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Sample records for stem wax ester

  1. Identification of the Wax Ester Synthase/Acyl-Coenzyme A:Diacylglycerol Acyltransferase WSD1 Required for Stem Wax Ester Biosynthesis in Arabidopsis12[W][OA

    Science.gov (United States)

    Li, Fengling; Wu, Xuemin; Lam, Patricia; Bird, David; Zheng, Huanquan; Samuels, Lacey; Jetter, Reinhard; Kunst, Ljerka

    2008-01-01

    Wax esters are neutral lipids composed of aliphatic alcohols and acids, with both moieties usually long-chain (C16 and C18) or very-long-chain (C20 and longer) carbon structures. They have diverse biological functions in bacteria, insects, mammals, and terrestrial plants and are also important substrates for a variety of industrial applications. In plants, wax esters are mostly found in the cuticles coating the primary shoot surfaces, but they also accumulate to high concentrations in the seed oils of a few plant species, including jojoba (Simmondsia chinensis), a desert shrub that is the major commercial source of these compounds. Here, we report the identification and characterization of WSD1, a member of the bifunctional wax ester synthase/diacylglycerol acyltransferase gene family, which plays a key role in wax ester synthesis in Arabidopsis (Arabidopsis thaliana) stems, as first evidenced by severely reduced wax ester levels of in the stem wax of wsd1 mutants. In vitro assays using protein extracts from Escherichia coli expressing WSD1 showed that this enzyme has a high level of wax synthase activity and approximately 10-fold lower level of diacylglycerol acyltransferase activity. Expression of the WSD1 gene in Saccharomyces cerevisiae resulted in the accumulation of wax esters, but not triacylglycerol, indicating that WSD1 predominantly functions as a wax synthase. Analyses of WSD1 expression revealed that this gene is transcribed in flowers, top parts of stems, and leaves. Fully functional yellow fluorescent protein-tagged WSD1 protein was localized to the endoplasmic reticulum, demonstrating that biosynthesis of wax esters, the final products of the alcohol-forming pathway, occurs in this subcellular compartment. PMID:18621978

  2. Real-Time monitoring of intracellular wax ester metabolism

    Directory of Open Access Journals (Sweden)

    Karp Matti

    2011-09-01

    Full Text Available Abstract Background Wax esters are industrially relevant molecules exploited in several applications of oleochemistry and food industry. At the moment, the production processes mostly rely on chemical synthesis from rather expensive starting materials, and therefore solutions are sought from biotechnology. Bacterial wax esters are attractive alternatives, and especially the wax ester metabolism of Acinetobacter sp. has been extensively studied. However, the lack of suitable tools for rapid and simple monitoring of wax ester metabolism in vivo has partly restricted the screening and analyses of potential hosts and optimal conditions. Results Based on sensitive and specific detection of intracellular long-chain aldehydes, specific intermediates of wax ester synthesis, bacterial luciferase (LuxAB was exploited in studying the wax ester metabolism in Acinetobacter baylyi ADP1. Luminescence was detected in the cultivation of the strain producing wax esters, and the changes in signal levels could be linked to corresponding cell growth and wax ester synthesis phases. Conclusions The monitoring system showed correlation between wax ester synthesis pattern and luminescent signal. The system shows potential for real-time screening purposes and studies on bacterial wax esters, revealing new aspects to dynamics and role of wax ester metabolism in bacteria.

  3. Wax Ester Fermentation and Its Application for Biofuel Production.

    Science.gov (United States)

    Inui, Hiroshi; Ishikawa, Takahiro; Tamoi, Masahiro

    2017-01-01

    In Euglena cells under anaerobic conditions, paramylon, the storage polysaccharide, is promptly degraded and converted to wax esters. The wax esters synthesized are composed of saturated fatty acids and alcohols with chain lengths of 10-18, and the major constituents are myristic acid and myristyl alcohol. Since the anaerobic cells gain ATP through the conversion of paramylon to wax esters, the phenomenon is named "wax ester fermentation". The wax ester fermentation is quite unique in that the end products, i.e. wax esters, have relatively high molecular weights, are insoluble in water, and accumulate in the cells, in contrast to the common fermentation end products such as lactic acid and ethanol.A unique metabolic pathway involved in the wax ester fermentation is the mitochondrial fatty acid synthetic system. In this system, fatty acid are synthesized by the reversal of β-oxidation with an exception that trans-2-enoyl-CoA reductase functions instead of acyl-CoA dehydrogenase. Therefore, acetyl-CoA is directly used as a C2 donor in this fatty acid synthesis, and the conversion of acetyl-CoA to malonyl-CoA, which requires ATP, is not necessary. Consequently, the mitochondrial fatty acid synthetic system makes possible the net gain of ATP through the synthesis of wax esters from paramylon. In addition, acetyl-CoA is provided in the anaerobic cells from pyruvate by the action of a unique enzyme, oxygen sensitive pyruvate:NADP(+) oxidoreductase, instead of the common pyruvate dehydrogenase multienzyme complex.Wax esters produced by anaerobic Euglena are promising biofuels because myristic acid (C14:0) in contrast to other algal produced fatty acids, such as palmitic acid (C16:0) and stearic acid (C18:0), has a low freezing point making it suitable as a drop-in jet fuel. To improve wax ester production, the molecular mechanisms by which wax ester fermentation is regulated in response to aerobic and anaerobic conditions have been gradually elucidated by identifying

  4. Chemical and physical analyses of wax ester properties

    Directory of Open Access Journals (Sweden)

    Sejal Patel

    2001-05-01

    Full Text Available Wax esters are major constituents of the surface lipids in many terrestrial arthropods, but their study is complicated by their diversity. We developed a procedure for quantifying isomers in mixtures of straight-chain saturated and unsaturated wax esters having the same molecular weights, using single-ion monitoring of the total ion current data from gas chromatography-mass spectrometry. We examined the biological consequences of structural differences by measuring the melting temperatures, Tm, of >60 synthetic wax esters, containing 26-48 carbon atoms. Compounds containing saturated alcohol and acid moieties melted at 38-73°C. The main factor affecting Tm was the total chain length of the wax ester, but the placement of the ester bond also affected Tm. Insertion of a double bond into either the alcohol or acid moiety decreased Tm by ~30°C. Simple mixtures of wax esters with n-alkanes melted several °C lower than predicted from the melting points of the component lipids. Our results indicate that the wax esters of primary alcohols that are most typically found on the cuticle of terrestrial arthropods occur in a solid state under physiological conditions, thereby conferring greater waterproofing. Wax esters of secondary alcohols, which occur on melanopline grasshoppers, melted >60°C below primary esters of the same molecular weight and reduced Tm of the total surface lipids to environmental values.

  5. WAX ESTERS PRODUCTION BY ALCOHOLYSIS OF PALM OIL FRACTIONS

    OpenAIRE

    Erin Ryantin Gunawan; Dedy Suhendra

    2010-01-01

    The lipase synthesis of wax esters using palm oil fractions (palm oil and palm kernel oil) and long chain alcohol as substrates was carried out. The present work focuses on the synthesis of wax esters using Lipozyme. Five parameters such as reaction time, temperature, amount of enzyme, molar ratio of substrates and various organic solvents of the reaction system were investigated. The optimum yields were achieved at the reaction temperature of 40 - 50 °C for palm oil (PO) and 40 °C for palm k...

  6. Wax ester profiling of seed oil by nano-electrospray ionization tandem mass spectrometry

    Science.gov (United States)

    2013-01-01

    Background Wax esters are highly hydrophobic neutral lipids that are major constituents of the cutin and suberin layer. Moreover they have favorable properties as a commodity for industrial applications. Through transgenic expression of wax ester biosynthetic genes in oilseed crops, it is possible to achieve high level accumulation of defined wax ester compositions within the seed oil to provide a sustainable source for such high value lipids. The fatty alcohol moiety of the wax esters is formed from plant-endogenous acyl-CoAs by the action of fatty acyl reductases (FAR). In a second step the fatty alcohol is condensed with acyl-CoA by a wax synthase (WS) to form a wax ester. In order to evaluate the specificity of wax ester biosynthesis, analytical methods are needed that provide detailed wax ester profiles from complex lipid extracts. Results We present a direct infusion ESI-tandem MS method that allows the semi-quantitative determination of wax ester compositions from complex lipid mixtures covering 784 even chain molecular species. The definition of calibration prototype groups that combine wax esters according to their fragmentation behavior enables fast quantitative analysis by applying multiple reaction monitoring. This provides a tool to analyze wax layer composition or determine whether seeds accumulate a desired wax ester profile. Besides the profiling method, we provide general information on wax ester analysis by the systematic definition of wax ester prototypes according to their collision-induced dissociation spectra. We applied the developed method for wax ester profiling of the well characterized jojoba seed oil and compared the profile with wax ester-accumulating Arabidopsis thaliana expressing the wax ester biosynthetic genes MaFAR and ScWS. Conclusions We developed a fast profiling method for wax ester analysis on the molecular species level. This method is suitable to screen large numbers of transgenic plants as well as other wax ester samples

  7. Wax ester profiling of seed oil by nano-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Iven, Tim; Herrfurth, Cornelia; Hornung, Ellen; Heilmann, Mareike; Hofvander, Per; Stymne, Sten; Zhu, Li-Hua; Feussner, Ivo

    2013-07-06

    Wax esters are highly hydrophobic neutral lipids that are major constituents of the cutin and suberin layer. Moreover they have favorable properties as a commodity for industrial applications. Through transgenic expression of wax ester biosynthetic genes in oilseed crops, it is possible to achieve high level accumulation of defined wax ester compositions within the seed oil to provide a sustainable source for such high value lipids. The fatty alcohol moiety of the wax esters is formed from plant-endogenous acyl-CoAs by the action of fatty acyl reductases (FAR). In a second step the fatty alcohol is condensed with acyl-CoA by a wax synthase (WS) to form a wax ester. In order to evaluate the specificity of wax ester biosynthesis, analytical methods are needed that provide detailed wax ester profiles from complex lipid extracts. We present a direct infusion ESI-tandem MS method that allows the semi-quantitative determination of wax ester compositions from complex lipid mixtures covering 784 even chain molecular species. The definition of calibration prototype groups that combine wax esters according to their fragmentation behavior enables fast quantitative analysis by applying multiple reaction monitoring. This provides a tool to analyze wax layer composition or determine whether seeds accumulate a desired wax ester profile. Besides the profiling method, we provide general information on wax ester analysis by the systematic definition of wax ester prototypes according to their collision-induced dissociation spectra. We applied the developed method for wax ester profiling of the well characterized jojoba seed oil and compared the profile with wax ester-accumulating Arabidopsis thaliana expressing the wax ester biosynthetic genes MaFAR and ScWS. We developed a fast profiling method for wax ester analysis on the molecular species level. This method is suitable to screen large numbers of transgenic plants as well as other wax ester samples like cuticular lipid extracts to

  8. Wax esters of different compositions produced via engineering of leaf chloroplast metabolism in Nicotiana benthamiana.

    Science.gov (United States)

    Aslan, Selcuk; Sun, Chuanxin; Leonova, Svetlana; Dutta, Paresh; Dörmann, Peter; Domergue, Frédéric; Stymne, Sten; Hofvander, Per

    2014-09-01

    In a future bio-based economy, renewable sources for lipid compounds at attractive cost are needed for applications where today petrochemical derivatives are dominating. Wax esters and fatty alcohols provide diverse industrial uses, such as in lubricant and surfactant production. In this study, chloroplast metabolism was engineered to divert intermediates from de novo fatty acid biosynthesis to wax ester synthesis. To accomplish this, chloroplast targeted fatty acyl reductases (FAR) and wax ester synthases (WS) were transiently expressed in Nicotiana benthamiana leaves. Wax esters of different qualities and quantities were produced providing insights to the properties and interaction of the individual enzymes used. In particular, a phytyl ester synthase was found to be a premium candidate for medium chain wax ester synthesis. Catalytic activities of FAR and WS were also expressed as a fusion protein and determined functionally equivalent to the expression of individual enzymes for wax ester synthesis in chloroplasts. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Critical Involvement of Environmental Carbon Dioxide Fixation to Drive Wax Ester Fermentation in Euglena

    Science.gov (United States)

    Nishio, Kazuki; Nakazawa, Masami; Nakamoto, Masatoshi; Okazawa, Atsushi; Kanaya, Shigehiko; Arita, Masanori

    2016-01-01

    Accumulation profiles of wax esters in Euglena gracilis Z were studied under several environmental conditions. The highest amount of total wax esters accumulated under hypoxia in the dark, and C28 (myristyl-myristate, C14:0-C14:0) was prevalent among all conditions investigated. The wax ester production was almost completely suppressed under anoxia in the light, and supplying exogenous inorganic carbon sources restored wax ester fermentation, indicating the need for external carbon sources for the wax ester fermentation. 13C-labeling experiments revealed specific isotopic enrichment in the odd-numbered fatty acids derived from wax esters, indicating that the exogenously-supplied CO2 was incorporated into wax esters via the propionyl-CoA pathway through the reverse tricarboxylic acid (TCA) cycle. The addition of 3-mercaptopicolinic acid, a phosphoenolpyruvate carboxykinase (PEPCK) inhibitor, significantly affected the incorporation of 13C into citrate and malate as the biosynthetic intermediates of the odd-numbered fatty acids, suggesting the involvement of PEPCK reaction to drive wax ester fermentation. Additionally, the 13C-enrichment pattern of succinate suggested that the CO2 assimilation might proceed through alternative pathways in addition to the PEPCK reaction. The current results indicate that the mechanisms of anoxic CO2 assimilation are an important target to reinforce wax ester fermentation in Euglena. PMID:27669566

  10. Neutral Lipid Biosynthesis in Engineered Escherichia coli: Jojoba Oil-Like Wax Esters and Fatty Acid Butyl Esters

    OpenAIRE

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-01-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant E...

  11. Synthesis of oleyl oleate wax esters in Arabidopsis thaliana and Camelina sativa seed oil.

    Science.gov (United States)

    Iven, Tim; Hornung, Ellen; Heilmann, Mareike; Feussner, Ivo

    2016-01-01

    Seed oil composed of wax esters with long-chain monoenoic acyl moieties represents a high-value commodity for industry. Such plant-derived sperm oil-like liquid wax esters are biodegradable and can have excellent properties for lubrication. In addition, wax ester oil may represent a superior substrate for biodiesel production. In this study, we demonstrate that the low-input oil seed crop Camelina sativa can serve as a biotechnological platform for environmentally benign wax ester production. Two biosynthetic steps catalysed by a fatty alcohol-forming acyl-CoA reductase (FAR) and a wax ester synthase (WS) are sufficient to achieve wax ester accumulation from acyl-CoA substrates. To produce plant-derived sperm oil-like liquid wax esters, the WS from Mus musculus (MmWS) or Simmondsia chinensis (ScWS) were expressed in combination with the FAR from Mus musculus (MmFAR1) or Marinobacter aquaeolei (MaFAR) in seeds of Arabidopsis thaliana and Camelina sativa. The three analysed enzyme combinations Oleo3:mCherry:MmFAR1∆c/Oleo3:EYFP:MmWS, Oleo3:mCherry:MmFAR1∆c/ScWS and MaFAR/ScWS showed differences in the wax ester molecular species profiles and overall biosynthetic performance. By expressing MaFAR/ScWS in Arabidopsis or Camelina up to 59% or 21% of the seed oil TAGs were replaced by wax esters, respectively. This combination also yielded wax ester molecular species with highest content of monounsaturated acyl moieties. Expression of the enzyme combinations in the Arabidopsis fae1 fad2 mutant background high in oleic acid resulted in wax ester accumulation enriched in oleyl oleate (18:1/18:1 > 60%), suggesting that similar values may be obtained with a Camelina high oleic acid line. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  12. Establishing very long-chain fatty alcohol and wax ester biosynthesis in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Wenning, Leonie; Yu, Tao; David, Florian

    2017-01-01

    Wax esters (WEs) are neutral lipids and can be used for a broad range of commercial applications, including personal care products, lubricants, or coatings. They are synthesized by enzymatic reactions catalyzed by a fatty acyl reductase (FAR) and a wax ester synthase (WS). At present, commercially...

  13. Neutral lipid biosynthesis in engineered Escherichia coli: jojoba oil-like wax esters and fatty acid butyl esters.

    Science.gov (United States)

    Kalscheuer, Rainer; Stöveken, Tim; Luftmann, Heinrich; Malkus, Ursula; Reichelt, Rudolf; Steinbüchel, Alexander

    2006-02-01

    Wax esters are esters of long-chain fatty acids and long-chain fatty alcohols which are of considerable commercial importance and are produced on a scale of 3 million tons per year. The oil from the jojoba plant (Simmondsia chinensis) is the main biological source of wax esters. Although it has a multitude of potential applications, the use of jojoba oil is restricted, due to its high price. In this study, we describe the establishment of heterologous wax ester biosynthesis in a recombinant Escherichia coli strain by coexpression of a fatty alcohol-producing bifunctional acyl-coenzyme A reductase from the jojoba plant and a bacterial wax ester synthase from Acinetobacter baylyi strain ADP1, catalyzing the esterification of fatty alcohols and coenzyme A thioesters of fatty acids. In the presence of oleate, jojoba oil-like wax esters such as palmityl oleate, palmityl palmitoleate, and oleyl oleate were produced, amounting to up to ca. 1% of the cellular dry weight. In addition to wax esters, fatty acid butyl esters were unexpectedly observed in the presence of oleate. The latter could be attributed to solvent residues of 1-butanol present in the medium component, Bacto tryptone. Neutral lipids produced in recombinant E. coli were accumulated as intracytoplasmic inclusions, demonstrating that the formation and structural integrity of bacterial lipid bodies do not require specific structural proteins. This is the first report on substantial biosynthesis and accumulation of neutral lipids in E. coli, which might open new perspectives for the biotechnological production of cheap jojoba oil equivalents from inexpensive resources employing recombinant microorganisms.

  14. Wax ester composition influences the diapause patterns in the copepod Calanoides acutus

    Science.gov (United States)

    Pond, David W.; Tarling, Geraint A.; Ward, Peter; Mayor, Daniel J.

    2012-01-01

    Many calanoid copepods inhabiting high latitude environments overwinter at depth in the water column in a state of diapause and the large wax ester reserves that they contain are central to this process. Here we compare the abundance, depth distribution, lipid content and wax ester composition of individual CV Calanoides acutus collected from the Southern Ocean at depth horizons ranging from the surface to 1000 m. Abundances of CV C. acutus varied considerably between locations, ranging from 44 to 1256 m -2. Levels of total lipid in the copepods increased with depth at a rate of around 100 μg per 100 m depth between 200 and 1000 m. Fatty acid composition of the wax esters reflected that of the local prey community, with a spectrum of diatom to flagellate dominated profiles corresponding to different microplankton environments. Copepods with highest levels of total lipid also contained highest levels of the highly unsaturated diatom fatty acid biomarker 20:5(n-3), and occupied the deepest depths during diapause. In addition, unsaturation levels of both the fatty acid and fatty alcohol moieties of the wax esters in the copepods increased with depth. This has implications for the buoyancy of these organisms: higher unsaturation makes the lipid likely to change from liquid to solid state at overwintering depths, increasing their specific gravity. These findings emphasise functional role of n-3 fatty acids in the diapause life-phase of calanoid copepods and in particular the importance of fatty acids from diatoms for overwintering.

  15. Production of Oleic Acid Based Wax Ester Using Acidic Homogeneous Catalysts

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    Naowara Al-Arafi

    2012-01-01

    Full Text Available Four homogeneous acidic catalysts were tested for their ability to catalyze the esterification reaction of oleic acid and oleyl alcohol to produce oleyl oleate, a wax ester. Sulfuric acid showed relatively higher specific activity. Various reaction parameters were optimised to obtain high percentage yield of oleyl oleate. The optimum condition to produce oeyl oleate was reaction time; 5 h, temperture; 90°C, amount of sulforic acid 0.15 g and molar ratio of oleyl alcohol to oleic acid; 1:1. Percentage yield of wax ester obtained at these optimum reaction conditions was 93.88. Disappearance of carboxylic acid (C=O peak has confirmed by FTIR with appearance of ester (C=O peak at 1739 cm−1. 1H NMR spectra analyses confirmed the result of oleyl oleate with appearance of ester (-CH2OCOR at 4.02 ppm and also the 13C-NMR confirmed the result with appearance of ester (C=O peak at 173.2 ppm. The low-temperture behavior of compound synthesized was determined through its pour point (PP, viscosity index (VI and flash point (FP values. The results showed that oleyl oleate exhibited the most favorable low-temperture performance of PP, VI and FP with −31°C, 197.5 and 320°C respectively. This is due to increase of the molacular weight thus improve the low temperture property significantly.

  16. Production of wax esters via microbial oil synthesis from food industry waste and by-product streams.

    Science.gov (United States)

    Papadaki, Aikaterini; Mallouchos, Athanasios; Efthymiou, Maria-Nefeli; Gardeli, Chryssavgi; Kopsahelis, Nikolaos; Aguieiras, Erika C G; Freire, Denise M G; Papanikolaou, Seraphim; Koutinas, Apostolis A

    2017-12-01

    The production of wax esters using microbial oils was demonstrated in this study. Microbial oils produced from food waste and by-product streams by three oleaginous yeasts were converted into wax esters via enzymatic catalysis. Palm oil was initially used to evaluate the influence of temperature and enzyme activity on wax ester synthesis catalysed by Novozyme 435 and Lipozyme lipases using cetyl, oleyl and behenyl alcohols. The highest conversion yields (up to 79.6%) were achieved using 4U/g of Novozyme 435 at 70°C. Transesterification of microbial oils to behenyl and cetyl esters was achieved at conversion yields up to 87.3% and 69.1%, respectively. Novozyme 435 was efficiently reused for six and three cycles during palm esters and microbial esters synthesis, respectively. The physicochemical properties of microbial oil derived behenyl esters were comparable to natural waxes. Wax esters from microbial oils have potential applications in cosmetics, chemical and food industries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Identification of genes coding for putative wax ester synthase/diacylglycerol acyltransferase enzymes in terrestrial and marine environments

    OpenAIRE

    Lanfranconi, Mariana P.; Alvarez, Adri?n F; Alvarez, H?ctor M.

    2015-01-01

    Synthesis of neutral lipids such as triacylglycerols (TAG) and wax esters (WE) is catalyzed in bacteria by wax ester synthase/diacylglycerol acyltransferase enzymes (WS/DGAT). We investigated the diversity of genes encoding this enzyme in contrasting natural environments from Patagonia (Argentina). The content of petroleum hydrocarbons in samples collected from oil-producing areas was measured. PCR-based analysis covered WS/DGAT occurrence in marine sediments and soil. No product was obtained...

  18. New MALDI matrices based on lithium salts for the analysis of hydrocarbons and wax esters.

    Science.gov (United States)

    Horká, Petra; Vrkoslav, Vladimír; Hanus, Robert; Pecková, Karolina; Cvačka, Josef

    2014-07-01

    Lithium salts of organic aromatic acids (lithium benzoate, lithium salicylate, lithium vanillate, lithium 2,5-dimethoxybenzoate, lithium 2,5-dihydroxyterephthalate, lithium α-cyano-4-hydroxycinnamate and lithium sinapate) were synthesized and tested as potential matrices for the matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry analysis of hydrocarbons and wax esters. The analytes were desorbed using nitrogen laser (337.1 nm) and ionized via the attachment of a lithium cation, yielding [M + Li](+) adducts. The sample preparation and the experimental conditions were optimized for each matrix using stearyl behenate and n-triacontane standards. The performance of the new matrices in terms of signal intensity and reproducibility, the mass range occupied by matrix ions and the laser power threshold were studied and compared with a previously recommended lithium 2,5-dihydroxybenzoate matrix (LiDHB) (Cvačka and Svatoš, Rapid Commun. Mass Spectrom. 2003, 17, 2203). Several of the new matrices performed better than LiDHB. Lithium vanillate offered a 2-3 times and 7-9 times higher signal for wax esters and hydrocarbons, respectively. Also, the signal reproducibility improved substantially, making this matrix a suitable candidate for imaging applications. In addition, the diffuse reflectance spectra and solubility of the synthesized compounds were investigated and discussed with respect to the compound's ability to serve as MALDI matrices. The applicability of selected matrices was tested on natural samples of wax esters and hydrocarbons. Copyright © 2014 John Wiley & Sons, Ltd.

  19. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: optimization by response surface methodology.

    Science.gov (United States)

    Sellami, Mohamed; Aissa, Imen; Frikha, Fakher; Gargouri, Youssef; Miled, Nabil

    2011-06-17

    Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil) and vegetables (jojoba) which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50 °C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30 °C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h. Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters. © 2011 Sellami et al; licensee BioMed Central Ltd.

  20. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Gargouri Youssef

    2011-06-01

    Full Text Available Abstract Background Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil and vegetables (jojoba which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Results Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C, the enzyme concentration (33.34-300 IU/mL, the alcohol/palm stearin molar ratio (3-7 mol/mol and the substrate concentration (0.06-0.34 g/mL on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL a high conversion yield of 98.52% was reached within a reaction time of 2 h. Conclusions Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.

  1. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

    Science.gov (United States)

    2011-01-01

    Background Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil) and vegetables (jojoba) which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Results Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C), the enzyme concentration (33.34-300 IU/mL), the alcohol/palm stearin molar ratio (3-7 mol/mol) and the substrate concentration (0.06-0.34 g/mL) on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL) a high conversion yield of 98.52% was reached within a reaction time of 2 h. Conclusions Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters. PMID:21682865

  2. Alteration of Wax Ester Content and Composition in Euglena gracilis with Gene Silencing of 3-ketoacyl-CoA Thiolase Isozymes.

    Science.gov (United States)

    Nakazawa, Masami; Andoh, Hiroko; Koyama, Keiichiro; Watanabe, Yomi; Nakai, Takeo; Ueda, Mitsuhiro; Sakamoto, Tatsuji; Inui, Hiroshi; Nakano, Yoshihisa; Miyatake, Kazutaka

    2015-05-01

    Euglena gracilis produces wax ester under hypoxic and anaerobic culture conditions with a net synthesis of ATP. In wax ester fermentation, fatty acids are synthesized by reversing beta-oxidation in mitochondria. A major species of wax ester produced by E. gracilis is myristyl myristate (14:0-14:0Alc). Because of its shorter carbon chain length with saturated compounds, biodiesel produced from E. gracilis wax ester may have good cold flow properties with high oxidative stability. We reasoned that a slight metabolic modification would enable E. gracilis to produce a biofuel of ideal composition. In order to produce wax ester with shorter acyl chain length, we focused on isozymes of the enzyme 3-ketoacyl-CoA thiolase (KAT), a condensing enzyme of the mitochondrial fatty acid synthesis pathway in E. gracilis. We performed a gene silencing study of KAT isozymes in E. gracilis. Six KAT isozymes were identified in the E. gracilis EST database, and silencing any three of them (EgKAT1-3) altered the wax ester amount and composition. In particular, silencing EgKAT1 induced a significant compositional shift to shorter carbon chain lengths in wax ester. A model fuel mixture inferred from the composition of wax ester in EgKAT1-silenced cells showed a significant decrease in melting point compared to that of the control cells.

  3. Tailoring the composition of novel wax esters in the seeds of transgenic Camelina sativa through systematic metabolic engineering.

    Science.gov (United States)

    Ruiz-Lopez, Noemi; Broughton, Richard; Usher, Sarah; Salas, Joaquin J; Haslam, Richard P; Napier, Johnathan A; Beaudoin, Frédéric

    2017-07-01

    The functional characterization of wax biosynthetic enzymes in transgenic plants has opened the possibility of producing tailored wax esters (WEs) in the seeds of a suitable host crop. In this study, in addition to systematically evaluating a panel of WE biosynthetic activities, we have also modulated the acyl-CoA substrate pool, through the co-expression of acyl-ACP thioesterases, to direct the accumulation of medium-chain fatty acids. Using this combinatorial approach, we determined the additive contribution of both the varied acyl-CoA pool and biosynthetic enzyme substrate specificity to the accumulation of non-native WEs in the seeds of transgenic Camelina plants. A total of fourteen constructs were prepared containing selected FAR and WS genes in combination with an acyl-ACP thioesterase. All enzyme combinations led to the successful production of wax esters, of differing compositions. The impact of acyl-CoA thioesterase expression on wax ester accumulation varied depending on the substrate specificity of the WS. Hence, co-expression of acyl-ACP thioesterases with Marinobacter hydrocarbonoclasticus WS and Marinobacter aquaeolei FAR resulted in the production of WEs with reduced chain lengths, whereas the co-expression of the same acyl-ACP thioesterases in combination with Mus musculus WS and M. aquaeolei FAR had little impact on the overall final wax composition. This was despite substantial remodelling of the acyl-CoA pool, suggesting that these substrates were not efficiently incorporated into WEs. These results indicate that modification of the substrate pool requires careful selection of the WS and FAR activities for the successful high accumulation of these novel wax ester species in Camelina seeds. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  4. Establishing very long-chain fatty alcohol and wax ester biosynthesis in Saccharomyces cerevisiae.

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    Wenning, Leonie; Yu, Tao; David, Florian; Nielsen, Jens; Siewers, Verena

    2017-05-01

    Wax esters (WEs) are neutral lipids and can be used for a broad range of commercial applications, including personal care products, lubricants, or coatings. They are synthesized by enzymatic reactions catalyzed by a fatty acyl reductase (FAR) and a wax ester synthase (WS). At present, commercially used WEs are mainly isolated from Simmondsia chinensis (jojoba), but the high extraction costs and limited harvest areas constrain their use. The use of FARs in combination with different WSs to achieve a synthesis of jojoba-like WEs in bacteria and yeast has been reported previously, but the products were restricted to C28-C36 WEs. These rather short WEs make up only a very small percentage of the total WEs in natural jojoba oil. The synthesis of longer chain WEs (up to C44) in Saccharomyces cerevisiae has so far only been achieved after substrate feeding. Here we identified new routes for producing very long-chain fatty alcohols (VLCFOHs) up to a chain length of C22 by heterologous expression of a FAR derived from Apis mellifera (AmFAR1) or Marinobacter aquaeolei VT8 (Maqu_2220) in S. cerevisiae and achieved maximum yields of 3.22 ± 0.36 mg/g cell dry weight (CDW) and 7.84 ± 3.09 mg/g CDW, respectively, after 48 h. Moreover, we enabled the synthesis of jojoba-like WEs up to a chain length of C42, catalyzed by a combination of Maqu_2220 together with the WS from S. chinensis (SciWS) and the S. cerevisiae elongase Elo2p, with a maximum yield of 12.24 ± 3.35 mg/g CDW after 48 h. Biotechnol. Bioeng. 2017;114: 1025-1035. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Microbial biosynthesis of wax esters during desiccation: an adaptation for colonization of the earliest terrestrial environments?

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    Finkelstein, D. B.; Brassell, S. C.; Pratt, L. M.

    2008-12-01

    Biosynthesis of wax esters (WE) by prokaryotes in natural systems, notably bacteria from hot springs and marine phytoplankton, is poorly documented, primarily because saponification is a routine step in the analysis of microbial mat lipids. Use of this preparative procedure, critical for characterization of the diagnostic distributions of carboxylic acids in phospholipids, precludes recovery of intact WE. Examination of non-saponified lipids in emergent and desiccated mats with comparable microbial communities from the Warner Lake region, Oregon, reveals increases in the relative abundance (18.6 to 59.9μg/g Corg) and average chain length (C38 to C46) of WE in the latter, combined with assimilation of phytol and tocopherol moieties. Prokaryotes can accumulate WE as storage lipids in vitro, notably at elevated temperature or under nitrogen limiting conditions, but we propose that biosynthesis of long-chain WE that have a low solubility and are resistant to degradation/oxidation may represent an evolutionary strategy to survive desiccation in evaporative environments. Moreover, aeolian transport of desiccated mat-rip-ups between lake flats allows for migration of microbial communities within and between lake flats and basins during arid conditions. Subsequent rehydration within an alkaline environment would naturally saponify WE, and thereby regenerate alcohol and acid moieties that could serve as membrane lipids for the next viable microbial generation. The evolutionary cradle of WE was likely abiotic generation under hydrothermal conditions, which is consistent with the antiquity of the ester linkage necessitated by its integral role in the membranes of Eubacteria (though not Archaea) and in bacteriochlorophyll. The subsequent capability of microbes to biosynthesize WE may have facilitated their survival when nutrients were limiting, and production of long-chain WE (>C40) may represent a further critical evolutionary threshold that enabled their persistence through

  6. Identification of genes coding for putative wax ester synthase/diacylglycerol acyltransferase enzymes in terrestrial and marine environments.

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    Lanfranconi, Mariana P; Alvarez, Adrián F; Alvarez, Héctor M

    2015-12-01

    Synthesis of neutral lipids such as triacylglycerols (TAG) and wax esters (WE) is catalyzed in bacteria by wax ester synthase/diacylglycerol acyltransferase enzymes (WS/DGAT). We investigated the diversity of genes encoding this enzyme in contrasting natural environments from Patagonia (Argentina). The content of petroleum hydrocarbons in samples collected from oil-producing areas was measured. PCR-based analysis covered WS/DGAT occurrence in marine sediments and soil. No product was obtained in seawater samples. All clones retrieved from marine sediments affiliated with gammaproteobacterial sequences and within them, most phylotypes formed a unique cluster related to putative WS/DGAT belonging to marine OM60 clade. In contrast, soils samples contained phylotypes only related to actinomycetes. Among them, phylotypes affiliated with representatives largely or recently reported as oleaginous bacteria, as well as with others considered as possible lipid-accumulating bacteria based on the analysis of their annotated genomes. Our study shows for the first time that the environment could contain a higher variety of ws/dgat than that reported from bacterial isolates. The results of this study highlight the relevance of the environment in a natural process such as the synthesis and accumulation of neutral lipids. Particularly, both marine sediments and soil may serve as a useful source for novel WS/DGAT with biotechnological interest.

  7. Wax ester-like compounds as biosurfactants produced by Dietzia maris from n-alkane as a sole carbon source.

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    Nakano, Miyo; Kihara, Masaki; Iehata, Shunpei; Tanaka, Reiji; Maeda, Hiroto; Yoshikawa, Takeshi

    2011-10-01

    The hydrocarbon-degrading bacterium Dietzia maris WR-3 was isolated from a consortium comprising ammonia-oxidizing and denitrifying bacteria derived from marine sediments. Here, we examined biosurfactant production by strain WR-3 when cultured using several different carbon (D-glucose, n -decane, n -hexadecane, motor oil, olive oil, and rapeseed oil) and nitrogen (NH(4) )(2) SO(4) , NaNO(3) , yeast extract, and polypeptone) sources as growth substrates. Strain WR-3 was able to grow and reduce the surface tension of culture broth to 31±1.0 mN m(-1) when cultured using n -hexadecane and nitrate ions. The surface-active compounds produced by strain WR-3 were extracted and analyzed by thin layer chromatography. Moreover, the main components in the extract were further purified and subjected to gas chromatography/mass spectrometry (GC/MS). From the analysis, the surface-active compounds were tentatively identified as wax ester-like compounds, which were synthesized from the degradation process of n -alkane. The production of surface-active compounds by strain WR-3 promoted attachment of cells to hydrocarbon droplets via increased cell hydrophobicity, thus allowing enhanced degradation of water immiscible substrates. As Dietzia spp. can grow and produce wax esters from the degradation process of hydrocarbons, these marine bacteria are potentially useful for the bioremediation of hydrocarbon-contaminated environments. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Sequences of epicuticular wax structures along stems in four selected tree species

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    Tomaszewski Dominik

    2014-09-01

    Full Text Available Wax layer formation accompanies the processes of epidermis and cuticle formation. To examine these changes, observationsalong current-year long shoots of four woody species (Acer negundo, A. rufinerve, Gymnocladus dioica, and Gingko biloba were made. Long shoots are suitable objects for such observations, because from the same stem, several samples can be obtained that represent a well-defined sequence of fragments of different ages.

  9. Analysis of wax esters by silver-ion high-performance liquid chromatography-tandem mass spectrometry.

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    Vrkoslav, Vladimír; Urbanová, Klára; Háková, Matina; Cvačka, Josef

    2013-08-09

    Wax esters (WEs), esters of long-chain fatty acids and long-chain alcohols, were analysed by Ag-HPLC/APCI-MS/MS. Two ChromSpher Lipids columns connected in series (a total length of 50cm) and hexane-2-propanol-acetonitrile mobile phases were used to achieve good separation of the molecular species. The chromatographic behaviour of WEs was studied under optimised conditions: retention increased with the number of double bonds and with the temperature (15-35°C); retention times were affected by the double-bond position, trans isomers eluted earlier than cis isomers, and the WEs were partially separated depending on the aliphatic-chain length. The WEs provided simple APCI spectra with [M+H](+) ions, the MS/MS spectra showed fragments, which allowed their identification. The method was applied for an analysis of the WE mixtures from jojoba oil and human hair and the results were compared with analogous data from an optimised RP-HPLC system. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Analysis of wax ester molecular species by high performance liquid chromatography/atmospheric pressure chemical ionisation mass spectrometry.

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    Vrkoslav, Vladimír; Urbanová, Klára; Cvacka, Josef

    2010-06-18

    High chromatographic resolution of wax esters (WEs) was achieved by non-aqueous reversed-phase liquid chromatography on a Nova-Pak C18 column by optimising the acetonitrile/ethyl acetate mobile phase gradient. The retention behaviour of WEs was studied in this chromatographic system. The WEs eluted according to their equivalent carbon number (ECN) values; within the group of WEs with the identical ECN, the most unsaturated species tended to elute first. The isobaric WEs with different positions of the ester moiety were separated from each other whenever the lengths of the chains were sufficiently different. The methyl-branched esters eluted at shorter retention times than the straight-chained analogues, and the resolution among methyl-branched WEs depended on the position of the branching. The analytes were detected by atmospheric pressure chemical ionisation mass spectrometry (APCI-MS) using data-dependent scanning. WEs provided simple full-scan spectra with abundant protonated molecules and low-intensity fragments. Collision-induced dissociation (CID) promoted identification of the WE molecular species. The responses of WEs were found to be dependent on the number of double bonds and on the alkyl-chain length; the limits of the detection ranged from 20micromol/L to 200nmol/L. The HPLC/APCI-MS was applied for the analysis of the WEs isolated from honeycomb beeswax, jojoba oil and human hair. Good agreement between reported results and the literature data was achieved, with several novel polyunsaturated WEs also being found. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  11. High-yield preparation of wax esters via lipase-catalyzed esterification using fatty acids and alcohols from crambe and camelina oils.

    Science.gov (United States)

    Steinke, G; Weitkamp, P; Klein, E; Mukherjee, K D

    2001-02-01

    Fatty acids obtained from seed oils of crambe (Crambe abyssinica) and camelina (Camelina sativa) via alkaline saponification or steam splitting were esterified using lipases as biocatalysts with oleyl alcohol and the alcohols derived from crambe and camelina oils via hydrogenolysis of their methyl esters. Long-chain wax esters were thus obtained in high yields when Novozym 435 (immobilized lipase B from Candida antarctica) and papaya (Carica papaya) latex lipase were used as biocatalysts and vacuum was applied to remove the water formed. The highest conversions to wax esters were obtained with Novozym 435 (> or =95%) after 4-6 h of reaction, whereas with papaya latex lipase such a high degree of conversion was attained after 24 h. Products obtained from stoichiometric amounts of substrates were almost exclusively (>95%) composed of wax esters having compositions approaching that of jojoba (Simmondsia chinensis) oil, especially when crambe fatty acids in combination with camelina alcohols or camelina fatty acids in combination with crambe alcohols were used as substrates.

  12. Wax esters from the marine copepod Calanus finmarchicus reduce diet-induced obesity and obesity-related metabolic disorders in mice.

    Science.gov (United States)

    Höper, Anje C; Salma, Wahida; Sollie, Selene J; Hafstad, Anne D; Lund, Jim; Khalid, Ahmed M; Raa, Jan; Aasum, Ellen; Larsen, Terje S

    2014-02-01

    We showed previously that dietary supplementation with oil from the marine zooplankton Calanus finmarchicus (Calanus oil) attenuates obesity, inflammation, and glucose intolerance in mice. More than 80% of Calanus oil consists of wax esters, i.e., long-chain fatty alcohols linked to long-chain fatty acids. In the present study, we compared the metabolic effects of Calanus oil-derived wax esters (WE) with those of purified eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) ethyl esters (E/D) in a mouse model of diet-induced obesity. C57BL/6J mice received a high-fat diet (HFD; 45% energy from fat). After 7 wk, the diet was supplemented with either 1% (wt:wt) WE or 0.2% (wt:wt) E/D. The amount of EPA + DHA in the E/D diet was matched to the total amount of n-3 (ω-3) polyunsaturated fatty acids (PUFAs) in the WE diet. A third group was given an unsupplemented HFD throughout the entire 27-wk feeding period. WE reduced body weight gain, abdominal fat, and liver triacylglycerol by 21%, 34%, and 52%, respectively, and significantly improved glucose tolerance and aerobic capacity. In abdominal fat depots, WE reduced macrophage infiltration by 74% and downregulated expression of proinflammatory genes (tumor necrosis factor-α, interleukin-6, and monocyte chemoattractant protein-1), whereas adiponectin expression was significantly upregulated. By comparison, E/D primarily suppressed the expression of proinflammatory genes but had less influence on glucose tolerance than WE. E/D affected obesity parameters, aerobic capacity, or adiponectin expression by <10%. These results show that the wax ester component of Calanus oil can account for the biologic effects shown previously for the crude oil. However, these effects cannot exclusively be ascribed to the content of n-3 PUFAs in the wax ester fraction.

  13. Identification and Synthesis of Branched Wax-type Esters, Novel Surface Lipids from the Spider Argyrodes elevatus (Araneae: Theridiidae).

    Science.gov (United States)

    Chinta, Satya Prabhakar; Goller, Stephan; Uhl, Gabriele; Schulz, Stefan

    2016-09-01

    The analysis of cuticular extracts from the kleptoparasitic spider Argyrodes elevatus revealed the presence of unusual esters, new for arthropods. These novel compounds proved to be methyl-branched long-chain fatty acid esters with methyl branches located either close or remote from the internally located ester group. The GC/MS analysis of the prosoma lipid blend from the male cuticle contained one major component, undecyl 2-methyltridecanoate (1). In contrast, four major wax-type esters, 2-methylundecyl 2,8-dimethylundecanoate (2), 2,8-dimethylundecyl 2,8-dimethylundecanoate (3), heptadecyl 4-methylheptanoate (4), and 14-methylheptadecyl 4-methylheptanoate (5), were identified in the lipid blend of female prosomata. Structure assignments were based on mass spectra, gas chromatographic retention indices, and microderivatization. Unambiguous proof of postulated structures was ensured by an independent synthesis of all five esters. Preferentially, odd-numbered carbon chains pointed to a distinct biosynthetic pathway, different from that of common fatty acids, because one or two C3 starter units are incorporated during the biosynthesis of all acid and alcohol building blocks present in the five esters. The striking sexual dimorphism together with the unique biosynthesis points to a function of the esters in chemical communication of the spiders, although no behavioral data are currently available to test this assumption. © 2016 Wiley-VHCA AG, Zürich.

  14. Comparison of estimation capabilities of response surface methodology (RSM with artificial neural network (ANN in lipase-catalyzed synthesis of palm-based wax ester

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    Salleh Abu

    2007-08-01

    Full Text Available Abstract Background Wax esters are important ingredients in cosmetics, pharmaceuticals, lubricants and other chemical industries due to their excellent wetting property. Since the naturally occurring wax esters are expensive and scarce, these esters can be produced by enzymatic alcoholysis of vegetable oils. In an enzymatic reaction, study on modeling and optimization of the reaction system to increase the efficiency of the process is very important. The classical method of optimization involves varying one parameter at a time that ignores the combined interactions between physicochemical parameters. RSM is one of the most popular techniques used for optimization of chemical and biochemical processes and ANNs are powerful and flexible tools that are well suited to modeling biochemical processes. Results The coefficient of determination (R2 and absolute average deviation (AAD values between the actual and estimated responses were determined as 1 and 0.002844 for ANN training set, 0.994122 and 1.289405 for ANN test set, and 0.999619 and 0.0256 for RSM training set respectively. The predicted optimum condition was: reaction time 7.38 h, temperature 53.9°C, amount of enzyme 0.149 g, and substrate molar ratio 1:3.41. The actual experimental percentage yield was 84.6% at optimum condition, which compared well to the maximum predicted value by ANN (83.9% and RSM (85.4%. The order of effective parameters on wax ester percentage yield were; respectively, time with 33.69%, temperature with 30.68%, amount of enzyme with 18.78% and substrate molar ratio with 16.85%, whereas R2 and AAD were determined as 0.99998696 and 1.377 for ANN, and 0.99991515 and 3.131 for RSM respectively. Conclusion Though both models provided good quality predictions in this study, yet the ANN showed a clear superiority over RSM for both data fitting and estimation capabilities.

  15. Mitochondrial trans-2-enoyl-CoA reductase of wax ester fermentation from Euglena gracilis defines a new family of enzymes involved in lipid synthesis.

    Science.gov (United States)

    Hoffmeister, Meike; Piotrowski, Markus; Nowitzki, Ulrich; Martin, William

    2005-02-11

    Under anaerobiosis, Euglena gracilis mitochondria perform a malonyl-CoA independent synthesis of fatty acids leading to accumulation of wax esters, which serve as the sink for electrons stemming from glycolytic ATP synthesis and pyruvate oxidation. An important enzyme of this unusual pathway is trans-2-enoyl-CoA reductase (EC 1.3.1.44), which catalyzes reduction of enoyl-CoA to acyl-CoA. Trans-2-enoyl-CoA reductase from Euglena was purified 1700-fold to electrophoretic homogeneity and was active with NADH and NADPH as the electron donor. The active enzyme is a monomer with molecular mass of 44 kDa. The amino acid sequence of tryptic peptides determined by electrospray ionization mass spectrometry were used to clone the corresponding cDNA, which encoded a polypeptide that, when expressed in Escherichia coli and purified by affinity chromatography, possessed trans-2-enoyl-CoA reductase activity close to that of the enzyme purified from Euglena. Trans-2-enoyl-CoA reductase activity is present in mitochondria and the mRNA is expressed under aerobic and anaerobic conditions. Using NADH, the recombinant enzyme accepted crotonyl-CoA (km=68 microm) and trans-2-hexenoyl-CoA (km=91 microm). In the crotonyl-CoA-dependent reaction, both NADH (km=109 microm) or NADPH (km=119 microm) were accepted, with 2-3-fold higher specific activities for NADH relative to NADPH. Trans-2-enoyl-CoA reductase homologues were not found among other eukaryotes, but are present as hypothetical reading frames of unknown function in sequenced genomes of many proteobacteria and a few Gram-positive eubacteria, where they occasionally occur next to genes involved in fatty acid and polyketide biosynthesis. Trans-2-enoyl-CoA reductase assigns a biochemical activity, NAD(P)H-dependent acyl-CoA synthesis from enoyl-CoA, to one member of this gene family of previously unknown function.

  16. Genetic Characteristic of Dominant Ultra Short Stem and Wax Coating Absence for Winter Rye (Secale cereale L.

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    В. В. Скорик

    2010-10-01

    Full Text Available By means of directed hybridization and selection, a new donor of Winter Rye with combination of ultra short stem and absence of wax coating has been synthesized. Markings was offered for the first time for dominant genes of ultra short stem characteristic – HI-3HI-3, and for recessive genes of absence of wax coating characteristic – wcwc. Determination is made of genetic variability, coefficients of inheritance, phenotype and genotype correlation coefficients, on the basis of which a selection strategy by ten quantitative characteristics is proposed. Polypheny and cohesion effects were established. Under certain conception, strategy and tactic of improvement by breeding of Winter Rye characteristics, determination of genetic and statistic parameters between traits of parents and the offspring is required.

  17. Enhancement of photosynthetic capacity in Euglena gracilis by expression of cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase leads to increases in biomass and wax ester production.

    Science.gov (United States)

    Ogawa, Takahisa; Tamoi, Masahiro; Kimura, Ayako; Mine, Ayaka; Sakuyama, Harumi; Yoshida, Eriko; Maruta, Takanori; Suzuki, Kengo; Ishikawa, Takahiro; Shigeoka, Shigeru

    2015-01-01

    Microalgae have recently been attracting attention as a potential platform for the production of biofuels. Euglena gracilis, a unicellular phytoflagellate, has been proposed as an attractive feedstock to produce biodiesel because it can produce large amounts of wax esters, consisting of medium-chain fatty acids and alcohols with 14:0 carbon chains. E. gracilis cells highly accumulate a storage polysaccharide, a β-1,3-glucan known as paramylon, under aerobic conditions. When grown aerobically and then transferred into anaerobic conditions, E. gracilis cells degrade paramylon to actively synthesize and accumulate wax esters. Thus, the enhanced accumulation of paramylon through the genetic engineering of photosynthesis should increase the capacity for wax ester production. We herein generated transgenic Euglena (EpFS) cells expressing the cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase (FBP/SBPase), which is involved in the Calvin cycle, to enhance its photosynthetic activity. FBP/SBPase was successfully expressed within Euglena chloroplasts. The cell volume of the EpFS4 cell line was significantly larger than that of wild-type cells under normal growth conditions. The photosynthetic activity of EpFS4 cells was significantly higher than that of wild type under high light and high CO2, resulting in enhanced biomass production, and the accumulation of paramylon was increased in transgenic cell lines than in wild-type cells. Furthermore, when EpFS cell lines grown under high light and high CO2 were placed on anaerobiosis, the productivity of wax esters was approximately 13- to 100-fold higher in EpFS cell lines than in wild-type cells. Our results obtained here indicate that the efficiency of biomass production in E. gracilis can be improved by genetically modulating photosynthetic capacity, resulting in the enhanced production of wax esters. This is the first step toward the utilization of E. gracilis as a sustainable source for biofuel production under

  18. Localization of double bonds in wax esters by high-performance liquid chromatography/atmospheric pressure chemical ionization mass spectrometry utilizing the fragmentation of acetonitrile-related adducts.

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    Vrkoslav, Vladimír; Háková, Martina; Pecková, Karolina; Urbanová, Klára; Cvačka, Josef

    2011-04-15

    Unsaturated wax esters (WEs) provided molecular adducts with C(3)H(5)N ([M + 55](+•)) in APCI sources in the presence of acetonitrile. CID MS/MS of [M + 55](+•) yielded fragments allowing the localization of double bond(s) in the hydrocarbon chains of the WEs. These fragments were formed by a cleavage on each side of the double bond. In methylene-interrupted polyunsaturated WEs, diagnostic fragments related to each double bond were detected; the most abundant were those corresponding to the cleavage of the C-C bond next to the first and the last double bond. To differentiate between those fragments differing in their structure or origin, a simple nomenclature based on α and ω ions has been introduced. Fragmentation of the α-type ions (fragments containing an ester bond) provided information on the occurrence of a double bond in the acid or alcohol part of the WEs. While no significant differences between the spectra of the WEs differing by cis/trans isomerism were found, the isomers were separated chromatographically. A data-dependent HPLC/APCI-MS(2) method for the comprehensive characterization of WEs in their complex mixtures has been developed and applied to natural mixtures of WEs isolated from jojoba oil and beeswax. More than 50 WE molecular species were completely identified, including the information on the acid and alcohol chain length and the position of the double bonds. © 2011 American Chemical Society

  19. The cytochrome P450 enzyme CYP96A15 is the midchain alkane hydroxylase responsible for formation of secondary alcohols and ketones in stem cuticular wax of Arabidopsis.

    Science.gov (United States)

    Greer, Stephen; Wen, Miao; Bird, David; Wu, Xuemin; Samuels, Lacey; Kunst, Ljerka; Jetter, Reinhard

    2007-11-01

    Most aerial surfaces of plants are covered by cuticular wax that is synthesized in epidermal cells. The wax mixture on the inflorescence stems of Arabidopsis (Arabidopsis thaliana) is dominated by alkanes, secondary alcohols, and ketones, all thought to be formed sequentially in the decarbonylation pathway of wax biosynthesis. Here, we used a reverse-genetic approach to identify a cytochrome P450 enzyme (CYP96A15) involved in wax biosynthesis and characterized it as a midchain alkane hydroxylase (MAH1). Stem wax of T-DNA insertional mutant alleles was found to be devoid of secondary alcohols and ketones (mah1-1) or to contain much lower levels of these components (mah1-2 and mah1-3) than wild type. All mutant lines also had increased alkane amounts, partially or fully compensating for the loss of other compound classes. In spite of the chemical variation between mutant and wild-type waxes, there were no discernible differences in the epicuticular wax crystals on the stem surfaces. Mutant stem wax phenotypes could be partially rescued by expression of wild-type MAH1 under the control of the native promoter as well as the cauliflower mosaic virus 35S promoter. Cauliflower mosaic virus 35S-driven overexpression of MAH1 led to ectopic accumulation of secondary alcohols and ketones in Arabidopsis leaf wax, where only traces of these compounds are found in the wild type. The newly formed leaf alcohols and ketones had midchain functional groups on or next to the central carbon, thus matching those compounds in wild-type stem wax. Taken together, mutant analyses and ectopic expression of MAH1 in leaves suggest that this enzyme can catalyze the hydroxylation reaction leading from alkanes to secondary alcohols and possibly also a second hydroxylation leading to the corresponding ketones. MAH1 expression was largely restricted to the expanding regions of the inflorescence stems, specifically to the epidermal pavement cells, but not in trichomes and guard cells. MAH1-green

  20. SUPERKILLER Complex Components Are Required for the RNA Exosome-Mediated Control of Cuticular Wax Biosynthesis in Arabidopsis Inflorescence Stems1[OPEN

    Science.gov (United States)

    Zhao, Lifang; Kunst, Ljerka

    2016-01-01

    ECERIFERUM7 (CER7)/AtRRP45B core subunit of the exosome, the main cellular 3′-to-5′ exoribonuclease, is a positive regulator of cuticular wax biosynthesis in Arabidopsis (Arabidopsis thaliana) inflorescence stems. CER7-dependent exosome activity determines stem wax load by controlling transcript levels of the wax-related gene CER3. Characterization of the second-site suppressors of the cer7 mutant revealed that small interfering RNAs (siRNAs) are direct effectors of CER3 expression. To explore the relationship between the exosome and posttranscriptional gene silencing (PTGS) in regulating CER3 transcript levels, we investigated two additional suppressor mutants, wax restorer1 (war1) and war7. We show that WAR1 and WAR7 encode Arabidopsis SUPERKILLER3 (AtSKI3) and AtSKI2, respectively, components of the SKI complex that associates with the exosome during cytoplasmic 3′-to-5′ RNA degradation, and that CER7-dependent regulation of wax biosynthesis also requires participation of AtSKI8. Our study further reveals that it is the impairment of the exosome-mediated 3′-5′ decay of CER3 transcript in the cer7 mutant that triggers extensive production of siRNAs and efficient PTGS of CER3. This identifies PTGS as a general mechanism for eliminating highly abundant endogenous transcripts that is activated when 3′-to-5′ mRNA turnover by the exosome is disrupted. Diminished efficiency of PTGS in ski mutants compared with cer7, as evidenced by lower accumulation of CER3-related siRNAs, suggests that reduced amounts of CER3 transcript are available for siRNA synthesis, possibly because CER3 mRNA that does not interact with SKI is degraded by 5′-to-3′ XRN4 exoribonuclease. PMID:27208312

  1. RDR1 and SGS3, Components of RNA-Mediated Gene Silencing, Are Required for the Regulation of Cuticular Wax Biosynthesis in Developing Inflorescence Stems of Arabidopsis1[W][OA

    Science.gov (United States)

    Lam, Patricia; Zhao, Lifang; McFarlane, Heather E.; Aiga, Mytyl; Lam, Vivian; Hooker, Tanya S.; Kunst, Ljerka

    2012-01-01

    The cuticle is a protective layer that coats the primary aerial surfaces of land plants and mediates plant interactions with the environment. It is synthesized by epidermal cells and is composed of a cutin polyester matrix that is embedded and covered with cuticular waxes. Recently, we have discovered a novel regulatory mechanism of cuticular wax biosynthesis that involves the ECERIFERUM7 (CER7) ribonuclease, a core subunit of the exosome. We hypothesized that at the onset of wax production, the CER7 ribonuclease degrades an mRNA specifying a repressor of CER3, a wax biosynthetic gene whose protein product is required for wax formation via the decarbonylation pathway. In the absence of this repressor, CER3 is expressed, leading to wax production. To identify the putative repressor of CER3 and to unravel the mechanism of CER7-mediated regulation of wax production, we performed a screen for suppressors of the cer7 mutant. Our screen resulted in the isolation of components of the RNA-silencing machinery, RNA-DEPENDENT RNA POLYMERASE1 and SUPPRESSOR OF GENE SILENCING3, implicating RNA silencing in the control of cuticular wax deposition during inflorescence stem development in Arabidopsis (Arabidopsis thaliana). PMID:22689894

  2. Identification of avian wax synthases.

    Science.gov (United States)

    Biester, Eva-Maria; Hellenbrand, Janine; Gruber, Jens; Hamberg, Mats; Frentzen, Margrit

    2012-02-04

    Bird species show a high degree of variation in the composition of their preen gland waxes. For instance, galliform birds like chicken contain fatty acid esters of 2,3-alkanediols, while Anseriformes like goose or Strigiformes like barn owl contain wax monoesters in their preen gland secretions. The final biosynthetic step is catalyzed by wax synthases (WS) which have been identified in pro- and eukaryotic organisms. Sequence similarities enabled us to identify six cDNAs encoding putative wax synthesizing proteins in chicken and two from barn owl and goose. Expression studies in yeast under in vivo and in vitro conditions showed that three proteins from chicken performed WS activity while a sequence from chicken, goose and barn owl encoded a bifunctional enzyme catalyzing both wax ester and triacylglycerol synthesis. Mono- and bifunctional WS were found to differ in their substrate specificities especially with regard to branched-chain alcohols and acyl-CoA thioesters. According to the expression patterns of their transcripts and the properties of the enzymes, avian WS proteins might not be confined to preen glands. We provide direct evidence that avian preen glands possess both monofunctional and bifunctional WS proteins which have different expression patterns and WS activities with different substrate specificities.

  3. Identification of avian wax synthases

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    Biester Eva-Maria

    2012-02-01

    Full Text Available Abstract Background Bird species show a high degree of variation in the composition of their preen gland waxes. For instance, galliform birds like chicken contain fatty acid esters of 2,3-alkanediols, while Anseriformes like goose or Strigiformes like barn owl contain wax monoesters in their preen gland secretions. The final biosynthetic step is catalyzed by wax synthases (WS which have been identified in pro- and eukaryotic organisms. Results Sequence similarities enabled us to identify six cDNAs encoding putative wax synthesizing proteins in chicken and two from barn owl and goose. Expression studies in yeast under in vivo and in vitro conditions showed that three proteins from chicken performed WS activity while a sequence from chicken, goose and barn owl encoded a bifunctional enzyme catalyzing both wax ester and triacylglycerol synthesis. Mono- and bifunctional WS were found to differ in their substrate specificities especially with regard to branched-chain alcohols and acyl-CoA thioesters. According to the expression patterns of their transcripts and the properties of the enzymes, avian WS proteins might not be confined to preen glands. Conclusions We provide direct evidence that avian preen glands possess both monofunctional and bifunctional WS proteins which have different expression patterns and WS activities with different substrate specificities.

  4. Extracellular lipids of Camelina sativa: characterization of chloroform-extractable waxes from aerial and subterranean surfaces.

    Science.gov (United States)

    Razeq, Fakhria M; Kosma, Dylan K; Rowland, Owen; Molina, Isabel

    2014-10-01

    Camelina sativa (L.) Crantz is an emerging low input, stress tolerant crop with seed oil composition suitable for biofuel and bioproduct production. The chemical compositions and ultrastructural features of surface waxes from C. sativa aerial cuticles, seeds, and roots were analyzed using gas chromatography and microscopy. Alkanes, primary fatty alcohols, and free fatty acids were common components of all analyzed organs. A particular feature of leaf waxes was the presence of alkyl esters of long-chain fatty acids and very long-chain fatty alcohols, ranging from C38 to C50 and dominated by C42, C44 and C46 homologues. Stem waxes were mainly composed of non-sterol pentacyclic triterpenes. Flowers accumulated significant amounts of methyl-branched iso-alkanes (C29 and C31 total carbon number) in addition to straight-chain alkanes. Seed waxes were mostly primary fatty alcohols of up to 32 carbons in length and unbranched C29 and C31 alkanes. The total amount of identified wax components extracted by rapid chloroform dipping of roots was 280μgg(-1) (fresh weight), and included alkyl hydroxycinnamates, predominantly alkyl coumarates and alkyl caffeates. This study provides qualitative and quantitative information on the waxes of C. sativa root, shoot, and seed boundary tissues, allowing the relative activities of wax biosynthetic pathways in each respective plant organ to be assessed. This detailed description of the protective surface waxes of C. sativa may provide insights into its drought-tolerant and pathogen-resistant properties, and also identifies C. sativa as a potential source of renewable high-value natural products. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Long-chain aliphatic wax esters isolated from the sponge Chalinula saudensis (Demospongia along the Jeddah coast of the Red Sea

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    Abdulmohsin Al-Sofyani

    2011-03-01

    Full Text Available The sponge Chalinula saudensis, which occurs along the Jeddah coast, has only recently been isolated and identified. In this study, the total crude organic matter of the sponge was extracted by solvents. The total crude extract was further separated by partitioning it with hexane and water, then with water and chloroform, and finally with water and t-butanol. The chloroform layer was subjected to separation by preparative layer chromatography on silica. One fraction contained four long-chain fatty acid esters, C28H56O2, C30H60O2, C32H62O2 and C36H70 O2. The second ester, C30H60O2, has been identified in the fire corals Millepora dichotoma and Millepora platyphylla. The others have not previously been reported from marine organisms; however similar long-chain esters with different long aliphatic chains and with different molecular weights have been identified from other marine organisms. These compounds are normally waxy and their presence in Chalinula saudensis plays a vital role in the biosynthetic pathways. They also act as insulators against seasonal variations.A esponja Chalinula saudensis ocorre ao longo da costa de Jeddah, Arabia Saudita, mas apenas recentemente foi isolada e identificada. No presente estudo a matéria orgânica total da esponja foi extraída por solventes e o extrato foi separado por partição sucessiva através do emprego de hexano e água, clorofórmio e água e finalmente t-butanol e água. A camada contendo clorofórmio foi então separada por cromatografia em sílica. Os resultados mostraram a presença de ésteres de quatro ácidos graxos de cadeira longa (C28H56O2, C30H60O2, C32H62O2 e C36H70O2, sendo que o segundo deles foi também identificado nos corais Millepora dichotoma e Millepora platyphylla. Não se tem evidência da presença dos demais compostos em outros organismos marinhos, embora haja relatos para ésteres semelhantes de cadeia longa, mas contendo diferentes cadeias alifáticas e diferentes pesos

  6. Caffeic Acid Phenethyl Ester Regulates PPAR’s Levels in Stem Cells-Derived Adipocytes

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    Luca Vanella

    2016-01-01

    Full Text Available Hypertrophic obesity inhibits activation of peroxisome proliferators-activated receptor gamma (PPARγ, considered the key mediator of the fully differentiated and insulin sensitive adipocyte phenotype. We examined the effects of Caffeic Acid Phenethyl Ester (Cape, isolated from propolis, a honeybee hive product, on Adipose Stem Cells (ASCs differentiation to the adipocyte lineage. Finally we tested the effects of Cape on insulin-resistant adipocytes. Quantification of Oil Red O-stained cells showed that lipid droplets decreased following Cape treatment as well as radical oxygen species formation. Additionally, exposure of ASC to high glucose levels decreased adiponectin and increased proinflammatory cytokines mRNA levels, which were reversed by Cape-mediated increase of insulin sensitivity. Cape treatment resulted in decreased triglycerides synthesis and increased beta-oxidation. Exposure of ASCs to Lipopolysaccharide (LPS induced a reduction of PPARγ, an increase of IL-6 levels associated with a well-known stimulation of lipolysis; Cape partially attenuated the LPS-mediated effects. These observations reveal the main role of PPARγ in the adipocyte function and during ASC differentiation. As there is now substantial interest in functional food and nutraceutical products, the observed therapeutic value of Cape in insulin-resistance related diseases should be taken into consideration.

  7. Improvement of osteogenesis in dental pulp pluripotent-like stem cells by oligopeptide-modified poly(β-amino ester)s.

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    Núñez-Toldrà, Raquel; Dosta, Pere; Montori, Sheyla; Ramos, Víctor; Atari, Maher; Borrós, Salvador

    2017-04-15

    Controlling pluripotent stem cell differentiation via genetic manipulation is a promising technique in regenerative medicine. However, the lack of safe and efficient delivery vehicles limits this application. Recently, a new family of poly(β-amino ester)s (pBAEs) with oligopeptide-modified termini showing high transfection efficiency of both siRNA and DNA plasmid has been developed. In this study, oligopeptide-modified pBAEs were used to simultaneously deliver anti-OCT3/4 siRNA, anti-NANOG siRNA, and RUNX2 plasmid to cells from the dental pulp with pluripotent-like characteristics (DPPSC) in order to promote their osteogenic differentiation. Results indicate that transient inhibition of the pluripotency marker OCT3/4 and the overexpression of RUNX2 at day 7 of differentiation markedly increased and accelerated the expression of osteogenic markers. Furthermore, terminally-differentiated cells exhibited higher matrix mineralization and alkaline phosphatase activity. Finally, cell viability and genetic stability assays indicate that this co-delivery system has high chromosomal stability and minimal cytotoxicity. Therefore, we conclude that such co-delivery strategy is a safe and a quick option for the improvement of DPPSC osteogenic differentiation. Controlling pluripotent stem cell differentiation via genetic manipulation is a promising technique in regenerative medicine. However, the lack of safe and efficient delivery vehicles limits this application. In this study, we propose the use of a new family of oligopeptide-modified pBAEs developed in our group to control the differentiation of dental pulp pluripotential stem cells (DPPSC). In order to promote their osteogenic differentiation. The strategy proposed markedly increased and accelerated the expression of osteogenic markers, cell mineralization and alkaline phosphatase activity. Finally, cell viability and genetic stability assays indicated that this co-delivery system has high chromosomal stability and

  8. HOT WAX.

    Science.gov (United States)

    Schneberk, Todd; Valenzuela, Rolando G; Sterling, Garrett; Mallon, William K

    2015-09-01

    High-potency marijuana wax smoked via dabbing is a newly encountered phenomenon with relevance to prehospital care providers and emergency physicians.The extract is only recently described in current peer-reviewed literature. The drug may produce paranoia and psychosis and mimic psychiatric problems. The synthetic process for this drug poses a risk for both fire and explosions creating burns and blast injuries. These four cases were encountered in a single ED in Los Angeles in a three-week period, suggesting this could be the tip of an emerging public health problem. All four of these patients were complex cases requiring advanced imaging and ICU care. Emergency personnel need to appreciate this new trend and the implications for pre-hospital care, disposition and ED treatment of these patients.

  9. Detailed characterization of the substrate specificity of mouse wax synthase.

    Science.gov (United States)

    Miklaszewska, Magdalena; Kawiński, Adam; Banaś, Antoni

    2013-01-01

    Wax synthases are membrane-associated enzymes catalysing the esterification reaction between fatty acyl-CoA and a long chain fatty alcohol. In living organisms, wax esters function as storage materials or provide protection against harmful environmental influences. In industry, they are used as ingredients for the production of lubricants, pharmaceuticals, and cosmetics. Currently the biological sources of wax esters are limited to jojoba oil. In order to establish a large-scale production of desired wax esters in transgenic high-yielding oilseed plants, enzymes involved in wax esters synthesis from different biological resources should be characterized in detail taking into consideration their substrate specificity. Therefore, this study aims at determining the substrate specificity of one of such enzymes -- the mouse wax synthase. The gene encoding this enzyme was expressed heterologously in Saccharomyces cerevisiae. In the in vitro assays (using microsomal fraction from transgenic yeast), we evaluated the preferences of mouse wax synthase towards a set of combinations of 11 acyl-CoAs with 17 fatty alcohols. The highest activity was observed for 14:0-CoA, 12:0-CoA, and 16:0-CoA in combination with medium chain alcohols (up to 5.2, 3.4, and 3.3 nmol wax esters/min/mg microsomal protein, respectively). Unsaturated alcohols longer than 18°C were better utilized by the enzyme in comparison to the saturated ones. Combinations of all tested alcohols with 20:0-CoA, 22:1-CoA, or Ric-CoA were poorly utilized by the enzyme, and conjugated acyl-CoAs were not utilized at all. Apart from the wax synthase activity, mouse wax synthase also exhibited a very low acyl-CoA:diacylglycerol acyltransferase activity. However, it displayed neither acyl-CoA:monoacylglycerol acyltransferase, nor acyl-CoA:sterol acyltransferase activity.

  10. Hyaluronan Mixed Esters of Butyric and Retinoic Acid Affording Myocardial Survival and Repair without Stem Cell Transplantation*

    Science.gov (United States)

    Lionetti, Vincenzo; Cantoni, Silvia; Cavallini, Claudia; Bianchi, Francesca; Valente, Sabrina; Frascari, Irene; Olivi, Elena; Aquaro, Giovanni D.; Bonavita, Francesca; Scarlata, Ignazio; Maioli, Margherita; Vaccari, Valentina; Tassinari, Riccardo; Bartoli, Antonietta; Recchia, Fabio A.; Pasquinelli, Gianandrea; Ventura, Carlo

    2010-01-01

    Possible cardiac repair by adult stem cell transplantation is currently hampered by poor cell viability and delivery efficiency, uncertain differentiating fate in vivo, the needs of ex vivo cell expansion, and consequent delay in transplantation after the onset of heart attack. By the aid of magnetic resonance imaging, positron emission tomography, and immunohistochemistry, we show that injection of a hyaluronan mixed ester of butyric and retinoic acid (HBR) into infarcted rat hearts afforded substantial cardiovascular repair and recovery of myocardial performance. HBR restored cardiac [18F]fluorodeoxyglucose uptake and increased capillary density and led to the recruitment of endogenous Stro-1-positive stem cells. A terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay demonstrated that HBR-treated hearts exhibited a decrease in the number of apoptotic cardiomyocytes. In isolated rat cardiomyocytes and Stro-1 stem cells, HBR enhanced the transcription of vascular endothelial growth factor, hepatocyte growth factor, kdr, akt, and pim-1. HBR also increased the secretion of vascular endothelial growth factor and hepatocyte growth factor, suggesting that the mixed ester may have recruited both myocardial and Stro-1 cells also. An increase in capillarogenesis was induced in vitro with medium obtained from HBR-exposed cells. In the infarcted myocardium, HBR injection increased histone H4 acetylation significantly. Acetyl-H4 immunoreactivity increased in rat cardiomyocytes and Stro-1 cells exposed to HBR, compared with untreated cells. In conclusion, efficient cardiac regenerative therapy can be afforded by HBR without the need of stem cell transplantation or vector-mediated gene delivery. PMID:20097747

  11. Hyaluronan mixed esters of butyric and retinoic acid affording myocardial survival and repair without stem cell transplantation.

    Science.gov (United States)

    Lionetti, Vincenzo; Cantoni, Silvia; Cavallini, Claudia; Bianchi, Francesca; Valente, Sabrina; Frascari, Irene; Olivi, Elena; Aquaro, Giovanni D; Bonavita, Francesca; Scarlata, Ignazio; Maioli, Margherita; Vaccari, Valentina; Tassinari, Riccardo; Bartoli, Antonietta; Recchia, Fabio A; Pasquinelli, Gianandrea; Ventura, Carlo

    2010-03-26

    Possible cardiac repair by adult stem cell transplantation is currently hampered by poor cell viability and delivery efficiency, uncertain differentiating fate in vivo, the needs of ex vivo cell expansion, and consequent delay in transplantation after the onset of heart attack. By the aid of magnetic resonance imaging, positron emission tomography, and immunohistochemistry, we show that injection of a hyaluronan mixed ester of butyric and retinoic acid (HBR) into infarcted rat hearts afforded substantial cardiovascular repair and recovery of myocardial performance. HBR restored cardiac [(18)F]fluorodeoxyglucose uptake and increased capillary density and led to the recruitment of endogenous Stro-1-positive stem cells. A terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay demonstrated that HBR-treated hearts exhibited a decrease in the number of apoptotic cardiomyocytes. In isolated rat cardiomyocytes and Stro-1 stem cells, HBR enhanced the transcription of vascular endothelial growth factor, hepatocyte growth factor, kdr, akt, and pim-1. HBR also increased the secretion of vascular endothelial growth factor and hepatocyte growth factor, suggesting that the mixed ester may have recruited both myocardial and Stro-1 cells also. An increase in capillarogenesis was induced in vitro with medium obtained from HBR-exposed cells. In the infarcted myocardium, HBR injection increased histone H4 acetylation significantly. Acetyl-H4 immunoreactivity increased in rat cardiomyocytes and Stro-1 cells exposed to HBR, compared with untreated cells. In conclusion, efficient cardiac regenerative therapy can be afforded by HBR without the need of stem cell transplantation or vector-mediated gene delivery.

  12. Hyaluronan esters drive Smad gene expression and signaling enhancing cardiogenesis in mouse embryonic and human mesenchymal stem cells.

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    Margherita Maioli

    Full Text Available BACKGROUND: Development of molecules chemically modifying the expression of crucial orchestrator(s of stem cell commitment may have significant biomedical impact. We have recently developed hyaluronan mixed esters of butyric and retinoic acids (HBR, turning cardiovascular stem cell fate into a high-yield process. The HBR mechanism(s remain still largely undefined. METHODOLOGY/PRINCIPAL FINDINGS: We show that in both mouse embryonic stem (ES cells and human mesenchymal stem cells from fetal membranes of term placenta (FMhMSCs, HBR differentially affected the patterning of Smad proteins, one of the major conductors of stem cell cardiogenesis. Real-time RT-PCR and Western blot analyses revealed that in both cell types HBR enhanced gene and protein expression of Smad1,3, and 4, while down-regulating Smad7. HBR acted at the transcriptional level, as shown by nuclear run-off experiments in isolated nuclei. Immunofluorescence analysis indicated that HBR increased the fluorescent staining for Smad1,3, and 4, confirming that the transcriptional action of HBR encompassed the upregulation of the encoded Smad proteins. Chromatin immune precipitation and transcriptional analyses showed that HBR increased the transcription of the cardiogenic gene Nkx-2.5 through Smad4 binding to its own consensus Smad site. Treatment of mouse ES cells and FMhMSCs with HBR led to the concomitant overexpression of both Smad4 and α-sarcomeric actinin. Smad4 silencing by the aid of lentiviral-mediated Smad4 shRNA confirmed a dominant role of Smad4 in HBR-induced cardiogenesis. CONCLUSIONS/SIGNIFICANCE: The use of HBR may pave the way to novel combinatorial strategies of molecular and stem cell therapy based on fine tuning of targeted Smad transciption and signaling leading to a high-throughput of cardiogenesis without the needs of gene transfer technologies.

  13. Electrospun poly(ester-Urethane- and poly(ester-Urethane-Urea fleeces as promising tissue engineering scaffolds for adipose-derived stem cells.

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    Alfred Gugerell

    Full Text Available An irreversible loss of subcutaneous adipose tissue in patients after tumor removal or deep dermal burns makes soft tissue engineering one of the most important challenges in biomedical research. The ideal scaffold for adipose tissue engineering has yet not been identified though biodegradable polymers gained an increasing interest during the last years. In the present study we synthesized two novel biodegradable polymers, poly(ε-caprolactone-co-urethane-co-urea (PEUU and poly[(L-lactide-co-ε-caprolactone-co-(L-lysine ethyl ester diisocyanate-block-oligo(ethylene glycol-urethane] (PEU, containing different types of hydrolytically cleavable bondings. Solutions of the polymers at appropriate concentrations were used to fabricate fleeces by electrospinning. Ultrastructure, tensile properties, and degradation of the produced fleeces were evaluated. Adipose-derived stem cells (ASCs were seeded on fleeces and morphology, viability, proliferation and differentiation were assessed. The biomaterials show fine micro- and nanostructures composed of fibers with diameters of about 0.5 to 1.3 µm. PEUU fleeces were more elastic, which might be favourable in soft tissue engineering, and degraded significantly slower compared to PEU. ASCs were able to adhere, proliferate and differentiate on both scaffolds. Morphology of the cells was slightly better on PEUU than on PEU showing a more physiological appearance. ASCs differentiated into the adipogenic lineage. Gene analysis of differentiated ASCs showed typical expression of adipogenetic markers such as PPARgamma and FABP4. Based on these results, PEUU and PEU meshes show a promising potential as scaffold materials in adipose tissue engineering.

  14. Effect of solvent extraction on Tunisian esparto wax composition

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    Saâd Inès

    2016-08-01

    Full Text Available The increase of needs for renewable and vegetable based materials will help to drive the market growth of vegetable waxes. Because of their highly variable composition and physicochemical properties, plant waxes have found numerous applications in the: food, cosmetic, candle, coating, polish etc... The aim of this project is to determine the effect of solvent extraction (petroleum ether and ethanol on Tunisian esparto wax composition. The GC-MS was applied in order to determine the waxes compositions. Then, physicochemical parameters of these two samples of waxes: acid value, saponification value, iodine value and melting point were measured in order to deduct their properties and possible fields of uses. Results showed that esparto wax composition depended on the solvent extraction and that major components of the two samples of waxes were: alkanes, esters of fatty acids and phenols. Furthermore, esparto waxes were characterized by an antioxidant and antibacterial activities but the potential of these activities depended on the solvent of wax extraction.

  15. Analysis of the constituents in jojoba wax used as a food additive by LC/MS/MS.

    Science.gov (United States)

    Tada, Atsuko; Jin, Zhe-Long; Sugimoto, Naoki; Sato, Kyoko; Yamazaki, Takeshi; Tanamoto, Kenichi

    2005-10-01

    Jojoba wax is a natural gum base used as a food additive in Japan, and is obtained from jojoba oil with a characteristically high melting point. Although the constituents of jojoba oil have been reported, the quality of jojoba wax used as a food additive has not yet been clarified. In order to evaluate its quality as a food additive and to obtain basic information useful for setting official standards, we investigated the constituents and their concentrations in jojoba wax. LC/MS analysis of the jojoba wax showed six peaks with [M+H]+ ions in the range from m/z 533.6 to 673.7 at intervals of m/z 28. After isolation of the components of the four main peaks by preparative LC/MS, the fatty acid and long chain alcohol moieties of the wax esters were analyzed by methanolysis and hydrolysis, followed by GC/MS. The results indicated that the main constituents in jojoba wax were various kinds of wax esters, namely eicosenyl octadecenoate (C20:1-C18:1) (1), eicosenyl eicosenoate (C20:1-C20:1) (II), docosenyl eicosenoate (C22:1-C20:1) (III), eicosenyl docosenoate (C20:1-C22:1) (IV) and tetracosenyl eiosenoate (C24:1-C20:1) (V). To confirm and quantify the wax esters in jojoba wax directly, LC/MS/MS analysis was performed. The product ions corresponding to the fatty acid moieties of the wax esters were observed, and by using the product ions derived from the protonated molecular ions of wax esters the fatty acid moieties were identified by MRM analysis. The concentrations of the wax esters I, II and III, in jojoba wax were 5.5, 21.4 and 37.8%, respectively. In summary, we clarified the main constituents of jojoba wax and quantified the molecular species of the wax esters without hydrolysis by monitoring their product ions, using a LC/MS/MS system.

  16. Chemical composition of the epicuticular and intracuticular wax layers on adaxial sides of Rosa canina leaves.

    Science.gov (United States)

    Buschhaus, Christopher; Herz, Hubert; Jetter, Reinhard

    2007-12-01

    The waxy cuticle is the first point of contact for many herbivorous and pathogenic organisms on rose plants. Previous studies have reported the average composition of the combined wax extract from both sides of rose leaves. Recently, the compositions of the waxes on the adaxial and abaxial surfaces of Rosa canina leaves were determined separately. In this paper, a first report is made on the compositions of the epicuticular and intracuticular wax layers of Rosa canina leaves. The methods described enable the determination of which compounds are truly available at the surface for plant-organism interactions. An adhesive was used to mechanically strip the epicuticular wax from the adaxial leaf surface and the removal was visually confirmed using scanning electron microscopy. After the epicuticular wax had been removed, the intracuticular wax was then isolated using standard chemical extraction. Gas chromatography, flame ionization detection and mass spectrometry were used to identify and quantify compounds in the separated wax mixtures. The epicuticular wax contained higher concentrations of alkanes and alkyl esters but lower concentrations of primary alcohols and alkenols when compared to the intracuticular wax. In addition, the average chain lengths of these compound classes were higher in the epicuticular wax. Secondary alcohols were found only in the epicuticular layer while triterpenoids were restricted mainly to the intracuticular wax. A gradient exists between the composition of the epi- and intracuticular wax layers of Rosa canina leaves. This gradient may result from polarity differences, in part caused by differences in chain lengths. The outer wax layer accessible to the phyllosphere showed a unique composition of wax compounds. The ecological consequences from such a gradient may now be probed.

  17. Nanotubules on plant surfaces: chemical composition of epicuticular wax crystals on needles of Taxus baccata L.

    Science.gov (United States)

    Wen, Miao; Buschhaus, Christopher; Jetter, Reinhard

    2006-08-01

    Needles of Taxus baccata L. were covered with tubular epicuticular wax crystals varying in diameters (100 and 250 nm) and lengths (300-500 and 500-1000 nm) on the abaxial and adaxial surfaces, respectively. Various sampling protocols were employed to study the chemical composition of the needle waxes on three different levels of spatial resolution. First, a dipping extraction of whole needles yielded the total cuticular wax mixture consisting of very long chain fatty acids (21%), alkanediols (19%), phenyl esters (15%), and secondary alcohols (9%) together with small amounts of aldehydes, primary alcohols, alkanes, alkyl esters, and tocopherols. Second, waxes from both sides of the needle were sampled separately by brushing with CHCl3-soaked fabric glass. Both sides showed very similar qualitative composition, but differed drastically in quantitative aspects, with nonacosan-10-ol (18%) and alkanediols (33%) dominating the abaxial and adaxial waxes, respectively. Third, the epi- and intracuticular wax layers were selectively sampled by a combination of mechanical wax removal and brushing extraction. This provided direct evidence that the tubular wax crystals contained high percentages of nonacosane-4,10-diol and nonacosane-5,10-diol on the abaxial surface, and nonacosan-10-ol on the adaxial surface of the needles. Together with these compounds, relatively large amounts of fatty acids and smaller percentages of aldehydes, primary alcohols, alkyl esters, and alkanes co-crystallized in the epicuticular layer. In comparison, the intracuticular wax consisted of higher portions of cyclic constituents and aliphatics with relatively high polarity. The formation of the tubular crystals is discussed as a spontaneous physico-chemical process, involving the establishment of gradients between the epi- and intracuticular wax layers and local phase separation.

  18. Equisetum species show uniform epicuticular wax structures but diverse composition patterns.

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    Brune, Thomas; Haas, Klaus

    2011-01-01

    Only few data on the epicuticular waxes (EWs) of horsetails are available. This contribution therefore focuses on the wax micromorphology and chemical composition of Equisetum species of the subgenera Equisetum and Hippochaete. Distribution patterns and structural details of EW on the shoots were studied by scanning electron microscopy. After extraction with chloroform, the chemical composition of wax isolates was analysed by gas chromatography. Epicuticular wax crystals were non-oriented platelets or membraneous platelets. They were usually located on subsidiary cells of stomata and adjacent cells. Other parts of the shoots were covered mainly with a smooth wax film or small granules only. The chemical constituents found were alkanes, esters, aldehydes, primary alcohols and free fatty acids in a range of C(20)-C(36) (in esters C(36)-C(56)). All species of the subgenus Hippochaete showed a similar pattern of fractions with high percentages of alkanes and aldehydes, whereas the subgenus Equisetum species had distinctly different wax compositions. Extracts from the internodes-surfaces without well-developed EW crystals and only few stomata-showed the lowest contents of aldehydes. The covering with EW crystals will provide unhindered gas exchange and, combined with intracuticular wax, may prevent excess water loss during winter in the evergreen shoots of the subgenus Hippochaete. The results indicate that the Equisetum wax micromorphology and biosynthesis are comparable to EW of other pteridophyte classes and mosses.

  19. Effects of Nitric Oxide Production Inhibitor Named, NG-Nitro-L-Arginine Methyl Ester (L-NAME, on Rat Mesenchymal Stem Cells Differentiation

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    E Arfaei

    2010-04-01

    Full Text Available Introduction & Objectives: Recently, the findings of some studies have shown that, nitric oxide (NO probably has an important role in differentiation of mesenchymal stem cells to osteoblasts. The aim of the present investigation was to study the effects of nitric oxide production inhibitor named, NG-nitro-L-arginine methyl ester (L-NAME, on rat mesenchymal stem cells differentiation to osteoblasts in vitro. Materials & Methods: This was an experimental study conducted at Hamedan University of Medical Sciences in 2009, in which rat bone marrow stem cells were isolated in an aseptic condition and cultured in vitro. After third passage, the cells were cultured in osteogenic differentiation medium. To study the effects of L-NAME on osteogenic differentiation, the L-NAME was added to the culture medium at a concentration of 125, 250, and 500 μM in some culture plates. During the culture procedure, the media were replaced with fresh ones, with a three days interval. After 28 days of culturing the mineralized matrix was stained using Alizarian red staining method. The gathered data were analyzed by SPSS software version 12 using one way ANOVA. Results: The findings of this study showed that in the presence of L-NAME, differentiation of bone marrow mesenchymal stem cells to osteoblasts was disordered and matrix mineralization significantly decreased in a dose dependent manner. Conclusion: This study revealed that, inhibition of nitric oxide production using L-NAME can prevent the differentiation of rat bone marrow mesenchymal stem cells to osteoblast. The results imply that NO is an important constituent in differentiation of mesenchymal stem cell to osteoblasts.

  20. The structure and mechanism of stem bromelain. Evaluation of the homogeneity of purified stem bromelain, determination of the molecular weight and kinetic analysis of the bromelain-catalysed hydrolysis of N-benzyloxycarbonyl-l-phenylalanyl-l-serine methyl ester

    Science.gov (United States)

    Wharton, Christopher W.

    1974-01-01

    1. Purified stem bromelain (EC 3.4.22.4) was eluted from Sephadex G-100 as a single peak. The specific activity across the elution peak was approximately constant towards p-nitrophenyl hippurate but increased with elution volume with N2-benzoyl-l-arginine ethyl ester as substrate. 2. The apparent molecular weight, determined by elution analysis on Sephadex G-100, is 22500±1500, an anomalously low value. 3. Purified stem bromelain was eluted from CM-cellulose CM-32 as a single peak and behaved as a single species during column electrophoresis on Sephadex G-100. 4. Purified stem bromelain migrates as a single band during polyacrylamide-gel electrophoresis under a wide variety of conditions. 5. The molecular weight determined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate is 28500±1000. 6. Sedimentation-velocity and equilibrium-ultracentrifugation experiments, under a variety of conditions, indicate that bromelain is an apparently homogeneous single peptide chain of mol.wt. 28400±1400. 7. The N-terminal amino acid composition is 0.64±0.04mol of valine and 0.36±0.04mol of alanine per mol of enzyme of mol.wt. 28500. (The amino acid recovery of the cyanate N-terminal amino acid analysis was standardized by inclusion of carbamoyl-norleucine at the cyclization stage.) 8. The pH-dependence of the Michaelis parameters of the bromelain-catalysed hydrolysis of N-benzyloxycarbonyl-l-phenylalanyl-l-serine methyl ester was determined. 9. The magnitude and pH-dependence of the Michaelis parameters have been interpreted in terms of the mechanism of the enzyme. 10. The enzyme is able to bind N-benzyloxycarbonyl-l-phenylalanyl-l-serine methyl ester relatively strongly but seems unable to make use of the binding energy to promote catalysis. PMID:4462742

  1. Organogel formation of soybean oil with waxes

    Science.gov (United States)

    Many waxes including plant waxes and animal waxes were evaluated for the gelation ability toward soybean oil (SBO) and compared with hydrogenated vegetable oils, petroleum waxes and commercial non-edible gelling agents to understand factors affecting the gelation ability of a gelator. Sunflower wax...

  2. Waxed windshields are hazardous in the rain.

    Science.gov (United States)

    Allen, M J; Bennett, D W

    1975-08-01

    Seven automobiles were washed and waxed at four car washes. Photographic determinations were made of the glare produced by the wet or dry waxed windshield in a headlight beam. When wet, the waxed windshields scattered three times more light than in the normal human eye. The wet wax scattering was 24.8 times higher than when dry. No wax residues should be permitted on windshields and the National Highway Traffic Safety Administration should issue a mandatory windshield cleaning requirement after waxing.

  3. Identification of In-Chain-Functionalized Compounds and Methyl-Branched Alkanes in Cuticular Waxes of Triticum aestivum cv. Bethlehem.

    Science.gov (United States)

    Racovita, Radu C; Jetter, Reinhard

    2016-01-01

    In this work, cuticular waxes from flag leaf blades and peduncles of Triticum aestivum cv. Bethlehem were investigated in search for novel wax compounds. Seven wax compound classes were detected that had previously not been reported, and their structures were elucidated using gas chromatography-mass spectrometry of various derivatives. Six of the classes were identified as series of homologs differing by two methylene units, while the seventh was a homologous series with homologs with single methylene unit differences. In the waxes of flag leaf blades, secondary alcohols (predominantly C27 and C33), primary/secondary diols (predominantly C28) and esters of primary/secondary diols (predominantly C50, combining C28 diol with C22 acid) were found, all sharing similar secondary hydroxyl group positions at and around C-12 or ω-12. 7- and 8-hydroxy-2-alkanol esters (predominantly C35), 7- and 8-oxo-2-alkanol esters (predominantly C35), and 4-alkylbutan-4-olides (predominantly C28) were found both in flag leaf and peduncle wax mixtures. Finally, a series of even- and odd-numbered alkane homologs was identified in both leaf and peduncle waxes, with an internal methyl branch preferentially on C-11 and C-13 of homologs with even total carbon number and on C-12 of odd-numbered homologs. Biosynthetic pathways are suggested for all compounds, based on common structural features and matching chain length profiles with other wheat wax compound classes.

  4. Identification of In-Chain-Functionalized Compounds and Methyl-Branched Alkanes in Cuticular Waxes of Triticum aestivum cv. Bethlehem.

    Directory of Open Access Journals (Sweden)

    Radu C Racovita

    Full Text Available In this work, cuticular waxes from flag leaf blades and peduncles of Triticum aestivum cv. Bethlehem were investigated in search for novel wax compounds. Seven wax compound classes were detected that had previously not been reported, and their structures were elucidated using gas chromatography-mass spectrometry of various derivatives. Six of the classes were identified as series of homologs differing by two methylene units, while the seventh was a homologous series with homologs with single methylene unit differences. In the waxes of flag leaf blades, secondary alcohols (predominantly C27 and C33, primary/secondary diols (predominantly C28 and esters of primary/secondary diols (predominantly C50, combining C28 diol with C22 acid were found, all sharing similar secondary hydroxyl group positions at and around C-12 or ω-12. 7- and 8-hydroxy-2-alkanol esters (predominantly C35, 7- and 8-oxo-2-alkanol esters (predominantly C35, and 4-alkylbutan-4-olides (predominantly C28 were found both in flag leaf and peduncle wax mixtures. Finally, a series of even- and odd-numbered alkane homologs was identified in both leaf and peduncle waxes, with an internal methyl branch preferentially on C-11 and C-13 of homologs with even total carbon number and on C-12 of odd-numbered homologs. Biosynthetic pathways are suggested for all compounds, based on common structural features and matching chain length profiles with other wheat wax compound classes.

  5. Ester Formation

    OpenAIRE

    Lopez Garzon, C.S.; Straathof, A.J.J.

    2014-01-01

    The present invention is in the field of a process for producing an ester, such as a biobased ester, from an aqueous biomass comprising solution, batch wise or continuously, wherein use of raw material is limited and if possible re-used. The present invention is in the field of green technology.

  6. Waxes as organogelator for soybean oil

    Science.gov (United States)

    This research reveals that a small amount of a food grade plant wax may replace a large amount of the hardstock containing trans-fat or saturated fat. Natural waxes including plant waxes and animal waxes were evaluated for the gelation ability toward soybean oil (SBO) and compared with hydrogenated ...

  7. Structural identification of the diester preen gland wax in the Red Knot (Calidris canutus)

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Dekker, M.; Dongen, B.E. van; Schouten, S.; Piersma, T.

    2000-01-01

    The intact C32-C48 diester wax esters of the preen gland of the migrating bird Calidris canutus are shown, using synthesized standards, to comprise predominantly C12-C16 alkane-1,2-diols esterified with octanoic, decanoic, and dodecanoic acid at one position, and with predominantly even-numbered

  8. Physical characteristics of tetrahydroxy and acylated derivatives of jojoba liquid wax

    Science.gov (United States)

    Jojoba liquid wax is a mixture of esters of long chain fatty acids and fatty alcohols, mainly (C38:2-C46:2). The oil exhibits excellent emolliency on the skin and therefore is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the Jojoba (Simmondsia...

  9. Physical characteristics of tetrahydroxy and acylated derivatives of Jojoba liquid wax in lubricant applications

    Science.gov (United States)

    Jojoba liquid wax is a mixture of esters of long-chain fatty acids and fatty alcohols, mainly C38:2-C46:2. The oil exhibits excellent emolliency on the skin and, therefore, is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the jojoba (Simmondsia...

  10. Multiphase flow wax deposition modelling

    Energy Technology Data Exchange (ETDEWEB)

    Matzain, A. [Petronas Research and Scientific Services, Kuala Lumpur (Malaysia); Zhang, H.-Q.; Volk, M.; Redus, C.L.; Brill, J.P. [University of Tulsa (United States); Apte, M.S. [Shell Technology EP (United States); Creek, J.L. [Chevron Petroleum Technology (United States)

    2000-07-01

    Results are presented from two-phase flow wax deposition tests using a state-of-the-art, high pressure, multiphase flow test facility. Wax deposition was found to be flow pattern dependent and occurs only along the pipe wall in contact with the waxy crude oil. The deposition buildup trend at low mixture velocities is similar to that observed in laminar single-phase flow tests. The buildup trend at high mixture velocities is similar to that observed in turbulent single-phase flow tests. Thinner and harder deposits at the bottom than at the top of the pipe were observed in horizontal intermittent flow tests. Thicker and harder deposits were observed at low liquid superficial velocity than at high liquid superficial velocity annular flow tests. No wax deposition was observed along the upper portion of the pipe in stratified flow tests. A semi-empirical kinetic model tailored for the wax deposition tests predicted wax thickness with an acceptable accuracy, especially at high oil superficial velocity. Deposition rate reduction due to shear stripping and rate enhancement due to entrapment of oil and other mechanisms not accounted for by the classical Fick's mass diffusion theory were incorporated through the use of dimensionless variables and empirical constants derived from the wax deposition data. The kinetic model, although semi-empirical, provides an insight for future model development. (author)

  11. The effect of paraffin wax embedding procedures on the ability of the fluorescent antibody test to demonstrate bluetongue virus antigen in insect tissue.

    Science.gov (United States)

    Jennings, M; Boorman, J P

    1984-11-01

    The effect of the reagents used in paraffin wax embedding procedures on the fluorescent antibody technique was investigated with a view to using this test for virus location studies on paraffin wax sections of bluetongue virus infected Culicoides variipennis. Experiments were carried out using tissue smears rather than prepared sections, enabling the effect of individual reagents to be evaluated. Infected smears treated with acetone alone showed bright specific fluorescence, while treatment of infected smears with all other reagents, including low melting point wax and acetone-soluble ester wax, prior to immunofluorescence testing reduced the brightness of specific fluorescence or rendered the test completely ineffective.

  12. GC-MS Metabolomics to Evaluate the Composition of Plant Cuticular Waxes for Four Triticum aestivum Cultivars

    Directory of Open Access Journals (Sweden)

    Florent D. Lavergne

    2018-01-01

    Full Text Available Wheat (Triticum aestivum L. is an important food crop, and biotic and abiotic stresses significantly impact grain yield. Wheat leaf and stem surface waxes are associated with traits of biological importance, including stress resistance. Past studies have characterized the composition of wheat cuticular waxes, however protocols can be relatively low-throughput and narrow in the range of metabolites detected. Here, gas chromatography-mass spectrometry (GC-MS metabolomics methods were utilized to provide a comprehensive characterization of the chemical composition of cuticular waxes in wheat leaves and stems. Further, waxes from four wheat cultivars were assayed to evaluate the potential for GC-MS metabolomics to describe wax composition attributed to differences in wheat genotype. A total of 263 putative compounds were detected and included 58 wax compounds that can be classified (e.g., alkanes and fatty acids. Many of the detected wax metabolites have known associations to important biological functions. Principal component analysis and ANOVA were used to evaluate metabolite distribution, which was attributed to both tissue type (leaf, stem and cultivar differences. Leaves contained more primary alcohols than stems such as 6-methylheptacosan-1-ol and octacosan-1-ol. The metabolite data were validated using scanning electron microscopy of epicuticular wax crystals which detected wax tubules and platelets. Conan was the only cultivar to display alcohol-associated platelet-shaped crystals on its abaxial leaf surface. Taken together, application of GC-MS metabolomics enabled the characterization of cuticular wax content in wheat tissues and provided relative quantitative comparisons among sample types, thus contributing to the understanding of wax composition associated with important phenotypic traits in a major crop.

  13. Waxes in asphaltenes of crude oils and wax deposits

    Directory of Open Access Journals (Sweden)

    Yulia M. Ganeeva

    2016-07-01

    Full Text Available Abstract Composition and molecular mass distribution of n-alkanes in asphaltenes of crude oils of different ages and in wax deposits formed in the borehole equipment were studied. In asphaltenes, n-alkanes from C12 to C60 were detected. The high molecular weight paraffins in asphaltenes would form a crystalline phase with a melting point of 80–90 °C. The peculiarities of the redistribution of high molecular paraffin hydrocarbons between oil and the corresponding wax deposit were detected. In the oils, the high molecular weight paraffinic hydrocarbons C50–C60 were found, which were not practically detected in the corresponding wax deposits.

  14. Biochemical characterization and substrate specificity of jojoba fatty acyl-CoA reductase and jojoba wax synthase.

    Science.gov (United States)

    Miklaszewska, Magdalena; Banaś, Antoni

    2016-08-01

    Wax esters are used in industry for production of lubricants, pharmaceuticals and cosmetics. The only natural source of wax esters is jojoba oil. A much wider variety of industrial wax esters-containing oils can be generated through genetic engineering. Biotechnological production of tailor-made wax esters requires, however, a detailed substrate specificity of fatty acyl-CoA reductases (FAR) and wax synthases (WS), the two enzymes involved in wax esters synthesis. In this study we have successfully characterized the substrate specificity of jojoba FAR and jojoba WS. The genes encoding both enzymes were expressed heterologously in Saccharomyces cerevisiae and the activity of tested enzymes was confirmed by in vivo studies and in vitro assays using microsomal preparations from transgenic yeast. Jojoba FAR exhibited the highest in vitro activity toward 18:0-CoA followed by 20:1-CoA and 22:1-CoA. The activity toward other 11 tested acyl-CoAs was low or undetectable as with 18:2-CoA and 18:3-CoA. In assays characterizing jojoba WS combinations of 17 fatty alcohols with 14 acyl-CoAs were tested. The enzyme displayed the highest activity toward 14:0-CoA and 16:0-CoA in combination with C16-C20 alcohols as well as toward C18 acyl-CoAs in combination with C12-C16 alcohols. 20:1-CoA was efficiently utilized in combination with most of the tested alcohols. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  15. Purification of a jojoba embryo wax synthase, cloning of its cDNA, and production of high levels of wax in seeds of transgenic arabidopsis.

    Science.gov (United States)

    Lardizabal, K D; Metz, J G; Sakamoto, T; Hutton, W C; Pollard, M R; Lassner, M W

    2000-03-01

    Wax synthase (WS, fatty acyl-coenzyme A [coA]: fatty alcohol acyltransferase) catalyzes the final step in the synthesis of linear esters (waxes) that accumulate in seeds of jojoba (Simmondsia chinensis). We have characterized and partially purified this enzyme from developing jojoba embryos. A protein whose presence correlated with WS activity during chromatographic fractionation was identified and a cDNA encoding that protein was cloned. Seed-specific expression of the cDNA in transgenic Arabidopsis conferred high levels of WS activity on developing embryos from those plants. The WS sequence has significant homology with several Arabidopsis open reading frames of unknown function. Wax production in jojoba requires, in addition to WS, a fatty acyl-CoA reductase (FAR) and an efficient fatty acid elongase system that forms the substrates preferred by the FAR. We have expressed the jojoba WS cDNA in Arabidopsis in combination with cDNAs encoding the jojoba FAR and a beta-ketoacyl-CoA synthase (a component of fatty acid elongase) from Lunaria annua. (13)C-Nuclear magnetic resonance analysis of pooled whole seeds from transgenic plants indicated that as many as 49% of the oil molecules in the seeds were waxes. Gas chromatography analysis of transmethylated oil from individual seeds suggested that wax levels may represent up to 70% (by weight) of the oil present in those seeds.

  16. Comparative Analyses of Cuticular Waxes on Various Organs of Potato (Solanum tuberosum L.).

    Science.gov (United States)

    Guo, Yanjun; Jetter, Reinhard

    2017-05-17

    Complex mixtures of cuticular waxes coat plant surfaces to seal them against environmental stresses, with compositions greatly varying between species and possibly organs. This paper reports comprehensive analyses of the waxes on both above- and below-ground organs of potato, where total wax coverages varied between petals (2.6 μg/cm2), leaves, stems, and tubers (1.8-1.9 μg/cm2), and rhizomes (1.1 μg/cm2). The wax mixtures on above-ground organs were dominated by alkanes, occurring in homologous series of isomeric C25-C35 n-alkanes, C25-C35 2-methylalkanes, and C26-C34 3-methylalkanes. In contrast, below-ground organs had waxes rich in monoacylglycerols (C22-C28 acyls) and C18-C30 alkyl ferulates, together with fatty acids (rhizomes) or primary alcohols (tubers). The organ-specific wax coverages, compound class distribution, and chain length profiles suggest highly regulated activities of wax biosynthesis enzymes, likely related to organ-specific ecophysiological functions.

  17. Leaf-surface wax extracted from different pines as green additives exhibiting excellent tribological properties

    Science.gov (United States)

    Feng, Xin; Cao, Zhengfeng; Xia, Yanqiu

    2017-11-01

    Given the increasing attention on the topic of the ‘Green chemical’, it is imperative to explore new environmental friendly and biodegradable lubricants to meet the tribological performances and environmental needs. In this work, three types of leaf-surface wax were extracted from different pines as green lubricant additives and their chemical compositions, friction reduction and anti-wear abilities were investigated in detail. The results show that the leaf-surface wax extracted from different pines as additives in synthetic ester exhibit superior friction reduction and anti-wear abilities for steel/steel and steel/aluminum pairs. Based on the scanning electron microscopy and time-of-flight secondary ion mass spectroscopy analysis, the preferable tribological performances are ascribed to the physical adsorption film and tribo-chemical reaction film generated by the leaf-surface wax on the worn surfaces during the sliding process.

  18. Insecticidal Properties of a Highly Potent Wax Isolated from Dolichandra cynanchoides Cham

    Directory of Open Access Journals (Sweden)

    Georgina Díaz Napal

    2016-08-01

    Full Text Available Bioassay-guided fractionation of an ethanolic extract of the aerial parts of Dolichandra cynanchoides Cham. (Bignoniaceae led to the isolation of a natural wax with anti-insect activity against Spodoptera frugiperda (Noctuidae and Epilachna paenulata (Coleptera. The compound was identified spectroscopically as an ester of a C27 fatty acid and a C25 alcohol, pentacosyl heptacosanoate (1. The effective doses of 1 for 50% feeding inhibition (ED50 of S. frugiperda and E. paenulata were 0.82 and 8.53 µg/cm2, respectively, in a choice test, while azadirachtin showed ED50 of 0.10 and 0.59 µg/cm2, respectively. In a no-choice test, both insects refused to feed on leaves treated with 1 at doses of 0.1 µg/cm2 or greater inhibiting larval growth and dramatically reducing survival. The lethal doses 50 (LD50 of 1 were 0.39 and 0.68 µg/cm2 for S. frugiperda and E. paenulata, respectively. These results indicate that 1 has potential for development as botanical insecticides. Similar esters might be obtainable in large quantities as many edible crops produce wax esters that are discarded during food processing. Research on these materials could lead to the detection of similar waxes with insecticidal activity.

  19. Insecticidal Properties of a Highly Potent Wax Isolated from Dolichandra cynanchoides Cham.

    Science.gov (United States)

    Díaz Napal, Georgina; Carpinella, María C; Palacios, Sara M

    2016-08-11

    Bioassay-guided fractionation of an ethanolic extract of the aerial parts of Dolichandra cynanchoides Cham. (Bignoniaceae) led to the isolation of a natural wax with anti-insect activity against Spodoptera frugiperda (Noctuidae) and Epilachna paenulata (Coleptera). The compound was identified spectroscopically as an ester of a C27 fatty acid and a C25 alcohol, pentacosyl heptacosanoate (1). The effective doses of 1 for 50% feeding inhibition (ED50) of S. frugiperda and E. paenulata were 0.82 and 8.53 µg/cm², respectively, in a choice test, while azadirachtin showed ED50 of 0.10 and 0.59 µg/cm², respectively. In a no-choice test, both insects refused to feed on leaves treated with 1 at doses of 0.1 µg/cm² or greater inhibiting larval growth and dramatically reducing survival. The lethal doses 50 (LD50) of 1 were 0.39 and 0.68 µg/cm² for S. frugiperda and E. paenulata, respectively. These results indicate that 1 has potential for development as botanical insecticides. Similar esters might be obtainable in large quantities as many edible crops produce wax esters that are discarded during food processing. Research on these materials could lead to the detection of similar waxes with insecticidal activity.

  20. Two Predicted Transmembrane Domains Exclude Very Long Chain Fatty acyl-CoAs from the Active Site of Mouse Wax Synthase.

    Directory of Open Access Journals (Sweden)

    Steffen Kawelke

    Full Text Available Wax esters are used as coatings or storage lipids in all kingdoms of life. They are synthesized from a fatty alcohol and an acyl-CoA by wax synthases. In order to get insights into the structure-function relationships of a wax synthase from Mus musculus, a domain swap experiment between the mouse acyl-CoA:wax alcohol acyltransferase (AWAT2 and the homologous mouse acyl-CoA:diacylglycerol O-acyltransferase 2 (DGAT2 was performed. This showed that the substrate specificity of AWAT2 is partially determined by two predicted transmembrane domains near the amino terminus of AWAT2. Upon exchange of the two domains for the respective part of DGAT2, the resulting chimeric enzyme was capable of incorporating up to 20% of very long acyl chains in the wax esters upon expression in S. cerevisiae strain H1246. The amount of very long acyl chains in wax esters synthesized by wild type AWAT2 was negligible. The effect was narrowed down to a single amino acid position within one of the predicted membrane domains, the AWAT2 N36R variant. Taken together, we provide first evidence that two predicted transmembrane domains in AWAT2 are involved in determining its acyl chain length specificity.

  1. CUT1, an Arabidopsis gene required for cuticular wax biosynthesis and pollen fertility, encodes a very-long-chain fatty acid condensing enzyme.

    Science.gov (United States)

    Millar, A A; Clemens, S; Zachgo, S; Giblin, E M; Taylor, D C; Kunst, L

    1999-05-01

    Land plants secrete a layer of wax onto their aerial surfaces that is essential for survival in a terrestrial environment. This wax is composed of long-chain, aliphatic hydrocarbons derived from very-long-chain fatty acids (VLCFAs). Using the Arabidopsis expressed sequence tag database, we have identified a gene, designated CUT1, that encodes a VLCFA condensing enzyme required for cuticular wax production. Sense suppression of CUT1 in transgenic Arabidopsis plants results in waxless (eceriferum) stems and siliques as well as conditional male sterility. Scanning electron microscopy revealed that this was a severe waxless phenotype, because stems of CUT1-suppressed plants were completely devoid of wax crystals. Furthermore, chemical analyses of waxless plants demonstrated that the stem wax load was reduced to 6 to 7% of wild-type levels. This value is lower than that reported for any of the known eceriferum mutants. The severe waxless phenotype resulted from the downregulation of both the decarbonylation and acyl reduction wax biosynthetic pathways. This result indicates that CUT1 is involved in the production of VLCFA precursors used for the synthesis of all stem wax components in Arabidopsis. In CUT1-suppressed plants, the C24 chain-length wax components predominate, suggesting that CUT1 is required for elongation of C24 VLCFAs. The unique wax composition of CUT1-suppressed plants together with the fact that the location of CUT1 on the genetic map did not coincide with any of the known ECERIFERUM loci suggest that we have identified a novel gene involved in wax biosynthesis. CUT1 is currently the only known gene with a clearly established function in wax production.

  2. 21 CFR 186.1555 - Japan wax.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Japan wax. 186.1555 Section 186.1555 Food and Drugs... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan...

  3. Wax deposition in crude oil pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Assuncao, Pablo Morelato; Rodrigues, Lorennzo Marrochi Nolding [Universidade Federal do Espirito Santo, Sao Mateus, ES (Brazil). Centro Universitario Norte do Espirito Santo. Engenharia de Petroleo; Romero, Mao Ilich [University of Wyoming, Laramie, WY (United States). Enhanced Oil Recovery Institute], e-mail: mromerov@uwyo.edu

    2010-07-01

    Crude oil is a complex mixture of hydrocarbons which consists of aromatics, paraffins, naphthenics, resins asphaltenes, etc. When the temperature of crude oil is reduced, the heavy components, like paraffin, will precipitate and deposit on the pipe internal wall in the form of a wax-oil gel. The gel deposit consists of wax crystals that trap some amount of oil. As the temperature gets cooler, more wax will precipitate and the thickness of the wax gel will increase, causing gradual solidification of the crude and eventually the oil stop moving inside the offshore pipeline. Crude oil may not be able to be re-mobilized during re-startup. The effective diameter will be reduced with wax deposition, resulting in several problems, for example, higher pressure drop which means additional pumping energy costs, poor oil quality, use of chemical components like precipitation inhibitors or flowing facilitators, equipment failure, risk of leakage, clogging of the ducts and process equipment. Wax deposition problems can become so sever that the whole pipeline can be completely blocked. It would cost millions of dollars to remediate an offshore pipeline that is blocked by wax. Wax solubility decreases drastically with decreasing temperature. At low temperatures, as encountered in deep water production, is easy to wax precipitate. The highest temperature below which the paraffins begins to precipitate as wax crystals is defined as wax appearance temperature (WAT). Deposition process is a complex free surface problem involving thermodynamics, fluid dynamics, mass and heat transfer. In this work, a numerical analysis of wax deposition by molecular diffusion and shear dispersion mechanisms in crude oil pipeline is studied. Diffusion flux of wax toward the wall is estimated by Fick's law of diffusion, in similar way the shear dispersion; wax concentration gradient at the solid-liquid interface is obtained by the volume fraction conservation equation; and since the wax deposition

  4. Clustering of comb and propolis waxes based on the distribution of aliphatic constituents

    Directory of Open Access Journals (Sweden)

    Custodio Angela R.

    2003-01-01

    Full Text Available Chemical composition data for 41 samples of propolis waxes and 9 samples of comb waxes of Apis mellifera collected mainly in Brazil were treated using Principal Component Analysis (PCA and Hierarchical Cluster Analysis (HCA. For chemometrical analysis, the distribution of hydrocarbons and residues of alcohols and carboxylic acids of monoesters were considered. The clustering obtained revealed chemical affinities and differences not previously grasped by simple eye-inspection of the data. No consistent differences were detected between comb and propolis waxes. These and previous results suggest that hydrocarbons, carboxylic acids, aliphatic alcohols and esters from both comb and propolis waxes are bee-produced compounds and, hence, the differences detected between one and another region are dependent on genetic factors related to the insects rather than the local flora. The samples analyzed were split into two main clusters, one of them comprising exclusively material collected in the State of São Paulo. The results are discussed with respect to the africanization of honeybees that first took place in that State and therefrom irradiated to other parts of Brazil.

  5. Improve Toolmarks' Impressions in Soft Wax.

    Science.gov (United States)

    Finkelstein, Nir; Volkov, Nikolai; Tsach, Tsadok

    2017-05-01

    When the forensic toolmarks laboratory receives for examination and comparison a tool that is suspected of having been involved in a crime, the expert performs tests designed to determine whether or not the specific tool generates the same toolmarks as those found at the crime scene. This is performed by testing tool striation on a piece of soft metal, such as lead, and examining the marks left by the tool. Studies have shown that wax may be an optimal material for this purpose. This study examines the use of wax at different temperatures and shows that quality of results is better when the wax is cooled (recommended temperature is -18°C). At this temperature, the wax is flexible enough but does not smear and is not sticky. This makes the obtained marks clearer and of better quality. © 2017 American Academy of Forensic Sciences.

  6. ETHNOECOLOGY AND ETHNOBOTANY OF THE PALM CARNAUBA WAX IN BRAZILIAN SEMI-ARID

    Directory of Open Access Journals (Sweden)

    Rodrigo Ferreira de Sousa

    2015-12-01

    Full Text Available The aim of this study was to investigate aspects of ethnoecological and ethnobotanical of carnauba wax (Copernicia prunifera (Miller H. E. Moore, Arecaceae in an extractive community of municipality of Ipanguaçu, Rio Grande do Norte state. We interviewed key informants, using the technique of inducing nonspecific, guided tour and direct observation to confirm the data. According to most residents of Pedro Ezequiel Araújo community, the area of carnauba wax in the region is natural. In the research ethnoecological, 73% of informants reported the occurrence of “a different kind of carnauba”, known as “white carnauba” phenotypically distinct from the “common carnauba wax” by presenting clear stipe, smaller fruits and absence of spines on the petiole, and is rare at the study site. Much of the informants observed phenological phases of carnauba wax, being consistent in stating that the species has fruits dispersed by bats. In ethnobotany, powder wax was cited by all as the most important product extracted from leaves of carnauba and the most used, followed by fruit, stem and root. Were still reported the division of work in the extraction of powder wax from the carnauba. The results of this research will contribute to knowledge of ethnobotanical and ethnoecological carnauba, supporting strategies for management and conservation of natural populations.

  7. Microencapsulation of Flavors in Carnauba Wax

    OpenAIRE

    Milanovic, Jelena; Manojlovic, Verica; Levic, Steva; Rajic, Nevenka; Nedovic, Viktor; Bugarski, Branko

    2010-01-01

    The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM), while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at aroun...

  8. Nano ski wax, effects and benefits

    OpenAIRE

    Haaland, Nora Holst

    2013-01-01

    The effects of the gliding properties of ski waxes are often discussed and many speculations and assumptions are made. However there are not many studies and documented results in this field. This project is carried out in cooperation with Olympiatoppen and the Norwegian ski team to research and document the effects and benefits of gliding waxes. Ski base material consists of ultra-high molecular weight polyethylene (UHMWPE) in semicrystalline state. The focus will be on the material changes ...

  9. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing

    2013-10-10

    We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes . The hot-melt adhesive wax can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate (PMMA) film, glass sheets, or metal plate. The bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by vacuating and venting the chip in a hot-water bath. To study the biocompatibility and applicability of the wax-based microfluidic chip, we tested the PCR compatibility with the chip materials first. Then we applied the wax-paper based microfluidic chip to HeLa cell electroporation (EP ). Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein (GFP) recombinant Escherichia coli (E. coli) bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration.

  10. Comb and propolis waxes from Brazil (states of São Paulo and Paraná

    Directory of Open Access Journals (Sweden)

    Negri Giuseppina

    2000-01-01

    Full Text Available Samples of propolis and comb waxes of Apis mellifera were analyzed. Monoesters predominated, followed by hydrocarbons. The constituents were identified by gas chromatography/mass spectrometry. Wide variations in the patterns of hydrocarbons, acids and alcohols of the esters were found. Hydrocarbon chains cover the range C23 - C35, C27 and C31 alkanes predominating. The main carboxylic acid was C16:0, followed by C18:0 and C18:1. The alcohols were predominantly saturated n-homologues, ranging from C24 to C32, C30 being the most abundant, followed by C24. No differences were found to allow a distinction, suggesting a common origin for both wax sources.

  11. STEM?!?!

    Science.gov (United States)

    Merrill, Jen

    2012-01-01

    The author's son has been an engineer since birth. He never asked "why" as a toddler, it was always "how's it work?" So that he wanted a STEM-based home education was no big surprise. In this article, the author considers what kind of curricula would work best for her complex kid.

  12. Long-chain wax esterns and diphenylamine in fire coral Millepora dichotoma and Millepora platyphylla from Saudi Red Sea Coast

    Directory of Open Access Journals (Sweden)

    Sultan S. Al-Lihaibi

    2002-06-01

    Full Text Available The characterization of the non-protein constituents of two species of fire corals Millepora dichotoma and Millepora platyphylla, exhibits very interesting results. The compounds were identified by gas chromatography-mass spectrometry (GCMS and nuclear magnetic resonance (NMR spectroscopy. The solvent extracts of the two species revealed four wax esters. The compounds were identified as C30H60O2, C32H64O2, C34H68O2 and C36H72O2 respectively. The presence of these compounds has been reported previously in different marine organisms as well as in marine samples. It is interesting that there were some variations in the number and nature of isomers of similar wax esters reported earlier. Long-chain wax esters are normally waxy in nature and their presence in fire coral plays a vital role in the nutrient transfer to the coral mass. They may also act as a protective coating of the nematocyst of dactylozooid. The coral species were also subjected to mild acidic hydrolysis, followed by neutralization and partitioning between water and ether. The organic phase was dried and purified by column chromatography and thin layer chromatography (TLC. Diphenylamine was revealed as the main product in one of the fractions. It is worth noting that diphenylamine is reported for the first time as a marine natural product. Diphenylamine is known to be toxic and causes allergic reactions to the skin, so it can be considered as responsible for the stinging property of fire coral.

  13. Microencapsulation of Flavors in Carnauba Wax

    Directory of Open Access Journals (Sweden)

    Branko Bugarski

    2010-01-01

    Full Text Available The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM, while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products.

  14. Microencapsulation of flavors in carnauba wax.

    Science.gov (United States)

    Milanovic, Jelena; Manojlovic, Verica; Levic, Steva; Rajic, Nevenka; Nedovic, Viktor; Bugarski, Branko

    2010-01-01

    The subject of this study is the development of flavor wax formulations aimed for food and feed products. The melt dispersion technique was applied for the encapsulation of ethyl vanillin in wax microcapsules. The surface morphology of microparticles was investigated using scanning electron microscope (SEM), while the loading content was determined by HPLC measurements. This study shows that the decomposition process under heating proceeds in several steps: vanilla evaporation occurs at around 200 °C, while matrix degradation starts at 250 °C and progresses with maxima at around 360, 440 and 520 °C. The results indicate that carnauba wax is an attractive material for use as a matrix for encapsulation of flavours in order to improve their functionality and stability in products.

  15. Extraction and Characterization of Sugarcane Peel Wax

    OpenAIRE

    Inarkar, Mangesh B.; Lele, S. S.

    2012-01-01

    Sugarcane peel is an agrowaste product and contains considerable amount of wax. This has a good technoeconomic potential. In view of this, the present study aims at extraction and characterization of wax from sugarcane peel. The yield of crude wax was 0.95% on dry weight basis. During Fourier transform-infrared spectroscopy (FT-IR) prominent peaks obtained at 2921.73 and 2851.64 (–CH), 1463.44 (–CH2), 1376.96 (–CH3), 1108.4 and 1170.16 (–C–O) 3395.60 (–OH), 1710.25 (–CHO), and 1736.63 (–COOH)...

  16. Comparative characterization of a wool-wax extract by two complementary chromatographic techniques.

    Science.gov (United States)

    Jover, Eric; Domínguez, Carmen; Erra, Pilar; Bayona, Josep Maria

    2006-01-01

    A detailed characterization of lipids present in a wool-wax extract, obtained by supercritical fluid extraction, is presented. Thin-layer chromatography coupled to a flame ionization detector (TLC-FID) has been used as a screening technique to identify the different chemical classes of complex mixtures. Furthermore, to confirm peak identification obtained by TLC-FID and to check its suitability as a quality control technique, preparative TLC fractionation has been carried out by re-analyzing the different fractions obtained by TLC-FID and by gas chromatography coupled to mass spectrometry in the electron impact and in the chemical ionization modes. By means of this comparative study, the TLC-FID identification has been confirmed. Also, the complementarity of the different techniques used confirmed the identification of different lipid classes, namely fatty acids, alcohols, sterols, sterane diol, stanone, steryl sulphate, hydroxyacids, alkane diols, aliphatic and steryl esters, hydroxy steryl esters, triacylglycerol, diesters, and ceramides types II and VI.

  17. Investigation of drug release from carnauba wax matrices: a case ...

    African Journals Online (AJOL)

    A study was carried out to assess the effect of carnauba wax particle size on sustained release characteristics, the effect of drug loading on release and the kinetics of propranolol hydrochloride release from carnauba wax matrices. The results obtained showed that small particles (180 250 µ m) of carnauba wax had superior ...

  18. The composition of wax and oil in green coffee beans

    NARCIS (Netherlands)

    Folstar, P.

    1976-01-01

    Methods for the isolation of wax and oil from green coffee beans were studied and a method for the quantitative extraction of coffee oil from the beans was introduced. Coffee wax, coffee oil and wax-free coffee oil as well as the unsaponifiable matter prepared from each were fractionated by column

  19. Influence of Different Waxes on the Physical Properties of Linear ...

    African Journals Online (AJOL)

    NJD

    2005-12-22

    Dec 22, 2005 ... Department of Chemistry, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba, 9866 South Africa. Received 22 ... The polymer-wax miscibilities differed with the type of wax used, and with the ... blends,8–13 but in all cases high (up to 50%) wax contents were mixed into the ...

  20. Wax Impaction in Nigerian School Children. | Eziyi | East and ...

    African Journals Online (AJOL)

    Wax Impaction in Nigerian School Children. ... East and Central African Journal of Surgery ... The aim of this study was to determine the prevalence of impacted ear wax in primary school children and to determine, if there is any association between socioeconomic status and the occurrence of wax impaction among these ...

  1. Extraction and characterization of wax from sugarcane bagasse and the enzymatic hydrolysis of dewaxed sugarcane bagasse.

    Science.gov (United States)

    Qi, Gaoxiang; Peng, Fen; Xiong, Lian; Lin, Xiaoqing; Huang, Chao; Li, Hailong; Chen, Xuefang; Chen, Xinde

    2017-03-16

    Extraction of high-value products from agricultural wastes is an important component for sustainable bioeconomy development. In this study, wax extraction from sugarcane bagasse was performed and the beneficial effect of dewaxing pretreatment on the enzymatic hydrolysis was investigated. About 1.2% (w/w) of crude sugarcane wax was obtained from the sugarcane bagasse using the mixture of petroleum ether and ethanol (mass ratio of 1:1) as the extraction agent. Results of Fourier-transform infrared characterization and gas chromatography-mass spectrometry qualitative analysis showed that the crude sugarcane wax consisted of fatty fractions (fatty acids, fatty aldehydes, hydrocarbons, and esters) and small amount of lignin derivatives. In addition, the effect of dewaxing pretreatment on the enzymatic hydrolysis of sugarcane bagasse was also investigated. The digestibilities of cellulose and xylan in dewaxed sugarcane bagasse were 18.7 and 10.3%, respectively, compared with those of 13.1 and 8.9% obtained from native sugarcane bagasse. The dewaxed sugarcane bagasse became more accessible to enzyme due to the disruption of the outermost layer of the waxy materials.

  2. Wax Impaction in Nigerian School Children.

    African Journals Online (AJOL)

    DELL

    the middle social class and 164 (26.0%) from the upper class. A very large .... Health education to improve the low level of awareness among parents and ... Brand-Auraban A, Kopito L, Shwachman H. Chemical analysis of some inorganic elements in ... Fairey A, Freer CB, Machin D. Ear wax and otitis media in children.

  3. Comparative High-Resolution Mapping of the Wax Inhibitors Iw1 and Iw2 in Hexaploid Wheat

    OpenAIRE

    Haibin Wu; Jinxia Qin; Jun Han; Xiaojie Zhao; Shuhong Ouyang; Yong Liang; Dong Zhang; Zhenzhong Wang; Qiuhong Wu; Jingzhong Xie; Yu Cui; Huiru Peng; Qixin Sun; Zhiyong Liu

    2013-01-01

    The wax (glaucousness) on wheat leaves and stems is mainly controlled by two sets of genes: glaucousness loci (W1 and W2) and non-glaucousness loci (Iw1 and Iw2). The non-glaucousness (Iw) loci act as inhibitors of the glaucousness loci (W). High-resolution comparative genetic linkage maps of the wax inhibitors Iw1 originating from Triticum dicoccoides, and Iw2 from Aegilops tauschii were developed by comparative genomics analyses of Brachypodium, sorghum and rice genomic sequences correspond...

  4. Composition of secondary alcohols, ketones, alkanediols, and ketols in Arabidopsis thaliana cuticular waxes

    Science.gov (United States)

    Wen, Miao; Jetter, Reinhard

    2009-01-01

    Arabidopsis wax components containing secondary functional groups were examined (i) to test the biosynthetic relationship between secondary alcohols and ketols and (ii) to determine the regiospecificity and substrate preference of the enzyme involved in ketol biosynthesis. The stem wax of Arabidopsis wild type contained homologous series of C27 to C31 secondary alcohols (2.4 μg cm−2) and C28 to C30 ketones (6.0 μg cm−2) dominated by C29 homologues. In addition, compound classes containing two secondary functional groups were identified as C29 diols (∼0.05 μg cm−2) and ketols (∼0.16 μg cm−2). All four compound classes showed characteristic isomer distributions, with functional groups located between C-14 and C-16. In the mah1 mutant stem wax, diols and ketols could not be detected, while the amounts of secondary alcohols and ketones were drastically reduced. In two MAH1-overexpressing lines, equal amounts of C29 and C31 secondary alcohols were detected. Based on the comparison of homologue and isomer compositions between the different genotypes, it can be concluded that biosynthetic pathways lead from alkanes to secondary alcohols, and via ketones or diols to ketols. It seems plausible that MAH1 is the hydroxylase enzyme involved in all these conversions in Arabidopsis thaliana. PMID:19346242

  5. Ester Tuiksoo / Ester Tuiksoo ; interv. Piret Tali

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Juhan Partsi valitsuse (05.04.2004-13.04.2005) ja Andrus Ansipi valitsuse (13.04.2005-) põllumajandusminister Ester Tuiksoo oma lapsepõlvest ja elukutsevalikust, poliitilise karjääri algusest ja erakonna valikust, ministritöö kogemustest, naistest poliitikas

  6. The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers.

    Science.gov (United States)

    Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K; Tomasi, Pernell; Dyer, John M; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Parsons, Eugene P; Jenks, Matthew A; Lü, Shiyou

    2017-02-01

    We report n-6 monounsaturated primary alcohols (C26:1, C28:1, and C30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4's principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation's effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem. © 2017 American Society of Plant Biologists. All Rights Reserved.

  7. Dental wax decreases calculus accumulation in small dogs.

    Science.gov (United States)

    Smith, Mark M; Smithson, Christopher W

    2014-01-01

    A dental wax was evaluated after unilateral application in 20 client-owned, mixed and purebred small dogs using a clean, split-mouth study model. All dogs had clinical signs of periodontal disease including plaque, calculus, and/or gingivitis. The wax was randomly applied to the teeth of one side of the mouth daily for 30-days while the contralateral side received no treatment. Owner parameters evaluated included compliance and a subjective assessment of ease of wax application. Gingivitis, plaque and calculus accumulation were scored at the end of the study period. Owners considered the wax easy to apply in all dogs. Compliance with no missed application days was achieved in 8 dogs. The number of missed application days had no effect on wax efficacy. There was no significant difference in gingivitis or plaque accumulation scores when comparing treated and untreated sides. Calculus accumulation scores were significantly less (22.1 %) for teeth receiving the dental wax.

  8. Natural oils and waxes: studies on stick bases.

    Science.gov (United States)

    Budai, Lívia; Antal, István; Klebovich, Imre; Budai, Marianna

    2012-01-01

    The objective of the present article was to examine the role of origin and quantity of selected natural oils and waxes in the determination of the thermal properties and hardness of stick bases. The natural oils and waxes selected for the study were sunflower, castor, jojoba, and coconut oils. The selected waxes were yellow beeswax, candelilla wax, and carnauba wax. The hardness of the formulations is a critical parameter from the aspect of their application. Hardness was characterized by the measurement of compression strength along with the softening point, the drop point, and differential scanning calorimetry (DSC). It can be concluded that coconut oil, jojoba oil, and carnauba wax have the greatest influence on the thermal parameters of stick bases.

  9. Effect of asphaltenes on crude oil wax crystallization

    DEFF Research Database (Denmark)

    Kriz, Pavel; Andersen, Simon Ivar

    2005-01-01

    The paper summarizes the experimental work done on asphaltene influenced wax crystallization. Three different asphaltenes (from stable oil, instable oil, and deposit) were mixed at several concentrations or dispersions into the waxy crude oil. These blends were evaluated by viscometry and yield...... stress measurement and compared with the original crude oil. A complex asphaltene−wax interaction as a function of asphaltene concentration and degree of asphaltene dispersion under dynamic and static condition was observed. The crystallization and the wax network strength was strongly dependent...... influence the wax crystallization at static condition more significantly than the more flocculated....

  10. Modeling of asphaltene and wax precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Chung, F.; Sarathi, P.; Jones, R.

    1991-01-01

    This research project was designed to focus on the development of a predictive technique for organic deposition during gas injection for petroleum EOR. A thermodynamic model has been developed to describe the effects of temperature, pressure, and composition on asphaltene precipitation. The proposed model combines regular solution theory with Flory-Huggins polymer solutions theory to predict maximum volume fractions of asphaltene dissolved in oil. The model requires evaluation of vapor-liquid equilibria, first using an equation of state followed by calculations of asphaltene solubility in the liquid-phase. A state-of-the-art technique for C{sub 7+} fraction characterization was employed in developing this model. The preliminary model developed in this work was able to predict qualitatively the trends of the effects of temperature, pressure, and composition. Since the mechanism of paraffinic wax deposition is different from that of asphaltene deposition, another thermodynamic model based on the solid-liquid solution theory was developed to predict the wax formation. This model is simple and can predict the wax appearance temperature with reasonable accuracy. Accompanying the modeling work, experimental studies were conducted to investigate the solubility of asphaltene in oil land solvents and to examine the effects of oil composition, CO{sub 2}, and solvent on asphaltene precipitation and its properties. This research focused on the solubility reversibility of asphaltene in oil and the precipitation caused by CO{sub 2} injection at simulated reservoir temperature and pressure conditions. These experiments have provided many observations about the properties of asphaltenes for further improvement of the model, but more detailed information about the properties of asphaltenes in solution is needed for the development of more reliable asphaltene characterization techniques. 50 refs., 8 figs., 7 tabs.

  11. Presence of carotinoids in peat wax

    Energy Technology Data Exchange (ETDEWEB)

    Yurkevich, E.A.; Dolidovich, E.F.; Bel' kevich, P.I.; Sheremet, L.S.; Drozdovskaya, S.V.

    1986-05-01

    Discusses biologically active substances present in peat which have various pharmacological properties. Describes separation of fractions rich in carotinoids from extracts of wax tar obtained by benzine treatment of highly decomposed pine-cotton grass peat. Extraction was carried out using hot ethanol. States that although identification of individual carotinoid in the fractions separated is very difficult due to complicity of composition, the tests carried out made it possible to infer that fractions studied contain not only xanthophylls but also fucoxanthains (formed in small amounts in nature) with fairly stable structure. Ultraviolet and infrared spectra of the carotinoid containing fraction in ethanol extracts are given. 6 refs.

  12. Characterization of wax deposition by different experimental techniques - a comparison

    Energy Technology Data Exchange (ETDEWEB)

    Lindeman, Olga; Allenson, Steve

    2006-03-15

    Crude oils consist of various fractions of hydrocarbons, including n-paraffins. The paraffins precipitate out of oil below the temperature called WAT (wax appearance temperature) and accumulate in flow lines causing major transport problems. Prediction of paraffin deposition is, therefore, a key element of flow assurance programs. The purpose of this study was to develop a general and reliable approach to prediction of wax deposition based on a critical comparison of several practical lab techniques. Wax deposition study was conducted on multiple crude oils using various testing protocols and equipment. One experimental technique was a cold stress test of wax deposition combined with ketone precipitation of waxy paraffin crystals. Another set of experiments was carried out for wax deposits formed on the surface of U-tubes and cold fingers of different designs. A comparison of the effectiveness of several wax inhibitors was conducted for these crude oils by using the selected deposition techniques. In each test method the amount of precipitated wax was recorded and compared. The deposits were characterized by melting point, qualitative and quantitative analysis of the wax components using DSC, SARA and HTGC analyses. Efficiency of paraffin inhibitors was correlated with a profile of n-paraffins distribution in the deposits. The limitations and advantages of different deposition techniques were analyzed and discussed. A new test design designated ''cold tube'' is proposed. (Author) (tk)

  13. Comparison of different experimental techniques used for wax deposition testing

    Energy Technology Data Exchange (ETDEWEB)

    Allenson, Stephen; Johnston, Angela [Nalco Energy Services, Sugar Land, TX (United States)

    2008-07-01

    Crude oils consist of various fractions of hydrocarbons, including n-paraffins. The paraffins precipitate out of oil below the temperature called WAT (wax appearance temperature) and accumulate in flow lines and pipelines causing major transport problems. Prediction of paraffin deposition is, therefore, a key element of flow assurance programs. The purpose of this study was to develop a general and reliable approach to prediction of wax deposition based on a critical comparison of several practical lab techniques. Wax deposition study was conducted on five separate crude oils by using a varying protocols and equipment. One experimental technique was a cold stress test of wax deposition combined with ketone precipitation of waxy paraffin crystals. Another set of experiments were carried out for wax deposits formed on the surface of U-tubes and cold fingers of different designs. A comparison of the effectiveness of several wax inhibitors was conducted for these crude oils by using the selected deposition techniques. In each test method the amount of precipitated wax was recorded and compared. The deposits were characterized by melting point, qualitative and quantitative analysis of the wax components using DSC, SARA and HTGC analyses. Efficiency of paraffin inhibitors was correlated with a profile of n-paraffins distribution in the deposits. The limitations and advantages of different deposition techniques were analyzed and discussed. (author)

  14. Biochemical response of sweet potato to bemul-wax coating ...

    African Journals Online (AJOL)

    Sweet potato (Ipomoea batatas Linn) tuber is a very nutritious but highly perishable crop that is subject to high wastages due to non-availability of appropriate storage techniques. This work assessed the effectiveness of treating the tubers with calcium chloride dip (CCD), bemul-wax (B-wax) and their combinations ...

  15. Crystal morphology of sunflower wax in soybean oil organogel

    Science.gov (United States)

    While sunflower wax has been recognized as an excellent organogelator for edible oil, the detailed morphology of sunflower wax crystals formed in an edible oil organogel has not been fully understood. In this study, polarized light microscopy, phase contrast microscopy, scanning electron microscopy ...

  16. Preparation and Characterization of Sugar Cane Wax Microspheres ...

    African Journals Online (AJOL)

    ... for the test formulation. Conclusion: Based on this study, it can be concluded that the developed indomethacin-loaded wax microsheres and Microcid® SR capsule are bioequivalent in terms of rate and extent of absorption. Keywords: Indomethacin, Bioavailability, Controlled release Sugarcane wax, Release kinetics.

  17. Wax combs mediate nestmate recognition by guard honeybees

    DEFF Research Database (Denmark)

    D'Ettorre, Patrizia; Wenseleers, Tom; Dawson, Jenny

    2006-01-01

    Research has shown that the wax combs are important in the acquisition of colony odour in the honeybee, Apis mellifera. However, many of these studies were conducted in the laboratory or under artificial conditions. We investigated the role of the wax combs in nestmate recognition in the natural...

  18. Statistical Optimization of Sustained Release Venlafaxine HCI Wax Matrix Tablet.

    Science.gov (United States)

    Bhalekar, M R; Madgulkar, A R; Sheladiya, D D; Kshirsagar, S J; Wable, N D; Desale, S S

    2008-01-01

    The purpose of this research was to prepare a sustained release drug delivery system of venlafaxine hydrochloride by using a wax matrix system. The effects of bees wax and carnauba wax on drug release profile was investigated. A 3(2) full factorial design was applied to systemically optimize the drug release profile. Amounts of carnauba wax (X(1)) and bees wax (X(2)) were selected as independent variables and release after 12 h and time required for 50% (t(50)) drug release were selected as dependent variables. A mathematical model was generated for each response parameter. Both waxes retarded release after 12 h and increases the t(50) but bees wax showed significant influence. The drug release pattern for all the formulation combinations was found to be approaching Peppas kinetic model. Suitable combination of two waxes provided fairly good regulated release profile. The response surfaces and contour plots for each response parameter are presented for further interpretation of the results. The optimum formulations were chosen and their predicted results found to be in close agreement with experimental findings.

  19. Epicuticular wax crystals of Wollemia nobilis: morphology and chemical composition.

    Science.gov (United States)

    Dragota, Simona; Riederer, Markus

    2007-08-01

    The morphology of the epicuticular leaf waxes of Wollemia nobilis (Araucariaceae) was studied with special emphasis on the relationship between the microstructure of epicuticular wax crystals and their chemical composition. Wollemia nobilis is a unique coniferous tree of the family Araucariaceae and is of very high scientific value as it is the sole living representative of an ancient genus, which until 1994 was known only from fossils. Scanning electron microscopy (SEM), gas chromatography (GC) combined with mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR) were used for characterizing the morphology and the chemical structure of the epicuticular wax layer of W. nobilis needles. The main component of the leaf epicuticular wax of W. nobilis is nonacosan-10-ol. This secondary alcohol together with nonacosane diols is responsible for the tubular habit of the epicuticular wax crystals. Scanning electron micrographs revealed differences in the fine structure of adaxial and abaxial leaf surfaces that could be explained by gas chromatographic studies after selective mechanical removal of the waxes. SEM investigations established the tubular crystalline microstructure of the epicuticular wax of W. nobilis leaves. GC-MS and NMR experiments showed that nonacosan-10-ol is the major constituent of the epicuticular wax of W. nobilis leaves.

  20. 21 CFR 178.3770 - Polyhydric alcohol esters of oxidatively refined (Gersthofen process) montan wax acids.

    Science.gov (United States)

    2010-04-01

    ... great. It is of the greatest importance that all glassware be scrupulously cleaned to remove all organic... measurements. The spectrophotometer shall also meet the following performance requirements: Absorbance.... procedure Before proceeding with analysis of a sample, determine the absorbance in a 1-centimeter path cell...

  1. Physical Characteristics of Tetrahydroxy and Acylated Derivatives of Jojoba Liquid Wax in Lubricant Applications

    Science.gov (United States)

    Biresaw, Girma; Gordon, Sherald

    2018-01-01

    Jojoba liquid wax is a mixture of esters of long-chain fatty acids and fatty alcohols mainly C38:2–C46:2. The oil exhibits excellent emolliency on the skin and, therefore, is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the jojoba (Simmondsia chinensis) plant which occurs naturally in the Sonora Desert in the United States and northwestern Mexico as well as in the northeastern Sahara desert. The seed contains 50–60% oil by dry weight. The plant has been introduced into Australia, Argentina, and Israel for commercial production of the jojoba oil. As a natural lubricant, we are seeking to explore its potential as a renewable industrial lubricant additive. Thus, we have chemically modified the carbon-carbon double bonds in the oil structure in order to improve its already good resistance to air oxidation so as to enhance its utility as well as its shelf life in nonpersonal care applications. To achieve this goal, we have hydroxylated its –C=C– bonds. Acylation of the resulting hydroxyl moieties has generated short-chain vicinal acyl substituents on the oil which keep the wax liquid, improving its cold flow properties and also protecting it from auto-oxidation and rancidity. PMID:29484216

  2. Physical Characteristics of Tetrahydroxy and Acylated Derivatives of Jojoba Liquid Wax in Lubricant Applications

    Directory of Open Access Journals (Sweden)

    Rogers E. Harry-O’kuru

    2018-01-01

    Full Text Available Jojoba liquid wax is a mixture of esters of long-chain fatty acids and fatty alcohols mainly C38:2–C46:2. The oil exhibits excellent emolliency on the skin and, therefore, is a component in many personal care cosmetic formulations. The virgin oil is a component of the seed of the jojoba (Simmondsia chinensis plant which occurs naturally in the Sonora Desert in the United States and northwestern Mexico as well as in the northeastern Sahara desert. The seed contains 50–60% oil by dry weight. The plant has been introduced into Australia, Argentina, and Israel for commercial production of the jojoba oil. As a natural lubricant, we are seeking to explore its potential as a renewable industrial lubricant additive. Thus, we have chemically modified the carbon-carbon double bonds in the oil structure in order to improve its already good resistance to air oxidation so as to enhance its utility as well as its shelf life in nonpersonal care applications. To achieve this goal, we have hydroxylated its –C=C– bonds. Acylation of the resulting hydroxyl moieties has generated short-chain vicinal acyl substituents on the oil which keep the wax liquid, improving its cold flow properties and also protecting it from auto-oxidation and rancidity.

  3. Self‐Replenishable Anti‐Waxing Organogel Materials†

    Science.gov (United States)

    Yao, Xi; Wu, Shuwang; Chen, Lie; Ju, Jie; Gu, Zhandong; Liu, Mingjie; Jiang, Lei

    2015-01-01

    Abstract Solid deposition, such as the formation of ice on outdoor facilities, the deposition of scale in water reservoirs, the sedimentation of fat, oil, and grease (FOG) in sewer systems, and the precipitation of wax in petroleum pipelines, cause a serious waste of resources and irreversible environmental pollution. Inspired by fish and pitcher plants, we present a self‐replenishable organogel material which shows ultra‐low adhesion to solidified paraffin wax and crude oil by absorption of low‐molar‐mass oil from its crude‐oil environment. Adhesion of wax on the organogel surface was over 500 times lower than adhesion to conventional material surfaces and the wax was found to slide off under the force of gravity. This design concept of a gel with decreased adhesion to wax and oil can be extended to deal with other solid deposition problems. PMID:26083324

  4. Esters van tetrathioorthotinzuur

    NARCIS (Netherlands)

    Kramer, Jan

    1934-01-01

    Claesson claims to have obtained the tetraethyl ester of tetrathioorthostannic acid by shaking an aqueous solution of stannic chloride with ethylmercaptan and by distilling the heavy oily product. This could not be confirmed. A mixture of different products is formed, containing possibly among

  5. Rapamycin carbonate esters

    OpenAIRE

    Rhodes, A; Sandhu, S S; Onis, J. E; McKendrick, John

    2009-01-01

    Certain embodiments include carbonate esters of rapamycin at position 42 that are synthesized by a lipase catalyzed regio-specific process. These compounds or a pharmaceutically acceptable salt thereof are useful in the treatment of organ and tissue transplant rejection, autoimmune disease, proliferative disorder, restenosis, cancer, or microbial infection.

  6. Apomorphine and its esters

    DEFF Research Database (Denmark)

    Borkar, Nrupa; Chen, Zhizhong; Saaby, Lasse

    2016-01-01

    Oral delivery of apomorphine via prodrug principle may be a potential treatment for Parkinson's disease. The purpose of this study was to investigate the transport and stability of apomorphine and its esters across Caco-2 cell monolayer and their affinity towards chylomicrons. Apomorphine...

  7. Phosphate Esters, Thiophosphate Esters and Metal Thiophosphates as Lubricant Additives

    Directory of Open Access Journals (Sweden)

    David W. Johnson

    2013-12-01

    Full Text Available Phosphate esters, thiophosphate esters and metal thiophosphates have been used as lubricant additives for over 50 years. While their use has been extensive, a detailed knowledge of how they work has been a much more recent development. In this paper, the use of phosphate esters and thiophosphate esters as anti-wear or extreme pressure additives is reviewed with an emphasis on their mechanism of action. The review includes the use of alkyl phosphates, triaryl phosphates and metal containing thiophosphate esters. The mechanisms of these materials interacting with a range of iron and steel based bearing material are examined.

  8. McWRI1, a transcription factor of the AP2/SHEN family, regulates the biosynthesis of the cuticular waxes on the apple fruit surface under low temperature.

    Science.gov (United States)

    Hao, Suxiao; Ma, Yiyi; Zhao, Shuang; Ji, Qianlong; Zhang, Kezhong; Yang, Mingfeng; Yao, Yuncong

    2017-01-01

    Cuticular waxes of plant and organ surfaces play an important role in protecting plants from biotic and abiotic stress and extending the freshness, storage time and shelf life in the post-harvest agricultural products. WRI1, a transcription factor of AP2/SHEN families, had been found to trigger the related genes taking part in the biosynthesis of seed oil in many plants. But whether WRI1 is involved in the biosynthesis of the cuticular waxes on the Malus fruits surface has been unclear. We investigated the changes of wax composition and structure, the related genes and WRI1 expression on Malus asiatica Nakai and sieversii fruits with the low temperature treatments, found that low temperature induced the up-regulated expression of McWRI1, which promoted gene expression of McKCS, McLACs and McWAX in very-long-chain fatty acid biosynthesis pathway, resulting in the accumulation of alkanes component and alteration of wax structure on the fruit surface. Corresponding results were verified in McWRI1 silenced by VIGS, and WRI1 silenced down-regulated the related genes on two kinds of fruits, it caused the diversity alteration in content of some alkanes, fatty acid and ester component in two kinds of fruits. We further conducted Y1H assay to find that McWRI1 transcription factor activated the promoter of McKCS, McLAC and McWAX to regulate their expression. These results demonstrated that McWRI1 is involved in regulating the genes related synthesis of very long chain fatty acid on surface of apple fruits in storage process, providing a highlight for improvement of the modified atmosphere storage of apple fruits.

  9. Physiological and transcriptional characterization of Saccharomyces cerevisiae engineered for production of fatty acid ethyl esters

    DEFF Research Database (Denmark)

    de Jong, Bouke Wim; Siewers, Verena; Nielsen, Jens

    2016-01-01

    Saccharomyces cerevisiae has previously been engineered to become a cell factory for the production of fatty acid ethyl esters (FAEEs), molecules suitable for crude diesel replacement. To find new metabolic engineering targets for the improvement of FAEE cell factories, three different FAEE......-producing strains of S. cerevisiae, constructed previously, were compared and characterized by quantification of key fluxes and genome-wide transcription analysis. From both the physiological and the transcriptional data, it was indicated that strain CB2I20, with high expression of a heterologous wax ester synthase...... gene (ws2) and strain BdJ15, containing disruptions of genes DGA1, LRO1, ARE1, ARE2 and POX1, which prevent the conversion of acyl-CoA to sterol esters, triacylglycerides and the degradation to acetyl-CoA, triggered oxidative stress that consequently influenced cellular growth. In the latter strain...

  10. Fatty acid methyl ester profiles of bat wing surface lipids.

    Science.gov (United States)

    Pannkuk, Evan L; Fuller, Nathan W; Moore, Patrick R; Gilmore, David F; Savary, Brett J; Risch, Thomas S

    2014-11-01

    Sebocytes are specialized epithelial cells that rupture to secrete sebaceous lipids (sebum) across the mammalian integument. Sebum protects the integument from UV radiation, and maintains host microbial communities among other functions. Native glandular sebum is composed primarily of triacylglycerides (TAG) and wax esters (WE). Upon secretion (mature sebum), these lipids combine with minor cellular membrane components comprising total surface lipids. TAG and WE are further cleaved to smaller molecules through oxidation or host enzymatic digestion, resulting in a complex mixture of glycerolipids (e.g., TAG), sterols, unesterified fatty acids (FFA), WE, cholesteryl esters, and squalene comprising surface lipid. We are interested if fatty acid methyl ester (FAME) profiling of bat surface lipid could predict species specificity to the cutaneous fungal disease, white nose syndrome (WNS). We collected sebaceous secretions from 13 bat spp. using Sebutape(®) and converted them to FAME with an acid catalyzed transesterification. We found that Sebutape(®) adhesive patches removed ~6× more total lipid than Sebutape(®) indicator strips. Juvenile eastern red bats (Lasiurus borealis) had significantly higher 18:1 than adults, but 14:0, 16:1, and 20:0 were higher in adults. FAME profiles among several bat species were similar. We concluded that bat surface lipid FAME profiling does not provide a robust model predicting species susceptibility to WNS. However, these results provide baseline data that can be used for lipid roles in future ecological studies, such as life history, diet, or migration.

  11. WAX ActiveLibrary: a tool to manage information overload.

    Science.gov (United States)

    Hanka, R; O'Brien, C; Heathfield, H; Buchan, I E

    1999-11-01

    WAX Active-Library (Cambridge Centre for Clinical Informatics) is a knowledge management system that seeks to support doctors' decision making through the provision of electronic books containing a wide range of clinical knowledge and locally based information. WAX has been piloted in several regions in the United Kingdom and formally evaluated in 17 GP surgeries based in Cambridgeshire. The evaluation has provided evidence that WAX Active-Library significantly improves GPs' access to relevant information sources and by increasing appropriate patient management and referrals this might also lead to an improvement in clinical outcomes.

  12. Wax deposit accumulation in a ``cylindrical Couette'' geometry

    Science.gov (United States)

    Benallal, Amine; Maurel, Philippe; Agassant, Jean François

    2008-11-01

    Models used to predict wax deposits overestimate the deposit thickness, and they require fitting parameters to match computational results to experimental data. A new approach is proposed. Waxy crude oil is considered as a viscoplastic Bingham fluid in which both viscosity and yield stress depend on temperature and quantity of wax crystals. Numerical simulations of the flow in a "cylindrical Couette" geometry were carried out. The numerical results highlight the influence of wax crystal content on the flow pattern, especially when comparing yielded and unyielded regions. A static layer region appears near the colder wall, representing the deposit. To cite this article: A. Benallal et al., C. R. Mecanique 336 (2008).

  13. Rapid Prototyping of wax foundry models in an incremental process

    Directory of Open Access Journals (Sweden)

    B. Kozik

    2011-04-01

    Full Text Available The paper presents an analysis incremental methods of creating wax founding models. There are two methods of Rapid Prototypingof wax models in an incremental process which are more and more often used in industrial practice and in scientific research.Applying Rapid Prototyping methods in the process of making casts allows for acceleration of work on preparing prototypes. It isespecially important in case of element having complicated shapes. The time of making a wax model depending on the size and the appliedRP method may vary from several to a few dozen hours.

  14. Quantitative trait loci controlling amounts and types of epicuticular waxes in onion

    Science.gov (United States)

    Natural variation exists in onion (Allium cepa L.) for amounts and types of epicuticular waxes on leaves. Wild-type waxy onion possesses copious amounts of these waxes, while the foliage of semi-glossy and glossy phenotypes accumulate significantly less wax. Reduced amounts of epicuticular waxes hav...

  15. Properties of cookies made with natural wax-vegetable oil organogels

    Science.gov (United States)

    Organogels prepared with a natural wax and a vegetable oil were examined as alternatives to a commercial margarine in cookie. To investigate effects of wax and vegetable oil on properties of cookie dough and cookies, organogels prepared from four different waxes including sunflower wax, rice bran wa...

  16. Oil-structuring characterization of natural waxes in canola oil oleogels: Rheological, thermal, and oxidative properties

    Science.gov (United States)

    Natural waxes (candelilla wax, carnauba wax, and beeswax) were utilized as canola oil structurants to produce oleogels and their physicochemical properties were evaluated from rheological, thermal, and oxidative points of view. The oleogels with candelilla wax exhibited the highest hardness, followe...

  17. Structure and Biosynthesis of Branched Wax Compounds on Wild Type and Wax Biosynthesis Mutants of Arabidopsis thaliana.

    Science.gov (United States)

    Busta, Lucas; Jetter, Reinhard

    2017-06-01

    The cuticle is a waxy composite that protects the aerial organs of land plans from non-stomatal water loss. The chemical make-up of the cuticular wax mixture plays a central role in defining the water barrier, but structure-function relationships have not been established so far, in part due to gaps in our understanding of wax structures and biosynthesis. While wax compounds with saturated, linear hydrocarbon tails have been investigated in detail, very little is known about compounds with modified aliphatic tails, which comprise substantial portions of some plant wax mixtures. This study aimed to investigate the structures, abundances and biosynthesis of branched compounds on the species for which wax biosynthesis is best understood: Arabidopsis thaliana. Microscale derivatization, mass spectral interpretation and organic synthesis identified homologous series of iso-alkanes and iso-alcohols on flowers and leaves, respectively. These comprised approximately 10-15% of wild type wax mixtures. The abundances of both branched wax constituents and accompanying unbranched compounds were reduced on the cer6, cer3 and cer1 mutants but not cer4, indicating that branched compounds are in part synthesized by the same machinery as unbranched compounds. In contrast, the abundances of unbranched, but not branched, wax constituents were reduced on the cer2 and cer26 mutants, suggesting that the pathways to both types of compounds deviate in later steps of chain elongation. Finally, the abundances of branched, but not unbranched, wax compounds were reduced on the cer16 mutant, and the (uncharacterized) CER16 protein may therefore be controlling the relative abundances of iso-alkanes and iso-alcohols on Arabidopsis surfaces. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Characterization and chemical composition of epicuticular wax from banana leaves grown in Northern Thailand

    Directory of Open Access Journals (Sweden)

    Suporn Charumanee

    2017-08-01

    Full Text Available This study aimed to investigate the physicochemical properties and chemical composition of epicuticular wax extracted from leaves of Kluai Namwa, a banana cultivar which is widely grown in Northern Thailand. Its genotype was identified by a botanist. The wax was extracted using solvent extraction. The fatty acid profiles and physicochemical properties of the wax namely melting point, congealing point, crystal structures and polymorphism, hardness, color, and solubility were examined and compared to those of beeswax, carnauba wax and paraffin wax. The results showed that the genotype of Kluai Namwa was Musa acuminata X M. balbisiana (ABB group cv. Pisang Awak. The highest amount of wax extracted was 274 μg/cm2 surface area. The fatty acid composition and the physicochemical properties of the wax were similar to those of carnauba wax. It could be suggested that the banana wax could be used as a replacement for carnauba wax in various utilizing areas.

  19. CARNAUBA WAX USED AS AN HYDROPHOBIC AGENT FOR EXPANDED VERMICULITE

    Directory of Open Access Journals (Sweden)

    M.A.F. Melo

    1998-03-01

    Full Text Available This work deals with the use of carnauba wax as an expansion and hydrophobicity agent for vermiculite, to be utilized in the sorption process of oil in water. Evaluation of the system (oil-water-hydrophobic vermiculite submersion percentage was considered in assessing the performance of vermiculite in comparison to a Mexican turf. Carnauba wax seems to be more efficient in both fresh and salt waters.

  20. The Acyl Desaturase CER17 Is Involved in Producing Wax Unsaturated Primary Alcohols and Cutin Monomers1[OPEN

    Science.gov (United States)

    Yang, Xianpeng; Zhao, Huayan; Kosma, Dylan K.; Dyer, John M.; Li, Rongjun; Liu, Xiulin; Wang, Zhouya; Jenks, Matthew A.

    2017-01-01

    We report n-6 monounsaturated primary alcohols (C26:1, C28:1, and C30:1 homologs) in the cuticular waxes of Arabidopsis (Arabidopsis thaliana) inflorescence stem, a class of wax not previously reported in Arabidopsis. The Arabidopsis cer17 mutant was completely deficient in these monounsaturated alcohols, and CER17 was found to encode a predicted ACYL-COENZYME A DESATURASE LIKE4 (ADS4). Studies of the Arabidopsis cer4 mutant and yeast variously expressing CER4 (a predicted fatty acyl-CoA reductase) with CER17/ADS4, demonstrated CER4’s principal role in synthesis of these monounsaturated alcohols. Besides unsaturated alcohol deficiency, cer17 mutants exhibited a thickened and irregular cuticle ultrastructure and increased amounts of cutin monomers. Although unsaturated alcohols were absent throughout the cer17 stem, the mutation’s effects on cutin monomers and cuticle ultrastructure were much more severe in distal than basal stems, consistent with observations that the CER17/ADS4 transcript was much more abundant in distal than basal stems. Furthermore, distal but not basal stems of a double mutant deficient for both CER17/ADS4 and LONG-CHAIN ACYL-COA SYNTHETASE1 produced even more cutin monomers and a thicker and more disorganized cuticle ultrastructure and higher cuticle permeability than observed for wild type or either mutant parent, indicating a dramatic genetic interaction on conversion of very long chain acyl-CoA precursors. These results provide evidence that CER17/ADS4 performs n-6 desaturation of very long chain acyl-CoAs in both distal and basal stems and has a major function associated with governing cutin monomer amounts primarily in the distal segments of the inflorescence stem. PMID:28069670

  1. Esters with water esters 2-c to 6-c

    CERN Document Server

    Getzen, F W; Hefter, G T; Maczynski, Andrzej

    1992-01-01

    This volume is the first of two devoted to esters and water. It includes solubility data for binary systems containing an ester and water up to the end of 1988. The critical evaluations were all prepared by one author and an introductory section has been included to elaborate the philosophy and methodology followed in the evaluations.

  2. Carboxylic ester hydrolases from hyperthermophiles

    NARCIS (Netherlands)

    Levisson, M.; Oost, van der J.; Kengen, S.W.M.

    2009-01-01

    Carboxylic ester hydrolyzing enzymes constitute a large group of enzymes that are able to catalyze the hydrolysis, synthesis or transesterification of an ester bond. They can be found in all three domains of life, including the group of hyperthermophilic bacteria and archaea. Esterases from the

  3. [Sorption of 1-naphthol to plant cuticular waxes with different states].

    Science.gov (United States)

    Chen, Bao-liang; Zhou, Dan-dan; Li, Yun-gui; Zhu, Li-zhong

    2008-06-01

    Wax components are ubiquitous in natural environments (such as plant and soil) and play a significant role in sorption of organic contaminants. To elucidate their sorption characteristics, cuticular waxes were isolated from the fruits of apple by organic solvent extraction method, and then the isolated-wax was reconstructed on montmorillonite with different loadings. Sorption behaviors of one polar organic pollutant, 1-naphthol, to isolated-wax, reconstructed-wax, and cuticle-associated-wax samples were compared by batch sorption method. Sorption properties of wax-montmorillonite complexes dependent on different wax-loadings were also investigated. Isotherms of 1-naphthol to wax samples were nonlinear, and fitted well with Freundlich equation. Although sorption of wax in the plant cuticle was weakened by other components of cuticle, its contribution to whole sorption of the cuticle increased with solute aqueous equilibrium concentration. Sorption coefficients at three equilibrium concentrations (1, 10, 100 microg/mL) were calculated, depending on solute concentrations and wax-loadings. Sorption coefficients normalized organic carbon contents (Koc) decreased with the increase of solute aqueous concentration. At low solute aqueous concentration, Koc values increased with the wax-loading increasing, reached maximum, and then decreased. At high solute aqueous concentration, Koc values were almost independent on wax-loadings. These observations indicated that partition was the dominant mechanism at high solute concentration, while specific interactions were involved as additional mechanisms at low solute concentration. Koc values of wax components in different states were in the order of reconstructed-wax (321.2) > isolated-wax (190.4) > cuticular-attached-wax (128.4), suggested that the sorption capability of wax was promoted once they were input into soil environment and then coated on mineral surface.

  4. Unheimlich. From Wax Figures to the Uncanny Valley

    Directory of Open Access Journals (Sweden)

    Pietro Conte

    2012-01-01

    Full Text Available In his pioneering History of Portraiture in Wax, Julius von Schlosser traced back the age-old history of a material which at that time seemed to be already antiquated, if not obsolete. Wax sculptures were rejected and ousted from art history because of their excessive similarity and adherence to models. One hundred years later, however, hyperrealism got its revenge with Maurizio Cattelan’s celebrated hanging children. Moving from that controversial artwork and focusing on the heated polemics over it, my paper will address the question of the well-known Unheimlichkeit of wax figures, investigated by Ernst Jentsch and Sigmund Freud in the early Twentieth Century and nowadays becoming increasingly topical thanks to the recent debate about the existence and nature of the so called Uncanny Valley.

  5. Fungal contamination of paraffin wax blocks in a pathology archive.

    Science.gov (United States)

    Müller, K; Ellenberger, C; Aupperle, H; Schmäschke, R; Scheller, R; Wittenbrink, M M; Schoon, H-A

    2011-01-01

    While searching for paraffin wax blocks for research purposes in our archive we detected numerous larval and some dead adult moths. Some wax blocks were riddled with a white-brown crumbling substance. The entire archive was checked and profoundly-infested blocks were separated from unaffected blocks. Mycological and parasitological investigations were performed. Fungi were identified by culture and polymerase chain reaction, which revealed high sequence homology to six different fungal species. The moths were determined to be Nemapogon personellus. A total of 8,484 wax blocks had to be removed from the archive and destroyed. Pathologists should be alerted to the importance of checking the humidity of the air where archival material is stored. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Sintesis Metil Ester Sulfonat Dari Asam Stearat Dan Metil Ester Sulfonat Dari Asam Oleat

    OpenAIRE

    Samosir, Yustina

    2011-01-01

    The Synthesis of Methyl Ester Sulfonate (MES) from stearic acid and from oleic acid through the stages of esterification reaction, that are esterification from stearic acid and oleic acid that forms methyl ester stearic acid and methyl ester oleic acid next stage was sulfonating the two of methyl esters to form a methyl ester sulfonate stearic acid and methyl ester oleic acid sulfonate. Furthermore, both fatty acid methyl ester sulfonate is neutralized with NaOH to obtain sulfonate salt. ...

  7. Cannabis-induced psychosis associated with high potency "wax dabs".

    Science.gov (United States)

    Pierre, Joseph M; Gandal, Michael; Son, Maya

    2016-04-01

    With mounting evidence that the risk of cannabis-induced psychosis may be related to both dose and potency of tetrahydrocannbinol (THC), increasing reports of psychosis associated with cannabinoids containing greater amounts of THC are anticipated. We report two cases of emergent psychosis after using a concentrated THC extract known as cannabis "wax," "oil," or "dabs" raising serious concerns about its psychotic liability. Although "dabbing" with cannabis wax is becoming increasingly popular in the US for both recreational and "medicinal" intentions, our cases raise serious concerns about its psychotic liability and highlight the importance of understanding this risk by physicians recommending cannabinoids for purported medicinal purposes. Published by Elsevier B.V.

  8. Production of long chain alkyl esters from carbon dioxide and electricity by a two-stage bacterial process.

    Science.gov (United States)

    Lehtinen, Tapio; Efimova, Elena; Tremblay, Pier-Luc; Santala, Suvi; Zhang, Tian; Santala, Ville

    2017-11-01

    Microbial electrosynthesis (MES) is a promising technology for the reduction of carbon dioxide into value-added multicarbon molecules. In order to broaden the product profile of MES processes, we developed a two-stage process for microbial conversion of carbon dioxide and electricity into long chain alkyl esters. In the first stage, the carbon dioxide is reduced to organic compounds, mainly acetate, in a MES process by Sporomusa ovata. In the second stage, the liquid end-products of the MES process are converted to the final product by a second microorganism, Acinetobacter baylyi in an aerobic bioprocess. In this proof-of-principle study, we demonstrate for the first time the bacterial production of long alkyl esters (wax esters) from carbon dioxide and electricity as the sole sources of carbon and energy. The process holds potential for the efficient production of carbon-neutral chemicals or biofuels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Esters van tetrathioorthokiezelzuur en tetrathioorthogermaniumzuur

    NARCIS (Netherlands)

    Stienstra, Folkert Jans

    1934-01-01

    The germaniun tetrachloride required was prepared from the mineral germanite. For this a simpler method was elaborated. For the preparation of the esters of tetrathioorthosilicic acid and tetrathioorthogermanic acid, silicon tetrachloride and germanium tetrachloride were made to react with a

  10. Fumaric acid esters.

    Science.gov (United States)

    Rostami Yazdi, Martin; Mrowietz, Ulrich

    2008-01-01

    Several clinical studies have shown that systemic therapy with fumaric acid esters (FAEs) in patients with moderate to severe psoriasis is effective and has a good long-term safety profile. For therapeutic use, tablets with a defined mixture of FAEs (dimethylfumarate [DMF] and three different salts of monoethylfumarate) are registered in Germany. There is evidence that DMF is the most essential component in this formulation with an antipsoriatic effect. Currently, there are few data on the pharmacokinetics of fumarates in human beings. DMF seems to act as a prodrug for its main metabolite: monomethylfumarate. This hypothesis was supported by the observation that only monomethylfumarate was detected in the plasma of human beings after the oral administration of FAEs. FAEs have been tested in different biological assays, and effects such as inhibition of the nuclear factor kappa B pathway or induction of apoptosis by DMF have been described. For these data, the role of DMF as a modulator of intracellular glutathione plays an important role.

  11. Epicuticular waxes on onion leaves and associated resistance to onion thrips

    Science.gov (United States)

    Natural variation exists for amounts and types of epicuticular waxes on onion foliage. Wild-type onion possesses copious amounts of these waxes and is often referred to as “waxy”. The recessively inherited “glossy” phenotype has significantly less wax relative to waxy types and shows resistance to o...

  12. Variation for epicuticular waxes on onion foliage and impacts on numbers of onion thrips

    Science.gov (United States)

    Natural variation exists in onion for amounts of epicuticular waxes on foliage, and plants with lower amounts of these waxes suffer less damage from the insect pest Thrips tabaci (thrips). Wild-type onion possesses copious amounts of epicuticular waxes and is often referred to as “waxy”. The recessi...

  13. ASPHALT-RESIN-WAX DEPOSITS ANALYSIS WITH PETROLEUM REFINERY EQUIPMENT USAGE

    Directory of Open Access Journals (Sweden)

    Nadejda Bondar

    2013-12-01

    Full Text Available The methodology and analysis of wax deposits formed in-water-cooling tower, cistern and tank from wax petroleum were developed. It was shown, that deposits consist of organic (>90% and inorganic components – the first one was enriched by high molecular wax hydrocarbons, the second one – by mechanical impurities. The methods of deposits utilization were proposed

  14. Hyperspectral visible-near infrared imaging for the detection of waxed rice

    Science.gov (United States)

    Zhao, Mantong

    2014-11-01

    Presently, unscrupulous traders in the market use the industrial wax to wax the rice. The industrial wax is a particularly hazardous substance. Visible-near infrared hyperspectral images (400-1,000 nm) can be used for the detection of the waxed rice and the non-waxed rice. This study was carried out to find effective testing methods based on the visible-near infrared imaging spectrometry to detect whether the rice was waxed or not. An imaging spectroscopy system was assembled to acquire hyperspectral images from 80 grains of waxed rice and 80 grains of non-waxed rice over visible and near infrared spectral region. Spectra of 100 grains of rice were analyzed by principal component analysis (PCA) to extract the information of hyperspectral images. PCA provides an effective compressed representation of the spectral signal of each pixel in the spectral domain. We used PCA to acquire the effective wavelengths from the spectra. Based on the effective wavelengths, the predict models were set up by using partial least squares (PLS) analysis and linear discriminant analysis (LDA). Also, compared with the PLS of 80% for the waxed rice and 86.7% for the non-waxed rice detection rate, LDA gives 93.3% and 96.7% detection rate. The results demonstrated that the LDA could detect the waxed rice better, while illustrating the hyperspectral imaging technique with the visible-near infrared region could be a reliable method for the waxed rice detection.

  15. Water vapor barrier and sorption properties of edible films from pullulan and rice wax.

    Science.gov (United States)

    Edible films were prepared by using various ratios of pullulan and rice wax. Freestanding composite films were obtained with up to 46.4% rice wax. Water vapor barrier properties of the film were improved with increased addition of rice wax. Moisture sorption isotherms were also studied to examine...

  16. Antimicrobial activity in the egg wax of the tick Amblyomma hebraeum (Acari: Ixodidae) is associated with free fatty acids C16:1 and C18:2.

    Science.gov (United States)

    Yu, Zhijun; Thomson, Euan L S; Liu, Jingze; Dennis, Jonathan J; Jacobs, René L; Kaufman, W Reuben

    2012-12-01

    Untreated eggs of the tick Amblyomma hebraeum Koch (Acari: Ixodidae) exhibited antimicrobial activity (AMA) against Gram-negative but not Gram-positive bacteria; eggs denuded of wax by solvent extraction showed no AMA. The unfractionated egg wax extract, however, showed AMA against Gram-positive but not Gram-negative bacteria, as also shown by Arrieta et al. (Exp Appl Acarol 39: 297-313, 2006). In this study we partitioned the egg wax into various fractions, using a variety of techniques, analyzed their compositions, and tested them for AMA. The crude aqueous extract exhibited AMA. However, although more than 30 metabolites were identified in this extract by nuclear magnetic resonance analysis, none of them seemed likely to be responsible for the observed AMA. In the crude organic extract, cholesterol esters were the most abundant lipids, but were devoid of AMA. Fatty acids (FAs), with chain lengths between C13 and C26 were the next most abundant lipids. After lipid fractionation and gas chromatography/mass spectroscopy, free FAs, especially C16:1 and C18:2, accounted for most of the AMA in the organic extract. The material responsible for AMA in the crude aqueous extract remains unidentified. No AMA was detected in the intracellular contents of untreated eggs.

  17. Hearing loss due to Wax Impaction. | Adobamen | Nigerian Quarterly ...

    African Journals Online (AJOL)

    Methods: Patients who met the inclusion criteria for the study were enrolled and Pure Tone Audiometry (PTA) threshold for each ear with wax impaction was determined at 250Hz, 500Hz, 1KHz, 2KHz, 4KHz and 8KHz by air conduction, Also bone conduction measurements were obtained at 500Hz, 1KHz, 2KHz and 4KHz.

  18. Influence of Different Waxes on the Physical Properties of Linear ...

    African Journals Online (AJOL)

    The influence of three different waxes on the thermal and mechanical properties of linear low-density polyethylene (LLDPE) was investigated. The samples were prepared through melt blending in a Brabender mixer. The thermal properties of the samples were determined using differential scanning calorimetry (DSC) and ...

  19. Variation for epicuticular waxes and thrips resistance in onion

    Science.gov (United States)

    Onion thrips (Thrips tabaci) and thrips-vectored Iris Yellow Spot Virus (IYSV) routinely cause significant losses to the bulb and seed crops of onion. Both pests have become more problematic as global temperatures rise. Natural variation exists in onion for amounts and types of epicuticular waxes on...

  20. wax matrix tablets and its implication on dissolution prof

    African Journals Online (AJOL)

    The matrix tablets were formed by compressing the wax matrix granules at a constant load (30 arbitrary units on the load scale). The tablets were evaluated for tablet tensile strength, packing fraction, friability and in vitro dissolution profile. The dissolution data were analysed with different mathematical models namely zero.

  1. Leaf waxes in litter and topsoils along a European transect

    Czech Academy of Sciences Publication Activity Database

    Schäfer, I. K.; Lanny, V.; Franke, J.; Eglinton, T. I.; Zech, M.; Vysloužilová, Barbora; Zech, R.

    2016-01-01

    Roč. 2, č. 4 (2016), s. 551-564 ISSN 2199-3971 Institutional support: RVO:67985912 Keywords : leaf waxes * soils Subject RIV: AC - Archeology, Anthropology, Ethnology http://www.soil-journal.net/2/551/2016/soil-2-551-2016.pdf

  2. Release Characteristics of Diltiazem Hydrochloride Wax-Matrix ...

    African Journals Online (AJOL)

    Michael Horsfall

    osmotically “controlled” devices (Zentner et al.,. 1985; Muhammad et al., 1991). These methods are however very complicated and expensive since it requires the use of organic solvents as coating fluid. Moreover, these organic solvents are hazardous to the environment. Waxes have been used either as matrix former or as ...

  3. Gourds: Bitter, Bottle, Wax, Snake, Sponge and Ridge

    Science.gov (United States)

    Minor cucurbits include bitter gourd, bottle gourd, wax gourd, snake gourd, and sponge and ridge gourd, which are significant dietary sources of nutrients such as vitamin A and C, iron and calcium. These cucurbits are cultivated and marketed by smallholder farmers and remain important components of ...

  4. Preparation and Characterization of Sugar Cane Wax Microspheres ...

    African Journals Online (AJOL)

    HP

    associated with indomethacin adverse effects due to drug accumulation [8]. CONCLUSION. The test and reference formulations were bioequivalent based on both the in vitro and in vivo data obtained, Thus, indomethacin microspheres encapsulated in sugar wax microspheres by melt method showed good potential for ...

  5. The preservative efficacies of bemul-wax coatings in combination ...

    African Journals Online (AJOL)

    The capacity of developing countries for citrus fruits exportation is limited by the lack of adequate storage techniques. In studying this problem citrus sinensis Osbeck was treated with, a locally developed bemul-wax, calcium chloride dip, and a combination of the two. The treated fruits were assessed during four month low ...

  6. EPICUTICULAR WAX COMPOSITION OF SOME EUROPEAN SEDUM SPECIES

    NARCIS (Netherlands)

    STEVENS, JF; THART, H; BOLCK, A; ZWAVING, JH; MALINGRE, TM

    Epicuticular waxes from 30 species of Sedum and 2 species of Sempervivoideae, i.e. Aeonium spathulatum and Sempervivum nevadense, have been analysed by GC and GC-MS. The Sedum taxa examined were S. acre, S. album, S. series Alpestria (13 species), S. anglicum, S. brevifolium, S. litoreum, S. lydium,

  7. Wax Spreading in Paper under Controlled Pressure and Temperature.

    Science.gov (United States)

    Hong, Wei; Zhou, Jing; Kanungo, Mandakini; Jia, Nancy; Dinsmore, Anthony D

    2018-01-09

    This work describes a novel rapid method to fabricate high-resolution paper-based microfluidic devices using wax-ink-based printing. This study demonstrates that both temperature and pressure are important knobs in controlling the device resolution. High-resolution lines and patterns were obtained by heating the paper asymmetrically from one side up to 110 °C while applying pressure up to 49 kPa. Starting with wax lines with an initial width of 130 μm, we achieve a thorough penetration through a 190 μm-thick paper with lateral spreading on the front as narrow as 90 μm. The role of temperature and pressure are systematically studied and compared with the prediction of the Lucas-Washburn equation. We found that the temperature dependence of spreading can be explained by the viscosity change of the wax, according to the Lucas-Washburn equation. The pressure dependence deviates from Lucas-Washburn behavior because of compression of the paper. An optimal condition for achieving full depth penetration of the wax yet minimizing lateral spreading is suggested after exploring various parameters including temperature, pressure, and paper type. These findings could lead to a rapid roll-to-roll fabrication of high-resolution paper-based diagnostic devices.

  8. Characterization of Epoxy Composites Reinforced with Wax Encapsulated Microcrystalline Cellulose

    Directory of Open Access Journals (Sweden)

    Yuanfeng Pan

    2016-11-01

    Full Text Available The effect of paraffin wax encapsulated microcrystalline cellulose (EMC particles on the mechanical and physical properties of EMC/epoxy composites were investigated. It was demonstrated that the compatibility between cellulose and epoxy resin could be maintained due to partial encapsulation resulting in an improvement in epoxy composite mechanical properties. This work was unique because it was possible to improve the physical and mechanical properties of the EMC/epoxy composites while encapsulating the microcrystalline cellulose (MCC for a more homogeneous dispersion. The addition of EMC could increase the stiffness of epoxy composites, especially when the composites were wet. The 1% EMC loading with a 1:2 ratio of wax:MCC demonstrated the best reinforcement for both dry and wet properties. The decomposition temperature of epoxy was preserved up to a 5% EMC loading and for different wax:MCC ratios. An increase in wax encapsulated cellulose loading did increase water absorption but overall this absorption was still low (<1% for all composites.

  9. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery

    OpenAIRE

    Attard, Thomas M.; Con Robert McElroy; Hunt, Andrew J.

    2015-01-01

    To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be €88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take int...

  10. Radiotherapic Valuation of Paraffin Wax for Patients with Oral Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Na, Kyung Su; Seo, Seuk Jin; Lee, Je Hee; Yoo, Sook Heun [Dept. of Radiation Oncology, Seoul National University Hosdital, Seoul (Korea, Republic of)

    2011-03-15

    This study is designed to investigate radiotherapic valuation of Paraffin Wax, which is newly formed for this study and generally utilized in dentistry, and Mouth Piece and Putty impression, which are commonly used in radiotherapy, for oral cavity as a compensator. Each compensator was formed by 10 x 10 x 1 cm and measured radiation dose attenuation ratio with reference of water phantom which is made of tissue-equivalent materials. Two patients with oral cancer underwent DRR (Digitally Reconstructed Radiogrph) of Offline Review Program of Aria System and Portal vision for 5 times for each material to evaluate reproducibility by each filling materials. Moreover, MU (monitor unit) changes by dose absorption were considered in the case of inevitable implication of an filling materials in the range for radiotherapy. Radiation dose attenuation ratios were shown -0.7{approx}+3.7% for Mouth Piece, +0.21{approx}+0.39% for Paraffin Wax and -2.71{approx}-1.76% for Putty impression. Error ranges of reproducibility of positions were measured {+-}3 mm for Mouth Piece, {+-}2 mm for Paraffin Wax and {+-}2 mm for Putty impression. Difference of prescription MU from dose absorption with an filling material increased +7.8% (250 MU) in Putty impression and -0.9% (230 MU) in Paraffin Wax as converted into a percentage from the standard phantom, Water 232 MU. Dose reduction of boundary between cavity and tissue was observed for Mouth Piece. Mouth Piece also had low reproducibility of positions as it had no reflection of anatomy of oral cavity even though it was a proper material to separate Maxilla and Mandible during therapy. On the other hand, Putty impression was a suitable material to correctly re-position oral cavity as before. However, it risked normal tissues getting unnecessary over irradiation and it caused radiation dose decrease by -2.5% for 1cm volume in comparison of it of water phantom. Dose reduction in Paraffin Wax, Fat Tissue-Equivalent Material, was smaller than other

  11. Mechanical properties of carving wax with various Ca-bentolite filter composition

    Directory of Open Access Journals (Sweden)

    Widjijono Widjijono

    2009-09-01

    Full Text Available Background: The carving wax is used as a medium in dental anatomy study. This wax composes of many waxes and sometimes a filler is added. Carving wax is not sold in Indonesian market. Whereas the gradients of carving wax such as beeswax, paraffin and bentonite are abundant in Indonesia. Based on that fact, to make high quality and standard,the exact composition if this carving wax should be known. Purpose: The aim of this study was to investigate the effect of carving wax composition with Ca-bentonite filler on the melting point, hardness, and thermal expansion. Methods: Five carving wax compositions were made with paraffin, Ca-bentonite, carnauba wax, and beeswax in ratio (% weight: 50:20:25:5 (KI, 55:15:25:5 (KII, 60:10:25:5 (KIII, 65:5:25:5 (KIV, 70:0:25:5(KV. All components were melted, then poured into the melting point, hardness, and thermal expansion moulds (n = 5. Three carving wax properties were tested: melting point by melting point apparatus; hardness by penetrometer; thermal expansion by digital sliding caliper. The data were analyzed statistically using One-Way ANOVA and LSD0.05. Result: The Ca-bentonite addition influenced the melting point and thermal expansion of carving wax with significant differences between KI and other groups (p < 0.05. Ca-bentonite addition influenced the carving wax hardness and the mean differences among the groups were significant (p < 0.05. Conclusion: Ca-bentonite filler addition on the composition of carving wax influenced the physical and mechanical properties. The carving wax with high Ca-bentonite concentration had high melting point and hardness, but low thermal expansion.

  12. STEM, STEM Education, STEMmania

    Science.gov (United States)

    Sanders, Mark

    2009-01-01

    In this article, the author introduces integrative STEM (science, technology, engineering, and/or mathematics) education and discusses the importance of the program. The notion of integrative STEM education includes approaches that explore teaching and learning between/among any two or more of the STEM subject areas, and/or between a STEM subject…

  13. Surfactants and Desensitizing Wax Substitutes for TNT-Based Systems.

    Science.gov (United States)

    1994-10-01

    esters of fatty acids and higher alcohols. Associated with these esters may be one or more fatty acids, alcohols, ketones, sterols, lactones or...Craft type of catalysts (e.g.AlCI 3 , BF3, SbClI, H2SO4, etc.), hydrogenation to remove unsaturation , and reaction with maleic anhydride to give...Arizona Chemical Co. Lawter International, Inc. Witco Corp. Resinall Corp. Sartomer Co., Inc, i. Amides Amides derived from saturated or unsaturated

  14. Wax microfluidics light-addressable valve with multiple actuation

    Science.gov (United States)

    Díaz-González, M.; Boix, G.; Fernández-Sánchez, C.; Baldi, A.

    2017-05-01

    This work reports on the design, fabrication and performance of a novel light-actuated wax microvalve. This valve is capable of multiple-actuation (30 and 15 open-close cycles in air and water, correspondingly), shows a fast response (<=500 ms) and has a low energy-consumption per actuation (<=1 J). The valve is inherently latched in both open and close states and is leak-proof to at least 80 kPa. It is actuated (both open and close) by light pulses from an external LED. Many valves (< 100 cm2) can be easily integrated in a single chip with a wax microfluidics technology. Fabrication is based on a low-cost and fast prototyping process compatible with the presence of temperature sensitive biocomponents.

  15. Pharmacognostic Studies on the Stems of Argemone mexicana Linn ...

    African Journals Online (AJOL)

    Macroscopical, microscopical, chemo-microscopical and quantitative studies on the leaves of Argemone mexicana Linn (Fam. Papaveraceae) were carried out. Morphologically, the stem is of variable size, mostly light green in colour. There was presence of white substances (wax) at the surfaces and it's prickly in nature.

  16. Chemotaxonomic significance of distribution and stable carbon isotopic composition of long-chain alkanes and alkan-1-ols in C{sub 4} grass waxes

    Energy Technology Data Exchange (ETDEWEB)

    Rommerskirchen, F.; Plader, A. [Carl von Ossietzky University, Oldenburg (Germany). Institute of Chemistry and Biology of the Marine Environment; Eglinton, G. [Hanse Institute for Advanced Study, Delmenhorst (Germany); Chikaraishii, Yoshito [Japan Agency for Marine-Earth Science and Technology, Yokosuka (Japan). Institute for Research on Earth Evolution

    2006-10-15

    Grasses (Poaceae) are distributed across the world in broad latitudinal belts and are an important source of C4 biomass in the geological record of soils as well as lake and marine sediments. We examined long-chain leaf wax components of thirty-five C{sub 4} grasses of the subfamilies Aristidoideae, Chloridoideae and Panicoideae from the southern African grasslands and savannas and three C{sub 3} grasses of the subfamily Pooideae from Peru and Australia and review the relevant botanical, phytogeographic and leaf wax compositional background information. Contents, distribution patterns and molecular stable carbon isotopic compositions of long-chain n-alkanes (n-C{sub 27} to n-C{sub 35}) and n-alkan-1-ols (n-C{sub 22} to n-C{sub 32}) were used to estimate the chemotaxonomic relevance of wax signatures of whole plants, separately for different subfamilies and for members of the three C{sub 4} subtypes (NADP-ME, NAD-ME and PCK). Two grass species were separated into flower heads, leaves and stems and the parts analysed separately. Grass flowers contain remarkable amounts of short-chain n-alkanes, which may have a significant influence on the chemical signature of the whole plant, whereas n-alkanol distribution patterns exhibit no systematics. The stable carbon isotopic composition of both biomarker types in different plant parts is remarkably uniform. Chemotaxonomic differentiation was not possible on a species level based on whole plant samples, but was more successful for averages of subfamily and photosynthetic subtype data. Wax signatures of C{sub 4} grasses are generally distinguishable from those of C{sub 3} species by heavier isotopic values, higher contents of n-C{sub 31} and n-C{sub 33} alkanes and the abundance of the n-C{sub 32} n-alkanol, which is largely absent in C{sub 3} grass waxes. Especially the waxes of the NAD-ME and PCK C{sub 4}-subtype grasses, which thrive in extremely arid tropical and subtropical areas, contain high relative amounts of longer

  17. The proteomics of formalin-fixed wax-embedded tissue.

    Science.gov (United States)

    Vincenti, David Cilia; Murray, Graeme I

    2013-04-01

    Proteomics, which is the global analysis of protein expression in cells and tissues, has emerged over the last ten to fifteen years as a key set of technologies to improve our understanding of disease processes and to identify new diagnostic, prognostic and predictive disease biomarkers. Whilst most proteomic studies have been conducted on fresh frozen tissue, the continuous improvements in technical procedures for protein extraction and separation, coupled with increasingly powerful bioinformatics, have provided the opportunity for proteomic analysis to be conducted on formalin-fixed wax-embedded tissue. This potential advance should allow proteomic analysis to be performed on the extensive archives of clinically annotated formalin fixed wax embedded tissue blocks stored in pathology departments worldwide. In this review the main techniques and their limitations involved in proteomic analysis of formalin fixed wax embedded tissue will be outlined and examples of their successful application will be indicated. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  18. Ultrasound assisted manufacturing of paraffin wax nanoemulsions: process optimization.

    Science.gov (United States)

    Jadhav, A J; Holkar, C R; Karekar, S E; Pinjari, D V; Pandit, A B

    2015-03-01

    This work reports on the process optimization of ultrasound-assisted, paraffin wax in water nanoemulsions, stabilized by modified sodium dodecyl sulfate (SDS). This work focuses on the optimization of major emulsification process variables including sonication time, applied power and surfactant concentration. The effects of these variables were investigated on the basis of mean droplet diameter and stability of the prepared emulsion. It was found that the stable emulsion with droplet diameters about 160.9 nm could be formed with the surfactant concentration of 10 mg/ml and treated at 40% of applied power (power density: 0.61 W/ml) for 15 min. Scanning electron microscopy (SEM) was used to study the morphology of the emulsion droplets. The droplets were solid at room temperature, showing bright spots under polarized light and a spherical shape under SEM. The electrophoretic properties of emulsion droplets showed a negative zeta potential due to the adsorption of head sulfate groups of the SDS surfactant. For the sake of comparison, paraffin wax emulsion was prepared via emulsion inversion point method and was checked its intrinsic stability. Visually, it was found that the emulsion get separated/creamed within 30 min. while the emulsion prepared via ultrasonically is stable for more than 3 months. From this study, it was found that the ultrasound-assisted emulsification process could be successfully used for the preparation of stable paraffin wax nanoemulsions.

  19. Liquid Crystalline Thermosets from Ester, Ester-imide, and Ester-amide Oligomers

    Science.gov (United States)

    Dingemans, Theodorus J. (Inventor); Weiser, Erik S. (Inventor); St. Clair, Terry L. (Inventor)

    2009-01-01

    Main chain thermotropic liquid crystal esters, ester-imides, and ester-amides were prepared from AA, BB, and AB type monomeric materials and end-capped with phenylacetylene, phenylmaleimide, or nadimide reactive end-groups. The end-capped liquid crystal oligomers are thermotropic and have, preferably, molecular weights in the range of approximately 1000-15,000 grams per mole. The end-capped liquid crystaloligomers have broad liquid crystalline melting ranges and exhibit high melt stability and very low melt viscosities at accessible temperatures. The end-capped liquid crystal oli-gomers are stable forup to an hour in the melt phase. They are highly processable by a variety of melt process shape forming and blending techniques. Once processed and shaped, the end-capped liquid crystal oigomers were heated to further polymerize and form liquid crystalline thermosets (LCT). The fully cured products are rubbers above their glass transition temperatures.

  20. Epicuticular Wax Accumulation and Fatty Acid Elongation Activities Are Induced during Leaf Development of Leeks1

    Science.gov (United States)

    Rhee, Yoon; Hlousek-Radojcic, Alenka; Ponsamuel, Jayakumar; Liu, Dehua; Post-Beittenmiller, Dusty

    1998-01-01

    Epicuticular wax production was evaluated along the length of expanding leek (Allium porrum L.) leaves to gain insight into the regulation of wax production. Leaf segments from the bottom to the top were analyzed for (a) wax composition and load; (b) microsomal fatty acid elongase, plastidial fatty acid synthase, and acyl-acyl carrier protein (ACP) thioesterase activities; and (c) tissue and cellular morphological changes. The level of total wax, which was low at the bottom, increased 23-fold along the length of the leaf, whereas accumulation of the hentriacontan-16-one increased more than 1000-fold. The onset of wax accumulation was not linked to cell elongation but, rather, occurred several centimeters above the leaf base. Peak microsomal fatty acid elongation activity preceded the onset of wax accumulation, and the maximum fatty acid synthase activity was coincident with the onset. The C16:0- and C18:0-ACP-hydrolyzing activities changed relatively little along the leaf, whereas C18:1-ACP-hydrolyzing activity increased slightly prior to the peak elongase activity. Electron micrographic analyses revealed that wax crystal formation was asynchronous among cells in the initial stages of wax deposition, and morphological changes in the cuticle and cell wall preceded the appearance of wax crystals. These studies demonstrated that wax production and microsomal fatty acid elongation activities were induced within a defined and identifiable region of the expanding leek leaf and provide the foundation for future molecular studies. PMID:9501123

  1. Oil adsorption ability of three-dimensional epicuticular wax coverages in plants

    Science.gov (United States)

    Gorb, Elena V.; Hofmann, Philipp; Filippov, Alexander E.; Gorb, Stanislav N.

    2017-04-01

    Primary aerial surfaces of terrestrial plants are very often covered with three-dimensional epicuticular waxes. Such wax coverages play an important role in insect-plant interactions. Wax blooms have been experimentally shown in numerous previous studies to be impeding locomotion and reducing attachment of insects. Among the mechanisms responsible for these effects, a possible adsorption of insect adhesive fluid by highly porous wax coverage has been proposed (adsorption hypothesis). Recently, a great decrease in insect attachment force on artificial adsorbing materials was revealed in a few studies. However, adsorption ability of plant wax blooms was still not tested. Using a cryo scanning electron microscopy approach and high-speed video recordings of fluid drops behavior, followed by numerical analysis of experimental data, we show here that the three-dimensional epicuticular wax coverage in the waxy zone of Nepenthes alata pitcher adsorbs oil: we detected changes in the base, height, and volume of the oil drops. The wax layer thickness, differing in samples with untreated two-layered wax coverage and treated one-layered wax, did not significantly affect the drop behavior. These results provide strong evidence that three-dimensional plant wax coverages due to their adsorption capability are in general anti-adhesive for insects, which rely on wet adhesion.

  2. Synthesis of substituted 2-cyanoarylboronic esters

    DEFF Research Database (Denmark)

    Lysén, Morten; Hansen, Henriette M; Begtrup, Mikael

    2006-01-01

    The synthesis of substituted 2-cyanoarylboronic esters is described via lithiation/in situ trapping of the corresponding methoxy-, trifluoromethyl-, fluoro-, chloro-, and bromobenzonitriles. The crude arylboronic esters were obtained in high yields and purities and with good regioselectivities....

  3. Visualization of micromorphology of leaf epicuticular waxes of the rubber tree Ficus elastica by electron microscopy.

    Science.gov (United States)

    Kim, Ki Woo

    2008-10-01

    Ultrastructural aspects of leaf epicuticular waxes were investigated in Ficus elastica by scanning and transmission electron microscopy. Glossy leaves of the rubber tree were collected and subjected to different regimes of specimen preparation for surface observations. F. elastica leaves were hypostomatic and stomata were surrounded with a cuticular thickening that formed a rim. The most prominent epicuticular wax structures of F. elastica leaves included granules and platelets. Without fixation and metal coating, epicuticular wax structures could be discerned on the leaf surface by low-vacuum (ca. 7 Pa) scanning electron microscopy. In terms of delineation and retention of the structures, the combination of vapor fixation by glutaraldehyde and osmium tetroxide with subsequent gold coating provided the most satisfactory results, as evidenced by high resolution and sharp protrusions of epicuticular waxes. However, erosion of epicuticular wax edges was noted in the immersion fixed leaves, showing less elongated platelets, less distinct wax edges, and granule cracking. These results suggest that the vapor fixation procedure for demonstrating three-dimensional epicuticular wax structures would facilitate characterization of diverse types of waxes. Instances were noted where epicuticular waxes grew over neighboring epidermal ridges and occluded stomata. In cross sections, epicuticular waxes were observed above the cuticle proper and ranged approximately from 100 nm to 500 nm in thickness. The native leaf epicuticular waxes had many layers of different electron density that were oriented parallel to each other and parallel or perpendicular to the cuticle surface, implying strata of crystal growth. Such retention of native epicuticular wax structures could be achieved through the use of acrylic resin treated with less harsh dehydrants and mild heat polymerization, alleviating wax extraction during specimen preparations.

  4. Trimerization of Phenyl Cyanate Ester

    Science.gov (United States)

    Pallaka, Madhusudhan Reddy; Simon, Sindee L.

    2015-03-01

    The kinetics of phenyl cyanate ester trimerization is studied in the bulk using differential scanning calorimetry. Dynamic experiments for different heating rates are analyzed for the activation energy using the model-free Kissinger-Akahira-Sunose(KAS) isoconversion method. The activation energy and other kinetic parameters are also obtained by fitting the dynamic data to a first order autocatalytic reaction model, which well describes the experimental data. The activation energy obtained from the KAS isoconversion method (70.1 kJ/mol) is in good agreement with that obtained from the kinetic model (73.2 kJ/mol) and is much lower than the more bulky cyanate esters studied in our laboratory, which have activation energies of approximately 95 kJ/mol. In addition, the rate constant for the phenyl cyanate ester is one to two orders higher than the bulkier cyanate esters in the temperature range of 200 to 300°C. Further elucidation of the dynamic experiments revealed a strong dependence of the reaction kinetics on the sample weight. Future work aims to understand this finding.

  5. Regioselective Synthesis of Cellulose Ester Homopolymers

    Science.gov (United States)

    Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar

    2012-01-01

    Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...

  6. 40 CFR 721.2805 - Acrylate ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Acrylate ester. 721.2805 Section 721... Acrylate ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as an acrylate ester (PMN P-96-824) is subject to reporting under this...

  7. Crystallographic Analysis of Analogous Silicon and Carbon Containing Di(Cyanate Ester)s and Tri(Cyanate Ester)s

    Science.gov (United States)

    2017-05-29

    lander are made from M55J/cyanate ester composites • The solar panel supports on the MESSENGER space probe use cyanate ester composite tie layers...Distribution Unlimited. PA# 17275 Cyanate Esters Around the Solar System 3 Images: courtesy NASA (public release) • The science decks on the Mars Phoenix

  8. Stem Cells

    Science.gov (United States)

    Stem cells are cells with the potential to develop into many different types of cells in the body. ... the body. There are two main types of stem cells: embryonic stem cells and adult stem cells. Stem ...

  9. Catalytic Ester to Stannane Functional Group Interconversion via Decarbonylative Cross-Coupling of Methyl Esters

    KAUST Repository

    Yue, Huifeng

    2018-01-03

    An unprecedented conversion of methyl esters to stannanes was realized, providing access to a series of arylstannanes via nickel catalysis. Various common esters including ethyl, cyclohexyl, benzyl, and phenyl esters can undergo the newly developed decarbonylative stannylation reaction. The reaction shows broad substrate scope, can differentiate between different types of esters, and if applied in consecutive fashion, allows the transformation of methyl esters into aryl fluorides or biaryls via fluororination or arylation.

  10. Effect of waste wax and chain structure on the mechanical and physical properties of polyethylene

    Directory of Open Access Journals (Sweden)

    M.A. AlMaadeed

    2015-05-01

    The wax dispersion in the matrix strongly depends on the percentage of wax added to the polymer and the molecular structure of the polymer. It was found that increasing the wax content enhances the phase separation. LDPE undergoes less phase separation due to its highly branched structure composed of a network of short and long chain branches. The wax has no pronounced plasticising effect on the polymer. This is clearly manifested in LDPE as no change in the melting temperature occurred. LLDPE and HDPE were slightly affected by a high concentration of wax (30% and 40%. This is due to the non-uniform distribution of short chain branching along the LLDPE and HDPE main chains, which can interact with the wax structure.

  11. Characterization and chemical composition of epicuticular wax from banana leaves grown in Northern Thailand

    OpenAIRE

    Suporn Charumanee; Songwut Yotsawimonwat; Panee Sirisa-ard; Kiatisak Pholsongkram

    2017-01-01

    This study aimed to investigate the physicochemical properties and chemical composition of epicuticular wax extracted from leaves of Kluai Namwa, a banana cultivar which is widely grown in Northern Thailand. Its genotype was identified by a botanist. The wax was extracted using solvent extraction. The fatty acid profiles and physicochemical properties of the wax namely melting point, congealing point, crystal structures and polymorphism, hardness, color, and solubility were examin...

  12. STEM, STEM Education, STEMmania

    OpenAIRE

    Sanders, Mark E.

    2008-01-01

    A series of circumstances has once more created an opportunity for technology educators to develop and implement new integrative approaches to STEM education championed by STEM education reform doctrine over the past two decades.

  13. Using genetic transformation to produce enhanced levels of erucic acid and novel wax esters in Crambe abyssinica

    NARCIS (Netherlands)

    Qi, W.

    2014-01-01

    Crambe abyssinica (crambe) is een oliehoudend gewas dat grote potentie heeft als industrieel uitgangsmateriaal. In het onderzoek beschreven in dit proefschrift werd een solide transformatieprotocol ontwikkeld voor crambe. Om tegemoet te komen aan de eisen voor introductie in het milieu die de EU

  14. THE RÔLE OF THE "WAX" OF THE TUBERCLE BACILLUS IN ESTABLISHING DELAYED HYPERSENSITIVITY

    Science.gov (United States)

    Raffel, Sidney; Arnaud, Louis E.; Dukes, C. Dean; Huang, Jwo S.

    1949-01-01

    Guinea pigs sensitized with egg albumin along with the purified wax fraction of the human tubercle bacillus respond with delayed hypersensitive reactivity to the protein antigen. Previous publications have reported a similar activity of the wax with respect to tuberculoprotein and picryl chloride. The effect is not referable to an ordinary adjuvant activity of the bacillary wax, since antibody titers are not increased in animals which receive it, and since a known adjuvant, water-in-oil emulsion, has no effect with respect to the induction of delayed hypersensitivity. This report further extends the rôle of the tubercle bacillary wax in the induction of delayed hypersensitive states. PMID:18152339

  15. Lost-Wax Casting in Ancient China: New Discussion on Old Debates

    Science.gov (United States)

    Zhou, Weirong; Huang, Wei

    2015-07-01

    The possible use of lost-wax casting in China has long been a matter of controversy. Based on the study of pertinent ancient texts concerning the technical origins of lost-wax casting in China, direct examination of questioned ancient Chinese bronzes as well as definite lost-wax castings from both overseas and China, and modern production of objects using piece-mold casting, the authors point out their own conceptual ideas about ancient lost-wax casting as follows. First, the lost-wax casting technique does not have its earliest origins in ancient China but rather from the Sumerians in Mesopotamia, where it was predominantly used to cast small human and animal figures (statuettes). Next, some essential characteristics of the lost-wax casting technique can be identified from the point of view of a distortable soft starting model. The locally deformed shape of lost-wax castings is found to be variable. Finally, it is improper to consider the ease of extraction from the mold as the criterion for distinguishing lost-wax casting from piece-mold casting. It is therefore incorrect to conclude that the three-dimensional openwork decorations present on Chinese bronzes from the Spring and Autumn Period, and the Warring States Period, are fabricated using lost-wax castings.

  16. Intracuticular wax fixes and restricts strain in leaf and fruit cuticles.

    Science.gov (United States)

    Khanal, Bishnu Prasad; Grimm, Eckhard; Finger, Sebastian; Blume, Alfred; Knoche, Moritz

    2013-10-01

    This paper investigates the effects of cuticular wax on the release of strain and on the tensile properties of enzymatically isolated cuticular membranes (CMs) taken from leaves of agave (Agave americana), bush lily (Clivia miniata), holly (Ilex aquifolium), and ivy (Hedera helix) and from fruit of apple (Malus × domestica), pear (Pyrus communis), and tomato (Lycopersicon esculentum). Biaxial strain release was quantified as the decrease in CM disc area following wax extraction. Stiffness, maximum strain and maximum force were determined in uniaxial tensile tests using strips of CM and dewaxed CMs (DCMs). Biaxial strain release, stiffness, and maximum strain, but not maximum force, were linearly related to the amount of wax extracted. Apple CM has the most wax and here the effect of wax extraction was substantially accounted for by the embedded cuticular wax. Heating apple CM to 80°C melted some wax constituents and produced an effect similar to, but smaller than, that resulting from wax extraction. Our results indicate that wax 'fixes' strain, effectively converting reversible elastic into irreversible plastic strain. A consequence of 'fixation' is increased cuticular stiffness. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  17. Fumaric acid esters in dermatology

    OpenAIRE

    Uwe Wollina

    2011-01-01

    Fumaric acid esters (FAE) are substances of interest in dermatology. FAE exert various activities on cutaneous cells and cytokine networks. So far only a mixture of dimethylfumarate (DMF) and three salts of monoethylfumarate (MEF) have gained approval for the oral treatment of moderate-to-severe plaque-type psoriasis in Germany. DMF seems to be the major active component. There is evidence that FAE are not only effective and safe in psoriasis but granulomatous non-infectious diseases like gra...

  18. Industrial solvents analyzed on SolGel-WAX(TM)

    National Research Council Canada - National Science Library

    Angus Hibberd; Gerard Sharp; Dan DiFeo

    2002-01-01

    ... phase-bonding process in which the polyethylene glycol phase is encapsulated into a sol-gel matrix. The SolGel-WAX column, by the nature of the sol-gel bonding, is an extremely inert, low-bleed, high-temperature column. This inertness gives excellent peak shape of difficult-to-- analyze polar solvents. The high thermal stability gives a low-bleed column and therefore higher signal-to-noise ratio allowing lower detection limits, which is essential in many industrial processes. Also note the excellent separa...

  19. Evaluation of Wax Deposition and Its Control During Production of Alaska North Slope Oils

    Energy Technology Data Exchange (ETDEWEB)

    Tao Zhu; Jack A. Walker; J. Liang

    2008-12-31

    Due to increasing oil demand, oil companies are moving into arctic environments and deep-water areas for oil production. In these regions of lower temperatures, wax deposits begin to form when the temperature in the wellbore falls below wax appearance temperature (WAT). This condition leads to reduced production rates and larger pressure drops. Wax problems in production wells are very costly due to production down time for removal of wax. Therefore, it is necessary to develop a solution to wax deposition. In order to develop a solution to wax deposition, it is essential to characterize the crude oil and study phase behavior properties. The main objective of this project was to characterize Alaskan North Slope crude oil and study the phase behavior, which was further used to develop a dynamic wax deposition model. This report summarizes the results of the various experimental studies. The subtasks completed during this study include measurement of density, molecular weight, viscosity, pour point, wax appearance temperature, wax content, rate of wax deposition using cold finger, compositional characterization of crude oil and wax obtained from wax content, gas-oil ratio, and phase behavior experiments including constant composition expansion and differential liberation. Also, included in this report is the development of a thermodynamic model to predict wax precipitation. From the experimental study of wax appearance temperature, it was found that wax can start to precipitate at temperatures as high as 40.6 C. The WAT obtained from cross-polar microscopy and viscometry was compared, and it was discovered that WAT from viscometry is overestimated. From the pour point experiment it was found that crude oil can cease to flow at a temperature of 12 C. From the experimental results of wax content, it is evident that the wax content in Alaskan North Slope crude oil can be as high as 28.57%. The highest gas-oil ratio for a live oil sample was observed to be 619.26 SCF

  20. The benefits of Fischer-Tropsch waxes in synthetic petroleum jelly.

    Science.gov (United States)

    Bekker, M; Louw, N R; Jansen Van Rensburg, V J; Potgieter, J

    2013-02-01

    This article is an introduction and general discussion regarding the use of Fisher-Tropsch wax in petroleum jelly applications. Traditionally, petroleum jelly is prepared from a blend of microwax, paraffin wax and mineral oil that are all derived from crude oil. Sasol Wax has successfully prepared a petroleum jelly based on predominantly to fully synthetic Fisher-Tropsch wax. Sasol Wax was awarded a patent P53898ZP00-29 November 11 for a predominantly to fully synthetic petroleum jelly based on Fisher-Tropsch wax blends. The benefits of Fisher-Tropsch wax discussed in this article include the absence of aromatic compounds and polycyclic aromatic compounds in Fisher-Tropsch wax as well as the sustainable production that is possible with Fisher-Tropsch wax, as opposed to paraffin wax that may be affected by the closure of group I Base Oil plants. This article will be the first in a series of articles from the same authors, and follow-up articles will include solid-state nuclear magnetic resonance and crystallization studies to determine the influence of predominantly synthetic waxes on petroleum jelly network structures compared with more traditional mineral oil-derived petroleum jellies, final product performance and stability of synthetic petroleum jelly used in, for example, personal care lotions or creams. The influence of oxygenated compounds and product safety and rheological properties (including primary skin feel upon application and secondary skin feel after application) of synthetic petroleum jellies compared with traditional mineral oil-derived petroleum jellies are discussed. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  1. Properties of Cookies Made with Natural Wax-Vegetable Oil Organogels.

    Science.gov (United States)

    Hwang, Hong-Sik; Singh, Mukti; Lee, Suyong

    2016-05-01

    The aim of this study was to examine the feasibility of cookies in which the conventional margarine is replaced with an organogel of vegetable oil (VO) and natural wax. New cookies from VO organogels contain no trans fats and much less saturated fats than cookies made with a conventional margarine. To understand the effects of different kinds of waxes, organogels were prepared from 4 different waxes including sunflower wax (SW), rice bran wax (RBW), beeswax, and candelilla wax and properties of cookie dough and cookie were evaluated. To investigate the effects of different VOs on the properties of cookies, 3 VOs including olive oil, soybean oil and flaxseed oil representing oils rich in oleic acid (18:1), linoleic acid (18:2), and linolenic acid (18:3), respectively, were used. Both the wax and VO significantly affected properties of organogel such as firmness and melting behavior shown in differential scanning calorimetry. The highest firmness of organogel was observed with SW and flaxseed oil. Properties of dough such as hardness and melting behavior were also significantly affected by wax and VO while trends were somewhat different from those for organogels. SW and RBW provided greatest hardnesses to cookie dough. However, hardness, spread factor, and fracturability of cookie containing the wax-VO organogel were not significantly affected by different waxes and VOs. Several cookies made with wax-VO organogels showed similar properties to cookies made with a commercial margarine. Therefore, this study shows the high feasibility of utilization of the organogel technology in real foods such as cookies rich in unsaturated fats. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  2. Biomimetic synthesis of petuniasterone D via the epoxy ester[bond]ortho ester rearrangement.

    Science.gov (United States)

    Faraldos, Juan A; Giner, José-Luis

    2002-07-12

    The side chain of the insecticidal steroid petuniasterone D was synthesized by the biomimetic acid-catalyzed epoxy ester[bond]ortho ester rearrangement. In addition to the natural (22R,24R)-configuration of the side chain ortho ester, compounds bearing the epimeric (22R,24S)-, (22S,24R)-, and (22S,24S)- [3.2.1]-bicyclic ortho esters were also produced by stereospecific rearrangement of the corresponding isomeric epoxy esters. Functionalization of the steroid nucleus of the (22R,24R)-ortho ester completed the synthesis of the natural product.

  3. Phase behavior, structure and rheology of candelilla wax/fully hydrogenated soybean oil mixtures with and without vegetable oil.

    Science.gov (United States)

    Ramírez-Gómez, N O; Acevedo, N C; Toro-Vázquez, J F; Ornelas-Paz, J J; Dibildox-Alvarado, E; Pérez-Martínez, J D

    2016-11-01

    Vegetable oil organogelation is one of the most promising strategies to eliminate trans fatty acids in plastic fats. Organogels prepared with edible wax are stable at refrigerator and room temperature. Some functional properties (i.e., texture) of wax organogels can be improved by adding saturated triacylglycerols. Mixtures of fully hydrogenated soybean oil (FH) and candelilla wax (CW) were studied with and without the addition of high oleic safflower oil (HOSFO). Crystallization and melting behavior, X-ray diffraction, and crystalline microstructure of the mixtures were analyzed. The elastic modulus (G'), and the structural recovery after shear of the organogels were also assessed. Mixtures without HOSFO formed solid dispersions of CW and FH crystals, where up to ~10% CW crystals were incorporated into the FH crystal lattice. The vegetable oil solutions of FH/CW mixtures crystallized from the melt, developed mixed crystal networks composed of FH crystals in the β polymorph and CW in an orthorhombic subcell packing. As the systems crystallized in the most stable polymorph, only minor microstructural changes were shown along 28days of storage at 25°C. CW and FH crystals showed a synergistic effect on the elasticity of organogels. This was attributed to the large number FH crystals nucleated on the surface of CW crystals. The structural recovery after shear was superior for mixed organogels composed of CW platelets and grainy FH crystals compared to that of CW organogels. A recovery of up to 65.7% the G' of gels formed under static conditions was observed upon shearing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. The effect of varieties on cotton wax as it relates to cotton quality parameters

    Science.gov (United States)

    Cotton wax is one of the non-cellulosic components found on the surfaces of cotton. It is important in dyeing and processing quality. This investigation was carried out to study the yield of wax on the surface of cottons by performing two methods: Soxhlet extractions and accelerated solvent extracti...

  5. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery

    Directory of Open Access Journals (Sweden)

    Thomas M. Attard

    2015-07-01

    Full Text Available To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM for maize stover wax extraction was found to be €88.89 per kg of wax, with the fixed capital investment (FCI and utility costs (CUT contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of €10.87 per kg of wax (based on 27% combustion efficiency for electricity generation and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation. A sensitivity analysis study showed that utility costs (cost of electricity had the greatest effect on the COM.

  6. Economic Assessment of Supercritical CO2 Extraction of Waxes as Part of a Maize Stover Biorefinery.

    Science.gov (United States)

    Attard, Thomas M; McElroy, Con Robert; Hunt, Andrew J

    2015-07-31

    To date limited work has focused on assessing the economic viability of scCO2 extraction to obtain waxes as part of a biorefinery. This work estimates the economic costs for wax extraction from maize stover. The cost of manufacture (COM) for maize stover wax extraction was found to be € 88.89 per kg of wax, with the fixed capital investment (FCI) and utility costs (CUT) contributing significantly to the COM. However, this value is based solely on scCO2 extraction of waxes and does not take into account the downstream processing of the biomass following extraction. The cost of extracting wax from maize stover can be reduced by utilizing pelletized leaves and combusting the residual biomass to generate electricity. This would lead to an overall cost of € 10.87 per kg of wax (based on 27% combustion efficiency for electricity generation) and €4.56 per kg of wax (based on 43% combustion efficiency for electricity generation). A sensitivity analysis study showed that utility costs (cost of electricity) had the greatest effect on the COM.

  7. pH-sensitive wax emulsion copolymerization with acrylamide hydrogel using gamma irradiation for dye removal

    Science.gov (United States)

    Ghobashy, Mohamed Mohamady; Elhady, Mohamed., A.

    2017-05-01

    Emulsion polymerization is an efficient method for the production of new wax-hydrogel matrices of cetyl alcohol: stearic acid wax and acrylamide hydrogel using triethylamine (TEA) as an emulsifier. A cross-linking reaction occurred when a mixture of wax-hydrogel solution was irradiated with gamma rays at a dose of 20 kGy. The gelation percentage of the matrices (CtOH-StA/PAAm) was 86%, which indicates that a sufficiently high conversion occurred in these new wax-hydrogel matrices. The ability of PAAm and CtOH-StA/PAAm as an adsorbent for dye removal was investigated. The removal of three reactive dyes, namely Remazol Red (RR), Amido Black (AB), and Toluidine Blue (TB), from aqueous solutions depends on the pH of the dye solution. Removal efficiency was investigated by UV spectrophotometry, and the results showed the affinity of the wax hydrogel to adsorb TB was 98% after 320 min. Fourier transform infrared-attenuated total reflectance spectra confirmed the cross-linking process involved between the chains of wax and hydrogel; furthermore, scanning electron microscopy images showed that the wax and hydrogel were completely miscible to form a single matrix. Swelling measurements showed the high affinity of adsorbed dyes from aqueous solutions at different pH values to the wax-hydrogel network; the highest swelling values of 13.05 and 8.24 (g/g) were observed at pH 10 and 6, respectively

  8. Epicuticular wax on stomata of damaged silver fir trees (Abies alba Mili.

    Directory of Open Access Journals (Sweden)

    Tomislav Bačić

    2011-01-01

    Full Text Available Condition of epistomatal wax on the abaxial surface of the current and previous-year needles of damaged silver fir trees (Abies alba Mill., both from the polluted Risnjak and "clean" Donja Dobra sites in Gorski Kotar region, both influenced by pollutants coming from Europe, during two years, three times a year, were examined with Scanning Electron Microscope. In the course of time the wax tubules on the epistomatal rims of stomata in polluted, but also in "clean" needles surface, become fused and agglomerated rapidly to various extents of morphologically different types of amorphous wax crusts, primarily compact and particulate ones. This process begins very early, especially in polluted Risnjak site, and may be interpreted as a possible result of air pollution. However, the recrystalization, or production of new tubules, also appears relatively quickly in mostly cases. Quantitative estimations indicate a very large total amount of amorphous wax crusts in the current-year needles, and a very high percentage of the same wax in previous-year needles. Amorphous wax crusts cover stomatal pores, as well as the rims, disturbing the normal gas exchange. Statistically there is a signicant tendency of increase in wax degradation in the needles of the polluted site in comparison with those of the unpolluted one, but there is an insignificant wax degradation among the needles of damaged trees within each site. These results confirmed most of the research done in our preliminary report.

  9. Organogels of vegetable oil with plant wax – trans/saturated fat replacements

    Science.gov (United States)

    This featured article reviews recent advances on the development of trans fat-free, low saturated fat food products from organogels formed by a plant wax in a vegetable oil. Plant waxes are of great interest in this research area because they are obtained as by-products during the oil refining proce...

  10. Cross-linking of LDPE/wax Blends in the Presence of Dicumyl ...

    African Journals Online (AJOL)

    The analyses of cross-link density of the samples indicated that increased amounts of peroxide gives rise to more efficient cross-linking, but only the PE phase in the blends is cross-linked. The DSC results indicated that LDPE and wax are probably miscible in the crystalline phase at low wax concentrations, but at higher ...

  11. Evaluation of canola oil oleogels with candelilla wax as an alternative to shortening in baked goods

    Science.gov (United States)

    The oleogels of canola oil with candelilla wax were prepared and utilized as a shortening replacer to produce cookies with a high level of unsaturated fatty acids. The incorporation of candelilla wax (3 and 6% by weight) to canola oil produced the oleogels with solid-like properties. The firmness of...

  12. How polymer additives reduce the pour point of hydrocarbon solvents containing wax crystals.

    Science.gov (United States)

    Binks, Bernard P; Fletcher, Paul D I; Roberts, Noel A; Dunkerley, John; Greenfield, Hannah; Mastrangelo, Antonio; Trickett, Kieran

    2015-02-14

    We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax-solvent combinations, the measured variation of wax solubility with temperature is well predicted by ideal solution theory. The variation of pour point temperature as a function of the overall wax concentration is quantitatively modelled using the idea that, for each overall wax concentration, the pour point occurs at a temperature at which a critical volume fraction ϕ* of wax crystals has precipitated. Close to the pour point temperature, extraction and examination of the wax crystals show they consist of polydisperse, irregularly-shaped platelets with axial ratios (h/d, where h is the plate thickness and d is the plate long dimension) in the range 0.005-0.05. It is found that the measured ϕ* values corresponding to the pour point transitions are weakly correlated with the wax crystal axial ratios (h/d) for all wax-solvent-PPD polymer combinations. These results indicate that the pour point transition occurs at a volume fraction larger than the value at which the volumes of rotation of the platelet crystals overlap, i.e., 2.5(h/d) < ϕ* < 11(h/d). PPD polymers work, in part, by increasing the wax crystal axial ratio (h/d), thereby increasing ϕ* and reducing the pour point temperature. Since the PPD's ability to modify the wax crystal shape relies on its adsorption to the crystal-solution surface, it is anticipated and observed experimentally that optimum PPD efficacy is correlated with the difference between the wax and the polymer solubility boundary temperatures. This finding and the mechanistic insight gained here provide the basis for a simple and rapid screening test to identify candidate

  13. Effects of cuticular wax on the postharvest quality of blueberry fruit.

    Science.gov (United States)

    Chu, Wenjing; Gao, Haiyan; Chen, Hangjun; Fang, Xiangjun; Zheng, Yonghua

    2018-01-15

    The blueberry fruit has a light-blue appearance because its blue-black skin is covered with a waxy bloom. This layer is easily damaged or removed during fruit harvesting and postharvest handling. We investigated the effects of wax removal on the postharvest quality of blueberry fruit and their possible mechanisms. The removal of natural wax on the fruit was found to accelerate the postharvest water loss and decay, reduce the sensory and nutritional qualities, and shorten the shelf-life. Wax removal decreased the activities of antioxidant enzymes and contents of antioxidants, and accelerated accumulation of ROS and lipid peroxidation, especially at the later period of storage. Moreover, the organellar membrane structure was disrupted in fruit with wax removed. These results indicate that cuticular wax plays an important role in maintaining the postharvest quality and delaying fruit senescence. The results should improve our understanding for better preservation of postharvest quality of blueberry fruit. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Composition and morphology of cuticular wax in blueberry (Vaccinium spp.) fruits.

    Science.gov (United States)

    Chu, Wenjing; Gao, Haiyan; Cao, Shifeng; Fang, Xiangjun; Chen, Hangjun; Xiao, Shangyue

    2017-03-15

    The chemical composition and morphology of cuticular wax in mature fruit of nine blueberry cultivars were investigated using gas chromatography-mass spectrometry (GC-MS) and scanning electron microscope (SEM). Triterpenoids and β-diketones were the most prominent compounds, accounting for on average 64.2% and 16.4% of the total wax, respectively. Ursolic or oleanolic acid was identified as the most abundant triterpenoids differing in cultivars. Two β-diketones, hentriacontan-10,12-dione and tritriacontan-12,14-dione, were detected in cuticular wax of blueberry fruits for the first time. Notably, hentriacontan-10,12-dione and tritriacontan-12,14-dione were only detected in highbush (V. corymbosum) and rabbiteye (V. ashei) blueberries, respectively. The results of SEM showed that a large amount of tubular wax deposited on the surface of blueberry fruits. There was no apparent difference in wax morphology among the nine cultivars. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Ester Tuiksoo. Proua Suhkru kibedad päevad / Ester Tuiksoo ; interv. Piret Tali

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2005-01-01

    Põllumajandusminister Ester Tuiksoo, kellel peagi täitub ministri ametis aasta Euroopa Liidu suhkrutrahvist, maaettevõtlusest, põllumajandusest, Euroopa Liidu toetustest, ministri elu- ja teenistuskäigust. Lisa: Ester Tuiksoo

  16. Stereoselective synthesis of functionalized gamma-amino esters: azetidinium salts and epoxy esters.

    Science.gov (United States)

    Concellón, José M; Riego, Estela; Bernad, Pablo L

    2002-04-18

    Addition of several lithium ester enolates to chiral 1-aminoalkyl chloromethyl ketones 1 affords enantiomerically pure 3-hydroxyazetidinium salts 3 or 3-(1'-aminoalkyl)-3,4-epoxy esters 4, depending on the reaction conditions. [reaction: see text

  17. The effect of non-glaucousness, as conferred by Inhibitor of Wax 1, on physiology and yield of UK Wheat

    OpenAIRE

    Frizell-Armitage, Amelia

    2016-01-01

    Abstract As the first barrier to the external environment, the epicuticular waxes have a number of key roles in plant physiology. Although the wheat wild progenitors display a diversity of epicuticular wax phenotypes, the glaucous (visible wax) phenotype dominates cultivated varieties. However, the UK winter wheat variety Shamrock is unusual in that it exhibits a non-glaucous phenotype, conferred by the wild emmer gene Inhibitor of Wax 1 (Iw1). UK field trials with Shamrock associated a yi...

  18. Method of making a cyanate ester foam

    Science.gov (United States)

    Celina, Mathias C.; Giron, Nicholas Henry

    2014-08-05

    A cyanate ester resin mixture with at least one cyanate ester resin, an isocyanate foaming resin, other co-curatives such as polyol or epoxy compounds, a surfactant, and a catalyst/water can react to form a foaming resin that can be cured at a temperature greater than 50.degree. C. to form a cyanate ester foam. The cyanate ester foam can be heated to a temperature greater than 400.degree. C. in a non-oxidative atmosphere to provide a carbonaceous char foam.

  19. Fumaric acid esters in dermatology

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2011-01-01

    Full Text Available Fumaric acid esters (FAE are substances of interest in dermatology. FAE exert various activities on cutaneous cells and cytokine networks. So far only a mixture of dimethylfumarate (DMF and three salts of monoethylfumarate (MEF have gained approval for the oral treatment of moderate-to-severe plaque-type psoriasis in Germany. DMF seems to be the major active component. There is evidence that FAE are not only effective and safe in psoriasis but granulomatous non-infectious diseases like granuloma annulare, necrobiosis lipoidica and sarcoidosis. In vitro and animal studies suggest some activity in malignant melanoma as well.

  20. Fumaric acid esters in dermatology.

    Science.gov (United States)

    Wollina, Uwe

    2011-07-01

    Fumaric acid esters (FAE) are substances of interest in dermatology. FAE exert various activities on cutaneous cells and cytokine networks. So far only a mixture of dimethylfumarate (DMF) and three salts of monoethylfumarate (MEF) have gained approval for the oral treatment of moderate-to-severe plaque-type psoriasis in Germany. DMF seems to be the major active component. There is evidence that FAE are not only effective and safe in psoriasis but granulomatous non-infectious diseases like granuloma annulare, necrobiosis lipoidica and sarcoidosis. In vitro and animal studies suggest some activity in malignant melanoma as well.

  1. Understanding wax screen-printing: a novel patterning process for microfluidic cloth-based analytical devices.

    Science.gov (United States)

    Liu, Min; Zhang, Chunsun; Liu, Feifei

    2015-09-03

    In this work, we first introduce the fabrication of microfluidic cloth-based analytical devices (μCADs) using a wax screen-printing approach that is suitable for simple, inexpensive, rapid, low-energy-consumption and high-throughput preparation of cloth-based analytical devices. We have carried out a detailed study on the wax screen-printing of μCADs and have obtained some interesting results. Firstly, an analytical model is established for the spreading of molten wax in cloth. Secondly, a new wax screen-printing process has been proposed for fabricating μCADs, where the melting of wax into the cloth is much faster (∼5 s) and the heating temperature is much lower (75 °C). Thirdly, the experimental results show that the patterning effects of the proposed wax screen-printing method depend to a certain extent on types of screens, wax melting temperatures and melting time. Under optimized conditions, the minimum printing width of hydrophobic wax barrier and hydrophilic channel is 100 μm and 1.9 mm, respectively. Importantly, the developed analytical model is also well validated by these experiments. Fourthly, the μCADs fabricated by the presented wax screen-printing method are used to perform a proof-of-concept assay of glucose or protein in artificial urine with rapid high-throughput detection taking place on a 48-chamber cloth-based device and being performed by a visual readout. Overall, the developed cloth-based wax screen-printing and arrayed μCADs should provide a new research direction in the development of advanced sensor arrays for detection of a series of analytes relevant to many diverse applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. The Influence of Source Biases on Sedimentary Leaf Waxes and Their Stable Isotope Compositions

    Science.gov (United States)

    Diefendorf, A. F.; Freimuth, E. J.; Lowell, T. V.; Wiles, G. C.

    2015-12-01

    Leaf waxes and their carbon (δ13C) and hydrogen (δD) isotopic compositions are an important tool to understand past changes in paleoclimate and paleovegetation. Important recent advances in our understanding about the isotopic signal preserved in sedimentary leaf waxes have been inferred from studies made on individual modern plants. However, paleoreconstructions are based on sedimentary leaf waxes, which reflect mixing between multiple sources, such as ablated leaf waxes from nearby or from afar, wind blown leaf litter, and riverine transported leaf waxes. Each of these sources integrates leaf waxes from different species and growth forms, likely resulting in source-specific taphonomic biases on sedimentary leaf wax isotopes. To better understand source biases in sedimentary leaf waxes, we investigated n-alkanes and n-alkanoic acids and their carbon and hydrogen isotopes in vegetation and lake sediments at Brown's Lake and Bog, a 'simple' forested closed-basin lake in northeastern Ohio. Interestingly, we found that tree n-alkane δD varied substantially during the growing season, broadly tracking changes in source water composition. However, δD values of n-alkanes in the tree leaf litter did not match that of the most recent sedimentary n-alkanes. Instead, surface sediment n-alkane δD more closely matched that of the woody shrubs and grasses growing right around the lake. n-Alkanoic acid data is forthcoming. We are currently exploring lake sediment n-alkane accumulation rates against midwestern flux rates of wind blown leaf waxes from afar. Our preliminary results suggest that although studies made on individual leaves are indeed important, we may need to consider additional leaf wax sources that potentially influence sedimentary archives.

  3. Marginal adaptation of four inlay casting waxes on stone, titanium, and zirconia dies.

    Science.gov (United States)

    Michalakis, Konstantinos X; Kapsampeli, Vassiliki; Kitsou, Aikaterini; Kirmanidou, Yvone; Fotiou, Anna; Pissiotis, Argirios L; Calvani, Pasquale Lino; Hirayama, Hiroshi; Kudara, Yukio

    2014-07-01

    Different inlay casting waxes do not produce copings with satisfactory marginal accuracy when used on different die materials. The purpose of this study was to evaluate the marginal accuracy of 4 inlay casting waxes on stone dies and titanium and zirconia abutments and to correlate the findings with the degree of wetting between the die specimens and the inlay casting waxes. The inlay casting waxes tested were Starwax (Dentaurum), Unterziehwachs (Bredent), SU Esthetic wax (Schuler), and Sculpturing wax (Renfert). The marginal opening of the waxes was measured with a stereomicroscope on high-strength stone dies and on titanium and zirconia abutments. Photographic images were obtained, and the mean marginal opening for each specimen was calculated. A total of 1440 measurements were made. Wetting between die materials and waxes was determined after fabricating stone, titanium, and zirconia rectangular specimens. A calibrated pipette was used to place a drop of molten wax onto each specimen. The contact angle was calculated with software after an image of each specimen had been made with a digital camera. Collected data were subjected to a 2-way analysis of variance (α=.05). Any association between marginal accuracy and wetting of different materials was found by using the Pearson correlation. The wax factor had a statistically significant effect both on the marginal discrepancy (F=158.31, P<.001) and contact angle values (F=68.09, P<.001). A statistically significant effect of the die material factor both on the marginal adaptation (F=503.47, P<.001) and contact angle values (F=585.02, P<.001) was detected. A significant correlation between the marginal accuracy and the contact angle values (Pearson=0.881, P=.01) was also found. Stone dies provided wax copings with the best marginal integrity, followed by titanium and zirconia abutments. Unterziehwachs (Bredent), wax produced the best marginal adaptation on different die materials. A significant correlation was found

  4. Wax Precipitation Modeled with Many Mixed Solid Phases

    DEFF Research Database (Denmark)

    Heidemann, Robert A.; Madsen, Jesper; Stenby, Erling Halfdan

    2005-01-01

    The behavior of the Coutinho UNIQUAC model for solid wax phases has been examined. The model can produce as many mixed solid phases as the number of waxy components. In binary mixtures, the solid rich in the lighter component contains little of the heavier component but the second phase shows...... substantial amounts of the lighter component dissolved in the heavier solid. Calculations have been performed taking into account the recrystallization of the solid alkanes into a second solid form. The Coutinho UNIQUAC model has been used to describe the lower-temperature solid phases. The higher......-temperature mixed solid phase has been assumed to be either an ideal solution or to be described by Coutinho's Wilson activity coefficient model. This procedure accounts for more of the known behavior of mixed n-alkane solids. Comparison is also made with results assuming that all of the solid phases, both high...

  5. [For an interdisciplinary museology. The particular case of anatomical waxes].

    Science.gov (United States)

    Pirson, Chloé

    2009-01-01

    Nowadays, the anatomical models in three dimensions are often showed in Museums devoted to the History of Medicine. Due to their historical importance and the major role they played as scientific education tool, they are essentials to understand the heritage of the anatomical knowledge. Historically, within all materials used to cast the body, wax has been the most frequently used, so that the ceroplastical collection has become a part of the medical education before leading to a general public pedagogy. This paper has a double purpose. In one hand, it aims to survey the formal evolution and the uses of this production, from his creation on, in the other, to study this cultural heritage within the museology issue.

  6. Preparation of Spirocyclic β-Proline Esters

    DEFF Research Database (Denmark)

    Fjelbye, Kasper; Marigo, Mauro; Clausen, Rasmus Prætorius

    2017-01-01

    A series of novel N-Bn-protected spirocyclic β-proline esters were prepared using [3+2] cycloaddition and subsequently converted into their corresponding aldehydes. In addition, two novel N-Cbz-protected spirocyclic β-proline esters were prepared using intramolecular cyclization starting from sim...

  7. Molecular and Evolutionary Mechanisms of Cuticular Wax for Plant Drought Tolerance

    Directory of Open Access Journals (Sweden)

    Dawei Xue

    2017-04-01

    Full Text Available Cuticular wax, the first protective layer of above ground tissues of many plant species, is a key evolutionary innovation in plants. Cuticular wax safeguards the evolution from certain green algae to flowering plants and the diversification of plant taxa during the eras of dry and adverse terrestrial living conditions and global climate changes. Cuticular wax plays significant roles in plant abiotic and biotic stress tolerance and has been implicated in defense mechanisms against excessive ultraviolet radiation, high temperature, bacterial and fungal pathogens, insects, high salinity, and low temperature. Drought, a major type of abiotic stress, poses huge threats to global food security and health of terrestrial ecosystem by limiting plant growth and crop productivity. The composition, biochemistry, structure, biosynthesis, and transport of plant cuticular wax have been reviewed extensively. However, the molecular and evolutionary mechanisms of cuticular wax in plants in response to drought stress are still lacking. In this review, we focus on potential mechanisms, from evolutionary, molecular, and physiological aspects, that control cuticular wax and its roles in plant drought tolerance. We also raise key research questions and propose important directions to be resolved in the future, leading to potential applications of cuticular wax for water use efficiency in agricultural and environmental sustainability.

  8. Development of formulations and processes to incorporate wax oleogels in ice cream.

    Science.gov (United States)

    Zulim Botega, Daniele C; Marangoni, Alejandro G; Smith, Alexandra K; Goff, H Douglas

    2013-12-01

    The objective of this study was to investigate the influence of emulsifiers, waxes, fat concentration, and processing conditions on the application of wax oleogel to replace solid fat content and create optimal fat structure in ice cream. Ice creams with 10% or 15% fat were formulated with rice bran wax (RBW), candelilla wax (CDW), or carnauba wax (CBW) oleogels, containing 10% wax and 90% high-oleic sunflower oil. The ice creams were produced using batch or continuous freezing processes. Transmission electron microscopy (TEM) and cryo-scanning electron microscopy were used to evaluate the microstructure of ice cream and the ultrastructure of oleogel droplets in ice cream mixes. Among the wax oleogels, RBW oleogel had the ability to form and sustain structure in 15% fat ice creams when glycerol monooleate (GMO) was used as the emulsifier. TEM images revealed that the high degree of fat structuring observed in GMO samples was associated with the RBW crystal morphology within the fat droplet, which was characterized by the growth of crystals at the outer edge of the droplet. Continuous freezing improved fat structuring compared to batch freezing. RBW oleogels established better structure compared to CDW or CBW oleogels. These results demonstrate that RBW oleogel has the potential to develop fat structure in ice cream in the presence of GMO and sufficiently high concentrations of oleogel. © 2013 Institute of Food Technologists®

  9. Wax inhibitor based on ethylene vinyl acetate with methyl methacrylate and diethanolamine for crude oil pipeline

    Science.gov (United States)

    Anisuzzaman, S. M.; Abang, S.; Bono, A.; Krishnaiah, D.; Karali, R.; Safuan, M. K.

    2017-06-01

    Wax precipitation and deposition is one of the most significant flow assurance challenges in the production system of the crude oil. Wax inhibitors are developed as a preventive strategy to avoid an absolute wax deposition. Wax inhibitors are polymers which can be known as pour point depressants as they impede the wax crystals formation, growth, and deposition. In this study three formulations of wax inhibitors were prepared, ethylene vinyl acetate, ethylene vinyl acetate co-methyl methacrylate (EVA co-MMA) and ethylene vinyl acetate co-diethanolamine (EVA co-DEA) and the comparison of their efficiencies in terms of cloud point¸ pour point, performance inhibition efficiency (%PIE) and viscosity were evaluated. The cloud point and pour point for both EVA and EVA co-MMA were similar, 15°C and 10-5°C, respectively. Whereas, the cloud point and pour point for EVA co-DEA were better, 10°C and 10-5°C respectively. In conclusion, EVA co-DEA had shown the best % PIE (28.42%) which indicates highest percentage reduction of wax deposit as compared to the other two inhibitors.

  10. Triterpenoid profile of fruit and leaf cuticular waxes of edible honeysuckle Lonicera caerulea var. kamtschatica

    Directory of Open Access Journals (Sweden)

    Rafał Becker

    2017-03-01

    Full Text Available Edible honeysuckle (honeyberry Lonicera caerulea is becoming popular as a novel berry crop with several useful features such as early fruit ripening and exceptional hardiness, particularly resistance to pests and diseases as well as severe frosts in winter and droughts in summer. The triterpenoid profile of fruit and leaf cuticular waxes of edible honeysuckle (a Russian cultivar Chernichka was analyzed by GC-MS. The major compounds identified were the tetracyclic triterpenoids campesterol, cholesterol, cycloartanol, cycloart-23-ene-3,25-diol, 24-methylenecycloartanol (only in leaves, sitosterol, stigmasta-3,5-dien-7-one, and stigmasterol; and the pentacyclic triterpenes: α-amyrin, β-amyrin, hop-22(29-en-3-one, oleanolic acid, and ursolic acid. Several remarkable features of the analyzed triterpenoid contents were revealed, including the relatively low abundance of triterpenoids in fruit waxes (6.5% of wax extract compared to leaf waxes (22%, and a particularly high proportion of tetracyclic triterpenoids (tetracyclic to pentacyclic compound ratios of 4:1 in fruits and almost 7:1 in leaves. These rare features distinguish the triterpenoid profile of the cuticular waxes of L. caerulea var. kamtschatica from the majority of triterpenoid profiles in plant cuticular waxes investigated to date. To our knowledge, this is the first quantitative compositional study on triterpenoid compounds in the cuticular waxes of edible honeysuckle, supplementing the knowledge of cuticular triterpenoid diversity and distribution.

  11. Micromorphology of epicuticular wax structures of the garden strawberry leaves by electron microscopy: syntopism and polymorphism.

    Science.gov (United States)

    Kim, Ki Woo; Ahn, Jeong Joon; Lee, Joon-Ho

    2009-04-01

    Ultrastructural aspects of leaf epicuticular wax structures were investigated in the garden strawberry Fragariaxananassa by scanning and transmission electron microscopy. Both the adaxial and abaxial surfaces of two cultivars (Maehyang and Red Pearl) were collected and subjected to surface observations and ultrathin sections. The most prominent leaf epicuticular wax structures included membraneous platelets and angular rodlets. Most wax platelets were membraneous, and appeared to protrude from the surface at an acute angle. Angular rodlets were usually bent and had rather distinct facets in the abaxial surface of the two cultivars. Membraneous platelets were predominant on the adaxial surface of Maehyang, whereas the adaxial surface of Red Pearl was characterized by angular rodlets. However, both cultivars possessed angular rodlets on the abaxial surface, simultaneously. The combination of air-drying without vacuum and in-lens imaging of secondary electron signals with a field emission gun could impart the superb resolution at low electron dose with minimal specimen shrinkage. In vertical profiles of the leaf epidermis, epicuticular waxes were observed above the cuticle layer, and measured approximately as 50nm in thickness. The natural epicuticular waxes were seemingly mixtures of electron-dense microfibrils, and heterogeneous in shape on ultrathin sections. Distinct crystal-like strata could be hardly discernable in the wax structures. These results suggest that the garden strawberry has the nature of syntopism within one plant and polymorphism within the same species in the formation and occurrence of leaf epicuticular waxes.

  12. Accuracy of ringless casting and accelerated wax-elimination technique: a comparative in vitro study.

    Science.gov (United States)

    Prasad, Rahul; Al-Keraif, Abdulaziz Abdullah; Kathuria, Nidhi; Gandhi, P V; Bhide, S V

    2014-02-01

    The purpose of this study was to determine whether the ringless casting and accelerated wax-elimination techniques can be combined to offer a cost-effective, clinically acceptable, and time-saving alternative for fabricating single unit castings in fixed prosthodontics. Sixty standardized wax copings were fabricated on a type IV stone replica of a stainless steel die. The wax patterns were divided into four groups. The first group was cast using the ringless investment technique and conventional wax-elimination method; the second group was cast using the ringless investment technique and accelerated wax-elimination method; the third group was cast using the conventional metal ring investment technique and conventional wax-elimination method; the fourth group was cast using the metal ring investment technique and accelerated wax-elimination method. The vertical marginal gap was measured at four sites per specimen, using a digital optical microscope at 100× magnification. The results were analyzed using two-way ANOVA to determine statistical significance. The vertical marginal gaps of castings fabricated using the ringless technique (76.98 ± 7.59 μm) were significantly less (p castings fabricated using the conventional metal ring technique (138.44 ± 28.59 μm); however, the vertical marginal gaps of the conventional (102.63 ± 36.12 μm) and accelerated wax-elimination (112.79 ± 38.34 μm) castings were not statistically significant (p > 0.05). The ringless investment technique can produce castings with higher accuracy and can be favorably combined with the accelerated wax-elimination method as a vital alternative to the time-consuming conventional technique of casting restorations in fixed prosthodontics. © 2013 by the American College of Prosthodontists.

  13. Hearing and evasive behavior in the greater wax moth, Galleria mellonella (Pyralidae)

    DEFF Research Database (Denmark)

    Skals, Niels; Surlykke, Annemarie

    2000-01-01

    Greater wax moths (Galleria mellonella L., Pyraloidea) use ultrasound sensitive ears to detect clicking conspeci®cs and echolocating bats. Pyralid ears have four sensory cells, A1±4. The audiogram of G. mellonella has best frequency at 60 kHz with a threshold around 47 dB sound pressure level. A1...... and A2 have almost equal thresholds in contrast to noctuids and geometrids. A3 responds at + 12 to + 16 dB relative to the A1 threshold. The threshold data from the A-cells give no indication of frequency discrimination in greater wax moths. Tethered greater wax moths respond to ultrasound with short...

  14. [An unusual jugal abscess after third molar extraction: a complication of hemostatic wax].

    Science.gov (United States)

    Brignol, L; Guyot, L; Richard, O; Chossegros, C

    2007-04-01

    Bleeding is a common complication after third molar extraction. Hemostatic agents can be helpful in controlling intraoperative bleeding. Infection is another common complication. Horseley's wax is frequently used for bone surgery and less often for dental surgery. We report an unusual case of abscess formation in the jaw after third molar extraction. Surgical exploration of the abscess disclosed the presence of surgical wax in the center of a foreign body granuloma. We discuss the use of surgical wax and other local hemostatic agents and the subsequent risk of complications.

  15. Oleogels of virgin olive oil with carnauba wax and monoglyceride as spreadable products

    OpenAIRE

    Öǧütcü, M.; Yılmaz, E

    2014-01-01

    The oleogels of virgin olive oil with carnauba wax and monoglyceride were prepared to determine the most suitable spreadable product. The oil binding capacities of monoglyceride oleogels were higher than those of the carnauba wax oleogels. There was no true crystalline structure with carnauba wax at 3%. Although the highest solid fat content was in the 10% monoglyceride oleogel (9.38%), it was 12.15% in the commercial breakfast margarine at 20 °C. The peak melting temperature of the margarine...

  16. Caffeine and theobromine in epicuticular wax of Ilex paraguariensis A. St.-Hil.

    Science.gov (United States)

    Athayde, M L; Coelho, G C; Schenkel, E P

    2000-12-01

    Caffeine and theobromine were identified and quantified in leaf epicuticular waxes of Ilex paraguariensis A. St.-Hil. (Aquifoliaceae). The total epicuticular leaf wax content was ca. 0.5% on average of dry leaf weight. Epicuticular caffeine and theobromine contents varied from 0.16 to 127.6 microg/mg and from 0 to 9.5 microg/mg of wax, respectively. For some selected samples, the intracellular methylxanthine concentration was also determined. A positive correlation was found between inner and epicuticular caffeine contents.

  17. Organic esters for lubricating compositions

    Energy Technology Data Exchange (ETDEWEB)

    Imparato, L.; Mancini, G.

    1981-01-06

    An ester, adapted for use as a component of a multigrade lubricating oil, is prepared by reacting: A. A mixture of bifunctional and trifunctional polyols wherein the molar ratio of the bifunctional polyols to the trifunctional polyols is in the range of 1:2.5 to 1:10; and B. A mixture of linear monocarboxylic acids containing from 6 to 8 carbon atoms, wherein the molar average is c7, and of linea monocarboxylic acids containing from 12 to 18 carbon atoms, the molar ratio of the c6 to c8 acids and the c12 to c18 acids being in the range of from 4:1 to 19:1.

  18. Bioinspired Composite Coating with Extreme Underwater Superoleophobicity and Good Stability for Wax Prevention in the Petroleum Industry.

    Science.gov (United States)

    Liang, Weitao; Zhu, Liqun; Li, Weiping; Yang, Xin; Xu, Chang; Liu, Huicong

    2015-10-13

    Wax deposition is a detrimental problem that happens during crude oil production and transportation, which greatly reduces transport efficiency and causes huge economic losses. To avoid wax deposition, a bioinspired composite coating with excellent wax prevention and anticorrosion properties is developed in this study. The prepared coating is composed of three films, including an electrodeposited Zn film for improving corrosion resistance, a phosphating film for constructing fish-scale morphology, and a silicon dioxide film modified by a simple spin-coating method for endowing the surface with superhydrophilicity. Good wax prevention performance has been investigated in a wax deposition test. The surface morphology, composition, wetting behaviors, and stability are systematically studied, and a wax prevention mechanism is proposed, which can be calculated from water film theory. This composite coating strategy which shows excellent properties in both wax prevention and stability is expected to be widely applied in the petroleum industry.

  19. Cuticular lipid composition, surface structure, and gene expression in Arabidopsis stem epidermis.

    Science.gov (United States)

    Suh, Mi Chung; Samuels, A Lacey; Jetter, Reinhard; Kunst, Ljerka; Pollard, Mike; Ohlrogge, John; Beisson, Fred

    2005-12-01

    All vascular plants are protected from the environment by a cuticle, a lipophilic layer synthesized by epidermal cells and composed of a cutin polymer matrix and waxes. The mechanism by which epidermal cells accumulate and assemble cuticle components in rapidly expanding organs is largely unknown. We have begun to address this question by analyzing the lipid compositional variance, the surface micromorphology, and the transcriptome of epidermal cells in elongating Arabidopsis (Arabidopsis thaliana) stems. The rate of cell elongation is maximal near the apical meristem and decreases steeply toward the middle of the stem, where it is 10 times slower. During and after this elongation, the cuticular wax load and composition remain remarkably constant (32 microg/cm2), indicating that the biosynthetic flux into waxes is closely matched to surface area expansion. By contrast, the load of polyester monomers per unit surface area decreases more than 2-fold from the upper (8 microg/cm2) to the lower (3 microg/cm2) portion of the stem, although the compositional variance is minor. To aid identification of proteins involved in the biosynthesis of waxes and cutin, we have isolated epidermal peels from Arabidopsis stems and determined transcript profiles in both rapidly expanding and nonexpanding cells. This transcriptome analysis was validated by the correct classification of known epidermis-specific genes. The 15% transcripts preferentially expressed in the epidermis were enriched in genes encoding proteins predicted to be membrane associated and involved in lipid metabolism. An analysis of the lipid-related subset is presented.

  20. Performance of Surfactant Methyl Ester Sulphonate solution for Oil Well Stimulation in reservoir sandstone TJ Field

    Science.gov (United States)

    Eris, F. R.; Hambali, E.; Suryani, A.; Permadi, P.

    2017-05-01

    Asphaltene, paraffin, wax and sludge deposition, emulsion and water blocking are kinds ofprocess that results in a reduction of the fluid flow from the reservoir into formation which causes a decrease of oil wells productivity. Oil well Stimulation can be used as an alternative to solve oil well problems. Oil well stimulation technique requires applying of surfactant. Sodium Methyl Ester Sulphonate (SMES) of palm oil is an anionic surfactant derived from renewable natural resource that environmental friendly is one of potential surfactant types that can be used in oil well stimulation. This study was aimed at formulation SMES as well stimulation agent that can identify phase transitions to phase behavior in a brine-surfactant-oil system and altered the wettability of rock sandstone and limestone. Performance of SMES solution tested by thermal stability test, phase behavioral examination and rocks wettability test. The results showed that SMES solution (SMES 5% + xylene 5% in the diesel with addition of 1% NaCl at TJformation water and SMES 5% + xylene 5% in methyl ester with the addition of NaCl 1% in the TJ formation water) are surfactant that can maintain thermal stability, can mostly altered the wettability toward water-wet in sandstone reservoir, TJ Field.

  1. Radio-Modulatory Potential ofCaffeic Acid Phenethyl Ester: A Therapeutic Perspective.

    Science.gov (United States)

    Anjaly, Km; Tiku, Ashu

    2017-11-13

    Use of natural agents is an upcoming area of research in cancer biology. Caffeic acid phenethyl ester has received great attention because of its therapeutic potential in various conditions including cancer. It is an active/abundant component of propolis. Propolis is a honey bee hive product produced by bees using their enzyme-rich digestive secretions on resinous mix, bee wax and pollen from plants. It is used to protect the beehive against bacteria and other infections.Although a lot of work has been done on chemotherapeutic aspects of CAPE, its role as a radiomodulator is yet to be delineated. It can act both as radioprotector and radiosensitizer. Depending on the tissue type it can modulate the radiation response by following different mechanisms. This review will focus on the differential radiomodulatory effects of Caffeic Acid Phenethyl Ester in normal and cancer cells.Besides chemistry and bioavailability,it's potential as a therapeutic agent against radiation induced damage will also be discussed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  2. Morphological and thermal evaluation of blends of polyethylene wax and paraffin

    Energy Technology Data Exchange (ETDEWEB)

    Akishino, J.K. [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Cerqueira, D.P. [Companhia de Eletricidade do Estado da Bahia—COELBA, Salvador, BA (Brazil); Silva, G.C. [Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Swinka-Filho, V. [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil); Munaro, M., E-mail: marilda@lactec.org.br [Graduate Program in Engineering and Materials Science, Federal University of Parana, Curitiba, PR (Brazil); Institute for the Development of Technology, LACTEC, PO Box 19067, 81531-990 Curitiba, PR (Brazil)

    2016-02-20

    Highlights: • Thermal properties of polyethylene wax and paraffin were investigated. • The blends were characterized by DSC, XRD and DMTA. • The melting temperatures were between those of the pure constituents. • The crystallinity decreased with addition of polyethylene wax. • The softening temperatures did not vary linearly with the composition. - Abstract: The thermal behavior and the morphology of blends of polyethylene wax and paraffin were investigated to evaluate the feasibility of using these materials to obtain a new temperature-indicating device to use in order to indicate failures in electrical connections due to overheating. The samples were evaluated with differential scanning calorimetry (DSC), X-ray diffraction (XRD) and dynamic mechanical thermal analysis (DMTA). The results showed that the crystallinity decreases as the concentration of polyethylene wax increases. In the compositions tested, the components were not miscible in the crystalline phase, and these compositions exhibited solid/liquid transitions at temperatures between those of the individual components.

  3. New Insights into the Composition of Wax-Like Materials in Chondrites

    Science.gov (United States)

    Krebsz, M.; Garenne, A.; Quirico, E.; Bonal, L.; Beck, P.; Vuitton, V.; Thissen, R.; Flandinet, L.; Schmitt, B.; Kereszturi, A.

    2013-09-01

    Our study aims to extract wax-like compounds from a series of carbonaceous chondrites in order to perform a combined characterization by IR, Raman and NMR spectroscopies, and secondary ion mass spectrometry.

  4. Effect of matrix granulation and wax coating on the dissolution rates ...

    African Journals Online (AJOL)

    disintegrating) granules consisting of paracetamol (drug) and acrylatemethacrylate copolymer, a matrix forming material. The effect of coating the matrix granules with wax on the drug release profiles was also investigated. The objective was to ...

  5. In search of low cost biological analysis: Wax or acrylic glue bonded paper microfluidic devices

    KAUST Repository

    Kodzius, Rimantas

    2011-11-04

    In this body of work we have been developing and characterizing paper based microfluidic fabrication technologies to produce low cost biological analysis. Specifically we investigated the performance of paper microfluidics that had been bonded using wax o

  6. Phenolic compounds and the colour of oranges subjected to a combination treatment of waxing and irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Moussaid, M.; Lacroix, M.; Nketsia-Tabiri, J.; Boubekri, C

    2000-03-01

    The effects of waxing, irradiation dose and storage on phenolics and colour of irradiated oranges were investigated. Mature oranges (Maroc late) waxed or unwaxed were treated with 0, 1 or 2 kGy radiation and stored up to 9 weeks at 20 deg. C and 40-50% r.h. Colour of the oranges, total phenols and flavones in the peel were measured. Phenolic compounds increased with irradiation dose and storage time. Hue angle, value and chroma of the orange colour were more affected by waxing and storage time than the irradiation treatment. Changes in the phenolic compounds were linked with changes in the redness and saturation of the orange colour. Irradiation stimulated synthesis of flavones; waxing controlled changes induced by irradiation. (author)

  7. Leaf and stem anatomy in eight Hypericum species (Clusiaceae)

    OpenAIRE

    Perone, Rosaria; De Rosa, Paolo; De Castro, Olga; Colombo, Paolo

    2013-01-01

    Foliar micromorphology, epicuticular wax morphology and anatomical featuresof leaves and stem, particularly secondary xylem, were examined with light microscopy,general and histochemical staining and scanning electron microscopy in eightHypericum species. Outer tegument tissue and type of secondary xylem are determiningcharacteristics. Secondary xylem is ring-porous in H. perforatum, H. perfoliatum, H. tetrapterum, H. triquetrifolium, H. androsaemum and H. hircinum. In H. aegypticum and H. pu...

  8. A review of the performance and structural considerations of paraffin wax hybrid rocket fuels with additives

    Science.gov (United States)

    Veale, Kirsty; Adali, Sarp; Pitot, Jean; Brooks, Michael

    2017-12-01

    Paraffin wax as a hybrid rocket fuel has not been comprehensively characterised, especially regarding the structural feasibility of the material in launch applications. Preliminary structural testing has shown paraffin wax to be a brittle, low strength material, and at risk of failure under launch loading conditions. Structural enhancing additives have been identified, but their effect on motor performance has not always been considered, nor has any standard method of testing been identified between research institutes. A review of existing regression rate measurement techniques on paraffin wax based fuels and the results obtained with various additives are collated and discussed in this paper. The review includes 2D slab motors that enable visualisation of liquefying fuel droplet entrainment and the effect of an increased viscosity on the droplet entrainment mechanism, which can occur with the addition of structural enhancing polymers. An increased viscosity has been shown to reduce the regression rate of liquefying fuels. Viscosity increasing additives that have been tested include EVA and LDPE. Both these additives increase the structural properties of paraffin wax, where the elongation and UTS are improved. Other additives, such as metal hydrides, aluminium and boron generally offer improvements on the regression rate. However, very little consideration has been given to the structural effects these additives have on the wax grain. A 40% aluminised grain, for example, offers a slight increase in the UTS but reduces the elongation of paraffin wax. Geometrically accurate lab-scale motors have also been used to determine the regression rate properties of various additives in paraffin wax. A concise review of all available regression rate testing techniques and results on paraffin wax based hybrid propellants, as well as existing structural testing data, is presented in this paper.

  9. Isolation and recrystallization of epicuticular waxes from Sorbus and Cotoneaster leaves

    OpenAIRE

    Ganeva Tsveta; Stefanova Miroslava; Koleva Dimitrina; Ruiz Segundo Ríos

    2015-01-01

    Wax morphology and chemical composition are widely accepted to be important for the protective properties of the leaf’s surface and also valuable characteristics in plant systematics. The leaves of Sorbus domestica L. and Cotoneaster granatensis Boiss., species of two large genera with intricate taxonomy referred to subtribe Pyrinae, Rosaceae (formerly subfamily Maloideae), were studied by scanning electron microscope (SEM) and performing different methods of wax isola...

  10. Synthesis of Trimethylolpropane Esters of Calophyllum Methyl Esters : Effect of Temperature and Molar Ratio

    Directory of Open Access Journals (Sweden)

    Yeti Widyawati

    2014-12-01

    Full Text Available Trimethylolpropane esters were synthesized by transesterification of calophyllum methyl esters and trimethylolpropane using a calcium oxide as the catalyst. The results showed that the optimal reaction conditions (temperature: 130 0C, reaction time: 5 h, reactant molar ratio: 3.9:1, catalyst amount 3%w/w, and formed  trimethylolpropane ester of 79.0% were obtained. The basic physicochemical properties of the trimethylolpropane esters were the following : kinematic viscosities of 56.40 cSt and 8.8 cSt at 40 0C and 100 0C,  viscosity index 193, flash point 218 0C and pour point -3 0C. So Methyl esters of fatty acids of would callophylum  methyl ester is good raw material for the synthesis of lubricating oils.

  11. Waxes and plastic film in relation to the shelf life of yellow passion fruit

    Directory of Open Access Journals (Sweden)

    Mota Wagner Ferreira da

    2003-01-01

    Full Text Available The high perishability of the yellow passion fruit (Passiflora edulis f. flavicarpa reduces its postharvest conservation and availability, mainly for in natura consumption. These losses of quality and commercial value occur due to the high respiration and loss of water. This work aimed to evaluate the influence of a modified atmosphere - wax emulsions and plastic film - on the shelf life of the yellow passion fruit. Plastic film (Cryovac D-955, 15 mum thickness reduced fresh weight loss and fruit wilting, kept higher fruit and rind weight and higher pulp osmotic potential over the storage period. However, it was not efficient in the control of rottenness. Sparcitrus wax (22-23% polyethylene/maleyc resin caused injury to the fruit, high fruit weight losses and wilting and resulted in lower pulp osmotic potential; this wax lead to a higher concentration of acid and a lower relation of soluble solids/acidity. Among the tested waxes, Fruit Wax (18-21% carnauba wax was the best, promoting reduced weight loss, wilting and rottenness.

  12. Wax deposition measurement under turbulent flow conditions for a live waxy crude from Turkmenistan

    Energy Technology Data Exchange (ETDEWEB)

    Akbarzadeh, K.; Ratulowski, J.; Davies, T. [Schlumberger, Edmonton, AB (Canada). DBR Technology Center; Norpiah, R.M. [Petronas (Malaysia)

    2008-07-01

    The challenges facing deepwater oil production were discussed, with particular reference to flow assurance problems caused by cold temperatures and long offsets that impact the flow of fluids from the wellbore to the export line. The precipitation and deposition of waxy material is one of the most pervasive flow assurance issues. In order to develop operating strategies that address flow assurance risks while minimizing capital and operating costs, it is important to obtain fluid property data and phase behaviour data. Conventional deposition testing for wax is typically run on dead oil in a low shear environment. However, the flow regime in a production system is turbulent with high wall shears because the oil, gas and water are at elevated pressures. As such, wax deposition data for dead oil taken under laminar flow conditions overpredicts the actual wax deposition rates observed at field conditions. Therefore, a high-pressure deposition cell was used in this study to investigate the deposition tendency of a waxy crude oil from Turkmenistan at field conditions. The study also examined the influence of flow rate, temperature and wax inhibitors on wax deposition. The effect of solution gas was also determined. A method for scaling the deposition cell data to pipe flow was also presented and used in a multiphase flow simulator to predict the wax deposition profile in the field.

  13. Prediction of wax buildup in 24 inch cold, deep sea oil loading line

    Energy Technology Data Exchange (ETDEWEB)

    Asperger, R.G.; Sattler, R.E.; Tolonen, W.J.; Pitchford, A.C.

    1981-10-01

    When designing pipelines for cold environments, it is important to know how to predict potential problems due to wax deposition on the pipeline's inner surface. The goal of this work was to determine the rate of wax buildup and the maximum, equlibrium wax thickness for a North Sea field loading line. The experimental techniques and results used to evaluate the waxing potential of the crude oil (B) are described. Also, the theoretic model which was used for predicting the maximum wax deposit thickness in the crude oil (B) loading pipeline at controlled temperatures of 40 F (4.4 C) and 100 F (38 C), is illustrated. Included is a recommendation of a procedure for using hot oil at the end of a tanker loading period in order to dewax the crude oil (B) line. This technique would give maximum heating of the pipeline and should be followed by shutting the hot oil into the pipeline at the end of the loading cycle which will provide a hot oil soaking to help soften existing wax. 14 references.

  14. Bitumen Emulsion Destabilization Kinetics: Importance of the Crystallized Wax Content.

    Science.gov (United States)

    Boucard, Laure; Gaudefroy, Vincent; Chailleux, Emmanuel; Farcas, Fabienne; Schmitt, Véronique

    2017-09-26

    We study the kinetics of bitumen emulsion destabilization after the addition of sodium hydroxide (NaOH) using macroscopic observations and rheology. Destabilization occurs in a two-step process: first, emulsion flocculates, forming a percolated network of contacting drops, and then coalescence provokes the irreversible connection of bitumen drops, leading to a bitumen continuous network that further relaxes the shape. We show that the destabilization kinetics exhibits a rheological easily identifiable signature allowing reproducible and accurate measurement of the connection/coalescence time trc (which corresponds to the time, determined by rheology, required to form the network made of drops connected by nonrelaxed coalescence). Using this powerful tool, we show that, even if viscosity is thought to govern the shape relaxation of the connected network it does not determine the connection kinetics. Indeed, emulsions with similar rheological behaviors exhibit very different destabilization times. Instead, we evidence a good correlation between the bitumen crystallized wax content and trc. From these experimental results, we discuss the stabilizing effect against coalescence of crystals in bitumen emulsions.

  15. Cobalt-catalyzed hydrogenation of esters to alcohols: unexpected reactivity trend indicates ester enolate intermediacy.

    Science.gov (United States)

    Srimani, Dipankar; Mukherjee, Arup; Goldberg, Alexander F G; Leitus, Gregory; Diskin-Posner, Yael; Shimon, Linda J W; Ben David, Yehoshoa; Milstein, David

    2015-10-12

    The atom-efficient and environmentally benign catalytic hydrogenation of carboxylic acid esters to alcohols has been accomplished in recent years mainly with precious-metal-based catalysts, with few exceptions. Presented here is the first cobalt-catalyzed hydrogenation of esters to the corresponding alcohols. Unexpectedly, the evidence indicates the unprecedented involvement of ester enolate intermediates. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Space-Qualifiable Cyanate Ester Elastomer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In Phase 1, CRG demonstrated the feasibility of a novel approach to prepare cyanate ester based elastomers. This approach polymerizes in-situ siloxane within a...

  17. Space-Qualifiable Cyanate Ester Elastomer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Cornerstone Research Group, Inc. (CRG) proposes to design and develop a space-qualifiable cyanate ester elastomer for application in self-deployable space structures...

  18. Pharmacokinetics of Ketorolac Pentyl Ester, a Novel Ester Derivative of Ketorolac, in Rabbits

    Directory of Open Access Journals (Sweden)

    Jann-Inn Tzeng

    2005-08-01

    Full Text Available Ketorolac is a potent nonsteroidal anti-inflammatory drug. Recently, a novel ester of ketorolac, ketorolac pentyl ester, was synthesized. When prepared in injectable oil, the new agent demonstrated a long duration of action. Ketorolac pentyl ester was synthesized using a prodrug design by esterification of ketorolac, and appeared to be a prodrug of ketorolac in vivo, which needed to be confirmed. The aim of the present study was to establish the prodrug's pharmacokinetics in vivo, and to confirm whether or not ketorolac pentyl ester was a prodrug of ketorolac. Pharmacokinetic profiles of intravenous ketorolac and its pentyl ester on an equal-molar basis in six rabbits were evaluated. A high-performance liquid chromatographic method was used to determine the plasma concentrations of ketorolac and its pentyl ester. We found that the plasma concentrations of ketorolac pentyl ester declined rapidly after injection and so did the conversion of ketorolac pentyl ester to ketorolac. Also, the conversion of ketorolac was proved complete when compared with intravenous ketorolac under an equi-molar basis. In conclusion, this in vivo pharmacokinetic study confirmed that keterolac pentyl ester was a prodrug of keterolac.

  19. Wax on, wax off

    DEFF Research Database (Denmark)

    Bos, Nicky Peter Maria; Grinsted, Lena; Holman, Luke

    2011-01-01

    of a waxy layer of colony-specific hydrocarbons on the body surface. Genetic and environmental differences between colony members may confound recognition and social cohesion, so many species perform behaviors that homogenize the odor label, such as mouth-to-mouth feeding and allogrooming. Here, we test......Social animals use recognition cues to discriminate between group members and non-members. These recognition cues may be conceptualized as a label, which is compared to a neural representation of acceptable cue combinations termed the template. In ants and other social insects, the label consists...... for another mechanism of cue exchange: indirect transfer of cuticular hydrocarbons via the nest material. Using a combination of chemical analysis and behavioral experiments with Camponotus aethiops ants, we show that nest soil indirectly transfers hydrocarbons between ants and affects recognition behavior...

  20. Cytotoxic lignan esters from Cinnamomum osmophloeum.

    Science.gov (United States)

    Chen, Tai-Hung; Huang, Yu-Hao; Lin, Jhih-Jhang; Liau, Bing-Chung; Wang, Sheng-Yang; Wu, Yang-Chang; Jong, Ting-Ting

    2010-04-01

    The bark and roots of Cinnamomum osmophloeum are widely used in Taiwan as spice substitutes for C. CASSIA. We have isolated three novel lignan esters, one dibenzylbutane-type ligan ester [9,9'-di-O-feruloyl-(+)-5,5'-dimethoxy secoisolariciresinol (3)] and two cyclolignan esters [(7' S,8' R,8 R) -lyoniresinol-9-O-(E)-feruloyl ester ( 5) and (7' S,8' R,8 R)-lyoniresinol-9,9'-di-O-(E)-feruloyl ester (6)], and several known lignans from the heartwood and roots of C. osmophloeum. We identified these compounds using 1D and 2D NMR spectroscopy and mass spectrometry. Cytotoxicity assays of these novel lignan esters revealed that compound 6 has strong activities against human liver cancer (HepG2 and Hep3B) and oral cancer (Ca9-22) cells, with IC(50) values of 7.87, 4.31, and 2.51 microg/mL, respectively. Georg Thieme Verlag KG Stuttgart.New York.

  1. Allenyl esters as quenching agents for ruthenium olefin metathesis catalysts.

    Science.gov (United States)

    Roy, Animesh; Silvestri, Maximilian A; Hall, Robert A; Lepore, Salvatore D

    2017-01-04

    In the attempt to synthesize substituted allenyl esters through a metathesis coupling of unsubstituted allenyl esters and alkenes using a variety of ruthenium catalysts, it was discovered that allenyl esters themselves cleanly arrested the activity of the catalysts. Further studies suggests possible utility of allene esters as general quenching agents for metathesis reactions. To explore this idea, several representative olefin metathesis reactions, including ring closing, were successfully terminated by the addition of simple allenyl esters for more convenient purification.

  2. Numerical performance study of paraffin wax dispersed with alumina in a concentric pipe latent heat storage system

    Directory of Open Access Journals (Sweden)

    Valan Arasu Amirtham

    2013-01-01

    Full Text Available Latent heat energy storage systems using paraffin wax could have lower heat transfer rates during melting/freezing processes due to its inherent low thermal conductivity. The thermal conductivity of paraffin wax can be enhanced by employing high conductivity materials such as alumina (Al2O3. A numerical analysis has been carried out to study the performance enhancement of paraffin wax with nanoalumina (Al2O3 particles in comparison with simple paraffin wax in a concentric double pipe heat exchanger. Numerical analysis indicates that the charge-discharge rates of thermal energy can be greatly enhanced using paraffin wax with alumina as compared with a simple paraffin wax as PCM.

  3. STRENGTH OF A WAX COATED SILK YARN UNDER PERSPIRATION SOLUTIONS

    Directory of Open Access Journals (Sweden)

    BONET Maria Angeles

    2014-05-01

    Full Text Available Medical products play an important role in our society. Textile structures offer a wide variety of products which can be used in a wide variety of medical applications. When treating a deep wound, it needs to be sewed with some yarns in order to stick both sides in the wound. It requires the yarn to be in contact with the skin and depending on the place the wound is located, it is soaked on corporal fluids such as perspiration, saliva, blood, etc. The aim of this work is to determine if silk threads can be damaged by perspiration and lose some properties. Yarns with different conditions have been treated for 10 days with perspiration solutions and results showed that traction resistance decreases for some of the studied yarns and that microorganism s grow on the yarn surface. Despite the fact that some yarns show antimicrobial treatments, this test showed that wax coated is not enough to prevent the presence of microorganisms on the yarn. This is an important fact as the yarn is in directly in contact with the wounded are a and it can implies infections for the patiente. Results evidence that perspiration solutions can reduce the yarn ́s resistance and it can be a problem if the yarn lasts longer than 10 days. Obviously, the test was conducted at room temperature, about 22º C, and patiente's body is at higher levels 36.5-37º C. Thus, further studies should be conducted in order to test temperature or even though fineness influence.

  4. Dental students' preferences and performance in crown design: conventional wax-added versus CAD.

    Science.gov (United States)

    Douglas, R Duane; Hopp, Christa D; Augustin, Marcus A

    2014-12-01

    The purpose of this study was to evaluate dental students' perceptions of traditional waxing vs. computer-aided crown design and to determine the effectiveness of either technique through comparative grading of the final products. On one of twoidentical tooth preparations, second-year students at one dental school fabricated a wax pattern for a full contour crown; on the second tooth preparation, the same students designed and fabricated an all-ceramic crown using computer-aided design (CAD) and computer-aided manufacturing (CAM) technology. Projects were graded for occlusion and anatomic form by three faculty members. On completion of the projects, 100 percent of the students (n=50) completed an eight-question, five-point Likert scalesurvey, designed to assess their perceptions of and learning associated with the two design techniques. The average grades for the crown design projects were 78.3 (CAD) and 79.1 (wax design). The mean numbers of occlusal contacts were 3.8 (CAD) and 2.9(wax design), which was significantly higher for CAD (p=0.02). The survey results indicated that students enjoyed designing afull contour crown using CAD as compared to using conventional wax techniques and spent less time designing the crown using CAD. From a learning perspective, students felt that they learned more about position and the size/strength of occlusal contacts using CAD. However, students recognized that CAD technology has limits in terms of representing anatomic contours and excursive occlusion compared to conventional wax techniques. The results suggest that crown design using CAD could be considered as an adjunct to conventional wax-added techniques in preclinical fixed prosthodontic curricula.

  5. Overexpression of Arabidopsis MYB96 confers drought resistance in Camelina sativa via cuticular wax accumulation.

    Science.gov (United States)

    Lee, Saet Buyl; Kim, Hyojin; Kim, Ryeo Jin; Suh, Mi Chung

    2014-09-01

    Camelina has been highlighted as an emerging oilseed crop. Transgenic Camelina plants overexpressing Arabidopsis MYB96 exhibited drought resistance by activating expression of Camelina wax biosynthetic genes and accumulating wax load. Camelina (Camelina sativa L.) is an oilseed crop in the Brassicaeae family with potential to expand biofuel production to marginal land. The aerial portion of all land plants is covered with cuticular wax to protect them from desiccation. In this study, the Arabidopsis MYB96 gene was overexpressed in Camelina under the control of the CaMV35S promoter. Transgenic Camelina plants overexpressing Arabidopsis MYB96 exhibited normal growth and development and enhanced tolerance to drought. Deposition of epicuticular wax crystals and total wax loads increased significantly on the surfaces of transgenic leaves compared with that of non-transgenic plants. The levels of alkanes and primary alcohols prominently increased in transgenic Camelina plants relative to non-transgenic plants. Cuticular transpiration occurred more slowly in transgenic leaves than that in non-transgenic plants. Genome-wide identification of Camelina wax biosynthetic genes enabled us to determine that the expression levels of CsKCS2, CsKCS6, CsKCR1-1, CsKCR1-2, CsECR, and CsMAH1 were approximately two to sevenfold higher in transgenic Camelina leaves than those in non-transgenic leaves. These results indicate that MYB96-mediated transcriptional regulation of wax biosynthetic genes is an approach applicable to generating drought-resistant transgenic crops. Transgenic Camelina plants with enhanced drought tolerance could be cultivated on marginal land to produce renewable biofuels and biomaterials.

  6. Anatomically realistic ultrasound phantoms using gel wax with 3D printed moulds

    Science.gov (United States)

    Maneas, Efthymios; Xia, Wenfeng; Nikitichev, Daniil I.; Daher, Batol; Manimaran, Maniragav; Wong, Rui Yen J.; Chang, Chia-Wei; Rahmani, Benyamin; Capelli, Claudio; Schievano, Silvia; Burriesci, Gaetano; Ourselin, Sebastien; David, Anna L.; Finlay, Malcolm C.; West, Simeon J.; Vercauteren, Tom; Desjardins, Adrien E.

    2018-01-01

    Here we describe methods for creating tissue-mimicking ultrasound phantoms based on patient anatomy using a soft material called gel wax. To recreate acoustically realistic tissue properties, two additives to gel wax were considered: paraffin wax to increase acoustic attenuation, and solid glass spheres to increase backscattering. The frequency dependence of ultrasound attenuation was well described with a power law over the measured range of 3–10 MHz. With the addition of paraffin wax in concentrations of 0 to 8 w/w%, attenuation varied from 0.72 to 2.91 dB cm‑1 at 3 MHz and from 6.84 to 26.63 dB cm‑1 at 10 MHz. With solid glass sphere concentrations in the range of 0.025–0.9 w/w%, acoustic backscattering consistent with a wide range of ultrasonic appearances was achieved. Native gel wax maintained its integrity during compressive deformations up to 60%; its Young’s modulus was 17.4  ±  1.4 kPa. The gel wax with additives was shaped by melting and pouring it into 3D printed moulds. Three different phantoms were constructed: a nerve and vessel phantom for peripheral nerve blocks, a heart atrium phantom, and a placental phantom for minimally-invasive fetal interventions. In the first, nerves and vessels were represented as hyperechoic and hypoechoic tubular structures, respectively, in a homogeneous background. The second phantom comprised atria derived from an MRI scan of a patient with an intervening septum and adjoining vena cavae. The third comprised the chorionic surface of a placenta with superficial fetal vessels derived from an image of a post-partum human placenta. Gel wax is a material with widely tuneable ultrasound properties and mechanical characteristics that are well suited for creating patient-specific ultrasound phantoms in several clinical disciplines.

  7. Cabbage waxes affect Trissolcus brochymenae response to short-range synomones.

    Science.gov (United States)

    Frati, Francesca; Salerno, Gianandrea; Conti, Eric

    2013-12-01

    We show that induced synomones, emitted as a consequence of Murgantia histrionica activity on Brassica oleracea, are adsorbed by the epicuticular waxes of leaves and perceived by the egg parasitoid Trissolcus brochymenae. Leaves were exposed to M. histrionica females placed on the abaxial leaf surface. After 24 h, the leaves were treated mechanically using gum arabic, or chemically using chloroform, on the adaxial surface, and finally the adaxial surface was assayed with T. brochymenae by two-choice tests in a closed arena. Wasp females responded to mechanically dewaxed cabbage leaf portions with feeding punctures and footprints (Ff) and with feeding punctures, oviposition and footprints (FOf), showing no effect of wax removal. In contrast, the removal of the epicuticular waxes from leaf portions close to FOf, and from leaves with oviposition and footprints (Of), determined the lack of responses by T. brochymenae. Solvent extracts of different treatments were bioassayed, but only FOf triggered parasitoid response. Thus the detection of oviposition-induced synomones by the parasitoid depends on their adsorption by the epicuticular waxes. Mechanical wax removal from leaf portions contaminated with host footprints (f) also determined a lack of wasp responses, suggesting that the footprints might trigger the induction of a "footprint-induced synomone" adsorbed onto the epicuticular waxes and exploited by the parasitoid. Leaf portions with the abaxial lamina previously dewaxed and then contaminated by footprints (D+f) of M. histrionica did not affect the parasitoid response, indicating that the abaxial epicuticular waxes are not directly involved in the chemicals induced by M. histrionica footprints. © 2012 Institute of Zoology, Chinese Academy of Sciences.

  8. Production and characterization of vaginal suppositories with propolis wax as active agent to prevent and treat Fluor albus

    Science.gov (United States)

    Farida, Siti; Azizah, Nurul; Hermansyah, Heri; Sahlan, Muhamad

    2017-02-01

    Based on the content contained in propolis wax especially antimicrobial function, it can be analyzed that propolis wax had superiority for Fluor albus. This research was conducted on two formulation of vaginal suppositories with base, supplementary and active agent as a fixed variable: 2% propolis wax (% w/w). Evaluation of this research were weight variation, melting time, consistency, irritation effect test and physical and chemical stability test (organoleptic, pH and polyphenol content).

  9. Disulfide-containing poly (beta-amino ester)s for gene delivery

    NARCIS (Netherlands)

    Lin, C.; Hennink, W.E.; Lammens, T.M.; Feijen, J.; Zhong, Zhiyuan; Sam, T; Gu, H.; Lok, M.C.; Jiang, X.; Feijen, Jan; Engbersen, Johannes F.J.

    2006-01-01

    A group of new disulfide-containing poly(β-amino ester)s was synthesized and evaluated as non-viral gene delivery vectors. These linear polymers were obtained by Michael addition of a number of selected amines to bis(2-acryloyloxyethyl) disulfide. It was shown that the disulfide-containing

  10. Types of Stem Cells

    Science.gov (United States)

    ... Stem Cell Glossary Search Toggle Nav Types of Stem Cells Stem cells are the foundation from which all ... Learn About Stem Cells > Types of Stem Cells Stem cells Stem cells are the foundation for every organ ...

  11. Curbing the Growth of Wax Bean (Vigna unguiculata L. via a Novel Complex of Nano Zinc Oxide/Vermicompost

    Directory of Open Access Journals (Sweden)

    Farideh BEHBOUDI

    2016-12-01

    Full Text Available Vermicompost (VC samples were prepared from manure and spent mushroom compost (SMC and were impregnated with zinc oxide nanoparticles (ZnO NPs, giving ZnO NPs/VC complexes that were added into the soil in which wax beans (Vigna unguiculata L. were then planted. The study was carried out through a factorial experiment in a randomized complete block design with three factors. The experimental factors included: ZnO NPs (0, 0.4, 0.8 and 1.2 mg kg-1, two substrate types (cow manure and SMC and VC (2.5, 5 and 7.5 weight percentages. To the substrate types, adult earthworms (Eisenia fetida were added. Specifically, after three months, the prepared VC was soaked in ZnO NPs solutions, mixed with soil (according to cultivation substrate weight, then employed in wet plantation of wax beans. The obtained results showed that with increasing ZnO NPs, leaves’ chlorophyll, grains number per pod, stem length, hundred grains weight, grain yield, and the grain protein content significantly decreased. In general, the usage of these NPs in the applied amounts could curb the undesired growth of this species.

  12. Production and biological function of volatile esters in Saccharomyces cerevisiae.

    Science.gov (United States)

    Saerens, Sofie M G; Delvaux, Freddy R; Verstrepen, Kevin J; Thevelein, Johan M

    2010-03-01

    The need to understand and control ester synthesis is driven by the fact that esters play a key role in the sensorial quality of fermented alcoholic beverages like beer, wine and sake. As esters are synthesized in yeast via several complex metabolic pathways, there is a need to gain a clear understanding of ester metabolism and its regulation. The individual genes involved, their functions and regulatory mechanisms have to be identified. In alcoholic beverages, there are two important groups of esters: the acetate esters and the medium-chain fatty acid (MCFA) ethyl esters. For acetate ester synthesis, the genes involved have already been cloned and characterized. Also the biochemical pathways and the regulation of acetate ester synthesis are well defined. With respect to the molecular basis of MCFA ethyl ester synthesis, however, significant progress has only recently been made. Next to the characterization of the biochemical pathways and regulation of ester synthesis, a new and more important question arises: what is the advantage for yeast to produce these esters? Several hypotheses have been proposed in the past, but none was satisfactorily. This paper reviews the current hypotheses of ester synthesis in yeast in relation to the complex regulation of the alcohol acetyl transferases and the different factors that allow ester formation to be controlled during fermentation.

  13. Role of needle surface waxes in dynamic exchange of mono- and sesquiterpenes

    Directory of Open Access Journals (Sweden)

    J. Joensuu

    2016-06-01

    Full Text Available Biogenic volatile organic compounds (BVOCs produced by plants have a major role in atmospheric chemistry. The different physicochemical properties of BVOCs affect their transport within and out of the plant as well as their reactions along the way. Some of these compounds may accumulate in or on the waxy surface layer of conifer needles and participate in chemical reactions on or near the foliage surface. The aim of this work was to determine whether terpenes, a key category of BVOCs produced by trees, can be found on the epicuticles of Scots pine (Pinus sylvestris L. and, if so, how they compare with the terpenes found in shoot emissions of the same tree. We measured shoot-level emissions of pine seedlings at a remote outdoor location in central Finland and subsequently analysed the needle surface waxes for the same compounds. Both emissions and wax extracts were clearly dominated by monoterpenes, but the proportion of sesquiterpenes was higher in the wax extracts. There were also differences in the terpene spectra of the emissions and the wax extracts. The results, therefore, support the existence of BVOC associated to the epicuticular waxes. We briefly discuss the different pathways for terpenes to reach the needle surfaces and the implications for air chemistry.

  14. EFFECT OF OIL TEMPERATURE ON THE WAX DEPOSITION OF CRUDE OIL WITH COMPOSITION ANALYSIS

    Directory of Open Access Journals (Sweden)

    Qing Quan

    Full Text Available Abstract Wax deposition behavior was investigated in a set of one-inch experiment flow loops, using a local crude oil with high wax content. The temperature of the oil phase is chosen as a variable parameter while the temperature of the coolant media is maintained constant. Detailed composition of the deposit is characterized using High Temperature Gas Chromatography. It was found that the magnitude of the diffusion of the heavier waxy components (C35-C50 decreases when the oil temperature decreases, but the magnitude of the diffusion of the lighter waxy components increases. This result means that the diffusion of wax molecules shifts towards lower carbon number, which further proves the concept of molecular diffusion. Meanwhile, a meaningful phenomenon is that the mass of the deposit increases with the oil temperature decrease, which definitely proves the influence of wax solubility on deposition, while the formation of an incipient gel layer reflects the fact that an increase in the mass of the deposit does not mean a larger wax percentage fraction at lower oil temperature.

  15. [Comparative adaptation of crowns of selective laser melting and wax-lost-casting method].

    Science.gov (United States)

    Li, Guo-qiang; Shen, Qing-yi; Gao, Jian-hua; Wu, Xue-ying; Chen, Li; Dai, Wen-an

    2012-07-01

    To investigate the marginal adaptation of crowns fabricated by selective laser melting (SLM) and wax-lost-casting method, so as to provide an experimental basis for clinic. Co-Cr alloy full crown were fabricated by SLM and wax-lost-casting for 24 samples in each group. All crowns were cemented with zinc phosphate cement and cut along longitudinal axis by line cutting machine. The gap between crown tissue surface and die was measured by 6-point measuring method with scanning electron microscope (SEM). The marginal adaptation of crowns fabricated by SLM and wax-lost-casting were compared statistically. The gap between SLM crowns were (36.51 ± 2.94), (49.36 ± 3.31), (56.48 ± 3.35), (42.20 ± 3.60) µm, and wax-lost-casting crowns were (68.86 ± 5.41), (58.86 ± 6.10), (70.62 ± 5.79), (69.90 ± 6.00) µm. There were significant difference between two groups (P casting method and SLM method provide acceptable marginal adaptation in clinic, and the marginal adaptation of SLM is better than that of wax-lost-casting method.

  16. Interaction of organic solvents with the epicuticular wax layer of wheat leaves.

    Science.gov (United States)

    Myung, Kyung; Parobek, Alexander P; Godbey, Jeffrie A; Bowling, Andrew J; Pence, Heather E

    2013-09-18

    After foliar application, compounds that are not absorbed into leaves can be removed from the leaf surface by dipping or rinsing in dilutions of organic solvents in water. However, interactions between solvent mixtures and the epicuticular wax layer have received little attention, and information on potential physical and chemical intactness of the plant surface following application of solvents is limited. In this study, wheat leaves were dipped in organic solvents at different dilutions with water, and the major component of the leaf epicuticular wax layer, 1-octacosanol, was analyzed to assess damage to the wax layer. Dipping leaves in dilutions of organic solvent higher than 60% by volume resulted in only negligible or low levels of 1-octacosanol extraction, while no 1-octacosanol was detected in any mixtures containing less than 40% organic solvent. Furthermore, analysis of leaf surfaces by scanning electron microscopy showed structural intactness of the epicuticular wax layer when organic solvent mixtures were used. Therefore, our results demonstrate that the epicuticular wax layer of wheat leaves is not altered physically or chemically by organic solvent solutions up to 40% by volume. These findings validate the use of solvent washing procedures to assess unabsorbed compounds on wheat leaf surfaces.

  17. Chemical composition of the wax secreted by a scale insect (Ceroplastes pseudoceriferus Green).

    Science.gov (United States)

    Tamaki, Y

    1966-09-01

    The wax material in the secretion of a scale insect,Ceroplastes pseudoceriferus Green was analyzed chemically with special interest to the composition of higher fatty acids and higher alcohols. The wax consists of 34.2% fatty acids, 27.1% unsaponifiable matter and 29.5% resin acids. The fatty acids were found to be a complex mixture of 15 normal acids ranging from C(8) to C(32). Of these, octacosanoic, triacontanoic and dotriacontanoic acids comprise over 30% of the wax. Presence of relatively large amount of unsaturated fatty acids of the C(18) series (2.8% of the wax) is of particular interest.From the unsaponifiable fraction, only one saturated straight chain aleohol, bexacosanol, was detected (2.7% of the original wax). The other unsaponifiable matter was considered to be cyclic or branched carbon chain, and consisted of at least 12 to 20 compounds. The resin acid fraction was also found to be a complex mixture of at least 13 to 14 components.

  18. Mechanical and Hydraulic Properties of Wax-coated Sands for Sport Surfaces

    Science.gov (United States)

    Bardet, J. P.; Benazza, C.; Bruchon, J. F.; Mishra, M.

    2009-06-01

    Natural soils such as sandy loams are being replaced by synthetic soils for various types of sport and recreational surfaces, including horseracing tracks. These synthetic soils are made of a mixture of sand, microcrystalline wax, synthetic fibers and rubber chips which optimize the mechanical and hydraulic properties of natural soils so that they drain faster after rainstorms and decrease risks of sport injuries while retaining appropriate sport performances. Silica sand, which makes up the largest fraction of synthetic soils, is hydrophyllic by nature, i.e., tends to retain water on sand grain surfaces. After rainstorms, hydrophilic surfaces retain a large amount of water, are difficult to compact, and yield uncontrollable mechanical and hydraulic properties when too moist. The addition of wax contributes to improving both mechanical and hydraulic properties of sands. Wax coats the sand grains with a thin layer, and enhances adherence between sand particles. It repels water from sand grains and influences both compaction and hydraulic properties. This study reports experimental results that help to understand the properties of wax-coated sands used in synthetic surfaces, especially the degradation of synthetic surfaces that have insufficient wax-coatings.

  19. Effects of brown coal treatment with hydrogen peroxide on brown coal wax yield

    Energy Technology Data Exchange (ETDEWEB)

    Bazarova, O.V.; Shevchenko, A.G.; Ruban, I.V.; Ksenofontov, V.G.; Turovskii, N.A. (Institut Fiziko-Organicheskoi Khimii i Uglekhimii AN UkrSSR (USSR))

    1990-09-01

    Studies preliminary treatment of brown coal with 30% hydrogen peroxide. Experiments employed 0.1-0.2 mm fractions of brown coal and were carried out at ambient temperature for 30 min with a coal:oxidizer ratio of 1:6. Sample demineralization met the requirements of ISO 602. Spectral resonance methods were employed to find that the oxidation processes of brown coal and of anthracite are similar; two spectra are presented. Coal extraction employed petroleum ether. Pre-treatment increased the wax yield from 4.3% to 10.5% in terms of coal organic mass. Wax elemental compositions are presented. Six IR spectra are shown and discussed: of initial coal wax, of pre-treated coal wax, of initial coal, of pre-treated coal, of initial coal residue (after its extraction) and of pre-treated coal residue. The 1,020 cm{sup -1} band was observed to suggest the formation of phenol structures during oxidation. The 1,610 cm{sup -1} band of aromatic structures with carboxylic groups increased its intensity. The wax hydrogen content doubled and H/O increased by 1/3-1/4. 12 refs.

  20. Biodegradation of paraffin wax by crude Aspergillus enzyme preparations for potential use in removing paraffin deposits.

    Science.gov (United States)

    Zhang, Junhui; Xue, Quanhong; Gao, Hui; Wang, Ping

    2015-11-01

    Paraffin deposition problems have plagued the oil industry. Whist mechanical and chemical methods are problematic, microbiological method of paraffin removal is considered an alternative. However, studies have mainly investigated the use of bacteria, with little attention to the potential of fungi. The performance of six Aspergillus isolates to degrade paraffin wax was evaluated under laboratory conditions using solid enzyme preparations. The results showed that all the six enzyme preparations efficiently improved the solubility of paraffin wax in n-hexane and degraded n-alkanes in paraffin wax. The degradation process was accompanied by dynamic production of gases (CO2 and H2 ) and organic acids (oxalate and propionate). The shape of wax crystals markedly changed after enzymatic degradation, with a rough surface and a loose structure. This study indicates that extracellular enzymes from Aspergillus spp. can efficiently degrade paraffin wax. These enzyme preparations have the potential for use in oil wells with paraffin deposition problems. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. [Use of entomopathogenic fungi to degrade wax secreted by Ceroplastes japonicus].

    Science.gov (United States)

    Zhang, Zhijuan; Xie, Yingping; Xue, Jiaoliang; Fan, Jinhua

    2013-05-04

    We used entomopathogenic fungi to degrade insect wax. We used four fungal strains, Lecanicilliurn lecanii V3. 4504, V3. 4505, Beauveria bassiana FDB01, and Metarhizium anisopliae TSL06. Wax coverings of female adults of Ceroplastes japonicus Green (Insecta: Hemiptera: Coccoidea) were used as the sole carbon source in the mineral medium. All of the 4 strains could grow, reproduce, produce enzymes, and degrade wax. During a 7-day culture, the highest lipase activities of the 4 strains, V3. 4504, V3. 4505, FDB01, and TSL06 were 0.128 +/- 0.017, 0.056 +/- 0.002, 0.124 +/- 0.011, and 0.149 +/- 0.005 U/mL, respectively. The dehydrogenases activities of the 4 strains were 0.075 +/- 0.003, 0.074 +/- 0.003, 0.061 +/- 0.04, and 0. 066 +/- 0. 002 U/mL respectively. The degradation rates of wax by the 4 strains were 18.20 +/- 0.019, 11.00 +/- 0.011, 15.4 +/- 0.017, and 23.10 +/- 0.031%, respectively. The 4 strains could depredate wax of C. japonicus.

  2. Preparation and properties of polystyrene encapsulated paraffin wax as possible phase change material in a polypropylene matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mochane, M.J. [Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba (South Africa); Luyt, A.S., E-mail: LuytAS@qwa.ufs.ac.za [Department of Chemistry, University of the Free State (Qwaqwa Campus), Phuthaditjhaba (South Africa)

    2012-09-20

    Highlights: Black-Right-Pointing-Pointer Polystyrene microcapsules containing about 30 wt% soft paraffin wax were successfully prepared. Black-Right-Pointing-Pointer The presence of microcapsules in polypropylene influenced the morphology and properties of the matrix. Black-Right-Pointing-Pointer The SEBS modifier had little influence on the interaction between polypropylene and microcapsules. - Abstract: The study deals with the preparation and characterization of polystyrene (PS) capsules containing Fischer-Tropsch paraffin wax (PS:wax) as phase change material (PCM) for thermal energy storage embedded in a polypropylene (PP) matrix. Blends of PP/PS:wax were prepared without and with polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene (SEBS) as a modifier. The influence of PS:wax microcapsules on the morphology, as well as thermal and mechanical properties of the PP was investigated. The scanning electron microscopy (SEM) images of the microencapsulated PCM show that the capsules were grouped in irregular spherical agglomerates of size 16-24 {mu}m. However, after melt-blending with PP smaller, perfectly spherical microcapsules were well dispersed in the PP matrix. There was fairly good interaction between the microcapsules and the matrix, even in the absence of SEBS modification. The FTIR spectrum of the microcapsules is almost exactly the same as that of polystyrene, which indicates that the microcapsules were mostly intact and that the FTIR only detected the polystyrene shell. The amount of wax in the PS:wax microcapsules was determined as 20-30% by weight. An increase in PS:wax content resulted in a decrease in the melting peak temperatures of PP. The thermal stability of the blends decreased with an increase in PS:wax microcapsules content as a consequence of the lower thermal stability of both the wax and PS. There was a drop in storage modulus with increasing PS:wax microcapsules content.

  3. 'Wax bloom' on beeswax cultural heritage objects: Exploring the causes of the phenomenon.

    Science.gov (United States)

    Bartl, B; Kobera, L; Drábková, K; Ďurovič, M; Brus, J

    2015-07-01

    The term 'wax bloom' is used to describe a thin whitish crystalline layer that develops on the surface of beeswax objects under specific conditions. This phenomenon is undesirable, especially in the cases of objects with aesthetic or informational value, such as wax sculptures or historical seals. A combination of solid-state NMR and FTIR measurements allowed to obtain fairly detailed insight into the problem and to suggest a probable mechanism of its development. Secondary crystallization of unsaturated hydrocarbons from beeswax was determined as a primary cause. After the macroscopic solidification of beeswax from the melt, these molecules remain for months in a highly mobile, liquid-like state. This facilitates their diffusion to the surface, where they eventually crystallize, forming the 'wax bloom' effect. Although these results are of particular interest with respect to the conservation of beeswax artifacts, they are relevant to this material in general and help with understanding its unique properties. Copyright © 2015 John Wiley & Sons, Ltd.

  4. Retained bone wax on CT at one year after dacryocystorhinostomy: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seung Hyun; Park, Dong Woo; Jeong, Jin Yeok [Guri Hospital, Hanyang University College of Medicine, Guri (Korea, Republic of); Lee, Jong Ah; Lee, Young Jun [Dept. of Radiology, Seoul Hospital, Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2015-09-15

    A 71-year-old man with chronic rhinosinusitis presented with a purulent, foul-smelling nasal discharge and obstruction. One year earlier he had been treated with a dacryocystorhinostomy for nasolacrimal duct obstruction. During the procedure, bone wax had been used to control bleeding in the anterior upper nasal cavity. On computed tomographic imaging, a fat-density lesion was seen in the anterior upper sinonasal cavity and was found to be hypointense or signal-void on all magnetic resonance imaging sequences. The lesion, which proved to consist of bone wax, was surgically removed. Here, we present the imaging features of retained bone wax in a patient with clinically diagnosed chronic rhinosinusitis after dacryocystorhinostomy.

  5. Procedures for extraction and purification of leaf wax biomarkers from peats

    Directory of Open Access Journals (Sweden)

    J.E. Nichols

    2011-12-01

    Full Text Available Palaeoecological and palaeoclimate reconstruction, using leaf wax biomarkers, is a relatively new sub-discipline of peatland science. The ability to process large numbers of samples rapidly for biomarkers makes this type of analysis particularly appealing. This review is a guide to the preparation of leaf waxes for analysis by gas chromatography. The main phases of preparation are extraction of soluble organic compounds from sediment, separation of the total extract into fractions of differing polarity, and the derivatisation of polar functional groups. The procedures described here are not meant be exhaustive of all organic geochemical possibilities in peatlands, but a distillation of methods for the preparation of leaf waxes that are commonly and increasingly being used in palaeoecological and palaeoclimatological studies.

  6. An alternative protocol for DNA extraction from formalin fixed and paraffin wax embedded tissue.

    Science.gov (United States)

    Coura, R; Prolla, J C; Meurer, L; Ashton-Prolla, P

    2005-08-01

    DNA extraction from paraffin wax embedded tissue requires special protocols, and most described methods report an amplification success rate of 60-80%. To propose a simple and inexpensive protocol consisting of xylene/ethanol dewaxing, followed by a kit based extraction. Xylene/ethanol dewaxing was followed by a long rehydration step and a kit based DNA extraction step. This method produced a 100% amplification success rate for fragments of 121 to 227 bp for tamponated formalin fixed paraffin wax embedded tissue. This cost effective and non-laborious protocol can successfully extract DNA from tamponated formalin fixed paraffin wax embedded tissue and should facilitate the molecular analysis of a large number of archival specimens in retrospective studies.

  7. Isolation and antimicrobial evaluation of isomeric hydroxy ketones in leaf cuticular waxes of Annona squamosa.

    Science.gov (United States)

    Shanker, K Shiva; Kanjilal, S; Rao, B V S K; Kishore, K Hara; Misra, S; Prasad, R B N

    2007-01-01

    A novel natural compound, 11-hydroxy-16-hentriacontanone, has been isolated from the leaf cuticular wax of Annona squamosa along with its known isomer 10-hydroxy-16-hentriacontanone in a ratio of 67:33. This isomeric mixture of hydroxy ketones constituted together 16.5% of the total cuticular waxes. The new compound was characterised using spectral and chromatographic techniques. The major component was found to be 16-hentriacontanone (palmitone), which constituted up to 48% of the total cuticular wax, together with a homologous series of hydrocarbons, fatty aldehydes, fatty alcohols, fatty acids and sterols as minor components. The antimicrobial activity of the isomeric hydroxy ketones was tested against selected Gram-positive and Gram-negative bacterial strains, and also some selected fungal strains, and compared with palmitone. The antibacterial activity of palmitone was significantly higher than that of the isomeric hydroxy ketones, but their antifungal activities were comparable.

  8. The analysis of the wax foundry models fabrication process for the CPX3000 device

    Directory of Open Access Journals (Sweden)

    G. Budzik

    2011-04-01

    Full Text Available The paper presents possibilities of creating wax founding models by means of CPX3000 device. The device is used for Rapid Prototypingof models made of foundry wax in an incremental process. The paper also presents problems connected with choosing technologicalparameters for incremental shaping which influence the accuracy of created models. Issues connected with post-processing are alsodescribed. This process is of great importance for obtaining geometrically correct models. The analysis of parameters of cleaning models from supporting material is also presented. At present CPX3000 printer is the first used in Poland device by 3D Systems firm for creating wax models. The printer is at The Faculty of Mechanical Engineering at Rzeszów University of Technology.

  9. Printed wax masks for 254 nm deep-UV pattering of PMMA-based microfluidics

    KAUST Repository

    Fan, Yiqiang

    2012-01-13

    This paper reports a new technique for masking deep-UV exposure of poly(methyl methacrylate) (PMMA) using a printed wax mask. This technique provides an inexpensive and bulk fabrication method for PMMA structures. The technique involves the direct printing of the mask onto a polymer sheet using a commercial wax printer. The wax layer was then transferred to a PMMA substrate using a thermal laminator, exposed using deep-UV (with a wavelength of 254 nm), developed in an IPA:water solution, and completed by bonding on a PMMA cap layer. A sample microfluidic device fabricated with this method is also presented, with the microchannel as narrow as 50 μm. The whole process is easy to perform without the requirement for any microfabrication facilities. © 2012 IOP Publishing Ltd.

  10. Development of a Parafin Wax deposition Unit for Fused Deposition Modelling (FDM)

    DEFF Research Database (Denmark)

    D'Angelo, Greta; Hansen, Hans Nørgaard; Pedersen, David Bue

    2014-01-01

    During the last decade Additive Manufacturing (AM) witnessed a big development in terms of technologies, processes and possibilities. However of materials and their use still represents a big challenge. In fact availability of materials is rather limited if compared to conventional manufacturing...... parts to subsequently use in a Lost Wax Casting process, multi-material Additive Manufacturing and the use of wax as support material during the production of complicated parts. Moreover it is believed that including waxes among the materials usable in FDM would promote new ways of using and exploring...... are tested iteratively by alternating different methods in order to find the best configuration. The use of an open source platform, namely a Reprap Prusa Mendel allows to perform quick changes to the system without significant modifications to the major frame of the machine. During the design of the new...

  11. Solution X-ray scattering (S/WAXS) and structure formation in protein dynamics

    CERN Document Server

    Nasedkin, Alexandr; Niemi, Antti J; Peng, Xubiao

    2016-01-01

    We propose to develop mean field theory in combination with Glauber algorithm, to model and interpret protein dynamics and structure formation in small to wide angle x-ray scattering (S/WAXS) experiments. We develop the methodology by analysing the Engrailed homeodomain protein as an example. We demonstrate how to interpret S/WAXS data with a good precision and over an extended temperature range. We explain experimentally observed phenomena in terms of protein phase structure, and we make predictions for future experiments how the scattering data behaves at different ambient temperature values. We conclude that a combination of mean field theory with Glauber algorithm has the potential to develop into a highly accurate, computationally effective and predictive tool for analysing S/WAXS data. Finally, we compare our results with those obtained previously in an all-atom molecular dynamics simulation.

  12. Zero birefringence films of pullulan ester derivatives

    Science.gov (United States)

    Danjo, Takahiro; Enomoto, Yukiko; Shimada, Hikaru; Nobukawa, Shogo; Yamaguchi, Masayuki; Iwata, Tadahisa

    2017-04-01

    High-performance films with almost zero-birefringence and zero-wavelength dispersion were succeeded to prepare from pullulan esters derivatives (PLEs) without any additives. Optical transmittance analysis, birefringence measurement of PLE cast film and hot stretched films, and infrared dichroism analysis were conducted to characterize optical properties of PLE films comparing with cellulose triacetate which is commercially used as low-birefringence in optical devices. The aims of this study, characterization of optical properties of pullulan esters, can develop a deep understanding of the fundamental knowing and applicability of polysaccharides. Accordingly, authors believe this paper will open the gate for researches in the application of polysaccharides.

  13. Co-metabolism of DDT by the newly isolated bacterium, Pseudoxanthomonas sp. wax

    Directory of Open Access Journals (Sweden)

    Guangli Wang

    2010-06-01

    Full Text Available Microbial degradation of 1,1,1-trichloro-2,2-bis(p-chlorophenylethane (DDT is the most promising way to clean up DDT residues found in the environment. In this paper, a bacterium designated as wax, which was capable of co-metabolizing DDT with other carbon sources, was isolated from a long-term DDT-contaminated soil sample by an enrichment culture technique. The new isolate was identified as a member of the Pseudoxanthomonas sp., based on its morphological, physiological and biochemical properties, as well as by 16S rRNA gene analysis. In the presence of 100 mg l-1 glucose, the wax strain could degrade over 95% of the total DDT, at a concentration of 20 mg l-1, in 72 hours, and could degrade over 60% of the total DDT, at a concentration of 100 mg l-1, in 144 hours. The wax strain had the highest degradation efficiency among all of the documented DDT-degrading bacteria. The wax strain could efficiently degrade DDT at temperatures ranging from 20 to 37ºC, and with initial pH values ranging from 7 to 9. The bacterium could also simultaneously co-metabolize 1,1-dichloro-2,2-bis(p-chlorophenylethane (DDD, 2,2-bis(p-chlorophenyl-1,1-dichlorethylene (DDE, and other organochlorine compounds. The wax strain could also completely remove 20 mg kg-1 of DDT from both sterile and non-sterile soils in 20 days. This study demonstrates the significant potential use of Pseudoxanthomonas sp. wax for the bioremediation of DDT in the environment.

  14. Review of data on the dermal penetration of mineral oils and waxes used in cosmetic applications.

    Science.gov (United States)

    Petry, T; Bury, D; Fautz, R; Hauser, M; Huber, B; Markowetz, A; Mishra, S; Rettinger, K; Schuh, W; Teichert, T

    2017-10-05

    Mineral oils and waxes used in cosmetic products, also referred to as "personal care products" outside the European Union, are mixtures of predominantly saturated hydrocarbons consisting of straight-chain, branched and ring structures with carbon chain lengths greater than C16. They are used in skin and lip care cosmetic products due to their excellent skin tolerance as well as their high protecting and cleansing performance and broad viscosity options. Recently, concerns have been raised regarding potential adverse health effects of mineral oils and waxes from dermal application of cosmetics. In order to be able to assess the risk for the consumer the dermal penetration potential of these ingredients has to be evaluated. The scope and objective of this review are to identify and summarize publicly available literature on the dermal penetration of mineral oils and waxes as used in cosmetic products. For this purpose, a comprehensive literature search was conducted. A total of 13 in vivo (human, animal) and in vitro studies investigating the dermal penetration of mineral oils and waxes has been identified and analysed. The majority of the substances were dermally adsorbed to the stratum corneum and only a minor fraction reached deeper skin layers. Overall, there is no evidence from the various studies that mineral oils and waxes are percutaneously absorbed and become systemically available. Thus, given the absence of dermal uptake, mineral oils and waxes as used in cosmetic products do not present a risk to the health of the consumer. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  15. The effects of surgicel and bone wax hemostatic agents on bone healing: An experimental study

    Directory of Open Access Journals (Sweden)

    Nasser Nooh

    2014-01-01

    Full Text Available Background: The biological effects of hemostatic agends on the physiological healing process need to be tested. The aim of this study was to assess the effects of oxidized cellulose (surgicel and bone wax on bone healing in goats′ feet. Materials and Methods: Three congruent circular bone defects were created on the lateral aspects of the right and left metacarpal bones of ten goats. One defect was left unfilled and acted as a control; the remaining two defects were filled with bone wax and surgicel respectively. The 10 animals were divided into two groups of 5 animals each, to be sacrificed at the 3rd and 5th week postoperatively. Histological analysis assessing quality of bone formed and micro-computed tomography (MCT measuring the quantities of bone volume (BV and bone density (BD were performed. The results of MCT analysis pertaining to BV and BD were statistically analyzed using two-way analysis of variance (ANOVA and posthoc least significant difference tests. Results: Histological analysis at 3 weeks showed granulation tissue with new bone formation in the control defects, active bone formation only at the borders for surgicel filled defects and fibrous encapsulation with foreign body reaction in the bone wax filled defects. At 5 weeks, the control and surgicel filled defects showed greater bone formation; however the control defects had the greatest amount of new bone. Bone wax filled defects showed very little bone formation. The two-way ANOVA for MCT results showed significant differences for BV and BD between the different hemostatic agents during the two examination periods. Conclusion: Surgicel has superiority over bone wax in terms of osseous healing. Bone wax significantly hinders osteogenesis and induces inflammation.

  16. Application conditions for ester cured alkaline phenolic resin sand

    Directory of Open Access Journals (Sweden)

    Ren-he Huang

    2016-07-01

    Full Text Available Five organic esters with different curing speeds: propylene carbonate (i.e. high-speed ester A; 1, 4-butyrolactone; glycerol triacetate (i.e. medium-speed ester B; glycerol diacetate; dibasic ester (DBE (i.e. low-speed ester C, were chosen to react with alkaline phenolic resin to analyze the application conditions of ester cured alkaline phenolic resin. The relationships between the curing performances of the resin (including pH value, gel pH value, gel time of resin solution, heat release rate of the curing reaction and tensile strength of the resin sand and the amount of added organic ester and curing temperature were investigated. The results indicated the following: (1 The optimal added amount of organic ester should be 25wt.%-30wt.% of alkaline phenolic resin and it must be above 20wt.%-50 wt.% of the organic ester hydrolysis amount. (2 High-speed ester A (propylene carbonate has a higher curing speed than 1, 4-butyrolactone, and they were both used as high-speed esters. Glycerol diacetate is not a high-speed ester in alkaline phenolic resin although it was used as a high-speed ester in ester cured sodium silicate sand; glycerol diacetate and glycerol triacetate can be used as medium-speed esters in alkaline phenolic resin. (3 High-speed ester A, medium-speed ester B (glycerol triacetate and low-speed ester C (dibasic ester, i.e., DBE should be used below 15 ìC, 35 ìC and 50 ìC, respectively. High-speed ester A or low-speed ester C should not be used alone but mixed with medium-speed ester B to improve the strength of the resin sand. (4 There should be a suitable solid content (generally 45wt.%-65wt.% of resin, alkali content (generally 10wt.%-15wt.% of resin and viscosity of alkaline phenolic resin (generally 50-300 mPa≤s in the preparation of alkaline phenolic resin. Finally, the technique conditions of alkaline phenolic resin preparation and the application principles of organic ester were discussed.

  17. Release kinetics of salbutamol sulphate from wax coated microcapsules and tableted microcapsules.

    Science.gov (United States)

    Raghuvanshi, R S; Tripathi, K P; Jayaswal, S B; Singh, J

    1992-01-01

    Microcapsules of salbutamol sulphate were prepared using beeswax and carnauba wax as coating materials. In vitro release kinetics were studied following the zero order, first order and Higuchi equations. Beeswax alone was not effective but beeswax and carnauba wax combinations were suitable in controlling the in vitro release of the drug. Microcapsules were compressed into tablets to get a controlled release oral dosage form. Release from tableted microcapsules was significantly more prolonged than the respective batches of the microcapsules. Best data fit with the highest correlation coefficient for the tableted microcapsules was obtained for first order.

  18. Cuticular wax accumulation is associated with drought tolerance in wheat near-isogenic lines

    Directory of Open Access Journals (Sweden)

    Jianmin Song

    2016-11-01

    Full Text Available Previous studies have shown that wheat grain yield is seriously affected by drought stress, and leaf cuticular wax is reportedly associated with drought tolerance. However, most studies have focused on cuticular wax biosynthesis and model species. The effects of cuticular wax on wheat drought tolerance have rarely been studied. The aims of the current study were to study the effects of leaf cuticular wax on wheat grain yield under drought stress using the above-mentioned wheat NILs and to discuss the possible physiological mechanism of cuticular wax on high grain yield under drought stress. Compared to water-irrigated (WI conditions, the cuticular wax content (CWC in glaucous and non-glaucous NILs under drought-stress (DS conditions both increased; mean increase values were 151.1% and 114.4%, respectively, which was corroborated by scanning electronic microscopy images of large wax particles loaded on the surfaces of flag leaves. The average yield of glaucous NILs was higher than that of non-glaucous NILs under DS conditions in 2014 and 2015; mean values were 7368.37 kg·ha-1 and 7103.51 kg·ha-1. This suggested that glaucous NILs were more drought-tolerant than non-glaucous NILs (P = 0.05, which was supported by the findings of drought tolerance indices TOL and SSI in both years, the relatively high water potential and relative water content, and the low ELWL. Furthermore, the photosynthesis rate (Pn of glaucous and non-glaucous wheat NILs under DS conditions decreased by 7.5% and 9.8%, respectively; however, glaucous NILs still had higher mean values of Pn than those of non-glaucous NILs, which perhaps resulted in the higher yield of glaucous NILs. This could be explained by the fact that glaucous NILs had a smaller Fv/Fm reduction, a smaller PI reduction and a greater ABS/RC increase than non-glaucous NILs under DS conditions. This is the first report to show that wheat cuticular wax accumulation is associated with drought tolerance. Moreover

  19. In search of low cost biological analysis: Wax or acrylic glue bonded paper microfluidic devices

    KAUST Repository

    Kodzius, Rimantas

    2011-01-22

    In this body of work we have been developing and characterizing paper based microfluidic fabrication technologies to produce low cost biological analysis. Specifically we investigated the performance of paper microfluidics that had been bonded using wax or acrylic glue, and characterized the affect of these and other microfluidic materials on the polymerase chain reaction (PCR). We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax or cyanoacrylate-based resin as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes. The hot-melt adhesive wax or simple cyanoacrylate-based resin can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate film, glass sheets, or metal plate. The wax bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by evacuating the channels of adhesive material in a hot-water. We applied the wax-paper based microfluidic chip to HeLa cell electroporation. Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein recombinant E. coli bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration. The chip bonded with cyanoacrylate-based resin was tested by measuring protein concentration and carrying out DNA capillary electrophoresis. To study the biocompatibility and applicability of our microfluidic chip fabrication technology, we tested the PCR compatibility of our chip materials along with various other common materials

  20. Enhanced ethanol production by removal of cutin and epicuticular waxes of wheat straw by plasma assisted pretreatment

    DEFF Research Database (Denmark)

    Kádár, Zsófia; Schultz-Jensen, Nadja; Jensen, J. S.

    2015-01-01

    as with Scanning Electron Microscopy (SEM) imaging. Compounds resulting from wax degradation were analyzed in the washing water of PAP wheat straw. The wax removal enhanced enzymatic hydrolysis yield and, consequently, the efficiency of wheat straw conversion into ethanol. In total, PAP increased the conversion...

  1. Geometrical effects of conventional and digital prosthodontic planning wax-ups on lateral occlusal contact number, contact area, and steepness.

    Science.gov (United States)

    Abduo, Jaafar

    2017-01-01

    This study evaluated and compared the effect of conventional and digital wax-ups on three lateral occlusion variables: contact number, contact area, and steepness. Dental casts of 10 patients with Angle Class I relationship were included in the study. All patients required fixed prosthodontic treatment that would affect lateral occlusion. The casts of all patients received conventional and digital wax-ups. For pretreatment, conventional wax-up, and digital wax-up casts, contact number, contact area, and occlusion steepness were measured at four lateral positions, that is, at excursions of 0.5, 1.0, 2.0, and 3.0 mm from maximal intercuspation. Lateral occlusion scheme variables were affected by use of diagnostic wax-ups. For all types of casts, contact number decreased as excursion increased. The two types of wax-ups had similar contact number patterns, and contact number was significantly greater for these casts than for pretreatment casts in the earlier stages of excursion. Similarly, contact area gradually decreased with increasing excursion in the pretreatment and conventional and digital wax-up casts. There was only a minimal decrease in occlusion steepness as excursion increased. However, lateral occlusion was generally steeper for digital wax-up casts.

  2. Synthesis of various kinds of esters by four microbial lipases.

    Science.gov (United States)

    Okumura, S; Iwai, M; Tsujisaka, Y

    1979-10-26

    Ester synthesis by microbial lipases, using homogeneous enzyme preparations, were investigated. The amount of synthesized ester was estimated by alkalimetry, and products were identified by thin-layer chromatography and infrared spectroscopy. Lipases from Aspergillus niger, Rhizopus delemar, Geotrichum candidum and Penicillium cyclopium synthesized esters from oleic acid and various primary alcohols. Only Geotrichum candidum lipase synthesized esters of secondary alcohols. Esters of tertiary alcohols, phenols or sugar alcohols were not synthesized by any lipase. Rather high concentrations of alcohol were required to synthesize the esters of ethylene glycol, propylene glycol or trimethylene glycol. Lipases from Aspergillus niger and Rhizopus delemar synthesized oleyl esters of various fatty acids and some dibasic acids. In contrast, lipases from Geotrichum candidum and Penicillium cyclopium synthesized oleyl esters only from medium or long chain fatty acids.

  3. Ethyl ester production during brewery fermentation, a review

    OpenAIRE

    Saerens, Sofie; Thevelein, Johan; Delvaux, Freddy

    2008-01-01

    The production of volatile esters by yeast is of major industrial interest because the presence of these compounds determines the fruity aroma of fermented beverages, like beer and wine. The need to understand and control ester synthesis is driven by the fact that esters play a key role in the sensorial quality of these fermented alcoholic beverages. Especially in the brewery, problems with ester production have been encountered by the introduction of modern brewing practices, such as high-gr...

  4. Production and biological function of volatile esters in Saccharomyces cerevisiae

    OpenAIRE

    Saerens, Sofie M. G.; Delvaux, Freddy R; Verstrepen, Kevin J; Thevelein, Johan?M.

    2010-01-01

    Summary The need to understand and control ester synthesis is driven by the fact that esters play a key role in the sensorial quality of fermented alcoholic beverages like beer, wine and sake. As esters are synthesized in yeast via several complex metabolic pathways, there is a need to gain a clear understanding of ester metabolism and its regulation. The individual genes involved, their functions and regulatory mechanisms have to be identified. In alcoholic beverages, there are two important...

  5. Two New Phorbol Esters from Euphorbia bothae

    African Journals Online (AJOL)

    NICO

    esterification patterns around a common tigliane diterpene scaffold.3 We therefore anticipated that phorbol ester secondary metabolites were similarly responsible for inducing the irritant contact dermatitis which we experienced on handling speci- mens of E. bothae. 1H NMR analysis of extractives of E. bothae revealed a ...

  6. Ester: Vroulike durf binne 'n manlike bestel

    African Journals Online (AJOL)

    Test

    7 Jun 2011 ... koning gereël) die mooiste deelnemer daaraan as koningin in. Vasti se plek gekies moet word. Die boek dra die naam van die hooffiguur, die mooi Joodse meisie Ester, met wie die leser eers kennismaak nadat haar pleegvader Mordegai (binne sy Joodse geslagsregister en as weggevoerde banneling) ...

  7. Avocado and olive oil methyl esters

    Science.gov (United States)

    Biodiesel, the mono-alkyl esters of vegetable oils, animal fats or other triacylglycerol-containing materials and an alternative to conventional petroleum-based diesel fuel, has been derived from a variety of feedstocks. Numerous feedstocks have been investigated as potential biodiesel sources, incl...

  8. Naturally Occurring Cinnamic Acid Sugar Ester Derivatives

    Directory of Open Access Journals (Sweden)

    Yuxin Tian

    2016-10-01

    Full Text Available Cinnamic acid sugar ester derivatives (CASEDs are a class of natural product with one or several phenylacrylic moieties linked with the non-anomeric carbon of a glycosyl skeleton part through ester bonds. Their notable anti-depressant and brains protective activities have made them a topic of great interest over the past several decades. In particular the compound 3′,6-disinapoylsucrose, the index component of Yuanzhi (a well-known Traditional Chinese Medicine or TCM, presents antidepressant effects at a molecular level, and has become a hotspot of research on new lead drug compounds. Several other similar cinnamic acid sugar ester derivatives are reported in traditional medicine as compounds to calm the nerves and display anti-depression and neuroprotective activity. Interestingly, more than one third of CASEDs are distributed in the family Polygalaceae. This overview discusses the isolation of cinnamic acid sugar ester derivatives from plants, together with a systematic discussion of their distribution, chemical structures and properties and pharmacological activities, with the hope of providing references for natural product researchers and draw attention to these interesting compounds.

  9. Kui vanajumal haamri annaks / Ester Tuiksoo

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Põllumajandusminister Ester Tuiksoo vaatab tagasi ministeeriumi möödunud aasta tööle. Tema hinnangul on Rahvaliit valitsuskoalitsioonis ja põllumajandusministeeriumis hakkama saanud paremini kui oponendid oskasid oodata. Täidetud maaelupoliitilistest lubadustest, Rahvaliidu eesmärkidest

  10. Determination of Mass Spectrometric Sensitivity of Different Metalloporphyrin Esters Relative to Porphyrin Ester

    DEFF Research Database (Denmark)

    Larsen, Elfinn; Egsgaard, Helge; Møller, J.

    1977-01-01

    Quantitative determination of metalloporphyrin contamination in preparations of biologically important porphyrins was achieved mass spectrometrically by application of the integrated ion current technique. For this purpose, the relative molecular ion sensitivities of the contaminating metal...... complexes were determined from the ratios of the integrated molecular ion currents of a series of calibration samples containing a porphyrin ester and one of its metal complexes in known molar ratio. Complexes formed with divalent ions of Cu, Zn, Fe, Co and Ni of copro- as well as uro......-prophyrin permethylester were all found to have the same molecular ion sensitivities as their metal-free porphyrin ester. The relative metalloporphyrin ester content in a sample of porphyrin ester was thus obtained directly as the integrated ion current ratios of the normalized molecular ions. The preparation...

  11. Ester Tuiksoo - Eesti esimene naissoost põllumajandusminister / Ester Tuiksoo ; interv. Toomas Verrev

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2007-01-01

    Ametist lahkuv põllumajandusminister Ester Tuiksoo räägib saadud juhtimiskogemusest, Euroopa Liidu ühise põllumajanduspoliitika juurutamisest, rahvuskala valimisest, Rahvaliidu käekäigust parlamendivalimistel

  12. 40 CFR 721.3140 - Vinyl epoxy ester.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Vinyl epoxy ester. 721.3140 Section... Substances § 721.3140 Vinyl epoxy ester. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance vinyl epoxy ester (PMN P-85-527) is subject to reporting under this...

  13. Biocatalytic synthesis and antioxidant capacities of ascorbyl esters ...

    African Journals Online (AJOL)

    ... lipid oxidative degradation activities. It can be conclude that the derivative ascorbyl esters may be used as potential antioxidants in improving food quality and stability. Key words: Novozym 435, esterification, ascorbyl palmitate, unsaturated fatty acid ascorbyl ester, mixture of fatty acid ascorbyl esters, antioxidant activity.

  14. 40 CFR 721.329 - Halogenated benzyl ester acrylate (generic).

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated benzyl ester acrylate... Specific Chemical Substances § 721.329 Halogenated benzyl ester acrylate (generic). (a) Chemical substance... halogenated benzyl ester acrylate (PMN P-90-1527) is subject to reporting under this section for the...

  15. Biocatalytic synthesis and antioxidant capacities of ascorbyl esters ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-28

    Nov 28, 2011 ... available on the comparison of antioxidant activities of ascorbyl esters biosynthesized using alkyl ester, fatty acid and triglyceride as acyl donors. Therefore, this study focused on the enzymatic synthesis of L-ascorbyl acid fatty acid esters catalyzed by immobilized lipase from C. antarctica (Novozym 435) in.

  16. Celorbicol, isocelorbicol, and their esters: new sesquiterpenoids from Celastrus orbiculatus

    Energy Technology Data Exchange (ETDEWEB)

    Smith, C.R. Jr. (Dept. of Agriculture, Peoria, IL); Miller, R.W.; Weisleder, D.; Rohwedder, W.K.; Eickman, N.; Clardy, J.

    1976-10-01

    Esters of two new sesquiterpenoid polyalcohols - celorbicol and isocelorbicol - have been isolated from Celastrus orbiculatus. Structures of the parent alcohols have been established by x-ray crystallography, and those of the derived esters have been assigned by NMR spectroscopy. These compounds are structurally related to other polyesters and ester alkaloids from the Celastraceae, all of which are based on the dihydroagarofuran ring system.

  17. Poly(ester-anhydride):poly(beta-amino ester) micro- and nanospheres: DNA encapsulation and cellular transfection.

    Science.gov (United States)

    Pfeifer, Blaine A; Burdick, Jason A; Little, Steve R; Langer, Robert

    2005-11-04

    Poly(ester-anhydride) delivery devices allow flexibility regarding carrier dimensions (micro- versus nanospheres), degradation rate (anhydride versus ester hydrolysis), and surface labeling (through the anhydride functional unit), and were therefore tested for DNA encapsulation and transfection of a macrophage P388D1 cell line. Poly(l-lactic acid-co-sebacic anhydride) and poly(l-lactic acid-co-adipic anhydride) were synthesized through melt condensation, mixed with 25 wt.% poly(beta-amino ester), and formulated with plasmid DNA (encoding firefly luciferase) into micro- and nanospheres using a double emulsion/solvent evaporation technique. The micro- and nanospheres were then characterized (size, morphology, zeta potential, DNA release) and assayed for DNA encapsulation and cellular transfection over a range of poly(ester-anhydride) copolymer ratios. Poly(ester-anhydride):poly(beta-amino ester) composite microspheres (6-12 microm) and nanospheres (449-1031 nm), generated with copolymers containing between 0 and 25% total polyanhydride content, encapsulated plasmid DNA (>or=20% encapsulation efficiency). Within this polyanhydride range, poly(adipic anhydride) copolymers provided DNA encapsulation at an increased anhydride content (10%, microspheres; 10-25%, nanospheres) compared to poly(sebacic anhydride) copolymers (1%, microspheres and nanospheres) with cellular transfection correlating with the observed DNA encapsulation.

  18. Stem Cells

    Directory of Open Access Journals (Sweden)

    Madhukar Thakur

    2015-02-01

    Full Text Available Objective: The objective of this presentation is to create awareness of stem cell applications in the ISORBE community and to foster a strategy of how the ISORBE community can disseminate information and promote the use of radiolabeled stem cells in biomedical applications. Methods: The continued excitement in Stem Cells, in many branches of basic and applied biomedical science, stems from the remarkable ability of stem cells to divide and develop into different types of cells in the body. Often called as Magic Seeds, stem cells are produced in bone marrow and circulate in blood, albeit at a relatively low concentration. These virtues together with the ability of stem cells to grow in tissue culture have paved the way for their applications to generate new and healthy tissues and to replace diseased or injured human organs. Although possibilities of stem cell applications are many, much remains yet to be understood of these remarkable magic seeds. Conclusion: This presentation shall briefly cover the origin of stem cells, the pros and cons of their growth and division, their potential application, and shall outline some examples of the contributions of radiolabeled stem cells, in this rapidly growing branch of biomedical science

  19. Rearrangement of beta,gamma-unsaturated esters with thallium trinitrate: synthesis of indans bearing a beta-keto ester moiety

    Directory of Open Access Journals (Sweden)

    Silva Jr. Luiz F.

    2006-01-01

    Full Text Available The rearrangement of beta,gamma-unsaturated esters, such as 2-(3,4-dihydronaphthalen-1-yl-propionic acid ethyl ester, with thallium trinitrate (TTN in acetic acid leads to 3-indan-1-yl-2-methyl-3-oxo-propionic acid ethyl ester in good yield, through a ring contraction reaction. The new indans thus obtained feature a beta-keto ester moiety, which would be useful for further functionalization.

  20. Wax Modeling and Image Analysis for Classroom-Scale Lava Flow Simulations.

    Science.gov (United States)

    Rader, E. L.; Clarke, A. B.; Vanderkluysen, L.

    2016-12-01

    The use of polyethylene glycol wax (PEG 600) as an analog for lava allows for a visual representation of the complex physical process occurring in natural lava flows, including cooling, breakouts, and crust and lobe formation. We used a series of cameras positioned around a tank filled with chilled water as a lab bench to observe and quantify lava flow morphology and motion. A peristaltic pump connected to a vent at the base of the tank delivered dyed wax simulating effusive eruptions similar to those of Kilauea in Hawai`i. By varying the eruptive conditions such as wax temperature and eruption rate, students can observe how the crust forms on wax flows, how different textures result, and how a flow field evolves with time. Recorded footage of the same `eruption' can then be quantitatively analyzed using free software like ImageJ and Tracker to quantify time-series of spreading rate, change in height, and appearance of different surface morphologies. Additional dye colors can be added periodically to further illustrate how lava is transported from the vent to the periphery of a flow field (e.g., through a tube system). Data collected from this activity can be compared to active lava flow footage from Hawai`i and with numerical models of lava flow propagation, followed by discussions of the application of these data and concepts to predicting the behavior of lava in hazard management situations and interpreting paleomagnetic, petrologic, and mapping of older eruptions.

  1. Biochemical analysis of leaf waxes and thrips resistance in onion selections

    Science.gov (United States)

    Thrips (Thrips tabaci) is a serious insect pest of onion and is a vector for Iris yellow spot virus (IYSV). Lower amounts of epicuticular waxes on onion leaves have been associated with fewer thrips, less feeding damage, and lower incidence of IYSV. In this study, 10 onion selections that showed les...

  2. Wax co-cracking synergism of high density polyethylene to alternative fuels

    Directory of Open Access Journals (Sweden)

    Magdy Motawie

    2015-09-01

    Full Text Available Attempts have been made to understand the thermal degradation of high density polyethylene (HDPE and their combined co-cracking using different ratios of HDPE and petroleum wax under nitrogen atmosphere. We have conducted the experiments using HDPE as the raw material and petroleum wax as co-feed by at 400 and 450 °C reaction temperatures. The product distribution was noted along with reaction time of 0.5–3 h for the degradation. Thermal gravimetric analysis (TGA technique was used to measure the weight change of the feedstock as a function of temperature and time. Differential scanning calorimetry (DSC was used to determine the degradation temperature. Products were characterized using gas chromatography (GC and infrared spectroscopy (FTIR, some other standard physical methods were used to determine the main properties of the liquid products. Results show that the mixed plastic-wax samples could be converted into gases, gasoline, and middle distillate depending upon the composition of feed polymer/wax ratio. It was found that the products mostly consisted of paraffin and olefin compounds, with carbon numbers of C1–C4, C5–C9 and C10–C19 in the case of gases, gasoline and middle distillate respectively.

  3. Cross-linking of LDPE/wax blends by using dicumyl peroxide

    African Journals Online (AJOL)

    Igor Krupa

    Abstract. Thermal properties of cross-linked and uncross-linked LDPE/wax blends were investigated. The blends were prepared by thoroughly mixing the powdery ingredients, followed by pressing at 180 °C for ten minutes. The extent of cross-linking was determined by means of gravimetric analysis of the gel content of the ...

  4. GROWTH, YIELD AND POSTHARVEST QUALITY OF WAX APPLE AS AFFECTED BY NAPHTHALENE ACETIC ACID APPLICATION

    Directory of Open Access Journals (Sweden)

    MOHAMMAD MONERUZZAMAN KHANDAKER

    2015-06-01

    Full Text Available Results of this study represent the first report of the effect of Naphthalene Acetic Acid (NAA on the pre and post harvest quality of wax apple fruit. The wax apple trees were spray treated with 0, 5, 10 and 20 mg L-1 NAA under field conditions during 2008 to 2011. The experiments were carried out in Completely Randomized Design (CRD with six replications. Leaf chlorophyll content, chlorophyll fluorescence, photosynthetic yield, net photosynthetic rate, drymatter content of leaves and total soluble solids and K+content of wax apple fruits were significantly increased after treatments with 10 mg L-1. Polygalacturonase activity significantly decreased with NAA treatments. The application of 5 mg L-1 NAA increased 27% more bud and reduced 42% less fruit drop compared to the control. In addition, higher protein and phosphate synthase activity of leaves, fruit set, fruit growth, larger fruit size and yield were recorded in NAA treated plants. In storage, treated fruits exhibited higher TSS and firmness and less weight loss, browning, titratable acidity, respiration and ethylene production than the control. It is concluded that spraying with 5 and 10 mg L-1 NAA once a week under field conditions produced better fruit growth and yield of the wax apple and maintained better fruit quality in postharvest storage.

  5. Genetic mapping of Sbbmc, a major locus controlling the profuse wax trait of sorghum

    Science.gov (United States)

    Sorghum bicolor is one of the most valuable “fail safe” cereal crop species and is a rich repository of genes for abiotic stress tolerance that await discovery. As an example, Sorghum exhibits cuticle which produces profuse amount of epicuticular wax (bloom) on sheaths and leaves that serves as one...

  6. Antibacterial and antifungal effect of high pH and paraffin wax ...

    African Journals Online (AJOL)

    The antibacterial and antifungal effects of high pH (9, 10) and paraffin wax were determined. Determination of antibacterial and antifungal activity of the combined treatments was achieved by aerobic mesophilic count of bacteria and fungi on the surface of the tomatoes, peppers and oranges using serial dilution and pour ...

  7. The casting of western sculpture during the XIXth century: sand casting versus lost wax casting

    NARCIS (Netherlands)

    Beentjes, T.P.C.

    2014-01-01

    This paper will discuss research into bronze casting techniques as practiced during the XIXth and early XXth century. Both natural sand casting (fonte au sable naturel) and lost wax casting (fonte à la cire perdue) were employed during this period and sometimes rivalled for commissions. Before the

  8. Making Work: Demonstrating Thermodynamic Concepts with Solar-Powered Wax and Rubber Heat Engines

    Science.gov (United States)

    Appleyard, S. J.

    2007-01-01

    Construction details are provided for simple heat engines that use candle wax and elastomers as working substances. The engines are constructed using common household materials and can be easily constructed in a school classroom or at home. They work reliably and are useful tools for demonstrating the conversion of heat to mechanical work. They…

  9. Antibacterial and antifungal effect of high pH and paraffin wax ...

    African Journals Online (AJOL)

    GREGO

    2007-03-19

    Mar 19, 2007 ... 362. Hall DJ (1981). Innovation in Citrus Waxing. An overview. pp: 258– 263. Ihekoronye AI, Ngoddy PO (1985). Food Microorganisms and Food. Spoilage. Integrated Food Science and Technology for the Tropics. Macmillan Publishers, London. pp. 106–107. Jay JM (2003). Microbial Spoilage of Food.

  10. Plumage reflectance is not affected by preen wax composition in red knots Calidris canutus

    NARCIS (Netherlands)

    Reneerkens, J; Korsten, P

    It has recently been shown that sandpipers (Scolopacidae) abruptly switch the chemical composition of their preen gland secretions from mono- to diester waxes just before the period of courtship. The timing and context of the shift suggested that diesters could provide a visible quality signal

  11. Wax barrier for use with in situ processes for treating formations

    Energy Technology Data Exchange (ETDEWEB)

    Vinegar, Harold J.; Carter, Ernest E.; Son, Jaime Santos; Bai, Taixu; Khoda Verdian, Mohamad Fereydoon

    2010-04-27

    Methods for forming a barrier around at least a portion of a treatment area in a subsurface formation are described herein. A material including wax may be introduced into one or more wellbores. The material introduced into two or more wells may mix in the formation and congeal to form a barrier to fluid flow.

  12. Efficacy of wax matrix bait stations for Mediterranean Fruit Flies (Diptera: Tephritidae)

    Science.gov (United States)

    Tests were conducted that evaluated efficacy of wax matrix bait stations for Ceratitis capitata (Wiedemann) adults in Guatemala. Bait stations were exposed to outdoor conditions to determine effect of weathering on longevity as indicated by bait station age. Results of laboratory tests found that ba...

  13. Synthesis and Properties of a Lacquer Wax-Based Quarternary Ammonium Gemini Surfactant

    Directory of Open Access Journals (Sweden)

    Hongxia Chen

    2014-03-01

    Full Text Available Lacquer wax is an important fatty resource obtained from the mesocarp of the berries of Toxicodendron vernicifluum. In order to expand the applications of lacquer wax, we hydrolyzed it after establishing the best conditions for the acid-catalyzed hydrolysis using a Box-Behnken design. Then we synthesized a quarternary ammonium gemini surfactant by a three-step reaction. The surface properties of an aqueous solution of the final product were investigated. The optimum conditions were 9% catalyst, 100 °C of reaction temperature and 14 h of reaction time, while the maximum free fatty acids (FFA% was 99.67%. From the gas chromatography, the main fatty acids of the lacquer wax were palmitic, oleic and octadecanoic acid. The lacquer wax gemini surfactant was synthesized, and its structure was confirmed by IR and NMR. The experiments showed that the critical micelle concentration (CMC is 5 × 10−4 mol·L−1, the surface tension is 33.6 mN·m−1. When the content of surfactant was 0.1%, the separation time of 5 mL water was 10 min.

  14. Growth, yield and quality responses to gibberellic acid (GA3)of Wax ...

    African Journals Online (AJOL)

    Administrator

    2011-09-26

    Sep 26, 2011 ... anthocyanin content, total phenol and antioxidant activity was higher in GA3 treated fruits. From this study, it can be concluded that spraying with 50 mg/L GA3 once a week results in better yield and quality of jambu madu fruits under field conditions. Key words: Gibberellin, growth, quality, wax apple, yield.

  15. Association between food mixing ability and mandibular movements during chewing of a wax cube.

    Science.gov (United States)

    Yoshida, E; Fueki, K; Igarashi, Y

    2007-11-01

    The purpose of this study was to clarify whether masticatory movements during chewing of a wax cube associate with food mixing ability. Twenty-six dentate subjects (mean age 25.3 years) were directed to chew a two-coloured paraffin wax cube for 10 strokes on preferred chewing side. Mixing Ability Index (MAI) was determined from the colour mixture and shape of the chewed wax cube. MAI was employed as an estimate of food mixing ability. Mandibular movements during chewing of the wax cube were recorded using a six-degrees-of freedom jaw movements recording system, and motion of a lower incisal point of the mandible was computed. Twelve parameters of masticatory movements in relation to mandibular excursion, angle, velocity, cycle duration, duration of each phase were measured for each masticatory cycle. In addition, unilateral maximum biting was performed, and the maximum force during biting was measured using a force-transducer. A multiple regression analysis identified vertical amplitude, closing duration, closing angle and maximum bite force as significant predictors accounting for 63% of inter-subject variation (adjusted R(2)) in the MAI (P movements seem to have an influence on the MAI in dentate subjects.

  16. Investigation of Carnuba Wax as Matrix in the Formulation of Solid ...

    African Journals Online (AJOL)

    This study was carried out to investigate the drug entrapment efficiency, release potential and drug release mechanisms of solid lipid microparticles (SLMs) prepared with different concentrations of two non ionic surfactants using carnauba wax as the lipid matrix. SLMs were prepared by melt dispersion technique, whereby ...

  17. Role of epicuticular waxes in the susceptibility of cotton leaf curl ...

    African Journals Online (AJOL)

    Cotton leaf curl virus (CLCuV) is the causal agent of the damaging disease of cotton that is caused by number of begomaviruses and vectored by silver leaf whitefly. In the present study, an attempt was made by infecting Gossypium arboreum variety 786, its wax mutant GaWM3 along with Gossypium hirsutum MNH-93 with ...

  18. A prediction method for the wax deposition rate based on a radial basis function neural network

    Directory of Open Access Journals (Sweden)

    Ying Xie

    2017-06-01

    Full Text Available The radial basis function neural network is a popular supervised learning tool based on machinery learning technology. Its high precision having been proven, the radial basis function neural network has been applied in many areas. The accumulation of deposited materials in the pipeline may lead to the need for increased pumping power, a decreased flow rate or even to the total blockage of the line, with losses of production and capital investment, so research on predicting the wax deposition rate is significant for the safe and economical operation of an oil pipeline. This paper adopts the radial basis function neural network to predict the wax deposition rate by considering four main influencing factors, the pipe wall temperature gradient, pipe wall wax crystal solubility coefficient, pipe wall shear stress and crude oil viscosity, by the gray correlational analysis method. MATLAB software is employed to establish the RBF neural network. Compared with the previous literature, favorable consistency exists between the predicted outcomes and the experimental results, with a relative error of 1.5%. It can be concluded that the prediction method of wax deposition rate based on the RBF neural network is feasible.

  19. Thermodynamics Prediction of Wax Precipitation in Black Oil Using Regular Solution Model and Plus Fraction Characterization

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2013-01-01

    Full Text Available The precipitation of wax/solid paraffin during production, transportation, and processing of crude oil is a serious problem. It is essential to have a reliable model to predict the wax appearance temperature and the amount of solid precipitated at different conditions. This paper presents a work to predict the solid precipitation based on solid-liquid equilibrium with regular solution-molecular thermodynamic theory and characterization of the crude oil plus fraction. Due to the differences of solubility characteristics between solid and liquid phase, the solubility parameters of liquid and solid phase are calculated by a modified model. The heat capacity change between solid and liquid phase is considered and estimated in the thermodynamic model. An activity coefficient based thermodynamic method combined with two characteristic methods to calculate wax precipitation in crude oil, especially heavy oil, has been tested with experimental data. The results show that the wax appearance temperature and the amount of weight precipitated can be predicted well with the experimental data.

  20. Effect of Zeolite Treatment on the Blooming Behavior of Paraffin Wax in Natural Rubber Composites

    Directory of Open Access Journals (Sweden)

    Bryan B. Pajarito

    2016-06-01

    Full Text Available The blooming behavior of paraffin wax in natural rubber (NR composites was studied as function of zeolite treatment. Three types of zeolite treatment were treated as factors: acid activation using hydrochloric acid (HCl solution, ion exchange using tetradecyldimethyl amine (TDA chloride salt, and organic modification using glycerol monostearate (GMS. The zeolite was treated according to a 23 full factorial design of experiment. Attenuated total reflectance – Fourier transform infrared (ATR-FTIR spectroscopy was used to characterize the chemical structure of treated zeolite. Treated zeolite was applied as filler to NR composites deliberately compounded with high amount of paraff in wax. The amount of bloomed wax in surface of NR composite sheets was monitored with time at 50oC. Results show the bloom amount to be linear with the square root of time. NR composites reinforced with untreated, acid-activated, and ion-exchanged zeolite fillers indicate reduction in wax blooming as compared to unfilled NR. The bloom rate (slope and initial bloom (y-intercept were determined from the experimental plots. Analysis of variance (ANOVA shows the bloom rate to be signif icantly increased when zeolite fillers are treated with GMS. Meanwhile, initial bloom was significantly enhanced when zeolite fillers are treated with TDA chloride salt and GMS. The significant increase in bloom rate and initial bloom can be attributed to the softening of the NR matrix at high amounts of TDA chloride salt and GMS.

  1. Effect of Soil Moisture Management on the Quality of Wax apple

    African Journals Online (AJOL)

    Michael Chen

    On the other hand, the effect of FI treatment on soil available elements, the concentration of leaf elements and fruit color were all highest, and the fruit cracking percentage was lower than for other treatments in alluvial soil. To improve the quality of wax apple, it may be treated by different management of soil moisture for the ...

  2. Expanding the chemical diversity of natural esters by engineering a polyketide-derived pathway into Escherichia coli.

    Science.gov (United States)

    Menendez-Bravo, Simón; Comba, Santiago; Sabatini, Martín; Arabolaza, Ana; Gramajo, Hugo

    2014-07-01

    Microbial fatty acid (FA)-derived molecules have emerged as promising alternatives to petroleum-based chemicals for reducing dependence on fossil hydrocarbons. However, native FA biosynthetic pathways often yield limited structural diversity, and therefore restricted physicochemical properties, of the end products by providing only a limited variety of usually linear hydrocarbons. Here we have engineered into Escherichia coli a mycocerosic polyketide synthase-based biosynthetic pathway from Mycobacterium tuberculosis and redefined its biological role towards the production of multi-methyl-branched-esters (MBEs) with novel chemical structures. Expression of FadD28, Mas and PapA5 enzymes enabled the biosynthesis of multi-methyl-branched-FA and their further esterification to an alcohol. The high substrate tolerance of these enzymes towards different FA and alcohol moieties resulted in the biosynthesis of a broad range of MBE. Further metabolic engineering of the MBE producer strain coupled this system to long-chain-alcohol biosynthetic pathways resulting in de novo production of branched wax esters following addition of only propionate. Copyright © 2014 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  3. Sources and abundances of leaf waxes in aerosols in central Europe

    Science.gov (United States)

    Nelson, Daniel B.; Knohl, Alexander; Sachse, Dirk; Schefuß, Enno; Kahmen, Ansgar

    2017-02-01

    Atmospheric transport is an understudied mechanism for leaf wax hydrogen isotope applications that contributes to mobilizing and depositing these compounds on the surface of the Earth. While previous efforts have identified the importance of atmospheric leaf wax deposition in remote marine locations, the processes are not well constrained on land in temperate latitudes where lakes are common and sedimentary leaf wax hydrogen isotope values are an attractive tool for understanding past precipitation changes. This work presents results from a field study that was conducted in 2010 and 2011 at Hainich National Park, Germany in order to evaluate the quantity and sources of leaf waxes in the atmosphere. Aerosols were sampled at approximately weekly intervals inside the forest canopy, and n-alkane distributions and hydrogen isotope values were compared with those from major tree species surrounding the sampling site. Despite sampling in what was expected to be a major production center, the distribution and hydrogen isotope values of atmospheric n-alkanes bore little resemblance to those of the local vegetation. Comparison with local meteorological data and to 10-day and 36-h back air mass trajectories indicated shifting effects of winds and temperature, and that mesoscale transport processes were more important than long-range mechanisms. Back trajectories also highlighted source effects, with easterly winds coinciding with relatively lower leaf wax hydrogen isotope values from more continental regions. These results suggest that leaf wax aerosols average over spatial scales that exceed typical surface catchment areas for small lake systems, even in forested areas, yet that the area over which these compounds are derived is still relatively regional. Depositional fluxes were also estimated in order to assess the potential importance of atmospheric transport to sedimentary archives. Although difficult to constrain, these estimates suggest that atmospheric deposition may

  4. Virulence of serotype M3 Group A Streptococcus strains in wax worms (Galleria mellonella larvae)

    Science.gov (United States)

    Watkins, M Ebru; Cantu, Concepcion C; Beres, Stephen B; Musser, James M

    2011-01-01

    Group A Streptococcus (GAS) causes human infections that range in severity from pharyngitis (“strep-throat”) to necrotizing fasciitis (“flesh-eating disease”). To facilitate investigation of the molecular basis of host-pathogen interactions, infection models capable of rapidly screening for differences in GAS strain virulence are needed. To this end, we developed a Galleria mellonella larvae (wax worm) model of invasive GAS infection and used it to compare the virulence of serotype M3 GAS strains. We found that GAS causes severe tissue damage and kills wax worms in a dose-dependent manner. The virulence of genetically distinct GAS strains was compared by Kaplan-Meier survival analysis and determining 50% lethal doses (LD50). Host-pathogen interactions were further characterized using quantitative culture, histopathology and TaqMan assays. GAS strains known to be highly pathogenic in mice and monkeys caused significantly lower survival and had significantly lower LD50s in wax worms than GAS strains associated with attenuated virulence or asymptomatic carriage. Furthermore, isogenic inactivation of proven virulence factors resulted in a significantly increased LD50 and decreased lesion size compared to the wild-type strain, a finding that also strongly correlates with animal studies. Importantly, survival analysis and LD50 determination in wax worms supported our hypothesis that a newly emerged GAS subclone that is epidemiologically associated with more human necrotizing fasciitis cases than its progenitor lineage has significantly increased virulence. We conclude that GAS virulence in wax worms strongly correlates with the data obtained in vertebrate models, and thus, the Galleria mellonella larva is a useful host organism to study GAS pathogenesis. PMID:21258213

  5. Altitude effect on leaf wax carbon isotopic composition in humid tropical forests

    Science.gov (United States)

    Wu, Mong Sin; Feakins, Sarah J.; Martin, Roberta E.; Shenkin, Alexander; Bentley, Lisa Patrick; Blonder, Benjamin; Salinas, Norma; Asner, Gregory P.; Malhi, Yadvinder

    2017-06-01

    The carbon isotopic composition of plant leaf wax biomarkers is commonly used to reconstruct paleoenvironmental conditions. Adding to the limited calibration information available for modern tropical forests, we analyzed plant leaf and leaf wax carbon isotopic compositions in forest canopy trees across a highly biodiverse, 3.3 km elevation gradient on the eastern flank of the Andes Mountains. We sampled the dominant tree species and assessed their relative abundance in each tree community. In total, 405 sunlit canopy leaves were sampled across 129 species and nine forest plots along the elevation profile for bulk leaf and leaf wax n-alkane (C27-C33) concentration and carbon isotopic analyses (δ13C); a subset (76 individuals, 29 species, five forest plots) were additionally analyzed for n-alkanoic acid (C22-C32) concentrations and δ13C. δ13C values display trends of +0.87 ± 0.16‰ km-1 (95% CI, r2 = 0.96, p families, suggesting the biochemical response to environment is robust to taxonomic turnover. We calculate fractionations and compare to adiabatic gradients, environmental variables, leaf wax n-alkane concentrations, and sun/shade position to assess factors influencing foliar chemical response. For the 4 km forested elevation range of the Andes, 4-6‰ higher δ13C values are expected for upland versus lowland C3 plant bulk leaves and their n-alkyl lipids, and we expect this pattern to be a systematic feature of very wet tropical montane environments. This elevation dependency of δ13C values should inform interpretations of sedimentary archives, as 13C-enriched values may derive from C4 grasses, petrogenic inputs or upland C3 plants. Finally, we outline the potential for leaf wax carbon isotopes to trace biomarker sourcing within catchments and for paleoaltimetry.

  6. Rapid atmospheric transport and large-scale deposition of recently synthesized plant waxes

    Science.gov (United States)

    Nelson, Daniel B.; Ladd, S. Nemiah; Schubert, Carsten J.; Kahmen, Ansgar

    2018-02-01

    Sedimentary plant wax 2H/1H ratios are important tools for understanding hydroclimate and environmental changes, but large spatial and temporal uncertainties exist about transport mechanisms from ecosystem to sediments. To assess atmospheric pathways, we collected aerosol samples for two years at four locations within a ∼60 km radius in northern Switzerland. We measured n-alkane distributions and 2H/1H ratios in these samples, and from local plants, leaf litter, and soil, as well as surface sediment from six nearby lakes. Increased concentrations and 2H depletion of long odd chain n-alkanes in early summer aerosols indicate that most wax aerosol production occurred shortly after leaf unfolding, when plants synthesize waxes in large quantities. During autumn and winter, aerosols were characterized by degraded n-alkanes lacking chain length preferences diagnostic of recent biosynthesis, and 2H/1H values that were in some cases more than 100‰ higher than growing season values. Despite these seasonal shifts, modeled deposition-weighted average 2H/1H values of long odd chain n-alkanes primarily reflected summer values. This was corroborated by n-alkane 2H/1H values in lake sediments, which were similar to deposition-weighted aerosol values at five of six sites. Atmospheric deposition rates for plant n-alkanes on land were ∼20% of accumulation rates in lakes, suggesting a role for direct deposition to lakes or coastal oceans near similar production sources, and likely a larger role for deposition on land and transport in river systems. This mechanism allows mobilization and transport of large quantities of recently produced waxes as fine-grained material to low energy sedimentation sites over short timescales, even in areas with limited topography. Widespread atmospheric transfer well before leaf senescence also highlights the importance of the isotopic composition of early season source water used to synthesize waxes for the geologic record.

  7. Analog modeling of fault asperity kinematics using a modified squeezebox design and wax media

    Science.gov (United States)

    Martin, D. J.; Swain, T. C.; Paquette, P.; Mookerjee, M.; Acosta, T.

    2016-12-01

    Fault movement is strongly influenced by the physical characteristics of the fault surfaces. Fault surfaces are generally non-planar, and have a certain amount of roughness to them, which manifests as fault asperities. In order for a fault to continue moving along its preexisting surface, the asperities must either move past each other, which involve moving a large volume of rock around these obstacles, or create new fractures that "decapitate" and pulverize these asperities, ultimately leading to a smoother fault surface. We explore a new way to investigate fault asperity kinematics using a squeeze-box analog deformation rig. The more typical and classic squeeze-box model uses sand and/or clay to demonstrate fault and fold deformations. We have designed and built a new analog modeling rig that utilizes a dual wax analog model. One constituent is white spherical wax particles that have been embedded in a lower-melting-temperature black matrix wax. Deformation of the analog material is facilitated by the addition of heating elements lining the underside and exterior walls of the squeeze-box reservoir. An aluminum asperity is secured to the floor of the reservoir. Additional overburden is simulated with a polyethylene bag filled with lead shot that rest on the top surface of the wax block during deformation. Once the deformation experiment is completed, the wax block can be finely sectioned, polished and scanned in preparation for analysis. Here, we provide proof of concept by demonstrating that we were able to generate realistic looking deformation features at different strain rate and temperature model conditions.

  8. Flavor-active esters: adding fruitiness to beer.

    Science.gov (United States)

    Verstrepen, Kevin J; Derdelinckx, Guy; Dufour, Jean-Pierre; Winderickx, Joris; Thevelein, Johan M; Pretorius, Isak S; Delvaux, Freddy R

    2003-01-01

    As they are responsible for the fruity character of fermented beverages, volatile esters constitute an important group of aromatic compounds in beer. In modern high-gravity fermentations, which are performed in tall cylindroconical vessels, the beer ester balance is often sub-optimal, resulting in a clear decrease in beer quality. Despite the intensive research aimed at unravelling the precise mechanism and regulation of ester synthesis, our current knowledge remains far from complete. However, a number of factors that influence flavor-active ester production have already been described, including wort composition, wort aeration and fermentor design. A thoughtful adaptation of these parameters allows brewers to steer ester concentrations and thus to control the fruity character of their beers. This paper reviews the current knowledge of the biochemistry behind yeast ester synthesis and discusses the different factors that allow ester formation to be controlled during brewery fermentation.

  9. A new class of mealybug pheromones: a hemiterpene ester in the sex pheromone of Crisicoccus matsumotoi

    Science.gov (United States)

    Tabata, Jun; Narai, Yutaka; Sawamura, Nobuo; Hiradate, Syuntaro; Sugie, Hajime

    2012-07-01

    Mealybugs, which include several agricultural pests, are small sap feeders covered with a powdery wax. They exhibit clear sexual dimorphism; males are winged but fragile and short lived, whereas females are windless and less mobile. Thus, sex pheromones emitted by females facilitate copulation and reproduction by serving as a key navigation tool for males. Although the structures of the hitherto known mealybug pheromones vary among species, they have a common structural motif; they are carboxylic esters of monoterpene alcohols with irregular non-head-to-tail linkages. However, in the present study, we isolated from the Matsumoto mealybug, Crisicoccus matsumotoi (Siraiwa), a pheromone with a completely different structure. Using gas chromatography-mass spectrometry and nuclear magnetic resonance spectroscopy, we identified the pheromone as 3-methyl-3-butenyl 5-methylhexanoate. Its attractiveness to males was confirmed in a series of field trapping experiments involving comparison between the isolated natural product and a synthetic sample. This is the first report of a hemiterpene mealybug pheromone. In addition, the acid moiety (5-methylhexanoate) appears to be rare in insect pheromones.

  10. Effect of new type of synthetic waxes on reduced production and compaction temperature of asphalt mixture with reclaimed asphalt

    Science.gov (United States)

    Valentová, Tereza; Benešová, Lucie; Mastný, Jan; Valentin, Jan

    2017-09-01

    Lower mixing and paving temperatures of asphalt mixtures, which are an important issue in recent years, with respect to increased energy demand of civil engineering structures during their processing, allow reduction of this demand and result in minimized greenhouse gas production. In present time, there are many possibilities how to achieve reduction of production temperature during the mixing and paving of an asphalt mixture. The existing solutions distinguish in target operating temperature behaviour which has to be achieved in terms of good workability. This paper is focused on technical solutions based on use of new types of selected synthetic and bio-based waxes. In case of bio-based additive sugar cane wax was used, which is free of paraffins and is reclaimed as waste product during processing of sugar cane. The used waxes are added to bituminous binder in form of free-flowing granules or fine-grained powder. Synthetic waxes are represented by new series of Fischer-Tropsch wax in form of fine granules as well as by polyethylene waxes in form of fine-grained powder or granules. Those waxes were used to modify a standard paving grade bitumen dosed into asphalt mixture of ACsurf type containing up to 30 % of reclaimed asphalt (RA).

  11. Composição química da cera epicuticular e caracterização da superfície foliar em genótipos de cana-de-açúcar Chemical composition of epicuticular wax and characterization of leaf surface in sugarcane genotypes

    Directory of Open Access Journals (Sweden)

    E.A. Ferreira

    2005-12-01

    Full Text Available Objetivou-se neste trabalho avaliar a composição química da cera epicuticular e caracterizar a superfície foliar dos cultivares de cana-de-açúcar RB855113 (sensível à mistura de herbicidas trifloxysulfuron-sodium + ametryn, SP80-1842 e SP80-1816, do clone RB957689 (com média sensibilidade à mistura de herbicidas e do cultivar RB867515 (tolerante. A cera epicuticular foi extraída e quantificada e os seus constituintes analisados por cromatografia a gás, acoplada a espectrômetro de massa (CG-EM. Para determinação da composição química, assim como a caracterização da superfície foliar dos cultivares avaliados, amostras de lâmina foliar foram coletadas e submetidas à microscopia eletrônica de varredura, para caracterização das faces adaxial e abaxial. A análise das amostras revelou a presença de hidrocarbonetos, esteróides, ésteres graxos, álcoois e aldeídos. A cera do cultivar sensível à mistura (RB855113 apresentou menor número de componentes químicos e predominância de ésteres graxos de cadeia mais curta que os encontrados nos demais cultivares, bem como pequena proporção de esteróides e hidrocarbonetos. Nos cultivares com média sensibilidade (SP80-1842 e RB867515, a cera apresentou maior proporção de hidrocarbonetos e esteróides. A cera do cultivar RB855113 apresentou polaridade intermediária, porém menos polar que a cera do cultivar RB867515 (tolerante à mistura. Não foram observadas diferenças marcantes entre os cultivares no que se refere à micromorfologia foliar.This study aimed to evaluate the chemical composition of epicuticular wax and to characterize leaf surface in the sugarcane cultivars RB85113 (sensitive to trifloxysulfuron-sodium + ametryn, SP80 1842, SP80 1816, clone RB957689 (with medium sensitivity to trifloxysulfuron-sodium + ametryn and the cultivar RB867515 (tolerant. Epicuticular wax was extracted and quantified, and its contents submitted to gas chromatography coupled to a

  12. In situ immobilized lipase on the surface of intracellular polyhydroxybutyrate granules: preparation, characterization, and its promising use for the synthesis of fatty acid alkyl esters.

    Science.gov (United States)

    Yang, Taek Ho; Kwon, Min-A; Lee, Ji Young; Choi, Ji-Eun; Oh, Joon Young; Song, Jae Kwang

    2015-12-01

    Photobacterium lipolyticum M37 lipase (LipM37) was immobilized on the surface of intracellular polyhydroxybutyrate (PHB) granules in Escherichia coli. LipM37 was genetically fused to Cupriavidus necator PHA synthase (PhaC Cn ), and the engineered PHB operon containing the lip M37 -phaC Cn successfully mediated the accumulation of PHB granules (85 wt.%) inside E. coli cells. The PHB granules were isolated from the crude cell extract, and the immobilized LipM37 was comparable with the free form of LipM37 except for a favorable increase in thermostability. The immobilized LipM37 was used to synthesize oleic acid methyl ester (biodiesel) and oleic acid dodecyl ester (wax ester), and yielded 98.0 % conversion in esterification of oleic acid and dodecanol. It was suggested that the LipM37-PhaCCn fusion protein successfully exhibited bifunctional activities in E. coli and that in situ immobilization of lipase to the intracellular PHB could be a promising approach for expanding the biocatalytic toolbox for industrial chemical synthesis.

  13. Enzymatic synthesizing of phytosterol oleic esters.

    Science.gov (United States)

    Pan, Xinxin; Chen, Biqiang; Wang, Juan; Zhang, Xinzhi; Zhul, Biyun; Tan, Tianwei

    2012-09-01

    A method of synthesizing the phytosterol esters from oleic acid and sterols was studied, using immobilized lipase Candida sp. 99-125 as catalyst. Molar ratio (oleic acid/phytosterols), temperature, reaction period, organic solvents, catalyst, and silica-gel drier were optimized, and the result showed that 93.4% of the sterols had been esterified under the optimal synthetic condition: the molar ratio of oleic acid/phytosterol is 1:1 in 10 mL iso-octane, immobilized lipase (w, 140% of the sterols), incubated in an orbital shaker (200 rpm) at a temperature of 45 °C for 24 h. The immobilized lipase could be reused for at least 13 times with limited loss of esterification activity. The conversion still maintained up to 86.6%. Hence, this developed process for synthesizing phytosterol esters could be considered as simple and low-energy consumption compared to existing chemical processes.

  14. Atmospheric oxidation of selected alcohols and esters

    Energy Technology Data Exchange (ETDEWEB)

    Becker, K.H.; Cavalli, F.

    2001-03-01

    The decision whether it is appropriate and beneficial for the environment to deploy specific oxygenated organic compounds as replacements for traditional solvent types requires a quantitative assessment of their potential atmospheric impacts including tropospheric ozone and other photooxidant formation. This involves developing chemical mechanisms for the gasphase atmospheric oxidation of the compounds which can be reliably used in models to predict their atmospheric reactivity under a variety of environmental conditions. Until this study, there was very little information available concerning the atmospheric fate of alcohols and esters. The objectives of this study were to measure the atmospheric reaction rates and to define atmospheric reaction mechanisms for the following selected oxygenated volatile organic compounds: the alcohols, 1-butanol and 1-pentanol, and the esters, methyl propionate and dimethyl succinate. The study has successfully addressed these objectives. (orig.)

  15. New polyoxypregnane ester derivatives from Leptadenia hastata.

    Science.gov (United States)

    Aquino, R; Peluso, G; De Tommasi, N; De Simone, F; Pizza, C

    1996-06-01

    Following the characterization of polyoxypregnane esters and esterified glycosides from the less polar extracts of Leptadenia hastata, 34 new congeners have been isolated from the more polar extracts. They possess sarcostin or deacetylmetaplexigenin as the aglycons and acetyl, benzoyl, cinnamoyl, nicotinoyl, and m-hydroxybenzoyl residues as the ester moieties linked at C-12 and/or C-20 of the aglycons. The oligosaccharide moiety linked to C-3 of the aglycons was made up of three to five 2,6-dideoxy-3-O-methylpyranoses, 6-deoxy-3-O-methylpyranoses, or glucose. Their structures have been elucidated on the basis of spectral evidence. Glycosides with more complex oligosaccharidic chains were tested for their antitumor activity on Raji cells.

  16. Use of fumaric acid esters in psoriasis

    OpenAIRE

    Roll Antonie; Reich Kristian; Boer Almut

    2007-01-01

    Fumaric acid esters (FAE) are chemical compounds derived from the unsaturated dicarbonic acid fumaric acid. The usage of FAEs in treatment of psoriasis was introduced in the late 1950′s. In the 1980s more standardized oral preparations of FAEs were developed containing dimethylfumarate(DMF) and salts of monoethylfumarate(MEF) as main compounds. In 1994, Fumaderm ® an enteric-coated tablet containing DMF and calcium, magnesium, and zinc salts of MEF was approved for the treatment...

  17. Experimental investigations of thermophysical properties of some paraffin waxes industrially manufactured in Poland

    Science.gov (United States)

    Zbińkowski, Piotr; Zmywaczyk, Janusz; Koniorczyk, Piotr

    2017-07-01

    Phase-change materials (PCM) can be applied as a heat absorbing/releasing medium in passive cooling systems. Such systems can be used in cooling and temperature stabilization of electronic components, i.e., Li-ion batteries, photovoltaic modules or light emitting diodes (LED). In order to optimize heat transfer in passive cooling systems experimental studies of PCM thermophysical properties are necessary. A good PCM candidate for passive cooling systems may be paraffin waxes due to their relatively high latent heat of fusion (L 200 J.g-1), suitable for working of electronic devices range of melting temperatures (22 °C - 68 °C) and a reasonable price. However, their main drawback is a relatively low thermal conductivity k ranging from 0.148 W.m-1.K-1 to 0.358 W.m-1.K-1. In this paper were presented results of experimentally determined temperature characteristics of thermophysical parameters of four paraffin waxes industrially manufactured in Jasło/Poland by POLWAX. The density ρ of the test paraffin waxes determined at room temperature (20 °C) using a laboratory balance RADWAG X/60/220 comprised from 0.82 g.cm-3 to 0.94 g.cm-3. The thermal diffusivity κ of paraffin waxes was tested within temperature range from -50 °C to 30 °C every 20 °C interval using the NETZSCH LFA 467 HyperFlash. The test specimens having form of cylinder were 12.7 mm in diameter and 2.15 - 2.20 mm in height. Prior to the experiment the face and the back surface of each specimen were coated with a thin layer of graphite 33 having a thickness of several micrometers in accordance with the recommendation given by NETZSCH. The thermal diffusivity of the test paraffin waxes within temperature interval -40 °C - 20 °C was determined to be 0.083 mm2.s-1 to 0.216 mm2.s-1. Thermal effects and the apparent heat capacity cp of the tested materials were measured in the temperature range from -10 °C to 100 °C using the NETZSCH DSC 404 F1 Pegasus at 10 K.min-1 heating/cooling rates in an

  18. Synthetic Methods for Ester Bond Formation and Conformational Analysis of Ester-Containing Carbohydrates

    Science.gov (United States)

    Hackbusch, Sven

    This dissertation encompasses work related to synthetic methods for the formation of ester linkages in organic compounds, as well as the investigation of the conformational influence of the ester functional group on the flexibility of inter-saccharide linkages, specifically, and the solution phase structure of ester-containing carbohydrate derivatives, in general. Stereoselective reactions are an important part of the field of asymmetric synthesis and an understanding of their underlying mechanistic principles is essential for rational method development. Here, the exploration of a diastereoselective O-acylation reaction on a trans-2-substituted cyclohexanol scaffold is presented, along with possible reasons for the observed reversal of stereoselectivity dependent on the presence or absence of an achiral amine catalyst. In particular, this work establishes a structure-activity relationship with regard to the trans-2-substituent and its role as a chiral auxiliary in the reversal of diastereoselectivity. In the second part, the synthesis of various ester-linked carbohydrate derivatives, and their conformational analysis is presented. Using multidimensional NMR experiments and computational methods, the compounds' solution-phase structures were established and the effect of the ester functional group on the molecules' flexibility and three-dimensional (3D) structure was investigated and compared to ether or glycosidic linkages. To aid in this, a novel Karplus equation for the C(sp2)OCH angle in ester-linked carbohydrates was developed on the basis of a model ester-linked carbohydrate. This equation describes the sinusoidal relationship between the C(sp2)OCH dihedral angle and the corresponding 3JCH coupling constant that can be determined from a J-HMBC NMR experiment. The insights from this research will be useful in describing the 3D structure of naturally occurring and lab-made ester-linked derivatives of carbohydrates, as well as guiding the de novo-design of

  19. Tailored cellulose esters: synthesis and structure determination.

    Science.gov (United States)

    Liebert, Tim F; Heinze, Thomas

    2005-01-01

    A broad variety of cellulose esters with complex and sensitive (against hydrolysis and light) structures was synthesized homogeneously in N,N-dimethylacetamide (DMAc)/LiCl and in the new solvent dimethyl sulfoxide (DMSO)/tetrabutylammonium fluoride (TBAF) via in situ activation of the carboxylic acids with N,N'-carbonyldiimidazole (CDI). New esters of chiral (-)-menthyloxyacetic acid, of unsaturated 3-(2-furyl)-acrylcarboxylic- and furane-2-carboxylic acid, acids with crownether moieties (4'-carboxybenzo-18-crown-6), and with carboxymethyl-beta-cyclodextrin were accessible in a one-pot reaction. Because of the mild conditions and the efficiency of the reaction via imidazolides, very pure and highly functionalized cellulose derivatives were obtained up to a degree of substitution of 2.5 possessing a degree of polymerization in the range of the starting cellulose. Structure determination was carried out by different one- and two-dimensional NMR techniques confirming the high purity of the esters and a pronounced regioselectivity for the primary OH function. The structural features, the purity, the solubility, and the film forming properties, make these materials desired products for the preparation of membranes with tailored separation characteristics.

  20. Ethyl ester production from (RBD palm oil

    Directory of Open Access Journals (Sweden)

    Oscar Mauricio Martínez Ávila

    2010-07-01

    Full Text Available This work develops a methodology for obtaining ethyl esters from RBD (refined, bleached and deodorised palm oil by evaluating the oil’s transesterification and separation. Two catalysts were first tested (KOH and NaOH by studying the effect of water presence on the reaction. The separation process was then evaluated by using water and water-salt and water-acid mixtures, establishing the agent offering the best results and carrying out the purification stage. Raw materials and products were characterised for comparing the latter with those obtained by traditional means and verifying the quality of the esters so produced; minimum differences were found bet-ween both. The proposed methodology thus allows esters to be used as raw material in petrochemical industry applications. A more profitable process can be obtained compared to those used today, given the amounts of separation agent so established (1% H3PO4 solution, in water. The overall process achieved 74.4% yield, based on the oil being used.

  1. STEM Education.

    Science.gov (United States)

    Xie, Yu; Fang, Michael; Shauman, Kimberlee

    2015-08-01

    Improving science, technology, engineering, and mathematics (STEM) education, especially for traditionally disadvantaged groups, is widely recognized as pivotal to the U.S.'s long-term economic growth and security. In this article, we review and discuss current research on STEM education in the U.S., drawing on recent research in sociology and related fields. The reviewed literature shows that different social factors affect the two major components of STEM education attainment: (1) attainment of education in general, and (2) attainment of STEM education relative to non-STEM education conditional on educational attainment. Cognitive and social psychological characteristics matter for both major components, as do structural influences at the neighborhood, school, and broader cultural levels. However, while commonly used measures of socioeconomic status (SES) predict the attainment of general education, social psychological factors are more important influences on participation and achievement in STEM versus non-STEM education. Domestically, disparities by family SES, race, and gender persist in STEM education. Internationally, American students lag behind those in some countries with less economic resources. Explanations for group disparities within the U.S. and the mediocre international ranking of US student performance require more research, a task that is best accomplished through interdisciplinary approaches.

  2. Stem Cells

    DEFF Research Database (Denmark)

    Sommerlund, Julie

    2004-01-01

    '. This paper is about tech-noscience, and about the proliferation of connections and interdependencies created by it.More specifically, the paper is about stem cells. Biotechnology in general has the power to capture the imagination. Within the field of biotechnology nothing seems more provocative...... and tantalizing than stem cells, in research, in medicine, or as products....

  3. Cuticle ultrastructure, cuticular lipid composition, and gene expression in hypoxia-stressed Arabidopsis stems and leaves.

    Science.gov (United States)

    Kim, Hyojin; Choi, Dongsu; Suh, Mi Chung

    2017-06-01

    An increased permeability of the cuticle is closely associated with downregulation of genes involved in cuticular lipid synthesis in hypoxia-stressed Arabidopsis and may allow plants to cope with oxygen deficiency. The hydrophobic cuticle layer consisting of cutin polyester and cuticular wax is the first barrier to protect the aerial parts of land plants from environmental stresses. In the present study, we investigated the role of cuticle membrane in Arabidopsis responses to oxygen deficiency. TEM analysis showed that the epidermal cells of hypoxia-treated Arabidopsis stems and leaves possessed a thinner electron-translucent cuticle proper and a more electron-dense cuticular layer. A reduction in epicuticular wax crystal deposition was observed in SEM images of hypoxia-treated Arabidopsis stem compared with normoxic control. Cuticular transpiration was more rapid in hypoxia-stressed leaves than in normoxic control. Total wax and cutin loads decreased by approximately 6-12 and 12-22%, respectively, and the levels of C29 alkanes, secondary alcohols, and ketones, C16:0 ω-hydroxy fatty acids, and C18:2 dicarboxylic acids were also prominently reduced in hypoxia-stressed Arabidopsis leaves and/or stems relative to normoxic control. Genome-wide transcriptome and quantitative RT-PCR analyses revealed that the expression of several genes involved in the biosynthesis and transport of cuticular waxes and cutin monomers were downregulated more than fourfold, but no significant alterations were detected in the transcript levels of fatty acid biosynthetic genes, BCCP2, PDH-E1α, and ENR1 in hypoxia-treated Arabidopsis stems and leaves compared with normoxic control. Taken together, an increased permeability of the cuticle is closely associated with downregulation of genes involved in cuticular lipid synthesis in hypoxia-stressed Arabidopsis. The present study elucidates one of the cuticle-related adaptive responses that may allow plants to cope with low oxygen levels.

  4. Variations of Leaf Cuticular Waxes Among C3 and C4 Gramineae Herbs.

    Science.gov (United States)

    He, Yuji; Gao, Jianhua; Guo, Na; Guo, Yanjun

    2016-11-01

    Modern C4 plants are commonly distributed in hot and dry environments whereas C3 plants predominate in cool and shade areas. At the outmost of plant surface, the deposition and chemical composition of cuticular waxes vary under different environmental conditions. However, whether such variation of cuticular wax is related to the distribution of C3 and C4 under different environmental conditions is still not clear. In this study, leaves of six C3 Gramineae herbs distributed in spring, Roegneria kamoji, Polypogon fugax, Poa annua, Avena fatua, Alopecurus aequalis, and Oplismenus undulatifolius, and four C4 and one C3 Gramineae herbs distributed in summer, Digitaria sanguinalis, Eleusine indica, Setaria viridis, S. plicata, and O. undulatifolius, were sampled and analyzed for cuticular wax. Plates were the main epicuticular wax morphology in both C3 and C4 plants except S. plicata. The plates melted in C4 plants but not in C3 plants. The total cuticular wax amounts in C4 plants were significantly lower than those in C3 plants, except for O. undulatifolius. Primary alcohols were the most abundant compounds in C3 plants, whereas n-alkanes were relatively the most abundant compounds in C4 plants. C29 was the most abundant n-alkane in C3 plants except for O. undulatifolius, whereas the most abundant n-alkane was C31 or C33 in C4 plants. The average chain length (ACL) of n-alkanes was higher in C4 than in C3 plants, whereas the ACL of n-alkanoic acids was higher in C3 than C4 plants. The cluster analysis based on the distribution of n-alkanes clearly distinguished C3 and C4 plants into two groups, except for O. undulatifolius which was grouped with C4 plants. These results suggest that the variations of cuticular waxes among C3 and C4 Gramineae herbs are related to the distribution of C3 and C4 plants under different environmental conditions. © 2016 Wiley-VHCA AG, Zurich, Switzerland.

  5. Chemical composition of the leaf and stem essential oil of Adenophorae Radix

    Science.gov (United States)

    Lan, Weijie; Lin, Shang; Li, Xindan; Zhang, Qing; Qin, Wen

    2017-03-01

    The chemical composition of the essential oil extracted from leaves and stems of Adenophorae Radix was determined for the first time in this study. Twenty-six compounds were identified by gas chromatography coupled to mass spectrometry (GC-MS). n-Hexadecanoic acid (29.14%), 9,12-octadecadienoic acid (Z,Z)- (17.22%), hexadecanoic acid, methyl ester(8.98%), 9-octadecenoic acid, methyl ester, (E)- (7.03%), 9,12-octadecadienoic acid (Z,Z)-, methyl ester (5.93%), phytol (5.50%), and estradiol (4.43%) were measured as the major compounds in stem oil. The leaf essential oil was dominated by n-hexadecanoic acid (50.78%), 9-octadecenoic acid, methyl ester, (E)- (9.04%), phytol (8.47%), d-mannitol (5.81%), 9,12,15-octadecatrienoic acid, methyl ester, (Z,Z,Z)- (4.31%), hexadecanoic acid, methyl ester (2.19%) and 9,12-octadecadienoic acid (Z,Z)-(1.7%). The leaves yield was 0.12% (v/w) and the stems yield showed only 0.073% (v/w). The results might provide reference basis for further exploration of its application value.

  6. Learn About Stem Cells

    Science.gov (United States)

    ... Patient Handbook Stem Cell Glossary Search Toggle Nav Stem Cell Basics Stem cells are the foundation from which ... original cell’s DNA, cytoplasm and cell membrane. About stem cells Stem cells are the foundation of development in ...

  7. Disruption of Retinol (Vitamin A Signaling by Phthalate Esters: SAR and Mechanism Studies.

    Directory of Open Access Journals (Sweden)

    Yanling Chen

    Full Text Available A spectrum of reproductive system anomalies (cryptorchidism, hypospadias, dysgenesis of Wolffian duct-derived tissues and prostate, and reduced sperm production in male rats exposed in utero to phthalate esters (PEs are thought to be caused by PE inhibition of fetal testosterone production. Recently, dibutyl and dipentyl phthalate (DBuP, DPnP were shown to disrupt the retinol signaling pathway (RSP in mouse pluripotent P19 embryonal carcinoma cells in vitro. The RSP regulates the synthesis and cellular levels of retinoic acid (RA, the active metabolite of retinol (vitamin A. In this new study, a total of 26 di- and mono-esters were screened to identify additional phthalate structures that disrupt the RSP and explore their mechanisms of action. The most potent PEs, those causing > 50% inhibition, contained aryl and cycloalkane groups or C4-C6 alkyl ester chains and were the same PEs reported to cause malformations in utero. They shared similar lipid solubility; logP values were between 4 and 6 and, except for PEs with butyl and phenyl groups, were stable for prolonged periods in culture. Mono- and cognate di-esters varied in ability to disrupt the RSP; e.g., DEHP was inactive but its monoester was active while DBuP was active yet its monoester was inactive. DBuP and dibenzyl phthalate both disrupted the synthesis of RA from retinol but not the ability of RA to activate gene transcription. Both PEs also disrupted the RSP in C3H10T1/2 multipotent mesenchymal stem cells. Based on this in vitro study showing that some PEs disrupt retinol signaling and previous in vivo studies that vitamin A/RA deficiency and PEs both cause strikingly similar anomalies in the male rat reproductive system, we propose that PE-mediated inhibition of testosterone and RA synthesis in utero are both causes of malformations in male rat offspring.

  8. The Use of Biobased Surfactant Obtained by Enzymatic Syntheses for Wax Deposition Inhibition and Drag Reduction in Crude Oil Pipelines

    National Research Council Canada - National Science Library

    Zhihua Wang; Xueying Yu; Jiaxu Li; Jigang Wang; Lei Zhang

    2016-01-01

    .... In order to determine the role of drag-reducing surfactant additives in the transportation of crude oils, experiments of wax deposition inhibition and drag reduction of different oil in pipelines...

  9. New approaches for genotyping paraffin wax embedded breast tissue from patients with cancer: the Iowa women’s health study

    OpenAIRE

    Thyagarajan, B; Anderson, K E; Kong, F.; Selk, F R; Lynch, C F; Gross, M.D.

    2005-01-01

    Background: The use of paraffin wax embedded tissue samples as a source of DNA for genotype analysis has been limited because of difficulties in DNA extraction and single nucleotide polymorphism (SNP) analysis.

  10. Evaluation of Physical Properties of Wax Mixtures Obtained From Recycling of Patterns Used in Precision Casting

    Directory of Open Access Journals (Sweden)

    Biernacki R.

    2015-04-01

    Full Text Available The study investigated the properties of selected certified mixtures used to make wax patterns for the production of precision castings for the aerospace industry. In addition, an assessment of the recycled mixtures consisting of certified wax materials recovered during autoclaving was carried out. Hardness was tested via a proposed method based on penetration, creep related deformation, bending strength and linear contraction. The hardness was studied on laboratory specimens and patterns made with the use of injection molding equipment. For these patterns, linear contraction was estimated at variable pressure and for different temperature injection parameters. Deformations connected with creep and resistance were evaluated on cylindrical specimens. Differences in creep resistance in relation to the hardness were observed depending on the type of pattern mixtures. Recycled mixture has a greater resistance and smaller linear contraction than certified mixtures used for making sprue, raisers and other parts of filler system.

  11. Determination of quality attributes in wax jambu fruit using NIRS and PLS.

    Science.gov (United States)

    Viegas, Thayna R; Mata, Ana L M L; Duarte, Márcia M L; Lima, Kássio M G

    2016-01-01

    The aim of this work was to develop an analytical method to predict total anthocyanins content (TAC) and total phenolic compounds (TPC) in intact wax jambu fruit [Syzygium malaccense (L.) Merryl et Perry] using near-infrared spectroscopy (NIRS) and partial least squares (PLS). The estimation accuracy was based on parameters such as root mean square error of prediction (RMSEP), correlation coefficients [calibration (rc) and prediction (rp) set] and ratio of performance to deviation (RPD). TAC, rp = 0.98, RMSEP = 9.0 mg L(-1) and RPD = 5.19 were attained using second derivative pre-treatment. TPC, rp = 0.94, RMSEP = 22.18 (mg gallic acid equivalents (GAE)/100g) and RPD = 3.27 (excellent accuracy) were also obtained using second derivative pre-treatment. These findings suggest that the NIRS and PLS algorithms can be used to determine TCA and TPC in intact wax jambu fruit. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. MEDITERRANEAN FOREST TREE DECLINE IN ITALY: RELATIONSHIPS BETWEEN DROUGHT, POLLUTANTS AND THE WAX STRUCTURE OF LEAVES

    Directory of Open Access Journals (Sweden)

    E. PAOLETTI

    1996-04-01

    Full Text Available After presenting the situation of forest decline in Italy and analyzing the factors that play a contributing role, tbis paper studies the response of the epicuticular wax structures and the stomata in ten broadleaf species and one conifer to fog-like treatments with acids andlor surfactants and to severe water stress. The main results are that wax structure alterations vary in intensity in the different species studied and that the microstructural alterations observed in field conditions cannot be attributed only to severe drought. since sample trccs put through water stress simulations do nol differ significantly from controls. In the artificial surfactant treatment, a positive relationship between structural damage to tbe stomata and transpiration suggests possible synergies between the effects of drought and those of pollutants in inducing stress conditions in Mediterranean vegetation.

  13. Linking shoreline displacement to environmental conditions in the Wax Lake Delta, USA

    Science.gov (United States)

    Geleynse, N.; Hiatt, M. R.; Sangireddy, H.; Passalacqua, P.

    2013-12-01

    The dynamics of river deltas are not well-understood in part because of scarcity of historical data that document the growth or retreat of their channel networks, islands and shorelines. In particular, the mapping of deltaic shorelines is not trivial, however recent developments allow for their extraction from satellite and aerial imagery. Here, we present an analysis of environmental data and Landsat imagery of the Wax Lake Delta, a naturally-developing river delta in the shallow Atchafalaya Basin, Gulf of Mexico, USA. The image-based shoreline corresponds to the hydrodynamic shoreline, that is, the boundary of the subaerial and subaqueous portions of the delta, however, can be related to a morphodynamically-relevant shoreline by application of our method [Geleynse et al., 2012] to bathymetric-topographic data. Moreover, the effect of tides, river floods, wind, and vegetation cover on the extracted shorelines of the Wax Lake Delta can be identified.

  14. Shoreline response to environmental forcings: A case study in the Wax Lake Delta, Gulf of Mexico

    Science.gov (United States)

    Geleynse, Nathanael; Hiatt, Matt; Sangireddy, Harish; Passalacqua, Paola; Mohrig, David

    2013-04-01

    River deltas are well-known landforms within both hydrology and geology. However, both their hydrodynamics and morphodynamics are not well understood, in part because of scarcity of historical data that document the growth or retreat of their channel networks, islands and associated shorelines. Here, we present an analysis of Landsat imagery of the Wax Lake Delta, a young and relatively rapidly prograding delta in the shallow Atchafalaya Basin, Gulf of Mexico. Taking advantage of a recently developed semi-automatic shoreline extraction method [Geleynse et al, 2012], we show how suitably-defined shorelines can be retrieved from satellite imagery. The effect of tides, river floods, storm surges, and vegetation cover on the extracted shoreline of Wax Lake Delta can be quantified as well as the physical relationship between the boundary of the subareal and subaqueous portions of the delta (hydrodynamic shoreline) and the morphodynamic shoreline.

  15. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    Energy Technology Data Exchange (ETDEWEB)

    Amitava Sarkar; James K. Neathery; Burtron H. Davis

    2006-12-31

    A fundamental filtration study was started to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. Slurry-phase FTS in slurry bubble column reactor systems is the preferred mode of operation since the reaction is highly exothermic. Consequently, heavy wax products in one approach may be separated from catalyst particles before being removed from the reactor system. Achieving an efficient wax product separation from iron-based catalysts is one of the most challenging technical problems associated with slurry-phase iron-based FTS and is a key factor for optimizing operating costs. The separation problem is further compounded by attrition of iron catalyst particles and the formation of ultra-fine particles.

  16. 1. Improving the Yield of Biodiesel from Microalgae and Other Lipids. 2. Studies of the Wax Ester Biosynthetic Pathway and Potential Biotechnological Application

    OpenAIRE

    Wahlen, Bradley D.

    2012-01-01

    The production of biofuels and oleochemicals from renewable sources offers an opportunity to reduce our dependence on fossil fuels. The work contained in this dissertation has focused on developing and improving methods for the production of biodiesel from non-traditional feedstocks and understanding biosynthetic pathways that result in the production of oleochemicals and fuels. Pure vegetable oil can account for 70-80% of the total cost of biodiesel production. Many low-cost oils contain ...

  17. Use of Bone Wax During Laparoscopic Renal Ablative Procedures: Optimizing Port Utilization and Reducing Tract-Site Exposure

    OpenAIRE

    Zorn, Kevin C.; Gofrit, Ofer N.; Shalhav, Arieh L.

    2007-01-01

    Purpose: We describe the use of a hemostatic wax sealant during laparoscopic renal ablative procedures to allow airtight transabdominal access of the treatment probe through a standard 5-mm port. Methods: Following Tru-cut biopsy of the renal mass, Bone Wax was used to occlude the external opening of an established 5-mm laparoscopic port. The cryotherapy or radiofrequency treatment probe was then passed through the waxy material and inserted appropriately into the renal lesion while pneumoper...

  18. De novo assembly and characterization of the transcriptome, and development of SSR markers in wax gourd (Benicasa hispida.

    Directory of Open Access Journals (Sweden)

    Biao Jiang

    Full Text Available BACKGROUND: Wax gourd is a widely used vegetable of Cucuribtaceae, and also has important medicinal and health values. However, the genomic resources of wax gourd were scarcity, and only a few nucleotide sequences could be obtained in public databases. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we examined transcriptome in wax gourd. More than 44 million of high quality reads were generated from five different tissues of wax gourd using Illumina paired-end sequencing technology. Approximately 4 Gbp data were generated, and de novo assembled into 65,059 unigenes, with an N50 of 1,132 bp. Based on sequence similarity search with known protein database, 36,070 (55.4% showed significant similarity to known proteins in Nr database, and 24,969 (38.4% had BLAST hits in Swiss-Prot database. Among the annotated unigenes, 14,994 of wax gourd unigenes were assigned to GO term annotation, and 23,977 were found to have COG classifications. In addition, a total of 18,713 unigenes were assigned to 281 KEGG pathways. Furthermore, 6,242 microsatellites (simple sequence repeats were detected as potential molecular markers in wax gourd. Two hundred primer pairs for SSRs were designed for validation of the amplification and polymorphism. The result showed that 170 of the 200 primer pairs were successfully amplified and 49 (28.8% of them exhibited polymorphisms. CONCLUSION/SIGNIFICANCE: Our study enriches the genomic resources of wax gourd and provides powerful information for future studies. The availability of this ample amount of information about the transcriptome and SSRs in wax gourd could serve as valuable basis for studies on the physiology, biochemistry, molecular genetics and molecular breeding of this important vegetable crop.

  19. Effects of D-003 (sugarcane wax acids) on the physical exercise on static bicycle test

    OpenAIRE

    Pérez, Pablo; Illnait, José; Fernández, Lilia; Mesa, Meylis; Fernández, Julio; Gámez, Rafael; Más, Rosa; Gómez, Mainel; Ruiz, Dalmer; Jardines, Yunaisi

    2010-01-01

    Physical inactivity and low maximal exercise oxygen consumption (VO2max) are predictors of mortality and coronary events in adults, respectively. Lowering serum cholesterol and platelet aggregation benefits cardiovascular function in aging persons. D-003, a mixture of sugarcane wax acids, exhibits antiplatelet and cholesterol-lowering effects, and could benefit the performance of middle-aged and older subjects in effort tests. This randomised, double-blinded, placebo-controlled st...

  20. Bees wax polyphenols as suppressor of CC1--induced oxidative stress in rats.

    Science.gov (United States)

    Anilakumar, K R; Krishna, K R S; Chandramohan, G; Khanum, F; Bawa, A S

    2007-01-01

    Bee's wax produced by honeybees is rich in polyphenols. As the polyphenols are thought to protect cell constituents against oxidative damage through scavenging of free radicals, the present work was undertaken to evaluate the effects of polyphenols extracted from bees wax on the oxidative stress induced by carbon tetrachloride (CCl4) in rats. The polyphenols extracted by 80% methanol from bee wax (PBW) were fed to Wistar rats at 100 mg/kg body weight and 200 mg/kg body weight for 14 days in order to study its antioxidative and antihepatotoxic effects against CCl4 (1.5 ml/kg body weight)-induced stress. On 15th day all the rats were sacrificed, blood was collected for serum and organs/tissues were excised for biochemical analysis. The results showed a significant decrease in hepatic antioxidant enzyme activities viz. catalase, glucose-6-phosphate dehydrogenase (G-6-PDH), glutathione peroxidase (GSH-Px), glutathione reductase, superoxide dismutase (SOD) and a significant increase in glutathione S-transferase (GST) and gamma-glutamyl transpeptidase (GGT) by CCl4, probably due to the peroxidative effects. The prophylactic use of PBW at 200 mg/kg level resulted in a significant increase in CCl4-induced reduction in catalase, G-6-PDH, GSSGR and SOD. The hepatic levels of lipid peroxides viz. malondialdehyde, conjugated dienes and lipid hydroperoxides, enhanced by the administration of CCl4 were brought down by the ingestion of PBW at a level of 200 mg/kg. The hepatotoxicity caused by the administration of CCl4 was reduced significantly. Hence, it is concluded that the polyphenols from bees wax exhibit hepatoprotective and antioxidative properties in

  1. A spin cartridge system for DNA extraction from paraffin wax embedded tissues.

    Science.gov (United States)

    Pinto, A P; Villa, L L

    1998-02-01

    A simple and efficient method of DNA extraction from paraffin wax embedded tissues using a spin cartridge system is described. Such DNAs were shown to be suitable for amplification by the polymerase chain reaction, which targeted two human papillomavirus genes and one globin fragment giving rise to products of 450, 150, and 110 base pairs, respectively. Different human tissues, stored for up to 20 years, were successfully amplified, demonstrating the usefulness of this very simple procedure for retrospective studies.

  2. A spin cartridge system for DNA extraction from paraffin wax embedded tissues.

    OpenAIRE

    Pinto,A.P.; L.L. Villa

    1998-01-01

    A simple and efficient method of DNA extraction from paraffin wax embedded tissues using a spin cartridge system is described. Such DNAs were shown to be suitable for amplification by the polymerase chain reaction, which targeted two human papillomavirus genes and one globin fragment giving rise to products of 450, 150, and 110 base pairs, respectively. Different human tissues, stored for up to 20 years, were successfully amplified, demonstrating the usefulness of this very simple procedure f...

  3. Effect of expanded graphite on the phase change materials of high density polyethylene/wax blends

    Energy Technology Data Exchange (ETDEWEB)

    AlMaadeed, M.A., E-mail: m.alali@qu.edu.qa [Center for Advanced Materials, Qatar University, 2713 Doha (Qatar); Labidi, Sami [Center for Advanced Materials, Qatar University, 2713 Doha (Qatar); Krupa, Igor [QAPCO Polymer Chair, Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha (Qatar); Karkri, Mustapha [Université Paris-Est CERTES, 61 avenue du Général de Gaulle, 94010 Créteil (France)

    2015-01-20

    Highlights: • Expanded graphite (EG) and low melting point (42.3 °C) wax were added to HDPE to form phase change material. • EG was well dispersed in the composites and did not affect the melting or crystallization of the HDPE matrix. • EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. • The addition of a relatively small quantity of EG enhances the heat conduction in the composite. • HDPE/40% RT42 that contained up to 15% EG demonstrated excellent mechanical and thermal properties and can be used as PCM. - Abstract: Phase change materials fabricated from high density polyethylene (HDPE) blended with 40 or 50 wt% commercial wax (melting point of 43.08 °C) and up to 15 wt% expanded graphite (EG) were studied. Techniques including scanning electron microscope (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and an experimental device to measure diffusivity and conductivity (DICO) were used to determine the microstructural, mechanical and thermal properties of the composites. The composites possessed good mechanical properties. Additionally, no leaching was observed during material processing or characterization. Although the Young’s modulus increased with the addition of EG, no significant changes in tensile strength were detected. The maximum Young’s modulus achieved was 650 MPa for the HDPE/40% wax composite with 15 wt% EG. The EG was well dispersed within the composites and did not affect the melting or crystallization of the HDPE matrix. The incorporation of EG increased the thermal stability of the composites by reducing chain mobility and inhibiting degradation. The intensification of thermal conductivity occurred with increasing fractions of EG, which was attributed to the high thermal conductivity of graphite. The maximum quantity of heat stored by latent heat was found for the HDPE/40% wax composite with EG. The addition of a relatively small quantity

  4. Triterpenoid profile of fruit and leaf cuticular waxes of edible honeysuckle Lonicera caerulea var. kamtschatica

    OpenAIRE

    Rafał Becker; Cezary Pączkowski; Anna Szakiel

    2017-01-01

    Edible honeysuckle (honeyberry) Lonicera caerulea is becoming popular as a novel berry crop with several useful features such as early fruit ripening and exceptional hardiness, particularly resistance to pests and diseases as well as severe frosts in winter and droughts in summer. The triterpenoid profile of fruit and leaf cuticular waxes of edible honeysuckle (a Russian cultivar Chernichka) was analyzed by GC-MS. The major compounds identified were the tetracyclic triterpenoids campesterol, ...

  5. Model predictions for the WAXS signals of healthy and malignant breast duct biopsies

    Science.gov (United States)

    LeClair, R. J.

    2014-03-01

    A wide-angle x-ray scatter (WAXS) measurement could potentially be used to determine whether a biopsy of a breast duct is healthy or malignant. A ductal carcinoma in situ (DCIS) occurs when the epithelial cells lining the wall start to replicate and invade the duct interior. Since cells are composed mainly of water a WAXS signal of DCIS could contain a larger component due to water. A model approximates that a breast duct biopsy consists of connective tissue (c.t.) and cells. For a 2 mm diameter 3.81 mm thick healthy duct biopsy, the volumes in cubic mm are 11.56 c.t. and 0.41 cells whereas 6.64 c.t. and 5.33 cells for DCIS. The differential linear scattering coefficients (μs) for both types of biopsies were calculated using the sum vc.t.μsc.t. + vcellμscell where v denotes fractional volume. The cell was assumed to be composed of water, lipids (fat), and other atoms associated with RNA, DNA, proteins, and carbohydrates. The μscell was calculated using the sum 0.771μswater + 0.023μsfat + 0.206μsother. The μs of c.t., water, and fat were available from literature whereas the independent atomic model approximation was used to calculate values for μsother. A WAXS model provided predictions of the number of 6 degree scattered photons Ns for incident 50 kV beams on healthy and malignant ducts. The sum of Ns between 31.5 biopsies. Using Poisson statistics, two Gaussian distributions, and a descision threshold set at their intersection, the false positive and false negative probabilities were 4.7% and 5.0%. This work suggests that DCIS could potentially be diagnosed via energy dispersive WAXS measurements.

  6. Effects of Aridity and Vegetation on Plant-wax δD in Modern Lake Sediments

    Science.gov (United States)

    Polissar, P. J.; Freeman, K. H.

    2010-12-01

    Plant waxes are preserved over geologic timescales, and are found in diverse ancient sediments and soils. Observations that these molecules have hydrogen isotopic signatures that can be systematically related to that of modern precipitation have fueled aspirations to reconstruct ancient precipitation δD values. However, molecular isotopic signatures also reflect climate and plant physiological factors, and until better understood, these limit our ability to quantitatively interpret sedimentary lipid records. To advance our understanding of the influence of both ecosystem flora and climate (especially aridity) at the field scale, we analyzed the deuterium content of plant-waxes from sediments in 28 modern lakes located in watersheds which receive precipitation with a wide range of δD values, and are characterized by distinct vegetation types and regional climates. We found that the apparent isotopic fractionation (ɛa) between plant-wax n-alkanes and precipitation differs with watershed ecosystem type and structure, and decreases with increasing regional aridity as measured by enrichment of 2H and 18O associated with evaporation of lake waters. The most negative ɛa values represent signatures least affected by aridity; these values were: -125 ± 5 ‰ for tropical evergreen and dry forests, -130 ‰ for a temperate broadleaf forest, -120 ± 9 ‰ for the high-altitude tropical páramo (herbs, shrubs and grasses), and -98 ± 6 ‰ for North American montane gymnosperm forests. Minimum ɛa values reflect ecosystem-dependent differences in leaf water enrichment and soil evaporation. Slopes of lipid/lakewater isotopic enrichments differ slightly with ecosystem structure (i.e. open shrublands vs. forests) and overall are quite small (slopes = 0 to 2), indicating low sensitivity of lipid δD variations to aridity compared with coexisting lake waters. This finding provides an approach for reconstructing ancient precipitation signatures based on plant-wax

  7. Dimensional Precision Research of Wax Molding Rapid Prototyping based on Droplet Injection

    Science.gov (United States)

    Mingji, Huang; Geng, Wu; yan, Shan

    2017-11-01

    The traditional casting process is complex, the mold is essential products, mold quality directly affect the quality of the product. With the method of rapid prototyping 3D printing to produce mold prototype. The utility wax model has the advantages of high speed, low cost and complex structure. Using the orthogonal experiment as the main method, analysis each factors of size precision. The purpose is to obtain the optimal process parameters, to improve the dimensional accuracy of production based on droplet injection molding.

  8. Preparation and evaluation of waxes/fat microspheres loaded with lithium carbonate for controlled release

    OpenAIRE

    Gowda D.; Shivakumar H

    2007-01-01

    To minimize the unwanted toxic effects of anti maniac drug lithium carbonate by kinetic control of drug release, it was entrapped into gastro resistant, biodegradable, waxes and fat such as beeswax, cetostearyl alcohol, spermaceti and cetylalcohol microspheres using meltable emulsified dispersion cooling induced solidification technique utilizing a wetting agent. Solid, discrete, reproducible free flowing microspheres were obtained. The yield of the microspheres was up to 90.0%. More t...

  9. Mutagenic activity of phthalate esters in bacterial liquid suspension assays.

    OpenAIRE

    Seed, J L

    1982-01-01

    The mutagenic activities of several phthalate esters have been evaluated in an 8-azaguanine resistance assay in Salmonella typhimurium. Three phthalate esters were found to be mutagenic: dimethyl phthalate, diethyl phthalate and di-n-butyl phthalate. A number of other phthalate esters were not found to be mutagenic, including di(2-ethylhexyl) phthalate, di-n-octyl phthalate, diallyl phthalate, diisobutyl phthalate and diisodecyl phthalate. A metabolite of di(2-ethylhexyl) phthalate, 2-ethylhe...

  10. Parameters affecting ethyl ester production by Saccharomyces cerevisiae during fermentation.

    Science.gov (United States)

    Saerens, S M G; Delvaux, F; Verstrepen, K J; Van Dijck, P; Thevelein, J M; Delvaux, F R

    2008-01-01

    Volatile esters are responsible for the fruity character of fermented beverages and thus constitute a vital group of aromatic compounds in beer and wine. Many fermentation parameters are known to affect volatile ester production. In order to obtain insight into the production of ethyl esters during fermentation, we investigated the influence of several fermentation variables. A higher level of unsaturated fatty acids in the fermentation medium resulted in a general decrease in ethyl ester production. On the other hand, a higher fermentation temperature resulted in greater ethyl octanoate and decanoate production, while a higher carbon or nitrogen content of the fermentation medium resulted in only moderate changes in ethyl ester production. Analysis of the expression of the ethyl ester biosynthesis genes EEB1 and EHT1 after addition of medium-chain fatty acid precursors suggested that the expression level is not the limiting factor for ethyl ester production, as opposed to acetate ester production. Together with the previous demonstration that provision of medium-chain fatty acids, which are the substrates for ethyl ester formation, to the fermentation medium causes a strong increase in the formation of the corresponding ethyl esters, this result further supports the hypothesis that precursor availability has an important role in ethyl ester production. We concluded that, at least in our fermentation conditions and with our yeast strain, the fatty acid precursor level rather than the activity of the biosynthetic enzymes is the major limiting factor for ethyl ester production. The expression level and activity of the fatty acid biosynthetic enzymes therefore appear to be prime targets for flavor modification by alteration of process parameters or through strain selection.

  11. Alkanes in flower surface waxes of Momordica cochinchinensis influence attraction to Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae).

    Science.gov (United States)

    Mukherjee, A; Sarkar, N; Barik, A

    2013-08-01

    Extraction, thin-layer chromatography, and gas chromatography-mass spectrophotometry analyses revealed 15 alkanes representing 97.14% of the total alkanes in the surface waxes of Momordica cochinchinensis Spreng flowers. Nonacosane was the prevailing alkane followed by hexatriacontane, nonadecane, heptacosane, and hentriacontane, accounting for 39.08%, 24.24%, 13.52%, 6.32%, and 5.12%, respectively. The alkanes from flower surface waxes followed by a synthetic mixture of alkanes mimicking alkanes of flower surface waxes elicited attraction of the female insect, Aulacophora foveicollis Lucas (Coleoptera: Chrysomelidae) between 2 and 10-μg/mL concentrations in a Y-shaped glass tube olfactometer bioassay under laboratory conditions. Synthetic nonadecane from 178.28-891.37 ng, heptacosane from 118.14-590.72 ng, and nonacosane at 784.73 ng showed attraction of the insect. A synthetic mixture of 534.82 ng nonadecane, 354.43 ng heptacosane, and 2,354.18 ng nonacosane elicited highest attraction of A. foveicollis.

  12. Control of the wax moth Galleria mellonella L. (Lepidoptera: Pyralidae by the male sterile technique (MST

    Directory of Open Access Journals (Sweden)

    Jafari Reza

    2010-01-01

    Full Text Available In this study we examined the control of wax moth using the male sterile technique (MST with gamma-rays. To determine the safe and effective dosage of gamma-rays capable of sterilizing male pupae of the wax moth, male pupae were exposed to increasing single doses of gamma-rays (250, 300, 350 and 400 Gy. The release ratio of sterile to normal males was also studied in a similar experiment. Treatments included sterile males, normal males and virgin females at the following ratios: 1:1:1, 2:1:1, 3:1:1, 4:1:1 and 5:1:1. Possible parthenogenetic reproduction of this pest was also examined. The results showed that 350 Gy was the most effective dose capable of sterilizing the male pupae of the wax moth. The best release ratio was established at four sterile males, one normal male for each normal female (4:1:1. Also females were incapable of producing offspring without males.

  13. Application of carnauba-based wax maintains postharvest quality of 'Ortanique' tangor

    Directory of Open Access Journals (Sweden)

    Francisca Ligia de Castro Machado

    2012-06-01

    Full Text Available This study aimed at evaluating compositional changes in the quality of 'Ortanique' tangor after coating with the carnauba-based waxes Aruá Tropical® or Star Light®. The storage conditions studied simulated those of local marketing (22 ± 2 °C, 60 ± 5% RH. Non-destructive analysis, mass loss, peel color, and sensory evaluation, were performed upon coating and every three days up to the fifteenth day of storage. Destructive analysis, peel moisture content, chlorophyll of the peel, pulp color, juice content, soluble solids (SS, titratable acidity (TA, pH, and soluble solids to titratable acidity ratio, were performed upon coating and every four days up to the sixteenth day of storage. The assay was conducted using an entirely randomized design, with three replications (destructive analyses or ten replications (non-destructive analyses, in a split plot scheme. Wax-coating, especially Aruá Tropical®, maintained fruit freshness by reducing mass loss and peel dehydration and retaining green color. Peel moisture content, chlorophyll content, and juice content had lower rates in the wax coated fruits. Puncture force, soluble solids, titratable acidity, pH, and soluble solids to titratable acidity ratio varied vary little over the course of storage. Sensory evaluation showed that the application of Aruá Tropical keeps 'Ortanique' tangor fresher for 6 days longer for commercialization.

  14. Micro- and nanoscale structures of mesiodens dentin: Combined study of FTIR and SAXS/WAXS techniques.

    Science.gov (United States)

    Akgun, Ozlem Marti; Bayari, Sevgi Haman; Ide, Semra; Polat, Günseli Guven; Kalkhoran, Ilghar Orujalipoor

    2015-01-01

    A mesiodens is the most common type of supernumerary tooth present in conjunction to normal dentition. A mesiodens may commonly occur in the central region of the upper or lower jaw. A mesiodens is different from normal teeth in terms of structure and shape. The aim of this study is to evaluate the micro- and nanoscale structural properties of mesiodens dentin by combined small- and wide-angle X-ray scattering (SAXS/WAXS) and Fourier transform infrared (FTIR) spectroscopy. Five freshly extracted, noncarious mesiodens and five normal dentin disks prepared from human incisor teeth were compared. Using FTIR, the phosphate-to-amide I, carbonate-to-phosphate, and carbonate-to-amide I band area ratios and the crystallinity index were quantified. SAXS/WAXS were used to study the nanostructure of mesiodens. An increase in the mineral content in the mesiodens dentin with respect to the normal group was found. Crystallinity was also significantly increased and the protein content decreased in the mesiodens dentin compared with that of normal dentin. SAXS/WAXS results revealed that mesiodens dentin has a more calcified tissue. Further, SAXS analysis revealed a nonuniform distribution of dentin fibrils in mesiodens. © 2014 Wiley Periodicals, Inc.

  15. Phase Change Material Trade Study: A Comparison Between Wax and Water for Manned Spacecraft

    Science.gov (United States)

    Quinn, Gregory; Hodgson, Ed; Stephan, Ryan A,

    2011-01-01

    Phase change material heat sinks have been recognized as an important tool in optimizing thermal control systems for space exploration vehicles and habitats that must deal with widely varying thermal loads and environments. In order to better focus technology investment in this arena, NASA has supported a trade study with the objective of identifying where the best potential pay-off can be found among identified aqueous and paraffin wax phase change materials and phase change material heat sink design approaches. The study used a representative exploration mission with well understood parameters to support the trade. Additional sensitivity studies were performed to ensure the applicability of study results across varying systems and destinations. Results from the study indicate that replacing a wax PCM heat sink with a water ice PCM heat sink has the potential to decrease the equivalent system mass of the mission s vehicle through a combination of a smaller heat sink and a slight 5% increase in radiator size or the addition of a lightweight heat pump. An evaluation of existing and emerging PCM heat sink technologies indicates that further mass savings should be achievable through continued development of those technologies. The largest mass savings may be realized by eliminating the melting and freezing pressure of wax and water, respectively.

  16. Safety and efficacy of bone wax in patients on oral anticoagulant therapy.

    Science.gov (United States)

    Krasny, Marta; Krasny, Kornel; Fiedor, Piotr

    2014-01-01

    Cardiovascular conditions, apart from neoplastic diseases, remain the major cause of death in developed countries; therefore, the number of patients receiving oral anticoagulants is constantly increasing. Anticoagulant therapy considerably reduced mortality in patients with history of myocardial infarction among others. Although many interventions may be performed without withdrawal of the anticoagulant and tooth extraction was qualified as a procedure of low hemorrhage risk, a majority of dentists refer the patient to a cardiologist several days before the elective tooth extraction to withdraw anticoagulants. The aim of the study was to evaluate the efficacy and safety of bone wax used to stop bleeding after dental procedures in a group of patients on chronic anticoagulant therapy and find an answer to a question, whether it is justified to temporarily withdraw anticoagulants for this type of procedures. The study involved 176 patients on chronic anticoagulant therapy undergoing tooth extraction (154 subjects) or surgical extraction of a retained tooth (48 subjects). After the procedure, in each case the alveolus was filled with bone wax to stop bleeding. In all patients involved in the study bleeding from the alveolus was successfully stopped during the procedure. None of the subjects reported increased bleeding from the operational site after coming back home. Bone wax is a good, efficient, and safe material to block bleeding from the alveolus following tooth extractions, also in patients on chronic anticoagulant therapy. The study demonstrated that withdrawal or adjustment of anticoagulant therapy is not necessary before an elective tooth extraction.

  17. Enhanced Thermo-Optical Switching of Paraffin-Wax Composite Spots under Laser Heating.

    Science.gov (United States)

    Said, Asmaa; Salah, Abeer; Fattah, Gamal Abdel

    2017-05-12

    Thermo-optical switches are of particular significance in communications networks where increasingly high switching speeds are required. Phase change materials (PCMs), in particular those based on paraffin wax, provide wealth of exciting applications with unusual thermally-induced switching properties, only limited by paraffin's rather low thermal conductivity. In this paper, the use of different carbon fillers as thermal conductivity enhancers for paraffin has been investigated, and a novel structure based on spot of paraffin wax as a thermo-optic switch is presented. Thermo-optical switching parameters are enhanced with the addition of graphite and graphene, due to the extreme thermal conductivity of the carbon fillers. Differential Scanning Calorimetry (DSC) and Scanning electron microscope (SEM) are performed on paraffin wax composites, and specific heat capacities are calculated based on DSC measurements. Thermo-optical switching based on transmission is measured as a function of the host concentration under conventional electric heating and laser heating of paraffin-carbon fillers composites. Further enhancements in thermo-optical switching parameters are studied under Nd:YAG laser heating. This novel structure can be used in future networks with huge bandwidth requirements and electric noise free remote aerial laser switching applications.

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

    Science.gov (United States)

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

    2010-01-01

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

  19. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    Energy Technology Data Exchange (ETDEWEB)

    James K. Neathery; Gary Jacobs; Amitava Sarkar; Adam Crawford; Burtron H. Davis

    2006-09-30

    In the previous reporting period, modifications were completed for integrating a continuous wax filtration system for a 4 liter slurry bubble column reactor. During the current reporting period, a shakedown of the system was completed. Several problems were encountered with the progressive cavity pump used to circulate the wax/catalyst slurry though the cross-flow filter element and reactor. During the activation of the catalyst with elevated temperature (> 270 C) the elastomer pump stator released sulfur thereby totally deactivating the iron-based catalyst. Difficulties in maintaining an acceptable leak rate from the pump seal and stator housing were also encountered. Consequently, the system leak rate exceeded the expected production rate of wax; therefore, no online filtration could be accomplished. Work continued regarding the characterization of ultra-fine catalyst structures. The effect of carbidation on the morphology of iron hydroxide oxide particles was the focus of the study during this reporting period. Oxidation of Fe (II) sulfate results in predominantly {gamma}-FeOOH particles which have a rod-shaped (nano-needles) crystalline structure. Carbidation of the prepared {gamma}-FeOOH with CO at atmospheric pressure produced iron carbides with spherical layered structure. HRTEM and EDS analysis revealed that carbidation of {gamma}-FeOOH particles changes the initial nano-needles morphology and generates ultrafine carbide particles with irregular spherical shape.

  20. Anti-adhesive effects of plant wax coverage on insect attachment.

    Science.gov (United States)

    Gorb, Elena V; Gorb, Stanislav N

    2017-11-09

    The long period of reciprocal antagonistic coevolution between some insect and plant species has led to the development of plant surface attributes that reduce insect attachment. These features serve as a defence against herbivores, sap-sucking insects and nectar robbers, contribute to a temporary capture of insect pollinators, and prevent the escape of insects from traps of carnivorous plants. This review summarises the literature on attachment-mediated insect-plant interactions. A short introduction to attachment systems of insects is presented and the effect of three-dimensional epicuticular waxes on insect attachment is illustrated by many examples. Special attention is given to the mechanisms of the anti-attachment properties of plant wax structures (the roughness hypothesis, the contamination hypothesis, the fluid-adsorption hypothesis, and the wax-dissolving hypothesis) and their ecological implications. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  1. Metabolic engineering of plant oils and waxes for use as industrial feedstocks.

    Science.gov (United States)

    Vanhercke, Thomas; Wood, Craig C; Stymne, Sten; Singh, Surinder P; Green, Allan G

    2013-02-01

    Society has come to rely heavily on mineral oil for both energy and petrochemical needs. Plant lipids are uniquely suited to serve as a renewable source of high-value fatty acids for use as chemical feedstocks and as a substitute for current petrochemicals. Despite the broad variety of acyl structures encountered in nature and the cloning of many genes involved in their biosynthesis, attempts at engineering economic levels of specialty industrial fatty acids in major oilseed crops have so far met with only limited success. Much of the progress has been hampered by an incomplete knowledge of the fatty acid biosynthesis and accumulation pathways. This review covers new insights based on metabolic flux and reverse engineering studies that have changed our view of plant oil synthesis from a mostly linear process to instead an intricate network with acyl fluxes differing between plant species. These insights are leading to new strategies for high-level production of industrial fatty acids and waxes. Furthermore, progress in increasing the levels of oil and wax structures in storage and vegetative tissues has the potential to yield novel lipid production platforms. The challenge and opportunity for the next decade will be to marry these technologies when engineering current and new crops for the sustainable production of oil and wax feedstocks. © 2012 CSIRO Plant Biotechnology Journal © 2012 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  2. The resistance of surfaces treated with oils and waxes to the action of dry heat

    Directory of Open Access Journals (Sweden)

    Jaić Milan

    2009-01-01

    Full Text Available Surface treatment of wood can be done with different coatings, and the choice of the appropriate system of processing depends on several factors, such as technological, aesthetic, economic and ecological. Raising awareness of the need to preserve the living and working environment has had a crucial impact on the increase in the use of natural materials for surface treatment of wood - oil and wax. The application of oils and waxes allows surface treated wood to keep the natural look, while protecting it from different influences, which can cause degradation and deterioration of the final product. The paper presents the results of testing the resistance of beech surface (Fagus silvatica L. processed with linseed oil and beeswax to the action of dry heat. In order to compare the quality of surface treated with oil and/or wax, beech wood treated with 2K-polyurethane coating is taken as a reference of surface treatment of wood. Surfaces treated with beeswax are less resistant to dry heat than those treated with linseed oil, and both showed significantly less resistance than surface treated with 2K-polyurethane coating.

  3. Separation of boron from borated paraffin wax by pyrohydrolysis and alkali extraction methods and its determination using ion chromatography.

    Science.gov (United States)

    Raut, Vaibhavi Vishwajeet; Jeyakumar, Subbiah; Shah, Dipti Jayesh; Thakur, Uday Kumar; Tomar, Bhupendra Singh; Ramakumar, Karanam Lakshminarayana

    2015-01-01

    A method based on the pyrohydrolysis extraction of boron and its quantification with ion chromatography was proposed for paraffin waxes borated with H3BO3 and B4C. The optimum pyrohydrolysis conditions were identified. Wax samples were mixed with U3O8, which prevents the sample from flare up, and also accelerates the extraction of boron. Pyrohydrolysis was carried out with moist O2 at 950°C for 60 and 90 min for wax with H3BO3 and wax with B4C, respectively. Two simple methods of separation based on alkali extraction and melting wax in alkali were also developed exclusively for wax with H3BO3. In all the separations, the recovery of B was above 98%. During IC separation, B was separated as boron-mannitol anion complex. Linear calibration was obtained it between 0.1 and 50 ppm of B, and LOD was calculated as 5 ppb (S/N = 3). The reproducibility was better than 5% (RSD).

  4. Evaluation of methods for wax determination in crude oil; Avaliacao de metodos de determinacao de parafinas em petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Julio Cesar M.; Silva, Maria do Socorro A.J. da; Vasconcellos, Rosa C.U. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Tamanqueira, Juliana B. [Fundacao Gorceix, Ouro Preto, MG (Brazil)

    2008-07-01

    Determining the wax content of crude oil is of great importance for petroleum industry, especially for production, storage and transportation of crude oils. Many different methodologies of wax determining are available in the technical literature. However, the selection of the most suitable method must be in accordance with the aim of the analysis and observing the specificities of each technique. The purpose of this work was to determine the performance of different techniques of wax determining applied to characterization of precipitation properties of waxy compounds in crude oils. Twelve samples of crude oils proceeding from the main Brazilian oil producing sedimentary basins were selected for this study. These samples were analyzed by three important analytical techniques of wax determining: precipitation by cooled solvent; liquid chromatography with precipitation by cooled solvent; and liquid chromatography followed by gas chromatography. Differential scanning calorimetry data related to the wax crystallization in these oils were used as parameters of validation. The results obtained in this study indicate that the liquid chromatography followed by gas chromatography method has the best performance for wax determining in crude oils. (author)

  5. Estereótipos e mulheres na cultura marroquina

    OpenAIRE

    Sadiqi,Fatima

    2008-01-01

    Estereótipos sobre as mulheres no Marrocos podem ser caracterizados como crenças culturais incompletas e inexatas mantidas por algumas pessoas e que se encontram inscritos em expressões lingüísticas ou em discursos subliminares. A cultura popular marroquina emprega representações poderosas para transmitir e sustentar tais estereótipos. Embora existam alguns estereótipos positivos, a maioria dos estereótipos sobre as mulheres no Marrocos é negativa e reflete ditames patriarcais subliminares qu...

  6. A novel thermooxidatively stable poly(ester-imide-benzoxazole)

    Energy Technology Data Exchange (ETDEWEB)

    Sundar, R.A.; Mathias, L.J. [Univ. of Sothern Mississippi, Hattiesburg, MS (United States)

    1993-12-31

    A poly(ester-amide-imide) was synthesized by the low temperature solution polycondensation of 4-amino-5-hydroxy-N,4{prime}-hydroxyphenyl phthalimide with isophthaloyl chloride. Subsequent thermal cyclodehydration of the poly(ester-amide-imide) at 320{degrees}C in vacuum afforded the poly(ester-imide-benzoxazole). This polymer was only soluble in sulfuric acid. FTIR and NMR spectra confirmed structure. The poly(ester-imide-benzoxazole) had no detectable thermal transitions up to 500{degrees}C in nitrogen, and was reasonably stable in air and nitrogen, with weight retentions of 95% at 500{degrees}C.

  7. Tandem transformation of glycerol to esters.

    Science.gov (United States)

    Sotenko, Maria V; Rebroš, Martin; Sans, Victor S; Loponov, Konstantin N; Davidson, Matthew G; Stephens, Gill; Lapkin, Alexei A

    2012-12-31

    Tandem transformation of glycerol via microbial fermentation and enzymatic esterification is presented. The reaction can be performed with purified waste glycerol from biodiesel production in a continuous mode, combining continuous fermentation with membrane-supported enzymatic esterification. Continuous anaerobic fermentation was optimized resulting in the productivity of 2.4 g L⁻¹ h⁻¹ of 1,3-propanediol. Biphasic esterification of 1,3-propanediol was optimized to achieve ester yield of up to 75%. A hollow fibre membrane contactor with immobilized Rhizomucor miehei lipase was demonstrated for the continuous tandem fermentation-esterification process. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Effects of high-melting methyl esters on crystallization properties of fatty acid methyl ester mixtures

    Science.gov (United States)

    Biodiesel is a renewable alternative diesel fuel made from vegetable oils and animal fats. The most common form of biodiesel in the United States are fatty acid methyl esters (FAME) from soybean, canola, and used cooking oils, waste greases, and tallow. Cold flow properties of biodiesel depend on th...

  9. Palladium-catalysed arylation of acetoacetate esters to yield 2-arylacetic acid esters

    CSIR Research Space (South Africa)

    Zeevaart, JG

    2004-05-24

    Full Text Available The coupling reaction between ethyl acetoacetate and a number of aryl halides in the presence of palladium acetate, a bulky and electron rich phosphine and K3PO4 is described. The arylated acetoacetate ester is de-acylated under the reaction...

  10. Half esters and coating compositions comprising reactions products of half esters and polyepoxides

    NARCIS (Netherlands)

    Blaauw, R.; Mulder, W.J.; Koelewijn, R.; Boswinkel, G.

    2006-01-01

    The present invention relates to half esters based on dicarboxylic acid derivatives and dimer fatty diols, wherein the dimer fatty dio ls are based on dimerised and/or trimerised and/or oligomerised unsaturated fatty acids. The present invention further relates to resin compositions based on the

  11. How Well Does BODIPY-Cholesteryl Ester Mimic Unlabeled Cholesteryl Esters in High Density Lipoprotein Particles?

    DEFF Research Database (Denmark)

    Karilainen, Topi; Vuorela, Timo; Vattulainen, Ilpo

    2015-01-01

    We compare the behavior of unlabeled and BODIPY-labeled cholesteryl ester (CE) in high density lipoprotein by atomistic molecular dynamics simulations. We find through replica exchange umbrella sampling and unbiased molecular dynamics simulations that BODIPY labeling has no significant effect...

  12. Leaf Wax δ13C Varies with Elevation in the Peruvian Andes and Western Amazonia

    Science.gov (United States)

    Wu, M. S.; Feakins, S. J.; Ponton, C.; Peters, T.; West, A. J.; Galy, V.; Bentley, L. P.; Salinas, N.; Shenkin, A.; Martin, R.; Asner, G. P.; Malhi, Y.

    2015-12-01

    Plant leaf wax carbon isotopic composition (δ13Cwax) reflects the net isotopic effects associated with diffusion into the leaf, fixation of carbon by Rubisco and biosynthesis of individual leaf wax biochemicals. As declining pCO2 with elevation affects the first two fractionations, we expect to find an isotopic gradient in δ13Cwax, if the fractionation of leaf wax biosynthesis is constant. To test this, we report δ13Cwax values from 500 samples of leaves collected by tree-climbers from the upper canopy from 9 forest-inventory plots spanning a 3.5km elevation transect in the Peruvian Andes and western Amazonia during the CHAMBASA field campaign. These samples provide a unique opportunity to study the relationship between δ13Cwax and pCO2 in diverse species across this remote tropical montane forest and lowland rainforest. The very wet climate throughout (2-5 m rainfall per year) minimizes fractionation effects due to stomatal restrictions (i.e. water use efficiency) that may be an important factor elsewhere. Preliminary results show δ13Cwax values on average increase with elevation by ~1.5‰/km, a trend consistent with bulk plant δ13C in previous studies. The mean epsilon between bulk and C29 n-alkane is -7.3±2.2‰. Inter-sample differences are large on the order of 10‰. Shaded leaves and understory leaves are found to be depleted relative to sunlit leaves, presumably due to a lower photosynthetic rate and use of respired CO2 in the understory. C29 n-alkanes are on average ~2.5‰ more depleted than C30 n-alkanoic acids, indicating fractionation during selective decarboxylation. We further compare results from plants with soil and river sediments to provide insights into how leaf wax signals are archived in soils and exported from the landscape. We find a ~1.4‰/km gradient in forest soils similar to plants. We observe a ~2‰ offset between C29 n-alkane in plant leaves and in soils across the elevation profile, which is likely a signal of degradation

  13. Partial least squares regression calibration for determining wax content in processed flax fiber by near-infrared spectroscopy.

    Science.gov (United States)

    Sohn, Miryeong; Himmelsbach, David S; Morrison, W Herbert; Akin, Danny E; Barton, Franklin E

    2006-04-01

    The quality of flax fiber in the textile industry is closely related to the wax content remaining on the fiber after the cleaning process. Extraction by organic solvents, which is currently used for determining wax content, is very time consuming and produces chemical waste. In this study, near-infrared (NIR) spectroscopy was used as a rapid analytical technique to develop models for wax content associated with flax fiber. Calibration samples (n=11) were prepared by manually mixing dewaxed fiber and isolated wax to provide a range of wax content from 0 to 5%. A total of fourteen flax fiber samples obtained after a cleaning process were used for prediction. Principal component analysis demonstrated that one principal component is enough to separate the flax fibers by their wax content. The most highly correlated wavelengths were 2312, 2352, 1732, and 1766 nm, in order of significance. Partial least squares models were developed with various chemometric preprocessing approaches to obtain the best model performance. Two models, one using the entire region (1100-2498 nm) and the other using the selected wavelengths, were developed and the accuracies compared. For the model using the entire region, the correlation coefficient (R2) between actual and predicted values was 0.996 and the standard error of prediction (RMSEP) was 0.289%. For the selected-wavelengths model, the R2 was 0.997 and RMSEP was 0.272%. The results suggested that NIR spectroscopy can be used to determine wax content in very clean flax fiber and that development of a low-cost device, using few wavelengths, should be possible.

  14. Alternative Production of Fatty Acid Methyl Esters from Triglycerides ...

    African Journals Online (AJOL)

    The catalysts activity was tested in thermocatalytic cracking of triglyceride; a direct conversion process for fatty acid methyl esters (biodiesel). The SZ1 not only exhibited higher conversion of triglycerides but higher fatty acid methyl esters (FAMEs) yields of approximately 59% after 3h as compared to SZ2 (32%). In addition ...

  15. Comparative analysis of rubber seed methyl ester with other methyl ...

    African Journals Online (AJOL)

    The important properties of biodiesel such as specific gravity, flash point, cloud point and pour point were determined and compared with that of diesel. Other properties such as kinematic viscosity sulphur content, Aniline point and Acid value of rubber seed methyl ester were deduced and compared with other methyl esters.

  16. Page 1 HYDROLYTIC REACTIONS OF ESTERS AND AMIDES OF ...

    Indian Academy of Sciences (India)

    1962-06-09

    (Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore-12, India). Received June 9, 1962. (Communicated by Prof. M. R. A. Rao, F.A.Sc.) ABSTRACT. The hydrolytic reactions of esters and amides of thiosulphurous acid are investigated in a homogeneous medium. The esters are hydrolysed.

  17. Determination of Phthalate Esters in the Aquatic Environment ...

    African Journals Online (AJOL)

    The use of solid phase extraction and capillary GLC provides the basis for selective determination of phthalate ester plasticizers in rivers and marine water samples. Of the several solvent ratios (methanol in dichloromethane) that were tried for selective elution of phthalate esters from the C18 solid phase glass catridge, the ...

  18. Effect of Sucrose Esters on the Physicochemical Properties of Wheat ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of sucrose esters on the physicochemical properties of wheat starch. Methods: Sucrose ester was mixed with wheat starch extracted from normal soft wheat cultivars and heated. Change in starch properties arising from the interaction between were assessed for starch blue value, viscosity, ...

  19. Production of both esters and biogas from Mexican poppy

    African Journals Online (AJOL)

    AJL

    Methanol gives good separation of ester with A. mexicana compared to ethanol and A. mexicana methyl ester showed closer physical property to diesel. Calorific value of seed waste was 4621 Kcal/Kg and C/N ratio was 11. The experiment for biogas production was accomplished in two conditions viz sunlight (22- 30°C) ...

  20. The Preparation and Enzymatic Hydrolysis of a Library of Esters

    Science.gov (United States)

    Sanford, Elizabeth M.; Smith, Traci L.

    2008-01-01

    An investigative case study involving the preparation of a library of esters using Fischer esterification and alcoholysis of acid chlorides and their subsequent enzymatic hydrolysis by pig liver esterase and orange peel esterase is described. Students work collaboratively to prepare and characterize the library of esters and complete and evaluate…

  1. Oxo-ester mediated native chemical ligation: concept and applications.

    Science.gov (United States)

    Wan, Qian; Chen, Jin; Yuan, Yu; Danishefsky, Samuel J

    2008-11-26

    A direct oxo-ester peptide ligation method has been developed. Through the use of an activated C-terminal para nitrophenyl ester (1), it is possible to achieve direct cysteine ligations (1 + 2 --> 4). Peptide substrates incorporating bulky C-terminal amino acids (1) can be accommodated with high reaction efficiency.

  2. 13-week oral toxicity study with stanol esters in rats

    NARCIS (Netherlands)

    Turnbull, D.; Whittaker, M.H.; Frankos, V.H.; Jonker, D.

    1999-01-01

    Plant sterols and their saturated derivatives, known as stanols, reduce serum cholesterol when consumed in amounts of approximately 2 g per day. Stanol fatty acid esters have been developed as a highly fat-soluble form that may lower cholesterol more effectively than stanols. Stanol esters occur

  3. Preparation and characterization of aliphatic diphenyl esters intended as precursors for polyesters

    DEFF Research Database (Denmark)

    Hvilsted, S.; Andruzzi, F.; Cerrai, P.

    1991-01-01

    based on similar data from phenyl esters, interpreted as the results of an apparent macrocyclic conformation of the larger diphenyl esters. High-performance size exclusion chromatography (s.e.c.) of diphenyl esters, phenyl esters, aromatic and linear hydrocarbons in tetrahydrofuran, toluene...... and chloroform points to specific phenyl ester-solvent interactions, which obscure a potential s.e.c. conformational analysis of the diphenyl esters....

  4. Meltable dextran esters as biocompatible and functional coating materials.

    Science.gov (United States)

    Liebert, Tim; Wotschadlo, Jana; Laudeley, Peggy; Heinze, Thomas

    2011-08-08

    The conversion of dextran with in situ synthesized iminium chlorides of long chain carboxylic acids was used to obtain pure and defined melting dextran esters in an efficient one-pot synthesis. The melting point of these esters can be tailored by the degree of substitutions (DS), the molecular weight of the starting polymer, and the chain length of the ester moiety. The dextran esters give homogeneous and completely transparent melts, which form stable films on a broad variety of materials. Even complex geometries, such as implants, can be evenly coated by multiple melting steps. The films do not display any inhomogeneity and have a very low surface roughness. Therefore, no unspecific protein binding is observed. Moreover, the dextran esters are biocompatible as demonstrated for the interaction with three types of cells namely human brain microvascular endothelial cell, primary human fibroblasts, and mouse myoblast cells.

  5. Rapid NIR determination of alkyl esters in virgin olive oil

    Directory of Open Access Journals (Sweden)

    J. A. Cayuela

    2017-06-01

    Full Text Available The regulation of The European Union for olive oil and olive pomace established the limit of 35 mg·kg-1 for fatty acids ethyl ester contents in extra virgin olive oils, from grinding seasons after 2016. In this work, predictive models have been established for measuring fatty acid ethyl and methyl esters and to measure the total fatty acid alkyl esters based on near infrared spectroscopy (NIRS, and used successfully for this purpose. The correlation coefficients from the external validation exercises carried out with these predictive models ranged from 0.84 to 0.91. Different classification tests using the same models for the thresholds 35 mg·kg-1 for fatty acid ethyl esters and 75 mg·kg-1 for fatty acid alkyl esters provided success percentages from 75.0% to 95.2%.

  6. Differential partitioning of triterpenes and triterpene esters in apple peel

    Science.gov (United States)

    Apple peel functions as a protective barrier against biotic and abiotic stresses, and preserving the integrity and appearance of peel critical for market acceptance. Peel epidermal cells and epicuticular wax are a rich source of secondary metabolites, including triterpenes. Several studies have ou...

  7. Stem Cell Basics

    Science.gov (United States)

    ... Tips Info Center Research Topics Federal Policy Glossary Stem Cell Information General Information Clinical Trials Funding Information Current ... Basics » Stem Cell Basics I. Back to top Stem Cell Basics I. Introduction: What are stem cells, and ...

  8. Ultrastructure of Wax-Producing Structures on the Integument of the Melaleuca Psyllid Boreioglycaspis melaleucae (Hemiptera: Psyllidae, with Honeydew Excretion Behavior in Males and Females.

    Directory of Open Access Journals (Sweden)

    El-Desouky Ammar

    Full Text Available The melaleuca psyllid, Boreioglycaspis melaleucae (Hemiptera: Psyllidae, was introduced to Florida as a biological control agent against Melaleuca quinquenervia, an invasive evergreen tree that has invaded large areas of Florida Everglades. Colonies of B. melaleucae nymphs are normally covered by white waxy secretions, and nymphs of various instars produce long bundles of white waxy filaments extending laterally and posteriorly from their abdomen. Scanning electron microscopy of 'naturally waxed' and 'dewaxed' nymphs (cleaned from wax revealed two types of wax pore plates located dorsally and laterally on the integument of posterior abdominal segments starting with the 4th segment. Type-1 wax pore plates, with raised rim, peripheral groove, slits and pits, produce long ribbons and filaments of waxy secretions that are wound together forming long wax bundles, whereas type-2 wax pore plates, with slits only, produce shorter wax curls. Additionally, in both nymphs and adult females, the circumanal ring contained ornate rows of wax pores that produce wax filaments covering their honeydew excretions. Video recordings with stereomicroscopy showed that adult females produce whitish honeydew balls, powerfully propelled away from their body, probably to get these sticky excretions away from their eggs and newly hatched nymphs. Adult males, however, produce clear droplets of honeydew immediately behind them, simply by bending the posterior end of the abdomen downward. The possible role(s of waxy secretions by nymphs and adults of B. melaleucae in reducing contamination of their colonies with honeydew, among other possibilities, are discussed.

  9. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-06-14

    Methods and systems for making dibasic esters and/or dibasic acids using metathesis are generally disclosed. In some embodiments, the methods comprise reacting a terminal olefin ester with an internal olefin ester in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In some embodiments, the terminal olefin ester or the internal olefin ester are derived from a renewable feedstock, such as a natural oil feedstock. In some such embodiments, the natural oil feedstock, or a transesterified derivative thereof, is metathesized to make the terminal olefin ester or the internal olefin ester.

  10. Epicuticular waxes from caatinga and cerrado species and their efficiency against water loss

    Directory of Open Access Journals (Sweden)

    Antonio F. M. Oliveira

    2003-12-01

    Full Text Available The effects of the contents and chemical composition of the foliar epicuticular waxes of species from the caatinga (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida and Ziziphus joazeiro and cerrado (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina and Tocoyena formosa were evaluated as to the resistance to water loss by means of an experimental device constructed for this purpose. In general, the waxes of the caatinga species investigated were more efficient against water loss than cerrado species. Increase of the thickness of the waxy deposits from 40 to 90m g.cm-2 had no significant effect on the resistance to water loss. The chemistry of the wax constituents was shown to be an important factor to determine the degree of resistance to evaporation. n-Alkanes and alcoholic triterpenes were the most efficient barriers, while hentriacontan-16-one (a ketone and ursolic acid (an acid triterpene revealed lowefficiency. The higher efficiency of the waxes of the leaves from caatinga species (mainly those of C. yco and Z. joazeiro is probably accounted for the predominance of n-alkanes in their composition. The lower efficiency of the waxes of A. pyrifolium (caatinga, T. formosa and A. esperanzae (both species from the cerrado is probably a consequence of the predominance of triterpenoids in the waxes of the two former species and hentriacontan-16-one in the latter.A influência do teor e da composição química das ceras epicuticulares foliares de espécies da caatinga (Aspidosperma pyrifolium, Capparis yco, Maytenus rigida e Ziziphus joazeiro e do cerrado (Aristolochia esperanzae, Didymopanax vinosum, Strychnos pseudoquina e Tocoyena formosa foram avaliadas em relação à resistência à perda de água, através de um dispositivo experimental construído para essa finalidade. Em geral, as ceras das espécies da caatinga foram mais eficientes contra a perda de água que as das espécies do cerrado. O aumento da espessura dos

  11. Hydrogen isotope fractionation in leaf waxes in the Alaskan Arctic tundra

    Science.gov (United States)

    Daniels, William C.; Russell, James M.; Giblin, Anne E.; Welker, Jeffrey M.; Klein, Eric S.; Huang, Yongsong

    2017-09-01

    Leaf wax hydrogen isotopes (δDwax) are increasingly utilized in terrestrial paleoclimate research. Applications of this proxy must be grounded by studies of the modern controls on δDwax, including the ecophysiological controls on isotope fractionation at both the plant and landscape scales. Several calibration studies suggest a considerably smaller apparent fractionation between source water and waxes (εapp) at high latitudes relative to temperate or tropical locations, with major implications for paleoclimatic interpretations of sedimentary δDwax. Here we investigate apparent fractionation in the Arctic by tracing the isotopic composition of leaf waxes from production in modern plants to deposition in lake sediments using isotopic observations of precipitation, soil and plant waters, living leaf waxes, and waxes in sediment traps in the Brooks Range foothills of northern Alaska. We also analyze a lake surface sediment transect to compare present-day vegetation assemblages to εapp at the watershed scale. Source water and εapp were determined for live specimens of Eriophorum vaginatum (cottongrass) and Betula nana (dwarf birch), two dominant tundra plants in the Brooks Range foothills. The δD of these plants' xylem water closely tracks that of surface soil water, and reflects a summer-biased precipitation source. Leaf water is enriched by 23 ± 15‰ relative to xylem water for E. vaginatum and by 41 ± 19‰ for B. nana. Evapotranspiration modeling indicates that this leaf water enrichment is consistent with the evaporative enrichment expected under the climate conditions of northern Alaska, and that 24-h photosynthesis does not cause excessive leaf water isotope enrichment. The εapp determined for our study species average -89 ± 14‰ and -106 ± 16‰ for B. nana n-alkanes and n-acids, respectively, and -182 ± 10‰ and -154 ± 26‰ for E. vaginatum n-alkanes and n-acids, which are similar to the εapp of related species in temperate and tropical

  12. Surfactant-free carnauba wax dispersion and its use for layer-by-layer assembled protective surface coatings on wood

    Energy Technology Data Exchange (ETDEWEB)

    Lozhechnikova, Alina [Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 16300, FI-00076, Aalto (Finland); Bellanger, Hervé; Michen, Benjamin; Burgert, Ingo [Institute for Building Materials (IfB), Wood Materials Science, ETH Zürich, Stefano-Franscini-Platz 3, 8093 Zürich (Switzerland); Applied Wood Materials Laboratory, Empa − Swiss Federal Laboratories for Material Testing and Research, 8600 Dübendorf (Switzerland); Österberg, Monika, E-mail: monika.osterberg@aalto.fi [Department of Forest Products Technology, School of Chemical Technology, Aalto University, P.O. Box 16300, FI-00076, Aalto (Finland)

    2017-02-28

    Highlights: • A facile sonication route to produce aqueous wax dispersions is developed. • The wax dispersion is naturally stable and free of surfactants or stabilizers. • Wax and ZnO particles are coated onto wood using layer-by-layer assembly. • The coating brings superhydrophobicity while preserving moisture buffering. • ZnO improves the color stability of wood to UV light. - Abstract: Protection from liquid water and UV radiation are equally important, and a sophisticated approach is needed when developing surface coatings that preserve the natural and well-appreciated aesthetic appearance of wood. In order to prevent degradation and prolong the service life of timber, a protective coating was assembled using carnauba wax particles and zinc oxide nanoparticles via layer-by-layer deposition in water. For this purpose, a facile sonication route was developed to produce aqueous wax dispersion without any surfactants or stabilizers. The suspension was stable above pH 4 due to the electrostatic repulsion between the negatively charged wax particles. The particle size could be controlled by the initial wax concentration with average particle sizes ranging from 260 to 360 nm for 1 and 10 g/L, respectively. The deposition of wax particles onto the surface of spruce wood introduced additional roughness to the wood surface at micron level, while zinc oxide provided nano roughness and UV-absorbing properties. In addition to making wood superhydrophobic, this novel multilayer coating enhanced the natural moisture buffering capability of spruce. Moreover, wood surfaces prepared in this fashion showed a significant reduction in color change after exposure to UV light. A degradation of the wax through photocatalytic activity of the ZnO particles was measured by FTIR, indicating that further studies are required to achieve long-term stability. Nevertheless, the developed coating showed a unique combination of superhydrophobicity and excellent moisture buffering

  13. Non-targeted chromatographic analyses of cuticular wax flavonoids from Physalis alkekengi L.

    Science.gov (United States)

    Kranjc, Eva; Albreht, Alen; Vovk, Irena; Makuc, Damjan; Plavec, Janez

    2016-03-11

    Since Chinese lantern (Physalis alkekengi L.) represents a rich source of various bioactive secondary metabolites, there is an urge for its detailed characterization. Non-polar flavonoid aglycones represent one of the few bioactive species found in plant's cuticular waxes. The separation of flavonoids is already extensively covered in the literature, but methods dedicated to separation and identification of methylated flavonoids are rather scarce. In the present study a non-targeted approach for the separation, isolation and identification of methylated flavonoids present in P. alkekengi L. var. franchetii cuticular waxes was established. A rapid and simple separation on HPTLC silica gel was developed for preliminary screening of flavonoids. Fast HPLC-UV-MS(n) and HPLC-UV methods using a C6-Phenyl and a C18 stationary phase were also developed, respectively. In both cases, the right combination of temperature and tetrahydrofuran, as a mobile phase modifier, were shown to be crucial for a baseline separation of all studied compounds. By employing a semi-preparative analog of the C18 column, a simultaneous isolation of pure unknown analytes was achieved. Using these developed methods in combination with NMR, four 3-O-methylated flavonols were detected and identified in P. alkekengi L. var. franchetii cuticular waxes: myricetin 3,7,3'-trimethyl ether, quercetin 3,7-dimethyl ether, myricetin 3,7,3',5'-tetramethyl ether and quercetin 3,7,3'-trimethyl ether. Moreover, the simple and fast isocratic HPLC-UV-MS(n) method (under 8min) should prove useful in quality control of P. alkekengi L. var. franchetii by enabling chromatographic fingerprinting of external methylated flavonols. Finally, a rationale for the mechanism of separation of these metabolites by HPLC is also given, which establishes a foundation for future development of chromatographic methods for methylated flavonols and related compounds. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Non-Invasive Delivery of dsRNA into De-Waxed Tick Eggs by Electroporation

    Science.gov (United States)

    Ruiz, Newton; de Abreu, Leonardo Araujo; Parizi, Luís Fernando; Kim, Tae Kwon; Mulenga, Albert; Braz, Gloria Regina Cardoso; Vaz, Itabajara da Silva; Logullo, Carlos

    2015-01-01

    RNA interference-mediated gene silencing was shown to be an efficient tool for validation of targets that may become anti-tick vaccine components. Here, we demonstrate the application of this approach in the validation of components of molecular signaling cascades, such as the Protein Kinase B (AKT) / Glycogen Synthase Kinase (GSK) axis during tick embryogenesis. It was shown that heptane and hypochlorite treatment of tick eggs can remove wax, affecting corium integrity and but not embryo development. Evidence of AKT and GSK dsRNA delivery into de-waxed eggs of via electroporation is provided. Primers designed to amplify part of the dsRNA delivered into the electroporated eggs dsRNA confirmed its entry in eggs. In addition, it was shown that electroporation is able to deliver the fluorescent stain, 4',6-diamidino-2-phenylindole (DAPI). To confirm gene silencing, a second set of primers was designed outside the dsRNA sequence of target gene. In this assay, the suppression of AKT and GSK transcripts (approximately 50% reduction in both genes) was demonstrated in 7-day-old eggs. Interestingly, silencing of GSK in 7-day-old eggs caused 25% reduction in hatching. Additionally, the effect of silencing AKT and GSK on embryo energy metabolism was evaluated. As expected, knockdown of AKT, which down regulates GSK, the suppressor of glycogen synthesis, decreased glycogen content in electroporated eggs. These data demonstrate that electroporation of de-waxed R. microplus eggs could be used for gene silencing in tick embryos, and improve the knowledge about arthropod embryogenesis. PMID:26091260

  15. RNA-Seq reveals leaf cuticular wax-related genes in Welsh onion.

    Science.gov (United States)

    Liu, Qianchun; Wen, Changlong; Zhao, Hong; Zhang, Liying; Wang, Jian; Wang, Yongqin

    2014-01-01

    The waxy cuticle plays a very important role in plant resistance to various biotic and abiotic stresses and is an important characteristic of Welsh onions. Two different types of biangan Welsh onions (BG) were selected for this study: BG, a wild-type covered by wax, which forms a continuous lipid membrane on its epidermal cells, and GLBG, a glossy mutant of BG whose epidermal cells are not covered by wax. To elucidate the waxy cuticle-related gene expression changes, we used RNA-Seq to compare these two Welsh onion varieties with distinct differences in cuticular wax. The de novo assembly yielded 42,881 putative unigenes, 25.41% of which are longer than 1,000 bp. Among the high-quality unique sequences, 22,289 (52.0%) had at least one significant match to an existing gene model. A total of 798 genes, representing 1.86% of the total putative unigenes, were differentially expressed between these two Welsh onion varieties. The expression patterns of four important unigenes that are related to waxy cuticle biosynthesis were confirmed by RT-qPCR and COG class annotation, which demonstrated that these genes play an important role in defense mechanisms and lipid transport and metabolism. To our knowledge, this study is the first exploration of the Welsh onion waxy cuticle. These results may help to reveal the molecular mechanisms underlying the waxy cuticle and will be useful for waxy gene cloning, genetics and breeding as well as phylogenetic and evolutionary studies of the Welsh onion.

  16. Non-Invasive Delivery of dsRNA into De-Waxed Tick Eggs by Electroporation.

    Directory of Open Access Journals (Sweden)

    Newton Ruiz

    Full Text Available RNA interference-mediated gene silencing was shown to be an efficient tool for validation of targets that may become anti-tick vaccine components. Here, we demonstrate the application of this approach in the validation of components of molecular signaling cascades, such as the Protein Kinase B (AKT/Glycogen Synthase Kinase (GSK axis during tick embryogenesis. It was shown that heptane and hypochlorite treatment of tick eggs can remove wax, affecting corium integrity and but not embryo development. Evidence of AKT and GSK dsRNA delivery into de-waxed eggs of via electroporation is provided. Primers designed to amplify part of the dsRNA delivered into the electroporated eggs dsRNA confirmed its entry in eggs. In addition, it was shown that electroporation is able to deliver the fluorescent stain, 4',6-diamidino-2-phenylindole (DAPI. To confirm gene silencing, a second set of primers was designed outside the dsRNA sequence of target gene. In this assay, the suppression of AKT and GSK transcripts (approximately 50% reduction in both genes was demonstrated in 7-day-old eggs. Interestingly, silencing of GSK in 7-day-old eggs caused 25% reduction in hatching. Additionally, the effect of silencing AKT and GSK on embryo energy metabolism was evaluated. As expected, knockdown of AKT, which down regulates GSK, the suppressor of glycogen synthesis, decreased glycogen content in electroporated eggs. These data demonstrate that electroporation of de-waxed R. microplus eggs could be used for gene silencing in tick embryos, and improve the knowledge about arthropod embryogenesis.

  17. Natural wax constituents of a supercritical fluid CO(2) extract from quince (Cydonia oblonga Mill.) pomace.

    Science.gov (United States)

    Lorenz, Peter; Berger, Melanie; Bertrams, Julia; Wende, Kristian; Wenzel, Kristin; Lindequist, Ulrike; Meyer, Ulrich; Stintzing, Florian C

    2008-05-01

    The chemical constituents of a lipophilic extract from quince (Cydonia oblonga Mill.), obtained by supercritical fluid CO(2) extraction of the dried fruit pomace were investigated. Solvent partition of quince wax with n-hexane or acetone yielded an insoluble (crystalline) and a soluble (oily) fraction. Both fractions were analyzed separately using gas chromatography/mass spectrometry (GC/MS). The insoluble fraction consisted of saturated n-aldehydes, n-alcohols and free n-alkanoic acids of carbon chain lengths between 22 and 32, with carbon chain lengths of 26 and 28 dominating. Also odd-numbered unbranched hydrocarbons, mainly C27, C29 and C31, were detected particularly in the acetone-insoluble fraction (total, 15.8%). By means of vacuum liquid chromatography, triterpenoic acids were separated from the hexane-insoluble matter and identified as a mixture of ursolic, oleanolic and betulinic acids. The major constituents of the hexane-soluble fraction were glycerides of linoleic [Δ(9,12), 18:2] and oleic [Δ(9), 18:1] acids, accompanied by free linoleic, oleic and palmitic acids (C16). Moreover β-sitosterol, Δ(5)-avenasterol as well as trace amounts of other sterols were assigned. Finally the carotenoids phytoene and phytofluene were identified and quantified by UV/vis and high-performance liquid chromatography/MS techniques, yielding 1.0 and 0.3% of the quince wax, respectively. It is anticipated that the complex of lipid constituents from quince wax may exert interesting biological activities, the elucidation of which awaits further studies.

  18. The Preparation and Performances of Self-Dispersed Nanomicron Emulsified Wax Solid Lubricant Ewax for Drilling Fluids

    Directory of Open Access Journals (Sweden)

    Feng-shan Zhou

    2014-01-01

    Full Text Available An oil-in-water nanomicron wax emulsion with oil phase content 45 wt% was prepared by using the emulsifying method of surfactant-in-oil. The optimum prepared condition is 85°C, 20 min, and 5 wt% complex emulsifiers. Then the abovementioned nanomicron emulsifying wax was immersed into a special water-soluble polymer in a certain percentage by the semidry technology. At last, a solidified self-dispersed nanomicron emulsified wax named as Ewax, a kind of solid lubricant for water based drilling fluid, was obtained after dried in the special soluble polymer containing emulsifying wax in low temperature. It is shown that the adhesion coefficient reduced rate (ΔKf is 73.5% and the extreme pressure (E-P friction coefficient reduced rate (Δf is 77.6% when the produced Ewax sample was added to fresh water based drilling fluid at dosage 1.0 wt%. In comparison with other normal similar liquid products, Ewax not only has better performances of lubrication, filtration loss control property, heat resistance, and tolerance to salt and is environmentally friendly, but also can solve the problems of freezing in the winter and poor storage stability of liquid wax emulsion in oilfield applications.

  19. Morphological responses of the Wax Lake Delta, Louisiana, to Hurricanes Rita

    OpenAIRE

    Fei Xing; James P.M. Syvitski; Albert J. Kettner; Ehab A. Meselhe; John H. Atkinson; Ashok K. Khadka

    2017-01-01

    This study examines the morphodynamic response of a deltaic system to extreme weather events. The Wax Lake Delta (WLD) in Louisiana, USA, is used to illustrate the impact of extreme events (hurricanes) on a river-dominated deltaic system. Simulations using the open source Delft3D model reveal that Hurricane Rita, which made landfall 120 km to the west of WLD as a Category 3 storm in 2005, caused erosion on the right side and deposition on the left side of the hurricane eye track on the contin...

  20. Sorghum Resistance to the Sugarcane Aphid, Melanaphis sacchari (Zehntenr) Amounts of Surface Wax and Nutritional Components

    OpenAIRE

    積木, 久明; 兼久, 勝夫; Moharramipour, Saeid

    1995-01-01

    The differences in the amounts of leaf surface wax and nutritional components such as sugar and free amino acids were compared among resistant (PE 954177), moderately resistant (IS 84) and susceptible (Redlan B) sorghum varieties to the sugarcane aphid. Melanaphis sacchari (Zehntner). (1) The kind of aphid appearing on the leaves of the sorghum varieties was only the sugarcane aphid, Melanaphis sacchari in the field. The number of aphids infesting a leaf was ca 0,30 and 3,500 in the resistant...

  1. Cloning and Characterization of the dominant Inhibitor of Wax 1 (Iw1) gene in polyploid wheat

    OpenAIRE

    Adamski, Nikolai

    2013-01-01

    The Inhibitor of Wax 1 (Iw1) is a dominant inhibitor of glaucousness, the whitish waxy bloom present on the aerial surfaces of a wheat plant: The presence of Iw1 leads to non-glaucousness. In previous work a doubled-haploid population segregating for the presence of the Iw1 locus was created. The non-glaucous doubled-haploid lines of this population showed increases in yield and green-canopy duration under UK conditions compared to their glaucous counterparts by on average 4.15% and 1.5 days,...

  2. Hydrogen isotope composition of leaf wax n-alkanes in Arabidopsis lines with different transpiration rates

    Science.gov (United States)

    Pedentchouk, N.; Lawson, T.; Eley, Y.; McAusland, L.

    2012-04-01

    Stable isotopic compositions of oxygen and hydrogen are used widely to investigate modern and ancient water cycles. The D/H composition of organic compounds derived from terrestrial plants has recently attracted significant attention as a proxy for palaeohydrology. However, the role of various plant physiological and biochemical factors in controlling the D/H signature of leaf wax lipids in extant plants remains unclear. The focus of this study is to investigate the effect of plant transpiration on the D/H composition of n-alkanes in terrestrial plants. This experiment includes 4 varieties of Arabidopsis thaliana that differ with respect to stomatal density and stomatal geometry. All 4 varieties were grown indoors under identical temperature, relative humidity, light and watering regimes and then sampled for leaf wax and leaf water stable isotopic measurements. During growth, stomatal conductance to carbon dioxide and water vapour were also determined. We found that the plants varied significantly in terms of their transpiration rates. Transpiration rates were significantly higher in Arabidopsis ost1 and ost1-1 varieties (2.4 and 3.2 mmol m-2 s-1, respectively) than in Arabidopsis RbohD and Col-0 (1.5 and 1.4). However, hydrogen isotope measurements of n-alkanes extracted from leaf waxes revealed a very different pattern. Varieties ost1, ost1-1, and RbohD have very similar deltaD values of n-C29 alkane (-125, -128, and -127 per mil), whereas the deltaD value of Col-0 is more negative (-137 per mil). The initial results of this work suggest that plant transpiration is decoupled from the D/H composition of n-alkanes. In other words, physical processes that affect water vapour movement between the plant and its environment apparently cannot account for the stable hydrogen isotope composition of organic compounds that comprise leaf waxes. Additional, perhaps biochemical, processes that affect hydrogen isotope fractionation during photosynthesis might need to be invoked

  3. Pesticides for apicultural and/or agricultural application found in Belgian honey bee wax combs

    OpenAIRE

    Ravoet, Jorgen; Reybroeck, Wim; de Graaf, Dirk

    2015-01-01

    In a Belgian pilot study honey bee wax combs from ten hives were analyzed on the presence of almost 300 organochlorine and organophosphorous compounds by LC?MS/MS and GC?MS/MS. Traces of 18 pesticides were found and not a single sample was free of residues. The number of residues found per sample ranged from 3 to 13, and the pesticides found could be categorized as (1) pesticides for solely apicultural (veterinary) application, (2) pesticides for solely agricultural (crop protection) applicat...

  4. Antimicrobial activity of wax and hexane extracts from Citrus spp. peels

    Directory of Open Access Journals (Sweden)

    Susana Johann

    2007-09-01

    Full Text Available Antibacterial and antifungal properties of wax and hexane extracts of Citrus spp. peels were tested using bioautographic and microdilution techniques against three plant pathogenic fungi (Penicillium digitatum, Curvularia sp., and Colletotrichum sp., two human pathogens (Trichophyton mentagrophytes and Microsporum canis, and two opportunistic bacteria (Escherichia coli and Staphylococcus aureus. Two polymethoxylated flavonoids and a coumarin derivative, were isolated and identified from peel extracts, which presented antimicrobial activity especially against M. canis and T. mentagrophytes: 4',5,6,7,8-pentamethoxyflavone (tangeritin and 3',4',5,6,7,8-hexamethoxyflavone (nobiletin from C. reticulata; and 6,7-dimethoxycoumarin (also known as escoparone, scoparone or scoparin from C. limon.

  5. Low severity upgrading of F-T waxes with solid superacids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wender, I.; Tierney, J.W.

    1995-09-30

    The use of solid acids, especially Pt/ZrO{sub 2}/SO{sub 4}, to convert long chain alkanes and Fischer-Tropsch waxes to liquid fuels under mild reaction conditions was explored in this work. Anion and/or hydrogenation metal modified zirconium oxides were synthesized, characterized, and tested for hydrocracking and hydroisomerization. of model compounds, chiefly with n-hexadecane. The relationship between catalytic activity and acidic character of the bifunctional Pt/ZrO{sub 2}/SO{sub 4} catalyst was investigated.

  6. Why STEM?

    Science.gov (United States)

    Mitts, Charles R.

    2016-01-01

    The International Technology and Engineering Educators Association (ITEEA) defines STEM as a new transdisciplinary subject in schools that integrates the disciplines of science, technology, engineering, and mathematics into a single course of study. There are three major problems with this definition: There is no consensus in support of the ITEEA…

  7. STEM Thinking!

    Science.gov (United States)

    Reeve, Edward M.

    2015-01-01

    Science, Technology, Engineering, and Mathematics (STEM) is a term seen almost daily in the news. In 2009, President Obama launched the Educate to Innovate initiative to move American students from the middle to the top of the pack in science and math achievement over the next decade (The White House, n.d.). Learning about the attributes of STEM…

  8. The glossyhead1 allele of acc1 reveals a principal role for multidomain acetyl-coenzyme a carboxylase in the biosynthesis of cuticular waxes by Arabidopsis

    KAUST Repository

    Lu, Shiyou

    2011-09-23

    A novel mutant of Arabidopsis (Arabidopsis thaliana), having highly glossy inflorescence stems, postgenital fusion in floral organs, and reduced fertility, was isolated from an ethyl methanesulfonate-mutagenized population and designated glossyhead1 (gsd1). The gsd1 locus was mapped to chromosome 1, and the causal gene was identified as a new allele of Acetyl-Coenzyme A Carboxylase1 (ACC1), a gene encoding the main enzyme in cytosolic malonyl-coenzyme A synthesis. This, to our knowledge, is the first mutant allele of ACC1 that does not cause lethality at the seed or early germination stage, allowing for the first time a detailed analysis of ACC1 function in mature tissues. Broad lipid profiling of mature gsd1 organs revealed a primary role for ACC1 in the biosynthesis of the very-long-chain fatty acids (C 20:0 or longer) associated with cuticular waxes and triacylglycerols. Unexpectedly, transcriptome analysis revealed that gsd1 has limited impact on any lipid metabolic networks but instead has a large effect on environmental stress-responsive pathways, especially senescence and ethylene synthesis determinants, indicating a possible role for the cytosolic malonyl-coenzyme A-derived lipids in stress response signaling. © 2011 American Society of Plant Biologists. All Rights Reserved.

  9. Experimental Study on Shear Fatigue Behavior and Stiffness Performance of Warm Mix Asphalt by adding Synthetic Wax

    CERN Document Server

    Petit, Christophe; Canestrari, Francesco; Pannunzio, Valter; Virgili, Amadeo

    2012-01-01

    Synthetic waxes produced by standard and registered processes may be used to manufacture Warm Mix Asphalt (WMA), which is a modified asphalt concrete produced, applied and compacted at temperatures below those typically required. This feature leads to environmental benefits, such as reduced energy consumption, gas and fume emissions, as well as to economic/operational advantages, such as lower production costs and greater hauling distances for extended construction seasons with tighter schedules. The present article serves to compare the mechanical performance of a WMA produced by adding synthetic wax with a traditional Hot Mix Asphalt (HMA) specimen, in terms of shear fatigue response and both complex and stiffness moduli. The experimental results and related modeling work demonstrate that adding synthetic wax into the WMA composition does not hinder either the destructive or non-destructive performance of an HMA, and this finding is corroborated by respectively measuring fatigue life and stiffness.

  10. Leaf surface wax is a source of plant methane formation under UV radiation and in the presence of oxygen

    DEFF Research Database (Denmark)

    Bruhn, Dan; Mikkelsen, Teis Nørgaard; Rolsted, M. M. M.

    2014-01-01

    layer, and UV transmittance of the cuticle differs among plant species. In some species, the cuticle effectively absorbs and/or reflects UV radiation. Thus, pectin may not necessarily contribute substantially to the UV radiation-induced CH4 emission measured at surface level in all species. Here, we......The terrestrial vegetation is a source of UV radiation-induced aerobic methane (CH4) release to the atmosphere. Hitherto pectin, a plant structural component, has been considered as the most likely precursor for this CH4 release. However, most of the leaf pectin is situated below the surface wax...... investigated the potential of the leaf surface wax itself as a source of UV radiationinduced leaf aerobic CH4 formation. Isolated leaf surface wax emitted CH4 at substantial rates in response to UV radiation. This discovery has implications for how the phenomenon should be scaled to global levels. In relation...

  11. Wax blockage

    Science.gov (United States)

    ... the ear is plugged Noises in the ear ( tinnitus ) Partial hearing loss, may get worse Treatment Most ... ear anatomy References Lee DJ, Roberts D. Topical therapies for external ear disorders. In: Flint PW, Haughey ...

  12. Sugar ester surfactants: enzymatic synthesis and applications in food industry.

    Science.gov (United States)

    Neta, Nair S; Teixeira, José A; Rodrigues, Lígia R

    2015-01-01

    Sugar esters are non-ionic surfactants that can be synthesized in a single enzymatic reaction step using lipases. The stability and efficiency of lipases under unusual conditions and using non-conventional media can be significantly improved through immobilization and protein engineering. Also, the development of de novo enzymes has seen a significant increase lately under the scope of the new field of synthetic biology. Depending on the esterification degree and the nature of fatty acid and/or sugar, a range of sugar esters can be synthesized. Due to their surface activity and emulsifying capacity, sugar esters are promising for applications in food industry.

  13. Acyl-lupeol esters from Parahancornia amapa (Apocynaceae

    Directory of Open Access Journals (Sweden)

    Carvalho Mário G. de

    2001-01-01

    Full Text Available From the roots of Parahancornia amapa, family Apocynaceae, the following compounds were isolated and identified nine new and ten known 3beta-O-acyl lupeol esters, beta-sitosterol, stigmasterol, beta-sitosterone, the triterpenoids beta-amyrin, alpha-amyrin, lupeol and their acetyl derivatives. The structures of these compounds were established by spectroscopic data, mainly ¹H and 13C (HBBD and DEPT NMR spectra. The methyl esters obtained by hydrolysis of acyl lupeol esters and methylation of the corresponding acids were characterized by MS-GC analysis.

  14. Surfactant-free carnauba wax dispersion and its use for layer-by-layer assembled protective surface coatings on wood

    Science.gov (United States)

    Lozhechnikova, Alina; Bellanger, Hervé; Michen, Benjamin; Burgert, Ingo; Österberg, Monika

    2017-02-01

    Protection from liquid water and UV radiation are equally important, and a sophisticated approach is needed when developing surface coatings that preserve the natural and well-appreciated aesthetic appearance of wood. In order to prevent degradation and prolong the service life of timber, a protective coating was assembled using carnauba wax particles and zinc oxide nanoparticles via layer-by-layer deposition in water. For this purpose, a facile sonication route was developed to produce aqueous wax dispersion without any surfactants or stabilizers. The suspension was stable above pH 4 due to the electrostatic repulsion between the negatively charged wax particles. The particle size could be controlled by the initial wax concentration with average particle sizes ranging from 260 to 360 nm for 1 and 10 g/L, respectively. The deposition of wax particles onto the surface of spruce wood introduced additional roughness to the wood surface at micron level, while zinc oxide provided nano roughness and UV-absorbing properties. In addition to making wood superhydrophobic, this novel multilayer coating enhanced the natural moisture buffering capability of spruce. Moreover, wood surfaces prepared in this fashion showed a significant reduction in color change after exposure to UV light. A degradation of the wax through photocatalytic activity of the ZnO particles was measured by FTIR, indicating that further studies are required to achieve long-term stability. Nevertheless, the developed coating showed a unique combination of superhydrophobicity and excellent moisture buffering ability and some UV protection, all achieved using an environmentally friendly coating process, which is beneficial to retain the natural appearance of wood and improve indoor air quality and comfort.

  15. The Biology and Control of the Greater Wax Moth, Galleria mellonella.

    Science.gov (United States)

    Kwadha, Charles A; Ong'amo, George O; Ndegwa, Paul N; Raina, Suresh K; Fombong, Ayuka T

    2017-06-09

    The greater wax moth, Galleria mellonella Linnaeus, is a ubiquitous pest of the honeybee, Apis mellifera Linnaeus, and Apis cerana Fabricius. The greater wax moth larvae burrow into the edge of unsealed cells with pollen, bee brood, and honey through to the midrib of honeybee comb. Burrowing larvae leave behind masses of webs which causes galleriasis and later absconding of colonies. The damage caused by G. mellonella larvae is severe in tropical and sub-tropical regions, and is believed to be one of the contributing factors to the decline in both feral and wild honeybee populations. Previously, the pest was considered a nuisance in honeybee colonies, therefore, most studies have focused on the pest as a model for in vivo studies of toxicology and pathogenicity. It is currently widespread, especially in Africa, and the potential of transmitting honeybee viruses has raised legitimate concern, thus, there is need for more studies to find sustainable integrated management strategies. However, our knowledge of this pest is limited. This review provides an overview of the current knowledge on the biology, distribution, economic damage, and management options. In addition, we provide prospects that need consideration for better understanding and management of the pest.

  16. Sex-specific compensatory growth in the larvae of the greater wax moth Galleria mellonella.

    Science.gov (United States)

    Kecko, S; Mihailova, A; Kangassalo, K; Elferts, D; Krama, T; Krams, R; Luoto, S; Rantala, M J; Krams, I A

    2017-10-01

    Deficiency of food resources in ontogeny is known to prolong an organism's developmental time and affect body size in adulthood. Yet life-history traits are plastic: an organism can increase its growth rate to compensate for a period of slow growth, a phenomenon known as 'compensatory growth'. We tested whether larvae of the greater wax moth Galleria mellonella can accelerate their growth after a fast of 12, 24 or 72 h. We found that a subgroup of female larvae showed compensatory growth when starved for 12 h. Food deficiency lasting more than 12 h resulted in longer development and lower mass gain. Strength of encapsulation reactions against a foreign body inserted in haemocoel was the weakest in females that showed compensatory growth, whereas the strongest encapsulation was recorded in the males and females that fasted for 24 and 72 h. More specifically, we found sex-biased immune reactions so that females had stronger encapsulation rates than males in one group that fasted for 72 h. Overall, rapidly growing females had a short larval development period and the shortest adult lifespan. These results suggest that highly dynamic trade-offs between the environment, life-history traits and sex lead to plasticity in developmental strategies/growth rates in the greater wax moth. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  17. Tidal modulated flow and sediment flux through Wax Lake Delta distributary channels: Implications for delta development

    Directory of Open Access Journals (Sweden)

    K. Hanegan

    2015-03-01

    Full Text Available In this study, a Delft3D model of the Wax Lake Delta was developed to simulate flow and sediment flux through delta distributary channels. The model was calibrated for tidal constituents as well as velocity and sediment concentration across channel transects. The calibrated model was then used to simulate full spring–neap tidal cycles under constant low flow upstream boundary conditions, with grain size variation in suspended load represented using two sediment fractions. Flow and sediment flux results through distributary channel cross-sections were examined for spatial and temporal variability with the goal of characterizing the role of tides in sediment reworking and delta development. The Wax Lake Delta has prograded through channel extension, river mouth bar deposition, and channel bifurcation. Here we show that tidal modulation of currents influences suspended sand transport, and spatial acceleration through distributary channels at low tides is sufficient to suspend sand in distal reaches during lower flows. The basinward-increasing transport capacity in distributary channels indicates that erosive channel extension could be an important process, even during non-flood events.

  18. SEPARATION OF FISCHER-TROPSCH WAX FROM CATALYST BY SUPERCRITICAL EXTRACTION

    Energy Technology Data Exchange (ETDEWEB)

    Patrick C. Joyce; Mark C. Thies

    1999-03-31

    The objective of this research project was to evaluate the potential of supercritical fluid (SCF) extraction for the recovery and fractionation of the wax product from the slurry bubble column (SBC) reactor of the Fischer-Tropsch (F-T) process. The wax, comprised mostly of branched and linear alkanes with a broad molecular weight distribution up to C{sub 100}, is to be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300 C. Aspen Plus{trademark} was used to perform process simulation studies on the proposed extraction process, with Redlich-Kwong-Soave (RKS) being used for the thermodynamic property model. In summary, we have made comprehensive VLE measurements for short alkane + long alkane systems over a wide range of pressures and temperatures, dramatically increasing the amount of high-quality data available for these simple, yet highly relevant systems. In addition, our work has demonstrated that, surprisingly, no current thermodynamic model can adequately predict VLE behavior for these systems. Thus, process simulations (such as those for our proposed SCF extraction process) that incorporate these systems can currently only give results that are qualitative at best. Although significant progress has been made in the past decade, more experimental and theoretical work remain to be done before the phase equilibria of asymmetric alkane mixtures can be predicted with confidence.

  19. A case of butane hash oil (marijuana wax)-induced psychosis.

    Science.gov (United States)

    Keller, Corey J; Chen, Evan C; Brodsky, Kimberly; Yoon, Jong H

    2016-01-01

    Marijuana is one of the most widely used controlled substances in the United States. Despite extensive research on smoked marijuana, little is known regarding the potential psychotropic effects of marijuana "wax," a high-potency form of marijuana that is gaining in popularity. The authors present a case of "Mr. B," a 34-year-old veteran who presented with profound psychosis in the setting of recent initiation of heavy, daily marijuana wax use. He exhibited incoherent speech and odd behaviors and appeared to be in a dream-like state with perseverating thoughts about his combat experience. His condition persisted despite treatment with risperidone 4 mg twice a day (BID), but improved dramatically on day 8 of hospitalization with the return of baseline mental function. Following discharge, Mr. B discontinued all marijuana use and did not exhibit the return of any psychotic symptoms. This study highlights the need for future research regarding the potential medical and psychiatric effects of new, high-potency forms of marijuana. Could cannabis have a dose-dependent impact on psychosis? What other potential psychiatric effects could emerge heretofore unseen in lower potency formulations? Given the recent legalization of marijuana, these questions merit timely exploration.

  20. Separation of Fischer-Tropsch Wax Products from Ultrafine Iron Catalyst Particles

    Energy Technology Data Exchange (ETDEWEB)

    James K. Neathery; Gary Jacobs; Amitava Sarkar; Burtron H. Davis

    2006-03-31

    The morphological and chemical nature of ultrafine iron catalyst particles (3-5 nm diameters) during activation/FTS was studied by HRTEM, EELS, and Moessbauer spectroscopy. With the progress of FTS, the carbide re-oxidized to magnetite and catalyst activity gradually decreased. The growth of oxide phase continued and average particle size also increased simultaneously. The phase transformation occurred in a ''growing oxide core'' manner with different nano-zones. The nano-range carbide particles did not show fragmentation or attrition as generally observed in micrometer range particles. Nevertheless, when the dimension of particles reached the micrometer range, the crystalline carbide phase appeared to be sprouted on the surface of magnetite single crystal. In the previous reporting period, a design and operating philosophy was developed for an integrated wax filtration system for a 4 liter slurry bubble column reactor to be used in Phase II of this research program. During the current reporting period, we have started construction of the new filtration system and began modifications to the 4 liter slurry bubble column reactor (SBCR) reactor. The system will utilize a primary wax separation device followed by a Pall Accusep or Membralox ceramic cross-flow membrane. As of this writing, the unit is nearly complete except for the modification of a moyno-type pump; the pump was shipped to the manufacturer to install a special leak-free, high pressure seal.

  1. Multiresidue method for trace pesticide analysis in honeybee wax comb by GC-QqQ-MS.

    Science.gov (United States)

    García, M D Gil; Duque, S Uclés; Fernández, A B Lozano; Sosa, A; Fernández-Alba, A R

    2017-01-15

    The aim of this analytical study is to develop an improved multi-residue methodology of high sensitivity and expanded scope for pesticide residue analysis in honeybee wax combs. The method was validated for 160 pesticide residues (including acaricides, insecticides, fungicides and herbicides) gas chromatography amenable and covering a wide variety of polarity and chemical structure. This method of analysis applied gas chromatography coupled to a triple quadrupole mass spectrometer for the quantitative analysis of pesticide residues. The extraction procedure applied was based QuEChERs method allowing acceptable recoveries for most of the pesticides (98%), within the range 60-120% with an associated precision (RSD) wax comb samples randomly collected from different apiaries in Spain. A total of 32 pesticide residues (14 insecticides/acaricides, 10 insecticides, 6 fungicides and 2 herbicides) were detected in the samples. The highest pesticide concentrations were found for those with insecticide-acaricide activity like acrinathrin, chlorfenvinphos, coumaphos and fluvalinate-tau, some of them are mainly applied in apiculture for controlling the honeybee parasite Varroa destructor. The total load of pesticide residues ranged from 69 to 1000µgkg(-1) for 40% of the analysed samples, 22% contained pesticide residues in the ranges of 1000-2000µgkg(-1), 24% between 2000 and 5000µgkg(-1) and 14% of the samples contained residues between 5000 and 9557µgkg(-1). Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Phase Change Material Trade Study: A Comparison Between Wax and Water for Manned Spacecraft

    Science.gov (United States)

    Quinn, Gregory; Hodgson, Ed; Stephan, Ryan

    2010-01-01

    Phase change material heat sinks have been recognized as an important tool in optimizing thermal control systems for space exploration vehicles and habitats that must deal with widely varying thermal loads and environments. In order to better focus technology investment in this arena, NASA has supported a trade study with the objective of identifying where the best potential pay-off can be found among identified aqueous and paraffin wax phase change materials and phase change material heat sink design approaches. The study used a representative exploration mission with well understood parameters to support the trade. Additional sensitivity studies were performed to ensure the applicability of study results across varying systems and destinations. Results from the study indicate that a water ice PCM heat sink has the potential to decrease the equivalent system mass of the mission s vehicle through a combination of a smaller heat sink and a slight 5% increase in radiator size or the addition of a lightweight heat pump. An evaluation of existing and emerging PCM heat sink technologies indicates that further significant mass savings should be achievable through continued development of those technologies. The largest mass savings may be realized by managing the location of the liquid and the solid in the heat sink to eliminate the melting and freezing pressure of wax and water, respectively, while also accommodating the high structural loads expected on future manned launch vehicles.

  3. Paraffin wax removal from metal injection moulded cocrmo alloy compact by solvent debinding process

    Science.gov (United States)

    Dandang, N. A. N.; Harun, W. S. W.; Khalil, N. Z.; Ahmad, A. H.; Romlay, F. R. M.; Johari, N. A.

    2017-10-01

    One of the most crucial and time consuming phase in metal injection moulding (MIM) process is “debinding”. These days, in metal injection moulding process, they had recounted that first debinding practice was depend on thermal binder degradation, which demanding more than 200 hours for complete removal of binder. Fortunately, these days world had introduced multi-stage debinding techniques to simplified the debinding time process. This research study variables for solvent debinding which are temperature and soaking time for samples made by MIM CoCrMo powder. Since wax as the key principal in the binder origination, paraffin wax will be removed together with stearic acid from the green bodies. Then, debinding process is conducted at 50, 60 and 70°C for 30-240 minutes. It is carried out in n-heptane solution. Percentage weight loss of the binder were measured. Lastly, scanning electron microscope (SEM) analysis and visual inspection were observed for the surface of brown compact. From the results, samples debound at 70°C exhibited a significant amount of binder loss; nevertheless, sample collapse, brittle surface and cracks were detected. But, at 60°C temperature and time of 4 hours proven finest results as it shows sufficient binder loss, nonappearance of surface cracks and easy to handle. Overall, binder loss is directly related to solvent debinding temperature and time.

  4. Anti-inflammatory effects of jojoba liquid wax in experimental models.

    Science.gov (United States)

    Habashy, Ramy R; Abdel-Naim, Ashraf B; Khalifa, Amani E; Al-Azizi, Mohammed M

    2005-02-01

    Jojoba [Simmondsia chinensis (Link 1822) Schneider 1907] is an arid perennial shrub grown in several American and African countries. Jojoba seeds, which are rich in liquid wax, were used in folk medicine for diverse ailments. In the current study, the potential anti-inflammatory activity of jojoba liquid wax (JLW) was evaluated in a number of experimental models. Results showed that JLW caused reduction of carrageenin-induced rat paw oedema in addition to diminishing prostaglandin E2 (PGE2) level in the inflammatory exudates. In a test for anti-inflammatory potential utilizing the chick's embryo chroioallantoic membrane (CAM), JLW also caused significant lowering of granulation tissue formation. Topical application of JLW reduced ear oedema induced by croton oil in rats. In the same animal model, JLW also reduced neutrophil infiltration, as indicated by decreased myeloperoxidase (MPO) activity. In addition, JLW ameliorated histopathological changes affected by croton oil application. In the lipopolysaccharide (LPS)-induced inflammation in air pouch in rats, JLW reduced nitric oxide (NO) level and tumor necrosis factor-alpha (TNF-alpha) release. In conclusion, this study demonstrates the effectiveness of JLW in combating inflammation in several experimental models. Further investigations are needed to identify the active constituents responsible for the anti-inflammatory property of JLW.

  5. The First 20 Hours of Geopolymerization: An in Situ WAXS Study of Flyash-Based Geopolymers.

    Science.gov (United States)

    Williams, Ross P; van Riessen, Arie

    2016-07-08

    This study followed the first 20 h of flyash geopolymerization at 70 °C using time resolved Wide Angle X-ray Scattering (WAXS). The extent of dissolution of the amorphous phase of the flyash was determined to range from 29% to 54% for the different formulations trialed. The dissolution rate of the flyash significantly reduced after the first 5 h for all samples. During the formation stage of the geopolymer there were significant temporal variations in the chemistry of the dissolved solution due to the rate of flyash dissolution, with a relative standard deviation of 20%, 57% and 24% for the Si/Al, Na/Al and H/Si ratios, respectively. Utilizing the Power Law, scattering in the low angle region of the WAXS pattern combined with the geopolymer peak area yielded a measure which correlated with the compressive strength-providing a new method to measure the flyash dissolution and geopolymer formation processes independently. The evolution of several zeolite-like phases was followed, noting there are different formation mechanisms involved even within the same sample. Four samples were examined with compressive strengths ranging from 14(2)-50(9) MPa, each was synthesized with flyash from Collie Power Station (Western Australia) activated with sodium silicate solution of varying concentrations.

  6. The First 20 Hours of Geopolymerization: An in Situ WAXS Study of Flyash-Based Geopolymers

    Directory of Open Access Journals (Sweden)

    Ross P. Williams

    2016-07-01

    Full Text Available This study followed the first 20 h of flyash geopolymerization at 70 °C using time resolved Wide Angle X-ray Scattering (WAXS. The extent of dissolution of the amorphous phase of the flyash was determined to range from 29% to 54% for the different formulations trialed. The dissolution rate of the flyash significantly reduced after the first 5 h for all samples. During the formation stage of the geopolymer there were significant temporal variations in the chemistry of the dissolved solution due to the rate of flyash dissolution, with a relative standard deviation of 20%, 57% and 24% for the Si/Al, Na/Al and H/Si ratios, respectively. Utilizing the Power Law, scattering in the low angle region of the WAXS pattern combined with the geopolymer peak area yielded a measure which correlated with the compressive strength—providing a new method to measure the flyash dissolution and geopolymer formation processes independently. The evolution of several zeolite-like phases was followed, noting there are different formation mechanisms involved even within the same sample. Four samples were examined with compressive strengths ranging from 14(2–50(9 MPa, each was synthesized with flyash from Collie Power Station (Western Australia activated with sodium silicate solution of varying concentrations.

  7. Supercritical fluid extraction as a clean-up method for the extraction of pesticides from wool wax. A preliminary approach.

    OpenAIRE

    Crespi, M.; Gutiérrez, M.C.; Carrillo, F.; Christoe, J; López-Mesas, M.

    2007-01-01

    The work presented is a preliminary study for the development of a method for the extraction of pesticides from wax samples by means of superficial fluid extraction. The novelty of the study is the direct extraction of the pesticides from raw wool wax without any cleanup, as direct extraction has been considered almost impossible by many authors.Este trabajo es un estudio preliminar para el desarrollo de un método de extracción de pesticidas directamente de las muestras de cera medi...

  8. To evaluate the efficacy of Mobilization Techniques in Post-Traumatic stiff ankle with and without Paraffin Wax Bath.

    Science.gov (United States)

    Rashid, Sajid; Salick, Kamran; Kashif, Muhammah; Ahmad, Awad; Sarwar, Kashif

    2013-11-01

    Mobilization techniques are frequently used by physiotherapists to reduce pain, improve joint movement and facilitate return to activities after injury. The objective of this study was to explore differences in the efficacy of Mobilization Techniques in Post-Traumatic stiff ankle with and without Paraffin Wax Bath. Thirty seven patients of Post Traumatic stiff ankle were recruited for the study at Sajid Physiotherapy & Rehabilitation center, Multan from March 2011 to February 2013. It was a randomized controlled trial and the patients with equal grades of severity were placed in control and study groups. Group A had nineteen patients and Group B had 18 patients. The inclusion criteria were age range from 20-60 years, pain, loss of ROM, with history of trauma and fracture of ankle. The patients with similar complaints but with surgical treatment were excluded. Group A was given mobilization techniques with paraffin wax bath while group B was treated without paraffin wax bath. Improvement was observed by EscolaPaulista de Medicina Range of Motion (EPM-ROM) scale and visual analogue scale (VAS). After ten weeks of treatment, the patients were re-evaluated by an orthopedic surgeon and a Physiotherapist for their symptoms and ROM. t-test was applied to compare outcome between two groups and p movement showed improvement in inversion in group A (0.875 ± 0.276) vs. group B (0.966 ± 0.305) and in eversion in group A (0.948 ± 0.300) vs. group B (0.674 ± 0.213). Mobilization Techniques followed by wax bath resulted in significant improvements of range of motion (ROM), clinical and functional changes. Wax bath alone had no significant effect. After ten weeks intervention treatment, t-test was applied to compare outcome between the two groups and p=0.001to 0.004 in group A and p= 0.104 to 0.168 in group B, (pmobilization and wax bath therapy is an effective and beneficial tool to improve the symptoms and quality of life in post traumatic stiff ankle patients. Joint

  9. Wax: A benign hydrogen-storage material that rapidly releases H2-rich gases through microwave-assisted catalytic decomposition.

    Science.gov (United States)

    Gonzalez-Cortes, S; Slocombe, D R; Xiao, T; Aldawsari, A; Yao, B; Kuznetsov, V L; Liberti, E; Kirkland, A I; Alkinani, M S; Al-Megren, H A; Thomas, J M; Edwards, P P

    2016-10-19

    Hydrogen is often described as the fuel of the future, especially for application in hydrogen powered fuel-cell vehicles (HFCV's). However, its widespread implementation in this role has been thwarted by the lack of a lightweight, safe, on-board hydrogen storage material. Here we show that benign, readily-available hydrocarbon wax is capable of rapidly releasing large amounts of hydrogen through microwave-assisted catalytic decomposition. This discovery offers a new material and system for safe and efficient hydrogen storage and could facilitate its application in a HFCV. Importantly, hydrogen storage materials made of wax can be manufactured through completely sustainable processes utilizing biomass or other renewable feedstocks.

  10. Cooling of High-Power LED Lamp Using a Commercial Paraffin Wax

    Science.gov (United States)

    Zmywaczyk, J.; Zbińkowski, P.; Smogór, H.; Olejnik, A.; Koniorczyk, P.

    2017-03-01

    Commercial paraffin wax used by Bolsius Nederland B.V. for manufacturing various kinds of candles was applied as a phase-change material (PCM) for cooling a 28 W high-power light emitting diode (LED) panel during its operation. The main problem arising during operation of an LED is thermal management. According to the manufacturer's datasheet specifications (BioSolution Ltd. www.biosolution.pl, the operating temperature range for the LED street lamp UL28W is (-30 {°}C) to (+40 {°}C). The object of the present study was an LED panel containing 28 pieces of high-power 1W LEDs connected in series (4 LEDs in each of the 7 rows) mounted on an aluminum plate of dimensions 80 mm by 135 mm. The tested aluminum plate was placed in a block made of aluminum with a hollow compartment containing Bolsius paraffin wax of density 914 kg\\cdot m^{-3} at room temperature. Temperatures were recorded using K-type thermocouples at selected locations of the tested LED panel for several values of the power supplied to it, while utilizing PCM and without it. As the manufacturer of Bolsius wax candles does not provide any data on the thermal properties of the material used, it was necessary to carry out micro-calorimetric research. Thermophysical properties of the paraffin wax such as the apparent specific heat, enthalpy of phase transition and temperature of phase change transition during heating and cooling were determined using the Netzsch DSC 214 Polyma. The Netzsch TG 209F3 Tarsus was used for TG/DTG measurements. DSC investigations revealed the following thermal transitions taking place during the first heating: solid-solid transition (onset 30.4 {°}C, peak at 40.9 {°}C), solid-liquid transition (onset 47.7 {°}C, peak at 54.9 {°}C, end at 58.3 {°}C), latent heat of energy storage 201 J\\cdot g^{-1}, apparent specific heat corresponding to peak at 41.5 {°}C (5.498 J\\cdot g^{-1}\\cdot K^{-1}). DTG investigations revealed that the decomposition of paraffin wax is a two

  11. Effect of local hemostatics on bone induction in rats: a comparative study of bone wax, fibrin-collagen paste, and bioerodible polyorthoester with and without gentamicin

    DEFF Research Database (Denmark)

    Solheim, E; Pinholt, E M; Bang, G

    1992-01-01

    evaluated by light microscopy and 85Sr uptake analyses. Non-absorbable bone wax of 88% beeswax and absorbable bovine fibrin-collagen paste both significantly inhibited osteoinduction, whereas a bioerodible polyorthoester drug delivery system with or without 4% gentamicin did not. Bone wax was not absorbed...

  12. Ultrastructure of Wax-Producing Structures on the Integument of the Melaleuca Psyllid Boreioglycaspis melaleucae (Hemiptera: Psyllidae), with Honeydew Excretion Behavior in Males and Females

    Science.gov (United States)

    Ammar, El-Desouky; Hentz, Matthew; Hall, David G.; Shatters, Robert G.

    2015-01-01

    The melaleuca psyllid, Boreioglycaspis melaleucae (Hemiptera: Psyllidae), was introduced to Florida as a biological control agent against Melaleuca quinquenervia, an invasive evergreen tree that has invaded large areas of Florida Everglades. Colonies of B. melaleucae nymphs are normally covered by white waxy secretions, and nymphs of various instars produce long bundles of white waxy filaments extending laterally and posteriorly from their abdomen. Scanning electron microscopy of ‘naturally waxed’ and ‘dewaxed’ nymphs (cleaned from wax) revealed two types of wax pore plates located dorsally and laterally on the integument of posterior abdominal segments starting with the 4th segment. Type-1 wax pore plates, with raised rim, peripheral groove, slits and pits, produce long ribbons and filaments of waxy secretions that are wound together forming long wax bundles, whereas type-2 wax pore plates, with slits only, produce shorter wax curls. Additionally, in both nymphs and adult females, the circumanal ring contained ornate rows of wax pores that produce wax filaments covering their honeydew excretions. Video recordings with stereomicroscopy showed that adult females produce whitish honeydew balls, powerfully propelled away from their body, probably to get these sticky excretions away from their eggs and newly hatched nymphs. Adult males, however, produce clear droplets of honeydew immediately behind them, simply by bending the posterior end of the abdomen downward. The possible role(s) of waxy secretions by nymphs and adults of B. melaleucae in reducing contamination of their colonies with honeydew, among other possibilities, are discussed. PMID:25793934

  13. Evolutionary Conserved Function of Barley and Arabidopsis 3-KETOACYL-CoA SYNTHASES in Providing Wax Signals for Germination of Powdery Mildew Fungi1[C][W

    Science.gov (United States)

    Weidenbach, Denise; Jansen, Marcus; Franke, Rochus B.; Hensel, Goetz; Weissgerber, Wiebke; Ulferts, Sylvia; Jansen, Irina; Schreiber, Lukas; Korzun, Viktor; Pontzen, Rolf; Kumlehn, Jochen; Pillen, Klaus; Schaffrath, Ulrich

    2014-01-01

    For plant pathogenic fungi, such as powdery mildews, that survive only on a limited number of host plant species, it is a matter of vital importance that their spores sense that they landed on the right spot to initiate germination as quickly as possible. We investigated a barley (Hordeum vulgare) mutant with reduced epicuticular leaf waxes on which spores of adapted and nonadapted powdery mildew fungi showed reduced germination. The barley gene responsible for the mutant wax phenotype was cloned in a forward genetic screen and identified to encode a 3-KETOACYL-CoA SYNTHASE (HvKCS6), a protein participating in fatty acid elongation and required for synthesis of epicuticular waxes. Gas chromatography-mass spectrometry analysis revealed that the mutant has significantly fewer aliphatic wax constituents with a chain length above C-24. Complementation of the mutant restored wild-type wax and overcame germination penalty, indicating that wax constituents less present on the mutant are a crucial clue for spore germination. Investigation of Arabidopsis (Arabidopsis thaliana) transgenic plants with sense silencing of Arabidopsis REQUIRED FOR CUTICULAR WAX PRODUCTION1, the HvKCS6 ortholog, revealed the same germination phenotype against adapted and nonadapted powdery mildew fungi. Our findings hint to an evolutionary conserved mechanism for sensing of plant surfaces among distantly related powdery mildews that is based on KCS6-derived wax components. Perception of such a signal must have been evolved before the monocot-dicot split took place approximately 150 million years ago. PMID:25201879

  14. Baker's yeast: production of D- and L-3-hydroxy esters

    DEFF Research Database (Denmark)

    Dahl, Allan Carsten; Madsen, Jørgen Øgaard

    1998-01-01

    Baker's yeast grown under oxygen limited conditions and used in the reduction of 3-oxo esters results in a shift of the stereoselectivity of the yeast towards D-hydroxy esters as compared with ordinary baker's yeast. The highest degree of stereoselectivity was obtained with growing yeast or yeast...... harvested while growing. In contrast, the stereoselectivity was shifted towards L-hydroxy esters when the oxo esters were added slowly to ordinary baker's yeast supplied with gluconolactone as co-substrate. The reduction rate with gluconolactone was increased by active aeration. Ethyl L-(S)-3......-hydroxybutanoate was afforded in >99% ee. Both enantiomers of ethyl 3-hydroxypentanoate, D-(R) in 96% ee and L-(S) in 93% ee, and of ethyl 4-chloro-3-hydroxybutanoate, D-(S) in 98% ee and L-(R) in 94% ee, were obtained. The results demonstrate that the stereoselectivity of baker's yeast can be controlled...

  15. Epoxy resin composition containing metal tetrafluoroborate and boron ester

    Energy Technology Data Exchange (ETDEWEB)

    Morehead, G.T.

    1990-06-12

    This patent describes a curable composition. It comprises: a polyepoxide; a metal tetrafluoroborate; and at least one boron ester selected from the group consisting of triesters of boric acid and diesters of boronic acid.

  16. Chemoenzymatic Synthesis and Chemical Recycling of Poly(ester-urethanes

    Directory of Open Access Journals (Sweden)

    Hiroto Hayashi

    2011-08-01

    Full Text Available Novel poly(ester-urethanes were prepared by a synthetic route using a lipase that avoids the use of hazardous diisocyanate. The urethane linkage was formed by the reaction of phenyl carbonate with amino acids and amino alcohols that produced urethane-containing diacids and hydroxy acids, respectively. The urethane diacid underwent polymerization with polyethylene glycol and a,w-alkanediols and also the urethane-containing hydroxy acid monomer was polymerized by the lipase to produce high-molecular-weight poly(ester-urethanes. The periodic introduction of ester linkages into the polyurethane chain by the lipase-catalyzed polymerization afforded chemically recyclable points. They were readily depolymerized in the presence of lipase into cyclic oligomers, which were readily repolymerized in the presence of the same enzyme. Due to the symmetrical structure of the polymers, poly(ester-urethanes synthesized in this study showed higher Tm, Young’s modulus and tensile strength values.

  17. Inert Reassessment Document for PEG Fatty Acid Esters

    Science.gov (United States)

    The tolerance reassessment decision document and action memorandum for the PEG fatty acid ester date September 28, 2005, included two tolerance exemptions (under 40 CFR 180.910 and $) CFR 180.930, respectively)

  18. Solid state crystallisation of oligosaccharide ester derivatives

    CERN Document Server

    Wright, E A

    2002-01-01

    An investigation of the solid state properties of oligosaccharide ester derivatives (OEDs) with potential applications in drug delivery has been carried out. The amorphous form of two OEDs, trehalose octa-acetate (TOAC) and 6:6'-di-(beta-tetraacetyl glucuronyl)-hexaacetyl trehalose (TR153), was investigated as a matrix for the sustained release of active ingredients. The matrices showed a tendency to crystallise and so polymorph screens were performed to provide crystalline samples for structural analysis. The crystal structures of TOAC methanolate and TR153 acetonitrile solvate have been determined by single-crystal laboratory X-ray diffraction. TOAC methanolate crystallises in the orthorhombic space group P2 sub 1 2 sub 1 2 sub 1 with a = 15.429(18) A, b = 17.934(19) A and c = 13.518(4) A at 123 K. The structure is isomorphous with the previously reported structure of TOAC monohydrate form II. TR153 acetonitrile solvate crystallises in the monoclinic spacegroup C2 with a = 30:160(6) A, b = 11.878(3) A, c 20...

  19. Use of fumaric acid esters in psoriasis.

    Science.gov (United States)

    Roll, Antonie; Reich, Kristian; Boer, Almut

    2007-01-01

    Fumaric acid esters (FAE) are chemical compounds derived from the unsaturated dicarbonic acid fumaric acid. The usage of FAEs in treatment of psoriasis was introduced in the late 1950's. In the 1980s more standardized oral preparations of FAEs were developed containing dimethylfumarate (DMF) and salts of monoethylfumarate (MEF) as main compounds. In 1994, Fumaderm an enteric-coated tablet containing DMF and calcium, magnesium and zinc salts of MEF was approved for the treatment of psoriasis in Germany and since then has become the most commonly used systemic therapy in this country. Fumaric acids have been proven to be an effective therapy in patients with psoriasis even though the mechanisms of action are not completely understood. About 50-70% of the patients achieve PASI 75 improvement within four months of treatment and without any long-term toxicity, immunosuppressive effects or increased risk of infection or malignancy. Tolerance is limited by gastrointestinal side effects and flushing of the skin. This article reviews pharmacokinetics, uses, contraindications, dosages and side effects of treatment with FAEs.

  20. Use of fumaric acid esters in psoriasis

    Directory of Open Access Journals (Sweden)

    Roll Antonie

    2007-01-01

    Full Text Available Fumaric acid esters (FAE are chemical compounds derived from the unsaturated dicarbonic acid fumaric acid. The usage of FAEs in treatment of psoriasis was introduced in the late 1950′s. In the 1980s more standardized oral preparations of FAEs were developed containing dimethylfumarate(DMF and salts of monoethylfumarate(MEF as main compounds. In 1994, Fumaderm ® an enteric-coated tablet containing DMF and calcium, magnesium, and zinc salts of MEF was approved for the treatment of psoriasis in Germany and since then has become the most commonly used systemic therapy in this country. Fumaric acids have been proven to be an effective therapy in patients with psoriasis even though the mechanisms of action are not completely understood. About 50-70% of the patients achieve PASI 75 improvement within four months of treatment and without any long-term toxicity, immunosuppressive effects, or increased risk of infection or malignancy. Tolerance is limited by gastrointestinal side effects and flushing of the skin. This article reviews pharmacokinetics, uses, contraindications, dosages, and side effects of treatment with FAEs.

  1. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.

    2016-03-15

    Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

  2. Methods of refining and producing dibasic esters and acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E; Cohen, Steven A; Gildon, Demond L

    2015-04-07

    Methods are provided for refining natural oil feedstocks and producing dibasic esters and/or dibasic acids. The methods comprise reacting a terminal olefin with an internal olefin in the presence of a metathesis catalyst to form a dibasic ester and/or dibasic acid. In certain embodiments, the olefin esters are formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having olefin esters.

  3. In vivo analgesic and anti-inflammatory activities of Rosmarinus officinalis aqueous extracts, rosmarinic acid and its acetyl ester derivative.

    Science.gov (United States)

    Lucarini, Rodrigo; Bernardes, Wagner A; Ferreira, Daniele S; Tozatti, Marcos G; Furtado, Ricardo; Bastos, Jairo K; Pauletti, Patrícia M; Januário, Ana H; Silva, Márcio L Andrade E; Cunha, Wilson R

    2013-09-01

    Despite several pharmacological applications of Rosmarinus officinalis L. (Lamiaceae), studies on its analgesic and anti-inflammatory properties have been scarce. The aim of this work was to use in vivo models to evaluate the analgesic and anti-inflammatory activities of the aqueous extracts obtained from leaves (AEL) and stems (AES) of Rosmarinus officinalis, as well as its isolated compound--rosmarinic acid (RA). We also prepared and assessed the acetyl ester derivative of RA. The analgesic activity was evaluated using abdominal constriction and formalin tests. For the evaluation of the anti-inflammatory effects, carrageenin-induced paw edema in rats were used. The extracts were used at doses of 100, 200 and 400 mg kg⁻¹ compounds were tested at 10, 20 and 40 mg kg⁻¹. Orally administered AEL, AES and RA were not significantly active at any of the doses tested during the abdominal constriction test; the acetyl ester derivative of RA displayed significant analgesic activity. In the carrageenin-induced paw edema assay, the acetyl derivative of RA at all the tested doses produced significant anti-inflammatory effects and reduced the number of paw licks in the second phase of the formalin test. The results suggest that the analgesic effects of the acetyl derivative of RA operate via a peripheral-mediated mechanism. The acetyl ester derivative of RA is potentially applicable as a new lead compound for the management of pain and inflammation.

  4. Assessing human exposure to phthalates, alternative plasticizers and organophosphate esters

    OpenAIRE

    Bui, Tuong Thuy

    2017-01-01

    Phthalate esters (PEs) and organophosphate esters (OPEs) are common indoor pollutants frequently detected in environmental (dust, air), personal (hand wipes, diet) and human matrices (urine, serum etc.). In this thesis, mathematical models were used to establish links between intake and body burden for a comprehensive dataset based on a Norwegian study population. Also, the relative importance of different PE uptake pathways was assessed and discussed. Furthermore, the suitability of human na...

  5. The enantioselective b-keto ester reductions by Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    HASSAN TAJIK

    2006-09-01

    Full Text Available The enantioselective yeast reduction of aromatic b-keto esters, by use of potassium dihydrogen phosphate, calcium phosphate (monobasic, magnesium sulfate and ammonium tartrate (diammonium salt (10:1:1:50 in water at pH 7 as a buffer for 72–120 h with 45–90 % conversion to the corresponding aromatic -hydroxy esters was achieved by means of Saccharomyces cerevisiae.

  6. Long-Acting Diclofenac Ester Prodrugs for Joint Injection

    DEFF Research Database (Denmark)

    Mertz, Nina; Larsen, Susan Weng; Kristensen, Jesper

    2016-01-01

    A prodrug approach for local and sustained diclofenac action after injection into joints based on ester prodrugs having a pH-dependent solubility is presented. Inherent ester prodrug properties influencing the duration of action include their pH-dependent solubility and charge state, as well...... suggest that it is possible to alter and control dissolution and reconversion behavior of the diclofenac prodrugs, thus making the prodrug approach feasible for local and sustained diclofenac action after joint injection....

  7. Methods of refining and producing isomerized fatty acid esters and fatty acids from natural oil feedstocks

    Energy Technology Data Exchange (ETDEWEB)

    Snead, Thomas E.; Cohen, Steven A.; Gildon, Demond L.; Beltran, Leslie V.; Kunz, Linda A.; Pals, Tessa M.; Quinn, Jordan R; Behrends, Jr., Raymond T.; Bernhardt, Randal J.

    2016-07-05

    Methods are provided for refining natural oil feedstocks and producing isomerized esters and acids. The methods comprise providing a C4-C18 unsaturated fatty ester or acid, and isomerizing the fatty acid ester or acid in the presence of heat or an isomerization catalyst to form an isomerized fatty ester or acid. In some embodiments, the methods comprise forming a dibasic ester or dibasic acid prior to the isomerizing step. In certain embodiments, the methods further comprise hydrolyzing the dibasic ester to form a dibasic acid. In certain embodiments, the olefin is formed by reacting the feedstock in the presence of a metathesis catalyst under conditions sufficient to form a metathesized product comprising olefins and esters, separating the olefins from the esters in the metathesized product, and transesterifying the esters in the presence of an alcohol to form a transesterified product having unsaturated esters.

  8. Ester Tuiksoo võitleb viina puhtuse eest / Ester Tuiksoo ; interv. Silja Lättemäe

    Index Scriptorium Estoniae

    Tuiksoo, Ester, 1965-

    2006-01-01

    Põllumajandusminister Ester Tuiksoo lubab Euroopa Liidu piiritusjookide määruse eelnõu arutusel kaitsta seisukohta, et viinaks tuleb pidada üksnes teraviljast või kartulist valmistatud piiritusjooki

  9. ESTIMATION OF HYDROLYSIS RATE CONSTANTS OF CARBOXYLIC ACID ESTER AND PHOSPHATE ESTER COMPOUNDS IN AQUEOUS SYSTEMS FROM MOLECULAR STRUCTURE BY SPARC

    Science.gov (United States)

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid ester and phosphate ester compounds in aqueous non- aqueous and systems strictly from molecular structure. The energy diffe...

  10. A novel one-pot procedure for the stereoselective synthesis of alpha-hydroxy esters from ortho esters.

    Science.gov (United States)

    Breuning, Matthias; Häuser, Tobias; Tanzer, Eva-Maria

    2009-09-17

    A novel one-pot procedure for the stereoselective synthesis of alpha-hydroxy esters from ortho esters was developed. Key steps were multi-heteroatom Cope rearrangements of O-acylated N-hydroxy-l-tert-leucinol-derived oxazoline N-oxides leading to alpha-acyloxy oxazolines and, after methanolysis, to the target molecules in 67-80% yield and 94-98% ee.

  11. Fuel Pellets from Wheat Straw: The Effect of Lignin Glass Transition and Surface Waxes on Pelletizing Properties

    Science.gov (United States)

    Wolfgang Stelte; Craig Clemons; Jens K. Holm; Jesper Ahrenfeldt; Ulrik B. Henriksen; Anand R. Sanadi

    2012-01-01

    The utilization of wheat straw as a renewable energy resource is limited due to its low bulk density. Pelletizing wheat straw into fuel pellets of high density increases its handling properties but is more challenging compared to pelletizing wood biomass. Straw has a lower lignin content and a high concentration of hydrophobic waxes on its outer surface that may limit...

  12. Micromorphology of epicuticular waxes and epistomatal chambers of pine species by electron microscopy and white light scanning interferometry.

    Science.gov (United States)

    Kim, Ki Woo; Lee, In Jung; Kim, Chang Soo; Lee, Don Koo; Park, Eun Woo

    2011-02-01

    High-resolution imaging and quantitative surface analysis of epicuticular waxes and epistomatal chambers of pine species were performed by field emission scanning electron microscopy and white light scanning interferometry. Both juvenile and adult needles were collected from the two-year-old seedlings of Pinus rigida and Pinus densiflora and subjected to surface observations. Epicuticular wax structures developed on the cuticle layer as well as in the epistomatal chambers and appeared to occlude the cavities in the two pine species. The stomata of P. densiflora were characterized by more distinctly raised rings around openings than P. rigida. The most common epicuticular wax structures of the two pine species included tubules with terminal openings and coiled rodlets. Wax platelets were deposited on epistomatal chambers. Either rodlets or tubules seemed to be longer and thicker in P. rigida than those in P. densiflora. White light scanning interferometry revealed quantitative surface profiles, demonstrating more ridged (ca. 4 μm high) stomatal apertures and nearly twofold deeper (ca. 20 μm deep) epistomatal chambers of P. densiflora than those of P. rigida. These results suggest that white light scanning interferometry can be applied to unravel the quantitative surface features of epicuticular sculptures on plant leaves.

  13. Passive vectoring of entomopathogenic fungus Beauveria bassiana among the wax moth Galleria mellonella larvae by the ectoparasitoid Habrobracon hebetor females.

    Science.gov (United States)

    Kryukov, Vadim Yu; Kryukova, Natalia A; Tyurin, Maksim V; Yaroslavtseva, Olga N; Glupov, Viktor V

    2017-03-15

    Females of the ectoparasitoid Habrobracon hebetor attack and envenomate numerous host individuals during oviposition. The vectoring of the entomopathogenic fungus Beauveria bassiana during the adhesion stage by ectoparasitoid females among the wax moth larvae Galleria mellonella was explored under laboratory conditions. Vectoring occurred both from infected parasitoids to wax moth larvae and from infected to healthy wax moth larvae by parasitoids. The efficacy of vectoring in both cases was dose dependent. Parasitoid females were unable to recognize infected larvae in a labyrinth test. In addition, the presence of H. hebetor females significantly (1.5-13 fold) increased the mycoses level in clusters of G. mellonella, with 40% of the larvae infected with fungal conidia. Envenomation by H. hebetor increased conidia germination on the cuticles of the wax moth larvae by 4.4 fold. An enhanced germination rate (2 fold) was registered in the n-hexane epicuticular extract of envenomated larvae compared to that of healthy larvae. Both envenomation and mycoses enhanced the phenoloxidase (PO) activity in the integument of G. mellonella and, in contrast, decreased the encapsulation rate in hemolymphs. We hypothesize that changes in the integument property and inhibition of cellular immunity provide the highest infection efficacy of entomopathogenic fungi with H. hebetor. © 2017 Institute of Zoology, Chinese Academy of Sciences.

  14. Evaluation of extraction methods from paraffin wax embedded tissues for PCR amplification of human and viral DNA

    OpenAIRE

    Chan, P; Chan, D.; To, K; Yu, M.; Cheung, J.; Cheng, A

    2001-01-01

    Aim—To evaluate the efficiency of phenol/chloroform, microwave, and Qiagen spin column based DNA extractions from paraffin wax embedded tissue for use in the polymerase chain reaction (PCR). In addition, to assess the reliability of amplifying a housekeeping gene to indicate successful viral DNA extraction.

  15. The Effect of Prebiotic and Probiotic Feed Supplementation on the Wax Glands of Worker Bees (Apis Mellifera

    Directory of Open Access Journals (Sweden)

    Silvia Pătruică

    2012-10-01

    Full Text Available This paper presents the effects of acidifying substances (lactic acid or acetic acid, Enterobiotics products(Lactobacillus acidophilus LA-14 and Bifidobacterium lactis BI-04 and Enterolactis Plus (Lactobacillus casei onthe wax glands of worker bees. The research was conducted in Timis County, Romania, between March 25 and April20, 2011, on 110 colonies of bees (Apis mellifera carpatica, allocated to 11 experimental treatment groups. Coloniesin the experimental groups were given three weekly feeds of sugar syrup supplemented with acidifying substances(lactic acid or cider vinegar and/or probiotic products (Enterobiotics or Enterolactis Plus. Three weeks after theadministration of the experimental diets, 10 worker bees from each treatment group were sampled for histologicalexamination of their wax glands. Gland development was shown to be influenced by administration of prebioticand/or probiotic supplements. Wax gland cell sizes ranged from 25.1 microns for the control group to between 27.8and 31.8 microns in the group fed with acidifying substances and between 26.9 and 29.2 microns in bees fed withprobiotic products. Bees supplemented with both lactic acid and probiotic product (group LE9 and LE10 showedmean wax cell sizes of 31.8 microns.

  16. Direct investigations of deformation and yield induced structure transitions in polyamide 6 below glass transition temperature with WAXS and SAXS

    DEFF Research Database (Denmark)

    Guo, Huilong; Wang, Jiayi; Zhou, Chengbo

    2015-01-01

    Deformation and yield induced structure transitions of polyamide 6 (PA6) were detected with the combination of the wide- and small-angle X-ray scattering (WAXS and SAXS) at 30 degrees C below glass transition temperature (T-g) of PA6. During deformation, gamma-alpha phase transition was found...

  17. Influence of waxing coupled to 1-methylcyclopropene on compositional changes in early harvested ‘gold’ pineapple for export

    Directory of Open Access Journals (Sweden)

    Francisca Ligia de Castro Machado

    2014-04-01

    Full Text Available This work evaluated the changes in quality in early-harvested ‘Gold’ pineapple after coating with wax and exposure to 1-Methylcycloprepene before or after coating. The storage conditions and the experimental period simulated those of shipping and marketing, assuming that Ceará,Brazil, is the production site andEuropeis the marketplace. Evaluation was performed after harvest, upon removal of the fruit from cold storage, and every three days during room storage. Evaluations included visual quality of the fruit, shell yellowing, mass loss, flesh color, soluble solids, titratable acidity, pH, soluble solids to acid ratio, ascorbic acid, total soluble sugars, reducing sugar, phenolic content, and yellow flavonoids. Low temperature was the key variable for maintaining fruit quality during storage and simulated shipping. Waxing had a remarkable effect on visual quality, delaying yellowing and reducing shell dehydration. Those effects were not enhanced by the application of 1-MCP. 1-MCP treatment resulted in the maintenance of total phenolic content and retention of yellow flavonoids. Fruit flesh became lighter, while yellow color became more vivid during storage. Sugars and pH varied little during storage, while the decline in TA was more intense in waxed fruit. 1-MCP and waxing may be combined to preserve external and internal quality.

  18. Accelerated Thermal Cycling Test of Microencapsulated Paraffin Wax/Polyaniline Made by Simple Preparation Method for Solar Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Mohammad Mehrali

    2013-04-01

    Full Text Available Microencapsulated paraffin wax/polyaniline was prepared using a simple in situ polymerization technique, and its performance characteristics were investigated. Weight losses of samples were determined by Thermal Gravimetry Analysis (TGA. The microencapsulated samples with 23% and 49% paraffin showed less decomposition after 330 °C than with higher percentage of paraffin. These samples were then subjected to a thermal cycling test. Thermal properties of microencapsulated paraffin wax were evaluated by Differential Scanning Calorimeter (DSC. Structure stability and compatibility of core and coating materials were also tested by Fourier transform infrared spectrophotometer (FTIR, and the surface morphology of the samples are shown by Field Emission Scanning Electron Microscopy (FESEM. It has been found that the microencapsulated paraffin waxes show little change in the latent heat of fusion and melting temperature after one thousand thermal recycles. Besides, the chemical characteristics and structural profile remained constant after one thousand thermal cycling tests. Therefore, microencapsulated paraffin wax/polyaniline is a stable material that can be used for thermal energy storage systems.

  19. Leaf surface wax is a source of plant methane formation under UV radiation and in the presence of oxygen.

    Science.gov (United States)

    Bruhn, D; Mikkelsen, T N; Rolsted, M M M; Egsgaard, H; Ambus, P

    2014-03-01

    The terrestrial vegetation is a source of UV radiation-induced aerobic methane (CH4 ) release to the atmosphere. Hitherto pectin, a plant structural component, has been considered as the most likely precursor for this CH4 release. However, most of the leaf pectin is situated below the surface wax layer, and UV transmittance of the cuticle differs among plant species. In some species, the cuticle effectively absorbs and/or reflects UV radiation. Thus, pectin may not necessarily contribute substantially to the UV radiation-induced CH4 emission measured at surface level in all species. Here, we investigated the potential of the leaf surface wax itself as a source of UV radiation-induced leaf aerobic CH4 formation. Isolated leaf surface wax emitted CH4 at substantial rates in response to UV radiation. This discovery has implications for how the phenomenon should be scaled to global levels. In relation to this, we demonstrated that the UV radiation-induced CH4 emission is independent of leaf area index above unity. Further, we observed that the presence of O2 in the atmosphere was necessary for achieving the highest rates of CH4 emission. Methane formation from leaf surface wax is supposedly a two-step process initiated by a photolytic rearrangement reaction of the major component followed by an α-cleavage of the generated ketone. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Over-Expression of SlSHN1 Gene Improves Drought Tolerance by Increasing Cuticular Wax Accumulation in Tomato

    Directory of Open Access Journals (Sweden)

    Ayed M. Al-Abdallat

    2014-10-01

    Full Text Available Increasing cuticular wax accumulation in plants has been associated with improving drought tolerance in plants. In this study, a cDNA clone encoding the SlSHN1 transcription factor, the closest ortholog to WIN/SHN1 gene in Arabidopsis, was isolated from tomato plant. Expression analysis of SlSHN1 indicated that it is induced in response to drought conditions. The over-expression of SlSHN1 in tomato under the control of the constitutive CaMV 35S promoter produced plants that showed mild growth retardation phenotype with shiny and dark green leaves. Scanning electron microscopy showed that the over-expression of SlSHN1 in tomato resulted in higher cuticular wax deposition on leaf epidermial tissue when compared to non-transformed plants. Expression analysis in transgenic lines over-expressing SlSHN1 indicated that several wax-related synthesis genes were induced. Transgenic tomato plants over-expressing SlSHN1 showed higher drought tolerance when compared with wild type plants; this was reflected in delayed wilting of transgenic lines, improved water status and reduced water loss rate when compared with wild type plants. In conclusion, the SlSHN1 gene can modulate wax accumulation and could be utilized to enhance drought tolerance in tomato plant.