Science.gov

Sample records for acid detergent fibre

  1. Restricting detergent protease action to surface of protein fibres by chemical modification.

    PubMed

    Schroeder, M; Lenting, H B M; Kandelbauer, A; Silva, C J S M; Cavaco-Paulo, A; Gübitz, G M

    2006-10-01

    Due to their excellent properties, such as thermostability, activity over a broad range of pH and efficient stain removal, proteases from Bacillus sp. are commonly used in the textile industry including industrial processes and laundry and represent one of the most important groups of enzymes. However, due to the action of proteases, severe damage on natural protein fibres such as silk and wool result after washing with detergents containing proteases. To include the benefits of proteases in a wool fibre friendly detergent formulation, the soluble polymer polyethylene glycol (PEG) was covalently attached to a protease from Bacillus licheniformis. In contrast to activation of PEG with cyanuric chloride (50%) activation with 1,1'-carbonyldiimidazole (CDI) lead to activity recovery above 90%. With these modified enzymes, hydrolytic attack on wool fibres could be successfully prevented up to 95% compared to the native enzymes. Colour difference (DeltaE) measured in the three dimensional colour space showed good stain removal properties for the modified enzymes. Furthermore, half-life of the modified enzymes in buffers and commercial detergents solutions was nearly twice as high as those of the non-modified enzymes with values of up to 63 min. Out of the different modified proteases especially the B. licheniformis protease with the 2.0-kDa polymer attached both retained stain removal properties and did not hydrolyse/damage wool fibres.

  2. Effects of replacing dietary starch with neutral detergent-soluble fibre on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria using the rumen simulation technique (RUSITEC).

    PubMed

    Zhao, X H; Liu, C J; Liu, Y; Li, C Y; Yao, J H

    2013-12-01

    A rumen simulation technique (RUSITEC) apparatus with eight 800 ml fermenters was used to investigate the effects of replacing dietary starch with neutral detergent-soluble fibre (NDSF) by inclusion of sugar beet pulp in diets on ruminal fermentation, microbial synthesis and populations of ruminal cellulolytic bacteria. Experimental diets contained 12.7, 16.4, 20.1 or 23.8% NDSF substituted for starch on a dry matter basis. The experiment was conducted over two independent 15-day incubation periods with the last 8 days used for data collection. There was a tendency that 16.4% NDSF in the diet increased the apparent disappearance of organic matter (OM) and neutral detergent fibre (NDF). Increasing dietary NDSF level increased carboxymethylcellulase and xylanase activity in the solid fraction and apparent disappearance of acid detergent fibre (ADF) but reduced the 16S rDNA copy numbers of Ruminococcus albus in both liquid and solid fractions and R. flavefaciens in the solid fraction. The apparent disappearance of dietary nitrogen (N) was reduced by 29.6% with increased dietary NDSF. Substituting NDSF for starch appeared to increase the ratios of acetate/propionate and methane/volatile fatty acids (VFA) (mol/mol). Replacing dietary starch with NDSF reduced the daily production of ammonia-N and increased the growth of the solid-associated microbial pellets (SAM). Total microbial N flow and efficiency of microbial synthesis (EMS), expressed as g microbial N/kg OM fermented, tended to increase with increased dietary NDSF, but the numerical increase did not continue as dietary NDSF exceeded 20.1% of diet DM. Results suggested that substituting NDSF for starch up to 16.4% of diet DM increased digestion of nutrients (except for N) and microbial synthesis, and further increases (from 16.4% to 23.8%) in dietary NDSF did not repress microbial synthesis but did significantly reduce digestion of dietary N.

  3. Microbial ecosystem and fermentation traits in the caecum of growing rabbits given diets varying in neutral detergent soluble and insoluble fibre levels.

    PubMed

    Rodríguez-Romero, Norelys; Abecia, Leticia; Fondevila, Manuel

    2013-04-01

    The effect of the level of neutral detergent fibre (NDF: 0.35, LI and 0.42, HI) and neutral detergent soluble fibre (NDSF: 0.14, LS and 0.17, HS) in the caecal ecosystem was studied in 24 weaned (28 days of age) rabbits, weighing 630 ± 80.2 g in a 2 × 2 factorial design. After 22 days, rabbits were slaughtered and their caecal contents sampled. The caecal pH (on average 6.2) and molar volatile fatty acids (VFA) proportions were not affected by dietary treatments, but total VFA concentration tended to be lower with NDF (84.7 vs. 74.1 mmol/l; P = 0.095). The amount of total bacteria tended (P = 0.075) to increase with NDSF, but only in diets with 0.35 NDF. The caecal proportions of Ruminococcus albus and Fibrobacter succinogenes were not affected by type or level of fibre, but Butyrivibrio fibrisolvens decreased (P = 0.055) with the NDF proportion in LS diets. Denaturing gradient gel electrophoresis (DGGE) analysis showed that bacterial communities clustered according to each combination of NDF and NDSF, but did not greatly differ among diets (similarity indexes between 0.67 and 0.70), nor biodiversity was affected (average Shannon and richness indexes 3.50 and 33.1; P > 0.10). Archaeal population revealed changes in the amount and composition that were particularly evident in HS diets, decreasing in concentration (from 4.37 to 4.12 log10 gene copy number/g) and biodiversity (Shannon index from 3.14 to 2.52 and richness index from 23.7 to 13.9) compared to LS. The type and level of dietary fibre had a minor impact on caecal fermentation traits or caecal bacterial community. However, the increase in NDSF from 0.14 to 0.17 reduced concentration and diversity of methanogenic archaea.

  4. Microbial degradation of chelating agents used in detergents with special reference to nitrilotriacetic acid (NTA).

    PubMed

    Egli, T; Bally, M; Uetz, T

    1990-01-01

    The extensive use of phosphate-based detergents and agricultural fertilizers is one of the main causes of the world-wide eutrophication of rivers and lakes. To ameliorate such problems partial or total substitution of phosphates in laundry detergents by synthetic, non-phosphorus containing complexing agents is practiced in several countries. The physiological, biochemical and ecological aspects of the microbial degradation of the complexing agents most frequently used, such as polyphosphates, aminopolycarboxylates (especially of nitrilotriacetic acid), and phosphonates are reviewed.

  5. Pharmacology of bile acid receptors: Evolution of bile acids from simple detergents to complex signaling molecules.

    PubMed

    Copple, Bryan L; Li, Tiangang

    2016-02-01

    For many years, bile acids were thought to only function as detergents which solubilize fats and facilitate the uptake of fat-soluble vitamins in the intestine. Many early observations; however, demonstrated that bile acids regulate more complex processes, such as bile acids synthesis and immune cell function through activation of signal transduction pathways. These studies were the first to suggest that receptors may exist for bile acids. Ultimately, seminal studies by many investigators led to the discovery of several bile acid-activated receptors including the farnesoid X receptor, the vitamin D receptor, the pregnane X receptor, TGR5, α5 β1 integrin, and sphingosine-1-phosphate receptor 2. Several of these receptors are expressed outside of the gastrointestinal system, indicating that bile acids may have diverse functions throughout the body. Characterization of the functions of these receptors over the last two decades has identified many important roles for these receptors in regulation of bile acid synthesis, transport, and detoxification; regulation of glucose utilization; regulation of fatty acid synthesis and oxidation; regulation of immune cell function; regulation of energy expenditure; and regulation of neural processes such as gastric motility. Through these many functions, bile acids regulate many aspects of digestion ranging from uptake of essential vitamins to proper utilization of nutrients. Accordingly, within a short time period, bile acids moved beyond simple detergents and into the realm of complex signaling molecules. Because of the important processes that bile acids regulate through activation of receptors, drugs that target these receptors are under development for the treatment of several diseases, including cholestatic liver disease and metabolic syndrome. In this review, we will describe the various bile acid receptors, the signal transduction pathways activated by these receptors, and briefly discuss the physiological processes that

  6. Detergents and Dispersants

    NASA Astrophysics Data System (ADS)

    Seddon, E. J.; Friend, C. L.; Roski, J. P.

    Lubricant detergents are metal salts of organic surfactants giving corrosion protection, deposit prevention and other formulation performance enhancements. Overbased detergents incorporate colloidal basic inorganic components which neutralize acidic contaminants. Degrees of overbasing, size and form of component affect detergent performance. Sulphonate-, phenate- and salicylate-type detergents incorporating calcium carbonate are the most widely used. Choices of detergent type and level are highly dependent on specific applications, and combinations are needed to optimize performance and cost.

  7. Control of acid drainage from fresh coal refuse: food preservatives as economical alternatives to detergents

    SciTech Connect

    Onysko, S.J.; Erickson, P.M.; Kleinmann, R.L.P.; Hood, M.

    1984-12-01

    Water soluble detergents such as sodium lauryl sulfate (SLS), which can sorb to pyritic materials, have been successfully used by the mining industry for acid drainage prevention in coal refuse. Detergent control of acid drainage from refuse may be uneconomical, however, at sites where extensive rainfall or groundwater movement results in rapid SLS washout. In this study, the performance of two alternative acid control chemicals, sodium benzoate and potassium sorbate, was compared with the performance of SLS in pilot-scale experiments with extensively leached, fresh coal refuse. Chemical cost information is presented that indicates low benzoate and sorbate doses were more economical than comparable SLS doses under the experimental conditions of the study. The unique environmental compatibility of benzoate and sorbate, which are used in food and beverages in concentrations greater than those reported in this study for acid drainage suppression, is also discussed.

  8. Positions of polar amino acids alter interactions between transmembrane segments and detergents.

    PubMed

    Tulumello, David V; Deber, Charles M

    2011-05-17

    α-Helical transmembrane (TM) segments in membrane proteins are comprised primarily of hydrophobic amino acids that accommodate insertion from water into the nonpolar membrane bilayer. In many such segments, however, polar residues are also present for structural or functional reasons. These latter residues impair the local favorable acyl interactions required for solvation by hydrophobic media such as phospholipids in native bilayers or detergents used for in vitro characterization. Using a series of Lys-tagged designed TM-like peptides (typified by KK-YAAAIAAIAWAIAAIAAAIAA-KKK) in which single-Asn residue substitutions (from Ile or Ala) were made successively from the center of the hydrophobic region toward the C-terminus, we demonstrate that polar residues strongly alter the nature of the interaction between TM segments and the solvating detergent. Through the application of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, circular dichroism spectroscopy, and tryptophan fluorescence, we observed drastic differences in the structures of the detergent-peptide complexes that contain relatively minor sequence differences. For example, the blue shift of the Trp fluorescence (indicating local detergent solvation at this location) differs by as much as ~10 nm depending upon the position of a single Asn substitution in an otherwise identical segment. The overall results suggest that polar point mutations occurring in a biological membrane will elicit comparable effects, placing a significant refolding burden on the local protein structure and potentially leading to disease states through altered protein--lipid interactions in membrane proteins.

  9. Fatty acid profiles from the plasma membrane and detergent resistant membranes of two plant species.

    PubMed

    Carmona-Salazar, Laura; El Hafidi, Mohammed; Gutiérrez-Nájera, Nora; Noyola-Martínez, Liliana; González-Solís, Ariadna; Gavilanes-Ruíz, Marina

    2015-01-01

    It is essential to establish the composition of the plant plasma membrane in order to understand its organization and behavior under continually changing environments. Knowledge of the lipid phase, in particular the fatty acid (FA) complex repertoire, is important since FAs determine many of the physical-chemical membrane properties. FAs are constituents of the membrane glycerolipid and sphingolipid backbones and can also be linked to some sterols. In addition, FAs are components of complex lipids that can constitute membrane micro-domains, and the use of detergent-resistant membranes is a common approach to study their composition. The diversity and cellular allocation of the membrane lipids containing FAs are very diverse and the approaches to analyze them provide only general information. In this work, a detailed FA analysis was performed using highly purified plasma membranes from bean leaves and germinating maize embryos and their respective detergent-resistant membrane preparations. The analyses showed the presence of a significant amount of very long chain FAs (containing 28C, 30C and 32C), in both plasma membrane preparations from bean and maize, that have not been previously reported. Herein is demonstrated that a significant enrichment of very long chain saturated FAs and saturated FAs can occur in detergent-resistant membrane preparations, as compared to the plasma membranes from both plant species. Considering that a thorough analysis of FAs is rarely performed in purified plasma membranes and detergent-resistant membranes, this work provides qualitative and quantitative evidence on the contributions of the length and saturation of FAs to the organization of the plant plasma membrane and detergent-resistant membranes.

  10. Gravimetric determination of acid detergent fiber and lignin in feed: interlaboratory study.

    PubMed

    Möller, Jürgen

    2009-01-01

    On the basis of AOAC Official Method 973.18, a collaborative study was performed to determine fractions of acid detergent fiber (ADF) and lignin (ADL) in animal feed. The study used 6 animal feed and forage samples as blind duplicates and involved 22 participants from 7 countries. The samples analyzed covered a range from 3.5 to 70% ADF and from <1 to 20% ADL. Repeatability standard deviations ranged from 0.27 to 0.95% for ADF and from 0.08 to 0.59% for ADL. The reproducibility standard deviations ranged from 0.56 to 2.44% for ADF and from 0.52 to 2.09% for ADL. Analyzed samples comprised clover and grass silages, soy meal, cattle feed, wheat, and sawdust. The studied method has been published as the EN ISO 13906:2008 standard.

  11. Fatty acid-dependent globotriaosyl ceramide receptor function in detergent resistant model membranes.

    PubMed

    Mahfoud, Radhia; Manis, Adam; Lingwood, Clifford A

    2009-09-01

    Glycosphingolipid (GSL) fatty acid strictly regulates verotoxin 1 (VT1) and the HIV adhesin, gp120 binding to globotriaosyl ceramide within Gb(3)/cholesterol detergent resistant membrane (DRM) vesicle constructs and in Gb(3) water-air interface monolayers in a similar manner. VT2 bound Gb(3)/cholesterol vesicles irrespective of fatty acid composition, but VT1 bound neither C18 nor C20Gb(3)vesicles. C18/C20Gb(3) were dominant negative in mixed Gb(3) fatty acid isoform vesicles, but including C24:1Gb(3) gave maximal binding. VT1 bound C18Gb(3) vesicles after cholesterol removal, but C20Gb(3)vesicles required sphingomyelin in addition for binding. HIV-1gp120 also bound C16, C22, and C24, but neither C18 nor C20Gb(3) vesicles. C18 and C20Gb(3) were, in mixtures without C24:1Gb(3), dominant negative for gp120 vesicle binding. Gp120/VT1bound C18 and C24:1Gb(3) mixtures, although neither isoform bound alone. Monolayer surface pressure measurement showed VT1, but not VT2, bound Gb(3) at cellular DRM surface pressures, and confirmed loss of VT1 and gp120 (but not VT2) specific C18Gb(3) binding. We conclude fatty-acid mediated fluidity within simple model GSL/cholesterol DRM can selectively regulate GSL carbohydrate-ligand binding.

  12. Detergent poisoning

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002777.htm Detergent poisoning To use the sharing features on this page, please enable JavaScript. Detergents are powerful cleaning products that may contain strong ...

  13. Chemical and functional properties of fibre concentrates obtained from by-products of coconut kernel.

    PubMed

    Yalegama, L L W C; Nedra Karunaratne, D; Sivakanesan, Ramiah; Jayasekara, Chitrangani

    2013-11-01

    The coconut kernel residues obtained after extraction of coconut milk (MR) and virgin coconut oil (VOR) were analysed for their potential as dietary fibres. VOR was defatted and treated chemically using three solvent systems to isolate coconut cell wall polysaccharides (CCWP). Nutritional composition of VOR, MR and CCWPs indicated that crude fibre, neutral detergent fibre, acid detergent fibre and hemicelluloses contents were higher in CCWPs than in VOR and MR. MR contained a notably higher content of fat than VOR and CCWPs. The oil holding capacity, water holding capacity and swelling capacity were also higher in CCWPs than in VOR and MR. All the isolates and MR and VOR had high metal binding capacities. The CCWPs when compared with commercially available fibre isolates, indicated improved dietary fibre properties. These results show that chemical treatment of coconut kernel by-products can enhance the performance of dietary fibre to yield a better product.

  14. Chemical and functional properties of fibre concentrates obtained from by-products of coconut kernel.

    PubMed

    Yalegama, L L W C; Nedra Karunaratne, D; Sivakanesan, Ramiah; Jayasekara, Chitrangani

    2013-11-01

    The coconut kernel residues obtained after extraction of coconut milk (MR) and virgin coconut oil (VOR) were analysed for their potential as dietary fibres. VOR was defatted and treated chemically using three solvent systems to isolate coconut cell wall polysaccharides (CCWP). Nutritional composition of VOR, MR and CCWPs indicated that crude fibre, neutral detergent fibre, acid detergent fibre and hemicelluloses contents were higher in CCWPs than in VOR and MR. MR contained a notably higher content of fat than VOR and CCWPs. The oil holding capacity, water holding capacity and swelling capacity were also higher in CCWPs than in VOR and MR. All the isolates and MR and VOR had high metal binding capacities. The CCWPs when compared with commercially available fibre isolates, indicated improved dietary fibre properties. These results show that chemical treatment of coconut kernel by-products can enhance the performance of dietary fibre to yield a better product. PMID:23768337

  15. Mechanical, thermal, and biodegradable properties of polylactic acid (PLA)/coir fibre biocomposites

    NASA Astrophysics Data System (ADS)

    Dong, Y.; Ghataura, A.; Haroosh, H. J.

    2013-08-01

    Polylactic acid (PLA)/coir fibre biocomposites were fabricated using a compression moulding technique. The effects of fibre content (5-30 wt%) and fibre treatment on mechanical, thermal and biodegradable properties of biocomposites were holistically investigated via mechanical testing, scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and soil burial method to understand the applicability of manufacturing eco-efficient and sustainable "green composites".

  16. Laser micromachined and acid-etched Fabry-Perot cavities in silica fibres

    NASA Astrophysics Data System (ADS)

    Machavaram, V. R.; Tuck, C. J.; Teagle, M. C.; Badcock, R. A.; Fernando, G. F.

    2006-01-01

    This paper reports on two techniques for creating Fabry-Perot cavities in conventional single- and multi-mode optical fibres. The authors have reported previously on the design and fabrication of extrinsic fibre Fabry-Perot interferometric multi-functional sensors. Here, the authors report on two novel techniques for creating intrinsic fibre optic sensors based on the Fabry-Perot etalon. The first technique involved the use of hydrofluoric acid to preferentially etch the core of the optical fibre. This technique is simple to carry out and provides a cost-effective means for manufacturing intrinsic fibre Fabry-Perot sensors. In the second technique, a 157 nm excimer laser along with a custom-designed beam delivery system was used to ablate (micro-machine) near-paralleled walled cavities through the diameter of the optical fibre (outer diameter of 125 μm). The paper details the experimental methodology and the associated instrumentation for the two techniques. The acid etched and laser ablated cavities were characterised using a 3-D surface profiler, optical and scanning electron microscopy. The feasibility of using these cavities as intrinsic fibre Fabry-Perot strain sensors is demonstrated. This was achieved by surface-mounting the acid etched cavities on to composite tensile test specimens. The output from the optical fibre devices was compared with surface-mounted electrical resistance strain gauges.

  17. Citric acid modified kenaf core fibres for removal of methylene blue from aqueous solution.

    PubMed

    Sajab, Mohd Shaiful; Chia, Chin Hua; Zakaria, Sarani; Jani, Saad Mohd; Ayob, Mohd Khan; Chee, Kah Leong; Khiew, Poi Sim; Chiu, Wee Siong

    2011-08-01

    Chemically modified kenaf core fibres were prepared via esterification in the presence of citric acid (CA). The adsorption kinetics and isotherm studies were carried out under different conditions to examine the adsorption efficiency of CA-treated kenaf core fibres towards methylene blue (MB). The adsorption capacity of the kenaf core fibres increased significantly after the citric acid treatment. The values of the correlation coefficients indicated that the Langmuir isotherm fitted the experimental data better than the Freundlich isotherm. The maximum adsorption capacity of the CA-treated kenaf core fibres was found to be 131.6mg/g at 60°C. Kinetic models, pseudo-first-order, pseudo-second-order and intraparticle diffusion, were employed to describe the adsorption mechanism. The kinetic data were found to fit pseudo-second-order model equation as compared to pseudo-first-order model. The adsorption of MB onto the CA-treated kenaf core fibres was spontaneous and endothermic.

  18. Oleic and docosahexaenoic acid differentially phase separate from lipid raft molecules: a comparative NMR, DSC, AFM, and detergent extraction study.

    PubMed

    Shaikh, Saame Raza; Dumaual, Alfred C; Castillo, Alicia; LoCascio, Daniel; Siddiqui, Rafat A; Stillwell, William; Wassall, Stephen R

    2004-09-01

    We have previously suggested that the omega-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA) may in part function by enhancing membrane lipid phase separation into lipid rafts. Here we further tested for differences in the molecular interactions of an oleic (OA) versus DHA-containing phospholipid with sphingomyelin (SM) and cholesterol (CHOL) utilizing (2)H NMR spectroscopy, differential scanning calorimetry, atomic force microscopy, and detergent extractions in model bilayer membranes. (2)H NMR and DSC (differential scanning calorimetry) established the phase behavior of the OA-containing 1-[(2)H(31)]palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine (16:0-18:1PE-d(31))/SM (1:1) and the DHA-containing 1-[(2)H(31)]palmitoyl-2-docosahexaenoyl-sn-glycero-3-phosphoethanolamine (16:0-22:6PE-d(31))/SM (1:1) in the absence and presence of equimolar CHOL. CHOL was observed to affect the OA-containing phosphatidylethanolamine (PE) more than the DHA-containing PE, as exemplified by >2 x greater increase in order measured for the perdeuterated palmitic chain in 16:0-18:1PE-d(31)/SM (1:1) compared to 16:0-22:6PE-d(31)/SM (1:1) bilayers in the liquid crystalline phase. Atomic force microscopy (AFM) experiments showed less lateral phase separation between 16:0-18:1PE-rich and SM/CHOL-rich raft domains in 16:0-18:1PE/SM/CHOL (1:1:1) bilayers than was observed when 16:0-22:6PE replaced 16:0-18:1PE. Differences in the molecular interaction of 16:0-18:1PE and 16:0-22:6PE with SM/CHOL were also found using biochemical detergent extractions. In the presence of equimolar SM/CHOL, 16:0-18:1PE showed decreased solubilization in comparison to 16:0-22:6PE, indicating greater phase separation with the DHA-PE. Detergent experiments were also conducted with cardiomyocytes fed radiolabeled OA or DHA. Although both OA and DHA were found to be largely detergent solubilized, the amount of OA that was found to be associated with raft-rich detergent-resistant membranes exceeded DHA by

  19. Hydrocarbon fuel detergent

    SciTech Connect

    Meyer, G.R.; Lyons, W.R.

    1990-01-23

    This patent describes a hydrocarbon fuel composition comprising: a hydrocarbon fuel; and a detergent amount of a detergent comprising an alkenylsuccinimide prepared by reacting an alkenylsuccinic acid or anhydride with a mixture of amines, wherein at least 90 weight percent of the alkenyl substituent is derived from an olefin having a carbon chain of from 10 to 30 carbons or mixtures thereof, and wherein the alkenylsuccinic acid or anhydride is reacted with the mixture of amines at a mole ratio of 0.8 to 1.5 moles of the amines per mole of the alkenylsuccinic acid or anhydride.

  20. Cationic DOPC-Detergent Conjugates for Safe and Efficient in Vitro and in Vivo Nucleic Acid Delivery.

    PubMed

    Pierrat, Philippe; Casset, Anne; Didier, Pascal; Kereselidze, Dimitri; Lux, Marie; Pons, Françoise; Lebeau, Luc

    2016-09-15

    The ability of a nonviral nucleic acid carrier to deliver its cargo to cells with low associated toxicity is a critical issue for clinical applications of gene therapy. We describe biodegradable cationic DOPC-C12 E4 conjugates in which transfection efficiency is based on a Trojan horse strategy. In situ production of the detergent compound C12 E4 through conjugate hydrolysis within the acidic endosome compartment was expected to promote endosome membrane destabilization and subsequent release of the lipoplexes into cytosol. The transfection efficiency of the conjugates has been assessed in vitro, and associated cytotoxicity was determined. Cellular uptake and intracellular distribution of the lipoplexes have been investigated. The results show that direct conjugation of DOPC with C12 E4 produces a versatile carrier that can deliver both DNA and siRNA to cells in vitro with high efficiency and low cytotoxicity. SAR studies suggest that this compound might represent a reasonable compromise between the membrane activity of the released detergent and susceptibility of the conjugate to degradation enzymes in vitro. Although biodegradability of the conjugates had low impact on carrier efficiency in vitro, it proved critical in vivo. Significant improvement of transgene expression was obtained in the mouse lung tuning biodegradability of the carrier. Importantly, this also allowed reduction of the inflammatory response that invariably characterizes cationic-lipid-mediated gene transfer in animals. PMID:27380144

  1. Cationic DOPC-Detergent Conjugates for Safe and Efficient in Vitro and in Vivo Nucleic Acid Delivery.

    PubMed

    Pierrat, Philippe; Casset, Anne; Didier, Pascal; Kereselidze, Dimitri; Lux, Marie; Pons, Françoise; Lebeau, Luc

    2016-09-15

    The ability of a nonviral nucleic acid carrier to deliver its cargo to cells with low associated toxicity is a critical issue for clinical applications of gene therapy. We describe biodegradable cationic DOPC-C12 E4 conjugates in which transfection efficiency is based on a Trojan horse strategy. In situ production of the detergent compound C12 E4 through conjugate hydrolysis within the acidic endosome compartment was expected to promote endosome membrane destabilization and subsequent release of the lipoplexes into cytosol. The transfection efficiency of the conjugates has been assessed in vitro, and associated cytotoxicity was determined. Cellular uptake and intracellular distribution of the lipoplexes have been investigated. The results show that direct conjugation of DOPC with C12 E4 produces a versatile carrier that can deliver both DNA and siRNA to cells in vitro with high efficiency and low cytotoxicity. SAR studies suggest that this compound might represent a reasonable compromise between the membrane activity of the released detergent and susceptibility of the conjugate to degradation enzymes in vitro. Although biodegradability of the conjugates had low impact on carrier efficiency in vitro, it proved critical in vivo. Significant improvement of transgene expression was obtained in the mouse lung tuning biodegradability of the carrier. Importantly, this also allowed reduction of the inflammatory response that invariably characterizes cationic-lipid-mediated gene transfer in animals.

  2. A knockout mutation in the lignin biosynthesis gene CCR1 explains a major QTL for acid detergent lignin content in Brassica napus seeds.

    PubMed

    Liu, Liezhao; Stein, Anna; Wittkop, Benjamin; Sarvari, Pouya; Li, Jiana; Yan, Xingying; Dreyer, Felix; Frauen, Martin; Friedt, Wolfgang; Snowdon, Rod J

    2012-05-01

    Seed coat phenolic compounds represent important antinutritive fibre components that cause a considerable reduction in value of seed meals from oilseed rape (Brassica napus). The nutritionally most important fibre compound is acid detergent lignin (ADL), to which a significant contribution is made by phenylpropanoid-derived lignin precursors. In this study, we used bulked-segregant analysis in a population of recombinant inbred lines (RILs) from a cross of the Chinese oilseed rape lines GH06 (yellow seed, low ADL) and P174 (black seed, high ADL) to identify markers with tight linkage to a major quantitative trait locus (QTL) for seed ADL content. Fine mapping of the QTL was performed in a backcross population comprising 872 BC(1)F(2) plants from a cross of an F(7) RIL from the above-mentioned population, which was heterozygous for this major QTL and P174. A 3:1 phenotypic segregation for seed ADL content indicated that a single, dominant, major locus causes a substantial reduction in ADL. This locus was successively narrowed to 0.75 cM using in silico markers derived from a homologous Brassica rapa sequence contig spanning the QTL. Subsequently, we located a B. rapa orthologue of the key lignin biosynthesis gene CINNAMOYL CO-A REDUCTASE 1 (CCR1) only 600 kbp (0.75 cM) upstream of the nearest linked marker. Sequencing of PCR amplicons, covering the full-length coding sequences of Bna.CCR1 homologues, revealed a locus in P174 whose sequence corresponds to the Brassica oleracea wild-type allele from chromosome C8. In GH06, however, this allele is replaced by a homologue derived from chromosome A9 that contains a loss-of-function frameshift mutation in exon 1. Genetic and physical map data infer that this loss-of-function allele has replaced a functional Bna.CCR1 locus on chromosome C8 in GH06 by homoeologous non-reciprocal translocation.

  3. Acid hydrolysis of cellulosic fibres: Comparison of bleached kraft pulp, dissolving pulps and cotton textile cellulose.

    PubMed

    Palme, Anna; Theliander, Hans; Brelid, Harald

    2016-01-20

    The behaviour of different cellulosic fibres during acid hydrolysis has been investigated and the levelling-off degree of polymerisation (LODP) has been determined. The study included a bleached kraft pulp (both never-dried and once-dried) and two dissolving pulps (once-dried). Additionally, cotton cellulose from new cotton sheets and sheets discarded after long-time use was studied. Experimental results from the investigation, together with results found in literature, imply that ultrastructural differences between different fibres affect their susceptibility towards acid hydrolysis. Drying of a bleached kraft pulp was found to enhance the rate of acid hydrolysis and also result in a decrease in LODP. This implies that the susceptibility of cellulosic fibres towards acid hydrolysis is affected by drying-induced stresses in the cellulose chains. In cotton cellulose, it was found that use and laundering gave a substantial loss in the degree of polymerisation (DP), but that the LODP was only marginally affected.

  4. Contents of total fat, fatty acids, starch, sugars and dietary fibre in Swedish market basket diets.

    PubMed

    Becker, W; Eriksson, A; Haglund, M; Wretling, S

    2015-05-14

    The typical dietary supply of total fat, fatty acids, starch, sugars, polyols and dietary fibre in Sweden was assessed from analyses of market baskets (MB) purchased in 2005 and 2010. MB were based on food balance sheets, with each basket comprising about 130 foods, which represented more than 90% of annual dietary supply. Foods were divided into ten to twelve categories. In 2010, total fat contributed 34% of energy (E%), SFA 14.3 E%, MUFA 12.8 E%, PUFA 4.6 E%, n-6 fatty acids 3.6 E%, n-3 fatty acids 1.0 E% and trans-fatty acids (TFA) 0.5 E%. Glycaemic carbohydrates contributed 47 E%, monosaccharides 9 E%, sucrose 11 E%, disaccharides 15 E% and total sugars 24 E%. Added sugars contributed about 15 E%. Dietary fibre content was about 1.7 g/MJ in the 2010 MB. Compared with the 2005 MB, the dietary supply of TFA and dietary fibre was lower, otherwise differences were small. The present MB survey shows that the content of SFA and added sugars was higher than the current Nordic Nutrition Recommendations, while the content of PUFA and especially dietary fibre was lower. TFA levels decreased and dietary supply was well below the recommendations of the WHO. These results emphasise a focus on quality and food sources of fat and carbohydrates, limiting foods rich in SFA and added sugars and replacing them with foods rich in dietary fibre and cis-unsaturated fatty acids.

  5. Experimenting with Detergents

    ERIC Educational Resources Information Center

    Mitchell, Gail; Phillips, Donald B.

    1977-01-01

    Lists materials and procedures for experimenting with detergents. Included are methods for determination of the densities of dry detergents, ph values of detergent solutions, and a discussion of the ability of detergents to remove iodine stains from cloth. (CS)

  6. Caffeic acid and glycerol are constituents of the suberin layers in green cotton fibres.

    PubMed

    Schmutz, A; Jenny, T; Amrhein, N; Ryser, U

    1993-03-01

    The fibres of the green-lint mutant (Lg) of cotton (Gossypium hirsutum L.) are suberized and contain a large proportion of wax. The unidentified components of the wax were separated into a colourless fluorescent fraction and a yellow pigmented fraction. Using ultraviolet spectroscopy and nuclear-magneticresonance ((1)H-NMR) spectroscopy, esterified trans-caffeic acid was identified as the only phenolic component in the colourless fraction. This fraction was further purified and was shown to contain caffeic acid esterified to fatty acids (mainly ω-hydroxy fatty acids), and glycerol in molar ratios of 4∶5∶5. When 2-aminoindan-2-phosphonic acid (AIP), an inhibitor of phenylalanine ammonia-lyase (EC 4. 3. 1. 5.) was added to ovules cultured in vitro, at the beginning of secondary wall formation, the fibres remained white and the colourless caffeic-acid derivative and the yellow compounds could no longer be detected by ultraviolet spectroscopy. Fibres grown in the presence of AIP were also examined in the electron microscope. Secondary cell walls were present in the treated fibres, but the electron-opaque suberin layers were replaced by apparently empty spaces. This result indicates that cinnamic-acid derivatives are covalently linked to suberin and have a structural role within the polymer or are involved in anchoring the polymer to the cellulosic secondary wall. Purified cell walls of green cotton fibres contained about 1% (of the dry weight) of bound glycerol, 0.9% of the glycerol being extractable with the wax fraction and 0.1% remaining in the cell-wall residue. The corresponding values for white fibres were 0.03% (total), 0.02% (wax), and 0.01% (cell-wall residue). Fibres synthesizing their secondary walls in the presence of AIP contained about normal amounts of bound glycerol in the wax fraction, but glycerol accumulation in the cell-wall residue was inhibited by about 95%. These observations indicate that glycerol is an important constituent of cotton-fibre

  7. Substitution of crude cell wall for neutral detergent fibre in the equations of the Cornell Net Carbohydrate and Protein System that predict carbohydrate fractions: application to sunflower ( Helianthus annuus L.).

    PubMed

    Queiroz, M A A; Fukushima, R S; Gomide, C A; Braga, M R

    2008-07-01

    Prediction of carbohydrate fractions using equations from the Cornell Net Carbohydrate and Protein System (CNCPS) is a valuable tool to assess the nutritional value of forages. In this paper, these carbohydrate fractions were predicted using data from three sunflower (Helianthus annuus L.) cultivars, fresh or as silage. The CNCPS equations for fractions B2 and C include measurement of ash and protein-free neutral detergent fibre (NDF) as one of their components. However, NDF lacks pectin and other non-starch polysaccharides that are found in the cell wall (CW) matrix, so this work compared the use of a crude CW preparation instead of NDF in the CNCPS equations. There were no differences in the estimates of fractions B1 and C when CW replaced NDF; however, there were differences in fractions A and B2. Some of the CNCPS equations could be simplified when using CW instead of NDF. Notably, lignin could be expressed as a proportion of DM, rather than on the basis of ash and protein-free NDF, when predicting CNCPS fraction C. The CNCPS fraction B1 (starch + pectin) values were lower than pectin determined through wet chemistry. This finding, along with the results obtained by the substitution of CW for NDF in the CNCPS equations, suggests that pectin was not part of fraction B1 but present in fraction A. We suggest that pectin and other non-starch polysaccharides that are dissolved by the neutral detergent solution be allocated to a specific fraction (B2) and that another fraction (B3) be adopted for the digestible cell wall carbohydrates.

  8. [Analysis of alkaline CuO degradation products of acid detergent fiber from tobacco leaves by using liquid chromatography].

    PubMed

    Hao, Weiqiang; Wang, Leijun; Wu, Shun; Yue, Bangyi; Chen, Qiang; Zhang, Peipei

    2015-07-01

    The acid detergent fiber (ADF) from tobacco leaves was obtained by treating the sample with petroleum ether-ethanol (6:4, v/v), 30 g/L sodium dodecylsulfate and 0.5 mol/L sulphuric acid containing 20 g/L hexadecyl trimethyl ammonium bromide successively. The ADF was degraded by the alkaline CuO oxidation procedure. In this work, six samples of ADF degradation products from tobacco leaves were prepared. The samples were analyzed by using gradient liquid chromatography (LC) where an Ultimate XB C18 column was used as stationary phase, with a mixture of methanol and water as mobile phase, at a column temperature of 35 °C and a flow rate of 0.8 mL/min. Dual wavelengths of 280 nm and 320 nm were chosen for the detection. It was found that there were four characteristic peaks for the ADF degradation products. By taking these peaks as research object, the optimum time for the degradation was found to be 5 h and the sample solution could be kept stable within 7 days. The established method may provide a new approach for the studies of the differences between lignin composition in different tobacco leaves and the relationship between lignin content and the smoking quality of tobacco leaves. PMID:26672209

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

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

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

  10. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.).

    PubMed

    Wang, Jia; Jian, Hongju; Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS.

  11. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.).

    PubMed

    Wang, Jia; Jian, Hongju; Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS. PMID:26673885

  12. Genome-Wide Analysis of Seed Acid Detergent Lignin (ADL) and Hull Content in Rapeseed (Brassica napus L.)

    PubMed Central

    Wei, Lijuan; Qu, Cunmin; Xu, Xinfu; Lu, Kun; Qian, Wei; Li, Jiana; Li, Maoteng; Liu, Liezhao

    2015-01-01

    A stable yellow-seeded variety is the breeding goal for obtaining the ideal rapeseed (Brassica napus L.) plant, and the amount of acid detergent lignin (ADL) in the seeds and the hull content (HC) are often used as yellow-seeded rapeseed screening indices. In this study, a genome-wide association analysis of 520 accessions was performed using the Q + K model with a total of 31,839 single-nucleotide polymorphism (SNP) sites. As a result, three significant associations on the B. napus chromosomes A05, A09, and C05 were detected for seed ADL content. The peak SNPs were within 9.27, 14.22, and 20.86 kb of the key genes BnaA.PAL4, BnaA.CAD2/BnaA.CAD3, and BnaC.CCR1, respectively. Further analyses were performed on the major locus of A05, which was also detected in the seed HC examination. A comparison of our genome-wide association study (GWAS) results and previous linkage mappings revealed a common chromosomal region on A09, which indicates that GWAS can be used as a powerful complementary strategy for dissecting complex traits in B. napus. Genomic selection (GS) utilizing the significant SNP markers based on the GWAS results exhibited increased predictive ability, indicating that the predictive ability of a given model can be substantially improved by using GWAS and GS. PMID:26673885

  13. Structural changes of Salix miyabeana cellulose fibres during dilute-acid steam explosion: impact of reaction temperature and retention time.

    PubMed

    Diop, Chérif Ibrahima Khalil; Lavoie, Jean-Michel; Huneault, Michel A

    2015-03-30

    Dilute-acid steam explosion of Salix miyabeana has been carried out to understand the effect of processing conditions, expressed through a severity factors (SFT), on the changes in cellulose fibre structures in a perspective of using these in polymer composites. This thermo-chemico-mechanical extraction leads to the isolation of cellulose fibres as observed by SEM images. Fibre length as well as length to diameter aspect ratios decreased with the severity of the treatment. Likewise, fibre whiteness diminished with an increasing severity factor, which could be a tangible effect of physical degradation. Variations in crystallinity seemed to be dependent upon the reaction temperature, generally decreasing with regards to retention time. Above a severity threshold, a structural disorganization was observed. Overall, dilute-acid steam explosion was shown to be a valuable cellulose extraction process that can provide a variety of fibre structures.

  14. Exploring Detergent Pollution

    ERIC Educational Resources Information Center

    Rillo, Thomas J.

    1975-01-01

    Reviews the ecological dangers of certain types of detergents, and the action taken by government agencies and detergent manufacturers to alleviate the problem. Describes classroom activities and instructional procedures designed to illustrate detergent characteristics and the effects of detergent pollution. (MLH)

  15. Acid detergent lignin, lodging resistance index, and expression of the caffeic acid O-methyltransferase gene in brown midrib-12 sudangrass

    PubMed Central

    Li, Yuan; Liu, Guibo; Li, Jun; You, Yongliang; Zhao, Haiming; Liang, Huan; Mao, Peisheng

    2015-01-01

    Understanding the relationship between acid detergent lignin (ADL) and lodging resistance index (LRI) is essential for breeding new varieties of brown midrib (bmr) sudangrass (Sorghum sudanense (Piper) Stapf.). In this study, bmr-12 near isogenic lines and their wild-types obtained by back cross breeding were used to compare relevant forage yield and quality traits, and to analyze expression of the caffeic acid O-methyltransferase (COMT) gene using quantitative real time-PCR. The research showed that the mean ADL content of bmr-12 mutants (20.94 g kg−1) was significantly (P < 0.05) lower than measured in N-12 lines (43.45 g kg−1), whereas the LRI of bmr-12 mutants (0.29) was significantly (P < 0.05) higher than in N-12 lines (0.22). There was no significant correlation between the two indexes in bmr-12 materials (r = −0.44, P > 0.05). Sequence comparison of the COMT gene revealed two point mutations present in bmr-12 but not in the wild-type, the second mutation changed amino acid 129 of the protein from Gln (CAG) to a stop codon (UAG). The relative expression level of COMT gene was significantly reduced, which likely led to the decreased ADL content observed in the bmr-12 mutant. PMID:26366111

  16. Surface Resistance of Jute Fibre/Polylactic Acid Biocomposite to Wet Heat

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Jute fibre/polylactic acid (PLA) composite is of special interest because both resin and reinforcement come from renewable resources. Thus, it could be a more eco-friendly alternative to glass fibre composite [1] and to conventional wood-based panels made with phenol-formaldehyde resin which present many drawbacks for the workers and the environment [2]. Yet the water affinity of the natural fibres, the susceptibility of PLA towards hydrolysis and the low glass transition of the PLA raise a question about the surface resistance of such composites to wet heat in service condition for a furniture application [3]. In this work, the surface resistance of PLA/jute composite alone and with two different varnishes are investigated in regard to an interior application following the standard test method in accordance to BS EN 18721:2009: "Furniture: assessment of surface resistance to wet heat". It is compared to two common wood based panels, plywood and hardboard. After test, the composite material surface is found to be more affected than plywood and hardboard, but it becomes resistant to wet heat when a layer of biosourced varnish or petrol-based polyurethane varnish are applied on the surface.

  17. Convenient and rapid removal of detergent from glycolipids in detergent-resistant membrane microdomains.

    PubMed

    Suzuki, Yusuke; Kabayama, Kazuya

    2012-03-01

    Although detergents are often essential in protocols, they are usually incompatible with further biochemical analysis. There are several methods for detergent removal, but the procedures are complicated or suffer from sample loss. Here, we describe a convenient and rapid method for detergent removal from sialic acid-containing glycosphingolipids (gangliosides) and neutral glycolipids in detergent-resistant membrane (DRM) microdomain. It is based on selective detergent extraction, in which the sample is dried on a glass tube, followed by washing with organic solvent. We investigated 18 organic solvents and used high performance thin-layer chromatography (HPTLC) and matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS) to confirm that dichloroethane (DCE) was the most suitable solvent and completely removed the nonionic detergent Triton X-100. Furthermore, DCE extraction effectively removed interference caused by other nonionic, zwitterionic, or ionic detergents in MALDI-QIT-TOF MS analysis.

  18. Dietary fibre, mineral, vitamin, amino acid and fatty acid content of seagrasses from Tuticorin Bay, southeast coast of India.

    PubMed

    Jeevitha, M; Athiperumalsami, T; Kumar, Venkataraman

    2013-06-01

    The amount of dietary fibre, mineral and vitamin were determined in root, rhizome and leaf of four commonly-available seagrasses, Cymodocea serrulata, Syringodium isoetifolium, Halophila ovalis and Halodule pinifolia at a station off Hare Island, Tuticorin (8°45' N, 78°12' E) in the Gulf of Mannar Biosphere region during premonsoon (July-September), monsoon (October-December) and postmonsoon (January-March) seasons of 2010-2011 and 2011-2012 study period. The entire tissues from each seagrass were subjected to HPLC and GC analysis for determining amino acid and fatty acid profiles respectively. The rhizomes of H. ovalis possessed highest amount of dietary fibre during monsoon. C. serrulata showed maximum content of K in rhizome during monsoon. Highest amount of Ca and Mg was recorded in the rhizome and leaf of H. pinifolia in postmonsoon. S. isoetifolium exhibited peak value for Na in its rhizome during monsoon. Highest amounts of Vitamin A, C and E were registered in the rhizome/root of Cymodocea during postmonsoon. Vitamin B3 was maximum in the root of Syringodium in monsoon. Eighteen of the twenty amino acids detected in seagrasses were found to the maximum level in Halodule. Syriingodium showed the highest amount of six of the seven fatty acids recorded. PMID:23510655

  19. Dietary fibre, mineral, vitamin, amino acid and fatty acid content of seagrasses from Tuticorin Bay, southeast coast of India.

    PubMed

    Jeevitha, M; Athiperumalsami, T; Kumar, Venkataraman

    2013-06-01

    The amount of dietary fibre, mineral and vitamin were determined in root, rhizome and leaf of four commonly-available seagrasses, Cymodocea serrulata, Syringodium isoetifolium, Halophila ovalis and Halodule pinifolia at a station off Hare Island, Tuticorin (8°45' N, 78°12' E) in the Gulf of Mannar Biosphere region during premonsoon (July-September), monsoon (October-December) and postmonsoon (January-March) seasons of 2010-2011 and 2011-2012 study period. The entire tissues from each seagrass were subjected to HPLC and GC analysis for determining amino acid and fatty acid profiles respectively. The rhizomes of H. ovalis possessed highest amount of dietary fibre during monsoon. C. serrulata showed maximum content of K in rhizome during monsoon. Highest amount of Ca and Mg was recorded in the rhizome and leaf of H. pinifolia in postmonsoon. S. isoetifolium exhibited peak value for Na in its rhizome during monsoon. Highest amounts of Vitamin A, C and E were registered in the rhizome/root of Cymodocea during postmonsoon. Vitamin B3 was maximum in the root of Syringodium in monsoon. Eighteen of the twenty amino acids detected in seagrasses were found to the maximum level in Halodule. Syriingodium showed the highest amount of six of the seven fatty acids recorded.

  20. Preparation of Porous Core-Shell Poly L-Lactic Acid/Polyethylene Glycol Superfine Fibres Containing Drug.

    PubMed

    Yang, Wenjing; He, Nongyue; Fu, Juan; Li, Zhiyang; Ji, Xuyuan

    2015-12-01

    In this paper, poly L-lactic acid (PLLA) blended with polyethylene glycol (PEG) was dissolved in methylene dichloride solution as the shell solution, and rapamycin (RAPA), was encapsulated inside the core of PLLA micro/nano fibres as a model drug. The effects of the blending ratio of PLLA to PEG, the concentration of the electrospinning solution, the voltage, the flow rate, and the encapsulation efficiency were studied. Uniform and porous RAPA-Loading PLLA fibres were obtained when the ratio of PLLA to PEG was 7/3, the concentration of PLLA was 3%, the applied voltage was 7.5 kV, and the pump speed was V(core) = 0.1 mL/h, V(shell) = 1 mL/h, repectively. The average diameter of PLLA fibres increased with the gradual increase in PLLA concentration. FTIR results showed that RAPA was successfully encapsulated into the core-co-shell PLLA fibres. Meanwhile, the RAPA-loading of coaxial electrospun PLLA fibres was significantly higher than that of the blending electrospun fibres. It was also found that the porous core-shell PLLA/PEG blending superfine fibres could regulate the appearance of pore on the surface of superfine fibres by adjusting the electrospinning parameters. The porous PLLA/PEG blending fibres can be used as drug carriers and, to improve the single way of drug release depending on the degradation of shell material to meet different need. It will be a remarkable breakthrough in the area for sustained and controlled release drug delivery system. PMID:26682434

  1. Preparation of Porous Core-Shell Poly L-Lactic Acid/Polyethylene Glycol Superfine Fibres Containing Drug.

    PubMed

    Yang, Wenjing; He, Nongyue; Fu, Juan; Li, Zhiyang; Ji, Xuyuan

    2015-12-01

    In this paper, poly L-lactic acid (PLLA) blended with polyethylene glycol (PEG) was dissolved in methylene dichloride solution as the shell solution, and rapamycin (RAPA), was encapsulated inside the core of PLLA micro/nano fibres as a model drug. The effects of the blending ratio of PLLA to PEG, the concentration of the electrospinning solution, the voltage, the flow rate, and the encapsulation efficiency were studied. Uniform and porous RAPA-Loading PLLA fibres were obtained when the ratio of PLLA to PEG was 7/3, the concentration of PLLA was 3%, the applied voltage was 7.5 kV, and the pump speed was V(core) = 0.1 mL/h, V(shell) = 1 mL/h, repectively. The average diameter of PLLA fibres increased with the gradual increase in PLLA concentration. FTIR results showed that RAPA was successfully encapsulated into the core-co-shell PLLA fibres. Meanwhile, the RAPA-loading of coaxial electrospun PLLA fibres was significantly higher than that of the blending electrospun fibres. It was also found that the porous core-shell PLLA/PEG blending superfine fibres could regulate the appearance of pore on the surface of superfine fibres by adjusting the electrospinning parameters. The porous PLLA/PEG blending fibres can be used as drug carriers and, to improve the single way of drug release depending on the degradation of shell material to meet different need. It will be a remarkable breakthrough in the area for sustained and controlled release drug delivery system.

  2. Effect of autoclaving on dietary fibre content of beet root (Beta vulgaris). Evaluation by different methods.

    PubMed

    Villanueva, M J; Rodríguez, M D; Redondo, A; Saco, M D

    1996-10-01

    Modifications of dietary fibre in beet root during autoclaving have been evaluated by different methods: acid detergent (raw = 1.45%; processed = 1.17%) and neutral detergent (raw = 2.30%; processed = 2.00%), the enzymatic-gravimetric method of Asp (raw = 3.35%; processed = 3.34%), HPLC (raw = 1.42%; processed = 1.60%) and 3,5-dimethylphenol (raw = 0.36; processed = 0.28%). The correlation between different methodologies was studied. Autoclaving was carried out at 121 degrees C under pressure for 15 min. Variance analysis indicated that quantitative variations originating in the thermic treatment were not statistically significant (P > 0.05).

  3. Cytocompatibility and Mechanical Properties of Short Phosphate Glass Fibre Reinforced Polylactic Acid (PLA) Composites: Effect of Coupling Agent Mediated Interface

    PubMed Central

    Hasan, Muhammad Sami; Ahmed, Ifty; Parsons, Andrew; Walker, Gavin; Scotchford, Colin

    2012-01-01

    In this study three chemical agents Amino-propyl-triethoxy-silane (APS), sorbitol ended PLA oligomer (SPLA) and Hexamethylene diisocyanate (HDI) were identified to be used as coupling agents to react with the phosphate glass fibre (PGF) reinforcement and the polylactic acid (PLA) polymer matrix of the composite. Composites were prepared with short chopped strand fibres (l = 20 mm, ϕ = 20 µm) in a random arrangement within PLA matrix. Improved, initial composite flexural strength (~20 MPa) was observed for APS treated fibres, which was suggested to be due to enhanced bonding between the fibres and polymer matrix. Both APS and HDI treated fibres were suggested to be covalently linked with the PLA matrix. The hydrophobicity induced by these coupling agents (HDI, APS) helped to resist hydrolysis of the interface and thus retained their mechanical properties for an extended period of time as compared to non-treated control. Approximately 70% of initial strength and 65% of initial modulus was retained by HDI treated fibre composites in contrast to the control, where only ~50% of strength and modulus was retained after 28 days of immersion in PBS at 37 °C. All coupling agent treated and control composites demonstrated good cytocompatibility which was comparable to the tissue culture polystyrene (TCP) control, supporting the use of these materials as coupling agent’s within medical implant devices. PMID:24955744

  4. Results of fibre and toner flotation depending on oleic acid dosage.

    PubMed

    Trumic, Maja S; Trumic, Milan Z; Vujic, Bogdana; Andric, Ljubisa; Bogdanovic, Grozdanka

    2016-09-01

    The literature was reviewed with respect to deinking flotation methods with toner samples, specifically emphasizing the speciation of copy machine and laser printing, which produce an increasing quantity of paper that is difficult to recycle. Speciation here refers to the physical-chemical characteristics of the toner, which change because of the polymerization (fusion) and oxidation process, due to exposure to heat, light and oxygen (air) during the printing process. To simulate the deinking flotation, after the ideal disintegration process, samples of toner were prepared in order to provide free toner particles. Synthetic toner has iron content and the same physical-chemical features as free disintegrated printed toner particles.We report the toner (I) and fibre (Y) recovery and the brightness (B) of laboratory filter pads formed of deinked product as deinking efficiencies. The application of oleic acid as the collector in the flotation stage gives a better flotation recovery in alkaline than in acidic conditions. The highest brightness (BF = 93.66%) and flotation recoveries (I = 90, Y = 92.82%) were achieved during testing at an oleic acid concentration of 3.38·10(-6) mol l(-1), which is the lowest dose used. This makes the use of oleic acid economical and environmentally friendly. PMID:27354017

  5. Laundry detergents: an overview.

    PubMed

    Bajpai, Divya; Tyagi, V K

    2007-01-01

    Nowadays laundry detergents are becoming increasingly popular as they can be metered automatically into the washing machine, impart softness, antistaticness, resiliency to fabrics, mild to eyes and skins and shows good dispersibility in water. Because it is consumed when it is used, the sale of laundry detergent is a rather large business. There are many different kinds or brands of laundry detergent sold, many of them claiming some special qualities as selling points. A Laundry detergent composition is a formulated mixture of raw materials that can be classified into different types based on their properties and function in the final product. The different classes of raw materials are surfactants, builders, bleaching agents, enzymes, and minors which remove dirt, stain, and soil from surfaces or textiles gave them pleasant feel and odour. The physico-chemical properties of surfactants make them suitable for laundry purposes. Laundry detergent has traditionally been a powdered or granular solid, but the use of liquid laundry detergents has gradually increased over the years, and these days use of liquid detergent equals or even exceeds use of solid detergent. This review paper describes the history, composition, types, mechanism, consumption, environmental effects and consumption of laundry detergents.

  6. Effect of detergents on streptolysin S precursor.

    PubMed

    Calandra, G B

    1980-08-01

    Group A streptococci which produce streptolysin S contain a cellular precursor to streptolysin S in the membranes and cytoplasm which is activatable by blending in a Vortex mixer with glass beads and ribonucleic acid (RNA)-core (RNA preparation from yeast). Although no activation of precursor occurred when it was mixed with detergents, it was activated when blended with glass beads and detergents such as Tergitol NP-40 and Brij 35. Maximum activation of precursor was achieved in 1 to 2% detergent, in pH 6.5 buffer, and after 8 min of blending. Detergents Tween 20, 40, 60, and 80, Brij 56, and Lubrol WX also activated precursor, but, of all the hemolysin preparations, those with Tween 40 or 60 or Lubrol WX were the most stable. The addition of RNA-core during or after blending of precursor with detergents enhanced the titer and stability of the hemolysin. This was due in part to the association of the hemolytic moiety with RNA-core. Activation of precursor in the membrane was better with a detergent, whereas that in the cytoplasm was better with RNA-core. Therefore, precursor from two different cellular locations can be differentiated by the effects of RNA-core and detergents on precursor titer.

  7. Detergent toxicity survey.

    PubMed

    Seabaugh, V M; Bayard, S P; Osterberg, R E; Porter, W K; McCaulley, D F; Hoheisel, C A; Hehir, R M; Bierbower, G W

    1977-04-01

    A survey of over 249 detergent products involving biological testing, chemical analyses, and product label reviews has been conducted from 1971-1976 for determining compliance with the Federal Hazardous Substances Act. Test results for 145 detergent products having both chemical and biological data were examined. All of the tested detergents were rabbit eye irritants. Forty-seven per cent were also either rabbit primary skin irritants or corrosives. Eighty-one per cent were either rabbit esophageal test irritants or corrosives, and 80 per cent had rat oral toxicities 5g/kg or less.

  8. Dietary fibre components and pectin chemical features of peels during ripening in banana and plantain varieties.

    PubMed

    Happi Emaga, Thomas; Robert, Christelle; Ronkart, Sébastien N; Wathelet, Bernard; Paquot, Michel

    2008-07-01

    The effects of the ripeness stage of banana (Musa AAA) and plantain (Musa AAB) peels on neutral detergent fibre, acid detergent fibre, cellulose, hemicelluloses, lignin, pectin contents, and pectin chemical features were studied. Plantain peels contained a higher amount of lignin but had a lower hemicellulose content than banana peels. A sequential extraction of pectins showed that acid extraction was the most efficient to isolate banana peel pectins, whereas an ammonium oxalate extraction was more appropriate for plantain peels. In all the stages of maturation, the pectin content in banana peels was higher compared to plantain peels. Moreover, the galacturonic acid and methoxy group contents in banana peels were higher than in plantain peels. The average molecular weights of the extracted pectins were in the range of 132.6-573.8 kDa and were not dependant on peel variety, while the stage of maturation did not affect the dietary fibre yields and the composition in pectic polysaccharides in a consistent manner. This study has showed that banana peels are a potential source of dietary fibres and pectins. PMID:17931857

  9. Dietary fibre components and pectin chemical features of peels during ripening in banana and plantain varieties.

    PubMed

    Happi Emaga, Thomas; Robert, Christelle; Ronkart, Sébastien N; Wathelet, Bernard; Paquot, Michel

    2008-07-01

    The effects of the ripeness stage of banana (Musa AAA) and plantain (Musa AAB) peels on neutral detergent fibre, acid detergent fibre, cellulose, hemicelluloses, lignin, pectin contents, and pectin chemical features were studied. Plantain peels contained a higher amount of lignin but had a lower hemicellulose content than banana peels. A sequential extraction of pectins showed that acid extraction was the most efficient to isolate banana peel pectins, whereas an ammonium oxalate extraction was more appropriate for plantain peels. In all the stages of maturation, the pectin content in banana peels was higher compared to plantain peels. Moreover, the galacturonic acid and methoxy group contents in banana peels were higher than in plantain peels. The average molecular weights of the extracted pectins were in the range of 132.6-573.8 kDa and were not dependant on peel variety, while the stage of maturation did not affect the dietary fibre yields and the composition in pectic polysaccharides in a consistent manner. This study has showed that banana peels are a potential source of dietary fibres and pectins.

  10. Advances in protease engineering for laundry detergents.

    PubMed

    Vojcic, Ljubica; Pitzler, Christian; Körfer, Georgette; Jakob, Felix; Ronny Martinez; Maurer, Karl-Heinz; Schwaneberg, Ulrich

    2015-12-25

    Proteases are essential ingredients in modern laundry detergents. Over the past 30 years, subtilisin proteases employed in the laundry detergent industry have been engineered by directed evolution and rational design to tailor their properties towards industrial demands. This comprehensive review discusses recent success stories in subtilisin protease engineering. Advances in protease engineering for laundry detergents comprise simultaneous improvement of thermal resistance and activity at low temperatures, a rational strategy to modulate pH profiles, and a general hypothesis for how to increase promiscuous activity towards the production of peroxycarboxylic acids as mild bleaching agents. The three protease engineering campaigns presented provide in-depth analysis of protease properties and have identified principles that can be applied to improve or generate enzyme variants for industrial applications beyond laundry detergents.

  11. Structure of a protein-detergent complex: the balance between detergent cohesion and binding.

    PubMed

    Khao, Jonathan; Arce-Lopera, Jaime; Sturgis, James N; Duneau, Jean-Pierre

    2011-10-01

    Despite the major interest in membrane proteins at functional, genomic, and therapeutic levels, their biochemical and structural study remains challenging, as they require, among other things, solubilization in detergent micelles. The complexity of this task derives from the dependence of membrane protein structure on their anisotropic environment, influenced by a delicate balance between many different physicochemical properties. To study such properties in a small protein-detergent complex, we used fluorescence measurements and molecular dynamics (MD) simulations on the transmembrane part of glycophorin A (GpAtm) solubilized in micelles of dihexanoylphosphatidylcholine (DHPC) detergent. Fluorescence measurements show that DHPC has limited ability to solubilize the peptide, while MD provides a possible molecular explanation for this. We observe that the detergent molecules are balanced between two different types of interactions: cohesive interactions between detergent molecules that hold the micelle together, and adhesive interactions with the peptide. While the cohesive interactions are detergent mediated, the adhesion to the peptide depends on the specific interactions between the hydrophobic parts of the detergent and the topography of the peptide dictated by the amino acids. The balance between these two parameters results in a certain frustration of the system and rather slow equilibration. These observations suggest how molecular properties of detergents could influence membrane protein stabilization and solubilization.

  12. Detergent-Fearing Milk.

    ERIC Educational Resources Information Center

    Hill, Diane

    1997-01-01

    Describes an activity that demonstrates among the following: diffusion; cohesion and adhesion; properties of surface tension which include wicking, hydrophilic, and hydrophobic molecular behaviors; and break up of fat clusters by liquid dishwashing detergent. (DDR)

  13. Fabrication of long-acting drug release property of hierarchical porous bioglasses/polylactic acid fibre scaffolds for bone tissue engineering.

    PubMed

    Wang, Dan; Lin, Huiming; Jiang, Jingjie; Jin, Qumei; Li, Lei; Dong, Yan; Qu, Fengyu

    2015-04-01

    Hierarchical porous fibre scaffolds with mesoporous bioglasses (MBGs) and polylactic acid (PLA) were successfully fabricated by the electrospinning method. These compound scaffolds possess macropores with sizes of about 100 nm because of the solvent evaporation from the fibre and the mesoporous structure ( ∼4.0 nm) originated from MBGs. The biomineralisation ability was investigated in simulated body fluid. The fibre structure is beneficial for inducing the growth of hydroxyapatite. In addition, compared with pure MBGs, the materials (MP-1 and MP-2) exhibit a long-acting drug release process up to 140 h and the drug release process corresponds with the Fickian diffusion mechanism. With the special fibre morphology and the hierarchical porous structure, the MBGs/PLA fibre scaffolds are expected to have potential application for bone tissue repair and regeneration.

  14. Impact of urea on detergent micelle properties.

    PubMed

    Broecker, Jana; Keller, Sandro

    2013-07-01

    Co-solvents, such as urea, can entail drastic changes in the micellization behavior of detergents. We present a systematic quantification of the impact of urea on the critical micellar concentration, the micellization thermodynamics, and the micelle size in three homologous series of commonly used non-ionic alkyl detergents. To this end, we performed demicellization experiments by isothermal titration calorimetry and hydrodynamic size measurements by dynamic light scattering on alkyl maltopyranosides, cyclohexyl alkyl maltopyranosides, and alkyl glucopyranosides at urea concentrations of 0-8 M. For all detergents studied, we found that the critical micellar concentration increases exponentially because the absolute Gibbs free energy of micellization decreases linearly over the entire urea concentration range, as does the micelle size. In contrast, the enthalpic and entropic contributions to micellization reveal more complex, nonlinear dependences on urea concentration. Both free energy and size changes are more pronounced for long-chain detergents, which bury more apolar surface area upon micelle formation. The Gibbs free energy increments per methylene group within each detergent series depend on urea concentration in a linear fashion, although they result from the entropic term for alkyl maltosides but are of enthalpic origin for cyclohexyl alkyl maltosides. We compare our results to transfer free energies of amino acid side chains, relate them to protein-folding data, and discuss how urea-induced changes in detergent micelle properties affect in vitro investigations on membrane proteins.

  15. Dihydrotestosterone stimulates amino acid uptake and the expression of LAT2 in mouse skeletal muscle fibres through an ERK1/2-dependent mechanism.

    PubMed

    Hamdi, M M; Mutungi, G

    2011-07-15

    Dihydrotestosterone (DHT) has acute/non-genomic actions in adult mammalian skeletal muscles whose physiological functions are still poorly understood. Therefore, the primary aim of this study was to investigate the acute/non-genomic effects of DHT on amino acid uptake as well as the cellular signal transduction events underlying these actions in mouse fast- and slow-twitch skeletal muscle fibre bundles. 14C-Labelled amino acids were used to investigate the effects of DHT and testosterone (T) on amino acid uptake and pharmacological interventions were used to determine the cellular signal transduction events mediating these actions. While T had no effect on the uptake of isoleucine (Ile) and α-methylaminoisobutyric acid (MeAIB) in both fibre types, DHT increased their uptake in the fast-twitch fibre bundles. This effect was reversed by inhibitors of protein translation, the epidermal growth factor receptor (EGFR), system A, system L, mTOR and MEK. However, it was relatively insensitive to inhibitors of transcription, androgen receptors and PI3K/Akt. Additionally, DHT treatment increased the expression of LAT2 and the phosphorylation of the EGFR in the fast-twitch fibre bundles and that of ERK1/2, RSK1/2 and ATF2 in both fibre types. Also, it decreased the phosphorylation of eEF2 and increased the incorporation of Ile into proteins in both fibre types. Most of these effects were reversed by EGFR and MEK inhibitors. From these findings we suggest that another physiological function of the acute/non-genomic actions of DHT in isolated mammalian skeletal muscle fibres is to stimulate amino acid uptake. This effect is mediated through the EGFR and involves the activation of the MAPK pathway and an increase in LAT2 expression.

  16. The fermentable fibre inulin increases postprandial serum short-chain fatty acids and reduces free-fatty acids and ghrelin in healthy subjects.

    PubMed

    Tarini, Joshua; Wolever, Thomas M S

    2010-02-01

    It is thought that diets high in dietary fibre are associated with reduced risk for type 2 diabetes, at least in part because the short-chain fatty acids (SCFAs) produced during the colonic fermentation of fibre beneficially influence circulating concentrations of free-fatty acids (FFAs) and gut hormones involved in the regulation of blood glucose and body mass. However, there is a paucity of data showing this sequence of events in humans. Thus, our objective was to determine the effect of the fermentable fibre inulin on postprandial glucose, insulin, SCFA, FFA, and gut hormone responses in healthy subjects. Overnight fasted healthy subjects (n = 12) were studied for 6 h after consuming 400 mL drinks, containing 80 g high-fructose corn syrup (80HFCS), 56 g HFCS (56HFCS), or 56 g HFCS plus 24 g inulin (Inulin), using a randomized, single-blind, crossover design. A standard lunch was served 4 h after the test drink. Glucose and insulin responses after Inulin did not differ significantly from those after 80HFCS or 56HFCS. Serum acetate, propionate, and butyrate were significantly higher after Inulin than after HFCS drinks from 4-6 h. FFAs fell at a similar rate after all 3 test drinks, but were lower after Inulin than after 56HFCS at 4 h (0.40 +/- 0.06 vs. 0.51 +/- 0.06 mmol*L-1; p < 0.05). Compared with 56HFCS, Inulin significantly increased plasma glucagon-like peptide-1 concentrations at 30 min, and reduced ghrelin at 4.5 h and 6 h. The results are consistent with the hypothesis that dietary fibre increases the production of colonic SCFAs, which may reduce type 2 diabetes risk by reducing postprandial FFAs and favorably affecting gut hormones, which regulate food intake.

  17. Detergent-compatible bacterial amylases.

    PubMed

    Niyonzima, Francois N; More, Sunil S

    2014-10-01

    Proteases, lipases, amylases, and cellulases are enzymes used in detergent formulation to improve the detergency. The amylases are specifically supplemented to the detergent to digest starchy stains. Most of the solid and liquid detergents that are currently manufactured contain alkaline enzymes. The advantages of using alkaline enzymes in the detergent formulation are that they aid in removing tough stains and the process is environmentally friendly since they reduce the use of toxic detergent ingredients. Amylases active at low temperature are preferred as the energy consumption gets reduced, and the whole process becomes cost-effective. Most microbial alkaline amylases are used as detergent ingredients. Various reviews report on the production, purification, characterization, and application of amylases in different industry sectors, but there is no specific review on bacterial or fungal alkaline amylases or detergent-compatible amylases. In this mini-review, an overview on the production and property studies of the detergent bacterial amylases is given, and the stability and compatibility of the alkaline bacterial amylases in the presence of the detergents and the detergent components are highlighted.

  18. Free fatty acid receptor 2 and nutrient sensing: a proposed role for fibre, fermentable carbohydrates and short-chain fatty acids in appetite regulation.

    PubMed

    Sleeth, Michelle L; Thompson, Emily L; Ford, Heather E; Zac-Varghese, Sagen E K; Frost, Gary

    2010-06-01

    The way in which the composition of the diet may affect appetite, food intake and body weight is now receiving considerable attention in a bid to halt the global year-on-year rise in obesity prevalence. Epidemiological evidence suggests that populations who follow a fibre-rich, traditional diet are likely to have a lower body weight and improved metabolic parameters than their Western-diet counterparts. The colonic effects of fibre, and more specifically the SCFA that the fermentation process produces, may play a role in maintaining energy homeostasis via their action on the G-coupled protein receptor free fatty acid receptor 2 (FFA2; formerly GPR43). In the present review, we summarise the evidence for and against the role of FFA2 in energy homeostasis circuits and the possible ways that these could be exploited therapeutically. We also propose that the decline in fibre content of the diet since the Industrial Revolution, particularly fermentable fractions, may have resulted in the FFA2-mediated circuits being under-utilised and hence play a role in the current obesity epidemic.

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

    PubMed

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

    2011-12-01

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

  20. Detergent-mediated protein aggregation.

    PubMed

    Neale, Chris; Ghanei, Hamed; Holyoake, John; Bishop, Russell E; Privé, Gilbert G; Pomès, Régis

    2013-04-01

    Because detergents are commonly used to solvate membrane proteins for structural evaluation, much attention has been devoted to assessing the conformational bias imparted by detergent micelles in comparison to the native environment of the lipid bilayer. Here, we conduct six 500-ns simulations of a system with >600,000 atoms to investigate the spontaneous self assembly of dodecylphosphocholine detergent around multiple molecules of the integral membrane protein PagP. This detergent formed equatorial micelles in which acyl chains surround the protein's hydrophobic belt, confirming existing models of the detergent solvation of membrane proteins. In addition, unexpectedly, the extracellular and periplasmic apical surfaces of PagP interacted with the headgroups of detergents in other micelles 85 and 60% of the time, respectively, forming complexes that were stable for hundreds of nanoseconds. In some cases, an apical surface of one molecule of PagP interacted with an equatorial micelle surrounding another molecule of PagP. In other cases, the apical surfaces of two molecules of PagP simultaneously bound a neat detergent micelle. In these ways, detergents mediated the non-specific aggregation of folded PagP. These simulation results are consistent with dynamic light scattering experiments, which show that, at detergent concentrations ≥600 mM, PagP induces the formation of large scattering species that are likely to contain many copies of the PagP protein. Together, these simulation and experimental results point to a potentially generic mechanism of detergent-mediated protein aggregation.

  1. A comparative study on the graft copolymerization of acrylic acid onto rayon fibre by a ceric ion redox system and a γ-radiation method.

    PubMed

    Kaur, Inderjeet; Kumar, Raj; Sharma, Neelam

    2010-10-13

    Functionalization of rayon fibre has been carried out by grafting acrylic acid (AAC) both by a chemical method using a Ce(4+)-HNO(3) redox initiator and by a mutual irradiation (γ-rays) method. The reaction conditions affecting the grafting percentage have been optimized for both methods, and the results are compared. The maximum percentage of grafting (50%) by the chemical method was obtained utilizing 18.24 × 10(-3) moles/L of ceric ammonium nitrate (CAN), 39.68 × 10(-2) moles/L of HNO(3), and 104.08 × 10(-2) moles/L of AAc in 20 mL of water at 45°C for 120 min. For the radiation method, the maximum grafting percentage (60%) was higher, and the product was obtained under milder reaction conditions using a lower concentration of AAc (69.38 × 10(-2) moles/L) in 10 mL of water at an optimum total dose of 0.932 kGy. Swelling studies showed higher swelling for the grafted rayon fibre in water (854.54%) as compared to the pristine fibre (407%), while dye uptake studies revealed poor uptake of the dye (crystal violet) by the grafted fibre in comparison with the pristine fibre. The graft copolymers were characterized by IR, TGA, and scanning electron micrographic methods. Grafted fibre, prepared by the radiation-induced method, showed better thermal behaviour. Comparison of the two methods revealed that the radiation method of grafting of acrylic acid onto rayon fibre is a better method of grafting in comparison with the chemical method.

  2. Changes in amino acid concentration in plasma and type I and type II fibres during resistance exercise and recovery in human subjects.

    PubMed

    Blomstrand, Eva; Essén-Gustavsson, Birgitta

    2009-10-01

    Eight male subjects performed leg press exercise, 4 x 10 repetitions at 80% of their maximum. Venous blood samples were taken before, during exercise and repeatedly during 2 h of recovery. From four subjects, biopsies were taken from the vastus lateralis muscle prior to, immediately after and following one and 2 h of recovery. Samples were freeze-dried, individual muscle fibres were dissected out and identified as type I or type II. Resistance exercise led to pronounced reductions in the glutamate concentration in both type I (32%) and type II fibres (70%). Alanine concentration was elevated 60-75% in both fibre types and 29% in plasma. Glutamine concentration remained unchanged after exercise; although 2 h later the concentrations in both types of fibres were reduced 30-35%. Two hours after exercise, the plasma levels of glutamate and six of the essential amino acids, including the branched-chain amino acids were reduced 5-30%. The data suggest that glutamate acts as an important intermediate in muscle energy metabolism during resistance exercise, especially in type II fibres. PMID:18931969

  3. Effects of a polar amino acid substitution on helix formation and aggregate size along the detergent-induced peptide folding pathway.

    PubMed

    Alvares, Rohan D A; Tulumello, David V; Macdonald, Peter M; Deber, Charles M; Prosser, R Scott

    2013-02-01

    Membrane proteins constitute a significant fraction of the proteome and are important drug targets. While the transmembrane (TM) segments of these proteins are primarily composed of hydrophobic residues, the inclusion of polar residues-either naturally occurring or as a consequence of a disease-related mutation-places a significant folding burden in this environment, potentially impacting bilayer insertion and/or association of neighboring TM helices. Here we investigate the role of an anionic detergent, sodium dodecylsulfate (SDS), and a zwitterionic detergent, dodecylphosphocholine (DPC), in the folding process, and the effects induced by a single polar substitution, on structure and topology of model α-helical TM segments. The peptides, represented by KK-YAAAIAAIAWAXAAIAAAIAA-KKK-NH(2), where X is I or N, are designed with high aqueous solubilities, through poly-lysine tags. Circular dichroism (CD) and NMR were used to monitor peptide secondary structure and diffusional mobility of both peptide and the detergent hosts. For both peptides, SDS binding commenced at a concentration below its CMC, due to Coulombic attraction of anionic SDS to cationic Lys residues. Increasing SDS binding correlated with increasing peptide helicity. Pulsed field gradient (PFG) NMR diffusion measurements revealed that the Asn-containing peptide bound four fewer detergent molecules, corresponding to ca. 20% less SDS than bound by the Ile peptide. Conversely, zwitterionic DPC binding to either peptide was not observed until the DPC concentration approached its CMC. Our findings confirm quantitatively that a single polar residue within a TM segment may have a significant influence on its local membrane environment.

  4. Hydrofluoric-nitric-sulphuric-acid surface treatment of tungsten for carbon fibre-reinforced composite hybrids in space applications

    NASA Astrophysics Data System (ADS)

    Kanerva, M.; Johansson, L.-S.; Campbell, J. M.; Revitzer, H.; Sarlin, E.; Brander, T.; Saarela, O.

    2015-02-01

    Hybrid material systems, such as combinations of tungsten foils and carbon fibre-reinforced plastic (CFRP), are replacing metal alloy concepts in spacecraft enclosures. However, a good adhesion between the tungsten oxide scale and the epoxy resin used is required. Here, the effects of a hydrofluoric-nitric-sulphuric-acid (HFNS) treatment on tungsten oxides and subsequent adhesion to CFRP are analysed using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and fracture testing. The work shows that HFNS treatment results in decreased oxygen content, over 50% thinner tungsten trioxide (WO3) layer and increased nano-roughness on thin tungsten foils. Fracture testing established a 39% increase in the average critical strain for tungsten-CFRP specimens after HFNS treatment was carried out on tungsten. The effect of the oxide scale modification regarding the critical strain energy release rate was ΔGc≈ 8.4 J/m2.

  5. Detergent-mediated protein aggregation

    PubMed Central

    Neale, Chris; Ghanei, Hamed; Holyoake, John; Bishop, Russell E.; Privé, Gilbert G.; Pomès, Régis

    2016-01-01

    Because detergents are commonly used to solvate membrane proteins for structural evaluation, much attention has been devoted to assessing the conformational bias imparted by detergent micelles in comparison to the native environment of the lipid bilayer. Here, we conduct six 500-ns simulations of a system with >600,000 atoms to investigate the spontaneous self assembly of dodecylphosphocholine detergent around multiple molecules of the integral membrane protein PagP. This detergent formed equatorial micelles in which acyl chains surround the protein’s hydrophobic belt, confirming existing models of the detergent solvation of membrane proteins. In addition, unexpectedly, the extracellular and periplasmic apical surfaces of PagP interacted with the headgroups of detergents in other micelles 85 and 60% of the time, respectively, forming complexes that were stable for hundreds of nanoseconds. In some cases, an apical surface of one molecule of PagP interacted with an equatorial micelle surrounding another molecule of PagP. In other cases, the apical surfaces of two molecules of PagP simultaneously bound a neat detergent micelle. In these ways, detergents mediated the non-specific aggregation of folded PagP. These simulation results are consistent with dynamic light scattering experiments, which show that, at detergent concentrations ≥600 mM, PagP induces the formation of large scattering species that are likely to contain many copies of the PagP protein. Together, these simulation and experimental results point to a potentially generic mechanism of detergent-mediated protein aggregation. PMID:23466535

  6. Detergent-Free Membrane Protein Purification.

    PubMed

    Rothnie, Alice J

    2016-01-01

    Membrane proteins are localized within a lipid bilayer; in order to purify them for functional and structural studies the first step must involve solubilizing or extracting the protein from these lipids. To date this has been achieved using detergents which disrupt the bilayer and bind to the protein in the transmembrane region. However finding conditions for optimal extraction, without destabilizing protein structure, is time consuming and expensive. Here we present a recently-developed method using a styrene-maleic acid (SMA) co-polymer instead of detergents. The SMA co-polymer extracts membrane proteins in a small disc of lipid bilayer which can be used for affinity chromatography purification, thus enabling the purification of membrane proteins while maintaining their native lipid bilayer environment. PMID:27485341

  7. In vitro bile acid-binding capacity of dietary fibre sources and their effects with bile acid on broiler chicken performance and lipid digestibility.

    PubMed

    Hemati Matin, H R; Shariatmadari, F; Karimi Torshizi, M A; Chiba, L I

    2016-06-01

    A 4 × 2 factorial experiment was conducted to study the effect of feeding diets-containing dietary fibre (DF) sources and a source of bile acid (BA) on growth performance and lipid metabolism. In addition, in vitro BA-binding capacity of fibre sources was investigated. A total of 256 one-d-old male broiler chickens (Ross 308) were assigned to DF sources [maize-soybean meal (control, C), or 30 g/kg of wheat bran (WB), barley bran (BB) or soybean hulls (SH)] and BA (with or without 1.5 g Na-deoxycholate/kg). Each treatment was replicated 4 times with 8 broiler chickens per cage. The highest in vitro BA-binding capacity was observed with BB (8.76 mg/g BB). From 0 to 21 d, with the addition of BA, the average daily feed intake (ADFI) decreased in broiler chickens fed on the C, WB or BB diets, while there was no difference with the SH diet. With added BA, the average daily gain decreased in broiler chickens fed on the C or SH diets, but it did not change in those fed on the other diets. The addition of BA decreased feed conversion ratio (FCR) in broiler chickens fed on the BB or WB diets, but it increased in those fed on the C or SH diets. Interaction results indicated that the apparent ileal digestibility of lipid increased in broiler chickens fed the C and other DF diets with BA compared to those fed the diets without BA. The addition of BA decreased the pancreas lipase activity (PLA) in broiler chickens fed on the C diet compared to those fed the C diet without BA, while no changes observed in those fed the DF diets with or without BA. No interaction was observed in total liver bile acid (TLBA). The WB, BB and SH with little Na-deoxycholate-binding capacity (<10 mg/g of DF) under in vitro conditions had particular effects with BA on the measured criteria in broiler chickens. The magnitude of improvement in digestibility of lipid with the addition of BA depends on the source of fibre used and the addition of BA in DF diets had little effect on growth

  8. Suitability of hollow fibre liquid-phase microextraction for the determination of acidic pharmaceuticals in wastewater by liquid chromatography-electrospray tandem mass spectrometry without matrix effects.

    PubMed

    Quintana, José Benito; Rodil, Rosario; Reemtsma, Thorsten

    2004-12-17

    The applicability of hollow fibre liquid-phase microextraction (LPME), as an alternative to solid-phase extraction (SPE), for the extraction/enrichment of acidic drugs (e.g. ibuprofen, clofibric acid, bezafibrate, etc.) from water samples prior to the determination by LC-ESI-MS-MS has been evaluated. After LPME method optimisation, it was found that this technique can provide very clean extracts, which do not lead to signal suppression during LC-ESI-MS-MS analysis of the analytes. The limits of quantification (0.5-42 ng/L) are suitable for the analysis of these drugs in wastewater. However repeatability needs to been improved (intra-day R.S.D. = 3.4-32%), which may be expected by automation and the development of commercially available devices and fibres specially prepared for analytical purposes. The method was finally applied to wastewater samples (treated and untreated) and results comparable to SPE were obtained.

  9. Fibre typing of intrafusal fibres

    PubMed Central

    Thornell, Lars-Eric; Carlsson, Lena; Eriksson, Per-Olof; Liu, Jing-Xia; Österlund, Catharina; Stål, Per; Pedrosa-Domellöf, Fatima

    2015-01-01

    The first descriptions of muscle spindles with intrafusal fibres containing striated myofibrils and nervous elements were given approximately 150 years ago. It took, however, another 100 years to establish the presence of two types of intrafusal muscle fibres: nuclear bag and nuclear chain fibres. The present paper highlights primarily the contribution of Robert Banks in fibre typing of intrafusal fibres: the confirmation of the principle of two types of nuclear bag fibres in mammalian spindles and the variation in occurrence of a dense M-band along the fibres. Furthermore, this paper summarizes how studies from the Umeå University group (Laboratory of Muscle Biology in the Department of Integrative Medical Biology) on fibre typing and the structure and composition of M-bands have contributed to the current understanding of muscle spindle complexity in adult humans as well as to muscle spindle development and effects of ageing. The variable molecular composition of the intrafusal sarcomeres with respect to myosin heavy chains and M-band proteins gives new perspectives on the role of the intrafusal myofibrils as stretch-activated sensors influencing tension/stiffness and signalling to nuclei. PMID:26179023

  10. Correlating Detergent Fiber Analysis and Dietary Fiber Analysis Data for Corn Stover

    SciTech Connect

    Wolfrum, E. J.; Lorenz, A. J.; deLeon, N.

    2009-01-01

    There exist large amounts of detergent fiber analysis data [neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL)] for many different potential cellulosic ethanol feedstocks, since these techniques are widely used for the analysis of forages. Researchers working in the area of cellulosic ethanol are interested in the structural carbohydrates in a feedstock (principally glucan and xylan), which are typically determined by acid hydrolysis of the structural fraction after multiple extractions of the biomass. These so-called dietary fiber analysis methods are significantly more involved than detergent fiber analysis methods. The purpose of this study was to determine whether it is feasible to correlate detergent fiber analysis values to glucan and xylan content determined by dietary fiber analysis methods for corn stover. In the detergent fiber analysis literature cellulose is often estimated as the difference between ADF and ADL, while hemicellulose is often estimated as the difference between NDF and ADF. Examination of a corn stover dataset containing both detergent fiber analysis data and dietary fiber analysis data predicted using near infrared spectroscopy shows that correlations between structural glucan measured using dietary fiber techniques and cellulose estimated using detergent techniques, and between structural xylan measured using dietary fiber techniques and hemicellulose estimated using detergent techniques are high, but are driven largely by the underlying correlation between total extractives measured by fiber analysis and NDF/ADF. That is, detergent analysis data is correlated to dietary fiber analysis data for structural carbohydrates, but only indirectly; the main correlation is between detergent analysis data and solvent extraction data produced during the dietary fiber analysis procedure.

  11. Detection of antibiotics in goat's milk: effect of detergents on the response of microbial inhibitor tests.

    PubMed

    Romero, Tamara; Beltrán, María Carmen; Althaus, Rafael Lisandro; Molina, María Pilar

    2014-08-01

    The aim of the study was to evaluate the interference of acid and alkaline detergents employed in the cleaning of milking equipment of caprine dairy farms on the performance of microbial tests used in antibiotic control (BRT MRL, Delvotest MCS, and Eclipse 100). Eight concentrations of commercial detergents, five acid (0-0.25%) and five alkaline (0-1%) were add to antimicrobial-free goat's milk to evaluate the detergent effect on the response of microbial inhibitor tests. To evaluate the effect of detergents on the detection capability of microbial tests two detergents at 0.5 ml/l (one acid and one basic) and eight concentrations of four β-lactam antibiotics (ampicillin, amoxicillin, cloxacillin and benzylpenicillin) were used. Milk without detergents was used as control. The spiked samples were analysed twelve times by three microbial tests. The results showed that the presence of acid detergents did not affect the response of microbial tests for any of the concentrations tested. However, at concentrations equal to or greater than 2 ml/l alkaline detergents positive results were found in microbial tests (16.7-100%). The detection limits of the screening tests for penicillins were not modified substantially by the presence of detergents. In general, the presence of acid and alkaline detergents in goat's milk did not produce a great interference in the microbial tests, only high concentrations of detergents could cause non-compliant results, but these concentrations are difficult to find in practice if proper cleaning procedures are applied in goat dairy farms.

  12. Inactivation of avian influenza virus using common detergents and chemicals.

    PubMed

    Lombardi, M E; Ladman, B S; Alphin, R L; Benson, E R

    2008-03-01

    Six disinfectant chemicals were tested individually for effectiveness against low pathogenic avian influenza virus (LPAIV) A/H7N2/Chick/MinhMa/04. The tested agents included acetic acid (C2H4O2), citric acid (C6H8O7), calcium hypochlorite (Ca(ClO)2), sodium hypochlorite (NaOCl), a powdered laundry detergent with peroxygen (bleach), and a commercially available iodine/acid disinfectant. Four of the six chemicals, including acetic acid (5%), citric acid (1% and 3%), calcium hypochlorite (750 ppm), and sodium hypochlorite (750 ppm) effectively inactivated LPAIV on hard and nonporous surfaces. The conventional laundry detergent was tested at multiple concentrations and found to be suitable for inactivating LPAIV on hard and nonporous surfaces at 6 g/L. Only citric acid and commercially available iodine/acid disinfectant were found to be effective at inactivating LPAIV on both porous and nonporous surfaces.

  13. Correlative microscopy of detergent granules.

    PubMed

    van Dalen, G; Nootenboom, P; Heussen, P C M

    2011-03-01

    The microstructure of detergent products for textile cleaning determines to a large extent the physical properties of these products. Correlative microscopy was used to reveal the microstructure by reconciling images obtained by scanning electron microscopy with energy dispersive X-ray analysis, X-ray microtomography and Fourier transform infrared microscopy. These techniques were applied on the same location of a subsample of a spray-dried detergent base powder embedded in polyacrylate. In this way, the three-dimensional internal and external structure of detergent granules could be investigated from milli to nano scale with detailed spatial information about the components present. This will generate knowledge how to design optimal microstructures for laundry products to obtain product properties demanded by the market. This method is also very useful for other powder systems used in a large variety of industries (e.g. for pharmaceutical, food, ceramic and metal industries).

  14. Detergent phosphate bans and eutrophication

    SciTech Connect

    Lee, G.F.; Jones, R.A.

    1986-04-01

    The Vollenweider-OECD eutrophication model has been expanded to approximately 400 lakes. It is possible to make a quantitative prediction of the effects of a detergent phosphate ban and thereby to ascertain the potential benefits of such a ban. In order to assess the effect of a detergent phosphate ban on water quality it is necessary to know the percentage of phosphorus in the domestic waste water that enters the water body, either directly or indirectly, and the percentage of the total phosphorus load that is derived from domestic wastewater. Although detergent phosphate bans generally will not result in an overall improvement to water quality, there may be some situations in which eutrophication-related water quality would be improved by a ban. 8 references, 1 figure, 1 table.

  15. Effects of household detergent on anaerobic fermentation of kitchen wastewater from food waste disposer.

    PubMed

    Lee, K H; Park, K Y; Khanal, S K; Lee, J W

    2013-01-15

    This study examines the effects of household detergent on anaerobic methane fermentation of wastewater from food waste disposers (FWDs). Anaerobic toxicity assay (ATA) demonstrated that methane production substantially decreased at a higher detergent concentration. The Gompertz three-parameter model fitted well with the ATA results, and both the extent of methane production (M) and methane production rate (R(m)) obtained from the model were strongly affected by the concentration of the detergent. The 50% inhibitory concentration (IC(50)) of the detergent was 603 mg/L based on R(m). Results from fatty acid methyl esters (FAMEs) analysis of microbial culture revealed that deterioration of methane fermentation was attributed to impaired structure of anaerobic microbial membrane due to detergent. This study suggests that wastewater from FWD could be used for methane production, but it is necessary to reduce the concentration of detergent prior to anaerobic fermentation.

  16. Shell may expand detergent alcohols

    SciTech Connect

    1996-10-23

    Shell Chemical is studying plans to expand detergent alcohols capacity in the US, CW has learned. The company is considering adding capacity for about 80 million lbs/year. If the project is approved, it would be implemented at the company`s Geismar, LA site. Shell will make a final decision on whether to proceed with the project within six months. It has been rumored to be considering a capacity addition as a result of tightening supply of natural and synthetic detergent alcohols.

  17. 40 CFR 180.1022 - Iodine-detergent complex; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Iodine-detergent complex; exemption... FOOD Exemptions From Tolerances § 180.1022 Iodine-detergent complex; exemption from the requirement of a tolerance. The aqueous solution of hydriodic acid and elemental iodine, including one or both...

  18. 40 CFR 180.1022 - Iodine-detergent complex; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Iodine-detergent complex; exemption... FOOD Exemptions From Tolerances § 180.1022 Iodine-detergent complex; exemption from the requirement of a tolerance. The aqueous solution of hydriodic acid and elemental iodine, including one or both...

  19. 40 CFR 180.1022 - Iodine-detergent complex; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Iodine-detergent complex; exemption... FOOD Exemptions From Tolerances § 180.1022 Iodine-detergent complex; exemption from the requirement of a tolerance. The aqueous solution of hydriodic acid and elemental iodine, including one or both...

  20. 40 CFR 180.1022 - Iodine-detergent complex; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Iodine-detergent complex; exemption... FOOD Exemptions From Tolerances § 180.1022 Iodine-detergent complex; exemption from the requirement of a tolerance. The aqueous solution of hydriodic acid and elemental iodine, including one or both...

  1. 40 CFR 180.1022 - Iodine-detergent complex; exemption from the requirement of a tolerance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Iodine-detergent complex; exemption... FOOD Exemptions From Tolerances § 180.1022 Iodine-detergent complex; exemption from the requirement of a tolerance. The aqueous solution of hydriodic acid and elemental iodine, including one or both...

  2. Short-chain fatty acids produced in vitro from fibre residues obtained from mixed diets containing different breads and in human faeces during the ingestion of the diets.

    PubMed

    Wisker, E; Daniel, M; Rave, G; Feldheim, W

    2000-07-01

    It was studied whether the type of bread (i.e. a low-fibre wheat-rye mixed bread and coarse or fine wholemeal rye bread) either as part of a diet or alone, had an influence on the short-chain fatty acids (SCFA) produced during in vitro fermentation. Fermentation substrates were dietary fibre residues obtained from diets and breads. In addition, it was investigated whether the faecal SCFA pattern in the inoculum donors, who ingested the experimental diets, could be predicted by in vitro fermentation. Yields of SCFA in vitro were 0.51-0.62 g/g fermented polysaccharide. In vitro, the molar ratios of butyrate were higher for the two high-fibre diets containing coarse or fine wholemeal bread than for the low fibre diet containing wheat-rye mixed bread; the difference was significant for the coarse (P < 0.01), but not for the fine bread diet (P = 0.0678). The coarse wholemeal bread alone produced a higher molar ratio of butyrate than the fine wholemeal bread (P < 0.05) and the wheat-rye mixed bread (P < 0.01). Ingestion by the inoculum donors of the diets containing wholemeal bread led to higher faecal butyrate ratios (molar ratios: coarse bread diet 19.6, fine bread diet 17.7) compared with the wheat-rye mixed bread-containing diet (14.9), but the differences between the diets were not significant. For the diets investigated, there were no significant differences between faecal and in vitro SCFA patterns.

  3. Soaps and Detergents--A 'Social' Treatment.

    ERIC Educational Resources Information Center

    Rust, S. C.

    1979-01-01

    Describes how social aspects of science can be incorporated into teaching soap and detergents in British secondary chemistry and general science courses. Historical background to the use and production of soap and the development of detergents are also presented. (HM)

  4. Thermodynamic characterization of the exchange of detergents and amphipols at the surfaces of integral membrane proteins.

    PubMed

    Tribet, C; Diab, C; Dahmane, T; Zoonens, M; Popot, J-L; Winnik, F M

    2009-11-01

    The aggregation of integral membrane proteins (IMPs) in aqueous media is a significant concern for mechanistic investigations and pharmaceutical applications of this important class of proteins. Complexation of IMPs with amphiphiles, either detergents or short amphiphilic polymers known as amphipols (APols), renders IMPs water-soluble. It is common knowledge that IMP-detergent complexes are labile, while IMP-APol complexes are exceptionally stable and do not dissociate even under conditions of extreme dilution. To understand the thermodynamic origin of this difference in stability and to guide the design of new APols, we have studied by isothermal titration calorimetry (ITC) the heat exchanges during two reciprocal processes, the "trapping" of detergent-solubilized IMPs in APols and the "stripping" of IMP-APol complexes by detergents, using two IMPs (the transmembrane domain of porin OmpA from Escherichia coli and bacteriorhodopsin from Halobium salinarium), two APols [an anionic polymer derived from acrylic acid (A8-35) and a cationic phosphorylcholine-based polymer (C22-43)], and two neutral detergents [n-octyl thioglucoside (OTG) and n-octyltetraethylene glycol (C(8)E(4))]. In the presence of detergent, free APols and IMP-APol complexes form mixed particles, APol-detergent and IMP-APol-detergent, respectively, according to the regular mixing model. Diluting IMP-APol-detergent complexes below the critical micellar concentration (CMC) of the detergent triggers the dispersion of detergent molecules as monomers, a process characterized by an enthalpy of demicellization. The enthalpy of APol <--> detergent exchange on the hydrophobic surface of IMPs is negligibly small, an indication of the similarity of the molecular interactions of IMPs with the two types of amphiphiles. The enhanced stability against dilution of IMP-APol complexes, compared to IMP-detergent ones, originates from the difference in entropy gain achieved upon release in water of a few APol molecules

  5. Intermolecular detergent-membrane protein noes for the characterization of the dynamics of membrane protein-detergent complexes.

    PubMed

    Eichmann, Cédric; Orts, Julien; Tzitzilonis, Christos; Vögeli, Beat; Smrt, Sean; Lorieau, Justin; Riek, Roland

    2014-12-11

    The interaction between membrane proteins and lipids or lipid mimetics such as detergents is key for the three-dimensional structure and dynamics of membrane proteins. In NMR-based structural studies of membrane proteins, qualitative analysis of intermolecular nuclear Overhauser enhancements (NOEs) or paramagnetic resonance enhancement are used in general to identify the transmembrane segments of a membrane protein. Here, we employed a quantitative characterization of intermolecular NOEs between (1)H of the detergent and (1)H(N) of (2)H-perdeuterated, (15)N-labeled α-helical membrane protein-detergent complexes following the exact NOE (eNOE) approach. Structural considerations suggest that these intermolecular NOEs should show a helical-wheel-type behavior along a transmembrane helix or a membrane-attached helix within a membrane protein as experimentally demonstrated for the complete influenza hemagglutinin fusion domain HAfp23. The partial absence of such a NOE pattern along the amino acid sequence as shown for a truncated variant of HAfp23 and for the Escherichia coli inner membrane protein YidH indicates the presence of large tertiary structure fluctuations such as an opening between helices or the presence of large rotational dynamics of the helices. Detergent-protein NOEs thus appear to be a straightforward probe for a qualitative characterization of structural and dynamical properties of membrane proteins embedded in detergent micelles.

  6. Concentrated liquid detergent pod ingestion in children.

    PubMed

    Sidhu, Natasha; Jaeger, Matthew W

    2014-12-01

    Concentrated liquid detergent pods are an emerging public health hazard, especially in pediatric patients. Ingestion is a more common route of exposure for liquid detergent pods compared with non-pod detergents and it tends to be associated with more severe adverse effects. We present 3 cases that demonstrate the varied clinical symptoms resulting from detergent pod ingestion. These cases not only demonstrate findings such as gastrointestinal and respiratory symptoms but also show more rare neurological symptoms. The cases highlight the dangers of concentrated liquid detergent pod ingestion. To help prevent further life-threatening injuries, there is a need for more consumer information and provider knowledge about the potential adverse complications.

  7. Affinity Chromatography in Nonionic Detergent Solutions

    NASA Astrophysics Data System (ADS)

    Robinson, Jack B.; Strottmann, James M.; Wick, Donald G.; Stellwagen, Earle

    1980-10-01

    Anionic dye affinity chromatography is commonly unproductive in the presence of nonionic detergents used to extract particulate proteins. Using lactate dehydrogenase as a model protein, Cibacron blue F3GA as a model dye, and Triton X-100 as a model detergent, we find that the dye is encapsulated in nonionic detergent micelles, rendering the dye incapable of ligation with the enzyme. However, the dye can be liberated from the micelles without altering the nonionic detergent concentration by addition of an anionic detergent, such as deoxycholate or sodium dodecyl sulfate, forming mixed anionic/nonionic micelles that displace the anionic dye. Encapsulation of the anionic detergents prevents their activity as protein denaturants. These observations have been successfully translated to the dye affinity chromatography of a detergent extract of brain particulate cyclic nucleotide phosphodiesterase.

  8. Evaluation of the feeding value of palm press fibre using in vitro digestibility techniques.

    PubMed

    Obese, F Y; Osafo, E L; Okai, D B

    2001-04-01

    Palm press fibre (PPF) was obtained from two sources, a small-scale oil palm processing unit and a large-scale factory processing unit, and its chemical composition was determined. In vitro digestibility techniques were used to assess the feeding value of untreated, defatted and sodium hydroxide-treated PPF. For the NaOH treatment, 0.5 g oven-dried PPF was treated for 24 h with 5% NaOH in three ways: treated and not washed (NaNW); treated and washed (NaW); and treated after milling (NAD). The results indicate that, on a dry matter basis, PPF is low in nitrogen (12-13 g/kg), moisture (37-90 g/kg) and ash (53-62 g/kg), but high in ether extract (269-355 g/kg), neutral detergent fibre (532-768 g/kg), acid detergent fibre (375-548 g/kg) and lignin (219 g/kg). The in vitro dry matter digestibility values were low for the samples from both sources, but the large-scale factory-processed PPF had higher in vitro dry matter digestibility (0.215 vs 0.166) and in vitro organic matter digestibility (0.196 vs 0.145). Defatting the PPF and treating it with 5% NaOH solution significantly (p < 0.01) improved both the dry matter and organic matter digestibility. Washing the NaOH-treated PPF resulted in a higher digestibility of dry matter as against NaNW or NAD. These results suggest that defatting and treatment with 5% NaOH would improve the feeding value of PPF. PMID:11254076

  9. Evaluation of the feeding value of palm press fibre using in vitro digestibility techniques.

    PubMed

    Obese, F Y; Osafo, E L; Okai, D B

    2001-04-01

    Palm press fibre (PPF) was obtained from two sources, a small-scale oil palm processing unit and a large-scale factory processing unit, and its chemical composition was determined. In vitro digestibility techniques were used to assess the feeding value of untreated, defatted and sodium hydroxide-treated PPF. For the NaOH treatment, 0.5 g oven-dried PPF was treated for 24 h with 5% NaOH in three ways: treated and not washed (NaNW); treated and washed (NaW); and treated after milling (NAD). The results indicate that, on a dry matter basis, PPF is low in nitrogen (12-13 g/kg), moisture (37-90 g/kg) and ash (53-62 g/kg), but high in ether extract (269-355 g/kg), neutral detergent fibre (532-768 g/kg), acid detergent fibre (375-548 g/kg) and lignin (219 g/kg). The in vitro dry matter digestibility values were low for the samples from both sources, but the large-scale factory-processed PPF had higher in vitro dry matter digestibility (0.215 vs 0.166) and in vitro organic matter digestibility (0.196 vs 0.145). Defatting the PPF and treating it with 5% NaOH solution significantly (p < 0.01) improved both the dry matter and organic matter digestibility. Washing the NaOH-treated PPF resulted in a higher digestibility of dry matter as against NaNW or NAD. These results suggest that defatting and treatment with 5% NaOH would improve the feeding value of PPF.

  10. Alkaline detergent recycling via ultrafiltration

    SciTech Connect

    Steffani, C.; Meltzer, M.

    1995-06-01

    The metal finishing industry uses alkaline cleaners and detergents to remove oils and dirt from manufactured parts, often before they are painted or plated. The use of these cleaners has grown because environmental regulations are phasing out ozone depleting substances and placing restrictions on the use and disposal of many hazardous solvents. Lawrence Livermore National Laboratory is examining ultrafiltration as a cleaning approach that reclaims the cleaning solutions and minimizes wastes. The ultrafiltration membrane is made from sheets of polymerized organic film. The sheets are rolled onto a supporting frame and installed in a tube. Spent cleaning solution is pumped into a filter chamber and filtered through the membrane that captures oils and dirt and allows water and detergent to pass. The membrane is monitored and when pressure builds from oil and dirt, an automatic system cleans the surface to maintain solution flow and filtration quality. The results show that the ultrafiltration does not disturb the detergent concentration or alkalinity but removed almost all the oils and dirt leaving the solution in condition to be reused.

  11. Exploring the protein stability landscape: Bacillus subtilis lipase A as a model for detergent tolerance.

    PubMed

    Fulton, Alexander; Frauenkron-Machedjou, Victorine Josiane; Skoczinski, Pia; Wilhelm, Susanne; Zhu, Leilei; Schwaneberg, Ulrich; Jaeger, Karl-Erich

    2015-04-13

    A systematic study was conducted with Bacillus subtilis lipase A (BSLA) to determine the effect of every single amino acid substitution on detergent tolerance. BSLA is a minimal α/β-hydrolase of 181 amino acids with a known crystal structure. It can be expressed in Escherichia coli and is biochemically well characterized. Site saturation mutagenesis resulted in a library of 3439 variants, each with a single amino acid exchange as confirmed by DNA sequencing. The library was tested against four detergents, namely SDS, CTAB, Tween 80, and sulfobetaine. Surface remodeling emerged as an effective engineering strategy to increase tolerance towards detergents. Amino acid residues that significantly affect the tolerance for each of the four detergents were identified. In summary, this systematic analysis provides an experimental dataset to help derive novel protein engineering strategies as well as to direct modeling efforts.

  12. Detergent-like stressor and nutrient in metabolism of Penicillium chrysogenum

    PubMed Central

    Jakovljević, Violeta; Milićević, Jasmina; Stojanović, Jelica

    2014-01-01

    The influence of detergents on the metabolism of Penicillium chrysogenum from two aspects, as a stress factor and potential nutrient, was studied. The fungus was isolated from the river bed Lepenica, Kragujevac, at a place where sewage domestic wastewater discharged into the river. The fungus was grown in a liquid nutrient medium according to Czapek with and without addition of commercial detergent (MERIX, Henkel, Serbia) at a concentration of 0.3% and 0.5%. The biochemical changes of pH, redox potential, free and total organic acids, total dry weight biomass, activity of alkaline and acid invertase and alkaline phosphatase were evaluated from day 3 to day 16 of the fungus growth. At the same time, detergent disappearance in terms of methylene blue active substances in the medium was measured. The detergent at a concentration of 0.5% showed a fungicide effect. In the medium with 0.3% of detergent, there was increased pH and concentration of organic acids, but decreased redox potential and total dry weight biomass. The detergent also showed an inhibitory effect on invertase and phosphatase activity. P. chrysogenum decomposed 50.2% of the total detergent concentration for an experimental period of 16 days. PMID:26019487

  13. Bacterial degradation of detergent compounds.

    PubMed

    Goodnow, R A; Harrison, A P

    1972-10-01

    A survey for surfactant degradation among aerobic bacteria has been undertaken. Tests have been made in peptone medium where such a degradation, if it occurs, will be gratuitous. Tallow-alkyl-sulfate, alkyl-ethoxylate-sulfate, and linear-alkyl-benzene-sulfonate were used. Forty-five strains of 34 species in 19 genera degrade one or more of these detergent compounds. With some species, the surfactant inhibits degradation without inhibiting growth, whereas with one species slight degradation took place even at a toxic concentration of surfactant.

  14. Detergents in Membrane Protein Purification and Crystallisation.

    PubMed

    Anandan, Anandhi; Vrielink, Alice

    2016-01-01

    Detergents play a significant role in structural and functional characterisation of integral membrane proteins (IMPs). IMPs reside in the biological membranes and exhibit a great variation in their structural and physical properties. For in vitro biophysical studies, structural and functional analyses, IMPs need to be extracted from the membrane lipid bilayer environment in which they are found and purified to homogeneity while maintaining a folded and functionally active state. Detergents are capable of successfully solubilising and extracting the IMPs from the membrane bilayers. A number of detergents with varying structure and physicochemical properties are commercially available and can be applied for this purpose. Nevertheless, it is important to choose a detergent that is not only able to extract the membrane protein but also provide an optimal environment while retaining the correct structural and physical properties of the protein molecule. Choosing the best detergent for this task can be made possible by understanding the physical and chemical properties of the different detergents and their interaction with the IMPs. In addition, understanding the mechanism of membrane solubilisation and protein extraction along with crystallisation requirements, if crystallographic studies are going to be undertaken, can help in choosing the best detergent for the purpose. This chapter aims to present the fundamental properties of detergents and highlight information relevant to IMP crystallisation. The first section of the chapter reviews the physicochemical properties of detergents and parameters essential for predicting their behaviour in solution. The second section covers the interaction of detergents with the biologic membranes and proteins followed by their role in membrane protein crystallisation. The last section will briefly cover the types of detergent and their properties focusing on custom designed detergents for membrane protein studies.

  15. Detergents in Membrane Protein Purification and Crystallisation.

    PubMed

    Anandan, Anandhi; Vrielink, Alice

    2016-01-01

    Detergents play a significant role in structural and functional characterisation of integral membrane proteins (IMPs). IMPs reside in the biological membranes and exhibit a great variation in their structural and physical properties. For in vitro biophysical studies, structural and functional analyses, IMPs need to be extracted from the membrane lipid bilayer environment in which they are found and purified to homogeneity while maintaining a folded and functionally active state. Detergents are capable of successfully solubilising and extracting the IMPs from the membrane bilayers. A number of detergents with varying structure and physicochemical properties are commercially available and can be applied for this purpose. Nevertheless, it is important to choose a detergent that is not only able to extract the membrane protein but also provide an optimal environment while retaining the correct structural and physical properties of the protein molecule. Choosing the best detergent for this task can be made possible by understanding the physical and chemical properties of the different detergents and their interaction with the IMPs. In addition, understanding the mechanism of membrane solubilisation and protein extraction along with crystallisation requirements, if crystallographic studies are going to be undertaken, can help in choosing the best detergent for the purpose. This chapter aims to present the fundamental properties of detergents and highlight information relevant to IMP crystallisation. The first section of the chapter reviews the physicochemical properties of detergents and parameters essential for predicting their behaviour in solution. The second section covers the interaction of detergents with the biologic membranes and proteins followed by their role in membrane protein crystallisation. The last section will briefly cover the types of detergent and their properties focusing on custom designed detergents for membrane protein studies. PMID:27553232

  16. Soaps and detergents: understanding their composition and effect.

    PubMed

    Kirsner, R S; Froelich, C W

    1998-03-01

    Soaps have been used for thousands of years as part of religious ceremonies and daily life. Derived from fatty acids or triglycerides (fats or oils) into their alkali derivatives through a process called saponification, soaps are important for healthcare professionals in preventing the spread of disease. Partly due to their alkaline nature, soaps are limited by their irritancy to the skin and their tendency to form insoluble and inactive salts when combined with either hard water or sea water. Therefore, soap alternatives or synthetic detergents have been developed. Detergents are classified into four groups: anionic, cationic, amphoteric, and non-ionic. These four groups are based on the hydrophilic qualities and surfactants they possess. Each group has characteristics that pertain to its main uses, irritancy, and toxicity. Understanding soaps and detergents may assist clinicians in making intelligent choices when using these agents on their patients as either skin cleansers or wound cleansers. Understanding the characteristics of soaps and detergents is especially important when dealing with at-risk patients such as the elderly.

  17. 40 CFR 80.163 - Detergent certification options.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Detergent certification options. 80... (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.163 Detergent certification options. To be used to satisfy the detergency requirements under § 80.161(a), a detergent additive must...

  18. 40 CFR 80.163 - Detergent certification options.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Detergent certification options. 80... (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.163 Detergent certification options. To be used to satisfy the detergency requirements under § 80.161(a), a detergent additive must...

  19. 40 CFR 80.163 - Detergent certification options.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Detergent certification options. 80... (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.163 Detergent certification options. To be used to satisfy the detergency requirements under § 80.161(a), a detergent additive must...

  20. 40 CFR 80.163 - Detergent certification options.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Detergent certification options. 80... (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.163 Detergent certification options. To be used to satisfy the detergency requirements under § 80.161(a), a detergent additive must...

  1. Corneal injuries from liquid detergent pods.

    PubMed

    Gray, Michael E; West, Constance E

    2014-10-01

    Laundry and dishwasher detergent "pods" were introduced to the United States market in 2010 and are sold by several manufacturers. They represent a high percentage of household cleaning product exposure in the United Kingdom. We present a consecutive case series of 10 children seen in a 9-month period with corneal injuries from exposure to liquid detergent pods.

  2. Nutrient digestibility and energy value of sheep rations differing in protein level, main protein source and non-forage fibre source.

    PubMed

    Milis, Ch; Liamadis, D

    2008-02-01

    Two in vivo digestion trials were conducted to evaluate the effects of diet's crude protein (CP) level, N degradability, and non-forage fibre source (NFFS) on nutrient digestibility and energy value of sheep rations. In each trial, rams were fed four isocaloric and isofibrous rations, differing in main protein and/or NFFS source. At the first trial, mean CP/metabolizable energy (ME) ratio of the diets was 17 g/MJ ME and at the second trial, 13 g/MJ ME. At both trials, the first ration contained cotton seed cake (CSC) and wheat bran (WB), the second CSC and corn gluten feed (CGF), the third corn gluten meal (CGM) and WB and the fourth CGM and CGF. Data of both trials were analysed in common as 2 x 2 x 2 factorial experimental design. Low N degradability (CGM) had positive effect on CP, neutral detergent fibre (NDF) and acid detergent fibre (ADF) digestibility of the ration. Those results suggest that an increase in rumen undegradable protein (RUP) content does not negatively affect nutrient digestibility of sheep rations. Corn gluten feed significantly elevated crude fibre (CF) digestibility, in comparison with WB. Rations having high CP/ME ratio had higher digestibility of CP in comparison with those having low CP/ME ratio; the opposite was true for ether extract, CF, NDF and ADF digestibilities. CP level x N degradability interaction negatively affected energy value of the rations that had high CP level and high N degradability. Former suggest that when CP content is high then N degradability should be low otherwise ration's ME is negatively affected. CP digestibility and coefficient q of the rations containing WB and having high N degradability (N degradability x NFFS interaction) were the lowest suggesting that the combination of CSC and WB negatively affected CP digestibility and energy value of the ration. This could be explained by a reduced microbial CP synthesis, or lower RUP digestibility or both. PMID:18184379

  3. The influence of detergents on the availability of pertussis toxin substrates.

    PubMed

    Morris, S A; Horn, E M; Hawley, T; Manning, D; Bilezikian, J P

    1991-10-01

    Pertussis toxin-dependent ADP-ribosylation of rat heart and human mononuclear leukocyte membranes was found to be markedly enhanced in the presence of detergents. The order of potency for this effect of detergents was Triton X-100 approximately Lubrol PX greater than digitonin much greater than cholate greater than 3-[(3-cholamidopropyl)dimethylammonia]propanesulfonic acid. Exposure of membranes to increasing concentrations of detergents increased the proportion of pertussis toxin substrate demonstrable in the supernatant fraction whereas the substrate remaining in the pellet fraction demonstrated a complicated relationship with the concentration of detergent. In complementary experiments, it was found that immunochemical detection of G proteins in the pellet fraction from suspensions previously incubated with a maximal concentration of detergent revealed a reduced presence of G proteins with a concomitant increase in the concentration of G proteins in the supernatant fraction; this situation was not observed at submaximal concentrations of detergent during the preincubation of myocardial membranes. The results suggest that the detergent-mediated enhancement of pertussis toxin's action to ADP-ribosylate susceptible G proteins is a complicated process that includes concentration-dependent creation of conditions favorable to the actions of the toxin as well as solubilization of the substrates for the toxin.

  4. The safety of synthetic zeolites used in detergents.

    PubMed

    Fruijtier-Pölloth, Claudia

    2009-01-01

    Synthetic zeolites are replacing phosphates as builders in laundry detergents; workers and consumers may, therefore, increasingly be exposed to these materials and it is important to assess their safety. This article puts mechanistic, toxicological and exposure data into context for a safety assessment. Zeolites are hygroscopic compounds with ion-exchanging properties. They may partially decompose under acidic conditions such as in the stomach releasing sodium ions, silicic acid and aluminum salts. The intact molecule is not bioavailable after oral intake or exposure through the dermal and inhalational routes. Under current conditions of manufacture and use, no systemic toxicity is to be expected from neither the intact molecule nor the degradation products; a significant effect on the bioavailability of other compounds is not likely. Zeolites may cause local irritation. It is, therefore, important to minimise occupational exposure. The co-operation of detergent manufacturers with the manufacturers of washing machines is necessary to find the right balance between environmental aspects such as energy and water savings and the occurrence of detergent residues on textiles due to insufficient rinsing.

  5. Detergents enhance EspB secretion from Escherichia coli strains harboring the locus for the enterocyte effacement (LEE) gene.

    PubMed

    Nakasone, Noboru; Toma, Claudia; Higa, Naomi; Koizumi, Yukiko; Ogura, Yasunori; Suzuki, Toshihiko

    2011-02-01

    The effects of detergents (cholic acid, deoxycholic acid, Triton X-100, and Nonidet P-40) on the secretion of EspB from the locus for enterocyte effacement (LEE) gene-positive Escherichia coli strains were examined. Clinical isolates of eight EPEC strains and seven STEC strains were used to detect EspB after they had been cultivated in Luria-Bertani (LB) broth containing one of the detergents. When the bacteria were cultured in LB broth supplemented with one of the detergents, the amount of EspB produced was increased by 2-32-fold depending on the detergent and the strain used. EspB was detected in all strains when they were cultured in LB broth containing all of the detergents. The results obtained in this study can be applied to immunological diagnostic methods for detecting EspB and also to the production of EspB for research purposes.

  6. Detergent water use eliminates VOC concerns

    SciTech Connect

    Chang, M.

    1996-01-01

    The article describes an electronics manufacturer`s use of detergent water and mechanical equipment (heated pressure washers and floor scrubbers) to replace volatile organic compounds. The cleaning formula development and detergent recovery system are emphasized. Detailed chemical analyses of the waste detergent water and spent filters are provided. The rationale for using detergent water; a process flow diagram for cleaning, recovery and storage; and cost considerations are summarized. At a cost of $300,000, the system removed a significant source of air emissions and enabled the plant to eliminate 30 tons of liquid hazardous waste, improve cleaning effectiveness, and save $99,000 per year in cleaning-related costs. 2 figs., 2 tabs.

  7. Detergent-Specific Membrane Protein Crystallization Screens

    NASA Technical Reports Server (NTRS)

    Wiener, Michael

    2007-01-01

    A suite of reagents has been developed for three-dimensional crystallization of integral membranes present in solution as protein-detergent complexes (PDCs). The compositions of these reagents have been determined in part by proximity to the phase boundaries (lower consolute boundaries) of the detergents present in the PDCs. The acquisition of some of the requisite phase-boundary data and the preliminary design of several of the detergent- specific screens was supported by a NASA contract. At the time of expiration of the contract, a partial set of preliminary screens had been developed. This work has since been extended under non-NASA sponsorship, leading to near completion of a set of 20 to 30 different and unique detergent- specific 96-condition screens.

  8. Combination detergent/MALDI matrix: functional cleavable detergents for mass spectrometry.

    PubMed

    Norris, Jeremy L; Porter, Ned A; Caprioli, Richard M

    2005-08-01

    This study reports the synthesis of the first functional cleavable detergent designed specifically for applications in mass spectrometry. Upon cleavage, two inert compounds and the MALDI matrix are formed, eliminating sources of potential interference originating from traditional cleavable detergents. Analysis of peptides demonstrates that MALDI matrix generated in situ results in MALDI spectra equivalent to those prepared using established protocols. Analysis of the membrane protein diacylglycerol kinase was accomplished using the combination detergent/MALDI matrix. Applications of the functional cleavable detergents to the profiling of whole cell lysates results in increased signal-to-noise ratios of many ions and the detection of additional proteins previously not observed.

  9. Synthesis of basic and overbasic sulfonate detergent additives

    SciTech Connect

    Abou El Naga, H.H.; Abd El-Azim, W.M.; Bendary, S.A.; Awad, N.G.

    1993-12-01

    Heavy alkylbenzene, which accumulates as a by-product from linear alkylbenzene synthesis, is evaluated as a starting material for preparation of basic and over basic sulfonate detergent additives. Chemical structure analysis showed that this by-product contains several components in different proportions. Most of these components, as traced via mass spectrometry, showed the presence of paraffinic side chains within the carbon range C{sub 11}--C{sub 22}. Accordingly, sulfonation conditions for it were adjusted to optimize the reaction yield and sulfonic quality. Neutralization of the sulfonic acid was carried out by adding CaO in the presence of methanol as a promoter. Preparation of over basic sulfonate was run via a carbonation process at 55--60 C. Evaluations of synthesized basic calcium sulfonate in comparison to a commercial additive is supported by its efficiency as a detergent additive. The synthesized product has a higher total base number and Ca content than those for the commercial one. On the other hand, evaluation of the synthesized overbasic calcium sulfonate compared with overbasic commercial additives with medium and high alkalinity indicated that the synthesized product can be classified as overbasic calcium sulfonate with medium alkalinity, good dispersive power, and detergent efficiency.

  10. Multimaterial piezoelectric fibres

    NASA Astrophysics Data System (ADS)

    Egusa, S.; Wang, Z.; Chocat, N.; Ruff, Z. M.; Stolyarov, A. M.; Shemuly, D.; Sorin, F.; Rakich, P. T.; Joannopoulos, J. D.; Fink, Y.

    2010-08-01

    Fibre materials span a broad range of applications ranging from simple textile yarns to complex modern fibre-optic communication systems. Throughout their history, a key premise has remained essentially unchanged: fibres are static devices, incapable of controllably changing their properties over a wide range of frequencies. A number of approaches to realizing time-dependent variations in fibres have emerged, including refractive index modulation, nonlinear optical mechanisms in silica glass fibres and electroactively modulated polymer fibres. These approaches have been limited primarily because of the inert nature of traditional glassy fibre materials. Here we report the composition of a phase internal to a composite fibre structure that is simultaneously crystalline and non-centrosymmetric. A ferroelectric polymer layer of 30μm thickness is spatially confined and electrically contacted by internal viscous electrodes and encapsulated in an insulating polymer cladding hundreds of micrometres in diameter. The structure is thermally drawn in its entirety from a macroscopic preform, yielding tens of metres of piezoelectric fibre. The fibres show a piezoelectric response and acoustic transduction from kilohertz to megahertz frequencies. A single-fibre electrically driven device containing a high-quality-factor Fabry-Perot optical resonator and a piezoelectric transducer is fabricated and measured.

  11. Consequences of detergent pollution of the sea: effects on regenerating sponge cubes of Geodia cydonium.

    PubMed

    Zahn, R K; Zahn, G; Müller, W E; Müller, I; Beyer, R; Müller-Berger, U; Kupelec, B; Rijavec, M; Britvić, S

    1977-09-01

    Regenerating cubes of the sponge Geodia cydonium cyconium were used as a model in the investigation of detergent pollution in the sea. The anionic detergent sodium dodecylsulphate (SDS) and a 1:1 mixture of Faks and Radion, two commercial laundry detergents, were used in the concentration range from 1 X 10(-9) g/ml (1 ppb) to 1 X 10(-5) g/ml. It is shown that SDS is taken up, weakly accumulated but not incorporated into the macromolecular fractions of the sponge. At concentrations of 0.1 ppm and above, SDS decreases the uptake of thymidine, uridine and phenylalanine into the acid-soluble sponge fraction. Their incorporation into the acid insoluble fractions, which have been isolated, was different from the controls at 10 ppb and higher levels. Faks and Radion were less active by a factor of 10. However, they showed similar effects. The chemical composition of the regenerating sponge cubes with respect to DNA, RNA and protein content has been evaluated. The alterations are less pronounced on detergent incubation than precursor uptake. The use of the cetyltrimethyl-ammoniumbromide-turbidity-dilution technique reveals drastic qualitative changes in the nucleic acid fractions. The relevant literature on biological effects of detergent is listed. It is shown that this investigation extends the scale of known effects far into the low and pollution-relevant concentration levels.

  12. Laundry detergent capsules and pediatric poisoning

    PubMed Central

    Bonney, Asha G.; Mazor, Suzan; Goldman, Ran D.

    2013-01-01

    Abstract Question A 4-year-old girl was brought into the emergency department vomiting after having had ingested a laundry detergent capsule (LDC) from under the sink at her house. What is the risk of LDC poisoning? What can be done to treat these children? Answer Laundry detergent capsules are relatively new to supermarket shelves in North America, and there has been an emergence of case reports in the literature describing LDC poisoning, which is worse than poisoning from other laundry detergents. Very little is known about the mechanisms causing these severe reactions, which include airway compromise and esophageal perforation, but the attractive appearance of these capsules and easy access at home has governments and health officials concerned about an increase in poisoning. No residual problems have been associated with these cases to date; however, further research is needed to assess long-term effects. PMID:24336541

  13. Enhancing Textile Fiber Identification with Detergent Fluorescence.

    PubMed

    Mujumdar, Nirvani; Heider, Emily C; Campiglia, Andres D

    2015-12-01

    Discovering common origins of trace evidential textile fibers can be a challenging task when fiber structure or dye composition does not provide exclusive identifying information. Introduction of new chemical species after mass production and distribution of a textile may be exploited to trace its history and identify the origin of its fibers. In this article, fluorescence microscopy is used to examine the alteration in the fluorescence spectral fingerprint of single fibers resulting from exposure to commonly used detergents that contain fluorescent whitening agents. Dyed acrylic, cotton, and nylon fibers were laundered and the spectral contribution of the detergent on single fibers was quantified and shown to reach a maximum after five sequential washes; some detergents showed statistically meaningful differences to fiber spectra after only a single wash. Principal component cluster analysis was used to determine that the spectra of laundered fibers are distinct from the spectra of dyed, unwashed cotton or nylon, but not acrylic, fibers. PMID:26647148

  14. CHOBIMALT: a cholesterol-based detergent.

    PubMed

    Howell, Stanley C; Mittal, Ritesh; Huang, Lijun; Travis, Benjamin; Breyer, Richard M; Sanders, Charles R

    2010-11-01

    Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address these problems, a cholesterol-based detergent, CHOBIMALT, has been synthesized and characterized. At concentrations above 3−4 μM, CHOBIMALT forms micelles without the need for elevated temperatures or sonic disruption. Diffusion and fluorescence measurements indicated that CHOBIMALT micelles are large (210±30 kDa). The ability to solubilize a functional membrane protein was explored using a G-protein coupled receptor, the human kappa opioid receptor type 1 (hKOR1). While CHOBIMALT alone was not found to be effective as a surfactant for membrane extraction, when added to classical detergent micelles CHOBIMALT was observed to dramatically enhance the thermal stability of solubilized hKOR1.

  15. Brij detergents reveal new aspects of membrane microdomain in erythrocytes.

    PubMed

    Casadei, Bruna Renata; De Oliveira Carvalho, Patrícia; Riske, Karin A; Barbosa, Raquel De Melo; De Paula, Eneida; Domingues, Cleyton Crepaldi

    2014-09-01

    Membrane microdomains enriched in cholesterol, sphingolipids (rafts), and specific proteins are involved in important physiological functions. However their structure, size and stability are still controversial. Given that detergent-resistant membranes (DRMs) are in the liquid-ordered state and are rich in raft-like components, they might correspond to rafts at least to some extent. Here we monitor the lateral order of biological membranes by characterizing DRMs from erythrocytes obtained with Brij-98, Brij-58, and TX-100 at 4 °C and 37 °C. All DRMs were enriched in cholesterol and contained the raft markers flotillin-2 and stomatin. However, sphingomyelin (SM) was only found to be enriched in TX-100-DRMs - a detergent that preferentially solubilizes the membrane inner leaflet - while Band 3 was present solely in Brij-DRMs. Electron paramagnetic resonance spectra showed that the acyl chain packing of Brij-DRMs was lower than TX-100-DRMs, providing evidence of their diverse lipid composition. Fatty acid analysis revealed that the SM fraction of the DRMs was enriched in lignoceric acid, which should specifically contribute to the resistance of SM to detergents. These results indicate that lipids from the outer leaflet, particularly SM, are essential for the formation of the liquid-ordered phase of DRMs. At last, the differential solubilization process induced by Brij-98 and TX-100 was monitored using giant unilamellar vesicles. This study suggests that Brij and TX-100-DRMs reflect different degrees of lateral order of the membrane microdomains. Additionally, Brij DRMs are composed by both inner and outer leaflet components, making them more physiologically relevant than TX-100-DRMs to the studies of membrane rafts.

  16. Therapeutic role of dietary fibre.

    PubMed Central

    Hunt, R.; Fedorak, R.; Frohlich, J.; McLennan, C.; Pavilanis, A.

    1993-01-01

    The current status of dietary fibre and fibre supplements in health and disease is reported, and the components of dietary fibre and its respective mechanical and metabolic effects with emphasis on its therapeutic potential are reviewed. Practical management guidelines are provided to help physicians encourage patients identified as having fibre deficiency to increase dietary fibre intake to the recommended level. PMID:8388284

  17. Fibre optics: Forty years later

    SciTech Connect

    Dianov, Evgenii M

    2010-01-31

    This paper presents a brief overview of the state of the art in fibre optics and its main applications: optical fibre communications, fibre lasers and fibre sensors for various physical property measurements. The future of fibre optics and the status of this important area of the modern technology in Russia are discussed. (fiber optics)

  18. Ingestion of Laundry Detergent Packets in Children.

    PubMed

    Shah, Lindsey Wilson

    2016-08-01

    Ingestion of laundry detergent packets is an important threat to young children. Because of their developmental stage, toddlers are prone to place these small, colorful packets in their mouths. The packets can easily burst, sending a large volume of viscous, alkaline liquid throughout the oropharynx. Ingestion causes major toxic effects, including depression of the central nervous system, metabolic acidosis, respiratory distress, and dysphagia. Critical care nurses should anticipate these clinical effects and facilitate prompt intervention. Increased understanding of the risks and clinical effects of ingestion of laundry detergent packets will better prepare critical care nurses to provide care for these children. (Critical Care Nurse 2016; 36[4]:70-75).

  19. Ingestion of Laundry Detergent Packets in Children.

    PubMed

    Shah, Lindsey Wilson

    2016-08-01

    Ingestion of laundry detergent packets is an important threat to young children. Because of their developmental stage, toddlers are prone to place these small, colorful packets in their mouths. The packets can easily burst, sending a large volume of viscous, alkaline liquid throughout the oropharynx. Ingestion causes major toxic effects, including depression of the central nervous system, metabolic acidosis, respiratory distress, and dysphagia. Critical care nurses should anticipate these clinical effects and facilitate prompt intervention. Increased understanding of the risks and clinical effects of ingestion of laundry detergent packets will better prepare critical care nurses to provide care for these children. (Critical Care Nurse 2016; 36[4]:70-75). PMID:27481804

  20. HIPPI and Fibre Channel

    SciTech Connect

    Tolmie, D.E.

    1992-01-01

    The High-Performance Parallel Interface (HIPPI) and Fibre Channel are near-gigabit per second data communications interfaces being developed in ANSI standards Task Group X3T9.3. HIPPI is the current interface of choice in the high-end and supercomputer arena, and Fibre Channel is a follow-on effort. HIPPI came from a local area network background, and Fibre Channel came from a mainframe to peripheral interface background.

  1. Coproduction of detergent compatible bacterial enzymes and stain removal evaluation.

    PubMed

    Niyonzima, Francois N; More, Sunil S

    2015-10-01

    Most of the detergents that are presently produced contain the detergent compatible enzymes to improve and accelerate the washing performance by removing tough stains. The process is environment friendly as the use of enzymes in the detergent formulation reduces the utilization of toxic detergent constituents. The current trend is to use the detergent compatible enzymes that are active at low and ambient temperature in order to save energy and maintain fabric quality. As the detergent compatible bacterial enzymes are used together in the detergent formulation, it is important to co-produce the detergent enzymes in a single fermentation medium as the enzyme stability is assured, and production cost gets reduced enormously. The review reports on the production, purification, characterization and application of detergent compatible amylases, lipases, and proteases are available. However, there is no specific review or minireview on the concomitant production of detergent compatible amylases, lipases, and proteases. In this minireview, the coproduction of detergent compatible enzymes by bacterial species, enzyme stability towards detergents and detergent components, and stain release analysis were discussed.

  2. Movement and fate of detergents in groundwater: a field study

    USGS Publications Warehouse

    Thurman, E.M.; Barber, L.B.; LeBlanc, D.

    1986-01-01

    The major cations, anions, and detergents in a plume of contaminated groundwater at Otis Air Base on Cape Cod (Mass., U.S.A.) have moved approximately 3.5 km down gradient from the disposal beds. We hypothesize that the detergents form two distinct plumes, which consist of alkyl benzene sulfonates (ABS) detergents and linear alkyl sulfonates (LAS) and sodium dodecyl sulfate (NaLS) detergents. The ABS detergents were deposited from approximately 1940 through 1965, when ABS detergents were banned. From 1965 to the present, LAS and NaLS detergents were in the sewage. The ABS detergents appear to be transported in the aquifer at the same rate as the specific conductance (major cations and anions) and boron, which are currently used as conservative tracers of the plume of contaminated groundwater. There appears to be little or no biological degradation of the ABS detergents in the aquifer, based on their concentration in the plume. On the other hand, the LAS and NaLS detergents have degraded rapidly and have been detected only 0.6 km down gradient. The roleof the detergents in the transport of other organic compounds in the plume is nuclear. There is a separation of the ABS detergent plume and the volatile organic compound plume; however, the time of entry of the detergents and the volatile organic compounds is unknown. Therefore, it is not possible to conclude on the interaction of these two classes of compounds. ?? 1986.

  3. Detergency stability and particle characterization of phosphate-free spray dried detergent powders incorporated with palm C16 methyl ester sulfonate (C16MES).

    PubMed

    Siwayanan, Parthiban; Aziz, Ramlan; Bakar, Nooh Abu; Ya, Hamdan; Jokiman, Ropien; Chelliapan, Shreeshivadasan

    2014-01-01

    Phosphate-free spray dried detergent powders (SDDP) comprising binary anionic surfactants of palm C16 methyl ester sulfonate (C16MES) and linear alkyl benzene sulfonic acid (LABSA) were produced using a 5 kg/h-capacity co-current pilot spray dryer (CSD). Six phosphate-free detergent (PFD) formulations comprising C16MES/LABSA in various ratios under pH 7-8 were studied. Three PFD formulations having C16MES/LABSA in respective ratios of 0:100 (control), 20:80 and 40:60 ratios were selected for further evaluation based on their optimum detergent slurry concentrations. The resulting SDDP from these formulations were analysed for its detergency stability (over nine months of storage period) and particle characteristics. C16MES/LABSA of 40:60 ratio was selected as the ideal PFD formulation since its resulting SDDP has consistent detergency stability (variation of 2.3% in detergency/active over nine months storage period), excellent bulk density (0.37 kg/L), fine particle size at 50% cumulative volume percentage (D50 of 60.48 μm), high coefficient of particle size uniformity (D60/D10 of 3.86) and large spread of equivalent particle diameters. In terms of surface morphology, the SDDP of the ideal formulation were found to have regular hollow particles with smooth spherical surfaces. Although SDDP of the ideal formulation have excellent characteristics, but in terms of flowability, these powders were classified as slightly less free flowing (Hausner ratio of 1.27 and Carr's index of 21.3).

  4. Differential detergent sensitivity of extracellular vesicle subpopulations.

    PubMed

    Osteikoetxea, Xabier; Sódar, Barbara; Németh, Andrea; Szabó-Taylor, Katalin; Pálóczi, Krisztina; Vukman, Krisztina V; Tamási, Viola; Balogh, Andrea; Kittel, Ágnes; Pállinger, Éva; Buzás, Edit Irén

    2015-10-14

    Extracellular vesicles (including exosomes, microvesicles and apoptotic bodies) are currently attracting rapidly increasing attention from various fields of biology due to their ability to carry complex information and act as autocrine, paracrine and even endocrine intercellular messengers. In the present study we investigated the sensitivity of size-based subpopulations of extracellular vesicles to different concentrations of detergents including sodium dodecyl sulphate, Triton X-100, Tween 20 and deoxycholate. We determined the required detergent concentration that lysed each of the vesicle subpopulations secreted by Jurkat, THP-1, MiaPaCa and U937 human cell lines. We characterized the vesicles by tunable resistive pulse sensing, flow cytometry and transmission electron microscopy. Microvesicles and apoptotic bodies were found to be more sensitive to detergent lysis than exosomes. Furthermore, we found evidence that sodium dodecyl sulphate and Triton X-100 were more effective in vesicle lysis at low concentrations than deoxycholate or Tween 20. Taken together, our data suggest that a combination of differential detergent lysis with tunable resistive pulse sensing or flow cytometry may prove useful for simple and fast differentiation between exosomes and other extracellular vesicle subpopulations as well as between vesicular and non-vesicular structures.

  5. Diesel fuel detergent additive performance and assessment

    SciTech Connect

    Vincent, M.W.; Papachristos, M.J.; Williams, D.; Burton, J.

    1994-10-01

    Diesel fuel detergent additives are increasingly linked with high quality automotive diesel fuels. Both in Europe and in the USA, field problems associated with fuel injector coking or fouling have been experienced. In Europe indirect injection (IDI) light duty engines used in passenger cars were affected, while in the USA, a direct injection (DI) engine in heavy duty truck applications experienced field problems. In both cases, a fuel additive detergent performance test has evolved using an engine linked with the original field problem, although engine design modifications employed by the manufacturers have ensured improved operation in service. Increasing awareness of the potential for injector nozzle coking to cause deterioration in engine performance is coupled with a need to meet ever more stringent exhaust emissions legislation. These two requirements indicate that the use of detergency additives will continue to be associated with high quality diesel fuels. The paper examines detergency performance evaluated in a range of IDI and DI engines and correlates performance in the two most widely recognised test engines, namely the Peugeot 1.9 litre IDI, and Cummins L10 DI engines. 17 refs., 18 figs., 5 tabs.

  6. Laundry detergent and possible nonaccidental injury.

    PubMed

    Howieson, Alan J; Harley, Oliver J H; Tiernan, Eunan P

    2007-06-01

    Nonaccidental injury is always a concern when children present with unusual injuries. The case of a child who presented with a partial thickness burn secondary to prolonged contact with a liquid biological laundry detergent is described. Initially there was some doubt as to whether the agent in question could cause this injury but a small experiment on a volunteer confirmed it was possible.

  7. An in vitro cytotoxicity test to predict the ocular irritation potential of detergents and detergent products.

    PubMed

    Scaife, M C

    1985-02-01

    Two in vitro cytotoxicity procedures, the measurement of cell-membrane integrity using fluorescein diacetate and ethidium bromide, and the quantitation of the release of a cell-membrane-bound enzyme, alkaline phosphatase, were used to assess the cytotoxicity of a range of cationic, anionic and nonionic detergents. The in vitro results were compared with the in vivo irritancy of these compounds in the rabbit eye. Although in general the decreasing order of potency of cationic, anionic and nonionic detergents was similar in vivo and in vitro, there were some apparent anomalies which may be due to the differing penetration characteristics of the detergents, as indicated by electrical impedance measurements of the isolated cornea. The study was extended to an examination of the cytotoxicity of a range of completely soluble, detergent-based formulations in a suspension culture of mouse fibroblasts. In this case the in vitro results correlated more closely with those from the in vivo tests.

  8. Spider silk: a novel optical fibre for biochemical sensing

    NASA Astrophysics Data System (ADS)

    Hey Tow, Kenny; Chow, Desmond M.; Vollrath, Fritz; Dicaire, Isabelle; Gheysens, Tom; Thévenaz, Luc

    2015-09-01

    Whilst being thoroughly used in the textile industry and biomedical sector, silk has not yet been exploited for fibre optics-based sensing although silk fibres directly obtained from spiders can guide light and have shown early promises to being sensitive to some solvents. In this communication, a pioneering optical fibre sensor based on spider silk is reported, demonstrating for the first time the use of spider silk as an optical fibre sensor to detect polar solvents such as water, ammonia and acetic acid.

  9. In vitro bacterial fermentation of tropical fruit fibres.

    PubMed

    Vong, M H; Stewart, M L

    2013-09-01

    Tropical fruits such as mango, papaya, pineapple and banana are rich sources of dietary fibre. However, few studies have examined the potential physiological effects of fibre from these tropical fruits. The aim of this study was to characterise the fermentability of dietary fibre found in banana, papaya, pineapple and mango as an estimate of the physiological effects of consuming these fruits. Freeze-dried fruit was subjected to in vitro digestion to remove digestible carbohydrates. Digestion residues were freeze-dried prior to fermentation. In vitro fermentation was carried for 24 h under anaerobic conditions to simulate conditions in the large intestine. Gas volume, pH and short chain fatty acids (SCFAs) concentration were measured at 0, 4, 8, 12, and 24 h. SCFAs were analysed by gas chromatography. There was no gas production from 0 to 8 h time points for all samples. Mango fibre resulted in more gas at 12 and 24 h than pineapple, papaya and banana fibres. The slurry pH was significantly lower for mango fibre at 12 and 24 h compared to other samples. Mango fibre resulted in significantly more propionate at 8 h compared to papaya and pineapple fibres. Butyrate concentrations were only significantly different at 4 h. At 24 h total and individual SCFA production did not differ among samples. All fruit fibres were fermentable, with mango fibre being the most rapidly fermented. Additional work is necessary to confirm a benefit on digestive health.

  10. 40 CFR 80.163 - Detergent certification options.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... certification test fuel shall contain an oxygenate compound other than ethanol. A detergent certified under this...), the certification test fuel shall contain an oxygenate compound other than ethanol. A detergent... certification test fuel shall contain no ethanol or other oxygenate. A detergent certified under this...

  11. Sublethal detergent concentrations increase metabolization of recalcitrant polyphosphonates by the cyanobacterium Spirulina platensis.

    PubMed

    Forlani, Giuseppe; Bertazzini, Michele; Giberti, Samuele; Wieczorek, Dorota; Kafarski, Paweł; Lipok, Jacek

    2013-05-01

    As a consequence of increasing industrial applications, thousand tons of polyphosphonates are introduced every year into the environment. The inherent stability of the C-P bond results in a prolonged half-life. Moreover, low uptake rates limit further their microbial metabolization. To assess whether low detergent concentrations were able to increase polyphosphonate utilization by the cyanobacterium Spirulina platensis, tolerance limits to the exposure to various detergents were determined by measuring the growth rate in the presence of graded levels below the critical micellar concentration. Then, the amount of hexamethylenediamine-N,N,N',N'-tetrakis(methylphosphonic acid) that is metabolized in the absence or in the presence of sublethal detergent concentrations was quantified by (31)P NMR analysis on either P-starved or P-fed cyanobacterial cultures. The strain tolerated the presence of detergents in the order: nonionic > anionic > cationic. When added to the culture medium at the highest concentrations showing no detrimental effects upon cell viability, detergents either improved or decreased polyphosphonate utilization, the anionic sodium dodecyl sulfate being the most beneficial. Metabolization was not lower in P-fed cells--a result that strengthens the possibility of using, in the future, this strain for bioremediation purposes. PMID:23089958

  12. Modified detergent Ziehl-Neelsen technique for the staining of Cyclospora cayetanensis.

    PubMed Central

    Clarke, S C; McIntyre, M

    1996-01-01

    Cyclospora cayetanensis is a cause of prolonged diarrhoea, mainly in travellers. Laboratory diagnosis may be achieved by a number of methods such as the staining of faecal smears by the modified Ziehl-Neelsen (ZN) technique. Safer methods using this technique have been described for the staining of acid fast bacilli and cryptosporidia by replacing the phenol content of the carbol fuschin stain with various concentrated detergents. In this report the technique was modified slightly using a non-concentrated detergent and applied to the staining of oocysts of C cayetanensis. It was found that oocysts of C cayetanensis do not stain using the modified detergent ZN method when compared with similar preparations containing oocysts of Cryptosporidium spp. PMID:8763270

  13. Dietary fibre analysis.

    PubMed

    McCleary, Barry V

    2003-02-01

    The 'gold standard' method for the measurement of total dietary fibre is that of the Association of Official Analytical Chemists (2000; method 985.29). This procedure has been modified to allow measurement of soluble and insoluble dietary fibre, and buffers employed have been improved. However, the recognition of the fact that non-digestible oligosaccharides and resistant starch also behave physiologically as dietary fibre has necessitated a re-examination of the definition of dietary fibre, and in turn, a re-evaluation of the dietary fibre methods of the Association of Official Analytical Chemists. With this realisation, the American Association of Cereal Chemists appointed a scientific review committee and charged it with the task of reviewing and, if necessary, updating the definition of dietary fibre. It organised various workshops and accepted comments from interested parties worldwide through an interactive website. More recently, the (US) Food and Nutrition Board of the Institute of Health, National Academy of Sciences, under the oversight of the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes, assembled a panel to develop a proposed definition(s) of dietary fibre. Various elements of these definitions were in agreement, but not all. What was clear from both reviews is that there is an immediate need to re-evaluate the methods that are used for dietary fibre measurement and to make appropriate changes where required, and to find new methods to fill gaps. In this presentation, the 'state of the art' in measurement of total dietary fibre and dietary fibre components will be described and discussed, together with suggestions for future research. PMID:12740050

  14. Enhanced gene delivery to the lung using biodegradable polyunsaturated cationic phosphatidylcholine-detergent conjugates.

    PubMed

    Pierrat, Philippe; Kereselidze, Dimitri; Lux, Marie; Lebeau, Luc; Pons, Françoise

    2016-09-10

    Lung diseases are among the more representative causes of mortality and morbidity worldwide and gene therapy is considered as a promising therapeutic approach for their treatment. However the design of efficient nucleic acid carriers for airway administration still is a challenge and there is a pressing need for new developments in this field. Herein, new synthetic DNA carriers based on the conjugation of a phospholipid and C12E4, a nonionic detergent, are developed. DNA complexes with phosphatidylcholine-detergent conjugates are administered in mouse airways, and transgene expression and inflammatory activity as an index of toxicity are investigated as a function of time, DNA dose, and presence of helper and stealth lipids. Introduction of a biodegradable linker between the phosphatidylcholine and detergent moieties significantly attenuates the severity of inflammatory response that characterizes cationic lipid-mediated gene transfer. Concurrent introduction of polyunsaturated fatty acid chains in the carrier scaffold improves transgene expression and further reduces airway inflammation. Finally, the biodegradable phosphatidylcholine-detergent conjugates favorably compare to GL67A, the gold standard for DNA delivery to the airway that is currently under clinical evaluation. Our findings indicate that the lipid formulations described herein may have great potential as nucleic acid carriers for gene therapy. PMID:27418568

  15. Enhanced gene delivery to the lung using biodegradable polyunsaturated cationic phosphatidylcholine-detergent conjugates.

    PubMed

    Pierrat, Philippe; Kereselidze, Dimitri; Lux, Marie; Lebeau, Luc; Pons, Françoise

    2016-09-10

    Lung diseases are among the more representative causes of mortality and morbidity worldwide and gene therapy is considered as a promising therapeutic approach for their treatment. However the design of efficient nucleic acid carriers for airway administration still is a challenge and there is a pressing need for new developments in this field. Herein, new synthetic DNA carriers based on the conjugation of a phospholipid and C12E4, a nonionic detergent, are developed. DNA complexes with phosphatidylcholine-detergent conjugates are administered in mouse airways, and transgene expression and inflammatory activity as an index of toxicity are investigated as a function of time, DNA dose, and presence of helper and stealth lipids. Introduction of a biodegradable linker between the phosphatidylcholine and detergent moieties significantly attenuates the severity of inflammatory response that characterizes cationic lipid-mediated gene transfer. Concurrent introduction of polyunsaturated fatty acid chains in the carrier scaffold improves transgene expression and further reduces airway inflammation. Finally, the biodegradable phosphatidylcholine-detergent conjugates favorably compare to GL67A, the gold standard for DNA delivery to the airway that is currently under clinical evaluation. Our findings indicate that the lipid formulations described herein may have great potential as nucleic acid carriers for gene therapy.

  16. The Physico-Chemical Properties of Dietary Fibre Determine Metabolic Responses, Short-Chain Fatty Acid Profiles and Gut Microbiota Composition in Rats Fed Low- and High-Fat Diets

    PubMed Central

    Kulcinskaja, Evelina; Marungruang, Nittaya; Matziouridou, Chrysoula; Nilsson, Ulf; Stålbrand, Henrik; Nyman, Margareta

    2015-01-01

    The aim of this study was to investigate how physico-chemical properties of two dietary fibres, guar gum and pectin, affected weight gain, adiposity, lipid metabolism, short-chain fatty acid (SCFA) profiles and the gut microbiota in male Wistar rats fed either low- or high-fat diets for three weeks. Both pectin and guar gum reduced weight gain, adiposity, liver fat and blood glucose levels in rats fed a high-fat diet. Methoxylation degree of pectin (low, LM and high (HM)) and viscosity of guar gum (low, medium or high) resulted in different effects in the rats, where total blood and caecal amounts of SCFA were increased with guar gum (all viscosities) and with high methoxylated (HM) pectin. However, only guar gum with medium and high viscosity increased the levels of butyric acid in caecum and blood. Both pectin and guar gum reduced cholesterol, liver steatosis and blood glucose levels, but to varying extent depending on the degree of methoxylation and viscosity of the fibres. The medium viscosity guar gum was the most effective preparation for prevention of diet-induced hyperlipidaemia and liver steatosis. Caecal abundance of Akkermansia was increased with high-fat feeding and with HM pectin and guar gum of all viscosities tested. Moreover, guar gum had distinct bifidogenic effects independent of viscosity, increasing the caecal abundance of Bifidobacterium ten-fold. In conclusion, by tailoring the viscosity and possibly also the degree of methoxylation of dietary fibre, metabolic effects may be optimized, through a targeted modulation of the gut microbiota and its metabolites. PMID:25973610

  17. Toxicity of laundry detergent components to a freshwater cladoceran and their contribution to detergent toxicity.

    PubMed

    Warne, M S; Schifko, A D

    1999-10-01

    The toxicity of 39 laundry detergent components including surfactants, enzymes, builders, fabric brighteners, fillers, and coloring agents to the cladoceran Ceriodaphnia cf. dubia was determined. The difference between the most and the least toxic components was approximately 17,000-fold and 1,000,000-fold for the mg/L and mmol/L EC50 data, respectively. Two of the components had high toxicity (EC50 values < 1 mg/L), 11 moderate toxicity (EC50 values between 1 and 10 mg/L), and the remaining 26 components had low toxicity (EC50 values > 10 mg/L). Analysis revealed that mixtures of the components interacted antagonistically, additively, and synergistically. On a molarity basis the most toxic group of compounds was the surfactants followed by the brighteners. The most toxic individual components included sodium carboxymethyl cellulose, sodium silicate solution, four brighteners, sodium perborate tetrahydrate, and the surfactants. Many of the most toxic components, however, contributed very little to the toxicity of the detergents due to being present in the detergents at low concentrations. The main contributors to the toxicity of detergents were the sodium silicate solution and the surfactants-with the remainder of the components contributing very little to detergent toxicity. The potential for acute aquatic toxic effects due to the release of secondary or tertiary sewage effluents containing the breakdown products of laundry detergents may frequently be low. However, untreated or primary treated effluents containing detergents may pose a problem. Chronic and/or other sublethal effects that were not examined in this study may also pose a problem.

  18. Solubilization of glycoproteins of envelope viruses by detergents

    SciTech Connect

    Berezin, V.E.; Zaides, V.M.; Artamsnov, A.F.; Isaeva, E.S.; Zhdanov, V.M.

    1986-11-20

    The action of a number of known ionic and nonionic detergents, as well as the new nonionic detergent MESK, on envelope viruses was investigated. It was shown that the nonionic detergents MESK, Triton X-100, and octyl-..beta..-D-glucopyranoside selectively solubilize the outer glycoproteins of the virus particles. The nonionic detergent MESK has the mildest action. Using MESK, purified glycoproteins of influenza, parainfluenza, Venezuelan equine encephalomyelitis, vesicular stomatitis, rabies, and herpes viruses were obtained. The procedure for obtaining glycoproteins includes incubation of the virus suspension with the detergent MESK, removal of subvirus structures by centrifuging, and purification of glycoproteins from detergents by dialysis. Isolated glycoproteins retain a native structure and biological activity and possess high immunogenicity. The detergent MESK is promising for laboratory tests and with respect to the production of subunit vaccines.

  19. Novel detergent for whole organ tissue engineering.

    PubMed

    Kawasaki, Takanori; Kirita, Yuhei; Kami, Daisuke; Kitani, Tomoya; Ozaki, Chisa; Itakura, Yoko; Toyoda, Masashi; Gojo, Satoshi

    2015-10-01

    Whole organ tissue engineering for various organs, including the heart, lung, liver, and kidney, has demonstrated promising results for end-stage organ failure. However, the sodium dodecyl sulfate (SDS)-based protocol for standard decellularization has drawbacks such as clot formation in vascularized transplantation and poor cell engraftment in recellularization procedures. Preservation of the surface milieu of extracellular matrices (ECMs) might be crucial for organ generation based on decellularization/recellularization engineering. We examined a novel detergent, sodium lauryl ether sulfate (SLES), to determine whether it could overcome the drawbacks associated with SDS using rat heart and kidney. Both organs were perfused in an antegrade fashion with either SLES or SDS. Although immunohistochemistry for collagen I, IV, laminin, and fibronectin showed similar preservation in both detergents, morphological analysis using scanning electron microscopy and an assay of glycosaminoglycan content on ECMs showed that SLES-treated tissues had better-preserved ECMs than SDS-treated tissues. Mesenteric transplantation revealed SLES did not induce significant inflammation, as opposed to SDS. Platelet adhesion to decellularized tissues was significantly reduced with SLES. Overall, SLES could replace older detergents such as SDS in the decellularization process for generation of transplantable recellularized organs.

  20. [Determination of the detergent efficiency of the detergents disinfecting for surfaces].

    PubMed

    Santucci, R; Kuntzmann, X; Mesli, N; Meunier, O

    2009-01-01

    Since the disinfecting activity of disinfectants is evaluated by standards, the intrinsic detergent activity is not easily quantifiable and no standard have been suggested yet. Beyond the physicochemical parameters like wettability or foaming presented by the manufacturers, it appears necessary to us to objectively measure the real effect of the detergent agent. The objective of our work is to propose a simple, fast and reproducible method to evaluate detersive activity of the disinfecting detergents. We measured three factors (total amount of extracted bacteria, extraction efficiency and slope of extracting curve) by using Rodac prints technique on two different supports (PVC, stainless steel) that have been contaminated by either E. coli or S. aureus. An increasing mark from 1 to 6 is given to each of these factors in case of statistically differences. The three factors allowed us to calculate a "Specific Index of detersion" (SI) for each germ/support couple (3 to 18). Addition of the marks given to each couple for each disinfecting detergent allowed to calculate a "Globally Index of detersion" (GI) (9 to 72). We tested 4 commercialised disinfecting detergents: Surfanios, Aniosurf, Major C100 and Ecodiol. All detergents may be classified according to their effectiveness on a bacterium/support couple (value of the SI). This enlights a specific spectrum for each disinfecting detergents. As a result, Ecodiol seems to be the most effective deterging agent on 3 of the 4 germ/support couples (S. aureus/PVC, E. coli/PVC and E. coli/stainless steel), whereas Aniosurf is most effective on the S. aureus/stainless steel couple. The GI is very useful to choose the best compromise between activities for all situations. GI rankings of the tested agents were as follows: water < Aniosurf < Surfanios < neutralizing < Major C100 < Ecodiol. This experimental model will be used to test and compare the intrinsic detergent activities of other commercialised products which are usually

  1. Giant muscle fibres in pigs with different Ryr1 genotype.

    PubMed

    Fazarinc, G; Candek-Potokar, M; Ursic, M; Vrecl, M; Pogacnik, A

    2002-12-01

    This study examined the frequency, morphological and immunohistochemical characteristics of the giant fibres in the longissimus muscle of local Krsko polje pigs with different Ryr1 genotypes. Giant fibres were round-shaped and had significantly increased cross-sectional area compared with normal muscle fibres. Only fast-twitch glycolytic fibres were affected, usually showing enhanced succinate dehydrogenase activity. On the ultrastructural level, the dilation of the sarcoplasmic reticulum, swelling of mitochondria and destruction of myofilaments was observed. The incidence of giant fibres was the highest in Ryr1 dimutant pigs (Ryr1 nn), which also exhibited lower muscle pH1 than heterozygous (Ryr1 Nn) or pigs with the wild Ryr1 gene (Ryr1 NN). However, the giant fibres were also present in pigs free of Ryr1 gene mutation. Our results suggest that the giant fibre syndrome depends mostly upon the rate and intensity of early post-mortem glycolysis, which results in acidity of muscle tissue. We suppose that the giant fibre formation is a result of excessive intracellular lactate accumulation in some fast-twitch glycolytic fibres. This process could also explain the ultrastructural alterations and the consequent changes in the oxidative enzymes and myofibrillar ATPase staining pattern observed in our and some previous studies.

  2. Optical Fibre Switch

    NASA Astrophysics Data System (ADS)

    Markatos, S.; Ayres, S.; Kreit, D.; Kerr, A.; Youngquist, R. C.; Giles, I. P.

    1987-10-01

    The design construction and operation of a thermally controlled optical fibre switch, based upon the lap/polish technique, is described in this paper. The lap/polish method allows access to the evanescent field in an optical fibre and coupling between two fibres can be controlled from zero to total power transfer by changing the refractive index of the oil in the coupling region. Such refractive index changes can be induced thermally by directly heating the matching oil at the interaction area, with forming heating elements close to the fibre core. Power coupling is then proportional to the current supplied to the electrodes. Results are presented showing the frequency response of tlio device.

  3. Fibres get functional

    NASA Astrophysics Data System (ADS)

    Graham-Rowe, Duncan

    2011-02-01

    New forms of advanced optical fibres featuring exotic glasses, carefully designed microstructures and cores that are either hollow, fluidic, semiconductor or piezoelectric are giving light guides a new lease of life, reports Duncan Graham-Rowe.

  4. Enzymatic detergent formulation containing amylase from Aspergillus niger: a comparative study with commercial detergent formulations.

    PubMed

    Mitidieri, Sydnei; Souza Martinelli, Anne Helene; Schrank, Augusto; Vainstein, Marilene Henning

    2006-07-01

    There is a wide range of biotechnological applications for amylases, including the textile, pharmaceutical, food and laundry industries. Hydrolytic enzymes are 100% biodegradable and enzymatic detergents can achieve effective cleaning with lukewarm water. Microorganisms and culture media were tested for amylase production and the best producer was Aspergillus niger L119 (3.9 U ml(-1) +/- 0.2) in submerged culture and its amylase demonstrated excellent activity at 50-55 degrees C and pH 4.0, remaining stable at 53 degrees C for up to 200 h. In order to establish the potential uses of this enzyme in detergents, different formulations were tested using the A. niger amylase extract. Enzyme activity was compared with three commercial formulations. The detergents are used in hospitals to clean surgical and endoscopy equipment. The presence of amylase in the formulation is because of its action within hospital drainage system, whether or not it has any function in cleaning the equipment.

  5. The mechanism of detergent solubilization of lipid bilayers.

    PubMed

    Lichtenberg, Dov; Ahyayauch, Hasna; Goñi, Félix M

    2013-07-16

    Multiple data are available on the self-assembly of mixtures of bilayer-forming amphiphiles, particularly phospholipids and micelle-forming amphiphiles, commonly denoted detergents. The structure of such mixed assemblies has been thoroughly investigated, described in phase diagrams, and theoretically rationalized in terms of the balance between the large spontaneous curvature of the curvophilic detergent and the curvophobic phospholipids. In this critical review, we discuss the mechanism of this process and try to explain the actual mechanism involved in solubilization. Interestingly, membrane solubilization by some detergents is relatively slow and the common attribute of these detergents is that their trans-bilayer movement, commonly denoted flip-flop, is very slow. Only detergents that can flip into the inner monolayer cause relatively rapid solubilization of detergent-saturated bilayers. This occurs via the following sequence of events: 1), relatively rapid penetration of detergent monomers into the outer monolayer; 2), trans-membrane equilibration of detergent monomers between the two monolayers; 3), saturation of the bilayer by detergents and consequent permeabilization of the membrane; and 4), transition of the whole bilayer to thread-like mixed micelles. When the detergent cannot flip to the inner monolayer, the outer monolayer becomes unstable due to mass imbalance between the monolayers and inclusion of the curvophilic detergent molecules in a flat surface. Consequently, the outer monolayer forms mixed micellar structures within the outer monolayer. Shedding of these micelles into the aqueous solution results in partial solubilization. The consequent leakage of detergent into the liposome results in trans-membrane equilibration of detergent and subsequent micellization through the rapid bilayer-saturation mechanism.

  6. Effect of the Ratio of Non-fibrous Carbohydrates to Neutral Detergent Fiber and Protein Structure on Intake, Digestibility, Rumen Fermentation, and Nitrogen Metabolism in Lambs

    PubMed Central

    Ma, T.; Tu, Y.; Zhang, N. F.; Deng, K. D.; Diao, Q. Y.

    2015-01-01

    This study aimed to investigate the effect of the ratio of non-fibrous carbohydrates to neutral detergent fibre (NFC/NDF) and undegraded dietary protein (UDP) on rumen fermentation and nitrogen metabolism in lambs. Four Dorper×thin-tailed Han crossbred lambs, averaging 62.3±1.9 kg of body weight and 10 mo of age, were randomly assigned to four dietary treatments of combinations of two levels of NFC/NDF (1.0 and 1.7) and two levels of UDP (35% and 50% of crude protein [CP]). Duodenal nutrient flows were measured with dual markers of Yb and Co, and microbial N (MN) synthesis was estimated using 15N. High UDP decreased organic matter (OM) intake (p = 0.002) and CP intake (p = 0.005). Ruminal pH (p<0.001), ammonia nitrogen (NH3-N; p = 0.008), and total volatile fatty acids (p<0.001) were affected by dietary NFC/NDF. The ruminal concentration of NH3-N was also affected by UDP (p<0.001). The duodenal flow of total MN (p = 0.007) was greater for lambs fed the high NFC/NDF diet. The amount of metabolisable N increased with increasing dietary NFC:NDF (p = 0.02) or UDP (p = 0.04). In conclusion, the diets with high NFC/NDF (1.7) and UDP (50% of CP) improved metabolisable N supply to lambs. PMID:26323398

  7. A new high-performance thin layer chromatography-based assay of detergents and surfactants commonly used in membrane protein studies.

    PubMed

    Barret, Laurie-Anne; Polidori, Ange; Bonneté, Françoise; Bernard-Savary, Pierre; Jungas, Colette

    2013-03-15

    The hydrophobic nature of membrane proteins (MPs) necessitates the use of detergents for their extraction, solubilization and purification. Because the concentration of amphiphiles is crucial in the crystallization process, detergent quantification is essential to routine analysis. Here we describe a quantitative high-performance thin-layer chromatography (HPTLC) method we developed for the detection of small quantities of detergent bound to solubilized MPs. After optimization of aqueous deposit conditions, we show that most detergents widely used in membrane protein crystallography display distinctive mobilities in a mixture of dichloromethane, methanol and acetic acid 32:7.6:0.4 (v/v/v). Migration and derivatization conditions were optimized with n-dodecyl-β-D-maltoside (DDM), the most popular detergent for membrane protein crystallization. A linear calibration curve very well fits our data from 0.1 to 1.6 μg of DDM in water with a limit of detection of 0.05 μg. This limit of detection is the best achieved to date for a routine detergent assay, being not modified by the addition of NaCl, commonly used in protein buffers. With these chromatographic conditions, no prior treatment is required to assess the quantities of detergent bound to purified MPs, thus enabling the quantification of close structure detergents via a single procedure. This HPTLC method, which is fast and requires low sample volume, is fully suitable for routine measurements.

  8. Highly efficient cladding-pumped fibre laser based on an ytterbium-doped optical fibre and a fibre Bragg grating

    SciTech Connect

    Kurkov, Andrei S; Karpov, V I; Medvedkov, O I; Dianov, Evgenii M; Vasil'ev, Sergei A; Paramonov, Vladimir M; Protopopov, V N; Laptev, A Yu; Gur'yanov, A N; Umnikov, A A; Vechkanov, N I; Artyushenko, V G; Frahm, J

    1999-06-30

    Ytterbium-ion-doped double-clad optical fibres were developed. The differential quantum efficiency of a diode-pumped fibre laser, fabricated on the basis of such optical fibres with a fibre Bragg grating, was 90%. (lasers)

  9. The Use of Detergents to Purify Membrane Proteins.

    PubMed

    Orwick-Rydmark, Marcella; Arnold, Thomas; Linke, Dirk

    2016-04-01

    Extraction of membrane proteins from biological membranes is usually accomplished with the help of detergents. This unit describes the use of detergents to solubilize and purify membrane proteins. The chemical and physical properties of the different classes of detergents typically used with biological samples are discussed. A separate section addresses the compatibility of detergents with applications downstream of the membrane protein purification process, such as optical spectroscopy, mass spectrometry, protein crystallography, biomolecular NMR, or electron microscopy. A brief summary of alternative membrane protein solubilizing and stabilizing systems is also included. Protocols in this unit include the isolation and solubilization of biological membranes and phase separation; support protocols for detergent removal, detergent exchange, and the determination of critical micelle concentration using different methods are also included.

  10. Subchronic percutaneous toxicity testing of two liquid hand dishwashing detergents.

    PubMed

    Petersen, D W

    1988-09-01

    Subchronic percutaneous toxicity studies were conducted on two liquid dishwashing detergents containing anionic surfactants (C12-14 alkylethoxylate sulphate) to assess the safety of these materials for human exposure. The detergents were administered dermally to the shaved backs of rabbits (dose volume of 2 ml/kg body weight) at concentrations of 0, 0.5, 1.0 and 2.5% in distilled water for 91 days. No adverse systemic effects were demonstrated by assessment of haematological parameters or by gross or microscopic tissue examination. Transient slight to moderate dermal irritation at the detergent application site was observed with detergent A. Slight to moderate dermal irritation confined to the detergent application site was noted in the detergent B study.

  11. Toxicity following laundry detergent pod ingestion.

    PubMed

    Schneir, Aaron B; Rentmeester, Landen; Clark, Richard F; Cantrell, F Lee

    2013-06-01

    Laundry detergent pods (LDPs) have only recently become available in the United States, and there has been increasing concern regarding pediatric ingestions of them. We describe a 15-month-old female infant who ingested an LDP and had a depressed level of consciousness, metabolic acidosis, pulmonary toxicity, and swallowing difficulties. It is currently unclear what the exact etiologic agent(s) is responsible for the toxicity associated with LDPs. The case demonstrates the potential for significant toxicity following the ingestion of an LDP. Clearly, measures should be taken to avoid ingestions of these products.

  12. Cleanser, Detergent, Personal Care Product Pretreatment Evaluation

    NASA Technical Reports Server (NTRS)

    Adam, Niklas

    2010-01-01

    The purpose of the Cleanser, Detergent, Personal Care Product, and Pretreatment Evaluation & Selection task is to identify the optimal combination of personal hygiene products, crew activities, and pretreatment strategies to provide the crew with sustainable life support practices and a comfortable habitat. Minimal energy, mass, and crew time inputs are desired to recycle wastewater during long duration missions. This document will provide a brief background on the work this past year supporting the ELS Distillation Comparison Test, issues regarding use of the hygiene products originally chosen for the test, methods and results used to select alternative products, and lessons learned from testing.

  13. Detergent selection for enhanced extraction of membrane proteins.

    PubMed

    Arachea, Buenafe T; Sun, Zhen; Potente, Nina; Malik, Radhika; Isailovic, Dragan; Viola, Ronald E

    2012-11-01

    Generating stable conditions for membrane proteins after extraction from their lipid bilayer environment is essential for subsequent characterization. Detergents are the most widely used means to obtain this stable environment; however, different types of membrane proteins have been found to require detergents with varying properties for optimal extraction efficiency and stability after extraction. The extraction profiles of several detergent types have been examined for membranes isolated from bacteria and yeast, and for a set of recombinant target proteins. The extraction efficiencies of these detergents increase at higher concentrations, and were shown to correlate with their respective CMC values. Two alkyl sugar detergents, octyl-β-d-glucoside (OG) and 5-cyclohexyl-1-pentyl-β-d-maltoside (Cymal-5), and a zwitterionic surfactant, N-decylphosphocholine (Fos-choline-10), were generally effective in the extraction of a broad range of membrane proteins. However, certain detergents were more effective than others in the extraction of specific classes of integral membrane proteins, offering guidelines for initial detergent selection. The differences in extraction efficiencies among this small set of detergents supports the value of detergent screening and optimization to increase the yields of targeted membrane proteins.

  14. Diffuse corneal abrasion after ocular exposure to laundry detergent pod.

    PubMed

    Whitney, Rachel E; Baum, Carl R; Aronson, Paul L

    2015-02-01

    Although ocular injury from alkaline household cleaning products is well described, there is less known about the significance and extent of injury with ocular exposure to detergent pods. We report a 12-month-old with diffuse corneal abrasion caused by ocular contact with a laundry detergent pod. In addition to the known risks with aspiration with detergent pods, the potential for severe ocular injury is important for parents and clinicians to recognize. Children with ocular exposure to detergent pods should seek immediate medical care.

  15. Heavy metal contents in Egyptian meat and the role of detergent washing on their levels.

    PubMed

    Abou-Arab, A A

    2001-06-01

    Pollution of the environment with heavy metals is a serious problem, which is recognized in most countries of the world. Metals accumulate in the liver, and particularly in the kidneys. The present study provides information about the concentrations of metals in animal organs from both rural and industrial areas. It was surprising that the Pb, Cd, Zn, Cu, Mn and Fe contents in muscle, liver, kidney, heart and spleen in industrial areas were higher than in the same organs of rural areas. Lead concentrations in bovine liver and kidney, in buffalo, elk, sheep and goat kidneys as well as Cd in elk liver and kidneys were higher in the present study than the recommended values. The effect of washing for bovine muscle, liver and kidney using tap water and other detergent solutions on the metals was studied. Washing by only tap water was less effective than the other detergent. The results indicate the efficient role of washing by acidic detergent in the reduction of Pb, Cd and Zn from naturally contaminated meat compared with neutral and alkaline detergent.

  16. Myocardial fibre calcification.

    PubMed Central

    McClure, J; Pieterse, A S; Pounder, D J; Smith, P S

    1981-01-01

    Three cases of myocardial fibre calcification found at post-mortem examination are described. In one case there was antemortem hypercalcaemia and hyperphosphataemia and the case was clearly an example of metastatic calcification. In the other two cases there was ischaemic myocardial necrosis and calcification was seen in fibres which were not overtly necrotic, but which were both in proximity to (the majority) and remote from the necrotic zones. Since renal failure with hyperphosphataemia was present in both cases, these were considered to be examples of augmented (by the hyperphosphataemia) dystrophic calcification. The histological, histochemical and ultrastructural features were identical in the three cases. Hydroxyapatite formation was observed initially in mitochondria, followed by spillage of crystals into the cytosol and ultimately into the interstitium. It is suggested that the fundamental lesion is a dysfunction of the fibre membrane; the similarity of this reaction with the calcification seen in skeletal muscle fibres in various myopathies is noted and a unifying hypothesis of the mechanism of skeletal and cardiac muscle fibre calcification is thereby suggested. Images PMID:7309897

  17. OPTICAL FIBRES AND FIBREOPTIC SENSORS: Bismuth-ring-doped fibres

    NASA Astrophysics Data System (ADS)

    Zlenko, Aleksandr S.; Akhmetshin, Ural G.; Dvoirin, Vladislav V.; Bogatyrev, Vladimir A.; Firstov, Sergei V.

    2009-11-01

    A new process for bismuth doping of optical fibres is proposed in which the dopant is introduced into a thin layer surrounding the fibre core. This enables bismuth stabilisation in the silica glass, with no limitations on the core composition. In particular, the GeO2 content of the fibre core in this study is 16 mol %. Spectroscopic characterisation of such fibres and optical gain measurements suggest that the proposed approach has considerable potential for laser applications.

  18. Interaction of detergent sclerosants with cell membranes.

    PubMed

    Parsi, Kurosh

    2015-06-01

    Commonly used detergent sclerosants including sodium tetradecyl sulphate (STS) and polidocanol (POL) are clinically used to induce endovascular fibrosis and vessel occlusion. They achieve this by lysing the endothelial lining of target vessels. These agents are surface active (surfactant) molecules that interfere with cell membranes. Surfactants have a striking similarity to the phospholipid molecules of the membrane lipid bilayer. By adsorbing at the cell membrane, surfactants disrupt the normal architecture of the lipid bilayer and reduce the surface tension. The outcome of this interaction is concentration dependent. At high enough concentrations, surfactants solubilise cell membranes resulting in cell lysis. At lower concentrations, these agents can induce a procoagulant negatively charged surface on the external aspect of the cell membrane. The interaction is also influenced by the ionic charge, molecular structure, pH and the chemical nature of the diluent (e.g. saline vs. water). The ionic charge of the surfactant molecule can influence the effect on plasma proteins and the protein contents of cell membranes. STS, an anionic detergent, denatures the tertiary complex of most proteins and in particular the clinically relevant clotting factors. By contrast, POL has no effect on proteins due to its non-ionic structure. These agents therefore exhibit remarkable differences in their interaction with lipid membranes, target cells and circulating proteins with potential implications in a range of clinical applications.

  19. Tryptophan octyl ester in detergent micelles of dodecylmaltoside: fluorescence properties and quenching by brominated detergent analogs.

    PubMed Central

    de Foresta, B; Gallay, J; Sopkova, J; Champeil, P; Vincent, M

    1999-01-01

    The fluorescence properties of tryptophan octyl ester (TOE), a hydrophobic model of Trp in proteins, were investigated in various mixed micelles of dodecylmaltoside (DM) and 7,8-dibromododecyl beta-maltoside (BrDM) or 10,11-dibromoundecanoyl beta-maltoside (BrUM). This study focuses on the mechanism via which these brominated detergents quench the fluorescence of TOE in a micellar system. The experiments were performed at a pH at which TOE is uncharged and almost completely bound to detergent micelles. TOE binding was monitored by its enhanced fluorescence in pure DM micelles or its quenched fluorescence in pure BrUM or BrDM micelles. In DM/BrUM and DM/BrDM mixed micelles, the fluorescence intensity of TOE decreased, as a nonlinear function of the molar fraction of brominated detergent, to almost zero in pure brominated detergent. The indole moiety of TOE is therefore highly accessible to the bromine atoms located on the detergent alkyl chain because quenching by bromines occurs by direct contact with the fluorophore. TOE is simultaneously poorly accessible to iodide (I(-)), a water-soluble collisional quencher. TOE time-resolved fluorescence intensity decay is heterogeneous in pure DM micelles, with four lifetimes (from 0.2 to 4.4 ns) at the maximum emission wavelength. Such heterogeneity may arise from dipolar relaxation processes in a motionally restricted medium, as suggested by the time-dependent (nanoseconds) red shift (11 nm) of the TOE emission spectrum, and from the existence of various TOE conformations. Time-resolved quenching experiments for TOE in mixed micelles showed that the excited-state lifetime values decreased only slightly with increases in the proportion of BrDM or BrUM. In contrast, the relative amplitude of the component with the longest lifetime decreased significantly relative to that of the short-lived species. This is consistent with a mainly static mechanism for the quenching of TOE by brominated detergents. Molecular modeling of TOE

  20. Use of quaternary ammonium salts of nitrogen containing polymers for improved carburetor detergency

    SciTech Connect

    Biasotti, J.B.; Vartanian, P.F.

    1980-01-15

    A quaternary ammonium salt is described of a copolymer, said copolymer being the olefin polymerization product of: (A) a nitrogen amine free ester of a C/sub 1/-C/sub 6/ olefinically unsaturated aliphatic mono-, di-, or polycarboxylic acid having a tertiary nitrogen atom; and (B) an olefinically unsaturated co-monomer containing a basic nitrogen atom in a side chain; a fuel component, especially gasoline, containing such quaternary ammonium salt of such copolymer as a detergent.

  1. Effect of non-lytic concentrations of Brij series detergents on the metabolism-independent ion permeability properties of human erythrocytes.

    PubMed Central

    Miseta, A; Bogner, P; Szarka, A; Kellermayer, M; Galambos, C; Wheatley, D N; Cameron, I L

    1995-01-01

    Subcritical micellar concentrations (sub-CMC) of Brij-series detergents alter ion movements between human erythrocytes and their environment when metabolism has been slowed down by incubation at zero degrees centigrade. The effect of nonhemolytic concentrations of detergents on the erythrocyte K+ and Na+ movements is described. Results indicate a significant difference in monovalent cation movements, depending on the number of hydrophilic polyoxyethylene units (n). There is an increasing loss of K+ and gain of Na+ as n increases from 4 to 20. Where n > or = 21, ion movements are not significantly different from those found in erythrocytes not exposed to detergents. The carbon chain length of the detergent fatty acid residue (10-18 carbons) appears to be relatively unimportant, but detergents with unsaturated (oleic acid) hydrophobic regions potentiate K+ release and Na+ uptake when compared to the corresponding saturated fatty acid (stearic acid). The erythrocyte stabilizing effect of detergents against hypo-osmotic shock correlates well with the increase of monovalent ion traffic and the mobility of membrane lipids revealed by fluorescence anisotropy measurements. PMID:8599663

  2. Characterization of chemically and enzymatically treated hemp fibres using atomic force microscopy and spectroscopy

    NASA Astrophysics Data System (ADS)

    George, Michael; Mussone, Paolo G.; Abboud, Zeinab; Bressler, David C.

    2014-09-01

    The mechanical and moisture resistance properties of natural fibre reinforced composites are dependent on the adhesion between the matrix of choice and the fibre. The main goal of this study was to investigate the effect of NaOH swelling of hemp fibres prior to enzymatic treatment and a novel chemical sulfonic acid method on the physical properties of hemp fibres. The colloidal properties of treated hemp fibres were studied exclusively using an atomic force microscope. AFM imaging in tapping mode revealed that each treatment rendered the surface topography of the hemp fibres clean and exposed the individual fibre bundles. Hemp fibres treated with laccase had no effect on the surface adhesion forces measured. Interestingly, mercerization prior to xylanase + cellulase and laccase treatments resulted in greater enzyme access evident in the increased adhesion force measurements. Hemp fibres treated with sulfonic acid showed an increase in surface de-fibrillation and smoothness. A decrease in adhesion forces for 4-aminotoulene-3-sulfonic acid (AT3S) treated fibres suggested a reduction in surface polarity. This work demonstrated that AFM can be used as a tool to estimate the surface forces and roughness for modified fibres and that enzymatic coupled with chemical methods can be used to improve the surface properties of natural fibres for composite applications. Further, this work is one of the first that offers some insight into the effect of mercerization prior to enzymes and the effect on the surface topography. AFM will be used to selectively screen treated fibres for composite applications based on the adhesion forces associated with the colloidal interface between the AFM tip and the fibre surfaces.

  3. Study of Small Angle X-Ray Scattering Features of Acid- and Alkali-Treated Silk Fibre (Mulberry) Using Correlation Functions

    NASA Astrophysics Data System (ADS)

    Misra, Tripurari; Panda, Pramoda; Patel, Tnkadhar; Bisoyi, Dillip K.; Panda, Dillip K.

    1993-10-01

    Silk fibres at room temperature after treatment with solutions of HCl (pH=2) and NaOH (pH=10) have been investigated using the SAXS (small angle X-ray scattering) technique. The theories developed by Vonk (1973) and Ruland (1971) for nonideal two-phase structure characterised by continuous variation of electron density at the phase boundary have been applied to calculate various macromolecular parameters such as the width of transition layer, the average periodicity transverse to the layer, the specific inner surface, the length of coherence, the transversal lengths in matter and void, the range of inhomogeneity, the volume fractions of matter and void, the volume fraction of the transition layer and the characteristic number.

  4. Detergent-free purification of ABC (ATP-binding-cassette) transporters.

    PubMed

    Gulati, Sonali; Jamshad, Mohammed; Knowles, Timothy J; Morrison, Kerrie A; Downing, Rebecca; Cant, Natasha; Collins, Richard; Koenderink, Jan B; Ford, Robert C; Overduin, Michael; Kerr, Ian D; Dafforn, Timothy R; Rothnie, Alice J

    2014-07-15

    ABC (ATP-binding-cassette) transporters carry out many vital functions and are involved in numerous diseases, but study of the structure and function of these proteins is often hampered by their large size and membrane location. Membrane protein purification usually utilizes detergents to solubilize the protein from the membrane, effectively removing it from its native lipid environment. Subsequently, lipids have to be added back and detergent removed to reconstitute the protein into a lipid bilayer. In the present study, we present the application of a new methodology for the extraction and purification of ABC transporters without the use of detergent, instead, using a copolymer, SMA (polystyrene-co-maleic acid). SMA inserts into a bilayer and assembles into discrete particles, essentially solubilizing the membrane into small discs of bilayer encircled by a polymer, termed SMALPs (SMA lipid particles). We show that this polymer can extract several eukaryotic ABC transporters, P-glycoprotein (ABCB1), MRP1 (multidrug-resistance protein 1; ABCC1), MRP4 (ABCC4), ABCG2 and CFTR (cystic fibrosis transmembrane conductance regulator; ABCC7), from a range of different expression systems. The SMALP-encapsulated ABC transporters can be purified by affinity chromatography, and are able to bind ligands comparably with those in native membranes or detergent micelles. A greater degree of purity and enhanced stability is seen compared with detergent solubilization. The present study demonstrates that eukaryotic ABC transporters can be extracted and purified without ever being removed from their lipid bilayer environment, opening up a wide range of possibilities for the future study of their structure and function.

  5. Effects of Water Hardness on Textile Detergency Performance in Aqueous Cleaning Systems.

    PubMed

    Gotoh, Keiko; Horibe, Kaori; Mei, Yang; Tsujisaka, Toshiyuki

    2016-01-01

    The effects of water hardness on textile detergency in aqueous solutions were systematically investigated using four surfactants: sodium oleate (OLNa), linear dodecylbenzene sulfonate (LAS), sodium dodecyl sulfate (AS), and polyoxyethylene (10) dodecyl ether (AE). Water hardness was adjusted according to the standard procedure described in IEC 60734:2012. As expected, by adding hardness salts the surface tension of the OLNa solution increased. Surprisingly, the addition of hardness salts lowers the surface tension for the LAS and AS solutions. In the case of the AE solution, hardness salt did not affect the surface tension. A decrease in transmittance and foamability after adding hardness salts was observed for every anionic surfactant solution, indicating that anionic surfactants can combine with divalent ions to form insoluble precipitates. Detergency experiments were performed using cotton plain-woven and towel fabrics soiled with a carbon black and oleic acid mixture. One piece each of untreated and soiled fabric were stacked and placed horizontally in detergent solution with or without hardness salts. As a mechanical action of soil removal, the shaking of 190 spm was applied. Soil removal and redeposition due to washing were evaluated from changes in values of the Kubelka-Munk function for both fabrics. With increasing water hardness, soil removal decreased and redeposition increased. In order of decreasing detergency, the surfactants were as follows: LAS > OLNa ≈ AS > AE. The results indicate that precipitates, formed by reaction of LAS or AS with hardness salts, are strongly adsorbed on the water surface because of their hydrophobicity, but they have no detergency power. The field emission scanning electron microscopic observation and X-ray photoelectron spectroscopic analysis showed that Ca(LAS)2 precipitation clung to fiber surfaces, and remained on the surfaces after washing. Significant changes in the cotton fabric due to washing were observed in

  6. Effects of Water Hardness on Textile Detergency Performance in Aqueous Cleaning Systems.

    PubMed

    Gotoh, Keiko; Horibe, Kaori; Mei, Yang; Tsujisaka, Toshiyuki

    2016-01-01

    The effects of water hardness on textile detergency in aqueous solutions were systematically investigated using four surfactants: sodium oleate (OLNa), linear dodecylbenzene sulfonate (LAS), sodium dodecyl sulfate (AS), and polyoxyethylene (10) dodecyl ether (AE). Water hardness was adjusted according to the standard procedure described in IEC 60734:2012. As expected, by adding hardness salts the surface tension of the OLNa solution increased. Surprisingly, the addition of hardness salts lowers the surface tension for the LAS and AS solutions. In the case of the AE solution, hardness salt did not affect the surface tension. A decrease in transmittance and foamability after adding hardness salts was observed for every anionic surfactant solution, indicating that anionic surfactants can combine with divalent ions to form insoluble precipitates. Detergency experiments were performed using cotton plain-woven and towel fabrics soiled with a carbon black and oleic acid mixture. One piece each of untreated and soiled fabric were stacked and placed horizontally in detergent solution with or without hardness salts. As a mechanical action of soil removal, the shaking of 190 spm was applied. Soil removal and redeposition due to washing were evaluated from changes in values of the Kubelka-Munk function for both fabrics. With increasing water hardness, soil removal decreased and redeposition increased. In order of decreasing detergency, the surfactants were as follows: LAS > OLNa ≈ AS > AE. The results indicate that precipitates, formed by reaction of LAS or AS with hardness salts, are strongly adsorbed on the water surface because of their hydrophobicity, but they have no detergency power. The field emission scanning electron microscopic observation and X-ray photoelectron spectroscopic analysis showed that Ca(LAS)2 precipitation clung to fiber surfaces, and remained on the surfaces after washing. Significant changes in the cotton fabric due to washing were observed in

  7. Biodegradability, toxicity and mutagenicity of detergents: Integrated experimental evaluations.

    PubMed

    Pedrazzani, Roberta; Ceretti, Elisabetta; Zerbini, Ilaria; Casale, Rosario; Gozio, Eleonora; Bertanza, Giorgio; Gelatti, Umberto; Donato, Francesco; Feretti, Donatella

    2012-10-01

    The widespread use of detergents has raised concern with regard to the environmental pollution caused by their active ingredients, which are biorefractory, toxic and persistent. Since detergents are complex mixtures of different substances, in which synergistic effects may occur, we aimed to assess the mutagenicity of different detergent formulations, taking into account aquatic toxicity and ready biodegradability. We performed a ready biodegradability test (OECD 301 F), Daphnia magna and Vibrio fischeri toxicity tests, and mutagenicity tests (Salmonella/microsome test, Allium cepa test and comet assay). Six detergent formulations were examined, 3 pre-manufacture and 3 commercially available. All detergents presented ready biodegradability. EC50 values varied for all products, according to the marker organism used, but were always higher than the more stringent value considered for aquatic toxicity assessment (V. fischeri 10-60 mg/L; D. magna 25-300 mg/L; A. cepa 250-2000 mg/L). None of the detergents caused mutations in bacteria. However, one commercial ecolabelled product induced an increase in micronucleus frequency in A. cepa root cells. All pre-manufacture detergents and one commercial one, which gave negative results in the Ames and A. cepa tests, induced DNA damage in human leukocytes. A more accurate evaluation of the environmental impact of complex mixtures such as detergents requires a battery of tests to describe degradation, as well as toxicological and mutagenic features.

  8. 21 CFR 740.17 - Foaming detergent bath products.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 7 2011-04-01 2010-04-01 true Foaming detergent bath products. 740.17 Section 740.17 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.17 Foaming detergent bath...

  9. 21 CFR 740.17 - Foaming detergent bath products.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 7 2012-04-01 2012-04-01 false Foaming detergent bath products. 740.17 Section 740.17 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.17 Foaming detergent bath...

  10. 21 CFR 740.17 - Foaming detergent bath products.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 7 2010-04-01 2010-04-01 false Foaming detergent bath products. 740.17 Section 740.17 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.17 Foaming detergent bath...

  11. 21 CFR 740.17 - Foaming detergent bath products.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 7 2014-04-01 2014-04-01 false Foaming detergent bath products. 740.17 Section 740.17 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.17 Foaming detergent bath...

  12. 21 CFR 740.17 - Foaming detergent bath products.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 7 2013-04-01 2013-04-01 false Foaming detergent bath products. 740.17 Section 740.17 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) COSMETICS COSMETIC PRODUCT WARNING STATEMENTS Warning Statements § 740.17 Foaming detergent bath...

  13. Concentrating membrane proteins using ultrafiltration without concentrating detergents.

    PubMed

    Feroz, Hasin; Vandervelden, Craig; Ikwuagwu, Bon; Ferlez, Bryan; Baker, Carol S; Lugar, Daniel J; Grzelakowski, Mariusz; Golbeck, John H; Zydney, Andrew L; Kumar, Manish

    2016-10-01

    Membrane proteins (MPs) are of rapidly growing interest in the design of pharmaceutical products, novel sensors, and synthetic membranes. Ultrafiltration (UF) using commercially available centrifugal concentrators is typically employed for laboratory-scale concentration of low-yield MPs, but its use is accompanied by a concomitant increase in concentration of detergent micelles. We present a detailed analysis of the hydrodynamic processes that control detergent passage during ultrafiltration of MPs and propose methods to optimize detergent passage during protein concentration in larger-scale membrane processes. Experiments were conducted using nonionic detergents, octyl-β-D glucoside (OG), and decyl-β-D maltoside (DM) with the bacterial water channel protein, Aquaporin Z (AqpZ) and the light driven chloride pump, halorhodopsin (HR), respectively. The observed sieving coefficient (So ), a measure of detergent passage, was evaluated in both stirred cell and centrifugal systems. So for DM and OG increased with increasing filtrate flux and decreasing shear rates in the stirred cell, that is, with increasing concentration polarization (CP). Similar effects were observed during filtration of MP-detergent (MPD) micelles. However, lower transmission was observed in the centrifugal system for both detergent and MPD systems. This is attributed to free convection-induced shear and hence reduced CP along the membrane surface during centrifugal UF. Thus to concentrate MPs without retention of detergent, design of UF systems that promote CP is required. Biotechnol. Bioeng. 2016;113: 2122-2130. © 2016 Wiley Periodicals, Inc. PMID:27563851

  14. Two detergent stable alkaline serine-proteases from Bacillus mojavensis A21: purification, characterization and potential application as a laundry detergent additive.

    PubMed

    Haddar, Anissa; Agrebi, Rym; Bougatef, Ali; Hmidet, Noomen; Sellami-Kamoun, Alya; Nasri, Moncef

    2009-07-01

    Two detergent stable alkaline serine-proteases (BM1 and BM2) from Bacillus mojavensis A21 were purified. The molecular weights of BM1 and BM2 enzymes determined by SDS-PAGE were approximately 29,00 Da and 15,50 Da, respectively. The optimum pH values of BM1 and BM2 proteases were shown to be 8.0-10.0 and 10.0, respectively. Both enzymes exhibited maximal activity at 60 degrees C, using casein as a substrate. The N-terminal amino acid sequences of BM1 and BM2 proteases were AQSVPYGISQIKA and AIPDQAATTLL, respectively. Both proteases showed high stability towards non-ionic surfactants. The enzymes were found to be relatively stable towards oxidizing agents. In addition, both enzymes showed excellent stability and compatibility with a wide range of commercial liquid and solid detergents. These properties and the high activity in high alkaline pH make these proteases an ideal choice for application in detergent formulations.

  15. Variation of the detergent-binding capacity and phospholipid content of membrane proteins when purified in different detergents.

    PubMed

    Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Gachet, María Salomé; Boggavarapu, Rajendra; Ucurum, Zöhre; Gertsch, Jürg; Fotiadis, Dimitrios

    2014-04-15

    Purified membrane proteins are ternary complexes consisting of protein, lipid, and detergent. Information about the amounts of detergent and endogenous phospholipid molecules bound to purified membrane proteins is largely lacking. In this systematic study, three model membrane proteins of different oligomeric states were purified in nine different detergents at commonly used concentrations and characterized biochemically and biophysically. Detergent-binding capacities and phospholipid contents of the model proteins were determined and compared. The insights on ternary complexes obtained from the experimental results, when put into a general context, are summarized as follows. 1), The amount of detergent and 2) the amount of endogenous phospholipids bound to purified membrane proteins are dependent on the size of the hydrophobic lipid-accessible protein surface areas and the physicochemical properties of the detergents used. 3), The size of the detergent and lipid belt surrounding the hydrophobic lipid-accessible surface of purified membrane proteins can be tuned by the appropriate choice of detergent. 4), The detergents n-nonyl-β-D-glucopyranoside and Cymal-5 have exceptional delipidating effects on ternary complexes. 5), The types of endogenous phospholipids bound to membrane proteins can vary depending on the detergent used for solubilization and purification. 6), Furthermore, we demonstrate that size-exclusion chromatography can be a suitable method for estimating the molecular mass of ternary complexes. The findings presented suggest a strategy to control and tune the numbers of detergent and endogenous phospholipid molecules bound to membrane proteins. These two parameters are potentially important for the successul crystallization of membrane proteins for structure determination by crystallographic approaches.

  16. Variation of the Detergent-Binding Capacity and Phospholipid Content of Membrane Proteins When Purified in Different Detergents

    PubMed Central

    Ilgü, Hüseyin; Jeckelmann, Jean-Marc; Gachet, María Salomé; Boggavarapu, Rajendra; Ucurum, Zöhre; Gertsch, Jürg; Fotiadis, Dimitrios

    2014-01-01

    Purified membrane proteins are ternary complexes consisting of protein, lipid, and detergent. Information about the amounts of detergent and endogenous phospholipid molecules bound to purified membrane proteins is largely lacking. In this systematic study, three model membrane proteins of different oligomeric states were purified in nine different detergents at commonly used concentrations and characterized biochemically and biophysically. Detergent-binding capacities and phospholipid contents of the model proteins were determined and compared. The insights on ternary complexes obtained from the experimental results, when put into a general context, are summarized as follows. 1), The amount of detergent and 2) the amount of endogenous phospholipids bound to purified membrane proteins are dependent on the size of the hydrophobic lipid-accessible protein surface areas and the physicochemical properties of the detergents used. 3), The size of the detergent and lipid belt surrounding the hydrophobic lipid-accessible surface of purified membrane proteins can be tuned by the appropriate choice of detergent. 4), The detergents n-nonyl-β-D-glucopyranoside and Cymal-5 have exceptional delipidating effects on ternary complexes. 5), The types of endogenous phospholipids bound to membrane proteins can vary depending on the detergent used for solubilization and purification. 6), Furthermore, we demonstrate that size-exclusion chromatography can be a suitable method for estimating the molecular mass of ternary complexes. The findings presented suggest a strategy to control and tune the numbers of detergent and endogenous phospholipid molecules bound to membrane proteins. These two parameters are potentially important for the successul crystallization of membrane proteins for structure determination by crystallographic approaches. PMID:24739165

  17. Skin safety evaluation of laundry detergent products.

    PubMed

    Kwon, Seok; Holland, Daniela; Kern, Petra

    2009-01-01

    The conduct of a scientifically sound safety assessment of new ingredients and finished products is essential prior to their introduction into the marketplace. Such assessments are based on a risk assessment paradigm established by the National Academy of Science (NAS, 1983) that consists of a four-step process: hazard identification, dose-response assessment, exposure assessment, and risk characterization. This risk assessment paradigm has been (1) used as a framework for estimating an adverse health risk posed by environmental chemicals, and (2) applied to systemic toxicological endpoints. The general principles of risk assessment may be applied to skin safety evaluation of consumer products, considering that dermal toxicity is also a threshold phenomenon. This study describes a risk assessment-based approach for skin safety evaluation of laundry detergent products.

  18. The application of heated detergent dewaxing and rehydration to immunohistochemistry.

    PubMed

    Henwood, A F

    2012-01-01

    Hot commercial dishwashing detergent has been used to deparaffinize and hydrate formalin fixed, paraffin embedded sections for immunohistochemistry. Fifty-five antibodies, used routinely for diagnosis, were used to compare hot detergent dewaxing with the proprietary hydrocarbon-based dewaxing reagent supplied with the Bond Max immunohistochemistry system®. A 2% concentration of commercial dishwashing detergent in distilled water was heated to 90° C and paraffin sections were treated twice for 1 min each. Nearly all antibodies gave equivalent results except CD10 and CD57 (hydrocarbon-based dewaxing better) and CD45 and alpha fetoprotein (detergent dewaxing better); the differences, however, were minimal. There also was a significant cost saving using detergent dewaxing. PMID:20854225

  19. A fluorinated detergent for membrane-protein applications.

    PubMed

    Frotscher, Erik; Danielczak, Bartholomäus; Vargas, Carolyn; Meister, Annette; Durand, Grégory; Keller, Sandro

    2015-04-20

    Surfactants carrying fluorocarbon chains hold great promise as gentle alternatives to conventional hydrocarbon-based detergents for the solubilization and handling of integral membrane proteins. However, their inertness towards lipid bilayer membranes has limited the usefulness of fluorinated surfactants in situations where detergent-like activity is required. We demonstrate that fluorination does not necessarily preclude detergency, as exemplified by a fluorinated octyl maltoside derivative termed F6 OM. This nonionic compound readily interacts with and completely solubilizes phospholipid vesicles in a manner reminiscent of conventional detergents without, however, compromising membrane order at subsolubilizing concentrations. Owing to this mild and unusual mode of detergency, F6 OM outperforms a lipophobic fluorinated surfactant in chaperoning the functional refolding of an integral membrane enzyme by promoting bilayer insertion in the absence of micelles.

  20. Quantification of detergent using colorimetric methods in membrane protein crystallography.

    PubMed

    Prince, Chelsy; Jia, Zongchao

    2015-01-01

    Membrane protein crystallography has the potential to greatly aid our understanding of membrane protein biology. Yet, membrane protein crystals remain challenging to produce. Although robust methods for the expression and purification of membrane proteins continue to be developed, the detergent component of membrane protein samples is equally important to crystallization efforts. This chapter describes the development of three colorimetric assays for the quantitation of detergent in membrane protein samples and provides detailed protocols. All of these techniques use small sample volumes and have potential applications in crystallography. The application of these techniques in crystallization prescreening, detergent concentration modification, and detergent exchange experiments is demonstrated. It has been observed that the concentration of detergent in a membrane protein sample can be just as important as the protein concentration when attempting to reproduce crystallization lead conditions.

  1. 75 FR 71123 - Agency Information Collection Activities; Proposed Collection; Comment Request; Safer Detergent...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-22

    ... AGENCY Agency Information Collection Activities; Proposed Collection; Comment Request; Safer Detergent... ICR, entitled: ``Safer Detergent Stewardship Initiative (SDSI) Program'' and identified by EPA ICR No... surfactants. Title: Safer Detergent Stewardship Initiative (SDSI) Program. ICR numbers: EPA ICR No....

  2. Characterisation of phenolic compounds in processed fibres from the juice industry.

    PubMed

    Delpino-Rius, Antoni; Eras, Jordi; Vilaró, Francisca; Cubero, Miguel Ángel; Balcells, Mercè; Canela-Garayoa, Ramon

    2015-04-01

    The content of phenolic compounds was determined in nine industrially processed fibres derived from the juice industry. Apple, peach, and pear as non-citrus fruit fibres were examined, as well as orange peel and flesh, tangerine peel and flesh, and lemon flesh as citrus fruit fibres, and carrot as vegetable fibre. The extractable phenolic profile of all fibres was obtained by UPLC-PDA-FLR-MS/MS. Forty phenolic compounds were identified and their concentrations determined. In addition, bound phenolic acids and proanthocyanidins were measured in solid residues in order to determine the phenolic compounds remaining. Also, to allow the comparison of the profiles and contents in the fresh fruit and fibres, we analysed extractable and bound phenolic compounds in lyophilized peel and pulp from fresh fruit. The profile and phenolic content of the fibres was similar to that of the fresh fruit, except for flavan-3-ols, which registered lower values.

  3. Characterization of the Protease Activity of Detergents: Laboratory Practicals for Studying the Protease Profile and Activity of Various Commercial Detergents

    ERIC Educational Resources Information Center

    Valls, Cristina; Pujadas, Gerard; Garcia-Vallve, Santi; Mulero, Miquel

    2011-01-01

    Detergent enzymes account for about 30% of the total worldwide production of enzymes and are one of the largest and most successful applications of modern industrial biotechnology. Proteases can improve the wash performance of household, industrial, and institutional laundry detergents used to remove protein-based stains such as blood, grass, body…

  4. A novel method to determine residual detergent in biological samples post endotoxin reduction treatment and evaluation of strategies for subsequent detergent removal.

    PubMed

    London, Anne Serdakowski; Japutra, Chietara; Planck, Kyle; Lihon, Michael; Nguyen, Andrew Anh

    2016-08-01

    Endotoxin removal using detergent washes and extractions are well-established, efficient, and cost-effective methods; however, removing residual detergent post treatment has been shown to be a challenge. In this communication, we show a simple and fast method for determining the detergent concentration in a protein solution post treatment and highlight strategies for detergent removal to achieve levels below the critical micelle concentration (CMC), the minimum concentration at which detergent micelles form. PMID:26627559

  5. Tonoplast of Beta vulgaris L. contains detergent-resistant membrane microdomains.

    PubMed

    Ozolina, Natalia V; Nesterkina, Irina S; Kolesnikova, Ekaterina V; Salyaev, Ryurik K; Nurminsky, Vadim N; Rakevich, Alexander L; Martynovich, Evgueni F; Chernyshov, Michael Yu

    2013-03-01

    The experiments conducted on tonoplast of Beta vulgaris L. roots were performed to identify detergent-resistant lipid-protein microdomains (DRMs, interpreted as lipid rafts).The presence of DRMs can be found when dynamic clustering of sphingolipids, sterols, saturated fatty acids is registered, and the insolubility of these microdomains in nonionic detergents at low temperatures is proven. The elucidation of tonoplast microdomains has been based on results obtained with the aid of high-speed centrifuging in the sucrose gradient. The experiments have shown that tonoplast microdomains are rich in sphingolipids, free sterols and saturated fatty acids (such a lipid content is also typical of lipid-protein microdomains of other membranes), while only few phospholipids are present in tonoplast microdomains. The presence of microdomains has been confirmed by fluorescence and confocal microscopy using filipin and Laurdan as fluorescent probes. The experiments with Laurdan have shown that tonoplast microdomains are characterized by a high order compared to characteristics of the rest of the tonoplast. Thus, the presence of detergent-resistant lipid-protein microdomains in the tonoplast has been demonstrated.

  6. Potential Benefits of Dietary Fibre Intervention in Inflammatory Bowel Disease

    PubMed Central

    Wong, Celestine; Harris, Philip J.; Ferguson, Lynnette R.

    2016-01-01

    Intestinal dysbiosis is thought to be an important cause of disease progression and the gastrointestinal symptoms experienced in patients with inflammatory bowel disease (IBD). Inflammation appears to be a major contributor in perpetuating a dysregulated gut microbiota. Although current drug therapies can significantly induce and maintain disease remission, there is no cure for these diseases. Nevertheless, ongoing human studies investigating dietary fibre interventions may potentially prove to exert beneficial outcomes for IBD. Postulated mechanisms include direct interactions with the gut mucosa through immunomodulation, or indirectly through the microbiome. Component species of the microbiome may degrade dietary-fibre polysaccharides and ferment the products to form short-chain fatty acids such as butyrate. Prebiotic dietary fibres may also act more directly by altering the composition of the microbiome. Longer term benefits in reducing the risk of more aggressive disease or colorectal cancer may require other dietary fibre sources such as wheat bran or psyllium. By critically examining clinical trials that have used dietary fibre supplements or dietary patterns containing specific types or amounts of dietary fibres, it may be possible to assess whether varying the intake of specific dietary fibres may offer an efficient treatment for IBD patients. PMID:27314323

  7. Potential Benefits of Dietary Fibre Intervention in Inflammatory Bowel Disease.

    PubMed

    Wong, Celestine; Harris, Philip J; Ferguson, Lynnette R

    2016-01-01

    Intestinal dysbiosis is thought to be an important cause of disease progression and the gastrointestinal symptoms experienced in patients with inflammatory bowel disease (IBD). Inflammation appears to be a major contributor in perpetuating a dysregulated gut microbiota. Although current drug therapies can significantly induce and maintain disease remission, there is no cure for these diseases. Nevertheless, ongoing human studies investigating dietary fibre interventions may potentially prove to exert beneficial outcomes for IBD. Postulated mechanisms include direct interactions with the gut mucosa through immunomodulation, or indirectly through the microbiome. Component species of the microbiome may degrade dietary-fibre polysaccharides and ferment the products to form short-chain fatty acids such as butyrate. Prebiotic dietary fibres may also act more directly by altering the composition of the microbiome. Longer term benefits in reducing the risk of more aggressive disease or colorectal cancer may require other dietary fibre sources such as wheat bran or psyllium. By critically examining clinical trials that have used dietary fibre supplements or dietary patterns containing specific types or amounts of dietary fibres, it may be possible to assess whether varying the intake of specific dietary fibres may offer an efficient treatment for IBD patients. PMID:27314323

  8. Susceptibility of biofilm Escherichia coli, Salmonella Enteritidis and Staphylococcus aureus to detergents and sanitizers.

    PubMed

    Ueda, Shigeko; Kuwabara, Yoshihiro

    2007-12-01

    This study was conducted to investigate the susceptibility of the biofilm cells of Escherichia coli O157, Salmonella Enteritidis, and Staphylococcus aureus to some cleaning detergents and sanitizers. No weakly acidic, neutral, and weakly alkaline detergent could remove the biofilm bacteria from stainless steel chips at commonly used concentrations recommended by manufacturers. Among sanitizers, sodium hypochlorite did not completely inactivate any biofilm bacteria at active chlorine concentrations of 25 to 200 microg/ml. Benzalkonium chloride, alkyldiaminoethyl glycine hydrochloride, chlorhexidine digluconate, and polyhexamethylenebiganide inactivated the great majority of E. coli and S. Enteritidis at commonly used concentrations, but did not inactivate S. aureus effectively enough. The biofilm S. aureus population was shown to be more tolerant than the E. coli and/or S. Enteritidis populations to the sanitizers. PMID:18198721

  9. Structure of the C-terminal head domain of the fowl adenovirus type 1 short fibre

    SciTech Connect

    El Bakkouri, Majida; Seiradake, Elena; Cusack, Stephen; Ruigrok, Rob W.H. Schoehn, Guy

    2008-08-15

    There are more than 100 known adenovirus serotypes, including 50 human serotypes. They can infect all 5 major vertebrate classes but only Aviadenovirus infecting birds and Mastadenovirus infecting mammals have been well studied. CELO (chicken embryo lethal orphan) adenovirus is responsible for mild respiratory pathologies in birds. Most studies on CELO virus have focussed on its genome sequence and organisation whereas the structural work on CELO proteins has only recently started. Contrary to most adenoviruses, the vertices of CELO virus reveal pentons with two fibres of different lengths. The distal parts (or head) of those fibres are involved in cellular receptor binding. Here we have determined the atomic structure of the short-fibre head of CELO (amino acids 201-410) at 2.0 A resolution. Despite low sequence identity, this structure is conserved compared to the other adenovirus fibre heads. We have used the existing CELO long-fibre head structure and the one we show here for a structure-based alignment of 11 known adenovirus fibre heads which was subsequently used for the construction of an evolutionary tree. Both the fibre head sequence and structural alignments suggest that enteric human group F adenovirus 41 (short fibre) is closer to the CELO fibre heads than the canine CAdV-2 fibre head, that lies closer to the human virus fibre heads.

  10. Interactions of myelin basic protein with mixed dodecylphosphocholine/palmitoyllysophosphatidic acid micelles

    SciTech Connect

    Mendz, G.L. ); Brown, L.R. ); Martenson, R.E. )

    1990-03-06

    The interactions of myelin basic protein and peptides derived from it with detergent micelles of lysophosphatidylglycerol, lysophosphatidylserine, palmitoyllysophosphatidic acid, and sodium lauryl sulfate, and with mixed micelles of the neutral detergent dodecylphosphocholine and the negatively charged detergent palmitoyllysophosphatidic acid, were investigated by {sup 1}H NMR spectroscopy and circular dichroic spectropolarimetry. The results with single detergents suggested that there are discrete interaction sites in the protein molecule for neutral and anionic detergent micelles and that at least some of these sites are different for each type of detergent. The data on the binding of the protein and peptides to mixed detergent micelles suggested that intramolecular interactions in the intact protein and in one of the longer peptides limited the formation of helices and also that a balance between hydrophobic and ionic forces is achieved in the interactions of the peptides with the detergents. At high detergent/protein molar ratios, hydrophobic interactions appeared to be favored.

  11. Solubilization of human erythrocyte membranes by ASB detergents.

    PubMed

    Domingues, C C; Malheiros, S V P; Paula, E de

    2008-09-01

    Understanding the membrane solubilization process and finding effective solubilizing agents are crucial challenges in biochemical research. Here we report results on the interaction of the novel linear alkylamido propyl dimethyl amino propanosulfonate detergents, ASB-14 and ASB-16, with human erythrocyte membranes. An estimation of the critical micelle concentration of these zwitterionic detergents (ASB-14 = 100 microM and ASB-16 = 10 microM) was obtained using electron paramagnetic resonance. The amount of proteins and cholesterol solubilized from erythrocytes by these detergents was then determined. The hemolytic activities of the ASB detergents were assayed and the detergent/lipid molar ratios for the onset of hemolysis (Re sat) and total lysis (Re sol) were calculated, allowing the determination of the membrane binding constants (Kb). ASB-14 presented lower membrane affinity (Kb = 7050 M(-1)) than ASB-16 (Kb = 15610 M(-1)). The amount of proteins and cholesterol solubilized by both ASB detergents was higher while Re sat values (0.22 and 0.08 detergent/lipid for ASB-14 and ASB-16, respectively) were smaller than those observed with the classic detergents CHAPS and Triton X-100. These results reveal that, besides their well-known use as membrane protein solubilizers to enhance the resolution of two dimensional electrophoresis/mass spectrometry, ASB-14 and ASB-16 are strong hemolytic agents. We propose that the physicochemical properties of ASB detergents determine their membrane disruption efficiency and can help to explain the improvement in the solubilization of membrane proteins, as reported in the literature.

  12. Solvent/detergent plasma: pharmaceutical characteristics and clinical experience.

    PubMed

    Liumbruno, Giancarlo Maria; Franchini, Massimo

    2015-01-01

    The solvent/detergent treatment is an established virus inactivation technology that has been industrially applied for manufacturing plasma derived medicinal products for almost 30 years. Solvent/detergent plasma is a pharmaceutical product with standardised content of clotting factors, devoid of antibodies implicated in transfusion-related acute lung injury pathogenesis, and with a very high level of decontamination from transfusion-transmissible infectious agents. Many clinical studies have confirmed its safety and efficacy in the setting of congenital as well as acquired bleeding disorders. This narrative review will focus on the pharmaceutical characteristics of solvent/detergent plasma and the clinical experience with this blood product.

  13. Effect of synthetic detergents on germination of fern spores

    SciTech Connect

    Devi, Y.; Devi, S.

    1986-12-01

    Synthetic detergents constitute one of the most important water pollutants by contaminating the lakes and rivers through domestic and industrial use. Considerable information is now available for the adverse effects of detergents an aquatic fauna including fish, algae, and higher aquatic plants. Marked inhibition of germination in orchids and brinjals and of seedlings growth in raddish suggest that rapidly growing systems could be sensitive to detergent polluted water. The present study of the effect of linear alkyl benzene sulphonate on germination of the spores of a fern, Diplazium esculentum aims at the understanding of the effects of water pollution on pteridophytes and the development of spore germination assay for phytoxicity evaluation.

  14. Electrical lysis of cells for detergent-free droplet assays

    PubMed Central

    Tran, T. M.; Abate, A. R.

    2016-01-01

    Efficient lysis is critical when analyzing single cells in microfluidic droplets, but existing methods utilize detergents that can interfere with the assays to be performed. We demonstrate robust cell lysis without the use of detergents or other chemicals. In our method, cells are exposed to electric field immediately before encapsulation in droplets, resulting in cell lysis. We characterize lysis efficiency as a function of control parameters and demonstrate compatibility with enzymatic assays by measuring the catalysis of β-glucosidase, an important cellulase used in the conversion of biomass to biofuel. Our method enables assays in microfluidic droplets that are incompatible with detergents. PMID:27051471

  15. Electrical lysis of cells for detergent-free droplet assays.

    PubMed

    de Lange, N; Tran, T M; Abate, A R

    2016-03-01

    Efficient lysis is critical when analyzing single cells in microfluidic droplets, but existing methods utilize detergents that can interfere with the assays to be performed. We demonstrate robust cell lysis without the use of detergents or other chemicals. In our method, cells are exposed to electric field immediately before encapsulation in droplets, resulting in cell lysis. We characterize lysis efficiency as a function of control parameters and demonstrate compatibility with enzymatic assays by measuring the catalysis of β-glucosidase, an important cellulase used in the conversion of biomass to biofuel. Our method enables assays in microfluidic droplets that are incompatible with detergents. PMID:27051471

  16. Characterization of the protease activity of detergents: laboratory practicals for studying the protease profile and activity of various commercial detergents.

    PubMed

    Valls, Cristina; Pujadas, Gerard; Garcia-Vallve, Santi; Mulero, Miquel

    2011-07-01

    Detergent enzymes account for about 30% of the total worldwide production of enzymes and are one of the largest and most successful applications of modern industrial biotechnology. Proteases can improve the wash performance of household, industrial, and institutional laundry detergents used to remove protein-based stains such as blood, grass, body fluids, and food soils. This article describes two easy and cheap laboratory exercises to study the presence, profile, and basic enzymology of detergent proteases. These laboratory practicals are based on the determination of the detergent protease activity of various commercial detergents using the N-succinyl-L-alanyl-L-alanyl-L-prolyl-L-phenylalanine p-nitroanilide method and the bovine serum albumin degradation capacity. Students are also required to elucidate the enzymatic subtype of detergent proteases by studying the inhibitory potential of several types of protease inhibitors revealed by the same experimental methodology. Additionally, the results of the exercises can be used to provide additional insights on elementary enzymology by studying the influence of several important parameters on protease activity such as temperature (in this article) and the influence of pH and effects of surfactants and oxidizers (proposed). Students also develop laboratory skills, problem-solving capacities, and the ability to write a laboratory report. The exercises are mainly designed for an advanced undergraduate project in the biochemistry and biotechnology sciences. Globally, these laboratory practicals show students the biotechnological applications of proteases in the detergent industry and also reinforce important enzymology concepts.

  17. Distributed ultrafast fibre laser

    PubMed Central

    Liu, Xueming; Cui, Yudong; Han, Dongdong; Yao, Xiankun; Sun, Zhipei

    2015-01-01

    A traditional ultrafast fibre laser has a constant cavity length that is independent of the pulse wavelength. The investigation of distributed ultrafast (DUF) lasers is conceptually and technically challenging and of great interest because the laser cavity length and fundamental cavity frequency are changeable based on the wavelength. Here, we propose and demonstrate a DUF fibre laser based on a linearly chirped fibre Bragg grating, where the total cavity length is linearly changeable as a function of the pulse wavelength. The spectral sidebands in DUF lasers are enhanced greatly, including the continuous-wave (CW) and pulse components. We observe that all sidebands of the pulse experience the same round-trip time although they have different round-trip distances and refractive indices. The pulse-shaping of the DUF laser is dominated by the dissipative processes in addition to the phase modulations, which makes our ultrafast laser simple and stable. This laser provides a simple, stable, low-cost, ultrafast-pulsed source with controllable and changeable cavity frequency. PMID:25765454

  18. The Formation and Binding of Gold Nanoparticles onto Wool Fibres

    SciTech Connect

    Johnston, James H.; Burridge, Kerstin A.; Kelly, Fern M.

    2009-07-23

    This paper presents the novel use of nanosize gold with different plasmon resonance colours, as stable colourfast colourants on wool fibres for use in high quality fabrics and textiles. The gold nanoparticles are synthesised by the controlled reduction of Au{sup 3+} in the AuCl{sub 4}{sup -} complex to Au{sup 0} onto the surface of the wool where they attach to the S in the cystine amino acids in wool keratin proteins. Scanning electronmicroscopy shows the nanoparticles are present on the cuticles of the fibre surface and are concentrated at the edges of these cuticles. EDS analysis shows a strong correlation of Au with S and X-ray photoelectron spectroscopy suggests Au-S bond formation. Hence the nanogold colourants are chemically bound to the wool fibre surface and do not fade as traditional organic dyes do. A range of coloured fibres have been produced.

  19. The Formation and Binding of Gold Nanoparticles onto Wool Fibres

    NASA Astrophysics Data System (ADS)

    Johnston, James H.; Burridge, Kerstin A.; Kelly, Fern M.

    2009-07-01

    This paper presents the novel use of nanosize gold with different plasmon resonance colours, as stable colourfast colourants on wool fibres for use in high quality fabrics and textiles. The gold nanoparticles are synthesised by the controlled reduction of Au3+ in the AuCl4- complex to Au0 onto the surface of the wool where they attach to the S in the cystine amino acids in wool keratin proteins. Scanning electronmicroscopy shows the nanoparticles are present on the cuticles of the fibre surface and are concentrated at the edges of these cuticles. EDS analysis shows a strong correlation of Au with S and X-ray photoelectron spectroscopy suggests Au-S bond formation. Hence the nanogold colourants are chemically bound to the wool fibre surface and do not fade as traditional organic dyes do. A range of coloured fibres have been produced.

  20. Dietary fibre and colon cancer: epidemiologic and experimental evidence.

    PubMed Central

    Reddy, B S

    1980-01-01

    Epidemiologic studies have identified two dietary factors, a relatively high intake of fat and a relatively low intake of fibre, that are associated with colon cancer in humans. However, a recent study has shown a low risk of large bowel cancer in a rural Finnish population with a high dietary intake of fat, but also a high intake of fibre. Observations in humans and studies in animals have indicated that dietary fibre may protect against colon carcinogenesis by binding bile acids in the intestinal tract, by a direct effect on the colonic mucosa and by an indirect effect on the metabolism of carcinogens. The strength of protection varies with the type of fibre. PMID:6254626

  1. Enzymes, detergents and skin: facts and fantasies.

    PubMed

    Basketter, D A; English, J S C; Wakelin, S H; White, I R

    2008-06-01

    In their raw state, enzymes of bacterial/fungal origin cause allergic reactions in the lung. Proteolytic enzymes also cause irritation to skin, eyes and the respiratory tract. For 40 years, encapsulated enzymes have been used worldwide in detergent products, especially laundry formulations, and have increasing importance due to biodegradability and functionality at low temperatures, offering environmental benefits. Uniquely to the U.K., for years it has been suggested that the inclusion of enzymes in such products leads to adverse skin reactions, including erythema, pruritus and exacerbation of eczema. In this review, we look at the facts, asking whether there is evidence that the hazards identified for enzymes translate into any risk for consumer health. By considering the actual exposures in consumer use and exaggerated product usage, it is concluded that the irritating and allergenic hazards of enzyme raw materials do not translate into a risk of skin reactions, either irritant or allergic. Investigations of numerous individuals with skin complaints attributed to laundry products demonstrate convincingly that enzymes were not responsible. Indeed, enzyme-containing laundry products have an extensive history of safe use. Thus, the supposed adverse effects of enzymes on skin seem to be a consequence of a mythology. The important practical lesson is that when primary or secondary care practitioners are presented with a skin complaint, it should not be dismissed as a result of using an enzyme-containing laundry product as the diagnosis will certainly lie elsewhere. Education for healthcare professionals could usefully be enhanced to take this on board.

  2. Fibre Optic Probes For Ophthalmology

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    1986-09-01

    One of the most interesting fields of application of optical fibre technology is the medicine. Among other medical disciplines the field of ophthalmology is very interesting for these applications because of optical character of the organ of vision. After some remarks of a general nature, and concerning the needs of modern ophthalmology, we will review here our trials to apply optical fibre devices for the optical surgery, therapy and diagnosis in the ophthalmology. The devices include: optical fibre illuminators for the applications with operational probes (crioprobes, termal probes, a vitrotom etc.) and some of the diagnostic equipment (like Goldman lens etc.), optical fibre gradient microoptics for delivering of a laser beam to the appropriate internal structures of the eyeglobe, optical fibre lacrimaloscope for the screening of the lacrimal ducts and another one for the orbit. A general conception of the multitask fibre optic microprobe fcr ophthalmological applications - operations and diagnosis/1/ - concludes the work.

  3. Effect of the dietary fibre content of lifelong diet on colonic cellular proliferation in the rat.

    PubMed

    Edwards, C A; Wilson, R G; Hanlon, L; Eastwood, M A

    1992-08-01

    The effect of the fibre content of lifelong (18 months) diets on proximal and distal colonic cellular proliferation and short chain fatty acid (SCFA) content was investigated in 40 rats. Rats were fed a low fibre diet (17 g/kg non-starch polysaccharides NSP) or the stock diet (133 g/kg NSP). The higher fibre fed rats had increased caecal and colonic total contents (p < 0.001) and SCFAs than the low fibre fed rats (caecal SCFAs: higher fibre rats 96.4 (6.8) mumol/g wet weight v low fibre 22.7 (3.0): p < 0.001, colonic SCFAs: higher fibre 52.3 (3.1) mumol/g wet weight v low fibre 6.9 (2.2) mumol/g wet weight: p < 0.001). Cellular proliferation was increased in the proximal colon (bromodeoxyuridine labelling index, higher fibre 9.3 v low fibre 8.4 p < 0.05; flow cytometry, % cells in S phase higher fibre diet 7.9 v low fibre 6.9; p < 0.01) and there was a shift of proliferating cells to a higher region in each crypt. There was no significant difference in the percentage of cells in S phase in the distal colon of rats in both diet groups. The proliferative zone, however, was expanded in the distal colon of the higher fibre diet fed rats. This study indicates that long term higher fibre intake in rats is associated with a modest increase in cellular proliferation in the proximal colon but not the distal colon.

  4. Crystallization of the C-terminal head domain of the avian adenovirus CELO long fibre

    PubMed Central

    Guardado Calvo, Pablo; Llamas-Saiz, Antonio L.; Langlois, Patrick; van Raaij, Mark J.

    2006-01-01

    Avian adenovirus CELO contains two different fibres: fibre 1, the long fibre, and fibre 2, the short fibre. The short fibre is responsible for binding to an unknown avian receptor and is essential for infection of birds. The long fibre is not essential, but is known to bind the coxsackievirus and adenovirus receptor protein. Both trimeric fibres are attached to the same penton base, of which each icosahedral virus contains 12 copies. The short fibre extends straight outwards, while the long fibre emerges at an angle. The carboxy-terminal amino acids 579–793 of the avian adenovirus long fibre have been expressed with an amino-terminal hexahistidine tag and the expressed trimeric protein has been purified by nickel-affinity chromatography and crystallized. Crystals were grown at low pH using PEG 10 000 as precipitant and belonged to space group C2. The crystals diffracted rotating-anode Cu Kα radiation to at least 1.9 Å resolution and a complete data set was collected from a single crystal to 2.2 Å resolution. Unit-cell parameters were a = 216.5, b = 59.2, c = 57.5 Å, β = 101.3°, suggesting one trimer per asymmetric unit and a solvent content of 46%. The long fibre head does not have significant sequence homology to any other protein of known structure and molecular-replacement attempts with known fibre-head structures were unsuccessful. However, a map calculated using SIRAS phasing shows a clear trimer with a shape similar to known adenovirus fibre-head structures. Structure solution is in progress. PMID:16682773

  5. Mixing and Matching Detergents for Membrane Protein NMR Structure Determination

    SciTech Connect

    Columbus, Linda; Lipfert, Jan; Jambunathan, Kalyani; Fox, Daniel A.; Sim, Adelene Y.L.; Doniach, Sebastian; Lesley, Scott A.

    2009-10-21

    One major obstacle to membrane protein structure determination is the selection of a detergent micelle that mimics the native lipid bilayer. Currently, detergents are selected by exhaustive screening because the effects of protein-detergent interactions on protein structure are poorly understood. In this study, the structure and dynamics of an integral membrane protein in different detergents is investigated by nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy and small-angle X-ray scattering (SAXS). The results suggest that matching of the micelle dimensions to the protein's hydrophobic surface avoids exchange processes that reduce the completeness of the NMR observations. Based on these dimensions, several mixed micelles were designed that improved the completeness of NMR observations. These findings provide a basis for the rational design of mixed micelles that may advance membrane protein structure determination by NMR.

  6. Laundry detergents and skin irritancy--a comprehensive review.

    PubMed

    Crawford, Charles; Zirwas, Matthew J

    2014-01-01

    Surface-active agents (surfactants) form the foundation of an effective detergent formulation. As such, surfactants are a major component of laundry detergents. Depending on multiple factors, the amount of residual detergent surfactants in clothing after washing varies but may be sufficient to elicit skin irritation in susceptible individuals and in patients with existing dermatologic disorders. The goal of this review is to examine the relationship between surfactants commonly used in laundry detergent formulations and their potential for skin irritancy. In this context, the role of surfactants in achieving broad-spectrum cleaning performance in laundry is discussed, and currently available methodologies to evaluate and measure the effect of surfactant exposure on the skin are reviewed.

  7. Development of a tactile sensor for evaluation of detergents

    NASA Astrophysics Data System (ADS)

    Tsuchimi, Daisuke; Tanaka, Mami

    2007-12-01

    This paper is concerned with the development of a tactile sensor using PVDF (Polyvinylidene Fluoride) film as a receptor of the sensor to evaluate a detergent. Tactile sense is the most important sense in the sensation receptor of the human body along with eyesight. When the dish which washed cleanly is rubbed with a finger of human, good tactile sense and sound (vibration signal) like "Kyu-kyu" are obtained. From this tactile sense and sound, we judge that a dish becomes squeaky-clean. This tactile sense and sound are evaluation parameters when consumer selects a detergent. In this study, a tactile sensor using PVDF film as the receptor is fabricated. Sensory test of detergents was conducted. Measurement experiment by the sensor is carried out. Experiment results show that sensor output have good correlation with the result of human sensory test of detergent.

  8. Impact of detergent systems on bacterial survival on laundered fabrics.

    PubMed Central

    Jaska, J M; Fredell, D L

    1980-01-01

    The survival of Staphylococcus aureus was determined from inoculated swatches laundered in either a phosphate or a phosphate-substitute detergent. In a Plackett-Burman design study, the independent variables of detergent type, concentration, and variation, wash water temperature, soil load, cycle time, and water hardness were assigned high and low values. Wash water temperatures of 27, 38, 49, and 60 degrees C were employed. Viable bacteria were recovered from macerated swatches. Statistical analysis disclosed that there was no practical difference in the ability of phosphate or phosphate-substitute detergents to reduce the level of S. aureus on the laundered swatches in this controlled design. Analysis did reveal that water temperature was the most significant independent variables. The remaining variables did not appear to have any practical significance upon bacterial reduction. This bacteriological study did not evaluate other essential detergent properties. PMID:7377775

  9. Sulphur-doped silica fibres

    SciTech Connect

    Gerasimova, V I; Rybaltovskii, A O; Chernov, P V; Mashinsky, V M; Sazhin, O D; Medvedkov, O I; Rybaltovsky, A A; Khrapko, R R

    2003-01-31

    An optical fibre with low optical losses is manufactured from a sulphur-doped quartz glass. Optical absorption spectra are measured for various parts of the fibre core. Most of the bands of these spectra are assigned to oxygen-deficient centres and colour centres containing sulphur atoms. The photosensitivity of glasses exposed to laser radiation at wavelengths of 193 and 244 nm is investigated to estimate the possibility of their application for producing photorefracting devices. A Bragg grating of the refractive index with {Delta}n = 7.8 x 10{sup -4} is written in a sulphur-doped silica fibre. (fibre optics)

  10. Differential effects of detergents on keratinocyte gene expression.

    PubMed

    van Ruissen, F; Le, M; Carroll, J M; van der Valk, P G; Schalkwijk, J

    1998-04-01

    We have studied the effect of various detergents on keratinocyte gene expression in vitro, using an anionic detergent (sodium dodecyl sulfate), a cationic detergent cetyltrimethylammoniumbromide (CTAB), and two nonionic detergents, Nonidet P-40 and Tween-20. We measured the effect of these detergents on direct cellular toxicity (lactate dehydrogenase release), on the expression of markers for normal differentiation (cytokeratin 1 and involucrin expression), and on disturbed keratinocyte differentiation (SKALP) by northern blot analysis. As reported in other studies, large differences were noted in direct cellular toxicity. In a culture model that mimics normal epidermal differentiation we found that low concentrations of sodium dodecyl sulfate could induce the expression of SKALP, a proteinase inhibitor that is not normally expressed in human epidermis but is found in hyperproliferative skin. Sodium dodecyl sulfate caused upregulation of involucrin and downregulation of cytokeratin 1 expression, which is associated with the hyperproliferative/inflammatory epidermal phenotype found in psoriasis, wound healing, and skin irritation. These changes were not induced after treatment of cultures with CTAB, Triton X-100, and Nonidet-P40. This effect appeared to be specific for the class of anionic detergents because sodium dodecyl benzene sulfonate and sodium laurate also induced SKALP expression. These in vitro findings showed only a partial correlation with the potential of different detergents to induce clinical, biophysical, and cell biologic changes in vivo in human skin. Both sodium dodecyl sulfate and CTAB were found to cause induction and upregulation of SKALP and involucrin at low doses following a 24 h patch test, whereas high concentrations of Triton X-100 did not. Sodium dodecyl sulfate induced higher rates of transepidermal water loss, whereas CTAB treated skin showed more signs of cellular toxicity. We conclude that the action of anionic detergents on

  11. Quinoa (Chenopodium quinoa W.) and amaranth (Amaranthus caudatus L.) provide dietary fibres high in pectic substances and xyloglucans.

    PubMed

    Lamothe, Lisa M; Srichuwong, Sathaporn; Reuhs, Bradley L; Hamaker, Bruce R

    2015-01-15

    Dietary fibre of quinoa and amaranth was analysed for its insoluble and soluble fibre content, composition, and structure. Total dietary fibre content was 10% for quinoa and 11% for amaranth. For both pseudocereals, 78% of its dietary fibre was insoluble. Insoluble fibre (IDF) from quinoa and amaranth was mainly composed of galacturonic acid, arabinose, galactose, xylose and glucose. Linkage analysis indicated that IDF was composed of homogalacturonans and rhamnogalacturonan-I with arabinan side-chains (∼55-60%), as well as highly branched xyloglucans (∼30%) and cellulose. For both pseudocereals, 22% of total dietary fibre was soluble; a higher proportion than that found in wheat and maize (∼15%). The soluble fibre (SDF) was composed of glucose, galacturonic acid and arabinose; for amaranth, xylose was also a major constituent. Xyloglucans made up ∼40-60% of the SDF and arabinose-rich pectic polysaccharides represented ∼34-55%.

  12. Quinoa (Chenopodium quinoa W.) and amaranth (Amaranthus caudatus L.) provide dietary fibres high in pectic substances and xyloglucans.

    PubMed

    Lamothe, Lisa M; Srichuwong, Sathaporn; Reuhs, Bradley L; Hamaker, Bruce R

    2015-01-15

    Dietary fibre of quinoa and amaranth was analysed for its insoluble and soluble fibre content, composition, and structure. Total dietary fibre content was 10% for quinoa and 11% for amaranth. For both pseudocereals, 78% of its dietary fibre was insoluble. Insoluble fibre (IDF) from quinoa and amaranth was mainly composed of galacturonic acid, arabinose, galactose, xylose and glucose. Linkage analysis indicated that IDF was composed of homogalacturonans and rhamnogalacturonan-I with arabinan side-chains (∼55-60%), as well as highly branched xyloglucans (∼30%) and cellulose. For both pseudocereals, 22% of total dietary fibre was soluble; a higher proportion than that found in wheat and maize (∼15%). The soluble fibre (SDF) was composed of glucose, galacturonic acid and arabinose; for amaranth, xylose was also a major constituent. Xyloglucans made up ∼40-60% of the SDF and arabinose-rich pectic polysaccharides represented ∼34-55%. PMID:25149016

  13. Retention of Cationic Starch onto Cellulose Fibres

    NASA Astrophysics Data System (ADS)

    Missaoui, Mohamed; Mauret, Evelyne; Belgacem, Mohamed Naceur

    2008-08-01

    Three methods of cationic starch titration were used to quantify its retention on cellulose fibres, namely: (i) the complexation of CS with iodine and measurement of the absorbency of the ensuing blue solution by UV-vis spectroscopy; (ii) hydrolysis of the starch macromolecules followed by the conversion of the resulting sugars to furan-based molecules and quantifying the ensuing mixture by measuring their absorbance at a Ι of 490 nm, using the same technique as previous one and; finally (iii) hydrolysis of starch macromolecules by trifluoro-acetic acid and quantification of the sugars in the resulting hydrolysates by high performance liquid chromatography. The three methods were found to give similar results within the range of CS addition from 0 to 50 mg per g of cellulose fibres.

  14. 40 CFR 80.156 - Liability for violations of the interim detergent program controls and prohibitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... CFR part 79 registration, and must also accurately identify if the detergent, at that concentration... interim detergent program controls and prohibitions. 80.156 Section 80.156 Protection of Environment... Detergent Gasoline § 80.156 Liability for violations of the interim detergent program controls...

  15. 40 CFR 80.156 - Liability for violations of the interim detergent program controls and prohibitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... CFR part 79 registration, and must also accurately identify if the detergent, at that concentration... interim detergent program controls and prohibitions. 80.156 Section 80.156 Protection of Environment... Detergent Gasoline § 80.156 Liability for violations of the interim detergent program controls...

  16. 40 CFR 80.156 - Liability for violations of the interim detergent program controls and prohibitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... CFR part 79 registration, and must also accurately identify if the detergent, at that concentration... interim detergent program controls and prohibitions. 80.156 Section 80.156 Protection of Environment... Detergent Gasoline § 80.156 Liability for violations of the interim detergent program controls...

  17. EFFECT OF DETERGENT ON ELECTRICAL PROPERTIES OF SQUID AXON MEMBRANE.

    PubMed

    KISHIMOTO, U; ADELMAN, W J

    1964-05-01

    The effects of detergents on squid giant axon action and resting potentials as well as membrane conductances in the voltage clamp have been studied. Anionic detergents (sodium lauryl sulfate, 0.1 to 1.0 mM; dimethyl benzene sulfonate, 1 to 20 mM, pH 7.6) cause a temporary increase and a later decrease of action potential height and the value of the resting potential. Cationic detergent (cetyl trimethyl ammonium chloride, 6 x 10(-5)M or more, pH 7.6) generally brings about immediate and irreversible decreases in the action and resting potentials. Non-ionic detergent (tween 80, 0.1 M, pH 7.6) causes a slight reversible reduction of action potential height without affecting the value of the resting potential. Both anionic and cationic detergents generally decrease the sodium and potassium conductances irreversibly. The effect of non-ionic detergent is to decrease the sodium conductance reversibly, leaving the potassium conductance almost unchanged.

  18. Laundry detergent compatibility of the alkaline protease from Bacillus cereus.

    PubMed

    Banik, Rathindra Mohan; Prakash, Monika

    2004-01-01

    The endogenous protease activity in various commercially available laundry detergents of international companies was studied. The maximum protease activity was found at 50 degrees C in pH range 10.5-11.0 in all the tested laundry detergents. The endogenous protease activity in the tested detergents retained up to 70% on incubation at 40 degrees C for 1 h, whereas less than 30% activity was only found on incubation at 50 degrees C for 1 h. The alkaline protease from an alkalophilic strain of Bacillus cereus was studied for its compatibility in commercial detergents. The cell free fermented broth from shake flask culture of the organism showed maximum activity at pH 10.5 and 50 degrees C. The protease from B. cereus showed much higher residual activity (more than 80%) on incubation with laundry detergents at 50 degrees C for 1 h or longer. The protease enzyme from B. cereus was found to be superior over the endogenous proteases present in the tested commercial laundry detergents in comparison to the enzyme stability during the washing at higher temperature, e.g., 40-50 degrees C.

  19. [Level of blood serum lipids in rats treated with detergents].

    PubMed

    Szymaniec, J; Trzeciak, H I; Machalska, H; Turczyński, B

    1977-01-01

    Male Wistar rats were treated intraperitoneally once per week for 12 weeks with following detergents: Olbrotol-18 (nonionic detergent), a product of etheric condensation of 18 moles of ethylene oxide to 1 mole of the mixture of olein alcohol and cetyl alkohol in ratio 1:1, in a dose of 10 mg/kg; SBO (anionic detergent), sodium 2-ethylhexylsulfosuccinate, in a dose of 10 mg/kg and Sterinol (cationic detergent), benzalkonium bromide, in a dose of 0.6 mg/kg. The control rats were injected with 0.9% saline solution. The content of total cholesterol, beta-lipoproteins and total lipids in serum were estimated. The increase of total cholesterol and the decrease of beta-lipoproteins content in serum of rats after all used detergents were observed as compared with the control. The increase of total lipid content only after long-term treatment with Olbrotol-18 was found. It is concluded that long term intraperitoneal treatment with detergents changes similarly the contents of total cholesterol and of beta-lipoproteins in blood serum of rats.

  20. Toxicity and detoxification of Swedish detergents and softener products.

    PubMed

    Pettersson, A; Adamsson, M; Dave, G

    2000-11-01

    Detergents and softeners are used in large quantities and some of their ingredients are highly toxic to aquatic organisms. In the present study the acute toxicity to Daphnia magna was determined for 26 detergents and five softener Swedish products. Only one of the detergents had a 48-h EC50 > 100 mg/l. The 48-h EC50 for the other 25 detergents ranged from 4 to 85 mg/l. The 48-h EC50 for the five softeners ranged from 15 to 166 mg/l. Detoxification tests, with and without inoculum of sewage organisms, showed that all tested products were detoxified to some extent after 16 days and that the rate of detoxification was considerably higher with addition of sewage organisms. Toxicity to D. magna of the detergents and softeners, and the biotic detoxification rate was correlated with the concentration of surfactants used in formulating the products (more surfactants increased toxicity and a slower rate of detoxification). These results emphasize the importance of biological purification of domestic wastewater containing detergents and a suggested development of less toxic and more easily degradable surfactants.

  1. Effects of wastewater sludge and its detergents on the stability of rotavirus

    SciTech Connect

    Ward, R.L.; Ashley, C.S.

    1980-06-01

    Wastewater sludge reduced the heat required to inactivate rotavirus SA-11, and ionic detergents were identified as the sludge components responsible for this effect. A similar result was found previously with reovirus. The quantitative effects of individual ionic detergents on rotavirus and reovirus were very different, and rotavirus was found to be extremely sensitive to several of these detergents. However, neither virus was destabilized by nonionic detergents. On the contrary, rotavirus was stabilized by a nonionic detergent against the potent destabilizing effects of the ionic detergent sodium dodecyl sulfate. The destabilizing effects of both cationic and anionic detergents on rotavirus were greatly altered by changes in the pH of the medium.

  2. Effect of high fibre diets formulated with different fibrous ingredients on performance, nutrient digestibility and faecal microbiota of weaned piglets.

    PubMed

    Yu, Cangyou; Zhang, Shihai; Yang, Qing; Peng, Qian; Zhu, Jinlong; Zeng, Xiangfang; Qiao, Shiyan

    2016-08-01

    The aim of the experiment on 180 weaned piglets (8.9 kg body weight) was to investigate the influence of high fibre diets formulated with different fibrous ingredients on performance, nutrient digestibility, diarrhoea incidence and numbers of faecal microbiota. The dietary treatments included a Control diet and five high fibre diets formulated with different fibre sources including wheat bran, soybean hulls, naked oat hulls, palm kernel expeller and bamboo fibre. The high fibre diets averaged 14.6% neutral detergent fibre with different non-starch polysaccharides (NSP) components and were fed ad libitum for 28 d. Faecal samples were collected during the last 3 d of the experiment and the apparent total tract digestibility of nutrients and fibre components were determined. Pigs fed the Control and wheat bran diets had a higher (p ≤ 0.05) average daily gain (ADG) than pigs fed the palm kernel expeller and bamboo meal diets. The reduced ADG for pigs appeared to be related to reductions in the digestibility of gross energy and dry matter, respectively. The feed-to-gain ratio was significantly higher (p ≤ 0.05) for pigs fed the fibre diets. The digestibility of NSP components was different among the treatments. The diarrhoea incidence was not affected by treatments. The abundance of faecal bifidobacteria was significantly higher (p ≤ 0.05) for pigs fed the wheat bran diet than for pigs fed the bamboo meal diet. It was concluded that the diets formulated with different fibre sources when fed to weaned piglets have different effects on pig performance, nutrient digestibility and numbers of faecal microbiota. The wheat bran diet rich in arabinoxylans enabled a better performance than the other tested diets with fibre addition. PMID:27216554

  3. Applications for carbon fibre recovered from composites

    NASA Astrophysics Data System (ADS)

    Pickering; Liu, Z.; Turner, TA; Wong, KH

    2016-07-01

    Commercial operations to recover carbon fibre from waste composites are now developing and as more recovered fibre becomes available new applications for recovered fibre are required. Opportunities to use recovered carbon fibre as a structural reinforcement are considered involving the use of wet lay processes to produce nonwoven mats. Mats with random in-plane fibre orientation can readily be produced using existing commercial processes. However, the fibre volume fraction, and hence the mechanical properties that can be achieved, result in composites with limited mechanical properties. Fibre volume fractions of 40% can be achieved with high moulding pressures of over 100 bar, however, moulding at these pressures results in substantial fibre breakage which reduces the mean fibre length and the properties of the composite manufactured. Nonwoven mats made from aligned, short carbon fibres can achieve higher fibre volume fractions with lower fibre breakage even at high moulding pressure. A process for aligning short fibres is described and a composite of over 60% fibre volume fraction has been manufactured at a pressures up to 100 bar with low fibre breakage. Further developments of the alignment process have been undertaken and a composite of 46% fibre volume fraction has been produced moulded at a pressure of 7 bar in an autoclave, exhibiting good mechanical properties that compete with higher grade materials. This demonstrates the potential for high value applications for recovered carbon fibre by fibre alignment.

  4. Detergent decellularization of heart valves for tissue engineering: toxicological effects of residual detergents on human endothelial cells.

    PubMed

    Cebotari, Serghei; Tudorache, Igor; Jaekel, Thomas; Hilfiker, Andres; Dorfman, Suzanne; Ternes, Waldemar; Haverich, Axel; Lichtenberg, Artur

    2010-03-01

    Detergents are powerful agents for tissue decellularization. Despite this, the high toxicity of detergent residua can be a major limitation. This study evaluated the efficacy of detergent removal from decellularized pulmonary valves (PVs) and the consequences of repopulation with human endothelial cells (HECs). Porcine PVs were treated with 1% sodium deoxycholate (SDC), group A; 1% sodium dodecyl sulfate (SDS), group B; and a mixture of 0.5% SDC/0.5% SDS, group C (n = 5 each). After each of 10 succeeding wash cycles (WCs), samples of the washing solution (WS) were analyzed by solid phase extraction and high performance liquid chromatography for the presence of detergents. Metabolic activity of HEC was also assessed in the WS samples (cytotoxicity and MTS assays). Decellularized and washed PVs were reseeded with HEC. Histological analysis demonstrated efficient tissue decellularization in all groups. Detergents' concentration in all WSs decreased exponentially and was below 50 mg/L after 6, 8, and 4 WCs in groups A, B, and C, respectively. This concentration resulted in no significant toxic influence on cell cultures, and scaffolds could be efficiently reseeded with HEC. In conclusion, intensive washing of detergent decellularized valvular scaffolds lowers the residual contamination below a hazardous threshold and allows their successful repopulation with HEC for tissue engineering purposes.

  5. An enzyme histochemical study of large muscle fibres in the neonatal mouse.

    PubMed Central

    Christie, K N; Stewart, R J; Bacciocchi, G

    1990-01-01

    Small clusters of extra large muscle fibres were identified in hindlimb muscles of neonatal mice (strain C57BL/10ScSn). At two days of age they had a significantly greater cross-sectional area than their normal counterparts (P less than 0.01). Fibre typing methods (NADH-tetrazolium reductase, ATPase and phosphorylase) classified them as 2A fast oxidative glycolytic (FOG fibres). The activity of NADH-tetrazolium reductase and the lysosomal enzymes beta-glucuronidase, acid phosphatase and dipeptidyl peptidase II were all elevated in the large fibres. Microsomal aminopeptidase (mAPP), a membrane-bound enzyme, also showed increased activity. The fibres are probably the mouse equivalent of the Wohlfart B fibres of the human fetus, with which comparison is made. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Figs. 9-10 PMID:2254160

  6. Differential distribution of proteins and lipids in detergent-resistant and detergent-soluble domains in rod outer segment plasma membranes and disks

    PubMed Central

    Elliott, Michael H.; Nash, Zack A.; Takemori, Nobuaki; Fliesler, Steven J.; McClellan, Mark E.; Naash, Muna I.

    2009-01-01

    Membrane heterogeneity plays a significant role in regulating signal transduction and other cellular activities. We examined the protein and lipid components associated with the detergent-resistant membrane (DRM) fractions from retinal rod outer segment (ROS) disk and plasma membrane-enriched preparations. Proteomics and correlative western blot analysis revealed the presence of α and β subunits of the rod cGMP-gated ion channel and glucose transporter type 1, among other proteins. The glucose transporter was present exclusively in ROS plasma membrane (not disks) and was highly enriched in DRMs, as was the cGMP-gated channel β-subunit. In contrast, the majority of rod opsin and ATP-binding cassette transporter A4 was localized to detergent-soluble domains in disks. As expected, the cholesterol: fatty acid mole ratio was higher in DRMs than in the corresponding parent membranes (disk and plasma membranes, respectively) and was also higher in disks compared to plasma membranes. Furthermore, the ratio of saturated: polyunsaturated fatty acids was also higher in DRMs compared to their respective parent membranes (disk and plasma membranes). These results confirm that DRMs prepared from both disks and plasma membranes are enriched in cholesterol and in saturated fatty acids compared to their parent membranes. The dominant fatty acids in DRMs were 16: 0 and 18: 0; 22: 6n3 and 18: 1 levels were threefold higher and twofold lower, respectively, in disk-derived DRMs compared to plasma membrane-derived DRMs. We estimate, based on fatty acid recovery that DRMs account for only ~ 8% of disks and ~ 12% of ROS plasma membrane. PMID:17944869

  7. Raman studies of gluten proteins aggregation induced by dietary fibres.

    PubMed

    Nawrocka, Agnieszka; Szymańska-Chargot, Monika; Miś, Antoni; Kowalski, Radosław; Gruszecki, Wiesław I

    2016-03-01

    Interactions between gluten proteins and dietary fibre preparations are crucial in the baking industry. The addition of dietary fibre to bread causes significant reduction in its quality which is influenced by changes in the structure of gluten proteins. Fourier transform Raman spectroscopy was applied to determine changes in the structure of gluten proteins modified by seven dietary fibres. The commercially available gluten proteins without starch were mixed with the fibres in three concentrations: 3%, 6% and 9%. The obtained results showed that all fibres, regardless of their origin, caused the same kind of changes i.e. decrease in the α-helix content with a simultaneous increase in the content of antiparallel-β-sheet. The results indicated that presence of cellulose was the probable cause of these changes, and lead to aggregation or abnormal folding of the gluten proteins. Other changes observed in the gluten structure concerning β-structures, conformation of disulphide bridges, and aromatic amino acid environment, depended on the fibres chemical composition.

  8. Monomode Fibre Optic Interferometric Sensors.

    NASA Astrophysics Data System (ADS)

    Leilabady, P. Akhavan

    Available from UMI in association with The British Library. Optical fibre sensors are playing an increasingly important role in industrial, medical and military application. Not only are conventional electrically based sensors being gradually replaced by their fibre optic analogues, but also fibre optic sensors are being deployed in special applications where electrically based sensors are unsuitable. Their immunity to electromagnetic interference and inherent high measurement resolution give optical fibre sensors an advantage in diverse applications, including the aerospace and power generation industry and in medicine. The theme of this thesis is interferometric techniques for the recovery of measurand induced modulations of the the fibre guided optical beam. Interferometry offers high measurement resolutions, which makes it the preferred choice for optical processing in certain sensor systems. Interferometric techniques developed for the recovery of the optical phase, polarisation ellipticity and polarisation azimuth are described. However, there are a number of problems, such as the very limited operating range and long term stability that hinder practical implementation of interferometric sensors. These problems are addressed and novel optical processing circuitry based on interferometric detection of phase and polarisation state are introduced which facilitates the development of practical all fibre sensors. Our discussions will start by a general overview of the fibre optic sensor technology, Chapter 1, introducing the principle of sensing by light and the three major categories of fibre optic sensors; multimode fibre intensity modulated sensors, monomode fibre phase modulated sensors and birefringent fibre polarisation state modulated sensors. In Chapter 3, the category of sensors based on phase modulation is addressed describing research carried out into developing an all-fibre optic vortex shedding flowmeter, illustrating interferometric techniques for

  9. Speciality optical fibres for astronomy

    NASA Astrophysics Data System (ADS)

    Ellis, S. C.; Bland-Hawthorn, J.

    2015-05-01

    Astrophotonics is a rapidly developing area of research which applies photonic technology to astronomical instrumentation. Such technology has the capability of significantly improving the sensitivity, calibration and stability of astronomical instruments, or indeed providing novel capabilities which are not possible using classical optics. We review the development and application of speciality fibres for astronomy, including multi-mode to single-mode converters, notch filters and frequency combs.In particular we focus on our development of instruments designed to filter atmospheric emission lines to enable much deeper spectroscopic observations in the near-infrared. These instruments employ two novel photonic technologies. First, we have developed complex aperiodic fibre Bragg gratings which filter over 100 irregularly spaced wavelengths in a single device, covering a bandwidth of over 200 nm. However, astronomical instruments require highly multi-mode fibres to enable sufficient coupling into the fibre, since atmospheric turbulence heavily distorts the wavefront. But photonic technologies such as fibre Bragg gratings, require single mode fibres. This problem is solved by the photonic lantern, which enables efficient coupling from a multi-mode fibre to an array of single-mode fibres and vice versa. We present the results of laboratory tests of these technologies and of on-sky experiments made using the first instruments to deploy these technologies on a telescope. These tests show that the fibre Bragg gratings suppress the night sky background by a factor of 9. Current instruments are limited by thermal and detector emission. Planned instruments should improve the background suppression even further, by optimising the design of the spectrograph for the properties of the photonic components. Finally we review ongoing research in astrophotonics, including multi-moded multicore fibre Bragg gratings, which enable multiple gratings to be written into the same device

  10. Reticulation des fibres lignocellulosiques

    NASA Astrophysics Data System (ADS)

    Landrevy, Christel

    Pour faire face à la crise économique la conception de papier à valeur ajoutée est développée par les industries papetières. Le but de se projet est l'amélioration des techniques actuelles de réticulation des fibres lignocellulosiques de la pâte à papier visant à produire un papier plus résistant. En effet, lors des réactions de réticulation traditionnelles, de nombreuses liaisons intra-fibres se forment ce qui affecte négativement l'amélioration anticipée des propriétés physiques du papier ou du matériau produit. Pour éviter la formation de ces liaisons intra-fibres, un greffage sur les fibres de groupements ne pouvant pas réagir entre eux est nécessaire. La réticulation des fibres par une réaction de « click chemistry » appelée cycloaddition de Huisgen entre un azide et un alcyne vrai, catalysée par du cuivre (CuAAC) a été l'une des solutions trouvée pour remédier à ce problème. De plus, une adaptation de cette réaction en milieux aqueux pourrait favoriser son utilisation en milieu industriel. L'étude que nous désirons entreprendre lors de ce projet vise à optimiser la réaction de CuAAC et les réactions intermédiaires (propargylation, tosylation et azidation) sur la pâte kraft, en milieu aqueux. Pour cela, les réactions ont été adaptées en milieu aqueux sur la cellulose microcristalline afin de vérifier sa faisabilité, puis transférée à la pâte kraft et l'influence de différents paramètres comme le temps de réaction ou la quantité de réactifs utilisée a été étudiée. Dans un second temps, une étude des différentes propriétés conférées au papier par les réactions a été réalisée à partir d'une série de tests papetiers optiques et physiques. Mots Clés Click chemistry, Huisgen, CuAAC, propargylation, tosylation, azidation, cellulose, pâte kraft, milieu aqueux, papier.

  11. Chronological ageing of human hair keratin fibres.

    PubMed

    Thibaut, S; de Becker, E; Bernard, B A; Huart, M; Fiat, F; Baghdadli, N; Luengo, G S; Leroy, F; Angevin, P; Kermoal, A M; Muller, S; Peron, M; Provot, G; Kravtchenko, S; Saint-Léger, D; Desbois, G; Gauchet, L; Nowbuth, K; Galliano, A; Kempf, J Y; Silberzan, I

    2010-12-01

    Examination of very long hair (length > 2.4 m) using a large range of evaluation methods including physical, chemical, biochemical and microscopic techniques has enabled to attain a detailed understanding of natural ageing of human hair keratin fibres. Scrutinizing hair that has undergone little or no oxidative aggression--because of the absence of action of chemical agents such as bleaching or dyeing--from the root to the tip shows the deterioration process, which gradually takes place from the outside to the inside of the hair shaft: first, a progressive abrasion of the cuticle, whilst the cortex structure remains unaltered, is evidenced along a length of roughly 1 m onwards together with constant shine, hydrophobicity and friction characteristics. Further along the fibre, a significant damage to cuticle scales occurs, which correlates well with ceramides and 18-Methyl Eicosanoic Acid (18-MEA) decline, and progressive decrease in keratin-associated protein content. Most physical descriptors of mechanical and optical properties decay significantly. This detailed description of natural ageing of human hair fibres by a fine analysis of hair components and physical parameters in relationship with cosmetic characteristics provides a time-dependent 'damage scale' of human hair, which may help in designing new targeted hair care formulations.

  12. Automated continuous flow determination of urine albumin by competition with dye-detergent binding.

    PubMed

    Lever, M; Walmsley, T A

    1978-02-15

    A continuous flow automated method for urine albumin was developed based on the ability of albumin to displace bromophenol blue from a bromophenol blue detergent complex. The method is almost specific for albumin, giving a slight response with an alpha-globulin fraction from serum. Results agreed closely with rocket electrophoresis albumin estimates on urine samples, but significantly less closely with "total urine protein" estimates by an acid protein precipitation, followed by biuret colour reaction, procedure. This method is being used to replace the indefinite "total protein" test for most routine purposes.

  13. Sulfation of chondroitin. Specificity, degree of sulfation, and detergent effects with 4-sulfating and 6-sulfating microsomal systems

    SciTech Connect

    Sugumaran, G.; Silbert, J.E.

    1988-04-05

    Microsomal preparations from chondroitin 6-sulfate-producing chick embryo epiphyseal cartilage, and from chondroitin 4-sulfate-producing mouse mastocytoma cells, were incubated with UDP-(14C)glucuronic acid and UDP-N-acetylgalactosamine to form non-sulfated proteo(14C)chondroitin. Aliquots of the incubations were then incubated with 3'-phosphoadenylylphosphosulfate (PAPS) in the presence or absence of various detergents. In the absence of detergents, there was good sulfation of this endogenous proteo(14C)chondroitin by the original microsomes from both sources. Detergents, with the exception of Triton X-100, markedly inhibited sulfation in the mast cell system but not in the chick cartilage system. These results indicate that sulfation and polymerization are closely linked on cell membranes and that in some cases this organization can be disrupted by detergents. When aliquots of the original incubation were heat inactivated, and then reincubated with new microsomes from chick cartilage and/or mouse mastocytoma cells plus PAPS, there was no significant sulfation of this exogenous proteo(14C) chondroitin with either system unless Triton X-100 was added. Sulfation of exogenous chondroitin and chondroitin hexasaccharide was compared with sulfation of endogenous and exogenous proteo(14C)chondroitin. Sulfate incorporation into hexasaccharide and chondroitin decreased as their concentrations (based on uronic acid) approached that of the proteo(14C)chondroitin. At the same time, the degree of sulfation in percent of substituted hexosamine increased. However, the degree of sulfation did not reach that of the endogenous proteo(14C)chondroitin. Hexasaccharide and chondroitin sulfation were stimulated by the presence of Triton X-100. However, in contrast to the exogenous proteo(14C)chondroitin, there was some sulfation of hexasaccharide and chondroitin in the absence of this detergent.

  14. Bacterial profile from caecal contents and soft faeces in growing rabbits given diets differing in soluble and insoluble fibre levels.

    PubMed

    Rodríguez-Romero, Norelys; Abecia, Leticia; Fondevila, Manuel

    2012-12-01

    To verify if non-invasive collection of soft faeces (SF) from rabbits can be used as an index of bacterial biodiversity in caecal contents (CC), 24 weaned rabbits were given diets with low (LI) and high (HI) levels of insoluble fibre (neutral detergent fibre, NDF) and low (LS) and high (HS) levels of soluble fibre (neutral detergent soluble fibre, NDSF). After 21 days, animals were fitted with neck collars for SF collection. Two days later, animals were slaughtered and CC sampled. Total bacterial concentration quantified by real time PCR (log(10) ng DNA/mg DM) was higher in SF than CC (2.615 vs. 2.383). Among diets, in CC it was (P = 0.059) lowest in LILS diet, whereas in SF it decreased (P = 0.025) with the NDF level. DGGE profiles showed that structure of bacterial communities of SF was close to that of CC; however, similarity was higher in LI than HI diets (0.82 vs. 0.74). Diversity indexes in CC decreased with NDSF (P < 0.05), whereas the effect of NDF (P < 0.05) was also appreciated in SF. Soft faeces can be an alternative to surgery or slaughter techniques to monitor changes in caecal bacterial community; however, high dietary NDF may decrease similarity between both communities.

  15. Fibre laser based on tellurium-doped active fibre

    SciTech Connect

    Alyshev, S V; Ryumkin, K E; Shubin, A V; Medvedkov, O I; Dianov, E M; Khopin, V F; Gur'yanov, A N

    2014-02-28

    We have studied the lasing properties of tellurium-doped germanosilicate fibre, identified its gain and excited-state absorption bands, and assessed the effect of cooling to low temperature (77 K) on the bands. The excitation spectrum of the near-IR luminescence in the fibre has been measured. Lasing at 1.55 mm has been demonstrated for the first time in this gain medium at liquidnitrogen temperature and pump wavelengths of 1.064 and 1.085 mm. The measured Raman spectrum of the fibre provides some insight into the structure of the near-IR luminescence centre. (letters)

  16. Lipids that determine detergent resistance of MDCK cell membrane fractions.

    PubMed

    Manni, Marco M; Cano, Ainara; Alonso, Cristina; Goñi, Félix M

    2015-10-01

    A comparative lipidomic study has been performed of whole Madin-Darby canine kidney epithelial cells and of the detergent-resistant membrane fraction (DRM) obtained after treating the cells with the non-ionic detergent Triton X-100. The DRM were isolated following a standard procedure that is extensively used in cell biology studies. Significant differences were found in the lipid composition of the whole cells and of DRM. The latter were enriched in all the analyzed sphingolipid classes: sphingomyelins, ceramides and hexosylceramides. Diacylglycerols were also preferentially found in DRM. The detergent-resistant fraction was also enriched in saturated over unsaturated fatty acyl chains, and in sn-1 acyl chains containing 16 carbon atoms, over the longer and shorter ones. The glycerophospholipid species phosphatidylethanolamines and phosphatidylinositols, that were mainly unsaturated, did not show a preference for DRM. Phosphatidylcholines were an intermediate case: the saturated, but not the unsaturated species were found preferentially in DRM. The question remains on whether these DRM, recovered from detergent-membrane mixtures by floatation over a sucrose gradient, really correspond to membrane domains existing in the cell membrane prior to detergent treatment.

  17. Lipids that determine detergent resistance of MDCK cell membrane fractions.

    PubMed

    Manni, Marco M; Cano, Ainara; Alonso, Cristina; Goñi, Félix M

    2015-10-01

    A comparative lipidomic study has been performed of whole Madin-Darby canine kidney epithelial cells and of the detergent-resistant membrane fraction (DRM) obtained after treating the cells with the non-ionic detergent Triton X-100. The DRM were isolated following a standard procedure that is extensively used in cell biology studies. Significant differences were found in the lipid composition of the whole cells and of DRM. The latter were enriched in all the analyzed sphingolipid classes: sphingomyelins, ceramides and hexosylceramides. Diacylglycerols were also preferentially found in DRM. The detergent-resistant fraction was also enriched in saturated over unsaturated fatty acyl chains, and in sn-1 acyl chains containing 16 carbon atoms, over the longer and shorter ones. The glycerophospholipid species phosphatidylethanolamines and phosphatidylinositols, that were mainly unsaturated, did not show a preference for DRM. Phosphatidylcholines were an intermediate case: the saturated, but not the unsaturated species were found preferentially in DRM. The question remains on whether these DRM, recovered from detergent-membrane mixtures by floatation over a sucrose gradient, really correspond to membrane domains existing in the cell membrane prior to detergent treatment. PMID:26320877

  18. Effects of Detergents on Ribosomal Precursor Subunits of Bacillus megaterium

    PubMed Central

    Body, Barbara A.; Brownstein, Bernard H.

    1978-01-01

    Cell extracts prepared by osmotic lysis of protoplasts were analyzed by sucrose gradient sedimentation. In the absence of detergents, ribosomal precursor particles were found in a gradient fraction which sedimented faster than mature 50S subunits and in two other fractions coincident with mature 50S and 30S ribosomal subunits. Phospholipid, an indicator of membrane, was shown to be associated with only the fastest-sedimenting ribosomal precursor particle fraction. After the extracts were treated with detergents, all phospholipid was found at the top of the gradients. Brij 58, Triton X-100, and Nonidet P-40 did not cause a change in the sedimentation values of precursors; however, the detergents deoxycholate or LOC (Amway Corp.) disrupted the fastest-sedimenting precursor and converted the ribosomal precursor subunits which sedimented at the 50S and 30S positions to five different classes of more slowly sedimenting particles. Earlier reports on the in vivo assembly of ribosomal subunits have shown that several stages of ribosomal precursor subunits exist, and, in the presence of the detergents deoxycholate and LOC, which had been used to prepare cell extracts, the precursors sedimented more slowly. Our data are consistent with the hypothesis that those detergents selectively modify the structure of ribosomal precursors and lend further support to the hypothesis that the in vivo ribosomal precursor subunits have 50S and 30S sedimentation values. In addition, these data support the idea that the ribosomal precursor particles found in the fast-sedimenting fraction may constitute a unique precursor fraction. PMID:412833

  19. Effects of detergents on ribosomal precursor subunits of Bacillus megaterium.

    PubMed

    Body, A; Brownstein, B H

    1978-01-01

    Cell extracts prepared by osmotic lysis of protoplasts were analyzed by sucrose gradient sedimentation. In the absence of detergents, ribosomal precursor particles were found in a gradient fraction which sedimented faster than mature 50S subunits and in two other fractions coincident with mature 50S and 30S ribosomal subunits. Phospholipid, an indicator of membrane, was shown to be associated with only the fastest-sedimenting ribosomal precursor particle fraction. After the extracts were treated with detergents, all phospholipid was found at the top of the gradients. Brij 58, Triton X-100, and Nonidet P-40 did not cause a change in the sedimentation values of precursors; however, the detergents deoxycholate or LOC (Amway Corp.) disrupted the fastest-sedimenting precursor and converted the ribosomal precursor subunits which sedimented at the 50S and 30S positions to five different classes of more slowly sedimenting particles. Earlier reports on the in vivo assembly of ribosomal subunits have shown that several stages of ribosomal precursor subunits exist, and, in the presence of the detergents deoxycholate and LOC, which had been used to prepare cell extracts, the precursors sedimented more slowly. Our data are consistent with the hypothesis that those detergents selectively modify the structure of ribosomal precursors and lend further support to the hypothesis that the in vivo ribosomal precursor subunits have 50S and 30S sedimentation values. In addition, these data support the idea that the ribosomal precursor particles found in the fast-sedimenting fraction may constitute a unique precursor fraction.

  20. The effect of fibre source on the numbers of some fibre-degrading bacteria of Arabian camel's (Camelus dromedarius) foregut origin.

    PubMed

    Samsudin, Anjas Asmara; Wright, André-Denis; Al Jassim, Rafat

    2014-10-01

    The total bacterial community of Fibrobacter succinogenes and Ruminococcus flavefaciens in fibre-enriched culture of the foregut contents of 12 adult feral camels (Camelus dromedaries) fed on native vegetation in Australia was investigated using quantitative PCR. Foregut contents were collected postmortem, pooled and filtered before divided into two fractions. One fraction was used for extraction of DNA, while the other fraction was inoculated straight away into BM 10 contained filter paper (FP), cotton thread (CT) or neutral detergent fibre (NDF) as the sole carbohydrate sources in Hungate tubes. The tubes were incubated anaerobically at 39 °C for 1 week. After a near complete degradation of the FP and CT and extensive turbidity in the NDF, media subculturing was carried out into fresh media tubes. This was repeated twice before genomic DNA was extracted and used for quantification of bacteria. Using an absolute quantification method, the numbers of cells in 1 ml of each sample ranged from 4.07 × 10(6) to 2.73 × 10(9) for total bacteria, 1.34 × 10(3) to 2.17 × 10(5) for F. succinogenes and 5.78 × 10(1) to 3.53 × 10(4) for R. flavefaciens. The mean cell number of F. succinogenes was highest in the FP enrichment medium at approximately 107-fold, whereas for the R. flavefaciens targeted primer, the NDF enrichment media had the highest mean cell number at approximately 4-fold when compared to the rumen content. The data presented here provide evidence of fibre type preference by the two main fibre-degrading bacteria and would help us understand the interaction between fibre type and fibre-degrading microorganisms, which has ramification on camel nutrition at different seasons and environments.

  1. Physiological effects of fibre-rich types of bread. 1. The effect of dietary fibre from bread on the mineral balance of young men.

    PubMed

    Van Dokkum, W; Wesstra, A; Schippers, F A

    1982-05-01

    1. Twelve young adult male volunteers were given a low-fibre white bread diet (9 g neutral-detergent fibre (NDF)/d) and a medium-fibre coarse-bran bread diet (22 g NDF/d), each lasting 20 d. In ad third period of 20 d the volunteers were subdivided in groups of four, consuming a high-fibre coarse-bran bread diet (35 g NDF/d), a medium-fibre fine-bran bread diet (22 g NDF/d, bran particle size less than 0.35 mm) or a wholemeal bread diet (22 g NDF/d). Retention of calcium, magnesium, iron, zinc and copper were determined during each 20 d period. 2. An increase of the amount of dietary fibre (through bran) from 9 g to 22 g NDF/d resulted in a significantly increased mineral intake, but also faecal excretion increased significantly; mineral retention remained almost constant. 3. Both intake and faecal excretion of all minerals studied, except faecal Ca, increased further (P less than 0.05) on the diet providing 35 g NDF/d; only Fe balance decreased significantly. No significant differences with respect to intake, excretion (except urinary Ca) and balance of the minerals could be detected between the coarse-bran bread and fine-bran bread diets providing 22 g NDF/d. Faecal Fe, Cu balance and Mg balance increased significantly during the wholemeal bread period compared to the coarse-bran bread diet providing 22 g NDF. 4. Serum cholesterol increased significantly, i.e. by 0.3 mmol/l, during the coarse-bran bread diet providing 22 g NDF, compared to the white-bread diet. 5. It is concluded that increasing the amount of bran in bread does not appear to affect mineral balance considerably but there seems to be an influence on mineral availability. The increased intake was accompanied by increased faecal excretion.

  2. Asbestos fibres introduce trace metals into streamwater and sediments.

    PubMed

    Schreier, H

    1987-01-01

    Based on a case study in the Sumas River, it is demonstrated that asbestos fibres, which were introduced by a massive landslide, have altered the water quality and sediment conditions in the downstream section of the river. Asbestos fibres, because of their small size, are readily transported and resuspended i in stream systems. Associated with the fibres are high quantities of Ni, Cr, Co and Mn which occur as contaminations and isomorphic substitutions in most asbestos materials. A direct link between discharge, asbestos fibre and Ni concentrations was demonstrated in the water. Trace metal values in the sediments decrease with distance from the point source but the concentrations 20 km downstream of the slide are still significantly higher than levels at a control station unaffected by the slide. Asbestos fibres leach in acid media, and Mg and trace metals are removed. The process and rates were illustrated on the basis of laboratory experiments using organic acids. Since the pH in the streamwater is decreasing from 8.4 to 7.1 in the downstream direction, trace metals release is of concern. PMID:15092801

  3. Suitability of the isolated chicken eye test for classification of extreme pH detergents and cleaning products.

    PubMed

    Cazelle, Elodie; Eskes, Chantra; Hermann, Martina; Jones, Penny; McNamee, Pauline; Prinsen, Menk; Taylor, Hannah; Wijnands, Marcel V W

    2015-04-01

    A.I.S.E. investigated the suitability of the regulatory adopted ICE in vitro test method (OECD TG 438) with or without histopathology to identify detergent and cleaning formulations having extreme pH that require classification as EU CLP/UN GHS Category 1. To this aim, 18 extreme pH detergent and cleaning formulations were tested covering both alkaline and acidic extreme pHs. The ICE standard test method following OECD Test Guideline 438 showed good concordance with in vivo classification (83%) and good and balanced specificity and sensitivity values (83%) which are in line with the performances of currently adopted in vitro test guidelines, confirming its suitability to identify Category 1 extreme pH detergent and cleaning products. In contrast to previous findings obtained with non-extreme pH formulations, the use of histopathology did not improve the sensitivity of the assay whilst it strongly decreased its specificity for the extreme pH formulations. Furthermore, use of non-testing prediction rules for classification showed poor concordance values (33% for the extreme pH rule and 61% for the EU CLP additivity approach) with high rates of over-prediction (100% for the extreme pH rule and 50% for the additivity approach), indicating that these non-testing prediction rules are not suitable to predict Category 1 hazards of extreme pH detergent and cleaning formulations.

  4. Indirect fibre-optic colorimetric determination of ascorbic acid using 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and cloud point extraction.

    PubMed

    Filik, Hayati; Giray, Derya

    2013-04-01

    A new method has been developed for the indirect determination of ascorbic acid (AA) in commercial syrup preparations based on cloud point extraction (CPE) separation and preconcentration, and determination by molecular absorption spectrometry. The colorimetric method was based on the reduction of Fe(III) to Fe(II) and complexation of Fe(II) with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (Br-PADAP), followed by its extraction into Triton X-114. Selectivity of the method was increased with the use of EDTA as a masking agent. The absorbance was measured at 742 nm. Various influencing factors on the separation and preconcentration of AA have been investigated systematically, and the optimized operation conditions were established. The proposed method allows the determination of AA in the range 5-200 µg L(-1) with a relative standard deviation of 3.0%. The detection limit was found to be 0.9 µg L(-1) for AA. This method has been applied to the determination of ascorbic acid in commercial pharmaceutical preparations.

  5. Detergent-compatible proteases: microbial production, properties, and stain removal analysis.

    PubMed

    Niyonzima, Francois Niyongabo; More, Sunil

    2015-01-01

    Proteases are one of the most important commercial enzymes used in various industrial domains such as detergent and leather industries. The alkaline proteases as well as other detergent-compatible enzymes such as lipases and amylases serve now as the key components in detergent formulations. They break down various stains during fabric washing. The search for detergent-compatible proteases with better properties is a continuous exercise. The current trend is to use detergent-compatible proteases that are stable over a wide temperature range. Although the proteases showing stability at elevated pH have the capacity to be used in detergent formulations, their usage can be significant if they are also stable and compatible with detergent and detergent ingredients, and also able to remove protein stains. Despite the existence of some reviews on alkaline proteases, there is no specification for the use of alkaline proteases as detergent additives. The present review describes the detergent-compatible proteases tested as detergent additives. An overview was provided for screening, optimization, purification, and properties of detergent compatible proteases, with an emphasis on the stability and compatibility of the alkaline proteases with the detergent and detergent compounds, as well as stain removal examination methods.

  6. Periodic Structures in Optical Fibres.

    NASA Astrophysics Data System (ADS)

    Hand, Duncan Paul

    1990-01-01

    Available from UMI in association with The British Library. The work presented in this thesis concerns techniques for the formation of periodic structures in optical fibres. Two different methods of producing such structures are studied in detail. The first of these involves a breakdown mechanism (known as the 'fibre fuse') that permanently damages the core glass in a periodic manner leaving it unable to guide light. The dynamics of this mechanism are studied, with a view to controlling it for the production of interactive grating structures. It is determined that, due to a sharp rise in fibre absorption with temperature, a thermal shock -wave, with a typical thermal gradient of several hundred degrees Kelvin per micron, forms and travels along the fibre, heating the core glass to such an extent that damage occurs. The periodicity of the resultant damage arises from thermal focusing and defocusing of light in the region of this shock-wave. The second method makes use of the photorefractivity observed in certain germanosilicate fibres on exposure to moderate intensity blue light of wavelength ~480nm or UV light ~240nm. A single-mode fibre transmission filter is demonstrated for the first time, produced by exposing a fibre Sagnac loop mirror to 488nm holographic fringes. Average index changes are shown to occur if such fibres are exposed to spatially uniform blue or UV light, indicating that grating formation is by a different mechanism to the local charge separation which occurs in photorefractive crystals. The various characteristics of these average index changes are measured and analysed, with the conclusion that they result from defect centre formation, driven by two photon absorption with blue light, or single photon absorption with UV light. Associated birefringence changes are also measured and are exploited in a hi-bi fibre to periodically perturb the birefringence axes, producing a narrow-line transmission filter.

  7. Whispering-gallery waves in optical fibres

    SciTech Connect

    Sychugov, V A; Torchigin, V P; Tsvetkov, M Yu

    2002-08-31

    The process of excitation of whispering-gallery waves (WGWs) in optical fibres (microcavities) with the help of a bitapered fibre is analysed. It is shown that useful information on the WGW modes can be obtained from the spectrograms recorded by scanning the exciting-radiation frequency. Based on the geometrical-optic approximation, the longitudinal sizes of the WGW modes are estimated and it is shown that the ultimate diameter of the fibre exists for optical fibres (microcavities) where a mode can be still excited with the help of a bitapered fibre. (fibre optics. optical fibres)

  8. Isolation and Analysis of Detergent-Resistant Membrane Fractions.

    PubMed

    Aureli, Massimo; Grassi, Sara; Sonnino, Sandro; Prinetti, Alessandro

    2016-01-01

    The hypothesis that the Golgi apparatus is capable of sorting proteins and sending them to the plasma membrane through "lipid rafts," membrane lipid domains highly enriched in glycosphingolipids, sphingomyelin, ceramide, and cholesterol, was formulated by van Meer and Simons in 1988 and came to a turning point when it was suggested that lipid rafts could be isolated thanks to their resistance to solubilization by some detergents, namely Triton X-100. An incredible number of papers have described the composition and properties of detergent-resistant membrane fractions. However, the use of this method has also raised the fiercest criticisms. In this chapter, we would like to discuss the most relevant methodological aspects related to the preparation of detergent-resistant membrane fractions, and to discuss the importance of discriminating between what is present on a cell membrane and what we can prepare from cell membranes in a laboratory tube.

  9. Detergent activation of the binding protein in the folate radioassay

    SciTech Connect

    Hansen, S.I.; Holm, J.; Lyngbye, J.

    1982-01-01

    A minor cow's whey protein associated with ..beta..-lactoglobulin is used as binding protein in the competitive radioassay for serum and erythrocyte folate. Seeking to optimize the assay, we tested the performance of binder solutions of increasing purity. The folate binding protein was isolated from cow's whey by means of CM-Sepharose CL-6B cation-exchange chromatography, and further purified on a methotrexate-AH-Sepharose 4B affinity matrix. In contrast to ..beta..-lactoglobulin, the purified protein did not bind folate unless the detergents cetyltrimethylammonium (10 mmol/Ll) or Triton X-100 (1 g/L) were present. Such detergent activation was not needed in the presence of serum. There seems to be a striking analogy between these phenomena and the well-known reactivation of certain purified membrane-derived enzymes by surfactants (lipids/detergents).

  10. Detergent solubilization of the EGF receptor from A431 cells

    NASA Technical Reports Server (NTRS)

    Dayanidhi, R.; Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    Functional reconstitution of purified preparations of human epidermal growth factor receptor (EGFR) requires dissociation of the protein from its plasma membrane lipid environment. Solubilization of membrane proteins in this manner requires the use of detergents, which are known to disrupt plasma membrane lipid/protein interactions. We have investigated the ability of three nonionic detergents to solubilize the human EGFR selectively, and have also analyzed the effect of these various treatments on the intrinsic tyrosyl kinase activity of the receptor. The nonionic detergent known as n-octyl glucoside (n-octyl beta-D-glucopyranoside) was found to give the best combination of selectivity, yield, and maintenance of enzymatic activity of the human EGFR.

  11. [Control of the effects and side-effects of detergents].

    PubMed

    Schneider, W

    1977-08-01

    An examination of detergents on the skin has to take into account the facultative sensibilisation and the wear and tear. In this connection the effect of summation between soapbody and perfume is pointed out as well as the different results of skin tests. To control the obligate effects, first of all a reliable technical reference has to be established; this is the washing activity, to which the side-effects then are related. To measure the hydratation, the resonance-frequency method of Tronnier and Wagener is used, where especially the syndets react very differently: partly similar to water and partly similar to soft soap. Further methods of examination are the measurement of the roughness and the quantitative determination of the fat of the skin. Concerning certain hand wash detergents and industrial cleaners the grade of rubbing is also of interest. Finally the relatively good compatibility of the bioactive detergents and the rinsing agents is discussed.

  12. Late-onset respiratory distress after inhalation of laundry detergent.

    PubMed

    Wheeler, Derek S; Bonny, Andrea E; Ruddy, Richard M; Jacobs, Brian R

    2003-04-01

    Accidental poisoning with household cleaning products can pose significant risks to children. Exposure to granular laundry detergents accounts for a number of calls each year to poison control centers, though few of these exposures result in hospitalization. While caustic gastrointestinal injury resulting from ingestion of these highly alkaline cleaning agents is well-recognized, few reports address the potential damage to the respiratory tract that can occur following ingestion or inhalation of granular laundry detergent. We present a previously healthy 1-year-old who presented to the emergency department with Late-onset stridor and increased work of breathing following presumed inhalation of granular laundry detergent. Parents, primary care providers, and emergency department physicians need to be aware of the potential toxicity of these widely used household products.

  13. Optical fibre gas detections systems

    NASA Astrophysics Data System (ADS)

    Culshaw, Brian

    2016-05-01

    This tutorial review covers the principles of and prospects for fibre optic sensor technology in gas detection. Many of the potential benefits common to fibre sensor technology also apply in the context of gas sensing - notably long distance - many km - access to multiple remote measurement points; invariably intrinsic safety; access to numerous important gas species and often uniquely high levels of selectivity and/or sensitivity. Furthermore, the range of fibre sensor network architectures - single point, multiple point and distributed - enable unprecedented flexibility in system implementation. Additionally, competitive technologies and regulatory issues contribute to final application potential.

  14. Differential sensitivity to detergents of actin cytoskeleton from nerve endings.

    PubMed

    Cubí, Roger; Matas, Lluís A; Pou, Marta; Aguilera, José; Gil, Carles

    2013-11-01

    Detergent-resistant membranes (DRM), an experimental model used to study lipid rafts, are typically extracted from cells by means of detergent treatment and subsequent ultracentrifugation in density gradients, Triton X-100 being the detergent of choice in most of the works. Since lipid rafts are membrane microdomains rich in cholesterol, depletion of this component causes solubilization of DRM with detergent. In previous works from our group, the lack of effect of cholesterol depletion on DRM solubilization with Triton X-100 was detected in isolated rat brain synaptosomes. In consequence, the aim of the present work is to explore reasons for this observation, analyzing the possible role of the actin cytoskeleton, as well as the use of an alternative detergent, Brij 98, to overcome the insensitivity to Triton X-100 of cholesterol-depleted DRM. Brij 98 yields Brij-DRM that are highly dependent on cholesterol, since marker proteins (Flotillin-1 and Thy-1), as well as actin, appear solubilized after MCD treatment. Pretreatment with Latrunculin A results in a significant increase in Flotillin-1, Thy-1 and actin solubilization by Triton X-100 after cholesterol depletion. Studies with transmission electron microscopy show that combined treatment with MCD and Latrunculin A leads to a significant increase in solubilization of DRM with Triton X-100. Thus, Triton-DRM resistance to cholesterol depletion can be explained, at least partially, thanks to the scaffolding action of the actin cytoskeleton, without discarding differential effects of Brij 98 and Triton X-100 on specific membrane components. In conclusion, the detergent of choice is important when events that depend on the actin cytoskeleton are going to be studied.

  15. A TACC3/ch-TOG/clathrin complex stabilises kinetochore fibres by inter-microtubule bridging

    PubMed Central

    Booth, Daniel G; Hood, Fiona E; Prior, Ian A; Royle, Stephen J

    2011-01-01

    Kinetochore fibres (K-fibres) of the spindle apparatus move chromosomes during mitosis. These fibres are discrete bundles of parallel microtubules (MTs) that are crosslinked by inter-MT ‘bridges' that are thought to improve fibre stability during chromosomal movement. The identity of these bridges is unknown. Clathrin is a multimeric protein that has been shown to stabilise K-fibres during early mitosis by a mechanism independent of its role in membrane trafficking. In this study, we show that clathrin at the mitotic spindle is in a transforming acidic colied-coil protein 3 (TACC3)/colonic, hepatic tumour overexpressed gene (ch-TOG)/clathrin complex. The complex is anchored to the spindle by TACC3 and ch-TOG. Ultrastructural analysis of clathrin-depleted K-fibres revealed a selective loss of a population of short inter-MT bridges and a general loss of MTs. A similar loss of short inter-MT bridges was observed in TACC3-depleted K-fibres. Finally, immunogold labelling confirmed that inter-MT bridges in K-fibres contain clathrin. Our results suggest that the TACC3/ch-TOG/clathrin complex is an inter-MT bridge that stabilises K-fibres by physical crosslinking and by reducing rates of MT catastrophe. PMID:21297582

  16. Polarisation reflectometry of anisotropic optical fibres

    SciTech Connect

    Konstantinov, Yurii A; Kryukov, Igor' I; Pervadchuk, Vladimir P; Toroshin, Andrei Yu

    2009-11-30

    Anisotropic, polarisation-maintaining fibres have been studied using a reflectometer and integrated optic polariser. Linearly polarised pulses were launched into the fibre under test at different angles between their plane of polarisation and the main optical axis of the fibre. A special procedure for the correlation analysis of these reflectograms is developed to enhance the reliability of the information about the longitudinal optical uniformity of anisotropic fibres. (optical fibres and fibreoptic sensors)

  17. Action on ileal smooth muscle of synthetic detergents and pardaxin.

    PubMed

    Primor, N

    1986-01-01

    Pardaxin (PX), a toxic and repellent substance isolated from the Red Sea flatfish, causes a sharp ball-like profile of drop of saline placed on a hydrophobic film to turn into a flattened one. This effect results with a decrease of the contact angle (theta) from 96 degrees to a maximum of 42 degrees at 10(-4) M of PX. The action of sodium dodecyl sulphate (SDS), a synthetic anionic detergent, benzalkonium chloride (BAC) cationic detergent and pardaxin (PX) a toxic protein with detergent properties, were studied in the ileal guinea-pig longitudinal smooth muscle preparation. SDS (4 X 10(-4) M) and PX (5 X 10(-6) M) diminished the muscle contractile response to field stimulation (0.1 Hz, 1 msec) and to acetylcholine (Ach) and to histamine and elicited a prolonged (4-6 min) TTX-insensitive muscle contraction. The dose dependence of muscle contraction to SDS and PX was found to be sigmoidal and occurred over a narrow range of concentrations. The SDS- but not PX-induced muscle contraction could be reduced by diphenhydramine (H1 antihistamine). BAC (10(-5)-10(-4) M) suppressed the muscle's contractile response to electrical stimulation (0.1 Hz, 1 msec), to Ach, histamine and 5-hydroxytryptamine but did not produce muscle contraction. PX at concentrations higher than 5 X 10(-6) M is a potent detergent and at this concentration shares several pharmacological similarities with SDS.

  18. Detergent-assisted oxidative folding of delta-conotoxins.

    PubMed

    DeLa Cruz, R; Whitby, F G; Buczek, O; Bulaj, G

    2003-04-01

    Conotoxins comprise a diverse group of disulfide-rich peptides found in venoms of predatory Conus species. The native conformation of these peptides is marginally stable in comparison with alternative conformations, often resulting in low folding yields. The oxidative folding of hydrophobic delta-conotoxins was found to produce less than 1% of the native peptide [Bulaj, G. et al. (2001) Biochemistry 40, 13201]. In order to identify factors that might improve folding yields, we screened a number of additives including water-soluble polymers, detergents and osmolytes for their ability to increase steady-state accumulation of the native delta-conotoxin PVIA. The presence of a non-ionic detergent Tween and low temperature appeared to be the most effective factors in improving the oxidative folding. The detergent was also effective in promoting folding of other hydrophobic delta-conotoxins. Based on our findings, we discuss a possible mechanism for detergent-assisted folding and the general applicability of this mechanism to facilitating the proper folding of hydrophobic, cysteine-rich peptides.

  19. 40 CFR 80.161 - Detergent additive certification program.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... additive manufacturer must properly register the detergent additive under 40 CFR part 79. For this purpose... claims according to the regulations at 40 CFR part 2. (v) The sample shall be submitted to EPA, at the... shall be informal, and the hearing shall not be subject to or governed by 40 CFR part 22 or by 5...

  20. 40 CFR 80.161 - Detergent additive certification program.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... additive manufacturer must properly register the detergent additive under 40 CFR part 79. For this purpose... documents with such claims according to the regulations at 40 CFR part 2. (v) The sample shall be submitted... shall be informal, and the hearing shall not be subject to or governed by 40 CFR part 22 or by 5...

  1. 40 CFR 80.161 - Detergent additive certification program.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... additive manufacturer must properly register the detergent additive under 40 CFR part 79. For this purpose... claims according to the regulations at 40 CFR part 2. (v) The sample shall be submitted to EPA, at the... shall be informal, and the hearing shall not be subject to or governed by 40 CFR part 22 or by 5...

  2. Arsenic in detergents: Possible danger and pollution hazard

    USGS Publications Warehouse

    Angino, E.E.; Magnuson, L.M.; Waugh, T.C.; Galle, O.K.; Bredfeldt, J.

    1970-01-01

    Arsenic at a concentration of 10 to 70 parts per million has been detected in several common presoaks and household detergents. Arsenic values of 2 to 8 parts per billion have been measured in the Kansas River. These concentrations are close to the amount (10 parts per billion) recommended by the United States Public Health Service as a drinking-water standard.

  3. 40 CFR 80.161 - Detergent additive certification program.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... additive manufacturer must properly register the detergent additive under 40 CFR part 79. For this purpose... claims according to the regulations at 40 CFR part 2. (v) The sample shall be submitted to EPA, at the... shall be informal, and the hearing shall not be subject to or governed by 40 CFR part 22 or by 5...

  4. Membrane Protein Solubilization and Composition of Protein Detergent Complexes.

    PubMed

    Duquesne, Katia; Prima, Valérie; Sturgis, James N

    2016-01-01

    Membrane proteins are typically expressed in heterologous systems with a view to in vitro characterization. A critical step in the preparation of membrane proteins after expression in any system is the solubilization of the protein in aqueous solution, typically using detergents and lipids, to obtain the protein in a form suitable for purification, structural or functional analysis. This process is particularly difficult as the objective is to prepare the protein in an unnatural environment, a protein detergent complex, separating it from its natural lipid partners while causing the minimum destabilization or modification of the structure. Although the process is difficult, and relatively hard to master, an increasing number of membrane proteins have been successfully isolated after expression in a wide variety of systems. In this chapter we give a general protocol for preparing protein detergent complexes that is aimed at guiding the reader through the different critical steps. In the second part of the chapter we illustrate how to analyze the composition of protein detergent complexes; this analysis is important as it has been found that compositional variation often causes irreproducible results. PMID:27485340

  5. 40 CFR 80.141 - Interim detergent gasoline program.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... mixtures of gasoline and alcohol fuels, gasoline used as marine fuel, gasoline service accumulation fuel... registered by its manufacturer under 40 CFR part 79 according to the specifications in paragraphs (c) (1... Deposits—Fuel Detergency Requirements Revisited”, Bill Bitting et al., Society of Automotive Engineers,...

  6. 40 CFR 80.141 - Interim detergent gasoline program.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... mixtures of gasoline and alcohol fuels, gasoline used as marine fuel, gasoline service accumulation fuel... registered by its manufacturer under 40 CFR part 79 according to the specifications in paragraphs (c) (1... Deposits—Fuel Detergency Requirements Revisited”, Bill Bitting et al., Society of Automotive Engineers,...

  7. 40 CFR 80.141 - Interim detergent gasoline program.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... mixtures of gasoline and alcohol fuels, gasoline used as marine fuel, gasoline service accumulation fuel... registered by its manufacturer under 40 CFR part 79 according to the specifications in paragraphs (c) (1... Deposits—Fuel Detergency Requirements Revisited”, Bill Bitting et al., Society of Automotive Engineers,...

  8. 40 CFR 80.141 - Interim detergent gasoline program.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... mixtures of gasoline and alcohol fuels, gasoline used as marine fuel, gasoline service accumulation fuel... registered by its manufacturer under 40 CFR part 79 according to the specifications in paragraphs (c) (1... Deposits—Fuel Detergency Requirements Revisited”, Bill Bitting et al., Society of Automotive Engineers,...

  9. 40 CFR 80.141 - Interim detergent gasoline program.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... mixtures of gasoline and alcohol fuels, gasoline used as marine fuel, gasoline service accumulation fuel... registered by its manufacturer under 40 CFR part 79 according to the specifications in paragraphs (c) (1... Deposits—Fuel Detergency Requirements Revisited”, Bill Bitting et al., Society of Automotive Engineers,...

  10. 40 CFR 80.161 - Detergent additive certification program.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... additive manufacturer must properly register the detergent additive under 40 CFR part 79. For this purpose... available information on optimal temperature, light exposure, or other conditions to prolong sample shelf... claims according to the regulations at 40 CFR part 2. (v) The sample shall be submitted to EPA, at...

  11. A Lab Experience to Illustrate the Physicochemical Principles of Detergency

    ERIC Educational Resources Information Center

    Poce-Fatou, J. A.; Bethencourt-Nunez, M.; Moreno, C.; Pinto-Ganfornina, J. J.; Moreno-Dorado, F. J.

    2008-01-01

    This article presents a lab experience to study detergency from a physicochemical point of view intended for undergraduate students. By means of a simple experimental device, we analyze the influence of the surfactant concentration in both distilled water and tap water. Our method is based on the measurement of diffuse reflectances of polyester…

  12. 3 in 4 Youngsters Exposed to Laundry Pod Detergent Suffer Poisoning

    MedlinePlus

    ... 160006.html 3 in 4 Youngsters Exposed to Laundry Pod Detergent Suffer Poisoning Hospitalizations 4 times more common with ... THURSDAY, July 21, 2016 (HealthDay News) -- Brightly colored laundry detergent pods pose a much greater risk to young ...

  13. Physiological effects of fibre-rich types of bread. 2. Dietary fibre from bread: digestibility by the intestinal microflora and water-holding capacity in the colon of human subjects.

    PubMed

    Van Dokkum, W; Pikaar, N A; Thissen, J T

    1983-07-01

    Twelve young adult male volunteers were given a low-fibre white bread diet (9 g neutral-detergent fibre (NDF)/d) and a medium-fibre coarse-bran bread diet (22 g NDF/d), each lasting 20 d. In a third period of 20 d the volunteers were subdivided in groups of four, consuming a high-fibre coarse-bran bread diet (35 g NDF/d), a medium-fibre fine-bran diet (22 g NDF/d, bran particle size greater than 0.35 mm) or a wholemeal bread diet (22 g NDF/d). Digestion of dietary fibre and its components hemicellulose, cellulose and lignin were determined as well as colonic function. An increase of the amount of dietary fibre (through bran in bread) from 9 to 22 g NDF/d resulted in the following significant changes (P less than 0.01): increase in faecal wet weight of 63 g/d, decrease in the percentage of faecal dry weight from 27 to 24, increase in defaecation frequency of 0.2 stools/d and reduction of the intestinal transit time of 36 h. Further significant changes with regard to all factors mentioned were observed during the high-fibre diet. Faecal wet weight was significantly (P less than 0.05) lower with the fine-bran bread diet than with the coarse-bran bread on a similar fibre intake of 22 g NDF/d. Results obtained in the wholemeal-bread period did not show significant differences compared with those from the coarse-bran bread period of 22 g NDF/d. Mean digestibilities for the fibre from bread were: for NDF 0.34, for hemicellulose 0.46, for cellulose 0.20 and for lignin 0.04. The results obtained suggest that the theory of sponge activity of the fibre matrix structure is the predominant factor accounting for the water binding capacity of fibre in the colon.

  14. 40 CFR 417.170 - Applicability; description of the manufacture of detergents by dry blending subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... manufacture of detergents by dry blending subcategory. 417.170 Section 417.170 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.170...

  15. 40 CFR 80.155 - Interim detergent program controls and prohibitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... detergent registered under 40 CFR part 79, and in accordance with at least the minimum concentration specifications of that detergent as registered under 40 CFR part 79 or as otherwise provided under § 80.141(d... detergent registered under 40 CFR part 79, and in accordance with at least the minimum...

  16. 76 FR 9013 - Agency Information Collection Activities; Proposed Collection; Comment Request; Detergent Gasoline

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-16

    ... AGENCY Agency Information Collection Activities; Proposed Collection; Comment Request; Detergent Gasoline... this action are those who (1) Manufacture gasoline, post-refinery component, or detergent additives, (2) blend detergent additives into gasoline or post-refinery component, or (3) transport or receive...

  17. 40 CFR 80.169 - Liability for violations of the detergent certification program controls and prohibitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... detergent certification program controls and prohibitions. 80.169 Section 80.169 Protection of Environment... Detergent Gasoline § 80.169 Liability for violations of the detergent certification program controls and..., carrier, distributor, reseller, retailer, wholesale purchaser-consumer, oxygenate blender, or...

  18. 40 CFR 80.169 - Liability for violations of the detergent certification program controls and prohibitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... detergent certification program controls and prohibitions. 80.169 Section 80.169 Protection of Environment... Detergent Gasoline § 80.169 Liability for violations of the detergent certification program controls and..., carrier, distributor, reseller, retailer, wholesale purchaser-consumer, oxygenate blender, or...

  19. 40 CFR 417.180 - Applicability; description of the manufacture of drum dried detergents subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... manufacture of drum dried detergents subcategory. 417.180 Section 417.180 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.180...

  20. 40 CFR 417.160 - Applicability; description of the manufacture of liquid detergents subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... manufacture of liquid detergents subcategory. 417.160 Section 417.160 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Detergents Subcategory § 417.160 Applicability; description of...

  1. 40 CFR 80.168 - Detergent certification program controls and prohibitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Detergent certification program... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.168 Detergent certification program controls and prohibitions. (a)(1) No person shall sell, offer for...

  2. 40 CFR 80.155 - Interim detergent program controls and prohibitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... detergent registered under 40 CFR part 79, and in accordance with at least the minimum concentration specifications of that detergent as registered under 40 CFR part 79 or as otherwise provided under § 80.141(d... detergent registered under 40 CFR part 79, and in accordance with at least the minimum...

  3. 40 CFR 80.169 - Liability for violations of the detergent certification program controls and prohibitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... detergent certification program controls and prohibitions. 80.169 Section 80.169 Protection of Environment... Detergent Gasoline § 80.169 Liability for violations of the detergent certification program controls and..., carrier, distributor, reseller, retailer, wholesale purchaser-consumer, oxygenate blender, or...

  4. 40 CFR 417.160 - Applicability; description of the manufacture of liquid detergents subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... manufacture of liquid detergents subcategory. 417.160 Section 417.160 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Detergents Subcategory § 417.160 Applicability; description of...

  5. 40 CFR 80.155 - Interim detergent program controls and prohibitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... detergent registered under 40 CFR part 79, and in accordance with at least the minimum concentration specifications of that detergent as registered under 40 CFR part 79 or as otherwise provided under § 80.141(d... detergent registered under 40 CFR part 79, and in accordance with at least the minimum...

  6. 40 CFR 417.150 - Applicability; description of the manufacture of spray dried detergents subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... manufacture of spray dried detergents subcategory. 417.150 Section 417.150 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Spray Dried Detergents Subcategory § 417.150...

  7. 40 CFR 417.160 - Applicability; description of the manufacture of liquid detergents subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... manufacture of liquid detergents subcategory. 417.160 Section 417.160 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Detergents Subcategory § 417.160 Applicability; description of...

  8. 40 CFR 417.170 - Applicability; description of the manufacture of detergents by dry blending subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... manufacture of detergents by dry blending subcategory. 417.170 Section 417.170 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.170...

  9. 40 CFR 417.160 - Applicability; description of the manufacture of liquid detergents subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... manufacture of liquid detergents subcategory. 417.160 Section 417.160 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Detergents Subcategory § 417.160 Applicability; description of...

  10. 40 CFR 80.168 - Detergent certification program controls and prohibitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Detergent certification program... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.168 Detergent certification program controls and prohibitions. (a)(1) No person shall sell, offer for...

  11. 40 CFR 417.150 - Applicability; description of the manufacture of spray dried detergents subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... manufacture of spray dried detergents subcategory. 417.150 Section 417.150 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Spray Dried Detergents Subcategory § 417.150...

  12. 40 CFR 417.180 - Applicability; description of the manufacture of drum dried detergents subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... manufacture of drum dried detergents subcategory. 417.180 Section 417.180 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.180...

  13. 40 CFR 417.170 - Applicability; description of the manufacture of detergents by dry blending subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... manufacture of detergents by dry blending subcategory. 417.170 Section 417.170 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.170...

  14. 40 CFR 80.155 - Interim detergent program controls and prohibitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... detergent registered under 40 CFR part 79, and in accordance with at least the minimum concentration specifications of that detergent as registered under 40 CFR part 79 or as otherwise provided under § 80.141(d... detergent registered under 40 CFR part 79, and in accordance with at least the minimum...

  15. 40 CFR 417.180 - Applicability; description of the manufacture of drum dried detergents subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... manufacture of drum dried detergents subcategory. 417.180 Section 417.180 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.180...

  16. 40 CFR 417.180 - Applicability; description of the manufacture of drum dried detergents subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... manufacture of drum dried detergents subcategory. 417.180 Section 417.180 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.180...

  17. 40 CFR 417.150 - Applicability; description of the manufacture of spray dried detergents subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... manufacture of spray dried detergents subcategory. 417.150 Section 417.150 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Spray Dried Detergents Subcategory § 417.150...

  18. 40 CFR 417.180 - Applicability; description of the manufacture of drum dried detergents subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... manufacture of drum dried detergents subcategory. 417.180 Section 417.180 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.180...

  19. 40 CFR 80.168 - Detergent certification program controls and prohibitions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Detergent certification program... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.168 Detergent certification program controls and prohibitions. (a)(1) No person shall sell, offer for...

  20. 40 CFR 417.170 - Applicability; description of the manufacture of detergents by dry blending subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... manufacture of detergents by dry blending subcategory. 417.170 Section 417.170 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.170...

  1. 40 CFR 417.160 - Applicability; description of the manufacture of liquid detergents subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... manufacture of liquid detergents subcategory. 417.160 Section 417.160 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Liquid Detergents Subcategory § 417.160 Applicability; description of...

  2. 40 CFR 80.168 - Detergent certification program controls and prohibitions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Detergent certification program... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.168 Detergent certification program controls and prohibitions. (a)(1) No person shall sell, offer for...

  3. 40 CFR 80.168 - Detergent certification program controls and prohibitions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Detergent certification program... (CONTINUED) AIR PROGRAMS (CONTINUED) REGULATION OF FUELS AND FUEL ADDITIVES Detergent Gasoline § 80.168 Detergent certification program controls and prohibitions. (a)(1) No person shall sell, offer for...

  4. 40 CFR 417.170 - Applicability; description of the manufacture of detergents by dry blending subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... manufacture of detergents by dry blending subcategory. 417.170 Section 417.170 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Detergents by Dry Blending Subcategory § 417.170...

  5. 40 CFR 417.190 - Applicability; description of the manufacture of detergent bars and cakes subcategory.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... manufacture of detergent bars and cakes subcategory. 417.190 Section 417.190 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Detergent Bars and Cakes Subcategory § 417.190 Applicability; description of the manufacture of detergent bars and cakes subcategory. The provisions of this subpart...

  6. 40 CFR 417.190 - Applicability; description of the manufacture of detergent bars and cakes subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... manufacture of detergent bars and cakes subcategory. 417.190 Section 417.190 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Detergent Bars and Cakes Subcategory § 417.190 Applicability; description of the manufacture of detergent bars and cakes subcategory. The provisions of this subpart...

  7. 40 CFR 417.190 - Applicability; description of the manufacture of detergent bars and cakes subcategory.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... manufacture of detergent bars and cakes subcategory. 417.190 Section 417.190 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Detergent Bars and Cakes Subcategory § 417.190 Applicability; description of the manufacture of detergent bars and cakes subcategory. The provisions of this subpart...

  8. 40 CFR 417.190 - Applicability; description of the manufacture of detergent bars and cakes subcategory.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... manufacture of detergent bars and cakes subcategory. 417.190 Section 417.190 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Detergent Bars and Cakes Subcategory § 417.190 Applicability; description of the manufacture of detergent bars and cakes subcategory. The provisions of this subpart...

  9. 40 CFR 417.190 - Applicability; description of the manufacture of detergent bars and cakes subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... manufacture of detergent bars and cakes subcategory. 417.190 Section 417.190 Protection of Environment... POINT SOURCE CATEGORY Manufacture of Detergent Bars and Cakes Subcategory § 417.190 Applicability; description of the manufacture of detergent bars and cakes subcategory. The provisions of this subpart...

  10. Determination of the aggregate size in detergent solution of the light-harvesting chlorophyll a/b-protein complex from chloroplast membranes

    PubMed Central

    Butler, P. J. G.; Kühlbrandt, W.

    1988-01-01

    The molecular mass of an oligomeric integral membrane protein, the light-harvesting chlorophyll a/b-protein complex from the photosynthetic membranes of chloroplasts, has been determined in detergent solution by analytical ultracentrifugation and measurement of the density increment at constant chemical potential of all diffusible solutes. The technique used eliminates any problems resulting from detergent binding to the protein, is independent of the particular detergent used (in this case the nonionic n-octyl β-D-glucopyranoside), and gives the apparent weight-average molecular mass at different protein concentrations, allowing extrapolation to zero concentration. It means that the solutions of the complex must be brought to dialysis equilibrium with the solvent detergent solution and also requires a reliable method for measuring the protein concentration, for which amino acid analysis was used. The detergent-solubilized complex was a trimer that dissociated into monomers and dimers at low protein concentration. The accurate concentration determinations also allowed the molar chlorophyll-to-protein ratio to be measured as 15, corresponding to 8 chlorophyll a and 7 chlorophyll b molecules. PMID:16593931

  11. Amino phenol-detergent/dispersant combinations and fuels and lubricants containing same

    SciTech Connect

    Clason, D.L.; Cohen, J.M.; Pindar, J.F.

    1980-04-29

    Disclosed are combinations of amino phenols, wherein said phenols contain a substantially saturated hydrocarbon substituent of at least 10 aliphatic carbon atoms, and one or more detergent/dispersants selected from the group consisting of (I) neutral or basic metal salts of an organic sulfur acid, phenol or carboxylic acid; (II) hydrocarbyl-substituted amines wherein the hydrocarbyl substituent is substantially aliphatic and contains at least 12 carbon atoms; (III) acylated nitrogen-containing compounds having a substituent of at least 10 aliphatic carbon atoms; and (IV) nitrogen-containing condensates of a phenol, aldehyde and amino compound. Fuels and lubricants containing such combinations as additives are particularly useful in two-cycle (two-stroke) engines.

  12. Surface chemical changes of atmospheric pressure plasma treated rabbit fibres important for felting process

    NASA Astrophysics Data System (ADS)

    Štěpánová, Vlasta; Slavíček, Pavel; Stupavská, Monika; Jurmanová, Jana; Černák, Mirko

    2015-11-01

    We introduce the atmospheric pressure plasma treatment as a suitable procedure for in-line industrial application of rabbit fibres pre-treatment. Changes of rabbit fibre properties due to the plasma treatment were studied in order to develop new technology of plasma-based treatment before felting. Diffuse Coplanar Surface Barrier Discharge (DCSBD) in ambient air at atmospheric pressure was used for plasma treatment. Scanning electron microscopy was used for determination of the fibres morphology before and after plasma treatment. X-ray photoelectron spectroscopy and attenuated total reflectance-Fourier transform infrared spectroscopy were used for evaluation of reactive groups. The concentration of carbon decreased and conversely the concentration of nitrogen and oxygen increased after plasma treatment. Aging effect of plasma treated fibres was also investigated. Using Washburn method the significant increase of fibres wettability was observed after plasma treatment. New approach of pre-treatment of fibres before felting using plasma was developed. Plasma treatment of fibres at atmospheric pressure can replace the chemical method which consists of application of strong acids on fibres.

  13. Muscle fatigue resistance in the rat hindlimb in vivo from low dietary intakes of tuna fish oil that selectively increase phospholipid n-3 docosahexaenoic acid according to muscle fibre type.

    PubMed

    Henry, R; Peoples, G E; McLennan, P L

    2015-09-28

    Dietary fish oil (FO) modulates muscle O2 consumption and contractile function, predictive of effects on muscle fatigue. High doses unattainable through human diet and muscle stimulation parameters used engender uncertainty in their physiological relevance. We tested the hypothesis that nutritionally relevant FO doses can modulate membrane fatty acid composition and muscle fatigue. Male Sprague-Dawley rats were randomised to control (10% olive oil (OO) by weight) or low or moderate FO diet (LowFO and ModFO) (HiDHA tuna fish oil) for 15 weeks (LowFO: 0.3% FO, 9.7% OO, 0.25% energy as EPA+DHA; ModFO: 1.25% FO, 8.75% OO, 1.0% energy as EPA+DHA). Hindlimb muscle function was assessed under anaesthesia in vivo using repetitive 5 s burst sciatic nerve stimulation (0.05 ms, 7-12 V, 5 Hz, 10 s duty cycle, 300 s). There were no dietary differences in maximum developed muscle force. Repetitive peak developed force fell to 50% within 62 (SEM 10) s in controls and took longer to decline in FO-fed rats (LowFO 110 (SEM 15) s; ModFO 117 (sem 14) s) (P<0.05). Force within bursts was better sustained with FO and maximum rates of force development and relaxation declined more slowly. The FO-fed rats incorporated higher muscle phospholipid DHA-relative percentages than controls (P<0.001). Incorporation of DHA was greater in the fast-twitch gastrocnemius (Control 9.3 (SEM 0.8) %, LowFO 19.9 (SEM 0.4), ModFO 24.3 (SEM 1.0)) than in the slow-twitch soleus muscle (Control 5.1 (SEM 0.2), LowFO 14.3 (SEM 0.7), ModFO 18.0 (SEM 1.4)) (P<0.001), which was comparable with the myocardium, in line with muscle fibre characteristics. The LowFO and ModFO diets, emulating human dietary and therapeutic supplement intake, respectively, both elicited muscle membrane DHA enrichment and fatigue resistance, providing a foundation for translating these physiological effects to humans. PMID:26266774

  14. Muscle fatigue resistance in the rat hindlimb in vivo from low dietary intakes of tuna fish oil that selectively increase phospholipid n-3 docosahexaenoic acid according to muscle fibre type.

    PubMed

    Henry, R; Peoples, G E; McLennan, P L

    2015-09-28

    Dietary fish oil (FO) modulates muscle O2 consumption and contractile function, predictive of effects on muscle fatigue. High doses unattainable through human diet and muscle stimulation parameters used engender uncertainty in their physiological relevance. We tested the hypothesis that nutritionally relevant FO doses can modulate membrane fatty acid composition and muscle fatigue. Male Sprague-Dawley rats were randomised to control (10% olive oil (OO) by weight) or low or moderate FO diet (LowFO and ModFO) (HiDHA tuna fish oil) for 15 weeks (LowFO: 0.3% FO, 9.7% OO, 0.25% energy as EPA+DHA; ModFO: 1.25% FO, 8.75% OO, 1.0% energy as EPA+DHA). Hindlimb muscle function was assessed under anaesthesia in vivo using repetitive 5 s burst sciatic nerve stimulation (0.05 ms, 7-12 V, 5 Hz, 10 s duty cycle, 300 s). There were no dietary differences in maximum developed muscle force. Repetitive peak developed force fell to 50% within 62 (SEM 10) s in controls and took longer to decline in FO-fed rats (LowFO 110 (SEM 15) s; ModFO 117 (sem 14) s) (P<0.05). Force within bursts was better sustained with FO and maximum rates of force development and relaxation declined more slowly. The FO-fed rats incorporated higher muscle phospholipid DHA-relative percentages than controls (P<0.001). Incorporation of DHA was greater in the fast-twitch gastrocnemius (Control 9.3 (SEM 0.8) %, LowFO 19.9 (SEM 0.4), ModFO 24.3 (SEM 1.0)) than in the slow-twitch soleus muscle (Control 5.1 (SEM 0.2), LowFO 14.3 (SEM 0.7), ModFO 18.0 (SEM 1.4)) (P<0.001), which was comparable with the myocardium, in line with muscle fibre characteristics. The LowFO and ModFO diets, emulating human dietary and therapeutic supplement intake, respectively, both elicited muscle membrane DHA enrichment and fatigue resistance, providing a foundation for translating these physiological effects to humans.

  15. Crystallization of the C-terminal head domain of the avian adenovirus CELO long fibre

    SciTech Connect

    Guardado Calvo, Pablo; Llamas-Saiz, Antonio L.; Langlois, Patrick; Raaij, Mark J. van

    2006-05-01

    Avian adenovirus long-fibre head trimers were expressed, purified and crystallized. The crystals belong to space group C2 (unit-cell parameters a = 216.5, b = 59.2, c = 57.5 Å, β = 101.3°). A complete highly redundant data set was collected to 2.2 Å resolution at 100 K using a rotating-anode X-ray source. Avian adenovirus CELO contains two different fibres: fibre 1, the long fibre, and fibre 2, the short fibre. The short fibre is responsible for binding to an unknown avian receptor and is essential for infection of birds. The long fibre is not essential, but is known to bind the coxsackievirus and adenovirus receptor protein. Both trimeric fibres are attached to the same penton base, of which each icosahedral virus contains 12 copies. The short fibre extends straight outwards, while the long fibre emerges at an angle. The carboxy-terminal amino acids 579–793 of the avian adenovirus long fibre have been expressed with an amino-terminal hexahistidine tag and the expressed trimeric protein has been purified by nickel-affinity chromatography and crystallized. Crystals were grown at low pH using PEG 10 000 as precipitant and belonged to space group C2. The crystals diffracted rotating-anode Cu Kα radiation to at least 1.9 Å resolution and a complete data set was collected from a single crystal to 2.2 Å resolution. Unit-cell parameters were a = 216.5, b = 59.2, c = 57.5 Å, β = 101.3°, suggesting one trimer per asymmetric unit and a solvent content of 46%. The long fibre head does not have significant sequence homology to any other protein of known structure and molecular-replacement attempts with known fibre-head structures were unsuccessful. However, a map calculated using SIRAS phasing shows a clear trimer with a shape similar to known adenovirus fibre-head structures. Structure solution is in progress.

  16. Polyol and Amino Acid-Based Biosurfactants, Builders, and Hydrogels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This chapter reviews different detergent materials which have been synthesized from natural agricultural commodities. Background information, which gives reasons why the use of biobased materials may be advantageous, is presented. Detergent builders from L-aspartic acid, citric acid and D-sorbitol...

  17. Coupling detergent lysis/clean-up methodology with intact protein fractionation for enhanced proteome characterization

    SciTech Connect

    Sharma, Ritin; Dill, Brian; Chourey, Karuna; Shah, Manesh B; Verberkmoes, Nathan C; Hettich, Robert {Bob} L

    2012-01-01

    The expanding use of surfactants for proteome sample preparations has prompted the need to systematically optimize the application and removal of these MS-deleterious agents prior to proteome measurements. Here we compare four different detergent clean-up methods (Trichloroacetic acid (TCA) precipitation, Chloroform/Methanol/Water (CMW) extraction, commercial detergent removal spin column method (DRS) and filter-aided sample preparation(FASP)) with respect to varying amounts of protein biomass in the samples, and provide efficiency benchmarks with respect to protein, peptide, and spectral identifications for each method. Our results show that for protein limited samples, FASP outperforms the other three clean-up methods, while at high protein amount all the methods are comparable. This information was used in a dual strategy of comparing molecular weight based fractionated and unfractionated lysates from three increasingly complex samples (Escherichia coli, a five microbial isolate mixture, and a natural microbial community groundwater sample), which were all lysed with SDS and cleaned up using FASP. The two approaches complemented each other by enhancing the number of protein identifications by 8%-25% across the three samples and provided broad pathway coverage.

  18. The rationale for a ban on detergent phosphate in the Great Lakes Basin.

    PubMed

    Alexander, G R

    Immediate reduction of phosphorus loadings to the Great Lakes is essential to slow accelerated eutrophication. The Great Lakes National Program Office of the US Environmental Protection Agency now advocates adoption of bans on detergent phosphates as the most practical and feasible means of immediately reducing the phosphorus loadings to the Great Lakes. This change in policy from previous reliance on removal by sewage treatment has been adopted for the following reasons: (1) Bans on phosphates will reduce capital and operating costs of treatment and, were adopted, have met with consumer acceptance. (2) In practice, treatment plants have not met design expectations for phosphate removal. (3) Neither nitrilotriacetic acid nor other substitutes for phosphates have proved to be a public health problem. (4) Reduction of phosphorus loadings to treatment plants avoids increasing levels of chlorides and total dissolved solids in effluents. (5) Water quality has improved in small lakes with phosphorus reduction. In summary, detergent phosphate bans alone will not reduce phosphorus loadings to the Great Lakes sufficiently for the long term but the Environmental Protection Agency has concluded that such action is necessary in addition to continued efforts to control non-point sources. PMID:249680

  19. A method for detergent-free isolation of membrane proteins in their local lipid environment.

    PubMed

    Lee, Sarah C; Knowles, Tim J; Postis, Vincent L G; Jamshad, Mohammed; Parslow, Rosemary A; Lin, Yu-Pin; Goldman, Adrian; Sridhar, Pooja; Overduin, Michael; Muench, Stephen P; Dafforn, Timothy R

    2016-07-01

    Despite the great importance of membrane proteins, structural and functional studies of these proteins present major challenges. A significant hurdle is the extraction of the functional protein from its natural lipid membrane. Traditionally achieved with detergents, purification procedures can be costly and time consuming. A critical flaw with detergent approaches is the removal of the protein from the native lipid environment required to maintain functionally stable protein. This protocol describes the preparation of styrene maleic acid (SMA) co-polymer to extract membrane proteins from prokaryotic and eukaryotic expression systems. Successful isolation of membrane proteins into SMA lipid particles (SMALPs) allows the proteins to remain with native lipid, surrounded by SMA. We detail procedures for obtaining 25 g of SMA (4 d); explain the preparation of protein-containing SMALPs using membranes isolated from Escherichia coli (2 d) and control protein-free SMALPS using E. coli polar lipid extract (1-2 h); investigate SMALP protein purity by SDS-PAGE analysis and estimate protein concentration (4 h); and detail biophysical methods such as circular dichroism (CD) spectroscopy and sedimentation velocity analytical ultracentrifugation (svAUC) to undertake initial structural studies to characterize SMALPs (∼2 d). Together, these methods provide a practical tool kit for those wanting to use SMALPs to study membrane proteins. PMID:27254461

  20. Vectorially oriented monolayers of detergent-solubilized Ca(2+) -ATPase from sarcoplasmic reticulum.

    PubMed Central

    Prokop, L A; Stongin, R M; Smith, A B; Blasie, J K; Peticolas, L J; Bean, J C

    1996-01-01

    A method for tethering proteins to solid surfaces has been utilized to form vectorially oriented monolayers of the detergent-solubilized integral membrane protein Ca(2+) -ATPase from the sarcoplasmic reticulum (SR). Bifunctional, organic self-assembled monolayers (SAMs) possessing "headgroup" binding specificity for the substrate and "endgroup" binding specificity for the enzyme were utilized to tether the enzyme to the substrate. Specifically, an amine-terminated 11-siloxyundecaneamine SAM was found to bind the Ca(2+)-ATPase primarily electrostatically. The Ca(2+)-ATPase was labeled with the fluorescent probe 5-(2-[(iodoacetyl)amino]ethyl)aminonaphthalene-1-sulfonic acid before monolayer formation. Consequently, fluorescence measurements performed on amine-terminated SAM/enzyme monolayers formed on quartz substrates served to establish the nature of protein binding. Formation of the monolayers on inorganic multilayer substrates fabricated by molecular beam epitaxy made it possible to use x-ray interferometry to determine the profile structure for the system, which was proved correct by x-ray holography. The profile structures established the vectorial orientation of the Ca(2+)-ATPase within these monolayers, to a spatial resolution of approximately 12 A. Such vectorially oriented monolayers of detergent-solubilized Ca(2+)-ATPase from SR make possible a wide variety of correlative structure/function studies, which would serve to elucidate the mechanism of Ca(2+) transport by this enzyme. Images FIGURE 8 PMID:9172737

  1. Moderate-power cw fibre lasers

    SciTech Connect

    Kurkov, Andrei S; Dianov, Evgenii M

    2004-10-31

    A review of the development and investigation of moderate-power (10{sup -1}-10{sup 2} W) cw fibre lasers is presented. The properties of optical fibres doped with rare-earth ions and methods for fabricating double-clad fibres are considered. The methods for fabrication of fibre Bragg gratings used as selective reflectors are discussed and the grating properties are analysed. The main pump schemes for double-clad fibre lasers are described. The properties of fibre lasers doped with neodymium, ytterbium, erbium, thulium, and holmium ions are also considered. The principles of fabrication of Raman converters of laser radiation based on optical fibres of different compositions are discussed and the main results of their studies are presented. It is concluded that fibre lasers described in the review can produce moderate-power radiation at any wavelength in the spectral range from 0.9 to 2 {mu}m. (review)

  2. A high-energy fibre-to-fibre connection for direct optical initiation systems

    NASA Astrophysics Data System (ADS)

    Bowden, M. D.; Knowles, S. L.

    2012-11-01

    Direct Optical Initiation (DOI), uses a moderate energy laser to shock initiate secondary explosives, via either a flyer plate or exploding metal foil. DOI offers significant performance and safety advantages over conventional electrical initiation. Optical fibres are used to transport the optical energy from the laser to the explosive device. A DOI system comprises of a laser, one or more optical fibres, and one or more laser detonators. Realisation of a DOI system is greatly eased by the use of fibre-to-fibre connections, allowing for easy integration into bulkheads or other interfaces, such as firing tanks and environmental test chambers. Fibres to fibre connectors capable of transmitting the required energy densities are not commercially available. Energy densities in the region of 35 J cm-2 are required for initiation, above the damage threshold of typical optical fibres. Laser-induced damage is typically caused by laser absorption at the input face due to imperfections in the surface polishing. To successfully transmit energy densities for DOI, a high quality fibre end face finish is required. A fibre-to-fibre connection utilizing micro-lens array injection into a large-core, tapered optical fibre, a hermetic fibre bulkhead feedthrough, and a disposable test fibre has been developed. This permits easy connection of test detonators or components, with the complex free-space to fibre injection simplified to a single operation. The damage threshold and transmission losses of the fibre-to-fibre connection have been established for each interface.

  3. LHCb Upgrade: Scintillating Fibre Tracker

    NASA Astrophysics Data System (ADS)

    Tobin, Mark

    2016-07-01

    The LHCb detector will be upgraded during the Long Shutdown 2 (LS2) of the LHC in order to cope with higher instantaneous luminosities and to read out the data at 40 MHz using a trigger-less read-out system. All front-end electronics will be replaced and several sub-detectors must be redesigned to cope with higher occupancy. The current tracking detectors downstream of the LHCb dipole magnet will be replaced by the Scintillating Fibre (SciFi) Tracker. The SciFi Tracker will use scintillating fibres read out by Silicon Photomultipliers (SiPMs). State-of-the-art multi-channel SiPM arrays are being developed to read out the fibres and a custom ASIC will be used to digitise the signals from the SiPMs. The evolution of the design since the Technical Design Report in 2014 and the latest R & D results are presented.

  4. Dietary fibre and cardiovascular health.

    PubMed

    Sánchez-Muniz, F J

    2012-01-01

    Cardiovascular disease (CVD) is the leading cause of mortality and morbidity in developed countries. CVD is an inflammatory disease associated with risk factors that include hypercholesterolemia and hypertension. Furthermore, the evolution of this disease depends on the amount of modified lipoproteins (e.g. oxidized) present in the arterial subendothelium. Diet is considered the cornerstone for CVD treatment, as it can lower not only atherogenic lipoprotein levels and degree of oxidation, but also blood pressure, thrombogenesis and concentrations of some relevant factors (e.g. homocystein).Among different diets, the Mediterranean diet stands out due to their benefits on several health benefits, in particular with regard to CVD. Rich in vegetable foods, this diet contributes both quantitatively and qualitatively to essential fibre compounds (cellulose, hemicellulose, gums, mucilages, pectins, oligosaccharides, lignins, etc.). The present paper analyzes the effects of fibre consumption on a) cholesterol and lipoprotein levels; b) systolic and diastolic blood pressures; and c) antioxidant availability and profile. Some studies and meta-analysis are revised, as the possible mechanisms by which fibre may decrease plasma total cholesterol and LDL-cholesterol and blood pressure and to act as antioxidant, as well. In addition, author's own publications regarding the effect of fibre matrix (e.g. seaweeds) on arylesterase and the gene expression of some key antioxidant enzymes are reviewed. The paper also includes data concerning the possible interaction between fibre and some hypolipemic drugs, which may make it possible to attain similar hypolipemic effects with lower dosages, with the consequent decrease in possible side effects. The review concludes with a summary of nutritional objectives related to the consumption of carbohydrates and fibre supplements. PMID:22566302

  5. Preliminary study: fibre content in pet rabbit diets, crude fibre versus total dietary fibre.

    PubMed

    Molina, J; Martorell, J; Hervera, M; Pérez-Accino, J; Fragua, V; Villaverde, C

    2015-04-01

    Fibre is an important nutrient for rabbit health, and, on commercial pet rabbit packaging, it is labelled as crude fibre (CF). In several species, it is considered that CF is not an accurate representation of the fibre content in feedstuffs. The objective of this study was to compare the CF stated on the label (CFL) with laboratory analysis of CF (CFA) and the analysed content of total dietary fibre (TDF) in different commercial pet rabbit feeds. We selected 15 commercial diets and analysed CF and TDF. A mixed model was used to evaluate differences between CFL, CFA and TDF, and linear regression was performed to study the correlation between CFL and CFA with TDF. CFA and CFL were not significantly different (p = 0.836) in the feeds studied, and both were lower than TDF (p < 0.001). The correlations between TDF and both CFA and CFL were significant (p < 0.001 and p = 0.02, respectively), but the correlation was better with CFA (R = 0.86) than with CFL (R = 0.53). As expected, TDF content was higher than CF content, an average of two times. These results suggest that the CF content in rabbit diets reported on the label is not an appropriate indicator of their total fibre content, although further work with a larger sample size is required to confirm these results.

  6. Super-tough carbon-nanotube fibres

    NASA Astrophysics Data System (ADS)

    Dalton, Alan B.; Collins, Steve; Muñoz, Edgar; Razal, Joselito M.; Ebron, Von Howard; Ferraris, John P.; Coleman, Jonathan N.; Kim, Bog G.; Baughman, Ray H.

    2003-06-01

    The energy needed to rupture a fibre (its toughness) is five times higher for spider silk than for the same mass of steel wire, which has inspired efforts to produce spider silk commercially. Here we spin 100-metre-long carbon-nanotube composite fibres that are tougher than any natural or synthetic organic fibre described so far, and use these to make fibre supercapacitors that are suitable for weaving into textiles.

  7. Portable smartphone optical fibre spectrometer

    NASA Astrophysics Data System (ADS)

    Hossain, Md. Arafat; Canning, John; Cook, Kevin; Jamalipour, Abbas

    2015-09-01

    A low cost, optical fibre based spectrometer has been developed on a smartphone platform for field-portable spectral analysis. Light of visible wavelength is collected using a multimode optical fibre and diffracted by a low cost nanoimprinted diffraction grating. A measurement range over 300 nm span (λ = 400 to 700 nm) is obtained using the smartphone CMOS chip. The spectral resolution is Δλ ~ 0.42 nm/screen pixel. A customized Android application processed the spectra on the same platform and shares with other devices. The results compare well with commercially available spectrometer.

  8. Residual Detergent Detection Method for Nondestructive Cytocompatibility Evaluation of Decellularized Whole Lung Scaffolds.

    PubMed

    Zvarova, Barbora; Uhl, Franziska E; Uriarte, Juan J; Borg, Zachary D; Coffey, Amy L; Bonenfant, Nicholas R; Weiss, Daniel J; Wagner, Darcy E

    2016-05-01

    The development of reliable tissue engineering methods using decellularized cadaveric or donor lungs could potentially provide a new source of lung tissue. The vast majority of current lung decellularization protocols are detergent based and incompletely removed residual detergents may have a deleterious impact on subsequent scaffold recellularization. Detergent removal and quality control measures that rigorously and reliably confirm removal, ideally utilizing nondestructive methods, are thus critical for generating optimal acellular scaffolds suitable for potential clinical translation. Using a modified and optimized version of a methylene blue-based detergent assay, we developed a straightforward, noninvasive method for easily and reliably detecting two of the most commonly utilized anionic detergents, sodium deoxycholate (SDC) and sodium dodecyl sulfate (SDS), in lung decellularization effluents. In parallel studies, we sought to determine the threshold of detergent concentration that was cytotoxic using four different representative human cell types utilized in the study of lung recellularization: human bronchial epithelial cells, human pulmonary vascular endothelial cells (CBF12), human lung fibroblasts, and human mesenchymal stem cells. Notably, different cells have varying thresholds for either SDC or SDS-based detergent-induced cytotoxicity. These studies demonstrate the importance of reliably removing residual detergents and argue that multiple cell lines should be tested in cytocompatibility-based assessments of acellular scaffolds. The detergent detection assay presented here is a useful nondestructive tool for assessing detergent removal in potential decellularization schemes or for use as a potential endpoint in future clinical schemes, generating acellular lungs using anionic detergent-based decellularization protocols.

  9. Evaluation of oxidative stress and genetic damage caused by detergents in the zebrafish Danio rerio (Cyprinidae).

    PubMed

    Sobrino-Figueroa, Alma S

    2013-08-01

    Detergents are used in large quantities and some of their ingredients are highly toxic to aquatic organisms. In the present study the toxicity (lipid peroxidation) and genotoxic (frequency of DNA strand breaks) effects were evaluated in the gill and liver tissues of zebrafish (Danio rerio), exposed for 16days to a sublethal concentration (CL10) of two commercial detergents (laundry and dishwasher use) and an anionic surfactant: alkyl lauryl sulfonate (LAS). The results demonstrated high toxicity with dishwasher detergent, resulting in high lipid peroxidation levels (MDA malondialdehyde evaluation). No differences in MDA concentrations were found among fish exposed to laundry detergent and organisms exposed to LAS. In the genetic damage evaluation, significant differences in the number of cells with DNA strand breaks (comets) were observed: the fish exposed to dishwasher detergent presented the highest number of damaged cells (79%), in comparison with those exposed to other products (laundry and LAS) and the control group (8% damaged cells). The toxicity of dishwasher detergent (biological detergent containing enzymes and perfume) was higher than the value observed with LAS. Laundry detergent does not contain enzymes or perfume and its toxicity was similar to LAS. Since detergents are complex mixtures of different substances, in which additive and/or synergistic effects may occur, the deleterious effect caused by the dishwasher detergent was probably due to the combined effects of the ingredients of detergent.

  10. A gas chromatography-mass spectrometry method to monitor detergents removal from a membrane protein sample.

    PubMed

    Shi, Chaowei; Han, Fang; Xiong, Ying; Tian, Changlin

    2009-12-01

    In membrane protein biochemical and structural studies, detergents are used to mimic membrane environment and maintain functional, stable conformation of membrane proteins in the absence of lipid bilayers. However, detergent concentration, esp. molar ratio of membrane protein to detergent is usually unknown. Here, a gas chromatography-mass spectrometry selected ion monitoring (GC-MS-SIM) method was developed to quantify four detergents which are frequently used in membrane protein structural studies. To remove excessive detergents, a filtered centrifugation using Centricon tubes was applied. A membrane protein Ig-Beta fragment in four different detergent micelles was exemplified. Detergent concentrations in the upper and lower fraction of the Centricon tube were measured after each round of centrifugation. The results were very consistent to basic properties of detergent micelles in aqueous solvents. Therefore, coupling of GC-MS-SIM and detergent removal by Centricon tubes, detergents concentration, esp. molar ratio of membrane protein to detergent could be controlled, which will expedite membrane protein structural and biochemical studies.

  11. Evaluation of oxidative stress and genetic damage caused by detergents in the zebrafish Danio rerio (Cyprinidae).

    PubMed

    Sobrino-Figueroa, Alma S

    2013-08-01

    Detergents are used in large quantities and some of their ingredients are highly toxic to aquatic organisms. In the present study the toxicity (lipid peroxidation) and genotoxic (frequency of DNA strand breaks) effects were evaluated in the gill and liver tissues of zebrafish (Danio rerio), exposed for 16days to a sublethal concentration (CL10) of two commercial detergents (laundry and dishwasher use) and an anionic surfactant: alkyl lauryl sulfonate (LAS). The results demonstrated high toxicity with dishwasher detergent, resulting in high lipid peroxidation levels (MDA malondialdehyde evaluation). No differences in MDA concentrations were found among fish exposed to laundry detergent and organisms exposed to LAS. In the genetic damage evaluation, significant differences in the number of cells with DNA strand breaks (comets) were observed: the fish exposed to dishwasher detergent presented the highest number of damaged cells (79%), in comparison with those exposed to other products (laundry and LAS) and the control group (8% damaged cells). The toxicity of dishwasher detergent (biological detergent containing enzymes and perfume) was higher than the value observed with LAS. Laundry detergent does not contain enzymes or perfume and its toxicity was similar to LAS. Since detergents are complex mixtures of different substances, in which additive and/or synergistic effects may occur, the deleterious effect caused by the dishwasher detergent was probably due to the combined effects of the ingredients of detergent. PMID:23542746

  12. Ochratoxin A displaces claudins from detergent resistant membrane microdomains.

    PubMed

    Lambert, Daniel; Padfield, Philip J; McLaughlin, John; Cannell, Stephanie; O'Neill, Catherine A

    2007-06-29

    Ochratoxin A (OchA) is a food-borne mycotoxin with multiple effects in vivo. Previously, we have demonstrated that the toxin can significantly impair the barrier function of the gut epithelial cell line, Caco-2. Barrier disruption involved loss of claudins 3 and 4, but not claudin 1 from the tight junction complex. In this study, we demonstrate for the first time, that OchA is able to remove claudins 3 and 4 from the detergent insoluble membrane microdomains associated with the tight junctions. However, cholesterol distribution within the microdomain was unaffected by the toxin. In addition, the thiol antioxidant, N-acetyl cysteine, preserved the microdomain localisation of claudins and also the barrier function of Caco-2 cells. This work suggests that OchA-mediated barrier toxicity is due to removal of claudins from detergent insoluble membrane microdomains. Moreover, loss of microdomain association may be due to oxidative events.

  13. Detergent Stabilized Nanopore Formation Kinetics of an Anthrax Protein

    NASA Astrophysics Data System (ADS)

    Peterson, Kelby

    2015-03-01

    This summer research project funded through the Society of Physics Students Internship Program and The National Institute of Standards and Technology focused on optimization of pore formation of Protective Antigen protein secreted by Bacillus Anthraces. This experiment analyzes the use of N-tetradecylphosphocholine (FOS-14 Detergent) to stabilize the water soluble protein, protective antigen protein (PA63) to regulate the kinetics of pore formation in a model bilayer lipid membrane. The FOS-14 Detergent was tested under various conditions to understand its impact on the protein pore formation. The optimization of this channel insertion is critical in preparing samples of oriented for neutron reflectometry that provide new data to increase the understanding of the protein's structure.

  14. Interactions of lipids and detergents with a viral ion channel protein: molecular dynamics simulation studies.

    PubMed

    Rouse, Sarah L; Sansom, Mark S P

    2015-01-22

    Structural studies of membrane proteins have highlighted the likely influence of membrane mimetic environments (i.e., lipid bilayers versus detergent micelles) on the conformation and dynamics of small α-helical membrane proteins. We have used molecular dynamics simulations to compare the conformational dynamics of BM2 (a small α-helical protein from the membrane of influenza B) in a model phospholipid bilayer environment with its behavior in protein-detergent complexes with either the zwitterionic detergent dihexanoylphosphatidylcholine (DHPC) or the nonionic detergent dodecylmaltoside (DDM). We find that DDM more closely resembles the lipid bilayer in terms of its interaction with the protein, while the short-tailed DHPC molecule forms "nonphysiological" interactions with the protein termini. We find that the intrinsic micelle properties of each detergent are conserved upon formation of the protein-detergent complex. This implies that simulations of detergent micelles may be used to help select optimal conditions for experimental studies of membrane proteins.

  15. Detergent quantification in membrane protein samples and its application to crystallization experiments.

    PubMed

    Prince, Chelsy C; Jia, Zongchao

    2013-12-01

    The structural characterization of membrane proteins remains a challenging field, largely because the use of stabilizing detergents is required. Researchers must first select a suitable detergent for the solubility and stability of their protein during in vitro studies. In addition, an appropriate concentration of detergent in membrane protein samples can be essential for protein solubility, stability, and experimental success. For example, in membrane protein crystallography, detergent concentration in the crystallization drop can be a critical parameter influencing crystal growth. Over the past decade, multiple techniques have been developed for the measurement of detergent concentration using a wide variety of strategies. These methods include colorimetric reactions, which target specific detergent classes, and analytical techniques applicable to a wide variety of detergents. This review will summarize and discuss the available options. It will be a useful resource to those selecting a strategy that best fits their experimental requirements and available instruments.

  16. Skeletal muscle fibre types in the dog.

    PubMed Central

    Latorre, R; Gil, F; Vázquez, J M; Moreno, F; Mascarello, F; Ramirez, G

    1993-01-01

    Using a variety of histochemical methods we have investigated the mATPase reaction of skeletal muscle fibres in the dog. Types I, IIA, IIDog (peculiar to the dog) and IIC fibres were identified. The results reveal that the interpretation of the fibre type composition depends on the methods used. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 PMID:8226288

  17. Friction and wear of human hair fibres

    NASA Astrophysics Data System (ADS)

    Bowen, James; Johnson, Simon A.; Avery, Andrew R.; Adams, Michael J.

    2016-06-01

    An experimental study of the tribological properties of hair fibres is reported, and the effect of surface treatment on the evolution of friction and wear during sliding. Specifically, orthogonally crossed fibre/fibre contacts under a compressive normal load over a series of 10 000 cycle studies are investigated. Reciprocating sliding at a velocity of 0.4 mm s‑1, over a track length of 0.8 mm, was performed at 18 °C and 40%–50% relative humidity. Hair fibres retaining their natural sebum were studied, as well as those stripped of their sebum via hexane cleaning, and hair fibres conditioned using a commercially available product. Surface topography modifications resulting from wear were imaged using scanning electron microscopy and quantified using white light interferometry. Hair fibres that presented sebum or conditioned product at the fibre/fibre junction exhibited initial coefficients of friction at least 25% lower than those that were cleaned with hexane. Coefficients of friction were observed to depend on the directionality of sliding for hexane cleaned hair fibres after sufficient wear cycles that cuticle lifting was present, typically on the order 1000 cycles. Cuticle flattening was observed for fibre/fibre junctions exposed to 10 mN compressive normal loads, whereas loads of 100 mN introduced substantial cuticle wear and fibre damage.

  18. Friction and wear of human hair fibres

    NASA Astrophysics Data System (ADS)

    Bowen, James; Johnson, Simon A.; Avery, Andrew R.; Adams, Michael J.

    2016-06-01

    An experimental study of the tribological properties of hair fibres is reported, and the effect of surface treatment on the evolution of friction and wear during sliding. Specifically, orthogonally crossed fibre/fibre contacts under a compressive normal load over a series of 10 000 cycle studies are investigated. Reciprocating sliding at a velocity of 0.4 mm s-1, over a track length of 0.8 mm, was performed at 18 °C and 40%-50% relative humidity. Hair fibres retaining their natural sebum were studied, as well as those stripped of their sebum via hexane cleaning, and hair fibres conditioned using a commercially available product. Surface topography modifications resulting from wear were imaged using scanning electron microscopy and quantified using white light interferometry. Hair fibres that presented sebum or conditioned product at the fibre/fibre junction exhibited initial coefficients of friction at least 25% lower than those that were cleaned with hexane. Coefficients of friction were observed to depend on the directionality of sliding for hexane cleaned hair fibres after sufficient wear cycles that cuticle lifting was present, typically on the order 1000 cycles. Cuticle flattening was observed for fibre/fibre junctions exposed to 10 mN compressive normal loads, whereas loads of 100 mN introduced substantial cuticle wear and fibre damage.

  19. Effect of Detergents on Galactoside Binding by Melibiose Permeases.

    PubMed

    Amin, Anowarul; Hariharan, Parameswaran; Chae, Pil Seok; Guan, Lan

    2015-09-29

    The effect of various detergents on the stability and function of the melibiose permeases of Escherichia coli (MelBEc) and Salmonella typhimurium (MelBSt) was studied. In n-dodecyl-β-d-maltoside (DDM) or n-undecyl-β-d-maltoside (UDM), WT MelBSt binds melibiose with an affinity similar to that in the membrane. However, with WT MelBEc or MelBSt mutants (Arg141 → Cys, Arg295 → Cys, or Arg363 → Cys), galactoside binding is not detected in these detergents, but binding to the phosphotransferase protein IIA(Glc) is maintained. In the amphiphiles lauryl maltose neopentyl glycol (MNG-3) or glyco-diosgenin (GDN), galactoside binding with all of the MelB proteins is observed, with slightly reduced affinities. MelBSt is more thermostable than MelBEc, and the thermostability of either MelB is largely increased in MNG-3 or GDN. Therefore, the functional defect with DDM or UDM likely results from the relative instability of the sensitive MelB proteins, and stability, as well as galactoside binding, is retained in MNG-3 or GDN. Furthermore, isothermal titration calorimetry of melibiose binding with MelBSt shows that the favorable entropic contribution to the binding free energy is decreased in MNG-3, indicating that the conformational dynamics of MelB is restricted in this detergent.

  20. Effect of Detergents on Galactoside Binding by Melibiose Permeases.

    PubMed

    Amin, Anowarul; Hariharan, Parameswaran; Chae, Pil Seok; Guan, Lan

    2015-09-29

    The effect of various detergents on the stability and function of the melibiose permeases of Escherichia coli (MelBEc) and Salmonella typhimurium (MelBSt) was studied. In n-dodecyl-β-d-maltoside (DDM) or n-undecyl-β-d-maltoside (UDM), WT MelBSt binds melibiose with an affinity similar to that in the membrane. However, with WT MelBEc or MelBSt mutants (Arg141 → Cys, Arg295 → Cys, or Arg363 → Cys), galactoside binding is not detected in these detergents, but binding to the phosphotransferase protein IIA(Glc) is maintained. In the amphiphiles lauryl maltose neopentyl glycol (MNG-3) or glyco-diosgenin (GDN), galactoside binding with all of the MelB proteins is observed, with slightly reduced affinities. MelBSt is more thermostable than MelBEc, and the thermostability of either MelB is largely increased in MNG-3 or GDN. Therefore, the functional defect with DDM or UDM likely results from the relative instability of the sensitive MelB proteins, and stability, as well as galactoside binding, is retained in MNG-3 or GDN. Furthermore, isothermal titration calorimetry of melibiose binding with MelBSt shows that the favorable entropic contribution to the binding free energy is decreased in MNG-3, indicating that the conformational dynamics of MelB is restricted in this detergent. PMID:26352464

  1. Effect of detergents on galactoside binding by melibiose permeases

    PubMed Central

    Amin, Anowarul; Hariharan, Parameswaran; Chae, Pil Seok; Guan, Lan

    2015-01-01

    The effect of various detergents on the stability and function of melibiose permeases of Escherichia coli (MelBEc) or Salmonella typhimurium (MelBSt) were studied. In n-dodecyl-β-d-maltoside (DDM) or n-undecyl-β-d-maltoside (UDM), WT MelBSt binds melibiose with an affinity similar to that in the membrane. However, with WT MelBEc or MelBSt mutants (Arg141→Cys, Arg295→Cys or Arg363→Cys), galactoside binding is not detected in these detergents, but binding to the phosphotransferase protein IIAGlc is maintained. In the amphiphiles lauryl maltose neopentyl glycol (MNG-3) or glyco-diosgenin (GDN), galactoside binding with all the MelB proteins is observed, with slightly reduced affinities. MelBSt is more thermostable than MelBEc, and the thermostability of either MelB is largely increased in MNG-3 or GDN. Therefore, the functional defect with DDM or UDM likely results from relative instability of the sensitive MelB proteins, and stability, as well as galactoside binding, is retained in MNG-3 or GDN. Furthermore, isothermal titration calorimetry of melibiose binding with MelBSt shows that the favorable entropic contribution to the binding free energy is decreased in MNG-3, indicating that the conformational dynamics of MelB is restricted in this detergent. PMID:26352464

  2. Detergent alkaline proteases: enzymatic properties, genes, and crystal structures.

    PubMed

    Saeki, Katsuhisa; Ozaki, Katsuya; Kobayashi, Tohru; Ito, Susumu

    2007-06-01

    Subtilisin-like serine proteases from bacilli have been used in various industrial fields worldwide, particularly in the production of laundry and automatic dishwashing detergents. They belong to family A of the subtilase superfamily, which is composed of three clans, namely, true subtilisins, high-alkaline proteases, and intracellular proteases. We succeeded in the large-scale production of a high-alkaline protease (M-protease) from alkaliphilic Bacillus clausii KSM-K16, and the enzyme has been introduced into compact heavy-duty laundry detergents. We have also succeeded in the industrial-scale production of a new alkaline protease, KP-43, which was originally resistant to chemical oxidants and to surfactants, produced by alkaliphilic Bacillus sp. strain KSM-KP43 and have incorporated it into laundry detergents. KP-43 and related proteases form a new clan, oxidatively stable proteases, in subtilase family A. In this review, we describe the enzymatic properties, gene sequences, and crystal structures of M-protease, KP-43, and related enzymes. PMID:17630120

  3. Partial purification and properties of a laundry detergent compatible alkaline protease from a newly isolated Bacillus species Y.

    PubMed

    Mala, M; Srividya, S

    2010-09-01

    Alkaline protease production by a newly isolated Bacillus species from laundry soil was studied for detergent biocompatibility. From its morphological and nucleotide sequence (about 1.5 kb) of its 16S rDNA it was identified as Bacillus species with similarity to Bacillus species Y (Gen Bank entry: ABO 55095), and close homology with Bacillus cohnii YN-2000 (Gen Bank entry: ABO23412). Partial purification of the enzyme by ammonium sulfate (50-70% saturation) yielded 8-fold purity. Casein zymography and Sodium dodecylsulphate-Polyacrylamide gel electrophoresis (SDS-PAGE) of the partially purified enzyme revealed two isozymes of molecular sizes approximately 66 kDa and 18 kDa, respectively. The enzyme was most active at pH 12 and 50°C. At pH 12 the enzyme was stable for 5 h and retained 60% activity. The enzyme retained 44% activity at 50°C up to 2 h. The protease showed good hydrolysis specificity with different substrates tested. The presence of Mn(2+), Co(2+) and ethylenediaminetetracetic acid (EDTA) showed profound increase in protease activity. The protease of Bacillus species Y showed excellent stability and compatibility with three locally available detergents (Kite, Tide and Aerial) up to 3 h retaining almost 70-80% activity and 10-20% activity at room temperature (30°C) and 50°C, respectively, indicating the potential role of this enzyme for detergent application.

  4. Detergent-free isolation, characterization, and functional reconstitution of a tetrameric K+ channel: The power of native nanodiscs

    PubMed Central

    Dörr, Jonas M.; Koorengevel, Martijn C.; Schäfer, Marre; Prokofyev, Alexander V.; Scheidelaar, Stefan; van der Cruijsen, Elwin A. W.; Dafforn, Timothy R.; Baldus, Marc; Killian, J. Antoinette

    2014-01-01

    A major obstacle in the study of membrane proteins is their solubilization in a stable and active conformation when using detergents. Here, we explored a detergent-free approach to isolating the tetrameric potassium channel KcsA directly from the membrane of Escherichia coli, using a styrene-maleic acid copolymer. This polymer self-inserts into membranes and is capable of extracting membrane patches in the form of nanosize discoidal proteolipid particles or “native nanodiscs.” Using circular dichroism and tryptophan fluorescence spectroscopy, we show that the conformation of KcsA in native nanodiscs is very similar to that in detergent micelles, but that the thermal stability of the protein is higher in the nanodiscs. Furthermore, as a promising new application, we show that quantitative analysis of the co-isolated lipids in purified KcsA-containing nanodiscs allows determination of preferential lipid–protein interactions. Thin-layer chromatography experiments revealed an enrichment of the anionic lipids cardiolipin and phosphatidylglycerol, indicating their close proximity to the channel in biological membranes and supporting their functional relevance. Finally, we demonstrate that KcsA can be reconstituted into planar lipid bilayers directly from native nanodiscs, which enables functional characterization of the channel by electrophysiology without first depriving the protein of its native environment. Together, these findings highlight the potential of the use of native nanodiscs as a tool in the study of ion channels, and of membrane proteins in general. PMID:25512535

  5. Fibre ring cavity semiconductor laser

    SciTech Connect

    Duraev, V P; Medvedev, S V

    2013-10-31

    This paper presents a study of semiconductor lasers having a polarisation maintaining fibre ring cavity. We examine the operating principle and report main characteristics of a semiconductor ring laser, in particular in single- and multiple-frequency regimes, and discuss its application areas. (lasers)

  6. Characterization of the Activity and Stability of Amylase from Saliva and Detergent: Laboratory Practicals for Studying the Activity and Stability of Amylase from Saliva and Various Commercial Detergents

    ERIC Educational Resources Information Center

    Valls, Cristina; Rojas, Cristina; Pujadas, Gerard; Garcia-Vallve, Santi; Mulero, Miquel

    2012-01-01

    This article presents two integrated laboratory exercises intended to show students the role of [alpha]-amylases (AAMYs) in saliva and detergents. These laboratory practicals are based on the determination of the enzymatic activity of amylase from saliva and different detergents using the Phadebas test (quantitative) and the Lugol test…

  7. Slc5a8, a Na+-coupled high-affinity transporter for short-chain fatty acids, is a conditional tumour suppressor in colon that protects against colitis and colon cancer under low-fibre dietary conditions.

    PubMed

    Gurav, Ashish; Sivaprakasam, Sathish; Bhutia, Yangzom D; Boettger, Thomas; Singh, Nagendra; Ganapathy, Vadivel

    2015-07-15

    Mammalian colon harbours trillions of bacteria under physiological conditions; this symbiosis is made possible because of a tolerized response from the mucosal immune system. The mechanisms underlying this tolerogenic phenomenon remain poorly understood. In the present study we show that Slc5a8 (solute carrier gene family 5a, member 8), a Na(+)-coupled high-affinity transporter in colon for the bacterial fermentation product butyrate, plays a critical role in this process. Among various immune cells in colon, dendritic cells (DCs) are unique not only in their accessibility to luminal contents but also in their ability to induce tolerogenic phenotype in T-cells. We found that DCs exposed to butyrate express the immunosuppressive enzymes indoleamine 2,3-dioxygenase 1 (IDO1) and aldehyde dehydrogenase 1A2 (Aldh1A2), promote conversion of naive T-cells into immunosuppressive forkhead box P3(+) (FoxP3(+)) Tregs (regulatory T-cells) and suppress conversion of naive T-cells into pro-inflammatory interferon (IFN)-γ-producing cells. Slc5a8-null DCs do not induce IDO1 and Aldh1A2 and do not generate Tregs or suppress IFN-γ-producing T-cells in response to butyrate. We also provide in vivo evidence for an obligatory role for Slc5a8 in suppression of IFN-γ-producing T-cells. Furthermore, Slc5a8 protects against colitis and colon cancer under conditions of low-fibre intake but not when dietary fibre intake is optimal. This agrees with the high-affinity nature of the transporter to mediate butyrate entry into cells. We conclude that Slc5a8 is an obligatory link between dietary fibre and mucosal immune system via the bacterial metabolite butyrate and that this transporter is a conditional tumour suppressor in colon linked to dietary fibre content.

  8. Elastic fibres in health and disease.

    PubMed

    Baldwin, Andrew K; Simpson, Andreja; Steer, Ruth; Cain, Stuart A; Kielty, Cay M

    2013-08-20

    Elastic fibres are insoluble components of the extracellular matrix of dynamic connective tissues such as skin, arteries, lungs and ligaments. They are laid down during development, and comprise a cross-linked elastin core within a template of fibrillin-based microfibrils. Their function is to endow tissues with the property of elastic recoil, and they also regulate the bioavailability of transforming growth factor β. Severe heritable elastic fibre diseases are caused by mutations in elastic fibre components; for example, mutations in elastin cause supravalvular aortic stenosis and autosomal dominant cutis laxa, mutations in fibrillin-1 cause Marfan syndrome and Weill-Marchesani syndrome, and mutations in fibulins-4 and -5 cause autosomal recessive cutis laxa. Acquired elastic fibre defects include dermal elastosis, whereas inflammatory damage to fibres contributes to pathologies such as pulmonary emphysema and vascular disease. This review outlines the latest understanding of the composition and assembly of elastic fibres, and describes elastic fibre diseases and current therapeutic approaches.

  9. Immunogenicity of recombinant class 1 protein from Neisseria meningitidis refolded into phospholipid vesicles and detergent.

    PubMed

    Niebla, O; Alvarez, A; Martín, A; Rodríguez, A; Delgado, M; Falcón, V; Guillén, G

    2001-05-14

    The possibility of eliciting bactericidal antibodies against a recombinant class 1 protein (P1) from Neisseria meningitidis, joined to the first 45 amino acids of the neisserial LpdA protein (PM82), was examined. P1 was produced in Escherichia coli as intracellular inclusion bodies, from which it was purified and reconstituted by (a) inclusion into phospholipid vesicles and detergent and (b) refolding in 0.1% SDS. When Balb/c mice were immunised, high titres of subtype-specific bactericidal antibodies against P1 were obtained in both cases. These results suggest that in spite of being a denaturing agent, it is possible to use SDS to reconstitute the P1 protein in a conformation that exposes the immunodominat regions.

  10. Functional characterization of detergent-decellularized equine tendon extracellular matrix for tissue engineering applications.

    PubMed

    Youngstrom, Daniel W; Barrett, Jennifer G; Jose, Rod R; Kaplan, David L

    2013-01-01

    Natural extracellular matrix provides a number of distinct advantages for engineering replacement orthopedic tissue due to its intrinsic functional properties. The goal of this study was to optimize a biologically derived scaffold for tendon tissue engineering using equine flexor digitorum superficialis tendons. We investigated changes in scaffold composition and ultrastructure in response to several mechanical, detergent and enzymatic decellularization protocols using microscopic techniques and a panel of biochemical assays to evaluate total protein, collagen, glycosaminoglycan, and deoxyribonucleic acid content. Biocompatibility was also assessed with static mesenchymal stem cell (MSC) culture. Implementation of a combination of freeze/thaw cycles, incubation in 2% sodium dodecyl sulfate (SDS), trypsinization, treatment with DNase-I, and ethanol sterilization produced a non-cytotoxic biomaterial free of appreciable residual cellular debris with no significant modification of biomechanical properties. These decellularized tendon scaffolds (DTS) are suitable for complex tissue engineering applications, as they provide a clean slate for cell culture while maintaining native three-dimensional architecture.

  11. The 'sticky business' of cleaning gas-phase membrane proteins: a detergent oriented perspective.

    PubMed

    Borysik, Antoni J; Robinson, Carol V

    2012-11-14

    In recent years the properties of gas-phase detergent clusters have come under close scrutiny due in part to their participation in the analysis of intact membrane protein complexes by mass spectrometry. The detergent molecules that cover the protein complex are removed in the gas-phase by thermally agitating the ions by collision-induced dissociation. This process however, is not readily controlled and can frequently result in the disruption of protein structure. Improved methods of releasing proteins from detergent clusters are clearly required. To facilitate this the structural properties of detergent clusters along with the mechanistic details of their dissociation need to be understood. Pivotal to understanding the properties of gas-phase detergent clusters is the technique of ion mobility mass spectrometry. This technique can be used to assign polydisperse detergent clusters and provide information about their geometries and packing densities. In this article we consider the shapes of detergent clusters and show that these clusters possess geometries that are inconsistent with those in solution. We analyse the distributions of clusters in detail using tandem mass spectrometry and suggest that the mean charge of clusters formed from certain detergents is governed by electrostatic repulsion. We discuss the dissociation of detergent clusters and propose that detergent evaporation it a key process in the protection of protein complexes during high energy collisions in the gas-phase.

  12. Detergent properties influence the stability of the glycophorin A transmembrane helix dimer in lysophosphatidylcholine micelles.

    PubMed

    Stangl, Michael; Veerappan, Anbazhagan; Kroeger, Anja; Vogel, Peter; Schneider, Dirk

    2012-12-19

    Detergents might affect membrane protein structures by promoting intramolecular interactions that are different from those found in native membrane bilayers, and fine-tuning detergent properties can be crucial for obtaining structural information of intact and functional transmembrane proteins. To systematically investigate the influence of the detergent concentration and acyl-chain length on the stability of a transmembrane protein structure, the stability of the human glycophorin A transmembrane helix dimer has been analyzed in lyso-phosphatidylcholine micelles of different acyl-chain length. While our results indicate that the transmembrane protein is destabilized in detergents with increasing chain-length, the diameter of the hydrophobic micelle core was found to be less crucial. Thus, hydrophobic mismatch appears to be less important in detergent micelles than in lipid bilayers and individual detergent molecules appear to be able to stretch within a micelle to match the hydrophobic thickness of the peptide. However, the stability of the GpA TM helix dimer linearly depends on the aggregation number of the lyso-PC detergents, indicating that not only is the chemistry of the detergent headgroup and acyl-chain region central for classifying a detergent as harsh or mild, but the detergent aggregation number might also be important.

  13. Health hazards associated with laundry detergent pods - United States, May-June 2012.

    PubMed

    2012-10-19

    During May and early June 2012, the Carolinas Poison Center and the Poison Control Center at the Children's Hospital of Philadelphia received four reports of children with vomiting, mental status changes, and respiratory distress after ingesting the contents of laundry detergent pods. Laundry detergent pods are single-load capsules that contain concentrated liquid detergent within a water-soluble membrane that dissolves when in contact with moisture. Laundry detergent pods were introduced in the U.S. market in 2010, and multiple manufacturers now sell laundry detergent packaged in pods (2-4). On May 17, 2012, CDC and the American Association of Poison Control Centers (AAPCC) began tracking and characterizing reported exposures to laundry detergent from pods. During May 17-June 17, 2012, poison centers reported 1,008 laundry detergent exposures to the National Poison Data System (NPDS), of which 485 (48%) exposures involved laundry detergent pods. Age was recorded for 481 exposures, of which 454 (94%) exposures involved children aged ≤5 years. Among children aged ≤5 years, a significantly greater proportion of those exposed to laundry detergent from pods had gastrointestinal and respiratory adverse health effects and mental status changes compared with those with non-pod laundry detergent exposures. Parents and caregivers should keep laundry detergent pods, as well as other household cleaning products, out of reach and out of sight of children. Health-care providers should be aware that exposure to laundry detergent from pods might be associated with adverse health effects more often than exposure to non-pod laundry detergents.

  14. The Effect of Detergents on the Morphology and Immunomodulatory Activity of Malassezia furfur

    PubMed Central

    Kim, Su-Han; Ko, Hyun-Chang; Kwon, Kyung-Sool; Oh, Chang-Keun

    2009-01-01

    Background Several workers have found that Malassezia are capable of suppressing cytokine release and downregulating the phagocytic function of monocytes. But lipid-depleted Malassezia furfur (M. furfur) extracts have also been shown to induce increased production of TNF-α, IL-6 and IL-1β in monocytes. We thought that the detergents in shampoos or soaps could change the composition of the lipid in the M. furfur cell wall. Objective We studied whether detergents affect the morphology of M. furfur and if the inflammatory cytokine profiles change in the monocytes treated with detergent-treated M. furfur. Methods Commonly used detergents such as sodium lauryl sulfate, ammonium lauryl sulfate and tween-80 were respectively added to the modified Leeming-Notman's media. M. furfur was cultivated in each media (detergent-added or untreated). Thereafter, the surface morphology of the yeast was evaluated by scanning and transmission electron microscopy. The cytokine profiles of monocytes, which were treated by M. furfur with or without detergents, were also evaluated. Results The detergent-treated M. furfur were similar to the lipid-extracted form of M. furfur on the electron microscopic study, with a recessed, withered surface and with thinner and rather electron transparent cell walls than the detergent-untreated M. furfur. The levels of TNF-α were higher in monocytes treated with detergent-treated Malassezia than that in the monocytes treated with the detergent-untreated Malassezia (p<0.05). Conclusion According to the findings in this study, it could be inferred that the detergents in shampoos or soaps affect the lipid layers of the Malassezia cell wall and these lipid-extracted Malassezia induce or aggravate some inflammatory conditions. But to correlate the relationship between detergents and Malassezia-associated diseases, in vivo experiments that will focus on short-term contact with detergents in real life conditions should be done. PMID:20523770

  15. Effect of partial replacement of forage neutral detergent fiber with by-product neutral detergent fiber in close-up diets on periparturient performance of dairy cows.

    PubMed

    Dann, H M; Carter, M P; Cotanch, K W; Ballard, C S; Takano, T; Grant, R J

    2007-04-01

    The objective of this study was to determine the effect of partial replacement of forage neutral detergent fiber (NDF) with by-product NDF in close-up diets of dairy cattle on periparturient metabolism and performance. Holstein cows (n = 45) and heifers (n = 19) were fed corn silage-based diets containing 1) 30% oat hay, or 2) 15% oat hay and 15% beet pulp from d -21 relative to expected parturition until parturition. After parturition, all animals received the same lactation diet. Animals were group-fed from d -21 to -10 relative to expected parturition and fed individually from d -10 until 14 d in milk. Animals were required to have at least 5 d of prepartum dry matter intake (DMI) data to remain on the study. Data were analyzed as a randomized design and subjected to ANOVA using the MIXED procedure of SAS. Close-up diet did not affect DMI, total tract nutrient digestibility, energy balance, or serum content of nonesterified fatty acids and beta-hydroxybutyrate during the last 5 d prepartum. Prepartum body weight and body condition score were similar between treatments. There was no carryover effect of close-up diet on DMI, energy balance, milk yield, body weight, body condition score, or serum content of nonesterified fatty acids and beta-hydroxybutyrate during the first 14 d in milk. In summary, partial replacement of forage NDF (oat hay) with by-product NDF (beet pulp) did not affect periparturient metabolism or performance.

  16. Interactions of dietary fibre and omega-3-rich oil with protein in surimi gels developed with salt substitute.

    PubMed

    Debusca, Alicia; Tahergorabi, Reza; Beamer, Sarah K; Partington, Susan; Jaczynski, Jacek

    2013-11-01

    Most Western populations have insufficient intake of fibre and ω-3 polyunsaturated fatty acids (PUFAs), while sodium intake greatly exceeds the recommended maximum. Surimi seafood is not currently fortified with these nutraceutical ingredients. Alaska pollock surimi seafood was developed with salt substitute and fortified with either 6g/100g of fibre or 10 g/100g of ω-3 oil (flax:algae:menhaden, 8:1:1) or fibre+ω-3 oil (6g/100g of fibre+10 g/100g of ω-3 oil). The objective was to determine effects of the dietary fortification on physicochemical properties of surimi. Fortification with either dietary fibre or ω-3 oil alone or in combination enhanced (P<0.05) rheological and textural characteristics. The combined fortification had a synergistic effect on rheological properties. This indicates greater gelation of surimi in the presence of fibre+ω-3 oil, suggesting their interaction with surimi myofibrillar proteins. Fibre results in protein dehydration increasing protein concentration; while oil is immobilised by protein filling void spaces in the gel matrix. Differential scanning calorimetry showed that fibre and ω-3 oil did not interfere with normal denaturation of surimi proteins. Colour properties were only slightly affected (P<0.05). Fortification of surimi with fibre and ω-3 oil resulted in a quality product that could be useful in developing surimi products with nutritional benefits. PMID:23768348

  17. UCP3 Protein Regulation in Human Skeletal Muscle Fibre Types I, IIa and IIx is Dependent on Exercise Intensity

    PubMed Central

    Russell, Aaron P; Somm, Emmanuel; Praz, Manu; Crettenand, Antoinette; Hartley, Oliver; Melotti, Astrid; Giacobino, Jean-Paul; Muzzin, Patrick; Gobelet, Charles; Dériaz, Olivier

    2003-01-01

    It has been proposed that mitochondrial uncoupling protein 3 (UCP3) behaves as an uncoupler of oxidative phosphorylation. In a cross-sectional study, UCP3 protein levels were found to be lower in all fibre types of endurance-trained cyclists as compared to healthy controls. This decrease was greatest in the type I oxidative fibres, and it was hypothesised that this may be due to the preferential recruitment of these fibres during endurance training. To test this hypothesis, we compared the effects of 6 weeks of endurance (ETr) and sprint (STr) running training on UCP3 mRNA expression and fibre-type protein content using real-time PCR and immunofluorescence techniques, respectively. UCP3 mRNA and protein levels were downregulated similarly in ETr and STr (UCP3 mRNA: by 65 and 50 %, respectively; protein: by 30 and 27 %, respectively). ETr significantly reduced UCP3 protein content in type I, IIa and IIx muscle fibres by 54, 29 and 16 %, respectively. STr significantly reduced UCP3 protein content in type I, IIa and IIx muscle fibres by 24, 31 and 26 %, respectively. The fibre-type reductions in UCP3 due to ETr, but not STr, were significantly different from each other, with the effect being greater in type I than in type IIa, and in type IIa than in type IIx fibres. As a result, compared to STr, ETr reduced UCP3 expression significantly more in fibre type I and significantly less in fibre types IIx. This suggests that the more a fibre is recruited, the more it adapts to training by a decrease in its UCP3 expression. In addition, the more a fibre type depends on fatty acid β oxidation and oxidative phosphorylation, the more it responds to ETr by a decrease in its UCP3 content. PMID:12794174

  18. Conventional E-glass fibre light guides: self-sensing composite based on sol gel cladding

    NASA Astrophysics Data System (ADS)

    Wang, L.; Kister, G.; Ralph, B.; Talbot, J. D. R.; Fernando, G. F.

    2004-02-01

    The aim of this study was to modify conventional reinforcing E-glass fibres to enable them to act as optical waveguides and subsequently as sensor devices. This required the glass fibres to be coated with a relatively homogeneous coating with a corresponding refractive index that was lower than the E-glass fibre (1.56). Although a range of coating materials are available, this study focused on using materials that are generally used as sizing agents for glass fibres to improve the adhesion to the matrix. Two different methods based on conventional sol gel processing were used to obtain crack-free coatings. In the first method, tetraethoxysilane (TEOS) and polyvinyl alcohol were used as precursors. In the second method, acid-catalysed solutions of TEOS mixed with 3-glycidoxypropyltrimethoxysilane were used as precursors. UV visible transmission results showed that the films had low absorption and high transparency in the visible range. The refractive indices of the films were found to be a function of the molar fractions of the major chemical components. A simple impregnation procedure was used to apply the coating to the E-glass fibre bundles. The light transmission characteristics of the coated fibres along with their mechanical properties were evaluated. The sol gel coatings were shown to be effective in converting the conventional E-glass fibres into light guides.

  19. Assessing secondary structure of a dyed wool fibre by means of FTIR and FTR spectroscopies

    NASA Astrophysics Data System (ADS)

    Pielesz, A.; Freeman, H. S.; Wesełucha-Birczyńska, A.; Wysocki, M.; Włochowicz, A.

    2003-06-01

    The paper describes changes in the structure of a wool fibre dyed with model azo dyes. These were direct dyes, non-genotoxic derivatives of carcinogenic benzidine, synthesized specially for the purpose of the experiment. The non-mutagenic benzidine derivatives were: 2,2'-dimethyl-5,5'-dipropoxybenzidine and 5,5'-dipropoxybenzidine. Using FTIR, changes in secondary structure of fibres were assessed in three measuring ranges: 3600-3000, 1700-1400 and 1000-1300 cm -1. The dyes were found to distinctively affect wave-number shifts of amide A, amide I bands and in the fingerprint area around 1050 cm -1. It seems that these three areas are related to the sites in which dyes bind with wool fibre keratin. In FTR spectra, the focus was on assessing the changes of peptide bond configuration in the area of amide I, disulfide area of cystine and the area of the interaction between dyes and wool fibre keratin, i.e. 1250-1600 cm -1. For analysis, three kinds of materials were selected: (1) raw wool fibres, (2) fibres subjected to deuteration and treated with formic acid, (3) wool fabric. Each of them was dyed with the model azo dyes. The results obtained by both spectroscopies allow for identifying the functional groups responsible for the binding of dyes with keratin fibre.

  20. An accessory protein required for anchoring and assembly of amyloid fibres in B. subtilis biofilms.

    PubMed

    Romero, Diego; Vlamakis, Hera; Losick, Richard; Kolter, Roberto

    2011-06-01

    Cells within Bacillus subtilis biofilms are held in place by an extracellular matrix that contains cell-anchored amyloid fibres, composed of the amyloidogenic protein TasA. As biofilms age they disassemble because the cells release the amyloid fibres. This release appears to be the consequence of incorporation of D-tyrosine, D-leucine, D-tryptophan and D-methionine into the cell wall. Here, we characterize the in vivo roles of an accessory protein TapA (TasA anchoring/assembly protein; previously YqxM) that serves both to anchor the fibres to the cell wall and to assemble TasA into fibres. TapA is found in discrete foci in the cell envelope and these foci disappear when cells are treated with a mixture of D-amino acids. Purified cell wall sacculi retain a functional form of this anchoring protein such that purified fibres can be anchored to the sacculi in vitro. In addition, we show that TapA is essential for the proper assembly of the fibres. Its absence results in a dramatic reduction in TasA levels and what little TasA is left produces only thin fibres that are not anchored to the cell. PMID:21477127

  1. Effect of sterilisation on dietary fibre and physicochemical properties of onion by-products.

    PubMed

    Benítez, Vanesa; Mollá, Esperanza; Martín-Cabrejas, María A; Aguilera, Yolanda; López-Andréu, Francisco J; Esteban, Rosa M

    2011-07-15

    Food industries are forced to develop productions without secondary residues. Therefore, there is a considerable emphasis on the recovery, recycling and upgrading of wastes. The possibility has been suggested for the conversion of onion waste into food ingredients, but with a stabilisation treatment being necessary. The objective of this work was to study the effect of sterilisation on fibre fractions, fibre composition and physicochemical properties of onion by-products to evaluate the use of sterilised onion by-products as a source of fibre. Sterilisation produced insoluble dietary fibre decreases and soluble dietary fibre increases, improving the soluble:insoluble ratio. Uronic acids of insoluble dietary fibre were partly solubilised and losses of cellulose and Klason lignin were observed. Physicochemical properties slightly changed with sterilisation. Sterilised by-products showed less oil holding capacity, cation exchange capacity and swelling capacity than control ones, although their physicochemical properties were generally higher than those of cellulose. Therefore, sterilisation would be considered a good method to stabilise onion by-products to use as a potential dietary fibre ingredient.

  2. Fibre-mediated physiological effects of raw and processed carrots in humans.

    PubMed

    Wisker, E; Schweizer, T F; Daniel, M; Feldheim, W

    1994-10-01

    Fibre-mediated physiological effects of raw and processed carrots were investigated in twenty-four young women under strict dietary control in two randomized crossover studies. For 3 weeks between 405 and 688 g of either raw frozen, blanched or canned carrots (first study), or raw or raw frozen carrots (second study) were consumed in addition to a low-fibre basal diet. Carrots provided 15 g dietary fibre (DF)/d. Total DF intake was 16.0 to 19.0 g (control periods) and 31 to 34 g (experimental periods). Faecal bulking effects of raw and processed carrots were similar (between 2.4 and 3.7 g additional stool/g carrot fibre in the diet). Faecal excretion of dry matter, fibre, and protein also increased significantly during carrot consumption. Fermentability of carrot fibre constituents was high (91-94%) and independent of processing, in spite of differences in the distribution of soluble and insoluble fibre and in the texture of raw and processed carrots. There was no effect of either type of carrot on serum total and high-density-lipoprotein-cholesterol or on faecal bile acid excretion.

  3. Development of detergent additives for automotive fuels in other countries

    SciTech Connect

    Zakharova, E.L.; Emel`yanov, V.E.; Deineko, P.S.

    1994-09-01

    With increasing demands on environmental protection and with the production of reformulated unleaded motor fuels, new and effective detergent additives are urgently needed. A number of monographs and scientific works have been devoted to problems involved in the development and application of such additives. Since the mid-1980s in the United States and certain other countries, a crisis has been noted in the application of detergent additives. It has been found that certain types of detergents not only fail to give the required cleaning effect, but even promote the formation of deposits. This situation can be attributed primarily to the development of automotive gasoline engines with direct fuel injection. In the United States in 1989, about 90% of all automotive vehicles were equipped with such engines, which have very definite advantages in fuel economy, less smoking, and a number of other areas. However, after a few thousand kilometers of travel, the characteristics of these engines deteriorate, and undesirable changes are observed, including excessive fuel consumption, a reduction of the vehicle speed, and increased contents of carbon monoxide in the exhaust. These changes occur because of deposit formation in the fuel intake system, particularly on the intake valves. As the deposits continue to accumulate, the engines gradually experience an increase in octane number demand for engine operation without knocking. This phenomenon, which is known in American publications as {open_quotes}octane requirement increase{close_quotes} or ORI (Russian initialism RTOCh, literal translation, {open_quotes}increase of requirements for octane number{close_quotes}), continues until a certain equilibrium octane number is reached. This equilibrium value may change, depending on the engine design and other factors. In all cases, however, the ORI of modern engines is significant, amount to 2-14 octane numbers.

  4. Restoration of antibody binding to blotted meningococcal outer membrane proteins using various detergents.

    PubMed

    Wedege, E; Bryn, K; Frøholm, L O

    1988-10-01

    Restoration of IgG antibody binding to heat-denatured meningococcal outer membrane proteins has been studied on immunoblots with a series of 14 detergents. Nitrocellulose strips with the blotted proteins were incubated with the detergents and sera from human volunteers vaccinated with meningococcal membrane proteins. Zwitterionic and ionic detergents, containing substituted quarternary ammonium or amino groups with a minimum of 10 C atoms in the alkyl chain, restored the antigenicity of the serotype-specific class 2 porin protein. The concentrations of the Zwittergent detergents necessary for activation decreased with increasing alkyl chain length of the homologues. Only zwitterionic detergents renatured the class 1 protein. Both proteins were weakly antigenic in the presence of the nonionic detergents Triton X-100 and Tween 20. Meningococcal lipopolysaccharide restored antibody binding to the porin, but not to the class 1 protein. Similar concentrations of lipopolysaccharides from two other gram-negative bacteria had no effect.

  5. Cleanser, Detergent, Personal Care Product, and Pretreatment Evaluation

    NASA Technical Reports Server (NTRS)

    Adam, Niklas; Carrier, Chris; Vega, Leticia; Casteel, Michael; Verostko, chuck; Pickering, Karen

    2011-01-01

    The purpose of the Cleanser, Detergent, Personal Care Product, and Pretreatment Evaluation & Selection task is to identify the optimal combination of personal hygiene products, crew activities, and pretreatment strategies to provide the crew with sustainable life support practices and a comfortable habitat. Minimal energy, mass, and crew time inputs are desired to recycle wastewater during long duration missions. This document will provide a brief background on the work this past year supporting the ELS Distillation Comparison Test, issues regarding use of the hygiene products originally chosen for the test, methods and results used to select alternative products, and lessons learned from testing.

  6. In Vitro Evaluation of Seven Cationic Detergents as Antiplaque Agents

    PubMed Central

    Tanzer, J. M.; Slee, A. M.; Kamay, B.; Scheer, E. R.

    1979-01-01

    The bactericidal efficacy of seven cationic detergents was studied in vitro against intact performed plaques of representative strains of four oral dental plaque-forming microorganisms: Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, and Actinomyces naeslundii. Both absolute (plaque bactericidal index) and relative (chlorhexidine coefficient) indexes of antiplaque activity were established. Only cetyltrimethylammonium bromide was more efficacious than the reference agent, the bisbiguanide chlorhexidine, for the apparently more potent tooth-adherent cariogenic and periodontopathic elements, respectively, of the in vivo plaque microflora, S. mutans and A. viscosus. PMID:464568

  7. Mechanical, degradation and cytocompatibility properties of magnesium coated phosphate glass fibre reinforced polycaprolactone composites.

    PubMed

    Liu, Xiaoling; Hasan, Muhammad S; Grant, David M; Harper, Lee T; Parsons, Andrew J; Palmer, Graham; Rudd, Chris D; Ahmed, Ifty

    2014-11-01

    Retention of mechanical properties of phosphate glass fibre reinforced degradable polyesters such as polycaprolactone and polylactic acid in aqueous media has been shown to be strongly influenced by the integrity of the fibre/polymer interface. A previous study utilising 'single fibre' fragmentation tests found that coating with magnesium improved the fibre and matrix interfacial shear strength. Therefore, the aim of this study was to investigate the effects of a magnesium coating on the manufacture and characterisation of a random chopped fibre reinforced polycaprolactone composite. Short chopped strand non-woven phosphate glass fibre mats were sputter coated with degradable magnesium to manufacture phosphate glass fibre/polycaprolactone composites. The degradation behaviour (water uptake, mass loss and pH change of the media) of these polycaprolactone composites as well as of pure polycaprolactone was investigated in phosphate buffered saline. The Mg coated fibre reinforced composites revealed less water uptake and mass loss during degradation compared to the non-coated composites. The cations released were also explored and a lower ion release profile for all three cations investigated (namely Na(+), Mg(2+) and Ca(2+)) was seen for the Mg coated composite samples. An increase of 17% in tensile strength and 47% in tensile modulus was obtained for the Mg coated composite samples. Both flexural and tensile properties were investigated and a higher retention of mechanical properties was obtained for the Mg coated fibre reinforced composite samples up to 10 days immersion in PBS. Cytocompatibility study showed both composite samples (coated and non-coated) had good cytocompatibility with human osteosarcoma cell line.

  8. Digestive physiological outcomes related to polydextrose and soluble maize fibre consumption by healthy adult men.

    PubMed

    Boler, Brittany M Vester; Serao, Mariana C Rossoni; Bauer, Laura L; Staeger, Michael A; Boileau, Thomas W; Swanson, Kelly S; Fahey, George C

    2011-12-01

    The objective of the present study was to evaluate digestive physiological outcomes elicited by functional fibres fed to healthy adult men. A total of twenty-one healthy adult men were utilised in a cross-over design. Each subject received polydextrose (PDX) or soluble maize fibre (SCF) (21 g/d) or no supplemental fibre (no fibre control; NFC) in a snack bar. Periods were 21 d and faeces were collected during the last 5 d of each period. Food intake, including fibre intake, did not differ among treatments. Flatulence (P = 0·001) and distention (P = 0·07) were greatest when subjects consumed PDX or SCF. Reflux was greater (P = 0·04) when subjects consumed SCF compared with NFC. All tolerance scores were low ( < 2·5), indicating only slight discomfort. Faecal ammonia, 4-methylphenol, indole and branched-chain fatty acid concentrations were decreased (P < 0·01) when subjects consumed the functional fibre sources compared with NFC. Faecal acetate, propionate and butyrate concentrations were lower (P < 0·05) when subjects consumed PDX compared with SCF and NFC. Faecal pH was lower (P = 0·01) when subjects consumed SCF compared with NFC, while PDX was intermediate. Faecal wet weight was greatest (P = 0·03) when subjects consumed SCF compared with NFC. Faecal dry weight tended to be greater (P = 0·07) when subjects consumed PDX compared with NFC. The functional fibres led to 1·4 and 0·9 g (PDX and SCF, respectively) increases in faecal dry mass per g supplemental fibre intake. Bifidobacterium spp. concentrations were greater (P < 0·05) when subjects consumed SCF compared with NFC. These functional fibres appear to be beneficial to gut health while leading to minimal gastrointestinal upset. PMID:21736814

  9. Investigating the particle to fibre transition threshold during electrohydrodynamic atomization of a polymer solution.

    PubMed

    Husain, O; Lau, W; Edirisinghe, M; Parhizkar, M

    2016-08-01

    Electrohydrodynamic atomization (EHDA) is a key research area for producing micro and nano-sized structures. This process can be categorized into two main operating regimes: electrospraying for particle generation and electrospinning for fibre production. Producing particles/fibres of the desired size or morphology depends on two main factors; properties of the polymeric solution used and the processing conditions including flow rate, applied voltage and collection distance. In this work the particle-fibre transition region was analyzed by changing the polymer concentration of PLGA poly (lactic-co-glycolic acid) in acetone between 2 and 25wt%. Subsequently the processing conditions were adjusted to study the optimum transition parameters. Additionally the EHDA configuration was also modified by adding a metallic plate to observe the deposition area. The diameter and the distance of the plate from the capillary tip were adjusted to investigate variations in particle and fibre morphologies as well. It was found that complete transition from particles to fibres occurs at 20wt% indicating concentration to be the dominant criterion. Low flow rates yielded fibres without beads. However the applied voltage and distance between the tip of the nozzle jetting the polymer solution and collector (working distance) did not yield definitive results. Reducing the collector distance and increasing applied voltages produces smooth as well as beaded fibres. Addition of a metal plate reduces particle size by ~1μm; the fibre size increases especially with increasing plate diameter while bead density and size reduces when the disc is fixed closer to the capillary tip. Additionally, the deposition area is reduced by 70% and 57% with the addition of metal plates of 30mm and 60mm, respectively. The results indicate that a metal plate can be utilized further to tune the particle/fibre size and morphology and this also significantly increases the yield of EHDA process which is currently a

  10. Characterizing detergent mediated reconstitution of viral protein M2 in large unilamellar vesicles

    NASA Astrophysics Data System (ADS)

    Freyre, Mariel; Grossman, Carl; Crouch, Catherine; Howard, Kathleen

    2015-03-01

    Influenza M2 is a model membrane protein whose function is to induce curvature and vesicle formation in the process of viral infection. To study embedded M2 in synthetic phospholipid vesicles (large unilamellar vesicles or LUVs), a concentration of detergent and buffer is optimized to balance protein solubility, proteolipid concentration, and LUV stability. Adding detergent also causes the LUVs to partially disassemble and form micelles, which warrants detergent removal to restore LUV integrity. We explore methods of measuring the coexistence of detergent micelles and LUVs to track the different phases of the system as detergent is removed. A combination of Fluorescence Correlation Spectroscopy, Dynamic Light Scattering, and chemical analysis are used to measure the properties of this system. With detergent/LUV number densities as high as 5 we find coexistence of micelles and LUVs at 50% to 60%. As the detergent is removed, the micelle concentration drops to lower than 30% while detergent levels drop to nearly zero. These results may indicate a polydispersed LUV size distribution after detergent mediated reconstitution. Supported by HHMI and Swarthmore College.

  11. Calorimetric Quantification of Cyclodextrin-Mediated Detergent Extraction for Membrane-Protein Reconstitution.

    PubMed

    Textor, Martin; Keller, Sandro

    2016-01-01

    For many in vitro studies, purified membrane proteins need to be reconstituted from detergent micelles into lipid bilayers to regain their native structures and functions. Stoichiometric complexation of detergent by cyclodextrin provides a tightly controllable strategy for detergent extraction. Here, we describe a practical approach making use of isothermal titration calorimetry to obtain a complete set of thermodynamic parameters that allows for quantitative prediction of the transition from micelles to bilayer membranes during reconstitution. These parameters include the dissociation constant of the cyclodextrin/detergent inclusion complex, the critical micellar concentration of the detergent, and the phase boundaries of the lipid/detergent phase diagram. The underlying theoretical framework involves linked equilibria among all pseudophases, as described previously (Textor, Vargas, & Keller, 2015). This chapter focuses on practical aspects of the approach and discusses caveats and calorimetry-specific details of data analysis. With the entire parameter set at hand, exploration of different reconstitution trajectories within the lipid/detergent phase diagram is possible. Together with the straightforward control over the rate of detergent extraction offered by cyclodextrin complexation, this opens the possibility of systematically tuning and optimizing the reconstitution process of membrane proteins. Provided some particular precautions are taken, the approach can be adapted to many other combinations of proteins, lipids, detergents, and cyclodextrins.

  12. Evaluation of a new lipase from Staphylococcus sp. for detergent additive capability.

    PubMed

    Chauhan, Mamta; Chauhan, Rajinder Singh; Garlapati, Vijay Kumar

    2013-01-01

    Lipases are the enzymes of choice for laundry detergent industries owing to their triglyceride removing ability from the soiled fabric which eventually reduces the usage of phosphate-based chemical cleansers in the detergent formulation. In the present study, a partially purified bacterial lipase from Staphylococcus arlettae JPBW-1 isolated from the rock salt mine has been assessed for its triglyceride removing ability by developing a presoak solution so as to use lipase as an additive in laundry detergent formulations. The effects of selected surfactants, commercial detergents, and oxidizing agents on lipase stability were studied in a preliminary evaluation for its further usage in the industrial environment. Partially purified lipase has shown good stability in presence of surfactants, commercial detergents, and oxidizing agents. Washing efficiency has been found to be enhanced while using lipase with 0.5% nonionic detergent than the anioinic detergent. The wash performance using 0.5% wheel with 40 U lipase at 40°C in 45 min results in maximum oil removal (62%) from the soiled cotton fabric. Hence, the present study opens the new era in enzyme-based detergent sector for formulation of chemical-free detergent using alkaline bacterial lipase.

  13. A skin sensitization safety assessment of a new bleach activator technology in detergent applications.

    PubMed

    Roggeband, R; Helmlinger, G; Smith, I; Wilhelm, K-P; Ryan, C A; Gerberick, G F

    2002-04-01

    A new chemical called nonanoyl amido caproylacid oxybenzenesulphonate (NACAOBS) is being developed for use as a bleach activator in laundry detergents. Bleach activators, like NACAOBS, are typically used at levels between 2% and 6% in laundry detergents. NACAOBS is stable in aqueous solutions, but undergoes rapid perhydrolysis when combined with water and peroxygen bleach in laundry detergents. Animal testing demonstrated that NACAOBS, as a raw material, is a weak skin sensitizer. Clinical testing, including extended simulated laundry pretreatment, human repeat insult patch testing and home use testing was then undertaken, following sufficient reassurance of 1) the weak sensitization potential of the substance, 2) its rapid degradation in laundry wash solutions and, consequently, 3) low-to-negligible consumer dermal exposures to the native substance. Results confirmed the skin sensitization safety profile of laundry detergents containing NACAOBS, namely the absence of any reaction suggestive of contact sensitization (even under exaggerated dermal exposure conditions in a detergent matrix), and a skin compatibility profile comparable to that of current detergents. Further confirmation of the skin safety profile was obtained from a successful 12-month market test of a granular detergent containing 3.6% of the new substance, during which not a single adverse skin reaction was reported. In addition, NOBS (an oxybenzenesulphonate structural analogue to NACAOBS) has similar toxicological properties and has been safely marketed in detergents at similar levels for many years. It can be concluded that the likelihood of NACAOBS to induce skin sensitization or even elicit allergic reactions in consumer detergent use scenarios is negligible.

  14. Evaluation of a New Lipase from Staphylococcus sp. for Detergent Additive Capability

    PubMed Central

    Chauhan, Mamta; Chauhan, Rajinder Singh; Garlapati, Vijay Kumar

    2013-01-01

    Lipases are the enzymes of choice for laundry detergent industries owing to their triglyceride removing ability from the soiled fabric which eventually reduces the usage of phosphate-based chemical cleansers in the detergent formulation. In the present study, a partially purified bacterial lipase from Staphylococcus arlettae JPBW-1 isolated from the rock salt mine has been assessed for its triglyceride removing ability by developing a presoak solution so as to use lipase as an additive in laundry detergent formulations. The effects of selected surfactants, commercial detergents, and oxidizing agents on lipase stability were studied in a preliminary evaluation for its further usage in the industrial environment. Partially purified lipase has shown good stability in presence of surfactants, commercial detergents, and oxidizing agents. Washing efficiency has been found to be enhanced while using lipase with 0.5% nonionic detergent than the anioinic detergent. The wash performance using 0.5% wheel with 40 U lipase at 40°C in 45 min results in maximum oil removal (62%) from the soiled cotton fabric. Hence, the present study opens the new era in enzyme-based detergent sector for formulation of chemical-free detergent using alkaline bacterial lipase. PMID:24106703

  15. Trace metal analysis of coal fly ash collected plain and on a quartz fibre filter.

    PubMed

    Laitinen, T; Revitzer, H; Tolvanen, M

    1996-02-01

    A simple, uniform procedure has been developed for microwave-based digestion of fly ash samples collected from the hoppers of an electrostatic precipitator (ESP), or collected from flue gases on a heat-resistant quartz fibre filter and for subsequent atomic absorption spectrometric analysis of trace metals (Be, Cd, Co, Cr, Cu, Mn, Ni, Pb, V and Zn). HNO(3), HCl, HF and mixtures have been tested as digestion acids. The combination of HNO(3) and HF has been found to be efficient for the digestion of fly ash samples with and without quartz fibre filter material. In spite of the complicated matrix, results with satisfactory accuracy and precision (relative standard deviation below 10% for most of the elements) have been obtained. In the case of analysis of fly ash together with a quartz fibre filter, the calibration curve has to be determined by standard addition to a blank solution containing a dissolved blank quartz fibre filter. PMID:15048429

  16. Asbestos fibre release by corroded and weathered asbestos-cement products.

    PubMed

    Spurny, K R

    1989-01-01

    A description is given of portable equipment and a method of sampling and measuring asbestos fibre emissions from solid plane surfaces of asbestos-cement products (roofs and facades). Asbestos-cement products, e.g., roof tiles, contain as much as 11-12% of chrysotile asbestos. As a result of continuing exposure to the weather and to acid rain, the surface of asbestos-cement products becomes corroded and weathered. Cement particles, asbestos fibres and agglomerates of particles and fibres are therefore released from the surface and dispersed in air and water. The method described has been used to measure asbestos fibre emissions and ambient air concentrations in the Federal Republic of Germany over the period 1984-1986.

  17. N-type thermoelectric recycled carbon fibre sheet with electrochemically deposited Bi2Te3

    NASA Astrophysics Data System (ADS)

    Pang, E. J. X.; Pickering, S. J.; Chan, A.; Wong, K. H.

    2012-06-01

    An N-type thermoelectric recycled carbon fibre sheet with bismuth telluride coating has been successfully synthesised through an electrodeposition technique. The Seebeck coefficient and electrical properties of the combined recycled carbon fibre sheet and bismuth telluride films are reported. Classification of the crystal structure, surface morphology and the elemental composition of the resulting deposits are methodically characterised by XRD, SEM and EDX correspondingly. Cyclic voltammetry is also carried out in nitric acid solutions to investigate the right range of deposition potential. An N-type thermoelectric sheet was successfully synthesised with the highest attainable Seebeck coefficient of -54 μV/k with an electrical resistivity of 8.9 × 10-5 ohm m. The results shows slight differences in morphologies and thermoelectric properties for the films deposited at varying deposition potential. The increase in thermoelectrical properties of the recycled carbon fibre is in line with the development of using coated recycled fibre for thermoelectrical applications.

  18. N-type thermoelectric recycled carbon fibre sheet with electrochemically deposited Bi2Te3

    NASA Astrophysics Data System (ADS)

    Pang, E. J. X.; Pickering, S. J.; Chan, A.; Wong, K. H.; Lau, P. L.

    2012-09-01

    An N-type thermoelectric recycled carbon fibre sheet with bismuth telluride coating has been successfully synthesised through an electro-deposition technique. The Seebeck coefficient and electrical properties of the combined recycled carbon fibre sheet and bismuth telluride films are reported. Classification of the crystal structure, surface morphology and the elemental composition of the resulting deposits are methodically characterised by XRD, SEM and EDX. Cyclic voltammetry is also carried out in nitric acid solutions to investigate the right range of deposition potential. The synthesis N-type thermoelectric sheet has a highest attainable Seebeck coefficient of -54 μV K-1 and an electrical resistivity of 8.9×10-5 Ω m. The results show slight differences in morphologies and thermoelectric properties for the films deposited at varying deposition potential. The increase in thermoelectrical properties of the recycled carbon fibre is in line with the development of using coated recycled fibre for thermoelectrical applications.

  19. Elastic fibres in health and disease.

    PubMed

    Kielty, Cay M

    2006-08-08

    Elastic fibres are a major class of extracellular matrix fibres that are abundant in dynamic connective tissues such as arteries, lungs, skin and ligaments. Their structural role is to endow tissues with elastic recoil and resilience. They also act as an important adhesion template for cells, and they regulate growth factor availability. Mutations in major structural components of elastic fibres, especially elastin, fibrillins and fibulin-5, cause severe, often life-threatening, heritable connective tissue diseases such as Marfan syndrome, supravalvular aortic stenosis and cutis laxa. Elastic-fibre function is also frequently compromised in damaged or aged elastic tissues. The ability to regenerate or engineer elastic fibres and tissues remains a significant challenge, requiring improved understanding of the molecular and cellular basis of elastic-fibre biology and pathology, and ability to regulate the spatiotemporal expression and assembly of its molecular components.

  20. Interactions of melittin, a preprotein model, with detergents.

    PubMed

    Knöppel, E; Eisenberg, D; Wickner, W

    1979-09-18

    Bee venom melittin is a water-soluble tetramer of identical polypeptide chains. Each chain has 26 residues. The 20 N-terminal residues are hydrophobic and the 6 C-terminal residues are basic. Melittin has been shown to integrate into natural and synthetic membranes and to lyse a wide variety of cells. To understand how a water-soluble protein can spontaneously partition into a membrane, we have studied the interaction of melittin with micelles of deoxycholate (DOC), Brij 58, and sodium dodecyl sulfate (NaDodSO4). Circular dichroism spectra showed that NaDodSO4, an ionic detergent, and Brij 58, a nonionic detergent, caused similar major changes in the protein's conformation. Gel filtration studies revealed that melittin forms mixed micelles with either Brij or DOC. The melittin-DOC mixed micelles have 2 mol of DOC per mol of melittin. Cross-linking studies with dimethyl suberimidate confirmed that the protein is a tetramer and showed that it becomes monomeric either in mixed micelles with Brij or DOC or in butanol. Despite this major structural change of melittin in the presence of an amphiphile, the covalently cross-linked form is as active in human erythrocyte lysis as the native protein.

  1. Lipid rafts and detergent-resistant membranes in epithelial keratinocytes.

    PubMed

    McGuinn, Kathleen P; Mahoney, Mỹ G

    2014-01-01

    Our understanding of the plasma membrane has markedly increased since Singer and Nicolson proposed the fluid mosaic model in 1972. While their revolutionary theory of the lipid bilayer remains largely valid, it is now known that lipids and proteins are not randomly dispersed throughout the plasma membrane but instead may be organized within membrane microdomains, commonly referred to as lipid rafts. Lipid rafts are highly dynamic, detergent resistant, and enriched with both cholesterol and glycosphingolipids. The two main types are flotillin-rich planar lipid rafts and caveolin-rich caveolae. It is proposed that flotillin and caveolin proteins regulate cell communication by compartmentalizing and interacting with signal transduction proteins within their respective lipid microdomains. Consequently, membrane rafts play an important role in vital cellular functions including migration, invasion, and signaling; thus, alterations in their microenvironment can initiate signaling pathways that affect cellular function and behavior. Therefore, the identification of lipid rafts and their associated proteins is integral to the study of transmembrane signaling. Here, we review the current standard protocols and biochemical approaches used to isolate and define raft proteins from epithelial cells and tissues. Furthermore, in Section 3 of this chapter, detailed protocols are offered for isolating lipid rafts by subjection to detergent and sucrose density centrifugation, as well as an approach for selectively isolating caveolae. Methods to manipulate rafts with treatments such as methyl-β-cyclodextrin and flotillin III are also described.

  2. Effects of starch and fibre in pelleted diets on nutritional status of mule deer (Odocoileus hemionus) fawns.

    PubMed

    McCusker, S; Shipley, L A; Tollefson, T N; Griffin, M; Koutsos, E A

    2011-08-01

    To compare the effects of a low-starch, high-fibre diet [LSHF; 51.6% neutral detergent fibre (NDF), 3.0% starch, 14.8% crude protein (CP)] and a high-starch, low-fibre diet (HSLF; 33.3% NDF, 20.0% starch, 19.6% CP) on the nutritional status of captive exotic ruminants, 16 mule deer (Odocoileus hemionus) were fed one of these two diets ad libitum with ≤25% alfalfa hay cubes from 10 days to 68 weeks of age. During five sampling periods beginning in November and spaced 6-12 weeks apart thereafter, feed intake, rumen and blood chemistry, faecal scores, growth and body condition were measured. Dry matter intake, digestible energy intake, time spent ruminating and feeding and blood acetate concentration were greater for deer fed LSHF (p < 0.05 for all). Lower dietary CP led to reduced blood urea nitrogen for deer consuming LSHF (p = 0.004). Deer had the same faecal scores, growth and body fat among treatments (all p > 0.05). These findings show pelleted diets with less starch, more fibre, and reduced protein met the energy and protein requirements of growing mule deer, a medium-sized browsing ruminant, as well as traditional grain-based diets while more closely mimicking natural forages and stimulating a more natural feeding behaviour.

  3. Ytterbium-doped fibre laser with a Bragg grating reflector written in a multimode fibre

    SciTech Connect

    Kurkov, Andrei S; Grukh, Dmitrii A; Medvedkov, O I; Paramonov, Vladimir M; Dianov, Evgenii M

    2005-04-30

    An efficient cladding-pumped Yb-doped fibre laser with a Bragg grating written in a multimode graded-index fibre is fabricated for the first time. The laser emits one transverse mode with a slope efficiency of 60%. The resonator design proposed in the paper can be used for the development of high-power fibre lasers with an increased fibre core diameter. (lasers)

  4. OPTICAL FIBRES AND FIBREOPTIC SENSORS: Polarisation reflectometry of anisotropic optical fibres

    NASA Astrophysics Data System (ADS)

    Konstantinov, Yurii A.; Kryukov, Igor'I.; Pervadchuk, Vladimir P.; Toroshin, Andrei Yu

    2009-11-01

    Anisotropic, polarisation-maintaining fibres have been studied using a reflectometer and integrated optic polariser. Linearly polarised pulses were launched into the fibre under test at different angles between their plane of polarisation and the main optical axis of the fibre. A special procedure for the correlation analysis of these reflectograms is developed to enhance the reliability of the information about the longitudinal optical uniformity ofanisotropic fibres.

  5. Large-scale fibre-array multiplexing

    SciTech Connect

    Cheremiskin, I V; Chekhlova, T K

    2001-05-31

    The possibility of creating a fibre multiplexer/demultiplexer with large-scale multiplexing without any basic restrictions on the number of channels and the spectral spacing between them is shown. The operating capacity of a fibre multiplexer based on a four-fibre array ensuring a spectral spacing of 0.7 pm ({approx} 10 GHz) between channels is demonstrated. (laser applications and other topics in quantum electronics)

  6. Microbial products activate monocytic cells through detergent-resistant membrane microdomains.

    PubMed

    Epelman, Slava; Berenger, Byron; Stack, Danuta; Neely, Graham G; Ma, Ling Ling; Mody, Christopher H

    2008-12-01

    Patients with cystic fibrosis suffer recurrent pulmonary infections that are characterized by an overactive yet ineffective and destructive inflammatory response that is associated with respiratory infections by Pseudomonas aeruginosa, a pathogen that produces a number of phlogistic molecules. To better understand this process, we used exoenzyme S (ExoS), one of the key P. aeruginosa-secreted exoproducts, which is known to stimulate cells via the Toll-like receptor (TLR) pathway. We found that ExoS induced proinflammatory cytokine production via the NF-kappaB, Erk1/2, and Src kinase pathways. Because Src kinases are concentrated within cholesterol-containing, detergent-resistant membrane microdomains (DRM) (also called lipid rafts) and DRM act as signaling platforms and amplifiers on the surface of cells, we addressed the role of DRM in ExoS signaling. ExoS bound directly to a subset of DRM and induced the phosphorylation of multiple proteins within DRM, including Src kinases. Disruption of DRM by cholesterol extraction prevented NF-kappaB and Erk 1/2 activation and TNF-alpha production in response to ExoS. Activation of monocytic cells by other TLR and Nod-like receptor agonists, such as lipoteichoic acid, lipopolysaccharide, and peptidoglycan, were also dependent on DRM, and disruption prevented TNF-alpha production. Disruption of DRM did not prevent ExoS binding but did release the Src kinase, Lyn, from the DRM fraction into the detergent-soluble fraction, a site in which Src kinases are not active. These studies show that ExoS, a TLR agonist, requires direct binding to DRM for optimal signaling, which suggests that DRM are possible therapeutic targets in cystic fibrosis.

  7. Solubilization and characterization of the anthrax toxin pore in detergent micelles.

    PubMed

    Vernier, Gregory; Wang, Jie; Jennings, Laura D; Sun, Jianjun; Fischer, Audrey; Song, Likai; Collier, R John

    2009-09-01

    Proteolytically activated Protective Antigen (PA) moiety of anthrax toxin self-associates to form a heptameric ring-shaped oligomer (the prepore). Acidic pH within the endosome converts the prepore to a pore that serves as a passageway for the toxin's enzymatic moieties to cross the endosomal membrane. Prepore is stable in solution under mildly basic conditions, and lowering the pH promotes a conformational transition to an insoluble pore-like state. N-tetradecylphosphocholine (FOS14) was the only detergent among 110 tested that prevented aggregation without dissociating the multimer into its constituent subunits. FOS14 maintained the heptamers as monodisperse, insertion-competent 440-kDa particles, which formed channels in planar phospholipid bilayers with the same unitary conductance and ability to translocate a model substrate protein as channels formed in the absence of detergent. Electron paramagnetic resonance analysis detected pore-like conformational changes within PA on solubilization with FOS14, and electron micrograph images of FOS14-solubilized pore showed an extended, mushroom-shaped structure. Circular dichroïsm measurements revealed an increase in alpha helix and a decrease in beta structure in pore formation. Spectral changes caused by a deletion mutation support the hypothesis that the 2beta2-2beta3 loop transforms into the transmembrane segment of the beta-barrel stem of the pore. Changes caused by selected point mutations indicate that the transition to alpha structure is dependent on residues of the luminal 2beta11-2beta12 loop that are known to affect pore formation. Stabilizing the PA pore in solution with FOS14 may facilitate further structural analysis and a more detailed understanding of the folding pathway by which the pore is formed.

  8. Crystal structure of a self-assembling lipopeptide detergent at 1.20 Å

    SciTech Connect

    Ho, Dona N.; Pomroy, Neil C.; Cuesta-Seijo, Jose A.; Prive, Gilbert G.

    2008-10-21

    Lipopeptide detergents (LPDs) are a new class of amphiphile designed specifically for the structural study of integral membrane proteins. The LPD monomer consists of a 25-residue peptide with fatty acyl chains linked to side chains located at positions 2 and 24 of the peptide. LPDs are designed to form {alpha}-helices that self-assemble into cylindrical micelles, providing a more natural interior acyl chain packing environment relative to traditional detergents. We have determined the crystal structure of LPD-12, an LPD coupled to two dodecanoic acids, to a resolution of 1.20 {angstrom}. The LPD-12 monomers adopt the target conformation and associate into cylindrical octamers as expected. Pairs of helices are strongly associated as Alacoil-type antiparallel dimers, and four of these dimers interact through much looser contacts into assemblies with approximate D{sub 2} symmetry. The aligned helices form a cylindrical shell with a hydrophilic exterior that protects an interior hydrophobic cavity containing the 16 LPD acyl chains. Over 90% of the methylene/methyl groups from the acylated side chains are visible in the micelle interiors, and {approx}90% of these adopt trans dihedral angle conformations. Dodecylmaltoside (DDM) was required for the crystallization of LPD-12, and we find 10-24 ordered DDM molecules associated with each LPD assembly, resulting in an overall micelle molecular weight of {approx}30 kDa. The structures confirm the major design objectives of the LPD framework, and reveal unexpected features that will be helpful in the engineering additional versions of lipopeptide amphiphiles.

  9. Organic and detergent degradation in combined O3/UF for domestic laundry wastewater reclamation.

    PubMed

    Seo, G T; Lee, T S; Kim, J T; Yoon, C H; Park, H G; Hong, S C

    2004-01-01

    This paper focuses on the evaluation of organic and detergent degradation in a combined Ozone/UF system for domestic laundry wastewater reclamation. Formation of by-product was investigated by GC/MS for the reclaimed water. Ozone was injected into the raw wastewater in a 10 L contact tank and the wastewater was circulated through the membrane module for inner pressurized cross-flow filtration. The concentrate was returned back to the contact tank. The membrane used in this experiment was hollow fiber polysulfone UF membrane with MWCO 10,000. It has an effective filtration area of 0.06 m2. The experiment was carried out with intermittent ozone injection, 5 min injection and 10 min idling. Ozone was dosed at the concentration of 1.5 mg/L. The flux of the UF could be maintained at 0.24 m/d under filtration pressure 40-45 kPa and water temperature, 20-22 degrees C. The organic removal efficiency by the system was 90% in terms of COD. Ozone was considerably effective to degrade organics in the wastewater. Molecular weight of organics in the raw waste was mostly greater than 10,000 (72% of 950 mgCOD/L). However 86% of effluent COD (94-100 mg/L) was composed of organics smaller than MWCO 500 by ozone injection. No harmful by-products by ozone contact were detected from the analysis of treated water using GC/MS. It was identified that residual organics in the treated water were 1,1'-Oxybisbenzene, Octadecanoic acid, Squalene and Benzenmethanol, etc., which were additives contained originally in the detergent. Consequently the reclaimed water quality could be estimated safe enough to recycle for the rinsing cycle in a washing machine.

  10. Proteomic Analysis of Lipid Raft-Like Detergent-Resistant Membranes of Lens Fiber Cells

    PubMed Central

    Wang, Zhen; Schey, Kevin L.

    2015-01-01

    Purpose Plasma membranes of lens fiber cells have high levels of long-chain saturated fatty acids, cholesterol, and sphingolipids—key components of lipid rafts. Thus, lipid rafts are expected to constitute a significant portion of fiber cell membranes and play important roles in lens biology. The purpose of this study was to characterize the lens lipid raft proteome. Methods Quantitative proteomics, both label-free and iTRAQ methods, were used to characterize lens fiber cell lipid raft proteins. Detergent-resistant, lipid raft membrane (DRM) fractions were isolated by sucrose gradient centrifugation. To confirm protein localization to lipid rafts, protein sensitivity to cholesterol removal by methyl-β-cyclodextrin was quantified by iTRAQ analysis. Results A total of 506 proteins were identified in raft-like detergent-resistant membranes. Proteins identified support important functions of raft domains in fiber cells, including trafficking, signal transduction, and cytoskeletal organization. In cholesterol-sensitivity studies, 200 proteins were quantified and 71 proteins were strongly affected by cholesterol removal. Lipid raft markers flotillin-1 and flotillin-2 and a significant fraction of AQP0, MP20, and AQP5 were found in the DRM fraction and were highly sensitive to cholesterol removal. Connexins 46 and 50 were more abundant in nonraft fractions, but a small fraction of each was found in the DRM fraction and was strongly affected by cholesterol removal. Quantification of modified AQP0 confirmed that fatty acylation targeted this protein to membrane raft domains. Conclusions These data represent the first comprehensive profile of the lipid raft proteome of lens fiber cells and provide information on membrane protein organization in these cells. PMID:26747763

  11. Towards the Knittability of Graphene Oxide Fibres.

    PubMed

    Seyedin, Shayan; Romano, Mark S; Minett, Andrew I; Razal, Joselito M

    2015-10-13

    Recent developments in graphene oxide fibre (GO) processing include exciting demonstrations of hand woven textile structures. However, it is uncertain whether the fibres produced can meet the processing requirements of conventional textile manufacturing. This work reports for the first time the production of highly flexible and tough GO fibres that can be knitted using textile machinery. The GO fibres are made by using a dry-jet wet-spinning method, which allows drawing of the spinning solution (the GO dispersion) in several stages of the fibre spinning process. The coagulation composition and spinning conditions are evaluated in detail, which led to the production of densely packed fibres with near-circular cross-sections and highly ordered GO domains. The results are knittable GO fibres with Young's modulus of ~7.9 GPa, tensile strength of ~135.8 MPa, breaking strain of ~5.9%, and toughness of ~5.7 MJ m(-3). The combination of suitable spinning method, coagulation composition, and spinning conditions led to GO fibres with remarkable toughness; the key factor in their successful knitting. This work highlights important progress in realising the full potential of GO fibres as a new class of textile.

  12. Towards the Knittability of Graphene Oxide Fibres

    PubMed Central

    Seyedin, Shayan; Romano, Mark S.; Minett, Andrew I.; Razal, Joselito M.

    2015-01-01

    Recent developments in graphene oxide fibre (GO) processing include exciting demonstrations of hand woven textile structures. However, it is uncertain whether the fibres produced can meet the processing requirements of conventional textile manufacturing. This work reports for the first time the production of highly flexible and tough GO fibres that can be knitted using textile machinery. The GO fibres are made by using a dry-jet wet-spinning method, which allows drawing of the spinning solution (the GO dispersion) in several stages of the fibre spinning process. The coagulation composition and spinning conditions are evaluated in detail, which led to the production of densely packed fibres with near-circular cross-sections and highly ordered GO domains. The results are knittable GO fibres with Young’s modulus of ~7.9 GPa, tensile strength of ~135.8 MPa, breaking strain of ~5.9%, and toughness of ~5.7 MJ m−3. The combination of suitable spinning method, coagulation composition, and spinning conditions led to GO fibres with remarkable toughness; the key factor in their successful knitting. This work highlights important progress in realising the full potential of GO fibres as a new class of textile. PMID:26459866

  13. Local dynamics for fibred holomorphic transformations

    NASA Astrophysics Data System (ADS)

    Ponce, Mario

    2007-12-01

    Fibred holomorphic dynamics are skew-product transformations F(θ, z) = (θ + α, fθ(z)) over an irrational rotation, such that fθ is holomorphic for every θ. In this paper we study such a dynamics in a neighbourhood of an invariant curve. We obtain some results analogous to the results in the non-fibred case. In particular, we prove a fibred version of the folklore result stating that Lyapounov stability is equivalent to linearization around a fixed point. We also obtain a fibred version of the Pérez-Marco continua.

  14. Thermal response of tellurite glass optical fibre

    NASA Astrophysics Data System (ADS)

    Li, Hongxia; Lousteau, Joris; Bookey, Henry T.; MacPherson, William N.; Barton, James S.; Kar, Ajoy K.; Jha, Animesh

    2007-07-01

    We have measured the phase sensitivity to temperature of a fibre Fabry-Perot (FFP) formed by splicing multimode tellurite (TeO II) glass fibre to singlemode silica fibre. The free spectral ranges of two FFPs of different lengths were consistent with the values expected from independent determinations of the core refractive indices. The phase sensitivity was 89.3 +/- 0.3rad m -1 K -1 at a central wavelength of 1536 nm, compared with 99.8 rad m -1 K -1 for silica fibre.

  15. Towards the Knittability of Graphene Oxide Fibres

    NASA Astrophysics Data System (ADS)

    Seyedin, Shayan; Romano, Mark S.; Minett, Andrew I.; Razal, Joselito M.

    2015-10-01

    Recent developments in graphene oxide fibre (GO) processing include exciting demonstrations of hand woven textile structures. However, it is uncertain whether the fibres produced can meet the processing requirements of conventional textile manufacturing. This work reports for the first time the production of highly flexible and tough GO fibres that can be knitted using textile machinery. The GO fibres are made by using a dry-jet wet-spinning method, which allows drawing of the spinning solution (the GO dispersion) in several stages of the fibre spinning process. The coagulation composition and spinning conditions are evaluated in detail, which led to the production of densely packed fibres with near-circular cross-sections and highly ordered GO domains. The results are knittable GO fibres with Young’s modulus of ~7.9 GPa, tensile strength of ~135.8 MPa, breaking strain of ~5.9%, and toughness of ~5.7 MJ m-3. The combination of suitable spinning method, coagulation composition, and spinning conditions led to GO fibres with remarkable toughness; the key factor in their successful knitting. This work highlights important progress in realising the full potential of GO fibres as a new class of textile.

  16. A compact polymer optical fibre ultrasound detector

    NASA Astrophysics Data System (ADS)

    Broadway, Christian; Gallego, Daniel; Pospori, Andreas; Zubel, Michal; Webb, David J.; Sugden, Kate; Carpintero, Guillermo; Lamela, Horacio

    2016-03-01

    Polymer optical fibre (POF) is a relatively new and novel technology that presents an innovative approach for ultrasonic endoscopic applications. Currently, piezo electric transducers are the typical detectors of choice, albeit possessing a limited bandwidth due to their resonant nature and a sensitivity that decreases proportionally to their size. Optical fibres provide immunity from electromagnetic interference and POF in particular boasts more suitable physical characteristics than silica optical fibre. The most important of these are lower acoustic impedance, a reduced Young's Modulus and a higher acoustic sensitivity than single-mode silica fibre at both 1 MHz and 10 MHz. POF therefore offers an interesting alternative to existing technology. Intrinsic fibre structures such as Bragg gratings and Fabry-Perot cavities may be inscribed into the fibre core using UV lasers. These gratings are a modulation of the refractive index of the fibre core and provide the advantages of high reflectivity, customisable bandwidth and point detection. We present a compact in fibre ultrasonic point detector based upon a POF Bragg grating (POFBG) sensor. We demonstrate that the detector is capable of leaving a laboratory environment by using connectorised fibre sensors and make a case for endoscopic ultrasonic detection through use of a mounting structure that better mimics the environment of an endoscopic probe. We measure the effects of water immersion upon POFBGs and analyse the ultrasonic response for 1, 5 and 10 MHz.

  17. Efficacy of adding detergents to sanitizer solutions for inactivation of Escherichia coli O157:H7 on Romaine lettuce.

    PubMed

    Keskinen, Lindsey A; Annous, Bassam A

    2011-06-30

    Numerous Escherichia coli O157:H7 outbreaks have been linked to consumption of fresh lettuce. The development of effective and easily implemented wash treatment could reduce such incidents. The purpose of this study was to evaluate the addition of food-grade detergents to sanitizer solutions for inactivation of E. coli O157:H7 on Romaine lettuce. Freshly-cut leaves of Romaine lettuce were dip-inoculated to achieve a final cell concentration of 7.8±0.2 log CFU/g, air-dried for 2h, and stored overnight at 4 °C. Leaves were then washed for 2 min in an experimental short chain fatty acid formulation (SCFA) or in one of the following solutions with or without 0.2% dodecylbenzenesulfonic acid or 0.2% sodium 2-ethyl hexyl sulfate: 1) deionized water; 2) 100 ppm chlorine dioxide; 3) 100 ppm chlorine; and 4) 200 ppm chlorine. Following wash treatment, samples were blended in neutralizing buffer (1:3) and surface plated on the selective media CT-SMAC. The efficacy of wash treatments, with or without the detergents, in inactivating E. coli O157:H7 cells on lettuce leaves were not significantly different. The most effective wash solution was SCFA, which was capable of reducing E. coli O157:H7 populations by more than 5 log CFU/g. The rest of the wash treatments resulted in a population reduction of less than 1 log CFU/g. The effectiveness of SCFA surpasses that of other sanitizer treatments tested in this study and requires further research to optimize treatments to preserve lettuce quality. Conventional detergents did not enhance the efficacy of any of the wash treatments tested during this study. PMID:21529976

  18. Efficacy of adding detergents to sanitizer solutions for inactivation of Escherichia coli O157:H7 on Romaine lettuce.

    PubMed

    Keskinen, Lindsey A; Annous, Bassam A

    2011-06-30

    Numerous Escherichia coli O157:H7 outbreaks have been linked to consumption of fresh lettuce. The development of effective and easily implemented wash treatment could reduce such incidents. The purpose of this study was to evaluate the addition of food-grade detergents to sanitizer solutions for inactivation of E. coli O157:H7 on Romaine lettuce. Freshly-cut leaves of Romaine lettuce were dip-inoculated to achieve a final cell concentration of 7.8±0.2 log CFU/g, air-dried for 2h, and stored overnight at 4 °C. Leaves were then washed for 2 min in an experimental short chain fatty acid formulation (SCFA) or in one of the following solutions with or without 0.2% dodecylbenzenesulfonic acid or 0.2% sodium 2-ethyl hexyl sulfate: 1) deionized water; 2) 100 ppm chlorine dioxide; 3) 100 ppm chlorine; and 4) 200 ppm chlorine. Following wash treatment, samples were blended in neutralizing buffer (1:3) and surface plated on the selective media CT-SMAC. The efficacy of wash treatments, with or without the detergents, in inactivating E. coli O157:H7 cells on lettuce leaves were not significantly different. The most effective wash solution was SCFA, which was capable of reducing E. coli O157:H7 populations by more than 5 log CFU/g. The rest of the wash treatments resulted in a population reduction of less than 1 log CFU/g. The effectiveness of SCFA surpasses that of other sanitizer treatments tested in this study and requires further research to optimize treatments to preserve lettuce quality. Conventional detergents did not enhance the efficacy of any of the wash treatments tested during this study.

  19. A validation of the fibre orientation and fibre length attrition prediction for long fibre-reinforced thermoplastics

    SciTech Connect

    Hopmann, Ch.; Weber, M.; Haag, J. van; Schöngart, M.

    2015-05-22

    To improve the mechanical performance of polymeric parts, fibre reinforcement has established in industrial applications during the last decades. Next to the widely used Short Fibre-reinforced Thermoplastics (SFT) the use of Long Fibre-reinforced Thermoplastics (LFT) is increasingly growing. Especially for non-polar polymeric matrices like polypropylene (PP), longer fibres can significantly improve the mechanical performance. As with every kind of discontinuous fibre reinforcement the fibre orientations (FO) show a high impact on the mechanical properties. On the contrary to SFT where the local fibre length distribution (FLD) can be often neglected, for LFT the FLD show a high impact on the material’s properties and has to be taken into account in equal measure to the FOD. Recently numerical models are available in commercial filling simulation software and allow predicting both the local FOD and FLD in LFT parts. The aim of this paper is to compare i.) the FOD results and ii) the FLD results from available orientation- and fibre length attrition-models to those obtained from experimental data. The investigations are conducted by the use of different injection moulded specimens made from long glass fibre reinforced PP. In order to determine the FOD, selected part sections are examined by means of Computed Tomographic (CT) analyses. The fully three dimensional measurement of the FOD is then performed by digital image processing using grey scale correlation. The FLD results are also obtained by using digital image processing after a thermal pyrolytic separation of the polymeric matrix from the fibres. Further the FOD and the FLD are predicted by using a reduced strain closure (RSC) as well as an anisotropic rotary diffusion - reduced strain closure model (ARD-RSC) and Phelps-Tucker fibre length attrition model implemented in the commercial filling software Moldflow, Autodesk Inc., San Rafael, CA, USA.

  20. A validation of the fibre orientation and fibre length attrition prediction for long fibre-reinforced thermoplastics

    NASA Astrophysics Data System (ADS)

    Hopmann, Ch.; Weber, M.; van Haag, J.; Schöngart, M.

    2015-05-01

    To improve the mechanical performance of polymeric parts, fibre reinforcement has established in industrial applications during the last decades. Next to the widely used Short Fibre-reinforced Thermoplastics (SFT) the use of Long Fibre-reinforced Thermoplastics (LFT) is increasingly growing. Especially for non-polar polymeric matrices like polypropylene (PP), longer fibres can significantly improve the mechanical performance. As with every kind of discontinuous fibre reinforcement the fibre orientations (FO) show a high impact on the mechanical properties. On the contrary to SFT where the local fibre length distribution (FLD) can be often neglected, for LFT the FLD show a high impact on the material's properties and has to be taken into account in equal measure to the FOD. Recently numerical models are available in commercial filling simulation software and allow predicting both the local FOD and FLD in LFT parts. The aim of this paper is to compare i.) the FOD results and ii) the FLD results from available orientation- and fibre length attrition-models to those obtained from experimental data. The investigations are conducted by the use of different injection moulded specimens made from long glass fibre reinforced PP. In order to determine the FOD, selected part sections are examined by means of Computed Tomographic (CT) analyses. The fully three dimensional measurement of the FOD is then performed by digital image processing using grey scale correlation. The FLD results are also obtained by using digital image processing after a thermal pyrolytic separation of the polymeric matrix from the fibres. Further the FOD and the FLD are predicted by using a reduced strain closure (RSC) as well as an anisotropic rotary diffusion - reduced strain closure model (ARD-RSC) and Phelps-Tucker fibre length attrition model implemented in the commercial filling software Moldflow, Autodesk Inc., San Rafael, CA, USA.

  1. Structure and Sialyllactose Binding of the Carboxy-Terminal Head Domain of the Fibre from a Siadenovirus, Turkey Adenovirus 3.

    PubMed

    Singh, Abhimanyu K; Berbís, M Álvaro; Ballmann, Mónika Z; Kilcoyne, Michelle; Menéndez, Margarita; Nguyen, Thanh H; Joshi, Lokesh; Cañada, F Javier; Jiménez-Barbero, Jesús; Benkő, Mária; Harrach, Balázs; van Raaij, Mark J

    2015-01-01

    The virulent form of turkey adenovirus 3 (TAdV-3), also known as turkey hemorrhagic enteritis virus (THEV), is an economically important poultry pathogen, while the avirulent form is used as a vaccine. TAdV-3 belongs to the genus Siadenovirus. The carboxy-terminal region of its fibre does not have significant sequence similarity to any other adenovirus fibre heads of known structure. Two amino acid sequence differences between virulent and avirulent TAdV-3 map on the fibre head: where virulent TAdV-3 contains Ile354 and Thr376, avirulent TAdV-3 contains Met354 and Met376. We determined the crystal structures of the trimeric virulent and avirulent TAdV-3 fibre head domains at 2.2 Å resolution. Each monomer contains a beta-sandwich, which, surprisingly, resembles reovirus fibre head more than other adenovirus fibres, although the ABCJ-GHID topology is conserved in all. A beta-hairpin insertion in the C-strand of each trimer subunit embraces its neighbouring monomer. The avirulent and virulent TAdV-3 fibre heads are identical apart from the exact orientation of the beta-hairpin insertion. In vitro, sialyllactose was identified as a ligand by glycan microarray analysis, nuclear magnetic resonance spectroscopy, and crystallography. Its dissociation constant was measured to be in the mM range by isothermal titration calorimetry. The ligand binds to the side of the fibre head, involving amino acids Glu392, Thr419, Val420, Lys421, Asn422, and Gly423 binding to the sialic acid group. It binds slightly more strongly to the avirulent form. We propose that, in vivo, the TAdV-3 fibre may bind a sialic acid-containing cell surface component.

  2. Structure and Sialyllactose Binding of the Carboxy-Terminal Head Domain of the Fibre from a Siadenovirus, Turkey Adenovirus 3

    PubMed Central

    Singh, Abhimanyu K.; Berbís, M. Álvaro; Ballmann, Mónika Z.; Kilcoyne, Michelle; Menéndez, Margarita; Nguyen, Thanh H.; Joshi, Lokesh; Cañada, F. Javier; Jiménez-Barbero, Jesús; Benkő, Mária; Harrach, Balázs; van Raaij, Mark J.

    2015-01-01

    The virulent form of turkey adenovirus 3 (TAdV-3), also known as turkey hemorrhagic enteritis virus (THEV), is an economically important poultry pathogen, while the avirulent form is used as a vaccine. TAdV-3 belongs to the genus Siadenovirus. The carboxy-terminal region of its fibre does not have significant sequence similarity to any other adenovirus fibre heads of known structure. Two amino acid sequence differences between virulent and avirulent TAdV-3 map on the fibre head: where virulent TAdV-3 contains Ile354 and Thr376, avirulent TAdV-3 contains Met354 and Met376. We determined the crystal structures of the trimeric virulent and avirulent TAdV-3 fibre head domains at 2.2 Å resolution. Each monomer contains a beta-sandwich, which, surprisingly, resembles reovirus fibre head more than other adenovirus fibres, although the ABCJ-GHID topology is conserved in all. A beta-hairpin insertion in the C-strand of each trimer subunit embraces its neighbouring monomer. The avirulent and virulent TAdV-3 fibre heads are identical apart from the exact orientation of the beta-hairpin insertion. In vitro, sialyllactose was identified as a ligand by glycan microarray analysis, nuclear magnetic resonance spectroscopy, and crystallography. Its dissociation constant was measured to be in the mM range by isothermal titration calorimetry. The ligand binds to the side of the fibre head, involving amino acids Glu392, Thr419, Val420, Lys421, Asn422, and Gly423 binding to the sialic acid group. It binds slightly more strongly to the avirulent form. We propose that, in vivo, the TAdV-3 fibre may bind a sialic acid-containing cell surface component. PMID:26418008

  3. Structure and Sialyllactose Binding of the Carboxy-Terminal Head Domain of the Fibre from a Siadenovirus, Turkey Adenovirus 3.

    PubMed

    Singh, Abhimanyu K; Berbís, M Álvaro; Ballmann, Mónika Z; Kilcoyne, Michelle; Menéndez, Margarita; Nguyen, Thanh H; Joshi, Lokesh; Cañada, F Javier; Jiménez-Barbero, Jesús; Benkő, Mária; Harrach, Balázs; van Raaij, Mark J

    2015-01-01

    The virulent form of turkey adenovirus 3 (TAdV-3), also known as turkey hemorrhagic enteritis virus (THEV), is an economically important poultry pathogen, while the avirulent form is used as a vaccine. TAdV-3 belongs to the genus Siadenovirus. The carboxy-terminal region of its fibre does not have significant sequence similarity to any other adenovirus fibre heads of known structure. Two amino acid sequence differences between virulent and avirulent TAdV-3 map on the fibre head: where virulent TAdV-3 contains Ile354 and Thr376, avirulent TAdV-3 contains Met354 and Met376. We determined the crystal structures of the trimeric virulent and avirulent TAdV-3 fibre head domains at 2.2 Å resolution. Each monomer contains a beta-sandwich, which, surprisingly, resembles reovirus fibre head more than other adenovirus fibres, although the ABCJ-GHID topology is conserved in all. A beta-hairpin insertion in the C-strand of each trimer subunit embraces its neighbouring monomer. The avirulent and virulent TAdV-3 fibre heads are identical apart from the exact orientation of the beta-hairpin insertion. In vitro, sialyllactose was identified as a ligand by glycan microarray analysis, nuclear magnetic resonance spectroscopy, and crystallography. Its dissociation constant was measured to be in the mM range by isothermal titration calorimetry. The ligand binds to the side of the fibre head, involving amino acids Glu392, Thr419, Val420, Lys421, Asn422, and Gly423 binding to the sialic acid group. It binds slightly more strongly to the avirulent form. We propose that, in vivo, the TAdV-3 fibre may bind a sialic acid-containing cell surface component. PMID:26418008

  4. Membrane protein stability can be compromised by detergent interactions with the extramembranous soluble domains.

    PubMed

    Yang, Zhengrong; Wang, Chi; Zhou, Qingxian; An, Jianli; Hildebrandt, Ellen; Aleksandrov, Luba A; Kappes, John C; DeLucas, Lawrence J; Riordan, John R; Urbatsch, Ina L; Hunt, John F; Brouillette, Christie G

    2014-06-01

    Detergent interaction with extramembranous soluble domains (ESDs) is not commonly considered an important determinant of integral membrane protein (IMP) behavior during purification and crystallization, even though ESDs contribute to the stability of many IMPs. Here we demonstrate that some generally nondenaturing detergents critically destabilize a model ESD, the first nucleotide-binding domain (NBD1) from the human cystic fibrosis transmembrane conductance regulator (CFTR), a model IMP. Notably, the detergents show equivalent trends in their influence on the stability of isolated NBD1 and full-length CFTR. We used differential scanning calorimetry (DSC) and circular dichroism (CD) spectroscopy to monitor changes in NBD1 stability and secondary structure, respectively, during titration with a series of detergents. Their effective harshness in these assays mirrors that widely accepted for their interaction with IMPs, i.e., anionic > zwitterionic > nonionic. It is noteworthy that including lipids or nonionic detergents is shown to mitigate detergent harshness, as will limiting contact time. We infer three thermodynamic mechanisms from the observed thermal destabilization by monomer or micelle: (i) binding to the unfolded state with no change in the native structure (all detergent classes); (ii) native state binding that alters thermodynamic properties and perhaps conformation (nonionic detergents); and (iii) detergent binding that directly leads to denaturation of the native state (anionic and zwitterionic). These results demonstrate that the accepted model for the harshness of detergents applies to their interaction with an ESD. It is concluded that destabilization of extramembranous soluble domains by specific detergents will influence the stability of some IMPs during purification.

  5. Deuterated detergents for structural and functional studies of membrane proteins: Properties, chemical synthesis and applications.

    PubMed

    Hiruma-Shimizu, Kazumi; Shimizu, Hiroki; Thompson, Gary S; Kalverda, Arnout P; Patching, Simon G

    2015-01-01

    Detergents are amphiphilic compounds that have crucial roles in the extraction, purification and stabilization of integral membrane proteins and in experimental studies of their structure and function. One technique that is highly dependent on detergents for solubilization of membrane proteins is solution-state NMR spectroscopy, where detergent micelles often serve as the best membrane mimetic for achieving particle sizes that tumble fast enough to produce high-resolution and high-sensitivity spectra, although not necessarily the best mimetic for a biomembrane. For achieving the best quality NMR spectra, detergents with partial or complete deuteration can be used, which eliminate interfering proton signals coming from the detergent itself and also eliminate potential proton relaxation pathways and strong dipole-dipole interactions that contribute line broadening effects. Deuterated detergents have also been used to solubilize membrane proteins for other experimental techniques including small angle neutron scattering and single-crystal neutron diffraction and for studying membrane proteins immobilized on gold electrodes. This is a review of the properties, chemical synthesis and applications of detergents that are currently commercially available and/or that have been synthesized with partial or complete deuteration. Specifically, the detergents are sodium dodecyl sulphate (SDS), lauryldimethylamine-oxide (LDAO), n-octyl-β-D-glucoside (β-OG), n-dodecyl-β-D-maltoside (DDM) and fos-cholines including dodecylphosphocholine (DPC). The review also considers effects of deuteration, detergent screening and guidelines for detergent selection. Although deuterated detergents are relatively expensive and not always commercially available due to challenges associated with their chemical synthesis, they will continue to play important roles in structural and functional studies of membrane proteins, especially using solution-state NMR.

  6. Membrane protein stability can be compromised by detergent interactions with the extramembranous soluble domains

    PubMed Central

    Yang, Zhengrong; Wang, Chi; Zhou, Qingxian; An, Jianli; Hildebrandt, Ellen; Aleksandrov, Luba A; Kappes, John C; DeLucas, Lawrence J; Riordan, John R; Urbatsch, Ina L; Hunt, John F; Brouillette, Christie G

    2014-01-01

    Detergent interaction with extramembranous soluble domains (ESDs) is not commonly considered an important determinant of integral membrane protein (IMP) behavior during purification and crystallization, even though ESDs contribute to the stability of many IMPs. Here we demonstrate that some generally nondenaturing detergents critically destabilize a model ESD, the first nucleotide-binding domain (NBD1) from the human cystic fibrosis transmembrane conductance regulator (CFTR), a model IMP. Notably, the detergents show equivalent trends in their influence on the stability of isolated NBD1 and full-length CFTR. We used differential scanning calorimetry (DSC) and circular dichroism (CD) spectroscopy to monitor changes in NBD1 stability and secondary structure, respectively, during titration with a series of detergents. Their effective harshness in these assays mirrors that widely accepted for their interaction with IMPs, i.e., anionic > zwitterionic > nonionic. It is noteworthy that including lipids or nonionic detergents is shown to mitigate detergent harshness, as will limiting contact time. We infer three thermodynamic mechanisms from the observed thermal destabilization by monomer or micelle: (i) binding to the unfolded state with no change in the native structure (all detergent classes); (ii) native state binding that alters thermodynamic properties and perhaps conformation (nonionic detergents); and (iii) detergent binding that directly leads to denaturation of the native state (anionic and zwitterionic). These results demonstrate that the accepted model for the harshness of detergents applies to their interaction with an ESD. It is concluded that destabilization of extramembranous soluble domains by specific detergents will influence the stability of some IMPs during purification. PMID:24652590

  7. Surface treated polypropylene (PP) fibres for reinforced concrete

    SciTech Connect

    López-Buendía, Angel M.; Romero-Sánchez, María Dolores; Climent, Verónica

    2013-12-15

    Surface treatments on a polypropylene (PP) fibre have contributed to the improvement of fibre/concrete adhesion in fibre-reinforced concrete. The treatments to the PP fibre were characterized by contact angle measurements, ATR-IR and XPS to analyse chemical alterations. The surface topography and fibre/concrete interaction were analysed by several microscopic techniques, namely optical petrographic, and scanning electron microscopy. Treatment modified the surface chemistry and topography of the fibre by introducing sodium moieties and created additional fibre surface roughness. Modifications in the fibre surface led to an increase in the adhesion properties between the treated fibres and concrete and an improvement in the mechanical properties of the fibre-reinforced concrete composite as compared to the concrete containing untreated PP fibres. Compatibility with the concrete and increased roughness and mineral surface was also improved by nucleated portlandite and ettringite mineral association anchored on the alkaline PP fibre surface, which is induced during treatment.

  8. Equilibrium studies of copper ion adsorption onto palm kernel fibre.

    PubMed

    Ofomaja, Augustine E

    2010-07-01

    The equilibrium sorption of copper ions from aqueous solution using a new adsorbent, palm kernel fibre, has been studied. Palm kernel fibre is obtained in large amounts as a waste product of palm oil production. Batch equilibrium studies were carried out and system variables such as solution pH, sorbent dose, and sorption temperature were varied. The equilibrium sorption data was then analyzed using the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherms. The fit of these isotherm models to the equilibrium sorption data was determined, using the linear coefficient of determination, r(2), and the non-linear Chi-square, chi(2) error analysis. The results revealed that sorption was pH dependent and increased with increasing solution pH above the pH(PZC) of the palm kernel fibre with an optimum dose of 10g/dm(3). The equilibrium data were found to fit the Langmuir isotherm model best, with a monolayer capacity of 3.17 x 10(-4)mol/g at 339K. The sorption equilibrium constant, K(a), increased with increasing temperature, indicating that bond strength between sorbate and sorbent increased with temperature and sorption was endothermic. This was confirmed by the increase in the values of the Temkin isotherm constant, B(1), with increasing temperature. The Dubinin-Radushkevich (D-R) isotherm parameter, free energy, E, was in the range of 15.7-16.7kJ/mol suggesting that the sorption mechanism was ion exchange. Desorption studies showed that a high percentage of the copper was desorbed from the adsorbent using acid solutions (HCl, HNO(3) and CH(3)COOH) and the desorption percentage increased with acid concentration. The thermodynamics of the copper ions/palm kernel fibre system indicate that the process is spontaneous and endothermic. PMID:20346574

  9. Equilibrium studies of copper ion adsorption onto palm kernel fibre.

    PubMed

    Ofomaja, Augustine E

    2010-07-01

    The equilibrium sorption of copper ions from aqueous solution using a new adsorbent, palm kernel fibre, has been studied. Palm kernel fibre is obtained in large amounts as a waste product of palm oil production. Batch equilibrium studies were carried out and system variables such as solution pH, sorbent dose, and sorption temperature were varied. The equilibrium sorption data was then analyzed using the Langmuir, Freundlich, Dubinin-Radushkevich (D-R) and Temkin isotherms. The fit of these isotherm models to the equilibrium sorption data was determined, using the linear coefficient of determination, r(2), and the non-linear Chi-square, chi(2) error analysis. The results revealed that sorption was pH dependent and increased with increasing solution pH above the pH(PZC) of the palm kernel fibre with an optimum dose of 10g/dm(3). The equilibrium data were found to fit the Langmuir isotherm model best, with a monolayer capacity of 3.17 x 10(-4)mol/g at 339K. The sorption equilibrium constant, K(a), increased with increasing temperature, indicating that bond strength between sorbate and sorbent increased with temperature and sorption was endothermic. This was confirmed by the increase in the values of the Temkin isotherm constant, B(1), with increasing temperature. The Dubinin-Radushkevich (D-R) isotherm parameter, free energy, E, was in the range of 15.7-16.7kJ/mol suggesting that the sorption mechanism was ion exchange. Desorption studies showed that a high percentage of the copper was desorbed from the adsorbent using acid solutions (HCl, HNO(3) and CH(3)COOH) and the desorption percentage increased with acid concentration. The thermodynamics of the copper ions/palm kernel fibre system indicate that the process is spontaneous and endothermic.

  10. Simulation of complex phenomena in optical fibres

    NASA Astrophysics Data System (ADS)

    Allington-Smith, Jeremy; Murray, Graham; Lemke, Ulrike

    2012-12-01

    Optical fibres are essential for many types of highly multiplexed and precision spectroscopy. The success of the new generation of multifibre instruments under construction to investigate fundamental problems in cosmology, such as the nature of dark energy, requires accurate modellization of the fibre system to achieve their signal-to-noise ratio (SNR) goals. Despite their simple construction, fibres exhibit unexpected behaviour including non-conservation of etendue (focal ratio degradation, FRD) and modal noise. Furthermore, new fibre geometries (non-circular or tapered) have become available to improve the scrambling properties that, together with modal noise, limit the achievable SNR in precision spectroscopy. These issues have often been addressed by extensive tests on candidate fibres and their terminations, but these are difficult and time-consuming. Modelling by ray tracing and wave analysis is possible with commercial software packages, but these do not address the more complex features, in particular FRD. We use a phase-tracking ray-tracing method to provide a practical description of FRD derived from our previous experimental work on circular fibres and apply it to non-standard fibres. This allows the relationship between scrambling and FRD to be quantified for the first time. We find that scrambling primarily affects the shape of the near-field pattern but has negligible effect on the barycentre. FRD helps to homogenize the near-field pattern but does not make it completely uniform. Fibres with polygonal cross-section improve scrambling without amplifying the FRD. Elliptical fibres, in conjunction with tapering, may offer an efficient means of image slicing to improve the product of resolving power and throughput, but the result is sensitive to the details of illumination. We also investigated the performance of fibres close to the limiting numerical aperture since this may affect the uniformity of the SNR for some prime focus fibre instrumentation.

  11. Polarisation effects in twin-core fibre: Application for mode locking in a fibre laser

    SciTech Connect

    Lobach, I A; Kablukov, S I; Podivilov, Evgenii V; Babin, Sergei A; Apolonski, A A

    2012-09-30

    We report the first measurements of the longitudinal power distribution in a twin-core optical fibre at different input light polarisations. Experimental evidence is presented that, because of the difference in birefringence between the cores, the power in them depends on which core the beam is launched into. Experimental data are interpreted in terms of a modified polarisation model for mode coupling in twin-core fibres which takes into account the birefringence of the cores. In addition, we demonstrate for the first time the use of the polarisation properties of a twincore fibre for mode locking in a fibre laser. (optical fibres, lasers and amplifiers. properties and applications)

  12. Synthesis and Properties of Dodecyl Trehaloside Detergents for Membrane Protein Studies

    PubMed Central

    Tao, Houchao; Fu, Yu; Thompson, Aaron; Lee, Sung Chang; Mahoney, Nicholas; Stevens, Raymond C.; Zhang, Qinghai

    2012-01-01

    Sugar-based detergents, mostly derived from maltose or glucose, prevail in the extraction, solubilization, stabilization and crystallization of membrane proteins. Inspired by the broad use of trehalose for protecting biological macromolecules and lipid bilayer structures, we synthesized new trehaloside detergents for potential applications in membrane protein research. We devised an efficient synthesis of four dodecyl trehalosides, each with the 12-carboned alkyl chain attached to different hydroxyl groups of trehalose, thus presenting a structurally diverse but related family of detergents. The detergent physical properties, including solubility, hydrophobicity, critical micelle concentration (CMC) and size of micelles, were evaluated and compared with the most popular maltoside analog, β- D-dodecylmaltoside (DDM), which varied from each other due to distinct molecular geometries and possible polar group interactions in resulting micelles. Crystals of 2-dodecyl trehaloside (2-DDTre) were also obtained in methanol, and the crystal packing revealed multiple H-bonded interactions among adjacent trehalose groups. The few trehaloside detergents were tested for the solubilization and stabilization of the nociceptin/orphanin FQ peptide receptor (ORL1) and MsbA, which belong to the G-protein coupled receptor (GPCR) and ATP-binding cassette transporter families, respectively. Our results demonstrated the utility of trehaloside detergents as membrane protein solubilization reagents with the optimal detergents being protein dependent. Continuing development and investigations of trehaloside detergents are attractive given their interesting and unique chemical-physical properties and potential interactions with membrane lipids. PMID:22780816

  13. Detergent-resistant globotriaosyl ceramide may define verotoxin/glomeruli-restricted hemolytic uremic syndrome pathology.

    PubMed

    Khan, Fahima; Proulx, François; Lingwood, Clifford A

    2009-06-01

    Verotoxin binding to its receptor, globotriaosyl ceramide(Gb(3)) mediates the glomerular pathology of hemolytic uremic syndrome, but Gb(3) is expressed in both tubular and glomerular cells. Gb(3) within detergent-resistant membranes, an index of glycolipid-cholesterol enriched lipid rafts, is required for in vitro cytotoxicity. We found that verotoxin 1 and 2 binding to human adult renal glomeruli is detergent resistant, whereas the strong verotoxin binding to renal tubules is detergent sensitive. Verotoxin binding to pediatric glomeruli was detergent resistant but binding to adult glomeruli was enhanced, remarkably for some samples, by detergent extraction. Detergent-sensitive glomerular components may provide age-related protection against verotoxin glomerular binding. Mouse glomeruli remained verotoxin unreactive after detergent extraction, whereas tubular binding was lost. Cholesterol extraction induced strong verotoxin binding in poorly reactive adult glomeruli, suggesting cholesterol can mask Gb(3) in glomerular lipid rafts. Binding of the human immunodeficiency virus (HIV) adhesin, gp120 (another Gb(3) ligand) was detergent sensitive, tubule-restricted, and inhibited by verotoxin B subunit pretreatment, and may relate to HIV nephropathy. Our study shows that differential membrane Gb(3) organization in glomeruli and tubules provides a basis for the age- and glomerular-restricted pathology of hemolytic uremic syndrome.

  14. Properties of Zeolite A Obtained from Powdered Laundry Detergent: An Undergraduate Experiment.

    ERIC Educational Resources Information Center

    Smoot, Alison L.; Lindquist, David A.

    1997-01-01

    Presents experiments that introduce students to the myriad properties of zeolites using the sodium form of zeolite A (Na-A) from laundry detergent. Experiments include extracting Na-A from detergent, water softening properties, desiccant properties, ion-exchange properties, and Zeolite HA as a dehydration catalyst. (JRH)

  15. The effects of intake valve detergent structure on combustion chamber deposits (CCD)

    SciTech Connect

    Kelemen, S.R.; Maxey, C.T.

    1995-12-31

    Combustion chamber deposits (CCD) have been heavily researched in the past with regard to Octane Requirement Increase (ORI). New concerns about their role in combustion chamber deposit interference (CCDI) and their potential contribution to exhaust emissions have reinforced interest in defining the underlying factors that contribute to CCD. In this study, intake valve detergents were evaluated in the absence of any fluidizer in L-6 1987 BMW 325e engines using 10,000 mile tests run with a BMW IVD driving cycle. The chemical structure of detergents used to reduce Intake Valve Deposits (IVD) has been systematically varied to determine its effect on the quantity and the composition of CCD. In general, chemical changes in the intake valve detergent had little effect on the amount and chemical composition of CCD. The composition of CCD was determined by X-ray Photoelectron Spectroscopy (XPS). All CCDs produced with fuels containing intake valve detergents showed the same types and similar levels of organic oxygen, sulfur and aromatic carbon. The CCDs did not contain intact additive backbone fragments or detergent head groups. The only distinguishing feature of these CCDs was the varying nitrogen content that appeared to depend on the type and number of amine groups in the detergent. However, the types of nitrogen present in the CCDs were chemically different from those present in the initial detergent suggesting that, although some of the nitrogen in the detergent head group remains in the CCD, it is chemically transformed.

  16. Proteolytic Enzymes in Detergents: Evidence of Their Presence through Activity Measurements Based on Electrophoresis

    ERIC Educational Resources Information Center

    Saperas, Nuria; Fonfria-Subiros, Elsa

    2011-01-01

    This laboratory exercise uses a problem-based approach to expose students to some basic concepts relating to proteins and enzymes. One of the main applications of enzymes at the industrial level is their use in the detergent market. The students examine a detergent sample to ascertain whether proteolytic enzymes are a component and, if so, which…

  17. 40 CFR 80.155 - Interim detergent program controls and prohibitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... motor vehicles or in any off-road engines (except as provided in § 80.160), or to a gasoline retailer or... detergent registered under 40 CFR part 79, and in accordance with at least the minimum concentration specifications of that detergent as registered under 40 CFR part 79 or as otherwise provided under §...

  18. 40 CFR 417.150 - Applicability; description of the manufacture of spray dried detergents subcategory.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 29 2011-07-01 2009-07-01 true Applicability; description of the manufacture of spray dried detergents subcategory. 417.150 Section 417.150 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT...

  19. 40 CFR 417.150 - Applicability; description of the manufacture of spray dried detergents subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Applicability; description of the manufacture of spray dried detergents subcategory. 417.150 Section 417.150 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS SOAP AND DETERGENT...

  20. Optical Fibre Technology In Poland

    NASA Astrophysics Data System (ADS)

    Szustakowski, MieczysIaw; Romaniuk, Ryszard S.

    1990-02-01

    The academic and industrial community active in the field of optoelectronics in this country is organizing now every two years a major international meeting on Optical Fibres and their Applications. The first meeting was held in 1976 and the fifth in the series during February 1989. The next meeting is scheduled for February 1991. It used to gather 150 contributed and invited papers and a few hundreds of participants both domestic and international. The proceedings of this meeting are now issued by SPIE-The International Society for Optical Engineering (vols. no 670 and 1085).

  1. Continuum theory of contractile fibres

    NASA Astrophysics Data System (ADS)

    Kruse, K.; Zumdieck, A.; Jülicher, F.

    2003-12-01

    The generation of contractile forces by living cells often involves linear arrangements of actively interacting polar filaments. We develop a physical description of the dynamics of active fibers based on a general expression for the tension in terms of the filament density and the bundle polarisation. We discuss the long-time behaviour of oriented and of nonpolar fibres, discuss effects of polymerization and depolymerization, and relate this continuum theory to nonlocal descriptions of filament-motor systems. We show that a nonpolar arrangement of filaments suppresses oscillatory instabilities which could be relevant for muscle fibers.

  2. The detergent octylglucoside neutralizes lipopolysaccharide in a specific manner.

    PubMed

    Henrich, B; Guadarrama, R; Zähringer, U; MacKenzie, C R

    2001-04-01

    The stimulatory effect of lipopolysaccharide (LPS) on human macrophages was found to be neutralized by the detergent octylglucoside (OG). Both macrophage stimulation and reactivity in a limulus amebocyte lysate test were suppressed by suspension of LPS in OG at concentrations between 0.25 and 2.5 mM, whereas other stimulatory lipopeptides and lipid containing stimulants were unaffected by OG. LPS at concentrations causing maximal stimulation of macrophages could be completely neutralized by non-toxic concentrations of OG. In addition, it was found that the neutralization in complex mixtures of macromolecules, such as bacterial cell lysate, was specific for LPS and that the stimulatory activity of the other substances in the mixture was not affected by the OG.

  3. A novel method of plasmid isolation using laundry detergent.

    PubMed

    Yadav, P; Yadav, A; Garg, V; Datta, T K; Goswami, S L; De, S

    2011-07-01

    Since the discovery of plasmid, various methods have been developed to isolate plasmid DNA. All the methods have one common and important target of isolating plasmid DNA of high quality and quantity in less time. These methods are not completely safe because of use of toxic chemicals compounds. The developed protocol for plasmid extraction is based on the alkaline lysis method of plasmid preparation (extraction atpH 8.0) with slight modifications. Cell lysis reagent sodium dodecyl sulfate is replaced by lipase enzyme present in laundry detergent. A good plasmid preparation can be made, which is well suited for subsequent molecular biology applications. By taking safety measures on count, contaminants like, RNA and protein can be completely avoided with maximized plasmid yield. The resultant plasmid quality and quantity can be well comparable to other prevalent methods.

  4. Structure formation in binary mixtures of lipids and detergents: Self-assembly and vesicle division

    NASA Astrophysics Data System (ADS)

    Noguchi, Hiroshi

    2013-01-01

    Self-assembly dynamics in binary surfactant mixtures and structure changes of lipid vesicles induced by detergent solution are studied using coarse-grained molecular simulations. Disk-shaped micelles, the bicelles, are stabilized by detergents surrounding the rim of a bilayer disk of lipids. The self-assembled bicelles are considerably smaller than bicelles formed from vesicle rupture, and their size is determined by the concentrations of lipids and detergents and the interactions between the two species. The detergent-adsorption induces spontaneous curvature of the vesicle bilayer and results in vesicle division into two vesicles or vesicle rupture into worm-like micelles. The division occurs mainly via the inverse pathway of the modified stalk model. For large spontaneous curvature of the monolayers of the detergents, a pore is often opened, thereby leading to vesicle division or worm-like micelle formation.

  5. Determination of nonylphenol polyethoxylates in household detergents by high-performance liquid chromatography.

    PubMed

    Cheng, Chin-Yuan; Ding, Wang-Hsien

    2002-08-30

    Preliminary survey results of the content of nonylphenol polyethoxylates (NPEOs) in various household detergents sold in Taiwan are presented. This survey was conducted to elucidate the concentration of NPEOs in household detergents and support pollution prevention and control programs. The concentrations of NPEOs in detergents and cleaners were determined by HPLC with a C8 reversed-phase column and equipped with fluorescence detection. The accuracy and precision of the method was validated and was successfully applied to determine concentrations of NPEOs in household detergents. The results show that NPEOs were detected in 41% of 90 household detergents at concentrations from 0.2 to 21%. The highest concentration of NPEOs (21%) was detected in a laundry liquid especially designed for washing socks. Reversed-phase liquid chromatography connected with electrospray mass spectrometry confirmed the results.

  6. Chronic toxicity of a laundry detergent to the freshwater flagellate Euglena gracilis.

    PubMed

    Azizullah, Azizullah; Richter, Peter; Jamil, Muhammad; Häder, Donat-Peter

    2012-10-01

    Chronic toxicity of the common laundry detergent Ariel on the freshwater alga Euglena gracilis was investigated by growing the alga in a medium containing the detergent for 7 days. Cell density, motility, swimming velocity, gravitactic orientation, cell shape, photosynthesis and concentration of light-harvesting pigments were used as end point parameters for the assessment of toxicity. Cell density was significantly reduced at a concentration of 1 mg l(-1) or above. Among the other tested parameters, with the exception of cell shape, gravitaxis and chlorophyll b, all were adversely affected by the detergent at concentrations exceeding 1 mg l(-1). It is concluded that long-term (7-days) exposure to the detergent caused significant toxicity to E. gracilis. Furthermore, long-term tests with E. gracilis can be used as sensitive indicator for the toxicity assessment of laundry detergents in aquatic environments.

  7. Liquid automatic dishwashing detergents: a profile of toxicity.

    PubMed

    Krenzelok, E P

    1989-01-01

    The recent introduction of liquid automatic dishwashing detergents (LADDs) has resulted in numerous calls to poison information centers and, subsequently, a large number of referrals to emergency departments. As with their traditional granular counterparts, LADDs contain alkaline builders that contribute to the pH of these products. Exposure to granular automatic dishwashing detergents has been associated with caustic injury similar to the pathology produced by other alkaline corrosives. Do LADDs produce similar toxicity? There is no published information that profiles the toxic manifestations associated with exposure to LADDs. To determine their toxicity, all LADD exposures reported to a regional poison information center over a 12-month period were collected. One hundred ninety-two human exposure cases were reviewed. Pediatric patients accounted for 76% of the exposures; 76% were ingestions, 12% were dermal exposures, and 12% were ocular exposures. Seventy-nine percent of the patients were exposed to a full-strength product, and 21% contacted a dilute product or one that had already been through the dishwashing cycle. Of the patients who ingested a LADD, 91.1% remained asymptomatic, 8.2% had minor symptoms, and only one (0.7%) suffered moderate toxicity. In contrast, 91.3% of all patients who had an ocular exposure developed minor or moderate toxicity (73.9% vs 17.4%). Of dermal exposures, 69.6% were asymptomatic, and those with symptoms were the result of inappropriate use. Overall, 78.7% remained asymptomatic, 18.2% developed minor toxicity, and 3.1% developed moderate toxicity. Small oral and dermal exposures usually do not result in toxicity and do not necessitate referral to an ED. Ocular exposures are associated with a high incidence of at least minor toxicity and require ED evaluation.

  8. Dietary fibre in type II diabetes.

    PubMed

    Asp, N G; Agardh, C D; Ahrén, B; Dencker, I; Johansson, C G; Lundquist, I; Nyman, M; Sartor, G; Scherstén, B

    1981-01-01

    Recent studies have indicated that diets rich in digestible carbohydrates and dietary fibre might be beneficial in the regulation of type II non insulin dependent diabetes (NIDD). Addition of the gel forming type of dietary fibre such as pectin and guar gum to meals or glucose solutions reduces post-prandial glucose and insulin response. Addition of cereal fibres in the form of bran seems to have long term beneficial effect improving glucose tolerance. Little is known, however, concerning effects of dietary fibre naturally occurring in food on postprandial glucose and hormone response. In the present study we prepared two breakfast meals which were similar regarding digestible carbohydrates but differed in their dietary fibre content. One of the meals, including whole grain bread and whole apples, contained 8.4 g of dietary fibre, and the other one, containing white bread and apple juice, 3.1 g. When given to eight NIDD, the fibre rich breakfast gave significantly lower blood glucose increment during the three hours following ingestion. The results indicate that foods rich in dietary fibre might be useful in the regulation of type II diabetes.

  9. Calorimetric quantification of linked equilibria in cyclodextrin/lipid/detergent mixtures for membrane-protein reconstitution.

    PubMed

    Textor, Martin; Vargas, Carolyn; Keller, Sandro

    2015-04-01

    Reconstitution from detergent micelles into lipid bilayer membranes is a prerequisite for many in vitro studies on purified membrane proteins. Complexation by cyclodextrins offers an efficient and tightly controllable way of removing detergents for membrane-protein reconstitution, since cyclodextrins sequester detergents at defined stoichiometries and with tuneable affinities. To fully exploit the potential advantages of cyclodextrin for membrane-protein reconstitution, we establish a quantitative model for predicting the supramolecular transition from mixed micelles to vesicles during cyclodextrin-mediated detergent extraction. The model is based on a set of linked equilibria among all pseudophases present in the course of the reconstitution process. Various isothermal titration-calorimetric protocols are used for quantifying a detergent's self-association as well as its colloidal and stoichiometric interactions with lipid and cyclodextrin, respectively. The detergent's critical micellar concentration, the phase boundaries in the lipid/detergent phase diagram, and the dissociation constant of the cyclodextrin/detergent complex thus obtained provide all thermodynamic parameters necessary for a quantitative prediction of the transition from micelles to bilayer membranes during cyclodextrin-driven reconstitution. This is exemplified and validated by stepwise complexation of the detergent lauryldimethylamine N-oxide in mixtures with the phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine upon titration with 2-hydroxypropyl-β-cyclodextrin, both in the presence and in the absence of the membrane protein Mistic. The calorimetric approach presented herein quantitatively predicts the onset and completion of the reconstitution process, thus obviating cumbersome trial-and-error efforts and facilitating the rational optimisation of reconstitution protocols, and can be adapted to different cyclodextrin/lipid/detergent combinations.

  10. Manifestation of cryptic fibroblast tissue factor occurs at detergent concentrations which dissolve the plasma membrane.

    PubMed

    Carson, S D

    1996-04-01

    Cultured fibroblasts treated with increasing concentrations of detergents expressed only encrypted levels of tissue factor activity (measured by fX activation in the presence of fVIIa), characteristic of undamaged cells, until each detergent reached a critical concentration at which the cryptic tissue factor activity was manifested. Beyond the narrow ranges of concentrations over which the detergents stimulated tissue factor activity, the detergents were inhibitory. Studies with Triton X-100 and octyl glucoside revealed that manifestation of tissue factor activity coincided with breakdown of the plasma membrane. The magnitude of the increased tissue factor activity differed among detergents, with octyl glucoside giving the largest response. The tissue factor that was active after Triton X-100 treatment remained mostly associated with the insoluble cell residue, whereas the concentration of octyl glucoside which stimulated activity released tissue factor activity into the supernatant. Radiolabeled antibody against human tissue factor was used to show that a small percentage of the total accessible tissue factor remained in the insoluble fraction after treatment with either non-ionic detergent. Chromatographic analysis of lipids extracted from cells treated with detergents and dansyl chloride showed dansyl-reactivity of phosphatidylserine on intact cells, and solubilization of membrane lipids at sublytic concentrations of detergents. These findings reveal that there is a critical level of detergent-induced membrane damage at which tissue factor activity is maximally expressed, in essentially an all-or-none manner. The results are consistent with a major role for phospholipid asymmetry in regulation of tissue factor specific activity, but require either maintenance of asymmetry during sublytic detergent perturbation of the plasma membrane or additional control mechanisms.

  11. SpaceFibre Implementation, Test and Validation

    NASA Astrophysics Data System (ADS)

    Parkes, Steve; McClements, Chris; Ferrer, Albert; Gonzalez Villafranca, Alberto

    2014-08-01

    SpaceFibre is a very high-speed serial data-link being developed by the University of Dundee for the European Space Agency (ESA) which is intended for use in data-handling networks for high data-rate payloads. SpaceFibre is able to operate over fibre-optic and electrical cable and supports data rates of 2 Gbit/s in the near future and up to 5 Gbit/s long-term. It aims to complement the capabilities of the widely used SpaceWire onboard networking standard: improving the data rate by a factor of 12.5, reducing the cable mass and providing galvanic isolation. Multi-laning improves the data-rate further to well over 20 Gbits/s. This paper provides an introduction to SpaceFibre and then describes the work being done by various organisations to simulate, implement, test and validate SpaceFibre.

  12. Self-sensing E-glass fibres

    NASA Astrophysics Data System (ADS)

    Kister, G.; Wang, L.; Ralph, B.; Fernando, G. F.

    2003-02-01

    The primary aims of this study were to demonstrate that conventional reinforcing E-glass fibres could be converted to act as waveguides. This was achieved by selecting and applying appropriate cladding material onto the glass fibre bundle. Three classes of cladding materials were evaluated: epoxy, polyurethane and sol-gel. The light transmission characteristics through the E-glass waveguides was evaluated and compared. The epoxy and polyurethane cladding were found to be superior compared to the sol-gel coated fibres in terms of the quality of the coating and the light transmission intensity over specified lengths. The effect of fibre-end preparation on the light transmission characteristic was also investigated. The feasibility of conducting in situ tensile tests where the light transmission intensity was passed through the E-glass fibres was demonstrated successfully. This in situ technique was capable of highlighting differences in the macroscopic tensile failure modes obtained using the various cladding materials.

  13. Erbium-doped aluminophosphosilicate optical fibres

    SciTech Connect

    Likhachev, M E; Bubnov, M M; Zotov, K V; Medvedkov, O I; Lipatov, D S; Yashkov, M V; Gur'yanov, Aleksei N

    2010-09-10

    We have studied the active properties of erbium-doped aluminophosphosilicate (APS) core fibres in wide ranges of erbia, alumina and phosphorus pentoxide concentrations. The absorption and luminescence spectra of the P{sub 2}O{sub 5}- or Al{sub 2}O{sub 3}-enriched erbium-doped APS fibres are shown to be similar to those of the erbium-doped fibres singly doped with phosphorus pentoxide or alumina, respectively. The formation of AlPO{sub 4} in APS fibres leads not only to a reduction in the refractive index of the glass but also to a marked increase in Er{sub 2}O{sub 3} solubility in silica. (optical fibres)

  14. Supercontinuum generation in thulium-doped fibres

    SciTech Connect

    Kurkov, Andrei S; Kamynin, V A; Tsvetkov, V B; Sadovnikova, Ya E; Marakulin, A V; Minashina, L A

    2012-09-30

    Supercontinuum generation in thulium-doped fibres under pumping at 1.59 {mu}m is investigated. Amplification of supercontinuum in the range of 1.8--2.0 {mu}m is found for a fibre doped to a level of 2 Multiplication-Sign 10{sup 19} cm{sup -3}. For a fibre with an activator concentration of 2 Multiplication-Sign 10{sup 20} cm{sup -3} amplification is also observed in the (2.1 - 2.45)-{mu}m band, which suggests the occurrence of the {sup 3}H{sub 4} {yields} {sup 3}H{sub 5} optical transition in the fibre. The occupation of the {sup 3}H{sub 4} level can be explained by cooperative effects. (optical fibres, lasers and amplifiers. properties and applications)

  15. Modulation of distal colonic epithelial barrier function by dietary fibre in normal rats

    PubMed Central

    Mariadason, J; Catto-Smith, A; Gibson, P

    1999-01-01

    BACKGROUND—Dietary fibre influences the turnover and differentiation of the colonic epithelium, but its effects on barrier function are unknown. 
AIMS—To determine whether altering the type and amount of fibre in the diet affects paracellular permeability of intestinal epithelium, and to identify the mechanisms of action. 
METHODS—Rats were fed isoenergetic low fibre diets with or without supplements of wheat bran (10%) or methylcellulose (10%), for four weeks. Paracellular permeability was determined by measurement of conductance and 51Cr-EDTA flux across tissue mounted in Ussing chambers. Faecal short chain fatty acid (SCFA) concentrations were assessed by gas chromatography, epithelial kinetics stathmokinetically, and mucosal brush border hydrolase activities spectrophotometrically. 
RESULTS—Body weight was similar across the dietary groups. Conductance and 51Cr-EDTA flux were approximately 25% higher in animals fed no fibre, compared with those fed wheat bran or methylcellulose in the distal colon, but not in the caecum or jejunum. Histologically, there was no evidence of epithelial injury or erosion associated with any diet. The fibres exerted different spectra of effects on luminal SCFA concentrations and pH, and on mucosal indexes, but both bulked the faeces, were trophic to the epithelium, and stimulated expression of a marker of epithelial differentiation. 
CONCLUSIONS—Both a fermentable and a non-fermentable fibre reduce paracellular permeability specifically in the distal colon, possibly by promoting epithelial cell differentiation. The mechanisms by which the two fibres exert their effects are likely to be different. 

 Keywords: colon; differentiation; epithelium; fibre; paracellular permeability; proliferation PMID:10026327

  16. Detergent-free Isolation of Functional G Protein-Coupled Receptors into Nanometric Lipid Particles.

    PubMed

    Logez, Christel; Damian, Marjorie; Legros, Céline; Dupré, Clémence; Guéry, Mélody; Mary, Sophie; Wagner, Renaud; M'Kadmi, Céline; Nosjean, Olivier; Fould, Benjamin; Marie, Jacky; Fehrentz, Jean-Alain; Martinez, Jean; Ferry, Gilles; Boutin, Jean A; Banères, Jean-Louis

    2016-01-12

    G protein-coupled receptors (GPCRs) are integral membrane proteins that play a pivotal role in signal transduction. Understanding their dynamics is absolutely required to get a clear picture of how signaling proceeds. Molecular characterization of GPCRs isolated in detergents nevertheless stumbles over the deleterious effect of these compounds on receptor function and stability. We explored here the potential of a styrene-maleic acid polymer to solubilize receptors directly from their lipid environment. To this end, we used two GPCRs, the melatonin and ghrelin receptors, embedded in two membrane systems of increasing complexity, liposomes and membranes from Pichia pastoris. The styrene-maleic acid polymer was able, in both cases, to extract membrane patches of a well-defined size. GPCRs in SMA-stabilized lipid discs not only recognized their ligand but also transmitted a signal, as evidenced by their ability to activate their cognate G proteins and recruit arrestins in an agonist-dependent manner. Besides, the purified receptor in lipid discs undergoes all specific changes in conformation associated with ligand-mediated activation, as demonstrated in the case of the ghrelin receptor with fluorescent conformational reporters and compounds from distinct pharmacological classes. Altogether, these data highlight the potential of styrene-maleic stabilized lipid discs for analyzing the molecular bases of GPCR-mediated signaling in a well-controlled membrane-like environment. PMID:26701065

  17. Fibre-Matrix Interaction in Soft Tissue

    SciTech Connect

    Guo, Zaoyang

    2010-05-21

    Although the mechanical behaviour of soft tissue has been extensively studied, the interaction between the collagen fibres and the ground matrix has not been well understood and is therefore ignored by most constitutive models of soft tissue. In this paper, the human annulus fibrosus is used as an example and the potential fibre-matrix interaction is identified by careful investigation of the experimental results of biaxial and uniaxial testing of the human annulus fibrosus. First, the uniaxial testing result of the HAF along the axial direction is analysed and it is shown that the mechanical behaviour of the ground matrix can be well simulated by the incompressible neo-Hookean model when the collagen fibres are all under contraction. If the collagen fibres are stretched, the response of the ground matrix can still be described by the incompressible neo-Hookean model, but the effective stiffness of the matrix depends on the fibre stretch ratio. This stiffness can be more than 10 times larger than the one obtained with collagen fibres under contraction. This phenomenon can only be explained by the fibre-matrix interaction. Furthermore, we find that the physical interpretation of this interaction includes the inhomogeneity of the soft tissue and the fibre orientation dispersion. The dependence of the tangent stiffness of the matrix on the first invariant of the deformation tensor can also be explained by the fibre orientation dispersion. The significant effect of the fibre-matrix interaction strain energy on mechanical behaviour of the soft tissue is also illustrated by comparing some simulation results.

  18. Highly efficient Raman distributed feedback fibre lasers.

    PubMed

    Shi, Jindan; Alam, Shaif-ul; Ibsen, Morten

    2012-02-27

    We demonstrate highly efficient Raman distributed feedback (DFB) fibre lasers for the first time with up to 1.6 W of continuous wave (CW) output power. The DFB Bragg gratings are written directly into two types of commercially available passive germano-silica fibres. Two lasers of 30 cm length are pumped with up to 15 W of CW power at 1068 nm. The threshold power is ~2 W for a Raman-DFB (R-DFB) laser written in standard low-NA fibre, and only ~1 W for a laser written in a high-NA fibre, both of which oscillate in a narrow linewidth of <0.01 nm at ~1117 nm and ~1109 nm, respectively. The slope efficiencies are ~74% and ~93% with respect to absorbed pump power in the low-NA fibre and high-NA fibre respectively. Such high conversion efficiency suggests that very little energy is lost in the form of heat through inefficient energy transfer. Our results are supported by numerical simulations, and furthermore open up for the possibility of having narrow linewidth all-fibre laser sources in wavelength bands not traditionally covered by rare-earth doped silica fibres. Simulations also imply that this technology has the potential to produce even shorter R-DFB laser devices at the centimetre-level and with mW-level thresholds, if Bragg gratings formed in fibre materials with higher intrinsic Raman gain coefficient than silica are used. These materials include for example tellurite or chalcogenide glasses. Using glasses like these would also open up the possibility of having narrow linewidth fibre sources with DFB laser oscillating much further into the IR than what currently is possible with rare-earth doped silica glasses. PMID:22418313

  19. Highly efficient Raman distributed feedback fibre lasers.

    PubMed

    Shi, Jindan; Alam, Shaif-ul; Ibsen, Morten

    2012-02-27

    We demonstrate highly efficient Raman distributed feedback (DFB) fibre lasers for the first time with up to 1.6 W of continuous wave (CW) output power. The DFB Bragg gratings are written directly into two types of commercially available passive germano-silica fibres. Two lasers of 30 cm length are pumped with up to 15 W of CW power at 1068 nm. The threshold power is ~2 W for a Raman-DFB (R-DFB) laser written in standard low-NA fibre, and only ~1 W for a laser written in a high-NA fibre, both of which oscillate in a narrow linewidth of <0.01 nm at ~1117 nm and ~1109 nm, respectively. The slope efficiencies are ~74% and ~93% with respect to absorbed pump power in the low-NA fibre and high-NA fibre respectively. Such high conversion efficiency suggests that very little energy is lost in the form of heat through inefficient energy transfer. Our results are supported by numerical simulations, and furthermore open up for the possibility of having narrow linewidth all-fibre laser sources in wavelength bands not traditionally covered by rare-earth doped silica fibres. Simulations also imply that this technology has the potential to produce even shorter R-DFB laser devices at the centimetre-level and with mW-level thresholds, if Bragg gratings formed in fibre materials with higher intrinsic Raman gain coefficient than silica are used. These materials include for example tellurite or chalcogenide glasses. Using glasses like these would also open up the possibility of having narrow linewidth fibre sources with DFB laser oscillating much further into the IR than what currently is possible with rare-earth doped silica glasses.

  20. The influence of dietary fibre source and level on the development of the gastrointestinal tract, digestibility and energy metabolism in broiler chickens.

    PubMed

    Jørgensen, H; Zhao, X Q; Knudsen, K E; Eggum, B O

    1996-03-01

    The present study was undertaken to provide detailed information about the effect of fibre source (pea fibre, wheat bran or oat bran) at inclusion levels of 0, 187 and 375 g/kg diet on the development of the digestive tract, nutrient digestibility and energy and protein metabolism in broiler chickens. Heat production was measured using open-air-circuit respiration chambers. Diets with increasing levels of pea fibre decreased the DM in droppings and increased excreta output (2.5-fold) relative to DM intake. Adaptation to increased dietary fibre levels included increases in the size of the digestive system, with pea fibre exerting a stronger impact than wheat bran or oat bran. The length of the intestine, and particularly the length and weight of the caecum, increased with the fibre level. The digestibility of all nutrients also decreased with increasing fibre level. The decrease in the digestibility in relation to NSP for the three fibre sources was bigger for oat bran (0.0020 per g dietary NSP) than for pea fibre and wheat bran (0.0014 and 0.0016 per g dietary NSP) indicating that the cell walls in oat bran (aleurone and subaleurone) had a significant negative effect on the digestibility of cellular nutrients, i.e. protein and fat. The degradation of the NSP constituents was far lower in chickens than found in other animal species such as pigs and rats, thus supporting the view that chickens do not ferment fibre polymers to a great extent. Excretion of organic acids (mainly lactic acid and acetic acid) accounted for up to 2% of metabolizable energy (ME) intake with the highest excretion for the high-fibre diets. H2 excretion was related to the amount of NSP degraded and indicated higher microbial fermentation with increasing fibre levels. The chickens' feed intake responded to a great extent to dietary ME concentration but expressed in terms of metabolic body size (W0.75) ME intake was depressed at the high fibre levels. Dietary NSP was able to explain between 86

  1. Low-temperature washing of patients' clothing; effects of detergent with disinfectant and a tunnel drier on bacterial survival.

    PubMed

    Tompkins, D S; Johnson, P; Fittall, B R

    1988-07-01

    Patients' dresses were washed at 40 degrees C using an ordinary detergent for 1 week and a novel detergent with added 'Triclosan' for the following 2 weeks. The bacterial load on the finished laundry was acceptably low using either detergent. The killing of residual bacteria on washed clothing by drying in a tunnel finisher was demonstrated. This preliminary study did not show any benefits to be gained from the addition of 'Triclosan' to detergent for the low-temperature laundering of patients' clothing.

  2. A detergent-like mechanism of action of the cytolytic toxin Cyt1A from Bacillus thuringiensis var. israelensis.

    PubMed

    Manceva, Slobodanka D; Pusztai-Carey, Marianne; Russo, Paul S; Butko, Peter

    2005-01-18

    The cytolytic delta-endotoxin Cyt1A from Bacillus thuringiensis var. israelensis is used in commercial preparations of environmentally safe insecticides. The current hypothesis on its mode of action is that the toxin self-assembles into well-defined cation-selective channels or pores, which results in colloid-osmotic lysis of the cell. Recently, a new hypothesis has been put forward suggesting that Cyt1A rather nonspecifically aggregates on the membrane surface and acts in a detergent-like manner. To distinguish between these two hypotheses, we investigated whether in the presence of lipid Cyt1A self-assembles into stoichiometric oligomers, which are characteristic of pores or channels, or aggregates into nonstoichiometric complexes, which would support the detergent-like model. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that in the presence of lipid Cyt1A forms protein aggregates with a broad range of molecular weights, some being too large to enter the gel. Cyt1A tryptophan (Trp) fluorescence in the presence of lipid exhibited a decrease in anisotropy and quantum yield, but an unchanged lifetime, which is consistent with the presence of toxin aggregates in the membrane. Electrostatic interactions between the charged amino acid residues and the lipid headgroups are responsible for bringing the protein to the membrane surface, while hydrophobic and/or van der Waals interactions make the membrane binding irreversible. Fluorescence photobleaching recovery, a technique that measures the diffusion coefficient of fluorescently labeled particles, and epifluorescence microscopy revealed that upon addition of Cyt1A lipid vesicles were broken into smaller, faster diffusing objects. Since no change in size or morphology of the vesicles is expected when pores are formed in the osmotically equilibrated membranes, our results support the detergent-like mode of action of Cyt1A.

  3. Dietary fibres as "prebiotics": implications for colorectal cancer.

    PubMed

    Lim, Chiara C; Ferguson, Lynnette R; Tannock, Gerald W

    2005-06-01

    A "prebiotic" is a nondigestible food ingredient whose beneficial effects on the host result from the selective stimulation of growth and/or activity of members of the bacterial community that inhabits the human bowel (the gut microbiota). Although much of the prebiotic literature focuses on nondigestible oligosaccharides, such as oligofructose, most dietary fibres that are fermentable carbohydrates could be considered as prebiotics. Early studies suggested that colonic bacteria were risk factors for colon cancer. However, altering the composition or metabolic activity of the bowel microbiota through the use of dietary fibre might be important in reducing the prevalence of colorectal cancer. Mechanisms for beneficial effects of prebiotics might include changing the activity of exogenous carcinogens through modulating metabolic activation and/or detoxification, or stimulating the production of the short-chain fatty acid, butyrate. However, modern analytical techniques suggest that an important consequence of a modified bacterial community could be a change in the expression not only of a range of different bacterial genes in bowel contents, but also in the bowel mucosa of the host. Analogous with observations with probiotics, the stimulation of cytokines and modification of immune responses could be important in producing beneficial effects. Compared with transitory effects of probiotics, the prebiotic action of fermentable carbohydrates potentially provide the opportunity for sustainable modulation of activity of the gut microbiota. However, their mechanisms of action in humans are speculative, and research aimed at providing an integrated view of the gut microbiota and dietary fibre nutrition of humans needs to be developed.

  4. Knowledge about dietary fibre: a fibre study framework.

    PubMed

    Guiné, Raquel P F; Ferreira, Manuela; Correia, Paula; Duarte, João; Leal, Marcela; Rumbak, Ivana; Barić, Irena C; Komes, Drazenka; Satalić, Zvonimir; Sarić, Marijana M; Tarcea, Monica; Fazakas, Zita; Jovanoska, Dijana; Vanevski, Dragoljub; Vittadini, Elena; Pellegrini, Nicoletta; Szűcs, Viktória; Harangozó, Júlia; El-Kenawy, Ayman; El-Shenawy, Omnia; Yalçın, Erkan; Kösemeci, Cem; Klava, Dace; Straumite, Evita

    2016-09-01

    The objective of this work was to study the degree of knowledge about dietary fibre (DF), as influenced by factors such as gender, level of education, living environment or country. For this, a descriptive cross-sectional study was undertaken on a non-probabilistic sample of 6010 participants from 10 countries in different continents (Europe, Africa and America). The results showed that the participants revealed on average a positive but still low global level of knowledge, which alerts for the need to take some actions to further inform the population about DF and its role as a component of a healthy diet. The results also indicated differences between genders, levels of education, living environments and countries. The highest level of knowledge was revealed by the participants from female gender, with higher education and living in urban areas. Concerning the country, the best informed were the participants from Romania, followed by those from Portugal and Turkey while the least informed were from Egypt.

  5. Pathways associated with lignin biosynthesis in lignomaniac jute fibres.

    PubMed

    Chakraborty, Avrajit; Sarkar, Debabrata; Satya, Pratik; Karmakar, Pran Gobinda; Singh, Nagendra Kumar

    2015-08-01

    We generated the bast transcriptomes of a deficient lignified phloem fibre mutant and its wild-type jute (Corchorus capsularis) using Illumina paired-end sequencing. A total of 34,163 wild-type and 29,463 mutant unigenes, with average lengths of 1442 and 1136 bp, respectively, were assembled de novo, ~77-79 % of which were functionally annotated. These annotated unigenes were assigned to COG (~37-40 %) and GO (~22-28 %) classifications and mapped to 189 KEGG pathways (~19-21 %). We discovered 38 and 43 isoforms of 16 and 10 genes of the upstream shikimate-aromatic amino acid and downstream monolignol biosynthetic pathways, respectively, rendered their sequence similarities, confirmed the identities of 22 of these candidate gene families by phylogenetic analyses and reconstructed the pathway leading to lignin biosynthesis in jute fibres. We also identified major genes and bast-related transcription factors involved in secondary cell wall (SCW) formation. The quantitative RT-PCRs revealed that phenylalanine ammonia-lyase 1 (CcPAL1) was co-down-regulated with several genes of the upstream shikimate pathway in mutant bast tissues at an early growth stage, although its expression relapsed to the normal level at the later growth stage. However, cinnamyl alcohol dehydrogenase 7 (CcCAD7) was strongly down-regulated in mutant bast tissues irrespective of growth stages. CcCAD7 disruption at an early growth stage was accompanied by co-up-regulation of SCW-specific genes cellulose synthase A7 (CcCesA7) and fasciclin-like arabinogalactan 6 (CcFLA6), which was predicted to be involved in coordinating the S-layers' deposition in the xylan-type jute fibres. Our results identified CAD as a promising target for developing low-lignin jute fibres using genomics-assisted molecular approaches.

  6. Pathways associated with lignin biosynthesis in lignomaniac jute fibres.

    PubMed

    Chakraborty, Avrajit; Sarkar, Debabrata; Satya, Pratik; Karmakar, Pran Gobinda; Singh, Nagendra Kumar

    2015-08-01

    We generated the bast transcriptomes of a deficient lignified phloem fibre mutant and its wild-type jute (Corchorus capsularis) using Illumina paired-end sequencing. A total of 34,163 wild-type and 29,463 mutant unigenes, with average lengths of 1442 and 1136 bp, respectively, were assembled de novo, ~77-79 % of which were functionally annotated. These annotated unigenes were assigned to COG (~37-40 %) and GO (~22-28 %) classifications and mapped to 189 KEGG pathways (~19-21 %). We discovered 38 and 43 isoforms of 16 and 10 genes of the upstream shikimate-aromatic amino acid and downstream monolignol biosynthetic pathways, respectively, rendered their sequence similarities, confirmed the identities of 22 of these candidate gene families by phylogenetic analyses and reconstructed the pathway leading to lignin biosynthesis in jute fibres. We also identified major genes and bast-related transcription factors involved in secondary cell wall (SCW) formation. The quantitative RT-PCRs revealed that phenylalanine ammonia-lyase 1 (CcPAL1) was co-down-regulated with several genes of the upstream shikimate pathway in mutant bast tissues at an early growth stage, although its expression relapsed to the normal level at the later growth stage. However, cinnamyl alcohol dehydrogenase 7 (CcCAD7) was strongly down-regulated in mutant bast tissues irrespective of growth stages. CcCAD7 disruption at an early growth stage was accompanied by co-up-regulation of SCW-specific genes cellulose synthase A7 (CcCesA7) and fasciclin-like arabinogalactan 6 (CcFLA6), which was predicted to be involved in coordinating the S-layers' deposition in the xylan-type jute fibres. Our results identified CAD as a promising target for developing low-lignin jute fibres using genomics-assisted molecular approaches. PMID:25724692

  7. Response of an environment-sensitive intramolecular charge transfer probe towards solubilization of liposome membranes by a non-ionic detergent: Association and dissociation kinetics

    NASA Astrophysics Data System (ADS)

    Paul, Bijan Kumar; Guchhait, Nikhil

    2012-10-01

    The present report describes an endeavor to follow the solubilization of DMPC and DMPG liposome membranes by a non-ionic detergent Triton X-100 on the lexicon of environment-sensitive intramolecular charge transfer (ICT) photophysics of an extrinsic molecular probe 5-(4-dimethylamino-phenyl)-penta-2, 4-dienoic acid methyl ester (DPDAME). The prospective applicability of the probe to function as a reporter for detergent-sequestered solubilization of liposome membranes is argued on the basis of comparison of the spectral properties of the probe in various environments. Fluorescence anisotropy study delineates the degree of motional restriction imposed on the probe in different microheterogeneous assemblies. The kinetics of association of the probe with the liposome membranes and the dissociation kinetics of TX-100-sequestered solubilization process of the liposomes have been monitored by the stopped-flow fluorescence technique and the results are rationalized in relevance to fluorescence anisotropy study.

  8. Cellular localization and detergent dependent oligomerization of rice allene oxide synthase-1.

    PubMed

    Yoeun, Sereyvath; Kim, Jeong-Il; Han, Oksoo

    2015-01-01

    Allene oxide synthase-1 from Oryza sativa (OsAOS1) localizes to the chloroplast, but lacks a putative chloroplast targeting sequence typically found in dicot AOS. Here, kinetic parameters and the oligomerization state/subunit composition of OsAOS1 were characterized in vitro in the absence or presence of detergent micelles. The catalytic efficiency (k(cat)/K(m)) of OsAOS1 reached a maximum near the critical micelle concentration for polyoxyethylene 10 tridecyl ether. Native gel analysis showed that OsAOS1 exists as a multimer in the absence of detergent micelles. The multimeric form of OsAOS1 was stably cross-linked in the absence of detergents, while only monomeric OsAOS1 was detected in the presence of detergent micelles. Gel filtration analysis indicated that the oligomeric state of OsAOS1 depends strongly on the detergents and that the monomer becomes the predominant form in the presence of detergent micelles. These data suggest that the detergent-dependent oligomeric state of OsAOS1 is an important factor for the regulation of its catalytic efficiency.

  9. All-atom molecular dynamics simulation of a photosystem i/detergent complex.

    PubMed

    Harris, Bradley J; Cheng, Xiaolin; Frymier, Paul

    2014-10-01

    All-atom molecular dynamics (MD) simulation was used to investigate the solution structure and dynamics of the photosynthetic pigment-protein complex photosystem I (PSI) from Thermosynechococcus elongatus embedded in a toroidal belt of n-dodecyl-β-d-maltoside (DDM) detergent. Evaluation of root-mean-square deviations (RMSDs) relative to the known crystal structure show that the protein complex surrounded by DDM molecules is stable during the 200 ns simulation time, and root-mean-square fluctuation (RMSF) analysis indicates that regions of high local mobility correspond to solvent-exposed regions such as turns in the transmembrane α-helices and flexible loops on the stromal and lumenal faces. Comparing the protein-detergent complex to a pure detergent micelle, the detergent surrounding the PSI trimer is found to be less densely packed but with more ordered detergent tails, contrary to what is seen in most lipid bilayer models. We also investigated any functional implications for the observed conformational dynamics and protein-detergent interactions, discovering interesting structural changes in the psaL subunits associated with maintaining the trimeric structure of the protein. Importantly, we find that the docking of soluble electron mediators such as cytochrome c6 and ferredoxin to PSI is not significantly impacted by the solubilization of PSI in detergent.

  10. Detergents modify proteinase K resistance of PrP Sc in different transmissible spongiform encephalopathies (TSEs).

    PubMed

    Breyer, Johanna; Wemheuer, Wiebke M; Wrede, Arne; Graham, Catherine; Benestad, Sylvie L; Brenig, Bertram; Richt, Jürgen A; Schulz-Schaeffer, Walter J

    2012-05-25

    Prion diseases are diagnosed by the detection of their proteinase K-resistant prion protein fragment (PrP(Sc)). Various biochemical protocols use different detergents for the tissue preparation. We found that the resistance of PrP(Sc) against proteinase K may vary strongly with the detergent used. In our study, we investigated the influence of the most commonly used detergents on eight different TSE agents derived from different species and distinct prion disease forms. For a high throughput we used a membrane adsorption assay to detect small amounts of prion aggregates, as well as Western blotting. Tissue lysates were prepared using DOC, SLS, SDS or Triton X-100 in different concentrations and these were digested with various amounts of proteinase K. Detergents are able to enhance or diminish the detectability of PrP(Sc) after proteinase K digestion. Depending on the kind of detergent, its concentration - but also on the host species that developed the TSE and the disease form or prion type - the detectability of PrP(Sc) can be very different. The results obtained here may be helpful during the development or improvement of a PrP(Sc) detection method and they point towards a detergent effect that can be additionally used for decontamination purposes. A plausible explanation for the detergent effects described in this article could be an interaction with the lipids associated with PrP(Sc) that may stabilize the aggregates.

  11. Detergent Analysis in Protein Samples Using Mid-Infrared (MIR) Spectroscopy.

    PubMed

    Das, Chandreyee; Nadler, Timothy; Strug, Ivona

    2015-08-03

    Quantitating relative levels of detergent present in protein preparations or samples derived from biological material, such as tissue or body fluids, is important because the presence of detergent may affect downstream analyses as well as protein structure/function. Especially because sample volumes, analysts' available time, and other resources may be limited, a method that consumes little sample and that is rapid and simple is needed for detergent analysis. It would also be preferable to have a method that is generally applicable across many aliphatic chain-containing molecules with many different physical properties. In this unit, methods are described for analyzing detergents and proteins in detergent-protein mixtures using mid-infrared (MIR) spectroscopy. A protocol is also included for efficient removal of unbound detergents from a protein sample accompanied by MIR-based monitoring of both detergent and protein content. This rapid monitoring of sample preparation during the workflow enables users to make timely decisions about sample preparation strategies that maximize both analyte purity and yield.

  12. Effect of detergents on the thermal behavior of elastin-like polypeptides.

    PubMed

    Thapa, Arjun; Han, Wei; Simons, Robin H; Chilkoti, Ashutosh; Chi, Eva Y; López, Gabriel P

    2013-01-01

    Elastin-like polypeptide (ELP) fusions have been designed to allow large-scale, nonchromatographic purification of many soluble proteins by using the inverse transition cycling (ITC) method; however, the sensitivity of the aqueous lower critical solubility phase transition temperature (T(t)) of ELPs to the addition of cosolutes, including detergents, may be a potential hindrance in purification of proteins with surface hydrophobicity in such a manner. To identify detergents that are known to solubilize such proteins (e.g., membrane proteins) and that have little effect on the T(t) of the ELP, we screened a number of detergents with respect to their effects on the T(t) and secondary structures of a model ELP (denoted here as ELP180). We found that mild detergents (e.g., n-dodecyl-β-D-maltoside, Triton-X100, and 3-[(3-cholamidopropyl) dimethylamino]-1-propanesulfonate) do not alter the phase transition behavior or structure (as probed by circular dichroism) of ELP180. This result is in contrast to previous studies that showed a strong effect of other detergents (e.g., sodium dodecylsulfate) on the T(t) of ELPs. Our results clearly indicate that mild detergents do not preclude ITC-based separation of ELPs, and thus that ELP fusions may prove to be useful in the purification of detergent-solubilized recombinant hydrophobic proteins, including membrane proteins, which are otherwise notoriously difficult to extract and purify by conventional separation methods (e.g., chromatography).

  13. The use of non-ionic detergents in sanitary cleansing: a report of a preliminary trial.

    PubMed

    Willington, F L

    1978-07-01

    A preliminary trial was carried out to establish the most suitable hygienic wipe for sanitary cleansing in incontinence and to study and compare the difference between cleansing with soap and non-ionic detergents in incontinent patients. Four non-ionic detergents were tested against National Health toilet soap in 290 incontinent episodes. Other observations were made on the skin condition following cleansing, the ease of cleansing, odour control, detergency, and allergenicity. The results showed that a scrim wipe was the best for this purpose and also indicated that the non-ionic detergent Cetomacrogol 1000 B.P.C. to be preferential to all other creams and soap in the time taken for cleansing. The skin condition, odour control and detergent ability were all superior with this cream. It was revealed by the trial that in cleansing faecal incontinence with non-ionic detergent, an initial wipe, followed by about 7.0 grams of detergent on a moistened wipe to achieve emulsification and than followed by another dry wipe, is all that is required. The condition of the skin was recorded as excellent and the figures indicated a possible saving of 20% in nursing time.

  14. A study of cleansing property of detergents on cotton, polyester and their blend

    NASA Astrophysics Data System (ADS)

    Patel, Vaishali P.

    Proper cleaning of clothes is one of the important aspects to be considered for increasing their life. Soil gets accumulated on textiles which needs to be cleaned for reusability. There are a variety of textile materials available and a variety brands of detergents for laundry purpose, to select the right brand is of much importance as it is based on detergent performance and money spent. The present study is an effort to determine which are the various popular brands of detergents, and to study the ability of cleaning property of a few of them. Eight brand of detergents namely: Ariel Microshine, Surf Excel, Surf, Super Nirma, Super Wheel with lemon, Hipolin, Rin were studied by artificially soiling of cotton, polyester and cotton/polyester blend fabrics, at four different concentration of soiling of washing with four different concentration of detergents. Both hand washing and machine washing technique was followed. All the detergent showed batter cleaning in hand washing technique in comparison with machine washing amongst all the various brands of detergents studied, Ariel Microshine show the best cleaning property, the poorest were Wheel and Rin. Ariel Microshine was the costliest of all. The best bargain in terms of cleansing property and price was Hipolin.

  15. GbTCP, a cotton TCP transcription factor, confers fibre elongation and root hair development by a complex regulating system.

    PubMed

    Hao, Juan; Tu, Lili; Hu, Haiyan; Tan, Jiafu; Deng, Fenglin; Tang, Wenxin; Nie, Yichun; Zhang, Xianlong

    2012-10-01

    As the most important natural raw material for textile industry, cotton fibres are an excellent model for studying single-cell development. Although expression profiling and functional genomics have provided some data, the mechanism of fibre development is still not well known. A class I TCP transcription factor (designated GbTCP), encoding 344 amino acids, was isolated from the normalized cDNA library of sea-island cotton fibre (from -2 to 25 days post anthesis). GbTCP was preferentially expressed in the elongating cotton fibre from 5 to 15 days post anthesis. Some expression was also observed in stems, apical buds, and petals. RNAi silencing of GbTCP produced shorter fibre, a reduced lint percentage, and a lower fibre quality than the wild-type plants. Overexpression of GbTCP enhanced root hair initiation and elongation in Arabidopsis and regulated branching. Solexa sequencing and Affymetrix GeneChip analysis indicated that GbTCP positively regulates the level of jasmonic acid (JA) and, as a result, activates downstream genes (reactive oxygen species, calcium signalling, ethylene biosynthesis and response, and several NAC and WRKY transcription factors) necessary for elongation of fibres and root hairs. JA content analysis in cotton also confirmed that GbTCP has a profound effect on JA biosynthesis. In vitro ovule culture showed that an appropriate concentration of JA promoted fibre elongation. The results suggest that GbTCP is an important transcription factor for fibre and root hair development by regulating JA biosynthesis and response and other pathways, including reactive oxygen species, calcium channel and ethylene signalling.

  16. Chalcogenide-tellurite composite microstructured optical fibre

    NASA Astrophysics Data System (ADS)

    Kohoutek, T.; Duan, Z.; Kawashima, H.; Yan, X.; Suzuki, T.; Matsumoto, M.; Misumi, Takashi; Ohishi, Y.

    2012-02-01

    We report on fabrication a composite microstructured optical fibre composed of highly nonlinear chalcogenide Ge-Ga- Sb-S glass core and tellurite TeO2-ZnO-Li20-Bi2O3 glass clad. We aimed at obtaining more flattened chromatic dispersion for pumping chalcogenide glass based optical fibre by a pulse laser at current telecommunication wavelengths, i.e. λ = 1.35 - 1.7 μm, which is difficult to achieve by using a single material chalcogenide fibers due to their high refractive index (n > 2.1). A fibre design exploiting a composite of two glasses and one ring of the air holes brings similar options for tuning the fibre dispersion such as use of complex multi rings of air-holes approach. A good choice of glasses, allows for fabricating a composite chalcogenide-tellurite optical fibre benefiting from high nonlinearity of chalcogenide core glass but exploiting a tellurite glass technology and fibre drawing. In the paper, we discuss some aspects of CMOF design concerning current chalcogenide and tellurite glass choice. Also, we show the supercontinuum spectra recorded from current chalcogenide-tellurite CMOF pumped with a custom made femtosecond fibre laser at λ = 1.55 μm with the pulse duration of 400 fs.

  17. Small fibre function in primary autonomic failure.

    PubMed

    Baron, R; Feldmann, R; Lindner, V

    1993-12-01

    A case of primary autonomic failure (AF) with uncomplicated Parkinson's disease is presented with clinical and neurophysiological data. Special emphasis is placed on new methods of examining impairment of unmyelinated sympathetic and afferent C-fibres. Sympathetic vasoconstrictor responses in the skin induced by deep inspiration were examined quantitatively with laser Doppler flowmetry. The vasoconstriction was markedly depressed in primary AF compared with healthy controls and similar to secondary forms of AF. Peripheral nociceptive C-fibre function was quantitatively assessed by measurement of axon reflex vasodilatation induced by histamine iontophoresis. The axon reflex vasodilatation was completely intact in primary AF in contrast to patients with secondary peripheral small fibre neuropathy. The results indicate that sympathetic C-fibres are considerably affected by the degenerative disease, whereas the afferent C-fibres seem to be totally preserved. Modern neurophysiological methods of testing sympathetic and afferent small fibre function in combination with other neurophysiological tests, e.g. brain-stem auditory evoked potentials, might help to diagnose and differentiate primary AF in early stages and make it easier to distinguish between secondary autonomic neuropathies of unknown origin that often also involve unmyelinated afferent fibres. PMID:8138830

  18. Dependence of micelle size and shape on detergent alkyl chain length and head group.

    PubMed

    Oliver, Ryan C; Lipfert, Jan; Fox, Daniel A; Lo, Ryan H; Doniach, Sebastian; Columbus, Linda

    2013-01-01

    Micelle-forming detergents provide an amphipathic environment that can mimic lipid bilayers and are important tools for solubilizing membrane proteins for functional and structural investigations in vitro. However, the formation of a soluble protein-detergent complex (PDC) currently relies on empirical screening of detergents, and a stable and functional PDC is often not obtained. To provide a foundation for systematic comparisons between the properties of the detergent micelle and the resulting PDC, a comprehensive set of detergents commonly used for membrane protein studies are systematically investigated. Using small-angle X-ray scattering (SAXS), micelle shapes and sizes are determined for phosphocholines with 10, 12, and 14 alkyl carbons, glucosides with 8, 9, and 10 alkyl carbons, maltosides with 8, 10, and 12 alkyl carbons, and lysophosphatidyl glycerols with 14 and 16 alkyl carbons. The SAXS profiles are well described by two-component ellipsoid models, with an electron rich outer shell corresponding to the detergent head groups and a less electron dense hydrophobic core composed of the alkyl chains. The minor axis of the elliptical micelle core from these models is constrained by the length of the alkyl chain, and increases by 1.2-1.5 Å per carbon addition to the alkyl chain. The major elliptical axis also increases with chain length; however, the ellipticity remains approximately constant for each detergent series. In addition, the aggregation number of these detergents increases by ∼16 monomers per micelle for each alkyl carbon added. The data provide a comprehensive view of the determinants of micelle shape and size and provide a baseline for correlating micelle properties with protein-detergent interactions.

  19. Fibre-optic-based fluoroimmunosensors

    SciTech Connect

    Sepaniak, M.J. ); Vodinh, T. )

    1990-01-01

    Remote sensing of chemicals can be performed using fibre optic chemical sensors that use immunochemical reagent phases. Exploiting the specificity of antibody-antigen interactions and the sensitivity of laser-excited fluorimetry, highly selective measurements of ultra-trace levels of chemicals can be performed remotely and in situ via fluoroimmunoassay techniques. In this work, heterogeneous assay protocols using immunobeads are implemented. A passive sensor that samples analyte by diffusion through a permeable membrane and is capable of a single analysis is described and used for the measurement of a naturally fluorescent compound. Subsequently, a regenerable sensor that can perform assay procedures in a repetitive fashion is described and characterized. The versatility of this sensor for performing remote measurements using a variety of established fluorimmunoassay methodologies is discussed.

  20. Harmful Effects of Synthetic Surface-Active Detergents against Atopic Dermatitis

    PubMed Central

    Deguchi, Hajime; Aoyama, Riho; Takahashi, Hideaki; Isobe, Yoshinari; Tsutsumi, Yutaka

    2015-01-01

    We report herein two cases of intractable atopic dermatitis successfully treated by simply avoiding the contact with surface-active detergents in the daily life and living. The detergents were closely related to the exacerbation and remission of the disease. Steroid ointment was no longer used. We discuss that the removal of horny layer lipids by surface-active detergents accelerates the transepidermal water loss and disturbs the barrier function of the epidermis and thus is intimately involved in the pathogenesis of atopic dermatitis. PMID:25648414

  1. A novel detergent-stable solvent-tolerant serine thiol alkaline protease from Streptomyces koyangensis TN650.

    PubMed

    Ben Elhoul, Mouna; Zaraî Jaouadi, Nadia; Rekik, Hatem; Bejar, Wacim; Boulkour Touioui, Souraya; Hmidi, Maher; Badis, Abdelmalek; Bejar, Samir; Jaouadi, Bassem

    2015-08-01

    An alkaline proteinase (STAP) was produced from strain TN650 isolated from a Tunisian off-shore oil field and assigned as Streptomyces koyangensis strain TN650 based on physiological and biochemical properties and 16S rRNA gene sequencing. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that the purified enzyme was a monomer with a molecular mass of 45125.17-Da. The enzyme had an NH2-terminal sequence of TQSNPPSWGLDRIDQTTAFTKACSIKY, thus sharing high homology with those of Streptomyces proteases. The results showed that this protease was completely inhibited by phenylmethanesulfonyl fluoride (PMSF), diiodopropyl fluorophosphates (DFP), and partially inhibited by 5,5-dithio-bis-(2-nitro benzoic acid) (DTNB), which strongly suggested its belonging to the serine thiol protease family. Using casein as a substrate, the optimum pH and temperature values for protease activity were pH 10 and 70 °C, respectively. The protease was stable at pH 7-10 and 30-60 °C for 24 h. STAP exhibited high catalytic efficiency, significant detergent stability, and elevated organic solvent resistance compared to the SG-XIV proteases from S. griseus and KERAB from Streptomyces sp. AB1. The stap gene encoding STAP was isolated, and its DNA sequence was determined. These properties make STAP a potential candidate for future application in detergent formulations and non-aqueous peptide biocatalysis.

  2. Effect of percentage of dietary forage neutral detergent fiber and source of starch on performance of lactating Jersey cows.

    PubMed

    Harmison, B; Eastridge, M L; Firkins, J L

    1997-05-01

    Five Jersey cows were used in a 5 x 5 Latin square design to determine the effects of decreasing dietary forage neutral detergent fiber (NDF) and different sources of dietary starch on performance and nutrient digestibilities. The control diet was balanced to consist of 21% forage NDF and 43% nonfiber carbohydrates. Four other diets were balanced to contain 35% nonfiber carbohydrates and either 16 or 11% forage NDF; diets were arranged in a 2 x 2 factorial design with either corn or corn and wheat as the sources of starch. Dry matter intake decreased linearly as forage NDF decreased; however, most of the decrease occurred when forage NDF was reduced from 16 to 11%. Milk production, yield of 4% fat-corrected milk, and percentages of milk fat and protein were similar among diets. Digestibility of NDF and acid detergent fiber increased as forage NDF decreased, but fiber digestibilities decreased with the addition of wheat to the diets. Starch digestibility was similar among diets. Source and amount of starch may be equally important or more important than the percentage of forage NDF for maintaining nutrient digestibilities of the total tract. Forage NDF in the diets of high producing cows can be reduced to 16% when sources and concentrations of starch are adequately balanced.

  3. Safer staining method for acid fast bacilli.

    PubMed Central

    Ellis, R C; Zabrowarny, L A

    1993-01-01

    To develop a method for staining acid fast bacilli which excluded highly toxic phenol from the staining solution. A lipophilic agent, a liquid organic detergent, LOC High Studs, distributed by Amway, was substituted. The acid fast bacilli stained red; nuclei, cytoplasm, and cytoplasmic elements stained blue on a clear background. These results compare very favourably with acid fast bacilli stained by the traditional method. Detergents are efficient lipophilic agents and safer to handle than phenol. The method described here stains acid fast bacilli as efficiently as traditional carbol fuchsin methods. LOC High Suds is considerably cheaper than phenol. Images PMID:7687254

  4. Safer staining method for acid fast bacilli.

    PubMed

    Ellis, R C; Zabrowarny, L A

    1993-06-01

    To develop a method for staining acid fast bacilli which excluded highly toxic phenol from the staining solution. A lipophilic agent, a liquid organic detergent, LOC High Studs, distributed by Amway, was substituted. The acid fast bacilli stained red; nuclei, cytoplasm, and cytoplasmic elements stained blue on a clear background. These results compare very favourably with acid fast bacilli stained by the traditional method. Detergents are efficient lipophilic agents and safer to handle than phenol. The method described here stains acid fast bacilli as efficiently as traditional carbol fuchsin methods. LOC High Suds is considerably cheaper than phenol.

  5. Low Cost Carbon Fibre for Automotive Applications Part 1: Low Cost Carbon Fibre Development

    SciTech Connect

    Warren, Charles David; Das, Sujit; Wheatley, Dr. Alan

    2014-01-01

    In pursuit of the goal to produce ultra-lightweight fuel efficient vehicles, there has been great excitement during the last few years about the potential for using carbon fibre reinforced composites in high volume applications. Currently, the greatest hurdle that inhibits wider implementation of carbon fibre composites in transportation is the high cost of carbon fibre when compared to other candidate materials. However, significant research is being conducted to develop lower cost, high volume technologies for producing carbon fibre. This chapter will highlight ongoing research in this area.

  6. Gauge factors of fibre Bragg grating strain sensors in different types of optical fibres

    NASA Astrophysics Data System (ADS)

    Jülich, Florian; Aulbach, Laura; Wilfert, Andre; Kratzer, Peter; Kuttler, Rolf; Roths, Johannes

    2013-09-01

    Gauge factors of fibre Bragg grating (FBG)-based strain sensors that had been inscribed into three different types of optical fibres, which differ in core diameters and doping concentrations, were determined at room temperature with high accuracy. Repeated measurements were carried out with several samples of each type of fibre to allow statistical evaluations. For each type, the gauge factors were measured in two configurations: when the bare fibres were glued on a specimen at the location of the FBG and when they were vertically suspended and not bonded to any structure at the location of the FBG. By combining the results of both configurations, the strain transfer ratio of the gluing process and the strain-optic coefficient, peff, of the different types of fibres were determined. The strain-optic coefficient was found to vary up to 1.5% for the different types of optical fibres. The strain transfer ratio was obtained to be close to unity (>99%), showing the high quality of the gluing technique employed. The investigations demonstrate that highly accurate strain sensing is possible with fibre-optic strain sensors. The results are important for the development of accurate and reliable attaching techniques for coated sensor fibres and fibre-optic sensor patches.

  7. Synchronously pumped picosecond all-fibre Raman laser based on phosphorus-doped silica fibre.

    PubMed

    Kobtsev, Sergey; Kukarin, Sergey; Kokhanovskiy, Alexey

    2015-07-13

    Reported for the first time is picosecond-range pulse generation in an all-fibre Raman laser based on P₂O₅-doped silica fibre. Employment of phosphor-silicate fibre made possible single-cascade spectral transformation of pumping pulses at 1084 nm into 270-ps long Raman laser pulses at 1270 nm. The highest observed fraction of the Stokes component radiation at 1270 nm in the total output of the Raman laser amounted to 30%. The identified optimal duration of the input pulses at which the amount of Stokes component radiation in a ~16-m long phosphorus-based Raman fibre converter reaches its maximum was 140-180 ps.

  8. Optical Fibre Pressure Sensors in Medical Applications

    PubMed Central

    Poeggel, Sven; Tosi, Daniele; Duraibabu, DineshBabu; Leen, Gabriel; McGrath, Deirdre; Lewis, Elfed

    2015-01-01

    This article is focused on reviewing the current state-of-the-art of optical fibre pressure sensors for medical applications. Optical fibres have inherent advantages due to their small size, immunity to electromagnetic interferences and their suitability for remote monitoring and multiplexing. The small dimensions of optical fibre-based pressure sensors, together with being lightweight and flexible, mean that they are minimally invasive for many medical applications and, thus, particularly suited to in vivo measurement. This means that the sensor can be placed directly inside a patient, e.g., for urodynamic and cardiovascular assessment. This paper presents an overview of the recent developments in optical fibre-based pressure measurements with particular reference to these application areas. PMID:26184228

  9. Compressive and Tensile Behaviours of PLLA Matrix Composites Reinforced with Randomly Dispersed Flax Fibres

    NASA Astrophysics Data System (ADS)

    Roussière, Fabrice; Baley, Christophe; Godard, Grégory; Burr, Dominique

    2012-04-01

    Nowadays, the ecological footprint of a material is becoming tremendously important. The Poly l-Lactide Acid (PLLA) matrix composites reinforced by randomly scattered flax fibres have mechanical properties similar to polyester/glass composites [1], lower environmental impacts and can be compost at the end of their lives. In this study, the mechanical characterization of biocomposites has been pushed further with the determination of the compressive and tensile properties. Furthermore, the mechanical properties of single flax fibres have been measured and implemented in a micro-mechanical estimation of the composite elastic modulus. Tensile and compressive stiffness determined by the mechanical analyses show very good correlations with the mathematical estimation.

  10. A flow cytometric screening test for detergent-resistant surface antigens in monocytes.

    PubMed

    Wolf, Zsuzsanna; Orsó, Evelyn; Werner, Tobias; Boettcher, Alfred; Schmitz, Gerd

    2006-03-01

    Rafts resemble cholesterol- and glycosphingolipid-enriched, liquid-ordered plasma membrane microdomains, showing resistance to nonionic detergents, and are involved in various cellular processes. In the present study, we have tested surface antigens on resting and lipopolysaccharide (LPS)-stimulated human peripheral blood monocytes for their detergent resistance (i.e. raft-association), by flow cytometry. Constitutive (CD14, CD32, CD55), or LPS-induced (CD81) raft-association, and detergent solubility (i.e. exclusion of rafts) (CD71) of monocyte antigens in the presence of 0.01% Triton X-100 are clearly demonstrated. Flow cytometric detergent insolubility is a powerful tool for rapid screening the raft-association of monocyte antigens in a whole-blood assay.

  11. Washing of Cloth Contaminated with Radionuclides Using A Detergent-Free Laundry System

    SciTech Connect

    Yim, S. P.; Ahn, B. G.; Lee, H. J.; Shon, J. S.; Chung, H.; Kim, K. J.; Kim, H. J.; Park, J. H.; Lee, W. S.

    2003-02-25

    In this study, we describe a new laundry system to wash clothes, including those contaminated with radionuclides, without using detergent. The main part of this system is electrolytic cell that consists of a cathode with a special coating of nickel, an anode of nickel, and a cation exchange membrane between the two electrodes. The electrolyte is supplied to the anode and the tap-water to the cathode. When an electricity of 5 volts and 25 amperes is applied to the electrodes, the processed water is produced from the cathode. This processed water containing no detergent was investigated experimentally with regard to its decontamination efficiency of radionuclides and detergency of soil as compared to the conventional washing using detergent. It was found that the processed water from this system has an ability to simultaneously remove radionuclides and soil from the cloth with good efficiency.

  12. Virulence, biochemistry, morphology and host-interacting properties of detergent-free cultured mycobacteria: An update.

    PubMed

    Leisching, G; Pietersen, R-D; Wiid, I; Baker, B

    2016-09-01

    The culturing of mycobacteria is a standard procedure that is consistent world-wide, with little variation in the growth media constituents, particularly those found in liquid and solid media. Before the 1940s however, the aggregating nature of mycobacteria as well as the characteristic slow growth-rate saw mycobacterial research delay considerably. Dubos and colleagues addressed both these issues and observed that a very small volume of Tween detergent was sufficient to greatly improve the culturing of mycobacteria. Over the years however, evidence of the unfavourable effects of this detergent on a number of morphological, biochemical, pathogenic and host-interacting properties of mycobacteria surfaced. For the first time we bring together literature, past and present to comprehensively review the mycobacterial properties which are, and are not affected by the use of this detergent. We also address other detergents and methods which may circumvent the need to include Tween compounds in mycobacterial culture media. PMID:27553410

  13. Structural carbohydrates in a plant biomass: correlations between the detergent fiber and dietary fiber methods.

    PubMed

    Godin, Bruno; Agneessens, Richard; Gerin, Patrick; Delcarte, Jérôme

    2014-06-18

    We compared the detergent fiber and dietary fiber methods to analyze the cellulose and hemicellulose contents of commelinid and non-commelinid magnoliophyta biomass. A good linear correlation was found between both methods. Compared to the more accurate dietary fiber method, the detergent fiber method overestimates the content of cellulose, whereas the detergent fiber method, as compared to the dietary fiber method, overestimates and underestimates the hemicellulose content in commelinid and non-commelinid magnoliophyta biomass, respectively. Because of the good linear correlations, conversion factors were determined to predict the cellulose, hemicellulose, and xylan contents to be expected from the dietary fiber method, on the basis of analyses made by the faster, cheaper, and more commonly practiced detergent fiber method. Nevertheless, the dietary fiber method offers the advantage of providing the detailed composition of the hemicelluloses (xylan, arabinan, hemicellulosic glucan, galactan, and mannan), and that is of interest for biorefining purposes.

  14. Fibre based integral field unit constructional techniques

    NASA Astrophysics Data System (ADS)

    Murray, Graham J.

    2006-06-01

    Presented here is a selected overview of constructional techniques and principles that have been developed and implemented at the University of Durham in the manufacture of successful fibre-based integral field units. The information contained herein is specifically intended to highlight the constructional methods that have been devised to assemble an efficient fibre bundle. Potential pitfalls that need to be considered when embarking upon such a deceptively simple instrument are also discussed.

  15. Fibre Bragg grating for flood embankment monitoring

    NASA Astrophysics Data System (ADS)

    Markowski, Konrad; Nevar, Stanislau; Dworzanski, Adam; Hackiewicz, Krzysztof; Jedrzejewski, Kazimierz

    2014-11-01

    In this article we present the preliminary studies for the flood embankment monitoring system based on the fibre Bragg gratings. The idea of the system is presented. The Bragg resonance shift is transformed to the change of the power detected by the standard InGaAs photodiode. The discrimination of the received power was executed by another fibre Bragg grating with different parameters. The project of the fully functional system is presented as well.

  16. Fibre-optic sensors in health care

    NASA Astrophysics Data System (ADS)

    Grazia Mignani, Anna; Baldini, Francesco

    1997-05-01

    Biomedical fibre-optic sensors are attractive for the measurement of physical, chemical and biochemical parameters and for spectral measurements directly performed on the patient. An overview of fibre-optic sensors for in vivo monitoring is given, with particular attention paid to the advantages that these sensors are able to offer in different application fields such as cardiovascular and intensive care, angiology, gastroenterology, ophthalmology, oncology, neurology, dermatology and dentistry.

  17. Use of sourdough lactobacilli and oat fibre to decrease the glycaemic index of white wheat bread.

    PubMed

    De Angelis, Maria; Rizzello, Carlo G; Alfonsi, Giuditta; Arnault, Philip; Cappelle, Stefan; Di Cagno, Raffaella; Gobbetti, Marco

    2007-12-01

    This work was aimed at decreasing the glycaemic index (GI) of white wheat bread. Breads made with wheat flour (WF) or wholemeal flour (WMF) and fermented with baker's yeast had similar values of resistant starch (RS; 1.4-1.7 %, starch basis). Sourdough Lactobacillus plantarum P1 and Lactobacillus brevis P2 favoured the highest formation of RS (approximately 5 %) when fermented with WF and WMF. The mixture (1:1) of WF and WMF (WF/WMF) was selected. The effect of dietary fibres, chemical or sourdough acidification on the hydrolysis index (HI) of WF/WMF bread was determined. Among fibres, only the addition of oat fibre (5 %) decreased the HI to 90.84 %. Lactic acid determined the lowest HI, and the effect was related to the decrease of pH. For the same decrease of pH, breads fermented with L. plantarum P1 and L. brevis P2 (sourdough WF/WMF) showed values of HI lower than chemical acidification. The glucose response and GI of WF bread or sourdough WF/WMF bread enriched with oat fibre was determined by using fifteen healthy volunteers. Anhydrous glucose was used as reference. The area under the glucose response curve and the value of GI (72 %) of WF bread were significantly (P < 0.05) higher than sourdough WF/WMF bread enriched with oat fibre (GI = 53.7 %). The decrease of GI of the sourdough WF/WMF bread may be due to both fibre content and decreased pH. Compared to WMF bread, sourdough WF/WMF bread, enriched with oat fibre, had higher specific volume, better cell crumb structure and more appreciated acidulous smell, taste and aroma.

  18. Effect of dietary fibres on small intestine histomorphology and lipid metabolism in young broiler chickens.

    PubMed

    Rahmatnejad, E; Saki, A A

    2016-08-01

    Two experiments were conducted to determine the influence of dietary fibres on small intestine histomorphology and lipid metabolism in broilers from 1 to 21 day of age. In experiment 1, diets containing insoluble [cellulose (CEL); 2% and 4%] or soluble [carboxymethyl cellulose (CMC); 2% and 4%] fibre were fed to broilers from day 1 to 21 post-hatch and ileal tissue was collected at day 21 of age for histological evaluation. In experiment 2, broilers diet was supplemented with 0%, 1% or 2% insoluble fibre (Arbocel) during day 7 to 21 post-hatch and plasma and liver lipid metabolism were evaluated at day 21. In experiment 1, inclusion of CMC reduced body weight gain (BWG) and feed intake (FI) and increased feed conversion ratio (FCR) compared with others. Intestinal histomorphology was unaffected by CEL, but CMC led to an increase in crypt depth (CD) and serosa thickness and a decrease in villus height (VH), villus width (VW), VH:CD ratio and villus surface area (VSA), rather than control and CEL groups. Treatment did not affect goblet cell type. Moreover, the CMC-fed birds had greater total goblet cell count (GCC) as compared with others. In experiment 2, fibre inclusion was associated with increases in BWG from 7 to 14 day of age and an improvement in FCR, whereas FI was not influenced by treatments. Inclusion of fibre in the diet decreased the weight of the abdominal fat and cholesterol concentrations of liver and plasma. No significant effects on fatty acid composition of liver lipid were observed by fibre supplementation. These findings suggest dietary fibre affects performance, intestinal histomorphology and lipid metabolism in young chicks, which may directly affect poultry feeding strategies.

  19. Effect of dietary fibres on small intestine histomorphology and lipid metabolism in young broiler chickens.

    PubMed

    Rahmatnejad, E; Saki, A A

    2016-08-01

    Two experiments were conducted to determine the influence of dietary fibres on small intestine histomorphology and lipid metabolism in broilers from 1 to 21 day of age. In experiment 1, diets containing insoluble [cellulose (CEL); 2% and 4%] or soluble [carboxymethyl cellulose (CMC); 2% and 4%] fibre were fed to broilers from day 1 to 21 post-hatch and ileal tissue was collected at day 21 of age for histological evaluation. In experiment 2, broilers diet was supplemented with 0%, 1% or 2% insoluble fibre (Arbocel) during day 7 to 21 post-hatch and plasma and liver lipid metabolism were evaluated at day 21. In experiment 1, inclusion of CMC reduced body weight gain (BWG) and feed intake (FI) and increased feed conversion ratio (FCR) compared with others. Intestinal histomorphology was unaffected by CEL, but CMC led to an increase in crypt depth (CD) and serosa thickness and a decrease in villus height (VH), villus width (VW), VH:CD ratio and villus surface area (VSA), rather than control and CEL groups. Treatment did not affect goblet cell type. Moreover, the CMC-fed birds had greater total goblet cell count (GCC) as compared with others. In experiment 2, fibre inclusion was associated with increases in BWG from 7 to 14 day of age and an improvement in FCR, whereas FI was not influenced by treatments. Inclusion of fibre in the diet decreased the weight of the abdominal fat and cholesterol concentrations of liver and plasma. No significant effects on fatty acid composition of liver lipid were observed by fibre supplementation. These findings suggest dietary fibre affects performance, intestinal histomorphology and lipid metabolism in young chicks, which may directly affect poultry feeding strategies. PMID:26667363

  20. Knowledge about dietary fibre: a fibre study framework.

    PubMed

    Guiné, Raquel P F; Ferreira, Manuela; Correia, Paula; Duarte, João; Leal, Marcela; Rumbak, Ivana; Barić, Irena C; Komes, Drazenka; Satalić, Zvonimir; Sarić, Marijana M; Tarcea, Monica; Fazakas, Zita; Jovanoska, Dijana; Vanevski, Dragoljub; Vittadini, Elena; Pellegrini, Nicoletta; Szűcs, Viktória; Harangozó, Júlia; El-Kenawy, Ayman; El-Shenawy, Omnia; Yalçın, Erkan; Kösemeci, Cem; Klava, Dace; Straumite, Evita

    2016-09-01

    The objective of this work was to study the degree of knowledge about dietary fibre (DF), as influenced by factors such as gender, level of education, living environment or country. For this, a descriptive cross-sectional study was undertaken on a non-probabilistic sample of 6010 participants from 10 countries in different continents (Europe, Africa and America). The results showed that the participants revealed on average a positive but still low global level of knowledge, which alerts for the need to take some actions to further inform the population about DF and its role as a component of a healthy diet. The results also indicated differences between genders, levels of education, living environments and countries. The highest level of knowledge was revealed by the participants from female gender, with higher education and living in urban areas. Concerning the country, the best informed were the participants from Romania, followed by those from Portugal and Turkey while the least informed were from Egypt. PMID:27263981

  1. Enhancing the radiation dose detection sensitivity of optical fibres.

    PubMed

    Bradley, D A; Mahdiraji, G Amouzad; Ghomeishi, M; Dermosesian, E; Adikan, F R M; Rashid, H A A; Maah, M J

    2015-06-01

    A method for improving the thermoluminescence (TL) yield of silica-based optical fibres is demonstrated. Using silica obtained from a single manufacturer, three forms of pure (undoped) fibre (capillary-, flat-, and photonic crystal fibre (PCF)) and two forms of Ge-doped fibre (capillary- and flat-fibre) were fabricated. The pure fibre samples were exposed to 6 and 21MeV electrons, the doped fibres to 6MV photons. The consistent observation of large TL yield enhancement is strongly suggestive of surface-strain defects generation. For 6MeV irradiations of flat-fibre and PCF, respective TL yields per unit mass of about 12.0 and 17.5 times that of the undoped capillary-fibre have been observed. Similarly, by making a Ge-doped capillary-fibre into flat-fibre, the TL response is found to increase by some 6.0 times. Thus, in addition to TL from the presence of a dopant, the increase in fused surface areas of flat-fibres and PCF is seen to be a further important source of TL. The glow-curves of the undoped fibres have been analysed by computational deconvolution. Trap centre energies have been estimated and compared for the various fibre samples. Two trap centre types observed in capillary-fibre are also observed in flat-fibre and PCF. An additional trap centre in flat-fibre and one further trap centre in PCF are observed when compared to capillary fibre. These elevated-energy trap centres are linked with strain-generated defects in the collapsed regions of the flat fibre and PCF.

  2. Dewatering of fibre suspensions by pressure filtration

    NASA Astrophysics Data System (ADS)

    Hewitt, Duncan R.; Paterson, Daniel T.; Balmforth, Neil J.; Martinez, D. Mark

    2016-06-01

    A theoretical and experimental study of dewatering of fibre suspensions by uniaxial compression is presented. Solutions of a one-dimensional model are discussed and asymptotic limits of fast and slow compression are explored. Particular focus is given to relatively rapid compression and to the corresponding development of spatial variations in the solidity and velocity profiles of the suspension. The results of complementary laboratory experiments are presented for nylon or cellulose fibres suspended in viscous fluid. The constitutive relationships for each suspension were measured independently. Measurements of the load for different fixed compression speeds, together with some direct measurements of the velocity profiles using particle tracking velocimetry, are compared with model predictions. The comparison is reasonable for nylon, but poor for cellulose fibres. An extension to the model, which allows for a strain-rate-dependent component in the network stress, is proposed, and is found to give a dramatic improvement in the model predictions for cellulose fibre suspensions. The reason for this improvement is attributed to the microstructure of cellulose fibres, which, unlike nylon fibres, are themselves porous.

  3. Criticality and isostaticity in fibre networks

    NASA Astrophysics Data System (ADS)

    Broedersz, Chase P.; Mao, Xiaoming; Lubensky, Tom C.; Mackintosh, Frederick C.

    2011-12-01

    Disordered fibre networks are the basis of many man-made and natural materials, including structural components of living cells and tissue. The mechanical stability of such networks relies on the bending resistance of the fibres, in contrast to rubbers, which are governed by entropic stretching of polymer segments. Although it is known that fibre networks exhibit collective bending deformations, a fundamental understanding of such deformations and their effects on network mechanics has remained elusive. Here we introduce a lattice-based model of fibrous networks with variable connectivity to elucidate the roles of single-fibre elasticity and network structure. These networks exhibit both a low-connectivity rigidity threshold governed by fibre-bending elasticity and a high-connectivity threshold governed by fibre-stretching elasticity. Whereas the former determines the true onset of network rigidity, we show that the latter exhibits rich zero-temperature critical behaviour, including a crossover between various mechanical regimes along with diverging strain fluctuations and a concomitant diverging correlation length.

  4. Fibre intake and prostate cancer risk.

    PubMed

    Pelucchi, Claudio; Talamini, Renato; Galeone, Carlotta; Negri, Eva; Franceschi, Silvia; Dal Maso, Luigino; Montella, Maurizio; Conti, Ettore; La Vecchia, Carlo

    2004-03-20

    Dietary fibre has been reported to protect from several neoplasms, but the issue remains controversial. No previous study considered in depth the topic of fibres and prostate cancer. A multicentre case-control study was conducted in Italy from 1991 to 2002, including 1,294 men with incident, histologically confirmed prostate cancer and 1,451 controls admitted to the same network of hospitals as cases with acute nonmalignant conditions. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were obtained after allowance for major identified confounding factors, including total energy intake. Compared to the lowest quintile, the OR of prostate cancer for the highest quintile of total fibre intake was 0.93 (95% CI 0.71-1.22). The risk was inversely related with soluble fibre (OR = 0.89, 95% CI 0.78-1.02, for a difference between 80th and 20th percentile), cellulose (OR = 0.88, 95% CI 0.78-1.01) and vegetable fibre (OR = 0.82, 95% CI 0.73-0.93). These relationships were consistent across strata of age, family history of prostate cancer, body mass index and education. Vegetable fibres appear, therefore, to have a favourable association with prostate cancer risk. PMID:14750181

  5. Economics Of Optical Fibre Transmission Systems

    NASA Astrophysics Data System (ADS)

    Murray, W. J.

    1983-08-01

    Optical fibre as a telecommunication transmission medium has become one of the most significant developments so far of the digital era. A major contributory factor to the availability of optical fibre transmission systems has been the outstanding progress in the technology of manufacturing high quality glass fibre having relatively low attenuation and broad bandwidths. This and other achievements has enabled manufacturers in the United Kingdom to develop a range of optical fibre cables and transmission equipment for operation over short and long distances at the CCITT recommended digital hierarchical rates of 2, 8, 34 and 140Mbit/s which have been adopted by British Telecom (BT) for modernisation to an all digital transmission network. These optical fibre systems are now becoming increasingly price and performance competitive with conventional technology in many parts of telecommunications networks. In the British Telecom (BT) network the 140Mbit/s optical fibre systems are now economically competitive with equivalent systems on coaxial cable and microwave radio. The economics of 8 and 34Mbit/s systems are not yet sufficiently attractive, compared with 2Mbit/s digital line systems on pair type copper cables, for large scale use in rural and local distribution networks and are presently only justified on cost in and around large cities. As system costs decrease large applications are predicted particularly in support of future high speed data, cable television and visual information services.

  6. Direct molecular evolution of detergent-stable G protein-coupled receptors using polymer encapsulated cells.

    PubMed

    Scott, Daniel J; Plückthun, Andreas

    2013-02-01

    G protein-coupled receptors (GPCRs) are the largest class of pharmaceutical protein targets, yet drug development is encumbered by a lack of information about their molecular structure and conformational dynamics. Most mechanistic and structural studies as well as in vitro drug screening with purified receptors require detergent solubilization of the GPCR, but typically, these proteins exhibit only low stability in detergent micelles. We have developed the first directed evolution method that allows the direct selection of GPCRs stable in a chosen detergent from libraries containing over 100 million individual variants. The crucial concept was to encapsulate single Escherichia coli cells of a library, each expressing a different GPCR variant, to form detergent-resistant, semipermeable nano-containers. Unlike naked cells, these containers are not dissolved by detergents, allowing us to solubilize the GPCR proteins in situ while maintaining an association with the protein's genetic information, a prerequisite for directed evolution. The pore size was controlled to permit GPCR ligands to permeate but the solubilized receptor to remain within the nanocapsules. Fluorescently labeled ligands were used to bind to those GPCR variants inside the nano-containers that remained active in the detergent tested. With the use of fluorescence-activated cell sorting, detergent-stable mutants derived from two different family A GPCRs could be identified, some with the highest stability reported in short-chain detergents. In principle, this method (named cellular high-throughput encapsulation, solubilization and screening) is not limited to engineering stabilized GPCRs but could be used to stabilize other proteins for biochemical and structural studies.

  7. Insight into the Structure of Light Harvesting Complex II and its Stabilization in Detergent Solution

    SciTech Connect

    Cardoso, Mateus B; Smolensky, Dmitriy; Heller, William T; O'Neill, Hugh Michael

    2009-01-01

    The structure of spinach light-harvesting complex II (LHC II), stabilized in a solution of the detergent n-octyl-{beta}-d-glucoside (BOG), was investigated by small-angle neutron scattering (SANS). Physicochemical characterization of the isolated complex indicated that it was pure (>95%) and also in its native trimeric state. SANS with contrast variation was used to investigate the properties of the protein-detergent complex at three different H{sub 2}O/D{sub 2}O contrast match points, enabling the scattering properties of the protein and detergent to be investigated independently. The topological shape of LHC II, determined using ab initio shape restoration methods from the SANS data at the contrast match point of BOG, was consistent with the X-ray crystallographic structure of LHC II (Liu et al. Nature 2004 428, 287-292). The interactions of the protein and detergent were investigated at the contrast match point for the protein and also in 100% D{sub 2}O. The data suggested that BOG micelle structure was altered by its interaction with LHC II, but large aggregate structures were not formed. Indirect Fourier transform analysis of the LHC II/BOG scattering curves showed that the increase in the maximum dimension of the protein-detergent complex was consistent with the presence of a monolayer of detergent surrounding the protein. A model of the LHC II/BOG complex was generated to interpret the measurements made in 100% D{sub 2}O. This model adequately reproduced the overall size of the LHC II/BOG complex, but demonstrated that the detergent does not have a highly regular shape that surrounds the hydrophobic periphery of LHC II. In addition to demonstrating that natively structured LHC II can be produced for functional characterization and for use in artificial solar energy applications, the analysis and modeling approaches described here can be used for characterizing detergent-associated {alpha}-helical transmembrane proteins.

  8. Mapping lipid and detergent molecules at the surface of membrane proteins.

    PubMed

    Cogdell, Richard J; Gardiner, Alastair T; Roszak, Aleksander W; Stončius, Sigitas; Kočovský, Pavel; Isaacs, Neil W

    2011-06-01

    Electron-density maps for the crystal structures of membrane proteins often show features suggesting binding of lipids and/or detergent molecules on the hydrophobic surface, but usually it is difficult to identify the bound molecules. In our studies, heavy-atom-labelled phospholipids and detergents have been used to unequivocally identify these binding sites at the surfaces of test membrane proteins, the reaction centres from Rhodobacter sphaeroides and Blastochloris viridis. The generality of this method is discussed in the present article.

  9. Intestinal degradation of dietary fibre in green beans--effects of microwave treatments.

    PubMed

    Svanberg, M; Suortti, T; Nyman, M

    1999-07-01

    Intestinal degradation of dietary fibre in blanched and microwaved green beans was studied by using a rat experimental model. Content and composition of dietary fibre as well as molecular weight distribution of water-soluble polysaccharides (WSP) were analysed. There was a solubilization and a shift towards lower Mw of mainly uronic acid-containing polysaccharides with repeated microwave treatment in the raw material. Thus, the apparent Mw of water-soluble polysaccharides decreased from approximately 1,550,000 to approximately 300,000. After the beans had been digested the Mw of the WSP was significantly reduced, to approximately 100,000, and the differences in Mw seen between various processed raw materials had been evened out. After fermentation the Mw of the WSP decreased further approximately 10 times. Fibre fermentability was high (approximately 90%) and similar for the various processed beans.

  10. Radiation effects of UHMW-PE fibre on gel fraction and mechanical properties

    NASA Astrophysics Data System (ADS)

    Zhao, Yanning; Wang, Mouhua; Tang, Zhongfeng; Wu, Guozhong

    2011-02-01

    The effect of gamma ray irradiation on ultra-high molecular weight polyethylene (UHMW-PE) fibre was investigated for the change of gel fraction, mechanical properties, and morphology of crystallites. In the case of irradiation in air, the oxidation was limited to the fibre surface where the gel fraction decreased by chain scission, and the depth of the oxidation area from the surface was estimated to be 2 μm. Tensile tests showed similar stress-strain curves for irradiation in vacuum or in air, but the elongation at break decreased more obviously for irradiation in air. The oxidation products, such as carboxylic acids, were detected by FTIR measurement. However, the DSC and XRD analyses indicated little change of crystallinity on irradiation in vacuum or in air. The oxidation was limited to a thin surface area on irradiation in air due to a low migration rate of the radicals trapped in the crystallite in the UHMW-PE fibre.

  11. Waste prevention in liquid detergent distribution: a comparison based on life cycle assessment.

    PubMed

    Nessi, Simone; Rigamonti, Lucia; Grosso, Mario

    2014-11-15

    The distribution of liquid detergents through self-dispensing systems has been adopted in some Italian retail stores over the last few years. By enabling the consumer to refill several times the same container, it is proposed as a less waste-generating and more environmentally friendly alternative to the traditional distribution with single-use plastic containers. For this reason, its implementation is encouraged by the national waste prevention programme recently adopted in Italy. In order to assess such claims, a life cycle assessment was carried out to evaluate whether detergent distribution through self-dispensing systems actually allows to achieve the expected reduction in waste generation and environmental impacts. The focus was on the distribution within the large-scale retail trade and on the categories of laundry detergents, fabric softeners and hand dishwashing detergents. For each of them, a set of baseline single-use scenarios were compared with two alternative waste prevention scenarios, where the detergent is distributed through self-dispensing systems. Beyond waste generation, also the Cumulative Energy Demand and thirteen midpoint-level potential impact indicators were calculated for the comparison. Results showed that a reduction in waste generation up to 98% can be achieved, depending on the category of detergent, on the baseline scenario of comparison and on the number of times the refillable container is used. A progressive reduction in the energy demand and in most of the potential impacts was also observed, starting from a minimum number of uses of the refillable container. PMID:25209251

  12. Death following the ingestion of detergent: an autopsy case with special regard to the histochemical findings.

    PubMed

    Kawamoto, Osamu; Ishikawa, Takaki; Oritani, Shigeki; Kuramoto, Yuko; Michiue, Tomomi; Maeda, Hitoshi

    2013-06-01

    We report an autopsy case of death due to accidental ingestion of a liquid laundry detergent with special regard to the histochemical findings. A female inpatient suffering from schizophrenia in a psychiatric institution, was found unconscious lying on the floor of her room, with a container of detergent nearby, and died despite intensive life-support measures. At autopsy, the stomach and duodenum contained whitish translucent foamy viscous fluid, and the mucous membranes, from the esophagus to the duodenum, had diffuse erosions with congestion and edema. There was otherwise no significant pathology other than signs of acute death and hemolysis. Toxicological investigations detected 1-methyl-4-prop-1-en-2-ylcyclohexene (detergent additive) in the gastric contents using headspace-gas chromatography/mass spectrometry, and a nonionic surfactant by a color identification test. Although these substances could not be detected in the blood, body fluid or viscera, histochemical examination using Oil red O demonstrated droplet-like staining in the pulmonary alveoli, suggesting aspiration of detergent, and similar staining in the vasculature of the lung, Kupffer cells of the liver, Bowman capsules of the kidney, and capillaries of the brain, suggesting the systemic effect of ingested/aspirated detergent. These findings were in keeping with death from ingestion of detergent and demonstrated the importance of preventing accidents such as this in healthcare facilities for elderly people.

  13. Detergent-associated Solution Conformations of Helical and Beta-barrel Membrane Proteins

    SciTech Connect

    Mo, Yiming; Lee, Byung-Kwon; Ankner, John Francis; Becker, Jeffrey Marvin; Heller, William T

    2008-01-01

    Membrane proteins present major challenges for structural biology. In particular, the production of suitable crystals for high-resolution structural determination continues to be a significant roadblock for developing an atomic-level understanding of these vital cellular systems. The use of detergents for extracting membrane proteins from the native membrane for either crystallization or reconstitution into model lipid membranes for further study is assumed to leave the protein with the proper fold with a belt of detergent encompassing the membrane-spanning segments of the structure. Small-angle X-ray scattering was used to probe the detergent-associated solution conformations of three membrane proteins, namely bacteriorhodopsin (BR), the Ste2p G-protein coupled receptor from Saccharomyces cerevisiae, and the Escherichia coli porin OmpF. The results demonstrate that, contrary to the traditional model of a detergent-associated membrane protein, the helical proteins BR and Ste2p are not in the expected, compact conformation and associated with detergent micelles, while the ?-barrel OmpF is indeed embedded in a disk-like micelle in a properly folded state. The comparison provided by the BR and Ste2p, both members of the 7TM family of helical membrane proteins, further suggests that the interhelical interactions between the transmembrane helices of the two proteins differ, such that BR, like other rhodopsins, can properly refold to crystallize, while Ste2p continues to prove resistant to crystallization from an initially detergent-associated state.

  14. Waste prevention in liquid detergent distribution: a comparison based on life cycle assessment.

    PubMed

    Nessi, Simone; Rigamonti, Lucia; Grosso, Mario

    2014-11-15

    The distribution of liquid detergents through self-dispensing systems has been adopted in some Italian retail stores over the last few years. By enabling the consumer to refill several times the same container, it is proposed as a less waste-generating and more environmentally friendly alternative to the traditional distribution with single-use plastic containers. For this reason, its implementation is encouraged by the national waste prevention programme recently adopted in Italy. In order to assess such claims, a life cycle assessment was carried out to evaluate whether detergent distribution through self-dispensing systems actually allows to achieve the expected reduction in waste generation and environmental impacts. The focus was on the distribution within the large-scale retail trade and on the categories of laundry detergents, fabric softeners and hand dishwashing detergents. For each of them, a set of baseline single-use scenarios were compared with two alternative waste prevention scenarios, where the detergent is distributed through self-dispensing systems. Beyond waste generation, also the Cumulative Energy Demand and thirteen midpoint-level potential impact indicators were calculated for the comparison. Results showed that a reduction in waste generation up to 98% can be achieved, depending on the category of detergent, on the baseline scenario of comparison and on the number of times the refillable container is used. A progressive reduction in the energy demand and in most of the potential impacts was also observed, starting from a minimum number of uses of the refillable container.

  15. Ecotoxicity evaluation of a liquid detergent using the automatic biotest ECOTOX.

    PubMed

    Azizullah, Azizullah; Richter, Peter; Ullah, Waheed; Ali, Imran; Häder, Donat-Peter

    2013-08-01

    Synthetic detergents are common pollutants reaching aquatic environments in different ways after usage at homes, institutions and industries. In this study a liquid detergent, used for dish washing, was evaluated for its toxicity during long- and short-term tests using the automatic biotest ECOTOX. Different parameters of Euglena gracilis like motility, swimming velocity, gravitactic orientation, cell compactness and cell growth were used as end points. In short-term experiments, the maximum adverse effects on motility, velocity, cell shape and gravitaxis were observed after 1 h of exposure. With further increase in exposure time to the detergent a slight recovery of these parameters was observed. In long-term experiments, the detergent caused severe disturbances to E. gracilis. Motility, cell growth and cell compactness (shape) with EC50 values of 0.064, 0.18 and 2.05 %, respectively, were found as the most sensitive parameters to detergent stress. There was a slight positive effect on gravitactic orientation at the lowest two concentrations; at higher concentrations of the detergent cells orientation was highly impaired giving EC50 values of 1.75 and 2.52 % for upward swimming and r-value, respectively.

  16. Identification and absolute quantification of enzymes in laundry detergents by liquid chromatography tandem mass spectrometry.

    PubMed

    Gaubert, Alexandra; Jeudy, Jérémy; Rougemont, Blandine; Bordes, Claire; Lemoine, Jérôme; Casabianca, Hervé; Salvador, Arnaud

    2016-07-01

    In a stricter legislative context, greener detergent formulations are developed. In this way, synthetic surfactants are frequently replaced by bio-sourced surfactants and/or used at lower concentrations in combination with enzymes. In this paper, a LC-MS/MS method was developed for the identification and quantification of enzymes in laundry detergents. Prior to the LC-MS/MS analyses, a specific sample preparation protocol was developed due to matrix complexity (high surfactant percentages). Then for each enzyme family mainly used in detergent formulations (protease, amylase, cellulase, and lipase), specific peptides were identified on a high resolution platform. A LC-MS/MS method was then developed in selected reaction monitoring (SRM) MS mode for the light and corresponding heavy peptides. The method was linear on the peptide concentration ranges 25-1000 ng/mL for protease, lipase, and cellulase; 50-1000 ng/mL for amylase; and 5-1000 ng/mL for cellulase in both water and laundry detergent matrices. The application of the developed analytical strategy to real commercial laundry detergents enabled enzyme identification and absolute quantification. For the first time, identification and absolute quantification of enzymes in laundry detergent was realized by LC-MS/MS in a single run. Graphical Abstract Identification and quantification of enzymes by LC-MS/MS.

  17. A robust method to screen detergents for membrane protein stabilization, revisited.

    PubMed

    Champeil, Philippe; Orlowski, Stéphane; Babin, Simon; Lund, Sten; le Maire, Marc; Møller, Jesper; Lenoir, Guillaume; Montigny, Cédric

    2016-10-15

    This report is a follow up of our previous paper (Lund, Orlowski, de Foresta, Champeil, le Maire and Møller (1989), J Biol Chem 264:4907-4915) showing that solubilization in detergent of a membrane protein may interfere with its long-term stability, and proposing a protocol to reveal the kinetics of such irreversible inactivation. We here clarify the fact that when various detergents are tested for their effects, special attention has of course to be paid to their critical micelle concentration. We also investigate the effects of a few more detergents, some of which have been recently advertised in the literature, and emphasize the role of lipids together with detergents. Among these detergents, lauryl maltose neopentyl glycol (LMNG) exerts a remarkable ability, even higher than that of β-dodecylmaltoside (DDM), to protect our test enzyme, the paradigmatic P-type ATPase SERCA1a from sarcoplasmic reticulum. Performing such experiments for one's favourite protein probably remains useful in pre-screening assays testing various detergents. PMID:27443956

  18. Responses of nerve fibres of the rat saphenous nerve neuroma to mechanical and chemical stimulation: an in vitro study

    PubMed Central

    Rivera, Luis; Gallar, Juana; Pozo, Miguel Angel; Belmonte, Carlos

    2000-01-01

    The response of neuroma nerve endings to different stimuli was studied in a saphenous nerve neuroma preparation in vitro. Electrical activity was recorded from 141 single fibres dissected of saphenous nerve. One-third (27 %) displayed spontaneous activity. Based on their response to mechanical and chemical stimuli, neuroma nerve fibres were classified as mechanosensory fibres (47.5 %), mechanically insensitive chemosensory fibres (17.0 %), polymodal nociceptor fibres (28.4 %) and unresponsive fibres (7.1 %). Mechanosensory and polymodal neuroma endings responded to von Frey hair stimulation either with a few impulses (phasic units) or a sustained discharge (tonic units). Polymodal units were additionally activated by at least one of the following stimuli: acidic solutions; a combination of bradykinin, prostaglandin E2, serotonin, substance P and histamine (all at 1 μM) plus 7 mm KCl (inflammatory soup); 600 mm NaCl and capsaicin. Low pH solutions increased the firing discharge of polymodal endings proportionally to the proton concentration. The ‘inflammatory soup’ evoked a firing response characterized by the absence of tachyphylaxis, which appeared when its components were applied separately. Both stimuli sensitized polymodal fibres to mechanical stimulation. Hypertonic NaCl (600 mm) and capsaicin (3.3 mm) induced a prolonged discharge that outlasted the stimulus duration. Mechanically insensitive chemosensory neuroma fibres exhibited responses to chemical stimuli analogous to polymodal fibres. They became mechanically sensitive after chemical stimulation. These findings show that neuroma nerve endings in the rat saphenous nerve neuroma in vitro are functionally heterogeneous and exhibit properties reminiscent of those in intact mechanosensory, polymodal and ‘silent’ nociceptor sensory afferents, including their sensitization by algesic chemicals. PMID:10970431

  19. Transcriptome dynamics during fibre development in contrasting genotypes of Gossypium hirsutum L.

    PubMed

    Nigam, Deepti; Kavita, Palacharla; Tripathi, Rajiv K; Ranjan, Alok; Goel, Ridhi; Asif, Mehar; Shukla, Alpika; Singh, Gunjita; Rana, Debashis; Sawant, Samir V

    2014-02-01

    Understanding the contribution of genetic background in fibre quality traits is important for the development of future cotton varieties with superior fibre quality. We used Affymetrix microarray (Santa Clara, CA) and Roche 454 GSFLX (Branford, CT) for comparative transcriptome analysis between two superior and three inferior genotypes at six fibre developmental stages. Microarray-based analysis of variance (ANOVA) for 89 microarrays encompassing five contrasting genotypes and six developmental stages suggests that the stages of the fibre development have a more pronounced effect on the differentially expressed genes (DEGs) than the genetic background of genotypes. Superior genotypes showed enriched activity of cell wall enzymes, such as pectin methyl esterase, at early elongation stage, enriched metabolic activities such as lipid, amino acid and ribosomal protein subunits at peak elongation, and prolonged combinatorial regulation of brassinosteroid and auxin at later stages. Our efforts on transcriptome sequencing were focused on changes in gene expression at 25 DPA. Transcriptome sequencing resulted in the generation of 475 658 and 429 408 high-quality reads from superior and inferior genotypes, respectively. A total of 24 609 novel transcripts were identified manually for Gossypium hirsutum with no hits in NCBI 'nr' database. Gene ontology analyses showed that the genes for ribosome biogenesis, protein transport and fatty acid biosynthesis were over-represented in superior genotype, whereas salt stress, abscisic acid stimuli and water deprivation leading to the increased proteolytic activity were more pronounced in inferior genotype. PMID:24119257

  20. Fat, fibre and cancer risk in African Americans and rural Africans.

    PubMed

    O'Keefe, Stephen J D; Li, Jia V; Lahti, Leo; Ou, Junhai; Carbonero, Franck; Mohammed, Khaled; Posma, Joram M; Kinross, James; Wahl, Elaine; Ruder, Elizabeth; Vipperla, Kishore; Naidoo, Vasudevan; Mtshali, Lungile; Tims, Sebastian; Puylaert, Philippe G B; DeLany, James; Krasinskas, Alyssa; Benefiel, Ann C; Kaseb, Hatem O; Newton, Keith; Nicholson, Jeremy K; de Vos, Willem M; Gaskins, H Rex; Zoetendal, Erwin G

    2015-04-28

    Rates of colon cancer are much higher in African Americans (65:100,000) than in rural South Africans (<5:100,000). The higher rates are associated with higher animal protein and fat, and lower fibre consumption, higher colonic secondary bile acids, lower colonic short-chain fatty acid quantities and higher mucosal proliferative biomarkers of cancer risk in otherwise healthy middle-aged volunteers. Here we investigate further the role of fat and fibre in this association. We performed 2-week food exchanges in subjects from the same populations, where African Americans were fed a high-fibre, low-fat African-style diet and rural Africans a high-fat, low-fibre western-style diet, under close supervision. In comparison with their usual diets, the food changes resulted in remarkable reciprocal changes in mucosal biomarkers of cancer risk and in aspects of the microbiota and metabolome known to affect cancer risk, best illustrated by increased saccharolytic fermentation and butyrogenesis, and suppressed secondary bile acid synthesis in the African Americans.