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Sample records for diphenyl cresyl phosphate

  1. Quantitation of ortho-cresyl phosphate adducts to butyrylcholinesterase in human serum by immunomagnetic-UHPLC-MS/MS

    NARCIS (Netherlands)

    Johnson, D.; Carter, M.D.; Crow, B.S.; Isenberg, S.L.; Graham, L.A.; Erol, H.A.; Watson, C.M.; Pantazides, B.G.; Schans, M.J. van der; Langenberg, J.P.; Noort, D.; Blake, T.A.; Thomas, J.D.; Johnson, R.C.

    2015-01-01

    Tri-ortho-cresyl phosphate (ToCP) is an anti-wear, flame retardant additive used in industrial lubricants, hydraulic fluids and gasoline. The neurotoxic effects of ToCP arise from the liver-activated metabolite 2-(o-cresyl)-4H-1,3,2-benzodioxaphosphoran-2-one (cresyl saligenin phosphate or CBDP),

  2. Metabolism and disposition of the flame retardant plasticizer, tri-p-cresyl phosphate, in the rat

    International Nuclear Information System (INIS)

    Kurebayashi, H.; Tanaka, A.; Yamaha, T.

    1985-01-01

    The metabolism and disposition of tri-p-cresyl phosphate (TPCP) were studied in the rat after a single oral administration of [methyl- 14 C] TPCP. At a dosage of 7.8 mg/kg, most of the administered radioactivity was excreted in the urine (41%) and feces (44%) in 7 days. For 3 days, the expiratory excretion as 14 CO 2 amounted to 18% of the radioactivity, but was reduced to 3% by treatment of the animal with neomycin. In separate rats, the biliary excretion amounted to 28% of the dose in 24 hr. At a dose of 89.6 mg/kg, the radioactivity was excreted in urine (12%) and feces (77%) in 7 days, and the expired air (6%) in 3 days. At 24, 72, and 168 hr after oral administration, the concentration of radioactivity was relatively high in adipose tissue, liver, and kidney. The major urinary metabolites were p-hydroxybenzoic acid, di-p-cresyl phosphate (DCP), and p-cresyl p-carboxyphenyl phosphate (1coDCP). The biliary metabolites were DCP, 1coDCP, and the oxidized triesters, di-p-cresyl p-carboxyphenyl phosphate (1coTPCP), and p-cresyl di-p-carboxyphenyl phosphate (2coTPCP). The main fecal metabolite was TPCP, and the others were similar to those of bile. Following oral administration, TPCP was absorbed from the intestine, distributed to the fatty tissues, and moderately metabolized to a variety of products of oxidation and dearylation of TPCP, which were then excreted in the urine, feces, bile, and expired air. The intestinal microflora appeared to play an important role in degrading biliary metabolites to 14 CO 2 through the enterohepatic circulation in rats

  3. Characterization of human cytochrome P450s involved in the bioactivation of tri-Ortho-Cresyl phosphate (ToCP)

    NARCIS (Netherlands)

    Reinen, Jelle; Nematollahi, Leyla; Fidder, Alex; Vermeulen, Nico P E; Noort, Daan; Commandeur, Jan N M

    2015-01-01

    Tri-ortho-cresyl phosphate (ToCP) is a multipurpose organophosphorus compound that is neurotoxic and suspected to be involved in aerotoxic syndrome in humans. It has been reported that not ToCP itself but a metabolite of ToCP, namely, 2-(ortho-cresyl)-4H-1,2,3-benzodioxaphosphoran-2-one (CBDP), may

  4. Exposure to tri-o-cresyl phosphate detected in jet airplane passengers.

    Science.gov (United States)

    Liyasova, Mariya; Li, Bin; Schopfer, Lawrence M; Nachon, Florian; Masson, Patrick; Furlong, Clement E; Lockridge, Oksana

    2011-11-01

    The aircraft cabin and flight deck ventilation are supplied from partially compressed unfiltered bleed air directly from the engine. Worn or defective engine seals can result in the release of engine oil into the cabin air supply. Aircrew and passengers have complained of illness following such "fume events". Adverse health effects are hypothesized to result from exposure to tricresyl phosphate mixed esters, a chemical added to jet engine oil and hydraulic fluid for its anti-wear properties. Our goal was to develop a laboratory test for exposure to tricresyl phosphate. The assay was based on the fact that the active-site serine of butyrylcholinesterase reacts with the active metabolite of tri-o-cresyl phosphate, cresyl saligenin phosphate, to make a stable phosphorylated adduct with an added mass of 80 Da. No other organophosphorus agent makes this adduct in vivo on butyrylcholinesterase. Blood samples from jet airplane passengers were obtained 24-48 h after completing a flight. Butyrylcholinesterase was partially purified from 25 ml serum or plasma, digested with pepsin, enriched for phosphorylated peptides by binding to titanium oxide, and analyzed by mass spectrometry. Of 12 jet airplane passengers tested, 6 were positive for exposure to tri-o-cresyl phosphate that is, they had detectable amounts of the phosphorylated peptide FGEpSAGAAS. The level of exposure was very low. No more than 0.05 to 3% of plasma butyrylcholinesterase was modified. None of the subjects had toxic symptoms. Four of the positive subjects were retested 3 to 7 months following their last airplane trip and were found to be negative for phosphorylated butyrylcholinesterase. In conclusion, this is the first report of an assay that detects exposure to tri-o-cresyl phosphate in jet airplane travelers. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Exposure to tri-o-cresyl phosphate detected in jet airplane passengers

    International Nuclear Information System (INIS)

    Liyasova, Mariya; Li, Bin; Schopfer, Lawrence M.; Nachon, Florian; Masson, Patrick; Furlong, Clement E.; Lockridge, Oksana

    2011-01-01

    The aircraft cabin and flight deck ventilation are supplied from partially compressed unfiltered bleed air directly from the engine. Worn or defective engine seals can result in the release of engine oil into the cabin air supply. Aircrew and passengers have complained of illness following such “fume events”. Adverse health effects are hypothesized to result from exposure to tricresyl phosphate mixed esters, a chemical added to jet engine oil and hydraulic fluid for its anti-wear properties. Our goal was to develop a laboratory test for exposure to tricresyl phosphate. The assay was based on the fact that the active-site serine of butyrylcholinesterase reacts with the active metabolite of tri-o-cresyl phosphate, cresyl saligenin phosphate, to make a stable phosphorylated adduct with an added mass of 80 Da. No other organophosphorus agent makes this adduct in vivo on butyrylcholinesterase. Blood samples from jet airplane passengers were obtained 24–48 h after completing a flight. Butyrylcholinesterase was partially purified from 25 ml serum or plasma, digested with pepsin, enriched for phosphorylated peptides by binding to titanium oxide, and analyzed by mass spectrometry. Of 12 jet airplane passengers tested, 6 were positive for exposure to tri-o-cresyl phosphate that is, they had detectable amounts of the phosphorylated peptide FGEpSAGAAS. The level of exposure was very low. No more than 0.05 to 3% of plasma butyrylcholinesterase was modified. None of the subjects had toxic symptoms. Four of the positive subjects were retested 3 to 7 months following their last airplane trip and were found to be negative for phosphorylated butyrylcholinesterase. In conclusion, this is the first report of an assay that detects exposure to tri-o-cresyl phosphate in jet airplane travelers. -- Highlights: ► Travel on jet airplanes is associated with an illness, aerotoxic syndrome. ► A possible cause is exposure to tricresyl phosphate in engine lubricating oil. ► A blood

  6. Exposure to tri-o-cresyl phosphate detected in jet airplane passengers

    Energy Technology Data Exchange (ETDEWEB)

    Liyasova, Mariya, E-mail: mliyasov@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Department of Environmental, Agricultural, and Occupational Health, University of Nebraska Medical Center, Omaha, NE (United States); Li, Bin, E-mail: binli@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Schopfer, Lawrence M., E-mail: lmschopf@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Nachon, Florian, E-mail: fnachon@nachon.net [Departement de Toxicologie, Institut de Recherche Biomedicale des Armees, 24 avenue des Marquis du Gresivaudan, 38702 La Tronche (France); Masson, Patrick, E-mail: pmasson@unmc.edu [Departement de Toxicologie, Institut de Recherche Biomedicale des Armees, 24 avenue des Marquis du Gresivaudan, 38702 La Tronche (France); Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Furlong, Clement E., E-mail: clem@uw.edu [Department of Medicine (Div. Medical Genetics) and Genome Sciences, University of Washington, Seattle, WA 98195 (United States); Lockridge, Oksana, E-mail: olockrid@unmc.edu [Eppley Institute, University of Nebraska Medical Center, Omaha, NE 68198-5950 (United States); Department of Environmental, Agricultural, and Occupational Health, University of Nebraska Medical Center, Omaha, NE (United States)

    2011-11-15

    The aircraft cabin and flight deck ventilation are supplied from partially compressed unfiltered bleed air directly from the engine. Worn or defective engine seals can result in the release of engine oil into the cabin air supply. Aircrew and passengers have complained of illness following such 'fume events'. Adverse health effects are hypothesized to result from exposure to tricresyl phosphate mixed esters, a chemical added to jet engine oil and hydraulic fluid for its anti-wear properties. Our goal was to develop a laboratory test for exposure to tricresyl phosphate. The assay was based on the fact that the active-site serine of butyrylcholinesterase reacts with the active metabolite of tri-o-cresyl phosphate, cresyl saligenin phosphate, to make a stable phosphorylated adduct with an added mass of 80 Da. No other organophosphorus agent makes this adduct in vivo on butyrylcholinesterase. Blood samples from jet airplane passengers were obtained 24-48 h after completing a flight. Butyrylcholinesterase was partially purified from 25 ml serum or plasma, digested with pepsin, enriched for phosphorylated peptides by binding to titanium oxide, and analyzed by mass spectrometry. Of 12 jet airplane passengers tested, 6 were positive for exposure to tri-o-cresyl phosphate that is, they had detectable amounts of the phosphorylated peptide FGEpSAGAAS. The level of exposure was very low. No more than 0.05 to 3% of plasma butyrylcholinesterase was modified. None of the subjects had toxic symptoms. Four of the positive subjects were retested 3 to 7 months following their last airplane trip and were found to be negative for phosphorylated butyrylcholinesterase. In conclusion, this is the first report of an assay that detects exposure to tri-o-cresyl phosphate in jet airplane travelers. -- Highlights: Black-Right-Pointing-Pointer Travel on jet airplanes is associated with an illness, aerotoxic syndrome. Black-Right-Pointing-Pointer A possible cause is exposure to

  7. Biodegradation of tert-butylphenyl diphenyl phosphate

    International Nuclear Information System (INIS)

    Heitkamp, M.A.; Freeman, J.P.; Cerniglia, C.E.

    1986-01-01

    The biodegradation of tert-butylphenyl diphenyl phosphate (BPDP) was examined in microcosms containing sediment and water from five different ecosystems as part of studies to elucidate the environmental fate of phosphate ester flame retardants. Biodegradation of [ 14 C]BPDP was monitored in the environmental microcosms by measuring the evolution of 14 CO 2 . Over 37% of BPDP was mineralized after 8 weeks in microcosms from an ecosystem which had chronic exposure to agricultural chemicals. In contrast, only 1.7% of BPDP was degraded to 14 CO 2 in samples collected from a noncontaminated site. The exposure concentration of BPDP affected the percentage which was degraded to 14 CO 2 in microcosms from the two most active ecosystems. Mineralization was highest at a concentration of 0.1 mg of BPDP and was inhibited with 10- and 100-fold higher concentrations of BPDP. The authors observed adaptive increases in both microbial populations and phosphoesterase enzymes in some sediments acclimated to BPDP. Chemical analyses of the residues in the microcosms indicated undegraded BPDP and minor amounts of phenol, tert-butylphenol, diphenyl phosphate, and triphenyl phosphate as biodegradation products. These data suggest that the microbial degradation of BPDP results from at least three catabolic processes and is highest when low concentrations of BPDP are exposed to sediment microorganisms of eutrophic ecosystems which have high phosphotri- and diesterase activities and previous exposure to anthropogenic chemicals

  8. Associations between urinary diphenyl phosphate and thyroid function.

    Science.gov (United States)

    Preston, Emma V; McClean, Michael D; Claus Henn, Birgit; Stapleton, Heather M; Braverman, Lewis E; Pearce, Elizabeth N; Makey, Colleen M; Webster, Thomas F

    2017-04-01

    Triphenyl phosphate (TPHP) is a commonly used organophosphate flame retardant and plasticizer with widespread human exposure. Data on health effects of TPHP are limited. Recent toxicological studies suggest TPHP may alter thyroid function. We used repeated measures to assess the temporal variability in urinary concentrations of the TPHP metabolite, diphenyl phosphate (DPHP), and to examine relationships between DPHP concentrations and thyroid hormones. We sampled 51 adults at months 1, 6, and 12 from 2010 to 2011. Urine samples were analyzed for DPHP. Serum samples were analyzed for free and total thyroxine (fT 4 , TT 4 ), total triiodothyronine (TT 3 ), and thyroid stimulating hormone (TSH). We assessed variability in DPHP using intraclass correlation coefficients (ICCs) and kappa statistics. We used linear mixed-effects models to examine associations between DPHP and thyroid hormones. DPHP was detected in 95% of urine samples. Mean DPHP concentrations were 43% higher in women than men. DPHP showed high within-subject variability (ICC range, 0.13-0.39; kappa range, 0.16-0.39). High versus low (≥2.65 vs. <2.65ng/mL) DPHP in all participants was associated with a 0.43μg/dL (95% confidence interval: 0.15, 0.72) increase in mean TT 4 levels. In sex-stratified analyses, high versus low DPHP was associated with a 0.91μg/dL (95% CI: 0.47, 1.36) increase in mean TT 4 in women. The association was attenuated in men (βeta=0.19; 95% CI: -0.15, 0.52). We found no significant associations between DPHP and fT 4 , TT 3 , or TSH. We found evidence that TPHP exposure may be associated with increased TT 4 levels, especially in women. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Corrosion inhibition of 7000 series aluminium alloys with cerium diphenyl phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Hill, Julie-Anne [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Markley, Tracey [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); CSIRO, Division of Materials Science and Technology, Clayton, Victoria (Australia); Forsyth, Maria, E-mail: maria.forsyth@deakin.edu.au [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Howlett, Patrick C. [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Hinton, Bruce R.W. [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Defence Science and Technology Organisation, Melbourne, Victoria (Australia)

    2011-02-03

    Graphical abstract: Scanning electron micrographs of microtomed surface shows pristine surface free of corrosion related 'mud cracking' inset for an inhibited AA7050 specimen when only 150 ppm Ce(dpp)3 is present in 0.1 M NaCl solution. Display Omitted Research highlights: > The thin film of hydrolysis products of Ce(dpp)3 and aluminium oxide is proposed to cause the inhibition. > The film consists of discrete Ce rich particles and a thin film over the matrix of Ce, P and Al oxides. > Discrete deposition of Ce is specifically influenced by Cu rich intermetallics. - Abstract: Cerium diphenyl phosphate (Ce(dpp){sub 3}) has previously been shown to be a strong corrosion inhibitor for aluminium-copper magnesium alloy AA2024-T3 and AA7075 in chloride solutions. Surface characterisation including SEM and ToF-SIMS coupled with electrochemical impedance spectroscopy (EIS) measurements are used to propose a mechanism of corrosion inhibition which appears to involve the formation of a complex oxide film of aluminium and cerium also incorporating the organophosphate component. The formation of a thin complex film consisting of hydrolysis products of the Ce(dpp){sub 3} compound and aluminium oxide is proposed to lead to the observed inhibition. SEM analysis shows that some intermetallics favour the creation of thicker deposits predominantly containing cerium oxide compounds.

  10. Triphenyl phosphate allergy from spectacle frames

    DEFF Research Database (Denmark)

    Carlsen, L; Andersen, K E; Egsgaard, Helge

    1986-01-01

    A case of triphenyl phosphate allergy from spectacle frames is reported. Patch tests with analytical grade triphenyl phosphate, tri-m-cresyl phosphate, and tri-p-cresyl phosphate in the concentrations 5%, 0.5% and 0.05% pet. showed positive reactions to 0.05% triphenyl phosphate and 0.5% tri......-m-cresyl phosphate, but no reaction to tri-p-cresyl phosphate. Gas chromatography of the tricresyl phosphate 5% pet. patch test material supplied from Trolab showed that it contained a mixture of a wide range of triaryl phosphates, including 0.08% triphenyl phosphate which is above the threshold for detecting...

  11. Polymerization of 5-alkyl δ-lactones catalyzed by diphenyl phosphate and their sequential organocatalytic polymerization with monosubstituted epoxides

    KAUST Repository

    Zhao, Junpeng

    2015-02-04

    Organocatalytic ring-opening polymerization (ROP) reactions of three renewable 5-alkyl δ-lactones, namely δ-hexalactone (HL), δ-nonalactone (NL) and δ-decalactone (DL), using diphenyl phosphate (DPP) were investigated. Room temperature, together with a relatively high monomer concentration (≥3 M), was demonstrated to be suitable for achieving a living ROP behavior, a high conversion of the lactone, a controlled molecular weight and a low dispersity of the polyester. HL, containing a 5-methyl substituent, showed a much higher reactivity (polymerization rate) and a slightly higher equilibrium conversion than the compounds with longer alkyl substituents (NL and DL). The effectiveness of DPP-catalyzed ROP of 5-alkyl δ-lactones facilitated the one-pot performance following the t-BuP4-promoted ROP of monosubstituted epoxides. It has been shown in an earlier study that substituted polyethers acted as "slow initiators" for non-substituted lactones. However, efficient initiations were observed in the present study as substituted lactones were polymerized from the substituted polyethers. Therefore, this reinforces the previously developed "catalyst switch" strategy, making it a more versatile tool for the synthesis of well-defined polyether-polyester block copolymers from a large variety of epoxide and lactone monomers. © The Royal Society of Chemistry 2015.

  12. Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate/acrylonitrile-butadiene-styrene blends

    International Nuclear Information System (INIS)

    Pawlowski, Kristin H.; Schartel, Bernhard; Fichera, Mario A.; Jaeger, Christian

    2010-01-01

    Bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic-organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved.

  13. p-Cresyl sulfate and indoxyl sulfate in pediatric patients on chronic dialysis

    Directory of Open Access Journals (Sweden)

    Hye Sun Hyun

    2013-04-01

    Full Text Available &lt;b&gt;Purpose:&lt;/b&gt; Indoxyl sulfate and p- cresyl sulfate are important protein-bound uremic retention solutes whose levels can be partially reduced by renal replacement therapy. These solutes originate from intestinal bacterial protein fermentation and are associated with cardiovascular outcomes and chronic kidney disease progression. The aims of this study were to investigate the levels of indoxyl sulfate and p- cresyl sulfate as well as the effect of probiotics on reducing the levels of uremic toxins in pediatric patients on dialysis. &lt;b&gt;Methods:&lt;/b&gt; We enrolled 20 pediatric patients undergoing chronic dialysis; 16 patients completed the study. The patients underwent a 12-week regimen of VSL#3, a high-concentration probiotic preparation, and the serum levels of indoxyl sulfate and p- cresyl sulfate were measured before treatment and at 4, 8, and 12 weeks after the regimen by using fluorescence liquid chromatography. To assess the normal range of indoxyl sulfate and p- cresyl sulfate we enrolled the 16 children with normal glomerular filtration rate who had visited an outpatient clinic for asymptomatic microscopic hematuria that had been detected by a school screening in August 2011. &lt;b&gt;Results:&lt;/b&gt; The baseline serum levels of indoxyl sulfate and p- cresyl sulfate in the patients on chronic dialysis were significantly higher than those in the children with microscopic hematuria. The baseline serum levels of p- cresyl sulfate in the peritoneal dialysis group were significantly higher than those in the hemodialysis group. There were no significant changes in the levels of these uremic solutes after 12-week VSL#3 treatment in the patients on chronic dialysis. &lt;b&gt;Conclusion:&lt;/b&gt; The levels of the uremic toxins p- cresyl sulfate and indoxyl sulfate are highly elevated in pediatric patients on dialysis, but there was no significant effect by

  14. Effect of milrinone on the developmental competence of growing lamb oocytes identified with brilliant cresyl blue.

    Science.gov (United States)

    Wang, Liqin; Jiang, Xiangjiu; Wu, Yangsheng; Lin, Jiapeng; Zhang, Li; Yang, Nan; Huang, Juncheng

    2016-11-01

    Juvenile in vitro embryo transfer is a novel technique that can be used to increase the rate of genetic gain in a population and presents an alternative to embryo technologies on the basis of adult animals. However, oocytes from prepubertal animals have a lower viability than those obtained from adult ewe oocyte donors. In this research, we aimed to determine the optimum concentration and time of treatment of oocytes from prepubertal lambs with brilliant cresyl blue (BCB) stain and milrinone during IVM. This would improve the developmental rate of lamb oocytes and embryos after IVF. First, lamb cumulus-oocyte complexes were cultured under different concentrations (13 or 26 μM) of BCB staining. Treated lamb oocytes were then divided into BCB- (colorless cytoplasm) and BCB+ (colored cytoplasm) groups on the basis of their glucose-6-phosphate dehydrogenase activity. The blastocyst efficiency rate of BCB+ oocytes treated with 13 μM BCB (37.03%) was significantly higher than that of BCB+ oocytes treated with 26 μM BCB (23.25%) and that of nontreated BCB control oocytes (15.37%), as well as that of BCB- oocytes (6.28%). Both control oocytes and BCB+ oocytes exhibited significantly higher cleavage rates (60.15% and 73.44%, respectively) than that of BCB- oocytes (36.19%). Moreover, the diameter and glutathione content of BCB+ oocytes were found to be significantly greater than those of BCB- oocytes (163.37 vs. 159.25 μm and 6.39 vs. 0.26 pM, respectively). After culturing BCB- oocytes in different concentrations of milrinone (0, 50, 75, and 100 μM) for 3, 6, or 9 hours, results reported that supplementation of IVM medium with 75 μM milrinone for 6 hours yielded a significantly higher proportion of blastocysts than the other treatments. These results show that the staining of lamb cumulus-oocyte complexes with 13 μM BCB before IVM may be used to select developmentally competent lamb oocytes. Furthermore, they suggest that milrinone can be used to promote

  15. One electron reduction and absorption characteristics of Cresyl violet in micellar medium

    International Nuclear Information System (INIS)

    Gawandi, Vijay B.; Guha, S.N.; Hari Mohan

    2000-01-01

    Effect of surfactant micelles on absorption characteristics of Cresyl violet (CV) and on its redox reactions have been studied. Among the various surfactants investigated anionic surfactants particularly sodium lauryl sulfate (SLS) and sodium dodecyl benzene sulfonate (SDDBS) showed marked effect on these properties. Reactions of hydrated electron in these micellar media were studied using the technique of nanosecond pulse radiolysis. Results of other surfactants, viz.BSS, CTAB and TritonX-100 have also been presented. (author)

  16. Heritability and clinical determinants of serum indoxyl sulfate and p-cresyl sulfate, candidate biomarkers of the human microbiome enterotype.

    Directory of Open Access Journals (Sweden)

    Liesbeth Viaene

    Full Text Available BACKGROUND: Indoxyl sulfate and p-cresyl sulfate are unique microbial co-metabolites. Both co-metabolites have been involved in the pathogenesis of accelerated cardiovascular disease and renal disease progression. Available evidence suggests that indoxyl sulfate and p-cresyl sulfate may be considered candidate biomarkers of the human enterotype and may help to explain the link between diet and cardiovascular disease burden. OBJECTIVE AND DESIGN: Information on clinical determinants and heritability of indoxyl sulfate and p-cresyl sulfate serum is non-existing. To clarify this issue, the authors determined serum levels of indoxyl sulfate and p-cresyl sulfate in 773 individuals, recruited in the frame of the Flemish Study on Environment, Genes and Health Outcomes (FLEMENGHO study. RESULTS: Serum levels of indoxyl sulfate and p-cresyl sulfate amounted to 3.1 (2.4-4.3 and 13.0 (7.4-21.5 μM, respectively. Regression analysis identified renal function, age and sex as independent determinants of both co-metabolites. Both serum indoxyl sulfate (h2 = 0.17 and p-cresyl sulfate (h2 = 0.18 concentrations showed moderate but significant heritability after adjustment for covariables, with significant genetic and environmental correlations for both co-metabolites. LIMITATIONS: Family studies cannot provide conclusive evidence for a genetic contribution, as confounding by shared environmental effects can never be excluded. CONCLUSIONS: The heritability of indoxyl sulfate and p-cresyl sulfate is moderate. Besides genetic host factors and environmental factors, also renal function, sex and age influence the serum levels of these co-metabolites.

  17. Effects of chlorine and its cresylate byproducts on brain and lung performance.

    Science.gov (United States)

    Kilburn, Kaye H

    2003-12-01

    Chlorine and potassium cresylate spilled from a train wreck forced evacuation of nearly 1000 people in and near the town of Alberton, Montana, in 1996. Because respiratory and other symptoms persisted in this population, neurobehavioral and pulmonary functions were evaluated in a cohort of exposed vs. unexposed individuals. Ninety-seven subjects were tested 7 wk after exposure. Three years later, 36 of the original subjects were retested, along with 21 new patients exposed in the same incident. These 57 were compared with 22 unexposed individuals. Twenty-six neurobehavioral functions were tested, and spirometry was performed on each subject. At 7 wk postexposure, patients showed significant differences in 5 neurobehavioral functions (i.e., balance, simple reaction time, abnormal visual quadrants, vocabulary, and information), compared with the unexposed individuals recruited in 1999. Patients' Profile of Mood States scores and frequencies of 35 symptoms were also elevated, compared with the unexposed group. At 3 yr postexposure, patients exhibited differences in 7 additional neurobehavioral functions (i.e., choice reaction time, balance with eyes open, color errors, visual fields, Culture Fair, and verbal recall). Respiratory symptoms were increased, but pulmonary functions did not change. Exposure to chlorine and potassium cresylate produced neurobehavioral impairments that have been observed to increase across 3 yr. Spills in heavily populated areas could injure thousands, overwhelming medical facilities.

  18. PLGA nano/microparticles loaded with cresyl violet as a tracer for drug delivery: Characterization and in-situ hyperspectral fluorescence and 2-photon localization

    Energy Technology Data Exchange (ETDEWEB)

    Lunardi, Claure N., E-mail: clunardi@unb.br [Laboratory of Photochemistry and Nanobiotechnology, University of Brasília, Brasília (Brazil); Department of Biomedical Engineering and Radiology, Laboratory for Functional Optical Imaging, Columbia University, New York, NY (United States); Gomes, Anderson J. [Laboratory of Photochemistry and Nanobiotechnology, University of Brasília, Brasília (Brazil); Department of Biomedical Engineering and Radiology, Laboratory for Functional Optical Imaging, Columbia University, New York, NY (United States); Palepu, Sandeep; Galwaduge, P. Thilanka; Hillman, Elizabeth M.C. [Department of Biomedical Engineering and Radiology, Laboratory for Functional Optical Imaging, Columbia University, New York, NY (United States)

    2017-01-01

    Here we present the production, characterization and in-vivo assessment of cresyl violet-loaded biodegradable PLGA nano/microparticles (CV-NP and CV-MP). We demonstrate that the beneficial spectral characteristics of cresyl violet make it suitable as a tracer for particle-based drug delivery using both hyperspectral wide field and two-photon excited fluorescence microscopy. Particles were prepared using a cosolvent method, after which the physicochemical properties such as morphology, particle size, drug entrapment efficiency, drug loading and in vitro drug release behavior were measured in addition to spectroscopic properties, such as absorption, fluorescence and infrared spectra. The particles were then tested in an in vivo mouse model to assess their biodistribution characteristics. The location and integrity of particles after injection was determined using both hyperspectral fluorescence and two-photon microscopy within intact organs in situ. Our results show that cresyl violet is efficiently entrapped into PLGA particles, and that the particles are spherical in shape, ranging from 300 to 5070 nm in diameter. Particle biodistribution in the mouse was found to depend on particle size, as expected. Cresyl violet is shown to be an ideal tracer to assess the properties PLGA particle-based drug delivery in combination with our novel multi-scale optical imaging techniques for in-situ particle localization. - Highlights: • Cresyl violet entrapment into polymeric particles • Cresyl violet suitable as a tracer for particle-based drug delivery • Hyperspectral analysis of polymer nano/microparticles • Two-photon microscopy of polymeric nano/microparticles.

  19. Fluorescence, Decay Time, and Structural Change of Laser Dye Cresyl Violet in Solution due to Microwave Irradiation at GSM 900/1800 Mobile Phone Frequencies

    Directory of Open Access Journals (Sweden)

    Fuat Bayrakceken

    2012-01-01

    Full Text Available Microwave irradiation at GSM 900/1800 MHz mobile phone frequencies affects the electronic structure of cresyl violet in solution. These changes are important because laser-dye cresyl violet strongly bonds to DNA- and RNA-rich cell compounds in nerve tissues. The irradiation effects on the electronic structure of cresyl violet and its fluorescence data were all obtained experimentally at room temperature. For most laser dyes, this is not a trivial task because laser dye molecules possess a relatively complex structure. They usually consist of an extended system of conjugated double or aromatic π-bonds with attached auxochromic (electron donating groups shifting the absorption band further towards longer wavelength. Because of the intrinsically high degree of conjugation, the vibrational modes of the molecular units couple strongly with each other. We found that the fluorescence quantum yield was increased from to due to intramolecular energy hopping of cresyl violet in solution which is exposed to microwave irradiation at mobile phone frequencies, and the photonic product cannot be used as a laser dye anymore.

  20. Effects of intestinal bacteria-derived p-cresyl sulfate on Th1-type immune response in vivo and in vitro

    International Nuclear Information System (INIS)

    Shiba, Takahiro; Kawakami, Koji; Sasaki, Takashi; Makino, Ikuyo; Kato, Ikuo; Kobayashi, Toshihide; Uchida, Kazumi; Kaneko, Kimiyuki

    2014-01-01

    Protein fermentation by intestinal bacteria generates various compounds that are not synthesized by their hosts. An example is p-cresol, which is produced from tyrosine. Patients with chronic kidney disease (CKD) accumulate high concentrations of intestinal bacteria-derived p-cresyl sulfate (pCS), which is the major metabolite of p-cresol, in their blood, and this accumulation contributes to certain CKD-associated disorders. Immune dysfunction is a CKD-associated disorder that frequently contributes to infectious diseases among CKD patients. Although some studies imply pCS as an etiological factor, the relation between pCS and immune systems is poorly understood. In the present study, we investigated the immunological effects of pCS derived from intestinal bacteria in mice. For this purpose, we fed mice a tyrosine-rich diet that causes the accumulation of pCS in their blood. The mice were shown to exhibit decreased Th1-driven 2, 4-dinitrofluorobenzene-induced contact hypersensitivity response. The concentration of pCS in blood was negatively correlated with the degree of the contact hypersensitivity response. In contrast, the T cell-dependent antibody response was not influenced by the accumulated pCS. We also examined the in vitro cytokine responses by T cells in the presence of pCS. The production of IFN-γ was suppressed by pCS. Further, pCS decreased the percentage of IFN-γ-producing Th1 cells. Our results suggest that intestinal bacteria-derived pCS suppressesTh1-type cellular immune responses. - Highlights: • Mice fed a tyrosine-rich diet accumulated p-cresyl sulfate in their blood. • p-Cresyl sulfate negatively correlated with contact hypersensitivity response. • The in vitro production of IFN-γ was suppressed by p-cresyl sulfate. • p-Cresyl sulfate decreased the percentage of IFN-γ-producing Th1 cells in vitro

  1. Effects of intestinal bacteria-derived p-cresyl sulfate on Th1-type immune response in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Shiba, Takahiro, E-mail: takahiro-shiba@yakult.co.jp; Kawakami, Koji; Sasaki, Takashi; Makino, Ikuyo; Kato, Ikuo; Kobayashi, Toshihide; Uchida, Kazumi; Kaneko, Kimiyuki

    2014-01-15

    Protein fermentation by intestinal bacteria generates various compounds that are not synthesized by their hosts. An example is p-cresol, which is produced from tyrosine. Patients with chronic kidney disease (CKD) accumulate high concentrations of intestinal bacteria-derived p-cresyl sulfate (pCS), which is the major metabolite of p-cresol, in their blood, and this accumulation contributes to certain CKD-associated disorders. Immune dysfunction is a CKD-associated disorder that frequently contributes to infectious diseases among CKD patients. Although some studies imply pCS as an etiological factor, the relation between pCS and immune systems is poorly understood. In the present study, we investigated the immunological effects of pCS derived from intestinal bacteria in mice. For this purpose, we fed mice a tyrosine-rich diet that causes the accumulation of pCS in their blood. The mice were shown to exhibit decreased Th1-driven 2, 4-dinitrofluorobenzene-induced contact hypersensitivity response. The concentration of pCS in blood was negatively correlated with the degree of the contact hypersensitivity response. In contrast, the T cell-dependent antibody response was not influenced by the accumulated pCS. We also examined the in vitro cytokine responses by T cells in the presence of pCS. The production of IFN-γ was suppressed by pCS. Further, pCS decreased the percentage of IFN-γ-producing Th1 cells. Our results suggest that intestinal bacteria-derived pCS suppressesTh1-type cellular immune responses. - Highlights: • Mice fed a tyrosine-rich diet accumulated p-cresyl sulfate in their blood. • p-Cresyl sulfate negatively correlated with contact hypersensitivity response. • The in vitro production of IFN-γ was suppressed by p-cresyl sulfate. • p-Cresyl sulfate decreased the percentage of IFN-γ-producing Th1 cells in vitro.

  2. Model for Photodegradation of Polybrominated Diphenyl Ethers

    Czech Academy of Sciences Publication Activity Database

    Veselý, M.; Vajglová, Zuzana; Kotas, Petr; Křišťál, Jiří; Ponec, Robert; Jiřičný, Vladimír

    2015-01-01

    Roč. 22, č. 7 (2015), s. 4949-4963 ISSN 0944-1344 R&D Projects: GA ČR GA104/09/0880; GA ČR(CZ) GAP105/12/0664 Institutional support: RVO:67985858 ; RVO:67179843 Keywords : polybrominated diphenyl ethers * photodegradation model * quantum chemical calculation Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 2.760, year: 2015

  3. Promoting environmentally sound management of polybrominated diphenyl ethers in Asia.

    Science.gov (United States)

    Li, Jinhui; Zhao, Nana; Liu, Xue; Wu, Xiaoyang

    2014-06-01

    Polybrominated diphenyl ethers with persistent organic pollutant properties are required to be controlled by the Stockholm Convention. Recently, polybrominated diphenyl ether contamination has become widespread in Asia, mainly because of the disposal and recycling processes of polybrominated diphenyl ether-containing wastes. The management status, production, usage, import/export, treatment, and disposal, as well as implementation deficiencies for the environmentally sound management of polybrominated diphenyl ethers and polybrominated diphenyl ether-containing materials in ten Asian countries were investigated and assessed in this study. This information could help the participating countries implement the Stockholm Convention and could promote the regional environmentally sound management of polybrominated diphenyl ether-containing articles and products. The results obtained were as follows. (1) Most of the countries studied lacked environmental policies and regulations, or even standards of polybrominated diphenyl ether pollution management and emission control actions. Accurate data on the consumption and importation of polybrominated diphenyl ether-containing materials, however, were not available for all the participating countries. In addition, there were no special treatment or disposal systems for polybrominated diphenyl ether-containing materials, or emission-cutting measures for the treatment of waste in these countries, owing to the lack of sufficient funding or technologies. (2) The improper dismantling of e-waste is a major source of polybrominated diphenyl ether emissions in these countries. (3) Proper e-waste management could result in a breakthrough in the environmentally sound management of this major polybrominated diphenyl ether-containing material flow, and could significantly reduce polybrominated diphenyl ether emissions. Finally, based on the study results, this article puts forward some recommendations for improving the environmentally

  4. Phosphate Salts

    Science.gov (United States)

    ... body. They are involved in cell structure, energy transport and storage, vitamin function, and numerous other processes ... Phosphate-containing foods and beverages include cola, wine, beer, whole grain cereals, nuts, dairy products and some ...

  5. An Exposure Assessment of Polybrominated Diphenyl Ethers ...

    Science.gov (United States)

    EPA announced the availability of the final report, An Exposure Assessment of Polybrominated Diphenyl Ethers. This report provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document address: the production, use, and lifecycle of PBDEs; environmental fate; environmental levels; and human exposure. This final report addresses the exposure assessment needs identified in the OPBDE Workgroup project plan. It provides a comprehensive assessment of the exposure of Americans to this class of persistent organic pollutants. Individual chapters in this document address: the production, use, and lifecycle of PBDEs; environmental fate; environmental levels; and human exposure.

  6. An experimental and theoretical method for determination of standard electrode potential for the redox couple diphenyl sulfone/diphenyl sulfide

    Science.gov (United States)

    Song, Y. Z.; Wei, K. X.; Lv, J. S.

    2013-12-01

    DFT calculations were performed for diphenyl sulfide and diphenyl sulfone. The electrochemistry of diphenyl sulfide on the gold electrode was investigated by cyclic voltammety and the results show that standard electrode potential for redox couple diphenyl sulfone/diphenyl sulfide is 1.058 V, which is consistent with that of 1.057 calculated at B3LYP/6-31++G( d, p)-IEFPCM level. The front orbit theory and Mulliken charges of molecular explain well on the oxidation of diphenyl sulfide in oxidative desulfurization. According to equilibrium theory the experimental equilibrium constant in the oxidative desulfurization of H2O2, is 1.17 × 1048, which is consistent with the theoretical equilibrium constant is 2.18 × 1048 at B3LYP/6-31++G( d, p)-IEFPCM level.

  7. Spatial trends of polybrominated diphenyl ether (PBDE) congeners

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial trends of polybrominated diphenyl ether (PBDE) congeners were analyzed in young of the year bluefish collected along the U.S. Atlantic coastline from...

  8. Determination of tricresyl phosphate air contamination in aircraft.

    Science.gov (United States)

    Denola, G; Hanhela, P J; Mazurek, W

    2011-08-01

    Monitoring of tricresyl phosphate (TCP) contamination of cockpit air was undertaken in three types of military aircraft [fighter trainer (FT), fighter bomber (FB), and cargo transport (CT) aircraft]. The aircraft had a previous history of pilot complaints about cockpit air contamination suspected to originate from the engine bleed air supply through the entry of aircraft turbine engine oil (ATO) into the engine compressor. Air samples were collected in flight and on the ground during engine runs using sorbent tubes packed with Porapak Q and cellulose filters. A total of 78 air samples were analysed, from 46 different aircraft, and 48 samples were found to be below the limit of detection. Nine incidents of smoke/odour were identified during the study. The concentrations of toxic o-cresyl phosphate isomers were below the level of detection in all samples. The highest total TCP concentration was 51.3 μg m(-3), while most were generally found to be contamination of cabin/cockpit air has been the subject of much concern in aviation, quantitative data are sparse.

  9. Design and synthesis of novel diphenyl oxalamide and diphenyl acetamide derivatives as anticonvulsants.

    Science.gov (United States)

    Nikalje, Anna Pratima G; Ghodke, Mangesh; Girbane, Amol

    2012-01-01

    A series of novel N(1) -substituted-N(2) ,N(2) -diphenyl oxalamides 3a-l were synthesized in good yield by stirring diphenylcarbamoyl formyl chloride (2) and various substituted aliphatic, alicyclic, aromatic, heterocyclic amines in DMF and K(2) CO(3) . Also 2-substituted amino-N,N-diphenylacetamides 5a-m were designed by pharmacophore generation and synthesized by stirring 2-chloro-N,N-diphenylacetamide (4) and various substituted amines in acetone using triethyl amine as a catalyst. All the synthesized compounds were screened for anticonvulsant activity in Swiss albino mice by MES and ScPTZ induced seizure tests. Neurotoxicity screening and behavioral testing was also carried out. Some of the synthesized test compounds were found to be more potent than the standard drug. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Effects of diphenyl and p-chloro-diphenyl diselenides on feeding behavior of rats.

    Science.gov (United States)

    Bortolatto, Cristiani F; Heck, Suélen O; Gai, Bibiana M; Zborowski, Vanessa A; Neto, José S S; Nogueira, Cristina W

    2015-07-01

    The searching for safe and effective antiobesity drugs has been the subject of intense research. Previous studies have shown several pharmacological applications of organoselenium compounds; however, their possible anorectic-like actions have not been investigated. This study aims to investigate the effects of (PhSe)2 and (p-ClPhSe)2 on feeding behavior of rats and their potential as weight-reducing agents. The effects of intraperitoneal administration of diselenides were investigated through the microstructural pattern of feeding behavior, behavioral satiety sequence (BSS), hypothalamic serotonin (5-HT) uptake, body weight, and epididymal fat content of male rats. Our findings demonstrated that food intake of fasted rats was reduced by both diselenides (1 and 10 mg/kg). Diphenyl diselenide [(PhSe)2] (1 mg/kg) and p-chloro-diphenyl diselenide [(p-ClPhSe)2] (10 mg/kg) decreased the frequency, mean duration, and mean size of meals compared with the control treatment. The BSS structure was preserved when organoselenium compounds (1 mg/kg) were administered, and it was associated to a displacement to the left when the resting period started indicating a satiating action. Inhibition of 5-HT uptake in the hypothalamus (∼20 %) was also found in rats treated with low doses of (PhSe)2 and (p-ClPhSe)2 (1 mg/kg). Treatments with a high dose of both diselenides (10 mg/kg) carried out for 7 days induced weight loss and epididymal fat reduction in sated rats. This study suggests that diselenides caused a satiating action in rats that could be partially explained by the inhibition of hypothalamic 5-HT uptake. These organoselenium compounds were potential weight-reducing agents when repeatedly administered.

  11. Towards Phosphate Detection in Hydroponics Using Molecularly Imprinted Polymer Sensors.

    Science.gov (United States)

    Storer, Christopher S; Coldrick, Zachary; Tate, Daniel J; Donoghue, Jack Marsden; Grieve, Bruce

    2018-02-10

    An interdigitated electrode sensor was designed and microfabricated for measuring the changes in the capacitance of three phosphate selective molecularly imprinted polymer (MIP) formulations, in order to provide hydroponics users with a portable nutrient sensing tool. The MIPs investigated were synthesised using different combinations of the functional monomers methacrylic acid (MAA) and N -allylthiourea, against the template molecules diphenyl phosphate, triethyl phosphate, and trimethyl phosphate. A cross-interference study between phosphate, nitrate, and sulfate was carried out for the MIP materials using an inductance, capacitance, and resistance (LCR) meter. Capacitance measurements were taken by applying an alternating current (AC) with a potential difference of 1 V root mean square (RMS) at a frequency of 1 kHz. The cross-interference study demonstrated a strong binding preference to phosphate over the other nutrient salts tested for each formulation. The size of template molecule and length of the functional monomer side groups also determined that a short chain functional monomer in combination with a template containing large R-groups produced the optimal binding site conditions when synthesising a phosphate selective MIP.

  12. Thermodynamic properties of 4-tert-butyl-diphenyl oxide

    International Nuclear Information System (INIS)

    Druzhinina, A.I.; Pimenova, S.M.; Tarazanov, S.V.; Nesterova, T.N.; Varushchenko, R.M.

    2015-01-01

    Highlights: • The sample of the 4-tert-butyl-diphenyl oxide was synthesized and purified. • Heat capacities, energy of combustion, saturation vapor pressures were measured. • The temperature, the enthalpy and the entropy of fusion were determined. • The enthalpy of sublimation at T = 298.15 K was derived. • The main thermodynamic functions and functions of formation were computed. - Abstract: The main thermodynamic functions (changes of the entropy, enthalpy, and Gibbs free energy) and functions of formation at T = 298.15 K of 4-tert-butyl-diphenyl oxide in condensed and ideal gas states were computed on the basis of experimental results obtained. The heat capacities of 4-tert-butyl-diphenyl oxide was measured by vacuum adiabatic calorimetry over the temperature range (8 to 371) K. The temperature, the enthalpy and the entropy of fusion were determined. The energy of combustion of the sample was determined by static-bomb combustion calorimetry. The saturation vapor pressures of the substance were measured by dynamic transpiration method over the temperature and pressure intervals (298 to 325) K and (0.05 to 1.2) Pa. The enthalpy of sublimation at T = 298.15 K was derived. The contribution of O-(2C b ) group (where C b is the carbon atom in a benzene ring) into the absolute entropies of diphenyl oxide derivatives was assessed

  13. O interactions in 1,3-diphenyl-urea

    Indian Academy of Sciences (India)

    The synthesis, X-ray structure and role of intermolecular interactions have been studied in case of 1,3-diphenyl-urea, owing to its medicinal importance. The compound crystallizes in orthorhombic crystal system (space group, 21) with unit cell parameters, = 9.118(3), = 10.558(2), = 11.780(3) Å and = 4.

  14. Uranium from phosphate ores

    International Nuclear Information System (INIS)

    Hurst, F.J.

    1983-01-01

    The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant

  15. Synthesis of hydroxylated and methoxylated polybrominated diphenyl ethers

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ke-wen; GAO Li-ping; CAO Jie; YU Hai-wen; ZHANG Zhang

    2009-01-01

    Hydroxylated/methoxylated polybrominated diphenyl ethers (OH/MeO-PBDEs) are not only detected as natural products, but also regarded as metabolites formed from polybrominated diphenyl ethers (PBDEs), which are widely used as flame-retardants in various materials. The aim of the present study was to synthesize authentic OH-PBDEs and MeO-PBDEs, as reference standards for environmental exploration. Twenty OH-PBDEs and their corresponding MeO-PBDEs containing three to six bromine atoms were synthesized via a trial of reactions including coupling, oxidation, bromination, methylation, etc. The products were characterized by GC-MS and 1H-NMR spectroscopy in the work. As results show, all compounds synthesized were up to 99% on purity and be reqarded as authentic standards for detecting the chemical pollutants in the emvironment.

  16. Dietary protein-fiber ratio associates with circulating levels of indoxyl sulfate and p-cresyl sulfate in chronic kidney disease patients.

    Science.gov (United States)

    Rossi, M; Johnson, D W; Xu, H; Carrero, J J; Pascoe, E; French, C; Campbell, K L

    2015-09-01

    Indoxyl sulfate (IS) and p-cresyl sulfate (PCS) are uremic toxins derived solely from colonic bacterial fermentation of protein. Dietary fiber may counteract this by limiting proteolytic bacterial fermentation. However, the influence of dietary intake on the generation of IS and PCS has not been adequately explored in chronic kidney disease (CKD). This cross-sectional study included 40 CKD participants (60% male; age 69 ± 10 years; 45% diabetic) with a mean estimated glomerular filtration rate (eGFR) of 24 ± 8 mL/min/1.73 m(2), who enrolled in a randomized controlled trial of synbiotic therapy. Total and free serum IS and PCS were measured at baseline by ultra-performance liquid chromatography. Dietary intake was measured using in-depth diet histories collected by a dietitian. Associations between each toxin, dietary fiber (total, soluble and insoluble), dietary protein (total, and amino acids: tryptophan, tyrosine and phenylalanine), and the protein-fiber index (ratio of protein to fiber) were assessed using linear regression. Dietary fiber was associated with free and total serum PCS (r = -0.42 and r = -0.44, both p protein and either toxin. The protein-fiber index was associated with total serum IS (r = 0.40, p = 0.012) and PCS (r = 0.43, p = 0.005), independent of eGFR, sex and diabetes. Dietary protein-fiber index is associated with serum IS and PCS levels. Such association, beyond fiber and protein alone, highlights the importance of the interplay between these nutrients. We speculate that dietary modification towards a lower protein-fiber index may contribute to lowering IS and PCS. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Phosphate acquisition efficiency and phosphate starvation tolerance ...

    Indian Academy of Sciences (India)

    3Department of Genetics and Plant Breeding, College of Agriculture, Lembucherra, Tripura 799 ... vated in soil like red and lateritic or acid, with low soluble phosphate content. ..... activation of genes involved in the adaptation of Arabidopsis to.

  18. Zinc phosphate conversion coatings

    Science.gov (United States)

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  19. Microbial degradation of 4-monobrominated diphenyl ether with anaerobic sludge

    International Nuclear Information System (INIS)

    Shih, Yang-hsin; Chou, Hsi-Ling; Peng, Yu-Huei

    2012-01-01

    Highlights: ► BDE-3 was degraded with two anaerobes in different rates. ► Glucose addition augment the debromination efficiencies. ► Hydrogen gas was detected and relative microbes were identified. ► Extra-carbon source enhanced degradation partial due to H 2 -generation bacteria. - Abstract: Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant additives for many plastic and electronic products. Owing to their ubiquitous distribution in the environment, multiple toxicity to humans, and increasing accumulation in the environment, the fate of PBDEs is of serious concern for public safety. In this study, the degradation of 4-monobrominated diphenyl ether (BDE-3) in anaerobic sludge and the effect of carbon source addition were investigated. BDE-3 can be degraded by two different anaerobic sludge samples. The by-products, diphenyl ether (DE) and bromide ions, were monitored, indicating the reaction of debromination within these anaerobic samples. Co-metabolism with glucose facilitated BDE-3 biodegradation in terms of kinetics and efficiency in the Jhongsing sludge. Through the pattern of amplified 16S rRNA gene fragments in denatured gradient gel electrophoresis (DGGE), the composition of the microbial community was analyzed. Most of the predominant microbes were novel species. The fragments enriched in BDE-3-degrading anaerobic sludge samples are presumably Clostridium sp. This enrichment coincides with the H 2 gas generation and the facilitation of debromination during the degradation process. Findings of this study provide better understanding of the biodegradation of brominated DEs and can facilitate the prediction of the fate of PBDEs in the environment.

  20. Diphenyl-phosphinyl-morpholide (DPPM) lanthanide trifluoroacetate adducts

    International Nuclear Information System (INIS)

    Carvalho, L.R.F. de; Kim, D.J.

    1984-01-01

    Preparation and properties of adducts of lanthanide salts and diphenyl-phosphinyl-morpholide (DPPM) have been described in the literature. Addition compounds containing lanthanide nitrates, isothiocyanates, perchlorates, chlorides, bromides with DPPM have been obtained. In this article, the preparation and characterization of the addition compounds of lanthanide trifluoroacetates (TFA) with DPPM are reported. The compounds of general formula Ln (TFA) 3 . 3DPPM, Ln= La-Lu, Y were characterized by elemental analysis, melting ranges, infrared spectra, absorption and emission visible spectra, X-ray powder patterns. (Author) [pt

  1. Polybrominated diphenyl ether flame retardants in Virginia freshwater fishes (USA).

    Science.gov (United States)

    Hale, R C; La Guardia, M J; Harvey, E P; Mainor, T M; Duff, W H; Gaylor, M O

    2001-12-01

    Polybrominated diphenyl ethers (PBDEs) were examined in fish fillets collected from two large Virginia watersheds. Emphasis was on the tetra- to hexabrominated congeners since these exhibit the greatest bioaccumulation and toxicological potentials. These congeners are dominant constituents of Penta-, a commercial PBDE product used to flame retard polyurethane foam. In 1999, North America accounted for98% of global Penta-demand. Concentrations of total tetra- to hexabrominated congeners in fillets ranged from furniture and textile manufacturing, although polyurethane foam production here has been limited.

  2. Environmental analysis of higher brominated diphenyl ethers and decabromodiphenyl ethane.

    Science.gov (United States)

    Kierkegaard, Amelie; Sellström, Ulla; McLachlan, Michael S

    2009-01-16

    Methods for environmental analysis of higher brominated diphenyl ethers (PBDEs), in particular decabromodiphenyl ether (BDE209), and the recently discovered environmental contaminant decabromodiphenyl ethane (deBDethane) are reviewed. The extensive literature on analysis of BDE209 has identified several critical issues, including contamination of the sample, degradation of the analyte during sample preparation and GC analysis, and the selection of appropriate detection methods and surrogate standards. The limited experience with the analysis of deBDethane suggests that there are many commonalities with BDE209. The experience garnered from the analysis of BDE209 over the last 15 years will greatly facilitate progress in the analysis of deBDethane.

  3. Determination of polybrominated diphenyl ethers in environmental standard reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Stapleton, Heather M.; Schantz, Michele M.; Wise, Stephen A. [National Institute of Standards and Technology, Analytical Chemistry Division, Gaithersburg, MD (United States); Keller, Jennifer M.; Kucklick, John R. [National Institute of Standards and Technology, Analytical Chemistry Division, Hollings Marine Laboratory, Charleston, SC (United States); Leigh, Stefan D. [National Institute of Standards and Technology, Statistical Engineering Division, Gaithersburg, MD (United States)

    2007-04-15

    Standard reference materials (SRMs) are valuable tools in developing and validating analytical methods to improve quality assurance standards. The National Institute of Standards and Technology (NIST) has a long history of providing environmental SRMs with certified concentrations of organic and inorganic contaminants. Here we report on new certified and reference concentrations for 27 polybrominated diphenyl ether (PBDE) congeners in seven different SRMs: cod-liver oil, whale blubber, fish tissue (two materials), mussel tissue and sediment (two materials). PBDEs were measured in these SRMs, with the lowest concentrations measured in mussel tissue (SRM 1974b) and the highest in sediment collected from the New York/New Jersey Waterway (SRM 1944). Comparing the relative PBDE congener concentrations within the samples, we found the biota SRMs contained primarily tetrabrominated and pentabrominated diphenyl ethers, whereas the sediment SRMs contained primarily decabromodiphenyl ether (BDE 209). The cod-liver oil (SRM 1588b) and whale blubber (SRM 1945) materials were also found to contain measurable concentrations of two methoxylated PBDEs (MeO-BDEs). Certified and reference concentrations are reported for 12 PBDE congeners measured in the biota SRMs and reference values are available for two MeO-BDEs. Results from a sediment interlaboratory comparison PBDE exercise are available for the two sediment SRMs (1941b and 1944). (orig.)

  4. Developmental toxicity of diphenyl ether herbicides in nestling American kestrels.

    Science.gov (United States)

    Hoffman, D J; Spann, J W; LeCaptain, L J; Bunck, C M; Rattner, B A

    1991-11-01

    Beginning the day after hatching, American kestrel (Falco sparverius) nestlings were orally dosed for 10 consecutive days with 5 microliters/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorfen) at concentrations of 10, 50, 250, or 500 mg/kg in corn oil. At 500 mg/kg, nitrofen resulted in complete nestling mortality, bifenox in high (66%) mortality, and oxyfluorfen in no mortality. Nitrofen at 250 mg/kg reduced nestling growth as reflected by decreased body weight, crown-rump length, and bone lengths including humerus, radius-ulna, femur, and tibiotarsus. Bifenox at 250 mg/kg had less effect on growth than nitrofen, but crown-rump, humerus, radius-ulna, and femur were significantly shorter than controls. Liver weight as a percent of body weight increased with 50 and 250 mg/kg nitrofen. Other manifestations of impending hepatotoxicity following nitrofen ingestion included increased hepatic GSH peroxidase activity in all nitrofen-treated groups, and increased plasma enzyme activities for ALT, AST, and LDH-L in the 250-mg/kg group. Bifenox ingestion resulted in increased hepatic GSH peroxidase activity in the 50- and 250-mg/kg groups. Nitrofen exposure also resulted in an increase in total plasma thyroxine (T4) concentration. These findings suggest that altricial nestlings are more sensitive to diphenyl ether herbicides than young or adult birds of precocial species.

  5. DETERMINATION OF ALKYLATED & SULFONATED DIPHENYL OXIDE SULFACTANT BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY

    Science.gov (United States)

    Methods for the determination of the anionic surfactant Dowfax 8390 are described. Dowfax is a complex mixture of various alkylated and sulfonated diphenyl oxides. The primary component of Dowfax is monoalkylated disulfonated diphenyl oxide (MADS). This work uses ion pairing chro...

  6. 40 CFR 721.2565 - Alkylated sulfonated diphenyl oxide, alkali and amine salts.

    Science.gov (United States)

    2010-07-01

    ..., alkali and amine salts. 721.2565 Section 721.2565 Protection of Environment ENVIRONMENTAL PROTECTION... New Uses for Specific Chemical Substances § 721.2565 Alkylated sulfonated diphenyl oxide, alkali and... substances identified as alkylated sulfonated diphenyl oxide, alkali salt (PMN P-93-352) and alkylated...

  7. Polybrominated diphenyl ethers in Mississippi River suspended sediment

    Energy Technology Data Exchange (ETDEWEB)

    Raff, J.; Hites, R. [Indiana Univ., Bloomington, IN (United States)

    2004-09-15

    The Mississippi River Basin drains water from 41% of the conterminous U.S. and is a valuable resource that supplies food, transportation, and irrigation to more than 95 million people of the region. Discharge and runoff from industry, agriculture, and population centers have increased the loads of anthropogenic organic compounds in the river. There has been growing concern over the rising levels of polybrominated diphenyl ethers (PBDEs) in air, sediment, biota, and humans, but there have been no studies to measure the concentrations of these chemicals in North America's largest river system. The goal of this study was to investigate the occurrence of PBDEs (15 congeners including BDE-209) and to identify possible sources within the Mississippi River Basin. We found PBDEs to be widespread throughout the region, rivaling PCBs in their extent and magnitude of contamination. We have also calculated the total amount of PBDEs released to the Gulf of Mexico in 2002.

  8. Substance Flow Analysis of Wastes Containing Polybrominated Diphenyl Ethers

    DEFF Research Database (Denmark)

    Vyzinkarova, Dana; Brunner, Paul H.

    2013-01-01

    materials. Therefore, end-of-life (EOL) plastic materials used for construction must be separated and properly treated, for example, in a state-of-the-art municipal solid waste (MSW) incinerator. In the case of cOctaBDE, the main flows are waste electrical and electronic equipment (WEEE) and, possibly......The present article examines flows and stocks of Stockholm Convention regulated pollutants, commercial penta- and octabrominated diphenyl ether (cPentaBDE, cOctaBDE), on a city level. The goals are to (1) identify sources, pathways, and sinks of these compounds in the city of Vienna, (2) determine...... the fractions that reach final sinks, and (3) develop recommendations for waste management to ensure their minimum recycling and maximum transfer to appropriate final sinks. By means of substance flow analysis (SFA) and scenario analysis, it was found that the key flows of cPentaBDE stem from construction...

  9. Synthesis of Diphenyl Pyridazinone-based flexible system for ...

    Indian Academy of Sciences (India)

    conformational studies through weak noncovalent interactions: Application in DNA ... Single crystal structure; DFT calculation; Hirshfeld surfaces; fingerprint analysis; docking simulation; DNA ... tion properties of nucleic acids, peptides and proteins as well as ... as, (i) electrostatic attractions with the anionic sugar- phosphate ...

  10. Phosphate control in dialysis

    Directory of Open Access Journals (Sweden)

    Cupisti A

    2013-10-01

    Full Text Available Adamasco Cupisti,1 Maurizio Gallieni,2 Maria Antonietta Rizzo,2 Stefania Caria,3 Mario Meola,4 Piergiorgio Bolasco31Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy; 2Nephrology and Dialysis Unit, San Carlo Borromeo Hospital, Milan, Italy; 3Territorial Department of Nephrology and Dialysis, ASL Cagliari, Italy; 4Sant'Anna School of Advanced Studies, University of Pisa, Pisa, ItalyAbstract: Prevention and correction of hyperphosphatemia is a major goal of chronic kidney disease–mineral and bone disorder (CKD–MBD management, achievable through avoidance of a positive phosphate balance. To this aim, optimal dialysis removal, careful use of phosphate binders, and dietary phosphate control are needed to optimize the control of phosphate balance in well-nourished patients on a standard three-times-a-week hemodialysis schedule. Using a mixed diffusive–convective hemodialysis tecniques, and increasing the number and/or the duration of dialysis tecniques are all measures able to enhance phosphorus (P mass removal through dialysis. However, dialytic removal does not equal the high P intake linked to the high dietary protein requirement of dialysis patients; hence, the use of intestinal P binders is mandatory to reduce P net intestinal absorption. Unfortunately, even a large dose of P binders is able to bind approximately 200–300 mg of P on a daily basis, so it is evident that their efficacy is limited in the case of an uncontrolled dietary P load. Hence, limitation of dietary P intake is needed to reach the goal of neutral phosphate balance in dialysis, coupled to an adequate protein intake. To this aim, patients should be informed and educated to avoid foods that are naturally rich in phosphate and also processed food with P-containing preservatives. In addition, patients should preferentially choose food with a low P-to-protein ratio. For example, patients could choose egg white or protein from a vegetable source

  11. Uranium production from phosphates

    International Nuclear Information System (INIS)

    Ketzinel, Z.; Folkman, Y.

    1979-05-01

    According to estimates of the world's uranium consumption, exploitation of most rich sources is expected by the 1980's. Forecasts show that the rate of uranium consumption will increase towards the end of the century. It is therefore desirable to exploit poor sources not yet in use. In the near future, the most reasonable source for developing uranium is phosphate rock. Uranium reserves in phosphates are estimated at a few million tons. Production of uranium from phosphates is as a by-product of phosphate rock processing and phosphoric acid production; it will then be possible to save the costs incurred in crushing and dissolving the rock when calculating uranium production costs. Estimates show that the U.S. wastes about 3,000 tons of uranium per annum in phosphoric acid based fertilisers. Studies have also been carried out in France, Yugoslavia and India. In Israel, during the 1950's, a small plant was operated in Haifa by 'Chemical and Phosphates'. Uranium processes have also been developed by linking with the extraction processes at Arad. Currently there is almost no activity on this subject because there are no large phosphoric acid plants which would enable production to take place on a reasonable scale. Discussions are taking place about the installation of a plant for phosphoric acid production utilising the 'wet process', producing 200 to 250,000 tons P 2 O 5 per annum. It is necessary to combine these facilities with uranium production plant. (author)

  12. Reproductive Effects of Two Polybrominated Diphenyl Ethers on the Rotifer Brachionus plicatilis.

    Science.gov (United States)

    Zhang, Jing; Wang, You; Zhou, Bin; Sun, Kai-Ming; Tang, Xuexi

    2016-08-01

    The effects of two polybrominated diphenyl ethers (PBDEs) on the reproduction of the rotifer Brachionus plicatilis were investigated. Results showed that sexual maturation was promoted by tetra-brominated diphenyl ether-47 (BDE-47) and deca-brominated diphenyl ether-209 (BDE-209), whereas fecundity was inhibited by BDE-47, but promoted by BDE-209. Additionally, both PBDEs affected the expression of two genes, vasa and nanos mRNA, related to rotifer reproduction. This suggests a possible regulatory molecular mechanism at the transcriptional level. Our research extends the current knowledge of the ecotoxicological mechanism induced by PBDEs and provides further essential information for assessing the risks of PBDE contamination in marine ecosystems.

  13. Preparation and characterization of aliphatic diphenyl esters intended as precursors for polyesters

    DEFF Research Database (Denmark)

    Hvilsted, S.; Andruzzi, F.; Cerrai, P.

    1991-01-01

    An extensive number of aliphatic diphenyl esters, C6H5OOC(CH2)nCOOC6H5 (n = O,...,8,10,11,12,14), have been prepared in pure form. The crystalline melting points these esters exhibit an odd-even temperature behaviour, with the higher-melting even series (n even) displaying a minimum for n = 8 while...... based on similar data from phenyl esters, interpreted as the results of an apparent macrocyclic conformation of the larger diphenyl esters. High-performance size exclusion chromatography (s.e.c.) of diphenyl esters, phenyl esters, aromatic and linear hydrocarbons in tetrahydrofuran, toluene...

  14. Sorption-desorption behavior of polybrominated diphenyl ethers in soils

    International Nuclear Information System (INIS)

    Olshansky, Yaniv; Polubesova, Tamara; Vetter, Walter; Chefetz, Benny

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardants that are commonly found in commercial and household products. These compounds are considered persistent organic pollutants. In this study, we used 4,4'-dibromodiphenyl ether (BDE-15) as a model compound to elucidate the sorption and desorption behavior of PBDEs in soils. The organic carbon-normalized sorption coefficient (K OC ) of BDE-15 was more than three times higher for humin than for bulk soils. However, pronounced desorption hysteresis was obtained mainly for bulk soils. For humin, increasing concentration of sorbed BDE-15 resulted in decreased desorption. Our data illustrate that BDE-15 and probably other PBDEs exhibit high sorption affinity to soils. Moreover, sorption is irreversible and thus PBDEs can potentially accumulate in the topsoil layer. We also suggest that although humin is probably a major sorbent for PBDEs in soils, other humic materials are also responsible for their sequestration. - Highlights: → BDE-15 exhibited pronounced desorption hysteresis. → BDE-15 sowed higher sorption affinity to humin as compared to the bulk soils. → Sequestration of PBDEs depends on soil organic matter constitutes other than humin. - Pronounced desorption hysteresis was observed for BDE-15 in natural soils.

  15. Phthalates and polybrominated diphenyl ethers in retail stores

    Science.gov (United States)

    Xu, Ying; Liang, Yirui; Urquidi, Jorge R.; Siegel, Jeffrey A.

    2014-04-01

    Retail stores contain a wide range of products that can emit a variety of indoor pollutants. Among these chemicals, phthalate esters and polybrominated diphenyl ethers (PBDEs) are two important categories, because they are extensively used as additives in consumer products and associated with serious health concerns. This study measured six phthalate and 14 PBDE compounds inside of 12 retail stores in Texas and Pennsylvania, U.S. Phthalates and PBDEs were widely found in the retail environment, indicating that they are ubiquitous indoor air pollutants. DEP, DnBP, and DEHP were the most abundant phthalates, with DnBP showing the highest concentration (0.23 ± 0.36 μg m-3). PBDEs were dominated by BDE-28, -99, and -209, having concentrations as high as 0.85 ± 1.99 ng m-3 (BDE-99). The levels of phthalates and PBDEs measured in this study are comparable to concentrations found in previous investigations of residential buildings, with phthalates showing lower concentrations and PBDEs exhibiting higher concentrations in retail stores. The potential co-occurrence of phthalates was not as strong as that of PBDEs, suggesting that phthalates might have more diverse sources. Whole building emission rates were calculated and showed similar patterns of variations as indoor air concentrations, suggestion the diversity of indoor sources of phthalates and PBDEs in retail environments.

  16. Polybrominated diphenyl ethers in birds of prey from Northern China.

    Science.gov (United States)

    Chen, Da; Mai, Bixian; Song, Jie; Sun, Quanhui; Luo, Yong; Luo, Xiaojun; Zeng, Eddy Y; Hale, Robert C

    2007-03-15

    Birds of prey from Northern China (Beijing area) were examined for polybrominated diphenyl ethers (PBDEs). A total of 47 specimens from eight different species were analyzed. Muscle and liver were analyzed separately for each bird. Kidneys were pooled by species. Common kestrels exhibited the highest PBDE levels (mean muscle and liver concentrations of 12300 and 12200 ng/g lipid weight, respectively), with maxima in an individual bird of 31700 in muscle and 40900 ng/g lw in liver. Congener profiles differed between some species, but were generally dominated by the more brominated congeners (e.g., BDE-153, -209, -183, -207). BDE-209 was especially elevated compared to other published reports. Interspecies differences in congener concentrations and profiles may be due to diet, behavior, or biotransformation capacities. BDE-209 was detected in 79.4% of the samples. Common kestrels contained the highest BDE-209 levels (mean/maxima of 2150/6220 in muscle and 2870/12200 ng/g lw in liver). BDE-209 was the dominant congener in tissues from some buzzards, scops owls, and long-eared owls. It was the second most abundant congener in common kestrels. The remarkable levels and dominance of BDE-209 may relate to significant production, usage, or disposal of deca-containing products in China. These observations reinforce the growing view that organisms using terrestrial food chains may have greater exposure to BDE-209.

  17. Human exposure to polybrominated diphenyl ethers at production area, China.

    Science.gov (United States)

    Jin, Jun; Wang, Ying; Yang, Congqiao; Hu, Jicheng; Liu, Weizhi; Cui, Jian

    2010-05-01

    The concentrations of polybrominated diphenyl ethers (PBDEs) were detected in air and aquatic products in PBDEs production areas which are located at the south coast area of Laizhou Bay, Shandong province, China in this study. Concentrations of SigmaPBDEs in the air ranged from 0.47 ng/m3 to 161 ng/m3. In aquatic products, concentrations of SigmaPBDEs ranged from 2.7 ng/g wet weight to 42 ng/g wet weight. The mean dietary intake of SigmaPBDEs via aquatic products consumption in this study was 218 ng/day. Daily intake of SigmaPBDEs via inhalation in this study was 612 ng for men and 455 ng for women. With a contribution of 80%, BDE-209 was predominant in the total intake. Dietary intake and breathing inhalation contributed 29 and 71%, respectively, to the total PBDEs intake. The results indicate that breathing inhalation also plays a very significant pathway for the population of the PBDEs production area. Compared with similar studies in other countries, human exposure to PBDEs via diet and inhalation in this study was the highest in the world. Copyright (c) 2010 SETAC.

  18. Body burdens of polybrominated diphenyl ethers among urban anglers.

    Science.gov (United States)

    Morland, Kimberly B; Landrigan, Philip J; Sjödin, Andreas; Gobeille, Alayne K; Jones, Richard S; McGahee, Ernest E; Needham, Larry L; Patterson, Donald G

    2005-12-01

    Polybrominated diphenyl ethers (PBDEs) have been widely used in the United States and worldwide as flame retardants. Recent PBDE production figures show that worldwide use has increased. To determine whether fish consumption is a source of PBDE exposure for humans, a cross-sectional epidemiologic study of New York and New Jersey urban anglers was conducted during the summers of 2001-2003. Frequency of local fish consumption was assessed by questionnaire, and blood samples for PBDE analysis were collected from 94 anglers fishing from piers on the lower Hudson River and Newark Bay. We analyzed PBDEs by gas chromatography-isotope dilution-high-resolution mass spectrometry. The congeners found in anglers' serum at the highest concentrations were, by International Union of Pure and Applied Chemistry numbers, BDE-47, BDE-153, and BDE-99. Anglers reporting consumption of local fish had higher, but nonstatistically significantly different, concentrations of PBDEs than did anglers who did not eat local fish. For some congeners (BDE-100 and BDE-153), we observed moderate dose-response relationships between serum PBDE levels and frequency of reported fish intake. These findings suggest that consumption of locally caught fish is not a major route of human exposure for this study population.

  19. Uptake, translocation, and debromination of polybrominated diphenyl ethers in maize

    Institute of Scientific and Technical Information of China (English)

    Moming Zhao; Shuzhen Zhang; Sen Wang; Honglin Huang

    2012-01-01

    Uptake,translocation and debromination of three polybrominated diphenyl ethers(PBDEs),BDE-28,-47 and-99,in maize were studied in a hydroponic experiment.Roots took up most of the PBDEs in the culture solutions and more highly brominated PBDEs had a stronger uptake capability.PBDEs were detected in the stems and leaves of maize after exposure but rarely detected in the blank control plants.Furthermore,PBDE concentrations decreased from roots to stems and then to leaves,and a very clear decreasing gradient was found in segments upwards along the stem.These altogether provide substantiating evidence for the acropetal translocation of PBDEs in maize.More highly brominated PBDEs were translocated with more difficulty.Radial translocation of PBDEs from nodes to sheath inside maize was also observed.Both acropetal and radial translocations were enhanced at higher transpiration rates,suggesting that PBDE transport was probably driven by the transpiration stream.Debromination of PBDEs occurred in all parts of the maize,and debromination patterns of different parent PBDEs and in different parts of a plant were similar but with some differences.This study for the first time provides direct evidence for the acropetal translocation of PBDEs within plants,elucidates the process of PBDE transport and clarifies the debromination products of PBDEs in maize.

  20. Children's exposure to polybrominated diphenyl ethers (PBDEs) through mouthing toys.

    Science.gov (United States)

    Ionas, Alin C; Ulevicus, Jocelyn; Gómez, Ana Ballesteros; Brandsma, Sicco H; Leonards, Pim E G; van de Bor, Margot; Covaci, Adrian

    2016-02-01

    Polybrominated diphenyl ethers (PBDEs) have previously been detected in children toys, yet the risk of child exposure to these chemicals through the mouthing of toys or other items is still unknown. We aimed to expand on the current knowledge by investigating the impact of infants' mouthing activities on exposure to PBDEs present in toys. This was established by a leaching model for determining the amount PBDEs that can leach from toys into saliva in simulated conditions. The PBDE migration rate was at its highest for the 15 min low-exposure scenario incubations (198 pg/cm(2) × min) with the ERM EC-591 certified reference material (CRM) (0.17% w/w PBDEs). The leaching process was congener-dependent, since the percentage of lower brominated PBDE congeners that leached out was up to 4.5 times higher than for the heavier PBDEs. To study the scenario in which a child would mouth on a toy flame retarded with BDE 209 alone, a plastic item containing 7% BDE 209 (w/w) was also tested. The BDE 209 amounts leached out in only 15 min were higher than the amounts leached from the CRM after the 16 h incubation. For the Belgian population, the exposure scenario from mouthing on toys containing PBDEs in amounts similar to the REACH threshold was found to be lower than the exposure from mother's milk, but higher than the exposure through diet or even dust. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Sex difference in polybrominated diphenyl ether concentrations of walleyes

    Science.gov (United States)

    Madenjian, Charles P.; Trombka, Autumn W.; Rediske, Richard R.; Jude, David J.; O'Keefe, James P.

    2012-01-01

    Polybrominated diphenyl ether (PBDE) concentrations were determined for mature male and mature female walleyes (Sander vitreus) sampled from the Saginaw Bay population during 2007. PBDE concentrations in prey fish caught in the Saginaw River, the primary tributary to Saginaw Bay, and in Saginaw Bay during 2005 and 2007 also were determined. Mature male and mature female walleyes averaged 70.3 ng/g and 24.8 ng/g, respectively, in ΣPBDE, which was equal to the sum of concentrations of six PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, and BDE-154). This sex difference was likely due to males spending more time in the Saginaw River system than females. Prey fish captured in the Saginaw River were roughly ten times higher in ΣPBDE than those caught in Saginaw Bay. BDE-47 was the predominant congener in both walleyes and prey fish, and this congener contributed about 50%, on average, to ΣPBDE. Congener profiles differed significantly between the two sexes of walleyes. In contrast, congener profiles of the prey fish did not differ significantly between the river-caught fish and the bay-caught fish. One plausible explanation for these congener profile results was that net trophic transfer efficiencies of PBDEs to walleyes from their prey were similar for all congeners except BDE-28, and that diet composition differed between the two sexes of walleyes.

  2. Maternal-infant transfer of polybrominated diphenyl ethers

    Energy Technology Data Exchange (ETDEWEB)

    Hirai, T.; Fujimine, Y.; Watanabe, S. [Otsuka Pharmaceutical Co., Ltd., Tokushima (Japan); Nakamura, Y. [SRL Nishinihon, Fukuoka (Japan); Shimomura, H. [Shimomura OBGY Clinic, Fukuoka (Japan); Nagayama, J. [Kyushu Univ., Fukuoka (Japan)

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants (BFRs) in plastics of automobiles, textile industry, television, personal computer, electronic appliances etc. The amount of production world-wide has reached 40,000 tons in 1992. In 1992 world-wide production of PBDEs reached 40,000 tons raising serious concern over the dangers of environmental pollution by BFRs. The toxicity of PBDEs was reported to be an antagonist of thyroid-hormone (T4) and inhibition to aryl hydrocarbon (Ah) receptor. Since PBDEs are structurally similar to PCBs and therefore they work as an antagonist. Polychlorinated biphenyl (PCBs) demonstrate biological stability and high lipophilicity. As a result, PCBs used in the past and released into the environment, have been transmitted through the food chain and accumlated in the human body over time. In Japan, approximately 58,000 tons of PCBs were produced with the grade name of Kanechlor in between 1954 and 1971. In this study, all PCB congeners and 25 PBDE congeners (17, 25, 28, 30, 32, 33, 35, 37, 47, 49, 66, 71, 75, 77, 85, 99, 100, 116, 119, 126, 138, 153, 154, 155, 166) were analyzed by the method that combines high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). The purpose of this study was to investigate whether congener-specific PCBs and PBDEs were transferred from pregnant women to their infants.

  3. Recovering uranium from phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Bergeret, M [Compagnie de Produits Chimiques et Electrometallurgiques Pechiney-Ugine Kuhlmann, 75 - Paris (France)

    1981-06-01

    Processes for the recovery of the uranium contained in phosphates have today become competitive with traditional methods of working uranium sources. These new possibilities will make it possible to meet more rapidly any increases in the demand for uranium: it takes ten years to start working a new uranium deposit, but only two years to build a recovery plant.

  4. Acute and Developmental Behavioral Effects of Flame ...

    Science.gov (United States)

    As polybrominated diphenyl ethers are phased out, numerous compounds are emerging as potential replacement flame retardants for use in consumer and electronic products. Little is known, however, about the neurobehavioral toxicity of these replacements. This study evaluated the neurobehavioral effects of acute or developmental exposure to t-butylphenyl diphenyl phosphate (BPDP), 2-ethylhexyl diphenyl phosphate (EHDP), isodecyl diphenyl phosphate (IDDP), isopropylated phenyl phosphate (IPP), tricresyl phosphate (TMPP; also abbreviated TCP), triphenyl phosphate (TPHP; also abbreviated TPP), tetrabromobisphenol A (TBBPA), tris (2-chloroethyl) phosphate (TCEP), tris (1,3-dichloroisopropyl) phosphate (TDCIPP; also abbreviated TDCPP), tri-o-cresyl phosphate (TOCP), and 2,2-,4,4’-tetrabromodiphenyl ether (BDE-47) in zebrafish (Danio rerio) larvae. Larvae (n≈24 per dose per compound) were exposed to test compounds (0.4 - 120 µM) at sub-teratogenic concentrations either developmentally or acutely, and locomotor activity was assessed at 6 days post fertilization. When given developmentally, all chemicals except BPDP, IDDP and TBBPA produced behavioral effects. When given acutely, all chemicals produced behavioral effects, with TPHP, TBBPA, EHDP, IPP, and BPDP eliciting the most effects at the most concentrations. The results indicate that these replacement flame retardants may have developmental or pharmacological effects on the vertebrate nervous system. This study

  5. Polybrominated diphenyl ethers: occurrence, dietary exposure, and toxicology.

    Science.gov (United States)

    Darnerud, P O; Eriksen, G S; Jóhannesson, T; Larsen, P B; Viluksela, M

    2001-03-01

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in plastics (concentration, 5--30%) and in textile coatings. Commercial products consist predominantly of penta-, octa-, and decabromodiphenyl ether mixtures, and global PBDE production is about 40,000 tons per year. PBDEs are bioaccumulated and biomagnified in the environment, and comparatively high levels are often found in aquatic biotopes from different parts of the world. During the mid-1970--1980s there was a substantial increase in the PBDE levels with time in both sediments and aquatic biota, whereas the latest Swedish data (pike and guillemot egg) may indicate that levels are at steady state or are decreasing. However, exponentially increasing PBDE levels have been observed in mother's milk during 1972--1997. Based on levels in food from 1999, the dietary intake of PBDE in Sweden has been estimated to be 0.05 microg per day. Characteristic end points of animal toxicity are hepatotoxicity, embryotoxicity, and thyroid effects as well as maternal toxicity during gestation. Recently, behavioral effects have been observed in mice on administration of PBDEs during a critical period after birth. Based on the critical effects reported in available studies, we consider the lowest-observed-adverse-effect level (LOAEL) value of the PBDE group to be 1 mg/kg/day (primarily based on effects of pentaBDEs). In conclusion, with the scientific knowledge of today and based on Nordic intake data, the possible consumer health risk from PBDEs appears limited, as a factor of over 10(6) separates the estimated present mean dietary intake from the suggested LOAEL value. However, the presence of many and important data gaps, including those in carcinogenicity, reproduction, and developmental toxicity, as well as additional routes of exposure, make this conclusion only preliminary. Moreover, the time trend of PBDEs in human breast milk is alarming for the future.

  6. Effect of polybrominated diphenyl ether congeners on placental cytokine production.

    Science.gov (United States)

    Arita, Yuko; Yeh, Corinne; Thoma, Theodosia; Getahun, Darios; Menon, Ramkumar; Peltier, Morgan R

    2018-02-01

    Polybrominated diphenyl ethers (PBDEs) are pollutants that may increase the risk of preterm birth. In previous studies, we found that a mixture of PBDEs altered the expression of biomarkers for preterm birth by the placenta. However, there are 209 different PBDE congeners with different tissue distributions. How these different congeners may alter the production of immunomodulators by the placenta that help to maintain the survival of the fetal allograft is unclear. Therefore, we compared the effects 5 common congeners on basal and bacteria-stimulated cytokine production by the placenta. Placental explant cultures were incubated with 20 μM of PBDE congeners 47, 99, 100, 153, 209 or vehicle in the presence and absence of Escherichia coli for 20 h. Conditioned medium was harvested and concentrations of IL-1β, TNF-α, IL-6, sgp130, HO-1, IL-10, BDNF, and 8-IsoP quantified. For unstimulated cultures, all congeners, except for PBDE-47, reduced the production of IL-1β and IL-6 production was enhanced by PBDE-153. BDNF concentrations tended to be reduced by most PBDE congeners and IL-10 production was enhanced by PBDE-99, -153, and -209. 8-IsoP production was enhanced by PBDE-153, but not the other congeners. For bacteria-stimulated cultures, PBDE-47 increased IL-1β production and PBDE-47, -153, and -209 tended to reduce TNF-α production. IL-6 production was enhanced by all PBDEs except 153. IL-10 production was enhanced by all congeners except for PBDE-47. All congeners significantly enhanced BDNF and 8-IsoP. These results suggest that PBDEs can alter the expression of placental biomarkers in a congener and infection-dependent manner. Copyright © 2018 Elsevier B.V. All rights reserved.

  7. Depositional characteristics of atmospheric polybrominated diphenyl ethers on tree barks

    Directory of Open Access Journals (Sweden)

    Man Young Chun

    2014-07-01

    Full Text Available Objectives This study was conducted to determine the depositional characteristics of several tree barks, including Ginkgo (Ginkgo biloba, Pine (Pinus densiflora, Platanus (Platanus, and Metasequoia (Metasequoia glyptostroboides. These were used as passive air sampler (PAS of atmospheric polybrominated diphenyl ethers (PBDEs. Methods Tree barks were sampled from the same site. PBDEs were analyzed by highresolution gas chromatography/high-resolution mass spectrometer, and the lipid content was measured using the gravimetric method by n-hexane extraction. Results Gingko contained the highest lipid content (7.82 mg/g dry, whereas pine (4.85 mg/g dry, Platanus (3.61 mg/g dry, and Metasequoia (0.97 mg/g dry had relatively lower content. The highest total PBDEs concentration was observed in Metasequoia (83,159.0 pg/g dry, followed by Ginkgo (53,538.4 pg/g dry, Pine (20,266.4 pg/g dry, and Platanus (12,572.0 pg/g dry. There were poor correlations between lipid content and total PBDE concentrations in tree barks (R2=0.1011, p =0.682. Among the PBDE congeners, BDE 206, 207 and 209 were highly brominated PBDEs that are sorbed to particulates in ambient air, which accounted for 90.5% (84.3-95.6% of the concentration and were therefore identified as the main PBDE congener. The concentrations of particulate PBDEs deposited on tree barks were dependent on morphological characteristics such as surface area or roughness of barks. Conclusions Therefore, when using the tree barks as the PAS of the atmospheric PBDEs, samples belonging to same tree species should be collected to reduce errors and to obtain reliable data.

  8. Depositional characteristics of atmospheric polybrominated diphenyl ethers on tree barks.

    Science.gov (United States)

    Chun, Man Young

    2014-07-17

    This study was conducted to determine the depositional characteristics of several tree barks, including Ginkgo (Ginkgo biloba), Pine (Pinus densiflora), Platanus (Platanus), and Metasequoia (Metasequoia glyptostroboides). These were used as passive air sampler (PAS) of atmospheric polybrominated diphenyl ethers (PBDEs). Tree barks were sampled from the same site. PBDEs were analyzed by highresolution gas chromatography/high-resolution mass spectrometer, and the lipid content was measured using the gravimetric method by n-hexane extraction. Gingko contained the highest lipid content (7.82 mg/g dry), whereas pine (4.85 mg/g dry), Platanus (3.61 mg/g dry), and Metasequoia (0.97 mg/g dry) had relatively lower content. The highest total PBDEs concentration was observed in Metasequoia (83,159.0 pg/g dry), followed by Ginkgo (53,538.4 pg/g dry), Pine (20,266.4 pg/g dry), and Platanus (12,572.0 pg/g dry). There were poor correlations between lipid content and total PBDE concentrations in tree barks (R(2)=0.1011, p =0.682). Among the PBDE congeners, BDE 206, 207 and 209 were highly brominated PBDEs that are sorbed to particulates in ambient air, which accounted for 90.5% (84.3-95.6%) of the concentration and were therefore identified as the main PBDE congener. The concentrations of particulate PBDEs deposited on tree barks were dependent on morphological characteristics such as surface area or roughness of barks. Therefore, when using the tree barks as the PAS of the atmospheric PBDEs, samples belonging to same tree species should be collected to reduce errors and to obtain reliable data.

  9. Synthesis and physicochemical properties of polyhydroxylated diphenyl ethers

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Fu; Zhang, Xuesheng; Qu, Ruijuan; Shi, Jiaqi; Wang, Zunyao, E-mail: wangzun315cn@163.com

    2013-09-20

    Highlights: • The experimental pK{sub a1} values of five synthesized PHODEs were determined. • The hydrogen bonds existed in PHODEs were investigated. • There exist close relationships between the thermodynamic properties and N{sub PHOS}. • The relative stability order of PHODE congeners was theoretically proposed. - Abstract: Five polyhydroxylated diphenyl ethers (PHODEs) were synthesized. The first ionization constants (pK{sub a1}) of the synthesized compounds and seven phenolic compounds were determined using potentiometric titration experiments, together with the software ACD/Labs pK{sub a} DB program (version 6.0). The compared results showed that the software could be used to predict the pK{sub a1} of all 209 PHODEs. The thermodynamic properties of 209 PHODEs were calculated using density functional theory (DFT) at the B3LYP/6-311G** level with Gaussian 09 program. The standard enthalpy of formation (Δ{sub f}H{sup θ}) and the standard Gibbs energy of formation (Δ{sub f}G{sup θ}) were obtained. Two types of hydrogen bond were found to exist in the PHODEs’ molecules. The intramolecular hydrogen bond energies were discussed. The relative stability of PHODEs isomers was proposed theoretically with the relative standard Gibbs energy of formation (Δ{sub f}G{sub R}{sup θ}). The relationships of S{sup θ}, Δ{sub f}H{sup θ} and Δ{sub f}G{sup θ} to the number and position of the hydroxyl substitution (N{sub PHOS}) were studied.

  10. Renal phosphate handling: Physiology

    Directory of Open Access Journals (Sweden)

    Narayan Prasad

    2013-01-01

    Full Text Available Phosphorus is a common anion. It plays an important role in energy generation. Renal phosphate handling is regulated by three organs parathyroid, kidney and bone through feedback loops. These counter regulatory loops also regulate intestinal absorption and thus maintain serum phosphorus concentration in physiologic range. The parathyroid hormone, vitamin D, Fibrogenic growth factor 23 (FGF23 and klotho coreceptor are the key regulators of phosphorus balance in body.

  11. Meta-Analysis of the Associations of p-Cresyl Sulfate (PCS) and Indoxyl Sulfate (IS) with Cardiovascular Events and All-Cause Mortality in Patients with Chronic Renal Failure.

    Science.gov (United States)

    Lin, Cheng-Jui; Wu, Vincent; Wu, Pei-Chen; Wu, Chih-Jen

    2015-01-01

    Indoxyl sulfate (IS) and p-cresyl sulfate (PCS) are protein-bound uremic toxins that increase in the sera of patients with chronic kidney disease (CKD), and are not effectively removed by dialysis. The purpose of this meta-analysis was to investigate the relationships of PCS and IS with cardiovascular events and all-cause mortality in patients with CKD stage 3 and above. Medline, Cochrane, and EMBASE databases were searched until January 1, 2014 with combinations of the following keywords: chronic renal failure, end-stage kidney disease, uremic toxin, uremic retention, indoxyl sulfate, p-cresyl sulfate. Inclusion criteria were: 1) Patients with stage 1 to 5 CKD; 2) Prospective study; 3) Randomized controlled trial; 4) English language publication. The associations between serum levels of PCS and IS and the risks of all-cause mortality and cardiovascular events were the primary outcome measures. Of 155 articles initially identified, 10 prospective and one cross-sectional study with a total 1,572 patients were included. Free PCS was significantly associated with all-cause mortality among patients with chronic renal failure (pooled OR = 1.16, 95% CI = 1.03 to 1.30, P = 0.013). An elevated free IS level was also significantly associated with increased risk of all-cause mortality (pooled OR = 1.10, 95% CI = 1.03 to 1.17, P = 0.003). An elevated free PCS level was significantly associated with an increased risk of cardiovascular events among patients with chronic renal failure (pooled OR = 1.28, 95% CI = 1.10 to 1.50, P = 0.002), while free IS was not significantly associated with risk of cardiovascular events (pooled OR = 1.05, 95% CI = 0.98 to 1.13, P = 0.196). Elevated levels of PCS and IS are associated with increased mortality in patients with CKD, while PCS, but not IS, is associated with an increased risk of cardiovascular events.

  12. Oxidative transformation of polybrominated diphenyl ether congeners (PBDEs) and of hydroxylated PBDEs (OH-PBDEs).

    Science.gov (United States)

    Moreira Bastos, Patricia; Eriksson, Johan; Vidarson, Jenny; Bergman, Ake

    2008-10-01

    The historical and widespread use of polybrominated diphenyl ethers (PBDEs) as flame retardants in consumer products worldwide has caused PBDEs to now be regarded as pervasive environmental contaminants. Most recently, hydroxylated PBDEs (OH-PBDEs) and methoxylated PBDEs (MeO-PBDEs) have emerged as environmentally relevant due to reports of their natural production and metabolism. An important parameter for assessing the environmental impact of a chemical substance is persistence. By formulating the concept that persistence is the result of the substance's physicochemical properties and chemical reactivity, Green and Bergman have proposed a new methodology to determine the inherent persistence of a chemical. If persistence could be predicted by straightforward methods, substances with this quality could be screened out before large-scale production/manufacturing begins. To provide data to implement this concept, we have developed new methodologies to study chemical transformations through photolysis; hydrolysis, substitution, and elimination; and via oxidation. This study has focused on adapting an oxidative reaction method to be applicable to non-water soluble organic pollutants. PBDEs and one MeO-PBDE were dissolved in tetrahydrofuran/methanol and then diluted in alkaline water. The OH-PBDEs were dissolved in alkaline water prior to reaction. The oxidation degradation reaction was performed at 50 degrees C using potassium permanganate as described elsewhere. The pH was maintained at 7.6 with disodium hydrogen phosphate and barium hydrogen phosphate, the latter also serving as a trapping agent for manganate ions. The oxidation reactions were monitored by high-performance liquid chromatography and reaction rates were calculated. The OH-PBDEs have very fast oxidative transformation rates compared to the PBDEs. The reaction rates seem to be primarily dependent on substitution pattern of the pi-electron-donating bromine substituents and of bromine content. There are

  13. Polybrominated diphenyl ethers: human tissue levels and toxicology.

    Science.gov (United States)

    Gill, Udai; Chu, Ih; Ryan, John J; Feeley, Mark

    2004-01-01

    PBDEs are being released to the environment in wastes from their production facilities, degradation, or leaching and volatilization from products that contain PBDEs during the product's useful life. Brominated diphenyl ether congeners BDE-47, -99, and -153 are ubiquitous in the environment and are regarded as the most dominant congeners present in wildlife and humans. The tetra- to hexa-BDE are most likely the congeners to which humans are exposed through food consumption. Knowledge of PBDE uptake, metabolism, elimination, and enzyme induction is restricted largely to rodents (rats and mice) in vitro and in vivo. Feeding studies have shown that excretion of higher brominated BDEs is much greater than lower brominated BDEs. Penta-BDE is more toxic than octa- and deca-BDE following oral administration (oral LD50 in rats, 0.5-5 g/kg). In rodents, repeated exposure to PBDEs results in thyroid hormone disruption, developmental neurotoxicity, some changes of fetal development, and hepatotoxic effects. The observed chronic NOELs depend upon the technical mixture type (i.e., deca-, octa-, or penta- and their congener composition), animal species, and study protocol. Values range from 0.6 to 100 mg/kg in rats and from I to 100 mg/kg in mice. PBDEs are neither mutagenic nor genotoxic. Immunotoxicity in mice is observed following exposure to BDE-47 at 18 mg/kg/d, where splenocyte number decreased. Mice exposed neonatally to a single oral dose of BDE-47(10.5 mg/kg) or BDE-99 (12 mg/kg) on Pnd10 (period of rapid brain growth and development) show permanent impairment of spontaneous motor behavior when reaching adulthood. BDE-99 also induced adverse effects on learning and memory functions of mice. The estimated daily intake based on food consumption for PBDEs ranges from 44 to 51 ng/d, with fish contributing almost one-half. The BDE-99 body burden from a human milk survey can be estimated at 0.64 microg/kg, well below the experimental body burden of 0.4 mg/kg BDE-99 associated

  14. Polybrominated diphenyl ethers (PBDEs) and thyroid hormones in cord blood

    International Nuclear Information System (INIS)

    Ding, Guodong; Yu, Jing; Chen, Limei; Wang, Caifeng; Zhou, Yijun; Hu, Yi; Shi, Rong; Zhang, Yan; Cui, Chang; Gao, Yu; Tian, Ying; Liu, Fang

    2017-01-01

    Human exposure to polybrominated diphenyl ethers (PBDEs) has been increasing over the last three decades in China and around the world. Animal studies suggest that PBDEs could reduce blood levels of thyroid hormones, but it is unclear whether PBDEs disrupt thyroid function in humans. We used data from a prospective birth cohort of 123 pregnant women who were enrolled between September 2010 and March 2011 in Shandong, China. We measured the concentrations of eight PBDE congeners (n = 106) and five thyroid hormones (n = 107) in cord serum samples. We examined the relationship between prenatal exposure to PBDEs and thyroid function (n = 90). Median concentrations of BDEs 47, 99, 100, and 153 (detection frequencies > 75%) were 3.96, 8.27, 3.31, and 1.89 ng/g lipid, respectively. A 10-fold increase in BDE-99 and Σ 4 PBDEs (the sum of BDEs 47, 99, 100, and 153) concentrations was associated with a 0.41 μg/dL (95% confidence interval [CI]: 0.10 to 0.72) and 0.37 μg/dL (95% CI: 0.06 to 0.68) increase in total thyroxine levels (TT 4 ), respectively. No associations were found between other individual congeners and any of the five thyroid hormones. Our study suggests that prenatal exposure to PBDEs may be associated with higher TT 4 in cord blood. Given the inconsistent findings across existing studies, our results need to be confirmed in additional studies. - Highlights: • Human exposure to PBDEs has been increased over recent decades in China. • PBDEs reduce thyroid hormones in animal studies, but it is unclear in humans. • We examined the relation of PBDE levels with thyroid hormones in cord blood. • Prenatal exposure to PBDEs is associated with higher total thyroxine levels. • The findings may have implications for fetal development. - Exposure to PBDEs is associated with higher total thyroxine levels in cord blood, and the findings may have implications for fetal development.

  15. Integrated assessment of the phosphate industry

    International Nuclear Information System (INIS)

    Ryan, M.T.; Cotter, S.J.

    1980-05-01

    The phosphate industry in the United States includes three major activities, namely, mining and milling of phosphate rock, phosphate product manufacture, and phosphate product use. Phosphatic materials contain uranium, thorium, and their decay products in greater than background amounts. This assessment of the radiological impacts associated with the redistribution of radioactive components of phosphate materials may provide insight into the effects of uranium extraction from phosphate materials for use in the nuclear fuel cycle

  16. Better prospects for phosphate production

    Energy Technology Data Exchange (ETDEWEB)

    1980-06-01

    The extraction of uranium as a by product of phosphate production is discussed. Techniques being commercially developed are described. The trend towards the wet process, in which sulphuric acid is used to dissolve the phosphate, producing phosphoric acid, is also the preferred method for uranium recovery. Recovery from a wet process phosphoric acid stream, integrated with phosphate fertilizer manufacture, is becoming increasingly commercially viable for the production of yellow-cake.

  17. on association of trialkyl phosphates

    International Nuclear Information System (INIS)

    Petkovic, D.M.; Maksimovic, Z.B.

    1976-01-01

    The association constants of tri-n-butyl (TBP), tri-n-propyl (TPP) and triethyl phosphate (TEP) with chloroform, carbon tetrachloride and benzene were determined by dielectric constant, proton magnetic resonance and vapor pressure measurements. Correlation of the trialkyl phosphate-chloroform association constants, using the Hammett equation, showed their increase with the number of carbon atoms in the aliphatic radicals. The change of trialkyl phosphate reactivity with temperature was used to determine the thermodynamic quantities. (author)

  18. Triclosan and Hydroxylated Polybrominated Diphenyl Ethers in Lake and Esturaine Sediments

    Science.gov (United States)

    Arnold, W. A.; Kerrigan, J. F.; McNeill, K.; Erickson, P. R.; Grandbois, M.

    2014-12-01

    Halogenated diphenyl ethers are a class of emerging contaminants that includes the antibacterial compound triclosan and the flame retardant polybrominated diphenyl ethers (PBDEs). Both triclosan and hydroxylated polybrominated diphenyl ethers (OH-BDEs) are known to form dioxins when exposed to sunlight in aqueous solution. Thus, it is important to understand the sources and presence of these compounds in the environment, especially because OH-BDEs are breakdown products of PBDEs and also naturally produced compounds. In this work, the levels of OH-BDEs were determined in lake sediments from Minnesota and esturaine sediments from San Francisco Bay. Both surface sediments over a broad spatial area and sediment cores were collected and analyzed. Triclosan was used as a marker of wastewater as a source of the targeted emerging contaminants. The relationship between triclosan and OH-BDE levels provides insight into the importance of natural and anthropogenic influences on the levels of OH-BDEs.

  19. Induced production of halogenated diphenyl ethers from the marine-derived fungus Penicillium chrysogenum.

    Science.gov (United States)

    Yang, Guohua; Yun, Keumja; Nenkep, Viviane N; Choi, Hong Dae; Kang, Jung Sook; Son, Byeng Wha

    2010-11-01

    Manipulation of the fermentation of the marine-derived fungus Penicillium chrysogenum by addition of CaBr(2) resulted in induced production of bromodiphenyl ether analogs. Two new free-radical-scavenging polybrominated diphenyl ethers, 1 and 2, and three known diphenyl ethers, 3,3'-dihydroxy-5,5'-dimethyldiphenyl ether (3), and an inseparable mixture of violacerol-I (4) and violacerol-II (5) were isolated. The structures of the two new polybromodiphenyl ethers 1 and 2 were assigned by combined spectroscopic-data analysis, including deuterium-induced isotope effect. Compounds 1-3, and a mixture of 4 and 5 exhibited radical-scavenging activities against 1,1-diphenyl-2-picrylhydrazyl with IC(50) values of 18, 15, 42, and 6 μM, respectively. With the exception of 3, the compounds were, therefore, more active than the positive control, ascorbic acid (IC(50) 20 μM).

  20. Phosphate Recovery From Sewage Sludge Containing Iron Phosphate

    NARCIS (Netherlands)

    Wilfert, P.K.

    2018-01-01

    The scope of this thesis was to lay the basis for a phosphate recovery technology that can be applied on sewage sludge containing iron phosphate. Such a technology should come with minimal changes to the existing sludge treatment configuration while keeping the use of chemicals or energy as small as

  1. Rigid-rod polyamides and polyimides derived from 4,3 ''-diamino-2 ',6 '-diphenyl- or di(4-biphenylyl)-p-terphenyl and 4-amino-4 ''-carboxy-2 ',6 '-diphenyl-p-terphenyl

    NARCIS (Netherlands)

    Spiliopoulos, IK; Mikroyannidis, JA; Tsivgoulis, GM

    1998-01-01

    4,3 "-Diamino-2',6'-diphenyl- or di(4-biphenylyl)p-terphenyl (3a or 3b) and 4-amino-4 "-carboxy-2',6'-diphenyl-p-terphenyl (6) were synthesized through pyrylium salts and used for the preparation of rigid-rod polyamides and polyimides. The polymers were characterized by inherent viscosity, elemental

  2. 21 CFR 137.175 - Phosphated flour.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Phosphated flour. 137.175 Section 137.175 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Related Products § 137.175 Phosphated flour. Phosphated flour, phosphated white flour, and phosphated...

  3. Evaluation of diphenyl and dowtherm-A's thermal cross sections and their application to reactor calculation

    International Nuclear Information System (INIS)

    Florido, P.C.; Gillette, V.H.; Granada, J.R.; Patino, N.E.

    1990-01-01

    This work applies a scattering synthetic approximation to represent diphenyl and dowtherm-A dispersion laws on typical ranges of interest regarding temperature. The present formalism is based on a previous model of benzene molecule formerly validated. The results obtained from diphenyl agree with laboratory measurements, but those regarding dowtherm-A present some variations with respect to the available information. The result of the application of this model to the measurements made in Wrenlingen (Switzerland) to measure the vacuum coefficient of the cells charasteristic of high conversion reactors, are also presented, experimentally simulating said vacuum using dowtherm-A instead of H 2 O. (Author) [es

  4. Toxicokinetics of 14C-saligenin cyclic-o-tolyl phosphate (SCOTP) in male F-344 rats

    International Nuclear Information System (INIS)

    Chapin, R.E.; Burka, L.T.

    1990-01-01

    SCOTP has been proposed as the active metabolite of tri-o-cresyl phosphate (TOCP), a neurotoxic organophosphate. TOCP is also toxic to the testis and SCOTP mimics some of this toxicity. SCOTP is reactive and may not be sufficiently stable to be made elsewhere and transported by blood to the testis. SCOTP's stability in vivo and its uptake by the testes has now been made measured. Male F-344 rats treated iv with 1 mg of 14C-SCOTP/kg were killed at intervals ranging from 5 to 60 min. Blood and selected tissues were rapidly removed at sacrifice, extracted with acetonitrile and analyzed by HPLC. Total radioactivity in these tissues was also determined. The half-life of SCOTP in blood was 8.0 ± 1.1 min. Testes, along with brain and muscle, had lower concentrations of 14C-SCOTP derived radioactivity than blood. Liver and kidney had higher concentrations of radioactivity than blood. HPLC analysis of liver, kidney, testes and blood extracts showed that 2.8, 48, 11 and 18%, respectively, of the radioactivity present at 5 min was SCOTP. The amount of SCOTP declined rapidly, and at 30 min SCOTP could be detected only in kidney. From these results it appears that SCOTP, although reactive, has sufficient stability to be transported from organ to organ. There is no evidence of active uptake of SCOTP from blood by the testes

  5. Phosphate glasses, containing nitrogen

    International Nuclear Information System (INIS)

    Lisitsyna, E.A.; Khalilev, V.D.; Koryavin, A.A.; Goncharova, L.N.

    1987-01-01

    Possibilities of nitrogen-containing glass synthesis by the introduction into the charge of ammonium salts, as well as aluminium nitride, are studied. Zinc alumoyttrium phosphate glass (mol. %) Zn(PO 3 ) 2 - 4O, Al(PO 3 ) 3 - 3O, Y(PO 3 ) 3 -3O is suggested as a matrix. It is shown that the effect of amide and imide groups on the properties of the glass is less noticeable than the effect of nitride groups. Direct introduction of nitride constituent was realized using AlN, but aluminium introduction was taken into account so that the oxide was subtracted. The attempt to introduce more than 2.5 mass % of nitrogen into initial matrix by aluminium nitride has failed due to repeated restoration of glass with amorphous phosphorus isolation

  6. Study of reactivity of p-cymene ruthenium(II) dimer towards diphenyl ...

    Indian Academy of Sciences (India)

    Unknown

    The reaction of [{(η6-p-cymene)Ru(µ-Cl)}2Cl2] with functionalized phosphine viz, diphenyl-. 2-pyridylphosphine ... ing from the displacement of the p-cymene ligand. ... The structures of complexes 1 and 2 have been confirmed by single crystal.

  7. A National Probabilistic Study of Polybrominated Diphenyl Ethers in Fish from US Lakes and Reservoirs

    Science.gov (United States)

    National estimates were developed for polybrominated diphenyl ethers (PBDEs) in fish from lakes and reservoirs of the conterminous United States (excluding the Laurentian Great Lakes and Great Salt Lake) using an unequal probability design. Predator (fillet) and bottom-dweller (w...

  8. In vitro estrogenicity of polybrominated diphenyl ethers, hydroxylated PBDEs, and polybrominated bisphenol A compounds

    NARCIS (Netherlands)

    Meerts, I.A.T.M.; Letcher, R.J.; Hoving, S.; Marsh, G.; Bergman, A.; Lemmen, J.G.; Burg, van der B.; Brouwer, A.

    2001-01-01

    Polybrominated diphenyl ethers (PBDEs) are used in large quantities as additive flame retardants in plastics and textile materials. PBDEs are persistent compounds and have been detected in wildlife and in human adipose tissue and plasma samples. In this study, we investigated the (anti)estrogenic

  9. Photosynthesis involvement in the mechanism of action of diphenyl ether herbicides.

    Science.gov (United States)

    Ensminger, M P; Hess, F D

    1985-05-01

    Photosynthesis is not required for the toxicity of diphenyl ether herbicides, nor are chloroplast thylakoids the primary site of diphenyl ether herbicide activity. Isolated spinach (Spinacia oleracea L.) chloroplast fragments produced malonyl dialdehyde, indicating lipid peroxidation, when paraquat (1,1'-dimethyl-4,4'-bipyridinium ion) or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were added to the medium, but no malonyl dialdehyde was produced when chloroplast fragments were treated with the methyl ester of acifluorfen (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid), oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene], or MC15608 (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate). In most cases the toxicity of acifluorfen-methyl, oxyfluorfen, or MC15608 to the unicellular green alga Chlamydomonas eugametos (Moewus) did not decrease after simultaneous treatment with diuron. However, diuron significantly reduced cell death after paraquat treatment at all but the highest paraquat concentration tested (0.1 millimolar). These data indicate electron transport of photosynthesis is not serving the same function for diphenyl ether herbicides as for paraquat. Additional evidence for differential action of paraquat was obtained from the superoxide scavenger copper penicillamine (copper complex of 2-amino-3-mercapto-3-methylbutanoic acid). Copper penicillamine eliminated paraquat toxicity in cucumber (Cucumis sativus L.) cotyledons but did not reduce diphenyl ether herbicide toxicity.

  10. Photosynthesis Involvement in the Mechanism of Action of Diphenyl Ether Herbicides 1

    Science.gov (United States)

    Ensminger, Michael P.; Hess, F. Dan

    1985-01-01

    Photosynthesis is not required for the toxicity of diphenyl ether herbicides, nor are chloroplast thylakoids the primary site of diphenyl ether herbicide activity. Isolated spinach (Spinacia oleracea L.) chloroplast fragments produced malonyl dialdehyde, indicating lipid peroxidation, when paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) or diuron [3-(3,4-dichlorophenyl)-1,1-dimethylurea] were added to the medium, but no malonyl dialdehyde was produced when chloroplast fragments were treated with the methyl ester of acifluorfen (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-nitrobenzoic acid), oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene], or MC15608 (methyl 5-[2-chloro-4-(trifluoromethyl)phenoxy]-2-chlorobenzoate). In most cases the toxicity of acifluorfen-methyl, oxyfluorfen, or MC15608 to the unicellular green alga Chlamydomonas eugametos (Moewus) did not decrease after simultaneous treatment with diuron. However, diuron significantly reduced cell death after paraquat treatment at all but the highest paraquat concentration tested (0.1 millimolar). These data indicate electron transport of photosynthesis is not serving the same function for diphenyl ether herbicides as for paraquat. Additional evidence for differential action of paraquat was obtained from the superoxide scavenger copper penicillamine (copper complex of 2-amino-3-mercapto-3-methylbutanoic acid). Copper penicillamine eliminated paraquat toxicity in cucumber (Cucumis sativus L.) cotyledons but did not reduce diphenyl ether herbicide toxicity. PMID:16664206

  11. Buffalo embryos produced by handmade cloning from oocytes selected using brilliant cresyl blue staining have better developmental competence and quality and are closer to embryos produced by in vitro fertilization in terms of their epigenetic status and gene expression pattern.

    Science.gov (United States)

    Mohapatra, Sushil K; Sandhu, Anjit; Neerukattu, Venkata S; Singh, Karn P; Selokar, Naresh L; Singla, Suresh K; Chauhan, Manmohan S; Manik, Radhey S; Palta, Prabhat

    2015-04-01

    We compared handmade cloned (HMC) buffalo blastocysts produced from oocytes stained with Brilliant Cresyl Blue (BCB) and classified into those with blue (BCB+) or colorless cytoplasm (BCB-). The blastocyst rate was higher (p<0.001) for BCB+ than for BCB- oocytes (43.41 ± 2.54 vs. 22.74 ± 1.76%). BCB+ blastocysts had inner cell mass (ICM) cell number, ICM-to-trophectoderm ratio, global level of H3K18ac, apoptotic index, and expression level of BCL-XL, but not that of CASPASE-3, similar to that of blastocysts produced through in vitro fertilization (IVF), which was higher (p<0.05) than that of BCB- blastocysts. The global level of H3K9me2, which was similar in BCB+ and BCB- blastocysts, was higher (p<0.01) than that in IVF blastocysts. The expression level of OCT4 and SOX2 was higher (p<0.05) and that of GATA2 was lower (p<0.05) in BCB+ than that in BCB- blastocysts, whereas that of DNMT1, DNMT3a, NANOG, and CDX2 was not significantly different between the two groups. The expression level of DNMT1, OCT4, NANOG, and SOX2 was lower (p<0.05) and that of CDX2 was higher (p<0.05) in BCB+ than in IVF blastocysts. In conclusion, because BCB+ blastocysts have better developmental competence and are closer to IVF blastocysts in terms of quality, epigenetic status, and gene expression than BCB- blastocysts, BCB staining can be used effectively for selection of developmentally competent oocytes for HMC.

  12. Electrochemical Reduction of Zinc Phosphate

    International Nuclear Information System (INIS)

    Kim, Chang Hwan; Lee, Jung Hyun; Shin, Woon Sup

    2010-01-01

    We demonstrated first that the electrochemical reduction of zinc phosphate in neutral phosphate buffer is possible and potentially applicable to bio-compatible rechargeable battery. The actual redox component is Zn(s)/Zn phosphate(s) and the future research about the control of crystal formation for the better cyclability is required. In lead-acid battery, the electrochemical redox reaction of Pb (s) /PbSO 4(s) is used by reducing Pb(II) and oxidizing Pb(0) in sulfate rich solution. Since both reduced form and oxidized form are insoluble, they cannot diffuse to the opposite electrodes and react. It is a very common strategy to make a stable battery electrode that a metal element is reduced and oxidized in solution containing an abundance of anion readily precipitating with the metal ion. For the application of this strategy to construction of rechargeable battery using bio-compatible electrode materials and electrolytes, the use of phosphate ion can be considered as anion readily precipitating with metal ions. If phosphate buffer with neutral pH is used as electrolyte, the better bio-compatibility will be achieved than most of rechargeable battery using strong acid, strong base or organic solvent as electrolyte solution. There are many metal ions readily precipitating with phos-phate ion, and zinc is one of them

  13. Subcellular Characterization of Porcine Oocytes with Different Glucose-6-phosphate Dehydrogenase Activities

    Directory of Open Access Journals (Sweden)

    Bo Fu

    2015-12-01

    Full Text Available The in vitro maturation (IVM efficiency of porcine embryos is still low because of poor oocyte quality. Although brilliant cresyl blue positive (BCB+ oocytes with low glucose-6-phosphate dehydrogenase (G6PDH activity have shown superior quality than BCB negative (− oocytes with high G6PDH activity, the use of a BCB staining test before IVM is still controversial. This study aimed to shed more light on the subcellular characteristics of porcine oocytes after selection using BCB staining. We assessed germinal vesicle chromatin configuration, cortical granule (CG migration, mitochondrial distribution, the levels of acetylated lysine 9 of histone H3 (AcH3K9 and nuclear apoptosis features to investigate the correlation between G6PDH activity and these developmentally related features. A pattern of chromatin surrounding the nucleoli was seen in 53.0% of BCB+ oocytes and 77.6% of BCB+ oocytes showed peripherally distributed CGs. After IVM, 48.7% of BCB+ oocytes had a diffused mitochondrial distribution pattern. However, there were no significant differences in the levels of AcH3K9 in the nuclei of blastocysts derived from BCB+ and BCB− oocytes; at the same time, we observed a similar incidence of apoptosis in the BCB+ and control groups. Although this study indicated that G6PDH activity in porcine oocytes was correlated with several subcellular characteristics such as germinal vesicle chromatin configuration, CG migration and mitochondrial distribution, other features such as AcH3K9 level and nuclear apoptotic features were not associated with G6PDH activity and did not validate the BCB staining test. In using this test for selecting porcine oocytes, subcellular characteristics such as the AcH3K9 level and apoptotic nuclear features should also be considered. Adding histone deacetylase inhibitors or apoptosis inhibitors into the culture medium used might improve the efficiency of IVM of BCB+ oocytes.

  14. Synthesis of 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives

    International Nuclear Information System (INIS)

    Elhadi, S. A.

    2004-09-01

    Quinolin derivatives are a group of compounds known to possess a wide range of biological activities. The chemistry of quinolines together with their corresponding aldehydes were dealt with in chapter one of this study. Special emphasis was given to the chemistry of benzaldehyde. Twenty five 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives together with their corresponding intermediates were prepared in this work. Basically, the synthetic design of these compounds arise from the appropriate disconnections of the target 2-phenyl and 2,3-diphenyl-quinolin-4-carboxylic acids. The retro synthesis analysis of these compounds reveals pyruvic acid, aromatic amine and benzaldehyde or phenyl pyruvic acid, aromatic amine and benzaldehyde as possible logical precursors for 2-phenyl-and 2,3-diphenyl- quinoline-4-carboxylic acids respectively. The purity and identities of the synthesized compounds were elucidated through chromatographic and spectroscopic techniques. The compounds were heavily subjected to spectroscopic analysis (UV, IR, GC/MS, 1 H-and 13 C- NMR). The appropriate disconnections and the mechanisms of the corresponding reactions were given and discussed in chapter three. The spectral data were interpreted and correlated with the target structures. The prepared 2-phenyl- and 2,3-diphenyl-quinoline-4-carboxylic acid derivatives were screened for their antibacterial activity. The compounds were tested against the standard bacterial organisms B. subtilis, S. aureus, E. coli and P. vulgaris. Some of these compounds were devoid of antibacterial activity against S. aureus and P. vulgaris, while others showed moderate activity. All of the tested compounds showed an activity against B. subtilis and E. coli. 2,3-diphenyl -6-sulphanilamide-quinolin-4-carboxylic acid showed the highest activity against the four standard tested organisms.(Author)

  15. Synthesis of 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Elhadi, S A [Department of Chemistry, Faculty of Education, University of Khartoum, Khartoum (Sudan)

    2004-09-01

    Quinolin derivatives are a group of compounds known to possess a wide range of biological activities. The chemistry of quinolines together with their corresponding aldehydes were dealt with in chapter one of this study. Special emphasis was given to the chemistry of benzaldehyde. Twenty five 2-phenyl- and 2,3-diphenyl-quinolin-4-carboxylic acid derivatives together with their corresponding intermediates were prepared in this work. Basically, the synthetic design of these compounds arise from the appropriate disconnections of the target 2-phenyl and 2,3-diphenyl-quinolin-4-carboxylic acids. The retro synthesis analysis of these compounds reveals pyruvic acid, aromatic amine and benzaldehyde or phenyl pyruvic acid, aromatic amine and benzaldehyde as possible logical precursors for 2-phenyl-and 2,3-diphenyl- quinoline-4-carboxylic acids respectively. The purity and identities of the synthesized compounds were elucidated through chromatographic and spectroscopic techniques. The compounds were heavily subjected to spectroscopic analysis (UV, IR, GC/MS, {sup 1}H-and {sup 13}C- NMR). The appropriate disconnections and the mechanisms of the corresponding reactions were given and discussed in chapter three. The spectral data were interpreted and correlated with the target structures. The prepared 2-phenyl- and 2,3-diphenyl-quinoline-4-carboxylic acid derivatives were screened for their antibacterial activity. The compounds were tested against the standard bacterial organisms B. subtilis, S. aureus, E. coli and P. vulgaris. Some of these compounds were devoid of antibacterial activity against S. aureus and P. vulgaris, while others showed moderate activity. All of the tested compounds showed an activity against B. subtilis and E. coli. 2,3-diphenyl -6-sulphanilamide-quinolin-4-carboxylic acid showed the highest activity against the four standard tested organisms.(Author)

  16. Hydrogen permeation resistant phosphate coatings

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1979-01-01

    A method for reducing hydrogen diffusion through metal wherein the metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface thereof. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 0 7 . (author)

  17. Hydrogen permeation resistant phosphate coatings

    International Nuclear Information System (INIS)

    McGuire, J.C.

    1979-01-01

    A method for reducing hydrogen diffusion through metal is described. The metal is coated with a phosphate-radical-containing, phosphate-glass-forming material on at least one surface. The coating is then heated to at least 350 0 C to form a phosphate glass. This method is especially applicable to nuclear reactors to minimize tritium diffusion. The coating is preferably formed with a solution of phosphoric acid which may also contain compounds such as MnSO 4 , SiO 2 and Na 2 Cr 2 O 7 . (author)

  18. Calcium phosphates for biomedical applications

    Directory of Open Access Journals (Sweden)

    Maria Canillas

    2017-05-01

    Full Text Available The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies.

  19. 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...

  20. Preparation of calcium phosphate paste

    International Nuclear Information System (INIS)

    Mohd Reusmaazran Yusof; Norzita Yaacob; Idris Besar; Che Seman Mahmood; Rusnah Mustafa

    2010-01-01

    Calcium phosphate paste were prepared by mixing between calcium sodium potassium phosphate, Ca 2 NaK (PO 4 ) 2 (CSPP) and monocalcium phosphate monohydrate, Ca(H 2 PO 4 ) 2 .H 2 O (MCPM). CSPP were obtained by reaction between calcium hydrogen phosphate (CaHPO 4 ), potassium carbonate (K 2 CO 3 ) and sodium carbonate (Na 2 CO 3 ) in solid state sintering process followed by quenching in air at 1000 degree Celsius. The paste was aging in simulated body fluid (SBF) for 0.5, 1, 3, 6, 12, 24, 48 hrs, 3, 7 and 14 days. The morphological investigation indicated the formation of apatite crystal were first growth after 24 hours. The obvious growth of apatite crystal was shown at 3 days. The obvious growth of apatite crystal was shown in 7 and 14 days indicated the prediction of paste would have rapid reaction with bone after implantation. (author)

  1. Calcium phosphates for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Canillas, M.; Pena, P.; Aza, A.H. de; Rodriguez, M.A.

    2017-07-01

    The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies. (Author)

  2. Phosphate solubilization and multiple plant growth promoting ...

    African Journals Online (AJOL)

    Phosphate solubilizing efficiencies of the strains were analyzed using different insoluble phosphorus sources and the results show that most isolates released a substantial amount of soluble phosphate from tricalcium phosphate, rock phosphate and bone meal. Screening for multiple plant growth promoting attributes ...

  3. Antifungal activities of diphenyl diselenide and ebselen against echinocandin-susceptible and -resistant strains of Candida parapsilosis.

    Science.gov (United States)

    Chassot, Francieli; Pozzebon Venturini, Tarcieli; Baldissera Piasentin, Fernanda; Morais Santurio, Janio; Estivalet Svidzinski, Terezinha Inez; Hartz Alves, Sydney

    2016-10-01

    We evaluated the in vitro antifungal activity of diphenyl diselenide and ebselen against echinocandin-susceptible and -resistant strains of Candida parapsilosis using the broth microdilution method. Diphenyl diselenide (MIC range =1-8 µg/mL) and ebselen (MIC range =0.25-4 µg/mL) showed in vitro activity against echinocandin-susceptible isolates. However, ebselen also showed the highest antifungal activity against echinocandin-resistant strains (MIC range =0.06-4 µg/mL). This study demonstrated that the antifungal potential of diphenyl diselenide and ebselen deserves further investigation using in vivo experimental protocols.

  4. Electrical properties of phosphate glasses

    International Nuclear Information System (INIS)

    Mogus-Milankovic, A; Santic, A; Reis, S T; Day, D E

    2009-01-01

    Investigation of the electrical properties of phosphate glasses where transition metal oxide such as iron oxide is the network former and network modifier is presented. Phosphate glasses containing iron are electronically conducting glasses where the polaronic conduction is due to the electron hopping from low to high iron valence state. The identification of structural defects caused by ion/polaron migration, the analysis of dipolar states and electrical conductivity in iron phosphate glasses containing various alkali and mixed alkali ions was performed on the basis of the impedance spectroscopy (IS). The changes in electrical conductivity from as-quenched phosphate glass to fully crystallized glass (glass-ceramics) by IS are analyzed. A change in the characteristic features of IS follows the changes in glass and crystallized glass network. Using IS, the contribution of glass matrix, crystallized grains and grain boundary to the total electrical conductivity for iron phosphate glasses was analyzed. It was shown that decrease in conductivity is caused by discontinuities in the conduction pathways as a result of the disruption of crystalline network where two or more crystalline phases are formed. Also, phosphate-based glasses offer a unique range of biomaterials, as they form direct chemical bonding with hard/soft tissue. The surface charges of bioactive glasses are recognized to be the most important factors in determining biological responses. The improved bioactivity of the bioactive glasses as a result of the effects of the surface charges generated by electrical polarization is discussed.

  5. AIRBORNE POLYBROMINATED DIPHENYL ETHERS IN A COMPUTER CLASSROOM OF COLLEGE IN TAIWAN

    Directory of Open Access Journals (Sweden)

    F. H. Chang ، C. R. Yang ، C. Y. Tsai ، W. C. Lin

    2009-04-01

    Full Text Available This study characterized the airborne exposure of students to thirty polybrominated diphenyl ether congeners inside and outside a computer classroom in a southern Taiwan college. Arithmetic mean values of total indoor and outdoor polybrominated diphenyl ether concentrations were 125.0 pg/m3 (89.8 to 203.9 pg/m3 and 110.3 pg/m3 (83.5 to 157.0 pg/m3, respectively. Total indoor polybrominated diphenyl ether concentrations were one order of magnitude lower than those detected in homes in Birmingham, United Kingdom and in Ottawa, Canada but were several times higher than those measured in the ambient air in Ottawa, Canada and from the Bohai Sea to the Arctic. The five highest indoor concentrations of polybrominated diphenyl ether congeners were decabromodiphenyl ether (23.0 pg/m3, 4,4’-dibromodiphenyl ether (15.9 pg/m3, 2,2’,3,4,4’,5,5’,6-octabromodiphenyl ether (10.6 pg/m3, 2,4-dibromodiphenyl ether (10.3 pg/m3 and 2,2’,3,4,4’,5’,6-heptabromodiphenyl ether (10.0 pg/m3. Although indoor and outdoor total polybrominated diphenyl ether concentrations did not significantly differ, the indoor concentrations of 2,4-dibromodiphenyl ether, 2,2’,4-tribromodiphenyl ether, 2,4,4’-tribromodiphenyl ether, 2,2’,4,5’-tetrabromodiphenyl ether and 2,3’,4’,6-tetrabromodiphenyl ether were significantly higher than their outdoor concentrations. This study suggests the following measures: 1 to increase the air exchange rate and open classroom doors and windows for several minutes before classes to reduce indoor PBDE concentrations; 2 to reduce polybrominated diphenyl ether emissions from new devices, it’s better to use computer-related products that meet the Restriction of Hazardous Substances Directive adopted by the European Union.

  6. Solvent effects on the kinetics of the chlorine isotopic exchange reaction between chloride ion and O,O-diphenyl phosphorochloridate or O,O-diphenyl phosphorchloridothioate

    International Nuclear Information System (INIS)

    Mikolajczyk, M.; Slebocka-Tilk, H.; Reimschussel, W.

    1982-01-01

    The effect of solvent on the kinetics of the chlorine isotopic exchange reaction between 36 Cl- ions and O,O-diphenyl phosphorochloridate or O,O-diphenyl phosphorochloridothioate has been investigated in nitromethane, acetonitrile, propylene carbonate, benzonitrile, nitrobenzene, and hexamethyl-phosphoric triamide. The rate constants decrease with increasing electrophilicity of the solvent. A good correlation between the logarithm of the rate constants and acceptor number (AN) of the solvent was obtained with identical slopes for reactions with phosphoryl and thiophosporyl compounds. The slopes for the dependence of ΔH or TΔS vs. AN for chlorine isotopic exchange in (PHO) 2 pace are opposite those for the exchange reaction in (PHO) 2 PSCl, so a constant ratio of k/sub p=O//k/sub p=s/ is observed, resulting from compensation of ΔH by ΔS. The effect of solvent on the initial state (from solubility measurements) and the transition state of the reaction between (PhO) 2 PSCl and the Cl- ion was evaluated. Changes of solvation of (PHO) 2 PSCE have practically no effect on the kinetics of the reactions. Changes of solvation of the chloride ion and of the transition state primarily influence the rate constants and activation parameters of the investigated isotopic-exchange reaction

  7. Polybrominated Diphenyl Ethers and Perfluoroalkyl Substances in Serum of Pregnant Women

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Nielsen, Flemming; Kyhl, Henriette Boye

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs), a group of flame retardants, and perfluoroalkyl substances (PFASs) were analysed in serum samples of pregnant women from Denmark to provide information about their exposure and to study indications of common exposure pathways. The main BDE congener was the ...... of exposure and/or pharmacokinetic and metabolisation processes. PBDE and PFAS concentrations were in the range associated with adverse effects in some epidemiological studies....

  8. Evaluation of hepatic biotransformation of polybrominated diphenyl ethers in the polar bear (Ursus maritimus).

    Science.gov (United States)

    Krieger, Lisa K; Szeitz, András; Bandiera, Stelvio M

    2016-03-01

    Polar bears are at the top of the Arctic marine food chain and are subject to exposure and bioaccumulation of environmental chemicals of concern such as polybrominated diphenyl ethers (PBDEs), which were widely used as flame retardants. The aim of the present study was to evaluate the in vitro oxidative metabolism of 2,2',4,4'-tetrabrominated diphenyl ether (BDE-47) and 2,2',4,4',5-pentabrominated diphenyl ether (BDE-99) by polar bear liver microsomes. The identification and quantification of the hydroxy-brominated diphenyl ethers formed were assessed using an ultra-high performance liquid chromatography-tandem mass spectrometry-based method. Incubation of BDE-47 with archived individual liver microsomes, prepared from fifteen polar bears from northern Canada, produced a total of eleven hydroxylated metabolites, eight of which were identified using authentic standards. The major metabolites were 4'-hydroxy-2,2',4,5'-tetrabromodiphenyl ether and 5'-hydroxy-2,2',4,4'-tetrabromodiphenyl ether. Incubation of BDE-99 with polar bear liver microsomes produced a total of eleven hydroxylated metabolites, seven of which were identified using authentic standards. The major metabolites were 2,4,5-tribromophenol and 4-hydroxy-2,2',3,4',5-pentabromodiphenyl ether. Among the CYP specific antibodies tested, anti-rat CYP2B was found to be the most active in inhibiting the formation of hydroxylated metabolites of both BDE-47 and BDE-99, indicating that CYP2B was the major CYP enzyme involved in the oxidative biotransformation of these two congeners. Our study shows that polar bears are capable of forming multiple hydroxylated metabolites of BDE-47 and BDE-99 in vitro and demonstrates the role of CYP2B in the biotransformation and possibly in the toxicity of BDE-47 and BDE-99 in polar bears. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Photochemical Degradation of Polybrominated Diphenyl Ethers in Micro Photo-Reactor

    Czech Academy of Sciences Publication Activity Database

    Vajglová, Zuzana; Veselý, M.; Křišťál, Jiří; Vychodilová, Hana; Tříska, Jan; Jiřičný, Vladimír

    2012-01-01

    Roč. 42, SI (2012), s. 1378-1382 E-ISSN 1877-7058. [International Congress of Chemical and Process Engineering CHISA 2012 and 15th Conference PRES 2012 /20./. Prague, 25.08.2012-29.08.2012] R&D Projects: GA ČR GA104/09/0880 Institutional support: RVO:67985858 ; RVO:67179843 Keywords : polybrominated diphenyl ethers * micro photo reactor * debromination Subject RIV: CI - Industrial Chemistry, Chemical Engineering

  10. Interaction of polybrominated diphenyl ethers (PBDEs) with anaerobic mixed bacterial cultures isolated from river sediment

    Energy Technology Data Exchange (ETDEWEB)

    Yen, J H; Liao, W C; Chen, W C [Department of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Wang, Y.S., E-mail: yswang@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China)

    2009-06-15

    The degradation of flame retardant polybrominated diphenyl ethers (PBDE), including tetra-brominated diphenyl ether (BDE-47), penta-brominated diphenyl ether (BDE-99 and -100), and hexa-brominated diphenyl ether (BDE-153 and -154), by anaerobic bacterial mixed cultures isolated from river sediment was investigated. The effects of PBDEs on changes of anaerobic bacterial community in sediment culture were also studied. Sediments were collected from Er-Jen River and Nan-Kan River basins, which were both heavily polluted rivers in Taiwan, and bacteria from the sediment samples were enriched before the experiment was conducted. Into the anaerobic bacterial mixed cultures, 0.1 {mu}g/mL of PBDEs was added followed by incubation under 30 deg. C for 70 days. Residues of PBDE were determined by gas chromatography with electron capture detector (GC-ECD), and the changes of bacterial community were analyzed by denaturing gradient gel electrophoresis (DGGE). Less than 20% of PBDEs were degraded after 70 days of incubation in all samples except for BDE-47 from the Nan-Kan River sediment. In that culture, BDE-47 was found to have notably degraded. In particular, after 42 days of incubation; BDE-47 was degraded, suddenly and sharply, to a negligible level on Day 70, and the result was confirmed by a repeated experiment. An interesting result was that although BDE-47 was degraded fast in the Nan-Kan River sediment, the bacterial communities did not shift significantly as we had speculated at Day 70. From UPGMA dendrograms, PBDEs changed the composition of bacterial communities, and the extents varied with the variety of PBDE congeners. By the amendment with BDE-153 or -154, bacterial communities would be changed immediately and irreversibly throughout the rest of the incubation period. No significant difference in degradation of PBDEs was observed between sediment bacteria from Er-Jen River and Nan-Kan River. However, the results verified the persistence of PBDEs in the environment.

  11. Absorption and translocation of polybrominated diphenyl ethers (PBDEs) by plants from contaminated sewage sludge

    Czech Academy of Sciences Publication Activity Database

    Vrkoslavová, J.; Demnerová, K.; Macková, M.; Zemanová, T.; Macek, Tomáš; Hajšlová, J.; Pulkrabová, J.; Hrádková, P.; Stiborová, H.

    2010-01-01

    Roč. 81, č. 3 (2010), s. 381-386 ISSN 0045-6535 R&D Projects: GA MŠk 2B06151 Grant - others:GA ČR(CZ) GP104/08/P188 Institutional research plan: CEZ:AV0Z40550506 Keywords : polybrominated diphenyl ethers * contaminated sewage sludge * plant uptake * bioconcentration factors * Nicotiana tabacum Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.155, year: 2010

  12. Interaction of polybrominated diphenyl ethers (PBDEs) with anaerobic mixed bacterial cultures isolated from river sediment

    International Nuclear Information System (INIS)

    Yen, J.H.; Liao, W.C.; Chen, W.C.; Wang, Y.S.

    2009-01-01

    The degradation of flame retardant polybrominated diphenyl ethers (PBDE), including tetra-brominated diphenyl ether (BDE-47), penta-brominated diphenyl ether (BDE-99 and -100), and hexa-brominated diphenyl ether (BDE-153 and -154), by anaerobic bacterial mixed cultures isolated from river sediment was investigated. The effects of PBDEs on changes of anaerobic bacterial community in sediment culture were also studied. Sediments were collected from Er-Jen River and Nan-Kan River basins, which were both heavily polluted rivers in Taiwan, and bacteria from the sediment samples were enriched before the experiment was conducted. Into the anaerobic bacterial mixed cultures, 0.1 μg/mL of PBDEs was added followed by incubation under 30 deg. C for 70 days. Residues of PBDE were determined by gas chromatography with electron capture detector (GC-ECD), and the changes of bacterial community were analyzed by denaturing gradient gel electrophoresis (DGGE). Less than 20% of PBDEs were degraded after 70 days of incubation in all samples except for BDE-47 from the Nan-Kan River sediment. In that culture, BDE-47 was found to have notably degraded. In particular, after 42 days of incubation; BDE-47 was degraded, suddenly and sharply, to a negligible level on Day 70, and the result was confirmed by a repeated experiment. An interesting result was that although BDE-47 was degraded fast in the Nan-Kan River sediment, the bacterial communities did not shift significantly as we had speculated at Day 70. From UPGMA dendrograms, PBDEs changed the composition of bacterial communities, and the extents varied with the variety of PBDE congeners. By the amendment with BDE-153 or -154, bacterial communities would be changed immediately and irreversibly throughout the rest of the incubation period. No significant difference in degradation of PBDEs was observed between sediment bacteria from Er-Jen River and Nan-Kan River. However, the results verified the persistence of PBDEs in the environment.

  13. A study of oxidative stress induced by two polybrominated diphenyl ethers in the rotifer Brachionus plicatilis.

    Science.gov (United States)

    Zhang, Jing; Wang, You; Sun, Kai-Ming; Fang, Kuan; Tang, Xuexi

    2016-12-15

    Polybrominated diphenyl ethers (PBDEs) are widely dispersed persistent organic pollutants in the marine ecosystem. However, their toxic mechanisms in marine organisms, especially invertebrates, remain poorly understood. Two common congeners of PBDEs, tetrabrominated diphenyl ether-47 (BDE-47) and decabrominated diphenyl ether-209 (BDE-209), were investigated. Their toxic mechanisms, with a focus on oxidative stress, were examined in rotifer Brachionus plicatilis. Overproduction of reactive oxygen species (ROS) was induced by two PBDEs. The expression of superoxide dismutase (SOD) mRNA was increased, suggesting SOD play a main role in ROS-scavenging. The intercellular concentrations of calcium ([Ca 2+ ] in ) and the expression of calmodulin (CaM) mRNA were increased. This indicates the calcium ion (Ca 2+ ) signaling channel is involved in PBDEs stress. Further analysis showed that the reproductive system might be the target site for toxicity of PBDEs. Moreover, high value of detection indexes in BDE-47 experimental groups suggested BDE-47 might cause higher oxidative damage than BDE-209 in rotifers. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Urinary metabolites of phosphate flame retardants in workers occupied with e-waste recycling and incineration.

    Science.gov (United States)

    Yan, Xiao; Zheng, Xiaobo; Wang, Meihuan; Zheng, Jing; Xu, Rongfa; Zhuang, Xi; Lin, Ying; Ren, Mingzhong

    2018-06-01

    Urinary metabolites of phosphate flame retardants (PFRs) were determined in workers from an electronic waste (e-waste) recycling site and an incineration plant, in order to assess the PFR exposure risks of workers occupied with e-waste recycling and incineration. Bis(2-chloroethyl) phosphate (BCEP), bis(1,3-dichloro-2-propyl) phosphate (BDCIPP), and diphenyl phosphate (DPHP) were the most frequently detected chemicals (82-93%). The median concentrations of BCEP, BDCIPP, and DPHP were 1.77, 0.23, and 0.70 ng/mL, and 1.44, 0.22, and 0.11 ng/mL in samples from the e-waste site and the incineration plant, respectively. Dibutyl phosphate (DBP) was detected in all samples from the incineration plant, with a median level of 0.30 ng/mL. The concentrations of BDCIPP (r = -0.31, p waste site. Negative and significant correlations were also observed between the concentrations of BCEP (r = -0.42, p incineration plant. No gender differences were observed in levels of PFR metabolites in urine samples (p > 0.05). Concentrations of BDCIPP in female were significantly correlated with occupational exposure time (r = -0.507, p  0.05). Overall, the workers with occupational exposure to PFRs had different profiles of urinary PFR metabolites. The age, occupational exposure time, and gender seemed not to be main factors mediating the exposure to PFRs for workers occupied with e-waste recycling and incineration. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Antifungal activities of diphenyl diselenide and ebselen alone and in combination with antifungal agents against Fusarium spp.

    Science.gov (United States)

    Venturini, Tarcieli Pozzebon; Chassot, Francieli; Loreto, Érico Silva; Keller, Jéssica Tairine; Azevedo, Maria Izabel; Zeni, Gilson; Santurio, Janio Morais; Alves, Sydney Hartz

    2016-07-01

    Herein, we describe the in vitro activity of a combination of the organoselenium compounds diphenyl diselenide and ebselen alone and in combination with amphotericin B, caspofungin, itraconazole, and voriconazole against 25 clinical isolates of Fusarium spp. For this analysis, we used the broth microdilution method based on the M38-A2 technique and checkerboard microdilution method. Diphenyl diselenide (MIC range = 4-32 μg/ml) and ebselen (MIC range = 2-8 μg/ml) showed in vitro activity against the isolates tested. The most effective combinations were (synergism rates): ebselen + amphotericin B (88%), ebselen + voriconazole (80%), diphenyl diselenide + amphotericin B (72%), and diphenyl diselenide + voriconazole (64%). Combination with caspofungin resulted in low rates of synergism: ebselen + caspofungin, 36%, and diphenyl diselenide + caspofungin, 28%; combination with itraconazole demonstrated indifferent interactions. Antagonistic effects were not observed for any of the combinations tested. Our findings suggest that the antifungal potential of diphenyl diselenide and ebselen deserves further investigation in in vivo experimental models, especially in combination with amphotericin B and voriconazole. © The Author 2016. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Uranium endowments in phosphate rock

    International Nuclear Information System (INIS)

    Ulrich, Andrea E.; Schnug, Ewald; Prasser, Horst-Michael; Frossard, Emmanuel

    2014-01-01

    This study seeks to identify and specify the components that make up the prospects of U recovery from phosphate rock. A systems approach is taken. The assessment includes i) reviewing past recovery experience and lessons learned; ii) identifying factors that determine recovery; and iii) establishing a contemporary evaluation of U endowments in phosphate rock reserves, as well as the available and recoverable amounts from phosphate rock and phosphoric acid production. We find that in the past, recovery did not fulfill its potential and that the breakup of the Soviet Union worsened then-favorable recovery market conditions in the 1990s. We find that an estimated 5.7 million tU may be recoverable from phosphate rock reserves. In 2010, the recoverable tU from phosphate rock and phosphoric acid production may have been 15,000 tU and 11,000 tU, respectively. This could have filled the world U supply-demand gap for nuclear energy production. The results suggest that the U.S., Morocco, Tunisia, and Russia would be particularly well-suited to recover U, taking infrastructural considerations into account. We demonstrate future research needs, as well as sustainability orientations. We conclude that in order to promote investment and production, it seems necessary to establish long-term contracts at guaranteed prices, ensuring profitability for phosphoric acid producers. - Highlights: • We identify components that underlie the recovery of uranium from phosphate rock. • We estimate that 11,000 tU may have been recoverable from phosphoric acid in 2010. • Recovery is a resource conservation and environmental pollution control strategy. • To ensure investment in recovery technology, profitability needs to be secured

  17. Uranium endowments in phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Ulrich, Andrea E., E-mail: andrea.ulrich@env.ethz.ch [Institute for Environmental Decisions (IED), Natural and Social Science Interface, ETH Zurich Universitässtrasse 22, 8092 Zurich (Switzerland); Institute for Agricultural Sciences, Plant Nutrition, ETH Zurich, Eschikon 33, 8315 Lindau (Switzerland); Schnug, Ewald, E-mail: e.schnug@tu-braunschweig.de [Department of Life Sciences, Technical University of Braunschweig, Pockelsstraße 14, D-38106 Braunschweig (Germany); Prasser, Horst-Michael, E-mail: prasser@lke.mavt.ethz.ch [Institute of Energy Technology, Laboratory of Nuclear Energy Systems, ETH Zurich, Sonneggstrasse 3, 8092 Zurich (Switzerland); Frossard, Emmanuel, E-mail: emmanuel.frossard@usys.ethz.ch [Institute for Agricultural Sciences, Plant Nutrition, ETH Zurich, Eschikon 33, 8315 Lindau (Switzerland)

    2014-04-01

    This study seeks to identify and specify the components that make up the prospects of U recovery from phosphate rock. A systems approach is taken. The assessment includes i) reviewing past recovery experience and lessons learned; ii) identifying factors that determine recovery; and iii) establishing a contemporary evaluation of U endowments in phosphate rock reserves, as well as the available and recoverable amounts from phosphate rock and phosphoric acid production. We find that in the past, recovery did not fulfill its potential and that the breakup of the Soviet Union worsened then-favorable recovery market conditions in the 1990s. We find that an estimated 5.7 million tU may be recoverable from phosphate rock reserves. In 2010, the recoverable tU from phosphate rock and phosphoric acid production may have been 15,000 tU and 11,000 tU, respectively. This could have filled the world U supply-demand gap for nuclear energy production. The results suggest that the U.S., Morocco, Tunisia, and Russia would be particularly well-suited to recover U, taking infrastructural considerations into account. We demonstrate future research needs, as well as sustainability orientations. We conclude that in order to promote investment and production, it seems necessary to establish long-term contracts at guaranteed prices, ensuring profitability for phosphoric acid producers. - Highlights: • We identify components that underlie the recovery of uranium from phosphate rock. • We estimate that 11,000 tU may have been recoverable from phosphoric acid in 2010. • Recovery is a resource conservation and environmental pollution control strategy. • To ensure investment in recovery technology, profitability needs to be secured.

  18. Phosphorus release from phosphate rock and iron phosphate by low-molecular-weight organic acids.

    Science.gov (United States)

    Xu, Ren-kou; Zhu, Yong-guan; Chittleborough, David

    2004-01-01

    Low-molecular-weight(LMW) organic acids widely exist in soils, particularly in the rhizosphere. A series of batch experiments were carried out to investigate the phosphorus release from rock phosphate and iron phosphate by low-molecular-weight organic acids. Results showed that citric acid had the highest capacity to solubilize P from both rock and iron phosphate. P solubilization from rock phosphate and iron phosphate resulted in net proton consumption. P release from rock phosphate was positively correlated with the pKa values. P release from iron phosphate was positively correlated with Fe-organic acid stability constants except for aromatic acids, but was notcorrelated with pKa. Increase in the concentrations of organic acids enhanced P solubilization from both rock and iron phosphate almost linearly. Addition of phenolic compounds further increased the P release from iron phosphate. Initial solution pH had much more substantial effect on P release from rock phosphate than from iron phosphate.

  19. Simultaneous Determination of Methoxylated Polybrominated Diphenyl Ethers and Polybrominated Diphenyl Ethers in Water, Soil and Sediment from China by GC-MS.

    Science.gov (United States)

    Hu, Xiaozhong; Hu, Decong; Chen, Wei; Wu, Bin; Lin, Changjun

    2015-09-01

    Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants, which are increasingly reported in the environment. Methoxylated polybrominated diphenyl ethers (MeO-PBDEs) are structural analogs to PBDEs and reported as natural products and novel pollutants present in the environment. First, a new isotopic dilution GC-MS method was developed in this study to simultaneously determine 13 PBDEs and 8 MeO-PBDEs in water, soil and sediment. Liquid/liquid extraction, pressurized liquid extraction and multi-layer silica gel column chromatography cleanup were used, and some important steps and crucial parameters were modified and intensified compared with the other literatures. Besides, the conditions of GC and MS were also optimized. The limits of quantitation values of 0.005-0.1 and 0.02-0.1 µg L(-1) in water were calculated for PBDEs and MeO-PBDEs, respectively; so did 0.25-5 and 1-5 µg kg(-1) dry weight in soil and sediment. In addition, good repeatability and accuracy of the whole method were achieved. Moreover, 60 water and 30 sediment samples for aquaculture crayfish and freshwater fish collected from aquatic products production base, 40 soil samples collected from agricultural products production base and also 20 Yangtze River water samples and 20 Hanjiang River water samples collected from different sampling situations near Wuhan, Hubei province along the Yangtze River and the Hanjiang River were analyzed to determine whether they are contaminated by PBDEs and MeO-PBDEs. Using the established methods, it was found that PBDEs or MeO-PBDEs emerged in 4 of 60 water samples for aquatic products, 3 of 40 soils, and 2 of 30 sediments and in low µg kg(-1) dry weight for soil and sediments and low µg L(-1) for water. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Uranium abundance in some sudanese phosphate ores

    International Nuclear Information System (INIS)

    Adam, A.A.; Eltayeb, M.A.H.

    2009-01-01

    This work was carried out mainly to analysis of some Sudanese phosphate ores, for their uranium abundance and total phosphorus content measured as P 2 O 5 %. For this purpose, 30 samples of two types of phosphate ore from Eastern Nuba Mountains, in Sudan namely, Kurun and Uro areas were examined. In addition, the relationship between uranium and major, and trace elements were obtained, also, the natural radioactivity of the phosphate samples was measured, in order to characterize and differentiate between the two types of phosphate ores. The uranium abundance in Uro phosphate with 20.3% P 2 O 5 is five time higher than in Kurun phosphate with 26.7% P 2 O 5 . The average of uranium content was found to be 56.6 and 310 mg/kg for Kurun and Uro phosphate ore, respectively. The main elements in Kurun and Uro phosphate ore are silicon, aluminum, and phosphorus, while the most abundant trace elements in these two ores are titanium, strontium and barium. Pearson correlation coefficient revealed that uranium in Kurun phosphate shows strong positive correlation with P 2 O 5 , and its distribution is essentially controlled by the variations of P2O5 concentration, whereas uranium in Uro phosphate shows strong positive correlation with strontium, and its distribution is controlled by the variations of Sr concentration. Uranium behaves in different ways in Kurun phosphate and in Uro phosphate. Uro phosphate shows higher concentrations of all the estimated radionuclides than Kurun phosphate. According to the obtained results, it can be concluded that Uro phosphate is consider as secondary uranium source, and is more suitable for uranium recovery, because it has high uranium abundance and low P 2 O 5 %, than Kurun phosphate. (authors) [es

  1. Occurrence and functioning of phosphate solubilizing ...

    African Journals Online (AJOL)

    Occurrence and functioning of phosphate solubilizing microorganisms from oil palm tree ( Elaeis guineensis ) rhizosphere in Cameroon. ... While the use of soluble mineral phosphate fertilizers is the obvious best means to combat phosphate ... in order to improve agricultural production, using low inputs technology. Isolates ...

  2. Occurrence of polybrominated diphenyl ethers (PBDEs) in brown trout bile and liver from Swiss rivers

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Paul C. [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, P.O. Box 611, 8600 Duebendorf (Switzerland); Burkhardt-Holm, Patricia [Department of Environmental Science, University of Basel, Vesalgasse 1, 4051 Basel (Switzerland)]. E-mail: patricia.holm@unibas.ch; Giger, Walter [Eawag, Swiss Federal Institute of Aquatic Science and Technology, Ueberlandstrasse 133, P.O. Box 611, 8600 Duebendorf (Switzerland)]. E-mail: giger@eawag.ch

    2007-03-15

    The ranges of total polybrominated diphenyl ethers (PBDEs) in fish from four Swiss rivers were 0.8-240 ng/g in the bile and 16-7400 ng/g lipid in the liver. PBDE concentrations varied within each river and among the various rivers. Female fish tended to have higher concentrations in the liver, while the male fish had higher concentrations in the bile. From the resulting PBDE concentrations in fish it could not be infered that these contaminants contribute to the causes of the observed fish catch decline in Swiss rivers. - PBDEs with the most abundant BDE-47 were determined in brown trout bile and liver from Swiss rivers.

  3. Occurrence of polybrominated diphenyl ethers (PBDEs) in brown trout bile and liver from Swiss rivers

    International Nuclear Information System (INIS)

    Hartmann, Paul C.; Burkhardt-Holm, Patricia; Giger, Walter

    2007-01-01

    The ranges of total polybrominated diphenyl ethers (PBDEs) in fish from four Swiss rivers were 0.8-240 ng/g in the bile and 16-7400 ng/g lipid in the liver. PBDE concentrations varied within each river and among the various rivers. Female fish tended to have higher concentrations in the liver, while the male fish had higher concentrations in the bile. From the resulting PBDE concentrations in fish it could not be infered that these contaminants contribute to the causes of the observed fish catch decline in Swiss rivers. - PBDEs with the most abundant BDE-47 were determined in brown trout bile and liver from Swiss rivers

  4. Oxidation Reactivity Channels for 2-(Pyridin-2-yl)-N,N-diphenyl-acetamides

    Energy Technology Data Exchange (ETDEWEB)

    Pailloux, Sylvie [University of New Mexico, Albuquerque; Binyamin, Iris [University of New Mexico, Albuquerque; Kim, Sung-jun [University of New Mexico, Albuquerque; Deck, Lorraine M. [University of New Mexico, Albuquerque; Rapko, Brian M. [Pacific Northwest National Laboratory (PNNL); Hay, Benjamin [ORNL; Duesler, Eileen N. [University of New Mexico, Albuquerque; Paine, Robert T. [University of New Mexico, Albuquerque

    2007-11-01

    Synthetic routes to 2-(pyridin-2-yl)-N,N-diphenylacetamide and 2-(6-methylpyridin-2-yl)-N,N-diphenyl-acetamide are described along with results from the chemical oxidation of these compounds with peracetic acid, m-chloroperbenzoic acid, and OXONE. In each case, oxidations generate four products in varying amounts depending on the oxidant and reaction conditions. Each product has been characterized by spectroscopic methods and the molecular structures of several of the new compounds have been confirmed by X-ray crystallography.

  5. Concentrations of organochlorine pesticides, polybrominated diphenyl ethers and perfluorinated compounds in the atmosphere of North Greenland

    DEFF Research Database (Denmark)

    Bossi, Rossana; Vorkamp, Katrin; Skov, Henrik

    2016-01-01

    Atmospheric concentrations of organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs) and neutral per- and polyfluoroalkyl substances (PFAS) have been measured at Villum Research Station, Station Nord (North Greenland) in the period 2008–2013. Atmospheric concentrations of OCPs...... for neutral PFAS we present for the first time a multiyear series of measurements for North Greenland. The average sum of the seven measured neutral PFAS (∑7PFAS) ranged from 1.82 to 32.1 pg m−3. The most abundant compound was 8:2 FTOH (44% of ∑7PFAS), followed by 6:2 FTOH and 10:2 FTOH. Perfluoroalkyl...

  6. 5-Imino-3,4-diphenyl-1H-pyrrol-2-one

    Directory of Open Access Journals (Sweden)

    Evgeny Bulatov

    2014-02-01

    Full Text Available The title compound, C16H12N2O, exists in the crystalline state as the 5-imino-3,4-diphenyl-1H-pyrrol-2-one tautomer. The dihedral angles between the pyrrole and phenyl rings are 35.3 (2 and 55.3 (2°. In the crystal, inversion dimers linked by pairs of N—H...N hydrogen bonds generate a graph-set motif of R22(8 via N—H...N hydrogen bonds.

  7. Zirconium Phosphate Supported MOF Nanoplatelets.

    Science.gov (United States)

    Kan, Yuwei; Clearfield, Abraham

    2016-06-06

    We report a rare example of the preparation of HKUST-1 metal-organic framework nanoplatelets through a step-by-step seeding procedure. Sodium ion exchanged zirconium phosphate, NaZrP, nanoplatelets were judiciously selected as support for layer-by-layer (LBL) assembly of Cu(II) and benzene-1,3,5-tricarboxylic acid (H3BTC) linkers. The first layer of Cu(II) is attached to the surface of zirconium phosphate through covalent interaction. The successive LBL growth of HKUST-1 film is then realized by soaking the NaZrP nanoplatelets in ethanolic solutions of cupric acetate and H3BTC, respectively. The amount of assembled HKUST-1 can be readily controlled by varying the number of growth cycles, which was characterized by powder X-ray diffraction and gas adsorption analyses. The successful construction of HKUST-1 on NaZrP was also supported by its catalytic performance for the oxidation of cyclohexene.

  8. Phosphate-a poison for humans?

    Science.gov (United States)

    Komaba, Hirotaka; Fukagawa, Masafumi

    2016-10-01

    Maintenance of phosphate balance is essential for life, and mammals have developed a sophisticated system to regulate phosphate homeostasis over the course of evolution. However, due to the dependence of phosphate elimination on the kidney, humans with decreased kidney function are likely to be in a positive phosphate balance. Phosphate excess has been well recognized as a critical factor in the pathogenesis of mineral and bone disorders associated with chronic kidney disease, but recent investigations have also uncovered toxic effects of phosphate on the cardiovascular system and the aging process. Compelling evidence also suggests that increased fibroblastic growth factor 23 and parathyroid hormone levels in response to a positive phosphate balance contribute to adverse clinical outcomes. These insights support the current practice of managing serum phosphate in patients with advanced chronic kidney disease, although definitive evidence of these effects is lacking. Given the potential toxicity of excess phosphate, the general population may also be viewed as a target for phosphate management. However, the widespread implementation of dietary phosphate intervention in the general population may not be warranted due to the limited impact of increased phosphate intake on mineral metabolism and clinical outcomes. Nonetheless, the increasing incidence of kidney disease or injury in our aging society emphasizes the potential importance of this issue. Further work is needed to more completely characterize phosphate toxicity and to establish the optimal therapeutic strategy for managing phosphate in patients with chronic kidney disease and in the general population. Copyright © 2016 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.

  9. Thermal and Optical Properties of New Poly(amide-imide)/Nanocomposite Reinforced by Layer Silicate Containing Diphenyl Ether Moieties

    Science.gov (United States)

    Faghihi, Khalil; Faramarzi, Ellahe; Shabanian, Meisam

    2011-04-01

    New poly(amide-imide)-montmorillonite reinforced nanocomposites containing Bis(4-N-trimellitylimido) diphenyl ether moiety in the main chain were synthesized by a convenient solution intercalation technique. Poly(amide-imide) (PAI) 4 was synthesized by the direct polycondensation reaction of Bis(4-N-trimellitylimido) diphenyl ether 3 with 4,4'-diamino diphenyl ether 2 in the presence of triphenyl phosphite (TPP), CaCl2, pyridine and N-methyl-2-pyrrolidone (NMP). Morphology and structure of the resulting PAI-nanocomposite films 4a and 4b with 10 and 20 mass% silicate particles respectively, were characterized by FT-IR spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The properties of nanocomposites films were investigated by using Uv-vis spectroscopy, thermogravimetric analysis (TGA) and water uptake measurements.

  10. Concentrations and speciation of polybrominated diphenyl ethers in human amniotic fluid

    Science.gov (United States)

    Miller, Mark F.; Chernyak, Sergei M.; Domino, Steven E.; Batterman, Stuart A.; Loch-Caruso, Rita

    2012-01-01

    Polybrominated diphenyl ethers (PBDEs) are persistent organic chemicals used as flame retardants in textiles, plastics, and consumer products. Although PBDE accumulation in humans has been noted since the 1970s, few studies have investigated PBDEs within the gestational compartment, and none to date has identified levels in amniotic fluid. The present study reports congener-specific brominated diphenyl ether (BDE) concentrations in second-trimester clinical amniotic fluid samples collected in 2009 from fifteen women in southeast Michigan, USA. Twenty-one BDE congeners were measured by GC/MS/NCI. The average total PBDE concentration was 3795 pg/ml amniotic fluid (range: 337 – 21842 pg/ml). BDE-47 and BDE-99 were identified in all samples. Based on median concentrations, the dominant congeners were BDE-208, 209, 203, 206, 207, and 47 representing 23, 16, 12, 10, 9 and 6%, respectively, of the total detected PBDEs. PBDE concentrations were identified in all amniotic fluid samples from southeast Michigan, supporting a need for further investigations of fetal exposure pathways and potential impacts on perinatal health. PMID:22236635

  11. Polybrominated diphenyl ethers in articles: a review of its applications and legislation.

    Science.gov (United States)

    Jinhui, Li; Yuan, Chen; Wenjing, Xiao

    2017-02-01

    Polybrominated diphenyl ethers (PBDEs), especially commercial decabrominated diphenyl ethers (c-decaBDE), have been widely produced and applied to numerous materials because of their highly effective flame-retardant capabilities. The production of commercial pentaBDE (c-pentaBDE) and commercial octaBDE (c-octaBDE) ended in 2004 because they are persistent, bioaccumulative, and toxic to both humans and the environment, but decaBDE production and use continue. Furthermore, many congeners of PBDEs are still prevalent in consumer products and articles that they pose enormous threat to both the environment and human health. PBDEs have been detected in the casing of electrical and electronic equipment, textile materials, automotive interiors, polyurethane foam (PUF) in seat cushions, children's toys, kitchenware, and other products. With increasing evidence about PBDE pollution and the adoption of international conventions, many developed countries have drawn more public attention to PBDEs and developed sound strategies for their management. This review summaries the utilization and management of PBDEs in a number of countries and reaches the conclusion that PBDEs are still prevalent in consumer articles, while specific regulations or policies for articles containing PBDEs are rare. Public awareness should be raised on the importance of sound management of articles containing PBDEs.

  12. Fate of polybrominated diphenyl ethers in the environment of the Pearl River Estuary, South China

    International Nuclear Information System (INIS)

    Guan Yufeng; Sojinu, O.S. Samuel; Li Shaomeng; Zeng, Eddy Y.

    2009-01-01

    Ninety-six riverine runoff samples collected at eight major outlets in the Pearl River Delta (PRD), South China, during 2005-2006 were analyzed for 17 brominated diphenyl ether (BDE) congeners (defined as Σ 17 PBDE). Fourteen and 15 congeners were detected, respectively, in the dissolved and particulate phases. These data were further used to elucidate the partitioning behavior of BDE congeners in riverine runoff. Several related fate processes, i.e. air-water exchange, dry and wet deposition, degradation, and sedimentation, within the Pearl River Estuary (PRE), were examined to estimate the inputs of Σ 10 PBDE (sum of the target BDE congeners, BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, and -183) and BDE-209 from the PRD to the coastal ocean based on mass balance considerations. The results showed that annual outflows of Σ 10 PBDE and BDE-209 were estimated at 126 and 940 kg/year, respectively from the PRE to coastal ocean. Besides sedimentation and degradation, the majority of Σ 10 PBDE and BDE-209 discharged into the PRE via riverine runoff was transported to the coastal ocean. - Fate of polybrominated diphenyl ethers in the environment the Pearl River Estuary, South China.

  13. Polybrominated diphenyl ethers (PBDEs) in feathers of colonial water-bird species from Pakistan

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Riffat Naseem, E-mail: r_n_malik2000@yahoo.co.uk [Environmental Biology Laboratory, Department of Plant Sciences, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, PO 45320 (Pakistan); Moeckel, Claudia [Centre for Ecology and Hydrology, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA1 4AP (United Kingdom); Jones, Kevin C.; Hughes, David [Centre for Chemicals Management, Lancaster Environment Centre, Lancaster University, Bailrigg, Lancaster LA1 4YQ (United Kingdom)

    2011-10-15

    Feathers of two colonial water-birds species (Bubulcus ibis, Egretta garzetta) from four heronries in the Punjab province, Pakistan were analysed for 28 Polybrominated Diphenyl Ethers (PBDEs) congeners. Median concentrations of {Sigma}PBDEs were 2.41 and 1.91 ng/g in little and cattle egrets. PBDE-47, -100, -138, -153 were abundant and detected in >70% of feather samples in both species. Species-specific differences based on dietary preferences indicated higher concentration of PBDE-47, -66, -75, -100, -153, -154, and -183 in fish eating little egret. BDE-47 and -100 were more frequent in little egrets and BDE-99 was more dominant in cattle egret which feed on terrestrial habitat. Higher {Sigma}hexa- and hepta-BDEs congeners showed larger concentrations in feathers from heronries close to water bodies which receive urban and industrial effluents whereas lower-brominated congeners (BDE-47-BDE-100) dominated in rural/agricultural regions. Hazard quotients (HQs) indicated that measured {Sigma}PBDEs pose no risk to egret population. - Highlights: > Feathers as non-destructive tool to asses Polybrominated Diphenyl Ethers (PBDEs) contamination. > PBDE-47 and -100 frequent in feathers of fish eating egrets. > BDE-99 dominant in feathers of egrets feed in terrestrial habitats. > Lower-brominated congeners (BDE-47-BDE-100) dominate in feathers from rural areas. > Greater contents of hexa- and hepta-BDEs in feathers from areas receive urban/industrial effluents. - Feathers are used as a biomonitoring tool for PBDEs contamination.

  14. Polybrominated diphenyl ethers (PBDEs) in feathers of colonial water-bird species from Pakistan

    International Nuclear Information System (INIS)

    Malik, Riffat Naseem; Moeckel, Claudia; Jones, Kevin C.; Hughes, David

    2011-01-01

    Feathers of two colonial water-birds species (Bubulcus ibis, Egretta garzetta) from four heronries in the Punjab province, Pakistan were analysed for 28 Polybrominated Diphenyl Ethers (PBDEs) congeners. Median concentrations of ΣPBDEs were 2.41 and 1.91 ng/g in little and cattle egrets. PBDE-47, -100, -138, -153 were abundant and detected in >70% of feather samples in both species. Species-specific differences based on dietary preferences indicated higher concentration of PBDE-47, -66, -75, -100, -153, -154, and -183 in fish eating little egret. BDE-47 and -100 were more frequent in little egrets and BDE-99 was more dominant in cattle egret which feed on terrestrial habitat. Higher Σhexa- and hepta-BDEs congeners showed larger concentrations in feathers from heronries close to water bodies which receive urban and industrial effluents whereas lower-brominated congeners (BDE-47-BDE-100) dominated in rural/agricultural regions. Hazard quotients (HQs) indicated that measured ΣPBDEs pose no risk to egret population. - Highlights: → Feathers as non-destructive tool to asses Polybrominated Diphenyl Ethers (PBDEs) contamination. → PBDE-47 and -100 frequent in feathers of fish eating egrets. → BDE-99 dominant in feathers of egrets feed in terrestrial habitats. → Lower-brominated congeners (BDE-47-BDE-100) dominate in feathers from rural areas. → Greater contents of hexa- and hepta-BDEs in feathers from areas receive urban/industrial effluents. - Feathers are used as a biomonitoring tool for PBDEs contamination.

  15. Brominated diphenyl ethers in the sediments, porewater, and biota of the Chesapeake Bay, USA

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K.; Klosterhaus, S.; Liebert, D.; Stapleton, H. [Maryland Univ., Solomons, MD (United States)

    2004-09-15

    Levels of brominated diphenyl ethers (BDEs) are rapidly increasing in the environment, and in a short time these chemicals have evolved from 'emerging contaminants' to globally-distributed organic pollutants. Recent research demonstrates BDEs are sufficiently stable to be transported long distances in the environment and to accumulate in higher trophic levels. Photolysis and metabolism appear to be dominant loss processes for the parent compounds, generating a variety of lower brominated diphenyl ethers, hydroxylated metabolites, and other products. BDEs are hydrophobic, and therefore their transport in aquatic systems is likely controlled by sorption to sediments and perhaps exchange across the air-water interface. To date, few studies have examined the geochemistry of BDEs in natural waters. In this paper, we review our recent measurements of BDEs in the Chesapeake Bay, a shallow, productive estuary in eastern North America. We focus on the distribution of BDE congeners sediment, porewater, and in faunal benthos along a contamination gradient downstream from a wastewater treatment plant and on the spatial distribution of BDEs in bottom-feeding and pelagic fish species.

  16. Levels and distribution of polybrominated diphenyl ethers in various tissues of birds of prey

    International Nuclear Information System (INIS)

    Voorspoels, Stefan; Covaci, Adrian; Lepom, Peter; Jaspers, Veerle L.B.; Schepens, Paul

    2006-01-01

    In the present study, concentrations and tissue distribution of polybrominated diphenyl ethers (PBDEs; IUPAC nos. 28, 47, 99, 100, 153, 154, 183, and 209) were examined in brain, adipose tissue, liver, muscle, and serum of birds of prey. Median ΣPBDE levels (BDE 28-183) in the tissues of sparrowhawks ranged from 360 to 1900 ng/g lipid weight (lw), which was in general one order of magnitude higher than in the tissues of common buzzards (26-130 ng/g lw). There were no differences in PBDE congener patterns between the various tissues within individuals of a certain species. Inter-species differences in PBDE patterns and in particular the percentage of BDE 99, 100 and 153 were, however, pronounced between sparrowhawk and common buzzard. BDE 209 was detected in nearly all serum and in some liver samples, but not in any other tissues. This observation suggests that exposure to BDE 209 is low or that this congener is poorly accumulated. Passive (lipid content related) diffusion could not completely describe the PBDE tissue distribution, e.g. the lowest PBDE-load was measured in brain, a fairly lipid rich tissue. - Distribution of polybrominated diphenyl ethers in birds of prey is tissue dependent

  17. Determination and prediction of octanol-air partition coefficients of hydroxylated and methoxylated polybrominated diphenyl ethers.

    Science.gov (United States)

    Zhao, Hongxia; Xie, Qing; Tan, Feng; Chen, Jingwen; Quan, Xie; Qu, Baocheng; Zhang, Xin; Li, Xiaona

    2010-07-01

    The octanol-air partition coefficient (K(OA)) of 19 hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and 10 methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were measured as a function of temperature using a gas chromatographic retention time technique. At room temperature (298.15K), log K(OA) ranged from 8.30 for monobrominated OH/MeO-PBDEs to 13.29 for hexabrominated OH/MeO-PBDEs. The internal energies of phase change from octanol to air (Delta(OA)U) for 29 OH/MeO-PBDE congeners ranged from 72 to 126 kJ mol(-1). Using partial least-squares (PLS) analysis, a statistically quantitative structure-property relationship (QSPR) model for logK(OA) of OH/MeO-PBDE congeners was developed based on the 16 fundamental quantum chemical descriptors computed by PM3 Hamiltonian, for which the Q(cum)(2) was about 0.937. The molecular weight (Mw) and energy of the lowest unoccupied molecular orbital (E(LUMO)) were found to be main factors governing the log K(OA). 2010 Elsevier Ltd. All rights reserved.

  18. Bioaccumulation of polybrominated diphenyl ethers (PBDEs) in sediment aged for 2 years to carps (Cyprinus carpio)

    Science.gov (United States)

    Tian, S. Y.; Li, J. Y.; Jia, X. M.

    2017-08-01

    In order to understand the risk of polybrominated diphenyl ethers (PBDEs) existing in sediment for years, the accumulation of PBDEs in sediment aged for 2 years to fish was investigated. Simulated aquatic system microcosms were conducted with PBDE contaminated sediment aged for 2 years and carps were cultured in the microcosms for 20 days. PBDE concentrations in carp tissues were analyzed to estimate the bioavailability of aged PBDEs in carps. The main spiked PBDE congeners were detected in sediment even though the contaminated sediment was aged for 2 years. Similarly, the five PBDE (BDE-28, 47, 100, 153 and 154) congeners which probably were bioaccumulated by carp were detected in fish tissues, indicating that PBDEs could be bioaccumulated after aging for 2 years. The PBDEs distribution revealed that the concentrations of polybrominated diphenyl ethers in tissues of Cyprinus carpio is in this order of magnitude: gut > liver > gill > fillet. The PBDEs concentrations in fillet were as high as 67.9 ng/g dry wt, in which BDE-47 contributed almost 50% in profile.

  19. Determination of average molecular weights on organic reactor coolants. II.-Freezing point depression method for diphenyl-ether solutions

    International Nuclear Information System (INIS)

    Carreira, M.

    1965-01-01

    In order to reduce limitations of solubility, the cryoscopic method developed for benzene solutions of polyphenyl mixtures has been extended to diphenyl-ether solutions by introducing some modifications imposed by the physico-chemical properties of this solvent. The Nernsto theory of Beckman's method has been revised, taking into account the heat-transfer characteristics of the system, and the results of that analysis have been used to fix upon the design parameters of a cryoscopic apparatus for measurements on diphenyl-ether solutions. (Author) 9 refs

  20. Photochemical Formation of Hydroxylated Polybrominated Diphenyl Ethers (OH-PBDEs) from Polybrominated Diphenyl Ethers (PBDEs) in Aqueous Solution under Simulated Solar Light Irradiation.

    Science.gov (United States)

    Zhao, Qian; Zhao, Huimin; Quan, Xie; He, Xin; Chen, Shuo

    2015-08-04

    Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) are of great concern due to their higher toxicity compared to PBDEs. However, the abiologic process whereby PBDEs are converted to OH-PBDEs in the aquatic environment is not well understood. To explore the possibility of OH-PBDEs photoformation in natural water, the photohydroxylation of BDE-47 has been investigated in aqueous Fe(III) and/or fulvic acid (FA) solutions and in natural lake water under simulated solar light irradiation. The results showed that 6-OH-BDE-47 and 2'-OH-BDE-68 were generated from BDE-47 under these conditions. Based on the identification of derivatives and reactive radicals, OH-PBDEs formation can be ascribed to an addition reaction of ortho-tetra-BDE radical and hydroxyl radical ((•)OH), with or without a subsequent Smiles rearrangement reaction. Since the ortho-tetra-BDE radical could be readily produced by the photolysis of BDE-47, even in pure water, (•)OH production was considered as critical for the photoformation of OH-PBDEs. Thus, it is reasonable to deduce that the photoreactive components (Fe(III), FA) in aqueous solution played an important role through influencing (•)OH generation. Although the yields of OH-PBDEs did not increase regularly with increasing concentration of these photoreactive components in solution, this study suggests a possible abiotic origin of OH-PBDEs formation in the aquatic environment.

  1. Triphenyl phosphate-induced developmental toxicity in zebrafish: Potential role of the retinoic acid receptor

    Energy Technology Data Exchange (ETDEWEB)

    Isales, Gregory M.; Hipszer, Rachel A.; Raftery, Tara D. [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States); Chen, Albert; Stapleton, Heather M. [Division of Environmental Sciences and Policy, Nicholas School of the Environment, Duke University, Durham, NC (United States); Volz, David C., E-mail: volz@mailbox.sc.edu [Department of Environmental Health Sciences, Arnold School of Public Health, University of South Carolina, Columbia, SC (United States)

    2015-04-15

    Highlights: • Triphenyl phosphate-induced toxicity in zebrafish embryos is enhanced in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate uptake or metabolism within zebrafish embryos is not altered in the presence of a retinoic acid receptor antagonist. • Triphenyl phosphate decreases expression of cytochrome P450 26a1 in zebrafish embryos. • Triphenyl phosphate inhibits retinoic acid-induced activation of human retinoic acid receptors. - Abstract: Using zebrafish as a model, we previously reported that developmental exposure to triphenyl phosphate (TPP) – a high-production volume organophosphate-based flame retardant – results in dioxin-like cardiac looping impairments that are independent of the aryl hydrocarbon receptor. Using a pharmacologic approach, the objective of this study was to investigate the potential role of retinoic acid receptor (RAR) – a nuclear receptor that regulates vertebrate heart morphogenesis – in mediating TPP-induced developmental toxicity in zebrafish. We first revealed that static exposure of zebrafish from 5–72 h post-fertilization (hpf) to TPP in the presence of non-toxic concentrations of an RAR antagonist (BMS493) significantly enhanced TPP-induced toxicity (relative to TPP alone), even though identical non-toxic BMS493 concentrations mitigated retinoic acid (RA)-induced toxicity. BMS493-mediated enhancement of TPP toxicity was not a result of differential TPP uptake or metabolism, as internal embryonic doses of TPP and diphenyl phosphate (DPP) – a primary TPP metabolite – were not different in the presence or absence of BMS493. Using real-time PCR, we then quantified the relative change in expression of cytochrome P450 26a1 (cyp26a1) – a major target gene for RA-induced RAR activation in zebrafish – and found that RA and TPP exposure resulted in a ∼5-fold increase and decrease in cyp26a1 expression, respectively, relative to vehicle-exposed embryos. To address whether TPP may

  2. Phosphate vibrations as reporters of DNA hydration

    Science.gov (United States)

    Corcelli, Steven

    The asymmetric phosphate stretch vibrational frequency is extraordinarily sensitive to its local solvent environment. Using density functional theory calculations on the model compound dimethyl phosphate, the asymmetric phosphate stretch vibrational frequency was found to shift linearly with the magnitude of an electric field along the symmetry axis of the PO2 moiety (i.e. the asymmetric phosphate stretch is an excellent linear vibrational Stark effect probe). With this linear relationship established, asymmetric phosphate stretch vibrational frequencies were computed during the course of a molecular dynamics simulation of fully hydrated DNA. Moreover, contributions to shifts in the frequencies from subpopulations of water molecules (e.g. backbone, minor groove, major groove, etc.) were calculated to reveal how phosphate vibrations report the onset of DNA hydration in experiments that vary the relative humidity of non-condensing (dry) DNA samples.

  3. Application of Calcium Phosphate Materials in Dentistry

    Directory of Open Access Journals (Sweden)

    Jabr S. Al-Sanabani

    2013-01-01

    Full Text Available Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1 application of calcium phosphate into various fields in dentistry; (2 improving mechanical properties of calcium phosphate; (3 biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

  4. Crystalline cerium(IV) phosphates

    International Nuclear Information System (INIS)

    Herman, R.G.; Clearfield, A.

    1976-01-01

    The ion exchange behaviour of seven crystalline cerium(IV) phosphates towards some of the alkali metal cations is described. Only two of the compounds (A and C) possess ion exchange properties in acidic solutions. Four others show some ion exchange characteristics in basic media with some of the alkali cations. Compound G does not behave as an ion exchanger in solutions of pH + , but show very little Na + uptake. Compound E undergoes ion exchange with Na + and Cs + , but not with Li+. Both Li + and Na + are sorbed by compounds A and C. The results are indicative of structures which show steric exclusion phenomena. (author)

  5. Radiological impact of use of phosphate fertilizers

    International Nuclear Information System (INIS)

    Shukla, V.K.; Chinnaesakki, S.; Sartandel, S.J.; Shanbhag, A.A.; Puranik, V.D.

    2003-01-01

    The paper describes the results of gamma spectrometric measurements of 238 U, 233 Th, 226 Ra and 40 K in rock phosphates and various types of phosphate fertilizers and by-products. The increase in soil natural radioactivity has been assessed for major Indian crops. No significant increase in soil natural radioactivity is expected due to the application of phosphate fertilizers for agricultural productions. (author)

  6. Uranium and heavy metals in phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, Ashraf E.M.; King Saud University, Riyadh

    2008-01-01

    Full text: Agricultural applications of chemical fertilizers are a worldwide practice. The specific activity of uranium-238 and heavy metals in phosphate fertilizers depends on the phosphate ore from which the fertilizer produced and on the chemical processing of the ore. Composite phosphate fertilizers samples were collected and the uranium-238 specific activity, in Bq/kg, and As, Cd, Cu, Pb, Se concentration were measured. The annual addition of these elements in soil due to soil fertilization were calculated and discussed. (author)

  7. Calcium phosphates: what is the evidence?

    Science.gov (United States)

    Larsson, Sune

    2010-03-01

    A number of different calcium phosphate compounds such as calcium phosphate cements and solid beta-tricalcium phosphate products have been introduced during the last decade. The chemical composition mimics the mineral phase of bone and as a result of this likeness, the materials seem to be remodeled as for normal bone through a cell-mediated process that involves osteoclastic activity. This is a major difference when compared with, for instance, calcium sulphate compounds that after implantation dissolve irrespective of the new bone formation rate. Calcium phosphates are highly biocompatible and in addition, they act as synthetic osteoconductive scaffolds after implantation in bone. When placed adjacent to bone, osteoid is formed directly on the surface of the calcium phosphate with no soft tissue interposed. Remodeling is slow and incomplete, but by adding more and larger pores, like in ultraporous beta-tricalcium phosphate, complete or nearly complete resorption can be achieved. The indications explored so far include filling of metaphyseal fracture voids or bone cysts, a volume expander in conjunction with inductive products, and as a carrier for various growth factors and antibiotics. Calcium phosphate compounds such as calcium phosphate cement and beta-tricalcium phosphate will most certainly be part of the future armamentarium when dealing with fracture treatment. It is reasonable to believe that we have so far only seen the beginning when it comes to clinical applications.

  8. Biosynthesis and characterization of layered iron phosphate

    International Nuclear Information System (INIS)

    Zhou Weijia; He Wen; Wang Meiting; Zhang Xudong; Yan Shunpu; Tian Xiuying; Sun Xianan; Han Xiuxiu; Li Peng

    2008-01-01

    Layered iron phosphate with uniform morphology has been synthesized by a precipitation method with yeast cells as a biosurfactant. The yeast cells are used to regulate the nucleation and growth of layered iron phosphate. The uniform layered structure is characterized by small-angle x-ray diffraction (SAXD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses. Fourier transform infrared spectroscopy (FT-IR) is used to analyze the chemical bond linkages in organic–inorganic hybrid iron phosphate. The likely synthetic mechanism of nucleation and oriented growth is discussed. The electrical conductivity of hybrid iron phosphate heat-treated at different temperatures is presented

  9. [Phosphate-solubilizing activity of aerobic methylobacteria].

    Science.gov (United States)

    Agafonova, N V; Kaparullina, E N; Doronina, N V; Trotsenko, Iu A

    2014-01-01

    Phosphate-solubilizing activity was found in 14 strains of plant-associated aerobic methylobacteria belonging to the genera Methylophilus, Methylobacillus, Methylovorus, Methylopila, Methylobacterium, Delftia, and Ancyclobacter. The growth of methylobacteria on medium with methanol as the carbon and energy source and insoluble tricalcium phosphate as the phosphorus source was accompanied by a decrease in pH due to the accumulation of up to 7 mM formic acid as a methanol oxidation intermediate and by release of 120-280 μM phosphate ions, which can be used by both bacteria and plants. Phosphate-solubilizing activity is a newly revealed role of methylobacteria in phytosymbiosis.

  10. Synthesis of amorphous acid iron phosphate nanoparticles

    International Nuclear Information System (INIS)

    Palacios, E.; Leret, P.; Fernández, J. F.; Aza, A. H. De; Rodríguez, M. A.

    2012-01-01

    A simple method to precipitate nanoparticles of iron phosphate with acid character has been developed in which the control of pH allows to obtain amorphous nanoparticles. The acid aging of the precipitated amorphous nanoparticles favored the P–O bond strength that contributes to the surface reordering, the surface roughness and the increase of the phosphate acid character. The thermal behavior of the acid iron phosphate nanoparticles has been also studied and the phosphate polymerization at 400 °C produces strong compacts of amorphous nanoparticles with interconnected porosity.

  11. Atmospheric concentrations of organochlorine pesticides, polybrominated diphenyl ethers and polychloronaphthalenes in Nuuk, South-West Greenland

    DEFF Research Database (Denmark)

    Bossi, Rossana; Skov, Henrik; Vorkamp, Katrin

    2008-01-01

    Atmospheric concentrations of organochlorine pesticides (OCs), polybrominated diphenyl ethers (PBDEs) and polychloronaphthalenes (PCNs) were measured for the first time in Nuuk, Greenland in 2004 and 2005. The annual mean concentrations af the measured OCs were: α-HCH 20.2 pg m-3, Υ-HCH (lindane) 5......-HCH, which had maximum concentration in August in both years. The average annual mean for ΣPBDEs was 1.14 ± 0.81 pg m-3. The predominant congeners measured in Nuuk were BDE-47 and BDE-99 followed by BDE-100, -153 and -28, indicating the use of penta-BDE technical products as the main source. A clear seasonal...

  12. Interaction of polybrominated diphenyl ethers and aerobic granular sludge: biosorption and microbial degradation.

    Science.gov (United States)

    Ni, Shou-Qing; Cui, Qingjie; Zheng, Zhen

    2014-01-01

    As a new category of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs) have become ubiquitous global environmental contaminants. No literature is available on the aerobic biotransformation of decabromodiphenyl ether (BDE-209). Herein, we investigated the interaction of PBDEs with aerobic granular sludge. The results show that the removal of BDE-209 from wastewater is mainly via biosorption onto aerobic granular sludge. The uptake capacity increased when temperature, contact time, and sludge dosage increased or solution pH dropped. Ionic strength had a negative influence on BDE-209 adsorption. The modified pseudo first-order kinetic model was appropriate to describe the adsorption kinetics. Microbial debromination of BDE-209 did not occur during the first 30 days of operation. Further study found that aerobic microbial degradation of 4,4(')-dibromodiphenyl ether happened with the production of lower BDE congeners.

  13. Polybrominated diphenyl ethers (PBDEs) in the indoor environment and associations with prenatal exposure

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Thomsen, Marianne; Frederiksen, Marie

    2011-01-01

    As part of a larger exposure study, samples of dust and indoor air were collected in the homes of 43 pregnant women living in the Copenhagen area (Denmark) and analysed for 12 polybrominated diphenyl ethers using GC-MS. A second dust sample collected after delivery was analysed for BDE-183 and BDE...... established geographical differences between continental Europe and North America. Additional octa- and nonaBDE congeners (BDE-197, BDE-203, BDE-206, BDE-207, and BDE-208) were analysed in dust and analytical issues were discussed as these congeners also can be a product of thermal degradation of BDE-209...... further in this study. For all matrices, the PBDE profile resembled that of the technical product Bromkal 70-5DE, but air contained higher percentages of the lower brominated congeners and placenta tissue was dominated by BDE-153. The predominance of BDE-153 has been described in other studies on human...

  14. Occurrence of polybrominated diphenyl ethers (PBDEs) in foodstuffs in Italy and implications for human exposure.

    Science.gov (United States)

    Martellini, Tania; Diletti, Gianfranco; Scortichini, Giampiero; Lolini, Meri; Lanciotti, Eudes; Katsoyiannis, Athanasios; Cincinelli, Alessandra

    2016-03-01

    Polybrominated diphenyl ethers (PBDEs) were determined in various foodstuffs in Italy and the dietary intake was estimated. PBDEs were detected in all analysed samples at concentrations that spanned over five orders of magnitude. The most abundant congeners were the BDE-209, followed by BDE-47 and BDE-99. Fish oil and milk samples showed the highest PBDE concentrations among all samples. The daily dietary intake values were found to be in good agreement or higher to literature values, impacted mainly from the contribution of the analysed dairy products. The cancer risk values estimated for BDE-209 indicated that this specific risk associated with the studied foodstuffs is limited. Italy is one of the world-leading countries in the production of furniture and clothes and has extremely developed medium enterprise industrial sector, where PBDEs were historically used suggesting that their occurrence may be linked to these activities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Interaction of Polybrominated Diphenyl Ethers and Aerobic Granular Sludge: Biosorption and Microbial Degradation

    Directory of Open Access Journals (Sweden)

    Shou-Qing Ni

    2014-01-01

    Full Text Available As a new category of persistent organic pollutants, polybrominated diphenyl ethers (PBDEs have become ubiquitous global environmental contaminants. No literature is available on the aerobic biotransformation of decabromodiphenyl ether (BDE-209. Herein, we investigated the interaction of PBDEs with aerobic granular sludge. The results show that the removal of BDE-209 from wastewater is mainly via biosorption onto aerobic granular sludge. The uptake capacity increased when temperature, contact time, and sludge dosage increased or solution pH dropped. Ionic strength had a negative influence on BDE-209 adsorption. The modified pseudo first-order kinetic model was appropriate to describe the adsorption kinetics. Microbial debromination of BDE-209 did not occur during the first 30 days of operation. Further study found that aerobic microbial degradation of 4,4′-dibromodiphenyl ether happened with the production of lower BDE congeners.

  16. Polybrominated diphenyl ethers in South China maternal and fetal blood and breast milk

    Energy Technology Data Exchange (ETDEWEB)

    Bi Xinhui [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Qu Weiyue [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Sheng Guoying [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); School of Environment and Chemical Engineering, Shanghai University, Shanghai 200072 (China); Zhang Wenbing [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Mai Bixian [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen Dunjin [Obstetrical and Gynecological Institute, Guangzhou Second People' s Hospital, Guangzhou 510150 (China); Yu Lin [Obstetrical and Gynecological Institute, Guangzhou Second People' s Hospital, Guangzhou 510150 (China); Fu Jiamo [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China) and School of Environment and Chemical Engineering, Shanghai University, Shanghai 200072 (China)]. E-mail: fujm@gig.ac.cn

    2006-12-15

    Twenty-one-paired human fetal and maternal serum and 27 breast milk samples at South China were analyzed for concentrations of polybrominated diphenyl ethers (PBDEs). Seven PBDE congeners (BDE-28, -47, -99, -100, -153, -154, and -183) were quantified using gas chromatography/mass spectrometry (GC/MS). This is the first report to present the residue levels of PBDEs in human samples of China. The concentrations of total PBDEs ranged from 1.5 to 17 ng/g in the samples and were within the range reported in European samples for a similar population, but lower than human tissue levels in North America. BDE-47 and -153 were the dominant PBDE congeners in all samples and accounted for 60% of the total PBDEs. Further research is needed to determine the exposure route of PBDEs and their health effects. - A survey of PBDE concentrations in human blood and milk helps identify background concentrations in South China population.

  17. Polybrominated diphenyl ethers--plasma levels and thyroid status of workers at an electronic recycling facility.

    Science.gov (United States)

    Julander, A; Karlsson, M; Hagström, K; Ohlson, C G; Engwall, M; Bryngelsson, I-L; Westberg, H; van Bavel, B

    2005-08-01

    Personnel working with electronic dismantling are exposed to polybrominated diphenyl ethers (PBDEs), which in animal studies have been shown to alter thyroid homeostasis. The aim of this longitudinal study was to measure plasma level of PBDEs in workers at an electronic recycling facility and to relate these to the workers' thyroid status. PBDEs and three thyroid hormones: triiodothyronine (T(3)), thyroxin (T(4)) and thyroid stimulating hormone (TSH) were repeatedly analysed in plasma from 11 workers during a period of 1.5 years. Plasma levels of PBDEs at start of employment were plasma levels of PBDEs fluctuated during the study period. Due to small changes in thyroid hormone levels it was concluded that no relevant changes were present in relation to PBDE exposure within the workers participating in this study.

  18. Current levels of primary polybrominated diphenyl ethers (PBDEs) in Norwegian seafood

    Energy Technology Data Exchange (ETDEWEB)

    Bethune, C.; Nielsen, J.; Julshamn, K. [National Institute of Nutrition and Seafood Research, Bergen (Norway)

    2004-09-15

    The brominated flame retardants (BFRs) represent major industrial chemicals whose use has increased dramatically over the past few decades. Polybrominated diphenyl ethers (PBDEs) are BFRs that are used in many types of consumer products. PBDEs have come to the attention of regulators and scientists due to their bioaccumulation, increasing exposure and persistence in the environment, and adverse health effects in animals and humans. Although PBDE contamination in marine fish was first detected in Sweden in 1979, and certain PBDEs are now banned as of this year, the European Union has yet to establish regulations on PBDE levels in either feed or seafood. The determination of these contaminants in consumer seafood is important for dietary exposure assessment and protection of human health. This study reports on the levels of 6 prominent PBDE congeners (28, 47, 99, 100, 153, and 154) in a selection of common Norwegian seafood.

  19. An effort for reducing Nitrite in the partition process by using Diphenyl Thio Urea

    International Nuclear Information System (INIS)

    Mashudi; Busron-Masduki; Damunir; Mujianto

    1996-01-01

    The existence of nitrite in the process of U-Pu partition will disturb the partition process. In addition to the reoxidization of Pu 3+ to Pu 4+ , nitrite will also react with reductor. Both reactions are not expected, so that the nitrite ion in the partition process must be eliminated or reduced as much as possible. An experiment on the nitrite elimination in the partition process was done by reacting nitrite with diphenyl thio urea. The experiment result showed that the optimum condition was achieved at a contact time of 6 minutes, at the concentration of 0.004 N (300% stoichiometric), and the elimination result was 90%. This result is competitive enough if compared with hydrazine hydroxide or amido sulphonic acid, where the contact time is 6 minutes, the excess of both reactants are 200% and 300%, and the elimination results are 60% and 50% respectively

  20. Electronic properties of diphenyl-s-tetrazine and some related oligomers. An spectroscopic and theoretical study

    Science.gov (United States)

    Moral, Mónica; García, Gregorio; Peñas, Antonio; Garzón, Andrés; Granadino-Roldán, José M.; Melguizo, Manuel; Fernández-Gómez, Manuel

    2012-10-01

    This work presents a theoretical and spectroscopic study on the electronic and structural properties of the diphenyl-s-tetrazine molecule (Ph2Tz) and some oligomeric derivatives. Ph2Tz was synthesized through a variation of Pinner-type reaction which uses N-acetylcysteine as catalyst. Insight into the structure and electronic properties of the title compound was obtained through IR, Raman, UV-Vis spectra in different solvents, and theoretical calculations. Theoretical studies have been extended to different n-mers derivatives up to an ideal molecular wire through the oligomeric approximation, predicting this way electronic properties such as LUMO energy levels, electron affinity and reorganization energy in order to assess their possible applications in molecular electronics.

  1. trans-Carbonylchloridobis[diphenyl(4-vinylphenylphosphane-κP]rhodium(I

    Directory of Open Access Journals (Sweden)

    Reinout Meijboom

    2012-05-01

    Full Text Available In the title compound, trans-[RhCl(C20H17P2(CO], the RhI atom is situated on a center of symmetry, resulting in a statistical 1:1 disorder of the chloride [Rh—Cl = 2.383 (2 Å] and carbonyl [Rh—C = 1.752 (7 Å] ligands. The distorted trans square-planar environment is completed by two P atoms [Rh—P = 2.3251 (4 Å] from two diphenyl(4-vinylphenylphosphane ligands. The vinyl group is disordered over two sets of sites in a 0.668 (10:0.332 (10 ratio. The crystal packing exhibits weak C—H...Cl and C—H...O hydrogen bonds and π–π interactions between the phenyl rings of neighbouring molecules, with a centroid–centroid distance of 3.682 (2 Å.

  2. Temporal Trends of Hexabromocyclododecane, Polybrominated Diphenyl Ethers and Polychlorinated Biphenyls in Ringed Seals from East Greenland

    DEFF Research Database (Denmark)

    Vorkamp, Katrin; Riget, Frank Farsø; Bossi, Rossana

    2011-01-01

    also was found for adult seals with a time trend starting in 1994. ΣPCB decreased significantly in juvenile seals, again due to the 1986 value, while no trend was found for the adult animals. This indicates stagnating PCB concentrations at a relatively high level, in some cases possibly exceeding......Concentrations of hexabromocyclododecane (HBCD) were determined in a combination of archived and fresh blubber samples of juvenile ringed seals from East Greenland collected between 1986 and 2008. R-HBCD was the only diastereoisomer consistently above levels of quantification and showed...... on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) have been extended with new data for 2006 and 2008. ΣPBDE in juvenile seals was the only parameter with a slight upward trend, however, dependent on the low 1986 concentration. Removing this data point resulted in a downward trend, which...

  3. Polybrominated diphenyl ether exposure and reproductive hormones in North American men.

    Science.gov (United States)

    Makey, Colleen M; McClean, Michael D; Braverman, Lewis E; Pearce, Elizabeth N; Sjödin, Andreas; Weinberg, Janice; Webster, Thomas F

    2016-07-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals that are persistent organic pollutants. Animal experiments and some human studies indicate that PBDEs may adversely affect male reproductive function. To assess the association between PBDE exposure and reproductive hormones (RHs) in a North American male adult cohort. From 2010-11, we collected three serum samples from 27 healthy adult men. We assessed associations between PBDEs and RHs using mixed effect regression models. PBDEs were inversely associated with inhibin-B. In older men, increased concentrations of BDE-47 and BDE-100 were significantly associated with a decrease in inhibin-B, and an increase in follicular stimulating hormone (FSH). These findings suggest PBDE exposure may affect RHs in older men. We did not measure other parameters of male reproductive function and therefore these results are preliminary. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Polybrominated diphenyl ethers fate in China: a review with an emphasis on environmental contamination levels, human exposure and regulation.

    Science.gov (United States)

    Chen, Yuan; Li, Jinhui; Liu, Lili; Zhao, Nana

    2012-12-30

    Because of their highly effective flame-retardant capability, polybrominated diphenyl ethers (PBDEs) have been extensively used as flame retardants in consumer goods. However, compelling evidence shows that many congeners of PBDEs have been accumulating in the environment, in biota and in human populations worldwide. In China, although octabrominated diphenyl ether (octaBDE) has never been produced or used, pentabrominated diphenyl ether (pentaBDE) and decabrominated diphenyl ether (decaBDE) have been produced and used in large quantities. In the face of increasing evidence about PBDE pollution and the adoption of international conventions, there is a growing push for China to develop more stringent methods of managing PBDE waste. This paper summarizes the information about PBDE production and application, describes the flame-retarding mechanism, and then reviews the toxicity and levels of PBDEs in China's environmental media and human tissues. Based on international regulations on PBDEs, the paper finally puts forward some suggestions for Chinese policy making and for self-regulation within the flame retardant industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Improving Infant Exposure and Health Risk Estimates: Using Serum Data to Predict Polybrominated Diphenyl Ether Concentrations in Breast Milk

    Science.gov (United States)

    Women in the United States have breast milk concentrations of polybrominated diphenyl ethers (PBDEs) that are among the highest in the world, leading to concerns over the potential health implications to breastfeeding infants during critical stages of growth and development. Deve...

  6. Polybrominated diphenyl ethers in influents, suspended particulate matter, sediments, sewage treatment plant and effluents and biota from the Netherlands

    NARCIS (Netherlands)

    Boer, de J.; Wester, P.G.; Horst, van der A.; Leonards, P.E.G.

    2003-01-01

    Polybrominated diphenyl ethers (PBDEs) have been determined in 133 samples of suspended particulate matter (SPM), sediments, sewage treatment plant (STP) influents and effluents, fish and mussels from various locations in The Netherlands, as a part of a large Dutch national study on estrogenic

  7. The orientation-enhancing effect of diphenyl aluminium phosphate nanorods in a liquid-crystalline epoxy matrix ordered by magnetic field

    Czech Academy of Sciences Publication Activity Database

    Mossety-Leszczak, B.; Strachota, Beata; Strachota, Adam; Steinhart, Miloš; Šlouf, Miroslav

    2015-01-01

    Roč. 72, November (2015), s. 238-255 ISSN 0014-3057 Institutional support: RVO:61389013 Keywords : liquid-crystalline epoxy resins * magnetic field orientation * nanocomposites Subject RIV: CD - Macromolecular Chemistry Impact factor: 3.485, year: 2015

  8. Method of stripping plutonium from tributyl phosphate solution which contains dibutyl phosphate-plutonium stable complexes

    International Nuclear Information System (INIS)

    Ochsenfeld, W.; Schmieder, H.

    1976-01-01

    Fast breeder fuel elements which have been highly burnt-up are reprocessed by extracting uranium and plutonium into an organic solution containing tributyl phosphate. The tributyl phosphate degenerates at least partially into dibutyl phosphate and monobutyl phosphate, which form stable complexes with tetravalent plutonium in the organic solution. This tetravalent plutonium is released from its complexed state and stripped into aqueous phase by contacting the organic solution with an aqueous phase containing tetravalent uranium. 6 claims, 1 drawing figure

  9. Exposure to organophosphate flame retardants of hotel room attendants in Wuhan City, China.

    Science.gov (United States)

    Tao, Yun; Shang, Yinzhu; Li, Jing; Feng, Jingwen; He, Zhenyu; Covaci, Adrian; Wang, Peng; Luo, Jing; Mao, Xiang; Shi, Bin; Hu, Liqin; Luo, Dan; Mei, Surong

    2018-05-01

    Indoor environments provide sources of exposure to organophosphate flame retardants (PFRs), which are artificially synthesized fire-protecting agents used as additives in interior products. As public spaces, hotels are required to meet stricter fire-precaution criteria. As such, room attendants may be exposed to higher levels of PFRs. Our goal was to characterize the exposure of hotel room attendants to PFRs by measuring metabolites in their urine and the corresponding parent PFRs in dust and hand-wipes collected from 27 hotels located in Wuhan City, China. The exposure of the attendants was found to be omnipresent: urinary metabolites of PFRs, such as DPHP (diphenyl phosphate), BDCIPP (bis(1,3-dichloro-2-propyl) phosphate), and DoCP (di-o-cresyl phosphate) & DpCP (di-p-cresyl phosphate) were detected with high frequency (87%, 79% and 87%, respectively). We observed that metabolites in post-shift urine were consistently present at higher levels than those in the first morning voids (p  7 stories) had significantly higher BDCIPP and DPHP concentrations than those from low-rise buildings. A possible reason is that high-rise buildings may use high-grade fireproof building materials to meet stricter fire restrictions. Overall, these results indicate that PFRs exposure in hotels is a contributor to the personal exposure of hotel room attendants. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Dehalogenation of Polybrominated Diphenyl Ethers and Polychlorinated Biphenyl by Bimetallic, Impregnated, and Nanoscale Zerovalent Iron

    Science.gov (United States)

    Zhuang, Yuan; Ahn, Sungwoo; Seyfferth, Angelia L.; Masue-Slowey, Yoko; Fendorf, Scott; Luthy, Richard G.

    2011-01-01

    Nanoscale zerovalent iron particles (nZVI), bimetallic nanoparticles (nZVI/Pd), and nZVI/Pd impregnated activated carbon (nZVI/Pd-AC) composite particles were synthesized and investigated for their effectiveness to remove polybrominated diphenyl ethers (PBDEs) and/or polychlorinated biphenyls (PCBs). Palladization of nZVI promoted the dehalogenation kinetics for mono- to tri-BDEs and 2,3,4-trichlorobiphenyl (PCB 21). Compared to nZVI, the iron-normalized rate constants for nZVI/Pd were about 2-, 3-, and 4-orders of magnitude greater for tri-, di-, and mono-BDEs, respectively, with diphenyl ether as a main reaction product. The reaction kinetics and pathways suggest an H-atom transfer mechanism. The reaction pathways with nZVI/Pd favor preferential removal of para-halogens on PBDEs and PCBs. X-ray fluorescence mapping of nZVI/Pd-AC showed that Pd mainly deposits on the outer part of particles, while Fe was present throughout the activated carbon particles. While BDE 21 was sorbed onto activated carbon composites quickly, debromination was slower compared to reaction with freely dispersed nZVI/Pd. Our XPS and chemical data suggest about 7% of the total iron within the activated carbon was zero-valent, which shows the difficulty with in-situ synthesis of a significant fraction of zero-valent iron in the micro-porous material. Related factors that likely hinder the reaction with nZVI/Pd-AC are the heterogenous distribution of nZVI and Pd on activated carbon and/or immobilization of hydrophobic organic contaminants at the adsorption sites thereby inhibiting contact with nZVI. PMID:21557574

  11. Contamination of U.S. butter with polybrominated diphenyl ethers from wrapping paper.

    Science.gov (United States)

    Schecter, Arnold; Smith, Sarah; Colacino, Justin; Malik, Noor; Opel, Matthias; Paepke, Olaf; Birnbaum, Linda

    2011-02-01

    Our aim was to report the first known incidence of U.S. butter contamination with extremely high levels of polybrominated diphenyl ethers (PBDEs). Ten butter samples were individually analyzed for PBDEs. One of the samples and its paper wrapper contained very high levels of higher-brominated PBDEs. Dietary estimates were calculated using the 2007 U.S. Department of Agriculture Loss-Adjusted Food Availability data, excluding the elevated sample. The highly contaminated butter sample had a total upper bound PBDE level of 42,252 pg/g wet weight (ww). Levels of brominated diphenyl ether (BDE)-206, -207, and -209 were 2,000, 2,290, and 37,600 pg/g ww, respectively. Its wrapping paper contained a total upper-bound PBDE concentration of 804,751 pg/g ww, with levels of BDE-206, -207, and -209 of 51,000, 11,700, and 614,000 pg/g, respectively. Total PBDE levels in the remaining nine butter samples ranged from 180 to 1,212 pg/g, with geometric mean of 483 and median of 284 pg/g. Excluding the outlier, total PBDE daily intake from all food was 22,764 pg/day, lower than some previous U.S. dietary intake estimates. Higher-brominated PBDE congeners were likely transferred from contaminated wrapping paper to butter. A larger representative survey may help determine how frequently PBDE contamination occurs. Sampling at various stages in food production may identify contamination sources and reduce risk.

  12. Improved debromination of polybrominated diphenyl ethers by bimetallic iron–silver nanoparticles coupled with microwave energy

    International Nuclear Information System (INIS)

    Luo, Si; Yang, Shaogui; Sun, Cheng; Gu, Ji-Dong

    2012-01-01

    This study focused on the enhanced debromination of decabromodiphenyl ether (BDE-209) and 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) by Fe–Ag nano-particles under microwave radiation (Fe–Ag/MW). Fe–Ag bimetallic nano-particles were synthesized by reductive deposition of Ag on nano-iron and characterized with a number of techniques, including BET, XRD, TEM and XPS. Approximately 97% of BDE-209 or 78% of BDE-47 were rapidly transformed to its degradation products within 8 min in the Fe–Ag/MW system. The dehalogenation efficiency of polybrominated diphenyl ethers (PBDEs) was enhanced apparently by microwave radiation. Moreover, the microwave thermal energy played a significant role in accelerating the degradation reactions. Compared with nano-iron alone, the deposition of Ag also increased the rates of degradation. GC–MS and LC–MS/MS analyses of PBDEs' degradation products reveals that the possible degradation pathway proceeds through stepwise debromination from [n]-bromo- to [n-1]-bromo-DE, with bromine being substituted by hydrogen sequentially. Di- to nona-brominated congeners were formed during BDE-209 reduction, while diphenyl ether to tri-BDEs were observed during BDE-47 degradation. These results suggest that PBDEs can be debrominated rapidly by the innovative processes that may be environmentally friendly in applications. - Highlights: ► The Fe–Ag nanoparticles with a core–shell structure were successfully prepared. ► A highly efficient technology for debromination of PBDEs by Fe–Ag/MW was investigated. ► The effect of bromine's number on the stability against reduction of PBDEs was explored. ► The role of MW energy and Ag in the reactivity of the Fe–Ag/MW system was demonstrated. ► The possible degradation pathways of BDE-209 and BDE-47 were proposed.

  13. Global Gridded Emission Inventories of Pentabrominated Diphenyl Ether (PeBDE)

    Science.gov (United States)

    Li, Yi-Fan; Tian, Chongguo; Yang, Meng; Jia, Hongliang; Ma, Jianmin; Li, Dacheng

    2010-05-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardants widely used in many everyday products such as cars, furniture, textiles, and other electronic equipment. The commercial PBDEs have three major technical mixtures: penta-(PeBDE), octa-(OBDE) and decabromodiphenyl ethers (DeBDE). PeBDE is a mixture of several BDE congeners, such as BDE-47, -99, and -100, and has been included as a new member of persistent organic pollutants (POPs) under the 2009 Stockholm Convention. In order to produce gridded emission inventories of PeBDE on a global scale, information of production, consumption, emission, and physiochemical properties of PeBDE have been searched for published papers, government reports, and internet publications. A methodology to estimate the emissions of PeBDE has been developed and global gridded emission inventories of 2 major congener in PeBDE mixture, BDE-47 and -99, on a 1 degree by 1degree latitude/longitude resolution for 2005 have been compiled. Using these emission inventories as input data, the Canadian Model for Environmental Transport of Organochlorine Pesticides (CanMETOP) model was used to simulate the transport of these chemicals and their concentrations in air were calculated for the year of 2005. The modeled air concentration of BDE-47 and -99 were compared with the monitoring air concentrations of these two congeners in the same year obtained from renowned international/national monitoring programs, such as Global Atmospheric Passive Sampling (GAPS), the Integrated Atmospheric Deposition Network (IADN), and the Chinese POPs Soil and Air Monitoring Program (SAMP), and significant correlations between the modeled results and the monitoring data were found, indicating the high quality of the produced emission inventories of BDE-47 and -99. Keywords: Pentabrominated Diphenyl Ether (PeBDE), Emission Inventories, Global, Model

  14. Improved debromination of polybrominated diphenyl ethers by bimetallic iron-silver nanoparticles coupled with microwave energy

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Si [College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Yang, Shaogui, E-mail: yangdlut@126.com [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Sun, Cheng, E-mail: envidean@nju.edu.cn [State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093 (China); Gu, Ji-Dong [College of Resources and Environment, Hunan Agricultural University, Changsha 410128 (China); Laboratory of Environmental Microbiology and Toxicology, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong (China)

    2012-07-01

    This study focused on the enhanced debromination of decabromodiphenyl ether (BDE-209) and 2,2 Prime ,4,4 Prime -tetrabromodiphenyl ether (BDE-47) by Fe-Ag nano-particles under microwave radiation (Fe-Ag/MW). Fe-Ag bimetallic nano-particles were synthesized by reductive deposition of Ag on nano-iron and characterized with a number of techniques, including BET, XRD, TEM and XPS. Approximately 97% of BDE-209 or 78% of BDE-47 were rapidly transformed to its degradation products within 8 min in the Fe-Ag/MW system. The dehalogenation efficiency of polybrominated diphenyl ethers (PBDEs) was enhanced apparently by microwave radiation. Moreover, the microwave thermal energy played a significant role in accelerating the degradation reactions. Compared with nano-iron alone, the deposition of Ag also increased the rates of degradation. GC-MS and LC-MS/MS analyses of PBDEs' degradation products reveals that the possible degradation pathway proceeds through stepwise debromination from [n]-bromo- to [n-1]-bromo-DE, with bromine being substituted by hydrogen sequentially. Di- to nona-brominated congeners were formed during BDE-209 reduction, while diphenyl ether to tri-BDEs were observed during BDE-47 degradation. These results suggest that PBDEs can be debrominated rapidly by the innovative processes that may be environmentally friendly in applications. - Highlights: Black-Right-Pointing-Pointer The Fe-Ag nanoparticles with a core-shell structure were successfully prepared. Black-Right-Pointing-Pointer A highly efficient technology for debromination of PBDEs by Fe-Ag/MW was investigated. Black-Right-Pointing-Pointer The effect of bromine's number on the stability against reduction of PBDEs was explored. Black-Right-Pointing-Pointer The role of MW energy and Ag in the reactivity of the Fe-Ag/MW system was demonstrated. Black-Right-Pointing-Pointer The possible degradation pathways of BDE-209 and BDE-47 were proposed.

  15. Global assessment of polybrominated diphenyl ethers in farmed and wild salmom

    Energy Technology Data Exchange (ETDEWEB)

    Hites, R. [Indiana Univ., Bloomington, IN (United States); Foran, J. [Midwest Center for Environmental Science, Milwaukee, WI (United States); Schwager, S.; Knuth, B. [Cornell Univ., Ithaca, NY (United States); Hamilton, C. [AXYS Analytical, Sydney (Australia); Carpenter, D. [Albany Univ., NY (United States)

    2004-09-15

    Despite their societal benefits, polybrominated diphenyl ethers (PBDEs) seem to be migrating from the products in which they are used and entering the environment and people. PBDEs are now ubiquitous; they can be found in air, water, fish, birds, marine mammals, and people, and in most cases, the concentrations of these compounds have increased dramatically over the last 20 years. One source of PBDEs in people is their food supply, and an increasingly important food is salmon, which is nutritious and high in beneficial fats. Between 1987 and 1999, salmon consumption increased annually at a rate of 10-20%. Currently, over half the salmon sold globally is farm-raised in Northern Europe, Chile, Canada, and the United States, and the annual global production of farmed salmon (predominantly Atlantic salmon) has risen from {proportional_to}27,000 to over 1 million metric tons during the past two decades. The health benefits of eating fish such as salmon have been well documented. However, salmon are relatively fatty, carnivorous fish that feed high in the food web, and as such, they bioaccumulate contaminants. In a previous study, we reported that levels of persistent, bioaccumulative contaminants (such as PCBs, dioxins, and several chlorinated pesticides) are significantly higher in farm-raised salmon than in wild salmon and that salmon raised on European farms have significantly greater toxic contaminant loads than those raised on North and South American farms. In this report, we provide results on polybrominated diphenyl ether concentrations in salmon purchased from farms in eight major salmon farming regions, in five species of wild Pacific salmon, and in salmon fillets purchased at supermarkets in North America and Europe.

  16. Novel routes in flame retardancy of bisphenol A polycarbonate/impact modifier/aryl phosphate blends

    Energy Technology Data Exchange (ETDEWEB)

    Wawrzyn, Eliza

    2013-07-01

    The massive use of electronic engineering products accompanied by high demands on fire safety has led to increasing interest in environmentally friendly flame retardancy of bisphenol A polycarbonate (PC) based materials. In this work, novel routes for enhancing the flame retardancy of PC/Impact Modifier/Aryl phosphate were studied with respect to pyrolysis (TG, TG-FTIR, ATR-FTIR, NMR), flammability (LOI and UL 94) and fire behavior (cone calorimeter at different irradiations). To improve charring of PC/ABS{sub PTFE}+Aryl phosphate, the exchange of bisphenol A bis(diphenyl phosphate) (BDP) with novel aryl phosphates was proposed. Two novel flame retardants were synthesized: 3,3,5-trimethylcyclohexylbisphenol-bis(diphenyl phosphate) (TMC-BDP) and bisphenol A-bis(diethylphosphate) (BEP). TMC-BDP was more stable than BDP, thus gave a potential to increase the chemical reactions between the components of the PC/ABS{sub PTFE}+Aryl phosphate, whereas more reactive BEP was expected to increase the cross linking activity with the polymer matrix. Nevertheless, the corresponding blends did not enhance the flame retardancy compared to PC/ABS{sub PTFE}+BDP. BEP in PC/ABS{sub PTFE} preferred to cross-link with itself instead of with PC, thus it showed poor fire protection performance. TMC-BDP gave as good results as BDP in PC/ABS PTFE material. The results delivered evidence that BDP possesses a high degree of optimization in PC/ABS{sub PTFE} system. To provide a novel impact modifier improving not only mechanical properties but also the fire retardancy of PC/BDP material, the replacement of highly flammable acrylonitrile-butadiene-styrene (ABS) with silicon acrylate rubber (SiR) with high content of polydimethylsiloxane (PDMS) was studied. In PC/SiR{sub PTFE}/BDP the replacement of ABS is beneficial, but PDMS worsened the BDP gas phase and condensed phase action. PDMS reacted also with PC during combustion. PDMS-PC and PDMS-BDP interactions led to silicon dioxide. In fact, the

  17. Bio-treatment of phosphate from synthetic wastewater using ...

    African Journals Online (AJOL)

    In this study, the efficient phosphate utilizing isolates were used to remove phosphate from synthetic phosphate wastewater was tested using batch scale process. Hence the objective of the present study was to examine the efficiency of bacterial species individually for the removal of phosphate from synthetic phosphate ...

  18. In vivo treatment with diphenyl ditelluride induces neurodegeneration in striatum of young rats: Implications of MAPK and Akt pathways

    Energy Technology Data Exchange (ETDEWEB)

    Heimfarth, Luana; Loureiro, Samanta Oliveira; Dutra, Márcio Ferreira; Andrade, Cláudia; Pettenuzzo, Letícia; Guma, Fátima T. Costa Rodrigues; Gonçalves, Carlos Alberto Saraiva [Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre, RS (Brazil); Batista Teixeira da Rocha, João [Departamento de Química, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, RS Brazil (Brazil); Pessoa-Pureur, Regina, E-mail: rpureur@ufrgs.br [Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre, RS (Brazil)

    2012-10-15

    In the present report 15 day-old Wistar rats were injected with 0.3 μmol of diphenyl ditelluride (PhTe){sub 2}/kg body weight and parameters of neurodegeneration were analyzed in slices from striatum 6 days afterwards. We found hyperphosphorylation of intermediate filament (IF) proteins from astrocyte (glial fibrillary acidic protein—GFAP and vimentin) and from neuron (low-, medium- and high molecular weight neurofilament subunits: NF-L, NF-M and NF-H, respectively) and increased MAPK (Erk, JNK and p38MAPK) as well as PKA activities. The treatment induced reactive astrogliosis in the striatum, evidenced by increased GFAP and vimentin immunocontent as well as their mRNA overexpression. Also, (PhTe){sub 2} significantly increased the propidium iodide (PI) positive cells in NeuN positive population without altering PI incorporation into GFAP positive cells, indicating that in vivo exposure to (PhTe){sub 2} provoked neuronal damage. Immunohistochemistry showed a dramatic increase of GFAP staining characteristic of reactive astrogliosis. Moreover, increased caspase 3 in (PhTe){sub 2} treated striatal slices suggested apoptotic cell death. (PhTe){sub 2} exposure decreased Akt immunoreactivity, however phospho-GSK-3-β (Ser9) was unaltered, suggesting that this kinase is not directly implicated in the neurotoxicity of this compound. Therefore, the present results shed light into the mechanisms of (PhTe){sub 2}-induced neurodegeneration in rat striatum, evidencing a critical role for the MAPK and Akt signaling pathways and disruption of cytoskeletal homeostasis, which could be related with apoptotic neuronal death and astrogliosis. -- Highlights: ► Diphenyl ditelluride causes apoptotic neuronal death in the striatum of young rats. ► Diphenyl ditelluride causes reactive astrogliosis in the striatum of rats. ► Diphenyl ditelluride disrupts the homeostasis of the cytoskeleton of the striatum. ► The actions of diphenyl ditelluride are mediated by MAPK and Akt

  19. Pentose phosphates in nucleoside interconversion and catabolism.

    Science.gov (United States)

    Tozzi, Maria G; Camici, Marcella; Mascia, Laura; Sgarrella, Francesco; Ipata, Piero L

    2006-03-01

    Ribose phosphates are either synthesized through the oxidative branch of the pentose phosphate pathway, or are supplied by nucleoside phosphorylases. The two main pentose phosphates, ribose-5-phosphate and ribose-1-phosphate, are readily interconverted by the action of phosphopentomutase. Ribose-5-phosphate is the direct precursor of 5-phosphoribosyl-1-pyrophosphate, for both de novo and 'salvage' synthesis of nucleotides. Phosphorolysis of deoxyribonucleosides is the main source of deoxyribose phosphates, which are interconvertible, through the action of phosphopentomutase. The pentose moiety of all nucleosides can serve as a carbon and energy source. During the past decade, extensive advances have been made in elucidating the pathways by which the pentose phosphates, arising from nucleoside phosphorolysis, are either recycled, without opening of their furanosidic ring, or catabolized as a carbon and energy source. We review herein the experimental knowledge on the molecular mechanisms by which (a) ribose-1-phosphate, produced by purine nucleoside phosphorylase acting catabolically, is either anabolized for pyrimidine salvage and 5-fluorouracil activation, with uridine phosphorylase acting anabolically, or recycled for nucleoside and base interconversion; (b) the nucleosides can be regarded, both in bacteria and in eukaryotic cells, as carriers of sugars, that are made available though the action of nucleoside phosphorylases. In bacteria, catabolism of nucleosides, when suitable carbon and energy sources are not available, is accomplished by a battery of nucleoside transporters and of inducible catabolic enzymes for purine and pyrimidine nucleosides and for pentose phosphates. In eukaryotic cells, the modulation of pentose phosphate production by nucleoside catabolism seems to be affected by developmental and physiological factors on enzyme levels.

  20. Hydroformylation of propene and 1-hexene catalysed by a alpha-zirconium phosphate supported rhodium-phosphine complex

    DEFF Research Database (Denmark)

    Karlsson, Magnus; Andersson, C; Hjortkjær, Jes

    2001-01-01

    The reaction of the amphiphilic ligand {4-[bis(diethylaminoethyl)aminomethyl]diphenyl}phosphine with alpha -zirconium phosphate, of intermediate surface area (24m(2) g(-1)), provided a phosphine functionalised support in which electrostatic interaction between ammonium groups on the ligand and de......-protonated surface hydroxyl groups on the support provided the binding force. The X-ray powder diffractogram of the material showed that the binding lowers the crystallinity of the carrier and that the ligand is not intercalated but bound at the outer surface and at the entrances to the interlamellar space. Reaction...... of the phosphine functionalised support with Rh(CO)(2)(acac) led to CO-phosphine exchange and formation of an immobilised complex of the composition LRh(CO)(acac) (L = surface bound phosphine). When applied as catalyst in continuous gas-phase hydroformylation of propene and in liquid phase hydroformylation of 1...

  1. Removal of phosphate from solution by adsorption and precipitation of calcium phosphate onto monohydrocalcite.

    Science.gov (United States)

    Yagi, Shintaro; Fukushi, Keisuke

    2012-10-15

    The sorption behavior and mechanism of phosphate on monohydrocalcite (CaCO(3)·H(2)O: MHC) were examined using batch sorption experiments as a function of phosphate concentrations, ionic strengths, temperatures, and reaction times. The mode of PO(4) sorption is divisible into three processes depending on the phosphate loading. At low phosphate concentrations, phosphate is removed by coprecipitation of phosphate during the transformation of MHC to calcite. The sorption mode at the low-to-moderate phosphate concentrations is most likely an adsorption process because the sorption isotherm at the conditions can be fitted reasonably with the Langmuir equation. The rapid sorption kinetics at the conditions is also consistent with the adsorption reaction. The adsorption of phosphate on MHC depends strongly on ionic strength, but slightly on temperature. The maximum adsorption capacities of MHC obtained from the regression of the experimental data to the Langmuir equation are higher than those reported for stable calcium carbonate (calcite or aragonite) in any conditions. At high phosphate concentrations, the amount of sorption deviates from the Langmuir isotherm, which can fit the low-to-moderate phosphate concentrations. Speciation-saturation analyses of the reacted solutions at the conditions indicated that the solution compositions which deviate from the Langmuir equation are supersaturated with respect to a certain calcium phosphate. The obtained calcium phosphate is most likely amorphous calcium phosphate (Ca(3)(PO(4))(2)·xH(2)O). The formation of the calcium phosphate depends strongly on ionic strength, temperature, and reaction times. The solubility of MHC is higher than calcite and aragonite because of its metastability. Therefore, the higher solubility of MHC facilitates the formation of the calcium phosphates more than with calcite and aragonite. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Cyanotoxins: a poison that frees phosphate.

    Science.gov (United States)

    Raven, John A

    2010-10-12

    Autotrophic organisms obtain phosphorus from the environment by secreting alkaline phosphatases that act on esters, resulting in inorganic phosphate that is then taken up. New work shows that the cyanobacterium Aphanizomenon ovalisporum obtains inorganic phosphate by secreting the cyanotoxin cylindrospermopsin, which induces alkaline phosphatase in other phytoplankton species. Copyright © 2010 Elsevier Ltd. All rights reserved.

  3. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

    Schipper, W.J.; Klapwijk, A.; Potjer, A.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

    2001-01-01

    The feasibility of phosphate recycling in the white phosphorus production process is discussed. Several types of materials may be recycled, provided they are dry inorganic materials, low in iron, copper and zinc. Sewage sludge ash may be used if no iron is used for phosphate precipitation in the

  4. Photoelectron spectroscopy of phosphites and phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Chattopadhyay, S.; Findley, G.L.; McGlynn, S.P.

    1981-01-01

    The ultraviolet photoelectron spectra (UPS) of trimethyl and triethyl phosphite, trimethyl and triethyl phosphate and four substituted phosphates are presented. Assignments are based on analogies to the UPS of phosphorus trichloride and phosphoryl trichloride and are substantiated by CNDO/2 computations. The mechanisms of P-O (axial) bond formation is discussed.

  5. Phosphate recycling in the phosphorus industry

    NARCIS (Netherlands)

    Schipper, W.J.; Klapwijk, A.; Potjer, B.; Rulkens, W.H.; Temmink, B.G.; Kiestra, F.D.G.; Lijmbach, A.C.M.

    2004-01-01

    The article describes the potential and limitations for recovery of phosphate from secondary materials in the production process for white phosphorus. This thermal process involves the feeding of phosphate rock, cokes and pebbles to a furnace. The reducing conditions in the furnace promote the

  6. Rock phosphate solubilization by the ectomycorrhizal fungus ...

    African Journals Online (AJOL)

    SAM

    2014-06-18

    Jun 18, 2014 ... To evaluate phosphate solubilization of ... and MHB had the potential to solubilize these phosphates by decreasing the pH and confirmed that ... Minerals like N, P, K, Ca, S, Zn, Cu and Sr are ... sterile distilled water, chopped, homogenized in 10 ml sterile .... The role of carbon source is important in mineral.

  7. Genetics Home Reference: glucose phosphate isomerase deficiency

    Science.gov (United States)

    ... glycolytic pathway; in this step, a molecule called glucose-6-phosphate is converted to another molecule called fructose-6-phosphate. When GPI remains a single molecule (a monomer) it is involved in the development and maintenance of nerve cells ( neurons ). In this context, it is often known as ...

  8. Mineral phosphate solubilizing bacterial community in agro-ecosystem

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... patterns. Four insoluble phosphate sources; purulia rock phosphate (PRP), mussourie rock phosphate. (MRP) ... community composition analysis (Garland, 1996a) and ..... the threshold level that enabled only a few species to.

  9. Sonochemical precipitation of amorphous uranium phosphates from trialkyl phosphate solutions and their thermal conversion to UP2O7

    Czech Academy of Sciences Publication Activity Database

    Doroshenko, I.; Žurková, J.; Moravec, Z.; Bezdička, Petr; Pinkas, J.

    2015-01-01

    Roč. 26, SEP (2015), s. 157-162 ISSN 1350-4177 Institutional support: RVO:61388980 Keywords : Uranium * Phosphates * Sonochemistry * Nuclear waste * Trimethyl phosphate * Triethyl phosphate Subject RIV: CA - Inorganic Chemistry Impact factor: 4.556, year: 2015

  10. Polybrominated Diphenyl Ether Exposure and Thyroid Function Tests in North American Adults.

    Science.gov (United States)

    Makey, Colleen M; McClean, Michael D; Braverman, Lewis E; Pearce, Elizabeth N; He, Xue-Mei; Sjödin, Andreas; Weinberg, Janice M; Webster, Thomas F

    2016-04-01

    Polybrominated diphenyl ethers (PBDEs) are flame-retardant chemicals that are added to many consumer products. Multiple animal studies have shown PBDEs to be thyroid hormone (TH) disruptors. Epidemiologic evidence of PBDE exposure associated with TH disruption has been inconclusive. We used repeated measures to estimate associations between serum PBDE concentrations and THs in a North American adult cohort. From 2010 to 2011, we collected ≤ 3 serum samples at approximately 6-month intervals from 52 healthy adult office workers from Boston, Massachusetts, for analysis of PBDE congeners and THs. The geometric mean sum concentrations of the most prevalent PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, and BDE-153) were 22 ng/g lipid in winter 2010, 23 ng/g lipid in summer 2010, and 19 ng/g lipid in winter 2011. BDE-47 was the predominant congener. Based on a multivariable mixed regression model, we estimated that on average, a 1-ng/g serum increase in BDE-47 was associated with a 2.6-μg/dL decrease in total thyroxine (T4) (95% CI: -4.7, -0.35). Total T4 was inversely associated with each PBDE congener. Serum concentrations of PBDEs were not strongly associated with total triiodothyronine (T3), free T4, or thyroid-stimulating hormone (TSH). These results are consistent with those from animal studies showing that exposure to PBDEs is associated with a decrease in serum T4. Because the other TH concentrations did not appear to be associated with BDE exposures, our findings do not indicate effects on the pituitary-thyroid axis. Taken together, our findings suggest that PBDE exposure might decrease the binding of T4 to serum T4 binding proteins. Makey CM, McClean MD, Braverman LE, Pearce EN, He XM, Sjödin A, Weinberg JM, Webster TF. 2016. Polybrominated diphenyl ether exposure and thyroid function tests in North American adults. Environ Health Perspect 124:420-425; http://dx.doi.org/10.1289/ehp.1509755.

  11. Are Polyphosphates or Phosphate Esters Prebiotic Reagents?

    Science.gov (United States)

    Keefe, Anthony D.; Miller, Stanley L.

    1995-01-01

    It is widely held that there was a phosphate compound in prebiotic chemistry that played the role of adenosine triphosphate and that the first living organisms had ribose-phosphate in the backbone of their genetic material. However, there are no known efficient prebiotic synthesis of high-energy phosphates or phosphate esters. We review the occurrence of phosphates in nature, the efficiency of the volcanic synthesis of P4O10, the efficiency of polyphosphate synthesis by heating phosphate minerals under geological conditions, and the use of high-energy organic compounds such as cyanamide or hydrogen cyanide. These are shown to be inefficient processes especially when the hydrolysis of the polyphosphates is taken into account. For example, if a whole atmosphere of methane or carbon monoxide were converted to cyanide which somehow synthesized polyphosphates quantitatively, the polyphosphate concentration in the ocean would still have been insignificant. We also attempted to find more efficient high-energy polymerizing agents by spark discharge syntheses, but without success. There may still be undiscovered robust prebiotic syntheses of polyphosphates, or mechanisms for concentrating them, but we conclude that phosphate esters may not have been constituents of the first genetic material. Phosphoanhydrides are also unlikely as prebiotic energy sources.

  12. How do arbuscular mycorrhizal fungi handle phosphate? New insight into fine-tuning of phosphate metabolism.

    Science.gov (United States)

    Ezawa, Tatsuhiro; Saito, Katsuharu

    2018-04-27

    Contents Summary I. Introduction II. Foraging for phosphate III. Fine-tuning of phosphate homeostasis IV. The frontiers: phosphate translocation and export V. Conclusions and outlook Acknowledgements References SUMMARY: Arbuscular mycorrhizal fungi form symbiotic associations with most land plants and deliver mineral nutrients, in particular phosphate, to the host. Therefore, understanding the mechanisms of phosphate acquisition and delivery in the fungi is critical for full appreciation of the mutualism in this association. Here, we provide updates on physical, chemical, and biological strategies of the fungi for phosphate acquisition, including interactions with phosphate-solubilizing bacteria, and those on the regulatory mechanisms of phosphate homeostasis based on resurveys of published genome sequences and a transcriptome with reference to the latest findings in a model fungus. For the mechanisms underlying phosphate translocation and export to the host, which are major research frontiers in this field, not only recent advances but also testable hypotheses are proposed. Lastly, we briefly discuss applicability of the latest tools to gene silencing in the fungi, which will be breakthrough techniques for comprehensive understanding of the molecular basis of fungal phosphate metabolism. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

  13. Titrimetric determination of uranium in tributyl phosphate

    International Nuclear Information System (INIS)

    Sobkowska, A.

    1978-01-01

    The titrimetric method involving the reduction of U(VI) to uranium(IV) by iron(II) in phosphoric acid, selective oxidation of the excess of iron(II) and potentiometric titration with dichromate was directly used for the determination of uranium in tributyl phosphate mixtures. The procedure was applied to solutions containing more than 2 mg of uranium in the sample but the highest precision and accuracy were obtained in the range from 20 to 200 mg of uranium. Dibutyl phosphate and monobutyl phosphate as well as the other radiolysis products of TBP had no influence on the results of determinations. (author)

  14. Uranium and heavy metals in phosphate fertilizers

    International Nuclear Information System (INIS)

    Khater, A.E.M.

    2008-01-01

    Agricultural applications of chemical fertilizers are a worldwide practice. The specific activity of uranium-238 and heavy metals in phosphate fertilizers depends on the phosphate ore from which the fertilizer produced and on the chemical processing of the ore. Composite phosphate fertilizers samples where collected and the uranium-238 specific activity, in Bq/kg, and As, Cd, Cu, Pb, Se concentration, in ppm, were measured. The annual addition of these elements in soil due to fertilization were calculated and discussed. (author)(tk)

  15. Global radiological impact of the phosphate fertilizers

    International Nuclear Information System (INIS)

    Morales, Rudnei Karam; Alves, Rex Nazare

    1996-01-01

    About ninety percent of the products obtained in the phosphate industry are directly used in agriculture as fertilizers. The uranium, thorium and radium content in phosphate fertilizers pollute the soil, water and air, creating risks due to associated natural radiation. This work shows the concentration of radionuclides present in various products of the national and American phosphate fertilizers industry, and compared them with worldwide mean values. The radiological impact of the products on the environment is evaluated and suggestions are presented in order to minimize the risks due to radioactivity. (author)

  16. Measurement of the specific heats of Santowax 'R', para-, meta- and ortho-terphenyl, diphenyl and dowtherm 'A'

    International Nuclear Information System (INIS)

    Bowring, R.W.; Garton, D.A.; Norris, H.F.

    1960-12-01

    New absolute measurements have been made of the specific heats of Santowax 'R1, the terphenyl isomers, diphenyl and Dowtherm 'A'. An adiabatic calorimeter was used in which the sample was heated electrically while a surrounding jacket was maintained at the same temperature as the calorimeter. The specific heats of all materials tested were found to increase linearly with temperature, the slope being substantially the same for all the pure materials except para-terphenyl. The specific heat of Santowax 'R' was about 1/2% less than the weighted mean of its components. The probable accuracy of the measurements was ± 2% and this was confirmed by comparison with diphenyl ether. A summary of results is given in Table 1 and Figure 10. (author)

  17. Dipropyl 3,6-diphenyl-1,2-dihydro-1,2,4,5-tetrazine-1,2-dicarboxylate.

    Science.gov (United States)

    Rao, Guo-Wu; Hu, Wei-Xiao

    2003-05-01

    The title compound, C(22)H(24)N(4)O(4), was prepared from propyl chloroformate and 3,6-diphenyl-1,2-dihydro-s-tetrazine. This reaction yields the title compound rather than dipropyl 3,6-diphenyl-1,4-dihydro-s-tetrazine-1,4-dicarboxylate. The 2,3-diazabutadiene group in the central six-membered ring is not planar; the C=N double-bond length is 1.285 (2) A, and the average N-N single-bond length is 1.401 (3) A, indicating a lack of conjugation. The ring has a twist conformation, in which adjacent N atoms lie +/- 0.3268 (17) A from the plane of the ring. The molecule has twofold crystallographic symmetry.

  18. Levels and distribution of polybrominated diphenyl ethers in Three Gorges Reservoir, China

    Directory of Open Access Journals (Sweden)

    Jingxian Wang

    2017-03-01

    Full Text Available Polybrominated diphenyl ethers (PBDEs were investigated in water, sediments, suspended sediments and biofilms in Three Gorges Reservoir (TGR, China. Results showed that dissolved bioavailable PBDEs in water of TGR collected with semipermeable membrane device (SPMD-based virtual organisms (VOs were very low in the range of n.d. to 811 pg/g lipid and the detected compounds were mainly low molecular BDEs such as BDE-15, 17, 28, 47, 49, 66, 99 and 100. The PBDE levels in the sediment core collected near the dam were also very low in the range of 84–300 pg/g dw and the detected compounds were mainly large molecular BDEs such as BDE-196, 197, 206, 207 and 208. In suspended sediments and biofilms, the levels of PBDEs ranged from 298 to 52,843 pg/g dw and the detected compounds were also mainly large molecular BDEs such as BDE- 196, 197, 201, 203, 206, 207, 208 and 209. The dominant compound was BDE-209 which accounted for more than 90% of the total BDEs. Therefore, large molecular BDEs tended to be attached on fine particles. The vertical profile of BDEs on suspended sediments (SS showed that SSs in the middle depth of water contained high level of BDE-209. The phenomenon indicated that most of BDE-209 did not settle into the sediment in front of the dam, instead transported further to downstream.

  19. Electronic properties of diphenyl-s-tetrazine and some related oligomers. An spectroscopic and theoretical study

    Energy Technology Data Exchange (ETDEWEB)

    Moral, Monica; Garcia, Gregorio [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Penas, Antonio [Departamento de Quimica Inorganica y Organica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Garzon, Andres; Granadino-Roldan, Jose M. [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Melguizo, Manuel [Departamento de Quimica Inorganica y Organica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain); Fernandez-Gomez, Manuel, E-mail: mfg@ujaen.es [Departamento de Quimica Fisica y Analitica, Facultad de Ciencias Experimentales, Universidad de Jaen, Campus las Lagunillas, E23071 Jaen (Spain)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer We study properties of Ph{sub 2}Tz and (PhTz){sub n}Ph as candidates for organic electronics. Black-Right-Pointing-Pointer The synthesis of Ph{sub 2}Tz was performed through a modified Pinner-type reaction. Black-Right-Pointing-Pointer IR/Raman spectra allowed to conclude that Ph{sub 2}Tz is nearly planar in liquid phase. Black-Right-Pointing-Pointer Electronic structure was studied by UV-Vis/TD-DFT methods in different solvents. Black-Right-Pointing-Pointer Bandgap, E{sub LUMO}, electron mobility predict some n-type character for limit polymer. -- Abstract: This work presents a theoretical and spectroscopic study on the electronic and structural properties of the diphenyl-s-tetrazine molecule (Ph{sub 2}Tz) and some oligomeric derivatives. Ph{sub 2}Tz was synthesized through a variation of Pinner-type reaction which uses N-acetylcysteine as catalyst. Insight into the structure and electronic properties of the title compound was obtained through IR, Raman, UV-Vis spectra in different solvents, and theoretical calculations. Theoretical studies have been extended to different n-mers derivatives up to an ideal molecular wire through the oligomeric approximation, predicting this way electronic properties such as LUMO energy levels, electron affinity and reorganization energy in order to assess their possible applications in molecular electronics.

  20. Complexity of Naturally Produced Polybrominated Diphenyl Ethers Revealed via Mass Spectrometry

    Science.gov (United States)

    Agarwal, Vinayak; Li, Jie; Rahman, Imran; Borgen, Miles; Aluwihare, Lihini I.; Biggs, Jason S.; Paul, Valerie J.; Moore, Bradley S.

    2015-01-01

    Polybrominated diphenyl ethers (PBDEs) are persistent and bioaccumulative anthropogenic and natural chemicals that are broadly distributed in the marine environment. PBDEs are potentially toxic due to inhibition of various mammalian signaling pathways and enzymatic reactions. PBDE isoforms vary in toxicity in accordance with structural differences, primarily in the number and pattern of hydroxyl moieties afforded upon a conserved core structure. Over four decades of isolation and discovery-based efforts have established an impressive repertoire of natural PBDEs. Based on our recent reports describing the bacterial biosyntheses of PBDEs, we predicted the presence of additional classes of PBDEs to those previously identified from marine sources. Using mass spectrometry and NMR spectroscopy, we now establish the existence of new structural classes of PBDEs in marine sponges. Our findings expand the chemical space explored by naturally produced PBDEs, which may inform future environmental toxicology studies. Furthermore, we provide evidence for iodinated PBDEs and direct attention toward the contribution of promiscuous halogenating enzymes in further expanding the diversity of these polyhalogenated marine natural products. PMID:25559102

  1. Spatial distributions and temporal trends in polybrominated diphenyl ethers in Detroit River suspended sediments.

    Science.gov (United States)

    Marvin, Chris; Waltho, Jasmine; Jia, Julia; Burniston, Debbie

    2013-05-01

    Suspended sediments from the Detroit River were collected using sediment traps at sites ranging from western Lake Erie to southern Lake St. Clair to assess spatial distributions and temporal trends of polybrominated diphenyl ethers (PBDEs). The distribution of PBDEs in suspended sediments in the Detroit River appeared influenced by shoreline-based contemporary urban and industrial activities, which stood in contrast to PCBs that were associated with areas of historic industrial activity. Temporal trend data indicate that total PBDE concentrations decreased in the period after 2000 in response to cessation of production of the penta- and octa BDE formulations. Concentrations of total PBDEs ranged from roughly 7 ng g(-1) (4 ng g(-1) BDE 209) in southern Lake St. Clair to several hundred ng g(-1) (60-180 ng g(-1) BDE 209) in the lower reaches of the Detroit River. The widespread occurrence of PBDEs in Detroit River suspended sediments suggests that large urban areas can act as diffuse sources of these chemicals that are used in modern industrial applications and consumer products. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  2. Polybrominated diphenyl ethers: a case study for using biomonitoring data to address risk assessment questions.

    Science.gov (United States)

    Birnbaum, Linda S; Cohen Hubal, Elaine A

    2006-11-01

    The use of biomonitoring data holds promise for characterizing exposure and informing risk assessment. Biomonitoring data have been used successfully to track population trends, identify susceptible populations, and provide indications of emerging environmental health issues. However, there remain challenges associated with interpreting biomonitoring data for risk assessment. An international biomonitoring workshop was convened in September 2004 to explore the use of biomonitoring data in the context of risk assessment. Six compounds were examined as case studies for this workshop, including polybrominated diphenyl ethers (PBDEs). The PBDE case study was developed to provide an example of a persistent compound for which relatively few data are available for human exposure, biomonitoring, and health outcomes. PBDEs are used in hard plastics, electronics, textiles, and polyurethane foam products. The congener pattern downstream of production facilities often resembles the commercial mixture. However, because these compounds persist in the environment and in biota, the patterns of congeners evolve. PBDEs partition into body lipids, and direct measurement of bromodiphenyl ether congeners in biologic specimens provides a good marker of exposure. Data indicate significant variability (> 100-fold range) in lipid-adjusted levels for PBDEs in the general population. It is hypothesized that both exposure and pharmacokinetics may play a role in observed congener profiles. Significant gaps in our ability to interpret PBDE biomonitoring data to address public health and risk assessment questions include limited knowledge of environmental fate and transport of PBDE congeners, limited population-based data for adults, and lack of data for potentially vulnerable populations such as children.

  3. Riverine inputs of polybrominated diphenyl ethers from the Pearl River Delta (China) to the coastal ocean.

    Science.gov (United States)

    Guan, Yu-Feng; Wang, Ji-Zhong; Ni, Hong-Gang; Luo, Xiao-Jun; Mai, Bi-Xian; Zeng, Eddy Y

    2007-09-01

    Riverine runoff is an important mode to transport anthropogenic pollutants from terrestrial sources to oceans. Polybrominated diphenyl ethers (PBDEs) were measured in riverine runoff samples from the eight major outlets within the Pearl River Delta (PRD), China, an economically fast developing region housing a vast number of electronics manufacturing and assembling plants. The sigma 17PBDEs (sum of 17 BDE congeners, i.e., BDE-28, -47, -66, -85, -99, -100, -138, -153, -154, -183, -196, -197, -203, -206, -207, -208, and -209) concentrations varied from 344 to 68,000 pg/L, with those of BDE-209, BDE-47, and BDE-99 being 335-65200, 3-143, and production of brominated fire retardants (approximately 10000 metric tons/year) and the annual riverine input of total PBDEs from the PRD, suggesting that the majority of PBDEs inventory has been accumulated from importation of e-wastes. Because of the continuous importation of e-wastes and strong demand for brominated fire retardants, the impact of PBDEs on China's and the world's environments is expected to persist for many years to come.

  4. Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China

    Energy Technology Data Exchange (ETDEWEB)

    Yu Zhiqiang [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Liao Ru' e [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Li Huiru, E-mail: huiruli@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Mo Ligui [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Zeng Xiangying; Sheng Guoying; Fu Jiamo [State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2011-10-15

    In present study, atmospheric particles from Shanghai, the biggest city and the most important industrial base in China, were analyzed for polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DP). Concentrations of {Sigma}{sub 20}PBDEs and DP both exhibited the changing trend of industrial area > urban areas. Jiading District had the highest levels of particulate PBDEs and DP with values of 744 {+-} 152 pg/m{sup 3} and 5.48 {+-} 1.28 pg/m{sup 3}, respectively. Compared with similar data in other areas of the world, PBDEs in Shanghai were at medium pollution level, while DP was at lower level, which reflected their different production and use in Shanghai. The results from multiple linear regression analysis suggested that deca-BDE mixture was the most important contributor of particulate PBDEs in Shanghai. The fractions of anti-DP showed no significant differences to those of the technical mixtures (p > 0.05), which suggested that no obviously stereoselective process occurred in ambient air around Shanghai. - Highlights: > Atmospheric PBDEs of Shanghai were at moderate levels and dominated by BDE-209. > Particulate DP was low even Shanghai is not far from the DP manufacturing factory. > DP showed no obviously stereoselective process in air particles from Shanghai. > Significant positive correlation was found between particulate PBDEs and PBDD/Fs. - The moderate PBDEs levels with deca-BDE being the most important contributor and low DP levels in ambient air around Shanghai reflected their different usage in this area.

  5. Widespread polybrominated diphenyl ether (PBDE) contamination of urban soils in Melbourne, Australia.

    Science.gov (United States)

    McGrath, Thomas J; Morrison, Paul D; Sandiford, Christopher J; Ball, Andrew S; Clarke, Bradley O

    2016-12-01

    Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in a variety of materials and products. PBDEs have been shown to accumulate in the environment and human populations while exhibiting a range of toxic effects. In this study, surface soil samples from 30 sites in the city of Melbourne, Australia, were analysed for PBDEs. Eight congeners of environmental concern (BDE-28, -47, -99, -100, -153, -154 -183 and -209) were assessed using selective pressurized liquid extraction (S-PLE) and gas chromatography coupled to triple quadrupole mass spectrometry (GC-MS/MS). PBDEs were detected in 29/30 samples with Σ 8 PBDE soil concentrations ranging nd-13,200 ng/g dw and Σ 7 PBDEs (excluding BDE-209) levels of nd-70.5 ng/g dw. Soils from waste disposal sites (n = 6) contained the highest median Σ 7 PBDE and Σ 8 PBDE concentrations, followed by manufacturing sites (n = 18) and then non-source sites (n = 6). Electronics recycling facilities contained the greatest levels of Σ 8 PBDEs by a significant margin (p production, with the most significant congener correlation existing between BDE-47 and BDE-99 (p < 0.001, r = 0.943). This first assessment of PBDEs in Melbourne soils indicates widespread contamination of the urban environment, including locations where direct sources to soil are not clear. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Sedimentary records of hydroxylated and methoxylated polybrominated diphenyl ethers in the southern Yellow Sea.

    Science.gov (United States)

    Fan, Ying; Lan, Jing; Zhao, Zongshan; Zhao, Meixun

    2014-07-15

    Although hydroxylated (OH-) and methoxylated (MeO-) polybrominated diphenyl ethers (PBDEs) have caused much concern in recent years, few reports had discussed on their input history. In this study, we measured the contents of nine MeO-BDEs, ten OH-BDEs, and total organic carbon (TOC) of two sediment cores from the southern Yellow Sea. 6-MeO-BDE-47, 2'-MeO-BDE-68, 6-OH-BDE-47, and 2'-OH-BDE-68 were the predominant congeners in HH12, while only 2'-OH-BDE-68 and 6-OH-BDE-47 were frequently detected in core HH11. The records showed that OH-/MeO-BDEs in both cores had increased rapidly since the 1950s. Their existence was detected at the bottom layers (∼1800 s) prior to the production of PBDEs (1960s), thus OH-/MeO-BDEs originate from natural origins rather than artificial PBDEs. Comparisons between TOC and OH-/MeO-BDEs indicated that TOC is a potential factor affecting the accumulation of OH-/MeO-BDEs in marine environments. Similar trends and significant correlations between OH-BDEs and MeO-BDEs suggest their common origins or interconversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Polybrominated diphenyl ethers in sewage sludge from Shanghai, China: possible ecological risk applied to agricultural land.

    Science.gov (United States)

    Yang, Chao; Meng, Xiang-Zhou; Chen, Ling; Xia, Siqing

    2011-10-01

    Ideally, agricultural use is a treatment for the sewage sludge generated from municipal wastewater. However, this treatment probably causes ecological risks due to the occurrence of organic contaminants in sludge, which has attracted rising concerns recently. To assess the possible ecological risk, in this study, sewage sludge samples were collected from 28 wastewater treatment plants (WWTPs) in Shanghai, China for exploring the level and profile of polybrominated diphenyl ethers (PBDEs). The mean concentration of Σ18PBDE (sum of all target analytes except for BDE-209) was at the low end of global range. However, we found the highest reported BDE-209 levels (34,900 ng g(-1) dw) in sewage sludge/biosoilds to date. The annual mass loadings of penta-BDE, octa-BDE, and deca-BDE were 3.6, 0.6, and 763 kg through sludge, respectively. Following sludge application in agricultural land, the concentrations of penta-BDE, octa-BDE, and deca-BDE in soil were 0.19, 0.03, and 39.5 ng g(-1), respectively. Preliminary results indicate that the ecological risk of soil in organisms exposed to PBDEs was relatively low. Nevertheless, further studies are needed to explore the fate of PBDEs in sewage sludge due to no restriction on the usage and production of PBDEs products in China currently. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China.

    Science.gov (United States)

    Yu, Zhiqiang; Liao, Ru'e; Li, Huiru; Mo, Ligui; Zeng, Xiangying; Sheng, Guoying; Fu, Jiamo

    2011-10-01

    In present study, atmospheric particles from Shanghai, the biggest city and the most important industrial base in China, were analyzed for polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DP). Concentrations of ∑(20)PBDEs and DP both exhibited the changing trend of industrial area > urban areas. Jiading District had the highest levels of particulate PBDEs and DP with values of 744 ± 152 pg/m(3) and 5.48 ± 1.28 pg/m(3), respectively. Compared with similar data in other areas of the world, PBDEs in Shanghai were at medium pollution level, while DP was at lower level, which reflected their different production and use in Shanghai. The results from multiple linear regression analysis suggested that deca-BDE mixture was the most important contributor of particulate PBDEs in Shanghai. The fractions of anti-DP showed no significant differences to those of the technical mixtures (p > 0.05), which suggested that no obviously stereoselective process occurred in ambient air around Shanghai. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Polybrominated diphenyl ethers in indoor air in Kuwait: Implications for human exposure

    Science.gov (United States)

    Gevao, Bondi; Al-Bahloul, Majed; Al-Ghadban, Abdul Nabi; Ali, Lulwa; Al-Omair, Ali; Helaleh, Murad; Al-Matrouk, Khaled; Zafar, Jamal

    Polyurethane foam plug passive samplers were used to concurrently measure air concentrations of polybrominated diphenyl ethers (PBDEs) in 70 indoor environments. PBDEs were detected in all homes and offices investigated with patterns similar to the distribution in the commercial penta technical formulation (Bromkal 70-5DE). The ubiquitous distribution of these compounds in indoor environments may be due to the volatilization of these chemicals from foam (e.g. mattresses, foam padded furniture), electronic equipments (e.g. TVs, printers, computers) and other consumer products to which they are added as flame retardants. Mean ΣPBDEs concentration in air was log-normally distributed and ranged from ˜2-385 pg m -3. Using an inhalation rate of 8 and 20 m 3 day -1 for children and adults respectively, exposure via inhalation is estimated to be 173 and 399 pg day -1 for children and adults respectively. This study supports the growing body of evidence for the ubiquitous presence of these compounds in indoor air and the potential for continuous, low-level exposure both at work and home.

  10. GC-MS analysis of polybrominated diphenyl ethers in Lake Erie

    Science.gov (United States)

    Vagula, Mary C.; Vartak, Marissa; Tallmadge, Weslene

    2012-06-01

    Lake Erie is one of the five great lakes of North America. It is the shallowest, the warmest, and the most biologically productive of the Great Lakes producing more fish than all of the other four lakes combined. It is also a source of drinking water for 11 million people and a recreational asset. On the flipside, it is also very vulnerable and troubled with environmental challenges because it has the smallest water volume, but the greatest pressures from the human settlement. One of the many issues faced by the Lake is pollution. It receives larger loads of many pollutants than any other Great Lake. Even with the best pollution controls many pesticides and organohalogens continue to enter the lake. Polybrominated diphenyl ethers (PBDEs) are a class of flame-retardants that have been used in a variety of consumer products since the 1970s. They are added to many commercial and household products such as computers, foam mattresses, carpets, etc. Being largely non-polar and chemically stable, these chemicals are extremely lipophilic and resist degradation in the environment, thus giving them a high affinity for their bioaccumulation. Due to these properties PBDEs have become ubiquitous environmental contaminants. These compounds are reported to be endocrine disruptors and could cause oxidative damage. This report presents the sample preparation protocol, the GC-MS analysis of PBDEs in Lake Erie sediment samples.

  11. Polybrominated diphenyl ethers in atmosphere and soil of a production area in China: levels and partitioning.

    Science.gov (United States)

    Jin, Jun; Wang, Ying; Liu, Weizhi; Yang, Congqiao; Hu, Jicheng; Cui, Jian

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) were measured in atmosphere and soil samples taken in winter and summer at a PBDE production area of Laizhou Bay in China. The concentrations of Sigma11PBDE were 0.017-1.17 ng/m3 in gaseous phase, 0.5-161.1 ng/m3 in particulate phase, and 73-2629 ng/g dry weight in soil samples. The PBDE congener pattern in the gaseous phase differed from that in the particulate phase, and the PBDE congener pattern in the particulate phase was similar with that in soil. This demonstrated that there was little difference with atmospheric particle-soil transfer efficiency among PBDE congeners. In addition, there were seasonal variations in percentages on particle for lower brominated congeners. The BDE-28 was mostly in the gaseous phase in summer (88.3%), whereas the average proportion of BDE-28 in gaseous phase in winter was 38.9%. Higher brominated congeners (i.e., BDE-206, BDE-207, BDE-208, and BDE-209) were bound to the atmospheric particulate phase, and their potentials for long-range migration were mainly affected by the environmental behavior of atmospheric particles. Results indicated that PBDE congeners in summer were closer to gas-particle partition equilibrium than in winter. Temperature should be considered the main factor causing nonequilibrium in winter.

  12. Polybrominated diphenyl ethers in atmosphere and soil of a production area in China: Levels and partitioning

    Institute of Scientific and Technical Information of China (English)

    Jun Jin; Ying Wang; Weizhi Liu; Congqiao Yang; Jicheng Hu; Jian Cui

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) were measured in atmosphere and soil samples taken in winter and summer at a PBDE production area of Laizhou Bay in China. The concentrations of ∑11 PBDE were 0.017-1.17 ng/m3 in gaseous phase, 0.5-161.1 ng/m3 in particulate phase, and 73-2629 ng/g dry weight in soil samples. The PBDE congener pattern in the gaseous phase differed from that in the particulate phase, and the PBDE congener pattern in the particulate phase was similar with that in soil. This demonstrated that there was little difference with atmospheric panicle-soil transfer efficiency among PBDE congeners. In addition, there were seasonal variations in percentages on particle for lower brominated congeners. The BDE-28 was mostly in the gaseous phase in summer (88.3%),whereas the average proportion of BDE-28 in gaseous phase in winter was 38.9%. Higher brominated congeners (i.e., BDE-206, BDE207, BDE-208, and BDE-209) were bound to the atmospheric particulate phase, and their potentials for long-range migration were mainly affected by the environmental behavior of atmospheric particles. Results indicated that PBDE congeners in summer were closer to gas-particle partition equilibrium than in winter. Temperature should be considered the main factor causing nonequilibrium in winter.

  13. Photolytic debromination pathway of polybrominated diphenyl ethers in hexane by sunlight

    International Nuclear Information System (INIS)

    Wei, Hua; Zou, Yonghong; Li, An; Christensen, Erik R.; Rockne, Karl J.

    2013-01-01

    The objective of this work is to identify the photolytic debromination pathways of polybrominated diphenyl ethers (PBDEs). Thirteen PBDEs (BDEs 209, 208, 207, 206, 196, 183, 154, 153, 100, 99, 85, 47 and 28) in hexane were individually exposed to sunlight for up to 64 h. A total of 180 PBDEs were screened and 74 BDE debromination products were detected. The disappearance rate constant increased exponentially with increasing number of bromines. While no evident difference in debromination preference among ortho, meta and para bromines was found for heavier congeners, the vulnerability rank order was meta ≥ ortho > para for the lighter congeners (≤8 Br). The total molar mass of PBDEs continuously decreased during sunlight exposure, indicating PBDEs were transformed to non-PBDE compounds. A stochastic least squares debromination pathway model was developed to simulate the reactions and determine the yields to extend the results beyond the experimental observations. -- Highlights: ► 74 PBDEs are identified as the products of debromination via photolysis. ► Debromination is more likely at meta than para positions for PBDEs with ≤8 bromines. ► The stochastic least squares model results agree with and expand the experimental observations. ► Mass imbalance indicates a significant loss of PBDE mass during sunlight exposure. -- The PBDE debromination products and pathways identified in this work will assist in future studies on their environmental fate

  14. Brominated flame retardants in Chinese air before and after the phase out of polybrominated diphenyl ethers

    Science.gov (United States)

    Li, Wen-Long; Qi, Hong; Ma, Wan-Li; Liu, Li-Yan; Zhang, Zhi; Mohammed, Mohammed O. A.; Song, Wei-Wei; Zhang, Zifeng; Li, Yi-Fan

    2015-09-01

    Brominated flame retardants (BFRs), including polybrominated diphenyl ethers (PBDEs) and novel non-BDE flame retardants (NBFRs), were analyzed in Chinese air during China's POPs Soil and Air Monitoring Program Phase I (SAMP-I) and Phase II (SAMP-II). The levels of Σ12PBDEs and Σ6NBFRs in urban sites were significantly higher than those in rural sites and background sites. The higher detection rate and concentrations of high molecular weight PBDEs and NBFRs in Phase II indicated the changing of the commercial pattern of BFRs after the phase out of PBDEs in China. Temperature was the major factor affecting the seasonal variations of molecular weight BFRs in atmosphere. A significant correlation between BFRs concentration and gross domestic product (GDP) was observed, with the GDP parameter explained 59.4% and 72.7% of the total variability for Octa-BDEs and low molecular weight NBFRs, respectively. Our findings indicated an evolving commercial usage of BFRs from SAMP-I to SAMP-II, i.e. shifting from lower molecular weight to higher molecular weight congeners in China.

  15. Emission factors of polybrominated diphenyl ethers (PBDEs) from plastics processing and recycling facilities

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Shin-ichi; Hirai, Yasuhiro [National Institute for Environmental Studies, Tsukuba (Japan); Ota, Shizuko; Sudo, Kinichi [Ministry of Environment (Japan)

    2004-09-15

    With regard to polybrominated diphenyl ether (PBDE), there is few scientific knowledge on the emission patterns into the environment and exposure pathways to humans, and basic information is insufficient to consider what measures effective are. For the purpose of promoting risk reduction of target substances more effectively and efficiently, it is desirable to comprehend accurately the causal chain from the target substances utilization to the risk intake, and to evaluate the measures covering the whole applications of target substances. As the existing researches on the PBDE emission inventory, there are EU risk assessment report (European Chemical Bureau 2000, 2002, 2003), Danish EPA (1999), Palm et al.(2002) and Alcock et al. (2003). In addition, emissions of DecaBDE are published in TRI (Toxic Release Inventory) of US EPA. However, the primary information of the previous inventories is often the same and estimations based on the measured values are few. In light of the situation, PBDE emission concentrations from processing facilities of flame retardant plastics and recycling facilities of home electric appliances are measured in practice to presume material flow of PBDE and to estimate emission factors and inventories from each phase of life cycles. The validities of emission factors are examined in comparison to measured values of atmospheric depositions surroundings, which are close to sources.

  16. Quantitative analysis of 39 polybrominated diphenyl ethers by isotope dilution GC/low-resolution MS.

    Science.gov (United States)

    Ackerman, Luke K; Wilson, Glenn R; Simonich, Staci L

    2005-04-01

    A GC/low-resolution MS method for the quantitative isotope dilution analysis of 39 mono- to heptabrominated diphenyl ethers was developed. The effects of two different ionization sources, electron impact (EI) and electron capture negative ionization (ECNI), and the effects of their parameters on production of high-mass fragment ions [M - xH - yBr](-) specific to PBDEs were investigated. Electron energy, emission current, source temperature, ECNI system pressure, and choice of ECNI reagent gases were optimized. Previously unidentified enhancement of PBDE high-mass fragment ion [M - xH - yBr](-) abundance was achieved. Electron energy had the largest impact on PBDE high-mass fragment ion abundance for both the ECNI and EI sources. By monitoring high-mass fragment ions of PBDEs under optimized ECNI source conditions, quantitative isotope dilution analysis of 39 PBDEs was conducted using nine (13)C(12) labeled PBDEs on a low-resolution MS with low picogram to femtogram instrument detection limits.

  17. Disruption of thyroid hormone binding to sea bream recombinant transthyretin by ioxinyl and polybrominated diphenyl ethers.

    Science.gov (United States)

    Morgado, Isabel; Hamers, Timo; Van der Ven, Leo; Power, D M

    2007-08-01

    A number of chemicals released into the environment share structural similarity to the thyroid hormones (THs), thyroxine (T(4)) and triiodothyronine (T(3)) and it is thought that they may interfere with the thyroid axis and behave as endocrine disruptors (EDs). One of the ways by which such environmental contaminants may disrupt the TH axis is by binding to TH transporter proteins. Transthyretin (TTR) is one of the thyroid hormone binding proteins responsible for TH transport in the blood. TTR forms a stable tetramer that binds both T(4) and T(3) and in fish it is principally synthesized in the liver but is also produced by the brain and intestine. In the present study, we investigate the ability of some chemicals arising from pharmaceutical, industrial or agricultural production and classified as EDs, to compete with [I(125)]-T(3) for sea bream recombinant TTR (sbrTTR). Ioxinyl, a common herbicide and several polybrominated diphenyl ethers were strong inhibitors of [I(125)]-T(3) binding to TTR and some showed even greater affinity than the natural ligand T(3). The TTR competitive binding assay developed offers a quick and effective tool for preliminary risk assessment of chemicals which may disrupt the thyroid axis in teleost fish inhabiting vulnerable aquatic environments.

  18. Induction of Adipocyte Differentiation by Polybrominated Diphenyl Ethers (PBDEs) in 3T3-L1 Cells

    Science.gov (United States)

    Tung, Emily W. Y.; Boudreau, Adèle; Wade, Michael G.; Atlas, Ella

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are a class of brominated flame retardants that were extensively used in commercial products. PBDEs are ubiquitous environmental contaminants that are both lipophilic and bioaccumulative. Effects of PBDEs on adipogenesis were studied in the 3T3-L1 preadipocyte cell model in the presence and absence of a known adipogenic agent, dexamethasone (DEX). A PBDE mixture designed to mimic body burden of North Americans was tested, in addition to the technical mixture DE-71 and the individual congener BDE-47. The mixture, DE-71, and BDE-47 all induced adipocyte differentiation as assessed by markers for terminal differentiation [fatty acid binding protein 4 (aP2) and perilipin] and lipid accumulation. Characterization of the differentiation process in response to PBDEs indicated that adipogenesis induced by a minimally effective dose of DEX was enhanced by these PBDEs. Moreover, C/EBPα, PPARγ, and LXRα were induced late in the differentiation process. Taken together, these data indicate that adipocyte differentiation is induced by PBDEs; they act in the absence of glucocorticoid and enhance glucocorticoid-mediated adipogenesis. PMID:24722056

  19. Gridded field observations of polybrominated diphenyl ethers in soils of North China.

    Science.gov (United States)

    Liu, Di; Ma, Jin; Qiu, Xinghua; Zhao, Yifan; Lin, Yan; Yang, Qiaoyun; Gao, Zhenji; Zhu, Tong

    2014-05-01

    Polybrominated diphenyl ethers (PBDEs) were measured in 87 soil samples collected from North China. Eleven PBDE congeners (BDE28, 47, 49, 66, 99, 100, 119, 183, 196, 203, and 209) were identified with a high frequency of detection (84-100 %) in soil samples, and their frequencies were used for statistical analysis in the present study. PBDE concentrations ranged from 0.08 to 8260 ng/g with a mean of 202 ng/g, thus indicating severe pollution at these sample sites. BDE209 was the predominant congener with concentrations of 0.08-8140 ng/g (mean 188). Analysis of the spatial distribution of PBDEs in North China soils indicated that relatively high concentrations of both lower- and higher-brominated BDEs were present in Shandong Province, and a decreasing trend in PBDE concentrations from the east toward the west of North China was observed. Source identification analysis suggested that Jinghai County in Tianjin and the coastal area of Laizhou Bay, Shandong province, were the major sources in North China. The sources in Jinghai County were connected with the dismantling of electronic waste, whereas the sources in the coastal area of Laizhou Bay were connected with the production of PBDEs. Modeling results showed that the distance between the sampling sites and these point sources had a large influence on the transfer of PBDEs.

  20. Particle-bound Dechlorane Plus and polybrominated diphenyl ethers in ambient air around Shanghai, China

    International Nuclear Information System (INIS)

    Yu Zhiqiang; Liao Ru'e; Li Huiru; Mo Ligui; Zeng Xiangying; Sheng Guoying; Fu Jiamo

    2011-01-01

    In present study, atmospheric particles from Shanghai, the biggest city and the most important industrial base in China, were analyzed for polybrominated diphenyl ethers (PBDEs) and Dechlorane Plus (DP). Concentrations of Σ 20 PBDEs and DP both exhibited the changing trend of industrial area > urban areas. Jiading District had the highest levels of particulate PBDEs and DP with values of 744 ± 152 pg/m 3 and 5.48 ± 1.28 pg/m 3 , respectively. Compared with similar data in other areas of the world, PBDEs in Shanghai were at medium pollution level, while DP was at lower level, which reflected their different production and use in Shanghai. The results from multiple linear regression analysis suggested that deca-BDE mixture was the most important contributor of particulate PBDEs in Shanghai. The fractions of anti-DP showed no significant differences to those of the technical mixtures (p > 0.05), which suggested that no obviously stereoselective process occurred in ambient air around Shanghai. - Highlights: → Atmospheric PBDEs of Shanghai were at moderate levels and dominated by BDE-209. → Particulate DP was low even Shanghai is not far from the DP manufacturing factory. → DP showed no obviously stereoselective process in air particles from Shanghai. → Significant positive correlation was found between particulate PBDEs and PBDD/Fs. - The moderate PBDEs levels with deca-BDE being the most important contributor and low DP levels in ambient air around Shanghai reflected their different usage in this area.

  1. Levels and pattern of polybrominated diphenyl ethers in eggs of Antarctic seabirds: Endemic versus migratory species

    Energy Technology Data Exchange (ETDEWEB)

    Yogui, G.T. [Geochemical and Environmental Research Group, College of Geosciences, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: gtyogui@ocean.tamu.edu; Sericano, J.L. [Geochemical and Environmental Research Group, College of Geosciences, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: jsericano@gerg.tamu.edu

    2009-03-15

    Chinstrap and gentoo penguins are endemic species that live year round south of the Antarctic Convergence. South polar skua is a migratory seabird that can be observed in Antarctica during the breeding season (i.e., austral summer). This study compares concentration and pattern of polybrominated diphenyl ethers (PBDEs) in eggs of seabirds breeding at King George Island, Antarctic Peninsula. PBDEs in south polar skua eggs are approximately 20 times higher than in penguin eggs suggesting that skuas are more exposed to contaminants during the non-breeding season when they migrate to waters of the northern hemisphere. The pattern of PBDE congeners also differs between south polar skua and penguin eggs. The latter exhibited a pattern similar to that found in the local biota. In contrast, the congener pattern in south polar skua eggs suggests that birds breeding at King George Island may winter in the northwestern Pacific Ocean. - Skua and penguin eggs collected at King George Island have different concentration and pattern of PBDEs.

  2. Metals and polybrominated diphenyl ethers leaching from electronic waste in simulated landfills

    Energy Technology Data Exchange (ETDEWEB)

    Kiddee, Peeranart [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Mawson Lakes Campus, Adelaide, 5095 (Australia); Naidu, Ravi, E-mail: ravi.naidu@crccare.com [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Adelaide, 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of the Environment, Mawson Lakes Campus, Adelaide, 5095 (Australia); Wong, Ming H. [Croucher Institute for Environmental Sciences, and Department of Biology, Hong Kong Baptist University, Kowloon Tong (China)

    2013-05-15

    Highlights: • Simulated landfill columns provided realistic results than lab based column study. • Column leachates showed significant seasonal effect on toxic substances. • Toxic substances in the landfill leachates pose environmental and health hazards. • A better management of e-waste is urgently needed. -- Abstract: Landfills established prior to the recognition of potential impacts from the leaching of heavy metals and toxic organic compounds often lack appropriate barriers and pose significant risks of contamination of groundwater. In this study, bioavailable metal(oids) and polybrominated diphenyl ethers (PBDEs) in leachates from landfill columns that contained intact or broken e-waste were studied under conditions that simulate landfills in terms of waste components and methods of disposal of e-wastes, and with realistic rainfall. Fourteen elements and PBDEs were analysed in leachates over a period of 21 months. The results demonstrate that the average concentrations of Al, Ba, Be, Cd, Co, Cr, Cu, Ni, Pb, Sb and V in leachates from the column that contained broken e-waste items were significantly higher than the column without e-waste. BDE-153 was the highest average PBDEs congener in all columns but the average of ∑PBDEs levels in columns that contained intact e-waste were (3.7 ng/l) and were not significantly higher than that in the leachates from the control column.

  3. [Atmospheric Polybrominated Diphenyl Ethers in Eight Cities of China: Pollution Characteristics and Human Exposure].

    Science.gov (United States)

    Lin, Hai-tao; Li, Qi-lu; Zhang, Gan; Li, Jun

    2016-01-15

    The gas and particle samples of eight cities were collected by high flow active air sampler in the Eastern and Western China and eight congeners of polybrominated diphenyl ethers were analyzed. The results showed that the concentration of BDE-28 (tri-BDE) in the gas-phase (three bromide components) was the highest, which was different from previous studies where BDE-99 and-47 were the predominant homologues in the gas-phase while the concentration of BDE-209 [(25.4 ± 124) pg · m⁻³] in particle-phase was the highest. The atmospheric concentrations of PBDEs in Beijing and Guangzhou were relatively higher, especially the BDE-209 concentration in particle phases of Guangzhou was two orders higher than those of other cities. However, the atmospheric concentrations of PBDEs declined significantly when compared with the data from previous studies. Meanwhile, the results indicated that the gas-phase concentrations decreased slowly and the particle-phase concentrations decreased rapidly. Combined with the results of correlation analysis, this phenomenon might be ascribed to the ceased commercial production of penta- and octa-BDE, the light degradation of high bromide components and reduced concentrations of atmospheric particles in urban area. Inhalation exposure for infants was about 2-3 times higher than that of adults. This reflected that the potential health risk of atmospheric PBDEs in city for residents, especially infants and young children, should not be ignored.

  4. Risk assessments of polybrominated diphenyl ethers (PBDEs) during sludge application in China

    Science.gov (United States)

    Qian, Jun

    2018-02-01

    Due to increasingly less space in municipal environment, waste management has become an urgent issue worldwide. As one of common municipal waste, sewage sludge from wastewater treatment plants (WWTPs) contains abundant nutrients, some of which can be quite essential for plant growth. In consideration of nutrient recycling and energy saving, sludge application has been frequently promoted in many countries across the world. However, even after several sludge stabilization procedures, sewage sludge may still contain a large variety of toxic pollutants, especially some emerging organic contaminants (EOCs). Applied in various household products and plastic industries as additives, polybrominated diphenyl ethers (PBDEs) have been constantly detected in sewage sludge samples from several cities in China since 2005, as well as some biosolid samples after sludge stabilization processes, suggesting their strong persistence and wide occurrence. During sludge application onto farmland soils, PBDEs may desorb from sludge particles and get attached by soil organic matter (SOM), followed by plant root uptake and translocation to aboveground tissues. In this study, data about current pollution of PBDEs in sewage sludge samples from China was reviewed, and the potential risks during sludge application was comprehensively assessed.

  5. Diphenyl ditelluride impairs short-term memory and alters neurochemical parameters in young rats.

    Science.gov (United States)

    Stangherlin, Eluza Curte; Rocha, João Batista Teixeira; Nogueira, Cristina Wayne

    2009-01-01

    The aim of this study was to investigate if maternal exposure to 0.03 mg/kg of diphenyl ditelluride (PhTe)2 during the first 14 days of lactational period in Wistar rats alters recognition memory and neurochemical parameters in young rats. Object recognition memory task, evaluation of synaptosomal [3H]glutamate uptake and release as well as cerebral Na+/K+ATPase activity were evaluated in 4 week-old rats. There were no significant specific overt signs of maternal intoxication. The body weight gain of rats was similar among groups. (PhTe)2-exposed group showed a significantly lower time exploring the novel object when compared to the performance of the control group in short-term memory (STM) test. In addition, (PhTe)2 significantly inhibited synaptosomal [3H]glutamate uptake and cerebral Na+/K+ATPase activity in animals. The synaptosomal [3H]glutamate release was similar between (PhTe)2 and control groups. In conclusion, the present study establishes that young rats presented cognitive impairment after exposure to (PhTe)2 via maternal milk, demonstrated by the performance of animals in object recognition memory task. The possible mechanism involved in (PhTe)2 action in memory of recognition might involve inhibition of cerebral Na+/K+ATPase activity and synaptosomal [3H]glutamate uptake.

  6. Brominated diphenyl ether levels. A comparison of tributary sediments versus biosolid material

    Energy Technology Data Exchange (ETDEWEB)

    Kolic, T.M.; MacPherson, K.A.; Reiner, E.J. [Ontario Ministry of the Environment, Laboratory Services Branch, Toronto, ON (Canada); Ho, T.; Kleywegt, S. [Ontario Ministry of the Environment, Standards Development Branch, Toronto, ON (Canada); Dove, A.; Marvin, C. [Environment Canada, Burlington, ON (Canada)

    2004-09-15

    PBDEs are persistent in the environment, have low water solubility and are known to have a tendency to bioaccumulate in wildlife and humans. There are 209 possible PBDE congeners. There has been concern over the bioaccumulation of these compounds since they have been found in mother's milk. Some of the brominated diphenyl ethers are known to metabolize into hydroxylated compounds and these metabolites are known to compete with and reduce thyroxine (T4) from binding to the thyroxine binding protein, transthyretin. This disrupts the thyroid hormone system interaction that has recently been notable amongst women in the form of hypothyroidism that can affect the fetus development in the form of neurodevelopmental deficits. There have been reports of estrogenic activities regarding PBDEs and their hydroxylated counterparts. Information such as this is indicative that PBDEs are endocrine disruptors. Due to their lipophilic nature, PBDEs have a high binding affinity to particulates and accumulate in sediments. Various reports on sediments and sludge type matrices have been reported in Austria, Switzerland, Netherlands and Canada. The following paper is a presentation of levels of PBDEs found in Tributary sediments and their comparison of levels to nearby biosolid sampling locations along Lake Ontario.

  7. Diphenyl Ditelluride Intoxication Triggers Histological Changes in Liver, Kidney, and Lung of Mice

    Directory of Open Access Journals (Sweden)

    Sônia Cristina Almeida da Luz

    2015-01-01

    Full Text Available Tellurium compounds may be cytotoxic to different cells types. Thus, this work evaluated the effect of diphenyl ditelluride ((PhTe2, an organotellurium commonly used in organic synthesis, on the morphology of liver, kidney, and lung. Adult mice were acutely (a subcutaneous single dose: 250 μmol/kg or subchronically (one daily subcutaneous dose: 10 or 50 μmol/kg for 7 and 14 days exposed to (PhTe2. Afterwards, the histological analyses of liver, kidney, and lungs were performed. Liver histology revealed that the hepatocytes of mice subchronically exposed to (PhTe2 presented cytoplasmic vacuolization, hydropic degeneration, and hyperchromatic nuclei. Subchronic exposure to 50 μmol/kg (PhTe2 also caused hepatic necrosis. Microvesicular and macrovesicular steatosis were identified in liver of mice acutely exposed to (PhTe2. Acute and subchronic intoxication with (PhTe2 induced changes on epithelial cells of renal tubules, namely, loss of brush border and cytoplasmatic vacuolization. Atrophy and hypertrophy, cast proteinaceous formation, and acute tubular necrosis were also identified in renal tissue. Mice subchronically exposed to 50 μmol/kg (PhTe2 developed intra-alveolar edema and alveolar wall congestion in some areas of lungs. Acute exposure to (PhTe2 did not cause histological changes in lungs. Our data show that (PhTe2 may be considered a histotoxic agent for liver, kidney, and lung.

  8. Particle size fractionation and human exposure of polybrominated diphenyl ethers in indoor dust from Chicago.

    Science.gov (United States)

    Wei, Hua; Turyk, Mary; Cali, Salvatore; Dorevitch, Samuel; Erdal, Serap; Li, An

    2009-11-01

    The objective of this study was to investigate the concentration level, the mass distribution based on dust particle size, and the associated human exposure of polybrominated diphenyl ethers (PBDEs) in indoor dust. The total concentration of 13 PBDEs Sigma(13)(BDEs) was found to be 500-6,944 ng/g in indoor dusts, 4,000 ng/g in car interior dust, 260-300 ng/g in outdoor ambient air particles, 30 ng/g in carpet fibers, and as high as 0.5% in carpet padding. Selected dust samples were fractionated based on particle size, and over 80% of the Sigma(13)BDEs were associated with particles exposure of Americans to PBDEs via hand-to-mouth transfer of house dust was estimated under the central tendency exposure and reasonable maximum exposure scenarios. The results suggest that ingestion of PBDE-laden house dust via hand-to-mouth contact is likely a significant exposure pathway, especially for children.

  9. Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building.

    Science.gov (United States)

    Ni, Hong-Gang; Cao, Shan-Ping; Chang, Wen-Jing; Zeng, Hui

    2011-07-01

    This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM(2.5) (Particulate Matter up to 2.5 μm in size) bounded Σ(15)PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM(10) (Particulate Matter up to 10 μm in size) bounded Σ(15)PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ(15)PBDEs via dust inhalation and ingestion for adults reached ∼ 141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. Copyright © 2010 Elsevier Ltd. All rights reserved.

  10. Uptake of polybrominated diphenyl ethers by carrot and lettuce crops grown in compost-amended soils.

    Science.gov (United States)

    Bizkarguenaga, E; Iparraguirre, A; Oliva, E; Quintana, J B; Rodil, R; Fernández, L A; Zuloaga, O; Prieto, A

    2016-02-01

    The uptake of polybrominated diphenyl ethers (PBDEs) by carrot and lettuce was investigated. Degradation of PBDEs in soil in the absence of the plants was discarded. Different carrot (Nantesa and Chantenay) and lettuce (Batavia Golden Spring and Summer Queen) varieties were grown in fortified or contaminated compost-amended soil mixtures under greenhouse conditions. After plant harvesting, roots (core and peel) and leaves were analyzed separately for carrot, while for lettuce, leaves and hearts were analyzed together. The corresponding bioconcentration factors (BCFs) were calculated. In carrots, a concentration gradient of 2,2',3,4,4',5'-hexabromodiphenyl ether (BDE-138) became evident that decreased from the root peel via root core to the leaves. For decabromodiphenyl ether (BDE-209) at the low concentration level (7 and 20 ng g(-1)), the leaves incorporated the highest concentration of the target substance. For lettuce, a decrease in the BCF value (from 0.24 to 0.02) was observed the higher the octanol-water partition coefficient, except in the case of BDE-183 (BCF = 0.51) and BDE-209 (BCF values from 0.41 to 0.74). Significant influence of the soils and crop varieties on the uptake could not be supported. Metabolic debromination, hydroxylation or methylation of the target PBDEs in the soil-plant system was not observed.

  11. Measurement of polybrominated diphenyl ethers in environmental matrix standard reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Stapleton, H.; Schantz, M.; Wise, S. (National Institute of Standards and Technology)

    2004-09-15

    Polybrominated diphenyl ethers (PBDEs) are a class of emerging contaminants of concern as many studies have now demonstrated that these compounds are bioaccumulative, persistent and increasing in concentration in the environment. PBDEs are being detected in almost every environmental sample examined, and they have even been measured in samples collected in the Arctic, further demonstrating their persistence and potential for long range transport. More and more studies are continuing to examine the fate and transport of these flame retardant compounds in environmental samples and as such, reference materials are needed to provide quality control on these measurements. The National Institute of Standards and Technology (NIST) supports a national Standard Reference Material (SRM) program for measurement of organic contaminants such as PCBs, PAHs and chlorinated pesticides in environmental matrices. This current study was undertaken to provide reference measurements for PBDEs in selected SRMs that are currently used by various laboratories throughout the United States. These SRMs include matrices such as marine mammal blubber, lake trout tissue, mussel tissue, sediment, house dust and human serum. We report here reference values for 22 PBDE congeners that have been quantified in these seven types of SRMs.

  12. Polybrominated diphenyl ethers in pinnipeds stranded along the southern California coast

    International Nuclear Information System (INIS)

    Meng Xiangzhou; Blasius, Mary Ellen; Gossett, Richard W.; Maruya, Keith A.

    2009-01-01

    Little to no information exists for polybrominated diphenyl ethers (PBDEs) in marine mammals frequenting the highly urbanized southern California (USA) coast. Fourteen PBDE congeners were determined by GC-ECNI-MS in blubber of pinnipeds stranded locally between 1994 and 2006. Total PBDE concentrations (ΣPBDE) in California sea lion (n = 63) ranged from 0.04 to 33.7 μg/g wet weight (mean: 5.24 μg/g). To our knowledge, these are the highest reported PBDE levels in marine mammals to date. By comparison, mean ΣPBDE in Pacific harbor seals (n = 9) and northern elephant seals (n = 16) were 0.96 and 0.09 μg/g, respectively. PBDEs in adult males were higher than for adult females, however, no age class differences or temporal trends were observed. As the first PBDE data reported for marine mammals in this region, the elevated levels underscore the need for additional studies on the sources, temporal trends, and potential effects of PBDEs in highly urbanized coastal zones. - Levels of PBDEs in pinnipeds found stranded along the southern California coast (USA) between 1994 and 2006 are the highest reported to date for marine mammals.

  13. Polybrominated diphenyl ethers in marine ecosystems of the American continents: foresight from current knowledge.

    Science.gov (United States)

    Shaw, Susan D; Kannan, Kurunthachalam

    2009-01-01

    Polybrominated diphenyl ethers (PBDEs) are a class of synthetic halogenated organic compounds used in commercial and household products, such as textiles, furniture, and electronics, to increase their flame ignition resistance and to meet fire safety standards. The demonstrated persistence, bioaccumulation, and toxic potential of these compounds in animals and in humans are of increasing concern. The oceans are considered global sinks for PBDEs, as higher levels are found in marine organisms than in terrestrial biota. For the past three decades, North America has dominated the world market demand for PBDEs, consuming 95% of the penta-BDE formulation. Accordingly, the PBDE concentrations in marine biota and people from North America are the highest in the world and are increasing. Despite recent restrictions on penta- and octa-BDE commercial formulations, penta-BDE containing products will remain a reservoir for PBDE release for years to come, and the deca-BDE formulation is still in high-volume use. In this paper, we review all available data on the occurrence and trends of PBDEs in the marine ecosystems (air, water, sediments, invertebrates, fish, seabirds, and marine mammals) of North and South America. We outline here our concerns about the potential future impacts of large existing stores of banned PBDEs in consumer products, and the vast and growing reservoirs of deca-BDE as well as new and naturally occurring brominated compounds on marine ecosystems.

  14. Polybrominated diphenyl ethers in pinnipeds stranded along the southern California coast

    Energy Technology Data Exchange (ETDEWEB)

    Meng Xiangzhou [Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626 (United States); Blasius, Mary Ellen; Gossett, Richard W. [Institute for Integrated Research in Materials, Environments and Society (IIRMES), California State University, Long Beach, 1250 Bellflower Blvd, Long Beach, CA 90840 (United States); Maruya, Keith A., E-mail: keithm@sccwrp.or [Southern California Coastal Water Research Project, 3535 Harbor Blvd, Suite 110, Costa Mesa, CA 92626 (United States)

    2009-10-15

    Little to no information exists for polybrominated diphenyl ethers (PBDEs) in marine mammals frequenting the highly urbanized southern California (USA) coast. Fourteen PBDE congeners were determined by GC-ECNI-MS in blubber of pinnipeds stranded locally between 1994 and 2006. Total PBDE concentrations (SIGMAPBDE) in California sea lion (n = 63) ranged from 0.04 to 33.7 mug/g wet weight (mean: 5.24 mug/g). To our knowledge, these are the highest reported PBDE levels in marine mammals to date. By comparison, mean SIGMAPBDE in Pacific harbor seals (n = 9) and northern elephant seals (n = 16) were 0.96 and 0.09 mug/g, respectively. PBDEs in adult males were higher than for adult females, however, no age class differences or temporal trends were observed. As the first PBDE data reported for marine mammals in this region, the elevated levels underscore the need for additional studies on the sources, temporal trends, and potential effects of PBDEs in highly urbanized coastal zones. - Levels of PBDEs in pinnipeds found stranded along the southern California coast (USA) between 1994 and 2006 are the highest reported to date for marine mammals.

  15. Polybrominated diphenyl ethers (PBDEs) in indoor and outdoor window organic films in Izmir, Turkey

    International Nuclear Information System (INIS)

    Cetin, Banu; Odabasi, Mustafa

    2011-01-01

    Polybrominated diphenyl ether (PBDE) concentrations of outdoor and indoor organic films on window glasses were measured at different locations (offices, laboratories, and homes in urban, suburban, rural, and industrial sites) in Izmir, Turkey. Σ 7 PBDE concentrations were dominated by technical penta and deca-BDE mixture components. Average total outdoor PBDE (Σ 7 PBDE) concentrations for suburban, urban, and industrial sites were 43.5, 45.5, and 206 ng m -2 , respectively. This spatial gradient (industrial > urban > suburban concentrations) was similar to one observed for ambient air concentrations recently in Izmir, Turkey. The highest concentrations measured in the industrial area were attributed to the significant PBDE emissions from several steel plants located in the area. Air-organic film partitioning modeling results have suggested that organic films can be used in conjunction with the dynamic uptake model to approximate the gas-phase ambient air concentrations. Modeling results have also indicated that congeners in the gas-phase with very large octanol-air partition coefficients (i.e., BDE-154, -153, and -209) will require several months to approach equilibrium with the surface films. This finding may have important implications for gas-particle and gas-film partitioning, transport, and photolytic degradation of atmospheric PBDEs.

  16. Modification of nylon-6 with semi-rigid poly (p-diphenyl oxide terephthalamide)

    International Nuclear Information System (INIS)

    Lin, M.F.; Wang, H.H.; Shu, Y.C.

    1994-01-01

    In this study, the flexible nylon-6 was reinforced by the semi-rigid aromatic polyamide, poly (p-diphenyl oxide terephthalamide) (POA), through physical polybending and chemical copolymerization using p-aminophenylacetic acid (P-APA) as a coupling agent. From the DSC measurements, it was shown that Tg of the polyblends was increased with the increase of POA content. The Tg and Tm of multiblock copolyamides were found to be higher than those of polyblends and triblock copolyamides. From the Rheovibron measurements, it was shown that the POA with nylon-6 poy-blends exhibited higher E' and Tg value than that of nylon-6, which increased with the increase of POA content. The Tg and E' values of multiblock copolyamides were higher than those of polyblends triblock copolyamides. Scanning electron microscopy revealed that the polyblends were a dispersed phase structure, although the multiblock copolyamides exhibited a homogeneous texture rather than an aggregated one. From the wide-angle x-ray diffraction pattern, the triblock copolyamides and polyblends had two diffraction peaks, i.e., 2 θ = 20.5 degrees and 24 degrees. However, the multiblock had only one at 2 θ = 20 degrees, which indicates that a different crystal structure of multiblock copolyamides. For the mechanical properties, it was found that the multiblock copolyamides had a more significant reinforcing effect than those of polyblends and triblock copolyamides. 21 refs., 11 figs., 5 tabs

  17. Electronic properties of diphenyl-s-tetrazine and some related oligomers. An spectroscopic and theoretical study

    International Nuclear Information System (INIS)

    Moral, Mónica; García, Gregorio; Peñas, Antonio; Garzón, Andrés; Granadino-Roldán, José M.; Melguizo, Manuel; Fernández-Gómez, Manuel

    2012-01-01

    Highlights: ► We study properties of Ph 2 Tz and (PhTz) n Ph as candidates for organic electronics. ► The synthesis of Ph 2 Tz was performed through a modified Pinner-type reaction. ► IR/Raman spectra allowed to conclude that Ph 2 Tz is nearly planar in liquid phase. ► Electronic structure was studied by UV–Vis/TD-DFT methods in different solvents. ► Bandgap, E LUMO , electron mobility predict some n-type character for limit polymer. -- Abstract: This work presents a theoretical and spectroscopic study on the electronic and structural properties of the diphenyl-s-tetrazine molecule (Ph 2 Tz) and some oligomeric derivatives. Ph 2 Tz was synthesized through a variation of Pinner-type reaction which uses N-acetylcysteine as catalyst. Insight into the structure and electronic properties of the title compound was obtained through IR, Raman, UV–Vis spectra in different solvents, and theoretical calculations. Theoretical studies have been extended to different n-mers derivatives up to an ideal molecular wire through the oligomeric approximation, predicting this way electronic properties such as LUMO energy levels, electron affinity and reorganization energy in order to assess their possible applications in molecular electronics.

  18. Levels and pattern of polybrominated diphenyl ethers in eggs of Antarctic seabirds: Endemic versus migratory species

    International Nuclear Information System (INIS)

    Yogui, G.T.; Sericano, J.L.

    2009-01-01

    Chinstrap and gentoo penguins are endemic species that live year round south of the Antarctic Convergence. South polar skua is a migratory seabird that can be observed in Antarctica during the breeding season (i.e., austral summer). This study compares concentration and pattern of polybrominated diphenyl ethers (PBDEs) in eggs of seabirds breeding at King George Island, Antarctic Peninsula. PBDEs in south polar skua eggs are approximately 20 times higher than in penguin eggs suggesting that skuas are more exposed to contaminants during the non-breeding season when they migrate to waters of the northern hemisphere. The pattern of PBDE congeners also differs between south polar skua and penguin eggs. The latter exhibited a pattern similar to that found in the local biota. In contrast, the congener pattern in south polar skua eggs suggests that birds breeding at King George Island may winter in the northwestern Pacific Ocean. - Skua and penguin eggs collected at King George Island have different concentration and pattern of PBDEs

  19. Estimating stepwise debromination pathways of polybrominated diphenyl ethers with an analogue Markov Chain Monte Carlo algorithm.

    Science.gov (United States)

    Zou, Yonghong; Christensen, Erik R; Zheng, Wei; Wei, Hua; Li, An

    2014-11-01

    A stochastic process was developed to simulate the stepwise debromination pathways for polybrominated diphenyl ethers (PBDEs). The stochastic process uses an analogue Markov Chain Monte Carlo (AMCMC) algorithm to generate PBDE debromination profiles. The acceptance or rejection of the randomly drawn stepwise debromination reactions was determined by a maximum likelihood function. The experimental observations at certain time points were used as target profiles; therefore, the stochastic processes are capable of presenting the effects of reaction conditions on the selection of debromination pathways. The application of the model is illustrated by adopting the experimental results of decabromodiphenyl ether (BDE209) in hexane exposed to sunlight. Inferences that were not obvious from experimental data were suggested by model simulations. For example, BDE206 has much higher accumulation at the first 30 min of sunlight exposure. By contrast, model simulation suggests that, BDE206 and BDE207 had comparable yields from BDE209. The reason for the higher BDE206 level is that BDE207 has the highest depletion in producing octa products. Compared to a previous version of the stochastic model based on stochastic reaction sequences (SRS), the AMCMC approach was determined to be more efficient and robust. Due to the feature of only requiring experimental observations as input, the AMCMC model is expected to be applicable to a wide range of PBDE debromination processes, e.g. microbial, photolytic, or joint effects in natural environments. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Polybrominated diphenyl ethers (PBDEs) in indoor and outdoor window organic films in Izmir, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Cetin, Banu [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Kaynaklar Campus, 35160 Buca, Izmir (Turkey); Odabasi, Mustafa, E-mail: mustafa.odabasi@deu.edu.tr [Department of Environmental Engineering, Faculty of Engineering, Dokuz Eylul University, Kaynaklar Campus, 35160 Buca, Izmir (Turkey)

    2011-01-30

    Polybrominated diphenyl ether (PBDE) concentrations of outdoor and indoor organic films on window glasses were measured at different locations (offices, laboratories, and homes in urban, suburban, rural, and industrial sites) in Izmir, Turkey. {Sigma}{sub 7}PBDE concentrations were dominated by technical penta and deca-BDE mixture components. Average total outdoor PBDE ({Sigma}{sub 7}PBDE) concentrations for suburban, urban, and industrial sites were 43.5, 45.5, and 206 ng m{sup -2}, respectively. This spatial gradient (industrial > urban > suburban concentrations) was similar to one observed for ambient air concentrations recently in Izmir, Turkey. The highest concentrations measured in the industrial area were attributed to the significant PBDE emissions from several steel plants located in the area. Air-organic film partitioning modeling results have suggested that organic films can be used in conjunction with the dynamic uptake model to approximate the gas-phase ambient air concentrations. Modeling results have also indicated that congeners in the gas-phase with very large octanol-air partition coefficients (i.e., BDE-154, -153, and -209) will require several months to approach equilibrium with the surface films. This finding may have important implications for gas-particle and gas-film partitioning, transport, and photolytic degradation of atmospheric PBDEs.

  1. Quantitative structure-property relationships for octanol-water partition coefficients of polybrominated diphenyl ethers.

    Science.gov (United States)

    Li, Linnan; Xie, Shaodong; Cai, Hao; Bai, Xuetao; Xue, Zhao

    2008-08-01

    Theoretical molecular descriptors were tested against logK(OW) values for polybrominated diphenyl ethers (PBDEs) using the Partial Least-Squares Regression method which can be used to analyze data with many variables and few observations. A quantitative structure-property relationship (QSPR) model was successfully developed with a high cross-validated value (Q(cum)(2)) of 0.961, indicating a good predictive ability and stability of the model. The predictive power of the QSPR model was further cross-validated. The values of logK(OW) for PBDEs are mainly governed by molecular surface area, energy of the lowest unoccupied molecular orbital and the net atomic charges on the oxygen atom. All these descriptors have been discussed to interpret the partitioning mechanism of PBDE chemicals. The bulk property of the molecules represented by molecular surface area is the leading factor, and K(OW) values increase with the increase of molecular surface area. Higher energy of the lowest unoccupied molecular orbital and higher net atomic charge on the oxygen atom of PBDEs result in smaller K(OW). The energy of the lowest unoccupied molecular orbital and the net atomic charge on PBDEs oxygen also play important roles in affecting the partition of PBDEs between octanol and water by influencing the interactions between PBDEs and solvent molecules.

  2. Passive air sampling of polychlorinated biphenyls, organochlorine compounds, and polybrominated diphenyl ethers across Asia.

    Science.gov (United States)

    Jaward, Foday M; Zhang, Gan; Nam, Jae Jak; Sweetman, Andrew J; Obbard, Jeffrey P; Kobara, Yuso; Jones, Kevin C

    2005-11-15

    Asia is of global importance economically, yet data on ambient persistent organic pollutant levels are still sparse for the region, despite international efforts under the Stockholm Convention to identify and reduce emissions. A large-scale passive air sampling survey was therefore conducted in Asia, specifically in China, Japan, South Korea, and Singapore. Polyurethane foam disks were deployed simultaneously at 77 sites, between Sept 21 and Nov 16, 2004, and analyzed for polychlorinated biphenyls (PCBs), organochlorine compounds (hexachlorobenzene (HCB), dichlorodiphenyltrichloroethanes (DDTs), chlordane), and polybrominated diphenyl ethers (PBDEs). The meteorological conditions prevailing in the region at this time facilitated the assessment of local/regional differences in atmospheric emissions, because large-scale advection effects due to monsoons or dust storms did not occur. Air concentrations estimated assuming an average sampler uptake rate of 3.5 m3/day ranged as follows (pg m(-3)): PCBs, 5-340; HCB, 10-460; DDTs, 0.4-1800; chlordanes, 1-660; PBDEs, < 0.13-340. South Korea and Singapore generally had regionally low concentrations. Elevated concentrations of PCBs, DDTs, and HCB occurred at sites in China, higher than reported in a similar recent sampling campaign in Europe. Chlordane was highest in samples from Japan (which also had elevated levels of PCBs and DDTs) and was also elevated in some Chinese locations. PBDE levels were generally low in the region.

  3. Leaching characteristics of polybrominated diphenyl ethers (PBDEs) from flame-retardant plastics.

    Science.gov (United States)

    Kim, Yong-Jin; Osako, Masahiro; Sakai, Shin-ichi

    2006-10-01

    To investigate the effect of leachant on the leachability of polybrominated diphenyl ethers (PBDEs), we determined the leaching concentrations of PBDEs from flame-retardant plastic samples (TV housings and raw materials before molding processing) that are regarded as a source of PBDEs in landfill sites. The leachants used were distilled water, 20% methanol solution, and dissolved humic solution (DHS) of 1000 mg/l based on organic carbon. The leaching test conditions were a liquid-to-solid ratio of 100:1, and a contact period of five days, with twice-daily agitation in a temperature-controlled room of 30 degrees C without pH or ionic strength control. The leaching concentrations of PBDEs increased with increased content, and were found to be remarkably enhanced when methanol and DHS were used instead of distilled water. The enhancement of leachability in the presence of the latter was attributed to the cosolvency effect, and complex formations between the PBDEs and dissolved humic matter (DHM). PBDE concentrations in the leachate obtained from the leaching test and an actual landfill site revealed a significant presence of congeners below heptabromodiphenyl ethers (H7BDEs), detected in the leachate of the actual landfill, while significant amounts of nonabromodiphenyl ethers (N9BDEs) and decabromodiphenyl ether (D10BDE) were detected in the leachate of the leaching test.

  4. Landfills as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

    Science.gov (United States)

    Weinberg, Ingo; Dreyer, Annekatrin; Ebinghaus, Ralf

    2011-02-01

    In order to investigate landfills as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two landfills (one active and one closed) and two reference sites using high volume air samplers. Contaminants were accumulated on glass fiber filters (particle phase) and PUF/XAD-2/PUF cartridges (gas phase), extracted by methyl-tert butyl ether/acetone (neutral PFCs), methanol (ionic PFCs) or hexane/acetone (PBDEs, musk fragrances), and detected by GC-MS (neutral PFCs, PBDEs, musk fragrances) or HPLC-MS/MS (ionic PFCs). Total concentrations ranged from 84 to 706 pg m -3 (volatile PFCs, gas phase), from fragrances, gas + particle phase) and from 1 to 11 pg m -3 (PBDEs, gas + particle phase). Observed sum concentrations of PFCs and synthetic musk fragrances and partly PBDE concentrations were elevated at landfill sites compared to corresponding reference sites. Concentrations determined at the active landfill were higher than those of the inactive landfill. Overall, landfills can be regarded as a source of synthetic musk fragrances, several PFCs and potentially of PBDEs to ambient air.

  5. Environmental pollution of polybrominated diphenyl ethers from industrial plants in China: a preliminary investigation.

    Science.gov (United States)

    Deng, Chao; Chen, Yuan; Li, Jinhui; Li, Ying; Li, Huafen

    2016-04-01

    Although numerous studies have shown the presence of polybrominated diphenyl ethers (PBDEs) in various environmental media, attention to their distribution in the environmental media surrounding industrial facilities is limited. In this study, eight PBDEs congeners (BDE-28, -47, -99, -100, -153, -154, -183, -209) were investigated in surface soils and water samples collected from commercial PBDE manufacturers, flame-retardant plastic modification plants and waste electrical and electronic equipment recycling facilities in China. Analysis of target compounds was performed using the model NCI GC-MS in SIM mode. The concentrations of ∑8PBDEs varied from 193.1 to 22,004.3 ng/L in water samples and from 1209.3 to 226,906 ng/g dry wt in surface soils, respectively. More severe PBDE contamination, when compared with previously reported data, was found in industrial areas in this study. This indicates that these industrial areas are highly polluted with PBDEs. BDE-209 was the predominant congener, accounting for more than 94% in this study, except for a 68.75% portion at one site. Our results show that PBDE manufacturing and flame-retardant plastic modification plants, easily overlooked by the public, are two primary PBDE pollution sources although they affect surrounding areas. Further research is needed, aimed at managing industrial PBDE emissions and eliminating environmental PBDE pollution, to investigate the material flows and environmental fates of PBDEs in all stages of the life cycle.

  6. AQUATOX coupled foodweb model for ecosystem risk assessment of Polybrominated diphenyl ethers (PBDEs) in lake ecosystems

    International Nuclear Information System (INIS)

    Zhang, Lulu; Liu, Jingling

    2014-01-01

    The AQUATOX model considers the direct toxic effects of chemicals and their indirect effects through foodwebs. For this study, the AQUATOX model was applied to evaluating the ecological risk of Polybrominated diphenyl ethers (PBDEs) in a highly anthropogenically disturbed lake-Baiyangdian Lake. Calibration and validation results indicated that the model can adequately describe the dynamics of 18 biological populations. Sensitivity analysis results suggested that the model is highly sensitive to temperature limitation. PBDEs risk estimate results demonstrate that estimated risk for natural ecosystems cannot be fully explained by single species toxicity data alone. The AQUATOX model could provide a good basis in ascertaining ecological protection levels of “chemicals of concern” for aquatic ecosystems. Therefore, AQUATOX can potentially be used to provide necessary information corresponding to early warning and rapid forecasting of pollutant transport and fate in the management of chemicals that put aquatic ecosystems at risk. - Highlights: • AQUATOX model incorporates direct toxic effects and indirect ecological effects. • Ecological risk of PBDEs was assessed by the AQUATOX model. • The model could help determine ecological threshold of “chemicals of concern”. - Capsule abstract: Application of the AQUATOX model to assess the direct and indirect ecological risk of PBDEs

  7. Polychlorinated biphenyls and polybrominated diphenyl ethers in the North American atmosphere

    International Nuclear Information System (INIS)

    Shen Li; Wania, Frank; Lei, Ying D.; Teixeira, Camilla; Muir, Derek C.G.; Xiao, Hang

    2006-01-01

    To assess the spatial concentration variability of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the atmosphere on a large continental scale, their annually integrated air concentrations were determined in 2000/2001 using XAD-based passive air samplers (PAS). The network included 40 stations in Canada, the United States, Mexico, Belize and Costa Rica, and covered 72 degrees of latitude and longitude. Total concentrations of PCB and PBDE congeners ranged from below the detection limit to 130 ng PAS -1 and 24 ng PAS -1 , respectively. PCBs displayed a large variation between urban, rural and remote sites, whereas PBDEs did not follow such a pattern. Open burning of 'Penta'-containing waste may have contributed to the PBDEs detected in the air samples from rural and remote areas. Air from the Canadian Arctic had a relatively higher percentage of lighter PCB congeners than air sampled in the tropical region, which is interpreted as evidence for global fractionation. - A continental passive air sampling network reveals atmospheric distribution patterns of two classes of industrial chemicals

  8. Evaluation of workers' exposure to methylene diphenyl diisocyanate (MDI) in an automobile manufacturing company, Iran.

    Science.gov (United States)

    Kakooei, Hossein; Shahtaheri, Seyed Jamaleddin; Karbasi, Hossein-Ali

    2006-01-01

    Evaluation of personal inhalation exposure to methylene diphenyl diisocyanate (MDI) among 39 employees, working in the window fixation and window glue processes in an automobile manufacturing company was performed. This study was conducted for both case and control groups. After sampling and sample preparation processes, MDI was determined with a UV-VIS spectrophotometer at 590 nm; the lung function was assessed with a digital spirometer, too. The average concentration of MDI in the window fixation, and window glue workplaces were 34.53 and 27.37 micro g/m3, respectively, which was lower than the threshold limit value (TLV) recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) (51 micro g/m3). Respiratory symptoms in the exposed group were significantly different compared to the unexposed group (p < .05). Lung capacities in the case group were lower than in the control group (p < .05). Therefore, MDI can be easily measured making it possible to evaluate the adverse effects caused by occupational exposure.

  9. Investigation on the interaction between bovine serum albumin and 2,2-diphenyl-1-picrylhydrazyl

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiangrong [Department of Chemistry, School of Basic Medicine, Xinxiang Medical University, Xinxiang, Henan 453003 (China); Chen, Dejun; Wang, Gongke [School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, 46 Jian-she Road, Mu Ye District, Xinxiang, Henan 453007 (China); Lu, Yan, E-mail: 1842457577@qq.com [School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, 46 Jian-she Road, Mu Ye District, Xinxiang, Henan 453007 (China)

    2014-12-15

    Albumin represents a very abundant and important circulating antioxidant in plasma. In this paper, the ability of bovine serum albumin (BSA) to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical has been investigated using UV–vis absorption spectra. The result shows that the antioxidant activity of BSA against DPPH radical is similar to glutathione and the value of IC{sub 50} is 5.153×10{sup −5} mol L{sup −1}. The interaction between BSA and DPPH has been investigated without or with the eight popular antioxidants (L-ascorbic acid, α-tocopherol, glutathione, melatonin, (+)-catechin hydrate, procyanidine B3, β-carotene and astaxanthin) by means of fluorescence spectroscopy and circular dichroism (CD) spectroscopy. The fluorescence experiments show that DPPH quenches the fluorescence intensity of BSA through a static mechanism. The quenching process of DPPH with BSA is easily affected by the eight antioxidants, however, they cannot change the quenching mechanism of DPPH with BSA. Additionally, as shown by synchronous fluorescence spectroscopy and CD, DPPH may induce conformational and microenvironmental changes of BSA. - Highlights: • The antioxidant activity of BSA against DPPH is similar to glutathione. • DPPH can quench the fluorescence of BSA through a static quenching. • One molecule of DPPH radical reduced by one molecule of BSA. • The eight antioxidants cannot change the quenching mechanism of DPPH with BSA. • The binding parameters are decreased by the introduction of the eight antioxidants.

  10. Characteristics of Polybrominated Diphenyl Ethers Released from Thermal Treatment and Open Burning of E-Waste.

    Science.gov (United States)

    Li, Ting-Yu; Zhou, Jun-Feng; Wu, Chen-Chou; Bao, Lian-Jun; Shi, Lei; Zeng, Eddy Y

    2018-04-17

    Primitive processing of e-waste potentially releases abundant organic contaminants to the environment, but the magnitudes and mechanisms remain to be adequately addressed. We conducted thermal treatment and open burning of typical e-wastes, that is, plastics and printed circuit boards. Emission factors of the sum of 39 polybrominated diphenyl ethers (∑ 39 PBDE) were 817-1.60 × 10 5 ng g -1 in thermal treatment and nondetected-9.14 × 10 4 ng g -1 , in open burning. Airborne particles (87%) were the main carriers of PBDEs, followed by residual ashes (13%) and gaseous constituents (0.3%), in thermal treatment, while they were 30%, 43% and 27% in open burning. The output-input mass ratios of ∑ 39 PBDE were 0.12-3.76 in thermal treatment and 0-0.16 in open burning. All PBDEs were largely affiliated with fine particles, with geometric mean diameters at 0.61-0.83 μm in thermal degradation and 0.57-1.16 μm in open burning from plastic casings, and 0.44-0.56 and nondetected- 0.55 μm, from printed circuit boards. Evaporation and reabsorption may be the main emission mechanisms for lightly brominated BDEs, but heavily brominated BDEs tend to affiliate with particles from heating or combustion. The different size distributions of particulate PBDEs in emission sources and adjacent air implicated a noteworthy redisposition process during atmospheric dispersal.

  11. Temporal variability of polybrominated diphenyl ether (PBDE) serum concentrations over one year.

    Science.gov (United States)

    Makey, Colleen M; McClean, Michael D; Sjödin, Andreas; Weinberg, Janice; Carignan, Courtney C; Webster, Thomas F

    2014-12-16

    Polybrominated diphenyl ethers (PBDEs) are flame retardant chemicals used in consumer products. They are common contaminants in human serum and associated with adverse health effects. Our objectives were to characterize PBDE serum concentrations in a New England cohort and assess temporal variability of this exposure biomarker over a one-year period. We collected three repeated measurements at six-month intervals from 52 office workers from the greater Boston (MA, United States) area from 2010 to 2011. The intraclass correlation coefficient for BDEs 28, 47, 99, 100, and 153 ranged from 0.87 to 0.99, indicating that a single serum measurement can reliably estimate exposure over a one-year period. This was true for both lipid adjusted and nonlipid adjusted concentrations. The kappa statistics, quantifying the level of agreement of categorical exposure classification, based on medians, tertiles, or quartiles ranged from 0.67 to 0.90. Some congeners showed nonsignificant increases from sampling round 1 (winter) to round 2 (summer) and significant decreases from round 2 to round 3 (winter). This study highlights the high reliability of a single serum PBDE measurement for use in human epidemiologic studies.

  12. Diphenyl diselenide attenuates oxidative stress and inflammatory parameters in ulcerative colitis: A comparison with ebselen.

    Science.gov (United States)

    Petronilho, Fabricia; Michels, Monique; Danielski, Lucinéia G; Goldim, Mariana Pereira; Florentino, Drielly; Vieira, Andriele; Mendonça, Mariana G; Tournier, Moema; Piacentini, Bárbara; Giustina, Amanda Della; Leffa, Daniela D; Pereira, Gregório W; Pereira, Volnei D; Rocha, João Batista Teixeira Da

    2016-09-01

    The aim of this study was to evaluate the effects of diphenyl diselenide (PhSe)2 and ebselen (EB) in ulcerative colitis (UC) induced by dextran sulfate sodium (DSS) in rats. The effects of (PhSe)2 and EB in rats submitted to DSS-induced colitis were determined by measurement of oxidative stress parameters, inflammatory response and bowel histopathological alterations. Animals developed moderate to severe neutrophil infiltration in histopathology assay in DSS rats and (PhSe)2 improved this response. Moreover, the treatment with (PhSe)2 decreased the oxidative damage in lipids and proteins, as well as reversed the superoxide dismutase (SOD) and catalase (CAT) levels in rats treated with DSS. EB was able only to reverse damage in lipids and the low levels of SOD in this animal model. The organoselenium compounds tested demonstrated an anti-inflammatory and antioxidant activity reducing the colon damage, being (PhSe)2 more effective than EB. Copyright © 2016 Elsevier GmbH. All rights reserved.

  13. An assessment of sources and pathways of human exposure to polybrominated diphenyl ethers in the United States.

    Science.gov (United States)

    Johnson-Restrepo, Boris; Kannan, Kurunthachalam

    2009-07-01

    Polybrominated diphenyl ethers (PBDEs) are ubiquitous in the indoor environment, owing to their use in consumer products ranging from electronics to mattresses, furniture, and carpets. People are exposed to PBDEs through inhalation of indoor air and ingestion, and dermal absorption of dust particles present in the air. In this study, concentrations of PBDEs were determined in indoor air and house dust collected from homes in Albany, New York, USA. Based on the measured concentrations of PBDEs in indoor air and dust, we estimated daily exposure dose (DED) of PBDEs. In addition, we used previously published PBDE concentrations reported for breast milk from Massachusetts, USA [Johnson-Restrepo, B., Addink, R., Wong, C., Arcaro, K., Kannan, K., 2007. Polybrominated diphenyl ethers and organochlorine pesticides in human breast milk from Massachusetts. USA. J. Environ. Monitor. 9, 1205-1212] and foodstuffs collected from Texas and Florida, USA [Schecter, A., Päpke, O., Harris, T.R., Tung, K.C., Musumba, A., Olson, J., Birnbaum, L., 2006. Polybrominated diphenyl ether (PBDE) levels in an expanded market basket survey of U.S. food and estimated PBDE dietary intake by age and sex. Environ. Health Perspect. 114, 1515-1520, Johnson-Restrepo, B., Kannan, K., Addink, R., Adams, D.H., 2005b. Polybrominated diphenyl ethers and polychlorinated biphenyls in a marine foodweb of coastal Florida. Environ. Sci. Technol. 39, 8243-8250], in an estimation of dietary exposure to PBDEs. The exposure assessment was performed for five age groups: infants (accounting for, on average, 56-77% of the total PBDE intake.

  14. Sphingosine 1-phosphate and cancer.

    Science.gov (United States)

    Pyne, Nigel J; El Buri, Ashref; Adams, David R; Pyne, Susan

    2017-09-15

    The bioactive lipid, sphingosine 1-phosphate (S1P) is produced by phosphorylation of sphingosine and this is catalysed by two sphingosine kinase isoforms (SK1 and SK2). Here we discuss structural functional aspects of SK1 (which is a dimeric quaternary enzyme) that relate to coordinated coupling of membrane association with phosphorylation of Ser225 in the 'so-called' R-loop, catalytic activity and protein-protein interactions (e.g. TRAF2, PP2A and G q ). S1P formed by SK1 at the plasma-membrane is released from cells via S1P transporters to act on S1P receptors to promote tumorigenesis. We discuss here an additional novel mechanism that can operate between cancer cells and fibroblasts and which involves the release of the S1P receptor, S1P 2 in exosomes from breast cancer cells that regulates ERK-1/2 signalling in fibroblasts. This novel mechanism of signalling might provide an explanation for the role of S1P 2 in promoting metastasis of cancer cells and which is dependent on the micro-environmental niche. Copyright © 2017. Published by Elsevier Ltd.

  15. Radiation doses from phosphate fertilizers

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The activity concentrations determined of 226 Ra, 232 Th and 40 K in nCi/kg P 2 O 5 for the five most important kinds of fertilizer as well as their percent share in the economy year 1973/74 in the FRG are compiled in a table. From these values, the consumption of 0.917 million tons P 2 O 5 and from an average annual fertilizer coverage of 68.3 kg/ha, one can calculate a distribution of 32 Ci 226 Ra, 1 Ci 232 Th and 543 Ci 40 K over the total agriculturally used area, in other words, a deposit of 2.4 μCi 226 Ra, 0.07 μCi 232 Th and 40.5 μCi 40 K per ha. Taking a pessimistic view, an external radiation exposure of 0.11 mrad/a was calculated for gonads and bone marrow. If the total accumulation of 226 Ra (38% of the radiation exposure) from phosphate fertilizers from the ground during the last 80 years is assumed, then there is an exposure of 1.7 mrad/a for individual members of the population and 2.0 mrad/a for those occupied in agriculture. (HP/LH) [de

  16. Natural radioactivity in phosphate fertilizers

    International Nuclear Information System (INIS)

    Arndt, J.; Aurand, K.; Ruehle, H.; Schmier, H.; Wolter, R.

    1974-12-01

    The activity concentrations determined of 226 Ra, 232 Th and 40 K in nCi/kg P 2 O 5 for the five most important kinds of fertilizer as well as their percent share in the economy year 1973/74 in the FRG are compiled in a table. From these values, the consumption of 0.917 million tons P 2 O 5 and from an average annual fertilizer covering of 68.3 kg/ha, one can calculate a distribution of 32 Ci 226 Ra, 1 Ci 232 Th and 543 Ci 40 K over the total agriculturally used area, in other words a deposit of 2.4 μCi 226 Ra, 0.07 μCi 232 Th and 40.5 μCi 40 K per ha. Taking a pessimistic view, an external radiation exposure of 0.11 mrad/a was calculated for gonads and bone marrow. If the total accumulation of 226 Ra (38% of the radiation exposure) from phosphate fertilizers from the ground during the last 80 years is assumed, then there is an exposure of 1.7 mrad/a for individual members of the population and 2.0 mrad/a for those occupied in agriculture. (HP/LH) [de

  17. The extraction of trace amounts of gold from different aqueous mineral acid solutions by diphenyl-2-pyridylmethane dissolved in chloroform

    International Nuclear Information System (INIS)

    Iqbal, M.; Ejaz, M.; Chaudhri, S.A.; Zamiruddin

    1978-01-01

    Diphenyl-2-pyridylmethane, a high-molecular-weight substituted pyridine has been examined. Its behaviour is similar to that of amines in that it forms salts with mineral acids. The acid ionization constant (pKsub(BHsup(+)) is 4.4+-0.06 at 25 deg C. A study of the partition behaviour of trace amounts of gold between mineral acid solutions and 0.1 M diphenyl-2-pyridylmethane dissolved in chloroform indicates that the metal can be quantitatively extracted from dilute mineral acid solutions and also from concentrated hydrochloric acid media in a single extraction. Common anions have little effect on extraction in concentrations up to 1 M. Separation factors of a number of metal ions relative to gold are reported for three mineral acid systems. Gold has been estimated in some synthetic samples using a neutron-activation technique by prior extraction with 0.1 M solution of diphenyl-2-pyridylmethane dissolved in chloroform. Distribution of the test elements between aqueous and organic phase was followed radiometrically. The solutions (usually 1 cm 3 ) were shaken in stoppered vials for 5 minutes using a mechanical shaker. After separation of the layers, 500 μl of each phase were taken for radiochemical analysis. The standard deviation did not exceed 1%. (T.G.)

  18. Hemodialysis for near-fatal sodium phosphate toxicity in a child receiving sodium phosphate enemas.

    Science.gov (United States)

    Becknell, Brian; Smoyer, William E; O'Brien, Nicole F

    2014-11-01

    This study aimed to demonstrate the importance of considering hemodialysis as a treatment option in the management of sodium phosphate toxicity. This is a case report of a 4-year-old who presented to the emergency department with shock, decreased mental status, seizures, and tetany due to sodium phosphate toxicity from sodium phosphate enemas. Traditional management of hyperphosphatemia with aggressive hydration and diuretics was insufficient to reverse the hemodynamic and neurological abnormalities in this child. This is the first report of the use of hemodialysis in a child without preexisting renal failure for the successful management of near-fatal sodium phosphate toxicity. Hemodialysis can safely be used as an adjunctive therapy in sodium phosphate toxicity to rapidly reduce serum phosphate levels and increase serum calcium levels in children not responding to conventional management.

  19. Opioid system contribution to the antidepressant-like action of m-trifluoromethyl-diphenyl diselenide in mice: A compound devoid of tolerance and withdrawal syndrome.

    Science.gov (United States)

    Rosa, Suzan G; Pesarico, Ana P; Tagliapietra, Carolina F; da Luz, Sônia Ca; Nogueira, Cristina W

    2017-09-01

    Animal and clinical researches indicate that the opioid system exerts a crucial role in the etiology of mood disorders and is a target for intervention in depression treatment. This study investigated the contribution of the opioid system to the antidepressant-like action of acute or repeated m-trifluoromethyl-diphenyl diselenide administration to Swiss mice. m-Trifluoromethyl-diphenyl diselenide (50 mg/kg, intragastric) produced an antidepressant-like action in the forced swimming test from 30 min to 24 h after treatment. This effect was blocked by the µ and δ-opioid receptor antagonists, naloxonazine (10 mg/kg, intraperitoneally) and naltrindole (3 mg/kg, intraperitoneally), and it was potentiated by a κ-opioid receptor antagonist, norbinaltrophimine (1 mg/kg, subcutaneously ). Combined treatment with subeffective doses of m-trifluoromethyl-diphenyl diselenide (10 mg/kg, intragastric) and morphine (1 mg/kg, subcutaneously) resulted in a synergistic antidepressant-like effect. The opioid system contribution to the m-trifluoromethyl-diphenyl diselenide antidepressant-like action was also demonstrated in the modified tail suspension test, decreasing mouse immobility and swinging time and increasing curling time, results similar to those observed using morphine, a positive control. Treatment with m-trifluoromethyl-diphenyl diselenide induced neither tolerance to the antidepressant-like action nor physical signs of withdrawal, which could be associated with the fact that m-trifluoromethyl-diphenyl diselenide did not change the mouse cortical and hippocampal glutamate uptake and release. m-Trifluoromethyl-diphenyl diselenide treatments altered neither locomotor nor toxicological parameters in mice. These findings demonstrate that m-trifluoromethyl-diphenyl diselenide elicited an antidepressant-like action by direct or indirect μ and δ-opioid receptor activation and the κ-opioid receptor blockade, without inducing tolerance, physical signs of withdrawal and

  20. Generation of Resistance to the Diphenyl Ether Herbicide, Oxyfluorfen, via Expression of the Bacillus subtilis Protoporphyrinogen Oxidase Gene in Transgenic Tobacco Plants.

    Science.gov (United States)

    Choi, K W; Han, O; Lee, H J; Yun, Y C; Moon, Y H; Kim, M; Kuk, Y I; Han, S U; Guh, J O

    1998-01-01

    In an effort to develop transgenic plants resistant to diphenyl ether herbicides, we introduced the protoporphyrinogen oxidase (EC 1.3.3.4) gene of Bacillus subtilis into tobacco plants. The results from a Northern analysis and leaf disc assay indicate that the expression of the B. subtilis protoporphyrinogen oxidase gene under the cauliflower mosaic virus 35S promoter generated resistance to the diphenyl ether herbicide, oxyfluorfen, in transgenic tobacco plants.

  1. Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

    OpenAIRE

    Lílian Estrela Borges Baldotto; Marihus Altoé Baldotto; Fábio Lopes Olivares; Adriane Nunes de Souza

    2014-01-01

    Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i) to select and characterize diazotrophs abl...

  2. Uranium recovery from phosphate rocks concentrated

    International Nuclear Information System (INIS)

    Azevedo, M.F. de.

    1986-01-01

    The reserves, geological data, chemical data and technical flowsheet from COPEBRAS and Goiasfertil ores are described, including the process of mining ore concentration. Samples of Goiasfertil ores are analysed by gravimetric analysis, for phosphate, and spectrofluorimetry for uranium. (author)

  3. Hanford phosphate precipitation filtration process evaluation

    International Nuclear Information System (INIS)

    Walker, B.W.; McCabe, D.J.

    1997-01-01

    The purpose of this filter study was to evaluate cross-flow filtration as effective solid-liquid separation technology for treating Hanford wastes, outline operating conditions for equipment, examine the expected filter flow rates, and determine proper cleaning. A proposed Hanford waste pre-treatment process uses sodium hydroxide at high temperature to remove aluminum from sludge. This process also dissolves phosphates. Upon cooling to 40 degrees centigrade the phosphates form a Na7(PO4)2F9H2O precipitate which must be removed prior to further treatment. Filter studies were conducted with a phosphate slurry simulant to evaluate whether 0.5 micron cross-flow sintered metal Mott filters can separate the phosphate precipitate from the wash solutions. The simulant was recirculated through the filters at room temperature and filtration performance data was collected

  4. short communication agronomic effectiveness of novel phosphate

    African Journals Online (AJOL)

    igneous Dorowa (Zimbabwe) phosphate rock was investigated in a greenhouse ... are higher than the levels considered desirable for acidulation was selected based on proportions ... The analysis for dry matter yield of and P uptake by maize ...

  5. Phosphate coating on stainless steel 304 sensitized

    International Nuclear Information System (INIS)

    Cruz V, J. P.; Vite T, J.; Castillo S, M.; Vite T, M.

    2009-01-01

    The stainless steel 304 can be sensitized when welding processes are applied, that causes the precipitation of chromium carbide in the grain limits, being promoted in this way the formation of galvanic cells and consequently the corrosion process. Using a phosphate coating is possible to retard the physiochemical damages that can to happen in the corrosion process. The stainless steel 304 substrate sensitized it is phosphate to base of Zn-Mn, in a immersion cell very hot. During the process was considered optimization values, for the characterization equipment of X-rays diffraction and scanning electron microscopy was used. The XRD technique confirmed the presence of the phases of manganese phosphate, zinc phosphate, as well as the phase of the stainless steel 304. When increasing the temperature from 60 to 90 C in the immersion process a homogeneous coating is obtained. (Author)

  6. Issues of natural radioactivity in phosphates

    International Nuclear Information System (INIS)

    Schnug, E.; Haneklaus, S.; Schnier, C.; Scholten, L.C.

    1996-01-01

    The fertilization of phosphorus (P) fertilizers is essential in agricultural production, but phosphates contain in dependence on their origin different amounts of trace elements. The problem of cadmium (Cd) loads and other heavy metals is well known. However, only a limited number of investigations examined the contamination of phosphates with the two heaviest metals, uranium (U) and thorium (Th), which are radioactive. Also potassium (K) is lightly radioactive. Measurements are done n the radioactivity content of phosphates, P fertilizers and soils. The radiation doses to workers and public as well as possible contamination of soils from phosphate rock or fertilizer caused by these elements or their daughter products is of interest with regard to radiation protection. The use of P fertilizers is necessary for a sustainable agriculture, but it involves radioactive contamination of soils. The consequences of the use of P fertilizers is discussed, also with regard to existing and proposed legislation. 11 refs., 2 figs., 7 tabs

  7. Geochemistry and mineralogy of Ogun phosphate rock

    African Journals Online (AJOL)

    user

    m deep) within the same location. The pellets ... diffracted rays are collected by a detector and the information relayed to a ... Ogun phosphate deposits were formed in shallow marine ... process thus confirming the earlier work done by Jones.

  8. Rock phosphate solubilization by the ectomycorrhizal fungus ...

    African Journals Online (AJOL)

    SAM

    2014-06-18

    Jun 18, 2014 ... phosphate solubilization is accompanied by acid production. Thus, the evidence ..... of organic acids. (Khan et al., 2010) such as acetate, lactate, oxalate, ... (2014) also observed that oxalic acid was secreted by L. fraterna to ...

  9. Thermal stability of phosphate coatings on steel

    Czech Academy of Sciences Publication Activity Database

    Pokorný, P.; Szelag, P.; Novák, M.; Mastný, L.; Brožek, Vlastimil

    2015-01-01

    Roč. 54, č. 3 (2015), s. 489-492 ISSN 0543-5846 Institutional support: RVO:61389021 Keywords : Steel * phosphates * coatings * structure Subject RIV: CA - Inorganic Chemistry Impact factor: 0.959, year: 2014

  10. Corrosion inhibition by lithium zinc phosphate pigment

    International Nuclear Information System (INIS)

    Alibakhshi, E.; Ghasemi, E.; Mahdavian, M.

    2013-01-01

    Highlights: •Synthesis of lithium zinc phosphate (LZP) by chemical co-precipitation method. •Corrosion inhibition activity of pigments compare with zinc phosphate (ZP). •LZP showed superior corrosion inhibition effect in EIS measurements. •Evaluation of adhesion strength and dispersion stability. -- Abstract: Lithium zinc phosphate (LZP) has been synthesized through a co-precipitation process and characterized by XRD and IR spectroscopy. The inhibitive performances of this pigment for corrosion of mild steel have been discussed in comparison with the zinc phosphate (ZP) in the pigment extract solution by means of EIS and in the epoxy coating by means of salt spray. The EIS and salt spray results revealed the superior corrosion inhibitive effect of LZP compared to ZP. Moreover, adhesion strength and dispersion stability of the pigmented epoxy coating showed the advantage of LZP compared to ZP

  11. Synthesis and characterization of porous calcium phosphate

    International Nuclear Information System (INIS)

    Granados C, F.; Serrano G, J.; Bonifacio M, J.

    2007-01-01

    The porous calcium phosphate was prepared by the continuous precipitation method using Ca(NO 3 ) 2 .4H 2 O and NH 4 H 2 PO 4 salts. The synthesized material was structurally and superficially characterized using the XRD, BET, IR TGA and SEM techniques. The obtained inorganic material was identified as calcium phosphate that presents a great specific area for what can be efficiently used as adsorbent material for adsorption studies in the radioactive wastes treatment present in aqueous solution. (Author)

  12. Removal of organic wastes containing tributyl phosphate

    International Nuclear Information System (INIS)

    Drobnik, S.

    TBP in dodecane and kerosene is one of the waste solutions from the reprocessing of spent nuclear fuels by the Purex process. The following methods were investigated for removing the organic solvents: adsorption on suitable solids, extraction, reaction with neutral salts, and saponification with acids or alkalis. Results showed that the best method of TBP removal is saponification with alkali hydroxides, either with dibutyl phosphate or with ortho-phosphate

  13. Kinetics of strontium sorption in calcium phosphate

    International Nuclear Information System (INIS)

    Bacic, S.; Komarov, V.F.; Vukovic, Z.

    1989-01-01

    Kinetics of strontium sorption by highly dispersed solids: tricalcium phosphate (Ca 3 (PO 4 ) 2 , TCP) and hydroxyapatite (Ca 5 (PO 4 ) 3 )H, HAP) were investigated. Analysis of sorption data was made taking into consideration composition and morphology of ultra micro particles. Conclusion is that the isomorphous strontium impurity is structurally sensitive element for calcium phosphate. It was determined that the beginning of strontium desorption corresponds to the beginning of transformation of the TCP - HAP (author)

  14. Phosphate transporter mediated lipid accumulation in Saccharomyces cerevisiae under phosphate starvation conditions.

    Science.gov (United States)

    James, Antoni W; Nachiappan, Vasanthi

    2014-01-01

    In the current study, when phosphate transporters pho88 and pho86 were knocked out they resulted in significant accumulation (84% and 43%) of triacylglycerol (TAG) during phosphate starvation. However in the presence of phosphate, TAG accumulation was only around 45% in both pho88 and pho86 mutant cells. These observations were confirmed by radio-labeling, fluorescent microscope and RT-PCR studies. The TAG synthesizing genes encoding for acyltransferases namely LRO1 and DGA1 were up regulated. This is the first report for accumulation of TAG in pho88Δ and pho86Δ cells under phosphate starvation conditions. Copyright © 2013. Published by Elsevier Ltd.

  15. Phosphate rock costs, prices and resources interaction.

    Science.gov (United States)

    Mew, M C

    2016-01-15

    This article gives the author's views and opinions as someone who has spent his working life analyzing the international phosphate sector as an independent consultant. His career spanned two price hike events in the mid-1970's and in 2008, both of which sparked considerable popular and academic interest concerning adequacy of phosphate rock resources, the impact of rising mining costs and the ability of mankind to feed future populations. An analysis of phosphate rock production costs derived from two major industry studies performed in 1983 and 2013 shows that in nominal terms, global average cash production costs increased by 27% to $38 per tonne fob mine in the 30 year period. In real terms, the global average cost of production has fallen. Despite the lack of upward pressure from increasing costs, phosphate rock market prices have shown two major spikes in the 30 years to 2013, with periods of less volatility in between. These price spike events can be seen to be related to the escalating investment cost required by new mine capacity, and as such can be expected to be repeated in future. As such, phosphate rock price volatility is likely to have more impact on food prices than rising phosphate rock production costs. However, as mining costs rise, recycling of P will also become increasingly driven by economics rather than legislation. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Sphingosine 1-Phosphate and Atherosclerosis

    Science.gov (United States)

    Yatomi, Yutaka

    2018-01-01

    Sphingosine 1-phosphate (S1P) is a potent lipid mediator that works on five kinds of S1P receptors located on the cell membrane. In the circulation, S1P is distributed to HDL, followed by albumin. Since S1P and HDL share several bioactivities, S1P is believed to be responsible for the pleiotropic effects of HDL. Plasma S1P levels are reportedly lower in subjects with coronary artery disease, suggesting that S1P might be deeply involved in the pathogenesis of atherosclerosis. In basic experiments, however, S1P appears to possess both pro-atherosclerotic and anti-atherosclerotic properties; for example, S1P possesses anti-apoptosis, anti-inflammation, and vaso-relaxation properties and maintains the barrier function of endothelial cells, while S1P also promotes the egress and activation of lymphocytes and exhibits pro-thrombotic properties. Recently, the mechanism for the biased distribution of S1P on HDL has been elucidated; apolipoprotein M (apoM) carries S1P on HDL. ApoM is also a modulator of S1P, and the metabolism of apoM-containing lipoproteins largely affects the plasma S1P level. Moreover, apoM modulates the biological properties of S1P. S1P bound to albumin exerts both beneficial and harmful effects in the pathogenesis of atherosclerosis, while S1P bound to apoM strengthens anti-atherosclerotic properties and might weaken the pro-atherosclerotic properties of S1P. Although the detailed mechanisms remain to be elucidated, apoM and S1P might be novel targets for the alleviation of atherosclerotic diseases in the future. PMID:28724841

  17. Distribution and accumulation of polybrominated diphenyl ethers (PBDEs) in Hong Kong mangrove sediments.

    Science.gov (United States)

    Zhu, Haowen; Wang, Ying; Wang, Xiaowei; Luan, Tiangang; Tam, Nora F Y

    2014-01-15

    Polybrominated diphenyl ethers (PBDEs) have been used extensively as brominated flame retardants in various polymers, and have become serious environmental contaminants, particularly in coastal sediments. Mangrove wetlands are important coastal ecosystems in tropical and subtropical regions, and mangrove sediments are often the pollutant sinks due to their close proximity with human activities. In Hong Kong, sediment samples collected from five mangrove swamps were found to be contaminated with PBDEs and the eight measured BDE congeners, including BDE-28, -47, -99, -100, -153, -154, -183 and -209 were detected in all mangrove sediments, indicating that these pollutants were widespread in Hong Kong mangrove wetlands. Among the five swamps, relatively high concentrations of PBDEs were recorded in Mai Po mangrove swamp in the northwestern Hong Kong, which is part of the RAMSAR site but is severely influenced by the pollution from the Pearl River Delta. The depth profile of PBDEs in sediment cores collected from Mai Po also showed the inputs of PBDEs in this mangrove swamp increased year by year. In all sediments, the concentrations of BDE-209 were 1-2 orders of magnitude higher than the other congeners in the same sediment. The concentrations of BDE-209 and ∑PBDEs (defined as the sum of seven targeted BDE congeners except BDE-209) ranged from 1.53 to 75.9 ng g(-1) and from 0.57 to 14.4 ng g(-1), respectively. Among the targeted BDE congeners except BDE-209, slightly different composition was recorded among samples collected from different locations, with BDE-153 and -183 being the pre-dominated congeners. In all mangrove swamps, except Tai O in the southwest of Hong Kong, ∑PBDEs concentrations showed a common trend of landward>seaward>mudflat. The concentrations of ∑PBDEs were significantly correlated with total organic matter (TOM) content in sediments but not with the sediment particle sizes in each mangrove swamp. © 2013.

  18. Reductive debromination of polybrominated diphenyl ethers in anaerobic sediment and a biomimetic system.

    Science.gov (United States)

    Tokarz, John A; Ahn, Mi-Youn; Leng, June; Filley, Timothy R; Nies, Loring

    2008-02-15

    Because of the bioaccumulation of penta- and tetrapolybrominated diphenyl ether (PBDE) flame retardants in biota,the environmental biotransformation of decabromodiphenyl ether (BDE-209) is of interest. BDE-209 accounts for more than 80% by mass of PBDE production and is the dominant PBDE in sediments. Most sediments are anaerobic and reports of microbial reductive dehalogenation of hydrophobic persistent organohalogen pollutants are numerous. Reductive debromination of BDE-209 in the environment could provide a significant source of lesser-brominated PBDEs to biota. Moreover, a recent study showed that BDE-209 debrominates in sewage sludge, and another demonstrated that some halorespiring bacteria will debrominate BDE-209. To determine whether reductive debromination of BDE-209 occurs in sediments, parallel experiments were conducted using anaerobic sediment microcosms and a cosolvent-enhanced biomimetic system. In the biomimetic system, reductive debromination occurred at rates corresponding to bromine substitution levels with a BDE-209 half-life of only 18 s compared with a halflife of almost 60 days for 2,2',4,4'-tetrabromodiphenyl ether. In sediment, the measured debromination half-life of BDE-209 was well over a decade and was in good agreement with the predicted value obtained from the biomimetic experiment. Product congeners were predominantly double para-substituted. BDE-209 debrominated in sediment with a corresponding increase in nona-, octa-, hepta-, and hexa-PBDEs. Nine new PBDE congeners appeared in sediment from reductive debromination. Given the very large BDE-209 burden already in sediments globally, it is important to determine whether this transformation is a significant source of lesser-brominated PBDEs to the environment.

  19. Effects of polybrominated diphenyl ethers on steroidogenesis in rat Leydig cells.

    Science.gov (United States)

    Wang, Kai-Lee; Hsia, Shih-Min; Mao, I-Fang; Chen, Mei-Lien; Wang, Shyi-Wu; Wang, Paulus S

    2011-08-01

    Polybrominated diphenyl ethers (PBDEs) are brominated flame retardants that have been defined as major environmental pollutants. While previous studies have found that PBDEs may enhance the levels of sex-steroid hormones, their effects on testosterone secretion from rat Leydig cells are unclear. This study investigated the effects and mechanisms of PBDE-710, a mixture of tetra- and penta-PBDEs, on testosterone biosynthesis in rat Leydig cells. Leydig cells from adult male rats were challenged with different concentrations of PBDE-710 (0.5-15 ng/ml) to evaluate the effects on testosterone steroidogenesis. Concentrations of testosterone and of cAMP and pregnenolone in medium were measured by radioimmunoassay (RIA) and by enzyme-linked immunosorbent assay, respectively. Nuclear translocation of protein kinase A α (PKAα) was determined by immunofluorence assay and western blot assay, and the mRNA expression of steroidogenic acute regulatory protein (StAR) was analyzed by quantitative real-time polymerase chain reaction. In this in vitro study, PBDE-710 (5 or 15 ng/ml) increased basal testosterone secretion and cAMP production by 3- and 2-fold, respectively. The stimulatory effect was abolished by adenylyl cyclase inhibitor. Enzyme activity of CYP11A1, as determined by the pregnenolone concentration, was stimulated by PBDE-710 treatment. Furthermore, nuclear translocation of PKAα was increased by 20% and StAR gene expression was elevated by 4-fold after PBDE-710 treatment. These results suggest that low concentrations of PBDE-710 could stimulate testosterone secretion by acting directly on Leydig cells to activate the cAMP pathway and increase expression of StAR.

  20. Disruption of type 2 iodothyronine deiodinase activity in cultured human glial cells by polybrominated diphenyl ethers.

    Science.gov (United States)

    Roberts, Simon C; Bianco, Antonio C; Stapleton, Heather M

    2015-06-15

    Polybrominated diphenyl ether (PBDE) flame retardants are endocrine disruptors and suspected neurodevelopmental toxicants. While the direct mechanisms of neurodevelopmental toxicity have not been fully elucidated, it is conceivable that alterations in thyroid hormone levels in the developing brain may contribute to these effects. Cells within the brain locally convert thyroxine (T4) to the biologically active triiodothyronine (T3) through the action of the selenodeiodinase type 2 iodothyronine deiodinase (DIO2). Previous studies have demonstrated that PBDEs can alter hepatic deiodinase activity both in vitro and in vivo; however, the effects of PBDEs on the deiodinase isoforms expressed in the brain are not well understood. Here, we studied the effects of several individual PBDEs and hydroxylated metabolites (OH-BDEs) on DIO2 activity in astrocytes, a specialized glial cell responsible for production of more than 50% of the T3 required by the brain. Primary human astrocytes and H4 glioma cells were exposed to individual PBDEs or OH-BDEs at concentrations up to 5 μM. BDE-99 decreased DIO2 activity by 50% in primary astrocyte cells and by up to 80% in the H4 cells at doses of ≥500 nM. 3-OH-BDE-47, 6-OH-BDE-47, and 5'-OH-BDE-99 also decreased DIO2 activity in cultured H4 glioma cells by 45-80% at doses of approximately 1-5 μM. Multiple mechanisms appear to contribute to the decreased DIO2 activity, including weakened expression of DIO2 mRNA, competitive inhibition of DIO2, and enhanced post-translational degradation of DIO2. We conclude that decreases in DIO2 activity caused by exposure to PBDEs may play a role in the neurodevelopmental deficits caused by these toxicants.

  1. Debromination of polybrominated diphenyl ethers by Ni/Fe bimetallic nanoparticles: Influencing factors, kinetics, and mechanism

    International Nuclear Information System (INIS)

    Fang Zhanqiang; Qiu Xinhong; Chen Jinhong; Qiu Xiuqi

    2011-01-01

    Polybrominated diphenyl ethers have been identified as a new class of organic pollutants with ecological risk due to their toxicity, bioaccumulation, and global distribution. Proper remediation technologies are needed to remove them from the environment. In this paper, Ni/Fe bimetallic nanoparticles were synthesized by chemical deposition and used to degrade decabromodiphenyl ether (BDE209). The characteristics of Ni/Fe nanoparticles were analyzed by transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, and Brunnaer-Emmett-Teller surface area analysis. Ni/Fe bimetallic nanoparticles with diameters in the order of 20-50 nm could effectively degrade BDE209 in the solvent (tetrahydrofuran/water). Influence factors, such as Ni/Fe nanoparticle dosage, initial BDE209 concentration, and Ni loading, on the removal of BDE209 were studied. The results indicated that the degradation of BDE209 followed pseudo-first-order kinetics, and the degradation rate of BDE209 increased with increasing the amount of nano Ni/Fe particles, Ni/Fe ratio, and decreasing the initial concentration of BDE209. Through analyzed the mass balance of the BDE209 removal, degradation was the main process of BDE209 removal. The mechanism of debromination was deduced by analyzing the reaction products using gas chromatography-mass spectrometry, the bromide ion in the solution and varying the solvent conditions. Stepwise hydrogen reduction is the main process of debromination, and the hydrion play an important role in the reaction. Moreover, the experiment of long term performance and leaching of Ni were also carried out to test the stability and durability of Ni/Fe nanoparticles in BDE209 degradation.

  2. Formation of hydroxylated polybrominated diphenyl ethers from laccase-catalyzed oxidation of bromophenols.

    Science.gov (United States)

    Lin, Kunde; Zhou, Shiyang; Chen, Xi; Ding, Jiafeng; Kong, Xiaoyan; Gan, Jay

    2015-11-01

    Hydroxylated polybrominated diphenyl ethers (OH-PBDEs) have been frequently found in the marine biosphere as emerging organic contaminants. Studies to date have suggested that OH-PBDEs in marine biota are natural products. However, the mechanisms leading to the biogenesis of OH-PBDEs are still far from clear. In this study, using a laccase isolated from Trametes versicolor as the model enzyme, we explored the formation of OH-PBDEs from the laccase-catalyzed oxidation of simple bromophenols (e.g., 2,4-DBP and 2,4,6-TBP). Experiments under ambient conditions clearly showed that OH-PBDEs were produced from 2,4-DBP and 2,4,6-TBP in presence of laccase. Polybrominated compounds 2'-OH-BDE68, 2,2'-diOH-BB80, and 1,3,8-TrBDD were identified as the products from 2,4-DBP, and 2'-OH-BDE121 and 4'-OH-BDE121 from 2,4,6-TBP. The production of OH-PBDEs was likely a result of the coupling of bromophenoxy radicals, generated from the laccase-catalyzed oxidation of 2,4-DBP or 2,4,6-TBP. The transformation of bromophenols by laccase was pH-dependant, and was also influenced by enzymatic activity. In view of the abundance of 2,4-DBP and 2,4,6-TBP and the phylogenetic distribution of laccases in the environment, laccase-catalyzed conversion of bromophenols may be potentially an important route for the natural biosynthesis of OH-PBDEs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Adsorption and sequential degradation of polybrominated diphenyl ethers with zerovalent iron

    International Nuclear Information System (INIS)

    Peng, Yu-Huei; Chen, Mei-kuei; Shih, Yang-hsin

    2013-01-01

    Highlights: • A detailed analysis in the removal mechanism of PBDEs by MZVI was conducted. • 13% of DBDE and 24% of BDE-3 in average were adsorbed on the surface of MZVI. • The adsorbed PBDEs on MZVI were also confirmed by FTIR spectroscopy. • MZVI continues the reductive debromination of PBDEs even after one month. •MZVI has great longevity to adsorb and degrade PBDE in the environment. -- Abstract: The widely used flame retardants, polybrominated diphenyl ethers (PBDEs), have been regulated owing to their persistence and toxicity. However, the high and increasing accumulation amount of PBDEs in the environment raises a big concern for public safety. In this study, the removal processes of decabromodiphenyl ether (BDE-209) and monobromodiphenyl ether (BDE-3) with microscale zerovalent iron (MZVI) were investigated to get better understandings for the removal mechanism based upon adsorption and degradation. The removal kinetics of both compounds was analyzed and revealed two-step kinetics: a fast removal step at the beginning of the reaction and a follow-up slow removal step. By-products generated during the entire process followed a stepwise sequence. The content of brominated compounds on the surface of MZVI was measured. About 10–20% of BDE-209 and 15–30% of BDE-3 were adsorbed on MZVI. The adsorption of BDE-209 and BDE-3 on MZVI was confirmed through the Fourier transform infrared spectroscopy. Surface adsorption of PBDEs on MZVI dominates the removal mechanism in the beginning and further debromination with MZVI was found. Finally, about 70% of BDE-209 and 60% of BDE-3 was degraded by MZVI within about one month. Our findings provide evidences for understanding the removal mechanism of PBDEs with MZVI and its great longevity on the PBDE degradation, which can facilitate the remediation design

  4. Metabolism of polybrominated diphenyl ethers and tetrabromobisphenol A by fish liver subcellular fractions in vitro.

    Science.gov (United States)

    Shen, Mengnan; Cheng, Jie; Wu, Ruohan; Zhang, Shenghu; Mao, Liang; Gao, Shixiang

    2012-06-15

    Polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) are two major flame retardants that accumulate in fish tissues and are potentially toxic. Their debrominated and oxidated derivatives were also reported in fish tissues although the sources of theses derivatives were unidentified. Our study was to determine whether PBDEs and TBBPA could be metabolized by fish liver subcellular fractions in vitro and to identify what types of metabolites were formed. Liver microsomes and S9 fractions of crucian carp (Carassius auratus) were exposed to 4,4'-dibromodiphenyl ether (BDE 15), 2,2',4,4'-tetrabromodiphenyl ether (BDE 47) or TBBPA solutions for 4h. Exposure of liver subcellular fractions to BDE 15 resulted in the formation of bromophenol and two monohydroxylated dibromodiphenyl ether metabolites. Neither in microsomes nor in S9 studies has revealed the presence of hydroxylated metabolites with BDE 47 exposure which indicated that the oxidation reactions in vitro were hindered by the increased number of bromine substituents on the PBDEs. TBBPA underwent an oxidative cleavage near the central carbon of the molecule, which led to the production of 2,6-dibromo-4-isopropyl-phenol and three unidentified metabolites. Another metabolite of TBBPA characterized as a hexa-brominated compound with three aromatic rings was also found in the liver subcellular fractions. These results suggest that the biotransformation of BDE 15 and TBBPA in fish liver is mediated by cytochrome P450 (CYP450) enzymes, as revealed by the formation of hydroxylated metabolites and oxidative bond cleavage products. Moreover, further studies on the identification of specific CYP450 isozymes involved in the biotransformation revealed that CYP1A was the major enzyme responsible for the biotransformation of BDE 15 and TBBPA in fish liver subcellular fractions and CYP3A4 also played a major role in metabolism of TBBPA. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Concentrations of Polybrominated Diphenyl Ethers (PBDEs) and 2,4,6-Tribromophenol in Human Placental Tissues

    Science.gov (United States)

    Leonetti, Christopher; Butt, Craig M.; Hoffman, Kate; Miranda, Marie Lynn; Stapleton, Heather M.

    2015-01-01

    Legacy environmental contaminants such as polybrominated diphenyl ethers (PBDEs) are widely detected in human tissues. However, few studies have measured PBDEs in placental tissues, and there are no reported measurements of 2,4,6-tribromophenol (2,4,6-TBP) in placental tissues. Measurements of these contaminants are important for understanding potential fetal exposures, as these compounds have been shown to alter thyroid hormone regulation in vitro and in vivo. In this study, we measured a suite of PBDEs and 2,4,6-TBP in 102 human placental tissues collected between 2010–2011 in Durham County, North Carolina, USA. The most abundant PBDE congener detected was BDE-47, with a mean concentration of 5.09 ng/g lipid (range: 0.12–141 ng/g lipid; detection frequency 91%); however, 2,4,6-TBP was ubiquitously detected and present at higher concentrations with a mean concentration of 15.4 ng/g lipid (range:1.31–316 ng/g lipid; detection frequency 100%). BDE-209 was also detected in more than 50% of the samples, and was significantly associated with 2,4,6-TBP in placental tissues, suggesting they may have a similar source, or that 2,4,6-TBP may be a degradation product of BDE-209. Interestingly, BDE-209 and 2,4,6-TBP were negatively associated with age (rs=−0.16; p=0.10 and rs=−0.17; p=0.08, respectively). The results of this work indicate that PBDEs and 2,4,6-TBP bioaccumulate in human placenta tissue and likely contribute to prenatal exposures to these environmental contaminants. Future studies are needed to determine if these joint exposures are associated with any adverse health measures in infants and children. PMID:26700418

  6. Prenatal exposure to polybrominated diphenyl ethers and child attention problems at 3–7 years

    Science.gov (United States)

    Cowell, Whitney J.; Lederman, Sally A.; Sjödin, Andreas; Jones, Richard; Wang, Shuang; Perera, Frederica P.; Wang, Richard; Rauh, Virginia A.; Herbstman, Julie B.

    2016-01-01

    Introduction Polybrominated diphenyl ethers (PBDEs) comprise a class of halogenated compounds used extensively as flame retardant chemicals in consumer products resulting in nearly ubiquitous human exposure. Mounting evidence suggests that PBDEs are developmental neurotoxicants; however, associations between early life exposure and child behavior have been largely limited to a single developmental time point. Methods The study population consists primarily of white, black and Chinese women who were pregnant on 11 September 2001 and delivered at 1 of 3 downtown New York City hospitals. Maternal–child pairs were followed through age 7 years. Cord blood was collected at delivery and PBDE plasma levels for 210 samples were analyzed by the U.S. Centers for Disease Control and Prevention. The Child Behavior Checklist, a validated maternal-report instrument used for assessing child behavior, was administered annually between the ages of 3 and 7 years. We analyzed the association between natural log-transformed and dichotomized (low vs. high) PBDEs and attention problems using multivariable adjusted negative binomial regression. Results We detected 4 PBDE congeners in more than 50% of samples, with concentrations highest for BDE-47 (median ± IQR: 11.2 ± 19.6 ng/g). In adjusted analyses, we detected associations between BDE-47 (1.21, 95% CI: 1.00, 1.47), and BDE-153 (1.18, 95% CI: 1.00, 1.39) in cord plasma and increased attention problems among children at age 4 (n = 109) but not 6 (n = 107) years. Conclusions Our findings demonstrate a positive trend between prenatal PBDE exposure and early childhood attention problems, and are consistent with previous research reporting associations between prenatal PBDE exposure and disrupted child behaviors. PMID:26344673

  7. Polybrominated diphenyl ethers in relation to autism and developmental delay: a case-control study

    Science.gov (United States)

    2011-01-01

    Background Polybrominated diphenyl ethers (PBDEs) are flame retardants used widely and in increasing amounts in the U.S. over the last few decades. PBDEs and their metabolites cross the placenta and studies in rodents demonstrate neurodevelopmental toxicity from prenatal exposures. PBDE exposures occur both via breastfeeding and hand-to-mouth activities in small children. Methods Participants were 100 children from the CHARGE (CHildhood Autism Risk from Genetics and the Environment) Study, a case-control epidemiologic investigation of children with autism/autism spectrum disorder, with developmental delay and from the general population. Diagnoses of autism were confirmed by the Autism Diagnostic Observation Schedule and Autism Diagnostic Inventory-Revised, and of developmental delay using the Mullen's Scales of Early Learning and the Vineland Adaptive Behavior Scales. Typically developing controls were those with no evidence of delay, autism, or autism spectrum disorder. Eleven PBDE congeners were measured by gas chromatography/mass spectrometry from serum specimens collected after children were assessed. Logistic regression was used to evaluate the association between plasma PBDEs and autism. Results Children with autism/autism spectrum disorder and developmental delay were similar to typically developing controls for all PBDE congeners, but levels were high for all three groups. Conclusions Plasma samples collected post-diagnosis in this study may not represent early life exposures due to changes in diet and introduction of new household products containing PBDEs. Studies with direct measurements of prenatal or infant exposures are needed to assess the possible causal role for these compounds in autism spectrum disorders. PMID:21205326

  8. Polybrominated diphenyl ethers enhance the production of proinflammatory cytokines by the placenta.

    Science.gov (United States)

    Peltier, M R; Klimova, N G; Arita, Y; Gurzenda, E M; Murthy, A; Chawala, K; Lerner, V; Richardson, J; Hanna, N

    2012-09-01

    Polybrominated diphenyl ether(s) (PBDE) are ubiquitous environmental contaminants that bind and cross the placenta but their effects on pregnancy outcome are unclear. It is possible that environmental contaminants increase the risk of inflammation-mediated pregnancy complications such as preterm birth by promoting a proinflammatory environment at the maternal-fetal interface. We hypothesized that PBDE would reduce IL-10 production and enhance the production of proinflammatory cytokines associated with preterm labor/birth by placental explants. Second-trimester placental explants were cultured in either vehicle (control) or 2 μM PBDE mixture of congers 47, 99 and 100 for 72 h. Cultures were then stimulated with 10(6) CFU/ml heat-killed Escherichia coli for a final 24 h incubation and conditioned medium was harvested for quantification of cytokines and PGE(2). COX-2 content and viability of the treated tissues were then quantified by tissue ELISA and MTT reduction activity, respectively. PBDE pre-treatment reduced E. coli-stimulated IL-10 production and significantly increased E. coli-stimulated IL-1β secretion. PBDE exposure also increased basal and bacteria-stimulated COX-2 expression. Basal, but not bacteria-stimulated PGE(2), was also enhanced by PBDE exposure. No effect of PBDE on viability of the explants cultures was detected. In summary, pre-exposure of placental explants to congers 47, 99, and 100 enhanced the placental proinflammatory response to infection. This may increase the risk of infection-mediated preterm birth by lowering the threshold for bacteria to stimulate a proinflammatory response(s). Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Flame retardant exposure: polybrominated diphenyl ethers in blood from Swedish workers.

    Science.gov (United States)

    Sjödin, A; Hagmar, L; Klasson-Wehler, E; Kronholm-Diab, K; Jakobsson, E; Bergman, A

    1999-08-01

    Polybrominated diphenyl ethers (PBDEs) are used as additives in polymers and textiles to prohibit the development of fires. Because of the production and use of PBDEs, their lipophilic characteristics, and persistence, these compounds have become ubiquitous environmental contaminants. The aim of the present study was to determine potential exposures of PBDEs to clerks working full-time at computer screens and personnel at an electronics-dismantling plant, with hospital cleaners as a control group. Five PBDE congeners--2,2',4,4'-tetraBDE; 2,2',4,4',5,5'-hexaBDE; 2,2',4,4',5, 6'-hexaBDE; 2,2',3,4,4',5',6-heptaBDE; and decaBDE--were quantified in blood serum from all three categories of workers. Subjects working at the dismantling plant showed significantly higher levels of all PBDE congeners in their serum as compared to the control group. Decabromodiphenyl ether is present in concentrations of 5 pmol/g lipid weight (lw) in the personnel dismantling electronics; these concentrations are comparable to the concentrations of 2,2',4, 4'-tetraBDE. The latter compound was the dominating PBDE congener in the clerks and cleaners. The major compound in personnel at the dismantling plant was 2,2',3,4,4',5',6-heptaBDE. Concentrations of this PBDE congener are almost twice as high as for 2,2',4, 4'-tetraBDE in these workers and seventy times the level of this heptaBDE in cleaners. The total median PBDE concentrations in the serum from workers at the electronics-dismantling plant, clerks, and cleaners were 37, 7.3, and 5.4 pmol/g lw, respectively. The results show that decabromodiphenyl ether is bioavailable and that occupational exposure to PBDEs occurs at the electronics-dismantling plant.

  10. Polybrominated diphenyl ethers and their hydroxylated and methoxylated derivatives in seafood obtained from Puget Sound, WA

    Energy Technology Data Exchange (ETDEWEB)

    Cade, Sara E.; Kuo, Li-Jung; Schultz, Irvin R.

    2018-03-07

    Synthetic polybrominated diphenyl ethers (PBDEs) are ubiquitous environmental contaminants and known to occur in most food items. Consumer fish products have been identified as having some of the highest PBDE levels found in USA food sources. Natural formation of hydroxylated (OH-) and methoxylated (MeO-) PBDEs are also known to occur in simple marine organisms, which may be bioaccumulated by seafood. In this study, we report findings of an initial survey of PBDE, OH-PBDE and MeO-PBDE content in common seafood items available to residents living in the Puget Sound region of Washington State. Seafood samples were either purchased from local grocery stores or caught off the coast of SE Alaska and in Puget Sound. The edible portions of the seafood were analyzed, which for finfish was white muscle (skinless fillets) and for shellfish, either the entire soft tissue (bivalves) or processed meat (calamari, shrimp and scallops). Results indicated that finfish typically had higher levels of PBDEs compared to shellfish with BDE-47 and BDE-99 as the most common congeners detected. Among shellfish, bivalves (clams and mussels) were notable for having much higher levels of OH- and MeO-PBDEs compared to other types of seafood with 6'-OH-BDE-47 and 2'-MeO-BDE-68 being the more common OH- and MeO- congeners, respectively. Based on our results and recent updates to daily fish consumption rates, estimated intake rates for Washington State residents will be between 34 and 644 ng PBDEs/day, depending on species consumed. For the OH- and MeO- forms, daily exposure is much more variable but typically would range between 15 and 90 ng/day for most seafood types. If shellfish are primarily consumed, OH-PBDE intake could be as high as 350 ng/day. These daily intake rates for PBDEs are higher than most dietary intake rates calculated for populations in other world regions.

  11. Review on the occurrence and profiles of polybrominated diphenyl ethers in the Philippines.

    Science.gov (United States)

    Mackintosh, Susan A; Wallace, Joshua S; Gross, Michael S; Navarro, Denise D; Pérez-Fuentetaja, Alicia; Alaee, Mehran; Montecastro, Doris; Aga, Diana S

    2015-12-01

    The environmental occurrence of polybrominated diphenyl ethers (PBDEs) has been a subject of concern for the past decade because they are persistent, bioaccumulative, and toxic. These compounds have been listed as persistent organic pollutants (POPs) by the Stockholm Convention and are expected to disperse in the global environment even after their use and production. While the occurrence of PBDEs has been well characterized in environmental and biological samples from North America, Europe, and some Asian countries (i.e. China, Japan, and Korea), there is a scarcity of available data in developing Asian countries, such as the Philippines. Examination of PBDE contamination in the Philippine environment is particularly important because regulations have only recently been implemented on the production and use of PBDEs in this country. Additionally, the Philippines receives e-waste from Western countries, which is becoming a major source of organic contaminants in the tropical Asian regions. Ultimately, the Philippines may be a hot spot for contributing to on-going global PBDE pollution due to long-range atmospheric transport. This paper presents a review of the available literature on PBDEs in both environmental and biological samples collected from the Philippines. It is also intended to provide an overview on the levels and congener profiles of PBDEs in samples from the Philippines and to compare these data with other Asian countries. New data are presented on PBDE occurrence and congener profiles in fish commonly consumed by Filipinos and in particulate matter samples collected in Metro Manila, the capital of the Philippines. Both studies contribute to the available knowledge of PBDEs in the Philippines. We aim to stress the importance of future studies in countries receiving e-wastes, such as the Philippines, and suggest what future directions might be taken to enhance the available data on the presence of PBDEs in the Philippine environment. Copyright © 2015

  12. Biomagnification and debromination of polybrominated diphenyl ethers in a coastal ecosystem in Tokyo Bay

    Energy Technology Data Exchange (ETDEWEB)

    Mizukawa, Kaoruko; Yamada, Toshiko [Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Matsuo, Hiroaki; Takeuchi, Ichiro [Department of Life Environment Conservation, Faculty of Agriculture, Ehime University, Tarumi 3-5-7, Matsuyama, Ehime 790-8566 (Japan); Tsuchiya, Kotaro [Faculty of Marine Science, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477 (Japan); Takada, Hideshige, E-mail: shige@cc.tuat.ac.jp [Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan)

    2013-04-01

    By field sampling and laboratory experiments we compared the mechanisms by which polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are biomagnified. We measured PBDEs and PCBs, together with stable carbon and nitrogen isotopes as an index of trophic level, in low-trophic-level organisms collected from a coastal area in Tokyo Bay. PBDEs were biomagnified to a lesser degree than PCBs. The more hydrophobic congeners of each were biomagnified more. However, the depletion of BDE congeners BDE99 and BDE153 from fish was suggested. To study congener-specific biotransformation of halogenated compounds, we conducted an in vitro experiment using hepatic microsomes of two species of fish and five BDE congeners (BDE47, 99, 100, 153, and 154) and five CB congeners with the same substitution positions as the PBDEs. BDE99 and 153 were partially debrominated, but BDE47 and 154 were not debrominated. This congener-specific debromination is consistent with the field results. Both in vitro and field results suggested selective debromination at the meta position. The CB congeners were not transformed in vitro. This result is also consistent with the field results, that PCBs were more biomagnified than PBDEs. We conclude that metabolizability is an important factor in the biomagnification of chemicals, but other factors must be responsible for the lower biomagnification of PBDEs in natural ecosystems. Highlights: ► PBDEs were less biomagnified than PCBs in low-trophic-level organisms in Tokyo Bay. ► Depletion of PBDE congeners BDE99 and BDE153 from fish was suggested. ► BDE99 and 153 were debrominated in in vitro experiment using hepatic microsomes of fish. ► BDE47, 100, and 154 as well as PCB congeners were not transformed in vitro. ► Both in vitro and field results suggested selective meta-protonation of PBDEs.

  13. Separation of polybrominated diphenyl ethers in fish for compound-specific stable carbon isotope analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Yan-Hong [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Graduate University of Chinese Academy of Sciences, Beijing, 100049 (China); Luo, Xiao-Jun, E-mail: luoxiaoj@gig.ac.cn [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen, Hua-Shan; Wu, Jiang-Ping; Chen, She-Jun; Mai, Bi-Xian [State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China)

    2012-05-15

    A separation and isotopic analysis method was developed to accurately measure the stable carbon isotope ratios of polybrominated diphenyl ethers (PBDEs) with three to six substituted bromine atoms in fish samples. Sample extracts were treated with concentrated sulfuric acid to remove lipids, purified using complex silica gel column chromatography, and finally processed using alumina/silica (Al/Si) gel column chromatography. The purities of extracts were verified by gas chromatography and mass spectrometry (GC-MS) in the full-scan mode. The average recoveries of all compounds across the purification method were between 60% and 110%, with the exception of BDE-154. The stable carbon isotopic compositions of PBDEs can be measured with a standard deviation of less than 0.5 Per-Mille-Sign . No significant isotopic fraction was found during the purification of the main PBDE congeners. A significant change in the stable carbon isotope ratio of BDE-47 was observed in fish carcasses compared to the original isotopic signatures, implying that PBDE stable carbon isotopic compositions can be used to trace the biotransformation of PBDEs in biota. - Highlights: Black-Right-Pointing-Pointer A method for the purification of PBDEs for CSIA was developed. Black-Right-Pointing-Pointer The {delta}{sup 13}C of PBDE congeners can be measured with a standard deviation of less than 0.5 Per-Mille-Sign . Black-Right-Pointing-Pointer Common carp were exposed to a PBDE mixture to investigate debromination. Black-Right-Pointing-Pointer Ratios of the {delta}{sup 13}C values can be used to trace the debromination of PBDE in fish.

  14. Distribution of polybrominated diphenyl ethers in Japanese autopsy tissue and body fluid samples.

    Science.gov (United States)

    Hirai, Tetsuya; Fujimine, Yoshinori; Watanabe, Shaw; Nakano, Takeshi

    2012-09-01

    Brominated flame retardants are components of many plastics and are used in products such as cars, textiles, televisions, and personal computers. Human exposure to polybrominated diphenyl ether (PBDE) flame retardants has increased exponentially during the last three decades. Our objective was to measure the body burden and distribution of PBDEs and to determine the concentrations of the predominant PBDE congeners in samples of liver, bile, adipose tissue, and blood obtained from Japanese autopsy cases. Tissues and body fluids obtained from 20 autopsy cases were analyzed. The levels of 25 PBDE congeners, ranging from tri- to hexa-BDEs, were assessed. The geometric means of the sum of the concentrations of PBDE congeners having detection frequencies >50 % (ΣPBDE) in the blood, liver, bile, and adipose tissue were 2.4, 2.6, 1.4, and 4.3 ng/g lipid, respectively. The most abundant congeners were BDE-47 and BDE-153, followed by BDE-100, BDE-99, and BDE-28+33. These concentrations of PBDE congeners were similar to other reports of human exposure in Japan but were notably lower than concentrations than those reported in the USA. Significant positive correlations were observed between the concentrations of predominant congeners and ΣPBDE among the samples analyzed. The ΣPBDE concentration was highest in the adipose tissue, but PBDEs were distributed widely among the tissues and body fluids analyzed. The PBDE levels observed in the present study are similar to those reported in previous studies in Japan and significantly lower than those reported in the USA.

  15. Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

    Energy Technology Data Exchange (ETDEWEB)

    Ni Honggang; Cao Shanping; Chang Wenjing [Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China); Zeng Hui, E-mail: huizeng0608@gmail.com [Shenzhen Key Laboratory of Circular Economy, Shenzhen Graduate School, Peking University, Shenzhen 518055 (China); Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871 (China)

    2011-07-15

    This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM{sub 2.5} (Particulate Matter up to 2.5 {mu}m in size) bounded {Sigma}{sub 15}PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM{sub 10} (Particulate Matter up to 10 {mu}m in size) bounded {Sigma}{sub 15}PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of {Sigma}{sub 15}PBDEs via dust inhalation and ingestion for adults reached {approx}141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. - Highlights: > Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than that in the old ones. > PBDE emissions from indoor sources can be expected to continue for a long time as the PBDE-containing products in offices were to be kept many years. > The household consumer products, especially computers, are the main sources of PBDEs in central air conditioner filter dust. > Further studies are needed to fully understand the emission mechanism of PBDE from indoor consumer products. - PBDEs in central air conditioner filter dust from a new building were investigated

  16. Polybrominated diphenyl ethers in indoor air during waste TV recycling process

    International Nuclear Information System (INIS)

    Guo, Jie; Lin, Kuangfei; Deng, Jingjing; Fu, Xiaoxu; Xu, Zhenming

    2015-01-01

    Graphical abstract: - Highlights: • Air in the workshops was seriously contaminated by TV recycling activities. • PBDEs profiles and levels varied with particulate matters and different workshops. • Equilibrium between gas-particle partitioning was disrupted by recycling process. • The highest occupational exposure concentrations occurred during heating process. - Abstract: Recycling process for waste TV sets mainly consists of dismantling, printed wiring board (PWB) heating, PWB recycling, and plastic crushing in formal recycling plant. Polybrominated diphenyl ethers (PBDEs) contained in waste TV sets are released to indoor air. Air samples at 4 different workshops were collected to measure the PBDEs concentrations in both gaseous and particulate phases. The mean concentrations of ∑PBDEs in indoor air were in the range of 6780–2,280,000 pg/m 3 . The highest concentration in gaseous phase (291,000 pg/m 3 ) was detected in the PWB heating workshop. The ∑ 12 PBDEs concentrations in PM 2.5 and PM 10 at the 4 workshops ranged in 6.8–6670 μg/g and 32.6–6790 μg/g, respectively. The gas-particle partitioning of PBDEs was disrupted as PBDEs were continuously released during the recycling processes. Occupational exposure assessment showed that only the exposure concentration of BDE-47 (0.118 μg/kg/day) through inhalation in the PWB heating workshop for workers without facemask exceeded the reference dose (0.1 μg/kg/day), posing a health hazard to workers. All the results demonstrated that recycling of TV sets was an important source of PBDEs emission, and PBDEs emission pollution was related to the composition of TV sets, interior dust, and recycling process

  17. Incidence of polybrominated diphenyl ethers in central air conditioner filter dust from a new office building

    International Nuclear Information System (INIS)

    Ni Honggang; Cao Shanping; Chang Wenjing; Zeng Hui

    2011-01-01

    This study examined polybrominated diphenyl ethers (PBDEs) in central air conditioner filter (CACF) dust from a new office building in Shenzhen, China. Human exposure to PBDE via dust inhalation and ingestion were also estimated. PBDEs level in CACF dust was lower than those in the other countries and regions. Approximately 0.671 pg/kg bw/day PM 2.5 (Particulate Matter up to 2.5 μm in size) bounded Σ 15 PBDEs can be inhaled deep into the lungs and 4.123 pg/kg bw/day PM 10 (Particulate Matter up to 10 μm in size) bounded Σ 15 PBDEs tend to be deposited in the upper parts of the respiratory system. The average total intake of Σ 15 PBDEs via dust inhalation and ingestion for adults reached ∼141 pg/kg bw/day in this building. This value was far below the reference dose (RfD) recommended by United States Environmental Protection Agency. Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than the old ones. - Highlights: → Human exposure to PBDEs via dust inhalation and ingestion in the new building is less than that in the old ones. → PBDE emissions from indoor sources can be expected to continue for a long time as the PBDE-containing products in offices were to be kept many years. → The household consumer products, especially computers, are the main sources of PBDEs in central air conditioner filter dust. → Further studies are needed to fully understand the emission mechanism of PBDE from indoor consumer products. - PBDEs in central air conditioner filter dust from a new building were investigated

  18. Measurement of the flame retardants polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCDD) in house dust

    Energy Technology Data Exchange (ETDEWEB)

    Stapleton, H.; Dodder, N.; Schantz, M.; Wise, S. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    2004-09-15

    Current monitoring of polybrominated diphenyl ethers (PBDEs) has shown that concentrations are increasing in the environment very rapidly with doubling times as short as three to five years. North America consumes a large percentage of the global market demand for PBDEs, and as a result, concentrations of PBDEs in human milk and serum are an order of magnitude higher in women from North America relative to Europe. Within sampled populations, PBDE levels in human serum have been shown to range over an order of magnitude, and high levels cannot always be attributed to occupational exposure, age or diet. One source that may be responsible for these observations is exposure in the home. These compounds are liberally applied to many common household items such as furniture, mattresses, computers and TVs to retard or hinder the outbreak of fire. Over time, these flame retardants may leach out into the home environment, where they may be inhaled or ingested, resulting in elevated levels in human serum. Very few studies have examined PBDE levels within the home and only one study has measured the concentrations of two PBDE congeners in house dust. The present study was undertaken to measure a suite PBDE congeners in house dust from a variety of homes and to assess the contribution of the three commercial PBDE mixtures (penta-, octa- and decaBDE) to the house dust composition. In addition, we also measured the concentrations of hexabromocyclododecane (HBCDD), another flame retardant. Correlations with properties of the houses such as year of construction, square footage, carpeting coverage and number of computers in the house were also examined for any positive influences.

  19. Comparing black carbon types in sequestering polybrominated diphenyl ethers (PBDEs) in sediments

    International Nuclear Information System (INIS)

    Jia, Fang; Gan, Jay

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are widely found in sediments, especially congeners from the penta-BDE formula. Due to their strong affinity for black carbon (BC), bioavailability of PBDEs may be decreased in BC-amended sediments. In this study, we used a matrix-SPME method to measure the freely dissolved concentration (C free ) of PBDEs as a parameter of their potential bioavailability and evaluated the differences among biochar, charcoal, and activated carbon. Activated carbon displayed a substantially greater sequestration capacity than biochar or charcoal. At 1% amendment rate in sediment with low organic carbon (OC) content (0.12%), C free of six PBDEs was reduced by 47.5–78.0%, 47.3–77.5%, and 94.1–98.3% with biochar, charcoal, and activated carbon, respectively, while the sequestration was more limited in sediment with high OC content (0.87%). Therefore, it is important to consider the type and properties of the BC and the sediment in BC-based remediation or mitigation. -- Highlights: • A matrix-SPME method was developed for measuring C free of PBDEs in sediment porewater. • Different black carbon types differed greatly in their ability to decrease C free of PBDEs in sediments. • Activated carbon was much more efficient in sequestering PBDEs than biochar or charcoal. • The effect of black carbon was more pronounced in sediment with lower indigenous OC content. -- Biochar, charcoal, and activated carbon have been compared for their efficacy in sequestering PBDEs in sediments by using a matrix-SPME method

  20. Fast Removal of Polybrominated Diphenyl Ethers from Aqueous Solutions by Using Low-Cost Adsorbents

    Directory of Open Access Journals (Sweden)

    Renin Chang

    2017-01-01

    Full Text Available 4-Dibromodiphenyl ether (BDE-3 and 4,4′-dibromodiphenyl ether (BDE-15 are two of the major polybrominated diphenyl ethers used as flame-retardant additives in computer main boards and in fireproof building materials. In this study, we evaluated the potential of three low-cost adsorbents, black tea, green tea, and coconut palm leaf powders, to adsorb BDE-3 and BDE-15 from aqueous solutions. The results showed that pressure steam washing of the adsorbents increased their capacities to adsorb BDE-3 and BDE-15. The maximum adsorption capacities of pressure steam–washed black tea, green tea, and coconut palm leaf powders were 21.85 mg·L−1, 14.56 mg·L−1 and 22.47 mg·L−1, respectively. The results also showed that the adsorption equilibrium (qe was achieved at 4 min. Moreover, 97.8% of BDE-3 and 98.5% of BDE-15 could be removed by adsorbents pretreated with pressure steam washing. The kinetic data fitted well with a pseudo-second-order equation. The adsorption rate constants (k2 of all pressure steam–washed adsorbents ranged from 8.16 × 10−3 to 6.61 × 10−2 g·(mg·L−1−1·s−1, and the amount adsorbed at qe by all pressure steam–washed adsorbents ranged from 4.21 to 4.78 mg·L−1. Green alga Chlorella vulgaris was used as the test organism and the median effective concentration values of BDE-3 and BDE-15 were 7.24 and 3.88 mg·L−1, respectively. After BDE-3 and BDE-15 were removed from the solution, their biotoxicities markedly decreased. These findings indicate that these low-cost adsorbents can be used to remove BDE-3 and BDE-15 from aqueous solutions and wastewater.

  1. Analytical determination of specific 4,4'-methylene diphenyl diisocyanate hemoglobin adducts in human blood.

    Science.gov (United States)

    Gries, Wolfgang; Leng, Gabriele

    2013-09-01

    4,4'-Methylene diphenyl diisocyanate (MDI) is one of the most important isocyanates in the industrial production of polyurethane and other MDI-based synthetics. Because of its high reactivity, it is known as a sensitizing agent, caused by protein adducts. Analysis of MDI is routinely done by determination of the nonspecific 4,4'-methylenedianiline as a marker for MDI exposure in urine and blood. Since several publications have reported specific adducts of MDI and albumin or hemoglobin, more information about their existence in humans is necessary. Specific adducts of MDI and hemoglobin were only reported in rats after high-dose MDI inhalation. The aim of this investigation was to detect the hemoglobin adduct 5-isopropyl-3-[4-(4-aminobenzyl)phenyl]hydantoin (ABP-Val-Hyd) in human blood for the first time. We found values up to 5.2 ng ABP-Val-Hyd/g globin (16 pmol/g) in blood samples of workers exposed to MDI. Because there was no information available about possible amounts of this specific MDI marker, the analytical method focused on optimal sensitivity and selectivity. Using gas chromatography-high-resolution mass spectrometry with negative chemical ionization, we achieved a detection limit of 0.02 ng ABP-Val-Hyd/g globin (0.062 pmol/g). The robustness of the method was confirmed by relative standard deviations between 3.0 and 9.8 %. Combined with a linear detection range up to 10 ng ABP-Val-Hyd/g globin (31 pmol/g), the enhanced precision parameter demonstrates that the method described is optimized for screening studies of the human population.

  2. Temporal variations of perfluoroalkyl substances and polybrominated diphenyl ethers in alpine snow

    International Nuclear Information System (INIS)

    Kirchgeorg, Torben; Dreyer, Annekatrin; Gabrieli, Jacopo; Kehrwald, Natalie; Sigl, Michael; Schwikowski, Margit

    2013-01-01

    The occurrence and temporal variation of 18 perfluoroalkyl substances (PFASs) and 8 polybrominated diphenyl ethers (PBDEs) in the European Alps was investigated in a 10 m shallow firn core from Colle Gnifetti in the Monte Rosa Massif (4455 m above sea level). The firn core encompasses the years 1997–2007. Firn core sections were analyzed by liquid chromatography–tandem mass spectrometry (PFASs) and gas chromatography–mass spectrometry (PBDEs). We detected 12 PFASs and 8 PBDEs in the firn samples. Perfluorobutanoic acid (PFBA; 0.3–1.8 ng L −1 ) and perfluorooctanoic acid (PFOA; 0.2–0.6 ng L −1 ) were the major PFASs while BDE 99 ( −1 ) and BDE 47 (n.d.–2.6 ng L −1 ) were the major PBDEs. This study demonstrates the occurrence of PFASs and PBDEs in the European Alps and provides the first evidence that PFASs compositions may be changing to PFBA-dominated compositions. -- Highlights: •PFASs and PBDEs were detected in low ng L −1 concentrations in an Alpine firn core. •BDE 47, BDE 99 and BDE 209 are the dominating PBDEs. •PFOA, PFNA and PFBA are the major PFASs. •We demonstrate a change in the PFASs composition. •Atmospheric degradation of volatile precursor might be the main source for >C8 PFCAs. -- PFAS and PBDE concentrations in European Alpine snow provide information about the occurrence, accumulation and recent changes of these persistent organic pollutants in Alpine regions

  3. Occurrence of polybrominated diphenyl ethers in floor and elevated surface house dust from Shanghai, China.

    Science.gov (United States)

    Niu, Dong; Qiu, Yanling; Li, Li; Zhou, Yihui; Du, Xinyu; Zhu, Zhiliang; Chen, Ling; Lin, Zhifen

    2018-04-24

    House dust is the main source of human exposure to flame retardants by ingestion. This study investigated the occurrence of polybrominated diphenyl ethers (PBDEs) in indoor dust from 22 houses in Shanghai, China. House dust was separately collected from the floor and elevated furnishings surface (mostly between 0.5 and 2 m height) for comparison. The concentrations of ∑ 22 PBDEs ranged from 19.4 to 3280 ng/g (with a geometric mean of 203 ng/g) and from 55.1 to 792 ng/g (with a geometric mean of 166 ng/g) in floor dust (FD) and elevated surface dust (ESD), respectively. BDE-209 was the predominant congener, accounting for about 73.1% of total PBDE burdens. In terms of congener profiles, the comparison of FD and ESD revealed no significant differences except for the ratio of BDE-47/BDE-99. ESD samples displayed a ratio of BDE-47/BDE-99 very similar to commercial penta-BDE products DE-71 while the ratio in FD was exceptionally higher. Significant correlation was found between concentrations of commercial penta-BDE compositions in FD and ESD (p house dust exhibited temporal stability. Human exposure to PBDEs via dust ingestion was estimated. The highest daily intake of PBDEs was for toddlers by using 95th percentile concentrations of PBDEs via high dust ingestion in FD (23.07 ng/kg bw/day). About 20-fold difference in exposure estimates between toddlers and adults supports that toddlers are facing greater risk from indoor floor dust. Expectedly, this study highlighted the point that residents in Shanghai were exposed to low doses of PBDEs in house dust.

  4. Measurement and modeling of diel variability of polybrominated diphenyl ethers and chlordanes in air.

    Science.gov (United States)

    Moeckel, Claudia; Macleod, Matthew; Hungerbühler, Konrad; Jones, Kevin C

    2008-05-01

    Short-term variability of concentrations of polybrominated diphenyl ethers (PBDEs) and chlordanes in air at a semirural site in England over a 5 day period is reported. Four-hour air samples were collected during a period dominated by a high pressure system that produced stable diel (24-h) patterns of meteorological conditions such as temperature and atmospheric boundary layer height. PBDE and chlordane concentrations showed clear diel variability with concentrations in the afternoon and evening being 1.9 - 2.7 times higher than in the early morning. The measurements are interpreted using a multimedia mass balance model parametrized with forcing functions representing local temperature, atmospheric boundary layer height, wind speed and hydroxyl radical concentrations. Model results indicate that reversible, temperature-controlled air-surface exchange is the primary driver of the diel concentration pattern observed for chlordanes and PBDE 28. For higher brominated PBDE congeners (47, 99 and 100), the effect of variable atmospheric mixing height in combination with irreversible deposition on aerosol particles is dominant and explains the diel patterns almost entirely. Higher concentrations of chlordanes and PBDEs in air observed at the end of the study period could be related to likely source areas using back trajectory analysis. This is the first study to clearly document diel variability in concentrations of PBDEs in air over a period of several days. Our model analysis indicates that high daytime and low nighttime concentrations of semivolatile organic chemicals can arise from different underlying driving processes, and are not necessarily evidence of reversible air-surface exchange on a 24-h time scale.

  5. Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China.

    Science.gov (United States)

    Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

    2016-05-01

    A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC-MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEslow, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16-5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Polybrominated diphenyl ethers in indoor air during waste TV recycling process

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Jie [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China); Lin, Kuangfei; Deng, Jingjing; Fu, Xiaoxu [State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai 200237 (China); Xu, Zhenming, E-mail: zmxu@sjtu.edu.cn [School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240 (China)

    2015-02-11

    Graphical abstract: - Highlights: • Air in the workshops was seriously contaminated by TV recycling activities. • PBDEs profiles and levels varied with particulate matters and different workshops. • Equilibrium between gas-particle partitioning was disrupted by recycling process. • The highest occupational exposure concentrations occurred during heating process. - Abstract: Recycling process for waste TV sets mainly consists of dismantling, printed wiring board (PWB) heating, PWB recycling, and plastic crushing in formal recycling plant. Polybrominated diphenyl ethers (PBDEs) contained in waste TV sets are released to indoor air. Air samples at 4 different workshops were collected to measure the PBDEs concentrations in both gaseous and particulate phases. The mean concentrations of ∑PBDEs in indoor air were in the range of 6780–2,280,000 pg/m{sup 3}. The highest concentration in gaseous phase (291,000 pg/m{sup 3}) was detected in the PWB heating workshop. The ∑{sub 12}PBDEs concentrations in PM{sub 2.5} and PM{sub 10} at the 4 workshops ranged in 6.8–6670 μg/g and 32.6–6790 μg/g, respectively. The gas-particle partitioning of PBDEs was disrupted as PBDEs were continuously released during the recycling processes. Occupational exposure assessment showed that only the exposure concentration of BDE-47 (0.118 μg/kg/day) through inhalation in the PWB heating workshop for workers without facemask exceeded the reference dose (0.1 μg/kg/day), posing a health hazard to workers. All the results demonstrated that recycling of TV sets was an important source of PBDEs emission, and PBDEs emission pollution was related to the composition of TV sets, interior dust, and recycling process.

  7. Characterizing the sorption of polybrominated diphenyl ethers (PBDEs) to cotton and polyester fabrics under controlled conditions

    Energy Technology Data Exchange (ETDEWEB)

    Saini, Amandeep [Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada); Rauert, Cassandra [School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Simpson, Myrna J. [Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada); Harrad, Stuart [School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham B15 2TT (United Kingdom); Diamond, Miriam L., E-mail: miriam.diamond@utoronto.ca [Department of Earth Sciences, 22 Russell Street, University of Toronto, Toronto, ON M5S 3B1 (Canada); Department of Physical and Environmental Sciences, University of Toronto Scarborough, 1265 Military trail, Toronto, ON M1C 1A4 (Canada)

    2016-09-01

    Cotton and polyester, physically and chemically different fabrics, were characterized for sorption of gas-phase polybrominated diphenyl ethers (PBDEs). Scanning electron microscopic (SEM) images and BET specific surface area (BET-SSA) analysis showed cotton's high microsurface area; NMR analysis showed richness of hexose- and aromatic-carbon in cotton and polyester, respectively. Cotton and polyester sorbed similar concentrations of gas-phase PBDEs in chamber studies, when normalized to planar surface area. However, polyester concentrations were 20–50 times greater than cotton when normalized to BET-SSA, greater than the 10 times difference in BET-SSA. The difference in sorption between cotton and polyester is hypothesized to be due to ‘dilution’ due to cotton's large BET-SSA and/or greater affinity of PBDEs for aromatic-rich polyester. Similar fabric-air area normalized distribution coefficients (K'{sub D}, 10{sup 3} to 10{sup 4} m) for cotton and polyester support air-side controlled uptake under non-equilibrium conditions. K'{sub D} values imply that 1 m{sup 2} of cotton or polyester fabrics would sorb gas-phase PBDEs present in 10{sup 3} to 10{sup 4} m{sup 3} of equivalent air volume at room temperature over one week, assuming similar air flow conditions. Sorption of PBDEs to fabrics has implications for their fate indoors and human exposure. - Highlights: • Sorption of gas-phase PBDEs by cotton and polyester fabrics • Similar sorption to cotton and polyester per unit planar surface area • Greater sorption by polyester/BET-SSA; cotton's dilution or polyester’s affinity • 1 m{sup 2} fabric sorbs PBDEs in 10{sup 3} to 10{sup 4} m{sup 3} of equivalent air volume • Clothing likely a large indoor sink of PBDEs and influence human exposure.

  8. Astrocyte-neuron interaction in diphenyl ditelluride toxicity directed to the cytoskeleton

    International Nuclear Information System (INIS)

    Heimfarth, Luana; Silva Ferreira, Fernanda da; Pierozan, Paula; Mingori, Moara Rodrigues; Moreira, José Cláudio Fonseca; Batista Teixeira da Rocha, João; Pessoa-Pureur, Regina

    2017-01-01

    Highlights: • Diphenyl ditelluride is toxic to the cytoskeleton of neural cells in vitro. • Hypophosphorylation disrupts cytoskeletal homeostasis and causes cell dysfunction. • Calcium signaling underlies hypophosphorylation of intermediate filaments. • Actin disorganization causes altered astrocyte morphology. • Astrocyte cytoskeleton is more susceptible than neuronal cytoskeleton. - Abstract: Diphenylditelluride (PhTe) 2 is a neurotoxin that disrupts cytoskeletal homeostasis. We are showing that different concentrations of (PhTe) 2 caused hypophosphorylation of glial fibrillary acidic protein (GFAP), vimentin and neurofilament subunits (NFL, NFM and NFH) and altered actin organization in co-cultured astrocytes and neurons from cerebral cortex of rats. These mechanisms were mediated by N-methyl-D-aspartate (NMDA) receptors without participation of either L-type voltage-dependent calcium channels (L-VDCC) or metabotropic glutamate receptors. Upregulated Ca 2+ influx downstream of NMDA receptors activated Ca 2+ -dependent protein phosphatase 2B (PP2B) causing hypophosphorylation of astrocyte and neuron IFs. Immunocytochemistry showed that hypophosphorylated intermediate filaments (IF) failed to disrupt their organization into the cytoskeleton. However, phalloidin-actin-FITC stained cytoskeleton evidenced misregulation of actin distribution, cell spreading and increased stress fibers in astrocytes. βIII tubulin staining showed that neurite meshworks are not altered by (PhTe) 2 , suggesting greater susceptibility of astrocytes than neurons to (PheTe) 2 toxicity. These findings indicate that signals leading to IF hypophosphorylation fail to disrupt the cytoskeletal IF meshwork of interacting astrocytes and neurons in vitro however astrocyte actin network seems more susceptible. Our findings support that intracellular Ca 2+ is one of the crucial signals that modulate the action of (PhTe) 2 in co-cultured astrocytes and neurons and highlights the cytoskeleton

  9. Polybrominated diphenyl ethers in fish and sediment from river polluted by electronic waste

    Energy Technology Data Exchange (ETDEWEB)

    Luo Qian [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China); Cai Zongwei [Department of Chemistry, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China)]. E-mail: zwcai@hkbu.edu.hk; Wong Minghung [Croucher Institute for Environmental Sciences and Department of Biology, Hong Kong Baptist University, Kowloon Tong, Hong Kong (China)]. E-mail: mhwong@hkbu.edu.hk

    2007-09-20

    The present study investigated contamination of polybrominated diphenyl ethers (PBDEs) in sediment and fish samples collected from rivers in Guiyu, China where electronic waste (e-waste) is recycled and disposed. PBDE congeners with mono-to hepta-brominated and deca-brominated substitutions were detected using {sup 13}C{sub 12} isotope dilution GC/MS/MS and GC/MS methods, respectively. The total PBDE concentrations ranged from 4434 to 16088 ng/g (dry weight) in Nanyang River bank sediment, from 55 to 445 ng/g in Nanyang River bottom sediment and 51.3 to 365 ng/g in Lianjiang River bottom sediment in Guiyu compared with those from 16.1 to 21.4 ng/g in wastewater discharged from a vehicle repairing workshop in Lo Uk Tsuen in Hong Kong. No PBDE congeners were detected in bottom sediment and fish from Mai Po Marshes in Hong Kong. The mean concentrations of total PBDEs in mixed muscles of tilapia (Oreochromis spp) from Lianjiang River were 115 ng/g wet weight (ww) and from wastewater in Hong Kong were 4.1 ng/g ww. Highest mean PBDE concentration was obtained in liver (2687 ng/g ww), followed by abdomen muscle (1088 ng/g ww) of bighead carp (Aristichthys nobilis) collected from Nanyang River. A significant correlation of concentration of each PBDE congener between sediment and muscle from Guiyu was observed. The present results of total PBDEs in sediment and fish were 10 and 1000 times higher than other studies. Open burning and dumping of e-waste are the major causes of PBDE contamination.

  10. Sources, emissions, and fate of polybrominated diphenyl ethers and polychlorinated biphenyls indoors in Toronto, Canada.

    Science.gov (United States)

    Zhang, Xianming; Diamond, Miriam L; Robson, Matthew; Harrad, Stuart

    2011-04-15

    Indoor air concentrations of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) measured in 20 locations in Toronto ranged 0.008-16 ng·m(-3) (median 0.071 ng·m(-3)) and 0.8-130.5 ng·m(-3) (median 8.5 ng·m(-3)), respectively. PBDE and PCB air concentrations in homes tended to be lower than that in offices. Principal component analysis of congener profiles suggested that electrical equipment was the main source of PBDEs in locations with higher concentrations, whereas PUF furniture and carpets were likely sources to locations with lower concentrations. PCB profiles in indoor air were similar to Aroclors 1248, 1232, and 1242 and some exterior building sealant profiles. Individual PBDE and PCB congener concentrations in air were positively correlated with colocated dust concentrations, but total PBDE and total PCB concentrations in these two media were not correlated. Equilibrium partitioning between air and dust was further examined using log-transformed dust/air concentration ratios for which lower brominated PBDEs and all PCBs were correlated with K(OA). This was not the case for higher brominated BDEs for which the measured ratios fell below those based on K(OA) suggesting the air-dust partitioning process could be kinetically limited. Total emissions of PBDEs and PCBs to one intensively studied office were estimated at 87-550 ng·h(-1) and 280-5870 ng·h(-1), respectively, using the Multimedia Indoor Model of Zhang et al. Depending on the air exchange rate, up to 90% of total losses from the office could be to outdoors by means of ventilation. These results support the hypotheses that dominant sources of PBDEs differ according to location and that indoor concentrations and hence emissions contribute to outdoor concentrations due to higher indoor than outdoor concentrations along with estimates of losses via ventilation.

  11. Caffeine and diphenyl diselenide improve long-term memory impaired in middle-aged rats.

    Science.gov (United States)

    Leite, Marlon R; Marcondes Sari, Marcel Henrique; de Freitas, Mayara L; Oliveira, Lia P; Dalmolin, Laíza; Brandão, Ricardo; Zeni, Gilson

    2014-05-01

    The aim of the present study was to evaluate the effects of diphenyl diselenide (PhSe)2 supplemented diet (10ppm) associated to the administration of caffeine (15mg/kg; i.g.) for 30days on the novel object recognition memory in middle-aged rats. The present findings showed that (PhSe)2-supplemented diet enhanced short-term memory, but not long-term memory, of middle-aged rats in the novel object recognition task. The (PhSe)2 supplemented diet associated with caffeine administration improved long-term memory, but did not alter short-term memory, impaired in middle-aged rats. Daily caffeine administration to middle-aged rats had no effect on the memory tasks. Diet supplemented with (PhSe)2 plus caffeine administration increased the number of crossings and rearings reduced in middle-aged rats. Caffeine administration plus (PhSe)2 diets were effective in increasing the number of rearings and crossings, respectively, in middle-aged rats, [(3)H] glutamate uptake was reduced in hippocampal slices of rats from (PhSe)2 and caffeine plus (PhSe)2 groups. In addition, animals supplemented with (PhSe)2 showed an increase in the pCREB/CREB ratio whereas pAkt/Akt ratio was not modified. These results suggest that the effects of (PhSe)2 on the short-term memory may be related to its ability to decrease the uptake of glutamate, influencing the increase of CREB phosphorylation. (PhSe)2-supplemented diet associated to the administration of caffeine improved long-term memory impaired in middle-aged rats, an effect independent of CREB and Akt phosphorylation. Copyright © 2014 Elsevier Inc. All rights reserved.

  12. Summer atmospheric polybrominated diphenyl ethers in urban and rural areas of northern China

    International Nuclear Information System (INIS)

    Wang Chen; Li Wei; Chen Jiwei; Wang Hongqijie; Li Tongchao; Shen Guofeng; Shen Huizhong; Huang Ye; Wang Rong; Wang Bin; Zhang Yanyan; Tang Jianhui; Liu Wenxin; Wang Xilong; Tao Shu

    2012-01-01

    High levels of polybrominated diphenyl ethers (PBDEs) have been extensively reported in urban areas and at e-waste recycling sites in coastal China. However, data are scarce in northern China and are not available in rural areas at all. In addition, it is often believed that air concentrations in rural areas are lower than those in urban areas without distinguishing rural residential areas and open fields. In this study, air samples were collected at 17 sites covering urban and rural (residential and open field) areas in northern China using active samplers. With BDE-209 dominated in all congeners, the average concentrations of BDE-209 (41 ± 72 pg/m 3 ) and other 13 PBDEs (16 ± 12 pg/m 3 ) were significantly lower than those found in south China, such as in Guangzhou or Hong Kong. On average, the total PBDE concentrations at the urban sites were 2.2 and 2.9 times of those at the rural residential and field sites, respectively. - Graphical abstract: Concentration of PBDEs at each site of the studied area. Highlights: ► High levels of PBDEs with BDE-209 domination were detected in air in northern China. ► PBDE concentrations in rural residential areas were significantly higher than those in rural open fields. ► Proportions of BDE-209 in urban areas were higher than those in rural areas. ► PBDE concentrations were correlated to local population density and Gross Domestic Production. - In northern China, PBDEs in air in rural residential areas were significantly higher than those in open fields.

  13. Role of Phosphate Transport System Component PstB1 in Phosphate Internalization by Nostoc punctiforme.

    Science.gov (United States)

    Hudek, L; Premachandra, D; Webster, W A J; Bräu, L

    2016-11-01

    In bacteria, limited phosphate availability promotes the synthesis of active uptake systems, such as the Pst phosphate transport system. To understand the mechanisms that facilitate phosphate accumulation in the cyanobacterium Nostoc punctiforme, phosphate transport systems were identified, revealing a redundancy of Pst phosphate uptake systems that exists across three distinct operons. Four separate PstB system components were identified. pstB1 was determined to be a suitable target for creating phenotypic mutations that could result in the accumulation of excessive levels of phosphate through its overexpression or in a reduction of the capacity to accumulate phosphate through its deletion. Using quantitative real-time PCR (qPCR), it was determined that pstB1 mRNA levels increased significantly over 64 h in cells cultured in 0 mM added phosphate and decreased significantly in cells exposed to high (12.8 mM) phosphate concentrations compared to the level in cells cultured under normal (0.8 mM) conditions. Possible compensation for the loss of PstB1 was observed when pstB2, pstB3, and pstB4 mRNA levels increased, particularly in cells starved of phosphate. The overexpression of pstB1 increased phosphate uptake by N. punctiforme and was shown to functionally complement the loss of PstB in E. coli PstB knockout (PstB - ) mutants. The knockout of pstB1 in N. punctiforme did not have a significant effect on cellular phosphate accumulation or growth for the most part, which is attributed to the compensation for the loss of PstB1 by alterations in the pstB2, pstB3, and pstB4 mRNA levels. This study provides novel in vivo evidence that PstB1 plays a functional role in phosphate uptake in N. punctiforme IMPORTANCE: Cyanobacteria have been evolving over 3.5 billion years and have become highly adept at growing under limiting nutrient levels. Phosphate is crucial for the survival and prosperity of all organisms. In bacteria, limited phosphate availability promotes the

  14. Translocation of metal phosphate via the phosphate inorganic transport system of Escherichia coli

    NARCIS (Netherlands)

    van Veen, H.W; Abee, T.; Kortstee, G.J J; Konings, W.N; Zehnder, A.J B

    1994-01-01

    P-i transport via the phosphate inorganic transport system (Pit) of Escherichia coil was studied in natural and artificial membranes. P-i uptake via Pit is dependent on the presence of divalent cations, like Mg2+, Ca2+, Co2+, or Mn2+, which form a soluble, neutral metal phosphate (MeHPO(4)) complex.

  15. Isolation and screening phosphate solubilizers from composts as biofertilizer

    International Nuclear Information System (INIS)

    Phua Choo Kwai Hoe; Khairuddin Abdul Rahim; Latiffah Norddin; Abdul Razak Ruslan

    2006-01-01

    Phosphate solubilizers are miroorganisms that able to solubilize insoluble inorganic phosphate compounds or hydrolyze organic phosphate to inorganic P. Therefore make the P to be available for plant and consequently enhance plant growth and yield. Recently, phosphate solubilizing microorganisms has been shown to play an important role in the biofertilizer industry. Fifty-one bacterial were isolated from eleven composts. Most of the phosphate solubilizers were isolated from natural farming composted compost and normal composting compost. This shows that both of these composts are more suitable to use for phosphate solubilizer isolation compare commercial composts. Fourteen of the isolates were found to be phosphate solubilizers. These isolates produced a clear zone on the phosphate agar plates, showing their potential as biofertilizer. AP3 was significantly produced the largest clear zone compared with other isolates. This indicates that isolate AP 3 could be a good phosphate solubilizer. Thus, their effectiveness in the greenhouse and field should be evaluated. (Author)

  16. [Phosphate solubilization of Aureobasidium pullulan F4 and its mechanism].

    Science.gov (United States)

    Wang, Dan; Zhan, Jing; Sun, Qing-Ye

    2014-07-01

    The Aureobasidium pullulans F4 was isolated from the rhizosphere of Hippochaete ramosissimum in Tongguanshan mine wasteland in Tongling City, Anhui Province. Liquid culture was conducted with four kinds of phosphorus sources, calcium phosphate, aluminum phosphate, ferric phosphate and rock phosphate to determine the pH, dissolved phosphorus, phosphorus in the bacteria and organic acid in the solution. The results showed that the phosphate solubilization by A. pullulans F4 varied with phosphorus sources, which decreased in order of aluminum phosphate > ferric phosphate, calcium phosphate > rock phosphate. The amounts of dissolved phosphorus in the different treatments were all higher than 200 mg x L(-1). The pH of the medium dropped immediately in 48 h, and the aluminum phosphate and ferric phosphate treatments showed a greater decrease in pH than the calcium phosphate and rock phosphate treatments. The organic acid synthesized by A. pullulans F4 included oxalic acid, citric acid and tartaric acid, and oxalic acid, among which oxalic acid was the dominated component. The phosphate dissolving capacity of A. pullulans F4 showed no significant correlation with organic acid, but significantly correlated with the pH. The available phosphorus was significantly improved with the combined application of A. pullulans F4 and glucose, suggesting A. pullulans F4 was a potent candidate for remediation of copper mine wastelands.

  17. Removal mechanism of phosphate from aqueous solution by fly ash.

    Science.gov (United States)

    Lu, S G; Bai, S Q; Zhu, L; Shan, H D

    2009-01-15

    This work studied the effectiveness of fly ash in removing phosphate from aqueous solution and its related removal mechanism. The adsorption and precipitation of phosphate by fly ash were investigated separately in order to evaluate their role in the removal of phosphate. Results showed that the removal of phosphate by fly ash was rapid. The removal percentage of phosphate in the first 5min reached 68-96% of the maximum removal of phosphate by fly ash. The removal processes of phosphate by fly ash included a fast and large removal representing precipitation, then a slower and longer removal due to adsorption. The adsorption of phosphate on fly ash could be described well by Freundlich isotherm equation. The pH and Ca2+ concentration of fly ash suspension were decreased with the addition of phosphate, which suggests that calcium phosphate precipitation is a major mechanism of the phosphate removal. Comparison of the relative contribution of the adsorption and precipitation to the total removal of phosphate by fly ash showed that the adsorption accounted for 30-34% of the total removal of phosphate, depending on the content of CaO in fly ash. XRD patterns of the fly ash before and after phosphate adsorption revealed that phosphate salt (CaHPO4 x 2H2O) was formed in the adsorption process. Therefore, the removal of phosphate by fly ash can be attributed to the formation of phosphate precipitation as a brushite and the adsorption on hydroxylated oxides. The results suggested that the use of fly ash could be a promising solution to the removal of phosphate in the wastewater treatment and pollution control.

  18. Structural basis for phosphatidylinositol-phosphate biosynthesis

    Science.gov (United States)

    Clarke, Oliver B.; Tomasek, David; Jorge, Carla D.; Dufrisne, Meagan Belcher; Kim, Minah; Banerjee, Surajit; Rajashankar, Kanagalaghatta R.; Shapiro, Lawrence; Hendrickson, Wayne A.; Santos, Helena; Mancia, Filippo

    2015-10-01

    Phosphatidylinositol is critical for intracellular signalling and anchoring of carbohydrates and proteins to outer cellular membranes. The defining step in phosphatidylinositol biosynthesis is catalysed by CDP-alcohol phosphotransferases, transmembrane enzymes that use CDP-diacylglycerol as donor substrate for this reaction, and either inositol in eukaryotes or inositol phosphate in prokaryotes as the acceptor alcohol. Here we report the structures of a related enzyme, the phosphatidylinositol-phosphate synthase from Renibacterium salmoninarum, with and without bound CDP-diacylglycerol to 3.6 and 2.5 Å resolution, respectively. These structures reveal the location of the acceptor site, and the molecular determinants of substrate specificity and catalysis. Functional characterization of the 40%-identical ortholog from Mycobacterium tuberculosis, a potential target for the development of novel anti-tuberculosis drugs, supports the proposed mechanism of substrate binding and catalysis. This work therefore provides a structural and functional framework to understand the mechanism of phosphatidylinositol-phosphate biosynthesis.

  19. Radionuclide containment in soil by phosphate treatment

    International Nuclear Information System (INIS)

    Lee, S.Y.; Francis, C.W.; Timpson, M.E.; Elless, M.P.

    1995-01-01

    Radionuclide transport from a contaminant source to groundwater and surface water is a common problem faced by most US Department of Energy (DOE) facilities. Containment of the radionuclide plume, including strontium-90 and uranium, is possible using phosphate treatment as a chemical stabilizer. Such a chemical process occurs in soils under natural environmental conditions. Therefore, the concept of phosphate amendment for radiostrontium and uranium immobilization is already a proven principle. In this presentation, results of bench-scale experiments and the concept of a field-scale demonstration are discussed. The phosphate treatment is possible at the source or near the advancing contaminant plume. Cleanup is still the ideal concept; however, containment through stabilization is a more practical and costeffective concept that should be examined by DOE Environmental Restoration programs

  20. Phosphate Phosphors for Solid-State Lighting

    CERN Document Server

    Shinde, Kartik N; Swart, H C; Park, Kyeongsoon

    2012-01-01

    The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

  1. Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs).

    Science.gov (United States)

    Cantón, Rocío F; Scholten, Deborah E A; Marsh, Göran; de Jong, Paul C; van den Berg, Martin

    2008-02-15

    Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC(50) values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent K(i)/K(i)' of 7.68/0,02 microM and 5.01/0.04 microM respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show that a

  2. Elevated Serum Polybrominated Diphenyl Ethers and Alteration of Thyroid Hormones in Children from Guiyu, China

    Science.gov (United States)

    Xu, Xijin; Liu, Junxiao; Zeng, Xiang; Lu, Fangfang; Chen, Aimin; Huo, Xia

    2014-01-01

    Informal electronic waste (e-waste) recycling results in serious environmental pollution of polybrominated diphenyl ethers (PBDEs) and heavy metals. This study explored whether there is an association between PBDEs, heavy metal and key growth- and development-related hormones in children from Guiyu, an e-waste area in southern China. We quantified eight PBDE congeners using gas chromatographic mass spectrometry, lead and cadmium utilizing graphite furnace atomic absorption spectrometry, three thyroids with radioimmunoassay and two types of growth hormones by an enzyme-linked immune-sorbent assay (ELISA) in 162 children, 4 to 6 years old, from Guiyu. In blood, median total PBDE was 189.99 ng/g lipid. Lead and cadmium concentrations in blood averaged 14.53±4.85 µg dL−1 and 0.77±0.35 µg L−1, respectively. Spearman partial correlation analysis illustrated that lead was positively correlated with BDE153 and BDE183. Thyroid-stimulating hormone (TSH) was positively correlated with almost all PBDE congeners and negatively correlated with insulin-like growth factor binding protein-3 (IGFBP-3), whereas free triiodothyronine (FT3) and free thyroxine (FT4) were negatively correlated with BDE154. However, no correlation between the hormones and blood lead or cadmium levels was found in this study. Adjusted multiple linear regression analysis showed that total PBDEs was negatively associated with FT3 and positively associated with TSH. Notably, FT4 was positively correlated with FT3, house functions as a workshop, and father's work involved in e-waste recycling and negatively correlated with vitamin consumptions. TSH was negatively related with FT4, paternal residence time in Guiyu, working hours of mother, and child bean products intake. IGFBP-3 was positively correlated with IGF-1 and house close to an e-waste dump. These results suggest that elevated PBDEs and heavy metals related to e-waste in Guiyu may be important risk factors for hormone alterations in children

  3. Polybrominated diphenyl ethers and polychlorinated biphenyls in human adipose tissue from New York.

    Science.gov (United States)

    Johnson-Restrepo, Boris; Kannan, Kurunthachalam; Rapaport, David P; Rodan, Bruce D

    2005-07-15

    Human adipose tissue samples (n=52) collected in New York City during 2003-2004 were analyzed for the presence of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs). Concentrations of PBDEs in adipose tissues ranged from 17 to 9630 ng/g, lipid wt (median: 77; mean: 399 ng/g, lipid wt; sum all di- through hexaBDE congeners). Average PBDE concentrations in human adipose tissues from New York City were 10- to 100-times greater than those reported for European countries. A concentration of 9630 ng/g, lipid wt, found in a sample of adipose tissue, is one of the highest concentrations reported to date. PBDE 47 (2,2',4,4'-tetraBDE) was the major congener detected in human tissues, followed by PBDE congeners #99 (2,2',4,4',5-penta BDE), 100 (2,2',4,4',6-pentaBDE), and 153 (2,2',4,4',5,5'-hexaBDE). A few individuals contained PBDE 153 as the predominant congener in total PBDE concentrations, suggesting alternative exposure sources, possibly occupational. Principal component analysis of PBDE congener composition in human adipose tissues revealed the presence of five clusters, each characterized by varying composition. No significant difference was found in the concentrations of PBDEs between gender. Concentrations of PBDEs were, on average, similar to those for PCBs in human adipose tissues, and substantially higher when PBDE outliers were retained. PBDE and PCB concentrations were not correlated. PBDE concentrations did not increase with increasing age of the subjects, whereas concentrations of PCBs increased with increasing age in males but not in females in this study. These results suggest differences between PBDEs and PCBs in their sources or time course of exposure and disposition. The presence of comparable or greater concentrations of PBDEs, relative to PCBs, highlights the importance of recentvoluntary and regulatory effortsto cease production of commercial penta- and octa-BDE in North America, although these efforts do not address

  4. Baseline Studies of Selected Polybrominated Diphenyl Ethers in the Air of the Nandamojo Watershed, Costa Rica

    Science.gov (United States)

    Geesey, Mary Sophia

    Polybrominated diphenyl ethers (PBDEs) have been used as flame retardants in a number of common household and commercial products around the world. PBDEs enter the environment in a variety of ways, such as through emissions, leaching from end-of-life electronics in landfills, and incineration. While many countries have phased out the manufacturing of penta-, octa-, and deca-PBDEs or have banned the manufacture and use of these congeners altogether, these persistent organic pollutants (POPs) continue to be detected in humans and the environment. This study investigates spatial and temporal variations of selected PBDEs in the air of the Nandamojo watershed area in Costa Rica by comparing air concentrations of PBDEs in the dry winter vs. wet summer seasons and rural vs. urban areas and also investigates the impact of anthropogenic activities on air concentration of PBDEs. This study is significant to the field, because there are no baseline studies nor are there currently any monitoring programs to assess the environmental levels of PBDEs or other POPs for this region of the Guanacaste province. Baseline information is needed to track spatial and temporal trends as well as evaluate the effectiveness of control measures employed nationally and internationally. Samples obtained from passive air sampling devices were analyzed via GC/MS for a number of congeners. PBDE-47 and -99 were found to be the congeners present in greatest concentration in air samples from the Nandamojo watershed area. Air concentrations were estimated assuming an average sampler uptake rate of 3.5 m3/day and ranged as follows: SigmaPBDE5 35.20-1549.25 pg/m3 over the entire study. The presence of PBDEs in remote and pristine environments indicates that PBDEs are now a global concern. This study suggests that the spatial and temporal distribution patterns observed are strongly related to anthropogenic activities and presence of a population similar to that observed in other studies. The presence of

  5. Levels of dechloranes and polybrominated diphenyl ethers (PBDEs) in human serum from France.

    Science.gov (United States)

    Brasseur, Catherine; Pirard, Catherine; Scholl, Georges; De Pauw, Edwin; Viel, Jean-François; Shen, Li; Reiner, Eric J; Focant, Jean-François

    2014-04-01

    Human exposure to dechloranes has been evaluated in Western Europe (France) with the analysis of Dechlorane Plus (DP), Dechloranes (Dec) 602, 603 and 604, Chlordene Plus (CP) and Mirex in 48 serum samples collected between 2003 and 2005. While no production source has been identified in Europe until now, detection frequencies for all investigated dechloranes were high, except for Dec 604 which was below detection limit for all samples. The mean DP concentration was 1.40±1.40ng/g lipid weight (lw), lower than levels reported in serum from Chinese population, but higher than levels reported in Canadian human milk. To the best of our knowledge, this is the first time that ∑5dechlorane levels are reported for human serum. A specific pattern of contamination was found (Dec 603>DP>Mirex>Dec 602>CP) compared to other biota samples that have been analyzed from Europe, with Dec 603 as the most abundant dechlorane (mean level: 2.61±2.63ng/g lw). Dec 603 and CP levels were correlated with age and with levels of some bioaccumulative organochlorine pesticides (OCPs). These results indicate that bioaccumulation properties should be further investigated and taken in consideration when assessing human exposure to dechloranes. For comparison purposes, polybrominated diphenyl ether (PBDE) levels were also measured for BDE-47, -99, -100, -153 and -154 in the serum samples. As expected, BDE-47 and BDE-153 were the major congeners with mean levels of 2.06±1.80ng/g lw and 1.39±0.97ng/g lw, respectively. The mean ∑5PBDE levels (4.32±2.99ng/g lw) were in the range typical of Western Europe levels, but lower than the mean ∑5dechlorane levels (6.24±4.16ng/g lw). These results indicate that the attention to dechloranes should be continued if research indicates toxicological concerns. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Inhibition of human placental aromatase activity by hydroxylated polybrominated diphenyl ethers (OH-PBDEs)

    International Nuclear Information System (INIS)

    Canton, Rocio F.; Scholten, Deborah E.A.; Marsh, Goeran; Jong, Paul C. de; Berg, Martin van den

    2008-01-01

    Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants in many different polymers, resins and substrates. Due to their widespread production and use, their high binding affinity to particles, and their lipophilic properties, several PBDE congeners can bioaccumulate in the environment. As a result, PBDEs and their hydroxylated metabolites (OH-PBDEs) have been detected in humans and various wildlife samples, such as birds, seals, and whales. Furthermore, certain OH-PBDEs and their methoxylated derivatives (MeO-PBDEs) are natural products in the marine environment. Recently, our laboratory focused on the possible effects on steroidogenesis of PBDEs and OH-PBDEs, e.g. in the human adrenocortical carcinoma (H295R) cell line indicating that some OH-PBDEs can significantly influence steroidogenic enzymes like CYP19 (aromatase) and CYP17. In the present study, human placental microsomes have been used to study the possible interaction of twenty two OH-PBDEs and MeO-PBDEs with aromatase, the enzyme that mediates the conversion of androgens into estrogens. All OH-PBDE derivates showed significant inhibition of placental aromatase activity with IC 50 values in the low micromolar range, while the MeO-PBDEs did not have any effect on this enzyme activity. Enzyme kinetics studies indicated that two OH-PBDEs, 5-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (5-OH-BDE47) and 6-hydroxy-2,2',4,4'-tetrabromodiphenyl ether (6-OH-BDE47), had a mixed-type inhibition of aromatase activity with apparent K i /K i ' of 7.68/0,02 μM and 5.01/0.04 μM respectively. For comparison, some structurally related compounds, a dihydroxylated polybrominated biphenyl, which is a natural product (2,2'-dihyroxy-3,3',5,5'-tetrabromobiphenyl (2,2'-diOH-BB80)) and its non-bromo derivative were also included in the study. Again inhibition of aromatase activity could be measured, but their potency was significantly less than those observed for the OH-PBDEs. These results show that a wide

  7. Polybrominated diphenyl ether levels in foodstuffs collected from three locations from the United States

    International Nuclear Information System (INIS)

    Schecter, Arnold; Colacino, Justin; Patel, Keyur; Kannan, Kurunthachalam; Yun, Se Hun; Haffner, Darrah; Harris, T. Robert; Birnbaum, Linda

    2010-01-01

    Objectives: The objectives of this study were to provide updated measurements of PBDEs in US food, to estimate possible difference in levels from differing geographical regions, and to provide an improved estimate of current dietary intake. Methods: Thirty matched food samples for a total of 90 samples were collected from each of three cities (Los Angeles, California; Dallas, Texas; and Albany, New York) and were analyzed for 13 polybrominated diphenyl ether congeners (BDE 28, 47, 49, 66, 85, 99, 100, 138, 153, 154, 183, 203, and 209). Dietary intake of PBDEs was estimated by food type, age, and sex. Results: In this pilot study, we did not note a statistically significant difference in total PBDE levels in food collected from the three locations. The median total PBDE levels (estimating non-detected values as half of the detection limit) in meat, dairy, eggs, and fish were 267 pg/g wet weight (ww) (range 102-3156 pg/g ww), 176 pg/g ww (range 41-954 pg/g ww), 637 pg/g ww (range 193-932 pg/g ww), and 243 pg/g ww (range 36-2161 pg/g ww). PBDE intake from food was estimated to range from 2.7 ng/kg/day for children 2 through 5 years of age to 0.8 ng/kg/day for women aged 60 years and older. This compares closely with our previous study where the intake estimate was 2.7 ng/kg/day for children 2 through 5 years of age and 0.9 ng/kg/day for women aged 60 years and older. Conclusion: We did not find a decrease of PBDEs in food since our previous studies which we expected to find due to the declining use of PBDEs in the USA. These findings could be consistent with food contamination from depot sources of PBDEs. A larger, more representative sampling of the US food supply is indicated based on our findings.

  8. Atmospheric concentrations of organochlorine pesticides, polybrominated diphenyl ethers and polychloronaphthalenes in Nuuk, South-West Greenland

    Science.gov (United States)

    Bossi, Rossana; Skov, Henrik; Vorkamp, Katrin; Christensen, Jesper; Rastogi, Suresh C.; Egeløv, Axel; Petersen, Dorthe

    Atmospheric concentrations of organochlorine pesticides (OCs), polybrominated diphenyl ethers (PBDEs) and polychloronaphthalenes (PCNs) were measured for the first time in Nuuk, Greenland in 2004 and 2005. The annual mean concentrations of the measured OCs were: α-HCH 20.2 pg m -3, γ-HCH (lindane) 5.1 pg m -3, endosulfan 4.8 pg m -3 and dieldrin 1.9 pg m -3. Concentrations of Σ-chlordanes, DDEs and heptachlor epoxide were generally similar and lower than those of α-HCH and γ-HCH. The concentrations of most chlorinated pesticides did not show any clear seasonal variation, with the exception of γ-HCH, which had maximum concentration in August in both years. The average annual mean for ΣPBDEs was 1.14 ± 0.81 pg m -3. The predominant congeners measured in Nuuk were BDE-47 and BDE-99 followed by BDE-100, -153 and -28, indicating the use of penta-BDE technical products as the main source. A clear seasonal variation of PBDE concentrations was observed with maximum concentrations occurring in the summer months. The ΣPCNs concentrations ranged between 0.062 and 0.258 pg m -3 with an annual mean concentration of 0.161 ± 0.004 pg m -3. The PCNs profile was dominated by the tetra-PCNs (74% of the annual mean) and the penta-PCNs (18% of the annual mean). A seasonal trend for ΣPCNs was not observed. Atmospheric concentrations of the investigated compounds were correlated with temperature and anthropogenic CO in order to obtain information about their transport pattern. Positive correlations were found between CO and chlordanes, p, p'-DDE and trifluralin, while a negative correlation was found for γ-HCH. A significant correlation with temperature variations was found for dieldrin, heptachlor epoxide, α-HCH, γ-HCH, BDE-47, BDE-99 and tetra-PCNs, which indicates that re-emission of these compounds from previously contaminated surfaces as an important factor for the observed variations in concentrations.

  9. Dietary accumulation and metabolism of polybrominated diphenyl ethers by juvenile carp (Cyprinus carpio).

    Science.gov (United States)

    Stapleton, Heather M; Letcher, Robert J; Li, Juliana; Baker, Joel E

    2004-08-01

    Polybrominated diphenyl ethers (PBDEs) are hydrophobic organic contaminants with properties and nomenclature similar to polychlorinated biphenyls (PCBs). While much information is available on the bioaccumulation and pharamcokinetics of PCBs, little information is available on PBDEs. In this study, juvenile carp were exposed to a diet spiked with a cocktail of four BDE congeners (2,4,4'-tribromoDE [BDE 28], 2,2',4,4'-tetrabromoDE [BDE 47], 2,2',4,4',5-pentabromoDE [BDE 99], and 2,2',4,4',5,5'hexabromoDE [BDE 153]) for 60 d followed by a 40-d depuration period. As a positive control, three PCB congeners with similar log K(ow), values (2,2',5,5'-tetrachlorobiphenyl [PCB 52], 2,2',4,4', 5,5'-hexachlorobiphenyl [PCB 153], and 2,2',3,4,4',5,5'-heptachlorobiphenyl [PCB 180]) were included in the cocktail to compare their assimilation and fate with the model BDE congeners. Concentrations of BDEs and PCBs were monitored in whole-fish tissues and liver tissues over the duration of the experiment. In addition, blood serum samples were taken and pooled among replicates to determine if any phenolic metabolites of BDE and PCBs were formed. Rapid assimilation of BDE 47 was observed relative to all other BDE and PCB congeners, whereas apparently no accumulation of BDE 99 occurred over the course of the experiment. Assimilation efficiencies for BDE 47 suggest that approximately 100% of the BDE 47 exposure was absorbed by carp tissues after 60 d. However, based on the time course of BDE 47 assimilation, it is improbable that all BDE 47 was assimilated; more likely, production of BDE 47 in carp tissues occurred as a result of debromination of higher-brominated compounds, possibly BDE 99. The net assimilation efficiencies of BDE 28 and BDE 153 were also apparently low (20 and 4%, respectively) relative to the three PCBs (40% assimilated) examined in this study. The low assimilation efficiency and high depuration rates for BDEs suggest a higher potential for biotransformation. While

  10. Occurrence and levels of polybrominated diphenyl ethers in surface sediments from the Yellow River Estuary, China

    International Nuclear Information System (INIS)

    Yuan, Zijiao; Liu, Guijian; Lam, Michael Hon Wah; Liu, Houqi; Da, Chunnian

    2016-01-01

    A total of 21 surface sediments collected from the Yellow River Estuary, China were analyzed for 40 kinds of polybrominated diphenyl ethers (PBDEs) using gas chromatography-mass spectrometry (GC–MS). Their levels, spatial distribution, congener profiles and possible sources were investigated. Only ten congeners were detected in the sediments. The total concentrations of the lower brominated BDEs (∑PBDEs_l_o_w_, PBDEs excluding BDE 209) and BDE 209 ranged from 0.482 ng/g to 1.07 ng/g and 1.16–5.40 ng/g, with an average value of 0.690 and 2.79 ng/g, respectively, which were both at the low end of the global contamination level. The congener profiles were dominated by BDE 209, with the average value accounting for 79.2% of the total PBDEs in the sediment samples. Among the nine lower brominated BDE congeners, BDE 47, 99 and 183 had high abundances. Although the commercial Penta/Octa-BDE products have been banned in most countries, the residual commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds such as BDE 209 were still found to be the possible sources for the trace level of PBDEs in the present study area. In spite of the gradual removal of the commercial PBDEs in the world, the present research results further suggested that scientific attention should not be reduced on the issue of environmental contamination caused by these outdated chemical compounds. - Highlights: • This is the first study concentrating specifically on PBDEs in the study area. • The commercial Penta/Octa/Deca-BDE products were the possible sources. • The debromination of highly brominated PBDEs were also found to be the sources. • Scientific attention should not be reduced on these outdated chemical compounds. - The commercial Penta/Octa/Deca-BDE products and the debromination of highly brominated BDE compounds were found to be the possible sources.

  11. Polybrominated diphenyl ethers (PBDEs) in leachates from selected landfill sites in South Africa.

    Science.gov (United States)

    Odusanya, David O; Okonkwo, Jonathan O; Botha, Ben

    2009-01-01

    The last few decades have seen dramatic growth in the scale of production and the use of polybrominated diphenyl ethers (PBDEs) as flame retardants. Consequently, PBDEs such as BDE -28, -47, -66, -71, -75, -77, -85, -99, -100, -119, -138, -153, -154, and -183 have been detected in various environmental matrices. Generally, in South Africa, once the products containing these chemicals have outlived their usefulness, they are discarded into landfill sites. Consequently, the levels of PBDEs in leachates from landfill sites may give an indication of the general exposure and use of these compounds. The present study was aimed at determining the occurrence and concentrations of most common PBDEs in leachates from selected landfill sites. The extraction capacities of the solvents were also tested. Spiked landfill leachate samples were used for the recovery tests. Separation and determination of the PBDE congeners were carried out with a gas chromatograph equipped with Ni63 electron capture detector. The mean percentage recoveries ranged from 63% to 108% (n=3) for landfill leachate samples with petroleum ether giving the highest percentage extraction. The mean concentrations of PBDEs obtained ranged from ND to 2670pgl(-1), ND to 6638pgl(-1), ND to 7230pgl(-1), 41 to 4009pgl(-1), 90 to 9793pgl(-1) for the Garankuwa, Hatherly, Kwaggarsrand, Soshanguve and Temba landfill sites, respectively. Also BDE -28, -47, -71 and BDE-77 were detected in the leachate samples from all the landfill sites; and all the congeners were detected in two of the oldest landfill sites. The peak concentrations were recorded for BDE-47 at three sites and BDE-71 and BDE-75 at two sites. The highest concentration, 9793+/-1.5pgl(-1), was obtained for the Temba landfill site with the highest BOD value. This may suggest some influence of organics on the level of PBDEs. Considering the leaching characteristics of brominated flame retardants, there is a high possibility that with time these compounds may

  12. Polybrominated diphenyl ethers (PBDEs) in leachates from selected landfill sites in South Africa

    International Nuclear Information System (INIS)

    Odusanya, David O.; Okonkwo, Jonathan O.; Botha, Ben

    2009-01-01

    The last few decades have seen dramatic growth in the scale of production and the use of polybrominated diphenyl ethers (PBDEs) as flame retardants. Consequently, PBDEs such as BDE -28, -47, -66, -71, -75, -77, -85, -99, -100, -119, -138, -153, -154, and -183 have been detected in various environmental matrices. Generally, in South Africa, once the products containing these chemicals have outlived their usefulness, they are discarded into landfill sites. Consequently, the levels of PBDEs in leachates from landfill sites may give an indication of the general exposure and use of these compounds. The present study was aimed at determining the occurrence and concentrations of most common PBDEs in leachates from selected landfill sites. The extraction capacities of the solvents were also tested. Spiked landfill leachate samples were used for the recovery tests. Separation and determination of the PBDE congeners were carried out with a gas chromatograph equipped with Ni 63 electron capture detector. The mean percentage recoveries ranged from 63% to 108% (n = 3) for landfill leachate samples with petroleum ether giving the highest percentage extraction. The mean concentrations of PBDEs obtained ranged from ND to 2670 pg l -1 , ND to 6638 pg l -1 , ND to 7230 pg l -1 , 41 to 4009 pg l -1 , 90 to 9793 pg l -1 for the Garankuwa, Hatherly, Kwaggarsrand, Soshanguve and Temba landfill sites, respectively. Also BDE -28, -47, -71 and BDE-77 were detected in the leachate samples from all the landfill sites; and all the congeners were detected in two of the oldest landfill sites. The peak concentrations were recorded for BDE-47 at three sites and BDE-71 and BDE-75 at two sites. The highest concentration, 9793 ± 1.5 pg l -1 , was obtained for the Temba landfill site with the highest BOD value. This may suggest some influence of organics on the level of PBDEs. Considering the leaching characteristics of brominated flame retardants, there is a high possibility that with time these

  13. Presence of polybrominated diphenyl ethers in Spanish sewage sludges. Important contribution of deca-BDE

    Energy Technology Data Exchange (ETDEWEB)

    Fabrellas, B.; Larrazabal, D.; Martinez, M.A. [CIEMAT, Madrid (Spain); Eljarrat, E.; Barcelo, D. [I.I.Q.A.B., C.S.I.C, Barcelona (Spain)

    2004-09-15

    Introduction Polybrominated diphenyl ethers (PBDE) are a family of synthetic chemicals widely used in industry to delay, inhibit or even suppress combustion process in manufactured items. Flame retardant products are frequently added into plastic, electronic, paint and textile materials to reduce the risk of ignition. During last years, increasing levels of PBDE have been detected in the environment, suggesting release from the treated surface as main pathway for environmental intake. Their physicochemical structure make them substances of highly lypophylic, bioaccumulative and persistent nature, with potential toxic effects observed onto wildlife and humans. Some European countries (Switzerland and Sweden) have promoted strategies to enlarge the knowledge of PBDE, in particular their occurrence and levels on sewage sludge. Observations point domestic washing of garment/clothes and industrial discharges from plastic and textile manufacture industry as major sources of contamination. First European results from 1988 revealed levels of about 20-30 {mu}g/kg dw of PBDEs (BDEs 47, 99 and 100) in sludge samples collected in Sweden. More recently, another Swedish survey conducted on three waste-water treatment facilities pointed levels of PBDE (BDE 47, 99 and 209) of about 200 ng/g dw, along with minor contribution of other contaminants such as TBBPA and HBCD iv. Few studies have been carried out in US. Hale et al. compared levels of Tetra-, PentaBDE (BDE 47, BDE 99 and BDE 100) and DecaBDE 209 congeners in sludge from different US locations. Values ranged from 1000 to 2290 {mu}g/kg dw (Tri- to HexaBDE) and from 84 to 4890 {mu}g/kg dw for DecaBDE 209, with mean values of about 1600 and 1000 {mu}g/kg dw, respectively. In general, concentrations of BDE 47, 99, 100 and 209 exceeded those of the major PCB congeners and other halogenated contaminants also found in the sludge. Following this trend, this work aims a preliminary assessment of selected PBDE congener levels on

  14. Prenatal and postnatal polybrominated diphenyl ether exposure and visual spatial abilities in children

    Energy Technology Data Exchange (ETDEWEB)

    Vuong, Ann M. [Division of Epidemiology, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States); Braun, Joseph M. [Department of Epidemiology, Brown University School of Public Health, Providence, RI (United States); Yolton, Kimberly [Division of General and Community Pediatrics, Department of Pediatrics, Cincinnati Children' s Hospital Medical Center, Cincinnati, OH (United States); Xie, Changchun [Division of Biostatistics and Bioinformatics, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States); Webster, Glenys M. [BC Children' s Hospital Research Institute, Simon Fraser University, Vancouver, British Columbia (Canada); Sjödin, Andreas [Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA (United States); Dietrich, Kim N. [Division of Epidemiology, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States); Lanphear, Bruce P. [BC Children' s Hospital Research Institute, Simon Fraser University, Vancouver, British Columbia (Canada); Chen, Aimin, E-mail: aimin.chen@uc.edu [Division of Epidemiology, Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, OH (United States)

    2017-02-15

    Polybrominated diphenyl ethers (PBDEs) are associated with impaired visual spatial abilities in toxicological studies, but no epidemiologic study has investigated PBDEs and visual spatial abilities in children. The Health Outcomes and Measures of the Environment Study, a prospective birth cohort (2003–2006, Cincinnati, OH), was used to examine prenatal and childhood PBDEs and visual spatial abilities in 199 children. PBDEs were measured at 16±3 weeks gestation and at 1, 2, 3, 5, and 8 years using gas chromatography/isotope dilution high-resolution mass spectrometry. We used the Virtual Morris Water Maze to measure visual spatial abilities at 8 years. In covariate-adjusted models, 10-fold increases in BDE-47, −99, and −100 at 5 years were associated with shorter completion times by 5.2 s (95% Confidence Interval [CI] −9.3, −1.1), 4.5 s (95% CI −8.1, −0.9), and 4.7 s (95% CI −9.0, −0.3), respectively. However, children with higher BDE-153 at 3 years had longer completion times (β=5.4 s, 95% CI −0.3, 11.1). Prenatal PBDEs were associated with improved visual spatial memory retention, with children spending a higher percentage of their search path in the correct quadrant. Child sex modified some associations between PBDEs and visual spatial learning. Longer path lengths were observed among males with increased BDE-47 at 2 and 3 years, while females had shorter paths. In conclusion, prenatal and postnatal BDE-28, −47, −99, and −100 at 5 and 8 years were associated with improved visual spatial abilities, whereas a pattern of impairments in visual spatial learning was noted with early childhood BDE-153 concentrations. - Highlights: • The VMWM test was used to assess visual spatial abilities in children at 8 years. • BDE-153 at 3 years was adversely associated with visual spatial learning. • BDE-47, −99, and −100 at 5 years was associated with better visual spatial learning. • Prenatal PBDEs were associated with improved visual

  15. [Indoor dust as a pathway of human exposure to polybrominated diphenyl ethers (PBDEs)].

    Science.gov (United States)

    Góralczyk, Katarzyna; Struciński, Paweł; Hernik, Agnieszka; Czaja, Katarzyna; Korcz, Wojciech; Minorczyk, Maria; Ludwicki, Jan K

    2012-01-01

    The brominated diphenyl ethers (PBDEs) belong to a class of synthetic, additive brominated flame retardants (BFRs). PBDEs are used to reduce the flammability of commercial and household products such as textiles, various plastic polymers, furnishing foam, and electronic equipment. People spend a large percentage of their life-time indoors at home, in offices and cars, etc, providing many opportunities for lengthy exposure to PBDEs from residential settings and commercial products in an indoor environment. In recent time, the foodstuffs, mainly food of animal origin, have been indicated as the main pathway of human exposure to PBDEs. However, many studies have shown that the indoor environment, mainly indoor dust, can be also a significant source of exposure to PBDEs, especially for younger children (toddlers) because of their behavioral patterns, eg. putting fingers, toys, and other items in their mouth. Numerous studies show that the median intakes of PBDEs via dust for adult range from 1.41 to 277 ng x day(-1) is lower than that via food which range from 135 to 333 ng x day-', while the median intake of these compounds via indoor dust for children range from 101 to 404 ng x day(-1) is much higher than via food: 77-190 ng x day(-1). The congener pattern observed in the indoor dust is different to that found in food. The indoor dust is dominated by the congener BDE-209 vs. food where the most dominated congeners are BDE-47 and BDE-99. Human exposure to PBDEs and other brominated flame retardants (BFRs) is widely widespread throughout the world and it depends on a country range of usage, production and legislation concerning these chemicals as well as a citizen's behavior. Generally, human exposure has been found higher in North America than in Europe and Asia. Within European countries the significant highest concentrations in dust have been found in the United Kingdom. It should be noted that many uncertainty factors such as personal habits, dietary preferences

  16. Prenatal and postnatal polybrominated diphenyl ether exposure and visual spatial abilities in children

    International Nuclear Information System (INIS)

    Vuong, Ann M.; Braun, Joseph M.; Yolton, Kimberly; Xie, Changchun; Webster, Glenys M.; Sjödin, Andreas; Dietrich, Kim N.; Lanphear, Bruce P.; Chen, Aimin

    2017-01-01

    Polybrominated diphenyl ethers (PBDEs) are associated with impaired visual spatial abilities in toxicological studies, but no epidemiologic study has investigated PBDEs and visual spatial abilities in children. The Health Outcomes and Measures of the Environment Study, a prospective birth cohort (2003–2006, Cincinnati, OH), was used to examine prenatal and childhood PBDEs and visual spatial abilities in 199 children. PBDEs were measured at 16±3 weeks gestation and at 1, 2, 3, 5, and 8 years using gas chromatography/isotope dilution high-resolution mass spectrometry. We used the Virtual Morris Water Maze to measure visual spatial abilities at 8 years. In covariate-adjusted models, 10-fold increases in BDE-47, −99, and −100 at 5 years were associated with shorter completion times by 5.2 s (95% Confidence Interval [CI] −9.3, −1.1), 4.5 s (95% CI −8.1, −0.9), and 4.7 s (95% CI −9.0, −0.3), respectively. However, children with higher BDE-153 at 3 years had longer completion times (β=5.4 s, 95% CI −0.3, 11.1). Prenatal PBDEs were associated with improved visual spatial memory retention, with children spending a higher percentage of their search path in the correct quadrant. Child sex modified some associations between PBDEs and visual spatial learning. Longer path lengths were observed among males with increased BDE-47 at 2 and 3 years, while females had shorter paths. In conclusion, prenatal and postnatal BDE-28, −47, −99, and −100 at 5 and 8 years were associated with improved visual spatial abilities, whereas a pattern of impairments in visual spatial learning was noted with early childhood BDE-153 concentrations. - Highlights: • The VMWM test was used to assess visual spatial abilities in children at 8 years. • BDE-153 at 3 years was adversely associated with visual spatial learning. • BDE-47, −99, and −100 at 5 years was associated with better visual spatial learning. • Prenatal PBDEs were associated with improved visual

  17. Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Mohamed F. Abdel-Megeed

    2013-01-01

    Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

  18. Application of vanadium incorporated phosphomolybdate supported on the modified kaolinin synthesis of diphenyl carbonate by oxidative carbonylation with phenol

    Directory of Open Access Journals (Sweden)

    Peng Meng

    2017-01-01

    Full Text Available Keggin-type molybdophosphoric acid, molybdophosphoric salt and vanadium incorporated molybdophosphoric salt supported on the modified kaolin (MK were investigated as redox co-catalysts for the oxidative carbonylation of phenol to diphenyl carbonate (DPC in the absence of solvent. The 20 wt.% of MnAMPV5 (one kind of vanadium incorporated molybdophosphoric salt loaded on MK showed the highest catalytic activity with the yield of 24.68% and a TON of 306, while the selectivity amounts to nearly 100% in all the carbonylation reactions. The catalysts were characterized by XRD, BET, XPS and H2-TPR. The reusability study showed that the catalysts were stable and active.

  19. Thiophene-free diphenyl-amino-stilbene-diketo-pyrrolo-pyrrole derivatives as donors for organic bulk heterojunction solar cell

    Czech Academy of Sciences Publication Activity Database

    Honová, J.; Luňák, S.; Vala, M.; Stříteský, S.; Fekete, Ladislav; Weiter, M.; Kovalenko, A.

    2016-01-01

    Roč. 70, č. 10 (2016), s. 1416-1424 ISSN 0366-6352 R&D Projects: GA MŠk LO1409; GA ČR(CZ) GA15-05095S; GA MŠk LM2015088 Institutional support: RVO:68378271 Keywords : organic solar cell * thiophene-free * diphenyl-amino-stilbene * hole mobility * molecular structure Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.258, year: 2016

  20. Monte Carlo Simulations of Phosphate Polyhedron Connectivity in Glasses

    Energy Technology Data Exchange (ETDEWEB)

    ALAM,TODD M.

    1999-12-21

    Monte Carlo simulations of phosphate tetrahedron connectivity distributions in alkali and alkaline earth phosphate glasses are reported. By utilizing a discrete bond model, the distribution of next-nearest neighbor connectivities between phosphate polyhedron for random, alternating and clustering bonding scenarios was evaluated as a function of the relative bond energy difference. The simulated distributions are compared to experimentally observed connectivities reported for solid-state two-dimensional exchange and double-quantum NMR experiments of phosphate glasses. These Monte Carlo simulations demonstrate that the polyhedron connectivity is best described by a random distribution in lithium phosphate and calcium phosphate glasses.

  1. Method of decomposing treatment for radioactive organic phosphate wastes

    International Nuclear Information System (INIS)

    Uki, Kazuo; Ichihashi, Toshio; Hasegawa, Akira; Sato, Tatsuaki

    1985-01-01

    Purpose: To decompose the organic phosphoric-acid ester wastes containing radioactive material, which is produced from spent fuel reprocessing facilities, into inorganic materials using a simple device, under moderate conditions and at high decomposing ratio. Method: Radioactive organic phosphate wates are oxidatively decomposed by H 2 O 2 in an aqueous phosphoric-acid solution of metal phosphate salts. Copper phosphates are used as the metal phosphate salts and the decomposed solution of the radioactive organic phosphate wastes is used as the aqueous solution of the copper phosphate. The temperature used for the oxidizing decomposition ranges from 80 to 100 0 C. (Ikeda, J.)

  2. Synthesis of β-tricalcium phosphate.

    Science.gov (United States)

    Chaair, H; Labjar, H; Britel, O

    2017-09-01

    Ceramics play a key role in several biomedical applications. One of them is bone grafting, which is used for treating bone defects caused by injuries or osteoporosis. Calcium-phosphate based ceramic are preferred as bone graft biomaterials in hard tissue surgery because their chemical composition is close to the composition of human bone. They also have a marked bioresorbability and bioactivity. In this work, we have developed methods for synthesis of β-tricalcium phosphate apatite (β-TCP). These products were characterized by different techniques such as X-ray diffraction, infrared spectroscopy, scanning electron microscopy and chemical analysis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Potentially Prebiotic Syntheses of Condensed Phosphates

    Science.gov (United States)

    Keefe, Anthony D.; Miller, Stanley L.

    1996-01-01

    In view of the importance of a prebiotic source of high energy phosphates, we have investigated a number of potentially prebiotic processes to produce condensed phosphates from orthophosphate and cyclic trimetaphosphate from tripolyphosphate. The reagents investigated include polymerizing nitriles, acid anhydrides, lactones, hexamethylene tetramine and carbon suboxide. A number of these processes give substantial yields of pyrophosphate from orthophosphate and trimetaphosphate from tripolyphosphate. Although these reactions may have been applicable in local areas, they are not sufficiently robust to have been of importance in the prebiotic open ocean.

  4. Automated back titration method to measure phosphate

    International Nuclear Information System (INIS)

    Comer, J.; Tehrani, M.; Avdeef, A.; Ross, J. Jr.

    1987-01-01

    Phosphate was measured in soda drinks and as an additive in flour, by a back titration method in which phosphate was precipitated with lanthanum, and the excess lanthanum was titrated with fluoride. All measurements were performed using the Orion fluoride electrode and the Orion 960 Autochemistry System. In most commercial automatic titrators, the inflection point of the titration curve, calculated from the first derivative of the curve, is used to find the equivalence polar of the titration. The inflection technique is compared with a technique based on Gran functions, which uses data collected after the end point and predicts the equivalence point accordingly

  5. Calcium phosphate ceramics in drug delivery

    Science.gov (United States)

    Bose, Susmita; Tarafder, Solaiman; Edgington, Joe; Bandyopadhyay, Amit

    2011-04-01

    Calcium phosphate (CaP) particulates, cements and scaffolds have attracted significant interest as drug delivery vehicles. CaP systems, including both hydroxyapaptite and tricalcium phosphates, possess variable stoichiometry, functionality and dissolution properties which make them suitable for cellular delivery. Their chemical similarity to bone and thus biocompatibility, as well as variable surface charge density contribute to their controlled release properties. Among specific research areas, nanoparticle size, morphology, surface area due to porosity, and chemistry controlled release kinetics are the most active. This article discusses CaP systems in their particulate, cements, and scaffold forms for drug, protein, and growth factor delivery toward orthopedic and dental applications.

  6. Performance of pineapple slips inoculated with diazotrophic phosphate-solubilizing bacteria and rock phosphate

    Directory of Open Access Journals (Sweden)

    Lílian Estrela Borges Baldotto

    2014-06-01

    Full Text Available Besides fixing N2, some diazotrophic bacteria or diazotrophs, also synthesize organic acids and are able to solubilize rock phosphates, increasing the availability of P for plants. The application of these bacteria to pineapple leaf axils in combination with rock phosphate could increase N and P availability for the crop, due to the bacterial activity of biological nitrogen fixation and phosphate solubilization. The objectives of this study were: (i to select and characterize diazotrophs able to solubilize phosphates in vitro and (ii evaluate the initial performance of the pineapple cultivars Imperial and Pérola in response to inoculation with selected bacteria in combination with rock phosphate. The experiments were conducted at Universidade Estadual do Norte Fluminense Darcy Ribeiro, in 2009. In the treatments with bacteria the leaf contents of N, P and K were higher than those of the controls, followed by an increase in plant growth. These results indicate that the combined application of diazotrophic phosphate-solubilizing bacteria Burkholderia together with Araxá rock phosphate can be used to improve the initial performance of pineapple slips.

  7. Formulation of single super phosphate fertilizer from rock phosphate of Hazara, Pakistan

    Directory of Open Access Journals (Sweden)

    Matiullah Khan

    2012-05-01

    Full Text Available Phosphorus deficiency is wide spread in soils of Pakistan. It is imperative to explore the potential and economics of indigenous Hazara rock phosphate for preparation of single super phosphate fertilizer. For the subject study rock phosphate was collected from Hazara area ground at 160 mesh level with 26% total P2O5 content for manual preparation of single super phosphate fertilizer. The rock phosphate was treated with various concentrations of sulfuric acid (98.9%, diluted or pure in the field. The treatments comprised of 20 and 35% pure acid and diluted with acid-water ratios of 1:5, 1:2, 1:1 and 2:1 v/v for acidulation at the rate of 60 liters 100 kg-1 rock phosphate. The amount was prior calculated in the laboratory for complete wetting of rock phosphate. A quantity of 150 kg rock phosphate was taken as treatment. The respective amount of acid was applied with the spray pump of stainless steel or poured with bucket. After proper processing, chemical analysis of the products showed a range of available P2O5 content from 9.56 to 19.24% depending upon the amount of acid and its dilution. The results reveal at that 1:1 dilutions gave the highest P2O5 content (19.24%, lowest free acid (6 % and 32% weight increase. The application of acid beyond or below this combination either pure or diluted gave hygroscopic product and higher free acids. The cost incurred upon the manual processing was almost half the prevailing rates in the market. These results lead to conclude that application of sulfuric acid at the rate of 60 liters 100 kg-1 with the dilution of 50% (v/v can yield better kind of SSP from Hazara rock phosphate at lower prices.

  8. Evaluation of intestinal phosphate binding to improve the safety profile of oral sodium phosphate bowel cleansing.

    Directory of Open Access Journals (Sweden)

    Stef Robijn

    Full Text Available Prior to colonoscopy, bowel cleansing is performed for which frequently oral sodium phosphate (OSP is used. OSP results in significant hyperphosphatemia and cases of acute kidney injury (AKI referred to as acute phosphate nephropathy (APN; characterized by nephrocalcinosis are reported after OSP use, which led to a US-FDA warning. To improve the safety profile of OSP, it was evaluated whether the side-effects of OSP could be prevented with intestinal phosphate binders. Hereto a Wistar rat model of APN was developed. OSP administration (2 times 1.2 g phosphate by gavage with a 12h time interval induced bowel cleansing (severe diarrhea and significant hyperphosphatemia (21.79 ± 5.07 mg/dl 6h after the second OSP dose versus 8.44 ± 0.97 mg/dl at baseline. Concomitantly, serum PTH levels increased fivefold and FGF-23 levels showed a threefold increase, while serum calcium levels significantly decreased from 11.29 ± 0.53 mg/dl at baseline to 8.68 ± 0.79 mg/dl after OSP. OSP administration induced weaker NaPi-2a staining along the apical proximal tubular membrane. APN was induced: serum creatinine increased (1.5 times baseline and nephrocalcinosis developed (increased renal calcium and phosphate content and calcium phosphate deposits on Von Kossa stained kidney sections. Intestinal phosphate binding (lanthanum carbonate or aluminum hydroxide was not able to attenuate the OSP induced side-effects. In conclusion, a clinically relevant rat model of APN was developed. Animals showed increased serum phosphate levels similar to those reported in humans and developed APN. No evidence was found for an improved safety profile of OSP by using intestinal phosphate binders.

  9. Phosphate application to firing range soils for Pb immobilization: The unclear role of phosphate

    International Nuclear Information System (INIS)

    Chrysochoou, Maria; Dermatas, Dimitris; Grubb, Dennis G.

    2007-01-01

    Phosphate treatment has emerged as a widely accepted approach to immobilize Pb in contaminated soils and waste media, relying on the formation of the highly insoluble mineral pyromorphite as solubility-controlling phase for Pb. As such, phosphate treatment has been proposed as a Best Management Practice (BMP) for firing ranges where Pb occurs in its metallic forms and several other phases (carbonates, oxides). While pyromorphite thermodynamically has the potential to control Pb solubility at low levels, its formation is kinetically controlled by pH, the solubility of the phosphate source, and the solubility of Pb species. Treatability studies have shown that excess quantities of soluble and acidic phosphate sources, such as phosphoric acid, are necessary for successful in situ treatment. Even under these conditions, Extended X-ray Absorption Fine Structure (EXAFS), the only reliable method to identify and quantify Pb speciation, showed that Pb conversion to pyromorphite in in situ treated soils was less than 45% after 32 months. Furthermore, the use of lime (CaO) to restore soil pH in acidified soil treatments inhibited further conversion. Additionally, phosphate treatment is known to reduce bioavailability through pyromorphite formation in the intestinal tract, and the phytoaccumulation of Pb; both desirable effects for Pb-impacted areas. Given the costs of phosphate treatment, the use of biogenic phosphate sources, such as bone meal, may be a more environmentally sustainable approach toward this end. In the many studies focusing on phosphate treatment, the attendant P leaching and eutrophication have been largely overlooked, along with other issues such as the enhanced leaching of oxyanionic contaminants, such as Se, As and W. The success and sustainability of applying phosphate as a BMP in firing range soils therefore remain questionable

  10. Uranium-phosphate relationship in phosphated chalks of the Mons and Picardie Bassins

    Energy Technology Data Exchange (ETDEWEB)

    Quinif, Y; Charlet, J M; Dupuis, C; Robaszynski, F [Faculte Polytechnique de Mons (Belgium)

    1981-11-30

    The lithological and geochemical conditions relative to the ''Senonian'' phosphatic chalks are relatively simple in the Basins of Mons (Belgium) and of Picardy (France). Their characteristics permit us to study chiefly the uranium-phosphate relation. It appears a very good linear correlation between the phosphate and the uranium. The coefficient U/P/sub 2/O/sub 5/ remains a constant from the bottom to the top of the same section, but changes in space for synchronic formations (lateral variation of geochemical facies) and in time for two separated basins.

  11. Molecular identification of phosphate solubilizing bacterium ...

    African Journals Online (AJOL)

    A phosphate solubilizing bacterium was isolated from the rhizosphere soil of upland rice and identified by 16S rRNA gene sequencing. The gene sequence showed 99% homology with Alcaligenes faecalis. Based on the gene sequence homology, it was identified as A. faecalis. Interaction effect of this bacterium on growth ...

  12. Cadmium versus phosphate in the world ocean

    NARCIS (Netherlands)

    Baar, Hein J.W. de; Saager, Paul M.; Nolting, Rob F.; Meer, Jaap van der

    1994-01-01

    Cadmium (Cd) is one of the best studied trace metals in seawater and at individual stations exhibits a more or less linear relation with phosphate. The compilation of all data from all oceans taken from over 30 different published sources into one global dataset yields only a broad scatterplot of Cd

  13. Characterization of Fe -doped silver phosphate glasses

    Indian Academy of Sciences (India)

    ... to their several spe- cial properties such as large thermal expansion coefficients, ... increase the conductivity of these glasses is to increase the modifier or dopant ... phosphate glasses were measured by the a.c. impedance spectroscopic .... and Fe2O3-doped Ag2O–P2O5 glasses were determined from. DSC curves and ...

  14. Metal complex derivatives of hydrogen uranyl phosphate

    International Nuclear Information System (INIS)

    Grohol, D.; Blinn, E.L.

    1994-01-01

    Derivatives of hydrogen uranyl phosphate were prepared by incorporating transition metal complexes into the uranyl phosphate matrix. The transition metal complexes employed include bis(ethylenediamine)copper(II), bis(1,3-propanediamine)copper(II) chloride, (triethylenetetramine)copper(II), (1,4,8,11-tetraazacyclotetradecane)copper(II), (1,4,8,12-tetraazacyclopentadecane)copper(II), (1,4,8,11-tetraazacyclotetradecane)nickel(II) chloride, (triethylenetetramine)nickel(II) and others. The chemical analyses of these derivatives indicated that the incorporation of the transition metal complexes into the uranyl phosphate matrix via ion exchange was not stoichiometric. The extent of ion exchange is dependent on the size and structure of the transition metal complex. All complexes were characterized by X-ray powder diffractometry, electronic and infrared spectra, thermal analyses and chemical analysis. An attempt was made to correlate the degree of quenching of the luminescence of the uranyl ion to the spacing between the uranyl phosphate layers in the derivatives

  15. (VAM) and phosphate solubilizing bacteria (PSB)

    African Journals Online (AJOL)

    User

    2013-09-18

    Sep 18, 2013 ... mycorrhiza (VAM), and phosphate solubilising bacteria (PSB) individually and in .... Two-way analysis of variance (ANOVA) was carried out at a 0.05 level of significance on the data and SPSS version 13.0 was used.

  16. Bismuth phosphates as intermediate temperature proton conductors

    DEFF Research Database (Denmark)

    Huang, Yunjie; Christensen, Erik; Shuai, Qin

    2017-01-01

    by scanning electron microscopy, X-ray diffraction, FT-IR, thermogravimetric analysis and AC impedance. Under dry atmosphere the pure crystalline and amorphous phosphates exhibit an intrinsic conductivity of up to 10-5 S cm-1 at 250 °C. In the presence of atmospheric humidity the conductivity of both types...

  17. Nuclear waste immobilization in iron phosphate glasses

    International Nuclear Information System (INIS)

    Garcia, D.A.; Rodriguez, Diego A.; Menghini, Jorge E.; Bevilacqua, Arturo

    2007-01-01

    Iron-phosphate glasses have become important in the nuclear waste immobilization area because they have some advantages over silicate-based glasses, such as a lower processing temperature and a higher nuclear waste load without losing chemical and mechanical properties. Structure and chemical properties of iron-phosphate glasses are determined in terms of the main components, in this case, phosphate oxide along with the other oxides that are added to improve some of the characteristics of the glasses. For example, Iron oxide improves chemical durability, lead oxide lowers fusion temperature and sodium oxide reduces viscosity at high temperature. In this work a study based on the composition-property relations was made. We used different techniques to characterize a series of iron-lead-phosphate glasses with uranium and aluminium oxide as simulated nuclear waste. We used the Arquimedes method to determine the bulk density, differential temperature analysis (DTA) to determine both glass transition temperature and crystallization temperature, dilatometric analysis to calculate the linear thermal expansion coefficient, chemical durability (MCC-1 test) and X-ray diffraction (XRD). We also applied some theoretic models to calculate activation energies associated with the glass transition temperature and crystallization processes. (author)

  18. 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 ...

  19. Mesoporous titanium phosphates and related molecular sieves ...

    Indian Academy of Sciences (India)

    Unknown

    phosphate using a dilute H2O2 oxidant supports the tetrahedral coordination of Ti in ... production of H2 by photo-reduction of water under UV light irradiation. ... have been extensively studied and used as acid catalysts, adsorbents and ion ... mesoporous silica materials is also of outstanding interest because of their ...

  20. Electrosprayed calcium phosphate coatings for biomedical purposes.

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.

    2006-01-01

    In this thesis, the suitability of the Electrostatic Spray Deposition (ESD) technique was studied for biomedical purposes, i.e., deposition of calcium phosphate (CaP) coatings onto titanium substrates. Using ESD, which is a simple and cheap deposition method for inorganic and organic coatings, it

  1. Serum Calcium, Inorganic Phosphates and some Haematological ...

    African Journals Online (AJOL)

    Objectives: Sickle cell disease has long been associated with bone deformities and pain. Mineral salts such as calcium and inorganic phosphate are critical in bone formation and metabolism. This investigation was designed to study the serum concentration of these minerals as well as some haematological parameters in ...

  2. Isolation and Characterization of Efficient Phosphate Solubilizing ...

    African Journals Online (AJOL)

    Vostro154032bit

    ABSTRACT. Applications of biofertilizer have great practical importance for increasing fertility of the soil and reducing environmental pollution. Screening and characterizing phosphate solubilizing Bacillus. (PSB) strains from different agroecologies of Tigray soil and in vitro assessment for the adaptability under different ...

  3. Isolation and characterization of efficient Phosphate Solubilizing ...

    African Journals Online (AJOL)

    Applications of biofertilizer have great practical importance for increasing fertility of the soil and reducing environmental pollution. Screening and characterizing phosphate solubilizing Bacillus (PSB) strains from different agroecologies of Tigray soil and in vitro assessment for the adaptability under different abiotic stress ...

  4. Thermochemical investigations on uranyl phosphates and arsenates

    International Nuclear Information System (INIS)

    Barten, H.

    1986-01-01

    Results are described of a study of the thermochemical stability of anhydrous phosphates and arsenates. The results of phase studies deal with compound formation and characterization, coexisting phases and limiting physical or chemical properties. The uranyl phosphates evolve oxygen at higher temperatures and the arsenates lose arsenic oxide vapour. These phenomena give the possibility to describe their thermodynamic stabilities. Thus oxygen pressures of uranyl phosphates have been measured using a static, non-isothermal method. Having made available the pure anhydrous compounds in the course of this investigation, molar thermodynamic quantities have been measured as well. These include standard enthalpies of formation from solution calorimetry and high-temperature heat-capacity functions derived from enthalpy increments measured. Some attention is given to compounds with uranium in valencies lower than six which have been met during the investigation. An evaluation is made of the thermodynamics of the compounds studied, to result in tabulized high-temperature thermodynamic functions. Relative stabilities within the systems are discussed and comparisons of the uranyl phosphates and the arsenates are made. (Auth.)

  5. Thermochemical investigations on uranyl phosphates and arsenates

    International Nuclear Information System (INIS)

    Barten, H.

    1986-11-01

    The results are described of a study of the thermochemical stability of anhydrous uranyl phosphates and arsenates. A number of aspects of chemical technological importance are indicated in detail. The synthesized anhydrous uranyl phosphates and arsenates were very hygroscopic, so that experiments on these compounds had to be carried out under moisture-free conditions. Further characterisation of these compounds are given, including a study of their thermal stabilities and phase relations. The uranyl phosphates reduced reversibly at temperatures of the order of 1100 to 1600 0 C. This makes it possible to express their relative stabilities quantitatively, in terms of the oxygen pressures of the reduction reactions. The thermal decomposition of uranyl arsenates did not occur by reduction, as for the phosphates, but by giving off arsenic oxide vapour. The results of measurements of enthalpies of solution led to the determination of the enthalpies of formation, heat capacity and the standard entropies of the uranyl arsenates. The thermochemical functions at high-temperatures could consequently be calculated. Attention is paid to the possible formation of uranium arsenates, whose uranium has a valency lower than six, hitherto not reported in literature. It was not possible to prepare arsenates of tetravalent uranium. However, three new compounds were observed, one of these, UAsO 5 , was studied in some detail. (Auth.)

  6. Spectrophotometric Determination of Nitrate and Phosphate Levels ...

    African Journals Online (AJOL)

    MBI

    2013-04-09

    Apr 9, 2013 ... may help in the growth of algae (Beavington,. 1977). Determination of phosphate ion in drinking water. 50cm3 of water sample was pipetted into a 500cm3 volumetric flask, 5cm3 of Ammonium molybdate solution and 3.0cm3 of ascorbic acid were added with swirling, the mixture was diluted to the mark with ...

  7. PREVENTION OF PHOSPHATE - INDUCED MITOCHONDRIAL SWELLING

    Science.gov (United States)

    Kroll, Arnold J.; Kuwabara, Toichiro

    1962-01-01

    The prevention of phosphate-induced mitochondrial swelling in the whole retina of the rabbit was studied with the electron microscope. It was found that a mixture of ATP, Mg++, and bovine serum albumin protected the mitochondria in vitro. This finding confirmed the results obtained spectrophotometrically with isolated rat liver mitochondria by Lehninger. PMID:13927020

  8. Substoichiometric determination of uranium in phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, N; Hanzawa, K; Imura, H

    1986-01-01

    The substoichiometric isotope dilution analysis for U(VI) in a synergic extraction system of an excess amount of a chelating agent hexafluoroacetylacetone (HHFA) and a substoichiometric amount of U(VI) can be precisely extracted, and U down to ppm levels can be accurately determined by the present method. This method was applied to the analysis of a phosphate rock.

  9. TUCS/phosphate mineralization of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L. [Argonne National Lab., IL (United States)

    1997-10-01

    This program has as its objective the development of a new technology that combines cation exchange and mineralization to reduce the concentration of heavy metals (in particular actinides) in groundwaters. The treatment regimen must be compatible with the groundwater and soil, potentially using groundwater/soil components to aid in the immobilization process. The delivery system (probably a water-soluble chelating agent) should first concentrate the radionuclides then release the precipitating anion, which forms thermodynamically stable mineral phases, either with the target metal ions alone or in combination with matrix cations. This approach should generate thermodynamically stable mineral phases resistant to weathering. The chelating agent should decompose spontaneously with time, release the mineralizing agent, and leave a residue that does not interfere with mineral formation. For the actinides, the ideal compound probably will release phosphate, as actinide phosphate mineral phases are among the least soluble species for these metals. The most promising means of delivering the precipitant would be to use a water-soluble, hydrolytically unstable complexant that functions in the initial stages as a cation exchanger to concentrate the metal ions. As it decomposes, the chelating agent releases phosphate to foster formation of crystalline mineral phases. Because it involves only the application of inexpensive reagents, the method of phosphate mineralization promises to be an economical alternative for in situ immobilization of radionuclides (actinides in particular). The method relies on the inherent (thermodynamic) stability of actinide mineral phases.

  10. Isolation and Characterization of Efficient Phosphate Solubilizing ...

    African Journals Online (AJOL)

    Vostro154032bit

    Research Article http://dx.doi.org/10.4314/mejs.v9i2.9. Momona Ethiopian Journal of Science (MEJS), V9(2):262-273,2017 ©CNCS, Mekelle University, ISSN:2220-184X. Isolation and Characterization of Efficient Phosphate Solubilizing Bacillus (PSB) from Different Agro-ecological Zones of Tigray Soil, Ethiopia. Kibrom, F.G.

  11. Intercalation of cyclic ketones into vanadyl phosphate

    Czech Academy of Sciences Publication Activity Database

    Zima, Vítězslav; Melánová, Klára; Beneš, L.; Trchová, Miroslava; Dybal, Jiří

    2005-01-01

    Roč. 178, č. 1 (2005), s. 314-320 ISSN 0022-4596 R&D Projects: GA AV ČR KSK4050111 Institutional research plan: CEZ:AV0Z40500505 Keywords : vanadyl phosphate Subject RIV: CA - Inorganic Chemistry Impact factor: 1.725, year: 2005

  12. Synthesis and antimicrobial evaluation of new 3-alkyl/aryl-2-[((alpha,alpha-diphenyl-alpha-hydroxy)acetyl)hydrazono]-5-methyl-4-thiazolidinones.

    Science.gov (United States)

    Güzeldemirci, Nuray Ulusoy; Ilhan, Eser; Küçükbasmaci, Omer; Satana, Dilek

    2010-01-01

    New 4-thiazolidinone derivatives of benzilic acid (alpha,alpha-diphenyl-alpha-hydroxyacetic acid) have been synthesized and evaluated for antibacterial and antifungal activities. The reaction of 1- (alpha,alpha-diphenyl-alpha-hydroxy)acetyl-4-alkyl/arylthiosemicarbazides with ethyl 2-bromopropionate gave 3-alkyl/aryl-2-[((alpha,alpha-diphenyl-alpha-hydroxy)acetyl)hydrazono]-5-methyl-4-thiazolidinone derivatives. Their antibacterial and antifungal activities were evaluated against S. aureus ATCC 29213, P. aeruginosa ATCC 27853, E. coli ATCC 25922, C. albicans ATCC 10231, C. parapsilosis ATCC 22019, C. krusei ATCC 6258, T. mentagrophytes var. erinacei NCPF 375, M. gypseum NCPF 580 and T. tonsurans NCPF 245. 3e, 3f, 3g and 3h showed the highest antibacterial activity. Particularly 3a and 3e showed the highest antifungal activities against C. parapsilosis ATCC 22019, T. tonsurans NCPF 245 and M. gypseum NCPF 580.

  13. Contemporary 14C radiocarbon levels of oxygenated polybrominated diphenyl ethers (O-PBDEs) isolated in sponge–cyanobacteria associations

    Science.gov (United States)

    Guitart, Carlos; Slattery, Marc; Ankisetty, Sridevi; Radwan, Mohamed; Ross, Samir J.; Letcher, Robert J.; Reddy, Christopher M.

    2016-01-01

    Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon (14C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable 14C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the 14C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2′-OHBDE68, 2′,6-diOH-BDE159, and a recently identified compound, 2′-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C12H22O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds. PMID:21276990

  14. Contemporary 14C radiocarbon levels of oxygenated polybrominated diphenyl ethers (O-PBDEs) isolated in sponge-cyanobacteria associations

    International Nuclear Information System (INIS)

    Guitart, Carlos; Slattery, Marc; Ankisetty, Sridevi; Radwan, Mohamed; Ross, Samir J.; Letcher, Robert J.; Reddy, Christopher M.

    2011-01-01

    Research highlights: → O-PBDEs in the marine environment could have both natural and anthropogenic origin. → Molecular-level 14 C is measured by accelerated mass spectrometry. → Industrial products, derived from fossil sources, are radiocarbon 14 C-free. → O-PBDEs compounds from marine sponges show modern levels of 14 C. → Some species could produce O-PBDEs rather than being biotransformation from industrial PBDEs. - Abstract: Considerable debate surrounds the sources of oxygenated polybrominated diphenyl ethers (O-PBDEs) in wildlife as to whether they are naturally produced or result from anthropogenic industrial activities. Natural radiocarbon ( 14 C) abundance has proven to be a powerful tool to address this problem as recently biosynthesized compounds contain contemporary (i.e. modern) amounts of atmospheric radiocarbon; whereas industrial chemicals, mostly produced from fossil fuels, contain no detectable 14 C. However, few compounds isolated from organisms have been analyzed for their radiocarbon content. To provide a baseline, we analyzed the 14 C content of four O-PBDEs. These compounds, 6-OH-BDE47, 2'-OH-BDE68, 2',6-diOH-BDE159, and a recently identified compound, 2'-MeO-6-OH-BDE120, were isolated from the tropical marine sponges Dysidea granulosa and Lendenfeldia dendyi. The modern radiocarbon content of their chemical structures (i.e. diphenyl ethers, C 12 H 22 O) indicates that they are naturally produced. This adds to a growing baseline on, at least, the sources of these unusual compounds.

  15. Transformation of hydroxylated and methoxylated 2,2',4,4',5-brominated diphenyl ether (BDE-99) in plants

    Institute of Scientific and Technical Information of China (English)

    Lili Pan; Jianteng Sun; Xiaodan Wu; Zi Wei; Lizhong Zhu

    2016-01-01

    The occurrence and fate of hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) have received significant attention.However,there is limited information on the metabolism relationship between OH-pentaBDEs and MeO-pentaBDEs that were frequently detected with relatively high concentrations in the environment.In this study,the biotransformation between OH-BDE-99 and MeO-BDE-99 was investigated in rice,wheat,and soybean plants.All the three plants can metabolize OH-BDE-99 to corresponding homologous methoxylated metabolites,while the transformation from MeO-BDE-99 to OH-BDE-99 could only be found in soybean.The conversion of parent compounds was the highest in soybean,followed by wheat and rice.Transformation products were found mainly in the roots,with few metabolites being translocated to the shoots and solution after exposure.The results of this study provide valuable information for a better understanding of the accumulation and transformation of OH-PBDEs and MeO-PBDEs in different plants.

  16. Occurrence, bioaccumulation and potential sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of South China

    International Nuclear Information System (INIS)

    Zhang Baozhong; Ni Honggang; Guan Yufeng; Zeng, Eddy Y.

    2010-01-01

    To determine the potential input sources of polybrominated diphenyl ethers (PBDEs) to fish farming environments in South China, samples of seven various environmental matrices were collected from October 2006-September 2007. Tri- to deca-BDEs were detected in all samples analyzed, with mean concentrations (±standard deviations) at 5.7 ± 3.6 ng/L in pond water, 15 ± 11 ng/g dry wt. in pond sediment, 12 ± 3.8 ng/g dry wt. in bank soil, 21 ± 20 ng/g lipid wt. in fish, and 93 ± 62 ng/g lipid wt. in fish feeds. In addition, BDE-209 was the major constituent in all samples except fish and BDE-47 was predominant in fish samples. Relatively high abundances of BDE-49 were detected in all the samples compared to those in the penta-BDE technical products. Several bioaccumulation factors were evaluated. Finally, statistical analyses suggested that fish feed, as well as pond water at a lesser degree, may have been the major source of PBDEs in freshwater farmed fish. - Occurrence and sources of polybrominated diphenyl ethers in typical freshwater cultured fish ponds of the Pearl River Delta, South China are examined.

  17. Waste water treatment plants as sources of polyfluorinated compounds, polybrominated diphenyl ethers and musk fragrances to ambient air

    International Nuclear Information System (INIS)

    Weinberg, Ingo; Dreyer, Annekatrin; Ebinghaus, Ralf

    2011-01-01

    To investigate waste water treatment plants (WWTPs) as sources of polyfluorinated compounds (PFCs), polybrominated diphenyl ethers (PBDEs) and synthetic musk fragrances to the atmosphere, air samples were simultaneously taken at two WWTPs and two reference sites using high volume samplers. Contaminants were accumulated on glass fiber filters and PUF/XAD-2/PUF cartridges, extracted compound-dependent by MTBE/acetone, methanol, or hexane/acetone and detected by GC-MS or HPLC-MS/MS. Total (gas + particle phase) concentrations ranged from 97 to 1004 pg m -3 (neutral PFCs), -3 (ionic PFCs), 5781 to 482,163 pg m -3 (musk fragrances) and -3 (PBDEs) and were usually higher at WWTPs than at corresponding reference sites, revealing that WWTPs can be regarded as sources of musk fragrances, PFCs and probably PBDEs to the atmosphere. Different concentrations at the two WWTPs indicated an influence of WWTP size or waste water origin on emitted contaminant amounts. - Waste water treatment plants can be regarded as sources of musk fragrances, polyfluorinated compounds (PFCs) and polybrominated diphenyl ethers (PBDEs) to the atmosphere

  18. Effects of a diphenyl-ether herbicide, oxyfluorfen, on human BFU-E/CFU-E development and haemoglobin synthesis.

    Science.gov (United States)

    Rio, B; Parent-Massin, D; Lautraite, S; Hoellinger, H

    1997-02-01

    The diphenyl-ether herbicides exert their phytotoxic activity by preventing chlorophyll formation in plants as a result of inhibition of protoporphyrinogen oxidase. This enzyme is the last step of the common pathway for chlorophyll and haem biosynthesis. The aim of this work is to determine whether herbicide inhibitors of plant protoporphyrinogen oxidase could act on the human protoporphyrinogen oxidase involved in haemoglobin synthesis and cause heamatologic diseases. Human erythroblastic progenitors (BFU-E/CFU-E: Burst Forming Unit-Erythroid and Colony Forming Unit-Erythroid) were exposed to oxyfluorfen, a diphenyl-ether herbicide in the presence of erythropoietin, and the haematoxicity evaluated in vitro by scoring the development of BFU-E/CFU-E colonies after 7 and 14 days of culture. The toxic effect on differentiation has been evaluated using four criteria: morphology, total protein, total porphyrin, and haemoglobin content. The study of BFU-E/CFU-E proliferation and differentiation showed a cytotoxic effect of oxyfluorfen only at very high concentrations. In contrast, haemoglobin synthesis can be inhibited by concentration of oxyfluorfen (10(-4) M) that have no adverse effect on cellular proliferation.

  19. Crystal and Molecular Structure of Bis(2,2-diphenyl-N-(di-n-propylcarbamothioyl acetamidocopper(II Complex

    Directory of Open Access Journals (Sweden)

    Hakan Arslan

    2011-01-01

    Full Text Available Bis(2,2-diphenyl-N-(di-n-propylcarbamothioyl acetamidocopper(II complex has been synthesized and characterized by elemental analysis and FT-IR spectroscopy. The crystal and molecular structure of the title compound has been determined from single crystal X-ray diffraction data. It crystallizes in the triclinic space group P-1, with a = 13.046(2 Å, b = 13.135(2 Å, c = 13.179(2 Å, α= 67.083(4°, β= 67.968(4°, γ = 84.756(4° and Dcalc =1.330 g/cm3 for Z = 2. The crystal structure confirms that the complex is a mononuclear copper(II complex and the 2,2-diphenyl-N-(di-n-propyl-carbamothioylacetamide ligand is a bidentate chelating ligand, coordinating to the copper atom through the thiocarbonyl and carbonyl groups. This coordination has a slightly distorted square-planar geometry (O1-Cu1-O2: 86.48(11°, O1-Cu1-S1: 93.85(9°, O2-Cu1-S2: 94.20(9° and S1-Cu1-S2: 91.21(4°. The title molecule shows a cis-arrangement and C–O, C–S and C–N bond lengths of the complex suggest considerable electronic delocalization in the chelate rings.

  20. Calcium phosphate saturation in seawater around the Andaman Island

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.; Reddy, C.V.G.

    Ionic product (IP) of calcium phosphate is calculated at some stations around Andaman Island. The depthwise variations of the ionic product of calcium phosphate seem to follow a normal trend with maximum saturation value between 100 to 200 m. Using...

  1. Genetics Home Reference: glucose-6-phosphate dehydrogenase deficiency

    Science.gov (United States)

    ... deficiency Encyclopedia: Glucose-6-phosphate dehydrogenase test Encyclopedia: Hemolytic anemia Encyclopedia: Newborn jaundice Health Topic: Anemia Health Topic: G6PD Deficiency Health Topic: Newborn Screening Genetic and Rare Diseases Information Center (1 link) Glucose-6-phosphate dehydrogenase ...

  2. Preparation of Edible Corn Starch Phosphate with Highly Reactive ...

    African Journals Online (AJOL)

    1Food & Bioengineering Department, Henan University of Science and Technology, Luoyang, Henan 471003 ... Purpose: To prepare edible corn starch phosphate under optimized experimental conditions. ... In food industry, starch phosphate.

  3. Calcium phosphate saturation in the western Bay of Bengal

    Digital Repository Service at National Institute of Oceanography (India)

    Naik, S.; Reddy, C.V.G.

    Temperature, inorganic phosphate concentration and pH seem to be the major factors influencing the degree of saturation of calcium phosphate in sea water. Two water regions can be demarcated in the study area based on the saturation patterns...

  4. Analyses of uranium in some phosphate commercial products

    International Nuclear Information System (INIS)

    Kamel, N.H.M.; Sohsah, M.; Mohammad, H.M.; Sadek, M.

    2005-01-01

    The raw materials used in manufacturing of phosphate fertilizer products were derived from rocks. Rocks contain a remarkable of natural radioactivity. Uranium and phosphorous were originally initiated at the same time of the initiated rocks. The purpose of this research is to investigate solubility of uranium phosphate species at the phosphate fertilizer samples, samples including; raw phosphate material, single super phosphates (SSP) granules and powdered, triple super phosphates (TSP) and phosphogypsum samples were obtained from Abu-Zabal factory in Egypt. Solubility of uranium phosphate species was estimated. It was found that, less than half of the uranium phosphate species are soluble in water. The soluble uranium may be enter into the food chains by plant. Therefore, restriction should be done in order to limit contamination of land and the public

  5. Recovery of uranium and the lanthanides from phosphate rock

    Energy Technology Data Exchange (ETDEWEB)

    Habashi, F; Awadalla, F T; Zailaf, M

    1986-06-01

    A process is proposed for the treatment of phosphate rock for the recovery of uranium and lanthanides. The process assures the production of phosphatic fertilisers without polluting the environment with radioactive material.

  6. Cloning and expression of pineapple sucrose- phosphate synthase ...

    African Journals Online (AJOL)

    hope&shola

    2010-12-06

    Dec 6, 2010 ... phosphate; EDTA, ethylene diamine tetraacetic acid; Ivr, invertase; SS .... phenolics, tannins and artifacts due to differences of tissue composition ..... Banana sucrose-phosphate synthase gene expression during fruit ripening.

  7. Iron phosphate glass containing simulated fast reactor waste: Characterization and comparison with pristine iron phosphate glass

    International Nuclear Information System (INIS)

    Joseph, Kitheri; Asuvathraman, R.; Venkata Krishnan, R.; Ravindran, T.R.; Govindaraj, R.; Govindan Kutty, K.V.; Vasudeva Rao, P.R.

    2014-01-01

    Detailed characterization was carried out on an iron phosphate glass waste form containing 20 wt.% of a simulated nuclear waste. High temperature viscosity measurement was carried out by the rotating spindle method. The Fe 3+ /Fe ratio and structure of this waste loaded iron phosphate glass was investigated using Mössbauer and Raman spectroscopy respectively. Specific heat measurement was carried out in the temperature range of 300–700 K using differential scanning calorimeter. Isoconversional kinetic analysis was employed to understand the crystallization behavior of the waste loaded iron phosphate glass. The glass forming ability and glass stability of the waste loaded glass were also evaluated. All the measured properties of the waste loaded glass were compared with the characteristics of pristine iron phosphate glass

  8. Transfer of Some Major and Trace Elements From Phosphate Rock to Super-Phosphate Fertilizers

    International Nuclear Information System (INIS)

    El-Reefya, H.I.; Bin-Jaz, A.A.; Zaied, M.E.; Badran, H.M.; Badran, H.M.

    2014-01-01

    This study assesses the transfer of some major and trace elements from phosphate rock (PR) to single (SSP) and triple (TSP) superphosphate fertilizers. Samples from a fertilizer plant and local market were collected and analyzed using inductively coupled plasma spectrometer. Cluster analysis indicated that the inner-relationship among the concentration of the elements in PR, SSP, and TSP are different. Only one element (Mo) has concentration in SSP higher than phosphate rock. The production process of these two types of superphosphate leads to transfer higher portion of Mn, B, Cu, Mo, Sr, and V present in the phosphate rock to SSP than TSP. The potentially hazardous element Cd is also transmitted more to SSP than TSP, and Cr is equally transferred to both types. The mean elemental concentrations normalized to the percentage of P 2 O 5 demonstrate that for most elements they are the higher concentrations in SSP are linked to the phosphate contents

  9. Radioactivity of phosphate ores from Karatas-Mazidag phosphate deposit of Turkey

    International Nuclear Information System (INIS)

    Akyuez, T.; Varinlioglu, A.; Kose, A.; Akyuez, S.

    2000-01-01

    The specific activities of 238 U, 226 Ra, 232 Th and 40 K in the composite samples of phosphate ores of type I (grey-coloured ore, with high P 2 O 5 (21-35%) and low calcite content) and of type II (grey coloured calcite ore, with low P 2 O 5 content (5-17%)) of Karatas-Mazidag phosphate deposit, Turkey, have been determined by gamma spectrometry together with phosphatic animal feed ingredients. The concentrations of 238 U, 226 Ra, 232 Th and 40 K were found to be up to 557, 625, 26 and 297 Bq x kg -1 , respectively. Radium equivalent activities of samples were calculated and compared with those given in the literature. Uranium concentration of the individual phosphate samples, from which composite samples of ores of type I and II have been prepared, were found to show and increasing trend with increasing P 2 O 5 and F concentrations. (author)

  10. Sorption of cesium on titanium and zirconium phosphates

    International Nuclear Information System (INIS)

    Lebedev, V.N.; Mel'nik, N.A.; Rudenko, A.V.

    2003-01-01

    Titanium and zirconium phosphates were prepared from mineral raw materials of the Kola Peninsula. Their capability to recover cesium cations from the model solutions and liquid radioactive waste (LRW) was studied. Titanium phosphate prepared from solutions formed by titanite breakdown demonstrates greater distribution coefficients of cesium as compared to zirconium phosphate. Titanium phosphate as a cheaper agent featuring greater sorption capacity was recommended for treatment of LRW to remove cesium [ru

  11. Bacterial formation of phosphatic laminites off Peru.

    Science.gov (United States)

    Arning, E T; Birgel, D; Brunner, B; Peckmann, J

    2009-06-01

    Authigenic phosphatic laminites enclosed in phosphorite crusts from the shelf off Peru (10 degrees 01' S and 10 degrees 24' S) consist of carbonate fluorapatite layers, which contain abundant sulfide minerals including pyrite (FeS(2)) and sphalerite (ZnS). Low delta(34)S(pyrite) values (average -28.8 per thousand) agree with bacterial sulfate reduction and subsequent pyrite formation. Stable sulfur isotopic compositions of sulfate bound in carbonate fluorapatite are lower than that of sulfate from ambient sea water, suggesting bacterial reoxidation of sulfide by sulfide-oxidizing bacteria. The release of phosphorus and subsequent formation of the autochthonous phosphatic laminites are apparently caused by the activity of sulfate-reducing bacteria and associated sulfide-oxidizing bacteria. Following an extraction-phosphorite dissolution-extraction procedure, molecular fossils of sulfate-reducing bacteria (mono-O-alkyl glycerol ethers, di-O-alkyl glycerol ethers, as well as the short-chain branched fatty acids i/ai-C(15:0), i/ai-C(17:0) and 10MeC(16:0)) are found to be among the most abundant compounds. The fact that these molecular fossils of sulfate-reducing bacteria are distinctly more abundant after dissolution of the phosphatic laminite reveals that the lipids are tightly bound to the mineral lattice of carbonate fluorapatite. Moreover, compared with the autochthonous laminite, molecular fossils of sulfate-reducing bacteria are: (1) significantly less abundant and (2) not as tightly bound to the mineral lattice in the other, allochthonous facies of the Peruvian crusts consisting of phosphatic coated grains. These observations confirm the importance of sulfate-reducing bacteria in the formation of the phosphatic laminite. Model calculations highlight that organic matter degradation by sulfate-reducing bacteria has the potential to liberate sufficient phosphorus for phosphogenesis.

  12. Comparative study on in vitro biocompatibility of synthetic octacalcium phosphate and calcium phosphate ceramics used clinically.

    Science.gov (United States)

    Morimoto, Shinji; Anada, Takahisa; Honda, Yoshitomo; Suzuki, Osamu

    2012-08-01

    The present study was designed to investigate the extent to which calcium phosphate bone substitute materials, including osteoconductive octacalcium phosphate (OCP), display cytotoxic and inflammatory responses based on their dissolution in vitro. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) ceramics, which are clinically used, as well as dicalcium phosphate dihydrate (DCPD) and synthesized OCP were compared. The materials were well characterized by chemical analysis, x-ray diffraction and Fourier transform infrared spectroscopy. Calcium and phosphate ion concentrations and the pH of culture media after immersion of the materials were determined. The colony forming rate of Chinese hamster lung fibroblasts was estimated with extraction of the materials. Proliferation of bone marrow stromal ST-2 cells and inflammatory cytokine TNF-α production by THP-1 cells grown on the material-coated plates were examined. The materials had characteristics that corresponded to those reported. DCPD was shown to dissolve the most in the culture media, with a marked increase in phosphate ion concentration and a reduction in pH. ST-2 cells proliferated well on the materials, with the exception of DCPD, which markedly inhibited cellular growth. The colony forming capacity was the lowest on DCPD, while that of the other calcium phosphates was not altered. In contrast, TNF-α was not detected even in cells grown on DCPD, suggesting that calcium phosphate materials are essentially non-inflammatory, while the solubility of the materials can affect osteoblastic and fibroblastic cellular attachment. These results indicate that OCP is biocompatible, which is similar to the materials used clinically, such as HA. Therefore, OCP could be clinically used as a biocompatible bone substitute material.

  13. Phosphate and phosphate fertilizer sector: structure and future prospects. [Uranium recovery

    Energy Technology Data Exchange (ETDEWEB)

    Zenaidi, B

    1981-12-01

    A statement of the past evolution of this sector's structure is given. Various prospective studies which have been made are reviewed and lead to the precision of the phosphate requirement in the year 2000 which is between 200 and 250 Mt. Only a small section p. 696-697 is devoted to recovery of uranium contained in phosphate and prospects in this field are given.

  14. The environmental fate of polybrominated diphenyl ethers in the Great Lakes Basin

    Science.gov (United States)

    Gouin, Todd William

    Semi-volatile organic compounds, such as the polybrominated diphenyl ethers (PBDEs) have the potential to undergo long-range atmospheric transport (LRAT) to remote locations, which can increase the exposure of sensitive ecosystems to potentially harmful substances. Regulatory instruments, such as the Stockholm Convention on persistent organic pollutants (POPs), have been implemented to limit and/or prevent this exposure. Through the acquisition of scientific data, knowledge can be gained about the environmental fate and human exposure of chemical substances, and the risks associated with using those substances assessed. PBDEs are a class of flame retardants that are used in a wide range of commercial products. In response to growing concern over the detection of PBDEs in remote regions, a number of regulatory bodies have implemented measures to restrict the use of PBDEs. Using a suite of environmental fate models it is shown that PBDEs will most likely partition to organic carbon in soil and sediment, and that their persistence in the environment will be strongly influenced by their reactivity in those compartments. The transport potential of the PBDEs is investigated using the transport and persistence level III model TaPL3, using model environments with and without vegetation. It is suggested that the LRAT potential of the PBDEs is likely to be greater for the more volatile lower brominated congeners than for the higher brominated congeners, and that the LRAT may be sensitive to seasonal changes in the environment, such as temperature, vegetation and changes in precipitation. Furthermore, model results suggest that the PBDEs may be subject to a "spring pulse" effect, whereby concentrations are elevated in air during the early spring. Field studies support the theory of a "spring pulse" effect, where concentrations were observed to be five times greater during the period between snowmelt and bud burst than the average concentration before and after, but conclude

  15. Polybrominated diphenyl ethers, polychlorinated dibenzo-dioxins, -furans, and -biphenyls in three species of Antarctic penguins.

    Science.gov (United States)

    Corsolini, Simonetta; Borghesi, Nicoletta; Schiamone, Alessandra; Focardi, Silvano

    2007-09-01

    Fish-eating seabirds are recognized to be at risk of accumulating toxic contaminants due to their high position in the trophic web and to their low ability to metabolize xenobiotic compounds. Penguins are widely distributed in Antarctica and represent an important fraction of the Antarctic biomass. They feed mainly on krill and, depending on krill availability, also on fish. It has been reported that predators may be a sink for volatile and toxic chemicals and this may pose a serious environmental problem. Polybrominated diphenyl ethers (PBDEs), polychlorinated dibenzo-dioxins (PCDDs), -furans (PCDFs), and -biphenyls (PCBs), including non-ortho congeners, hexachlorobenzene (HCB) and p,p'-DDE, were quantified in three species of Antarctic Pygoscelids in order to evaluate their accumulation patterns. The potential toxicity of twenty-two dioxin-like congeners was assessed and expressed as 2,3,7,8-tetraCDD equivalents (TEQs). Differences between males and females were investigated. Blood samples of the Adélie penguin Pygoscelis adeliae, Chinstrap penguin Pygoscelis antarctica and Gentoo penguin Pygoscelis papua were collected at Admiralty Bay, King George Is (62 degrees 10'39" S, 58 degrees 26'46" W) in February 2004. Halogenated hydrocarbons were identified and quantified using gas chromatography coupled with gas chromatography mass spectrometry analyses. Results are expressed on a wet weight basis. HCB, p,p'-DDE and sigmaPCBs were higher in Adélie penguins (6.7 +/- 6.1, 8.2 +/- 3.3 and 9.8 +/- 3.8 ng/g, respectively) than in Chinstrap and Gentoo penguins, both of which showed values in the same order of magnitude, but approximately 40% lower than Adélie penguins. Hexa-CBs ranged 35-45% of the residue. Low-chlorinated PCBs (nos. 70+76+95+ 56+60+101) accounted for 40-60% in the three species. PCB101 made up 15% of the residue in Adélie penguins. PBDEs were 291 +/- 477, 107 +/- 104 and 116 +/- 108 pg/g in Adélie, Chinstrap and Gentoo penguins, respectively; the

  16. Discussion of "Polybrominated diphenyl ethers in aircraft cabins--a source of human exposure?" by Anna Christiansson et al. [Chemosphere 73(10) (2008) 1654-1660].

    Science.gov (United States)

    Schecter, Arnold; Colacino, Justin; Haffner, Darrah; Patel, Keyur; Opel, Matthias; Päpke, Olaf

    2010-01-01

    This paper presents new data on the levels of polybrominated diphenyl ethers (PBDEs) in American airline workers. This pilot study did not find elevated total PBDEs in the blood of nine flight attendants and one aircraft pilot who have worked in airplanes for at least the past 5 years. These findings are not consistent with the findings of elevated blood levels of PBDEs from the 2008 Christiansson et al. publication "Polybrominated diphenyl ethers in aircraft cabins - A source of human exposure?" We agree that more research needs to be done on larger, more representative samples of airline workers to better characterize exposure of airline workers and other frequent flyers to PBDEs.

  17. Using Fluorescence XANES Measurement to Correct the Content of Hexavalent Chromium in Chromate Conversion Coatings Determined by Diphenyl Carbazide Color Test

    International Nuclear Information System (INIS)

    Nishino, Junichi; Ofuchi, Hironori; Taniguchi, Yosuke; Honma, Tetsuo; Sekikawa, Toshikazu; Otani, Haruka; Bando, Akio

    2007-01-01

    The Restriction of the use of certain Hazardous Substances (RoHS) directive will take effect on July 1 of this year. From that date, the use of chromate conversion coatings containing hexavalent chromium will not be permitted. By comparing the concentration of Cr6+ determined by the diphenyl carbazide color test and by fluorescence XANES (X-Ray Absorption Near Edge Structure) measurement, we can correct for the Cr6+ content of the color test. This will enable the use of the diphenyl carbazide color test to check product shipments in compliance with the RoHS directive

  18. Physico-chemical characterization of Ogun and Sokoto phosphate ...

    African Journals Online (AJOL)

    Gypsum, calcite and lime were associated with both rock phosphates indicating their liming potential in the soil. ORP was more soluble in water, probably because it ... fertilizers and direct application in crop production. Keywords: Phosphorus, apatite, crop production, fertilizer, Ogun rock phosphate, Sokoto rock phosphate ...

  19. The phosphate balance : current developments and future outlook

    NARCIS (Netherlands)

    Enk, van R.J.; Vee, van der G.; Acera, L.K.; Schuiling, R.; Ehlert, P.A.I.

    2011-01-01

    Phosphate is essential for agricultural production and therefore plays a key role in the global production of food and biofuels. There are no agricultural alternatives for phosphate, and a substantial fraction of our annual phosphate consumption is dispersed into the environment where it is largely

  20. The phosphate balance : Current developments and future outlook

    NARCIS (Netherlands)

    Enk, R.J. van; Acera, L.K.; Schuiling, R.D.; Ehlert, P.; de Wilt, J.G.; van Haren, R.J.F.

    2011-01-01

    Phosphate is essential for agricultural production and therefore plays a key role in the global production of food and biofuels. There are no agricultural alternatives for phosphate, and a substantial fraction of our annual phosphate consumption is dispersed into the environment where it is largely

  1. 21 CFR 582.5697 - Riboflavin-5-phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Riboflavin-5-phosphate. 582.5697 Section 582.5697 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5697 Riboflavin-5-phosphate. (a) Product. Riboflavin-5-phosphate. (b) Conditions of use...

  2. 21 CFR 582.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium aluminum phosphate. 582.1781 Section 582.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Additives § 582.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b) Conditions of...

  3. 21 CFR 182.1781 - Sodium aluminum phosphate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium aluminum phosphate. 182.1781 Section 182.1781 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... Food Substances § 182.1781 Sodium aluminum phosphate. (a) Product. Sodium aluminum phosphate. (b...

  4. Radiological impact of natural radioactivity in Egyptian phosphate rocks, phosphogypsum and phosphate fertilizers

    International Nuclear Information System (INIS)

    El-Bahi, S.M.; Sroor, A.; Mohamed, Gehan Y.; El-Gendy, N.S.

    2017-01-01

    In this study, the activity concentrations of the natural radionuclides in phosphate rocks and its products were measured using a high- purity germanium detector (HPGe). The obtained activity results show remarkable wide variation in the radioactive contents for the different phosphate samples. The average activity concentration of "2"3"5U, "2"3"8U, "2"2"6Ra, "2"3"2Th and "4"0K was found as (45, 1031, 786, 85 and 765 Bq/kg) for phosphate rocks, (28, 1234, 457, 123 and 819 Bq/kg) for phosphate fertilizers, (47, 663, 550, 79 and 870 Bq/kg) for phosphogypsum and (25, 543, 409, 54 and 897 Bq/kg) for single super phosphate respectively. Based on the measured activities, the radiological parameters (activity concentration index, absorbed gamma dose rate in outdoor and indoor and the corresponding annual effective dose rates and total excess lifetime cancer risk) were estimated to assess the radiological hazards. The total excess lifetime cancer risk (ELCR) has been calculated and found to be high in all samples, which related to high radioactivity, representing radiological risk for the health of the population. - Highlights: • Level of radioactivity of phosphate rocks and by-products samples. • The radiological health hazard parameters. • Radiological risk to the health of the population. • The excess lifetime cancer risk factor.

  5. Phosphate uptake kinetics for four species of submerged freshwater macrophytes measured by a 33P phosphate radioisotope technique

    DEFF Research Database (Denmark)

    Christiansen, Nina Høj; Andersen, Frede Østergaard; Jensen, Henning S.

    2016-01-01

    Phosphate (Pi) uptake kinetics were determined in shoot and root tissues for four freshwater macrophyte species, Littorella uniflora, Potamogeton perfoliatus, Myriophyllum alterniflorum and Elodea canadensis, using a radioactive 33P phosphate technique. Collection of plant material in the oligotr...

  6. Infrared-spectroscopy analysis of zinc phosphate and nickel and manganese modified zinc phosphate coatings on electrogalvanized steel

    International Nuclear Information System (INIS)

    Fernandes, Kirlene Salgado; Alvarenga, Evandro de Azevedo; Lins, Vanessa de Freitas Cunha

    2011-01-01

    Hopeite-type phosphate coatings in which zinc is partially replaced by other metals like manganese and nickel are of great interest for the automotive and home appliance industries. Such industries use phosphate conversion coatings on galvanized steels in association with cataphoretic electro painting. Zinc phosphates modified with manganese and nickel are isomorphic with the hopeite, and the phase identification using X-ray diffraction is difficult. In this paper, the phosphate coatings are identified using the Fourier transform infrared spectroscopy (FTIR). (author)

  7. Phosphate additives in food--a health risk.

    Science.gov (United States)

    Ritz, Eberhard; Hahn, Kai; Ketteler, Markus; Kuhlmann, Martin K; Mann, Johannes

    2012-01-01

    Hyperphosphatemia has been identified in the past decade as a strong predictor of mortality in advanced chronic kidney disease (CKD). For example, a study of patients in stage CKD 5 (with an annual mortality of about 20%) revealed that 12% of all deaths in this group were attributable to an elevated serum phosphate concentration. Recently, a high-normal serum phosphate concentration has also been found to be an independent predictor of cardiovascular events and mortality in the general population. Therefore, phosphate additives in food are a matter of concern, and their potential impact on health may well have been underappreciated. We reviewed pertinent literature retrieved by a selective search of the PubMed and EU databases (www.zusatzstoffe-online.de, www.codexalimentarius.de), with the search terms "phosphate additives" and "hyperphosphatemia." There is no need to lower the content of natural phosphate, i.e. organic esters, in food, because this type of phosphate is incompletely absorbed; restricting its intake might even lead to protein malnutrition. On the other hand, inorganic phosphate in food additives is effectively absorbed and can measurably elevate the serum phosphate concentration in patients with advanced CKD. Foods with added phosphate tend to be eaten by persons at the lower end of the socioeconomic scale, who consume more processed and "fast" food. The main pathophysiological effect of phosphate is vascular damage, e.g. endothelial dysfunction and vascular calcification. Aside from the quality of phosphate in the diet (which also requires attention), the quantity of phosphate consumed by patients with advanced renal failure should not exceed 1000 mg per day, according to the guidelines. Prospective controlled trials are currently unavailable. In view of the high prevalence of CKD and the potential harm caused by phosphate additives to food, the public should be informed that added phosphate is damaging to health. Furthermore, calls for labeling

  8. Impaired Phosphate Tolerance Revealed With an Acute Oral Challenge.

    Science.gov (United States)

    Turner, Mandy E; White, Christine A; Hopman, Wilma M; Ward, Emilie C; Jeronimo, Paul S; Adams, Michael A; Holden, Rachel M

    2018-01-01

    Elevated serum phosphate is consistently linked with cardiovascular disease (CVD) events and mortality in the setting of normal and impaired kidney function. However, serum phosphate does not often exceed the upper limit of normal until glomerular filtration rate (GFR) falls below 30 mL/min/m 2 . It was hypothesized that the response to an oral, bioavailable phosphate load will unmask impaired phosphate tolerance, a maladaptation not revealed by baseline serum phosphate concentrations. In this study, rats with varying kidney function as well as normo-phosphatemic human subjects, with inulin-measured GFR (13.2 to 128.3mL/min), received an oral phosphate load. Hormonal and urinary responses were evaluated over 2 hours. Results revealed that the more rapid elevation of serum phosphate was associated with subjects and rats with higher levels of kidney function, greater responsiveness to acute changes in parathyroid hormone (PTH), and significantly more urinary phosphate at 2 hours. In humans, increases in urinary phosphate to creatinine ratio did not correlate with baseline serum phosphate concentrations but did correlate strongly to early increase of serum phosphate. The blunted rise in serum phosphate in rats with CKD was not the result of altered absorption. This result suggests acute tissue deposition may be altered in the setting of kidney function impairment. Early recognition of impaired phosphate tolerance could translate to important interventions, such as dietary phosphate restriction or phosphate binders, being initiated at much higher levels of kidney function than is current practice. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  9. Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice

    Directory of Open Access Journals (Sweden)

    Qurban Ali Panhwar

    2013-01-01

    Full Text Available A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB and organic acids (oxalic & malic on phosphate (P solubilization from phosphate rock (PR and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM, and PSB strain (Bacillus sp. were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg−1, plant P uptake (0.78 P pot−1, and plant biomass (33.26 mg. Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g−1 compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH.

  10. Prevention of radioactive contamination in the manufacture of phosphate fertilizers

    International Nuclear Information System (INIS)

    Romero G, E.T.

    1995-01-01

    In this work was studied the separation of uranium from the phosphate rock to decrease the level of radioactivity in the phosphate fertilizers, this prevents the redistribution of uranium in the environment. The uranium leaching conditions from phosphate rock were estimated using alkaline solutions. The changes in the natural phosphate rock after leaching were studied. The amenability to separate the uranium from phosphate rock with ammonium carbonate / bicarbonate solution was determined. The uranium extraction was approximately 40%. The leaching conditions showed high selectivity for uranium without changes in the ore structure. The bulk ore was not dissolved. (Author)

  11. Radical-induced dephosphorylation of fructose phosphates in aqueous solution

    International Nuclear Information System (INIS)

    Zegota, H.; Sonntag, C. von

    1981-01-01

    Oxygen free N 2 O-saturated aqueous solutions of D-fructose-1-phosphate and D-fructose-6-phosphate were γ-irradiated. Inorganic phosphate and phosphate free sugars (containing four to six carbon atoms) were identified and their G-values measured. D-Fructose-1-phosphate yields (G-values in parentheses) inorganic phosphate (1.6), hexos-2-ulose (0.12), 6-deoxy-2,5-hexodiulose (0.16), tetrulose (0.05) and 3-deoxytetrulose (0.15). D-Fructose-6-phosphate yields inorganic phosphate (1.7), hexos-5-ulose (0.1), 6-deoxy-2,5-hexodiulose (0.36), 3-deoxy-2,5-hexodiulose and 2-deoxyhexos-5-ulose (together 0.18). On treatment with alkaline phosphatase further deoxy sugars were recognized and in fructose-1-phosphate G(6-deoxy-2,5-hexodiulose) was increased to a G-value of 0.4. Dephosphorylation is considered to occur mainly after OH attack at C-5 and C-1 in fructose-1-phosphate and at C-5 and C-6 in fructose-6-phosphate. Reaction mechanisms are discussed. (orig.)

  12. Radiophotoluminescence from silver-doped phosphate glass

    International Nuclear Information System (INIS)

    Miyamoto, Y.; Takei, Y.; Nanto, H.; Kurobori, T.; Konnai, A.; Yanagida, T.; Yoshikawa, A.; Shimotsuma, Y.; Sakakura, M.

    2011-01-01

    Glass dosimeter utilizing radiophotoluminescence (RPL) is one of accumulation type solid state dosimeters, which is based on luminescence phenomenon of silver (Ag + ions)-doped phosphate glass exposed to ionizing radiation. In this study, to clarify the emission mechanism of yellow and blue RPL peaks, optical properties of Ag + -doped glass, such as optical absorption spectrum, RPL excitation spectrum before and after X-ray irradiation as well as the lifetime of both RPL peaks are measured. From the results, we discuss the emission mechanism of yellow (peaked at 2.21 eV) and blue (peaked at 2.70 eV) RPL using a proposed energy band diagram for RPL emission and excitation in Ag + -doped phosphate glass. It is found that the radiative lifetime of blue RPL is three orders of magnitude faster than that of yellow RPL.

  13. Sphingosine-1-phosphate and renal vasoconstriction

    DEFF Research Database (Denmark)

    Jensen, Boye L

    2018-01-01

    ) and in conjunction with increased S1P release in pathophysiological situations like sepsis and ischemia-reperfusion incidents, this effect could be relevant in acute kidney injury with parallel decreases in renal blood flow and GFR. This article is protected by copyright. All rights reserved.......In the present issue of Acta Physiologica, Guan et al. in their article "Mechanisms of sphingosine-1-phosphate-mediated vasoconstriction of rat afferent arterioles" (1) address the signaling events associated with sphingosine-1-phosphate (S1P)-mediated renal afferent vasoconstriction and show in......, technically demanding, blood-perfused juxtamedullary nephron preparation that S1P signaling relies predominantly on transmembrane calcium influx from the extracellular fluid through L-type calcium channels with contribution from oxidative stress metabolites(1) . So not only is new information on S1P signaling...

  14. Radon Progeny in Egyptian Underground Phosphate Mines

    International Nuclear Information System (INIS)

    El-Hady, M.A.; Mohammed, A.; El-Hussein, A.; Ali, A.E.; Ahmed, A.A.

    2001-01-01

    In addition to the workers in uranium mines, the staff of other underground mines, such as workers in underground phosphate mines, can be exposed to 222 Rn and its progeny. In this study the individual radon progeny concentrations were measured in three Egyptian underground phosphate mines to estimate the occupational exposure of the workers at those sites. A filter method was used to measure individual radon progeny concentrations ( 218 Po, 214 Pb and 214 Po). The reported mean values of radon progeny concentrations exceed the action levels which are recommended by ICRP 65 (1993). Based on the measured individual radon progeny concentrations ( 218 Po, 214 Pb and 214 Po) in these mines, the annual effective dose for the workers has been calculated using the lung dose model of ICRP 66 (1994). According to the obtained results, some countermeasures were recommended in this study to minimise these exposure levels. (author)

  15. Environmental prospects of uranium from mineral phosphates

    International Nuclear Information System (INIS)

    Schnug, Ewald; Haneklaus, Nils

    2012-01-01

    Uranium (U) is a natural resource that is found in rock phosphates (P). Each year farmers apply unwittingly 167 t/yr U to their soils by P fertilisation. If extracted and used for electricity generation with state of the art nuclear power plants this amount of U could cover the energy demand of 2.4 x 10 6 average German households. Otherwise this finite resource is wasted. U from P fertilisers is an uncommon contribution of agriculture to climate protection. Using the key to calculate the CO 2 depending German car tax band, 1 kilogram P would be valued with 1.8 Euro. More than that the extraction of U from rock phosphates is an efficient measure to avoid U entering the food chain. In particular translocation processes in soils of fertiliser-applied U by run-off and leaching which result in the contamination of surface waters and finally drinking water can be impeded efficiently. (orig.)

  16. Infrared spectroscopy of different phosphates structures.

    Science.gov (United States)

    Jastrzębski, W; Sitarz, M; Rokita, M; Bułat, K

    2011-08-15

    Infrared (IR) spectroscopic studies of mineral and synthetic phosphates have been presented. The interpretation of the spectra has been preceded by the isolated [PO(4)](3-) tetrahedron spectra analyse. The K(3)PO(4) saturated aqueous solution was measured in the special cell for liquids. The obtained IR results have been compared with the theoretical number of IR-active modes. The number and positions of the bands due to P-O vibrations have been established. The phase composition of the phosphates has been determined using XRD and IR spectroscopy methods. The influence of non-tetrahedral cations on the shape of the spectra and the positions of bands has been analysed and the crystalline field splitting effect has been discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. TTPIXE analysis of phosphate rocks and phosphogypsum

    International Nuclear Information System (INIS)

    Martin, J.E.; Respaldiza, M.A.; Ontalba, M.A.; Garcia-Tenorio, R.; Bolivar, J.P.; Silva, M.F. da

    1999-01-01

    The TTPIXE technique was used for the determination of the concentrations of major, minor and trace elements in phosphate rock and phosphogypsum samples. All the samples came from a fertilizer industry site in Huelva (SW of Spain). The analyses were done using proton beams from the 3 MV Van de Graaff accelerator of the 'Instituto Tecnologico e Nuclear' (ITN), Sacavem (Portugal). The aim was to obtain data about the distribution of the different elements in the process of P 2 O 5 production in the factory. The information obtained allowed evaluation of the effectiveness of the chemical treatment employed, and gave a detailed information about the elemental composition of phosphogypsum, the main by-product of phosphate fertilizer production. These data can be useful to define the phosphogypsum management and to evaluate its environmental impact

  18. Aluminum phosphate ceramics for waste storage

    Science.gov (United States)

    Wagh, Arun; Maloney, Martin D

    2014-06-03

    The present disclosure describes solid waste forms and methods of processing waste. In one particular implementation, the invention provides a method of processing waste that may be particularly suitable for processing hazardous waste. In this method, a waste component is combined with an aluminum oxide and an acidic phosphate component in a slurry. A molar ratio of aluminum to phosphorus in the slurry is greater than one. Water in the slurry may be evaporated while mixing the slurry at a temperature of about 140-200.degree. C. The mixed slurry may be allowed to cure into a solid waste form. This solid waste form includes an anhydrous aluminum phosphate with at least a residual portion of the waste component bound therein.

  19. Phosphate sorption characteristics of European alpine soils

    Czech Academy of Sciences Publication Activity Database

    Kaňa, Jiří; Kopáček, Jiří; Camarero, L.; Garcia-Pausas, J.

    2011-01-01

    Roč. 75, č. 3 (2011), s. 862-870 ISSN 0361-5995 R&D Projects: GA ČR(CZ) GA526/09/0567; GA AV ČR(CZ) KJB600960907 Grant - others:EU EMERGE(CZ) EVK1-CT-1999-00032 Institutional research plan: CEZ:AV0Z60170517 Keywords : phosphate sorption * alpine soil s * acidification Subject RIV: DJ - Water Pollution ; Quality Impact factor: 1.979, year: 2011

  20. Phosphate solubilizing bacteria around Indian peninsula

    Digital Repository Service at National Institute of Oceanography (India)

    DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    nitrophenylphosphate by the culture. One mole of nitrophenol is equivalent to 1 atom of phosphorus. The absorbance was read at 418 nm using DU-6 Beckmann spectrophotometer. The activity was expressed as ?mol.Pml-1d-1. The cultures which showed good phosphate... suitable controls. Growth was measured at 600 nm using DU-6 Beckmann spectrophotometer and phosphatase activity was measured as described earlier. For testing the rate of survival of PSB on various carriers 2 g of finely powdered sediment, rice...

  1. Phosphate Barriers for Immobilization of Uranium Plumes

    International Nuclear Information System (INIS)

    Burns, Peter C.

    2005-01-01

    Uranium contamination of the subsurface has remained a persistent problem plaguing remedial design at sites across the U.S. that were involved with production, handling, storage, milling, and reprocessing of fissile uranium for both civilian and defense related purposes. Remediation efforts to date have relied upon excavation, pump-and-treat, or passive remediation barriers (PRB's) to remove or attenuate uranium mobility. Documented cases convincingly demonstrate that excavation and pump-and-treat methods are ineffective for a number of highly contaminated sites. There is growing concern that use of conventional PRB?s, such as zero-valent iron, are a temporary solution to a problem that will persist for thousands of years. Alternatives to the standard treatment methods are therefore warranted. The core objective of our research is to demonstrate that a phosphorus amendment strategy will result in a reduction of dissolved uranium to below the proposed drinking water standard. Our hypothesis is that long-chain polyphosphate compounds forestall precipitation of sparingly soluble uranyl phosphate compounds, which is key to preventing fouling of wells at the point of injection. Our other fundamental objective is to synthesize and correctly characterize the uranyl phosphate phases that form in the geochemical conditions under consideration. This report summarizes work conducted at the University of Notre Dame through November of 2003 under DOE grant DE-FG07-02ER63489, which has been funded since September, 2002. The objectives at Notre Dame are development of synthesis techniques for uranyl phosphate phases, together with detailed structural and chemical characterization of the myriad of uranyl phosphate phases that may form under geochemical conditions under consideration

  2. Electrosprayed calcium phosphate coatings for biomedical purposes.

    OpenAIRE

    Leeuwenburgh, S.C.G.

    2006-01-01

    In this thesis, the suitability of the Electrostatic Spray Deposition (ESD) technique was studied for biomedical purposes, i.e., deposition of calcium phosphate (CaP) coatings onto titanium substrates. Using ESD, which is a simple and cheap deposition method for inorganic and organic coatings, it was possible to obtain thin CaP layers with an extremely wide range of chemical and morphological characteristics. Various CaP phases and phase mixtures were deposited and a broad diversity of coatin...

  3. Biodiesel production over copper vanadium phosphate

    International Nuclear Information System (INIS)

    Chen, Lei; Yin, Ping; Liu, Xiguang; Yang, Lixia; Yu, Zhongxi; Guo, Xin; Xin, Xinquan

    2011-01-01

    In the present study, copper vanadium phosphate (CuVOP) with three-dimensional network structure was synthesized by hydrothermal method, and was characterized by Infrared spectrum (IR), elemental analysis (EA), EDXRF (energy dispersive X ray fluorescence) etc. Moreover, soybean oil was used as feedstock for producing biodiesel, and biodiesel was produced by CuVOP-catalyzed transesterification process. Response surface methodology was employed to statistically evaluate and optimize the conditions for the maximum conversion to biodiesel, and the effects of amount of catalyst, ratio of methanol to oil, reaction time and reaction temperature were investigated by the 2 4 full-factorial central composite design. The maximum conversion is obtained at amount of catalyst of 1.5%, methanol/oil molar ratio of 6.75, reaction temperature of 65 o C and reaction time of 5 h. Copper vanadium phosphate CuVOP resulted very active in the transesterification reaction for biodiesel production. -- Research highlights: → Copper vanadium phosphate CuVOP with three-dimensional network structure was prepared successfully. Moreover, for the transesterification reaction of soybean oil with methanol under atmospheric pressure, CuVOP had higher catalytic activity and the effects of production conditions such as amount of catalysts etc. were analyzed by response surface methodology.

  4. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

    Science.gov (United States)

    Cross, Megan; Biberacher, Sonja; Park, Suk-Youl; Rajan, Siji; Korhonen, Pasi; Gasser, Robin B; Kim, Jeong-Sun; Coster, Mark J; Hofmann, Andreas

    2018-04-24

    The opportunistic bacterium Pseudomonas aeruginosa has been recognized as an important pathogen of clinical relevance and is a leading cause of hospital-acquired infections. The presence of a glycolytic enzyme in Pseudomonas, which is known to be inhibited by trehalose 6-phosphate (T6P) in other organisms, suggests that these bacteria may be vulnerable to the detrimental effects of intracellular T6P accumulation. In the present study, we explored the structural and functional properties of trehalose 6-phosphate phosphatase (TPP) in P. aeruginosa in support of future target-based drug discovery. A survey of genomes revealed the existence of 2 TPP genes with either chromosomal or extrachromosomal location. Both TPPs were produced as recombinant proteins, and characterization of their enzymatic properties confirmed specific, magnesium-dependent catalytic hydrolysis of T6P. The 3-dimensional crystal structure of the chromosomal TPP revealed a protein dimer arising through β-sheet expansion of the individual monomers, which possess the overall fold of halo-acid dehydrogenases.-Cross, M., Biberacher, S., Park, S.-Y., Rajan, S., Korhonen, P., Gasser, R. B., Kim, J.-S., Coster, M. J., Hofmann, A. Trehalose 6-phosphate phosphatases of Pseudomonas aeruginosa.

  5. Phosphate phosphors for solid-state lighting

    Energy Technology Data Exchange (ETDEWEB)

    Shinde, Kartik N. [N.S. Science and Arts College, Bhadrawati (India). Dept. of Physics; Swart, H.C. [University of the Orange Free State, Bloemfontein (South Africa). Dept. of Physics; Dhoble, S.J. [R.T.M. Nagpur Univ. (India). Dept. of Physics; Park, Kyeongsoon [Sejong Univ., Seoul (Korea, Republic of). Faculty of Nanotechnology and Advanced Materials Engineering

    2012-07-01

    Essential information for students in researchers working towards new and more efficient solid-state lighting. Comprehensive survey based on the authors' long experience. Useful both for teaching and reference. The idea for this book arose out of the realization that, although excellent surveys and a phosphor handbook are available, there is no single source covering the area of phosphate based phosphors especially for lamp industry. Moreover, as this field gets only limited attention in most general books on luminescence, there is a clear need for a book in which attention is specifically directed toward this rapidly growing field of solid state lighting and its many applications. This book is aimed at providing a sound introduction to the synthesis and optical characterization of phosphate phosphor for undergraduate and graduate students as well as teachers and researchers. The book provides guidance through the multidisciplinary field of solid state lighting specially phosphate phosphors for beginners, scientists and engineers from universities, research organizations, and especially industry. In order to make it useful for a wide audience, both fundamentals and applications are discussed, together.

  6. Radiochemical studies on amorphous zirconium phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Dyer, A; Moores, G E [Salford Univ. (UK). Dept. of Chemistry and Applied Chemistry

    1981-01-01

    Amorphous zirconium phosphate (ZrP) is used in some hemodialysis machines for the regeneration of dialysate. Its function is to adsorb ammonium ions formed by the pretreatment of urea by urease. It also adsorbs Ca, Mg and K ions but leaches phosphate ions which are then removed (along with F/sup -/ ions) by a bed of hydrous zirconium oxide. The sodium form of ZrP is used although other forms have been suggested for use. The work reported here describes some preliminary radiochemical studies on the mechanism of release of phosphate ions and its possible relationship to sodium ion-exchange. /sup 32/P labelled material (HHZrP) was used for elution experiments with deionized water and buffer solutions having the pH's 4.2, 7.0 and 9.2. Buffer solutions used were as supplied by BDH. Elution was at four different temperatures in the range 293 to 363/sup 0/C. In the second series of experiments HHZrP was suspended in a NaCl solution labelled with /sup 22/Na. From this, /sup 22/Na labelled ZrP (NaHZrP) was prepared and eluted in the same way as the HHZrP. Results are given and discussed.

  7. Calcium phosphate cement scaffolds with PLGA fibers.

    Science.gov (United States)

    Vasconcellos, Letícia Araújo; dos Santos, Luís Alberto

    2013-04-01

    The use of calcium phosphate-based biomaterials has revolutionized current orthopedics and dentistry in repairing damaged parts of the skeletal system. Among those biomaterials, the cement made of hydraulic grip calcium phosphate has attracted great interest due to its biocompatibility and hardening "in situ". However, these cements have low mechanical strength compared with the bones of the human body. In the present work, we have studied the attainment of calcium phosphate cement powders and their addition to poly (co-glycolide) (PLGA) fibers to increase mechanical properties of those cements. We have used a new method that obtains fibers by dripping different reagents. PLGA fibers were frozen after lyophilized. With this new method, which was patented, it was possible to obtain fibers and reinforcing matrix which furthered the increase of mechanical properties, thus allowing the attainment of more resistant materials. The obtained materials were used in the construction of composites and scaffolds for tissue growth, keeping a higher mechanical integrity. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Phosphine from rocks: mechanically driven phosphate reduction?

    Science.gov (United States)

    Glindemann, Dietmar; Edwards, Marc; Morgenstern, Peter

    2005-11-01

    Natural rock and mineral samples released trace amounts of phosphine during dissolution in mineral acid. An order of magnitude more phosphine (average 1982 ng PH3 kg rock and maximum 6673 ng PH3/kg rock) is released from pulverized rock samples (basalt, gneiss, granite, clay, quartzitic pebbles, or marble). Phosphine was correlated to hardness and mechanical pulverization energy of the rocks. The yield of PH3 ranged from 0 to 0.01% of the total P content of the dissolved rock. Strong circumstantial evidence was gathered for reduction of phosphate in the rock via mechanochemical or "tribochemical" weathering at quartz and calcite/marble inclusions. Artificial reproduction of this mechanism by rubbing quartz rods coated with apatite-phosphate to the point of visible triboluminescence, led to detection of more than 70 000 ng/kg PH3 in the apatite. This reaction pathway may be considered a mechano-chemical analogue of phosphate reduction from lightning or electrical discharges and may contribute to phosphine production via tectonic forces and processing of rocks.

  9. Fourier transform Raman spectroscopy of synthetic and biological calcium phosphates.

    Science.gov (United States)

    Sauer, G R; Zunic, W B; Durig, J R; Wuthier, R E

    1994-05-01

    Fourier-transform (FT) Raman spectroscopy was used to characterize the organic and mineral components of biological and synthetic calcium phosphate minerals. Raman spectroscopy provides information on biological minerals that is complimentary to more widely used infrared methodologies as some infrared-inactive vibrational modes are Raman-active. The application of FT-Raman technology has, for the first time, enabled the problems of high sample fluorescence and low signal-to-noise that are inherent in calcified tissues to be overcome. Raman spectra of calcium phosphates are dominated by a very strong band near 960 cm-1 that arises from the symmetric stretching mode (v1) of the phosphate group. Other Raman-active phosphate vibrational bands are seen at approximately 1075 (v3), 590 (v4), and 435 cm-1 (v2). Minerals containing acidic phosphate groups show additional vibrational modes. The different calcium phosphate mineral phases can be distinguished from one another by the relative positions and shapes of these bands in the Raman spectra. FT-Raman spectra of nascent, nonmineralized matrix vesicles (MV) show a distinct absence of the phosphate v1 band even though these structures are rich in calcium and phosphate. Similar results were seen with milk casein and synthetic Ca-phosphatidyl-serine-PO4 complexes. Hence, the phosphate and/or acidic phosphate ions in these noncrystalline biological calcium phosphates is in a molecular environment that differs from that in synthetic amorphous calcium phosphate. In MV, the first distinct mineral phase to form contained acidic phosphate bands similar to those seen in octacalcium phosphate. The mineral phase present in fully mineralized MV was much more apatitic, resembling that found in bones and teeth.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. Vertical distribution of dehalogenating bacteria in mangrove sediment and their potential to remove polybrominated diphenyl ether contamination.

    Science.gov (United States)

    Pan, Ying; Chen, Juan; Zhou, Haichao; Farzana, Shazia; Tam, Nora F Y

    2017-11-30

    The removal and degradation of polybrominated diphenyl ethers (PBDEs) in sediments are not clear. The vertical distribution of total and dehalogenating bacteria in sediment cores collected from a typical mangrove swamp in South China and their intrinsic degradation potential were investigated. These bacterial groups had the highest abundances in surface sediments (0-5cm). A 5-months microcosm experiment also showed that surface sediments had the highest rate to remove BDE-47 than deeper sediments (5-30cm) under anaerobic condition. The deeper sediments, being more anaerobic, had lower population of dehalogenating bacteria leading to a weaker BDE-47 removal potential than surface sediments. Stepwise multiple regression analysis indicated that Dehalococcoides spp. were the most important dehalogenating bacteria affecting the anaerobic removal of BDE-47 in mangrove sediments. This is the first study reporting that mangrove sediments harbored diverse groups of dehalogenating bacteria and had intrinsic potential to remove PBDE contamination. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. The flame retardant DE-71 (a mixture of polybrominated diphenyl ethers) inhibits human differentiated thyroid cell function in vitro

    DEFF Research Database (Denmark)

    Kronborg, Thit Mynster; Hansen, Juliana Frohnert; Rasmussen, Åse Krogh

    2017-01-01

    Normal thyroid function is essential for general growth and metabolism, but can be affected by endocrine disrupting chemicals (EDCs). Polybrominated diphenyl ethers (PBDEs) have been used worldwide to reduce flammability in different materials and are suspected to be EDCs. The production...... of the commercial Penta- and OctaBDE mixtures is banned, but DecaBDEs and existing products may leak PBDEs into the environment. Our aim was to investigate the effect of the PentaBDE mixture DE-71 on human thyroid cells in vitro. Primary human thyroid cells were obtained as paraadenomatous tissue and cultured...... in monolayers. The influence of DE-71 on cyclic adenosine monophosphate (cAMP) and thyroglobulin (Tg) production was examined in the culture medium by competitive radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Real-time quantitative PCR analysis of thyroid-specific genes was performed...

  12. The impact of polybrominated diphenyl ether prohibition: A case study on the atmospheric levels in China, Japan and South Korea

    Science.gov (United States)

    Li, Qilu; Li, Jun; Chaemfa, Chakra; Zhang, Gan; Kobara, Yuso; Nam, Jae-Jak; Jones, Kevin C.

    2014-06-01

    The atmosphere is an important medium which could directly reflect the changes of pollutant sources. Worldwide, the commercial products of polybrominated diphenyl ethers (PBDEs) have been officially restricted and subsequently prohibited. For the purpose of evaluating their concentration after prohibition, passive air samplers (PASs) were therefore deployed again across the East Asia during two periods in 2008 after the initial deployment 4 years ago. When compared with the data in 2004, the atmospheric concentrations of PBDEs have declined significantly. Spatially, the PBDE level in China was still the highest, with a mean value of 15.4 pg m- 3, and in Japan was the lowest (2.47 ± 1.12 pg m- 3) in the East Asia. Moreover, the relatively high concentrations were observed at sites where there are electronic or e-waste recycling industries, and this is particularly true in China, suggesting that illegally imported e-waste is still a typical source of PBDEs in this region.

  13. Levels, profile and distribution of Dechloran Plus (DP) and Polybrominated Diphenyl Ethers (PBDEs) in the environment of Pakistan.

    Science.gov (United States)

    Syed, Jabir Hussain; Malik, Riffat Naseem; Li, Jun; Wang, Yan; Xu, Yue; Zhang, Gan; Jones, Kevin C

    2013-11-01

    No scientific data is available on emerging contaminants including Polybrominated Diphenyl Ethers (PBDEs) and Dechloran Plus (DP) levels in the environment in Pakistan. Levels of PBDEs and DP were determined in the soil, sediment and atmospheric samples along the stretch of River Ravi in Punjab Province. Average concentrations of ΣPBDEs in atmosphere, soils and sediments were 36 pg m(-3), 40 ng g(-1) and 640 ng g(-1). BDE-209 was the most abundant PBDE congener, showing that deca-BDE accounts for most of the total PBDE emitted in the environment of Pakistan. Total DP levels were calculated as 88 pg m(-3), 0.8 ng g(-1) and 1.9 ng g(-1) in air, soil and sediment samples, respectively. The lower average fractions of anti-DP showed significant differences to those of the technical mixtures, indicating the lack of DP production source in Pakistan. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Certification of Mass Fractions of Polycyclic Aromatic Hydrocarbons, Organochlorines and Polybrominated Diphenyl Ethers in IAEA-459 Marine Sediment Sample

    International Nuclear Information System (INIS)

    2017-01-01

    This publication describes the production of certified reference material IAEA-459, which is produced following ISO Guides 34:2009 and 35:2006. This certified reference material is a sediment sample with certified mass fractions of polycyclic aromatic hydrocarbons, organochlorines and polybrominated diphenyl ethers. The assigned final values and their associated uncertainties were derived from robust statistics on the results provided by selected laboratories with demonstrated technical and quality competence, following the guidance given in the ISO Guides. The material is used for quality control and assessment of method performance for a number of organic analytes listed in the Stockholm Convention on Persistent Organic Pollutants as well as other pollutants listed as priority substances included in many environment monitoring programmes.

  15. Synthesis of heterocyclic chalcone derivatives and their radical scavenging ability toward 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals

    International Nuclear Information System (INIS)

    Hwang, Kijun; Kim, Hoseok; Kim, Beomtae; Han, Incheol

    2012-01-01

    A series of heterocyclic chalcone derivatives bearing heterocycles such as thiophene or furan ring as an isostere of benzene ring were carefully prepared, and the influence of heterocycles on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities was systematically investigated. Structure-activity relationships (SAR) analysis showed that the activities of thiophene ring-containing chalcones were higher than those of furan ring containing chalcones, and the presence of methyl substituent of heterocyclic ring distinctly affected the activities compared with non-substituted heterocycles in an opposite manner, with the 4'-methyl group of thiophene ring increasing activity and the 3'-methyl group of the furan ring decreasing activity. The distinct isosteric effect of heterocycles (i.e., thiophene or furan ring) on radical scavenging activities of heterocyclic chalcones was distinctly demonstrated in our work

  16. Meroterpenoid and diphenyl ether derivatives from Penicillium sp. MA-37, a fungus isolated from marine mangrove rhizospheric soil.

    Science.gov (United States)

    Zhang, Yi; Li, Xiao-Ming; Shang, Zhuo; Li, Chun-Shun; Ji, Nai-Yun; Wang, Bin-Gui

    2012-11-26

    Penicillium sp. MA-37, which was obtained from the rhizospheric soil of the mangrove plant Bruguiera gymnorrhiza, exhibited different chemical profiles in static and shaken fermentation modes. Three new meroterpenoid derivatives, 4,25-dehydrominiolutelide B (1), 4,25-dehydro-22-deoxyminiolutelide B (2), and isominiolutelide A (3), together with three known ones were characterized from its static fermentation, while three new diphenyl ether derivatives, namely, Δ(1('),3('))-1'-dehydroxypenicillide (4), 7-O-acetylsecopenicillide C (5), and hydroxytenellic acid B (6), along with five related metabolites were isolated from the shaken culture. The structures of these compounds were elucidated on the basis of spectroscopic analysis, and the structure of compound 2 was confirmed by X-ray crystallographic analysis. The absolute configurations of 1-3 and 6 were determined by ECD and modified Mosher's method, respectively. All isolated compounds were evaluated for brine shrimp lethality and antibacterial activity.

  17. Reaction of bis[(2-chlorocarbonylphenyl] Diselenide with Phenols, Aminophenols, and Other Amines towards Diphenyl Diselenides with Antimicrobial and Antiviral Properties

    Directory of Open Access Journals (Sweden)

    Mirosław Giurg

    2017-06-01

    Full Text Available A reaction of bis[(2-chlorocarbonylphenyl] diselenide with various mono and bisnucleophiles such as aminophenols, phenols, and amines have been studied as a convenient general route to a series of new antimicrobial and antiviral diphenyl diselenides. The compounds, particularly bis[2-(hydroxyphenylcarbamoyl]phenyl diselenides and reference benzisoselenazol-3(2H-ones, exhibited high antimicrobial activity against Gram-positive bacterial species (Enterococcus spp., Staphylococcus spp., and some compounds were also active against Gram-negative E. coli and fungi (Candida spp., A. niger. The majority of compounds demonstrated high activity against human herpes virus type 1 (HHV-1 and moderate activity against encephalomyocarditis virus (EMCV, while they were generally inactive against vesicular stomatitis virus (VSV.

  18. Fate of polybrominated diphenyl ethers during cooking of fish in a new model cooking apparatus and a household microwave.

    Science.gov (United States)

    Bendig, Paul; Hägele, Florian; Blumenstein, Marina; Schmidt, Jasmin; Vetter, Walter

    2013-07-10

    Fish is a major source of human exposure to polybrominated diphenyl ethers (PBDEs). Because fish is mainly consumed after cooking, this measure may alter the pattern and amounts of PBDEs that are finally consumed. To investigate this issue, we developed a model cooking apparatus consisting of a small glass bowl and a beaker glass with an exhaust fitted with a polyurethane foam filter connected to a water jet pump. In this model cooking apparatus, fish (1 g) and/or sunflower oil (0.2/0.4 g) spiked with three PBDE congeners was cooked for 30 min. Small amounts of the semi-volatile PBDEs were evaporated from the fish (BDE-47 cooking apparatus proved to be well-suited to study the fate of polyhalogenated compounds in fish during cooking.

  19. HDPE/clay hybrids: the effect of clay modified with poly(diphenyl siloxanes) on thermal and rheological properties

    Energy Technology Data Exchange (ETDEWEB)

    Monasterio, Fernanda E.; Carrera, Maria C.; Erdmann, Eleonora; Destefanis, Hugo A., E-mail: ferelenakq@gmail.co [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), Buenos Aires (Argentina). Inst. de Investigaciones para la Industria Quimica; Pita, Victor J.R.R.; Dias, Marcos L. [Universidade Federal do Rio de Janeiro (IMA/UFRJ), RJ (Brazil). Inst. de Macromoleculas Profa. Eloisa Mano

    2009-07-01

    Poly(diphenyl siloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nano structure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR and TGA/DTG. These siloxane-modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane-modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to HDPE by melt processing to obtain HDPE/clay hybrids which exhibited marked differences in the rheological behavior when compared with neat HDPE. (author)

  20. Levels of polybrominated diphenyl-ethers and polybrominated dioxins in fish, total diet study food groups, and Japanese meals

    Energy Technology Data Exchange (ETDEWEB)

    Ashizuka, Y.; Nakagawa, R.; Hori, T.; Tobiishi, K.; Iida, T. [Fukuoka Inst. of Health and Environmental Sciences, Dazaifu (Japan)

    2004-09-15

    Since they were found in mother's milk and blood in several studies, the polybrominated diphenyl-ethers (PBDEs) and other polybrominated flame-retardants (BFRs) that are used in plastics, electrical appliances, and textiles have been recognized as ubiquitous pollutants. BFRs are precursors of polybrominated dibenzo-p-dioxins/ polybrominated dibenzofurans (PBDD/Fs). Recently, 2,3,7,8-TBDD/Fs and PBDEs have been detected in adipose tissue and blood in Japanese people. Food is naturally suspected. However, there is very few information on food contamination with those brominated compounds in Japan. Therefore, we measured the levels of PBDEs and PBDD/Fs in various fish samples, meal samples, and total diet study (TDS) food groups and estimated Japanese people's dietary intake of PBDD/Fs and PBDEs.

  1. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Binelli, A. [Department of Biology, Via Celoria 26, University of Milan, 20133 Milan (Italy)], E-mail: andrea.binelli@unimi.it; Guzzella, L.; Roscioli, C. [IRSA-CNR, 20047 Brugherio (Milan) (Italy)

    2008-06-15

    Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with {sigma}PBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447 ng g{sup -1} lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47 > -99 > -100 > -209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide. - This study shows the first data of PBDE contamination in freshwater invertebrates from Mediterranean basin.

  2. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy)

    International Nuclear Information System (INIS)

    Binelli, A.; Guzzella, L.; Roscioli, C.

    2008-01-01

    Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with ΣPBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447 ng g -1 lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47 > -99 > -100 > -209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide. - This study shows the first data of PBDE contamination in freshwater invertebrates from Mediterranean basin

  3. Levels and congener profiles of polybrominated diphenyl ethers (PBDEs) in Zebra mussels (D. polymorpha) from Lake Maggiore (Italy).

    Science.gov (United States)

    Binelli, A; Guzzella, L; Roscioli, C

    2008-06-01

    Several congeners of polybrominated diphenyl ethers (PBDEs) were monitored in 14 different sampling stations of Lake Maggiore, the second largest Italian lake in regard to surface, volume and average depth, using the sentinel-organism Zebra mussel (Dreissena polymorpha). Results revealed a moderate contamination with summation operatorPBDE levels (BDE-17, -28, -47, -66, -71, -85, -99, -100, -138, -153, -154, -183, -190 and -209) ranging from 40 to 447ngg(-1) lipid weight which are similar to those found in environments polluted by deposition or atmospheric transport. The general order of decreasing congener contribution to the total load was BDE-47>-99>-100>-209, which closely reflected patterns observed in mussels collected in freshwater ecosystems worldwide.

  4. HDPE/clay hybrids: the effect of clay modified with poly(diphenyl siloxanes) on thermal and rheological properties

    International Nuclear Information System (INIS)

    Monasterio, Fernanda E.; Carrera, Maria C.; Erdmann, Eleonora; Destefanis, Hugo A.; Pita, Victor J.R.R.; Dias, Marcos L.

    2009-01-01

    Poly(diphenyl siloxanes) (PDPhS) were synthesized in presence of organophilic clay in order to modify its nano structure. Two silane monomers were used: dimethoxydiphenylsilane and dichlorodiphenylsilane. The following characterizations were performed for all clays: XRD, FTIR and TGA/DTG. These siloxane-modified clays were more hydrophobic and had enhanced thermal stability. Solvent extraction was carried out in the siloxane-modified clays and the PDPhS soluble fraction analyzed according the molecular weight via GPC. The presence of free and grafted oligomers on clay surface was identified. The modified clays were added to HDPE by melt processing to obtain HDPE/clay hybrids which exhibited marked differences in the rheological behavior when compared with neat HDPE. (author)

  5. Determination of beta-radiation in 14C-labelled biological samples by 2,5-diphenyl-1,3,4-oxadiazole

    International Nuclear Information System (INIS)

    Kiehl, B.; Neumann, R.; Beger, J.

    1991-01-01

    2,5-Diphenyl-1,3,4-oxadiazole (PPD) has been investigated for its suitability as a primary szintillator. This compound can be used together with the secondary szintillator POPOP in toluene solution for the measurement of low-energetic β-radiation in biological samples marked by 14 C. A convenient approach to laboratory syntheses is presented. (orig.) [de

  6. Application of a congener-specific debromination model to study photodebromination, anaerobic microbial debromination, and FE0 reduction of polybrominated diphenyl ethers

    NARCIS (Netherlands)

    Zeng, X.; Simonich, S.L.M.; Robrock, K.R.; Korytar, P.; Alvarez-Cohen, L.; Barofsky, D.F.

    2010-01-01

    A model was used to predict the photodebromination of the BDE-203, 197, 196, and 153, the major components of the octa-polybrominated diphenyl ether (PBDE) technical mixture, as well as BDE-47, and the predicted results were compared to the experimental results. The predicted reaction time profiles

  7. 1,5-Diphenyl-1,4-pentadiene-3-ones and cyclic analogues as antioxidative agents. Synthesis and structure-activity relationship.

    NARCIS (Netherlands)

    Sardjiman, S.S.; Reksohadiprodjo, M.S.; Hakim, L.; van der Goot, H.; Timmerman, H.

    1997-01-01

    A series of 1,5-diphenyl-1,4-pentadiene-3-ones and cyclic analogues with OH-groups in the para position of the phenyl rings and various meta substituents were prepared and their antioxidant activity compared with that of curcumin. Most of them exhibited potent antioxidative activity, especially when

  8. Phosphate Reduction in Emulsifi ed Meat Products: Impact of Phosphate Type and Dosage on Quality Characteristics

    Directory of Open Access Journals (Sweden)

    Seline Glorieux

    2017-01-01

    Full Text Available Phosphate reduction is of important industrial relevance in the manufacturing of emulsifi ed meat products because it may give rise to a healthier product. The eff ect of seven diff erent phosphate types was tested on the physicochemical and quality characteristics to select the most promising phosphate type for further cooked sausage manufacturing. Next, phosphate mass fraction was gradually reduced. Tetrasodium di- or pyrophosphate (TSPP and sodium tripolyphosphate (STPP increased pH, reduced structural properties, resulted in the highest emulsion stability, lowest cooking loss and had litt le eff ect on hardness. Based on the viscoelastic properties, a minimum mass fraction of 0.06 % TSPP was suffi cient to obtain an acceptable quality product. Rheology proved to be a very useful tool to evaluate the quality of meat products, as it gives insight in the structure of the meat product and especially the functional properties of meat proteins. Based on the obtained results, it can be concluded that the current amount of phosphate added to emulsifi ed meat products can be signifi cantly reduced with minimal loss of product quality.

  9. Phosphate Reduction in Emulsified Meat Products: Impact of Phosphate Type and Dosage on Quality Characteristics.

    Science.gov (United States)

    Glorieux, Seline; Goemaere, Olivier; Steen, Liselot; Fraeye, Ilse

    2017-09-01

    Phosphate reduction is of important industrial relevance in the manufacturing of emulsified meat products because it may give rise to a healthier product. The effect of seven different phosphate types was tested on the physicochemical and quality characteristics to select the most promising phosphate type for further cooked sausage manufacturing. Next, phosphate mass fraction was gradually reduced. Tetrasodium di- or pyrophosphate (TSPP) and sodium tripolyphosphate (STPP) increased pH, reduced structural properties, resulted in the highest emulsion stability, lowest cooking loss and had little effect on hardness. Based on the viscoelastic properties, a minimum mass fraction of 0.06% TSPP was sufficient to obtain an acceptable quality product. Rheology proved to be a very useful tool to evaluate the quality of meat products, as it gives insight in the structure of the meat product and especially the functional properties of meat proteins. Based on the obtained results, it can be concluded that the current amount of phosphate added to emulsified meat products can be significantly reduced with minimal loss of product quality.

  10. The variable charge of andisols as affected by nanoparticles of rock phosphate and phosphate solubilizing bacteria

    Science.gov (United States)

    Arifin, M.; Nurlaeny, N.; Devnita, R.; Fitriatin, B. N.; Sandrawati, A.; Supriatna, Y.

    2018-02-01

    Andisols has a great potential as agriculture land, however, it has a high phosphorus retention, variable charge characteristics and high value of zero net charge or pH0. The research is aimed to study the effects of nanoparticles of rock phosphate (NPRP) and biofertilizer (phosphate solubilizing bacteria/PSB) on soil pH, pHo (zero point of charge, ZPC) and organic-C in one subgroup of Andisols, namely Acrudoxic Durudands, Ciater Region West Java. The research was conducted from October 2016 to February 2017 in Soil Physics Laboratory and Laboratory of Soil Chemistry and Fertility, Soil Science Department, Faculty of Agriculture, Universitas Padjadjaran. This experiment used a completely randomized factorial design, consisting of two factors and three replications. The first factor was nanoparticles of rock phosphate consist of 4 doses 0; 25; 50 and 75 g/1 kg soil and the second factor was biofertilizer dose consist of g/1 kg soil and without biofertilizer. Total treatment combinations were 8 with 3 replications, so there were 24 experimental plots. The results showed that in general NPRR and biofertilizer will decrease the value of soil pH throughout the incubation periods. There is an interaction between nanoparticles of rock phosphate and biofertilizer in decreasing pHo in the first month of incubation, but after 4-month incubation period, NPRP increased. Interaction between 75 g nanoparticles of rock phosphate with 1 g biofertilizer/1 kg soil in fourth months of incubation decreased soil organic-C to 3.35%.

  11. Quantification of Hydroxylated Polybrominated Diphenyl Ethers (OH-BDEs), Triclosan, and Related Compounds in Freshwater and Coastal Systems.

    Science.gov (United States)

    Kerrigan, Jill F; Engstrom, Daniel R; Yee, Donald; Sueper, Charles; Erickson, Paul R; Grandbois, Matthew; McNeill, Kristopher; Arnold, William A

    2015-01-01

    Hydroxylated polybrominated diphenyl ethers (OH-BDEs) are a new class of contaminants of emerging concern, but the relative roles of natural and anthropogenic sources remain uncertain. Polybrominated diphenyl ethers (PBDEs) are used as brominated flame retardants, and they are a potential source of OH-BDEs via oxidative transformations. OH-BDEs are also natural products in marine systems. In this study, OH-BDEs were measured in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The 6-OH-BDE 47 congener and its brominated dioxin (1,3,7-tribromodibenzo-p-dioxin) photoproduct were the only OH-BDE and brominated dioxin detected in surface sediments from San Francisco Bay, the anthropogenically impacted coastal site, where levels increased along a north-south gradient. Triclosan, 6-OH-BDE 47, 6-OH-BDE 90, 6-OH-BDE 99, and (only once) 6'-OH-BDE 100 were detected in two sediment cores from San Francisco Bay. The occurrence of 6-OH-BDE 47 and 1,3,7-tribromodibenzo-p-dioxin sediments in Point Reyes National Seashore, a marine system with limited anthropogenic impact, was generally lower than in San Francisco Bay surface sediments. OH-BDEs were not detected in freshwater lakes. The spatial and temporal trends of triclosan, 2,8-dichlorodibenzo-p-dioxin, OH-BDEs, and brominated dioxins observed in this study suggest that the dominant source of OH-BDEs in these systems is likely natural production, but their occurrence may be enhanced in San Francisco Bay by anthropogenic activities.

  12. Quantification of Hydroxylated Polybrominated Diphenyl Ethers (OH-BDEs, Triclosan, and Related Compounds in Freshwater and Coastal Systems.

    Directory of Open Access Journals (Sweden)

    Jill F Kerrigan

    Full Text Available Hydroxylated polybrominated diphenyl ethers (OH-BDEs are a new class of contaminants of emerging concern, but the relative roles of natural and anthropogenic sources remain uncertain. Polybrominated diphenyl ethers (PBDEs are used as brominated flame retardants, and they are a potential source of OH-BDEs via oxidative transformations. OH-BDEs are also natural products in marine systems. In this study, OH-BDEs were measured in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The 6-OH-BDE 47 congener and its brominated dioxin (1,3,7-tribromodibenzo-p-dioxin photoproduct were the only OH-BDE and brominated dioxin detected in surface sediments from San Francisco Bay, the anthropogenically impacted coastal site, where levels increased along a north-south gradient. Triclosan, 6-OH-BDE 47, 6-OH-BDE 90, 6-OH-BDE 99, and (only once 6'-OH-BDE 100 were detected in two sediment cores from San Francisco Bay. The occurrence of 6-OH-BDE 47 and 1,3,7-tribromodibenzo-p-dioxin sediments in Point Reyes National Seashore, a marine system with limited anthropogenic impact, was generally lower than in San Francisco Bay surface sediments. OH-BDEs were not detected in freshwater lakes. The spatial and temporal trends of triclosan, 2,8-dichlorodibenzo-p-dioxin, OH-BDEs, and brominated dioxins observed in this study suggest that the dominant source of OH-BDEs in these systems is likely natural production, but their occurrence may be enhanced in San Francisco Bay by anthropogenic activities.

  13. Exposure of alveolar macrophages to polybrominated diphenyl ethers suppresses the release of pro-inflammatory products in vitro.

    Science.gov (United States)

    Hennigar, Stephen R; Myers, Jay L; Tagliaferro, Anthony R

    2012-04-01

    Inhalation of chemical pollutants has been associated with a reduced immune response in humans. Inhalation of dust is a major route of exposure for one endocrine-disrupting chemical and suspected xenoestrogen, polybrominated diphenyl ethers (PBDEs); however, the impact of PBDEs on immune function is unclear. The objective of this study was to investigate the action of PBDEs on cytokine and eicosanoid release by alveolar macrophages and determine whether the effects are mediated via the estrogen receptor. The production of tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β, IL-10 and prostaglandin E(2) (PGE(2)) by porcine alveolar macrophages exposed to different concentrations of the pentabrominated diphenyl ether mixture, DE-71, were measured; cells were also exposed to varying concentrations of 17β-estradiol and the selective estrogen receptor-modulating agent, tamoxifen. Cells exposed to PBDEs released significantly less pro-inflammatory cytokines (TNF-α and IL-6) and PGE(2) compared with controls; IL-1β and IL-10 were not detected in the culture medium. Cells exposed to 17β-estradiol released significantly less TNF-α compared with controls, an effect that was reversed by the addition of tamoxifen; tamoxifen had no effect on the inhibition of TNF-α release by PBDEs. Although the suppression of TNF-α with DE-71 was similar to that of estrogen, the inhibitory effects of DE-71 were not found to be dependent on the estrogen receptor. Findings of this study suggest that chronic exposure to PBDEs suppressed innate immunity in vitro. Whether the immunosuppressant effects of PBDEs occur in vivo, remains to be determined.

  14. Organoselenium compounds prevent hyperphosphorylation of cytoskeletal proteins induced by the neurotoxic agent diphenyl ditelluride in cerebral cortex of young rats

    International Nuclear Information System (INIS)

    Moretto, M.B.; Funchal, C.; Zeni, G.; Rocha, J.B.T.; Pessoa-Pureur, R.

    2005-01-01

    In this work we investigated the protective ability of the selenium compounds ebselen and diphenyl diselenide against the effect of diphenyl ditelluride on the in vitro incorporation of 32 P into intermediate filament (IF) proteins from slices of cerebral cortex of 17-day-old rats. We observed that ditelluride in the concentrations of 1, 15 and 50 μM induced hyperphosphorylation of the high-salt Triton insoluble neurofilament subunits (NF-M and NF-L), glial fibrillary acidic protein (GFAP) and vimentin, without altering the immunocontent of these proteins. Concerning the selenium compounds, diselenide (1, 15 and 50 μM) did not induce alteration of the in vitro phosphorylation of the IF proteins. Otherwise, ebselen induced an altered in vitro phosphorylation of the cytoskeletal proteins in a dose-dependent manner. At intermediate concentrations (15 and 30 μM) it increased the in vitro phosphorylation even though, at low (5 μM) or high (50 and 100 μM) concentrations this compound was ineffective in altering the activity of the cytoskeletal-associated phosphorylating system. In addition, 15 μM diselenide and 5 μM ebselen, presented a protective effect against the action of ditelluride, on the phosphorylation of the proteins studied. Considering that hyperphosphorylation of cytoskeletal proteins is associated with neuronal dysfunction and neurodegeneration, it is probable that the effects of ditelluride could be related to the remarkable neurotoxicity of this organic form of tellurium. Furthermore the neuroprotective action of selenium compounds against tellurium effects could be a promising route to be exploited for a possible treatment of organic tellurium poisoning

  15. Effects of education on low-phosphate diet and phosphate binder intake to control serum phosphate among maintenance hemodialysis patients: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Eunsoo Lim

    2018-03-01

    Full Text Available Background : For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. Methods : We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48 or a control group (n = 22. We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. Results : The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0% patients achieved the primary goal, as compared with 16 (72.7% in the control group (P = 0.430. The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087, but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851. However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193. The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363 nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569. Conclusion : Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy.

  16. Research and engineering assessment of biological solubilization of phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, R.D.; McIlwain, M.E.; Losinski, S.J.; Taylor, D.D.

    1993-03-01

    This research and engineering assessment examined a microbial phosphate solubilization process as a method of recovering phosphate from phosphorus containing ore compared to the existing wet acid and electric arc methods. A total of 860 microbial isolates, collected from a range of natural environments were tested for their ability to solubilize phosphate from rock phosphate. A bacterium (Pseudomonas cepacia) was selected for extensive characterization and evaluation of the mechanism of phosphate solubilization and of process engineering parameters necessary to recover phosphate from rock phosphate. These studies found that concentration of hydrogen ion and production of organic acids arising from oxidation of the carbon source facilitated microbial solubilization of both pure chemical insoluble phosphate compounds and phosphate rock. Genetic studies found that phosphate solubilization was linked to an enzyme system (glucose dehydrogenase). Process-related studies found that a critical solids density of 1% by weight (ore to liquid) was necessary for optimal solubilization. An engineering analysis evaluated the cost and energy requirements for a 2 million ton per year sized plant, whose size was selected to be comparable to existing wet acid plants.

  17. The Oxygen Isotopic Composition of Phosphate: A Tracer for Phosphate Sources and Cycling

    Energy Technology Data Exchange (ETDEWEB)

    Mclaughlin, K. [Southern California Coastal Water Research Project, Costa Mesa, University of California, CA (United States); Young, M. B.; Paytan, A.; Kendall, C. [U.S. Geological Survey, University of California, CA (United States)

    2013-05-15

    Phosphorus (P) is a limiting macro-nutrient for primary productivity and anthropogenic P-loading to aquatic ecosystems is one of the leading causes of eutrophication in many ecosystems throughout the world. Because P has only one stable isotope, traditional isotope techniques are not possible for tracing sources and cycling of P in aquatic systems. However, much of the P in nature is bonded to four oxygen (O) atoms as orthophosphate (PO{sub 4}{sup 3-}). The P-O bonds in orthophosphate are strongly resistant to inorganic hydrolysis and do not exchange oxygen with water without biological mediation (enzyme-mediated recycling). Thus, the oxygen isotopic composition of dissolved inorganic phosphate ({delta}{sup 18}O{sub p}) may be used as a tracer for phosphate sources and cycling in aquatic ecosystems. Recently, several studies have been conducted utilizing {delta}{sup 18}O{sub p} as a tracer for phosphate sources and cycling in various aquatic environments. Specifically, work to date indicates that {delta}{sup 18}O{sub p} is useful for determining sources of phosphate to aquatic systems if these sources have unique isotopic signatures and phosphate cycling within the system is limited compared to input fluxes. In addition, because various processes imprint specific fractionation effects, the {delta}{sup 18}O{sub p} tracer can be utilized to determine the degree of phosphorous cycling and processing through the biomass. This chapter reviews several of these studies and discusses the potential to utilize the {delta}{sup 18}O{sub p} of phosphate in rivers and streams. (author)

  18. Dielectric aluminium phosphate thin films. Couches minces dielectriques de phosphate d'aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Daviero, S. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Avinens, C. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Ibanez, A. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France)); Giuntini, J.C. (Lab. Physicochimie des Materiaux Solides, 34 -Montpellier (France)); Philippot, E. (Lab. Physicochimie des Materiaux Solides, 34 - Montpellier (France))

    1993-04-01

    Aluminium phosphate thin films on silicium substrate have been carried out from tributylphosphate and aluminium acetylacetonate precursors in solution through the ''pyrosol'' process. It can be observed a large range of chemical analysis in terms of experimental conditions. These thin films have been characterized by X-ray diffraction and infrared spectrometry. Their electrical characteristics, defined from direct current and alternative current measurements, are quite different to those of the crystallized phosphate and can be explained by P-O and Al-O ''dangling bond'' existence. (orig.).

  19. Reduction of nucleotides by ionizing radiation: uridine 5' phosphate, and cytidine 3' phosphate

    International Nuclear Information System (INIS)

    Box, H.C.; Potter, W.R.; Budzinski, E.E.

    1974-01-01

    Anions formed by the addition of an electron to the uracil base were observed in single crystals of the barium salt of uridine 5' phosphate x irradiated at 4.2 0 K. The hyperfine coupling tensor for the C 6 -H proton was deduced from ENDOR measurements; the principal values are -59.12, -32.92 and -16.24 MHz. Similar measurements were made on single crystals of cytidine 3' phosphate. The principal values for the C 6 -H proton hyperfine coupling in the anion formed on the cytosine base are -59.26, -33.98 and -14.68 MHz. (U.S.)

  20. The reduction of nucleotides by ionizing radiation: uridine 5' phosphate and cytidine 3' phosphate

    International Nuclear Information System (INIS)

    Box, H.C.; Potter, W.R.; Budzinski, E.E.

    1975-01-01

    Anions formed by the addition of an electron to the uracil base were observed in single crystals of the barium salt of uridine 5' phosphate x-irradiated at 4.2 degreeK. The hyperfine coupling tensor for the C 6 --H proton was deduced from ENDOR measurements; the principal values are -59.12, -32.92, and -16.24 MHz. Similar measurements were made on single crystals of cytidine 3' phosphate. The principal values for the C 6 --H proton hyperfine coupling in the anion formed on the cytosine base are -59.26, -33.98, and -14.68 MHz

  1. 31P-Nuclear Magnetic Resonance Determination of Phosphate Compartmentation in Leaves of Reproductive Soybeans (Glycine max L.) as Affected by Phosphate Nutrition 1

    Science.gov (United States)

    Lauer, Michael J.; Blevins, Dale G.; Sierzputowska-Gracz, Hanna

    1989-01-01

    Most leaf phosphorus is remobilized to the seed during reproductive development in soybean. We determined, using 31P-NMR, the effect phosphorus remobilization has on vacuolar inorganic phosphate pool size in soybean (Glycine max [L.] Merr.) leaves with respect to phosphorus nutrition and plant development. Phosphate compartmentation between cytoplasmic and vacuolar pools was observed and followed in intact tissue grown hydroponically, at the R2, R4, and R6 growth stages. As phosphorus in the nutrient solution decreased from 0.45 to 0.05 millimolar, the vacuolar phosphate peak became less prominent relative to cytoplasmic phosphate and hexose monophosphate peaks. At a nutrient phosphate concentration of 0.05 millimolar, the vacuolar phosphate peak was not detectable. At higher levels of nutrient phosphate, as plants progressed from the R2 to the R6 growth stage, the vacuolar phosphate peak was the first to disappear, suggesting that storage phosphate was remobilized to a greater extent than metabolic phosphate. Under suboptimal phosphate nutrition (≤ 0.20 millimolar), the hexose monophosphate and cytoplasmic phosphate peaks declined earlier in reproductive development than when phosphate was present in optimal amounts. Under low phosphate concentrations (0.05 millimolar) cytoplasmic phosphate was greatly reduced. Carbon metabolism was coincidently disrupted under low phosphate nutrition as shown by the appearance of large, prominent starch grains in the leaves. Cytoplasmic phosphate, and leaf carbon metabolism dependent on it, are buffered by vacuolar phosphate until late stages of reproductive growth. Images Figure 4 PMID:16666705

  2. Occupational radiation risks in conveyance of bulk phosphate and potash

    International Nuclear Information System (INIS)

    Grof, Y.; Even, O.; Schlesinger, T.; Margaliot, M.

    1996-01-01

    The issue of occupational ionizing radiation risks encountered in the conveyance and storage of Phosphates and Potash as loose cargo got very minor attention from the national health and occupational safety authorities in the world. In Israel, the Phosphates include an average 100- 150 ppm of Uranium in equilibrium with its daughters, while in Phosphates produced in most other countries the inaction reaches regularly only few ppm up to 50 ppm. Because of the high content of the Uranium in the Phosphate in Israel we must take into consideration the radiological implications involved in the handling of this mineral. The radiological implications of handling Potash are less significant but can not be neglected as we demonstrate bellow In this presentation we will estimate the occupational radiological risks involved in the storing and transportation of Phosphate and Potash. Note, that the main risk in working with Phosphate and Potash is the risk from the dust itself (authors)

  3. Phosphate removal from digested sludge supernatant using modified fly ash.

    Science.gov (United States)

    Xu, Ke; Deng, Tong; Liu, Juntan; Peng, Weigong

    2012-05-01

    The removal of phosphate in digested sludge supernatant by modified coal fly ash was investigated in this study. Modification of the fly ash by the addition of sulfuric acid could significantly enhance its immobilization ability. The experimental results also showed that adsorption of phosphate by the modified fly ash was rapid with the removal percentage of phosphate reaching an equilibrium of 98.62% in less than 5 minutes. The optimum pH for phosphate removal was 9 and the removal percentage increased with increasing adsorbent dosage. The effect of temperature on phosphate removal efficiency was not significant from 20 to 40 degrees C. X-ray diffraction and scanning electron microscope analyses showed that phosphate formed an amorphous precipitate with water-soluble calcium, aluminum, and iron ions in the modified fly ash.

  4. Occupational radiation risks in conveyance of bulk phosphate and potash

    Energy Technology Data Exchange (ETDEWEB)

    Grof, Y; Even, O; Schlesinger, T; Margaliot, M [Israel Atomic Energy Commission, Yavne (Israel). Soreq Nuclear Research Center

    1996-12-01

    The issue of occupational ionizing radiation risks encountered in the conveyance and storage of Phosphates and Potash as loose cargo got very minor attention from the national health and occupational safety authorities in the world. In Israel, the Phosphates include an average 100- 150 ppm of Uranium in equilibrium with its daughters, while in Phosphates produced in most other countries the inaction reaches regularly only few ppm up to 50 ppm. Because of the high content of the Uranium in the Phosphate in Israel we must take into consideration the radiological implications involved in the handling of this mineral. The radiological implications of handling Potash are less significant but can not be neglected as we demonstrate bellow In this presentation we will estimate the occupational radiological risks involved in the storing and transportation of Phosphate and Potash. Note, that the main risk in working with Phosphate and Potash is the risk from the dust itself (authors).

  5. Reducing the cadmium content of crude phosphates and mineral fertilizers

    Energy Technology Data Exchange (ETDEWEB)

    Plessen, H von; Schimmel, G

    1987-10-01

    Crude sedimentary phosphates generally contain cadmium together with traces of other heavy metals. These Cd traces generally end up in fertilizers produced from the crude phosphates. Processes have therefore been developed to separate the Cd from the crude phosphate or from the crude phosphoric acids arising therefrom as intermediates. In this way, the Cd content of the crude phosphate can be reduced to less the 10% of its original value, and to 50% thereof by extractive treatment with acidic calcium nitrate solution. Older calcination processes for crude phosphate have been improved to give residual Cd contents of 10 to 50% at temperatures of 800 to 1000/sup 0/C. Cadmium can be removed almost quantitatively from crude phosphate by means of dialkyl dithiophosphoric acid esters by extraction, binding to adsorbents, or ion flotation. Cadmium can be extracted from crude acids in high yield by long-chained amines. After partial neutralization of the crude acids, precipitation as cadmium sulphide is also possible.

  6. Preparation of Porous Calcium Phosphate Bioceramic

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Porous calcium phosphate ceramics were prepared by slip casting and molding method respectively. By these two different methods, different microstructures can be got. By slip casting method, the pore size was 100- 350μm and 20- 80μm; pores were opened, interconnected and ball-like; the grain size was 2- 4 μm.By molding method, the pore size was 100-500 μm and 1-10μm; the grain size was 2-8μm. By slip casting method regular and interconnected pores can be got. By molding method the porosity and strength can be adjusted easily.

  7. Neonatal jaundice and glucose-6-phosphate dehydrogenase

    OpenAIRE

    Leite, Amauri Antiquera [UNESP

    2010-01-01

    A deficiência de glicose-6-fosfato desidrogenase em neonatos pode ser a responsável pela icterícia neonatal. Este comentário científico é decorrente do relato sobre o tema publicado neste fascículo e que preocupa diversos autores de outros países em relação às complicações em neonatos de hiperbilirrubinemia, existindo inclusive proposições de alguns autores em incluir o teste para identificar a deficiência de glicose-6-fosfato desidrogenase nos recém-nascidos.Glucose-6-phosphate dehydrogenase...

  8. Preparation and characterization of bioceramics produced from calcium phosphate cements

    Energy Technology Data Exchange (ETDEWEB)

    Andriotis, O.; Katsamenis, O.L. [Department of Materials Science, University of Patras, 26504, Patras (Greece); Mouzakis, D.E. [Technological Educational Institute of Larisa, Department of Mechanical Engineering, T.E.I of Larissa, 411 10, Larissa (Greece); Bouropoulos, N. [Foundation for Research and Technology, Hellas, Institute of Chemical Engineering and High Temperature Chemical Processes, FORTH/ICE-HT, P.O. Box 1414, 26504 Rio Patras (Greece)

    2010-03-15

    The present work reports a method for preparing calcium phosphate ceramics by calcination of calcium phosphate cements composed mainly of calcium deficient hydroxyapatite (CDHA). It was found that hardened cements calcinied at temperatures from to 600 to 1300 C were transformed to tricalcium phosphates. Moreover the compressive strength was determined and porosity was estimated as a function of the calcination temperature. (copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  9. Preparation and Characterization of Porous Calcium Phosphate Bioceramics

    Institute of Scientific and Technical Information of China (English)

    Honglian Dai; Xinyu Wang; Yinchao Han; Xin Jiang; Shipu Li

    2011-01-01

    β-tricalcium phosphate (β-TCP) powder and Na2O-CaO-MgO-P2O5 glass binder were synthesized and mixed, and then the biodegradable porous calcium phosphate ceramics were successfully prepared by foaming and sintering at 850℃. The as-prepared ceramics possess a high porosity with partial three-dimension interconnected macro- and micro-pores. As in vitro experiment testified, the calcium phosphate ceramics (CPCs) has good degradability.

  10. Immobilization of transition metal ions on zirconium phosphate monolayers

    International Nuclear Information System (INIS)

    Melezhik, A.V.; Brej, V.V.

    1998-01-01

    It is shown that ions of transition metals (copper, iron, vanadyl, titanium) are adsorbed on zirconium phosphate monolayers. The zirconium phosphate threshold capacity corresponds to substitution of all protons of hydroxyphosphate groups by equivalent amounts of copper, iron or vanadyl. Adsorption of polynuclear ions is possible in case of titanium. The layered substance with specific surface up to 300 m 2 /g, wherein ultradispersed titanium dioxide particles are intercalirated between zirconium-phosphate layers, is synthesized

  11. Characterization of the denitrifying fraction of phosphate accumulating organisms in biological phosphate removal

    DEFF Research Database (Denmark)

    Meinhold, Jens; Filipe, Carlos D.M.; Daigger, Glen T.

    1999-01-01

    fractions of PAO are performed and compared. This study extends on previously reported results (Kerrn-Jespersen and Henze, 1993) in that the pH was controlled to around pH 7 to assure that phosphate precipitation was minimal, and in the measurement of PHB and PHV. With regards to the latter, the paper also...

  12. Determination of radioactivity in Chinese phosphate rock and fertilizer

    International Nuclear Information System (INIS)

    Chen Jingjian; Zhu Yongyi; Yang Juncheng

    1993-01-01

    The presented paper reported the radioactivity of U-238, Ra-226, Th-232 and K-40 in Chinese phosphate rocks by gamma spectrographic analysis during 1985-1990. The results showed that the decay chain of U-238-Ra-226 was the main source of radionuclides in phosphate rocks. The radionuclides in phosphate fertilizer differed from the forms of phosphate fertilizer. U-238 was the most important radionuclide in phosphoric compound fertilizer. The transfer rate of radionuclides was also estimated. (2 figs., 1 tab.)

  13. Aqueous phosphate removal using nanoscale zero-valent iron

    International Nuclear Information System (INIS)

    Almeelbi, Talal; Bezbaruah, Achintya

    2012-01-01

    Nanoscale zero-valent iron (NZVI) particles have been used for the remediation of a wide variety of contaminants. NZVI particles have high reactivity because of high reactive surface area. In this study, NZVI slurry was successfully used for phosphate removal and recovery. Batch studies conducted using different concentrations of phosphate (1, 5, and 10 mg PO 4 3− -P/L with 400 mg NZVI/L) removed ∼96 to 100 % phosphate in 30 min. Efficacy of the NZVI in phosphate removal was found to 13.9 times higher than micro-ZVI (MZVI) particles with same NZVI and MZVI surface area concentrations used in batch reactors. Ionic strength, sulfate, nitrate, and humic substances present in the water affected in phosphate removal by NZVI but they may not have any practical significance in phosphate removal in the field. Phosphate recovery batch study indicated that better recovery is achieved at higher pH and it decreased with lowering of the pH of the aqueous solution. Maximum phosphate recovery of ∼78 % was achieved in 30 min at pH 12. The successful rapid removal of phosphate by NZVI from aqueous solution is expected to have great ramification for cleaning up nutrient rich waters.

  14. Reduction of Diphenyl Diselenide and Analogs by Mammalian Thioredoxin Reductase Is Independent of Their Gluthathione Peroxidase-Like Activity: A Possible Novel Pathway for Their Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    João Batista Teixeira Rocha

    2010-10-01

    Full Text Available Since the successful use of the organoselenium drug ebselen in clinical trials for the treatment of neuropathological conditions associated with oxidative stress, there have been concerted efforts geared towards understanding the precise mechanism of action of ebselen and other organoselenium compounds, especially the diorganyl diselenides such as diphenyl diselenide, and its analogs. Although the mechanism of action of ebselen and other organoselenium compounds has been shown to be related to their ability to generally mimic native glutathione peroxidase (GPx, only ebselen however has been shown to serve as a substrate for the mammalian thioredoxin reductase (TrxR, demonstrating another component of its pharmacological mechanisms. In fact, there is a dearth of information on the ability of other organoselenium compounds, especially diphenyl diselenide and its analogs, to serve as substrates for the mammalian enzyme thioredoxin reductase. Interestingly, diphenyl diselenide shares several antioxidant and neuroprotective properties with ebselen. Hence in the present study, we tested the hypothesis that diphenyl diselenide and some of its analogs (4,4’-bistrifluoromethyldiphenyl diselenide, 4,4’-bismethoxy-diphenyl diselenide, 4.4’-biscarboxydiphenyl diselenide, 4,4’-bischlorodiphenyl diselenide, 2,4,6,2’,4’,6’-hexamethyldiphenyl diselenide could also be substrates for rat hepatic TrxR. Here we show for the first time that diselenides are good substrates for mammalian TrxR, but not necessarily good mimetics of GPx, and vice versa. For instance, bis-methoxydiphenyl diselenide had no GPx activity, whereas it was a good substrate for reduction by TrxR. Our experimental observations indicate a possible dissociation between the two pathways for peroxide degradation (either via substrate for TrxR or as a mimic of GPx. Consequently, the antioxidant activity of diphenyl diselenide and analogs can be attributed to their capacity to be

  15. Phosphate analysis of natural sausage casings preserved in brines with phosphate additives as inactivating agent - Method validation.

    Science.gov (United States)

    Wijnker, J J; Tjeerdsma-van Bokhoven, J L M; Veldhuizen, E J A

    2009-01-01

    Certain phosphates have been identified as suitable additives for the improvement of the microbial and mechanical properties of processed natural sausage casings. When mixed with NaCl (sodium chloride) and used under specific treatment and storage conditions, these phosphates are found to prevent the spread of foot-and-mouth disease and classical swine fever via treated casings. The commercially available Quantichrom™ phosphate assay kit has been evaluated as to whether it can serve as a reliable and low-tech method for routine analysis of casings treated with phosphate. The outcome of this study indicates that this particular assay kit has sufficient sensitivity to qualitatively determine the presence of phosphate in treated casings without interference of naturally occurring phosphate in salt used for brines in which casings are preserved.

  16. Water diffusion in phosphate-containing hydrogels

    International Nuclear Information System (INIS)

    George, K.A.; Wentrup-Byrne, E.; Hill, D.J.T.; Whittaker, A.K.

    2003-01-01

    An understanding of the kinetics and diffusion of liquids through polymeric hydrogels is critical for the successful design and application of these materials in biomedical field, particularly as controlled drug delivery systems. In this study, the mechanisms of water transport and parameters that describe the diffusion process in crosslinked poly(2-hydroxyethylmethacrylate-co-methyloxyethylene phosphate), poly(HEMA-co-MOEP) polymers were investigated. The copolymerisation of HEMA with MOEP was initiated by γ radiolysis with full conversion of monomer to polymer. The sorption of water into the polymers with 0 - 30 mol% MOEP was monitored gravimetrically over a period of 2 - 3 weeks. This study provided an insight into the diffusion mechanism and showed that the PHEMA hydrogel displayed concentration-independent Fickian diffusion. As the concentration of MOEP in the network increased, the diffusion rate and the rigidity of the network also increased in a linear fashion. NMR imaging was used in conjunction with the gravimetric study to elucidate the transport mechanisms, diffusion coefficients and proportionality constants governing the water diffusion in the phosphate-containing polymers. The hydrogels with 3 - 20 mol% MOEP exhibited exponential concentration-dependent Fickian diffusion and the transport mechanism in the system with 30 mol% MOEP was shown to be anomalous. The systems with greater concentrations of MOEP displayed a high degree of fracturing during water sorption and resulted in the ultimate destruction of the cylindrical geometry

  17. Computational Design of Biomimetic Phosphate Scavengers

    DEFF Research Database (Denmark)

    Gruber, Mathias Felix; Wood, Elizabeth Baker; Truelsen, Sigurd Friis

    2015-01-01

    Phosphorus has long been the target of much research, but in recent years the focus has shifted from being limited only to reducing its detrimental environmental impact, to also looking at how it is linked to the global food security. Therefore, the interest in finding novel techniques for phosph......Phosphorus has long been the target of much research, but in recent years the focus has shifted from being limited only to reducing its detrimental environmental impact, to also looking at how it is linked to the global food security. Therefore, the interest in finding novel techniques...... for phosphorus recovery, as well as improving existing techniques, has increased. In this study we apply a hybrid simulation approach of molecular dynamics and quantum mechanics to investigate the binding modes of phosphate anions by a small intrinsically disordered peptide. Our results confirm...... phosphate could be the starting point of new novel technological approaches toward phosphorus recovery, and they represent an excellent model system for investigating the nature and dynamics of functional de novo designed intrinsically disordered proteins....

  18. Environmental prospects of uranium from mineral phosphates

    Energy Technology Data Exchange (ETDEWEB)

    Schnug, Ewald [Technische Univ. Braunschweig (Germany). Faculty 2 - Life Sciences; Haneklaus, Nils [Stuttgart Univ. (Germany). Inst. fuer Kernenergetik und Energiesysteme

    2012-12-15

    Uranium (U) is a natural resource that is found in rock phosphates (P). Each year farmers apply unwittingly 167 t/yr U to their soils by P fertilisation. If extracted and used for electricity generation with state of the art nuclear power plants this amount of U could cover the energy demand of 2.4 x 10{sup 6} average German households. Otherwise this finite resource is wasted. U from P fertilisers is an uncommon contribution of agriculture to climate protection. Using the key to calculate the CO{sub 2} depending German car tax band, 1 kilogram P would be valued with 1.8 Euro. More than that the extraction of U from rock phosphates is an efficient measure to avoid U entering the food chain. In particular translocation processes in soils of fertiliser-applied U by run-off and leaching which result in the contamination of surface waters and finally drinking water can be impeded efficiently. (orig.)

  19. Involvement of reactive oxygen species in brominated diphenyl ether-47-induced inflammatory cytokine release from human extravillous trophoblasts in vitro

    International Nuclear Information System (INIS)

    Park, Hae-Ryung; Kamau, Patricia W.; Loch-Caruso, Rita

    2014-01-01

    Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant compounds. Brominated diphenyl ether (BDE)-47 is one of the most prevalent PBDE congeners found in human breast milk, serum and placenta. Despite the presence of PBDEs in human placenta, effects of PBDEs on placental cell function are poorly understood. The present study investigated BDE-47-induced reactive oxygen species (ROS) formation and its role in BDE-47-stimulated proinflammatory cytokine release in a first trimester human extravillous trophoblast cell line, HTR-8/SVneo. Exposure of HTR-8/SVneo cells for 4 h to 20 μM BDE-47 increased ROS generation 1.7 fold as measured by the dichlorofluorescein (DCF) assay. Likewise, superoxide anion production increased approximately 5 fold at 10 and 15 μM and 9 fold at 20 μM BDE-47 with a 1-h exposure, as measured by cytochrome c reduction. BDE-47 (10, 15 and 20 μM) decreased the mitochondrial membrane potential by 47–64.5% at 4, 8 and 24 h as assessed with the fluorescent probe Rh123. Treatment with 15 and 20 μM BDE-47 stimulated cellular release and mRNA expression of IL-6 and IL-8 after 12 and 24-h exposures: the greatest increases were a 35-fold increased mRNA expression at 12 h and a 12-fold increased protein concentration at 24 h for IL-6. Antioxidant treatments (deferoxamine mesylate, (±)α-tocopherol, or tempol) suppressed BDE-47-stimulated IL-6 release by 54.1%, 56.3% and 37.7%, respectively, implicating a role for ROS in the regulation of inflammatory pathways in HTR-8/SVneo cells. Solvent (DMSO) controls exhibited statistically significantly decreased responses compared with non-treated controls for IL-6 release and IL-8 mRNA expression, but these responses were not consistent across experiments and times. Nonetheless, it is possible that DMSO (used to dissolve BDE-47) may have attenuated the stimulatory actions of BDE-47 on cytokine responses. Because abnormal activation of proinflammatory responses can disrupt trophoblast functions

  20. Involvement of reactive oxygen species in brominated diphenyl ether-47-induced inflammatory cytokine release from human extravillous trophoblasts in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hae-Ryung, E-mail: heaven@umich.edu; Kamau, Patricia W.; Loch-Caruso, Rita

    2014-01-15

    Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant compounds. Brominated diphenyl ether (BDE)-47 is one of the most prevalent PBDE congeners found in human breast milk, serum and placenta. Despite the presence of PBDEs in human placenta, effects of PBDEs on placental cell function are poorly understood. The present study investigated BDE-47-induced reactive oxygen species (ROS) formation and its role in BDE-47-stimulated proinflammatory cytokine release in a first trimester human extravillous trophoblast cell line, HTR-8/SVneo. Exposure of HTR-8/SVneo cells for 4 h to 20 μM BDE-47 increased ROS generation 1.7 fold as measured by the dichlorofluorescein (DCF) assay. Likewise, superoxide anion production increased approximately 5 fold at 10 and 15 μM and 9 fold at 20 μM BDE-47 with a 1-h exposure, as measured by cytochrome c reduction. BDE-47 (10, 15 and 20 μM) decreased the mitochondrial membrane potential by 47–64.5% at 4, 8 and 24 h as assessed with the fluorescent probe Rh123. Treatment with 15 and 20 μM BDE-47 stimulated cellular release and mRNA expression of IL-6 and IL-8 after 12 and 24-h exposures: the greatest increases were a 35-fold increased mRNA expression at 12 h and a 12-fold increased protein concentration at 24 h for IL-6. Antioxidant treatments (deferoxamine mesylate, (±)α-tocopherol, or tempol) suppressed BDE-47-stimulated IL-6 release by 54.1%, 56.3% and 37.7%, respectively, implicating a role for ROS in the regulation of inflammatory pathways in HTR-8/SVneo cells. Solvent (DMSO) controls exhibited statistically significantly decreased responses compared with non-treated controls for IL-6 release and IL-8 mRNA expression, but these responses were not consistent across experiments and times. Nonetheless, it is possible that DMSO (used to dissolve BDE-47) may have attenuated the stimulatory actions of BDE-47 on cytokine responses. Because abnormal activation of proinflammatory responses can disrupt trophoblast functions

  1. Triplet and ground state potential energy surfaces of 1,4-diphenyl-1,3-butadiene: theory and experiment.

    Science.gov (United States)

    Saltiel, J; Dmitrenko, O; Pillai, Z S; Klima, R; Wang, S; Wharton, T; Huang, Z-N; van de Burgt, L J; Arranz, J

    2008-05-01

    Relative energies of the ground state isomers of 1,4-diphenyl-1,3-butadiene (DPB) are determined from the temperature dependence of equilibrium isomer compositions obtained with the use of diphenyl diselenide as catalyst. Temperature and concentration effects on photostationary states and isomerization quantum yields with biacetyl or fluorenone as triplet sensitizers with or without the presence of O(2), lead to significant modification of the proposed DPB triplet potential energy surface. Quantum yields for ct-DPB formation from tt-DPB increase with [tt-DPB] revealing a quantum chain process in the tt --> ct direction, as had been observed for the ct --> tt direction, and suggesting an energy minimum at the (3)ct* geometry. They confirm the presence of planar and twisted isomeric triplets in equilibrium (K), with energy transfer from planar or quasi-planar geometries (quantum chain events from tt and ct triplets) and unimolecular decay (k(d)) from twisted geometries. Starting from cc-DPB, varphi(cc-->tt) increases with increasing [cc-DPB] whereas varphi(cc-->ct) is relatively insensitive to concentration changes. The concentration and temperature dependencies of the decay rate constants of DPB triplets in cyclohexane are consistent with the mechanism deduced from the photoisomerization quantum yields. The experimental DeltaH between (3)tt-DPB* and (3)tp-DPB*, 2.7 kcal mol(-1), is compared with the calculated energy difference [DFT with B3LYP/6-31+G(d,p) basis set]. Use of the calculated DeltaS = 4.04 eu between the two triplets gives k(d) = (2.4-6.4) x 10(7) s(-1), close to 1.70 x 10(7) s(-1), the value for twisted stilbene triplet decay. Experimental and calculated relative energies of DPB isomers on the ground and triplet state surfaces agree and theory is relied upon to deduce structural characteristics of the equilibrated conformers in the DPB triplet state.

  2. The effect of different phosphate ion concentrations and ph of the phosphate buffer on lipase bioproduction by rhizopus oligosporus

    International Nuclear Information System (INIS)

    Haq, I.; Ali, S.; Awan, U.F.; Javed, W.; Mirza, S.

    2005-01-01

    In the present investigation, we report the effect of phosphate ion concentration and different ph of the phosphate buffer (as diluent) on lipase bioproduction by Rhizopus oligosporus. For this purpose, solid state fermentation was employed. Different agricultural by-products such as wheat bran, rice husk, almond meal, soybean meal and sunflower meal were used as substrate. The maximum lipase activity (72.60 U/g) was observed with the almond meal. Addition of phosphate ions (K/sub 2/HPO/sub 4/) influenced the lipase production. The ph of the phosphate buffer (7.0) was found to be effective for higher yield of lipase. (author)

  3. Effect of submarine groundwater discharge containing phosphate on coral calcification

    Science.gov (United States)

    Yasumoto, J.; Yasumoto, K.; Iijima, M.; Nozaki, M.; Asai, K.; Yasumoto, M. H.

    2017-12-01

    It is well known that the anthropogenic eutrophication enriched with various substances including phosphate in coastal waters has resulted in coral degradation. However, to the best of our knowledge, the phosphate threshold value to inhibit the coral calcification has been unclear, due to the unknown mechanisms involved in the inhibition of the calcification by phosphate. In island regions, groundwater is one of the most important clues to transport the nutrients contained in livestock or agricultural wastewaters. However, the actual conditions of coastal pollution with such nutrients have not been understood because of unperceived submarine groundwater discharge (SGD). In this study, to quantify of extremely rapid and localized SGD from Ryukyu limestone aquifer, we investigated the rate and concentration of phosphate of SGD using automated seepage mater in Yoron Island, which is located southern part of Japan. And, to elucidate the inhibition mechanisms for phosphate against coral calcification, we examined its effect on the bottom skeleton formation in primary polyps of Acropora digitifera by using the fluorescence derivatizing reagent having phosphate group (FITC-AA). As a result, the SGD was found to contain 1 to 2 µM of phosphate as much as the concentration in the coastal ground water under agricultural land. Moreover, the amount of phosphate contained in the surface layers of bottom calcareous sands close to the region of SGD were about 5 µmol/g. When the primary polyps were treated with 50 µM of FITC-AA, the bottom skeleton of the primary polyps showed the fluorescence from FITC-AA within a few minutes, suggesting the phosphate binding. Furthermore, when the polyps were treated with 10 µM of FITC-AA, irregular patterns of the elongated skeleton were observed. These results led us to conclude that phosphate is transported via a paracellular pathway to the subcalicoblastic extracellular calcifying medium. These results indicate that the phosphate adsorbed

  4. Exciplex or electroplex emissions from the interface between aromatic diamine and 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline?

    Science.gov (United States)

    Zhu, Haina; Xu, Zheng; Zhang, Fujun; Zhao, Suling; Song, Dandan

    2008-06-01

    Organic light-emitting diodes (OLEDs) have been fabricated which consist of N, N'-diphenyl- N, N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine) (TPD), 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and tris(8-hydroxyquinoline) aluminum (Alq 3). Four emission peaks located at about 401 nm, 425 nm, 452 nm and 480 nm have been obtained in the electroluminescence (EL) spectra of these devices. The former two emissions originate from the exciton emission of TPD molecular. The last two emissions could be attributed to local (LOC) exiplex emission and charge transfer (CT) exiplex emission at the interface between TPD and BCP layers, respectively.

  5. A point mutation of valine-311 to methionine in Bacillus subtilis protoporphyrinogen oxidase does not greatly increase resistance to the diphenyl ether herbicide oxyfluorfen.

    Science.gov (United States)

    Jeong, Eunjoo; Houn, Thavrak; Kuk, Yongin; Kim, Eun-Seon; Chandru, Hema Kumar; Baik, Myunggi; Back, Kyoungwhan; Guh, Ja-Ock; Han, Oksoo

    2003-10-01

    In an effort to asses the effect of Val311Met point mutation of Bacillus subtilis protoporphyrinogen oxidase on the resistance to diphenyl ether herbicides, a Val311Met point mutant of B. subtilis protoporphyrinogen oxidase was prepared, heterologously expressed in Escherichia coli, and the purified recombinant Val311Met mutant protoporphyrinogen oxidase was kinetically characterized. The mutant protoporphyrinogen oxidase showed very similar kinetic patterns to wild type protoporphyrinogen oxidase, with slightly decreased activity dependent on pH and the concentrations of NaCl, Tween 20, and imidazole. When oxyfluorfen was used as a competitive inhibitor, the Val311Met mutant protoporphyrinogen oxidase showed an increased inhibition constant about 1.5 times that of wild type protoporphyrinogen oxidase. The marginal increase of the inhibition constant indicates that the Val311Met point mutation in B. subtilis protoporphyrinogen oxidase may not be an important determinant in the mechanism that protects protoporphyrinogen oxidase against diphenyl ether herbicides.

  6. Standard characterization of phosphate rock samples from the FAO/IAEA phosphate project

    International Nuclear Information System (INIS)

    Binh, Truong; Zapata, F.

    2002-01-01

    Phosphate rocks (PR) are phosphate-bearing minerals that vary widely in their inherent characteristics and consequently their agronomic potential. In the framework of a FAO/IAEA networked research project, the evaluation of the agronomic effectiveness of natural and modified PR products under a variety of soil climate and crop management conditions was carried out. The characterization of phosphate rocks is the first and essential step in evaluating their suitability for direct application. If several PR sources are utilized, standardized methods should be used for comparison purposes to determine their agronomic potential. This paper describes the standard characterization of phosphate rock products utilized in the project, in particular the mineralogical and crystallographic analyses, physical analyses, chemical composition and solubility in conventional reagents. A total of 28 phosphate rock samples from 15 countries were collected and analyzed in specialized laboratories. The data on mineralogy, chemical composition and solubility in conventional reagents are closely interrelated. An arbitrary classification of the reactivity of the PR samples was made based on the solubility indices in conventional reagents. On another hand, the results of the crystallographic parameters, calculated indices of absolute solubility, specific surface and porosity reflect the variability of the physical state and the sample pre-conditioning treatment of the analyzed products. A proper characterization of phosphate rock samples should provide the maximum of basic information that can be obtained in a cost-effective manner in normal chemical laboratories. Based on the results of this characterization, the following determinations are recommended: a description of the sample, major elemental (total P, Ca, Mg) composition, solubility in conventional reagents (neutral ammonium citrate, citric and formic acid) and particle size analysis. The classification of PR samples for direct

  7. Hybrid calcium phosphate coatings for implants

    Science.gov (United States)

    Malchikhina, Alena I.; Shesterikov, Evgeny V.; Bolbasov, Evgeny N.; Ignatov, Viktor P.; Tverdokhlebov, Sergei I.

    2016-08-01

    Monophasic biomaterials cannot provide all the necessary functions of bones or other calcined tissues. It is necessary to create for cancer patients the multiphase materials with the structure and composition simulating the natural bone. Such materials are classified as hybrid, obtained by a combination of chemically different components. The paper presents the physical, chemical and biological studies of coatings produced by hybrid technologies (HT), which combine primer layer and calcium phosphate (CaP) coating. The first HT type combines the method of vacuum arc titanium primer layer deposition on a stainless steel substrate with the following micro-arc oxidation (MAO) in phosphoric acid solution with addition of calcium compounds to achieve high supersaturated state. MAO CaP coatings feature high porosity (2-8%, pore size 5-7 µm) and surface morphology with the thickness greater than 5 µm. The thickness of Ti primer layer is 5-40 µm. Amorphous MAO CaP coating micro-hardness was measured at maximum normal load Fmax = 300 mN. It was 3.1 ± 0.8 GPa, surface layer elasticity modulus E = 110 ± 20 GPa, roughness Ra = 0.9 ± 0.1 µm, Rz = 7.5 ± 0.2 µm, which is less than the titanium primer layer roughness. Hybrid MAO CaP coating is biocompatible, able to form calcium phosphates from supersaturated body fluid (SBF) solution and also stimulates osteoinduction processes. The second HT type includes the oxide layer formation by thermal oxidation and then CaP target radio frequency magnetron sputtering (RFMS). Oxide-RFMS CaP coating is a thin dense coating with good adhesion to the substrate material, which can be used for metal implants. The RFMS CaP coating has thickness 1.6 ± 0.1 µm and consists of main target elements calcium and phosphorus and Ca/P ratio 2.4. The second HT type can form calcium phosphates from SBF solution. In vivo study shows that hybrid RFMS CaP coating is biocompatible and produces fibrointegration processes.

  8. Mercury stabilization in chemically bonded phosphate ceramics

    International Nuclear Information System (INIS)

    Wagh, A. S.; Singh, D.; Jeong, S. Y.

    2000-01-01

    Mercury stabilization and solidification is a significant challenge for conventional stabilization technologies. This is because of the stringent regulatory limits on leaching of its stabilized products. In a conventional cement stabilization process, Hg is converted at high pH to its hydroxide, which is not a very insoluble compound; hence the preferred route for Hg sulfidation to convert it into insoluble cinnabar (HgS). Unfortunately, efficient formation of this compound is pH-dependent. At a high pH, one obtains a more soluble Hg sulfate, in a very low pH range, insufficient immobilization occurs because of the escape of hydrogen sulfide, while efficient formation of HgS occurs only in a moderately acidic region. Thus, the pH range of 4 to 8 is where stabilization with Chemically Bonded Phosphate Ceramics (CBPC) is carried out. This paper discusses the authors experience on bench-scale stabilization of various US Department of Energy (DOE) waste streams containing Hg in the CBPC process. This process was developed to treat DOE's mixed waste streams. It is a room-temperature-setting process based on an acid-base reaction between magnesium oxide and monopotassium phosphate solution that forms a dense ceramic within hours. For Hg stabilization, addition of a small amount ( 2 S or K 2 S is sufficient in the binder composition. Here the Toxicity Characteristic Leaching Procedure (TCLP) results on CBPC waste forms of surrogate waste streams representing secondary Hg containing wastes such as combustion residues and Delphi DETOXtrademark residues are presented. The results show that although the current limit on leaching of Hg is 0.2 mg/L, the results from the CBPC waste forms are at least one order lower than this stringent limit. Encouraged by these results on surrogate wastes, they treated actual low-level Hg-containing mixed waste from their facility at Idaho. TCLP results on this waste are presented here. The efficient stabilization in all these cases is

  9. Concentration of polybrominated diphenyl ethers (PBDEs) in sediment cores of Sundarban mangrove wetland, northeastern part of Bay of Bengal (India)

    Energy Technology Data Exchange (ETDEWEB)

    Binelli, Andrea [Department of Biology, University of Milan, Via Celoria 26, 20133 Milan (Italy)]. E-mail: andrea.binelli@unimi.it; Sarkar, Santosh Kumar [Department of Marine Science, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700 019 (India); Chatterjee, Mousumi [Department of Marine Science, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700 019 (India); Riva, Consuelo [Department of Biology, University of Milan, Via Celoria 26, 20133 Milan (Italy); Parolini, Marco [Department of Biology, University of Milan, Via Celoria 26, 20133 Milan (Italy); Bhattacharya, Bhaskar deb [Department of Marine Science, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700 019 (India); Bhattacharya, Asok Kumar [Department of Marine Science, University of Calcutta, 35 Ballygunge Circular Road, Calcutta 700 019 (India); Satpathy, Kamala Kanta [Indira Gandhi Center for Atomic Research, Environmental and Industrial Safety Section, Safety Group, Kalpakkam 603 102, Tamil Nadu (India)

    2007-08-15

    The paper presents the first comprehensive survey of congener profiles (12 congeners) of polybrominated diphenyl ethers (PBDEs) in core sediment samples (<63 {mu}m) covering seven sites in Sundarban mangrove wetland (India). Gas-chromatographic analyses were carried out in GC-Ms/Ms for tri- to hepta- brominated congeners. Results pointed out a non-homogenous contamination of the wetland with {sigma}{sub 12} PBDE values ranging from 0.08 to 29.03 ng g{sup -1}, reflecting moderate to low contamination closely in conformity to other Asian aquatic environments. The general order of decreasing congener contribution to the total load was: BDE 47 > 99 > 100 > 154, similar to the distribution pattern worldwide. Although tetrabromodiphenyl ether BDE 47 was found in all samples followed by hexabromodiphenyl ether BDE-154, they were not necessarily the dominant congeners. No uniform temporal trend on PBDE levels was recorded probably due to particular hydrological characteristics of the wetland and/on non-homologous inputs from point sources (untreated municipal wastewater and local industries, electronic wastes from the dump sites, etc.) of these compounds. Because of the propensity of PBDEs to accumulate in various compartments of wildlife and human food webs, evaluation of biological tissues should be undertaken as a high priority.

  10. The flame retardant DE-71 (a mixture of polybrominated diphenyl ethers) inhibits human differentiated thyroid cell function in vitro.

    Science.gov (United States)

    Kronborg, Thit Mynster; Hansen, Juliana Frohnert; Rasmussen, Åse Krogh; Vorkamp, Katrin; Nielsen, Claus Henrik; Frederiksen, Marie; Hofman-Bang, Jacob; Hahn, Christoffer Holst; Ramhøj, Louise; Feldt-Rasmussen, Ulla

    2017-01-01

    Normal thyroid function is essential for general growth and metabolism, but can be affected by endocrine disrupting chemicals (EDCs). Polybrominated diphenyl ethers (PBDEs) have been used worldwide to reduce flammability in different materials and are suspected to be EDCs. The production of the commercial Penta- and OctaBDE mixtures is banned, but DecaBDEs and existing products may leak PBDEs into the environment. Our aim was to investigate the effect of the PentaBDE mixture DE-71 on human thyroid cells in vitro. Primary human thyroid cells were obtained as paraadenomatous tissue and cultured in monolayers. The influence of DE-71 on cyclic adenosine monophosphate (cAMP) and thyroglobulin (Tg) production was examined in the culture medium by competitive radioimmunoassay and enzyme-linked immunosorbent assay, respectively. Real-time quantitative PCR analysis of thyroid-specific genes was performed on the exposed cell cultures. PBDE concentrations were determined in cellular and supernatant fractions of the cultures. DE-71 inhibited Tg-release from TSH-stimulated thyrocytes. At 50 mg/L DE-71, mean Tg production was reduced by 71.9% (range: 8.5-98.7%), and cAMP by 95.1% (range: 91.5-98.8%) compared to controls). Expression of mRNA encoding Tg, TPO and TSHr were significantly inhibited (pproduction, respectively, as well as expression of mRNA encoding Tg, TPO and TSHr. Our findings suggest an inhibiting effect of PBDEs on thyroid cells.

  11. Stable carbon isotope analysis (δ13C values) of polybrominated diphenyl ethers and their UV-transformation products

    International Nuclear Information System (INIS)

    Rosenfelder, Natalie; Bendig, Paul; Vetter, Walter

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) are frequently detected in food and environmental samples. We used compound specific isotope analysis to determine the δ 13 C values of individual PBDEs in two technical mixtures. Within the same technical product (DE-71 or DE-79), BDE congeners were the more depleted in 13 C the higher brominated they were. In contrast, the products of light-induced hydrodebromination of BDE 47 and technical DE-79 were more enriched in 13 C because of more stable bonds between 13 C and bromine. As a result, the δ 13 C values of the irradiated solution progressed diametrically compared to those of the technical synthesis. The ratio of the δ 13 C values of BDE 47 to BDE 99 and of BDE 99 to BDE 153 are thus suggested as indicators to distinguish native technical products from transformation products. Ratios 1) is typical of transformation products. - Highlights: → δ 13 C values of PBDEs were determined by means of compound specific isotope analysis. → PBDEs in technical mixtures were the more depleted in 13 C the higher they were brominated. → Solutions of individual PBDEs and technical PBDE mixtures were irradiated by UV light. → δ 13 C values of irradiated PBDEs and technical PBDEs progressed diametrically. → Ratios of the δ 13 C values were used to distinguish native from transformed PBDEs. - Diametrically progressing δ 13 C values in technical mixtures and UV-transformation products of DE-79 may be useful for source appointment of PBDEs in environmental samples

  12. Estimation of the source strength of polybrominated diphenyl ethers based on their diel variability in air in Zurich, Switzerland.

    Science.gov (United States)

    Moeckel, Claudia; Gasic, Bojan; MacLeod, Matthew; Scheringer, Martin; Jones, Kevin C; Hungerbühler, Konrad

    2010-06-01

    Diel (24-h) concentration variations of polybrominated diphenyl ethers (PBDEs) in air were measured in the center of Zurich, Switzerland, and on Uetliberg, a hill about 5 km from the city center. Air samples were collected simultaneously at both sites over 4 h time periods for 3 consecutive days during a stable high pressure system in August 2007. Higher PBDE concentrations in the city compared to the Uetliberg site indicate that Zurich is a likely source of PBDEs to the atmosphere. A multimedia mass balance model was used to (i) explain the diel cycling pattern of PBDE concentrations observed at both sites in terms of dominant processes and (ii) estimate emission rates of PBDEs from the city to the atmosphere. We estimate that Zurich emits 0.4, 6.2, 1.6, and 0.4 kg year(-1) of the PBDE congeners 28, 47, 99, and 100, respectively. On a per-capita basis, these estimates are within the range or somewhat above those obtained in other studies using approaches based on emission factors (EF) and PBDE production, usage, and disposal data, or concentration measurements. The present approach complements emission estimates based on the EF approach and can also be applied to source areas where EFs and PBDE material flows are poorly characterized or unknown, such as electronic waste processing plants.

  13. A combined effect of polybrominated diphenyl ether and aquaculture effluent on growth and antioxidative response of mangrove plants.

    Science.gov (United States)

    Farzana, Shazia; Tam, Nora Fung Yee

    2018-06-01

    Mangrove wetland receives nutrient-rich aquaculture effluent (AE) from nearby farming activities and polybrominated diphenyl ethers (PBDEs) from the production and usage of flame retardants. The effects of BDE-209 (the most common PBDE congener), AE and their combination on two true mangrove species, namely Kandelia obovata and Avicennia marina, were compared in a 6-month microcosm study. Results showed that K. obovata was more sensitive to these contaminants than A. marina, as reflected by its enhanced production of leaf superoxide (O 2 -∗ ) by BDE-209 and root malondialdehyde (MDA) by the combined BDE-209 and AE treatment. The hormesis model showed that the combined effects of BDE-209 and AE on the production of MDA, O 2 -∗ and catalase (CAT) activity in K. obovata and A. marina were antagonistic except root O 2 -∗ in A. marina, but the effects on leaf superoxide dismutase (SOD) activity in K. obovata, and root SOD and peroxidase (POD) activities in A. marina were synergistic. The defense mechanisms differed between treatment and species. The activities of SOD and POD were the main mechanisms to defend K. obovata and A. marina against BDE-209, but CAT in K. obovata and POD in A. marina were more important in defending the combined BDE-209 and AE treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. Exponential increases of the brominated flame retardants, polybrominated diphenyl ethers, in the Canadian Arctic from 1981 to 2000.

    Science.gov (United States)

    Ikonomou, Michael G; Rayne, Sierra; Addison, Richard F

    2002-05-01

    A suite of 37 polybrominated diphenyl ether (PBDE) congeners and all of the homologue groups from mono- to deca-brominated were determined in ringed seal (Phoca hispida) blubber collected from subsistence hunts in the Canadian Arctic in 1981, 1991, 1996, and 2000. Total PBDE (sum(PBDE)) concentrations have increased exponentially over this period in male ringed seals aged 0-15 years. Penta- and hexa-BDEs are increasing at approximately the same rate (t2 = 4.7 and 4.3 years, respectively) and more rapidly than tetra-BDEs (t2 = 8.6 years) and tri-BDEs (t2 = infinity) in this age/sex grouping. In contrast to declining PBDE concentrations since 1997 in human milk from Sweden, sum(PBDE) concentrations in arctic ringed seals continue to increase exponentially similar to worldwide commercial penta-BDE production. PBDE congener profiles in male ringed seals aged 0-15 years from 1991 to 2000 also differ significantly from other aquatic organisms and semipermeable membrane devices collected from temperate coastal regions of British Columbia. While PBDE concentrations are 50 times lower than those of mono-ortho and non-ortho PCBs, and approxiamately 500 times higher than PCDD/Fs, our data indicate that, at current rates of bioaccumulation, PBDEs will surpass PCBs to become the most prevalent organohalogen compound in Canadian arctic ringed seals by 2050.

  15. Polybrominated diphenyl ethers do not affect metamorphosis but alter the proteome of the invasive slipper limpet Crepidula onyx.

    Science.gov (United States)

    Mukherjee, Joy; Po, Beverly H K; Chiu, Jill M Y; Wu, Rudolf S S; Qian, Pei-Yuan; Thiyagarajan, Vengatesen

    2013-08-15

    Man-made polybrominated diphenyl ethers (PBDEs) used as flame retardants in various consumer products may be harmful to marine organisms. Larvae of some marine invertebrates, especially invasive species, can develop resistance to PBDEs through altered protein expression patterns or proteome plasticity. This is the first report of a proteomics approach to study BDE-47 induced molecular changes in the invasive limpet Crepidula onyx. Larvae of C. onyx were cultured for 5 days (hatching to metamorphosis) in the presence of BDE-47 (1 μg L(-1)). Using a 2-DE proteomics approach with triple quadrupole and high-resolution TOF-MS, we showed that BDE-47 altered the proteome structure but not the growth or metamorphosis of C. onyx larvae. We found eight significant differentially expressed proteins in response to BDE-47, deemed the protein expression signature, consisting of cytoskeletal, stress tolerance, metabolism and energy production related proteins. Our data suggest C. onyx larvae have adequate proteome plasticity to tolerate BDE-47 toxicity. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Polybrominated diphenyl ethers (PBDEs) in China: policies and recommendations for sound management of plastics from electronic wastes.

    Science.gov (United States)

    Ni, Kun; Lu, Yonglong; Wang, Tieyu; Shi, Yajuan; Kannan, Kurunthachalam; Xu, Li; Li, Qiushuang; Liu, Shijie

    2013-01-30

    Polybrominated diphenyl ethers (PBDEs), used as flame retardants (BFRs), are incorporated in plastics of most electronic equipment. Among BFR mixtures, deca-BDE is the most widely used commercial additive in the polymer industry and the use of deca-BDE is currently not subject to any restrictions in China. However, debate over environmental and health risks associated with deca-BDE still remains. Regulatory agencies in developed countries have adopted and/or established environmentally sound strategies for the management of potential threat posed by PBDEs to the environment and human health. No regulations or management policies for PBDEs currently exist in China at either central or provincial government levels. Large amounts of plastics containing PBDEs are still in use and must be disposed of after their lifetimes, creating outdoor reservoirs for the future dispersal of PBDEs into the environment. Concerted action is needed not only to regulate the production and use of PBDEs but also to find ways to effectively manage waste electrical and electronic products that contain PBDEs. This article is the first to investigate the policy issues and current problems related to the use of PBDEs in China. In addition, we estimate the mass flows of PBDEs contained in Waste Electrical and Electronic Equipment (WEEE) in China. We suggest alternatives to PBDEs and sound management of plastics used in electrical and electronic equipment (EEE) that contain PBDEs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Dietary intake estimations of polybrominated diphenyl ethers (PBDEs) based on a total diet study in Osaka, Japan.

    Science.gov (United States)

    Akutsu, K; Takatori, S; Nakazawa, H; Hayakawa, K; Izumi, S; Makino, T

    2008-01-01

    This study presents the results of a total diet study performed for estimating the dietary intake of polybrominated diphenyl ethers (PBDEs) in Osaka, Japan. The concentrations of 36 PBDEs were measured in samples from 14 food groups (Groups I-XIV). PBDEs were detected only in Groups IV (oils and fats), V (legumes and their products), X (fish, shellfish, and their products), and XI (meat and eggs) at concentrations of 1.8, 0.03, 0.48, and 0.01 ng g⁻¹, respectively. For an average person, the lower bound dietary intakes of penta- and deca-formulations were estimated to be 46 and 21 ng day⁻¹, respectively. A high proportion of the decabrominated congener (DeBDE-209) was observed in Group IV. To confirm the presence of DeBDE-209 in vegetable oils, an additional analysis was performed using 18 vegetable oil samples. Of these, seven contained ng g⁻¹ levels of DeBDE-209.

  18. Polybrominated diphenyl ethers in the serum and breast milk of the resident population from production area, China.

    Science.gov (United States)

    Jin, Jun; Wang, Ying; Yang, Congqiao; Hu, Jicheng; Liu, Weizhi; Cui, Jian; Tang, Xiaoyan

    2009-10-01

    Polybrominated diphenyl ethers (PBDEs) have been produced in the south coast area of Laizhou Bay, Shandong Province in China, but little is known about the PBDE exposure level of residents to these compounds. We set out to assess potential health risks of PBDEs in the south coast area of the Laizhou Bay by determining the concentrations of PBDEs in serum and breast milk. We measured concentrations of eight PBDE congeners in serum and breast milk. The arithmetic means of Sigma(8)PBDE in pooled serum and breast milk were 613 ng/g lipid and 81.5 ng/g lipid, respectively. The highest concentration for Sigma(8)PBDE in all serum pools was 1830 ng/g lipid from the 41-50 year old female group. BDE-209 was the predominant congener, with the mean concentrations of 403 ng/g lipid in serum and 45.6 ng/g lipid in breast milk, respectively. BDE-209 averagely accounted for 65.8% and 54.2% of the total PBDEs, respectively. Our results suggest that high exposures to PBDEs have led to very high PBDE concentrations in serum and breast milk from the residents living in the south coast area of Laizhou Bay. High PBDE concentrations in human serum, particularly in women, pose a potential public health threat to local residents.

  19. Gamma irradiation of mushrooms, preliminary studies: effect on O-diphenyl oxidase activity and amino acid content

    International Nuclear Information System (INIS)

    Bachman, S.; Gebicka, L.

    1992-01-01

    Mushrooms are a valuable food raw materials because of their nutritional and taste values. Post-harvest ripening, chemical composition (94% water) and possible microbial contamination decrease not only organoleptic and nutritional value, but also the shelf-life. As an objective method of evaluation of irradiated mushrooms we adopted activity determination of o-diphenyl oxidase (o-DPO) which is responsible for discoloration of the edible mushrooms and altered qualitative and quantitative content of amino acids. It was observed that doses up to 2 kGy did not cause any increase in the activity of o-DPO; irradiation also did not affect the taste. Mushrooms irradiated with doses up to 4 kGy were of good quality after 5 days of storage at 4 C, while the control samples (unirradiated) after the same time were considerably changed, probably due too post-harvest ripening. Immediately after exposure the activity of o-DPO increased in proportion to the dose used. During subsequent storage, however, no increase in o-DPO activity was observed. Irradiation used in the range from 0.2 to 0.4 kGy did not affect the nutritional value of the raw material. The results are an additional confirmation that radiation can be used for efficient preservation of mushrooms. (author). 14 refs, 6 tabs

  20. Polychlorinated biphenyls, organochlorinated pesticides, and polybrominated diphenyl ethers in the cerebral cortex of wild river otters (Lontra canadensis)

    Energy Technology Data Exchange (ETDEWEB)

    Basu, Niladri [National Wildlife Research Center, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, K1A 0H3 (Canada)]. E-mail: nbasu@uottawa.ca; Scheuhammer, Anton M. [National Wildlife Research Center, Canadian Wildlife Service, Environment Canada, Ottawa, Ontario, K1A 0H3 (Canada); O' Brien, Mike [Furbearers and Upland Game, Nova Scotia Department of Natural Resources, Kentville, Nova Scotia, B4N 4E5 (Canada)

    2007-09-15

    We measured the levels of ortho-substituted polychlorinated biphenyls (PCB), organochlorinated pesticides (OCP), and polybrominated diphenyl ethers (PBDE) in the cerebral cortex of river otters (Lontra canadensis) trapped from Ontario and Nova Scotia between 2002 and 2004. The mean concentration of total PCBs was 70.9 {+-} 12.1 ng/g l.w., and congeners 153, 180 and 138 accounted for nearly 60% of the sum. The mean concentration of total OCPs was 21.2 {+-} 3.7 ng/g l.w., and hexachlorobenzene (32.6% of total) and DDE (28.1%) accounted for the majority. The mean concentration of total PBDEs was 3.2 {+-} 0.6 ng/g l.w., and congeners 99 (44.9%), 153 (30.5%), and 100 (24.7%) were measured at the indicated percentages. There was no relationship between these residue data and concentrations of brain mercury or neurochemical receptors and enzymes as determined in earlier studies on these same animals. - River otters accumulated PCBs, OCPs, and PBDEs, but at levels below thresholds for neurotoxic effects.