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Sample records for du 2-ethylhexyl nitrate

  1. Biodegradation of 2-ethylhexyl nitrate by Mycobacterium austroafricanum IFP 2173; Biodegradation du 2-ethylhexyl nitrate par Mycobacterium austroafricanum IFP 2173

    Energy Technology Data Exchange (ETDEWEB)

    Nicolau, E

    2008-10-15

    Compounds such as 2-ethylhexyl nitrate (2-EHN) are added to diesel fuel to improve ignition and boost cetane number. The production of 2-EHN reaches around 100000 tons per year in France, principally. Risks associated to its utilization are however poorly known because, in case of accidental release in the environment, nothing is known about its biodegradation. In this study, we aimed at (i) identifying bacterial strains able to degrade 2-EHN and compare their capabilities, (ii) elucidating the degradation pathway, and (iii) identifying the enzymes involved. Biodegradation of 2-EHN was first tested in biphasic cultures under conditions that reduce the toxicity and increase the availability of the hydrophobic substrate. Using optimized culture conditions, we showed that several strains of Mycobacterium austroafricanum were able to degrade 2-EHN. One of the most efficient strain (IFP 2173) which could grow at 2-EHN concentrations up to 6 g.L{sup -1}, was chosen to investigate the degradation pathway. On the basis of carbon balance determination and gas chromatographic (GC) analysis on the culture medium, I found that the degradation of 2-EHN was incomplete and gave rise to the accumulation of a metabolite. This metabolite was identified as {beta}-methyl-{gamma}-butyrolactone by GC-MS and LC-MS/MS analysis. The structure of the lactone indicated that 2-EHN was degraded through a pathway involving the hydroxylation of the methyl group of the main carbon chain, its oxidation into aldehyde an acid and a subsequent cycle of b-oxidation. Enzymes involved in the 2-EHN biodegradation pathway were looked for by a proteomic approach. Analyses by two-dimensional gel electrophoresis showed that, when exposed to 2-EHN, strain IFP 2173 triggered the synthesis of a bunch of enzymes specialized in fatty acid metabolism such as {beta}-oxidation enzymes, as well as alcohol and aldehyde dehydrogenases. An exhaustive analysis of the IFP 2173 proteome resulted in the identification of

  2. Biodegradation of 2-ethylhexyl nitrate by Mycobacterium austroafricanum IFP 2173

    International Nuclear Information System (INIS)

    Nicolau, E.

    2008-10-01

    Compounds such as 2-ethylhexyl nitrate (2-EHN) are added to diesel fuel to improve ignition and boost cetane number. The production of 2-EHN reaches around 100000 tons per year in France, principally. Risks associated to its utilization are however poorly known because, in case of accidental release in the environment, nothing is known about its biodegradation. In this study, we aimed at (i) identifying bacterial strains able to degrade 2-EHN and compare their capabilities, (ii) elucidating the degradation pathway, and (iii) identifying the enzymes involved. Biodegradation of 2-EHN was first tested in biphasic cultures under conditions that reduce the toxicity and increase the availability of the hydrophobic substrate. Using optimized culture conditions, we showed that several strains of Mycobacterium austroafricanum were able to degrade 2-EHN. One of the most efficient strain (IFP 2173) which could grow at 2-EHN concentrations up to 6 g.L -1 , was chosen to investigate the degradation pathway. On the basis of carbon balance determination and gas chromatographic (GC) analysis on the culture medium, I found that the degradation of 2-EHN was incomplete and gave rise to the accumulation of a metabolite. This metabolite was identified as β-methyl-γ-butyrolactone by GC-MS and LC-MS/MS analysis. The structure of the lactone indicated that 2-EHN was degraded through a pathway involving the hydroxylation of the methyl group of the main carbon chain, its oxidation into aldehyde an acid and a subsequent cycle of b-oxidation. Enzymes involved in the 2-EHN biodegradation pathway were looked for by a proteomic approach. Analyses by two-dimensional gel electrophoresis showed that, when exposed to 2-EHN, strain IFP 2173 triggered the synthesis of a bunch of enzymes specialized in fatty acid metabolism such as β-oxidation enzymes, as well as alcohol and aldehyde dehydrogenases. An exhaustive analysis of the IFP 2173 proteome resulted in the identification of more than 200

  3. 78 FR 6213 - Styrene-2-Ethylhexyl Acrylate Copolymer; Tolerance Exemption

    Science.gov (United States)

    2013-01-30

    ...This regulation establishes an exemption from the requirement of a tolerance for residues of 2-propenoic acid, 2-ethylhexyl ester, polymer with ethenylbenzene; also known as styrene-2-ethylhexyl acrylate copolymer when used as an inert ingredient in a pesticide chemical formulation. H. B. Fuller Company submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting an exemption from the requirement of a tolerance. This regulation eliminates the need to establish a maximum permissible level for residues of 2-propenoic acid, 2-Ethylhexyl Ester, Polymer with Ethenylbenzene on food or feed commodities.

  4. Solvent extraction of uranyl nitrate (1962); Extraction du nitrate d'uranyle par solvant (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Talmont, X; Regnaut, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Durandet, J; Renault, Ph; Gladel, Y L [Institut Francais du Petrole (IFP), Dept. de Physico-Chimie Appliquee, 92 - Rueil-Malmaison (France)

    1962-07-01

    The transfer of uranyl nitrate from an aqueous acid phase into a solvent (dilute tributylphosphate) is attended by nitric acid transfer. In these conditions, equilibrium data cannot be represented by a plane curve, which complicates the determination of the efficiency of the extractor used, i.e. the calculation of either the number of theoretical plates or the number of transfer units equivalent to the apparatus. The authors are presenting a simple method for estimating the efficiency of a column, based upon either uranium or acid transfer. This method can be used when the profile of uranium and acid concentrations in a phase circulating in the equipment bas been previously determined. On another hand, it enables to study the variation of local efficiency, i.e. the efficiency of different sections of the column. (authors) [French] Le transfert du nitrate d'uranyle d'une phase aqueuse acide dans un solvant (phosphate de tributyle dilue) s'accompagne d'un transfert d'acide nitrique. Dans ces conditions, les donnees d'equilibre ne sont pas representees par une courbe plane, ce qui complique la determination de l'efficacite de l'extracteur utilise, c'est-a-dire le calcul, soit du nombre d'etages theoriques, soit du nombre d'unites de transfert auquel l'appareil est equivalent. Les auteurs presentent une methode simple d'evaluation de l'efficacite d'une colonne basee, soit sur le transfert d'uranium, soit sur celui d'acide. Cette methode est utilisable lorsqu'en a determine au prealable le profil des concentrations en uranium et en acide d'une phase circulant dans l'appareil. Elle permet, d'autre part, d'etudier la variation de l'efficacite locale, c'est-a-dire l'efficacite de differentes sections de la colonne. (auteurs)

  5. Synthesis of Estolide 2-ethylhexyl Ester from Ricinus communis

    International Nuclear Information System (INIS)

    Nazrizawati Ahmad Tajuddin; Nor Habibah Rosli

    2013-01-01

    Estolide 2-ethylhexyl ester synthesized through condensation reaction between ricinoleic acid from castor oil (Ricinus communis) and lauric acid, and then capped with 2-ethylhexyl alcohol. The reaction was continuously conducted under vacuum for 24 hours. Product of 2-ethylhexyl ester was characterized by using Fourier Transform Infrared (FTIR) to determine functional group and Nuclear Magnetic Resonans (NMR) for structure's determination. The presence of ester group at 1738.23 cm -1 wavenumber indicates that the formation of estolide ester has occurred. The vibration peak of C-O at 1174.60 cm -1 and 1117.10 cm -1 support the formation of ester. The presence of CH 2 bending indicated the long-chain compound. The ester methine signal at 3.8669 ppm indicated the estolide linkage in the 1 H-NMR spectrum while the 13 C-NMR showed two carbonyl signals at 173.41 ppm for acid and 173.56 ppm for ester. (author)

  6. Antiandrogenic effects in male rats perinatally exposed to a mixture of di(2-ethylhexyl) phthalate and di(2-ethylhexyl) adipate

    DEFF Research Database (Denmark)

    Jarfelt, K.; Dalgaard, M.; Hass, Ulla

    2005-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a well-known testicular toxicant inducing adverse effects in androgen responsive tissues. Therefore, di(2-ethylhexyl) adipate (DERA) is currently being evaluated as a potential substitute for DEHP. Similarities in structure and metabolism of DERP and DEHA have...... in the reproductive system than males receiving DERP alone. (c) 2004 Elsevier Inc. All rights reserved.......) and retention of nipples in male offspring were found in all three exposed groups. Dosed males exhibited decreased weights of ventral prostate and m. levator ani/bulbocavernosus. Histopathological investigations revealed alterations in testis morphology in both juvenile and adult animals. The litter size...... was decreased and postnatal mortality was increased in the combination group only, which is likely a combined effect of DEHP and DEHA. However, no combination effect was seen with respect to antiandrogenic effects, as males receiving DEHP in combination with DEHA did not exhibit more pronounced effects...

  7. Obtention of Samarium and Gadolinium concentrates by solvent extraction using mono-2-ethylhexyl ester of 2-ethylhexyl phosphonic acid

    International Nuclear Information System (INIS)

    Miranda Junior, Pedro

    1996-01-01

    The rare earth chlorides solution employed in this study, which is constituted by medium and heavy fractions, is derived from monazite processing accomplished by NUCLEMON-Mineroquimica (SP). This solution shows an acidity about 1.18 M and 189 g/L of rare earth oxides, containing as main constituents: Sm(34.55%), Gd(23.85%), Dy (6.82%), and Y (24.45%). It was used, as organic phase, 2-ethylhexyl phosphonic acid, mono-2-ethylhexylester diluted to 1 M in isododecane. (author)

  8. Impacts de l'Enherbement du Vignoble Alsacien sur le Transfert des Nitrates.

    OpenAIRE

    TOURNEBIZE , Julien

    2001-01-01

    Encadrante: Caroline GREGOIRE; The water quality of the Alsacian aquifer degrades principally because of nitrates. This pollution originates partly from the vineyard situated in the Piemont area of the Vosges massif which is a preferential zone of aquifer recharge. The main objective of the Enherbement du Vignoble Alsacien (EVA) project is to quantify the impact of an agri-environmental technique : to put grass in one out of two vine inter rows. The methodology of this work is based on the as...

  9. A chromophoric study of 2-ethylhexyl p-methoxycinnamate

    Science.gov (United States)

    Alves, Leonardo F.; Gargano, Ricardo; Alcanfor, Silvia K. B.; Romeiro, Luiz A. S.; Martins, João B. L.

    2011-11-01

    Ultraviolet absorption spectra of 2-ethylhexyl p-methoxycinnamate have been recorded in different solvents and calculated using the time dependent density functional theory. The calculations were performed with the aid of B3LYP, PBE1PBE, M06, and PBEPBE functionals and 6-31+G(2d) basis set. The geometries were initially optimized using PM5 semiempirical method for the conformational search. The calculations of excited states were carried out using the time dependent with IEF-PCM solvent reaction field method. The experimental data were obtained in the wavelength range from 200 to 400 nm using 10 different solvents. The TD-PBE1PBE method shows the best agreement to the experimental results.

  10. Toxic Effects of Di-2-ethylhexyl Phthalate: An Overview

    Directory of Open Access Journals (Sweden)

    Sai Sandeep Singh Rowdhwal

    2018-01-01

    Full Text Available Di-2-ethylhexyl phthalate (DEHP is extensively used as a plasticizer in many products, especially medical devices, furniture materials, cosmetics, and personal care products. DEHP is noncovalently bound to plastics, and therefore, it will leach out of these products after repeated use, heating, and/or cleaning of the products. Due to the overuse of DEHP in many products, it enters and pollutes the environment through release from industrial settings and plastic waste disposal sites. DEHP can enter the body through inhalation, ingestion, and dermal contact on a daily basis, which has raised some concerns about its safety and its potential effects on human health. The main aim of this review is to give an overview of the endocrine, testicular, ovarian, neural, hepatotoxic, and cardiotoxic effects of DEHP on animal models and humans in vitro and in vivo.

  11. Extraction of niobium and tantalum with bis-2-ethylhexyl acetamide

    International Nuclear Information System (INIS)

    Ohmori, Hiroshi; Shibata, Junji; Sano, Makoto; Nishimura, Sanji

    1986-01-01

    Extraction of Nb and Ta from acid solutions with bis-2-ethylhexyl acetamide and stripping of these metals with sulphuric acid solutions were investigated. The organic phase was a binary solution of bis-2-ethylhexyl acetamide and xylene, while the aqueous phase was composed of hydrofluoric acid solution or hydrofluoric-sulphuric acid solution containing 3.5 - 13 kg/m 3 Nb and 5 - 10 kg/m 3 Ta. Sulphuric acid, hydrochloric acid and nitric acid were used as salting out agents to understand the effect on the extraction. Both metals were not sufficiently extracted from hydrofluoric acid solutions, whereas the extraction of both metals remarkably increased with an addition of sulphuric acid to the aqueous phase. The separation factor decreased with an increase in the concentration of hydrofluoric acid at the constant sulphuric acid concentration of 5.8N, and both metals were completely coextracted in the aqueous condition of 6N hydrofluoric acid and 8N sulphuric acid. The stripping occurred for both metals with a high efficiency, when water or dilute sulphuric acid solution was used as a stripping agent. The increase in sulphuric acid concentration caused less stripping of Ta, while the stripping of Nb was maintained at 80 % up to 7N sulphuric acid. The separation factor reached the maximum with the value of 116 in the use of 6.5N sulphuric acid. The extraction behavior of Fe(II), Fe(III), Sn(IV) and Mn(II) was also examined with the results that these metals were not extracted even to the extent of the lowest limit of atomic absorption spectrophotometer. Moreover, the comparison of this extractant with MIBK and TBP, which were in common use, was carried out. (author)

  12. Di-(2-ethylhexyl) phthalate and mono-(2-ethylhexyl) phthalate inhibit growth and reduce estradiol levels of antral follicles in vitro

    International Nuclear Information System (INIS)

    Gupta, Rupesh K.; Singh, Jeffery M.; Leslie, Tracie C.; Meachum, Sharon; Flaws, Jodi A.; Yao, Humphrey H-C

    2010-01-01

    Any insult that affects survival of ovarian antral follicles can cause abnormal estradiol production and fertility problems. Phthalate esters (PEs) are plasticizers used in a wide range of consumer and industrial products. Exposure to these chemicals has been linked to reduced fertility in humans and animal models. Di-(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) decrease serum estradiol levels and aromatase (Arom) expression, prolong estrous cycles, and cause anovulation in animal and culture models. These observations suggest PEs directly target antral follicles. We therefore tested the hypothesis that DEHP (1-100 μg/ml) and MEHP (0.1-10 μg/ml) directly inhibit antral follicular growth and estradiol production. Antral follicles from adult mice were cultured with DEHP or MEHP, and/or estradiol for 96 h. During culture, follicle size was measured every 24 h as a measurement of follicle growth. After culture, media were collected for measurement of estradiol levels and follicles were subjected to measurement of cylin-D-2 (Ccnd2), cyclin-dependant-kinase-4 (Cdk4), and Arom. We found that DEHP and MEHP inhibited growth of follicles and decreased estradiol production compared to controls at the highest doses. DEHP and MEHP also decreased mRNA expression of Ccnd2, Cdk4, and Arom at the highest dose. Addition of estradiol to the culture medium prevented the follicles from DEHP- and MEHP-induced inhibition of growth, reduction in estradiol levels, and decreased Ccnd2 and Cdk4 expression. Collectively, our results indicate that DEHP and MEHP may directly inhibit antral follicle growth via a mechanism that partially includes reduction in levels of estradiol production and decreased expression of cell cycle regulators.

  13. Critical cleaning agents for Di-2-ethylhexyl sebacate.

    Energy Technology Data Exchange (ETDEWEB)

    Hartley, Mya; Archuleta, Kim M.

    2013-08-01

    It is required that Di-2-ethylhexyl Sebacate oil, also commonly known as Dioctyl Sebacate oil, be thoroughly removed from certain metals, in this case stainless steel parts with narrow, enclosed spaces. Dioctyl Sebacate oil is a synthetic oil with a low compressibility. As such, it is ideally used for high pressure calibrations. The current method to remove the Dioctyl Sebacate from stainless steel parts with narrow, enclosed spaces is a labor-intensive, multi-step process, including a detergent clean, a deionized (DI) water rinse, and several solvent rinses, to achieve a nonvolatile residue of 0.04 mg per 50 mL rinse effluent. This study was undertaken to determine a superior detergent/solvent cleaning method for the oil to reduce cleaning time and/or the amount of detergent/solvent used. It was determined that while some detergent clean the oil off the metal better than the current procedure, using only solvents obtained the best result. In addition, it can be inferred, based on elevated temperature test results, that raising the temperature of the oil-contaminated stainless steel parts to approximately 50ÀC will provide for improved cleaning efficacy.

  14. Solvent Extraction of Rare Earths by Di-2 Ethylhexyl Phosphoric Acid

    International Nuclear Information System (INIS)

    Srinuttrakul, Wannee; Kranlert, Kannika; Kraikaew, Jarunee; Pongpansook, Surasak; Chayavadhanangkur, Chavalek; Kranlert, Kannika

    2004-10-01

    Solvent extraction has been widely applied for individual rare earth separation because the separation time is rapid and a large quantity of products is obtained. In this work, this technique was utilized to extract mixed rare earths, obtained from monazite digestion process. Di-2-ethylhexyl phosphoric acid (D2EHPA) was used as an extractant. The factors affected the extraction including HNO 3 concentration in mixed rare earth nitrate solution and the amount of D2EHPA were studied. The appropriate concentrations of HNO 3 and D2EHPA were found to be 0.01 and 1.5 M, respectively. From the result of equilibrium curve study, it was observed that heavy rare earths were extracted more efficient than light rare earths. A 6-stage continuous countercurrent solvent extraction was simulated for rare earth extraction. The optimum ratio of solvent to feed solution (S/F) was 2. Because of the high cost of D2EHPA, 1.0 M of D2EHPA was suitable for the rare earth extraction by the continuous countercurrent solvent extraction

  15. Di-(2-Ethylhexyl Phthalate and Autism Spectrum Disorders

    Directory of Open Access Journals (Sweden)

    Chiara Testa

    2012-04-01

    Full Text Available ASDs (autism spectrum disorders are a complex group of neurodevelopment disorders, still poorly understood, steadily rising in frequency and treatment refractory. Extensive research has been so far unable to explain the aetiology of this condition, whereas a growing body of evidence suggests the involvement of environmental factors. Phthalates, given their extensive use and their persistence, are ubiquitous environmental contaminants. They are EDs (endocrine disruptors suspected to interfere with neurodevelopment. Therefore they represent interesting candidate risk factors for ASD pathogenesis. The aim of this study was to evaluate the levels of the primary and secondary metabolites of DEHP [di-(2-ethylhexyl phthalate] in children with ASD. A total of 48 children with ASD (male: 36, female: 12; mean age: 11 ± 5 years and age- and sex-comparable 45 HCs (healthy controls; male: 25, female: 20; mean age: 12 ± 5 years were enrolled. A diagnostic methodology, based on the determination of urinary concentrations of DEHP metabolites by HPLC-ESI-MS (HPLC electrospray ionization MS, was applied to urine spot samples. MEHP [mono-(2-ethylhexenyl 1,2-benzenedicarboxylate], 6-OH-MEHP [mono-(2-ethyl-6-hydroxyhexyl 1,2-benzenedicarboxylate], 5-OH-MEHP [mono-(2-ethyl-5-hydroxyhexyl 1,2-benzenedicarboxylate] and 5-oxo-MEHP [mono-(2-ethyl-5-oxohexyl 1,2-benzenedicarboxylate] were measured and compared with unequivocally characterized, pure synthetic compounds (>98% taken as standard. In ASD patients, significant increase in 5-OH-MEHP (52.1%, median 0.18 and 5-oxo-MEHP (46.0%, median 0.096 urinary concentrations were detected, with a significant positive correlation between 5-OH-MEHP and 5-oxo-MEHP (r s=0.668, P<0.0001. The fully oxidized form 5-oxo-MEHP showed 91.1% specificity in identifying patients with ASDs. Our findings demonstrate for the first time an association between phthalates exposure and ASDs, thus suggesting a previously unrecognized role for

  16. Pu-Th separation studies employing di(2-ethylhexyl)isobutyramide (D2EHIBA) as extractant from nitric acid medium

    International Nuclear Information System (INIS)

    Pathak, P.N.; Prabhu, D.R.; Rizvi, G.H.; Ruikar, P.B.; Kumbhare, L.B.; Mohapatra, P.K.; Manchanda, V.K.

    2003-01-01

    An attempt has been made to explore the use of di(2-ethylhexyl)isobutyramide (D2EHIBA) as an extractant for the recovery of Pu from the (proposed) AHWR fuel fabrication scrap solution. The extraction of Pu in the hexavalent state has been found to be distinctly more efficient than that in the tetravalent state. Distribution studies have been carried out by maintaining Pu as Pu(VI) employing AgO as the oxidant. Scrubbing at 5 M HNO 3 has been proposed to reduce the interference due to the co-extracted Th(IV). Quantitative stripping of the extracted Pu was achieved using hydroxyl ammonium-nitrate (HAN) as reductant. Ion exchange studies have been carried out for the final purification of Pu. It is proposed to employ the cation exchanger, Biorad AG 50X8 for the final purification of Pu from the stripped solution, keeping Pu as Pu(III). (orig.)

  17. Batch Simulation of Rare Earths Extractive Separation by Di (2-Ethylhexyl) Phosphoric Acid and Tributylphosphate in Kerosene

    International Nuclear Information System (INIS)

    Kraikaew, Jarunee; Srinuttakul, Wanee

    2004-01-01

    Liquid-liquid extraction is applied to separate individual rare earths. In this research, 6-stage continuous countercurrent solvent extraction was simulated to extract rare earths from rare earth nitrate solution, which was obtained from monazite processing, to estimate the possible optimum operating conditions for pilot or industrial plants. The solvent(S) per feed(F) ratio (S/F) was varied from 1 to 3. The organic are 1.0 and 1.5 Molars (M) Di (2-ethylhexyl) phosphoric acid (D2EHPA) in kerosene. 50% tributylphosphate (TBP) in kerosene was applied for comparison. It was found that D2EHPA was a good extracting agent for heavy rare earths while TBP extracted well both light and heavy rare earths. After extraction with TBP and D2EHPA, the extraction efficiency at solvent per feed ratio (S/F) =2 and 3 showed a slight difference. S/F =2 was selected commercially for operation

  18. Study of the solubility of plutonyl nitrate with a view to its extraction by a solvent; Etude de la solubilite du nitrate de plutonyle en vue de son extraction par solvant

    Energy Technology Data Exchange (ETDEWEB)

    Vergnaud, G. [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

    1965-09-01

    The research covers the determination of the partition coefficient of plutonyl nitrate and their application to the industrial treatment of plutonium. The solvent used is a tri-n-butyl phosphate solution diluted to 30 per cent in dodecane. The parameters which have been studied and which can affect the extraction of the plutonyl nitrate are: the plutonyl nitrate concentration; the nitric acid concentration; the uranyl nitrate concentration; the tetravalent plutonium nitrate concentration. The industrial application has been studied using a battery of mixer-separators. The operational conditions are defined in the case of a conventional plutonium separation plant. The results obtained, for a higher plutonyl nitrate concentration than that actually planned, are satisfactory and encouraging as far as the operation is concerned. Only the presence of polymerized tetravalent plutonium can adversely affect the satisfactory extraction of the plutonium. (author) [French] L'etude porte sur les coefficients de partage du nitrate de plutonyle et leur application a l'elaboration industrielle du plutonium. Le solvant utilise est une solution de phosphate de tri-n-butyle, dilue a 30 pour cent dans le dodecane. Les parametres etudies et pouvant influencer l'extraction du nitrate de plutonyle, par ce solvant, sont: concentration du nitrate de plutonyle; concentration de l'acide nitrique; concentration du nitrate d'uranyle; concentration au nitrate de plutonium tetravalent. L'application industrielle est etudiee au moyen d'une batterie de melangeurs-decanteurs. Les conditions operatoires sont definies d'apres un schema classique d'usine de separation de plutonium. Les resultats obtenus, pour une concentration du nitrate de plutonyle superieure a celle reellement prevue, sont satisfaisants et encourageants pour l'exploitation. Seule, la presence de plutonium tetraralent polymerise, peut nuire a une bonne extraction du plutonium

  19. Study of the solubility of plutonyl nitrate with a view to its extraction by a solvent; Etude de la solubilite du nitrate de plutonyle en vue de son extraction par solvant

    Energy Technology Data Exchange (ETDEWEB)

    Vergnaud, G [Commissariat a l' Energie Atomique, Fontenay aux Roses (France). Centre d' Etudes Nucleaires

    1965-09-01

    The research covers the determination of the partition coefficient of plutonyl nitrate and their application to the industrial treatment of plutonium. The solvent used is a tri-n-butyl phosphate solution diluted to 30 per cent in dodecane. The parameters which have been studied and which can affect the extraction of the plutonyl nitrate are: the plutonyl nitrate concentration; the nitric acid concentration; the uranyl nitrate concentration; the tetravalent plutonium nitrate concentration. The industrial application has been studied using a battery of mixer-separators. The operational conditions are defined in the case of a conventional plutonium separation plant. The results obtained, for a higher plutonyl nitrate concentration than that actually planned, are satisfactory and encouraging as far as the operation is concerned. Only the presence of polymerized tetravalent plutonium can adversely affect the satisfactory extraction of the plutonium. (author) [French] L'etude porte sur les coefficients de partage du nitrate de plutonyle et leur application a l'elaboration industrielle du plutonium. Le solvant utilise est une solution de phosphate de tri-n-butyle, dilue a 30 pour cent dans le dodecane. Les parametres etudies et pouvant influencer l'extraction du nitrate de plutonyle, par ce solvant, sont: concentration du nitrate de plutonyle; concentration de l'acide nitrique; concentration du nitrate d'uranyle; concentration au nitrate de plutonium tetravalent. L'application industrielle est etudiee au moyen d'une batterie de melangeurs-decanteurs. Les conditions operatoires sont definies d'apres un schema classique d'usine de separation de plutonium. Les resultats obtenus, pour une concentration du nitrate de plutonyle superieure a celle reellement prevue, sont satisfaisants et encourageants pour l'exploitation. Seule, la presence de plutonium tetraralent polymerise, peut nuire a une bonne extraction du plutonium. (auteur)

  20. Equilibrium Studies on the Extraction of Yttrium from Chloride Medium by Mono (2-Ethylhexyl) 2-Ethylhexyl Phosphonic Acid (Ion quest 801)

    International Nuclear Information System (INIS)

    Zaki, E.E.; Ismail, Z.H.; Aly, H.F.; Sabet, S.A.

    2008-01-01

    Since 90 Y is one of the useful radioisotopes in nuclear medicine, liquid-liquid extraction of yttrium from chloride medium has been studied under various conditions using neutralized and un-neutralized mono (2-ethylhexyl) 2-ethylhexyl phosphonic acid (EHEHPA) as an extractant. Effect of reagent concentration, ph of the aqueous medium, metal ion concentration and nature of the diluent on the extraction process has been carried out. Effect of temperature was studied and thermodynamic parameters were evaluated. Yttrium extracted in organic phase was stripped with various reagents. The stoichiometry of the extracted species of yttrium was determined on the basis of slope analysis of experimental results. Equilibrium equations of the extraction process have been estimated and verified

  1. Supercritical fluid extraction of uranium and neodymium nitrates

    International Nuclear Information System (INIS)

    Sujatha, K.; Sivaraman, N.; Srinivasan, T.G.; Vasudeva Rao, P.R.

    2011-01-01

    Supercritical fluid extraction (SFE) of uranyl nitrate and neodymium nitrate salts from a mixture was investigated in the present study using Sc-CO 2 modified with various ligands such as organophosphorous compounds, amides, and diketones. Preferential extraction of uranyl nitrate over neodymium nitrate was demonstrated using Sc-CO 2 modified with amide, di-(2ethylhexyl) isobutyramide (D2EHIBA). (author)

  2. Fabrication of thorium nitrate at the factory at the Bouchet; Fabrication du nitrate de thorium pur a l'usine du Bouchet

    Energy Technology Data Exchange (ETDEWEB)

    Braun, C; Lorrain, Ch; Mahut, R; Mariette, R; Muller, J; Prugnard, J [Commissariat a l' Energie Atomique, Usine du Bouchet, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    A urano-thorianite mineral from Madagascar is industrially treated at the factory of the Bouchet in order to obtain pure thorium in the form of the nitrate and a uranium concentrate in the form of uranate. The required factory was designed and constructed in 1955 and 1956 by the firm Potasse et Engrais Chimiques (P.E.C.) on behalf of the French Atomic Energy authority. The mineral which has previously undergone a gravimetric sorting and enrichment at the mine, is in the form of a heavy rock (the density can be as high as 10), having a cubic structure. It consists principally of a mixture of thorium oxide and uranium oxide and contains between 50 and 75 per cent thorium and between 5 and 20 per cent of uranium. On the same sample a high content in either thorium or uranium in general corresponds to a low content in the other of the two metals; this rule is not however always obeyed absolutely. Among other elements present we shall only mention the Pb, Fe, Ce, Ra and other radioactive elements, since their presence influences the treatment of the mineral. We shall first briefly describe the process, which has already been described in previous publications, we consider to be worthy of attention. (author)Fren. [French] Le minerai d'uranothorianite en provenance de Madagascar est traite industriellement a l'Usine du Bouchet en vue de l'obtentionn sel de thorium pur, le nitrate, et d'un concentre d'uranium, un uranate. L'etude et la construction de l'atelier destine a cet effet ont ete realisees en 1955 et 1956 par la Societe Potasse et Engrais chimiques pour le Commissariat a l'Energie atomique. Le minerai, scheide ou enrichi a la mine par voie gravimetrique, se presente comme une roche dense (la densite peut atteindre 10), de structure cubique. Il est constitue essentiellement d'un melange d'oxyde de thorium et d'oxyde d'uranium qui titre 50 a 75 pour cent de Th et 5 a 20 pour cent d'uranium. A une forte teneur d'un element correspond dans le meme minerai une basse

  3. Green Synthesis of Ultraviolet Absorber 2-Ethylhexyl Salicylate: Experimental Design and Artificial Neural Network Modeling

    Directory of Open Access Journals (Sweden)

    Shang-Ming Huang

    2017-11-01

    Full Text Available 2-Ethylhexyl salicylate, an ultraviolet filter, is widely used to protect skin against sunlight-induced harmful effects in the cosmetic industry. In this study, the green synthesis of 2-ethylhexyl salicylate using immobilized lipase through a solvent-free and reduced pressure evaporation system was investigated. A Box–Behnken design was employed to develop an artificial neural network (ANN model. The parameters for an optimal architecture of an ANN were set out: a quick propagation algorithm, a hyperbolic tangent transfer function, 10,000 iterations, and six nodes within the hidden layer. The best-fitting performance of the ANN was determined by the coefficient of determination and the root-mean-square error between the correlation of predicted and experimental data, indicating that the ANN displayed excellent data-fitting properties. Finally, the experimental conditions of synthesis were well established with the optimal parameters to obtain a high conversion of 2-ethylhexyl salicylate. In conclusion, this study efficiently replaces the traditional solvents with a green process for the synthesis of 2-ethylhexyl salicylate to avoid environmental contamination, and this process is well-modeled by a methodological ANN for optimization, which might be a benefit for industrial production.

  4. UV-absorbing and other sun-protecting substances: genotoxicity of 2-ethylhexyl P-methoxycinnamate.

    Science.gov (United States)

    Bonin, A M; Arlauskas, A P; Angus, D S; Baker, R S; Gallagher, C H; Greenoak, G; Brown, M M; Meher-Homji, K M; Reeve, V

    1982-11-01

    The mutagenicity of 2-ethylhexyl p-methoxycinnamate was demonstrated when 25 sunscreen ingredients were tested in the Salmonella/microsome assay. This substance also increased the frequency of sex-linked recessive lethals in Drosophila melanogaster. A trace contaminant may be implicated because many samples were obtained from several sources and the results were batch-related.

  5. Hydrophobic Materials Based on Salts of Di(2-ethylhexyl)phosphoric Acid

    Science.gov (United States)

    Kizim, N. F.; Golubina, E. N.

    2018-03-01

    Interfacial formations of material based on metals di(2-ethylhexyl)phosphates of various metals exhibit hydrophobic properties. The contact angle of the surface, modified by the interfacial formations materials, could reach up to 140° depending on the nature of the solvent, the metal salt, the number of applications.

  6. Dose Reconstruction of Di-2-Ethylhexyl Phthalate Using a Simple Pharmacokinetic Model [Manuscript

    Science.gov (United States)

    Background In 2005, eight adults provided full volumes and times of urine voids during one normal work week. These samples were analyzed for four di-2-ethylhexyl phthalate (DEHP) metabolites. Participants also provided diary information on their diet, driving, and out¬door a...

  7. Tissue distribution and excretion of tri-(2-ethylhexyl)trimellitate in rats

    International Nuclear Information System (INIS)

    Martis, L.; Woods, F.E.

    1987-01-01

    The disposition kinetics of tri-(2-ethylhexyl)trimellitate (TEHTM), a new plasticizer for polyvinyl chloride (PVC) plastic, was studied in rats following intravenous administration of [ 14 C-carbonyl]tri-(2-ethylhexyl)trimellitate using an oil in water emulsion as the vehicle. The distribution half-life, elimination half-life, and clearance values estimated from the plasma concentration of radioactivity data obtained following iv administration of 10.5 mg/kg of TEHTM (59.9 μCi/kg), were 46.2 min, 5.34 d, and 40.5 ml/kg x h, respectively. Following iv dosage of 15.6 mg/kg of TEHTM (28.0 μCi/kg), significant accumulation of radioactivity was found in the liver, lungs, and spleen, with liver accounting for 72% of the administered dosage at 24. Excretion of TEHTM and its biotransformation products was slow, with 21.3% of the administered radioactivity found in the feces and 2.8% in the urine during the 14-d collection period. Biliary excretion seems to be the major route of elimination of TEHTM. The pharmacokinetic data gathered in the present investigation are compared to di-(2-ethylhexyl)phthalate (DEHP), a widely used plasticizer for PVC

  8. Thermal decomposition of uranyl nitrate hexahydrate. Study of intermediate reaction products; Decomposition thermique du nitrate d'uranyle hexahydrate etude des intermediaires de cette decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Chottard, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1970-07-01

    The thermal decomposition of uranyl nitrate hexahydrate has been carried but at constant pressure and constant rate of reaction. The following intermediary products have been shown to exist and isolated: UO{sub 2}(NO{sub 3}){sub 2}.3H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2}. 2H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2}. H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2} and UO{sub 3}. These products, together with the hexahydrate UO{sub 2} (NO{sub 3}){sub 2}.6H{sub 2}O, have been studied by: - X-ray diffraction, using the Debye-Scherrer method.- infra-red spectrography: determination of the type of bonding for the water and the nitrate groups. - nuclear magnetic resonance: study of the mobility of water molecules. The main results concern: - the water molecule bonds in the series of hydrates with 6.3 and 2 H{sub 2}O. - isolation and characterization of uranyl nitrate monohydrate, together with the determination of its molecular structure. - the mobility of the water molecules in the series of the hydrates with 6.3 and 2 H{sub 2}O. An analysis is made of the complementary results given by infra-red spectroscopy and nuclear magnetic resonance; they are interpreted for the whole of the hydrate series. [French] La decomposition thermique du nitrate d'uranyle hexahydrate a ete effectuee en operant a pression et vitesse de decomposition constantes. Les produits intermediaires suivants ont ete mis en evidence et isoles: UO{sub 2}(NO{sub 3}){sub 2}, 3H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2}, 2H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2},H{sub 2}O; UO{sub 2}(NO{sub 3}){sub 2} et UO{sub 3}. Ces composes, ainsi que l'hexahydrate UO{sub 2}(NO{sub 3} ){sub 2}, 6H{sub 2}O ont ete etudies par: - diffraction des rayons X, selon la methode Debye-Scherrer.- spectrographie infra-rouge: determination des modes de liaison de l'eau et des groupements nitrate. - resonance magnetique nucleaire: etude de la mobilite des molecules d'eau. Les principaux resultats portent sur: - les liaisons des molecules d'eau dans la

  9. Blood burden of di(2-ethylhexyl) phthalate and its primary metabolite mono(2-ethylhexyl) phthalate in pregnant and nonpregnant rats and marmosets

    International Nuclear Information System (INIS)

    Kessler, Winfried; Numtip, Wanwiwa; Grote, Konstanze; Csanady, Gyoergy A.; Chahoud, Ibrahim; Filser, Johannes G.

    2004-01-01

    A comparison of the dose-dependent blood burden of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate (MEHP) in pregnant and nonpregnant rats and marmosets is presented. Sprague-Dawley rats and marmosets were treated orally with 30 or 500 mg DEHP/kg per day, nonpregnant animals on 7 (rats) and 29 (marmosets) consecutive days, pregnant animals on gestation days 14-19 (rats) and 96-124 (marmosets). In addition, rats received a single dose of 1000 mg DEHP/kg. Blood was collected up to 48 h after dosing. Concentrations of DEHP and MEHP in blood were determined by GC/MS. In rats, normalized areas under the concentration-time curves (AUCs) of DEHP were two orders of magnitude smaller than the normalized AUCs of the first metabolite MEHP. Metabolism of MEHP was saturable. Repeated DEHP treatment and pregnancy had only little influence on the normalized AUC of MEHP. In marmosets, most of MEHP concentration-time courses oscillated. Normalized AUCs of DEHP were at least one order of magnitude smaller than those of MEHP. In pregnant marmosets, normalized AUCs of MEHP were similar to those in nonpregnant animals with the exception that at 500 mg DEHP/kg per day, the normalized AUCs determined on gestation days 103, 117, and 124 were distinctly smaller. The maximum concentrations of MEHP in blood of marmosets were up to 7.5 times and the normalized AUCs up to 16 times lower than in rats receiving the same daily oral DEHP dose per kilogram of body weight. From this toxicokinetic comparison, DEHP can be expected to be several times less effective in the offspring of marmosets than in that of rats if the blood burden by MEHP in dams can be regarded as a dose surrogate for the MEHP burden in their fetuses

  10. Metabolism of di(2-ethylhexyl) phthalate (DEHP) and mono-(2-ethylhexyl) phthalate (MEHP) in rats: in vivo and in vitro dose and time dependency of metabolism

    International Nuclear Information System (INIS)

    Lhuguenot, J.C.; Mitchell, A.M.; Milner, G.; Lock, E.A.; Elcombe, C.R.

    1985-01-01

    This study investigated the in vivo metabolism of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate (MEHP) in rats after multiple dosing, the metabolism of MEHP in primary rat hepatocyte cultures for periods of up to 3 days, and the biotransformation of some major metabolites of MEHP. Rats were orally administered [ 14 C]DEHP or [ 14 C]MEHP at doses of 50 and 500 mg/kg body wt for three consecutive days. Urine was collected at 24-hr intervals, and metabolite profiles were determined. After a single dose of either compound, urinary metabolite profiles were similar to those previously reported. However, after multiple administration of both DEHP and MEHP at 500 mg/kg, increases in omega-/beta-oxidation products [metabolites I and V, mono(3-carboxy-2-ethylpropyl) phthalate and mono(5-carboxy-2-ethylpentyl) phthalate, respectively] and decreases in omega - 1-oxidation products [metabolites VI and IX, mono(2-ethyl-5-oxohexyl) phthalate and mono(2-ethyl-5-hydroxyhexyl) phthalate, respectively] were seen. At the low dose of 50 mg/kg little or no alteration in urinary metabolite profiles was observed. At 500 mg/kg of MEHP a 4-fold stimulation of CN- -insensitive palmitoyl-CoA oxidation (a peroxisomal beta-oxidation marker) was seen after three consecutive daily doses. At the low dose of 50 mg/kg only a 1.8-fold increase was noted. Similar observations were made with rat hepatocyte cultures. MEHP at concentrations of 50 and 500 microM was extensively metabolized in the rat hepatocyte cultures. Similar metabolic profiles to those seen after in vivo administration of MEHP were observed. At the high (500 microM) concentration of MEHP, changes in the relative proportions of omega- and omega- 1-oxidized metabolites were seen

  11. Tris(2-ethylhexyl)phosphine oxide as an effective solvent mediator for constructing a serotonin-selective membrane electrode

    International Nuclear Information System (INIS)

    Ueda, Keisuke; Yonemoto, Rei; Komagoe, Keiko; Masuda, Kazufumi; Hanioka, Nobumitsu; Narimatsu, Shizuo; Katsu, Takashi

    2006-01-01

    A series of solvent mediators containing a phosphoryl (P=O) group, such as tris(2-ethylhexyl)phosphate, bis(2-ethylhexyl) 2-ethylhexylphosphonate, 2-ethylhexyl bis(2-ethylhexyl)phosphinate, and tris(2-ethylhexyl)phosphine oxide, were used to construct serotonin-selective membrane electrodes. We found that replacing the alkoxy groups attached to phosphorus atoms in P=O groups with alkyl groups strengthened the response of the electrode to serotonin, suppressing remarkably interference from inorganic cations, such as Na + . Thus, an electrode combining tris(2-ethylhexyl)phosphine oxide with an ion-exchanger, sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propyl)phenyl]borate, gave a detection limit of 9 x 10 -6 M with a slope of 55.2 mV per concentration decade in physiological saline containing 150 mM NaCl and 10 mM NaH 2 PO 4 /Na 2 HPO 4 (pH 7.4). This is the best detection limit of any serotonin-selective electrode developed to date. The selectivity of this electrode for serotonin was over 10 3 times that for inorganic cations, such as Na + and K + , and lipophilic quaternary ammonium ions, such as acetylcholine and (C 2 H 5 ) 4 N + . Using the electrode, we measured the amount of serotonin released from platelets and found that the results agreed well with those obtained by a conventional fluorimetric assay of serotonin

  12. Electrodeposition of polypyrrole on aluminium in the presence of sodium bis(2-ethylhexyl) sulfosuccinate

    International Nuclear Information System (INIS)

    Lehr, I.L.; Saidman, S.B.

    2006-01-01

    Stable and adherent polypyrrole films have been successfully electrodeposited onto aluminium electrode over a wide solution pH interval by using sodium bis(2-ethylhexyl) sulfosuccinate as dopant. The redox behaviour of the deposited coating was studied by cyclic voltammetry in different electrolytes and the corrosion protection properties were examined in chloride solution by polarisation studies and open circuit measurements. The polymer film was characterised by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX). The obtained results are explained considering the surfactant remains entrapped into the polymer matrix. The coatings inhibit the oxidation of the aluminium substrate even on polarisation to high anodic potentials

  13. Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

    International Nuclear Information System (INIS)

    Lehr, I.L.; Saidman, S.B.

    2012-01-01

    This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

  14. Influence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) on zinc electrodeposition

    Science.gov (United States)

    Lehr, I. L.; Saidman, S. B.

    2012-03-01

    This work is a study of the electrodeposition of zinc onto SAE 4140 steel electrodes using solutions containing zinc sulfate and bis(2-ethylhexyl) sodium sulfosuccinate (AOT). The influence of different parameters such as electrolyte concentration, electrodeposition time and temperature on the morphology of the electrodeposits was analyzed. The deposits were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction. The variation of open circuit potential over time in chloride solutions was also evaluated. The nucleation-growth process and consequently the morphology of the electrodeposits are modified in the presence of AOT. The surfactant induces the formation of a porous deposit.

  15. Antitumour evaluation of di-(2-ethylhexyl) phthalate (DEHP) isolated from Calotropis gigantea L. flower.

    Science.gov (United States)

    Habib, Muhammad Rowshanul; Karim, Muhammad Rezaul

    2012-12-01

    The objective of the study is to explore the anticancer activity of di-(2-ethylhexyl) phthalate (DEHP) isolated from Calotropis gigantea flower against Ehrlich ascites carcinoma cells (EAC) in Swiss albino mice. The activity of DEHP was evaluated at doses of 10, 20 and 40 mg kg-1 body mass applied intraperitoneally. DEHP showed a significant decrease in viable cell count (p SALP and SGOT) to normal level. Results of this study indicate that DEHP show potent dose dependent antitumour activity against EAC in vivo.

  16. Transplacental transfer of monomethyl phthalate and mono(2-ethylhexyl) phthalate in a human placenta perfusion system

    DEFF Research Database (Denmark)

    Mose, Tina; Knudsen, Lisbeth E; Hedegaard, Morten

    2007-01-01

    The transplacental passage of monomethylphtalate (mMP) and mono (2-ethylhexyl) phthalate (mEHP) was studied using an ex vivo placental perfusion model with simultaneous perfusion of fetal and maternal circulation in a single cotyledon. Umbilical cord blood and placental tissue collected both before...... plasma samples. mMP and possibly other short-chained phthalate monoesters in maternal blood can cross the placenta by slow transfer, whereas the results indicate no placental transfer of mEHP. Further studies are recommended....

  17. Adjuvant effects of inhaled mono-2-ethylhexyl phthalate in BALB/cJ mice

    DEFF Research Database (Denmark)

    Hansen, Jitka Stilund; Larsen, Søren Thor; Poulsen, Lars K.

    2007-01-01

    Phthalates, including di(2-ethylhexyl) phthalate (DEHP), are widely used and have been linked with the development of wheezing and asthma. The main metabolite of DEHP, mono-2-ethylhexyl phthalate (MEHP), was investigated for adjuvant effects in a mouse inhalation model. BALB/cJ mice were exposed...... to aerosols of 0.03 or 0.4 mg/m(3) MEHP 5 days/week for 2 weeks and thereafter weekly for 12 weeks together with a low dose of ovalbumin (OVA) as a model allergen. Mice exposed to OVA alone or OVA+Al(OH)(3) served as negative and positive controls, respectively. Finally, all groups were exposed to a nebulized...... as of eosinophils in BAL fluid were observed. OVA-specific IgG1 production in both MEHP groups was significantly increased. OVA-specific IgE and IgG2a were not increased significantly. A dose-dependent increase in inflammatory cells was observed in BAL fluid, leading to significantly higher lymphocyte...

  18. Pollution par les nitrates des eaux souterraines du bassin d'Essaouira (Maroc)

    Science.gov (United States)

    Laftouhi, Nour-Eddine; Vanclooster, Marnik; Jalal, Mohammed; Witam, Omar; Aboufirassi, Mohamed; Bahir, Mohamed; Persoons, Étienne

    2003-03-01

    The Essaouira Basin (Morocco) contains a multi-layered aquifer situated in fractured and karstic materials from the Middle and Upper Cretaceous (the Cenomanian, Turonian and Senonian). Water percolates through the limestone and dolomite formations of the Turonian stage either through the marls and calcareous marls of the Cenomanian or through the calcareous marly materials of the Senonian. The aquifer system may be interconnected since the marl layer separating the Turonian, Cenomanian and Senonian aquifers is thin or intensively fractured. In that case, the water is transported through a network of fractures and stratification joints. This paper describes the extent of the nitrate pollution in the area and its origin. Most of the wells and drillholes located in the Kourimat perimeter are contaminated by nitrates with some concentrations over 400 mg l-1. Nitrate contamination is also observed in the surface water of the Qsob River, which constitutes the natural outlet of the multi-layered complex aquifer system. In this area, agriculture is more developed than in the rest of the Essaouira Basin. Diffuse pollution of the karstic groundwater body by agricultural fertiliser residues may therefore partially explain the observed nitrate pollution. However, point pollution around the wells, springs and drillholes from human wastewater, livestock faeces and the mineralisation of organic debris close to the Muslim cemeteries cannot be excluded.

  19. Effects of maternal exposure to di(2-ethylhexyl)phthalate (DEHP) during pregnancy on susceptibility to neonatal asthma

    Energy Technology Data Exchange (ETDEWEB)

    Shin, In-Sik; Lee, Mee-Young [Basic Herbal Medicine Research Group, Korea Institute of Oriental Medicine, 483 Expo-ro, Yusung-gu, Daejeon 305-811 (Korea, Republic of); Cho, Eun-Sang [College of Veterinary Medicine, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Choi, Eun-young [College of Nursing and Health, Kongju National University, 56 Gongju Daehak-ro, Gongju, Chungnam 314-701 (Korea, Republic of); Son, Hwa-Young [College of Veterinary Medicine, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Lee, Kyoung-Youl, E-mail: youl10@hanmail.net [College of Nursing and Health, Kongju National University, 56 Gongju Daehak-ro, Gongju, Chungnam 314-701 (Korea, Republic of)

    2014-02-01

    Di(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and is widely dispersed in the environment. In this study, we investigated the effects of maternal exposure to DEHP during pregnancy on neonatal asthma susceptibility using a murine model of asthma induced by ovalbumin (OVA). Pregnant BALB/c mice received DEHP from gestation day 13 to lactation day 21. Their offspring were sensitized on postnatal days (PNDs) 9 and 15 by intraperitoneal injection of 0.5 μg OVA with 200 μg aluminum hydroxide. On PNDs 22, 23 and 24, live pups received an airway challenge of OVA for 30 min. Offspring from pregnant mice that received DEHP showed reductions in inflammatory cell count, interleukin (IL)-4, IL-13, and eotaxin in their bronchoalveolar lavage fluid and in total immunoglobulin E and OVA-specific IgE in their plasma compared with offspring from pregnant mice that did not receive DEHP treatment. These results were consistent with histological analysis and immunoblotting. Maternal exposure to DEHP reduces airway inflammation and mucus production in offspring, with a decrease in inducible nitric oxide synthase (iNOS) in the lung tissue. This study suggests that maternal exposure to DEHP during pregnancy reduces asthmatic responses induced by OVA challenge in offspring. These effects were considered to be closely related to the suppression of Th2 immune responses and iNOS expression. - Highlights: • Maternal exposure to di(2-ethylhexyl)phthalate reduces asthmatic response in pups. • Di(2-ethylhexyl)phthalate reduces eosinophilia induced by ovalbumin exposure. • Di(2-ethylhexyl)phthalate reduces T-helper type 2 cytokine production. • Di(2-ethylhexyl)phthalate attenuates airway inflammation and mucus production. • Di(2-ethylhexyl)phthalate suppresses inducible nitric oxide synthase in lung tissue.

  20. Effects of maternal exposure to di(2-ethylhexyl)phthalate (DEHP) during pregnancy on susceptibility to neonatal asthma

    International Nuclear Information System (INIS)

    Shin, In-Sik; Lee, Mee-Young; Cho, Eun-Sang; Choi, Eun-young; Son, Hwa-Young; Lee, Kyoung-Youl

    2014-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and is widely dispersed in the environment. In this study, we investigated the effects of maternal exposure to DEHP during pregnancy on neonatal asthma susceptibility using a murine model of asthma induced by ovalbumin (OVA). Pregnant BALB/c mice received DEHP from gestation day 13 to lactation day 21. Their offspring were sensitized on postnatal days (PNDs) 9 and 15 by intraperitoneal injection of 0.5 μg OVA with 200 μg aluminum hydroxide. On PNDs 22, 23 and 24, live pups received an airway challenge of OVA for 30 min. Offspring from pregnant mice that received DEHP showed reductions in inflammatory cell count, interleukin (IL)-4, IL-13, and eotaxin in their bronchoalveolar lavage fluid and in total immunoglobulin E and OVA-specific IgE in their plasma compared with offspring from pregnant mice that did not receive DEHP treatment. These results were consistent with histological analysis and immunoblotting. Maternal exposure to DEHP reduces airway inflammation and mucus production in offspring, with a decrease in inducible nitric oxide synthase (iNOS) in the lung tissue. This study suggests that maternal exposure to DEHP during pregnancy reduces asthmatic responses induced by OVA challenge in offspring. These effects were considered to be closely related to the suppression of Th2 immune responses and iNOS expression. - Highlights: • Maternal exposure to di(2-ethylhexyl)phthalate reduces asthmatic response in pups. • Di(2-ethylhexyl)phthalate reduces eosinophilia induced by ovalbumin exposure. • Di(2-ethylhexyl)phthalate reduces T-helper type 2 cytokine production. • Di(2-ethylhexyl)phthalate attenuates airway inflammation and mucus production. • Di(2-ethylhexyl)phthalate suppresses inducible nitric oxide synthase in lung tissue

  1. The Adverse Cardiac Effects of Di(2-ethylhexyl) phthalate and Bisphenol A

    Science.gov (United States)

    Posnack, Nikki Gillum

    2014-01-01

    The ubiquitous nature of plastics has raised concerns pertaining to continuous exposure to plastic polymers and human health risks. Of particular concern is the use of endocrine-disrupting chemicals (EDCs) in plastic production, including Di(2-ethylhexyl) phthalate (DEHP) and Bisphenol A (BPA). Widespread and continuous exposure to DEHP and BPA occurs through dietary intake, inhalation, dermal and intravenous exposure via consumer products and medical devices. This article reviews the literature examining the relationship between DEHP and BPA exposure and cardiac toxicity. In vitro and in vivo experimental reports are outlined, as well as epidemiological studies which examine the association between these chemicals and cardiovascular outcomes. Gaps in our current knowledge are also discussed, along with future investigative endeavors that may help resolve whether DEHP and/or BPA exposure has a negative impact on cardiovascular physiology. PMID:24811950

  2. Urinary concentrations of di(2-ethylhexyl) phthalate metabolites and serum reproductive hormones

    DEFF Research Database (Denmark)

    Mendiola, Jaime; Meeker, John D; Jørgensen, Niels

    2012-01-01

    Urinary concentrations of metabolites of the anti-androgenic xenobiotic di-(2-ethylhexyl) phthalate (DEHP) were previously shown to be weakly associated with serum levels of several hormones in 2 disparate US populations: partners of pregnant women participating in the Study for Future Families...... and partners in infertile couples from Massachusetts General Hospital infertility clinic. The observed associations between phthalate metabolites and reproductive hormones were robust and insensitive to the characteristics of the subpopulation or the laboratory in which the hormones were measured, despite...... the fact that these 2 populations span a range of fertility, urinary phthalate metabolites, and reproductive hormone levels. We therefore examined associations between urinary metabolites of DEHP and reproductive hormones-follicle-stimulating hormone, luteinizing hormone, testosterone (T), inhibin B...

  3. Effect of nanoparticle encapsulation on the photostability of the sunscreen agent, 2-ethylhexyl-p-methoxycinnamate.

    Science.gov (United States)

    Perugini, P; Simeoni, S; Scalia, S; Genta, I; Modena, T; Conti, B; Pavanetto, F

    2002-10-10

    The aim of this study was to investigate the influence of nanoparticle-based systems on the light-induced decomposition of the sunscreen agent, trans-2-ethylhexyl-p-methoxycinnamate (trans-EHMC). Ethylcellulose (EC) and poly-D,L-lactide-co-glycolide (PLGA) were used as biocompatible polymers for the preparation of the particulate systems. The "salting out" method was used for nanoparticle preparation and several variables were evaluated in order to optimize product characteristics. The photodegradation of the sunscreen agent in emulsion vehicles was reduced by encapsulation into the PLGA nanoparticles (the extent of degradation was 35.3% for the sunscreen-loaded nanoparticles compared to 52.3% for free trans-EHMC) whereas the EC nanoparticle system had no significant effect. Therefore, PLGA nanoparticles loaded with trans-EHMC improve the photostability of the sunscreen agent.

  4. Analysis of 2-ethylhexyl-p-methoxycinnamate in sunscreen products by HPLC and Raman spectroscopy.

    Science.gov (United States)

    Cheng, J; Li, Y S; L Roberts, R; Walker, G

    1997-10-01

    The analyses of 2-ethylhexyl-p-methoxycinnamate (EHMC) using HPLC and Raman spectroscopy have been undertaken and compared. EHMC, which is one of the most widely used sunscreen agents in suncare products in the US, exhibits a strong Raman signal. This signal clearly appears in both ethanol solutions of EHMC as well as in commercial sunscreen lotions containing this sun screen agent. A method for the direct detection and analysis of EHMC has been developed using Raman spectroscopy. This was accomplished by correlating the Raman intensities with the HPLC assays for a series of prototype suncare formulations. Based upon this information, it would be possible to employ Raman spectroscopy as an in-process control method in the commercial production of suncare products containing EHMC. The possibility of applying surface-enhanced Raman scattering for trace analysis was discussed.

  5. Transport of uranium by supported liquid membrane containing bis(2-ethylhexyl) hydrogenphosphate and 1-octanol

    International Nuclear Information System (INIS)

    Akiba, Kenichi; Kanno, Takuji; Takahashi, Toshihiko.

    1984-01-01

    Carrier-mediated transport of uranium(VI) has been studied by means of liquid membranes impregnated in a microporous polymer. Liquid membranes containing bis(2-ethylhexyl) hydrogenphosphate (DEHPA) alone yielded inadequate stripping of uranium. The addition of 1-octanol to DEHPA solutions resulted in a decrease in extractability, and made it possible to control the distribution ratio of uranium. Uranium in the feed solution was sufficiently transported across the liquid membrane containing this DEHPA-1-octanol mixture into the product solution. The apparent rate constant (ksub(obs)) of transport increased slightly with an increase in carrier concentrations. Variations in acid concentrations of the feed solution (pH 2.5--3.2) and the product solution (0.1--1.0 M H 2 SO 4 ) had little effect on the transport rate. A large excess of uranium, more than the carrier content in the liquid membrane, was finally concentrated in the stripping acid. (author)

  6. Toxicity of di-(2-ethylhexyl) phthalate on the anaerobic digestion of wastewater sludge

    DEFF Research Database (Denmark)

    Alatriste-Mondragon, Felipe; Iranpour, R.; Ahring, Birgitte Kiær

    2003-01-01

    Previous studies on the microbial degradation of individual phthalic acid esters (PAEs) have demonstrated that the compounds with short ester hydrocarbon chains are easily biodegraded and mineralized, but PAEs with long ester chains are less susceptible to degradation and some of them...... Bureau of Sanitation's Hyperion Treatment Plant. Di (2-ethylhexyl) phthalate (DEHP), the most common persistent PAE found in wastewater, and di-n-butyl phthalate (DBP), a common PAE with short ester chains, were sorbed into the sludge fed to a bench-scale digester for a period of 12 weeks. DEHP...... degradation was always poor, and accumulation of DEHP was correlated with inhibition of the microbial degradation of DBP and with process instability of the test digester. Inhibition of the DBP removal was completely reversed after DEHP addition was discontinued, but biogas production never recovered...

  7. Mono-2-ethylhexyl phthalate induces oxidative stress responses in human placental cells in vitro

    International Nuclear Information System (INIS)

    Tetz, Lauren M.; Cheng, Adrienne A.; Korte, Cassandra S.; Giese, Roger W.; Wang, Poguang; Harris, Craig; Meeker, John D.; Loch-Caruso, Rita

    2013-01-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. - Highlights: ► MEHP increased reactive oxygen species, oxidative DNA damage, and caspase activity. ► MEHP induced expression of PTGS2, a gene

  8. Experimental density and viscosity measurements of di(2ethylhexyl)sebacate at high pressure

    International Nuclear Information System (INIS)

    Paredes, Xavier; Fandino, Olivia; Pensado, Alfonso S.; Comunas, Maria J.P.; Fernandez, Josefa

    2012-01-01

    Highlights: → We measure viscosities for di(2-ethylhexyl)sebacate from (298.15 to 398.15) K and up to 60 MPa. → We measure densities for DEHS from (298.15 to 373.15) K and from (0.1 to 60) MPa. → The reported and lit. data were used in a viscosity correlation from (273 to 491) K and up to 1.1 GPa. → This correlation could be used in industrial equipment that operate at high pressures. - Abstract: Experimental densities and dynamic viscosities of di(2-ethylhexyl)sebacate (DEHS) are the object of study in this work. DEHS could be a useful industrial reference fluid for moderately high viscosity at high pressures as it is often used as a pressure transmitting fluid. At atmospheric pressure the density and viscosity measurements have been performed in a rotational SVM 3000 Stabinger viscometer from (273.15 to 373.15) K, whereas from (0.1 to 60) MPa and from (298.15 to 398.15) K an automated Anton Paar DMA HPM vibrating-tube densimeter, and a high-pressure rolling-ball viscometer were used. Several Vogel-Fulcher-Tammann type equations were used to fit the experimental values of viscosity to the pressure and temperature. The measured viscosity data have been used together with previous data found in the literature to establish a correlation of the viscosity surface η(T, p) of DEHS, covering a temperature range from (273 to 491) K and pressure up to 1.1 GPa. This correlation could be used in industrial equipment like viscometers and other devices that operate at high pressures. Our viscosity data have also been fitted as a function of temperature and volume to the thermodynamic scaling model of Roland et al. [C.M. Roland, S. Bair, R. Casalini, J. Chem. Phys. 125 (2006) 124508].

  9. Effect of mono-(2-ethylhexyl) phthalate on steroid production of human granulosa cells

    International Nuclear Information System (INIS)

    Reinsberg, Jochen; Wegener-Toper, Petra; Ven, Katrin van der; Ven, Hans van der; Klingmueller, Dietrich

    2009-01-01

    The phthalate ester mono-(2-ethylhexyl) phthalate (MEHP) is the active metabolite of di-(2-ethylhexyl) phthalate, a high-production-volume chemical used as a plasticizer and solvent in numerous consumer products. MEHP has been demonstrated to be a reproductive toxicant in rodents decreasing estradiol and progesterone production in preovulatory granulosa cells. In the present study, we examined the effect of MEHP on steroid production of human granulosa-lutein (GL) cells. Human GL cells collected from women undergoing in vitro fertilization were cultured in medium containing FSH, hCG and 8-Br-cAMP, respectively, together with various concentrations of MEHP (0-500 μmol L -1 ). After incubation for 48 h estradiol and progesterone were assayed in the spent culture medium. Furthermore, aromatase activity and mRNA levels of GL cells were determined. Basal as well as FSH-, hCG- and 8-Br-cAMP-stimulated estradiol production of GL cells was suppressed by MEHP in a dose-dependent manner (IC 50 = 105 μmol L -1 , 138 μmol L -1 , 49 μmol L -1 and 78 μmol L -1 ). Furthermore aromatase activity and mRNA levels were reduced in GL cells cultured with MEHP. In contrast, MEHP did not alter the production of progesterone up to a concentration of 167 μmol L -1 . The present data indicate that MEHP is a specific inhibitor of estradiol production in human GL cells with a post-cAMP site of action. The inhibition of estradiol production obviously results from a reduction of aromatase activity on the transcript level. As the in vitro effective doses of MEHP are within the range of real environmental exposure levels an inhibitory effect on estrogen production in vivo seems to be possible.

  10. Mono-2-ethylhexyl phthalate induces oxidative stress responses in human placental cells in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Tetz, Lauren M., E-mail: ltetz@umich.edu [Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109-2029 (United States); Cheng, Adrienne A.; Korte, Cassandra S. [Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109-2029 (United States); Giese, Roger W.; Wang, Poguang [Department of Pharmaceutical Sciences, Northeastern University, 360 Huntingon Ave, Boston, MA 02115 (United States); Harris, Craig; Meeker, John D.; Loch-Caruso, Rita [Department of Environmental Health Sciences, University of Michigan, 1415 Washington Heights, Ann Arbor, MI 48109-2029 (United States)

    2013-04-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 μM MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 μM MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. - Highlights: ► MEHP increased reactive oxygen species, oxidative DNA damage, and caspase activity. ► MEHP induced expression of PTGS2, a gene

  11. Thyroid endocrine disruption in zebrafish larvae after exposure to mono-(2-ethylhexyl phthalate (MEHP.

    Directory of Open Access Journals (Sweden)

    Wenhui Zhai

    Full Text Available Phthalates are extensively used as plasticizers in a variety of daily-life products, resulting in widespread distribution in aquatic environments. However, limited information is available on the endocrine disrupting effects of phthalates in aquatic organisms. The aim of the present study was to examine whether exposure to mono-(2-ethylhexyl phthalate (MEHP, the hydrolytic metabolite of di-(2-ethylhexyl phthalate (DEHP disrupts thyroid endocrine system in fish. In this study, zebrafish (Danio rerio embryos were exposed to different concentrations of MEHP (1.6, 8, 40, and 200 μg/L from 2 h post-fertilization (hpf to 168 hpf. The whole-body content of thyroid hormone and transcription of genes involved in the hypothalamic-pituitary-thyroid (HPT axis were examined. Treatment with MEHP significantly decreased whole-body T4 contents and increased whole-body T3 contents, indicating thyroid endocrine disruption. The upregulation of genes related to thyroid hormone metabolism (Dio2 and UGT1ab might be responsible for decreased T4 contents. Elevated gene transcription of Dio1 was also observed in this study, which might assist to degrade increased T3 contents. Exposure to MEHP also significantly induced transcription of genes involved in thyroid development (Nkx2.1 and Pax8 and thyroid hormone synthesis (TSHβ, NIS and TG. However, the genes encoding proteins involved in TH transport (transthyretin, TTR was transcriptionally significantly down-regulated after exposure to MEHP. Overall, these results demonstrate that acute exposure to MEHP alters whole-body contents of thyroid hormones in zebrafish embryos/larvae and changes the transcription of genes involved in the HPT axis, thus exerting thyroid endocrine toxicity.

  12. Estimation of human percutaneous bioavailability for two novel brominated flame retardants, 2-ethylhexyl tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP), using the parallelogram approach

    Science.gov (United States)

    2-ethylhexyltetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) are novel brominated flame retardants (FRs). BEH-TEBP is used alone as a plasticizer or with EH-TBB in polyurethane foams; both are contaminants in the indoor and outdoor environments. In ...

  13. Toxicological investigation of di(2-ethylhexyl)phthalate in rats. The determination of a no-observed-effect-level

    NARCIS (Netherlands)

    Jansen EHJM; van den Ham WA; Dormans JAMA; van Apeldoorn ME; van Leeuwen FXR

    1992-01-01

    Two animal experiments are described in which male rats have been exposed to di(2-ethylhexyl)phthalate (DEHP) for 2 and 4 weeks. Besides morphometric analysis using both light and electron microscopy, a number of enzyme parameters in liver homogenates have been determined which have a relation with

  14. Relative sensitivity of developmental and immune parameters in juvenile versus adult male rats after exposure to di(2-ethylhexyl) phthalate

    NARCIS (Netherlands)

    Tonk, E.C.M.; Verhoef, A.; Gremmer, E.R.; van Loveren, H.; Piersma, A.H.

    2012-01-01

    The developing immune system displays a relatively high sensitivity as compared to both general toxicity parameters and to the adult immune system. In this study we have performed such comparisons using di(2-ethylhexyl) phthalate (DEHP) as a model compound. DEHP is the most abundant phthalate in the

  15. Achromobactor denitrificans SP1 produces pharmaceutically active 25C prodigiosin upon utilizing hazardous di(2-ethylhexyl)phthalate

    Science.gov (United States)

    Achromobacter denitrificans SP1 isolated from soil sludge heavily contaminated with plastic waste produced a novel pharmaceutically-active 25C prodigiosin analog during growth in a simple mineral salt medium supplemented with hazardous di(2-ethylhexyl)phthalate (DEHP) blended PVC plastics (in situ) ...

  16. Systematic review and meta-analysis of early life exposure to di(2-ethylhexyl) phthalate and obesity related outcomes in rodents

    NARCIS (Netherlands)

    Wassenaar, Pim Nicolaas Hubertus; Legler, Juliette

    Background It has been suggested that the plasticizer di(2-ethylhexyl) phthalate (DEHP) exerts obesogenic effects after pre- or perinatal exposure. Objective A systematic review with meta-analyses was conducted of early life exposure to DEHP, or its biologically active metabolite mono(2-ethylhexyl)

  17. Effects of sewage sludge on Di-(2-ethylhexyl) phthalate uptake by plants

    International Nuclear Information System (INIS)

    Aranda, J.M.; O'Connor, G.A.; Eiceman, G.A.

    1989-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a priority organic pollutant frequently found in municipal sludges. A greenhouse study was conducted to determine the effect of sludge on plant uptake of 14 C-DEHP (carbonyl labeled). Plants grown included three food chain crops, lettuce (Lactuca sativa L.), carrot (Daucus carota L.) and chile pepper (Capsicum annuum L.) and tall fescue (Festuca arundinacea Schreb.). Net 14 C concentration in plants grown in soil amended with 14 C-DEHP-contaminated sludge was independent of sludge rate (at the same DEHP loading) for lettuce, chile fruit, and carrot roots. Net 14 C concentration, however, was inversely related to sludge rate in carrot tops, fescue, and chile plants. Intact DEHP was not detected in plants by gas chromatography/mass spectrometry analysis. Calculated plant DEHP concentrations (based on measured net 14 C concentrations and DEHP specific activities) were generally correlated better with DEHP soil solution concentrations than with total DEHP soil concentrations. Net 14 C-DEHP bioconcentration factors were calculated from initial soil DEHP concentration and plant fresh weights. Bioconcentration factors ranged from 0.01 to 0.03 for fescue, lettuce, carrots, and chile, suggesting little DEHP uptake. Additionally, because intact DEHP was not detected in any plants, DEHP uptake by plants was of minor importance and would not limit sludge additions to soils used to grow these crops

  18. Toxicity effects of di-(2-ethylhexyl phthalate to Eisenia fetida at enzyme, cellular and genetic levels.

    Directory of Open Access Journals (Sweden)

    Tingting Ma

    Full Text Available Di-(2-ethylhexyl phthalate (DEHP is a dominant phthalic acid ester (PAE that has aroused public concern due to its resistance to degradation and its toxicity as an endocrine-disrupting compound. Effects of different concentrations of DEHP on Eisenia fetida in spiked natural soil have been studied in the body of the earthworm by means of soil cultivation tests 7, 14, 21 and 28 days after exposure. The results indicated that, in general, superoxide dismutase (SOD activity, malondialdehyde (MDA content, metallothionein (MT content, the expression of heat shock protein 70 (HSP 70 and all the tested geno-toxicity parameters are promoted as time elapses and with increasing concentration of DEHP. However, peroxidase (POD activity, neutral red retention time (NRRT and mitochondrial membrane potential difference values were found to decrease even at a low concentration of DEHP of 1 mg kg-1 soil (p<0.05. Clear toxic effects of DEHP on E. fetida have been generally recognized by means of the disturbance of antioxidant enzyme activity/content and critical proteins, cell membrane and organelle disorder and DNA damage estimated by length of tail, tail DNA ratio, and tail moment parameters. A concentration of DEHP of 3 mg kg-1 may be recommended as a precaution against the potential risk of PAEs in soils and for indicating suitable threshold values for other soil animals and soil micro-organisms.

  19. Degradation kinetics of di-(2-ethylhexyl) phthalate (DEHP) and organic matter of sewage sludge during composting

    International Nuclear Information System (INIS)

    Cheng, H.-F.; Kumar, Mathava; Lin, J.-G.

    2008-01-01

    The potential degradation of di-(2-ethylhexyl) phthalate (DEHP) and organic matter of sewage sludge by composting was investigated using laboratory reactor at different operating conditions (E-1, E-2 and E-3). In all conditions, single stage thermophilic phase was observed within 2 days and almost, 60% of DEHP was degraded under this phase. At the end of composting, total DEHP degradation of more than 85% was observed in all conditions and total carbon reduction was 11.8% in E-1, 7.6% in E-2 and 10.8% in E-3. Similar trend was observed in the degradation of total nitrogen. The reduction of volatile solids (VS) in the composting reactors was 5.4% in E-1 (18 days), 5.5% in E-2 (12 days) and 4.3% in E-3 (18 days). The degradation kinetics of DEHP in thermophilic phase (including initial mesophilic phase) and the phase there after were determined by first order and fractional power kinetics, respectively. The significance of experimental parameters in DEHP degradation was assessed by Pearson correlation approach. Elevated temperature produced during composting was effective for the rapid degradation of DEHP from sewage sludge compared to mesophilic treatment

  20. Prepubertal Exposure to Genistein Alleviates Di-(2-ethylhexyl Phthalate Induced Testicular Oxidative Stress in Adult Rats

    Directory of Open Access Journals (Sweden)

    Lian-Dong Zhang

    2014-01-01

    Full Text Available Di-(2-ethylhexyl phthalate (DEHP is the most widely used plastizer in the world and can suppress testosterone production via activation of oxidative stress. Genistein (GEN is one of the isoflavones ingredients exhibiting weak estrogenic and potentially antioxidative effects. However, study on reproductive effects following prepubertal multiple endocrine disrupters exposure has been lacking. In this study, DEHP and GEN were administrated to prepubertal male Sprague-Dawley rats by gavage from postnatal day 22 (PND22 to PND35 with vehicle control, GEN at 50 mg/kg body weight (bw/day (G, DEHP at 50, 150, 450 mg/kg bw/day (D50, D150, D450 and their mixture (G + D50, G + D150, G + D450. On PND90, general morphometry (body weight, AGD, organ weight, and organ coefficient, testicular redox state, and testicular histology were studied. Our results indicated that DEHP could significantly decrease sex organs weight, organ coefficient, and testicular antioxidative ability, which largely depended on the dose of DEHP. However, coadministration of GEN could partially alleviate DEHP-induced reproductive injuries via enhancement of testicular antioxidative enzymes activities, which indicates that GEN has protective effects on DEHP-induced male reproductive system damage after prepubertal exposure and GEN may have promising future in its curative antioxidative role for reproductive disorders caused by other environmental endocrine disruptors.

  1. Use of di(2-ethylhexyl)phthalate-containing infusion systems increases the risk for cholestasis.

    Science.gov (United States)

    von Rettberg, Heike; Hannman, Torsten; Subotic, Ulrike; Brade, Joachim; Schaible, Thomas; Waag, Karl Ludwig; Loff, Steffan

    2009-08-01

    Most polyvinylchloride infusion systems are plasticized with up to 60% of di(2-ethylhexyl)phthalate (DEHP). DEHP is easily extracted from the tubing by total parenteral nutrition (TPN) solutions and has been shown to have toxic effects on various organ systems including the liver in animals and humans. A role was postulated for DEHP in the development of hepatobiliary dysfunction in premature and newborn infants receiving parenteral nutrition, and the incidence of cholestasis was investigated after changing from polyvinylchloride infusion systems to polyvinylchloride-free infusion systems. Two 3-year periods from 1998 to 2004 were investigated retrospectively before and after changing from polyvinylchloride to polyvinylchloride-free infusion systems in our department. This resulted in 1 group of 30 patients treated with polyvinylchloride lines and a second group of 46 patients treated with polyvinylchloride-free lines. The 2 groups were examined for the incidence of cholestasis and other possible contributing factors. Statistics were performed by using SAS software (SAS Institute, Cary, NC). After changing infusion systems, the incidence of cholestasis dropped from 50% to 13%. Using DEHP-plasticized polyvinylchloride infusion systems for TPN increased the risk for cholestasis by a factor of 5.6. The use of polyvinylchloride lines correlated strongly with the development of TPN-associated cholestasis (P = .0004). Using DEHP-containing polyvinylchloride infusions systems contributes to the development of cholestasis. Therefore, the use of DEHP-free infusion systems for TPN is recommended, especially in premature and newborn infants.

  2. Ultraviolet carcinogenesis in the hairless mouse skin. Influence of the sunscreen 2-ethylhexyl-p-methoxycinnamate.

    Science.gov (United States)

    Gallagher, C H; Greenoak, G E; Reeve, V E; Canfield, P J; Baker, R S; Bonin, A M

    1984-10-01

    The mutagenicity of some samples of a commonly used sunscreen, 2-ethylhexyl-p-methoxycinnamate (2-EHMC), led to these studies of its potential carcinogenicity in the HRA/Skh hairless mouse. In a daily treatment regime, repeated for 9 weeks, groups of mice were painted on the dorsum with 2-EHMC, and were then exposed to low doses of one of two artificial ultraviolet (UV) light sources. Mice were also treated with UV alone and with 2-EHMC alone. The accumulated UV exposure alone produced tumours in 40-100% of mice. However, 2-EHMC-treated mice were protected. Subsequent treatment of the 2-EHMC-protected mice, and mice previously treated with 2-EHMC alone, with the tumour promoter, croton oil, produced tumours on a significant number of animals. We conclude that 2-EHMC protects from UV tumorigenesis in the absence of a tumour promoter. However, although tumours appeared on only 4 out of 160 2-EHMC-treated mice exposed to UV, the carcinogenic process had been initiated in others, as application of the tumour promoter, croton oil, produced tumours. Statistical analysis of the incidence of promoted tumours inferred that prior irradiation with UV may not have been implicated. Therefore, 2-EHMC itself may initiate tumours in this strain of hairless mouse.

  3. Toxicity study of di(2-ethylhexyl)phthalate (DEHP) in combination with acetone in rats

    DEFF Research Database (Denmark)

    Dalgaard, M.; Østergaard, G.; Lam, Henrik Rye

    2000-01-01

    In two separate studies with exposure duration 9 weeks or 4 weeks, male Wistar rats were dosed with di(2-ethylhexyl)phthalate (DEHP) by gavage and exposed to drinking water with or without acetone (0.5% wt/v in the 9-week study, 1.0% wt/v in the 4-week study). In the 9-week study the doses of DEHP...... were 0, 125, 250, 500 or 1000 mg/kg b.wt. In the 4-week study the doses of DEHP were increased to 1000, 5000 and 10,000 mg/kg b.wt. In the 9-week study, the relative liver weight was increased in the rats exposed to 500 and 1000 mg/kg b.wt. No interaction of DEHP and acetone was observed in any...... of the measured parameters. In the 4-week study DEHP, at the highest dose level, resulted in severe general toxicity. The group exposed to DEHP in combination with acetone was more affected. Male fertility was decreased. Body weight was decreased, and the relative weight of the liver, kidney, heart, brain...

  4. Occurrence, fate and effects of Di (2-ethylhexyl) Phthalate in wastewater treatment plants: a review.

    Science.gov (United States)

    Zolfaghari, M; Drogui, P; Seyhi, B; Brar, S K; Buelna, G; Dubé, R

    2014-11-01

    Phthalates, such as Di (2-ethylhexyl) Phthalate (DEHP) are compounds extensively used as plasticizer for long time around the world. Due to the extensive usage, DEHP is found in many surface waters (0.013-18.5 μg/L), wastewaters (0.716-122 μg/L), landfill leachate (88-460 μg/L), sludge (12-1250 mg/kg), soil (2-10 mg/kg). DEHP is persistent in the environment and the toxicity of the byproducts resulting from the degradation of DEHP sometime exacerbates the parent compound toxicity. Water/Wastewater treatment processes might play a key role in delivering safe, reliable supplies of water to households, industry and in safeguarding the quality of water in rivers, lakes and aquifers. This review addresses state of knowledge concerning the worldwide production, occurrence, fate and effects of DEHP in the environment. Moreover, the fate and behavior of DEHP in various treatment processes, including biological, physicochemical and advanced processes are reviewed and comparison (qualitative and quantitative) has been done between the processes. The trends and perspectives for treatment of wastewaters contaminated by DEHP are also analyzed in this review. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. DI-(2-ETHYLHEXYL PHTHALATE OXIDATIVE DEGRADATION BY FENTON PROCESS IN SYNTHETIC AND REAL PETROCHEMICAL WASTEWATER

    Directory of Open Access Journals (Sweden)

    R. Esmaeli

    2011-09-01

    Full Text Available Di-(2-Ethylhexyl phthalate (DEHP belongs to the class of phthalate esters and is used as an additive in many products including plastics, paints and inks or as a solvent in industrial formulations. The degradation of DEHP in aqueous solution using oxidative Fenton reaction (H2O2/Fe2+ was carried out in this study. It was found that H2O2 concentration, Fe2+ concentration, and pH were the three main factors that could significantly influence the degradation rates of DEHP. The highest degradation percentage (85.6 % of DEHP was observed within 60 min at pH 3 in H2O2/Fe2+ system. The results of our study suggested that the concentration with 90 mg/L H2O2, 5 mg/L Fe2+, and 20 mg/L DEHP in the solution at pH 3 were the optimal conditions. The optimized reaction parameters were preceded for treatment of real wastewater obtained from a petrochemical plant.

  6. Mono-(2-Ethylhexyl Phthalate Promotes Pro-Labor Gene Expression in the Human Placenta.

    Directory of Open Access Journals (Sweden)

    Ximi K Wang

    Full Text Available Women exposed to phthalates during pregnancy are at increased risk for delivering preterm, but the mechanism behind this relationship is unknown. Placental corticotropin-releasing hormone (CRH and cyclooxygenase-2 (COX-2 are key mediators of parturition and are regulated by the non-canonical NF-kB (RelB/p52 signaling pathway. In this study, we demonstrate that one of the major phthalate metabolites, mono-(2-ethylhexyl-phthalate (MEHP, increased CRH and COX-2 mRNA and protein abundance in a dose-dependent manner in primary cultures of cytotrophoblast. This was coupled with an increase in nuclear import of RelB/p52 and its association with the CRH and COX-2 promoters. Silencing of NF-kB inducing kinase, a central signaling component of the non-canonical NF-kB pathway, blocked MEHP-induced upregulation of CRH and COX-2. These results suggest a potential mechanism mediated by RelB/p52 by which phthalates could prematurely induce pro-labor gene activity and lead to preterm birth.

  7. Growth of colonies and hyphal ultrastructure of filamentous fungi grown on dibutyl phthalate and di(2-ethylhexyl)phthalate

    OpenAIRE

    Suárez-Segundo, J.L.; Vázquez-López, D.; Torres-García, J.L.; Ahuactzin-Perez, M.; Montiel-Martínez, N.; Tlecuitl-Beristain, S.; Sánchez, C.

    2013-01-01

    Phthalates are compounds that give fl exnbíüty to the plastics and are considered mutagens and teratogens. Mycelial growth rate, biomass production and hyphal diameter of the young and mature zones of colonies of Fusarium oxysporum, Mortierella alpina, Pleurotuspulmonarius, two strains of Pleurotus ostreatus (Po 37 and Po 83) and one strain of Pleurotus florida grown on glucose, di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate were studied. F oxysporum had the highest mycelial growth r...

  8. Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite

    OpenAIRE

    Gackowska , Alicja; Przybyłek , Maciej; Studziński , Waldemar; Gaca , Jerzy

    2016-01-01

    International audience; In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography–mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in term...

  9. Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite

    OpenAIRE

    Gackowska, Alicja; Przybyłek, Maciej; Studziński, Waldemar; Gaca, Jerzy

    2018-01-01

    In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography-mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdo...

  10. Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite

    OpenAIRE

    Gackowska, Alicja; Przyby?ek, Maciej; Studzi?ski, Waldemar; Gaca, Jerzy

    2015-01-01

    In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography?mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdo...

  11. Dissolution of di-2-ethylhexyl phosphates of ree in an octane + octanol mixture under the influence of gaseous ammonia

    International Nuclear Information System (INIS)

    Trifonov, Y.I.; Legin, E.K.; Suglobov, D.N.

    1986-01-01

    The authors find that the solubility of di-2-ethylhexyl phosphates rises considerably under the influence of gaseous ammonia on the solvent-LnA 3 system when a mixture of octane and octanol is used as solvent. The dissolving power of ammonia rises with alcohol concentration and attains the maximum at an alcohol content of ca 20 vol. %. An equation is presented that describes the dependence of the LnA 3 solubility on the partial amonia pressure

  12. Biodegradation of di(2-ethylhexyl)phthalate in a typical tropical soil

    Energy Technology Data Exchange (ETDEWEB)

    Castelo de Moura Carrara, Silvia Marta; Morita, Dione Mari [Polytechnic School, University of Sao Paulo (Brazil); Boscov, Maria Eugenia Gimenez, E-mail: meboscov@usp.br [Polytechnic School, University of Sao Paulo (Brazil)

    2011-12-15

    Highlights: Black-Right-Pointing-Pointer Scarce literature on contamination of tropical soils by phthalates. Black-Right-Pointing-Pointer Investigation of mobility of DEHP in a tropical soil by infiltration tests showed that DEHP is retained in the upper layer of the soil. Black-Right-Pointing-Pointer Low air and water permeability indicate that in situ bioremediation is not feasible for this soil. Black-Right-Pointing-Pointer Respirometric tests were inadequate to investigate biodegradation because tropical soils are acidic. Black-Right-Pointing-Pointer Slurry-phase reactor with cement mixer provided significant biodegradation (99% in 49 days). - Abstract: The aim of this research was to evaluate the possibility of biodegradation of di(2-ethylhexyl)phthalate (DEHP), widely used as an industrial plasticizer and considered an endocrine-disrupting chemical included in the U.S. Environmental Protection Agency priority list, in a Brazilian tropical soil, which has not been previously reported in the literature, despite the geographic importance of tropical soils. Preliminary laboratory testing comprised respirometric, air and water permeability, and pilot scale infiltration tests. Standard respirometric tests were found inadequate for studying biodegradation in tropical contaminated soils, due to the effect of the addition of significant amounts of calcium carbonate, necessary to adjust soil pH. Pilot scale infiltration tests performed for 5 months indicated that DEHP was retained in the superficial layer of the soil, barely migrating downwards, whereas air and water permeability tests discarded in situ bioremediation. However, ex situ bioremediation was possible, using a slurry-phase reactor with acclimated microorganisms, in pilot scale tests conducted to remediate a total mass of 150 kg of contaminated soil with 100 mg DEHP/kg. The removal of DEHP in the slurry-phase reactor achieved the percentage of 99% in 49 days, with biodegradation following a first

  13. Effects of Di-(2-ethylhexyl Phthalate on the Hypothalamus–Uterus in Pubertal Female Rats

    Directory of Open Access Journals (Sweden)

    Te Liu

    2016-11-01

    Full Text Available The pollution of endocrine disruptors and its impact on human reproductive system have attracted much attention. Di-(2-ethylhexyl phthalate (DEHP, an environmental endocrine disruptor, is widely used in food packages, containers, medical supplies and children’s toys. It can cause diseases such as infertility, sexual precocity and uterine bleeding and thus arouse concerns from the society and scholars. The effect of DEHP on pubertal female reproductive system is still not well-studied. This study was to investigate the effects of DEHP on the hypothalamus–uterus in pubertal female rats, reveal the reproductive toxicity of DEHP on pubertal female rats and its mechanism, and provide scientific evidence for the evaluation of toxicity and toxic mechanism of DEHP on reproductive system. Forty-eight pubertal female rats were randomly divided into four groups and respectively administered via oral gavage 0, 250, 500, or 1000 mg/kg/d DEHP in 0.1 mL corn oil/20 g body weight for up to four weeks. Compared with control rats, the DEHP-treated rats showed: (1 higher gonadotropin-releasing hormone (GnRH level in the hypothalamus; (2 higher protein levels of GnRH in the hypothalamus; and (3 higher mRNA and protein levels of GnRH receptor (GnRHR in the uterus. Our data reveal that DEHP exposure may lead to a disruption in pubertal female rats and an imbalance of hypothalamus–uterus. Meanwhile, DEHP may, through the GnRH in the hypothalamus and its receptor on the uterus, lead to diseases of the uterus. DEHP may impose a negative influence on the development and functioning of the reproductive system in pubertal female rats.

  14. Effects of Di-(2-ethylhexyl) Phthalate on the Hypothalamus–Uterus in Pubertal Female Rats

    Science.gov (United States)

    Liu, Te; Jia, Yiyang; Zhou, Liting; Wang, Qi; Sun, Di; Xu, Jin; Wu, Juan; Chen, Huaiji; Xu, Feng; Ye, Lin

    2016-01-01

    The pollution of endocrine disruptors and its impact on human reproductive system have attracted much attention. Di-(2-ethylhexyl) phthalate (DEHP), an environmental endocrine disruptor, is widely used in food packages, containers, medical supplies and children’s toys. It can cause diseases such as infertility, sexual precocity and uterine bleeding and thus arouse concerns from the society and scholars. The effect of DEHP on pubertal female reproductive system is still not well-studied. This study was to investigate the effects of DEHP on the hypothalamus–uterus in pubertal female rats, reveal the reproductive toxicity of DEHP on pubertal female rats and its mechanism, and provide scientific evidence for the evaluation of toxicity and toxic mechanism of DEHP on reproductive system. Forty-eight pubertal female rats were randomly divided into four groups and respectively administered via oral gavage 0, 250, 500, or 1000 mg/kg/d DEHP in 0.1 mL corn oil/20 g body weight for up to four weeks. Compared with control rats, the DEHP-treated rats showed: (1) higher gonadotropin-releasing hormone (GnRH) level in the hypothalamus; (2) higher protein levels of GnRH in the hypothalamus; and (3) higher mRNA and protein levels of GnRH receptor (GnRHR) in the uterus. Our data reveal that DEHP exposure may lead to a disruption in pubertal female rats and an imbalance of hypothalamus–uterus. Meanwhile, DEHP may, through the GnRH in the hypothalamus and its receptor on the uterus, lead to diseases of the uterus. DEHP may impose a negative influence on the development and functioning of the reproductive system in pubertal female rats. PMID:27845755

  15. Di-(2-ethylhexyl) phthalate affects immune cells from atopic prone mice in vitro

    International Nuclear Information System (INIS)

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

    2009-01-01

    Phthalate esters as plasticizers have been widespread in the environment and may be associated with development of allergic diseases such as asthma and atopic dermatitis. However, the underlying mechanisms have not been fully elucidated. The present study investigated the effects of di-(2-ethylhexyl) phthalate (DEHP) on immune cells from atopic prone NC/Nga mice in vitro. Bone marrow-derived dendritic cells (BMDC) as a professional antigen-presenting cell and splenocytes as mixture of immune cells were used. BMDC were differentiated by culture with granulocyte macrophage-colony stimulating factor (GM-CSF) in the presence of DEHP (0.1-10 μM) for 6 days. In another experiments, BMDC were differentiated by culture with GM-CSF for 8 days then these BMDC were exposed to DEHP (0.1-100 μM) for 24 h. Splenocytes were exposed to DEHP for 24 h (0.1-100 μM) or 72 h (0.1-1000 nM). After the culture, the phenotypic markers and the function of BMDC and splenocytes were evaluated. BMDC differentiated in the presence of DEHP showed enhancement in the expression of MHC class II, CD86, CD11c and DEC205, and in their antigen-presenting activity. On the other hand, the function of the differentiated BMDC was not activated by DEHP although DEHP partly enhanced their expression of DEC205. DEHP-exposed splenocytes showed increases in their TCR and CD3 expression, interleukin-4 production, and antigen-stimulated proliferation. These results demonstrate that DEHP enhances BMDC differentiation but not activation and also enhances Th2 response in splenocytes from atopic prone mice. The enhancement might contribute to the aggravating effect of DEHP on allergic disorders.

  16. Mono-2-ethylhexyl phthalate associated with insulin resistance and lower testosterone levels in a young population.

    Science.gov (United States)

    Chen, Szu-Ying; Hwang, Jing-Shiang; Sung, Fung-Chang; Lin, Chien-Yu; Hsieh, Chia-Jung; Chen, Pau-Chung; Su, Ta-Chen

    2017-06-01

    Phthalates are commonly used as plasticizers and are reported to associate with testicular dysfunction or insulin resistance in different studies, but the concurrent relationship between phthalate exposure, testosterone levels, and insulin resistance in the young population is not well understood. We recruited 786 subjects aged 12-30 years from a population-based sample of Taiwanese adolescents and young adults from 2006 to 2008. Generalized additive models were used to evaluate glucose homeostasis and testicular function in relation to seven urinary phthalate metabolites among adolescents (aged 12-20) and young adults (aged 20-30) in Taiwan. We observed a trend toward a decrease in male testosterone and an increase in urinary mono-2-ethylhexyl phthalate (MEHP) levels across four quartiles of homeostasis model assessment of insulin resistance (HOMA-IR). After adjusting for potential covariates, generalized additive models further showed that log-transformed insulin and HOMA-IR were raised by 0.055 [95% confidence interval (CI), 0.027-0.082] and 0.056 (95% CI, 0.027-0.084), respectively, with a one-unit increase in log-transformed MEHP in young adults. In male adults (aged 22-30), the log-testosterone levels were reduced by 0.018 (95% CI, 0.001-0.036), with a one-unit of increase in log-transformed MEHP. Such relationships were not observed in adolescents. In conclusion, this study demonstrated age-related associations of urinary MEHP metabolites with impaired metabolic homeostasis of glucose that were only observed in young adults. In addition, MEHP exposure was concurrently associated with lower testosterone levels in young, male adults. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. [Effects of in utero exposure to di(2-ethylhexyl) phthalate on sexual development in female offspring].

    Science.gov (United States)

    Ding, Yu; Gao, Yu; Shi, Rong; Zhou, Yi-Jun; Tian, Ying

    2010-02-01

    To evaluate the ability of di(2-ethylhexyl) phthalate (DEHP) with inducing damage in sexual development of female offspring rats after maternal exposure. On gestational day (GD) 12, pregnant Wistar rats were weighed, encoded and randomly assigned to 5 groups (10 dams per group). From GD 12 through GD 17 each dam was dosed daily by gavage with either corn oil (vehicle control, 1 mgxkg(-1)xd(-1)) or DEHP (1, 250, 750 and 1000 mgxkg(-1)xd(-1)). Then female offspring were monitored for eye opening on postnatal day (PND) 14-17, organ coefficient on PND 22 and the time to vaginal opening on PND 30 - 38 (if vagina did not open during the period, observation time should extent to adult), as well as body weight, time to first estrus. No significant changes were observed on eye opening at any dose, which were (15.8 +/- 0.4) d, (16.3 +/- 0.6) d, (16.0 +/- 0.6) d, (15.9 +/- 0.6) d, (15.8 +/- 0.4) d respectively in control, 1, 250, 750 and 1000 mgxkg(-1)xd(-1) (F = 1.363, P = 0.262). However, 62.50% (15/24), 81.25% (26/32) female offspring were permanently absence of vaginal orifice in 750 and 1000 mgxkg(-1)xd(-1) groups respectively, while control, 1 and 250 mgxkg(-1)xd(-1) groups developed normally with vaginal orifices (chi(2) values were 84.92, 132.79, respectively, P xd(-1). After covariance adjustment for body weight, which can statistically influenced the age of vaginal opening (F = 40.857, P xd(-1) group was advanced than control (t = -2.056, P < 0.05). Exposure to DEHP in utero from GD 12 - 17 can result in abnormalities of sexual development such as the time to vaginal opening and vaginal atresia.

  18. Maternal exposure to di-(2-ethylhexyl) phthalate disrupts placental growth and development in pregnant mice

    Energy Technology Data Exchange (ETDEWEB)

    Zong, Teng; Lai, Lidan [Department of Physiology, School of Medicine, Nanchang University, Nanchang, Jiangxi 330006 (China); Hu, Jia [Department of Obstetrics and Gynecology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi (China); Guo, Meijun; Li, Mo; Zhang, Lu; Zhong, Chengxue; Yang, Bei; Wu, Lei; Zhang, Dalei; Tang, Min [Department of Physiology, School of Medicine, Nanchang University, Nanchang, Jiangxi 330006 (China); Kuang, Haibin, E-mail: kuanghaibin@ncu.edu.cn [Department of Physiology, School of Medicine, Nanchang University, Nanchang, Jiangxi 330006 (China)

    2015-10-30

    Highlights: • The influence of DEHP on the development of placenta was investigated. • DEHP disrupts the growth and development of placenta. • DEHP disrupts the formation of labyrinth vascularization. • DEHP inhibits the proliferation of ectoplacental cone and placenta. • DEHP induces the apoptosis of placenta via activated MAPK signaling pathway. - Abstract: Di-(2-ethylhexyl) phthalate (DEHP) is used as a plasticizer and widely dispersed in the environment. DEHP exposure reduces embryo implantations, increases embryonic loss, and decreases fetal body weights. However, no detailed information is available about the effect of DEHP on the placentation during pregnancy. Thus, our aim was to explore the effect of DEHP on the growth and development of placenta in vivo. Mice were administered DEHP by gavages at 125, 250, 500 mg/kg/day from gestational days (GD) 1 until sacrifice. Results showed that DEHP treatment significantly reduced the weight of placenta at GD 13. Histopathologically, in DEHP-treated group, the ectoplacental cones significantly became smaller at GD9, and total area of placenta and area of spongiotrophoblast were significantly reduced at GD 13. Expression levels of Ascl2, Esx1 and Fosl1 mRNA dramatically decreased in DEHP-treated placenta at GD 13. DEHP administration disrupted labyrinth vascularization of placentas, and inhibited proliferation and induced apoptosis of placenta by the activation of caspase-3 and -8, up-regulation of Bax and down-regulation of Bcl-2 mRNA and protein at GD 13. In conclusion, these results suggest that adverse pregnancy outcomes including low birth-weight and pregnancy loss exposed to DEHP are possibly mediated, at least in part, via the suppression of placental growth and development.

  19. Di (2-ethylhexyl Phthalate Exposure Impairs Growth of Antral Follicle in Mice.

    Directory of Open Access Journals (Sweden)

    Lan Li

    Full Text Available Di (2-ethylhexyl phthalate (DEHP is a widely used plastic additive. As an environmental endocrine disruptor, it has been shown to be harmful to the mammalian reproductive system. Previous studies indicated that DEHP inhibited the development of mouse ovarian follicles. However, the mechanisms by which DEHP affects ovarian antral follicle development during the pre-puberty stage are poorly understand. Thus, we investigated the effects of direct DEHP exposure on antral follicle growth in pre-pubescent mice by use of intraperitoneal injection. Our results demonstrated that the percentage of large antral follicles was significantly reduced when mice were exposed to 20 or 40 μg/kg DEHP every 5 days from postnatal day 0 (0 dpp to 15 dpp. In 20 dpp, we performed microarray of these ovaries. The microarray results indicated that mRNA levels of apoptosis related genes were increased. The mRNA levels of the apoptosis and cell proliferation (negative related genes Apoe, Agt, Glo1 and Grina were increased after DEHP exposure. DEHP induced the differential gene expression of Hsp90ab1, Rhoa, Grina and Xdh which may play an important role in this process. In addition, TUNEL staining and immunofluorescence showed that DEHP exposure significantly increased the number of TUNEL, Caspase3 and γH2AX positive ovarian somatic cells within the mouse ovaries. Flow cytometer analyses of redox-sensitive probes showed that DEHP caused the accumulation of reactive oxygen species. Moreover, the mRNA expression of ovarian somatic cell antioxidative enzymes was down-regulated both in vivo and in vitro. In conclusion, our data here demonstrated that DEHP exposure induced oxidative stress and ovarian somatic cell apoptosis, and thus may impact antral follicle enlargement during the pre-pubertal stage in mice.

  20. Optimization of 2-ethylhexyl palmitate production using lipozyme RM IM as catalyst in a solvent-free system.

    Science.gov (United States)

    Richetti, Aline; Leite, Selma G F; Antunes, Octávio A C; de Souza, Andrea L F; Lerin, Lindomar A; Dallago, Rogério M; Paroul, Natalia; Di Luccio, Marco; Oliveira, J Vladimir; Treichel, Helen; de Oliveira, Débora

    2010-04-01

    This work reports the application of a lipase in the 2-ethylhexyl palmitate esterification in a solvent-free system with an immobilized lipase (Lipozyme RM IM). A sequential strategy was used applying two experimental designs to optimize the 2-ethylhexyl palmitate production. An empirical model was then built so as to assess the effects of process variables on the reaction conversion. Afterwards, the operating conditions that optimized 2-ethylhexyl palmitate production were established as being acid/alcohol molar ratio 1:3, temperature of 70 degrees C, stirring rate of 150 rpm, 10 wt.% of enzyme, leading to a reaction conversion as high as 95%. From this point, a kinetic study was carried out evaluating the effect of acid:alcohol molar ratio, the enzyme concentration and the temperature on product conversion. The results obtained in this step permit to verify that an excess of alcohol (acid to alcohol molar ratio of 1:6), relatively low enzyme concentration (10 wt.%) and temperature of 70 degrees C, led to conversions next to 100%.

  1. Mechanisms of toxicity of di(2-ethylhexyl) phthalate on the reproductive health of male zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Uren-Webster, Tamsyn M.; Lewis, Ceri; Filby, Amy L.; Paull, Gregory C. [Hatherly Laboratories, School of Biosciences, University of Exeter, Prince of Wales Road, Exeter, Devon EX4 4PS (United Kingdom); Santos, Eduarda M., E-mail: e.santos@exeter.ac.uk [Hatherly Laboratories, School of Biosciences, University of Exeter, Prince of Wales Road, Exeter, Devon EX4 4PS (United Kingdom)

    2010-09-01

    Phthalates are ubiquitous in the aquatic environment and are known to adversely affect male reproductive health in mammals through interactions with multiple receptor systems. However, little is known about the risks they pose to fish. This project investigated the effects of di(2-ethylhexyl) phthalate (DEHP), the most commonly used phthalate, on the reproductive health of male zebrafish (Danio rerio). Males were treated with 0.5, 50 and 5000 mg DEHP kg{sup -1} (body weight) for a period of 10 days via intraperitoneal injection. The effects of the exposure were assessed by analysing fertilisation success, testis histology, sperm DNA integrity and transcript profiles of the liver and testis. A significant increase in the hepatosomatic index and levels of hepatic vitellogenin transcript were observed following exposure to 5000 mg DEHP kg{sup -1}. Exposure to 5000 mg DEHP kg{sup -1} also resulted in a reduction in fertilisation success of oocytes spawned by untreated females. However, survival and development of the resulting embryos were unaffected by all treatments, and no evidence of DEHP-induced sperm DNA damage was observed. Exposure to 50 and 5000 mg DEHP kg{sup -1} caused alterations in the proportion of germ cells at specific stages of spermatogenesis in the testis, including a reduction in the proportion of spermatozoa and an increase in the proportion of spermatocytes, suggesting that DEHP may inhibit the progression of meiosis. In parallel, exposure to 5000 mg DEHP kg{sup -1} increased the levels of two peroxisome proliferator-activated receptor (PPAR) responsive genes (acyl-coenzyme A oxidase 1 (acox1) and enoyl-coenzyme A, hydratase/3-hydroxyacyl coenzyme A dehydrogenase (ehhadh). These data demonstrated that exposure to high concentrations of DEHP disrupts spermatogenesis in adult zebrafish with a consequent decrease in their ability to fertilise oocytes spawned by untreated females. Furthermore, our data suggest that the adverse effects caused by

  2. Di (2-ethylhexyl) phthalate inhibits growth of mouse ovarian antral follicles through an oxidative stress pathway

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: weiwang2@illinois.edu; Craig, Zelieann R., E-mail: zelieann@illinois.edu; Basavarajappa, Mallikarjuna S., E-mail: mbasava2@illinois.edu; Gupta, Rupesh K., E-mail: drrupesh@yahoo.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2012-01-15

    Di (2-ethylhexyl) phthalate (DEHP) is a plasticizer that has been shown to inhibit growth of mouse antral follicles, however, little is known about the mechanisms by which DEHP does so. Oxidative stress has been linked to follicle growth inhibition as well as phthalate-induced toxicity in non-ovarian tissues. Thus, we hypothesized that DEHP causes oxidative stress and that this leads to inhibition of the growth of antral follicles. To test this hypothesis, antral follicles isolated from CD-1 mice (age 31–35 days) were cultured with vehicle control (dimethylsulfoxide [DMSO]) or DEHP (1–100 μg/ml) ± N-acetyl cysteine (NAC, an antioxidant at 0.25–1 mM). During culture, follicles were measured daily. At the end of culture, follicles were collected and processed for in vitro reactive oxygen species (ROS) assays to measure the presence of free radicals or for measurement of the expression and activity of various key antioxidant enzymes: Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX) and catalase (CAT). The results indicate that DEHP inhibits the growth of follicles compared to DMSO control and that NAC (0.25–1 mM) blocks the ability of DEHP to inhibit follicle growth. Furthermore, DEHP (10 μg/ml) significantly increases ROS levels and reduces the expression and activity of SOD1 compared to DMSO controls, whereas NAC (0.5 mM) rescues the effects of DEHP on ROS levels and SOD1. However, the expression and activity of GPX and CAT were not affected by DEHP treatment. Collectively, these data suggest that DEHP inhibits follicle growth by inducing production of ROS and by decreasing the expression and activity of SOD1. -- Highlights: ► DEHP inhibits growth and increases reactive oxygen species in ovarian antral follicles in vitro. ► NAC rescues the effects of DEHP on the growth and reactive oxygen species levels in follicles. ► DEHP decreases the expression and activity of Cu/Zn superoxide dismutase, which can be rescued by NAC, in antral

  3. Di-(2 ethylhexyl phthalate and flutamide alter gene expression in the testis of immature male rats

    Directory of Open Access Journals (Sweden)

    Yu Frank H

    2009-09-01

    Full Text Available Abstract We previously demonstrated that the androgenic and anti-androgenic effects of endocrine disruptors (EDs alter reproductive function and exert distinct effects on developing male reproductive organs. To further investigate these effects, we used an immature rat model to examine the effects of di-(2 ethylhexyl phthalate (DEHP and flutamide (Flu on the male reproductive system. Immature male SD rats were treated daily with DEHP and Flu on postnatal days (PNDs 21 to 35, in a dose-dependent manner. As results, the weights of the testes, prostate, and seminal vesicle and anogenital distances (AGD decreased significantly in response to high doses of DEHP or Flu. Testosterone (T levels significantly decreased in all DEHP- treated groups, whereas luteinizing hormone (LH plasma levels were not altered by any of the two treatments at PND 36. However, treatment with DEHP or Flu induced histopathological changes in the testes, wherein degeneration and disorders of Leydig cells, germ cells and dilatation of tubular lumen were observed in a dose-dependent manner. Conversely, hyperplasia and denseness of Leydig, Sertoli and germ cells were observed in rats given with high doses of Flu. The results by cDNA microarray analysis indicated that 1,272 genes were up-regulated by more than two-fold, and 1,969 genes were down-regulated in response to DEHP, Flu or both EDs. These genes were selected based on their markedly increased or decreased expression levels. These genes have been also classified on the basis of gene ontology (e.g., steroid hormone biosynthetic process, regulation of transcription, signal transduction, metabolic process, biosynthetic process.... Significant decreases in gene expression were observed in steroidogenic genes (i.e., Star, Cyp11a1 and Hsd3b. In addition, the expression of a common set of target genes, including CaBP1, Vav2, Plcd1, Lhx1 and Isoc1, was altered following exposure to EDs, suggesting that they may be marker genes to

  4. Estimation of human percutaneous bioavailability for two novel brominated flame retardants, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP)

    International Nuclear Information System (INIS)

    Knudsen, Gabriel A.; Hughes, Michael F.; Sanders, J. Michael; Hall, Samantha M.; Birnbaum, Linda S.

    2016-01-01

    2-Ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) are novel brominated flame retardants used in consumer products. A parallelogram approach was used to predict human dermal absorption and flux for EH-TBB and BEH-TEBP. [ 14 C]-EH-TBB or [ 14 C]-BEH-TEBP was applied to human or rat skin at 100 nmol/cm 2 using a flow-through system. Intact rats received analogous dermal doses. Treated skin was washed and tape-stripped to remove “unabsorbed” [ 14 C]-radioactivity after continuous exposure (24 h). “Absorbed” was quantified using dermally retained [ 14 C]-radioactivity; “penetrated” was calculated based on [ 14 C]-radioactivity in media (in vitro) or excreta + tissues (in vivo). Human skin absorbed EH-TBB (24 ± 1%) while 0.2 ± 0.1% penetrated skin. Rat skin absorbed more (51 ± 10%) and was more permeable (2 ± 0.5%) to EH-TBB in vitro; maximal EH-TBB flux was 11 ± 7 and 102 ± 24 pmol-eq/cm 2 /h for human and rat skin, respectively. In vivo, 27 ± 5% was absorbed and 13% reached systemic circulation after 24 h (maximum flux was 464 ± 65 pmol-eq/cm 2 /h). BEH-TEBP in vitro penetrance was minimal (< 0.01%) for rat or human skin. BEH-TEBP absorption was 12 ± 11% for human skin and 41 ± 3% for rat skin. In vivo, total absorption was 27 ± 9%; 1.2% reached systemic circulation. In vitro maximal BEH-TEBP flux was 0.3 ± 0.2 and 1 ± 0.3 pmol-eq/cm 2 /h for human and rat skin; in vivo maximum flux for rat skin was 16 ± 7 pmol-eq/cm 2 /h. EH-TBB was metabolized in rat and human skin to tetrabromobenzoic acid. BEH-TEBP-derived [ 14 C]-radioactivity in the perfusion media could not be characterized. < 1% of the dose of EH-TBB and BEH-TEHP is estimated to reach the systemic circulation following human dermal exposure under the conditions tested. Chemical compounds studied in this article: 2-Ethylhexyl 2,3,4,5-tetrabromobenzoate (PubChem CID: 71316600; CAS No. 183658-27-7 FW: 549.92 g/mol logP est : 7.73–8

  5. Estimation of human percutaneous bioavailability for two novel brominated flame retardants, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl) tetrabromophthalate (BEH-TEBP)

    Energy Technology Data Exchange (ETDEWEB)

    Knudsen, Gabriel A., E-mail: gabriel.knudsen@nih.gov [NCI Laboratory of Toxicology and Toxicokinetics, 111 T W Alexander Dr., Research Triangle Park, NC (United States); Hughes, Michael F. [Integrated Systems Toxicology Division, National Health and Environmental Effects Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Sanders, J. Michael; Hall, Samantha M.; Birnbaum, Linda S. [NCI Laboratory of Toxicology and Toxicokinetics, 111 T W Alexander Dr., Research Triangle Park, NC (United States)

    2016-11-15

    2-Ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB) and bis(2-ethylhexyl)tetrabromophthalate (BEH-TEBP) are novel brominated flame retardants used in consumer products. A parallelogram approach was used to predict human dermal absorption and flux for EH-TBB and BEH-TEBP. [{sup 14}C]-EH-TBB or [{sup 14}C]-BEH-TEBP was applied to human or rat skin at 100 nmol/cm{sup 2} using a flow-through system. Intact rats received analogous dermal doses. Treated skin was washed and tape-stripped to remove “unabsorbed” [{sup 14}C]-radioactivity after continuous exposure (24 h). “Absorbed” was quantified using dermally retained [{sup 14}C]-radioactivity; “penetrated” was calculated based on [{sup 14}C]-radioactivity in media (in vitro) or excreta + tissues (in vivo). Human skin absorbed EH-TBB (24 ± 1%) while 0.2 ± 0.1% penetrated skin. Rat skin absorbed more (51 ± 10%) and was more permeable (2 ± 0.5%) to EH-TBB in vitro; maximal EH-TBB flux was 11 ± 7 and 102 ± 24 pmol-eq/cm{sup 2}/h for human and rat skin, respectively. In vivo, 27 ± 5% was absorbed and 13% reached systemic circulation after 24 h (maximum flux was 464 ± 65 pmol-eq/cm{sup 2}/h). BEH-TEBP in vitro penetrance was minimal (< 0.01%) for rat or human skin. BEH-TEBP absorption was 12 ± 11% for human skin and 41 ± 3% for rat skin. In vivo, total absorption was 27 ± 9%; 1.2% reached systemic circulation. In vitro maximal BEH-TEBP flux was 0.3 ± 0.2 and 1 ± 0.3 pmol-eq/cm{sup 2}/h for human and rat skin; in vivo maximum flux for rat skin was 16 ± 7 pmol-eq/cm{sup 2}/h. EH-TBB was metabolized in rat and human skin to tetrabromobenzoic acid. BEH-TEBP-derived [{sup 14}C]-radioactivity in the perfusion media could not be characterized. < 1% of the dose of EH-TBB and BEH-TEHP is estimated to reach the systemic circulation following human dermal exposure under the conditions tested. Chemical compounds studied in this article: 2-Ethylhexyl 2,3,4,5-tetrabromobenzoate (PubChem CID: 71316600; CAS No. 183658

  6. Obtention of Samarium and Gadolinium concentrates by solvent extraction using mono-2-ethylhexyl ester of 2-ethylhexyl phosphonic acid; Obtencao de concentrados de samario e gadolinio via extracao por solventes com o ester mono-2-etilhexil do acido 2-etilhexilfosfonico

    Energy Technology Data Exchange (ETDEWEB)

    Miranda, Junior, Pedro

    1996-07-01

    The rare earth chlorides solution employed in this study, which is constituted by medium and heavy fractions, is derived from monazite processing accomplished by NUCLEMON-Mineroquimica (SP). This solution shows an acidity about 1.18 M and 189 g/L of rare earth oxides, containing as main constituents: Sm(34.55%), Gd(23.85%), Dy (6.82%), and Y (24.45%). It was used, as organic phase, 2-ethylhexyl phosphonic acid, mono-2-ethylhexylester diluted to 1 M in isododecane. (author)

  7. Characterization of polypyrrole films electrosynthesized onto titanium in the presence of sodium bis(2-ethylhexyl) sulfosuccinate (AOT)

    International Nuclear Information System (INIS)

    Flamini, D.O.; Saidman, S.B.

    2010-01-01

    Films of polypyrrole (PPy) were successfully electrosynthesized onto titanium in neutral and alkaline solutions of sodium bis(2-ethylhexyl) sulfosuccinate (Aerosol OT or AOT) by potentiodynamic, galvanostatic and potentiostatic techniques. Results of the characterization of the films by cyclic voltammetry, scanning electron microscopy (SEM) and adhesion measurements are presented. It was found that the AOT molecule remains entrapped within the polymer matrix. The initial growth of the polymer produces electroactive toroidal deposits whereas for electropolymerization of longer duration the typical globular structure is developed. Adherence to Ti increases with deposition time and this result is interpreted as a consequence of the growth of a composite PPy/Ti oxide.

  8. Spectrophotometric study of neptunium (VI) complexation by nitrate ions; Etude par spectrophotometrie de la complexation du neptunium au degre d'oxydation (VI) par les ions nitrates

    Energy Technology Data Exchange (ETDEWEB)

    Pochon, P. [CEA/VALRHO - site de Marcoule, Dept. de Recherche en Retraitement et en Vitrification (DRRV), 30 - Marcoule (France)]|[Conservatoire National des Arts et Metiers (CNAM), 75 - Paris (France)]|[Centre Regional Associe de Lyon, 69 (France)

    2000-07-01

    Neptunium(VI) complexation by nitrate ions was investigated by visible and near-infrared spectrophotometry, a technique suitable for observing the appearance and evolution of the species in solution. In the absence of reference spectra for Np(VI) nitrate- complexes, mathematical (factor analysis) tools were used to interpret the spectra. These chemo-metric techniques were first tested and validated on a simpler chemical system: Np(VI)complexation by the SiW{sub 11}O{sub 39}{sup 8-} anion. The test media used to investigate Np(VI) nitrate- complexes generally contain nitrate and perchlorate salts at high concentrations (high ionic strength). Media effects arising from the presence of cations, acidity or the perchlorate ion concentration are therefore significant, and no doubt account for the scattered values of the complexation constants published in the literature. The evolution of the neptunium spectra according to the parameters of the reaction medium illustrated these effects and allowed them to be quantified by a global 'perturbation constant'. In order to minimize the spectrum modifications due to media effects, the neptunium nitrate-complexes were studied at constant ionic strength in weak acidic media (2 mol.kg{sup -1}{sub H2O}) in the presence of sodium salts. The bulk formation constants and the spectrum of the NpO{sub 2}(NO{sub 3}){sup +} complex were determined for ionic strength values of 2.2, 4, 6 and 8 mol.kg{sup -1}{sub H2O}. The constants remained on the same order of magnitude regardless of the ionic strength; the thermodynamic constant {beta}{sub 1}{sup 0} determined from them according to specific interaction theory is thus probably of little significance. Conversely, the bulk constants can be corrected for the effects of the perchlorate ions by taking the global 'perturbation constant' into account. (author)

  9. Comparative study on the migration of di-2-ethylhexyl phthalate (DEHP) and tri-2-ethylhexyl trimellitate (TOTM) into blood from PVC tubing material of a heart-lung machine.

    Science.gov (United States)

    Eckert, Elisabeth; Münch, Frank; Göen, Thomas; Purbojo, Ariawan; Müller, Johannes; Cesnjevar, Robert

    2016-02-01

    Medical devices like blood tubing often consist of PVC material that requires the addition of plasticizers. These plasticizers may migrate into the blood leading to an exposure of the patients. In this study the migration behavior of three different blood tubing sets (PVC material with two different plasticizers and silicone as control material) applied on a heart-lung machine standardly used for cardiopulmonary bypass (CPB) in children was studied. We analyzed the total plasticizer migration by analysis of both, the parent compounds as well as their primary degradation products in blood. Additionally, the total mass loss of the tubing over perfusion time was examined. The PVC tubing plasticized with DEHP (di-2-ethylhexyl phthalate) was found to have the highest mass loss over time and showed a high plasticizer migration rate. In comparison, the migration of TOTM (tri-2-ethylhexyl trimellitate) and its primary degradation products was found to be distinctly lower (by a factor of approx. 350). Moreover, it was observed that the storage time of the tubing affects the plasticizer migration rates. In conclusion, the DEHP substitute TOTM promises to be an effective alternative plasticizer for PVC medical devices particularly regarding the decreased migration rate during medical procedures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Study of the extraction mechanisms by TBP saturated by uranyl nitrate; Etude des mecanismes d'extraction du TBP sature par le nitrate d'uranyle

    Energy Technology Data Exchange (ETDEWEB)

    Meze, F

    2004-02-15

    This work deals with a particular phenomenon likely to occur in the nuclear waste reprocessing process PUREX. It was shown earlier by Russian works that the extractant molecule, tributyl phosphate (TBP), saturated by uranyl nitrate keeps its extraction capacities for nitric acid and tetravalent actinides. This study is composed of three parts. Firstly, some liquid-liquid extraction experiments were conducted to verify the ability of TBP saturated by uranyl nitrate to conserve its extraction capacities for nitric acid. Then, during these experiments, the UV and infrared spectra of both phases were recorded to obtain the organic phase speciation. At last, the informations gathered during the experimental part were used to build a general species distribution model of the H{sub 2}O/HNO{sub 3}/UO{sub 2}(NO{sub 3}){sub 2}/TBP system. (author)

  11. Hydrolysis in the organic phase during the extraction of alkali metal halides and water by copper bis(2-ethylhexyl)phosphate

    International Nuclear Information System (INIS)

    Golovanov, V.I.; Kuznetsov, S.M.

    2001-01-01

    Experimental data on extraction of halides, among which are LiCl and CsCl, and water by copper di-(2-ethylhexyl)phosphate solutions in respect to hydrolysis mechanism of reaction are generalized. Copper di-(2-ethylhexyl)phosphate manifests properties of ionogen colloidal surfactant in water. Extraction of halides by copper di-(2-ethylhexyl)phosphate was shown to be visualized by the process of capsule formation in MHal molecules, as well as in hydrolyzed MOH and HHal forms of electrolyte by Cu 4 (D2EHF) 8 · hH 2 O clathrate-like micellar associates. The model of hydrolysis mechanism is not different from proposed earlier model of electrolyte extraction with their partial dissociation in organic phase [ru

  12. Extraction of plutonium(IV) by bis(2-ethylhexyl) sulfoxide: a novel branched-chain extractant (Preprint No. ST.23)

    International Nuclear Information System (INIS)

    Shukla, J.P.; Kedari, C.S.

    1989-01-01

    Di-n-alkyl sulfoxides offer certain distint advantages over other common extractants for use in actinides separation particularly in the presence of high radiation fields. Despite widespread interest in these extractants, practical applications of such sulfoxides in nuclear fuel reprocessing have been seriously hampered owing to their poor solubility in common aliphatic hydrocarbon diluents. Recently a promising new branched-chain sulfoxide extractant, bis( 2-ethylhexyl) sulfoxide (BESO) has been introduced as a novel extracting agent for uranium. It possesses almost all the advantages of other sulfoxides, but excels the rest in terms of its complete miscibility with dodecane and the highest Ksub(H) value reported for any sulfoxide. As a part of comprehensive program to explore its analytical usefulness, data concerning preliminary studies on the extraction of plutonium with BESO form nitric acid solutions are reported. (author)

  13. Health hazards associated with the use of di-(2-ethylhexyl) phthalate (commonly referred to as DOP) in HEPA filter test

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    Di-(2-ethylhexyl) phthalate (DEHP), commonly referred to as di-octyl phthalate, is an important production chemical in the US. In addition to its major use as an additive in plastics, DEHP is widely used to evaluate the effectiveness of high efficiency particulate air (HEPA) filters. Historically, DEHP was also used in quantitative fit testing for respirators. Evaluations of this compound a decade ago showed that it can induce hepatocellular carcinomas in laboratory animals. Although most Department of Energy (DOE) facilities have since discontinued using DEHP in respirator fit testing, DEHP continues to be used for evaluating HEPA filters. This report summarizes available information on the toxicity, mutagenicity, carcinogenicity, and other hazards and problems posed by DEHP, specifically with reference to HEPA filter testing. Information on work practice improvements as well as the availability and suitability of DEHP substitutes are also presented. This material should assist the DOE in the safe use of this material.

  14. Copper mediated controlled radical copolymerization of styrene and2-ethylhexyl acrylate and determination of their reactivity ratios.

    Directory of Open Access Journals (Sweden)

    Bishnu Prasad Koiry

    2014-10-01

    Full Text Available Copolymerization is an important synthetic tool to prepare polymers with desirable combination of properties which are difficult to achieve from the different homopolymers concerned. This investigation reports the copolymerization of 2-ethylhexyl acrylate (EHA and styrene using copper bromide (CuBr as catalyst in combination with N,N,N’,N,N- pentamethyldiethylenetriamine (PMDETA as ligand and 1-phenylethyl bromide (PEBr as initiator. Linear kinetic plot and linear increase in molecular weights versus conversion indicate that copolymerization reactions were controlled. The copolymer composition was calculated using 1H NMR studies. The reactivity ratio of styrene and EHA (r1 and r2 were determined using the Finemann-Ross (FR, inverted Finemann-Ross (FR and Kelen-Tudos (KT methods. Thermal properties of the copolymers were also studied by using TGA and DSC analysis.

  15. Di-(2-ethylhexyl)-phthalate disrupts pituitary and testicular hormonal functions to reduce sperm quality in mature goldfish

    DEFF Research Database (Denmark)

    Golshan, M.; Hatef, A.; Socha, M.

    2015-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) interferes with male reproductive endocrine system in mammals, however its effects on fish reproduction are largely unknown. We evaluated sperm quality and investigated reproductive endocrine system in mature goldfish (Carassius auratus) exposed to nominal 1, 10......, and 100μg/L DEHP. To examine DEHP estrogenic activity, one group of goldfish was exposed to 17β-estradiol (5μg/L E2) for comparison. Following 30d of exposure, sperm production was decreased and suppressed in DEHP and E2 treated goldfish, respectively. Sperm motility and velocity were decreased...... in goldfish exposed to 100 and 10μg/L DEHP at 15s post-sperm activation, respectively. Compared to control, 11-ketotestosterone (11-KT) levels were decreased at 10 and 1μg/L DEHP at day 15 and 30, respectively. In E2 treated goldfish, 11-KT levels were decreased compared to control during the period...

  16. Exposure to di-2-ethylhexyl terephthalate in a convenience sample of U.S. adults from 2000 to 2016.

    Science.gov (United States)

    Silva, Manori J; Wong, Lee-Yang; Samandar, Ella; Preau, James L; Calafat, Antonia M; Ye, Xiaoyun

    2017-10-01

    Di-2-ethylhexyl terephthalate (DEHTP), a structural isomer of di-2-ethylhexyl phthalate (DEHP), is a plasticizer used in a variety of commercial applications, but data on Americans' exposure to DEHTP do not exist. We investigated the exposure to DEHTP in a convenience group of U.S. adults by analyzing urine collected anonymously in 2000 (N = 44), 2009 (N = 61), 2011 (N = 81), 2013 (N = 92), and 2016 (N = 149) for two major DEHTP oxidative metabolites: mono-2-ethyl-5-carboxypentyl terephthalate (MECPTP) and mono-2-ethyl-5-hydroxyhexyl terephthalate (MEHHTP). For comparison, we also quantified the analogous DEHP metabolites mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) and mono-2-ethyl-5-carboxypentyl phthalate (MECPP). We detected MECPTP, MEHHP, and MECPP in all samples collected in 2016 with geometric means of 13.1, 4.1, and 6.7 ng/mL, respectively; we detected MEHHTP in 91% of the samples (geometric mean = 3.1 ng/mL). Concentrations of MECPTP correlated well with those of MEHHTP (R 2  = 0.8, p  0.05) suggesting different sources of exposure to DEHP and DEHTP. We also evaluated the fraction of the metabolites eliminated in their free (i.e., unconjugated) form. The median percent of unconjugated species was lower for the DEHP metabolites (MECPP [45.5%], MEHHP [1.9%]) compared to the DEHTP metabolites (MECPTP [98.8%], MEHHTP [21.2%]). Contrary to the downward trend from 2000 to 2016 in urinary concentrations of MEHHP and MECPP, we observed an upward trend for MEHHTP and MECPTP. These preliminary data suggest that exposure to DEHTP may be on the rise. Nevertheless, general population exposure data using MEHHTP and MECPTP as exposure biomarkers would increase our understanding of exposure to DEHTP, one of the known DEHP alternatives.

  17. Mono-(2-ethylhexyl) phthalate (MEHP) regulates glucocorticoid metabolism through 11β-hydroxysteroid dehydrogenase 2 in murine gonadotrope cells

    International Nuclear Information System (INIS)

    Hong, Dun; Li, Xing-Wang; Lian, Qing-Quan; Lamba, Pankaj; Bernard, Daniel J.; Hardy, Dianne O.; Chen, Hai-Xiao; Ge, Ren-Shan

    2009-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) and its metabolite mono-(2-ethylhexyl) phthalate (MEHP) have been classified as toxicants to the reproductive system at the testis level and DEHP may also impair reproductive axis function at the pituitary levels. However, MEHP is 10-fold more potent than DEHP in toxicity and little is known about the toxicological effect of MEHP on pituitary. In this study, we demonstrated that 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2), not 11β-HSD1, is strongly expressed in murine gonadotrope LβT2 cells. Interestingly, MEHP inhibited Hsd11b2 mRNA level and 11β-HSD2 enzyme activity in LβT2 cells at as low as 10 -7 M. Corticosterone (CORT) at a concentration of 10 -6 M significantly inhibited LβT2 cell proliferation after 2-day culture, and 10 -6 M RU486, an antagonist of glucocorticoid receptor (GR), reversed this inhibition. However, in the presence of 10 -5 or 10 -4 M MEHP, the minimal concentration of CORT to inhibit the proliferation of LβT2 cells was lowered to 10 -7 M, and 10 -6 M RU486 was not able to completely reverse the CORT effect. In conclusion, along with the regulation of GR, 11β-HSD2 may have a key role in glucocorticoid metabolism in LβT2 cells. MEHP may participate in the glucocorticoid metabolism in LβT2 cells through inhibition of 11β-HSD2 enzyme activity. Such perturbation may be of pathological significance as MEHP may interfere with the reproductive system at pituitary level through regulation of glucocorticoid metabolism, especially in neonates with higher risk of phthalates exposure.

  18. Formation of chlorinated breakdown products during degradation of sunscreen agent, 2-ethylhexyl-4-methoxycinnamate in the presence of sodium hypochlorite.

    Science.gov (United States)

    Gackowska, Alicja; Przybyłek, Maciej; Studziński, Waldemar; Gaca, Jerzy

    2016-01-01

    In this study, a new degradation path of sunscreen active ingredient, 2-ethylhexyl-4-methoxycinnamate (EHMC) and 4-methoxycinnamic acid (MCA) in the presence of sodium hypochlorite (NaOCl), was discussed. The reaction products were detected using gas chromatography-mass spectrometry (GC-MS). Since HOCl treatment leads to more polar products than EHMC, application of polar extracting agents, dichloromethane and ethyl acetate/n-hexane mixture, gave better results in terms of chlorinated breakdown products identification than n-hexane. Reaction of EHMC with HOCl lead to the formation of C=C bridge cleavage products such as 2-ethylhexyl chloroacetate, 1-chloro-4-methoxybenzene, 1,3-dichloro-2-methoxybenzene, and 3-chloro-4-methoxybenzaldehyde. High reactivity of C=C bond attached to benzene ring is also characteristic for MCA, since it can be converted in the presence of HOCl to 2,4-dichlorophenole, 2,6-dichloro-1,4-benzoquinone, 1,3-dichloro-2-methoxybenzene, 1,2,4-trichloro-3-methoxybenzene, 2,4,6-trichlorophenole, and 3,5-dichloro-2-hydroxyacetophenone. Surprisingly, in case of EHMC/HOCl/UV, much less breakdown products were formed compared to non-UV radiation treatment. In order to describe the nature of EHMC and MCA degradation, local reactivity analysis based on the density functional theory (DFT) was performed. Fukui function values showed that electrophilic attack of HOCl to the C=C bridge in EHMC and MCA is highly favorable (even more preferable than phenyl ring chlorination). This suggests that HOCl electrophilic addition is probably the initial step of EHMC degradation.

  19. Gas chromatographic-mass spectrometric analysis of di(2-ethylhexyl) phthalate and its metabolites in hepatic microsomal incubations

    Energy Technology Data Exchange (ETDEWEB)

    Pietrogrande, M.C.; Rossi, D.; Paganetto, G

    2003-03-17

    A method is reported for the determination of di(2-ethylhexyl) phthalate (DEHP) and its metabolites in in vitro metabolism studies. Gas chromatography-mass spectrometry (GC-MS) analysis allows separation of 18 by-products of DEHP metabolism. On the basis of retention time and specific mass spectra m/z values, three classes of compounds can be identified: (i) alcohols as hydrolysis product; (ii) acids produced by alcohol oxidation; (iii) compounds retaining phthalic moiety. The chromatogram can also be acquired in SIM mode at m/z 149 resulting in 13 well-separated chromatographic peaks: from retention time and mass spectra it can be inferred that the main peaks correspond to mono(2-ethylhexyl) phthalate (MEHP) and ({omega}-1)-hydroxyl-MEHP. The kinetics of DEHP metabolism was studied using an S9 Aroclor-induced liver fraction as in vitro model and following incubation assay after 20, 40, 60 and 90 min. The composition of incubation mixtures can be quantitatively evaluated from selected ion monitoring chromatograms at m/z 149: the by-product concentration increases during the incubation time, as a consequence of DEHP degradation. During the incubation test a significant conversion of DEHP into MEHP is observed: a conversion yield of 10, 13, 16 and 20% of the original DEHP is obtained after 20, 40, 60 and 90 min, respectively. The metabolic conversion of DEHP to MEHP explains the endocrine-disrupting activity of the original DEHP; moreover, it has been demonstrated that MEHP and its ({omega}-1)-oxidation metabolite induce peroxisome proliferation. This result strengthens the suggestion that the study of DEHP metabolic pathway is fundamental to better understanding its toxicological behavior.

  20. Toxicity of xenobiotics during sulfate, iron, and nitrate reduction in primary sewage sludge suspensions

    DEFF Research Database (Denmark)

    Elsgaard, Lars

    2010-01-01

    The effect and persistence of six organic xenobiotics was tested under sulfate-, iron-, and nitrate-reducing conditions in primary sewage sludge suspensions. The xenobiotics tested were acenaphthene, phenanthrene, di(2-ethylhexyl)phthalate (DEHP), 4-nonylphenol (4-NP), linear alkylbenzene sulfonate...

  1. Maximum permissible concentrations and negligible concentrations for phthalates (dibutylphthalate and di(2-ethylhexyl)phthlate), with emphasis on endocrine disruptive properties

    NARCIS (Netherlands)

    Wezel AP van; Posthumus R; Vlaardingen P van; Crommentuijn T; Plassche EJ van de; CSR

    This report presents maximal permissible concentrations (MPCs) and negligible concentrations (NCs) are derived for di-n-butylphthalate (DBP) and di(2-ethylhexyl)phthalate (DEHP). Phthalates are often mentioned as suspected endocrine disrupters. Data with endpoints related to the endocrine or

  2. HEPATOCYTE EXPRESION OF TUMOR ASSOCIATED ALDEHYDE DEHYDROGENASE (ALDH-3) AND P21 RAS FOLLOWING DIETHYLNITROSAMINE (DEN) INITIATION AND CHRONIC EXPOSURE TO DI(2-ETHYLHEXYL) PHTHALATE (DHEP)

    Science.gov (United States)

    Phthalate esters such as di(2-ethylhexyl)phthalate (DEHP)either promote or inhibit rat liver tumorigenesis depending on the carcinogenesis protocol. In this study, we examined the expression of two histochemical markers, the tumor associated isozyme of aldehyde dehydrogenase (ALD...

  3. Use of Mass Spectrometry for Identification of Biomarkers of Exposure to the Flame Retardant DI(2-Ethylhexyl)-2,3,4,5-Tetrabromophthlate

    Science.gov (United States)

    Di-(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH) is one component in the technical formulation of Firemaster 550, a fire retardant used after phasing out certain polybrominated diphenyl ethers. Firemaster 550 is used widely and its use may result in human exposure to TBPH. To...

  4. Data from one test "Semi-Volatile Organic Compound Small Chamber for bis (2-Ethylhexyl) phthalate in Vinyl Flooring Test 2"

    Science.gov (United States)

    This data was generated from a small chamber bis(2-ethylhexyl) phthalate (DEHP) emission test. It was to participate an interaboratory study of DEHP emissions from vinyl flooring in a SVOC emission chamber organized by Virginia Polytechnic Institute and State University (VT).

  5. Kinetics of di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate in blood and of DEHP metabolites in urine of male volunteers after single ingestion of ring-deuterated DEHP

    Energy Technology Data Exchange (ETDEWEB)

    Kessler, Winfried, E-mail: kessler@helmholtz-muenchen.de [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Numtip, Wanwiwa [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Völkel, Wolfgang; Seckin, Elcim [Department of Chemical Safety and Toxicology, Bavarian Health and Food Safety Authority, Pfarrstrasse 3, D-80538 München (Germany); Csanády, György A. [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); Institut für Toxikologie und Umwelthygiene, Technische Universität München, München (Germany); Pütz, Christian [Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, D-85764 Neuherberg (Germany); and others

    2012-10-15

    The plasticizer di(2-ethylhexyl) phthalate (DEHP) is suspected to induce antiandrogenic effects in men via its metabolite mono(2-ethylhexyl) phthalate (MEHP). However, there is only little information on the kinetic behavior of DEHP and its metabolites in humans. The toxikokinetics of DEHP was investigated in four male volunteers (28–61 y) who ingested a single dose (645 ± 20 μg/kg body weight) of ring-deuterated DEHP (DEHP-D{sub 4}). Concentrations of DEHP-D{sub 4}, of free ring-deuterated MEHP (MEHP-D{sub 4}), and the sum of free and glucuronidated MEHP-D{sub 4} were measured in blood for up to 24 h; amounts of the monoesters MEHP-D{sub 4}, ring-deuterated mono(2-ethyl-5-hydroxyhexyl) phthalate and ring-deuterated mono(2-ethyl-5-oxohexyl) phthalate were determined in urine for up to 46 h after ingestion. The bioavailability of DEHP-D{sub 4} was surprisingly high with an area under the concentration-time curve until 24 h (AUC) amounting to 50% of that of free MEHP-D{sub 4}. The AUC of free MEHP-D{sub 4} normalized to DEHP-D{sub 4} dose and body weight (AUC/D) was 2.1 and 8.1 times, that of DEHP-D{sub 4} even 50 and 100 times higher than the corresponding AUC/D values obtained earlier in rat and marmoset, respectively. Time courses of the compounds in blood and urine of the volunteers oscillated widely. Terminal elimination half-lives were short (4.3–6.6 h). Total amounts of metabolites in 22-h urine are correlated linearly with the AUC of free MEHP-D{sub 4} in blood, the parameter regarded as relevant for risk assessment. -- Highlights: ► After DEHP intake, DEHP and MEHP in blood show oscillating time courses. ► Dose-related blood levels of DEHP are 50 times higher in humans than in rats. ► Dose-related blood levels of free MEHP are 2 times higher in humans than in rats. ► Elimination of DEHP and its metabolites is short with half-lives of 4.3-6.6 h.

  6. Hepatic and intestinal glucuronidation of mono(2-ethylhexyl) phthalate, an active metabolite of di(2-ethylhexyl) phthalate, in humans, dogs, rats, and mice: an in vitro analysis using microsomal fractions.

    Science.gov (United States)

    Hanioka, Nobumitsu; Isobe, Takashi; Kinashi, Yu; Tanaka-Kagawa, Toshiko; Jinno, Hideto

    2016-07-01

    Mono(2-ethylhexyl) phthalate (MEHP) is an active metabolite of di(2-ethylhexyl) phthalate (DEHP) and has endocrine-disrupting effects. MEHP is metabolized into glucuronide by UDP-glucuronosyltransferase (UGT) enzymes in mammals. In the present study, the hepatic and intestinal glucuronidation of MEHP in humans, dogs, rats, and mice was examined in an in vitro system using microsomal fractions. The kinetics of MEHP glucuronidation by liver microsomes followed the Michaelis-Menten model for humans and dogs, and the biphasic model for rats and mice. The K m and V max values of human liver microsomes were 110 µM and 5.8 nmol/min/mg protein, respectively. The kinetics of intestinal microsomes followed the biphasic model for humans, dogs, and mice, and the Michaelis-Menten model for rats. The K m and V max values of human intestinal microsomes were 5.6 µM and 0.40 nmol/min/mg protein, respectively, for the high-affinity phase, and 430 µM and 0.70 nmol/min/mg protein, respectively, for the low-affinity phase. The relative levels of V max estimated by Eadie-Hofstee plots were dogs (2.0) > mice (1.4) > rats (1.0) ≈ humans (1.0) for liver microsomes, and mice (8.5) > dogs (4.1) > rats (3.1) > humans (1.0) for intestinal microsomes. The percentages of the V max values of intestinal microsomes to liver microsomes were mice (120 %) > rats (57 %) > dogs (39 %) > humans (19 %). These results suggest that the metabolic abilities of UGT enzymes expressed in the liver and intestine toward MEHP markedly differed among species, and imply that these species differences are strongly associated with the toxicity of DEHP.

  7. The Influence of Lactic Acid Concentration on the Separation of Light Rare Earth Elements by Continuous Liquid-Liquid Extraction with 2-Ethylhexyl Phosphonic Acid Mono-2-ethylhexyl Ester

    Science.gov (United States)

    de Carvalho Gomes, Rafael; Seruff, Luciana Amaral; Scal, Maira Labanca Waineraich; Vera, Ysrael Marrero

    2018-02-01

    The separation of rare earth elements (REEs) using solvent extraction adding complexing agents appears to be an alternative to saponification of the extractant. We evaluated the effect of lactic acid concentration on didymium (praseodymium and neodymium) and lanthanum extraction with 2-ethylhexyl phosphonic acid mono-2-ethyl hexyl ester [HEH(EHP)] as extractant. First, we investigated in batch experiments the separation of lanthanum (La) and didymium (Pr and Nd) using McCabe-Thiele diagrams to estimate the number of extraction stages when the feed solution was or was not conditioned with lactic acid. Additionally, we conducted continuous liquid-liquid extraction experiments and evaluated the influence of lactic acid concentration on the REE extraction and separation. The tests showed that the extraction percentage of REEs and the separation factor Pr/La increased when the lactic acid concentration increased, but the didymium purity decreased. Lanthanum, praseodymium, and neodymium extraction rate were 23.0, 89.7, and 99.2 pct, respectively, with 1:1 aqueous/organic volume flow rate and feed solution doped with 0.52 mol L-1 lactic acid. The highest didymium purity reached was 92.0 pct with 0.26 mol L-1 lactic acid concentration.

  8. Studies on supercritical fluid extraction behaviour of uranium and thorium nitrates using amides

    International Nuclear Information System (INIS)

    Sujatha, K.; Kumar, R.; Sivaraman, N.; Srinivasan, T.G.; Vasudeva Rao, P.R.

    2007-01-01

    Supercritical fluid extraction studies of uranyl nitrate and thorium nitrate in mixture were carried out using various amides such as N,N-di(2-ethylhexyl) isobutyramide (D2EHIBA),N,N-dihexyl octanamide (DHOA) and Diisooctyl Butanamide (DiOBA). These studies established a preferential extraction of uranium over thorium. Among the various amides studied, D2EHIBA offered the best rate of preferential extraction of uranium over thorium. (author)

  9. Determination and Pharmacokinetics of Di-(2-ethylhexyl Phthalate in Rats by Ultra Performance Liquid Chromatography with Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Tung-Hu Tsai

    2013-09-01

    Full Text Available Di-(2-ethylhexyl phthalate (DEHP is used to increase the flexibility of plastics for industrial products. However, the illegal use of the plasticizer DEHP in food and drinks has been reported in Taiwan in 2011. In order to assess the exact extent of the absorption of DEHP via the oral route, the aim of this study is to develop a reliable and validated ultra performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS method to evaluate the oral bioavailability of DEHP in rats. The optimal chromatographic separation of DEHP and butyl benzyl phthalate (BBP; used as internal standard were achieved on a C18 column. The mobile phase was consisted of 5 mM ammonium acetate-methanol (11:89, v/v with a flow rate of 0.25 mL/min. The monitoring ion transitions were m/z 391.4 → 149.0 for DEHP and m/z 313.3 → 149.0 for BBP. The mean matrix effects of DEHP at low, medium and high concentrations were 94.5 ± 5.7% and 100.1 ± 2.3% in plasma and feces homogenate samples, respectively. In conclusion, the validated UPLC-MS/MS method is suitable for analyzing the rat plasma sample of DEHP and the oral bioavailability of DEHP was about 7% in rats.

  10. Maternal exposure to di-(2-ethylhexyl) phthalate exposure deregulates blood pressure, adiposity, cholesterol metabolism and social interaction in mouse offspring.

    Science.gov (United States)

    Lee, Kuan-I; Chiang, Chin-Wei; Lin, Hui-Ching; Zhao, Jin-Feng; Li, Cheng-Ta; Shyue, Song-Kun; Lee, Tzong-Shyuan

    2016-05-01

    Long-term exposure to di-(2-ethylhexyl) phthalate (DEHP) is highly associated with carcinogenicity, fetotoxicity, psychological disorders and metabolic diseases, but the detrimental effects and mechanisms are not fully understood. We investigated the effect of exposing mouse mothers to DEHP, and the underlying mechanism, on blood pressure, obesity and cholesterol metabolism as well as psychological and learning behaviors in offspring. Tail-cuff plethysmography was used for blood pressure measurement; Western blot used was for phosphorylation and expression of protein; hematoxylin and eosin staining, Nissl staining and Golgi staining were used for histological examination. The serum levels of cholesterol, triglycerides and glucose were measured by blood biochemical analysis. Hepatic cholesterol and triglyceride levels were assessed by colorimetric assay kits. Offspring behaviors were evaluated by open-field activity, elevated plus maze, social preference test and Morris water maze. Maternal DEHP exposure deregulated the phosphorylation of endothelial nitric oxide synthase and upregulated angiotensin type 1 receptor in offspring, which led to increased blood pressure. It led to obesity in offspring by increasing the size of adipocytes in white adipose tissue and number of adipocytes in brown adipose tissue. It increased the serum level of cholesterol in offspring by decreasing the hepatic capacity for cholesterol clearance. The impaired social interaction ability induced by maternal DEHP exposure might be due to abnormal neuronal development. Collectively, our findings provide new evidence that maternal exposure to DEHP has a lasting effect on the physiological functions of the vascular system, adipose tissue and nerve system in offspring.

  11. Comparative studies of the influence of cyclodextrins on the stability of the sunscreen agent, 2-ethylhexyl-p-methoxycinnamate.

    Science.gov (United States)

    Scalia, Santo; Casolari, Alberto; Iaconinoto, Antonietta; Simeoni, Silvia

    2002-11-07

    The effects of beta-cyclodextrin (beta-CD) and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the base-catalyzed degradation and light-induced decomposition of the sunscreen agent, trans-2-ethylhexyl-p-methoxycinnamate (trans-EHMC) were investigated. Reversed-phase liquid chromatography was used to study the interaction between natural and modified cyclodextrins, added to the mobile phase, and the sunscreen. Among the available cyclodextrins (beta-CD, HP-beta-CD, hydroxypropyl-alpha-cyclodextrin and hydroxypropyl-gamma-cyclodextrin), only HP-beta-CD and beta-CD produced a significant decrease in the chromatographic retention of trans-EHMC. The complexation of the sunscreen agent with HP-beta-CD and beta-CD was confirmed by thermal analysis and nuclear magnetic resonance spectroscopy. beta-CD depressed the decomposition of trans-EHMC in alkaline solutions more effectively than HP-beta-CD. Moreover, the irradiation-induced degradation of the sunscreen agent in emulsion vehicles was reduced by complexation with beta-CD (the extent of degradation was 26.1% for the complex compared to 35.8% for free trans-EHMC) whereas HP-beta-CD had no significant effect. Therefore, the complex of beta-CD with trans-EHMC enhances the chemical- and photo-stability of the sunscreen agent. Moreover, it limits adverse interactions of the UV filter with other formulation ingredients.

  12. Metal extraction by alkyl substituted diphosphonic acids. Part 1. P,P'-Di(2-ethylhexyl) methanediphosphonic acid

    International Nuclear Information System (INIS)

    Chiarizia, R.; Horwitz, E.P.; Rickert, P.G.; Herlinger, A.W.

    1996-01-01

    Two novel extractants, p,p'-di(2-ethylhexyl) methanediphosphonic acid (H 2 DEH[MDP]) and p,p'-dioctyl methanediphosphonic acid (H 2 DO[MDP]) have been synthesized at high purity and yield. H 2 DEH[MDP] was selected for metal extraction studies because of its better physical properties. An investigation of the extraction of alkaline earth cations, Fe(111) and representative tri-, tetra- and hexavalent actinide ions from nitric acid solutions into o-xylene solutions of H 2 DEH[MDP] at different concentrations was performed. With a few exceptions, the acid dependencies of the extraction of the above metal species strongly resembles those measured in the uptake of the same metals by the chelating ion exchange resin Diphonix R , which contains gem-diphosphonic acid groups chemically attached to a polymeric matrix. The almost lack of acid dependency observed with Fe(III) and tetra- and hexavalent actinides indicates that these ions are chelated by H 2 DEH[MDP] mostly through the P=O groups of the extractant. With Fe(111) and the actinides, variable slopes of the extractant dependencies were measured, their values being strongly dependent on the acidity of the aqueous phase. H 2 DEH[MDP] possesses an extraordinary affinity for actinides and Fe(111). 26 refs., 7 figs

  13. Solvent extraction of Zn(II) from aqueous sulphate media by di(2-ethylhexyl) phosphoric acid in kerosene

    International Nuclear Information System (INIS)

    Begum, D.A.; Alauddin, M.; Rahman, M.S.

    2009-01-01

    The extraction equilibrium studies of Zn(II) from sulphate medium by di(2-ethylhexyl) phosphoric acid (D2EHPA, H/sub 2/A/sub 2/) in kerosene revealed that the distribution ratio (D) decreased with the increase of initial (Zn(A(II) in the aqueous phase and increased with the increase of equilibrium pH and extractant concentration. The equilibration is reached within 2 min. The species extracted into the organic phase is thought to be ZnA2, HA. The pH and extractant dependencies were about 2 and 1.67, respectively. The distribution ratio decreased with the increase in sulphate ion concentration in the aqueous phase. The extraction equilibrium reaction is suggested as Zn/sup 2+/ /sub aq/ +1.5 (H/sub 2/A/sub 2/)org - (ZnA/sub 2/, HA)org +2H/sup +/ /sub aq/. The extraction equilibrium constant (kex) for the above reaction was calculated to be 10-2.26. The extraction process was endothermic in nature having positive DH value of 16.27 kJ/mol. The loading of D2EHPA by Zn(II) is about 4.50 g of Zn(II) by 0.10 M D2EHPA. Possible reaction mechanism has been suggested based on distribution data, extractant concentration and equilibrium pH of the aqueous phase. (author)

  14. Toxic effects of polyethylene terephthalate microparticles and Di(2-ethylhexyl)phthalate on the calanoid copepod, Parvocalanus crassirostris.

    Science.gov (United States)

    Heindler, Franz M; Alajmi, Fahad; Huerlimann, Roger; Zeng, Chaoshu; Newman, Stephen J; Vamvounis, George; van Herwerden, Lynne

    2017-07-01

    Large amounts of plastic end up in the oceans every year where they fragment into microplastics over time. During this process, microplastics and their associated plasticizers become available for ingestion by different organisms. This study assessed the effects of microplastics (Polyethylene terephthalate; PET) and one plasticizer (Di(2-ethylhexyl)phthalate; DEHP) on mortality, productivity, population sizes and gene expression of the calanoid copepod Parvocalanus crassirostris. Copepods were exposed to DEHP for 48h to assess toxicity. Adults were very healthy following chemical exposure (up to 5120µg L -1 ), whereas nauplii were severely affected at very low concentrations (48h LC 50 value of 1.04 ng L -1 ). Adults exposed to sub-lethal concentrations of DEHP (0.1-0.3µg L -1 ) or microplastics (10,000-80,000 particles mL -1 ) exhibited substantial reductions in egg production. Populations were exposed to either microplastics or DEHP for 6 days with 18 days of recovery or for 24 days. Populations exposed to microplastics for 24 days significantly depleted in population size (60±4.1%, pplastic and DEHP treatments after 6 days of exposure, but not after 18 days of recovery. Hsp70-like expression showed to be unresponsive to either DEHP or microplastic exposure. Clearly, microplastics and plasticizers pose a serious threat to zooplankton and potentially to higher trophic levels. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Untersuchung der Di-(2-ethylhexyl)phthalat (DEHP)-Belastung der Allgemeinbevölkerung – Durchführung eines Human-Biomonitorings

    OpenAIRE

    Koch, Holger Martin

    2007-01-01

    i-(2-ethylhexyl)phthalat (DEHP) ist einer der bedeutendsten Weichmacher für PVC-Polymere mit Produktionszahlen im Bereich um 1 Million Tonnen pro Jahr weltweit. Als sog. äußerer Weichmacher ist DEHP nicht kovalent an den Kunststoff gebunden und blutet so mehr oder weniger schnell aus diesem aus und kann so die Umwelt, Nahrungsmittel oder den Menschen belasten. DEHP steht unter dringendem Verdacht, als Endokriner Disruptor/Modulator ins menschliche Hormonsystem einzugreifen und so eine Vielzah...

  16. Physico-mechanical, thermal and morphological properties of furfuryl alcohol/2-ethylhexyl methacrylate/halloysite nanoclay wood polymer nanocomposites (WPNCs

    Directory of Open Access Journals (Sweden)

    Md. Rezaur Rahman

    2017-07-01

    Full Text Available In this study, the physical, morphological, mechanical and thermal properties of furfuryl alcohol/2-ethylhexyl methacrylate/halloysite nanoclay wood polymer nanocomposites (FA-co-EHMA-HNC WPNCs were investigated. FA-co-EHMA-HNC WPNCs were prepared via an impregnation method and the properties of the nanocomposites were characterized through the weight percent gain, Fourier transform infrared (FT-IR spectroscopy, scanning electron microscopy (SEM, three-point flexural test, dynamic mechanical thermal analysis (DMTA, thermogravimetric analysis (TGA, differential scanning calorimetry (DSC analysis and moisture absorption test. The weight percent gain in the 50:50 FA-co-EHMA-HNC WPNC was the highest compared with the raw wood (RW and other WPNCs. The FT-IR results confirmed that polymerization took place in the nanocomposites, especially 50:50 FA-co-EHMA-HNC WPNC, which had a reduced amount of hydroxyl groups. The SEM results revealed that the 50:50 FA-co-EHMA-HNC WPNC had the smoothest and most uniform surface among all of the nanocomposites. The 50:50 FA-co-EHMA-HNC WPNC showed the highest flexural strength and modulus of elasticity. The results revealed that the storage modulus and loss modulus of the FA-co-EHMA-HNC WPNCs were higher and the tan δ of FA-co-EHMA-HNC WNPCs was lower compared with the RW. The FA-co-EHMA-HNC WPNCs exhibited the higher thermal stability in the TGA and DSC analysis. The 50:50 FA-co-EHMA-HNC WPNC exhibited remarkably lower moisture absorption compared with the RW. Overall, this study proved that the ratio 50:50 FA-co-EHMA ratio was the most suitable for introduction in the in the RW.

  17. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    Energy Technology Data Exchange (ETDEWEB)

    Hannon, Patrick R., E-mail: phannon2@illinois.edu; Brannick, Katherine E., E-mail: kbran@illinois.edu; Wang, Wei, E-mail: Wei.Wang2@covance.com; Gupta, Rupesh K., E-mail: drrupesh@yahoo.com; Flaws, Jodi A., E-mail: jflaws@illinois.edu

    2015-04-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  18. Direct and transgenerational effects of low doses of perinatal di-(2-ethylhexyl phthalate (DEHP on social behaviors in mice.

    Directory of Open Access Journals (Sweden)

    Kayla M Quinnies

    Full Text Available Di-(2-ethylhexyl phthalate (DEHP is an endocrine disrupting chemical commonly used as a plasticizer in medical equipment, food packaging, flooring, and children's toys. DEHP exposure during early development has been associated with adverse neurobehavioral outcomes in children. In animal models, early exposure to DEHP results in abnormal development of the reproductive system as well as altered behavior and neurodevelopment. Based on these data, we hypothesized that developmental exposure to DEHP would decrease social interactions and increase anxiety-like behaviors in mice in a dose-dependent manner, and that the effects would persist over generations. C57BL/6J mice consumed one of three DEHP doses (0, 5, 40, and 400 μg/kg body weight throughout pregnancy and during the first ten days of lactation. The two higher doses yielded detectable levels of DEHP metabolites in serum. Pairs of mice from control, low, and high DEHP doses were bred to create three dose lineages in the third generation (F3. Average anogenital index (AGI: anogenital distance/body weight was decreased in F1 males exposed to the low dose of DEHP and in F1 females exposed to the highest dose. In F1 mice, juvenile pairs from the two highest DEHP dose groups displayed fewer socially investigative behaviors and more exploratory behaviors as compared with control mice. The effect of DEHP on these behaviors was reversed in F3 mice as compared with F1 mice. F1 mice exposed to low and medium DEHP doses spent more time in the closed arms of the elevated plus maze than controls, indicating increased anxiety-like behavior. The generation-dependent effects on behavior and AGI suggest complex mechanisms by which DEHP directly impacts reproductive and neurobehavioral development and influences germline-inherited traits.

  19. Maternal in utero exposure to the endocrine disruptor di-(2-ethylhexyl) phthalate affects the blood pressure of adult male offspring

    Energy Technology Data Exchange (ETDEWEB)

    Martinez–Arguelles, D.B. [The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada H3G 1A4 (Canada); Department of Medicine, McGill University, Montreal, Quebec, Canada H3G 1A4 (Canada); McIntosh, M.; Rohlicek, C.V. [The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada H3G 1A4 (Canada); Department of Pediatrics, McGill University, Montreal, Quebec, Canada H3G 1A4 (Canada); Culty, M. [The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada H3G 1A4 (Canada); Department of Medicine, McGill University, Montreal, Quebec, Canada H3G 1A4 (Canada); Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada H3G 1A4 (Canada); Zirkin, B.R. [Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205 (United States); Papadopoulos, V., E-mail: vassilios.papadopoulos@mcgill.ca [The Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada H3G 1A4 (Canada); Department of Medicine, McGill University, Montreal, Quebec, Canada H3G 1A4 (Canada); Pharmacology and Therapeutics, McGill University, Montreal, Quebec, Canada H3G 1A4 (Canada); Department of Biochemistry and Molecular Biology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD 21205 (United States)

    2013-01-01

    Di-(2-ethylhexyl) phthalate (DEHP) is used industrially to add flexibility to polyvinyl chloride (PVC) polymers and is ubiquitously found in the environment, with evidence of prenatal, perinatal and early infant exposure in humans. In utero exposure to DEHP decreases circulating testosterone levels in the adult rat. In addition, DEHP reduces the expression of the angiotensin II receptors in the adrenal gland, resulting in decreased circulating aldosterone levels. The latter may have important effects on water and electrolyte balance as well as systemic arterial blood pressure. Therefore, we determined the effects of in utero exposure to DEHP on systemic arterial blood pressure in the young (2 month-old) and older (6.5 month-old) adult rats. Sprague-Dawley pregnant dams were exposed from gestational day 14 until birth to 300 mg DEHP/kg/day. Blood pressure, heart rate, and activity data were collected using an intra-aortal transmitter in the male offspring at postnatal day (PND) 60 and PND200. A low (0.01%) and high-salt (8%) diet was used to challenge the animals at PND200. In utero exposure to DEHP resulted in reduced activity at PND60. At PND200, systolic and diastolic systemic arterial pressures as well as activity were reduced in response to DEHP exposure. This is the first evidence showing that in utero exposure to DEHP has cardiovascular and behavioral effects in the adult male offspring. Highlights: ► In utero exposure to 300 mg DEHP/kg/day decreases activity at postnatal day 60. ► In utero exposure to DEHP decreases aldosterone levels at postnatal day 200. ► In utero exposure to DEHP decreases systolic blood pressure at postnatal day 200. ► An 8% salt diet recovers the decreased blood pressure at postnatal day 200.

  20. Relative sensitivity of developmental and immune parameters in juvenile versus adult male rats after exposure to di(2-ethylhexyl) phthalate

    International Nuclear Information System (INIS)

    Tonk, Elisa C.M.; Verhoef, Aart; Gremmer, Eric R.; Loveren, Henk van; Piersma, Aldert H.

    2012-01-01

    The developing immune system displays a relatively high sensitivity as compared to both general toxicity parameters and to the adult immune system. In this study we have performed such comparisons using di(2-ethylhexyl) phthalate (DEHP) as a model compound. DEHP is the most abundant phthalate in the environment and perinatal exposure to DEHP has been shown to disrupt male sexual differentiation. In addition, phthalate exposure has been associated with immune dysfunction as evidenced by effects on the expression of allergy. Male wistar rats were dosed with corn oil or DEHP by gavage from postnatal day (PND) 10–50 or PND 50–90 at doses between 1 and 1000 mg/kg/day. Androgen-dependent organ weights showed effects at lower dose levels in juvenile versus adult animals. Immune parameters affected included TDAR parameters in both age groups, NK activity in juvenile animals and TNF-α production by adherent splenocytes in adult animals. Immune parameters were affected at lower dose levels compared to developmental parameters. Overall, more immune parameters were affected in juvenile animals compared to adult animals and effects were observed at lower dose levels. The results of this study show a relatively higher sensitivity of juvenile versus adult rats. Furthermore, they illustrate the relative sensitivity of the developing immune system in juvenile animals as compared to general toxicity and developmental parameters. This study therefore provides further argumentation for performing dedicated developmental immune toxicity testing as a default in regulatory toxicology. -- Highlights: ► In this study we evaluate the relative sensitivities for DEHP induced effects. ► Results of this study demonstrate the age-dependency of DEHP toxicity. ► Functional immune parameters were more sensitive than structural immune parameters. ► Immune parameters were affected at lower dose levels than developmental parameters. ► Findings demonstrate the susceptibility of the

  1. Effect of mono-(2-ethylhexyl) phthalate on human and mouse fetal testis: In vitro and in vivo approaches

    Energy Technology Data Exchange (ETDEWEB)

    Muczynski, V. [Univ. Paris Diderot, Sorbonne Paris Cité, Laboratory of Development of the Gonads, Unit of Stem Cells and Radiation, BP 6, 92265 Fontenay-aux-Roses (France); CEA, DSV, iRCM, SCSR, LDRG, 92265 Fontenay-aux-Roses (France); INSERM, Unité 967, F-92265, Fontenay aux Roses (France); Cravedi, J.P. [INRA, INP, Université de Toulouse, UMR1331 TOXALIM, F-31027, Toulouse (France); Lehraiki, A.; Levacher, C.; Moison, D.; Lecureuil, C.; Messiaen, S. [Univ. Paris Diderot, Sorbonne Paris Cité, Laboratory of Development of the Gonads, Unit of Stem Cells and Radiation, BP 6, 92265 Fontenay-aux-Roses (France); CEA, DSV, iRCM, SCSR, LDRG, 92265 Fontenay-aux-Roses (France); INSERM, Unité 967, F-92265, Fontenay aux Roses (France); Perdu, E. [INRA, INP, Université de Toulouse, UMR1331 TOXALIM, F-31027, Toulouse (France); Frydman, R. [Service de Gynécologie-Obstétrique, Hôpital A. Béclère, Université Paris Sud F-92141 Clamart (France); Habert, R. [Univ. Paris Diderot, Sorbonne Paris Cité, Laboratory of Development of the Gonads, Unit of Stem Cells and Radiation, BP 6, 92265 Fontenay-aux-Roses (France); CEA, DSV, iRCM, SCSR, LDRG, 92265 Fontenay-aux-Roses (France); INSERM, Unité 967, F-92265, Fontenay aux Roses (France); and others

    2012-05-15

    The present study was conducted to determine whether exposure to the mono-(2-ethylhexyl) phthalate (MEHP) represents a genuine threat to male human reproductive function. To this aim, we investigated the effects on human male fetal germ cells of a 10{sup −5} M exposure. This dose is slightly above the mean concentrations found in human fetal cord blood samples by biomonitoring studies. The in vitro experimental approach was further validated for phthalate toxicity assessment by comparing the effects of in vitro and in vivo exposure in mouse testes. Human fetal testes were recovered during the first trimester (7–12 weeks) of gestation and cultured in the presence or not of 10{sup −5} M MEHP for three days. Apoptosis was quantified by measuring the percentage of Caspase-3 positive germ cells. The concentration of phthalate reaching the fetal gonads was determined by radioactivity measurements, after incubations with {sup 14}C-MEHP. A 10{sup −5} M exposure significantly increased the rate of apoptosis in human male fetal germ cells. The intratesticular MEHP concentration measured corresponded to the concentration added in vitro to the culture medium. Furthermore, a comparable effect on germ cell apoptosis in mouse fetal testes was induced both in vitro and in vivo. This study suggests that this 10{sup −5} M exposure is sufficient to induce changes to the in vivo development of the human fetal male germ cells. -- Highlights: ► 10{sup −5} M of MEHP impairs germ cell development in the human fetal testis. ► Organotypic culture is a suitable approach to investigate phthalate effects in human. ► MEHP is not metabolized in the human fetal testis. ► In mice, MEHP triggers similar effects both in vivo and in vitro.

  2. Differential cytotoxic effects of mono-(2-ethylhexyl) phthalate on blastomere-derived embryonic stem cells and differentiating neurons

    International Nuclear Information System (INIS)

    Lim, Chun Kyu; Kim, Suel-Kee; Ko, Duck Sung; Cho, Jea Won; Jun, Jin Hyun; An, Su-Yeon; Han, Jung Ho

    2009-01-01

    Potential applications of embryonic stem (ES) cells are not limited to regenerative medicine but can also include in vitro screening of various toxicants. In this study, we established mouse ES cell lines from isolated blastomeres of two-cell stage embryos and examined their potential use as an in vitro system for the study of developmental toxicity. Two ES cell lines were established from 69 blastomere-derived blastocysts (2.9%). The blastomere-derived ES (bm-ES) cells were treated with mono-(2-ethylhexyl) phthalate (MEHP) in an undifferentiated state or after directed differentiation into early neural cell types. We observed significantly decreased cell viability when undifferentiated bm-ES cells were exposed to a high dose of MEHP (1000 μM). The cytotoxic effects of MEHP were accompanied by increased DNA fragmentation, nuclear condensation, and activation of Caspase-3, which are biochemical and morphological features of apoptosis. Compared to undifferentiated bm-ES cells, considerably lower doses of MEHP (50 and 100 μM) were sufficient to induce cell death in early neurons differentiated from bm-ES cells. At the lower doses, the number of neural cells positive for the active form of Caspase-3 was greater than that for undifferentiated bm-ES cells. Thus, our data indicate that differentiating neurons are more sensitive to MEHP than undifferentiated ES cells, and that undifferentiated ES cells may have more efficient defense systems against cytotoxic stresses. These findings might contribute to the development of a new predictive screening method for assessment of hazards for developmental toxicity.

  3. Di(2-ethylhexyl) phthalate inhibits antral follicle growth, induces atresia, and inhibits steroid hormone production in cultured mouse antral follicles

    International Nuclear Information System (INIS)

    Hannon, Patrick R.; Brannick, Katherine E.; Wang, Wei; Gupta, Rupesh K.; Flaws, Jodi A.

    2015-01-01

    Di(2-ethylhexyl) phthalate (DEHP) is a ubiquitous environmental toxicant found in consumer products that causes ovarian toxicity. Antral follicles are the functional ovarian units and must undergo growth, survival from atresia, and proper regulation of steroidogenesis to ovulate and produce hormones. Previous studies have determined that DEHP inhibits antral follicle growth and decreases estradiol levels in vitro; however, the mechanism by which DEHP elicits these effects is unknown. The present study tested the hypothesis that DEHP directly alters regulators of the cell cycle, apoptosis, and steroidogenesis to inhibit antral follicle functionality. Antral follicles from adult CD-1 mice were cultured with vehicle control or DEHP (1–100 μg/ml) for 24–96 h to establish the temporal effects of DEHP on the follicle. Following 24–96 h of culture, antral follicles were subjected to gene expression analysis, and media were subjected to measurements of hormone levels. DEHP increased the mRNA levels of cyclin D2, cyclin dependent kinase 4, cyclin E1, cyclin A2, and cyclin B1 and decreased the levels of cyclin-dependent kinase inhibitor 1A prior to growth inhibition. Additionally, DEHP increased the mRNA levels of BCL2-associated agonist of cell death, BCL2-associated X protein, BCL2-related ovarian killer protein, B-cell leukemia/lymphoma 2, and Bcl2-like 10, leading to an increase in atresia. Further, DEHP decreased the levels of progesterone, androstenedione, and testosterone prior to the decrease in estradiol levels, with decreased mRNA levels of side-chain cleavage, 17α-hydroxylase-17,20-desmolase, 17β-hydroxysteroid dehydrogenase, and aromatase. Collectively, DEHP directly alters antral follicle functionality by inhibiting growth, inducing atresia, and inhibiting steroidogenesis. - Highlights: • DEHP inhibits antral follicle growth by dysregulating cell cycle regulators. • DEHP induces antral follicle atresia by dysregulating apoptosis regulators. • DEHP

  4. Relative sensitivity of developmental and immune parameters in juvenile versus adult male rats after exposure to di(2-ethylhexyl) phthalate

    Energy Technology Data Exchange (ETDEWEB)

    Tonk, Elisa C.M., E-mail: ilse.tonk@rivm.nl [Department of Toxicogenomics, Maastricht University, Maastricht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Verhoef, Aart; Gremmer, Eric R. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Loveren, Henk van [Department of Toxicogenomics, Maastricht University, Maastricht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Piersma, Aldert H. [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Institute for Risk Assessment Sciences, Veterinary Faculty, Utrecht University, Utrecht (Netherlands)

    2012-04-01

    The developing immune system displays a relatively high sensitivity as compared to both general toxicity parameters and to the adult immune system. In this study we have performed such comparisons using di(2-ethylhexyl) phthalate (DEHP) as a model compound. DEHP is the most abundant phthalate in the environment and perinatal exposure to DEHP has been shown to disrupt male sexual differentiation. In addition, phthalate exposure has been associated with immune dysfunction as evidenced by effects on the expression of allergy. Male wistar rats were dosed with corn oil or DEHP by gavage from postnatal day (PND) 10–50 or PND 50–90 at doses between 1 and 1000 mg/kg/day. Androgen-dependent organ weights showed effects at lower dose levels in juvenile versus adult animals. Immune parameters affected included TDAR parameters in both age groups, NK activity in juvenile animals and TNF-α production by adherent splenocytes in adult animals. Immune parameters were affected at lower dose levels compared to developmental parameters. Overall, more immune parameters were affected in juvenile animals compared to adult animals and effects were observed at lower dose levels. The results of this study show a relatively higher sensitivity of juvenile versus adult rats. Furthermore, they illustrate the relative sensitivity of the developing immune system in juvenile animals as compared to general toxicity and developmental parameters. This study therefore provides further argumentation for performing dedicated developmental immune toxicity testing as a default in regulatory toxicology. -- Highlights: ► In this study we evaluate the relative sensitivities for DEHP induced effects. ► Results of this study demonstrate the age-dependency of DEHP toxicity. ► Functional immune parameters were more sensitive than structural immune parameters. ► Immune parameters were affected at lower dose levels than developmental parameters. ► Findings demonstrate the susceptibility of the

  5. Di(2-ethylhexyl)phthalate (DEHP) and di-n-butylphthalate (DBP) exposure through diet in hospital patients.

    Science.gov (United States)

    Cirillo, Teresa; Fasano, Evelina; Esposito, Francesco; Montuori, Paolo; Amodio Cocchieri, Renata

    2013-01-01

    Ready-to-eat packed meals intended to hospital patients were studied over a two-weeks period to measure the contents of di-(2-ethylhexyl) phthalate (DEHP) and di-n-butylphthalate (DBP) and to evaluate their daily intake by total diet. The packaging consisted of polyethylene terephthalate (PET) dishes sealed with polypropylene (PP) foil. The DEHP mean concentrations in total meals varied from 0.061±0.028 to 0.307±0.138μg/gwetweight (wet wt.); the DBP mean levels varied from 0.025±0.018 to 0.174±0.091μg/gwetwt. Highest levels of concentration for DEHP and DBP were found in bread with mean values of 0.307±0.138μg/gwetwt. and 0.174±0.091μg/gwetwt. for DEHP and DBP, respectively. The daily intake for DEHP was 3.1±0.9μg/kgbw and 1.5±0.5μg/kgbw for DBP. The mean±sd incidence of DEHP and DBP intake via hospital meals on the respective EFSA TDI was 6±2% (range 4-11%), and 15±5% (range 8-24%), respectively. Even if for hospital patients the major route of exposure may be represented by medical devices, the influence of the diet could have a significant value on TDI. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Mono-(2-ethylhexyl)-phthalate (MEHP) affects ERK-dependent GDNF signalling in mouse stem-progenitor spermatogonia

    International Nuclear Information System (INIS)

    Lucas, Benjamin E.G.; Fields, Christopher; Joshi, Neeraj; Hofmann, Marie-Claude

    2012-01-01

    Highlights: ► MEHP affects SSC proliferation in a dose- and time-dependent manner. ► MEHP does not increase apoptosis, necrosis or the production of ROS in SSCs. ► MEHP reduces the activity of the GDNF/ERK1/2/FOS signalling pathway in SSCs. ► MEHP does not affect the GDNF/SRC/MYCN signalling pathway in SSCs. -- Abstract: Many commercial and household products such as lubricants, cosmetics, plastics, and paint contain phthalates, in particular bis-(2-ethyhexyl)-phthalate (DEHP). As a consequence, phthalates have been found in a number of locations and foods (streambeds, household dust, bottled water and dairy products). Epidemiological and animal studies analysing phthalate exposure in males provide evidence of degradation in sperm quality, associated to an increase in the incidence of genital birth defects and testicular cancers. In the testis, spermatogenesis is maintained throughout life by a small number of spermatogonial stem cells (SSCs) that self-renew or differentiate to produce adequate numbers of spermatozoa. Disruption or alteration of SSC self-renewal induce decreased sperm count and sperm quality, or may potentially lead to testicular cancer. GDNF, or glial cell-line-derived neurotrophic factor, is a growth factor that is essential for the self-renewal of SSCs and continuous spermatogenesis. In the present study, the SSC-derived cell line C18-4 was used as a model for preliminary assessment of the effects of mono-(2-ethylhexyl)-phthalate (MEHP, main metabolite of DEHP) on spermatogonial stem cells. Our data demonstrate that MEHP disrupts one of the known GDNF signalling pathways in these cells. MEHP induced a decrease of C18-4 cell viability in a time- and dose-dependent manner, as well as a disruption of ERK1/2 activation but not of SRC signalling. As a result, we observed a decrease of expression of the transcription factor FOS, which is downstream of the GDNF/ERK1/2 axis in these cells. Taken together, our data suggest that MEHP exposure

  7. Mycelial fungi completely remediate di(2-ethylhexyl)phthalate, the hazardous plasticizer in PVC blood storage bag

    International Nuclear Information System (INIS)

    Pradeep, S.; Benjamin, Sailas

    2012-01-01

    Highlights: ► Three novel phthalate utilizing fungi: A. parasiticus, F. subglutinans and P. funiculosum. ► Fungi utilize DEHP in PVC plastics in situ, in simple mineral salt medium. ► Employing these fungi, a batch process can remediate phthalates in plastics. ► Phthalate-free PVC can be recycled afresh. ► Mineral salt and phthalate remediated into fungal biomass. - Abstract: This pioneering work describes how simply, inexpensively and efficiently novel fungi utilize the alarming plasticizer, di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood storage bags (BB). In order to quantify total DEHP (33.5%, w/w) present in BB, it was extracted using n-hexane and confirmed by GC–MS. Three mycelial fungi, viz., Aspergillus parasiticus, Fusarium subglutinans and Penicillium funiculosum isolated in our laboratory form heavily plastics-contaminated soil – either singly or in consortium – completely consumed intact DEHP physically bound to BB by static submerged growth (28 °C) in simple basal salt medium (BSM). A two-stage cultivation strategy was adopted for the complete removal of DEHP from BB in situ. During the first growth stage, almost 70% DEHP contained in the BB was consumed in 2 weeks, accompanied by increased fungal biomass (∼0.15–0.35 g/g BB; OD ∼7 at 600 nm) and a sharp declining (3.3) of initial pH (7.2). Spent BSM was replaced at this stagnant growth state (low pH), thus in the second stage, remaining DEHP bound to BB utilized completely (over 99%). Furthermore, A. parasiticus and F. subglutinans also grew well on scrapes of PVC water pipes in BSM. F. subglutinans was as efficient independently as consortium in completely utilizing the DEHP bound to BB, and these fungi offer great potentials for the inexpensive and eco-friendly bioremediation of phthalates in medical and allied PVC wastes on a large scale through a batch process in alleviating the plactics waste management issue.

  8. Mycelial fungi completely remediate di(2-ethylhexyl)phthalate, the hazardous plasticizer in PVC blood storage bag

    Energy Technology Data Exchange (ETDEWEB)

    Pradeep, S. [Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala 673 635 (India); Benjamin, Sailas, E-mail: sailasben@yahoo.co.in [Enzyme Technology Laboratory, Biotechnology Division, Department of Botany, University of Calicut, Kerala 673 635 (India)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Three novel phthalate utilizing fungi: A. parasiticus, F. subglutinans and P. funiculosum. Black-Right-Pointing-Pointer Fungi utilize DEHP in PVC plastics in situ, in simple mineral salt medium. Black-Right-Pointing-Pointer Employing these fungi, a batch process can remediate phthalates in plastics. Black-Right-Pointing-Pointer Phthalate-free PVC can be recycled afresh. Black-Right-Pointing-Pointer Mineral salt and phthalate remediated into fungal biomass. - Abstract: This pioneering work describes how simply, inexpensively and efficiently novel fungi utilize the alarming plasticizer, di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood storage bags (BB). In order to quantify total DEHP (33.5%, w/w) present in BB, it was extracted using n-hexane and confirmed by GC-MS. Three mycelial fungi, viz., Aspergillus parasiticus, Fusarium subglutinans and Penicillium funiculosum isolated in our laboratory form heavily plastics-contaminated soil - either singly or in consortium - completely consumed intact DEHP physically bound to BB by static submerged growth (28 Degree-Sign C) in simple basal salt medium (BSM). A two-stage cultivation strategy was adopted for the complete removal of DEHP from BB in situ. During the first growth stage, almost 70% DEHP contained in the BB was consumed in 2 weeks, accompanied by increased fungal biomass ({approx}0.15-0.35 g/g BB; OD {approx}7 at 600 nm) and a sharp declining (3.3) of initial pH (7.2). Spent BSM was replaced at this stagnant growth state (low pH), thus in the second stage, remaining DEHP bound to BB utilized completely (over 99%). Furthermore, A. parasiticus and F. subglutinans also grew well on scrapes of PVC water pipes in BSM. F. subglutinans was as efficient independently as consortium in completely utilizing the DEHP bound to BB, and these fungi offer great potentials for the inexpensive and eco-friendly bioremediation of phthalates in medical and allied PVC wastes on a large

  9. Solvent extraction of rare earths from thiocyanate medium using N,N,N',N'-tetra-2-ethylhexyl diglycolamide

    International Nuclear Information System (INIS)

    Anitha, M.; Kotekar, M.K.; Singh, D.K.; Sharma, J.N.; Singh, H.

    2014-01-01

    TEHDGA (N,N,N',N'-tetra-2-ethylhexyl diglycolamide), a neutral extractant, has been explored for separation of Yttrium from other heavy rare earths (Er) from thiocyanate medium. Presence of 5%(v/v) isodecyl alcohol was found to be optimum to prevent third phase formation. Experimental variables such as TEHDGA concentration (0.05M-0.2M), thiocyanate concentration (0.01M-0.04M), aqueous pH, rare earth concentration (0.25g/L-5g/L), temperature (35℃-65℃), stripping reagents on extraction of rare earths were investigated. The extraction of rare earths increased with increase in TEHDGA concentration and the dependency of distribution ratio of rare earth on TEHDGA concentrations is shown. The slopes were analysed to be approximately 3 for all the rare earths. The effect of thiocyanate concentration on distribution ratio is depicted. Based on slope analysis technique, the extracted species was found to be RE(SCN) 3 .3TEHDGA. The distribution ratio values decreased, may possibly be due to decrease in free extractant concentration in the organic phase, from 8.4 to 0.1 for Y with increase in yttrium concentration in the range of 0.25g/L to 5g/L. The extraction of rare earth decreased with increase in temperature indicating exothermic in nature and the enthalpy change (ΔH) obtained for Y(III) was -14.27KJ/mol. Among stripping reagents studied, oxalic acid was efficient in quantitative stripping of rare earths from TEHDGA. The extraction efficiency for rare earths by TEHDGA increased with increase in atomic number: La< Ce< Pr< Nd< Sm< Y< Eu< Gd< Tb< Dy< Ho< Er< Tm< Lu irrespective of thiocyanate concentration. Separation factors between these metal ions were also evaluated. High separation factor of 6.4 for Er/Y pair at 0.03M thiocyanate has indicated the feasibility of using TEHDGA as extractant to separate Y from Er and other rare earths as an alternative for Aliquat 336-thiocyanate system developed in our laboratory

  10. Disruption of reproductive development in male rat offspring following gestational and lactational exposure to di-(2-ethylhexyl phthalate and genistein

    Directory of Open Access Journals (Sweden)

    Lian-Dong Zhang

    2013-01-01

    Full Text Available Studies of developmental effects of mixtures of endocrine disrupters on the male reproductive system are of great concern. In this study, the reproductive effects of the co-administration of di-2-(ethylhexyl phthalate (DEHP and genistein (GEN during pregnancy and lactation were studied in male rat offspring. Pregnant Sprague-Dawley rats were gavaged from gestation day 3 to postnatal day 21 with vehicle control, DEHP 250 mg/kg body weight (bwyday, GEN 50 mg/kg bwday, GEN 400 mg/kg bwday, and two combinations of the two compounds (DEHP 250 mg/kg bwday + GEN 50 mg/kg bwday, DEHP 250 mg/kg bwday + GEN 400 mg/kg bwday. The outcomes studied were general morphometry (weight, AGD, testicular histology, testosterone levels, and expression at the mRNA level of genes involved in steroidogenesis. Organ coefficient, AGD / body weight1/3 י, serum testosterone concentration and genes involved in steroidogenic pathway expression when exposed to DEHP (250mg/kg bwday, GEN(50mg/kg bwday or GEN(400mg/kg bwday alone were not significantly different from the control group. When exposed to (DEHP 250mg/kg bwday +GEN 50mg/kg bwday together during pregnancy and lactation, serum testosterone concentration, epididymis coefficient and Cypal17a1,Scarb1 m RNA expression significantly decreased compared to the control and GEN(50mg/kg bwday. When exposed to (DEHP 250mg/kg bwday +GEN 400mg/kg bwday together during pregnancy and lactation, AGD / body weight1/3 י, serum testosterone concentration, testis and epididymis coefficient and Star, Cypal17a1 mRNA expression appeared significantly decreased compared to the control and DEHP/GEN single exposure, together with developmental impairment of seminiferous tubules and seminiferous epithelium. Overall, co-administration of DEHP and GEN during gestation and lactation seem to acts in a cumulative manner to induce the most significant alterations in the neonate, especially with GEN at high dose, although the effect of the DEHP

  11. Assessment of Carcinogenicity of di(2-ethylhexyl) phthalate in a short-term assay using Xpa(-/-) and Xpa(-/-)/p53(+/-) mice

    DEFF Research Database (Denmark)

    Mortensen, Alicja; Bertram, Margareta; Aarup, V.

    2002-01-01

    The potential of Xpa(-/-) and Xpa(-/-)/p53(+/-) mice for short-term carcinogenicity assays was evaluated with di(2-ethylhexyl)phthalate (DEHP). Groups of 15 male and female Xpa(-/-) mice, received diets containing 0, 1,500, 3, 000, or 6,000 ppm DEHP, and wild-type (WT) and Xpa(-/-)/p53(+/-) mice 0...... 7). The negative carcinogenic response to DEHP and the positive response to p-cresidine support the expected sensitivity to genotoxic carcinogens in these transgenic models....

  12. Experimental and theoretical studies on the photodegradation of 2-ethylhexyl 4-methoxycinnamate in the presence of reactive oxygen and chlorine species

    OpenAIRE

    Gackowska, Alicja; Przybyłek, Maciej; Studziński, Waldemar; Gaca, Jerzy

    2018-01-01

    2-Ethylhexyl 4-methoxycinnamate (EHMC) is one of the most commonly used sunscreen ingredient. In this study we investigated photodegradation of EHMC in the presence of such common oxidizing and chlorinating systems as H2O2, H2O2/HCl, H2O2/UV, and H2O2/HCl/UV. Reaction products were detected by gas chromatography with a mass spectrometric detector (GC-MS). As a result of experimental studies chloro-substituted 4-methoxycinnamic acid (4-MCA), 4-methoxybenzaldehyde (4-MBA) and 4-methoxyphenol (4...

  13. Effet du nitrate d’ammonium sur le développement et l’activité des enzymes anti-oxydantes du fraisier (Fragaria x ananassa L.) micropropagé

    OpenAIRE

    Philippe Druart; Ahmed Jemmali; Karim Ben Hamed; Ahlem Chakroun; Chadly Abdelli

    2007-01-01

    Effect of ammonium nitrate on the development and anti-oxydant enzymes activity of strawberry (Fragaria x ananassa L.) propagated in vitro. The addition of ammonium nitrate (NH4NO3) at different concentrations (500, 1000 and 1500 mg.l-1) to the in vitro multiplication medium improved significantly the vigor and reversed the leaf chlorosis affecting the strawberry shoots when cultivated on Boxus standard medium, which only contains nitrate as source of nitrogen. The analysis performed with bot...

  14. Kinetic of liquid-liquid extraction for uranyl nitrate and actinides (III) and lanthanides (III) nitrates by amide extractants; Cinetique d`extraction liquide-liquide du nitrate d`uranyle et des nitrates d`actinides (III) et de lanthanides (III) par des extractants a fonction amide

    Energy Technology Data Exchange (ETDEWEB)

    Toulemonde, V [CEA Centre d` Etudes Nucleaires de Saclay, 91 -Gif-sur-Yvette (France); [CEA Centre d` Etudes de la Vallee du Rhone, 30 -Marcoule (France). Dept. d` Exploitation du Retraitement et de Demantelement

    1995-12-20

    The kinetics of liquid-liquid extraction by amide extractants have been investigated for uranyl nitrate (monoamide extractants), actinides (III) and lanthanides (III) nitrates (diamide extractants). The transfer of the metallic species from the aqueous phase to the organic phase was studied using two experimental devices: ARMOLLEX (Argonne Modified Lewis cell for Liquid Liquid Extraction) and RSC (Rotating Stabilized Cell). The main conclusions are: for the extraction of uranyl nitrate by DEHDMBA monoamide, the rate-controlling step is the complexation of the species at the interface of the two liquids. Thus, an absorption-desorption (according to Langmuir theory) reaction mechanism was proposed; for the extraction of actinides (III) and lanthanides (III) nitrates in nitric acid media by DMDBTDMA diamide, the kinetic is also limited by interfacial reactions. The behavior of Americium and Europium is very similar as fare as their reaction kinetics are concerned. (author). 89 refs.

  15. The Emulsion Polymerization of Each of Vinyl Acetate and Butyl Acrylate Monomers Using bis (2-ethylhexyl) Maleate for Improving the Physicomechanical Properties of Paints and Adhesive Films

    International Nuclear Information System (INIS)

    Shaffei, K.A.; Moustafa, A.B.; Hamed, A.I.

    2009-01-01

    Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of poly butyl acrylate were achieved by using bis (2-ethylhexyl) maleate (BEHM). The emulsion polymerization kinetics of vinyl acetate and butyl acrylate in presence of BEHM was studied. The order of the polymerization reaction with respect to the BEHM in presence of each of vinyl acetate and butyl acrylate was studied. The physicomechanical properties of the polyvinyl acetate films and vinyl acetate-butyl acrylate copolymer films were studied in presence of BEHM and the obtained results were matched with those prepared in the presence of pluronic F 108 and showed superior values. The obtained mean average molecular weights were found to be smaller in presence of BEHM assuring the presence of chain transfer reaction.

  16. Studies on ion transport of Eu (III) and Gd (III) through supported liquid membranes containing Di-(2-ethylhexyl) phosphate, as a carrier

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, L.; Bolarin, A.M.; Sanchez, F.; Patino, F.; Rivera, I.; Salinas, E. [Area de Investigaciones en Materiales y Metalurgia, Universidad Autonoma del Estado de Hidalgo, Carretera Pachuca-Tulancingo Km. 4.5, 42072 Pachuca, Hidalgo (Mexico)]. e-mail: hcruz@uaeh.reduaeh.mx

    2007-07-01

    In this work, permeation of Eu (III) and Gd (III) between aqueous oxide solutions through supported membrane containing di-(2-ethylhexyl) phosphate as a carrier and kerosene has been studied. Mass transfer of these cations has been determined in terms of permeability coefficients (P) by measurement of metal concentrations in strip solution. The permeability coefficient increases with increase in pH acidity of feed solution ranged from pH 0.5 to 2.5 while that of strip solution was kept constant at 0.1 mol L{sup -1} HNO{sub 3}. Thus, the results obtained show that it is possible to get up to 93% of percentage of extraction. (Author)

  17. Studies on ion transport of Eu (III) and Gd (III) through supported liquid membranes containing Di-(2-ethylhexyl) phosphate, as a carrier

    International Nuclear Information System (INIS)

    Hernandez, L.; Bolarin, A.M.; Sanchez, F.; Patino, F.; Rivera, I.; Salinas, E.

    2007-01-01

    In this work, permeation of Eu (III) and Gd (III) between aqueous oxide solutions through supported membrane containing di-(2-ethylhexyl) phosphate as a carrier and kerosene has been studied. Mass transfer of these cations has been determined in terms of permeability coefficients (P) by measurement of metal concentrations in strip solution. The permeability coefficient increases with increase in pH acidity of feed solution ranged from pH 0.5 to 2.5 while that of strip solution was kept constant at 0.1 mol L -1 HNO 3 . Thus, the results obtained show that it is possible to get up to 93% of percentage of extraction. (Author)

  18. The Emulsion Polymerization of Each of Vinyl Acetate and Butyl Acrylate Monomers Using bis (2-ethylhexyl Maleate for Improving the Physicomechanical Properties of Paints and Adhesive Films

    Directory of Open Access Journals (Sweden)

    K. A. Shaffei

    2009-01-01

    Full Text Available Improving the water sensitivity of polyvinyl acetate PVAc films as well as pressure sensitivity, adhesion and washability of polybutyl acrylate were achieved by using bis (2-ethylhexyl maleate (BEHM. The emulsion polymerization kinetics of vinyl acetate and butyl acrylate in presence of BEHM was studied. The order of the polymerization reaction with respect to the BEHM in presence of each of vinyl acetate and butyl acrylate was studied. The physicomechanical properties of the polyvinyl acetate films and vinyl acetate-butyl acrylate copolymer films were studied in presence of BEHM and the obtained results were matched with those prepared in the presence of pluronic F 108 and showed superior values. The obtained mean average molecular weights were found to be smaller in presence of BEHM assuring the presence of chain transfer reaction.

  19. Bis(2-ethylhexyl)-N,N-diethylcarbamoylmethyl phosphonate as a synergist in the extraction of trivalent lanthanides by 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5

    International Nuclear Information System (INIS)

    Luxmi Varma, R.; Sujatha, S.; Reddy, M.L.P.; Prasada Rao, T.; Iyer, C.S.P.; Damodaran, A.D.

    1996-01-01

    Synergism in the extraction of trivalent lanthanides such as Nd. Eu and Lu has been investigated using mixtures of 1-phenyl-3-methyl-4-trifluoroacetyl-pyrazolone-5 (HPMTFP) and bis(2-ethylhexyl)-N,N-diethylcarbamoylmethyl phosphonate (CMP) in chloroform. Lanthanides are found to be extracted from 0.01 mol/dm 3 chloroacetate medium with HPMTFP as Ln(PMTFP) 3 or Ln(PMTFP) 3 . CMP in the absence or presence of CMP, respectively. The equilibrium constants of these synergistic species do not increase monotonically with atomic number but have a maximum at Eu. The addition of a synergist, CMP to the metal chelate system not only enhances the extraction efficiency but also improves the selectivities among these trivalent lanthanides. The IR results indicate that CMP acts as a bidentate ligand in these mixed-ligand systems. (orig.)

  20. Long-term effects of maternal exposure to Di (2-ethylhexyl Phthalate on sperm and testicular parameters in Wistar rats offspring

    Directory of Open Access Journals (Sweden)

    Ahmad Ali Moazedi

    2012-01-01

    Full Text Available Background: Phthalate esters have been shown to cause reproductive toxicity in both developing and adult animals. Objective: This study was designed to assess long-term effects of maternal exposure to Di (2-ethylhexyl Phthalate (DEHP on reproductive ability of both neonatal and adult male offspring.Materials and Methods: 60 female rats randomly divided in four equal groups; vehicle control and three treatment groups that received 10, 100 and 500 mg/kg/day DEHP via gavage during gestation and lactation. At different ages after birth, the volumes of testes were measured by Cavellieri method, testes weights recorded and epididymal sperm samples were assessed for number and gross morphology of spermatozoa. Following tissue processing, seminiferous tubules diameter and germinal epithelium height evaluated with morphometric techniques.Results: Mean testis weight decreased significantly (p<0.05 in 500 mg/kg/day dose group from 28 to 150 days after birth. Significant decreases were seen in total volumes of testis in 100 (p<0.05 and 500 (p<0.01 mg/kg/day doses groups until 150 days after birth. Seminiferous tubules diameter and germinal epithelium height decreased significantly in 100 (p<0.05 and 500 (p<0.01 mg/kg/day doses groups during postnatal development. Also, mean sperm density in 100 mg/kg/day (p<0.05 and 500 mg/kg/day (p<0.01 doses groups and percent of morphologically normal sperm in highest dose group (p<0.05 decreased significantly until 150 days after birth. Conclusion: Present study showed that maternal exposure to Di (2-ethylhexyl Phthalate during gestation and lactation caused to permanent and dose-related reductions of sperm and testicular parameters in rats offspring

  1. In vitro evaluation of di(2-ethylhexyl)terephthalate-plasticized polyvinyl chloride blood bags for red blood cell storage in AS-1 and PAGGSM additive solutions.

    Science.gov (United States)

    Graminske, Sharon; Puca, Kathleen; Schmidt, Anna; Brooks, Scott; Boerner, Amanda; Heldke, Sybil; de Arruda Indig, Monika; Brucks, Mark; Kossor, David

    2018-05-01

    Di(2-ethylhexyl)phthalate (DEHP) makes polyvinyl chloride flexible for use in blood bags and stabilizes the red blood cell (RBC) membrane preventing excessive hemolysis. DEHP migrates into the blood product and rodent studies have suggested that DEHP exposure may be associated with adverse health effects albeit at high dosages. Although structurally and functionally similar to DEHP, di(2-ethylhexyl)terephthalate (DEHT; or Eastman 168 SG [Eastman Chemical Company]) is metabolically distinct with a comprehensive and benign toxicology profile. This study evaluated RBC stability in DEHT-plasticized bags with AS-1 and PAGGSM compared to conventional DEHP-plasticized bags with AS-1. Thirty-six whole blood units were collected into CPD solution, leukoreduced, centrifuged, and divided into RBCs and plasma. To limit donor-related variability, three ABO-identical RBCs were mixed together and then divided equally and stored among the three different plasticizer and additive solution combinations. RBCs from 12 trios were analyzed for a standard panel of in vitro variables on Day 0 and after storage. No individual bag on Day 42 exceeded the US 1.0% hemolysis criteria. While hemolysis during storage was higher in the DEHT bags, the PAGGSM RBCs were close to the control RBCs (0.38% vs. 0.32%, respectively). ATP retention was higher than 70% and potassium levels were similar regardless of plasticizer. Additional RBC variables exhibited some significant differences but were not viewed as clinically important. DEHT/PAGGSM provides similar hemolysis protection to that of DEHP/AS-1. Although hemolysis values with DEHT and AS-1 are higher than that of DEHP, DEHT is a potential DEHP alternative. © 2018 AABB.

  2. Differential nitrate accumulation, nitrate reduction, nitrate reductase ...

    African Journals Online (AJOL)

    However, the effects of potassium nitrate were higher than sodium nitrate, which was due to the positive effects of potassium on the enzyme activity, sugars transport, water and nutrient transport, protein synthesis and carbohydrate metabolism. In conclusion, potassium nitrate has better effect on the nitrate assimilatory ...

  3. Di-(2-ethylhexyl phthalate metabolites in urine show age-related changes and associations with adiposity and parameters of insulin sensitivity in childhood.

    Directory of Open Access Journals (Sweden)

    Arianna Smerieri

    Full Text Available Phthalates might be implicated with obesity and insulin sensitivity. We evaluated the levels of primary and secondary metabolites of Di-(2-ethylhexyl phthalate (DEHP in urine in obese and normal-weight subjects both before and during puberty, and investigated their relationships with auxological parameters and indexes of insulin sensitivity.DEHP metabolites (MEHP, 6-OH-MEHP, 5-oxo-MEHP, 5-OH-MEHP, and 5-CX-MEHP, were measured in urine by RP-HPLC-ESI-MS. Traditional statistical analysis and a data mining analysis using the Auto-CM analysis were able to offer an insight into the complex biological connections between the studied variables.The data showed changes in DEHP metabolites in urine related with obesity, puberty, and presence of insulin resistance. Changes in urine metabolites were related with age, height and weight, waist circumference and waist to height ratio, thus to fat distribution. In addition, clear relationships in both obese and normal-weight subjects were detected among MEHP, its products of oxidation and measurements of insulin sensitivity.It remains to be elucidated whether exposure to phthalates per se is actually the risk factor or if the ability of the body to metabolize phthalates is actually the key point. Further studies that span from conception to elderly subjects besides further understanding of DEHP metabolism are warranted to clarify these aspects.

  4. Studies on the solvent extraction behaviour of Pu(IV) from nitric acid, nitric-perchloric acid and hydrochloric acids, by di,2-ethylhexyl phosphoric acid (HDEHP)

    International Nuclear Information System (INIS)

    Phal, D.G.; Kannan, S.K.; Ramakrishna, V.V.

    1994-01-01

    Extraction of plutonium (IV) from aqueous nitric acid, nitric-perchloric acid and hydrochloric acids by di,2-ethylhexyl phosphoric acid, the dimeric form of which is represented as H 2 Y 2 , in different diluents (dodecane, toluene and chloroform) was investigated. The composition of the extracted Pu(IV) species were found to be Pu(NO 3 ) 2 (HY) 2 , Pu(NO 3 )(ClO 4 )(HY 2 ) 2 , PuClY(HY 2 ) 2 and PuCl 2 (HY 2 ) 2 from nitric, nitric-perchloric and hydrochloric acids respectively, the last one being pre-dominant at high aqueous acidities (i.e. 5M HCl). Synergic enhancement in the extraction of Pu(IV) from different aqueous media, by the addition of thenoyltrifluoroacetone (HTTA) to HDEHP was also investigated and was attributed to the formation and extraction of the species PuX(TTA)(HY 2 ) 2 , and Pu(TTA) 2 (HY 2 ) 2 where X=Cl - or NO 3 - . The addition of the neutral extractant TOPO to H 2 Y 2 also resulted in synergism. The possible equilibria in these systems were inferred and the corresponding equilibrium constants determined. (author). 24 refs., 10 figs., 10 tabs

  5. An investigation of red blood cell concentrate quality during storage in paediatric-sized polyvinylchloride bags plasticized with alternatives to di-2-ethylhexyl phthalate (DEHP).

    Science.gov (United States)

    Serrano, K; Levin, E; Chen, D; Hansen, A; Turner, T R; Kurach, J; Reidel, A; Boecker, W F; Acker, J P; Devine, D V

    2016-04-01

    Di-2-ethylhexyl phthalate (DEHP) is a blood bag plasticizer. It is also a toxin, raising concerns for vulnerable populations, for example, neonates and infants. Here, the in vitro quality of red cell concentrates (RCC) stored in paediatric bags formulated with alternative plasticizers to DEHP was compared. RCC were pooled and split into polyvinylchloride (PVC)/DEHP, PVC/1,2-cyclohexanedicarboxylic acid diisononyl ester (DINCH) or PVC/butyryl trihexyl citrate (BTHC) bags. Quality was assessed on storage days 5, 21, 35 and 43. Metabolism differed among the bags: pCO2 levels were lowest and pO2 were highest in BTHC bags. Glucose consumption and lactate production suggested higher metabolic rates in BTHC bags. ATP levels were best maintained in DINCH bags (day 43 mean level: 2·86 ± 0·29 μmol/g Hb). RCC in BTHC bags had the greatest potassium release (54·6 ± 3·0 mm on day 43). From day 21, haemolysis was higher in BTHC bags (P bags showed more microparticle formation than RCC in DEHP or DINCH bags. The results suggest that the BTHC formulation used was detrimental to RBC quality. DINCH bags could be a viable alternative to DEHP: they outperformed DEHP bags energetically, with better maintenance of ATP levels. © 2015 International Society of Blood Transfusion.

  6. Increased urinary 8-hydroxy-2'-deoxyguanosine levels in workers exposed to di-(2-ethylhexyl) phthalate in a waste plastic recycling site in China.

    Science.gov (United States)

    Wang, Qian; Wang, Li; Chen, Xi; Rao, Kai Min; Lu, Shao You; Ma, Sheng Tao; Jiang, Pu; Zheng, Dan; Xu, Shun Qing; Zheng, Hong Yan; Wang, Jian Shu; Yu, Zhi Qiang; Zhang, Rong; Tao, Yong; Yuan, Jing

    2011-07-01

    Di-(2-ethylhexyl) phthalate (DEHP) is a common plasticizer used in industrial and diverse consumer products. Animal studies indicate DEHP caused developmental, reproductive, and hepatic toxicities. However, human studies of the potential effects of DEHP are limited. The exposed site with a history of over 20 years of waste plastic recycling was located in Hunan Province, China. The reference site without known DEHP pollution source was about 50 km far away from the exposed site. In this study, 181 workers working in plastic waste recycling and 160 gender-age matched farmers were recruited. DEHP concentrations in water and cultivated soil samples, serum thyroid-stimulating hormone, malondialdehyde (MDA), superoxide dismutase (SOD), urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG), and micronuclei frequency in human capillary blood lymphocytes were analyzed. Mean levels of DEHP were greater in environment at the recycling site than at reference site (industry wastewater for the exposed: 42.43 μg/l; well water: 14.20 vs. 0.79 μg/l, pond water: 135.68 vs. 0.37 μg/l, cultivated soil: 13.07 vs. 0.81 mg/kg, p history of working in waste plastic recycling was an independent risk factor for the increased urinary 8-OHdG levels in the male workers (p < 0.01). The occupational DEHP exposure might contribute to oxidative deoxyribonucleic acid damage in the male workers.

  7. Maternal di-(2-ethylhexyl) phthalate exposure during pregnancy causes fetal growth restriction in a stage-specific but gender-independent manner.

    Science.gov (United States)

    Shen, Ru; Zhao, Ling-Li; Yu, Zhen; Zhang, Cheng; Chen, Yuan-Hua; Wang, Hua; Zhang, Zhi-Hui; Xu, De-Xiang

    2017-01-01

    Di (2-ethylhexyl) phthalate (DEHP) is male developmental toxicant that impairs testis development with reduced anogenital distance. The present study aimed to investigate whether maternal DEHP exposure during pregnancy causes intrauterine growth restriction (IUGR) in a gender-specific manner and to identify the critical window of DEHP-induced fetal IUGR. Pregnant mice were administered with DEHP (0, 50 or 200mg/kg) by gavage. Fetal IUGR was observed not only in males but also in females when litters were exposed to DEHP on gestational day (GD)0-GD17. Interestingly, fetal weight and crown-rump length were reduced, markedly in dams with DEHP on GD13-GD17, slightly in dams with on GD7-GD12, but not in dams with on GD0-GD6. Further analysis showed that maternal DEHP exposure on GD7-GD12 inhibited cell proliferation, lowered placental weight, and reduced blood sinusoid area in placental labyrinth layer. These results suggest that maternal DEHP exposure induces IUGR in a stage-specific but gender-independent manner. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Inhibition of di(2-ethylhexyl) phthalate (DEHP)-induced endocrine disruption by co-treatment of vitamins C and E and their mechanism of action.

    Science.gov (United States)

    Choi, Seul Min; Lim, Duck Soo; Kim, Min Kook; Yoon, Sungpil; Kacew, Sam; Kim, Hyung Sik; Lee, Byung-Mu

    2018-05-29

    The endocrine disrupting actions of di(2-ethylhexyl) phthalate (DEHP) on testicular functions are postulated to involve excess free radical generation. Thus the aim of this study was to examine the ability of antioxidant vitamins C and E to prevent DEHP-induced testicular disruption in male Sprague-Dawley (SD) rats. SD male rats were administered DEHP alone or DEHP with vitamin C and/or vitamin E for 30 days. DEHP alone increased the levels of testosterone (T) and reduced estradiol (E 2 ) concentrations. Supplementation with antioxidant vitamins diminished or restored serum T levels noted in DEHP-treated rats to control values. In contrast vitamins C and E increased E 2 levels to control in rats administered DEHP. Antioxidants significantly improved the decreased testicular levels of reduced glutathione and activity of superoxide dismutase compared to DEHP-treatment alone. Co-treatment of vitamins C and E also markedly improved the reduced epididymal sperm head counts and elevated levels of malondialdehyde (MDA) or 8-hydroxydeoxyguanosine (8-OHdG) induced by DEHP treatment. These results support the concept that the adverse actions of DEHP may be related to increased free radical generation while co-treatment with vitamins C and E significantly blocked the actions of DEHP on male testicular functions.

  9. Extractive separation of Al(III) and Ni(II) by Di-2-Ethylhexyl phosphoric acid-kerosene system from aqueous fluoride medium

    International Nuclear Information System (INIS)

    Islam, M.F.; Begum, D.A.; Rahman, M.; Rahman, M.S.

    2009-01-01

    In the study of the extractive separation of Al(III) and Ni(II) by di-2-ethylhexyl phosphoric acid D2EHPA-kerosene from aqueous fluoride medium, about 94% Al(III) and 2% Ni(II) were extracted with 0.3 M D2EHPA (pH 2.1 and temperature 30+-1 degree C). Extraction of Ni(II) decreased with increasing extractant concentration. D2EHPA-kerosene-fluoride system showed better extraction of Al(III) with higher extractant concentration and aqueous pH and vice versa for the extraction of Ni(II). The maximum separation factor (beta 1380) was obtained for Al(III) at 20 degree C and decreased to (beta 732) at 60 degree C. The separation of Al(III) from Ni(II) was favoured at normal temperature. Extraction followed the order Al(III), Ni(II). About 99% stripping of Al(III) was attained from the loaded 0.20 M D2EHPA. Much faster extraction of Al(III) compared to Ni(II) and preferential loading were shown by D2EHPA-kerosene in the presence of fluoride ion in the aqueous phase. Separation of Al(III) was the most outstanding from Ni-Al-F-complex solution. (author)

  10. Solution processed white light photodetector based N, N′-di (2-ethylhexyl)-3,4,9,10-perylene diimide thin film phototransistor

    Energy Technology Data Exchange (ETDEWEB)

    Tozlu, Cem, E-mail: tozlu.cem@gmail.com [Department of Energy System Engineering, Faculty of Engineering, Karamanoğlu Mehmetbey University, 70100 Karaman (Turkey); Kus, Mahmut [Department of Chemical Engineering, Selcuk University, Konya 42075 (Turkey); Advanced Technology Research and Application Center, Selcuk University, Konya 42075 (Turkey); Can, Mustafa [Department of Engineering Sciences, Faculty of Engineering, Izmir Katip Celebi University, Cigli, 35620 Izmir (Turkey); Ersöz, Mustafa [Advanced Technology Research and Application Center, Selcuk University, Konya 42075 (Turkey); Department of Chemistry, Selcuk University, Konya 42075 (Turkey)

    2014-10-31

    In this study, a solution-processed n-type photo-sensing organic thin film transistor was investigated using polymeric dielectric under different white light illuminations. N, N′-di (2-ethylhexyl)-3,4,9,10-perylene diimide and divinyl tetramethyl disiloxane-bis (benzo-cyclobutene) were used as a soluble active organic semiconductor and as a dielectric material, respectively. Stable amplification was observed in the visible region without gate bias by the device. The electrical characterization results showed that an n-type phototransistor with a saturated electron mobility of 0.6 × 10{sup −3} cm{sup 2}/V·s and a threshold voltage of 1.8 V was obtained. The charge carrier density of the channel of the device exhibited photo-induced behaviors that strongly affected the electrical properties of the transistor. The photosensitivity and photoresponsivity values of the device were 63.82 and 24 mA/W, respectively. These findings indicate that perylene diimide is a promising material for use on organic based phototransistors. - Highlights: • A solution processed n-type organic phototransistor was fabricated. • The geometry of device allows to be used double sided photo-sensor to detect light. • The accumulation of charge carrier is effected strongly by illumination intensity. • The current amplification was observed clearly under illumination without gate bias.

  11. Effect of environmental conditions on the migration of DI (2-Ethylhexyl) Phthalate from PET bottles into yogurt drinks: Influence of time, temperature and food simulant

    International Nuclear Information System (INIS)

    Farhoodi, M.; Emam-Djomeh, Z.; Ehsani, Mohammad Reza; Oromiehie, A.

    2008-01-01

    Polyethylene terephthalate (PET) is one of the materials that are widely used for packaging of beverages and edible oils. In this study, the migration of di (2-ethylhexyl) phthalate (DEHP) from PET bottles into the Iranian yogurt drink was investigated. According to European Commission regulations, acetic acid (3% w/v) was chosen as stimulant. The acetic acid samples were stored at 4C, 25C and 45Cfor four months and analyzed periodically by gas chromatography. Differential Scanning Calorimetry (DSC) was used to investigate if contact with the food stimulant could affect the PET material. It was concluded that the storage temperature had a large effect on the migration of DEHP. Also, increasing storage time resulted in higher concentrations of migrating DEHP. The concentrations of migrating substance did not exceed its specific migration limit (Economic European Community (EEC) regulations). Determination of glass transition (Tg) and crystallinity percent of PET bottles using DSC method showed that the variations in the amount of migration at different storage condition did not induce any change in the PET material in contact with 3% acetic acid. (author)

  12. Optical and electron paramagnetic resonance studies of the excited triplet states of UV-B absorbers: 2-ethylhexyl salicylate and homomenthyl salicylate.

    Science.gov (United States)

    Sugiyama, Kazuto; Tsuchiya, Takumi; Kikuchi, Azusa; Yagi, Mikio

    2015-09-26

    The energy levels and lifetimes of the lowest excited triplet (T1) states of UV-B absorbers, 2-ethylhexyl salicylate (EHS) and homomenthyl salicylate (HMS), and their deprotonated anions (EHS(-) and HMS(-)) were determined through measurements of phosphorescence and electron paramagnetic resonance (EPR) spectra in rigid solutions at 77 K. The observed T1 energies of EHS and HMS are higher than those of butylmethoxydibenzoylmethane, the most widely used UV-A absorber, and octyl methoxycinnamate, the most widely used UV-B absorber. The T1 states of EHS, HMS, EHS(-) and HMS(-) were assigned to almost pure (3)ππ* state from the observed T1 lifetimes and zero-field splitting parameters. EHS and HMS with an intramolecular hydrogen bond show a photoinduced phosphorescence enhancement in ethanol at 77 K. The EPR signals of the T1 states of EHS and HMS also increase in intensity with UV-irradiation time (photoinduced EPR enhancement). The T1 lifetimes of EHS and HMS at room temperature were determined through triplet-triplet absorption measurements in ethanol. The quantum yields of singlet oxygen production by EHS and HMS were determined by using time-resolved near-IR phosphorescence.

  13. Facilitated transport of Cr(III) through activated composite membrane containing di-(2-ethylhexyl)phosphoric acid (DEHPA) as carrier agent

    International Nuclear Information System (INIS)

    Arslan, Gulsin; Tor, Ali; Cengeloglu, Yunus; Ersoz, Mustafa

    2009-01-01

    The facilitated transport of chromium(III) through activated composite membrane (ACM) containing di-(2-ethylhexyl) phosphoric acid (DEHPA) was investigated. DEHPA was immobilised by interfacial polymerisation on polysulfone layer which was deposited on non-woven fabric by using spin coater. Then, ACM was characterised by using scanning electron microscopy (SEM), contact angle measurements and atomic force microscopy (AFM). Initially, batch experiments of liquid-liquid distribution of Cr(III) and the extractant (DEHPA) were carried out to determine the appropriate pH of the feed phase and the results showed that maximum extraction of Cr(III) was achieved at a pH of 4. It was also found that Cr(III) and DEHPA reacted in 1/1 molar ratio. The effects of Cr(III) (in feed phase), HCl (in stripping phase) and DEHPA (in ACM) concentrations were investigated. DEHPA concentration varies from 0.1 to 1.0 M and it was determined that the transport of Cr(III) increased with the carrier concentration up to 0.8 M. It was also observed that the transport of Cr(III) through the ACM tended to increase with Cr(III) and HCl concentrations. The stability of ACM was also confirmed with replicate experiments.

  14. Facilitated transport of Cr(III) through activated composite membrane containing di-(2-ethylhexyl)phosphoric acid (DEHPA) as carrier agent

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Gulsin [Department of Chemistry, Selcuk University, 42031, Campus, Konya (Turkey); Tor, Ali, E-mail: ator@selcuk.edu.tr [Department of Environmental Engineering, Selcuk University, 42031 Campus, Konya (Turkey); Cengeloglu, Yunus; Ersoz, Mustafa [Department of Chemistry, Selcuk University, 42031, Campus, Konya (Turkey)

    2009-06-15

    The facilitated transport of chromium(III) through activated composite membrane (ACM) containing di-(2-ethylhexyl) phosphoric acid (DEHPA) was investigated. DEHPA was immobilised by interfacial polymerisation on polysulfone layer which was deposited on non-woven fabric by using spin coater. Then, ACM was characterised by using scanning electron microscopy (SEM), contact angle measurements and atomic force microscopy (AFM). Initially, batch experiments of liquid-liquid distribution of Cr(III) and the extractant (DEHPA) were carried out to determine the appropriate pH of the feed phase and the results showed that maximum extraction of Cr(III) was achieved at a pH of 4. It was also found that Cr(III) and DEHPA reacted in 1/1 molar ratio. The effects of Cr(III) (in feed phase), HCl (in stripping phase) and DEHPA (in ACM) concentrations were investigated. DEHPA concentration varies from 0.1 to 1.0 M and it was determined that the transport of Cr(III) increased with the carrier concentration up to 0.8 M. It was also observed that the transport of Cr(III) through the ACM tended to increase with Cr(III) and HCl concentrations. The stability of ACM was also confirmed with replicate experiments.

  15. Effective remediation of phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate in farm effluent using Guar gum--A plant based biopolymer.

    Science.gov (United States)

    Kee, Yang Ling; Mukherjee, Sumona; Pariatamby, Agamuthu

    2015-10-01

    This study was carried out to evaluate the efficiency of Guar gum in removing Persistent Organic Pollutants (POPs), viz. phenol,2,4-bis(1,1-dimethylethyl) and bis(2-ethylhexyl) phthalate (DEHP), from farm effluent. The removal efficiency was compared with alum. The results indicated that 4.0 mg L(-1) of Guar gum at pH 7 could remove 99.70% and 99.99% of phenol,2,4-bis(1,1-dimethylethyl) and DEHP, respectively. Box Behnken design was used for optimization of the operating parameters for optimal POPs removal. Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy studies were conducted on the flocs. SEM micrographs showed numerous void spaces in the flocs produced by Guar gum as opposed to those produced by alum. This indicated why Guar gum was more effective in capturing and removal of suspended particles and POPs as compared to alum. FTIR spectra indicated a shift in the bonding of functional groups in the flocs produced by Guar gum as compared to raw Guar gum powder signifying chemical attachment of the organics present in the effluent to the coagulant resulting in their removal. Guar gum is highly recommended as a substitute to chemical coagulant in treating POPs due to its non-toxic and biodegradable characteristics. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Reduced hippocampal dendritic spine density and BDNF expression following acute postnatal exposure to di(2-ethylhexyl phthalate in male Long Evans rats.

    Directory of Open Access Journals (Sweden)

    Catherine A Smith

    Full Text Available Early developmental exposure to di(2-ethylhexyl phthalate (DEHP has been linked to a variety of neurodevelopmental changes, particularly in rodents. The primary goal of this work was to establish whether acute postnatal exposure to a low dose of DEHP would alter hippocampal dendritic morphology and BDNF and caspase-3 mRNA expression in male and female Long Evans rats. Treatment with DEHP in male rats led to a reduction in spine density on basal and apical dendrites of neurons in the CA3 dorsal hippocampal region compared to vehicle-treated male controls. Dorsal hippocampal BDNF mRNA expression was also down-regulated in male rats exposed to DEHP. No differences in hippocampal spine density or BDNF mRNA expression were observed in female rats treated with DEHP compared to controls. DEHP treatment did not affect hippocampal caspase-3 mRNA expression in male or female rats. These results suggest a gender-specific vulnerability to early developmental DEHP exposure in male rats whereby postnatal DEHP exposure may interfere with normal synaptogenesis and connectivity in the hippocampus. Decreased expression of BDNF mRNA may represent a molecular mechanism underlying the reduction in dendritic spine density observed in hippocampal CA3 neurons. These findings provide initial evidence for a link between developmental exposure to DEHP, reduced levels of BDNF and hippocampal atrophy in male rats.

  17. Interaction of melamine and di-(2-ethylhexyl) phthalate exposure on markers of early renal damage in children: The 2011 Taiwan food scandal.

    Science.gov (United States)

    Wu, Chia-Fang; Hsiung, Chao A; Tsai, Hui-Ju; Tsai, Yi-Chun; Hsieh, Hui-Min; Chen, Bai-Hsiun; Wu, Ming-Tsang

    2018-04-01

    Melamine and phthalate, mainly di-(2-ethylhexyl) phthalate (DEHP), are ubiquitously present in the general environment. We investigated whether urine melamine levels can modify the relationship between DEHP exposure and markers of early renal damage in children. A nationwide health survey for Children aged ≤12 years possibly exposed to phthalates were enrolled between August 2012 and January 2013. They were administered questionnaires to collect details regarding past DEHP exposure to phthalate-tainted foodstuffs. Urine samples were measured melamine levels, phthalate metabolites and biomarkers of renal damage, including urine microalbumin/creatinine ratio (ACR), N-acetyl-beta-d-glucosaminidase (NAG), and β2-microglobulin. The study included 224 children who had a median urine melamine level (μg/mmol creatinine) of 1.61 ranging 0.18-47.42. Positive correlations were found between urine melamine levels and urine ACR as well as urine NAG levels (both Spearman correlation coefficients r = 0.24, n = 224, p < .001). The higher the past DEHP exposure or urine melamine levels, the higher the prevalence of microalbuminuria. An interaction effect was also found between urine melamine levels and past DEHP exposure on urine ACR. Melamine levels may further modify the effect of past DEHP exposure on urine ACR in children. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Effect of environmental conditions on the migration of di(2-ethylhexyl)phthalate from pet bottles into yogurt drinks: influence of time, temperature, and food simulant

    International Nuclear Information System (INIS)

    Farhoodi, Mehdi; Djomeh, Zahra Emam; Ehsani, Mohammad Reza; Oromiehie, Abdolrasul

    2008-01-01

    Polyethylene terephthalate (PET) is one of the materials that are widely used for packaging of beverages and edible oils. In this study, the migration of di(2-ethylhexyl)phthalate (DEHP) from PET bottles into the Iranian yogurt drink was investigated. According to European Commission regulations, acetic acid (3% w/v) was chosen as simulant. The acetic acid samples were stored at 4 degree C, 25 degree C, and 45 degree C for four months and analyzed periodically by gas chromatography. Differential Scanning Calorimetry (DSC) was used to investigate if contact with the food simulant could affect the PET material. It was concluded that the storage temperature had a large effect on the migration of DEHP. Also, increasing storage time resulted in higher concentrations of migrating DEHP. The concentrations of migrating substance did not exceed its specific migration limit (Economic European Community (EEC) regulations). Determination of glass transition (Tg) and crystallinity percent of PET bottles using DSC method showed that the variations in the amount of migration at different storage condition did not induce any change in the PET material in contact with 3% acetic acid. (author)

  19. Maternal exposure to di(2-ethylhexyl)phthalate (DEHP) promotes the transgenerational inheritance of adult-onset reproductive dysfunctions through the female germline in mice

    Energy Technology Data Exchange (ETDEWEB)

    Pocar, Paola, E-mail: paola.pocar@unimi.it; Fiandanese, Nadia; Berrini, Anna; Secchi, Camillo; Borromeo, Vitaliano

    2017-05-01

    Endocrine disruptors (EDs) are compounds known to promote transgenerational inheritance of adult-onset disease in subsequent generations after maternal exposure during fetal gonadal development. This study was designed to establish whether gestational and lactational exposure to the plasticizer di(2-ethylhexyl)phthalate (DEHP) at environmental doses promotes transgenerational effects on reproductive health in female offspring, as adults, over three generations in the mouse. Gestating F0 mouse dams were exposed to 0, 0.05, 5 mg/kg/day DEHP in the diet from gestational day 0.5 until the end of lactation. The incidence of adult-onset disease in reproductive function was recorded in F1, F2 and F3 female offspring. In adult F1 females, DEHP exposure induced reproductive adverse effects with: i) altered ovarian follicular dynamics with reduced primordial follicular reserve and a larger growing pre-antral follicle population, suggesting accelerated follicular recruitment; ii) reduced oocyte quality and embryonic developmental competence; iii) dysregulation of the expression profile of a panel of selected ovarian and pre-implantation embryonic genes. F2 and F3 female offspring displayed the same altered reproductive morphological phenotype and gene expression profiles as F1, thus showing transgenerational transmission of reproductive adverse effects along the female lineage. These findings indicate that in mice exposure to DEHP at doses relevant to human exposure during gonadal sex determination significantly perturbs the reproductive indices of female adult offspring and subsequent generations. Evidence of transgenerational transmission has important implications for the reproductive health and fertility of animals and humans, significantly increasing the potential biohazards of this toxicant. - Highlights: • Maternal exposure to DEHP transgenerationally affects female reproductive health. • DEHP reduced ovarian follicular reserve up to the third generation. • DEHP

  20. Maternal exposure to di(2-ethylhexyl)phthalate (DEHP) promotes the transgenerational inheritance of adult-onset reproductive dysfunctions through the female germline in mice

    International Nuclear Information System (INIS)

    Pocar, Paola; Fiandanese, Nadia; Berrini, Anna; Secchi, Camillo; Borromeo, Vitaliano

    2017-01-01

    Endocrine disruptors (EDs) are compounds known to promote transgenerational inheritance of adult-onset disease in subsequent generations after maternal exposure during fetal gonadal development. This study was designed to establish whether gestational and lactational exposure to the plasticizer di(2-ethylhexyl)phthalate (DEHP) at environmental doses promotes transgenerational effects on reproductive health in female offspring, as adults, over three generations in the mouse. Gestating F0 mouse dams were exposed to 0, 0.05, 5 mg/kg/day DEHP in the diet from gestational day 0.5 until the end of lactation. The incidence of adult-onset disease in reproductive function was recorded in F1, F2 and F3 female offspring. In adult F1 females, DEHP exposure induced reproductive adverse effects with: i) altered ovarian follicular dynamics with reduced primordial follicular reserve and a larger growing pre-antral follicle population, suggesting accelerated follicular recruitment; ii) reduced oocyte quality and embryonic developmental competence; iii) dysregulation of the expression profile of a panel of selected ovarian and pre-implantation embryonic genes. F2 and F3 female offspring displayed the same altered reproductive morphological phenotype and gene expression profiles as F1, thus showing transgenerational transmission of reproductive adverse effects along the female lineage. These findings indicate that in mice exposure to DEHP at doses relevant to human exposure during gonadal sex determination significantly perturbs the reproductive indices of female adult offspring and subsequent generations. Evidence of transgenerational transmission has important implications for the reproductive health and fertility of animals and humans, significantly increasing the potential biohazards of this toxicant. - Highlights: • Maternal exposure to DEHP transgenerationally affects female reproductive health. • DEHP reduced ovarian follicular reserve up to the third generation. • DEHP

  1. Influence of temperature on the emission of di-(2-ethylhexyl)phthalate (DEHP) from PVC flooring in the emission cell FLEC.

    Science.gov (United States)

    Clausen, Per Axel; Liu, Zhe; Kofoed-Sørensen, Vivi; Little, John; Wolkoff, Peder

    2012-01-17

    Emissions of di-(2-ethylhexyl) phthalate (DEHP) from one type of polyvinylchloride (PVC) flooring with approximately 13% (w/w) DEHP as plasticizer were measured in the Field and Laboratory Emission Cell (FLEC). The gas-phase concentrations of DEHP versus time were measured at air flow rate of 450 mL·min(-1) and five different temperatures: 23 °C, 35 °C, 47 °C, 55 °C, and 61 °C. The experiments were terminated two weeks to three months after steady-state was reached and the interior surface of the FLECs was rinsed with methanol to determine the surface concentration of DEHP. The most important findings are (1) DEHP steady-state concentrations increased greatly with increasing temperature (0.9 ± 0.1 μg·m(-3), 10 ± 1 μg·m(-3), 38 ± 1 μg·m(-3), 91 ± 4 μg·m(-3), and 198 ± 5 μg·m(-3), respectively), (2) adsorption to the chamber walls decreased greatly with increasing temperature (measured partition coefficient between FLEC air and interior surface are: 640 ± 146 m, 97 ± 20 m, 21 ± 5 m, 11 ± 2 m, and 2 ± 1 m, respectively), (3) gas-phase DEHP concentration in equilibrium with the vinyl flooring surface is close to the vapor pressure of pure DEHP, and (4) with an increase of temperature in a home from 23 to 35 °C, the amount of DEHP in the gas- and particle-phase combined is predicted to increase almost 10-fold. The amount in the gas-phase increases by a factor of 24 with a corresponding decrease in the amount on the airborne particles.

  2. Hepatic peroxisome proliferator-activated receptor α may have an important role in the toxic effects of di(2-ethylhexyl)phthalate on offspring of mice

    International Nuclear Information System (INIS)

    Hayashi, Yumi; Ito, Yuki; Yamagishi, Nozomi; Yanagiba, Yukie; Tamada, Hazuki; Wang, Dong; Ramdhan, Doni Hikmat; Naito, Hisao; Harada, Yukiko; Kamijima, Michihiro; Gonzales, Frank J.; Nakajima, Tamie

    2011-01-01

    Maternal exposure to di(2-ethylhexyl)phthalate (DEHP) is associated with adverse effects on offspring, and the metabolites are agonists of peroxisome proliferator-activated receptor (PPAR) α, which exhibits species differences in expression and function. This study aimed to clarify the mechanism of DEHP-induced adverse effects on offspring in relation to maternal mouse and human PPARα. Male and female Sv/129 wild-type (mPPARα), Pparα-null and humanized PPARα (hPPARα) mice were treated with diets containing 0%, 0.01%, 0.05% (medium) or 0.1% (high) DEHP. After 4 weeks, males and females were mated. Dams were killed on gestational day 18 and postnatal day (PND) 2. High-dose DEHP decreased the number of total and live fetuses, and increased resorptions in mPPARα mice. In hPPARα mice, resorptions were increased above the medium dose, and the number of births was decreased at the high dose. The number of live pups on PND2 was decreased over the medium dose in mPPARα and at the high dose in hPPARα mice. No such findings were observed in Pparα-null mice. High-dose DEHP decreased plasma triglyceride in pregnant mPPARα mice, but not in Pparα-null and hPPARα ones. Above the medium dose in mPPARα mice significantly reduced hepatic microsomal triglyceride transfer protein (MTP) expression. Medium- and/or high-dose DEHP increased the levels of maternal PPARα target genes in mPPARα and hPPARα mice. Taken together, PPARα expression is required for the toxicity of DEHP in fetuses and pups and altered plasma triglyceride levels, through regulation of MTP may be important in mPPARα mice and not in hPPARα mice.

  3. Features of the thermodynamics of trivalent lanthanide/actinide distribution reactions by tri-n-octylphosphine oxide and bis(2-ethylhexyl) phosphoric acid.

    Science.gov (United States)

    Grimes, Travis S; Zalupski, Peter R; Martin, Leigh R

    2014-11-06

    A new methodology has been developed to study the thermochemical features of the biphasic transfer reactions of trisnitrato complexes of lanthanides and americium by a monofunctional solvating ligand (tri-n-octylphosphine oxide, TOPO). Stability constants for successive nitrato complexes (M(NO3)x(3-x)(aq) where M is Eu(3+), Am(3+), or Cm(3+)) were determined to assist in the calculation of the extraction constant, K(ex), for the metal ions under study. Enthalpies of extraction (ΔH(extr)) for the lanthanide series (excluding Pm(3+)) and Am(3+) by TOPO have been measured using isothermal titration calorimetry. The observed ΔH(extr) were found to be constant at ~29 kJ mol(-1) across the series from La(3+) to Er(3+), with a slight decrease observed from Tm(3+) to Lu(3+). These heats were found to be consistent with enthalpies determined using van't Hoff analysis of temperature dependent extraction studies. A complete set of thermodynamic parameters (ΔG, ΔH, ΔS) was calculated for Eu(NO3)3, Am(NO3)3, and Cm(NO3)3 extraction by TOPO and Am(3+) and Cm(3+) extraction by bis(2-ethylhexyl) phosphoric acid (HDEHP). A discussion comparing the energetics of these systems is offered. The measured biphasic extraction heats for the transplutonium elements, ΔH(extr), presented in these studies are the first ever direct measurements offered using two-phase calorimetric techniques.

  4. Study on the influence of temperature, storage time and packaging type on di-n-butylphthalate and di(2-ethylhexyl)phthalate release into packed meals.

    Science.gov (United States)

    Cirillo, Teresa; Fasano, Evelina; Esposito, Francesco; Del Prete, Ernesto; Cocchieri, Renata Amodio

    2013-01-01

    Ready-to-eat meals packed in polyethylene terephthalate (PET) and aluminium dishes, supplied to patients in two hospitals in the Campania region (Italy), were studied to evaluate the probable migration of di-n-butylphthalate (DBP) and di(2-ethylhexyl)phthalate (DEHP) from the packaging into the food. The influence of temperature, storage time and type of package on the migration process was considered, analysing the meals according to three time ranges, before the packaging (T(0)) and after 60 min (T(1)) and 120 min (T(2)) from packaging during the storage in thermostatic delivery carts. At T(0) in the meals sampled before packaging in PET dishes, mean levels of DBP and DEHP were 0.023 ± 0.002 µg/g and 0.069 ± 0.041 µg/g, respectively; the DBP level increased 230% and that of DEHP increased 208% by time T(0) versus T(2). In the meals sampled before packaging (T(0)) in aluminium dishes, the mean levels of DBP and DEHP were 0.030 ± 0.001 µg/g and 0.057 ± 0.015 µg/g, respectively. The significant increase in contaminant levels over storage times for meals packed in PET dishes demonstrates that from packages made of plastic materials the migration of phthalic acid esters into foods is possible. In meals packed in PET dishes, the highest DBP and DEHP increases were observed in the T(0) to T(1) range, which represented the time interval over which meals were kept hot, and mainly in the first ones, where the highest temperatures have been recorded.

  5. Characterization and evaluation of poly(epsilon-caprolactone) nanoparticles containing 2-ethylhexyl-p-methoxycinnamate, octocrylene, and benzophenone-3 in anti-solar preparations.

    Science.gov (United States)

    do Nascimento, Débora Freitas; Silva, Anna Claudia; Mansur, Claudia Regina Elias; Presgrave, Rosaura de Faria; Alves, Eloisa Nunes; Silva, Ronald Santos; Ricci-Júnior, Eduardo; de Freitas, Zaida Maria Faria; dos Santos, Elisabete Pereira

    2012-09-01

    Ultraviolet radiation can bring both harm and benefits to human health. Among those harms are erythemas, photosensitivity, photoaging, and the most worrying, skin cancer. Nanoencapsulation of sunscreen agents (SA) by using a biocompatible and biodegradable polymer such as poly(epsilon-caprolactone) (PCL) is advantageous as it increases the retention of UV absorbers in the skin, avoids systemic absorption, and consequently, improves water resistance and stability of the preparation. The aim of this work is to develop, characterize, and study the encapsulation of 3 different SA: 2-ethylhexyl-p-methoxycinnamate, benzophenone-3, and octocrylene in PCL nanoparticles (Nps). Nps were prepared by the solvent emulsification and evaporation method. The process yield was calculated, and the Nps were characterized in terms of size, polydispersity index (PI), morphology, zeta potential (ZP), encapsulation efficiency (EE) (%), and sunscreen agent content (SAC). The final formulations were submitted to the hen's egg test-chorioallantoic membrane (HET-CAM), chorioallantoic membrane-trypan blue staining (CAM-TBS), red blood cell (RBC), Draize tests, in vitro release, in vitro sun protection factor (SPF), UVA protection factor (PF-UVA), and photostability. All the Nps were in the nanometric scale. PI showed monodisperse systems. ZP became more negative as the Np were lyophilized and were added to the formulations. EE varied from 84 to 90%. The SAC went from 44 to 65 microg of sunscreen agents by milligram of Np. The process yield went from 60 to 76%. Nps were predominantly spherical and elliptical forms. The addition of Np diminished the release of the SA. The SPF increased with Np presence and helped to maintain the PF-UVA after irradiation. The HET-CAM assay evaluated the formulation as slightly irritant, CAM-TBS and RBC tests as non irritant, and the Draize test as moderately irritant.

  6. Gene expression analysis of the rat testis after treatment with di(2-ethylhexyl) phthalate using cDNA microarray and real-time RT-PCR

    International Nuclear Information System (INIS)

    Kijima, Kazuyasu; Toyosawa, Kaoru; Yasuba, Masashi; Matsuoka, Nobuo; Adachi, Tetsuya; Komiyama, Masatoshi; Mori, Chisato

    2004-01-01

    To investigate the effects of di(2-ethylhexyl) phthalate (DEHP) on gene expression in rat testis, 6-week-old male Sprague-Dawley rats were given a single oral dose of 20 or 2000 mg/kg and euthanized 3, 6, 24, or 72 h thereafter. Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells were significantly increased in the testis at 24 and 72 h after the exposure to 2000 mg/kg of DEHP. On cDNA microarray analysis, in addition to apoptosis-related genes, genes associated with atrophy, APEX nuclease, MutS homologue (E. coli), testosterone-repressed-prostatic-message-2 (TRPM-2), connective tissue growth factor, collagen alpha 2 type V, and cell adhesion kinase were differentially expressed. To investigate the relationship between histopathological alteration and gene expression, we selected genes associated with apoptosis and analyzed their expression by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). With 20 mg/kg of DEHP treatment, bcl-2, key gene related to apoptosis, was increased. Up-regulation of bcl-2, inhibitor of Apaf-1/caspase-9/caspase-2 cascade of apoptosis, may be related to the fact that no morphological apoptotic change was induced after dosing of 20 mg/kg DEHP. With 2000 mg/kg of DEHP treatment, the apoptotic activator cascade, Fas/FasL, FADD/caspase-8/caspase-3 cascade, and Apaf-1/caspase-9/caspase-2 cascade were increased and bcl-2 was decreased. Thus, these gene regulations might lead the cells into apoptosis in the case of high exposure to DEHP. In contrast, FADD/caspase-10/caspase-6 cascade and caspase-11/caspase-3 cascade were not increased. These results indicate that the cascades of FADD/caspase-10/caspase-6 and caspase-11/caspase-3 are not related to apoptosis with DEHP treatment

  7. Environmentally relevant concentrations of di(2-ethylhexyl)phthalate exposure alter larval growth and locomotion in medaka fish via multiple pathways.

    Science.gov (United States)

    Yang, Wen-Kai; Chiang, Li-Fen; Tan, Shi-Wei; Chen, Pei-Jen

    2018-06-01

    Di(2-ethylhexyl)phthalate (DEHP) is a commonly used plasticizer, with evidence of ubiquitous human exposure and widespread occurrence in the aquatic environment. It is an emerging environmental pollutant with regulatory priority; however, most studies have focused on the toxicity of DEHP related to endocrine disruption and reproduction in mammals. The ecotoxicological impact of phthalates (e.g., DEHP) on early life stages of fish under environmentally relevant concentrations of chronic exposure remains unclear. In this study, 7-day post-hatching fry of medaka fish (Oryzias latipes) underwent 21-day continuous exposure to DEHP solutions at 20, 100 and 200 μg/L to assess the effects on fish development and locomotion and related toxic mechanisms. Larval mortality was low with DEHP (20-200 μg/L) within 21 days, but such exposure significantly reduced fish body weight and length and altered swimming behavior. At 21 days, DEHP exposure resulted in specific patterns of larval locomotion (e.g., increased maximum velocity and absolute turn angle) and dose-dependently increased the mRNA expression of acetylcholinesterase (ache) but did not alter AChE activity. Transcriptional expression of antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione S-transferase and peroxisome proliferation-activated receptor and retinoid X receptor genes was significantly suppressed with 21-day DEHP exposure (20-200 μg/L), with marginal alteration in reactive oxygen species levels and antioxidant activities within the dosing period. As well, DEHP altered the mRNA expression of p53-regulated apoptosis pathways, such as upregulated p53, p21 and bcl-2 and downregulated caspase-3 expression, with increased enzymatic activity of caspase-3 in larvae. Our results suggest that toxic mechanisms of waterborne DEHP altered fish growth and locomotion likely via a combined effect of oxidative stress, neurotoxicity and apoptosis pathways. Copyright © 2018

  8. Mutagenicity of the peroxisome proliferators clofibrate, Wyeth 14,643 and di-2-ethylhexyl phthalate in the lacZ plasmid-based transgenic mouse mutation assay

    Directory of Open Access Journals (Sweden)

    Boerrigter Michaël

    2004-01-01

    Full Text Available Abstract Background Peroxisome proliferators are considered rodent carcinogens that are putative human non-carcinogens based on the presumed absence of direct genetic toxicity in rodent and human cells and the resistance of human cells to the induction of peroxisomes by peroxisome proliferators. The highly sensitive lacZ plasmid-based transgenic mouse mutation assay was employed to investigate the mutagenicity of several peroxisome proliferators based on several lines of evidence suggesting that these agents may in fact exert a genotoxic effect. Methods Male and female lacZ-plasmid based transgenic mice were treated at 4 months of age with 6 doses of 2,333 mg di-2-ethylhexyl phthalate (DHEP, 200 mg Wyeth-14,643, or 90 mg clofibrate per kg of bodyweight, respectively, over a two-week period. Control animals were treated with the respective vehicles only (35% propyl glycol for DEHP and Wyeth-14,643 treatment controls and sterile water for clofibrate treatment controls. The mutant frequency in liver, kidney and spleen DNA was determined as the proportion of retrieved mutant and wild-type lacZ plasmids expressed in Escherichia Coli C host cells employing a positive selection system for mutant plasmids. Results Exposure to DEHP or Wyeth-14,643 significantly increased the mutant frequency in liver, but not in kidney or spleen, of both female and male mice. Treatment with clofibrate did not lead to an increased mutant frequency in any of the organs studied. Conclusion The results indicate that some peroxisome proliferators display an organ-specific mutagenicity in lacZ plasmid-based transgenic mice consistent with historical observations of organ- and compound-specific carcinogenicity.

  9. DETERMINATION OF DIBUTYL PHTHALATE (DBP, BENZYL BUTYL PHTHALATE (BBP AND BIS (2-ETHYLHEXYL PHTHALATE (DEHP IN SOFT PLASTIC TOYS AND THE FIRST SURVEY OF THE BULGARIAN MARKET

    Directory of Open Access Journals (Sweden)

    Valentina CHRISTOVA-BAGDASSARIAN

    2017-12-01

    Full Text Available Phthalates are a large group of compounds with similar chemical structure widely used as plasticizers for plastics. They can easily be released from the polymer during usage and in this way enter the human body. Their adverse effect on health is known as "phthalate syndrome" and can impact children and adults alike. For children in particular, there is an additional potential risk of exposure to phthalates via toys intended for oral use. The Regulation (EC No 1907/2006 (REACH prohibits the use of bis (2-ethylhexyl phthalate (DEHP, di butyl phthalate (DBP and benzyl butyl phthalate (BBP as a substance or constituent of preparations at concentrations higher than 0.1 % in the plasticized material meant to toys and childcare items. The aim of this article is to quantify the content of DEHP, DBP and BBP in soft toys intended for children up to 3 years of age, including toys designed to be placed in the mouth. A method consisting of an extraction procedure of phthalates from polymers, purification of the extract, followed by GC/MS identification and quantification was validated. Three different techniques for phthalates’ extraction (Soxhlet, ultrasonic and vibrator were compared and the most effective one was chosen.This method was applied to the analysis of DEHP, DBP and BBP in soft toys from the Bulgarian market to establish their compliance with REACH requirements. All the tested toys contained at least one phthalate. Exceedence of the permitted content for DEHP, DBP and BBP (as sume, mainly due to the high levels of DEHP, was observed in several toys from retail.

  10. Possible Mechanisms of Di(2-ethylhexyl Phthalate-Induced MMP-2 and MMP-9 Expression in A7r5 Rat Vascular Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Mei-Fen Shih

    2015-12-01

    Full Text Available Proliferation and migration of vascular smooth muscle cells (VSMC are important in the development and/or progression of many cardiovascular diseases, including atherosclerosis. Evidence shows that matrix metalloproteinase (MMP-2 and MMP-9 are related to the pathogenesis of atherosclerosis. The expressions of MMP-2 and MMP-9 in atherosclerosis are regulated via various pathways, such as p38 mitogen activated protein kinase (MAPK, extracellular signal regulated kinase 1 and 2 (ERK1/2, Akt, and nuclear factor kappa (NF-κB. Di(2-ethylhexyl phthalate (DEHP has been shown to induce atherosclerosis by increasing tumor necrosis factor (TNF-α, interleukin (IL-6, and intercellular adhesion molecule (ICAM productions. However, whether DEHP poses any effects on MMP-2 or MMP-9 expression in VSMC has not yet been answered. In our studies, rat aorta VSMC was treated with DEHP (between 2 and 17.5 ppm and p38 MAPK, ERK1/2, Akt, NF-κB, and MMP-2 and MMP-9 proteins and activities were measured. Results showed that the presence of DEHP can induce higher MMP-2 and MMP-9 expression than the controls. Similar results on MMP-regulating proteins, i.e., p38 MAPK, ERK1/2, Akt, and NF-κB, were also observed. In summary, our current results have showed that DEHP can be a potent inducer of atherosclerosis by increasing MMP-2 and MMP-9 expression at least through the regulations of p38 MAPK, ERK1/2, Akt, and NF-κB.

  11. Toxic effects of di(2-ethylhexyl)phthalate on mortality, growth, reproduction and stress-related gene expression in the soil nematode Caenorhabditis elegans.

    Science.gov (United States)

    Roh, Ji-Yeon; Jung, In-Ho; Lee, Jai-Young; Choi, Jinhee

    2007-07-31

    In this study, di(2-ethylhexyl)phthalate (DEHP) toxicities to Caenorhabditis elegans were investigated using multiple toxic endpoints, such as mortality, growth, reproduction and stress-related gene expression, focusing on the identification of chemical-induced gene expression as a sensitive biomarker for DEHP monitoring. The possible use of C. elegans as a sentinel organism in the monitoring of soil ecosystem health was also tested by conducting the experiment on the exposure of nematode to field soil. Twenty-four-hour median lethal concentration (LC50) data suggest that DEHP has a relatively high potential of acute toxicity to C. elegans. Decreases in body length and egg number per worm observed after 24h of DEHP exposure may induce long-term alteration in the growth and reproduction of the nematode population. Based on the result from the C. elegans genome array and indicated in the literatures, stress proteins, metallothionein, vitellogenin, xenobiotic metabolism enzymes, apoptosis-related proteins, and antioxidant enzyme genes were selected as stress-related genes and their expression in C. elegans by DEHP exposure was analyzed semi-quantitatively. Expression of heat shock protein (hsp)-16.1 and hsp-16.2 genes was decreased by DEHP exposure. Expression of cytochrome P450 (cyp) 35a2 and glutathione-S-transferease (gst)-4, phase I and phase II of xenobiotic metabolism enzymes, was increased by DEHP exposure in a concentration-dependent manner. An increase in stress-related gene expressions occurred concomitantly with the deterioration on the physiological level, which suggests an increase in expression of those genes may not be considered as a homeostatic response but as a toxicity that might have physiological consequences. The experiment with the soil from the landfill site suggests that the potential of the C. elegans biomarker identified in laboratory conditions should be calibrated and validated for its use in situ.

  12. Di-(2-ethylhexyl) phthalate could disrupt the insulin signaling pathway in liver of SD rats and L02 cells via PPARγ

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wang; Shen, Xin-Yue; Zhang, Wen-wen; Chen, Hao [Institute of Clinical Pharmacology of Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine of Education Ministry, Anhui Collaborative Innovation Center of Anti-inflammatory and Immune Medicine, Hefei, 230032, Anhui (China); Xu, Wei-ping, E-mail: xu_weiping666@163.com [Affiliated Anhui Provincial Hospital, Anhui Medical University, Hefei 230001, Anhui (China); Wei, Wei, E-mail: wwei@ahmu.edu.cn [Institute of Clinical Pharmacology of Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine of Education Ministry, Anhui Collaborative Innovation Center of Anti-inflammatory and Immune Medicine, Hefei, 230032, Anhui (China)

    2017-02-01

    Di-(2-ethylhexyl)-phthalate (DEHP), a ubiquitous industrial pollutant in our daily life, has been reported to cause adverse effects on glucose homeostasis and insulin sensitivity in epidemiological studies previously. Recently, it has been reported to be an endocrine disrupter and ligand to peroxisome proliferator activated receptor, which could influence the homeostasis of liver metabolic systems and contribute to the development of type-2 diabetes. However, the potential mechanisms are not known yet. This study was designed to solve these problems with male SD rats and normal human hepatocyte line, L02 cells, exposed to DEHP for toxicological experiments. Adult male SD rats were divided into four groups, normal group fed with regular diets and three DEHP-treated groups (dissolved in olive oil at doses of 0.05, 5 and 500 mg/kg body weight, respectively, once daily through gastric intubations for 15 weeks). L02 cells were divided into 6 groups, normal group with 5, 10, 25, 50, and 100 μmol/l DEHP groups. DEHP-exposed rats exhibited significant liver damage, glucose tolerance, and insulin tolerance along with reduced expression of insulin receptor and GLUT4 proteins in the liver tissues. The results of in vitro experiments could determine that the DEHP-induced activation of peroxisome proliferator activated receptor γ (PPARγ) played a key role in the production of oxidative stress and down-regulated expression of insulin receptor and GLUT4 proteins in L02 cells. This conclusion could be supported by the results of in vitro experiments, in which the cells were exposed to DEHP with GW9662 (PPARγ inhibitor). In general, these results highlight the key role of PPARγ in the process of insulin resistance induced by DEHP. - Highlights: • DEHP exacerbates insulin resistance both in liver tissues and cells. • Expression of insulin receptor and GLUT4 were altered with PPARγ. • DEHP can induce oxidative stress to disrupt the metabolic homeostasis. • The dose of

  13. Architecture of Pd-Au bimetallic nanoparticles in sodium bis(2-ethylhexyl)sulfosuccinate reverse micelles as investigated by X-ray absorption spectroscopy.

    Science.gov (United States)

    Chen, Ching-Hsiang; Sarma, Loka Subramanyam; Chen, Jium-Ming; Shih, Shou-Chu; Wang, Guo-Rung; Liu, Din-Goa; Tang, Mau-Tsu; Lee, Jyh-Fu; Hwang, Bing-Joe

    2007-09-01

    In this study, we demonstrate the unique application of X-ray absorption spectroscopy (XAS) as a fundamental characterization tool to help in designing and controlling the architecture of Pd-Au bimetallic nanoparticles within a water-in-oil microemulsion system of water/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/n-heptane. Structural insights obtained from the in situ XAS measurements recorded at each step during the formation process revealed that Pd-Au bimetallic clusters with various Pd-Au atomic stackings are formed by properly performing hydrazine reduction and redox transmetalation reactions sequentially within water-in-oil microemulsions. A structural model is provided to explain reasonably each reaction step and to give detailed insight into the nucleation and growth mechanism of Pd-Au bimetallic clusters. The combination of in situ XAS analysis at both the Pd K-edge and the Au L(III)-edge and UV-vis absorption spectral features confirms that the formation of Pd-Au bimetallic clusters follows a (Pd(nuclei)-Au(stack))-Pd(surf) stacking. This result further implies that the thickness of Au(stack) and Pd(surf) layers may be modulated by varying the dosage of the Au precursor and hydrazine, respectively. In addition, a bimetallic (Pd-Au)(alloy) nanocluster with a (Pd(nuclei)-Au(stack))-(Pd-Au(alloy))(surf) stacking was also designed and synthesized in order to check the feasibility of Pd(surf) layer modification. The result reveals that the Pd(surf) layer of the stacked (Pd(nuclei)-Au)(stack) bimetallic clusters can be successfully modified to form a (Au-Pd alloy)(surf) layer by a co-reduction of Pd and Au ions by hydrazine. Further, we demonstrate the alloying extent or atomic distribution of Pd and Au in Pd-Au bimetallic nanoparticles from the derived XAS structural parameters. The complete XAS-based methodology, demonstrated here on the Pd-Au bimetallic system, can easily be extended to design and control the alloying extent or atomic distribution, atomic

  14. Selective extraction of U(VI) over Th(IV) from acidic streams using di-bis(2-ethylhexyl) malonamide anchored chloromethylated polymeric matrix

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, D.; Subramanian, M.S. [Department of Chemistry, Indian Institute of Technology, Chennai 600036 (India)

    2005-01-15

    A new chelating polymeric sorbent has been developed using Merrifield chloromethylated resin anchored with di-bis (2-ethylhexyl) malonamide (DB2EHM). The modified resin was characterized by {sup 13}C CPMAS NMR spectroscopy, FT-NIR-FIR spectroscopy, CHN elemental analysis and also by thermo gravimetric analysis. The fabricated sorbent showed superior binding affinity for U(VI) over Th(IV) and other diverse ions, even under high acidities. Various physio-chemical parameters, like solution acidity, phase exchange kinetics, metal sorption capacity, electrolyte tolerance studies, etc., influencing the resin's metal extractive behavior were studied by both static and dynamic method. Batch extraction studies performed over a wide range of solution acidity (0.01-10M) revealed that selective extraction of U(VI) could be achieved even up to 4M acidity with distribution ratios (D) in the order of circa 10{sup 3}. The phase exchange kinetics studies performed for U(VI) and Th(IV) revealed that time duration of <15min was sufficient for >99.5% extraction. But similar studies when preformed for trivalent lanthanides gave very low D values (<50), with the extraction time extending up to 60min. The metal sorption studies performed for U(VI) and Th(IV) at 5M HNO{sub 3} was found to be 62.5 and 38.2mgg{sup -1},respectively. Extraction efficiency in the presence of inferring electrolyte species and inorganic cations were also examined. Metal ion desorption was effective using 10-15mL of 1M (NH{sub 4}){sub 2}CO{sub 3} or 0.5M {alpha}-hydroxy isobutyric acid (HIBA). Extraction studies performed on a chromatographic column at 5M acidity were found to give enrichment factor values of 310 and 250 for U(VI) and Th(IV), respectively. The practical utility of the fabricated chelating sorbent and its efficiency to extract actinides from acidic waste streams was tested using a synthetic nuclear spent fuel solution. The R.S.D. values obtained on triplicate measurements (n = 3) were within

  15. Di-(2-ethylhexyl) phthalate could disrupt the insulin signaling pathway in liver of SD rats and L02 cells via PPARγ

    International Nuclear Information System (INIS)

    Zhang, Wang; Shen, Xin-Yue; Zhang, Wen-wen; Chen, Hao; Xu, Wei-ping; Wei, Wei

    2017-01-01

    Di-(2-ethylhexyl)-phthalate (DEHP), a ubiquitous industrial pollutant in our daily life, has been reported to cause adverse effects on glucose homeostasis and insulin sensitivity in epidemiological studies previously. Recently, it has been reported to be an endocrine disrupter and ligand to peroxisome proliferator activated receptor, which could influence the homeostasis of liver metabolic systems and contribute to the development of type-2 diabetes. However, the potential mechanisms are not known yet. This study was designed to solve these problems with male SD rats and normal human hepatocyte line, L02 cells, exposed to DEHP for toxicological experiments. Adult male SD rats were divided into four groups, normal group fed with regular diets and three DEHP-treated groups (dissolved in olive oil at doses of 0.05, 5 and 500 mg/kg body weight, respectively, once daily through gastric intubations for 15 weeks). L02 cells were divided into 6 groups, normal group with 5, 10, 25, 50, and 100 μmol/l DEHP groups. DEHP-exposed rats exhibited significant liver damage, glucose tolerance, and insulin tolerance along with reduced expression of insulin receptor and GLUT4 proteins in the liver tissues. The results of in vitro experiments could determine that the DEHP-induced activation of peroxisome proliferator activated receptor γ (PPARγ) played a key role in the production of oxidative stress and down-regulated expression of insulin receptor and GLUT4 proteins in L02 cells. This conclusion could be supported by the results of in vitro experiments, in which the cells were exposed to DEHP with GW9662 (PPARγ inhibitor). In general, these results highlight the key role of PPARγ in the process of insulin resistance induced by DEHP. - Highlights: • DEHP exacerbates insulin resistance both in liver tissues and cells. • Expression of insulin receptor and GLUT4 were altered with PPARγ. • DEHP can induce oxidative stress to disrupt the metabolic homeostasis. • The dose of

  16. Relationship between the ability of sunscreens containing 2-ethylhexyl-4'-methoxycinnamate to protect against UVR-induced inflammation, depletion of epidermal Langerhans (Ia+) cells and suppression of alloactivating capacity of murine skin in vivo.

    Science.gov (United States)

    Walker, S L; Morris, J; Chu, A C; Young, A R

    1994-01-01

    The UVB sunscreen 2-ethylhexyl-4'-methoxycinnamate was evaluated in hairless albino mouse skin for its ability to inhibit UVR-induced (i) oedema, (ii) epidermal Langerhans cell (Ia+) depletion and (iii) suppression of the alloactivating capacity of epidermal cells (mixed epidermal cell-lymphocyte reaction, MECLR). The sunscreen, prepared at 9% in ethanol or a cosmetic lotion, was applied prior to UVB/UVA irradiation. In some experiments there was a second application halfway through the irradiation. Single applications in both vehicles gave varying degrees of protection from oedema and Langerhans cell depletion but afforded no protection from suppression of MECLR. When the sunscreens were applied twice there was improved protection from oedema and Langerhans cell depletion and complete protection was afforded from suppression of MECLR. There was a clear linear relationship between Langerhans cell numbers and oedema with and without sunscreen application. The relationship between Langerhans cell numbers and MECLR was more complex. These data confirm published discrepancies between protection from oedema (a model for human erythema) and endpoints with immunological significance, but show that 2-ethylhexyl-4'-methoxycinnamate can afford complete immunoprotection, although protection is dependent on the application rate and vehicle.

  17. Emulsion liquid membrane for selective extraction of bismuth from nitrate medium

    International Nuclear Information System (INIS)

    Mokhtari, Bahram; Pourabdollah, Kobra

    2013-01-01

    The novelty of this work is the selective extraction of bismuth ions from nitrate medium by emulsion liquid membrane. Di(2-ethylhexyl)phosphoric acid was used as extractant of bismuth ions from nitrate medium by emulsion liquid membrane, and Triton X-100 was used as the biodegradable surfactant in n-pentanol n-pentanol bulk membrane. The extraction of bismuth ions was evaluated by the yield of extraction. The experimental parameters were evaluated and were optimized. They included the ratio of di(2-ethylhexyl)phosphoric acid concentration to the concentration of /Triton X-100 concentration (1.0 : 0.5% w/w), nature of diluents (n-pentanol), nature and concentration of the stripping solution (sulfuric acid, 0.5M), stirring speed (1,800 rpm) and equilibrium time of extraction (20min), initial feed solution of bismuth (350 ppm) and the volume ratio of the internal stripping phase to the membrane phase (14 times). The experimental parameters of kinetic extraction revealed that the bismuth ions were extracted at 100% 97%

  18. Emulsion liquid membrane for selective extraction of bismuth from nitrate medium

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, Bahram; Pourabdollah, Kobra [Islamic Azad University, Shahreza (Iran, Islamic Republic of)

    2013-07-15

    The novelty of this work is the selective extraction of bismuth ions from nitrate medium by emulsion liquid membrane. Di(2-ethylhexyl)phosphoric acid was used as extractant of bismuth ions from nitrate medium by emulsion liquid membrane, and Triton X-100 was used as the biodegradable surfactant in n-pentanol n-pentanol bulk membrane. The extraction of bismuth ions was evaluated by the yield of extraction. The experimental parameters were evaluated and were optimized. They included the ratio of di(2-ethylhexyl)phosphoric acid concentration to the concentration of /Triton X-100 concentration (1.0 : 0.5% w/w), nature of diluents (n-pentanol), nature and concentration of the stripping solution (sulfuric acid, 0.5M), stirring speed (1,800 rpm) and equilibrium time of extraction (20min), initial feed solution of bismuth (350 ppm) and the volume ratio of the internal stripping phase to the membrane phase (14 times). The experimental parameters of kinetic extraction revealed that the bismuth ions were extracted at 100% 97%.

  19. Nitrate glass

    International Nuclear Information System (INIS)

    Kirilenko, I.A.; Vinogradov, E.E.

    1977-01-01

    Experimental evidence on behaviour of nitrate glasses is reviewed in terms of relationships between the presence of water in vitrescent nitrate systems and the properties of the systems. The glasses considered belong to systems of Mg(NO 3 ) 2 - Nd(NO 3 ) 3 ; Hg(NO 3 ) 2 -Nd(NO 3 ) 3 ; NaNO 3 -Mg(NO 3 ) 2 -Nd(NO 3 ) 3 ; M-Zn(NO 3 ) 3 , where M is a mixture of 20% mass NaNO 3 and 80% mass Mg(NO 3 ) 2 , and Zn is a rare earth ion. Nitrate glass is shown to be a product of dehydration. Vitrification may be regarded as a resusl of formation of molecular complexes in the chain due to hydrogen bonds of two types, i.e. water-water, or water-nicrate group. Chain formation, along with low melting points of the nitrates, hinder crystallization of nitrate melts. Provided there is enough water, this results in vitrification

  20. Di(2-ethylhexyl)phthalate Alters the Synthesis and β-Oxidation of Fatty Acids and Hinders ATP Supply in Mouse Testes via UPLC-Q-Exactive Orbitrap MS-Based Metabonomics Study.

    Science.gov (United States)

    Shen, Guolin; Zhou, Lili; Liu, Wei; Cui, Yuan; Xie, Wenping; Chen, Huiming; Yu, Wenlian; Li, Wentao; Li, Haishan

    2017-06-21

    Di(2-ethylhexyl) phthalate (DEHP) is considered to be an environmental endocrine disruptor at high levels of general exposure. Studies show that DEHP may cause testicular toxicity on human being. In this study, metabonomics techniques were used to identify differential endogenous metabolites, draw the network metabolic pathways, and conduct network analysis, to determine the underlying mechanisms of testicular toxicity induced by DEHP. The results showed that DEHP inhibited synthesis and accelerated β-oxidation of fatty acids and impaired the tricarboxylic acid cycle (TCA cycle) and gluconeogenesis, resulting in lactic acid accumulation and an insufficient ATP supply in the microenvironment of the testis. These alterations led to testicular atrophy and, thus, may be the underlying causes of testicular toxicity. DEHP also inhibited peroxisome proliferator activated receptors in the testis, which may be another potential reason for the testicular atrophy. These findings provided new insights to better understand the mechanisms of testicular toxicity induced by DEHP exposure.

  1. Histone deacetylase 4 promotes ubiquitin-dependent proteasomal degradation of Sp3 in SH-SY5Y cells treated with di(2-ethylhexyl)phthalate (DEHP), determining neuronal death

    International Nuclear Information System (INIS)

    Guida, Natascia; Laudati, Giusy; Galgani, Mario; Santopaolo, Marianna; Montuori, Paolo; Triassi, Maria; Di Renzo, Gianfranco; Canzoniero, Lorella M.T.; Formisano, Luigi

    2014-01-01

    Phthalates, phthalic acid esters, are widely used as plasticizers to produce polymeric materials in industrial production of plastics and daily consumable products. Animal studies have shown that di(2-ethylhexyl)phthalate (DEHP) may cause toxic effects in the rat brain. In the present study, chronic exposure to DEHP (0.1–100 μM) caused dose-dependent cell death via the activation of caspase-3 in neuroblastoma cells. Intriguingly, this harmful effect was prevented by the pan-histone deacetylase (HDAC) inhibitor trichostatin A, by the class II HDAC inhibitor MC-1568, but not by the class I HDAC inhibitor MS-275. Furthermore, DEHP reduced specificity protein 3 (Sp3) gene expression, but not Sp3 mRNA, after 24 and 48 h exposures. However, Sp3 protein reduction was prevented by pre-treatment with MC-1568, suggesting the involvement of class II HDACs in causing this effect. Then, we investigated the possible relationship between DEHP-induced neuronal death and the post-translational mechanisms responsible for the down-regulation of Sp3. Interestingly, DEHP-induced Sp3 reduction was associated to its deacetylation and polyubiquitination. Co-immunoprecipitation studies showed that Sp3 physically interacted with HDAC4 after DEHP exposure, while HDAC4 inhibition by antisense oligodeoxynucleotide reverted the DEHP-induced degradation of Sp3. Notably, Sp3 overexpression was able to counteract the detrimental effect induced by DEHP. Taken together, these results suggest that DEHP exerts its toxic effect by inducing deacetylation of Sp3 via HDAC4, and afterwards, Sp3-polyubiquitination. - Highlights: • Di(2-ethylhexyl)phthalate (DEHP) is cytotoxic to SH-SY5Y cells and cortical neurons. • DEHP-induced cytotoxicity is mediated by apoptosis. • DEHP-induced apoptotic cell death is inhibited by class II HDAC MC-1568. • DEHP neurotoxicity is caused by HDAC4-mediated Sp3 degradation by ubiquitin

  2. Histone deacetylase 4 promotes ubiquitin-dependent proteasomal degradation of Sp3 in SH-SY5Y cells treated with di(2-ethylhexyl)phthalate (DEHP), determining neuronal death

    Energy Technology Data Exchange (ETDEWEB)

    Guida, Natascia; Laudati, Giusy [Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini 5, 80131 Naples (Italy); Galgani, Mario; Santopaolo, Marianna [Laboratorio di Immunologia, Istituto di Endocrinologia e Oncologia Sperimentale, Consiglio Nazionale delle Ricerche (IEOS-CNR), Napoli (Italy); Montuori, Paolo; Triassi, Maria [Department of Preventive Medical Sciences, University Federico II, Via Pansini 5, 80131 Naples (Italy); Di Renzo, Gianfranco [Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini 5, 80131 Naples (Italy); Canzoniero, Lorella M.T., E-mail: canzon@unisannio.it [Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini 5, 80131 Naples (Italy); Division of Pharmacology, Department of Science and Technology, University of Sannio, Via Port' Arsa 11, 82100 Benevento (Italy); Formisano, Luigi, E-mail: cformisa@unisannio.it [Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, School of Medicine, “Federico II” University of Naples, Via Pansini 5, 80131 Naples (Italy); Division of Pharmacology, Department of Science and Technology, University of Sannio, Via Port' Arsa 11, 82100 Benevento (Italy)

    2014-10-01

    Phthalates, phthalic acid esters, are widely used as plasticizers to produce polymeric materials in industrial production of plastics and daily consumable products. Animal studies have shown that di(2-ethylhexyl)phthalate (DEHP) may cause toxic effects in the rat brain. In the present study, chronic exposure to DEHP (0.1–100 μM) caused dose-dependent cell death via the activation of caspase-3 in neuroblastoma cells. Intriguingly, this harmful effect was prevented by the pan-histone deacetylase (HDAC) inhibitor trichostatin A, by the class II HDAC inhibitor MC-1568, but not by the class I HDAC inhibitor MS-275. Furthermore, DEHP reduced specificity protein 3 (Sp3) gene expression, but not Sp3 mRNA, after 24 and 48 h exposures. However, Sp3 protein reduction was prevented by pre-treatment with MC-1568, suggesting the involvement of class II HDACs in causing this effect. Then, we investigated the possible relationship between DEHP-induced neuronal death and the post-translational mechanisms responsible for the down-regulation of Sp3. Interestingly, DEHP-induced Sp3 reduction was associated to its deacetylation and polyubiquitination. Co-immunoprecipitation studies showed that Sp3 physically interacted with HDAC4 after DEHP exposure, while HDAC4 inhibition by antisense oligodeoxynucleotide reverted the DEHP-induced degradation of Sp3. Notably, Sp3 overexpression was able to counteract the detrimental effect induced by DEHP. Taken together, these results suggest that DEHP exerts its toxic effect by inducing deacetylation of Sp3 via HDAC4, and afterwards, Sp3-polyubiquitination. - Highlights: • Di(2-ethylhexyl)phthalate (DEHP) is cytotoxic to SH-SY5Y cells and cortical neurons. • DEHP-induced cytotoxicity is mediated by apoptosis. • DEHP-induced apoptotic cell death is inhibited by class II HDAC MC-1568. • DEHP neurotoxicity is caused by HDAC4-mediated Sp3 degradation by ubiquitin.

  3. Density and electrical conductivity of molten salts. Comparative study of binary mixtures of alkali nitrates with silver nitrate and with thallium nitrate; Densite et conductibilite de sels fondus. Etude comparative des melanges binaires nitrates alcalins-nitrate d'argent et nitrates alcalins-nitrate de thallium

    Energy Technology Data Exchange (ETDEWEB)

    Brillant, S [Commissariat a l' Energie Atomique Saclay (France). Centre d' Etudes Nucleaires

    1967-10-01

    The choice of methods and the number of measurements made enable us to give results on the density and electrical conductivity of molten binary mixtures, alkali nitrate and silver nitrate, and alkali nitrate and thallium nitrate, in the form of equations. The deviations from linearity of the volume and the molar conductivity are determined by calculating the corresponding excess values whose variations are analyzed as a function of the Tobolsky parameter. The absence of any relationship in the sign of the entropy and the excess volume is justified. It is shown that the silver and thallium nitrates, in contrast to the thermodynamic properties, behave as the alkali nitrates in so far as the excess conductivity is concerned. This result is confirmed by the study of changes in the activation enthalpy for the partial molar conductivity; this study also shows the particular behaviour of lithium nitrate. (author) [French] Le choix des methodes et le nombre de mesures effectuees nous permettent de donner les resultats de densite et de conductibilite electrique des melanges fondus binaires nitrate alcalin-nitrate d'argent et nitrate alcalin-nitrate de thallium sous forme d'equations. Les ecarts a la linearite des isothermes de volume et de conductibilite molaire sont precises en calculant les grandeurs d'exces correspondantes dont les variations sont analysees en fonction du parametre de Tobolsky. Nous justifions l'absence de relation de signe entre l'entropie et le volume d'exces. Nous montrons que les nitrates d'argent et de thallium, vis-a-vis de la conductibilite d'exces, contrairement aux proprietes thermodynamiques, se conduisent comme les nitrates alcalins. Ce resultat est confirme par l'etude des variations des enthalpies d'activation de conductibilite partielle molaire qui met d'autre part en evidence le comportement particulier du nitrate de lithium. (auteur)

  4. Ammonium nitrate-potassium nitrate system

    Energy Technology Data Exchange (ETDEWEB)

    Cady, H.H.

    1981-01-01

    A portion of the binary phase diagram for the system ammonium nitrate-potassium nitrate has been determined from -55/sup 0/C to 185/sup 0/C. Results are presented for the ammonium-nitrate-rich end of the system up to 30 wt% potassium nitrate.

  5. Aminoethyl nitrate – the novel super nitrate?

    Science.gov (United States)

    Bauersachs, Johann

    2009-01-01

    Long-term use of most organic nitrates is limited by development of tolerance, induction of oxidative stress and endothelial dysfunction. In this issue of the BJP, Schuhmacher et al. characterized a novel class of organic nitrates with amino moieties (aminoalkyl nitrates). Aminoethyl nitrate was identified as a novel organic mononitrate with high potency but devoid of induction of mitochondrial oxidative stress. Cross-tolerance to nitroglycerin or the endothelium-dependent agonist acetylcholine after in vivo treatment was not observed. Like all nitrates, aminoethyl nitrate induced vasorelaxation by activation of soluble guanylate cyclase. Thus, in contrast to the prevailing view, high potency in an organic nitrate is not necessarily accompanied by induction of oxidative stress or endothelial dysfunction. This work from Daiber's group is an important step forward in the understanding of nitrate bioactivation, tolerance phenomena and towards the development of better organic nitrates for clinical use. PMID:19732062

  6. Metabolism and disposition of 2-ethylhexyl-p-methoxycinnamate following oral gavage and dermal exposure in Harlan Sprague Dawley rats and B6C3F1/N mice and in hepatocytes in vitro.

    Science.gov (United States)

    Fennell, Timothy R; Mathews, James M; Snyder, Rodney W; Hong, Yan; Watson, Scott L; Black, Sherry R; McIntyre, Barry S; Waidyanatha, Suramya

    2017-11-23

    1. 2-Ethylhexyl-p-methoxycinnamate (EHMC) is commonly used as an ingredient in sunscreens, resulting in potential oral and dermal exposure in humans. 2. Clearance and metabolism of EHMC in hepatocytes and disposition and metabolism of EHMC in rodents following oral (8-800 mg/kg) intravenous (IV) (8 mg/kg) or dermal (0.8-80 mg/kg representing 0.1-10% formulation concentration) exposure to [ 14 C]EHMC were investigated in rats and mice. 3. EHMC was rapidly cleared from rat and mouse hepatocytes (half-life ≤3.16 min) and less rapidly (half-life ≤48 min) from human hepatocytes. 4. [ 14 C]EHMC was extensively absorbed and excreted primarily in urine by 72 h after oral administration to rats (65-80%) and mice (63-72%). Oral doses to rats were excreted to a lesser extent (3-8%) in feces and as CO 2 (1-4%). Radioactive residues in tissues were <1% of the dose. There were no sex or species differences in disposition in rats. 5. Following dermal application, 34-42% of an 8-mg/kg dose was absorbed in rats, and 54-62% in mice in 72-h. 6. Among numerous urinary metabolites associated with hydrolysis of the ester, two potential reproductive and developmental toxicants, 2-ethylhexanol and 2-ethylhexanoic acid were produced by metabolism of EHMC.

  7. Development of dispersive liquid-liquid microextraction technique using ternary solvents mixture followed by heating for the rapid and sensitive analysis of phthalate esters and di(2-ethylhexyl) adipate.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Khoshmaram, Leila

    2015-01-30

    In this study, for the first time, a dispersive liquid-liquid microextraction technique using a ternary solvent mixture is reported. In order to extract five phthalate esters and di(2-ethylhexyl) adipate with different polarities from aqueous samples, a simplex centroid experimental design method was used to select an optimal mixture of ternary solvents prior to gas chromatographyflame ionization detection. In this work, dimethyl formamide as a disperser solvent containing dichloromethane, chloroform, and carbon tetrachloride as a ternary extraction solvent mixture is injected into sample solution and a cloudy solution is formed. After centrifuging, 250μL of the obtained sedimented phase was transferred into another tube and 5μL DMF was added to it. Then, the tube was heated in a water bath at 75°C for 5min in order to evaporate the main portion of the extraction solvents. Finally, 2μL of the remained phase is injected into the separation system. Under the optimum extraction conditions, the method shows wide linear ranges and low limits of detection and quantification between 0.03-0.15 and 0.09-0.55μgL(-1), respectively. Enrichment factors and extraction recoveries are in the ranges of 980-4500 and 20-90%, respectively. The method is successfully applied in the determination of the target analytes in mineral water, soda, lemon juice, vinegar, dough, and yogurt packed in plastic packages. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Retour "écologique" sur la question des nitrates

    OpenAIRE

    Buson, Christian

    2012-01-01

    Un examen critique de la question des nitrates est proposé dans cet article, à la lumière des connaissances disponibles dans différentes disciplines. Au plan sanitaire, la norme sur l’eau potable établie depuis plusieurs décennies résulte d’une erreur ancienne aujourd’hui reconnue comme telle. Les nitrates n’engendrent aucun trouble sanitaire et les griefs tels que la méthémoglobinémie du nourrisson, ou le risque de cancer du à la formation de nitrosamines, qui les ont...

  9. Nitrates of rare earths

    International Nuclear Information System (INIS)

    Komissarova, L.N.; Pushkina, L.Ya.

    1984-01-01

    The systematization of experimental data with account of the last achievements in the field of studying the RE nitrate properties is realized. The methods of production, solubility in aqueous solutions structure, thermodynamic characteristics and thermal stability of nitrate hydrates, RE anhydrous and basic nitrates are considered. The data on RE nirtrate complexing in aqueous solutions are given. Binary nitrates, nitrate solvates and RE nitrate adducts with organic compounds are described. The use of RE nitrates in the course of RE production, in the processes of separation and fine cleaning of RE preparations is considered

  10. Involvement of a chromatin modifier in response to mono-(2-ethylhexyl) phthalate (MEHP)-induced Sertoli cell injury: Probably an indirect action via the regulation of NFκB/FasL circuitry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Shiwei [Department of Urology, 174th Hospital of PLA, Fujian 361001 (China); Dong, Yushu [Department of Neurosurgery, 463rd Hospital of PLA, Shenyang 110042 (China); Xu, Chun; Jiang, Liming; Chen, Yongjie; Jiang, Cheng [Department of Urology, 174th Hospital of PLA, Fujian 361001 (China); Hou, Wugang, E-mail: gangwuhou@163.com [Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi’an 710032 (China); Li, Wei, E-mail: liweipepeyato@163.com [Department of Human Anatomy, Histology and Embryology, Fourth Military Medical University, Xi’an 710032 (China)

    2013-11-01

    Highlights: •MTA1 expression is upregulated in SCs upon MEHP treatment. •Knockdown of MTA1 in SCs impairs the MEHP-induced NFκB signaling activation. •Knockdown of MTA1 inhibits recruitment of NFκB onto FasL promoter in MEHP-treated SCs. -- Abstract: The Fas/FasL signaling pathway, controlled by nuclear factor-κB (NFκB) at the transcriptional level, is critical for triggering germ cell apoptosis in response to mono-(2-ethylhexyl) phthalate (MEHP)-induced Sertoli cell (SC) injury, but the exact regulation mechanism remain unknown. Here, we discovered that expression level of Metastasis associated protein 1 (MTA1), a component of the Mi-2/nucleosome remodeling and deacetylase complex, was upregulated in SCs during the early recovery after MEHP exposure. This expression change was in line with the dynamic changes in germ cell apoptosis in response to MEHP treatment. Furthermore, a knockdown of MTA1 by RNAi in SCs was found to impair the MEHP-induced early activation of NFκB pathway and abolish the recruitment of NFκB onto FasL promoter, which consequently diminished the MEHP-triggered FasL induction. Considering that Fas/FasL is a well characterized apoptosis initiating signaling during SCs injury, our results point to a potential “switch on” effect of MTA1, which may govern the activation of NFκB/FasL cascade in MEHP-insulted SCs. Overall, the MTA1/NFκB/FasL circuit may serve as an important defensive/repairing mechanism to help to control the germ cell quality after SCs injury.

  11. Involvement of a chromatin modifier in response to mono-(2-ethylhexyl) phthalate (MEHP)-induced Sertoli cell injury: Probably an indirect action via the regulation of NFκB/FasL circuitry

    International Nuclear Information System (INIS)

    Chen, Shiwei; Dong, Yushu; Xu, Chun; Jiang, Liming; Chen, Yongjie; Jiang, Cheng; Hou, Wugang; Li, Wei

    2013-01-01

    Highlights: •MTA1 expression is upregulated in SCs upon MEHP treatment. •Knockdown of MTA1 in SCs impairs the MEHP-induced NFκB signaling activation. •Knockdown of MTA1 inhibits recruitment of NFκB onto FasL promoter in MEHP-treated SCs. -- Abstract: The Fas/FasL signaling pathway, controlled by nuclear factor-κB (NFκB) at the transcriptional level, is critical for triggering germ cell apoptosis in response to mono-(2-ethylhexyl) phthalate (MEHP)-induced Sertoli cell (SC) injury, but the exact regulation mechanism remain unknown. Here, we discovered that expression level of Metastasis associated protein 1 (MTA1), a component of the Mi-2/nucleosome remodeling and deacetylase complex, was upregulated in SCs during the early recovery after MEHP exposure. This expression change was in line with the dynamic changes in germ cell apoptosis in response to MEHP treatment. Furthermore, a knockdown of MTA1 by RNAi in SCs was found to impair the MEHP-induced early activation of NFκB pathway and abolish the recruitment of NFκB onto FasL promoter, which consequently diminished the MEHP-triggered FasL induction. Considering that Fas/FasL is a well characterized apoptosis initiating signaling during SCs injury, our results point to a potential “switch on” effect of MTA1, which may govern the activation of NFκB/FasL cascade in MEHP-insulted SCs. Overall, the MTA1/NFκB/FasL circuit may serve as an important defensive/repairing mechanism to help to control the germ cell quality after SCs injury

  12. Urinary metabolomic profiling in rats exposed to dietary di(2-ethylhexyl) phthalate (DEHP) using ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS).

    Science.gov (United States)

    Dong, Xinwen; Zhang, Yunbo; Dong, Jin; Zhao, Yue; Guo, Jipeng; Wang, Zhanju; Liu, Mingqi; Na, Xiaolin; Wang, Cheng

    2017-07-01

    Di(2-ethylhexyl) phthalate (DEHP) is an omnipresent environmental chemical with widespread nonoccupational human exposure through multiple ways. Although considerable efforts have been invested to investigate mechanisms of DEHP toxicity, the key metabolic biomarkers of DEHP toxicity remain to be identified. The aim of this study was to assess the urinary metabonomics of dietary DEHP in rats using the technique of ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS). Fourteen female Wistar rats were divided into two groups and given increasing dietary doses of DEHP for 30 consecutive days. The urinary metabolite profile was studied using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) enabled clusters to be clearly separated. Eleven principal urinary metabolites were identified as contributing to the clusters. The clusters in the positive electrospray ionization (ESI) mode were xanthurenic acid, kynurenic acid, nonate, N6-methyladenosine, and L-isoleucyl-L-proline. The clusters in the negative ESI mode were hippuric acid, tetrahydrocortisol, citric acid, phenylpropionylglycine, cPA(18:2(9Z, 12Z)/0:0), and LysoPC(14:1(9Z)). The urinary metabonomic changes indicated that exposure to dietary DEHP can affect energy-related metabolism, liver and renal function, fatty acid metabolism, and cause DNA damage in rats. The findings of this study on the urinary metabolites and metabolic pathways of DEHP may form the basis for future studies on the mechanisms of toxicity of this commonly found environmental chemical.

  13. Investigation of paramagnetic saturation in lanthanum manganese nitrate

    NARCIS (Netherlands)

    Flokstra, Jakob; Meijer, H.C.; Bots, G.J.C.; Verheij, W.A.; van der Marel, L.C.

    1973-01-01

    Paramagnetic saturation of lanthanum manganese nitrate, La2Mn3(NO3)12·24H2O, has been investigated at liquid He temperatures in a static as well as a dynamical way. With the aid of the molecular-field theory the Casimir and Du Pré dispersion and absorption curves are adapted explicitly to the

  14. Modeled Wet Nitrate Deposition

    Data.gov (United States)

    U.S. Environmental Protection Agency — Modeled data on nitrate wet deposition was obtained from Dr. Jeff Grimm at Penn State Univ. Nitrate wet depostion causes acidification and eutrophication of surface...

  15. Comparative effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP) on the aquatic larvae of Chironomus riparius based on gene expression assays related to the endocrine system, the stress response and ribosomes.

    Science.gov (United States)

    Planelló, Rosario; Herrero, Oscar; Martínez-Guitarte, José Luis; Morcillo, Gloria

    2011-09-01

    In this work, the effects of butyl benzyl phthalate (BBP) and di(2-ethylhexyl) phthalate (DEHP), two of the most extensively used phthalates, were studied in Chironomus riparius under acute short-term treatments, to compare their relative toxicities and identify genes sensitive to exposure. The ecotoxicity of these phthalates was assessed by analysis of the alterations in gene expression profiles of selected inducible and constitutive genes related to the endocrine system, the cellular stress response and the ribosomal machinery. Fourth instar larvae, a model system in aquatic toxicology, were experimentally exposed to five increasing concentrations (0.01, 0.1, 1, 10, and 100mg/L) of DEHP and BBP for 24h. Gene expression was analysed by the changes in levels of transcripts, using RT-PCR techniques with specific gene probes. The exposures to DEHP or BBP were able to rapidly induce the hsp70 gene in a concentration-dependent manner, whereas the cognate form hsc70 was not altered by either of these chemicals. Transcription of ribosomal RNA as a measure of cell viability, quantified by the levels of ITS2, was not affected by DEHP, but was slightly, yet significantly, downregulated by BBP at the highest concentrations tested. Finally, as these phthalates are classified as endocrine disruptor chemicals (EDCs), their potential effect on the ecdysone endocrine system was studied by analysing the two genes, EcR and usp, of the heterodimeric ecdysone receptor complex. It was found that BBP provoked the overexpression of the EcR gene, with significant increases from exposures of 0.1mg/L and above, while DEHP significantly decreased the activity of this gene at the highest concentration. These data are relevant as they show for the first time the ability of phthalates to interfere with endocrine marker genes in invertebrates, demonstrating their potential capacity to alter the ecdysone signalling pathway. Overall, the study clearly shows a differential gene-toxin interaction

  16. 21 CFR 181.33 - Sodium nitrate and potassium nitrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium nitrate and potassium nitrate. 181.33...-Sanctioned Food Ingredients § 181.33 Sodium nitrate and potassium nitrate. Sodium nitrate and potassium nitrate are subject to prior sanctions issued by the U.S. Department of Agriculture for use as sources of...

  17. Nitrate accumulation in spinach

    NARCIS (Netherlands)

    Steingröver, Eveliene Geertruda

    1986-01-01

    Leafy vegetables, like spinach, may contain high concentrations of nitrate. In the Netherlands, about 75% of mean daily intake of nitrate orginates from the consumption of vegatables. Hazards to human health are associated with the reduction of nitrate to nitrite. Acute nitrite poisoning causes

  18. Do nitrates differ?

    Science.gov (United States)

    Fung, H.-L.

    1992-01-01

    1 The organic nitrates all share a common biochemical and physiological mechanism of action. 2 The organic nitrates differ substantially in their pharmacologic potency and pharmacokinetics. In vitro potency differences appear larger than the corresponding in vivo activities. 3 The duration of action of organic nitrates, after a single immediate-release dose, is governed by the pharmacokinetics of the drug. However, the duration of action of available sustained-release preparations, whatever the nitrate or formulation, is limited to about 12 h, due to the development of pharmacologic tolerance. 4 Nitrates do not appear to differ in their production of undesirable effects. PMID:1633079

  19. Nitrate pollution of groundwater

    International Nuclear Information System (INIS)

    Heaton, T.H.E.

    1986-01-01

    Concern about the possible health risks associated with the consumption of nitrate has led many countries, including South Africa, to propose that 10mg of nitrogen (as nitrate or nitrite) per liter should be the maximum allowable limit for domestic water supplies. Groundwater in certain parts of South Africa and Namibia contains nitrate in concentrations which exceed this limit. The CSIR's Natural Isotope Division has been studying the nitrogen isotope composition of the nitrate as an aid to investigation into the sources of this nitrate contamination

  20. Ammonium nitrate explosion hazards

    Directory of Open Access Journals (Sweden)

    Negovanović Milanka

    2015-01-01

    Full Text Available Ammonium nitrate (AN primarily is used as a fertilizer but it is also very important compound in the production of industrial explosives. The application of ammonium nitrate in the production of industrial explosives was related with the early era of Nobel dynamite and widely increased with the appearance of blasting agents such as ANFO and Slurry, in the middle of the last Century. Throughout the world millions of tons of ammonium nitrate are produced annually and handled without incident. Although ammonium nitrate generally is used safely, accidental explosions involving AN have high impact resulting in loss of lives and destruction of property. The paper presents the basic properties of ammonium nitrate as well as hazards in handling of ammonium nitrate in order to prevent accidents. Several accidents with explosions of ammonium nitrate resulted in catastrophic consequences are listed in the paper as examples of non-compliance with prescribed procedures.

  1. Cloning and nitrate induction of nitrate reductase mRNA

    OpenAIRE

    Cheng, Chi-Lien; Dewdney, Julia; Kleinhofs, Andris; Goodman, Howard M.

    1986-01-01

    Nitrate is the major source of nitrogen taken from the soil by higher plants but requires reduction to ammonia prior to incorporation into amino acids. The first enzyme in the reducing pathway is a nitrate-inducible enzyme, nitrate reductase (EC 1.6.6.1). A specific polyclonal antiserum raised against purified barley nitrate reductase has been used to immunoprecipitate in vivo labeled protein and in vitro translation products, demonstrating that nitrate induction increases nitrate reductase p...

  2. Agricultural nitrate pollution

    DEFF Research Database (Denmark)

    Anker, Helle Tegner

    2015-01-01

    Despite the passing of almost 25 years since the adoption of the EU Nitrates Directive, agricultural nitrate pollution remains a major concern in most EU Member States. This is also the case in Denmark, although a fairly strict regulatory regime has resulted in almost a 50 per cent reduction...

  3. Nitrate leaching index

    Science.gov (United States)

    The Nitrate Leaching Index is a rapid assessment tool that evaluates nitrate (NO3) leaching potential based on basic soil and climate information. It is the basis for many nutrient management planning efforts, but it has considerable limitations because of : 1) an oversimplification of the processes...

  4. Thermochemical nitrate reduction

    International Nuclear Information System (INIS)

    Cox, J.L.; Lilga, M.A.; Hallen, R.T.

    1992-09-01

    A series of preliminary experiments was conducted directed at thermochemically converting nitrate to nitrogen and water. Nitrates are a major constituent of the waste stored in the underground tanks on the Hanford Site, and the characteristics and effects of nitrate compounds on stabilization techniques must be considered before permanent disposal operations begin. For the thermochemical reduction experiments, six reducing agents (ammonia, formate, urea, glucose, methane, and hydrogen) were mixed separately with ∼3 wt% NO 3 - solutions in a buffered aqueous solution at high pH (13); ammonia and formate were also mixed at low pH (4). Reactions were conducted in an aqueous solution in a batch reactor at temperatures of 200 degrees C to 350 degrees C and pressures of 600 to 2800 psig. Both gas and liquid samples were analyzed. The specific components analyzed were nitrate, nitrite, nitrous oxide, nitrogen, and ammonia. Results of experimental runs showed the following order of nitrate reduction of the six reducing agents in basic solution: formate > glucose > urea > hydrogen > ammonia ∼ methane. Airnmonia was more effective under acidic conditions than basic conditions. Formate was also effective under acidic conditions. A more thorough, fundamental study appears warranted to provide additional data on the mechanism of nitrate reduction. Furthermore, an expanded data base and engineering feasibility study could be used to evaluate conversion conditions for promising reducing agents in more detail and identify new reducing agents with improved performance characteristics

  5. Fiche technique du spermogramme et du spermocytogramme ...

    African Journals Online (AJOL)

    En Afrique la stérilité du couple constitue un drame social. Selon l'OMS, environ 8 à 12 % des couples africains sont touchés par une infertilité. La responsabilité masculine dans la stérilité est comprise entre 30 à 40%. Les causes de l'infertilité masculine peuvent être l'impuissance et/ ou l'altération du sperme. L'étude de ...

  6. Les Cahiers du CREAD

    African Journals Online (AJOL)

    Admin

    politique de bas prix exercée par la Russie et le Qatar vient confirmer ce constat ; s'ajoute à cela l'entrée éventuelle du gaz non conven- tionnel, dont son prix actuel de 3/4 $US, offre aux USA l'opportunité d'être exportateur de ..... les compagnies à produire en matière du gaz naturel, tels le prix du gaz naturel, le prix des ...

  7. Bulletin du CRDI #124

    International Development Research Centre (IDRC) Digital Library (Canada)

    Les femmes jouent un rôle important dans les exploitations minières artisanales et à petite échelle en Afrique subsaharienne. De concert ... Couverture du livre: Une vie saine pour les femmes et les enfants vulnérables · Couverture du livre: Entre el activismo y la intervención · Couverture du livre: Revitalizing Health for All.

  8. Bulletin du CRDI #125

    International Development Research Centre (IDRC) Digital Library (Canada)

    L'IOSRS remporte le prix de la diplomatie scientifique · GrowInclusive : la plateforme tant attendue est en construction · Toutes les nouvelles. Activités à venir. Semaine du développement international 2018. Le CRDI célébrera la Semaine du développement international du 4 au 10 février 2018. Suivez-nous sur Twitter et ...

  9. Reactivity of Metal Nitrates.

    Science.gov (United States)

    1982-07-20

    02NOCuOH Any mechanism suggested for the nitration of aromatic systems by titanium(IV) nitrate must take into account the observed similarity, in...occurs. -26- References 1. For recent reviews see (a) R. B. Moodie and K. Schofield, Accounts Chem. Res., 1976, 9, 287; (b) G. A. Olah and S. J. Kuhn...Ithaca, N.Y., 1969, Chapter VI; L. M. Stock, Prog. Phys. Org. Chem., 1976, 12, 21; J. G. Hoggett , R. B. Moodie, J. R. Penton, and K. Schofield

  10. "Cirque du Freak."

    Science.gov (United States)

    Rivett, Miriam

    2002-01-01

    Considers the marketing strategies that underpin the success of the "Cirque du Freak" series. Describes how "Cirque du Freak" is an account of events in the life of schoolboy Darren Shan. Notes that it is another reworking of the vampire narrative, a sub-genre of horror writing that has proved highly popular with both adult and…

  11. The biokinetics of uranium migrating from embedded DU fragments

    International Nuclear Information System (INIS)

    Leggett, R.W.; Pellmar, T.C.

    2003-01-01

    Military uses of depleted uranium (DU) munitions have resulted in casualties with embedded DU fragments. Assessment of radiological or chemical health risks from these fragments requires a model relating urinary U to the rate of migration of U from the fragments, and its accumulation in systemic tissues. A detailed biokinetic model for U has been published by the International Commission on Radiological Protection (ICRP), but its applicability to U migrating from embedded DU fragments is uncertain. Recently, ) conducted a study at the Armed Forces Radiobiology Research Institute (AFRRI) on the redistribution and toxicology of U in rats with implanted DU pellets, simulating embedded fragments. This paper compares the biokinetic data from that study with the behavior of commonly studied forms of U in rats (e.g., intravenously injected U nitrate). The comparisons indicate that the biokinetics of U migrating from embedded DU is similar to that of commonly studied forms of U with regard to long-term accumulation in kidneys, bone, and liver. The results provide limited support for the application of the ICRP's model to persons with embedded DU fragments. Additional information is needed with regard to the short-term behavior of migrating U and its accumulation in lymph nodes, brain, testicles, and other infrequently studied U repositories

  12. Phase extraction equilibria in systems rare earth (3) nitrates-ammonium nitrate-water-trialkylmethylammonium nitrate

    International Nuclear Information System (INIS)

    Pyartman, A.K.; Kopyrin, A.A.; Puzikov, E.A.

    1995-01-01

    The distribution of rare earth metals (3) between aqueous and organic phases in the systems rare earth metal (3) (praseodymium-lutetium (3), yttrium (3)) nitrate-ammonium nitrate-water-trialkylmethylammonium (kerosene diluent nitrate has been studied. It is shown that in organic phase di- and trisolvates of metals (3) with tralkylmethylammonium nitrate are formed. The influence of concentration of rare earth metal (3) nitrate and ammonium nitrate on the values of extraction concentrational constants has been ascertained: they decrease with increase in the ordinal number of lanthanide (3). 11 refs., 4 figs. 1 tab

  13. Nitrate Leaching Management

    Science.gov (United States)

    Nitrate (NO3) leaching is a significant nitrogen (N) loss process for agriculture that must be managed to minimize NO3 enrichment of groundwater and surface waters. Managing NO3 leaching should involve the application of basic principles of understanding the site’s hydrologic cycle, avoiding excess ...

  14. Waterproofing Materials for Ammonium Nitrate

    OpenAIRE

    R.S. Damse

    2004-01-01

    This study explores the possibility of overcoming the problem of hygroscopicity of ammonium nitrate by coating the particles with selected waterproofing materials. Gravimetric analysis ofthe samples of ammonium nitrate coated with eight different waterproofing materials, vis-a-vis, uncoated ammonium nitrate, were conducted at different relative humidity and exposuretime. The results indicate that mineral jelly is the promising waterproofing material for ammonium nitrate among the materials te...

  15. Uranyl nitrate-exposed rat alveolar macrophages cell death: Influence of superoxide anion and TNF α mediators

    International Nuclear Information System (INIS)

    Orona, N.S.; Tasat, D.R.

    2012-01-01

    Uranium compounds are widely used in the nuclear fuel cycle, military and many other diverse industrial processes. Health risks associated with uranium exposure include nephrotoxicity, cancer, respiratory, and immune disorders. Macrophages present in body tissues are the main cell type involved in the internalization of uranium particles. To better understand the pathological effects associated with depleted uranium (DU) inhalation, we examined the metabolic activity, phagocytosis, genotoxicity and inflammation on DU-exposed rat alveolar macrophages (12.5–200 μM). Stability and dissolution of DU could differ depending on the dissolvent and in turn alter its biological action. We dissolved DU in sodium bicarbonate (NaHCO 3 100 mM) and in what we consider a more physiological vehicle resembling human internal media: sodium chloride (NaCl 0.9%). We demonstrate that uranyl nitrate in NaCl solubilizes, enters the cell, and elicits its cytotoxic effect similarly to when it is diluted in NaHCO 3 . We show that irrespective of the dissolvent employed, uranyl nitrate impairs cell metabolism, and at low doses induces both phagocytosis and generation of superoxide anion (O 2 − ). At high doses it provokes the secretion of TNFα and through all the range of doses tested, apoptosis. We herein suggest that at DU low doses O 2 − may act as the principal mediator of DNA damage while at higher doses the signaling pathway mediated by O 2 − may be blocked, prevailing damage to DNA by the TNFα route. The study of macrophage functions after uranyl nitrate treatment could provide insights into the pathophysiology of uranium‐related diseases. -- Highlights: ► Uranyl nitrate effect on cultured macrophages is linked to the doses and independent of its solubility. ► At low doses uranyl nitrate induces generation of superoxide anion. ► At high doses uranyl nitrate provokes secretion of TNFα. ► Uranyl nitrate induces apoptosis through all the range of doses tested.

  16. Ecologie du phytoplancton du lac Kivu

    Directory of Open Access Journals (Sweden)

    Sarmento, H.

    2008-01-01

    Full Text Available Speciation within the African Coffee Pathogen. Cet article analyse s'il est avantageux d'utiliser le compost au lieu de l'engrais minéral pour produire la laitue dans la zone urbaine et péri-urbaine de Yaoundé. Les résultats de terrain montrent l'obtention de rendements et profits plus élevés lorsqu'on utilise le compost. Les résultats de la fonction de production Cobb-Douglas prouvent que l'utilisation du compost est statistiquement significative pour expliquer la variation de rendement de la laitue et que le compost est l'intrant le plus productif. D'autres résultats montrent que le compost fournit la matière organique utile au sol et que les besoins d'irrigation en eau de la culture sont réduits grâce à l'utilisation du compost. Par conséquent, malgré le fait que l'application du compost demande une main-d'oeuvre beaucoup plus élevée, son utilisation est généralement bénéfique pour les agriculteurs vivant aux alentours de Yaoundé. Les programmes de vulgarisation de cet intrant pour encourager son adoption devraient donc figurer parmi les points prioritaires dans la politique agricole du gouvernement camerounais.

  17. Purification of alkali metal nitrates

    Science.gov (United States)

    Fiorucci, Louis C.; Gregory, Kevin M.

    1985-05-14

    A process is disclosed for removing heavy metal contaminants from impure alkali metal nitrates containing them. The process comprises mixing the impure nitrates with sufficient water to form a concentrated aqueous solution of the impure nitrates, adjusting the pH of the resulting solution to within the range of between about 2 and about 7, adding sufficient reducing agent to react with heavy metal contaminants within said solution, adjusting the pH of the solution containing reducing agent to effect precipitation of heavy metal impurities and separating the solid impurities from the resulting purified aqueous solution of alkali metal nitrates. The resulting purified solution of alkali metal nitrates may be heated to evaporate water therefrom to produce purified molten alkali metal nitrate suitable for use as a heat transfer medium. If desired, the purified molten form may be granulated and cooled to form discrete solid particles of alkali metal nitrates.

  18. Nitrate in drinking water

    DEFF Research Database (Denmark)

    Schullehner, Jörg

    is highly decentralized and fully relying on simple treated groundwater. At the same time, Denmark has an intensive agriculture, making groundwater resources prone to nitrate pollution. Drinking water quality data covering the entire country for over 35 years are registered in the public database Jupiter......Annual nationwide exposure maps for nitrate in drinking water in Denmark from the 1970s until today will be presented based on the findings in Schullehner & Hansen (2014) and additional work on addressing the issue of private well users and estimating missing data. Drinking water supply in Denmark....... In order to create annual maps of drinking water quality, these data had to be linked to 2,852 water supply areas, which were for the first time digitized, collected in one dataset and connected to the Jupiter database. Analyses of the drinking water quality maps showed that public water supplies...

  19. Du Pont de Nemours

    NARCIS (Netherlands)

    Ros JPM; LAE

    1994-01-01

    Dit rapport over Du Pont de Nemours (produktie van o.a. chemische stoffen) is gepubliceerd binnen het Samenwerkingsproject Procesbeschrijvingen Industrie Nederland (SPIN). In het kader van dit project is informatie verzameld over industriele bedrijven of industriele processen ter ondersteuning

  20. Nitrates and nitrites intoxications’ management

    Directory of Open Access Journals (Sweden)

    Alexandra Trif

    2007-12-01

    Full Text Available The study pointed out the major sources for clinical and subclinical intoxications with nitrates/nitrites (drinking water and nitrates containing fertilizers, circumstances that determine fertilizers to became sources of intoxication (excessive fertilization/consecutive high level of nitrates in fodders, free access of animals to the fertilizers, administration into the diet instead of natrium chloride, factors that determine high nitrates accumulation in fodders despite optimal fertilization (factors related to the plants, soil, clime, harvest methods, storage, agrotechnical measures, nitrates/nitrites toxicity (over 45 ppm nitrates in drinking water, over 0.5 g nitrate/100 g D.M fodder/diet, the factors that influence nitrates/nitrites toxicity ( species, age, rate of feeding, diet balance especially energetically, pathological effects and symptoms (irritation and congestions on digestive tract, resulting diarrhoea, transformation of hemoglobin into methemoglobin determining severe respiratory insufficiency, vascular collapse, low blood pressure inthe acute nitrates intoxication; hypotiroidism, hypovitaminosis A, reproductive disturbances(abortion, low rate of fertility, dead born offspring, diarrhoea and/or respiratory insufficiency in new born e.g. calves, immunosuppression, decrease of milk production in chronic intoxication. There were presented some suggestions concerning management practices to limit nitrate intoxication (analyze of nitrates/nitrites in water and fodders, good management of the situation of risk ,e .g. dilution of the diet with low nitrate content fodders, feeding with balanced diet in energy, protein, minerals and vitamins, accommodation to high nitrate level diet, avoid grazing one week after a frost period, avoid feeding chop green fodders stored a couple of days, monitoring of health status of animals fed with fodders containing nitrates at risk level, a.o..

  1. Les Cahiers du CREAD

    African Journals Online (AJOL)

    Admin

    6 juil. 2007 ... La problématique du développement du secteur de l'artisanat en. Algérie a été très peu abordée par les chercheurs, qu'ils soient universitaires ou .... La loi a institué une taxe d'apprentissage dont le taux a été fixé à. 1% de la ...

  2. Les outils du CERN

    CERN Multimedia

    1999-01-01

    C'est le plus grand centre mondial de recherche en physique des particules. Les outils du Laboratoire, accélérateurs et détecteurs de particules, figurent parmi les instruments scientifiques les plus complexes au monde. Des prix Nobels ont d'ailleurs été attribués aux physiciens du CERN pour leurs développements.

  3. Bulletin du CRDI #127

    International Development Research Centre (IDRC) Digital Library (Canada)

    La mise à l'échelle de la recherche et de l'innovation en vue de créer un impact social constitue une priorité pour la communauté du développement. Toutefois ... Nous avons renouvelé notre soutien à la recherche auprès du gouvernement de l'Inde ... Des femmes étudient à l'École supérieure d'infotronique d'Haïti.

  4. Mise en œuvre du Programme de Gestion Durable de l'Azote à l'échelle de deux petits bassins versants agricoles (Arquennes – Belgique et évaluation d'impact par le suivi des flux de nitrate aux exutoires et par modélisation numérique

    Directory of Open Access Journals (Sweden)

    Deneufbourg, M.

    2013-01-01

    Full Text Available Application of the Sustainable Nitrogen Management Program in two small agricultural watersheds (Arquennes – Belgium and impact evaluation by monitoring of nitrate fluxes at outlets and by numerical modeling. Four water catchments used by the Walloon Society of Water (SWDE in the rural village of Arquennes (Province of Hainaut, Belgium have been contaminated by nitrate (concentrations between 60 and 70 mg NO3-·l-1 for several years. The catchment basins (31 ha and 47 ha are located exclusively in a cultivated area on loamy soils. Since October 2004, these basins have been used as a pilot area for the environmental evaluation of good agricultural practices as regards nitrogen management (adaptation of amounts of mineral nitrogen fertilizers, farm manure management, soil cover after harvest, etc. thanks to monitoring by farmers. This approach fits into the general pattern of the Sustainable Nitrogen Management Program (PGDA in French, which implements the European Nitrates Directive as part of Walloon legislation. The second objective of the working scheme is to study and to set up a decision-making tool aimed at preventing the contamination of water by agricultural nitrate around water catchments. Two numerical models (SWAT and FEFLOW® were used together in order to simulate the passage of water and nitrogen from the soil surface to the water catchments outlets. Calibration and validation of models were based, among other things, on soil and subsoil characterization and on tracer testing in both saturated and unsaturated zones. Moreover crop yield, farming practices, water and nitrate fluxes in water catchments, groundwater levels and nitrate concentration in groundwater were monitored for eight years. The results of simulations show that the application of PGDA in Arquennes watersheds would lead to a decrease in nitrate concentration (to almost 50 mg NO3-·l-1 in water catchments in 2012. This expected improvement in water quality has been

  5. Lanthanum (samarium) nitrate-4-aminoantipyrine nitrate-water systems

    International Nuclear Information System (INIS)

    Starikova, L.I.; Zhuravlev, E.F.

    1985-01-01

    Using the isothermal method of cross-sections at 50 deg C systems lanthanum nitrate-4-aminoantipyrine nitrate-water (1), samarium nitrate-4-aminoantipyrine nitrate-water (2), are studied. Isotherms of system 1 consist of two crystallization branches of initial salt components. In system 2 formation of congruently soluble compounds of the composition Sm(No) 3 ) 3 xC 11 H 13 ON 3 xHNO 3 is established. Analytical, X-ray phase and thermogravimetric analysis of the isolated binary salt are carried out

  6. Nitrate biosensors and biological methods for nitrate determination.

    Science.gov (United States)

    Sohail, Manzar; Adeloju, Samuel B

    2016-06-01

    The inorganic nitrate (NO3‾) anion is present under a variety of both natural and artificial environmental conditions. Nitrate is ubiquitous within the environment, food, industrial and physiological systems and is mostly present as hydrated anion of a corresponding dissolved salt. Due to the significant environmental and toxicological effects of nitrate, its determination and monitoring in environmental and industrial waters are often necessary. A wide range of analytical techniques are available for nitrate determination in various sample matrices. This review discusses biosensors available for nitrate determination using the enzyme nitrate reductase (NaR). We conclude that nitrate determination using biosensors is an excellent non-toxic alternative to all other available analytical methods. Over the last fifteen years biosensing technology for nitrate analysis has progressed very well, however, there is a need to expedite the development of nitrate biosensors as a suitable alternative to non-enzymatic techniques through the use of different polymers, nanostructures, mediators and strategies to overcome oxygen interference. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Effet du Pediococcus acidilactici sur le bilan lipidique sanguin du ...

    African Journals Online (AJOL)

    Les résultats relatifs aux performances zootechniques ont montré que l'addition du probiotique a amélioré significativement le gain de poids pendant la phase de croissance se traduisant par un indice de consommation meilleur. Les dosages du cholestérol total, des triglycérides, du HDL et du LDL ont été déterminés à la ...

  8. Respiration of Nitrate and Nitrite.

    Science.gov (United States)

    Cole, Jeffrey A; Richardson, David J

    2008-09-01

    Nitrate reduction to ammonia via nitrite occurs widely as an anabolic process through which bacteria, archaea, and plants can assimilate nitrate into cellular biomass. Escherichia coli and related enteric bacteria can couple the eight-electron reduction of nitrate to ammonium to growth by coupling the nitrate and nitrite reductases involved to energy-conserving respiratory electron transport systems. In global terms, the respiratory reduction of nitrate to ammonium dominates nitrate and nitrite reduction in many electron-rich environments such as anoxic marine sediments and sulfide-rich thermal vents, the human gastrointestinal tract, and the bodies of warm-blooded animals. This review reviews the regulation and enzymology of this process in E. coli and, where relevant detail is available, also in Salmonella and draws comparisons with and implications for the process in other bacteria where it is pertinent to do so. Fatty acids may be present in high levels in many of the natural environments of E. coli and Salmonella in which oxygen is limited but nitrate is available to support respiration. In E. coli, nitrate reduction in the periplasm involves the products of two seven-gene operons, napFDAGHBC, encoding the periplasmic nitrate reductase, and nrfABCDEFG, encoding the periplasmic nitrite reductase. No bacterium has yet been shown to couple a periplasmic nitrate reductase solely to the cytoplasmic nitrite reductase NirB. The cytoplasmic pathway for nitrate reduction to ammonia is restricted almost exclusively to a few groups of facultative anaerobic bacteria that encounter high concentrations of environmental nitrate.

  9. dl-Asparaginium nitrate

    Science.gov (United States)

    Moussa Slimane, Nabila; Cherouana, Aouatef; Bendjeddou, Lamia; Dahaoui, Slimane; Lecomte, Claude

    2009-01-01

    In the title compound, C4H9N2O3 +·NO3 −, alternatively called (1RS)-2-carbamoyl-1-carboxy­ethanaminium nitrate, the asymmetric unit comprises one asparaginium cation and one nitrate anion. The strongest cation–cation O—H⋯O hydrogen bond in the structure, together with other strong cation–cation N—H⋯O hydrogen bonds, generates a succession of infinite chains of R 2 2(8) rings along the b axis. Additional cation–cation C—H⋯O hydrogen bonds link these chains into two-dimensional layers formed by alternating R 4 4(24) and R 4 2(12) rings. Connections between these layers are provided by the strong cation–anion N—H⋯O hydrogen bonds, as well as by one weak C—H⋯O inter­action, thus forming a three-dimensional network. Some of the cation–anion N—H⋯O hydrogen bonds are bifurcated of the type D—H⋯(A 1,A 2). PMID:21577586

  10. Les mots du jazz

    OpenAIRE

    Roueff, Olivier

    2007-01-01

    L’ouvrage d’André Schaeffner constitue la première analyse savante du jazz (1926). Il a marqué une étape importante dans le processus de réinvention du jazz en France en contribuant notamment, par sa réception et les polémiques qu’il a suscitées, à transformer l’identification du jazz d’une musique « américaine » à une musique « noire-américaine » (c’est-à-dire aux « racines » africaines). Les analyses proposées dans cet ouvrage, alors qu’elles désignaient des musiques que la critique de jazz...

  11. The ytterbium nitrate-quinoline (piperidine) nitrate-water system

    International Nuclear Information System (INIS)

    Khisaeva, D.A.; Boeva, M.K.; Zhuravlev, E.F.

    1985-01-01

    Using the method of cross sections the solubility of solid phases in the ytterbium nitrate-quinoline nitrate - water (1) and ytterbium nitrate-piperidine nitrate-water (2) systems is studied at 25 and 50 deg C. It is established, that in system 1 congruently melting compound of the composition Yb(NO 3 ) 3 x2C 9 H 7 NxHNO 3 x3H 2 O is formed. The new solid phase has been isolated as a preparation and subjected to chemical X-ray diffraction, differential thermal and IR spectroscopic analyses. Isotherms of system 2 in the studied range of concentrations and temperatures consist of two branches, corresponding to crystallization of tetruaqueous ytterbi um nitrate and nitric acid piperidine

  12. Nitrate storage and dissimilatory nitrate reduction by eukaryotic microbes

    DEFF Research Database (Denmark)

    Kamp, Anja; Høgslund, Signe; Risgaard-Petersen, Nils

    2015-01-01

    The microbial nitrogen cycle is one of the most complex and environmentally important element cycles on Earth and has long been thought to be mediated exclusively by prokaryotic microbes. Rather recently, it was discovered that certain eukaryotic microbes are able to store nitrate intracellularly......, suggesting that eukaryotes may rival prokaryotes in terms of dissimilatory nitrate reduction. Finally, this review article sketches some evolutionary perspectives of eukaryotic nitrate metabolism and identifies open questions that need to be addressed in future investigations....... and use it for dissimilatory nitrate reduction in the absence of oxygen. The paradigm shift that this entailed is ecologically significant because the eukaryotes in question comprise global players like diatoms, foraminifers, and fungi. This review article provides an unprecedented overview of nitrate...

  13. fibrosarcome du larynx

    African Journals Online (AJOL)

    pie du lit tumoral est employée comme complément thé- rapeutique [9] alors que la chimiothérapie est générale- ment indiquée dans les formes métastatiques. Le pronos- tic dépend essentiellement du degré de différentiation his- tologique. En fait, le fibrosarcome bien différencié est caractérisé par la fréquence de récidive ...

  14. du Chott Marouane

    African Journals Online (AJOL)

    plancton de 90 µm de vide de maille. Ils ont été conservés dans du formol à 5%. L'identification de l'espèce est basée sur des critères morphologiques [20]: la forme des furcas, les lobes frontaux des antennes des mâles, de l'organe copulateur (pénis) et du sac ovigère. Le comptage des soies furcales a été réalisé. L'étude ...

  15. Evaluation of nitrate destruction methods

    International Nuclear Information System (INIS)

    Taylor, P.A.; Kurath, D.E.; Guenther, R.

    1993-01-01

    A wide variety of high nitrate-concentration aqueous mixed [radioactive and Resource Conservation and Recovery Act (RCRA) hazardous] wastes are stored at various US Department of Energy (DOE) facilities. These wastes will ultimately be solidified for final disposal, although the waste acceptance criteria for the final waste form is still being determined. Because the nitrates in the wastes will normally increase the volume or reduce the integrity of all of the waste forms under consideration for final disposal, nitrate destruction before solidification of the waste will generally be beneficial. This report describes and evaluates various technologies that could be used to destroy the nitrates in the stored wastes. This work was funded by the Department of Energy's Office of Technology Development, through the Chemical/Physical Technology Support Group of the Mixed Waste Integrated Program. All the nitrate destruction technologies will require further development work before a facility could be designed and built to treat the majority of the stored wastes. Several of the technologies have particularly attractive features: the nitrate to ammonia and ceramic (NAC) process produces an insoluble waste form with a significant volume reduction, electrochemical reduction destroys nitrates without any chemical addition, and the hydrothermal process can simultaneously treat nitrates and organics in both acidic and alkaline wastes. These three technologies have been tested using lab-scale equipment and surrogate solutions. At their current state of development, it is not possible to predict which process will be the most beneficial for a particular waste stream

  16. Decomposition of metal nitrate solutions

    International Nuclear Information System (INIS)

    Haas, P.A.; Stines, W.B.

    1982-01-01

    Oxides in powder form are obtained from aqueous solutions of one or more heavy metal nitrates (e.g. U, Pu, Th, Ce) by thermal decomposition at 300 to 800 deg C in the presence of about 50 to 500% molar concentration of ammonium nitrate to total metal. (author)

  17. Mortality of nitrate fertiliser workers.

    Science.gov (United States)

    Al-Dabbagh, S; Forman, D; Bryson, D; Stratton, I; Doll, R

    1986-01-01

    An epidemiological cohort study was conducted to investigate the mortality patterns among a group of workers engaged in the production of nitrate based fertilisers. This study was designed to test the hypothesis that individuals exposed to high concentrations of nitrates might be at increased risk of developing cancers, particularly gastric cancer. A total of 1327 male workers who had been employed in the production of fertilisers between 1946 and 1981 and who had been occupationally exposed to nitrates for at least one year were followed up until 1 March 1981. In total, 304 deaths were observed in this group and these were compared with expected numbers calculated from mortality rates in the northern region of England, where the factory was located. Analysis was also carried out separately for a subgroup of the cohort who had been heavily exposed to nitrates--that is, working in an environment likely to contain more than 10 mg nitrate/m3 for a year or longer. In neither the entire cohort nor the subgroup was any significant excess observed for all causes of mortality or for mortality from any of five broad categories of cause or from four specific types of cancer. A small excess of lung cancer was noted more than 20 years after first exposure in men heavily exposed for more than 10 years. That men were exposed to high concentrations of nitrate was confirmed by comparing concentrations of nitrates in the saliva of a sample of currently employed men with control men, employed at the same factory but not in fertiliser production. The men exposed to nitrate had substantially raised concentrations of nitrate in their saliva compared with both controls within the industry and with men in the general population and resident nearby. The results of this study therefore weight against the idea that exposure to nitrates in the environment leads to the formation in vivo of material amounts of carcinogens. PMID:3015194

  18. les cahiers du cread

    African Journals Online (AJOL)

    Our Journal “les cahiers du cread” is a quarterly economic review publishing original findings of empirical research and theoretical debates on fields pertaining to our mission coverage (Macro Economics, Industrial Economics and Firms, Human Development & Social Economics, Agriculture & Environment). Other websites ...

  19. Synthesis and characterization of poly(2-ethylhexyl acrylate ...

    Indian Academy of Sciences (India)

    aZydex Industries, 25-A Gandhi Oil Mill Compound, Gorwa, Vadodara 390 016, India. bRubber ... of the polymers were measured by gel permeation chromatography (GPC) analysis. .... tone, diethyl carbonate, water, DMSO, DMF, etc. helps.

  20. Determination of di(2-ethylhexyl phthalate in plastic medical devices

    Directory of Open Access Journals (Sweden)

    Kostić Ivana S.

    2016-01-01

    Full Text Available The presence of DEHP in dialysis and infusion sets for peritoneal dialysis and parenteral nutrition, which are made of PVC and other plastic polymeric materials, were investigated. Phthalate determination was carried out by gas chromatography - mass spectrometry method (GC-MS. The results showed that the peritoneal dialysis set (bag and tubing made of PVC contains DEHP in significant amount, about 31 - 34%. Solution for peritoneal dialysis which was stored in the investigated PVC bag, contains low amount of DEHP, about 3.72 μg dm-3. Infusion bottles which are made of LDPE, also contain DEHP but in lower amount than PVC bags. LDPE bottle for packaging physiological saline solution (0.9% NaCl showed higher amount of DEHP than LDPE bottle for packaging Ringer’s solution. In contrast, solution stored in bottle with lower DEHP level, i.e. Ringer’s solution contained about three times higher concentration of DEHP than physiological saline solution stored in bottle with higher DEHP level. Concentrations of DEHP in Ringer’s solution and physiological saline solution are 17.30 and 5.83 μg dm-3, respectively. The obtained values are under estimated upper-bound dose of DEHP received by adult patients undergoing procedures of peritoneal dialysis and parenteral nutrition. [Projekat Ministarstva nauke Republike Srbije, III 41018

  1. Neodymium nitrate-tetraethylammonium nitrate-water system

    International Nuclear Information System (INIS)

    Khisaeva, D.A.; Boeva, M.K.

    1987-01-01

    Method of isothermal cross sections at 25 and 50 deg C is used to study solid phase solubility in the neodymium nitrate-tetraethylammonium nitrate-water system. Crystallization fields of congruently soluble compounds, the salt component ratio being 1:1:4H 2 O and 1:3:2H 2 O are detected. New solid phases are preparatively obtained and subjected to chemical, differential thermal, IR spectroscopic and X-ray diffraction analyses. The obtained compounds are acido-complexes in which nitrate groups enter into the first coordination sphere

  2. Comparaison du filtre adaptatif RIF et du filtre a base de reseau de ...

    African Journals Online (AJOL)

    Comparaison du filtre adaptatif RIF et du filtre a base de reseau de neurones pour le filtrage du courant de reference pour la commande du filtre actif parallele. C Benachaiba, A Bassou, B Mazari ...

  3. Nitrate photolysis in salty snow

    Science.gov (United States)

    Donaldson, D. J.; Morenz, K.; Shi, Q.; Murphy, J. G.

    2016-12-01

    Nitrate photolysis from snow can have a significant impact on the oxidative capacity of the local atmosphere, but the factors affecting the release of gas phase products are not well understood. Here, we report the first systematic study of the amounts of NO, NO2, and total nitrogen oxides (NOy) emitted from illuminated snow samples as a function of both nitrate and total salt (NaCl and Instant Ocean) concentration. We show that the release of nitrogen oxides to the gas phase is directly related to the expected nitrate concentration in the brine at the surface of the snow crystals, increasing to a plateau value with increasing nitrate, and generally decreasing with increasing NaCl or Instant Ocean (I.O.). In frozen mixed nitrate (25 mM) - salt (0-500 mM) solutions, there is an increase in gas phase NO2 seen at low added salt amounts: NO2 production is enhanced by 35% at low prefreezing [NaCl] and by 70% at similar prefreezing [I.O.]. Raman microscopy of frozen nitrate-salt solutions shows evidence of stronger nitrate exclusion to the air interface in the presence of I.O. than with added NaCl. The enhancement in nitrogen oxides emission in the presence of salts may prove to be important to the atmospheric oxidative capacity in polar regions.

  4. Yttrium Nitrate mediated Nitration of Phenols at room temperature in ...

    Indian Academy of Sciences (India)

    The described method is selective for phenols. ... the significant cause of post translational modification that can ... decades, significant attention was paid on nitration of phenols to .... Progress of the reaction can be noted visually. Yttrium.

  5. Le ministre du Commerce international du Canada rencontre des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    17 juil. 2017 ... La promotion de l'entrepreneuriat, la façon dont le commerce peut profiter aux femmes et à leur famille, et la création d'emplois pour les plus vulnérables étaient au coeur de la discussion en table ronde du ministre du Commerce international du Canada, l'honorable François-Philippe Champagne, et des ...

  6. Portage vaginal du streptocoque du groupe B chez la femme ...

    African Journals Online (AJOL)

    Introduction: le streptocoque du groupe B est le principal agent impliqué dans les infections materno-fœtales, les septicémies et les méningites du nouveau-né à terme. L'objectif est de déterminer le taux de portage maternel du streptocoque du groupe B (SGB) à terme. Méthodes: un prélèvement vaginal a été réalisé de ...

  7. Aux origines du monde

    CERN Multimedia

    2004-01-01

    "C'est l'histoire d'une aventure humaine, scientifique, international qui a vu le jour il y a cinquante ans, aux confins de la Suisse et du département de l'Ain. Le plus grand laboratoire de physique des particules du monde, le Cern, a été fondé en 1954. Les festivités organisées à l occasion de cet anniversaire connaîtront leur point d'orgue le 16 octobre prochain, avec portes-ouvertes, accueil de personallités et inauguration d'un monumnet spécifique, le Globe de l'innovation" (2 pages)

  8. CHOEUR DU CERN

    CERN Multimedia

    CHOEUR DU CERN

    2010-01-01

    Les répétitions du chœur du CERN reprendront le mercredi 15 septembre à 20.00 heures à l’amphithéâtre principal – bâtiment 500. Au programme la préparation de notre concert de Noël avec la Missa Brevis, KV115, de Léopold Mozart et de la musique de Noël d’Europe. Les personnes qui aiment chanter, notamment des sopranes et des ténors, sont les bienvenues. Pour tout contact s’adresser à : Baudouin Bleus - (tél.CERN 767 82 44) -(baudouin.bleus@cern.ch) ou Martin Gatehouse ( martin.gatehouse@wanadoo.fr) ou Jean-Paul Diss (jean-pauldiss@wanadoo.fr).  

  9. Variability of nitrate and phosphate

    Digital Repository Service at National Institute of Oceanography (India)

    Sardessai, S.; Sundar, D.

    Nitrate and phosphate are important elements of the biogeochemical system of an estuary. Observations carried out during the dry season April-May 2002, and March 2003 and wet season September 2002, show temporal and spatial variability of these two...

  10. Hepatiques du Surinam

    NARCIS (Netherlands)

    Jovet-Ast, S.

    1957-01-01

    Il n’existe pas, actuellement, de catalogue des Hépatiques du Surinam. Les Hépatiques de ce pays restent très peu connues. Cependant, certaines ont attiré l’attention des Bryologues et ont été citées dans quelques ouvrages anciens ou récents. Je ne ferai pas ici une révision complète de ces

  11. (l.) Medik du Maroc

    African Journals Online (AJOL)

    PR BOKO

    Résumé. Dipcadi serotinum (L.) Medik, est une plante de la famille des Hyacinthaceae, elle est largement utilisée comme réchauffant et aussi pour combattre la jaunisse. Cette plante trouve une large utilisation par la population de la région côtière du Maroc. À notre connaissance l'huile essentielle de cette espèce n'a ...

  12. Vasodilator Therapy: Nitrates and Nicorandil.

    Science.gov (United States)

    Tarkin, Jason M; Kaski, Juan Carlos

    2016-08-01

    Nitrates have been used to treat symptoms of chronic stable angina for over 135 years. These drugs are known to activate nitric oxide (NO)-cyclic guanosine-3',-5'-monophasphate (cGMP) signaling pathways underlying vascular smooth muscle cell relaxation, albeit many questions relating to how nitrates work at the cellular level remain unanswered. Physiologically, the anti-angina effects of nitrates are mostly due to peripheral venous dilatation leading to reduction in preload and therefore left ventricular wall stress, and, to a lesser extent, epicardial coronary artery dilatation and lowering of systemic blood pressure. By counteracting ischemic mechanisms, short-acting nitrates offer rapid relief following an angina attack. Long-acting nitrates, used commonly for angina prophylaxis are recommended second-line, after beta-blockers and calcium channel antagonists. Nicorandil is a balanced vasodilator that acts as both NO donor and arterial K(+) ATP channel opener. Nicorandil might also exhibit cardioprotective properties via mitochondrial ischemic preconditioning. While nitrates and nicorandil are effective pharmacological agents for prevention of angina symptoms, when prescribing these drugs it is important to consider that unwanted and poorly tolerated hemodynamic side-effects such as headache and orthostatic hypotension can often occur owing to systemic vasodilatation. It is also necessary to ensure that a dosing regime is followed that avoids nitrate tolerance, which not only results in loss of drug efficacy, but might also cause endothelial dysfunction and increase long-term cardiovascular risk. Here we provide an update on the pharmacological management of chronic stable angina using nitrates and nicorandil.

  13. Headspace Analysis of Ammonium Nitrate

    Science.gov (United States)

    2017-01-25

    explosive ammonium nitrate produces ammonia and nitric acid in the gaseous headspace above bulk solids, but the concentrations of the products have been...and NO2-, a product of nitrate fragmentation (Figure 7). Brief spikes in the background and dips in oxalic acid signal were observed at the time of...either filtered air or experimental nitric acid vapor sources so that analyte signal could be measured directly opposite background. With oxalic

  14. La mesure du danger

    CERN Document Server

    Manceron, Vanessa; Revet, Sandrine

    2014-01-01

    La mesure du danger permet d’explorer des dangers de nature aussi diverse que la délinquance, la pollution, l’écueil maritime, la maladie ou l’attaque sorcellaire, l’extinction d’espèces animales ou végétales, voire de la Planète tout entière. Au croisement de la sociologie, de l’anthropologie et de l’histoire, les différents articles analysent les pratiques concrètes de mesure pour tenter de comprendre ce qui se produit au cours de l’opération d’évaluation du danger sans préjuger de la nature de celui-ci. L’anthropologie a contribué à la réflexion sur l’infortune en s’intéressant aux temporalités de l’après : maladies, catastrophes, pandémies, etc. et en cherchant à rendre compte de l’expérience des victimes, de leur vie ordinaire bouleversée, de la recomposition du quotidien. Elle s’intéresse aussi aux autres types de mesures, les savoirs incorporés, qui reposent sur l’odorat, la vue ou le toucher et ceux qui ressortent d’une épistémologie « non ...

  15. Using Major Elements to Determine Sources of Nitrate in Groundwater, Suffolk County, Long Island, NY

    Science.gov (United States)

    Munster, J.; Hanson, G.; Bokuniewicz, H.

    2004-05-01

    . Major element data for groundwater from Suffolk County Water Authority municipal wells have been characterized as a function of capture zone land use (Source Water Assessment Project, CDM, 2003). The data for the groundwater and the waste water and the soil water were then compared. The elements Na, Mg, Cl, NO3 and SO4 proved most successful as nitrate tracers on element-element plots. There is a distinct relationship between land use and source of nitrate contamination such that ground waters sourced in: (1) low residential density areas (1 or less dwelling units per acre (DU/acre)) plot in turf grass cultivation fields (2) medium residential areas (2-10 DU/acre) and high residential areas (more than 10 DU/acre) plot as a mixture of turf grass cultivation and wastewater (3) agricultural areas plot in the turf grass cultivation field and (4) vacant or open land use plot close to average rain water compositions.

  16. EXTRACTION OF URANYL NITRATE FROM AQUEOUS SOLUTIONS

    Science.gov (United States)

    Furman, N.H.; Mundy, R.J.

    1957-12-10

    An improvement in the process is described for extracting aqueous uranyl nitrate solutions with an organic solvent such as ether. It has been found that the organic phase will extract a larger quantity of uranyl nitrate if the aqueous phase contains in addition to the uranyl nitrate, a quantity of some other soluble nitrate to act as a salting out agent. Mentioned as suitable are the nitrates of lithium, calcium, zinc, bivalent copper, and trivalent iron.

  17. Solubility isotherms in ternary systems of samarium nitrate, water and nitrates of amidopyrine, benzotriazole

    International Nuclear Information System (INIS)

    Starikova, L.I.

    1991-01-01

    Solubility in the system of samarium nitrate-amidopyrine nitrate-water at 25 and 50 deg C was studied. Solubility isotherms consist of three branches, corresponding to crystallization of samarium nitrate tetrahydrate, amidopyrine nitrate and congruently soluble compounds of Sm(NO 3 ) 3 · 2C 13 H 17 ON 3 ·HNO 3 composition. Its thermal behaviour was studied. The system of samarium nitrate-benzotriazole nitrate-water is referred to eutonic type

  18. Archives: les cahiers du cread

    African Journals Online (AJOL)

    Items 1 - 24 of 24 ... Archives: les cahiers du cread. Journal Home > Archives: les cahiers du cread. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. 1 - 24 of 24 Items. 2016 ...

  19. Le commerce du Nord

    OpenAIRE

    Pourchasse, Pierrick; Bouëdec, Gérard Le

    2015-01-01

    Au XVIIIe siècle, la France s'approvisionne abondamment dans les pays du Nord : bois, chanvre et goudron de la Baltique, tonnellerie de Poméranie, pêche de rogue de Norvège, graines de lin de Courlande, barres de fer suédois… Sa balance commerciale est pourtant positive grâce aux sels, aux vins et surtout des nouvelles marchandises coloniales. Or, la plupart des transactions passent par l’incontournable intermédiaire hollandais. Les explications sur l’absence des Français dans le Nord sont re...

  20. La voie du Centre

    OpenAIRE

    2017-01-01

    Après avoir quelque peu louvoyé dans un discours apparemment anarchique où les souvenirs semblent se bousculer sans autre fil conducteur que la référence obsédante au mal satanique, brusquement le narrateur annonce un événement primordial : Foi um fato que se deu, um dia, se abriu. O primeiro. Depois o senhor verá por quê, me devolvendo minha razão (79). Cette introduction situe la rencontre du Menino comme fondatrice d’un destin dont il reviendrait au narrataire de dégager les enchaînements....

  1. Bulletin du CRDI #126

    International Development Research Centre (IDRC) Digital Library (Canada)

    26 févr. 2018 ... Dans ce numéro, découvrez comment la recherche financée par le CRDI permet d'améliorer la santé des mères et des enfants dans les pays du Sud et comment les innovations techniques et sociales de l'initiative SEARCH permettent de surmonter les défis liés à la cybersanté. N'oubliez pas non plus de ...

  2. Catalyzed reduction of nitrate in aqueous solutions

    International Nuclear Information System (INIS)

    Haas, P.A.

    1994-08-01

    Sodium nitrate and other nitrate salts in wastes is a major source of difficulty for permanent disposal. Reduction of nitrate using aluminum metal has been demonstrated, but NH 3 , hydrazine, or organic compounds containing oxygen would be advantageous for reduction of nitrate in sodium nitrate solutions. Objective of this seed money study was to determine minimum conditions for reduction. Proposed procedure was batchwise heating of aqueous solutions in closed vessels with monitoring of temperatures and pressures. A simple, convenient apparatus and procedure were demonstrated for observing formation of gaseous products and collecting samples for analyses. The test conditions were 250 degree C and 1000 psi max. Any useful reduction of sodium nitrate to sodium hydroxide as the primary product was not found. The nitrate present at pHs 3 or NH 4 NO 3 is easily decomposed, and the effect of nitromethane at these low pHs was confirmed. When acetic acid or formic acid was added, 21 to 56% of the nitrate in sodium nitrate solutions was reduced by methanol or formaldehyde. With hydrazine and acetic acid, 73 % of the nitrate was decomposed to convert NaNO 3 to sodium acetate. With hydrazine and formic acid, 36% of the nitrate was decomposed. If these products are more acceptable for final disposal than sodium nitrate, the reagents are cheap and the conversion conditions would be practical for easy use. Ammonium acetate or formate salts did not significantly reduce nitrate in sodium nitrate solutions

  3. Uranyl nitrate-exposed rat alveolar macrophages cell death: Influence of superoxide anion and TNF α mediators

    Energy Technology Data Exchange (ETDEWEB)

    Orona, N.S. [School of Science and Technology, National University of General Martín, Avda Gral Paz 5445 (1650) San Martín, Buenos Aires (Argentina); Tasat, D.R., E-mail: deborah.tasat@unsam.edu.ar [School of Science and Technology, National University of General Martín, Avda Gral Paz 5445 (1650) San Martín, Buenos Aires (Argentina); School of Dentistry, University of Buenos Aires, M. T. de Alvear 2142 (1122), Buenos Aires (Argentina)

    2012-06-15

    Uranium compounds are widely used in the nuclear fuel cycle, military and many other diverse industrial processes. Health risks associated with uranium exposure include nephrotoxicity, cancer, respiratory, and immune disorders. Macrophages present in body tissues are the main cell type involved in the internalization of uranium particles. To better understand the pathological effects associated with depleted uranium (DU) inhalation, we examined the metabolic activity, phagocytosis, genotoxicity and inflammation on DU-exposed rat alveolar macrophages (12.5–200 μM). Stability and dissolution of DU could differ depending on the dissolvent and in turn alter its biological action. We dissolved DU in sodium bicarbonate (NaHCO{sub 3} 100 mM) and in what we consider a more physiological vehicle resembling human internal media: sodium chloride (NaCl 0.9%). We demonstrate that uranyl nitrate in NaCl solubilizes, enters the cell, and elicits its cytotoxic effect similarly to when it is diluted in NaHCO{sub 3}. We show that irrespective of the dissolvent employed, uranyl nitrate impairs cell metabolism, and at low doses induces both phagocytosis and generation of superoxide anion (O{sub 2}{sup −}). At high doses it provokes the secretion of TNFα and through all the range of doses tested, apoptosis. We herein suggest that at DU low doses O{sub 2}{sup −} may act as the principal mediator of DNA damage while at higher doses the signaling pathway mediated by O{sub 2}{sup −} may be blocked, prevailing damage to DNA by the TNFα route. The study of macrophage functions after uranyl nitrate treatment could provide insights into the pathophysiology of uranium‐related diseases. -- Highlights: ► Uranyl nitrate effect on cultured macrophages is linked to the doses and independent of its solubility. ► At low doses uranyl nitrate induces generation of superoxide anion. ► At high doses uranyl nitrate provokes secretion of TNFα. ► Uranyl nitrate induces apoptosis through

  4. Choeur du CERN : Concert

    CERN Multimedia

    CERN Choir

    2017-01-01

    Une œuvre à découvrir! La grande Missa pro defunctis de François-Joseph Gossec (1734-1829) est le chef-d’œuvre tôt venu (à vingt-cinq ans) d’un compositeur qui vivra encore 70 ans après sa création. Elle a connu la gloire, puis s’est fait un peu oublier. Pas du tout le monde cependant : des musicologues ont montré ce que le Requiem de Mozart lui devait ; et il suffit de l’avoir entendue pour comprendre pourquoi Berlioz (qui avait vingt-six ans à la mort de Gossec) en a été impressionné : les nombreux cuivres et bois répartis dans des endroits plus ou moins cachés de la salle de concert pour exprimer les frayeurs du Jugement dernier annoncent son Requiem – et celui de Verdi. Mais « plus encore que par...

  5. Les risques du travail

    CERN Document Server

    Thébaud-Mony, Annie

    2015-01-01

    Depuis les années 1990, les conditions de travail se sont peu à peu imposées dans le débat social. Néanmoins, la situation reste critique. Les risques traditionnels n'ont pas disparu : les manutentions lourdes, l'exposition professionnelle aux cancérogènes, au bruit ou aux vibrations demeurent répandues... De plus, certaines " améliorations " n'ont fait que déplacer et dissimuler les problèmes, telle l'externalisation des risques grâce à la sous-traitance. Dans le même temps, les transformations du travail et des modalités de gestion de la main-d'œuvre ont fragilisé les collectifs et accru l'isolement des salariés, conduisant à une montée visible de la souffrance psychique. Face à ces évolutions, il est plus que jamais nécessaire que tous les acteurs concernés, en particulier les salariés eux-mêmes et leurs représentants, s'approprient les connaissances indispensables pour améliorer la protection de la santé sur les lieux du travail. Tel est le but de ce livre, qui renouvelle int�...

  6. Efficiency of nitrate uptake in spinach : impact of external nitrate concentration and relative growth rate on nitrate influx and efflux

    NARCIS (Netherlands)

    Ter Steege, MW; Stulen, [No Value; Wiersema, PK; Posthumus, F; Vaalburg, W

    1999-01-01

    Regulation of nitrate influx and efflux in spinach (Spinacia oleracea L., cv. Subito), was studied in short-term label experiments with N-13- and N-15-nitrate. Nitrate fluxes were examined in relation to the N demand for growth, defined as relative growth rate (RGR) times plant N concentration.

  7. Jouer du piano

    Directory of Open Access Journals (Sweden)

    Fériel Kaddour

    2011-04-01

    Full Text Available La réflexion s’appuie dans un premier temps sur une opposition entre deux attitudes de pianistes  à l’égard du travail à l’instrument : Gould, qui revendique une séparation d’avec le clavier pour ne privilégier que la lecture; Arrau, dont la technique au contraire vise à « faire corps » avec son piano. L’étude de ces deux démarches d’interprètes conduit à une conclusion croisée : l’abstraction gouldienne n’est rien d’autre qu’un déplacement du jeu vers d’autres instruments (ceux qui servent à la prise de son et au montage de ses enregistrements ; le « faire-corps » hérité de la culture pianistique romantique est plus dialectique que fusionnel, et en cela implique une capacité de mise à distance. A partir de cette double conclusion, on tâche enfin de repenser la place du jeu à l’instrument dans la mise en œuvre d’une interprétation, en interrogeant le dialogue qui s’instaure entre la partition telle qu’elle s’écrit et le geste tel qu’il se joue.Our study leans on an opposition between two pianists' attitudes about their work with the instrument. Gould claims a necessary separation from the keyboard in order to prioritize reading. Arrau, on the contrary, relies on a technique which consists in “being one” with his piano. The analysis of these two interprets’ behaviours leads to a crossed conclusion: the gouldian abstraction is nothing else than a displacement of the playing towards another kind of instruments, the ones he uses in sound recording and cut up; Arrau’s “being one” is more dialectic than at first sight, and it therefore implies a real distancing from the piano. This constatation leads to rethink the place of the piano playing in the setting of an interpretation, and to highlight the real dialogue which develops itself between the score as it has been written and the gesture as it is played.

  8. Thermal Decomposition Of Hydroxylamine Nitrate

    Science.gov (United States)

    Oxley, Jimmie C.; Brower, Kay R.

    1988-05-01

    used hydroxylamine nitrate decomposes within a few minutes in the temperature range 130-140°C. Added ammonium ion is converted to N2, while hydrazinium ion is converted to HN3. Nitrous acid is an intermediate and its formation is rate-determining. A hygride transfer process is postulated. The reaction pathways have been elucidated by use of N tracers.

  9. Nitrate and bicarbonate selective CHEMFETs

    NARCIS (Netherlands)

    Antonisse, M.M.G.; Engbersen, Johannes F.J.; Reinhoudt, David

    1995-01-01

    The development of durable anion selective CHEMFET micro sensors is described. Selectivity in these sensors is either obtained from differences in hydration energy of the anions (the Hlofmeister series, giving nitrate selectivity) or by introduction of a new class of uranyl salophene ionophores

  10. Nitrate Removal from Ground Water: A Review

    OpenAIRE

    Archna; Sharma, Surinder K.; Sobti, Ranbir Chander

    2012-01-01

    Nitrate contamination of ground water resources has increased in Asia, Europe, United States, and various other parts of the world. This trend has raised concern as nitrates cause methemoglobinemia and cancer. Several treatment processes can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation. Available technical data, experience, and economics indicate that biological denitrification is more acceptable for nitrate removal than reverse osmosis and ion ex...

  11. La grammaticalisation du monde.

    Directory of Open Access Journals (Sweden)

    Etienne Pingaud

    2010-01-01

    Full Text Available Ouvrage atypique par le fond comme par la forme, Le devoir et la grâce rend compte du minutieux travail d’élaboration théorique auquel s’attelle Cyril Lemieux depuis plusieurs années. Et le résultat final se veut pour le moins ambitieux : l’auteur propose un système total supposé dépasser d’un même élan le relativisme, le mentalisme, l’universalisme ethnocentrique, l’historicisme, le naturalisme et l’herméneutisme, tout en réconciliant les sciences sociales avec le ...

  12. Le sacre du printemps

    Directory of Open Access Journals (Sweden)

    Denise Pumain

    2002-03-01

    Full Text Available Cybergeo aura six ans en avril : dans la réalité du virtuel, dans l'univers récent et fluctuant de la publication en ligne, cela fait de nous, tout à la fois, des pionniers et des vétérans. De façon plus surprenante, il se trouve que nous sommes aussi uniques : parmi toutes les revues électroniques de sciences sociales, aucune ne combine comme Cybergeo ancienneté, publication exclusivement électronique, liberté d'accès au texte intégral, édition et gestion par des chercheurs, et comité de lec...

  13. Le Brahmane du Komintern

    Directory of Open Access Journals (Sweden)

    Elizabeth Burgos

    2008-01-01

    Full Text Available Le Brahmane du Komintern, largometraje documental del realizador francés Vladimir León, constituye un ejercicio ejemplar de investigación histórica y  de lograda factura de realización. Y, pese a no haber contado con la ayuda de ninguno organismo público, se trata de un ambicioso proyecto que cubre una amplia extensión geográfica que abarca: Estados Unidos, México, Moscú, Berlín, y la India. Gira en torno a una figura que tuvo en su tiempo su hora de gloria. Un bengalí, hijo de braman, la c...

  14. (Sorghum bicolor (L.) Moench) du Nord du Burkina Faso

    African Journals Online (AJOL)

    SARAH

    29 déc. 2014 ... sorghos à grains sucrés ont un cycle court et arrivent donc à maturité avant les autres sorghos et le mil d'où leur exploitation comme aliment de soudure par les paysans. L'organisation de la diversité morphologique des accessions de sorghos à grains sucrés du Nord du. Burkina autour principalement des ...

  15. 49 CFR 176.410 - Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Division 1.5 materials, ammonium nitrate and ammonium nitrate mixtures. 176.410 Section 176.410 Transportation Other Regulations Relating to... nitrate and ammonium nitrate mixtures. (a) This section prescribes requirements to be observed with...

  16. Interaction in triple systems of neodymium nitrate, water and nitrates of trimethylammonium and tetramethylammonium

    International Nuclear Information System (INIS)

    Boeva, M.K.; Zhuravlev, E.F.

    1977-01-01

    At 20 and 40 deg C the mutual solubility is studied in systems neodymium nitrate-water-trimethylamine nitrate and neodymium nitrate-water-tetramethylammonium nitrate. It has been established that the above systems belong to those with chemical interaction of the components. The compounds have been isolated preparatively, their composition has been confirmed analytically, and their thermal behaviour studied

  17. OPERATION DU FOISONNEMENT

    Directory of Open Access Journals (Sweden)

    Gholamreza Djelveh

    2010-04-01

    Full Text Available Mousses alimentaires sont un sous-ensemble des aliments connus sous le nom de produits fouettés ou des produits aérés. Ils sont des produits formulés avec des qualités telles que la légèreté et la souplesse et sont principalement consommés à l'apéritif ou au dessert. Les produits en mousse obtenue par dispersion d'un gaz dans une matrice alimentaire (la phase continue ont connu un développement croissant au cours des années 80 et 90. Le processus d'aération liés à leurs activités de production est appelée l'expansion ou à fouetter. Le document présente les principaux-paramètres du procédé du point permanent de la formulation, la mise en œuvre processus dans les installations pilotes et à l'échelle industrielle, la caractérisation des produits finis, la base énergétique de l'échelle de processus en place, et le lien entre la formulation, émulsion préparation de l'expansion. Cette vue d'ensemble de l'opération d'expansion continue, nous a permis de mettre en évidence le fait qu'il ya des opérations de l'unité encore mal décrite par le génie des procédés et pour lesquels les méthodes et outils pour l'extrapolation et la prédiction sont encore à leurs balbutiements.

  18. Alimentation du nouveau-ne et du nourrisson dans la region ...

    African Journals Online (AJOL)

    Alimentation du nouveau-ne et du nourrisson dans la region centrale du togo : pratiques familiales et communautaires avant la mise en oeuvre de la strategie « prise en charge integree des maladies de l'enfant »

  19. Method of producing thin cellulose nitrate film

    International Nuclear Information System (INIS)

    Lupica, S.B.

    1975-01-01

    An improved method for forming a thin nitrocellulose film of reproducible thickness is described. The film is a cellulose nitrate film, 10 to 20 microns in thickness, cast from a solution of cellulose nitrate in tetrahydrofuran, said solution containing from 7 to 15 percent, by weight, of dioctyl phthalate, said cellulose nitrate having a nitrogen content of from 10 to 13 percent

  20. 21 CFR 172.160 - Potassium nitrate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium nitrate. 172.160 Section 172.160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Preservatives § 172.160 Potassium nitrate. The food additive potassium nitrate may be safely used as a curing...

  1. Preparation of acid deficient solutions of uranyl nitrate and thorium nitrate by steam denitration

    International Nuclear Information System (INIS)

    Yamagishi, Shigeru; Takahashi, Yoshihisa

    1996-01-01

    Acid deficient heavy metal (HM) nitrate solutions are often required in the internal gelation processes for nuclear fuel fabrication. The stoichiometric HM-nitrate solutions are needed in a sol-gel process for fuel fabrication. A method for preparing such nitrate solutions with a controlled molar ratio of nitrate/metal by denitration of acid-excess nitrate solutions was developed. The denitration was conducted by bubbling a nitrate solution with a mixture of steam+Ar. It was found that steam was more effective for the denitration than Ar. The acid deficient uranyl nitrate solution with nitrate/U=1.55 was yielded by steam bubbling, while not by only Ar bubbling. As for thorium nitrate, acid deficient solutions of nitrate/Th≥3.1 were obtained by steam bubbling. (author)

  2. High temperature interaction studies on equimolar nitrate mixture of uranyl nitrate hexahydrate and gadolinium nitrate hexahydrate

    International Nuclear Information System (INIS)

    Kalekar, Bhupesh B.; Raje, Naina; Reddy, A.V.R.

    2015-01-01

    Rare earths including gadolinium form a sizeable fraction of the fission products in the nuclear fission of fissile material in the reactor. These fission products can interact with uranium dioxide fuel and can form various compounds which can alter the thermal behavior of the fuel. The mixed oxide formed due to the high temperature interactions of mixture of uranyl nitrate hexahydrate (UNH) and gadolinium nitrate hexahydrate (GdNH) has been studied using thermal and X- ray diffraction techniques. The equimolar mixture of UNH and GdNH was prepared by mixing the weighed amount of individual nitrates and grinding gently with mortar and pestle. Thermogravimetry (TG) measurements were carried out by separately heating 100 mg of mixture and individual nitrates at heating rate of 10°C min -1 using Netzsch thermal analyzer (Model No.: STA 409 PC Luxx) in high purity nitrogen atmosphere with a flow rate of 120 mL min -1 . The XRD measurement was carried out on a Philips X-ray diffractometer (Model PW1710) using nickel-filtered Cu-Kα radiation

  3. Plasma nitrate and nitrite are increased by a high nitrate supplement, but not by high nitrate foods in older adults

    Science.gov (United States)

    Miller, Gary D.; Marsh, Anthony P.; Dove, Robin W.; Beavers, Daniel; Presley, Tennille; Helms, Christine; Bechtold, Erika; King, S. Bruce; Kim-Shapiro, Daniel

    2012-01-01

    Little is known about the effect of dietary nitrate on the nitrate/nitrite/NO (nitric oxide) cycle in older adults. We examined the effect of a 3-day control diet vs. high nitrate diet, with and without a high nitrate supplement (beetroot juice), on plasma nitrate and nitrite kinetics, and blood pressure using a randomized four period cross-over controlled design. We hypothesized that the high nitrate diet would show higher levels of plasma nitrate/nitrite and blood pressure compared to the control diet, which would be potentiated by the supplement. Participants were eight normotensive older men and women (5 female, 3 male, 72.5±4.7 yrs) with no overt disease or medications that affect NO metabolism. Plasma nitrate and nitrite levels and blood pressure were measured prior to and hourly for 3 hours after each meal. The mean daily changes in plasma nitrate and nitrite were significantly different from baseline for both control diet+supplement (pnitrate and nitrite, respectively) and high nitrate diet+supplement (p=0.001 and 0.002), but not for control diet (p=0.713 and 0.741) or high nitrate diet (p=0.852 and 0.500). Blood pressure decreased from the morning baseline measure to the three 2 hr post-meal follow-up time-points for all treatments, but there was no main effect for treatment. In healthy older adults, a high nitrate supplement consumed at breakfast elevated plasma nitrate and nitrite levels throughout the day. This observation may have practical utility for the timing of intake of a nitrate supplement with physical activity for older adults with vascular dysfunction. PMID:22464802

  4. Nitrate Removal from Ground Water: A Review

    Directory of Open Access Journals (Sweden)

    Archna

    2012-01-01

    Full Text Available Nitrate contamination of ground water resources has increased in Asia, Europe, United States, and various other parts of the world. This trend has raised concern as nitrates cause methemoglobinemia and cancer. Several treatment processes can remove nitrates from water with varying degrees of efficiency, cost, and ease of operation. Available technical data, experience, and economics indicate that biological denitrification is more acceptable for nitrate removal than reverse osmosis and ion exchange. This paper reviews the developments in the field of nitrate removal processes which can be effectively used for denitrifying ground water as well as industrial water.

  5. Continuous flow nitration in miniaturized devices

    Directory of Open Access Journals (Sweden)

    Amol A. Kulkarni

    2014-02-01

    Full Text Available This review highlights the state of the art in the field of continuous flow nitration with miniaturized devices. Although nitration has been one of the oldest and most important unit reactions, the advent of miniaturized devices has paved the way for new opportunities to reconsider the conventional approach for exothermic and selectivity sensitive nitration reactions. Four different approaches to flow nitration with microreactors are presented herein and discussed in view of their advantages, limitations and applicability of the information towards scale-up. Selected recent patents that disclose scale-up methodologies for continuous flow nitration are also briefly reviewed.

  6. Le plurilinguisme du perroquet

    Directory of Open Access Journals (Sweden)

    Manuel Mühlbacher

    2012-05-01

    Full Text Available La figure du perroquet occupe une position ambiguë face à la question de la traduction. Il est capable d’imiter des paroles en toutes les langues, mais il n’est capable d’en comprendre aucune — il ne peut que répéter des sons, c’est-à-dire des signifiants. Le traducteur semble faire le contraire quand il passe d’une langue à une autre en tâchant de transmettre une signification semblable par d’autres signes. L’article vise à discuter le rôle du traducteur et sa relation, éventuellement équivoque, au perroquet, en analysant la traduction allemande de Trois Contes par André Stoll et Cora van Kleffens. Un décalage au niveau sémantique peut éclairer l’interprétation du texte, par exemple en explicitant des allusions sous-jacentes, tandis que le transfert de la syntaxe française en allemand pose souvent des problèmes considérables. Comment le traducteur peut-il reproduire des structures syntaxiques qui n’existent pas en allemand, mais qui ne cessent de revenir dans le texte français ? Que faire si le texte se met à jouer au perroquet et finit par se singer lui-même ? André Stoll et Cora van Kleffens ont su trouver des stratégies pour affronter ces difficultés.The figure of the parrot holds an ambiguous position towards the question of translation. It is able to imitate all languages, but it will never understand any of them – its only skill is to mimic sounds, i.e. mere signifiers. On the contrary, the translator seems to be the antithesis of the parrot when he moves from one language to another. He endeavours to convey a similar meaning, but by different signs. The article aims at discussing the role of the translator and his or her eventually equivocal relation to the parrot by means of analysing the German translation of Trois Contes by André Stoll and Cora van Kleffens. Whereas a semantic divergence can result in a different tendency on the level of interpretation, as in the case of an underlying

  7. Denitrification of nitrate waste solutions

    International Nuclear Information System (INIS)

    Michaels, S.L.; Michel, R.C.; Terpandjian, P.D.; Vora, J.N.

    1976-01-01

    Bacterial denitrification by Pseudomonas Stutzeri has been chosen as the method for removing nitrate from the effluent stream of the Y-12 uranium purification process. A model was developed to predict bacterial growth and carbon and nitrate depletion during the induction period and steady state operation. Modification of analytical procedures and automatic control of the pH in the reactor are recommended to improve agreement between the prediction of the model and experimental data. An initial carbon-to-nitrogen (C/N) mass ratio of 1.4-1.5 insures adequate population growth during the induction period. Further experiments in batch reactors and in steady state flow reactors are recommended to obtain more reliable kinetic rate constants

  8. 49 CFR 176.415 - Permit requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers.

    Science.gov (United States)

    2010-10-01

    ... nitrates, and certain ammonium nitrate fertilizers. 176.415 Section 176.415 Transportation Other... requirements for Division 1.5, ammonium nitrates, and certain ammonium nitrate fertilizers. (a) Except as... Captain of the Port (COTP). (1) Ammonium nitrate UN1942, ammonium nitrate fertilizers containing more than...

  9. Manurial properties of lead nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Berry, R A

    1924-01-01

    Water culture, pot and field experiments were conducted in order to determine the toxic and stimulating limit of lead nitrate in solution. Oats and rye grass were evaluated for evidence of lead poisoning. Results indicate that except in solutions of fairly high concentration, soil adsorbs the lead and destroys the toxicity of soluble lead salts. There was evidence to show that the addition of lead salts increased the rate of nitrification in soil.

  10. Nitration of sym-trichlorobenzene

    International Nuclear Information System (INIS)

    Quinlin, W.T.

    1981-02-01

    Basic thermal and kinetic data were obtained for the nitration of 1,3,5-trichlorobenzene to trichlorotrinitrobenzene in the presence of oleum/nitric acid. A limiting specific production rate of 5.4 kg/l/hr was determined for the addition of the first two nitro groups at 130 C and a rate of 0.16 kg/l/hr was obtained at 150 C for the addition of the third nitro group

  11. 2-Amino-5-chloropyridinium nitrate

    Directory of Open Access Journals (Sweden)

    Donia Zaouali Zgolli

    2009-11-01

    Full Text Available The title structure, C5H6ClN2+·NO3−, is held together by extensive hydrogen bonding between the NO3− ions and 2-amino-5-chloropyridinium H atoms. The cation–anion N—H...O hydrogen bonds link the ions into a zigzag- chain which develops parallel to the b axis. The structure may be compared with that of the related 2-amino-5-cyanopyridinium nitrate.

  12. Etat Du Magnesium Dans Quelques Sols Sales Du Sud Et Du ...

    African Journals Online (AJOL)

    étude a été réalisée sur 86 échantillons de sols provenant du Centre et du Sud de l´Irak. L\\'expérimentation a consisté, d´une part, à calculer les différents sels dominants dans les sols salés par la méthode de combinaison hypothétique et, ...

  13. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d\\'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

  14. Caractérisation des sables et morphologie du fond du lac du ...

    African Journals Online (AJOL)

    Administrateur

    Une analyse sédimentologique et minéralogique réalisée sur un cycle hydrologique entre octobre 2004 et août 2005 a permis d'évaluer les charges solides en suspension et de caractériser les sédiments du lac du barrage de Taabo. La concentration moyenne en matières en suspension (12 mg.L-1) et la turbidité ...

  15. Electrolytic production of uranous nitrate

    International Nuclear Information System (INIS)

    Orebaugh, E.G.; Propst, R.C.

    1980-04-01

    Efficient production of uranous nitrate is important in nuclear fuel reprocessing because U(IV) acts as a plutonium reductant in solvent extraction and can be coprecipitated with plutonium and/or throium as oxalates during fuel reprocessing. Experimental conditions are described for the efficient electrolytic production of uranous nitrate for use as a reductant in the SRP Purex process. The bench-scale, continuous-flow, electrolysis cell exhibits a current efficiency approaching 100% in combination with high conversion rates of U(VI) to U(IV) in simulated and actual SRP Purex solutions. High current efficiency is achieved with a voltage-controlled mercury-plated platinum electrode and the use of hydrazine as a nitrite scavenger. Conversion of U(VI) to U(IV) proceeds at 100% efficiency. Cathodic gas generation is minimal. The low rate of gas generation permits a long residence time within the cathode, a necessary condition for high conversions on a continuous basis. Design proposals are given for a plant-scale, continuous-flow unit to meet SRP production requirements. Results from the bench-scale tests indicate that an 8-kW unit can supply sufficient uranous nitrate reductant to meet the needs of the Purex process at SRP

  16. Photochemical reduction of uranyl nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Duerksen, W.K.

    1993-10-20

    The photochemical reduction of uranyl nitrate solutions to tetravalent uranium was investigated as a means of producing uranium dioxide feed for the saltless direct oxide reduction (SDOR) process. At high uranium concentrations, reoxidation of U{sup +4} occurs rapidly. The kinetics of the nitric oxidation of tetravalent uranium depend on the concentrations of hydrogen ion, nitrate ion, nitrous acid, and tetravalent uranium in the same manner as was reported elsewhere for the nitrate oxidation of PU{sup +3}. Reaction rate data were successfully correlated with a mechanism in which nitrogen dioxide is the reactive intermediate. Addition of a nitrous acid scavenger suppresses the reoxidation reaction. An immersion reactor employing a mercury vapor lamp gave reduction times fast enough for routine production usage. Precipitation techniques for conversion of aqueous U(NO{sub 3}){sub 4} to hydrous UO{sub 2} were evaluated. Prolonged dewatering times tended to make the process time consuming. Use of 3- to 4-M aqueous NaOH gave the best dewatering times observed. Reoxidation of the UO{sub 2} by water of hydration was encountered, which required the drying process to be carried out under a reducing atmosphere.

  17. Le bal du loup

    CERN Multimedia

    Happy Children's Home

    2013-01-01

    The Bord'eau amateur theatre group will graciously perform a play of their creation Le bal du loup Saturday 19 October 2013 at 20:00 Sunday 20 October at 17:00 in the Théâtre des Grottes Rue Louis Favre 43, 1201 Genève Children from age 12 upwards. Summary: The new-elected mayoress of a small village would like to clean up the town by prohibiting alcohol and getting rid of its prostitutes. Then along comes « Massimo Lupo » the pimp... The performances will be given to support the Happy Children's Home charity, which runs a foster-home in Pokhara for Nepali children:  http://www.happychildrenshome.org/ Admission : minimum charge of 10 CHF per person requested, to cover the cost of technical assistance and theatre rental. Any profit will be used solely for the foster-home. At the end of each performance members of the HCH charity will be happy to answer any questions you may have. The theatre has 86 seats, thank you for reserv...

  18. Aqueous-salt system containing ytterbium nitrate and pyridine nitrate

    International Nuclear Information System (INIS)

    Zhuravlev, E.F.; Khisaeva, D.A.; Izmajlova, L.V.

    1983-01-01

    Cross-section method has been used to study solubility in ternary aqueous-salt system Yb(NO 3 ) 3 -C 5 H 5 NxHNO 3 -H 2 0 at 25 and 50 deg C. It is established that the system is characterized by chemical interaction. Congruently soluble compound of Yb(NO 3 ) 3 x2[C 5 H 5 NxHNO 3 ] composition is discovered in the system. Composition of the compound is confirmed by chemical analysis; its infrared spectra are studied. Interplanar distances are determined; derivatogram of the compound is given. The results of the works are compared with analogous investigations of another rare earth nitrates

  19. Effets de la microdose sur la production du niébé, du mil et du ...

    African Journals Online (AJOL)

    Effets de la microdose sur la production du niébé, du mil et du sorgho en fonction la toposéquence. Fatimata Saba, Sibiri Jean Baptiste Taonda, Idriss Serme, Alimata A. Bandaogo, Augustin P. Sourwema, Adama Kabre ...

  20. Dynamique des populations du foreur des tiges du cacaoyer ...

    African Journals Online (AJOL)

    SARAH

    30 nov. 2014 ... déprédateur dans la région du Haut-Sassandra, la deuxième plus grande région de production de cacao en. Côte d'ivoire. Méthodologie et résultats : L'étude a été réalisée de 2009 à 2013 dans les plantations villageoises de la région du Haut-Sassandra en Côte d'Ivoire. Les variations des taux d'attaques ...

  1. Dynamique des populations du foreur des tiges du cacaoyer ...

    African Journals Online (AJOL)

    Objectif : Le foreur de tiges du cacaoyer, Eulophonotus myrmeleon Felder cause aujourd'hui d'énormes dégâts dans les cacaoyères ivoiriennes. La présente étude vise à déterminer les périodes de fortes attaques de ce déprédateur dans la région du Haut-Sassandra, la deuxième plus grande région de production de ...

  2. Gestion durable du paysage

    Directory of Open Access Journals (Sweden)

    Jean-David Gerber

    2009-03-01

    Full Text Available Le paysage est de plus en plus perçu comme une ressource. À ce titre, il est nécessaire de trouver des instruments juridiques, politiques ou économiques susceptibles de gérer cette « ressource-paysage » sur le long terme. Le gouvernement suisse a introduit récemment l’instrument des parcs naturels régionaux, organisés selon le modèle français, dans sa législation de protection de la nature et du paysage. Une mise en regard des nouveaux parcs avec des structures de gestion beaucoup plus anciennes, les bourgeoisies et les corporations, permet de mettre en évidence les forces et les faiblesses de chacun de ces instruments dans leur contribution à résoudre les rivalités d’usage entre acteurs utilisant ou influençant la ressource paysage. Cette comparaison permet de formuler des recommandations pratiques concernant la gestion de cette ressource.The landscape is increasingly perceived as a resource. For this reason, it is necessary to find legal, political and economic instruments that will succeed in managing this “resource landscape” in the long term. The Swiss government recently introduced the instrument of regional nature parks into the legislation governing nature and landscape preservation; the proposed parks are organized on the basis of the French model. The examination of the new parks from the perspective of much older management structures, i.e. the civic municipalities (bourgeoisies and corporations, makes it possible to demonstrate the strengths and weaknesses of each of these instruments in their contribution to the resolution of use rivalries between actors who use or influence the resource landscape. This comparison also enables the formulation of practical recommendations regarding the management of this resource.

  3. Nitrate contamination of groundwater and its countermeasures

    Energy Technology Data Exchange (ETDEWEB)

    Mitamura, Hisayoshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The inevitable increases of food production and energy consumption with an increase in world population become main causes of an increase of nitrate load to the environment. Although nitrogen is essential for the growth of animal and plant as a constituent element of protein, excessive nitrate load to the environment contaminates groundwater resources used as drinking water and leads to seriously adverse effects on the health of man and livestock. In order to clarify the problem of nitrate contamination of groundwater and search a new trend of technology development from the viewpoint of environment remediation and protection, the present paper has reviewed adverse effects of nitrate on human health, the actual state of nitrogen cycle, several kinds of nitrate sources, measures for reducing nitrate level, etc. (author)

  4. Le Developmental Entrepreneurship Program du Massachusetts ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Faire en sorte que les étudiants venant des pays en développement pour étudier au MIT retournent ensuite dans leurs pays respectifs afin d'y concrétiser leurs idées est un souci majeur du MIT, des bailleurs de fonds et du milieu du développement. Ce projet palliera à ce souci en soutenant la formation des fellows du ...

  5. Nitrates

    Science.gov (United States)

    ... Rounds Seminar Series & Daily Conferences Fellowships and Residencies School of Perfusion Technology Education Resources Library & Learning Resource Center CME Resources THI Journal THI Cardiac Society Register for the Cardiac Society ...

  6. Les dispositifs du Net art

    OpenAIRE

    Fourmentraux, Jean-Paul

    2010-01-01

    La pratique du Net art radicalise la question du potentiel communicationnel d’un média —Internet— qui constitue tout à la fois le support technique, l’outil créatif et le dispositif social de l’œuvre. Les technologies de l’information et de la communication (TIC) placent en effet l’œuvre d’art au cœur d’une négociation socialement distribuée entre l’artiste et le public. L’article est focalisé sur cette construction collective du Net art et sur ses mises en scènes. Il montre le travail artist...

  7. Nitrat i drikkevandet og vores sundhed

    DEFF Research Database (Denmark)

    Hansen, Birgitte; Schullehner, Jörg; Sigsgaard, Torben

    2014-01-01

    Nitrat i drikkevandet er uønsket, da det kan påvirke vores sundhed negativt. Den øvre grænse for hvor meget nitrat der tillades i drikkevandet er fastsat i forhold til risikoen for akut forgiftning med nitrit og blå børn-syndromet. Men nitrat i drikkevandet mistænkes også for at være medvirkende...

  8. Alpha autoradiography by cellulose nitrate layer

    International Nuclear Information System (INIS)

    Simonovic, J.; Vukovic, J.; Antanasijevic, R.

    1977-01-01

    From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artificial test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiography by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (Auth.)

  9. Alpha autoradiography by cellulose nitrate layer

    International Nuclear Information System (INIS)

    Simonovic, J.; Vukovic, J.; Antanasijevic, R.

    1976-01-01

    From domestic cellulose nitrate bulk material thin layers for α-particle autoradiography were prepared. An artifical test specimen of a uniformly alpha labelled grid source was used. The efficiency of autoradiographs by cellulose nitrate was calculated comparing with data from an Ilford K2 nuclear emulsion exposed under the same conditions as the cellulose nitrate film. The resolution was determined as the distance from grid pitch edge at which the track density fell considerably. (orig.) [de

  10. Inhaled plutonium nitrate in dogs

    International Nuclear Information System (INIS)

    Dagle, G.E.

    1987-01-01

    The major objective of this project is to determine dose-effect relationships of inhaled plutonium nitrate in dogs to aid in predicting health effects of accidental exposure in man. For lifespan dose-effect studies, beagle dogs were given a single inhalation exposure to 239 Pu(NO 3 ) 4 , in 1976 and 1977. The earliest biological effect was on the hematopoietic system; lymphopenia and neutropenia occurred at the two highest dose levels. They have also observed radiation pneumonitis, lung cancer, and bone cancer at the three highest dose levels. 1 figure, 3 tables

  11. Silver nitrate based gel dosimeter

    International Nuclear Information System (INIS)

    Titus, D; Samuel, E J J; Srinivasan, K; Roopan, S M; Madhu, C S

    2017-01-01

    A new radiochromic gel dosimeter based on silver nitrate and a normoxic gel dosimeter was investigated using UV-Visible spectrophotometry in the clinical dose range. Gamma radiation induced the synthesis of silver nanoparticles in the gel and is confirmed from the UV-Visible spectrum which shows an absorbance peak at around 450 nm. The dose response function of the dosimeter is found to be linear upto12Gy. In addition, the gel samples were found to be stable which were kept under refrigeration. (paper)

  12. Inhaled plutonium nitrate in dogs

    International Nuclear Information System (INIS)

    Dagle, G.E.

    1986-01-01

    The major objective of this project is to determine dose-effect relationships of inhaled plutonium nitrate in dogs to aid in predicting health effects of accidental exposure in man. For lifespan dose-effect studies, beagle dogs were given a single inhalation exposure to 239 Pu(NO 3 ) 4 , in 1976 and 1977. The earliest biological effect was on the hematopoietic system; lymphopenia and neutropenia occurred at the two highest dose levels. The authors have also observed radiation pneumonitis, lung cancer, and bone cancer at the three highest dose levels. 1 figure, 4 tables

  13. Inhaled plutonium nitrate in dogs

    International Nuclear Information System (INIS)

    Dagle, G.E.

    1982-01-01

    The major objective of this project is to determine dose-effect relationships of inhaled plutonium nitrate in dogs to aid in the prediction of health effects of accidental exposure in man. For lifespan dose-effect studies, beagle dogs were given a single inhalation exposure to 239 Pu(NO 3 ) 4 , in 1976 and 1977. The earliest biological effect was on the hematopoietic system; as described in previous Annual Reports, lymphopenia and neutropenia occurred at the two highest dose levels. Radiation pneumonitis, lung cancer, and bone cancer have been observed at the highest dose levels

  14. L'administration du travail et la production du droit du travail (1906-1960). : Note de synthèse du rapport de recherche

    OpenAIRE

    Le Crom , Jean-Pierre

    2007-01-01

    Synthèse d'un rapport de recherche dont l'objectif est d'appréhender le rôle de l'administration centrale du travail dans la production du droit du travail. Deux dimensions sont explorées : le profil des rédacteurs et l'organisation des structures.

  15. 76 FR 46907 - Ammonium Nitrate Security Program

    Science.gov (United States)

    2011-08-03

    ... Maritime Transportation Security Act NAICS North American Industrial Classification System NPRM Notice of.... Commenters noted, for example, that equipment used for transporting bulk ammonium nitrate, such as hoppers...

  16. Automated analysis for nitrate by hydrazine reduction

    Energy Technology Data Exchange (ETDEWEB)

    Kamphake, L J; Hannah, S A; Cohen, J M

    1967-01-01

    An automated procedure for the simultaneous determinations of nitrate and nitrite in water is presented. Nitrite initially present in the sample is determined by a conventional diazotization-coupling reaction. Nitrate in another portion of sample is quantitatively reduced with hydrazine sulfate to nitrite which is then determined by the same diazotization-coupling reaction. Subtracting the nitrite initially present in the sample from that after reduction yields nitrite equivalent to nitrate initially in the sample. The rate of analysis is 20 samples/hr. Applicable range of the described method is 0.05-10 mg/l nitrite or nitrate nitrogen; however, increased sensitivity can be obtained by suitable modifications.

  17. Negative feedback loops leading to nitrate homeostasis and oscillatory nitrate assimilation in plants and fungi.

    OpenAIRE

    Huang, Yongshun

    2011-01-01

    Master's thesis in Biological Chemistry Nitrate is an important nutrient for plants and fungi. For plants it has been shown that cytosolic nitrate levels are under homeostatic control. Here we describe two networks that can obtain robust, i.e. perturbation independent, homeostatic behavior in cytosolic nitrate concentration. One of the networks, a member in the family of outflow controllers, is based on a negative feedback loop containing a nitrate-induced activation of a controller molecu...

  18. Réflexion sur l’origine du processus de segmentation du marche du travail

    Directory of Open Access Journals (Sweden)

    Attia Nicole

    2006-01-01

    Full Text Available (francuski Ce travail propose une réflexion sur l'origine du processus de segmentation du marché du travail par rapport à l'entreprise. Se situe-t-elle au sein même de l'entreprise ou en amont, c'est à dire entre les entreprises? Cela revient à se demander si on peut avoir une approche microéconomique ou macroéconomique de la segmentation et, à s'interroger sur le rôle réel tenu par les firmes dans le processus. Déterminant pour la théorie, ce rôle est à repenser selon la réponse apportée à notre question.

  19. Challenges with nitrate therapy and nitrate tolerance: prevalence, prevention, and clinical relevance.

    Science.gov (United States)

    Thadani, Udho

    2014-08-01

    Nitrate therapy has been an effective treatment for ischemic heart disease for over 100 years. The anti-ischemic and exercise-promoting benefits of sublingually administered nitrates are well established. Nitroglycerin is indicated for the relief of an established attack of angina and for prophylactic use, but its effects are short lived. In an effort to increase the duration of beneficial effects, long-acting orally administered and topical applications of nitrates have been developed; however, following their continued or frequent daily use, patients soon develop tolerance to these long-acting nitrate preparations. Once tolerance develops, patients begin losing the protective effects of the long-acting nitrate therapy. By providing a nitrate-free interval, or declining nitrate levels at night, one can overcome or reduce the development of tolerance, but cannot provide 24-h anti-anginal and anti-ischemic protection. In addition, patients may be vulnerable to occurrence of rebound angina and myocardial ischemia during periods of absent nitrate levels at night and early hours of the morning, and worsening of exercise capacity prior to the morning dose of the medication. This has been a concern with nitroglycerin patches but not with oral formulations of isosorbide-5 mononitrates, and has not been adequately studied with isosorbide dinitrate. This paper describes problems associated with nitrate tolerance, reviews mechanisms by which nitrate tolerance and loss of efficacy develop, and presents strategies to avoid nitrate tolerance and maintain efficacy when using long-acting nitrate formulations.

  20. The influence of nitrate concentrations and acidity on the electrocatalytic reduction of nitrate on platinum

    NARCIS (Netherlands)

    Groot, de M.T.; Koper, M.T.M.

    2004-01-01

    A study was performed to determine the influence of nitrate concentration and acidity on the reaction rate and selectivity of the electrocatalytic nitrate reduction on platinum. There are two different nitrate reduction mechanisms on platinum: a direct mechanism (0.4–0.1 V vs. SHE) and an indirect

  1. Nitration Study of Cyclic Ladder Polyphenylsilsesquioxane

    Directory of Open Access Journals (Sweden)

    LIANG Jia-xiang

    2017-05-01

    Full Text Available Several nitration reagents including fuming nitric acid, HNO3-H2SO4, KNO3-H2SO4, HNO3-KNO3, CH3COOH-KNO3, (CH3CO2O-HNO3 were used to nitrate cyclic ladder polyphenylsilsesquioxane (CL-PPSQ in different conditions in order to enhance the compatibility of the CL-PPSQ in polymers, the NO2-PPSQ was obtained. FTIR, element analysis, GPC, TGA and 1H NMR were used to characterize the structures of the nitrated products. The results show that the nitrating abilities of the fuming nitric acid, HNO3-H2SO4 and KNO3-H2SO4 are very strong. Many nitro groups can be linked with phenyl groups in CL-PPSQ, but with low molecular mass, fracture occurs in siloxane segment. However, the Mn of the product NO2-PPSQ sharply drops by 50% compared with that of CL-PPSQ, so the nitration reagents can break the cyclic structure of CL-PPSQ. The nitrating reagents of HNO3-KNO3 and CH3COOH-KNO3 have no nitration effects on CL-PPSQ. At last, NO2-CL-PPSQ was prepared using (CH3CO2O-HNO3 because of the moderate nitration process and ability. The cyclic structure of PPSQ is remained, although the number of —NO2 group is not too much. At the same time, the nitration mechanism using different nitration reagents was analyzed. A certain amount of NO2+, which is a kind of activator owning strong nitration ability, can be found in the fuming nitric acid and H2SO4-HNO3(KNO3 systems. As to the (CH3CO2O-HNO3 system, the main activator is CH3COONO2.

  2. The systems terbium (holmium) nitrate-piperidine nitrate-water

    International Nuclear Information System (INIS)

    Khisaeva, D.A.; Zhuravlev, E.F.; Semenova, Eh.B.

    1982-01-01

    Using the method of cross sections at 25 and 50 deg C solubility in the systems Tb(NO 3 ) 2 -C 5 H 10 NHxHNO 3 -H 2 O and Ho(NO 3 ) 3 -C 5 H 10 NHxHNO 3 -H 2 O has been studied. The systems are characterized by chemical interaction of components. Solubility isotherms have crystallization fields of solid phases of the composition Tb(NO 3 ) 3 x3[C 5 H 10 NHxHNO 3 ]x3H 2 O and Ho(NO 3 ) 3 x2[C 5 H 10 NHxHNO 3 ]. The compounds detected are singled out preparatively, their IR spectra are studied, their thermogravimetric analysis is carried out. Investigation results are compared with similar systems formed by nitrates of other representatives of rare earth group

  3. Un Nouveau Monde du Savoir

    International Development Research Centre (IDRC) Digital Library (Canada)

    Si les effets de la mondialisation sur l'économie, la politique ou encore les ..... Il souligne l'importance cruciale d'un plan stratégique d'internationalisation, ...... Lors du recrutement de nouveaux professeurs ( lorsque cette situation est ...

  4. rive gauche du fleuve Rimac

    International Development Research Centre (IDRC) Digital Library (Canada)

    tégée du fleuve et les terrains vagues d'une zone industrielle. .... Ces deux diagnostics sont d'importants outils qui contri- bueront à une meilleure planification ... conditions et instruments nécessaires pour améliorer la situation financière des ...

  5. Voorwoord Forward | du Plessis | Lexikos

    African Journals Online (AJOL)

    J.CM.D. du Plessis. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions ...

  6. Charte du Conseil des Gouverneurs

    International Development Research Centre (IDRC) Digital Library (Canada)

    Office 2004 Test Drive User

    7. favoriser des communications ouvertes et franches entre le personnel, la direction ..... de dresser le procès-verbal des réunions du Conseil et de ses comités et de veiller à ce ... et des résultats qu'il obtient, et non de sa gestion quotidienne.

  7. Bases biologiques du comportement social

    CERN Document Server

    Laborit, H

    1994-01-01

    Pour bien comprendre le comportement humain dans un environnement social,il est necessaire de comprendre comment fonctionne le systÂ?me nerveux central. L'une des principales fonctions du cerveau est de crÂ?er des relations entre leshumains.. .................

  8. The crystal structure of urea nitrate

    NARCIS (Netherlands)

    Harkema, Sybolt; Feil, D.

    1969-01-01

    The structure of urea nitrate has been solved, by the use of three-dimensional X-ray data. Data were collected using Cu Ke and Mo K0~ radiations. The structure consists of layers with urea and nitrate groups held together by hydrogen bonds. The positions of all hydrogen atoms were found. The final R

  9. Spectrophotometric Determination of Nitrate in Vegetables Using ...

    African Journals Online (AJOL)

    DR. MIKE HORSFALL

    ABSTRACT: A rapid and sensitive spectrophotometric method for the determination of nitrate in vegetables is described. The method is based on the measurement of the absorbance of yellow sodium nitrophenoxide formed via the reaction of phenol with the vegetable-based nitrate in presence of sulphuric acid.

  10. NITRATE CONTAMINATION OF GROUND WATER (GW-761)

    Science.gov (United States)

    The occurrence of nitrate and related compounds in ground water is discussed from the perspectives of its natural as well as anthropogenic origins. A brief explanation of the nitrogen cycle touches on the production as well as utilization of ammonia, nitrite, nitrate, and nitrog...

  11. Nitrate metabolism in the gromiid microbial universe

    DEFF Research Database (Denmark)

    Høgslund, Signe; Risgaard-Petersen, Nils; Cedhagen, Tomas

    enclose and regulate a small biogeochemical universe within their cell. Their transparent proteinaceous cell wall surrounds a complex matrix consisting of sediment, bacteria and nitrate which is concentrated to hundreds of mM in the gromiid cell. The nitrate is respired to dinitrogen, but in contrast...

  12. 4-Methoxy-N,N′-diphenylbenzamidinium nitrate

    Directory of Open Access Journals (Sweden)

    Renata S. Silva

    2016-09-01

    Full Text Available The asymmetric unit of the title salt N,N′-diphenyl-4-methoxybenzamidinium nitrate, C20H19N2O+·NO3−, comprises two independent N,N′-diphenyl-4-methoxybenzamidinium cations and two nitrate anions. The crystal structure features N—H...O hydrogen bonds and C—H...O contacts responsible for the packing.

  13. Dietary nitrates, nitrites, and cardiovascular disease.

    Science.gov (United States)

    Hord, Norman G

    2011-12-01

    Dietary nitrate (NO(3)), nitrite (NO(2)), and arginine can serve as sources for production of NO(x) (a diverse group of metabolites including nitric oxide, nitrosothiols, and nitroalkenes) via ultraviolet light exposure to skin, mammalian nitrate/nitrite reductases in tissues, and nitric oxide synthase enzymes, respectively. NO(x) are responsible for the hypotensive, antiplatelet, and cytoprotective effects of dietary nitrates and nitrites. Current regulatory limits on nitrate intakes, based on concerns regarding potential risk of carcinogenicity and methemoglobinemia, are exceeded by normal daily intakes of single foods, such as soya milk and spinach, as well as by some recommended dietary patterns such as the Dietary Approaches to Stop Hypertension diet. This review includes a call for regulatory bodies to consider all available data on the beneficial physiologic roles of nitrate and nitrite in order to derive rational bases for dietary recommendations.

  14. Use of nitrates in ischemic heart disease.

    Science.gov (United States)

    Giuseppe, Cocco; Paul, Jerie; Hans-Ulrich, Iselin

    2015-01-01

    Short-acting nitrates are beneficial in acute myocardial ischemia. However, many unresolved questions remain about the use of long-acting nitrates in stable ischemic heart disease. The use of long-acting nitrates is weakened by the development of endothelial dysfunction and tolerance. Also, we currently ignore whether lower doses of transdermal nitroglycerin would be better than those presently used. Multivariate analysis data from large nonrandomized studies suggested that long-acting nitrates increase the incidence of acute coronary syndromes, while data from another multivariate study indicate that they have positive effects. Because of methodological differences and open questions, the two studies cannot be compared. A study in Japanese patients with vasospastic angina has shown that, when compared with calcium antagonists, long-acting nitrates do not improve long-term prognosis and that the risk for cardiac adverse events increases with the combined therapy. We have many unanswered questions.

  15. Nitrate reduction in an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Postma, Diederik Jan; Boesen, Carsten; Kristiansen, Henning

    1991-01-01

    of total dissolved ions in the NO3- free anoxic zone indicates the downward migration of contaminants and that active nitrate reduction is taking place. Nitrate is apparently reduced to N2 because both nitrite and ammonia are absent or found at very low concentrations. Possible electron donors......Nitrate distribution and reduction processes were investigated in an unconfined sandy aquifer of Quaternary age. Groundwater chemistry was studied in a series of eight multilevel samplers along a flow line, deriving water from both arable and forested land. Results show that plumes of nitrate...... processes of O2 and NO3- occur at rates that are fast compared to the rate of downward water transport. Nitrate-contaminated groundwater contains total contents of dissolved ions that are two to four times higher than in groundwater derived from the forested area. The persistence of the high content...

  16. Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(-)-myrtenol nitrate.

    Science.gov (United States)

    Bew, Sean P; Hiatt-Gipson, Glyn D; Mills, Graham P; Reeves, Claire E

    2016-01-01

    Here we report the chemoselective synthesis of several important, climate relevant isoprene nitrates using silver nitrate to mediate a 'halide for nitrate' substitution. Employing readily available starting materials, reagents and Horner-Wadsworth-Emmons chemistry the synthesis of easily separable, synthetically versatile 'key building blocks' (E)- and (Z)-3-methyl-4-chlorobut-2-en-1-ol as well as (E)- and (Z)-1-((2-methyl-4-bromobut-2-enyloxy)methyl)-4-methoxybenzene has been achieved using cheap, 'off the shelf' materials. Exploiting their reactivity we have studied their ability to undergo an 'allylic halide for allylic nitrate' substitution reaction which we demonstrate generates (E)- and (Z)-3-methyl-4-hydroxybut-2-enyl nitrate, and (E)- and (Z)-2-methyl-4-hydroxybut-2-enyl nitrates ('isoprene nitrates') in 66-80% overall yields. Using NOESY experiments the elucidation of the carbon-carbon double bond configuration within the purified isoprene nitrates has been established. Further exemplifying our 'halide for nitrate' substitution chemistry we outline the straightforward transformation of (1R,2S)-(-)-myrtenol bromide into the previously unknown monoterpene nitrate (1R,2S)-(-)-myrtenol nitrate.

  17. The systems lanthanum (cerium, samarium) nitrate-tetramethyl-ammonium nitrate-water

    International Nuclear Information System (INIS)

    Zhuravlev, E.F.; Khisaeva, D.A.; Semenova, Eh.B.

    1984-01-01

    The method of cross sections at 25 and 50 deg C has been applied to study solubility in the systems lanthanum nitrate-tetramethyl ammonium nitrate-water (1), cesium (3) nitrate-tetramethyl ammonium nitrate-water (2) and samarium nitrate-tetramethyl ammonium nitrate-water (3). Crystallization fields of congruently dissolving compounds with 1:3 ratio of salt components (in system 1) and 1:2 ratio (in systems 2 and 3) are found in the systems. New solid phases are separated preparatively and subjected to chemical, differential thermal and IR spectroscopic analyses. Compositions of formed compounds are compared with the compositions known for nitrates of other representatives of light lanthanides

  18. Phase diagram of ammonium nitrate

    International Nuclear Information System (INIS)

    Dunuwille, Mihindra; Yoo, Choong-Shik

    2013-01-01

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N 2 , N 2 O, and H 2 O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV ′ transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C

  19. Sodium nitrate combustion limit tests

    International Nuclear Information System (INIS)

    Beitel, G.A.

    1976-04-01

    Sodium nitrate is a powerful solid oxidant. Energetically, it is capable of exothermically oxidizing almost any organic material. Rate-controlling variables such as temperature, concentration of oxidant, concentration of fuel, thermal conductivity, moisture content, size, and pressure severely limit the possibility of a self-supported exothermic reaction (combustion). The tests reported in this document were conducted on one-gram samples at atmospheric pressure. Below 380 0 C, NaNO 3 was stable and did not support combustion. At moisture concentrations above 22 wt percent, exothermic reactions did not propagate in even the most energetic and reactive compositions. Fresh resin and paraffin were too volatile to enable a NaNO 2 -supported combustion process to propagate. Concentrations of NaNO 3 above 95 wt percent or below 35 wt percent did not react with enough energy release to support combustion. The influence of sample size and confining pressure, both important factors, was not investigated in this study

  20. Analytical methods used in plutonium purification cycles by trilaurylamine; Methodes analytiques utilisees dans les cycles de purification du plutonium par la trilaurylamine

    Energy Technology Data Exchange (ETDEWEB)

    Perez, J J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    The utilisation of trilaurylamine as a solvent extractant for the purification of plutonium has entailed to perfect a set of analytical methods which involves, various techniques. The organic impurities of the solvent can be titrated by gas-liquid chromatography. The titration of the main degradation product, the di-laurylamine, can be accomplished also by spectro-colorimetry. Potentiometry is used for the analysis of the different salts of amine-nitrate-sulfate-bisulfate as also the extracted nitric acid. The determination of the nitrate in aqueous phase is carried out by constant current potentiometry. The range of application, the accuracy and the procedure of these analysis are related in the present report. (author) [French] L'utilisation de la trilaurylamine comme solvant d'extraction pour la purification du plutonium a necessite la mise au point d'un ensemble de methodes analytiques qui ressortent de techniques diverses. Les impuretes organiques du solvant peuvent etre dosees par chromatographie gaz-liquide. Le dosage du principal produit de degradation, la dilaurylamine, peut egalement etre effectue par spectrocolorimetrie. La potentiometrie est utilisee pour les analyses des differents sels d'amine: nitrate, sulfate, bisulfate, ainsi que de l'acide nitrique extrait. La determination des nitrates en phase aqueuse est executee par potentiometrie a courant impose. Le domaine d'application, la precision et le mode operatoire de ces analyses sont indiques dans le present rapport. (auteur)

  1. Paul Celan in Translation: "Du sei wie du"

    Directory of Open Access Journals (Sweden)

    John Felstiner

    1983-09-01

    Full Text Available Translating the lyric poetry of Paul Celan, especially his later poems, carries not only the endemic challenge and difficulty of any verse translation, but the added incentive of doing justice to a writer whose whole recourse after the Holocaust—whose sanctuary, if he was to have any at all—he sought in language itself, specifically in the Muttersprache , the mother tongue that was as well the tongue of those who murdered his mother and father. This essay exposes a process of translating "Du sei wie du" (1970, which perhaps more than any other poem by Celan, at once solicits and defies translation, moving as it does from modern to medieval German, and closing with Hebrew words from Isaiah— a messianic imperative that shows Celan verging as ever on his Jewish identity.

  2. Le parcours migratoire de jeunes ruraux du bled du kif

    Directory of Open Access Journals (Sweden)

    Khalid Mouna

    2015-06-01

    Full Text Available Cet article analyse le parcours migratoire des jeunes ruraux originaires des zones de production du cannabis, jeunes qui cherchent à briser les chaînes de soumission et d’humiliation vécues au quotidien. Pour les jeunes concernés par notre étude, la migration constitue un moyen de s’intégrer dans des réseaux transnationaux et ainsi d’entamer une carrière de beznass (commerçant du cannabis. Ce parcours « initiatique » permet à ces jeunes de revenir au bled avec de nouvelles idées, des moyens accrus, et de jouer un rôle actif dans l’économie locale – qui reste pour eux focalisée sur la production de cannabis, cette dernière restant néanmoins officiellement interdite.

  3. Bassins versants du Loup, de la Cagne et du Malvan

    OpenAIRE

    Lepère, Cédric; Lautier, Laurence; Pellegrino, Emmanuel

    2013-01-01

    Identifiant de l'opération archéologique : 8453 Date de l'opération : 2007 (PC) ; 2007 (PI) Inventeur(s) : Lepère Cédric (AUT) ; Lautier Laurence (AUT) ; Pellegrino Emmanuel (AUT) Une campagne de prospection inventaire a été effectuée pendant trois mois, dans les bassins-versants de la Cagne, du Loup et du Malvan qui regroupent les communes de Cagnes-sur-Mer, Villeneuve-Loubet, La Colle-sur-Loup, Saint-Paul-de-Vence, Vence, Saint-Jeannet, Bezaudun, Tourrettes-sur-Loup, Roquefort-les-Pins, Le ...

  4. Marche du foncier urbain et promotion du logement au Benin ...

    African Journals Online (AJOL)

    Le marché du foncier urbain au Bénin est un secteur qui met en jeu l'intervention de plusieurs acteurs publics et privés mais également de l'informel. La notion de « foncier urbain » utilisée dans cet article englobe les acceptions et les utilisations faites en architecture, en urbanisme, en aménagement et en gestion urbaine.

  5. Gestion du parc agroforestier du terroir de Vipalogo (Burkina Faso ...

    African Journals Online (AJOL)

    Au Burkina Faso, l'arbre rural fait partie des systèmes de production. Le choix des espèces, leur densité, les modes de gestion ainsi que les besoins à satisfaire, obéissent à des critères propres aux producteurs. C'est pour comprendre ces logiques paysannes de la gestion du parc agroforestier que la présente étude a été ...

  6. Malformations du tube neural en chirurgie pediatrique du chu de ...

    African Journals Online (AJOL)

    encéphalocèle et 6 cas de sipina bifida. La cure chirurgicale a été le principal mode de prise en charge des patients. Seuls 91,38% des cas ont été opérés. Pour toutes les malformations du tube neural, nous avons enregistré 7 décès dont 2 décès ...

  7. CARBON-BASED REACTIVE BARRIER FOR NITRATE ...

    Science.gov (United States)

    Nitrate (NO3-) is a common ground water contaminant related to agricultural activity, waste water disposal, leachate from landfills, septic systems, and industrial processes. This study reports on the performance of a carbon-based permeable reactive barrier (PRB) that was constructed for in-situ bioremediation of a ground water nitrate plume caused by leakage from a swine CAFO (concentrated animal feeding operation) lagoon. The swine CAFO, located in Logan County, Oklahoma, was in operation from 1992-1999. The overall site remediation strategy includes an ammonia recovery trench to intercept ammonia-contaminated ground water and a hay straw PRB which is used to intercept a nitrate plume caused by nitrification of sorbed ammonia. The PRB extends approximately 260 m to intercept the nitrate plume. The depth of the trench averages 6 m and corresponds to the thickness of the surficial saturated zone; the width of the trench is 1.2 m. Detailed quarterly monitoring of the PRB began in March, 2004, about 1 year after construction activities ended. Nitrate concentrations hydraulically upgradient of the PRB have ranged from 23 to 77 mg/L N, from 0 to 3.2 mg/L N in the PRB, and from 0 to 65 mg/L N hydraulically downgradient of the PRB. Nitrate concentrations have generally decreased in downgradient locations with successive monitoring events. Mass balance considerations indicate that nitrate attenuation is dominantly from denitrification but with some component of

  8. Comparative evaluation of nitrate removal technologies

    International Nuclear Information System (INIS)

    Darbi, A.; Viraraghavan, T.; Butler, R.; Corkal, D.

    2002-01-01

    Due to the extensive application of artificial nitrogen-based fertilizers and animal manure on land, many water agencies face problems of increasing concentrations of nitrate in groundwater. The contamination of groundwater by nitrate may pose a significant public health problem. The threat of methemoglobinemia is well documented and reflected in the U.S. drinking water standard of 10 mg/L as nitrate-nitrogen. Approximately 45% of Saskatchewan's population use groundwater for drinking purposes, out of which, approximately 23% (230,000) are rural residents. The water used is made available from over 48,000 privately owned wells in regions where there is an extensive application of chemical fertilizers. Biological denitrification, ion exchange and reveres osmosis (RO) processes were selected for further study. Field studies were conducted on these processes. The sulfur/limestone autotrophic denitrification (SLAD) process was selected to achieve biological removal of nitrate from groundwater. The feasibility of the system was evaluated under anaerobic conditions. An ion exchange study was conducted using Ionac A554 which is strong anion exchange resins. In the case of groundwater containing low sulfate concentrations, A554 offered high nitrate removal. However, the disposal of regenerant brine can be a problem. A reverse osmosis unit with Filmtec membrane elements (FT30-Element Family) was used in the study on nitrate removal. The unit effluent average nitrate concentration was less than the maximum allowable concentration. (author)

  9. L’Harmonie du monde

    Directory of Open Access Journals (Sweden)

    Martine Clouzot

    2003-11-01

    Full Text Available La Bourgogne est particulièrement bien présente et représentée dans l’exposition sur la musique et ses représentations au Moyen Âge organisée par Isabelle Marchesin (université de Poitiers, Christine Laloue (conservatrice du Patrimoine au Musée et Martine Clouzot (université de Bourgogne, au Musée de la Musique à Paris du 26 mars au 27 juin 2004. En Côte-d’Or, à Dijon, la Bibliothèque municipale a donné son accord officiel pour le prêt de la Bible d’Etienne Harding, les Moralia in Job et u...

  10. Les vicissitudes du fret ferroviaire

    OpenAIRE

    DABLANC, L

    2010-01-01

    Dans beaucoup de pays européens, et plus encore en Amérique du Nord et en Asie, le transport de marchandises par le train a augmenté depuis dix ans. Cette activité réduit la part des marchandises acheminées par la route et contribue ainsi au développement durable : un camion émet 8 à 30 fois plus de dioxyde de carbone que le train, pour une distance et une quantité transportée équivalentes. Pourtant, la France a raté ce renouveau. Filiale du groupe public SNCF, la Société Fret SNCF, qui assur...

  11. Nitrate analogs as attractants for soybean cyst nematode.

    Science.gov (United States)

    Hosoi, Akito; Katsuyama, Tsutomu; Sasaki, Yasuyuki; Kondo, Tatsuhiko; Yajima, Shunsuke; Ito, Shinsaku

    2017-08-01

    Soybean cyst nematode (SCN) Heterodera glycines Ichinohe, a plant parasite, is one of the most serious pests of soybean. In this paper, we report that SCN is attracted to nitrate and its analogs. We performed attraction assays to screen for novel attractants for SCN and found that nitrates were attractants for SCN and SCN recognized nitrate gradients. However, attraction of SCN to nitrates was not observed on agar containing nitrate. To further elucidate the attraction mechanism in SCN, we performed attraction assays using nitrate analogs ([Formula: see text], [Formula: see text], [Formula: see text]). SCN was attracted to all nitrate analogs; however, attraction of SCN to nitrate analogs was not observed on agar containing nitrate. In contrast, SCN was attracted to azuki root, irrespective of presence or absence of nitrate in agar media. Our results suggest that the attraction mechanisms differ between plant-derived attractant and nitrate.

  12. Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, A.; Berger, D. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1965-07-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

  13. Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Fontaine, A; Berger, D [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1965-07-01

    The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

  14. L'energie du moustique

    CERN Document Server

    Augereau, J F

    2002-01-01

    ENSEMBLE DE QUATRE ARTICLES - LARGE HADRON COLLIDER: Le dernier accelerateur de particules du CERN, le LEP, produisait des faisceaux d'electrons de 100 GeV chacun. Le LHC, qui accelere des faisceaux de protons, leur communiquera une energie de 7 TeV chacun. Une energie a la fois colossale et derisoire. Un TeV represente a peu pres l'energie cinetique d'un moustique (1/2 page).

  15. Revision des Symphurus du Siboga

    NARCIS (Netherlands)

    Chabanaud, Paul

    1955-01-01

    Ce m’est un devoir particulièrement agréable que de saisir l’occasion de ce petit mémoire pour remercier M. L. F. DE BEAUFORT, M. H. ENGEL, Directeur du Zoologisch Museum, ainsi que M. J. J. HOEDEMAN de l’accueil qu’à diverses reprises, j’ai reçu de leur part, au Zoölogisch Museum, et aussi des

  16. Photodegradation of Paracetamol in Nitrate Solution

    Science.gov (United States)

    Meng, Cui; Qu, Ruijuan; Liang, Jinyan; Yang, Xi

    2010-11-01

    The photodegradation of paracetamol in nitrate solution under simulated solar irradiation has been investigated. The degradation rates were compared by varying environmental parameters including concentrations of nitrate ion, humic substance and pH values. The quantifications of paracetamol were conducted by HPLC method. The results demonstrate that the photodegradation of paracetamol followed first-order kinetics. The photoproducts and intermediates of paracetamol in the presence of nitrate ions were identified by extensive GC-MS method. The photodegradation pathways involving. OH radicals as reactive species were proposed.

  17. Photodegradation of Paracetamol in Nitrate Solution

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Meng; Ruijuan, Qu; Jinyan, Liang; Xi, Yang [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China)

    2010-11-24

    The photodegradation of paracetamol in nitrate solution under simulated solar irradiation has been investigated. The degradation rates were compared by varying environmental parameters including concentrations of nitrate ion, humic substance and pH values. The quantifications of paracetamol were conducted by HPLC method. The results demonstrate that the photodegradation of paracetamol followed first-order kinetics. The photoproducts and intermediates of paracetamol in the presence of nitrate ions were identified by extensive GC-MS method. The photodegradation pathways involving. OH radicals as reactive species were proposed.

  18. Photodegradation of Paracetamol in Nitrate Solution

    International Nuclear Information System (INIS)

    Meng Cui; Qu Ruijuan; Liang Jinyan; Yang Xi

    2010-01-01

    The photodegradation of paracetamol in nitrate solution under simulated solar irradiation has been investigated. The degradation rates were compared by varying environmental parameters including concentrations of nitrate ion, humic substance and pH values. The quantifications of paracetamol were conducted by HPLC method. The results demonstrate that the photodegradation of paracetamol followed first-order kinetics. The photoproducts and intermediates of paracetamol in the presence of nitrate ions were identified by extensive GC-MS method. The photodegradation pathways involving. OH radicals as reactive species were proposed.

  19. Actes des 5èmes Journées Scientifiques du GDR3544 Sciences du Bois. Journées Annuelles du GDR 3544 Sciences du Bois

    OpenAIRE

    CHAPLAIN, Myriam; CARE, Sabine; GRIL, Joseph

    2016-01-01

    Le Groupement de Recherche en Sciences du bois (GDR3544 Sciences du Bois) a été créé en 2012 par le CNRS et renouvelé en 2016 pour 5 ans. La mission de ce groupement est : (1) de structurer la recherche sur le bois en France pour lui donner une visibilité nationale, (2) de contribuer au développement de la formation en sciences du bois et (3) de servir de relai aux réseaux internationaux de sciences du bois. Les 5èmes journées annuelles du GDR Bois ont été organisées à Bordeaux, au domaine du...

  20. Original Paper Performances comparées du HDL-cholestérol et du ...

    African Journals Online (AJOL)

    CT/HDL-C) et du HDL-Cholestérol est le meilleur prédicteur du SMet chez les adultes béninois. .... (Canada) et du. Ministère de la Santé du Bénin. Le consentement éclairé écrit a été obtenu de chaque participant avant leur recrutement dans.

  1. 35 Typologie des eaux de surface du bassin du Sebou par multi ...

    African Journals Online (AJOL)

    PR BOKO

    2Service de protection de la qualité de l'eau, Agence du Bassin Hydraulique du ... pour montrer l'évolution de la qualité biologique des eaux de surface du ..... Biological Indicators of Freshwater Pollution and Environmental Management,.

  2. Régionalisation du recrutement du personnel de santé au Burkina ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Régionalisation du recrutement du personnel de santé au Burkina Faso ... le ministère a adopté une politique de recrutement régionalisé de certaines catégories du ... de comprendre le contexte dans lequel une telle stratégie a été formulée, ...

  3. Impact of Sulfide on Nitrate Conversion in Eutrophic Nitrate-Rich Marine Sludge

    DEFF Research Database (Denmark)

    Schwermer, Carsten U.; Krieger, Bärbel; Lavik, Gaute

    2006-01-01

    IMPACT OF SULFIDE ON NITRATE CONVERSION IN EUTROPHIC NITRATE-RICH MARINE SLUDGE C.U. Schwermer 1, B.U. Krieger 2, G. Lavik 1, A. Schramm 3, J. van Rijn 4, D. de Beer 1, D. Minz 5, E. Cytryn 4, M. Kuypers 1, A. Gieseke 1 1 Max Planck Institute for Marine Microbiology, Bremen, Germany; 2 Dept...... nitrate conversion from denitrification to dissimilatory nitrate-reduction to ammonium (DNRA). In situ microsensor profiling in stagnant sludge revealed the typical stratification of nitrate reduction on top of sulfate reduction. Increasing the bulk nitrate concentration lead to a downward shift....... Our results show that the presence of sulfide generally decreased growth rates but increased N2O production. We conclude that sulfide plays a key role in causing incomplete denitrification, presumably by inhibiting the N2O reductase, and enhancing DNRA compared to denitrification.  ...

  4. Nitrate removal from alkaline high nitrate effluent by in situ generation of hydrogen using zinc dust

    International Nuclear Information System (INIS)

    Rajagopal, S.; Chitra, S.; Paul, Biplob

    2016-01-01

    Alkaline radioactive low level waste generated in Nuclear Fuel Cycle contains substantial amount of nitrate and needs to be treated to meet Central Pollution Control Board discharge limits of 90 mg/L in marine coastal area. Several denitrification methods like chemical treatment, electrochemical reduction, biological denitrification, ion exchange, reverse osmosis, photochemical reduction etc are followed for removal of nitrate. In effluent treatment plants where chemical treatment is carried out, chemical denitrification can be easily adapted without any additional set up. Reducing agents like zinc and aluminum are suitable for reducing nitrate in alkaline solution. Study on denitrification with zinc dust was taken up in this work. Not much work has been done with zinc dust on reduction of nitrate to nitrogen in alkaline waste with high nitrate content. In the present work, nitrate is reduced by nascent hydrogen generated in situ, caused by reaction between zinc dust and sodium hydroxide

  5. Technical Report on Hydroxylamine Nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Harlow, Donald G. [Dept. of Energy (DOE), Washington DC (United States); Felt, Rowland E. [Dept. of Energy (DOE), Washington DC (United States); Agnew, Steve [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Barney, G. Scott [B& W Hanford Company, Richland, WA (United States); McKibben, J. Malvyn [Westinghouse Savannah River Company, Aiken, SC (United States); Garber, Robert [Parallax Inc., Rocklin, CA (United States); Lewis, Margie [Parallax Inc., Rocklin, CA (United States)

    1998-02-01

    This report presents the chemical properties and safe conditions for handling and storing solutions of hydroxylamine nitrate (HAN, NH2OH•HNO3 or NH3OH+) in nitric acid (HNO3). Section 1.0 summarizes the accidents experienced within the Department of Energy (DOE) weapons complex involving HAN or hydroxylamine sulfate (HAS), a chemical with similar properties. Section 2.0 describes past and current uses of HAN by DOE, the U.S. Military and foreign countries. Section 3.0 presents the basic chemistry of HAN, including chemical reaction and energy content equations. Section 4.0 provides experience and insights gained from previous uncontrolled reactions involving HAN and experimental data from Hanford & Savannah River Site (SRS). This information was used to develop safe conditions for the storage and handling of HAN as presented in Section 5.0. Section 6.0 summarizes recommendations for safe facility operations involving HAN and future research needs.

  6. Phase diagram of ammonium nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Dunuwille, Mihindra; Yoo, Choong-Shik, E-mail: csyoo@wsu.edu [Department of Chemistry and Institute for Shock Physics, Washington State University, Pullman, Washington 99164 (United States)

    2013-12-07

    Ammonium Nitrate (AN) is a fertilizer, yet becomes an explosive upon a small addition of chemical impurities. The origin of enhanced chemical sensitivity in impure AN (or AN mixtures) is not well understood, posing significant safety issues in using AN even today. To remedy the situation, we have carried out an extensive study to investigate the phase stability of AN and its mixtures with hexane (ANFO–AN mixed with fuel oil) and Aluminum (Ammonal) at high pressures and temperatures, using diamond anvil cells (DAC) and micro-Raman spectroscopy. The results indicate that pure AN decomposes to N{sub 2}, N{sub 2}O, and H{sub 2}O at the onset of the melt, whereas the mixtures, ANFO and Ammonal, decompose at substantially lower temperatures. The present results also confirm the recently proposed phase IV-IV{sup ′} transition above 17 GPa and provide new constraints for the melting and phase diagram of AN to 40 GPa and 400°C.

  7. Denitrification of nitrate waste solutions

    International Nuclear Information System (INIS)

    Bertolami, R.J.; Chao, E.I.; Choi, W.M.; Johnson, B.R.; Varlet, J.L.P.

    1976-01-01

    Growth rates for the denitrifying bacteria Pseudomonas Stutzeri were studied to minimize the time necessary to start up a bacterial denitrification reactor. Batch experiments were performed in nine 250-ml Erlenmeyer flasks, a 7-liter fermentor, and a 67-liter fermentor. All reactors maintained an anaerobic environment. Initial microorganism inoculum concentration was varied over four orders of magnitude. Initial nitrate and substrate carbon concentrations were varied from 200 to 6000 ppm and from 56 to 1596 ppm, respectively, with a carbon-to-nitrogen weight ratio of 1.18. In all experiments, except those with the highest initial substrate-to-bacteria ratio, no growth was observed due to substrate depletion during the lag period. In those experiments which did exhibit an increase in bacterial population, growth also stopped due to substrate depletion. A model simulating microbe growth during the induction period was developed, but insufficient data were available to properly adjust the model constants. Because of this, the model does not accurately predict microbe growth. The metabolism of Pseudomonas Stutzeri was studied in detail. This resulted in a prediction of the denitrification stoichiometry during steady state reactor operation. Iron was found to be an important component for bacterial anabolism

  8. La disparition du temps en gravitation quantique

    OpenAIRE

    Saint-Ours, Alexis de

    2012-01-01

    Le but de ce travail est d’examiner l’incidence philosophique de la gravitation quantique sur le concept de temps. Je cherche à montrer qu’elle conduit à une disparition du temps comme dimension et ouvre la voie à une compréhension du temps comme variation et même à l’idée de variation pure. En l’absence de temps mécanique, il est cependant possible de définir un temps d’origine thermodynamique. Je montre en quoi cette dissociation du temps mécanique et du temps thermodynamique, fait écho à l...

  9. Au fil du temps (1976 ou la loi du seuil

    Directory of Open Access Journals (Sweden)

    Isabelle Singer

    2010-04-01

    Full Text Available Ayant choisi de vivre dans un camion, les héros d’Au fil du temps (film de Wim Wenders de 1976 font du seuil une expérience particulière. Celle de la rupture avec toute idée de foyer et celle du refus d’appartenance à la terre natale, cette terre allemande traversée par une frontière le long de laquelle ils vont voyager, et qui les renvoie à chaque instant aux traumatismes de l’Histoire. Sur le pare-brise du camion, l’extérieur (campagnes indifférenciées, villes à l’abandon… et l’intérieur se superposent. Au fil du temps questionne le paysage : il s’agit d’en décoller un à un les mythes qui le recouvrent. L’image alors n’est plus surface mais volume à traverser, à lacérer et découvrir ce qui est tissé dans le paysage. La démarche de Wenders est alors proche de celle d’un de ses contemporains : Anselm Kiefer. Le paysage allemand provoque le rejet parce qu’il y a là toujours plus que le visible : des strates et des strates de culpabilité que le mythe - et c’est sa fonction - a recouvert. Et qu’il s’agira ici, de soulever. Le choix du nomadisme, c’est celui d’un état de l’humanité antérieur à l’idée de patrie. Et c’est aussi celui de la solitude, comme prix à payer à ce refus d’appartenance et à cette mise à jour des mythes. L’appartenance à la terre allemande et à son Histoire est profondément problématique parce que les pères sont fondamentalement coupables. On se reconnaîtra alors des pères de substitution : des pères de cinéma (Nicholas Ray ou Fritz Lang. Et l’on substituera l’Histoire du cinéma à l’Histoire. Bruno est réparateur ambulant de projecteurs et Au fil du temps dressera, au gré de ses pérégrinations, un état des lieux du cinéma allemand des années soixante-dix : déliquescent, colonisé par les images hollywoodiennes. Il faut que cela change : état du cinéma ; état des protagonistes solitaires en quête d’une identit

  10. Sodium nitrate-cerium nitrate-water ternary system at 25 deg C

    International Nuclear Information System (INIS)

    Fedorenko, T.P.; Onishchenko, M.K.

    1978-01-01

    Solubility isotherm of sodium nitrate-cerium nitrate-water system at 25 deg C consists of three crystallization branches of initial salts and double compound of the composition 2NaNO 3 xCe(NO 3 ) 3 x2H 2 O. Sodium nitrate introduced in the solution strengthens complexing. Physico-chemical characteristics are in a good agreement with solubility curve

  11. Dissimilatory nitrate reduction to nitrate, nitrous oxide, and ammonium by Pseudomonas putrefaciens.

    OpenAIRE

    Samuelsson, M O

    1985-01-01

    The influence of redox potential on dissimilatory nitrate reduction to ammonium was investigated on a marine bacterium, Pseudomonas putrefaciens. Nitrate was consumed (3.1 mmol liter-1), and ammonium was produced in cultures with glucose and without sodium thioglycolate. When sodium thioglycolate was added, nitrate was consumed at a lower rate (1.1 mmol liter-1), and no significant amounts of nitrite or ammonium were produced. No growth was detected in glucose media either with or without sod...

  12. Does thiosemicarbazide lead nitrate (TSLN) crystal exist?

    OpenAIRE

    Fernandes, R.; Srinivasan, Bikshandarkoil R.

    2016-01-01

    The authors of a recent paper (Optik 125 (2014) 2022-2025) claim to have grown a so called thiosemicarbazide lead nitrate (TSLN) crystal by the slow evaporation method. In this comment we prove that TSLN is actually thiosemicarbazide.

  13. Nitrate reduction in geologically heterogeneous catchments

    DEFF Research Database (Denmark)

    Refsgaard, Jens Christian; Auken, Esben; Bamberg, Charlotte A.

    2014-01-01

    In order to fulfil the requirements of the EU Water Framework Directive nitrate load from agricultural areas to surface water in Denmark needs to be reduced by about 40%. The regulations imposed until now have been uniform, i.e. the same restrictions for all areas independent of the subsurface...... conditions. Studies have shown that on a national basis about 2/3 of the nitrate leaching from the root zone is reduced naturally, through denitrification, in the subsurface before reaching the streams. Therefore, it is more cost-effective to identify robust areas, where nitrate leaching through the root...... the entire catchment. However, as distributed models often do not include local scale hydrogeological heterogeneities, they are typically not able to make accurate predictions at scales smaller than they are calibrated. We present a framework for assessing nitrate reduction in the subsurface...

  14. [Nitrate concentrations in tap water in Spain].

    Science.gov (United States)

    Vitoria, Isidro; Maraver, Francisco; Sánchez-Valverde, Félix; Armijo, Francisco

    2015-01-01

    To determine nitrate concentrations in drinking water in a sample of Spanish cities. We used ion chromatography to analyze the nitrate concentrations of public drinking water in 108 Spanish municipalities with more than 50,000 inhabitants (supplying 21,290,707 potential individuals). The samples were collected between January and April 2012. The total number of samples tested was 324. The median nitrate concentration was 3.47 mg/L (range: 0.38-66.76; interquartile range: 4.51). The water from 94% of the municipalities contained less than 15 mg/L. The concentration was higher than 25mg/L in only 3 municipalities and was greater than 50mg/L in one. Nitrate levels in most public drinking water supplies in municipalities inhabited by almost half of the Spanish population are below 15 mg/L. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

  15. Nitrate Waste Treatment Sampling and Analysis Plan

    Energy Technology Data Exchange (ETDEWEB)

    Vigil-Holterman, Luciana R. [Los Alamos National Laboratory; Martinez, Patrick Thomas [Los Alamos National Laboratory; Garcia, Terrence Kerwin [Los Alamos National Laboratory

    2017-07-05

    This plan is designed to outline the collection and analysis of nitrate salt-bearing waste samples required by the New Mexico Environment Department- Hazardous Waste Bureau in the Los Alamos National Laboratory (LANL) Hazardous Waste Facility Permit (Permit).

  16. High dose potassium-nitrate chemical dosimeter

    International Nuclear Information System (INIS)

    Dorda de Cancio, E.M.; Munoz, S.S.

    1982-01-01

    This dosimeter is used to control 10 kGY-order doses (1 Mrad). Nitrate suffers a radiolitic reduction phenomena, which is related to the given dose. The method to use potassium nitrate as dosimeter is described, as well as effects of the temperature of irradiation, pH, nitrate concentration and post-irradiation stability. Nitrate powder was irradiated at a Semi-Industrial Plant, at Centro Atomico Ezeiza, and also in a Gammacell-220 irradiator. The dose rates used were 2,60 and 1,80 KGY/hour, and the given doses varied between 1,0 and 150 KGY. The uncertainty was +-3% in all the range. (author) [es

  17. Effet de la nutrition minérale azotée sur le gain en biomasse de l'if du canada et sur le contenu en taxanes

    OpenAIRE

    Jollez, Pierre-Antoine

    2008-01-01

    Dans le cadre d'un vaste programme de domestication de l'if du Canada (Taxus canadensis Marsh.) à des fins de production de taxanes, de jeunes plants en première, deuxième ou troisième années de culture en contenants ont été soumis à différentes sources d'azote (nitrate d'ammonium, nitrate de calcium, nitrate de sodium, sulfate d'ammonium et urée), appliquées à différentes doses, et à divers pH du substrat pour étudier leur influence sur la croissance des plants, sur la teneur en éléments min...

  18. Ternary systems, consist of erbium nitrates, water and nitrates of pyridines, quinolines

    International Nuclear Information System (INIS)

    Starikova, L.I.; Zhuravlev, E.F.; Khalfina, L.R.

    1979-01-01

    At 25 and 50 deg C investigated is solubility of solid phases in ternary water salt systems: erbium nitrate-pyridine nitrate-water; erbium nitrate-quinoline nitrate-water. Formation of congruently soluble compounds of the Er(NO 3 ) 3 x2C 5 H 5 NxHNO 3 , Er(NO 3 ) 3 x2C 9 H 7 NxHNO 3 x4H 2 O composition is established. X-ray phase and thermogravimetric analyses have been carried out

  19. Data on nitrate and nitrate of Taham dam in Zanjan (Iran

    Directory of Open Access Journals (Sweden)

    Mohammadreza Massoudinejad

    2018-04-01

    Full Text Available In recent years, contamination of water resources, with pollutants such as nitrate and nitrite, has significantly increased. These compounds can have harmful effects on human health, especially children such as methemoglobinemia. The main objective of this study was to measure the concentration of nitrate and nitrite and its health-risk assessment in the rivers entering Taham dam in Zanjan. USEPA Method was used to assess the health-risk of nitrate and nitrite. According to the obtained results, the concentration of nitrate and nitrite was in the range of 0.51–14.93 mg/l and 0.001–0.061 mg/l, respectively. According to the results, the mean of the CDI for nitrate and nitrite was 9.52*10−2 and 3.63*10−4 mg/kg/day, respectively. Furthermore, the mean HI for nitrate and nitrite was 5.97*10−2 and 3.63*10−3, respectively. The concentration of nitrate and nitrite in rivers was lower than the WHO and Iran guidelines. Based on the results, the HI value in all samples was less than 1 which indicating the non-carcinogenic effects of nitrate and nitrite in these rivers. Keywords: Nitrate, Nitrite, Water quality, Dam

  20. Bio nitrate Project: a new technology for water nitrate elimination by means of ionic exchange resins

    International Nuclear Information System (INIS)

    Arellano Ortiz, J.

    2009-01-01

    The use of ion exchange resins for nitrate elimination from water generates a waste containing a sodium chloride mixture plus the retained nitrates. this waste must be correctly disposed. In this project, the resin ionic form is modified to be regenerated with other compounds, different from the common salt, which are interesting because of the presence of mineral nutrition. So, with Bio nitrate Project, nitrates are recovered and the regeneration waste is apt to be use as fertilizer, for agricultural uses, or as complementary contribution of nutrients in biological water treatment. (Author) 27 refs.

  1. Criticality parameters for uranyl nitrate or plutonium nitrate systems in tributyl phosphate/kerosine and water

    International Nuclear Information System (INIS)

    Weber, W.

    1985-01-01

    This report presents the calculated values of smallest critical masses and volumina and neutron physical parameters for uranyl nitrate (3, 4, 5% U-235) or plutonium nitrate (5% Pu-240), each in a 30 per cent solution of tributyl phosphate (TBP)/kerosine. For the corresponding nitrate-water solutions, newly calculated results are presented together with a revised solution density model. A comparison of the data shows to what extent the criticality of nitrate-TBP/kerosine systems can be assessed on the basis of nitrate-water parameters, revealing that such data can be applied to uranyl nitrate/water systems, taking into account that the smallest critical mass of uranyl nitrate-TBP/kerosine systems, up to a 5 p.c. U-235 enrichment, is by 4.5 p.c. at the most smaller than that of UNH-water solutions. Plutonium nitrate (5% Pu-240) in the TBP/kerosine solution will have a smallest critical mass of up to 7 p.c. smaller, as compared with the water data. The suitability of the computing methods and cross-sections used is verified by recalculating experiments carried out to determine the lowest critical enrichment of uranyl nitrate. The calculated results are well in agreement with experimental data. The lowest critical enrichment is calculated to be 2.10 p.c. in the isotope U-235. (orig.) [de

  2. Synthesis of a new energetic nitrate ester

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, David E [Los Alamos National Laboratory

    2008-01-01

    Nitrate esters have been known as useful energetic materials since the discovery of nitroglycerin by Ascanio Sobrero in 1846. The development of methods to increase the safety and utility of nitroglycerin by Alfred Nobel led to the revolutionary improvement in the utility of nitroglycerin in explosive applications in the form of dynamite. Since then, many nitrate esters have been prepared and incorporated into military applications such as double-based propellants, detonators and as energetic plasticizers. Nitrate esters have also been shown to have vasodilatory effects in humans and thus have been studied and used for treatments of ailments such as angina. The mechanism of the biological response towards nitrate esters has been elucidated recently. Interestingly, many of the nitrate esters used for military purposes are liquids (ethylene glycol dinitrate, propylene glycol dinitrate, etc). Pentaerythritol tetranitrate (PETN) is one of the only solid nitrate esters, besides nitrocellulose, that is used in any application. Unfortunately, PETN melting point is above 100 {sup o}C, and thus must be pressed as a solid for detonator applications. A more practical material would be a melt-castable explosive, for potential simplification of manufacturing processes. Herein we describe the synthesis of a new energetic nitrate ester (1) that is a solid at ambient temperatures, has a melting point of 85-86 {sup o}C and has the highest density of any known nitrate ester composed only of carbon, hydrogen, nitrogen and oxygen. We also describe the chemical, thermal and sensitivity properties of 1 as well as some preliminary explosive performance data.

  3. Studies in Aromatic and Amine Nitration.

    Science.gov (United States)

    1980-05-20

    of Commerce, May 1978. 4. J. Hoggett , R. Moodie, F. Penton, and K. Schofield, Nitration and Aromatic Reactivity (Cambridge University Press, 1971). 5...Moodie, K. Schofield, and G. Tobin, J. Chem. Soc., Chem. Comm., 180 (1978); (b) J. Hoggett , R. Moodie, and K. Schofield, Chem. Comm. 605 (1969). 10. (a) S...Lawrence Livermore Laboratories (Received, 5th Februaty 1980; Com. 124.) 42 ’(a) J. Hoggett , R. B. Moodie, J. R. Penton, and K. Schofield, in ’Nitration

  4. The dehydration of uranyl nitrate hexahydrate

    International Nuclear Information System (INIS)

    Badalov, A.; Kamalov, D.D.; Khamidov, B.O.; Mirsaidov, I.U.; Eshbekov, N.R.

    2010-01-01

    Present article is devoted to study of dehydration process of uranyl nitrate hexahydrate. The dehydration process of uranyl nitrate hexahydrate was studied by means of tensimeter method with membrane zero-manometer. The research was carried out under equilibrium conditions. It was defined that in studied temperature ranges (300-450 K) the dehydration process of UO_2(NO_3)_2 has a three stage character.

  5. The UK Nitrate Time Bomb (Invited)

    Science.gov (United States)

    Ward, R.; Wang, L.; Stuart, M.; Bloomfield, J.; Gooddy, D.; Lewis, M.; McKenzie, A.

    2013-12-01

    The developed world has benefitted enormously from the intensification of agriculture and the increased availability and use of synthetic fertilizers during the last century. However there has also been unintended adverse impact on the natural environment (water and ecosystems) with nitrate the most significant cause of water pollution and ecosystem damage . Many countries have introduced controls on nitrate, e.g. the European Union's Water Framework and Nitrate Directives, but despite this are continuing to see a serious decline in water quality. The purpose of our research is to investigate and quantify the importance of the unsaturated (vadose) zone pathway and groundwater in contributing to the decline. Understanding nutrient behaviour in the sub-surface environment and, in particular, the time lag between action and improvement is critical to effective management and remediation of nutrient pollution. A readily-transferable process-based model has been used to predict temporal loading of nitrate at the water table across the UK. A time-varying nitrate input function has been developed based on nitrate usage since 1925. Depth to the water table has been calculated from groundwater levels based on regional-scale observations in-filled by interpolated river base levels and vertical unsaturated zone velocities estimated from hydrogeological properties and mapping. The model has been validated using the results of more than 300 unsaturated zone nitrate profiles. Results show that for about 60% of the Chalk - the principal aquifer in the UK - peak nitrate input has yet to reach the water table and concentrations will continue to rise over the next 60 years. The implications are hugely significant especially where environmental objectives must be achieved in much shorter timescales. Current environmental and regulatory management strategies rarely take lag times into account and as a result will be poorly informed, leading to inappropriate controls and conflicts

  6. Systems of cerium(3) nitrate-dimethyl amine nitrate-water and cerium(3) nitrate-dimethyl amine nitrate-water

    International Nuclear Information System (INIS)

    Mininkov, N.E.; Zhuravlev, E.F.

    1976-01-01

    Solubility of solid phases in the systems cerium(3)nitrate-water-dimethyl amine nitrate and cerium(3)nitrate-water-dimethyl amine nitrate has been st ed by the method of isothermal sections at 25 and 50 deo. C. It has been shown that one anhydrous compound is formed in each system with a ratio of cerium(3) nitrate to amine nitrate 1:5. The compounds formed in the systems have been separated from the corresponding solutions and studied by microcrystalloscopic, X-ray phase, thermal and infrared spectroscopic methods. On the basis of spectroscopic studies the following formula has been assigned to the compound: [(CH 3 ) 2 NH 2 + ] 5 x[Ce(NO 3 ) 8 ]. The thermal analysis of the compound has shown that its melting point is 106 deg C. The solubility isotherms in the system Ce(NO 3 ) 3 -H 2 O-(C 2 H 5 ) 2 NHxHNO 3 consist of three branches which intersect in two eutonic points

  7. Nitrate Adsorption on Clay Kaolin: Batch Tests

    Directory of Open Access Journals (Sweden)

    Morteza Mohsenipour

    2015-01-01

    Full Text Available Soils possessing kaolin, gibbsite, goethite, and hematite particles have been found to have a natural capacity to attenuate pollution in aqueous phase. On the other hand, the hydroxyl group in soil increases anion exchange capacity under a low pH condition. The main objective of this paper was to evaluate effects of kaolin on nitrate reduction under acidic condition. In order to analyze the kaolin adsorption behaviour under various conditions, four different concentrations of nitrate, 45, 112.5, 225, and 450 mgNO3-/L, with a constant pH equal to 2, constant temperature equal to 25°C, and exposure period varying from 0 to 150 minutes were considered. The capacity of nitrate adsorption on kaolin has also been studied involving two well-known adsorption isotherm models, namely, Freundlich and Longmuir. The results revealed that approximately 25% of the nitrate present in the solution was adsorbed on clay kaolin. The laboratory experimental data revealed that Freundlich adsorption isotherm model was more accurate than Longmuir adsorption model in predicting of nitrate adsorption. Furthermore, the retardation factor of nitrate pollution in saturated zone has been found to be approximately 4 in presence of kaolin, which indicated that kaolin can be used for natural scavenger of pollution in the environment.

  8. Anaerobic columnar denitrification of high nitrate wastewater

    International Nuclear Information System (INIS)

    Francis, C.W.; Malone, C.D.

    1975-01-01

    Anaerobic columns were used to test the effectiveness of biological denitrification of nitrate solutions ranging in concentration from 1 to 10 kg NO 3 /m 3 . Several sources of nitrate (Ca(CNO 3 ) 2 , NaNO 3 , NH 4 NO 3 , and actual nitrate wastes from a UO 2 fuel fabrication plant) were evaluated as well as two packing media. The packing media were anthracite coal particles, whose effective diameter size ranged between 2 and 3 mm, and polypropylene Raschig rings 1.6 x 1.6 diameter. The anthracite coal proved to be the better packing media as excessive hydraulic short circuiting occurred in a 120 x 15 cm diameter glass column packed with the polypropylene rings after 40 days operation. With anthracite coal, floatation of the bed occurred at flow rates greater than 0.80 cm 3 /s. Tapered columns packed with anthracite coal eliminated the floatation problem, even at flow rates as high as 5 cm 3 /s. Under optimum operating conditions the anthracite coal behaved as a fluidized bed. Maximum denitrification rates were 1.0--1.4 g NO 3 /m 3 /s based on initial bed volume. Denitrification kinetics indicated that rates of denitrification became substrate inhibited at nitrate concentrations greater than 6.5 kg NO 3 /m 3 Anaerobic columns packed with anthracite coal appear to be an effective method of nitrate disposal for nitrate rich wastewater generated at UO 2 fuel fabrication plants and fuel reprocessing facilities. (U.S.)

  9. Protein tyrosine nitration in the cell cycle

    International Nuclear Information System (INIS)

    Jia, Min; Mateoiu, Claudia; Souchelnytskyi, Serhiy

    2011-01-01

    Highlights: → Enrichment of 3-nitrotyrosine containing proteins from cells synchronized in different phases of the cell cycle. → Identification of 76 tyrosine nitrated proteins that change expression during the cell cycle. → Nineteen identified proteins were previously described as regulators of cell proliferation. -- Abstract: Nitration of tyrosine residues in proteins is associated with cell response to oxidative/nitrosative stress. Tyrosine nitration is relatively low abundant post-translational modification that may affect protein functions. Little is known about the extent of protein tyrosine nitration in cells during progression through the cell cycle. Here we report identification of proteins enriched for tyrosine nitration in cells synchronized in G0/G1, S or G2/M phases of the cell cycle. We identified 27 proteins in cells synchronized in G0/G1 phase, 37 proteins in S phase synchronized cells, and 12 proteins related to G2/M phase. Nineteen of the identified proteins were previously described as regulators of cell proliferation. Thus, our data indicate which tyrosine nitrated proteins may affect regulation of the cell cycle.

  10. Investigation of complexing of trivalent lanthanoids in aqueous nitrate solutions

    International Nuclear Information System (INIS)

    Kopyrin, A.A.; Proyaev, V.V.; Edinakova, V.

    1985-01-01

    Complexing of trivalent lanthanoids (Ce, Eu) with nitrate-ions in concentrated solutions of lithium and sodium nitrates has been studied in a wide range of ionic forces (1.0-7.0), using the extractional, densimetric and solubility methods. Nitrate complexes registered by the extraction and solubility methods mainly are of second sphere character. During rare earth extraction from concentrated nitrate solutions in the range of nitrate-ion concentrations <= 5 mol/l second sphere neutral nitrate complexes take part in distribution, at higher values of nitrate-ion concentration formation of intrasphere monoligand complexes of lanthanoids should be taken into account

  11. Organic Nitrate Therapy, Nitrate Tolerance, and Nitrate-Induced Endothelial Dysfunction: Emphasis on Redox Biology and Oxidative Stress

    Science.gov (United States)

    2015-01-01

    Abstract Organic nitrates, such as nitroglycerin (GTN), isosorbide-5-mononitrate and isosorbide dinitrate, and pentaerithrityl tetranitrate (PETN), when given acutely, have potent vasodilator effects improving symptoms in patients with acute and chronic congestive heart failure, stable coronary artery disease, acute coronary syndromes, or arterial hypertension. The mechanisms underlying vasodilation include the release of •NO or a related compound in response to intracellular bioactivation (for GTN, the mitochondrial aldehyde dehydrogenase [ALDH-2]) and activation of the enzyme, soluble guanylyl cyclase. Increasing cyclic guanosine-3′,-5′-monophosphate (cGMP) levels lead to an activation of the cGMP-dependent kinase I, thereby causing the relaxation of the vascular smooth muscle by decreasing intracellular calcium concentrations. The hemodynamic and anti-ischemic effects of organic nitrates are rapidly lost upon long-term (low-dose) administration due to the rapid development of tolerance and endothelial dysfunction, which is in most cases linked to increased intracellular oxidative stress. Enzymatic sources of reactive oxygen species under nitrate therapy include mitochondria, NADPH oxidases, and an uncoupled •NO synthase. Acute high-dose challenges with organic nitrates cause a similar loss of potency (tachyphylaxis), but with distinct pathomechanism. The differences among organic nitrates are highlighted regarding their potency to induce oxidative stress and subsequent tolerance and endothelial dysfunction. We also address pleiotropic effects of organic nitrates, for example, their capacity to stimulate antioxidant pathways like those demonstrated for PETN, all of which may prevent adverse effects in response to long-term therapy. Based on these considerations, we will discuss and present some preclinical data on how the nitrate of the future should be designed. Antioxid. Redox Signal. 23, 899–942. PMID:26261901

  12. Organic Nitrate Therapy, Nitrate Tolerance, and Nitrate-Induced Endothelial Dysfunction: Emphasis on Redox Biology and Oxidative Stress.

    Science.gov (United States)

    Daiber, Andreas; Münzel, Thomas

    2015-10-10

    Organic nitrates, such as nitroglycerin (GTN), isosorbide-5-mononitrate and isosorbide dinitrate, and pentaerithrityl tetranitrate (PETN), when given acutely, have potent vasodilator effects improving symptoms in patients with acute and chronic congestive heart failure, stable coronary artery disease, acute coronary syndromes, or arterial hypertension. The mechanisms underlying vasodilation include the release of •NO or a related compound in response to intracellular bioactivation (for GTN, the mitochondrial aldehyde dehydrogenase [ALDH-2]) and activation of the enzyme, soluble guanylyl cyclase. Increasing cyclic guanosine-3',-5'-monophosphate (cGMP) levels lead to an activation of the cGMP-dependent kinase I, thereby causing the relaxation of the vascular smooth muscle by decreasing intracellular calcium concentrations. The hemodynamic and anti-ischemic effects of organic nitrates are rapidly lost upon long-term (low-dose) administration due to the rapid development of tolerance and endothelial dysfunction, which is in most cases linked to increased intracellular oxidative stress. Enzymatic sources of reactive oxygen species under nitrate therapy include mitochondria, NADPH oxidases, and an uncoupled •NO synthase. Acute high-dose challenges with organic nitrates cause a similar loss of potency (tachyphylaxis), but with distinct pathomechanism. The differences among organic nitrates are highlighted regarding their potency to induce oxidative stress and subsequent tolerance and endothelial dysfunction. We also address pleiotropic effects of organic nitrates, for example, their capacity to stimulate antioxidant pathways like those demonstrated for PETN, all of which may prevent adverse effects in response to long-term therapy. Based on these considerations, we will discuss and present some preclinical data on how the nitrate of the future should be designed.

  13. Contribution to the study of the vertical molten zone process (1963); Contribution a l'etude du procede de la zone fondue verticale (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Lenzin, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    Construction and use of several molten zone apparatuses operating either vertically or horizontally. Efficient purification of uranyl nitrate hexahydrate but less successful in the case of other hydrated double salts and of zirconyl chloride in the hydrochloric gel form. Demonstration and study of the dissymmetry in the direction of the transport of the impurity during, the purification by a vertical molten zone process. (author) [French] Construction et utilisation de plusieurs appareils de zone fondue travaillant soit en vertical, soit en horizontal. Purification efficace du nitrate d'uranyle hexahydrate mais peu significative dans le cas des autres couples de sels hydrates et du chlorure de zirconyle a l'etat de gel chlorhydrique. Mise en evidence et etude de la dissymetrie sur le sens de transport de l'impurete au cours de la purification par zone fondue verticale. (auteur)

  14. Radiation-induced nitration of organic compounds in aqueous solutions

    International Nuclear Information System (INIS)

    Ershov, B.G.; Gordeev, A.V.; Bykov, G.L.; Moisy, P.

    2012-01-01

    Radiolysis in aqueous nitrate and acetic acid solutions and nitrate/nitric acid and phenol was studied. The radiolysis of these solutes occurs with circle NO 2 radical, which is the active nitrating agent. Accumulation of nitromethane and nitrite was determined during γ-irradiation of aqueous solutions containing acetic and nitrate solutions. Irradiation of aqueous phenol-nitrate/nitric acid solutions results in the formation of 2- and 4-nitrophenols.

  15. Radiation-induced nitration of organic compounds in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Ershov, B.G.; Gordeev, A.V.; Bykov, G.L. [Russian Academy of Sciences, Moscow (Russian Federation). Frumkin Inst. of Physical Chemistry and Electrochemistry; Moisy, P. [CEA, Bagnols sur Ceze (France). Nuclear Energy Div.

    2012-07-01

    Radiolysis in aqueous nitrate and acetic acid solutions and nitrate/nitric acid and phenol was studied. The radiolysis of these solutes occurs with {sup circle} NO{sup 2} radical, which is the active nitrating agent. Accumulation of nitromethane and nitrite was determined during {gamma}-irradiation of aqueous solutions containing acetic and nitrate solutions. Irradiation of aqueous phenol-nitrate/nitric acid solutions results in the formation of 2- and 4-nitrophenols.

  16. Oxygen regulation of nitrate uptake in denitrifying Pseudomonas aeruginosa.

    OpenAIRE

    Hernandez, D; Rowe, J J

    1987-01-01

    Oxygen had an immediate and reversible inhibitory effect on nitrate respiration by denitrifying cultures of Pseudomonas aeruginosa. Inhibition of nitrate utilization by oxygen appeared to be at the level of nitrate uptake, since nitrate reduction to nitrite in cell extracts was not affected by oxygen. The degree of oxygen inhibition was dependent on the concentration of oxygen, and increasing nitrate concentrations could not overcome the inhibition. The inhibitory effect of oxygen was maximal...

  17. Formation, Evaporation, and Hydrolysis of Organic Nitrates from Nitrate Radical Oxidation of Monoterpenes

    Science.gov (United States)

    Ng, N. L.; Takeuchi, M.; Eris, G.; Berkemeier, T.; Boyd, C.; Nah, T.; Xu, L.

    2017-12-01

    Organic nitrates play an important role in the cycling of NOx and secondary organic aerosol (SOA) formation, yet their formation mechanisms and fates remain highly uncertain. The interactions of biogenic VOCs with NO3 radicals represent a direct way for positively linking anthropogenic and biogenic emissions. Results from ambient studies suggest that organic nitrates have a relatively short lifetime, though corresponding laboratory data are limited. SOA and organic nitrates produced at night may evaporate the following morning due to increasing temperatures or dilution of semi-volatile compounds. Once formed, organic nitrates can also undergo hydrolysis in the presence of particle water. In this work, we investigate the formation, evaporation, and hydrolysis of organic nitrates generated from the nitrate radical oxidation of a-pinene, b-pinene, and limonene. Experiments are conducted in the Georgia Environmental Chamber facility (GTEC) under dry and humid conditions and different temperatures. Experiments are also designed to probe different peroxy radical pathways (RO2+HO2 vs RO2+NO3). Speciated gas-phase and particle-phase organic nitrates are continuously monitored by a Filter Inlet for Gases and AEROsols High Resolution Time-of-Flight Chemical Ionization Mass Spectrometer (FIGAERO-HR-ToF-CIMS). Bulk aerosol composition is measured by a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS). A large suite of highly oxygenated gas- and particle-phase organic nitrates are formed rapidly. We find a resistance to aerosol evaporation when it is heated. The extent of organic nitrate hydrolysis in the humid experiments is evaluated. The dynamics of the speciated organic nitrates over the course of the experiments will also be discussed. Results from this chamber study provide fundamental data for understanding the dynamics of organic nitrate aerosols over its atmospheric lifetime.

  18. Le vide univers du tout et du rien

    CERN Document Server

    Diner, Simon

    1997-01-01

    Pourquoi l'Univers plutôt que le vide ? Le temps et l'espace existent-ils en l'absence de l'Univers ? Que reste-t-il quand tout est enlevé ? Pourquoi quelque chose plutôt que rien ? Depuis des siècles, ces interrogations mobilisent philosophes et physiciens. Mais aujourd'hui, le vide n'est pas le rien. Il serait même l'acteur central de l'histoire de la matière et de l'Univers, le partenaire privilégié de la physique. Vide et matière ne sont plus deux manifestations séparées de la nature, mais deux aspects d'une même réalité. Le vide est l'état de base dont la matière émerge, sans couper son cordon ombilical Le vide comme Univers du rien cède la place au vide comme Univers du tout. Que le vide puisse être conçu par les physiciens comme réservoir potentiel d'univers, voici qui ne devrait laisser personne indifférent. Ce livre ouvre un débat et nous convie à une réflexion surprenante.

  19. Image du savoir, image du pouvoir dans le Lapidaire

    Directory of Open Access Journals (Sweden)

    Marta LACOMBA

    2007-01-01

    Full Text Available À travers le prologue et les enluminures de présentation, le Lapidaire d’Alphonse X oriente l’interprétation de l’œuvre. Ces paratextes mettent en avant le rôle capital du savoir, représenté par la métaphore du trésor caché, qui a ici une valeur topique. Ils mettent également en exergue le rôle que s’attribue le roi dans la transmission de ce savoir, et placent cette nouvelle attribution royale au cœur de son projet politique.A través del prólogo y las miniaturas de presentación, el Lapidario de Alfonso X orienta la interpretación de la obra. Estos paratextos subrayan el papel capital del saber, representado por la metáfora del tesoro escondido, que tiene aquí un valor tópico. Ponen asimismo de manifiesto el papel que se atribuye el monarca en la transmisión de ese saber y colocan esta nueva atribución real en el centro de su proyecto político.

  20. Main: 1DU5 [RPSD[Archive

    Lifescience Database Archive (English)

    Full Text Available 1DU5 トウモロコシ Corn Zea mays L. Zeamatin Precursor. Name=Zlp; Zea Mays Molecule: Zeamatin; Chai...eta Sandwich SWS:ZEAM_MAIZE,P33679|EMBL; U06831; AAA92882.1; -.|PIR; T02075; T02075.|PDB; 1DU5; X-ray; A/B=22-227.|Mai

  1. les cahiers du cread: About this journal

    African Journals Online (AJOL)

    les cahiers du cread: About this journal. Journal Home > les cahiers du cread: About this journal. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register · Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives. People. » Contact. Policies.

  2. Les figures multiples du maire.

    Directory of Open Access Journals (Sweden)

    Olivier Lebraud

    2004-06-01

    Full Text Available Alors même que l’ensemble du personnel gouvernemental et parlementaire est sujet à une relative désaffection de la part des citoyens, les maires français jouissent, on le sait, d’une popularité qui fait d’eux les figures centrales de la scène politique. Au-delà de la décentralisation, qui a souvent renforcé leur image de décideurs, ils ont su tirer parti de la dimension identitaire qui caractérise l’échelon communal pour devenir les acteurs indispensables de la vie locale. ...

  3. Vers une anthropologie du Confucianisme

    OpenAIRE

    Rieu , Alain-Marc

    2010-01-01

    Research in Anthropology developed in France by Jean-Pierre Vernant, Marcel Détienne and Philippe Descola opens the possibility to reframe the debate and research on the function of Confucianism in Chinese culture, history and society. This paper shows how Confucianism can be studied as a "mythology"; La fonction du Confucianisme dans l'histoire de la société et de la culture chinoise, les débats et les reconstructions dont il est l'objet et l'enjeu, ouvre la possibilité de l'étudier d'un poi...

  4. Session du Conseil du CERN : le ministre britannique, Robert Jackson, souligne l'intérêt de on pays pour l'avenir du CERN : décisions du Conseil pour la mise en oeuvre des recommandations du Comité d'évaluation du CERN: départ anticipé pour 200 membres au moins du personnel - mise à jour de la méthode de calcule pour les contributions des Etats Membres au budget

    CERN Multimedia

    CERN Press Office. Geneva

    1988-01-01

    Session du Conseil du CERN : le ministre britannique, Robert Jackson, souligne l'intérêt de on pays pour l'avenir du CERN : décisions du Conseil pour la mise en oeuvre des recommandations du Comité d'évaluation du CERN: départ anticipé pour 200 membres au moins du personnel - mise à jour de la méthode de calcule pour les contributions des Etats Membres au budget

  5. Nitration of naphthalene and remarks on the mechanism of electrophilic aromatic nitration*

    Science.gov (United States)

    Olah, George A.; Narang, Subhash C.; Olah, Judith A.

    1981-01-01

    Naphthalene was nitrated with a variety of nitrating agents. Comparison of data with Perrin's electrochemical nitration [Perrin, C. L. (1977) J. Am. Chem. Soc. 99, 5516-5518] shows that nitration of naphthalene gives an α-nitronaphthalene to β-nitronaphthalene ratio that varies between 9 and 29 and is thus not constant. Perrin's data, therefore, are considered to be inconclusive evidence for the proposed one-electron transfer mechanism for the nitration of naphthalene and other reactive aromatics. Moodie and Schoefield [Hoggett, J. G., Moodie, R. B., Penton, J. R. & Schoefield, K. (1971) Nitration and Aromatic Reactivity (Cambridge Univ. Press, London)], as well as Perrin, independently concluded that, in the general scheme of nitration of reactive aromatics, there is the necessity to introduce into the classical Ingold mechanism an additional step involving a distinct intermediate preceding the formation of the Wheland intermediate (σ complexes). This view coincides with our two-step mechanistic picture [Kuhn, S. J. & Olah, G. A. (1961) J. Am. Chem. Soc. 83, 4564-4571] of the nitronium salt nitration of aromatic hydrocarbons (including benzene and toluene), in which low substrate selectivity but high positional selectivity was found, indicating the independence of substrate from positional selectivity. PMID:16593026

  6. Nitration of naphthalene and remarks on the mechanism of electrophilic aromatic nitration.

    Science.gov (United States)

    Olah, G A; Narang, S C; Olah, J A

    1981-06-01

    Naphthalene was nitrated with a variety of nitrating agents. Comparison of data with Perrin's electrochemical nitration [Perrin, C. L. (1977) J. Am. Chem. Soc. 99, 5516-5518] shows that nitration of naphthalene gives an alpha-nitronaphthalene to beta-nitronaphthalene ratio that varies between 9 and 29 and is thus not constant. Perrin's data, therefore, are considered to be inconclusive evidence for the proposed one-electron transfer mechanism for the nitration of naphthalene and other reactive aromatics. Moodie and Schoefield [Hoggett, J. G., Moodie, R. B., Penton, J. R. & Schoefield, K. (1971) Nitration and Aromatic Reactivity (Cambridge Univ. Press, London)], as well as Perrin, independently concluded that, in the general scheme of nitration of reactive aromatics, there is the necessity to introduce into the classical Ingold mechanism an additional step involving a distinct intermediate preceding the formation of the Wheland intermediate (sigma complexes). This view coincides with our two-step mechanistic picture [Kuhn, S. J. & Olah, G. A. (1961) J. Am. Chem. Soc. 83, 4564-4571] of the nitronium salt nitration of aromatic hydrocarbons (including benzene and toluene), in which low substrate selectivity but high positional selectivity was found, indicating the independence of substrate from positional selectivity.

  7. The systems cerium(3) (samarium) nitrate-quinoline nitrate-water

    International Nuclear Information System (INIS)

    Khisaeva, D.A.; Zhuravlev, E.F.; Semenova, Eh.B.

    1982-01-01

    Using the method of cross sections at 25 and 50 deg C the solubility in the systems cerium (3) nitrate-quinoline nitrate-water and samarium nitrate-quinoline nitrate-water has been studied. It is established that in the systems during chemical interaction of components congruently melting compounds of the composition: Ce(NO 3 ) 2 x2[C 9 H 7 NxHNO 3 ]x6H 2 O and Sm(NO 3 ) 3 x2[C 9 H 7 NxHNO 3 ]x2H 2 O are formed. New solid phases are separated preparatively and are subjected to chemical, differential thermal and IR spectroscopic analyses. The investigation results are compared with similar ones for nitrates of other representatives of lanthanide group

  8. Bases en technique du vide

    CERN Document Server

    Rommel, Guy

    2017-01-01

    Cette seconde édition, 20 ans après la première, devrait continuer à aider les techniciens pour la réalisation de leur système de vide. La technologie du vide est utilisée, à présent, dans de nombreux domaines très différents les uns des autres et avec des matériels très fiables. Or, elle est souvent bien peu étudiée, de plus, c'est une discipline où le savoir-faire prend tout son sens. Malheureusement la transmission par des ingénieurs et techniciens expérimentés ne se fait plus ou trop rapidement. La technologie du vide fait appel à la physique, à la chimie, à la mécanique, à la métallurgie, au dessin industriel, à l'électronique, à la thermique, etc. Cette discipline demande donc de maîtriser des techniques de domaines très divers, et ce n'est pas chose facile. Chaque installation est en soi un cas particulier avec ses besoins, sa façon de traiter les matériaux et celle d'utiliser les matériels. Les systèmes de vide sont parfois copiés d'un laboratoire à un autre et le...

  9. Effect of ammonium and nitrate on ferric chelate reductase and nitrate reductase in Vaccinium species.

    Science.gov (United States)

    Poonnachit, U; Darnell, R

    2004-04-01

    Most Vaccinium species have strict soil requirements for optimal growth, requiring low pH, high iron availability and nitrogen primarily in the ammonium form. These soils are limited and are often located near wetlands. Vaccinium arboreum is a wild species adapted to a wide range of soils, including high pH, low iron, and nitrate-containing soils. This broader soil adaptation in V. arboreum may be related to increased efficiency of iron or nitrate uptake compared with the cultivated Vaccinium species. Nitrate, ammonium and iron uptake, and nitrate reductase (NR) and ferric chelate reductase (FCR) activities were compared in two Vaccinium species grown hydroponically in either nitrate or ammonia, with or without iron. The species studied were the wild V. arboreum and the cultivated V. corymbosum interspecific hybrid, which exhibits the strict soil requirements of most Vaccinium species. Ammonium uptake was significantly greater than nitrate uptake in both species, while nitrate uptake was greater in the wild species, V. arboreum, compared with the cultivated species, V. corymbosum. The increased nitrate uptake in V. arboreum was correlated with increased root NR activity compared with V. corymbosum. The lower nitrate uptake in V. corymbosum was reflected in decreased plant dry weight in this species compared with V. arboreum. Root FCR activity increased significantly in V. corymbosum grown under iron-deficient conditions, compared with the same species grown under iron-sufficient conditions or with V. arboreum grown under either iron condition. V. arboreum appears to be more efficient in acquiring nitrate compared with V. corymbosum, possibly due to increased NR activity and this may partially explain the wider soil adaptation of V. arboreum.

  10. Nitrate radical oxidation of γ-terpinene: hydroxy nitrate, total organic nitrate, and secondary organic aerosol yields

    Science.gov (United States)

    Slade, Jonathan H.; de Perre, Chloé; Lee, Linda; Shepson, Paul B.

    2017-07-01

    Polyolefinic monoterpenes represent a potentially important but understudied source of organic nitrates (ONs) and secondary organic aerosol (SOA) following oxidation due to their high reactivity and propensity for multi-stage chemistry. Recent modeling work suggests that the oxidation of polyolefinic γ-terpinene can be the dominant source of nighttime ON in a mixed forest environment. However, the ON yields, aerosol partitioning behavior, and SOA yields from γ-terpinene oxidation by the nitrate radical (NO3), an important nighttime oxidant, have not been determined experimentally. In this work, we present a comprehensive experimental investigation of the total (gas + particle) ON, hydroxy nitrate, and SOA yields following γ-terpinene oxidation by NO3. Under dry conditions, the hydroxy nitrate yield = 4(+1/-3) %, total ON yield = 14(+3/-2) %, and SOA yield ≤ 10 % under atmospherically relevant particle mass loadings, similar to those for α-pinene + NO3. Using a chemical box model, we show that the measured concentrations of NO2 and γ-terpinene hydroxy nitrates can be reliably simulated from α-pinene + NO3 chemistry. This suggests that NO3 addition to either of the two internal double bonds of γ-terpinene primarily decomposes forming a relatively volatile keto-aldehyde, reconciling the small SOA yield observed here and for other internal olefinic terpenes. Based on aerosol partitioning analysis and identification of speciated particle-phase ON applying high-resolution liquid chromatography-mass spectrometry, we estimate that a significant fraction of the particle-phase ON has the hydroxy nitrate moiety. This work greatly contributes to our understanding of ON and SOA formation from polyolefin monoterpene oxidation, which could be important in the northern continental US and the Midwest, where polyolefinic monoterpene emissions are greatest.

  11. Ion dynamics in moltmolti melkaltal nitrates

    International Nuclear Information System (INIS)

    Kamiyama, Takashi; Nakamura, Yoshio; Shibata, Kaoru; Suzuki, Kenji.

    1993-01-01

    Quasielastic neutron scattering experiments have been performed on simple molten alkali metal nitrates, RbNO 3 and LiNO 3 . The experiments were carried out by the medium resolution inverted geometry spectrometer LAM-40 at KENS neutron scattering facility in Japan. The measured spectra are composed of narrow and broad quasielastic spectra. We assigned that the broad component corresponds to the fast intra-ionic motions in a nitrate ion. From momentum dependence of integrated intensity for this component it is found that the motion of nitrate ions in RbNO 3 melt is mainly the librational one centered C 3 axis on the ion. On the other hand the intra-ionic motion in LiNo 3 is the librational motion cnetered C 3 axis on the nitrate ion which amplitude is smaller than in RbNO 3 melt. This fact shows that the motion of nitrate ions in LiNO 3 is restricted strongly by surrounding cations. (author)

  12. In situ biodenitrification of nitrate surface water

    International Nuclear Information System (INIS)

    Schmidt, G.C.; Ballew, M.B.

    1995-01-01

    The US Department of Energy's Weldon Spring Site Remedial Action Project has successfully operated a full-scale in situ biodenitrification system to treat water with elevated nitrate levels in abandoned raffinate pits. Bench- and pilot-scale studies were conducted to evaluate the feasibility of the process and to support its full-scale design and application. Bench testing evaluated variables that would influence development of an active denitrifying biological culture. The variables were carbon source, phosphate source, presence and absence of raffinate sludge, addition of a commercially available denitrifying microbial culture, and the use of a microbial growth medium. Nitrate levels were reduced from 750 mg/L NO 3 -N to below 10 mg/L NO 3 -N within 17 days. Pilot testing simulated the full-scale process to determine if nitrate levels could be reduced to less than 10 mg/L NO 3 -N when high levels are present below the sludge surface. Four separate test systems were examined along with two control systems. Nitrates were reduced from 1,200 mg/L NO 3 -N to below 2 mg/L NO 3 -N within 21 days. Full-scale operation has been initiated to denitrify 900,000-gal batches alternating between two 1-acre ponds. The process used commercially available calcium acetate solution and monosodium/disodium phosphate solution as a nutrient source for indigenous microorganisms to convert nitrates to molecular nitrogen and water

  13. The influence of Glyceria maxima and nitrate input on the composition and nitrate metabolism of the dissimilatory nitrate-reducing bacterial community

    NARCIS (Netherlands)

    Nijburg, J.W.; Laanbroek, H.J.

    1997-01-01

    The influence of nitrate addition and the presence of Glyceria maxima (reed sweetgrass) on the composition and nitrate metabolism of the dissimilatory nitrate-reducing bacterial community was investigated. Anoxic freshwater sediment was incubated in pots with or without G. maxima and with or without

  14. The influence of Glyceria maxima and nitrate input on the composition and nitrate metabolism of the dissimilatory nitrate-reducing bacterial community

    NARCIS (Netherlands)

    Nijburg, J.W.; Laanbroek, H.J.

    1997-01-01

    The influence of nitrate addition and the presence of Glyceria maxima (reed sweetgrass) on the composition and nitrate metabolism of the dissimilatory nitrate-reducing bacterial community was investigated. Anoxic freshwater sediment was incubated in pots with or without G. maxima and with or

  15. MITIGASI PELINDIAN NITRAT PADA TANAH INCEPTISOL MELALUI PEMANFAATAN BAHAN NITRAT INHIBITOR ALAMI

    Directory of Open Access Journals (Sweden)

    Joko Pramono

    2012-05-01

    Full Text Available Mitigation of Nitrate Leaching in Inceptisol Soil Through the Use of Natural Nitrate Inhibitor ABSTRAK Pelindian NO3- merupakan salah satu mekanisme kehilangan N dalam aktivitas pertanian, yang dapat berdampak terhadap pencemaran lingkungan. Tujuan dari penelitian adalah untuk mengetahui penggunaan bahan alami sebagai nitrat inhibitor terhadap pelindian nitrat pada tanah Inceptisol. Pada penelitian ini diuji tiga jenis bahan nitrat inhibitor (NI alami yang berasal dari; serbuk biji Mimba (SBM, serbuk kulit kayu bakau (SKKB, dan serbuk daun kopi (SDK,yang dikombinasikan dengan tiga taraf dosis NI, yaitu: 20 %, 30 % dan 40 % dari urea yang diberikan, dan ditambah satu perlakuan kontrol tanpa NI. Bahan nitrat inhibitor diberikan bersama urea pada permukaan tanah dalam pot percobaan yang telah dibasahi dengan air suling. Hasil penelitian menunjukkan bahwa bahan NI yang berbeda memberikan respon terhadap penghambatan nitrifi kasi yang berbeda. Bahan NI yang berasal dari serbuk biji mimba memberikan tingkat penghambatan tertinggi sebesar (25,6 %, serbuk kulit kayu bakau sebesar (19,1 %, dan serbuk daun kopi sebesar 11,8 %. Bahan NI alami mampu menghambat nitrifi kasi melalui penghambatan pertumbuhan bakteri nitrifi kasi (pengoksida ammonium yang bersifat sementara pada kisaran 7-14 hari setelah aplikasi. Perlakuan berbagai bahan dan dosis NI mampu menekan pelindian nitrat rata-rata pada kisaran antara 56,6 sampai 62,8 % dan berbeda sangat nyata terhadap perlakuan kontrol tanpa NI. Bahan NI yang mampu menurunkan rata-rata pelindian nitrat pada pengamatan 14 hari setelah aplikasi tertinggi adalah SBM sebesar 74,15 %. Dosis optimal dua bahan NI terpilih yang menunjukkan kinerja penghambatan nitrifi kasi terbaik (SBM dan SKKB pada 7 hsa, masing-masing 18,30 % (R2 = 0,694 dan 21,67 % (R2=0.691 dari dosis urea yang diberikan. Kata kunci: Nitrifi kasi, nitrat inhibitor, pelindian nitrat ABSTRACT NO3 - leaching is one mechanism of N reduction in agricultural

  16. The extraction neptunium by trilaurylamine; L'extraction du neptunium par le trilaurylamine

    Energy Technology Data Exchange (ETDEWEB)

    Champion, J.; Chesne, A. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The extraction by trilaurylamine of neptunium (IV) from nitric acid and sulfuric acid-nitric acid media has been studied with the aim of developing a purification process for this element. Relative to the plutonium-neptunium separation, conditions are given for the oxidation of neptunium (IV) in sulfuric acid-nitric acid medium and data are presented on the stabilisation of the + 4 oxidation state by the organic solvent. Two procedures have been developed for the simultaneous purification of the two actinides. Both are based on the trilaurylamine extraction of the tetravalent nitrate species. The first utilises a constant redox potential fixed by Fe{sup +++} /Fe{sup ++} couple, while in the second, valencies are determined by successive addition of nitrite and ferrous ions. Gram quantities of neptunium 237 has been recovered from plutonium process solution. Alternate procedures are suggested for the chemical processing of irradiated Np{sup 237}. (authors) [French] L'extraction du neptunium par le trilaurylamine en milieu nitrique et sulfonitrique a ete etudiee dans le cadre de la recherche des procedes de purification de cet element. En vue d'effectuer la separation neptunium-plutonium on a precise d'une part les conditions d'oxydation du Np{sup 4+} en milieu sulfonitrique, d'autre part l'influence du solvant sur la stabilite des valences de ces deux elements. Deux procedes de purification simultanee des deux actinides ont ete developpes. Ils sont bases sur l'extraction du nitrate des elements tetravalents dans la trilaury lamine. Dans l'un, la solution a extraire a un potentiel redox fixe par un systeme auxiliaire (Fe{sup +++}/Fe{sup ++}), dans l'autre elle subit dans le meme extracteur des additions successives de nitrite et de fer ferreux. On decrit un essai semi-industriel de recuperation de neptunium 237 a partir de solution provenant de l'usine de production de plutonium de Marcoule. Differents schemas

  17. The extraction neptunium by trilaurylamine; L'extraction du neptunium par le trilaurylamine

    Energy Technology Data Exchange (ETDEWEB)

    Champion, J; Chesne, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The extraction by trilaurylamine of neptunium (IV) from nitric acid and sulfuric acid-nitric acid media has been studied with the aim of developing a purification process for this element. Relative to the plutonium-neptunium separation, conditions are given for the oxidation of neptunium (IV) in sulfuric acid-nitric acid medium and data are presented on the stabilisation of the + 4 oxidation state by the organic solvent. Two procedures have been developed for the simultaneous purification of the two actinides. Both are based on the trilaurylamine extraction of the tetravalent nitrate species. The first utilises a constant redox potential fixed by Fe{sup +++} /Fe{sup ++} couple, while in the second, valencies are determined by successive addition of nitrite and ferrous ions. Gram quantities of neptunium 237 has been recovered from plutonium process solution. Alternate procedures are suggested for the chemical processing of irradiated Np{sup 237}. (authors) [French] L'extraction du neptunium par le trilaurylamine en milieu nitrique et sulfonitrique a ete etudiee dans le cadre de la recherche des procedes de purification de cet element. En vue d'effectuer la separation neptunium-plutonium on a precise d'une part les conditions d'oxydation du Np{sup 4+} en milieu sulfonitrique, d'autre part l'influence du solvant sur la stabilite des valences de ces deux elements. Deux procedes de purification simultanee des deux actinides ont ete developpes. Ils sont bases sur l'extraction du nitrate des elements tetravalents dans la trilaury lamine. Dans l'un, la solution a extraire a un potentiel redox fixe par un systeme auxiliaire (Fe{sup +++}/Fe{sup ++}), dans l'autre elle subit dans le meme extracteur des additions successives de nitrite et de fer ferreux. On decrit un essai semi-industriel de recuperation de neptunium 237 a partir de solution provenant de l'usine de production de plutonium de Marcoule. Differents schemas utilisables lors du traitement chimique des cibles de

  18. Culture du bambou : diversification des moyens de subsistance des ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Culture du bambou : diversification des moyens de subsistance des petits producteurs de tabac du sud de la province de Nyanza, au Kenya - phase II. Au cours de la première phase du projet (projet no 103765), les chercheurs ont effectué une analyse de marché pour le bambou et les produits du bambou, comparé les ...

  19. Organic nitrates: past, present and future.

    Science.gov (United States)

    França-Silva, Maria S; Balarini, Camille M; Cruz, Josiane C; Khan, Barkat A; Rampelotto, Pabulo H; Braga, Valdir A

    2014-09-24

    Nitric oxide (NO) is one of the most important vasodilator molecules produced by the endothelium. It has already been established that NO/cGMP signaling pathway deficiencies are involved in the pathophysiological mechanisms of many cardiovascular diseases. In this context, the development of NO-releasing drugs for therapeutic use appears to be an effective alternative to replace the deficient endogenous NO and mimic the role of this molecule in the body. Organic nitrates represent the oldest class of NO donors that have been clinically used. Considering that tolerance can occur when these drugs are applied chronically, the search for new compounds of this class with lower tolerance potential is increasing. Here, we briefly discuss the mechanisms involved in nitrate tolerance and highlight some achievements from our group in the development of new organic nitrates and their preclinical application in cardiovascular disorders.

  20. [Can nitrates lead to indirect toxicity?].

    Science.gov (United States)

    Hamon, M

    2007-09-01

    For many years, nitrates have been used, at low dosages, as an additive in salted food. New laws have been promulgated to limit their concentration in water due to increased levels found in soils, rivers and even the aquifer. Although nitrate ions themselves have not toxic properties, bacterial reduction into nitrite ions (occurring even in aqueous medium) can lead to nitrous anhydride, which in turn generates nitrosonium ions. Nitrosium ions react with secondary amine to give nitrosamines, many of which are cancer-inducing agents at very low doses. Opinions on this toxicity are clear-cut and difficult to reconcile. In fact, increased levels are due, in a large part, to the use of nitrates as fertiliéers but also to bacterial transformation of human and animal nitrogenous wastes such as urea.

  1. Ammonium and nitrate tolerance in lichens

    Energy Technology Data Exchange (ETDEWEB)

    Hauck, Markus, E-mail: mhauck@gwdg.d [Department of Plant Ecology, Albrecht von Haller Institute of Plant Sciences, University of Goettingen, Untere Karspuele 2, 37073 Goettingen (Germany)

    2010-05-15

    Since lichens lack roots and take up water, solutes and gases over the entire thallus surface, these organisms respond more sensitively to changes in atmospheric purity than vascular plants. After centuries where effects of sulphur dioxide and acidity were in the focus of research on atmospheric chemistry and lichens, recently the globally increased levels of ammonia and nitrate increasingly affect lichen vegetation and gave rise to intense research on the tolerance of lichens to nitrogen pollution. The present paper discusses the main findings on the uptake of ammonia and nitrate in the lichen symbiosis and to the tolerance of lichens to eutrophication. Ammonia and nitrate are both efficiently taken up under ambient conditions. The tolerance to high nitrogen levels depends, among others, on the capability of the photobiont to provide sufficient amounts of carbon skeletons for ammonia assimilation. Lowly productive lichens are apparently predisposed to be sensitive to excess nitrogen. - Eutrophication has become a global threat for lichen diversity.

  2. COMMUNICATION DU CREDIT AGRICOLE - French version only

    CERN Multimedia

    2003-01-01

    La Direction du Crédit Agricole informe son aimable clientèle du CERN des jours et heures d'ouverture de l'agence du site de Prévessin à compter du mardi 14 janvier 2003 : 1. Horaires pour les opérations bancaires courantes 7 jours sur 7 et 24h/24 avec l'espace libre service bancaire. 2. Horaires conseil du mardi au vendredi - Mardi, de 9h. à 12h. et de 14h.15 à 16h.30. - Mercredi, jeudi et vendredi, de 9h. à 12h. et de 13h.30 à 16h.30. Deux collaboratrices au lieu d'une seront désormais présentes toute la journée du mardi au vendredi pour vous accueillir, vous informer et vous conseiller en crédits et placements (réception conseil sur rendez-vous). Autre nouveauté : les mêmes conseillers seront aussi à votre disposition le samedi, sur notre agence de Gex, de 8h.15 à 13h.05, notamment pour les études de financements habitat. La Direction et toute l'équipe de l'agence du Crédit Agricole vous souhaitent une excellent année 2003.

  3. Understanding organic nitrates – a vein hope?

    Science.gov (United States)

    Miller, Mark R; Wadsworth, Roger M

    2009-01-01

    The organic nitrate drugs, such as glyceryl trinitrate (GTN; nitroglycerin), are clinically effective in angina because of their dilator profile in veins and arteries. The exact mechanism of intracellular delivery of nitric oxide (NO), or another NO-containing species, from these compounds is not understood. However, mitochondrial aldehyde dehydrogenase (mtALDH) has recently been identified as an organic nitrate bioactivation enzyme. Nitrate tolerance, the loss of effect of organic nitrates over time, is caused by reduced bioactivation and/or generation of NO-scavenging oxygen-free radicals. In a recent issue of the British Journal of Pharmacology, Wenzl et al. show that guinea-pigs, deficient in ascorbate, also have impaired responsiveness to GTN, but nitrate tolerance was not due to ascorbate deficiency that exhibited divergent changes in mtALDH activity. Thus, the complex function of mtALDH appears to be the key to activation of GTN, the active NO species formed and the induction of tolerance that can limit clinical effectiveness of organic nitrate drugs. British Journal of Pharmacology (2009) 157, 565–567; doi:10.1111/j.1476-5381.2009.00193.x This article is part of a themed section on Endothelium in Pharmacology. For a list of all articles in this section see the end of this paper, or visit: http://www3.interscience.wiley.com/journal/121548564/issueyear?year=2009 The paper by Wenzl et al. is available from http://www3.interscience.wiley.com/cgi-bin/fulltext/122221718/PDFSTART PMID:19630835

  4. Nouvelles du Centre Aéré de l’Association du Personnel du CERN

    CERN Multimedia

    Jardin d'enfants

    2015-01-01

    Cet été 2015, durant quatre semaines d’été, le Centre Aéré a accueilli plus de 40 enfants âgés de 4 à 6 ans. Devant le succès rencontré, et à la demande des parents, il a été décidé d’en doubler la capacité maximale. A l'été 2016, du 4 au 29 juillet, la structure pourra accueillir les enfants de 4 ans révolus et de moins de 7 ans (nés après le 31/07/2009 mais avant  01/07/2012). Les inscriptions se feront à la semaine durant le mois d'Avril 2016. Les programmes sont en cours d'élaboration cependant nous pouvons déjà vous communiquer le thème conducteur du centre qui sera : à la découverte d'un continent différent chaque ...

  5. Factors controlling nitrate cracking of mild steel

    International Nuclear Information System (INIS)

    Donovan, J.A.

    1977-01-01

    Nitrite and hydroxide ions inhibit the growth of nitrate stress corrosion cracks in mild steel. Crack growth measurements showed that sufficient concentrations of nitrite and hydroxide ions can prevent crack growth; however, insufficient concentrations of these ions did not influence the Stage II growth rate or the threshold stress intensity, but extended the initiation time. Stage III growth was discontinuous. Oxide formed in the grain boundaries ahead of the crack tip and oxide dissolution (Stage II) and fracture (Stage III) are the proposed mechanisms of nitrate stress corrosion crack growth

  6. Preparation of high-purity cerium nitrate

    International Nuclear Information System (INIS)

    Avila, Daniela Moraes; Silva Queiroz, Carlos Alberto da; Santos Mucillo, Eliana Navarro dos

    1995-01-01

    The preparation of high-purity cerium nitrate has been carried out Cerium oxide has been prepared by fractioned precipitation and ionic exchange techniques, using a concentrate with approximately 85% of cerium oxide from NUCLEMON as raw material. Five sequential ion-exchange columns with a retention capacity of 170 g each have been used. The ethylenediamine-tetraacetic acid (EDTA) was used as eluent. The cerium content has been determined by gravimetry and iodometry techniques. The resulting cerium oxide has a purity > 99%. This material was transformed in cerium nitrate to be used as precursor for the preparation of Zirconia-ceria ceramics by the coprecipitation technique. (author)

  7. Methylhydrazinium nitrate. [rocket plume deposit chemistry

    Science.gov (United States)

    Lawton, E. A.; Moran, C. M.

    1983-01-01

    Methylhydrazinium nitrate was synthesized by the reaction of dilute nitric acid with methylhydrazine in water and in methanol. The white needles formed are extremely hygroscopic and melt at 37.5-40.5 C. The IR spectrum differs from that reported elsewhere. The mass spectrum exhibited no parent peak at 109 m/z, and thermogravimetric analysis indicated that the compound decomposed slowly at 63-103 C to give ammonium and methylammonium nitrate. The density is near 1.55 g/cu cm.

  8. Coordonnateur du bureau d'assistance | CRDI - Centre de ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Résumé des fonctions. En tant que membre de l'équipe du Bureau d'assistance au sein de la Section du service à la clientèle (SSC), le coordonnateur du Bureau d'assistance offre au personnel du Centre et aux autres utilisateurs reconnus des installations TI du Centre un soutien de première ligne en matière d'utilisation ...

  9. Density and electrical conductivity of molten salts. Comparative study of binary mixtures of alkali nitrates with silver nitrate and with thallium nitrate

    International Nuclear Information System (INIS)

    Brillant, S.

    1968-01-01

    The choice of methods and the number of measurements made enable us to give results on the density and electrical conductivity of molten binary mixtures, alkali nitrate and silver nitrate, and alkali nitrate and thallium nitrate, in the form of equations. The deviations from linearity of the volume and the molar conductivity are determined by calculating the corresponding excess values whose variations are analyzed as a function of the Tobolsky parameter. The absence of any relationship in the sign of the entropy and the excess volume is justified. It is shown that the silver and thallium nitrates, in contrast to the thermodynamic properties, behave as the alkali nitrates in so far as the excess conductivity is concerned. This result is confirmed by the study of changes in the activation enthalpy for the partial molar conductivity; this study also shows the particular behaviour of lithium nitrate. (author) [fr

  10. La population du Moyen-Orient et de l'Afrique du Nord contribue ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    29 avr. 2016 ... Le degré d'apport au contenu varie grandement d'une population à l'autre. Si les habitants du Moyen-Orient et de l'Afrique du Nord (région MENA) utilisent Wikipédia, ils y contribuent cependant moins que les populations d'autres régions du monde. Le contenu au sujet de la région MENA est, le plus ...

  11. L'action du CRDI — le développement du secteur privé

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cathy Egan

    Le CRDI est du nombre. Il reconnaît depuis longtemps la valeur de l'industrie, des échanges et du commerce comme moteurs de la croissance économique. Grâce au soutien concret qu'il a accordé au développement du secteur privé, le CRDI a appris que deux types d'aide peuvent porter fruit : améliorer le con- texte dans ...

  12. Determination of the total nitrate content of thorium nitrate solution with a selective electrode

    International Nuclear Information System (INIS)

    Wirkner, F.M.

    1979-01-01

    The nitrate content of thorium nitrate solutions is determined with a liquid membrane nitrate selective electrode utilizing the known addition method in 0.1 M potassium fluoride medium as ionic strength adjustor. It is studied the influence of pH and the presence of chloride, sulphate, phosphate, meta-silicate, thorium, rare earths, iron, titanium, uranium and zirconium at the same concentrations as for the aqueous feed solutions in the thorium purification process. The method is tested in synthetic samples and in samples proceeding from nitric dissolutions of thorium hidroxide and thorium oxicarbonate utilized as thorium concentrates to be purified [pt

  13. COGEMA Experience in Uranous Nitrate Preparation

    International Nuclear Information System (INIS)

    Tison, E.; Bretault, Ph.

    2006-01-01

    Separation and purification of plutonium by PUREX process is based on a sequence of extraction and back extraction which requires reducing plutonium Pu IV (extractable form) into Pu III (inextractable form) Different reducers can be used to reduce Pu IV into Pu III. Early plants such as that for Magnox fuel at Sellafield used ferrous sulfamate while UP 1 at Marcoule used uranous sulfamate. These reducers are efficient and easy to prepare but generates ferric and/or sulphate ions and so complicates management of the wastes from the plutonium purification cycle. Recent plants such as UP3 and UP2 800 at La Hague, THORP at Sellafield, and RRP at Rokkasho Mura (currently under tests) use uranous nitrate (U IV) stabilized by hydrazinium nitrate (N 2 H 5 NO 3 ) and hydroxyl ammonium nitrate (HAN). In the French plants, uranous nitrate is used in U-Pu separation and alpha barrier and HAN is used in Pu purification. Compared to sulfamate, U IV does not generate extraneous chemical species and uranyl nitrate (U VI) generated by reducing Pu IV follows the main uranium stream. More over uranous nitrate is prepared from reprocessed purified uranyl nitrate taken at the outlet of the reprocessing plant. Hydrazine and HAN offer the advantage to be salt-free reagents. Uranous nitrate can be generated either by electrolysis or by catalytic hydrogenation process. Electrolytic process has been implemented in early plant UP 1 at Marcoule (when changing reducer from uranous sulfamate to uranous nitrate) and was used again in UP2 plant at La Hague. However, the electrolytic process presented several disadvantages such as a low conversion rate and problems associated with the use of mercury. Electrolysis cells with no mercury were developed for the Eurochemic plant in Belgium and then implemented in the first Japanese reprocessing plant in Tokai-Mura. But finally, in 1975, the electrolytic process was abandoned in favor of the catalytic hydrogenation process developed at La Hague. The

  14. Sulphite metabolism; Metabolisme du sulfite

    Energy Technology Data Exchange (ETDEWEB)

    Fromageot, P; Chapeville, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Although the formation of sulphite by micro-organisms was observed as early as 1914 by Neuberg, it was only in 1932 that Nightingale showed it to be present inside cells, in the case of tomato leaf stalks, its formation being due to the reaction: SO{sub 3}H{sup -} + (S{sub 2}O{sub 3}){sub 2}{sup --} {yields} S{sub 2}O{sub 3}{sup --} + O{sub 3}S{sub 2}O{sub 3}{sup --}. The presence of the thiosulphate formed was shown by the high refractive index of its barium salt. Today we have a certain amount of data concerning the formation and use of sulphite in the living cell, even through the knowledge is still incomplete. In this article we will describe and discuss the facts which are known, with particular reference to the oxidation of sulphite. (author) [French] Si la formation de sulfite par des micro-organismes a ete observee des 1914 par Neuberg, sa presence a l'interieur des cellules a ete demontree pour la premiere fois par Nightingale en 1932, dans des tiges et des feuilles de tomates, par la reaction: SO{sub 3}H{sup -} + (S{sub 2}O{sub 3}){sub 2}{sup --} {yields} S{sub 2}O{sub 3}{sup --} + O{sub 3}S{sub 2}O{sub 3}{sup --}. Le thiosulfate forme etait mis en evidence par l'indice de refraction eleve de son sel de baryum. Aujourd'hui on possede un certain nombre de donnees, cependant encore tres incompletes, sur la formation du sulfite et son utilisation par la cellule vivante. Dans cet expose nous decrirons et discuterons quelques-unes de ces acquisitions, tout particulierement celles relatives a l'oxydation du sulfite. (auteur)

  15. Denitration of High Nitrate Salts Using Reductants

    Energy Technology Data Exchange (ETDEWEB)

    HD Smith; EO Jones; AJ Schmidt; AH Zacher; MD Brown; MR Elmore; SR Gano

    1999-05-03

    This report describes work conducted by Pacific Northwest National Laboratory (PNNL), in conjunction with Idaho National Engineering and Environmental Laboratory (INEEL), to remove nitrates in simulated low-activity waste (LAW). The major objective of this work was to provide data for identifying and demonstrating a technically viable and cost-effective approach to condition LAW for immobilization (grout).

  16. The Path to Nitrate Salt Disposition

    Energy Technology Data Exchange (ETDEWEB)

    Funk, David John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-16

    The topic is presented in a series of slides arranged according to the following outline: LANL nitrate salt incident as thermal runaway (thermally sensitive surrogates, full-scale tests), temperature control for processing, treatment options and down selection, assessment of engineering options, anticipated control set for treatment, and summary of the overall steps for RNS.

  17. 76 FR 47238 - Ammonium Nitrate From Russia

    Science.gov (United States)

    2011-08-04

    ... Russia Determination On the basis of the record \\1\\ developed in the subject five-year review, the United... nitrate from Russia would be likely to lead to continuation or recurrence of material injury to an industry in the United States within a reasonably foreseeable time. \\1\\ The record is defined in sec. 207.2...

  18. Nitrates, Nitrites, and Health. Bulletin 750.

    Science.gov (United States)

    Deeb, Barbara S.; Sloan, Kenneth W.

    This review is intended to assess available literature in order to define the range of nitrate/nitrite effects on animals. Though the literature deals primarily with livestock and experimental animals, much of the contemporary research is concerned with human nitrite intoxication. Thus, the effects on man are discussed where appropriate. Some of…

  19. Trend Analyses of Nitrate in Danish Groundwater

    DEFF Research Database (Denmark)

    Hansen, B.; Thorling, L.; Dalgaard, Tommy

    2012-01-01

    This presentation assesses the long-term development in the oxic groundwater nitrate concentration and nitrogen (N) loss due to intensive farming in Denmark. Firstly, up to 20-year time-series from the national groundwater monitoring network enable a statistically systematic analysis of distribut......This presentation assesses the long-term development in the oxic groundwater nitrate concentration and nitrogen (N) loss due to intensive farming in Denmark. Firstly, up to 20-year time-series from the national groundwater monitoring network enable a statistically systematic analysis...... of distribution, trends and trend reversals in the groundwater nitrate concentration. Secondly, knowledge about the N surplus in Danish agriculture since 1950 is used as an indicator of the potential loss of N. Thirdly, groundwater recharge CFC (Chlorofluorocarbon) age determination allows linking of the first...... two dataset. The development in the nitrate concentration of oxic groundwater clearly mirrors the development in the national agricultural N surplus, and a corresponding trend reversal is found in groundwater. Regulation and technical improvements in the intensive farming in Denmark have succeeded...

  20. Revitalising Silver Nitrate for Caries Management

    Directory of Open Access Journals (Sweden)

    Sherry Shiqian Gao

    2018-01-01

    Full Text Available Silver nitrate has been adopted for medical use as a disinfectant for eye disease and burned wounds. In dentistry, it is an active ingredient of Howe’s solution used to prevent and arrest dental caries. While medical use of silver nitrate as a disinfectant became subsidiary with the discovery of antibiotics, its use in caries treatment also diminished with the use of fluoride in caries prevention. Since then, fluoride agents, particularly sodium fluoride, have gained popularity in caries prevention. However, caries is an infection caused by cariogenic bacteria, which demineralise enamel and dentine. Caries can progress and cause pulpal infection, but its progression can be halted through remineralisation. Sodium fluoride promotes remineralisation and silver nitrate has a profound antimicrobial effect. Hence, silver nitrate solution has been reintroduced for use with sodium fluoride varnish to arrest caries as a medical model strategy of caries management. Although the treatment permanently stains caries lesions black, this treatment protocol is simple, painless, non-invasive, and low-cost. It is well accepted by many clinicians and patients and therefore appears to be a promising strategy for caries control, particularly for young children, the elderly, and patients with severe caries risk or special needs.

  1. Modular Regiospecific Synthesis of Nitrated Fatty Acids

    DEFF Research Database (Denmark)

    Hock, Katharina J.; Grimmer, Jennifer; Göbel, Dominik

    2016-01-01

    Endogenous nitrated fatty acids are an important class of signaling molecules. Herein a modular route for the efficient and regiospecific preparation of nitrooleic acids as well as various analogues is described. The approach is based on a simple set of alkyl halides as common building blocks...

  2. Spectrophotometric Determination of Nitrate and Phosphate Levels ...

    African Journals Online (AJOL)

    Twelve drinking water samples from boreholes were collected from various sampling sites around the vicinity of Kura irrigated farmlands using polythene plastic containers and were analysed for the nitrate and phosphate levels using uV – visible spectrophotometer. From the results, it was found that all the samples had ...

  3. Thermal characterization of aminium nitrate nanoparticles.

    Science.gov (United States)

    Salo, Kent; Westerlund, Jonathan; Andersson, Patrik U; Nielsen, Claus; D'Anna, Barbara; Hallquist, Mattias

    2011-10-27

    Amines are widely used and originate from both anthropogenic and natural sources. Recently, there is, in addition, a raised concern about emissions of small amines formed as degradation products of the more complex amines used in CO(2) capture and storage systems. Amines are bases and can readily contribute to aerosol mass and number concentration via acid-base reactions but are also subject to gas phase oxidation forming secondary organic aerosols. To provide more insight into the atmospheric fate of the amines, this paper addresses the volatility properties of aminium nitrates suggested to be produced in the atmosphere from acid-base reactions of amines with nitric acid. The enthalpy of vaporization has been determined for the aminium nitrates of mono-, di-, trimethylamine, ethylamine, and monoethanolamine. The enthalpy of vaporization was determined from volatility measurements of laboratory generated aerosol nanoparticles using a volatility tandem differential mobility analyzer set up. The determined enthalpy of vaporization for aminium nitrates range from 54 up to 74 kJ mol(-1), and the calculated vapor pressures at 298 K are around 10(-4) Pa. These values indicate that aminium nitrates can take part in gas-to-particle partitioning at ambient conditions and have the potential to nucleate under high NO(x) conditions, e.g., in combustion plumes.

  4. Production of thorium nitrate from uranothorianite ores

    International Nuclear Information System (INIS)

    Brodsky, M.; Sartorius, R.; Sousseuer, Y.

    1959-01-01

    The separation of thorium and uranium from uranothorianite ores, either by precipitation or solvent-extraction methods, are discussed, and an industrial process for the manufacture of thorium nitrate is described. Reprint of a paper published in 'Progress in Nuclear Energy' Series III, Vol. 2 - Process Chemistry, 1959, p. 68-76 [fr

  5. Detonation characteristics of ammonium nitrate products

    NARCIS (Netherlands)

    Kersten, R.J.A.; Hengel, E.I.V. van den; Steen, A.C. van der

    2006-01-01

    The detonation properties of ammonium nitrate (AN) products depend on many factors and are therefore, despite the large amount of information on this topic, difficult to assess. In order to further improve the understanding of the safety properties of AN, the European Fertilizer Manufacturers

  6. Monnaie du commun et revenu social garanti

    OpenAIRE

    Baronian, Laurent; Vercellone, Carlo

    2015-01-01

    Le but de cet article est de poser les bases d’une approche de la monnaie du commun à partir d’une interrogation évincée par la théorie économique des biens communs. Notre analyse de la relation entre monnaie et théorie du commun s’articulera en trois parties. Dans la première, il s’agit d’établir une conception dynamique du commun au singulier dans laquelle la question de la monnaie et des mutations de la division du travail occupe une place centrale. Cette démarche fondée sur la triade trav...

  7. Paysans du Brésil

    Directory of Open Access Journals (Sweden)

    Dominique Temple

    2007-01-01

    Full Text Available Eric Sabourin, « Paysans du Brésil : Entre échange marchand et réciprocité » Paris, Editions Quae, 241p, 30 euros, (préface de Maxime Haubert, 2007Dans la présentation du livre, Maxime Haubert dit :«Cet ouvrage propose une analyse socio-anthropologique et agronomique des sociétés rurales et paysannes du Brésil et des transformations qu'elles ont connues ces dernières décennies, en particulier face aux interventions de l'Etat et à l'expansion du marché capitaliste (.... «Le livre pose d'abor...

  8. Daphne du Maurier' unustatud jutud / Udo Uibo

    Index Scriptorium Estoniae

    Uibo, Udo, 1956-

    2011-01-01

    Ajalehe "The Independent" teatel kavatseb kirjastus "Virago" maikuus avaldada Daphne Du Maurier lühiproosa kogumiku "Nukk" (The Doll), mille on koostanud tema loomingu suur austaja Ann Willmore ja mis sisaldab 13 unustatud ja seni avaldamata novelli

  9. Relationship between nitrate reductase and nitrate uptake in phytoplankton in the Peru upwelling region

    International Nuclear Information System (INIS)

    Blasco, D.; MacIsaac, J.J.; Packard, T.T.; Dugdale, R.C.

    1984-01-01

    Nitrate reductase (NR) activity and 15 NO 3 - uptake in phytoplankton were compared under different environmental conditions on two cruises in the upwelling region off Peru. The NR activity and NO 3 - uptake rates responded differently to light and nutrients and the differences led to variations in the uptake: reductase ratio. Analysis of these variations suggests that the re-equilibration time of the two processes in response to environmental perturbation is an important source of variability. The nitrate uptake system responds faster than the nitrate reductase system. Considering these differences in response time the basic differences in the two processes, and the differences in their measurement, the authors conclude that the Nr activity measures the current nitrate-reducing potential, which reflects NO 3 - assimilation before the sampling time, while 15 NO 3 - uptake measures NO 3 - assimilation in the 6-h period following sampling

  10. Evidence for a plasma-membrane-bound nitrate reductase involved in nitrate uptake of Chlorella sorokiniana

    Science.gov (United States)

    Tischner, R.; Ward, M. R.; Huffaker, R. C.

    1989-01-01

    Anti-nitrate-reductase (NR) immunoglobulin-G (IgG) fragments inhibited nitrate uptake into Chlorella cells but had no affect on nitrate uptake. Intact anti-NR serum and preimmune IgG fragments had no affect on nitrate uptake. Membrane-associated NR was detected in plasma-membrane (PM) fractions isolated by aqueous two-phase partitioning. The PM-associated NR was not removed by sonicating PM vesicles in 500 mM NaCl and 1 mM ethylenediaminetetraacetic acid and represented up to 0.8% of the total Chlorella NR activity. The PM NR was solubilized by Triton X-100 and inactivated by Chlorella NR antiserum. Plasma-membrane NR was present in ammonium-grown Chlorella cells that completely lacked soluble NR activity. The subunit sizes of the PM and soluble NRs were 60 and 95 kDa, respectively, as determined by sodium-dodecyl-sulfate electrophoresis and western blotting.

  11. Nitrates in surface waters, inputs and seasonality: Phase 2

    OpenAIRE

    Casey, H.; Clarke, R.T.; Smith, S.

    1988-01-01

    Changes in management practices and agricultural productivity over the past twenty years have lead to nitrate pollution and eutrophication of lakes and rivers. Information on nitrate concentrations and discharge has been collected on the River Frome at East Stoke since 1965, using the same analytical nitrate method so that the results are comparable. These records of weekly spot values of nitrate concentration and daily mean discharges have been analysed for trends and seasonal patterns in bo...

  12. Aux frontières du politique et du religieux

    Directory of Open Access Journals (Sweden)

    Frédéric Sylvanise

    2006-05-01

    Full Text Available The Autobiography of Miss Jane Pittman met en scène de manière spectaculaire deux figures de leadership noir-américain au XIXe siècle (Ned et au XXe siècle (Jimmy. Ned, fils adoptif de Jane Pittman, se rebaptise Professor Douglass en hommage au leader abolitionniste Frederick Douglass. S’il est fondamentalement laïc (il est instituteur, le texte lui confère néanmoins une dimension religieuse, notamment dans le chapitre intitulé « The Sermon at the River » , qui renvoie à la fois à Moïse (le fleuve et à Jésus (le sermon sur la montagne. Abattu par un tueur à gages, Ned est un martyr dont l’histoire était déjà écrite. Le personnage de Jimmy, attendu par toute une communauté comme le messie (alors que lui aussi est un laïc et un homme qui perd la foi, s’inscrit dans la même histoire. Lettré, éloquent et impliqué dans le mouvement pour les droits civils, il est assassiné comme son prédécesseur. Dans les deux cas, le texte lie donc le politique et le biblique comme s’il ne faisait qu’un : être un leader politique, c’est être un preacher et un messie qui guide le peuple. Il est possible de lire l’évocation de ces deux hommes à la lumière d’une certaine actualité. Ned et Jimmy connaissent en effet un sort proche de celui de Malcolm X et de Martin Luther King, récemment assassinés au moment de l’écriture de The Autobiography of Miss Jane Pittman. C’est l’histoire de la répression du leadership noir, au travers du portrait de deux de ses avatars, qui peut donc se lire en creux ici.

  13. Complications du traitement traditionnel des fractures : aspects ...

    African Journals Online (AJOL)

    Tous les patients reçus avec des complications du traitement traditionnel des fractures ont été inclus dans ce travail. Le diagnostic des lésions était clinique et radiologique. Nous avions reçu 51 patients porteurs de complications suite à des traitements de médecine traditionnelle, soit 13,7% du total des patients hospitalisés ...

  14. Le désordre du monde

    African Journals Online (AJOL)

    sulaiman.adebowale

    Le début du XXIe siècle se caractérise par l'accumulation et la consécution ..... Unis a présidé à la naissance aux forceps de cet outil d'équilibre du monde en ... De toute évidence, l'ONU reste l'instrument qui a marqué le siècle dernier,.

  15. Identification of nitrate sources and discharge-depending nitrate dynamics in a mesoscale catchment

    Science.gov (United States)

    Mueller, Christin; Strachauer, Ulrike; Brauns, Mario; Musolff, Andreas; Kunz, Julia Vanessa; Brase, Lisa; Tarasova, Larisa; Merz, Ralf; Knöller, Kay

    2017-04-01

    During the last decades, nitrate concentrations in surface and groundwater have increased due to land use change and accompanying application of fertilizer in agriculture as well as increased atmospheric deposition. To mitigate nutrient impacts on downstream aquatic ecosystems, it is important to quantify potential nitrate sources, instream nitrate processing and its controls in a river system. The objective of this project is to characterize and quantify (regional) scale dynamics and trends in water and nitrogen fluxes of the entire Holtemme river catchment in central Germany making use of isotopic fingerprinting methods. Here we compare two key date sampling campaigns in 2014 and 2015, with spatially highly resolved measurements of discharge at 23 sampling locations including 11 major tributaries and 12 locations at the main river. Additionally, we have data from continuous runoff measurements at 10 locations operated by the local water authorities. Two waste water treatment plants contribute nitrogen to the Holtemme stream. This contribution impacts nitrate loads and nitrate isotopic signatures depending on the prevailing hydrological conditions. Nitrogen isotopic signatures in the catchment are mainly controlled by different sources (nitrified soil nitrogen in the headwater and manure/ effluents from WWTPs in the lowlands) and increase with raising nitrate concentrations along the main river. Nitrate loads at the outlet of the catchment are extremely different between both sampling campaigns (2014: NO3- = 97 t a-1, 2015: NO3- = 5 t a-1) which is associated with various runoff (2014: 0.8 m3 s-1, 2015: 0.2 m3 s-1). In 2015, the inflow from WWTP's raises the NO3- loads and enriches δ18O-NO3 values. Generally, oxygen isotope signatures from nitrate are more variable and are controlled by biogeochemical processes in concert with the oxygen isotopic composition of the ambient water. Elevated δ18O-NO3 in 2015 are most likely due to higher temperatures and lower

  16. Electrochemical processing of nitrate waste solutions

    International Nuclear Information System (INIS)

    Genders, D.; Weinberg, N.; Hartsough, D.

    1992-01-01

    The second phase of research performed at The Electrosynthesis Co., Inc. has demonstrated the successful removal of nitrite and nitrate from a synthetic effluent stream via a direct electrochemical reduction at a cathode. It was shown that direct reduction occurs at good current efficiencies in 1,000 hour studies. The membrane separation process is not readily achievable for the removal of nitrites and nitrates due to poor current efficiencies and membrane stability problems. A direct reduction process was studied at various cathode materials in a flow cell using the complete synthetic mix. Lead was found to be the cathode material of choice, displaying good current efficiencies and stability in short and long term tests under conditions of high temperature and high current density. Several anode materials were studied in both undivided and divided cell configurations. A divided cell configuration was preferable because it would prevent re-oxidation of nitrite by the anode. The technical objective of eliminating electrode fouling and solids formation was achieved although anode materials which had demonstrated good stability in short term divided cell tests corroded in 1,000 hour experiments. The cause for corrosion is thought to be F - ions from the synthetic mix migrating across the cation exchange membrane and forming HF in the acid anolyte. Other possibilities for anode materials were explored. A membrane separation process was investigated which employs an anion and cation exchange membrane to remove nitrite and nitrate, recovering caustic and nitric acid. Present research has shown poor current efficiencies for nitrite and nitrate transport across the anion exchange membrane due to co-migration of hydroxide anions. Precipitates form within the anion exchange membranes which would eventually result in the failure of the membranes. Electrochemical processing offers a highly promising and viable method for the treatment of nitrate waste solutions

  17. Evaluation of Nitrate Transport in Clay Soil

    Directory of Open Access Journals (Sweden)

    Morteza Seyedian

    2016-09-01

    Full Text Available  Background and purpose: With the increase in world population and the need to provide food, farmers are now using a variety of chemical fertilizers, organic pesticides have turned. Indiscriminate use of these inputs without considering its side effects, both environmental problems and brings in terms of human health. Among these, organic fertilizers contain soluble compounds such as nitrate. These compounds through precipitation or irrigation of the soil solution, groundwater and surface water resources are. The purpose of this study was to determine the amount of nitrate transport in clay and simulation software using HYDRUS2D. Methods: In order to perform it, 5 different height of soil column 20, 40, 60, 80 and 100 cm selected. In thicknesses of 20, 40, 60 and 80 cm respectively output levels after a period of 6, 12, 18 and 22 hours to input the concentration of nitrate (50 mg/lit is. In thicknesses of 20, 40, 60 and 80 cm, respectively, after the time of 5/6, 5/12, 21, and 25-hour concentration of 50 mg/lit is output. In thickness 20, 40, 60 and 80cm, outlet concentration after 6, 12, 18 and 22 minutes inlet concentration (50mg/lit. Results: The result showed that Hydrus software ability of simulates nitrate movement in soil and result of Hydrus software and laboratory data near. Conclusions: With increasing soil thickness difference HYDRUS2D results and experimental data more and more time to transfer nitrate were spent with increasing thickness. 

  18. Amperometric nitrate biosensor based on Carbon nanotube/Polypyrrole/Nitrate reductase biofilm electrode

    Energy Technology Data Exchange (ETDEWEB)

    Can, Faruk; Korkut Ozoner, Seyda; Ergenekon, Pinar; Erhan, Elif, E-mail: e.erhan@gyte.edu.tr

    2012-01-01

    This study describes the construction and characterization of an amperometric nitrate biosensor based on the Polypyrrole (PPy)/Carbon nanotubes (CNTs) film. Nitrate reductase (NR) was both entrapped into the growing PPy film and chemically immobilized via the carboxyl groups of CNTs to the CNT/PPy film electrode. The optimum amperometric response for nitrate was obtained in 0.1 M phosphate buffer solution (PBS), pH 7.5 including 0.1 M lithium chloride and 7 mM potassium ferricyanide with an applied potential of 0.13 V (vs. Ag/AgCl, 3 M NaCl). Sensitivity was found to be 300 nA/mM in a linear range of 0.44-1.45 mM with a regression coefficient of 0.97. The biosensor response showed a higher linear range in comparison to standard nitrate analysis methods which were tested in this study and NADH based nitrate biosensors. A minimum detectable concentration of 0.17 mM (S/N = 3) with a relative standard deviation (RSD) of 5.4% (n = 7) was obtained for the biosensor. Phenol and glucose inhibit the electrochemical reaction strictly at a concentration of 1 {mu}g/L and 20 mg/L, respectively. The biosensor response retained 70% of its initial response over 10 day usage period when used everyday. - Highlights: Black-Right-Pointing-Pointer K{sub 3}Fe(CN){sub 6} has been used for the first time as mediator for nitrate reductase. Black-Right-Pointing-Pointer Better performance was obtained in comparison to other nitrate biosensor studies operated with various mediators. Black-Right-Pointing-Pointer Analytical parameters were better than standard nitrate analysis methods.

  19. Amperometric nitrate biosensor based on Carbon nanotube/Polypyrrole/Nitrate reductase biofilm electrode

    International Nuclear Information System (INIS)

    Can, Faruk; Korkut Ozoner, Seyda; Ergenekon, Pinar; Erhan, Elif

    2012-01-01

    This study describes the construction and characterization of an amperometric nitrate biosensor based on the Polypyrrole (PPy)/Carbon nanotubes (CNTs) film. Nitrate reductase (NR) was both entrapped into the growing PPy film and chemically immobilized via the carboxyl groups of CNTs to the CNT/PPy film electrode. The optimum amperometric response for nitrate was obtained in 0.1 M phosphate buffer solution (PBS), pH 7.5 including 0.1 M lithium chloride and 7 mM potassium ferricyanide with an applied potential of 0.13 V (vs. Ag/AgCl, 3 M NaCl). Sensitivity was found to be 300 nA/mM in a linear range of 0.44–1.45 mM with a regression coefficient of 0.97. The biosensor response showed a higher linear range in comparison to standard nitrate analysis methods which were tested in this study and NADH based nitrate biosensors. A minimum detectable concentration of 0.17 mM (S/N = 3) with a relative standard deviation (RSD) of 5.4% (n = 7) was obtained for the biosensor. Phenol and glucose inhibit the electrochemical reaction strictly at a concentration of 1 μg/L and 20 mg/L, respectively. The biosensor response retained 70% of its initial response over 10 day usage period when used everyday. - Highlights: ► K 3 Fe(CN) 6 has been used for the first time as mediator for nitrate reductase. ► Better performance was obtained in comparison to other nitrate biosensor studies operated with various mediators. ► Analytical parameters were better than standard nitrate analysis methods.

  20. Nitrate removal from high strength nitrate-bearing wastes in granular sludge sequencing batch reactors.

    Science.gov (United States)

    Krishna Mohan, Tulasi Venkata; Renu, Kadali; Nancharaiah, Yarlagadda Venkata; Satya Sai, Pedapati Murali; Venugopalan, Vayalam Purath

    2016-02-01

    A 6-L sequencing batch reactor (SBR) was operated for development of granular sludge capable of denitrification of high strength nitrates. Complete and stable denitrification of up to 5420 mg L(-1) nitrate-N (2710 mg L(-1) nitrate-N in reactor) was achieved by feeding simulated nitrate waste at a C/N ratio of 3. Compact and dense denitrifying granular sludge with relatively stable microbial community was developed during reactor operation. Accumulation of large amounts of nitrite due to incomplete denitrification occurred when the SBR was fed with 5420 mg L(-1) NO3-N at a C/N ratio of 2. Complete denitrification could not be achieved at this C/N ratio, even after one week of reactor operation as the nitrite levels continued to accumulate. In order to improve denitrification performance, the reactor was fed with nitrate concentrations of 1354 mg L(-1), while keeping C/N ratio at 2. Subsequently, nitrate concentration in the feed was increased in a step-wise manner to establish complete denitrification of 5420 mg L(-1) NO3-N at a C/N ratio of 2. The results show that substrate concentration plays an important role in denitrification of high strength nitrate by influencing nitrite accumulation. Complete denitrification of high strength nitrates can be achieved at lower substrate concentrations, by an appropriate acclimatization strategy. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  1. The contribution of bnnrt1 and bnnrt2 to nitrate accumulation varied ...

    African Journals Online (AJOL)

    USER

    2010-08-02

    Aug 2, 2010 ... stronger ability to assimilate absorbed nitrate in SYM than the low accumulator, HGQGC. Key words: ... studied the mechanism of nitrate accumulation in plant ..... Elevated carbon dioxide increases nitrate uptake and nitrate.

  2. Nitrate removal by electro-bioremediation technology in Korean soil

    International Nuclear Information System (INIS)

    Choi, Jeong-Hee; Maruthamuthu, Sundaram; Lee, Hyun-Goo; Ha, Tae-Hyun; Bae, Jeong-Hyo

    2009-01-01

    The nitrate concentration of surface has become a serious concern in agricultural industry through out the world. In the present study, nitrate was removed in the soil by employing electro-bioremediation, a hybrid technology of bioremediation and electrokinetics. The abundance of Bacillus spp. as nitrate reducing bacteria were isolated and identified from the soil sample collected from a greenhouse at Jinju City of Gyengsangnamdo, South Korea. The nitrate reducing bacterial species were identified by 16 s RNA sequencing technique. The efficiency of bacterial isolates on nitrate removal in broth was tested. The experiment was conducted in an electrokinetic (EK) cell by applying 20 V across the electrodes. The nitrate reducing bacteria (Bacillus spp.) were inoculated in the soil for nitrate removal process by the addition of necessary nutrient. The influence of nitrate reducers on electrokinetic process was also studied. The concentration of nitrate at anodic area of soil was higher when compared to cathode in electrokinetic system, while adding bacteria in EK (EK + bio) system, the nitrate concentration was almost nil in all the area of soil. The bacteria supplies electron from organic degradation (humic substances) and enhances NO 3 - reduction (denitrification). Experimental results showed that the electro-bio kinetic process viz. electroosmosis and physiological activity of bacteria reduced nitrate in soil environment effectively. Involvement of Bacillus spp. on nitrification was controlled by electrokinetics at cathode area by reduction of ammonium ions to nitrogen gas. The excellence of the combined electro-bio kinetics technology on nitrate removal is discussed.

  3. 21 CFR 176.320 - Sodium nitrate-urea complex.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium nitrate-urea complex. 176.320 Section 176... Substances for Use Only as Components of Paper and Paperboard § 176.320 Sodium nitrate-urea complex. Sodium nitrate-urea complex may be safely used as a component of articles intended for use in producing...

  4. Inactivation of Yersinia enterocolitica by nitrite and nitrate in food.

    Science.gov (United States)

    de Giusti, M; de Vito, E

    1992-01-01

    The antimicrobial effects of sodium nitrite and sodium and potassium nitrate against Yersinia enterocolitica were investigated in solution and in treated pork meat. Potassium nitrate and sodium nitrate showed only feeble antimicrobial activity in cultures; no antimicrobial activity was detected with sodium nitrite. Conversely, all three salts displayed apparent antimicrobial activity in pork meat, possibly due to selective effects on competitive flora.

  5. 9 CFR 319.2 - Products and nitrates and nitrites.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Products and nitrates and nitrites... and nitrates and nitrites. Any product, such as frankfurters and corned beef, for which there is a standard in this part and to which nitrate or nitrite is permitted or required to be added, may be prepared...

  6. A nitrate sensitive planar optode; performance and interferences

    DEFF Research Database (Denmark)

    Pedersen, Lasse; Dechesne, Arnaud; Smets, Barth F.

    2015-01-01

    We present a newly developed nitrate sensitive planar optode. It exhibits a linear response to nitrate from 1 to 50 mM at pH 8.0, a fast response time below 10 s and a good lifetime, allowing for fast two dimensional nitrate measurements over long periods of time. Interference from nitrite...

  7. Nitrate ammonification in mangrove soils: A hidden source of nitrite?

    NARCIS (Netherlands)

    Balk, M.; Laverman, A.M.; Keuskamp, J.A.; Laanbroek, H.J.

    2015-01-01

    Nitrate reduction is considered to be a minor microbial pathway in the oxidation of mangrove-derived organic matter due to a limited supply of nitrate in mangrove soils. At a limited availability of this electron acceptor compared to the supply of degradable carbon, nitrate ammonification is thought

  8. Extraction of nitric acid, uranyl nitrate, and bismuth nitrate from aqueous nitric acid solutions with CMPO

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, B.B.

    1995-08-01

    DOE sponsored development of the transuranium extraction (TRUEX) process for removing actinides from radioactive wastes. The solvent is a mixture of CMPO and TBP. Since the extraction characteristics of CMPO are not as well understood as those of TBP, the extraction of nitric acid, uranyl nitrate, and bismuth nitrate with CMPO (dissolved in n-dodecane) were studied. Results indicate that CMPO extracts nitric acid with a 1:1 stoichiometry; equilibrium constant is 2. 660{plus_minus}0.092 at 25 C, and extraction enthalpy is -5. 46{plus_minus}0.46 kcal/mol. Slope analysis indicates that uranyl nitrate extracts with a mixed equilibria of 1:1 and 2:1 stoichiometries in nearly equal proportion. Equil. constant of the 2: 1 extraction was 1.213 {times} 10{sup 6}{plus_minus}3.56 {times} 10{sup 4} at 25 C; reaction enthalpy was -9.610{plus_minus}0.594 kcal/mol. Nitration complexation constant is 8.412{plus_minus}0.579, with an enthalpy of -10.72{plus_minus}1.87 kcal/mol. Bismuth nitrate also extracts with a mixed equilibria of (perhaps) 1:1 and 2:1 stoichiometries. A 2:1 extraction equilibrium and a nitrate complexation adequately model the data. Kinetics and enthalpies were also measured.

  9. Extraction of nitric acid, uranyl nitrate, and bismuth nitrate from aqueous nitric acid solutions with CMPO

    International Nuclear Information System (INIS)

    Spencer, B.B.

    1995-08-01

    DOE sponsored development of the transuranium extraction (TRUEX) process for removing actinides from radioactive wastes. The solvent is a mixture of CMPO and TBP. Since the extraction characteristics of CMPO are not as well understood as those of TBP, the extraction of nitric acid, uranyl nitrate, and bismuth nitrate with CMPO (dissolved in n-dodecane) were studied. Results indicate that CMPO extracts nitric acid with a 1:1 stoichiometry; equilibrium constant is 2. 660±0.092 at 25 C, and extraction enthalpy is -5. 46±0.46 kcal/mol. Slope analysis indicates that uranyl nitrate extracts with a mixed equilibria of 1:1 and 2:1 stoichiometries in nearly equal proportion. Equil. constant of the 2: 1 extraction was 1.213 x 10 6 ±3.56 x 10 4 at 25 C; reaction enthalpy was -9.610±0.594 kcal/mol. Nitration complexation constant is 8.412±0.579, with an enthalpy of -10.72±1.87 kcal/mol. Bismuth nitrate also extracts with a mixed equilibria of (perhaps) 1:1 and 2:1 stoichiometries. A 2:1 extraction equilibrium and a nitrate complexation adequately model the data. Kinetics and enthalpies were also measured

  10. The nitrate time bomb: a numerical way to investigate nitrate storage and lag time in the unsaturated zone.

    Science.gov (United States)

    Wang, L; Butcher, A S; Stuart, M E; Gooddy, D C; Bloomfield, J P

    2013-10-01

    Nitrate pollution in groundwater, which is mainly from agricultural activities, remains an international problem. It threatens the environment, economics and human health. There is a rising trend in nitrate concentrations in many UK groundwater bodies. Research has shown it can take decades for leached nitrate from the soil to discharge into groundwater and surface water due to the 'store' of nitrate and its potentially long travel time in the unsaturated and saturated zones. However, this time lag is rarely considered in current water nitrate management and policy development. The aim of this study was to develop a catchment-scale integrated numerical method to investigate the nitrate lag time in the groundwater system, and the Eden Valley, UK, was selected as a case study area. The method involves three models, namely the nitrate time bomb-a process-based model to simulate the nitrate transport in the unsaturated zone (USZ), GISGroundwater--a GISGroundwater flow model, and N-FM--a model to simulate the nitrate transport in the saturated zone. This study answers the scientific questions of when the nitrate currently in the groundwater was loaded into the unsaturated zones and eventually reached the water table; is the rising groundwater nitrate concentration in the study area caused by historic nitrate load; what caused the uneven distribution of groundwater nitrate concentration in the study area; and whether the historic peak nitrate loading has reached the water table in the area. The groundwater nitrate in the area was mainly from the 1980s to 2000s, whilst the groundwater nitrate in most of the source protection zones leached into the system during 1940s-1970s; the large and spatially variable thickness of the USZ is one of the major reasons for unevenly distributed groundwater nitrate concentrations in the study area; the peak nitrate loading around 1983 has affected most of the study area. For areas around the Bowscar, Beacon Edge, Low Plains, Nord Vue

  11. Pru du 2S albumin or Pru du vicilin?

    Science.gov (United States)

    Garino, Cristiano; De Paolis, Angelo; Coïsson, Jean Daniel; Arlorio, Marco

    2015-06-01

    A short partial sequence of 28 amino acids is all the information we have so far about the putative allergen 2S albumin from almond. The aim of this work was to analyze this information using mainly bioinformatics tools, in order to verify its rightness. Based on the results reported in the paper describing this allergen from almond, we analyzed the original data of amino acids sequencing through available software. The degree of homology of the almond 12kDa protein with any other known 2S albumin appears to be much lower than the one reported in the paper that firstly described it. In a publicly available cDNA library we discovered an expressed sequence tag which translation generates a protein that perfectly matches both of the sequencing outputs described in the same paper. A further analysis indicated that the latter protein seems to belong to the vicilin superfamily rather than to the prolamin one. The fact that also vicilins are seed storage proteins known to be highly allergenic would explain the IgE reactivity originally observed. Based on our observations we suggest that the IgE reactive 12kDa protein from almond currently known as Pru du 2S albumin is in reality the cleaved N-terminal region of a 7S vicilin like protein. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. The nitrate time bomb : a numerical way to investigate nitrate storage and lag time in the unsaturated zone

    OpenAIRE

    Wang, L.; Butcher, A.S.; Stuart, M.E.; Gooddy, D.C.; Bloomfield, J.P.

    2013-01-01

    Nitrate pollution in groundwater, which is mainly from agricultural activities, remains an international problem. It threatens the environment, economics and human health. There is a rising trend in nitrate concentrations in many UK groundwater bodies. Research has shown it can take decades for leached nitrate from the soil to discharge into groundwater and surface water due to the ‘store’ of nitrate and its potentially long travel time in the unsaturated and satura...

  13. Protein Tyrosine Nitration : Selectivity, Physicochemical and Biological Consequences, Denitration, and Proteomics Methods for the Identification of Tyrosine-Nitrated Proteins

    NARCIS (Netherlands)

    Abello, Nicolas; Kerstjens, Huib A. M.; Postma, Dirkje S.; Bischoff, Rainer

    Protein tyrosine nitration (PTN) is a post-translational modification occurring under the action of a nitrating agent. Tyrosine is modified in the 3-position of the phenolic ring through the addition of a nitro group (NO(2)). In the present article, we review the main nitration reactions and

  14. Les effets du changement climatique dans le bassin du Congo : la ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    22 avr. 2016 ... Dans le bassin du fleuve Congo, plus de 80 % des habitants vivent exclusivement de l'agriculture, de la pêche, de l'élevage et de la cueillette, qui sont des activités largement tributaires du climat.

  15. Engagez-vous, devenez délégué(e) du personnel du CERN

    CERN Multimedia

    Staff Association

    2017-01-01

    Dans notre ECHO N° 275, nous avons annoncé les élections à venir au Conseil du personnel du CERN. Dans le présent ECHO, nous vous informons du lancement du processus des élections qui débute par le dépôt des candidatures. Tous les titulaires, boursiers et associés, qui sont aussi membres de l’Association du personnel, peuvent s’engager et déposer leur candidature entre le 11 septembre à 08 h 00 et le 13 octobre 2017 à 17 h 00. N’hésitez plus, remplissez le formulaire de candidature, présentez-vous aux élections au Conseil du personnel afin de pouvoir représenter et défendre vos collègues du personnel du CERN. ÊTRE DÉLÉGUÉ(E), C’EST QUOI ? Poser la question à plusieurs d...

  16. Aux marges du monde arabe

    Directory of Open Access Journals (Sweden)

    Hélène Thiollet

    2004-09-01

    Full Text Available L’étude des migrations contemporaines des Érythréens vers le Yémen au tournant des années quatre-vingt-dix permet d’observer les transformations des dynamiques régionales à l’œuvre dans le monde arabe. Les migrations sont un phénomène sensible aux différents aspects (politiques, économiques, culturels, géographiques de l’intégration régionale. Celle si est envisagée dans cet article à travers une approche doublement marginale : -la marginalité géographique de l’Érythrée arabo-africaine et du Yémen, économi­quement isolé dans la péninsule Arabique, -l’étude des migrations formelles et informelles, élément souvent marginal dans l’étude des institutions et des échanges qui constituent un système régional intégré. Cette étude est fondée sur une série d’entretiens menés au Yémen entre février et avril 2002 auprès des administrations yéménites et de la population érythréenne.

  17. Study of the coefficient of separation for some processes which are applied to lithium isotopes; Etude du coefficient de separation de quelques processus concernant les isotopes du lithium

    Energy Technology Data Exchange (ETDEWEB)

    Perret, L.; Rozand, L.; Saito, E. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The fundamental separation factors of some processes are investigated: the distillation of metallic lithium, counter current electromigration in fused salts (particularly in lithium nitrate) electrolysis in aqueous solution and ion exchange. The chemical transfer between a lithium amalgam and lithium salts in a dimethylformamide solution (a solvent which is not attacked by the amalgam) is also studied. Finally a description is given of isotopic analyses carried out either by scintillation counting or by mass spectrography using apparatus specially designed for this particular task. (author) [French] Les facteurs de separation elementaires de quelques processus connus sont etudies: distillation du lithium metallique, electromigration a contre-courant en sels fondus (en particulier le nitrate), electrolyse en solution aqueuse et echange d'ions. L'echange chimique entre l'amalgame de lithium et les sels de lithium en solution dans la dimethylformamide - solvant non attaque par l'amalgame - est egalement etudie. Enfin, on decrit les methodes d 'analyse isotopique, soit par comptage par scintillation, soit par spectrometrie de masse au moyen d'un appareil specialement concu pour cet usage particulier. (auteur)

  18. Study of the coefficient of separation for some processes which are applied to lithium isotopes; Etude du coefficient de separation de quelques processus concernant les isotopes du lithium

    Energy Technology Data Exchange (ETDEWEB)

    Perret, L; Rozand, L; Saito, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The fundamental separation factors of some processes are investigated: the distillation of metallic lithium, counter current electromigration in fused salts (particularly in lithium nitrate) electrolysis in aqueous solution and ion exchange. The chemical transfer between a lithium amalgam and lithium salts in a dimethylformamide solution (a solvent which is not attacked by the amalgam) is also studied. Finally a description is given of isotopic analyses carried out either by scintillation counting or by mass spectrography using apparatus specially designed for this particular task. (author) [French] Les facteurs de separation elementaires de quelques processus connus sont etudies: distillation du lithium metallique, electromigration a contre-courant en sels fondus (en particulier le nitrate), electrolyse en solution aqueuse et echange d'ions. L'echange chimique entre l'amalgame de lithium et les sels de lithium en solution dans la dimethylformamide - solvant non attaque par l'amalgame - est egalement etudie. Enfin, on decrit les methodes d 'analyse isotopique, soit par comptage par scintillation, soit par spectrometrie de masse au moyen d'un appareil specialement concu pour cet usage particulier. (auteur)

  19. Seasonal nitrate algorithms for nitrate retrieval using OCEANSAT-2 and MODIS-AQUA satellite data.

    Science.gov (United States)

    Durairaj, Poornima; Sarangi, Ranjit Kumar; Ramalingam, Shanthi; Thirunavukarassu, Thangaradjou; Chauhan, Prakash

    2015-04-01

    In situ datasets of nitrate, sea surface temperature (SST), and chlorophyll a (chl a) collected during the monthly coastal samplings and organized cruises along the Tamilnadu and Andhra Pradesh coast between 2009 and 2013 were used to develop seasonal nitrate algorithms. The nitrate algorithms have been built up based on the three-dimensional regressions between SST, chl a, and nitrate in situ data using linear, Gaussian, Lorentzian, and paraboloid function fittings. Among these four functions, paraboloid was found to be better with the highest co-efficient of determination (postmonsoon: R2=0.711, n=357; summer: R2=0.635, n=302; premonsoon: R2=0.829, n=249; and monsoon: R2=0.692, n=272) for all seasons. Based on these fittings, seasonal nitrate images were generated using the concurrent satellite data of SST from Moderate Resolution Imaging Spectroradiometer (MODIS) and chlorophyll (chl) from Ocean Color Monitor (OCM-2) and MODIS. The best retrieval of modeled nitrate (R2=0.527, root mean square error (RMSE)=3.72, and mean normalized bias (MNB)=0.821) was observed for the postmonsoon season due to the better retrieval of both SST MODIS (28 February 2012, R2=0.651, RMSE=2.037, and MNB=0.068) and chl OCM-2 (R2=0.534, RMSE=0.317, and MNB=0.27). Present results confirm that the chl OCM-2 and SST MODIS retrieve nitrate well than the MODIS-derived chl and SST largely due to the better retrieval of chl by OCM-2 than MODIS.

  20. Open-Source Photometric System for Enzymatic Nitrate Quantification.

    Science.gov (United States)

    Wittbrodt, B T; Squires, D A; Walbeck, J; Campbell, E; Campbell, W H; Pearce, J M

    2015-01-01

    Nitrate, the most oxidized form of nitrogen, is regulated to protect people and animals from harmful levels as there is a large over abundance due to anthropogenic factors. Widespread field testing for nitrate could begin to address the nitrate pollution problem, however, the Cadmium Reduction Method, the leading certified method to detect and quantify nitrate, demands the use of a toxic heavy metal. An alternative, the recently proposed Environmental Protection Agency Nitrate Reductase Nitrate-Nitrogen Analysis Method, eliminates this problem but requires an expensive proprietary spectrophotometer. The development of an inexpensive portable, handheld photometer will greatly expedite field nitrate analysis to combat pollution. To accomplish this goal, a methodology for the design, development, and technical validation of an improved open-source water testing platform capable of performing Nitrate Reductase Nitrate-Nitrogen Analysis Method. This approach is evaluated for its potential to i) eliminate the need for toxic chemicals in water testing for nitrate and nitrite, ii) reduce the cost of equipment to perform this method for measurement for water quality, and iii) make the method easier to carryout in the field. The device is able to perform as well as commercial proprietary systems for less than 15% of the cost for materials. This allows for greater access to the technology and the new, safer nitrate testing technique.

  1. Observations on particulate organic nitrates and unidentified components of NOy

    DEFF Research Database (Denmark)

    Nielsen, T.; Egeløv, A.H.; Granby, K.

    1995-01-01

    A method to determine the total content of particulate organic nitrates (PON) has been developed and ambient air measurements of PON, NO, NO2, HNO3, peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), gas NOy and particulate inorganic nitrate have been performed in the spring and early...... summer al an agricultural site in Denmark and compared with measurements of ozone, H2O2, SO2, formic acid, acetic acid and methane sulphonic acid. The gas NOy detector determines the sum NO + NO2 + HNO2 + HNO3 + PAN + PPN + gas phase organic nitrates + 2 x N2O5 + NO3. The content of residual gas NOy...... = gas NOy + particulate inorganic nitrate). Residual gas NOy was much higher than the particulate fraction of organic nitrates (PON). PON was only 0.25 +/- 0.11% of concentrations of photochemical oxidants in connection with high-pressure systems suggesting atmospheric processes being the major source...

  2. Review on Thermal Decomposition of Ammonium Nitrate

    Science.gov (United States)

    Chaturvedi, Shalini; Dave, Pragnesh N.

    2013-01-01

    In this review data from the literature on thermal decomposition of ammonium nitrate (AN) and the effect of additives to their thermal decomposition are summarized. The effect of additives like oxides, cations, inorganic acids, organic compounds, phase-stablized CuO, etc., is discussed. The effect of an additive mainly occurs at the exothermic peak of pure AN in a temperature range of 200°C to 140°C.

  3. Genetic basis for nitrate resistance in Desulfovibrio strains

    Directory of Open Access Journals (Sweden)

    Hannah eKorte

    2014-04-01

    Full Text Available Nitrate is an inhibitor of sulfate-reducing bacteria (SRB. In petroleum production sites, amendments of nitrate and nitrite are used to prevent SRB production of sulfide that causes souring of oil wells. A better understanding of nitrate stress responses in the model SRB, Desulfovibrio vulgaris Hildenborough and Desulfovibrio alaskensis G20, will strengthen predictions of environmental outcomes. Nitrate inhibition of SRB has historically been considered to result from the generation of small amounts of nitrite, to which SRB are quite sensitive. Here we explored the possibility that nitrate might inhibit SRB by a mechanism other than through nitrite inhibition. We found that nitrate-stressed D. vulgaris cultures grown in lactate-sulfate conditions eventually grew in the presence of high concentrations of nitrate, and their resistance continued through several subcultures. Nitrate consumption was not detected over the course of the experiment, suggesting adaptation to nitrate. With high-throughput genetic approaches employing TnLE-seq for D. vulgaris and a pooled mutant library of D. alaskensis, we determined the fitness of many transposon mutants of both organisms in nitrate stress conditions. We found that several mutants, including homologs present in both strains, had a greatly increased ability to grow in the presence of nitrate but not nitrite. The mutated genes conferring nitrate resistance included the gene encoding the putative Rex transcriptional regulator (DVU0916/Dde_2702, as well as a cluster of genes (DVU0251-DVU0245/Dde_0597-Dde_0605 that is poorly annotated. Follow-up studies with individual D. vulgaris transposon and deletion mutants confirmed high-throughput results. We conclude that, in D. vulgaris and D. alaskensis, nitrate resistance in wild-type cultures is likely conferred by spontaneous mutations. Furthermore, the mechanisms that confer nitrate resistance may be different from those that confer nitrite resistance.

  4. Simultaneous analysis of uranium and nitrate

    Energy Technology Data Exchange (ETDEWEB)

    Bostick, D.T.

    1978-04-01

    A direct spectrophotometric method has been developed for the determination of 20 to 200 g/l of uranium in the presence of 3 to 5 M nitric acid. A dual-wavelength analysis is used to eliminate the enhancing effect of nitrate ion on the uranium visible spectra. The precision and accuracy of the simultaneous analysis of uranium and nitrate were compared using combinations of the four uranium wavelength maxima, occurring at 426, 416, 403 and 359 nm. Calculations based on 426 and 416 nm data yielded the most accurate results. The calculated relative standard deviation of uranium and nitrate concentrations was 5.4 percent and 15.5 percent, respectively. The photometric procedure is slightly affected by temperature; an increase of one degree centigrade results in a 0.2 g/l overestimation of uranium concentration. Because the method is non-destructive, it is directly applicable to the continuous in-line analysis of dissolved uranium in aqueous fuel reprocessing streams.

  5. Cirque du Monde as a health intervention

    Science.gov (United States)

    Fournier, Cynthia; Drouin, Mélodie-Anne; Marcoux, Jérémie; Garel, Patricia; Bochud, Emmanuel; Théberge, Julie; Aubertin, Patrice; Favreau, Gil; Fleet, Richard

    2014-01-01

    Abstract Objective To present Cirque du Soleil’s social circus program, Cirque du Monde, to explore its potential as a primary health care tool for family physicians. Data sources A review of the literature in PubMed, the Cochrane Library, PsycINFO, LaPresse, Eureka, Google Scholar, and Érudit using the key words circus, social circus, Cirque du Monde, and Cirque du Soleil; a Montreal-based initiative, Espace Transition, modeled on Cirque du Monde; and personal communication with Cirque du Soleil’s Social Circus Training Advisor. Study selection The first 50 articles or websites identified for each key word in each of the databases were examined on the basis of their titles and abstracts in the case of articles, and on the basis of their titles and page content in the case of websites. Articles and websites that explored an aspect of social circuses or that described an intervention that involved circuses were then retained for analysis. Because all literature on social circuses was searched, no criterion for year of publication was used. Synthesis No articles on the social circus as a health intervention were found. One study on the use of the circus as an intervention in schools was identified. It demonstrated an increase in self-esteem in the children who took part. One study on the use of the circus in a First Nations community was found; it contained nonspecific, qualitative findings. The other articles identified were merely descriptions of social circuses. One website was identified on the use of the social circus to help youth who had been treated in a hospital setting for major psychiatric disorders to re-enter the community. The team in the pediatric psychiatry department at Centre Hospitalier Universitaire Sainte-Justine, the children’s hospital in Montreal, Que, was contacted; they were leading this project, called Espace Transition. The unpublished preliminary findings of its pilot project demonstrate substantial improvements in overall patient

  6. Electrochemical determination of nitrate with nitrate reductase-immobilized electrodes under ambient air.

    Science.gov (United States)

    Quan, De; Shim, Jun Ho; Kim, Jong Dae; Park, Hyung Soo; Cha, Geun Sig; Nam, Hakhyun

    2005-07-15

    Nitrate monitoring biosensors were prepared by immobilizing nitrate reductase derived from yeast on a glassy carbon electrode (GCE, d = 3 mm) or screen-printed carbon paste electrode (SPCE, d = 3 mm) using a polymer (poly(vinyl alcohol)) entrapment method. The sensor could directly determine the nitrate in an unpurged aqueous solution with the aid of an appropriate oxygen scavenger: the nitrate reduction reaction driven by the enzyme and an electron-transfer mediator, methyl viologen, at -0.85 V (GCE vs Ag/AgCl) or at -0.90 V (SPCE vs Ag/AgCl) exhibited no oxygen interference in a sulfite-added solution. The electroanalytical properties of optimized biosensors were measured: the sensitivity, linear response range, and detection limit of the sensors based on GCE were 7.3 nA/microM, 15-300 microM (r2 = 0.995), and 4.1 microM (S/N = 3), respectively, and those of SPCE were 5.5 nA/microM, 15-250 microM (r2 = 0.996), and 5.5 microM (S/N = 3), respectively. The disposable SPCE-based biosensor with a built-in well- or capillary-type sample cell provided high sensor-to-sensor reproducibility (RSD sensor system was demonstrated by determining nitrate in real samples.

  7. Plutonium purification cycle in centrifugal extractors: comparative study of flowsheets using uranous nitrate and hydroxylamine nitrate

    International Nuclear Information System (INIS)

    Baron, P.; Dinh, B.; Mauborgne, B.; Drain, F.; Gillet, B.

    1998-01-01

    The extension of the UP2 plant at La Hague includes a new plutonium purification cycle using multi-stage centrifugal extractors, to replace the present cycle which uses mixer/settler banks. The advantage of this type of extractor is basically the compactness of the equipment and the short residence time, which limits solvent degradation, particularly when reprocessing fuel containing a high proportion of plutonium 238. Two types of reducing agents have been considered for the plutonium stripping operation, uranous nitrate and hydroxylamine nitrate. Uranous nitrate displays a very fast reduction kinetics, ideal for the very short residence time of the phases in the centrifugal extractors. However, its extractability in the organic phase exacerbates the undesirable re-oxidation of plutonium, which is present in high concentration in this stage of the process. The short residence time of the centrifugal extractors is an advantage in as much as it could conceivably be adequate to obtain a sufficient reduction efficiency, while minimizing undesirable re-oxidation mechanisms. Hydroxylamine nitrate helps to minimize undesirable re-oxidation and is the normal choice for this type of operation. However, the plutonium (IV) reduction kinetics obtained is slower than with uranous nitrate, making it necessary to check whether its use is compatible with the very short residence times of centrifugal extractors.This article discusses the feasibility studies employing these two reducing agents. (author)

  8. Établissements recevant du public

    CERN Document Server

    2014-01-01

    Synthèse pour les installations électriques, des règles de sécurité contre les risques d’incendie et de panique dans les établissements recevant du public (ERP), selon l’arrêté du 25 juin 1980 modifié. L'ouvrage traite à la fois des dispositions communes aux établissements du 1er groupe (1ère à 4ème catégorie), du 2ème groupe (5ème catégorie) et des règles particulières applicables aux différents types d'établissements (structures d'accueil pour personnes âgées ou handicapées, hôtels, magasins de vente, restaurants et débit de boisson, établissements de soins, administration, châpiteaux, etc...) Sont ainsi notamment traités, dans le cadre des dispositions communes aux établissements du 1er groupe, pour les installations électriques normales : les installations des appareils, tableaux et canalisations, les locaux électriques et installation de machines, l'éclairage normal des locaux accessibles au public, le chauffage et la ventilation, l'installation d'eau chaude sanita...

  9. Sådan kan du bruge optioner og futures

    DEFF Research Database (Denmark)

    Kohl, Niklas

    2017-01-01

    Masterclass. Har du brug for at forsikre værdierne i din portefølje i en periode, hvor du forventer stor uro på finansmarkederne, kan du gøre det med optioner eller futures. Her kan du læse om de forskellige typer – og om de muligheder de giver dig.......Masterclass. Har du brug for at forsikre værdierne i din portefølje i en periode, hvor du forventer stor uro på finansmarkederne, kan du gøre det med optioner eller futures. Her kan du læse om de forskellige typer – og om de muligheder de giver dig....

  10. Science et technologie du collage

    CERN Document Server

    Cognard, Jacques

    2003-01-01

    L'Homme a su coller avant de savoir écrire et compter. Le collage est en effet l'une des premières techniques d'assemblage d'une structure que l'homme ait utilisée, technique qui n'est devenue science qu'au début du 20e siècle avec la fabrication des premières colles synthétiques. Cette science de l'adhésion a considérablement progressé ces dix dernières années et ce livre présente l'état actuel des connaissances en décrivant les progrès considérables réalisés dans la compréhension des phénomènes fondamentaux qui font qu'un collage tient bien et durablement. Après l'exposé des bases scientifiques nécessaires et des modèles théoriques récents, l'auteur introduit la distinction entre collages faibles et collages forts puis expose les difficultés rencontrées dans les cas pratiques, difficultés souvent dues à la complexité de la chimie des surfaces et des réactions surface-polymère. L'ouvrage se termine par la présentation de quelques applications récentes, en particulier dans...

  11. Nitrates for acute heart failure syndromes.

    Science.gov (United States)

    Wakai, Abel; McCabe, Aileen; Kidney, Rachel; Brooks, Steven C; Seupaul, Rawle A; Diercks, Deborah B; Salter, Nigel; Fermann, Gregory J; Pospisil, Caroline

    2013-08-06

    Current drug therapy for acute heart failure syndromes (AHFS) consists mainly of diuretics supplemented by vasodilators or inotropes. Nitrates have been used as vasodilators in AHFS for many years and have been shown to improve some aspects of AHFS in some small studies. The aim of this review was to determine the clinical efficacy and safety of nitrate vasodilators in AHFS. To quantify the effect of different nitrate preparations (isosorbide dinitrate and nitroglycerin) and the effect of route of administration of nitrates on clinical outcome, and to evaluate the safety and tolerability of nitrates in the management of AHFS. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 3), MEDLINE (1950 to July week 2 2011) and EMBASE (1980 to week 28 2011). We searched the Current Controlled Trials MetaRegister of Clinical Trials (compiled by Current Science) (July 2011). We checked the reference lists of trials and contacted trial authors. We imposed no language restriction. Randomised controlled trials comparing nitrates (isosorbide dinitrate and nitroglycerin) with alternative interventions (frusemide and morphine, frusemide alone, hydralazine, prenalterol, intravenous nesiritide and placebo) in the management of AHFS in adults aged 18 and over. Two authors independently performed data extraction. Two authors performed trial quality assessment. We used mean difference (MD), odds ratio (OR) and 95% confidence intervals (CI) to measure effect sizes. Two authors independently assessed and rated the methodological quality of each trial using the Cochrane Collaboration tool for assessing risk of bias. Four studies (634 participants) met the inclusion criteria. Two of the included studies included only patients with AHFS following acute myocardial infarction (AMI); one study excluded patients with overt AMI; and one study included participants with AHFS with and without acute coronary syndromes.Based on a single study

  12. Accroissement du recours aux politiques fiscales dans la lutte ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Incidence de la hausse des taxes sur le tabac et du prix des produits du tabac en Ukraine, en Russie et au Bélarus. La recherche destinée aux responsables des politiques de l'Ukraine, de la Russie et du Bélarus mettra en évidence la façon dont les mesures de taxation des produits du tabac peuvent contribuer.

  13. Properties and thermal decomposition of the double salts of uranyl nitrate-ammonium nitrate

    International Nuclear Information System (INIS)

    Notz, K.J.; Haas, R.A.

    1989-01-01

    The formation of ammonium nitrate-uranyl nitrate double salts has important effects on the thermal denitration process for the preparation of UO 3 and on the physical properties of the resulting product. Analyses were performed, and properties and decomposition behavior were determined for three double salts: NH 4 UO 2 (NO 3 ) 3 , (NH 4 ) 2 UO 2 (NO 3 ) 4 , and (NH 4 ) 2 UO 2 (NO 3 ) 4 ·2H 2 O. The tinitrate salt decomposes without melting at 270-300 C to give a γ-UO 3 powder of ∼3-μm average size, with good ceramic properties for fabrication into UO 2 nuclear fuel pellets. The tetranitrate dihydrate melts at 48 C; it also dehydrates to the anhydrous salt. The anhydrous tetranitrate decomposes exothermically, without melting, at 170-270 C by losing one mole of ammonium nitrate to form the trinitrate salt

  14. Couzeix – Les Terres du Puy Dieu

    OpenAIRE

    Maniquet, Christophe

    2013-01-01

    Identifiant de l'opération archéologique : 122281 Date de l'opération : 2005 (EX) Dans le cadre du projet de construction d'un lotissement constitué de trois pavillons au lieu-dit « Les Terres du Puy Dieu », un diagnostic archéologique a été prescrit par le service régional de l'Archéologie. En effet, plusieurs sites archéologiques avaient été inventoriés à proximité immédiate de la zone d'intervention. On notera, en particulier, la découverte en 1982, près du Puy Dieu, au cours de travaux de...

  15. Extraction and purification of plutonium by a tertiary amine; Extraction et purification du plutonium par une amine tertiaire

    Energy Technology Data Exchange (ETDEWEB)

    Trentinian, M de; Chesne, A [Commissariat a l' Energie Atomique, Fontenay aux Roses, Section de Chimie des Actimides (France).Centre d' Etudes Nucleaires; Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    Trilaurylamine diluted with a paraffinic solvent (dodecane) was studied as part of the research dealing with the separation and purification of plutonium. The physical properties (solubility of nitrates in the amine as a function of temperature) and the resistance to radiations of this substance were examined. The extraction characteristics of nitric solutions of plutonium, uranium and certain fission products are given as a function of the following factors: concentration of the various ions in solution, valency states. A method of plutonium purification based on these results is presented. (author) [French] La trilaurylamine diluee par un solvant paraffinique (dodecane) a ete etudiee dans le cadre des recherches concernant la separation et la purification du plutonium. Une etude des caracteres physiques (solubilite des nitrates dans l'amine en fonction de la temperature) s'ajoute a celle de la tenue aux radiations de ce corps. Les caracteristiques d'extraction de solutions nitriques de plutonium, uranium, et certains produits de fission, sont donnes en fonction des facteurs suivants: concentration des differents ions en solution, etats de valence. On presente une methode de purification du plutonium basee sur ces resultats. (auteur)

  16. A rapid method of dosing plutonium in radioactive effluents; Methode de dosage rapide du plutonium dans les effluents radioactifs (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Scheidhauer, J; Messainguiral, L [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

    1961-07-01

    The plutonium is first separated by a lanthanum fluoride precipitation. The precipitated fluorides are dissolved in normal nitric acid solution in the presence of aluminium nitrate. The plutonium transformed to the tetravalent state is then extracted with thenoyltrifluoroacetone and returned to the aqueous phase with 10 N nitric acid. After evaporation on a watch glass the residue is calcined on a Meker burner and counted using a counting system fitted with a zinc sulphide scintillator. When necessary, the calcium is eliminated at the beginning of the dosage by a fluoride precipitation, the plutonium being oxidised to the valency IV. (authors) [French] Le plutonium est d'abord separe par entrainement au fluorure de lanthane. Le precipite des fluorures est remis en solution en milieu acide nitrique normal, en presence de nitrate d'aluminium. Le plutonium amene a la valence IV est alors extrait par la thenoyltrifluoroacetone et remis en phase aqueuse dans l'acide nitrique 10 N. Apres evaporation sur verre de montre, le residu est calcine sur bec Meker et compte sur un ensemble de comptage equipe d'un scintillateur au sulfure de zinc. Lorsque cela est necessaire, le calcium est elimine, au debut du dosage, par precipitation du fluorure, le plutonium etant oxyde a la valence VI. (auteurs)

  17. Growing patterns to produce 'nitrate-free' lettuce (Lactuca sativa).

    Science.gov (United States)

    Croitoru, Mircea Dumitru; Muntean, Daniela-Lucia; Fülöp, Ibolya; Modroiu, Adriana

    2015-01-01

    Vegetables can contain significant amounts of nitrate and, therefore, may pose health hazards to consumers by exceeding the accepted daily intake for nitrate. Different hydroponic growing patterns were examined in this work in order to obtain 'nitrate-free lettuces'. Growing lettuces on low nitrate content nutrient solution resulted in a significant decrease in lettuces' nitrate concentrations (1741 versus 39 mg kg(-1)), however the beneficial effect was cancelled out by an increase in the ambient temperature. Nitrate replacement with ammonium was associated with an important decrease of the lettuces' nitrate concentration (from 1896 to 14 mg kg(-1)) and survival rate. An economically feasible method to reduce nitrate concentrations was the removal of all inorganic nitrogen from the nutrient solution before the exponential growth phase. This method led to lettuces almost devoid of nitrate (10 mg kg(-1)). The dried mass and calcinated mass of lettuces, used as markers of lettuces' quality, were not influenced by this treatment, but a small reduction (18%, p < 0.05) in the fresh mass was recorded. The concentrations of nitrite in the lettuces and their modifications are also discussed in the paper. It is possible to obtain 'nitrate-free' lettuces in an economically feasible way.

  18. Concentration of Nitrate in Bottled Drinking Water in Qom, Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Saberi Bidgoli

    2013-11-01

    Full Text Available Background & Aims of the Study: The global consumption of bottled water is growing with substantial growth in sales volumes on every continent. The highest growth rates are occurring in Asia and South America. Biological and chemical monitoring of these waters is necessary. The aim of current study was determination of nitrate concentration in bottled drinking water in Qom, Iran in 2012. Materials & Methods: A cross-sectional study carried out in Qom, Iran. First of all, 18 most frequent brands of bottled drinking waters were purchased in June 2012 randomly. Then concentration of nitrate was measured according to the spectrophotometric method. In next step, experiment data were analyzed by Excel Software and P value was obtained by statistical calculations. Finally data were comprised with written nitrate concentration on labels and recommended permissible values . Results: The median nitrate concentration was 2.1 mg/L with the minimum 0.8 mg/L and maximum 8.1 mg/L. In 66.7 % of the samples, the measured nitrate concentrations were less than the written nitrate concentrations and in 33.3% of samples, the nitrate concentration was higher. The statistical calculation proved the significant difference between the median of written nitrate concentration on the label and investigated nitrate concentration (P value > 0.05. Conclusions: It be concluded that the measured nitrate concentration in all of the water samples is below the recommended permissible level.

  19. Management of Nitrate m Groundwater: A Simulation Study

    Directory of Open Access Journals (Sweden)

    M. Ahmed

    2001-01-01

    Full Text Available Agriculture may cause nitrate and other chemicals to enter into groundwater systems. Nitrate in drinking water is considered a health hazard. A study was conducted to assess the extent of nitrate pollution of groundwater caused by agriculture and to evaluate the possibility of using the LEACHN model to manage nitrate entry into groundwater of agricultural areas of Al-Batinah, which is the most important agricultural region of Oman. Groundwater samples were collected and analyzed to assess the problem and to detect possible trends. Soil sampling and analyses were done to demonstrate the difference in the nitrate concentration in agricultural and non-agricultural soils. A questionnaire survey was conducted to gather information on agricultural practices, fertilizer input, and other possible sources of nitrate pollution. Results from the study show that 23% of groundwater samples have a concentration of nitrate-N concentration of 10 mg/l and 34% samples exceed 8 mg/l. Agricultural soils have higher levels of nitrate compared to non- agricultural soils. Results also demonstrate that nitrate levels in groundwater in Al-Batinah are rising. Application of the ‘LEACHN’ model demonstrated its suitability for use as a management tool to reduce nitrate leaching to groundwater by controlling fertilizer and water input.

  20. Chronic nitrate exposure alters reproductive physiology in fathead minnows.

    Science.gov (United States)

    Kellock, Kristen A; Moore, Adrian P; Bringolf, Robert B

    2018-01-01

    Nitrate is a ubiquitous aquatic pollutant that is commonly associated with eutrophication and dead zones in estuaries around the world. At high concentrations nitrate is toxic to aquatic life but at environmental concentrations it has also been purported as an endocrine disruptor in fish. To investigate the potential for nitrate to cause endocrine disruption in fish, we conducted a lifecycle study with fathead minnows (Pimephales promelas) exposed to nitrate (0, 11.3, and 56.5 mg/L (total nitrate-nitrogen (NO 3 -N)) from nitrate-exposed males both 11-KT and vitellogenin were significantly induced when compared with controls. No significant differences occurred for body mass, condition factor, or GSI among males and intersex was not observed in any of the nitrate treatments. Nitrate-exposed females also had significant increases in vitellogenin compared to controls but no significant differences for mass, condition factor, or GSI were observed in nitrate exposed groups. Estradiol was used as a positive control for vitellogenin induction. Our findings suggest that environmentally relevant nitrate levels may disrupt steroid hormone synthesis and/or metabolism in male and female fish and may have implications for fish reproduction, watershed management, and regulation of nutrient pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.