA) complex (log10 β = 0.83) was an order of magnitude smaller. The stability constants for the Ni2(Ligand)(OH)4 complexes formed at highly alkaline pHs were determined using the Schubert method. The measured stability constant for Ni2(β-GISA)(OH)4 (log10 β = 30.6 ± 0.5) was an order of magnitude bigger than the value for Ni2(α-GISA)(OH)4 (log10 β = 29.0 ± 0.5) measured under identical conditions. Attempts to measure the stability constant for Ni2(XISA)(OH)4 were unsuccessful; Ni2(XISA)(OH)4 complexes were not present in significant amounts at high pH to allow the log10β value to be determined by the Schubert method. PMID:27107221

  8. Active-material additives for high-rate lead/acid batteries: have there been any positive advances?

    NASA Astrophysics Data System (ADS)

    McGregor, K.

    Low positive mass utilization poses a major problem for lead/acid batteries, particularly at high discharge rates, and is one of the major factors that limits the specific energy of the battery. The reasons for the incomplete discharge at high rates are generally ascribed to a combination of various polarization phenomena including: (i) poor acid transport from the bulk of the solution in the interior of the plate, and (ii) a continuous decrease in the conductivity of the plates due to formation of non-conductive PbSO 4. One approach to alleviating these problems is to improve the positive-plate porosity and/or conductivity by the incorporation of additives into the positive active-material. The purpose of this paper is to reew recent work with such additives, and to appraise their effectiveness towards raising battery performance.

  9. Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR

    PubMed Central

    Teramura, Hiroshi; Sasaki, Kengo; Oshima, Tomoko; Aikawa, Shimpei; Matsuda, Fumio; Okamoto, Mami; Shirai, Tomokazu; Kawaguchi, Hideo; Ogino, Chiaki; Yamasaki, Masanori; Kikuchi, Jun; Kondo, Akihiko

    2015-01-01

    A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D) 1H-13 C hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16) peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13) peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45–0.59 g/g-dry biomass). Starch-derived components showed positive correlations (r = 0.71 to 0.96) with glucose, 5-hydroxymethylfurfural (5-HMF), and formate concentrations in the liquid hydrolysates, and negative correlations (r = –0.95 to –0.97) with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate. PMID:26083431

  10. Method for the extraction of the volatile compound salicylic acid from tobacco leaf material.

    PubMed

    Verberne, Marianne C; Brouwer, Nynke; Delbianco, Federica; Linthorst, Huub J M; Bol, John F; Verpoorte, Robert

    2002-01-01

    Salicylic acid (SA) is a signalling compound in plants which is able to induce systemic acquired resistance. In the analysis of SA in plant tissues, the extraction recovery is often very low and variable. This is mainly caused by sublimation of SA, especially during evaporation of organic solvents. Techniques have been designed in order to overcome this problem. In the first part of the extraction procedure, sublimation of SA was prevented by addition of 0.2 M sodium hydroxide. At a later stage of the extraction procedure, sublimation of SA during solvent evaporation was controlled by the addition of a small amount of HPLC eluent. In this way, recoveries in the range of 71-91% for free SA and 65-79% for acid-hydrolysed SA were obtained. Recoveries could be further optimised by the use of an internal standard to correct for volume changes after the addition of the HPLC eluent. PMID:11899606

  11. Antibacterial and Biofilm-Disrupting Coatings from Resin Acid-Derived Materials.

    PubMed

    Ganewatta, Mitra S; Miller, Kristen P; Singleton, S Parker; Mehrpouya-Bahrami, Pegah; Chen, Yung P; Yan, Yi; Nagarkatti, Mitzi; Nagarkatti, Prakash; Decho, Alan W; Tang, Chuanbing

    2015-10-12

    We report antibacterial, antibiofilm, and biocompatible properties of surface-immobilized, quaternary ammonium-containing, resin acid-derived compounds and polycations that are known to be efficient antimicrobial agents with minimum toxicities to mammalian cells. Surface immobilization was carried out by the employment of two robust, efficient chemical methods: Copper-catalyzed azide-alkyne 1,3-dipolar cycloaddition click reaction, and surface-initiated atom transfer radical polymerization. Antibacterial and antibiofilm activities against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli were strong. Hemolysis assays and the growth of human dermal fibroblasts on the modified surfaces evidenced their biocompatibility. We demonstrate that the grafting of quaternary ammonium-decorated abietic acid compounds and polymers from surfaces enables the incorporation of renewable biomass in an effective manner to combat bacteria and biofilm formation in biomedical applications. PMID:26324023

  12. Methods and materials for the production of L-lactic acid in yeast

    SciTech Connect

    Hause, Ben; Rajgarhia, Vineet; Suominen, Pirkko

    2009-05-19

    Recombinant yeast are provided having, in one aspect, multiple exogenous LDH genes integrated into the genome, while leaving native PDC genes intact. In a second aspect, recombinant yeast are provided having an exogenous LDH gene integrated into its genome at the locus of a native PDC gene, with deletion of the native PDC gene. The recombinant yeast are useful in fermentation process for producing lactic acid.

  13. Strong Fluorescent Smart Organogel as a Dual Sensing Material for Volatile Acid and Organic Amine Vapors.

    PubMed

    Xue, Pengchong; Yao, Boqi; Wang, Panpan; Gong, Peng; Zhang, Zhenqi; Lu, Ran

    2015-11-23

    An L-phenylalanine derivative (C12PhBPCP) consisting of a strong emission fluorophore with benzoxazole and cyano groups is designed and synthesized to realize dual responses to volatile acid and organic amine vapors. The photophysical properties and self-assembly of the said derivative in the gel phase are also studied. C12PhBPCP can gelate organic solvents and self-assemble into 1 D nanofibers in the gels. UV/Vis absorption spectral results show H-aggregate formation during gelation, which indicates strong exciton coupling between fluorophores. Both wet gel and xerogel emit strong green fluorescence because the cyano group suppresses fluorescence quenching in the self-assemblies. Moreover, the xerogel film with strong green fluorescence can be used as a dual chemosensor for quantitative detection of volatile acid and organic amine vapors with fast response times and low detection limits owing to its large surface area and amplified fluorescence quenching. The detection limits are 796 ppt and 25 ppb for gaseous aniline and trifluoroacetic acid (TFA), respectively. PMID:26449736

  14. Studies on the oxidation of hexamethylbenzene 2: Preparation of dimethylpyromellitic acid

    NASA Technical Reports Server (NTRS)

    Chiba, K.; Tomura, S.

    1986-01-01

    Hexamethylbenzene (HMB) was difficult to be oxidized with an alkaline potassium permanganate solution, since HMB was insoluble in an aqueous alkaline solution. But, when HMB was warmed with 50% nitric acid for a short time, and then treated with aqueous potassium permanganate, the reaction occurred readily and dimethylpyromellitic acid was obtained. When HMB was warmed with 50% nitric acid for 1 to 2 minutes, a yellow material was produced, which was soluble in hot aqueous potassium hydroxide, though free from carboxylic acids. It contained a little amount of bis-(nitromethyl)prehnitene and several unknown compounds. Further, the heat stability of polyimide prepared by the reaction of tetramethyldimethylpyromellitate with 4,4 prime-diaminodiphenylmethane turned out to be nearly equal to that of polyimide prepared from tetramethylpyromellitate.

  15. Development of a research method to measure insoluble and soluble starch in sugarcane factory and refinery products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rapid, quantitative research method using microwave-assisted probe ultrasonication was developed to facilitate the determination of total insoluble, and soluble starch in various sugar factory and refinery products. Several variables that affect starch solubilization were evaluated: 1) conductiv...

  16. Using a Simulated Industrial Setting for the Development of an Improved Solvent System for the Recrystallization of Benzoic Acid: A Student-Centered Project

    ERIC Educational Resources Information Center

    Hightower, Timothy R.; Heeren, Jay D.

    2006-01-01

    Recrystallization of benzoic acid is an excellent way to remove insoluble impurities. In a traditional organic laboratory experiment, insoluble impurities are removed through the recrystallization of benzoic acid utilizing water as the recrystallization solvent. It was our goal to develop a peer-led, problem-solving organic laboratory exercise…

  17. A Combined Study Investigating the Insoluble and Soluble Organic Compounds in Category 3 Carbonaceous Itokawa Particles Recovered by the Hayabusa Mission

    NASA Technical Reports Server (NTRS)

    Chan, Q. H. S.; Zolensky, M.; Burton, A.; Clemett, S.; Fries, M.; Kebukawa, Y.

    2015-01-01

    At the 3rd International Announcement of Opportunity (AO), we have been approved for five Category 3 carbonaceous Itokawa particles (RA-QD02-0012, RA-QD02-0078, RB-CV-0029, RB-CV-0080 and RB-QD04-0052) recovered by the first Hayabusa mission of JAXA. In this investigation, we aim to provide a comprehensive study to characterize and account for the presence of carbon-bearing phases as suggested by the initial Scanning Electron Microscopy (SEM) analysis carried out by JAXA at the curation facility, and to describe the mineralogical components of the particles. The insoluble organic content of Itokawa particle has been investigated with the use of micro-Raman spectroscopy by Kitajima and co-workers [1]. The Raman spectra of Itokawa particles show broad G- and D-bands typical of low temperature material which offers an interesting contrast to the high metamorphic grade (LL4-6) of the Itokawa parent body. Amino acid analysis has been conducted by Naraoka et al. [2] to study the soluble organic component of Itokawa particles, but since it was a preliminary study and thus did not have the opportunity to target on Category 3 carbonaceous particles, only terrestrial contaminants were identified. The investigation will be carried out in the following order prioritized according to the progressive damage the analytical techniques can induce: (1) micro-Raman spectrometry, (2) two-step laser mass spectrometry (micro-L2MS), (3) ultra-high performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry (LC-FD/ToF-MS), and optimally if we can recover the particles after wet chemistry analysis, we will mount the samples and perform (4) electron beam microscopy (SEM, electron back-scattered diffraction [EBSD]) and (5) carbon X-ray absorption near edge structure spectroscopy (C-XANES). We will begin the analytical procedures upon receiving the samples in September/October. This work will provide us with an understanding of the variety and origins of

  18. Determination of bile acids in human serum by on-line restricted access material-ultra high-performance liquid chromatography-mass spectrometry.

    PubMed

    Bentayeb, K; Batlle, R; Sánchez, C; Nerín, C; Domeño, C

    2008-06-15

    This paper describes a new, fully automated on-line method combining restricted access material (RAM) extraction and ultra high-performance liquid chromatography (UHPLC) with mass spectrometric (MS) detection for determining congeners of bile acids (BAs) in human serum. In this method, low-pressure RAM and high-pressure UHPLC-MS are hyphenated by using a 2.5-mL loop-type interface. The compatibility problem between the large volume (1.2mL) of strong solvent (methanol) used for RAM elution and the need for a weak solvent in UHPLC injection has been addressed by using an auxiliary pre-column cross-flow of 0.1% aqueous formic acid. In this way, the complete 2.5mL loop volume can be injected into the UHPLC system, thereby maximizing sensitivity while maintaining good chromatographic performance. The optimised method allows the simultaneous analysis of 13 bile acids in a single run, including glycine- and taurine-conjugated bile acids, cholic acid (CA), deoxycholic acid (DCA), chenodeoxycholic acid (CDCA), ursodeoxycholic acid (UDCA), and litocholic acid. The complete analysis of a 100-microL single serum sample is performed in 30 min, providing detection limits in the pg range (corresponding with clinically relevant concentration levels) for all of the analytes except lithocholic acid, intra-day precision values (%R.S.D.) below 4% (except ursodeoxycholic acid) and inter-day precision lower than 15% (except ursodeoxycholic, glycoursodeoxycholic acid (GUDCA) and lithocholic acid). PMID:18514045

  19. Development of Lentivirus-Based Reference Materials for Ebola Virus Nucleic Acid Amplification Technology-Based Assays

    PubMed Central

    Mattiuzzo, Giada; Ashall, James; Doris, Kathryn S.; MacLellan-Gibson, Kirsty; Nicolson, Carolyn; Wilkinson, Dianna E.; Harvey, Ruth; Almond, Neil; Anderson, Robert; Efstathiou, Stacey; Minor, Philip D.; Page, Mark

    2015-01-01

    The 2013-present Ebola virus outbreak in Western Africa has prompted the production of many diagnostic assays, mostly based on nucleic acid amplification technologies (NAT). The calibration and performance assessment of established assays and those under evaluation requires reference materials that can be used in parallel with the clinical sample to standardise or control for every step of the procedure, from extraction to the final qualitative/quantitative result. We have developed safe and stable Ebola virus RNA reference materials by encapsidating anti sense viral RNA into HIV-1-like particles. The lentiviral particles are replication-deficient and non-infectious due to the lack of HIV-1 genes and Envelope protein. Ebola virus genes were subcloned for encapsidation into two lentiviral preparations, one containing NP-VP35-GP and the other VP40 and L RNA. Each reference material was formulated as a high-titre standard for use as a calibrator for secondary or internal standards, and a 10,000-fold lower titre preparation to serve as an in-run control. The preparations have been freeze-dried to maximise stability. These HIV-Ebola virus RNA reference materials were suitable for use with in-house and commercial quantitative RT-PCR assays and with digital RT-PCR. The HIV-Ebola virus RNA reference materials are stable at up to 37°C for two weeks, allowing the shipment of the material worldwide at ambient temperature. These results support further evaluation of the HIV-Ebola virus RNA reference materials as part of an International collaborative study for the establishment of the 1st International Standard for Ebola virus RNA. PMID:26562415

  20. FIELD EXPOSURE STUDY FOR DETERMINING THE EFFECTS OF ACID DEPOSITION ON THE CORROSION AND DETERIORATION OF MATERIALS: DESCRIPTION OF PROGRAM AND PRELIMINARY RESULTS

    EPA Science Inventory

    Materials exposure sites, fully instrumented to characterize environmental parameters related to air quality, meteorology, and rain chemistry, have been established at four locations in the eastern and northeastern United States to study the effects of acid precipitation on atmos...

  1. 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. PMID:27287146

  2. Acid rain and weathering damage to carbonate building stone: Results of material loss measurements

    SciTech Connect

    Reddy, M.; Youngdahl, C.A.

    1987-01-01

    Marble and limestone specimens were exposed to atmospheric conditions at four eastern U.S. sites. A number of methods were employed for damage assessment; this paper describes the results of chemical and physical measurements of material loss. Good agreement was observed among results obtained with different methods. A rate of surface recession near 15 ..mu..m/y was observed for skyward surfaces of marble tested in North Carolina, and comparable results were obtained at the other test sites. Response of the porous limestone was assessed with greater difficulty; a rate of loss similar to that of marble was inferred. Initial correlations of material loss with environmental factors are briefly discussed.

  3. Acid rain and weathering damage to carbonate building stone: Results of material loss measurements

    SciTech Connect

    Reddy, M.M.; Youngdahl, C.A.

    1986-11-01

    Marble and limestone specimens were exposed to atmospheric conditions at four eastern US sites. A number of methods were employed for damage assessment; this paper describes the results of chemical and physical measurements of material loss. Good agreement was observed among results obtained with different methods. A rate of surface recession near 15 ..mu..m/y was observed for skyward surfaces of marble tested in North Carolina, and comparable results were obtained at the other test sites. Response of the porous limestone was assessed with greater difficulty; a rate of loss similar to that of marble was inferred. Initial correlations of material loss with environmental factors are briefly discussed.

  4. Morphological study of Insoluble Organic Matter from carbonaceous chondrites: Correlation with petrologic grade

    NASA Astrophysics Data System (ADS)

    Changela, Hitesh G.

    2015-06-01

    The major form of organic material delivered to Earth from an extraterrestrial origin is Insoluble Organic Matter (IOM). A morphological study of IOM in the CR (Renazzo-type) and CM (Mighei-type) carbonaceous chondrites was performed in order to constrain its origins and processing history. IOM residues from the following CR chondrites: GRO 95577 (CR1), Al Rais (CR1/2), EET 92042 (CR2), QUE 99177 (CR3) and the CM chondrites: MET 01070 (CM2.2), Cold Bokkeveld (CM2.3), Murchison (CM2.4) and QUE 97990 (CM2.5) were studied using Annular Dark Field STEM imaging. Characteristic features of the IOM, organic nanoglobules, were manually identified and measured for their abundances and size distributions. The IOM residues were also compared holistically for their degree of average 'roughness' or 'coarsening' using fractal image analysis. Manually identified nanoglobules have abundances making up less than 10% of the total IOM, which is consistent with previous studies. Their measured abundances do not correlate with petrologic grade. Thus parent body processing did not systematically deplete their abundances. The IOM is however on average 'smoother' or 'coarser' in the more altered chondrites, demonstrated by a lower fractal dimension using fractal box counting (DB). The DB values for the IOM in the CR chondrites are distinctive: QUE 99177 has the largest DB value (average = 1.54 ± 0.004) and GRO 99577 has the lowest (average = 1.45 ± 0.011). Al Rais and EET 92042 have IOM with average DB values within this range (average, 1.46 ± 0.009 and 1.50 ± 0.006). The CMs record a similar but less distinctive trend in DB, with QUE 97990 having the largest value (1.52 ± 0.004), MET 01070 the lowest (1.45 ± 0.019), and Cold Bokkeveld (1.50 ± 0.011) and Murchison (1.49 ± 0.017) equivalent to one another within error. The identified nanoglobules in the IOM of the CM chondrites are on average larger than those in the CR chondrites. The 'coarsening' or 'smoother' texture of the IOM

  5. The Interaction Between an Insoluble Particle and an Advancing Solid/Liquid Interface: Micro-Gravity Experiments and Theoretical Developments

    NASA Technical Reports Server (NTRS)

    Catalina, Adrian V.; Ssen, Subhayu; Stefanescu, Doru M.

    2003-01-01

    The interaction of an insoluble particle with an advancing solid/liquid interface (SLI) has been a subject of investigation for the past four decades. While the original interest stemmed from geology applications (e.g., frost heaving in soil), researchers soon realized that the complex science associated with such an interaction is relevant to many other scientific fields encompassing metal matrix composites (MMCs), high temperature superconductors, inclusion management in steel, growth of monotectics, and preservation of biological cells. During solidification of a liquid containing an insoluble particle, three distinct interaction phenomena have been experimentally observed: instantaneous engulfment of the particle, continuous pushing, and particle pushing followed by engulfment. It was also observed that for given experimental conditions and particle size there is a critical solidification velocity, V(sub cr), above which a particle is engulfed. During solidification of MMCs pushing leads to particle agglomeration at the grain boundaries and this has detrimental effects on mechanical properties of the casting. Consequently, the process must be designed for instantaneous engulfment to occur. This implies the development of accurate theoretical models to predict V(sub cr), and perform benchmark experiments to test the validity of such models. Although considerable progress has been made in understanding the pushing/engulfment phenomenon (PEP), its quantification in terms of the material and processing parameters remains a focus of research. Since natural convection currents occurring during terrestrial solidification experiments complicate the study of PEP, execution of experiments on the International Space Station (ISS) has been approved and funded by NASA. Extensive terrestrial (1g) experiments and preliminary micro-gravity (mu g) experiments on two space shuttle missions have been conducted in preparation for future experiments on the ISS. The investigated

  6. Ligand-induced association of surface immunoglobulin with the detergent insoluble cytoskeleton may involve an 89K protein

    SciTech Connect

    Gupta, S.K.; Woda, B.

    1986-03-01

    Membrane immunoglobulin of B-lymphocytes is thought to play an important role in antigen recognition and cellular activation. Binding of cross-linking ligands to surface immunoglobulin (SIg) on intact cells converts it to a detergent insoluble state, and this conversion is associated with the transmission of a mitogenic signal. Insolubilized membrane proteins may be solubilized by incubating the detergent insoluble cytoskeletons in buffers which convert F-actin to G-actin ((Buffer 1), 0.34M sucrose, 0.5mM ATP, 0.5mM Dithiothrietol and lmM EDTA). Immunoprecipitation of SIg from the detergent soluble fraction of /sup 35/S-methionine labeled non ligand treated rat B-cells results in the co-isolation of an 89K protein and a 44K protein, presumably actin. The 89K protein is not associated with the fraction of endogenous detergent insoluble SIg. On treatment of rat B cells with cross-linking ligand (anti-Ig) the 89K protein becomes detergent insoluble along with most of the SIg and co-isolates with SIg on immunoprecipitation of the detergent insoluble, buffer l solubilized fraction. The migration of the SIg-associated 89K protein from the detergent soluble fraction to the detergent insoluble fraction after ligand treatment, suggests that this protein might be involved in linking SIg to the underlying cytoskeleton and could be involved in the transmission of a mitogenic signal.

  7. SORPTION BEHAVIOR OF MONOSODIUM TITANATE AND AMORPHOUS PEROXOTITANATE MATERIALS UNDER WEAKLY ACIDIC CONDITIONS

    SciTech Connect

    Hobbs, D.; Elvington, M.; Click, D.

    2009-11-11

    Inorganic, titanate-based sorbents are tested with respect to adsorption of a variety of sorbates under weakly acidic conditions (pH 3). Specifically, monosodium titanate (MST) and amorphous peroxotitanate (APT) sorption characteristics are initially probed through a screening process consisting of a pair of mixed metal solutions containing a total of 29 sorbates including alkali metals, alkaline earth metals, transition metals, metalloids and nonmetals. MST and APT sorption characteristics are further analyzed individually with chromium(III) and cadmium(II) using a batch method at ambient laboratory temperature, varying concentrations of the sorbents and sorbates and contact times. Maximum sorbate loadings are obtained from the respective adsorption isotherms.

  8. Environmental monitoring study of linear alkylbenzene sulfonates and insoluble soap in Spanish sewage sludge samples.

    PubMed

    Cantarero, Samuel; Zafra-Gómez, Alberto; Ballesteros, Oscar; Navalón, Alberto; Reis, Marco S; Saraiva, Pedro M; Vílchez, José L

    2011-01-01

    In this work we present a monitoring study of linear alkylbenzene sulfonates (LAS) and insoluble soap performed on Spanish sewage sludge samples. This work focuses on finding statistical relations between LAS concentrations and insoluble soap in sewage sludge samples and variables related to wastewater treatment plants such as water hardness, population and treatment type. It is worth to mention that 38 samples, collected from different Spanish regions, were studied. The statistical tool we used was Principal Component Analysis (PC), in order to reduce the number of response variables. The analysis of variance (ANOVA) test and a non-parametric test such as the Kruskal-Wallis test were also studied through the estimation of the p-value (probability of obtaining a test statistic at least as extreme as the one that was actually observed, assuming that the null hypothesis is true) in order to study possible relations between the concentration of both analytes and the rest of variables. We also compared LAS and insoluble soap behaviors. In addition, the results obtained for LAS (mean value) were compared with the limit value proposed by the future Directive entitled "Working Document on Sludge". According to the results, the mean obtained for soap and LAS was 26.49 g kg(-1) and 6.15 g kg(-1) respectively. It is worth noting that LAS mean was significantly higher than the limit value (2.6 g kg(-1)). In addition, LAS and soap concentrations depend largely on water hardness. However, only LAS concentration depends on treatment type. PMID:21526451

  9. Dietary total and insoluble fiber intakes are inversely associated with prostate cancer risk.

    PubMed

    Deschasaux, Mélanie; Pouchieu, Camille; His, Mathilde; Hercberg, Serge; Latino-Martel, Paule; Touvier, Mathilde

    2014-04-01

    Although experimental data suggest a potentially protective involvement of dietary fiber in prostate carcinogenesis, very few prospective studies have investigated the relation between dietary fiber intake and prostate cancer risk, and those have had inconsistent results. Our objective was to study the association between dietary fiber intake (overall, insoluble, soluble, and from different sources, such as cereals, vegetables, fruits, and legumes) and prostate cancer risk. Stratifications by excess weight status, insulin-like growth factors, and amount of alcohol intake were also considered. This prospective analysis included 3313 men from the Supplémentation en Vitamines et Minéraux Antioxydants (SU.VI.MAX) cohort who completed at least 3 24-h dietary records. One hundred thirty-nine incident prostate cancers were diagnosed between 1994 and 2007 (median follow-up of 12.6 y). Associations between quartiles of energy-adjusted dietary fiber intake and prostate cancer risk were characterized by multivariate Cox proportional hazards models. Prostate cancer risk was inversely associated with total dietary fiber intake (HR of quartile 4 vs. quartile 1 = 0.47; 95% CI: 0.27, 0.81; P = 0.001), insoluble (HR = 0.46; 95% CI: 0.27, 0.78; P = 0.001), and legume (HR = 0.55; 95% CI: 0.32, 0.95; P = 0.04) fiber intakes. In contrast, we found no association between prostate cancer risk and soluble (P = 0.1), cereal (P = 0.7), vegetable (P = 0.9), and fruit (P = 0.4) fiber intakes. In conclusion, dietary fiber intake (total, insoluble, and from legumes but not soluble or from cereals, vegetables, and fruits) was inversely associated with prostate cancer risk, consistent with mechanistic data. PMID:24553693

  10. Hollow mesoporous silica as a high drug loading carrier for regulation insoluble drug release.

    PubMed

    Geng, Hongjian; Zhao, Yating; Liu, Jia; Cui, Yu; Wang, Ying; Zhao, Qinfu; Wang, Siling

    2016-08-20

    The purpose of this study was to develop a high drug loading hollow mesoporous silica nanoparticles (HMS) and apply for regulation insoluble drug release. HMS was synthesized using hard template phenolic resin nanoparticles with the aid of cetyltrimethyl ammonium bromide (CTAB), which was simple and inexpensive. To compare the difference between normal mesoporous silica (NMS) and hollow mesoporous silica in drug loading efficiency, drug release behavior and solid state, NMS was also prepared by soft template method. Transmission electron microscopy (TEM), specific surface area analysis, FT-IR and zeta potential were employed to characterize the morphology structure and physicochemical property of these carriers. The insoluble drugs, carvedilol and fenofibrate(Car and Fen), were chosen as the model drug to be loaded into HMS and NMS. We also chose methylene blue (MB) as a basic dye to estimate the adsorption ability of these carriers from macroscopic and microscopic view, and the drug-loaded carriers were systematically studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and UV-vis spectrophotometry. What' more, the in vivo process of HMS was also study by confocal microscopy and in vivo fluorescence imaging. In order to confirm the gastrointestinal safety of HMS, the pathological examination of stomach and intestine also be evaluated. HMS allowed a higher drug loading than NMS and exhibited a relative sustained release curve, while NMS was immediate-release. And the effect of preventing drugs crystallization was weaker than NMS. As for in vivo process, HMS was cleared relatively rapidly from the mouse gastrointestinal and barely uptake by intestinal epithelial cell in this study due to its large particle size. And the damage of HMS to gastrointestinal could be ignored. This study provided a simple method to obtain high drug loading and regulation insoluble drug release, expanded the application of inorganic carriers in drug delivery system

  11. Porous carbon material containing CaO for acidic gas capture: preparation and properties.

    PubMed

    Przepiórski, Jacek; Czyżewski, Adam; Pietrzak, Robert; Toyoda, Masahiro; Morawski, Antoni W

    2013-12-15

    A one-step process for the preparation of CaO-containing porous carbons is described. Mixtures of poly(ethylene terephthalate) with natural limestone were pyrolyzed and thus hybrid sorbents could be easily obtained. The polymeric material and the mineral served as a carbon precursor and CaO delivering agent, respectively. We discuss effects of the preparation conditions and the relative amounts of the raw materials used for the preparations on the porosity of the hybrid products. The micropore areas and volumes of the obtained products tended to decrease with increasing CaO contents. Increase in the preparation temperature entailed a decrease in the micropore volume, whereas the mesopore volume increased. The pore creation mechanism is proposed on the basis of thermogravimetric and temperature-programmed desorption measurements. The prepared CaO-containing porous carbons efficiently captured SO2 and CO2 from air. Washing out of CaO from the hybrid materials was confirmed as a suitable method to obtain highly porous carbon materials. PMID:23743266

  12. Active packaging materials from Poly(Lactic Acid)and Pectin composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Active packaging of foods is receiving considerable attention from the food industry and food researchers. The ability to wrap foods in packaging materials that can provide additional functions, such as retaining freshness or preventing spoilage and pathogen growth, would be very important for the f...

  13. Materialism.

    PubMed

    Melnyk, Andrew

    2012-05-01

    Materialism is nearly universally assumed by cognitive scientists. Intuitively, materialism says that a person's mental states are nothing over and above his or her material states, while dualism denies this. Philosophers have introduced concepts (e.g., realization and supervenience) to assist in formulating the theses of materialism and dualism with more precision, and distinguished among importantly different versions of each view (e.g., eliminative materialism, substance dualism, and emergentism). They have also clarified the logic of arguments that use empirical findings to support materialism. Finally, they have devised various objections to materialism, objections that therefore serve also as arguments for dualism. These objections typically center around two features of mental states that materialism has had trouble in accommodating. The first feature is intentionality, the property of representing, or being about, objects, properties, and states of affairs external to the mental states. The second feature is phenomenal consciousness, the property possessed by many mental states of there being something it is like for the subject of the mental state to be in that mental state. WIREs Cogn Sci 2012, 3:281-292. doi: 10.1002/wcs.1174 For further resources related to this article, please visit the WIREs website. PMID:26301463

  14. Characterization and acidic properties of Al-SBA-15 materials prepared by post-synthesis alumination of a low-cost ordered mesoporous silica

    SciTech Connect

    Gomez-Cazalilla, M.; Merida-Robles, J.M.; Gurbani, A.; Rodriguez-Castellon, E.; Jimenez-Lopez, A.

    2007-03-15

    A series of Al-containing SBA-15 type materials with different Si/Al ratio, were prepared by post-synthesis modification of a pure highly ordered mesoporous silica SBA-15 obtained by using sodium silicate as silica source, and amphiphilic block copolymer as structure-directing agent. A high level of aluminum incorporation was achieved, reaching an Si/Al ratio of up to 5.5, without any significant loss in the textural properties of SBA-15. These materials were fully characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), {sup 27}Al NMR spectroscopy, and N{sub 2} adsorption at 77 K. The acid properties of these materials have been evaluated by NH{sub 3}-TPD, adsorption of pyridine and deuterated acetonitrile coupled to FTIR spectroscopy. The effective acidity of these materials was evaluated using two catalytic reactions: 2-propanol dehydrogenation and 1-butene isomerization. The adsorption of basic probe molecules and the catalytic behavior revealed an evolution of the acid properties with the Al content. These studies have shown that the Al-SBA-15 materials contain Bronsted and Lewis acid sites with medium acidity which makes them appropriate to be used as acid catalysts in heterogeneous catalysis, catalytic supports, and adsorbents. - Graphical abstract: Al KLL spectra of Al-SBA-15 materials with different Si/Al ratios.

  15. Two new insoluble polymer composites for the treatment of LLW: 1. polypyrrole doped by UO22+ complexing polyanions 2. UO22+ complexing sol-gel based composites. Stability constants. Leaching tests, alpha and gamma irradiation

    NASA Astrophysics Data System (ADS)

    Leroy, D.; Martinot, L.; Mignonsin, P.; Caprasse, F.; Jérôme, C.; Jérôme, R.

    2000-07-01

    In a previous work, we have demonstrated that polyanions like polyacrylamidoglycolic acid (PAAG) and polyacrylamidomethylpropanesulfonic acid (PAMPS) are capable to complex UO22+ ions. Unless they are crosslinked, these polyanions/UO22+ complexes are soluble when submitted to dynamic leaching tests in a Soxhlet extractor. Considering the feasibility of a new process for the storage or for the concentration of low level activity liquid wastes (LLW), we had to strongly enhance the insolubility of these complexes. We have developed two original insolubilization ways, as compared to the crosslinking of the polymer.

  16. Time Dependence of Material Properties of Polyethylene Glycol Hydrogels Chain Extended with Short Hydroxy Acid Segments

    PubMed Central

    Barati, Danial; Moeinzadeh, Seyedsina; Karaman, Ozan; Jabbari, Esmaiel

    2014-01-01

    The objective of this work was to investigate the effect of chemical composition and segment number (n) on gelation, stiffness, and degradation of hydroxy acid-chain-extended star polyethylene glycol acrylate (SPEXA) gels. The hydroxy acids included glycolide (G,), L-lactide (L), p-dioxanone (D) and -caprolactone (C). Chain-extension generated water soluble macromers with faster gelation rates, lower sol fractions, higher compressive moduli, and a wide-ranging degradation times when crosslinked into a hydrogel. SPEGA gels with the highest fraction of inter-molecular crosslinks had the most increase in compressive modulus with n whereas SPELA and SPECA had the lowest increase in modulus. SPEXA gels exhibited a wide range of degradation times from a few days for SPEGA to a few weeks for SPELA, a few months for SPEDA, and many months for SPECA. Marrow stromal cells and endothelial progenitor cells had the highest expression of vasculogenic markers when co-encapsulated in the faster degrading SPELA gel. PMID:25267858

  17. Multifunctional materials such as MCM-41÷Fe3O4÷folic acid as drug delivery system.

    PubMed

    Popescu, Simona; Ardelean, Ioana Lavinia; Gudovan, Dragoş; Rădulescu, Marius; Ficai, Denisa; Ficai, Anton; Vasile, Bogdan Ştefan; Andronescu, Ecaterina

    2016-01-01

    In this study, MCM-41 mesoporous silica nanoparticles (NPs) and MCM-41÷Fe3O4 mesoporous silica NPs were prepared by sol-gel method using CTAB (cetyltrimethylammonium bromide) as template and TEOS (tetraethyl orthosilicate) as silica precursor in order to use these materials as drug delivery system (DDS) for different biologically active agents. The MCM-41 and MCM-41÷Fe3O4 mesoporous silica NPs were characterized using specific physico-chemical methods [transmission electron microscopy (TEM), scanning electron microscopy (SEM), nitrogen adsorption and desorption studies - BET (Brunauer-Emmett-Teller) method, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy], while the release studies were done by a high-performance liquid chromatography (HPLC)-modified method. The pH dependence of the delivery of folic acid from the mesoporous structures was analyzed and found that the release is pH sensitive. The lower delivery at strongly acid pH comparing with neutral/slightly alkaline pH could be beneficial because in stomach the folic acid can be destroyed. PMID:27516022

  18. A comparison of water solubility enhancements of organic solutes by aquatic humic materials and commercial humic acids

    USGS Publications Warehouse

    Chlou, C.T.; Kile, D.E.; Brinton, T.I.; Malcolm, R.L.; Leenheer, J.A.; MacCarthy, P.

    1987-01-01

    Water solubility enhancements of 1,1-bis(p-chloro-phenyl)-2,2,2-trichloroethane (p,p???-DDT), 2,4,5,2???,5???-pentachlorobiphenyl (2,4,5,2???,5???-PCB), and 2,4,4???-tri-chlorobiphenyl (2,4,4???-PCB) by dissolved organic matter have been studied with the following samples: (1) acidic water samples from the Suwannee River, Georgia, and the Sopchoppy River, Florida; (2) a humic extract of a nearly neutral pH water from the Calcasieu River, Louisiana; (3) commercial humic acids from the Aldrich Chemical Co. and Fluka-Tridom Chemical Corp. The calculated partition coefficients on a dissolved organic carbon basis (Kdoc) for organic solutes with water samples and aquatic humic extracts from this and earlier studies indicate that the enhancement effect varies with the molecular composition of the aquatic humic materials. The Kdoc values with water and aquatic humic samples are, however, far less than the observed Kdoc values obtained with the two commercial samples, by factors of about 4-20. In view of this finding, one should be cautious in interpreting the effects of the dissolved organic matter on solubility enhancement of organic solutes on the basis of the use of commercial humic acids.

  19. 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. PMID:26836709

  20. Contact of clay-liner materials with acidic tailings. II. Chemical modeling

    SciTech Connect

    Peterson, S.R.; Krupka, K.M.

    1981-09-01

    The ion speciation-solubility model WATEQ3 was used to model original aqueous solutions and solutions resulting from liner materials contacted with uranium mill tailings, synthetic mill tailings or H/sub 2/SO/sub 4/. The modeling results indicate solution species which are in apparent equilibrium with respect to particular solids. These solids provide potential solubility controls for their corresponding dissolved constituents. The disequilibrium indices computed by WATEQ3 indicate amorphic Fe(OH)/sub 3/(A), Al0HO/sub 4/, alunite (KA1/sub 3/(SO/sub 4/)/sub 2/(OH)/sub 6/), gypsum (CaSO/sub 4/ . 2H/sub 2/O), celestite (SrSO/sub 4/), anglesite (PbSO/sub 4/) and MnHPO/sub 4/ may have precipitated in the contacted liner materials and may also provide solubility controls for their dissolved constituents. The disequilibrium indices also show that the solutions resulting from the interaction of Highland Mill tailings are oversaturated with K-, H-, and Na-jarosites ((K,H,Na)Fe/sub 3/(SO/sub 4/)/sub 2/(OH)/sub 6/). Because jarosite has been identified by x-ray diffraction as a precipitate in these reacted liner materials, it would appear that there is a kinetic barrier which prohibits jarosite from being an effective solubility control. Results of this study also show that the solubilities of many solid phases were pH dependent. This exploratory use of geochemical modeling has demonstrated its capability to test solubility hypotheses for clay liners reacted with tailings solutions and to guide the analyses of important constituents and parameters for these solutions. Geochemical modeling can be used, in parallel with characterization techniques for the solid phases, to support the presence of the solid phase and to guide the search for further solid phases. Geochemical modeling is also an effective tool in delineating the chemical causes for changes in permeability of liner materials.

  1. Self-assembly of nucleic acids, silk and hybrid materials thereof

    NASA Astrophysics Data System (ADS)

    Humenik, Martin; Scheibel, Thomas

    2014-12-01

    Top-down approaches based on etching techniques have almost reached their limits in terms of dimension. Therefore, novel assembly strategies and types of nanomaterials are required to allow technological advances. Self-assembly processes independent of external energy sources and unlimited in dimensional scaling have become a very promising approach. Here, we highlight recent developments in self-assembled DNA-polymer, silk-polymer and silk-DNA hybrids as promising materials with biotic and abiotic moieties for constructing complex hierarchical materials in ‘bottom-up’ approaches. DNA block copolymers assemble into nanostructures typically exposing a DNA corona which allows functionalization, labeling and higher levels of organization due to its specific addressable recognition properties. In contrast, self-assembly of natural silk proteins as well as their recombinant variants yields mechanically stable β-sheet rich nanostructures. The combination of silk with abiotic polymers gains hybrid materials with new functionalities. Together, the precision of DNA hybridization and robustness of silk fibrillar structures combine in novel conjugates enable processing of higher-order structures with nanoscale architecture and programmable functions.

  2. Synthesis, crystal growth and characterization of an organic material: 2-Aminopyridinium succinate succinic acid single crystal.

    PubMed

    Magesh, M; Bhagavannarayana, G; Ramasamy, P

    2015-11-01

    The 2-aminopyridinium succinate succinic acid (2APS) single crystal was synthesized and grown by slow evaporation method. The crystal structure has been confirmed by powder X-ray diffraction as well as single crystal X-ray diffraction analysis. The crystal perfection has been evaluated by high resolution X-ray diffraction (HRXRD). The grown crystal is transparent in the visible and near infrared region. The optical absorption edge was found to be 348 nm. The fluorescence study was carried out by spectrofluorophotometer. The thermal stability of grown crystal was analyzed by thermal gravimetric and differential thermal gravimetric (TG-DTA) analysis. Vicker's hardness study carried out at room temperature shows increased hardness while increasing the load. Laser damage threshold value was determined by Nd:YAG laser operating at 1064 nm. The grown 2APS crystal was characterized by etching studies using water as etchant. PMID:26099828

  3. Hyaluronic acid biodegradable material for reconstruction of vascular wall: a preliminary study in rats.

    PubMed

    Pandis, Laura; Zavan, Barbara; Bassetto, Franco; Ferroni, Letizia; Iacobellis, Laura; Abatangelo, Giovanni; Lepidi, Sandro; Cortivo, Roberta; Vindigni, Vincenzo

    2011-02-01

    The objective of this preliminary study was to develop a reabsorbable vascular patch that did not require in vitro cell or biochemical preconditioning for vascular wall repair. Patches were composed only of hyaluronic acid (HA). Twenty male Wistar rats weighing 250-350 g were used. The abdominal aorta was exposed and isolated. A rectangular breach (1 mm × 5 mm) was made on vessel wall and arterial defect was repaired with HA made patch. Performance was assessed at 1, 2, 4, 8, and 16 weeks after surgery by histology and immunohistochemistry. Extracellular matrix components were evaluated by molecular biological methods. After 16 weeks, the biomaterial was almost completely degraded and replaced by a neoartery wall composed of endothelial cells, smooth muscle cells, collagen, and elastin fibers organized in layers. In conclusion, HA patches provide a provisional three-dimensional support to interact with cells for the control of their function, guiding the spatially and temporally multicellular processes of artery regeneration. PMID:21268111

  4. Corrosion-resistant iridium-platinum anode material for high polarization application in corrosive acids

    SciTech Connect

    Farmer, J.; Summers, L.; Lewis, P.

    1993-09-08

    The present invention relates to highly corrosion resistant components for use in an electrochemical cell. Specifically, these components are resistant to corrosion under very extreme conditions such as exposure to aqua regia in the presence of a constant current density of 100mA/m{sup 2}. The components are comprised of an iridium-platinum alloy that comprises less than 30% iridium. In a preferred embodiment of the present invention, the iridium-platinum alloy comprises 15-20% iridium. In another preferred embodiment of the present invention, the iridium-platinum alloy is deposited on the surface of an electrochemical cell component by magnetron sputtering. The present invention also relates to a method for conducting an electrochemical reaction in the presence of highly corrosive acids under a high degree of polarization wherein the electrochemical cell comprises a component, preferably the anode, containing an iridium-platinum alloy that comprises less than 30% iridium.

  5. A review of poly(lactic acid)-based materials for antimicrobial packaging.

    PubMed

    Tawakkal, Intan S M A; Cran, Marlene J; Miltz, Joseph; Bigger, Stephen W

    2014-08-01

    Poly(lactic acid) (PLA) can be synthesized from renewable bio-derived monomers and, as such, it is an alternative to conventional petroleum-based polymers. Since PLA is a relatively new polymer, much effort has been directed toward its development in order to make it an acceptable and effective option to the more traditional petroleum-based polymers. Commercially, PLA has received considerable attention in food packaging applications with a focus on films and coatings that are suitable for short shelf life and ready-to-eat food products. The potential for PLA to be used in active packaging has also been recognized by a number of researchers. This review focuses on the use of PLA in antimicrobial systems for food packaging applications and explores the engineering characteristics and antimicrobial activity of PLA films incorporated and/or coated with antimicrobial agents. PMID:25039867

  6. Active, soluble recombinant melittin purified by extracting insoluble lysate of Escherichia coli without denaturation

    PubMed Central

    Buhrman, Jason S.; Cook, Laura C.; Rayahin, Jamie E.; Federle, Michael J.; Gemeinhart, Richard A.

    2013-01-01

    Cell lytic peptides are a class of drugs that can be used to selectively kill invading organisms or diseased cells. Several of these peptides have been identified as potential therapeutics. Herein, we report a novel process for purifying recombinant melittin, a cell lytic peptide that inserts into the membranes of cells causing cell lysis, from Escherichia coli. The process involves surfactant and low pH to solubilize melittin fusion proteins from the insoluble fraction of bacterial lysates. We are able to significantly improve purity of the final product and confirm the activity of the peptide. The process yields recombinant melittin that is effective when used to treat U-87 MG glioma cells and inhibits growth of the Gram-positive pathogenic bacterium Streptococcus pyogenes. We demonstrate a method of repeated extraction of the insoluble protein fraction with mild detergent at a low pH that is able to generate a yield of pure, soluble melittin of approximately 0.5 to 1 mg/L of E. coli culture. PMID:23926061

  7. Differential retention of 212Pb ions and insoluble particles in nasal mucosa of the rat.

    PubMed

    Greenhalgh, J R; Birchall, A; James, A C; Smith, H; Hodgson, A

    1982-06-01

    The time course of retention of 212Pb ions in ciliated nasal epithelium and of tagged insoluble particles, which served both as a deposition vector and marker for mucus, was measured in 13 rats by counting the head externally at 2 min intervals up to 100 min after deposition. On average, 70-75% of insoluble particles introduced onto ciliated epithelium in 3 microliters of distilled water were cleared to the gut with a half-time of approximately 15 min (range 6-35 min). A smaller fraction of lead ions (averaging about 60%) introduced in the same water sample was cleared to the gut with a half-time in each rat similar to that of particle clearance. Rapid uptake of about 8% of deposited 212Pb into blood was also observed. A compartment model consistent with the observed nasal retention and appearance of 212Pb in blood showed that, on average, 8% of deposited lead ions were transferred to the blood with a half-time of 15 min. For about 35% of the deposited lead ions and 25% of the particles, no clearance was detected up to 60-100 min after deposition. It is probable that a fraction of the lead ions are retained by epithelial tissue. PMID:7111392

  8. A minichaperone-based fusion system for producing insoluble proteins in soluble stable forms.

    PubMed

    Sharapova, Olga A; Yurkova, Maria S; Fedorov, Alexey N

    2016-02-01

    We have developed a fusion system for reliable production of insoluble hydrophobic proteins in soluble stable forms. A carrier is thermophilic minichaperone, GroEL apical domain (GrAD), a 15 kDa monomer able to bind diverse protein substrates. The Met-less variant of GrAD has been made for further convenient use of Met-specific CNBr chemical cleavage, if desired. The Met-less GrAD retained stability and solubility of the original protein. Target polypeptides can be fused to either C-terminus or N-terminus of GrAD. The system has been tested with two unrelated insoluble proteins fused to the C-terminus of GrAD. One of the proteins was also fused to GrAD N-terminus. The fusions formed inclusion bodies at 25°C and above and were partly soluble only at lower expression temperatures. Most importantly, however, after denaturation in urea, all fusions without exception were completely renatured in soluble stable forms that safely survived freezing-thawing as well as lyophilization. All fusions for both tested target proteins retained solubility at high concentrations for days. Functional analysis revealed that a target protein may retain functionality in the fusion. Convenience features include potential thermostability of GrAD fusions, capacity for chemical and enzymatic cleavage of a target and His6 tag for purification. PMID:26612097

  9. Characterisation of detergent-insoluble membranes in pollen tubes of Nicotiana tabacum (L.)

    PubMed Central

    Moscatelli, Alessandra; Gagliardi, Assunta; Maneta-Peyret, Lilly; Bini, Luca; Stroppa, Nadia; Onelli, Elisabetta; Landi, Claudia; Scali, Monica; Idilli, Aurora Irene; Moreau, Patrick

    2015-01-01

    ABSTRACT Pollen tubes are the vehicle for sperm cell delivery to the embryo sac during fertilisation of Angiosperms. They provide an intriguing model for unravelling mechanisms of growing to extremes. The asymmetric distribution of lipids and proteins in the pollen tube plasma membrane modulates ion fluxes and actin dynamics and is maintained by a delicate equilibrium between exocytosis and endocytosis. The structural constraints regulating polarised secretion and asymmetric protein distribution on the plasma membrane are mostly unknown. To address this problem, we investigated whether ordered membrane microdomains, namely membrane rafts, might contribute to sperm cell delivery. Detergent insoluble membranes, rich in sterols and sphingolipids, were isolated from tobacco pollen tubes. MALDI TOF/MS analysis revealed that actin, prohibitins and proteins involved in methylation reactions and in phosphoinositide pattern regulation are specifically present in pollen tube detergent insoluble membranes. Tubulins, voltage-dependent anion channels and proteins involved in membrane trafficking and signalling were also present. This paper reports the first evidence of membrane rafts in Angiosperm pollen tubes, opening new perspectives on the coordination of signal transduction, cytoskeleton dynamics and polarised secretion. PMID:25701665

  10. An automatic collector to monitor insoluble atmospheric deposition: application for mineral dust deposition

    NASA Astrophysics Data System (ADS)

    Laurent, B.; Losno, R.; Chevaillier, S.; Vincent, J.; Roullet, P.; Bon Nguyen, E.; Ouboulmane, N.; Triquet, S.; Fornier, M.; Raimbault, P.; Bergametti, G.

    2015-07-01

    Deposition is one of the key terms of the mineral dust cycle. However, dust deposition remains poorly constrained in transport models simulating the atmospheric dust cycle. This is mainly due to the limited number of relevant deposition measurements. This paper aims to present an automatic collector (CARAGA), specially developed to sample the total (dry and wet) atmospheric deposition of insoluble dust in remote areas. The autonomy of the CARAGA can range from 25 days to almost 1 year depending on the programmed sampling frequency (from 1 day to 2 weeks respectively). This collector is used to sample atmospheric deposition of Saharan dust on the Frioul islands in the Gulf of Lions in the Western Mediterranean. To quantify the mineral dust mass in deposition samples, a weighing and ignition protocol is applied. Almost 2 years of continuous deposition measurements performed on a weekly sampling basis on Frioul Island are presented and discussed with air mass trajectories and satellite observations of dust. Insoluble mineral deposition measured on Frioul Island was 2.45 g m-2 for February to December 2011 and 3.16 g m-2 for January to October 2012. Nine major mineral deposition events, measured during periods with significant MODIS aerosol optical depths, were associated with air masses coming from the southern Mediterranean Basin and North Africa.

  11. Long-wave Marangoni convection in a heated liquid layer with insoluble surfactant

    NASA Astrophysics Data System (ADS)

    Morozov, Matvey; Oron, Alex; Nepomnyashchy, Alexander

    2013-11-01

    Recently, long-wave Marangoni convection in a heated binary-liquid layer was considered by Podolny et al. (Phys. Fluids 18, 054104, 2006) revealing rich dynamics stemming from oscillatory instability. These results were obtained in the absence of surfactants. In the present work we investigate an opposite limit: a liquid layer with insoluble surfactant. We consider a liquid layer lying on a solid horizontal substrate with insoluble surfactant adsorbed at the deformable free surface. Convection is triggered by a given transverse temperature gradient. Long-wave linear stability analysis of the quiescent state of the layer reveals a competition between monotonic and oscillatory modes of instability. We derive nonlinear evolution equations governing the large-scale dynamics of the layer. Linear stability analysis of these equations indicates their applicability only in the case of oscillatory instability. We then carry out weakly nonlinear analysis in the vicinity of the oscillatory-instability threshold for the case of a 2D layer, and study corresponding pattern selection. Finally, we compare the analytical results with the numerical solutions of our nonlinear evolution equations. This work is supported by the European Union via FP7 Marie Curie scheme Grant PITN-GA-2008-214919 (MULTIFLOW).

  12. Gastrointestinal effects associated with soluble and insoluble copper in drinking water.

    PubMed Central

    Pizarro, F; Olivares, M; Araya, M; Gidi, V; Uauy, R

    2001-01-01

    The aim of this study was to determine whether total copper or soluble copper concentration is associated with gastrointestinal signs and symptoms. Forty-five healthy adult women (18-55 years of age), living in Santiago, Chile, ingested tap water with 5 mg/L of copper containing different ratios of soluble copper (copper sulfate) and insoluble copper (copper oxide) over a 9-week period. Three randomized sequences of the different copper ratios (0:5, 1:4, 2:3, 3:2, and 5:0 mg/L) were followed. Subjects recorded their water consumption and gastrointestinal symptoms daily on a special form. Mean water consumption was similar among groups. Serum copper levels, ceruloplasmin, and activities of liver enzymes were within normal limits. No differences were detected between the means of biochemical parameters at the beginning and at the end of the study. Twenty subjects presented gastrointestinal disturbances at least once during the study, 9 suffered diarrhea (with or without abdominal pain and vomiting), and the other 11 subjects reported abdominal pain, nausea, or vomiting. No differences were found in incidence of abdominal pain, nausea, vomiting, and diarrhea regardless of the ratio of copper sulfate to copper oxide. In conclusion, both copper sulfate (a soluble compound) and copper oxide (an insoluble compound) have comparable effects on the induction of gastrointestinal manifestations, implying that similar levels of ionic copper were present in the stomach. PMID:11673125

  13. Neuromelanins of Human Brain Have Soluble and Insoluble Components with Dolichols Attached to the Melanic Structure

    PubMed Central

    Engelen, Mireille; Vanna, Renzo; Bellei, Chiara; Zucca, Fabio A.; Wakamatsu, Kazumasa; Monzani, Enrico; Ito, Shosuke; Casella, Luigi; Zecca, Luigi

    2012-01-01

    Neuromelanins (NMs) are neuronal pigments of melanic-lipidic type which accumulate during aging. They are involved in protective and degenerative mechanisms depending on the cellular context, however their structures are still poorly understood. NMs from nine human brain areas were analyzed in detail. Elemental analysis led to identification of three types of NM, while infrared spectroscopy showed that NMs from neurons of substantia nigra and locus coeruleus, which selectively degenerate in Parkinson’s disease, have similar structure but different from NMs from brain regions not targeted by the disease. Synthetic melanins containing Fe and bovine serum albumin were prepared to model the natural product and help clarifying the structure of NMs. Extensive nuclear magnetic resonance spectroscopy studies showed the presence of dolichols both in the soluble and insoluble parts of NM. Diffusion measurements demonstrated that the dimethyl sulfoxide soluble components consist of oligomeric precursors with MWs in the range 1.4–52 kDa, while the insoluble part contains polymers of larger size but with a similar composition. These data suggest that the selective vulnerability of neurons of substantia nigra and locus coeruleus in Parkinson’s disease might depend on the structure of the pigment. Moreover, they allow to propose a pathway for NM biosynthesis in human brain. PMID:23139786

  14. Catalytic Efficiency of Chitinase-D on Insoluble Chitinous Substrates Was Improved by Fusing Auxiliary Domains

    PubMed Central

    Madhuprakash, Jogi; El Gueddari, Nour Eddine; Moerschbacher, Bruno M.; Podile, Appa Rao

    2015-01-01

    Chitin is an abundant renewable polysaccharide, next only to cellulose. Chitinases are important for effective utilization of this biopolymer. Chitinase D from Serratia proteamaculans (SpChiD) is a single domain chitinase with both hydrolytic and transglycosylation (TG) activities. SpChiD had less of hydrolytic activity on insoluble polymeric chitin substrates due to the absence of auxiliary binding domains. We improved catalytic efficiency of SpChiD in degradation of insoluble chitin substrates by fusing with auxiliary domains like polycystic kidney disease (PKD) domain and chitin binding protein 21 (CBP21). Of the six different SpChiD fusion chimeras, two C-terminal fusions viz. ChiD+PKD and ChiD+CBP resulted in improved hydrolytic activity on α- and β-chitin, respectively. Time-course degradation of colloidal chitin also confirmed that these two C-terminal SpChiD fusion chimeras were more active than other chimeras. More TG products were produced for a longer duration by the fusion chimeras ChiD+PKD and PKD+ChiD+CBP. PMID:25615694

  15. Sulfated modification, characterization and property of a water-insoluble polysaccharide from Ganoderma atrum.

    PubMed

    Zhang, Hui; Wang, Jun-Qiao; Nie, Shao-Ping; Wang, Yuan-Xing; Cui, Steve W; Xie, Ming-Yong

    2015-08-01

    Sulfated modification was carried out to modify a water-insoluble polysaccharide from Ganoderma atrum (AGAP). The effects of sulfation on structure, physicochemical and functional properties of AGAP were investigated. Three sulfated derivatives were prepared, designated as S-1, S-2 and S-3 with degree of substitution (DS) of 0.35, 0.74 and 1.14, respectively. AGAP was elucidated as an α-(1→3)-glucan with few branches terminated by single mannose or xylose residues. The molecular weight (Mw) and radius of gyration (Rg) were estimated to be 1665 kDa and 65.49 nm, respectively. After sulfated modification, non-selective sulfation occurred preferably at O-6, partially at O-2 and O-4 positions of the glucosyl residues. The water-solubility of the derivatives was significantly improved in a DS-dependent manner. Mw of the derivatives showed a sharp decrease, and the chain conformation was estimated to be expanded stiff in phosphate buffer. In vitro tests showed that sulfated modification improved its antioxidant activities and anti-proliferative ability against S-180 tumor cells. This study suggested that sulfated modification was an effective approach to improve the water-solubility and functional properties of insoluble polysaccharides. PMID:25957721

  16. Rescue from tau-induced neuronal dysfunction produces insoluble tau oligomers

    PubMed Central

    Cowan, Catherine M.; Quraishe, Shmma; Hands, Sarah; Sealey, Megan; Mahajan, Sumeet; Allan, Douglas W.; Mudher, Amritpal

    2015-01-01

    Aggregation of highly phosphorylated tau is a hallmark of Alzheimer’s disease and other tauopathies. Nevertheless, animal models demonstrate that tau-mediated dysfunction/toxicity may not require large tau aggregates but instead may be caused by soluble hyper-phosphorylated tau or by small tau oligomers. Challenging this widely held view, we use multiple techniques to show that insoluble tau oligomers form in conditions where tau-mediated dysfunction is rescued in vivo. This shows that tau oligomers are not necessarily always toxic. Furthermore, their formation correlates with increased tau levels, caused intriguingly, by either pharmacological or genetic inhibition of tau kinase glycogen-synthase-kinase-3beta (GSK-3β). Moreover, contrary to common belief, these tau oligomers were neither highly phosphorylated, and nor did they contain beta-pleated sheet structure. This may explain their lack of toxicity. Our study makes the novel observation that tau also forms non-toxic insoluble oligomers in vivo in addition to toxic oligomers, which have been reported by others. Whether these are inert or actively protective remains to be established. Nevertheless, this has wide implications for emerging therapeutic strategies such as those that target dissolution of tau oligomers as they may be ineffective or even counterproductive unless they act on the relevant toxic oligomeric tau species. PMID:26608845

  17. Catalysis at the toulene/water interface: Octadecyl immobilized H-ZSM-5 catalyst promoted hydrolysis of water-insoluble esters

    SciTech Connect

    Ogawa, Haruo; Koh, Tensai ); Taya, Kazuo ); Chihara, Teiji , Wako )

    1994-08-01

    Octadecyltrichorosilane-treated H-ZSM-5, abbreviated as H-ZSM-5-C[sub 18] resulted in an effective catalyst for the hydrolysis of water-insoluble esters in toluene-water solvent system. These floated at the interface of the two liquids. The H-ZSM-5-C[sub 18] catalyst showed ca. 60 times the activity of H-ZSM-5 for the hydrolysis of dodecyl acetate. Acid strength of H-ZSM-5 in water (-5.6 < Ho [<=] -3.0) was maintained even after the treatment with octadecyltrichlorosilane. The treatment renders H-ZSM-5 lipophylicity and provides a quasi-lipid phase on the surface. The shape-selective properties of H-ZSM-5-C[sub 18] catalyst were observed for the hydrolysis of aliphatic esters with straight chains. 17 refs., 9 figs., 6 tabs.

  18. Solar driven nitrous acid formation on building material surfaces containing titanium dioxide: A concern for air quality in urban areas?

    NASA Astrophysics Data System (ADS)

    Langridge, Justin M.; Gustafsson, R. Joel; Griffiths, Paul T.; Cox, R. Anthony; Lambert, Richard M.; Jones, Roderic L.

    The photoenhanced uptake of nitrogen dioxide (NO 2) to the surface of commercially available self-cleaning window glass has been studied under controlled laboratory conditions. This material is one of an array of modern building products which incorporate titanium dioxide (TiO 2) nanoparticles and are finding increasing use in populated urban areas. Amongst the principal drivers for the use of these materials is that they are thought to facilitate the irreversible removal of pollutants such as NO 2 and organic molecules from the atmosphere and thus act to remediate air quality. While it appears that TiO 2 materials do indeed remove organic molecules from built environments, in this study we show that the photoenhanced uptake of NO 2 to one example material, self-cleaning window glass, is in fact accompanied by the substantial formation (50-70%) of gaseous nitrous acid (HONO). This finding has direct and serious implications for the use of these materials in urban areas. Not only is HONO a harmful respiratory irritant, it is also readily photolysed by solar radiation leading to the formation of hydroxyl radicals (OH) together with the re-release of NO x as NO. The net effect of subsequent OH initiated chemistry can then be the further degradation of air quality through the formation of secondary pollutants such as ozone and VOC oxidation products. In summary, we suggest that a scientifically conceived technical strategy for air quality remediation based on this technology, while widely perceived as universally beneficial, could in fact have effects precisely opposite to those intended.

  19. Temperature Shifts for Extraction and Purification of Zygomycetes Chitosan with Dilute Sulfuric Acid

    PubMed Central

    Zamani, Akram; Edebo, Lars; Niklasson, Claes; Taherzadeh, Mohammad J.

    2010-01-01

    The temperature-dependent hydrolysis and solubility of chitosan in sulfuric acid solutions offer the possibility for chitosan extraction from zygomycetes mycelia and separation from other cellular ingredients with high purity and high recovery. In this study, Rhizomucor pusillus biomass was initially extracted with 0.5 M NaOH at 120 °C for 20 min, leaving an alkali insoluble material (AIM) rich in chitosan. Then, the AIM was subjected to two steps treatment with 72 mM sulfuric acid at (i) room temperature for 10 min followed by (ii) 120 °C for 45 min. During the first step, phosphate of the AIM was released into the acid solution and separated from the chitosan-rich residue by centrifugation. In the second step, the residual AIM was re-suspended in fresh 72 mM sulfuric acid, heated at 120 °C and hot filtered, whereby chitosan was extracted and separated from the hot alkali and acid insoluble material (HAAIM). The chitosan was recovered from the acid solution by precipitation at lowered temperature and raised pH to 8–10. The treatment resulted in 0.34 g chitosan and 0.16 g HAAIM from each gram AIM. At the start, the AIM contained at least 17% phosphate, whereas after the purification, the corresponding phosphate content of the obtained chitosan was just 1%. The purity of this chitosan was higher than 83%. The AIM subjected directly to the treatment with hot sulfuric acid (at 120 °C for 45 min) resulted in a chitosan with a phosphate impurity of 18.5%. PMID:21152285

  20. Corrosion resistance and behavior of construction materials exposed to dilute sulfuric acid at elevated temperatures under static conditions

    SciTech Connect

    Nguyen, D.T.

    1994-10-01

    Laboratory investigation has been undertaken to determine the electrochemical behavior and corrosion resistance of various construction materials in a simulated hydrolysis environment (5 wt % sulfuric acid) at temperatures ranging from 90 to 220C. Tests were performed in an autoclave-type electrochemical cell. The corrosion behavior of the test materials was determined using computer-controlled DC potentiodynamic polarization. Corrosion rates of the test materials were determined using AC impedance techniques. Among the stainless steels tested, only alloy N08026 (Carpenter 20Mo-6) performed satisfactory up to a temperature of 100C. The alloy passivated spontaneously in the environment and corroded at a rate of less than 2 mpy. None of the stainless steels tested could be used at 120{degrees}C or above. A number of nickel-based alloys tested had good corrosion resistance up to 100C, but their corrosion rate exceeded 2 mpy at higher temperatures. Zirconium alloys were satisfactory up to 180C. Only tantalum and a tantalum-niobium alloy were satisfactory up to 220C.

  1. Poly(lactic acid)/TiO₂ nanocomposites as alternative biocidal and antifungal materials.

    PubMed

    Fonseca, Carmen; Ochoa, Almudena; Ulloa, Maria Teresa; Alvarez, Eduardo; Canales, Daniel; Zapata, Paula A

    2015-12-01

    Poly(lactic acid) (PLA) composites with titanium oxide (TiO2) ~10-nm nanoparticles were produced by the melting process and their main properties were evaluated. The nanoparticles are homogeneously dispersed in the matrix with a low degree of agglomeration, as seen by transmission electron microscopy (TEM). The crystallinity temperature increased ~12% when 5 wt.% of TiO2 was added, showing that the nanoparticles acted as nucleating agents this trend was confirmed by optical images. The elastic modulus increased ~54% compared to neat PLA at 5 wt.% of nanoparticles. Despite these improvements, PLA/TiO2 nanocomposites showed lower shear viscosity than neat PLA, possibly reflecting degradation of the polymer due to the particles. Regarding biocidal properties, after 2h of contact the PLA/TiO2 composites with 8 wt.% TiO2 showed a reduction of Escherichia coli colonies of ~82% under no UVA irradiation compared to pure PLA. This biocidal characteristic can be increased under UVA irradiation, with nanocomposites containing 8 wt.% TiO2 killing 94% of the bacteria. The PLA/TiO2 nanocomposites with 8 wt.% were also 99.99% effective against Aspergillus fumigatus under the UVA irradiation. PMID:26354270

  2. Polypropylene Glycol-Silver Nanoparticle Composites: A Novel Anticorrosion Material for Aluminum in Acid Medium

    NASA Astrophysics Data System (ADS)

    Solomon, Moses M.; Umoren, Saviour A.; Israel, Aniekemeabasi U.; Ebenso, Eno E.

    2015-11-01

    Admixture of polypropylene glycol and 1 mM AgNO3 together with natural honey as reducing and stabilizing agent was employed to prepare in situ polypropylene glycol/silver nanoparticle (PPG/AgNPs) composite. The prepared PPG/AgNPs composite was characterized by UV-Vis spectroscopy, FTIR, XRD, and EDS, while the morphology of the Ag nanoparticles in the composite was obtained by TEM. TEM results revealed that the Ag nanoparticles were spherical in shape. The anticorrosion property of PPG/AgNPs composite was examined by electrochemical, weight loss, SEM, EDS, and water contact angle measurements. Results obtained show that PPG/AgNPs are effective in retarding the dissolution of Al in an acid-induced corrosive environment. Inhibition efficiency increased with the increasing composite concentration but decreased with the increasing temperature. Potentiodynamic polarization results revealed that PPG/AgNPs functions as a mixed-type corrosion inhibitor. The adsorption of the composite onto Al surface was found to follow El-Awady et al. adsorption isotherm model. SEM, EDS, and water contact angle results confirmed the adsorption of PPG/AgNPs films onto Al surface.

  3. Inhibition of Paenibacillus larvae by lactic acid bacteria isolated from fermented materials.

    PubMed

    Yoshiyama, Mikio; Wu, Meihua; Sugimura, Yuya; Takaya, Noriko; Kimoto-Nira, Hiromi; Suzuki, Chise

    2013-01-01

    We evaluated the potential application of lactic acid bacteria (LAB) isolated from fermented feeds and foods for use as probiotics against Paenibacillus larvae, the causal agent of American foulbrood (AFB) in vitro. We also assessed the ability of LAB to induce the expression of antimicrobial peptide genes in vivo. Screening of the 208 LAB isolated from fermented feeds and foods revealed that nine strains inhibited the in vitro growth of P. larvae. The LAB strains were identified by 16S rRNA gene sequencing as Enterococcus sp., Weissella sp. and Lactobacillus sp. These strains were screened for their abilities of immune activation in honeybees by real-time RT-PCR using antimicrobial peptide genes as markers. After oral administration of several of the screened LAB to larvae and adults, the transcription levels of antimicrobial peptide genes, such as abaecin, defensin and hymenoptaecin, were found to increase significantly. These findings suggested that selected LAB stimulate the innate immune response in honeybees, which may be useful for preventing bacterial diseases in honeybees. This is the first report to characterize the probiotic effects of LAB isolated from fermented feeds and foods in honeybees. PMID:23000777

  4. The initiation of material corrosion in semicritical and supercritical aqueous hydrochloric acid solutions

    SciTech Connect

    Boukis, N.; Kritzer, P.; Schacht, M.; Dinjus, E.

    1999-11-01

    In recent years, a lot of work has been performed to interpret corrosion during the process of supercritical water oxidation (SCWO). For a better understanding of the corrosion mechanisms, the initiation processes of corrosion have to be known. The corrosion resistance of two alumina ceramics and sapphire in hydrochloric acid (HCl) solutions was investigated at T = 240 C -- 500 C and p = 27 MPa. For the alumina ceramics, intergranular corrosion and dissolution of the grains were identified as corrosion mechanisms. The corrosion experiments with the nickel-base alloy 625 (UNS N06625) and its main constituents nickel, chromium, and molybdenum were performed in oxygenated HCl solutions at T = 350 C and p = 24 MPa. Nickel and molybdenum showed severe weight loss after only 5 h of reaction. The attack on chromium started with grain boundary etching and proceeded via the formation of thick, spalling oxide layers on the surface. Initial corrosion phenomena observed on alloy 625 were intergranular attack and pit formation. At longer reaction times, a complete surface attack was observed.

  5. Fluoride toothpaste containing 1.5% arginine and insoluble calcium as a new standard of care in caries prevention.

    PubMed

    ten Cate, J M; Cummins, D

    2013-01-01

    In spite of obvious achievements in prevention, caries remains a prevalent disease. Fluorides are effective by inhibiting enamel and dentin demineralization and enhancing remineralization, but have little or no influence on bacterial processes in dental plaque. Dental caries is a continuum of stages from reversible, early lesions to irreversible, pre-cavitated lesions and, ultimately, to cavities. Prevention should focus on strengthening protective and reducing pathological factors, and careful monitoring of the disease state. While fluoride and the mineral aspects of caries have been in focus for decades, new insights into the etiology of caries have generated novel concepts and approaches to its prevention and treatment. The observation that some plaque bacteria can produce alkali metabolites and, thus, raise pH or neutralize acid formed in plaque has long been known. Such pH rise factors are related to caries susceptibility. Nourishing the plaque with substrates that encourage alkali-producing reactions is a protective factor in the caries continuum. This article reviews the results of clinical studies with a novel toothpaste containing 1.5% arginine, an insoluble calcium compound, and fluoride which have demonstrated superior remineralization of white spot enamel lesions and rehardening of root surface lesions, favorable effects on the de-/remineralization balance, as well as superior cavity prevention efficacy compared to toothpaste with fluoride alone. Studies have also confirmed formation of ammonia and elevated pH levels in subjects using the arginine-containing toothpaste. This novel toothpaste effectively combines the established effects of fluoride on de- and remineralization with reduction of caries-inducing pathological factors resulting from plaque metabolism. PMID:24660269

  6. Boric Acid Assisted Reduction of Graphene Oxide: A Promising Material for Sodium-Ion Batteries.

    PubMed

    Wang, Ying; Wang, Caiyun; Wang, Yijing; Liu, Huakun; Huang, Zhenguo

    2016-07-27

    Reduced graphene oxide, an intensively investigated material for Li-ion batteries, has shown mostly unsatisfactory performance in Na-ion batteries, since its d-spacing is believed to be too small for effective insertion/deinsertion of Na(+) ions. Herein, a facile method was developed to produce boron-functionalized reduced graphene oxide (BF-rGO), with an enlarged interlayer spacing and defect-rich structure, which effectively accommodates the sodiation/desodiation and provides more active sites. The Na/BF-rGO half cells exhibit unprecedented long cycling stability, with ∼89.4% capacity retained after 5000 cycles (0.002% capacity decay per cycle) at 1000 mA·g(-1) current density. High specific capacity (280 mAh·g(-1)) and great rate capability were also delivered in the Na/BF-rGO half cells. PMID:27349132

  7. Functional Material Features of Bombyx mori Silk Light vs. Heavy Chain Proteins

    PubMed Central

    Zafar, Muhammad S.; Belton, David J.; Hanby, Benjamin; Kaplan, David L.; Perry, Carole C.

    2016-01-01

    Bombyx mori (BM) silk fibroin is composed of two different subunits; heavy chain and light chain fibroin linked by a covalent disulphide bond. Current methods of separating the two silk fractions is complicated and produces inadequate quantities of the isolated components for the study of the individual light and heavy chain silks with respect to new materials. We report a simple method of separating silk fractions using formic acid. The formic acid treatment partially releases predominately the light chain fragment (soluble fraction) and then the soluble fraction and insoluble fractions can be converted into new materials. The regenerated original (total) silk fibroin and the separated fractions (soluble vs. insoluble) had different molecular weights and showed distinctive pH stabilities against aggregation/precipitation based on particle charging. All silk fractions could be electrospun to give fibre mats with viscosity of the regenerated fractions being the controlling factor for successful electrospinning. The silk fractions could be mixed to give blends with different proportions of the two fractions to modify the diameter and uniformity of the electrospun fibres formed. The soluble fraction containing the light chain was able to modify the viscosity by thinning the insoluble fraction containing heavy chain fragments, perhaps analogous to its role in natural fibre formation where the light chain provides increased mobility and the heavy chain producing shear thickening effects. The simplicity of this new separation method should enable access to these different silk protein fractions and accelerate the identification of methods, modifications and potential applications of these materials in biomedical and industrial applications. PMID:25565556

  8. Graphene nanosheets-polypyrrole hybrid material as a highly active catalyst support for formic acid electro-oxidation.

    PubMed

    Yang, Sudong; Shen, Chengmin; Liang, Yanyu; Tong, Hao; He, Wei; Shi, Xuezhao; Zhang, Xiaogang; Gao, Hong-jun

    2011-08-01

    A novel electrode material based on graphene oxide (GO)-polypyrrole (PPy) composites was synthesized by in situ chemical oxidation polymerization. Palladium nanoparticles (NPs) with a diameter of 4.0 nm were loaded on the reduced graphene oxide(RGO)-PPy composites by a microwave-assisted polyol process. Microstructure analysis showed that a layer of coated PPy film with monodisperse Pd NPs is present on the RGO surface. The Pd/RGO-PPy catalysts exhibit excellent catalytic activity and stability for formic acid electro-oxidation when the weight feed ratio of GO to pyrrole monomer is 2:1. The superior performance of Pd/RGO-PPy catalysts may arise from utilization of heterogeneous nucleation sites for NPs and the greatly increased electronic conductivity of the supports. PMID:21713273

  9. Carboxylic acid-grafted mesoporous material and its high catalytic activity in one-pot three-component coupling reaction

    SciTech Connect

    Gomes, Ruth; Bhaumik, Asim; Dutta, Saikat

    2014-11-01

    A new carboxylic acid functionalized mesoporous organic polymer has been synthesized via in situ radical polymerization of divinylbenzene and acrylic acid using a mesoporous silica as a seed during the polymerization process under solvothermal conditions. The mesoporous material MPDVAA-1 has been thoroughly characterized employing powder XRD, solid state {sup 13}C cross polarization magic angle spinning-nuclear magnetic resonance, FT-IR spectroscopy, N{sub 2} sorption, HR-TEM, and NH{sub 3} temperature programmed desorption-thermal conductivity detector (TPD-TCD) analysis to understand its porosity, chemical environment, bonding, and surface properties. The mesoporous polymer was used as a catalyst for a three comp onent Biginelli condensation between various aldehydes, β-keto esters, and urea/thioureas to give 3,4-dihydropyrimidine-2(1H)-ones. The reactions were carried out under conventional heating as well as solvent-free microwave irradiation of solid components, and in both the cases, the mesoporous polymer MPDVAA-1 proved to be a powerful, robust, and reusable catalyst with high catalytic efficiency.

  10. Effect of plate preparation on active-material utilization and cycleability of positive plates in automotive lead/acid batteries

    NASA Astrophysics Data System (ADS)

    Ozgun, H.; Lam, L. T.; Rand, D. A. J.; Bhargava, S. K.

    The power demands from automotive lead/acid batteries are rising steadily with the increasing number of electronic accessories that are being fitted to modern vehicles. In order to meet new levels of performance, automotive batteries have been redesigned to use low-ohmic microporous separators, as well as thinner plates (to increase the number of plates per cell) that are made with a low paste density. This approach, however, has led to a separate problem, namely, an appreciable reduction in battery service life. To redress this situation, a research programme has been implemented in our laboratories to examine, in detail, the effect of plate preparation on the active-material utilization and cycleability of automotive positive plates with grids made from low-antimony alloy. The cycleability is evaluated in terms of repetitive reserve-capacity. The results suggest that a paste formula with a combination of high density and low acid-to-oxide ratio is the most appropriate technology for the production of the thin positive plates that are required in advanced designs of automotive batteries.

  11. Carboxylic acid-grafted mesoporous material and its high catalytic activity in one-pot three-component coupling reaction

    NASA Astrophysics Data System (ADS)

    Gomes, Ruth; Dutta, Saikat; Bhaumik, Asim

    2014-11-01

    A new carboxylic acid functionalized mesoporous organic polymer has been synthesized via in situ radical polymerization of divinylbenzene and acrylic acid using a mesoporous silica as a seed during the polymerization process under solvothermal conditions. The mesoporous material MPDVAA-1 has been thoroughly characterized employing powder XRD, solid state 13C cross polarization magic angle spinning-nuclear magnetic resonance, FT-IR spectroscopy, N2 sorption, HR-TEM, and NH3 temperature programmed desorption-thermal conductivity detector (TPD-TCD) analysis to understand its porosity, chemical environment, bonding, and surface properties. The mesoporous polymer was used as a catalyst for a three comp onent Biginelli condensation between various aldehydes, β-keto esters, and urea/thioureas to give 3,4-dihydropyrimidine-2(1H)-ones. The reactions were carried out under conventional heating as well as solvent-free microwave irradiation of solid components, and in both the cases, the mesoporous polymer MPDVAA-1 proved to be a powerful, robust, and reusable catalyst with high catalytic efficiency.

  12. Organic solvent-tolerant elastase efficiently hydrolyzes insoluble, cross-linked, protein fiber of eggshell membranes.

    PubMed

    Takenaka, Shinji; Hano, Shinpei; Cheng, Minyi; Yoshida, Ken-ichi; Aoki, Kenji

    2012-05-01

    Eggshell membrane is a mechanically stable and insoluble cross-linked fibrous protein. Pseudomonas aeruginosa strain ME-4 synthesizes a metalloprotease that degrades the eggshell membrane. We cloned the encoding gene in Escherichia coli. The recombinant protease, over-expressed in E. coli, was inactive but addition of acetone to crude cell extracts restored the activity and removed many E. coli proteins. We purified the active, acetone-treated protease to homogeneity in a single chromatography step with 57% recovery. The recombinant protease partially hydrolyzed eggshell membrane and produced more soluble peptides and proteins than commercial elastase, α-chymotrypsin, and collagenase. The soluble peptides produced from hydrolyzed eggshell membrane inhibited angiotensin-I-converting enzyme activity. The degradation of eggshell membrane by the recombinant elastase could be applied to the production of soluble bioactive peptides. PMID:22286207

  13. Derivation of a continuum model and the energy law for moving contact lines with insoluble surfactants

    SciTech Connect

    Zhang, Zhen Xu, Shixin; Ren, Weiqing

    2014-06-15

    A continuous model is derived for the dynamics of two immiscible fluids with moving contact lines and insoluble surfactants based on thermodynamic principles. The continuum model consists of the Navier-Stokes equations for the dynamics of the two fluids and a convection-diffusion equation for the evolution of the surfactant on the fluid interface. The interface condition, the boundary condition for the slip velocity, and the condition for the dynamic contact angle are derived from the consideration of energy dissipations. Different types of energy dissipations, including the viscous dissipation, the dissipations on the solid wall and at the contact line, as well as the dissipation due to the diffusion of surfactant, are identified from the analysis. A finite element method is developed for the continuum model. Numerical experiments are performed to demonstrate the influence of surfactant on the contact line dynamics. The different types of energy dissipations are compared numerically.

  14. Stabilization of Boiling Nuclei by Insoluble Gas: Can a Nanobubble Cloud Exist?

    PubMed

    Yarom, Michal; Marmur, Abraham

    2015-07-21

    Liquid boiling that starts off with an insoluble gas bubble is thermodynamically analyzed. This case is an idealization of very low gas solubility and very slow diffusion of this gas in the boiling liquid. The analysis is made for a spherical, freely suspended bubble as well as for a bubble attached to a solid surface. The results predict the spontaneous formation of a stable, critical bubble at pressures higher than the saturation pressure. Stable critical radii are also predicted for pressures lower than the saturation pressure but in addition to unstable, larger critical bubbles. These bubbles are affected by the presence and nature of a solid surface. The present analysis provides a basis for a feasible explanation of the long-debated, long-time stability of nanobubbles. PMID:26121215

  15. Brain Targeting of a Water Insoluble Antipsychotic Drug Haloperidol via the Intranasal Route Using PAMAM Dendrimer.

    PubMed

    Katare, Yogesh K; Daya, Ritesh P; Sookram Gray, Christal; Luckham, Roger E; Bhandari, Jayant; Chauhan, Abhay S; Mishra, Ram K

    2015-09-01

    Delivery of therapeutics to the brain is challenging because many organic molecules have inadequate aqueous solubility and limited bioavailability. We investigated the efficiency of a dendrimer-based formulation of a poorly aqueous soluble drug, haloperidol, in targeting the brain via intranasal and intraperitoneal administration. Aqueous solubility of haloperidol was increased by more than 100-fold in the developed formulation. Formulation was assessed via different routes of administration for behavioral (cataleptic and locomotor) responses, and for haloperidol distribution in plasma and brain tissues. Dendrimer-based formulation showed significantly higher distribution of haloperidol in the brain and plasma compared to a control formulation of haloperidol administered via intraperitoneal injection. Additionally, 6.7 times lower doses of the dendrimer-haloperidol formulation administered via the intranasal route produced behavioral responses that were comparable to those induced by haloperidol formulations administered via intraperitoneal injection. This study demonstrates the potential of dendrimer in improving the delivery of water insoluble drugs to brain. PMID:26226403

  16. Bacterial cadherin domains as carbohydrate binding modules: determination of affinity constants to insoluble complex polysaccharides.

    PubMed

    Fraiberg, Milana; Borovok, Ilya; Weiner, Ronald M; Lamed, Raphael; Bayer, Edward A

    2012-01-01

    Cadherin (CA) and cadherin-like (CADG) doublet domains from the complex polysaccharide-degrading marine bacterium, Saccharophagus degradans 2-40, demonstrated reversible calcium-dependent binding to different complex polysaccharides, which serve as growth substrates for the bacterium. Here we describe a procedure based on adsorption of CA and CADG doublet domains to different insoluble complex polysaccharides, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) for visualizing and quantifying the distribution of cadherins between the bound and unbound fractions. Scatchard plots were employed to determine the kinetics of interactions of CA and CADG with several complex carbohydrates. On the basis of these binding studies, the CA and CADG doublet domains are proposed to form a new family of carbohydrate-binding module (CBM). PMID:22843394

  17. Insoluble Fiber in Young Barley Leaf Suppresses the Increment of Postprandial Blood Glucose Level by Increasing the Digesta Viscosity

    PubMed Central

    Kamiya, Tomoyasu; Tomozawa, Hiroshi; Ueno, Shiori; Tsubata, Masahito; Ikeguchi, Motoya; Takagaki, Kinya; Okushima, Ayaka; Miyata, Yu; Tamaru, Shizuka; Tanaka, Kazunari; Takahashi, Toru

    2013-01-01

    Barley (Hordeum vulgare L.) is a well-known cereal plant. Young barley leaf is consumed as a popular green-colored drink, which is named “Aojiru” in Japan. We examined the effects of barley leaf powder (BLP) and insoluble fibers derived from BLP on postprandial blood glucose in rats and healthy Japanese volunteers. BLP and insoluble fibers derived from BLP suppressed the increment of postprandial blood glucose levels in rats (P < 0.01), and increased the viscosity of their digesta. The insoluble fibers present in BLP might play a role in controlling blood glucose level by increasing digesta viscosity. In human, BLP suppressed the increment of postprandial blood glucose level only in those which exhibited higher blood glucose levels after meals (P < 0.01). BLP might suppress the increment of postprandial blood glucose level by increasing digesta viscosity in both of rats and humans who require blood glucose monitoring. PMID:24348688

  18. Development of a novel environmentally friendly electropolymerization of water-insoluble monomers in aqueous electrolytes using acoustic emulsification.

    PubMed

    Asami, Ryosuke; Fuchigami, Toshio; Atobe, Mahito

    2006-11-21

    Electropolymerization of water-insoluble monomers, such as 3,4-ethylenedioxythiophene (EDOT), 3,4-dimethylthiophene (3,4-DiMeTh), 3-methylthiophene (3-MeTh), and 3-ethylthiophene (3-EtTh), proceeded successfully in aqueous electrolytes using acoustic emulsification. Ultrasonication to the water-insoluble monomer/aqueous electrolyte mixtures allowed the formation of very stable emulsions having the characteristic of giving narrow monomer droplet size distributions in the submicrometer range in aqueous electrolytes without added surfactants, and the smooth electropolymerization in the emulsions took place via direct electron transfer between the electrode and the water-insoluble monomer droplets. In this kind of electron-transfer system, the supporting electrolyte should be dissolved not only in the aqueous phase but also in the monomer droplets and contribute to the formation of an electric bilayer inside the droplets. The properties of a polymer EDOT film obtained by the present method were also investigated. PMID:17107030

  19. Genetic analysis of chromosomal loci affecting the content of insoluble glutenin in common wheat.

    PubMed

    Jin, Huaibing; Wang, Zhaojun; Li, Da; Wu, Peipei; Dong, Zhengying; Rong, Chaowu; Liu, Xin; Qin, Huanju; Li, Huili; Wang, Daowen; Zhang, Kunpu

    2015-09-20

    In common wheat, insoluble glutenin (IG) is an important fraction of flour glutenin macropolymers, and insoluble glutenin content (IGC) is positively associated with key end-use quality parameters. Here, we present a genetic analysis of the chromosomal loci affecting IGC with the data collected from 90 common wheat varieties cultivated in four environments. Statistical analysis showed that IGC was controlled mainly genetically and influenced by the environment. Among the major genetic components known to affect end-use quality, 1BL/1RS translocation had a significantly negative effect on IGC across all four environments. As to the different alleles of Glu-A1, -B1 and -D1 loci, Glu-A1a, Glu-B1b and Glu-D1d exhibited relatively strong positive effects on IGC in all environments. To identify new loci affecting IGC, association mapping with 1355 DArT markers was conducted. A total of 133 markers were found associated with IGC in two or more environments (P < 0.05), ten of which consistently affected IGC in all four environments. The phenotypic variance explained by the ten markers varied from 4.66% to 8.03%, and their elite alleles performed significantly better than the inferior counterparts in enhancing IGC. Among the ten markers, wPt-3743 and wPt-733835 reflected the action of Glu-D1, and wPt-664972 probably indicated the effect of Glu-A1. The other seven markers, forming three clusters on 2AL, 3BL or 7BL chromosome arms, represented newly identified genetic determinants of IGC. Our work provided novel insights into the genetic control of IGC, which may facilitate wheat end-use quality improvement through molecular breeding in the future. PMID:26408094

  20. Spatial distribution and potential sources of trace metals in insoluble particles of snow from Urumqi, China.

    PubMed

    Li, Xiaolan; Jiang, Fengqing; Wang, Shaoping; Turdi, Muyesser; Zhang, Zhaoyong

    2015-01-01

    The purpose of this work is to characterize trace elements in snow in urban-suburb gradient over Urumqi city, China. The spatial distribution patterns of 11 trace metals in insoluble particulate matters of snow were revealed by using 102 snow samples collected in and around urban areas of Urumqi, a city suffering from severe wintertime air pollution in China. Similar spatial distribution for Mn, Cu, Zn, Ni, and Pb was found and their two significant high-value areas located in the west and east, respectively, and a high-value area in the south, which were correlated with factory emissions, traffic activities, and construction fugitive dust. The high-value areas of Cr, Ni, and V occurred in the northeast corner and along main traffic paths, which were linked to oil refinery and vehicular emissions. High value of Be presented in the west of the city. The high-value area of Co in the northeast could be related to local soil. Cd and U displayed relatively even spatial patterns in the urban area. In view of distance from the urban center, e.g., from the first circular belt to the fourth circular belt, except Be, V, Cd, and U, the contents of other metals generally decreased from the first circular belt to the forth circular belt, implying the effect of human activity clearly. Additionally, prevailing northwesterly winds and occasionally southeasterly winds in winter were associated with decreased, generally, concentrations of trace metal in snow from the urban center to the southern suburb along a northwest and southeast transect. The information on concentrations and spatial distributions of these metals in insoluble particles of snow in winter will be valuable for further environmental protection and planning. PMID:25412892

  1. High insoluble fibre content increases in vitro starch digestibility in partially baked breads.

    PubMed

    Ronda, Felicidad; Rivero, Pablo; Caballero, Pedro A; Quilez, Joan

    2012-12-01

    Wheat breads prepared from frozen partially baked breads were characterized by their content of rapidly digestible starch (RDS) and slowly digestible starch (SDS) by the in vitro starch digestibility method developed by Englyst. Breads with different contents and types of fibre and breads prepared with different fermentation processes were studied. Bread with inulin and with a double fermentation had the lowest RDS content of 58.8 ± 1.7 and 60.0 ± 1.9 (% dry matter), respectively. Wheat bran bread, seeded bread, triple fermentation white bread and baguette-type bread showed values of RDS between 63.1 ± 1.7 and 65.7 ± 1.7 with no significant differences between them (p < 0.05). The fraction of SDS was higher in wheat breads than in breads with added fibre. The highest values of the starch digestive rate index (SDRI) were obtained by the three types of breads with added fibre, which ranged from 91.8 ± 3.5 to 95.8 ± 3.5 versus 80.2 ± 3.5 to 87.5 ± 3.5 for white wheat breads. A significant (p < 0.01) positive linear correlation between the insoluble fibre content and SDRI was obtained (R² = 0.96). Insoluble fibre dilutes and disrupts gluten network and probably weakens the interaction between gluten and starch, which protects starch from digestive enzymes action. Scanning electronic microscopy microstructure of bread crumbs corroborated this statement. PMID:22621760

  2. Speciation measurements by HPLC-HGAAS of dimethylarsinic acid and arsenobetaine in three candidate lyophilized urine reference materials.

    PubMed

    Cornelis, R; Zhang, X; Mees, L; Christensen, J M; Byrialsen, K; Dyrschel, C

    1998-12-01

    Speciation measurements of dimethylarsinic acid (DMA) and arsenobetaine (AsB) in three candidate lyophilized urine reference materials are described. The measurements were based on cation-exchange liquid chromatography coupled to hydride generation atomic absorption spectrometry with on-line digestion of the organic. As species by alkaline persulfate solution aided by ultraviolet radiation. Arsenic concentrations as DMA were significantly different in the three samples. The mean values for the three samples were 4.1 +/- 0.3, 55.3 +/- 1.2 and 134.1 +/- 1.5 micrograms l-1, respectively. No significant differences in AsB concentrations were observed among the three samples. The mean As concentrations as AsB in the three samples were 17.4 +/- 0.4, 17.7 +/- 0.2 and 17.5 +/- 0.3 micrograms l-1, respectively. By off-line digestion of the urine samples, total As concentrations in the three materials were also obtained. The mean values were 23.4 +/- 0.3, 76.6 +/- 1.6 and 151.3 +/- 1.8 micrograms l-1, respectively. These results correlated well with the results obtained by neutron activation analysis in our laboratory (r = 0.999; p < 0.0001). PMID:10435351

  3. Corrosion investigations on zircaloy-4 and titanium dissolver materials for MOX fuel dissolution in concentrated nitric acid containing fluoride ions

    NASA Astrophysics Data System (ADS)

    Jayaraj, J.; Krishnaveni, P.; Krishna, D. Nanda Gopala; Mallika, C.; Mudali, U. Kamachi

    2016-05-01

    Aqueous reprocessing of plutonium-rich mixed oxide fuels require fluoride as a dissolution catalyst in boiling nitric acid for an effective dissolution of the spent fuel. High corrosion rates were obtained for the candidate dissolver materials zircaloy-4 (Zr-4) and commercial pure titanium (CP-Ti grade 2) in boiling 11.5 M HNO3 + 0.05 M NaF. Complexing the fluoride ions either with Al(NO3)3 or ZrO(NO3)2 aided in decreasing the corrosion rates of Zr-4 and CP-Ti. From the obtained corrosion rates it is concluded that CP-Ti is a better dissolver material than Zr-4 for extended service life in boiling 11.5 M HNO3 + 0.05 M NaF, when complexed with 0.15 M ZrO(NO3)2. XPS analysis confirmed the presence of TiO2 and absence of fluoride on the surface of CP-Ti samples, indicating that effective complexation had occurred in solution leading to passivation of the metal and imparting high corrosion resistance.

  4. Immobilization of Lactobacillus rhamnosus in mesoporous silica-based material: An efficiency continuous cell-recycle fermentation system for lactic acid production.

    PubMed

    Zhao, Zijian; Xie, Xiaona; Wang, Zhi; Tao, Yanchun; Niu, Xuedun; Huang, Xuri; Liu, Li; Li, Zhengqiang

    2016-06-01

    Lactic acid bacteria immobilization methods have been widely used for lactic acid production. Until now, the most common immobilization matrix used is calcium alginate. However, Ca-alginate gel disintegrated during lactic acid fermentation. To overcome this deficiency, we developed an immobilization method in which Lactobacillus rhamnosus cells were successfully encapsulated into an ordered mesoporous silica-based material under mild conditions with a high immobilization efficiency of 78.77% by using elemental analysis. We also optimized the cultivation conditions of the immobilized L. rhamnosus and obtained a high glucose conversion yield of 92.4%. Furthermore, L. rhamnosus encapsulated in mesoporous silica-based material exhibited operational stability during repeated fermentation processes and no decrease in lactic acid production up to 8 repeated batches. PMID:26803707

  5. Hot Melt Extrusion: Development of an Amorphous Solid Dispersion for an Insoluble Drug from Mini-scale to Clinical Scale.

    PubMed

    Agrawal, Anjali M; Dudhedia, Mayur S; Zimny, Ewa

    2016-02-01

    The objective of the study was to develop an amorphous solid dispersion (ASD) for an insoluble compound X by hot melt extrusion (HME) process. The focus was to identify material-sparing approaches to develop bioavailable and stable ASD including scale up of HME process using minimal drug. Mixtures of compound X and polymers with and without surfactants or pH modifiers were evaluated by hot stage microscopy (HSM), polarized light microscopy (PLM), and modulated differential scanning calorimetry (mDSC), which enabled systematic selection of ASD components. Formulation blends of compound X with PVP K12 and PVP VA64 polymers were extruded through a 9-mm twin screw mini-extruder. Physical characterization of extrudates by PLM, XRPD, and mDSC indicated formation of single-phase ASD's. Accelerated stability testing was performed that allowed rapid selection of stable ASD's and suitable packaging configurations. Dissolution testing by a discriminating two-step non-sink dissolution method showed 70-80% drug release from prototype ASD's, which was around twofold higher compared to crystalline tablet formulations. The in vivo pharmacokinetic study in dogs showed that bioavailability from ASD of compound X with PVP VA64 was four times higher compared to crystalline tablet formulations. The HME process was scaled up from lab scale to clinical scale using volumetric scale up approach and scale-independent-specific energy parameter. The present study demonstrated systematic development of ASD dosage form and scale up of HME process to clinical scale using minimal drug (∼500 g), which allowed successful clinical batch manufacture of enabled formulation within 7 months. PMID:26729533

  6. Laboratory Simulated Acid-Sulfate Weathering of Basaltic Materials: Implications for Formation of Sulfates at Meridiani Planum and Gusev Crater, Mars

    NASA Technical Reports Server (NTRS)

    Golden, D. C.; Ming, Douglas W.; Morris, Richard V.; Mertzman, A.

    2006-01-01

    Acid-sulfate weathering of basaltic materials is a candidate formation process for the sulfate-rich outcrops and rocks at the MER rover Opportunity and Spirit landing sites. To determine the style of acid-sulfate weathering on Mars, we weathered basaltic materials (olivine-rich glassy basaltic sand and plagioclase feldspar-rich basaltic tephra) in the laboratory under different oxidative, acid-sulfate conditions and characterized the alteration products. We investigated alteration by (1) sulfuric-acid vapor (acid fog), (2) three-step hydrothermal leaching treatment approximating an open system and (3) single-step hydrothermal batch treatment approximating a "closed system." In acid fog experiments, Al, Fe, and Ca sulfates and amorphous silica formed from plagioclase-rich tephra, and Mg and Ca sulfates and amorphous silica formed from the olivine-rich sands. In three-step leaching experiments, only amorphous Si formed from the plagioclase-rich basaltic tephra, and jarosite, Mg and Ca sulfates and amorphous silica formed from olivine-rich basaltic sand. Amorphous silica formed under single-step experiments for both starting materials. Based upon our experiments, jarosite formation in Meridiani outcrop is potential evidence for an open system acid-sulfate weathering regime. Waters rich in sulfuric acid percolated through basaltic sediment, dissolving basaltic phases (e.g., olivine) and forming jarosite, other sulfates, and iron oxides. Aqueous alteration of outcrops and rocks on the West Spur of the Columbia Hills may have occurred when vapors rich in SO2 from volcanic sources reacted with basaltic materials. Soluble ions from the host rock (e.g., olivine) reacted with S to form Ca-, Mg-, and other sulfates along with iron oxides and oxyhydroxides.

  7. A simple procedure for preparing chitin oligomers through acetone precipitation after hydrolysis in concentrated hydrochloric acid.

    PubMed

    Kazami, Nao; Sakaguchi, Masayoshi; Mizutani, Daisuke; Masuda, Tatsuhiko; Wakita, Satoshi; Oyama, Fumitaka; Kawakita, Masao; Sugahara, Yasusato

    2015-11-01

    Chitin oligomers are of interest because of their numerous biologically relevant properties. To prepare chitin oligomers containing 4-6 GlcNAc units [(GlcNAc)4-6], α- and β-chitin were hydrolyzed with concentrated hydrochloric acid at 40 °C. The reactant was mixed with acetone to recover the acetone-insoluble material, and (GlcNAc)4-6 was efficiently recovered after subsequent water extraction. Composition analysis using gel permeation chromatography and MALDI-TOF mass spectrometry indicated that (GlcNAc)4-6 could be isolated from the acetone-insoluble material with recoveries of approximately 17% and 21% from the starting α-chitin and β-chitin, respectively. The acetone precipitation method is highly useful for recovering chitin oligomers from the acid hydrolysate of chitin. The changes in the molecular size and higher-order structure of chitin during the course of hydrolysis were also analyzed, and a model that explains the process of oligomer accumulation is proposed. PMID:26256353

  8. The use of nanometer tetrabasic lead sulfate as positive active material additive for valve regulated lead-acid battery

    NASA Astrophysics Data System (ADS)

    Lang, Xiaoshi; Wang, Dianlong; Hu, Chiyu; Tang, Shenzhi; Zhu, Junsheng; Guo, Chenfeng

    2014-12-01

    Conventional tetrabasic lead sulfate used as positive active material additive shows the results of the low effective lead dioxide conversion rate due to the large grain size and crossed the crystal structure. In this paper, we study on a type of nanometer tetrabasic lead sulfate. Through the XRD and SEM test and Material Studio software calculation, the purity of tetrabasic lead sulfate is very high, the grain size of the nanometer 4BS is almost unanimous, and can be controlled below 200 nm. When charged and discharged in 1.75 V-2.42 V with the current density of 40 mA g-1, 80 mA g-1 and 160 mA g-1, the effective lead dioxide conversion rate of nanometer 4BS after formation can achieve to 83.48%, 71.42%, and 66.96%. Subsequently, the nanometer 4BS as additive is added to positive paste of lead-acid battery. When the batteries are tested galvanostatically between 1.75 V and 2.42 V at 0.25 C charge and 0.5 C discharge rates at room temperature. The ratio of adding nanometer 4BS is 0%, 1% and 4% and the initial discharge specific capacities are 60 mAh g-1, 65 mAh g-1 and 68 mAh g-1. After 80 cycles, the initial discharge capacity of positive active material with 1% nanometer 4BS decreased less than 10%, while adding 4% nanometer 4BS, the initial discharge capacity doesn't decrease obviously.

  9. Effect of chemical composition on corneal cellular response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid.

    PubMed

    Lai, Jui-Yang

    2013-10-01

    Characterization of corneal cellular response to hydrogel materials is an important issue in ophthalmic applications. In this study, we aimed to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and material compatibility towards corneal stromal and endothelial cells. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Results of electrokinetic measurements showed that an increase in absolute zeta potential of photopolymerized membranes is observed with increasing the volume ratios of AAc/HEMA. Following 4 days of incubation with various hydrogels, the primary rabbit corneal stromal and endothelial cell cultures were examined for viability, proliferation, and pro-inflammatory gene expression. The samples prepared from the solution mixture containing 0-10 vol.% AAc displayed good cytocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the decreased viability, inhibited proliferation, and stimulated inflammation were noted in both cell types, probably due to the stronger charge-charge interactions. On the other hand, the ionic pump function of corneal endothelial cells exposed to photopolymerized membranes was examined by analyzing the Na(+),K(+)-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of material samples having higher anionic charge density (i.e., zeta potential of -38 to -56 mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal stromal and endothelial cell responses to polymeric biomaterials. PMID:23910267

  10. Sorption of estrogens and pesticides from aqueous solution by a humic acid and raw and processed plant materials

    NASA Astrophysics Data System (ADS)

    Loffredo, Elisabetta; Taskin, Eren

    2016-04-01

    The huge number of organic contaminants released in water as a consequence of anthropogenic activities have detrimental effects to environmental systems and human health. Industrial products and byproducts, pharmaceuticals, pesticides, detergents and so on impose increasing costs for wastewater decontamination. Adsorption techniques can be successfully used for the treatment of wastewaters to remove contaminants of various nature. Humic acids (HA) have well-known adsorptive capacities towards hydrophilic and, especially, hydrophobic compounds. In the recent years, alternative low-cost adsorbents, especially originated from agricultural wastes and food industries residues, such as wood chips, almond and coconut shells, peanut and rice husks, are under investigation. Biochar is also considered a promising and relatively low-cost adsorbent, even if there are still knowledge gaps about the influence of feedstock type, pyrolysis conditions, physical and chemical properties on its potential and safe use. In the present work, a HA from a green compost was used along with three other materials of plant origin to remove two estrogens, 4-tert-octylphenol and 17-β-estradiol, and two pesticides, carbaryl and fenuron, from an aqueous solution. The four molecules were spiked in water each at a concentration of 1 mg L-1. The materials were: a biochar obtained from 100% red spruce pellet pyrolysed at 550 °C, spent coffee grounds and spent tea leaves. Kinetics curves and adsorption isotherms studies were performed using a batch equilibrium method. Adsorption data obtained for each compound were fitted to a linear equation and non-linear Freundlich and Langmuir models. Kinetics data of the four compounds onto all adsorbents showed an initial very rapid adsorption which was completed in few hours when it reached equilibrium. The two estrogens were adsorbed onto all materials more quickly than the two less hydrophobic pesticides. Significant differences among adsorbents and the

  11. Solubility of Structurally Complicated Materials: II. Bone

    NASA Astrophysics Data System (ADS)

    Horvath, Ari L.

    2006-12-01

    Bone is a structurally complex material, formed of both organic and inorganic chemicals. The organic compounds constitute mostly collagen and other proteins. The inorganic or bone mineral components constitute predominantly calcium, phosphate, carbonate, and a host of minor ingredients. The mineralized bone is composed of crystals which are closely associated with a protein of which collagen is an acidic polysaccharide material. This association is very close and the protein integrates into the crystalline structure. The mineralization involves the deposition of relatively insoluble crystals on an organic framework. The solubility process takes place when the outermost ions in the crystal lattice breakaway from the surface and become separated from the crystal. This is characteristic for ions dissolving in water or aqueous solutions at the specified temperature. The magnitude of solubility is temperature and pH dependent. Bone is sparingly soluble in most solvents. Enamel is less soluble than bone and fluoroapatite is the least soluble of all apatites in acid buffers. Collagen is less soluble in neutral salt solution than in dilute acid solutions at ambient temperatures. The solubility of collagens in solvents gradually decreases with increasing age of the bone samples.

  12. Dissolution state of cellulose in aqueous systems. 2. Acidic solvents.

    PubMed

    Alves, Luis; Medronho, Bruno; Antunes, Filipe E; Topgaard, Daniel; Lindman, Björn

    2016-10-20

    Cellulose is insoluble in water but can be dissolved in strong acidic or alkaline conditions. How well dissolved cellulose is in solution and how it organizes are key questions often neglected in literature. The typical low pH required for dissolving cellulose in acidic solvents limits the use of typical characterization techniques. In this respect, Polarization Transfer Solid State NMR (PT ssNMR) emerges as a reliable alternative. In this work, combining PT ssNMR, microscopic techniques and X-ray diffraction, a set of different acidic systems (phosphoric acid/water, sulfuric acid/glycerol and zinc chloride/water) is investigated. The studied solvent systems are capable to efficiently dissolve cellulose, although degradation occurs to some extent. PT ssNMR is capable to identify the liquid and solid fractions of cellulose, the degradation products and it is also sensitive to gelation. The materials regenerated from the acidic dopes were found to be highly sensitive to the solvent system and to the presence of amphiphilic additives in solution. PMID:27474617

  13. Research on the interaction of hydrogen-bond acidic polymer sensitive sensor materials with chemical warfare agents simulants by inverse gas chromatography.

    PubMed

    Yang, Liu; Han, Qiang; Cao, Shuya; Huang, Feng; Qin, Molin; Guo, Chenghai; Ding, Mingyu

    2015-01-01

    Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant) and 2-CEES (a blister agent simulant) were used as probes. Chemical and physical parameters such as heats of absorption and Henry constants of the polymers to DMMP and 2-CEES were determined by inverse gas chromatography. Details concerning absorption performance are also discussed in this paper. PMID:26043177

  14. Research on the Interaction of Hydrogen-Bond Acidic Polymer Sensitive Sensor Materials with Chemical Warfare Agents Simulants by Inverse Gas Chromatography

    PubMed Central

    Yang, Liu; Han, Qiang; Cao, Shuya; Huang, Feng; Qin, Molin; Guo, Chenghai; Ding, Mingyu

    2015-01-01

    Hydrogen-bond acidic polymers are important high affinity materials sensitive to organophosphates in the chemical warfare agent sensor detection process. Interactions between the sensor sensitive materials and chemical warfare agent simulants were studied by inverse gas chromatography. Hydrogen bonded acidic polymers, i.e., BSP3, were prepared for micro-packed columns to examine the interaction. DMMP (a nerve gas simulant) and 2-CEES (a blister agent simulant) were used as probes. Chemical and physical parameters such as heats of absorption and Henry constants of the polymers to DMMP and 2-CEES were determined by inverse gas chromatography. Details concerning absorption performance are also discussed in this paper. PMID:26043177

  15. The potential of an insoluble dietary fiber-rich source from barley to protect from DMH-induced intestinal tumors in rats.

    PubMed

    McIntosh, G H; Jorgensen, L; Royle, P

    1993-01-01

    The influence of soluble and insoluble dietary fiber supplements from barley and wheat on colon cancer risk was assessed using male Sprague-Dawley rats from four weeks of age on a semipurified (AIN76A) rat diet modified to contain 20% fat of mixed animal and plant origin and 5% dietary fiber. Gastrointestinal tumors were induced with dimethylhydrazine given weekly for five weeks at 15 mg/kg body wt by subcutaneous injection, commencing four weeks after rats were established on the experimental diets. At 32 weeks of age, rats were killed and tumors assessed. The insoluble dietary fiber-rich source from barley (spent barley grain, SBG) was significantly more effective at preventing induced tumors than soluble fiber-rich commercial barley bran. There were no significant differences among the results for the other three fiber sources, which were intermediate in their influence. Both incidence of rats affected and tumor mass index were reduced, the latter significantly, when SBG was compared with commercial barley bran. SBG also produced a significant reduction in plasma cholesterol concentration (down 17%, p < 0.05) relative to wheat bran, but commercial barley bran was not different from wheat bran at this stage. Pure cellulose and outer-layer barley bran were, by comparison, only moderately effective in cancer prevention. SBG, like wheat bran, is a good source of cellulose and hemicellulose. It is also a good source of proteins, polyphenolics, fatty acids (including alpha-linolenic), vitamin E, and minerals. Further research is needed to clarify the relevance of these other factors to the differences observed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8389043

  16. Comparative Study of Stearic Acid/Iron-Oxide Binary and Stearic Acid/Iron-Oxide/Titanium-Oxide Ternary for Use as Energy Storage Material

    NASA Astrophysics Data System (ADS)

    Andiarto, Rizky; Khalish Nuryadin, Muhammad; Saleh, Rosari

    2016-04-01

    In this work, a series of stearic acid/Fe3O4, and stearic acid/Fe3O4/TiO2 nanocomposites for thermal energy storage (TES) system were synthesized through a two-step process. Fe3O4 nanoparticles and Fe3O4/TiO2 nanocomposites were first prepared using sol-gel methods and then both samples were mixed into stearic acid by dispersion technique at three different weight % ratio to stearic acid: 5%, 10% and 15% to obtain stearic acid/Fe3O4, and stearic acid/Fe3O4/TiO2 nanocomposites. Morphologies and structural properties of the samples were characterized by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM) and energy dispersive X-ray spectroscopy (EDX), while thermal properties of the sample were determined by differential scanning calorimetry (DSC) and fhermogravimetric analysis (TGA). The XRD patterns demonstrate, that stearic acid/Fe3O4 contained characteristic peaks of Fe3O4 and stearic acid structures, while peaks corresponded to anatase TiO2 structures appear in stearic acid/ Fe3O4/TiO2 nanocomposites. From the DSC measurements, it is found that the maximum latent heat was found at samples with weight ratio of 5%. Moreover, the enhancement up to 20% of latent heat in solidifying as well as melting processes was observed. TGA measurements show high degradation temperature in the range of 246 - 251°C. The TGA results also shows that the residual mass of the sample matches the composition of Fe3O4 and Fe3O4/TiO2 which is added to the stearic acid.

  17. Ampholine-functionalized hybrid organic-inorganic silica material as sorbent for solid-phase extraction of acidic and basic compounds.

    PubMed

    Wang, Tingting; Chen, Yihui; Ma, Junfeng; Chen, Mingliang; Nie, Chenggang; Hu, Minjie; Li, Ying; Jia, Zhijian; Fang, Jianghua; Gao, Haoqi

    2013-09-20

    A novel sorbent for solid-phase extraction (SPE) was synthesized by chemical immobilization of ampholine on hybrid organic-inorganic silica material. The ampholine-functionalized hybrid organic-inorganic silica sorbent is consisted of aliphatic amine groups, carboxyl groups and long carbon chains, allowing for extraction of both acidic and basic compounds. The retention properties of the developed sorbent were evaluated for 1-hydroxy-2-naphthoic acid (HNA), 1-naphthoic acid (NA), 3-hydroxybenzoic acid (HBA), benzoic acid (BA), sorbic acid (SA), vanillic aldehyde (VA), butyl 4-hydroxybenzoate (BHB), propyl 4-hydroxybenzoate (PHB), ethyl 4-hydroxybenzoate (EHB), and methyl 4-hydroxybenzoate (MHB). The results show that such a sorbent has three types of interaction, i.e., electrostatic interaction, hydrophobic interaction, and hydrogen bonding, exhibiting high extraction efficiency towards the compounds tested. The adsorption capacities of the analytes ranged from 0.61 to 6.54μgmg(-1). The reproducibility of the sorbent preparation was evaluated at three spiking concentration levels, with relative standard deviations (RSDs) of 1.0-10.5%. The recoveries of ten acidic and basic compounds spiked in beverage Coca-Cola(®) sample ranged from 82.5% to 98.2% with RSDs less than 5.8%. Under optimum conditions, the ampholine-functionalized hybrid organic-inorganic silica sorbent rendered higher extraction efficiency for acidic compounds than that of the commercially available ampholine-functionalized silica particles, and was comparable to that of the commercial Oasis WAX and Oasis WCX. PMID:23953713

  18. Activation of rat complement by soluble and insoluble rat IgA immune complexes.

    PubMed

    Rits, M; Hiemstra, P S; Bazin, H; Van Es, L A; Vaerman, J P; Daha, M R

    1988-12-01

    The ability of rat monoclonal IgA, specific for 2,4-dinitrophenyl (DNA), to activate the complement (C) system of the rat was investigated using aggregated IgA or IgA immune complexes (IC). IgA was coated onto a solid phase, and tested for its capacity to bind C3 upon incubation at 37 degrees C in normal rat serum (NRS) in the presence of Mg-EGTA. Binding of C3 was observed dependent on the dose of dimeric (d-), polymeric (p-) and secretory IgA tested. In contrast, little C3 fixation was observed in this system with monomeric (m-) rat IgA or with mouse m- and d-IgA (MOPC315). Soluble and insoluble rat IgA IC were prepared using dinitrophenylated rat serum albumin (DNP8RSA) as antigen (Ag), and assessed for C activation. It was shown that insoluble IC (immune precipitates; IP) containing m-, d- or pIgA of rat origin activate the alternative pathway of rat C, as demonstrated by their capacity to induce C consumption in NRS in the presence of Mg-EGTA. When p- and m-IgA IP were compared for their capacity to activate C, it was found that p-IgA activated C four times as efficiently as m-IgA IP (at 2 mg/ml). Soluble rat IgA IC were prepared in an excess of DNP8RSA, fractionated by gel filtration on Sepharose 6B, and analyzed for C activation and antibody (Ab)/Ag ratio. In contrast to m-IgA IP, soluble m-IgA did not activate C. On the other hand soluble d-IgA IC activated C dependent on their concentration and size: at a concentration of 0.1 mg/ml high-molecular weight d-IgA IC with a high Ab/Ag ratio were four times as efficient as low-molecular weight IC with a low Ab/Ag ratio, and twice as efficient as IP prepared at equivalence. To demonstrate the induction by IgA of the assembly of the terminal membrane attack complex, trinitrophenyl (TNP)-conjugated rat red blood cells (TNP-RRBC) coated with d- or p-IgA were shown to be lysed in NRS in the presence of Mg-EGTA. No lysis of m-IgA-coated TNP-RRBC was observed. The results in this study demonstrate that both soluble and

  19. Effects of simple acid leaching of crushed and powdered geological materials on high-precision Pb isotope analyses

    NASA Astrophysics Data System (ADS)

    Todd, Erin; Stracke, Andreas; Scherer, Erik E.

    2015-07-01

    We present new results of simple acid leaching experiments on the Pb isotope composition of USGS standard reference material powders and on ocean island basalt whole rock splits and powders. Rock samples were leached with cold 6 N HCl in an ultrasonic bath, then on a hot plate, and washed with ultrapure H2O before sample digestion in HF-HNO3 and chromatographic purification of Pb. Lead isotope analyses were measured by Tl-doped MC-ICPMS. Intrasession and intersession analytical reproducibilities of repeated analyses of both synthetic Pb solutions and Pb from single digests of chemically processed natural samples were generally better than 100 ppm (2 SD). The comparison of leached and unleached samples shows that leaching consistently removes variable amounts of contaminants that differ in Pb isotopic composition for different starting materials. For repeated digests of a single sample, analyses of leached samples reproduce better than those of unleached ones, confirming that leaching effectively removes most of the heterogeneously distributed extraneous Pb. Nevertheless, the external reproducibility of leached samples is still up to an order of magnitude worse than that of Pb solution standards (˜100 ppm). More complex leaching methods employed by earlier studies yield Pb isotope ratios within error of those produced by our method and at similar levels of reproducibility, demonstrating that our simple leaching method is as effective as more complex leaching techniques. Therefore, any Pb isotope heterogeneity among multiple leached digests of samples in excess of the external reproducibility is attributed to inherent isotopic heterogeneity of the sample. The external precision of ˜100 ppm (2 SD) achieved for Pb isotope ratio determination by Tl-doped MC-ICPMS is thus sufficient for most rocks. The full advantage of the most precise Pb isotope analytical methods is only realized in cases where the natural isotopic heterogeneity among samples in a studied suite is

  20. Effect of chemical composition on corneal tissue response to photopolymerized materials comprising 2-hydroxyethyl methacrylate and acrylic acid.

    PubMed

    Lai, Jui-Yang

    2014-01-01

    The purpose of this work was to investigate the relationship between the feed composition of 2-hydroxyethyl methacrylate (HEMA)/acrylic acid (AAc) and hydrogel material compatibility towards ocular anterior segment tissues, particularly the corneal endothelium. The monomer solutions of HEMA and AAc were mixed at varying volume ratios of 92:0, 87:5, 82:10, 77:15, and 72:20, and were subjected to UV irradiation. Then, the 7-mm-diameter membrane implants made from photopolymerized materials were placed into the ocular anterior chamber for 4days and assessed by biomicroscopic examinations, corneal thickness measurements, and quantitative real-time reverse transcription polymerase chain reaction analyses. The poly(HEMA-co-AAc) implants prepared from the solution mixture containing 0-10vol.% AAc displayed good biocompatibility. However, with increasing volume ratio of AAc and HEMA from 15:77 to 20:72, the enhanced inflammatory response, decreased endothelial cell density, and increased ocular score and corneal thickness were observed, probably due to the influence of surface charge of copolymer membranes. On the other hand, the ionic pump function of corneal endothelium exposed to photopolymerized membranes was examined by analyzing the Na(+),K(+)-ATPase alpha 1 subunit (ATP1A1) expression level. The presence of the implants having higher amount of AAc incorporated in the copolymers (i.e., 15.1 to 24.7μmol) and zeta potential (i.e., -38.6 to -56.5mV) may lead to abnormal transmembrane transport. It is concluded that the chemical composition of HEMA/AAc has an important influence on the corneal tissue responses to polymeric biomaterials. PMID:24268266

  1. Materials

    NASA Technical Reports Server (NTRS)

    Glaessgen, Edward H.; Schoeppner, Gregory A.

    2006-01-01

    NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.

  2. Re-examining the applications of amylase in the sugar industry: Conquering the control of insoluble and soluble starch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The new knowledge that there is markedly more insoluble starch than previously considered in products across both the sugarcane factory and refinery has processing implications. Processing parameters such as viscosity and filtration are implicated, as well as the application of '-amylases in the fa...

  3. A novel strategy to produce highly stable and transparent aqueous 'nanosolutions' of water-insoluble drug molecules

    NASA Astrophysics Data System (ADS)

    Wang, Jie-Xin; Zhang, Zhi-Bing; Le, Yuan; Zhao, Hong; Chen, Jian-Feng

    2011-07-01

    A surprisingly large proportion of new drug candidates emerging from drug discovery programmes are water-insoluble and, as a result, have poor oral bioavailability. To overcome insolubility, the drug particles are usually dispersed in a medium during product formation, but large particles that are formed may affect product performance and safety. Many techniques have been used to produce nanodispersions—dispersions with nanometre-scale dimensions—that have properties similar to solutions. However, making nanodispersions requires complex processing, and it is difficult to achieve stability over long periods. In this paper, we report a generic method for preparing drug nanoparticles with a combination of antisolvent precipitation in the presence of water-soluble matrices and spray-drying. The spray-dried powder composites (solid dispersion) are microspherical, highly stable and thus form transparent nanodispersions or so-called 'nanosolutions' of water-insoluble drug when simply added to water. Aqueous nanodispersions of silybin (a kind of water-insoluble drug for liver protection) with an average size of 25 nm produced with this approach display a 10 times faster dissolution rate than that of raw drug. This has great potential to offer a novel solution for innovative drugs of the future.

  4. Development of an analytical method to measure insoluble and soluble starch in sugarcane and sweet sorghum products

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A rapid, quantitative research method using microwave-assisted probe ultrasonication was developed to facilitate the determination of total insoluble, and soluble starch in various sugar crop products. Several variables that affect starch solubilization were evaluated, 1) conductive boiling time, 2...

  5. Hollow silica nanospheres coated with insoluble calcium salts for pH-responsive sustained release of anticancer drugs.

    PubMed

    Guo, Yuming; Fang, Qilong; Li, Han; Shi, Weike; Zhang, Jie; Feng, Jing; Jia, Weili; Yang, Lin

    2016-08-23

    Hollow silica nanospheres coated with biocompatible and pH-sensitive inorganic insoluble calcium salts including calcium carbonate and hydroxyapatite have been successfully prepared. The results indicate that the nanospheres can efficiently load doxorubicin and release it in a pH-responsive and sustained manner, and improve the treatment efficacy significantly. PMID:27501741

  6. COMBINED USE OF A WATER-INSOLUBLE CHEMICAL DELIVERY SYSTEM AND A METABOLIC ACTIVATION SYSTEM IN WHOLE EMBRYO CULTURE

    EPA Science Inventory

    An integrated water insoluble chemical delivery/metabolic activation/rat embryo culture system is described. In initial studies corn oil was used as the solvent and diallate as the substrate. Increasing concentrations of diallate dissolved in corn oil caused embryonic growth reta...

  7. Effects of insoluble surfactants on the nonlinear deformation and breakup of stretching liquid bridges

    NASA Astrophysics Data System (ADS)

    Ambravaneswaran, Bala; Basaran, Osman A.

    1999-05-01

    During the emission of single drops and the atomization of a liquid from a nozzle, threads of liquid are stretched and broken. A convenient setup for studying in a controlled manner the dynamics of liquid threads is the so-called liquid bridge, which is created by holding captive a volume of liquid between two solid disks and pulling apart the two disks at a constant velocity. Although the stability of static bridges and the dynamics of stretching bridges of pure liquids have been extensively studied, even a rudimentary understanding of the dynamics of the stretching and breakup of bridges of surfactant-laden liquids is lacking. In this work, the dynamics of a bridge of a Newtonian liquid containing an insoluble surfactant are analyzed by solving numerically a one-dimensional set of equations that results from a slender-jet approximation of the Navier-Stokes system that governs fluid flow and the convection-diffusion equation that governs surfactant transport. The computational technique is based on the method-of-lines, and uses finite elements for discretization in space and finite differences for discretization in time. The computational results reveal that the presence of an insoluble surfactant can drastically alter the physics of bridge deformation and breakup compared to the situation in which the bridge is surfactant free. They also make clear how the distribution of surfactant along the free surface varies with stretching velocity, bridge geometry, and bulk and surface properties of the liquid bridge. Gradients in surfactant concentration along the interface give rise to Marangoni stresses which can either retard or accelerate the breakup of the liquid bridge. For example, a high-viscosity bridge being stretched at a low velocity is stabilized by the presence of a surfactant of low surface diffusivity (high Peclet number) because of the favorable influence of Marangoni stresses on delaying the rupture of the bridge. This effect, however, can be lessened or

  8. Studies of the development of brain barrier systems to lipid insoluble molecules in fetal sheep.

    PubMed Central

    Dziegielewska, K M; Evans, C A; Malinowska, D H; Møllgård, K; Reynolds, J M; Reynolds, M L; Saunders, N R

    1979-01-01

    1. The development of the blood-brain and blood-c.s.f barriers to lipid insoluble substances of different molecular radii has been studied in fetal sheep, early (60 days) and late (125 days) in gestation, using labelled erythritol (C14), sucrose (3H or 14C), inulin (3H or 14C) and albumin (125I), or albumin and IgG detected by immunoassay. 2. Morphological studies of fetal brain and choroid plexus at the same gestational stages were carried out using thin section electron microscopy and the freeze fracture techniques. 3. Penetration of markers into c.s.f. was substantially greater at 60 days than at 125 days, but at both ages the steady-state level achieved appeared to be related to molecular size. 4. A simple model describing penetration from blood into c.s.f. at 60 days is proposed. It involves the assumption that c.s.f. and brain extracellular fluid are effectively separate compartments; morphological and permeability data which supports this assumption is presented. The data for c.s.f. at 60 days are consistent with the suggestion that the markers penetrate into c.s.f. by diffusion and are not restricted by small pores in the interface between blood and c.s.f. 5. The reduction in penetration which occurred by 125 days for all markers except erythritol appears to be accounted for by an increase in the sink effect and a decrease in the effective surface area for exchange between blood and c.s.f. 6. Intercellular tight junctions of both cerebral endothelial cells and choroid plexus epithelial cells were well formed at 60 days gestation. There was no change in junctional characteristics previously thought to correlate with transepithelial permeability (tight junction depth and strand number) between the two ages studied, although there were marked changes in permeability. 7. Evidence is advanced in support of the hypothesis that in the fetus much of the penetration of lipid insoluble non-polar substances across the blood-c.s.f. barrier and perhaps across the blood

  9. Novel lead-graphene and lead-graphite metallic composite materials for possible applications as positive electrode grid in lead-acid battery

    NASA Astrophysics Data System (ADS)

    Yolshina, L. A.; Yolshina, V. A.; Yolshin, A. N.; Plaksin, S. V.

    2015-03-01

    Novel lead-graphene and lead-graphite metallic composites which melt at temperature of the melting point of lead were investigated as possible positive current collectors for lead acid batteries in sulfuric acid solution. Scanning electron microscopy, Raman spectroscopy, difference scanning calorimetry, cyclic voltammetry and prolonged corrosion tests were employed to characterize the effect of the newly proposed lead-carbon metallic composites on the structure and electrochemical properties of positive grid material. Both lead-graphene and lead-graphite metallic composite materials show the similar electrochemical characteristics to metallic lead in the voltage range where the positive electrodes of lead acid batteries operate. It has been shown that carbon both as graphene and graphite does not participate in the electrochemical process but improve corrosion and electrochemical characteristics of both metallic composite materials. No products of interaction of lead with sulfuric acid were formed on the surface of graphene and graphite so as it was not found additional peaks of carbon discharge on voltammograms which could be attributed to the carbon. Graphene inclusions in lead prevent formation of leady oxide nanocrystals which deteriorate discharge characteristics of positive electrode of LAB. Both lead-graphene alloy and lead-graphite metallic composite proved excellent electrochemical and corrosion behavior and can be used as positive grids in lead acid batteries of new generation.

  10. A Reexamination of Amino Acids in Lunar Soils: Implications for the Survival of Exogenous Organic Material During Impact Delivery

    NASA Technical Reports Server (NTRS)

    Brinton, Karen L. F.; Bada, Jeffrey L.

    1996-01-01

    Using a sensitive high performance liquid chromatography technique, we have analyzed both the hot water extract and the acid hydrolyzed hot water extract of lunar soil collected during the Apollo 17 mission. Both free amino acids and those derived from acid labile precursors are present at a level of roughly 15 ppb. Based on the D/L amino acid ratios, the free alanine and aspartic acid observed in the hot water extract can be entirely attributed to terrestrial biogenic contamination. However, in the acid labile fraction, precursors which yield amino acids are apparently present in the lunar soil. The amino acid distribution suggests that the precursor is probably solar wind implanted HCN. We have evaluated our results with regard to the meteoritic input of intact organic compounds to the moon based on an upper limit of less than or equal to 0.3 ppb for alpha-aminoisobutyric acid, a non-protein amino acid which does not generally occur in terrestrial organisms and which is not a major amino acid produced from HCN, but which is a predominant amino acid in many carbonaceous chondrites. We find that the survival of exogenous organic compounds during lunar impact is less than or equal to 0.8%. This result represents an example of minimum organic impact survivability. This is an important first step toward a better understanding of similar processes on Earth and on Mars, and their possible contribution to the budget of prebiotic organic compounds on the primitive Earth.

  11. A reexamination of amino acids in lunar soils: implications for the survival of exogenous organic material during impact delivery.

    PubMed

    Brinton, K L; Bada, J L

    1996-01-01

    Using a sensitive high performance liquid chromatography technique, we have analyzed both the hot water extract and the acid hydrolyzed hot water extract of lunar soil collected during the Apollo 17 mission. Both free amino acids and those derived from acid labile precursors are present at a level of roughly 15 ppb. Based on the D/L amino acid ratios, the free alanine and aspartic acid observed in the hot water extract can be entirely attributed to terrestrial biogenic contamination. However, in the acid labile fraction, precursors which yield amino acids are apparently present in the lunar soil. The amino acid distribution suggests that the precursor is probably solar wind implanted HCN. We have evaluated our results with regard to the meteoritic input of intact organic compounds to the moon based on an upper limit of < or = 0.3 ppb for alpha-aminoisobutyric acid, a non-protein amino acid which does not generally occur in terrestrial organisms and which is not a major amino acid produced from HCN, but which is a predominant amino acid in many carbonaceous chondrites. We find that the survival of exogenous organic compounds during lunar impact is < or = 0.8%. This result represents an example of minimum organic impact survivability. This is an important first step toward a better understanding of similar processes on Earth and on Mars, and their possible contribution to the budget of prebiotic organic compounds on the primitive Earth. PMID:11541128

  12. Hazardous waste to materials: recovery of molybdenum and vanadium from acidic leach liquor of spent hydroprocessing catalyst using alamine 308.

    PubMed

    Sahu, K K; Agrawal, Archana; Mishra, D

    2013-08-15

    Recovery of valuable materials/metals from waste goes hand in hand with environmental protection. This paper deals with the development of a process for the recovery of metals such as Mo, V, Ni, Al from spent hydroprocessing catalyst which may otherwise cause a nuisance if dumped untreated. A detailed study on the separation of molybdenum and vanadium from the leach solution of spent hydroprocessing catalyst of composition: 27.15% MoO₃, 1.7% V₂O₅, 3.75% NiO, 54.3% Al₂O₃, 2.3% SiO₂ and 10.4% LOI is reported in this paper. The catalyst was subjected to roasting under oxidizing atmosphere at a temperature of about 550 °C and leaching in dilute sulphuric acid to dissolve molybdenum, vanadium, nickel and part of aluminium. Metals from the leach solution were separated by solvent extraction. Both molybdenum and vanadium were selectively extracted with a suitable organic solvent leaving nickel and dissolved aluminium in the raffinate. Various parameters such as initial pH of the aqueous feed, organic to aqueous ratio (O:A), solvent concentration etc. were optimized for the complete extraction and recovery of Mo and V. Molybdenum and vanadium from the loaded organic were stripped by ammonia solution. They were recovered as their corresponding ammonium salt by selective precipitation, and were further calcined to get the corresponding oxides in pure form. PMID:23644591

  13. [Hygienic characterization of lactic acid bacteria products prepared by using hydrolysates of raw milk and soya bean materials].

    PubMed

    Tsinberg, M B; Deriabin, D G; Denisova, I V

    2002-01-01

    The paper reflects the results of a comparative study of preparations of lactic acid bacteria (LAB), which are based on the hydrolysates of raw milk and soya bean materials, by using methods to determine the organoleptic and physicochemical properties, microbiological characteristics including the titer of microbial cells per ml of the preparation and the presence/absence of representatives of sanitary significant groups of microorganisms, the persistent properties of microorganisms. By summarizing the findings, it can be stated that it is possible to use a raw soya-bean hydrolysate-based nutrient medium to cultivate technical LAB strains with the compliance of the toxicological and microbiological parameters of the prepared preparations with the current sanitary standards. The LAB preparations grown on the hydrolysate-soya-bean medium have been protected with the patents of Russia. Their biological properties are highly competitive with those and, in some cases, superior to hydrolysate-milk medium-based preparations. This presents in their adhesive potential and in the formation of more pronounced antagonistic properties against opportunistic microorganisms. PMID:12476838

  14. Electrochemical oxidation of humic acid and sanitary landfill leachate: Influence of anode material, chloride concentration and current density.

    PubMed

    Fernandes, A; Santos, D; Pacheco, M J; Ciríaco, L; Lopes, A

    2016-01-15

    The influence of applied current density and chloride ion concentration on the ability of Ti/Pt/PbO2 and Ti/Pt/SnO2-Sb2O4 anodes for the electrochemical oxidation of humic acid and sanitary landfill leachate samples was assessed and compared with that of BDD anode. For the experimental conditions used, results show that both organic load and nitrogen removal rates increase with the applied current density and chloride ion concentration, although there is an optimum COD/[Cl-]0 ratio below which there is no further increase in COD removal. Metal oxide anodes present a similar performance to that of BDD, being the results obtained for Ti/Pt/PbO2 slightly better than for Ti/Pt/SnO2-Sb2O4. Contrary to BDD, Ti/Pt/PbO2 promotes lower nitrate formation and is the most suitable material for total nitrogen elimination. The importance of the optimum ratio of Cl-/COD/NH4 +initial concentrations is discussed. PMID:26410703

  15. Optimization of material and energy consumption for removal of Acid Red 14 by simultaneous electrocoagulation and electroflotation.

    PubMed

    Hooshmandfar, Amin; Ayati, Bita; Khodadadi Darban, Ahmad

    2016-01-01

    Decolorization of wastewater of industries which consume dye is an environmental priority. Electrocoagulation and electroflotation methods are appropriate for treatment of these wastewaters. This study investigates the effect of four parameters, electrical conductivity, current density, initial dye concentration, and initial pH, on the performance of a simultaneous electrocoagulation/electroflotation system for removal of Acid Red 14. The optimum values of these parameters were determined based on the amount of electrical energy and aluminum consumption and the best performance of coagulation and bubble generation. The optimum condition was revealed to be electrical conductivity=1,600 μS/cm, current density=60 mA/cm2, initial dye concentration=185 mg/L and initial pH=7. After less than 180 min of electrolysis, 90% dye removal was achieved with a specific energy consumption=102 kWh/kg dyeremoved, anode dissolution=2.09 kg Al/kg dyeremoved and sludge total suspended solids=15,050 mg/L. Liquid chromatography-UV-mass spectroscopy analyses were conducted on samples of raw and treated wastewater. Results showed that intermediate compounds formed from the breaking of the dye molecules. The advantages of this method are a low material and energy consumption. The amount of produced sludge was low; consequently sludge disposal and management costs would be reduced. This method should be used cautiously for treatment of textile wastewater due to the formation of intermediate compounds. PMID:26744951

  16. Removing peanut allergens by tannic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tannic acid (TA) is known to bind and form insoluble complexes with proteins, including peanut allergens; however, whether such complexes would dissociate and release the allergens at pH 2 and 8 (i.e., gastric and intestinal pH) is not clear. Release of the allergens in the gut could lead to absorpt...

  17. Current topics in the biotechnological production of essential amino acids, functional amino acids, and dipeptides.

    PubMed

    Mitsuhashi, Satoshi

    2014-04-01

    Amino acids play important roles in both human and animal nutrition and in the maintenance of health. Here, amino acids are classified into three groups: first, essential amino acids, which are essential to nutrition; second, functional amino acids, recently found to be important in the promotion of physiological functions; and third, dipeptides, which are used to resolve problematic features of specific free amino acids, such as their instability or insolubility. This review focusses on recent researches concerning the microbial production of essential amino acids (lysine and methionine), functional amino acids (histidine and ornithine), and a dipeptide (L-alanyl-L-glutamine). PMID:24679256

  18. Acid-free and oxone oxidant-assisted solvothermal synthesis of graphene quantum dots using various natural carbon materials as resources.

    PubMed

    Shin, Yonghun; Park, Jintaek; Hyun, Daesun; Yang, Junghee; Lee, Jae-Hyeok; Kim, Jae-Ho; Lee, Hyoyoung

    2015-03-19

    To prepare carbon-based fluorescent materials such as graphene quantum dots (GQDs), new and effective methods are needed to convert one-dimensional (1D) or two-dimensional (2D) carbon materials to 0D GQDs. Here, we report a novel acid-free and oxone oxidant-assisted solvothermal synthesis of GQDs using various natural carbon resources including graphite (G), multiwall carbon nanotubes (M), carbon fibers (CF), and charcoal (C). This acid-free method, not requiring the neutralization process of strong acids, exhibits a simple and eco-friendly purification process and also represents a recycling production process, together with mass production and high yield. Newly synthesized GQDs exhibited a strong blue photoluminescence (PL) under 365 nm UV light illumination. The PL emission peaks of all the recycled GQDs did not change. PMID:25757839

  19. Depositional and tectonic interpretation of limestone insoluble residues from modern and ancient carbonate rocks, Caribbean and southeastern United States

    SciTech Connect

    Isphording, W.C.; Bundy, M.E.; George, S.M.

    1995-10-01

    Mineral compositions have long been used as indicators of the provenance and tectonic setting of source rocks for sandstones and shales. Extraction of the same information from limestones is less common because of the general paucity of the non-carbonate phase and the greater processing time that is required to concentrate the frequently encountered small quantities of detrital (and authigenic) minerals. The insoluble component, however, contains a great deal of valuable information and should not be ignored. The clays and other insoluble minerals in limestones from southeastern United States and the Caribbean region, for example, clearly reflect the volcanic activity that was associated with formation of the Mid-Atlantic Ridge rift system and the opening of the Atlantic Ocean and Gulf of Mexico. Similarly, major periods of orogeny during the Paleozoic and Mesozoic have left their signature, even in carbonate rocks that originated far from the sites where uplift was taking place. In other cases, the insoluble residue component clearly manifests periods of quiescence in adjacent land areas or testifies to the airborne transport of insoluble components from sources as far distant as the Saharan Desert of Africa. Similarly, insoluble components have convincingly shown that the origin of the extensive bauxite deposits found in Jamaican limestones are the result of alteration of interbedded volcanic ash units and have not resulted from accumulation of the detritus in the limestones. Residue analysis in Gulf Coast limestones can be successfully used for subsurface identification and correlation of carbonate units in the exploration for hydrocarbons, to reconstruct sedimentary environments, to identify missing sections, and to identify paraconformable realtionships between adjacent carbonate units that are otherwise similar in appearance. The latter is especially useful where extensive recrystallization has taken place and fossils have been destroyed.

  20. Acid-free and oxone oxidant-assisted solvothermal synthesis of graphene quantum dots using various natural carbon materials as resources

    NASA Astrophysics Data System (ADS)

    Shin, Yonghun; Park, Jintaek; Hyun, Daesun; Yang, Junghee; Lee, Jae-Hyeok; Kim, Jae-Ho; Lee, Hyoyoung

    2015-03-01

    To prepare carbon-based fluorescent materials such as graphene quantum dots (GQDs), new and effective methods are needed to convert one-dimensional (1D) or two-dimensional (2D) carbon materials to 0D GQDs. Here, we report a novel acid-free and oxone oxidant-assisted solvothermal synthesis of GQDs using various natural carbon resources including graphite (G), multiwall carbon nanotubes (M), carbon fibers (CF), and charcoal (C). This acid-free method, not requiring the neutralization process of strong acids, exhibits a simple and eco-friendly purification process and also represents a recycling production process, together with mass production and high yield. Newly synthesized GQDs exhibited a strong blue photoluminescence (PL) under 365 nm UV light illumination. The PL emission peaks of all the recycled GQDs did not change.To prepare carbon-based fluorescent materials such as graphene quantum dots (GQDs), new and effective methods are needed to convert one-dimensional (1D) or two-dimensional (2D) carbon materials to 0D GQDs. Here, we report a novel acid-free and oxone oxidant-assisted solvothermal synthesis of GQDs using various natural carbon resources including graphite (G), multiwall carbon nanotubes (M), carbon fibers (CF), and charcoal (C). This acid-free method, not requiring the neutralization process of strong acids, exhibits a simple and eco-friendly purification process and also represents a recycling production process, together with mass production and high yield. Newly synthesized GQDs exhibited a strong blue photoluminescence (PL) under 365 nm UV light illumination. The PL emission peaks of all the recycled GQDs did not change. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr00814j

  1. Scaling vs simulations in the head-on collision of viscous drops with insoluble surfactants

    NASA Astrophysics Data System (ADS)

    Vannozzi, Carolina

    2015-11-01

    Scaling arguments are presented to show the effect of the surface diffusivity Ds on the head-on collision of two equal-sized viscous drops in a viscous matrix with insoluble surfactants. The scaling arguments are compared to simulations of the experimental system studied by Yoon et al. where the drops are Polybutadiene(PBD) in PDMS, stabilized by block copolymers surfactants. Overall, the scaling could predict the effect of the different parameters on the drainage time (the surface Peclet number, the Marangoni number and the pushing force due to the external flow), but could not predict the experimental or simulated values. We tested our simulations against the scaling argument of, that claimed that emulsions stabilized by small molecule surfactants can be described with the assumption of non-diffusing surfactants. Here, however, following the same arguments, but without using the Stokes-Einstein expression for the surfactant surface mobility employed in Ref. and by simply substituting the parameters for different emulsion systems, we show that Ds can be neglected only for oil in water emulsions, not for water in oil emulsion.

  2. Structure of insoluble immune complexes as studied by spectroturbidimetry and dynamic light scattering

    NASA Astrophysics Data System (ADS)

    Khlebtsov, Boris N.; Burygin, Gennadii L.; Matora, Larisa Y.; Shchyogolev, Sergei Y.; Khlebtsov, Nikolai G.

    2004-07-01

    We describe two variants of a method for determining the average composition of insoluble immune complex particles (IICP). The first variant is based on measuring the specific turbidity (the turbidity per unit mass concentration of the dispersed substance) and the average size of IICP determined from dynamic light scattering (DLS). In the second variant, the wavelength exponent (i.e., the slope of the logarithmic turbidity spectrum) is used in combination with specific turbidity measurements. Both variants allow the average biopolymer volume fraction to be determined in terms of the average refractive index of IICP. The method is exemplified by two experimental antigen+antibody systems: (i) lipopolysaccharide-protein complex (LPPC) of Azospirillum brasilense Sp245+rabbit anti-LPPC; and (ii) human IgG (hIgG)+sheep anti-hIgG. Our measurements by the two methods for both types of systems gave, on the average, the same result: the volume fraction of the IICP biopolymers is about 30%; accordingly, the volume fraction of buffer solvent is 70%.

  3. The Co-chaperone BAG2 Sweeps PHF Insoluble Tau from the Microtubule

    PubMed Central

    Carrettiero, Daniel C.; Hernandez, Israel; Neveu, Pierre; Papagiannakopoulos, Thales; Kosik, Kenneth S.

    2009-01-01

    Tau inclusions are a prominent feature of many neurodegenerative diseases including Alzheimer’s disease. Their accumulation in neurons as ubiquitinated filaments suggests a failure in the degradation limb of the Tau pathway. The components of a Tau protein triage system consisting of CHIP/Hsp70 and other chaperones have begun to emerge. However, the site of triage and the master regulatory elements are unknown. Here we report an elegant mechanism of Tau degradation involving the co-chaperone BAG2. The BAG2/Hsp70 complex is tethered to the microtubule and this complex can capture and deliver Tau to the proteasome for ubiquitin-independent degradation. This complex preferentially degrades sarkosyl insoluble Tau and phosphorylated Tau. BAG2 levels in cells are under the physiological control of the microRNA miR-128a, which can tune PHF Tau levels in neurons. Thus we propose that ubiquitinated Tau inclusions arise due to shunting of Tau degradation toward a less efficient ubiquitin-dependent pathway. PMID:19228967

  4. An insight into the biophysical characterization of insoluble collagen aggregates: implication for arthritis.

    PubMed

    Amani, Samreen; Shamsi, Anas; Rabbani, Gulam; Naim, Aabgeena

    2014-09-01

    Misfolding and aggregation of proteins is involved in some of the most prevalent neurodegenerative disorders. The importance of collagen stems from the fact that it is one of the dominant component used for tissue engineering and drug delivery applications and is a major component of skin, tendon, bone and other connective tissues. A systematic investigation on the conformation of collagen at various concentrations of glyoxal is studied by various biophysical techniques such as Trp fluorescence, ANS binding, Circular dichroism (CD), ATR-FTIR, Congo red (CR) assay, Rayleigh light scattering and Turbidity measurements. At 60% (v/v) glyoxal, collagen retains native-like secondary structure, altered Trp environment and high ANS fluorescence, characteristic of molten globule (MG) state. At 80% (v/v) glyoxal, insoluble collagen aggregates are detected as confirmed by decrease in Trp and ANS fluorescence, increase in non-native β sheet structure as evident from far-UV CD and FTIR spectra, increase in Thioflavin T fluorescence, Rayleigh light scattering, Turbidity measurements, as well as red shift in CR absorbance. PMID:25011697

  5. An automatic collector to monitor insoluble atmospheric deposition: an application for mineral dust deposition

    NASA Astrophysics Data System (ADS)

    Laurent, B.; Losno, R.; Chevaillier, S.; Vincent, J.; Roullet, P.; Bon Nguyen, E.; Ouboulmane, N.; Triquet, S.; Fornier, M.; Raimbault, P.; Bergametti, G.

    2015-03-01

    Deposition is one of the key processes controlling the mass budget of the atmospheric mineral dust concentration. However, dust deposition remains poorly constrained in transport models simulating the atmospheric dust cycle. This is mainly due to the limited number of relevant deposition measurements. This paper aims at presenting an automatic collector (CARAGA), specially developed to sample the total (dry and wet) atmospheric deposition of insoluble dust in remote areas. The autonomy of the CARAGA can range from 25 days to almost 1 year depending on the programed sampling time step (1 day and 2 weeks sampling time steps, respectively). This collector is used to sample atmospheric deposition on Frioul Island which is located in the Gulf of Lions in the Western Mediterranean Basin over which Saharan dust can be transported and deposited. To quantify the mineral dust mass in deposition samples, a weighing and ignition protocol is applied. Two years of continuous deposition measurements performed on a weekly time step sampling on Frioul Island are presented and discussed with in-situ measurements, air mass trajectories and satellite observations of dust.

  6. Origin of insoluble organic matter in type 1 and 2 chondrites: New clues, new questions

    NASA Astrophysics Data System (ADS)

    Quirico, Eric; Orthous-Daunay, François-Régis; Beck, Pierre; Bonal, Lydie; Brunetto, Rosario; Dartois, Emmanuel; Pino, Thomas; Montagnac, Gilles; Rouzaud, Jean-Noël; Engrand, Cécile; Duprat, Jean

    2014-07-01

    Insoluble organic matter (IOM) extracted from primitive chondrites is a polyaromatic solid with a structure and composition resembling that of terrestrial kerogens. A survey of its composition and structure has been carried out on a series of 27 CR, CM, CI and ungrouped C2 carbonaceous chondrites (Tagish Lake, Bells, Essebi, Acfer 094) using infrared and multi-wavelength Raman micro-spectroscopy (244, 514 and 785 nm laser excitations). The results show that chondritic IOM from PCA 91008 (CM2), WIS 91600 (CM2), QUE 93005 (CM2), Tagish Lake (C2 ungrouped) and possibly Cold Bokkeveld (CM2) has been subjected to the past action of short duration thermal metamorphism, presumably triggered by impacts. The IOM in most of the CM chondrites that experienced moderate to heavy aqueous alteration may have been slightly modified by collision-induced heating. However, even IOM from chondrites that escaped significant thermal metamorphism displays Raman characteristics consistent with a formation by thermal processing, either in the protosolar disk or in the parent body. An alternative energetic process to thermal heating is ion irradiation. After thoroughly analyzing both these scenarii, no conclusion can be drawn as to which is the most plausible mechanism nor whether the heating process took place prior or after accretion. The results show for the first time that the width of the G band in spectra collected with a 514 nm excitation correlates with the O/C atomic ratio, suggesting a major role of oxygen in the cross-linking of polyaromatic units.

  7. Cyclodextrin-based telmisartan ophthalmic suspension: Formulation development for water-insoluble drugs.

    PubMed

    Muankaew, Chutimon; Jansook, Phatsawee; Sigurđsson, Hákon Hrafn; Loftsson, Thorsteinn

    2016-06-30

    In this study, cyclodextrin-based aqueous eye drop suspension of the water insoluble drug telmisartan was developed. Formation of a drug/γ-cyclodextrin complex was enabled by preventing formation of a poorly water-soluble zwitterion using a volatile base that was removed upon drying of the complex powder. Hydroxypropyl methylcellulose was shown to have the overall best effect, stabilizing the complexes without hampering the drug release from the formulation. Two strategies for preparing cyclodextrin-based aqueous eye drop suspensions of telmisartan were investigated, one where hydroxypropyl methylcellulose was added to the medium during preparation of the drug/γ-cyclodextrin complex powder (ternary complex) and the other where hydroxypropyl methylcellulose was added to the complex powder after preparation of the complex (binary complex). The complexation was characterized by DSC, FT-IR and (1)H NMR and the eye drop suspensions formed were examined regarding their stability and in vitro mucoadhesion property. The ternary complex exhibited inferior mucoadhesive property compared to the binary complex. However, the ternary complex was more stable as no notable change in particle size and particle size distribution was observed during storage at 4°C over 6 months (p<0.05) with the mean particle size determined between 2.0 and 2.5μm. PMID:27139144

  8. Vigorous Mold Growth in Soils After Addition of Water-Insoluble Fatty Substances

    PubMed Central

    Krause, Frank P.; Lange, Willy

    1965-01-01

    Various water-insoluble fatty compounds, when added to soil in finely divided form, will support as high-caloric nutrients a visible, vigorous growth of the molds, Fusarium solani Mart., F. diversisporum Sherb., and F. equiseti. n-Paraffins and olefins are most effective, because the effect of additives is reduced to the extent that oxygen atoms are introduced into the molecule. n-Fatty alcohols support growth in soil almost as well as the paraffins; however, growth is reduced when branched-chain compounds are added as nutrients. Compounds that will support mold growth when added to air-dried soil as finely powdered solids will not do so when incorporated at temperatures above their melting point, but will produce dense growth when applied to wet soil in this form. Mold growth is correlated with degradation of fatty matter. The rate of degradation is controlled by the availability of water, oxygen, and the basic inorganic nutrients. Images Fig. 1 Fig. 2 PMID:14325872

  9. KEY ELEMENTS OF CHARACTERIZING SAVANNAH RIVER SITE HIGH LEVEL WASTE SLUDGE INSOLUBLES THROUGH SAMPLING AND ANALYSIS

    SciTech Connect

    Reboul, S; Barbara Hamm, B

    2007-05-24

    Characterization of HLW is a prerequisite for effective planning of HLW disposition and site closure performance assessment activities. Adequate characterization typically requires application of a combination of data sources, including process knowledge, theoretical relationships, and real-waste analytical data. Consistently obtaining high quality real-waste analytical data is a challenge, particularly for HLW sludge insolubles, due to the inherent complexities associated with matrix heterogeneities, sampling access limitations, radiological constraints, analyte loss mechanisms, and analyte measurement interferences. Understanding how each of these complexities affects the analytical results is the first step to developing a sampling and analysis program that provides characterization data that are both meaningful and adequate. A summary of the key elements impacting SRS HLW sludge analytical data uncertainties is presented in this paper, along with guidelines for managing each of the impacts. The particular elements addressed include: (a) sample representativeness; (b) solid/liquid phase quantification effectiveness; (c) solids dissolution effectiveness; (d) analyte cross contamination, loss, and tracking; (e) dilution requirements; (f) interference removal; (g) analyte measurement technique; and (h) analytical detection limit constraints. A primary goal of understanding these elements is to provide a basis for quantifying total propagated data uncertainty.

  10. Model of molecular structure of the insoluble organic matter isolated from Murchison meteorite

    NASA Astrophysics Data System (ADS)

    Derenne, Sylvie; Robert, François

    2010-09-01

    The molecular structure of the insoluble organic matter (IOM) from Murchison meteorite has been investigated by our group for several years using a large set of analytical methods including various spectroscopies (Fourier transform infrared spectroscopy, nuclear magnetic resonance, electron paramagnetic resonance, X-ray absorption near-edge spectroscopy), high resolution electron microscopy, and thermal (pyrolyses in the presence or not of tetramethylammonium hydroxide) and chemical (RuO4 oxidation) degradations. Taken together, these techniques provided a wealth of qualitative and quantitative information, from which we derived 11 elemental and molecular parameters on the same IOM residue. In addition to the basic elemental composition, these parameters describe the distribution of the different types of carbon, nitrogen, and sulfur atoms as well as the size of the polyaromatic units. For this molecular structure, we therefore propose a model which fits with these 11 molecular quantitative parameters. Several cosmochemical implications are derived from this structure. Based on the fact that aromatic moieties are highly substituted and aliphatic chains highly branched, it can be anticipated that the synthesis of this IOM occurred through successive additions of single carbon units in the gas-phase ending by a spontaneous cyclization for chain length ≥7 C. As a whole, these observations favor an organosynthesis in the solar T-Tauri disk.

  11. Influence of drug physicochemical properties on absorption of water insoluble drug nanosuspensions.

    PubMed

    Li, Wei; Quan, Peng; Zhang, Yaqiong; Cheng, Jing; Liu, Jie; Cun, Dongmei; Xiang, Rongwu; Fang, Liang

    2014-01-01

    In order to investigate the influence of drug physicochemical properties on bioavailability of water insoluble drug nanosuspensions, five drug nanosuspensions were prepared using high pressure homogenization. These nanosuspensions were similar in particle size and same in stabilizer. Differential scanning calorimetry and powder X-ray diffraction analysis showed the crystalline state of the freeze dried nanocrystals did not change. In vitro dissolution test in fasted state simulated intestinal fluid (FaSSIF) and in vivo bioavailability study in rats demonstrated that the nanosuspensions had higher dissolution rate and higher AUC0-t and the ratios of dissolvednano/dissolvedmicro in 120 min were well correlated with the ratios of AUC0-t nano/AUC0-t micro. Correlation analysis between drug physicochemical properties and AUC0-t nano was performed and four-grid interpolation method was employed for interpolation and smooth surface fitting to give a visible trend. The results revealed that drug with smaller melting point, logP value around 5 and polar surface area value in the range of 50-60 would gain higher AUC0-t nano and accordingly better absorption of its nanosuspension. Melting point, logP and polar surface area were factors that influence the absorption of drug nanosuspensions in this study. PMID:24184036

  12. Water-insoluble fiber-rich fraction from pineapple peel improves intestinal function in hamsters: evidence from cecal and fecal indicators.

    PubMed

    Huang, Ya-Ling; Tsai, Yung-Hsiang; Chow, Chau-Jen

    2014-04-01

    Pineapple peel, a byproduct of agricultural processing, contains high levels of water-insoluble fiber-rich fraction (WIFF) (~42%, wt/wt). Our previous work has demonstrated that cellulose, hemicellulose (xylan and xyloglucan), and pectic substances are the major polysaccharides of pineapple-peel WIFF. Based on its chemical composition and unique characteristics, we hypothesized that daily consumption of WIFF would improve intestinal function in hamsters. Male Golden Syrian hamsters were fed a diet supplemented with either 5% cellulose or various amounts of WIFF (2.5%, 5%, or 10%). Activities of fecal bacterial enzymes, short-chain fatty acid concentrations, and microbial number in the cecal content, and also biochemical indicators in the cecal and feces of hamsters, were evaluated in all groups. The supplementation of WIFF in a diet at a level of 2.5% significantly (P < .05) decreased the daily fecal ammonia output; shortened the gastrointestinal transit time; reduced the activities of β-D-glucosidase, β-D-glucuronidase, mucinase, and urease in feces; and also enhanced the total amounts of short-chain fatty acid in the cecal content and the growth of gut microflora such as Lactobacillus spp and Bifidobacterium spp. These results indicate that WIFF could improve cecal ecosystem function of hamsters by reducing the toxic compounds excreted by intestinal microflora. Therefore, pineapple-peel WIFF could be a promising candidate for a functional ingredient beneficial to human intestinal function and health. PMID:24774071

  13. Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films

    DOEpatents

    Hankins, Matthew G.

    2009-10-06

    Etchant solutions comprising a redox buffer can be used during the release etch step to reduce damage to the structural layers of a MEMS device that has noble material films. A preferred redox buffer comprises a soluble thiophosphoric acid, ester, or salt that maintains the electrochemical potential of the etchant solution at a level that prevents oxidation of the structural material. Therefore, the redox buffer preferentially oxidizes in place of the structural material. The sacrificial redox buffer thereby protects the exposed structural layers while permitting the dissolution of sacrificial oxide layers during the release etch.

  14. Enzymatic characterization of peptidic materials isolated from aqueous solutions of ammonium cyanide (pH 9) and hydrocyanic acid (pH 6) exposed to ionizing radiation.

    PubMed

    Niketic, V; Draganić, Z; Nesković, S; Draganić, I

    1982-01-01

    The enzymatic digestion of some radiolytically produced peptidic materials was examined. The substrates were compounds isolated from 0.1 molar solutions of NH4CN (pH 9) and HCN (pH 6), after their exposure to gamma rays from a 60Co source (15-20 Mrad doses). Commercial proteolytic enzymes pronase and aminopeptidase M were used. The examined materials were of composite nature and proteolytic action was systematically observed after their subsequent purification. In some fractions the effect was found to be positive with up to 30% of peptide bonds cleaved with respect to the amino acid content. These findings support our previous conclusions on the free radical induced formation of peptidic backbones without the intervention of amino acids. Some side effects were also noted which might be of interest in observations on enzymatic cleavage of other composite peptidic materials of abiotic origin. PMID:6124639

  15. Selective extraction of derivates of p-hydroxy-benzoic acid from plant material by using a molecularly imprinted polymer.

    PubMed

    Karasová, Gabriela; Lehotay, Jozef; Sádecká, Jana; Skacáni, Ivan; Lachová, Miroslava

    2005-12-01

    Selective SPE of derivates of p-hydroxybenzoic acid (pHBA) from plant extract of Melissa officinalis is presented using a molecularly imprinted polymer (MIP) made with protocatechuic acid (PA) as template molecule. MIP was prepared with acrylamide as functional monomer, ethylene glycol dimethacrylate as crosslinking monomer and ACN as porogen. MIP was evaluated towards six phenolic acids: PA, gallic acid, pHBA, vanillic acid (VA), gentisic acid (GeA) and syringic acid (SyrA), and then steps of molecularly imprinted SPE (MISPE) procedure were optimized. The best specific binding capacity of MIP was obtained for PA in ACN (34.7 microg/g of MIP). Other tested acids were also bound on MIP if they were dissolved in this solvent. ACN was chosen as solvent for sample application. M. officinalis was extracted into methanol/water (4:1, v/v), the extract was then evaporated to dryness and dissolved in ACN before application on MIP. Water and ACN were used as washing solvents and elution of benzoic acids was performed by means of a mixture methanol/acetic acid (9:1, v/v). pHBA, GA, PA and VA were extracted with recoveries of 56.3-82.1% using this MISPE method. GeA was not determined in plant extract. PMID:16405176

  16. Biogeochemistry of suspended and sedimentary material in the Ob and Yenisei rivers and Kara Sea: amino acids and amino sugars

    NASA Astrophysics Data System (ADS)

    Unger, Daniela; Gaye-Haake, Birgit; Neumann, Kirsten; Catalina Gebhardt, A.; Ittekkot, Venugopalan

    2005-03-01

    Suspended particulate matter (SPM) and sediments were sampled in the Ob and the Yenisei rivers and the adjacent Kara Sea up to 77°N during the ice-free period in August and September 1997 (only sediments), 1999 and 2000. The material was analyzed for organic carbon (OC) and nitrogen (N) as well as for the content and monomeric composition of the labile organic constituents amino acids (AA) and amino sugars (AS). Despite interannual variation, surface SPM concentration generally revealed decreasing values from 8 to 4 mg/L for the Ob and Yenisei to values <0.5 mg/L in the offshore region reflecting the importance of fluvial input for SPM distribution. The quality of surface SPM was mainly determined by planktonic productivity as revealed by C/N, the content of AA+AS and their contribution to OC and N. Sedimentation caused a qualitative change of surface SPM at ˜ 73.5°N with POC-% averaging 6.7% south and 21% north of this latitude. This was accompanied by a change from 12-90 to 105-202 mg AA+AS/g SPM, respectively. Together with the monomeric composition of AA this indicates a higher reactivity of OM and a reduced dilution by detrital material in the offshore region. Whereas SPM was homogenously distributed in the rivers, the estuaries were characterized by a salt-wedge at depth. Deep water revealed highest SPM concentrations due to sediment resuspension and/or the presence of a nepheloid layer, which is mirrored in distinctively reduced OM content and reactivity relative to upper water column SPM. Compared to SPM, sediments are characterized by elevated contents of terrestrial OM in the southern study area especially off the Yenisei. OM content and reactivity decrease in offshore direction due to lower sedimentation rates and terrestrial OM input towards the north. The AA-derived reactivity index (RI) and degradation index (DI) together sensitively reflect the degradational stage of OM in SPM and sediments allowing a precise classification from fresh plankton

  17. Amorphous carbon nitride as an alternative electrode material in electroanalysis: simultaneous determination of dopamine and ascorbic acid.

    PubMed

    Medeiros, Roberta A; Matos, Roberto; Benchikh, Abdelkader; Saidani, Boualem; Debiemme-Chouvy, Catherine; Deslouis, Claude; Rocha-Filho, Romeu C; Fatibello-Filho, Orlando

    2013-10-01

    Boron-doped diamond (BDD) films are excellent electrode materials, whose electrochemical activity for some analytes can be tuned by controlling their surface termination, most commonly either to predominantly hydrogen or oxygen. This tuning can be accomplished by e.g. suitable cathodic or anodic electrochemical pretreatments. Recently, it has been shown that amorphous carbon nitride (a-CNx) films may present electrochemical characteristics similar to those of BDD, including the influence of surface termination on their electrochemical activity toward some analytes. In this work, we report for the first time a complete electroanalytical method using an a-CNx electrode. Thus, an a-CNx film deposited on a stainless steel foil by DC magnetron sputtering is proposed as an alternative electrode for the simultaneous determination of dopamine (DA) and ascorbic acid (AA) in synthetic biological samples by square-wave voltammetry. The obtained results are compared with those attained using a BDD electrode. For both electrodes, a same anodic pretreatment in 0.1 mol L(-1) KOH was necessary to attain an adequate and equivalent separation of the DA and AA oxidation potential peaks of about 330 mV. The detection limits obtained for the simultaneous determination of these analytes using the a-CNx electrode were 0.0656 μmol L(-1) for DA and 1.05 μmol L(-1) for AA, whereas with the BDD electrode these values were 0.283 μmol L(-1) and 0.968 μmol L(-1), respectively. Furthermore, the results obtained in the analysis of the analytes in synthetic biological samples were satisfactory, attesting the potential application of the a-CNx electrode in electroanalysis. PMID:24050667

  18. HUMAL ALVEOLAR MACROPHAGE RESPONSES TO AIR POLLUTION PARTICULATES ARE ASSOCIATED WITH INSOLUBLE OCMPONENTS OF COARSE MATERIAL, INCLUDING PARTICULATE ENDOTOXIN

    EPA Science Inventory


    Inhalation of particulate matter in the ambient air has been shown to cause pulmonary morbidity and exacerbate asthma. Alveolar macrophage (AM) are essential for effective removal of inhaled particles and microbes in the lower airways. While some particles minimally effect AM...

  19. Evidence for bias in measured δ15N values of terrestrial and aquatic organic materials due to pre-analysis acid treatment methods.

    PubMed

    Brodie, Chris R; Heaton, Tim H E; Leng, Melanie J; Kendrick, Christopher P; Casford, James S L; Lloyd, Jeremy M

    2011-04-30

    We investigate the effect of acid treatment methods on δ(15)N values from a range of environmental organic materials in the context of the increased application of 'dual-mode' isotope analysis (the simultaneous measurement of δ(13)C and δ(15)N from the same acid-treated sample). Three common methods are compared; (i) untreated samples; (ii) acidification followed by sequential water rinse (rinse method); and (iii) acidification in silver capsules (capsule method). The influence of capsule type (silver and tin) on δ(15)N is also independently assessed (as the capsule and rinse methods combust samples in different capsules; silver and tin, respectively). We find significant differences in δ(15)N values between methods and the precision of any one method varies significantly between sample materials and above the instrument precision (>0.3‰). The δ(15)N values of untreated samples did not produce the most consistent data on all sample materials. In addition, the capsule type appears to influence the measured δ(15)N value of some materials, particularly those combusted only in silver capsules. We also compare the new δ(15)N data with previously published δ(13)C data on the same materials. The response of δ(13)C and δ(15)N within and between methods and sample materials to acidification appears to be relatively disproportionate, which can influence the environmental interpretation of the measured data. In addition, statistical methods used to estimate inorganic nitrogen are shown to be seriously flawed. PMID:21452387

  20. Origin of Initial Burst in Activity for Trichoderma reesei endo-Glucanases Hydrolyzing Insoluble Cellulose*

    PubMed Central

    Murphy, Leigh; Cruys-Bagger, Nicolaj; Damgaard, Heidi Delcomyn; Baumann, Martin J.; Olsen, Søren Nymand; Borch, Kim; Lassen, Søren Flensted; Sweeney, Matt; Tatsumi, Hirosuke; Westh, Peter

    2012-01-01

    The kinetics of cellulose hydrolysis have longbeen described by an initial fast hydrolysis rate, tapering rapidly off, leading to a process that takes days rather than hours to complete. This behavior has been mainly attributed to the action of cellobiohydrolases and often linked to the processive mechanism of this exo-acting group of enzymes. The initial kinetics of endo-glucanases (EGs) is far less investigated, partly due to a limited availability of quantitative assay technologies. We have used isothermal calorimetry to monitor the early time course of the hydrolysis of insoluble cellulose by the three main EGs from Trichoderma reesei (Tr): TrCel7B (formerly EG I), TrCel5A (EG II), and TrCel12A (EG III). These endo-glucanases show a distinctive initial burst with a maximal rate that is about 5-fold higher than the rate after 5 min of hydrolysis. The burst is particularly conspicuous for TrCel7B, which reaches a maximal turnover of about 20 s−1 at 30 °C and conducts about 1200 catalytic cycles per enzyme molecule in the initial fast phase. For TrCel5A and TrCel12A the extent of the burst is 2–300 cycles per enzyme molecule. The availability of continuous data on EG activity allows an analysis of the mechanisms underlying the initial kinetics, and it is suggested that the slowdown is linked to transient inactivation of enzyme on the cellulose surface. We propose, therefore, that the frequency of structures on the substrate surface that cause transient inactivation determine the extent of the burst phase. PMID:22110134

  1. Improved dissolution of an insoluble drug using a 4-fluid nozzle spray-drying technique.

    PubMed

    Chen, Richer; Tagawa, Maya; Hoshi, Noboru; Ogura, Toshihiro; Okamoto, Hirokazu; Danjo, Kazumi

    2004-09-01

    A solid dispersion of the drug can be made using a polymer carrier to improve solubility. Generally, drugs become amorphized when solid dispersion is formed using a polymer carrier. In such high energy conditions, the solubility of the drug molecule is increased. We previously prepared solid dispersion using a spray-drying technique and reported its solubility and crystallinity. In this study, hydroxypropylmethylcellulose (HPMC) was used as the carrier, and tolubutamide was the model drug, which is water-insoluble. Solubility was evaluated by preparing a solid dispersion using a newly developed 4-fluid nozzle spray dryer. Observation of particle morphology by scanning electron microscopy (SEM) revealed that the particles from the spray drying were atomized to several microns, and they had also become spherical. Assessment of the crystallinity of the spray-dried particles by powder X-ray diffraction and differential scanning calorimetry demonstrated that the tolbutamide had been amorphized, forming a solid dispersion. The apparent release rate constant K of the drug from the spray-dried particles was 4 to 6 times faster than the original drug in pH 1.2, and it was also 1.5 to 1.9 times faster than the original drug in pH 6.8. The 70% release time (T(70)) of the drug from the spray-dried particles was 20 to 30 times faster than the original drug in pH 1.2 solution as well as 2 to 3 times faster than the original drug in pH 6.8 solution. Pharmaceutical preparations prepared in this way using the 4-fluid nozzle system spray dryer formed composite particles, resulting in a remarkably improved dissolution rates of the drug. PMID:15340191

  2. Glass ceramics containment matrix for insoluble residues coming from spent fuel reprocessing

    NASA Astrophysics Data System (ADS)

    Pinet, O.; Boën, R.

    2014-04-01

    Spent fuel reprocessing by hydrometallurgical process generates insoluble residues waste streams called fines solution. Considering their radioactivity, fines solution could be considered as Intermediate Level Waste. This waste stream is usually mixed with fission products stream before vitrification. Thus fines are incorporated in glass matrix designed for High Level Waste. The withdrawal of fines from high level glass could decrease the volume of high level waste after conditioning. It could also decrease the reaction time between high level waste and additives to obtain a homogeneous melt and then increase the vitrification process capacity. Separated conditioning of fines in glass matrices has been tested. The fines content targeted value is 16 wt%. To achieve this objective, two types of glass ceramic formulations have been tested. 700 g of the two selected glass ceramics have been prepared using simulated fines. Additives used were ground glass. Melting is achieved at 1100 °C. According to the type of glass ceramic, reducing or oxidizing conditions have been performed during melting. Due to their composition and the melting redox conditions, different phases have been observed. These crystalline phases are typically RuO2, metallic Ru, metallic Pd, MoO2 and CaMoO4. In view of melting these matrices in an in can process the corrosiveness of one of the most oxidizing borosilicate glass ceramic formulation has been tested. This one has been remelted at 1100 °C in inconel 601 pot for 3 days. The oxygen fugacity measurement performed in the remelted glass leads to an oxidizing value, indicating that no significant reaction occurred between the inconel pot and the glass melt had occurred.

  3. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration

    PubMed Central

    Clunes, Lucy A.; Davies, Catrin M.; Coakley, Raymond D.; Aleksandrov, Andrei A.; Henderson, Ashley G.; Zeman, Kirby L.; Worthington, Erin N.; Gentzsch, Martina; Kreda, Silvia M.; Cholon, Deborah; Bennett, William D.; Riordan, John R.; Boucher, Richard C.; Tarran, Robert

    2012-01-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB.—Clunes, L. A., Davies, C. M., Coakley, R. D., Aleksandrov, A. A., Henderson, A. G., Zeman, K. L., Worthington, E. N., Gentzsch, M., Kreda, S. M., Cholon, D., Bennett, W. D., Riordan, J. R., Boucher, R. C., Tarran, R. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration. PMID:21990373

  4. Marine sediments microbes capable of electrode oxidation as a surrogate for lithotrophic insoluble substrate metabolism

    PubMed Central

    Rowe, Annette R.; Chellamuthu, Prithiviraj; Lam, Bonita; Okamoto, Akihiro; Nealson, Kenneth H.

    2015-01-01

    Little is known about the importance and/or mechanisms of biological mineral oxidation in sediments, partially due to the difficulties associated with culturing mineral-oxidizing microbes. We demonstrate that electrochemical enrichment is a feasible approach for isolation of microbes capable of gaining electrons from insoluble minerals. To this end we constructed sediment microcosms and incubated electrodes at various controlled redox potentials. Negative current production was observed in incubations and increased as redox potential decreased (tested −50 to −400 mV vs. Ag/AgCl). Electrode-associated biomass responded to the addition of nitrate and ferric iron as terminal electron acceptors in secondary sediment-free enrichments. Elemental sulfur, elemental iron and amorphous iron sulfide enrichments derived from electrode biomass demonstrated products indicative of sulfur or iron oxidation. The microbes isolated from these enrichments belong to the genera Halomonas, Idiomarina, Marinobacter, and Pseudomonas of the Gammaproteobacteria, and Thalassospira and Thioclava from the Alphaproteobacteria. Chronoamperometry data demonstrates sustained electrode oxidation from these isolates in the absence of alternate electron sources. Cyclic voltammetry demonstrated the variability in dominant electron transfer modes or interactions with electrodes (i.e., biofilm, planktonic or mediator facilitated) and the wide range of midpoint potentials observed for each microbe (from 8 to −295 mV vs. Ag/AgCl). The diversity of extracellular electron transfer mechanisms observed in one sediment and one redox condition, illustrates the potential importance and abundance of these interactions. This approach has promise for increasing our understanding the extent and diversity of microbe mineral interactions, as well as increasing the repository of microbes available for electrochemical applications. PMID:25642220

  5. Time-dependent association between platelet-bound fibrinogen and the Triton X-100 insoluble cytoskeleton

    SciTech Connect

    Peerschke, E.I. )

    1991-02-01

    Previous studies indicated a correlation between the formation of EDTA-resistant (irreversible) platelet-fibrinogen interactions and platelet cytoskeleton formation. The present study explored the direct association of membrane-bound fibrinogen with the Triton X-100 insoluble cytoskeleton of aspirin-treated, gel-filtered platelets, activated but not aggregated with 20 mumol/L adenosine diphosphate (ADP) or 150 mU/mL human thrombin (THR) when bound fibrinogen had become resistant to dissociation by EDTA. Conversion of exogenous 125I-fibrinogen to fibrin was prevented by adding Gly-Pro-Arg and neutralizing THR with hirudin before initiating binding studies. After 60 minutes at 22 degrees C, the cytoskeleton of ADP-treated platelets contained 20% +/- 12% (mean +/- SD, n = 14) of membrane-bound 125I-fibrinogen, representing 10% to 50% of EDTA-resistant fibrinogen binding. The THR-activated cytoskeleton contained 45% +/- 15% of platelet bound fibrinogen, comprising 80% to 100% of EDTA-resistant fibrinogen binding. 125I-fibrinogen was not recovered with platelet cytoskeletons if binding was inhibited by the RGDS peptide, excess unlabeled fibrinogen, or disruption of the glycoprotein (GP) IIb-IIIa complex by EDTA-treatment. Both development of EDTA-resistant fibrinogen binding and fibrinogen association with the cytoskeleton were time dependent and reached maxima 45 to 60 minutes after fibrinogen binding to stimulated platelets. Although a larger cytoskeleton formed after platelet stimulation with thrombin as compared with ADP, no change in cytoskeleton composition was noted with development of EDTA-resistant fibrinogen binding.

  6. Scavenging insoluble light-absorbing particulates (ILAP) in seasonal snow over northern China

    NASA Astrophysics Data System (ADS)

    Wang, X.; Huang, J.

    2013-12-01

    It has been long believed that Black Carbon (BC) from biomass burning, fossil fuel and biofuel plays an important role in the earth's system through its climate effect. Compared with other insoluble light-absorbing particulates (ILAP), BC is a main component of the most effective light-absorbing particulates, which can dominates the absorption of solar radiation at the visible wavelengths. Furthermore, once deposits on snow, it could significant reduces the snow reflectance and accelerate the snow melting, therefore, it is considered as the second most important component as the CO2 to affect the globe warming. Although several experiments have already been performed for collecting and measuring the scavenging BC in snow on a global scale. Little attention has been given to the quantitative measurements of ILAP deposit on the snowpack at mid-latitude regions in Asia, especially over Northern China. Recently, there are two field campaigns were conducted in January and February 2010 and 2012 to measuring the ILAP in snow across northern China. About 700 snow samples were collected at 84 sites in seven provinces. The BC mass fractions in seasonal snow across northern Xinjiang have a median value of 70 ng g-1, and the concentrations of BC were in the remote northeast on the border of Siberia, with a median concentration in surface snow of 120 ng g-1. South of this, in the industrial northeast, the median snow BC concentration was 1200 ng g-1. In the northeast, snow particulate light absorption was dominated by BC. Across the grassland of Inner Mongolia, OC, likely mostly from local soil, dominates light absorption, with median BC concentrations of 340 ng g-1 responsible for only about one third of total particulate light absorption. In the Qilian Mountains, at the northern boundary of the Tibetan Plateau, snow particulate light absorption is dominated by local soil and desert dust.

  7. When do water-insoluble polyion-surfactant ion complex salts "redissolve" by added excess surfactant?

    PubMed

    dos Santos, Salomé; Gustavsson, Charlotte; Gudmundsson, Christian; Linse, Per; Piculell, Lennart

    2011-01-18

    The redissolution of water-insoluble polyion-surfactant ion complexes by added excess of surfactant has systematically been investigated in experimental and theoretical phase equilibrium studies. A number of stoichiometric polyion-surfactant ion "complex salts" were synthesized and they consisted of akyltrimethylammonium surfactant ions of two different alkyl chain lengths (C(12)TA(+) and C(16)TA(+)) combined with homopolyions of polyacrylate of two different lengths (PA(-)(25) and PA(-)(6000)) or copolyions of acrylate and the slightly hydrophobic nonionic comonomers N-isopropylacrylamide (PA(-)-co-NIPAM) or N,N-dimethylacrylamide (PA(-)-co-DAM). The complex salts were mixed with water and excess alkyltrimethylammonium surfactant with either bromide or acetate counterions (C(n)TABr or C(n)TAAc). Factors promoting efficient redissolution were (i) very short polyions, (ii) a large fraction of NIPAM or DAM comonomers, and (iii) acetate, rather than bromide, as the surfactant counterion. Added C(12)TAAc gave an efficient redissolution of C(12)TAPA(25) but virtually no redissolution of C(12)TAPA(6000). A very efficient redissolution by added C(12)TAAc was obtained for PA(-)-co-NIPAM with 82 mol % of NIPAM. The C(12)TAPA-co-NIPAM/C(12)TAAc/H(2)O ternary phase diagram closely resembled the corresponding diagram for the much-studied pair cationic hydroxyethyl cellulose-(sodium) dodecyl sulfate. The simple Flory-Huggins theory adopted for polyelectrolyte systems successfully reproduced the main features of the experimental phase diagrams for the homopolyion systems, including the effect of the surfactant counterion. The efficient redissolution found for certain copolyion systems was explained by the formation of soluble polyion-surfactant ion complexes carrying an excess of surfactant ions through an additional hydrophobic attraction. PMID:21166446

  8. Marine sediments microbes capable of electrode oxidation as a surrogate for lithotrophic insoluble substrate metabolism.

    PubMed

    Rowe, Annette R; Chellamuthu, Prithiviraj; Lam, Bonita; Okamoto, Akihiro; Nealson, Kenneth H

    2014-01-01

    Little is known about the importance and/or mechanisms of biological mineral oxidation in sediments, partially due to the difficulties associated with culturing mineral-oxidizing microbes. We demonstrate that electrochemical enrichment is a feasible approach for isolation of microbes capable of gaining electrons from insoluble minerals. To this end we constructed sediment microcosms and incubated electrodes at various controlled redox potentials. Negative current production was observed in incubations and increased as redox potential decreased (tested -50 to -400 mV vs. Ag/AgCl). Electrode-associated biomass responded to the addition of nitrate and ferric iron as terminal electron acceptors in secondary sediment-free enrichments. Elemental sulfur, elemental iron and amorphous iron sulfide enrichments derived from electrode biomass demonstrated products indicative of sulfur or iron oxidation. The microbes isolated from these enrichments belong to the genera Halomonas, Idiomarina, Marinobacter, and Pseudomonas of the Gammaproteobacteria, and Thalassospira and Thioclava from the Alphaproteobacteria. Chronoamperometry data demonstrates sustained electrode oxidation from these isolates in the absence of alternate electron sources. Cyclic voltammetry demonstrated the variability in dominant electron transfer modes or interactions with electrodes (i.e., biofilm, planktonic or mediator facilitated) and the wide range of midpoint potentials observed for each microbe (from 8 to -295 mV vs. Ag/AgCl). The diversity of extracellular electron transfer mechanisms observed in one sediment and one redox condition, illustrates the potential importance and abundance of these interactions. This approach has promise for increasing our understanding the extent and diversity of microbe mineral interactions, as well as increasing the repository of microbes available for electrochemical applications. PMID:25642220

  9. Preparation of surface imprinted material of single enantiomer of mandelic acid with a new surface imprinting technique and study on its chiral recognition and resolution properties.

    PubMed

    Gao, Baojiao; Chen, Lulu; Li, Yanbin

    2016-04-22

    A surface imprinted material of the single enantiomer of mandelic acid with high performance was successfully prepared with a new surface imprinting technique of synchronously graft-polymerizing and molecule imprinting, and its enantiomeric recognition and resolution properties were investigated. Micro-sized silica gel particles were first modified with coupling agent γ-mercaptopropyl trimethoxysilane (MPMS), obtaining the modified particles MPMS-SiO2 on which mercapto groups were introduced. A surface initiating system of -SH/BPO was constituted with the mercapto group (-SH) on MPMS-SiO2 particles and dibenzoyl peroxide (BPO) in N,N-dimethyl formamide (DMF) solution. In DMF solution, (R)-mandelic acid molecule was used as the template and the functional monomer hydroxyethyl methylacrylate (HEMA) were combined together by right of multi-site hydrogen bonds. The free radicals produced on MPMS-SiO2 particles initiate HEMA molecules around (R)-mandelic acid molecules and the crosslinking agent N,N'-Methylenebisacrylamide (MBA) to produce graft/crosslinking-polymerization. At the same time, the template (R)-mandelic acid molecules were enveloped within the thin grafted polymer layer on the surfaces of SiO2 particles, obtaining (R)-mandelic acid surface imprinted material MIP-PHEMA/SiO2. The experimental results show that MIP-PHEMA/SiO2 particles have excellent enantiomeric recognition and resolution ability. The binding capacity of MIP-PHEMA/SiO2 particles for (R)-mandelic acid reaches up to 278mg/g. As the resolution experiment of a racemic mixture was carried out with MIP-PHEMA/SiO2 particles as solid adsorbent, relative another enantiomer, (S)-mandelic acid, the selectivity coefficient of the imprinted particles for (R)-mandelic acid is 5.02. As a consequence, the two enantiomers were well separated, and the optical purities (ee values) of the supernatant and eluant get up to 44% (corresponding to (S)-mandelic acid excess) and 85% (corresponding to (R

  10. Development of an analytical method to measure insoluble and soluble starch in sugarcane and sweet sorghum products.

    PubMed

    Cole, Marsha R; Eggleston, Gillian; Gilbert, Audrey; Chung, Yoo Jin

    2016-01-01

    A rapid research method using microwave-assisted probe ultrasonication was developed to quantify total, insoluble, and soluble starch in various sugar crop products. Several variables affecting starch solubilisation were evaluated, (1) heating method, (2) boiling time, (3) probe ultrasonication time, (4) water loss, (5) concentration, (6) sample colour, and (7) sample. The optimised method solubilises < 40,000 ppm insoluble starch with microwave-assisted sonication in 6 min, has acceptable precision (<6% CV), accuracy (⩾ 95%), uses a corn starch reference, and incorporates a colour blank to remove contribution from natural colourants found in industrial samples. This method was validated using factory samples and found applicable to sugarcane and sweet sorghum bagasse (3% CV), mixed juices (2%), massecuites (4%), molasses (7%), and raw sugars (12%), 100% satisfactory performance z-scores were also obtained. Total starch values obtained with this method were significantly higher than those measured using other methods presently accepted by the sugar industry. PMID:26212940

  11. Thermoresponsive Interplay of Water Insoluble Poly(2-alkyl-2-oxazoline)s Composition and Supramolecular Host–Guest Interactions

    PubMed Central

    R. de la Rosa, Victor; Nau, Werner M.; Hoogenboom, Richard

    2015-01-01

    A series of water insoluble poly[(2-ethyl-2-oxazoline)-ran-(2-nonyl-2-oxazoline)] amphiphilic copolymers was synthesized and their solubility properties in the presence of different supramolecular host molecules were investigated. The resulting polymer-cavitand assemblies exhibited a thermoresponsive behavior that could be modulated by variation of the copolymer composition and length. Interestingly, the large number of hydrophobic nonyl units across the polymer chain induced the formation of kinetically-trapped nanoparticles in solution. These nanoparticles further agglomerate into larger aggregates at a temperature that is dependent on the polymer composition and the cavitand type and concentration. The present research expands the understanding on the supramolecular interactions between water insoluble copolymers and supramolecular host molecules. PMID:25849653

  12. 21 CFR 172.850 - Lactylated fatty acid esters of glycerol and propylene glycol.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) The additive meets the following specifications: Water insoluble combined lactic acid, 14-18 percent... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Lactylated fatty acid esters of glycerol and... CONSUMPTION Multipurpose Additives § 172.850 Lactylated fatty acid esters of glycerol and propylene...

  13. Venus clouds - A dirty hydrochloric acid model.

    NASA Technical Reports Server (NTRS)

    Hapke, B.

    1972-01-01

    The spectral and polarization data for Venus are consistent with micrometer-sized aerosol cloud particles of hydrochloric acid with soluble and insoluble iron compounds, whose source could be volcanic or crustal dust. The yellow color of the clouds could be due to absorption bands in the near UV involving ferric iron and chlorine complexes. It is pointed out that the UV features could arise from variations in the concentrations of iron and hydrochloric acid in the cloud particles.

  14. ELECTROLYTIC REDUCTION OF NITRIC ACID SOLUTIONS

    DOEpatents

    Alter, H.W.; Barney, D.L.

    1958-09-30

    A process is presented for the treatment of radioactivc waste nitric acid solutions. The nitric acid solution is neutralized with an alkali metal hydroxide in an amount sufficient to precipitate insoluble hydroxides, and after separation of the precipitate the solution is electrolyzed to convert the alkali nitrate formed, to alkali hydroxide, gaseous ammonla and oxygen. The solution is then reusable after reducing the volume by evaporating the water and dissolved ammonia.

  15. Difference in Surface Properties between Insoluble Monolayer and Adsorbed Film from Kinetics of Water Evaporation and BAM Image.

    PubMed

    Moroi, Yoshikiyo; Rusdi, Muhammad; Kubo, Izumi

    2004-05-20

    The evaporation rate of water molecules across three kinds of interfaces (air/water interface (1), air/surfactant solution interface (2), and air/water interface covered by insoluble monolayer (3)) was examined using a remodeled thermogravimetric balance. There was no difference in both the evaporation rate and the activation energy for the first two interfaces for three types of surfactant solutions below and above the critical micelle concentration (cmc). This means that the molecular surface area from the Gibbs surface excess has nothing to do with the evaporation rate. In the third case, the insoluble monolayer of 1-heptadecanol decreased the evaporation rate and increased the activation energy, indicating a clear difference between an insoluble monolayer and an adsorbed film of soluble surfactant. This difference was substantiated by BAM images, too. The images of three surfactant solution interfaces were similar to that of just the water surface, while distinct structures of molecular assemblies were observed for the insoluble monolayer. The concentration profile of water molecules in an air/liquid interfacial region was derived by Fix's second law. The profile indicates that a definite layer just beneath the air/liquid interface of the surfactant solution is made mostly of water molecules and that the layer thickness is a few times the root-mean-square displacement %@mt;sys@%%@rl;;@%2%@ital@%Dt%@rsf@%%@rlx@%%@mx@% of the water molecules. The thickness was found to be more than a few nanometers, as estimated from several relaxation times derived from the other kinetics than evaporation of amphiphilic molecules in aqueous systems and a maximum evaporation rate of purified water. PMID:18950121

  16. Role of different additives and metallic micro minerals on the enhanced citric acid production by Aspergillus niger MNNG-115 using different carbohydrate materials.

    PubMed

    Ali, Sikander; Haq, Ikram-ul

    2005-01-01

    The present investigation deals with the promotry effect of different additives and metallic micro minerals on citric acid production by Aspergillus niger MNNG-115 using different carbohydrate materials. For this, sugar cane bagasse was fortified with sucrose salt medium. Ethanol and coconut oil at 3.0% (v/w) level increased citric acid productivity. Fluoroacetate at a concentration of 1.0 mg/ml bagasse enhanced the yield of citric acid significantly. However, the addition of ethanol and fluoroacetate after 6 h of growth gave the maximum conversion of available sugar to citric acid. In another study, influence of some metallic micro-minerals viz. copper sulphate, molybdenum sulphate, zinc sulphate and cobalt sulphate on microbial synthesis of citric acid using molasses medium was also carried out. It was found that copper sulphate and molybdenum sulphate remarkably enhanced the production of citric acid while zinc sulphate was not so effective. However, cobalt sulphate was the least effective for microbial biosynthesis of citric acid under the same experimental conditions. In case of CuSO(4), the strain of Aspergillus niger MNNG-115 showed enhanced citric productivity with experimental (9.80%) over the control (7.54%). In addition, the specific productivity of the culture at 30 ppm CuSO(4) (Q(p) = 0.012a g/g cells/h) was several folds higher than other all other concentrations. All kinetic parameters including yield coefficients and volumetric rates revealed the hyper productivity of citric acid by CuSO(4) using blackstrap molasses as the basal carbon source. PMID:15678560

  17. Numerical modeling of the transport to an intravascular bubble in a tube with a soluble/insoluble surfactant.

    PubMed

    Ayyaswamy, Portonovo S; Zhang, Jie; Eckmann, David M

    2006-09-01

    Using a newly developed algorithm in conjunction with the front tracking scheme, we have evaluated the transport associated with a deformable bubble moving in a tube in the presence of a soluble or an insoluble surfactant. Such evaluations are useful to the understanding of gas embolism--a common syndrome for decompression sickness. Decompression sickness may be encountered in performing extravehicular activity during space exploration. The numerical evaluations indicate that as the location of the adsorptive interface gets closer to the vessel wall, the surfactant amount on the wall gets depleted. The implication is that the process by which a bubble occluding a vessel dislodges may depend both on the strength of the diffusivity of the surfactant and the adsorption process. More detailed study is needed to clarify this observation. The numerical results evaluated include Marangoni flow, which causes a bubble to propel out of its initial static location, and bubble motion in Poiseuille flow. The presence of a soluble/insoluble surfactant slows down the bubble motion. For identical surface concentrations of the surfactant, the effect of the presence of a soluble surfactant is more severe on the retardation of the bubble motion than that of an insoluble surfactant. PMID:17124130

  18. Examination of organic compounds from insoluble organic matter isolated from some Antarctic carbonaceous chondrites by heating experiments

    NASA Astrophysics Data System (ADS)

    Komiya, M.; Shimoyama, A.; Harada, K.

    1993-02-01

    Insoluble organic matter isolated from five Antarctic CM2 chondrites was heated in a thermal analyzer from room temperature to 800 C under helium atmosphere. Organic compounds from the thermal decomposition of the Yamato-791198 sample were studied by a gas chromatograph-mass spectrometer (GC-MS). The number of compounds identified was over 120, belonging mainly to the two following groups: (1) benzene and naphthalene, and their alkyl derivatives; and (2) sulfur-containing heterocycles and their alkyl derivatives. Small amounts of aliphatic hydrocarbons and nitriles were also detected. Relative amounts of compounds released from the five chondrite samples were monitored by the MS with increasing temperature. Yamato-74662 and Yamato-791198 showed organic compounds mainly over the temperature range of 300-600 C, while the other three (Yamato-793321, Yamato-86720, and Belgica-7904) did not show any, except small amounts of benzene. These results indicate that the insoluble organics in Yamato-74662 and Yamato-791198 possess a thermally labile organic fraction, whereas those in Yamato-793321, Yamato-86720, and Belgica-7904 do not and are graphitic. The difference between the insoluble organic fractions may be related to aqueous alteration and thermal metamorphism on the parent bodies.

  19. MCM-41 supported 12-tungstophosphoric acid mesoporous materials: Preparation, characterization, and catalytic activities for benzaldehyde oxidation with H2O2

    NASA Astrophysics Data System (ADS)

    Chen, Ya; Zhang, Xiao-Li; Chen, Xi; Dong, Bei-Bei; Zheng, Xiu-Cheng

    2013-10-01

    Mesoporous molecular sieves MCM-41 and bulk 12-tungstophosphoric acid (HPW) were synthesized and employed to prepare 5-45 wt.% HPW/MCM-41 mesoporous materials. Characterization results suggested the good dispersion of HPW within MCM-41 when the loading of HPW was less than 35 wt.% and HPW/MCM-41 retained the typical mesopore structure of the supports. The results of the catalytic oxidation of benzaldehyde to benzoic acid with 30% H2O2, in the absence of any organic solvent and co-catalysts, indicated that HPW/MCM-41 was an efficient catalyst and 30 wt.% HPW/MCM-41 sample exhibited the highest catalytic activity among these materials.

  20. Metal-organic hybrid materials built with tetrachlorophthalate acid and different N-donor coligands: Structure diversity and photoluminescence

    NASA Astrophysics Data System (ADS)

    Xiao, Zhenyu; Yang, Xiao; Zhao, Siwei; Wang, Debao; Yang, Yu; Wang, Lei

    2016-02-01

    Eight new metal-organic hybrid materials, namely {Cd(Tcph)(4,4‧-bipy)1/2} (1), {[Cd2(Tcph)2(1,4-bimb)1/2(H2O)4]·H2O} (2), {Cd2(Tcph)2(1,4-bmimb)1/2(H2O)4} (3), {Cd(Tcph)(1,2-bmimb)} (4), {Cu(Tcph)(1,4-bimb)(H2O)} (5), {[Co(Tcph)(1,4-bimb)1/2(H2O)3]·(H2O)} (6), {Zn(Tcph)(1,2-bimb)} (7), {Cu2(Tcph)2(1,2-bimb)(H2O)4} (8), where Tcph=tetrachlorophthalate acid, 4,4‧-bipy=4,4‧-bipyridine, 1,4-bimb=1,4-bis(imidazol-1-ylmethyl)benzene, 1,4-bmimb=1,4-bis(2-methylimidazol-1-ylmethyl)benzene, 1,2-bimb=1,2-bis(imidazol-1-ylmethyl)-benzene, 1,2-bmimb=1,2-bis(2-methylimidazol-1-ylmethyl)benzene, have been synthesized and characterized. Their structures are determined by single crystal X-ray diffraction and further characterized by infrared spectra (IR) and thermogravimetric (TG) analyses. Complex 1, 4 and 7 display 2D layer structures. 1 possesses two-dimensional sheet containing an unusual [Cd(Tcph)] chains linked by 4,4‧-bipy co-ligand, while 4 and 7 hold the similar 4-connected 44-sql nets. Complex 2 and 3 feature a similar three dimensional (3D) internal compensation structure with a topology of {42·63·8}2{63}. 5 is a novel 2-fold self-penetrating 3D network with 4-coordinated 65·8-CdSO4 subnets. The ladder-like chains of 6 are further connected through O-H···O interactions to yield a 3D supramolecular structure. 8 is a discrete tetranuclear complex. The thermal stabilities of 1-8 and the luminescent properties of 1-4 and 7 in the solid state are also discussed.