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Sample records for euphorbia royleana latex

  1. Antioxidant, antimicrobial, antitumor, and cytotoxic activities of an important medicinal plant (Euphorbia royleana from Pakistan

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    Aisha Ashraf

    2015-03-01

    Full Text Available The aim of present study was to evaluate antioxidant, antimicrobial, and antitumor activities of methanol, hexane, and aqueous extracts of fresh Euphorbia royleana. Total phenolic and flavonoid contents were estimated as gallic acid and querectin equivalents, respectively. Antioxidant activity was assessed by scavenging of free 2,2′- diphenyl-1-picrylhydrazyl radicals and reduction of ferric ions, and it was observed that inhibition values increase linearly with increase in concentration of extract. The results of ferric reducing antioxidant power assay showed that hexane extract has maximum ferric reducing power (12.70 ± 0.49 mg gallic acid equivalents/g of plant extract. Maximum phenolic (47.47 ± 0.71 μg gallic acid equivalents/mg of plant extract and flavonoid (63.68 ± 0.43 μg querectin equivalents/mg of plant extract contents were also found in the hexane extract. Furthermore, we examined antimicrobial activity of the three extracts (methanol, hexane, aqueous against a panel of microorganisms (Escherichia coli, Bacillus subtillis, Pasteurella multocida, Aspergillus niger, and Fusarium solani by disc-diffusion assay, and found the hexane extract to be the best antimicrobial agent. Hexane extract was also observed as to be most effective in a potato disc assay. As hexane extract showed potent activity in all the investigated assays, it was targeted for cytotoxic assessment. Maximum cytotoxicity (61.66% by hexane extract was found at 800 μg/mL. It is concluded that investigated extracts have potential for isolation of antioxidant and antimicrobial compounds for the pharmaceutical industry.

  2. Triterpenoid biosynthesis in Euphorbia lathyris latex

    International Nuclear Information System (INIS)

    Hawkins, D.R.

    1987-11-01

    The structures of triterpenols, not previously been known, from Euphorbia lathyris latex are reported. A method for quantifying very small amounts of these compounds was developed. Concerning the biochemistry of the latex, no exogenous cofactors were required for the biosynthesis and the addition of compounds such as NADPAH and ATP do not stimulate the biosynthesis. The addition of DTE or a similar anti-oxidant was found to help reduce the oxidation of the latex, thus increasing the length of time that the latex remains active. The requirement of a divalent cation and the preference for Mn in the pellet was observed. The effect of several inhibitors on the biosynthesis of the triterpenoids was examined. Mevinolin was found to inhibit the biosynthesis of the triterpenoids from acetate, but not mevalonate. A dixon plot of the inhibition of acetate incorporation showed an I 50 concentration of 3.2 μM. Fenpropimorph was found to have little or no effect on the biosynthesis. Tridemorph was found to inhibit the biosynthesis of all of the triterpenoids with an I 50 of 4 μM. It was also observed that the cyclopropyl containing triterpenols, cycloartenol and 24-methylenecycloartenol were inhibited much more strongly than those containing an 8-9 double bond, lanosterol and 24-methylenelanosterol. The evidence indicates, but does not definetely prove, that lanosterol and 24-methylenelanosterol are not made from cycloartenol and 24-methylenecycloartenol via a ring-opening enzyme such as cycloeucalenol-obtusifoliol isomerase. The possibilty that cycloartenol is made via lanosterol was investigated by synthesizing 4-R-4- 3 H-mevalonic acid and incubating latex with a mixture of this and 14 C-mevalonic acid. From the 3 H/ 14 C ratio it was shown that cycloartenol and 24-methylenecycloartenol are not made via an intermediate containing as 8-9 double bond. 88 refs., 15 figs., 30 tabs

  3. Triterpenoid biosynthesis in Euphorbia lathyris latex

    Energy Technology Data Exchange (ETDEWEB)

    Hawkins, D.R.

    1987-11-01

    The structures of triterpenols, not previously been known, from Euphorbia lathyris latex are reported. A method for quantifying very small amounts of these compounds was developed. Concerning the biochemistry of the latex, no exogenous cofactors were required for the biosynthesis and the addition of compounds such as NADPAH and ATP do not stimulate the biosynthesis. The addition of DTE or a similar anti-oxidant was found to help reduce the oxidation of the latex, thus increasing the length of time that the latex remains active. The requirement of a divalent cation and the preference for Mn in the pellet was observed. The effect of several inhibitors on the biosynthesis of the triterpenoids was examined. Mevinolin was found to inhibit the biosynthesis of the triterpenoids from acetate, but not mevalonate. A dixon plot of the inhibition of acetate incorporation showed an I/sub 50/ concentration of 3.2 ..mu..M. Fenpropimorph was found to have little or no effect on the biosynthesis. Tridemorph was found to inhibit the biosynthesis of all of the triterpenoids with an I/sub 50/ of 4 ..mu..M. It was also observed that the cyclopropyl containing triterpenols, cycloartenol and 24-methylenecycloartenol were inhibited much more strongly than those containing an 8-9 double bond, lanosterol and 24-methylenelanosterol. The evidence indicates, but does not definetely prove, that lanosterol and 24-methylenelanosterol are not made from cycloartenol and 24-methylenecycloartenol via a ring-opening enzyme such as cycloeucalenol-obtusifoliol isomerase. The possibilty that cycloartenol is made via lanosterol was investigated by synthesizing 4-R-4-/sup 3/H-mevalonic acid and incubating latex with a mixture of this and /sup 14/C-mevalonic acid. From the /sup 3/H//sup 14/C ratio it was shown that cycloartenol and 24-methylenecycloartenol are not made via an intermediate containing as 8-9 double bond. 88 refs., 15 figs., 30 tabs.

  4. Identification and characterization of Euphorbia nivulia latex proteins.

    Science.gov (United States)

    Badgujar, Shamkant B; Mahajan, Raghunath T

    2014-03-01

    The protein profile of latex of Euphorbia nivulia Buch.-Ham. is established. Three new proteins viz., Nivulian-I, II and III have been purified to homogeneity from the latex. The relative molecular masses of Nivulian-I, II and III are 31,486.985, 43,670.846 and 52,803.470 Da respectively. Nivulian-I is a simple type of protein while Nivulian-II and III are glycoproteins. Peptide mass fingerprint analysis revealed peptides of these proteins match with Tubulin alpha-1 chain of Eleusine indica, Maturase K of Banksia quercifolia and hypothetical protein of Zea mays respectively. Tryptic digestion profile of Nivulian-I, II and III, infer the exclusive nature of latex origin proteins and may be new and are additive molecules in the dictionaries of phytoproteins or botany. This is the first of its kind, regarding characterization and validation of Nivulian-I, II and III with respect to peptide sequencing. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. LOL2 and LOL5 loci control latex production by laticifer cells in Euphorbia lathyris.

    Science.gov (United States)

    Castelblanque, Lourdes; Balaguer, Begoña; Marti, Cristina; Orozco, Marianela; Vera, Pablo

    2018-06-07

    Laticifers are specialized plant cells capable of indefinite elongation that ramify extensively and are responsible for latex biosynthesis and accumulation. However, the mechanisms underlying laticifer cell differentiation, growth and production of latex remain largely unknown. In a search for mutants showing enhanced accumulation of latex we identified two LOT OF LATEX (LOL) loci in Euphorbia lathyris. lol2 and lol5 mutants show enhanced production of latex contained within laticifer cells. The recessive lol2 mutant carries increased biosynthesis of the plant hormone jasmonoyl-isoleucine (JA-Ile) and therefore establishes a genetic link between jasmonic acid (JA) signaling and latex production in laticifers. Instead, heightened production of latex in lol5 plants obeys to enhanced proliferation of laticifer cells. Phylogenetic analysis of laticifer-expressed genes in E. lathyris and in two other latex-bearing species, Euphorbia corallioides and Euphorbia palustris, allowed the identification of canonical JA responsive elements present in the gene promoter regions of laticifer marker genes. Moreover, we identified that the hormone JA functions not as a morphogen for laticifer differentiation but as a trigger for the fill out of laticifers with latex and the associated triterpenoids. The identification of LOL loci represents a further step towards the understanding of mechanisms controlling latex production in laticifer cells. No claim to original US Government works New Phytologist © 2018 New Phytologist Trust.

  6. Comparative study on plant latex particles and latex coagulation in Ficus benjamina, Campanula glomerata and three Euphorbia species.

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    Georg Bauer

    Full Text Available Among latex-producing plants, mainly the latex of Hevea brasiliensis has been studied in detail so far, while comprehensive comparative studies of latex coagulation mechanisms among the more than 20,000 latex-bearing plant species are lacking. In order to give new insights into the potential variety of coagulation mechanisms, the untreated natural latices of five latex-bearing plants from the families Euphorbiaceae, Moraceae and Campanulaceae were visualised using Cryo-SEM and their particle size compared using the laser diffraction method. Additionally, the laticifers of these plants species were examined in planta via Cryo-SEM. Similar latex particle sizes and shape were found in Ficus benjamina and Hevea brasiliensis. Hence, and due to other similarities, we hypothesize comparable, mainly chemical, coagulation mechanisms in these two species, whereas a physical coagulation mechanism is proposed for the latex of Euphorbia spp. The latter mechanism is based on the huge amount of densely packed particles that after evaporation of water build a large surface area, which accelerates the coagulation procedure.

  7. Molluscicidal effect of Euphorbia umbellata (Pax Bruyns latex on Biomphalaria glabrata, Schistosoma mansoni host snail

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    Luciana Patrícia Lima Alves Pereira

    2017-12-01

    Full Text Available ABSTRACT Euphorbia umbellata (Pax Bruyns is an easily cultivated shrub, with occurrence in the tropical regions of the American and African continents. Chemical studies have revealed that the latex of this plant is rich in terpene compounds, which are highly toxic to snails Biomphalaria glabrata (Basommatophora: Planorbidae. The aim of this study was to evaluate the chemical composition and molluscicidal activity of the latex produced by E. umbellata, as well as the safety of its application in aquatic environments. The concentration of latex that killed 90% of the exposed snails after 24 h exposure (LC90 was 3.69 mg/L. Toxicity bioassays using Danio rerio (zebrafish revealed that these animals were less susceptible to latex than planorbids. However, it is important to perform other toxicity tests to ensure the feasibility of using latex to control populations of mollusks that contribute to schistosomiasis transmission. A phytochemical screening performed with the E. umbellata latex identified the triterpenoid and coumarin class. Further studies are warranted to isolate, identify, and test the active compounds of E. umbellata latex in B. glabrata.

  8. Euphorbia latex: a possible source of hydrocarbons and rubber

    Energy Technology Data Exchange (ETDEWEB)

    Viaud, P; Teisseire, D

    1975-01-01

    Illustrated descriptions are given of 36 plants of potential economic value in underdeveloped tropical countries, classified by use. The plants are either wild or cultivated on a fairly local scale. Accounts of limitations and special requirements and lists of references, research contacts and sources of germ plasm are included for each species. The following tree and shrub species are included: Cnidoscolus aconitifolius, C. chayamansa and hearts of several edible palm species including Euterpe edulis (vegetables); Durio species, Garcinia mangostana, Solanum quitoense, Bactris gaspiaes, Citrus grandis, Annona muricata and Pourouma cecropiaefolia (fruits); Orbignya martiana, Caryocar species, Jessenia polycarpa and Simmondsia chinensis (oil seeds); Acacia albida, Brosimum alicastrum, Cassia sturtii, Atriplex species and Prosopis tamarungo (forage (browse)); Mauritia flexuosa (fruit, wood, etc.); Euphorbia antisyphilitica (wax); and Parthenium argentatum (rubber).

  9. Cytotoxicity of latex and pharmacobotanical study of leaves and stem of Euphorbia umbellata (Janaúba

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    Lívia E.C. Luz

    Full Text Available AbstractIn southern Brazil, the bottled latex of Synadenium grantii Hook f., Euphorbiaceae, is popularly used as a treatment of all types of cancer. Similarly, Synadenium umbellatum Pax. is used in the central western region of Brazil for the same purpose and in the same manner of use. Both plants are popularly known as janaúba or leitosinha. The objectives of this study were to use pharmacobotanical analysis to verify whether these two species, which are considered to be distinct, are actually the same to determine anatomical markers; to assist in the identification and differentiation of other Euphorbia; and to evaluate the cytotoxic activity of the latex in relation to HeLa and HRT-18 cells. Leaves and stems of the species were collected in Goiânia and Ponta Grossa and were investigated using scanning electron microscopy and optical microscopy techniques. The latex was also collected and analyzed in relation to its cytotoxic effect by employing MTT and NR techniques. The pharmacobotanical study of the specimens in both localities showed that they were the same species, namely Euphorbia umbellata (Pax Bruyns, which is the scientific nomenclature accepted and confirmed by an expert taxonomist who specializes in Euphorbia. The pharmacobotanical characteristics highlighted in this study can assist in the identification of the taxon and contribute to the control of the quality of this plant drug. The evaluation of the latex in relation to HRT-18 cells demonstrated action after 48 h of experiment. In contrast, in relation to HeLa cells its induced cytotoxicity in all times and a dose-dependent manner. The IC50 values (72 h observed were 252.58 ± 18.51 µg/ml and 263.42 ± 15.92 µg/ml to MTT experiment and 250.18 ± 19.48 µg/ml and 430.56 ± 19.71 µg/ml to NR experiment for the HeLa and HRT-18 cells, respectively.

  10. Facile synthesis of silver nanoparticles using Euphorbia antiquorum L. latex extract and evaluation of their biomedical perspectives as anticancer agents

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    Chandrasekaran Rajkuberan

    2017-12-01

    Full Text Available This study reveals the rapid biosynthesis of silver nanoparticles (EAAgNPs using aqueous latex extract of Euphorbia antiquorum L as a potential bioreductant. Synthesized EAAgNPs generate the surface plasmonic resonance peak at 438 nm in UV–Vis spectrophotometer. Size and shape of EAAgNPs were further characterized through transmission electron microscope (TEM which shows well-dispersed spherical nanoparticles with size ranging from 10 to 50 nm. Energy dispersive X-ray spectroscopic analysis (EDAX confirms the presence of silver (Ag as the major constituent element. X-ray diffraction (XRD pattern of EAAgNPs corresponding to (111, (200, (220 and (311 planes, reveals that the generated nanoparticles were face centered cubic crystalline in nature. Interestingly, fourier-transform infrared spectroscopy (FTIR analysis shows the major role of active phenolic constituents in reduction and stabilization of EAAgNPs. Phyto-fabricated EAAgNPs exhibits significant antimicrobial and larvicidal activity against bacterial human pathogens as well as disease transmitting blood sucking parasites such as Culex quinquefasciatus and Aedes aegypti (IIIrd instar larvae. On the other hand, in vitro cytotoxicity assessment of bioformulated EAAgNPs has shown potential anticancer activity against human cervical carcinoma cells (HeLa. The preliminary biochemical (MTT assay and microscopic studies depict that the synthesized EAAgNPs at minimal dosage (IC50 = 28 μg triggers cellular toxicity response. Hence, the EAAgNPs can be considered as an environmentally benign and non-toxic nanobiomaterial for biomedical applications. Keywords: Crystal structure, Euphorbia antiquorum L., Silver nanoparticles, Anticancer, Human pathogens

  11. Comparative study of the conformational lock, dissociative thermal inactivation and stability of euphorbia latex and lentil seedling amine oxidases.

    Science.gov (United States)

    Amani, M; Moosavi-Movahedi, A A; Floris, G; Longu, S; Mura, A; Moosavi-Nejad, S Z; Saboury, A A; Ahmad, F

    2005-04-01

    The thermal stability of copper/quinone containing amine oxidases from Euphorbia characias latex (ELAO) and lentil seedlings (LSAO) was measured in 100 mM potassium phosphate buffer (pH 7.0) following changes in absorbance at 292 nm. ELAO was shown to be about 10 degrees C more stable than LSAO. The dissociative thermal inactivation of ELAO was studied using putrescine as substrate at different temperatures in the range 47-70 degrees C, and a "conformational lock" was developed using the theory pertaining to oligomeric enzyme. Moreover ELAO was shown to be more stable towards denaturants than LSAO, as confirmed by dodecyl trimethylammonium bromide denaturation curves. A comparison of the numbers of contact sites in inter-subunits of ELAO relative to LSAO led us to conclude that the higher stability of ELAO to temperature and towards denaturants was due to the presence of larger number of contact sites in the conformational lock of the enzyme. This study also gives a putative common mechanism for thermal inactivation of amine oxidases and explains the importance of C-terminal conserved amino acids residues in this class of enzymes.

  12. Green mediated synthesis and characterization of ZnO nanoparticles using Euphorbia Jatropa latex as reducing agent

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    M.S. Geetha

    2016-09-01

    Full Text Available Presently the progress of green chemistry in the synthesis of nanoparticles with the use of plants has engrossed a great attention. This study reports the synthesis of ZnO using latex of Euphorbia Jatropa as reducing agent. As prepared product was characterized by powder X-ray diffractometer (PXRD, Fourier transform infra-red spectroscopy (FTIR, scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS, transmission electron microscopy (TEM, X-ray photo electron spectroscopy (XPS, Rietveld refinement, UV–Visible spectroscopy and photoluminescence (PL. The concentration of plant latex plays an important role in controlling the size of the particle and its morphology. PXRD graphs showed the well crystallisation of the particles. The average particle size was calculated using Scherrer equation and advanced Williamson Hall (WH plots. The average particle size was around 15 nm. This result was also supported by SEM and TEM analyses. FTIR shows the characteristic peak of ZnO at 435 cm−1. SEM and TEM micrographs show that the particles were almost hexagonal in nature. EDS of SEM analysis confirmed that the elements are only Zn and O. EDS confirmed purity of ZnO. Atomic states were confirmed by XPS results. Crystal parameters were determined using Rietveld refinement. From UV–Visible spectra average energy gap was calculated which is ∼3.63 eV. PL studies showed UV emission peak at 392 nm and broad band visible emission centred in the range 500–600 nm. The Commission International de I'Eclairage and colour correlated temperature coordinates were estimated for ZnO prepared using 2 ml, 4 ml and 6 ml Jatropa latex. The results indicate that the phosphor may be suitable for white light emitting diode (WLED. The study fruitfully reveals simple, fast, economical and eco friendly method of synthesis of multifunctional ZnO nanoparticles (Nps.

  13. A study on effect of ATH on Euphorbia coagulum modified polyester banana fiber composite

    Science.gov (United States)

    Kumari, Sanju; Rai, Bhuvneshwar; Kumar, Gulshan

    2018-02-01

    Fiber reinforced polymer composites are used for building and structural applications due to their high strength. In conventional composites both the binder and the reinforcing fibers are synthetic or either one of the material is natural. In the present study coagulum of Euphorbia royleana has been used for replacing polyester resinas binder in polyester banana composite. Euphorbia coagulum (driedlatex) is rich in resinous mass (60-80%), which are terpenes and polyisoprene (10-20%). Effect of varying percentage of coagulum content on various physico-mechanical properties of polyester-banana composites has been studied. Since banana fiber is sensitive to water due to presence of polar group, banana composite undergoes delamination and deterioration under humid condition. Alkali treated banana fiber along with coagulum content has improved overall mechanical properties and reduction in water absorption. The best physico-mechanical properties have been achieved on replacing 40% of polyester resin by coagulum. An increase of 50% in bending strength, 30% bending modulus and 45% impact strength as well as 68% decrease in water absorption was observed. Incorporation of 20% ATH as flame retardant in coagulum modified banana polyester composite enhanced limiting oxygen index from 20.6 to 26.8% and smoke density reduced up to 40%. This study presents the possibility of utilization of renewable materials for environmental friendly composite development as well as to find out alternative feedstock for petroleum products. Developed Euphorbia latex modified banana polyester composites can have potential utility in hardboard, partition panel, plywood and automotive etc.

  14. Alterations in carbohydrates and the protein metabolism of the harmful freshwater vector snail Lymnaea acuminata induced by the Euphorbia tirucalli latex extract.

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    Tiwari, Sudhanshu; Singh, A

    2005-11-01

    To know the short- as well as long-term effect of aqueous latex extracts of Euphorbia tirucalli on carbohydrate and protein metabolism, the snail Lymnaea acuminata was exposed to sublethal doses of 0.37 and 0.55 mg/L for a 24-h and 0.20 and 0.31 mg/L for a 96-h exposure period. Significant (P<0.05) alterations in the glycogen, pyruvate, lactate, total protein, and free amino acid level, as well as in the activity of enzyme lactic dehydrogenase, succinic dehydrogenase, cytochrome oxidase, protease, aspartate aminotransaminase, and alanine aminotransaminase were observed in the nervous, hepatopancreatic, and ovotestis tissues of the freshwater vector snail L. acuminata exposed to sublethal doses of E. tirucalli latex extract. The alterations in all biochemical parameters were significantly (P<0.05) time and dose dependent. After the 7th day of the withdrawal of treatment, there was significant (P<0.05) recovery in glycogen, pyruvate, lactate, total protein, and the free amino acid level and in the activity of the lactic dehydrogenase, succinic dehydrogenase, cytochrome oxidase, protease, aspartate aminotransaminase and alanine aminotransaminase enzymes in all three of the studied tissues of the snail, which supports the view that the plant product is safe for use as a molluscicide for the control of harmful freshwater vector snails in the aquatic environment.

  15. In vitro propagation of lnula royleana DC

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    Anna Stojakowska

    2011-01-01

    Full Text Available A micropropagation method, through axillary shoot proliferation, was elaborated for Inula royleana DC. (Asteraceae, a medicinal plant native of Himalaya. Primary explants (cotyledonary node explants and secondary explants (node explants of in vitro regenerated shoots of the plant, inoculated on MS medium supplemented with 0.1 μM NAA and 5.0 μM kinetin, regenerated 3.4 ± 1.2 and 5.1 ± 1.9 axillary shoots per explant, respectively. The regenerated shoots were easily rooting and adapting to growth in soil.

  16. Evaluation of temporal, seasonal and geographic stability of the molluscicidal property of Euphorbia splendens latex Avaliação da estabilidade temporal, estacional e geográfica da ação moluscicida do latex da Euphorbia splendens

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    Virginia Torres Schall

    1992-06-01

    Full Text Available Laboratory tests with aqueous solutions of Euphorbia splendens var. hislopii latex have demonstrated seasonal stability of the molluscicidal principle, with LD90 values of 1.14 ppm (spring, 1.02 ppm (fall, 1.09 ppm (winter, and 1.07 ppm (summer that have been determined against Biomphalaria tenagophila in the field. Assays on latex collected in Belo Horizonte and Recife yielded LD90 values similar to those obtained with the reference substance collected in Rio de Janeiro (Ilha do Governador, demonstrating geographic stability of the molluscicidal effect. The molluscicidal action of aqueous dilutions of the latex in natura, centrifuged (precipitate and lyophilized, was stable for up to 124 days at room temperature (in natura and for up to 736 days in a common refrigerator at 10 to 12ºC (lyophilized product. A 5.0 ppm solution is 100% lethal for snails up to 13 days after preparation, the effect being gradually lost to almost total inactivity by the 30th day. This observation indicated that the active principle is instable. These properties together with the wide distribution of the plant, its resistance and adaptation to the tropical climate, its easy cultivation and the easy obtention of latex and preparation of the molluscicidal solution, make this a promising material for large-scale use in the control of schistosomiasisTestes de laboratório com soluções aquosas do látex da Euphorbia splendens var. hislopii demonstraram uma estabilidade estacional da atividade moluscicida do produto coletado na Ilha do Governador - RJ, encontrando-se as seguintes DL90: 1,14 ppm (primavera; 1,02 ppm (outono; 1,09 ppm (inverno e 1,07 ppm (verão sobre Biomphalaria tenagophila de campo. Ensaios com o látex da planta coletado em Belo Horizonte e Recife, identificaram DL90 semelhantes aos da substância de referência coletada no Rio, demonstrando uma estabilidade geográfica do efeito moluscicida. Usando diluições aquosas do latex in natura, centrifugado

  17. Preliminary results on the ichthyocidal properties of Euphorbia ...

    African Journals Online (AJOL)

    Euphorbiaceae). Mathew J Ross, Gert J Steyn. Abstract. Euphorbia ingens belongs to the family Euphorbiaceae, which includes a variety of latex-producing plants, the majority of them having ichthyocidal properties (Coates-Palgrave 2000). Tests to ...

  18. Global medicinal uses of Euphorbia L. (Euphorbiaceae)

    DEFF Research Database (Denmark)

    Ernst, Madeleine; Grace, Olwen M; Saslis Lagoudakis, Haris

    2015-01-01

    in Australia, topical application of latex of Euphorbia peplus L. is used as a home treatment for skin cancer and actinic keratosis. Its use in Australian folk medicine has inspired the release of the drug Picato ® (ingenol mebutate), and further fostered interest in natural products and medicinal uses...

  19. Chronic toxicological effects of ultradiluted solutions of Aveloz (Euphorbia tirucalli Lineu) on healthy mice: a preliminary study Efeitos toxicológicos crônicos de altas diluições de Aveloz (Euphorbia tirucalli L.) em camundongos sadios: estudo preliminar. Efectos toxicológicos crónicos de altas diluciones de Euphorbia tirucalli en ratones sanos: estudio preliminar.

    OpenAIRE

    Morgana Castelo Branco; Ricardo Kuster; Alexandre dos Santos Pyrrho; Paulo Eduardo Mansur Hobaica; Gleyce Moreno Barbosa; Nelson Gomes; Carolina Lessa Aquino; Elaine Daudt; Teresa Gomes; Cristiane Pereira; Fernanda Sales; Marcia CBN Varricchio; Carla Holandino

    2008-01-01

    The latex extracted from Euphorbia tirucalli, a plant popularly known as Aveloz, is used in complementary medicine to induce tumor regression. However, as this latex has toxic effects when administered orally in ponderal doses, the present study was designed to assess the effects of high dilutions in healthy mice over a period of 18 weeks. The Aveloz latex-high diluted solutions (latex-HD) were obtained through the interaction of two processes: 1:100 dilution in mass and succussion, using et...

  20. Acetylcholinesterase Inhibitory and Antioxidant Properties of Euphorbiacharacias Latex

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    Francesca Pintus

    2013-03-01

    Full Text Available The aim of the present study was to evaluate the acetylcholinesterase inhibitory capacity and the antioxidant properties of extracts of Euphorbia characias latex, a Mediterranean shrub. We performed a new extraction method involving the use of the trichloroacetic acid. The extract showed high antioxidant activity, was rich in total polyphenolic and flavonoid content and exhibited substantial inhibition of acetylcholinesterase activity.

  1. Practical Latex

    CERN Document Server

    Grätzer, George

    2014-01-01

    Accessible at 200+ pages to all who want to learn the practical usages of LaTeX Avoids technical subjects like font usage Friendly and easy to read, with many examples included Extra source materials include sample LaTeX files and suggestions for further reading

  2. Effect of Organic Fertilizers and Plant Density on Qualititative Characteristics of Balangu (Lallenamntia royleana Benth.

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    A Roohi Nogh

    2017-10-01

    Full Text Available Introduction Recently, the impact of chemical farming and the negative consequences on the environment and human health are on rise in Iran. Organic farming is gaining attention and increasing globally because it is eco-friendly, safe and has benefits for human health. The use of organic fertilizers in agriculture improves soil structure. Plant spacing and fertilizer applications have significant influence on the growth and yield in crop production. Optimum plant spacing ensures the proper use of land, as well as growth and nutrition in plants. Balangu (Lallemantia royleana Benth. is a medicinal plant from Lamiaceae family, containing essential oils and mucilage. The most important feature of this plant is the mucilage of the seeds. The seeds are a good source of fiber, oil and protein, and have medicinal and nutritional properties. Using the appropriate plant density and environmental friendly methods like organic fertilizers can improve the quality and quantity of medicinal plants production. Materials and Methods In order to study the effect of organic fertilizers and plant density on the qualitative characteristics of Balangu (Lallemantia royleana Benth. as a medicinal plant, an experiment was conducted at the Research Station of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during the growing season of 2011-2012. Soil samples were collected from the 15 cm depth of each experimental plots for laboratory analysis. This experiment was carried out as factorial layout based on randomized complete block design with three replications. Treatments were included five levels of fertilizer (cow manure, sheep manure, chicken manure, municipal solid waste compost and control and three levels of plant density (20, 30 and 40 plant m-2. The studied traits were included amount of mucilage, swelling factor, swelling per gram mucilage, mucilage and seed yield. Data were analyzed with SAS software. The F test was used to test the significance

  3. Terpenoid biosynthesis in Euphorbia lathyris and Copaifera spp

    International Nuclear Information System (INIS)

    Skrukrud, C.L.

    1987-07-01

    Biosynthesis of triterpenoids by isolated latex of Euphorbia lathyris was investigated. The rate of in vitro incorporation of mevalonic acid into triterpenoids was thirty times greater than acetate incorporation indicating that the rate-limiting step in the pathway occurs prior to mevalonate. Both HMG-CoA reductase (EC 1.1.1.34) and HMG-CoA lyase (EC 4.1.3.4) activities were detected in isolated latex. HMG-CoA reductase was localized to a membrane-bound fraction of a 5000g pellet of latex. The rate of conversion of HMG-CoA to mevalonate by this enzyme is comparable to the overall rate of acetate incorporation into the triterpenoids suggesting that this enzyme is rate-determining in the biosynthesis of triterpenoids in E. lathyris latex. HMG-CoA reductase of E. lathyris vegetative tissue was localized to the membrane-bound portion of a particulate fraction (18,000g), and was solubilized by treatment with 2% polyoxyethylene ether W-1. Differences in the optimal pH for activity of HMG-CoA reductase from the latex and vegetative tissue suggest that isozymes of the enzyme may be present in the two tissue types. Studies of the incorporation of various precursors into leaf discs and cuttings taken from Copaifera spp. show differences in the rate of incorporation into Copaifera sesquiterpenes suggesting that the site of sesquiterpene biosynthesis may differ in its accessibility to the different substrates and/or reflecting the metabolic controls on carbon allocation to the terpenes. Mevalonate incorporation by Copaifera langsdorfii cuttings into sesquiterpenes was a hundred-fold greater than either acetate or glucose incorporation, however, its incorporation into squalene and triterpenoids was also a hundred-fold greater than the incorporation into sesquiterpenes. 119 refs., 58 figs., 16 tabs

  4. Terpenoid biosynthesis in Euphorbia lathyris and Copaifera spp

    Energy Technology Data Exchange (ETDEWEB)

    Skrukrud, C.L.

    1987-07-01

    Biosynthesis of triterpenoids by isolated latex of Euphorbia lathyris was investigated. The rate of in vitro incorporation of mevalonic acid into triterpenoids was thirty times greater than acetate incorporation indicating that the rate-limiting step in the pathway occurs prior to mevalonate. Both HMG-CoA reductase (EC 1.1.1.34) and HMG-CoA lyase (EC 4.1.3.4) activities were detected in isolated latex. HMG-CoA reductase was localized to a membrane-bound fraction of a 5000g pellet of latex. The rate of conversion of HMG-CoA to mevalonate by this enzyme is comparable to the overall rate of acetate incorporation into the triterpenoids suggesting that this enzyme is rate-determining in the biosynthesis of triterpenoids in E. lathyris latex. HMG-CoA reductase of E. lathyris vegetative tissue was localized to the membrane-bound portion of a particulate fraction (18,000g), and was solubilized by treatment with 2% polyoxyethylene ether W-1. Differences in the optimal pH for activity of HMG-CoA reductase from the latex and vegetative tissue suggest that isozymes of the enzyme may be present in the two tissue types. Studies of the incorporation of various precursors into leaf discs and cuttings taken from Copaifera spp. show differences in the rate of incorporation into Copaifera sesquiterpenes suggesting that the site of sesquiterpene biosynthesis may differ in its accessibility to the different substrates and/or reflecting the metabolic controls on carbon allocation to the terpenes. Mevalonate incorporation by Copaifera langsdorfii cuttings into sesquiterpenes was a hundred-fold greater than either acetate or glucose incorporation, however, its incorporation into squalene and triterpenoids was also a hundred-fold greater than the incorporation into sesquiterpenes. 119 refs., 58 figs., 16 tabs.

  5. EUPHORBIA SINCLAIRIANA, AN OLDER NAME FOR THE WIDESPREAD EUPHORBIA ELATA

    Directory of Open Access Journals (Sweden)

    BERNAL RODRIGO

    2006-12-01

    Full Text Available A comparison of collections of Euphorbia elata from accross its range withspecimens of E. sinclairiana from its only known locality, the island of Gorgona,off the Pacific coast of Colombia, shows that the two entities are better treated asconspecific, under the older name E. sinclairiana.

  6. Structural characterization of rubber from jackfruit and euphorbia as a model of natural rubber.

    Science.gov (United States)

    Mekkriengkrai, Dararat; Ute, Koiichi; Swiezewska, Ewa; Chojnacki, Tadeusz; Tanaka, Yasuyuki; Sakdapipanich, Jitladda T

    2004-01-01

    A structural study of low molecular weight rubbers from Jackfruit (Artocarpus heterophyllus) and Painted spurge (Euphorbia heterophylla) was carried out as model compounds of natural rubber from Hevea brasiliensis. The rubber content of latex from Jackfruit was 0.4-0.7%, which is very low compared with that of 30-35% in the latex from Hevea tree. The rubber from Jackfruit latex was low molecular weight with narrow unimodal molecular weight distribution (MWD), whereas that obtained from E. heterophylla showed very broad MWD. The 1H and 13C NMR analyses showed that Jackfruit rubber consists of a dimethylallyl group and two trans-isoprene units connected to a long sequence of cis-isoprene units. The alpha-terminal group of Jackfruit rubber was presumed to be composed of a phosphate group based on the presence of 1H NMR signal at 4.08 ppm corresponding to the terminal =CH-CH2OP group.

  7. An evolutionary perspective on drug discovery in the plant genus Euphorbia L. (Euphorbiaceae)

    DEFF Research Database (Denmark)

    Ernst, Madeleine

    herbivory and physical stresses or to attract pollinators. Consequently, specializedmetabolites, as well as plants used in traditional medicine, are not randomly distributed across phylogenetictrees. Evolutionary approaches to plant-based drug discovery suggest that this informationcan be used to guide...... healthcarethreats, urge for systematic and time-efficient approaches in finding new drug candidates. Manydrugs are derived from plant specialized metabolites, chemical compounds, which are synthesizedby the plants in response to evolutionary adaptation to environmental and ecological factors, for example,to combat...... evolution and diversification. Also, Euphorbia species producean often chemically highly diverse latex exhibiting an exceptional number of biological activities withpharmaceutical interest. In this PhD project, the genus Euphorbia was chosen as a model group forstudying evolutionary approaches to plant...

  8. Comparative Transcriptome Analysis Identifies Putative Genes Involved in Steroid Biosynthesis in Euphorbia tirucalli

    Directory of Open Access Journals (Sweden)

    Weibo Qiao

    2018-01-01

    Full Text Available Phytochemical analysis of different Euphorbia tirucalli tissues revealed a contrasting tissue-specificity for the biosynthesis of euphol and β-sitosterol, which represent the two pharmaceutically active steroids in E. tirucalli. To uncover the molecular mechanism underlying this tissue-specificity for phytochemicals, a comprehensive E. tirucalli transcriptome derived from its root, stem, leaf and latex was constructed, and a total of 91,619 unigenes were generated with 51.08% being successfully annotated against the non-redundant (Nr protein database. A comparison of the transcriptome from different tissues discovered members of unigenes in the upstream steps of sterol backbone biosynthesis leading to this tissue-specific sterol biosynthesis. Among them, the putative oxidosqualene cyclase (OSC encoding genes involved in euphol synthesis were notably identified, and their expressions were significantly up-regulated in the latex. In addition, genome-wide differentially expressed genes (DEGs in the different E. tirucalli tissues were identified. The cluster analysis of those DEGs showed a unique expression pattern in the latex compared with other tissues. The DEGs identified in this study would enrich the insights of sterol biosynthesis and the regulation mechanism of this latex-specificity.

  9. Lasiodiplodia species associated with dying Euphorbia ingens in ...

    African Journals Online (AJOL)

    Various species of Euphorbia occur in South Africa, including herbaceous, succulent and woody types. The largest of the succulent Euphorbia spp. in South Africa is Euphorbia ingens. These trees have been dying at an alarming rate in the Limpopo province during the course of the last 15 years. Investigations into the ...

  10. Latex in the Hospital Environment

    Science.gov (United States)

    LATEX in the Hospital Environment Updated Fall 2015 This list provides a guide to some of the most common objects containing latex and offers some ... remover–Sepha Pharm) 1 LATEX in the Hospital Environment (continued) Frequently contains LATEX OR/Infection Control masks, ...

  11. Chromatographic study of Euphorbia cyparissias

    Directory of Open Access Journals (Sweden)

    Cristina, T. Romeo,

    2009-12-01

    Full Text Available The ectoparasitic population control is very difficult and includes numerous chemical substances and therapeutic techniques. Although efficient at first, the repeated use of acaricidal substances leads to the appearance of resistance. The more and more reduced efficacy of the therapeutic arsenal puts serious problems for the practitionersand increases the need of newer substances on the market. Besides this appears the problem of residues in eggs and meat, which is a serious impediment. Because of this the use of plant extracts is an attractive and promising research path. The investigations tied to the parasitic biocontrol have diversified with the study of the numerous control sources (fungi, plant extracts, volatile oils etc..In this context, the plant extracts can become an alternative source for the acaricidal control knowing that they constitute a rich source of efficient bioactive compounds. Unfortunately although at hand until today, not very much data is known about what determines theacaricidal activity of some plant extracts against the argaside ticks.The present work describes an in vitro CG-MS study for identification of Euphorbia cyparissias’ chemical composition.

  12. RAPD-PCR analysis of some species of Euphorbia grown in ...

    African Journals Online (AJOL)

    family ^____^

    2013-12-04

    Dec 4, 2013 ... This study attempts to identify species of Euphorbia (Euphorbia peplus, Euphorbia helioscopia,. Euphorbia granulata and Euphorbia hirta) grown in University of Baghdad Campus in Jadiriyah and determine the genetic polymorphism among them by using DNA markers generated by polymerase.

  13. Antibacterial activity of Euphorbia hirta against Streptococcus ...

    African Journals Online (AJOL)

    This investigation was conducted to determine the in-vitro effect of aqueous, ethanol and methanol crude extracts of Euphorbia hirta at concentrations ranging from 10mg/ml – 100mg/ml against three pathogenic bacteria (Streptococcus pneumoniae, Klebsiella pneumoniae and Proteus vulgaris) using cup plate method.

  14. Latex and friends

    CERN Document Server

    Dongen, M R C van

    2012-01-01

    LaTeX is a free, automated state-of-the-art typesetting system. This book teaches all the ins and outs of LaTeX which are needed to write an article, report, thesis, or book. The book teaches by example, giving many worked out examples showing input and output side by side. The book presents the most recent techniques for presenting data plots, complex graphics, and computer presentations, but does not require previous knowledge. However, it is also a reference for the more seasoned user, with pointers to modern techniques and packages. Recurring themes in the book are consistent and effective

  15. More math into Latex

    CERN Document Server

    Grätzer, George

    2007-01-01

    For close to two decades, Math into Latex has been the standard introduction and complete reference for writing articles and books containing mathematical formulas. In this fourth edition, the reader is provided with important updates on articles and books. An important new topic is discussed: transparencies (computer projections). Key features of More Math into Latex, 4th edition: Installation instructions for PC and Mac users; An example-based, visual approach and a gentle introduction with the Short Course; A detailed exposition of multiline math formulas with a Visual Guide; A unified appr

  16. Latex allergy in health care

    Directory of Open Access Journals (Sweden)

    Tina Virtič

    2012-11-01

    Full Text Available The increasing use of natural rubber latex medical gloves in the last three decades has caused an increase in latex allergy. The majority of risk groups for allergy development include health care workers, workers in the rubber industry, atopic individuals and children with congenital malformations. Three types of pathological reactions can occur in people using latex medical gloves: irritant contact dermatitis, allergic contact dermatitis and immediate hypersensitivity. The latex allergy is caused by constituent components of latex gloves and added powders; there are also numerous latex allergens involved in cross-reactivity between latex and fruits and vegetables, the so-called latex-fruit syndrome. The diagnosis is based on an accurate history of exposure, clinical presentation and confirmatory in vivo and in vitro tests. Prevention is the easiest, most effective and least expensive way to avoid latex allergy. Powder-free latex gloves with reduced levels of proteins and chemicals, and synthetic gloves for allergic workers must be provided in the work environment. There are already many health care institutions around the world where all latex products have been replaced by synthetic material products.

  17. The Possibilities to use Euphorbia Tirucalli as an Energy and a Rubber Crop

    Directory of Open Access Journals (Sweden)

    Patrick Van Damme

    1990-02-01

    Full Text Available Euphorbia tirucalli has been used as a source for natural rubber at different times in history, especially in southern Africa. The latex resin content is too high to guarantee a good quality product and economic production has never taken off as some had hoped. The fact that the plant is very well adapted to arid and semi arid conditions and can be grown on marginal waste lands makes it a potential energy crop which can be turned into biogas without too much investment in costly technology. The first results obtained in the laboratory and in field conditions (Senegal are very promising. The latex contains a number of interesting triterpenes which have a very high energy content and could be used in fuel production. Most of these applications have been tested or used in Africa and can offer long-term solutions for old problems, particularly in the case of renewable energy through biomass fermentation. KEY WORDS: rubber, biomass, biogas, triterpenes, energy crop

  18. Chemical Investigation of Euphorbia schimperi C. Presl

    Directory of Open Access Journals (Sweden)

    Azza R. Abdel-Monem

    2008-08-01

    Full Text Available Three triterpenoids; cycloart-25-en-3β,24-diol, cycloart-23-en-3β,25-diol, and a -amyrin, in addition to b -sitosterol- b -D-O-glucoside, scopoletin, luteolin and kampferol were isolated for the first time from the chloroform fraction of the alcoholic extract of Euphorbia schimperi C. Presl (F. Euphorbiaceae. The isolated compounds were identified using different spectroscopic methods (EIMS, 1HNMR, 13CNMR, HMQC, HMBC and COSY. The cytotoxic activity of the chloroform fraction was also studied using brain and breast carcinoma cell lines.

  19. Latex medical gloves

    DEFF Research Database (Denmark)

    Palosuo, Timo; Antoniadou, Irini; Gottrup, Finn

    2011-01-01

    Many hospitals have implemented policies to restrict or ban the use of devices made of natural rubber latex (NRL) in healthcare as precautionary measures against the perceived risk of NRL allergy. Changes in glove technology, progress in measuring the specific allergenic potential of gloves...... properties of NRL and synthetic gloves and the role of glove powder. The review shows that NRL medical gloves, when compared with synthetic gloves, tend to be stronger, more flexible and better accepted by clinicians. The introduction of powder-free gloves has been associated with reductions in protein...

  20. Latex allergy in the workplace.

    Science.gov (United States)

    Toraason, M; Sussman, G; Biagini, R; Meade, J; Beezhold, D; Germolec, D

    2000-11-01

    While less than 1% of the general population is sensitized to latex, the U.S. Occupational Safety and Health Administration estimates that 8-12% of health-care workers are sensitized. The major source of workplace exposure is powdered natural rubber latex (NRL) gloves. NRL is harvested from HEVEA: brasiliensis trees and ammoniated to prevent coagulation resulting in the hydrolysis of the latex proteins. Prior to use in manufacturing, the latex is formulated by the addition of multiple chemicals. Thus, human exposure is to a mixture of residual chemicals and hydrolyzed latex peptides. Clinical manifestations include irritant contact dermatitis, allergic contact dermatitis (type IV), and type I immediate hypersensitivity response. Type I (IgE-mediated) NRL allergy includes contact urticaria, systemic urticaria, angioedema, rhinitis, conjunctivitis, bronchospasm, and anaphylaxis. Taking an accurate history, including questions on atopic status, food allergy, and possible reactions to latex devices makes diagnosis of type-I latex allergy possible. To confirm a diagnosis, either in vivo skin prick testing (SPT) or in vitro assays for latex-specific IgE are performed. While the SPT is regarded as a primary confirmatory test for IgE-mediated disease, the absence of a U.S. Food and Drug Administration-licensed HEVEA: brasiliensis latex extract has restricted its use in diagnosis. Serological tests have, therefore, become critically important as alternative diagnostic tests. Three manufacturers currently have FDA clearance for in vitro tests, to detect NRL-specific IgE. The commercially available assays may disagree on the antibody status of an individual serum, which may be due to the assay's detecting anti-NRL IgEs to different allergenic NRL proteins. Sensitized individuals produce specific IgE antibody to at least 10 potent HEVEA: allergens, Hev b 1-Hev b 10, each of which differs in its structure, size, and net charge. The relative content and ratios of Hevs in the

  1. Proteases from Latex of Euphorbia spp. and Its Application on Milk Clot Formation

    Directory of Open Access Journals (Sweden)

    Fidia Fibriana

    2015-09-01

    Full Text Available Crude proteases were extracted from Euphorbiaceae family, i.e. E. milii var imperata, E. trigona, and E. maculata. Among those three crude proteases, the activity of protease from E. trigona was the highest (812.50 U/ml, whereas E. milii and E. maculata crude proteases activity were 298.60 U/ml and 95.80 U/ml, respectively. E. maculata protein concentration was the highest among those three crude enzymes (1.206 mg/ml. The optimum pH and temperature of the enzymes were pH 7.0, pH 6.0, pH 6.5 and 60 °C, 50 °C, and 50 °C, respectively. Crude protease from E. milii var imperata, E. trigona, and E. maculata retained proteolytic activity over a wide range of pH (5.0–9.0 and temperature (up to 65 °C with casein as substrate. All crude proteases showed milk clotting activity ranged from 0.58 U/ml to 1.01 U/ml. Thus, these crude proteases are potential to be applied in dairy industries. However, further study on enzyme purification and characterization are necessary to obtain high purity of proteases before its application.Protease kasar berhasil diekstrak dari tanaman family Euphorbiaceae, yaitu E. milii var imperata, E. trigona, dan E. maculata. Diantara ketiga protease tersebut, aktivitas protease tertinggi diperoleh dari E. trigona (812,50 U/ml, sedangkan aktivitas protease dari E. milii dan E. maculata adalah 298,60 U/ml dan 95,80 U/ml, berturut-turut. Konsentrasi total protein tertinggi terdapat pada protease kasar E. maculata (1,206 mg/ml. pH dan suhu optimum ketiga enzim tersebut adalah pH 7.0, pH 6.0, pH 6.5 dan suhu 60 °C, 50 °C, and 50 °C, berturut-turut. Protease kasar dari E. milii var imperata, E. trigona, dan E. maculata menunjukkan aktivitas proteolitik pada rentang pH 5.0–9.0 dan rentang suhu sampai 65 °C menggunakan kasein sebagai substrat. Semua protease kasar menunjukkan aktivitas penggumpalan susu dengan rentang dari 0,58 U/ml sampai 1,01 U/ml. Berdasarkan hasil yang diperoleh, protease kasar dari ketiga jenis tanaman ini berpotensi untuk diaplikasikan dalam industri olahan susu. Meskipun demikian, studi lanjut mengenai purifikasi dan karakterisasi sangat diperlukan untuk memperoleh protease murni sebelum aplikasi dalam industri makanan, khususnya pada industri olahan susu.

  2. Phytotoxin produced by Bipolaris euphorbiae in-vitro is effective against the weed Euphorbia heterophylla

    Directory of Open Access Journals (Sweden)

    Barbosa Aneli M.

    2002-01-01

    Full Text Available Four virulent strain isolates of the fungus, Bipolaris euphorbiae (previously identified as a Helminthosporium sp., isolated from host plants in four states within Brazil were screened for the production of phytotoxins that promoted wilting and defoliation of the Brazilian weed, Euphorbia heterophylla, commonly found growing among soyabean crops. Only one isolate, B. euphorbiae Strain I (EUPH petropar from Mato Grosso state, produced phytotoxin in-vitro when grown in stationary culture for 7 d at 28 ° C on minimum salts medium supplemented with 1.5 % glucose as the sole carbon source. Phytotoxin was also produced when the fungal strain was grown on fructose, galactose, mannose, xylose and sucrose. The addition of nitrogen source (yeast extract, peptone or malt extract to the culture medium did not influence phytotoxin production. The phytotoxin produced by Strain I was most active at pH 6.0, stable between pH 3-9, and was highly thermostable, remaining fully active when heated at 90 ° C for 1 h.

  3. Methanic fermentation of Euphorbia tirucalli, a rich and renewable vegetal biomass of the Sahel and arid zones

    Energy Technology Data Exchange (ETDEWEB)

    Sow, D. [Dakar Univ. (Senegal); Depeyre, D.; Isambert, A. [Ecole Centrale des Arts et Manufactures, 92 - Chatenay-Malabry (France)

    1994-12-31

    A rich and renewable vegetal biomass is existing in Senegal. In fact Euphorbia tirucalli is a latex plant well adapted to sahelian climatic conditions, spread all along the country. In this work, methanic fermentation experimentations are made with this plant in a specific continuous fermentor named Transpaille. A 120 l biodigester was tested at 37 deg C with a piece-broken plant. The registered volumic efficiency is 0.80 l/l.d. With this interesting result, the same experiment was made with real operating conditions on a village digester in a farm. With a bioreactor of 12 m{sup 3}, incubated at ambient temperature, the obtained volumic efficiency is 0.61 l/l.d. The produced biogas of this experiment was used for food cooking and for farm milk cooling. This work shows that a vulgarization policy of the biogas way in rural conditions in Senegal is now possible with Euphorbia tirucalli. (authors). 19 refs., 6 figs., 2 tabs.

  4. Evolutionary bursts in Euphorbia (Euphorbiaceae) are linked with photosynthetic pathway.

    Science.gov (United States)

    Horn, James W; Xi, Zhenxiang; Riina, Ricarda; Peirson, Jess A; Yang, Ya; Dorsey, Brian L; Berry, Paul E; Davis, Charles C; Wurdack, Kenneth J

    2014-12-01

    The mid-Cenozoic decline of atmospheric CO2 levels that promoted global climate change was critical to shaping contemporary arid ecosystems. Within angiosperms, two CO2 -concentrating mechanisms (CCMs)-crassulacean acid metabolism (CAM) and C4 -evolved from the C3 photosynthetic pathway, enabling more efficient whole-plant function in such environments. Many angiosperm clades with CCMs are thought to have diversified rapidly due to Miocene aridification, but links between this climate change, CCM evolution, and increased net diversification rates (r) remain to be further understood. Euphorbia (∼2000 species) includes a diversity of CAM-using stem succulents, plus a single species-rich C4 subclade. We used ancestral state reconstructions with a dated molecular phylogeny to reveal that CCMs independently evolved 17-22 times in Euphorbia, principally from the Miocene onwards. Analyses assessing among-lineage variation in r identified eight Euphorbia subclades with significantly increased r, six of which have a close temporal relationship with a lineage-corresponding CCM origin. Our trait-dependent diversification analysis indicated that r of Euphorbia CCM lineages is approximately threefold greater than C3 lineages. Overall, these results suggest that CCM evolution in Euphorbia was likely an adaptive strategy that enabled the occupation of increased arid niche space accompanying Miocene expansion of arid ecosystems. These opportunities evidently facilitated recent, replicated bursts of diversification in Euphorbia. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

  5. Latex allergy and filaggrin null mutations

    DEFF Research Database (Denmark)

    Carlsen, Berit C; Meldgaard, Michael; Hamann, Dathan

    2011-01-01

    to aeroallergens and it is possible that filaggrin null mutations also increase the risk of latex allergy. The aim of this paper was to examine the association between filaggrin null mutations and type I latex allergy. Methods Twenty latex allergic and 24 non-latex allergic dentists and dental assistants...... in the cases in this study may not have occurred through direct skin contact but through the respiratory organs via latex proteins that are absorbed in glove powder and aerosolized...

  6. Biosynthesis of macrocyclic diterpenoids in Euphorbia lathyris L

    DEFF Research Database (Denmark)

    Luo, Dan

    documents the investigation of the biosynthetic pathways of macrocyclic diterpenoids known as Euphorbia factors in Euphorbia lathyris L. (caper spurge). These macrocyclic diterpenoids are the current industrial source of ingenol mebutate, which is approved for the treatment of actinic keratosis...

  7. Latex allergies - for hospital patients

    Science.gov (United States)

    ... ency/patientinstructions/000499.htm Latex allergies - for hospital patients To use the sharing features on this page, ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  8. Cream concentrated latex for foam rubber products

    Science.gov (United States)

    Suksup, R.; Imkaew, C.; Smitthipong, W.

    2017-12-01

    Fresh natural latex (around 40% rubber and 60% water) can be transformed to concentrated natural latex (around 60% rubber and 40% water) in order to realise economical transportation and easier latex product’s preparation. The concentrated natural latex is an extremely valuable material. It can be applied for many types of products, for example, foam rubber as pillow and mattress, elastic band, etc. Industrially, the concentrated natural latex can be prepared by centrifugation which requires an enormous expensive machine. From the eco-friendly products point of view, most of rubber entrepreneurs in the world try to develop a green rubber product. So, the main objective of this study is to prepare the cream concentrated latex without any sophisticated machine. Thus, we work on a simple, cheap and green method that does not use any expensive machine but uses water-based chemical as sodium alginate to prepare the cream concentrated latex. The optimal amount of sodium alginate in the latex was studied. The main characteristics of the cream concentrated latex were tested by various technics, such as alkalinity, total solid content (TSC), dry rubber content (DRC), etc. We found that there are no significant differences of results between fresh natural latex and cream concentrated latex, except for the TSC and DRC. The TSC and DRC of cream latex are higher than those of fresh natural latex. Finally, we propose a model of natural rubber particle and sodium alginate to form the cream concentrated latex.

  9. In Vitro Anticancer Activity of Ethanolic Extract of Euphorbia hirta (L ...

    African Journals Online (AJOL)

    In the present study, In vitro anticancer effects of Euphorbia hirta were investigated. The objectives of this study are to find the presence of secondary metabolites by preliminary phytochemical investigation and FTIR analysis in the Euphorbia hirta. Ethanolic leaf extract of Euphorbia hirta was tested for its cytotoxicity against ...

  10. Euphorbia neriifolia L.: Review on botany, ethnomedicinal uses, phytochemistry and biological activities.

    Science.gov (United States)

    Mali, Prashant Y; Panchal, Shital S

    2017-05-01

    The present review is intended to provide information on botany, ethnomedicinal uses, phytochemistry and biological activities of various parts of Euphorbia neriifolia (E. neriifolia). E. neriifolia has several ethnomedicinal uses. The latex of E. neriifolia is used as laxative, purgative, rubefacient, carminative and expectorant as well as in treatment of whooping cough, gonorrhoea, leprosy, asthma, dyspepsia, jaundice, enlargement of the spleen, tumours, stone in the bladder, abdominal troubles and leucoderma. Leaves are brittle, heating, carminative, and good for improving the appetite and treatment of tumours, pains, inflammations, abdominal swellings and bronchial infections. Roots are used as symptomatic treatment of snake bite, scorpion sting and antispasmodic. Various plant parts or whole E. neriifolia extract and its isolates have been reported scientifically using various in-vivo and in-vitro experimental methods for anaesthetic, analgesic, anti-anxiety, anti-convulsant, anti-psychotic, anti-arthritis, anti-carcinogenic, antidiabetic, anti-diarrhoeal, anti-inflammatory, anti-thrombotic, antimicrobial, antioxidant, antiulcer, cytotoxic, death-receptor expression enhancing, dermal irritation, diuretic, haemolytic, immunomodulatory, radioprotective, scorpion venom and wound healing properties. It is reported to have chemical constituents like, neriifolin-S, neriifolin, neriifoliene, euphol, neriifolione, cycloartenol, nerifoliol, lectin, euphonerins A-G, 3-O-acetyl-8-O-tigloylingol, taraxerol, antiquorin, etc. Identified chemical constituents are still required to be explored for their advanced isolation techniques and biological activities. Copyright © 2017 Hainan Medical University. Production and hosting by Elsevier B.V. All rights reserved.

  11. Keratouveitis from Euphorbia cyparissias exposure is a temporal phenomenon

    Directory of Open Access Journals (Sweden)

    Fleischman D

    2012-06-01

    Full Text Available David Fleischman, Jay J Meyer, W Craig FowlerDepartment of Ophthalmology, University of North Carolina Hospitals, Chapel Hill, NC, USAAbstract: We present the case of an 82-year-old woman with severe keratouveitis secondary to exposure to the plant Euphorbia cyparissias during the month of August. Despite copious irrigation of both eyes, she developed a case of Euphorbia keratouveitis that was typical in its course. Exposure to plant sap from this species should be treated much like an alkaline chemical injury as the pH of the ocular surface may be elevated. E. cyparissias should be carefully handled as it may result in keratouveitis, especially in early autumn.Keywords: Euphorbia cyparissias, sap, keratitis, uveitis

  12. Encapsulation of Clay Platelets inside Latex Particles

    NARCIS (Netherlands)

    Voorn, D.J.; Ming, W.; Herk, van A.M.; Fernando, R.H.; Sung, Li-Piin

    2009-01-01

    We present our recent attempts in encapsulating clay platelets inside latex particles by emulsion polymerization. Face modification of clay platelets by cationic exchange has been shown to be insufficient for clay encapsulation, leading to armored latex particles. Successful encapsulation of

  13. Phytogeographical Analysis Of Euphorbia Subgenus Esula (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    Geltman Dmitry V.

    2015-12-01

    Full Text Available Euphorbia subg. Esula is one of four major clades within the genus. A geographical analysis of the 466 species in the subgenus is reported here. Every species was assigned to one of 29 geographical elements clustered in ten groups of elements. This geographical analysis showed that the Tethyan group (comprising nine geographical elements clearly dominates the subgenus and contains 260 species (55.79% of the total number of species. The most numerous geographical elements are Irano-Turanian (105 species and Mediterranean (85. Other significant groups of elements are Boreal (91 species, 19.54%, East Asian (40 species, 8.58%, Madrean (26 species, 5.58%, Paleotropical (23 species, 4.94% and South African (16 species, 3.43%. The area of the Tethyan floristic subkingdom is the center of the modern diversity of E. subg. Esula. It is likely that such diversity is the result of intensive speciation that took place during the Eocene–Miocene.

  14. Quality and quantity of latex which can be produced from natural vegetation in Greece

    Energy Technology Data Exchange (ETDEWEB)

    Margaris, N.S.; Vokou, D.; Diamantopoulos, J.

    1985-01-01

    Euphorbiaceae is one of the major latex producing families very promising in terms of exploitation as energy sources. Research in the Greek areas proved that Euphorbia species are very numerous with high contribution in biomass terms in many of them. Provided are data concerning growth characteristics of E. dendroides and E. acanthothamnos to answer the question of the feasibility of harvesting. E. helioscopia is proved to be a very promising species with many ecotypes. Its occurrence and extremely increased growth in olive, almonds, and pear plantations makes it a very important species needing further research to evaluate the possibility of combined cultivation with the above mentioned trees. It is estimated the oil production that such plantations may yield.

  15. Managing latex allergies at home

    Science.gov (United States)

    ... Associate Clinical Professor of Medicine, Division of Allergy, Immunology, and Rheumatology, Georgetown University Medical School, Washington, DC. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Related MedlinePlus Health Topics Latex Allergy Browse the Encyclopedia A.D.A. ...

  16. Latex Allergy - A Case Report

    Directory of Open Access Journals (Sweden)

    Dr. Athma Prasanna

    2005-10-01

    Full Text Available The usage of rubber and its products are not uncommon in various walks of life. A continuous exposure or contact may sensitize the human body, causing reactions from mild to fatal. Despite the availability of the literature, medical personnel are still unaware of the implications of the use of latex materials.

  17. Effect of Euphorbia hirta and Thymus vulgaris powders on ...

    African Journals Online (AJOL)

    The ban placed on the long term use of commercial antibiotics at subtherapeutic levels for diseases control and growth promotion in livestock production necessitated a worldwide search for available, cost effective and efficacious alternatives. Accordingly, the effects of Euphorbia hirta (EH) and Thymus vulgaris (TV) ...

  18. Antimicrobial activity of Caesalpinia pulcherrima, Euphorbia hirta and Asystasia gangeticum.

    Science.gov (United States)

    Sudhakar, M; Rao, Ch V; Rao, P M; Raju, D B; Venkateswarlu, Y

    2006-07-01

    The ethanolic extracts of the dry fruits of Caesalpinia pulcherrima, aerial parts of Euphorbia hirta and flowers of Asystasia gangeticum were tested for antimicrobial activity. The three plants exhibited a broad spectrum of antimicrobial activity, particularly against Escherichia coli (enteropathogen), Proteus vulgaris, Pseudomonas aeruginosa and Staphylococcus aureus.

  19. Effects of chromatographic fractions of Euphorbia hirta on the rat ...

    African Journals Online (AJOL)

    The effects of the chromatographic fractions of Euphorbia hirta Linn on the serum biochemical parameters in rats were investigated. The ethanolic extract of this plant was subjected to chromatographic separation using the vacuum liquid chromatographic technique, a modified form of classical column chromatography.

  20. Antimicrobial efficacy and tissue reaction of Euphorbia hirta ...

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... Department of Veterinary Surgery and Reproduction, Faculty of Veterinary Medicine, University of Ibadan, Oyo State,. Nigeria. Accepted 22 March, 2010. Antimicrobial efficacy and tissue reaction of crude ethanolic extract of Euphorbia hirta was investigated in canine infected incised wounds. The gross ...

  1. Effect Of Euphorbia Cyparissias Ointments On Acanthosis | Cristina ...

    African Journals Online (AJOL)

    ... of Euphorbiacae were identified, revealing a large plant family with a polyvalent therapeutic activity. Materials and Methods: The aim of the study was to assess the skin tolerance level to irritation on different testing concentrations, of Euphorbia cyparissias extracts and ointments. Study was accomplished in rats and dogs, ...

  2. Updates on the genus Euphorbia (Euphorbiaceae) in Santa Catarina, Brazil

    DEFF Research Database (Denmark)

    Hassemer, Gustavo; Marques da Silva, Otávio Luis; Funez, Luís Adriano

    2017-01-01

    This contribution presents updates to the knowledge of the species of Euphorbia that occur in Santa Catarina state, southern Brazil. More specifically, we here typify the names E. cyathophora, E. hirtella, E. paranensis and E. stenophylla, and present the first records of E. cyathophora, E...

  3. Antileishmanial activity of piceatannol isolated from Euphorbia lagascae seeds

    NARCIS (Netherlands)

    Duarte, Noelia; Kayser, Oliver; Abreu, Pedro; Ferreira, Maria-Jose U.

    In the search for biologically active compounds from Euphorbia lagascae Spreng, an herbaceous plant native to southeast of Iberic Peninsula, a stilbene, two coumarins and two 1-2-deoxyphorbol diterpene esters were isolated by chromatographic methods, from the methanol extracts of its defatted seeds.

  4. Studies on wound healing activity of some Euphorbia species on ...

    African Journals Online (AJOL)

    Background: Plants of Euphorbiaceae are used in folkloric medicines in variety of ailments and well known for chemical diversity of their isoprenoid constituents. This study was carried out to explore the preliminary wound healing potential of four Euphorbia species (E. consorbina 1, E. consorbina 2, E. inarticulata, ...

  5. COMPARATIVE ANATOMICAL ASPECTS OF EUPHORBIA MILLI VAR. SPLENDENS (BOJER EX HOOK. URSCH & LEANDRI AND EUPHORBIA PULCHERRIMA WILLD. EX KLOTZSCH SPECIES LEAVES

    Directory of Open Access Journals (Sweden)

    Rodica BERCU

    2016-12-01

    Full Text Available The paper presents a comparative study concerning the leaf structure of two Euphorbia species belonging to Euphorbiaceae family: Euphorbia milli var. splendens (Bojer ex Hook. Ursch & Leandri and Euphorbia pulcherrima Willd. ex Klotzsch. Anatomically, the leaves of the studied species are quite similar in the basic structure. The petiole has a single-layered epidermis, a collenchyma tissue – hypodermis - and three collateral bundles embedded in a basic tissue. Differences occur concerning the relationship between the collateral bundles. The Euphorbia pulcherrima bract petiole has almost the same structure as those of the leaf petiole. The blade is amphistomatic for Euphorbia milli var. splendes and hipostomatic for E. pulcherrima. The heterogeneous mesophyll is isobilateral in Euphorbia milli var. splendens blade and bifacial in E. pulcherrima. The vascular system of the mid rib is represented by one collateral bundle for both species, more developed in Euphorbia milli var. splendens blade. Differences appear concerning the epidermal cells cuticle thickness, the type of mesophyll, the abundance of the non-articulated laticifers and the development of the vascular system. The Euphorbia pulcherrima bract has the same organization plan structure as the leaf blade but some features differences occur.

  6. Characterization of Thermo- and Detergent Stable Antigenic Glycosylated Cysteine Protease of Euphorbia nivulia Buch.-Ham. and Evaluation of Its Ecofriendly Applications

    Directory of Open Access Journals (Sweden)

    Shamkant B. Badgujar

    2013-01-01

    Full Text Available An antigenic glycosylated cysteine protease has been purified from the latex of Euphorbia nivulia Buch.-Ham. It exhibits remarkable protease activity in the presence of metal ions, oxidizing agents, organic solvents, and detergents. This enzyme showed potential role in leather processing industry due to its dehairing activity for animal hide without hydrolyzing fibrous proteins, producing, by this way, a better quality product. The enzyme can also be used for silver recovering from X-ray plates. In addition, the stability (temperature and surfactants and hydrolysis of blood stain data also revealed its application in detergent industries. Agriculturally, this protease finds application in biocontrol process against the infectious management of root knot nematode, Meloidogyne incognita. Biologically, it shows noticeable wound healing, haemostatic and antibacterial activity.

  7. Particle size, morphology and color tunable ZnO:Eu{sup 3+} nanophosphors via plant latex mediated green combustion synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Chandrasekhar, M. [Prof. C.N.R. Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103 (India); Department of Physics, Acharya Institute of Technology, Bangalore 560 107 (India); Nagabhushana, H., E-mail: bhushanvlc@gmail.com [Prof. C.N.R. Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103 (India); Sharma, S.C. [B.S. Narayan Centre of Excellence for Advanced Materials, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064 (India); Department of Mechanical Engineering, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064 (India); Sudheer kumar, K.H. [Department of Environmental Science, Kuvempu University, Shankarghatta, Shimoga 577 451 (India); Department of Chemistry, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064 (India); B.S. Narayan Centre of Excellence for Advanced Materials, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064 (India); Dhananjaya, N. [Department of Physics, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064 (India); B.S. Narayan Centre of Excellence for Advanced Materials, B.M.S. Institute of Technology, Yelahanka, Bangalore 560 064 (India); Sunitha, D.V. [Prof. C.N.R. Rao Centre for Advanced Materials, Tumkur University, Tumkur 572 103 (India); Shivakumara, C. [Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012 (India); Nagabhushana, B.M. [Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054 (India)

    2014-01-25

    Highlights: • ZnO:Eu{sup 3+} phosphors were prepared by green synthesis route. • Morphology and particle size was tuned by varying the concentration of plant latex. • The phosphor show excellent chromaticity coordinates in the white region. -- Abstract: Efficient ZnO:Eu{sup 3+} (1–11 mol%) nanophosphors were prepared for the first time by green synthesis route using Euphorbia tirucalli plant latex. The final products were well characterized by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible spectroscopy (UV–Vis), Fourier transform infrared spectroscopy (FTIR), etc. The average particle size of ZnO:Eu{sup 3+} (7 mol%) was found to be in the range 27–47 nm. With increase of plant latex, the particle size was reduced and porous structure was converted to spherical shaped particles. Photoluminescence (PL) spectra indicated that the peaks situated at ∼590, 615, 648 and 702 nm were attributed to the {sup 5}D{sub 0} → {sup 7}F{sub j(j=1,2,3,4)} transitions of Eu{sup 3+} ions. The highest PL intensity was recorded for 7 mol% with Eu{sup 3+} ions and 26 ml plant latex concentration. The PL intensity increases with increase of plant latex concentration up to 30 ml and there after it decreases. The phosphor prepared by this method show spherical shaped particles, excellent chromaticity co-ordinates in the white light region which was highly useful for WLED’s. Further, present method was reliable, environmentally friendly and alternative to economical routes.

  8. Euphorbia gummifera. A. gregaria and a new species from Damaraland

    Directory of Open Access Journals (Sweden)

    L. C. Leach

    1975-11-01

    Full Text Available The identity of  Euphorbia gummifera Boiss. and  E. gregaria Marl, is discussed and a new species, E. damarana Leach, is described. A key to the species including  E. carunculifera Leach from southern Angola and a map showing their distribution are provided. The possible significance of these species in the phylogeny of the genus is also discussed.

  9. Latex sensitisation in healthcare workers in Singapore.

    Science.gov (United States)

    Tang, M B Y; Leow, Y H; Ng, V; Koh, D; Goh, C L

    2005-06-01

    Epidemiological data on latex sensitisation among Asian healthcare workers is lacking. The aim of the study is to determine the rate of latex sensitisation in our healthcare workers. We recruited 313 healthcare workers, of which 46.6% were operating theatre staff and 53.4% were non-operating theatre staff. Seventy-one administrative staff served as controls. All participants answered a self-administered questionnaire relating to latex exposure and glove-related symptoms. Latex sensitisation was determined by skin prick testing to latex and latex-specific IgE detection. The prevalence of latex sensitisation among healthcare workers was 9.6%, with no difference between operating theatre and nonoperating theatre staff. Glove-related symptoms were reported in 13.7% of all healthcare workers, of which 22.9% were sensitised to latex. Only 26.7% of latex-sensitised healthcare workers had glove-related symptoms while the rest were asymptomatic. The most common symptoms were itch and hand eczema but the most important discriminating symptom was contact urticaria. Personal history of atopy was more common in sensitised healthcare workers (40.0%) compared to non-sensitised workers (31.8%). Only 1 out of 9 (11.2%) symptomatic latex-sensitised subjects had sought previous medical attention for the problem. Latex sensitisation among healthcare workers in Singapore should be considered a significant occupational health risk, as it is in the West. Increased screening and awareness of this problem is essential to identify those at risk.

  10. Latex Allergy In Health Care Workers

    Directory of Open Access Journals (Sweden)

    Hayriye Sarıcaoğlu

    2013-05-01

    Full Text Available Background and Design: We aimed to determine the frequency of latex allergy in our hospital and to to evaluate the clinical and demographical features of the cases.Materials and Methods: A detailed questionnaire was administered to healthcare workers by a physician. Skin prick test with latex and patch test with rubber chemicals and a piece of latex glove were performed for all healthcare workers. Latex-specific IgE was measured in serum.Results: The study sample consisted of 36 nurses, 14 doctors, and 50 healthcare workers. While 46 subjects had symptoms, 54 subjects had no symptoms. The relationship of clinical disease with working duration, exposure duration (hour/day, history of atopy, and drug/food allergies was statistically significant. Five nurses and 1 healthcare worker had positive skin prick test. Two of them had positive latex-specific IgE. Positive skin prick test statistically significantly correlated with occupation, working duration, exposure duration (hour/day and positive latex-specific IgE. Two nurses and 2 healthcare workers had positive latex-specific IgE. Two of them had positive skin prick test. Positive latexspecific IgE statistically significantly correlated with working duration, exposure duration, and positive skin prick test. Patch test with a piece of latex glove was negative in all subjects. Three healthcare workers had positive patch test with thiuram-mix, one of them had also positive patch test with mercaptobenzothiazole.Discussion: One of the risk factors for latex allergy is occupations involving frequent exposure to latex products. Latex allergy should be taken into consideration if type I hypersensitivity reactions occur in occupational groups at risk for anaphylactic reaction.

  11. Effect of irradiation on the prevulcanized latex/low nitrosamines latex blends

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Pairu; Zin, Wan Manshol Wan [Malaysian Nuclear Agency, 43000 kajang, Selangor (Malaysia); Daik, Rusli [Faculty of Science and Technology, Universiti Kebangsaan Malaysia,43600 bangi, Selangor (Malaysia)

    2015-09-25

    Radiation Prevulcanized Natural Rubber Latex (RVNRL) was blended with Low Nitrosamines Latex (LNL) at different composition ratio. Methyl Metachrylate (MMA) was added for grafting onto the blended latex. Blended latex was subjected to gamma irradiation at various doses up to 8kGy. The mechanical properties and FTIR analysis were investigated as a function of the blended composition and irradiation dose. It was found that blending at specific ratio and gamma irradiation at specific dose led to significant improvement on the properties of the latex. The optimum mechanical properties was attained at a total blending ratio of 70% RVNRL and 30% of LNL.

  12. Decontamination of latex gloves; Decontamination de gants en latex

    Energy Technology Data Exchange (ETDEWEB)

    Boutot, P; Schipfer, P; Blachere, A [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

    1969-07-01

    Initially the latex gloves used in controlled zones were processed after use as radioactive waste. In view of the continually increasing number used, however, the persons in charge of the SPRAR have considered the possibility of decontaminating the gloves and using them again after control. The recovery installations which have been developed were initially designed rather crudely and operated irregularly; they have been progressively improved as a result of the experience acquired; today they are more really an industrial concern, equipped with automatic machinery. In 1967 it has been possible with this set-up to recover 247000 pairs of gloves, representing nearly 70 per cent of the number treated. (author) [French] Initialement, les gants de latex utilises dans les zones controlees etaient conditionnes apres emploi comme dechets radioactifs. Mais, devant l'augmentation sans cesse croissante des quantites employees, les responsables du SPRAR ont envisage leur decontamination et leur recyclage apres controles. Les installations de recuperation mises au point, de conception artisanale et fonctionnant de maniere episodique au depart, se sont progressivement ameliorees au fur et a mesure de l'experience acquise; elles revetent aujourd'hui le caractere d'une exploitation industrielle equipee de machines automatiques. En 1967, ces nouvelles installations ont permis de recuperer 247000 paires de gants, ce qui represente pres de 70 pour cent des quantites traitees. (auteur)

  13. Acute renal failure by ingestion of Euphorbia paralias

    Directory of Open Access Journals (Sweden)

    Karima Boubaker

    2013-01-01

    Full Text Available Euphorbia paralias is known in traditional medicine as an anti-inflammatory agent, a purgative and for its local anesthetic property. To the best our knowledge, renal toxicity of this substance has not been previously reported. In this paper, we report the case of a 29-year-old male who developed renal damage following ingestion of Euphorbia paralias. He had been on follow-up for nephrotic syndrome since 1986, although irregularly, with several relapses but each responding well to steroid therapy. A kidney biopsy had not been performed earlier due to refusal by the patient. He was off steroids since April 2008 because the patient developed osteoporosis. He was admitted with general malaise and oliguria to our department in May 2009, following repeated vomiting and watery diarrhea for three days. On examination, he was edematous but had normal vital signs except for a pulse rate of 120/min. Hemoglobin was only 5.5 g/dL but with normal white cell and platelet counts. Blood biochemistry showed evidence of advanced renal failure with a serum creatinine level of 1835 μmol/L and urea at 44.6 mmol/L, sodium of 132 μmol/L and potassium at 4.3 mmol/L. He had features of nephrotic syndrome with severe hypoproteinamia and 24-h urinary protein of 10.45 g. Ultrasonography revealed enlarged kidneys with a reduced echogenecity of the medulla and the papillae. Subsequently, after hemodialysis with blood transfusion, a kidney biopsy was performed that showed focal segmental glomerulosclerosis associated with an acute tubular injury. On intensive interrogation, the patient gave a history of ingesting boiled Euphorbia paralias as a native treatment for edema, ten days prior to the onset of the current illness. A diagnosis of acute renal failure (ARF resulting from the possible nephrotoxic effect of Euphorbia paralias poisoning was made. He was treated with intermittent hemodialysis and corticosteroids. Serum creatinine values improved after 48 days. At six

  14. EDITORIALS Latex allergy: 'Plight, rights and fights'

    African Journals Online (AJOL)

    anaphylaxis and life-threatening food allergies to cross-reacting fruit allergens such as kiwi, banana, tomato and chestnuts). Latex allergy is also encountered more frequently in children with spina bifida than in other hospitalised children.[7] Sensitisation is usually confirmed by commercial latex allergy skinprick testing or by ...

  15. Jackfruit anaphylaxis in a latex allergic patient.

    Science.gov (United States)

    Wongrakpanich, Supakanya; Klaewsongkram, Jettanong; Chantaphakul, Hiroshi; Ruxrungtham, Kiat

    2015-03-01

    Several fruits have been reported to crossreact with latex antigen in latex allergy patients but little is known regarding tropical fruits in particular. Here we report the case of a 34-year old nurse who developed anaphylaxis following the ingestion of dried jackfruit (Artocarpus heterophyllus). The patient had a history of chronic eczema on both hands resulting from a regular wear of latex gloves. She and her family also had a history of atopy (allergic rhinitis and/or atopic dermatitis). The results of skin prick tests were positive for jackfruit, latex glove, kiwi and papaya, but the test was negative for banana. While we are reporting the first case of jackfruit anaphylaxis, further research needs to be conducted to identify the mechanisms underlying it. In particular, in-vitro studies need to be designed to understand if the anaphylaxis we describe is due to a cross reactivity between latex and jackfruit or a coincidence of allergy to these 2 antigens.

  16. Latex improvement of recycled asphalt pavement

    Science.gov (United States)

    Drennon, C.

    1982-08-01

    The performance of a single unmodified milled recycled asphalt concrete was compared to milled asphalt concrete modified by addition of three types of rubber latex. Latex was added at 2, 3, 5, and 8 percent latex by weight of asphalt in the asphalt concrete. Lattices used were a styrene butadiene (SBR), a natural rubber (NR), an acrylonitrile butadiene (NBR), and four varieties of out of specification SBR lattices. Marshall tests, while indecisive, showed a modest improvement in properties of SBR and NR added material at 3 and 5 percent latex. Addition of NBR latex caused deterioration in Marshall stability and flow over that of control. Repeated load tests were run using the indirect tensile test, analyzed by the VESYS program, which computes life of pavements. Repeated load tests showed improvement in asphalt concrete life when 3 and 5 percent SBR was added. Improvement was also shown by the out of specification SBR.

  17. Nitrile versus Latex for Glove Juice Sampling.

    Science.gov (United States)

    Landers, Timothy F; Dent, Anthony

    2014-01-01

    The objective of this study was to explore the utility of nitrile gloves as a replacement for latex surgical gloves in recovering bacteria from the hands. Two types of nitrile gloves were compared to latex gloves using the parallel streak method. Streaks of Klebsiella pneumoniae and Staphylococcus aureus were made on tryptic soy agar plates, and the zones of inhibition were measured around pieces of glove material placed on the plates. Latex gloves produced a mean zone of inhibition of 0.28 mm, compared to 0.002 mm for nitrile gloves (pnitrile may be a viable alternative to latex in glove juice sampling methods, since nitrile avoids the risk of latex exposure.

  18. Nitrile versus Latex for Glove Juice Sampling.

    Directory of Open Access Journals (Sweden)

    Timothy F Landers

    Full Text Available The objective of this study was to explore the utility of nitrile gloves as a replacement for latex surgical gloves in recovering bacteria from the hands. Two types of nitrile gloves were compared to latex gloves using the parallel streak method. Streaks of Klebsiella pneumoniae and Staphylococcus aureus were made on tryptic soy agar plates, and the zones of inhibition were measured around pieces of glove material placed on the plates. Latex gloves produced a mean zone of inhibition of 0.28 mm, compared to 0.002 mm for nitrile gloves (p<.001. While the parallel streak method is not intended as a quantitative estimate of antimicrobial properties, these results suggest that nitrile may be a viable alternative to latex in glove juice sampling methods, since nitrile avoids the risk of latex exposure.

  19. Competencia de lecheron (Euphorbia dentata en soja Competition of spurge toothed (Euphorbia dentata in soybean

    Directory of Open Access Journals (Sweden)

    V.F. Juan

    2003-08-01

    Full Text Available Euphorbia dentata es una maleza anual, de ciclo primavero - estival que está presente en el 85% del área agrícola del partido de Azul, Pcia Buenos Aires Argentina, con densidades que oscilan entre 20 a 200 plantas m-2. Estudios en campo fueron conducidos durante dos años para determinar la relación de competencia entre soja y E. dentata a través de la evaluación del efecto de distintas densidades de la maleza sobre los componentes del rendimiento del cultivo y su biomasa. El peso seco y rendimiento de soja mostraron una respuesta dependiente de la densidad y de la biomasa de la maleza, siendo reducidos al 80% por la interferencia a partir de la densidad de 20 plantas m-2. En el rango de densidades estudiadas se observó una respuesta lineal que fue ajustada a una ecuación de regresión que indica que la producción de semillas de soja decrece 6,73 kg ha-1 por el incremento de cada planta m-2 de E. dentata. De los componentes del rendimiento del cultivo, el número de vainas por planta fue el más severamente afectado por la competencia obteniéndose reducciones del 40% respecto del tratamiento sin maleza. Altos niveles de correlación fueron observados entre el rendimiento de soja, el número de vainas por planta y el peso de 1.000 semillas (98 y 85% respectivamente.Euphorbia dentata is a spring-summer annual weed first detected in Azul Co., Buenos Aires Province, Argentina., in 1983, in an isolated soybean crop spot crops. It is now found as a weed in 85 % of the cropland, with densities ranging from 20 to 200 plants m-2. Two year- field studies were conducted to determine the competition relationship between soybean and E. dentata. The effect of different weed densities was evaluated on yield parameters and biomass. Both soybean dry weight and yield gave a significant response to weed density and biomass, resulting in a reduction of 80% due to interference starting at a density of 20 plants m². It was determined that E. dentata has a

  20. Transcript Profiling of Hevea brasiliensis during Latex Flow

    Directory of Open Access Journals (Sweden)

    Jinquan Chao

    2017-11-01

    Full Text Available Latex exploitation enhances latex regeneration in rubber trees. The latex exploitation-caused latex flow lasts from 10 min to a few hours, which is convenient for exploring the transcript profiling of latex metabolism-related genes at the different stages of latex flow. In the present study, the expression pattern of 62 latex metabolism-related genes involved in water transportation, carbohydrate metabolism, natural rubber biosynthesis, hormone signaling, ROS generation and scavenging, and latex coagulum across three stages of latex flow between rubber tree clones CATAS7-33-97 and CATAS8-79 were comparatively analyzed by quantitative real-time PCR. The two clones show differences in latex regeneration and have a different duration of latex flow. The results showed that the expression levels of 38 genes were significantly higher in CATAS8-79 latex than in CATAS7-33-97 during latex regeneration, while 45 genes had a notably higher expression level in CATAS8-79 latex during latex flow. Together with the activation of the MEP pathway and jasmonate pathway in CATAS8-79 latex, HbPIP1;3, HbPIP1;4, HbSUT3, HbSus3, HbHMGS1-2, HbMK should contribute to the high latex regeneration ability. The up-regulation of ethylene signaling and Hb44KD and the down-regulation of latex coagulation-related genes in CATAS8-79 latex might contribute to its longer latex flow duration. This study provides some cues for revealing the regulation of latex metabolism in rubber trees.

  1. [Latex allergy in a population at risk].

    Science.gov (United States)

    Ruiz Fernández, M; Flores Sandoval, G; Orea Solano, M

    1999-01-01

    The allergy to latex is an illness whose prevalence has been increased in very significant form in the last years. To know the allergy incidence to latex in population of risk, as well as to identify the related sintomatology and the importance or paper that play the atopia antecedents and time of contact with latex for the development of the illness. We carry out a prospective, descriptive, experimental and traverse study in population of risk, in the service of Allergy and clinical Immunology of the Hospital Regional Lic. Adolfo López Mateos, ISSSTE. One hundred patients of both sexes were included, with age of 20 to 50 years, with the antecedent of being personal medical and paramedic and to have presented contact with latex material in a minimum period of one year. They were carried out clinical history with registration of sintomatology nasal, bronchial, cutaneous and associated to contact with latex. They were carried out cutaneous test for prick to latex with positive control with the help of histamine solution and negative control with solution of Evans and immediate reading of the same one. 22% of the patients in study, they presented positive skin test latex, with a time of exhibition 10 year-old average, 68% presented antecedent of atopy personal, family and, likewise the associate sintomatology was in a 33.3% dermatology, 54.5 nasal, nobody presented bronchial symptoms and a 9% asymptomatic was reported. We support that the immediate skin test latex for Prick is an important parameter of support diagnosis for allergy to type 1 latex.

  2. Allergy to latex in health workers

    Directory of Open Access Journals (Sweden)

    Fajardo-Zapata, Álvaro L.

    2015-01-01

    Full Text Available Introduction: A common and growing problem in hospitals is hypersensitivity to rubber latex antigens, since many products, including gloves, are manufactured from this material, with the consequent possibility of producing allergy in persons who use them. Objective: To find out if health workers at a fourth level clinic in Bogotá, Colombia, are allergic to rubber latex, in relation to the use of gloves. Materials and methods: Descriptive, cross-sectional study of a non-probabilistic intentional-type sample in each one of four hospital units. A survey was applied to participants. Results: 16 of the 26 persons (61.5% with history of allergic processes manifested some kind of reaction when they had contact with latex gloves; the problem was more significant in the nursing personnel compared to physicians. Conclusions: The exposure to latex gloves may be generating the appearance of allergic occupational disease in health workers.

  3. Latex glove sensitivity amongst diagnostic imaging healthcare ...

    African Journals Online (AJOL)

    kemrilib

    Sciences, Faculty of Health Sciences and Technology, University of Nigeria, Enugu Campus, Enugu. State, Nigeria. .... Occupation. No of .... latex protein residue and act as a hapten or .... at Work Act, 1989 and the safety, Health and Welfare at.

  4. Biological Activities of Aerial Parts Extracts of Euphorbia characias

    Directory of Open Access Journals (Sweden)

    Maria Barbara Pisano

    2016-01-01

    Full Text Available The aim of the present study was to evaluate antioxidant, antimicrobial, anti-HIV, and cholinesterase inhibitory activities of aqueous and alcoholic extracts from leaves, stems, and flowers of Euphorbia characias. The extracts showed a high antioxidant activity and were a good source of total polyphenols and flavonoids. Ethanolic extracts from leaves and flowers displayed the highest inhibitory activity against acetylcholinesterase and butyrylcholinesterase, showing potential properties against Alzheimer’s disease. Antimicrobial assay showed that leaves and flowers extracts were active against all Gram-positive bacteria tested. The ethanolic leaves extract appeared to have the strongest antibacterial activity against Bacillus cereus with MIC value of 312.5 μg/mL followed by Listeria monocytogenes and Staphylococcus aureus that also exhibited good sensitivity with MIC values of 1250 μg/mL. Moreover, all the extracts possessed anti-HIV activity. The ethanolic flower extract was the most potent inhibitor of HIV-1 RT DNA polymerase RNA-dependent and Ribonuclease H with IC50 values of 0.26 and 0.33 μg/mL, respectively. The LC-DAD metabolic profile showed that ethanolic leaves extract contains high levels of quercetin derivatives. This study suggests that Euphorbia characias extracts represent a good source of natural bioactive compounds which could be useful for pharmaceutical application as well as in food system for the prevention of the growth of food-borne bacteria and to extend the shelf-life of processed foods.

  5. Antiproliferative activity of extracts of Euphorbia tirucalli L ...

    African Journals Online (AJOL)

    Specifically, a prescription of six drops of E. tirucalli latex .... pressure of 0.5 - 1.0 bar, capillary voltage of 3.0 -. 3.5 kV, and transfer ..... d), which permit unrestricted use, distribution, ... compounds in atrue boiling point distillation system using.

  6. [Prevention of adverse effects in latex allergic patients: organizing a latex safe operating theatre].

    Science.gov (United States)

    Bonalumi, Sabrina; Barbonaglia, Patrizia; Bertocchi, Carmen

    2006-01-01

    In 2001 the General Health Direction of Region Lombardia approved (decree n. 22303) a guideline for the prevention of latex allergic reactions in patients and health care workers. This document provides general recommendations in order to standardize behaviors in regional health care facilities. The reason is due to a rise in the incident of reactions to latex products in the last 20 years. Nowadays the prevalence is higher in certain risk groups (subjected to frequent and repeated exposures) rather than the general population. The aim of the project was to organize a latex safe operating theatre in the Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena of Milan (Fondazione) and to standardize behaviors in order to prevent adverse effects in latex allergic patients. Thanks to the literature review and the creation of a multidisciplinar team, we produced a protocol. Therefore, we requested manufacturers the certification of the latex content of their products. Results and conclusion. When latex allergic patients need to undergone surgery in our hospital, a latex safe operating theatre is organized by personnel following a multidisciplinar protocol. No allergic reactions were experienced during surgical procedures after the creation of an environment as free as possible from latex contamination. The project will involve an emergency room, one room or more of a ward and of the outpatients department.

  7. Analysis of the essential oil from the dried leaves of Euphorbia hirta ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... Euphorbia hirta Linn (Euphorbiaceae), a potential medication for asthma. Modupe ... more popularity than ever before as sales figures in some countries, for example the ... obstruction and also cause an associated increase in.

  8. Radiation vulcanization of Philippine natural rubber latex

    International Nuclear Information System (INIS)

    Dela Rosa, A.M.; Abad, L.V.; Sta.Ana-Relleve, L.P.; Tranquilan-Aranilla, C.O.; Pascual, C.L.

    1996-01-01

    The response of Philippine natural rubber latex to irradiation vulcanization and the stability of the irradiated natural rubber latex (INRL) upon storage and aging were investigated. Commercially available high ammonia (HA) concentrated latices obtained from various rubber plantations in Mindanao island were treated with 5 phr of n-butyl acrylate (nBA), and gamma-irradiated at the PNRI 60 Co irradiation facility at a dose rate of 2.57 kGy/hr. Unirradiated cast latex films gave different green strengths which varied from 2-11 MPa. Cast films from INRL exhibited maximum tensile strengths were obtained from cast films with low Mg and high nitrogen contents. Thermal analysis using thermogravimetry (TG) revealed one major decomposition product at 374 o -377 o C. Its rate of decomposition decreased to a minimum at 15 kGy, then increased as radiation dose was increased. This trend correlated well with the tensile strength measurements. The stability of the INRL upon storage and aging is an essential parameter to the rubbe latex industry. For storage studies, INRL was stored for various periods of time. It was found that the pH and total solids content of the stored INRL did not change significantly after 12 months of storage; the MST values remained at above 1000 seconds, and the viscosity decreased with time. The cast films exhibited a decline in tensile strength, modulus 300% , and crosslinking density upon storage. While there were observed changes in the physical properties of the INRL during the storage period, the data indicate that these properties were within values acceptable to the latex industry. Tests on the aging properties of INRL films were undertaken. It was shown that among the chemical antioxidants presently used by the latex industry, TNPP demonstrated the highest antioxidant property, followed by Antage DAHQ and Vulcanox BKF. Our data indicate that the natural rubber latex produced and processed in the Philippines is suited for radiation vulcanization

  9. Irritant and allergenic potential of some latex producing Indian plants

    Directory of Open Access Journals (Sweden)

    J S Pasricha

    1990-01-01

    Full Text Available The iatex exuding from the freshly sliced stems/leaves of 11 Indian plants was tested on 10 volunteers each by the open patch test and in 5 volunteers each by the 48 hour occluded patch test technique. In the open patch test, there was no reaction with (1 calotropis procera, (2 Alstonia scholaris,(3 Euphorbia splendens, (4 Euphorbia clarkina (5 Nerium indicum, and (6 Padilanthus tithymaloides (Green and white leaf variety, while mild reactions were observed with Euphorbia pulcherrima in 3 volunteers, Ficus elastida in 2 volunteers, and Pedilanthus tithymaloidas (Green leaf variety and Plumeria indica in one volunteer each Sapium sebiferum on the other hand produced severe itching, burning and erythema in all the 10 volunteers. The 48 hour occluded patch test produced definite reactions with Pedilanthus tithymaloides (Green leaf varietyin 2 cases and calotropis procera and Euphorbia clarkina in 1 case each. Sapium sebiferum on the other hand produced cauterization type of reactions in all the cases.

  10. Anti-ulcer activity of Synadenium grantii latex

    Directory of Open Access Journals (Sweden)

    Larissa L. G. Costa

    2012-10-01

    Full Text Available Synadenium grantii Hook f., Euphorbiaceae, is popularly known as leitosinha or janaúba. The diluted latex (18 drops/L of water is commonly used in the south of Brazil to treat gastric disturbances. This study evaluated phytochemical screening and toxicity using Artemia salina Leach of crude bark extract and also latex. The toxicity and the anti-ulcer activity of S. grantii latex were also tested in rats. Phytochemical results showed presence of tannins, terpenes, unsaponificable substances, coumarins and anthraquinones in the crude bark extract and terpenes in the latex. Gas chromatography-mass spectrometry (GC-MS analysis demonstrated the presence of diterpene tigliane esters in the latex, identified as 12-deoxyphorbol-13-(2-metilpropionate and phorbol 12,13,20-triacetate. The toxicity results using A. salina presented CL50 26.58μg/mL and CL50 778.66μg/mL, for the latex and the crude bark extract respectively. The toxicological hepatic parameters of the diluted latex were not different to the control group (p<0.05. The eosinophils cells showed an increase in both the diluted and pure latex groups. The pure latex showed gastric protection of 90% (p<0.05 and the diluted latex showed 6% compared to the negative control. Therefore, our data indicate that S. grantii latex, under research conditions presented gastric protection. Pure latex showed more toxicity than the diluted latex.

  11. Experimental study on the drying of natural latex medical gloves

    Science.gov (United States)

    Chankrachang, Mano; Yongyingsakthavorn, Pisit; Tohsan, Atitaya; Nontakaew, Udomkiat

    2018-01-01

    The purpose of this research was to study latex film drying at 70 °C using a laboratory drying oven. Two different total solid content (TSC) latex compounds, which 45% TSC and 35% TSC were used. The undried latex films were prepared according to the common procedures used in latex gloves manufacturers, that is, by dry coagulant dipping process. The experimental results such as initial moisture content, the amount of moisture and drying time of latex films in each latex compound formula were determined. After that, the results were projected to calculate on the production capacity expand by 1 million piece/day of natural latex medical gloves. Finally, the rate of moisture entering the latex drying oven and the energy consumption of the drying oven were estimated. The results indicated that when the 35% TSC of latex compound was used. The initial moisture content of latex film was higher than 45% TSC of latex compound about 7%. The drying time of 35% TSC was longer than 45% TSC for 2.5 min and consume more energy about 10%. As a result, the 45% TSC latex compound was the better way to saving energy and managing humidity in the production line. Therefore, it was found to very useful to an approximate design length and size of actual of latex drying oven and the rate of moisture entering the oven as well.

  12. Recombinant albumin monolayers on latex particles.

    Science.gov (United States)

    Sofińska, Kamila; Adamczyk, Zbigniew; Kujda, Marta; Nattich-Rak, Małgorzata

    2014-01-14

    The adsorption of recombinant human serum albumin (rHSA) on negatively charged polystyrene latex micro-particles was studied at pH 3.5 and the NaCl concentration range of 10(-3) to 0.15 M. The electrophoretic mobility of latex monotonically increased with the albumin concentration in the suspension. The coverage of adsorbed albumin was quantitatively determined using the depletion method, where the residual protein concentration was determined by electrokinetic measurements and AFM imaging. It was shown that albumin adsorption was irreversible. Its maximum coverage on latex varied between 0.7 mg m(-2) for 10(-3) M NaCl to 1.3 mg m(-2) for 0.15 M NaCl. The latter value matches the maximum coverage previously determined for human serum albumin on mica using the streaming potential method. The increase in the maximum coverage was interpreted in terms of reduced electrostatic repulsion among adsorbed molecules. These facts confirm that albumin adsorption at pH 3.5 is governed by electrostatic interactions and proceeds analogously to colloid particle deposition. The stability of albumin monolayers was measured in additional experiments where changes in the latex electrophoretic mobility and the concentration of free albumin in solutions were monitored over prolonged time periods. Based on these experimental data, a robust procedure of preparing albumin monolayers on latex particles of well-controlled coverage and molecule distribution was proposed.

  13. The Morphology of Emulsion Polymerized Latex Particles

    Science.gov (United States)

    Wignall, G. D.; Ramakrishnan, V. R.; Linne, M. A.; Klein, A.; Sperling, L. H.; Wai, M. P.; Gelman, R. A.; Fatica, M. G.; Hoerl, R. H.; Fisher, L. W.

    1987-11-01

    Under monomer starved feed conditions, emulsion polymerization of perdeuterated methyl methacrylate and styrene in the presence of preformed polymethylmethacrylate latexes resulted in particles with a core-shell morphology, as determined by small-angle neutron scattering (SANS) analysis for a hollow sphere. The locus of polymerization of the added deuterated monomer is therefore at the particle surface. In similar measurements a statistical copolymer of styrene and methyl methacrylate was used as seed particles for further polymerization of trideuteromethyl methacrylate. The resulting polymer latex was again shown to have a core-shell morphological structure as determined by SANS. SANS experiments were also undertaken on polystyrene latexes polymerized by equilibrium swelling methods, with deuterated polymer forming the first or second step. The experiments covered a molecular weight range of 6 x 10{sup 4} 10{sup 6} the molecular weights are consistent with the experimental errors, indicating that the deuterium labeled molecules are randomly distributed in the latex. These results led to the finding that the polymer chains were constrained in the latex particles by factors of 2 to 4 from the relaxed coil dimensions. For M molecules. Several models were examined, including the possible development of core-shell structures at lower molecular weights.

  14. Extraction, isolation and identification of flavonoid from Euphorbia neriifolia leaves

    Directory of Open Access Journals (Sweden)

    Veena Sharma

    2017-05-01

    Full Text Available The flavonoids contained in Euphorbia neriifolia leaves were extracted, identified and characterized. Direct and sequential soxhlet extraction and its concentrated fractions were subjected to thin layer chromatography and high performance thin layer chromatography. The results showed that maximum yield of the flavonoid (6.53 g was obtained from ethanolic extract. The Rf value of isolated flavonoid and phytochemical screening has been compared with standard Quercetin. Characterization of isolated flavonoid was done by IR, 1H NMR, and MS. On the basis of chemical and spectral analysis structure was elucidated as 2-(3,4-dihydroxy-5-methoxy-phenyl-3,5-dihydroxy-6,7-dimethoxychromen-4-one, a flavonoid. This compound was isolated for the first time from this plant.

  15. Home Healthcare Workers: How to Prevent Latex Allergies

    Science.gov (United States)

    ... can help prevent allergic reactions for both home healthcare workers and their clients. LATEX EXPOSURE REACTIONS Three ... being used). • Inform your employer and your personal healthcare professionals that you have latex allergy. • Wear a ...

  16. Angiogenic activity of Synadenium umbellatum Pax latex

    Directory of Open Access Journals (Sweden)

    PR. Melo-Reis

    Full Text Available Synadenium umbellatum Pax, popularly known as "cola-nota", is a medicinal plant that grows in tropical regions. Latex of this plant is used to treat various diseases such as diabetes mellitus, Hansen´s disease, tripanosomiases, leukemia and several malignant tumors. In the present study, the angiogenic activity of S. umbellatum latex was evaluated using the chick embryo chorioallantoic membrane (CAM assay. Results showed significant increase of the vascular net (p < 0.05 compared to the negative control (H2O. The histological analysis was in accordance with the results obtained. In conclusion, our data indicate that S. umbellatum latex, under the conditions of this research, presented angiogenic effect.

  17. Radiation response of Philippine natural rubber latex

    International Nuclear Information System (INIS)

    Dela Rosa, A.M.; Abad, L.V.; Ana-Relleve, L.S.; Tranquilan-Aranilla, C.; Pascual, C.L.

    1998-01-01

    Our earlier work has shown that the natural rubber latex (NRL) produced and processed in the Philippines is suited for radiation vulcanization. The cast films from NRL with 50% TSC exhibited maximum tensile strengths of 25-32 MPa at 15 kGy, which is the vulcanization dose or Dv. In the manufacture of dipped NRL products, certain specifications such as %TSC, protein content and tensile properties, must be met to ensure an acceptable product. For radiation vulcanization of natural rubber latex (RVNRL) to be accepted as an alternative process, it must also meet the requirements. Thus, this paper presents additional data on the radiation response of local NRL at different total solids contents (TSC), leachable proteins from NRL films as a function of dose, and the thermal activities of irradiated natural rubber latex (INRL). Different formulations of NRL showed varying tolerances to nBA. Data showed that as %TSC increases, the maximum concentration of nBA that can be added without affecting the stability of the latex decreases. The Dv increases as the %TSC increases and the nBA content decreases. This difference in response may be attributed to a lower concentration of nBA in formulations with higher %TSC. These data indicate that the parameters in the radiation treatment will be dictated by the intended applications of INRL. The thermogravimetric data showed greater stability of INRL to thermal oxidation relative to the unirradiated NRL, which correlates directly with the tensile properties of the INRL. A radiation dose of 10 kGy increased the amount of proteins leached from cast latex films. The amount of extractable proteins did not increase significantly at higher doses. The SDS PAGE analysis of the extractable proteins from unirradiated latex film showed distinct bands. An additional band at 60 Kda appeared at 10 kGy. All these bands became diffuse at higher doses, indicating the radiolysis of the proteins

  18. CHARACTERIZATION AND RECYCLING OF WASTE WATER FROM GUAYULE LATEX EXTRACTION

    Science.gov (United States)

    Guayule commercialization for latex production to be used in medical products and other applications is now a reality. Currently, waste water following latex extraction is discharged into evaporation ponds. As commercialization reaches full scale, the liquid waste stream from latex extraction will b...

  19. Plant latex lipase as biocatalysts for biodiesel production | Mazou ...

    African Journals Online (AJOL)

    Plant latex lipase as biocatalysts for biodiesel production. ... This paper provides an overview regarding the main aspects of latex, such as the reactions catalyzed, physiological functions, specificities, sources and their industrial applications. Keywords: Plant latex, lipase, Transesterification, purification, biodiesel ...

  20. Thermodynamics of swelling of latex particles with two monomers

    NARCIS (Netherlands)

    Maxwell, I.A.; Kurja, J.; van Doremaele, G.H.J.; German, A.L.

    1992-01-01

    The partitioning of 2 monomers between the latex particle, monomer droplet, and aq. phases of an emulsion polymer latex are measured at satn. swelling of the latex particle phase (corresponding to intervals I and II of an emulsion polymn.). The monomer (Me acrylate, Bu acrylate, styrene) and polymer

  1. Emotion with tears decreases allergic responses to latex in atopic eczema patients with latex allergy.

    Science.gov (United States)

    Kimata, Hajime

    2006-07-01

    Allergic responses are enhanced by stress, whereas they are reduced by laughter in atopic eczema patients. Emotion with tears decreases plasma IL-6 levels in patients with rheumatoid arthritis. Thus, the effect of emotion with tears on allergic responses in patients with atopic eczema was studied. Sixty patients with atopic eczema having latex allergy viewed both the weather information video and the heart-warming movie, Kramer vs. Kramer. Just before and immediately after viewing each video, allergic responses to latex were measured. Viewing the weather information video did not cause emotion with tears in any patients, and it failed to modulate allergic responses. In contrast, viewing Kramer vs. Kramer caused emotion with tears in 44 of 60 patients, and it reduced allergic skin wheal responses to latex and latex-specific IgE production in them. Emotion with tears reduced allergic responses, and it may be useful in the treatment of allergic diseases.

  2. Exploiting epoxidized natural rubber latex (ENRL) as a starting raw material for latex-based products

    Science.gov (United States)

    Siti Nor Qamarina, M.; Fatimah Rubaizah, M. R.; Nurul Suhaira, A.; Norhanifah, M. Y.

    2017-12-01

    Epoxidized natural rubber latex (ENRL) is a chemically modified natural rubber latex produced from epoxidation process that involves usage of organic peracids. Conversion of the ENRL into dry rubber products has been known to exhibit many beneficial properties, however limited published works were found on diversifiying the ENRL latex-based products applications. In this preliminary work, different source of raw materials and neutralization systems were investigated. The objective was to explore possibilities in producing distinctive ENRL. Findings have demonstrated that different source of raw materials and neutralization systems influenced the typical ENRL specifications, stability behavior and particle size distribution. Morphological observations performed on these ENRL systems appeared to agree with the ENRL characteristics achieved. Since experimenting these two main factors resulted in encouraging ENRL findings, detailed work shall be further scrutinized to search for an optimum condition in producing marketable ENRL specifically for latex-based products applications.

  3. Preparation of highly stabilised natural rubber latex for radiation vulcanisation

    International Nuclear Information System (INIS)

    Kulatunge, S.S.; Nadarajah, M.; Kalyani, N.M.V.; Chandralal, H.N.K.K.; Devendra, R.

    1996-01-01

    There is a bright future for radiation vulcanised natural rubber latex (RVNRL) but there are problems in manufacturing it as the centrifuged latex to be used for radiation has to be kept for at least a month or sometimes even three to six months before adding the sensitisers and even then the latex sometimes coagulates on adding the sensitisers. This paper describes a process by which the latex can be stabilised by addition of an anionic soap before centrifuging so that it has a high mechanical stability and hence can be used even within one week of the manufacture of the centrifuged latex

  4. CHEMICAL EXAMINATION OF JACK TREE LATEX AND

    Indian Academy of Sciences (India)

    and on Saponification yielded fatty acids, Volatile as well as non-volatile. The unsaponifiable portion on repeated crystallisation provided a crystal- line, sharp melting compound which was identified as artostenone? from a. Latex (200 c.c.). ത്ത min- pe. Coagulum (A) Aqueous alcoholic solution (B). Acetone or ethyl acetate ...

  5. Application of recombinant latex allergens in diagnostics of occupational latex allergy

    Directory of Open Access Journals (Sweden)

    Ewa Nowakowska-Świrta

    2015-02-01

    Full Text Available Over many years, allergy to natural rubber latex has been a major problem among health care workers (HCW. The diagnosis of occupational allergy requires methods of high diagnostic accuracy in view of certification implications (e.g., a sick worker quits a job. With the development of molecular methods, the frequency of application of recombinant allergens in the diagnostics of allergic diseases continues to increase. This paper reviews the applicability of laboratory tests which use recombinant allergens in the diagnostics of occupational allergy. The diagnosis of latex allergy is based on the presence of clinical symptoms linked with exposure to latex allergens, positive skin prick tests and detection of specific IgE antibodies to latex in serum. Moreover, in some cases specific challenge tests are conducted. The analysis of literature indicates that applying the panel of recombinant latex allergens in diagnostic tests, cross-reactivity can very likely be excluded and/or sensitization can be confirmed without the need for specific challenge tests, which in case of latex allergens carries a potential risk of generalized reactions. Med Pr 2015;66(1:85–97

  6. Radiation vulcanization of Philippine natural rubber latex

    International Nuclear Information System (INIS)

    Dela Rosa, Alumanda M.; Abad, Lucille V.; Sta, Lorna P.; Ana-Relleve; Tranquilan-Aranilla, Charito O.; Pascual, Cristina L.

    1996-01-01

    The response of Philippine natural rubber latex to radiation vulcanization and the stability of the irradiated natural rubber latex (INRL) upon storage and aging were investigated. Commercially available high ammonia (HA) concentrated lattices obtained from various rubber plantations in Mindanao Island were treated with 5 phr of n-butyl acrylate (nBA), and gamma-irradiated at the PNRI sup 60 Co irradiation facility at dose rate of 2.57 KGy/hr. Unirradiated cast latex films gave different green strength which varied from 2 - 11 MPa. Cast films from INRL exhibited maximum tensile strengths of 25 - 32 MPa at a radiation dose of 15 kGy. Higher tensile strengths were obtained from cast films with low Mg and high nitrogen contents. Thermal analysis using thermogravimetry (TG) revealed one major decomposition product at 374 degree C - 377 degree C. Its rate of decomposition decreased to a minimum at 15 kGy, then increased as radiation dose increased. This trend correlated well with the tensile strength measurements. The stability of the INRL upon storage and aging is an essential parameter to the rubber latex industry. For storage studies, INRL was stored for various periods of time. It was found that the pH and total solids content of the stored INRL did not change significantly after 12 months of storage; the MST values remained at above 100 seconds, and the viscosity decreased with time. The cast films exhibited a decline in tensile strength, modulus 300% and crosslinking density upon storage. While there were observed changes in the physical properties of the IRNL during the storage period, the data indicate that these properties were within values acceptable to the latex industry. Tests on the aging properties of INRL film were undertaken. It was shown that among the chemical antioxidants presently used by the latex industry. TNPP demonstrated the highest antioxidant property, followed by Antage DAHQ and Vulcanox BKF. Our data indicate that the natural rubber latex

  7. Effect of Euphorbia hirta plant leaf extract on immunostimulant response of Aeromonas hydrophila infected Cyprinus carpio

    Science.gov (United States)

    Sukumaran, NatarajaPillai

    2014-01-01

    The main objective of the present study is to improve the immune power of Cyprinus carpio by using Euphorbia hirta plant leaf extract as immunostimulants. The haematological, immunological and enzymatic studies were conducted on the medicated fish infected with Aeromonas hydrophila pathogen. The results obtained from the haematological studies show that the RBC count, WBC count and haemoglobin content were increased in the infected fish at higher concentration of leaf extract. The feeds with leaf extract of Euphorbia hirta were able to stimulate the specific immune response by increasing the titre value of antibody. It was able to stimulate the antibody production only up to the 5th day, when fed with higher concentrations of (25 g and 50 g) plant leaf extract. The plant extract showed non-specific immune responses such as lysozyme activity, phagocytic ratio, NBT assay, etc. at higher concentration (50 g) and in the same concentration (50 g), the leaf extract of Euphorbia hirta significantly eliminated the pathogen in blood and kidney. It was observed that fish have survival percentage significantly at higher concentration (50 g) of Euphorbia hirta, when compared with the control. The obtained results are statistically significant at P < 0.05 and P < 0.01 levels. This research work suggests that the plant Euphorbia hirta has immunostimulant activity by stimulating both specific and non-specific immunity at higher concentrations. PMID:25405077

  8. Selected Enzyme Inhibitory Effects of Euphorbia characias Extracts

    Directory of Open Access Journals (Sweden)

    Antonella Fais

    2018-01-01

    Full Text Available Extracts of aerial part of Euphorbia characias were examined to check potential inhibitors for three selected enzymes involved in several metabolic disorders. Water and ethanol extracts from leaves and flowers showed in vitro inhibitory activity toward α-amylase, α-glucosidase, and xanthine oxidase. IC50 values were calculated for all the extracts and the ethanolic extracts were found to exert the best effect. In particular, for the α-glucosidase activity, the extracts resulted to be 100-fold more active than the standard inhibitor. The inhibition mode was investigated by Lineweaver-Burk plot analysis. E. characias extracts display different inhibition behaviors toward the three enzymes acting as uncompetitive, noncompetitive, and mixed-type inhibitors. Moreover, ethanolic extracts of E. characias showed no cytotoxic activity and exhibited antioxidant capacity in a cellular model. The LC-DAD metabolic profile was also performed and it showed that leaves and flowers extracts contain high levels of quercetin derivatives. The results suggest that E. characias could be a promising source of natural inhibitors of the enzymes involved in carbohydrate uptake disorders and oxidative stress.

  9. The effects of Euphorbia hirta on the ultrastructure of the murine liver, kidney and aorta

    Science.gov (United States)

    WONG, J.Y.R.; CHEN, Y.S.; CHAKRAVARTHI, S.; JUDSON, J.P.; L., SANTHANA RAJ; ER, H.M.

    2013-01-01

    Euphorbia hirta is widely used in traditional remedies and has been used cross-culturally for generations against maladies such as asthma, skin ailments and hypertension. Previous studies have demonstrated that Euphorbia hirta has antibacterial activity, and have also indicated certain antimolluscidal, antimalarial and anti-inflammatory properties, the latter of which have been suggested to be more pronounced than those of the rheumatological drug, etanercept. To date, no studies have identified the anatomical effects of this herb on the organs of test animals. This study aimed to identify the effects of Euphorbia hirta on the ultrastructure of the murine liver, kidney and aorta. A total of 32 adult male Sprague-Dawley rats were divided into four groups; three groups were fed with aqueous extracts of Euphorbia hirta at doses of 1, 10 and 50 mg/kg, respectively, every alternate day for 50 days, while one group served as a control. The animals were later sacrificed and the liver, kidney and aorta harvested for examination by electron microscopy. The aorta showed no ultrastructural changes across the groups. Renal and hepatic tissue from the treated groups demonstrated dose-dependent injuries, which showed architectural damage beginning in the nuclei and spreading outwards. Taking into consideration the properties of Euphorbia hirta that have been described in previous studies, in addition to the results from the present study, it appears that the herb may exhibit similar effects to those of the quinolone group of antibiotics. Further in-depth investigations are required into the potential effects of Euphorbia hirta, deleterious and otherwise. PMID:24223653

  10. Cement-latex grouting mortar for cementing boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Kateev, I S; Golyshkina, L A; Gorbunova, I V; Kurochkin, B M; Vakula, Ya V

    1980-01-01

    The need for the development of cement-latex grouting mortar for the purpose of separating strata when reinforcing boreholes at deposits in the Tatar Associated SSR is evaluated. Results of studies of the physical and mechanical properties of cement-latex grouting mortar systems (mortar plus brick) are presented. Formulas for preparing cement-latex grouting mortor are evaluated and results of industrial tests of such mortars shown.

  11. Effect of Amphiphilic Alkyl Chain Length Upon Purified LATEX Stability

    International Nuclear Information System (INIS)

    Amira Amir Hassan; Amir Hashim Mohd Yatim

    2015-01-01

    Rubber particles in purified latex (PL) are stabilized by a film of protein and fatty acid soap (surfactant). Saturated straight-chain fatty acid soaps can assist an enhancement of latex stability. However, whether the alkyl chain length plays an important role in increasing the stability is still an issue. The aim of this study is to investigate the effect of alkyl chain length of anionic surfactant on the stability of purified latex. The fatty acid soap of decanoate (9), laurate (11), sodium dodecyl sulphate (SDS) (12) and palmitate (15) were used. The numbers in parentheses indicating the number of carbon present in alkyl chain of the soap. The results showed that the impact of alkyl chain length on the stability of latex is in the order of laurate > decanoate > SDS > palmitate > purified latex accordingly. The alkyl chain length does giving a significant effect on latex stability after longer stirring time. The particle size of latex with the presence of surfactant is greater compare to a single particle itself due to extension of particles diameter. Thus suitable interaction of the nonpolar tail of surfactant with the hydrophobic regions of latex surface played a major role in maintaining a stable latex system. (author)

  12. Aspects of Degradability and Aging of Natural Rubber Latex Films Obtained by Induced Ionizing Radiation Processes of Latex Vulcanization

    International Nuclear Information System (INIS)

    Parra, D. F.

    2006-01-01

    This study refers to the degradability of NRLF, natural rubber latex films, obtained by ionizing radiation. Three types of NRLF were prepared: irradiated latex, irradiated latex with about 1% of soy lecithin and sulfur-vulcanized latex, by cold vulcanization process. The films were buried in vases of two different kinds of soil: common soil and common soil with earthworm humus. Fast aging tests in laboratory with exposition to ultraviolet rays were done in irradiated latex films and irradiated latex films with soy lecithin. The results obtained after ten months of tests with buried films agree with the results of the fast aging tests, showing singularities of each type of soil and each kind of latex process. It also shows how weather inclemency can induce the films degradation process. The sulfur-vulcanized films were weakly degraded when buried. The films with lecithin and buried in vase with only common soil showed the biggest mass loss, but the films with lecithin buried in vases with common earthworm humus and soil increased their weigh and dimensions due to fungi formation. The irradiated latex films are more degradable then the sulfur-vulcanized films. The irradiated latex film, unlike the sulfur vulcanized film, showed high fungi colonization when buried. We conclude that the irradiated latex films are more easily biodegradable than the sulfur vulcanized latex films. The biodegradability increases with the addition of small amounts of soy lecithin (∼1%). The mechanical resistance of the buried films decreased related to the non-buried ones, proving that the outdoor aging in soil and the presence of fungi in the films can modify the mechanical properties of the irradiated latex owing to the biodegradation

  13. New Compounds from Euphorbia helioscopia and Absolute Configuration Determination by Computational Methods

    International Nuclear Information System (INIS)

    He, Jiangbo; Zhu, Hua Jie; Luo, Gui Fen; Li, Yan; Cheng, Yong Xian; Chen, Hao; Chen, Shaopeng; Lu, Xin; Zhou, Guochun; Liu, Guang Ming

    2010-01-01

    The whole plant of Euphorbia helioscopia is an important traditional Chinese medicine. Fom its BuOH soluble extract, one new lactam, three new terpenoids including a new naturally occurring compound, and three known compounds were isolated. Their structures were identified by spectroscopic evidences. In particular, the absolute configurations of side chain of compounds 1 and 2 were determined using computational methods

  14. Fungi and insects associated with Euphorbia ingens die-off in South ...

    African Journals Online (AJOL)

    Euphorbia ingens, landmark succulent trees in savannas of South Africa, have been dying in large numbers over the last 10–15 years. Initial studies conducted in the Limpopo province of South Africa revealed a diverse group of biotic agents including fungi, beetles and moths associated with dying trees, but due to the ...

  15. Development and survival of Aulacorthum solani, Macrosiphum euphorbiae and Uroleucon ambrosiae at six temperatures

    NARCIS (Netherlands)

    Conti, de B.F.; Bueno, V.H.P.; Sampaio, M.V.; Lenteren, van J.C.

    2011-01-01

    Temperature is one of the most important factors in determining the survival and developmental rate of aphids. The aim of this study was to evaluate the developmental time and survival of the aphid species Aulacorthum solani (Kaltenbach), Macrosiphum euphorbiae (Thomas) and Uroleucon ambrosiae

  16. Beheersing en bestrijding van Botrytis cinerea en van Penicillium in Euphorbia fulgens

    NARCIS (Netherlands)

    Wubben, J.P.; Hazendonk, A.; Bosker, I.; Slootweg, C.; Hoope, ten M.

    2002-01-01

    De bloeiwijze van Euphorbia fulgens kent twee belangrijke schimmelbelagers, die problemen in de teelt veroorzaken: Botrytis cinerea en Penicillium. B. cinerea geeft schade in de vorm van smet of pokken, die op de bloemblaadjes verschijnen. Dit zijn kleine donkerbruine/zwarte plekjes van ongeveer 1

  17. Repellence and toxicity of plant essential oils to the potato aphid, Macrosiphum euphorbiae

    NARCIS (Netherlands)

    Munneke, M.E.; Bruin, de A.; Moskal, J.R.; Tol, van R.W.H.M.

    2004-01-01

    Several plant essential oils were tested for their effect on behaviour and mortality of M. euphorbiae. Olfactory and contact experiments were performed to study these effects. We found that host plant and formulation of the different oils have a strong influence on repellence and mortality of the

  18. Demonstration of the economic feasibility of plant tissue culture for jojoba (Simmondsia chinensis) and Euphorbia spp

    Energy Technology Data Exchange (ETDEWEB)

    Sluis, C.

    1980-09-01

    The economic feasibility of plant tissue culture was demonstrated as applied to two plants: jojoba (Simmondsia chinensis) and Euphorbia spp. The gopher weed (Euphorbia lathyris) was selected as the species of Euphorbia to research due to the interest in this plant as a potential source of hydrocarbon-like compounds. High yield female selections of jojoba were chosen from native stands and were researched to determine the economic feasibility of mass producing these plants via a tissue culture micropropagation program. The female jojoba selection was successfully mass produced through tissue culture. Modifications in initiation techniques, as well as in multiplication media and rooting parameters, were necessary to apply the tissue culture system, which had been developed for juvenile seedling tissue, to mature jojobas. Since prior attempts at transfer of tissue cultured plantlets were unsuccessful, transfer research was a major part of the project and has resulted in a system for transfer of rooted jojoba plantlets to soil. Euphorbia lathyris was successfully cultured using shoot tip cultures. Media and procedures were established for culture initiation, multiplication of shoots, callus induction and growth, and root initiation. Well-developed root systems were not attained and root initiation percentages should be increased if the system is to become commercially feasible.

  19. Inoculation of cyclamen (Cyclamen persicum) and poinsettia (Euphorbia pulcherrima) with arbuscular mycorrhizal fungi and Trichoderma harzianum

    Czech Academy of Sciences Publication Activity Database

    Dubský, M.; Šrámek, F.; Vosátka, Miroslav

    2002-01-01

    Roč. 48, č. 2 (2002), s. 63-68 ISSN 0370-663X Institutional research plan: CEZ:AV0Z6005908 Keywords : Cyclamen persicum * Euphorbia pulcherrima * inoculation Subject RIV: EF - Botanics Impact factor: 0.333, year: 2002

  20. Follow-up Study of Latex-allergic Health Care Workers in Japan

    Directory of Open Access Journals (Sweden)

    Akiko Yagami

    2006-01-01

    Conclusions: After avoiding latex products and following our educational suggestions, the patients' allergy symptoms had generally improved. This indicates that our countermeasures against latex allergy were largely successful.

  1. [Latex allergy in a paediatric hospital. Characteristics and risk factors].

    Science.gov (United States)

    Bailey, Michael; Norambuena, Ximena; Roizen, Gigia; Rodríguez, Jorge; Quezada, Arnoldo

    The prevalence of latex sensitisation varies according to the population studied. There are various risk factors that increase latex sensitisation, such as genetic risk, atopy, and multiple surgeries. To characterise patients referred to an Immunology Unit with suspected latex allergy, and to analyse their clinical features and risk factors. A retrospective, descriptive study was conducted on children suspected of latex allergy. Their medical records were reviewed in order to assess symptoms with contact or exposure to latex materials. Known risk factors to latex sensitisation, such as pathologies requiring repeated surgery (spina bifida, myelomeningocele, scoliosis and nephro-urological alterations), atopy (rhinitis, asthma, atopic dermatitis) were investigated. A prick test and/or specific IgE to latex were also performed. A multivariate logistic regression model was performed to find associations between symptoms triggered by exposure to latex with underlying diseases and other risk conditions. A total of 106 patients were enrolled in the study, of whom 50 were evaluable. At diagnosis 96% of patients were older than five years. Most of the risk factors described were observable in these patients, such as multiple surgeries, neurological and nephro-urological malformations, surgery before one year-old, and repeated bladder catheterisation. After latex exposure, mucous cutaneous manifestations were the most common (52%), followed by respiratory symptoms (36%). All patients were sensitised and allergic to latex. Latex allergy is a significant problem in children with risk factors. The results shown in this study raise important challenges for preventive measures and awareness. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Wan Manshol bin Wan Zin; Norjanah binti Mohid

    1994-01-01

    This paper describes the experimental techniques and the results of radiation vulcanization of natural rubber latex carried out on several high ammonia latices available in the country. The efficiency of various sensitisers and stabilisers used were evaluated in terms of the gamma radiation dose required to produce the maximum tensile strengths. The extent of crosslinking of RVNRL sample films were estimated by equilibrium swelling ratio measurements. The stability of pre-irradiated and post-irradiated samples were monitored using viscosity measurements as the parameter

  3. NMR relaxation times of natural rubber latex

    International Nuclear Information System (INIS)

    Harun, S.; Aziz, H.; Basir, Z.

    1994-01-01

    NMR relaxation times T sub 1 and T sub 2 of natural rubber latex have been measured at 25 degree C on a pulsed NMR spectrometer. The work focuses on the variation of the relaxation times with the amount of water content from 0% to 50%. The water content was adjusted by centrifuging and removing a certain amount of water from the sample. The data were analysed using a biexponential fitting procedure which yields simultaneously either T sub 1a and T sub 1b or T sub 2a and T sub 2b. The amount of solid was compared with the known amount of dry rubber content

  4. Antimalarial Anthrone and Chromone from the Leaf Latex of Aloe ...

    African Journals Online (AJOL)

    In Ethiopian traditional medicine, the leaf latex of Aloe debranan Chrstian is used for the treatment of several diseases including malaria. In an ongoing search for effective, safe and cheap antimalarial agents from plants, the leaf latex of A. debrana was tested for its in vivo antimalarial activity, in a 4-day suppressive assay ...

  5. Antimicrobial activity of latex silver nanoparticles using Calotropis procera

    Directory of Open Access Journals (Sweden)

    Nadia Hussein Mohamed

    2014-11-01

    Conclusions: It can be concluded that serum latex of Calotropis procera was found to display strong potential for the synthesis of AgNPs as antimicrobial agents through rapid reduction of silver ions (Ag+ to Ag0. The green synthesized AgNPs were found to show higher antimicrobial efficacy than crude latex.

  6. Installing fonts in LaTeX a user's experience

    NARCIS (Netherlands)

    Hanssen, F.T.Y.

    2003-01-01

    This paper presents a user's experience with installing fonts for use in LaTeX. It will be shown that it is not hard to make a standard Type 1 font work, if you use modern font installation software for LaTeX. All the steps necessary to install the example fonts will be shown. The example fonts used

  7. High concentrations of natural rubber latex allergens in gloves used ...

    African Journals Online (AJOL)

    Introduction. Gloves made of natural rubber latex (NRL) are commonly used by healthcare workers because of their good qualities. However, allergic reactions to latex allergens are still commonly reported. Objective. To measure the concentrations of Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02 allergens in gloves used by a ...

  8. Allergenicity of latex rubber products used in South African dental ...

    African Journals Online (AJOL)

    Fourteen latex examination gloves (powdered and non-powdered) and five dental rubber dams, representing 6 brands, from five dental academic institutions were analysed for latex allergens and total protein. Total protein content was determined using the BioRad DC protein assay kit and natural rubber allergen levels ...

  9. Rapid latex agglutination test for the serodiagnosis of human brucellosis

    NARCIS (Netherlands)

    Abdoel, Theresia H.; Smits, Henk L.

    2007-01-01

    We developed and evaluated a user-friendly latex agglutination assay for the serodiagnosis of human brucellosis. The assay was obtained by coating colored latex beads with Brucella lipopolysaccharides and drying of the activated beads onto white agglutination cards. Individual cards were sealed in a

  10. Syntheses of crosslinked latex nanoparticles using differential microemulsion polymerization

    Science.gov (United States)

    Hassmoro, N. F.; Rusop, M.; Abdullah, S.

    2013-06-01

    The differential microemulsion polymerization was used to synthesize latex nanoparticles. In this paper, 1, 3-butylene glycol dimethacrylate (1, 3-BGDMA) was used as a crosslinker respectively 1-5 weight% of monomer total. Butyl acrylate (BA), butyl methacrylate (BMA), and methacrylic acid (MAA) was used as the monomer. The thin film of latex nanoparticles were prepared by using spin coating method and have been dried at 100°C for 5 minutes. The amount of the crosslinker added in the polymerization was optimized and we found that the particle sizes fall in the range of 30-60 nm. The structural morphology of the uncrosslinked latex represented the most homogeneous image compared to the crosslinked latex. The effect of the amount of crosslinker on the particle sizes investigated by the Zeta-sizer Nano series while Atomic Force microscopy (AFM) was used to study the structural properties of latex nanoparticles.

  11. Syntheses of crosslinked latex nanoparticles using differential microemulsion polymerization

    International Nuclear Information System (INIS)

    Hassmoro, N F; Abdullah, S; Rusop, M

    2013-01-01

    The differential microemulsion polymerization was used to synthesize latex nanoparticles. In this paper, 1, 3-butylene glycol dimethacrylate (1, 3-BGDMA) was used as a crosslinker respectively 1–5 weight% of monomer total. Butyl acrylate (BA), butyl methacrylate (BMA), and methacrylic acid (MAA) was used as the monomer. The thin film of latex nanoparticles were prepared by using spin coating method and have been dried at 100°C for 5 minutes. The amount of the crosslinker added in the polymerization was optimized and we found that the particle sizes fall in the range of 30–60 nm. The structural morphology of the uncrosslinked latex represented the most homogeneous image compared to the crosslinked latex. The effect of the amount of crosslinker on the particle sizes investigated by the Zeta-sizer Nano series while Atomic Force microscopy (AFM) was used to study the structural properties of latex nanoparticles.

  12. Experimental investigation of the effect of latex solid/water ratio on latex modified co-matrix mechanical properties

    Directory of Open Access Journals (Sweden)

    Ahmed M. Diab

    2013-03-01

    Full Text Available Numerous researches were performed on latex modified concretes and associated properties, however; some vital factors were not given attention in previous works. This study focus on new factor which significantly affects the properties of latex modified cement paste, mortar or concrete. This factor is termed as ‘latex solid/water ratio’ which is defined herein as the ratio of weight of solid latex to weight of total water content of cement composite including the water in latex itself. The effect of this factor on some properties of cement paste, mortar and concrete were experimentally evaluated. Properties of cement paste include the produced calcium hydroxide and ettringite content during hydration process, while those of cement mortar take account of absorption and effect of temperature on compressive strength. Furthermore, the effect of this factor on the compressive and flexural strengths, modulus of elasticity, water penetration depth and drying shrinkage of concrete were explored. Based on experimental evidences, and spite of using different cement contents, sources of latex, water–cement ratios and slump values, it can be generally concluded that the latex solid/water ratio is a dominant factor affecting different properties of latex modified mortars and concrete.

  13. Growth analysis of three species weeds Euphorbia genus = Análise de crescimento de espécies daninhas do gênero Euphorbia

    Directory of Open Access Journals (Sweden)

    Débora Teresa Ferreira

    2017-06-01

    Full Text Available In sugarcane plantations, species of the genus Euphorbia are reported as weeds able to reduce productivity by up to 85%. Planning the correct strategies for controlling these plants requires knowledge of their biology and growth. The aim of this work therefore, was to evaluate the growth of three weed species of the genus Euphorbia occurring in sugarcane plantations. The study was carried out in a greenhouse, using a completely randomised experimental design in a scheme of lots subdivided over time, with five replications. The factors were three species of Euphorbia (E. heterophylla, E. hyssopifolia and E. hirta and 13 periods of evaluation 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91 and 98 days after sowing (DAS. Each evaluation measured plant height (PH, leaf area (LA, number of leaves (NL and total dry matter (TDM. From the mean values for shoot dry matter (SDM, TDM and LA, the absolute growth rate (AGR and relative growth rate (RGR, leaf area ratio (LAR, and leaf weight ratio (LWR were calculated. Data were submitted to analysis of variance and non-linear regression. E. heterophylla displayed greater PH up to 63 DAS, from this point E. hyssopifolia obtained greater height among the species under study. E. heterophylla was noteworthy for having a greater accumulation of LA, TDM and AGR among the studied species, followed by E. hyssopifolia and E. hirta. Maximum growth in the species under evaluation was at 77 DAS. Among the species, E. heterophylla displays greater growth and development. = Nos canaviais, espécies do gênero Euphorbia são relatadas como plantas daninhas capazes de reduzir a produtividade em até 85%. Para traçar estratégias corretas de controle dessas plantas é necessário o conhecimento tanto da sua biologia quanto do seu crescimento. Assim, objetivou-se com este trabalho avaliar o crescimento de três espécies daninhas do gênero Euphorbia ocorrentes nos canaviais. O estudo foi realizado em casa de vegeta

  14. The preparation of RVNRL using Malaysian-produced latexes

    International Nuclear Information System (INIS)

    Zin, W.M. bin W.; Mohid, N. bte; Hasan, J. bin; Noor, W.K.A. bte W.M.; Jaafar, Zulkifli

    1993-01-01

    This research project was carried out using latexes supplied by three of the suppliers in Malaysia. From the results of studies carried out in search of the best sensitiser for RVNRL preparation, the use of n-butyl acrylate (n-BA) as a sensitiser gave the most promising results. However, its use as a sensitiser is not universal to all latexes available in the country. The problem was overcome by using different formulations for different latexes. For the latex supplied by Golden Hope (Hytex), a combination of sensitisers i.e. n-BA plus 2-ethyl hexyl acrylate (2-EHA) with a 10% potassium hydroxide solution as the stabilizer, was required. Latex supplied by MARDEC (Matex), seemed to need only n-BA as the sensitiser. However, a stabilizer was still required and the use of a 10% KOH solution was found to be suitable. A large range of stabilizers and sensitisers were applicable to Guthrie latex. The use of n-BA as the sensitiser and potassium laurylic acid as the stabilizer seemed the most favourable formulation. All the results are discussed in the form of a correlation between dose and the tensile properties of RVNRL vulcanizates, equilibrium swelling ratio and standing time of the latex formulation. (author)

  15. The Synthesis and Modification of Nanosized Clickable Latex Particles

    KAUST Repository

    Almahdali, Sarah

    2013-05-01

    This research aims to add to the current knowledge available for miniemulsion polymerization reactions and to use this knowledge to synthesize multifunctional nanosized latex particles that have the potential to be used in catalysis. The physical properties of the latex can be adjusted to suit various environments due to the multiple functional groups present. For this research, styrene, pentafluorostyrene, azidomethyl styrene, pentafluorostyrene with azidomethyl styrene and pentafluorostyrene with styrene latexes were produced, and analyzed by dynamic light scattering. The latexes were synthesized using a miniemulsion polymerization technique found through this research. Potassium oleate and potassium 1,1,2,2,3,3,4,4-nonafluorobutane-1-sulfonate were used as surfactants during the miniemulsion polymerization reaction to synthesize pentafluorostyrene with azidomethyl styrene latex. Transmission electron microscopy data and dynamic light scattering data have been collected to analyze the structure of this latex, and it has been synthesized using a number of conditions, differing in reaction time, surfactant amount and sonication methods. We have also improved the solubility of the latex through a copper(I) catalyzed 1,3-dipolar azide-alkyne reaction, by clicking (polyethylene glycol)5000 onto the azide functional groups.

  16. Atividade residual de diuron, oxyfluorfen e prometryne no controle de Euphorbia heterophylla Residual activity of diuron, oxyfluorfen, and prometryne for Euphorbia heterophylla control

    OpenAIRE

    R.S. Oliveira Jr.; J.C. Carneiro; J. Constantin; G. Santos; A.C. Francischini; A.M. Oliveira Neto

    2012-01-01

    As aplicações de herbicidas em pré-emergência têm por finalidade a obtenção da atividade residual no início do ciclo das culturas. Assim, o objetivo deste trabalho foi avaliar a atividade residual dos herbicidas diuron, oxyfluorfen e prometryne, aplicados isoladamente ou em misturas, no controle de Euphorbia heterophylla. Oito experimentos foram conduzidos em casa de vegetação, aplicando-se doses dos herbicidas ou das misturas aos 30, 20, 10 e 0 dias antes da semeadura da planta daninha (DAS)...

  17. Size effects of latex nanomaterials on lung inflammation in mice

    International Nuclear Information System (INIS)

    Inoue, Ken-ichiro; Takano, Hirohisa; Yanagisawa, Rie; Koike, Eiko; Shimada, Akinori

    2009-01-01

    Effects of nano-sized materials (nanomaterials) on sensitive population have not been well elucidated. This study examined the effects of pulmonary exposure to (latex) nanomaterials on lung inflammation related to lipopolysaccharide (LPS) or allergen in mice, especially in terms of their size-dependency. In protocol 1, ICR male mice were divided into 8 experimental groups that intratracheally received a single exposure to vehicle, latex nanomaterials (250 μg/animal) with three sizes (25, 50, and 100 nm), LPS (75 μg/animal), or LPS plus latex nanomaterials. In protocol 2, ICR male mice were divided into 8 experimental groups that intratracheally received repeated exposure to vehicle, latex nanomaterials (100 μg/animal), allergen (ovalbumin: OVA; 1 μg/animal), or allergen plus latex nanomaterials. In protocol 1, latex nanomaterials with all sizes exacerbated lung inflammation elicited by LPS, showing an overall trend of amplified lung expressions of proinflammatory cytokines. Furthermore, LPS plus nanomaterials, especially with size less than 50 nm, significantly elevated circulatory levels of fibrinogen, macrophage chemoattractant protein-1, and keratinocyte-derived chemoattractant, and von Willebrand factor as compared with LPS alone. The enhancement tended overall to be greater with the smaller nanomaterials than with the larger ones. In protocol 2, latex nanomaterials with all sizes did not significantly enhance the pathophysiology of allergic asthma, characterized by eosinophilic lung inflammation and Igs production, although latex nanomaterials with less than 50 nm significantly induced/enhanced neutrophilic lung inflammation. These results suggest that latex nanomaterials differentially affect two types of (innate and adaptive immunity-dominant) lung inflammation

  18. Influence de quelques facteurs environnementaux sur la germination d'Euphorbia heterophylla L. (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    Ipou Ipou, J.

    2004-01-01

    Full Text Available Influence of some Environmental Factors on Euphorbia heterophylla L. (Euphorbiaceae Seeds Germination. In Ivory Coast, Euphorbia heterophylla appears as a weed in cotton fields. Effects of temperature, light and burying levels on its seed germination were tested. Temperature effects were monitored by means of 4 procedures, using a range of temperatures between 20 and 35 °C. The germination latency period can vary between 1 and 2 days, according to the temperature. After 4 days, germination rates were not longer related to temperature and were very similar. Germination can not happen without light. In order to measure the effect of burying levels, six series of 100 seeds were buried; the first at ground level, the others respectively 2, 4, 6, 8 and 9 cm deeper. Optimal germination rates were found for seeds that were buried between 0 and 6 cm.

  19. Radiation vulcanization of natural rubber latex with low energy accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Emdadul; Makuuchi, Keizo; Ikeda, Kenichi; Yoshii, Fumio; Kume Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Department of Biological and Chemical Engineering, Kiryu, Gunma (Japan)

    2001-03-01

    The radiation vulcanization of natural rubber latex (RVNRL) with the recently installed electron beam (EB) pilot plant at Takasaki Radiation Chemistry Research Establishment, Takasaki, Japan has been discussed. The accelerating voltage and beam current of the plant are 250 kV and 10 mA respectively. The plant has a reaction vessel with the capacity of 18 liters latex to irradiate at a time. In order to obtain a suitable setting of experimental for RVNRL under EB of the plant the parameters such as irradiation time, defoamer concentration, volume of latex, beam current etc. are being optimized by varying the individual parameter at a constant set of the other variables. (author)

  20. Reactivation of HIV-1 from Latency by an Ingenol Derivative from Euphorbia Kansui

    OpenAIRE

    Wang, Pengfei; Lu, Panpan; Qu, Xiying; Shen, Yinzhong; Zeng, Hanxian; Zhu, Xiaoli; Zhu, Yuqi; Li, Xian; Wu, Hao; Xu, Jianqing; Lu, Hongzhou; Ma, Zhongjun; Zhu, Huanzhang

    2017-01-01

    Cells harboring latent HIV-1 pose a major obstacle to eradication of the virus. The ?shock and kill? strategy has been broadly explored to purge the latent reservoir; however, none of the current latency-reversing agents (LRAs) can safely and effectively activate the latent virus in patients. In this study, we report an ingenol derivative called EK-16A, isolated from the traditional Chinese medicinal herb Euphorbia kansui, which displays great potential in reactivating latent HIV-1. A compari...

  1. Diminished UV-absorbing nets reduce the Spreads and population density of Macrosiphum euphorbiae in lettuce.

    OpenAIRE

    Legarrea, S.; Díaz, B. M.; Plaza, M.; Barrios, L.; Morales, Ignacio; Viñuela Sandoval, Elisa; Fereres Castiel, Alberto

    2012-01-01

    UV-absorbing covers reduce the incidence of injurious insect pests and viruses in protected crops. In the present study, the effect of a UV-absorbing net (Bionet) on the spatio-temporal dynamics of the potato aphid on lettuce plants was evaluated. A field experiment was conducted during three seasons in two identical tunnels divided in four plots. A set of lettuce plants were artificially infested with Macrosiphum euphorbiae adults and the population was estimated by counting aphids on ev...

  2. Isolation and characterization of latex-specific promoters from Papaver somniferum L.

    OpenAIRE

    Raymond, Michelle Jean

    2004-01-01

    The pharmacologically important alkaloids morphine and codeine are found in latex of opium poppy (Papaver somniferum). Latex is harbored in laticifers, a specialized vascular cell-type. Isolation and characterization of latex-specific genes may provide a useful tool to metabolically engineer increased alkaloid production. Previous research in the Nessler laboratory identified genes that exhibit latex-specific gene expression. Latex-specific genes were an 2-oxoglutarate-dioxygense (DIOX), ...

  3. Thermoresponsive latexes for fragrance encapsulation and release.

    Science.gov (United States)

    Popadyuk, N; Popadyuk, A; Kohut, A; Voronov, A

    2016-04-01

    To synthesize cross-linked latex particles protecting the encapsulated fragrance at ambient temperatures and facilitating the release of cargo at the temperature of the surface of the skin that varies in different regions of the body between 33.5 and 36.9°C. Poly(stearyl acrylate) (PSA), a polymer with long crystallizable alkyl side chains (undergoes order-disorder transitions at 45°C), was chosen as the main component of the polymer particles. As a result, new thermoresponsive polymer particles for fragrance encapsulation were synthesized and characterized, including assessing the performance of particles in triggered release by elevated temperature. To obtain network domains of various crystallinity, stearyl acrylate was copolymerized with dipropylene glycol acrylate caprylate (DGAC) (comonomer) in the presence of a dipropylene glycol diacrylate sebacate (cross-linker) using the miniemulsion process. Comonomers and a cross-linker were mixed directly in a fragrance during polymerization. Fragrance release was evaluated at 25, 31, 35 and 39°C to demonstrate a new material potential in personal/health care skin-related applications. Particles protect the fragrance from evaporation at 25°C. The fragrance release rate gradually increases at 31, 35 and 39°C. Two slopes were found on release plots. The first slope corresponds to a rapid fragrance release. The second slope indicates a subsequent reduction in the release rate. Crystalline-to-amorphous transition of PSA triggers the release of fragrances from cross-linked latex particles at elevated temperatures. The presence of the encapsulated fragrance, as well as the inclusion of amorphous fragments in the polymer network, reduces the particle crystallinity and enhances the release. Release profiles can be tuned by temperature and controlled by the amount of loaded fragrance and the ratio of comonomers in the feed mixture. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  4. Larval competition between Aphidius ervi and Praon volucre (Hymenoptera: Braconidae: Aphidiinae) in Macrosiphum euphorbiae (Hemiptera: Aphididae).

    Science.gov (United States)

    Sidney, Lívia Alvarenga; Bueno, Vanda Helena Paes; Lins, Juracy Caldeira; Sampaio, Marcus Vinicius; Silva, Diego Bastos

    2010-10-01

    Interspecific competition between parasitoid larvae may influence the size, structure, and stability of the population, leading to a reduction in total parasitism and thus restricting the pest control. Aphidius ervi (Haliday) and Praon volucre (Haliday) are endoparasitoids that possess a wide host range and present considerable potential for the biological control of the aphid Macrosiphum euphorbiae (Thomas). The larval competition between A. ervi and P. volucre, and the possible intrinsic competitive superiority of one of the parasitoids in M. euphorbiae, have been studied. In single parasitism experiments, mated parasitoid females (n=10) were maintained individually in contact with M. euphorbiae hosts (n=30) inside petri dishes containing lettuce leaf discs and maintained in environmental chamber at 22 ± 1°C, 70 ± 10% RH, and 12-h photophase. The multiple parasitism experiments consisted of exposing single parasitized aphids (n=120) to the second parasitoid species. Two oviposition events were performed with a 4-h interval between them, namely the following: sequence A (oviposition by A. ervi, followed by P. volucre) and sequence B (oviposition by P. volucre, followed by A. ervi). Oviposition sequence A generated 24 A. ervi and 55 P. volucre adults, whereas oviposition sequence B generated 23 and 49 adults. P. volucre is an intrinsically superior competitor compared with A. ervi, and the use of the two species simultaneously may result in competitive exclusion and influence the stability of the parasitoid population.

  5. Cryo-SEM studies of latex/ceramic nanoparticle coating microstructure development.

    Science.gov (United States)

    Luo, Hui; Scriven, L E; Francis, Lorraine F

    2007-12-15

    Cryogenic scanning electron microscopy (cryo-SEM) was used to investigate microstructure development of composite coatings prepared from dispersions of antimony-doped tin oxide (ATO) nanoparticles (approximately 30 nm) or indium tin oxide (ITO) nanoparticles (approximately 40 nm) and latex particles (polydisperse, D(v): approximately 300 nm). Cryo-SEM images of ATO/latex dispersions as-frozen show small clusters of ATO and individual latex particles homogeneously distribute in a frozen water matrix. In contrast, cryo-SEM images of ITO/latex dispersions as-frozen show ITO particles adsorb onto latex particle surfaces. Electrostatic repulsion between negatively charged ATO and negatively charged latex particles stabilizes the ATO/latex dispersion, whereas in ITO/latex dispersion, positively charged ITO particles are attracted onto surfaces of negatively charged latex particles. These results are consistent with calculations of interaction potentials from past research. Cryo-SEM images of frozen and fractured coatings reveal that both ceramic nanoparticles and latex become more concentrated as drying proceeds; larger latex particles consolidate with ceramic nanoparticles in the interstitial spaces. With more drying, compaction flattens the latex-latex particle contacts and shrinks the voids between them. Thus, ceramic nanoparticles are forced to pack closely in the interstitial spaces, forming an interconnected network. Finally, latex particles partially coalesce at their flattened contacts, thereby yielding a coherent coating. The research reveals how nanoparticles segregate and interconnect among latex particles during drying.

  6. Incidence of latex harvesting technologies on agronomic and ...

    African Journals Online (AJOL)

    parameters and profitability of some rapid metabolic class clones of rubber ... of hormonal stimulation had no negative influence on the vegetative growth ..... yield (2597) was obtained with the control ..... metabolic energy of latex vessels as.

  7. Incidence of latex harvesting technologies on agronomic and ...

    African Journals Online (AJOL)

    Incidence of latex harvesting technologies on agronomic and physiological parameters and profitability of some rapid metabolic class clones of rubber tree ( Hevea brasiliensis ) in southwestern Côte d'Ivoire.

  8. The Synthesis and Modification of Nanosized Clickable Latex Particles

    KAUST Repository

    Almahdali, Sarah

    2013-01-01

    This research aims to add to the current knowledge available for miniemulsion polymerization reactions and to use this knowledge to synthesize multifunctional nanosized latex particles that have the potential to be used in catalysis. The physical

  9. PS-HEMA latex fractionation by sedimentation and colloidal crystallization

    Directory of Open Access Journals (Sweden)

    Cardoso André H.

    1999-01-01

    Full Text Available A poly(styrene-co-hydroxyethylmethacrylate latex underwent sedimentation under gravity followed by an spontaneous and extensive colloidal crystallization. It was then fractionated in three visually distinguishable layers. Latex aliquots layers were sampled at different heigths and the particles were characterized by PCS, microelectrophoresis, infrared spectra and analytical electron microscopy. The major fraction was opalescent and contained the colloidal crystals settled in the bottom of the liquid. Two other latex fractions were obtained, which differed in their chemical compositions, particle sizes and topochemical features from the self-arraying particles. Macrocrystallization of the fractionated latex yielded high quality crystals with a low frequency of defects, which confirms that particle chemical homogeneity is an important factor for particle self-arraying.

  10. Radiation vulcanization of natural rubber latex sensitized with commercial gases

    Energy Technology Data Exchange (ETDEWEB)

    Chirinos, H.; Lugao, A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)

    2002-07-01

    The industrial activities using natural rubber latex are fully compatible with rural areas in Amazon and other places in Brazil, as well as in other tropical countries. However the classical sulfur vulcanization presents many occupational problems for the workers in rural areas. Radiation vulcanization of natural rubber latex is a much more friendly process as sulfur compounds are not needed for crosslinking, although chemicals as acrylate monomers, particularly multifunctional acrylates are still used as sensitizers for radiation processes. Two commercial gases, acetylene and butadiene, were selected as sensitizers for the radiation vulcanization of natural rubber latex instead of acrylates. These gases accelerate the crosslinking rates of the cure process and lower the radiation dose required to achieve vulcanization of natural rubber latex and improve the mechanical properties to reduce the tackiness of rubber goods. (author)

  11. Radiation vulcanization of natural rubber latex sensitized with commercial gases

    International Nuclear Information System (INIS)

    Chirinos, H.; Lugao, A.

    2002-01-01

    The industrial activities using natural rubber latex are fully compatible with rural areas in Amazon and other places in Brazil, as well as in other tropical countries. However the classical sulfur vulcanization presents many occupational problems for the workers in rural areas. Radiation vulcanization of natural rubber latex is a much more friendly process as sulfur compounds are not needed for crosslinking, although chemicals as acrylate monomers, particularly multifunctional acrylates are still used as sensitizers for radiation processes. Two commercial gases, acetylene and butadiene, were selected as sensitizers for the radiation vulcanization of natural rubber latex instead of acrylates. These gases accelerate the crosslinking rates of the cure process and lower the radiation dose required to achieve vulcanization of natural rubber latex and improve the mechanical properties to reduce the tackiness of rubber goods. (author)

  12. Assessment of adverse reactions to latex gloves use among nurses ...

    African Journals Online (AJOL)

    ... to latex is a common problem among nurses and other health care workers. ... There was significant association between family history and occurrence of ... These effects may vary in severity from skin problems to anaphylactic shock.

  13. Synthesis and characterization of novel polyacid-stabilized latexes.

    Science.gov (United States)

    Yang, Pengcheng; Armes, S P

    2012-09-18

    A series of novel polyacid macromonomers based on 2-hydroxypropyl methacrylate (HPMA) were prepared by atom transfer radical polymerization (ATRP) via a two-step route. First, a range of well-defined PHPMA homopolymer precursors were synthesized by ATRP using a tertiary amine-functionalized initiator, 2-(dimethylamino)ethyl-2-bromoisobutyrylamide, and a CuCl/2, 2'-bipyridine (bpy) catalyst in alcoholic media at 50 °C. ATRP polymerizations were relatively slow and poorly controlled in pure isopropanol (IPA), especially when targeting higher degrees of polymerization (DP > 30). Improved control was achieved by addition of water: low polydispersity (M(w)/M(n) propyl methacrylate) (PSPMA) macromonomers by quaternizing the tertiary amine end-group with excess 4-vinylbenzyl chloride, followed by esterification of the pendent hydroxyl groups using excess succinic anhydride at 20 °C. These polyacid macromonomers were evaluated as reactive steric stabilizers for polystyrene latex synthesis under either aqueous emulsion polymerization or alcoholic dispersion polymerization conditions. Near-monodisperse polystyrene latexes were obtained via aqueous emulsion polymerization using 10 wt % PSPMA macromonomer (with respect to styrene monomer) with various initiators as evidenced by scanning electron microscopy, disk centrifuge photosedimentometry and light scattering studies. PSPMA macromomer concentrations as low as 1.0 wt % also produced near-monodisperse latexes, suggesting that these PSPMA macromonomers are highly effective stabilizers. Alcoholic dispersion polymerization of styrene conducted in various ethanol/water mixtures with 10 wt % PSPMA(50) macromonomer produced relatively large near-monodisperse latexes. Increasing the water content in such formulations led to smaller latexes, as expected. Control experiments conducted with 10 wt % PSPMA(50) homopolymer produced relatively large polydisperse latexes via emulsion polymerization and only macroscopic precipitates via

  14. Radioactive iodine (125I) labeling of latex particles

    International Nuclear Information System (INIS)

    Parikh, G.C.; Ho, C.K.

    1977-01-01

    The invention disclosed in this application is directed towards developing a radioiodination method which is applicable to the labeling of 2.02 micrometer (μm) and 0.37 micrometer (μm) diameter polyvinyltoluene latex particles that have been used as an immunoadsorbent. More particularly the overall method includes using an oxidation-reduction chemical reaction for tagging latex particles. Two methods are described. One, the hydrochloric acid method; and two, the nitric acid method

  15. Immune response modulation by curcumin in a latex allergy model

    Directory of Open Access Journals (Sweden)

    Raju Raghavan

    2007-01-01

    Full Text Available Abstract Background There has been a worldwide increase in allergy and asthma over the last few decades, particularly in industrially developed nations. This resulted in a renewed interest to understand the pathogenesis of allergy in recent years. The progress made in the pathogenesis of allergic disease has led to the exploration of novel alternative therapies, which include herbal medicines as well. Curcumin, present in turmeric, a frequently used spice in Asia has been shown to have anti-allergic and inflammatory potential. Methods We used a murine model of latex allergy to investigate the role of curcumin as an immunomodulator. BALB/c mice were exposed to latex allergens and developed latex allergy with a Th2 type of immune response. These animals were treated with curcumin and the immunological and inflammatory responses were evaluated. Results Animals exposed to latex showed enhanced serum IgE, latex specific IgG1, IL-4, IL-5, IL-13, eosinophils and inflammation in the lungs. Intragastric treatment of latex-sensitized mice with curcumin demonstrated a diminished Th2 response with a concurrent reduction in lung inflammation. Eosinophilia in curcumin-treated mice was markedly reduced, co-stimulatory molecule expression (CD80, CD86, and OX40L on antigen-presenting cells was decreased, and expression of MMP-9, OAT, and TSLP genes was also attenuated. Conclusion These results suggest that curcumin has potential therapeutic value for controlling allergic responses resulting from exposure to allergens.

  16. Drying of latex films and coatings: Reconsidering the fundamental mechanisms

    DEFF Research Database (Denmark)

    Kiil, Søren

    2006-01-01

    The two existing theories describing drying of latex films or coatings are reconsidered. Subsequently, a novel mathematical drying model is presented, the simulations of which can match and explain experimental drying rate data of two previous investigations with latex films. In contrast to previ......The two existing theories describing drying of latex films or coatings are reconsidered. Subsequently, a novel mathematical drying model is presented, the simulations of which can match and explain experimental drying rate data of two previous investigations with latex films. In contrast...... to previous model studies, but in agreement with observations, simulations suggest that during the falling rate period of the drying process of a latex film, a porous skin of partly coalesced latex particles is indeed formed, which limits transport of water vapour from the receding air-liquid interphase...... to the surface of the film. The value of the effective diffusion coefficient of water vapour in the dry and partly coalesced layer (7 x 10(-7) m(2)/s at 19-24 degrees C), the adjustable parameter of the model for the falling rate period, was found to be independent of initial wet film thickness (89-1322 mu m...

  17. Troubleshooting for the observed problems in processing latex concentrate from natural resource

    International Nuclear Information System (INIS)

    Afreen, S; Haque, K R; Huda, M K

    2013-01-01

    Natural latex has special importance in the rubber industry for manufacturing different types of goods like gloves, balloons, male contraceptive and similar thin walled articles. This natural latex is much more sensitive a liquid to handle since it can easily become contaminated and thereby coagulated which makes it unfavourable for centrifuge and getting concentrate from it. Some other related measures also are included in consideration during the processing of concentrate latex from the natural raw latex. The problems that are being faced in a concentrate latex processing plant can be categorized in different groups like, problems related to the latex property, mechanical problems, electrical problems, handling and storage problems, transformation problems, problems related to environmental issues, etc. Among them, the most common and vital problems frequently observed in a concentrate latex processing plant are discussed here with a view to finding the measures for solution which will help to maintain the latex property in any latex processing plant.

  18. Experimental study of neuropharmacological profile of Euphorbia pulcherrima in mice and rats

    Directory of Open Access Journals (Sweden)

    Kundan Kr Singh

    2012-01-01

    Full Text Available Context: Euphorbia pulcherrima (EP belongs to the family: Euphorbiaceae and Genus: Euphorbia. Many species of Euphorbia have been reported as having beneficial properties like anticonvulsive effect, central analgesic properties, antipyretic action, central depressant action and strong sedative effect. However, little study has been done and published on EP. Aims: To observe and evaluate various neuropharmacological effects like antinociceptive effect, anticonvulsant effect, motor in-coordination, pentobarbital induced sleeping time and behavioral responses of EP in mice and rats. Setting and Design: Quantitative experimental study in mice and rats by various experimental models. Materials and Methods: Different experimental models were used to assess the antinociceptive effect (hotplate, tail flick and acetic acid induced writhing test, anticonvulsant effect (Maximal Electroshock Seizure test [MES] and Pentylenetetrazole induced seizures [PTZ], motor in-coordination effect (Rota rod test, pentobarbital induced sleeping time and behavioral responses of EP in mice and rats after oral administration of EP crude dried extracts in three different doses (250, 500 and 1000 mg/kg. Statistical Analysis Used: The significance of difference with respect to control was evaluated using the Mann-Whitney U test. A probability (P-value level less than 0.05 was considered as significant. Results: In MES test model, duration of tonic hind limb extension in mice treated with EP was significantly less as compared to vehicle treated group. EP was most effective in a dose of 1000 mg/kg. There was also significant increase in the latency and decrease in the incidence of convulsions with the use of EP in three different doses in PTZ induced seizure model. Conclusions: This study showed EP (crude dried extracts to possess anticonvulsant properties but no effect on motor co-ordination and anxiety.

  19. Antibacterial activity of the latex of Argemone ochroleuca Sweet

    International Nuclear Information System (INIS)

    Saad A. Alamri; Mahmoud F. Moustafa

    2010-01-01

    To investigate the antibacterial effect of the crude latex of Argemone ochroleuca (A. ochroleuca) as antibacterial potential against a range of human pathogenic bacteria. This study was carried out at King Khalid University, Abha, Kingdom of Saudi Arabia from January to March 2010. Seventeen ml of fresh latex from A. ochroleuca Sweet was collected, and the antibacterial activity of crude and diluted latex were examined using one ml of standardized inoculum suspension, and using the agar diffusion method test against Bacillus subtilis, Enterobacter aerogenes, Micrococcus luteus, Escherichia coli, and Staphylococcus aureus. All inoculated plates were incubated aerobically at 290C for 48 hours. The diameter of the zones of inhibition was measured to the nearest mm. The crude latex of A. ochroleuca exhibited a potent antibacterial effect on all bacterial strains examined. The zones of inhibition against the tested bacteria were found in the range of 9.30 - 40.3 mm along with their respective minimum inhibitory concentration values 100 ul/ml. The observable inhibition on selected bacteria by latex of A. ochroleuca makes it a promising alternative as a potential source of natural antibacterial (Author).

  20. Respiratory and dermal symptoms in Thai nurses using latex products.

    Science.gov (United States)

    Supapvanich, C; Povey, A C; de Vocht, F

    2013-09-01

    Despite known health risks related to the use of powdered latex gloves (PLGs), they are still widely used in hospitals in developing countries due to the high cost of alternatives. To determine the prevalence of dermal and respiratory symptoms associated with latex glove use in nurses in Thailand and evaluate the influence of previously reported occupational risk factors in this population. A cross-sectional study in female nurses working in three Thai hospitals. Participants completed a questionnaire on demographics, occupational and personal history, use of latex products at work and dermal and respiratory symptoms attributed to occupational use of latex gloves. Of 899 nurses, 18% reported health effects attributed to the use of latex products. After adjustment for confounding, occupational risk factors associated with increased reporting of dermal symptoms included wearing more than 15 pairs of PLG per day (odds ratio (OR): 2.10, 95% confidence interval (CI): [1.32-3.34]), using chlorhexidine (OR: 2.07, 95% CI: [1.22-3.52]) and being an operating theatre nurse (OR: 2.46, 95% CI: [1.47-4.12]). Being a labour ward nurse (OR: 3.52, 95% CI: [1.26-9.85]) was the only factor associated with increased reporting of respiratory symptoms. Continuing use of PLGs in Thai nurses is associated with increased prevalence of dermal symptoms compared with data from developed countries. Measures to reduce such health effects are well established and should be considered. Additionally, replacement of chlorhexidine with an alternative detergent seems advisable.

  1. Isolated or combined application of diuron, oxyfluorfen and prometryn for Euphorbia heterophylla control

    OpenAIRE

    Oliveira JR, R.S; Carneiro, J.C; Constantin, J; Santos, G; Martini, P.E; Francischini, A.C; Osipe, J.B

    2011-01-01

    A aplicação em pré-emergência no início do ciclo do algodoeiro é prática consagrada entre os produtores. Embora os herbicidas diuron, oxyfluorfen e prometryne sejam opções para uso nessa cultura, há informações limitadas referentes à eficácia desses herbicidas no controle de Euphorbia heterophylla. O objetivo do presente trabalho foi determinar a curva de dose-resposta de diuron, oxyfluorfen e prometryne para o controle de E. heterophylla, bem como analisar a eficiência biológica de misturas ...

  2. Latex-modified fiber-reinforced concrete bridge deck overlay : construction/interim report.

    Science.gov (United States)

    1993-06-01

    Latex-modified concrete (LMC) is Portland cement concrete (PCC) with an admixture of latex. LMC is considered to be nearly impermeable to chlorides and is extensively used to construct bridge deck overlays. Unfortunately, some of these overlays have ...

  3. Studies on physico-chemical and mechanical properties of the irradiated latex modified mortar

    International Nuclear Information System (INIS)

    Yassene, A.A.M.A.

    2009-01-01

    This thesis contains three chapter; chapter(I): Introduction and literature review on:- Introduction to polymer. - Mechanism of polymer-cement co-matrix formation.-Sulphate attack. - Solidification /stabilization of heavy metal in cement mortar. chapter(II): Materials and experimental techniques that include: 1- Preparation of latex polymer films from different polymer latices of styrene butadine rubber latex (SBR), poly (styrene-acrylic ester) latex (SAE) and vinylacetate /versatic -ester copolymer latex (C2A). The effect of γ-irradiation dose on the physico - chemical and mechanical properties of different latex polymer films was studied.2- Preparation of latex polymer-modified cement mortar with different ratios of cement: latex polymer and different curing method.3- Solidification /stabilization (S/S) of electroplating heavy metal precipitate in latex polymer- modified mortar with different cement /electroplating heavy metal sludge ratio. chapter(III) results and discussion

  4. Science and technology of rubber reclamation with special attention to NR based waste latex products

    NARCIS (Netherlands)

    Rajan, V.V.; Dierkes, Wilma K.; Joseph, R.; Noordermeer, Jacobus W.M.

    2006-01-01

    A comprehensive overview of reclamation of cured rubber with special emphasis on latex reclamation is depicted in this paper. The latex industry has expanded over the years to meet the world demands for gloves, condoms, latex thread, etc. Due to the strict specifications for the products and the

  5. Morphology and film formation of poly(butyl methacrylate)-polypyrrole core-shell latex particles

    NARCIS (Netherlands)

    Huijs, F; Lang, J

    Core-shell latex particles made of a poly(butyl methacrylate) (PBMA) core and a thin polypyrrole (PPy) shell were synthesized by two-stage polymerization. In the first stage, PBMA latex particles were synthesized in a semicontinuous process by free-radical polymerization. PBMA latex particles were

  6. IMMEDIATE AND DELAYED HYPERSENSITIVITY REACTIONS TO LATEX GLOVES IN A DENTAL STUDENT. A case report.

    Directory of Open Access Journals (Sweden)

    Iliyana Stoeva

    2011-08-01

    Full Text Available The article presents a case of dental student with immediate and delayed hypersensitivity reaction to latex gloves. Symptoms appeared during the second year of regularly using of latex gloves. The student was with no history of allergies and no previous exposure to latex products.

  7. The Effects of Temperature, Photoperiod, and Vernalization on Regrowth and Flowering Competence in Euphorbia Esula (Euphorbiaceae) Crown Buds

    Science.gov (United States)

    The herbaceous perennial weed Euphorbia esula (Euphorbiaceae) reproduces by vegetative and sexual means; characteristics that are key to its persistence and survival. In this study, we examined environmental effects on dormancy and flowering under controlled conditions to further validate field obse...

  8. POTENSI ANTIMIKROBIA KRIM EKSTRAK RANTING PATAH TULANG (Euphorbia tirucalli Linn. TERHADAP Propionibacterium acnes ATCC 11827 DAN Candida albicans ATCC 24433

    Directory of Open Access Journals (Sweden)

    Melina Scandinovita Setiorini

    2016-04-01

    extracts with cream for testing Candida albicans.The final results were 10% test extract had MIC to Propionibacterium acnes and 6% test extract had MIC in cream to Candida albicans. Keywords: Euphorbia tirucalli L., DMSO, Thymol, antimicrobial potency, cream (o/w, Propionibacterium acnes, Candida albicans

  9. Biological parameters and thermal requirements of the parasitoid Praon volucre (Hymenoptera: Braconidae) with Macrosiphum euphorbiae (Hemiptera: Aphididae) as host

    NARCIS (Netherlands)

    Conti, De B.F.; Bueno, V.H.P.; Sampaio, M.V.; Lenteren, van J.C.

    2011-01-01

    The effect of temperature on the biology of Praon volucre (Haliday, 1833) (Hymenoptera: Braconidae) in Macrosiphum euphorbiae (Thomas, 1878) (Hemiptera: Aphididae) hosts was studied and the thermal requirements of the parasitoid were determined. Experiments were carried out at 16, 19, 22, 25, and 28

  10. Use of biochar as peat substitute for growing substrates of Euphorbia × lomi potted plants

    International Nuclear Information System (INIS)

    Dispenza, V.; Pasquale, C. de; Fascella, G.; Mammano, M.M.; Alonzo, G.

    2016-01-01

    Biochar from conifers wood was used in soilless culture as growing substrate alternative to peat for ornamental crops. Potted plants of Euphorbia × lomi Rauh cv. ‘Ilaria’ were grown with different mixtures (v:v) of brown peat and biochar in order to evaluate main physical and chemical characteristics of this biomaterial as well as its effect on plant growth, ornamental characteristics and nutrients uptake. Biochar addition to peat increased pH, EC and K content of the growing substrates, as well as air content and bulk density. Biochar content of substrates significantly affected plant growth and biomass partitioning: higher number of shoots and leaves, leaf area and leaf dry weight were recorded in plants grown in 40% peat-60% biochar, with respect to plants grown in 100% peat and secondarily in 100% biochar. Leaf chlorophyll content was higher in plants grown in 60% and 80% biochar, while biomass water use efficiency was higher with 60% biochar. Plant uptake of K and Ca increased as biochar content of the substrates increased. Hence, a growing substrate containing 40% brown peat and 60% conifers wood biochar was identified as the more suitable mixture allowing to have a high-quality production of Euphorbia × lomi potted plants.

  11. Lipid metabolites with free-radical scavenging activity from Euphorbia helioscopia L.

    Science.gov (United States)

    Cateni, F; Zilic, J; Altieri, T; Zacchigna, M; Procida, G; Gaggeri, R; Rossi, D; Collina, S

    2014-07-01

    The methanolic extract of the plant Euphorbia helioscopia L. exhibited an interesting free-radical scavenging activity. From the aerial parts of Euphorbia helioscopia L. (Euphorbiaceae), a complex mixture of seven cerebrosides together with glucoclionasterol, a digalactosyldiacylglycerol and a diacylmonogalactosylglycerol were identified. The structures of the cerebrosides were characterized as 1-O-β-D-glucosides of phytosphingosines, which comprised (2S, 3S, 4E, 8E)-2-amino-4(E),8(E)-octadecadiene-1,3-diol, (2S, 3S, 4E, 8Z)-2-amino-4(E),8(Z)-octadecadiene-1,3-diol, (2S, 3S, 4R, 8Z)-2-amino-8(Z)-octadecene-1,3,4-triol as long chain bases with seven 2-hydroxy fatty acids of varying chain lengths (C16, C24:1, C26:1, C24, C26, C28:1) linked to the amino group. The glycosylglycerides were characterized as (2S)-2,3-O-di-(9,12,15-octadecatrienoyl)-glyceryl-6-O-(α-D-galactopyranosyl)-β-D-galactopyranoside and (2S)-2,3-O-di-(9,12,15-octadecatrienoyl)-glyceryl-1-O-β-D-galactopyranoside. The structures were established on the basis of spectroscopic data and chemical reactions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  12. Сhlorenchyma in stem of succulent plants from the genus Euphorbia L. (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    S.О. Kalashnyk

    2015-05-01

    Full Text Available The necessity of photosynthesis execution by stems causes the structural and functional changes in plants. The stems of majority of succulent plants of the genus Euphorbia L. are covered only with the epidermis for a long time. In plants of some species the palisade parenchyma can appear which can be considered as a secondary or consequential tool to perform photosynthesis function by their stems. The anatomical structure of green annual stems of 23 Euphorbia species was examined. For 12 of them the palisade parenchyma has been established. The palisade parenchyma in the stem differs from such in the leaf by cells form and size as well as cells arrangement. The presence or absence of palisade parenchyma in the primary cortex indicates the level of specialization of stem tissues to perform the assimilation function. As the degree of development of palisade parenchyma depends on the amount of solar radiation, the presence and number of palisade parenchyma does not directly confirm the adaptation to the growth in conditions of a certain degree of aridity. Its appearance is could be caused also by growth under high insolation. Undoubtedly, appearance of palisade parenchyma in the stems of stem-succulent plants is correlated with reduction of leaves and probably is consequence of this.

  13. Comparative ecomorphology of the cyathial nectaries in eight European Euphorbia species.

    Science.gov (United States)

    Papp, Nóra; Csete, S; Farkas, Agnes

    2013-03-01

    The morphology and histology of the cyathial nectary were studied in 8 European leafy spurge (Euphorbia) species, revealing that certain histological traits of the glands are in close correlation to each species' habitat, underlining the importance of morphological evidences in determining relevant ecological tolerance spectra of plants.The structure of the cyathial glands was studied in longitudinal sections with light microscopy, and histological parameters were measured and statistically analyzed by appropriate softwares.The nectaries consist of a cuticle-covered epidermis, formed by palisade cells, under which the glandular tissue and parenchyma are composed of isodiametric and anisodiametric cells in all species. Thickness of cuticle, position of nectary stomata and number of rows comprising the glandular tissue vary to a great extent in plants living in xeric, humid or mesic habitats.Although all the studied anatomical features of the nectaries were expected to be in correspondence with the characteristics of habitat types, we have only found the number of glandular cell rows to be in strong correlation with the Ellenberg's ecological indicator values on soil moisture, which varied with species. The recorded anatomical differences among the studied Euphorbia taxa emphasize the ecological significance of glandular tissue in plant adaptation, which can also be relevant for systematic purposes.

  14. Biomimetic Synthesis of Silver Nanoparticles Using Endosymbiotic Bacterium Inhabiting Euphorbia hirta L. and Their Bactericidal Potential

    Directory of Open Access Journals (Sweden)

    Baker Syed

    2016-01-01

    Full Text Available The present investigation aims to evaluate biomimetic synthesis of silver nanoparticles using endophytic bacterium EH 419 inhabiting Euphorbia hirta L. The synthesized nanoparticles were initially confirmed with change in color from the reaction mixture to brown indicating the synthesis of nanoparticles. Further confirmation was achieved with the characteristic absorption peak at 440 nm using UV-Visible spectroscopy. The synthesized silver nanoparticles were subjected to biophysical characterization using hyphenated techniques. The possible role of biomolecules in mediating the synthesis was depicted with FTIR analysis. Further crystalline nature of synthesized nanoparticles was confirmed using X-ray diffraction (XRD with prominent diffraction peaks at 2θ which can be indexed to the (111, (200, (220, and (311 reflections of face centered cubic structure (fcc of metallic silver. Transmission electron microscopy (TEM revealed morphological characteristics of synthesized silver nanoparticles to be polydisperse in nature with size ranging from 10 to 60 nm and different morphological characteristics such as spherical, oval, hexagonal, and cubic shapes. Further silver nanoparticles exhibited bactericidal activity against panel of significant pathogenic bacteria among which Pseudomonas aeruginosa was most sensitive compared to other pathogens. To the best of our knowledge, present study forms first report of bacterial endophyte inhabiting Euphorbia hirta L. in mediating synthesizing silver nanoparticles.

  15. Use of biochar as peat substitute for growing substrates of Euphorbia × lomi potted plants

    Directory of Open Access Journals (Sweden)

    Vincenzo Dispenza

    2016-12-01

    Full Text Available Biochar from conifers wood was used in soilless culture as growing substrate alternative to peat for ornamental crops. Potted plants of Euphorbia × lomi Rauh cv. ‘Ilaria’ were grown with different mixtures (v:v of brown peat and biochar in order to evaluate main physical and chemical characteristics of this biomaterial as well as its effect on plant growth, ornamental characteristics and nutrients uptake. Biochar addition to peat increased pH, EC and K content of the growing substrates, as well as air content and bulk density. Biochar content of substrates significantly affected plant growth and biomass partitioning: higher number of shoots and leaves, leaf area and leaf dry weight were recorded in plants grown in 40% peat-60% biochar, with respect to plants grown in 100% peat and secondarily in 100% biochar. Leaf chlorophyll content was higher in plants grown in 60% and 80% biochar, while biomass water use efficiency was higher with 60% biochar. Plant uptake of K and Ca increased as biochar content of the substrates increased. Hence, a growing substrate containing 40% brown peat and 60% conifers wood biochar was identified as the more suitable mixture allowing to have a high-quality production of Euphorbia × lomi potted plants.

  16. Use of biochar as peat substitute for growing substrates of Euphorbia × lomi potted plants

    Energy Technology Data Exchange (ETDEWEB)

    Dispenza, V.; Pasquale, C. de; Fascella, G.; Mammano, M.M.; Alonzo, G.

    2016-07-01

    Biochar from conifers wood was used in soilless culture as growing substrate alternative to peat for ornamental crops. Potted plants of Euphorbia × lomi Rauh cv. ‘Ilaria’ were grown with different mixtures (v:v) of brown peat and biochar in order to evaluate main physical and chemical characteristics of this biomaterial as well as its effect on plant growth, ornamental characteristics and nutrients uptake. Biochar addition to peat increased pH, EC and K content of the growing substrates, as well as air content and bulk density. Biochar content of substrates significantly affected plant growth and biomass partitioning: higher number of shoots and leaves, leaf area and leaf dry weight were recorded in plants grown in 40% peat-60% biochar, with respect to plants grown in 100% peat and secondarily in 100% biochar. Leaf chlorophyll content was higher in plants grown in 60% and 80% biochar, while biomass water use efficiency was higher with 60% biochar. Plant uptake of K and Ca increased as biochar content of the substrates increased. Hence, a growing substrate containing 40% brown peat and 60% conifers wood biochar was identified as the more suitable mixture allowing to have a high-quality production of Euphorbia × lomi potted plants.

  17. Identification of Phenolic Compounds and Evaluation of Antioxidant and Antimicrobial Properties of Euphorbia Tirucalli L.

    Directory of Open Access Journals (Sweden)

    Keline Medeiros de Araújo

    2014-03-01

    Full Text Available Bioactive compounds extracted from natural sources can benefit human health. The aim of this work was to determine total phenolic content and antioxidant activity in extracts of Euphorbia tirucalli L. followed by identification and quantification of the phenolic compounds, as well as their antibacterial activities. Antioxidant activities were determined by DPPH and ABTS•+ assay. Identification of phenolic compounds was performed using high-performance liquid chromatography (HPLC, and antimicrobial activities were verified by agar dilution methods and MIC values. Total phenolic content ranged from 7.73 to 30.54 mg/100 g gallic acid equivalent. Extracts from dry plants showed higher antioxidant activities than those from fresh ones. The DPPH EC50 values were approximately 12.15 μg/mL and 16.59 μg/mL, respectively. Antioxidant activity measured by the ABTS method yielded values higher than 718.99 μM trolox/g for dry plants, while by the Rancimat® system yielded protection factors exceeding 1 for all extracts, comparable to synthetic BHT. Ferulic acid was the principal phenolic compound identified and quantified through HPLC-UV in all extracts. The extracts proved effective inhibitory potential for Staphylococcus epidermidis and Staphylococcus aureus. These results showed that extracts of Euphorbia tirucalli L. have excellent antioxidant capacity and moderate antimicrobial activity. These can be attributed to the high concentration of ferulic acid.

  18. Euphorbia davidii - an invasive weed species in the fields of Serbia

    Directory of Open Access Journals (Sweden)

    Vajgand Dragan K.

    2014-01-01

    Full Text Available Euphorbia davidii Subils (Euphorbiaceae or toothed spurge is a plant native to North America, but in Europe it is an alien weed. The populations of this weed were recorded in the Province of Vojvodina (Serbia for the first time in 2007 in the arable fields in two localities: between the villages of Aleksa Šantić and Pačir and also between the villages of Pačir and Đurđin. There were no previous published data about the occurrence of this species in Serbia, nor about management measures in crops to suppress this agricultural invader. In this paper, we present experiences with several herbicide treatments applied to suppress populations of toothed spurge from the crop fields in Serbia during the last six years. The most effective was treatment with a high concentration of glyphosate in the early phases of toothed spurge growing. The populations of this invasive weed spread and formed more or less dense patches in the crop field, the area of distribution increased from 3 ha to 7 ha. Observations and experiences with treatments suggest that Euphorbia davidii, as an invasive plant, has significant impact on crop fields, therefore further investigation of suppression measures and monitoring of its population is needed.

  19. Polybutadiene latex particle size distribution analysis utilizing a disk centrifuge

    NARCIS (Netherlands)

    Verdurmen, E.M.F.J.; Albers, J.G.; German, A.L.

    1994-01-01

    Polybutadiene (I) latexes prepd. by emulsifier-free emulsion polymn. and having particle diam. 50-300 nm for both unimodal and bimodal particles size distributions were analyzed by the line-start (LIST) method in a Brookhaven disk centrifuge photosedimentometer. A special spin fluid was designed to

  20. Marine bacterial prodigiosin as dye for rubber latex, polymethyl ...

    African Journals Online (AJOL)

    Prodigiosin is known for its immunomodulatory, antibacterial, antimycotic, antimalarial, algicidal and anticancer activities. Here, we reported the evaluation of prodigiosin pigment as a dyeing agent in rubber latex, paper and polymethyl methacrylate (PMMA) so that it can be considered as an alternative to synthetic pigments.

  1. Pilot scale experiments on radiation vulcanization of NR latex

    Science.gov (United States)

    Ridwan, M.

    The potential of irradiated latex as raw material of commercial use is under testing on pilot plant scale in Indonesia which has 225 kCi Co-60 irradiation facility and can irradiate 1000 tonnes of centrifuged latex per annum. The facility was jointly designed by BATAN of Indonesia and JAERI of Japan and was jointly financed by UNDP/IAEA, Government of Japan and Government of Indonesia under UNDP/IAEA Regional Cooperative Agreement Project on Industrial Application of Isotopes and Radiation Technology. The facility is a water pool type and can accomodate 400 kCi Co-60. The Co-60 rack has two shapes, plate and cylindrical shapes. The plate shape source is used for natural rubber latex irradiation and the cylindrical one is used for other irradiation services. The vulcanization system consists of three major components : emulsification unit ( height : 650 mm, diameter 500 mm ), mixing unit ( height : 1900mm, diameter 1200 mm ) and vulcanization reactor ( height : 1800 mm, diameter 1300 mm ). The first two components are located outside shielded room while the third one-in irradiation room. The radiation vulcanization process is a much simpler energy saving process comparedto the conventional thermal process which has two vulcanization steps before and after dipping. The physical and mechanical properties of irradiated NR Latex are comparable to those of sulfur vulcanized, and depend on many factors such as irradiation dose, sensitizer content, dry rubber content and storage time.

  2. Oil-Acrylic hybrid latexes as binders for waterborne coatings

    NARCIS (Netherlands)

    Hamersveld, E.M.S.; Es, van J.J.G.S.; German, A.L.; Cuperus, F.P.; Weissenborn, P.; Hellgren, A.C.

    1999-01-01

    The combination of the characteristics of oil, or alkyd, emulsions and acrylic latexes in a waterborne binder has been the object of various studies in the past. Strategies for combining the positive properties of alkyds, e.g. autoxidative curing, gloss and penetration in wood, with the fast drying

  3. Oil-acrylic hybrid latexes as binders for waterborne coatings

    NARCIS (Netherlands)

    Hamersveld, van E.M.S.; Es, van J.; German, A.L.; Cuperus, F.P.; Weissenborn, P.; Hellgren, A.C.

    1999-01-01

    The combination of the characteristics of oil, or alkyd, emulsions and acrylic latexes in a waterborne binder has been the object of various studies in the past. Strategies for combining the positive properties of alkyds, e.g. autoxidative curing, gloss and penetration in wood, with the fast drying

  4. The construction and commissioning of MINT's latex irradiator

    International Nuclear Information System (INIS)

    Razali Hamzah; Muhd Khairi Muhd Said; Muhd Ariff Hamzah; Wan Manshol Wan Zin; Taiman Kadni

    1996-01-01

    The construction and installation of MINT's automatic continuous latex irradiator is described. MINT cooperated with NUKEM to design the plant. Construction was done by local building consultants and local contractor. The installation of the plant includes local fabrication components and imported components. The plant is automatically controlled by a computer system. Features of plant is described

  5. Pilot scale experiments on radiation vulcanization of NR latex

    International Nuclear Information System (INIS)

    Ridwan, M.

    1985-01-01

    The potential of irradiated latex as raw material of commercial use is under testing on pilot plant scale in Indonesia which has 225 kCi Co-60 irradiation facility and can irradiate 1000 tonnes of centrifuged latex per annum. The facility was jointly designed by BATAN of Indonesia and JAERI of Japan and was jointly financed by UNDP/IAEA, Government of Japan and Government of Indonesia under UNDP/IAEA Regional Cooperative Agreement Project on Industrial Application of Isotopes and Radiation Technology. The facility is a water pool type and can accommodate 400 kCi Co-60. The Co-60 rack has two shapes, plate and cylindrical shapes. The plate shape source is used for natural rubber latex irradiation and the cylindrical one is used for other irradiation services. The vulcanization system consists of three major components: emulsification unit, mixing unit and vulcanization reactor. The first two components are located outside shielded room while the third one in irradiation room. The radiation vulcanization process is a much simpler energy saving process compared to the conventional thermal process which has two vulcanization steps before and after dipping. The physical and mechanical properties of irradiated NR latex are comparable to those of sulfur vulcanized. (author)

  6. Study of glucoamylase immobilization in butadiene nitrile latex membrane

    International Nuclear Information System (INIS)

    Miller, E.

    1992-01-01

    Attempts have been undetaken to immobilize glucoamylaze by means of butadiene nitrile latex in the presence of a chemical initiator and 60 Co γ-radiation. The activity, stability of conjugates in the membrane and permeability of oxygen in these membranes were determined. (author) 14 refs.; 5 figs

  7. LaTeX - Know what you are missing

    Directory of Open Access Journals (Sweden)

    Gunther Maier

    2016-11-01

    Full Text Available This article gives a brief introduction to \\LaTeX\\ and related tools. The aim is to give an overview, to demonstrate the flexibility and versatility of the software, and to assist the reader taking first steps using it. The article links to a number of valuable resources for further information.

  8. Latex allergy in an infant with acquired hydrocephalus | Ehiozw ...

    African Journals Online (AJOL)

    We report the case of a 3 month old male infant with acquired hydrocephalus undergoing ventriculo-peritoneal shunt insertion who developed wheals and suffered a respiratory arrest following contact with latex gloves. The need for anaesthetists to effectively diagnose and properly manage this rare clinical entity is ...

  9. Natural rubber latex: determination and interpretation of flow curves

    Directory of Open Access Journals (Sweden)

    Harrison Lourenço Corrêa

    2015-08-01

    Full Text Available AbstractAs consumers become more demanding, the importance grows of guaranteeing the quality of products. The employment of reliable testing techniques that assure the origin and characteristics of the inputs used by industry is a key factor in this respect. In the rubber processing industry, the most commonly used characterization tests include determination of the total solids and dry rubber content, mechanical stability, odor, color and presence of volatile compounds, among others. For the most part, these tests are sufficient for the latex transformation industry. However, in situations where there is a need to know the behavior of latex in reaction to the mechanical forces of machines (mixers, pumps, etc., other tests must be used. Rheological tests to determine viscoelastic data by means of plotting flow curves combined with the application of theoretical models can provide important details for characterization of different types of latex. This article presents the protocol employed by the Rheology and Image Laboratory of Rio de Janeiro State University (UERJ for the rheological study of Brazilian latex. The samples analyzed came from the state of São Paulo.

  10. Partial swelling of latex particles by two monomers

    NARCIS (Netherlands)

    Noel, E.F.J.; Maxwell, I.A.; German, A.L.

    1993-01-01

    The swelling of polymeric latex particles with solvent and monomer is of great importance for the emulsion polymn. process in regard to compn. drift and rate of polymn. For the monomer combination, Me acrylate-vinyl acetate, both satn. and partial swelling were detd. exptl. Theories for satn.

  11. Interferência de Euphorbia heterophylla no crescimento e acúmulo de macronutrientes da soja Interference of Euphorbia heterophylla in the growth and macronutrient accumulation of soybean

    Directory of Open Access Journals (Sweden)

    L.B. Carvalho

    2010-01-01

    Full Text Available O grau de interferência depende da densidade de plantas daninhas que infestam a soja. O objetivo deste trabalho foi avaliar características de crescimento e nutrição mineral da soja mantida em convivência com densidades crescentes de Euphorbia heterophylla. O experimento foi conduzido em Jaboticabal, SP, Brasil, entre outubro e dezembro de 2008, em vasos mantidos em campo aberto. Os tratamentos consistiram em submeter uma planta de soja por vaso à convivência com 0, 1, 2, 4, 8 e 16 plantas de E. heterophylla por vaso, da semeadura até o início do florescimento. Nesse período, avaliaram-se, apenas na soja, a altura e o número de trifólios, e em ambas as espécies, a matéria seca e o acúmulo de macronutrientes. Observou-se variação na altura de plantas e redução no número de trifólios e no acúmulo de matéria seca e macronutrientes da soja devido ao maior acúmulo de matéria seca e macronutrientes por densidades crescentes de E. heterophylla. Conclui-se que a soja mantida em convivência com E. heterophylla teve o crescimento e o acúmulo de macronutrientes reduzidos em razão da interferência imposta pela planta daninha.The degree of weed interference depends on the density of the weeds infesting the soybean crop. The objective of this work was to evaluate the growth and mineral nutrition characteristics in soybean maintained in coexistence with increasing densities of Euphorbia heterophylla. The experiment was carried out in Jaboticabal, SP, Brazil, from October through December 2008, in pots maintained under open field conditions. The treatments consisted in submitting one soybean plant per pot to coexistence with 0, 1, 2, 4, 8 and 16 plants of E. heterophylla per pot, from sowing until the beginning of soybean flowering. At this period, only height and number of leaves were evaluated in soybean, while dry matter and macronutrient accumulation were evaluated in both species. Variation in plant height and reduction in the

  12. Ten years incidence of natural rubber latex sensitization and symptoms in a prospective cohort of health care workers using non-powdered latex gloves 2000-2009.

    Science.gov (United States)

    Larese Filon, Francesca; Bochdanovits, Letizia; Capuzzo, Chiara; Cerchi, Roberto; Rui, Francesca

    2014-07-01

    To assess the incidence of sensitization and gloves-related symptoms in 10-year follow-up in a group of health care workers (9,660 person-years) using non-powdered latex gloves from 2000 to 2009 and to examine related factors. We studied 2,053 health care workers in Trieste Hospitals by means of skin prick test for latex extract, patch tests and medical examinations. We report the incidence of latex sensitization among workers using non-powdered latex gloves. The incidence of latex sensitization, rhinitis, asthma, urticaria, irritant and allergic contact dermatitis were 1.0; 0.12; 0.21; 0.72; 2.39 and 2.50 cases per 1,000 person-years, respectively. Respiratory symptoms and urticaria were positively related with latex sensitization (OR = 8.0; 95 % CL 1.27-48.6), with common allergic respiratory symptoms (OR = 4.19; 95 % CL 1.04-16.8) and with familial atopy (OR = 4.47; 95 % CL 1.1-17.9). The incidence of latex sensitization and latex-related symptoms were very low but subjects with allergic symptoms related to common allergens are at higher risk. The use of non-latex gloves is suggested for them.

  13. Alergia látex-fruta Latex-fruit allergy

    Directory of Open Access Journals (Sweden)

    Flávia Andréia MARIN

    2002-01-01

    Full Text Available O látex está sendo considerado o alergênico do ano 2000, tendo em vista que inúmeros indivíduos, principalmente profissionais da área de saúde e pacientes submetidos a várias intervenções diagnósticas e terapêuticas, estão freqüentemente expostos aos alérgenos do látex, presentes em produtos de borracha natural. As manifestações clínicas conseqüentes às reações alérgicas de hipersensibilidade imediata vão desde rinite, urticária, conjuntivite, angioedema, asma, até anafilaxia. Estudos recentes estão demonstrando que pacientes alérgicos ao látex desenvolvem concomitantemente sensibilização a certos alimentos de origem vegetal, especialmente frutas como papaia, figo, banana, abacate, kiwi, pêssego, abacaxi, melão e castanha, acreditando-se numa provável ocorrência de reações cruzadas entre os alérgenos do látex e destas frutas. Faz-se, então, uma revisão sobre a alergia ao látex, em particular sobre os grupos de risco, incluindo a presença de reatividade cruzada entre o látex e as frutas.The latex is being considered the allergenic agent of the year 2000, taking into account that several individuals, mainly health care professionals, and patients who had undergone many diagnostic and therapeutic interventions, are frequently exposed to latex allergens, which are present in natural rubber latex products. The clinical manifestations, derived from allergic reactions of immediate hypersensitivity vary from since rhinitis, conjunctivitis, urticaria, angioedema, asthma, to anaphylaxis. Recent researches are demonstrating that patients allergic to latex develop concomitantly sensitization to certain vegetable foods, especially fruits like papaya, fig, banana, avocado, kiwi, peach, pineapple, melon and chestnut, and a probable occurrence of cross reaction between allergens of latex and of these fruits is believed. A review is made about latex allergy, in particular about risk groups, including the presence of

  14. Application of radiation vulcanized natural rubber latex in Indonesia

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Wiwik Sofiarti; Razzak, M.T.

    1996-01-01

    The center has carried out R and D of Radiation Vulcanization Natural Rubber Latex (RVNRL) technology and introduced it to the industries since the inauguration and operation of the latex pilot plant in 1983. After years of experiences and the environmental consideration, n-butylacrylate (n-BA) has replaced CCI, as the sensitizer. Until now the introduction program shows that radiation vulcanized latex is more suitable for home industries than large industries. The obstacle of the program is the marketing of the dipped products. In spite of these problems, the introduction of this technology to the people in some undeveloped area of Java has supported the national program to improve their living standard. The problems of nitrosamine and protein allergic have turn up RVNRL to be the substitute of sulfur vulcanized latex in the future. The cooperation with a national condom manufacturer (PT Mitra Banjaran) has applied RVNRL for condom production in the large scale. Soft condoms with less probability of pinhole are obtained, but the technical problem is stickiness after pilling. Supply to a baby teat and a rubber thread manufacturer offers great advantages by not using any chemicals. In spite of the advantages, the problem of latex viscosity for dipping and the low modulus of elasticity of the threads arise. Through those input CAIR-BATAN is conducting the research and development in improving the crosslinking among the rubber particles that are supposed to be the reason of the stickiness and low modulus of elasticity. This effort is expected to be able to broaden the application of RVNRL, and it will be achieved only by the involvement of rubber chemist, rubber technologist, and radiation chemist

  15. A novel arctigenin-containing latex glove prevents latex allergy by inhibiting type I/IV allergic reactions.

    Science.gov (United States)

    Wang, Yong-Xin; Xue, Dan-Ting; Liu, Meng; Zhou, Zheng-Min; Shang, Jing

    2016-03-01

    The present study aimed at developing a natural compound with anti-allergic effect and stability under latex glove manufacturing conditions and investigating whether its anti-allergic effect is maintained after its addition into the latex. The effects of nine natural compounds on growth of the RBL-2H3 cells and mouse primary spleen lymphocytes were determined using MTT assay. The compounds included glycyrrhizin, osthole, tetrandrine, tea polyphenol, catechin, arctigenin, oleanolic acid, baicalin and oxymatrine. An ELISA assay was used for the in vitro anti-type I/IV allergy screening; in this process β-hexosaminidase, histamine, and IL-4 released from RBL-2H3 cell lines and IFN-γ and IL-2 released from mouse primary spleen lymphocytes were taken as screening indices. The physical stability of eight natural compounds and the dissolubility of arctigenin, selected based on the in vitro pharnacodynamaic screening and the stability evaluation, were detected by HPLC. The in vivo pharmacodynamic confirmation of arctigenin and final latex product was evaluated with a passive cutaneous anaphylaxis (PCA) model and an allergen-specific skin response model. Nine natural compounds showed minor growth inhibition on RBL-2H3 cells and mouse primary spleen lymphocytes. Baicalin and arctigenin had the best anti-type I and IV allergic effects among the natural compounds based on the in vitro pharmacodynamic screening. Arctigenin and catechin had the best physical stability under different manufacturing conditions. Arctigenin was the selected for further evaluation and proven to have anti-type I and IV allergic effects in vivo in a dose-dependent manner. The final product of the arctigenin-containing latex glove had anti-type I and IV allergic effects in vivo which were mainly attributed to arctigenin as proved from the dissolubility results. Arctigenin showed anti-type I and IV allergic effects in vitro and in vivo, with a good stability under latex glove manufacturing conditions

  16. Estudos anatômicos de folhas de espécies de plantas daninhas de grande ocorrência no Brasil: IV - Amaranthus deflexus, Amaranthus spinosus, Alternanthera tenella e Euphorbia heterophylla Leaf anatomical studies in weed species widely common in Brazil: IV - Amaranthus deflexus, Amaranthus spinosus, Alternanthera tenella and Euphorbia heterophylla

    Directory of Open Access Journals (Sweden)

    E.A. Ferreira

    2003-08-01

    Full Text Available Neste trabalho é apresentado um estudo da anatomia das folhas de espécies de plantas daninhas de grande ocorrência no Brasil: Amaranthus deflexus, Amaranthus spinosus, Alternanthera tenella e Euphorbia heterophylla, visando melhor compreensão das barreiras que cada espécie impõe à penetração dos herbicidas e outros compostos utilizados em aplicações foliares. As folhas completamente expandidas do terceiro ao quinto nó foram coletadas de plantas de ocorrência espontânea no campo. Das folhas de cada espécie foram obtidas três amostras da região mediana, com aproximadamente 1 cm², as quais foram utilizadas em estudos da estrutura, clarificação e em observações em microscópio eletrônico de varredura. Todas as espécies avaliadas são anfiestomáticas. As principais barreiras foliares potenciais à penetração de herbicidas observadas nas plantas daninhas A. deflexus e A. spinosus foram, respectivamente, grande espessura da cutícula da face adaxial e da cutícula das duas faces. Já em relação a A. tenella, grande espessura da cutícula das duas faces, elevado teor de cera epicuticular e alta densidade tricomática foram os principais obstáculos potenciais detectados. E. heterophylla apresentou como possíveis principais barreiras foliares à penetração de agroquímicos o alto teor de cera epicuticular, a elevada densidade de laticíferos e a grande espessura da cutícula da face adaxial.This research aimed to study the leaf anatomy of the weed species Amaranthus deflexus, Amaranthus spinosus, Alternanthera tenella and Euphorbia heterophylla, widely known in Brazil, to acquire a better understanding of the barriers each species imposes to herbicide penetration, and to other substances used for leaf spraying. Completely expanded leaves from the third to the fifth nodes were collected from spontaneous plants in the field. Three samples approximately 1cm², were removed from the medium portion of the leaves, from each

  17. Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

    Directory of Open Access Journals (Sweden)

    K. Al-Mughrabi

    2003-12-01

    Full Text Available Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. stolonifer. The weakest effect was against A. solani. Extracts from the stems had a stronger inhibitory effect than those from the flowers or leaves. Butanol was the best solvent to extract antimicrobial compounds from leaves, stems and flowers and was superior to chloroform, water and petroleum ether. Results clearly indicate that E. macroclada is a promising source of antimicrobial compounds.

  18. Caper spurge (Euphorbia lathyris L. ) as a potential crop plant of oleochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Hondelmann, W.; Dambroth, M.

    1987-01-01

    Caper Spurge (Euphorbia lathyris L.) on account of the high seed oil content and the dominating position of oleic acid (> 80%) calls for special attention as potential creep plant for oleochemistry. In domesticating this wild species the characters 'biennial life cycle' and 'dehiscent fruits' could be eliminated in favour of their corresponding crop plant characters 'annual life cycle' and 'indehiscent fruits'. The genetic variation hitherto available seems to be relatively limited. Very high is the amount of 'variation between populations'. Estimates of heritability generally are high, but response to selection is predominantly lower. Because of the rather low fracture resistance of the seed coat the adaption for harvesting by means of a combine is not yet existing. Furthermore, caper spurge exhibits a strongly expressed seed dormancy. Therefore, selection in favour of a diminished primary dormancy is needed. (orig.)

  19. Hydropyrolysis of extracted Euphorbia rigida in a well-swept fixed-bed tubular reactor

    Energy Technology Data Exchange (ETDEWEB)

    Gercel, H.F.; Putun, A.E.; Putun, E.

    2002-05-01

    Tubular reactor fixed-bed hydropyrolysis experiments have been conducted on a sample of extracted Euphorbia rigida to determine the possibility of being a potential source of renewable fuels and chemical feedstock. The effects of hydropyrolysis temperature and heating rate on the hydropyrolysis yields and chemical compositions have been investigated. The maximum bio-oil yield of 39.8 wt% was obtained in H{sub 2} atmosphere at a hydrogen pressure of 150 bar, a hydrogen flow rate of 5 dm{sup 3} min{sup -} {sup 1}, a hydropyrolysis temperature of 550{sup o}C, and a heating rate of 100{sup o}C min{sup -1}. Then this bio-oil was characterized by elemental analysis and {sup 1}H nuclear magnetic resonance (NMR) techniques. (author)

  20. Overexpression of the AtSHI gene in poinsettia, Euphorbia pulcherrima, results in compact plants

    DEFF Research Database (Denmark)

    Islam, M. Ashraful; Lütken, Henrik Vlk; Haugslien, Sissel

    2013-01-01

    of the AtSHI gene into poinsettia by genetic engineering can be an effective approach in controlling plant height without negatively affecting flowering time. This can help to reduce or avoid the use of toxic growth retardants of environmental and human health concern. This is the first report that At......Euphorbia pulcherrima, poinsettia, is a non-food and non-feed vegetatively propagated ornamental plant. Appropriate plant height is one of the most important traits in poinsettia production and is commonly achieved by application of chemical growth retardants. To produce compact poinsettia plants...... integration of transgene was verified by PCR and Southern blot analysis. Reduced plant height (21–52%) and internode lengths (31–49%) were obtained in the transgenic lines compared to control plants. This correlates positively with the AtSHI transcript levels, with the highest levels in the most dwarfed...

  1. Host Plant Volatiles and the Sexual Reproduction of the Potato Aphid, Macrosiphum euphorbiae

    Directory of Open Access Journals (Sweden)

    Jessica Hurley

    2014-10-01

    Full Text Available In late summer, heteroecious aphids, such as the potato aphid, Macrosiphum euphorbiae, move from their secondary summer host plants to primary host plants, where the sexual oviparae mate and lay diapausing eggs. We tested the hypothesis that volatiles of the primary host, Rosa rugosa, would attract the gynoparae, the parthenogenetic alate morph that produce oviparae, as well as the alate males foraging for suitable mates. In wind tunnel assays, both gynoparae and males oriented towards and reached rose cuttings significantly more often than other odour sources, including potato, a major secondary host. The response of males was as high to rose cuttings alone as to potato with a calling virgin oviparous female. These findings are discussed within the seasonal ecology of host alternating aphids.

  2. Allelopathy of small everlasting (Antennaria microphylla) : Phytotoxicity to leafy spurge (Euphorbia esula) in tissue culture.

    Science.gov (United States)

    Hogan, M E; Manners, G D

    1990-03-01

    Media and media extracts from callus cultures of small everlasting (Antennaria microphylla) inhibited leafy spurge (Euphorbia esula L.) callus tissue and suspension culture growth (50 and 70% of control, respectively) and were phytotoxic in lettuce and leafy spurge root elongation bioassays (64 and 77% of control, respectively). Hydroquinone, a phytotoxic compound previously isolated from small everlasting, was also biosynthesized by callus and suspension cultures of this species. Exogenously supplied hydroquinone (0.5 mM) was toxic to leafy spurge suspension culture cells and was only partially biotransformed to its nontoxic water-soluble monoglucoside, arbutin, by these cells. This report confirms the chronic involvement of hydroquinone in the allelopathic interaction between small everlasting and leafy spurge.

  3. Total phenolic compounds, antioxidant potential and α-glucosidase inhibition by Tunisian Euphorbia paralias L.

    Directory of Open Access Journals (Sweden)

    Malek Besbes Hlila

    2016-08-01

    Full Text Available Objective: To examine the potential antioxidant and anti-α-glucosidase inhibitory activities of Tunisian Euphorbia paralias L. leaves and stems extracts and their composition of total polyphenol and flavonoids. Methods: The different samples were tested for their antiradical activities by using 2, 2’- azinobis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS and 1,1-diphenyl-2-picrylhydrazyl (DPPH assays. In α-glucosidase activity, α-glucosidase (0.3 IU/mL and substrate, 2500 µmol/ L p-nitrophenyl α-D-glucopyranoside were used; absorbance was registered at 405 nm. Results: The leaves acetonic extract exhibited the strongest α-glucosidase inhibition [IC50 = (0.0035 ± 0.001 µg/mL], which was 20-fold more active than the standard product (acarbose [IC50 = (0.07 ± 0.01 µg/mL]. Acetonic extract of the leaves exhibited the highest quantity of total phenolic [(95.54 ± 0.04 µg gallic acid equivalent/mg] and flavonoid [(55.16 ± 0.25 µg quercetin equivalent/mg]. The obtained findings presented also that this extract was detected with best antioxidant capacity [IC50 = (0.015 ± 0.01 µg/mL] against DPPH and a value of IC50 equal to (0.02 ± 0.01 µg/mL against ABTS. Positive relationship between polyphenolic content of the tested Euphorbia paralias L. leaves and stems extracts and its antioxidant activity (DPPH and ABTS was detected. Elevated positive linear correlation was got between ABTS and total phenolic (R2 = 0.751. Conclusions: The findings clearly demonstrate that the use of a polar solvent enables extraction of significant quantities of phenol compounds and flavonoids.

  4. Crescimento e esporulação de Bipolaris euphorbiae cultivado sob diferentes condições nutricionais Growth and sporulation of Bipolaris euphorbiae cultivated under different nutritional conditions

    Directory of Open Access Journals (Sweden)

    Mara Cristina Penariol

    2008-10-01

    Full Text Available Apesar de ser considerado um potencial bioagente de controle do amendoim-bravo (Euphorbia heterophylla L. em cultivos de soja no Brasil, pouco se conhece sobre as características nutricionais do fungo Bipolaris euphorbiae Muchovej & Carvalho. O objetivo deste trabalho foi avaliar diferentes fontes de carbono (glicose, amido, sacarose, lactose e maltose, de nitrogênio (nitrato de sódio, nitrato de amônio, sulfato de amônio, fosfato de amônio dibásico, cloreto de amônio, de fósforo (fosfato de potássio monobásico, fosfato de potássio bibásico, fosfato de cálcio, fosfato de sódio, ácido fosfórico, fosfato de amônio e a suplementação do meio de cultivo com fontes orgânicas de macro e micronutrientes, para o crescimento e a esporulação de B. euphorbiae. O amido proporcionou o maior crescimento, sendo também considerada a fonte de carbono mais favorável para a esporulação. O melhor crescimento e esporulação de B. euphorbiae foram obtidos usando o nitrato de sódio como fonte de nitrogênio e fosfato de potássio monobásico e fosfato de cálcio como fonte de fósforo, embora as demais fontes de fósforo analisadas, exceto o ácido fosfórico, tenham igualmente favorecido a esporulação. A suplementação do meio de cultivo com peptona e extrato de levedura resultou em melhor crescimento e esporulação do fungo e a adição de vitaminas favoreceu a produção de conídios.Bipolaris euphorbiae Muchovej & Carvalho is considered a potential bioagent for control of selvage peanuts (Euphorbia heterophylla L. on soybean crops in Brazil. However, little is known about the nutritional characteristics of this fungus. The main objective of this research was to evaluate different sources of carbon (glucose, starch, sucrose, lactose and maltose, of nitrogen (sodium nitrate, ammonium nitrate, ammonium sulphate, bi-basic ammonium phosphate, ammonium chloride, of phosphorus (monobasic potassium phosphate, bi-basic potassium phosphate

  5. Effect of applied environmental stress on growth, photosynthesis, carbon allocation, and hydrocarbon production in Euphorbia lathyris

    International Nuclear Information System (INIS)

    Taylor, S.E.; Calvin, M.

    1988-01-01

    Photosynthetic activity was reduced by salinity stress, but is was found to be less sensitive than growth. Salinity stress also caused changes in the concentrations of specific cations. Moderate water stress had little effect on growth, but large changes in hydrocarbon production were still observed. Carbon allocation experiments with radiolabeled carbon indicated that carbon for latex production was supplied by nearby leaves, with some translocation down the stem also occurring

  6. Osmotic de-swelling and swelling of latex dispersions

    International Nuclear Information System (INIS)

    Bonnet-Gonnet, Cecile

    1993-01-01

    This research thesis reports the comparison of, on the one hand, direct measurements of de-swelling resistance of latex dispersions obtained by osmotic pressure with, on the other hand, predictions made by models of electrostatic interactions. This resistance is explained in the case of sulphate-stabilised polystyrene particles (direct repulsion between charged particles), and in the case of copolymer (ps-pba) particles covered by an amphiphilic polymer (interactions between surface macromolecules and polymers). The study of de-swelling and swelling cycles highlights the existence of thresholds beyond which the concentrated dispersion has some cohesion. This irreversibility can be modelled by a Van der Waals attraction. The role of hydrophobic forces in latex destabilisation is studied [fr

  7. Extractable protein of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Upul, R.M.; Makuuchi, K.; Yoshii, F.; Kume, T.

    2000-01-01

    A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) as much as 3 phr in three different processes: added to RVNRL, added to re-centrifuged RVNRL, and added to RVNRL followed by centrifugation. The protein content was determined by enhanced BCA method, and identified by SDS-PAGE analysis. Addition of WSP followed by centrifugation reduces EP up to the minimum protein detection, and shortens the leaching time to 20-30 min. SDS-PAGE analysis confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The molecular weight of WSP dictates the efficiency of protein removal. (author)

  8. [Anaphylactic reaction to latex during spinal anesthesia: a case report].

    Science.gov (United States)

    Ueda, Narumi; Kitamura, Rie; Wakamori, Takeshi; Nakamura, Kumi; Konishi, Keisuke

    2008-05-01

    A 46-year-old man, with a history of atopic dermatitis and bronchial asthma, underwent surgery for an inguinal hernia. Forty-three minutes subsequent to spinal anesthesia, the patient complained suddenly of dyspnea with wheezing. Blood pressure decreased and skin eruption was observed on his chest. Postoperative laboratory tests revealed high IgE concentration, and a skin test confirmed an allergy to latex. The patient's allergic reaction was easily overlooked because of his history of bronchial asthma and the possibility that the hypotension was caused by the high spinal anesthesia. Latex allergy should be considered in any suspicious case presenting with these symptoms during surgery. After recovery, a skin test should be used to confirm the allergy to avoid repeated allergic episodes.

  9. Extractable protein content of radiation vulcanized natural rubber latex films

    International Nuclear Information System (INIS)

    Ma'zam Md Said; Wan Manshol Wan Zin

    1996-01-01

    The effects of processing conditions on extractable protein content of coagulant dipped radiation vulcanized natural rubber latex films have been investigated. Drying of wet-gel of radiation vulcanized latex films even at a relatively low temperature of 70 degree C resulted in increases of extractable protein content of the films. The extractable protein content is dependent upon both the temperature and time of drying of wet-gel deposit. Wet-gel leaching of film alone is not adequate to reduce the extractable protein content of films to low levels. Combination of wet-gel leaching, post-leaching, a dip in corn starch slurry, followed by drying at a low temperature of 70 degree C reduces the extractable protein content of films to very low levels

  10. Extractable protein of radiation vulcanized natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Soebianto, Y.S. [Center for Research and Development of Isotopes and Radiation Technology, BATAN, Jakarta (Indonesia); Upul, R.M. [Rubber Research Institute of Sri Lanka, Ratmalana (Sri Lanka); Makuuchi, K.; Yoshii, F.; Kume, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2000-03-01

    A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) as much as 3 phr in three different processes: added to RVNRL, added to re-centrifuged RVNRL, and added to RVNRL followed by centrifugation. The protein content was determined by enhanced BCA method, and identified by SDS-PAGE analysis. Addition of WSP followed by centrifugation reduces EP up to the minimum protein detection, and shortens the leaching time to 20-30 min. SDS-PAGE analysis confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The molecular weight of WSP dictates the efficiency of protein removal. (author)

  11. INHIBITION EFFECT OF FLAVONOID EXTRACT OF Euphorbia Guyoniana ON THE CORROSION OF MILD STEEL IN H2SO4 MEDIUM

    OpenAIRE

    S. Chihi; N. Gherraf; B. Alabed; S. Hameurlain

    2009-01-01

    The influence of flavonoids extracts of three parts of Euphorbia Guyoniana towards the corrosion of type API 5L X52 steel in 15% H2SO4 has been evaluated by weight loss method and polarization technique. The results showed that extracts are a good inhibitors for API 5L X52 steel in this medium. The corrosion inhibition efficiency increases on increasing plant extracts concentration. The inhibition is attributed to the adsorption of the surface of the metal. Potentiodynamic polarization result...

  12. Antimicrobial Activity of Extracts from Leaves, Stems and Flowers of Euphorbia macroclada against plant pathogenic fungi

    OpenAIRE

    K. Al-Mughrabi

    2003-01-01

    Extracts drawn from dried and powdered flowers, stems and leaves of Euphorbia macroclada with some organic solvents were tested for antimicrobial effect against the fungi Verticillium dahliae, Fusarium oxysporum, Rhizopus stolonifer, Penicillium italicum, Rhizoctonia solani, Alternaria solani, Stemphylium solani, Cladosporium sp., Mucor sp., and Pythium sp. The strongest inhibitory effect of the extracts was observed against R. solani, V. dahliae, F. oxysporum, Pythium sp. and R. ...

  13. Quantitative Analysis of Ingenol in Euphorbia species via Validated Isotope Dilution Ultra-high Performance Liquid Chromatography Tandem Mass Spectrometry

    Czech Academy of Sciences Publication Activity Database

    Béres, T.; Dragull, K.; Pospíšil, Jiří; Tarkowská, Danuše; Dančák, M.; Bíba, Ondřej; Tarkowski, P.; Doležal, K.; Strnad, Miroslav

    2018-01-01

    Roč. 29, č. 1 (2018), s. 23-29 ISSN 0958-0344 R&D Projects: GA ČR GA17-14007S; GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Euphorbia genus * ingenol * isotope-dilution method * mass spectrometry * ultra-high performance liquid chromatography Subject RIV: FD - Oncology ; Hematology OBOR OECD: Analytical chemistry Impact factor: 2.292, year: 2016

  14. A latex metabolite benefits plant fitness under root herbivore attack

    OpenAIRE

    Huber, M.; Epping, J.; Gronover, C.S.; Fricke, J.; Aziz, Z.; Brillatz, T.; Swyers, M.; Köllner, T.G.; Vogel, H.; Hammerbacher, A.; Triebwasser-Freese, D.; Robert, C.A.M.; Verhoeven, K.; Preite, V.; Gershenzon, J.

    2016-01-01

    Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major n...

  15. The entry of free radicals into polystyrene latex particles

    International Nuclear Information System (INIS)

    Adams, M.E.; Trau, M.; Gilbert, R.C.; Napper, D.R.

    1988-01-01

    Mechanistic understanding of the processes governing the kinetics of emulsion polymerization has both scientific and technical interest. One component of this process that is poorly understood at present is that of free radical entry into latex particles. Measurements were made of the entry rate coefficient as a function of temperature for free radicals entering polystyrene latex particles in seeded emulsion polymerizations initiated by γ-rays. The activation energy for entry was found to be less than 24 ± 3 kJ mol -1 , consistent with entry being controlled by a physical (e.g. diffusional) rather than a chemical process. Measurement of the entry rate coefficient as a function of the γ-ray dose rate suggested that the factors that determine the entry rate when the primary free radicals are uncharged are similar to those that determine the entry rate for charged free radicals derived from chemical initiation by peroxydisulfate. This result was consistent with measurements of the entry rate coefficient of charged free radicals derived from peroxydisulfate; these data were found to be virtually independent of both the extent of the latex surface coverage by the anionic surfactant sodium dodecyl sulfate and the ionic strength of the continuous phase. The data refute several proposals given in the literature for the rate-determining step for entry, being inconsistent with control by collision of free radicals with the latex particles, surfactant desorption, and an electrostatic barrier arising from the colloidal nature of the entering free radical. The origin of the activation energy for entry remains obscure

  16. Radiation vulcanised natural rubber latex (RVNRL) market and challenges

    International Nuclear Information System (INIS)

    Wan Manshol Wan Zin; Najib Mohamad Zakey; Chai Chee Keong

    2000-01-01

    RVNRL has the required properties and proven useful for the manufacturing of examination gloves, balloons and finger cots at industrial scale. To date only RVNRL finger cots are available in the market. Problems and challenges for the market of other products are identified. Further success in the on going research activities will be the reference for more applications of RVNRL in the relevant industry to produce natural rubber latex products of more competitive values

  17. Minimizing surgical skin incision scars with a latex surgical glove.

    Science.gov (United States)

    Han, So-Eun; Ryoo, Suk-Tae; Lim, So Young; Pyon, Jai-Kyung; Bang, Sa-Ik; Oh, Kap-Sung; Mun, Goo-Hyun

    2013-04-01

    The current trend in minimally invasive surgery is to make a small surgical incision. However, the excessive tensile stress applied by the retractors to the skin surrounding the incision often results in a long wound healing time and extensive scarring. To minimize these types of wound problems, the authors evaluated a simple and cost-effective method to minimize surgical incision scars based on the use of a latex surgical glove. The tunnel-shaped part of a powder-free latex surgical glove was applied to the incision and the dissection plane. It was fixed to the full layer of the dissection plane with sutures. The glove on the skin surface then was sealed with Ioban (3 M Health Care, St. Paul, MN, USA) to prevent movement. The operation proceeded as usual, with the retractor running through the tunnel of the latex glove. It was possible to complete the operation without any disturbance of the visual field by the surgical glove, and the glove was neither torn nor separated by the retractors. The retractors caused traction and friction during the operation, but the extent of damage to the postoperative skin incision margin was remarkably less than when the operation was performed without a glove. This simple and cost-effective method is based on the use of a latex surgical glove to protect the surgical skin incision site and improve the appearance of the postoperative scar. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  18. The criteria and the design of MINT's latex irradiator

    International Nuclear Information System (INIS)

    Razali Hamzah; Muhd Khairi Muhd Said; Muhd Ariff Hamzah; Wan Manshol Wan Zin; Wan Abd Hadi Wan Abu Bakar; Muhd Noor Muhd Yunus

    1996-01-01

    The demand for RVNRL is continually on the upsurge and the present irradiation technique at the present SINAGAMA plant is not sufficient and practical to meet the demand. A number of conceptual designs were evolved to design according to the requirements of cost-effective and highly efficient plant. The number of options are described. In 1994 MINT work with NUKEM to build an automatic continuous latex irradiation plant

  19. The polymerization of aniline in polystyrene latex particles

    Czech Academy of Sciences Publication Activity Database

    Blinova, Natalia V.; Reynaud, S.; Roby, F.; Trchová, Miroslava; Stejskal, Jaroslav

    2010-01-01

    Roč. 160, 15/16 (2010), s. 1598-1602 ISSN 0379-6779 R&D Projects: GA AV ČR IAA400500905; GA ČR GA203/08/0686; GA ČR GA202/09/1626 Institutional research plan: CEZ:AV0Z40500505 Keywords : polyaniline * polystyrene latex * polyaniline-polystyrene composite Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.871, year: 2010

  20. Atividade residual de diuron, oxyfluorfen e prometryne no controle de Euphorbia heterophylla Residual activity of diuron, oxyfluorfen, and prometryne for Euphorbia heterophylla control

    Directory of Open Access Journals (Sweden)

    R.S. Oliveira Jr.

    2012-09-01

    Full Text Available As aplicações de herbicidas em pré-emergência têm por finalidade a obtenção da atividade residual no início do ciclo das culturas. Assim, o objetivo deste trabalho foi avaliar a atividade residual dos herbicidas diuron, oxyfluorfen e prometryne, aplicados isoladamente ou em misturas, no controle de Euphorbia heterophylla. Oito experimentos foram conduzidos em casa de vegetação, aplicando-se doses dos herbicidas ou das misturas aos 30, 20, 10 e 0 dias antes da semeadura da planta daninha (DAS. Com o diuron e prometryne, foram observados controles satisfatórios até 20 DAS nas doses a partir de 1,07 e 1,6 kg ha-1, respectivamente. Quanto ao oxyfluorfen, foi registrado um período residual inferior, obtendo-se controle mínimo de 80% até 10 DAS nas doses a partir de 0,324 kg ha-1. Em relação às misturas dos herbicidas, a mistura diuron+prometryne promoveu controle superior a 85% por períodos de até 30 dias, quando aplicada na menor dose (1+2 kg ha-1, e de 20 dias, quando aplicada na dose de 2+1 kg ha-1. Visando obter esse mesmo patamar de controle por 30 dias, foi necessário 1+0,288 kg ha-1 da mistura diuron+oxyfluorfen. A mistura prometryne+oxyfluorfen apresentou um mínimo de 80% de controle no período de 10 dias, quando utilizada a dose de 1+0,192 kg ha-1.Pre-emergence herbicide applications are designed to obtain residual activity at the beginning of the crop cycle. The objective of this study was to evaluate the residual activity of diuron, oxyfluorfen, and prometryne, applied alone or in mixture, to control Euphorbia heterophylla. Eight experiments were conducted under greenhouse conditions, by applying herbicide doses or mixtures at 30, 20, 10, and 0 days before weed sowing (DBWS.With diuron and prometryne, satisfactory controls were observed at doses up to 20 DBWS, from 1.07 to 1.6 kg ha-1, respectively. As for oxyfluorfen, a lower residual period was verified, with a minimum gaining control of at least 80% being obtained

  1. Progress in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Makuuchi, Keizo

    2000-01-01

    Vulcanization dose defined as the radiation dose at which cross-linked natural rubber in latex has the maximum tensile strength can be reduced by adding carbon tetrachloride as a reaction accelerator. The radiation vulcanization of natural rubber latex was selected as one of regional projects of IAEA in 1989 and a pilot plant was built in Jakarta. The products from it were evaluated during 1983-1985, followed by IAEA decision to support the continued R and D study at Takasaki, JAERI. Various factors to improve the properties of the products have been studied. Several advantages of the process over conventional method, such as absence of N-nitrosoamines, low cytotoxicity, decomposability in the environment, transparency and softness, were confirmed. The technology has been transferred toward commercial application in Thailand, and pilot plants being set up in Indonesia, India, Malaysia and Thailand. Moreover, the process was found to be effective in reducing protein remaining in natural rubber latex products and the initial investment and irradiation cost was found to be greatly reduced by employing low energy electron accelerator. This paper reviews such progress. (S. Ohno)

  2. CDNA library from the Latex of Hevea brasiliensis

    Directory of Open Access Journals (Sweden)

    Wilaiwan Chotigeat

    2010-12-01

    Full Text Available Latex from Hevea brasiliensis contains 30-50% (w/w of natural rubber (cis-1,4-polyisoprene, the important rawmaterial for many rubber industries. We have constructed a cDNA library from the latex of H. brasiliensis to investigate theexpressed genes and molecular events in the latex. We analyzed 412 expressed sequence tags (ESTs. More than 90% of theEST clones showed homology to previously described sequences in public databases. Functional classification of the ESTsshowed that the largest category were proteins of unknown function (30.1%, 11.4% of ESTs encoded for rubber synthesisrelatedproteins (RS and 8.5% for defense or stress related proteins (DS. Those with no significant homology to knownsequences (NSH accounted for 8.7%, primary metabolism (PM and gene expression and RNA metabolism were 7.8% and6.6%, respectively. Other categories included, protein synthesis-related proteins (6.6%, chromatin and DNA metabolism(CDM 3.9%, energy metabolism (EM 3.4%, cellular transport (CT 3.2%, cell structure (CS 3.2%, signal transduction (ST2.2%, secondary metabolism (SM 1.7%, protein fate (PF 2.2%, and reproductive proteins (RP 0.7%.

  3. Extractable proteins from field radiation vulcanized natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Parra, Duclerc F. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil)]. E-mail: dfparra@ipen.br; Pinto Martins, Carlos Felipe [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil); Collantes, Hugo D.C. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil); Lugao, Ademar B. [Chemical and Environmental Centre, Nuclear Energy Research Institute, Av. Lineu Prestes, 2242-CEP Sao Paulo (Brazil)

    2005-07-01

    The type I allergy associated with the use of natural rubber latex (NRL) products is caused by the NRL proteins leached by the sweat or other body fluids. Makuuchi's group proposed for the first time the proteins removal by the addition of water-soluble polymers (WSP) on radiation vulcanization of natural rubber latex (RVNRL) that is a promising process under development in many countries. In this study, Brazilian field natural rubber was irradiated with a {sup 60}Co gamma source to reduce the content of WSP in the final product. WSP was used as additive to improve the extraction of protein. After irradiation the RVNRL was centrifuged to extract the WSP and proteins. The analytical methodology for protein content was based on the modified Lowry method according to ASTM D5712. Protein determination was carried out in serum of latex and in the extracts of the gloves. The concentration of extractable water-soluble proteins in serum of irradiated field NRL (NRL1), not irradiated one (NRL2); of twice centrifuged sample with polymer additive NRL (NRL3) and of the glove manufactured (NRLG) are compared with commercial glove (CG). The irradiation process increases the extractable water-soluble proteins, EP, as reported in the literature. In this study the use of polymeric additive on the bi-centrifugation process to remove protein was successful and the EP of the glove obtained in NRL3 was at around 40% of the commercial glove.

  4. Efficacy of protection by latex gloves during orthodontic therapy.

    Science.gov (United States)

    Doll, G M; Zentner, A; Balan, R; Sergl, H G

    2000-01-01

    The wearing of gloves during orthodontic or dental treatment is generally indicated for reasons of hygiene and protection against infection. This study was aimed at determining the extent and localization of perforations caused by the various orthodontic treatment techniques and interrupting the infection barrier. The impermeability was tested by means of a water retention test according to European standard EN 455, Part 1, performed on 1600 Centramed (Centramed, Koblenz), Tekmedic and SafeEx non-sterile disposable latex gloves (both by Safe Med, Switzerland) and Safe Gan latex gloves with an additional acrylate coating (also by Safe Med). The perforation rate in unused gloves was between 0.5% and 7.5%, rising on average to 11% with increasing use. 36% of the total number of lesions resulted from handling removable appliances, and 57% from handling fixed appliances, especially when replacing arch wires and elastics. Most lesions were in the thumb, index finger and palm region. Only 18% of the defects were noticed by the dentists themselves. The gloves worn by beginners in their first year of postgraduate orthodontic training had about twice as many defects as those worn by qualified orthodontists. When patients with an increased risk of infection are to be treated, additional hand disinfection measures should be taken and 2 pairs of gloves worn in view of the relatively unreliable protection offered by commercially available latex gloves.

  5. Extractable protein of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Soebianto, Y.S.; Ratnayake, U.M.; Makuuchi, Keizo; Yoshii, Fumio; Kume, Tamikazu

    2000-01-01

    Protein remained in the latex products are reported to cause serious allergy. A new method to reduce the protein level in the latex products by irradiation is reported. Water soluble protein (WSP) solution (10%) was added into radiation vulcanized NR latex (RVNRL) in three different processes. The amount of WSP was 3 phr. It was only added to RVNRL (standard), added to re-centrifuged RVNRL (pre-centrifugation), and added to RVNRL followed by centrifugation (post-centrifugation). The protein content was determined by enhanced BCA method, and identified by SDS-PAGE. Extractable protein (EP) from the rubber has been reduced up to the minimum protein detection by combining WSP addition and centrifugation. Short leaching time (20-30 min.) can be achieved after the combine treatment, and SDS-PAGE confirms the reduction of soluble protein in the serum phase, and disappearance of protein bands in the rubber extract. Protein-WSP interaction produces water soluble complex, and removed by centrifugation. The efficiency of protein removal by WSP depends on its molecular weight of WSP which relates to its water solubility. (author)

  6. Radiation vulcanization of natural rubber latex using irradiation n-butyl acrylate aqueous emulsion as sensitizer

    International Nuclear Information System (INIS)

    Vo Van Thien; Nguyen Quoc Hien; Keizo Makuuchi; Fumio Yoshii

    2000-01-01

    Natural rubber latex was vulcanized by gamma radiation with n-butyl acrylate aqueous emulsion irradiated at dose of 1.5 kGy as sensitizer. The total solid content of latex increases on the irradiation dose. The viscosity of latex on the standing time was investigated and became stable after one month of storage. The gel content of latex films increasing with irradiation dose and attained more than 94% at dose of 10 kGy. Tensile strength of films reached the values of 31MPa; 30 Mpa and 25 Mpa at vulcanization doses of 20 kGy, 15 kGy and 8 kGy for the concentrations of sensitizer 7 phr, 9 phr and 13 phr respectively. Elongation at break decreases as increasing dose. Tear strength of rubber films was from 30-40 N/mm. The tackiness of latex films decreases and smell of vulcanized latex is almost negligible. (author)

  7. Histamine mediates the pro-inflammatory effect of latex of Calotropis procera in rats

    Directory of Open Access Journals (Sweden)

    Yatin M. Shivkar

    2003-01-01

    Full Text Available Introduction: Calotropis procera is known to produce contact dermatitis and the latex of this plant produces intense inflammation when injected locally. However, the precise mode of its pro-inflammatory effect is not known. In present study we have pharmacologically characterized the inflammation induced by latex of C. procera in a rat paw edema model and determined the role of histamine in latex-induced inflammation.

  8. Latex agglutination test (LAT) for the diagnosis of typhoid fever.

    Science.gov (United States)

    Sahni, Gopal Shankar

    2013-06-01

    The efficacy of latex agglutination test in the rapid diagnosis of typhoid fever was studied and the result compared with that of blood culture. This study included 80 children suffering from typhoid fever, among which 40 were confirmed by blood culture isolation and 40 had possible typhoid fever based on high Widal's titre (a four-fold rise in the titre of antibody to typhi "O" and "H" antigen was considered as a positive Widal's test result). Eighty children, 40 with febrile illness confirmed to be other than typhoid and 40 normal healthy children were used as negative controls. The various groups were: (i) Study group ie, group I had 40 children confirmed by culture isolation of Salmonella typhi(confirmed typhoid cases). (ii) Control groups ie, (a) group II with 40 febrile controls selected from paediatrics ward where cause other than S typhi has been established, (b) group III with 40 afebrile healthy controls that were siblings of the children admitted in paediatric ward for any reason with no history of fever and TAB vaccination in the last one year, and (c) group IV with 40 children with high Widal's titre in paired sera sample. Widal's test with paired sera with a one week interval between collections were done in all 40 patients. Latex aggtutination test which could detect 900 ng/ml of antigen as observed in checker board titration, was positive in all 40 children from group I who had positive blood culture and in 30 children from group IV who had culture negative and had high Widal's titre positive. Latex agglutination test was positive in 4 children in group II and none in group III. Using blood culture positive cases as true positive and children in groups II and III as true negative, the test had a sensitivity of 100% and specificity of 96%. Latex agglutination test was found to be significantly sensitive (100%) and specific (96%) and could detect 75% more cases in group IV (possible typhoid cases). Thus latex agglutination test can be used for rapid

  9. Characteristics of Red Algae Bioplastics/Latex Blends under Tension

    Directory of Open Access Journals (Sweden)

    M. Nizar Machmud

    2013-10-01

    Full Text Available Cassava, corn, sago and the other food crops have been commonly used as raw materials to produce green plastics. However, plastics produced from such crops cannot be tailored to fit a particular requirement due to their poor water resistance and mechanical properties. Nowadays, researchers are hence looking to get alternative raw materials from the other sustainable resources to produce plastics. Their recent published studies have reported that marine red algae, that has been already widely used as a raw material for producing biofuels, is one of the potential algae crops that can be turned into plastics. In this work, Eucheuma Cottonii, that is one of the red alga crops, was used as raw material to produce plastics by using a filtration technique. Selected latex of Artocarpus altilis and Calostropis gigantea was separately then blended with bioplastics derived from the red algae, to replace use of glycerol as plasticizer. Role of the glycerol and the selected latex on physical and mechanical properties of the red algae bioplastics obtained under a tensile test performed at room temperature are discussed. Tensile strength of some starch-based plastics collected from some recent references is also presented in this paperDoi: 10.12777/ijse.5.2.81-88 [How to cite this article: Machmud, M.N., Fahmi, R.,  Abdullah, R., and Kokarkin, C.  (2013. Characteristics of Red Algae Bioplastics/Latex Blends under Tension. International Journal of Science and Engineering, 5(2,81-88. Doi: 10.12777/ijse.5.2.81-88

  10. A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack.

    Directory of Open Access Journals (Sweden)

    Meret Huber

    2016-01-01

    Full Text Available Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg. decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha, and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground.

  11. A Latex Metabolite Benefits Plant Fitness under Root Herbivore Attack.

    Science.gov (United States)

    Huber, Meret; Epping, Janina; Schulze Gronover, Christian; Fricke, Julia; Aziz, Zohra; Brillatz, Théo; Swyers, Michael; Köllner, Tobias G; Vogel, Heiko; Hammerbacher, Almuth; Triebwasser-Freese, Daniella; Robert, Christelle A M; Verhoeven, Koen; Preite, Veronica; Gershenzon, Jonathan; Erb, Matthias

    2016-01-01

    Plants produce large amounts of secondary metabolites in their shoots and roots and store them in specialized secretory structures. Although secondary metabolites and their secretory structures are commonly assumed to have a defensive function, evidence that they benefit plant fitness under herbivore attack is scarce, especially below ground. Here, we tested whether latex secondary metabolites produced by the common dandelion (Taraxacum officinale agg.) decrease the performance of its major native insect root herbivore, the larvae of the common cockchafer (Melolontha melolontha), and benefit plant vegetative and reproductive fitness under M. melolontha attack. Across 17 T. officinale genotypes screened by gas and liquid chromatography, latex concentrations of the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G) were negatively associated with M. melolontha larval growth. Adding purified TA-G to artificial diet at ecologically relevant concentrations reduced larval feeding. Silencing the germacrene A synthase ToGAS1, an enzyme that was identified to catalyze the first committed step of TA-G biosynthesis, resulted in a 90% reduction of TA-G levels and a pronounced increase in M. melolontha feeding. Transgenic, TA-G-deficient lines were preferred by M. melolontha and suffered three times more root biomass reduction than control lines. In a common garden experiment involving over 2,000 T. officinale individuals belonging to 17 different genotypes, high TA-G concentrations were associated with the maintenance of high vegetative and reproductive fitness under M. melolontha attack. Taken together, our study demonstrates that a latex secondary metabolite benefits plants under herbivore attack, a result that provides a mechanistic framework for root herbivore driven natural selection and evolution of plant defenses below ground.

  12. Nitrogen removal from concentrated latex wastewater by land treatment

    Directory of Open Access Journals (Sweden)

    Vikanda Thongnuekhang

    2004-05-01

    Full Text Available Most of the concentrated latex factories in the South of Thailand discharge treated wastewater that contains high level of nitrogen to a nearby river or canals leading to a water pollution problem. A study of land treatment system was conducted to treat and utilize nitrogen in treated wastewater from the concentrated latex factory. The experimental pilot-scale land treatment system was constructed at the Faculty of Engineering, Prince of Songkla University, Hat Yai Campus. It consisted of water convolvulus (Ipomea aquatica, I. Reptans, tropical carpet grass (Axonopus compresus (Swartz Beav. and control unit (no plantation. The treated wastewater from the stabilization pond system of the selected concentrated latex factoryin Songkhla was used to irrigate each experimental unit. Influent and effluent from the experimental units were analyzed for TKN, NH3-N, Org-N, NO3 --N, NO2 --N, BOD5, sulfate, pH and EC. The land treatment system resulted a high removal efficiency for nitrogen. Tropical carpet grass provided higher removal efficiency than other units for all parameters. The removal efficiency of water convolvulus and control unit were not significantly different. The average removal efficiency of TKN, NH3-N, Org-N, BOD5 and sulfate for tropical carpet grass unit were 92, 97, 61, 88 and 52%, for water convolvulus unit were 75, 80, 43, 41 and 30%, and for control unit were 74, 80, 41, 31 and 28%, respectively. Mass balance of nitrogen transformation was conducted. It revealed that plant uptake was the major mechanism for nitrogen removal in land treatment.

  13. Antioxidant activity and concentration of secondary metabolites in the plant parts of Euphorbia cyparissias L.

    Directory of Open Access Journals (Sweden)

    Stanković Milan S.

    2014-01-01

    Full Text Available This paper presents the results of a screening of nine different extracts from the plant parts (leaves, flowers and stems of Euphorbia cyparissias for total phenolic content, concentration of flavonoids and in vitro antioxidant activity. Main reason for this study is the determination of these parameters and their variability among plant parts and plant extracts obtained by different solvents, respectively. Obtained amounts for total phenolic content ranged from 10.76 to 40.72 mg GA/g. The concentration of flavonoids varied from 34.32 to 134.34 mg Ru/g. The IC50 values of antioxidant activity varied from 88.48 to 2891.08 μg/ml. Results obtained from the different plant parts were of uneven value. Great variability of the studied parameters was observed when comparing the effectiveness of the used solvents. The acetone extracts from stems contain the greatest concentrations of phenolic compounds, especially flavonoids, and showed high antioxidant activity. According to our research, plant parts from E. cyparissias can be regarded as promising candidates for natural plant sources with high value of biological compounds.

  14. The site of 2,4-D accumulation in Euphorbia helioscopia L

    International Nuclear Information System (INIS)

    Sakri, F.A.

    1990-01-01

    The distribution and accumulation of the herbicide 2,4-D have been studied by 14 C labelling and by tracing due to the autoradiographic method in young plants of Euphorbia helioscopia L. (milkweed). Milkweed plants were grown in a greenhouse at 30deg C under 16 hrs. photoperiod for about two weeks. The two lower opposite leaves, the cotyledons, were used as sites for 14 C-labelled 2,4-D application. The autoradiograph of the whole plants revealed that labelled 2,4-D movement was predominantly basipetal into the root as well as acropetal into the shoot apex. The 2,4-D movement has by-passed all the matured leaves in its movement from active sources to active sinks. The microautoradiography indicated that 2,4-D can accumulate to a considerable amount both in the parenchyma of the pith and in the cortical cells. It is concluded that 2,4-D is transported through phloem cells when applied to the healthy long leaves. (author)

  15. Use of raw Euphorbia tirucalli extract for inhibition of ascitic Ehrlich tumor

    Directory of Open Access Journals (Sweden)

    Orlando José dos Santos

    Full Text Available Objective: to evaluate the effect of the Euphorbia tirucalli hydroalcoholic extract (ETHE on the development of Ehrlich Tumor, in its ascitic form. Methods: we intraperitoneally inoculated 15 Swiss mice with 10.44 x 107 cells of Ehrlich Tumor and divided them in two groups one day after: ETHE Group (eight mice, treated with a dosage of 125 mg/kg/day of EHTE for five days; and Control Group (seven mice, treated only with 0.9% isotonic saline solution over the same period. The treatment was done by gavage. Ten days after inoculation, four mice from each group were sacrificed for quantification of tumor cell number, ascitic fluid volume and bone marrow cell number. The remaining animals were maintained to evaluate survival. Results: The ascitic fluid volume and the tumor cell number were decreased in the ETHE group when compared with the control group, but with no statistical significance. On the other hand, survival was higher in the ETHE group, as well as the number of bone marrow cells. Conclusion: Treatment with ETHE after inoculation of Ehrlich Tumor decreases its development and increases survival and the bone marrow cellularity, thus reducing the myelosuppression present in the Ehrlich Tumor bearing mice.

  16. Microscopic processes ruling the bioavailability of Zn to roots of Euphorbia pithyusa L. pioneer plant.

    Science.gov (United States)

    Medas, Daniela; De Giudici, Giovanni; Casu, Maria Antonietta; Musu, Elodia; Gianoncelli, Alessandra; Iadecola, Antonella; Meneghini, Carlo; Tamburini, Elena; Sprocati, Anna Rosa; Turnau, Katarzyna; Lattanzi, Pierfranco

    2015-02-03

    Euphorbia pithyusa L. was used in a plant growth-promoting assisted field trial experiment. To unravel the microscopic processes at the interface, thin slices of E. pithyusa roots were investigated by micro-X-ray fluorescence mapping. Roots and rhizosphere materials were examined by X-ray absorption spectroscopy at the Zn K-edge, X-ray diffraction, and scanning electron microscopy. Results indicate some features common to all the investigated samples. (i) In the rhizosphere of E. pithyusa, Zn was found to exist in different phases. (ii) Si and Al are mainly concentrated in a rim at the epidermis of the roots. (iii) Zn is mostly stored in root epidermis and does not appear to be coordinated to organic molecules but mainly occurs in mineral phases such as Zn silicates. We interpreted that roots of E. pithyusa significantly promote mineral evolution in the rhizosphere. Concomitantly, the plant uses Si and Al extracted by soil minerals to build a biomineralization rim, which can capture Zn. This Zn silicate biomineralization has relevant implications for phytoremediation techniques and for further biotechnology development, which can be better designed and developed after specific knowledge of molecular processes ruling mineral evolution and biomineralization processes has been gained.

  17. Potential Use of Euphorbia hirta for Dengue: A Systematic Review of Scientific Evidence

    Directory of Open Access Journals (Sweden)

    Sashini D. Perera

    2018-01-01

    Full Text Available Euphorbia hirta commonly known as Tawa-Tawa is a plant used in folklore medicine in the Philippines for the treatment of dengue. Though, E. hirta has been extensively investigated for numerous bioactivities, limited studies have been conducted on the antidengue activity. Thus, the present study provides a comprehensive review of studies conducted on the antidengue activity of E. hirta. A systematic literature survey was carried out in scientific databases, PubMed®, Scopus, and Google Scholar, for research carried on the antidengue activity of E. hirta. The literature search identified a total of 867 articles: databases PubMed = 6, Scopus SciVerse® = 423, and Google Scholar = 437; one additional article was identified by searching reference lists. Eight full papers were entitled to the review; out of those, two studies focused on ethnobotanical surveys, three on animal experiments, one on human trial, and two on in vitro antiviral activities, and one was computational study. The available evidence conclusively demonstrates the potential of E. hirta against dengue as it holds significant antiviral and platelet increasing activities. However, the number of studies conducted to validate its antidengue activity was found to be inadequate. Hence, well-controlled clinical trials and contemporary pharmacological approaches including activity guided fractionation and elucidation of the mode of action are encouraged to establish the use of E. hirta for dengue.

  18. Comparison of supercritical fluid and Soxhlet extractions for the quantification of hydrocarbons from Euphorbia macroclada.

    Science.gov (United States)

    Ozcan, Adnan; Ozcan, Asiye Safa

    2004-10-08

    This study compares conventional Soxhlet extraction and analytical scale supercritical fluid extraction (SFE) for their yields in extracting of hydrocarbons from arid-land plant Euphorbia macroclada. The plant material was firstly sequentially extracted with supercritical carbon dioxide, modified with 10% methanol (v/v) in the optimum conditions that is a pressure of 400atm and a temperature of 50 degrees C and then it was sonicated in methylene chloride for an additional 4h. E. macroclada was secondly extracted by using a Soxhlet apparatus at 30 degrees C for 8h in methylene chloride. The validated SFE was then compared to the extraction yield of E. macroclada with a Soxhlet extraction by using the Student's t-test at the 95% confidence level. All of extracts were fractionated with silica-gel in a glass column to get better hydrocarbon yields. Thus, the highest hydrocarbons yield from E. macroclada was achieved with SFE (5.8%) when it compared with Soxhlet extractions (1.1%). Gas chromatography (GC) analysis was performed to determine the quantitative hydrocarbons from plant material. The greatest quantitative hydrocarbon recovery from GC was obtained by supercritical carbon dioxide extract (0.6mgg(-1)).

  19. Nectar regulation in Euphorbia tithymaloides L., a hummingbird-pollinated Euphorbiaceae.

    Science.gov (United States)

    Veiga Blanco, T; Galetto, L; Machado, I C

    2013-09-01

    Floral sexual phases can differ in nectar production and might be under selective pressure by pollinators. We studied Euphorbia tithymaloides, which has inflorescences that are initially female and then hermaphroditic. Volume and concentration of nectar were measured in both stages. Nectar production and the effect of extractions were determined using sets of bagged inflorescences; inflorescences in the hermaphroditic phase had higher values of nectar concentration, volume and sugar mass than inflorescences in the female phase. Nectar resorption was detected in senescent inflorescences. To test for homeostatic nectar regulation, artificial nectar was added and the response assessed after 24 h. The experiments showed that concentration and sugar mass are regulated within a narrow range, and the homeostatic points differ between the two sexual phases. These differences in nectar can be detected by hummingbirds, which prefer the female stage. Resorption and secretion seem to be part of a homeostatic mechanism by which nectar attributes are maintained to optimise sugar recovery. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Effect of Pseudomonas putida on Growth and Anthocyanin Pigment in Two Poinsettia (Euphorbia pulcherrima Cultivars

    Directory of Open Access Journals (Sweden)

    Ramon Zulueta-Rodriguez

    2014-01-01

    Full Text Available Pseudomonas putida is plant growth promoting rhizobacteria (PGPR that have the capacity to improve growth in plants. The purpose of this study was to determine growth and anthocyanin pigmentation of the bracts in two poinsettia Euphorbia pulcherrima cultivars (Prestige and Sonora Marble using three strains of P. putida, as well as a mixture of the three (MIX. Comparison with the control group indicated for the most part that Prestige grew better than the Sonora Marble cultivars with the PGPR strains. Prestige with the MIX strain grew better compared to control for the number of cyathia (83 versus 70.4, volume of roots (45 versus 35 cm3, number of leaves (78 versus 58, and area of leaf (1,788 versus 1,331 cm2, except for the number of flowers (8.8 versus 11.6. To the naked eye, coloration of plants appeared identical in color compared to the control group. For all plants with P. putida strains, there was less anthocyanin pigment, but biomass was always greater with PGPR strains. Nevertheless, to the naked eye, the coloration of the plants appeared identical in color compared to the control group. This is the first study reporting the positive effects of P. putida rhizobacteria treatments on growth of poinsettia cultivars.

  1. Reactivation of HIV-1 from Latency by an Ingenol Derivative from Euphorbia Kansui.

    Science.gov (United States)

    Wang, Pengfei; Lu, Panpan; Qu, Xiying; Shen, Yinzhong; Zeng, Hanxian; Zhu, Xiaoli; Zhu, Yuqi; Li, Xian; Wu, Hao; Xu, Jianqing; Lu, Hongzhou; Ma, Zhongjun; Zhu, Huanzhang

    2017-08-25

    Cells harboring latent HIV-1 pose a major obstacle to eradication of the virus. The 'shock and kill' strategy has been broadly explored to purge the latent reservoir; however, none of the current latency-reversing agents (LRAs) can safely and effectively activate the latent virus in patients. In this study, we report an ingenol derivative called EK-16A, isolated from the traditional Chinese medicinal herb Euphorbia kansui, which displays great potential in reactivating latent HIV-1. A comparison of the doses used to measure the potency indicated EK-16A to be 200-fold more potent than prostratin in reactivating HIV-1 from latently infected cell lines. EK-16A also outperformed prostratin in ex vivo studies on cells from HIV-1-infected individuals, while maintaining minimal cytotoxicity effects on cell viability and T cell activation. Furthermore, EK-16A exhibited synergy with other LRAs in reactivating latent HIV-1. Mechanistic studies indicated EK-16A to be a PKCγ activator, which promoted both HIV-1 transcription initiation by NF-κB and elongation by P-TEFb signal pathways. Further investigations aimed to add this compound to the therapeutic arsenal for HIV-1 eradication are in the pipeline.

  2. Prevalence of Allergy to Natural Rubber Latex and Potential Cross Reacting Food in Operation Room Staff in Shiraz Hospitals -2006

    OpenAIRE

    H Nabavizade; R Amin

    2007-01-01

    Introduction & Objective: Allergic reactions to natural rubber latex have increased during past 10 years especially among health care workers and patients with high exposure to latex allergens. Allergic reaction to latex is related to many diseases like occupational asthma. This study was performed to determine the prevalence of allergy to natural rubber latex and potential cross reacting food in operation room staff in Shiraz hospitals. Materials & Methods: In this cross-sectional descr...

  3. Laboratory evaluation of a simple and rapid latex agglutination assay for the serodiagnosis of typhoid fever

    NARCIS (Netherlands)

    Abdoel, Theresia H.; Pastoor, Rob; Smits, Henk L.; Hatta, Mochammad

    2007-01-01

    A latex agglutination assay for the serodiagnosis of typhoid fever was evaluated on samples collected from patients with clinical suspicion of typhoid fever in South Sulawesi, Indonesia, where the disease is endemic. The latex assay is very easy to use, gives a rapid result and may be used as a

  4. Involvement of Ethylene in the Latex Metabolism and Tapping Panel Dryness of Hevea brasiliensis

    Science.gov (United States)

    Putranto, Riza-Arief; Herlinawati, Eva; Rio, Maryannick; Leclercq, Julie; Piyatrakul, Piyanuch; Gohet, Eric; Sanier, Christine; Oktavia, Fetrina; Pirrello, Julien; Kuswanhadi; Montoro, Pascal

    2015-01-01

    Ethephon, an ethylene releaser, is used to stimulate latex production in Hevea brasiliensis. Ethylene induces many functions in latex cells including the production of reactive oxygen species (ROS). The accumulation of ROS is responsible for the coagulation of rubber particles in latex cells, resulting in the partial or complete stoppage of latex flow. This study set out to assess biochemical and histological changes as well as changes in gene expression in latex and phloem tissues from trees grown under various harvesting systems. The Tapping Panel Dryness (TPD) susceptibility of Hevea clones was found to be related to some biochemical parameters, such as low sucrose and high inorganic phosphorus contents. A high tapping frequency and ethephon stimulation induced early TPD occurrence in a high latex metabolism clone and late occurrence in a low latex metabolism clone. TPD-affected trees had smaller number of laticifer vessels compared to healthy trees, suggesting a modification of cambial activity. The differential transcript abundance was observed for twenty-seven candidate genes related to TPD occurrence in latex and phloem tissues for ROS-scavenging, ethylene biosynthesis and signalling genes. The predicted function for some Ethylene Response Factor genes suggested that these candidate genes should play an important role in regulating susceptibility to TPD. PMID:26247941

  5. Isotactic polypropylene/carbon nanotube composites prepared by latex technology: Electrical conductivity study

    NARCIS (Netherlands)

    Grossiord, N.; Wouters, M.E.L.; Miltner, H.E.; Lu, K.; Loos, J.; Van Mele, B.; Koning, C.E.

    2010-01-01

    Several series of nanocomposites were prepared using a latex-based process, the main step of which consisted of mixing an aqueous suspension of exfoliated carbon nanotubes (CNTs) and a polymer latex. In the present work, a systematic study on the electrical properties of fully amorphous (polystyrene

  6. Synthesis and Characterization of Core-Shell Acrylate Based Latex and Study of Its Reactive Blends

    Directory of Open Access Journals (Sweden)

    Ying Nie

    2008-03-01

    Full Text Available Techniques in resin blending are simple and efficient method for improving the properties of polymers, and have been used widely in polymer modification field. However, polymer latex blends such as the combination of latexes, especially the latexes with water-soluble polymers, were rarely reported. Here, we report a core-shell composite latex synthesized using methyl methacrylate (MMA, butyl acrylate (BA, 2-ethylhexyl acrylate (EHA and glycidyl methacrylate (GMA as monomers and ammonium persulfate and sodium bisulfite redox system as the initiator. Two stages seeded semi-continuous emulsion polymerization were employed for constructing a core-shell structure with P(MMA-co-BA component as the core and P(EHA-co-GMA component as the shell. Results of Transmission Electron Microscopy (TEM and Dynamics Light Scattering (DLS tests confirmed that the particles obtained are indeed possessing a desired core-shell structural character. Stable reactive latex blends were prepared by adding the latex with waterborne melamine-formaldehyde resin (MF or urea-formaldehyde resin (UF. It was found that the glass transition temperature, the mechanical strength and the hygroscopic property of films cast from the latex blends present marked enhancements under higher thermal treatment temperature. It was revealed that the physical properties of chemically reactive latexes with core-shell structure could be altered via the change of crosslinking density both from the addition of crosslinkers and the thermal treatment.

  7. NR based curred latex material reclaimed with 2,2'-dibenzamidodiphenyldisulphide in truck tyre tread compound

    NARCIS (Netherlands)

    Rajan, V.V.; Dierkes, Wilma K.; Joseph, R.; Noordermeer, Jacobus W.M.

    2006-01-01

    It is observed that reclamation of natural rubber latex based rubber using 2,2'-dibenzamidodiphenyldisulphide as reclaiming agent is an optional methodology for recycling of waste latex rubber (WLR). For progressive replacement of virgin natural rubber by the reclaim, two alternatives curing system

  8. Thermodynamics of swelling of latex particles with two monomers: a sensitivity analysis

    NARCIS (Netherlands)

    Maxwell, I.A.; Noel, E.F.J.; Schoonbrood, H.A.S.; German, A.L.

    1993-01-01

    A sensitivity anal. is performed to det. at what conditions the simplified model for swelling of latex particles by two monomers or two solvents is valid. This model proposes that, inter alia, the fractions of two monomers in the latex particles and in the monomer droplets are equal. The model is a

  9. Towards anti-corrosion coatings from surfactant-free latexes based on maleic anhydride containing polymers

    NARCIS (Netherlands)

    Soer, W.J.; Ming, W.; Koning, C.E.; Benthem, van R.A.T.M.

    2008-01-01

    We report on the film formation of surfactant-free, artificial latexes based on copolymers containing maleic anhydride. Different metallic substrates, such as aluminum, steel and magnesium alloys, were coated with three different latexes. A commercial polyester based coating was used as a

  10. Residual monomer reduction in polymer latex products by extraction with supercritical carbon dioxide

    NARCIS (Netherlands)

    Aerts, M.; Meuldijk, J.; Kemmere, M.F.; Keurentjes, J.T.F.

    2011-01-01

    Extraction of residual monomer from a latex product with supercritical carbon dioxide ((sc)CO2) in a column was studied. Operating conditions were chosen at 35¿°C and 100 bar. For reducing the residual styrene level in a polystyrene latex from 104 ppm to 100¿ppm and from 104 ppm to 10¿ppm, a

  11. Elements of the LaTeX system for the development of large publications

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    This document presents gives a quick overview over the LATEX system from the viewpoint of the production of books and complex papers. Thereby it provides the starting point for the author's selection of a set of LATEX packages and the development of related commands....

  12. Resistence of Euphorbia Heterophylla L. to ALS-inhibiting herbicides in soybean Resistência de Euphorbia Heterophylla L. aos herbicidas inibidores da ALS na cultura da soja

    Directory of Open Access Journals (Sweden)

    Gerson Augusto Gelmini

    2005-10-01

    Full Text Available Herbicides are widely used in soybean for weed control, and the selection pressure attributed to the repeated use of herbicides with similar modes of action on the same site has caused selection for resistant biotypes within and among previously susceptible species, such as Euphorbia heterophylla L., in relation to ALS enzyme inhibitors, in the states of Paraná, Rio Grande do Sul, and São Paulo, Brazil. Seeds of E. heterophylla were collected to examine possible new cases of resistant populations and to test alternative herbicide treatments to manage these populations, in the Caarapó region, State of Mato Grosso do Sul, Brazil, in areas where plants of this species have survived continuous herbicide applications. The experiment was carried out under greenhouse conditions, where biotypes with a history of suspected resistance were compared with a known susceptible biotype. Several post-emergence herbicides were sprayed at zero, one, two, four, and eight times the recommended field application rates. Twenty days after application, plants were harvested, and control percentage and fresh weight were determined to establish dose-response curves, in the aim to obtain the resistance factor using CD50 and RD50 data. The chlorimuron-ethyl resistance factor values for the control percentage and fresh weight parameters were higher than 16.5 and 16.9, respectively, while imazethapyr showed resistance factors higher than 25.0 and 23.5, respectively. The resistant biotype showed different resistance levels to chlorimuron-ethyl and imazethapyr, showing cross-resistance to the sulfonylurea and imidazolinone groups. Nevertheless, this biotype was effectively controlled by fomesafen (250 g ha-1, lactofen (120 g ha-1, flumiclorac-pentyl (40 g ha-1, glufosinate-ammonium (150 g ha-1, and glyphosate (360 g ha-1.Os herbicidas constituem a principal medida de controle de plantas daninhas na cultura da soja, mas através da pressão de seleção, o uso contínuo e

  13. Comparative evaluation of Type 1 latex hypersensitivity in patients with chronic urticaria, rubber factory workers and healthy control subjects

    NARCIS (Netherlands)

    Piskin, Gamze; Akyol, Aynur; Uzar, Hatice; Tulek, Necla; Boyvat, Ayse; Gurgey, Erbak

    2003-01-01

    Latex hypersensitivity manifests itself most commonly with contact urticaria. In this study, we investigated the frequency of latex hypersensitivity as a possible aetiological factor in patients with chronic urticaria (CU) and compared latex hypersensitivity of CU patients (n = 50) with that of

  14. A Reappraisal of Online Mathematics Teaching Using LaTeX

    Directory of Open Access Journals (Sweden)

    Eamon Costello

    2009-12-01

    Full Text Available The mathematics language LaTeX is often seen outside of academic circles as a legacy technology that is awkward to use. MathML - a verbose language designed for data-exchange, and to be written and understood by machines - is sometimes by contrast seen as something that will aid online mathematics and lack of browser support for it bemoaned. However LaTeX can already do many of the things that MathML might promise. LaTeX is here proposed as a language from which small fragments, with concise syntax, can be used by people to easily create and share mathematical expressions online. The capability to embed fragments of LaTeX code in online discussions is described here and its impact on a group of educators and learners evaluated. Here LaTeX is posited as a useful tool for facilitating asynchronous, online, collaborative learning of mathematics.

  15. Thrombin like activity of Asclepias curassavica L. latex: action of cysteine proteases.

    Science.gov (United States)

    Shivaprasad, H V; Rajesh, R; Nanda, B L; Dharmappa, K K; Vishwanath, B S

    2009-05-04

    To validate the scientific basis of plant latex to stop bleeding on fresh cuts. Cysteine protease(s) from Asclepias curassavica (Asclepiadaceae) plant latex was assessed for pro-coagulant and thrombin like activities. A waxy material from the latex of Asclepias curassavica latex was removed by freezing and thawing. The resulted latex enzyme fraction was assayed for proteolytic activity using denatured casein as substrate. Its coagulant activity and thrombin like activity were determined using citrated plasma and pure fibrinogen, respectively. Inhibition studies were performed using specific protease inhibitors to know the type of protease. The latex enzyme fraction exhibited strong proteolytic activity when compared to trypsin and exerted pro-coagulant action by reducing plasma clotting time from 195 to 58 s whereas trypsin reduced clotting time marginally from 195 to 155 s. The pro-coagulant activity of this enzyme fraction was exerted by selectively hydrolyzing A alpha and B beta subunits of fibrinogen to form fibrin clot when pure fibrinogen was used as substrate as assessed by fibrinogen-agarose plate method and fibrinogen polymerization assay. Trypsin failed to induce any fibrin clot under similar conditions. The electrophoretic pattern of latex enzyme fraction-induced fibrin clot was very much similar to that of thrombin-induced fibrin clot and mimic thrombin like action. The proteolytic activity including thrombin like activity of Asclepias curassavica latex enzyme fraction was completely inhibited by iodoaceticacid (IAA). Cysteine proteases from Asclepias curassavica latex exhibited strong pro-coagulant action and were found to be specific in its action (Thrombin like). This could be the basis for the use of plant latex in pharmacological applications that justify their use as folk medicine.

  16. Cost evaluation of radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Makuuchi, K.

    2003-01-01

    Cost of radiation vulcanized NR latex was evaluated. The plant would be built in an existing dipping factory in an industrial area in a Southeast Asian country. One thousands dry tons of NR latex are vulcanized with a low energy electron accelerator. The electron accelerator is a self-shielding low energy type. The maximum accelerating voltage is 300 kV and the output power is 10 kW. The total construction cost of the plant is $400,000 including electron accelerator and other equipments. Costs of raw materials and utilities are $1.165 and $0.023 per one kg of product, respectively. The fixed costs of the plant consist of labor costs, labor overhead, maintenance, plant overhead, depreciation, and bank interest. It is $0.190/kg of product. The company overhead for operation including company management, R and D and insurance is $0.044/kg of product. Thus, the total production cost is estimated to be $1.422/kg of product. (author)

  17. INHIBITION EFFECT OF FLAVONOID EXTRACT OF Euphorbia Guyoniana ON THE CORROSION OF MILD STEEL IN H2SO4 MEDIUM

    Directory of Open Access Journals (Sweden)

    S. Chihi

    2009-08-01

    Full Text Available The influence of flavonoids extracts of three parts of Euphorbia Guyoniana towards the corrosion of type API 5L X52 steel in 15% H2SO4 has been evaluated by weight loss method and polarization technique. The results showed that extracts are a good inhibitors for API 5L X52 steel in this medium. The corrosion inhibition efficiency increases on increasing plant extracts concentration. The inhibition is attributed to the adsorption of the surface of the metal. Potentiodynamic polarization results revealed that the studied inhibitors behave as a mixed type.

  18. Estudo botânico, fitoquímico e fisico-químico de Euphorbia hirta L. (Euphorbiaceae)

    OpenAIRE

    Pinto,M.V.; Nogueira,J.C.M.; Tresvenzol,L.M.F.; Fiuza,T.S.; Paula,J.R.; Bara,M.T.F.

    2014-01-01

    Euphorbia hirta L., popularmente conhecida por erva andorinha, tem sido utilizada no tratamento de distúrbios respiratórios e como antiespasmódico. Esse trabalho foi realizado com a finalidade de determinar as características macroscópicas e microscópicas das folhas, caule e raiz dessa planta, uma vez que estas são as partes usadas popularmente. Algumas características de valor na sua diagnose foram apontadas e ilustradas por fotomicrografias. Reações de fitoquímica e a determinação do conteú...

  19. The candelabra tree (Euphorbia ingens: a source of water for black rhinoceros in Liwonde National Park, Malawi

    Directory of Open Access Journals (Sweden)

    C.O. Dudley

    1997-08-01

    Full Text Available The introduction of two rhinoceros into a 15 km2 fenced sanctuary within Liwonde National Park provided an opportunity for close observation of the animals feeding on the toxic succulent Euphorbia ingens. Feeding invariably caused the death of the plant and for plants with basal diameters between 5-17 cm, mortality ranged from 40-90 . During the severe drought of 1994 rhinoceros did not drink from the artificial waterhole from approximately 15 July to at least 23 September. As this waterhole was the only source of free water it is believed that the rhinoceros obtained their water from browsing on E. ingens.

  20. Antiproliferative and Antioxidant Activities of Two Extracts of the Plant Species Euphorbia dendroides L.

    Directory of Open Access Journals (Sweden)

    Agena Ghout

    2018-04-01

    Full Text Available Background: These days, the desire for naturally occurring antioxidants has significantly increased, especially for use in foodstuffs, cosmetics, and pharmaceutical products, to replace synthetic antioxidants that are regularly constrained due to their carcinogenicity. Methods: The study in hand aimed to appraise the antioxidant effect of two Euphorbia dendroides extracts using reducing power, anti-peroxidation, and DPPH (1,1 Diphenyl 2 Pycril Hydrazil scavenging essays, in addition to the anticancer activity against two tumor cell lines, namely C6 (rat brain tumorcells, and Hela (human uterus carcinomacell lines. Results: The results indicated that the ethyl acetate extract exhibited antiradical activity of 29.49%, higher than that of n-butanol extract (18.06% at 100 µg/mL but much lower than that of gallic acid (78.21%.The ethyl acetate extract exhibits better reducing capacity and lipid peroxidation inhibitory activity compared to n-butanol extract but less than all tested standards. Moreover, the ethyl acetate extract was found to have an antiproliferative activity of more than 5-FU (5-fluoro-Uracil against C6 cells at 250 µg/mL with IC50 and IC75 of 113.97, 119.49 µg/mL, respectively, and good cytotoxic activity against the Hela cell lines at the same concentration. The HPLC-TOF-MS (high performance liquid chromatography-Time-of-flight-Mass Spectrometry analyses exposed the presence of various compounds, among which Gallic and Chlorogenic acids functioned as major compounds. Conclusions: The two extracts exhibited moderate anticancer abilities and behaved somewhat as average antioxidant agents. Based on the total phenolics and flavonoids contents, as well as HPLC results, it could be concluded that antiproliferative and antioxidant activities depend upon the content of different phenolics and flavonoids.

  1. Morphological, physiological and biochemical responses of biofuel plant Euphorbia lathyris to salt stress

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jie; Cao, Yan; Yang, Ziyi; Lu, Changmei [Jiangsu Key Laboratory for Biodiversity and Biotechnology, College of Life Science, Nanjing Normal Univ., Nanjing (China)], E-mail: 08134@njnu.edu.cn); Zhang, Weiming; Sun, Lijun [Nanjing Inst. for the Comprehensive Utilization of Wild plants, Nanjing (China)

    2013-05-15

    Saline lands are characterized by salinity and nutrient deficiency and there is an ever increasing need for economical, adaptable plant species to rejuvenate these lands. In this study, we determined the suitability and tolerance of Euphorbia lathyris L. (Caper spurge), a well-known biofuel plant, as a sustainable candidate to colonize saline lands. We investigated the germination rate, seedling growth, solute change and anti-oxidative enzyme activities etc. under salt stress conditions. Our results showed that Caper spurge seeds prefer to germinate under nonsaline environments and high salt stress induced temporary dormancy during germination, but did not completely hamper the viability of the seeds. The seedling biomass increased without any visible distress symptoms in the presence of NaCl not over 171 mM. Further increase in NaCl concentration had a negative impact on the seedling growth. These demonstrate that Caper spurge seedlings have the potential to grow in saline lands. The salinity tolerance of Caper spurge seedlings was closely associated with the regional distribution of Na{sup + }in roots, stable absorption of Ca{sup 2{sup +,}} K{sup + }and Mg{sup 2{sup +,}} accumulation of organic solutes, and increased activity of superoxide dismutase (SOD) and catalase (CAT) enzymes. However, excessive accumulation of Na{sup +,} sharp increase of superoxide (O{sub 2}), H{sub 2}O{sub 2}, malonaldehyde (MDA) and cell membrane leakage, reduction of osmoprotectants, and decreased activities of CAT and ascorbate peroxidase (APX) etc. under high salinity might be the reasons for the restrained seedling growth.

  2. Overexpression of the AtSHI gene in poinsettia, Euphorbia pulcherrima, results in compact plants.

    Directory of Open Access Journals (Sweden)

    M Ashraful Islam

    Full Text Available Euphorbia pulcherrima, poinsettia, is a non-food and non-feed vegetatively propagated ornamental plant. Appropriate plant height is one of the most important traits in poinsettia production and is commonly achieved by application of chemical growth retardants. To produce compact poinsettia plants with desirable height and reduce the utilization of growth retardants, the Arabidopsis SHORT INTERNODE (AtSHI gene controlled by the cauliflower mosaic virus 35S promoter was introduced into poinsettia by Agrobacterium-mediated transformation. Three independent transgenic lines were produced and stable integration of transgene was verified by PCR and Southern blot analysis. Reduced plant height (21-52% and internode lengths (31-49% were obtained in the transgenic lines compared to control plants. This correlates positively with the AtSHI transcript levels, with the highest levels in the most dwarfed transgenic line (TL1. The indole-3-acetic acid (IAA content appeared lower (11-31% reduction in the transgenic lines compared to the wild type (WT controls, with the lowest level (31% reduction in TL1. Total internode numbers, bract numbers and bract area were significantly reduced in all transgenic lines in comparison with the WT controls. Only TL1 showed significantly lower plant diameter, total leaf area and total dry weight, whereas none of the AtSHI expressing lines showed altered timing of flower initiation, cyathia abscission or bract necrosis. This study demonstrated that introduction of the AtSHI gene into poinsettia by genetic engineering can be an effective approach in controlling plant height without negatively affecting flowering time. This can help to reduce or avoid the use of toxic growth retardants of environmental and human health concern. This is the first report that AtSHI gene was overexpressed in poinsettia and transgenic poinsettia plants with compact growth were produced.

  3. Synthesis and characterization of fluorinated polyacrylate latex emulsified with novel surfactants.

    Science.gov (United States)

    Zhang, Cuifeng; Xu, Tingting; Bao, Zhongbin; Chen, Lijun

    2017-01-01

    The fluorinated polyacrylate latex were successfully prepared with semi- continuous seeded emulsion polymerization of butyl acrylate (BA), methyl methacrylate (MMA) and hexafluorobutyl methacrylate (HFMA) which was initiated with potassium persulfate (KPS) initiator and emulsified with the novel mixed surfactants of sodium lauryl glutamate (SLG) and alkylphenol ethoxylates (OP-10). The structure of the resultant latex was confirmed by Fourier transform infrared spectroscopy (FTIR). The particle size of the latex was measured by Zetatrac dynamic light scattering detector. The film of latex was tested by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and contact angle (CA). The optimum conditions of preparing the novel fluorinated polyacrylate latex are optimized and the results are as follows: the amount of emulsifiers is 4.0%; mass ratio of SLG to OP-10 is 1:1, the amount of the initiator is 0.6%. The mass ratio of MMA to BA is 1:1 and the amount of HFMA is 7.0%. In this case, the conversion is high and the polymerization stability is good. In addition, the water resistance and thermal properties of the latex films were improved significantly in comparison with the film of the latex prepared without the fluorinated monomer.

  4. Plant latex: a promising antifungal agent for post harvest disease control.

    Science.gov (United States)

    Sibi, G; Wadhavan, Rashmi; Singh, Sneha; Shukla, Abhilasha; Dhananjaya, K; Ravikumar, K R; Mallesha, H

    2013-12-01

    Bioactive compounds from plant latex are potential source of antifungic against post harvest pathogens. Latex from a total of seven plant species was investigated for its phytochemical and antifungal properties. Six fungi namely Aspergillus fumigatus, A. niger, A. terreus, F. solani, P. digitatum and R. arrhizus were isolated from infected fruits and vegetables and tested against various solvent extracts of latex. Analysis of latex extracts with phytochemical tests showed the presence of alkaloids, flavonoids, glycosides, phenols, saponins, steroids, tannins and terpenoids. Antifungal assay revealed the potential inhibitory activity of petroleum ether extracts against the postharvest fungal isolates. Various degree of sensitivity was observed irrespective of plant species studied with A. terreus and P. digitatum as the most susceptible ones. F. solani and A. fumigatus were moderately sensitive to the latex extracts tested. Among the plants, latex of Thevetia peruviana (75.2%) and Artocarpus heterophyllus (64.8%) were having potential antifungal activity against the isolates followed by Manilkara zapota (51.1%). In conclusion, use of plant latex makes interest to control postharvest fungal diseases and is fitting well with the concept of safety for human health and environment.

  5. Antioxidant and sensitizer effect on the stability of natural rubber latex vulcanized by gamma rays

    International Nuclear Information System (INIS)

    Canavel, V.

    1993-01-01

    The natural rubber latex was vulcanized by gamma rays and electrons beam, in the presence and absence of sensitizer at room temperature. The sensitizers were the following; n-butyl acrylate (n-BA) / t-butyl hydroperoxide (t-B H) / KOH, C Cl 4 / potassium laurate and n-BA / KOH. The studied antioxidants, Irganox 1520, Vulcanox SP and Vulcanox BKF, were added to the latex after irradiation. Among the studied antioxidants in function of tensile strength (TS) after the aging of rubber plates, the Irganox was the best efficient on the gamma vulcanization in the presence of n-BA/t-B H/KOH, because only 0,20 p hr is enough to obtain the greatest increase of TS, that was 34%, 12 MPa to 16 MPa. The formulating method of latex with the sensitizer constituted the 3,0 p hr of n-BA/ 0,1 p hr of t-B H and 0,2 p hr of KOH, was evaluated respecting the TS of rubber plates. The electrons beam vulcanization produces the greatest reversible perturbance in the colloidal stability of latex after irradiation caused by radiolytic species absorption that promotes the increase of particle size. The antioxidant also contributes to reversible destabilization of gamma irradiated latex, because it is also adsorbed by particles surface. The relation between the latex viscosity and the TS of respective rubber plates is reverse, showing the latex stability affects the quality of rubber goods. (author)

  6. Aggregation and charging of sulfate and amidine latex particles in the presence of oxyanions.

    Science.gov (United States)

    Sugimoto, Takuya; Cao, Tianchi; Szilagyi, Istvan; Borkovec, Michal; Trefalt, Gregor

    2018-08-15

    Electrophoretic mobility and time resolved light scattering are used to measure the effect on charging and aggregation of amidine and sulfate latex particles of different oxyanions namely, phosphate, arsenate, sulfate, and selenate. In the case of negatively charged sulfate latex particles oxyanions represent the coions, while they represent counterions in the case of the positively charged amidine latex. Repulsive interaction between the sulfate latex surface and the coions results in weak ion specific effects on the charging and aggregation. On the other hand the interaction of oxyanions with the amidine latex surface is highly specific. The monovalent dihydrogen phosphate ion strongly adsorbs to the positively charged surface and reverses the charge of the particle. This charge reversal leads also to the restabilization of the amidine latex suspension at the intermediate phosphate concentrations. In the case of dihydrogen arsenate the adsorption to amidine latex surface is weaker and no charge reversal and restabilization occurs. Similar differences are seen between the sulfate and selenate analogues, where selenate adsorbs more strongly to the surface as compared to the sulfate ion and invokes charge reversal. The present results indicate that ion specificity is much more pronounced in the case of counterions. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Preparation of irradiated natural rubber latex-styrene copolymer for electrical gloves

    International Nuclear Information System (INIS)

    Made Sumarti Kardha

    2010-01-01

    Research on irradiated natural rubber latex-styrene copolymer to prepare electrical glove have been done. Vulcanization of natural rubber latex (NRL) was done by mixing 2 phr (per hundred of rubber) of normal butyl acrylate (n-BA) emulsion then irradiated with ã-ray "6"0Co at the dose of 30 kGy producing irradiated natural rubber latex (INRL). Natural rubber latex-styrene copolymers (SC) were prepared by mixing NRL and styrene monomer at styrene concentrations of 50 phr, 75 phr, 100 phr, 500 phr and irradiated at the doses of 15 kGy, 30 kGy and 45 kGy, then characterized their latex and film properties to obtain optimum SC of SC50. This optimum SC, SC50 then mixed with IRNL at the weight ratio of 0/100, 30/70, 50/50, 70/30 and 100/0, to produce irradiated natural rubber latex-styrene copolymer. The properties of copolymer rubber films made by dipping process i.e., % conversion, total solid content, latex viscosity, tensile strength, modulus 300 %, elongation at break, electrical resistance and dielectric constant were then characterized. Characterization result showed that (INRL-SC50) with 50/50 ratio irradiated at the dose of 30 kGy, have % conversion of 80.93 %, electrical resistivity of 1.73 x 10"1"4 Ohm cm and dielectric constant of 2.76 which fulfill the requirement as material for electrical gloves. (author)

  8. Solid state NMR and LVSEM studies on the hardening of latex modified tile mortar systems

    International Nuclear Information System (INIS)

    Rottstegge, J.; Arnold, M.; Herschke, L.; Glasser, G.; Wilhelm, M.; Spiess, H.W.; Hergeth, W.D.

    2005-01-01

    Construction mortars contain a broad variety of both inorganic and organic additives beside the cement powder. Here we present a study of tile mortar systems based on portland cement, quartz, methyl cellulose and different latex additives. As known, the methyl cellulose stabilizes the freshly prepared cement paste, the latex additive enhances final hydrophobicity, flexibility and adhesion. Measurements were performed by solid state nuclear magnetic resonance (NMR) and low voltage scanning electron microscopy (LVSEM) to probe the influence of the latex additives on the hydration, hardening and the final tile mortar properties. While solid state NMR enables monitoring of the bulk composition, scanning electron microscopy affords visualization of particles and textures with respect to their shape and the distribution of the different phases. Within the alkaline cement paste, the poly(vinyl acetate) (VAc)-based latex dispersions stabilized by poly(vinyl alcohol) (PVA) were found to be relatively stable against hydrolysis. The influence of the combined organic additives methyl cellulose, poly(vinyl alcohol) and latexes stabilized by poly(vinyl alcohol) on the final silicate structure of the cement hydration products is small. But even small amounts of additives result in an increased ratio of ettringite to monosulfate within the final hydrated tile mortar as monitored by 27 Al NMR. The latex was found to be adsorbed to the inorganic surfaces, acting as glue to the inorganic components. For similar latex water interfaces built up by poly(vinyl alcohol), a variation in the latex polymer composition results in modified organic textures. In addition to the networks of the inorganic cement and of the latex, there is a weak network build up by thin polymer fibers, most probably originating from poly(vinyl alcohol). Besides the weak network, polymer fibers form well-ordered textures covering inorganic crystals such as portlandite

  9. Comparing the level of dexterity offered by latex and nitrile SafeSkin gloves.

    Science.gov (United States)

    Sawyer, Jo; Bennett, Allan

    2006-04-01

    An increase in the occurrence of latex allergy has been concurrent with the increasing use of latex gloves by laboratory and healthcare workers. In recent years nitrile gloves have been used to replace latex gloves to prevent latex allergy. Nitrile gloves offer a comparable level of protection against chemical and biological agents and are more puncture resistant. However, if manual dexterity is compromised by nitrile gloves to a greater degree than latex then this may increase the risk of sharps injuries. The Purdue pegboard test, which measures both gross and fine finger dexterity, was used to test the dexterity levels of two glove types used at HPA CEPR; Kimberly-Clark SafeSkin nitrile and latex laboratory gloves. There was a statistically significant 8.6% increase in fine finger dexterity provided by latex compared with nitrile SafeSkin laboratory gloves but no difference in gross dexterity between the glove types. There was no significant relationship between glove dexterity and age or gender. The selection of glove size was influenced by the digit length of participants. Moreover, those with longer, thinner fingers appeared to have an advantage when using nitrile SafeSkin gloves. The level of dexterity provided by latex and nitrile SafeSkin gloves for tasks on a gross dexterity level are comparable and health workers will benefit from the non-allergenic properties of nitrile. For tasks requiring fine finger dexterity nitrile SafeSkin gloves may impede dexterity. Despite this, the degree of restriction appears to have a negligible impact on safety in this study when compared with the risk of latex sensitization and subsequent allergy. In addition to glove material, working practices must also take into account glove size, fit, grip and thickness, as these factors can all influence dexterity.

  10. Impact of black rhinoceros (Diceros bicornis minor) on a local population of Euphorbia bothae in the Great Fish River Reserve, South Africa

    NARCIS (Netherlands)

    Luske, B.L.; Mertens, T.; Lent, P.C.; Boer, de W.F.; Prins, H.H.T.

    2009-01-01

    In the Great Fish River Reserve, South Africa, black rhinoceros (Diceros bicornis minor) feed extensively on a local population of Euphorbia bothae. Maintaining the endangered black rhinoceros and the protected E. bothae population are both conservation priorities of the reserve. Therefore, the

  11. Chemical Composition and Mosquitocidal activity of n-Hexane and Methanol Extracts from Euphorbia anacampseros var. tmolea, an endemic species of Turkey, against Aedes aegypti

    Science.gov (United States)

    New and safe mosquito control agents are necessary due to increasing resistance to synthetic insecticides and environmental change. The mosquito larvicidal and adulticidal activity and chemical composition of Euphorbia anacampseros var. tmolea extracts are investigated in this article for the first ...

  12. Latex-modified grouts for in-situ stabilization of buried transuranic/mixed waste

    International Nuclear Information System (INIS)

    Allan, M.L.

    1996-06-01

    The Department of Applied Science at Brookhaven national Laboratory was requested to investigate latex-modified grouts for in-situ stabilization of buried TRU/mixed waste for INEL. The waste exists in shallow trenches that were backfilled with soil. The objective was to formulate latex-modified grouts for use with the jet grouting technique to enable in-situ stabilization of buried waste. The stabilized waste was either to be left in place or retrieved for further processing. Grouting prior to retrieval reduces the potential release of contaminants. Rheological properties of latex-modified grouts were investigated and compared with those of conventional neat cement grouts used for jet grouting

  13. Glove powder's carrying capacity for latex protein: analysis using the ASTM ELISA test.

    Science.gov (United States)

    Beezhold, D; Horton, K; Hickey, V; Daddona, J; Kostyal, D

    2003-01-01

    Glove donning powders carry latex proteins and disperse them into the workplace environment. We have used the ASTM D6499 ELISA to quantify the amount of latex antigen bound to and carried by glove powders. We could differentiate between a small amount of protein actually bound to the powders and a larger amount carried by the powder. Enhanced binding of a major allergen, Hev b 5, to the starch powders was demonstrated by Western blot. The D6499 ELISA is able to measure total latex antigen, soluble and powder bound, simultaneously without the need to centrifuge the samples.

  14. Binding kinetics of magnetic nanoparticles on latex beads and yeast cells studied by magnetorelaxometry

    International Nuclear Information System (INIS)

    Eberbeck, Dietmar; Bergemann, Christian; Hartwig, Stefan; Steinhoff, Uwe; Trahms, Lutz

    2005-01-01

    The ion exchange mediated binding of magnetic nanoparticles (MNP) to modified latex spheres and yeast cells was quantified using magnetorelaxometry. By fitting subsequently recorded relaxation curves, the kinetics of the binding reactions was extracted. The signal of MNP with weak ion exchanger groups bound to latex and yeast cells scales linearly with the concentration of latex beads or yeast cells whereas that of MNP with strong ion exchanger groups is proportional to the square root of concentration. The binding of the latter leads to a much stronger aggregation of yeast cells than the former MNP

  15. Study on irradiation condition in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Zhu Nankang; Wang Chunlei; Makuuchi, K.; Yoshii, F.

    1996-01-01

    The effect of gamma rays irradiation dose rates on RVNRL preparation was studied using Malaysian latex added with O.2 phr of KOH and 5 phr n-BA. The results showed, to ensure the tensile strength of the latex film meet the requirement, when applying vulcanisation doses, Dv of 20 kGy 20 and 15 kGy, irradiation dose rates should not be greater than 0. 49 kGy/hr and 1. 6 kGy/hr respectively. Its was found that within the storage time of 20 days there was no change in the physical properties of the latex films

  16. Optical response of a flat metallic surface coated with a monolayer array of latex spheres

    International Nuclear Information System (INIS)

    Shi Lei; Liu Xiaohan; Yin Haiwei; Zi Jian

    2010-01-01

    We report on the fabrication, characterization and simulation of a structure consisting of a flat metallic surface coated with a monolayer array of latex spheres. This structure shows interesting optical response: over flat metallic surfaces a series of reflection minima appear in reflection spectra. Numerical simulations revealed that the structure can support two types of surface modes: surface plasmon-polaritons bound at the metallic surface and guided modes confined to the array of latex spheres, or their hybrids. Both experimental and theoretical results indicated that these surface modes show well-defined band structures due to the introduced periodicity by the monolayer array of latex spheres.

  17. In vitro growth inhibition and cytotoxicity of Euphorbia caducifolia against four human cancer cell lines and its phytochemical characterisation.

    Science.gov (United States)

    Bano, Shaista; Siddiqui, Bina Shaheen; Farooq, Ahsana Dar; Begum, Sabira; Siddiqui, Faheema; Kashif, Muhammad; Azhar, Mudassar

    2017-12-01

    Several Euphorbia species have been used in folklore as cancer remedies, however, scientific studies on the cytotoxicity (in vitro studies) of Euphorbia caducifolia are lacking. In present study, anticancer potential of E. caducifolia aerial parts ethanol extract and its fractions were evaluated against human lung (NCI-H460), breast (MCF-7), prostate (PC-3) and cervical (HeLa) cancer cell lines, using sulphorhodamine-B in vitro cytotoxicity (in vitro studies) assay. The ethanol extract demonstrated growth inhibitory effect against all aforementioned cancer cell lines with IC 50 , 19-135 μg/mL and LC 50 , ~220 μg/mL, and its petroleum ether fraction obtained on bioactivity guided fraction showed highest activity with IC 50 , 28-70 μg/mL and LC 50 , 71 μg/mL against NCI-H460 and MCF-7 cell lines. Its phytochemicals were analysed by gas chromatography-mass spectrometry (GC-MS). The present study provides scientific justification for its traditional use against cancer.

  18. Validation for radiation sterilization of surgical latex glove

    International Nuclear Information System (INIS)

    Liu Degui

    2002-01-01

    Objective: To determine the optimal radiation mode for sterilization of surgical latex gloves. Methods: The dose distribution in the product loads inside radiation container was measured in different radiation mode. Results: Data of dose distribution in the product load in different radiation mode were obtained. Conclusion: At pre-set height of source working position and within pre-determined dwelling time of each irradiation container staying at the irradiation position, the delivered dose can meet the customers requirement by the radiation mode that, in the half cycle of radiation process, turns the horizontal middle layers of the product to the upper or lower layers, and the upper and lower layers to the middle layers

  19. A New Prenylated Xanthone from Latex of Garcinia cowa Roxb.

    Directory of Open Access Journals (Sweden)

    Zhi Na

    2013-05-01

    Full Text Available A new prenylated xanthone, 1,6-dihydroxy-3,7-dimethoxy-2-(3,7-dimethyloct-2,6-dienyl xanthone (3-O-methylcowaxanthone (1, together with four known xanthones, cowaxanthone (2, 7-O-methylgarcinone (3, α-mangostin (4 and γ-mangostin (5 were isolated from the latex of Garcinia cowa. The structure of compound 1 was elucidated on the basis of spectroscopic data interpretation, including 1D and 2D NMR and HREIMS. The cytotoxic activitiy of 1 against five human cancer cell lines, HL-60, SMMC-7721, A-549, MCF-7 and SW480, was evaluated, but it was inactive (IC 50>40μM.

  20. Purification of papain from fresh latex of Carica papaya

    Directory of Open Access Journals (Sweden)

    Rubens Monti

    2000-01-01

    Full Text Available In the present study we wish to report a method of crystallizing papain from fresh papaya latex which gave higher yields than previously reported. This method does not involve the use of sulphydryl reagents. The papain thus obtained is practically pure and shows a single band when submitted to electrophoresis on polyacrylamide gel, and is identical to the papain obtained by other methods. In routine enzymatic assays, specific activity was measured using Z-gly-pNP and BAEE as substrates. Papain crystallized by this method, without the use of high concentrations of salts or thiol-containing substances such as cysteine and dithiothreitol, is obtained in the form of a complex with natural inhibitors existent in latex which can be removed by dialysis.No presente trabalho apresenta-se um método de cristalização da papaína oriunda do látex fresco de mamão, o qual apresenta uma alta produtividade em relação aos métodos previamente descritos. A metodologia aqui descrita não envolve o uso de reagentes sulfidrílicos, a papaína foi obtida de forma praticamente pura, apresentando uma simples banda quando submetida a eletroforese, e com propriedades idênticas àquelas obtidas por outros métodos. A atividade específica foi determinada utilizando Z-gly-pNP e BAEE como substrato. A papaína obtida por essa metodologia, sem uso de substâncias tais como cisteína e ditiotreitol, apresenta-se na forma de um complexo com inibidores naturais, os quais podem ser removidos por diálise.

  1. Maillard Reaction in Natural Rubber Latex: Characterization and Physical Properties of Solid Natural Rubber

    Directory of Open Access Journals (Sweden)

    S. Montha

    2016-01-01

    Full Text Available Maillard reaction in Natural Rubber (NR latex was investigated by treating fresh NR latex with glutaraldehyde (C5H8O2 in amounts of 0, 50, 100, and 200 mmol/kg of latex. Protein cross-linking in fresh NR latex and solid NR was confirmed by using sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE and attenuated total reflection infrared (ATR-IR spectroscopy, respectively. It was found that degree of protein cross-linking in NR increased with increasing C5H8O2 concentration. Physical properties of untreated and treated NR substances in terms of gel content, initial Wallace plasticity (P0, plasticity retention index (PRI, Mooney viscosity, and tensile strength were carefully explored. Results clearly showed that the Maillard cross-linking of proteins had remarkable effect on bulk NR properties, that is, solvent resistance, hardness, resistance to oxidation, rheological behavior, and resistance to stretching out.

  2. Evaluation of apparent viscosity of Para rubber latex by diffuse reflection near-infrared spectroscopy.

    Science.gov (United States)

    Sirisomboon, Panmanas; Chowbankrang, Rawiphan; Williams, Phil

    2012-05-01

    Near-infrared spectroscopy in diffuse reflection mode was used to evaluate the apparent viscosity of Para rubber field latex and concentrated latex over the wavelength range of 1100 to 2500 nm, using partial least square regression (PLSR). The model with ten principal components (PCs) developed using the raw spectra accurately predicted the apparent viscosity with correlation coefficient (r), standard error of prediction (SEP), and bias of 0.974, 8.6 cP, and -0.4 cP, respectively. The ratio of the SEP to the standard deviation (RPD) and the ratio of the SEP to the range (RER) for the prediction were 4.4 and 16.7, respectively. Therefore, the model can be used for measurement of the apparent viscosity of field latex and concentrated latex in quality assurance and process control in the factory.

  3. Proceedings of the international symposium on radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Machi, Sueo

    1990-01-01

    The First International Symposium on Radiation Vulcanization of Natural Rubber Latex (RVNRL) was held from 26 to 28 July 1989 at Tokyo and Takasaki. In these proceedings, thirty six papers presented at the Symposium are compiled. Main topics are commercial application of RVNRL, characterization of NR latex and vulcanization, properties of radiation vulcanized NR latex, development of sensitizers, mechanism of RVNRL, RVNRL with electron beams, and new Co-60 irradiator for RVNRL. Absence of nitrosamines and low cytotoxicity of radiation vulcanized NR latex are recognized as the remarkable advantages of RVNRL. The radiation vulcanization process for the production of protective rubber gloves for radioactive contamination was presented as the first commercial success in RVNRL. It was reported that various kinds of rubber articles for medical uses have being developed in West Germany. A sensitizer system consisting of n-butyl acrylate and t-butyl hydroperoxide was found to reduce the vulcanization dose to 8 kGy. (author)

  4. Latex glove sensitivity amongst diagnostic imaging healthcare personnel: a self-reporting investigation

    International Nuclear Information System (INIS)

    Healy, Jan; Brennan, Patrick C.; Bowden, Julie Anne

    2003-01-01

    The use of latex gloves has risen dramatically among healthcare workers resulting in an increase in the number of workers experiencing reactions to gloves. Little evidence of reactions among Irish healthcare workers is available. The current, self-reporting study investigated the prevalence to latex gloves amongst four professional groups within three Diagnostic Imaging Departments. Prevalence is similar to that demonstrated elsewhere with 18.3% of individuals expressing latex associated symptoms. Symptoms included itching and redness of hands, dry cracked skin, soreness of eyes and upper respiratory tract complaints. These results indicate that latex hypersensitivity is a real problem amongst Irish healthcare workers. This preliminary work provides the basis of a much larger controlled study currently being planned

  5. Effect of gamma radiation dose and sensitizer on the physical properties of irradiated natural rubber latex

    International Nuclear Information System (INIS)

    Komgrit, R.; Thawat, C.; B, Tripob; Wirach, T.

    2009-07-01

    Full text: The vulcanization of natural rubber latex can be induced by gamma radiation, which enhances cross-linking within the rubber matrix. The purpose of this research is to investigate the effect of gamma radiation dose and sensitizers on the physical properties of irradiated natural rubber. Three sensitizers n-butyl acrylate (n-B A), tetrachloroethylene (C 2 Cl 4 ) and trichloromethane (CHCl 3 ) were mixed with natural rubber latex before irradiation with gamma ray dose varied from 14 to 22 kGy. Results showed that the mixture of three sensitizers with specific ratios effectively induced the cross-linking of natural rubber latex. The cross-linking ratio and improved physical properties increased with increasing gamma dose. Therefore, the mixture ratios of n-B A, C 2 Cl 4 and CHCl 3 have shown to be a critical parameter in the vulcanization of natural rubber latex by gamma radiation

  6. A LaTeX graphics routine for drawing Feynman diagrams

    International Nuclear Information System (INIS)

    Levine, M.J.S.

    1990-01-01

    FEYNMAN is a LaTeX macropackage which allows the user to construct a versatile range of Feynman diagrams within the text of a document. Diagrams of publication quality may be drawn with relative ease and rapidity. (orig.)

  7. Polylactide/Montmorillonite Hybrid Latex as a Barrier Coating for Paper Applications

    Directory of Open Access Journals (Sweden)

    Davide Bandera

    2016-03-01

    Full Text Available We developed a paper coating for the potential application in food packaging based on polylactide and montmorillonite. It is applied to the paper in the form of a stable, water-based latex with a solid content of 25–28 wt %. The latex is prepared from a commercially available polylactide, surfactants, montmorillonite, a plasticizer, chloroform (to be removed later and water by an emulsion/solvent evaporation procedure. This coating formulation is applied to the paper substrate by bar-coating, followed by hot-pressing at 150 °C. The coated papers achieved up to an 85% improvement in water vapor transmission rates when compared to the pristine papers. The coating latex is prepared from inexpensive materials and can be used for a solvent-free coating process. In addition, the ingredients of the latex are non-toxic; thus, the coated papers can be safely used for food packaging.

  8. Formation of Defect-Free Latex Films on Porous Fiber Supports

    KAUST Repository

    Lively, Ryan P.; Mysona, Joshua A.; Chance, Ronald R.; Koros, William J.

    2011-01-01

    a defect-free lumen-side barrier layer can be created. Film experiments examined the effect of drying rate, latex age, substrate porosity (porous vs nonporous), and substrate hydrophobicity/ hydrophilicity. Film studies show that in ideal conditions

  9. Radiation vulcanization of natural rubber latex (NRL) using low energy electron beam accelerator

    International Nuclear Information System (INIS)

    Feroza Akhtar; Keizo Makuuchi; Fumio Yoshii

    1996-01-01

    The electron beam induced vulcanization of natural rubber latex has been studied using low energy Electron Beam (EB) accelerators of 300, 250 and 175 keV ne latex was irradiated in a special type stainless steel reaction reactor with a stirrer at the bottom of the reactor. From the results it was found that 300 and 250 keV accelerators could effectively vulcanize NRL. But accelerator of 175 keV is too low energy to vulcanize the latex. At the same time a drum type irradiator where thin layer of NRL was irradiated by accelerator, was used for vulcanization of NRL. This type of irradiator also showed good physical properties of vulcanized latex. The effects of beam current and stirrer speed on vulcanization were studied

  10. Effect of heterogeneous distribution of crosslink density on physical properties of radiation vulcanized NR (Natural Rubber) latex film

    International Nuclear Information System (INIS)

    Keizo Makuuchi; Fumio Yoshii; Miura, H.; Murakami, K.

    1996-01-01

    Thus a study has been carried out to investigate the effect of particle to particle variation in crosslink density on physical properties of radiation vulcanized NR latex film. NR latex was irradiated in small bottle by γ rays without vulcanization accelerator to provide latex rubber particles having homogeneous distribution of crosslink density. The doses were 30, 50, 100, 250, 300, 400, 500 and 600 kGy. Weight swelling ratio, gel fraction, tensile strength and elongation at break of the latex film from the mixed latex were measured. The vulcanization dose of this latex was 250 kGy. Then the two different latexes were mixed in a such way to adjust the average dose of 250 kGy to prepare a latex consisting of rubber particles having heterogeneous distribution of crosslink density. Tensile strength of the latex film was depressed by mixing. The reduction increased with increasing the decrease of gel fraction by mixing. However the reduction was not serious when the dose difference of two latexes was less than 200 kGy

  11. Prevalence of Allergy to Natural Rubber Latex and Potential Cross Reacting Food in Operation Room Staff in Shiraz Hospitals -2006

    Directory of Open Access Journals (Sweden)

    H Nabavizade

    2007-07-01

    Full Text Available Introduction & Objective: Allergic reactions to natural rubber latex have increased during past 10 years especially among health care workers and patients with high exposure to latex allergens. Allergic reaction to latex is related to many diseases like occupational asthma. This study was performed to determine the prevalence of allergy to natural rubber latex and potential cross reacting food in operation room staff in Shiraz hospitals. Materials & Methods: In this cross-sectional descriptive study five hundred eighty operation room staff of ten private and state hospitals in Shiraz completed latex allergy questionnaire. They were questioned about personal history and previous history of latex sensitivity, symptoms of latex reactivity and about other allergies particularly to foods that may cross react with latex. Informed consent was obtained and skin prick testing was performed with natural rubber latex. Skin prick tests were done with three potentially cross reacting food (banana, Kiwi, and potato. The obtained data were analyzed with SPSS software and Chi-square test. Results: Among the 580 operation room workers 104 (17.9 % of participants were positive to latex skin test. We found a significant association between positive skin test to latex in operation room staff and atopy, urticaria and food allergy. Positive skin test to latex related to positive kiwi skin test (p<0.05. The prevalence did not vary by sex, age, education, surgical and non surgical glove users, history of contact dermatitis or smoking status. Conclusion: Latex allergy has a high prevalence in personnel of operation room. Evaluation of present symptom and prediction of future disease necessitate screening test in individuals at risk.

  12. Latex allergy and occupational asthma in health care workers: adverse outcomes.

    OpenAIRE

    Amr, Sania; Bollinger, Mary E.

    2004-01-01

    The prevalence of natural rubber latex (NRL) allergy has been estimated to be 5-18% in health care workers, and latex exposure has been one of the leading causes of occupational asthma in the last several years. We present the cases of two nurses who developed sensitivity to NRL, both with dermatologic symptoms and respiratory symptoms that included asthma. They were referred to the University of Maryland for evaluation of their allergies, then for occupational and environmental consults. The...

  13. Preparation of composites of national rubber latex (NRL) - portland cement mould. Vol. 3

    International Nuclear Information System (INIS)

    Dessouki, A.M.; Taher, N.H.; El-Nahas, H.H.

    1996-01-01

    The aim of this study is to prepare some polymeric mould using national rubber latex (NRL) - portland cement composites based on a delayed- action mechanism. Factors affecting the preparation process such as concentration, mixing percentage, additives and their effect on what is regarded as a delayed action coacervant combination was studied. Composites of national latex (NRL) - portland cement would were prepared as two separate parts. The stabilized natural rubber latex (NRL) 100 parts with hydroxy ethyl cellulose (HEC) 2 parts as stabilizer and a delayed - action coacervant (sodium meta silicate as a delaying agent) 5 parts on one hand and the dry blend of cement 65 parts soluble in 65 parts of water as a paste on the other hand were mixed thoroughly on site. (HEC) was added to the rubber latex to prevent the coagulation of the rubber latex with the electrolyte (sodium meta silicate) present in the rubber mixture. Two kinds of stabilization occurred in the rubber part, namely steric stabilization and the stabilization against electrolyte. The effect of delayed - action coacervant (sodium meta silicate) on the initial setting time of rubber - cement mould showed that the molding process did not occur at sodium meta silicate concentration less than 2.66 parts per 100 parts of rubber latex (phr), and the optimum concentration used was 5% parts of rubber latex. It was observed that addition of a delaying agent (Sodium meta silicate) to the rubber part enhanced the delaying mechanism in the time needed for the molding process, while the addition of the delaying agent to the cement part did not have any effect on retardation of the molding process. Chemical coacervants function mainly by reducing the ζ potential which is associated with the electrical double layer surrounding the latex particle. This reduction may brought about in at least three distinct ways which take place in the system studied. 5 figs., 3 tabs

  14. Preparation of composites of national rubber latex (NRL) - portland cement mould. Vol. 3

    Energy Technology Data Exchange (ETDEWEB)

    Dessouki, A M; Taher, N H; El-Nahas, H H [National Center for Radiation Research and Technology, Atomic Energy Athority, Cairo (Egypt)

    1996-03-01

    The aim of this study is to prepare some polymeric mould using national rubber latex (NRL) - portland cement composites based on a delayed- action mechanism. Factors affecting the preparation process such as concentration, mixing percentage, additives and their effect on what is regarded as a delayed action coacervant combination was studied. Composites of national latex (NRL) - portland cement would were prepared as two separate parts. The stabilized natural rubber latex (NRL) 100 parts with hydroxy ethyl cellulose (HEC) 2 parts as stabilizer and a delayed - action coacervant (sodium meta silicate as a delaying agent) 5 parts on one hand and the dry blend of cement 65 parts soluble in 65 parts of water as a paste on the other hand were mixed thoroughly on site. (HEC) was added to the rubber latex to prevent the coagulation of the rubber latex with the electrolyte (sodium meta silicate) present in the rubber mixture. Two kinds of stabilization occurred in the rubber part, namely steric stabilization and the stabilization against electrolyte. The effect of delayed - action coacervant (sodium meta silicate) on the initial setting time of rubber - cement mould showed that the molding process did not occur at sodium meta silicate concentration less than 2.66 parts per 100 parts of rubber latex (phr), and the optimum concentration used was 5% parts of rubber latex. It was observed that addition of a delaying agent (Sodium meta silicate) to the rubber part enhanced the delaying mechanism in the time needed for the molding process, while the addition of the delaying agent to the cement part did not have any effect on retardation of the molding process. Chemical coacervants function mainly by reducing the {zeta} potential which is associated with the electrical double layer surrounding the latex particle. This reduction may brought about in at least three distinct ways which take place in the system studied. 5 figs., 3 tabs.

  15. Test trial radiation vulcanization of natural rubber latex in Jakarta Indonesia

    International Nuclear Information System (INIS)

    Devendra, R.; Kulatunge, S.S.; Chandralal, H.N.K.K.; Kalyani, N.M.V.; Seneviratne, J.; Wellage, S.

    1994-01-01

    Radiation vulcanization of natural rubber latex (RVNRL) can be used to make large quantities of specially stabilized latex. It is possible to obtain RVNRL films of tensile strength over 25 MPa. The films could be either coagulant dipped or cast. It is very important to determine the correct radiation dose which gives the maximum tensile strength. Cross linking density or prevulcanized relax modulus (PRM) at 100% is a reliable property to control the prevulcanization

  16. Soybean oil in water-borne coatings and latex film formation study by AC impedance

    Science.gov (United States)

    Jiratumnukul, Nantana

    Conventional coalescing agents such as butyl cellosolve, butyl carbitol, and TexanolRTM are widely use in the latex coatings industry to facilitate film formation at ambient temperature. Coalescent aids are composed of solvents with low evaporation rates. After water evaporates, coalescent aids would help soften polymer molecules and form continuous films, then gradually evaporates from the film. Coalescent aids, therefore, are considered as volatile organic compounds (VOC), which are of environmental concern. The main purpose of this research project was to prepare a fatty acid glycol ester from soybean oil and glycol (polyols). The soybean oil glycol ester can be used as a coalescent aid in latex paint formulation. The soybean oil glycol ester not only lowered the minimum film formation temperature of latex polymers and continuous film formed at ambient temperature, but also after it has facilitated film formation, does not substantially evaporate, but becomes part of the film. Soybean oil glycol esters, therefore, can reduce the VOC levels and facilitate film formation of latex paints. In the second part of this research AC-Impedance was used to investigate the efficiency of soybean oil coalescent aid in latex film formation relative to the conventional ones. The coating resistance showed that the efficiency of film formation was increased as a function of dry time. The coating resistance also exhibited the effect of soybean oil ester in latex film formation in the same fashion as a conventional coalescent aid, TexanolRTM.

  17. Use of micrometric latex beads to improve the porosity of hydroxyapatite obtained by chemical coprecipitation method

    Science.gov (United States)

    Webler, G. D.; Rodrigues, W. C.; Silva, A. E. S.; Silva, A. O. S.; Fonseca, E. J. S.; Degenhardt, M. F. S.; Oliveira, C. L. P.; Otubo, L.; Barros Filho, D. A.

    2018-04-01

    Hydroxyapatite is one of the most important biomaterials whose application mainly extends to implants and drug delivery. This work will discuss the changes in the pore size distribution of hydroxyapatite when there are latex beads present during the synthesis. These changes were monitored using different techniques: small angle X-ray scattering, X-ray diffraction, thermal gravimetrical analysis, N2 adsorption, scanning and transmission electron microscopy. Latex beads and hydroxyapatite form a single nanocomposite with well-distinguished inorganic and organic phases. Latex bead removal in the temperature range of 300-600 °C did not modify the original crystalline structure of hydroxyapatite. However, the latex beads favored an increase in the adsorption capacity of mesopores at temperatures higher than their glassy transition (Tg). The main result of this research work consists on the increase of surface area and pore size distribution obtained after the removal of latex beads template. Latex beads have been used in a different approach changing the porosity of hydroxyapatite scaffolds not only introducing new routes for cell integration but also broadening the pore size distribution which can result in a more high efficiency for drug release in living cells.

  18. Preparation of novel film-forming armoured latexes using silica nanoparticles as a pickering emulsion stabiliser.

    Science.gov (United States)

    Shiraz, Hana; Peake, Simon J; Davey, Tim; Cameron, Neil R; Tabor, Rico F

    2018-05-15

    Film-forming polymer latex particles of diameter acrylate (BA) as co-monomers, potassium persulphate (KPS) as an initiator and a commercially available colloidal nano-silica (Ludox®-TM40). It was found that pH control before polymerisation using methacrylic acid (MAA) facilitated the formation of armoured latexes, and mechanistic features of this process are discussed. An alternative, more robust protocol was developed whereby addition of vinyltriethoxysilane (VTES) to control wettability resulted in latexes completely armoured in colloidal nano-silica. The latexes were characterised using SEM, cryo-TEM and AFM imaging techniques. The mechanism behind the adsorption was investigated through surface pressure and contact angle measurements to understand the factors that influence this irreversible adsorption. Results indicate that nanoparticle attachment (but intriguingly not latex size) is dependent on particle wettability, providing new insight into the formation of nanoparticle-armoured latexes, along with opportunities for further development of diversely functionalized inorganic/organic polymer composite particles. Copyright © 2018 Elsevier Inc. All rights reserved.

  19. Biodegradability and aging study of rubber films obtained by gamma radiation vulcanization processes of latex

    International Nuclear Information System (INIS)

    Martins, Carlos Felipe Pinto

    2005-01-01

    The natural rubber latex (NRL) is industrially crosslinked by the conventional process of vulcanization, which uses sulphur and heat. Otherwise, the network can also be done by the alternative process with ionizing radiation. In this work the crosslinking of NRL was studied by the comparison of the conventional vulcanization system and the ionizing radiation process of 60 C source. The products obtained, the irradiated latex, the irradiated latex with approximately 1% of soy lecithin and the sulphur vulcanized latex were tested by accelerated aging with ultraviolet (UV) and outdoor aging with compostage, tensile strength at break, swelling and gel fraction, fungi micro biota, scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and thermogravimetry and differential scanning calorimetry analysis (TG and DSC). The results showed that the aging with microorganisms have a great influence in the physical properties of the samples. The thermal stability order observed showed that the sulphur vulcanized latex is more resistant, what is probably associated to a network more stable under the aging conditions. On the other hand, the irradiated latex showed intense biodegradation aspects, particularly with the presence of the soy lecithin. (author)

  20. Capacitance Regression Modelling Analysis on Latex from Selected Rubber Tree Clones

    International Nuclear Information System (INIS)

    Rosli, A D; Baharudin, R; Hashim, H; Khairuzzaman, N A; Mohd Sampian, A F; Abdullah, N E; Kamaru'zzaman, M; Sulaiman, M S

    2015-01-01

    This paper investigates the capacitance regression modelling performance of latex for various rubber tree clones, namely clone 2002, 2008, 2014 and 3001. Conventionally, the rubber tree clones identification are based on observation towards tree features such as shape of leaf, trunk, branching habit and pattern of seeds texture. The former method requires expert persons and very time-consuming. Currently, there is no sensing device based on electrical properties that can be employed to measure different clones from latex samples. Hence, with a hypothesis that the dielectric constant of each clone varies, this paper discusses the development of a capacitance sensor via Capacitance Comparison Bridge (known as capacitance sensor) to measure an output voltage of different latex samples. The proposed sensor is initially tested with 30ml of latex sample prior to gradually addition of dilution water. The output voltage and capacitance obtained from the test are recorded and analyzed using Simple Linear Regression (SLR) model. This work outcome infers that latex clone of 2002 has produced the highest and reliable linear regression line with determination coefficient of 91.24%. In addition, the study also found that the capacitive elements in latex samples deteriorate if it is diluted with higher volume of water. (paper)

  1. Latex Rubber Gloves as a Sampling Dosimeter Using a Novel Surrogate Sampling Device.

    Science.gov (United States)

    Sankaran, Gayatri; Lopez, Terry; Ries, Steve; Ross, John; Vega, Helen; Eastmond, David A; Krieger, Robert I

    2015-01-01

    Pesticide exposure during harvesting of crops occurs primarily to the workers' hands. When harvesters wear latex rubber gloves for personal safety and hygiene harvesting reasons, gloves accumulate pesticide residues. Hence, characterization of the gloves' properties may be useful for pesticide exposure assessments. Controlled field studies were conducted using latex rubber gloves to define the factors that influence the transfer of pesticides to the glove and that would affect their use as a residue monitoring device. A novel sampling device called the Brinkman Contact Transfer Unit (BCTU) was constructed to study the glove characteristics and residue transfer and accumulation under controlled conditions on turf. The effectiveness of latex rubber gloves as sampling dosimeters was evaluated by measuring the transferable pesticide residues as a function of time. The validation of latex rubber gloves as a residue sampling dosimeter was performed by comparing pesticide transfer and dissipation from the gloves, with the turf transferable residues sampled using the validated California (CA) Roller, a standard measure of residue transfer. The observed correlation (Pearson's correlation coefficient R(2)) between the two methods was .84 for malathion and .96 for fenpropathrin, indicating that the BCTU is a useful, reliable surrogate tool for studying available residue transfer to latex rubber gloves under experimental conditions. Perhaps more importantly, these data demonstrate that latex gloves worn by workers may be useful quantifiable matrices for measuring pesticide exposure.

  2. Enhanced protein adsorption and patterning on nanostructured latex-coated paper.

    Science.gov (United States)

    Juvonen, Helka; Määttänen, Anni; Ihalainen, Petri; Viitala, Tapani; Sarfraz, Jawad; Peltonen, Jouko

    2014-06-01

    Specific interactions of extracellular matrix proteins with cells and their adhesion to the substrate are important for cell growth. A nanopatterned latex-coated paper substrate previously shown to be an excellent substrate for cell adhesion and 2D growth was studied for directed immobilization of proteins. The nanostructured latex surface was formed by short-wavelength IR irradiation of a two-component latex coating consisting of a hydrophilic film-forming styrene butadiene acrylonitrile copolymer and hydrophobic polystyrene particles. The hydrophobic regions of the IR-treated latex coating showed strong adhesion of bovine serum albumin (cell repelling protein), fibronectin (cell adhesive protein) and streptavidin. Opposite to the IR-treated surface, fibronectin and streptavidin had a poor affinity toward the untreated pristine latex coating. Detailed characterization of the physicochemical surface properties of the latex-coated substrates revealed that the observed differences in protein affinity were mainly due to the presence or absence of the protein repelling polar and charged surface groups. The protein adsorption was assisted by hydrophobic (dehydration) interactions. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Latex Imaging by Environmental STEM: Application to the Study of the Surfactant Outcome in Hybrid Alkyd/Acrylate Systems

    OpenAIRE

    Faucheu , Jenny; Chazeau , Laurent; Gauthier , Catherine; Cavaille , Jean-Yves; Goikoetxea , Monika; Minari , Roque; Asua , Jose M.

    2009-01-01

    International audience; Among other uses. latexes are a successful alternative to solvent-borne binders for coatings. Efforts are made to produce hybrid nanostructured latexes containing an acrylic phase and an alkyd phase, However, after the film-forming process, the surfactant used to stabilize these latexes remains in the film, and its location can have a drastic effect on the application properties. Among the processing parameters, the alkyd hydrophobicity can strongly influence this loca...

  4. Optimisation of Ultrasound-Assisted Extraction Conditions for Phenolic Content and Antioxidant Capacity from Euphorbia tirucalli Using Response Surface Methodology

    Science.gov (United States)

    Vuong, Quan V.; Goldsmith, Chloe D.; Dang, Trung Thanh; Nguyen, Van Tang; Bhuyan, Deep Jyoti; Sadeqzadeh, Elham; Scarlett, Christopher J.; Bowyer, Michael C.

    2014-01-01

    Euphorbia tirucalli (E. tirucalli) is now widely distributed around the world and is well known as a source of traditional medicine in many countries. This study aimed to utilise response surface methodology (RSM) to optimise ultrasonic-assisted extraction (UAE) conditions for total phenolic compounds (TPC) and antioxidant capacity from E. tirucalli leaf. The results showed that ultrasonic temperature, time and power effected TPC and antioxidant capacity; however, the effects varied. Ultrasonic power had the strongest influence on TPC; whereas ultrasonic temperature had the greatest impact on antioxidant capacity. Ultrasonic time had the least impact on both TPC and antioxidant capacity. The optimum UAE conditions were determined to be 50 °C, 90 min. and 200 W. Under these conditions, the E. tirucalli leaf extract yielded 2.93 mg GAE/g FW of TPC and exhibited potent antioxidant capacity. These conditions can be utilised for further isolation and purification of phenolic compounds from E. tirucalli leaf. PMID:26785074

  5. Effects of growth retardants and fumigations with ozone and sulfur dioxide on growth and flowering of Euphorbia pulcherrima Willd

    Energy Technology Data Exchange (ETDEWEB)

    Cathey, H.M.; Heggestad, H.E.

    1973-01-01

    Eight cultivars of poinsettia, Euphorbia pulcherrima Willd., were evaluated for sensitivity to ..cap alpha..-cyclopropyl-..cap alpha.. (4-methoxyphenyl)-5-pyrimidine methanol (ancymidol) and protection from ozone and sulfur dioxide injury afforded by applications of ancymidol and (2-chloroethyl) trimethyl ammonium chloride (chlormequat). Foliar sprays of ancymidol were at least 80 to 500 times and the soil drench 1000 times more active than chlormequat in retarding stem elongation. The diam of the bracts was reduced, but branching increased more on plants treated with ancymidol than on untreated plants. The cv. Annette Hegg (AH) was more sensitive to ozone fumigations than was Eckespoint C-1' (C-1). Sulfur dioxide also caused more injury to AH than to C-1. Ancymidol and chlormequat reduced visible injury induced by ozone and sulfur dioxide.

  6. The physicochemical quality and meat microstructure of post laying hen with addition of Biduri (Calotropis gigantea) latex extract

    Science.gov (United States)

    Nuhriawangsa, A. M. P.; Hertanto, B. S.; Kartikasari, L. R.; Swastike, W.; Cahyadi, M.; Rasid, S.

    2018-01-01

    The objective of this study was to evaluate the effect of extract level of Biduri latex on the meat quality of laying hens. The materials of this research were Biduri latex and thigh meat from hens strain Lohman. The latex was tapped from a young tissue stem and centrifuged for its supernatant. Meats were smeared with latex, punctured and incubated for 30 minutes. Concentrations of latex were 0, 3, 6 and 9% from the weight of meat (w/w). The variables were water, dissolved protein, crude fat content, tenderness and microstructure of meat. The statistical analysis method using ANOVA and if there was a mean difference, Duncan test was used. Descriptive analysis was used for microstructures of meat by comparing its hydrolysis conditions. The study showed that fat had significant difference (P meat structure. The fat content increased with addition of 3% latex. The value of dissolved protein increased but tenderness decreased by addition extract of 6% latex. The addition of Biduri latex extract showed that hydrolysis in the microstructure of meat. The addition of 6% latex was the best meat quality.

  7. Latex imaging by environmental STEM: application to the study of the surfactant outcome in hybrid alkyd/acrylate systems.

    Science.gov (United States)

    Faucheu, Jenny; Chazeau, Laurent; Gauthier, Catherine; Cavaillé, Jean-Yves; Goikoetxea, Monika; Minari, Roque; Asua, José M

    2009-09-01

    Among other uses, latexes are a successful alternative to solvent-borne binders for coatings. Efforts are made to produce hybrid nanostructured latexes containing an acrylic phase and an alkyd phase. However, after the film-forming process, the surfactant used to stabilize these latexes remains in the film, and its location can have a drastic effect on the application properties. Among the processing parameters, the alkyd hydrophobicity can strongly influence this location. This article aims at the imaging of these surfactant molecules in two hybrid latexes with different hydrophobicity level of the alkyd resin. A first part of this paper is dedicated to the understanding of the contrast provided by the surfactant in environmental STEM imaging of latexes. Then, the influence of surfactant-polymer affinity on the surfactant location after film-forming of those hybrid alkyd/acrylate latexes is studied by this technique. It is shown that in the hybrid latex with an alkyd shell (obtained with the most hydrophilic resin), the surfactant molecules tend to remain buried in the alkyd phase. Conversely, in the hybrid latex with an acrylate shell (in the case of the most hydrophobic resin), the surfactant molecules tend to gather into islands like in pure acrylate latex films.

  8. Ciprofloxacin release using natural rubber latex membranes as carrier.

    Science.gov (United States)

    Dias Murbach, Heitor; Jaques Ogawa, Guilherme; Azevedo Borges, Felipe; Romeiro Miranda, Matheus Carlos; Lopes, Rute; Roberto de Barros, Natan; Guedes Mazalli, Alexandre Vinicius; Gonçalves da Silva, Rosângela; Ferreira Cinman, José Luiz; de Camargo Drago, Bruno; Donizetti Herculano, Rondinelli

    2014-01-01

    Natural rubber latex (NRL) from Hevea brasiliensis is easily manipulated, low cost, is of can stimulate natural angiogenesis and cellular adhesion, is a biocompatible, material and presents high mechanical resistance. Ciprofloxacin (CIP) is a synthetic antibiotic (fluoroquinolone) used in the treatment of infection at external fixation screws sites and remote infections, and this use is increasingly frequent in medical practice. The aim of this study was to develop a novel sustained delivery system for CIP based on NRL membranes and to study its delivery system behavior. CIP was found to be adsorbed on the NRL membrane, according to results of energy dispersive X-ray spectroscopy. Results show that the membrane can release CIP for up to 59.08% in 312 hours and the mechanism is due to super case II (non-Fickian). The kinetics of the drug release could be fitted with double exponential function X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy shows some interaction by hydrogen bound, which influences its mechanical behavior.

  9. Improving of Water Resistance of Asphalt Concrete Wearing Course Using Latex-Bitumen Binder

    Directory of Open Access Journals (Sweden)

    Siswanto Henri

    2017-01-01

    Full Text Available It is well known that presence of water in a bituminous mix is a critical factor which can lead to premature failure of flexible pavements. This requires solutions one of which is to formulate an asphalt mix that has a high resistance to moisture and one way to do this is to mix latex with the asphalt mix. The purpose of this experimental study was to investigate the effect of water on Marshall stability of asphalt concrete wearing course (ACWC made with a latex-bitumen binder. Latex-bitumen was mixed with aggregate and four levels of latex content were investigated in this study, namely, 0%, 2%, 4% and 6% respectively by weight of asphalt. Wet procces was used in the blending of mixtures. The procedure used to obtain the optimum binder contents conformed to the Marshall procedure (SNI 06-2489-1991. Six Marshall specimens at optimum binder content were prepared for each binder mix investigated. Three of six specimens from each group were tested under Marshall standards. The remaining specimens were tested by immersion in a bath at 60°C for 24 hours. The Marshall index of retained stability was used to evaluate the effect of water on the Marshall stability of ACWC. The results indicated that the addition of up to 4% latex to ACWC mix increased the retained Marshall stability, whereas the addition of latex above 4% decreased the retained stability of the mixture. The addition of 4% CRM significantly improved the retained stability of the mixture and was the best latex – ACWC mix.

  10. Changes in chemical permeation of disposable latex, nitrile, and vinyl gloves exposed to simulated movement.

    Science.gov (United States)

    Phalen, Robert N; Le, Thi; Wong, Weng Kee

    2014-01-01

    Glove movement can affect chemical permeation of organic compounds through polymer glove products. However, conflicting reports make it difficult to compare the effects of movement on chemical permeation through commonly available glove types. The aim of this study was to evaluate the effect of movement on chemical permeation of an organic solvent through disposable latex, nitrile, and vinyl gloves. Simulated whole-glove permeation testing was conducted using ethyl alcohol and a previously designed permeation test system. With exposure to movement, a significant decrease (p ≤ 0.001) in breakthrough time (BT) was observed for the latex (-23%) and nitrile gloves (-31%). With exposure to movement, only the nitrile glove exhibited a significant increase (p ≤ 0.001) in steady-state permeation rate (+47%) and cumulative permeation at 30 min (+111%). Even though the nitrile glove provided optimum chemical resistance against ethyl alcohol, it was most affected by movement. With exposure to movement, the latex glove was an equivalent option for overall worker protection, because it was less affected by movement and the permeation rate was lower than that of the nitrile glove. In contrast, the vinyl glove was the least affected by movement, but did not provide adequate chemical resistance to ethyl alcohol in comparison with the nitrile and latex gloves. Glove selection should take movement and polymer type into account. Some glove polymer types are less affected by movement, most notably the latex glove in this test. With nitrile gloves, at least a factor of three should be used when attempting to assign a protection factor when repetitive hand motions are anticipated. Ultimately, the latex gloves outperformed nitrile and vinyl in these tests, which evaluated the effect of movement on chemical permeation. Future research should aim to resolve some of the observed discrepancies in test results with latex and vinyl gloves.

  11. DNA barcoding in a biodiversity hot spot: potential value for the identification of Malagasy Euphorbia L. listed in CITES Appendices I and II.

    Science.gov (United States)

    Aubriot, Xavier; Lowry, Porter P; Cruaud, Corinne; Couloux, Arnaud; Haevermans, Thomas

    2013-01-01

    The island of Madagascar is a key hot spot for the genus Euphorbia, with at least 170 native species, almost all endemic. Threatened by habitat loss and illegal collection of wild plants, nearly all Malagasy Euphorbia are listed in CITES Appendices I and II. The absence of a reliable taxonomic revision makes it particularly difficult to identify these plants, even when fertile, and thereby compromises the application of CITES regulations. DNA barcoding, which can facilitate species-level identification irrespective of developmental stage and the presence of flowers or fruits, may be a promising tool for monitoring and controlling trade involving threatened species. In this study, we test the potential value of barcoding on 41 Euphorbia species representative of the genus in Madagascar, using the two widely adopted core barcode markers (matK and rbcL), along with two additional DNA regions, nuclear internal transcribed spacer (ITS) and the chloroplastic intergenic spacer psbA-trnH. For each marker and for selected marker combinations, inter- and intraspecific distance estimates and species discrimination rates are calculated. Results using just the 'official' barcoding markers yield overlapping inter- and intraspecific ranges and species discrimination rates below 60%. When ITS is used, whether alone or in combination with the core markers, species discrimination increases to nearly 100%, whereas the addition of psbA-trnH produces less satisfactory results. This study, the first ever to test barcoding on the large, commercially important genus Euphorbia shows that this method could be developed into a powerful identification tool and thereby contribute to more effective application of CITES regulations. © 2012 Blackwell Publishing Ltd.

  12. Study of Antibacterial Activity and Bacteriology of Latex from Asclepias syriaca L

    Science.gov (United States)

    McCay, Steven; Mahlberg, Paul

    1973-01-01

    Whole and fractionated latex of Asclepias syriaca was tested for antimicrobial or growth-promoting activity with 16 genera and species of bacteria. Latex and extracted fractions (distilled water, acetic acid, sodium bicarbonate, sulfuric acid, and ethyl ether) possessed no detectable antimicrobial activity. Comparison of growth curves of selected bacteria incubated with serum and rubber fractions, as well as controls, revealed no detectable inhibition of growth, except for a slight inhibitory response to autoclaved serum. Most bacteria were capable of utilizing latex for a substrate as indicated by the increased growth rate in the exponential phase. The stationary phase was entered simultaneously by both the treated cultures and the controls. Various bacteria cultured in a litmus latex mixture yielded populations which ranged from <104 organisms/ml for Lactobacillus casei, Staphylococcus aureus and Micrococcus lysodeikticus to 1.1 × 1010 organisms/ml for Clostridium acetobutylicum. Whole latex, as well as the serum and rubber fractions, support the growth of various bacteria, but under field conditions there is no evidence for systemic infection of this type of cell by bacteria. PMID:4790590

  13. Latex allergy: new insights to explain different sensitization profiles in different risk groups.

    Science.gov (United States)

    Peixinho, C; Tavares-Ratado, P; Tomás, M R; Taborda-Barata, L; Tomaz, C T

    2008-07-01

    Differences in latex allergen sensitization profiles have been described between children subjected to repetitive surgical interventions and health care workers (HCW). 'Major' allergens for patients with spina bifida are Hev b 1, 3 and 7, while for HCW, 'major' allergens are Hev b 2, 5, 6.01 and 13. The reason for these differential sensitization profiles is currently unknown. To investigate latex allergen profiles on internal and external surfaces of natural rubber latex gloves. Eighty-two samples of commonly used surgical gloves (41 glove brands) were used for analysis. Specific allergen levels of Hev b 1, 3, 5 and 6.02 on both surfaces of the gloves were quantified using an enzyme immunometric assay, a FITkit (FIT Biotech, Tampere, Finland). Differences in allergen levels were observed between internal and external surfaces of all glove types. Concentrations of Hev b 1 and Hev b 3 were significantly higher on external surfaces, while internal surfaces had higher allergen levels of Hev b 5 and Hev b 6.02. Analysis of surgical and examination gloves, powdered and nonpowdered gloves also showed that the content of Hev b 5 and Hev b 6.02 was significantly higher on internal surfaces while that of Hev b 1 and Hev b 3 was higher on external surfaces. Our study showed different allergen profiles on internal and external surfaces of natural rubber latex gloves. These results may suggest a relationship between latex allergen localization and sensitization routes in different risk groups.

  14. Color Spectrum Properties of Pure and Non-Pure LATEX in Discriminating Rubber Clone Series

    International Nuclear Information System (INIS)

    Noor Aishah Khairuzzaman; Hadzli Hashim; Nina Korlina Madzhi; Noor Ezan Abdullah; Faridatul Aima Ismail; Ahmad Faiz Sampian; Azhana Fatnin Che Will

    2015-01-01

    A study of color spectrum properties for pure and non-pure latex in discriminating rubber clone series has been presented in this paper. There were five types of clones from the same series being used as samples in this study named RRIM2002, RRIM2007, RRIM2008, RRIM2014, and RRIM3001. The main objective is to identify the significant color spectrum (RGB) from pure and non-pure latex that can discriminate rubber clone series. The significant information of color spectrum properties for pure and non-pure latex is determined by using spectrometer and Statistical Package for the Social Science (SPSS). Visible light spectrum (VIS) is used as a radiation light of the spectrometer to emit light to the surface of the latex sample. By using SPSS software, the further numerical analysis of color spectrum properties is being conducted. As the conclusion, blue color spectrum for non-pure is able to discriminate for all rubber clone series whereas only certain color spectrum can differentiate several clone series for pure latex. (author)

  15. Rubber/clay nanocomposites by combined latex compounding and melt mixing: A masterbatch process

    International Nuclear Information System (INIS)

    Tan, Jinghua; Wang, Xiaoping; Luo, Yuanfang; Jia, Demin

    2012-01-01

    Highlights: → Rubber/Ca-montmorillonite nanocomposites were prepared by the masterbatch process. → Latex compounding method is efficient to improve the Ca-montmorillonite dispersion. → Exfoliated structure was obtained in the masterbatch by latex compounding method. → Intercalated and exfoliated structures were achieved in the vulcanizate. → The properties of vulcanizate are improved by the addition of Ca-montmorillonite. -- Abstract: Rubber/Ca-montmorillonite (Ca-MMT) nanocomposites with well exfoliated Ca-MMT layers were prepared by combination of latex compounding and melt mixing. Firstly, a high Ca-MMT content masterbatch was co-coagulated by natural rubber (NR) latex and modified Ca-MMT aqueous suspension through latex compounding. The masterbatch was added in the system of styrene butadiene rubber (SBR) and epoxidized natural rubber (ENR) by melt mixing subsequently. The X-ray diffraction (XRD) and transmission electronic microscopy (TEM) results showed that intercalated and exfoliated nanocomposites were obtained by the masterbatch technique. The effects of modified Ca-MMT introduction into the rubber matrix, via the masterbatch technique, on the properties of the resulting composites were studied. It was found that the vulcanization was hindered by the incorporation of modified Ca-MMT, while mechanical performances, thermal stability and aging resistance were improved. The increasingly glass transition temperature and the storage modulus with the loading of modified Ca-MMT were measured by dynamic mechanical analysis (DMA).

  16. Status RVNRL in German latex industry and its introduction to the European market

    International Nuclear Information System (INIS)

    Bez, W.

    1996-01-01

    Reasons to look for an alternative crosslinking system avoiding sulphur curing was the restrictive policy of the German Health Authorities concerning nitrosamines. It was concluded that radiation curing offers further advantages . By avoiding the accelerators, type IV allergy is excluded, cytotoxicity is minimised to a very low level, films have better clarity and when thoroughly leached higher electrical resistance. Treatment of waste give no SO sub 2 emissions by burning, no Zinc in the ashes and possibly better microbial degradation. A development was carried out to irradiate natural latex by electron beam with a Dynamitron equipment. It was found trimethylolpropanetrimethacrylate to be a suitable sensitizer. Because of to high prices this development was interrupted. For future application trials and efforts to introduce RVNRL in the market gamma ray radiated natural latex either from Batan, Indonesia or MINT, Malaysia are used. Mainly dipped goods were produce, but radiated natural latex has shown good results in other processes. During discussions with customers it has proved necessary to establish specifications for RVNRL. A serious problem using natural latex for the production of medical devices is the type I allergy. Attempts are made to dip surgical gloves, leach them thoroughly and control extractable proteins were reduced to the very low level of 6.5 μg/g. Out of 18 patients sensitive to natural latex protein wearing gloves made from RVNRL only six have shown a positive response. That means RVNRL could help to solve the protein allergy problem. Further developments on this line are scheduled

  17. Labbtex: Toolbox para generación de informes en LATEX para Matlab

    Directory of Open Access Journals (Sweden)

    José Luis Almazán Gárate

    2012-10-01

    Full Text Available En este artículo se presenta el software desarrollado por el Equipo H3lite dentro del Departamento de Ingeneniería Civil. Transportes de la Escuela de Ingenieros de Caminos, Canales y Puertos de la Universidad Politécnica de Madrid para la generación de informes enLATEX mediante el software Matlab® y la integración en sus rutinas, Labbtex.La librería Labbtex proporciona un marco flexible para mezclar texto y código Matlab® para la generación automática de documentos. Un rchivo fuente simple contiene el texto de documentación y el código Matlab, al correr la aplicación se genera un documento final LATEX que contiene el texto, gráficos y tablas indicados con el formato de un documento LATEX. El código Matlab genera un documento LATEX usando la sintaxis. Así, LATEX (para composición de texto de alta calidad y Matlab® (para cálculo matemático pueden usarse simultáneamente. Esto permite la generación de informes en tiempo real con un uso de recursos mínimo.

  18. Ingestion et digestibilité in vivo du Panicum maximum associé à trois compléments: tourteau de Jatophra curcas, tourteau de coton Gossypium hirsutum et Euphorbia heterophylla chez le cobaye Cavia porcellus L

    Directory of Open Access Journals (Sweden)

    N'G.D.V. Kouakou

    2010-01-01

    Full Text Available The Intake and the in vivo Digestibility of Panicum maximum Associated with Three Supplements: Jatophra curcas Cake, Gossypium hirsutum Cake and Euphorbia heterophylla (Euph in Guinea Pigs (Cavia porcellus L.. The intake and the in vivo digestibility of Panicum maximum associated with three supplements: Jatropha curcas cake, Gossypium hirsutum cake and Euphorbia heterophylla (Euph in guinea pigs (Cavia porcellus L. pigs, its association with Panicum maximum could be popularized wherever its abundance has been reported. In order used weed Euphorbia heterophylla in guinea pigs diet, comparative study of the intake and the in vivo digestibility of four treatments, Panicum maximum (Pan, Panicum maximum and Gossypium hirsutum cake (Pancoton, Panicum maximum and Euphorbia heterophylla (Paneuph and Panicum maximum and Jatropha curcas cake (Panjatro, in male guinea pigs were conducted in Yamoussoukro (Ivory Coast. The means of the intake (g DM/d were 64.8 ± 12.5; 74.3 ± 12.9; 73.7 ± 17.8 and 69.1 ± 12.3 respectively for Pan, Pancoton, Paneuph and Panjatro. Pancoton and Paneuph were significantly better ingested than Pan and Panjatro. Euphorbia heterophylla was significantly better ingested than the other two supplements (P< 0.05 and the mean daily weight gain with its association with Panicum maximum of 3.1 ± 0.6 g/d. The rate of substitution of Panicum maximum by Euphorbia heterophylla was nearly to one (1. The apparent digestibility coefficients (ADC for dry (68.0 ± 10.5% and organic matter (84.1 ± 5.2% of Paneuph were significantly higher (P< 0.05 than the ADC's for the other three treatments. Given the nutritional value of Euphorbia heterophylla in guinea pigs, its association with Panicum maximum could be popularized wherever its abundance has been reported.

  19. Silver nanoparticles delivery system based on natural rubber latex membranes

    International Nuclear Information System (INIS)

    Guidelli, Éder José; Kinoshita, Angela; Ramos, Ana Paula; Baffa, Oswaldo

    2013-01-01

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV–Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane (∼0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.Graphical AbstractThe AgNP attached to the cis-isoprene molecules remain in the NRL matrix and only the AgNP bound to the non-rubber molecules (NRL serum fraction) are released. The released AgNP are sterically

  20. Silver nanoparticles delivery system based on natural rubber latex membranes

    Energy Technology Data Exchange (ETDEWEB)

    Guidelli, Eder Jose, E-mail: ederguidelli@gmail.com [Universidade de Sao Paulo/FFCLRP-DF (Brazil); Kinoshita, Angela [Universidade do Sagrado Coracao (Brazil); Ramos, Ana Paula [Universidade de Sao Paulo/FFCLRP-DQ (Brazil); Baffa, Oswaldo [Universidade de Sao Paulo/FFCLRP-DF (Brazil)

    2013-04-15

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV-Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane ({approx}0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.Graphical AbstractThe AgNP attached to the cis-isoprene molecules remain in the NRL matrix and only the AgNP bound to the non-rubber molecules (NRL serum fraction) are released. The released AgNP are

  1. Natural rubber latex: past, present and future in Latin America

    International Nuclear Information System (INIS)

    Lugao, A.B.; Miranda, A.; Mindrisz, A.C.; Andrade e Silva, L.G. de

    1996-01-01

    The origin of the Hevea braziliensis tree was the Amazonian region in South America, particularly the Brazilian jungle. The rubber expansion at the end of 9th century brought prosperity and determined the borders of Amazonian countries. In spite of that, the Brazilian government has failed in establishing a successful policy for improving the NR production in the jungle. However, rubber plantations were successfully introduced recently near marginal areas of the humid forest in the Amazon due to the absence of the fungus Microcyclos ulei. Both, extraction of wild rubber and plantation have a key role in the maintenance of the forest health. The market for dipping products is small but is growing very fast and is expected to follow this pattern as the sanitary conditions are improved by the health authority. The history of the Brazilian NR products industry is contemporary and is based on the policy of market protection and on the lack of investments due to extremely high interest rates. As a result, the industry was not competitive. It was concluded that, in order to cope with the future challenge, the industry is required to invest in very modern technologies to produce first class goods with international acceptance. Latin America would follow the world trend for nitrosamine and protein free products. The radiation vulcanization of natural rubber latex could prove itself as a profitable solution and not only a quality solution. It was also concluded that both wild rubber and rubber plantations in Brazil have their future coupled with the future of a regional dipping industry. Moreover, the buildup of the dipping industry will be beneficial to the protection of the humid forest and the recovery of degraded areas

  2. Radiation graft copolymerization of n-butyl acrylate on natural rubber latex

    International Nuclear Information System (INIS)

    Sundardi, F.; Kadariah, S.

    1986-01-01

    A method of radiation graft copolymerization of n-butyl acrylate (NBA) on natural rubber (NR) latex has been studied. The rate of conversion increases with the increase of NBA in latex. An irradiation dose of about 12 kGy is needed to obtain 90% conversion with 40 phr of NBA in latex. Tensile strength, tear strength, and elongation at break of grafted NR are found to decrease with increasing degree of grafting. The physical strength of a vulcanizate prepared from a mixture of NR and ply-NBA was found to be better than that of NBA-NR graft copolymer vulcanizate. The graft copolymerization reaction takes place in the outer layer of NR particles, and because the secondary bonds between poly-NBA molecules may be weaker than those between NR molecules, the existence of a poly-NBA layer in NR particles will decrease its physical strength

  3. Effects of radio sensitizers in the vulcanization of natural rubber latex induced by gamma radiation

    International Nuclear Information System (INIS)

    Souza, A. de; Canavel, V.; Araujo, S.C. de; Guedes, S.M.L.

    1992-01-01

    The effect of C Cl 4 and n-butyl acrylate as a sensitizer for radiation vulcanization of 60% DRC natural rubber latex with gamma rays, was studied relating tensile strength of vulcanized latex. The vulcanization dose is 200 kGy for natural rubber latex and it decreases to 40 kGy and to 9 kGy in the presence of C Cl 4 / potassium laureate and n-butyl acrylate / t-butyl hydroperoxide, respectively. The H 2 O 2 as a co-sensitizer does not change the efficiency of the combination of these sensitizers. The IV spectra show the formation of C=O after the irradiation as consequence of oxidation reactions. (author)

  4. Extractable proteins from electron beam (EB) irradiated natural rubber (NR) latex

    International Nuclear Information System (INIS)

    Feroza Akhtar; Fumio Yoshii; Keizo Makuuchi

    1996-01-01

    The protein assay of natural rubber latex (NRL) vulcanized by low energy electron beam (EB, 300 keV, 30 mA) has been carried out using Bicinchoninic acid (BCA) reagent. Extractable protein in irradiated latex film was determined by measuring the absorption of colored solution at 562 nm using UV spectrometer. The effect of various radiation doses on the extractable protein content of NRL was investigated. It was ,found that the quantities of extractable protein increases with radiation dose. When compared with ,gamma-ray irradiated samples the same trend was observed. Electron beam irradiated latex films are leached in 1% (ammonia water for various lengths of time. From the results it was established that within 2 hours of leaching in ammonia water most of the extractable protein (96%) were removed from rubber film

  5. Extraction and comparison of proteins from natural rubber latex by conventional and ionizing radiation methods

    International Nuclear Information System (INIS)

    Rogero, Sizue O.; Spencer, Patrick J.; Campos, Vania E.; Lusvarghi, Fabio M.; Higa, Olga Z.

    1997-01-01

    Several proteins in natural rubber latex (NRL) have been assigned to be significant allergens. It is known that proteins submitted to ionizing radiation suffer denaturation and immunochemical modification resulting in low antigenic reactivity. The aim of this study was to extract and compare water extractable proteins from NRL films vulcanized by conventional and by ionizing radiation methods. SDS-polyacrylamide gel electrophoresis (SDS--PAGE) and high pressure liquid chromatography (HPLC) showed a diffuse protein band of about 14 KDa, which we believe is rubber elongation factor (REF), in both eluates, but smaller in latex film vulcanized by ionizing radiation. REF has been suggested to be a major latex allergen. These data suggest that ionizing radiation vulcanization could be an useful method for the production of NRL goods with low antigenicity. (author). 8 refs., 2 figs., 1 tab

  6. Trialed production of low protein irradiated natural rubber latex in factory scale by gamma irradiation technique

    International Nuclear Information System (INIS)

    Utama, Marga; Herwinarni, S.; Halik, H.M.; Siswanto; Suharyanto; Syamsu, Y.; Handoko, B.

    2006-01-01

    Four tons fresh field natural rubber latex (FNRL) with total solid content 30% were added with 2 phr (part hundred ratio of rubber) normal butyl acrylate (nBA) then irradiated by gamma rays at 25 kGy. The irradiated FNRL was centrifuged, then the properties of irradiated centrifuged natural rubber latex (INRL) and its film were measured before and after storage for 5 months. It is found that the INRL is stable latex during storage in 5 months, with lowest protein, and free nitrosamine content. The tensile strength of INRL film was 24-27 MPa, and modulus 600% was 1,5-2,0 MPa, elongation at break was 900%, and hardness was 27-29 Shore A, while the extractable protein content less than 100 μg/g. (author)

  7. Development assessment of natural latex membranes: a new proposal for the treatment of amblyopia

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Jaqueline Alves; Rosa, Suelia Rodrigues Fleury, E-mail: jackalvesribeiro@gmail.com [Laboratorio de Engenharia e Biomaterial (BioEngLab), Faculdade Gama, Universidade de Brasilia (UnB), DF (Brazil); Leite, Cicilia Raquel Maia; Vasconcelos, Claudio Lopes; Soares, Joao Maria [Universidade do Estado do Rio Grande do Norte (UERN), Mossoro, RN (Brazil)

    2017-05-15

    The ophthalmic dysfunction amblyopia, commonly known as lazy eye, is characterized by decreased vision in one eye due to improper development in childhood. The aim of this study was to obtain and characterize natural rubber membranes and to assess their utility as an eye film capable of altering the passage of light. The latex membranes were produced using the Van Gogh method and the deposition technique and were analyzed by physical and chemical methods to determine the properties of latex in natura and of natural rubber membranes. The materials were characterized by X-ray diffractometry, scanning electron microscopy, thermogravimetry, differential scanning calorimetry, analysis of water sorption and light crossing analysis. We report here a new approach to the treatment of patients with amblyopia using latex membranes. (author)

  8. Development assessment of natural latex membranes: a new proposal for the treatment of amblyopia

    International Nuclear Information System (INIS)

    Ribeiro, Jaqueline Alves; Rosa, Suelia Rodrigues Fleury; Leite, Cicilia Raquel Maia; Vasconcelos, Claudio Lopes; Soares, Joao Maria

    2017-01-01

    The ophthalmic dysfunction amblyopia, commonly known as lazy eye, is characterized by decreased vision in one eye due to improper development in childhood. The aim of this study was to obtain and characterize natural rubber membranes and to assess their utility as an eye film capable of altering the passage of light. The latex membranes were produced using the Van Gogh method and the deposition technique and were analyzed by physical and chemical methods to determine the properties of latex in natura and of natural rubber membranes. The materials were characterized by X-ray diffractometry, scanning electron microscopy, thermogravimetry, differential scanning calorimetry, analysis of water sorption and light crossing analysis. We report here a new approach to the treatment of patients with amblyopia using latex membranes. (author)

  9. Isolation rubber latex binary composites consisting of cotton and poly-N, N-dimethyl-N, N-diallilammony chloride

    Directory of Open Access Journals (Sweden)

    J. Cornejo Tueros

    2012-01-01

    Full Text Available The paper discusses the application of rubber from latex binary coagulating agent consisting of cotton - textile waste and polymeric quaternary ammonium salts. The influence on the process of extracting rubber from latex flow coagulating agent temsperatury and concentration of the dispersed phase.

  10. Production Of Hollow Toy Product From Radiation Pre vulcanized Natural Rubber Latex (RVNRL) By Using Casting And Moulding Technique

    International Nuclear Information System (INIS)

    Mohd Noorwadi Mat Lazim; Sofian Ibrahim; Muhammad Saiful Omar

    2013-01-01

    Hollow toy products are very synonym to the child from the age of months since it able to stimulating each of their sense such as sight, hearing, taste, touch and smell. Most of hollow toy products are made from natural rubber latex by using moulding and casting technique. The moulding and casting technique is a manufacturing process by pored liquid latex into a mould, which contain cavity of the desired shape. The mould made from plaster of Paris able to absorbs water from latex meanwhile the presence of calcium ions from plaster of Paris will tend to diffuse into latex thus promote formation of deposit on surface of cavity mould. To improve the quality and safety of hollow toy product made from latex, Radiation Pre vulcanized Natural Rubber Latex (RVNRL) has been identified to be used because it can fulfill the standard requirement for latex and also due to its special abilities such as lower modulus (soft latex products), nitrosamines free, low in nitrosatables, free from chemical accelerators induced allergies and better biodegradability. This paper identify the problem appears from the process of making hollow toy products from RVNRL by using moulding and casting technique. (author)

  11. Preliminary study of semi-refined carrageenan (SRC) as secondary gelling agent in natural rubber (NR) latex foam

    Science.gov (United States)

    Norhazariah, S.; Azura, A. R.; Azahari, B.; Sivakumar, R.

    2017-12-01

    Semi-refined carrageenan (SRC) product is considerably cheaper and easier to produce as a natural polysaccharide, which was utilized in food and other product application. However, the application in latex is limited. The aim of this work is to evaluate the SRC produced from low industrial grade seaweed (LIGS) in the latex foam application. The FTIR spectra showed the SRC produced as kappa type carrageenan with lower sulfur content compared to native LIGS. NR latex foam is produced by using the Dunlop method with some modifications. The effect of SRC loading as a secondary gelling agent in NR latex foam is investigated. The density and morphology of the NR latex foam with the addition of the SRC are analyzed. NR latex foam density increased with SRC loading and peaked at 1.8 phr SRC. The addition of SRC has induced the bigger cell size compared to the cell size of the control NR latex foam, as shown in the optical micrograph. It can be concluded that SRC LIGS could be acted as secondary gelling agent in NR latex foam.

  12. Interferência de populações de Euphorbia heterophylla e Ipomoea ramosissima isoladas ou em misturas sobre a cultura de soja Interference of populations of Euphorbia heterophylla and Ipomoea ramosissima isolated or in mixture in soybean crop

    Directory of Open Access Journals (Sweden)

    M.A. Rizzardi

    2004-03-01

    Full Text Available Dentre as principais espécies daninhas que infestam as lavouras de soja do sul do Brasil, destacam-se Euphorbia heterophylla (leiteira e, mais recentemente, Ipomoea ramosissima (corda-de-viola. Objetivou-se avaliar a habilidade competitiva relativa entre espécies daninhas e soja e quantificar a interferência de infestações mistas de leiteira e corda-de-viola quando em convivência com plantas de soja. Foram conduzidos dois experimentos, comparando associações de leiteira ou corda-de-viola com soja, utilizando-se cinco proporções de plantas de leiteira e soja ou corda-de-viola e soja (0:8; 2:6; 4:4; 6:2; 8:0. Em um terceiro experimento, mantiveram-se constantes quatro plantas de soja por vaso e utilizaram-se cinco proporções de plantas de leiteira e corda-de-viola (0:8; 2:6; 4:4; 6:2; 8:0, estabelecidas em duas épocas de emergência das plantas daninhas em relação à soja. Verificou-se que a redução na biomassa da soja é mais intensa quando em presença de corda-de-viola do que de leiteira e, principalmente, em situações nas quais a planta daninha se estabelece antes que a cultura. Quando em infestação mista, corda-de-viola é mais competitiva do que leiteira.Euphorbia heterophylla (wild poinsettia, and, more recently, Ipomoea ramosissima (morningglory are among the main weeds infesting soybean crop in southern Brazil. This work aimed to evaluate the effects of wild poinsettia and morningglory as single or mixed populations in coexistence with soybean. Two experimentswere conducted to compare associations of wild poinsettia or moningglory with soybean, using five ratios of wild poinsettia plants and soybean or morningglory (0:8, 2:6, 4:4, 6:2 and 8:0. In a third experiment, four soybean plants per pot were kept constant and five ratios of of wild poinsettia and moningglory plants were used (0:8, 2:6, 4:4, 6:2 and 8:0, established in two weed emergence periods related to the soybean. The results indicated that a higher

  13. Aplicações seqüenciais de flumicloracpentil para o controle de Euphorbia heterophylla na cultura da soja = Sequential application of flumicloracpentil for Euphorbia heterophylla control in soybeans

    Directory of Open Access Journals (Sweden)

    Rubem Silvério de Oliveira Jr

    2006-01-01

    Full Text Available Euphorbia heterophylla destacase como a principal planta daninha na cultura da soja no Estado do Paraná, não só pela sua disseminação, mas também pela natural dificuldade de controle e pela ocorrência de biótipos que apresentam resistência. Em face de tais problemas, buscou se avaliar a eficácia de aplicações seqüenciais em pós emergência de flumicloracpentil no controle dessa planta daninha. As aplicações seqüenciais de flumicloracpentil foram superiores, em termos de eficácia, às doses recomendadas em aplicação única, promovendo no mínimo 86% de controle aos 24 dias após a aplicação dasegunda etapa das seqüenciais. Todas as combinações de doses de flumicloracpentil avaliadas promoveram controle adequado de E. heterophylla, desde que aplicadas no estádio de duas folhas verdadeiras. Comparando se os resultados obtidos em casadevegetaçãoe em estufa, observou se que, em condições de campo, o sombreamento imposto pela soja auxilia no nível de controle final da planta daninha.Wild poinsettia (Euphorbia heterophylla is one the most importantweeds in soybean fields in the state of Paraná, not only for its dissemination, but also due to its natural difficulty of controlling features by herbicides and to occurrence of resistant biotypes. Facing those problems, an evaluation of the field and greenhouse trials was carried out in order to check the efficacy of postemergencesequential application of flumicloracpentil to control this weed. Sequential applications of flumicloracpentil were more efficientthan a single application, promoting, at least, 86% of weed control on the 24th day after the second application of the sequential treatments. All the evaluated combinations of flumiclorac rates once sprayed at two true leaves stage, promoted adequate control of E. heterophylla. Comparing the greenhouse and the field results, it was concluded that, under field conditions, the canopy provided by the crop helps to improve the

  14. Hierarchically structured self-supported latex films for flexible and semi-transparent electronics

    International Nuclear Information System (INIS)

    Määttänen, Anni; Ihalainen, Petri; Törngren, Björn; Rosqvist, Emil; Pesonen, Markus; Peltonen, Jouko

    2016-01-01

    Graphical abstract: - Highlights: • Transparent self-supported latex films were fabricated by a peel-off process. • Various template substrates were used for creating e.g. hierarchically structured latex films. • Ultra-thin and semi-transparent conductive gold electrodes were evaporated on the latex films.Electrochemical experiments were carried out to verify the applicability of the electrodes. - Abstract: Different length scale alterations in topography, surface texture, and symmetry are known to evoke diverse cell behavior, including adhesion, orientation, motility, cytoskeletal condensation, and modulation of intracellular signaling pathways. In this work, self-supported latex films with well-defined isotropic/anisotropic surface features and hierarchical morphologies were fabricated by a peel-off process from different template surfaces. In addition, the latex films were used as substrates for evaporated ultrathin gold films with nominal thicknesses of 10 and 20 nm. Optical properties and topography of the samples were characterized using UV–vis spectroscopy and Atomic Force Microscopy (AFM) measurements, respectively. The latex films showed high-level transmittance of visible light, enabling the fabrication of semi-transparent gold electrodes. Electrochemical impedance spectroscopy (EIS) measurements were carried out for a number of days to investigate the long-term stability of the electrodes. The effect of 1-octadecanethiol (ODT) and HS(CH_2)_1_1OH (MuOH) thiolation and protein (human serum albumin, HSA) adsorption on the impedance and capacitance was studied. In addition, cyclic voltammetry (CV) measurements were carried out to determine active medicinal components, i.e., caffeic acid with interesting biological activities and poorly water-soluble anti-inflammatory drug, piroxicam. The results show that the fabrication procedure presented in this study enables the formation of platforms with hierarchical morphologies for multimodal (optical and

  15. Hierarchically structured self-supported latex films for flexible and semi-transparent electronics

    Energy Technology Data Exchange (ETDEWEB)

    Määttänen, Anni, E-mail: anni.maattanen@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Ihalainen, Petri, E-mail: petri.ihalainen@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Törngren, Björn, E-mail: bjorn.torngren@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Rosqvist, Emil, E-mail: emil.rosqvist@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Pesonen, Markus, E-mail: markus.pesonen@abo.fi [Physics, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland); Peltonen, Jouko, E-mail: jouko.peltonen@abo.fi [Laboratory of Physical Chemistry, Faculty of Science and Engineering, Center for Functional Materials, Åbo Akademi University, Porthaninkatu 3, 20500, Turku (Finland)

    2016-02-28

    Graphical abstract: - Highlights: • Transparent self-supported latex films were fabricated by a peel-off process. • Various template substrates were used for creating e.g. hierarchically structured latex films. • Ultra-thin and semi-transparent conductive gold electrodes were evaporated on the latex films.Electrochemical experiments were carried out to verify the applicability of the electrodes. - Abstract: Different length scale alterations in topography, surface texture, and symmetry are known to evoke diverse cell behavior, including adhesion, orientation, motility, cytoskeletal condensation, and modulation of intracellular signaling pathways. In this work, self-supported latex films with well-defined isotropic/anisotropic surface features and hierarchical morphologies were fabricated by a peel-off process from different template surfaces. In addition, the latex films were used as substrates for evaporated ultrathin gold films with nominal thicknesses of 10 and 20 nm. Optical properties and topography of the samples were characterized using UV–vis spectroscopy and Atomic Force Microscopy (AFM) measurements, respectively. The latex films showed high-level transmittance of visible light, enabling the fabrication of semi-transparent gold electrodes. Electrochemical impedance spectroscopy (EIS) measurements were carried out for a number of days to investigate the long-term stability of the electrodes. The effect of 1-octadecanethiol (ODT) and HS(CH{sub 2}){sub 11}OH (MuOH) thiolation and protein (human serum albumin, HSA) adsorption on the impedance and capacitance was studied. In addition, cyclic voltammetry (CV) measurements were carried out to determine active medicinal components, i.e., caffeic acid with interesting biological activities and poorly water-soluble anti-inflammatory drug, piroxicam. The results show that the fabrication procedure presented in this study enables the formation of platforms with hierarchical morphologies for multimodal

  16. Functional characterization of the Hyles euphorbiae hawkmoth transcriptome reveals strong expression of phorbol ester detoxification and seasonal cold hardiness genes.

    Science.gov (United States)

    Barth, M Benjamin; Buchwalder, Katja; Kawahara, Akito Y; Zhou, Xin; Liu, Shanlin; Krezdorn, Nicolas; Rotter, Björn; Horres, Ralf; Hundsdoerfer, Anna K

    2018-01-01

    The European spurge hawkmoth, Hyles euphorbiae (Lepidoptera, Sphingidae), has been intensively studied as a model organism for insect chemical ecology, cold hardiness and evolution of species delineation. To understand species isolation mechanisms at a molecular level, this study aims at determining genetic factors underlying two adaptive ecological trait candidates, phorbol ester (TPA) detoxification and seasonal cold acclimation. A draft transcriptome of H. euphorbiae was generated using Illumina sequencing, providing the first genomic resource for the hawkmoth subfamily Macroglossinae. RNA expression levels in tissues of experimental TPA feeding larvae and cooled pupae was compared to levels in control larvae and pupae using 26 bp RNA sequence tag libraries (DeepSuperSAGE). Differential gene expression was assessed by homology searches of the tags in the transcriptome. In total, 389 and 605 differentially expressed transcripts for detoxification and cold hardiness, respectively, could be identified and annotated with proteins. The majority (22 of 28) of differentially expressed detox transcripts of the four 'drug metabolism' enzyme groups (cytochrome P450 (CYP), carboxylesterases (CES), glutathione S-transferases (GST) and lipases) are up-regulated. Triacylglycerol lipase was significantly over proportionally annotated among up-regulated detox transcripts. We record several up-regulated lipases, GSTe2, two CESs, CYP9A21, CYP6BD6 and CYP9A17 as candidate genes for further H. euphorbiae TPA detoxification analyses. Differential gene expression of the cold acclimation treatment is marked by metabolic depression with enriched Gene Ontology terms among down-regulated transcripts almost exclusively comprising metabolism, aerobic respiration and dissimilative functions. Down-regulated transcripts include energy expensive respiratory proteins like NADH dehydrogenase, cytochrome oxidase and ATP synthase. Gene expression patterns show shifts in carbohydrate

  17. Effect of cellulose nanocrystals from corn cob with dispersion agent polyvinyl pyrrolidone in natural rubber latex film after aging treatment

    Science.gov (United States)

    Harahap, H.; Ridha, M.; Halimatuddahliana; Taslim; Iriany

    2018-02-01

    This study about the resistance of natural rubber latex films using nanocrystals cellulose filler from corn cob waste by aging treatment. Corn cob used as organic filler composed of cellulose, hemicellulose, and lignin. Each component has a potential for reuse, such as cellulose. Cellulose from corn cob has potential application as a filler prepared by hydrolysis process using a strong acid. The producing of natural rubber latex films through coagulant dowsing process. This research started with the pre-vulcanization process of natural rubber latex at 70 °C and followed by process of vulcanization at 110 °C for 20 minutes. Natural rubber latex films that have been produced continued with the aging treatment at 70 °C for 168 hours. The mechanical properties of natural rubber latex films after aging treatment are the tensile strength, elongation at break, M100 and M300 have performed.

  18. Effect of rootstock on the scion of Hevea brasiliensis through metabolic analysis of latex samples by 1H NMR

    Directory of Open Access Journals (Sweden)

    Eduardo Sanches Pereira do Nascimento

    2011-01-01

    Full Text Available In this study, the effect of rootstock on grafting through metabolomic analysis of latex (Hevea brasiliensis samples was verified by 1H nuclear magnetic resonance (NMR and multivariate data analysis. Sixteen metabolites present in the latex cytosol were characterized by NMR. PCA analysis showed that the latex samples of the RR and GR groups can be differentiated. The GR group samples present a metabolic profile similar to the RR group samples, while the RG group is in an intermediate position between RR and GG groups. Sucrose and formate contributed greatly to the separation obtained by PCA, presenting a good correlation between the results. 1H NMR was an efficient technique to differentiate latex samples from different types of rootstocks and grafting and in the future could be used to predict rubber production by latex analysis.

  19. The evolution and use of a personal LaTeX metapackage

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth

    This document defines and describes esameta.sty and its variant esametaps.sty. They are personal LATEX packages that largely consist of calls of other packages. These 'metapackages' are selected to help the development of the author's complex book and paper projects-but some of his decisions migh...... be of more general relevance. The use of the LATEX system of 'literate programming' and the testing the compatibility of new commands and packages with the previously included parts of the metapackage should also be noticed....

  20. Mechanism of n-butyl acrylate sensitization action in radiation vulcanization of natural rubber latex

    International Nuclear Information System (INIS)

    Sabharwal, S.; Chaudhari, C.V.; Bhardwaj, Y.K.; Majali, A.B.; Das, T.N.

    1996-01-01

    In order to understand the role of n-butyl acrylate (nBA) in radiation vulcanization of natural rubber latex, pulse radiolysis technique has been utilized to study the reactions of the transient species produced by reaction of OH . , e- aq and H . atoms with nBA in aqueous solutions. The results show that transients produced by reaction of e- aq with nBA alone are capable of propagating the polymerization reaction and enhance the vulcanization process. These results have been further confirmed by studying the effect of electron scavengers on the vulcanization behaviour of natural rubber latex in presence of nBA. (author). 3 refs., 3 figs

  1. Radiation vulcanization of natural rubber latex using 250 keV electron beam machine

    Energy Technology Data Exchange (ETDEWEB)

    Chirinos, H.; Yoshii, F.; Makuuchi, K.; Lugao, A. E-mail: ablugao@net.ipen.br

    2003-08-01

    The sensitized radiation vulcanization of natural rubber latex has been carried out with 250 keV electrons. Latex was irradiated over a range of the beam current from 5 to 20 mA in the presence of sensitizers like the n-butyl acrylate (n-BA). The vulcanization dose decreases with increasing beam current condition. The rate of vulcanization (R{sub vul}) depends on the beam current (I) as given by the equation R{sub vul}=kI{sup 0.6}.

  2. Anticancer activity of flavonol and flavan-3-ol rich extracts from Croton celtidifolius latex.

    Science.gov (United States)

    Biscaro, Fernanda; Parisotto, Eduardo Benedetti; Zanette, Vanilde Citadini; Günther, Tania Mara Fischer; Ferreira, Eduardo Antonio; Gris, Eliana Fortes; Correia, João Francisco Gomes; Pich, Claus Tröger; Mattivi, Fulvio; Filho, Danilo Wilhelm; Pedrosa, Rozangela Curi

    2013-06-01

    Croton celtidifolius Baill (Euphorbiaceae) is a tree found in the Atlantic Forest in Southern Brazil, where it is commonly known as "Sangue-de-Dragão". Its red latex is used traditionally for treating ulcers, diabetes and cancer. To evaluate antitumor activities of Croton celtififolius latex in vitro and in vivo. Phytochemical analyses were conducted using HPLC-DAD-MS. Cytotoxic, nuclease and pro-apoptotic properties were determined using the tetrazolium salt assay (MTT), plasmid DNA damage assay and ethidium bromide (EB)/acridine orange methods, respectively, and antitumor activity was determined in the Ehrlich ascites carcinoma (EAC) mouse model. Phytochemical studies indicated a high phenol content of flavonols (45.67 ± 0.24 and 18.01 ± 0.23 mg/mL of myricetin and quercetin, respectively) and flavan-3-ols (114.12 ± 1.84 and 1527.41 ± 16.42 mg/L of epicatechin and epigallocatechin, respectively) in latex. These compounds reduced MCF-7 and EAC cell viability in the MTT assay (IC50 = 169.0 ± 1.8 and 187.0 ± 2.2 μg/mL, respectively). Latex compounds caused significant DNA fragmentation and increased the number of apoptotic cells (negative control (NC), 12%; latex, 41%) as indicated by differential staining in the EB/acridine orange assay. The in vivo latex treatment at 3.12 mg/kg/day reduced the body weight by 7.57 ± 2.04 g and increased median survival time to 17.5 days when compared to the NC group (13.0 days). In addition, the highest latex concentration inhibited tumor growth by 56%. These results agree with ethno-pharmacological reports showing cytotoxicity and antitumor activity of C. celtidifolius latex. The mechanism of antitumor action may be related to direct DNA fragmentation that reduces survival and induces apoptosis.

  3. Trial Production of Surgical Gloves from Irradiated Natural Rubber Latex on Factory Scale

    Directory of Open Access Journals (Sweden)

    M. Utama

    2005-07-01

    Full Text Available Trial production of surgical gloves from irradiated natural rubber latex at the PT. Laxindo Utama Serang Banten glove factory has been carried out. The variation of heating temperature and leaching time during processing were evaluated. The physical and mechanical properties and the protein allergen respond of surgical gloves using ELISA method were measured. The results showed that the physical and mechanical of surgical gloves such as tensile strength, modulus, and elongation at break arefound to meet the requirements of the ISO or SNI standard for surgical gloves. While the allergic response through clinical tested latex-sensitive protein allergen known as ELISA test is found to be negative.

  4. Radiation Vulcanization of Natural Rubber Latex (RVNRL): A Potential Material for Nuclear Power Plant Gloves

    International Nuclear Information System (INIS)

    Pairu Ibrahim; Wan Manshol Wan Zain; Keong, C.C.; Mohd Noorwadi Mat Lazim

    2011-01-01

    Radiation vulcanization of natural rubber latex has great potential for the production of nuclear power plant gloves due to its low ash and mineral content. And this is in-line with the role played by Malaysian Nuclear Agency as Technical Supporting Organization for Nuclear Power Program. This paper discussed the evaluation done to determine ash content in RVNRL and SVNRL films. Both samples were prepared using casting technique and the properties were compared. Films prepared from raw latex without any vulcanizing agent were regarded as a control. (author)

  5. Gamma irradiator design concepts for radiation vulcanisation of natural rubber latex

    International Nuclear Information System (INIS)

    Aggarwal, K.S.; Muralidharan, P.; Apte, M.G.; Kalurkar, A.R.; Shah, B.M.

    1990-01-01

    Radiation vulcanisation of natural rubber latex (NRL) is a new and yet unproven technology and one which involves undefined problems of consumer acceptance and high degree of radiation risk. Therefore, the designer should take care that the initial capital cost of the plant is as low as possible to keep the unit processing cost low during the initial lean period of the product requirement by the market. Three irradiators to process natural rubber latex have been designed as per capacity requirement of the user. Their salient features are described. (author). 2 tabs., 24 figs

  6. Low field NMR study of the latex derived from Brosimum parinarioides - Moraceae

    International Nuclear Information System (INIS)

    Miguez, Eduardo; Tavares, Maria Ines B.

    2009-01-01

    Brosimum parinarioides is a tree found in the Amazonia forest and its latex (Leite de Amapa) is often used like food and by the popular medicine in the treatment of tuberculosis and asthma. Being swallowed in nature, its necessary determinate the stability degree of this latex in the storage conditions in which is used in Amazonia. The analyses of T 2 data showed that the limit of stability is not longer than six month in the storage conditions used by the population of Amazonia. The Low field NMR proved to be an efficient method for this kind of study. (author)

  7. Mechanical and morphological properties of kenaf powder filled natural rubber latex foam

    Energy Technology Data Exchange (ETDEWEB)

    Karim, Ahmad Fikri Abdul, E-mail: a.fikri-89@yahoo.com; Ariff, Zulkifli Mohamad [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Pulau Pinang (Malaysia); Ismail, Hanafi [Cluster for Polymer Composites (CPC), Science and Engineering Research Centre, Engineering Campus, Universiti Sains Malaysia,14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-07-22

    This research is carried out by incorporate kenaf powder with natural rubber latex (NRL) compound and is foamed to make natural rubber latex foam (NRLF) by using a well known technique called Dunlop method. Different loading of kenaf powder was added to NRL compound and was foamed to make NRLF. The tensile properties, and morphology of kenaf filled NRLF was studied. Increase in kenaf loading reduced the tensile strength and elongation at break and of a compound. Modulus at 100% elongation of the compound increased with increased in filler loading. The morphological and micro structural characterization has been performed by using scanning electron microscopy (SEM)

  8. Mechanical and morphological properties of kenaf powder filled natural rubber latex foam

    International Nuclear Information System (INIS)

    Karim, Ahmad Fikri Abdul; Ariff, Zulkifli Mohamad; Ismail, Hanafi

    2015-01-01

    This research is carried out by incorporate kenaf powder with natural rubber latex (NRL) compound and is foamed to make natural rubber latex foam (NRLF) by using a well known technique called Dunlop method. Different loading of kenaf powder was added to NRL compound and was foamed to make NRLF. The tensile properties, and morphology of kenaf filled NRLF was studied. Increase in kenaf loading reduced the tensile strength and elongation at break and of a compound. Modulus at 100% elongation of the compound increased with increased in filler loading. The morphological and micro structural characterization has been performed by using scanning electron microscopy (SEM)

  9. Variabilidade genética em biotipos de leiteiro de Londrina/PR Genetic variability among Euphorbia heterophylla

    Directory of Open Access Journals (Sweden)

    Maria José V. de Vasconcelos

    2000-08-01

    Full Text Available Euphorbia heterophylla, também conhecida como amendoim-bravo ou leiteira, é considerada planta invasora importante em mais de 56 países, inclusive no Brasil, tendo acarretado perdas de até 33 % na cultura da soja. Fenotipicamente, é uma espécie de características variáveis, especialmente em relação ao formato do limbo foliar. Esta variabilidade fenotípica tem sido utilizada para diferenciar e classificar as plantas, sugerindo a vários autores que a leiteira seria, de fato, constituída por diferentes espécies. Para estudar a variabilidade genética a nível de DNA entre plantas de Euphorbia heterophylla, que apresentam folhas morfologicamente diferentes, foram analisadas dez plantas diferentes coletadas em campos de soja, em Londrina/PR. As plantas foram transplantadas para casa-devegetação e o DNA das folhas foi extraído para análise pela técnica de RAPD. Vinte seis diferentes "primers", de dez nucleotídeos de sequência aleatória, geraram total de 102 bandas de DNA, sendo 38 delas polimórficas. A distância genética entre os indivíduos foi calculada em função da presença e da ausência das bandas, variando de 1 a 39% entre plantas. A análise de agrupamento dividiu as plantas em dois grupos, considerando limite de distância relativa de 22%. Os grupos gerados separaram nitidamente as plantas quanto ao formato do limbo foliar (estreito ou arredondado e quanto á ramificação (densa ou normal.Euphorbia heterophylla is an important weed affecting the performance of annual and perennial crops. It is native from tropical and subtropical regions in the American continent, and has been detected at high densities in 20 different countries worldwide, and at low densities in other 40 countries. In Brazil, it has been inclued among the ten most important weeds affecting different crops, causing yield losses up to 33% in soybean fields. Phenotypically, this species is extremely variable, especially in relation to leaf shape and

  10. Analysis of Aqueous Extractable Protein in Radiation Pre vulcanized Natural Rubber Latex (RVNRL) And Sulphur Pre vulcanized Natural Rubber Latex (SVNRL)

    International Nuclear Information System (INIS)

    Sofian Ibrahim; Mohd Noor Wadi Mat Lazim; Syuhada Ramli; Keong, C.C.; Khairul Hisyam Mohd Yusof; Muhammad Saiful Omar; Najib Mohd Zakey; Hafizuddin Maseri; Noor Hasni Mohd Ali

    2015-01-01

    The use of radiation do not only produces Radiation Pre vulcanized Natural Rubber Latex (RVNRL) that can be used for the production of nitrosamines free products, moreover, RVNRL also able to exclude type IV allergy that caused by high protein content in the products. Leaching water from production of finger coat from RVNRL and Sulphur Pre vulcanized Natural rubber Latex (SVNRL) has been collected. Extractable protein content from water samples measured according to the test protocol ASTM D5712-2010. Water from leaching process of finger coat made from RVNRL showed a higher protein content than SVNRL. This explains why RVNRL based products contain very low protein content and thus reduce the risk of Type IV allergy. (author)

  11. Antimicrobial activity of a 48-kDa protease (AMP48) from Artocarpus heterophyllus latex.

    Science.gov (United States)

    Siritapetawee, J; Thammasirirak, S; Samosornsuk, W

    2012-01-01

    Artocarpus heterophyllus (jackfruit) is a latex producing plant. Plant latex is produced from secretory cells and contains many intergradients. It also has been used in folk medicine. This study aimed to purify and characterize the biological activities of a protease from jackfruit latex. A protease was isolated and purified from crude latex of a jackfruit tree by acid precipitation and ion exchange chromatography. The proteolytic activities of protein were tested using gelatin- and casein-zymography. The molecular weight and isoelectric point (pl) of protein were analysed by SDS/12.5% PAGE and 2D-PAGE, respectively. Antimicrobial activity of protein was analysed by broth microdilution method. In addition, the antibacterial activity of protein against Pseudomonas aeruginosa ATCC 27853 was observed and measured using atomic force microscopy (AFM) technique. The purified protein contained protease activity by digesting gelatin- and casein-substrates. The protease was designated as antimicrobial protease-48 kDa or AMP48 due to its molecular mass on SDS-PAGE was approximately 48 kDa. The isoelectric point (pl) of AMP48 was approximately 4.2. In addition, AMP48 contained antimicrobial activities by it could inhibit the growths of Pseudomonas aeruginosa ATCC 27853 and clinical isolated Candida albicans at minimum inhibitory concentration (MIC) 2.2 mg/ml and Minimum microbicidal concentration (MMC) 8.8 mg/ml. AFM image also supported the antimicrobial activities of AMP48 by the treated bacterial morphology and size were altered from normal.

  12. Reduction of residual monomer in latex products by enhanced polymerization and extraction in supercritical carbon dioxide

    NARCIS (Netherlands)

    Kemmere, M.F.; Schilt, van M.A.; Cleven, M.H.W.; Herk, van A.M.; Keurentjes, J.T.F.

    2002-01-01

    The redn. of Me methacrylate (MMA) in a PMMA latex was chosen as a representative model system. Pulsed electron beam expts. were performed to study the effect of supercrit. carbon dioxide (scCO2) on the monomer concn. inside the polymer particles during the polymn. reaction. The partitioning

  13. Evaluation of peptides release using a natural rubber latex biomembrane as a carrier.

    Science.gov (United States)

    Miranda, M C R; Borges, F A; Barros, N R; Santos Filho, N A; Mendonça, R J; Herculano, R D; Cilli, E M

    2018-05-01

    The biomembrane natural (NRL-Natural Rubber Latex), manipulated from the latex obtained from the rubber tree Hevea brasiliensis, has shown great potential for application in biomedicine and biomaterials. Reflecting the biocompatibility and low bounce rate of this material, NRL has been used as a physical barrier to infectious agents and for the controlled release of drugs and extracts. The aim of the present study was to evaluate the incorporation and release of peptides using a latex biomembrane carrier. After incorporation, the release of material from the membrane was observed using spectrophotometry. Analyses using HPLC and mass spectroscopy did not confirm the release of the antimicrobial peptide [W 6 ]Hylin a1 after 24 h. In addition, analysis of the release solution showed new compounds, indicating the degradation of the peptide by enzymes contained in the latex. Additionally, the release of a peptide with a shorter sequence (Ac-WAAAA) was evaluated, and degradation was not observed. These results showed that the use of NRL as solid matrices as delivery systems of peptide are sequence dependent and could to be evaluated for each sequence.

  14. Crystallization of Hevamine, an Enzyme with Lysozyme/Chitinase Activity from Hevea brasiliensis Latex

    NARCIS (Netherlands)

    ROZEBOOM, HJ; BUDIANI, A; BEINTEMA, JJ

    1990-01-01

    Hevamine, an enzyme with both lysozyme and chitinase activity, was isolated and purified from Hevea brasiliensis (rubber tree) latex. The enzyme (molecular weight 29,000) is homologous to certain “pathogenesis-related” proteins from plants, but not to hen egg-white or phage T4 lysozyme. To

  15. The effect of emulsifier on the stability of irradiated LA-TZ latex

    International Nuclear Information System (INIS)

    Made Sumarti K; Utama, Marga; Puspitasari, Tita

    1998-01-01

    The effect of six kinds of stabilizer on the stability of the concentrated LA-TZ latex which contains n-BA have been studied. The six stabilizers are: 1. Naphthalene sulfonic acid formaldehyde condensate, 2. Sodium dialkyl sulfosuccinate, 3. Triethanol amine lauryl sulfate, 4. Sodium polyoxyethylene alkyl phenol ether sulfate, 5. Dodecyl benzene sulfonic acid (Neopelex FS), and 6. Ammonium laurat. The concentrations of the stabilizers are in the range of 0,1 to 0,3% and of the n-BA is 5phr (per hundred rubber). The field natural rubber latex was stabilized by Tetramethyl tiuram disulfide - Zine oxide (TMTD-ZnO) and ammonium gas, and was concentrated by centrifuge. The obtain concentrated LA-TZ latex was added by the n-BA and was kept with various storage time i.e. o, 2, 4, 6, 18, and 24 hours. It was found that the stable latex was irradiated by 15 kGy dose and the physical properties was tested, then the maximum tensile strength of 223,3 kg/cm 2 was found on Neopelex FS concentrate at 0,1%. (authors)

  16. Enhancing Student Writing and Computer Programming with LATEX and MATLAB in Multivariable Calculus

    Science.gov (United States)

    Sullivan, Eric; Melvin, Timothy

    2016-01-01

    Written communication and computer programming are foundational components of an undergraduate degree in the mathematical sciences. All lower-division mathematics courses at our institution are paired with computer-based writing, coding, and problem-solving activities. In multivariable calculus we utilize MATLAB and LATEX to have students explore…

  17. Synthesis, Characterization and Gold Loading of Polystyrene-Poly(pyridyl methacrylate) Core-Shell Latex Systems

    NARCIS (Netherlands)

    Oláh, A.; Hempenius, Mark A.; Vancso, Gyula J.

    2004-01-01

    In this research, novel 3-(2-pyridyl)propyl methacrylate and 3-(3-pyridyloxy)propyl methacrylate monomers were synthesized and emulsion polymerized on colloidal polystyrene seeds, resulting in core–shell latex systems. The cores and the core–shell particles were characterized by static light

  18. Radiation prevulcanized natural rubber latex: Cytotoxicity and safety evaluation on animal

    Energy Technology Data Exchange (ETDEWEB)

    Keong, C C; Zin, W M Wan; Ibrahim, P; Ibrahim, S, E-mail: chai@nuclearmalaysia.gov.my [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

    2010-05-15

    Radiation prevulcanized natural rubber latex (RVNRL) was claimed to be more user friendly than natural rubber latex prevulcanized by sulphur curing system. The absence of Type IV allergy inducing chemicals in RVNRL make it a suitable material for manufacturing of many kinds of latex products, especially those come into direct contact with users. This paper reveals and discusses the findings of cytotoxicity test and safety evaluation on animal for RVNRL. The test was done on RVNRL films prepared by coagulant dipping method and RVNRL dipped products produced by latex dipped product manufacturers. Cytotocixity test was carried out on mammalian cell culture American Type Culture Collection CCL 81, Vero. Results indicated that no cytotoxic effect from RVNRL films and products was found on the cell culture. Two animal studies, namely dermal sensitization study and primary skin irritation study, were done on gloves made from RVNRL. Albino white guinea pigs were used as test subjects in dermal sensitization study and results showed no sensitization induced by the application of test material in the guinea pigs. Primary skin irritation study was done on New Zealand white rabbits and results showed that the product tested was not corrosive and was not a primary irritant

  19. Radiation vulcanization of natural rubber latex with low energy accelerator-II

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Md. Emdadul; Makuuchi, Keizo; Ikeda, Kenichi; Yoshii, Fumio; Kume, Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Faculty of Engineering, Dept. of Biological and Chemical Engineering, Kiryu, Gunma (Japan)

    2002-03-01

    The natural rubber latex (NRL) was radiation vulcanized under a low energy electron accelerator. Accelerating voltage and maximum beam current of this accelerator are 250 kV and 10 mA respectively. Irradiation was carried out in a reaction vessel with constant stirring. The capacity of the vessel is 18 liters. Radiation vulcanization accelerators (RVA) were normal butyl acrylate (n-BA) and nonane-diol-diacrylate (NDDA). NDDA has no bad smell like that of n-BA. 20 minutes irradiation time is enough to vulcanize 14 liters of latex when 5 phr RVA (both types) are used. Maximum of {approx}30 MPa tensile strength was obtained with 5 phr NDD-A. However the remained NDDA is difficult to remove due to high molecular weight. Water-extractable proteins content was determined in dipped films for various leaching conditions without and with additive (polyvinyl alcohol, PVA). Water extractable proteins content is reduced to {<=} 41 by adding 5 phr PVA and leaching for 8 hours. The tackiness of the dipped films is reduced to 0.1 from 9 gf by mixing 6 phr PVA with the irradiated latex. Hand gloves (surgical and examination) were successfully produced from the irradiated latex. (author)

  20. Latex paint as a delivery vehicle for diethylphthalate and di-n-butylphthalate

    DEFF Research Database (Denmark)

    Schripp, Tobias; Salthammer, Tunga; Fauck, Christian

    2014-01-01

    gas-phase concentration at steady state(y). For both, DEP and DnBP, the y0 obtained was lower than the respective saturation vapor pressure (Ps). Furthermore, for both phthalates in latex paint, the material/air partition coefficient (C0/y0) was close in value to the octanol/air partition coefficient...

  1. Marketing techniques and cost calculations of radiation vulcanised natural rubber latex (RVNRL)

    International Nuclear Information System (INIS)

    Wan Manshol Wan Zin; Chai Chee Keong; Najib Mohammed Zakey; Hafizuddin Maseri

    2005-01-01

    This paper describes how RVNRL is promoted to the latex based industries locally and abroad. RVNRL promotion requires patience and very challenging. This is a fact since the product is new to the market. Cost is important in deciding its market and potential usage. The elements that contribute to the cost is described in this paper. (Author)

  2. The effects of temperature and pH bacterial degradation of latex ...

    African Journals Online (AJOL)

    The goal of this study was to integrate the activities of paint deterioration of microbial communities (microcosms) on the basis of environmental factors. The effect of temperature and pH on bacterial degradation of latex paint under humid condition by bacterial isolates was studied. Results obtained revealed that paint ...

  3. THE PRIMARY STRUCTURE OF HEVAMINE, AN ENZYME WITH LYSOZYME CHITINASE ACTIVITY FROM HEVEA-BRASILIENSIS LATEX

    NARCIS (Netherlands)

    JEKEL, PA; HARTMANN, JBH; BEINTEMA, JJ

    1991-01-01

    The primary structure of hevamine, an enzyme with lysozyme/chitinase activity from Hevea brasiliensis latex, has been determined predominantly with conventional non-automatic methods. The positions of three disulfide bridges have been determined. The sequence has about 60% identity with that of a

  4. Lipid transfer protein from Hevea brasiliensis (Hev b 12), a cross-reactive latex protein

    NARCIS (Netherlands)

    Beezhold, Donald H.; Hickey, Vicky L.; Kostyal, David A.; Puhl, Henry; Zuidmeer, Laurian; van Ree, Ronald; Sussman, Gordon L.

    2003-01-01

    BACKGROUND: Latex-allergic individuals experience clinical cross-reactivity to a large number of fruits and vegetables. Much of the cross-reactivity can be attributed to Hev b 6, but evidence indicates that additional cross-reactive allergens may be present. A common pan-allergen, which has not

  5. Adsorption of immunoglobulin G on core-shell latex particles precoated with chaps

    NARCIS (Netherlands)

    Giacomelli, CE; Vermeer, AWP; Norde, W

    2000-01-01

    The aim of this work is to investigate the adsorption behavior of a monoclonal antibody (immunoglobulin G, IgG) on latex particles, possessing reactive chloromethyl groups, precoated with 3-([3-cholamidopropyl]dimethylammonio-1-propansulfonate (Chaps). The amount and reactivity of the surface

  6. Adsorption of immunoglobulin G on core-shell latex particles precoated with chaps

    NARCIS (Netherlands)

    Giacomelli, C.E.; Vermeer, A.W.P.; Norde, W.

    2000-01-01

    The aim of this work is to investigate the adsorption behavior of a monoclonal antibody (immunoglobulin G, IgG) on latex particles, possessing reactive chloromethyl groups, precoated with 3-([3-cholamidopropyl]dimethylammonio-1-propanesulfonate (Chaps). The amount and reactivity of the surface

  7. Costs and return analysis in rubber latex production in Edo State ...

    African Journals Online (AJOL)

    The study examined the costs and return analysis in rubber latex production in Edo Sate, Nigeria. Multi-stage sampling method was adopted to select 96 smallholder rubber framers for the study. The first stage was a purposive sampling of two LGAs and then simple random sampling of 6 villages each from the two LGA.

  8. Latex allergy: assessment of knowledge, appropriate use of gloves and prevention practice among hospital healthcare workers.

    Science.gov (United States)

    Al-Niaimi, F; Chiang, Y Z; Chiang, Y N; Williams, J

    2013-01-01

    Healthcare workers and patients are often exposed to natural rubber latex (NRL) through contact with gloves and various healthcare products, which can potentially cause allergic reactions, with varying degrees of severity. In 2008, the Royal College of Physicians published their first evidence-based guidance on occupational health interventions for latex allergy, which emphasized the importance of healthcare workers having knowledge of latex allergy. This study aimed to survey the knowledge of healthcare workers (n = 156) about latex gloves and NRL allergy, routine prevention practice and the appropriate use of gloves in patient care. Healthcare workers in a large teaching hospital were surveyed using a standard questionnaire. We found that only 1% of healthcare workers were able to correctly match the appropriate gloves to the specifically designed procedure. More than half (n = 74.53%) were unable to recognize the presentation of type 1 allergy to NRL. Of the 156 participants, 131 (84%) considered that they would benefit from training about NRL allergy and the use of different types of gloves in clinical care. This survey indicates the importance of education regarding appropriate use of gloves and prevention of NRL allergy among healthcare workers, and dermatologists should play an important role in facilitating this. © The Author(s). CED © 2012 British Association of Dermatologists.

  9. Formation of Defect-Free Latex Films on Porous Fiber Supports

    KAUST Repository

    Lively, Ryan P.

    2011-09-28

    We present here the creation of a defect-free polyvinylidene chloride barrier layer on the lumen-side of a hollow fiber sorbent. Hollow fiber sorbents have previously been shown to be promising materials for enabling low-cost CO 2 capture, provided a defect-free lumen-side barrier layer can be created. Film experiments examined the effect of drying rate, latex age, substrate porosity (porous vs nonporous), and substrate hydrophobicity/ hydrophilicity. Film studies show that in ideal conditions (i.e., slow drying, fresh latex, and smooth nonporous substrate), a defect-free film can be formed, whereas the other permutations of the variables investigated led to defective films. These results were extended to hollow fiber sorbents, and despite using fresh latex and relatively slow drying conditions, a defective lumen-side layer resulted. XRD and DSC indicate that polyvinylidene chloride latex develops crystallinity over time, thereby inhibiting proper film formation as confirmed by SEM and gas permeation. This and other key additional challenges associated with the porous hollow fiber substrate vs the nonporous flat substrate were overcome. By employing a toluene-vapor saturated drying gas (a swelling solvent for polyvinylidene chloride) a defect-free lumen-side barrier layer was created, as investigated by gas and water vapor permeation. © 2011 American Chemical Society.

  10. Diagnosis of toxoplasmosis in pregnancy. Evaluation of latex-protein complexes by immnunoagglutination.

    Science.gov (United States)

    Peretti, Leandro E; Gonzalez, Verónica D G; Marcipar, Iván S; Gugliotta, Luis M

    2017-07-01

    The aim of this work was to obtain a reagent based on latex particles for ruling out acute toxoplasmosis in pregnant women by immunoagglutination (IA). Latex-protein complexes (LPC) were previously synthesized coupling the recombinant protein of Toxoplasma gondii P22Ag and the homogenate of the parasite to latex particles with different size, chemical functionality and charge density. LPC were tested in IA assays against a panel of 72 pregnant women serum samples. Results were analysed through receiver operating characteristic curves, determining area under the curve (AUC), sensitivity, specificity positive and negative predictive values (PPV and NPV, respectively). It was observed that the antigenicity of proteins was not affected during sensitization by either physical adsorption or covalent coupling. The best results in the sense of maximizing discrimination of low avidity sera from chronic ones were observed for the IA test based on latex particles with carboxyl functionality and the recombinant P22Ag, obtaining an AUC of 0·94, a sensitivity of 100% and a NPV of 100%. In this way, the proposed test could be useful for the toxoplasmosis diagnosis in pregnant women, with the advantages of being cheap, rapid and easy to be implemented.

  11. Latex particle template lift-up guided gold wire-networks via evaporation lithography

    KAUST Repository

    Lone, Saifullah; Vakarelski, Ivan Uriev; Chew, Basil; Wang, Zhihong; Thoroddsen, Sigurdur T

    2014-01-01

    We describe a hybrid methodology that combines a two dimensional (2D) monolayer of latex particles (with a pitch size down to 1 μm) prepared by horizontal dry deposition, lift-up of a 2D template onto flat surfaces and evaporation lithography to fabricate metal micro- and nano wire-networks. This journal is

  12. Dynamics of ballistically injected latex particles in living human endothelial cells

    NARCIS (Netherlands)

    Li, Y.; Vanapalli Veera, V.S.A.R.; Vanapalli, Srinivas; Duits, Michael H.G.

    2009-01-01

    We studied the dynamics of ballistically injected latex particles (BIP) inside endothelial cells, using video particle tracking to measure the mean squared displacement (MSD) as a function of lag time. The MSD shows a plateau at short times and a linear behavior at longer times, indicating that the

  13. Insights on the Phytochemical Profile (Cyclopeptides and Biological Activities of Calotropis procera Latex Organic Fractions

    Directory of Open Access Journals (Sweden)

    Thiago Lustosa Jucá

    2013-01-01

    Full Text Available Calotropis procera is a medicinal plant whose pharmacological properties are associated with its latex. Here, the Calotropis procera latex fractions were investigated in an attempt to trace its phytochemical profile and measure its anti-inflammatory and toxicity activity. The crude latex was partitioned, yielding five fractions (49.4% hexane, 5.2% dichloromethane, 2.0% ethyl acetate, 2.1% n-butanol, and 41.1% aqueous. Phytochemical screening and spectroscopy analysis revealed that dichloromethane is the most chemically diverse fraction. Triterpenes were detected in both the hexane and dichloromethane fractions, while flavonoids were detected in the dichloromethane and ethyl acetate fractions. These fractions were cytotoxic to cancer cell lines (LD50 0.05 to 3.9 μg/mL and lethal to brine shrimp (LD50 10.9 to 65.7 μg/mL. Reduced neutrophil migration in rats was observed in carrageenan-induced peritonitis for the dichloromethane (67%, ethyl acetate (56%, and aqueous (72% fractions. A positive reaction with tolidine and ninhydrin suggested that cyclopeptides are in the ethyl acetate fraction. It is therefore concluded that Calotropis procera latex dichloromethane and ethyl acetate fractions exhibit both in vitro and in vivo activities as well as anti-inflammatory properties. Cyclopeptide detection is especially interesting because previous attempts to investigate these low-molecular cyclic amino acid sequences in C. procera have failed.

  14. Radiation prevulcanized natural rubber latex: Cytotoxicity and safety evaluation on animal

    International Nuclear Information System (INIS)

    Keong, C C; Zin, W M Wan; Ibrahim, P; Ibrahim, S

    2010-01-01

    Radiation prevulcanized natural rubber latex (RVNRL) was claimed to be more user friendly than natural rubber latex prevulcanized by sulphur curing system. The absence of Type IV allergy inducing chemicals in RVNRL make it a suitable material for manufacturing of many kinds of latex products, especially those come into direct contact with users. This paper reveals and discusses the findings of cytotoxicity test and safety evaluation on animal for RVNRL. The test was done on RVNRL films prepared by coagulant dipping method and RVNRL dipped products produced by latex dipped product manufacturers. Cytotocixity test was carried out on mammalian cell culture American Type Culture Collection CCL 81, Vero. Results indicated that no cytotoxic effect from RVNRL films and products was found on the cell culture. Two animal studies, namely dermal sensitization study and primary skin irritation study, were done on gloves made from RVNRL. Albino white guinea pigs were used as test subjects in dermal sensitization study and results showed no sensitization induced by the application of test material in the guinea pigs. Primary skin irritation study was done on New Zealand white rabbits and results showed that the product tested was not corrosive and was not a primary irritant

  15. [Detection of anti-Leptospira antibodies in sera of patients in the latex agglutination test].

    Science.gov (United States)

    Volina, E G; Sarukhanova, L E; Iashina, N V; Prokopov, N I; Shkarlat, P E; Barysheva, I V

    2001-01-01

    The results of the preliminary evaluation of the sensitivity and specificity of the newly developed diagnostic test based on the determination of genus-specific antibodies to leptospires in the latex agglutination test, are presented. This test makes it possible to detect anti-Leptospira antibodies of any serogroup. The advantages of the developed test have been determined.

  16. Dynamic speciation analysis of atrazine in aqueous latex nanoparticle dispersions using solid phase microextraction (SPME)

    NARCIS (Netherlands)

    Benhabib, K.; Town, R.M.; Leeuwen, van H.P.

    2009-01-01

    Solid phase microextraction (SPME) is applied in the dynamic speciation analysis of the pesticide atrazine in an aqueous medium containing sorbing latex nanoparticles. It is found that the overall rate of extraction of the analyte is faster than in the absence of nanoparticles and governed by the

  17. The use of Euphorbia falcata extract as eco-friendly corrosion inhibitor of carbon steel in hydrochloric acid solution

    International Nuclear Information System (INIS)

    El Bribri, A.; Tabyaoui, M.; Tabyaoui, B.; El Attari, H.; Bentiss, F.

    2013-01-01

    Euphorbia falcata L. extract (EFE) was investigated as eco-friendly corrosion inhibitor of carbon steel in 1 M HCl using gravimetric, ac impedance, polarization and scanning electron microscopy (SEM) techniques. The experimental results show that EFE is good corrosion inhibitor and the protection efficiency is increased with the EEF concentration. The results obtained from weight loss and ac impedance studies were in reasonable agreement. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Polarization curves indicated that EFE is a mixed inhibitor. The corrosion inhibition was assumed to occur via adsorption of EFE molecules on the metal surface. The adsorption of the E. falcata extract was well described by the Langmuir adsorption isotherm. The calculated ΔG ads o value showed that the corrosion inhibition of the carbon steel in 1 M HCl is mainly controlled by a physisorption process. - Graphical abstract: Display Omitted - Highlights: • EFE is a good eco-friendly inhibitor for the corrosion of carbon steel in 1 M HCl. • EFE acts as mixed-type inhibitor in 1 M HCl medium. • Weight loss, ac impedance and polarization methods are in reasonable agreement. • The adsorption of EFE is well described by the Langmuir adsorption isotherm

  18. Ethnopharmacological studies on the uses of Euphorbia hirta in the treatment of dengue in selected indigenous communities in Pangasinan (Philippines).

    Science.gov (United States)

    de Guzman, Gerard Quinto; Dacanay, Aleth Therese Lora; Andaya, Benjel Andaya; Alejandro, Grecebio Jonathan Duran

    2016-01-01

    Euphorbia hirta is the most widely used plant in the folkloric treatment of dengue in the Philippines. This study documents the anecdotal uses of E. hirta in the treatment of dengue in 3 indigenous communities in Pangasinan from April to June of 2015. The number of use reports pertaining to symptoms of dengue and other diseases were tallied from 82 informants living in Anda Island, Mt. Colisao and Mt. Balungao. The demographics of the informants as well as the corrected major use agreements (cMUAs) and fidelity levels (FLs) of each reported symptom of dengue were calculated. The major dosage forms used during treatment were also tallied. Respondents, dominated by the age group 60-80 and mostly females with at least primary and secondary education, provided information on the use reports of E. hirta. High FL values and cMUA of at least 35% were obtained for cardinal symptoms of dengue-related to bleeding episodes while low cMUAs (i.e. 2-4%) were obtained for symptoms during the recovery phase. High FL values were obtained for symptoms observed during the febrile phase. The most widely used dosage forms are decoctions of the leaves and barks of E. hirta. This study was able to qualify the uses of E. hirta in the treatment of dengue in the 3 communities surveyed.

  19. Anti-proliferation activity of terpenoids isolated from Euphorbia kansui in human cancer cells and their structure-activity relationship.

    Science.gov (United States)

    Hou, Jin-Jun; Shen, Yao; Yang, Zhou; Fang, Lin; Cai, Lu-Ying; Yao, Shuai; Long, Hua-Li; Wu, Wan-Ying; Guo, De-An

    2017-10-01

    Euphorbia kansui is a commonly used traditional Chinese medicine for the treatment of edema, pleural effusion, and asthma, etc. According to the previous researches, terpenoids in E. kansui possess various biological activities, e.g., anti-virus, anti-allergy, antitumor effects. In this work, twenty five terpenoids were isolated from E. kansui, including thirteen ingenane- and eight jatrophane-type diterpenoids (with two new compounds, kansuinin P and Q) and four triterpenoids. Eighteen of them were analyzed by MTS assay for in vitro anticancer activity in five human cancer cell lines. Structure-activity relationship for 12 ingenane-type diterpenoids in colorectal cancer Colo205 cells were preliminary studied. Significant anti-proliferation activities were observed in human melanoma cells breast cancer MDA-MB-435 cells and Colo205 cells. More than half of the isolated ingenane-type diterpenoids showed inhibitory activities in MDA-MB-435 cells. Eight ingenane- and one jatrophane-type diterpenoids possessed much lower IC 50 values in MDA-MB-435 cells than positive control staurosporine. Preliminary structure-activity relationship analysis showed that substituent on position 20 was important for the activity of ingenane-type diterpenoids in Colo205 cells and substituent on position 3 contributed more significant biological activity of the compounds than that on position 5 in both MDA-MB-435 and Colo205 cells. Copyright © 2017 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  20. Extracts of Euphorbia hirta Linn. (Euphorbiaceae) and Rauvolfia vomitoria Afzel (Apocynaceae) demonstrate activities against Onchocerca volvulus microfilariae in vitro.

    Science.gov (United States)

    Attah, Simon K; Ayeh-Kumi, Patrick F; Sittie, Archibald A; Oppong, Isaac V; Nyarko, Alexander K

    2013-03-18

    Onchocerciasis transmitted by Onchocerca volvulus is the second major cause of blindness in the world and it impacts negatively on the socio-economic development of the communities affected. Currently, ivermectin, a microfilaricidal drug is the only drug recommended for treating this disease. There have been speculations, of late, concerning O. volvulus resistance to ivermectin. Owing to this, it has become imperative to search for new drugs. World-wide, ethnomedicines including extracts of Euphorbia hirta and Rauvolfia vomitoria are used for treating various diseases, both infectious and non-infectious. In this study extracts of the two plants were evaluated in vitro in order to determine their effect against O. volvulus microfilariae. The toxicity of the E. hirta extracts on monkey kidney cell (LLCMK2) lines was also determined. The investigations showed that extracts of both plants immobilised microfilariae at different levels in vitro and, therefore, possess antifilarial properties. It was found that all the E. hirta extracts with the exception of the hexane extracts were more effective than those of R. vomitoria. Among the extracts of E. hirta the ethyl acetate fraction was most effective, and comparable to that of dimethanesulphonate salt but higher than that of Melarsoprol (Mel B). However, the crude ethanolic extract of E. hirta was found to be the least toxic to the LLCMK2 compared to the fractionated forms. Extracts from both plants possess antifilarial properties; however, the crude extract of E. hirta was found to be least toxic to LLCMK2.

  1. Euphorbia tirucalli L.-comprehensive characterization of a drought tolerant plant with a potential as biofuel source.

    Directory of Open Access Journals (Sweden)

    Bernadetta Rina Hastilestari

    Full Text Available Of late, decrease in mineral oil supplies has stimulated research on use of biomass as an alternative energy source. Climate change has brought problems such as increased drought and erratic rains. This, together with a rise in land degeneration problems with concomitant loss in soil fertility has inspired the scientific world to look for alternative bio-energy species. Euphorbia tirucalli L., a tree with C3/CAM metabolism in leaves/stem, can be cultivated on marginal, arid land and could be a good alternative source of biofuel. We analyzed a broad variety of E. tirucalli plants collected from different countries for their genetic diversity using AFLP. Physiological responses to induced drought stress were determined in a number of genotypes by monitoring growth parameters and influence on photosynthesis. For future breeding of economically interesting genotypes, rubber content and biogas production were quantified. Cluster analysis shows that the studied genotypes are divided into two groups, African and mostly non-African genotypes. Different genotypes respond significantly different to various levels of water. Malate measurement indicates that there is induction of CAM in leaves following drought stress. Rubber content varies strongly between genotypes. An investigation of the biogas production capacities of six E. tirucalli genotypes reveals biogas yields higher than from rapeseed but lower than maize silage.

  2. Estudo botânico, fitoquímico e fisico-químico de Euphorbia hirta L. (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    M.V. Pinto

    2014-01-01

    Full Text Available Euphorbia hirta L., popularmente conhecida por erva andorinha, tem sido utilizada no tratamento de distúrbios respiratórios e como antiespasmódico. Esse trabalho foi realizado com a finalidade de determinar as características macroscópicas e microscópicas das folhas, caule e raiz dessa planta, uma vez que estas são as partes usadas popularmente. Algumas características de valor na sua diagnose foram apontadas e ilustradas por fotomicrografias. Reações de fitoquímica e a determinação do conteúdo de água e de cinzas foram realizadas no pó obtido da planta inteira, parte essa utilizada na fitoterapia Ayuverda. Na prospecção fitoquímica foram encontrados flavonóides, mucilagem, resinas e cumarinas. Na determinação do teor de água, de cinzas totais e de cinzas insolúveis em ácido, os valores encontrados foram 8,99%, 9,35%, 0,75%, respectivamente. Com o desenvolvimento deste trabalho foi possível obter parâmetros para o controle de qualidade das folhas, caule e raízes de E. hirta.

  3. Action of Chitosan Against Xanthomonas Pathogenic Bacteria Isolated from Euphorbia pulcherrima

    Directory of Open Access Journals (Sweden)

    Yanli Wang

    2012-06-01

    Full Text Available The antibacterial activity and mechanism of two kinds of chitosan were investigated against twelve Xanthomonas strains recovered from Euphorbia pulcherrima. Results indicated that both chitosans markedly inhibited bacterial growth based on OD loss. Furthermore, the release of DNA and RNA from three selected strains was increased by both chitosans. However, the release of intracellular proteins was inhibited by both chitosans at different concentration and incubation times, except chitosan A at 0.1 mg/mL for 0.5 h incubation and 0.2 mg/mL for 2.0 h incubation increased the release of proteins, indicating the complexity of the interaction and cell membranes, which was affected by incubation time, bacterial species, chitosan type and concentration. Transmission electron microscopic observations revealed that chitosan caused changes in protoplast concentration and surface morphology. In some cells, the membranes and walls were badly distorted and disrupted, while other cells were enveloped by a thick and compact ribbon-like layer. The contrary influence on cell morphology may explain the differential effect in the release of material. In addition, scanning electron microscope and biofilm formation test revealed that both chitosans removed biofilm biomass. Overall, this study showed that membrane and biofilm play an important role in the antibacterial mechanism of chitosan.

  4. Pilot Scale Production of Irradiated Natural Rubber Latex and its Dipping Products

    Directory of Open Access Journals (Sweden)

    M. Utama

    2005-07-01

    Full Text Available One hundred and fifty kg natural rubber latex (NRL before and after concentration were added with 3 phr (part hundred ratio of rubber normal butyl acrylate, then the mixture were irradiated at 25 kGy by gamma rays of 60Co in pilot scale. The irradiated natural rubber latex (INRL were then being to use for producing rubber products such as condom, surgical gloves, and spygmomanometer in factory scale. The quality of INRL and rubber products such as : total solid content (TSC, dry rubber content (DRC, KOH, VFA and MST number, tensile strength, modulus, elongation at break, extractable protein content, and response against Type I allergy etc. were evaluated. The economic aspect for producing INRL by means of Gamma Irradiator (GI and Electron Beam Machine (EBM such as payback period (PP, net present value (NPV and internal rate return (IRR were calculated. The results showed that the latex properties of INRL such as DRC, TSC, KOH, VFA, and MST number are not only found to the requirement of the ISO 2004 standard but also the latex has low protein, lipid, and carbohydrate content. The physical and mechanical properties (tensile strength, modulus, and elongation at break of rubber dipping products such as condom, gloves, and sphygmomanometer are not only found to the requirement of ISO 4074, ISO 10282, and ANSI/AAMI SP-1994 standards, but also the allergic response tested clinical latex-sensitive protein allergen by ELISA test on gloves, and by SPT test on condom are found to be negative. It indicates that production of INRL or PVNRL or RVNRL by EBM 250 keV/10 mA, was more cheap than by using gamma γ irradiator 200 kCi, or sulfur vulcanization. The value of PBP (payback period was 2,1 years, NPV (net present value was 4,250 US $, PI (profitability index 1,06 and IRR (internal rate of returns was 25,0%.

  5. Eficácia de herbicidas em diferentes quantidades de palha de cana-de-açúcar no controle de Euphorbia heterophylla Efficacy of herbicides in different amounts of sugar cane straw on Euphorbia heterophylla control

    Directory of Open Access Journals (Sweden)

    P.A. Monquero

    2007-09-01

    Full Text Available Este trabalho foi realizado com o objetivo de estudar o efeito de diferentes quantidades de palha de cana-de-açúcar, colhida sem queima prévia do canavial, sobre a eficácia de alguns herbicidas recomendados para esta cultura. O experimento foi conduzido em campo no Centro de Ciências Agrárias/UFSCar, em Araras, SP. Os tratamentos consistiram dos herbicidas trifloxysulfuron-sodium + ametryn (1.463 + 37 g i.a ha-1, imazapic (84 g i.a ha-1, imazapyr (200 g i.a ha-1, ¹diuron + hexazinone (1.170 + 330 g i.a ha-1 e ²diuron + hexazinone (1.330 + 160 g i.a ha-1 aplicados em pré-emergência de Euphorbia heterophylla e sobre cinco quantidades de palha de cana-de-açúcar (0, 5, 10, 15 e 20 t ha-1. A eficácia de controle das plantas daninhas foi avaliada aos 7, 14, 21 e 28 dias após a aplicação dos tratamentos (DAT. A palha (15 e 20 t ha-1 reduziu a população de E. heterophylla. À medida que se aumentou a quantidade de palha, houve redução na eficácia dos herbicidas; com 15 t ha-1 de palha, o controle foi considerado satisfatório (90% apenas para os tratamentos ¹diuron + hexazinone e trifloxysulfuron-sodium + ametryn. Com 20 t ha-1, nenhum herbicida foi eficaz; entretanto, a palha foi eficiente na supressão dessa espécie, verificando-se que o número de plantas emergidas foi menor mesmo na testemunha.This work aimed to study the effect of different amounts of sugar cane straw, collected unburned, on the efficacy of some herbicides recommended for this culture. The experiment was carried out in the field, at the Centro de Ciências Agrárias/UFSCar, Araras, SP. The treatments consisted of herbicides trifloxysulfuron-sodium + ametryn (1,463 + 37 g a.i ha-1, imazapic (84 g a.i ha-1, imazapyr (200 g a.i ha-1, diuron + hexazinone (1,170 + 330 g a.i ha ¹ and ²diuron + hexazinone (1,330 + 160 g a.i ha-1 applied in pre emergence of Euphorbia heterophylla and five increasing amounts of sugar cane straw ( 0, 5, 10, 15 and 20 t ha-1.Weed

  6. Aplicações isoladas ou associadas de diuron, oxyfluorfen e prometryne para o controle de Euphorbia heterophylla Isolated or combined application of diuron, oxyfluorfen and prometryn for Euphorbia heterophylla control

    Directory of Open Access Journals (Sweden)

    R.S Oliveira JR

    2011-09-01

    Full Text Available A aplicação em pré-emergência no início do ciclo do algodoeiro é prática consagrada entre os produtores. Embora os herbicidas diuron, oxyfluorfen e prometryne sejam opções para uso nessa cultura, há informações limitadas referentes à eficácia desses herbicidas no controle de Euphorbia heterophylla. O objetivo do presente trabalho foi determinar a curva de dose-resposta de diuron, oxyfluorfen e prometryne para o controle de E. heterophylla, bem como analisar a eficiência biológica de misturas desses herbicidas no manejo dessa espécie. O trabalho foi composto por seis experimentos conduzidos simultaneamente em casa de vegetação, sendo três deles com doses crescentes de cada herbicida aplicado isoladamente e três compostos por misturas dos herbicidas dois a dois. A curva de dose-resposta foi ajustada para os dados das avaliações de porcentagem de redução de massa seca aos 28 dias após a aplicação. Determinoaram-se as doses I80 e I95, que correspondem ao controle de 80% e 95%, respectivamente, de controle visual ou redução da massa seca. Diuron, oxyfluorfen e prometryne, aplicados isoladamente, mostraram-se eficientes, dentro do intervalo de doses utilizado, no controle de E. heterophylla. As misturas contendo oxyfluorfen apresentaram-se, de modo geral, como aditivas ou antagonísticas, ao passo que misturas de diuron+prometryne foram aditivas ou sinergísticas. Das três combinações de produtos possíveis, oxyfluorfen+prometryne foi a associação que resultou em menor número de tratamentos que promoveram controle aceitável do leiteiro.Pre-emergence herbicide application at the beginning of the crop cycle is a consecrated practice among cotton farmers. Although herbicides, such as diuron, oxyfluorfen and prometryn, are options for this crop, not much is known about their effect on Euphorbia heterophylla. This work aimed to elaborate dose-response curves for diuron, oxyfluorfen and prometryn in relation to E

  7. First record of the behavior of latex drainage by Trigona spinipes (Fabricius (Hymenoptera, Apidae in laticiferous flowers

    Directory of Open Access Journals (Sweden)

    Cristiana Koschnitzke

    2011-09-01

    Full Text Available This paper describes the behavior of the bee Trigona spinipes, to avoid the latex, when piercing the base of the tubular corolla of the flowers of Mandevilla guanabarica in order to steal the nectar.

  8. Biodegradability and aging study of rubber films obtained by gamma radiation vulcanization processes of latex; Estudo da biodegradabilidade e envelhecimento de filmes de borracha obtidos por processos de vulcanizacao do latex por radiacao induzida de fonte gama

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Carlos Felipe Pinto

    2005-07-01

    The natural rubber latex (NRL) is industrially crosslinked by the conventional process of vulcanization, which uses sulphur and heat. Otherwise, the network can also be done by the alternative process with ionizing radiation. In this work the crosslinking of NRL was studied by the comparison of the conventional vulcanization system and the ionizing radiation process of {sup 60}C source. The products obtained, the irradiated latex, the irradiated latex with approximately 1% of soy lecithin and the sulphur vulcanized latex were tested by accelerated aging with ultraviolet (UV) and outdoor aging with compostage, tensile strength at break, swelling and gel fraction, fungi micro biota, scanning electron microscopy (SEM), infrared spectroscopy (FTIR) and thermogravimetry and differential scanning calorimetry analysis (TG and DSC). The results showed that the aging with microorganisms have a great influence in the physical properties of the samples. The thermal stability order observed showed that the sulphur vulcanized latex is more resistant, what is probably associated to a network more stable under the aging conditions. On the other hand, the irradiated latex showed intense biodegradation aspects, particularly with the presence of the soy lecithin. (author)

  9. Avaliação de cultivares de soja (Glycine max (L. Merril em competição com Euphorbia heterophylla L. sob três densidades e dois períodos de ocorrência Evaluation of soybean (Glycine max (L. Merrill cultivars in competition with Euphorbia heterophylla L. in three densities and two periods of occurrence

    Directory of Open Access Journals (Sweden)

    V. M. Chemale

    1982-12-01

    Full Text Available O presente trabalho, conduzido durante o ano agrícola de 1979/80 na Estação Experimental Agronômica de UFRGS, em Guaíba, RS, apresentou como objetivo testar quatro cultivares de soja (Paraná, Prata, Hood e IAS-4 quanto à sua habilidade em concorrer com Euphorbia heterophylla L. (leiteira, amendoim-bravo estabelecida em três densidades (0, 12 e 54 plan-tas/m2, em média e dois períodos de duração da competição (45 e 115 dias após a emergência da soja. Constatou-se que houve redução no rendimento de grãos de soja por efeito dos dois períodos de competição e das densidades de E. heterophylla L. referidas. Também os números de grãos e de legumes por área foram consideravelmente reduzidos pela presença da planta daninha associada ao período mais prolongado de competição. A espessura do caule e o número de nós das plantas de soja decresceram apenas sob o efeito da maior densidade da Euphorbia; entretanto, o número de ramos e o índice de área foliar, este aos 75 dias após a emergência da cultura, sofreram redução com a infestação de 12 plantas de Euphorbia por m2.A field experiment was performed at the Agronomy Experimental Station of UFRGS, in Guaíba, RS, Brazil, during the 1979/80 growing season, in order to test four soybean cultivars (Paraná, Prata, Hood e IAS-4 in competition with Euphorbia heterophylla L. established in three densities (0, 12 and 54 plants/m2 during two periods (45 and 115 days after soybean emergence. It was observed that soybean cultivars presented reduction of seed yields under the effect of the pe riods of competition and densities of Euphorbia heterophylla L. The number of seeds and pods per area were considerably reduced in the presence of the weed associated with the longest competition period. The stem diameter and number of nodes were reduced only by competition of the highest Euphorbia density; however, the number of branches and leaf area index, this after a period of 75 days

  10. Euphorbia denticulata Lam.: A promising source of phyto-pharmaceuticals for the development of novel functional formulations.

    Science.gov (United States)

    Zengin, Gokhan; Uysal, Ahmet; Aktumsek, Abdurrahman; Mocan, Andrei; Mollica, Adriano; Locatelli, Marcello; Custodio, Luisa; Neng, Nuno R; Nogueira, José M F; Aumeeruddy-Elalfi, Zaahira; Mahomoodally, M Fawzi

    2017-03-01

    In this study, Methanolic extracts of Euphorbia denticulata parts (flowers, leaf, stem, and mix of aerial parts) were assessed for a panoply of bioactivities. Inhibitory potential against key enzymes involved in diabetes (α-glucosidase and α-amylase), obesity (pancreatic lipase), neurodegenerative diseases (cholinesterases), and hyperpigmentation (tyrosinase) was evaluated. The antioxidant and antibacterial properties were also assessed. The total phenolic, flavonoid, and phytochemical profile were established using HPLC/DAD and molecular modelling studies on specific target compounds were performed in silico. The flower extract was found to be rich in phenolics and flavonoids, (60.11±1.40mgGAE/g and 42.04±0.16mgRE/g respectively), which tend to correlate with the high radical scavenging activity of this extract (120.34±3.33mgTE/g and 165.42±2.16mgTE/g for DPPH and ABTS respectively). Catechin, epicatechin, gallic acid, p-OH-Benzoic acid, rosmarinic acid, and epigallocatechin gallate, found in significant abundance in the extracts were assessed using molecular modelling with the aim to study their docking properties on a set of six enzymes used in this study. The extracts were moderately effective with MIC values ranging between 1.56 to 6.25mg/ml, but potent growth inhibitors of MRSA strains. Results amassed herein can be used as a stimulus for further studies geared towards the development of novel phyto-pharmaceuticals. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  11. Prevalence of manufacturing defects in latex examination gloves used in selected dental practices in central Saudi Arabia.

    Science.gov (United States)

    Al-Swuailem, Abdullah S

    2014-07-01

    To assess the defect rates in latex examination gloves used in selected dental practices in Riyadh, Saudi Arabia. In this cross-sectional study, a total of 796 latex examination gloves were collected from 5 governmental hospitals and 5 private dental practices between April 2012 and May 2012. The gloves were assessed for presence of defects visually (VT) and using water inflation test (WIT). One and 2 sample t-tests were used to assess significant differences in defect rates among each latex brand, and between governmental hospitals and private dental practices. Defects in latex gloves were more likely to be identified using WIT compared with VT (20.2% versus 4.3%, p=0.000). Using WIT, examined latex gloves had a defect rate approximately 8 times the acceptable quality level of 2.5% (20.2%, p=0.000). Using WIT, gloves used in private dental practices had significantly higher defect rates compared with governmental dental clinics (25.6% versus 14.6%, p=0.006). Most latex examination gloves used in the sampled governmental dental clinics and private dental practices in Riyadh had significantly higher preexisting defect rates than acceptable standard levels.

  12. Frequent IgE sensitization to latex, cow's milk, and egg in children with short bowel syndrome.

    Science.gov (United States)

    Mazon, Angel; Solera, Eva; Alentado, Noemi; Oliver, Fernando; Pamies, Rafael; Caballero, Luis; Nieto, Antonio; Dalmau, Jaime

    2008-03-01

    Children with short bowel syndrome (SBS) undergo frequent operations, so they are at risk for sensitizing to latex. There have been isolated reports of sensitization to food in these children. In a cross-sectional study, we assessed sensitization to latex, cow's milk, and egg with skin prick tests (SPT) and serum-specific immunoglobulin E (IgE) in 14 children with SBS. Data were collected about the number of operations with latex devices, serum total IgE, and history of feeding with milk formula. Ten children were sensitized to latex (specific IgE median: 6.7 kU/l, range: 0.5-33). Compared with those non-sensitized, sensitized children had significantly (p range: 0.5-21.1 kU/l), and five to egg (specific IgE median: 0.68, range: 0.58-2.17 kU/l). Except for some isolated days with cow's milk formula, the children had been initially fed with a diet without intact cow's milk proteins. Sensitization to latex, cow's milk, and egg is very frequent in children with SBS. They should be treated in a latex-free environment since the very early stages of the disease, and should be routinely studied regarding food sensitization, as this might contribute as an added factor in the chronic diarrhea of these patients.

  13. Radiation-induced grafting polymerization of MMA onto polybutadiene rubber latex

    International Nuclear Information System (INIS)

    Peng Jing; Wang Maolin; Qiao Jinliang; Wei Genshuan

    2005-01-01

    The grafting of methyl methacrylate (MMA) onto polybutadiene rubber latex by the direct radiation method was carried out. The effects of monomer concentration, absorbed dose and dose rate of gamma rays on the grafting yield were investigated. The graft copolymers were characterized by transmission electron microscopy (TEM), FTIR spectroscopy, and differential scanning calorimetry. TEM photographs revealed that the core-shell structures of latex particles are formed at low MMA content, and with the increasing of MMA content, the semi-IPN-like structure with core-shell could be developed due to the high gel fraction of polybutadiene (PBD) seed particles. In addition, infrared analysis confirmed that MMA could be grafted onto PBD molecular chains effectively under appropriate irradiation conditions. The interfacial adhesion between PBD rubber (core) and PMMA (shell) phases could be enhanced with the increase of MMA concentration

  14. EVALUATION OF CYTOTOXIC, ANTIMICROBIAL AND ANTIINFLAMMATORY PROPERTIES FROM THE LATEX OF IPOMEA STAPHYLINA

    Directory of Open Access Journals (Sweden)

    Prasanthi Narra

    2014-04-01

    Full Text Available The plant Ipomoea staphylina has been used in diverse traditional medication for the treatment of diseases and illness of human beings. The crude latex extract obtained from the stem of Ipomea staphylina was evaluated for cytotoxic, antimicrobial and wound healing properties. Cell viability and cytotoxicity assays such as Colony Formation method and Enzyme based methods that determined cell viability with a colorimetric method were performed to evaluate the medicinal properties of Ipomea staphylina. Similarly Microbiological Antibiotic Assay to determine the antimicrobial properties and wound healing properties were tested by determining the potent anti-inflammatory molecules that inhibited COX and LOX enzymes. Results showed that the latex crude extract of Ipomea staphylina showed potent Antimicrobial and Antiinflamatory properties, but the viability of the cells were unaffected.

  15. Tensile properties of latex paint films with TiO2 pigment

    Science.gov (United States)

    Hagan, Eric W. S.; Charalambides, Maria N.; Young, Christina T.; Learner, Thomas J. S.; Hackney, Stephen

    2009-05-01

    The tensile properties of latex paint films containing TiO2 pigment were studied with respect to temperature, strain-rate and moisture content. The purpose of performing these experiments was to assist museums in defining safe conditions for modern paintings held in collections. The glass transition temperature of latex paint binders is in close proximity to ambient temperature, resulting in high strain-rate dependence in typical exposure environments. Time dependence of modulus and failure strain is discussed in the context of time-temperature superposition, which was used to extend the experimental time scale. Nonlinear viscoelastic material models are also presented, which incorporate a Prony series with the Ogden or Neo-Hookean hyperelastic function for different TiO2 concentrations.

  16. n-BA/KOH/t-BHP behaviour in the natural rubber latex vulcanization by gamma rays

    International Nuclear Information System (INIS)

    Souza, A. de.

    1994-01-01

    Natural rubber latex was vulcanized in the absence and in the presence of sensitizer (S), with gamma ray from 60 Co source, panoramic type, at the dose rate range of 1,20-1,33 kGy/h. The components of used S were n-butyl acrylate (n-BA), the KOH as stabilizer and t-butyl hydroperoxide (t-BHP) as co-S. The purpose of this work was to study the efficiency and the behaviour of each component of S in the irradiated latex crosslinking by tensile strength (T b ), volume fraction and permanent set. In the absence of S occur straight crosslinking between macromolecular adjacent radicals. IN the presence of S, the n-BA participates in the crosslinking through acrylic bridges between macromolecules. (author)

  17. The effect of proteins on the aging properties of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Abad, L.V.

    1993-01-01

    The effect of natural rubber latex (NRL) proteins on the aging properties of NRL films was investigated. SDS-PAGE electrophoresis of the rubber proteins in NRL (Sri-Lanka) indicated a total of 18 proteins. A sharp decrease in tensile strength was observed after aging when NRL films were leached in 1% NH 4 OH. However, when these films were soaked in ethanol prior to leaching, the aging properties approximated those of the unleashed samples. Electrophoretic analysis of the proteins present in the NH 3 extracts of leached RVNRL films showed a high concentration of the protein herein. This protein was not found in the NH 3 extracts of ethanol soaked films. NRL proteins were shown to decelerate the aging process of Radiation Vulcanized Natural Rubber Latex (RVNRL) films. Among the proteins, herein exhibited good anti-aging properties. The hydrolyzates from NR proteins also enhanced considerably the aging properties of RVNRL. (auth.). 8 refs.; 40 figs.; 30 tabs

  18. texreg: Conversion of Statistical Model Output in R to LATEX and HTML Tables

    Directory of Open Access Journals (Sweden)

    Philip Leifeld

    2013-11-01

    Full Text Available A recurrent task in applied statistics is the (mostly manual preparation of model output for inclusion in LATEX, Microsoft Word, or HTML documents usually with more than one model presented in a single table along with several goodness-of-fit statistics. However, statistical models in R have diverse object structures and summary methods, which makes this process cumbersome. This article first develops a set of guidelines for converting statistical model output to LATEX and HTML tables, then assesses to what extent existing packages meet these requirements, and finally presents the texreg package as a solution that meets all of the criteria set out in the beginning. After providing various usage examples, a blueprint for writing custom model extensions is proposed.

  19. Gloves against mineral oils and mechanical hazards: composites of carboxylated acrylonitrile-butadiene rubber latex.

    Science.gov (United States)

    Krzemińska, Sylwia; Rzymski, Władysław M; Malesa, Monika; Borkowska, Urszula; Oleksy, Mariusz

    2016-09-01

    Resistance to permeation of noxious chemical substances should be accompanied by resistance to mechanical factors because the glove material may be torn, cut or punctured in the workplace. This study reports on glove materials, protecting against mineral oils and mechanical hazards, made of carboxylated acrylonitrile-butadiene rubber (XNBR) latex. The obtained materials were characterized by a very high resistance of the produced materials to oil permeation (breakthrough time > 480 min). The mechanical properties, and especially tear resistance, of the studied materials were improved after the addition of modified bentonite (nanofiller) to the XNBR latex mixture. The nanocomposite meets the requirements in terms of parameters characterizing tear, abrasion, cut and puncture resistance. Therefore, the developed material may be used for the production of multifunctional protective gloves.

  20. Gloves against mineral oils and mechanical hazards: composites of carboxylated acrylonitrile–butadiene rubber latex

    Science.gov (United States)

    Krzemińska, Sylwia; Rzymski, Władysław M.; Malesa, Monika; Borkowska, Urszula; Oleksy, Mariusz

    2016-01-01

    Resistance to permeation of noxious chemical substances should be accompanied by resistance to mechanical factors because the glove material may be torn, cut or punctured in the workplace. This study reports on glove materials, protecting against mineral oils and mechanical hazards, made of carboxylated acrylonitrile–butadiene rubber (XNBR) latex. The obtained materials were characterized by a very high resistance of the produced materials to oil permeation (breakthrough time > 480 min). The mechanical properties, and especially tear resistance, of the studied materials were improved after the addition of modified bentonite (nanofiller) to the XNBR latex mixture. The nanocomposite meets the requirements in terms of parameters characterizing tear, abrasion, cut and puncture resistance. Therefore, the developed material may be used for the production of multifunctional protective gloves. PMID:26757889

  1. The role of proteins on the thermal oxidative aging of radiation vulcanized natural rubber latex

    International Nuclear Information System (INIS)

    Abad, L.V.; Rosa, A. de la; Keizo Makuuchi; Fumio Yoshii

    1996-01-01

    The effect of Hevea latex proteins on the aging properties of radiation vulcanized natural rubber latex (RVNRL) was investigated. Unpurified RVNRL films exhibited better aging properties than the purified RVNRL films. A sharp decrease in tensile strength was observed after aging when RVNRL films were leached in 1% NH sub 4 OH. However, when these films were soaked in ethanol prior to leaching, the aging properties approximated those of the unleached samples. Kjeldahl and FT-IR analyses of the leached and unleached RVNRL films indicated a higher protein content for both the unleached and ethanol-soaked films than for leached films. Electrophoretic analysis of the proteins present in the NH, extracts of leached RVNRL films showed a high concentration of hevein. This protein was not found in the ATH, extracts of ethanol soaked films. Hevein was shown to improve the aging properties of RVNRL

  2. An Ingenol Derived from Euphorbia kansui Induces Hepatocyte Cytotoxicity by Triggering G0/G1 Cell Cycle Arrest and Regulating the Mitochondrial Apoptosis Pathway in Vitro

    Directory of Open Access Journals (Sweden)

    Xiaojing Yan

    2016-06-01

    Full Text Available Natural product lingenol, a purified diterpenoid compound derived from the root of Euphorbia kansui, exerts serious hepatotoxicity; however, the molecular mechanisms remain to be defined. In the present study, cell counting Kit-8 (CCK-8, inverted phase contrast microscope and flow cytometry were used to demonstrate that lingenol significantly inhibited L-O2 cells proliferation, and induced cell cycle arrest and apoptosis. Moreover, the results investigated that lingenol markedly disrupted mitochondrial functions by high content screening (HCS. In addition, the up-regulation of cytochrome c, AIF and Apaf-1 and activation of caspases were found in L-O2 cells detected by Western blotting and ELISA assay, which was required for lingenol activation of cytochrome c-mediated caspase cascades and AIF-mediated DNA damage. Mechanistic investigations revealed that lingenol significantly down-regulated the Bcl-2/Bax ratio and enhanced the reactive oxygen species (ROS in L-O2 cells. These data collectively indicated that lingenol modulation of ROS and Bcl-2/Bax ratio led to cell cycle arrest and mitochondrial-mediated apoptosis in L-O2 cells in vitro. All of these results will be helpful to reveal the hepatotoxicity mechanism of Euphorbia kansui and to effectively guide safer and better clinical application of this herb.

  3. Obtusifoliol related steroids from Euphorbia sogdiana with cell growth inhibitory activity and apoptotic effects on breast cancer cells (MCF-7 and MDA-MB231).

    Science.gov (United States)

    Aghaei, Mahmoud; Yazdiniapour, Zeinab; Ghanadian, Mustafa; Zolfaghari, Behzad; Lanzotti, Virginia; Mirsafaee, Vahid

    2016-11-01

    From the aerial parts of Euphorbia sogdiana Popov, obtusifoliol (1) and two related steroids (2-3) have been isolated and characterized along with a known cycloartane derivative (4). The chemical structure of the obtusifoliol-related compounds, obtained by 1D and 2D NMR, and MS measurements, have been determined as: 3β,7α-dihydroxy-4α,14α-dimethyl-5α-ergosta-8,24(28)-diene-11-one (2) and 3β-hydroxy-4α,14α-dimethyl-5α-ergosta-8,24(28)-diene-1-one (3). Compound 2 has been previously isolated from Euphorbia chamaesyce while compound 3 was never reported before. The isolated compounds 1-4 were subjected to cytotoxic tests on the breast cancer cells, MCF-7 and MDA-MB231. Further pharmacological tests on the more active compounds 2 and 3 indicated their action to be related to cell growth inhibitory activity and apoptotic effects on the tested cells. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Molecular characterization and prevalence of two capulaviruses: Alfalfa leaf curl virus from France and Euphorbia caput-medusae latent virus from South Africa.

    Science.gov (United States)

    Bernardo, Pauline; Muhire, Brejnev; François, Sarah; Deshoux, Maëlle; Hartnady, Penelope; Farkas, Kata; Kraberger, Simona; Filloux, Denis; Fernandez, Emmanuel; Galzi, Serge; Ferdinand, Romain; Granier, Martine; Marais, Armelle; Monge Blasco, Pablo; Candresse, Thierry; Escriu, Fernando; Varsani, Arvind; Harkins, Gordon W; Martin, Darren P; Roumagnac, Philippe

    2016-06-01

    Little is known about the prevalence, diversity, evolutionary processes, genomic structures and population dynamics of viruses in the divergent geminivirus lineage known as the capulaviruses. We determined and analyzed full genome sequences of 13 Euphorbia caput-medusae latent virus (EcmLV) and 26 Alfalfa leaf curl virus (ALCV) isolates, and partial genome sequences of 23 EcmLV and 37 ALCV isolates. While EcmLV was asymptomatic in uncultivated southern African Euphorbia caput-medusae, severe alfalfa disease symptoms were associated with ALCV in southern France. The prevalence of both viruses exceeded 10% in their respective hosts. Besides using patterns of detectable negative selection to identify ORFs that are probably functionally expressed, we show that ALCV and EcmLV both display evidence of inter-species recombination and biologically functional genomic secondary structures. Finally, we show that whereas the EcmLV populations likely experience restricted geographical dispersion, ALCV is probably freely moving across the French Mediterranean region. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Development of a Matrix Solid-Phase Dispersion Extraction Combined with UPLC/Q-TOF-MS for Determination of Phenolics and Terpenoids from the Euphorbia fischeriana.

    Science.gov (United States)

    Li, Wenjing; Lin, Yu; Wang, Yuchun; Hong, Bo

    2017-09-11

    A method based on a simplified extraction by matrix solid phase dispersion (MSPD) followed by ultra-performance liquid chromatography coupled with the quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS) determination is validated for analysis of two phenolics and three terpenoids in Euphorbia fischeriana . The optimized experimental parameters of MSPD including dispersing sorbent (silica gel), ratio of sample to dispersing sorbent (1:2), elution solvent (water-ethanol: 30-70) and volume of the elution solvent (10 mL) were examined and set down. The highest extraction yields of chromatogram information and the five compounds were obtained under the optimized conditions. A total of 25 constituents have been identified and five components have been quantified from Euphorbia fischeriana . A linear relationship (r² ≥ 0.9964) between the concentrations and the peak areas of the mixed standard substances were revealed. The average recovery was between 92.4% and 103.2% with RSD values less than 3.45% ( n = 5). The extraction yields of two phenolics and three terpenoids obtained by the MSPD were higher than those of traditional reflux and sonication extraction with reduced requirement on sample, solvent and time. In addition, the optimized method will be applied for analyzing terpenoids in other Chinese herbal medicine samples.

  6. Numerical Simulation and Experimental Validation of the Inflation Test of Latex Balloons

    Directory of Open Access Journals (Sweden)

    Claudio Bustos

    Full Text Available Abstract Experiments and modeling aimed at assessing the mechanical response of latex balloons in the inflation test are presented. To this end, the hyperelastic Yeoh material model is firstly characterized via tensile test and, then, used to numerically simulate via finite elements the stress-strain evolution during the inflation test. The numerical pressure-displacement curves are validated with those obtained experimentally. Moreover, this analysis is extended to a biomedical problem of an eyeball under glaucoma conditions.

  7. Study on grafting of monomer onto natural rubber latex by radiation technique

    International Nuclear Information System (INIS)

    Nguyen Tan Man; Le Hai; Tran Thi Tam; Le Huu Tu, Pham Thi Sam; Dao Minh Phuong; Ha Thuc Huy

    2004-01-01

    Radiation vulcanization of natural rubber latex has been extensively developed through programmers assisted by the IAEA and UNDP under RCA in Asia and Pacific Region. R-D has been done in most of the Member States with technical assistance from Japan's Takasaki Radiation Chemistry Establishment. Radiation vulcanized natural rubber latex (RVNRL) has many advantages over the conventional sulfur vulcanized latex, such as absence of nitrosamine and low cytotoxicity. Radiation crosslinking is a room temperature process, itself an important cost advantage, it is easily controlled and desired extend of crosslinking is easily achieved by controlling the dose (irradiation time). Disadvantages of RVNRL to be improved are poor physical properties of film such as low tensile strength and tear strength. The research groups of Japan, Thailand and Indonesia concentrated on the improvement of physical properties of RVNRL using radiation grafted PMMA as additive [2]. F. Sundardi and W. Sofiarti have reported that tensile strength and hardness increased by radiation grafting of styrene onto NR [5]. Ono et al have reported the grafting of MMA onto NR by gamma irradiation at a dose of 5 kGy for producing thermoplastic elastomers [4]. The objective of this project is to report the results of studies of radiation graft-copolymerization of methyl methacrylate (MMA) or styrene (St) onto natural rubber latex in order to improve their physico-mechanical properties and evaluation of grafted material using Small-Angle Neutron Scattering through FNCA Project. The grafting degree of MMA and St onto NR increased with the increase of irradiation dose and monomer concentration. The alteration of grafted products structure was determined by IR method. Tensile strength, Shore A hardness, 100% modulus of grafted products increased with the increase of monomer concentration and irradiation dose while elongation at break decreased. The grafted products were characterized by Transmission Electron

  8. Numerical Simulation and Experimental Validation of the Inflation Test of Latex Balloons

    OpenAIRE

    Bustos, Claudio; Herrera, Claudio García; Celentano, Diego; Chen, Daming; Cruchaga, Marcela

    2016-01-01

    Abstract Experiments and modeling aimed at assessing the mechanical response of latex balloons in the inflation test are presented. To this end, the hyperelastic Yeoh material model is firstly characterized via tensile test and, then, used to numerically simulate via finite elements the stress-strain evolution during the inflation test. The numerical pressure-displacement curves are validated with those obtained experimentally. Moreover, this analysis is extended to a biomedical problem of an...

  9. The influence of temperature and reaction time in the degradation of natural rubber latex

    International Nuclear Information System (INIS)

    Siti Zaleha Isa; Rosiyah Yahya; Aziz Hassan; Mohd Tahir

    2007-01-01

    Liquid natural rubber (LNR /LENR) should be considered as a new material instead of a new type of rubber though they have the same configuration as the rubber used. In this work, thermal degradation of natural rubber latex was carried out to obtain LNR/LENR by varying the reaction time at different temperatures. The degraded polymers were characterized structurally using FTIR and NMR spectroscopies and the average molecular weights were determined by membrane-osmometry and viscometry. (author)

  10. Study on preparation of new antioxidants for radiation vulcanized natural rubber latex product. Antioxidant from keratin

    International Nuclear Information System (INIS)

    Nguyen Quoc Hien; Nguyen Van Toan; Vo Tan Thien; Le Hai

    2000-01-01

    The thermo-oxidative aging resistance of radiation vulcanization of natural rubber latex (RVNRL) products should be adequately by using suitable antioxidants or new kind of effective antioxidant. This work presents the results of preparation of natural antioxidant from hair keratin. Characteristics and effectiveness of resultant antioxidant are also presented. The results obtained indicates that antioxidant made from hair keratin is safe and effective for rubber products from RVNRL. (author)

  11. Comparison of the effect of using latex and nitrile gloves hand dexterity among Iranian population

    Directory of Open Access Journals (Sweden)

    T. Allahyari

    2014-02-01

    .Conclusion: Considering that there was no significant difference in the score of both fine finger and gross hand dexterity while using nitrile gloves as compared to the control condition (without gloves, means that use of nitrile gloves has no adverse effect on hand dexterity therefore, using nitrile gloves is recommended as a alternative for the latex gloves, considering the additional advantage of no allergic reaction in this gloves.

  12. Expression of VEGF and collagen using a latex biomembrane as bladder replacement in rabbits

    Directory of Open Access Journals (Sweden)

    André Luís Alonso Domingos

    2012-08-01

    Full Text Available OBJECTIVE: To investigate the VEGF expression and collagen deposition using a latex biomembrane as bladder replacement in rabbits. MATERIALS AND METHODS: After partial cystectomy, a patch of a non-vulcanized latex biomembrane (2 x 2 cm was sewn to the bladder of rabbits with 5/0 monofilament polydioxanone sulfate sutures in a watertight manner. Groups of 5 animals were killed at 15, 45 and 90 days after surgery and the bladder was removed. Sections of 5µm were cut and stained with picrosirius-red in order to estimate the amount of extracellular matrix in the graft. To confirm the presence of VEGF in tissues, protein expression was determined by immunohistochemistry. RESULTS: No death, urinary leakage or graft extrusion occurred in any group. All bladders showed a spherical shape. A progressive reduction in the amount of collagen occurred in the graft area and was negatively and linearly correlated with time (p < 0.001. VEGF expression was higher in grafted areas when compared to controls at 15 and 45 days after surgery and decreased with time (p < 0.001. CONCLUSION: The latex biomembrane as a matrix for partial bladder replacement in rabbits promotes temporary collagen deposition and stimulates the angiogenic process.

  13. Cytotoxicity Comparison of the Nanoparticles Deposited on Latex Rubber Bands between the Original and Stretched State

    Directory of Open Access Journals (Sweden)

    Jung-Hwan Lee

    2014-01-01

    Full Text Available Understanding the biocompatibility of nanoparticles in dental materials is essential for their safe usage in the oral cavity. In this study, we investigated whether nanoparticles deposited on orthodontic latex rubber bands are involved in the induction of cytotoxicity. A method of stretching to three times (“3L” the length of the latex rubber bands was employed to detach the particles using the original length (“L” for comparison. The cytotoxicity tests were performed on extracts with mouse fibroblasts (L929 and human gingival fibroblasts (HGFs. Fourier transform infrared spectroscopy, ion chromatography, elemental analysis, and inductively coupled plasma mass spectrometry (ICP-MS were performed to detect the harmful components in the extracts from rubber bands. There was a significant decrease in the cell viability in the “L” samples compared with the “3L” samples (P<0.05 in the L929 and HGF cells. This was due to the Ni single crystal nanoparticles (~50nm from the inner surface of “L” samples that were detached in the “3L” samples as well as the Zn ion (~9 ppm detected in the extract. This study revealed that the Ni nanoparticles, as well as Zn ions, were involved in the induction of cytotoxicity from the latex rubber bands.

  14. Sequence and expression analyses of ethylene response factors highly expressed in latex cells from Hevea brasiliensis.

    Directory of Open Access Journals (Sweden)

    Piyanuch Piyatrakul

    Full Text Available The AP2/ERF superfamily encodes transcription factors that play a key role in plant development and responses to abiotic and biotic stress. In Hevea brasiliensis, ERF genes have been identified by RNA sequencing. This study set out to validate the number of HbERF genes, and identify ERF genes involved in the regulation of latex cell metabolism. A comprehensive Hevea transcriptome was improved using additional RNA reads from reproductive tissues. Newly assembled contigs were annotated in the Gene Ontology database and were assigned to 3 main categories. The AP2/ERF superfamily is the third most represented compared with other transcription factor families. A comparison with genomic scaffolds led to an estimation of 114 AP2/ERF genes and 1 soloist in Hevea brasiliensis. Based on a phylogenetic analysis, functions were predicted for 26 HbERF genes. A relative transcript abundance analysis was performed by real-time RT-PCR in various tissues. Transcripts of ERFs from group I and VIII were very abundant in all tissues while those of group VII were highly accumulated in latex cells. Seven of the thirty-five ERF expression marker genes were highly expressed in latex. Subcellular localization and transactivation analyses suggested that HbERF-VII candidate genes encoded functional transcription factors.

  15. Latex-mediated synthesis of ZnS nanoparticles: green synthesis approach

    Energy Technology Data Exchange (ETDEWEB)

    Hudlikar, Manish; Joglekar, Shreeram [University of Pune, Division of Biochemistry, Department of Chemistry (India); Dhaygude, Mayur [National Chemical Laboratory, Polymer Science and Engineering Division (India); Kodam, Kisan, E-mail: kodam@chem.unipune.ac.in [University of Pune, Division of Biochemistry, Department of Chemistry (India)

    2012-05-15

    A low-cost, green synthesis of ZnS nanoparticles is reported using 0.3 % latex solution prepared from Jatropha curcas L. ZnS nanoparticles were characterized by X-ray diffraction, selected area electron diffraction, transmission electron microscopy, energy dispersive analysis of X-rays, UV-vis optical absorption and photoluminescence techniques. Fourier Transform Infrared Spectroscopy was performed to find the role of cyclic peptides namely curcacycline A (an octapeptide), curcacycline B (a nonapeptide) and curcain (an enzyme) as a possible reducing and stabilizing agents present in the latex of J. curcas L. The average size of ZnS nanoparticles was found to be 10 nm. Latex of J. curcas L. itself acts as a source of sulphide (S{sup -2}) ions that are donated to Zn ions under present experimental conditions. Source of sulphide (S{sup -2}) ions is still unclear, but we speculate that cysteine or thiol residues present in enzyme curcain may be donating these sulphide (S{sup -2}) ions.

  16. Latex-mediated synthesis of ZnS nanoparticles: green synthesis approach

    Science.gov (United States)

    Hudlikar, Manish; Joglekar, Shreeram; Dhaygude, Mayur; Kodam, Kisan

    2012-05-01

    A low-cost, green synthesis of ZnS nanoparticles is reported using 0.3 % latex solution prepared from Jatropha curcas L. ZnS nanoparticles were characterized by X-ray diffraction, selected area electron diffraction, transmission electron microscopy, energy dispersive analysis of X-rays, UV-vis optical absorption and photoluminescence techniques. Fourier Transform Infrared Spectroscopy was performed to find the role of cyclic peptides namely curcacycline A (an octapeptide), curcacycline B (a nonapeptide) and curcain (an enzyme) as a possible reducing and stabilizing agents present in the latex of J. curcas L. The average size of ZnS nanoparticles was found to be 10 nm. Latex of J. curcas L. itself acts as a source of sulphide (S-2) ions that are donated to Zn ions under present experimental conditions. Source of sulphide (S-2) ions is still unclear, but we speculate that cysteine or thiol residues present in enzyme curcain may be donating these sulphide (S-2) ions.

  17. Latex-mediated synthesis of ZnS nanoparticles: green synthesis approach

    International Nuclear Information System (INIS)

    Hudlikar, Manish; Joglekar, Shreeram; Dhaygude, Mayur; Kodam, Kisan

    2012-01-01

    A low-cost, green synthesis of ZnS nanoparticles is reported using 0.3 % latex solution prepared from Jatropha curcas L. ZnS nanoparticles were characterized by X-ray diffraction, selected area electron diffraction, transmission electron microscopy, energy dispersive analysis of X-rays, UV–vis optical absorption and photoluminescence techniques. Fourier Transform Infrared Spectroscopy was performed to find the role of cyclic peptides namely curcacycline A (an octapeptide), curcacycline B (a nonapeptide) and curcain (an enzyme) as a possible reducing and stabilizing agents present in the latex of J. curcas L. The average size of ZnS nanoparticles was found to be 10 nm. Latex of J. curcas L. itself acts as a source of sulphide (S −2 ) ions that are donated to Zn ions under present experimental conditions. Source of sulphide (S −2 ) ions is still unclear, but we speculate that cysteine or thiol residues present in enzyme curcain may be donating these sulphide (S −2 ) ions.

  18. Safety Evaluation Test on Human for Radiation Pre vulcanised Natural Rubber Latex (RVNRL)

    International Nuclear Information System (INIS)

    Pairu Ibrahim; Wan Manshol Wan Zain; Chai, Chee Keong; Sofian Ibrahim; Saadiah Sulaiman; Sharifah Ismail

    2010-01-01

    This paper discussed about clinical test conducted to determine safety evaluations on human for latex examination gloves and latex films made from Radiation Vulcanized Natural Rubber Latex (RVNRL). Two types of test were being adopted which are i) Modified Draize-95 test and ii) Patch Test on Sensitized Individuals. Modified Draize-95 test was conducted on 200 non-sensitized human subjects and Patch Test on Sensitized Individuals was conducted on 25 individuals who are allergic to the defined major chemical sensitizer presents in natural rubber product. It was found that Modified Draize-95 test has prove that there is no clinical evidence on the presence of residual chemical additives at the level that may induce Type IV allergy in the un sensitized general user population in the RVNRL gloves. Meanwhile Patch Test on Sensitized Individuals has proved that the patch test conducted using the test article on 25 individuals who are allergic to the defined major chemical sensitizers present in natural rubber products, thiuram, carbamates or thiazoles produced a negative response, meeting the pre requirement for the claim of reduced reaction-inducing potential. (author)

  19. Hierarchically structured self-supported latex films for flexible and semi-transparent electronics

    Science.gov (United States)

    Määttänen, Anni; Ihalainen, Petri; Törngren, Björn; Rosqvist, Emil; Pesonen, Markus; Peltonen, Jouko

    2016-02-01

    Different length scale alterations in topography, surface texture, and symmetry are known to evoke diverse cell behavior, including adhesion, orientation, motility, cytoskeletal condensation, and modulation of intracellular signaling pathways. In this work, self-supported latex films with well-defined isotropic/anisotropic surface features and hierarchical morphologies were fabricated by a peel-off process from different template surfaces. In addition, the latex films were used as substrates for evaporated ultrathin gold films with nominal thicknesses of 10 and 20 nm. Optical properties and topography of the samples were characterized using UV-vis spectroscopy and Atomic Force Microscopy (AFM) measurements, respectively. The latex films showed high-level transmittance of visible light, enabling the fabrication of semi-transparent gold electrodes. Electrochemical impedance spectroscopy (EIS) measurements were carried out for a number of days to investigate the long-term stability of the electrodes. The effect of 1-octadecanethiol (ODT) and HS(CH2)11OH (MuOH) thiolation and protein (human serum albumin, HSA) adsorption on the impedance and capacitance was studied. In addition, cyclic voltammetry (CV) measurements were carried out to determine active medicinal components, i.e., caffeic acid with interesting biological activities and poorly water-soluble anti-inflammatory drug, piroxicam. The results show that the fabrication procedure presented in this study enables the formation of platforms with hierarchical morphologies for multimodal (optical and electrical) real-time monitoring of length-scale-dependent biomaterial-surface interactions.

  20. Evaluation of force degradation characteristics of orthodontic latex elastics in vitro and in vivo.

    Science.gov (United States)

    Wang, Tong; Zhou, Gang; Tan, Xianfeng; Dong, Yaojun

    2007-07-01

    To evaluate the characteristics of force degradation of latex elastics in clinical applications and in vitro studies. Samples of 3/16-inch latex elastics were investigated, and 12 students between the ages of 12 and 15 years were selected for the intermaxillary and intramaxillary tractions. The elastics in the control groups were set in artificial saliva and dry room conditions and were stretched 20 mm. The repeated-measure two-way analysis of variance and nonlinear regression analysis were used to identify statistical significance. Overall, there were statistically significant differences between the different methods and observation intervals. At 24- and 48-hour time intervals, the force decreased during in vivo testing and in artificial saliva (P .05). In intermaxillary traction the percentage of initial force remaining after 48 hours was 61%. In intramaxillary traction and in artificial saliva the percentage of initial force remaining was 71%, and in room conditions 86% of initial force remained. Force degradation of latex elastics was different according to their environmental conditions. There was significantly more force degradation in intermaxillary traction than in intramaxillary traction. The dry room condition caused the least force loss. There were some differences among groups in the different times to start wearing elastics in intermaxillary traction but no significant differences in intramaxillary traction.

  1. Natural membranes of Hevea brasiliensis latex as delivery system for Casearia sylvestris leaf components

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    Flávio A. Carvalho

    Full Text Available ABSTRACT Natural latex from Hevea brasiliensis (Wild. ex A.Juss Müll.Arg., Euphorbiaceae, showed angiogenic action and Casearia sylvestris Sw., Salicaceae, leaf derivatives presented anti-inflammatory and wound healing activities. Therefore, an association of these effects was interesting for wound healing applications. The aims of this study were the development of membranes of natural latex incorporated with C. sylvestris leaf derivatives (ethanolic extract, diterpene concentrated fraction and casearin J, their chemical and physical characterization, and the evaluation of in vitro skin permeation and retention of C. sylvestris bioactive secondary metabolites (diterpenes and phenolic compounds. The membranes were developed mixing hydroethanolic solutions of C. sylvestris derivatives with latex and drying them in a desiccator. They were characterized by infrared spectroscopy, scanning electron microscopy, water vapor permeability and mechanical resistance assays, demonstrating that all membranes were permeable, resistant and homogeneous in surfaces. The permeation and retention assays demonstrated dermal penetration of phenolic compounds for ethanolic extract membrane and of casearin-like clerodane diterpenes for all membranes, indicating that these membranes have great potential for therapeutical application as a topical system for C. sylvestris components releasing.

  2. Clonal stability of latex yield in eleven clones of Hevea brasiliensis Muell. Arg.

    Directory of Open Access Journals (Sweden)

    K.O. Omokhafe

    2003-01-01

    Full Text Available Eleven Hevea brasiliensis clones were evaluated for clonal stability of latex yield. A randomized complete block design was used with four replicates, two locations, seven years and three periods per year. Stability analysis was based on clone x year and clone x year x location interactions. Five stability parameters viz environmental variance, shukla's stability variance, regression of clonal latex yield on environmental index, variance due to regression and variance due to deviation from regression were applied. There was significant clone x environment effect at the two levels of interaction. Among the eleven clones, C 162 was outstanding for clonal stability and it can serve as donor parent for stability alleles. Three clones (C 76, C 150 and C 154 were also stable. The four stable clones (C 76, C 150, C 154 and C 162 are suitable for broad-spectrum recommendation for latex yield. Five clones (C 83, C 143, C 163, C 202 and RRIM 600 will require environment-specific recommendation because of their unstable phenotype. The stability feature of two clones (C 145 and C 159 was not clear and this will be investigated in subsequent studies.

  3. Antimalarial Activity of the Chemical Constituents of the Leaf Latex of Aloe pulcherrima Gilbert and Sebsebe.

    Science.gov (United States)

    Teka, Tekleab; Bisrat, Daniel; Yeshak, Mariamawit Yonathan; Asres, Kaleab

    2016-10-28

    Malaria is one of the three major global public health threats due to a wide spread resistance of the parasites to the standard antimalarial drugs. Considering this growing problem, the ethnomedicinal approach in the search for new antimalarial drugs from plant sources has proven to be more effective and inexpensive. The leaves of Aloe pulcherrima Gilbert and Sebsebe, an endemic Ethiopian plant, are locally used for the treatment of malaria and other infectious diseases. Application of the leaf latex of A. pulcherrima on preparative silica gel TLC led to the isolation of two C -glycosylated anthrones, identified as nataloin ( 1 ) and 7-hydroxyaloin ( 2 ) by spectroscopic techniques (UV, IR, ¹H- and 13 C-NMR, HR-ESIMS). Both the latex and isolated compounds displayed antimalarial activity in a dose-independent manner using a four-day suppressive test, with the highest percent suppression of 56.2% achieved at 200 mg/kg/day for 2 . The results indicate that both the leaf latex of A. pulcherrima and its two major constituents are endowed with antiplasmodial activities, which support the traditional use of the leaves of the plant for the treatment of malaria.

  4. Content of Asthmagen Natural Rubber Latex Allergens in Commercial Disposable Gloves.

    Science.gov (United States)

    Bittner, C; Garrido, M V; Krach, L H; Harth, V

    The use of natural rubber latex (NRL) gloves in many occupations may lead to latex sensitization, allergic asthma, and skin reactions. Due to their good properties and environmental safety NRL gloves are still being used in the healthcare setting, but also in the food industry, by hairdressers, cleaners, etc. The aim of our study was to assess the protein and NRL allergen content in commercial gloves by different methods, including a new assay. Twenty commercially available NRL gloves were analyzed. Protein extraction was performed according to the international standard ASTM D-5712. Total protein content was measured with a modified Lowry method, NRL content with the CAP Inhibition Assay, the Beezhold ELISA Inhibition Assay, and an innovative ELISA with IgY-antibodies extracted from eggs of NRL-immunized hens (IgY Inhibition Assay). We found a high protein content in a range of 215.0-1304.7 μg/g in 8 out of the 20 NRL gloves. Seven of the 20 gloves were powdered, four of them with a high protein content. In gloves with high protein content, the immunological tests detected congruently high levels of NRL allergen. We conclude that a high percentage of commercially available NRL gloves still represent a risk for NRL allergy, including asthma. The modified Lowry Method allows to infer on the latex allergen content.

  5. Prevalence and clinical impact of sensitization to latex and fruits in dentistry students at the University of Antioquia, and its relationship with allergy to fruits

    Directory of Open Access Journals (Sweden)

    Echenique Manrique, Alejandro

    2015-04-01

    Full Text Available Objective: To determine the prevalence and clinical impact of sensitization to latex and to five tropical fruits (banana, avocado, kiwi, pineapple and passion fruit in dentistry students. Methods: Analytical cross-sectional study of 128 dentistry students at University of Antioquia in Medellín, Colombia. Information was collected by means of a questionnaire and skin prick tests with latex and fruits were done. Results: All students reported having had contact with latex. Nine of them informed at least one episode of adverse reaction to contact with latex without proof of sensitization to it. Five reported at least one reaction with one of the fruits, but skin prick tests were negative. Four of the 14 students who reported gastrointestinal symptoms were sensitized to latex or to one of the tested fruits. Overall, latex sensitization rate was 3.1%. Conclusion: This percentage of sensitization to latex is lower than that in other studies; this may be due to the expression of immune mechanisms other than IgE mediation. We failed to demonstrate a higher sensitization rate to latex as students advanced in their career. The association between gastrointestinal symptoms and sensitization to both fruit and latex is to be emphasized.

  6. Resistência de biótipos de Euphorbia heterophylla l. Aos herbicidas inibidores da enzima ALS utilizados na cultura de soja Resistance of Euphorbia heterophylla l. Biotypes to ALS enzyme inhibitor herbicides used in soybean crop

    Directory of Open Access Journals (Sweden)

    GERSON AUGUSTO GELMINI

    2001-01-01

    Full Text Available Os herbicidas constituem-se na principal medida de controle de plantas daninhas na cultura de soja; no entanto, a pressão de seleção causada pelo uso contínuo de produtos com o mesmo mecanismo de ação pode provocar a seleção de biótipos resistentes, como ocorreu com Euphorbia heterophylla L., que se mostrou resistente aos herbicidas inibidores da enzima acetolactato sintase (ALS em áreas dos Estados do Paraná e Rio Grande do Sul. Para comprovar possíveis novos casos, bem como alternativas para prevenção e manejo, coletaram-se sementes de plantas de E. heterophylla L., na região de Assis (SP, que sobreviveram a tratamentos, em que esses herbicidas foram sistematicamente aplicados nos últimos anos. Desenvolveu-se o experimento em casa de vegetação, comparando-se o biótipo resistente ao suscetível, quando submetido aos diversos herbicidas aplicados em pós-emergência. Aplicaram-se quando as plantas encontravam-se no estádio de duas a quatro folhas verdadeiras, nas doses zero, uma, duas, quatro e oito vezes a recomendada. Aos 20 dias após a aplicação, avaliaram-se os parâmetros relativos ao controle e produção de fitomassa epígea visando ao estabelecimento de curvas de doses-resposta, à obtenção dos fatores de resistência com base nos valores da DL50 e GR50, e à verificação da ocorrência de resistência múltipla. O biótipo resistente apresentou diferentes níveis de resistência aos herbicidas chlorimuron-ethyl e imazethapyr, demonstrando resistência cruzada aos inibidores da ALS dos grupos das sulfoniluréias e imidazolinonas. No entanto, foi eficientemente controlado nos tratamentos com fomesafen (250 g.ha-1, lactofen (120 g.ha-1, flumiclorac-pentil (40 g.ha-1, glufosinato de amônio (150 g.ha-1 e glyphosate (360 g.ha-1.Herbicides are the main tool for weed control in soybean crop, but the selection pressure attributed to the repeated application of the same herbicides and the same mechanism of action can

  7. Assessment of the mutagenic and antimutagenic activity of Synadenium umbellatum Pax latex by micronucleus test in mice

    Directory of Open Access Journals (Sweden)

    PR. Melo-Reis

    Full Text Available Synadenium umbellatum Pax, popularly known as "cola-nota", is a medicinal plant that grows in tropical regions. The latex of this plant is used against various diseases, such as diabetes mellitus, leprosy, tripanosomiasis, leukemia, and several malignant tumors. The mutagenic, antimutagenic, and cytotoxic effects of the latex of this plant were investigated by measuring the frequency of micronuclei in mice bone marrow cells. To evaluate mutagenicity, the animals were treated with four doses of latex (10, 30, 50, and 100 mg/kg body weight. To study the antimutagenic activity, the animals were simultaneously treated with latex and mitomycin C (4 mg/kg. The cytotoxicity was evaluated by polychromatic and normochromatic erythrocytes ratio. Our results showed a significant increase of frequency of micronucleated polychromatic erythrocytes (MNPCE compared to the negative control group (p 0.05 was detected at the doses of 50 and 100 mg/kg. Under our experimental conditions, the results obtained indicate strong mutagenic and cytotoxic activity of S. umbellatum latex except the dose of 10 mg/kg and moderate antimutagenic effect at lower doses.

  8. Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2014-01-01

    Full Text Available This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA as partial replacement of cement in presence of copolymer latexes. Portland cement (PC was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA and 2-hydroxymethylacrylate (2-HEMA. Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM. The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  9. Effect of copolymer latexes on physicomechanical properties of mortar containing high volume fly ash as a replacement material of cement.

    Science.gov (United States)

    Negim, El-Sayed; Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

    This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA) as partial replacement of cement in presence of copolymer latexes. Portland cement (PC) was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA) and 2-hydroxymethylacrylate (2-HEMA). Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM). The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final) were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  10. Identification, quantification, spatiotemporal distribution and genetic variation of major latex secondary metabolites in the common dandelion (Taraxacum officinale agg.).

    Science.gov (United States)

    Huber, Meret; Triebwasser-Freese, Daniella; Reichelt, Michael; Heiling, Sven; Paetz, Christian; Chandran, Jima N; Bartram, Stefan; Schneider, Bernd; Gershenzon, Jonathan; Erb, Matthias

    2015-07-01

    The secondary metabolites in the roots, leaves and flowers of the common dandelion (Taraxacum officinale agg.) have been studied in detail. However, little is known about the specific constituents of the plant's highly specialized laticifer cells. Using a combination of liquid and gas chromatography, mass spectrometry and nuclear magnetic resonance spectrometry, we identified and quantified the major secondary metabolites in the latex of different organs across different growth stages in three genotypes, and tested the activity of the metabolites against the generalist root herbivore Diabrotica balteata. We found that common dandelion latex is dominated by three classes of secondary metabolites: phenolic inositol esters (PIEs), triterpene acetates (TritAc) and the sesquiterpene lactone taraxinic acid β-D-glucopyranosyl ester (TA-G). Purification and absolute quantification revealed concentrations in the upper mgg(-1) range for all compound classes with up to 6% PIEs, 5% TritAc and 7% TA-G per gram latex fresh weight. Contrary to typical secondary metabolite patterns, concentrations of all three classes increased with plant age. The highest concentrations were measured in the main root. PIE profiles differed both quantitatively and qualitatively between plant genotypes, whereas TritAc and TA-G differed only quantitatively. Metabolite concentrations were positively correlated within and between the different compound classes, indicating tight biosynthetic co-regulation. Latex metabolite extracts strongly repelled D. balteata larvae, suggesting that the latex constituents are biologically active. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Assay of anti-HBs antibodies using a recombinant antigen and latex particle counting: comparison with five commercial tests.

    Science.gov (United States)

    Galanti, L M; Cornu, C; Masson, P L; Robert, A R; Becheanu, D; Lamy, M E; Cambiaso, C L

    1991-05-01

    An assay of anti-HBs antibodies based on agglutination of latex particles coated with recombinant HBs-antigen was compared with Abbott radioimmunoassay (Abbott-RIA), which uses a human plasma-derived antigen. The population examined consisted of 76 Abbott-RIA anti-HBs-negative prevaccinated subjects and 1044 serum samples anti-HBs found positive by Abbott-RIA, including 283 samples of subjects vaccinated either with a human plasma-derived vaccine (group A; n = 180) or with a recombinant vaccine (group B; n = 103). Correlation coefficients between the two techniques were respectively r = 0.89 for the whole population (n = 1044), r = 0.98 in group A and r = 0.74 in group B. Anti-HBs titres were higher with latex than with RIA in group B as shown by the regression slopes: latex = 508 + 1.11 RIA in group A and latex = -1138 + 3.97 RIA in group B, suggesting that some vaccinated subjects from group B produced antibodies against epitopes proper to the recombinant antigen. In the prevaccinated population and in group A, the latex results were compared with those of radioimmunoassays (Abbott, Sorin) and enzyme immunoassays (Behring, Roche, Pasteur). Only the Roche-EIA detected anti-HBs in the prevaccinated subjects. The correlation between the various immunoassays was r greater than 0.96 only for values higher than 100 IU/l.

  12. Development and detection efficiency of sequence characterized amplified region markers for authentication of medicinal plant Ruta graveolens and its adulterant Euphorbia dracunculoides

    Directory of Open Access Journals (Sweden)

    Irum Gul

    2016-01-01

    Full Text Available Background: With the increase in demand of herbal medicines, adulteration in these drugs is also gaining momentum and remains an indispensable problem in domestic and export markets. Correct identification is the first step toward assuring quality, safety, and efficacy of indigenous herbal medicines. Materials and Methods: In this study, sequence characterized amplified region (SCAR markers were developed to discriminate Ruta graveolens from its adulterant Euphorbia dracunculoides. Random amplified polymorphic DNA (RAPD was performed and subsequently converted into SCAR markers. Results: After performing RAPD, SCAR primers were designed from the selected unique RAPD amplicons of the genuine drug as well as its adulterant. These primers produced 670 bp and 750 bp SCAR markers with genomic DNA sample of R. graveolens and E. dracunculoides, respectively. Conclusion: Development of these markers will help in the quality control of herbal drugs and monitoring widespread adulteration of these drugs by pharmaceutical industries and government agencies.

  13. Synthesis and characterization of novel fluoroalkyl-terminated hyperbranched polyurethane latex

    Science.gov (United States)

    Xu, Wei; Zhao, Weijia; Hao, Lifen; Wang, Sha; Pei, Mengmeng; Wang, Xuechuan

    2018-04-01

    Waterborne polyurethane (PU) emulsions are widely used in various fields and the demand for them is ever-increasing over the years. However, the hydrophilic chain extender inevitably bonded into the PU backbone can affect the water tolerance of PU. Thus, it is of great importance to improve PU water resistance effectively. Herein, novel fluoroalkyl-terminated hyperbranched polyurethane (HBPUF) latex was accordingly synthesized by graft reaction of perfluorohexyl ethyl alcohol and hyperbranched polyurethane (HBPU), which was previously obtained from interaction between hydroxyl-terminated hyperbranched polymer and PU prepolymer manufactured via the acetone process, as well as using neutralization, adding water, and high-speed stirring operations. We characterized the resultants and investigated its surface properties by IR, NMR, TEM, XRD, TGA, DSC, FE-SEM, AFM, XPS, and contact angle measurements, etc. IR and NMR tests confirmed that the fluorinated fragments had been grafted onto the tail end of HBPU. TEM, XRD, DSC, and FE-SEM results all accounted for the fact that there were multi-crystals in PU, HBPU and HBPUF. TGA results showed that thermal stabilities of the PU, HBPU, and HBPUF latex films were enhanced in turn. XPS and AFM analyses demonstrated that the fluorine-containing segments from the HBPUF terminals were prone to migrate and enrich on the film-air surface of the HBPUF latex film, which made water contact angle and water absorption of the HBPUF film be as 113.9° and 11.1%, respectively, compared to those of the PU film (77.8° and 136.2%). This research indicates that water resistance of the PU film can be efficiently enhanced by fluorinated polyurethane with novel fluoroalkyl-terminated hyperbranched structure.

  14. Physical-biopolymer characterization of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) blended with natural rubber latex

    Energy Technology Data Exchange (ETDEWEB)

    Kuntanoo, K., E-mail: thip-kk@hotmail.com [Graduate School of Khon Kaen University, Khon Kaen, 40002 Thailand (Thailand); Promkotra, S., E-mail: sarunya@kku.ac.th [Department of Geotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand); Kaewkannetra, P., E-mail: paknar@kku.ac.th [Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002 Thailand (Thailand)

    2015-03-30

    A biopolymer of polyhydroxybutyrate-co-hydroxyvalerate (PHBV) is blended with bio-based materials, natural rubber latex, to improve their microstructures. The various ratios between PHBV and natural rubber latex are examined to develop their mechanical properties. In general, physical properties of PHBV are hard, brittle and low flexible while natural rubber (NR) is presented itself as high elastic materials. Concentrations of the PHBV solution are constituted at 1%, 2% and 3% (w/v). The mixtures of their PHBV solutions to natural rubber latex are produced the blended films in three different ratios of 4:6, 5:5 and 6:4, respectively. They are characterized by appearance analyses which are the scanning electron microscope (SEM), universal testing machine (UTM) and differential scanning calorimetry (DSC). The SEM photomicrographs of the blended films and the controlled PHBV can provide the void distribution in the range of 12-14% and 19-21%, respectively. For mechanical properties of the blended films, the various elastic moduli of 1%, 2% and 3% (w/v) PHBV are the average of 773, 956 and 1,007 kPa, respectively. The tensile strengths of the blends increase with the increased concentrations of PHBV, similarly trend to the elastic modulus. The crystallization and melting behavior of unmixed PHBV and the blends are determined by DSC. Melting transition temperatures (T{sub m}) of the unmixed PHBV are stated two melting peak at 154°C and 173°C. Besides, the melting peaks of the blends alter in the range of 152-156°C and 168-171°C, respectively. According to morphology of the blends, the void distribution decreases twice compared to the unmixed PHBV. The results of mechanical properties and thermal analysis indicate that the blended PHBV can be developed their properties by more resilient and wide range of temperature than usual.

  15. Copolymer natural latex in concrete: Dynamic evaluation through energy dissipation of polymer modified concrete

    Science.gov (United States)

    Andayani, Sih Wuri; Suratman, Rochim; Imran, Iswandi; Mardiyati

    2018-05-01

    Portland cement concrete have been used in construction due to its strength and ecomical value. But it has some limitations, such low flexural strength, low tensile strength, low chemical resistant and etc. Due to its limitations in flexural and tensile strength, Portland cement concrete more susceptible by seismic force. There are some methods for improving its limitations. Polymer addition into concrete mixture could be one of solution for improving the flexural and tensile strength, in aiming to get erthquake resistant properties. Also, the eartquake resistant could be achieved by improving energy dissipation capacity. In this research, the earthquake resistant evalution was approached from dynamic evaluation through energy dissipation capacity, after polymer addition as concrete additives. The polymers were natural latex (Indonesian naural resource) grafted with styrene and methacrylate, forming copolymer - natural latex methacrylate (KOLAM) and copolymer - natural latex styrene (KOLAS). They were added into concrete mixture resulting polymer modified concrete. The composition of polymer are 1%, 5% and 10% weight/weight of cement. The higher capacity of energy dissipation will give more capability in either absorbing or dissipating energy, and it was predicted would give better earthquake resistant.. The use of KOLAM gave better performance than KOLAS in energy dissipation capacity. It gave about 46% for addition of 1% w/w compared to Portland cement concrete. But for addition 5% w/w and 10% w/w, they gave about 7% and 5% higher energy dissipation capacity. The KOLAM addition into concrete mixture would reduce the maximum impact load with maximumabout 35% impact load reducing after 1% w/w addition. The higher concentration of KOLAM in concrete mixture, lower reducing of impact load, they were about 4% and 3% for KOLAM 5% and 10%. For KOLAS addition in any compositions, there were no positive trend either in energy dissipation capacity or impact load properties

  16. Isolation of natural inhibitors of papain obtained from Carica papaya latex

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    Rubens Monti

    2004-09-01

    Full Text Available Studies were carried out to natural papain inhibitor from papaya latex. Fresh latex from green fruits of Carica papaya was collected and immediately transported in ice bath to the lab, from which three fractions with inhibitor effect of esterase papain activity were isolated by latex dialysis, Sephadex G-25 gel filtration and ionic exchange chromatography in SP-Sephadex C-25. The isolated fractions, identified as inhibitors I and II, showed a negative reaction with ninhydrin; however, the fraction identified as P-III showed positive reaction with ninhydrin. Kinetics data showed non-competitive inhibition (inhibitor I and uncompetitive (inhibitors II and P-III.Este trabalho apresenta novos dados sobre inibidores naturais de papaína. O látex fresco de frutos verdes de Carica papaya foi coletado pela manhã em plantações da região de Araraquara, SP, Brasil e imediatamente transportado ao laboratório em banho de gelo. Três frações com efeito inibitório da atividade esterásica da papaína foram isoladas a partir do látex fresco, através de diálise, filtração em Sephadex G-25 e cromatografia em SP-Sephadex C-25. As frações isoladas identificadas como inibidores I e II, mostraram reação negativa à ninidrina; entretanto, a fração identificada como P-III mostrou reação positiva. Dados cinéticos revelaram inibição não-competitiva (inibidor I e incompetitiva (inibidores II e P-III.

  17. Water stress on the performace of herbicides and biochemical characteristics of Euphorbia heterophyllaDéficit hídrico na eficiência de herbicidas e nas características bioquímicas de Euphorbia heterophylla

    Directory of Open Access Journals (Sweden)

    Caio Ferraz Campos

    2013-03-01

    Full Text Available The objective of this work was to evaluate conditions the effectiveness of acetolactate synthase (ALS and protoporphyrinogen oxidase (PROTOX inhibitors in the Bidens pilosa control under two water deficit conditions, as well as to determine the action under the content of soluble carbohydrates and protein and free amino acids of weed. The experimental design was randomized completely design, with four replications, with the treatments setup in a factorial scheme 4x2, with four herbicides (fomesafen lactofen, chlorimuron-ethyl and imazethapyr, and two soil water conditions (-0.5 MPa and –0.01MPa. At 7, 14, 21 and 28 days after application (DAA, was assessed visually control efficiency of herbicides. For the determination of organic solutes plants were collected at 24, 48, 72 and 96 hours after application (HAA, except for the amino acids were analyzed 48, 72 e 96 HAA. Herbicides fomesafen and lactofen were efficient to control E. heterophylla, while the ALS inhibitors (chlorimuron-ethyl e imazethapyr provided an unsatisfactory control. Water deficit altered the efficiency of herbicides, mainly chlorimuronethyl. Lactofen provided a smaller content of soluble carbohydrates, in the same way, the protein ranged in the 72 HAA, the lower value observed for imazethapyr e lactofen respectively. Herbicide lactofen increased the concentration of free amino acids, while the imposition of water deficit caused an increase in soluble carbohydrate content.O estudo teve como objetivo avaliar a eficiência de herbicidas inibidores da acetolactato sintase (ALS e protoporfirinogênio oxidase (PROTOX no controle de Euphorbia heterophylla sob duas condições hídricas, bem como determinar a ação destes sob o conteúdo de carboidratos e proteínas solúveis e aminoácidos livres da planta daninha. O delineamento experimental utilizado foi inteiramente casualizado, com quatro repetições, com os tratamentos dispostos em esquema fatorial 4x2, sendo quatro

  18. ENHANCEMENT OF RESISTANCE TO OXIDATIVE DEGRADATION OF NATURAL RUBBER THROUGH LATEX DEGRADATION

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A fully characterised natural rubber latex was subjected to mechanical degradation by stirring at intervals. The resistance to oxidative degradation of the different samples were studied by measuring the Plasticity retention indices (PRI).The results show that there is an enhancement of the PRI from 57% for the undegraded rubber to 79% for the one-hour degraded sample. Further degradation resulted in decrease of PRI as time of degradation increased. Therefore, the one-hour degraded sample is a special rubber with high oxidation resistance which is of great importance in engineering.

  19. Posters y trípticos (Brochures) en LATEX con Beamer y Leaflet

    OpenAIRE

    Borbón, Alexánder

    2013-01-01

    Resumen. En este artículo se muestra la manera en que se puede realizar posters y trípticos (panfletos o brochures) con LATEX. Para realizar los posters se utiliza la clase beamer que usualmente se utiliza para hacer presentaciones, se utiliza el paquete beamerposter para poder utilizarla para posters. Los trípticos se realizan de dos formas, la primera utilizando la clase beamer con el paquete geometry y la segunda utilizando la clase leaflet que es una clase especializada para hacer este ti...

  20. The influence of radiolytic sensitizers in natural rubber latex vulcanization induced by ionizing radiation

    International Nuclear Information System (INIS)

    Guedes, S.M.L.; Souza, A. de

    1991-01-01

    This work made on radiation vulcanization of natural rubber latex process by gamma rays from 60 Co source and electron beam of 1.5 MeV, 25 m A by Dynamitron, instead of classic process using sulfur. The experiment was carried out to study the influence of sensitizers (C Cl 4 and n-butyl acrylate) and was reported the vulcanization dose for each sensitizers, related to maximum tensile strength. The results show the possibility to introduce the volatile sensitizer (n-butyl acrylate) instead of C Cl 4 (toxic) in industry applications. (author)

  1. Surgical gloves fabrication using natural rubber latex vulcanized with gamma radiation

    International Nuclear Information System (INIS)

    Collantes, Hugo David Chirinos.

    1995-01-01

    Surgical gloves were manufactured by immersion coagulant method from vulcanized natural rubber latex by gamma rays at dose of 10 kGy in the air, at room temperature, using the following sensitizer vulcanization An-B 3 phr/KOH 0.2 phr. The influence of the parameter in the thickness of the surgical gloves manufacture, studied through fractional factorial designs technic, can be resumed by empirical linear correlation: y = 0.213 + 0.025 [Ca Cl 2 ] + 0.019 t. (author). 49 refs., 13 figs., 31 tabs

  2. Effect of Antioxidants on Radiation Vulcanization Natural Rubber Latex (RVNRL) Film

    International Nuclear Information System (INIS)

    Syuhada Ramli; Sofian Ibrahim; Muhammad Saiful Omar

    2015-01-01

    This paper presents the results on the effects of different antioxidants used in Radiation Vulcanization Natural Rubber Latex (RVNRL)) films between 0 to 10 weeks monitoring. Antioxidants used for the RVNRL formulation were Aquanox LP, Irganox and Wingstay L. Color difference evaluation by using Chroma Meter CR-400 found that RVNRL film with Irganox was the most stained yellowish after 8 weeks monitoring. Tensile strength for RVNRL with Aquanox found achieved the optimum strength between 25.4 to 27.13 mPa. The scanner electron microscopic (SEM) indicated more Aquanox molecules to penetrate and interact with the rubber molecule, thus becoming more effective inhibitor against its oxidative ageing. (author)

  3. Modification of Iraqi Asphalt 40/50 Properties Using Saw Dust (SD and Natural Rubber Latex

    Directory of Open Access Journals (Sweden)

    Rusul l M. Darwesh

    2018-04-01

    Full Text Available The aim of this research is to enhance the fundamental properties for asphalt binder as those spec-ifications relate to performance of asphalt mixtures. In this paper studied the effect of add (2, 4 % SD in different sizes and (3, 5 and 7% Natural rubber latex to the straight asphalt 40/50 produced from Al-Dura refinery at 160C, it was added each additive separately and then added together to asphalt in same temperature, then tested physically and mechanically according to the American Society for Testing and Materials (ASTM, the result showed largely improvement.

  4. Produção de Bipolaris euphorbiae em meios de cultura sólidos e líquidos obtidos de grãos e resíduos agroindustriais Production of Bipolaris euphorbiae in solid and liquid culture media obtained from grains and agricultural industry residues

    Directory of Open Access Journals (Sweden)

    Mara Cristina Penariol

    2008-12-01

    Full Text Available A introdução de Bipolaris euphorbiae como bioagente de controle de Euphorbia heterophylla é dependente da produção de conídios em grande quantidade. No presente trabalho, objetivou-se definir meios de cultura sólidos e líquidos, obtidos de grãos ou resíduos da agroindústria, eficazes para a produção de conídios de B. euphorbiae. No preparo dos meios sólidos utilizaram-se grãos de arroz, trigo e sorgo, quirelas de arroz, milho e trigo, sorgo moído, farelos de arroz, trigo e soja, cascas de mandioca e soja, casca de mandioca + farelo de soja, bagaço de cana e bagaço de cana + amido solúvel. No preparo dos meios líquidos, utilizaram-se grãos de arroz, sorgo e trigo, quirela de milho, farelos de trigo, soja e arroz, casca de mandioca e soja, vinhaça de cana e água de prensa da mandioca. Avaliaram-se a produção e a viabilidade dos conídios e a virulência do fungo e, nos meios líquidos, também a biomassa. A produção de conídios é influenciada pelo tipo de meio de cultura, sendo acentuadamente maior nos meios sólidos, destacando-se, como substratos, o sorgo em grão (474 x 10(6 conídios g-1 e a casca de soja (472 x 10(6 conídios g-1. Dentre os meios líquidos obteve-se mais produção usando-se farelo de trigo (1,33 x 10(6 conídios mL-1. A virulência e a viabilidade de B. euphorbiae não são afetadas pelo preparo de meios sólidos ou líquidos e pela composição nutricional dos meios de cultura. Na maioria dos meios sólidos ou líquidos obteve-se viabilidade de conídios maior que 98%; apenas os conídios produzidos nos meios sólidos de quirela de arroz, casca de mandioca + farelo de soja e farelo de soja estavam com viabilidade significativamente menor.The introduction of Bipolaris euphorbiae as a bioagent for Euphorbia heterophylla control depends on fungal conidia production in large amount. This work evaluate to solid and liquid culture media obtained from grains and residues from agriculture industries

  5. An evidence-based approach to medication preparation for the surgical patient at risk for latex allergy: is it time to stop being stopper poppers?

    Science.gov (United States)

    Heitz, James W; Bader, Stephen O

    2010-09-01

    The prevalence of latex allergy is increasing in surgical patient populations. Avoidance of exposure to the allergen is essential to minimizing perioperative complications in patients suspected to be at risk. Natural rubber latex has historically been ubiquitous in medical devices containing rubber. In 1998, the Food and Drug Administration (FDA) began to require the labeling of medical devices made from natural rubber latex; since that time substantial progress has been made in identifying latex-free alternatives. However, the rubber stoppers commonly found in pharmaceutical vial closures are exempt from FDA labeling requirements. Examination of the clinical and basic science literature regarding pharmaceutical vial closures supports limiting the rubber stopper to a single needle puncture as a safer practice, with the caveat that no strategy exists for the complete elimination of risk as long as stoppers made from natural rubber latex are used in pharmaceutical vials intended for human use. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. EFFECT OF THE PHASE STRUCTURE EVOLUTION ON THE PROPERTIES OF FILMS FORMED FROM PBA/P(ST-CO-MMA)COMPOSITE LATEX

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A group of heterogeneous latexes poly(butyl acrylate)/poly(styrene-co-methyl methacrylate)(PBA/P(St-co-MMA))were prepared by a semi-continuous seeded emulsion polymerization process under monomer starved conditions.The glass transition temperature(Tg)and the mechanical properties of the film formed from the composite latex changed with the evolution of the particle morphology.A photon transmission method was used to monitor the phase structure evolution of films which were prepared from core-shell PBA/P(St-co-MMA)latex at room temperature and annealed at 383 K above Tg of the polymers.In addition,the changes of the surface of the film formed from the composite latex with time at 383 K were observed by AFM.The evidence illustrated that the film formed from the core-shell latex particles was metastable.The rearrangement of the phases could occur under proper conditions.

  7. Preparation of Low Allergenic Protein Concentrated Natural Rubber Latex Using Suitable Low Molecular Weight Cellulose Derivatives Induced by Gamma Irradiation

    International Nuclear Information System (INIS)

    Siri-Upathum, Chyagrit; Boonyawat, Jariya

    2007-08-01

    Full text: Low molecular weight carboxy methyl cellulose (CMC), hydroxyl ethyl cellulose (HEC), hydroxyl propyl cellulose (HPC) and methyl cellulose (MC) prepared by radiation-induced degradation were added into diluted natural concentrated latex prior to centrifuge for a purpose of reducing allergenic rubber protein in the latex. Optimum molecular weight (Mv) of CMC and HEC for such a purpose was found to be 17-18 kDa which decreased allergenic rubber protein (14-94 kDa) to an undetectable amount as determined by SDS PAGE method

  8. Technology of Anticorrosive Protection of Steel Constructions by Coatings Based on Rapid-Hardening Bitumen-Latex Emulsion

    Directory of Open Access Journals (Sweden)

    Nykyforchyn, H.M.

    2016-01-01

    Full Text Available The recipes of rapid-hardening bitumen-latex emulsions and coatings on its base are created, in-laboratory tests of their physical, chemical and anticorrosive properties are carried out. The technology of anticorrosive protection and the installation technical documentation for making of aqueous bitumen-latex emulsion is developed, installation is mounted and a pilot lot of rapid-hardening emulsion is produced. Experimental-industrial approbation of the technology of coating formation on pipes in oil and gas industry is carried out.

  9. Purification and autolysis of the ficin isoforms from fig (Ficus carica cv. Sabz) latex.

    Science.gov (United States)

    Zare, Hamid; Moosavi-Movahedi, Ali Akbar; Salami, Maryam; Mirzaei, Morteza; Saboury, Ali Akbar; Sheibani, Nader

    2013-03-01

    Ficin (EC 3.4.22.3), a cysteine endoproteolytic protease in fig trees' latex, has multiple isoforms. Until now, no data on autolysis of individual ficins (ficin isoforms) are available. Following purification, ficins' autolysis was determined by HPLC chromatogram changes and ultrafiltrations at different temperatures and storage times. These results showed that the number of HPLC peaks in latex proteins purification of Ficus carica cv. Sabz varied from previous fig varieties or cultivars. Proteolytic activity of ficins was inhibited by specific cysteine protease inhibitors, confirming the participation of the cysteine residue in the active site. The zeta potential of the first two eluted peaks (I and II) was negative, while that of other peaks were positive. All ficins were susceptible to autolysis when stored at high temperatures. In contrast, only the last two ficins (B, C) were prone to autolysis at cold temperature after long storage period. The rate of degradation of the ficins was significantly increased with the increased storage time. The ficin (A) related to peak (III) had the highest and the lowest surface hydrophobic patches and ratio of autolytic to proteolytic activity, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Calotropis procera Latex-Induced Inflammatory Hyperalgesia—Effect of Antiinflammatory Drugs

    Directory of Open Access Journals (Sweden)

    Raman Sehgal

    2005-01-01

    Full Text Available The milky white latex of plant Calotropis procera produces inflammation of the skin and mucous membranes on accidental exposure. It produces edema on local administration due to the release of histamine and prostaglandins and is associated with hyperalgesia. In the present study we have evaluated the antiedematous and analgesic activity of antiinflammatory drugs against inflammatory response induced by dried latex (DL of C procera in rat paw edema model. An aqueous extract of DL of C procera was injected into the subplantar surface of the rat paw and the paw volume was measured by a plethysmometer at 0, 1, 2, 6, 12, and 24 hours. Concomitantly the hyperalgesic response was also evaluated by motility test, stair climbing ability test, dorsal flexion pain test, compression test, and observing the grooming behavior. The inhibitory effect of diclofenac and rofecoxib on edema formation and hyperalgesic response was compared with cyproheptadine (CPH. DL-induced edema formation was maximum at 2 hours that was associated with decreased pain threshold, functional impairment, and grooming. Treatment with antiinflammatory drugs and CPH significantly attenuated the edematous response and grooming, increased the pain threshold, and improved functional parameters. Both antiinflammatory and antiserotonergic drugs significantly inhibited the hyperalgesia associated with DL-induced paw edema. Rofecoxib was found to be superior than diclofenac and was as effective as CPH in ameliorating the hyperalgesia. However, it was found to be less effective than CPH in attenuating edema formation.

  11. Diagnostic value of latex agglutination test in diagnosis of acute bacterial meningitis

    Directory of Open Access Journals (Sweden)

    Syeda Fasiha Mohammadi

    2013-01-01

    Full Text Available Objectives: To know the incidence of bacterial meningitis in children below five years of age. To compare conventional culture and antigen detection methods ( Latex agglutination test. Materials and Methods: 100 CSF samples of clinically suspected meningitis cases in children below 5 years of age were included. The samples were subjected to cell count, Gram stain, culture and LAT. The organisms isolated in the study were characterized according to standard procedures. Results: Of the 100 cases studied, 31 cases were diagnosed as ABM by Gram stain, culture and latex agglutination test as per WHO criteria. The hospital frequency of ABM was 1.7%. 15 (48.38 cases were culture positive. Gram stain was positive in 22(70.96 cases and LAT in 17(54.83 cases. Haemophilus influenzae was the most common causative agent of acute bacterial meningitis followed by S.pneumoniae. Case fatality rate was 45.16%.The sensitivity and specificity of LAT was 66.66% and 87.91% respectively. Conclusion : Bacterial meningitis is a medical emergency and early diagnosis and treatment is life saving and reduces chronic morbidity. LAT was more sensitive compared to conventional Gram stain and Culture technique in identifying the fastidious organisms like H.influenzae, S.pneumoniae and Group B Streptococcus. However, the combination of Gram stain, Culture and LAT proved to be more productive than any of the single tests alone.

  12. Purification and biochemical characterization of asclepain c I from the latex of Asclepias curassavica L.

    Science.gov (United States)

    Liggieri, Constanza; Arribére, M Cecilia; Trejo, Sebastián A; Canals, Francesc; Avilés, Francesc X; Priolo, Nora S

    2004-08-01

    In this work we report the isolation, purification and characterization of a new protease from latex of Asclepias curassavica L. Crude extract (CE) was obtained by gathering latex on 0.1 M citric-phosphate buffer with EDTA and cysteine with subsequent ultracentrifugation. Proteolytic assays were made on casein or azocasein as substrates. Caseinolytic activity was completely inhibited by E-64. Stability at different temperatures, optimum pH and ionic strength were evaluated by measuring the residual caseinolytic activity at different times after the incubation. CE showed the highest caseinolytic activity at pH 8.5 in the presence of 12 mM cysteine. CE was purified by cation exchange chromatography (FPLC). Two active fractions, homogeneous by SDS-PAGE, were isolated. The major purified protease (asclepain cI) showed a molecular mass of 23.2 kDa by mass spectrometry and a pI higher than 9.3. The N-terminal sequence showed a high similarity with those of other plant cysteine proteinases. When assayed on N-alpha-CBZ-aminoacid-p-nitrophenyl esters, the enzyme showed higher preference for the glutamine derivative. Determinations of kinetic parameter (km and Kcat) were performed with PFLNA.

  13. Severe complications caused by dissolution of latex with consequent self-disintegration of esophageal plastic tubes.

    Science.gov (United States)

    Löser, C

    2000-09-01

    A case of decisive material degeneration of an esophageal Celestin tube is described: a 50-year-old man with adenocarcinoma of the distal esophagus received a Celestin tube for palliative endoscopic treatment and 8 months later presented with suddenly occurring complete dysphagia. Dissolution of the latex layer in the proximal as well as the distal part of the tube had caused self-disintegration of the Celestin tube and had liberated the monofilament nylon coil which completely obstructed the lumen of the tube. Endoscopic tube removal was only possible by careful attachment of a balloon catheter and peroral extraction after insufflation with contrast medium up to 5 atm. A Medline-based review of the literature revealed different but predominantly severe complications (perforation, hemorrhage, obstruction, and peritonitis) based on material fatigue of the latex layer in esophageal Celestin tubes. At least 6 months after placement of a Celestin tube, regular fluoroscopic controls should be performed to detect early disintegration of the tube. Indication for the placement of Celestin tubes in patients with benign esophageal strictures and longer life expectancy should be assessed very critically.

  14. Development of an efficient process for radiation vulcanization of natural rubber latex using hydroperoxide with sensitizer

    International Nuclear Information System (INIS)

    Siri-upathum, C.; Sonsuk, M.

    1996-01-01

    An attempt was made to reduce irradiation dose for radiation vulcanization of natural rubber latex. A promising method was to partially crosslink the latex by radiation vulcanization using n-butyl acrylate (n-BA) as sensitizer and t-butyl hydroperoxide (BHPO) as a co-sensitizer followed by redox vulcanization using residual BHPO as an oxidant and either fructose or tetra ethylene penta mine as reducing agents. It was found that the irradiation dose was reduced to 4 kGy with 5 phr n-BA as sensitizer and 0.1 phr BHPO as co-sensitizer. Successive crosslinking to full vulcanization was done by redox vulcanization using either 4 phr fructose at 60 degree C for 3 hours of 0.4 phr tetra-ethylene penta mine at room temperature for 1 hour. The rubber films obtained had tensile strength of about 25 MPa, modulus 300% of 0.9 MPa and crosslink density of about 1.5 x 10 19 crosslink/cm 3 . It was noted that the rubber film from the co-vulcanization was the average value of the values obtained by radiation vulcanization and redox vulcanization

  15. A simple kit for rapid field diagnosis of potato virus Y by latex serological test

    Directory of Open Access Journals (Sweden)

    Aarne Kurppa

    1987-07-01

    Full Text Available A simple kit for rapid detection of potato virus Y by latex serological test was developed. The test is carried out on a white cardboard sheet and the results can be read by naked eye in two minutes. A test card of 10 x 6 cm holds latex sensitized antibodies, buffers and other necessary ingredients as dry blue colored formulate on the ringed areas of the card. A test card includes space for six tests and positive and negative controls. The kit also includes disposable plastic sticks for mixing the samples with test reagents and a hand press with disposable plastic tips. For testing, dried reagents are dissolved in drops of sample and mixed. After gentle rotation, samples containing virus appear clearly granulated while samples from healthy plants remain unagglutinated. The testing of undiluted extracts of evenly developed tuber sprouts resulted in over 91 % identity with the results obtained with ELISA that was used as a control method. Testing of diluted leaf extracts reached the same reliability but undiluted leaf extracts from glasshouse grown potatoes were not well suitable as test samples because of their dark green color. No such problems occurred with field grown material and a complete identity with the ELISA readings was true when the samples included secondarily infected potato plants. No reaction to other potato viruses than PVY was obtained by the test kit.

  16. Influence of wearing latex gloves on electric pulp tester readings in children.

    Science.gov (United States)

    Holan, G

    1993-12-01

    Electric pulp testers operated by completing an electric circuit. Latex examination gloves have been claimed to interrupt this circuit and lead to false-negative results. This study was conducted to evaluate the influence of wearing latex gloves on electric pulp tester (EPT) readings. The pulps of 80 maxillary permanent incisors of 22 children 10-13 1/2 years old were tested using the Pelton & Crane 'Vitapulp' instrument. Each tooth was tested twice: with gloves and with bare hands. Teeth failing to respond to the EPT without gloves were excluded from the study. All EPT readings ranged between 1 and 9.5. Five teeth gave the same responses with gloved and ungloved hands. Only five teeth did not respond when gloves were worn, and all of these gave readings near the top of the EPT scale when tested without gloves. The other 70 teeth presented significantly higher readings with gloves than without gloves. It is concluded that removal of examination gloves during the operation of the EPT is necessary only if no response is obtained.

  17. Natural rubber latex used as drug delivery system in guided bone regeneration (GBR

    Directory of Open Access Journals (Sweden)

    Rondinelli Donizetti Herculano

    2009-06-01

    Full Text Available In this work, we propose natural rubber latex (NRL membranes as a protein delivery system. For this purpose Bovine Serum Albumin (BSA was incorporated into the latex solution for in vitro protein delivery experiments. Different polymerization temperatures were used, from -10 to 27 °C, in order to control the membrane morphology. These membranes were characterized by Scanning Electron Microscopy (SEM, Atomic Force Microscopy (AFM, as well as the Lowry Method to measure the BSA release. SEM and AFM microscopy analysis showed that the number, size and distribution of pores in NRL membranes can be varied, as well as its overall morphology. We have found that the morphology of the membrane is the predominant factor for higher protein release, compared with pore size and number of pores. Results demonstrated that the best drug-delivery system was the membrane polymerized at RT (27 °C, which does release 66% of its BSA content for up to 18 days. Our results indicate that NRLb could be used in the future as an active membrane that could accelerate bone healing in GBR.

  18. Determination of immune status in dogs against CPV-2 by recombinant protein based latex agglutination test.

    Science.gov (United States)

    Thomas, Jobin; Singh, Mithilesh; Goswami, T K; Glora, Philma; Chakravarti, Soumendu; Chander, Vishal; Upmanyu, Vikramaditya; Verma, Suman; Sharma, Chhavi; Mahendran, K

    2017-09-01

    Canine parvoviral enteritis is a highly contagious viral illness caused by canine parvovirus-2 (CPV-2) which affects puppies of mainly 6-20 weeks of age. Vaccination is pivotal in preventing and controlling CPV-2 infection. Determination of antibody status is a critical determinant for successful vaccination. The hemagglutination inhibition (HI) test is 'gold standard' test for quantification of antibodies specific to CPV-2, although the execution of this test is not feasible under field conditions. The present study was undertaken to develop a point of care testing to determine immune status prior to CPV-2 vaccination or to detect seroconversion in immunized dogs by latex agglutination test (LAT) using recombinant antigen. Truncated portion of VP2 protein (tVP2) of CPV-2 was selected on the basis of antigenic indices, overexpressed the recombinant protein in E. coli system and was subsequently used in development of LAT. A total of 59 serum samples obtained from vaccinated (n = 54) and healthy unvaccinated (n = 5) dogs were tested. The positivity was observed in 85% (46/54) of these dogs with varying agglutination pattern. The overall sensitivity and specificity of latex agglutination test in comparison to HI test was recorded as 90% and 88% respectively with an agreement value of 90% (CI = 95%). Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

  19. Green synthesis of colloidal silver nanoparticles using natural rubber latex extracted from Hevea brasiliensis.

    Science.gov (United States)

    Guidelli, Eder José; Ramos, Ana Paula; Zaniquelli, Maria Elisabete D; Baffa, Oswaldo

    2011-11-01

    Colloidal silver nanoparticles were synthesized by an easy green method using thermal treatment of aqueous solutions of silver nitrate and natural rubber latex (NRL) extracted from Hevea brasiliensis. The UV-Vis spectra detected the characteristic surface plasmonic absorption band around 435 nm. Both NRL and AgNO(3) contents in the reaction medium have influence in the Ag nanoparticles formation. Lower AgNO(3) concentration led to decreased particle size. The silver nanoparticles presented diameters ranging from 2 nm to 100 nm and had spherical shape. The selected area electron diffraction (SAED) patterns indicated that the silver nanoparticles have face centered cubic (fcc) crystalline structure. FTIR spectra suggest that reduction of the silver ions are facilitated by their interaction with the amine groups from ammonia, which is used for conservation of the NRL, whereas the stability of the particles results from cis-isoprene binding onto the surface of nanoparticles. Therefore natural rubber latex extracted from H. brasiliensis can be employed in the preparation of stable aqueous dispersions of silver nanoparticles acting as a dispersing and/or capping agent. Moreover, this work provides a new method for the synthesis of silver nanoparticles that is simple, easy to perform, pollutant free and inexpensive. Copyright © 2011 Elsevier B.V. All rights reserved.

  20. Rubber elongation factor (REF, a major allergen component in Hevea brasiliensis latex has amyloid properties.

    Directory of Open Access Journals (Sweden)

    Karine Berthelot

    Full Text Available REF (Hevb1 and SRPP (Hevb3 are two major components of Hevea brasiliensis latex, well known for their allergenic properties. They are obviously taking part in the biosynthesis of natural rubber, but their exact function is still unclear. They could be involved in defense/stress mechanisms after tapping or directly acting on the isoprenoid biosynthetic pathway. The structure of these two proteins is still not described. In this work, it was discovered that REF has amyloid properties, contrary to SRPP. We investigated their structure by CD, TEM, ATR-FTIR and WAXS and neatly showed the presence of β-sheet organized aggregates for REF, whereas SRPP mainly fold as a helical protein. Both proteins are highly hydrophobic but differ in their interaction with lipid monolayers used to mimic the monomembrane surrounding the rubber particles. Ellipsometry experiments showed that REF seems to penetrate deeply into the monolayer and SRPP only binds to the lipid surface. These results could therefore clarify the role of these two paralogous proteins in latex production, either in the coagulation of natural rubber or in stress-related responses. To our knowledge, this is the first report of an amyloid formed from a plant protein. This suggests also the presence of functional amyloid in the plant kingdom.

  1. A system for treatment of diabetic foot ulcers using led irradiation and natural latex

    Directory of Open Access Journals (Sweden)

    Gustavo Adolfo Marcelino de Almeida Nunes

    Full Text Available Abstract Introduction: We developed and tested a new system for inducing the healing of diabetic foot ulcers. The system relies on the regenerative properties of its two components: an insole with a sheet of natural latex and a device that contains a matrix of light emitting diodes with wavelength of 635 nm. Methods The electronic and latex based devices were developed, and a four weeks test was performed in one control group (CG of five ulcers and one experimental group (EG of eight ulcers. The CG was treated with a standard approach, based on a silver-releasing foam dressing, and the EG was treated with the system under test. For each ulcer, an index for quantifying the percentage ulcer recovery, named CRU(%, has been calculated; a CRU(% = 0% means no healing, and a CRU(% = 100% means total healing. Results There were statistically significant increases of CRU(% of 51.8% (p = 0.022, for the CG, and of 78.4% (p < 0.001, for the EG. The increase in the EG was higher than the increase in the CG, and the difference was statistically significant (p < 0.001. The results showed that the proposed method had, for these particular sets of ulcers, faster healing rates, than for the standard method. Conclusion The results hint that the proposed method seems promising as a future treatment method. However, the technique must undergo further testing before it can be considered for extensive clinical applications.

  2. Properties and Characterization of Kenaf-Filled Natural Rubber Latex Foam

    Directory of Open Access Journals (Sweden)

    Ahmad Fikri Abdul Karim

    2015-12-01

    Full Text Available Kenaf powder was incorporated with natural rubber latex (NRL compound and foamed to make natural rubber latex foam (NRLF by using a well known technique called the Dunlop method. Different loadings of kenaf powder were added to NRL compound and was foamed to make NRLF. The mechanical properties, density, compression, thermal, and micro-structural characterization of control NRLF and kenaf incorporated NRLF were studied. Increasing content of kenaf reduced the tensile strength, elongation at break, and compressive strength of a NRLF. Modulus at 100% elongation and density of the NRLF increased with an increase in filler loading. Higher kenaf loading indicated higher elasticity of kenaf-filled NRLF, but the recovery percentage of kenaf-filled NRLF decreased with increasing kenaf loading. From thermogravimetric analysis (TGA result, an increase in the amount of kenaf loading from 1 to 7 phr increased the thermal stability of kenaf-filled NRLF. Morphological and micro-structural characterization performed by using scanning electron microscopy (SEM showed that kenaf powder filled up the micro-sized pores in the open cell structure of kenaf-filled NRLF.

  3. Euphorbia heterophylla L.

    African Journals Online (AJOL)

    SARAH

    30 sept. 2015 ... dans l'alimentation des lapins (Oryctolagus cuniculus L.) dont la récolte non contrôlée des ... Effect of Guinea grass (Panicum maximum Jacq.) associated with ..... fed to Guinea pigs in periurban rearing systems of Kinshasa.

  4. Radio-vulcanization of natural rubber in the latex phase. Study of an experimental 1 tonne per hour production; Radio-vulcanisation du caoutchouc naturel en phase latex. Etude d'une production experimentale de 1 tonne par heure

    Energy Technology Data Exchange (ETDEWEB)

    Leveque, P; Puig, J R; Roudeix, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    After briefly reviewing the main research carried out on the radio-vulcanization of latex and elastomers, a description is given of 4 types of cell which have been used successively with a view to industrial irradiation. They have made it possible to acquire the information necessary for resolving the main problem arising during irradiation - the formation of coagulum. The first two cell are designed for irradiation by a horizontal beam ('Dynamitron'), the two others use a vertical beam ('Circe'). The study of the properties of the rubber obtained shows it to compare favorably with 'Revultex'. In the appendix are given some characteristics of natural latex and information about its processing. (authors) [French] Apres un rappel des principales etudes sur la radio-vulcanisation du latex et des elastomeres, on decrit les quatre types de cellules successivement essayes en vue de l'irradiation industrielle. Ils ont permis d'acquerir les informations necessaires a la resolution du probleme principal pose par l'irradiation, la formation de coagulum au cours de celle,-ci. Les deux premiers sont concus pour l'irradiation par un faisceau horizontal ('Dynamitron'), les derniers par un faisceau vertical ('Circe'). L'etude des proprietes du caoutchouc obtenu montre qu'il se compare favorablement au 'Revultex'. Un apercu est donne en annexe des caracteristiques du latex naturel et de sa mise en oeuvre. (auteurs)

  5. Composite poly(methyl methacrylate-methacrylic acid-2-hydroxyethyl methacrylate) latex for immunoassay. The case of plasminogen.

    Science.gov (United States)

    Miksa, B; Wilczynska, M; Cierniewski, C; Basinska, T; Slomkowski, S

    1995-01-01

    Poly(methyl methacrylate-methacrylic acid-2-hydroxyethyl methacrylate) latex (ACRYLAT) was synthesized by radical precipitation polymerization. The mass median diameter (MMD) and the geometrical standard deviation (GSD) of the ACRYLAT particles were 138 nm and 1.2, respectively. The concentration of the titrable carboxylic groups in the surface layer of latex particles was equal to 8.41 x 10(-6) mol m-2. Latex was able to bind up to 2.82 x 10(-7) mol of 1-aminopyrene per 1 m2 of the surface of the latex particles due to the ionic interactions between carboxylate anions and ammonium cations of protonated 1-aminopyrene. ACRYLAT was able to immobilize covalently human serum albumin in amounts up to 0.23 mg m-2. Aggregation of ACRYLAT with immobilized HSA, induced with specific antibodies (anti-HSA), was investigated turbidimetrically. The results indicated that in the model turbidimetric immunoassay, ACRYLAT coated with HSA can be used for the detection of anti-HSA in the goat anti-HSA serum diluted from 50 to 7000-fold. Immobilization of rabbit antibodies to plasminogen (anti-Plg) to ACRYLAT via the epsilon-aminocaproic acid linkers provided particles which were used for the development of the turbidimetric immunoassay for plasminogen. In this assay plasminogen could be detected in concentration ranging from 0.75 to 75 micrograms ml-1 in the blood plasma.

  6. Sequencing and characterization of asclepain f: the first cysteine peptidase cDNA cloned and expressed from Asclepias fruticosa latex.

    Science.gov (United States)

    Trejo, Sebastián A; López, Laura M I; Caffini, Néstor O; Natalucci, Claudia L; Canals, Francesc; Avilés, Francesc X

    2009-07-01

    Asclepain f is a papain-like protease previously isolated and characterized from latex of Asclepias fruticosa. This enzyme is a member of the C1 family of cysteine proteases that are synthesized as preproenzymes. The enzyme belongs to the alpha + beta class of proteins, with two disulfide bridges (Cys22-Cys63 and Cys56-Cys95) in the alpha domain, and another one (Cys150-Cys201) in the beta domain, as was determined by molecular modeling. A full-length 1,152 bp cDNA was cloned by RT-RACE-PCR from latex mRNA. The sequence was predicted as an open reading frame of 340 amino acid residues, of which 16 residues belong to the signal peptide, 113 to the propeptide and 211 to the mature enzyme. The full-length cDNA was ligated to pPICZalpha vector and expressed in Pichia pastoris. Recombinant asclepain f showed endopeptidase activity on pGlu-Phe-Leu-p-nitroanilide and was identified by PMF-MALDI-TOF MS. Asclepain f is the first peptidase cloned and expressed from mRNA isolated from plant latex, confirming the presence of the preprocysteine peptidase in the latex.

  7. Dynamics of polyelectrolyte adsorption and colloidal flocculation upon mixing studied using mono-dispersed polystyrene latex particles

    NARCIS (Netherlands)

    Feng, Lili; Cohen Stuart, Martien; Adachi, Yasuhisa

    2015-01-01

    The dynamic behavior of polyelectrolytes just after their encounter with the surface of bare colloidal particles is analyzed, using the flocculation properties of mono-dispersed polystyrene latex (PSL) particles. Applying a Standardized Colloid Mixing (SCM) approach, effects of ionic strength and

  8. Diagnosis of Trichomonous vaginalis by microscopy, latex agglutination, diamond's media, and PCR in symptomatic women, Khartoum, Sudan.

    Science.gov (United States)

    Saleh, Amir M; Abdalla, Hamid S; Satti, Abdelsalam B; Babiker, Suad M; Gasim, Gasim I; Adam, Ishag

    2014-03-06

    Trichomoniasis is the most common sexually transmitted disease. However, limited data are available on an effective technique for the diagnosis of Trichomonas vaginalis. A cross-sectional study was conducted to evaluate the accuracy of wet mount microscopy, latex agglutination, Diamond's media, and polymerase chain reaction (PCR) for detection of T. vaginalis among symptomatic women who attended the gynecological clinic at Khartoum, Sudan. Of the 297 women studied, 252 (84.8%) were positive for T. vaginalis by wet mount microscopy, 257 (86.5%) by latex agglutination, 253 (85.2%) by Diamond's media, and 253 (85.2%) by PCR. The sensitivity and specificity of wet mount microscopy were 99.2% and 97.7%, respectively, compared with PCR. The sensitivity and specificity of latex agglutination and Diamond's media were 99.6% and 88.6%, and 100.0% and 86.4%, respectively, compared with PCR. In this study, wet mount microscopy, latex agglutination, and Diamond's media were found to be highly sensitive and specific. However, the availability and cost effectiveness might limit the use of Diamond's media and PCR in routine practice. The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7859723851211496.

  9. Dragon Fruit Foliage Plant-Based Coagulant for Treatment of Concentrated Latex Effluent: Comparison of Treatment with Ferric Sulfate

    Directory of Open Access Journals (Sweden)

    Juferi Idris

    2013-01-01

    Full Text Available The effectiveness of dragon fruit foliage as a natural coagulant for treatment of concentrated latex effluent was investigated and compared with ferric sulfate, a chemical coagulant. Dragon fruit is a round and often red-colored fruit with scales-like texture and is native to south American countries which is also cultivated and heavily marketed in southeast Asian countries. Its foliage represents a part of its overall plant system. Latex effluent is one of the main byproduct from rubber processing factories in Malaysia. Three main parameters investigated were chemical oxygen demand (COD, suspended solids (SS, and turbidity of effluent. Coagulation experiments using jar test were performed with a flocculation system where the effects of latex effluent pH as well as coagulation dosage on coagulation effectiveness were examined. The highest recorded COD, SS, and turbidity removal percentages for foliage were observed for effluent pH 10 at 94.7, 88.9, and 99.7%, respectively. It is concluded that the foliage showed tremendous potential as a natural coagulant for water treatment purposes. The foliage could be used in the pretreatment stage of Malaysian latex effluent prior to secondary treatment.

  10. Detection of latex allergens by immunoelectron microscopy in ambient air (PM10) in Oslo, Norway (1997-2003).

    Science.gov (United States)

    Namork, Ellen; Kurup, Viswanath P; Aasvang, Gunn Marit; Johansen, Bjørn V

    2004-11-01

    The authors collected ambient air along two highways in Oslo to investigate the annual variations in particulate matter (PM10) and the presence of latex as an outdoor allergen. PMI, was monitored for a period of five years, during which time the use of studded winter tires was reduced. The presence of latex and of common aeroallergens was examined directly on the collection filters with immunoelectron microscopy visualized in a scanning electron microscope. The annual variation in PM10 was similar over the five years of sampling, with increased mass concentrations in winter. Statistical analysis indicated no major effect from the change to nonstudded tires. The most important factors influencing the PM10 concentration were meteorological parameters like wind and rain. Immnunolabeling of the filters showed latex as an outdoor allergen that adhered to carbon aggregates from vehicle emission. The results also indicated cross-reactive epitopes among the common allergens investigated, which for sensitized subjects may add to the risk of developing latex allergy.

  11. The patatin-like protein from the latex of Hevea brasiliensis (Hev b 7) is not a vacuolar protein

    NARCIS (Netherlands)

    Jekel, PA; Hofsteenge, J; Beintema, JJ

    Upon centrifugation, rubber latex is divided into a layer of rubber particles, the cytosol, and the lutoid-body fraction, which is of vacuolar origin. One of the proteins isolated from the lutoid-body fraction is a protein with a molecular mass of 43 kDa, which has esterase activity on

  12. Banyan latex: a facile fuel for the multifunctional properties of MgO nanoparticles prepared via auto ignited combustion route

    International Nuclear Information System (INIS)

    Anil Kumar, M R; Nagaswarupa, H P; Gurushantha, K; Pratapkumar, C; Prashantha, S C; Shashishekar, T R; Anantharaju, K S; Nagabhushana, H; Sharma, S C; Vidya, Y S; Daruka Prasad, B; Vivek Babu, C S; Vishnu Mahesh, K R

    2015-01-01

    MgO nanoparticles (MNPs) were prepared by a solution combustion route using banyan tree (BT) latex and glycine as fuels. The powder x-ray diffraction results indicate the formation of a single cubic phase and the crystallite size obtained from transmission electron microscopy was found to be ∼10–15 nm. Scanning electron microscopy result reveals spherical-shaped particles obtained with BT latex. However, in a chemical route, porous and agglomerated particles were obtained. The energy band gap of MNPs obtained using BT latex and a chemical route were found to be in the range 4.85–5.0 eV. Photoluminescence peaks observed at 473, 514, and 588 nm when excited at 433 nm, which were attributed to surface defects. The enhanced photocatalytic activities of spherical MgO were due to smaller crystallite size, higher surface defects, dye sensitization, and capability to reduce the electron–hole pair recombination. Further, green-synthesized MNPs exhibit superior antifungal activity against various plant pathogens. The present studies demonstrated a green engineering route for the synthesis of multifunctional MNPs using BT latex. (paper)

  13. Barrier and adhesion properties of anti-corrosion coatings based on surfactant-free latexes from anhydride-containing polymers

    NARCIS (Netherlands)

    Soer, W.J.; Ming, W.; Koning, C.E.; Benthem, van R.A.T.M.; Mol, J.M.C.; Terryn, H.

    2009-01-01

    We have successfully obtained surfactant-free latexes from anhydride-containing polymers, including poly(styrene-alt-maleic anhydride) (PSMA), maleinized polybutadiene (PBDMA), and poly(octadecene-alt-maleic anhydride) (POMA). Here we report barrier and adhesion properties of the coatings made from

  14. Sulfonated macro-RAFT agents for the surfactant-free synthesis of cerium oxide-based hybrid latexes

    NARCIS (Netherlands)

    Garnier, J.; Warnant, J.; Lacroix-Desmazes, P.; Dufils, P.E.; Vinas, J.; Herk, van A.M.

    2013-01-01

    Three types of amphiphatic macro-RAFT agents were employed as compatibilizers to promote the polymerization reaction at the surface of nanoceria for the synthesis of CeO2-based hybrid latexes. Macro-RAFT copolymers and terpolymers were first synthesized employing various combinations of butyl

  15. Enzymic and structural studies on processed proteins from the vacuolar (lutoid-body) fraction of latex of Hevea brasiliensis

    NARCIS (Netherlands)

    Subroto, T; de Vries, H; Schuringa, JJ; Soedjanaatmadja, UMS; Hofsteenge, J; Jekel, PA; Beintema, JJ

    2001-01-01

    The lutoid-body (bottom) fraction of latex from the rubber tree (Hevea brasiliensis) contains a limited number of major proteins. These are the chitin-binding protein hevein, its precursor and C-terminal fragment of the precursor, a basic chitinase/lysozyme, and a beta-1,3-glucanase. The content and

  16. Effect of Hevea brasiliensis latex sap gel on healing of acute skin wounds induced on the back of rats

    Directory of Open Access Journals (Sweden)

    Maria Vitória Carmo Penhavel

    Full Text Available Objective : to evaluate the effect of topical delivery of latex cream-gel in acute cutaneous wounds induced on the back of rats. Methods : we subjected sixteen rats to dermo-epidermal excision of a round dorsal skin flap, with 2.5cm diameter. We divided the animals into two groups: Latex Group: application of cream-gel-based latex throughout the wound bed on postoperative days zero, three, six and nine; Control group: no treatment on the wound. Photographs of the lesions were taken on the procedure day and on the 6th and 14th postoperative days, for analyzing the area and the larger diameter of the wound. We carried out euthanasia of all animals on the 14th postoperative day, when we resected he dorsal skin and the underlying muscle layer supporting the wound for histopathological study. Results : there was no statistically significant difference in the percentage of wound closure, in the histopathological findings or in the reduction of the area and of the largest diameter of the wounds among the groups studied on the 14th postoperative day. Conclusion : according to the experimental conditions in which the study was conducted, latex cream-gel did not interfere in the healing of acute cutaneous wounds in rats.

  17. Latex Allergy

    Science.gov (United States)

    American Academy of Allergy Asthma & Immunology Menu Search Main navigation Skip to content Conditions & Treatments Allergies Asthma Primary Immunodeficiency Disease Related Conditions Drug Guide Conditions Dictionary Just ...

  18. Latex Allergy

    Science.gov (United States)

    ... Conditions Drug Guide Conditions Dictionary Just for Kids Library School Tools Videos Virtual Allergist Education & Training Careers in ... Support the AAAAI Foundation Donate Utility navigation Español Journals Annual Meeting Member Login / My Membership Search navigation ...

  19. Latex Allergy

    Science.gov (United States)

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  20. Mechanical and Permeability Characteristics of Latex-Modified Pre-Packed Pavement Repair Concrete as a Function of the Rapid-Set Binder Content

    Directory of Open Access Journals (Sweden)

    Jae-Woong Han

    2015-10-01

    Full Text Available We evaluated the strength and durability characteristics of latex-polymer-modified, pre-packed pavement repair concrete (LMPPRC with a rapid-set binder. The rapid-set binder was a mixture of rapid-set cement and silica sand, where the fluidity was controlled using a latex polymer. The resulting mix exhibited a compressive strength of ¥21 MPa and a flexural strength of ¥3.5 MPa after 4 h of curing (i.e., the traffic opening term for emergency repairs of pavement. The ratio of latex polymer to rapid-set binder material was varied through 0.40, 0.33, 0.29, and 0.25. Mechanical characterization revealed that the mechanical performance, permeability, and impact resistance increased as the ratio of latex polymer to rapid-set binder decreased. The mixture exhibited a compressive strength of ¥21 MPa after 4 h when the ratio of latex polymer to rapid-set binder material was ¤0.29. The mixture exhibited a flexural strength of ¥3.5 MPa after 4 h when the ratio of latex polymer to rapid-set binder material was ¤0.33. The permeability resistance to chloride ions satisfied 2000 C after 7 days of curing for all ratios. The ratio of latex polymer to rapid-set binder material that satisfied all conditions for emergency pavement repair was ¤0.29.

  1. Detection and toxicity assessment of nitrosamines migration from latex gloves in the Chinese market.

    Science.gov (United States)

    Feng, Di; Wang, Huiping; Cheng, Xuelian; Wang, Jiedong; Ning, Lifeng; Zhou, Qingfeng; Zhou, Yue; Yang, Quanli

    2009-09-01

    Nitrosamines are potent carcinogens and have been found in latex products. In 2007, twenty-seven natural latex gloves including sterile gloves, examination gloves and household use gloves were sampled from the Chinese market. This study monitored the migration of nitrosamines and nitrosatable substance from these gloves, and evaluated their mutagenicity using a Salmonella typhimurium mutation assay (Ames assay) with the strains TA98, TA97, TA100 and TA102 and by a micronucleus test (MN test) using ICR mice. In addition, the cytotoxicity of these compounds was determined by a MTT assay. N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA) and N-nitrosodibutylamine (NDBA) were all found in samples treated with artificial sweat for 4h at 37 degrees C, and total nitrosamines varied from 18.89 to 244.51microg/Kg. The nitrosamine mixture of NDMA, NDEA and NDBA was used in both the Ames assay and the MN test. The proportion of NDMA, NDEA and NDBA (1:10:20) was selected according to the proportion of nitrosamines migration from sample E05. In the Ames assay, the lowest dose (1.98 x 10(-3)microg per plate) produced a positive result in the TA98 strain, corresponding to nitrosamines migration from sample E05 of 0.016g (the total nitrosamines migration from glove E05 was 122.55 microg/kg). The TA100 strain responded positively at a dose of 4.96 x 10(-2)microg per plate, corresponding to nitrosamines migration from glove E05 of 0.040g. The MN test showed nitrosamine migration of 3.04 mg from 2066 pairs of sample E05 and could induce micronuclei in one mouse weighing 28g (average weight of one E05 glove was 6g). Extracts from gloves were found to be cytotoxic and there was a significant correlation between cytotoxicity (IC50) and the release level of nitrosamines. In conclusion, in view of the high content of nitrosamines in latex gloves and the potential toxicity of nitrosamines migration from these gloves, it is suggested that both an effective and feasible detection

  2. Type I allergy to natural rubber latex and type IV allergy to rubber chemicals in health care workers with glove-related skin symptoms.

    Science.gov (United States)

    Nettis, E; Assennato, G; Ferrannini, A; Tursi, A

    2002-03-01

    It has been established that there are type I and type IV allergens in latex gloves. The purpose of the study was to establish the prevalence of rubber glove-induced skin symptoms among health care workers in one Italian hospital. Health care workers (n = 1584) were evaluated using a written questionnaire and 295 respondents with glove-induced skin symptoms were tested. We performed: skin prick test with latex glove extract and commercial latex, and environmental and food allergens; glove use test; patch tests with a rubber additive series; and RASTs. Hospital employees who used or had used latex gloves at work were 1294. Three hundred and sixteen (24.4%) reported glove-induced symptoms, namely, cutaneous symptoms in all the cases and non-cutaneous symptoms in 105 subjects (8.1%). Twenty-seven of the 295 symptomatic employees tested (9.1%) were latex sensitive. Thirty-one patients (10.5%) exhibited positive patch test to rubber-related allergens. The most positive readings were obtained from the Thiuram mix and the Carba mix, with 12 and 9 positivities, respectively. The risk factors for latex skin sensitization were: a previous history of atopy and asthma; history of surgery; pre-existing hand dermatitis; work-related symptoms; and positive skin tests to common inhalant and certain foods (P skin complaints of latex gloves are related to skin irritation rather than to allergy. The immediate allergy to latex and the delayed allergy to rubber chemicals suggest that all the health care workers with glove-related dermatitis should undergo both skin prick test and glove use test to detect type I hypersensitivity to latex, and patch test to detect type IV hypersensitivity to rubber chemicals.

  3. Preparation and Characterization of Conducting Polymer Latices by Chemical Polymerization of Aniline or Anisidine in Presence of Latex: Study of Their Electroactivity and Anti-Corrosion Properties

    Directory of Open Access Journals (Sweden)

    Bakhshali Massoumi

    2013-06-01

    Full Text Available Poly (vinylacetate-co-butylmethacrylate was prepared in presence of potassium persulphate as an oxidizing agent in aqueous solution of dodecylbenzene sulfonate sodium as an emulsifying agent. Then, aniline was polymerized by chemical oxidation method at three different concentrations of aniline monomer (0.1, 0.2 and 0.3 M in toluene in presence of poly(vinylacetate-co-butylmethacrylate in order to obtain polyaniline/poly(vinylacetate-co-butylmethacrylate. To prepare conducting-latex of polyanisidine/poly(vinylacetate-co-butylmethacrylate the same method was employed as above for aniline monomer in obtaining conducting polyaniline/poly(vinylacetate-co-butylmethacrylate latex. In addition, the purification of conducting-latex polymers, polyaniline/poly(vinylacetate-co-butylmethacrylate and polyanisidine/poly(vinylacetate-co-butylmethacrylate was conducted and preparation of tin layer films of conducting-latex polymers was carried out by casting method on glassy lames. The electroactivity properties of the prepared latex-polymers, polyaniline/poly(vinylacetate-co-butylmethacrylate and polyanisidine/poly(vinylacetate-co-butylmethacrylate were investigated by cyclic voltammetery (CV. The voltamogrames showed that the latex films were electroactive. Because of conductivity and electroactivity, the obtained films may find applications in anti-corrosion coatings. The anti-corrosion properties of conducting-latex polymers were studied on aluminum surface by impedance technique. The structure of the prepared conducting-latex polymers was confirmed by Fourier transform infrared (FTIR. Finally, the electrical conductivity of synthesized conducting-latex polymers, polyaniline/poly(vinylacetate-co-butylmethacrylate and polyanisidine/poly(vinylacetate-co-butylmethacrylate was measured by four probe technique.

  4. Study of the effect of ionizing radiation on the structure of natural rubber latex by positron annihilation technique

    International Nuclear Information System (INIS)

    Lopez Saldana, I.R.

    1993-01-01

    At the present research, were studied the changes in natural rubber latex structure, due to electron beam by a 3 MeV, 25 m A Dynamitron electron accelerator. The natural rubber latex was irradiated at 30, 40 and 50 kGy/s dose rate, over a total dose range from 150 to 250 kGy, for each dose rate used. From natural rubber latex irradiated films were prepared by casting with 0.7 mm. thickness. In the main part, the study was made by positron annihilation lifetime (PAL), this technique is unique in the determination of free-volume properties due to the fact that positronium atom (Ps) is found to be preferentially localized in the free-volume region of polymeric materials. The positron lifetime measurements were performing using a gamma-gamma coincidence system. These results were analyzed by PATFIT-88 program computer into three components, the long-lived component for orthopositronium (o-Ps) with parameters lifetime (τ 3 ) and formation intensity (I 3 ), were plotted and analyzed for each dose rate and total dose used. Besides with τ 3 were calculated the mean free-volume size based on the spherical model for the free-volume bubble, found that the free-volume decrease slightly with the total dose due to the crosslinking of natural rubber latex. Besides was studied the effect of dose rate on tensile strength, the tensile strength is increased with the total dose although there was not a clear effect due to the dose rate. Also the films were subjected to aging in order to determined the thermal stability of natural rubber latex irradiated, the results show that the films have good stability. Besides was used the infrared spectroscopy to determine the changes due to the crosslinking by variations in the characteristically absorption bands for cis 1,4-polyisoprene. (Author)

  5. Preparation of magnetic latexes functionalized with chloromethyl groups via emulsifier-free miniemulsion polymerization

    International Nuclear Information System (INIS)

    Faridi-Majidi, Reza; Sharifi-Sanjani, Naser

    2007-01-01

    Functionalized crosslinked polystyrene-co-divinylbenzene-co-chloromethylstyrene magnetic latex particles were prepared via emulsifier-free miniemulsion polymerization using 2, 2' azobis (2-amidinopropane) dihydrochloride (V-50) as an initiator and in the presence of magnetite nanoparticles in the monomers. Transmission electron microscopy (TEM) proved the presence of magnetite nanoparticles in polymer particles. Differential scanning calorimetery (DSC) analysis of the product showed an exothermic signal due to crosslinking of chains through electrophilic aromatic substitution of phenyl groups with chloromethyl groups in the presence of the dispersed Fe 3 O 4 as Lewis acid. This was proven by thermogravimetric analysis (TGA) via the loss of gaseous HCl. The results were also compared with those of magnetite-free miniemulsion polymerization using V-50

  6. Preparation of magnetic latexes functionalized with chloromethyl groups via emulsifier-free miniemulsion polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Faridi-Majidi, Reza [School of Chemistry, University College of Science, Tehran University, Tehran (Iran, Islamic Republic of)]. E-mail: refaridi@khayam.ut.ac.ir; Sharifi-Sanjani, Naser [School of Chemistry, University College of Science, Tehran University, Tehran (Iran, Islamic Republic of)

    2007-04-15

    Functionalized crosslinked polystyrene-co-divinylbenzene-co-chloromethylstyrene magnetic latex particles were prepared via emulsifier-free miniemulsion polymerization using 2, 2' azobis (2-amidinopropane) dihydrochloride (V-50) as an initiator and in the presence of magnetite nanoparticles in the monomers. Transmission electron microscopy (TEM) proved the presence of magnetite nanoparticles in polymer particles. Differential scanning calorimetery (DSC) analysis of the product showed an exothermic signal due to crosslinking of chains through electrophilic aromatic substitution of phenyl groups with chloromethyl groups in the presence of the dispersed Fe{sub 3}O{sub 4} as Lewis acid. This was proven by thermogravimetric analysis (TGA) via the loss of gaseous HCl. The results were also compared with those of magnetite-free miniemulsion polymerization using V-50.

  7. Antifungal activity of fluconazole-loaded natural rubber latex against Candida albicans.

    Science.gov (United States)

    Yonashiro Marcelino, Mônica; Azevedo Borges, Felipe; Martins Costa, Ana Flávia; de Lacorte Singulani, Junya; Ribeiro, Nathan Vinícius; Barcelos Costa-Orlandi, Caroline; Garms, Bruna Cambraia; Soares Mendes-Giannini, Maria José; Herculano, Rondinelli Donizetti; Fusco-Almeida, Ana Marisa

    2018-03-01

    This work aimed to produce a membrane based on fluconazole-loaded natural rubber latex (NRL), and study their interaction, drug release and antifungal susceptibility against Candida albicans. Fluconazole-loaded NRL membrane was obtained by casting method. The Fourier Transform Infrared Spectroscopy showed no modifications either in NRL or fluconazole after the incorporation. Mechanical test presented low Young's modulus and high strain, indicating the membranes have sufficient elasticity for biomedical application. The bio-membrane was able to release the drug and inhibit the growth of C. albicans as demonstrated by disk diffusion and macrodilution assays. The biomembrane was able to release fluconazole and inhibit the growth of C. albicans, representing a promising biomaterial for skin application.

  8. Formation of protein complex with the aid of polyethylene glycol for deproteinized natural rubber latex

    Science.gov (United States)

    Wei, Lim Keuw; Ing, Wong Kwee; Badri, Khairiah Haji; Ban, Wong Chong

    2013-11-01

    The effect of polyethylene glycol (PEG) as a deproteinizing agent in commercial natural rubber latex (NRL) onto the physicochemical properties of the NRL was investigated. Three types of PEG were used namely PEG200, PEG4000 and PEG20000 (molecular weight of 200, 4000 and 20000 g/mol respectively). The optimum amount of PEG in NRL was determined from viscosity changes, protein content and Fourier Transform Infrared spectroscopy. Level of protein reduction was affected by molecular weight of PEG. The addition of PEG in NRL reduced the protein content of NRL (3.30 %) to the lowest (2.01 %) at 0.40 phr of PEG200 due to more attractive hydrophobic interactions between short chains PEG compared to PEG4000 (2.24%) and PEG20000 (2.15%). This was verified through FTIR spectroscopy analysis by observing the primary and secondary amide peak where PEG4000 has lesser absorption at the region compared to with PEG20000.

  9. Diclofenac Potassium Transdermal Patches Using Natural Rubber Latex Biomembranes as Carrier

    Directory of Open Access Journals (Sweden)

    Natan Roberto de Barros

    2015-01-01

    Full Text Available The aim of this study was to design a compound transdermal patch containing diclofenac potassium (Dic-K using natural rubber latex (NRL biomembrane. The NRL from Hevea brasiliensis is easily manipulated and low cost and presents high mechanical resistance. It is a biocompatible material which can stimulate natural angiogenesis and is capable of adhering cells on its surface. Recent researches have used the NRL for Transdermal Drug Delivery Systems (TDDSs. Dic-K is used for the treatment of rheumatoid arthritis and osteoarthritis and pain relief for postoperative and posttraumatic cases, as well as inflammation and edema. Results showed that the biomembrane can release Dic-K for up to 216 hours. The kinetics of the Dic-K release could be fitted with double exponential function. X-ray diffraction and Fourier Transform Infrared (FTIR spectroscopy show some interaction by hydrogen bound. The results indicated the potential of the compound patch.

  10. Characteristic of natural rubber latex-methyl metha-crylate copolymer in mineral lubricant base oil

    International Nuclear Information System (INIS)

    Meri Suhartini; Rahmawati

    2010-01-01

    Natural rubber latex-methyl methacrylate copolymer was diluted in xylene, then diluted in four types of lubricant base oil with concentrations of 0.25%, 1%, 5%, and 10%. The mixed solutions were analyzed to obtain kinematics viscosity, viscosity index, density, ash content, metal content, flash point, shear stability and total alkali number. The viscosity index of sample, increased by adding the copolymer solution. The results showed that lubricant base oil of High Viscosity index (HVI) 60 and mixed HVI 60: HVI 650 gave optimum viscosity index. The higher concentration of polymer added into base lubricant oil, the higher viscosity index obtained. The shear stability test showed that the kinematics viscosity of sample decreased 6.5% after 60 minutes of treatment test. (author)

  11. Production and testing of 244Cm-labeled fluorescent polystyrene latex microspheres

    International Nuclear Information System (INIS)

    Guilmette, R.A.; Mueller, H.L.; Brodbeck, R.D.

    1988-01-01

    To provide a useful tool for studying the mechanisms of retention and translocation of respirable-sized, alpha-emitting particles, we have developed a method of incorporating 244 Cm into fluorescent polystyrene latex microspheres. The resultant particles contain alpha radioactivity comparable to μm-size (AMAD) 239 Pu0 2 particles, but are easily visible by fluorescent light microscopy. Preliminary testing of the particles with dog macrophages in vitro has shown that the initial uptake of these Cm-labeled particles is more rapid than uptake of unlabeled particles of similar size. We are continuing to develop procedures for achieving better particle yields, smaller dispersity of particle size distributions and improved retention of the Cm label by the particles. (author)

  12. Production and testing of {sup 244}Cm-labeled fluorescent polystyrene latex microspheres

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R A; Mueller, H L; Brodbeck, R D

    1988-12-01

    To provide a useful tool for studying the mechanisms of retention and translocation of respirable-sized, alpha-emitting particles, we have developed a method of incorporating {sup 244}Cm into fluorescent polystyrene latex microspheres. The resultant particles contain alpha radioactivity comparable to {mu}m-size (AMAD) {sup 239}Pu0{sub 2} particles, but are easily visible by fluorescent light microscopy. Preliminary testing of the particles with dog macrophages in vitro has shown that the initial uptake of these Cm-labeled particles is more rapid than uptake of unlabeled particles of similar size. We are continuing to develop procedures for achieving better particle yields, smaller dispersity of particle size distributions and improved retention of the Cm label by the particles. (author)

  13. Co-coagulation of the NBR latex and clay aqueous suspension: preparation and characterization

    International Nuclear Information System (INIS)

    Reis, Raquel S.; Brum, Elisson; Silva, Vanessa M.; Souza, Diego H.S.; Gomes, Ailton de S.; Nunes, Regina C.R.

    2009-01-01

    Blends of nitrile rubber (NBR) and sodium montmorillonite (MMT-Na) were prepared by co-coagulation of the NBR latex with aqueous suspension of clay. The content of MMT was varied from 0 to 7 phr and different mixtures were analyzed by X-ray diffraction, light scattering, gel content, thermogravimetric analysis and the oscillating disk rheometer. The different methods used indicated that there was formation of a structure interspersed in the mixtures studied, and that increasing the content MMT-Na enhances the values obtained. Rheological measurements on compositions with NBR showed the influence of clay on increasing the time of healing in terms of its content, as is the gel content and the thermal resistance. All results were compared to composition of NBR without MMT. (author)

  14. Fluorescent Labeling and Biodistribution of Latex Nanoparticles Formed by Surfactant-Free RAFT Emulsion Polymerization.

    Science.gov (United States)

    Poon, Cheuk Ka; Tang, Owen; Chen, Xin-Ming; Kim, Byung; Hartlieb, Matthias; Pollock, Carol A; Hawkett, Brian S; Perrier, Sébastien

    2017-10-01

    The authors report the preparation of a novel range of functional polyacrylamide stabilized polystyrene nanoparticles, obtained by surfactant-free reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization, their fluorescent tagging, cellular uptake, and biodistribution. The authors show the versatility of the RAFT emulsion process for the design of functional nanoparticles of well-defined size that can be used as drug delivery vectors. Functionalization with a fluorescent tag offers a useful visualization tool for tracing, localization, and clearance studies of these carriers in biological models. The studies are carried out by labeling the sterically stabilized latex particles chemically with rhodamine B. The fluorescent particles are incubated in a healthy human renal proximal tubular cell line model, and intravenously injected into a mouse model. Cellular localization and biodistribution of these particles on the biological models are explored. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Composite Films Formed by Cellulose nanocrystals and Latex Nanoparticles: Optical, Structural, and Mechanical Properties

    Science.gov (United States)

    Vollick, Brandon McRae

    This thesis describes the preparation of iridescent, birefringent, composite films composed of cellulose nanocrystals (CNCs), latex nanoparticles (NPs) and a NP crosslinker; hexanediamine (HDA). First, aqueous suspensions were prepared with varying quantities of CNCs, NPs and HDA before equilibrating for one week. The cholesteric (Ch) phase was then cast and dried into a film. The optical, structural and mechanical properties of the film was analyzed. Second, films with identical compositions of CNCs, NPs, and HDA were fabricated in three different ways to yield films of different morphology, (i) fast drying of an isotropic suspension, yielding an isotropic film, (ii) slow drying of an isotropic suspension, yielding a partially Ch films, (iii) slow drying of an equilibrated suspension, yielding a highly Ch film. The optical and mechanical properties of the films was analyzed.

  16. Toxicological evaluation of natural rubber latex film vulcanized with ionizing radiation

    International Nuclear Information System (INIS)

    Campos, Vania E.; Higa, Olga Z.; Guedes, Selma M.L.; Hanada, Seico

    1999-01-01

    The industrial vulcanization of natural rubber latex (NRL) is made worldwide by conventional process using sulphur, but it can be made by an alternative process using ionizing radiation. The main advantages of this process are related to absence of toxic effect promoted by chemical substances added to the NRL on the conventional process. In this research was tested the toxicological properties of the films vulcanized by the alternative process in relation to that vulcanized by the conventional process. The toxicity was evaluated by in vitro cytotoxicity assay and in vivo systemic toxicity assay. The results showed that vulcanized films by gamma ray are less cytotoxic. The systemic toxicity assay showed that only the vulcanized film using sulphur induced allaying and motor in coordination on the animals for a short period of time. these results evidence the less cytotoxic properties of vulcanized films by gamma ray in relation to that vulcanized by conventional process using sulphur. (author)

  17. Latex content and biomass increase in Mycorrhizal guayule (Parthenium argentatum) under field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Bloss, H.E.; Pfeiffer, C.M.

    1984-01-01

    Guayule seedlings were inoculated with two Glomus species in pasteurised soil and grown in the glasshouse without added fertilizer for 8 weeks prior to transplanting to the field. The survival rate of transplanted guayule seedlings was increased by inoculation with vesicular arbuscular mycorrhizal fungi compared wtih uninoculated controls. Inoculated guayule had greater concentrations of Ca, Fe, Mg and Mn at six months of age, and greater concentrations of Ca, Mg, and Zn at 12 months of age than did uninoculated plants. The latex content of both roots and shoots of guayule was greater in inoculated than in uninoculated guayule plants at 12 and 18 months of age. The resin content remained unchanged between treatments irrespective of sampling date.

  18. Properties of natural rubber/attapulgite composites prepared by latex compounding method: Effect of filler loading

    International Nuclear Information System (INIS)

    Muttalib, Siti Nadzirah Abdul; Othman, Nadras; Ismail, Hanafi

    2015-01-01

    This paper reports on the effect of filler loading on properties of natural rubber (NR)/attapulgite (ATP) composites. The NR/ATP composites were prepared by latex compounding method. It is called as masterbatch. The masterbatch was subsequently added to the NR through melt mixing process. The vulcanized NR/ATP composites were subjected to mechanical, swelling and morphological tests. All the results were compared with NR/ATP composites prepared by conventional system. The composites from masterbatch method showed better results compared to composites prepared by conventional method. They have higher tensile properties, elongation at break and tear strength. The images captured through scanning electron microscopy test revealed the improvement of tensile strength in masterbatch NR/ATP composites. It can be seen clearly that masterbatch NR/ATP have better filler dispersion compared to conventional method NR/ATP composites

  19. Properties of natural rubber/attapulgite composites prepared by latex compounding method: Effect of filler loading

    Energy Technology Data Exchange (ETDEWEB)

    Muttalib, Siti Nadzirah Abdul, E-mail: sitinadzirah.amn@gmail.com; Othman, Nadras, E-mail: srnadras@usm.my; Ismail, Hanafi, E-mail: ihanafi@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Seri Ampangan, 14300 Nibong Tebal, Pulau Pinang (Malaysia)

    2015-07-22

    This paper reports on the effect of filler loading on properties of natural rubber (NR)/attapulgite (ATP) composites. The NR/ATP composites were prepared by latex compounding method. It is called as masterbatch. The masterbatch was subsequently added to the NR through melt mixing process. The vulcanized NR/ATP composites were subjected to mechanical, swelling and morphological tests. All the results were compared with NR/ATP composites prepared by conventional system. The composites from masterbatch method showed better results compared to composites prepared by conventional method. They have higher tensile properties, elongation at break and tear strength. The images captured through scanning electron microscopy test revealed the improvement of tensile strength in masterbatch NR/ATP composites. It can be seen clearly that masterbatch NR/ATP have better filler dispersion compared to conventional method NR/ATP composites.

  20. Enhancement of sludge granulation in anaerobic treatment of concentrated latex wastewater

    Directory of Open Access Journals (Sweden)

    Nugul Intrasungkha

    2008-04-01

    Full Text Available Recently, the upflow anaerobic sludge blanket (UASB reactor has become attractive for wastewater treatment with low energy requirement and biogas production. However, the start-up of an UASB reactor depends on the formation of granules. Therefore, this research aims to study the effect of AlCl3, CaCl2 and temperature on the granule formation process using real concentrated latex wastewater. The result shows that the optimum chemicals concentration of AlCl3 at 300 mg/l enhanced the biomass accumulation and sludge formation process. Approximately 50% of large granular size (0.5 mm 0.8 mm within 35 days, whereas the large granular sizes in reactorwithout AlCl3 supplement (R2 became visible within 63 days. Moreover, this experiment found that R1, R2 and R3 could reach steady state within 40, 55 and 45 days, respectively.