WorldWideScience

Sample records for bidentate neutral organophosphorus

  1. Method for purifying bidentate organophosphorus compounds

    International Nuclear Information System (INIS)

    Schulz, W.W.

    1977-01-01

    Bidentate organophosphorus compounds useful for extracting actinide elements from acidic nuclear waste solutions are purified of undesirable acidic impurities by contacting the compounds with ethylene glycol which preferentially extracts the impurities found in technical grade bidentate compounds

  2. Removal of actinides from nuclear fuel reprocessing waste solutions with bidentate organophosphorus extractants

    International Nuclear Information System (INIS)

    Schulz, W.W.; McIsaac, L.D.

    1975-08-01

    The neutral bidentate organophosphorus reagents DBDECMP (dibutyl-N,N-diethylcarbamylmethylenephosphonate) and its dihexyl analogue DHDECMP are candidate extractants for removal of actinides from certain acidic waste streams produced at the U. S. ERDA Hanford and Idaho Falls sites. Various chemical and physical properties including availability, cost, purification, alpha radiolysis, and aqueous phase solubility of DBDECMP and DHDECMP are reviewed. A conceptual flowsheet employing a 15 percent DBDECMP (or DHDECMP)--CCl 4 extractant for removal (and recovery) of Am and Pu from Hanford's Plutonium Reclamation Facility acid waste stream (CAW solution) was successfully demonstrated in laboratory-scale mixer-settler tests; this extraction scheme can be used to produce an actinide-free waste. A 30 percent DBDECMP-xylene flowsheet is being tested at the Idaho Falls site for removal of U, Np, Pu, and Am from Idaho Chemical Processing Plant first-cycle high-level raffinate to produce an actinide-free (less than 10 nCi alpha activity/gram) waste. (auth)

  3. Effect of diluents on the extraction of actinides and nitric acid by bidentate organophosphorus compounds

    International Nuclear Information System (INIS)

    Rozen, A.M.

    1986-01-01

    The effect of dilutents on extraction by bidentate organophosphorus compounds (diphosphine dioxides, carbamoyl phosphonates, and phosphine oxides) was studied. Figures show the effect of dilutents on the extraction of americium by TOPO and by carbamoylmethylene phosphonate, and the effect of dilutents on the extraction of nitric acid and americium by carbamoylphosphine oxide. Also shown is the effect of dilutents on the extraction of americium by diphenyldioctyl methylenediphosphine dioxide, and the effect of dilutents on the extraction of americium by tetraphenylmethylenediphosphine dioxide. It was concluded that when TBP is added the distribution coefficient of Am increases but the effect of TBP may not be represented by the usual power relationship between the distribution coefficient and the TBP concentration, which would be expected if TBP was found to be very strong but for dilution by DCE it was relatively weak. The observed facts can be explained if it is assumed that TBP reacts with the bridging protons in the complex, which are free for dilution by benzene and are partially occupied when dichlorethane is used

  4. Synergistic extraction of manganese(II) with thenoyltrifluoroacetone and neutral unidentate and bidentate ligands

    International Nuclear Information System (INIS)

    Nakamura, S.; Imura, H.; Suzuki, N.

    1984-01-01

    Synergistic effect of neutral bidentate ligands, L, such as 1,10-phenanthroline(phen), 2,9-dimethyl-1,10-phenanthroline(dmp) and 2,2'-bipyridine(bpy) and of neutral unidentate ligands TBP and TOPO have been studied in the extraction of Mn(II) labelled with 54 Mn using 2-thenoyl-trifluoroacetone(HTTA) in various organic solvents. The following factors play important role in the synergistic extraction involving bidentate ligands: a two-phase partition of bidentate ligands, and their protonation and complex formation with Mn(II) in the aqueous phase. The mixed ligand complex, Mn(TTA) 2 L is formed in all bidentate ligand systems. The adduct formation constant (βsub(s,1)) decreases in the following order: phen (lg βsub(s,1)=12.64)>dmp(11.32)>.bpy(8.54) in the cyclohexane system. This order is ascribed to the bacisity and the steric effect of the bidentate ligands. Organic solvents influence both the adduct formation and the partition of the ligands, and βsub(s,1) decreases in the order cyclohexane > carbon tetrachloride > cholrobenzene approx.= benzene > chloroform. (author)

  5. Thermodynamics of synergistic extraction of hexavalent plutonium with HPMBP and neutral donors: monodentate versus bidentate

    International Nuclear Information System (INIS)

    Lohithakshan, K.V.; Mithapara, P.D.; Pai, S.A.; Aggarwal, S.K.; Jain, H.C.

    1996-01-01

    Synergistic extraction of hexavalent plutonium was studied from HNO 3 medium (0.05 M) with 1-phnyl, 3-methyl, 4-benzoyl, pyrazolone-5 (HPMBP) and different monodentate neutral donors viz. diphenyl sulphoxide (DPSO), tri-n-butyl phosphate (TBP) and tri-n-octyl phosphine oxide (TOPO) using benzene as a diluent. Thermodynamic parameters (ΔG, ΔH, ΔS) evaluated by performing the experiments at various fixed temperatures (288 K to 318 K) were compared with those reported previously for the bidentate neutral donors (DBDECMP, DHDECMP and CMPO). The net enthalpy changes were negative and comparable. The monodentate neutral donors, however, showed a larger decrease in the entropy values. Further, the negative values of enthalpy and entropy changes indicated that the organic adduct formation is an addition reaction as reported ealier for the bidentate donors. (orig.)

  6. Is the stoichiometry of the europium nitrate complexes with neutral organophosphorus extractants be anticipated?

    International Nuclear Information System (INIS)

    Beudaert, Ph.; Lamare, V.; Wipff, G.

    2001-01-01

    Molecular dynamics simulations have been performed in water on europium nitrate complexes with three neutral organophosphorus extractants (TBP, TPPO and CMPO) in order to determine on what criteria it is possible to obtain by simulations the experimental 1:3 stoichiometry in organic solution. This stoichiometry was investigated by progressive saturation of the cation coordination sphere. When the nitrate counter-ions are bidentate, the 1:3 stoichiometry corresponds to the degree of saturation where the interaction energy between europium and water becomes repulsive. Beyond this stoichiometry, complexes with TPPO and CMPO are unstable, although a 1:4 complex with TBP may exist but its formation appears to be energetically unfavored. (author)

  7. Bidentate urea derivatives of p-tert-butyldihomooxacalix[4]arene: neutral receptors for anion complexation.

    Science.gov (United States)

    Marcos, Paula M; Teixeira, Filipa A; Segurado, Manuel A P; Ascenso, José R; Bernardino, Raul J; Michel, Sylvia; Hubscher-Bruder, Véronique

    2014-01-17

    Three new bidentate ureidodihomooxacalix[4]arene derivatives (phenyl 5a, n-propyl 5b, and tert-butyl 5c) were synthesized in four steps from the parent compound p-tert-butyldihomooxacalix[4]arene and obtained in the cone conformation, as shown by NMR studies. The binding ability of these neutral receptors toward spherical, linear, trigonal planar, and tetrahedrical anions was assessed by (1)H NMR and UV-vis titrations. The structures and complexation energies of some complexes were also studied by DFT methods. The data showed that the association constants are strongly dependent on the nature of the substituent (aryl/alkyl) at the urea moiety. In general, for all the receptors, the association constants decrease with decrease of anion basicity. Ph-urea 5a is the best anion receptor, showing the strongest complexation for F(-) (log K(assoc) = 3.10 in CDCl3) and also high binding affinity for the carboxylates AcO(-) and BzO(-). Similar results were obtained by UV-vis studies and were also corroborated by DFT calculations.

  8. Dependence of the extraction capacity of neutral bidentate organophosphorus compounds on their structure: a quantum chemical study

    International Nuclear Information System (INIS)

    Sudarushkin, S.K.; Morgalyuk, V.P.; Tananaev, I.G.; Gribov, L.A.; Myasoedov, B.F.

    2006-01-01

    Correlations between the extraction capacities and molecular structures of organic phosphorus compounds (reagents for extraction of transplutonium elements from spent nuclear fuel) were studied using a quantum chemical approach. The results of calculations are in qualitative agreement with experimental data. The approach proposed can be used for analysis of the extraction properties of all classes of organic phosphorus compounds and also for prediction of the most efficient organic phosphorus extractants with preset properties [ru

  9. Extraction of uranium(6), transuranium elements and europium by bidentate neutral phosphorus- and phosphorus-nitrogen-containing reagents with substituent in methylene bridge

    International Nuclear Information System (INIS)

    Kochetkova, N.E.; Kojro, O.Eh.; Nesterova, N.P.; Medved', T.Ya.; Chmutova, M.K.; Myasoedov, B.F.; Kabachnik, M.I.

    1986-01-01

    The influence of substituents in methylene bridge on solubility, extractivity and selectivity of bidentate neutral phosphorus- and phosphorus-nitrogen-containing reagents in the process of U(6), TUE, Eu extraction has been studied. It is ascertained that hydrogen substitution in the bridge of tetraphenylmethylenediphosphine dioxide (1) causes a decrease in the extractivity of reagent as to TPE, uranium (6) and europium. There is no visible regular relation between basicity and extractivity of substituted reagents. Hydrogen substitution in the bridge of diphenyl[diethylcarbamoylmethyl]phosphine oxide (2) causes a decrease in extractivity of the reagent as to TPE, uranium (6) and europium. In contrast to monodentate neutral reagents, when bidentate neutral reagents are used, sometimes no increase in the reagent extractivity with an increase in its basicity is observed. When fragments restricting the conformation mobility of bidentate reagent molecule are introduced in it (here substituents in methylene bridge), it may result in the violation of the regularity, since of all the factors affecting the reagent extractivity the spatial factor may become the prevailing one. On hydrogen substitution in the bridge of 1 separation factors of practically all (with few exceptions) studied pairs of elements increase. Hydrogen substitution in the bridge of 2 causes an increase in separation factor of U (6) /Am pair and it does not affect the separation factor of Am/Eu pair. Hydrogen substitution in the bridge of 1 and 2 does not result in the preparation of more efficient and considerably more selective reagents for extractive isolation and separation of the elements, but some of the substituted reagents (Cl-substituted 1, for instance) may turn out useful for the element separation

  10. The solvent extraction of zinc, iron, and indium from chloride solutions by neutral organophosphorus compounds

    International Nuclear Information System (INIS)

    Preston, J.S.; Du Preez, A.C.

    1985-01-01

    The preparation of several neutral organophosphorus compounds and their evaluation as selective extractants for zinc in chloride media are described. The compounds belong to the series trialkyl phosphates (RO) 3 PO, dialkyl alkylphosphonates R'PO(OR) 2 , alkyl dialkylphosphinates R 2 'PO(OR), and trialkyl-phosphine oxides R 3 'PO. They were characterized by measurement of their physical properties (melting and boiling points, refractive indices, and densities), and their purities were confirmed by osmometric determination of their molecular masses; by carbon and hydrogen microanalysis; by the titrimetric determination of acidic impurities; and, for liquid products, by comparison of their experimental molar refractivities with empirical values. Metal-distribution equilibria were determined for solutions of the extractants in xylene and aqueous phase containing 0,5 to 5,0 M sodium chloride. Moderately good selectivities were shown for zinc(II) over iron(III), and excellent selectivities were shown for zinc(II) over iron(II), copper(II), lead(II), and cadmium(II). The extraction of indium(III) was similar to that of zinc(II). The extraction of zinc(III), iron(III), and indium(III) increased markedly through the series. (RO) 3 PO 2 2 'PO(OR) 3 'PO. The incorporation of phenyl groups into the compounds led to weaker extraction. The extracted complexes of zinc(II), iron(III), and indium(III) have the stoichiometries ZnCl 2 L 2 ,FeCl 3 L 2 (H 2 O), and InCl 3 L 2 (H 2 O) respectively, where L represents the neutral organophosphorus compound

  11. Influence of the nature of the components of extraction systems used for the extraction of radionuclides on the interfacial tension. II. Influence of the structure of neutral organophosphorus reagents

    International Nuclear Information System (INIS)

    Shmidt, V.S.; Nikitin, S.D.

    1984-01-01

    Isotherms of the interfacial tension were obtained on the interfaces between water or 3 M HNO 3 and solutions of various neutral organophosphorus compounds (NOPC). The values of the work of adsorption W and the standard free energy of adsorption Δμ/sup theta/ of these compounds on the interface from the organic phase were calculated. It was shown that linear dependence of W and Δμ/sup theta/ on the sum of the Kabachnik parameters sigmaΣ/sub Phi/ of the substituents at the phosphorus atom in the molecules of these extraction reagents are observed; this is an indication of the possibility of using the principle of linear free energy ratios (LFE) for predicting the interfacial activity of NOPC of various structures

  12. The organophosphorus extractants

    International Nuclear Information System (INIS)

    Zaoul, B.; Attou, M.; Azzouz, A.

    1989-07-01

    This work consists in a bibliographic review dealing with phosphorus and organophosphorus compounds chemistry and especially with the main extracting agents used in uranium ore treatment. In this context, a special interest is devoted to TBP, D 2 EHPA and TOPO. The content of this work is based on a large bibliography including cca. One hundred references related to many aspects concerning as well the nomenclature, the classification and the chemical structures of the organophosphorus compounds as synthesis methods, purification and analysis of the main extracting agents used in uranium extraction

  13. Bidentate organophosphorus extractants: purification, properties and applications to removal of actinides from acidic waste solutions

    International Nuclear Information System (INIS)

    Schulz, W.W.; McIsaac, L.D.

    1977-05-01

    At both Hanford and Idaho, DHDECMP (dihexyl-N, N-diethylcarbamylmethylene phosphonate) continuous counter-current solvent extraction processes are being developed for removal of americium, plutonium, and, in some cases, other actinides from acidic wastes generated at these locations. Bench and, eventually, pilot and plant-scale testing and application of these processes have been substantially enhanced by the discovery of suitable chemical and physical methods of removing deleterious impurities from technical-grade DHDECMP. Flowsheet details, as well as various properties of purified DHDECMP extractants, are enumerated

  14. Extraction of cerium (III) by polymer gels swollen with bidentate organophosphorus compounds

    International Nuclear Information System (INIS)

    Takeshita, Kenji; Takashima, Yoichi; Matsumoto, Shiro; Yamanaka, Hiromitsu.

    1995-01-01

    The extraction of Ce (III) from aqueous solutions containing Al (NO 3 ) 3 was examined by using styrene-divinylbenzene copolymer (SDB) gels swollen with dihexyl-N, N-diethylcarbamoylmethylphosphonate (CMP), octyl(phenyl)-N, N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and an equimolar mixture of CMP and CMPO. The extraction constants (K ex ) for the gels with CMP and CMPO were evaluated. The distribution ratio of Ce (III) for the gel with an equimolar mixture of CMP and CMPO was described as K d = (K ex CMP [CMP] 3 + K ex CMPO [CMPO] 3 ) [NO 3 - ] 3 by using these extraction constants. The extraction rate was found to be controlled by diffusion of Ce-complex [Ce(NO 3 ) 3 (CMPO) 3 or Ce(NO 3 ) 3 (CMP) 3 ] through the gel. The diffusion coefficient (D s ) was inversely proportional to the viscosity of extractant (η) and represented by an expression similar to the Stokes-Einstein equation, D s η/T = constant. A decrease in the viscosity of extractant was effective for increasing the extraction rate. (author)

  15. Organophosphorus poisoning (acute).

    Science.gov (United States)

    Blain, Peter G

    2011-05-17

    Acetylcholinesterase inhibition by organophosphorus pesticides or organophosphate nerve agents can cause acute parasympathetic system dysfunction, muscle weakness, seizures, coma, and respiratory failure. Prognosis depends on the dose and relative toxicity of the specific compound, as well as pharmacokinetic factors. We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for acute organophosphorus poisoning? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). We found 62 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. In this systematic review we present information relating to the effectiveness and safety of the following interventions: activated charcoal (single or multiple doses), alpha(2) adrenergic receptor agonists, atropine, benzodiazepines, butyrylcholinesterase replacement therapy, cathartics, extracorporeal clearance, gastric lavage, glycopyrronium bromide (glycopyrrolate), ipecacuanha (ipecac), magnesium sulphate, milk or other home remedy immediately after ingestion, N-methyl-D-aspartate receptor antagonists, organophosphorus hydrolases, oximes, removing contaminated clothes and washing the poisoned person, and sodium bicarbonate.

  16. Neutral bidentate N-heterocyclic ligands - phase transfer reagents improving the kinetics of solvent extraction of Am(III) and Eu(III) ions with tetradentate 6,6'-bis-(diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine

    International Nuclear Information System (INIS)

    Narbutt, J.; Krejzler, J.

    2008-01-01

    Poor kinetics of solvent extraction of Am(III) and Eu(III) ions from 1 M HNO 3 with 6,6'-bis-(diethyl-1,2,4-triazin-3-yl)-2,2'-bipyridine (etBTBP) has been improved by adding an auxiliary bidentate N-heterocyclic ligand to the extraction system. Two such ligands were studied, derivatives of bis-triazine and pyridine-triazine, which alone poorly extract the metal ions, but together with etBTBP they act as phase transfer reagents, improving the extraction kinetics to a different degree. The ability to transfer the metal ions from aqueous to organic phase depends on lipophilicity and acid/base properties of these auxiliary ligands, as well as on the mode of shaking the two liquid phases - gentle or vigorous. (orig.)

  17. Chlorination of organophosphorus pesticides in natural waters

    Energy Technology Data Exchange (ETDEWEB)

    Acero, Juan L. [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)], E-mail: jlacero@unex.es; Benitez, F. Javier; Real, Francisco J.; Gonzalez, Manuel [Departamento de Ingenieria Quimica y Energetica, Universidad de Extremadura, 06071 Badajoz (Spain)

    2008-05-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 {sup o}C and pH 7 were determined to be 110.9, 0.004 and 191.6 M{sup -1} s{sup -1} for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L{sup -1} was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety.

  18. Chlorination of organophosphorus pesticides in natural waters

    International Nuclear Information System (INIS)

    Acero, Juan L.; Benitez, F. Javier; Real, Francisco J.; Gonzalez, Manuel

    2008-01-01

    Unknown second-order rate constants for the reactions of three organophosphorus pesticides (chlorpyrifos, chlorfenvinfos and diazinon) with chlorine were determined in the present study, and the influence of pH and temperature was established. It was found that an increase in the pH provides a negative effect on the pesticides degradation rates. Apparent second-order rate constants at 20 o C and pH 7 were determined to be 110.9, 0.004 and 191.6 M -1 s -1 for chlorpyrifos, chlorfenvinfos and diazinon, respectively. A higher reactivity of chlorine with the phosphorothioate group (chlorpyrifos and diazinon) than with the phosphate moiety (chlorfenvinfos) could explain these results. Intrinsic rate constant for the elementary reactions of chlorine species with chlorpyrifos and diazinon were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the pesticide is predominant at neutral pH. The elimination of these pesticides in surface waters was also investigated. A chlorine dose of 2.5 mg L -1 was enough to oxidize chlorpyrifos and diazinon almost completely, with a formation of trihalomethanes below the EU standard for drinking water. However, the removal of chlorfenvinfos was not appreciable. Therefore, chlorination is a feasible option for the removal of organophosphorus pesticides with phosphorothioate group during oxidation and disinfection processes, but not for the elimination of pesticides with phosphate moiety

  19. Bis(indenyl)zirconium(IV) complexes of monofunctional bidentate salicylidimines

    International Nuclear Information System (INIS)

    Sharma, A.K.; Khera, B.; Kaushik, N.K.

    1983-01-01

    A series of (C 9 H 7 ) 2 Zr(SB)Cl complexes where SB- is the anion of bidentate Schiff base derived from salicylaldehyde and 4-substitued anilines, viz. salicylidene-4-ansidine, salicylidene-4-phenetidine, salicylidene-4-chloroaniline, salicylidene-4-bromoaniline, salicylene-4-iodoaniline and salicylidene-4-nitroaniline, have been synthesized by the reaction of bis(indenyl)zirconium(IV) dichloride and Schiff base (SBH) in 1 : 1 molar ratio in refluxing THF in the presence of triethylamine. The new derivatives have been characterized on the basis of their elemental analyses, conductance measurements and spectral (IR, 1 H-NMR, UV-VIS) studies. (Author)

  20. Organophosphorus pesticide poisoning : cases and developments

    NARCIS (Netherlands)

    Aardema, H.; Ligtenberg, J. J. M.; Peters-Polman, O. M.; Tulleken, J. E.; Zijlstra, J. G.; Meertens, John H. J. M.

    Self-poisoning with organophosphate pesticides is a major health problem world-wide. Through the inhibition of acetylcholinesterase, organophosphorus poisoning is characterised by the clinical picture of acute cholinergic crisis. Other manifestations are the intermediate neurotoxic syndrome and

  1. Management of acute organophosphorus pesticide poisoning

    OpenAIRE

    Eddleston, Michael; Buckley, Nick A; Eyer, Peter; Dawson, Andrew H

    2008-01-01

    Summary Organophosphorus pesticide self-poisoning is an important clinical problem in rural regions of the developing world, and kills an estimated 200?000 people every year. Unintentional poisoning kills far fewer people but is a problem in places where highly toxic organophosphorus pesticides are available. Medical management is difficult, with case fatality generally more than 15%. We describe the limited evidence that can guide therapy and the factors that should be considered when design...

  2. of Several Organophosphorus Insecticide Metabolites

    Directory of Open Access Journals (Sweden)

    Russell L. Carr

    2015-01-01

    Full Text Available Paraoxonase (PON1 is a calcium dependent enzyme that is capable of hydrolyzing organophosphate anticholinesterases. PON1 activity is present in most mammals and previous research established that PON1 activity differs depending on the species. These studies mainly used the organophosphate substrate paraoxon, the active metabolite of the insecticide parathion. Using serum PON1 from different mammalian species, we compared the hydrolysis of paraoxon with the hydrolysis of the active metabolites (oxons of two additional organophosphorus insecticides, methyl parathion and chlorpyrifos. Paraoxon hydrolysis was greater than that of methyl paraoxon, but the level of activity between species displayed a similar pattern. Regardless of the species tested, the hydrolysis of chlorpyrifos-oxon was significantly greater than that of paraoxon or methyl paraoxon. These data indicate that chlorpyrifos-oxon is a better substrate for PON1 regardless of the species. The pattern of species differences in PON1 activity varied with the change in substrate to chlorpyrifos-oxon from paraoxon or methyl paraoxon. For example, the sex difference observed here and reported elsewhere in the literature for rat PON1 hydrolysis of paraoxon was not present when chlorpyrifos-oxon was the substrate.

  3. Lysophospholipase inhibition by organophosphorus toxicants

    International Nuclear Information System (INIS)

    Quistad, Gary B.; Casida, John E.

    2004-01-01

    Lysophospholipases (LysoPLAs) are a large family of enzymes for removing lysophospholipids from cell membranes. Potent inhibitors are needed to define the importance of LysoPLAs as targets for toxicants and potential therapeutics. This study considers organophosphorus (OP) inhibitors with emphasis on mouse brain total LysoPLA activity relative to the mipafox-sensitive neuropathy target esterase (NTE)-LysoPLA recently established as 17% of the total activity and important in the action of OP delayed toxicants. The most potent inhibitors of total LysoPLA in mouse brain are isopropyl dodecylphosphonofluoridate (also for LysoPLA of Vibrio bacteria), ethyl octylphosphonofluoridate (EOPF), and two alkyl-benzodioxaphosphorin 2-oxides (BDPOs)[(S)-octyl and dodecyl] (IC50 2-8 nM). OP inhibitors acting in vitro and in vivo differentiate a more sensitive portion but not a distinct NTE-LysoPLA compared with total LysoPLA activity. For 10 active inhibitors, NTE-LysoPLA is 17-fold more sensitive than total LysoPLA, but structure-activity comparisons give a good correlation (r 2 = 0.94) of IC50 values, suggesting active site structural similarity or identity. In mice 4 h after intraperitoneal treatment with discriminating doses, EOPF, tribufos (a plant defoliant), and dodecanesulfonyl fluoride inhibit 41-57% of the total brain LysoPLA and 85-99% of the NTE-LysoPLA activity. Total LysoPLA as well as NTE-LysoPLA is decreased in activity in Nte +/- -haploinsufficient mice compared to their Nte +/+ littermates. The lysolecithin level of spinal cord but not brain is elevated significantly following EOPF treatment (3 mg/kg), thereby focusing attention on localized rather than general alterations in lysophospholipid metabolism in OP-induced hyperactivity and toxicity

  4. Efficacious Oxime for Organophosphorus Poisoning: A Minireview

    African Journals Online (AJOL)

    Erah

    Abstract. Oximes are well known as acetylcholinesterase reactivators and are used in ... activity against structurally different kinds of organophosphorus ... serious threat with regard to occupational .... choose an oxime for unknown OPC exposure. Secondly, there is a lack of .... oximes, and hence cannot pass the blood.

  5. A retrospective analysis of acute organophosphorus poisoning ...

    African Journals Online (AJOL)

    A retrospective analysis of acute organophosphorus poisoning cases admitted to the tertiary care teaching hospital in South India. ... Young adult males were more commonly involved than females (M:F 2.5:1). The mean age of the patients was 28 years (range 2-72 years, SD ± 14.3 years). Mean time to receive treatment ...

  6. A retrospective analysis of acute organophosphorus poisoning ...

    African Journals Online (AJOL)

    organophosphorus (OP) poisoning cases in a tertiary care hospital. Materials and ... In a pre-structured proforma, data regarding age, sex, time elapsed after intake, circumstances of poisoning, duration of hospitalization ... responsible for majority of self-attempted deaths ... cleansed with water at the time of admission.

  7. Determination of selected organophosphorus pesticides using GC ...

    African Journals Online (AJOL)

    A reproducible analytical method utilising GC-MS is presented for the analysis of thirteen organophosphorus insecticides (OPs) often found in environmental aqueous samples. Extraction of filtered river and canal water (100 mL), fortified with the OPs, was conducted using solid-phase extraction and eluted with a variety of ...

  8. Efficacious Oxime for Organophosphorus Poisoning: A Minireview ...

    African Journals Online (AJOL)

    Oximes are well known as acetylcholinesterase reactivators and are used in organophosphorus poisoning to reactivate inhibited acetylcholinesterase. Therapeutically available oximes, namely, pralidoxime (2-PAM), obidoxime, trimedoxime and Hagedorn oxime (HI-6), have no broad-spectrum activity against structurally ...

  9. Influence of bidentate structure of an aryl phosphine oxide ligand on photophysical properties of its Eu~Ⅲ complex

    Institute of Scientific and Technical Information of China (English)

    许辉; 魏莹; 赵保敏; 黄维

    2010-01-01

    The bidentate phosphine oxide ligand 1,8-bis(diphenylphosphino) naphthalene oxide (NAPO) and its EuⅢ complex 1 Eu(TTA)3(NAPO) (TTA=2-thenoyltrifluoroacetonate) were chosen to study the effect of bidentate phosphine oxide ligand on the photophysical properties of the corresponding complex. The intramolecular energy transfer processes of 1 were studied. The investigation showed that with bidentate structure NAPO could suppress solvent-induced quenching by enforcing the ligand-ligand interaction and the rigidi...

  10. Synergistic Extraction of Copper from Nitrate Solutions Using β-Hydroxy-Naphthaldoxime and Organophosphorus Compounds into Carbon-Tetrachloride

    Science.gov (United States)

    Dey, Pulak; Basu, Sukalyan

    2011-12-01

    The extraction behavior of Cu(II) from an aqueous nitrate medium employing β-hydroxy-naphthaldoxime in carbon tetrachloride has been investigated in the presence of several organophosphorus donors like tri-octyl phosphine oxide, tri-butyl phosphine oxide, and tri-butyl phosphate at pH 1.5. The concentration of the metal was measured by atomic absorption spectrophotometry. Synergism was observed when neutral donor was added because of the formation of the adduct [Cu(L)2.(S)] in CCl4 (S denotes neutral donor). The equilibrium constants of the binary system using β-hydroxy-naphthaldoxime and the ternary system involving another addition of an organophosphorus compound were calculated from the extraction date obtained. Furthermore, the temperature dependence of the equilibrium constants was also investigated to evaluate standard enthalpy (Δ H°), entropy (Δ S°), and free energy (Δ G°) of the reactions proposed.

  11. Biochemical Markers for Exposure to Low Doses of Organophosphorus Insecticides

    National Research Council Canada - National Science Library

    Lockridge, Oksana

    2003-01-01

    Though acetylcholinesterase is the primary target of organophosphorus toxicants, our finding that acetylcholinesterase knockout mice are supersensitive to the lethal effects of VX, DFP, chlorpyrifos...

  12. Biochemical Markers for Exposure to Low Doses of Organophosphorus Insecticides

    National Research Council Canada - National Science Library

    Lockridge, Oksana

    2004-01-01

    Though acetylcholinesterase is the primary target of organophosphorus toxicants, our finding that acetylcholinesterase knockout mice are supersensitive to the lethal effects of VX, DFP, chlorpyrifos...

  13. Biochemical Markers for Exposure to Low Doses of Organophosphorus Insecticides

    National Research Council Canada - National Science Library

    Lockridge, Oksana

    2002-01-01

    Though acetyicholinesterase is the primary target of organophosphorus toxicants, our finding that acetyicholinesterase knockout mice are supersensitive to the lethal effects of VX, DFP, chlorpyrifos...

  14. Different approaches to acute organophosphorus poison treatment.

    Science.gov (United States)

    Nurulain, Syed Muhammad

    2012-07-01

    Organophosphorus compounds (OPCs) have a wide variety of applications and are a serious threat for self-poisoning, unintentional misuse, terrorist attack, occupational hazard and warfare attack. The present standard treatment has been reported to be unsatisfactory. Many novel approaches are being used and tested for acute organophosphorus (OP) poison treatment. The bioscavenger concept captured high attention among the scientific community during the last few decades. Other approaches like alkalinisation of blood plasma/serum and use of weak inhibitors against strong inhibitors, though it showed promising results, did not get such wide attention. The introduction of a novel broad-spectrum oxime has also been in focus. In this mini-review, an update of the overview of four different approaches has been discussed. The standard therapy that is atropine+oxime+benzodiazepine along with supportive measures will continue to be the best option with only the replacement of a single oxime to improve its broad-spectrum efficacy.

  15. Management of acute organophosphorus pesticide poisoning.

    Science.gov (United States)

    Eddleston, Michael; Buckley, Nick A; Eyer, Peter; Dawson, Andrew H

    2008-02-16

    Organophosphorus pesticide self-poisoning is an important clinical problem in rural regions of the developing world, and kills an estimated 200,000 people every year. Unintentional poisoning kills far fewer people but is a problem in places where highly toxic organophosphorus pesticides are available. Medical management is difficult, with case fatality generally more than 15%. We describe the limited evidence that can guide therapy and the factors that should be considered when designing further clinical studies. 50 years after first use, we still do not know how the core treatments--atropine, oximes, and diazepam--should best be given. Important constraints in the collection of useful data have included the late recognition of great variability in activity and action of the individual pesticides, and the care needed cholinesterase assays for results to be comparable between studies. However, consensus suggests that early resuscitation with atropine, oxygen, respiratory support, and fluids is needed to improve oxygen delivery to tissues. The role of oximes is not completely clear; they might benefit only patients poisoned by specific pesticides or patients with moderate poisoning. Small studies suggest benefit from new treatments such as magnesium sulphate, but much larger trials are needed. Gastric lavage could have a role but should only be undertaken once the patient is stable. Randomised controlled trials are underway in rural Asia to assess the effectiveness of these therapies. However, some organophosphorus pesticides might prove very difficult to treat with current therapies, such that bans on particular pesticides could be the only method to substantially reduce the case fatality after poisoning. Improved medical management of organophosphorus poisoning should result in a reduction in worldwide deaths from suicide.

  16. Analysis of organophosphorus pesticides using FT-NMR

    International Nuclear Information System (INIS)

    Miyata, Yoshihiko; Takahashi, Yoshikazu; Ando, Hiroaki

    1988-01-01

    A rapid and highly selective method of the identification of 23 kinds of organophosphorus pesticides was develop by using 31 P FT-NMR with 1 H complete decoupling method. Chemical shifts referenced by 85 % H 3 PO 4 were within -4 to 100 ppm, and there was no overlapping among the organophosphorus pesticides used in this experiment. (author)

  17. Plutonium and americium extraction studies with bifunctional organophosphorus extractants

    International Nuclear Information System (INIS)

    Navratil, J.D.

    1985-01-01

    Neutral bifunctional organophosphorus extractants, such as octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and dihexyl-N,N-diethylcarbamoylmethylphosphonate (CMP), are under study at the Rocky Flats Plant (RFP) to remove plutonium and americium from the 7M nitric acid waste. These compounds extract trivalent actinides from strong nitric acid, a property which distinguishes them from monofunctional organiphosphorus reagents. Furthermore, the reagents extract hydroytic plutonium (IV) polymer which is present in the acid waste stream. The compounds extract trivalent actinides with a 3:1 stoichiometry, whereas tetra- and hexavalent actinides extract with a stoichiometry of 2:1. Preliminary studies indicate that the extracted plutonium polymer complex contains one to two molecules of CMP per plutonium ion and the plutonium(IV) maintains a polymeric structure. Recent studies by Horwitz and co-workers conclude that the CMPO and CMP reagents behave as monodentate ligands. At RFP, three techniques are being tested for using CMP and CMPO to remove plutonium and americium from nitric acid waste streams. The different techniques are liquid-liquid extraction, extraction chromatography, and solid-supported liquid membranes. Recent tests of the last two techniques will be briefly described. In all the experiments, CMP was an 84% pure material from Bray Oil Co. and CMPO was 98% pure from M and T Chemicals

  18. A model for the calculation of lanthanide induced shifts of bidentate ligands - 1,3-diols

    International Nuclear Information System (INIS)

    Hofer, O.; Griengl, H.; Nowak, P.

    1978-01-01

    The NMR-LIS data of the four diastereomeric 2-(hydroxyphenylmethyl) cyclohexanols 1-4 are used to test two possible computational models for bidentate Eu(dpm)B 3 complexes. A model taking into account the presence of two equivalent coordinaton centers by averaging the corresponding dipolar fields of both centers proved to be superior to the simpler one assuming only one dipolar field with a fictive coordination center at a point equidistant between the two actual coordination sites. (author)

  19. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis

    Science.gov (United States)

    Johnson, H.; Kenley, R. A.; Rynard, C.; Golub, M. A.

    1985-01-01

    Quantitative structure-activity relationships were derived for acetyl- and butyrylcholinesterase inhibition by various organophosphorus esters. Bimolecular inhibition rate constants correlate well with hydrophobic substituent constants, and with the presence or absence of catonic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR'P(O)X, where R and R' are alkyl and/or alkoxy groups and X is fluorine, chlorine or a phenoxy group. For each subset with the same X, the CNDO-derived net atomic charge at the central phosphorus atom in the ester correlates well with the alkaline hydrolysis rate constant. For the whole set of esters with different X, two equations were derived that relate either charge and leaving group steric bulk, or orbital energy and bond order to the hydrogen hydrolysis rate constant.

  20. Treatment Strategies for the NMDA Component of Organophosphorus Convulsions

    National Research Council Canada - National Science Library

    Peterson, Steven

    2003-01-01

    ...) induced status epilepticus (SE) used here as a model of organophosphorus nerve agents. The nonbarbiturate anesthetic propofol was found to induce significant anticonvulsant and neuroprotectant effects in Li-pilo SE...

  1. [Decontamination of organophosphorus compounds: Towards new alternatives].

    Science.gov (United States)

    Poirier, L; Jacquet, P; Elias, M; Daudé, D; Chabrière, E

    2017-05-01

    Organophosphorus coumpounds (OP) are toxic chemicals mainly used for agricultural purpose such as insecticides and were also developed and used as warfare nerve agents. OP are inhibitors of acetylcholinesterase, a key enzyme involved in the regulation of the central nervous system. Chemical, physical and biological approaches have been considered to decontaminate OP. This review summarizes the current and emerging strategies that are investigated to tackle this issue with a special emphasis on enzymatic remediation methods. During the last decade, many studies have been dedicated to the development of biocatalysts for OP removal. Among these, recent reports have pointed out the promising enzyme SsoPox isolated from the archaea Sulfolobus solfataricus. Considering both its intrinsic stability and activity, this hyperthermostable enzyme is highly appealing for the decontamination of OP. Copyright © 2017 Académie Nationale de Pharmacie. All rights reserved.

  2. Latent ruthenium–indenylidene catalysts bearing a N-heterocyclic carbene and a bidentate picolinate ligand

    Directory of Open Access Journals (Sweden)

    Thibault E. Schmid

    2015-09-01

    Full Text Available A silver-free methodology was developed for the synthesis of unprecedented N-heterocyclic carbene ruthenium indenylidene complexes bearing a bidentate picolinate ligand. The highly stable (SIPr(picolinateRuCl(indenylidene complex 4a (SIPr = 1,3-bis(2-6-diisopropylphenylimidazolidin-2-ylidene demonstrated excellent latent behaviour in ring closing metathesis (RCM reaction and could be activated in the presence of a Brønsted acid. The versatility of the catalyst 4a was subsequently demonstrated in RCM, cross-metathesis (CM and enyne metathesis reactions.

  3. Fundamental study on the extraction of transuranium elements from high-level liquid waste

    International Nuclear Information System (INIS)

    Kubota, Masumitsu; Morita, Yasuji; Tochiyama, Osamu; Inoue, Yasushi.

    1988-01-01

    A great many extractants have been studied for the separation of transuranium elements. The present study deals with the survey and classification of the extractants appearing in literature, bearing in mind the relationship between the molecular structure of extractants and their extractability for the transuranium elements from the standpoint of their selective separation from high-level liquid waste (HLW) generated from fuel reprocessing. The extractants surveyed were classified into six groups; unidentate neutral organophosphorus compounds, bidentate neutral organophosphorus compounds, acidic organophosphorus compounds, amines and ammonium salts, N,N-disubstituted amides and the other compounds. These extractants are not always applicable to the separation of transuranium elements from HLW because of their limitations in extractability and radiation durability. Only a limited number of extractants belonging to the bidentate neutral organophosphorus compounds and the acidic organophosphorus compounds are considered to be suitable for the present purpose. (author)

  4. Optimization of Cholinesterase-Based Catalytic Bioscavengers Against Organophosphorus Agents.

    Science.gov (United States)

    Lushchekina, Sofya V; Schopfer, Lawrence M; Grigorenko, Bella L; Nemukhin, Alexander V; Varfolomeev, Sergei D; Lockridge, Oksana; Masson, Patrick

    2018-01-01

    Organophosphorus agents (OPs) are irreversible inhibitors of acetylcholinesterase (AChE). OP poisoning causes major cholinergic syndrome. Current medical counter-measures mitigate the acute effects but have limited action against OP-induced brain damage. Bioscavengers are appealing alternative therapeutic approach because they neutralize OPs in bloodstream before they reach physiological targets. First generation bioscavengers are stoichiometric bioscavengers. However, stoichiometric neutralization requires administration of huge doses of enzyme. Second generation bioscavengers are catalytic bioscavengers capable of detoxifying OPs with a turnover. High bimolecular rate constants ( k cat / K m > 10 6 M -1 min -1 ) are required, so that low enzyme doses can be administered. Cholinesterases (ChE) are attractive candidates because OPs are hemi-substrates. Moderate OP hydrolase (OPase) activity has been observed for certain natural ChEs and for G117H-based human BChE mutants made by site-directed mutagenesis. However, before mutated ChEs can become operational catalytic bioscavengers their dephosphylation rate constant must be increased by several orders of magnitude. New strategies for converting ChEs into fast OPase are based either on combinational approaches or on computer redesign of enzyme. The keystone for rational conversion of ChEs into OPases is to understand the reaction mechanisms with OPs. In the present work we propose that efficient OP hydrolysis can be achieved by re-designing the configuration of enzyme active center residues and by creating specific routes for attack of water molecules and proton transfer. Four directions for nucleophilic attack of water on phosphorus atom were defined. Changes must lead to a novel enzyme, wherein OP hydrolysis wins over competing aging reactions. Kinetic, crystallographic, and computational data have been accumulated that describe mechanisms of reactions involving ChEs. From these studies, it appears that introducing

  5. Optimization of Cholinesterase-Based Catalytic Bioscavengers Against Organophosphorus Agents

    Directory of Open Access Journals (Sweden)

    Sofya V. Lushchekina

    2018-03-01

    Full Text Available Organophosphorus agents (OPs are irreversible inhibitors of acetylcholinesterase (AChE. OP poisoning causes major cholinergic syndrome. Current medical counter-measures mitigate the acute effects but have limited action against OP-induced brain damage. Bioscavengers are appealing alternative therapeutic approach because they neutralize OPs in bloodstream before they reach physiological targets. First generation bioscavengers are stoichiometric bioscavengers. However, stoichiometric neutralization requires administration of huge doses of enzyme. Second generation bioscavengers are catalytic bioscavengers capable of detoxifying OPs with a turnover. High bimolecular rate constants (kcat/Km > 106 M−1min−1 are required, so that low enzyme doses can be administered. Cholinesterases (ChE are attractive candidates because OPs are hemi-substrates. Moderate OP hydrolase (OPase activity has been observed for certain natural ChEs and for G117H-based human BChE mutants made by site-directed mutagenesis. However, before mutated ChEs can become operational catalytic bioscavengers their dephosphylation rate constant must be increased by several orders of magnitude. New strategies for converting ChEs into fast OPase are based either on combinational approaches or on computer redesign of enzyme. The keystone for rational conversion of ChEs into OPases is to understand the reaction mechanisms with OPs. In the present work we propose that efficient OP hydrolysis can be achieved by re-designing the configuration of enzyme active center residues and by creating specific routes for attack of water molecules and proton transfer. Four directions for nucleophilic attack of water on phosphorus atom were defined. Changes must lead to a novel enzyme, wherein OP hydrolysis wins over competing aging reactions. Kinetic, crystallographic, and computational data have been accumulated that describe mechanisms of reactions involving ChEs. From these studies, it appears that

  6. Investigation on biomolecular interactions of nickel(II) complexes with monoanionic bidentate ligands

    Science.gov (United States)

    Jayamani, Arumugam; Sethupathi, Murugan; Ojwach, Stephen O.; Sengottuvelan, Nallathambi

    2018-01-01

    Reactions of monoanionic bidentate ligands 5-methylsalicylaldehyde (5-msal), 5-bromosalicylaldehyde (5-brsal), 5-nitrosalicylaldehyde (5-nsal) and 2-hydroxy-1-naphthaldehyde (2-hnap) with nickel perchlorate hexahydrate produced nickel(II) complexes 1-4, respectively. Single crystal X-ray analyses of complexes 1 and 2 confirmed bidentate mode of the ligands with O˄O coordination to give square planar geometry around nickel atoms. Complexes 1-4 showed one quasi-reversible redox peak at cathodic region (-0.67 to -0.80 V) and one redox peak at anodic region (+1.08 to +1.44 V) assignable to the Ni(II)/Ni(I) and Ni(II)/Ni(III) redox couples, respectively. The complexes exhibited good bovine serum albumin (BSA) binding abilities with a maximum binding constant of 1.96 × 105 M-1. The binding of complexes with calf thymus DNA (ctDNA) showed that the binding affinity is consistent with an increase in steric bulk of the ligands. The nuclease activity of the complexes showed efficient oxidative cleavage in the presence of hydrogen peroxide as an oxidizing agent. The complexes showed higher zone of inhibition when screened for antimicrobial activity against bacteria and human pathogenic fungi.

  7. Synthesis, Characterization and Biological Evaluation of Transition Metal Complexes Derived from N, S Bidentate Ligands

    Directory of Open Access Journals (Sweden)

    Enis Nadia Md Yusof

    2015-05-01

    Full Text Available Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC with 2-methoxybenzaldehyde (2MB and 3-methoxybenzaldehyde (3MB. The ligands were reacted separately with acetates of Cu(II, Ni(II and Zn(II yielding 1:2 (metal:ligand complexes. The metal complexes formed were expected to have a general formula of [M(NS2] where M = Cu2+, Ni2+, and Zn2+. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1 and S2M3MBH (2 were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7 and estrogen receptor-negative (MDA-MB-231 breast cancer cell lines. Only the Cu(II complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II complexes have a strong DNA binding affinity.

  8. Murai Reaction on Furfural Derivatives Enabled by Removable N,N'-Bidentate Directing Groups.

    Science.gov (United States)

    Pezzetta, Cristofer; Veiros, Luis F; Oble, Julie; Poli, Giovanni

    2017-06-22

    Furfural and related compounds are industrially relevant building blocks obtained from lignocellulosic biomass. To enhance the added value of these renewable resources, a Ru-catalyzed hydrofurylation of alkenes, involving a directed C-H activation at C3 of the furan ring, was developed. A thorough experimental study revealed that a bidentate amino-imine directing group enabled the desired coupling. Removal of the directing group occurred during the purification step, directly releasing the C3-functionalized furfurals. Development of the reaction as well as optimization and scope of the method were described. A mechanism was proposed on the basis of DFT calculations. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Successful treatment of Class II malocclusion with bidental protrusion using standard edgewise prescription

    Directory of Open Access Journals (Sweden)

    Mohd Ayaz

    2016-01-01

    Full Text Available This case report deals with the successful orthodontic treatment of a 14-year-old female patient having Class II malocclusion with bidental protrusion using standard edgewise prescription. She reported with forwardly placed upper front teeth and difficulty in closing lips. She had prognathic maxilla, retrognathic mandible, and full cusp Class II molar and canine relation bilaterally with overjet of 7 mm. She was in cervical vertebrae maturation indicator Stage IV. The case was treated by fixed extraction mechanotherapy. Interarch Class II mechanics was used to retract the upper incisor and to mesialize the lower molars. Simultaneously, Class I mechanics was used to upright lower incisors. Tip back bend, curve of Spee, and extra palatal root torque were incorporated in upper archwire to maintain molars in upright position and prevent extrusion and deepening of bite, respectively. There was satisfactory improvement in facial profile at the end of 24 months. After a follow-up of 6 months, occlusion was stable.

  10. Biodegradation of organophosphorus pesticides by soil bacteria

    Science.gov (United States)

    de Pasquale, C.; Fodale, R.; Lo Piccolo, L.; Palazzolo, E.; Alonzo, G.; Quatrini, P.

    2009-04-01

    A number of studies in the 1980s and 1990s showed that crop-protection products, applied to drained fields, could move downwards through the soil profile and to the groundwater. Organophosphorus insecticides (OPs) are used all over the world for crop protection, for other agricultural practices such as sheep dipping and, in aquaculture, for the control of sea lice. Ops besides showing a specific neurotoxicity and have also been related to various modern diseases, including Creutzfeldt-Jakob (CJD) and the Gulf War syndrome. Although OPs are less persistent than Organoclorine pesticides (OCs), they still constitute an environmental risks thus increasing the social concern about their levels in soils, surface waters, and ground waters. Degradation of OPs by microorganisms has been assessed for a few bacterial strains. In the present study the OPs degrading potential of indigenous soil microorganisms was investigated. Using enrichment cultures in which parathion was the only C and energy sources many bacterial strains were isolated from OPs contaminated and pristine agricultural soils characterized by different physico-chemical properties. More than 40 potential OPs degraders were isolated and grouped in operational taxonomic units (OTU) using analysis of polymorphism showed by the ribosomal internal transcribed spacer (ITS). Partial sequencing of 16S rRNA gene of representative isolates of each OTU revealed that most of them belong to Proteobacteria and Actinobacteria. All the analyzed soils showed the presence of putative OPs degraders: the highest diversity was found in organic cultivated soils, the lowest in chemically cultivated soils. Degradation of different OPs, characterized by different physical and chemical properties, was obtained by different selected representative strains using SPME GC-MS analysis on water and soil microcosms. The results showed that, after the incubation period, the amount of pesticide residues were in the range 20-80%. Some of the

  11. Study of Serum Amylase and Serum Cholinesterase in Organophosphorus Poisoning

    Directory of Open Access Journals (Sweden)

    Sharan Badiger

    2016-04-01

    Full Text Available Background: Poisoning due to organophosphorus compounds is most commonly seen. Earlier plasma cholinesterase level was used to assess the severity of poisoning. Presently serum amylase is being recommended as a better indicator of severity. Aims and Objectives: To study plasma cholinesterase and serum amylase levels in acute organophosphorus and to correlate serum amylase levels with clinical severity and outcome. Material and Methods: A total of 80 patients in the study admitted to a tertiary care centre within 24 hours with a history of organophosphorus poisoning were included in study. Estimation of plasma cholinesterase and serum rd amylase was done at the time of admission, and on 3 th day and on 5 day. Results: Occurrence of organophosphorus poisoning was more common among age group 21-30 years and among males (57.5%. They were 25 (31.2% farmers, 23 (28.8% st u d e n ts, a n d 2 2 ( 2 7 . 5% h o u s ewi v e s. Monocrotophos (45.0% was commonly used compound. Mean value of plasma cholinesterase and serum amylase at admission are 3693 U/L, and 185.4 U/L. There was significant inhibition of plasma cholinesterase and elevation of serum amylase at th admission with return to normal values on 5 day. Conclusion: Plasma cholinesterase inhibition 200 U/L has been associated with poor prognosis and proneness to respiratory failure.

  12. Acute organophosphorus compound poisoning in cattle: A case report

    African Journals Online (AJOL)

    A case of an acute organophosphorus compound, GOLDFLEECE poisoning involving 39 cattle at Abubakar Tafawa Balewa University, Bauchi is reported. The animals were overexposed to the compound following routine tick spray. Within 15 minutes after the spray of the compound, 26 animals were recumbent showing ...

  13. Acute organo-phosphorus pesticide poisoning in North Karnataka ...

    African Journals Online (AJOL)

    Background: Pesticide poisoning is an important cause of morbidity and mortality in India. Objectives: To assess the oxidative damage, hemoglobin level and leukocyte count in acute organophosphorus pesticide poisoning. Methods: Plasma cholinesterase was assessed as a toxicity marker. Oxidative damage was ...

  14. Synthesis and characterization of two new zinc(II) coordination polymers with bidentate flexible ligands: Formation of a 2D structure with (44.62)-sql topology

    Science.gov (United States)

    Lalegani, Arash; Khaledi Sardashti, Mohammad; Gajda, Roman; Woźniak, Krzysztof

    2017-12-01

    Zinc(II) coordination polymers [Zn(bip)2(NCS)2]n (1) and [Zn(μ-bbd)(N3)2]n (2) were synthesized by using the neutral flexible bidentate N-donor ligands 1,4-bis(3,5-dimethylpyrazolyl)butane (bbd) and 1,3-bis(imidazolyl)propane (bip), mono-anionic NCS- or N3-ligand and zinc(II) chloride salts. The results of the X-ray analyses demonstrate that in the structure of 1, the zinc(II) ion is located on an inversion center and exhibits an ZnN6 octahedral arrangement while, in the structure of 2, the zinc(II) ion adopts an ZnN4 tetrahedral geometry. In the polymer 1, the NCS groups are terminally N-bonded to the metal center and the each bip with anti-gauche conformation acts as bridging connecting four zinc(II) ions to form a two-dimensional network with a sql [point symbol (44.62)] topology while, in the polymer 1, the N3 groups are terminally bonded to the metal center and each bbd with anti-anti-anti conformation acts as bridging ligand connecting two zinc(II) ions to form a one-dimensional zig-zag chain. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction. Thermal analyses of polymers were also presented.

  15. Denaturation/Renaturation of Organophosphorus Acid Anhydrolase (OPAA) Using Guanidinium Hydrochloride and Urea

    National Research Council Canada - National Science Library

    Ong, K. K; Sun, Z; Cheng, T. C; Wei, Y; Yuan, J. M; Yin, R

    2004-01-01

    .... Using organophosphorus acid anhydrolase (OPAA) as the model protein, a guanidinium hydrochloride and urea denaturation/renaturation study was conducted and measured both optically and enzymatically...

  16. Organophosphorus pentavalent compounds: history, synthetic methods of preparation and application as insecticides and antitumor agents

    International Nuclear Information System (INIS)

    Santos, Viviane Martins Rebello dos; Donnici, Claudio Luis; DaCosta, Joao Batista Neves; Caixeiro, Janaina Marques Rodrigues

    2007-01-01

    This paper is a review of the history, synthesis and application of organophosphorus compounds, especially of those of pentavalent phosphorus, such as phosphoramidates, phosphorothioates, phosphonates and phosphonic acids with insecticide and anticancer activities. The organophosphorus compounds with agrochemical applications show great structural variety, They include not only insecticides, but also fungicides, herbicides, and others. The large variety of commercially available organophosphorus pesticides is remarkable. Even more interesting is the high efficiency of some organophosphorus compounds as anticancer agents such as cyclophosphamide and its derivatives. (author)

  17. Photochemistry of monodentate and bidentate carbonato complexes of rhodium (3). [applications to spacecraft fuel cells

    Science.gov (United States)

    Sheridan, P. S.

    1980-01-01

    A scheme for the photochemical fixation of water is proposed which involves a five-step reaction sequence; the first step involves the 2 electron reduction of a metal by a coordinated carbonate ligand, with corresponding oxidation of the carbonate to CO2 and O2. Ligand field photolysis of trans- (RH(en)2 H2O CO3) ClO4, and (Rh(en)2 CO3) CLO4 have been studied in the solid state and in aqueous solution at various pH values. Both salts are photoinert in the solid phase, but are quite photoreactive in aqueous solution. In solution, the monodentate ion undergoes efficient isomerization to a mixture of cis and trans - (Rh(en)2 H2O CO3)+, presumably with water exchange. A minor pH increase upon photolysis is evidence of inefficient carbonate (CO3 =) release, with formation of (Rh(en)2 (H2O)2)3+. In contrast, aqueous solutions of the bidentate carbonato complex undergo efficient pH decrease upon ligand field photolysis. Changes in the electronic spectrum (200-500 nm) and pH changes indicate that the desired redox is occurring. The pH increase is due to the aqueous behavior of CO2.

  18. Sol-gel niobia sorbent with a positively charged octadecyl ligand providing enhanced enrichment of nucleotides and organophosphorus pesticides in capillary microextraction for online HPLC analysis.

    Science.gov (United States)

    Kesani, Sheshanka; Malik, Abdul

    2018-04-01

    A niobia-based sol-gel organic-inorganic hybrid sorbent carrying a positively charged C 18 ligand (Nb 2 O 5 -C 18 (+ve)) was synthesized to achieve enhanced enrichment capability in capillary microextraction of organophosphorus compounds (which include organophosphorus pesticides and nucleotides) before their online analysis by high-performance liquid chromatography. The sorbent was designed to simultaneously provide three different types of molecular level interactions: electrostatic, Lewis acid-base, and van der Waals interactions. To understand relative contributions of various molecular level analyte-sorbent interactions in the extraction process, two other sol-gel niobia sorbents were also created: (a) a purely inorganic sol-gel niobia sorbent (Nb 2 O 5 ) and (b) an organic-inorganic hybrid sol-gel niobia sorbent carrying an electrically neutral-bonded octadecyl ligand (Nb 2 O 5 -C 18 ). The extraction efficiency of the created sol-gel niobia sorbent (Nb 2 O 5 -C 18 (+ve)) was compared with that of analogously designed and synthesized titania-based sol-gel sorbent (TiO 2 -C 18 (+ve)), taking into consideration that titania-based sorbents present state-of-the-art extraction media for organophosphorus compounds. In capillary microextraction with high-performance liquid chromatography analysis, Nb 2 O 5 -C 18 (+ve) had shown 40-50% higher specific extraction values (a measure of extraction efficiency) over that of TiO 2 -C 18 (+ve). Compared to TiO 2 -C 18 (+ve), Nb 2 O 5 -C 18 (+ve) also provided superior analyte desorption efficiency (96 vs. 90%) during the online release of the extracted organophosphorus pesticides from the sorbent coating in the capillary microextraction capillary to the chromatographic column using reversed-phase high-performance liquid chromatography mobile phase. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. A modular approach to neutral P,N-ligands: synthesis and coordination chemistry

    Directory of Open Access Journals (Sweden)

    Vladislav Vasilenko

    2016-04-01

    Full Text Available We report the modular synthesis of three different types of neutral κ2-P,N-ligands comprising an imine and a phosphine binding site. These ligands were reacted with rhodium, iridium and palladium metal precursors and the structures of the resulting complexes were elucidated by means of X-ray crystallography. We observed that subtle changes of the ligand backbone have a significant influence on the binding geometry und coordination properties of these bidentate P,N-donors.

  20. Neutral currents

    International Nuclear Information System (INIS)

    Paschos, E.A.

    1977-01-01

    It is stated that over the past few years considerable progress has been made in the field of weak interactions. The existence of neutral currents involving leptons and hadrons has been established and some of the questions concerning their detailed structure have been answered. This imposes constraints on the gauge theories and has eliminated large classes of models. New questions have also been raised, one of which concerns the conservation laws obeyed by neutral currents. The wide range of investigations is impressive and is expected to continue with new results from particle, nuclear, and atomic physics. Headings include - various aspects of a gauge theory (choice of group, the symmetry breaking scheme, representation assignments for fermion fields); space-time structure; isospin structure; leptonic neutral currents; and atomic experiments. (U.K.)

  1. Biodegradation and Utilization of Organophosphorus Pesticide Malathion by Cyanobacteria

    Directory of Open Access Journals (Sweden)

    Wael M. Ibrahim

    2014-01-01

    Full Text Available Three strains of filamentous Cyanobacteria were used to study their growth and utilization of organophosphorus pesticide malathion. A sharp decrease in the growth of the algal strains was observed by increasing the concentration of malathion. Amongst them Nostoc muscorum tolerated different concentrations and was recorded as the highest efficient strain for biodegradation (91% of this compound. Moreover, carbohydrate and protein content of their cells overtopped the other strains especially at higher concentrations. The algal strains were further subjected to grow under P-limitation in absence and presence of malathion. Although, the algal growth under P-limitation recorded a very poor level, a massive enhanced growth and phosphorous content of cells were obtained when the P-limited medium was amended with malathion. This study clarified that N. muscorum with its capability to utilize malathion as a sole phosphorous source is considered as an inexpensive and efficient biotechnology for remediation of organophosphorus pesticide from contaminated wastewater.

  2. Acute organophosphorus poisoning complicated by acute coronary syndrome.

    Science.gov (United States)

    Pankaj, Madhu; Krishna, Kavita

    2014-07-01

    We report a case of 30 year old alcoholic male admitted with vomiting, drowsiness, limb weakness and fasciculations after alleged history of consumption of 30 ml of chlorpyriphos insecticide. He had low serum cholinesterase levels. With standard treatment for organophosphorus poisoning (OPP), he improved gradually until day 5, when he developed neck and limb weakness and respiratory distress. This intermediate syndrome was treated with oximes, atropine and artificial ventilation. During treatment, his ECG showed fresh changes of ST elevation. High CPK & CPK-MB levels, septal hypokinesia on 2D echo suggested acute coronary syndrome. Coronary angiography was postponed due to his bedridden and obtunded status. The patient finally recovered fully by day 15 and was discharged. Acute coronary syndrome is a rare occurrence in OP poisoning. The present case thus emphasises the need for careful electrocardiographic and enzymatic monitoring of all patients of organophosphorus poisoning to prevent potential cardiac complication which can prove fatal.

  3. Neutral currents

    International Nuclear Information System (INIS)

    Aubert, B.

    1994-11-01

    The evidence for the existence of weak neutral current has been a very controverted topics in the early 1970's, as well as the muon did in the 1930's. The history is very rich considering the evolution of the experimental techniques in high energy particle physics. The history of the discovery and the study of weak neutral current is reviewed. Later the quest of the intermediate vector boson continues with the decision of the community to build a large proton antiproton collider. (K.A.). 14 refs., 1 fig

  4. Novel organophosphorus compounds; synthesis, spectroscopy and X-ray crystallography

    Czech Academy of Sciences Publication Activity Database

    Shariatinia, Z.; Sohrabi, M.; Yousefi, M.; Kovaľ, Tomáš; Dušek, Michal

    2012-01-01

    Roč. 11, č. 2 (2012), s. 125-133 ISSN 1024-1221 Grant - others:AV ČR(CZ) AP0701 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : organophosphorus compounds * NMR * X-ray crystallography * hydrogen bond Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.686, year: 2012

  5. The application of green chemistry methods in organophosphorus synthesis

    International Nuclear Information System (INIS)

    Odinets, Irina L; Matveeva, E V

    2012-01-01

    Data concerning the synthesis of organophosphorus compounds in ionic liquids, in water and under solvent-free conditions are considered and summarized. It is shown that this strategy, which complies with the definition of green chemistry, has advantages in terms of the rate of the process and the yields of target products as compared with syntheses in common organic solvents. The Wittig, Horner–Wadsworth–Emmons, Kabachnik–Fields, Arbuzov and Michaelis reactions are considered as examples. The bibliography includes 178 references.

  6. Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1

    International Nuclear Information System (INIS)

    Deng, Shuyan; Chen, Yao; Wang, Daosheng; Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong; Hua, Rimao; Tang, Xinyun; Li, Qing X.

    2015-01-01

    Highlights: • Stenotrophomonas sp. G1 was isolated from chlorpyrifos contaminated sludge. • Strain G1 is closest to Stenotrophomonas acidaminiphila. • Strain G1 can efficiently degrade 8 organophosphorus pesticides (OPs). • Intracellular methyl parathion hydrolase is responsible for the OP degradation. • Three factors were orthogonally optimized for degradation of methyl parathion. - Abstract: Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation

  7. Rapid biodegradation of organophosphorus pesticides by Stenotrophomonas sp. G1

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Shuyan; Chen, Yao [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Wang, Daosheng [School of Life Science, Anhui Agricultural University, Hefei 230036 (China); Shi, Taozhong; Wu, Xiangwei; Ma, Xin; Li, Xiangqiong [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Hua, Rimao, E-mail: rimaohua@ahau.edu.cn [Key Laboratory of Agri-food Safety of Anhui Province, Lab of Quality & Safety and Risk Assessment for Agro-products on Storage and Preservation (Hefei), Ministry of Agriculture, School of Resource and Environment, Anhui Agricultural University, Hefei 230036 (China); Tang, Xinyun [School of Life Science, Anhui Agricultural University, Hefei 230036 (China); Li, Qing X. [Department of Molecular Biosciences and Bioengineering, University of Hawaii at Manoa, 1955 East–West Road, Honolulu, HI 957822 (United States)

    2015-10-30

    Highlights: • Stenotrophomonas sp. G1 was isolated from chlorpyrifos contaminated sludge. • Strain G1 is closest to Stenotrophomonas acidaminiphila. • Strain G1 can efficiently degrade 8 organophosphorus pesticides (OPs). • Intracellular methyl parathion hydrolase is responsible for the OP degradation. • Three factors were orthogonally optimized for degradation of methyl parathion. - Abstract: Organophosphorus insecticides have been widely used, which are highly poisonous and cause serious concerns over food safety and environmental pollution. A bacterial strain being capable of degrading O,O-dialkyl phosphorothioate and O,O-dialkyl phosphate insecticides, designated as G1, was isolated from sludge collected at the drain outlet of a chlorpyrifos manufacture plant. Physiological and biochemical characteristics and 16S rDNA gene sequence analysis suggested that strain G1 belongs to the genus Stenotrophomonas. At an initial concentration of 50 mg/L, strain G1 degraded 100% of methyl parathion, methyl paraoxon, diazinon, and phoxim, 95% of parathion, 63% of chlorpyrifos, 38% of profenofos, and 34% of triazophos in 24 h. Orthogonal experiments showed that the optimum conditions were an inoculum volume of 20% (v/v), a substrate concentration of 50 mg/L, and an incubation temperature in 40 °C. p-Nitrophenol was detected as the metabolite of methyl parathion, for which intracellular methyl parathion hydrolase was responsible. Strain G1 can efficiently degrade eight organophosphorus pesticides (OPs) and is a very excellent candidate for applications in OP pollution remediation.

  8. Simultaneous inhibition of key growth pathways in melanoma cells and tumor regression by a designed bidentate constrained helical peptide.

    Science.gov (United States)

    Dhar, Amlanjyoti; Mallick, Shampa; Ghosh, Piya; Maiti, Atanu; Ahmed, Israr; Bhattacharya, Seemana; Mandal, Tapashi; Manna, Asit; Roy, Koushik; Singh, Sandeep; Nayak, Dipak Kumar; Wilder, Paul T; Markowitz, Joseph; Weber, David; Ghosh, Mrinal K; Chattopadhyay, Samit; Guha, Rajdeep; Konar, Aditya; Bandyopadhyay, Santu; Roy, Siddhartha

    2014-07-01

    Protein-protein interactions are part of a large number of signaling networks and potential targets for drug development. However, discovering molecules that can specifically inhibit such interactions is a major challenge. S100B, a calcium-regulated protein, plays a crucial role in the proliferation of melanoma cells through protein-protein interactions. In this article, we report the design and development of a bidentate conformationally constrained peptide against dimeric S100B based on a natural tight-binding peptide, TRTK-12. The helical conformation of the peptide was constrained by the substitution of α-amino isobutyric acid--an amino acid having high helical propensity--in positions which do not interact with S100B. A branched bidentate version of the peptide was bound to S100B tightly with a dissociation constant of 8 nM. When conjugated to a cell-penetrating peptide, it caused growth inhibition and rapid apoptosis in melanoma cells. The molecule exerts antiproliferative action through simultaneous inhibition of key growth pathways, including reactivation of wild-type p53 and inhibition of Akt and STAT3 phosphorylation. The apoptosis induced by the bidentate constrained helix is caused by direct migration of p53 to mitochondria. At moderate intravenous dose, the peptide completely inhibits melanoma growth in a mouse model without any significant observable toxicity. The specificity was shown by lack of ability of a double mutant peptide to cause tumor regression at the same dose level. The methodology described here for direct protein-protein interaction inhibition may be effective for rapid development of inhibitors against relatively weak protein-protein interactions for de novo drug development. © 2014 Wiley Periodicals, Inc.

  9. The brain imaging study of the organophosphorus pesticides poisoning

    International Nuclear Information System (INIS)

    Yang Yanmei; Liu Huaijun; Li Shuling; Wang Yongsheng; Huang Boyuan; Chi Cen; Shi Zhenyang; Cui Caixia; Zhou Lixia; Liu Runtian

    2004-01-01

    Objective: To summarize the CT and MR imaging findings in acute organophosphorus pesticides poisoning patients, and to improve the early diagnostic ability. Methods: The imaging of 34 patients of organophosphorus pesticides poisoning was analyzed, the poisons were all taken orally. The pesticides included methamidophos (12 cases), omethoate (15 cases), DDV (3 cases), and methylparathion (4 cases). According to the diagnosis and classification diagnosis criterion of acute organophosphorus pesticides poisoning, the patients were divided into two groups: mild or moderate grade group (24 cases) and severe grade group (10 cases). The relationship between the clinic grade and CT and MRI findings was studied. Results: in the severe grade group, 4 patients showed brain edema, presenting as sulcus and fissure flattened or disappeared, and ventricles and cisterns narrowed or closed 2-3 days after poisoning. In 3 patients 3 days to 3 months after poisoning, bilateral basal ganglion and cerebral cortex showed prolonged T 1 and T 2 signals, and high signal intensity was detected on FLAIR, and bilateral basal ganglion low density was revealed on CT. T 1 relaxation was shortened, T 2 WI and FLAIR imaging showed high signal intensity in 1 patient. The imaging of 1 patient 6 months after poisoning showed the cerebral sulcus, fissure and ventricle were enlarged. CT and MRI in the mild or moderate group were normal. By the Fisher's exact probabilities test, the imaging exhibition difference between the severe grade and mild or moderate grade patients was significant. Conclusion: The CT and MRI can reflect the brain injury after poisoning, and the imaging exhibitions were various. The imaging information can provide credible foundation for the therapy for lightening the brain edema and nourishing the brain cell

  10. Lanthanum(III) and praseodymium(III) complexes with bidentate and tetradentate Schiff base ligands containing indole ring

    International Nuclear Information System (INIS)

    Rai, Anita; Sengupta, Soumitra Kumar; Pandey, Om Prakash

    2000-01-01

    Complexes of lanthanum(III) and praseodymium(III) with Schiff bases, prepared from isatin with aniline, 4-chloroaniline, 2- bromoaniline, 2-nitroaniline (Hl), ethylenediamine, o- phenylenediamine and 4-methyl-o-phenylenediamine (H 2 L') have been synthesised and their physico-chemical properties investigated using elemental analysis, molar conductivities, magnetic susceptibility measurements and spectral (visible, infrared and 1 H NMR) data. The Schiff bases HL bind in a bidentate manner while schiff bases H 2 L' bind in a tetradentate manner. The probable structures of the complexes are proposed. (author)

  11. Multifunctional organophosphorus extractants: a status report on development and applications

    International Nuclear Information System (INIS)

    Schulz, W.W.; Horwitz, E.P.

    1988-01-01

    Up-to-date state of the development of science and technology of multifunctional organophosphorus extractants is considered. The detailed classification of these extractants is presented. They attracted pasticular interest because of affinity of some bifunctional phosphonates, phosphine oxides, carbamoylalkylphosphonates to trivalent Am, tetravalent and hexavalent actinides, trivalent lanthanides in strong mineral acids, and because of ability of some alkylpyrophosphoric acids to extract effectively U(4) from concentrated solutions of phosphoric acid. Application of these extractants for analytic purposes and in the field of nuclear technology is considered

  12. [Meta-analysis of association between organophosphorus pesticides and aplastic anemia].

    Science.gov (United States)

    Zhang, Ji; Yang, Tubao

    2015-09-01

    To evaluate the association between organophosphorus pesticides and aplastic anemia, and provide scientific evidence for the primary prevention of aplastic anemia. The published papers of case control studies on the association between organophosphorus pesticides and aplastic anemia from January 1990 to August 2014 were collected from Chinese BioMedical Literature Base (CBM), Chinese National Knowledge Infrastructure (CNKI), PubMed and EMBASE. The papers which met the inclusion criteria were evaluated. The pooled odds ratios (OR) and 95% confidence interval (CI) of organophosphorus pesticides were calculated with software Review Manager 5.0. Subgroup analysis were conducted for different population and different usage of organophosphorus pesticides. A total of 9 papers were selected, involving 5 833 subjects (1 404 cases and 4 429 controls). The results showed that organophosphorus pesticides could increase the risk of aplastic anemia (OR=1.97, 95% CI: 1.60-2.44) . Subgroup analysis showed that Asian (OR=2.01, 95% CI: 1.52-2.66) had higher risk of aplastic anemia than American or European (OR=1.93, 95% CI: 1.39-2.67) . Using pure organophosphorus pesticides (OR=2.15, 95% CI: 1.60-2.88) was more prone to cause aplastic anemia than using the mixture of organophosphorus pesticides (OR=1.82, 95% CI: 1.34-2.47). The analysis indicated that organophosphorus pesticides might be a risk factor for aplastic anemia. Reducing organophosphorus pesticides exposure in daily life and industrial or agricultural production could prevent the incidence of aplastic anemia.

  13. Acute myocardial infarction: Can it be a complication of acute organophosphorus compound poisoning?

    Directory of Open Access Journals (Sweden)

    P Joshi

    2013-01-01

    Full Text Available Organophosphorus compounds are used as pesticides and represent a common cause of poisoning in developing countries including India due to their widespread availability and use. Toxicity due to these agents can affect many organs including heart. Here, we report a case of acute organophosphorus poisoning (parathion, followed by acute myocardial infarction; documented by clinical features, electrocardiographic changes, and elevated cardiac enzymes. Myocardial infarction has been rarely reported with organophosphorus compounds exposure, thus awareness of this complication can reduce morbidity and mortality.

  14. Levels of organophosphorus pesticides in medicinal plants commonly consumed in Iran

    Directory of Open Access Journals (Sweden)

    Sarkhail Parisa

    2012-08-01

    Full Text Available Abstract The frequent occurrence of pesticide residues in herbal materials was indicated by previous studies. In this study, the concentration of some of the organophosphorus pesticides including parathion, malathion, diazinon and pirimiphos methyl in different kinds of medicinal plants were determined. The samples were collected randomly from ten local markets of different areas of Iran. At the detection limit of 0.5 ng g-1, parathion and pirimiphos methyl were not detected in any of the samples. Some amounts of malathion and diazinon were found in Zataria, Matricaria chamomile, Spearmint and Cumin Seed samples while, the concentrations of target organophosphorus pesticides in Borage samples were below the detection limits of the methods which could be a result of intensive transformation of organophosphorus pesticides by Borage. In addition the organophosphorus pesticides were detected in all of the samples below the maximum residue levels (MRLs proposed by the international organizations.

  15. UPTAKE AND PHYTOTRANSFORMATION OF ORGANOPHOSPHORUS PESTICIDES BY AXENICALLY CULTIVATED AQUATIC PLANTS

    Science.gov (United States)

    The uptake and phytotransformation of organophosphorus (OP) pesticides (malathion, demeton-S-methyl, and crufomate) was investigated in vitro using the axenically aquatic cultivated plants parrot feather (Myriophyllum aquaticum), duckweed (Spirodela oligorrhiza L.), and elodea (E...

  16. Surface Chemistry of Enzymes for Detection and Decontamination of Organophosphorus Compounds

    National Research Council Canada - National Science Library

    Leblanc, Roger

    2003-01-01

    ...), organophosphorus acid hydrolase (OPH), and covalent bonding of the enzyme onto the substrate. Results are encouraging and the studied enzymes form stable monolayers at the interface and can be transferred on to the solid substrate...

  17. Modulation of Immune Response by Organophosphorus Pesticides: Fishes as a Potential Model in Immunotoxicology

    Science.gov (United States)

    Díaz-Resendiz, K. J. G.; Toledo-Ibarra, G. A.; Girón-Pérez, M. I.

    2015-01-01

    Immune response is modulated by different substances that are present in the environment. Nevertheless, some of these may cause an immunotoxic effect. In this paper, the effect of organophosphorus pesticides (frequent substances spilled in aquatic ecosystems) on the immune system of fishes and in immunotoxicology is reviewed. Furthermore, some cellular and molecular mechanisms that might be involved in immunoregulation mechanisms of organophosphorus pesticides are discussed. PMID:25973431

  18. Modulation of Immune Response by Organophosphorus Pesticides: Fishes as a Potential Model in Immunotoxicology

    Directory of Open Access Journals (Sweden)

    K. J. G. Díaz-Resendiz

    2015-01-01

    Full Text Available Immune response is modulated by different substances that are present in the environment. Nevertheless, some of these may cause an immunotoxic effect. In this paper, the effect of organophosphorus pesticides (frequent substances spilled in aquatic ecosystems on the immune system of fishes and in immunotoxicology is reviewed. Furthermore, some cellular and molecular mechanisms that might be involved in immunoregulation mechanisms of organophosphorus pesticides are discussed.

  19. Organophosphorus flame retardants and plasticizers in the atmosphere of the North Sea

    International Nuclear Information System (INIS)

    Moeller, Axel; Xie Zhiyong; Caba, Armando; Sturm, Renate; Ebinghaus, Ralf

    2011-01-01

    Air samples collected in the German part of the North Sea from March to July 2010 were investigated for organophosphorus compounds (OPs) being applied as flame retardants and plasticizers. The Σ 8 OPs concentration ranged from 110 to 1400 pg m -3 while tris(2-chloroisopropyl) phosphate (TCPP) dominated all samples with individual concentrations up to 1200 pg m -3 . The highest concentrations were observed in continental air masses showing the high influence of industrialized regions including production sites on atmospheric emissions and concentrations. The occurrence of OPs even in oceanic/Arctic air masses shows that OPs can undergo long-range atmospheric transport. Dry particle-bound deposition fluxes from 9 to 240 ng m -2 d -1 for Σ 8 OPs were estimated leading to a minimum annual flux of 710 ± 580 kg y -1 OPs into the German North Sea. This study presents the first occurrence of OPs in the marine atmosphere together with important information on their long-range transport potential. - Highlights: → Organophosphorus flame retardants are detected for the first time in the marine atmosphere. → Organophosphorus compounds can undergo medium to long-range atmospheric transport. → Western Europe emits organophosphorus compounds to the marine atmosphere. → Marine air levels of organophosphorus flame retardants range up to 1 ng/m 3 . - Organophosphorus flame retardants, in particular tris(2-chloroisopropyl) phosphate, are emitted into the North Sea atmosphere by Western European countries.

  20. Tetra- and hexavalent uranium forms bidentate-mononuclear complexes with particulate organic matter in a naturally uranium-enriched peatland

    DEFF Research Database (Denmark)

    Mikutta, Christian; Langner, Peggy; Bargar, John R.

    2016-01-01

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work...... of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ∼3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. Our data indicates that U(IV/VI) complexation by natural organic matter prevents...... the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI)....

  1. Determination of organophosphorus pesticide residues in tomatoes by gas chromatography

    International Nuclear Information System (INIS)

    Souissi, Sihem

    2010-01-01

    Chloropyriphos and malathion are two organophosphorus pesticides from many others pesticides widely used by famers in agriculture .Because of their bad effect on human health, officials standards are set by the international organisations and communities to ensure safer food for consumer .In the same way, scientists over the world are working hard to develop new detection techniques responding to the international requirements. In this study, an ' IAEA-ethylacetate method ', an adaptation of the popular QuEChERS multi residue method, was optimized to analyse chloropyriphos and Malathion residues in tomatoes .Ethyl-Acetate was used as an extraction solvent the PSA was kept for the clean up procedure. GC-NPD is used for samples analysis .The method optimized is specifique, selective with a recovery averaged more than 70 pour cent. A complete validation of the method is necessary to be used for routine analysis.

  2. Fluorescent Chemosensors for Toxic Organophosphorus Pesticides: A Review

    Directory of Open Access Journals (Sweden)

    Kenneth Fletcher

    2010-07-01

    Full Text Available Many organophosphorus (OP based compounds are highly toxic and powerful inhibitors of cholinesterases that generate serious environmental and human health concerns. Organothiophosphates with a thiophosphoryl (P=S functional group constitute a broad class of these widely used pesticides. They are related to the more reactive phosphoryl (P=O organophosphates, which include very lethal nerve agents and chemical warfare agents, such as, VX, Soman and Sarin. Unfortunately, widespread and frequent commercial use of OP-based compounds in agricultural lands has resulted in their presence as residues in crops, livestock, and poultry products and also led to their migration into aquifers. Thus, the design of new sensors with improved analyte selectivity and sensitivity is of paramount importance in this area. Herein, we review recent advances in the development of fluorescent chemosensors for toxic OP pesticides and related compounds. We also discuss challenges and progress towards the design of future chemosensors with dual modes for signal transduction.

  3. Clinical emergency treatment of 68 critical patients with severe organophosphorus poisoning and prognosis analysis after rescue.

    Science.gov (United States)

    Dong, Hui; Weng, Yi-Bing; Zhen, Gen-Shen; Li, Feng-Jie; Jin, Ai-Chun; Liu, Jie

    2017-06-01

    This study reports the clinical emergency treatment of 68 critical patients with severe organophosphorus poisoning, and analyzes the prognosis after rescue.The general data of 68 patients with severe organophosphorus poisoning treated in our hospital were retrospectively analyzed. These patients were divided into 2 groups: treatment group, and control group. Patients in the control group received routine emergency treatment, while patients in the treatment group additionally received hemoperfusion plus hemodialysis on the basis of routine emergency treatment. The curative effects in these 2 groups and the prognosis after rescue were compared.Compared with the control group, atropinization time, recovery time of cholinesterase activity, recovery time of consciousness, extubation time, and length of hospital stay were shorter (P poisoning rebound rate was significantly lower (P treatment group.Hemoperfusion and hemodialysis on the basis of routine emergency treatment for critical patients with organophosphorus poisoning can improve rescue outcomes and improve the prognosis of patients, which should be popularized.

  4. Organophosphorus reagents in actinide separations: Unique tools for production, cleanup and disposal

    International Nuclear Information System (INIS)

    Nash, K. L.

    2000-01-01

    Interactions of actinide ions with phosphate and organophosphorus reagents have figured prominently in nuclear science and technology, particularly in the hydrometallurgical processing of irradiated nuclear fuel. Actinide interactions with phosphorus-containing species impact all aspects from the stability of naturally occurring actinides in phosphate mineral phases through the application of the bismuth phosphate and PUREX processes for large-scale production of transuranic elements to the development of analytical separation and environment restoration processes based on new organophosphorus reagents. In this report, an overview of the unique role of organophosphorus compounds in actinide production, disposal, and environment restoration is presented. The broad utility of these reagents and their unique chemical properties is emphasized

  5. Structure–efficiency relationships of cyclodextrin scavengers in the hydrolytic degradation of organophosphorus compounds

    Directory of Open Access Journals (Sweden)

    Sophie Letort

    2017-03-01

    Full Text Available New derivatives of cyclodextrins were prepared in order to determine the relative importance of the structural key elements involved in the degradation of organophosphorus nerve agents. To avoid a competitive inclusion between the organophosphorus substrate and the iodosobenzoate group, responsible for its degradation, the latter group had to be covalently bound to the cyclodextrin scaffold. Although the presence of the α nucleophile iodosobenzoate was a determinant in the hydrolysis process, an imidazole group was added to get a synergistic effect towards the degradation of the agents. The degradation efficiency was found to be dependent on the relative position of the heterocycle towards the reactive group as well as on the nature of the organophosphorus derivative.

  6. A systems-level approach for investigating organophosphorus pesticide toxicity.

    Science.gov (United States)

    Zhu, Jingbo; Wang, Jing; Ding, Yan; Liu, Baoyue; Xiao, Wei

    2018-03-01

    The full understanding of the single and joint toxicity of a variety of organophosphorus (OP) pesticides is still unavailable, because of the extreme complex mechanism of action. This study established a systems-level approach based on systems toxicology to investigate OP pesticide toxicity by incorporating ADME/T properties, protein prediction, and network and pathway analysis. The results showed that most OP pesticides are highly toxic according to the ADME/T parameters, and can interact with significant receptor proteins to cooperatively lead to various diseases by the established OP pesticide -protein and protein-disease networks. Furthermore, the studies that multiple OP pesticides potentially act on the same receptor proteins and/or the functionally diverse proteins explained that multiple OP pesticides could mutually enhance toxicological synergy or additive on a molecular/systematic level. To the end, the integrated pathways revealed the mechanism of toxicity of the interaction of OP pesticides and elucidated the pathogenesis induced by OP pesticides. This study demonstrates a systems-level approach for investigating OP pesticide toxicity that can be further applied to risk assessments of various toxins, which is of significant interest to food security and environmental protection. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Detection of Organophosphorus Pesticides with Colorimetry and Computer Image Analysis.

    Science.gov (United States)

    Li, Yanjie; Hou, Changjun; Lei, Jincan; Deng, Bo; Huang, Jing; Yang, Mei

    2016-01-01

    Organophosphorus pesticides (OPs) represent a very important class of pesticides that are widely used in agriculture because of their relatively high-performance and moderate environmental persistence, hence the sensitive and specific detection of OPs is highly significant. Based on the inhibitory effect of acetylcholinesterase (AChE) induced by inhibitors, including OPs and carbamates, a colorimetric analysis was used for detection of OPs with computer image analysis of color density in CMYK (cyan, magenta, yellow and black) color space and non-linear modeling. The results showed that there was a gradually weakened trend of yellow intensity with the increase of the concentration of dichlorvos. The quantitative analysis of dichlorvos was achieved by Artificial Neural Network (ANN) modeling, and the results showed that the established model had a good predictive ability between training sets and predictive sets. Real cabbage samples containing dichlorvos were detected by colorimetry and gas chromatography (GC), respectively. The results showed that there was no significant difference between colorimetry and GC (P > 0.05). The experiments of accuracy, precision and repeatability revealed good performance for detection of OPs. AChE can also be inhibited by carbamates, and therefore this method has potential applications in real samples for OPs and carbamates because of high selectivity and sensitivity.

  8. Neurotoxicity in Preclinical Models of Occupational Exposure to Organophosphorus Compounds

    Science.gov (United States)

    Voorhees, Jaymie R.; Rohlman, Diane S.; Lein, Pamela J.; Pieper, Andrew A.

    2017-01-01

    Organophosphorus (OPs) compounds are widely used as insecticides, plasticizers, and fuel additives. These compounds potently inhibit acetylcholinesterase (AChE), the enzyme that inactivates acetylcholine at neuronal synapses, and acute exposure to high OP levels can cause cholinergic crisis in humans and animals. Evidence further suggests that repeated exposure to lower OP levels insufficient to cause cholinergic crisis, frequently encountered in the occupational setting, also pose serious risks to people. For example, multiple epidemiological studies have identified associations between occupational OP exposure and neurodegenerative disease, psychiatric illness, and sensorimotor deficits. Rigorous scientific investigation of the basic science mechanisms underlying these epidemiological findings requires valid preclinical models in which tightly-regulated exposure paradigms can be correlated with neurotoxicity. Here, we review the experimental models of occupational OP exposure currently used in the field. We found that animal studies simulating occupational OP exposures do indeed show evidence of neurotoxicity, and that utilization of these models is helping illuminate the mechanisms underlying OP-induced neurological sequelae. Still, further work is necessary to evaluate exposure levels, protection methods, and treatment strategies, which taken together could serve to modify guidelines for improving workplace conditions globally. PMID:28149268

  9. Preparation of Electrochemical Biosensor for Detection of Organophosphorus Pesticides

    Directory of Open Access Journals (Sweden)

    Ashish Gothwal

    2014-01-01

    Full Text Available Polyvinyl chloride (PVC can be used to develop reaction beaker which acts as electrochemical cell for the measurement of OP pesticides. Being chemically inert, corrosion resistant, and easy in molding to various shapes and size, PVC can be used for the immobilization of enzyme. Organophosphorus hydrolase was immobilized covalently onto the chemically activated inner surface of PVC beaker by using glutaraldehyde as a coupling agent. The carbon nanotubes paste working electrode was constructed for amperometric measurement at a potential of +0.8 V. The biosensor showed optimum response at pH 8.0 with incubation temperature of 40°C. Km and Imax for substrate (methyl parathion were 322.58 µM and 1.1 µA, respectively. Evaluation study showed a correlation of 0.985, which was in agreement with the standard method. The OPH biosensor lost 50% of its initial activity after its regular use for 25 times over a period of 50 days when stored in 0.1 M sodium phosphate buffer, pH 8.0 at 4°C. No interference was observed by interfering species.

  10. ANALYSIS OF ORGANOPHOSPHORUS POISONING, AT TERTIARY CARE HOSPITAL: A REPORT

    Directory of Open Access Journals (Sweden)

    Shakuntala

    2015-01-01

    Full Text Available BACKGROUND: Organophosphorus (OP compounds are the most common suicidal poison in developing countries and mortality continues to be high. The present study was aimed to know the pattern and outcome of the OP poisoning. METHODOLOGY: A record based retrospective study from January 2013 - December 2013 was Conducted in a tertiary care hospital and data regarding age, gender, domicile, type of poison, manner of poisoning, seasonal trends, marital status, motive behind poisoning , socio - economic status and outcome was collected in a pre - structured Performa. All data were documented, analyzed and interpreted as per the laid down protocol. RESULTS : out of total 1575 cases of OP compound poisoning, 71.73% (1130 were male, 28.27% (445 were female, 34.6% were in the age group 21 - 30 years, 70.95% were of low socio - economic status, Occupation wise agricultural workers were on top of the list (70.07%, The commonest (93.78% motive behind poisoning was suicidal in both males and females, Financial problem was one of the commonest (51.22% reasons of poisoning. The mortality rate in our study was 13.47%. CONCLUSION : Y oung and adult males of Low socio - economic class, rural, both literate and illiterate agriculturists commonly abuse this substance to commit suicide

  11. Synthesis, Thermal, Electrical and Catalytic Studies of Some Transition Metal Polychelates of Bis-bidentate Schiff Base

    Institute of Scientific and Technical Information of China (English)

    BANSOD Ashish; ASWAR Anand

    2007-01-01

    Polychelates of Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ), Ni(Ⅱ),Cu(Ⅱ),Zn(Ⅱ) and Cd(Ⅱ) with the bis salen-type ligand derivedfrom 4,4'-bis[(salicylaldehyde-5)azo]biphenyl and 1,4-diaminobutane have been synthesized.All the polychelates have been characterized by elemental analysis,magnetic susceptibility measurements,IR,electronic spectra and thermogravimetric studies.All the complexes isolated in solid state are dark coloured and insoluble in water and common organic solvents.The ligand behaves as a bis-bidentate molecule coordinating through the phenolic oxygen and azomethine nitrogen atoms.The thermal decomposition of these metal complexes was investigated by thermogravimetric analysis and data have been analyzed for kinetic parameters using Broido equation.The solid-state electrical conductivity of the ligand and its polychelates in the form of compressed pellet was studied in the temperature range from 313 to 413 K.All the polychelates were found to show semiconducting nature.The Mn(Ⅱ),Fe(Ⅱ),Co(Ⅱ) and Ni(Ⅱ) polychelates have been assessed for the catalytic epoxidation of styrene.

  12. Differences between organophosphorus insecticides in human self-poisoning: a prospective cohort study.

    Science.gov (United States)

    Eddleston, Michael; Eyer, Peter; Worek, Franz; Mohamed, Fahim; Senarathna, Lalith; von Meyer, Ludwig; Juszczak, Edmund; Hittarage, Ariyasena; Azhar, Shifa; Dissanayake, Wasantha; Sheriff, M H Rezvi; Szinicz, Ladislaus; Dawson, Andrew H; Buckley, Nick A

    Although more than 100 organophosphorus insecticides exist, organophosphorus poisoning is usually regarded as a single entity, distinguished only by the compound's lethal dose in animals. We aimed to determine whether the three most common organophosphorus insecticides used for self-poisoning in Sri Lanka differ in the clinical features and severity of poisoning they cause. We prospectively studied 802 patients with chlorpyrifos, dimethoate, or fenthion self-poisoning admitted to three hospitals. Blood cholinesterase activity and insecticide concentration were measured to determine the compound and the patients' response to insecticide and therapy. We recorded clinical outcomes for each patient. Compared with chlorpyrifos (35 of 439, 8.0%), the proportion dying was significantly higher with dimethoate (61 of 264, 23.1%, odds ratio [OR] 3.5, 95% CI 2.2-5.4) or fenthion (16 of 99, 16.2%, OR 2.2, 1.2-4.2), as was the proportion requiring endotracheal intubation (66 of 439 for chlorpyrifos, 15.0%; 93 of 264 for dimethoate, 35.2%, OR 3.1, 2.1-4.4; 31 of 99 for fenthion, 31.3%, 2.6, 1.6-4.2). Dimethoate-poisoned patients died sooner than those ingesting other pesticides and often from hypotensive shock. Fenthion poisoning initially caused few symptoms but many patients subsequently required intubation. Acetylcholinesterase inhibited by fenthion or dimethoate responded poorly to pralidoxime treatment compared with chlorpyrifos-inhibited acetylcholinesterase. Organophosphorus insecticide poisoning is not a single entity, with substantial variability in clinical course, response to oximes, and outcome. Animal toxicity does not predict human toxicity since, although chlorpyrifos is generally the most toxic in rats, it is least toxic in people. Each organophosphorus insecticide should be considered as an individual poison and, consequently, patients might benefit from management protocols developed for particular organophosphorus insecticides.

  13. Synthesis and characterization of zinc(II), cadmium(II) and mercury(II) complexes with bis(bidentate) Schiff bases

    International Nuclear Information System (INIS)

    Das, Mrinal Kanti; Ghosh, Shyamali

    1998-01-01

    A few Zn(II), Cd(II) and Hg(II) complexes of the bis(bidentate) Schiff bases derived from p-phenylenediamine and salicylaldehyde (H 2 Salpphen), and o-phenylenediamine and o-vanillin (H 2 Vanophen), of the type MCl 2 .H 2 L(H 2 L = H 2 Salpphen or H 2 Vanophen) have been synthesised. The complexes have been characterized by elemental analysis, infrared, 1 H and 13 C NMR and mass spectra. (author)

  14. Neutral Buoyancy Laboratory (NBL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Neutral Buoyancy Laboratory (NBL) is an astronaut training facility and neutral buoyancy pool operated by NASA and located at the Sonny Carter Training Facility,...

  15. Organophosphorus flame retardants – Toxicity and influence on human health

    Directory of Open Access Journals (Sweden)

    Elżbieta Bruchajzer

    2015-06-01

    Full Text Available Organophosphorus flame retardants (flame retardants, FRs have been used for several decades in many industries, including the production of dyes, varnishes, adhesives, synthetic resins, polyvinyl chloride, hydraulic fluids, plastics and textiles. Their importance in recent times has increased due to i.a., significantly reduced use of polybrominated diphenyl ethers (PBDEs – persistent organic pollutants, dangerous for the environment. The aim of this study was to review the available literature data concerning phosphorous FRs primarily for neurotoxic, fertility, reproductive and carcinogenic effects. The analysis concerned the following most commonly used substances: tris(2-ethylhexylphosphate (TEHP, tris(2-butoxyethylphosphate (TBEP, triphenyl phosphate (TPP, tris(2-chloroethylphosphate (TCEP, tetrakis(hydroxymethyl-phosphonium chloride (THPC, tributyl phosphate (TBP, tricresyl phosphate (TCP, tris(2-chloroisopropylphosphate (TCPP, tris(1,3-dichloroisopropylphosphate (TDCP and tetrakis(hydroxymethyl phosphonium sulphate (THPS. In animal studies neurotoxic effects were found after exposure to TBEP, THPC, TBP and TCP, while in humans they were observed only after exposure to TCP. TCEP, THPS, TBP, TCP and TDCP caused disorders in fertility and/or fetal development of animals. Adverse effects on reproduction in humans may be caused by TPP, TCP, and TDCP. In laboratory animals the development of tumors was observed after high doses of TEHP, TCEP, TBP and TDCP. None of these compounds is classified as a human carcinogen. The environmental toxicity of phosphate FRs is low (except for TPP, TCEP and TBEP. They are not stable compounds, in living organisms they are metabolised and quickly excreted. Therefore, they can be used as an alternative to PBDEs. Med. Pr. 2015;66(2:235–264

  16. Degradation of organophosphorus compounds by X-ray irradiation

    International Nuclear Information System (INIS)

    Trebse, P.; Arcon, I.

    2002-01-01

    Complete text of publication follows. Our research presented in this contribution aims to elucidate the degradation mechanisms of organophosphate pesticides as organic pollutants by X-ray irradiation. Diazinon, one of the most widely used pesticides in Slovenia, has been chosen as a model compound for the study of radiation induced degradation of organophosphorus pesticides. Recent studies have shown that the degradation of the pesticide at normal conditions (room temperature, exposure to daylight) is strongly enhanced when the pesticide is exposed to UV light (Hg lamp, λ=254 nm, XeCl excimer laser, λ=308 nm). In our study we irradiated the pesticide in aqueous media with a white x-ray beam from a conventional x-ray source. Mo X-ray tube operating at the high voltage of 55 kV and a current of 45 mA was used. The flux of the continuous X-ray beam was stabilized within 1%. Saturated water solution of the pesticide (volume: 4mL, conc. of 40 mg L -1 ) was inserted in 1 cm long lucite cell with 1 mm thick lucite windows. The whole volume of the solution in the cell was exposed to the unfiltered X-ray beam. The dose rate on the sample was about 1 mGy/s. Different irradiation times between 30 min to 120 min were chosen to study the dependence of the pesticide decomposition with the absorbed dose. Solid phase extraction was employed for sample extraction from the solution, and gas chromatography was used for the identification and quantification of the compounds. The results show that the concentration of the pesticide in the solution decreases exponentially with the exposure time, i.e. with the absorbed dose. At irradiation conditions described above, the time constant of the exponential decrease was 74 min

  17. Cognitive decline, mortality, and organophosphorus exposure in aging Mexican Americans.

    Science.gov (United States)

    Paul, Kimberly C; Ling, Chenxiao; Lee, Anne; To, Tu My; Cockburn, Myles; Haan, Mary; Ritz, Beate

    2018-01-01

    Cognitive impairment is a major health concern among older Mexican Americans, associated with significant morbidity and mortality, and may be influenced by environmental exposures. To investigate whether agricultural based ambient organophosphorus (OP) exposure influences 1) the rate of cognitive decline and mortality and 2) whether these associations are mediated through metabolic or inflammatory biomarkers. In a subset of older Mexican Americans from the Sacramento Area Latino Study on Aging (n = 430), who completed modified mini-mental state exams (3MSE) up to 7 times (1998-2007), we examined the relationship between estimated ambient OP exposures and cognitive decline (linear repeated measures model) and time to dementia or being cognitively impaired but not demented (CIND) and time to mortality (cox proportional hazards model). We then explored metabolic and inflammatory biomarkers as potential mediators of these relationships (additive hazards mediation). OP exposures at residential addresses were estimated with a geographic information system (GIS) based exposure assessment tool. Participants with high OP exposure in the five years prior to baseline experienced faster cognitive decline (β = 0.038, p = 0.02) and higher mortality over follow-up (HR = 1.91, 95% CI = 1.12, 3.26). The direct effect of OP exposure was estimated at 241 (95% CI = 27-455) additional deaths per 100,000 person-years, and the proportion mediated through the metabolic hormone adiponectin was estimated to be 4% 1.5-19.2). No other biomarkers were associated with OP exposure. Our study provides support for the involvement of OP pesticides in cognitive decline and mortality among older Mexican Americans, possibly through biologic pathways involving adiponectin. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Blood cholinesterases as human biomarkers of organophosphorus pesticide exposure.

    Science.gov (United States)

    Nigg, H N; Knaak, J B

    2000-01-01

    The organophosphorus pesticides of this review were discovered in 1936 during the search for a replacement for nicotine for cockroach control. The basic biochemical characteristics of RBC AChE and BChE were determined in the 1940s. The mechanism of inhibition of both enzymes and other serine esterases was known in the 1940s and, in general, defined in the 1950s. In 1949, the death of a parathion mixer-loader dictated blood enzyme monitoring to prevent acute illness from organophosphorus pesticide intoxication. However, many of the chemical and biochemical steps for serine enzyme inhibition by OP compounds remain unknown today. The possible mechanisms of this inhibition are presented kinetically beginning with simple (by comparison) Michaelis-Menten substrate enzyme interaction kinetics. As complicated as the inhibition kinetics appear here, PBPK model kinetics will be more complex. The determination of inter- and intraindividual variation in RBC ChE and BChE was recognized early as critical knowledge for a blood esterase monitoring program. Because of the relatively constant production of RBCs, variation in RBC AChE was determined by about 1970. The source of plasma (or serum) BChE was shown to be the liver in the 1960s with the change in BChE phenotype to the donor in liver transplant patients. BChE activity was more variable than RBC AChE, and only in the 1990s have BChE individual variation questions been answered. We have reviewed the chemistry, metabolism, and toxicity of organophosphorus insecticides along with their inhibitory action toward tissue acetyl- and butyrylcholinesterases. On the basis of the review, a monitoring program for individuals mixing-loading and applying OP pesticides for commercial applicators was recommended. Approximately 41 OPs are currently registered for use by USEPA in the United States. Under agricultural working conditions, OPs primarily are absorbed through the skin. Liver P-450 isozymes catalyze the desulfurization of

  19. Asymmetric Ruthenium(II and Osmium(II Complexes with New Bidentate Polyquinoline Ligands. Synthesis and NMR Characterization

    Directory of Open Access Journals (Sweden)

    Antonino Mamo

    2010-03-01

    Full Text Available A series of Ru(II and Os(II tris-chelate complexes with new bidentate 2-pyridylquinoline ligands have been synthesized and fully characterized by EA,1H-NMR and FAB-MS techniques. The new ligands are: L1 = 4-p-methoxyphenyl-6-bromo-2-(2′- pyridylquinoline (mphbr-pq and L2 = 4-p-hydroxyphenyl-6-bromo-2-(2′-pyridyl-quinoline (hphbr-pq. The complexes studied are: [Ru(bpy2L1](PF62 (C1, [Ru(bpy2L2](PF62 (C2, [Os(bpy2L1](PF62 (C3, [Os(bpy2L2](PF62 (C4 (bpy = 2,2′-bipyridine, [Ru(dmbpy2L1](PF62 (C5, [Ru(dmbpy2L2](PF62 (C6, [Os(dmbpy2L1](PF62 (C7, and [Os(dmbpy2L2](PF62 (C8 (dmbpy = 4,4′-dimethyl-2,2′-bipyridine. Moreover, new functionalized complexes C9-C12 were obtained by the basecatalyzed direct alkylation of C2, C4, C6, and C8 with 6-bromo-1-hexene. The complete assignment of the 1H-NMR spectra for the two new ligands (L1 and L2, and their Ru(II or Os(II complexes has been accomplished using a combination of one- and two-dimensional NMR techniques. The JH,H values have been determined for the majority of the resonances.

  20. Study of neutral particles

    International Nuclear Information System (INIS)

    Bartel, W.; Bulos, F.; Eisner, A.

    1975-01-01

    The range of physics problems for which a detector emphasizing neutrals is most suitable is discussed. The primary goals are the all neutrals cross section, sigma/sub o/ (e + e - → neutrals), the characterization of the neutral energy in multi-hadronic events, the search for monoenergetic photons, and good sensitivity in the difficult region of low energy photons. Those features of multi-hadronic events which are most relevant to a neutral detector were calculated using a jet model with parameters extrapolated from SPEAR energies. These distributions are presented and discussed

  1. Dietary cumulative acute risk assessment of organophosphorus, carbamates and pyrethroids insecticides for the Brazilian population.

    NARCIS (Netherlands)

    Jardim, Andreia Nunes Oliveira; Brito, Alessandra Page; van Donkersgoed, Gerda; Boon, Polly E; Caldas, Eloisa Dutra

    Cumulative acute dietary risk assessments of organophosphorus (OPs), carbamates (CBs) and pyrethroids (PYs) were conducted for the Brazilian population. Residue data for 30786 samples of 30 foods were obtained from two national monitoring programs and one University laboratory, and consumption data

  2. Immobilization of Organophosphorus Acid Anhydrolase Mutant Y212F on Silica Nanospheres

    Science.gov (United States)

    2016-09-01

    wild type organophosphorus acid anhydrolase (OPAA) for activity on G-type chemical nerve agents and observed increased activity on the most- toxic ...eventual use in determining particle-binding efficiency and enzymatic activity ..................................................4 5. Fluoride assay...7 TABLES 1. Results of Fluoride Release Assay from DFP Testing of Y212F Enzyme, before and after Conjugation to

  3. Infrared Spectroscopic Observations on the Fate of Organophosphorus Compounds Exposed to Atmospheric Moisture. Part 3

    Science.gov (United States)

    2007-05-01

    FATE OF ORGANOPHOSPHORUS COMPOUNDS EXPOSED TO ATMOSPHERIC MOISTURE PART III. PHOSPHINES, PHOSPHITES , PHOSPHONITES, PHOSPHINITES, PHOSPHORIC ACIDS ...The investigation continues with Phosphines, Phosphites , Phosphonites, Phosphinites, Phosphoric Acids , Phosphonic Acids , Phosphinic Acids , Phosphine...infrared spectrum of di-(2-ethylhexyl) phosphoric acid as a liquid film between KBr windows is given in Figure 104. The band assignments are as follows

  4. Monoclonal antibody-based broad-specificity immunoassay for monitoring organophosphorus pesticides in environmental water samples

    Science.gov (United States)

    The extensive use of organophosphorus pesticides (OPs) in agriculture and domestic settings can result in widespread water contamination. The development of easy-to-use and rapid-screening immunoassay methods in a class-selective manner is a topic of considerable environmental interest. In this wo...

  5. Determination of organophosphorus acids by thermo-spray liquid chromatography-mass spectrometry

    NARCIS (Netherlands)

    Wils, E.R.J.; Hulst, A.G.

    1988-01-01

    The determination of thirteen organophosphorus acids, hydrolysis products of nerve agents and pesticides, by a combination of ion-pair liquid chromatography on a reversed-phase C18 column and thermospray mass spectrometry was investigated. Ammonium acetate and three tetraalkylammonium salts with

  6. RESEARCH OF HEAVY METALS, ORGANOCHLORINE AND ORGANOPHOSPHORUS PESTICIDES IN POWDERED INFANT FORMULA

    Directory of Open Access Journals (Sweden)

    M.C. Abete

    2009-02-01

    Full Text Available During the period between october 2007 and november 2008 were collected 60 samples of powdered infant formula. The analysis for the detection of heavy metals, organochlorine and organophosphorus pesticides show that the environmental situation is under control and powdered infant formula satisfies this health requisite.

  7. Tracing organophosphorus and brominated flame retardants and plasticizers in an estuarine food web

    NARCIS (Netherlands)

    Brandsma, S.H.; Leonards, P.E.G.; Leslie, H.A.; de Boer, J.

    2015-01-01

    Nine organophosphorus flame retardants (PFRs) were detected in a pelagic and benthic food web of the Western Scheldt estuary, The Netherlands. Concentrations of several PFRs were an order of magnitude higher than those of the brominated flame retardants (BFRs). However, the detection frequency of

  8. [On necessity to modify biochemical methods for detecting organophosphorus componds in chemical weapons extinction objects (review of literature)].

    Science.gov (United States)

    Prokofieva, D S; Shmurak, V I; Sadovnikov, S V; Gontcharov, N V

    2015-01-01

    The article covers problems of biochemical methods assessing organophosphorus toxic compounds in objects of chemical weapons extinction. The authors present results of works developing new, more specific and selective biochemical methods.

  9. Comparison of the Developmental and Acute Neurotoxicity of a Library of Organophosphorus Pesticides Using a Vertebrate Behavioral Assay

    Science.gov (United States)

    The U.S. Environmental Protection Agency is evaluating methods to screen and prioritize organophosphorus pesticides for neurotoxicity using behavioral tests in an in vivo, vertebrate, medium-throughput model (zebrafish; Danio rerio). Our behavioral testing paradigm assesses the e...

  10. Tetra- and hexavalent uranium forms bidentate-mononuclear complexes with particulate organic matter in a naturally uranium-enriched peatland

    International Nuclear Information System (INIS)

    Mikutta, Christian; Langner, Peggy; Bargar, John R.; Kretzschmar, Ruben

    2016-01-01

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work was to investigate the spatial distribution and molecular binding mechanisms of U in soils of an alpine minerotrophic peatland (pH 4.7–6.6, E_h = –127 to 463 mV) using microfocused X-ray fluorescence spectrometry and bulk and microfocused U L_3-edge X-ray absorption spectroscopy. The soils contained 2.3–47.4 wt % organic C, 4.1–58.6 g/kg Fe, and up to 335 mg/kg geogenic U. Uranium was found to be heterogeneously distributed at the micrometer scale and enriched as both U(IV) and U(VI) on fibrous and woody plant debris (48 ± 10% U(IV), x̄ ± σ, n = 22). Bulk U X-ray absorption near edge structure (XANES) spectroscopy revealed that in all samples U(IV) comprised 35–68% of total U (x̄ = 50%, n = 15). Shell-fit analyses of bulk U L_3-edge extended X-ray absorption fine structure (EXAFS) spectra showed that U was coordinated to 1.3 ± 0.2 C atoms at a distance of 2.91 ± 0.01 Å (x̄ ± σ), which implies the formation of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ~3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. As a result, our data indicates that U(IV/VI) complexation by natural organic matter prevents the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI).

  11. Tetra- and Hexavalent Uranium Forms Bidentate-Mononuclear Complexes with Particulate Organic Matter in a Naturally Uranium-Enriched Peatland.

    Science.gov (United States)

    Mikutta, Christian; Langner, Peggy; Bargar, John R; Kretzschmar, Ruben

    2016-10-04

    Peatlands frequently serve as efficient biogeochemical traps for U. Mechanisms of U immobilization in these organic matter-dominated environments may encompass the precipitation of U-bearing mineral(oid)s and the complexation of U by a vast range of (in)organic surfaces. The objective of this work was to investigate the spatial distribution and molecular binding mechanisms of U in soils of an alpine minerotrophic peatland (pH 4.7-6.6, E h = -127 to 463 mV) using microfocused X-ray fluorescence spectrometry and bulk and microfocused U L 3 -edge X-ray absorption spectroscopy. The soils contained 2.3-47.4 wt % organic C, 4.1-58.6 g/kg Fe, and up to 335 mg/kg geogenic U. Uranium was found to be heterogeneously distributed at the micrometer scale and enriched as both U(IV) and U(VI) on fibrous and woody plant debris (48 ± 10% U(IV), x̅ ± σ, n = 22). Bulk U X-ray absorption near edge structure (XANES) spectroscopy revealed that in all samples U(IV) comprised 35-68% of total U (x̅ = 50%, n = 15). Shell-fit analyses of bulk U L 3 -edge extended X-ray absorption fine structure (EXAFS) spectra showed that U was coordinated to 1.3 ± 0.2 C atoms at a distance of 2.91 ± 0.01 Å (x̅ ± σ), which implies the formation of bidentate-mononuclear U(IV/VI) complexes with carboxyl groups. We neither found evidence for U shells at ∼3.9 Å, indicative of mineral-associated U or multinuclear U(IV) species, nor for a substantial P/Fe coordination of U. Our data indicates that U(IV/VI) complexation by natural organic matter prevents the precipitation of U minerals as well as U complexation by Fe/Mn phases at our field site, and suggests that organically complexed U(IV) is formed via reduction of organic matter-bound U(VI).

  12. On neutral plasma oscillations

    International Nuclear Information System (INIS)

    Shadwick, B.A.; Morrison, P.J.

    1993-06-01

    We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can possess positive or negative free energy

  13. Neutral beam monitoring

    International Nuclear Information System (INIS)

    Fink, J.H.

    1979-01-01

    A neutral beam generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange partially neutralizes the high energy beam, is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are identified. (U.K.)

  14. On neutral plasma oscillations

    International Nuclear Information System (INIS)

    Shadwick, B.A.; Texas Univ., Austin; Morrison, P.J.; Texas Univ., Austin

    1994-01-01

    We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can posses positive or negative free energy. (orig.)

  15. Search for neutral leptons

    International Nuclear Information System (INIS)

    Perl, M.L.

    1984-12-01

    At present we know of three kinds of neutral leptons: the electron neutrino, the muon neutrino, and the tau neutrino. This paper reviews the search for additional neutral leptons. The method and significance of a search depends upon the model used for the neutral lepton being sought. Some models for the properties and decay modes of proposed neutral leptons are described. Past and present searches are reviewed. The limits obtained by some completed searches are given, and the methods of searches in progress are described. Future searches are discussed. 41 references

  16. Synthesis and photoluminescence properties of novel Schiff base type polymer-rare earth complexes containing furfural-based bidentate Schiff base ligands

    Science.gov (United States)

    Gao, Baojiao; Zhang, Dandan; Li, Yanbin

    2018-03-01

    Luminescent polymer-rare earth complexes are an important class of photoluminescence and electroluminescence materials. Via molecular design, two furfural-based bidentate Schiff base ligands, furfural-aniline (FA) type ligand and furfural-cyclohexylamine (FC) type ligand, were bonded on the side chains of polysulfone (PSF), respectively, forming two functionalized macromolecules, PSF-FA and PSF-FC. And then through respective coordination reactions of the two functionalized macromolecules with Eu(Ⅲ) ion and Tb(Ⅲ) ion, novel luminescent binary and ternary (with 1,10-phenanthroline as the second ligand) polymer-rare earth complexes were synthesized. For these complexes, on basis of the characterization of their chemical structures, they photoluminescence properties were main researched, and the relationship between their luminescent properties and structures was explored. The experimental results show that the complexes coming from PSF-FA and Eu(Ⅲ) ion including binary and ternary complexes emit strong red luminescence, indicating that the bonded bidentate Schiff base ligand FA can sensitize the fluorescence emission of Eu(III) ion. While the complexes coming from PSF-FC and Tb(Ⅲ) ion produce green luminescence, displaying that the bonded bidentate Schiff base ligand FC can sensitize the fluorescence emission of Tb(Ⅲ) ion. The fluorescence emission intensities of the ternary complexes were stronger than that of binary complexes, reflecting the important effect of the second ligand. The fluorescence emission of the solid film of complexes is much stronger than that of the solutions of complexes. Besides, by comparison, it is found that the furfural (as a heteroaromatic compound)-based Schiff base type polymer-rare earth complexes have stronger fluorescence emission and higher energy transfer efficiency than salicylaldehyde (as a common aromatic compound)-based Schiff base type polymer-rare earth complexes.

  17. Syntheses and crystal structures of two novel alkaline uranyl chromates A2(UO2)(CrO4)2 (A=Rb, Cs) with bidentate coordination mode of uranyl ions by chromate anions

    International Nuclear Information System (INIS)

    Siidra, Oleg I.; Nazarchuk, Evgeny V.; Krivovichev, Sergey V.

    2012-01-01

    Single crystals of Cs 2 (UO 2 )(CrO 4 ) 2 and Rb 2 (UO 2 )(CrO 4 ) 2 were prepared by solid state reactions. The structures are based upon the [(UO 2 )(CrO 4 ) 2 ] 2− chains. Within the chains, UrO 5 pentagonal bipyramids (Ur=uranyl) form Ur 2 O 8 dimers, which are linked via CrO 4 tetrahedra into one-dimensional chains. The CrO 4 tetrahedra coordinate uranyl ions in both mono- and bidentate fashion, which is unusual for uranyl chromates. The bidentate coordination has a strong influence upon geometrical parameters of both U and Cr coordination polyhedra. The conformation of the chains in 1 and 2 is different due to the different size of the Cs + and Rb + cations. - Graphical abstract: Uranyl chromate chain with monodentate and bidentate coordination mode of uranyl cations by CrO 4 tetrahedra in Cs 2 (UO 2 )(CrO 4 ) 2 . Highlights: ► Single crystals of novel uranyl chromates were prepared by solid state reactions. ► The CrO 4 tetrahedra coordinate uranyl ions in both mono- and bidentate fashion. ►The bidentate coordination has a strong influence upon geometrical parameters.

  18. Comparative study on cleanup procedures for the determination of organophosphorus pesticides in vegetables

    International Nuclear Information System (INIS)

    Alvin, Chai Lian Kuet; Lau, Seng

    2008-01-01

    A study was carried out to compare the cleanup procedures for the determination of organophosphorus pesticides in vegetables. Eleven organophosphorus pesticides were extracted with acetone and methylene chloride. Extracts were cleanup by solid-phase extraction (SPE) mixed-mode column using quaternary amine and aminopropyl (SAX/ NH 2 ) or octadecyl (C 18 ) sorbents. The pesticides were determined by gas chromatography with flame photometric detector. The recovery results obtained from the SPE SAX/ NH 2 and C 18 cleanups in carrot, cucumber and green mustard samples were in the range of 71.0 % to 115 %. Lower recoveries were obtained for polar pesticides, methamidophos and dimethoate. These results were compared to the method currently used in the laboratory which does not include any cleanup. (author)

  19. Calcium uptake by sarcoplasmic reticulum in the presence of organophosphorus insecticide methyl-parathion

    International Nuclear Information System (INIS)

    Blasiak, J.

    1995-01-01

    Using an isotope labelling technique it has been shown that an organophosphorus insecticide methyl parathion (0,0-diethyl 0-4-nitrophenyl phosphorothionate) depressed calcium uptake by sarcoplasmic reticulum isolated from rabbit hind leg muscle. The effect was significant for insecticide concentrations of 50 and 100 μM and was dose-dependent. The insecticide exerted a more pronounced effect on calcium uptake in the presence of ATP in the reticulum environment than in the absence of ATP. The inhibitory action of methyl parathion on Ca 2+ accumulation by sarcoplasmic reticulum can cause a rise in myoplasmic free Ca 2+ , the essential prerequisite for contracture activation. Because methyl parathion, as well as other organophosphorus insecticides, is primarily neurotoxic, evidence of non-specific effect could be important for assessing its environmental safety. (author). 20 refs, 2 figs

  20. Organophosphorus insecticides: Toxic effects and bioanalytical tests for evaluating toxicity during degradation processes

    Directory of Open Access Journals (Sweden)

    Čolović Mirjana B.

    2013-01-01

    Full Text Available Organophosphorus insecticides have been the most applied group of insecticides for the last two decades. Their main toxic effects are related to irreversible inactivation of acetylcholinesterase (AChE. Actually, they covalently bind to serine OH group in the enzyme active site forming phosphorylated enzyme that cannot hydrolyze acetylcholine. Organophosphorus insecticides in the environment undergo the natural degradation pathway including mainly homogeneous and heterogeneous hydrolysis (especially at high pH generating non-inhibiting products. Additionally, thio organophosphates are easily oxidized by naturally present oxidants and UV light, forming more toxic and stable oxons. Thus, oxidative degradation procedures, generally referred as advanced oxidation processes (AOP, have been applied for their efficient removal from contaminated waters. The most applied bioassays to monitor the organophosphate toxicity i.e. the detoxification degree during AOP are Vibrio fischeri and AChE bioassays. Vibrio fischeri toxicity test exploits bioluminescence as the measure of luciferase activity of this marine bacterium, whereas AChE bioassay is based on AChE activity inhibition. Both bioanalytical techniques are rapid (several minutes, simple, sensitive and reproducible. Vibrio fischeri test seems to be a versatile indicator of toxic compounds generated in AOP for organophosphorus insecticides degradation. However, detection of neurotoxic AChE inhibitors, which can be formed in AOP of some organophosphates, requires AChE bioassays. Therefore, AChE toxicity test is more appropriate for monitoring the degradation processes of thio organophosphates, because more toxic oxo organophosphates might be formed and overlooked by Vibrio fischeri bioluminescence inhibition. In addition, during organophosphates removal by AOP, compounds with strong genotoxic potential may be formed, which cannot be detected by standard toxicity tests. For this reason, determination of

  1. Organophosphorus acid anhydrolase from Alteromonas macleodii: structural study and functional relationship to prolidases

    Czech Academy of Sciences Publication Activity Database

    Štěpánková, Andrea; Dušková, Jarmila; Skálová, Tereza; Hašek, Jindřich; Koval, Tomáš; Ostergaard, L. H.; Dohnálek, Jan

    2013-01-01

    Roč. 69, č. 4 (2013), s. 346-354 ISSN 1744-3091 R&D Projects: GA ČR GA310/09/1407; GA ČR GA305/07/1073; GA MŠk EE2.3.30.0029 Institutional research plan: CEZ:AV0Z40500505 Institutional support: RVO:61389013 Keywords : organophosphorus acid anhydrolase * prolidases * bifunctional Subject RIV: CE - Biochemistry Impact factor: 0.568, year: 2013

  2. A Common Mechanism for Resistance to Oxime Reactivation of Acetylcholinesterase Inhibited by Organophosphorus Compounds

    Science.gov (United States)

    2013-01-01

    reactivated than AChE conjugates inhibited by the corresponding Rp enantiomers and this effect is enhanced as the size of the O-alkyl substituents of OP...Organophosphates and Carbamates, Butterworth & Heinemann , Oxford, 1992. pp. 555–577. [2] P. Taylor, Anticholinesterase agents, in: L.L. Brunton, J.S...application of the Hammett equation with the constants rph in the chemistry of organophosphorus compounds, Russ. Chem. Rev. 38 (1969) 795–811. [13

  3. Neutralized transport experiment

    International Nuclear Information System (INIS)

    Roy, P.K.; Yu, S.S.; Eylon, S.; Henestroza, E.; Anders, A.; Gilson, E.P.; Bieniosek, F.M.; Greenway, W.G.; Logan, B.G.; Waldron, W.L.; Shuman, D.B.; Vanecek, D.L.; Welch, D.R.; Rose, D.V.; Thoma, C.; Davidson, R.C.; Efthimion, P.C.; Kaganovich, I.; Sefkow, A.B.; Sharp, W.M.

    2005-01-01

    Experimental details on providing active neutralization of high brightness ion beam have been demonstrated for Heavy Ion Fusion program. A K + beam was extracted from a variable-perveance injector and transported through 2.4 m long quadrupole lattice for final focusing. Neutralization was provided by a localized cathode arc plasma plug and a RF volume plasma system. Effects of beam perveance, emittance, convergence focusing angle, and axial focusing position on neutralization have been investigated. Good agreement has been observed with theory and experiment throughout the study

  4. Long Alkyl Chain Organophosphorus Coupling Agents for in Situ Surface Functionalization by Reactive Milling

    Directory of Open Access Journals (Sweden)

    Annika Betke

    2014-08-01

    Full Text Available Innovative synthetic approaches should be simple and environmentally friendly. Here, we present the surface modification of inorganic submicrometer particles with long alkyl chain organophosphorus coupling agents without the need of a solvent, which makes the technique environmentally friendly. In addition, it is of great benefit to realize two goals in one step: size reduction and, simultaneously, surface functionalization. A top-down approach for the synthesis of metal oxide particles with in situ surface functionalization is used to modify titania with long alkyl chain organophosphorus coupling agents. A high energy planetary ball mill was used to perform reactive milling using titania as inorganic pigment and long alkyl chain organophosphorus coupling agents like dodecyl and octadecyl phosphonic acid. The final products were characterized by IR, NMR and X-ray fluorescence spectroscopy, thermal and elemental analysis as well as by X-ray powder diffraction and scanning electron microscopy. The process entailed a tribochemical phase transformation from the starting material anatase to a high-pressure modification of titania and the thermodynamically more stable rutile depending on the process parameters. Furthermore, the particles show sizes between 100 nm and 300 nm and a degree of surface coverage up to 0.8 mmol phosphonate per gram.

  5. Are "Market Neutral" Hedge Funds Really Market Neutral?

    OpenAIRE

    Andrew J. Patton

    2009-01-01

    Using a variety of different definitions of "neutrality," this study presents significant evidence against the neutrality to market risk of hedge funds in a range of style categories. I generalize standard definitions of "market neutrality," and propose five different neutrality concepts. I suggest statistical tests for each neutrality concept, and apply these tests to a database of monthly returns on 1423 hedge funds from five style categories. For the "market neutral" style, approximately o...

  6. Bunched beam neutralization

    International Nuclear Information System (INIS)

    Gammel, G.M.; Maschke, A.W.; Mobley, R.M.

    1979-01-01

    One of the steps involved in producing an intense ion beam from conventional accelerators for Heavy Ion Fusion (HIF) is beam bunching. To maintain space charge neutralized transport, neutralization must occur more quickly as the beam bunches. It has been demonstrated at BNL that a 60 mA proton beam from a 750 kV Cockcroft--Walton can be neutralized within a microsecond. The special problem in HIF is that the neutralization must occur in a time scale of nanoseconds. To study neutralization on a faster time scale, a 40 mA, 450 kV proton beam was bunched at 16 MHz. A biased Faraday cup sampled the bunched beam at the position where maximum bunching was nominally expected, about 2.5 meters from the buncher. Part of the drift region, about 1.8 meters, was occupied by a series of Gabor lenses. In addition to enhancing beam transport by transverse focussing, the background cloud of electrons in the lenses provided an extra degree of neutralization. With no lens, the best bunch factor was at least 20. Bunch factor is defined here as the ratio of the distance between bunches to the FWHM bunch length. With the lens, it was hoped that the increased plasma frequency would decrease the neutralization time and cause an increase in the bunch factor. In fact, with the lens, the instantaneous current increased about three times, but the bunch factor dropped to about 10. Even with the lens, the FWHM of the bunches at the position of maximum bunching was still comparable to or less than the oscillation period of the surrounding electron plasma. Thus, the electron density in the lens must increase before neutralization could be effective in this case, or bunching should be done at a lower frequency

  7. A STUDY OF PREDICTING THE NEED FOR VENTILATOR SUPPORT AND OUTCOME IN ORGANOPHOSPHORUS POISONING

    Directory of Open Access Journals (Sweden)

    Kalinga Bommankatte Eranaik

    2017-04-01

    Full Text Available BACKGROUND Organophosphorus compound poisoning is the most common poisonings in India because of easy availability, often requiring ICU care and ventilator support. Clinical research has indicated that respiratory failure is the most important cause of death due to Organophosphorus poisoning. It results in respiratory muscle weakness, pulmonary oedema, respiratory depression, increased secretions and bronchospasm. These complications and death can be prevented with timely Institution of ventilator support. The aim of present study was to identify the factors and predicting the need for ventilator support and outcome. Aim of the Study- To predict the need for ventilator support and outcome in organophosphate poisoning. MATERIALS AND METHODS Seventy consecutive patients admitted with a history of organophosphorus poisoning at KIMS, Hubli were taken for study after considering the inclusion and exclusion criteria. Detailed history, confirmation of poisoning, examination and other than routine investigations serum pseudocholinesterase and arterial blood gas analysis was done. The severity of organophosphorus poisoning was graded as mild, moderate and severe based on the factors which influence the need for ventilator support. RESULTS This study was conducted in 70 patients, out of which 48 (68.6% were male patients and 22 (31.4% were female patients. Among them 37 (53% patients required ventilation and 33 (47% expired. Chlorpyrifos, Dichlorvos and Monocrotophos were most commonly consumed poisons. 74% patients who consumed these compounds required ventilator support and 73% patients expired. 100% of patients presented with pin point pupil, fasciculation score > 4, respiratory rate > 20, GCS score < 7 and severe grade of poisoning required ventilator support and pseudocholinesterase < 900 U/L, 70% of metabolic acidosis and atropine requirement more than 180 mg within 48 hours required ventilator support and associated with high mortality. CONCLUSION

  8. Polymer sensors based on extraction systems for the determination of rare earth metals

    International Nuclear Information System (INIS)

    Kirsanov, D.O.; Legin, A.V.; Babain, V.A.; Vlasov, Yu.G.

    2005-01-01

    New polymeric sensors on the basis of bidentate neutral organophosphorus compounds of various structure, doped with chlorinated cobalt dicarbollide are proposed; the sensors feature high sensitivity to Fe 3+ , Y 3+ , La 3+ , Pr 3+ , Nd 3+ , and Eu 3+ cations in a wide concentration range at pH 2. The selectivity, detection limits, and pH dependence of the potential of the sensors are studied. The influence of chlorinated cobalt dicarbollide on electrochemical characteristics of the sensors is demonstrated [ru

  9. Bidentate Ligand-passivated CsPbI3 Perovskite Nanocrystals for Stable Near-unity Photoluminescence Quantum Yield and Efficient Red Light-emitting Diodes

    KAUST Repository

    Pan, Jun

    2017-12-17

    Although halide perovskite nanocrystals (NCs) are promising materials for optoelectronic devices, they suffer severely from chemical and phase instabilities. Moreover, the common capping ligands like oleic acid and oleylamine that encapsulate the NCs will form an insulating layer, precluding their utility in optoelectronic devices. To overcome these limitations, we develop a post-synthesis passivation process for CsPbI3 NCs by using a bidentate ligand, namely 2,2’-Iminodibenzoic acid. Our passivated NCs exhibit narrow red photoluminescence with exceptional quantum yield (close to unity) and substantially improved stability. The passivated NCs enabled us to realize red light-emitting diodes (LEDs) with 5.02% external quantum efficiency and 748 cd/m2 luminance, surpassing by far LEDs made from the non-passivated NCs.

  10. Cd(II) and Zn(II) Complexes Containing N,N'-Bidentate N-(Pyridin-2-ylmethylene)cyclopentanamine: Synthesis, Characterisation and Methyl Methacrylate Polymerisation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yu Jin; Lee, Ha Jun; Lee, Hyo Sun [Kyungpook National University, Daeju (Korea, Republic of)

    2014-09-15

    The reaction between [CdBr{sub 2}·4H{sub 2}O] and anhydrous [ZnCl{sub 2}] with N,N'-bidentate N-(pyridin-2-ylmethylene)- cyclopentanamine (impy) in ethanol yields dimeric [(impy)Cd(μ-Br)Br]2 and monomeric [(impy)ZnCl{sub 2}] complexes, respectively. The X-ray crystal structure of Cd(II) and Zn(II) complexes revealed that the cadmium atom in [(impy)Cd(μ-Br)Br]2 and zinc in [(impy)ZnCl{sub 2}] formed a distorted trigonal–bipyramidal and tetrahedral geometry, respectively. Both complexes showed moderate catalytic activity for the polymerisation of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO), with polymethylmethacrylate (PMMA) syndiotacticity of about 0.70.

  11. Bidentate Ligand-passivated CsPbI3 Perovskite Nanocrystals for Stable Near-unity Photoluminescence Quantum Yield and Efficient Red Light-emitting Diodes

    KAUST Repository

    Pan, Jun; Shang, Yuequn; Yin, Jun; de Bastiani, Michele; Peng, Wei; Dursun, Ibrahim; Sinatra, Lutfan; El-Zohry, Ahmed M.; Hedhili, Mohamed N.; Emwas, Abdul-Hamid M.; Mohammed, Omar F.; Ning, Zhijun; Bakr, Osman

    2017-01-01

    Although halide perovskite nanocrystals (NCs) are promising materials for optoelectronic devices, they suffer severely from chemical and phase instabilities. Moreover, the common capping ligands like oleic acid and oleylamine that encapsulate the NCs will form an insulating layer, precluding their utility in optoelectronic devices. To overcome these limitations, we develop a post-synthesis passivation process for CsPbI3 NCs by using a bidentate ligand, namely 2,2’-Iminodibenzoic acid. Our passivated NCs exhibit narrow red photoluminescence with exceptional quantum yield (close to unity) and substantially improved stability. The passivated NCs enabled us to realize red light-emitting diodes (LEDs) with 5.02% external quantum efficiency and 748 cd/m2 luminance, surpassing by far LEDs made from the non-passivated NCs.

  12. Neutral beam development plan

    International Nuclear Information System (INIS)

    Staten, H.S.

    1980-08-01

    The national plan is presented for developing advanced injection systems for use on upgrades of existing experiments, and use on future facilities such as ETF, to be built in the late 1980's or early 90's where power production from magnetic fusion will move closer to a reality. Not only must higher power and longer pulse length systems be developed , but they must operate reliably; they must be a tool for the experimenter, not the experiment itself. Neutral beam systems handle large amounts of energy and as such, they often are as complicated as the plasma physics experiment itself. This presents a significant challenge to the neutral beam developer

  13. Neutral beam program

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The structure of the beam injection program for the Doublet-3 device is discussed. The design considerations for the beam line and design parameters for the Doublet-3 ion souce are given. Major components of the neutral beam injector system are discussed in detail. These include the neutralizer, magnetic shielding, reflecting magnets, vacuum system, calorimeter and beam dumps, and drift duct. The planned location of the two-injector system for Doublet-3 is illustrated and site preparation is considered. The status of beamline units 1 and 2 and the future program schedule are discussed

  14. Mod en neutral seksualitet!

    DEFF Research Database (Denmark)

    Leer, Jonatan

    2013-01-01

    Towards a Neutral Sexuality! or Roland Barthes as a Queer Thinker? This article argues that the work of Roland Barthes has interesting perspectives in common with the queer theory. This argument will be put forward by using his concept of ‘the neutral’ that Barthes defines as “that which outplays...

  15. Issues in neutral currents

    International Nuclear Information System (INIS)

    Sehgal, L.M.

    1980-01-01

    The experimental results on low energy confirming the structure of the effective Lagrangian of the weak neutral current processes as predicted by the Salam-Weinberg model are reviewed. Some possible modifications of the effective Lagrangian and the feasibility of their experimental verification are also considered. (P.L.)

  16. ITER neutral beam system

    International Nuclear Information System (INIS)

    Mondino, P.L.; Di Pietro, E.; Bayetti, P.

    1999-01-01

    The Neutral Beam (NB) system for the International Thermonuclear Experimental Reactor (ITER) has reached a high degree of integration with the tokamak and with the rest of the plant. Operational requirements and maintainability have been considered in the design. The paper considers the integration with the tokamak, discusses design improvements which appear necessary and finally notes R and D progress in key areas. (author)

  17. Levels and distribution of organophosphorus flame retardants and plasticizers in fishes from Manila Bay, the Philippines

    International Nuclear Information System (INIS)

    Kim, Joon-Woo; Isobe, Tomohiko; Chang, Kwang-Hyeon; Amano, Atsuko; Maneja, Rommel H.; Zamora, Peter B.; Siringan, Fernando P.; Tanabe, Shinsuke

    2011-01-01

    Organophosphorus compounds (OPCs) and stable isotope ratios (δ 13 C and δ 15 N) were determined in 58 fishes belonging to 20 species collected from Manila Bay, the Philippines. OPCs were detected in most of the samples and found up to μg/g lw (lipid weight) level, suggesting their ubiquitous presence in the coastal marine environment of the Philippines. Higher levels (>1000 ng/g lw) of total OPCs were determined in yellowstriped goatfish, silver sillago, tripletail wrasse and bumpnose trevally indicates either their active uptake from ambient water or lower metabolic capacity of these species. Levels of triphenyl phosphate (TPhP) in demersal species showed a positive correlation with δ 15 N, indicating that TPhP was adsorbed onto the particle, settled down to the bottom sediment and accumulated through the benthic food web rather than the pelagic. Estimated dietary intake of OPCs in Manila Bay fishes were four to five orders of magnitude lower than the proposed reference dose (RfD). - Highlights: → Organophosphorus compounds (OPCs) were determined in fish from Manila Bay. → OPCs were detected up to μg/g lw, suggesting ubiquitous environmental contamination. → Among the 9 targeted OPCs, TEHP and TEP were found as the predominant compounds. → Estimated dietary intake through fish consumption was 4-5 orders of magnitude lower than RfD. → This is the first report on OPCs pollution in marine environment of Southeast Asia. - Occurrence and bioaccumulation of organophosphorus compounds (OPCs) were determined in fishes from Manila Bay.

  18. Determination of Twenty Organophosphorus Pesticides in Wheat Samples from Different Regions of Iran

    Directory of Open Access Journals (Sweden)

    Attaollah Shakoori *

    2017-09-01

    Full Text Available Background: Organophosphorus pesticides are widely used in agriculture, homes, gardens, and veterinary practices. Extensive application of pesticides in agriculture often results in residues of these compounds being absorbed into the foods, including wheat. The aim of this study was to evaluate the residue levels of 20 organophosphorus pesticides in wheat samples collected from different regions of Iran. Methods: This research reports a rapid, specific and sensitive multiresidue method based on the Quick Easy Cheap Effective Rugged and Safe (QuEChERS sample preparation method and gas chromatography with mass spectrometric detection in the selected ion monitoring mode (GC–SIM–MS to evaluate 20 organophosphorus pesticides in wheat samples. Results: In the concentration range of 20-200 ng/g, the calibration curves for each analyte was linear with a determination coefficient (R2 of 0.993 to 0.999. The limits of detection (LODs and quantitation (LOQs were between 2.5-6.7 and 7.5-20 ng/g, respectively. The mean recoveries obtained for three fortification levels (25, 50 and 100 ng/g, five replicates each were 80-114% with a satisfactory precision (RSD<20%. 31.1% samples contained residues of one or more target compounds. Chlorpyrifos was the most common residue (17.8%, followed by pirimiphos-methyl (6.7%, diazinon (4.4%, chlorpyrifos-methyl (1.1% and malathion (1.1%. Conclusion: Among the detected pesticides, only diazinon and malathion are permitted pesticides for wheat production in Iran. However, their concentrations were below the maximum residue levels (MRLs established by the Iranian National Standard Organization (INSO.

  19. Simple, specific analysis of organophosphorus and carbamate pesticides in sediments using column extraction and gas chromatography

    Science.gov (United States)

    Belisle, A.A.; Swineford, D.M.

    1988-01-01

    A simple, specific procedure was developed for the analysis of organophosphorus and carbamate pesticides in sediment. The wet soil was mixed with anhydrous sodium sulfate to bind water and the residues were column extracted in acetone:methylene chloride (1:l,v/v). Coextracted water was removed by additional sodium sulfate packed below the sample mixture. The eluate was concentrated and analyzed directly by capillary gas chromatography using phosphorus and nitrogen specific detectors. Recoveries averaged 93 % for sediments extracted shortly after spiking, but decreased significantly as the samples aged.

  20. Pralidoxime in acute organophosphorus insecticide poisoning--a randomised controlled trial.

    Directory of Open Access Journals (Sweden)

    Michael Eddleston

    2009-06-01

    Full Text Available Poisoning with organophosphorus (OP insecticides is a major global public health problem, causing an estimated 200,000 deaths each year. Although the World Health Organization recommends use of pralidoxime, this antidote's effectiveness remains unclear. We aimed to determine whether the addition of pralidoxime chloride to atropine and supportive care offers benefit.We performed a double-blind randomised placebo-controlled trial of pralidoxime chloride (2 g loading dose over 20 min, followed by a constant infusion of 0.5 g/h for up to 7 d versus saline in patients with organophosphorus insecticide self-poisoning. Mortality was the primary outcome; secondary outcomes included intubation, duration of intubation, and time to death. We measured baseline markers of exposure and pharmacodynamic markers of response to aid interpretation of clinical outcomes. Two hundred thirty-five patients were randomised to receive pralidoxime (121 or saline placebo (114. Pralidoxime produced substantial and moderate red cell acetylcholinesterase reactivation in patients poisoned by diethyl and dimethyl compounds, respectively. Mortality was nonsignificantly higher in patients receiving pralidoxime: 30/121 (24.8% receiving pralidoxime died, compared with 18/114 (15.8% receiving placebo (adjusted hazard ratio [HR] 1.69, 95% confidence interval [CI] 0.88-3.26, p = 0.12. Incorporating the baseline amount of acetylcholinesterase already aged and plasma OP concentration into the analysis increased the HR for patients receiving pralidoxime compared to placebo, further decreasing the likelihood that pralidoxime is beneficial. The need for intubation was similar in both groups (pralidoxime 26/121 [21.5%], placebo 24/114 [21.1%], adjusted HR 1.27 [95% CI 0.71-2.29]. To reduce confounding due to ingestion of different insecticides, we further analysed patients with confirmed chlorpyrifos or dimethoate poisoning alone, finding no evidence of benefit.Despite clear reactivation of

  1. Basicity determination for neutral phosphorus organic extragents by NMR 31P-method in two-phase systems, and quantitative interrelations of acido-basic extractive properties

    International Nuclear Information System (INIS)

    Laskorin, B.N.; Yakshin, V.V.; Meshcheryakov, N.M.; Yagodin, V.G.

    1988-01-01

    Consideration is given to the method for determination of basicity of neutral organophosphorus compounds of XGZP=0 type (X, G, Z=C 4 H 9 , C 8 H 17 , C 6 H 5 ). The method is based on change of chemical shift of phosphorus-31 nuclei in two-phase extraction system depending on acidity function H O , H A , H PO . It is shown that the method can be used for evaluation and forecasting of phosphine oxide ability in the processes of UO 2 SO 4 solvent extraction from aqueous solutions of sulfuric acid

  2. Antihypertensive neutral lipid

    Science.gov (United States)

    Snyder, F.L.; Blank, M.L.

    1984-10-26

    The invention relates to the discovery of a class of neutral acetylated either-linked glycerolipids having the capacity to lower blood presure in warm-blooded animals. This physiological effect is structure sensitive requiring a long chain alkyl group at the sn-1 position and a short carbon chain acyl group (acetyl or propionyl) at the sn-2 position, and a hydroxyl group at the sn-3 position.

  3. Exercise Equipment: Neutral Buoyancy

    Science.gov (United States)

    Shackelford, Linda; Valle, Paul

    2016-01-01

    Load Bearing Equipment for Neutral Buoyancy (LBE-NB) is an exercise frame that holds two exercising subjects in position as they apply counter forces to each other for lower extremity and spine loading resistance exercises. Resistance exercise prevents bone loss on ISS, but the ISS equipment is too massive for use in exploration craft. Integrating the human into the load directing, load generating, and motion control functions of the exercise equipment generates safe exercise loads with less equipment mass and volume.

  4. Neutral beams for mirrors

    International Nuclear Information System (INIS)

    Fink, J.H.

    1983-01-01

    An important demonstration of negative ion technology is proposed for FY92 in the MFTF-α+T, an upgrade of the Mirror Fusion Test Facility at the Lawrence Livermore National Laboratory. This facility calls for 200-keV negative ions to form neutral beams that generate sloshing ions in the reactor end plugs. Three different beam lines are considered for this application. Their advantages and disadvantages are discussed

  5. Gargamelle: neutral current event

    CERN Multimedia

    1973-01-01

    This event shows real tracks of particles from the 1200 litre Gargamelle bubble chamber that ran on the PS from 1970 to 1976 and on the SPS from 1976 to 1979. In this image a neutrino passes close to a nucleon and reemerges as a neutrino. Such events are called neutral curent, as they are mediated by the Z0 boson which has no electric charge.

  6. Climate Neutral Campus Key Terms and Definitions | Climate Neutral Research

    Science.gov (United States)

    Campuses | NREL Neutral Campus Key Terms and Definitions Climate Neutral Campus Key Terms and Definitions The term climate neutral evolved along with net zero and a number of other "green" and accuracy in these areas lets research campuses know exactly how close they are to climate

  7. Construction of genetically engineered bacteria that degrades organophosphorus pesticide residues and can be easily detected by the fluorescence.

    Science.gov (United States)

    Li, Qin; Wang, Pan; Chen, Rui; Li, Wei; Wu, Yi-Jun

    2014-01-01

    Organophosphorus compounds (OPs) are widely used in agriculture and industry and there is increased concern about their toxicological effects in the environment. Bioremediation can offer an efficient and cost-effective option for the removal of OPs. Herein, we describe the construction of a genetically engineered microorganism (GEM) that can degrade OPs and be directly detected and monitored in the environment using an enhanced green fluorescent protein (EGFP) fusion strategy. The coding regions of EGFP, a reporter protein that can fluoresce by itself, and organophosphorus hydrolase (OPH), which has a broad substrate specificity and is able to hydrolyse a number of organophosphorus pesticides, were cloned into the expression vector pET-28b. The fusion protein of EGFP-OPH was expressed in E. coli BL21 (DE3) and the protein expression reached the highest level at 11 h after isopropyl beta-D-thiogalactopyranoside induction. The fluorescence of the GEM was detected by fluorescence spectrophotometry and microscopy, and its ability to degrade OPs was determined by OPH activity assay. Those GEM that express the fusion protein (EGFP and OPH) exhibited strong fluorescence intensity and also potent hydrolase activity, which could be used to degrade organophosphorus pesticide residues in the environment and can also be directly monitored by fluorescence.

  8. AMPEROMETRIC THICK-FILM STRIP ELECTRODES FOR MONITORING ORGANOPHOSPHATE NERVE AGENTS BASED ON IMMOBILIZED ORGANOPHOSPHORUS HYDROLASE. (R823663)

    Science.gov (United States)

    An amperometric biosensor based on the immobilization of organophosphorus hydrolase(OPH) onto screen-printed carbon electrodes is shown useful for the rapid, sensitive, and low-costdetection of organophosphate (OP) nerve agents. The sensor relies upon the sensitive and ra...

  9. DEVELOPMENT OF A RISK ASSESSMENT MODEL FOR THE EFFECTS OF ORGANOPHOSPHORUS PESTICIDES ON INFECTIOUS DISEASE SUSCEPTIBILITY AND THE IMMUNE SYSTEM

    Science.gov (United States)

    There is increased concern about the sublethal effects of organophosphorus (OP) pesticides on human and animal health. This class of chemicals has been shown to affect the immune function of macrophages and lymphocytes. Malathion, an OP compound, is one of the most widely used ...

  10. Structural Analysis and Bioengineering of Thermostable Pyrococcus furiosus Prolidase for the Optimization of Organophosphorus Nerve Agent Detoxification

    Science.gov (United States)

    2012-04-26

    organophosphorus acid anhydrase from a halophilic bacterial isolate. J Bacteriol, 173, 1938-1943. Du, X., Tove, S., Kast -Hutcheson, K. & Grunden, A. M...1938-1943. Du, X., Tove, S., Kast -Hutcheson, K. & Grunden, A. M. 2005. Characterization of the dinuclear metal center of Pyrococcus furiosus

  11. Confirmed organophosphorus and carbamate pesticide poisonings in South African wildlife (2009–2014

    Directory of Open Access Journals (Sweden)

    Christo J. Botha

    2015-12-01

    Full Text Available During a six-year period (from January 2009 to December 2014, specimens collected from 344 cases of suspected organophosphorus and carbamate pesticide poisonings in wildlife, including birds, were submitted to the Toxicology Laboratory (ARC-OVI for analysis. A positive diagnosis was made in 135 (39% of these cases. The majority of cases were from birds, which included Cape vultures (Gyps coprotheres and African white-backed vultures (Gyps africanus and bateleur eagles (Terathopius ecaudatus. In one incident 49 vultures were killed when a farmer intentionally laced carcasses with carbofuran in an attempt to control jackal predation. There were 22 incidents of poisoning in helmeted guineafowl (Numida meleagris. On nine different occasions blue cranes (Anthropoides paradiseus were poisoned, in one incident 14 birds were reported to have been killed. Over the period of investigation, there were 20 cases of poisoning involving mammalian species, the majority being vervet monkeys (Chlorocebus pygerythrus. The carbamate pesticides were responsible for 57 incidents of poisoning. Aldicarb, carbofuran and methomyl were detected in 26, 18 and 12 cases respectively. The majority of organophosphorus pesticide poisonings were caused by diazinon (n = 19, monocrotophos (n = 13 and methamidophos (n = 10.

  12. In vivo tracing of organophosphorus pesticides in cabbage (Brassica parachinensis) and aloe (Barbadensis)

    Energy Technology Data Exchange (ETDEWEB)

    Qiu, Junlang; Chen, Guosheng; Zhou, Hong; Xu, Jianqiao; Wang, Fuxin; Zhu, Fang, E-mail: ceszf@mail.sysu.edu.cn; Ouyang, Gangfeng, E-mail: cesoygf@mail.sysu.edu.cn

    2016-04-15

    In vivo solid-phase microextraction (SPME) sampling method coupled with gas chromatography–mass spectrometry (GC–MS) analysis was employed to trace the uptake and elimination of organophosphorus pesticides (OPPs) in two kinds of edible plants, cabbage (Brassica parachinensis) and aloe (Barbadensis). The metabolism of fenthion in aloe was also investigated by the liquid chromatography tandem mass spectrometry analysis (LC–MS/MS) to understand the fate of OPPs in living plants better. Transpiration stream concentration factor (TSCF) and depuration rate constants of the OPPs in living plants were obtained therein. The health risk of the OPPs treated aloe was estimated by the maximum residue limit (MRL) approach, and it revealed that the OPPs were rather safe for their fast degradable property. However, peak concentration of fenthion-sulfoxide was found to exceed the MRL and was higher than that of the parent fenthion, which indicated the potential risk of pesticide metabolites. This study highlighted the application of in vivo SPME for contaminant tracing in different living edible plants. The in vivo tracing method is very convenient and can provide more data to evaluate the risk of different pesticides, which are very important for the safety of agriculture production. - Highlights: • In vivo SPME was employed to sample organophosphorus pesticides in vegetables. • Uptake and elimination of OPPs were traced in cabbage and aloe. • In vivo tracing of fenthion demonstrated its metabolites could be rather dangerous. • The risks of OPPs were assessed based on the in vivo tracing data.

  13. Metagenomic Functional Potential Predicts Degradation Rates of a Model Organophosphorus Xenobiotic in Pesticide Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Thomas C. Jeffries

    2018-02-01

    Full Text Available Chemical contamination of natural and agricultural habitats is an increasing global problem and a major threat to sustainability and human health. Organophosphorus (OP compounds are one major class of contaminant and can undergo microbial degradation, however, no studies have applied system-wide ecogenomic tools to investigate OP degradation or use metagenomics to understand the underlying mechanisms of biodegradation in situ and predict degradation potential. Thus, there is a lack of knowledge regarding the functional genes and genomic potential underpinning degradation and community responses to contamination. Here we address this knowledge gap by performing shotgun sequencing of community DNA from agricultural soils with a history of pesticide usage and profiling shifts in functional genes and microbial taxa abundance. Our results showed two distinct groups of soils defined by differing functional and taxonomic profiles. Degradation assays suggested that these groups corresponded to the organophosphorus degradation potential of soils, with the fastest degrading community being defined by increases in transport and nutrient cycling pathways and enzymes potentially involved in phosphorus metabolism. This was against a backdrop of taxonomic community shifts potentially related to contamination adaptation and reflecting the legacy of exposure. Overall our results highlight the value of using holistic system-wide metagenomic approaches as a tool to predict microbial degradation in the context of the ecology of contaminated habitats.

  14. Separating esterase targets of organophosphorus compounds in the brain by preparative chromatography.

    Science.gov (United States)

    Mangas, I; Vilanova, E; Benabent, M; Estévez, J

    2014-02-10

    Low level exposure to organophosphorus esters (OPs) may cause long-term neurological effects and affect specific cognition domains in experimental animals and humans. Action on known targets cannot explain most of these effects by. Soluble carboxylesterases (EC 3.1.1.1) of chicken brain have been kinetically discriminated using paraoxon, mipafox and phenylmethyl sulfonylfluoride as inhibitors and phenyl valerate as a substrate. Three different enzymatic components were discriminated and called Eα, Eβ and Eγ. In this work, a fractionation procedure with various steps was developed using protein native separation methods by preparative HPLC. Gel permeation chromatography followed by ion exchange chromatography allowed enriched fractions with different kinetic behaviors. The soluble chicken brain fraction was fractionated, while total esterase activity, proteins and enzymatic components Eα, Eβ and Eγ were monitored in each subfraction. After the analysis, 13 fractions were pooled and conserved. Preincubation of the soluble chicken brain fraction of with the organophosphorus mipafox gave rise to a major change in the ion exchange chromatography profile, but not in the molecular exchanged chromatography profile, which suggest that mipafox permanently modifies the ionic properties of numerous proteins. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. Osmoregulatory function in ducks following ingestion of the organophosphorus insecticide fenthion

    Science.gov (United States)

    Rattner, B.A.; Fleming, W.J.; Murray, H.C.

    1983-01-01

    Salt gland function and osmoregulation in aquatic birds drinking hyperosmotic water has been suggested to be impaired by organophosphorus insecticides. To test this hypothesis, adult black ducks (Anas rubripes) were provided various regimens of fresh or salt (1.5% NaCl) water before, during, and after ingestion of mash containing 21 ppm fenthion. Ducks were bled by jugular venipuncture after I, 7. and 12 days of treatment, and were then killed. Brain and salt gland acetylcholinesterase activities were substantially inhibited (44-61% and 14-36%) by fenthion. However, salt gland weight and Na + -K + -ATPase activity, and plasma Na + , CI- , and osmolality, were uniformly elevated in all groups receiving salt water including those ingesting fenthion. In a second study, salt gland Na + -K + -ATPase activity in mallards (A. platyrhynchos) was not affected after in vitro incubation with either fenthion or fenthion oxon at concentrations ranging from 0.04 to 400 ?M, but was reduced in the presence of 40 and 400 ?M DDE (positive control). These findings suggest that environmentally realistic concentrations of organophosphorus insecticides do not markedly affect osmoregulatory function in adult black ducks.

  16. Organophosphorus and Organochlorine Pesticides Bioaccumulation by Eichhornia crassipes in Irrigation Canals in an Urban Agricultural System.

    Science.gov (United States)

    Mercado-Borrayo, B M; Cram Heydrich, Silke; Pérez, Irma Rosas; Hernández Quiroz, Manuel; De León Hill, Claudia Ponce

    2015-01-01

    A natural wetland in Mexico City Metropolitan Area is one of the main suppliers of crops and flowers, and in consequence its canals hold a high concentration of organochlorine (OC) and organophosphorus (OP) pesticides. There is also an extensive population of water hyacinth (Eichhornia crassipes), which is considered a plague; but literature suggests water hyacinth may be used as a phytoremediator. This study demonstrates bioaccumulation difference for the OC in vivo suggesting their bioaccumulation is ruled by their log K(ow), while all the OP showed bioaccumulation regardless of their log K(ow). The higher bioaccumulation factors (BAF) of the accumulated OC pesticides cannot be explained by their log K(ow), suggesting that the OC pesticides may also be transported passively into the plant. Translocation ratios showed that water hyacinth is an accumulating plant with phytoremediation potential for all organophosphorus pesticides studied and some organochlorine pesticides. An equation for free water surface wetlands with floating macrophytes, commonly used for the construction of water-cleaning wetlands, showed removal of the pesticides by the wetland with room for improvement with appropriate management.

  17. The analysis of common metabolites of organophosphorus pesticides in urine by gas chromatography/mass spectrometry

    International Nuclear Information System (INIS)

    Park, Seong Soo; Pyo, Hee Soo; Lee, Kang Jin; Park, Song Ja; Park, Taek Kyu

    1998-01-01

    Most organophosphorus pesticides may be metabolized to yield some common phosphates in human or in animals, and these metabolites may be used as the exposure biomarkers to pesticides. In this study, we developed the extraction method of four phosphate metabolites from the spiked human urine in high recovery by the solid phase extraction with a reverse-phase cartridge (cyclohexyl silica) followed by the elution with methanol. The extracted urinary metabolites were derivatized with hexamethyldisilazane/trimethyl-chlorosilane/pyridine (2:1:10, v/v/v) and identified by gas chromatography/mass spectrometry. Calibration curve obtained from each metabolite standard using by GC/MS/SIM has shown good linearity and detection limits of metabolites were the range of 0.05-0.1 μg/ml in urine. Phenthoate, one of the organophosphorus pesticides, was orally administrated to rats. Four metabolites were detected in the rat urine. The results of this study may be applied to development of exposure biomarkers for monitoring of environmental pollutants

  18. Organochlorine and organophosphorus pesticide residues in fodder and milk samples along Musi river belt, India

    Directory of Open Access Journals (Sweden)

    Korrapati Kotinagu

    2015-04-01

    Full Text Available Aim: The present study was conducted to find the organochlorine pesticide (OCP and organophosphorus pesticide (OPP residues in fodder and milk samples along Musi river belt, India. Materials and Methods: Fodder and milk samples collected from the six zones of Musi river belt, Hyderabad India were analyzed by gas chromatography with electron capture detector for OCP residues and pulsated flame photometric detector for the presence of OPP residues. Results: The gas chromatographic analysis of fodder samples of Zone 5 of Musi river showed the residues of dicofol at concentration of 0.07±0.0007 (0.071-0.077. Among organophosphorus compounds, dimetheoate was present in milk samples collected from Zone 6 at a level of 0.13±0.006 (0.111-0.167. The residues of OCPs, OPPs and cyclodies were below the detection limit in the remaining fodder and milk samples collected from Musi river belt in the present study. Conclusion: The results indicate that the pesticide residues in fodder and milk samples were well below the maximum residue level (MRL values, whereas dicofol in fodder and dimethoate in milk were slightly above the MRL values specified by EU and CODEX.

  19. Organochlorine and organophosphorus pesticide residues in fodder and milk samples along Musi river belt, India.

    Science.gov (United States)

    Kotinagu, Korrapati; Krishnaiah, Nelapati

    2015-04-01

    The present study was conducted to find the organochlorine pesticide (OCP) and organophosphorus pesticide (OPP) residues in fodder and milk samples along Musi river belt, India. Fodder and milk samples collected from the six zones of Musi river belt, Hyderabad India were analyzed by gas chromatography with electron capture detector for OCP residues and pulsated flame photometric detector for the presence of OPP residues. The gas chromatographic analysis of fodder samples of Zone 5 of Musi river showed the residues of dicofol at concentration of 0.07±0.0007 (0.071-0.077). Among organophosphorus compounds, dimetheoate was present in milk samples collected from Zone 6 at a level of 0.13±0.006 (0.111-0.167). The residues of OCPs, OPPs and cyclodies were below the detection limit in the remaining fodder and milk samples collected from Musi river belt in the present study. The results indicate that the pesticide residues in fodder and milk samples were well below the maximum residue level (MRL) values, whereas dicofol in fodder and dimethoate in milk were slightly above the MRL values specified by EU and CODEX.

  20. Intensification of Organophosphorus Hydrolase Synthesis by Using Substances with Gas-Transport Function

    Directory of Open Access Journals (Sweden)

    Olga Senko

    2017-12-01

    Full Text Available We have performed studies and comparative analysis of the biosynthesis characteristics of intracellular recombinant enzyme, such as hexahistidine-containing organophosphorus hydrolase (His6-OPH in Escherichia coli SG13009[pREP4] cells when various perfluorocarbon compounds (PFC were introduced into the medium for cell cultivation. The PFC were found to facilitate the biosynthesis of His6-OPH: increased levels of the total OPH-activity (up to 37% were measured upon introduction of 1,1,1,2,2,3,3,4,4,5,5,6,6,6-tetradecafluorohexane (PFH and 4,7,10,13,16,19,22,25,28,31-decaoxaperfluoro-5,8,11,14,17,18,21,24,27,30-decamethyl tetratriacontane (Polyether II into culture medium. We have demonstrated the possibility of effective and multiple (at least five-fold use of PFH for biosynthesis of intracellular recombinant protein His6-OPH, which catalyzes the hydrolysis of organophosphorus pesticides (OP, is widely used in agriculture and can be applied as new antidote for OP-detoxification in vivo. The multiple use of PFH was achieved through recycling of this substance: sediment of Escherichia coli SG13009[pREP4] cell biomass was collected at the end of each culture growing step and disintegrated with ultrasound, and obtained residue containing almost all of the initially introduced PFC was then added to the medium at the start of the following culture growing step.

  1. ACUTE EXOGENOUS INTOXICATIONS WITH ORGANOPHOSPHORUS PESTICIDES: DURATION OF THE HOSPITAL TREATMENT AND CLINICAL CRITERIA FOR PROGNOSIS

    Directory of Open Access Journals (Sweden)

    Petko Marinov

    2017-05-01

    Full Text Available Purpose: Several criteria have been suggested to estimate the intoxication severity, yet so far no system of clinical criteria has been developed to determine the duration of hospitalisation. The forecast is linked to the influence of the extended corrected QT interval and GCS (Glasgow Coma Scale on the frequency of the developing acute pulmonary insufficiency and lethality. The average duration of hospital treatment is also crucial. First of all, it is determined by the intoxication severity and lasts from 3 to 26 days. The aim of this study is to develop an individual forecast about the duration of hospitalisation for patients suffering from acute exogenous intoxication with organophosphorus pesticides (OPP. Materials/Methods: The subjects are 160 patients. We use statistical regression analysis to study the significance of 5 of the most typical clinical indicators of organophosphorus intoxication on the duration of hospitalisation: type of conscience, presence of spasms, pulmonary oedema, shock and multi-organ insufficiency syndrome (MOIS. To forecast the treatment length, we obtain simplified mathematical expressions in the form of score estimates. Results: The significance of the clinical indicators “MOIS”, “conscience” and “spasm” has been confirmed. A forecast matrix that gives the opportunity to forecast the personal duration of hospital treatment for each patient has been built.

  2. In vivo tracing of organophosphorus pesticides in cabbage (Brassica parachinensis) and aloe (Barbadensis)

    International Nuclear Information System (INIS)

    Qiu, Junlang; Chen, Guosheng; Zhou, Hong; Xu, Jianqiao; Wang, Fuxin; Zhu, Fang; Ouyang, Gangfeng

    2016-01-01

    In vivo solid-phase microextraction (SPME) sampling method coupled with gas chromatography–mass spectrometry (GC–MS) analysis was employed to trace the uptake and elimination of organophosphorus pesticides (OPPs) in two kinds of edible plants, cabbage (Brassica parachinensis) and aloe (Barbadensis). The metabolism of fenthion in aloe was also investigated by the liquid chromatography tandem mass spectrometry analysis (LC–MS/MS) to understand the fate of OPPs in living plants better. Transpiration stream concentration factor (TSCF) and depuration rate constants of the OPPs in living plants were obtained therein. The health risk of the OPPs treated aloe was estimated by the maximum residue limit (MRL) approach, and it revealed that the OPPs were rather safe for their fast degradable property. However, peak concentration of fenthion-sulfoxide was found to exceed the MRL and was higher than that of the parent fenthion, which indicated the potential risk of pesticide metabolites. This study highlighted the application of in vivo SPME for contaminant tracing in different living edible plants. The in vivo tracing method is very convenient and can provide more data to evaluate the risk of different pesticides, which are very important for the safety of agriculture production. - Highlights: • In vivo SPME was employed to sample organophosphorus pesticides in vegetables. • Uptake and elimination of OPPs were traced in cabbage and aloe. • In vivo tracing of fenthion demonstrated its metabolites could be rather dangerous. • The risks of OPPs were assessed based on the in vivo tracing data.

  3. Radiolytic investigations of solutions of organophosphorus compounds in cyclohexane and benzene

    International Nuclear Information System (INIS)

    Otrebski, W.

    1981-01-01

    Organphosphorus compounds are used in various branches of the chemical industry, but in many cases the reaction mechanisms are not well elucidated and less is known about the intermediates of organophosphines. In order to learn more about these rather complicated processes several organophosphorus compounds were used as model substrates in cyclohexane or benzene solution. The systems have been investigated applying the pulse radiolysis technique and steady-state irradiation methods. As representative solutes were chosen diphenylphosphinous chloride, diphenylmethylphosphine, and triphenylphosphine. By means of the pulse radiolysis it was possible to obtain spectroscopic and kinetic data for characterization of the various transients. The final radiolytic products have been analyzed following steady-state and multipulse radiolysis. Since some of the rate constants were not directly accessible by the applied kinetic method, they have been determined by simulation computation. Thereby the experimental data obtained by pulse radiolysis were used. Based on the kinetic, spectroscopic and computed data as well as on the identification of final products, it was possible to elucidate the reaction mechanism of the diphenylphosphinous chloride/cyclohexane system. As a main primary specie was identified the diphenylphoshorus radical. Its spectral and kinetic data have been determined. The reactions of diphenylmethylphosphine involve the same radical, but only to a lesser extent. The reactions of the primary radiolysis products with triphenylphosphine yield mainly adducts. The results represent a contribution in the field of reaction kinetics of organophosphorus compounds. (author)

  4. Bremsstrahlung and neutral currents

    International Nuclear Information System (INIS)

    Ellis, R.G.; McKellar, B.H.J.

    1979-01-01

    The utility of the bremsstrahlung process in detecting parity violations from V-A weak neutral current interference is analysed in two ways. Firstly, bremsstrahlung from polarized lepton-nucleus scattering has an asymmetry with respect to the polarization of the incident leptons, and secondly, bremsstrahlung from unpolarized lepton nucleus scattering has a small circular polarization. The magnitude of each effect is calculated. The ratio of the parity violating contribution and the parity conserving contribution to the cross section is shown to be a misleading measure of the utility of these experiments. A parameter, the figure of merit, is introduced and used to discuss the feasibility of possible experiments

  5. Plasma neutralizer for H- beams

    International Nuclear Information System (INIS)

    Grossman, M.W.

    1977-01-01

    Neutralization of H - beams by a hydrogen plasma is discussed. Optimum target thickness and maximum neutralization efficiency as a function of the fraction of the hydrogen target gas ionized is calculated for different H - beam energies. Also, the variation of neutralization efficiency with respect to target thickness for different H - beam energies is computed. The dispersion of the neutralized beam by a magnetic field for different energies and different values of B . z is found. Finally, a type of plasma jet is proposed, which may be suitable for a compact H - neutralizer

  6. Synthesis, Spectral, Thermogravimetric, XRD, Molecular Modelling and Potential Antibacterial Studies of Dimeric Complexes with Bis Bidentate ON–NO Donor Azo Dye Ligands

    Directory of Open Access Journals (Sweden)

    Bipin Bihari Mahapatra

    2013-01-01

    Full Text Available The dimeric complexes of Co(II, Ni(II, Cu(II, Zn(II, Cd(II, and Hg(II with two new symmetrical ON–NO donor bis bidentate (tetradentate azo dye ligands, LH2 = 4,4′-bis(4′-hydroxyquinolinolinylazodiphenylsulphone, and L′H2 = 4,4′-bis(acetoacetanilideazodiphenylsulphone have been synthesized. The metal complexes have been characterised by elemental analytical, conductance, magnetic susceptibility, IR, electronic spectra, ESR, NMR, thermogravimetry, X-ray diffraction (powder pattern spectra, and molecular modelling studies. The Co(II and Ni(II complexes are found to be octahedral, Cu(II complexes are distorted octahedral, and a tetrahedral stereochemistry has been assigned to Zn(II, Cd(II, and Hg(II complexes. The thermogravimetric study indicates that compounds are quite stable. The energy optimized structures are proposed using the semiempirical ZINDO/1 quantum mechanical calculations. The potential antibacterial study of the ligands and some metal complexes has been made with one gram positive bacteria Staphylococcus aureus and one gram negative bacteria E. coli which gives encouraging results. Both the Co(II complexes are found to possess monoclinic crystal system.

  7. Neutral helium beam probe

    Science.gov (United States)

    Karim, Rezwanul

    1999-10-01

    This article discusses the development of a code where diagnostic neutral helium beam can be used as a probe. The code solves numerically the evolution of the population densities of helium atoms at their several different energy levels as the beam propagates through the plasma. The collisional radiative model has been utilized in this numerical calculation. The spatial dependence of the metastable states of neutral helium atom, as obtained in this numerical analysis, offers a possible diagnostic tool for tokamak plasma. The spatial evolution for several hypothetical plasma conditions was tested. Simulation routines were also run with the plasma parameters (density and temperature profiles) similar to a shot in the Princeton beta experiment modified (PBX-M) tokamak and a shot in Tokamak Fusion Test Reactor tokamak. A comparison between the simulation result and the experimentally obtained data (for each of these two shots) is presented. A good correlation in such comparisons for a number of such shots can establish the accurateness and usefulness of this probe. The result can possibly be extended for other plasma machines and for various plasma conditions in those machines.

  8. Recent Developments in Organophosphorus Flame Retardants Containing P-C Bond and Their Applications

    Directory of Open Access Journals (Sweden)

    Sophie Wendels

    2017-07-01

    Full Text Available Organophosphorus compounds containing P-C bonds are increasingly developed as flame retardant additives due to their excellent thermal and hydrolytic stability and ease of synthesis. The latest development (since 2010 in organophosphorus flame retardants containing P-C bonds summarized in this review. In this review, we have broadly classified such phosphorus compounds based on the carbon unit linked to the phosphorus atom i.e., could be a part of either an aliphatic or an aromatic unit. We have only considered those published literature where a P-C bond was created as a part of synthetic strategy to make either an intermediate or a final organophosphorus compound with an aim to use it as a flame retardant. General synthetic strategies to create P-C bonds are briefly discussed. Most popular synthetic strategies used for developing P-C containing phosphorus based flame retardants include Michael addition, Michaelis–Arbuzov, Friedels–Crafts and Grignard reactions. In general, most flame retardant derivatives discussed in this review have been prepared via a one- to two-step synthetic strategy with relatively high yields greater than 80%. Specific examples of P-C containing flame retardants synthesized via suitable synthetic strategy and their applications on various polymer systems are described in detail. Aliphatic phosphorus compounds being liquids or low melting solids are generally applied in polymers via coatings (cellulose or are incorporated in the bulk of the polymers (epoxy, polyurethanes during their polymerization as reactive or non-reactive additives. Substituents on the P atoms and the chemistry of the polymer matrix greatly influence the flame retardant behavior of these compounds (condensed phase vs. the gas phase. Recently, aromatic DOPO based phosphinate flame retardants have been developed with relatively higher thermal stabilities (>250 °C. Such compounds have potential as flame retardants for high temperature processable

  9. Trace Detection of Organophosphorus Chemical Warfare Agents in Wastewater and Plants by Luminescent UIO-67(Hf) and Evaluating the Bioaccumulation of Organophosphorus Chemical Warfare Agents.

    Science.gov (United States)

    Lian, Xiao; Yan, Bing

    2018-05-02

    Organophosphorus chemical warfare agents (OPCWAs) are a group of organic pollutants characterized by high toxicity and chemical stability, and they are very difficult to be degraded. The trace quality of OPCWAs in water and food will cause great harm to the human body. Therefore, the detection of OPCWAs is a difficult challenge, which has become the research hotspot over the world. In this work, a Hf-based luminescent metal-organic framework (Eu@1) is prepared, and the reactivity of Hf 12 results in a methanephosphonic acid (MPA)-induced luminescence quenching and the charge transfer from MPA to Hf(IV) and generated exciplexes which are responsible for this quenching effect. The excellent performance of Eu@1 in the detection of MPA, with its finer selectivity, high sensitivity (LOD = 0.4 ppm), and large linear range (10 -7 to 10 -3 M), is encouraging for application in wastewater detection. Importantly, MPA is a pollutant that can be absorbed by plants and causes the bioaccumulation effect, and thus, the detection of MPA in real plant samples is a purposeful topic. Eu@1 also achieved satisfactory results in actual plant sample testing, and the bioaccumulation of MPA in onions, turnips, and cabbages is determined via our sensor. This fabricated detector provides a feasible path for the detection of ppm-level OPCWAs in a complex environment, which will help humans to avoid OPCWA-contaminated foods.

  10. An N-Linked Bidentate Phosphoramidite Ligand (N-Me-BIPAM for Rhodium-Catalyzed Asymmetric 1,4-Addition of Arylboronic Acids to α,β-Unsaturated Ketones

    Directory of Open Access Journals (Sweden)

    Norio Miyaura

    2012-12-01

    Full Text Available A new bidentate phosphoramidite (N-Me-BIPAM based on Shibasaki’s N-linked BINOL was synthesized. This ligand appears to be highly effective for rhodium-catalyzed asymmetric conjugated addition of arylboronic acids to α,β-unsaturated enones. The reaction of ortho-substituted arylboronic acid with acyclic and cyclic enones provides the corresponding products in good yields and enantioselectivities.

  11. Estimation of solubility of organo-phosphorus extractants by P determination using molybdovanadophosphoric acid method

    International Nuclear Information System (INIS)

    Gill, J.S.; Kotekar, M.K.; Singh, H.

    2005-01-01

    Solvent extraction processes have been found to be suitable for uranium recovery from phosphoric acid. Various extractants like di-2-ethyl hexylphosphoric acid (D2EHPA), di-nonylphenyl phosphoric acid (DNPPA) and synergistic agents like tri-butyl phosphate (TBP), tri-octyl phosphine oxide (TOPO) have been used in liquid-liquid extraction of uranium from phosphoric acid. Contents of these organo-phosphorus compounds in aqueous raffinates need estimation for process requirements. Solubility of Tri-butyl phosphate (TBP) and Di-2-ethylhexyl phosphoric acid (D2EHPA) extractants have been determined in different media of water, oxalic acid (0.6M) and sulphuric acid (3.75M) solutions. These compounds were estimated by determining their phosphorus (P) contents employing molybdovanadophosphoric acid method, after digesting and solubalizing them in nitric and perchloric acid. (author)

  12. Concentration of Organochlorine and Organophosphorus Pesticides in Different Molluscs from Tighra Reservoir, Gwalior, India.

    Science.gov (United States)

    Mamta; Rao, R J; Wani, Khursheed Ahmad

    2015-09-01

    Concentration of organochlorine and organophosphorus pesticides and their metabolites were determined in whole body homogenate of L. acuminata, I. exustus, V. dissimilis, V. bengalensis, from Tighra Reservoir during summer and post monsoon season using GC-MS technique. The different types of pesticides viz., HCB, heptachlor, aldrin, endosulfan, dieldrin, p,p-DDT, choloropyrifos, methyl parathion, dicholorovos, ethion, malathion, parathion were found in resident molluscs studied. Concentration of these pesticides varied independently during the summer and the post monsoon season at monitored sites. The study concluded that presence of pesticides in Tighra Reservoir is a major concern on public and ecosystem health and use of biopesticides in the adjacent area of Reservoir is highly recommended.

  13. Electrochemical process for the treatment of water contaminated with organophosphorus pesticides

    International Nuclear Information System (INIS)

    Samet, Youssef; Agengui, Lamia; Abdelhedi, Ridha

    2009-01-01

    The aim of this work is the use of electrochemical process for the total mineralization of water contaminated with organophosphorus pesticides like chloropyrifos. This pesticide is widely used both for agricultural pest control and in households as a termiticide. The process was studied under galvanostatic polarization mode using Ta/PbO 2 anodes and graphite carbon bar as cathode. The kinetic of organic matter decay and the mineralization efficiency were evaluated by means of the chemical oxygen demand (COD) measurement. The influence of the experimental parameters such as the initial concentration of chloropyrifos, temperature, and current density, on the electrochemical process performance was investigated. The experimental results showed that COD removal always follows a pseudo-first-order kinetics. The degradation rate increased drastically with increasing current density and temperature. However, it decreased with the increase of the initial pollutant concentrations. Very high organic matter degradation, approximately 90 pour cent in 10 h experiments, was obtained.

  14. Degradation kinetics of seven organophosphorus pesticides in milk during yoghurt processing

    Directory of Open Access Journals (Sweden)

    LI-YING BO

    2011-03-01

    Full Text Available Bovine milk spiked with seven organophosphorus pesticides, i.e., dimethoate, fenthion, malathion, methyl parathion, monocrotophos, phorate and trichlorphon, was fermented at 42 °C with commercial directed vat set (DVS starters to investigate the degradation kinetics of the pesticides during yoghurt processing. The spiked pesticides were extracted from the prepared samples with an organic solvent and analyzed by gas chromatography after purification. Based on published results that the degradation kinetics of pesticides is first order, the rate constant of degradation and the half live period of the pesticides were calculated. The results indicated that degradation of the pesticides in milk during yoghurt processing were enhanced by one or both starters, except for malathion, and the two commercial DVS starters had different influences on the degradation kinetics of the pesticides.

  15. Assessment of some biochemical and hematological parameters in treated with the organophosphorus insecticide cyanox

    International Nuclear Information System (INIS)

    ElMahdy, A.A.; Fayz, V.; Hassanin, M.M.

    2002-01-01

    The effect of single acute oral doses of 29 and 58 mg/kg of cyanox (an organophosphorus pesticide) on selected biochemical and hematological parameters in male rats were investigated. This compound inhibited blood acetylcholine esterase (AChE) significantly, over 72 hours post-treatment with the higher dose level. Serum alkaline phosphatase (ALP) was significantly depressed, 48 hr after treatment with 58 mg/kg. Serum bilirubin was elevated significantly after 48 and 24 hr of treatment with 29 and 58 mg/kg, respectively. Serum cholesterol increased significantly over 48 hr post-treatment with both dose levels.Hypertriglyceridemia was noticed only in the higher dose group. Serum total lipids were increased significantly at both dose levels. A slight treatment-related effect was observed in serum creatinine level. The hematological investigations revealed the occurrence of macrocytic normochromic anemia that was more evident in the lower dose group

  16. Influence of modifiers on the separation of dysprosium from neodymium using organophosphorus acid derivates

    Energy Technology Data Exchange (ETDEWEB)

    Elwert, Tobias; Schwarz, Sabrina; Goldmann, Daniel [TU Clausthal, Clausthal-Zellerfeld (Germany). Lehrstuhl fuer Rohstoffaufbereitung und Recycling

    2016-01-15

    The aim of this study was to investigate the applicability of three organophosphorus acid derivates (D2EHPA, EHEHPA and Cyanex 572) for the separation of terbium and dysprosium from praseodymium and neodymium from NdFeB magnets in chloride solution. A special focus was put on the effect of phase modifiers. The investigations revealed that all extractants show in general a similar extraction behavior but the extraction is shifted to higher pH values in the order D2EHPA < EHEHPA < Cyanex 572. Therefore, and due to higher realizable loadings, EHEHPA and Cyanex 572 are more suitable for the investigated separation problem than D2EHPA. Whereas EHEHPA requires 1-decanol as phase modifier, Cyanex 572 can be employed without modifier addition.

  17. Nicotine And The Risk Of Exposure To The Organophosphorus Insecticide Cyolane

    International Nuclear Information System (INIS)

    Hassanin M, M.; Bahig Mervat, E.

    1999-01-01

    The present investigation was undertaken to show the effect of repeated oral doses of nicotine (0.5 mg/kg) on rats pretreated or during treatment with cyolane (0.5 mg/kg 1/20 LD 5 0). The results revealed that exposure of smokers to organophosphorus pesticides exerted slight changes in GOT and GPT. Alkaline phosphatase was significantly increased to reach maximal (228.54 and 148.64%) after nicotine + cyolane and/or nicotine were given for a week to rats pretreated with cyolane for 2 weeks. Total protein, albumin and Albumin/Globulin (A/G) ratio were also affected. Administration of nicotine along with cyolane to rats showed a significant increase in cholesterol content compared to that of cyolane treated rats. Values of thyroxine (T 4 ) and triiodothyronine (T 3 ) also fluctuated

  18. Multipathway organophosphorus pesticide exposures of preschool children living in agricultural and nonagricultural communities

    International Nuclear Information System (INIS)

    Lu Chensheng; Kedan, Golan; Fisker-Andersen, Jennifer; Kissel, J.C.; Fenske, R.A.

    2004-01-01

    Environmental measurements of organophosphorus (OP) pesticides were conducted in the homes of 13 children, who lived either in the Seattle metropolitan area or in the agricultural region of Washington State, to ascertain exposure through multiple pathways. Each home was sampled for two 24-h periods during two seasons, summer and fall. Samples included 24-h indoor air, drinking water, soil, house dust, and hand and toy wipes and 24-h duplicate diets. At least one OP pesticide was found in each of the matrices sampled except for drinking water. Half of the indoor air samples contained detectable levels of chlorpyrifos or diazinon. Detectable levels of diazinon and azinphosmethyl in house dust were found in most of the agricultural homes, whereas only diazinon was found in the Seattle homes in the summer. Quantifiable chlorpyrifos and azinphosmethyl were found on either agricultural children's hands or their toys. These findings suggest different exposure pathways for children living in agricultural and nonagricultural regions

  19. Spectroscopy of neutral radium

    Energy Technology Data Exchange (ETDEWEB)

    Mol, Aran; De, Subhadeep; Jungmann, Klaus; Wilschut, Hans; Willmann, Lorenz [KVI, University of Groningen, Groningen (Netherlands)

    2008-07-01

    The heavy alkaline earth atoms radium is uniquely sensitive towards parity and time reversal symmetry violations due to a large enhancement of an intrinsic permanent electric dipole moment of the nucleous or the electron. Furthermore, radium is sensitive to atomic parity violation and the nuclear anapole moment. To prepare such experiments spectroscopy of relevant atomic states need to be done. At a later stage we will build a neutral atom trap for radium. We have built an atomic beam of the short lived isotope {sup 225}Ra with a flux of several 10{sup 4} atoms/sec. We are preparing the laser spectroscopy using this beam setup. In the preparation for efficient laser cooling and trapping we have successfully trapped barium, which is similar in it's requirements for laser cooling. The techniques which we have developed with barium can be used to trap rare radium isotopes. We report on the progress of the experiments.

  20. Engineering and introduction of de novo disulphide bridges in organophosphorus hydrolase enzyme for thermostability improvement.

    Science.gov (United States)

    Farnoosh, Gholamreza; Khajeh, Khosro; Latifi, Ali Mohammad; Aghamollaei, Hossein

    2016-12-01

    The organophosphorus hydrolase (OPH) has been used to degrade organophosphorus chemicals, as one of the most frequently used decontamination methods. Under chemical and thermal denaturing conditions, the enzyme has been shown to unfold. To utilize this enzyme in various applications, the thermal stability is of importance. The engineering of de novo disulphide bridges has been explored as a means to increase the thermal stability of enzymes in the rational method of protein engineering. In this study, Disulphide by Design software, homology modelling and molecular dynamics simulations were used to select appropriate amino acid pairs for the introduction of disulphide bridge to improve protein thermostability. The thermostability of the wild-type and three selected mutant enzymes were evaluated by half-life, delta G inactivation (ΔGi) and structural studies (fluorescence and far-UV CD analysis). Data analysis showed that half-life of A204C/T234C and T128C/E153C mutants were increased up to 4 and 24 min, respectively; however, for the G74C/A78C mutant, the half-life was decreased up to 9 min. For the T128C/E124C mutant, both thermal stability and Catalytic efficiency (kcat) were also increased. The half-life and ΔGi results were correlated to the obtained information from structural studies by circular dichroism (CD) spectrometry and extrinsic fluorescence experiments; as rigidity increased in A204C/T2234C and T128C/E153C mutants, half-life and ΔGi also increased. For G74C/A78C mutant, these parameters decreased due to its higher flexibility. The results were submitted a strong evidence for the possibility to improve the thermostability of OPH enzyme by introducing a disulphide bridge after bioinformatics design, even though this design would not be always successful.

  1. Net neutrality and audiovisual services

    OpenAIRE

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication networks: the control over the distribution of audiovisual services constitutes a vital part of the problem. In this contribution, the phenomenon of net neutrality is described first. Next, the European a...

  2. LADEE Neutral Mass Spectrometer Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains the data collected by the Neutral Mass Spectrometer (NMS) instrument aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE)...

  3. Phenomenology of neutral current interactions

    International Nuclear Information System (INIS)

    Sakurai, J.J.

    1978-01-01

    Neutral-current interactions are discussed within a rather general phenomenological framework without commitment to any particular theoretical model. Three points are kept in mind: what various experiments really measure; the performing of complete experiments to determine the neutral-current couplings; and the testing of models in an objective, emotionally uninvolved manner. The following topics are considered: neutrino-electron scattering, hadronic currents and models, neutrino-induced inclusive hadronic reactions, neutrino-induced exclusive hadronic reactions, and neutral-current phenomena without neutrinos. In conclusion, what has actually been learned about neutral-current interactions is summarized. 9 figures, 2 tables

  4. On becoming neutral: effects of experimental neutralizing reconsidered.

    Science.gov (United States)

    van den Hout, M; van Pol, M; Peters, M

    2001-12-01

    Behaviour Research and Therapy 34 (1996) 889-898 found that writing out a negative thought produced anxiety and an urge to neutralize the thought, that instructing participants to neutralize the thought reduced anxiety/neutralization urge in the short run (i.e. within 2 min), but that in the control group 20 min without instruction was attended by the same reduction in anxiety/urge to neutralize ("natural decay"). The observations were made with pariticipants who scored high on "thought action fusion" and the experiment was set up as exerimental model of obsessions. We repeated the study with participants that were not selected on thought action fusion. All the findings reported by Behaviour Research and Therapy 34 (1996) 889-898 were replicated. Correlational analysis indicated that the strength of the effect was not related to scores on scales measuring "thought action fusion". Behaviour Research and Therapy 34 (1996) 889-898 did not assess whether non-neutralizing was followed by immediate reductions in distress. We did assess this and found that the larger part of the immediate reduction of distress after neutralization also occurs when no neutralization instruction is given. The effects of neutralization instructions in the present type of experiment are considerably less powerful than suggested earlier.

  5. Divergent effects of postmortem ambient temperature on organophosphorus- and carbamate-inhibited brain cholinesterase activity in birds

    Science.gov (United States)

    Hill, E.F.

    1989-01-01

    Time- and temperature-dependent postmortem changes in inhibited brain cholinesterase (ChE) activity may confound diagnosis of field poisoning of wildlife by anticholinesterase pesticide. Carbamate-inhibited ChE activity may return to normal within 1 to 2 days of exposure of intact carcass to moderate ambient temperature (18-32C). Organophosphorus-inhibited ChE activity becomes more depressed over the same time. Uninhibited ChE activity was resilient to above freezing temperature to 32C for 1 day and 25C for 3 days. Carbamate- and organophosphorus-inhibited ChE can be separated by incubation of homogenate for 1 hour at physiological temperatures; carbamylated ChE can be readily reactivated while phosphorylated ChE cannot.

  6. Increased fetal endocardial echogenicity mimicking endocardial fibroelastosis following maternal organophosphorus poisoning and its complete regression in utero

    International Nuclear Information System (INIS)

    Balakumar, Karippaliyil; Misha, Kannan; Milind, Karippaliyil

    2013-01-01

    Fetal endocardial fibroelastosis (EFE) has been diagnosed by antenatal ultrasonography in the past few years. A typical case of isolated endocardial fibroelastosis is illustrated here, in a fetus of 22 weeks of gestational age exposed to maternal organophosphorus poisoning at 20 weeks. No other structural cardiac or other systemic anomalies were detected in this fetus. The abnormal fetal echocardiographic features mimicking endocardial fibroelastosis completely regressed after 14 weeks and a normal full-term baby was delivered. Postnatal echocardiogram showed normal cardiac parameters. The diagnostic features mimicking EFE following maternal organophosphorus poisoning at 20 weeks of gestational age and the subsequent complete reversal of these changes after 14 weeks of diagnosis are reported for the first time in the literature

  7. CO2-neutral fuels

    Directory of Open Access Journals (Sweden)

    Goede A. P. H.

    2015-01-01

    Full Text Available The need for storage of renewable energy (RE generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel

  8. Expression of organophosphorus-degradation gene ( opd) in aggregating and non-aggregating filamentous nitrogen-fixing cyanobacteria

    Science.gov (United States)

    Li, Qiong; Tang, Qing; Xu, Xudong; Gao, Hong

    2010-11-01

    Genetic engineering in filamentous N2-fixing cyanobacteria usually involves Anabaena sp. PCC 7120 and several other non-aggregating species. Mass culture and harvest of such species are more energy consuming relative to aggregating species. To establish a gene transfer system for aggregating species, we tested many species of Anabaena and Nostoc, and identified Nostoc muscorum FACHB244 as a species that can be genetically manipulated using the conjugative gene transfer system. To promote biodegradation of organophosphorus pollutants in aquatic environments, we introduced a plasmid containing the organophosphorus-degradation gene ( opd) into Anabaena sp. PCC 7120 and Nostoc muscorum FACHB244 by conjugation. The opd gene was driven by a strong promoter, P psbA . From both species, we obtained transgenic strains having organophosphorus-degradation activities. At 25°C, the whole-cell activities of the transgenic Anabaena and Nostoc strains were 0.163±0.001 and 0.289±0.042 unit/μg Chl a, respectively. However, most colonies resulting from the gene transfer showed no activity. PCR and DNA sequencing revealed deletions or rearrangements in the plasmid in some of the colonies. Expression of the green fluorescent protein gene from the same promoter in Anabaena sp. PCC 7120 showed similar results. These results suggest that there is the potential to promote the degradation of organophosphorus pollutants with transgenic cyanobacteria and that selection of high-expression transgenic colonies is important for genetic engineering of Anabaena and Nostoc species. For the first time, we established a gene transfer and expression system in an aggregating filamentous N2-fixing cyanobacterium. The genetic manipulation system of Nostoc muscorum FACHB244 could be utilized in the elimination of pollutants and large-scale production of valuable proteins or metabolites.

  9. Electromagnetic radiation optimum neutralizer

    International Nuclear Information System (INIS)

    Smirnov, Igor

    2002-01-01

    This particular article relates to subtle electrical effects, and provides some evidence of a fundamental nature on how subtle low frequency electromagnetic fields might be utilized to protect human body against harmful effects of high frequencies electromagnetic radiation. I have focused my efforts on definite polar polymer compound named EMRON which is patented in the USA. This polar polymer compound can be excited by external high frequencies electromagnetic fields to generate subtle low frequency oscillations that are beneficial for cellular life structures. This concept is based on the possibility of existence of resonance phenomenon between polar polymers and biopolymers such as proteins, nucleic acids, lipids, etc. Low frequency patterns generated by defined polar polymer compound can interact with biostructures and transmit the signals that support and improve cellular functions in the body. The mechanism of this process was confirmed by number of studies. The animal (including human) brain is affected by electromagnetic waves to the extent that production of Alpha or Theta waves can be directly induced into brain by carrying an ELF (extremely low frequency, 5-12 Hz) signal on a microwave carrier frequency. EMRON does not reduce the power of electromagnetic fields. It 'shields' the cellular structures of the body against the harmful effects of EMR. The radiation is still entering the body but the neutralizing effect of EMRON renders the radiation harmless

  10. Is science metaphysically neutral?

    Science.gov (United States)

    Fry, Iris

    2012-09-01

    This paper challenges the claim that science is metaphysically neutral upheld by contenders of the separation of peacefully co-existent science and religion and by evolutionary theists. True, naturalistic metaphysical claims can neither be refuted nor proved and are thus distinct from empirical hypotheses. However, metaphysical assumptions not only regulate the theoretical and empirical study of nature, but are increasingly supported by the growing empirical body of science. This historically evolving interaction has contributed to the development of a naturalistic worldview that renounces the necessity of a transcendent god and of purposeful design. The thesis presented here differs not only from the claims of the "separatists" and of evolutionary theists. In pointing to the metaphysical aspects of science, I also criticize the failure of some evolutionary naturalists to distinguish between empirical and metaphysical contentions. Most important, based on the examination of science suggested here, creationists' false accusation that science is only a naturalistic dogma is refuted. Finally, the difficulties involved in the position endorsed here for the public support of evolution are acknowledged, taking into account the high religious profile of the American society and the social and political context in the US and in other countries. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. [Determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection].

    Science.gov (United States)

    Luo, Xiao-Fei; Yang, Yuan; Sun, Cheng-Jun

    2012-01-01

    To develop a method for the simultaneous determination of 44 organophosphorus pesticides in food by SPE disk extraction-capillary gas chromatography with pulsed flame photometric detection. Organophosphorus pesticides in food were extracted ultrasonically with water. Then the extract was cleaned-up with SPE disk and eluted with ethyl acetate. Finally the eluent was condensed to 1mL under N2 at 55 degrees C. Gas chromatography was applied for quantitative detection of the organophosphorus pesticides in the sample. The linear range of the method for all the pesticides were in the range of 0.01-0.5 mg/kg with correlation coefficients of 0.992-1.000. The detection limits of the method were in the range of 0.0005-0.01 mg/kg. The recoveries for most pesticides were 60%-120% with relative standard deviations of less than 15%. The method is simple, sensitive, environmentally friendly and suitable for the determination of organophosphorous pesticides in food.

  12. Identification and isolation of bacteria containing OPH enzyme for biodegradation of organophosphorus pesticide diazinon from contaminated agricultural soil

    Directory of Open Access Journals (Sweden)

    Sara Mobarakpoor

    2015-04-01

    Full Text Available Background: Organophosphorus insecticide diazinon has been widely used in agriculture and has the ability to transfer and accumulate in soil, water and animal tissues, and to induce toxicity in plants, animals and humans. In humans, diazinon inhibits nerve transmission by inactivating acetylcholinesterase enzyme. The present study was carried out to identify bacteria containing OPH enzyme for biodegradation of diazinon from contaminated agricultural soil. Methods: In this study, 8 contaminated agricultural soil samples that were exposed to pesticides, especially diazinon in the last two decades, were collected from the farms of Hamedan province. After preparing the media, for isolation of several bacterial strains containing OPH enzyme that are capable of biodegrading organophosphorus pesticides by diazinon enzymatic hydrolysis, bacterial genomic DNA extraction, plasmid product sequencing, phylogenetic sequence processing and phylogenetic tree drawing were carried out. Results: Eight bacterial strains, capable of secreting OPH enzyme, were isolated from soil samples, one of which named BS-1 with 86% similarity to Bacillus safensis displayed the highest organophosphate-hydrolyzing capability and can be used as a source of carbon and phosphorus. Conclusion: It can be concluded that the isolated bacterial strain identified in this study with OPH enzyme secretion has the potential for biodegradation of organophosphorus pesticides, especially diazinon in invitro conditions. Also, further studies such as the environmental stability and interaction, production strategies, safety, cost-benefit, environmental destructive parameters, and, toxicological, genetic and biochemical aspects are recommended prior to the application of bacterial strains in the field-scale bioremediation.

  13. The merits of neutral theory

    NARCIS (Netherlands)

    Alonso, D.; Etienne, R.S.; McKane, A.J.

    2006-01-01

    Hubbell's neutral theory of biodiversity has challenged the classic niche-based view of ecological community structure. Although there have been many attempts to falsify Hubbell's theory, we argue that falsification should not lead to rejection, because there is more to the theory than neutrality

  14. Neutral evolution of mutational robustness

    NARCIS (Netherlands)

    Nimwegen, Erik van; Crutchfield, James P.; Huynen, Martijn

    1999-01-01

    We introduce and analyze a general model of a population evolving over a network of selectively neutral genotypes. We show that the population s limit distribution on the neutral network is solely determined by the network topology and given by the principal eigenvector of the network

  15. Net neutrality and audiovisual services

    NARCIS (Netherlands)

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication

  16. Actinide extractants for the nuclear industry of the future

    International Nuclear Information System (INIS)

    Musikas, C.; Morisseau, J.C.; Hoel, P.; Guillaume, B.

    1987-06-01

    Non organo-phosphorus extractants properties regarding the extractions of actinides in nuclear fuels reprocessing are presented. N,N-dialkylamides are proposed as alternatives to TBP.N,N'-tetraalkylamides or pentaalkyl propane diamides properties are reported. They show that those bidentate extractants are alternatives to bidentate organophosphorus extractants for actinides (III) extraction from concentrated nitric acid. 11 figs, 15 refs

  17. STUDY OF CLINICAL PROFILE AND OUTCOME OF ORGANOPHOSPHORUS POISONING IN RELATION TO PSEUDOCHOLINESTERASE LEVEL

    Directory of Open Access Journals (Sweden)

    Rajyalakshmi

    2017-11-01

    Full Text Available BACKGROUND The state of Andhra Pradesh, particularly the coastal districts are an area of intensive agricultural production. Pesticide use is high, and the state has one of the highest reported rates of pesticide poisoning in India. The resources for treating this number of cases in government hospitals are limited and likely to have an impact on patient outcome. The present study was carried out in one such hospital of the state. Amongst these pesticides, insecticides constitute an important group, and organophosphorus compounds are possibly the insecticides widely used, all over the world. MATERIALS AND METHODS Hundred patients of pesticide poisoning admitted into the medical ward of Government General Hospital, Kakinada during the period of August 2010 to July 2014 were studied. Detailed history was taken in each case from patient and attendants. A meticulous physical examination was done on each of them at the time of admission. The diagnosis of poisoning was suspected from the characteristic garlic and kerosene like odour, characteristic signs and symptoms of poisoning and corroborative evidence collected in the form of packets or containers obtained from the site by family members or bystanders. RESULTS Out of the 14 patients who died, 11 died due to organophosphate poisoning, 2 patients died due to organochlorine poisoning and 1 patient died due to herbicide poisoning. Out of the 11 patients who expired due to organophosphate poisoning, 10 patients had pseudocholinesterase value ≤1 unit/mL. The remaining one (1 patient who died, had a pseudocholinesterase value of 2.2 units/mL. Of the 11 patients who died due to organophosphate poisoning, Monocrotophos recorded highest number of deaths (6 cases, followed by dimethoate, which was responsible for 2 deaths. Methyl parathion, Profenophos and Chlorpyriphos caused 1 death each. An organochlorine compound, Endosulfan caused 2 deaths. Paraquat, a herbicide was responsible for 1 death

  18. [Research on rapid and quantitative detection method for organophosphorus pesticide residue].

    Science.gov (United States)

    Sun, Yuan-Xin; Chen, Bing-Tai; Yi, Sen; Sun, Ming

    2014-05-01

    The methods of physical-chemical inspection is adopted in the traditional pesticide residue detection, which require a lot of pretreatment processes, are time-consuming and complicated. In the present study, the authors take chlorpyrifos applied widely in the present agricultural field as the research object and propose a rapid and quantitative detection method for organophosphorus pesticide residues. At first, according to the chemical characteristics of chlorpyrifos and comprehensive chromogenic effect of several colorimetric reagents and secondary pollution, the pretreatment of the scheme of chromogenic reaction of chlorpyrifos with resorcin in a weak alkaline environment was determined. Secondly, by analyzing Uv-Vis spectrum data of chlorpyrifos samples whose content were between 0. 5 and 400 mg kg-1, it was confirmed that the characteristic information after the color reaction mainly was concentrated among 360 approximately 400 nm. Thirdly, the full spectrum forecasting model was established based on the partial least squares, whose correlation coefficient of calibration was 0. 999 6, correlation coefficient of prediction reached 0. 995 6, standard deviation of calibration (RMSEC) was 2. 814 7 mg kg-1, and standard deviation of verification (RMSEP) was 8. 012 4 mg kg-1. Fourthly, the wavelengths whose center wavelength is 400 nm was extracted as characteristic region to build a forecasting model, whose correlation coefficient of calibration was 0. 999 6, correlation coefficient of prediction reached 0. 999 3, standard deviation of calibration (RMSEC) was 2. 566 7 mg kg-1 , standard deviation of verification (RMSEP) was 4. 886 6 mg kg-1, respectively. At last, by analyzing the near infrared spectrum data of chlorpyrifos samples with contents between 0. 5 and 16 mg kg-1, the authors found that although the characteristics of the chromogenic functional group are not obvious, the change of absorption peaks of resorcin itself in the neighborhood of 5 200 cm

  19. Is an inequality-neutral flat tax reform really neutral?

    OpenAIRE

    Juan Prieto Rodríguez; Juan Gabriel Rodríguez; Rafael Salas

    2004-01-01

    . Let us assume a revenue- and inequality-neutral flat tax reform shifting from a graduated-rate tax. Is this reform really neutral in terms of the income distribution? Traditionally, there has been a bias toward the inequality analysis, forgetting other relevant aspects of the income distribution. This kind of reforms implies a set of composite transfers, both progressive and regressive, even though inequality remains unchanged. This paper shows that polarization is a useful tool for charact...

  20. Gastric Lavage in Acute Organophosphorus Pesticide poisoning (GLAOP – a randomised controlled trial of multiple vs. single gastric lavage in unselected acute organophosphorus pesticide poisoning

    Directory of Open Access Journals (Sweden)

    Cao YuPing

    2006-10-01

    Full Text Available Abstract Background Organophosphorus (OP pesticide poisoning is the most common form of pesticide poisoning in many Asian countries. Guidelines in western countries for management of poisoning indicate that gastric lavage should be performed only if two criteria are met: within one hour of poison ingestion and substantial ingested amount. But the evidence on which these guidelines are based is from medicine overdoses in developed countries and may be irrelevant to OP poisoning in Asia. Chinese clinical experience suggests that OP remains in the stomach for several hours or even days after ingestion. Thus, there may be reasons for doing single or multiple gastric lavages for OP poisoning. There have been no randomised controlled trials (RCTs to assess this practice of multiple lavages. Since it is currently standard therapy in China, we cannot perform a RCT of no lavage vs. a single lavage vs. multiple lavages. We will compare a single gastric lavage with three gastric lavages as the first stage to assess the role of gastric lavage in OP poisoning. Methods/Design We have designed an RCT assessing the effectiveness of multiple gastric lavages in adult OP self-poisoning patients admitted to three Chinese hospitals within 12 hrs of ingestion. Patients will be randomised to standard treatment plus either a single gastric lavage on admission or three gastric lavages at four hour intervals. The primary outcome is in-hospital mortality. Analysis will be on an intention-to-treat basis. On the basis of the historical incidence of OP at the study sites, we expect to enroll 908 patients over three years. This projected sample size provides sufficient power to evaluate the death rate; and a variety of other exposure and outcome variables, including particular OPs and ingestion time. Changes of OP level will be analyzed in order to provide some toxic kinetic data. Discussion the GLAOP study is a novel, prospective cohort study that will explore to the toxic

  1. Neutrality Versus Materiality: A Thermodynamic Theory of Neutral Surfaces

    Directory of Open Access Journals (Sweden)

    Rémi Tailleux

    2016-09-01

    Full Text Available In this paper, a theory for constructing quasi-neutral density variables γ directly in thermodynamic space is formulated, which is based on minimising the absolute value of a purely thermodynamic quantity J n . Physically, J n has a dual dynamic/thermodynamic interpretation as the quantity controlling the energy cost of adiabatic and isohaline parcel exchanges on material surfaces, as well as the dependence of in-situ density on spiciness, in a description of water masses based on γ, spiciness and pressure. Mathematically, minimising | J n | in thermodynamic space is showed to be equivalent to maximising neutrality in physical space. The physics of epineutral dispersion is also reviewed and discussed. It is argued, in particular, that epineutral dispersion is best understood as the aggregate effect of many individual non-neutral stirring events (being understood here as adiabatic and isohaline events with non-zero buoyancy, so that it is only the net displacement aggregated over many events that is approximately neutral. This new view resolves an apparent paradox between the focus in neutral density theory on zero-buoyancy motions and the overwhelming evidence that lateral dispersion in the ocean is primarily caused by non-zero buoyancy processes such as tides, residual currents and sheared internal waves. The efficiency by which a physical process contributes to lateral dispersion can be characterised by its energy signature, with those processes releasing available potential energy (negative energy cost being more efficient than purely neutral processes with zero energy cost. The latter mechanism occurs in the wedge of instability, and its source of energy is the coupling between baroclinicity, thermobaricity, and density compensated temperature/salinity anomalies. Such a mechanism, which can only exist in a salty ocean, is speculated to be important for dissipating spiciness anomalies and neutral helicity. The paper also discusses potential

  2. Net Neutrality: Background and Issues

    National Research Council Canada - National Science Library

    Gilroy, Angele A

    2006-01-01

    .... The move to place restrictions on the owners of the networks that compose and provide access to the Internet, to ensure equal access and nondiscriminatory treatment, is referred to as "net neutrality...

  3. Weak neutral-current interactions

    International Nuclear Information System (INIS)

    Barnett, R.M.

    1978-08-01

    The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z 0 boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references

  4. Organophosphorus flame retardants in mangrove sediments from the Pearl River Estuary, South China.

    Science.gov (United States)

    Hu, Yong-Xia; Sun, Yu-Xin; Li, Xiao; Xu, Wei-Hai; Zhang, Ying; Luo, Xiao-Jun; Dai, Shou-Hui; Xu, Xiang-Rong; Mai, Bi-Xian

    2017-08-01

    Forty-eight surface sediments were collected from three mangrove wetlands in the Pearl River Estuary (PRE) of South China to investigate the distribution of organophosphorus flame retardants (OPFRs) and the relationship between OPFRs and microbial community structure determined by phospholipid fatty acid. Concentrations of ΣOPFRs in mangrove sediments of the PRE ranged from 13.2 to 377.1 ng g -1 dry weight. Levels of ΣOPFRs in mangrove sediments from Shenzhen and Guangzhou were significantly higher than those from Zhuhai, indicating that OPFRs were linked to industrialization and urbanization. Tris(chloropropyl)phosphate was the predominant profile of OPFRs in mangrove sediments from Shenzhen (38.9%) and Guangzhou (35.0%), while the composition profile of OPFRs in mangrove sediments from Zhuhai was dominated by tris(2-chloroethyl) phosphate (25.5%). The mass inventories of OPFRs in the mangrove sediments of Guangzhou, Zhuhai and Shenzhen were 439.5, 133.5 and 662.3 ng cm -2 , respectively. Redundancy analysis revealed that OPFRs induced a shift in the structure of mangrove sediment microbial community and the variations were significantly correlated with tris(1,3-dichloro-2-propyl)phosphate and tris(2-butoxyethyl) phosphate. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Sensitive spectrophotometric methods for determination of some organophosphorus pesticides in vegetable samples

    Directory of Open Access Journals (Sweden)

    MAGDA A. AKL

    2010-03-01

    Full Text Available Three rapid, simple, reproducible and sensitive spectrophotometric methods (A, B and C are described for the determination of two organophosphorus pesticides, (malathion and dimethoate in formulations and vegetable samples. The methods A and B involve the addition of an excess of Ce4+ into sulphuric acid medium and the determination of the unreacted oxidant by decreasing the red color of chromotrope 2R (C2R at a suitable lmax = 528 nm for method A, or a decrease in the orange pink color of rhodamine 6G (Rh6G at a suitable lmax = = 525 nm. The method C is based on the oxidation of malathion or dimethoate with the slight excess of N-bromosuccinimide (NBS and the determination of unreacted oxidant by reacting it with amaranth dye (AM in hydrochloric acid medium at a suitable lmax = 520 nm. A regression analysis of Beer-Lambert plots showed a good correlation in the concentration range of 0.1-4.2 μg mL−1. The apparent molar absorptivity, Sandell sensitivity, the detection and quantification limits were calculated. For more accurate analysis, Ringbom optimum concentration ranges are 0.25-4.0 μg mL−1. The developed methods were successfully applied to the determination of malathion, and dimethoate in their formulations and environmental vegetable samples.

  6. Partitioning of organophosphorus pesticides into phosphatidylcholine small unilamellar vesicles studied by second-derivative spectrophotometry.

    Science.gov (United States)

    Takegami, Shigehiko; Kitamura, Keisuke; Ohsugi, Mayuko; Ito, Aya; Kitade, Tatsuya

    2015-06-15

    In order to quantitatively examine the lipophilicity of the widely used organophosphorus pesticides (OPs) chlorfenvinphos (CFVP), chlorpyrifos-methyl (CPFM), diazinon (DZN), fenitrothion (FNT), fenthion (FT), isofenphos (IFP), profenofos (PFF) and pyraclofos (PCF), their partition coefficient (Kp) values between phosphatidylcholine (PC) small unilamellar vesicles (SUVs) and water (liposome-water system) were determined by second-derivative spectrophotometry. The second-derivative spectra of these OPs in the presence of PC SUV showed a bathochromic shift according to the increase in PC concentration and distinct derivative isosbestic points, demonstrating the complete elimination of the residual background signal effects that were observed in the absorption spectra. The Kp values were calculated from the second-derivative intensity change induced by addition of PC SUV and obtained with a good precision of R.S.D. below 10%. The Kp values were in the order of CPFM>FT>PFF>PCF>IFP>CFVP>FNT⩾DZN and did not show a linear correlation relationship with the reported partition coefficients obtained using an n-octanol-water system (R(2)=0.530). Also, the results quantitatively clarified the effect of chemical-group substitution in OPs on their lipophilicity. Since the partition coefficient for the liposome-water system is more effective for modeling the quantitative structure-activity relationship than that for the n-octanol-water system, the obtained results are toxicologically important for estimating the accumulation of these OPs in human cell membranes. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Susceptibility of nine organophosphorus pesticides in skimmed milk towards inoculated lactic acid bacteria and yogurt starters.

    Science.gov (United States)

    Zhou, Xin-Wei; Zhao, Xin-Huai

    2015-01-01

    Previous research has shown that fresh milk might be polluted by some organophosphorus pesticides (OPPs). In this study the dissipation of nine OPPs, namely chlorpyrifos, chlorpyrifos-methyl, diazinon, dichlorvos, fenthion, malathion, phorate, pirimiphos-methyl and trichlorphon, in skimmed milk was investigated to clarify their susceptibility towards lactic acid bacteria (LAB) and yogurt starters. Skimmed milk was spiked with nine OPPs, inoculated with five strains of LAB and two commercial yogurt starters at 42 °C for 24 and 5 h respectively and subjected to quantitative OPP analysis by gas chromatography. Degradation kinetic constants of these OPPs were calculated based on a first-order reaction model. OPP dissipation in the milk was enhanced by the inoculated strains and starters, resulting in OPP concentrations decreasing by 7.0-64.6 and 7.4-19.2% respectively. Totally, the nine OPPs were more susceptible to Lactobacillus bulgaricus, as it enhanced their degradation rate constants by 18.3-133.3%. Higher phosphatase production of the assayed stains was observed to bring about greater OPP degradation in the milk. Both LAB and yogurt starters could enhance OPP dissipation in skimmed milk, with the nine OPPs studied having different susceptibilities towards them. Phosphatase was a key factor governing OPP dissipation. The LAB of higher phosphatase production have more potential to decrease OPPs in fermented foods. © 2014 Society of Chemical Industry.

  8. A portable liquid crystal-based polarized light system for the detection of organophosphorus nerve gas

    Science.gov (United States)

    He, Feng Jie; Liu, Hui Long; Chen, Long Cong; Xiong, Xing Liang

    2018-03-01

    Liquid crystal (LC)-based sensors have the advantageous properties of being fast, sensitive, and label-free, the results of which can be accessed directly only through the naked eye. However, the inherent disadvantages possessed by LC sensors, such as relying heavily on polarizing microscopes and the difficulty to quantify, have limited the possibility of field applications. Herein, we have addressed these issues by constructing a portable polarized detection system with constant temperature control. This system is mainly composed of four parts: the LC cell, the optics unit, the automatic temperature control unit, and the image processing unit. The LC cell was based on the ordering transitions of LCs in the presence of analytes. The optics unit based on the imaging principle of LCs was designed to substitute the polarizing microscope for the real-time observation. The image processing unit is expected to quantify the concentration of analytes. The results have shown that the presented system can detect dimethyl methyl phosphonate (a stimulant for organophosphorus nerve gas) within 25 s, and the limit of detection is about 10 ppb. In all, our portable system has potential in field applications.

  9. Determination of organophosphorus pesticides using molecularly imprinted polymer solid phase extraction

    International Nuclear Information System (INIS)

    Mohd Marsin Sanagi; Syairah Salleh; Wan Aini Wan Ibrahim

    2011-01-01

    Molecularly imprinted polymer solid phase extraction (MIP-SPE) method has been developed for the determination of organophosphorus pesticides (OPPs) in water samples. The MIP was prepared by thermo-polymerization method using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as crosslinker, acetonitrile as porogenic solvent and quinalphos as the template molecule. The three OPPs (diazinon, quinalphos and chloropyrifos) were selected as target analytes as they are widely used in agriculture sector. Various parameters affecting the extraction efficiency of the imprinted polymers have been evaluated to optimize the selective preconcentration of OPPs from aqueous samples. The characteristics of the MIP-SPE method were validated by high performance liquid chromatography (HPLC). The accuracy and selectivity of the MIP-SPE process developed were verified using non-imprinted polymer solid phase extraction (NIP-SPE) and a commercial C 18 -SPE was used for comparison. The recoveries of the target analytes obtained using the MIPs as the solid phase sorbent ranged from 83% to 98% (RSDs 1.05 - 1.98 %; n=3) for water sample. The developed MIP-SPE method demonstrates that it could be applied for the determination of OPPs in water samples. (author)

  10. Competitive immunochromatographic assay for the detection of the organophosphorus pesticide chlorpyrifos

    Science.gov (United States)

    Kim, Young Ah; Lee, Eun-Hye; Kim, Kwang-Ok; Lee, Yong Tae; Hammock, Bruce D.; Lee, Hye-Sung

    2014-01-01

    An immunochromatographic assay (ICA) based on competitive antigen-coated format using colloidal gold as the label was developed for the detection of the organophosphorus insecticide chlorpyrifos. The ICA test strip consisted of a membrane with a detection zone, a sample pad and an absorbent pad. The membrane was separately coated with chlorpyrifos hapten-OVA conjugate (test line) and anti-mouse IgG (control line). Based on the fact that the competition is between the migrating analyte in the sample and the analyte hapten immobilized on the test strip for the binding sites of the antibody-colloidal gold (Ab-CG) conjugate migrating on the test strip, this study suggests that the relative migration speed between the two migrating substances is a critically important factor for the sensitive detection by competitive ICA. This criterion was utilized for the confirmation of appropriateness of a nitrocellulose (NC) membrane for chlorpyrifos ICA. The detection limit of the ICA for chlorpyrifos standard and chlorpyrifos spiked into agricultural samples were 10 and 50 ng mL−1, respectively. The assay time for the ICA test was less than 10 min, suitable for rapid on-site testing of chlorpyrifos. PMID:21504817

  11. Improvement of Some Biochemical Activities of Rats Treated with The Organophosphorus Insecticide Cytrolane Using Soyabean

    International Nuclear Information System (INIS)

    Abdel-Fattah, A.M.; Elmahdy, A.A.

    2005-01-01

    This Study aims to evaluate the role of soyabean diet in improvement of some biochemical activities of female rats received daily oral dose 0.89 mg/kg (1/10 LD 50 )of cytrolane as organophosphorus insecticide on some biochemical activities in female rats for ten consecutive days. Prior pesticide administration, female rats received soyabean at dose 58 g/kg body weight for 2 and 4 weeks. Under the effect of cytrolane administration, the results showed significant increase in serum triglycerides, total cholesterol, HDL-cholesterol and CPK mean levels. Total serum protein and progesterone levels were significantly decreased compared to the control. On the other hand, by the administration of soyabean prior cytrolane, it reduced considerably the changes produced by cytrolane on levels of serum cholesterol, triglyceride, HDL-cholesterol which decreased more or less compared to control, total protein level was within normal value. Also, serum progesterone concentration increased. Therefore, soyabean administration accelerated the normalization and improvement processes of the altered lipid profiles, protein and progesterone hormone

  12. A ratiometric fluorescent quantum dots based biosensor for organophosphorus pesticides detection by inner-filter effect.

    Science.gov (United States)

    Yan, Xu; Li, Hongxia; Han, Xiaosong; Su, Xingguang

    2015-12-15

    In this work, we develop a novel and sensitive sensor for the detection of organophosphorus pesticides based on the inner-filter effect (IFE) between gold nanoparticles (AuNPs) and ratiometric fluorescent quantum dots (RF-QDs). The RF-QDs has been designed by hybridizing two differently colored CdTe QDs, in which the red emissive QDs entrapped in the silica sphere acting as the reference signal, and the green emissive QDs covalently attached on the silica surface serving as the response signal.The fluorescence of RF-QDs could be quenched by AuNPs based on IFE. Protamine could effectively turn on the fluorescence due to the electrostatic attraction between protamine and AuNPs. Trypsin can easily hydrolyze protamine, leading to the quench of the fluorescence. Then, the fluorescence could be recovered again by the addition of parathion-methyl (PM) which could inhibit the activity of trypsin. By measuring the fluorescence of RF-QDs, the inhibition efficiency of PM to trypsin activity was evaluated. Under the optimized conditions, the inhibition efficiency was proportional to the logarithm of PM concentration in the range of 0.04-400 ng mL(-1), with a detection limit of 0.018 ng mL(-1). Furthermore, the simple and convenient method had been used for PM detection in environmental and agricultural samples with satisfactory results. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Organophosphorus pesticides effect on early stages of the axolotl Ambystoma mexicanum (Amphibia: Caudata).

    Science.gov (United States)

    Robles-Mendoza, C; García-Basilio, C; Cram-Heydrich, S; Hernández-Quiroz, M; Vanegas-Pérez, C

    2009-02-01

    Ambystoma mexicanum is an endemic salamander of Xochimilco, a wetland of the basin of Mexico valley. Nowadays, axolotl populations are decreasing due environmental stressors. Particularly, studies about organophosphorus pesticides (OPPs; i.e. chlorpyrifos and malathion) toxicity are of great importance due to their intensive use in agricultural activities in Xochimilco. Thus, the aim of this study was to evaluate under controlled conditions the toxicity of chlorpyrifos (CPF) and malathion (MLT) on embryos and larvae (stage 44 and 54) of A. mexicanum. Embryos and larvae were exposure 96h from 0.5 to 3mg CPFL(-1) and from 10 to 30mg MLTL(-1) in independent tests. Embryos at the end of this period were maintained 9d without pesticide in order to identify possible recuperation. Differences obtained in mortality, hatching success, development, morphological abnormalities, behaviour and activity, suggest that toxicity of CPF and MLT differs in embryos and larval stages. Embryos were less sensitive to OPPs acute exposure than axolotl larvae; additionally, toxicity of CPF in larval stages was greater than MLT. On the other hand, data obtained in axolotl embryos during the period of recuperation to CPF in particular as delay and inhibition of development, malformations and success of hatching, indicated that these responses turned out more sensitive than mortality. This study allowed to identify the toxicological potential of OPPs on early developmental stages of A. mexicanum and it is a valuable contribution for the future management of the axolotl wild population.

  14. Biosensors and their applications in detection of organophosphorus pesticides in the environment.

    Science.gov (United States)

    Hassani, Shokoufeh; Momtaz, Saeideh; Vakhshiteh, Faezeh; Maghsoudi, Armin Salek; Ganjali, Mohammad Reza; Norouzi, Parviz; Abdollahi, Mohammad

    2017-01-01

    This review discusses the past and recent advancements of biosensors focusing on detection of organophosphorus pesticides (OPs) due to their exceptional use during the last decades. Apart from agricultural benefits, OPs also impose adverse toxicological effects on animal and human population. Conventional approaches such as chromatographic techniques used for pesticide detection are associated with several limitations. A biosensor technology is unique due to the detection sensitivity, selectivity, remarkable performance capabilities, simplicity and on-site operation, fabrication and incorporation with nanomaterials. This study also provided specifications of the most OPs biosensors reported until today based on their transducer system. In addition, we highlighted the application of advanced complementary materials and analysis techniques in OPs detection systems. The availability of these new materials associated with new sensing techniques has led to introduction of easy-to-use analytical tools of high sensitivity and specificity in the design and construction of OPs biosensors. In this review, we elaborated the achievements in sensing systems concerning innovative nanomaterials and analytical techniques with emphasis on OPs.

  15. New Cinchona Oximes Evaluated as Reactivators of Acetylcholinesterase and Butyrylcholinesterase Inhibited by Organophosphorus Compounds

    Directory of Open Access Journals (Sweden)

    Maja Katalinić

    2017-07-01

    Full Text Available For the last six decades, researchers have been focused on finding efficient reactivators of organophosphorus compound (OP-inhibited acetylcholinesterase (AChE and butyrylcholinesterase (BChE. In this study, we have focused our research on a new oxime scaffold based on the Cinchona structure since it was proven to fit the cholinesterases active site and reversibly inhibit their activity. Three Cinchona oximes (C1, C2, and C3, derivatives of the 9-oxocinchonidine, were synthesized and investigated in reactivation of various OP-inhibited AChE and BChE. As the results showed, the tested oximes were more efficient in the reactivation of BChE and they reactivated enzyme activity to up to 70% with reactivation rates similar to known pyridinium oximes used as antidotes in medical practice today. Furthermore, the oximes showed selectivity towards binding to the BChE active site and the determined enzyme-oxime dissociation constants supported work on the future development of inhibitors in other targeted studies (e.g., in treatment of neurodegenerative disease. Also, we monitored the cytotoxic effect of Cinchona oximes on two cell lines Hep G2 and SH-SY5Y to determine the possible limits for in vivo application. The cytotoxicity results support future studies of these compounds as long as their biological activity is targeted in the lower micromolar range.

  16. Catalytic Characteristics of New Antibacterials Based on Hexahistidine-Containing Organophosphorus Hydrolase

    Directory of Open Access Journals (Sweden)

    Olga Maslova

    2017-09-01

    Full Text Available Catalytic characteristics of hexahistidine-containing organophosphorus hydrolase (His6-OPH and its enzyme-polyelectrolyte complexes with poly-l-glutamic acid or poly-l-aspartic acid (His6-OPH/PLD50, hydrolyzing organophosphorous compounds, and N-acyl homoserine lactones were studied in the presence of various antibiotics (ampicillin, gentamicin, kanamycin, and rifampicin. The antibiotics at concentrations below 1 g·L−1 had a negligible inhibiting effect on the His6-OPH activity. Mixed inhibition of His6-OPH was established for higher antibiotic concentrations, and rifampicin was the most potent inhibitor. Stabilization of the His6-OPH activity was observed in the presence of antibiotics at a concentration of 0.2 g·L−1 during exposure at 25–41 °C. Molecular docking of antibiotics to the surface of His6-OPH dimer revealed the antibiotics binding both to the area near active centers of the enzyme subunits and to the region of contact between subunits of the dimer. Such interactions between antibiotics and His6-OPH were verified with Fourier-transform infrared (FTIR spectroscopy. Considering all the results of the study, the combination of His6-OPH/PLD50 with β-lactam antibiotic ampicillin was established as the optimal one in terms of exhibition and persistence of maximal lactonase activity of the enzyme.

  17. Degradation of Organophosphorus and Pyrethroid Insecticides in Beverages: Implications for Risk Assessment

    Directory of Open Access Journals (Sweden)

    Samantha A. Radford

    2018-02-01

    Full Text Available Since urinary insecticide metabolites are commonly used as biomarkers of exposure, it is important that we quantify whether insecticides degrade in food and beverages in order to better perform risk assessment. This study was designed to quantify degradation of organophosphorus and pyrethroid insecticides in beverages. Purified water, white grape juice, orange juice, and red wine were fortified with 500 ng/mL diazinon, malathion, chlorpyrifos, permethrin, cyfluthrin, cypermethrin, and deltamethrin, and aliquots were extracted several times over a 15-day storage period at 2.5 °C. Overall, statistically significant loss of at least one insecticide was observed in each matrix, and at least five out of seven insecticides demonstrated a statistically significant loss in all matrices except orange juice. An investigation of an alternative mechanism of insecticide loss—adsorption onto the glass surface of the storage jars—was carried out, which indicated that this mechanism of loss is insignificant. Results of this work suggest that insecticides degrade in these beverages, and this degradation may lead to pre-existing insecticide degradates in the beverages, suggesting that caution should be exercised when using urinary insecticide metabolites to assess exposure and risk.

  18. Gas chromatography with flame photometric detection of 31 organophosphorus pesticide residues in Alpinia oxyphylla dried fruits.

    Science.gov (United States)

    Zhao, Xiangsheng; Kong, Weijun; Wei, Jianhe; Yang, Meihua

    2014-11-01

    A simple, rapid and effective gas chromatography-flame photometric detection method was established for simultaneous multi-component determination of 31 organophosphorus pesticides (OPPs) residues in Alpinia oxyphylla, which is widely consumed as a traditional medicine and food in China. Sample preparation was completed in a single step without any clean-up procedure. All pesticides expressed good linear relationships between 0.004 and 1.0 μg/mL with correlation coefficients higher than 0.9973. The method gave satisfactory recoveries for most pesticides. The limits of detection varied from 1 to 10 ng/mL, and the limits of quantification (LOQs) were between 4 and 30 ng/mL. The proposed method was successfully applied to 55 commercial samples purchased from five different areas. Five pesticide residues were detected in four (7.27%) samples. The positive samples were confirmed by gas chromatography with tandem mass spectrometry (GC-MS/MS). Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Theoretical and experimental study of actinide complexes with monoamides and organophosphorus ligands in solution

    International Nuclear Information System (INIS)

    Ribokaite, Kristina

    2013-01-01

    Monoamides and organophosphate are of great interest for the nuclear fuel cycle. Such ligands can selectively extract actinides in liquid-liquid extraction processes. The structure of the extractant (its functional group and its alkyl substituents) has a predominant role in the selective separation of actinides. This thesis concerns the theoretical and experimental studies of model systems in the aim of better understanding of the effect on molecular structures of the complexes. Structures of actinides complexes formed with model ligands in simple media (water or methanol in the presence of nitrate ions) have been characterized. At first, the complexation of uranyl by monoamide and phosphine oxide was studied in water and methanol. Molecular Dynamics simulations and DFT calculations were used to quantify the stability of uranyl complexes with those ligands, and to determine their structural properties. The theoretical results were then compared with experimental results obtained by UV-visible, infrared, Raman and EXAFS on the same chemical systems. The results were used to highlight the greater stability of uranyl complexes with phosphine oxide and monoamides. Further spectroscopic measurements combined with molecular modeling were used to gain a better understanding of the coordination mode of nitrate ion around the uranyl in both water and methanol. Finally, DFT calculations were used to study the influence of the structure of the monoamide or organophosphorus ligand and their interaction with the actinides (IV, VI) including steric effects in the first coordination sphere. (author) [fr

  20. Pharmacological treatment of organophosphorus insecticide poisoning: the old and the (possible) new.

    Science.gov (United States)

    Eddleston, Michael; Chowdhury, Fazle Rabbi

    2016-03-01

    Despite being a major clinical and public health problem across the developing world, responsible for at least 5 million deaths over the last three decades, the clinical care of patients with organophosphorus (OP) insecticide poisoning has little improved over the last six decades. We are still using the same two antidotes - atropine and oximes - that first came into clinical use in the late 1950s. Clinical research in South Asia has shown how improved regimens of atropine can prevent deaths. However, we are still unsure about which patients are most likely to benefit from the use of oximes. Supplemental antidotes, such as magnesium, clonidine and sodium bicarbonate, have all been proposed and studied in small trials without production of definitive answers. Novel antidotes such as nicotinic receptor antagonists, beta-adrenergic agonists and lipid emulsions are being studied in large animal models and in pilot clinical trials. Hopefully, one or more of these affordable and already licensed antidotes will find their place in routine clinical care. However, the large number of chemically diverse OP insecticides, the varied poisoning they produce and their varied response to treatment might ultimately make it difficult to determine definitively whether these antidotes are truly effective. In addition, the toxicity of the varied solvents and surfactants formulated with the OP active ingredients complicates both treatment and studies. It is possible that the only effective way to reduce deaths from OP insecticide poisoning will be a steady reduction in their agricultural use worldwide. © 2015 The British Pharmacological Society.

  1. Cholinesterase reactivators and bioscavengers for pre- and post-exposure treatments of organophosphorus poisoning.

    Science.gov (United States)

    Masson, Patrick; Nachon, Florian

    2017-08-01

    Organophosphorus agents (OPs) irreversibly inhibit acetylcholinesterase (AChE) causing a major cholinergic syndrome. The medical counter-measures of OP poisoning have not evolved for the last 30 years with carbamates for pretreatment, pyridinium oximes-based AChE reactivators, antimuscarinic drugs and neuroprotective benzodiazepines for post-exposure treatment. These drugs ensure protection of peripheral nervous system and mitigate acute effects of OP lethal doses. However, they have significant limitations. Pyridostigmine and oximes do not protect/reactivate central AChE. Oximes poorly reactivate AChE inhibited by phosphoramidates. In addition, current neuroprotectants do not protect the central nervous system shortly after the onset of seizures when brain damage becomes irreversible. New therapeutic approaches for pre- and post-exposure treatments involve detoxification of OP molecules before they reach their molecular targets by administrating catalytic bioscavengers, among them phosphotriesterases are the most promising. Novel generation of broad spectrum reactivators are designed for crossing the blood-brain barrier and reactivate central AChE. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms. © 2017 International Society for Neurochemistry.

  2. Effects of organophosphorus flame retardant TDCPP on normal human corneal epithelial cells: Implications for human health.

    Science.gov (United States)

    Xiang, Ping; Liu, Rong-Yan; Li, Chao; Gao, Peng; Cui, Xin-Yi; Ma, Lena Q

    2017-11-01

    Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is one of the most detected organophosphorus flame retardants (OPFRs) in the environment, especially in indoor dust. Continuous daily exposure to TDCPP-containing dust may adversely impact human cornea. However, its detrimental effects on human corneal epithelium are largely unknown. In this study, we investigated the cell apoptosis in normal human corneal epithelial cells (HCECs) after TDCPP exposure and elucidated the underlying molecular mechanisms. Our data indicated a dose-dependent decrease of cell viability after TDCPP exposure with LC 50 at 202 μg/mL. A concentration-dependent apoptotic sign was observed in HCECs after exposing to ≥2 μg/mL TDCPP. Endoplasmic reticulum stress induction was evidenced by up-regulation of its biomarker genes (ATF-4, CHOP, BiP, and XBP1). Furthermore, alternation of Bcl-2/Bax expression, mitochondrial membrane potential loss, cellular ATP content decrease, and caspase-3 and -9 activity increase were observed after exposing to 2 or 20 μg/mL TDCPP. Taken together, the data implicated the involvement of endoplasmic reticulum stress in TDCPP-induced HCEC apoptosis, probably mediated by mitochondrial apoptotic pathway. Our findings showed TDCPP exposure induced toxicity to human cornea. Due to TDCPP's presence at high levels in indoor dust, further study is warranted to evaluate its health risk on human corneas. Published by Elsevier Ltd.

  3. Suicidal Death due to Organophosphorus Compound Poisoning ─ an Experience of 67 Cases

    Directory of Open Access Journals (Sweden)

    Nashid Tabassum Khan

    2016-05-01

    Full Text Available Background: Bangladesh is an agro-based country. Suicide by agrochemical compounds are increasing day by day in this country. Organophosphorus compounds (OPC are commonly used for suicide. Mostly these are used for suicidal purpose in rural areas in our country due to low cost, toxicity and availability. Objective: To find out the relationship of age and sex variation along with the causes that influenced different income group people to ingest OPC for committing suicide. Materials and Methods: This study was conducted in the Department of Forensic Medicine, Dhaka Medical College during January to December 2010. Data were collected at the time of autopsy and from postmortem examination report of viscera. Viscera were preserved and sent to the Chief Chemical Examiner’s Office, Dhaka for toxicological analysis. Results: In this study, middle aged subjects (20–30 years were found to commit suicide using OPC in comparison to other age groups. Among the cases male were 57% and female 43%. Poverty was found as the most common cause (20% of OPC poisoning. Conclusion: Poverty is the leading cause of death of OPC poisoning followed by failure in love and adultery. Business failure, unhappiness in conjugal life, demand for dowry and violence against women are other causes to commit suicide by OPC.

  4. Organophosphorus pesticide exposure in agriculture: effects of temperature, ultraviolet light and abrasion on PVC gloves

    Science.gov (United States)

    ISMAIL, Ismaniza; GASKIN, Sharyn; PISANIELLO, Dino; EDWARDS, John W.

    2017-01-01

    Elbow length PVC gloves are often recommended for protection against organophosphorus pesticide (OP) exposure in agriculture. However, performance may be reduced due to high temperature, UV exposure and abrasion. We sought to assess these impacts for two OPs under normal use and reasonable worst-case scenarios. Glove permeation tests were conducted using ASTM cells with two PVC glove brands at 23°C and 45°C for up to 8 h. Technical grade dichlorvos and formulated diazinon were used undiluted and at application strength. Breakthough of undiluted dichlorvos occurred at both 23°C and 45°C, but only at 45°C for application strength. Breakthrough of diazinon was not achieved, except when undiluted at 45°C. UV-exposed and abraded gloves showed reduced performance, with the effect being approximately two-fold for dichlorvos. Only small differences were noted between glove brands. Extra precautions should be taken when handling concentrated OPs at high temperature, or when using abraded or sunlight-exposed gloves. PMID:29199264

  5. Organophosphorus esters in the oceans and possible relation with ocean gyres

    International Nuclear Information System (INIS)

    Cheng, Wenhan; Xie, Zhouqing; Blais, Jules M.; Zhang, Pengfei; Li, Ming; Yang, Chengyun; Huang, Wen; Ding, Rui; Sun, Liguang

    2013-01-01

    Four organophosphorus esters (OPEs) were detected in aerosol samples collected in the West Pacific, the Indian Ocean and the Southern Ocean from 2009 to 2010, suggesting their circumpolar and global distribution. In general, the highest concentrations were detected near populated regions in China, Australia and New Zealand. OPE concentrations in the Southern Ocean were about two orders of magnitude lower than those near major continents. Additionally, relatively high OPE concentrations were detected at the Antarctic Peninsula, where several scientific survey stations are located. The four OPEs investigated here are significantly correlated with each other, suggesting they may derive from the same source. In the circumpolar transect, OPE concentrations were associated with ocean gyres in the open ocean. Their concentrations were positively related with average vorticity in the sampling area suggesting that a major source of OPEs may be found in ocean gyres where plastic debris is known to accumulate. -- Highlights: •We provide OPE concentrations in aerosols in a circumpolar expedition. •We find strong anthropogenic source of OPE pollution. •We suggest potential relationship between ocean gyres and OPE pollution. -- Our work provides a circumpolar investigation on OPEs in the Southern Ocean and we suggest a possibility that ocean currents and gyres may act as important roles in global transport of OPEs

  6. Computational Enzymology and Organophosphorus Degrading Enzymes: Promising Approaches Toward Remediation Technologies of Warfare Agents and Pesticides.

    Science.gov (United States)

    Ramalho, Teodorico C; de Castro, Alexandre A; Silva, Daniela R; Silva, Maria Cristina; Franca, Tanos C C; Bennion, Brian J; Kuca, Kamil

    2016-01-01

    The re-emergence of chemical weapons as a global threat in hands of terrorist groups, together with an increasing number of pesticides intoxications and environmental contaminations worldwide, has called the attention of the scientific community for the need of improvement in the technologies for detoxification of organophosphorus (OP) compounds. A compelling strategy is the use of bioremediation by enzymes that are able to hydrolyze these molecules to harmless chemical species. Several enzymes have been studied and engineered for this purpose. However, their mechanisms of action are not well understood. Theoretical investigations may help elucidate important aspects of these mechanisms and help in the development of more efficient bio-remediators. In this review, we point out the major contributions of computational methodologies applied to enzyme based detoxification of OPs. Furthermore, we highlight the use of PTE, PON, DFP, and BuChE as enzymes used in OP detoxification process and how computational tools such as molecular docking, molecular dynamics simulations and combined quantum mechanical/molecular mechanics have and will continue to contribute to this very important area of research.

  7. Toxicology of organophosphorus compounds in view of an increasing terrorist threat.

    Science.gov (United States)

    Worek, Franz; Wille, Timo; Koller, Marianne; Thiermann, Horst

    2016-09-01

    The implementation of the Chemical Weapon Convention (CWC), prohibiting the development, production, storage and use of chemical weapons by 192 nations and the ban of highly toxic OP pesticides, especially class I pesticides according to the WHO classification, by many countries constitutes a great success of the international community. However, the increased interest of terrorist groups in toxic chemicals and chemical warfare agents presents new challenges to our societies. Almost seven decades of research on organophosphorus compound (OP) toxicology was mainly focused on a small number of OP nerve agents despite the fact that a huge number of OP analogues, many of these agents having comparable toxicity to classical nerve agents, were synthesized and published. Only limited physicochemical, toxicological and medical information on nerve agent analogues is available in the open literature. This implies potential gaps of our capabilities to detect, to decontaminate and to treat patients if nerve agent analogues are disseminated and may result in inadequate effectiveness of newly developed countermeasures. In summary, our societies may face new, up to now disregarded, threats by toxic OP which calls for increased awareness and appropriate preparedness of military and civilian CBRN defense, a broader approach for new physical and medical countermeasures and an integrated system of effective detection, decontamination, physical protection and treatment.

  8. Determinants of Organophosphorus Pesticide Urinary Metabolite Levels in Young Children Living in an Agricultural Community

    Directory of Open Access Journals (Sweden)

    Brenda Eskenazi

    2011-04-01

    Full Text Available Organophosphorus (OP pesticides are used in agriculture and several are registered for home use. As young children age they may experience different pesticide exposures due to varying diet, behavior, and other factors. We measured six OP dialkylphosphate (DAP metabolites (three dimethyl alkylphosphates (DMAP and three diethyl alkylphosphates (DEAP in urine samples collected from ~400 children living in an agricultural community when they were 6, 12, and 24 months old. We examined bivariate associations between DAP metabolite levels and determinants such as age, diet, season, and parent occupation. To evaluate independent impacts, we then used generalized linear mixed multivariable models including interaction terms with age. The final models indicated that DMAP metabolite levels increased with age. DMAP levels were also positively associated with daily servings of produce at 6- and 24-months. Among the 6-month olds, DMAP metabolite levels were higher when samples were collected during the summer/spring versus the winter/fall months. Among the 12-month olds, DMAP and DEAP metabolites were higher when children lived ≤60 meters from an agricultural field. Among the 24-month-olds, DEAP metabolite levels were higher during the summer/spring months. Our findings suggest that there are multiple determinants of OP pesticide exposures, notably dietary intake and temporal and spatial proximity to agricultural use. The impact of these determinants varied by age and class of DAP metabolite.

  9. Specificity of carboxylesterase protection against the toxicity of organophosphorus compounds. (Reannouncement with new availability information)

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, D.M.

    1992-12-31

    The ability of endogenous carboxylesterase (CaE) to protect against the lethal effects of a variety of organophosphorus (OP) compounds was examined in rats. The in vivo protection provided by endogenous CaE was measured by the difference in the LD50 values of OP compounds in controlrats and rats whose CaE activity had been inhibited by sc injection with2 mg/kg of 2-(O cresyl)-4H-1,3,2-benzodi oxaphosphorin-2-oxide. Endogenous CaE provided significant protection against the in vivo toxicity of soman, sarin, tabun, and paraoxon, but not against dichlorvos, diisopropyl fluorophosphate, or ethoxymethyl-S-2- (DIISOPROPYLAMINO)ETHYL THIOPHOSPHONATE (VX). The relationship between the in vivo CaE protection against OP compounds and their relative reactivities with CaE and acetylcholinesterase (AChE) was evaluated by measuring the in vitro bimolecular rate constants (ki) for inhibition of plasma CaE and brain AChE. Except for VX, ki values for CaE inhibition varied <10-fold while ki values for AChE inhibition varied 105-fold. Chemical warfare agents, Nerve agents, Organophosphoruscompound soman, VX, Carboxylesterase, Protection, Pretreatment.

  10. [ACTIVITY OF Ca2+,Mg(2+)-ATPase OF SARCOPLASMIC RETICULUM AND CONTRACTION STRENGTH OF THE FROG SKELETAL MUSCLES UNDER THE EFFECT OF ORGANOPHOSPHORUS INSECTICIDES].

    Science.gov (United States)

    Nozdrenko, D M; Korchinska, L V; Soroca, V M

    2015-01-01

    The results of an experimental study of organophosphorus insecticides, including pirimiphosmethyl, diazinon and chlorpyrifos caused a decline of the contraction properties in m. tibialis anterior fiber bundles of Rana temporaria, as well as sarcoplasmic reticulum Ca2+, Mg(2+)-ATPase enzymatic activity reduction are outlined in this paper. Concentration-dependent strengths response diminishing in isolated skeletal muscle fiber bundles as a result of non-cholinergic influence of organophosphorus insecticides were found. A decrease of Ca2+, Mg(2+)-ATPase enzymatic activity in sarcoplasmic reticulum was observed after administration of each insecticide. The most significant inhibition of this enzyme was observed when using chlorpyrifos.

  11. Gas cell neutralizers (Fundamental principles)

    International Nuclear Information System (INIS)

    Fuehrer, B.

    1985-06-01

    Neutralizing an ion-beam of the size and energy levels involved in the neutral-particle-beam program represents a considerable extension of the state-of-the-art of neutralizer technology. Many different mediums (e.g., solid, liquid, gas, plasma, photons) can be used to strip the hydrogen ion of its extra electron. A large, multidisciplinary R and D effort will no doubt be required to sort out all of the ''pros and cons'' of these various techniques. The purpose of this particular presentation is to discuss some basic configurations and fundamental principles of the gas type of neutralizer cell. Particular emphasis is placed on the ''Gasdynamic Free-Jet'' neutralizer since this configuration has the potential of being much shorter than other type of gas cells (in the beam direction) and it could operate in nearly a continuous mode (CW) if necessary. These were important considerations in the ATSU design which is discussed in some detail in the second presentation entitled ''ATSU Point Design''

  12. Electromagnetic trapping of neutral atoms

    International Nuclear Information System (INIS)

    Metcalf, H.J.

    1986-01-01

    Cooling and trapping of neutral atoms is a new branch of applied physics that has potential for application in many areas. The authors present an introduction to laser cooling and magnetic trapping. Some basic ideas and fundamental limitations are discussed, and the first successful experiments are reviewed. Trapping a neutral object depends on the interaction between an inhomogeneous electromagnetic field and a multiple moment that results in the exchange of kinetic for potential energy. In neutral atom traps, the potential energy must be stored as internal atomic energy, resulting in two immediate and extremely important consequences. First, the atomic energy levels will necessarily shift as the atoms move in the trap, and, second, practical traps for ground state neutral atoms atr necessarily very shallow compared to thermal energy. This small depth also dictates stringent vacuum requirements because a trapped atom cannot survive a single collision with a thermal energy background gas molecule. Neutral trapping, therefore, depends on substantial cooling of a thermal atomic sample and is inextricably connected with the cooling process

  13. Effects of the organophosphorus pesticide Folisuper 600 (methyl parathion on the heart function of bullfrog tadpoles, Lithobates catesbeianus (Shaw, 1802

    Directory of Open Access Journals (Sweden)

    M. J. Costa

    Full Text Available Abstract The aim of this work was to evaluate whether the heart function of bullfrog tadpoles (25 Gosner stage is affected by their acute exposure (48 h to a sub-lethal concentration (10 µg.L–1 of the active principle of the organophosphorus pesticide Folisuper 600R (methyl parathion - MP. Our results demonstrated that MP causes not only a reduction in tadpoles’ cardiac ventricular mass, resulting in a marked reduction in their cardiac twitch force, but also impairs their swimming performance, irrespective of increasing their heart rate. Together, these findings indicate that low and realistic concentration of MP have a negative impact on tadpoles’ performance, jeopardizing their survival.

  14. Measurement of plasma production and neutralization in gas neutralizers

    International Nuclear Information System (INIS)

    Maor, D.; Meron, M.; Johnson, B.; Jones, K.; Agagu, A.; Hu, B.

    1986-01-01

    In order to satisfy the need of experimental data for the designing of gas neutralizers we have started a project aimed at measuring all relevant cross sections for the charge exchange of H - , H 0 and H + projectiles, as well as the cross sections for the production of ions in the target. The expected results of these latter measurements are shown schematically

  15. Neutral currents in semileptonic reactions

    International Nuclear Information System (INIS)

    Paschos, E.A.

    1975-05-01

    The evidence for weak neutral currents is analyzed in semileptonic reactions with special emphasis on their Lorentz and internal symmetry structure. It is found that present observations are consistent with the expectations of gauge theories, but other possibilities can not be ruled out. Of particular interest in this respect is the presence of a large isoscalar component. The excitation of the Δ-resonance by neutral currents is analyzed, and pion-nucleon mass distributions are presented. Charge asymmetries sensitive to isoscalar-isovector interferences are discussed. (U.S.)

  16. Phytase production by Aspergillus niger NCIM 563 for a novel application to degrade organophosphorus pesticides.

    Science.gov (United States)

    Shah, Parin C; Kumar, V Ravi; Dastager, Syed G; Khire, Jayant M

    2017-12-01

    The production of phytase using Aspergillus niger NCIM 563 under submerged fermentation conditions was studied using protein rich chickpea flour as substrate. Employing a hybrid statistical media optimization strategy of Plackett-Burman and Box-Behnken experimental designs in shake-flasks gave an increased phytase activity from an initial 66 IU/mL in 216 h to 160 IU/mL in a reduced time of 132 h. Productivity, thus increased by 3.97 times from 7.3 to 29 IU/mL/day. Using the optimized media, the production was successfully scaled-up further and improved up to 164 IU/mL in 96 h by studies carried out employing 2 and 10-L fermenters. The enzyme supernatant was recovered using centrifugal separation of biomass and the stability of the produced phytase was tested for animal feed applications under gastric conditions. In vitro degradation studies of water soluble monocrotophos, methyl parathion and water insoluble chlorpyrifos, pesticides used extensively in agriculture was carried out. It was observed by HPLC analysis that phytase could degrade 72% of chlorpyrifos at pH 7.0, 35 °C. Comparable results were obtained with monocrotophos and methyl parathion. With chlorpyrifos at higher temperature 50 °C as much as 91% degradation could be obtained. The degradation of chlorpyrifos was further validated by spraying phytase on harvested green chilli (Capsicum annuum L) under normal conditions of pH 7.0, 35 °C and the degradation products obtained analyzed by LCMS. Thus, the present study brings out a potentially novel application of phytase for biodegradation of organophosphorus pesticides.

  17. Determination of Organophosphorus Pesticides in Soil by Dispersive Liquid–Liquid Microextraction and Gas Chromatography

    Science.gov (United States)

    Yang, Zhonghua; Liu, Yu; Liu, Donghui; Zhou, Zhiqiang

    2012-01-01

    In this article, a rapid and sensitive sample pretreatment technique for the determination of organophosphorus pesticides (OPPs) in soil samples is developed by using dispersive liquid–liquid microextraction (DLLME) combined with gas chromatography–flame photometric detection. Experimental conditions, including the kind of extraction and disperser solvent and their volumes, the extraction time, and the salt addition, are investigated, and the following experiment factors are used: 20 µL chlorobenzene as the extraction solvent; 1.0 mL acetonitrile as the disperser solvent; no addition of salt; and an extraction time of 1 min. Under the optimum conditions, the linearities for the three target OPPs (ethoprophos, chlorpyriphos, and profenofos) are obtained by five points in the concentration range of 2.5–1500 µg/kg, and three replicates are used for each point. Correlation coefficients vary from 0.9987 to 0.9997. The repeatability is tested by spiking soil samples at a concentration level of 5.0 µg/kg. The relative standard deviation (n = 3) varied between 2.0% and 6.6%. The limits of detection, based on a signal-to-noise ratio (S/N) of 3, range from 200 to 500 pg/g. This method is applied to the analysis of the spiked samples S1, S2, and S3, which are collected from the China Agriculture University's orchard, lawn, and garden, respectively. The recoveries for each target analyte are in the range between 87.9% and 108.0%, 87.4% and 108.0%, and 86.7% and 107.2%, respectively. PMID:22291051

  18. Zirconium(IV) functionalized magnetic nanocomposites for extraction of organophosphorus pesticides from environmental water samples.

    Science.gov (United States)

    Jiang, Li; Huang, Tengjun; Feng, Shun; Wang, Jide

    2016-07-22

    The widespread use of organophosphate pesticides (OPPs) in agriculture leads to residue accumulation in the environment which is dangerous to human health and disrupts the ecological balance. In this work, one nanocomposite immobilized zirconium (Zr, IV) was prepared and used as the affinity probes to quickly and selectively extract organophosphorus pesticides (OPPs) from water samples. The Fe3O4-ethylenediamine tetraacetic acid (EDTA)@Zr(IV) nanocomposites (NPs) were prepared by simply mixing Zr(IV) ions with Fe3O4-EDTA NPs synthesized by one-pot chemical co-precipitation method. The immobilized Zr(IV) ions were further utilized to capture OPPs based on their high affinity for the phosphate moiety in OPPs. Coupled with GC-MS, four OPPs were used as models to demonstrate the feasibility of this approach. Under the optimum conditions, the limits of detection for target OPPs were in the range of 0.10-10.30ngmL(-1) with relative standard deviations (RSDs) of 0.61-4.40% (n=3), respectively. The linear ranges were over three orders of magnitudes (correlation coefficients, R(2)>0.9995). The Fe3O4-EDTA@Zr(IV) NPs were successfully applied to extract OPPs samples with recoveries of 86.95-112.60% and RSDs of 1.20-10.42% (n=3) from two spiked real water. By the proposed method, the matrix interference could be effectively eliminated. We hope our finding can provide a promising alternative for the fast extraction of OPPs from complex real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  19. Spatial learning impairment in prepubertal guinea pigs prenatally exposed to the organophosphorus pesticide chlorpyrifos: Toxicological implications

    Science.gov (United States)

    Mamczarz, Jacek; Pescrille, Joseph D.; Gavrushenko, Lisa; Burke, Richard D.; Fawcett, William P.; DeTolla, Louis J.; Chen, Hegang; Pereira, Edna F.R.; Albuquerque, Edson X.

    2017-01-01

    Exposure of the developing brain to chlorpyrifos (CPF), an organophosphorus (OP) pesticide used extensively in agriculture worldwide, has been associated with increased prevalence of cognitive deficits in children, particularly boys. The present study was designed to test the hypothesis that cognitive deficits induced by prenatal exposure to sub-acute doses of CPF can be reproduced in precocial small species. To address this hypothesis, pregnant guinea pigs were injected daily with CPF (25 mg/kg, s.c.) or vehicle (peanut oil) for 10 days starting on presumed gestation day (GD) 53–55. Offspring were born around GD 65, weaned on postnatal day (PND) 20, and subjected to behavioral tests starting around PND 30. On the day of birth, butyrylcholinesterase (BuChE), an OP bioscavenger used as a biomarker of OP exposures, and acetylcholinesterase (AChE), a major molecular target of OP compounds, were significantly inhibited in the blood of CPF-exposed offspring. In their brains, BuChE, but not AChE, was significantly inhibited. Prenatal CPF exposure had no significant effect on locomotor activity or on locomotor habituation, a form of non-associative memory assessed in open fields. Spatial navigation in the Morris water maze (MWM) was found to be sexually dimorphic among guinea pigs, with males outperforming females. Prenatal CPF exposure impaired spatial learning more significantly among male than female guinea pigs and, consequently, reduced the sexual dimorphism of the task. The results presented here, which strongly support the test hypothesis, reveal that the guinea pig is a valuable animal model for preclinical assessment of the developmental neurotoxicity of OP pesticides. These findings are far reaching as they lay the groundwork for future studies aimed at identifying therapeutic interventions to treat and/or prevent the neurotoxic effects of CPF in the developing brain. PMID:27296654

  20. Effect of organophosphorus insecticides and their metabolites on astroglial cell proliferation

    International Nuclear Information System (INIS)

    Guizzetti, Marina; Pathak, Shantha; Giordano, Gennaro; Costa, Lucio G.

    2005-01-01

    Though little attention has been given to the possibility that glial cells may represent a target for the developmental neurotoxicity of organophosphorus (OP) insecticides, recent evidence, obtained in particular with chlorpyrifos (CP), suggests that developmental exposure to this compound may indeed target astrocytes. To substantiate and expand these observations, we carried out a series of in vitro studies utilizing fetal rat astrocytes and a human astrocytoma cell line, 1321N1 cells, to investigate the effect of the OPs CP, diazinon (DZ) and parathion (P), their oxygen analogs chlorpyrifos oxon (CPO), diazoxon (DZO) and paraoxon (PO), and their metabolites 3,5,6-trichloro-2-pyridinol (TCP), 2-isopropyl-6-methyl-4-pyrimidol (IMP) and para-nitrophenol (PNP), on cell proliferation. In fetal rat astrocytes and astrocytoma cells maintained in serum, CP, DZ, P, CPO, DZO, and PO induced a concentration-dependent inhibition in [ 3 H]thymidine incorporation with a very similar potency (IC 50 between 45 and 57 μM). Among the other metabolites, PNP was the most potent (IC 50 = 70-80 μM), while TCP and IMP were much less effective (IC 50 > 100 μM). Cytotoxicity appears to account only for a small part of the effect on DNA synthesis. OP insecticides and their oxons were three- to six-fold more potent in inhibiting [ 3 H]thymidine incorporation when cells were synchronized in the G 0 /G 1 phase of the cell cycle and re-stimulated by carbachol or epidermal growth factor. These results suggest that OP insecticides and their oxons affect astroglial cell proliferation and that the transition from the G 0 /G 1 to the S/G 2 phase of the cell cycle may be particularly sensitive to the action of these compounds

  1. Modulatory Effect Of Olive Oil On Toxicity Induced By Organophosphorus Pesticides In Male Rat

    International Nuclear Information System (INIS)

    AFIFI, E.A.A.; ALI, S.E.

    2009-01-01

    The present study was carried out to investigate the modulatory effect of olive oil (5 ml/kg b.wt.) against the toxicological effects of repeated daily oral administration of the organophosphorus pesticides malaphos (137.5 mg/kg), mephosfolan (0.89 mg/kg) and phosfolan (1.0 mg/kg) for one, two and four weeks on certain biochemical parameters such as serum albumin, globulin and A/G ratio, low density lipoprotein-cholesterol (LDL-cholesterol), high density lipoprotein-cholesterol (HDL-cholesterol), total cholesterol, total protein, gamma glutamyl transferase ( GT) and plasma triglycerides. In addition, modulation of blood urea, creatinine and uric acid were observed through all the experimental intervals. Also, the serum concentration of triiodothyronine (T 3 ), thyroxine (T 4 ) and thyroid stimulating hormone (TSH) were determined.The data obtained revealed significant decrease in serum total protein, albumin, globulin and HDL-cholesterol while significant increase in serum albumin to globulin ratio (A/G), triglycerides, creatinine, urea, uric acid, LDL-cholesterol, total cholesterol and GT in all treated groups was observed. On the other hand, the data recorded imbalance in thyroid function as a result of pesticides treatments, which donated that each of the three pesticides increased TSH secretion, while malaphos caused significant decrease in both T 3 and T 4 levels, mephosfolan increased T 4 and decreased T 3 levels, whereas phosfolan pesticide decreased T 4 and increased T 3 levels after one, two and four weeks post-treatment.Administration of olive oil during treatment with malaphos, mephosfolan and phosfolan pesticides attenuates to a great extent the destructive effects of pesticides on the assayed parameters, this effect is attributed to the beneficial properties whom olive oil possess as anti-oxidative potential that may act to protect the body organs against the pesticides toxicity and also due to the amelioration of oxidative stress of free radicals.

  2. Organophosphorus pesticides decrease M2 muscarinic receptor function in guinea pig airway nerves via indirect mechanisms.

    Directory of Open Access Journals (Sweden)

    Becky J Proskocil

    Full Text Available BACKGROUND: Epidemiological studies link organophosphorus pesticide (OP exposures to asthma, and we have shown that the OPs chlorpyrifos, diazinon and parathion cause airway hyperreactivity in guinea pigs 24 hr after a single subcutaneous injection. OP-induced airway hyperreactivity involves M2 muscarinic receptor dysfunction on airway nerves independent of acetylcholinesterase (AChE inhibition, but how OPs inhibit neuronal M2 receptors in airways is not known. In the central nervous system, OPs interact directly with neurons to alter muscarinic receptor function or expression; therefore, in this study we tested whether the OP parathion or its oxon metabolite, paraoxon, might decrease M2 receptor function on peripheral neurons via similar direct mechanisms. METHODOLOGY/PRINCIPAL FINDINGS: Intravenous administration of paraoxon, but not parathion, caused acute frequency-dependent potentiation of vagally-induced bronchoconstriction and increased electrical field stimulation (EFS-induced contractions in isolated trachea independent of AChE inhibition. However, paraoxon had no effect on vagally-induced bradycardia in intact guinea pigs or EFS-induced contractions in isolated ileum, suggesting mechanisms other than pharmacologic antagonism of M2 receptors. Paraoxon did not alter M2 receptor expression in cultured cells at the mRNA or protein level as determined by quantitative RT-PCR and radio-ligand binding assays, respectively. Additionally, a biotin-labeled fluorophosphonate, which was used as a probe to identify molecular targets phosphorylated by OPs, did not phosphorylate proteins in guinea pig cardiac membranes that were recognized by M2 receptor antibodies. CONCLUSIONS/SIGNIFICANCE: These data indicate that neither direct pharmacologic antagonism nor downregulated expression of M2 receptors contributes to OP inhibition of M2 function in airway nerves, adding to the growing evidence of non-cholinergic mechanisms of OP neurotoxicity.

  3. Evaluation of the organophosphorus hydrolase enzyme activity in creams and investigation of its stability

    Directory of Open Access Journals (Sweden)

    Mariye Rajaie

    2016-06-01

    Full Text Available The main purpose of this project is investigation of the organophosphorus hydrolase (OPH enzyme activity in water in oil (w/o and oil in water (o/w creams and investigation of the OPH enzyme stability in formulated creams. OPH enzyme was extracted and purified from strain flavobacterium. The w/o and o/w creams were prepared using different formulations. In order to achieve an emulsion with maximum stability, appropriate percentage of the cream components was selected by studying different formulations and the physical and chemical stability of the produced cream were considered. 5Uenzyme/90gcream enzyme was used for each formulation. To measure the enzyme activity in creams, extraction method was used and enzyme activity was determined based on parathion hydrolysis. The thermal stability of OPH in both types of w/o and o/w creams was studied at 4 and 30  °C for various time periods. The average enzyme activity was about 0.0065 U/gcream and 0.018 U/gcream for w/o and o/w creams respectivly. According to the results, the relative activity at 4 °C was reduced to 50% after 26 and 45 days in w/o and o/w creams, respectivly. The results showed that the OPH enzyme activity in o/w cream was 2.6 times more than that of w/o cream, because of the higher hydrophobicity of o/w cream compared to w/o. The OPH enzyme stability in o/w cream was greater in comparison to w/o cream. The OPH enzyme was active for nearly 2 months on o/w creams at 4 °C .

  4. Dialkyl phosphate metabolites of organophosphorus in applicators of agricultural pesticides in Majes – Arequipa (Peru

    Directory of Open Access Journals (Sweden)

    Chung Arturo

    2006-12-01

    Full Text Available Abstract Background Organophosphorus (OPs pesticides are the most commonly used pesticides in Peruvian agriculture. The population at risk for OPs exposure includes formulators, applicators and farmers. Majes Valley is the most important agricultural center of the Southern region of Peru. The present study was aimed to determine the knowledge about using OPs, safety practice and urinary dialkylphosphate metabolites on OP applicators in the Majes Valley, Peru. Methods This study was based on a questionnaire which included socio-demographic characteristics, knowledge of safety practices to handling OPs, characteristics of pesticide application and use of protective measures to avoid pesticide contamination. Exposure was assessed by measuring six urinary OP metabolites (DMP, DMTP, DMDTP, DEP, DETP, and DEDTP by gas chromatography using a single flame photometric detector. The sample consisted of 31 men and 2 women aged 20 – 65 years old. Results 76% of applicators had at least one urinary dialkylphosphate metabolite above the limit of detection. The geometric mean (GM and the geometric standard deviation (GSD of DMP and DEP were 5.73 ug/g cr. (GSD 2.51, and 6.08 ug/g cr. (GSD 3.63, respectively. The percentage of applicators with detectable DMP, DMDTP, and DMTP in urine was 72.72%, 3.03%, and 15.15%, respectively, while the corresponding figures for DEP, DETP, and DEDTP were 48.48%, 36.36% and 15.15%, respectively. There was no significant association between the use of protection practices and the absence of urine OPs metabolites suggesting inadequate protection practices. Conclusion The pesticide applicators in Majes Valley have significant exposure to OP pesticides, probably due to inappropriate protective practices. Future work should evaluate possible health effects.

  5. Organophosphorus pollutants (OPP) in aquatic environment at Damietta Governorate, Egypt: implications for monitoring and biomarker responses.

    Science.gov (United States)

    Abdel-Halim, K Y; Salama, A K; El-Khateeb, E N; Bakry, N M

    2006-06-01

    The study was carried out from spring 1999 to spring 2001 to monitor the residue levels of organophosphorus pollutants (OPP) in aquatic environment of the drainage canal surrounding a pesticide factory at Damietta Governorate. Water, sediment, and fish samples were collected at six different seasonal periods. OPPs were analyzed by GLC and confirmed using GC-MS. Chlorpyrifos, chlorpyrifos-methyl, malathion, diazinon, pirimiphos-methyl and profenofos were detected in most samples. Chlorpyrifos was dominant in all water and sediment samples. It was ranged from 24.5 to 303.8 and 0.9 to 303.8 ppb in water and sediment samples, respectively. Diazinon level was slightly similar to chlorpyrifos in fish samples. Data based on the grand total concentration of OPP showed that the most polluted samples were collected either at spring 1999 or autumn 2000. They were 675.5 and 303.8 ppb in water samples and 43.0 and 52.2 ppb in fish collected at spring 1999 and autumn 2000, respectively. The obtained results are in parallel to that found in case of cholinesterase activity where the activity of both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) was declined at these seasonal period. The activity levels of AChE and BuChE were found to be 77.18% and 59.67% of control at spring 1999 and 78.62% and 85.80% of control, at autumn 2000, respectively. Thus, AChE and BuChE could be used as biomarkers for tracing and biomonitoring OPP pollution.

  6. Antioxidant Role of Pomegranates on Liver and Brain Tissues of Rats Exposed to an Organophosphorus Insecticide

    International Nuclear Information System (INIS)

    Abd Elmonem, H.A.

    2014-01-01

    Toxicities of organophosphorus insecticides cause oxidative damage on many organs such as the liver and brain due to generation of reactive oxygen species. Pomegranate is among the richest fruit in poly - phenols. The aim of this study was to compare between the antioxidant strength of pomegranate juice (PJ) and pomegranate molasses (PM) and their effects on alanine transferase (ALT), aspartate aminotransferase (AST), Alkaline phosphatase (ALP) and total protein (TP) in liver and levels of malondialdehyde (MAD), reduced glutathione (GSH) and nitric oxide (NO) in rat liver and brain tissues exposed to 1/10 LD 50 diazinon (DI). Six groups each of 6 male albino rats were used comprising control, DI, PJ, PM, PJ + DI and PM + DI for 15 days. The activities of ALT, AST, and TP concentration in liver have been increased due to treatment of rats with DI. These increases restored to normalcy when rats were supplemented with PJ or PM with DI. The results demonstrate that treatment with DI induced significant increase in MDA and NO concentrations and significant decrease in GSH levels of liver and brain tissues. The administration of PJ or PM along with DI significant decrease in MDA and NO levels and significant increase in GSH level compared to DI-group. The present study suggest that PJ or PM has a potential protective effect as it can elevate antioxidant defense system, lessens induced oxidative dam - ages and protect the brain and liver tissue against DI-induced toxicity. In addition, comaring PJ with PM it was noticed that PJ had higher antioxidant activity as evidenced by increased GSH content and decreased NO level in the liver by greater extend than PM.

  7. Evaluation of medical countermeasures against organophosphorus compounds: the value of experimental data and computer simulations.

    Science.gov (United States)

    Worek, Franz; Aurbek, Nadine; Herkert, Nadja M; John, Harald; Eddleston, Michael; Eyer, Peter; Thiermann, Horst

    2010-09-06

    Despite extensive research for more than six decades on medical countermeasures against poisoning by organophosphorus compounds (OP) the treatment options are meagre. The presently established acetylcholinesterase (AChE) reactivators (oximes), e.g. obidoxime and pralidoxime, are insufficient against a number of nerve agents and there is ongoing debate on the benefit of oxime treatment in human OP pesticide poisoning. Up to now, the therapeutic efficacy of oximes was mostly evaluated in animal models but substantial species differences prevent direct extrapolation of animal data to humans. Hence, it was considered essential to establish relevant experimental in vitro models for the investigation of oximes as antidotes and to develop computer models for the simulation of oxime efficacy in different scenarios of OP poisoning. Kinetic studies on the various interactions between erythrocyte AChE from various species, structurally different OP and different oximes provided a basis for the initial assessment of the ability of oximes to reactivate inhibited AChE. In the present study, in vitro enzyme-kinetic and pharmacokinetic data from a minipig model of dimethoate poisoning and oxime treatment were used to calculate dynamic changes of AChE activities. It could be shown that there is a close agreement between calculated and in vivo AChE activities. Moreover, computer simulations provided insight into the potential and limitations of oxime treatment. In the end, such data may be a versatile tool for the ongoing discussion of the pros and cons of oxime treatment in human OP pesticide poisoning. Copyright (c) 2009 Elsevier Ireland Ltd. All rights reserved.

  8. Developmental neurotoxicity of the organophosphorus insecticide chlorpyrifos: from clinical findings to preclinical models and potential mechanisms.

    Science.gov (United States)

    Burke, Richard D; Todd, Spencer W; Lumsden, Eric; Mullins, Roger J; Mamczarz, Jacek; Fawcett, William P; Gullapalli, Rao P; Randall, William R; Pereira, Edna F R; Albuquerque, Edson X

    2017-08-01

    Organophosphorus (OP) insecticides are pest-control agents heavily used worldwide. Unfortunately, they are also well known for the toxic effects that they can trigger in humans. Clinical manifestations of an acute exposure of humans to OP insecticides include a well-defined cholinergic crisis that develops as a result of the irreversible inhibition of acetylcholinesterase (AChE), the enzyme that hydrolyzes the neurotransmitter acetylcholine (ACh). Prolonged exposures to levels of OP insecticides that are insufficient to trigger signs of acute intoxication, which are hereafter referred to as subacute exposures, have also been associated with neurological deficits. In particular, epidemiological studies have reported statistically significant correlations between prenatal subacute exposures to OP insecticides, including chlorpyrifos, and neurological deficits that range from cognitive impairments to tremors in childhood. The primary objectives of this article are: (i) to address the short- and long-term neurological issues that have been associated with acute and subacute exposures of humans to OP insecticides, especially early in life (ii) to discuss the translational relevance of animal models of developmental exposure to OP insecticides, and (iii) to review mechanisms that are likely to contribute to the developmental neurotoxicity of OP insecticides. Most of the discussion will be focused on chlorpyrifos, the top-selling OP insecticide in the United States and throughout the world. These points are critical for the identification and development of safe and effective interventions to counter and/or prevent the neurotoxic effects of these chemicals in the developing brain. This is an article for the special issue XVth International Symposium on Cholinergic Mechanisms. © 2017 International Society for Neurochemistry.

  9. ITER Neutral Beam Injection System

    International Nuclear Information System (INIS)

    Ohara, Yoshihiro; Tanaka, Shigeru; Akiba, Masato

    1991-03-01

    A Japanese design proposal of the ITER Neutral Beam Injection System (NBS) which is consistent with the ITER common design requirements is described. The injection system is required to deliver a neutral deuterium beam of 75MW at 1.3MeV to the reactor plasma and utilized not only for plasma heating but also for current drive and current profile control. The injection system is composed of 9 modules, each of which is designed so as to inject a 1.3MeV, 10MW neutral beam. The most important point in the design is that the injection system is based on the utilization of a cesium-seeded volume negative ion source which can produce an intense negative ion beam with high current density at a low source operating pressure. The design value of the source is based on the experimental values achieved at JAERI. The utilization of the cesium-seeded volume source is essential to the design of an efficient and compact neutral beam injection system which satisfies the ITER common design requirements. The critical components to realize this design are the 1.3MeV, 17A electrostatic accelerator and the high voltage DC acceleration power supply, whose performances must be demonstrated prior to the construction of ITER NBI system. (author)

  10. Laser cooling of neutral atoms

    International Nuclear Information System (INIS)

    1993-01-01

    A qualitative description of laser cooling of neutral atoms is given. Two of the most important mechanisms utilized in laser cooling, the so-called Doppler Cooling and Sisyphus Cooling, are reviewed. The minimum temperature reached by the atoms is derived using simple arguments. (Author) 7 refs

  11. Climate Neutral Research Campuses | NREL

    Science.gov (United States)

    the background. Set an example for climate neutrality. Use NREL's climate action planning process and more. Climate Action Planning Process Identify the best technology options for a climate action plan . Climate Action Planning Tool Identify the best technology options for a climate action plan. Technology

  12. PLT neutral beam injection systems

    International Nuclear Information System (INIS)

    Menon, M.M.; Barber, G.C.; Blue, C.W.

    1979-01-01

    A brief description of the Princeton Large Torus (PLT) neutral beam injection system is given and its performance characteristics are outlined. A detailed operational procedure is included, as are some tips on troubleshooting. Proper operation of the source is shown to be a crucial factor in system performance

  13. Neutral Models with Generalised Speciation

    NARCIS (Netherlands)

    Haegeman, Bart; Etienne, Rampal S.

    Hubbell's neutral theory claims that ecological patterns such as species abundance distributions can be explained by a stochastic model based on simple assumptions. One of these assumptions, the point mutation assumption, states that every individual has the same probability to speciate. Etienne et

  14. Multimegawatt neutral beams for tokamaks

    International Nuclear Information System (INIS)

    Kunkel, W.B.

    1979-03-01

    Most of the large magnetic confinement experiments today and in the near future use high-power neutral-beam injectors to heat the plasma. This review briefly describes this remarkable technique and summarizes recent results as well as near term expectations. Progress has been so encouraging that it seems probable that tokamaks will achieve scientific breakeven before 1990

  15. Heavy neutral leptons at FASER

    Science.gov (United States)

    Kling, Felix; Trojanowski, Sebastian

    2018-05-01

    We study the prospects for discovering heavy neutral leptons at Forward Search Experiment (FASER), the newly proposed detector at the LHC. Previous studies showed that a relatively small detector with ˜10 m length and ≲1 m2 cross sectional area can probe large unconstrained parts of parameter space for dark photons and dark Higgs bosons. In this work, we show that FASER will also be sensitive to heavy neutral leptons that have mixing angles with the active neutrinos that are up to an order of magnitude lower than current bounds. In particular, this is true for heavy neutral leptons produced dominantly in B -meson decays, in which case FASER's discovery potential is comparable to the proposed SHiP detector. We also illustrate how the search for heavy neutral leptons at FASER will be complementary to ongoing searches in high-pT experiments at the LHC and can shed light on the nature of dark matter and the process of baryogenesis in the early Universe.

  16. Money neutrality: Rethinking the myth

    Directory of Open Access Journals (Sweden)

    Issaoui Fakhri

    2015-01-01

    Full Text Available Considered as an axiomatic basis of classical, neoclassical, and monetarist theories, the long-run money neutrality assumption does not always seem to be verified. Indeed, in our view, the money, in the sense of M2, can constitute a long-run channel of growth transmission. Thus, this paper examines the long-term relationship among money supply (M2, income (GDP, and prices (CPI. The subprime crisis in 2007 has shown that the demand for money does not only meet motives of transaction, precaution, and speculation but also of fictional or quasi-fictional future demands due to the fact that they are created without real counterparts. The capacity of production systems in developed countries to respond to increases in money supply by creating more wealth, involves the assumption of money neutrality in the long-run. However, in developing countries, the excess of money supply may lead to inflation trends. The present study has confirmed the long-term non-neutrality of money supply in the USA, and its neutrality in Gabon and Morocco.

  17. The manipulation of neutral particles

    International Nuclear Information System (INIS)

    Chu, S.

    1998-01-01

    The article is a translation of the lecture delivered on the occasion of the 1997 Nobel Prize awarding ceremony. The author's personal contribution to the discovery of laser cooling and trapping of neutral atoms is described, and applications of this phenomenon in atomic physics are highlighted. The article is completed by Mr. Steven Chu's autobiography

  18. Net Neutrality in the Netherlands

    NARCIS (Netherlands)

    van Eijk, N.

    2014-01-01

    The Netherlands is among the first countries that have put specific net neutrality standards in place. The decision to implement specific regulation was influenced by at least three factors. The first was the prevailing social and academic debate, partly due to developments in the United States. The

  19. Dust Measurement of Two Organophosphorus Flame Retardants, Resorcinol Bis(diphenylphosphate) (RBDPP) and Bisphenol A Bis(diphenylphosphate) (BPA-BDPP), Used as Alternatives for BDE-209

    NARCIS (Netherlands)

    Brandsma, S.H.; Sellström, U.; de Wit, C.A.; de Boer, J.; Leonards, P.E.G.

    2013-01-01

    Resorcinol bis(diphenylphosphate) (RBDPP) and bisphenol A bis(diphenylphosphate) (BPA-BDPP) are two halogen-free organophosphorus flame retardant (PFRs) that are used as an alternative for the decabromodiphenyl ether (Deca-BDE) technical mixture in TV/flatscreen housing and other electronic consumer

  20. Monitoring of organochlorine and organophosphorus pesticide residues in water during different seasons of Tighra reservoir Gwalior, Madhya Pradesh, India.

    Science.gov (United States)

    Mamta; Rao, R J; Wani, Khursheed Ahmad

    2015-11-01

    Analysis of pesticides during different seasons for pesticidal contamination in water samples of Tighra reservoir was carried out on gas chromatograph-electron capture detector with capillary columns following multiresidual analytical technique. Organochlorine pesticides, viz., hexachlorobenzene (HCB), alpha-benzene hexachloride (BHC), beta-BHC, γ-BHC, heptachlor, aldrin, alpha-endosulfan, beta-endosulfan, p,p-DDE, dieldrin, o,p-dichlorodiphenyldichloroethane (DDD), p,p-DDD, p,p-dichlorodiphenyltrichloroethane (DDT), and endrin, and organophosphorus pesticides, viz., choloropyrifos, methyl parathion, diazion, dicholorovos, ethion, malathion, and parathion, were detected in water samples during different seasons. However, the pesticide concentration varied during different seasons at different sites. The prominent reason of contamination is the use of pesticides (both organochlorine and organophosphorus) in the agricultural fields near Tighra reservoir. On the basis of our observations, more extensive monitoring studies need to be carried out, covering all wetlands of Madhya Pradesh to enforce the policies for the restricted application of pesticides in agricultural fields adjacent to wetlands.

  1. Pharmacokinetics and effects on serum cholinesterase activities of organophosphorus pesticides acephate and chlorpyrifos in chimeric mice transplanted with human hepatocytes.

    Science.gov (United States)

    Suemizu, Hiroshi; Sota, Shigeto; Kuronuma, Miyuki; Shimizu, Makiko; Yamazaki, Hiroshi

    2014-11-01

    Organophosphorus pesticides acephate and chlorpyrifos in foods have potential to impact human health. The aim of the current study was to investigate the pharmacokinetics of acephate and chlorpyrifos orally administered at lowest-observed-adverse-effect-level doses in chimeric mice transplanted with human hepatocytes. Absorbed acephate and its metabolite methamidophos were detected in serum from wild type mice and chimeric mice orally administered 150mg/kg. Approximately 70% inhibition of cholinesterase was evident in plasma of chimeric mice with humanized liver (which have higher serum cholinesterase activities than wild type mice) 1day after oral administrations of acephate. Adjusted animal biomonitoring equivalents from chimeric mice studies were scaled to human biomonitoring equivalents using known species allometric scaling factors and in vitro metabolic clearance data with a simple physiologically based pharmacokinetic (PBPK) model. Estimated plasma concentrations of acephate and chlorpyrifos in humans were consistent with reported concentrations. Acephate cleared similarly in humans and chimeric mice but accidental/incidental overdose levels of chlorpyrifos cleared (dependent on liver metabolism) more slowly from plasma in humans than it did in mice. The data presented here illustrate how chimeric mice transplanted with human hepatocytes in combination with a simple PBPK model can assist evaluations of toxicological potential of organophosphorus pesticides. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Novel organophosphorus scaffolds of urease inhibitors obtained by substitution of Morita-Baylis-Hillman adducts with phosphorus nucleophiles.

    Science.gov (United States)

    Ntatsopoulos, Vassilis; Vassiliou, Stamatia; Macegoniuk, Katarzyna; Berlicki, Łukasz; Mucha, Artur

    2017-06-16

    The reactivity of Morita-Baylis-Hillman allyl acetates was employed to introduce phosphorus-containing functionalities to the side chain of the cinnamic acid conjugated system by nucleophilic displacement. The proximity of two acidic groups, the carboxylate and phosphonate/phosphinate groups, was necessary to form interactions in the active site of urease by recently described inhibitor frameworks. Several organophosphorus scaffolds were obtained and screened for inhibition of the bacterial urease, an enzyme that is essential for survival of urinary and gastrointestinal tract pathogens. α-Substituted phosphonomethyl- and 2-phosphonoethyl-cinnamate appeared to be the most potent and were further optimized. As a result, one of the most potent organophosphorus inhibitors of urease, α-phosphonomethyl-p-methylcinnamic acid, was identified, with K i  = 0.6 μM for Sporosarcina pasteurii urease. High complementarity to the enzyme active site was achieved with this structure, as any further modifications significantly decreased its affinity. Finally, this work describes the challenges faced in developing ligands for urease. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Synthesis of organophosphorus modified nanoparticles and their reinforcements on the fire safety and mechanical properties of polyurea

    Energy Technology Data Exchange (ETDEWEB)

    Qian, Xiaodong [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); USTC-CityU Joint Advanced Research Centre, Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road Suzhou, Jiangsu 215123 (China); Song, Lei, E-mail: leisong@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Wang, Bibo [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); Hu, Yuan, E-mail: yuanhu@ustc.edu.cn [State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026 (China); USTC-CityU Joint Advanced Research Centre, Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road Suzhou, Jiangsu 215123 (China); Yuen, Richard K.K., E-mail: Richard.Yuen@cityu.edu.hk [USTC-CityU Joint Advanced Research Centre, Suzhou Key Laboratory of Urban Public Safety, Suzhou Institute for Advanced Study, University of Science and Technology of China, 166 Ren’ai Road Suzhou, Jiangsu 215123 (China); Department of Building and Construction, City University of Hong Kong, Tat Chee Avenue Kowloon (Hong Kong)

    2013-05-15

    Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized by the hydrolysis and condensation of both 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide modified vinyl trimethoxy silane (DOPO-VTS) and 3-triethoxysilylpropylamine. FRs-nanoparticles were incorporated into the polyurea matrix in different ratios via in situ polymerization, resulting in the formation of organic/inorganic nanocomposites. The nanocomposites were characterized by thermogravimetric analysis (TGA), real-time fourier transform infrared spectra (RTIR), microscale combustion calorimeter (MCC) and tensile testing machine. The TGA results revealed that FRs-nanoparticles could slightly catalyze the thermal degradation of the nanocomposites in nitrogen atmosphere, but significantly improve the thermal stability of the nanocomposites in air atmosphere. The T{sub 0.5} (50wt.% weight loss) of the nanocomposites was delayed by 32 °C in air atmosphere. Moreover, the char yield increased from 2.3wt.% to 8.9 wt.% at 550 °C when the loadings of FRs-nanoparticles was 10wt.%, indicating the catalyzing charring effect of FRs-nanoparticles. The MCC results revealed that all the nanocomposites exhibited much lower flammability compared with virgin polyurea. Furthermore, the tensile test indicated that the FRs-nanoparticles could also improve the mechanical properties of polyurea. - Highlights: ► Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized. ► FRs-nanoparticles were incorporated into the polyurea. ► Both the thermal stability and mechanical properties of polyurea were improved.

  4. Detection of Organophosphorus Pesticides in Wheat by Ionic Liquid-Based Dispersive Liquid-Liquid Microextraction Combined with HPLC

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2018-01-01

    Full Text Available Food safety issues closely related to human health have always received widespread attention from the world society. As a basic food source, wheat is the fundamental support of human survival; therefore, the detection of pesticide residues in wheat is very necessary. In this work, the ultrasonic-assisted ionic liquid-dispersive liquid-liquid microextraction (DLLME method was firstly proposed, and the extraction and analysis of three organophosphorus pesticides were carried out by combining high-performance liquid chromatography (HPLC. The extraction efficiencies of three ionic liquids with bis(trifluoromethylsulfonylimide (Tf2N anion were compared by extracting organophosphorus in wheat samples. It was found that the use of 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonylimide ([OMIM][Tf2N] had both high enrichment efficiency and appropriate extraction recovery. Finally, the method was used for the determination of three wheat samples, and the recoveries of them were 74.8–112.5%, 71.8–104.5%, and 83.8–115.5%, respectively. The results show that the method proposed is simple, fast, and efficient, which can be applied to the extraction of organic matters in wheat samples.

  5. Synthesis of organophosphorus modified nanoparticles and their reinforcements on the fire safety and mechanical properties of polyurea

    International Nuclear Information System (INIS)

    Qian, Xiaodong; Song, Lei; Wang, Bibo; Hu, Yuan; Yuen, Richard K.K.

    2013-01-01

    Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized by the hydrolysis and condensation of both 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide modified vinyl trimethoxy silane (DOPO-VTS) and 3-triethoxysilylpropylamine. FRs-nanoparticles were incorporated into the polyurea matrix in different ratios via in situ polymerization, resulting in the formation of organic/inorganic nanocomposites. The nanocomposites were characterized by thermogravimetric analysis (TGA), real-time fourier transform infrared spectra (RTIR), microscale combustion calorimeter (MCC) and tensile testing machine. The TGA results revealed that FRs-nanoparticles could slightly catalyze the thermal degradation of the nanocomposites in nitrogen atmosphere, but significantly improve the thermal stability of the nanocomposites in air atmosphere. The T 0.5 (50wt.% weight loss) of the nanocomposites was delayed by 32 °C in air atmosphere. Moreover, the char yield increased from 2.3wt.% to 8.9 wt.% at 550 °C when the loadings of FRs-nanoparticles was 10wt.%, indicating the catalyzing charring effect of FRs-nanoparticles. The MCC results revealed that all the nanocomposites exhibited much lower flammability compared with virgin polyurea. Furthermore, the tensile test indicated that the FRs-nanoparticles could also improve the mechanical properties of polyurea. - Highlights: ► Novel organophosphorus modified nanoparticles (FRs-nanoparticles) were synthesized. ► FRs-nanoparticles were incorporated into the polyurea. ► Both the thermal stability and mechanical properties of polyurea were improved

  6. Studies on coordination chemistry and bioactivity of metal complexes of a bidentate NN schiff base, (2-pyridyl-methylene)(phenyl) hydrazine, produced from the condensation of pyridine-2-carboxaldehyde with phenylhydrazine

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Zakaria, C.M.; Idrus, Razmi Mohd; Crouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

    2003-07-01

    A bidentate Schiff base, (2-pyridyl-methylene)(phenyl) hydrazine, with NN donor sequence, was isolated from the condensation of pyridine-2-carboxaldehyde with phenylhydrazine in ethanol. Metal complexes of this ligand with Ni(II), Zn(It), and Cu(n) ions were synthesized and characterized by a variety of physico-chemical techniques. The structure of the Schiff base was solved by X-ray diffraction studies, which indicated that it was monoclinic with a space group of C2/c. The complexes were all four coordinated. The compounds were tested against four pathogenic bacteria and fungi. The nickel complex, [Ni(NN) 2 Cl 2 ], in particular, was found to be active against all the fungi tested. The complexes were however inactive against leukemic cell lines (CEM-SS). (author)

  7. Studies on coordination chemistry and bioactivity of complexes of a bidentate oxygen-oxygen donor ligand, 1,2-dibenzoylhydrazine, with Cr3+, Co2+, Ni2+, Cu2+ and Zn2+ Ions

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Lai Wee Wong; Crouse, Karen A.; Ali, A.M.; Yamin, B.M.; Fun, H.-K.

    2003-08-01

    A new bidentate ligand, 1,2-dibenzoylhydrazine (DBHz), with OO donor sequences, was prepared. Several complexes of DBHz containing Cr(JJI), Fe(UI), Co(U), Ni(JJ), Cu(II) and Zn(TJ) ions have been synthesized and characterized by CHN analyses, IR, molar conductivity and UV/Visible spectroscopic studies. All of the compounds were tested for their antibacterial, antifungal and anticancer properties. DBHz was very effective against Pseudomonas aeruginosa, Bacillus subtilis mutant and Bacillus subtilis wild type bacteria. It was also effective against Saccaromyces cereiviceae, Candida albicans, Candida albicans lypolytica and Aspergillus ochraceous fungi. The free ligand, DBHz, in particular, was strongly active against colon cancer cell lines (HT-29), with a CD 50 value of 2.5 /μg/ml. (author)

  8. Coordination chemistry and bioactivity of Ni2+, Cu2+, and Zn2+ complexes containing a bidentate NS ligand, β-N-phenyldithiocarbazic acid, and the crystal structure of β-hydroxy-β-phenylmethylene α-phenylimine

    International Nuclear Information System (INIS)

    Tarafder, M.T.H.; Ahmed Faizal Shamsuddin; Grouse, Karen A.; Yamin, B.M.; Ali, A.M.; Fun, H.-K.

    2003-07-01

    A bidentate ligand (PhDTCH) with NS donor sequence was prepared from the reaction between carbon disulfide and phenylhydrazine in ethanol. Complexes of this ligand with Ni(II), Cu(II) and Zn(II) were synthesized and characterized by elemental analyses, and various physicochemical techniques. The metal complexes were all four coordinated. In an attempt to resolve the crystal structure of PhDTCH, an ethanolic solution, after leaving for a few days gave bright crystals of PhD6, β-hydroxy-β-phenylmethylene α-phenylimine, the crystal structure of which has been resolved. The crystal packing indicated that it is monoclinic with a space group of P21/n. All of the compounds were tested against different bacteria and fungi, and also against leukemic cell lines. All of the compounds showed weak biological properties compared to standard drugs. (author)

  9. Neutral atom traps of radioactives

    International Nuclear Information System (INIS)

    Behr, J.A.

    2003-01-01

    Neutral atoms trapped with modern laser cooling techniques offer the promise of improving several broad classes of experiments with radioactive isotopes. In nuclear β decay, neutrino spectroscopy from beta-recoil coincidences, along with highly polarized samples, enable experiments to search for non-Standard Model interactions, test whether parity symmetry is maximally violated, and search for new sources of time reversal violation. Ongoing efforts at TRIUMF, Los Alamos and Berkeley will be highlighted. The traps also offer bright sources for Doppler-free spectroscopy, particularly in high-Z atoms where precision measurements could measure the strength of weak neutral nucleon-nucleon and electron-nucleon interactions. Physics with francium atoms has been vigorously pursued at Stony Brook. Several facilities plan work with radioactive atom traps; concrete plans and efforts at KVI Groningen and Legnaro will be among those summarized. Contributions to the multidisciplinary field of trace analysis will be left up to other presenters

  10. Neutral atom traps of radioactives

    CERN Document Server

    Behr, J A

    2003-01-01

    Neutral atoms trapped with modern laser cooling techniques offer the promise of improving several broad classes of experiments with radioactive isotopes. In nuclear beta decay, neutrino spectroscopy from beta-recoil coincidences, along with highly polarized samples, enable experiments to search for non-Standard Model interactions, test whether parity symmetry is maximally violated, and search for new sources of time reversal violation. Ongoing efforts at TRIUMF, Los Alamos and Berkeley will be highlighted. The traps also offer bright sources for Doppler-free spectroscopy, particularly in high-Z atoms where precision measurements could measure the strength of weak neutral nucleon-nucleon and electron-nucleon interactions. Physics with francium atoms has been vigorously pursued at Stony Brook. Several facilities plan work with radioactive atom traps; concrete plans and efforts at KVI Groningen and Legnaro will be among those summarized. Contributions to the multidisciplinary field of trace analysis will be left...

  11. Neutral particles identification at LHCb

    CERN Multimedia

    Quintana, Boris Julien

    2018-01-01

    Important analyses of the core LHCb physics program rely on calorimetry to identify photons, high-energy neutral pions and electrons. For this purpose, the LHCb calorimeter system is composed of a scintillating pad plane, a preshower detector, an electromagnetic and a hadronic sampling calorimeters. The interaction of a given particle in these detectors leaves a specific signature. This is exploited for particle identification (PID) by combining calorimeters and tracking information into multi-variate classifiers. In this contribution, we focus on the identification of photons against high-energy neutral pion and hadronic backgrounds. Performance on Run 1 data will be shown. Small discrepancies with simulation predictions are then discussed, with special emphasis on the methods to correctly estimate PID cut efficiencies by means of large calibration samples of abundant beauty and charm decays to final states with photons. Finally, the technical aspects of the collection of these samples in Run 2 are presented...

  12. Organophosphorus flame retardants and heavy metals in municipal landfill leachate treatment system in Guangzhou, China.

    Science.gov (United States)

    Deng, Mingjun; Kuo, Dave T F; Wu, Qihang; Zhang, Ying; Liu, Xinyu; Liu, Shengyu; Hu, Xiaodong; Mai, Bixian; Liu, Zhineng; Zhang, Haozhi

    2018-05-01

    The occurrence, distribution and removal efficiencies of organophosphorus flame retardants (OPFRs) and metals were examined in a municipal landfill leachate treatment system in Guangzhou, China. Five OPFRs and thirty-five metals were detected in wastewater samples collected at different treatment stages. ∑OPFRs was reduced from 4807.02 ng L -1 to 103.91 ng L -1 through the treatment system, with close to 98% removed from the dissolved phase. Tris(clorisopropyl) phosphates (TCPPs) dominated through the treatment process and accounted for over 80% and 50% of ∑OPFRs at the influent and the effluent, respectively. TCPPs were most efficiently removed (98.6%) followed by tris(2-chloroethyl) phosphate (TCEP) (96.6%) and triphenyl phosphate (TPP) (88.5%). For metals, Fe, Cr, and Rb were dominant in the raw leachate, detected at 7.55, 2.82, and 4.50 mg L -1 , respectively. Thirteen regulated heavy metals - including eight major pollutants (i.e., As. Cd, Cr, Cu, Hg, Ni, Pb, and Zn) - have been detected in all wastewater samples at sub-mg L -1 levels. Over 99.5% removal was achieved for Cr, Ni, and Fe, and close to 95% removal efficiency was observed for Rb. For the eight major heavy metals, over 99% removal was observed; the only exception was Cu, which was removed at 89%. It was found that microfiltration/reverse osmosis was critical for the removal of OPFRs and heavy metals while the core biological treatment played a minor role towards their removal. Remobilization of Co, Cu, Fe, Hg, Mn, Ni, Sb, and Sr from the returned sludge occurred during the second denitrification, indicating the need for additional post-biological process for effective removal of both contaminants. This study highlights the critical need to develop cheap, effective treatment technologies for contaminants-laden leachate generated from open dumps and under-designed landfills. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Distinct patterns of gene and protein expression elicited by organophosphorus pesticides in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Dennis William E

    2009-04-01

    Full Text Available Abstract Background The wide use of organophosphorus (OP pesticides makes them an important public health concern. Persistent effects of exposure and the mechanism of neuronal degeneration are continuing issues in OP toxicology. To elucidate early steps in the mechanisms of OP toxicity, we studied alterations in global gene and protein expression in Caenorhabditis elegans exposed to OPs using microarrays and mass spectrometry. We tested two structurally distinct OPs (dichlorvos and fenamiphos and employed a mechanistically different third neurotoxicant, mefloquine, as an out-group for analysis. Treatment levels used concentrations of chemical sufficient to prevent the development of 10%, 50% or 90% of mid-vulval L4 larvae into early gravid adults (EGA at 24 h after exposure in a defined, bacteria-free medium. Results After 8 h of exposure, the expression of 87 genes responded specifically to OP treatment. The abundance of 34 proteins also changed in OP-exposed worms. Many of the genes and proteins affected by the OPs are expressed in neuronal and muscle tissues and are involved in lipid metabolism, cell adhesion, apoptosis/cell death, and detoxification. Twenty-two genes were differentially affected by the two OPs; a large proportion of these genes encode cytochrome P450s, UDP-glucuronosyl/UDP-glucosyltransferases, or P-glycoproteins. The abundance of transcripts and the proteins they encode were well correlated. Conclusion Exposure to OPs elicits a pattern of changes in gene expression in exposed worms distinct from that of the unrelated neurotoxicant, mefloquine. The functional roles and the tissue location of the genes and proteins whose expression is modulated in response to exposure is consistent with the known effects of OPs, including damage to muscle due to persistent hypercontraction, neuronal cell death, and phase I and phase II detoxification. Further, the two different OPs evoked distinguishable changes in gene expression; about half

  14. Tracing organophosphorus and brominated flame retardants and plasticizers in an estuarine food web.

    Science.gov (United States)

    Brandsma, Sicco H; Leonards, Pim E G; Leslie, Heather A; de Boer, Jacob

    2015-02-01

    Nine organophosphorus flame retardants (PFRs) were detected in a pelagic and benthic food web of the Western Scheldt estuary, The Netherlands. Concentrations of several PFRs were an order of magnitude higher than those of the brominated flame retardants (BFRs). However, the detection frequency of the PFRs (6-56%) was lower than that of the BFRs (50-97%). Tris(2-butoxyethyl) phosphate (TBOEP), tris(isobutyl) phosphate (TIBP) and tris(2-chloroisopropyl) phosphate (TCIPP) were the dominant PFRs in sediment with median concentrations of 7.0, 8.1 and 1.8 ng/g dry weight (dw), respectively. PFR levels in the suspended particular matter (SPM) were 2-12 times higher than that in sediment. TBOEP, TCIPP, TIBP, tris(2-chloroethyl) phosphate (TCEP) and tris(phenyl) phosphate (TPHP) were found in organisms higher in the estuarine food web. The highest PFR concentrations in the benthic food web were found in sculpin, goby and lugworm with median concentrations of 17, 7.4, 4.6 and 2.0 ng/g wet weight (ww) for TBOEP, TIBP, TCIPP and TPHP, respectively. Comparable levels were observed in the pelagic food web, BDE209 was the predominant PBDE in sediment and SPM with median concentrations up to 9.7 and 385 ng/g dw, respectively. BDE47 was predominant in the biotic compartment of the food web with highest median levels observed in sculpin and common tern eggs of 79 ng/g lipid weight (lw) (2.5 ng/g ww) and 80 ng/g lw (11 ng/g ww), respectively. Trophic magnification was observed for all PBDEs with the exception of BDE209. Indications of trophic magnification of PFRs were observed in the benthic food web for TBOEP, TCIPP and TCEP with tentative trophic magnification factors of 3.5, 2.2 and 2.6, respectively (pwebs. The relative high PFR levels in several fish species suggest high emissions and substantial exposure of organisms to PFRs in the Western Scheldt. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Vendor neutral archive in PACS

    International Nuclear Information System (INIS)

    Agarwal, Tapesh Kumar; Sanjeev

    2012-01-01

    An archive is a location containing a collection of records, documents, or other materials of historical importance. An integral part of Picture Archiving and Communication System (PACS) is archiving. When a hospital needs to migrate a PACS vendor, the complete earlier data need to be migrated in the format of the newly procured PACS. It is both time and money consuming. To address this issue, the new concept of vendor neutral archive (VNA) has emerged. A VNA simply decouples the PACS and workstations at the archival layer. This is achieved by developing an application engine that receives, integrates, and transmits the data using the different syntax of a Digital Imaging and Communication in Medicine (DICOM) format. Transferring the data belonging to the old PACS to a new one is performed by a process called migration of data. In VNA, a number of different data migration techniques are available to facilitate transfer from the old PACS to the new one, the choice depending on the speed of migration and the importance of data. The techniques include simple DICOM migration, prefetch-based DICOM migration, medium migration, and the expensive non-DICOM migration. “Vendor neutral” may not be a suitable term, and “architecture neutral,” “PACS neutral,” “content neutral,” or “third-party neutral” are probably better and preferred terms. Notwithstanding this, the VNA acronym has come to stay in both the medical IT user terminology and in vendor nomenclature, and radiologists need to be aware of its impact in PACS across the globe

  16. Electromagnetic disturbance neutralizing radiation detector

    International Nuclear Information System (INIS)

    Gripentog, W.G.

    1975-01-01

    A radiation detector of the Neher-White type is described which automatically neutralizes induced negative charges on the electrometer tube control grid which shut off the electrometer tube. The detector includes means for establishing a voltage of one polarity in response to plate current and voltage of opposite polarity in response to an absence of plate current and means for connecting the control grid to a reference potential for draining the negative charge in response to the voltage of opposite polarity. (author)

  17. Steady state neutral beam injector

    International Nuclear Information System (INIS)

    Mattoo, S.K.; Bandyopadhyay, M.; Baruah, U.K.; Bisai, N.; Chakbraborty, A.K.; Chakrapani, Ch.; Jana, M.R.; Bajpai, M.; Jaykumar, P.K.; Patel, D.; Patel, G.; Patel, P.J.; Prahlad, V.; Rao, N.V.M.; Rotti, C.; Singh, N.P.; Sridhar, B.

    2000-01-01

    Learning from operational reliability of neutral beam injectors in particular and various heating schemes including RF in general on TFTR, JET, JT-60, it has become clear that neutral beam injectors may find a greater role assigned to them for maintaining the plasma in steady state devices under construction. Many technological solutions, integrated in the present day generation of injectors have given rise to capability of producing multimegawatt power at many tens of kV. They have already operated for integrated time >10 5 S without deterioration in the performance. However, a new generation of injectors for steady state devices have to address to some basic issues. They stem from material erosion under particle bombardment, heat transfer > 10 MW/m 2 , frequent regeneration of cryopanels, inertial power supplies, data acquisition and control of large volume of data. Some of these engineering issues have been addressed to in the proposed neutral beam injector for SST-1 at our institute; the remaining shall have to wait for the inputs of the database generated from the actual experience with steady state injectors. (author)

  18. Neutral beams for magnetic fusion

    International Nuclear Information System (INIS)

    Hooper, B.

    1977-01-01

    Significant advances in forming energetic beams of neutral hydrogen and deuterium atoms have led to a breakthrough in magnetic fusion: neutral beams are now heating plasmas to thermonuclear temperatures, here at LLL and at other laboratories. For example, in our 2XIIB experiment we have injected a 500-A-equivalent current of neutral deuterium atoms at an average energy of 18 keV, producing a dense plasma (10 14 particles/cm 3 ) at thermonuclear energy (14 keV or 160 million kelvins). Currently, LLL and LBL are developing beam energies in the 80- to 120-keV range for our upcoming MFTF experiment, for the TFTR tokamak experiment at Princeton, and for the Doublet III tokamak experiment at General Atomic. These results increase our long-range prospects of producing high-intensity beams of energies in the hundreds or even thousands of kilo-electron-volts, providing us with optimistic extrapolations for realizing power-producing fusion reactors

  19. Analysis of monomeric and oligomeric organophosphorus flame retardants in fish muscle tissues using liquid chromatography–electrospray ionization tandem mass spectrometry: Application to Nile tilapia (Oreochromis niloticus) from an e-waste processing area in northern Vietnam

    OpenAIRE

    Matsukami, Hidenori; Suzuki, Go; Tue, Nguyen Minh; Tuyen, Le Huu; Viet, Pham Hung; Takahashi, Shin; Tanabe, Shinsuke; Takigami, Hidetaka

    2016-01-01

    Using electrospray ionization tandem mass spectrometry combined with liquid chromatography (LC), a novel analytical method was developed to quantify eight monomeric organophosphorus flame retardants (m-PFRs) and three oligomeric organophosphorus flame retardants (o-PFRs) in fish muscle samples. The optimization and validation experiments indicate that the developed method can determine accurately the concentrations of analytes in fish muscle samples. The recoveries of analytes in fish muscle ...

  20. Plasma/Neutral-Beam Etching Apparatus

    Science.gov (United States)

    Langer, William; Cohen, Samuel; Cuthbertson, John; Manos, Dennis; Motley, Robert

    1989-01-01

    Energies of neutral particles controllable. Apparatus developed to produce intense beams of reactant atoms for simulating low-Earth-orbit oxygen erosion, for studying beam-gas collisions, and for etching semiconductor substrates. Neutral beam formed by neutralization and reflection of accelerated plasma on metal plate. Plasma ejected from coaxial plasma gun toward neutralizing plate, where turned into beam of atoms or molecules and aimed at substrate to be etched.

  1. The Neutral Interest Rate: Estimates for Chile

    OpenAIRE

    Rodrigo Fuentes S; Fabián Gredig U.

    2008-01-01

    To estimate the neutral real interest rate for Chile, we use a variety of methods that can be classified into three categories: those derived from economic theory, the neutral rate implicit in financial assets, and statistical procedures using macroeconomic data. We conclude that the neutral rate is not constant over time, but it is closely related with—though not equivalent to—the potential GDP growth rate. The application of the different methods yields fairly similar results. The neutral r...

  2. Neutrality in mediation: an ambiguous ethical value

    OpenAIRE

    Bailey, Paul

    2014-01-01

    Mediator neutrality would appear, by definition, to be a necessary and required ethical principle for all mediators to practice. But what is meant by neutrality in mediation? Is it practically possible to be completely neutral between parties in mediation while at the same time being fair to both of them? This paper attempts to answer these two questions.

  3. Ion-beam Plasma Neutralization Interaction Images

    International Nuclear Information System (INIS)

    Igor D. Kaganovich; Edward Startsev; S. Klasky; Ronald C. Davidson

    2002-04-01

    Neutralization of the ion beam charge and current is an important scientific issue for many practical applications. The process of ion beam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ion beam pulse are presented

  4. Ion-beam Plasma Neutralization Interaction Images

    Energy Technology Data Exchange (ETDEWEB)

    Igor D. Kaganovich; Edward Startsev; S. Klasky; Ronald C. Davidson

    2002-04-09

    Neutralization of the ion beam charge and current is an important scientific issue for many practical applications. The process of ion beam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ion beam pulse are presented.

  5. The Net Neutrality Debate: The Basics

    Science.gov (United States)

    Greenfield, Rich

    2006-01-01

    Rich Greenfield examines the basics of today's net neutrality debate that is likely to be an ongoing issue for society. Greenfield states the problems inherent in the definition of "net neutrality" used by Common Cause: "Network neutrality is the principle that Internet users should be able to access any web content they choose and…

  6. Compostos organofosforados pentavalentes: histórico, métodos sintéticos de preparação e aplicações como inseticidas e agentes antitumorais Organophosphorus pentavalent compounds: history, synthetic methods of preparation and application as insecticides and antitumor agents

    Directory of Open Access Journals (Sweden)

    Viviane Martins Rebello dos Santos

    2007-02-01

    Full Text Available This paper is a review of the history, synthesis and application of organophosphorus compounds, especially of those of pentavalent phosphorus, such as phosphoramidates, phosphorothioates, phosphonates and phosphonic acids with insecticide and anticancer activities. The organophosphorus compounds with agrochemical applications show great structural variety, They include not only insecticides, but also fungicides, herbicides, and others. The large variety of commercially available organophosphorus pesticides is remarkable. Even more interesting is the high efficiency of some organophosphorus compounds as anticancer agents such as cyclophosphamide and its derivatives.

  7. Degradation of Organophosphorus Pesticides in Water during UV/H2O2 Treatment: Role of Sulphate and Bicarbonate Ions

    Directory of Open Access Journals (Sweden)

    Am Fadaei

    2012-01-01

    Full Text Available The photodegradation of two organophosphorus pesticides, malathian and diazinon, by sulfate radicals and bicarbonate radicals in aqueous solution were studied. The effect of the operational parameters such as pH, salt concentration, water type, H2O2 concentration and initial concentration of pesticides was studied. Gas chromatography mass spectroscopy (GC–MS was used for analyses of pesticides. When salt effect was studied, it was found that sodium bicarbonate was the most powerful inhibitor used, while sodium sulfate was the weakest one. The highest degradation in UV/H2O2 process for malathion was found in alkaline condition and for diazinon in acidic condition. The photodegradation in all waters used in this work exhibited first order kinetics. Photodegradation rate in distilled water was higher than real water. The degradation of pesticides increased with increasing of H2O2 concentration.

  8. Effect of two organophosphorus insecticides on the growth, respiration and (/sup 14/C)-glucose metabolism of Azobacter chroococcum Beij

    Energy Technology Data Exchange (ETDEWEB)

    Balasubramanian, A; Narayanan, R [Tamil Nadu Agricultural Univ., Coimbatore (India)

    1980-01-01

    The two organophosphorus insecticides, commonly applied to soil, viz., disulfoton (0,0-diethyl S-2-ethyl thio ethyl phosphorodithioate) and fensulfothion (0,0-diethyl 0-4-methyl sulphinyl phenyl phosphorothioate) did not affect the in vitro growth of Azotobacter chroococcum Beij., the free-living, nitrogen fixing soil bacterium, at 2 ppm (lower level), while the normal dose (5 ppm) and the higher level (10 ppm) suppressed the growth. Respiration of the organism (glucose oxidation) was adversely affected by the insecticides in the growth medium and the inhibition increased with the concentration of the chemical. Both the insecticides suppressed the assimilation of (/sup 14/C)-glucose in the cold-TCA soluble, hot-TCA soluble fractions and insoluble residue of the cells whereas the /sup 14/C-incorporation in the alcohol soluble and alcohol-ether soluble fractions was enhanced indicating that the insecticides considerably altered the glucose metabolism of the bacterium.

  9. [How aliphatic alcohols and ph affect reactional capability of the horse blood serum cholinesterase at its interaction with organophosphorus inhibitors].

    Science.gov (United States)

    Basova, N E; Kormilitsin, B N; Perchenok, A Iu; Rozengart, E V; Saakov, V S; Suvorov, A A

    2013-01-01

    There was studied action of aliphatic alcohols (ethanol, propanol, isopropanol, n-butanol, isobutanol, secbutanol, tretbetanol) and pH on various kinds of reactional capability the serum cholinesterase. At the alcohols-affected inhibition of the cholinesterase hydrolytic activity, the determining role was played not the total number carbon atoms in the alcohol molecule, but by the "effective length" of the carbohydrate chain. The fact that the presence of alcohols did not affect parameters of the reverse cholinesterase inhibition with onium ions tetramethylammonium and choline allows suggesting the absence of effect solvents on specific acetylcholine sorption in the enzyme active center. With aid of two rows of hydrophobic organophosphorus inhibitors (OPI), we have managed to estimate both the degree and the character itself of the modifying action of alcohols and pH on the process of irreversible inhibition of serum cholinesterase.

  10. [Comparative analysis of sensitivity of proteases (chymotrypsin and trypsin) and cholinesterases of different origin to some organophosphorus inhibitors].

    Science.gov (United States)

    Rozengart, E V

    2009-01-01

    The antichymotrypsin, antitrypsin, and anticholinesterase efficiencies of four homologous series of organophosphorus inhibitors are compared: O-ethyl-S-(n-alkyl)methylthiophosphonates, O-(n-alkyl)-S-(n-butyl)methylthiophosphonates, O-(n-alkyl)-S-beta-(ethylmercaptoethylene)methylthiophosphonates, and their methylsulfomethylates. As sources of a-chymotrypsin and trypsin, commercial compounds of Worthington Biochemical Corporation and Leningrad Myasokombinat were tested. Bimolecular constant of the reaction rate was used as the measure of antienzyme efficiency. In all cases, the antichymotrypsin efficiency was lower, while the antitrypsin--essentially higher than the anticholinesterase activity of the studied inhibitors. These differences were found to much depend both on the inhibitor structure and on nature of the cholinesterase compounds.

  11. Towards a Capacitive Enzyme Sensor for Direct Determination of Organophosphorus Pesticides: Fundamental Studies and Aspects of Development

    Directory of Open Access Journals (Sweden)

    Ashok Mulchandani

    2003-06-01

    Full Text Available The realisation of a miniaturised potentiometric enzyme biosensor is presented. The biosensor chip utilises the enzyme organophosphorus hydrolase (OPH for the direct determination of pesticides. The transducer structure of the sensors chip consists of a pH-sensitive capacitive electrolyte-insulator-semiconductor (EIS structure that reacts towards pH changes caused by the OPH-catalised hydrolysis of the organophosphate compounds. The biosensor is operated versus a conventional Ag/AgCl reference electrode. Measurements were performed in the capacitance/voltage (C/V and the constant capacitance (ConCap mode for the two different pesticides paraoxon and parathion. For the development of this new type of biosensor, different immobilisation strategies, influence of buffer composition and concentration, transducer material, detection limit, long-term stability and selectivity have been studied.

  12. Effect of two organophosphorus insecticides on the growth, respiration and (14C)-glucose metabolism of Azobacter chroococcum Beij

    International Nuclear Information System (INIS)

    Balasubramanian, A.; Narayanan, R.

    1980-01-01

    The two organophosphorus insecticides, commonly applied to soil, viz., disulfoton (0,0-diethyl S-2-ethyl thio ethyl phosphorodithioate) and fensulfothion (0,0-diethyl 0-4-methyl sulphinyl phenyl phosphorothioate) did not affect the in vitro growth of Azotobacter chroococcum Beij., the free-living, nitrogen fixing soil bacterium, at 2 ppm (lower level), while the normal dose (5 ppm) and the higher level (10 ppm) suppressed the growth. Respiration of the organism (glucose oxidation) was adversely affected by the insecticides in the growth medium and the inhibition increased with the concentration of the chemical. Both the insecticides suppressed the assimilation of ( 14 C)-glucose in the cold-TCA soluble, hot-TCA soluble fractions and insoluble residue of the cells whereas the 14 C-incorporation in the alcohol soluble and alcohol-ether soluble fractions was enhanced indicating that the insecticides considerably altered the glucose metabolism of the bacterium. (author)

  13. Advanced neutral-beam technology

    International Nuclear Information System (INIS)

    Berkner, K.H.

    1980-09-01

    Extensive development will be required to achieve the 50- to 75-MW, 175- to 200-keV, 5- to 10-sec pulses of deuterium atoms envisioned for ETF and INTOR. Multi-megawatt injector systems are large (and expansive); they consist of large vacuum tanks with many square meters of cryogenic pumping panels, beam dumps capable of dissipating several megawatts of un-neutralized beam, bending magnets, electrical power systems capable of fast turnoff with low (capacity) stored energy, and, of course, the injector modules (ion sources and accelerators). The technology requirements associated with these components are described

  14. Electrophysiologic changes following treatment with organophosphorus-induced delayed neuropathy-producing agents in the adult hen.

    Science.gov (United States)

    Robertson, D G; Schwab, B W; Sills, R D; Richardson, R J; Anderson, R J

    1987-03-15

    Although clinical, pathological, and biochemical effects of organophosphorus-induced delayed neuropathy (OPIDN) have been intensively investigated in the adult hen, detailed electrophysiological studies are lacking. Adult white leghorn hens were treated with a single oral dose of either 30 mg/kg tri-2-cresyl phosphate (TOCP), 750 mg/kg TOCP, 4 mg/kg di-n-butyl-2,2-dichlorovinyl phosphate (DBCV), or 30 mg/kg di-n-butyl-2,2-dichlorovinyl phosphinate (DBCV-P). The 750 mg/kg TOCP and DBCV, but not the 30 mg/kg TOCP and DBCV-P, treatments resulted in clinical signs of OPIDN and mild to marked damage of the tibial nerve 21 days after dose. Twenty-four hr lymphocyte neurotoxic esterase (NTE) inhibition was used as an index of brain NTE inhibition for the various organophosphorus compound (OP) treatment. Twenty-four hr lymphocyte NTE inhibition for 30 mg/kg TOCP, 750 mg/kg TOCP, DBCV, and DBCV-P was 54.1, 87.1, 84.8, and 68.3%, respectively. Twenty-one days after dose, the TOCP-treated hens exhibited some abnormalities in conduction velocity and action potential duration in the tibial or sciatic nerves. No abnormalities were observed in action potential parameters of either the DBCV or DBCV-P treatments. Neurotoxic OP (TOCP and DBCV) treatment resulted in decreased refractoriness in the tibial nerve, increased refractoriness in the sciatic nerve, and elevated strength duration threshold for both nerves. These changes were not present in nerves from DBCV-P (a non-neurotoxic NTE inhibitor)-treated hens. These results suggest that refractory period and strength duration abnormalities in peripheral nerve correlate well with the production of OPIDN and are evident without coincident clinical signs or histopathology.

  15. Determination of no-observed effect level (NOEL-biomarker equivalents to interpret biomonitoring data for organophosphorus pesticides in children

    Directory of Open Access Journals (Sweden)

    Bouchard Michèle

    2009-02-01

    Full Text Available Abstract Background Environmental exposure to organophosphorus pesticides has been characterized in various populations, but interpretation of these data from a health risk perspective remains an issue. The current paper proposes biological reference values to help interpret biomonitoring data related to an exposure to organophosphorus pesticides in children for which measurements of alkylphosphate metabolites are available. Methods Published models describing the kinetics of malathion and chlorpyrifos in humans were used to determine no-observed effect level – biomarker equivalents for methylphosphates and ethylphosphates, respectively. These were expressed in the form of cumulative urinary amounts of alkylphosphates over specified time periods corresponding to an absorbed no-observed effect level dose (derived from a published human exposure dose and assuming various plausible exposure scenarios. Cumulative amounts of methylphosphate and ethylphosphate metabolites measured in the urine of a group of Quebec children were then compared to the proposed biological reference values. Results From a published no-observed effect level dose for malathion and chlorpyrifos, the model predicts corresponding oral biological reference values for methylphosphate and ethylphosphate derivatives of 106 and 52 nmol/kg of body weight, respectively, in 12-h nighttime urine collections, and dermal biological reference values of 40 and 32 nmol/kg of body weight. Out of the 442 available urine samples, only one presented a methylphosphate excretion exceeding the biological reference value established on the basis of a dermal exposure scenario and none of the methylphosphate and ethylphosphate excretion values were above the obtained oral biological reference values, which reflect the main exposure route in children. Conclusion This study is a first step towards the development of biological guidelines for organophophorus pesticides using a toxicokinetic modeling

  16. Determination of some organophosphorus pesticides in water and watermelon samples by microextraction prior to high-performance liquid chromatography.

    Science.gov (United States)

    Wang, Chun; Wu, Qiuhua; Wu, Chunxia; Wang, Zhi

    2011-11-01

    A novel method based on simultaneous liquid-liquid microextraction and carbon nanotube reinforced hollow fiber microporous membrane solid-liquid phase microextraction has been developed for the determination of six organophosphorus pesticides, i.e. isocarbophos, phosmet, parathion-methyl, triazophos, fonofos and phoxim, in water and watermelon samples prior to high-performance liquid chromatography (HPLC). Under the optimum conditions, the method shows a good linearity within a range of 1-200 ng/mL for water samples and 5-200 ng/g for watermelon samples, with the correlation coefficients (r) varying from 0.9990 to 0.9997 and 0.9986 to 0.9995, respectively. The limits of detection (LODs) were in the range between 0.1 and 0.3 ng/mL for water samples and between 1.0 and 1.5 ng/g for watermelon samples. The recoveries of the method at spiking levels of 5.0 and 50.0 ng/mL for water samples were between 85.4 and 100.8%, and at spiking levels of 5.0 and 50.0 ng/g for watermelon samples, they were between 82.6 and 92.4%, with the relative standard deviations (RSDs) varying from 4.5-6.9% and 5.2-7.4%, respectively. The results suggested that the developed method represents a simple, low-cost, high analytes preconcentration and excellent sample cleanup procedure for the determination of organophosphorus pesticides in water and watermelon samples. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. In vitro study of the neuropathic potential of the organophosphorus compounds fenamiphos and profenofos: Comparison with mipafox and paraoxon.

    Science.gov (United States)

    Emerick, Guilherme L; Fernandes, Laís S; de Paula, Eloísa Silva; Barbosa, Fernando; dos Santos, Neife Aparecida Guinaim; dos Santos, Antonio Cardozo

    2015-08-01

    Organophosphorus-induced delayed neuropathy (OPIDN) is a central-peripheral distal axonopathy that develops 8-14 days after poisoning by a neuropathic organophosphorus compound (OP). Several OPs that caused OPIDN were withdrawn from the agricultural market due to induction of serious delayed effects. Therefore, the development of in vitro screenings able to differentiate neuropathic from non-neuropathic OPs is of crucial importance. Thus, the aim of this study was to evaluate the differences in the neurotoxic effects of mipafox (neuropathic OP) and paraoxon (non-neuropathic OP) in SH-SY5Y human neuroblastoma cells, using the inhibition and aging of neuropathy target esterase (NTE), inhibition of acetylcholinesterase (AChE), activation of calpain, neurite outgrowth, cytotoxicity and intracellular calcium as indicators. Additionally, the potential of fenamiphos and profenofos to cause acute and/or delayed effects was also evaluated. Mipafox had the lowest IC50 and induced the highest percentage of aging of NTE among the OPs evaluated. Only mipafox was able to cause calpain activation after 24 h of incubation. Concentrations of mipafox and fenamiphos which inhibited at least 70% of NTE were also able to reduce neurite outgrowth. Cytotoxicity was higher in non-neuropathic than in neuropathic OPs while the intracellular calcium levels were higher in neuropathic than in non-neuropathic OPs. In conclusion, the SH-SY5Y cellular model was selective to differentiate neuropathic from non-neuropathic OPs; fenamiphos, but not profenofos presented results compatible with the induction of OPIDN. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Rapid simultaneous determination of organophosphorus pesticides in human serum and urine by liquid chromatography-mass spectrometry

    Directory of Open Access Journals (Sweden)

    Zlatković Milica

    2010-01-01

    Full Text Available Background/Aim. Analysis of organophosphosphorus compounds and their metabolites in a biological material includes the use of numerous methods, covering both preparation of samples for analysis and their identification that is considered to be very complex. Low concentrations monitoring requires implementation of highly sensitive analytical techniques. The aim of this study was to develop and validate an original and sensitive method for the detection and quantitation of organophosphorus pesticides (dimethoate, diazinon, malathion and malaoxon in human biological matrices (serum, urine. Methods. This method was based on a solid-phase extraction procedure, a chromatographic separation using an ACQUITY UPLC ® HSST3 column and mass spectrometric detection in the positve ion mode. Mobile phase: was consited of Solvent A (5 mM ammonium formate pH 3.0 and Solvent B (0.1% acetic formate in methanol, in a linear gradient (constant flow-rate 0.3 mL/min. Results. The standard curve was linear in the range of 0.05-5.00 mg/L for malathion and malaoxon, 0.10-5.00 mg/L for dimethoate and 0.05-2.50 mg/L for diazinon. The correlation coefficient was r ≥ 0.99. Extraction recoveries were satisfactory and ranged between 90-99%. The limits of detection (LOD was between 0.007- 0.07 mg/L and the limits of quantitation (LOQ ranged between 0.022-0.085 mg/L. Intra- and interassay precision and accuracy were satisfactory for all of the pesticides analyzed. Conclusion. The method of liquid chromatography - mass spectrometry is simple, accurate, and useful for the determination of organophosphorus pesticides in both clinical and forensic toxicology.

  19. Plasma neutralizers for H- or D- beams

    International Nuclear Information System (INIS)

    Berkner, K.H.; Pyle, R.V.; Savas, S.E.; Stalder, K.R.

    1980-10-01

    Plasma neutralizers can produce higher conversion efficiencies than are obtainable with gas neutralizers for the production of high-energy neutral beams from negative hydrogen ions. Little attention has been paid to experimental neutralizer studies because of the more critical problems connected with the development of negative-ion sources. With the prospect of accelerating ampere dc beams from extrapolatable ion sources some time next year, we are re-examining plasma neutralizers. Some basic considerations, two introductory experiments, and a next-step experiment are described

  20. ORNL positive ion neutral beam program

    International Nuclear Information System (INIS)

    Whealton, J.H.; Haselton, H.H.; Barber, G.C.

    1978-01-01

    The neutral beam group at Oak Ridge National Laboratory has constructed neutral beam generators for the ORMAK and PLT devices, is presently constructing neutral beam devices for the ISX and PDX devices, and is contemplating the construction of neutral beam systems for the advanced TNS device. These neutral beam devices stem from the pioneering work on ion sources of G. G. Kelley and O. B. Morgan. We describe the ion sources under development at this Laboratory, the beam optics exhibited by these sources, as well as some theoretical considerations, and finally the remainder of the beamline design

  1. Discrete symmetries with neutral mesons

    Science.gov (United States)

    Bernabéu, José

    2018-01-01

    Symmetries, and Symmetry Breakings, in the Laws of Physics play a crucial role in Fundamental Science. Parity and Charge Conjugation Violations prompted the consideration of Chiral Fields in the construction of the Standard Model, whereas CP-Violation needed at least three families of Quarks leading to Flavour Physics. In this Lecture I discuss the Conceptual Basis and the present experimental results for a Direct Evidence of Separate Reversal-in-Time T, CP and CPT Genuine Asymmetries in Decaying Particles like Neutral Meson Transitions, using Quantum Entanglement and the Decay as a Filtering Measurement. The eight transitions associated to the Flavour-CP eigenstate decay products of entangled neutral mesons have demonstrated with impressive significance a separate evidence of TRV and CPV in Bd-physics, whereas a CPTV asymmetry shows a 2σ effect interpreted as an upper limit. Novel CPTV observables are discussed for K physics at KLOE-2, including the difference between the semileptonic asymmetries from KL and KS, the ratios of double decay rate Intensities to Flavour-CP eigenstate decay products and the ω-effect. Their observation would lead to a change of paradigm beyond Quantum Field Theory, however there is nothing in Quantum Mechanics forbidding CPTV.

  2. A SAW-Based Chemical Sensor for Detecting Sulfur-Containing Organophosphorus Compounds Using a Two-Step Self-Assembly and Molecular Imprinting Technology

    Directory of Open Access Journals (Sweden)

    Yong Pan

    2014-05-01

    Full Text Available This paper presents a new effective approach for the sensitive film deposition of surface acoustic wave (SAW chemical sensors for detecting organophosphorus compounds such as O-ethyl-S-2-diisopropylaminoethyl methylphosphonothiolate (VX containing sulfur at extremely low concentrations. To improve the adsorptive efficiency, a two-step technology is proposed for the sensitive film preparation on the SAW delay line utilizing gold electrodes. First, mono[6-deoxy-6-[(mercaptodecamethylenethio

  3. Actinide immobilization in the subsurface environment by in-situ treatment with a hydrolytically unstable organophosphorus complexant: Uranyl uptake by calcium phytate

    International Nuclear Information System (INIS)

    Nash, K.L.; Jensen, M.P.; Schmidt, M.A.

    1997-01-01

    In addition to naturally occurring uranium and thorium, actinide ions exist in the subsurface environment as a result of accidental releases and intentional disposal practices associated with nuclear weapons production. These species present a significant challenge to cost-effective remediation of contaminated environments. An attractive approach to decreasing the probability of actinide migration in the subsurface is to transform the ions into a less mobile form by remote treatment. We have under development a process which relies on a polyfunctional organophosphorus complexant to sequester the mobile metal ions by complexation/cation exchange in the near term, and to subsequently decompose, transforming the actinides into insoluble phosphate mineral forms in the long term. Studies to date include identification of a suitable organophosphorus reagent, profiling of its decomposition kinetics, verification of the formation of phosphate mineral phases upon decomposition of the reagent, and extensive comparison of the actinide uptake ability of the calcium salt of the reagent as compared with hydroxyapatite. In this report, we briefly describe the process with focus on the cation exchange behavior of the calcium salt of the organophosphorus sequestrant

  4. [Feasibility investigation of hydrogen instead of helium as carrier gas in the determination of five organophosphorus pesticides by gas chromatography-mass spectrometry].

    Science.gov (United States)

    Liu, Zhenxue; Zhou, Shixue

    2015-01-01

    Helium is almost the only choosable carrier gas used in gas chromatography-mass spectrometry (GC-MS). A mixed standard solution of five organophosphorus pesticides was analyzed by using GC-MS, and hydrogen or helium as carrier gas, so as to study the feasibility of hydrogen instead of helium as carrier gas for the determination of organophosphorus pesticides. Combining a mass spectrum database built by ourselves, the results were deconvolved and identified by Automated Mass Spectral Deconvolution & Identification System (AMDIS32), a software belonging to the workstation of the instrument. Then, the statistical software, IBM SPSS Statistics 19.0 was used for the clustering analysis of the data. The results indicated that when hydrogen was used as carrier gas, the peaks of the pesticides detected were slightly earlier than those when helium used as carrier gas, but the resolutions of the chromatographic peaks were lower, and the fraction good indices (Frac. Good) were lower, too. When hydrogen was used as carrier gas, the signals of the pesticides were unstable, the measuring accuracies of the pesticides were reduced too, and even more, some compounds were undetectable. Therefore, considering the measuring accuracy, the signal stability, and the safety, etc., hydrogen should be cautiously used as carrier gas in the determination of organophosphorus pesticides by GC-MS.

  5. Comparison of the Efficiency of Simultaneous Application of UV/O3 for the Removal of Organophosphorus and Carbamat Pesticides in Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Mohammad Taghi Samadi

    2010-03-01

    Full Text Available A vast variety of pesticides are used for agricultural pests in Iran. The release of these persistent organic pollutants. into water supplies leaves adverse effects on both the environment and public health. Advanced oxidation processes have been used recently for pesticide removal. In this research, the combined UV/O3 process has been investigated for the removal of organophosphorus pesticides (Diazinon, Chlorpyrifos, Carbamate pesticides (carbaryl. In this survey, samples have been prepared by adding given concentration (1, 5, 10, 15, 20 mg/L of the pesticides to deionized water. The samples at separation periods were exposed to the combined UV/O3 (UV=50-200 Wm-2 and O3 = 1g hr-1in a bath  reactor at different pH levels (6, 7, 9 and for different contact times (0.5,1,1.5,2 hr and the removal efficiencies were determined. Residual concentrations were determined using GC/MS/MS and HPLC.  Based on the results, increasing pH reduced pesticide concentration and increased contact time had a direct effect on enhancing removal efficiency. The combined UV/O3 process was found to have a high efficiency (>80% in degrading both halogenated Organophosphorus(Chlorpyrifos and non- halogenated Organophosphorus (Diazinon pesticides. Its removal efficiency for degrading carbamate pesticide (Carbari was found to be >90%. Based on our results, this method may be suggested for the removal of pesticides from aqueous solutions.

  6. Happy birthday, little neutral one

    International Nuclear Information System (INIS)

    Sutton, C.

    1990-01-01

    This article looks at the history of the neutrino particle, a tiny neutral particle which reacts only with the weak force. Its existence was originally postulated by Wolfgang Pauli in 1930, to explain beta decay energy conservation but because of the extreme experimental difficulties involved, neutrinos were not observed experimentally until 1956. Notwithstanding this the neutrino has become a valuable tool in high energy physics. Neutrino beams are used to probe matter and were used to reveal the existence of quarks within the particles once viewed as elementary, the proton and neutron. Cosmic neutrinos may be detected in the Deep Underwater Muon and Neutrino Detector off the coast of Hawaii and the Moon itself is a target for ultra high energy neutrinos in a Russian experiment to detect cascades of charge particles produced by these neutrinos in ice in the Antarctic. (UK)

  7. Gargamelle and the neutral currents

    International Nuclear Information System (INIS)

    Rousset, A.

    1996-06-01

    In order to simplify the description of forces, the physicists want to reduce the number of four interactions to a smaller one. They want to unify them. Einstein tried to unify the electromagnetic interaction and the gravitation interaction but it was probably the most difficult to unify. during the sixties, the American physicists Sheldon Glashow and Steven Weinberg and the Pakistani Abdus Salam ( each rewarded by the Nobel price of 1979) propose to unify the weak and electromagnetic interactions interactions under the form of an only interaction, the electro-weak interaction. To check the validity of this theory exist the demonstration by the weak neutral currents. In 1973, European physicians which analyzed photos taken in the bubble chamber called Gargamelle brought the experimental proof. This book tells the story of this discovery. (N.C.)

  8. $\\tau$ decays with neutral kaons

    CERN Document Server

    Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Anderson, K.J.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Bailey, I.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Batley, J.R.; Baumann, S.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bloodworth, I.J.; Bock, P.; Bohme, J.; Boeriu, O.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couchman, J.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Dallison, S.; Davis, R.; de Roeck, A.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Feld, L.; Ferrari, P.; Fiedler, F.; Fierro, M.; Fleck, I.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Hargrove, C.K.; Harin-Dirac, M.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hobson, P.R.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klier, A.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kupper, M.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lauber, J.; Lawson, I.; Layter, J.G.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; Lillich, J.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Marchant, T.E.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Merritt, F.S.; Mes, H.; Meyer, I.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Przybycien, M.; Quadt, A.; Rembser, C.; Rick, H.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Trefzger, T.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Zacek, V.; Zer-Zion, D.

    2000-01-01

    The branching ratio of the tau lepton to a neutral K meson is measured from a sample of approximately 200,000 tau decays recorded by the OPAL detector at centre-of-mass energies near the Z0 resonance. The measurement is based on two samples which identify one-prong tau decays with KL and KS mesons. The combined branching ratios are measured to be B(tau- -->pi- K0bar nutau) = (9.33+-0.68+-0.49)x10^-3 B(tau- -->pi- K0bar [>=1pi0] nutau) = (3.24+-0.74+-0.66)x10^-3 B(tau- -->K- K0bar [>=0pi0] nutau) = (3.30+-0.55+-0.39)x10^-3 where the first error is statistical and the second systematic.

  9. Laser sputter neutral mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    King, B V; Clarke, M; Hu, H; Betz, [Newcastle Univ., NSW (Australia). Dept. of Physics

    1994-12-31

    Laser sputter neutral mass spectrometry (LSNMS) is an emerging technique for highly sensitive surface analysis. In this technique a target is bombarded with a pulsed beam of keV ions. The sputtered particles are intercepted by a high intensity pulsed laser beam above the surface and ionised with almost 100% efficiency. The photions may then be mass analysed using a quadrupole or, more commonly, using time of flight (TOF) techniques. In this method photoions are extracted from the ionisation region, accelerated to a known energy E{sub o} and strike a channelplate detector a distance `d` away. The flight time `t` of the photoions is then related to their mass by `d` {radical}m / {radical} 2E{sub o} so measurement of `t` allows mass spectra to be obtained. It is found that LSNMS is an emerging technique of great sensitivity and flexibility, useful for both applied analysis and to investigate basic sputtering processes. 4 refs., 3 figs.

  10. Laser sputter neutral mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    King, B.V.; Clarke, M.; Hu, H.; Betz [Newcastle Univ., NSW (Australia). Dept. of Physics

    1993-12-31

    Laser sputter neutral mass spectrometry (LSNMS) is an emerging technique for highly sensitive surface analysis. In this technique a target is bombarded with a pulsed beam of keV ions. The sputtered particles are intercepted by a high intensity pulsed laser beam above the surface and ionised with almost 100% efficiency. The photions may then be mass analysed using a quadrupole or, more commonly, using time of flight (TOF) techniques. In this method photoions are extracted from the ionisation region, accelerated to a known energy E{sub o} and strike a channelplate detector a distance `d` away. The flight time `t` of the photoions is then related to their mass by `d` {radical}m / {radical} 2E{sub o} so measurement of `t` allows mass spectra to be obtained. It is found that LSNMS is an emerging technique of great sensitivity and flexibility, useful for both applied analysis and to investigate basic sputtering processes. 4 refs., 3 figs.

  11. TFTR neutral beam power system

    International Nuclear Information System (INIS)

    Deitz, A.; Murray, H.; Winje, R.

    1977-01-01

    The TFTR NB System will be composed of four beam lines, each containing three ion sources presently being developed for TFTR by the Lawrence Berkeley Laboratories (LBL). The Neutral Beam Power System (NBPS) will provide the necessary power required to operate these Ion Sources in both an experimental or operational mode as well as test mode. This paper describes the technical as well as the administrative/management aspects involved in the development and building of this system. The NBPS will combine the aspects of HV pulse (120 kV) and long pulse width (0.5 sec) together to produce a high power system that is unique in the Electrical Engineering field

  12. Modeling Secondary Neutral Helium in the Heliosphere

    International Nuclear Information System (INIS)

    Müller, Hans-Reinhard; Möbius, Eberhard; Wood, Brian E.

    2016-01-01

    An accurate, analytic heliospheric neutral test-particle code for helium atoms from the interstellar medium (ISM) is coupled to global heliospheric models dominated by hydrogen and protons from the solar wind and the ISM. This coupling enables the forward-calculation of secondary helium neutrals from first principles. Secondaries are produced predominantly in the outer heliosheath, upwind of the heliopause, by charge exchange of helium ions with neutral atoms. The forward model integrates the secondary production terms along neutral trajectories and calculates the combined neutral helium phase space density in the innermost heliosphere where it can be related to in-situ observations. The phase space density of the secondary component is lower than that of primary neutral helium, but its presence can change the analysis of primaries and the ISM, and can yield valuable insight into the characteristics of the plasma in the outer heliosheath. (paper)

  13. Molecular clock on a neutral network.

    Science.gov (United States)

    Raval, Alpan

    2007-09-28

    The number of fixed mutations accumulated in an evolving population often displays a variance that is significantly larger than the mean (the overdispersed molecular clock). By examining a generic evolutionary process on a neutral network of high-fitness genotypes, we establish a formalism for computing all cumulants of the full probability distribution of accumulated mutations in terms of graph properties of the neutral network, and use the formalism to prove overdispersion of the molecular clock. We further show that significant overdispersion arises naturally in evolution when the neutral network is highly sparse, exhibits large global fluctuations in neutrality, and small local fluctuations in neutrality. The results are also relevant for elucidating aspects of neutral network topology from empirical measurements of the substitution process.

  14. Neutral particle beam alternative concept for ITER

    International Nuclear Information System (INIS)

    Sedgley, D.; Brook, J.; Luzzi, T.; Deutsch, L.

    1989-01-01

    An analysis of an ITER neutral particle beam system is presented. The analysis covers the neutralizer, ion dumps, pumping, and geometric aspects. The US beam concept for ITER consists of three or four clusters of beamlines delivering approximately 80 MW total of 1.6-MeV deuterium to three or four reactor ports. Each cluster has three self-contained beamlines featuring plasma neutralizers and electrostatic ion dumps. In this study, each of the beamlines has two source assemblies with separate gas neutralizers and magnetic ion dumps. Deuterium is injected into the gas neutralizers by a separate system. Saddle-shaped copper coils augment the tokamak poloidal field to turn the charged particles into the ion dumps. The gas flow from the source, neutralizer, and ion dump is pumped by regenerable cryopanels. The effect of the port between the TF coils and the beam injection angle on the plasma footprint was studied

  15. BEAMS3D Neutral Beam Injection Model

    Energy Technology Data Exchange (ETDEWEB)

    Lazerson, Samuel

    2014-04-14

    With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

  16. Neutral-beam current drive in tokamaks

    International Nuclear Information System (INIS)

    Devoto, R.S.

    1986-01-01

    The theory of neutral-beam current drive in tokamaks is reviewed. Experiments are discussed where neutral beams have been used to drive current directly and also indirectly through neoclassical effects. Application of the theory to an experimental test reactor is described. It is shown that neutral beams formed from negative ions accelerated to 500 to 700 keV are needed for this device

  17. Neutral-beam current drive in tokamaks

    International Nuclear Information System (INIS)

    Devoto, R.S.

    1987-01-01

    The theory of neutral-beam current drive in tokamaks is reviewed. Experiments are discussed where neutral beams have been used to drive current directly and also indirectly through neoclassical effects. Application of the theory to an experimental test reactor is described. It is shown that neutral beams formed from negative ions accelerated to 500-700 keV are needed for this device

  18. On implicit abstract neutral nonlinear differential equations

    Energy Technology Data Exchange (ETDEWEB)

    Hernández, Eduardo, E-mail: lalohm@ffclrp.usp.br [Universidade de São Paulo, Departamento de Computação e Matemática, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto (Brazil); O’Regan, Donal, E-mail: donal.oregan@nuigalway.ie [National University of Ireland, School of Mathematics, Statistics and Applied Mathematics (Ireland)

    2016-04-15

    In this paper we continue our developments in Hernández and O’Regan (J Funct Anal 261:3457–3481, 2011) on the existence of solutions for abstract neutral differential equations. In particular we extend the results in Hernández and O’Regan (J Funct Anal 261:3457–3481, 2011) for the case of implicit nonlinear neutral equations and we focus on applications to partial “nonlinear” neutral differential equations. Some applications involving partial neutral differential equations are presented.

  19. Structural Basis for Differential Neutralization of Ebolaviruses

    Directory of Open Access Journals (Sweden)

    John M. Dye

    2012-04-01

    Full Text Available There are five antigenically distinct ebolaviruses that cause hemorrhagic fever in humans or non-human primates (Ebola virus, Sudan virus, Reston virus, Taï Forest virus, and Bundibugyo virus. The small handful of antibodies known to neutralize the ebolaviruses bind to the surface glycoprotein termed GP1,2. Curiously, some antibodies against them are known to neutralize in vitro but not protect in vivo, whereas other antibodies are known to protect animal models in vivo, but not neutralize in vitro. A detailed understanding of what constitutes a neutralizing and/or protective antibody response is critical for development of novel therapeutic strategies. Here, we show that paradoxically, a lower affinity antibody with restricted access to its epitope confers better neutralization than a higher affinity antibody against a similar epitope, suggesting that either subtle differences in epitope, or different characteristics of the GP1,2 molecules themselves, confer differential neutralization susceptibility. Here, we also report the crystal structure of trimeric, prefusion GP1,2 from the original 1976 Boniface variant of Sudan virus complexed with 16F6, the first antibody known to neutralize Sudan virus, and compare the structure to that of Sudan virus, variant Gulu. We discuss new structural details of the GP1-GP2 clamp, thermal motion of various regions in GP1,2 across the two viruses visualized, details of differential interaction of the crystallized neutralizing antibodies, and their relevance for virus neutralization.

  20. An experimental and theoretical study on the interaction of DNA and BSA with novel Ni2 +, Cu2 + and VO2 + complexes derived from vanillin bidentate Schiff base ligand

    Science.gov (United States)

    Dostani, Morteza; Kianfar, Ali Hossein; Mahmood, Wan Ahmad Kamil; Dinari, Mohammad; Farrokhpour, Hossein; Sabzalian, Mohammad R.; Abyar, Fatemeh; Azarian, Mohammad Hossein

    2017-06-01

    In this investigation, the structure of bidentate N,N-Schiff base ligand of vanillin, (E)-4-(((2-amino-5-nitrophenyl)imino)methyl)-2-methoxyphenol (HL) was determined by single crystal X-ray diffraction. The interaction of new [CuL2], [NiL2] and [VOL2] complexes with DNA and BSA was explored through UV-Vis and fluorescence spectroscopy. The electronic spectra changes displayed an isosbestic point for the complexes upon titration with DNA. The Kb values for the complexes [CuL2], [NiL2] and [VOL2] were 2.4 × 105, 1.9 × 105 and 4.2 × 104, respectively. [CuL2] complex was bound more toughly than [NiL2] and [VOL2] complexes. These complexes had a significant interaction with Bovine Serum Albumin (BSA) and the results demonstrated that the quenching mechanism was a static procedure. Also, the complexes interacted with BSA by more than one binding site (n > 1). Finally, the theoretical studies were performed using the docking method to calculate the binding constants and recognize the binding site of the DNA and BSA with the complexes. The ligand and complexes including Ni2 +, Cu2 + and VO2 + ions were colonized by fungal growth.

  1. Preparation and configurational analysis of the stereoisomers of β,γ-bidentate Rh(H2O)4ATP and α,β,γ-tridentate Rh(H2O)3ATP. A new class of enzyme active site probes

    International Nuclear Information System (INIS)

    Lu, Z.; Shorter, A.L.; Lin, I.; Dunaway-Mariano, D.

    1988-01-01

    Exchange-inert Co(III) and Cr(III) complexes of polyphosphates have proved to be useful probes of the structural and biochemical properties of naturally occurring Mg II (polyphosphate) complexes. However, applications of these complexes are not without limitations. The Cr III (polyphosphate) probes or their enzymatic products cannot be used in NMR methods because of the paramagnetic nature of the Cr(III) metal. The redox properties of the metal in the Co III (polyphosphate) complexes require that they also be coordinated to a nitrogen-containing ligand. This requirement is not always convenient. This work reported herein was undertaken to create a new class of exchange-inert metal polyphosphate complexes that contain a metal that is both diamagnetic and redox stable. The preparation, properties, and configurational analysis of the stereoisomers of β, γ-bidentate Rh(H 2 O) 4 ATP (ATP = adenosine 5'-triphosphate) and α,β,γ-tridentate Rh(H 2 O) 3 ATP are described. 12 refs., 5 figs

  2. Liberal Neutrality : Constructivist, not foundationalist

    Directory of Open Access Journals (Sweden)

    Lendell Horne

    2009-06-01

    Full Text Available In defending the principle of neutrality, liberals have often appealed to a more general moral principle that forbids coercing persons in the name of reasons those persons themselves cannot reasonably be expected to share. Yet liberals have struggled to articulate a non-arbitrary, non-dogmatic distinction between the reasons that persons can reasonably be expected to share and those they cannot. The reason for this, I argue, is that what it means to “share a reason” is itself obscure. In this paper I articulate two different conceptions of what it is to share a reason; I call these conceptions “foundationalist” and “constructivist.” On the foundationalist view, two people “share” a reason just in the sense that the same reason applies to each of them independently. On this view, I argue, debates about the reasons we share collapse into debates about the reasons we have, moving us no closer to an adequate defense of neutrality. On the constructivist view, by contrast, “sharing reasons” is understood as a kind of activity, and the reasons we must share are just those reasons that make this activity possible. I argue that the constructivist conception of sharing reasons yields a better defense of the principle of neutrality. À travers leur défense du principe de neutralité, les libéraux ont souvent interpellé un principe moral plus général qui interdit de contraindre des personnes pour des raisons dont on ne peut raisonnablement attendre que ces personnes elles-mêmes les partagent. Les libéraux éprouvent cependant de la difficulté à articuler une distinction non-arbitraire et non-dogmatique entre les raisons dont on peut raisonnablement attendre que les personnes les partagent et celles dont on ne le peut pas. Je soutiens dans cet article que cette difficulté provient du fait que «partager une raison » est une notion obscure. Pour illustrer cela, je me pencherai sur deux conceptions distinctes de ce que veut dire

  3. Determination of organophosphorus pesticides in water samples by using a new sensitive luminescent probe of Eu (III) complex

    Energy Technology Data Exchange (ETDEWEB)

    Azab, Hassan A., E-mail: azab2@yahoo.com; Anwar, Z.M.; Rizk, M.A.; Khairy, Gasser M.; El-Asfoury, M.H.

    2015-01-15

    This work describes the application of fluorescence for investigating the interactions of Eu(III)-TAN-1,10 phenanthroline (where TAN=4,4,4-Trifluoro-1-(2-naphthyl)-1,3-butanedione) with pesticides Chlorpyrifos, Malathion, Endosulfan, Heptachlor. The complex was synthesized and characterized by elemental analysis, FTIR, x-ray spectroscopy, solid fluorescence and thermal analysis. The results indicated that the composition of this complex is [Eu(TAN){sub 2}(Phen)(H{sub 2}O){sub 2}]Cl. The luminescence properties of the complex in different solvents and at different pH values have been investigated. The results show that the complex exhibits more efficient luminescence at pH=7.5. The interactions of Eu-complex with different pesticides (Chlorpyrifos, Malathion, Endosulfan, and Heptachlor) in aqueous medium have been investigated by fluorescence measurements. The luminescence intensity of the probe is quenched by Malathion and enhanced by (Endosulfan, Heptachlor, and Chlorpyrifos). Direct methods for the determination of the pesticides under investigation have been developed using the luminescence variations of the probe in solution. The detection limits are 0.47, 1.02, 0.66, 0.64 µmol/L for Chlorpyrifos, Endosulfan, Heptachlor, and Malathion, respectively. The binding constants and thermodynamic parameters of the pesticides with probe were evaluated. The emission quantum yield (QY=0.71) of Eu(III)-complex was determined using tris (2,2'-bipyridyl) dichlororuthenium(II) hexahydrate. A thermodynamic analysis showed that the reaction is spontaneous with negative ΔG. Effect of some relevant interferents on the detection of pesticides has been investigated. The new method was applied to the determination of the pesticides in different types of water samples (tap, river, and waste water). - Highlights: • A new luminescent probe of Eu (III) complex has been developed for sensing some organophosphorus pesticides. • Four guest pesticides Chlorpyrifos, Malathion

  4. Determination of organophosphorus pesticides in water samples by using a new sensitive luminescent probe of Eu (III) complex

    International Nuclear Information System (INIS)

    Azab, Hassan A.; Anwar, Z.M.; Rizk, M.A.; Khairy, Gasser M.; El-Asfoury, M.H.

    2015-01-01

    This work describes the application of fluorescence for investigating the interactions of Eu(III)-TAN-1,10 phenanthroline (where TAN=4,4,4-Trifluoro-1-(2-naphthyl)-1,3-butanedione) with pesticides Chlorpyrifos, Malathion, Endosulfan, Heptachlor. The complex was synthesized and characterized by elemental analysis, FTIR, x-ray spectroscopy, solid fluorescence and thermal analysis. The results indicated that the composition of this complex is [Eu(TAN) 2 (Phen)(H 2 O) 2 ]Cl. The luminescence properties of the complex in different solvents and at different pH values have been investigated. The results show that the complex exhibits more efficient luminescence at pH=7.5. The interactions of Eu-complex with different pesticides (Chlorpyrifos, Malathion, Endosulfan, and Heptachlor) in aqueous medium have been investigated by fluorescence measurements. The luminescence intensity of the probe is quenched by Malathion and enhanced by (Endosulfan, Heptachlor, and Chlorpyrifos). Direct methods for the determination of the pesticides under investigation have been developed using the luminescence variations of the probe in solution. The detection limits are 0.47, 1.02, 0.66, 0.64 µmol/L for Chlorpyrifos, Endosulfan, Heptachlor, and Malathion, respectively. The binding constants and thermodynamic parameters of the pesticides with probe were evaluated. The emission quantum yield (QY=0.71) of Eu(III)-complex was determined using tris (2,2'-bipyridyl) dichlororuthenium(II) hexahydrate. A thermodynamic analysis showed that the reaction is spontaneous with negative ΔG. Effect of some relevant interferents on the detection of pesticides has been investigated. The new method was applied to the determination of the pesticides in different types of water samples (tap, river, and waste water). - Highlights: • A new luminescent probe of Eu (III) complex has been developed for sensing some organophosphorus pesticides. • Four guest pesticides Chlorpyrifos, Malathion, Endosulfan, and

  5. Effect of Intensive Atropine Doses (Rapid Incremental Loading and Titration for Management of Organophosphorus Pesticide Poisoning: a Case Series

    Directory of Open Access Journals (Sweden)

    Abu Saleh Ahmed

    2014-03-01

    Full Text Available Background:Acute poisoning with organophosphorus (OP pesticides is a common method of suicide and entails considerable mortality in Bangladesh. The objective of this study was to evaluate the effects and outcomes of a protocol for treatment of OP poisoning that included titrated incremental atropine as loading dose and slow infusion for maintenance.  Methods:In this prospective descriptive case series, definitive OP poisoned patients were enrolled in an adult medicine unit of Dhaka Medical College Hospital from April 2006 to April 2007. Clinical examinations were done as soon as the patient entered the ward. Patient’s demographics, comorbid conditions and the occurrence of specific clinical outcomes including death, need for assisted ventilation and clinical complications were recorded. The patients were treated according to the protocol. Results: A total of 56 patients were enrolled over the study period. The median age of the study population was 22.5 years. Most patients were men (67.8%. The most common clinical presentation was miosis (58.9%. In total, 11 patients died (19.6%. Intermediate syndrome developed in 12 patients (21.4% and 6 of them died. Assisted ventilation was required in 16 cases (28.5. Patients with diastolic blood pressure ≤ 70 mmHg and/or GCS ≤ 10 were significantly less likely to survive (P = 0.02, 0.006, respectively. Moreover, early respiratory failure (P < 0.001 and the need for assisted ventilation (P < 0.001 were significantly higher among deceased cases. The mortality rate in this study was similar to previous studies. The frequency of atropine toxicity in the present study (1.8% was considerably lower than conventional regimen used in previous studies. Conclusion:Using the new protocol, lower rate of atropine toxicity developed in victims. Hence, the new protocol appears to be safer and its effectiveness should be further evaluated in case control studies in Bangladesh.    How to cite this article: Ahmed AS

  6. Poisoning of raptors with organophosphorus and carbamate pesticides with emphasis on Canada, U.S. and U.K.

    Science.gov (United States)

    Mineau, P.; Fletcher, M.R.; Glaser, L.C.; Thomas, N.J.; Brassard, C.; Wilson, L.K.; Elliott, J.E.; Lyon, L.A.; Henny, C.J.; Bollinger, T.; Porter, S.L.

    1999-01-01

    We reviewed cases of raptor mortality resulting from cholinesterase-inhibiting pesticides. We compiled records from the U.S., U.K. and Canada for the period 1985-95 (520 incidents) and surveyed the relevant literature to identify the main routes of exposure and those products that led to the greatest number of poisoning cases. A high proportion of cases in the U.K. resulted from abusive uses of pesticides (willful poisoning). The proportion was smaller in North America where problems with labeled uses of pesticides were as frequent as abuse cases. Poisoning resulting from labeled use was possible with a large number of granular pesticides and some seed treatments through secondary poisoning or through the ingestion of contaminated invertebrates, notably earthworms. With the more toxic products, residue levels in freshly-sprayed insects were high enough to cause mortality. The use of organophosphorus products as avicides and for the topical treatment of livestock appeared to be common routes of intoxication. The use of insecticides in dormant oils also gave rise to exposure that can be lethal or which can debilitate birds and increase their vulnerability. A few pesticides of high toxicity were responsible for the bulk of poisoning cases. Based on limited information, raptors appeared to be more sensitive than other bird species to organophosphorus and carbamate pesticides. Some of the more significant risk factors that resulted in raptor poisonings were: insectivory and vermivory; opportunistic taking of debilitated prey; scavenging, especially if the gastrointestinal tracts are consumed; presence in agricultural areas; perceived status as pest species; and flocking or other gregarious behavior at some part of their life cycle. Lethal or sublethal poisoning should always be considered in the diagnosis of dead or debilitated raptors even when another diagnosis (e.g., electrocution, car or building strike) is apparent. Many cases of poisoning are not currently

  7. Luminescence recognition of different organophosphorus pesticides by the luminescent Eu(III)–pyridine-2,6-dicarboxylic acid probe

    International Nuclear Information System (INIS)

    Azab, Hassan A.; Duerkop, Axel; Anwar, Z.M.; Hussein, Belal H.M.; Rizk, Moustafa A.; Amin, Tarek

    2013-01-01

    Highlights: ► Europium (III) luminescence quenching has been used for sensing organophosphorous pesticides. ► Four guest pesticides chlorfenvinphos, malathion, azinphos, and paraxon ethyl were used. ► A sensitive rapid, cheap direct method for the determination of the pesticides has been developed. ► The method was applied to the determination of the OPs in tap, river, mineral, and waste waters. - Abstract: Luminescence quenching of a novel long lived Eu(III)–pyridine-2,6-dicarboxylic acid probe of 1:2 stoichiometric ratio has been studied in 0.10 volume fraction ethanol–water mixture at pH 7.5 (HEPES buffer) in the presence of the organophosphorus pesticides chlorfenvinphos (P1), malathion (P2), azinphos (P3), and paraxon ethyl (P4). The luminescence intensity of Eu(III)–(PDCA) 2 probe decreases as the concentration of the pesticide increases. It was observed that the quenching due to P3 and P4 proceeds via both diffusional and static quenching processes. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence quenching of Eu(III)–pyridine-2,6-dicarboxylic acid probe in solution. The linear range for determination of the selected pesticides is 1.0–35.0 μM. The detection limits were 0.24–0.55 μM for P3, P4, and P1 and 2.5 μM for P2, respectively. The binding constants (K), and thermodynamic parameters of the OPs with Eu(III)–(PDCA) 2 were evaluated. Positive and negative values of entropy (ΔS) and enthalpy (ΔH) changes for Eu(III)–(PDCA) 2 –P1 ternary complex were calculated. As the waters in this study do not contain the above mentioned OPs over the limit detectable by the method, a recovery study was carried out after the addition of the adequate amounts of the organophosphorus pesticides under investigation.

  8. Luminescence recognition of different organophosphorus pesticides by the luminescent Eu(III)-pyridine-2,6-dicarboxylic acid probe

    Energy Technology Data Exchange (ETDEWEB)

    Azab, Hassan A., E-mail: azab2@yahoo.com [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt); Duerkop, Axel [Institute of Analytical Chemistry, Chemo and Biosensors, Regensburg University, D-93040 Regensburg (Germany); Anwar, Z.M.; Hussein, Belal H.M.; Rizk, Moustafa A.; Amin, Tarek [Chemistry Department, Faculty of Science, Suez Canal University, Ismailia 41522 (Egypt)

    2013-01-08

    Highlights: Black-Right-Pointing-Pointer Europium (III) luminescence quenching has been used for sensing organophosphorous pesticides. Black-Right-Pointing-Pointer Four guest pesticides chlorfenvinphos, malathion, azinphos, and paraxon ethyl were used. Black-Right-Pointing-Pointer A sensitive rapid, cheap direct method for the determination of the pesticides has been developed. Black-Right-Pointing-Pointer The method was applied to the determination of the OPs in tap, river, mineral, and waste waters. - Abstract: Luminescence quenching of a novel long lived Eu(III)-pyridine-2,6-dicarboxylic acid probe of 1:2 stoichiometric ratio has been studied in 0.10 volume fraction ethanol-water mixture at pH 7.5 (HEPES buffer) in the presence of the organophosphorus pesticides chlorfenvinphos (P1), malathion (P2), azinphos (P3), and paraxon ethyl (P4). The luminescence intensity of Eu(III)-(PDCA){sub 2} probe decreases as the concentration of the pesticide increases. It was observed that the quenching due to P3 and P4 proceeds via both diffusional and static quenching processes. Direct methods for the determination of the pesticides under investigation have been developed using the luminescence quenching of Eu(III)-pyridine-2,6-dicarboxylic acid probe in solution. The linear range for determination of the selected pesticides is 1.0-35.0 {mu}M. The detection limits were 0.24-0.55 {mu}M for P3, P4, and P1 and 2.5 {mu}M for P2, respectively. The binding constants (K), and thermodynamic parameters of the OPs with Eu(III)-(PDCA){sub 2} were evaluated. Positive and negative values of entropy ({Delta}S) and enthalpy ({Delta}H) changes for Eu(III)-(PDCA){sub 2}-P1 ternary complex were calculated. As the waters in this study do not contain the above mentioned OPs over the limit detectable by the method, a recovery study was carried out after the addition of the adequate amounts of the organophosphorus pesticides under investigation.

  9. Simultaneous detection of dual biomarkers from humans exposed to organophosphorus pesticides by combination of immunochromatographic test strip and ellman assay.

    Science.gov (United States)

    Yang, Mingming; Zhao, Yuting; Wang, Limin; Paulsen, Michael; Simpson, Christopher D; Liu, Fengquan; Du, Dan; Lin, Yuehe

    2018-05-01

    A novel sandwich immunoassay based immunochromatographic test strip (ICTS) has been developed for simultaneously measuring both butyrylcholinesterase (BChE) activity and the total amount of BChE (including inhibited and active enzyme) from 70 μLpost-exposure human plasma sample. The principle of this method is based on the BChE monoclonal antibody (MAb) capable of acting as both capture antibody and detection antibody. The BChE MAb which was immobilized on the test line was able to recognize both organophosphorus BChE adducts (OP-BChE) and BChE and provided equal binding affinity, permitting detection of the total enzyme amount in post-exposure human plasma samples. The formed immunocomplexes on the test line can further be excised from the test-strip for subsequent off-line measurement of BChE activity using the Ellman assay. Therefore, dual biomarkers of BChE activity and phosphorylation (OP-BChE) will be obtained simultaneously. The whole sandwich-immunoassay was performed on one ICTS, greatly reducing analytical time. The ICTS sensor showed excellent linear responses for assaying total amount of BChE and active BChE ranging from 0.22 to 3.58nM and 0.22-7.17nM, respectively. Both the signal detection limits are 0.10nM. We validated the practical application of the proposed method to measure 124 human plasma samples from orchard workers and cotton farmers with long-term exposure to organophosphorus pesticides (OPs). The results were in highly agreement with LC/MS/MS which verified our method is extremely accurate. Combining the portability and rapidity of test strip and the compatibility of BChE MAb as both capture antibody and detection antibody, the developed method provides a baseline-free, low-cost and rapid tool for in-field monitoring of OP exposures. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. The status of neutral currents

    International Nuclear Information System (INIS)

    Zwirner, F.

    1987-11-01

    The situation of particle physics today is quite puzzling. On the one hand, the Standard Model (SM) of strong and electroweak interactions is consistent with all confirmed experimental data but theoretically rather unsatisfactory. On the other hand, none of the many theoretical speculations which try to go beyond the SM has (yet) received the slightest experimental support. The solution to this dilemma can only come from new data: either from the detection of a new particle threshold at high energy colliders, or from the appearance of some small discrepancy in high-precision experiments. A crucial sector for testing the SM and its extensions is that of neutral currents (NC), where an impressive amount of data has been collected in recent years. While waiting for the next generation of experiments, it is certainly useful to take stock of our knowledge, determining the NC parameters as precisely as we can and putting limits on possible deviations from the SM. The present talk contains the results of a recent analysis along these lines: the first part illustrates how a set of 'model-independent' parameters can be extracted from the available NC data, the second part particularizes the analysis to the SM and to some superstring-inspired models with an additional Z' in their low-energy spectrum. 27 refs., 3 figs., 1 tab

  11. Auditors' Professional Skepticism: Neutrality versus Presumptive Doubt

    NARCIS (Netherlands)

    Groot, T.L.C.M.; Quadackers, L.M.; Wright, A.

    2014-01-01

    Although skepticism is widely viewed as essential to audit quality, there is a debate about what form is optimal. The two prevailing perspectives that have surfaced are "neutrality" and "presumptive doubt." With neutrality, auditors neither believe nor disbelieve client management. With presumptive

  12. 32 CFR 644.323 - Neutral language.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Neutral language. 644.323 Section 644.323 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal § 644.323 Neutral language. Wherever the words “man”, “men”, or their related...

  13. 3He neutral current detectors at SNO

    International Nuclear Information System (INIS)

    Elliott, S.R.; Browne, M.C.; Doe, P.J.

    1998-01-01

    The flux of solar neutrinos measured via charged and neutral current interactions can provide a model independent test of neutrino oscillations. Since the Sudbury Neutrino Observatory uses heavy water as a target, it has a large sensitivity to both interactions. A technique for observing the neutral current breakup of the deuteron using 3 He proportional counters is described

  14. Photoproduction of neutral pions off protons

    NARCIS (Netherlands)

    Crede, V.; Sparks, N.; Wilson, A.; Anisovich, A. V.; Bacelar, J. C. S.; Bantes, R.; Bartholomy, O.; Bayadilov, D.; Beck, R.; Beloglazov, Y. A.; Castelijns, R.; Dutz, H.; Elsner, D.; Ewald, R.; Frommberger, F.; Funke, Chr; Gregor, R.; Gridnev, A.; Gutz, E.; Hillert, W.; Hoffmeister, P.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Kammer, S.; Klein, Frank; Klein, Friedrich; Klempt, E.; Kotulla, M.; Krusche, B.; Löhner, H.; Lopatin, I. V.; Lugert, S.; Menze, D.; Mertens, T.; Messchendorp, J. G.; Metag, V.; Nanova, M.; Nikonov, V. A.; Novinski, D.; Novotny, R.; Ostrick, M.; Pant, L. M.; van Pee, H.; Pfeiffer, M.; Roy, A.; Sarantsev, A. V.; Schadmand, S.; Schmidt, C.; Schmieden, H.; Schoch, B.; Shende, S.; Sokhoyan, V.; Suele, A.; Sumachev, V. V.; Szczepanek, T.; Thoma, U.; Trnka, D.; Varma, R.; Walther, D.; Wendel, Ch

    2011-01-01

    Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector in the reaction gamma p -> p pi(0) for photon energies between 0.85 and 2.50 GeV. The pi(0) mesons are observed in their dominant neutral decay mode: pi(0) -> gamma gamma. For the first time, the differential cross

  15. On the possible eigenoscillations of neutral sheets

    International Nuclear Information System (INIS)

    Almeida, W.A.; Costa, J.M. da; Aruquipa, E.G.; Sudano, J.P.

    1974-12-01

    A neutral sheet model with hyperbolic tangent equilibrium magnetic field and hyperbolic square secant density profiles is considered. It is shown that the equation for small oscillations takes the form of an eigenvalue oscillation problem. Computed eigenfrequencies of the geomagnetic neutral sheet were found to be in the range of the resonant frequencies of the geomagnetic plasma sheet computed by other authors

  16. Gender Neutrality: Women's Friend or Foe?

    Science.gov (United States)

    Steuernagel, Trudy

    Gender neutral public policies are those that are either silent on the question of the existence of significant gender differences or incorporate a perspective which mandates that such differences be ignored. Prominent voices today contend that gender neutrality favors males and have held the male standard as the one for which women should aspire.…

  17. Targets for high power neutral beams

    International Nuclear Information System (INIS)

    Kim, J.

    1980-01-01

    Stopping high-power, long-pulse beams is fast becoming an engineering challenge, particularly in neutral beam injectors for heating magnetically confined plasmas. A brief review of neutral beam target technology is presented along with heat transfer calculations for some selected target designs

  18. On plasma-neutral gas interaction

    International Nuclear Information System (INIS)

    Venkataramani, N.; Mattoo, S.K.

    1980-01-01

    The importance of plasma-neutral gas interaction layer has been emphasized by pointing out its application to a wide variety of physical phenomena. The interaction of a magnetised plasma stream penetrating a neutral gas cloud is discussed in the light of Alfven's critical velocity and Varma's threshold velocity on the ionising interaction. Interaction of a moving magnetised plasma with a stationary neutral gas has been studied and described. The device comprises of a plasma gun and an interaction region where neutral gas cloud is injected. The interaction region is provided with a transverse magnetic field of upto 1000 G. Several diagnostics deployed at the interaction region to make measurements on the macroscopic parameters of plasma and neutral gas are described. The parameters of discharge circuits are measured with high current and voltage probes. An interaction between a magnetised plasma stream and a neutral gas cloud is demonstrated. It is shown that this interaction does not have Varma's threshold on their relative velocity. The Alfven's critical velocity phenomenon is shown to depend on the integrated column neutral gas density that a plasma stream encounters while penetrating through it and not on the neutral gas density in the range of 10 17 -10 21 m -3 . (auth.)

  19. Net Neutrality and Inflation of Traffic

    NARCIS (Netherlands)

    Peitz, M.; Schütt, F.

    2015-01-01

    Under strict net neutrality Internet service providers (ISPs) are required to carry data without any differentiation and at no cost to the content provider. We provide a simple framework with a monopoly ISP to evaluate different net neutrality rules. Content differs in its sensitivity to delay.

  20. Net neutrality and inflation of traffic

    NARCIS (Netherlands)

    Peitz, M.; Schütt, Florian

    Under strict net neutrality Internet service providers (ISPs) are required to carry data without any differentiation and at no cost to the content provider. We provide a simple framework with a monopoly ISP to evaluate the short-run effects of different net neutrality rules. Content differs in its

  1. Neutralization of wastewater from nitrite passivation

    International Nuclear Information System (INIS)

    Pawlowski, L.; Mientki, B.; Wasag, H.

    1982-01-01

    A method for neutralization of wastewater formed in nitrite passivation has been presented. The method consists of introducing urea into wastewater and acidifying it with sulphuric acid. Wastewater is neutralized with lime. After clarification, wastewater can be drained outside the plant

  2. A neutral sampling formula for multiple samples and an `exact' test of neutrality

    NARCIS (Netherlands)

    Etienne, R.S.

    2007-01-01

    As the utility of the neutral theory of biodiversity is increasingly being recognized, there is also an increasing need for proper tools to evaluate the relative importance of neutral processes (dispersal limitation and stochasticity). One of the key features of neutral theory is its close link to

  3. A neutral sampling formula for multiple samples and an 'exact' test of neutrality

    NARCIS (Netherlands)

    Etienne, Rampal S.

    As the utility of the neutral theory of biodiversity is increasingly being recognized, there is also an increasing need for proper tools to evaluate the relative importance of neutral processes (dispersal limitation and stochasticity). One of the key features of neutral theory is its close link to

  4. Cobalt(II Complexes with N,N,N-Scorpionates and Bidentate Ligands: Comparison of Hydrotris(3,5-dimethylpyrazol-1-ylborate Tp* vs. Phenyltris(4,4-dimethyloxazolin-2-ylborate ToM to Control the Structural Properties and Reactivities of Cobalt Centers

    Directory of Open Access Journals (Sweden)

    Toshiki Nishiura

    2018-06-01

    Full Text Available Scorpionate ligands Tp* (hydrotris(3,5-dimethylpyrazol-1-ylborate and ToM (tris(4,4-dimethyloxazolin-2-ylphenylborate complexes of cobalt(II with bidentate ligands were synthesized. Both Tp* and ToM coordinate to cobalt(II in a tridentate fashion when the bidentate ligand is the less hindered acetylacetonate. In crystal structures, the geometry of cobalt(II supported by the N3O2 donor set in the Tp* complex is a square-pyramid, whereas that in the ToM complex is close to a trigonal-bipyramid. Both Tp*- and ToM-acac complexes exhibit solvatochromic behavior, although the changing structural equilibria of these complexes in MeCN are quite different. In the bis(1-methylimidazol-2-ylmethylphenylborate (LPh complexes, Tp* retains the tridentate (к3 mode, whereas ToM functions as the bidentate (к2 ligand, giving the tetrahedral cobalt(II complex. The bowl-shaped cavity derived from the six methyl groups on ToM lead to susceptibility to the bulkiness of the opposite bidentate ligand. The entitled scorpionate compounds mediate hydrocarbon oxidation with organic peroxides. Allylic oxidation of cyclohexene occurs mainly on the reaction with tert-butyl hydroperoxide (TBHP, although the catalytic efficiency of the scorpionate ligand complexes is lower than that of Co(OAc2 and Co(acac2. On cyclohexane oxidation with meta-chloroperbenzoic acid (mCPBA, both ToM and Tp* complexes function as catalysts for hydroxylation. The higher electron-donating ToM complexes show faster initial reaction rates compared to the corresponding Tp* complexes.

  5. Neutral beam in ALVAND IIC tokamak

    International Nuclear Information System (INIS)

    Ghrannevisse, M.; Moradshahi, M.; Avakian, M.

    1992-01-01

    Neutral beams have a wide application in tokamak experiments. It used to heat; fuel; adjust electric potentials in plasmas and diagnose particles densities and momentum distributions. It may be used to sustain currents in tokamaks to extend the pulse length. A 5 KV; 500 mA ion source has been constructed by plasma physics group, AEOI and it used to produce plasma and study the plasma parameters. Recently this ion source has been neutralized and it adapted to a neutral beam source; and it used to heat a cylindrical DC plasma and the plasma of ALVAND IIC Tokamak which is a small research tokamak with a minor radius of 12.6 cm, and a major radius of 45.5 cm. In this paper we report the neutralization of the ion beam and the results obtained by injection of this neutral beam into plasmas. (author) 2 refs., 4 figs

  6. Tax Neutrality on International Capital Investments

    Directory of Open Access Journals (Sweden)

    Gizem KAPUCU

    2017-07-01

    Full Text Available The tax policies which states follow with regard to developing technology and capital investments with raising mobility due to globalism are need to be discussed in its legal basis. The principle of tax neutrality has the aim of being legal foundation for these policies. According to this, the neutrality principle in taxation of international capital investments is provided with two measures, namely; not effecting the investment decision and not discriminate between investments. In this paper, initially focused on the conceptual framework and the foundations of the tax neutrality principle and later capital export neutrality and capital import neutrality are considered and explained with regard to international capital movements. Moreover, conformity and diversion to the principle of the current situation and regulations in OECD, EU and Turkey are examined.

  7. Sputtering of neutral and ionic indium clusters

    International Nuclear Information System (INIS)

    Ma, Z.; Coon, S.R.; Calaway, W.F.; Pellin, M.J.; Gruen, D.M.; Von Nagy-Felsobuki, E.I.

    1993-01-01

    Secondary neutral and secondary ion cluster yields were measured during the sputtering of a polycrystalline indium surface by normally incident ∼4 keV Ar + ions. In the secondary neutral mass spectra, indium clusters as large as In 32 were observed. In the secondary ion mass spectra, indium clusters up to In 18 + were recorded. Cluster yields obtained from both the neutral and ion channel exhibited a power law dependence on the number of constituent atoms, n, in the cluster, with the exponents measured to be -5.6 and -4. 1, respectively. An abundance drop was observed at n=8, 15, and 16 in both the neutral and ion yield distributions suggesting that the stability of the ion (either secondary ion or photoion) plays a significant role in the observed distributions. In addition, our experiments suggest that unimolecular decomposition of the neutral cluster may also plays an important role in the measured yield distributions

  8. Neutral-beam-heating applications and development

    International Nuclear Information System (INIS)

    Menon, M.M.

    1981-01-01

    The technique of heating the plasma in magnetically confined fusion devices by the injection of intense beams of neutral atoms is described. The basic principles governing the physics of neutral beam heating and considerations involved in determining the injection energy, power, and pulse length required for a fusion reactor are discussed. The pertinent experimental results from various fusion devices are surveyed to illustrate the efficacy of this technique. The second part of the paper is devoted to the technology of producing the neutral beams. A state-of-the-art account o the development of neutral injectors is presented, and the prospects for utilizing neutral injection to heat the plasma in a fusion reactor are examined

  9. ORNL neutral-beam program in 1978

    International Nuclear Information System (INIS)

    Whealton, J.H.

    1982-12-01

    This report was presented at the ion source workshop held at Culham Laboratory, Abingdon, Oxfordshire, in 1978. Because the proceedings of that conference are unavailable, and because the material in this report is still not to be found elsewhere, it is issued as a laboratory report. The neutral beam group at Oak Ridge National Laboratory has constructed neutral beam generators for the ORMAK and PLT devices, is presently constructing neutral beam devices for the ISX and PDX devices, and is contemplating the construction of neutral beam systems for the advanced TNS device. These neutral beam devices stem from the pioneering work on ion sources of G.G. Kelley and O.B. Morgan. We describe the ion sources under development at this laboratory, the beam optics exhibited by these sources, as well as some theoretical considerations, and finally the remainder of the beamline design

  10. Optical Detection of Paraoxon Using Single-Walled Carbon Nanotube Films with Attached Organophosphorus Hydrolase-Expressed Escherichia coli

    Directory of Open Access Journals (Sweden)

    Intae Kim

    2015-05-01

    Full Text Available In whole-cell based biosensors, spectrophotometry is one of the most commonly used methods for detecting organophosphates due to its simplicity and reliability. The sensor performance is directly affected by the cell immobilization method because it determines the amount of cells, the mass transfer rate, and the stability. In this study, we demonstrated that our previously-reported microbe immobilization method, a microbe-attached single-walled carbon nanotube film, can be applied to whole-cell-based organophosphate sensors. This method has many advantages over other whole-cell organophosphate sensors, including high specific activity, quick cell immobilization, and excellent stability. A device with circular electrodes was fabricated for an enlarged cell-immobilization area. Escherichia coli expressing organophosphorus hydrolase in the periplasmic space and single-walled carbon nanotubes were attached to the device by our method. Paraoxon was hydrolyzed using this device, and detected by measuring the concentration of the enzymatic reaction product, p-nitrophenol. The specific activity of our device was calculated, and was shown to be over 2.5 times that reported previously for other whole-cell organophosphate sensors. Thus, this method for generation of whole-cell-based OP biosensors might be optimal, as it overcomes many of the caveats that prevent the widespread use of other such devices.

  11. Heat Release Property and Fire Performance of the Nomex/Cotton Blend Fabric Treated with a Nonformaldehyde Organophosphorus System

    Directory of Open Access Journals (Sweden)

    Charles Q. Yang

    2016-09-01

    Full Text Available Blending Nomex® with cotton improves its affordability and serviceability. Because cotton is a highly flammable fiber, Nomex®/cotton blend fabrics containing more than 20% cotton require flame-retardant treatment. In this research, combination of a hydroxyl functional organophosphorus oligmer (HFPO and 1,2,3,4-butanetetracarboxylic acid (BTCA was used for flame retardant finishing of the 65/35 Nomex®/cotton blend woven fabric. The system contains HFPO as a flame retardant, BTCA as a bonding agent, and triethenolamine (TEA as a reactive additive used to enhance the performance of HFPO/BTCA. Addition of TEA improves the hydrolysis resistance of the HFPO/BTCA crosslinked polymeric network on the blend fabric. Additionally, TEA enhances HFPO’s flame retardant performance by reducing formation of calcium salts and also by providing synergistic nitrogen to the treated blend fabric. The Nomex®/cotton blend fabric treated with the HFPO/BTCA/TEA system shows high flame resistance and high laundering durability at a relatively low HFPO concentration of 8% (w/w. The heat release properties of the treated Nomex®/cotton blend fabric were measured using microscale combustion calorimetry. The functions of BTCA; HFPO and TEA on the Nomex®/cotton blend fabric were elucidated based on the heat release properties, char formation, and fire performance of the treated blend fabric.

  12. Cytoplasmic vacuolation in cultured rat astrocytes induced by an organophosphorus agent requires extracellular signal-regulated kinase activation

    International Nuclear Information System (INIS)

    Isobe, Ichiro; Maeno, Yoshitaka; Nagao, Masataka; Iwasa, Mineo; Koyama, Hiroyoshi; Seko-Nakamura, Yoshimi; Monma-Ohtaki, Jun

    2003-01-01

    There are various toxic chemicals that cause cell death. However, in certain cases deleterious agents elicit various cellular responses prior to cell death. To determine the cellular mechanisms by which such cellular responses are induced is important, but sufficient attention has not been paid to this issue to date. In this study, we showed the characteristic effects of an organophosphorus (OP) agent, bis(pinacolyl methyl)phosphonate (BPMP), which we synthesized for the study of OP nerve agents, on cultured rat astrocytes. Morphologically, BPMP induced cytoplasmic vacuolation and stellation in the rat astrocytes. Cytoplasmic vacuolation is a cell pathological change observed, for example, in vacuolar degeneration, and stellation has been reported in astrocytic reactions against various stimuli. By pretreatment with cycloheximide, a protein synthesis inhibitor, stellation was inhibited, although vacuolation was not. Cell staining with a mitochondrion-selective dye indicated that the vacuolation probably occurs in the mitochondria that are swollen and vacuolatred in the center. Interestingly, the extracellular signal-regulated kinase (ERK) cascade inhibitor inhibited vacuolation and, to some extent, stellation. These results suggest that the ERK signaling cascade is important for the induction of mitochondrial vacuolation. We expect that a detailed study of these astrocytic reactions will provide us new perspectives regarding the variation and pathological significance of cell morphological changes, such as vacuolar degeneration, and also the mechanisms underlying various neurological disorders

  13. Determination of Carbamate and Organophosphorus Pesticides in Vegetable Samples and the Efficiency of Gamma-Radiation in Their Removal

    Directory of Open Access Journals (Sweden)

    Muhammed Alamgir Zaman Chowdhury

    2014-01-01

    Full Text Available In the present study, the residual pesticide levels were determined in eggplants (Solanum melongena (n=16, purchased from four different markets in Dhaka, Bangladesh. The carbamate and organophosphorus pesticide residual levels were determined by high performance liquid chromatography (HPLC, and the efficiency of gamma radiation on pesticide removal in three different types of vegetables was also studied. Many (50% of the samples contained pesticides, and three samples had residual levels above the maximum residue levels determined by the World Health Organisation. Three carbamates (carbaryl, carbofuran, and pirimicarb and six organophosphates (phenthoate, diazinon, parathion, dimethoate, phosphamidon, and pirimiphos-methyl were detected in eggplant samples; the highest carbofuran level detected was 1.86 mg/kg, while phenthoate was detected at 0.311 mg/kg. Gamma radiation decreased pesticide levels proportionately with increasing radiation doses. Diazinon, chlorpyrifos, and phosphamidon were reduced by 40–48%, 35–43%, and 30–45%, respectively, when a radiation strength of 0.5 kGy was utilized. However, when the radiation dose was increased to 1.0 kGy, the levels of the pesticides were reduced to 85–90%, 80–91%, and 90–95%, respectively. In summary, our study revealed that pesticide residues are present at high amounts in vegetable samples and that gamma radiation at 1.0 kGy can remove 80–95% of some pesticides.

  14. A novel fluorimetric sensing platform for highly sensitive detection of organophosphorus pesticides by using egg white-encapsulated gold nanoclusters.

    Science.gov (United States)

    Yan, Xu; Li, Hongxia; Hu, Tianyu; Su, Xingguang

    2017-05-15

    Assays for organophosphorus pesticides (OPs) with high sensitivity as well as on-site screening have been urgently required to protect ecosystem and prevent disease. Herein, a novel fluorimetric sensing platform was constructed for quantitative detection of OPs via tyrosinase (TYR) enzyme-controlled quenching of gold nanoclusters (AuNCs). One-step green synthetic approach was developed for the synthesis of AuNCs by using chicken egg white (CEW) as template and stabilizer. Initially, TYR can catalyze the oxidation of dopamine to dopaminechrome, which can efficiently quench the fluorescence intensity of AuNCs at 630nm based on dynamic quenching process. However, with the presence of OPs, the activity of TYR was inhibited, resulting in the fluorescence recovery of AuNCs. This proposed fluorescence platform was demonstrated to enable rapid detection for OPs (paraoxon as model) and to provide excellent sensitivity with a detection limit of 0.1ngmL -1 . Significantly, the fluorescence probe was used to prepare paper-based test strips for visual detection of OPs, which validated the excellent potential for real-time and on-site application. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Optical detection of organophosphorus compounds based on Mn-doped ZnSe d-dot enzymatic catalytic sensor.

    Science.gov (United States)

    Gao, Xue; Tang, Guangchao; Su, Xingguang

    2012-01-01

    In this paper, we report a sensitive and selective method for detection of organophosphorus compounds (OPs) based on Mn:ZnSe d-dots-enzyme-hydrogen peroxide (H(2)O(2)) fluorescence quenching system. Acetylcholine esterase (AChE) can hydrolyze acetylcholine (ACh) to choline. Subsequently, choline oxidase (ChOx) oxidizes choline to generate H(2)O(2). The enzyme-generated H(2)O(2) can quench the fluorescence of Mn:ZnSe d-dots. When paraoxon are introduced in solution, it can interact with the active centers of AChE and decrease the enzyme activity. This leads to the decrease of the H(2)O(2) production and then the fluorescence quenching rate of Mn:ZnSe d-dots. Experimental results showed that the enzyme inhibition percentage of Mn:ZnSe d-dots-ChOx-AChE-ACh system was proportional to the logarithm of paraoxon in the range 4.84×10(-11) to 4.84×10(-6) mol/L with the detection limit (S/N=3) of 1.31×10(-11) mol/L. The proposed biosensor has been employed for quick determination of paraoxon in tap water and milk samples with satisfactory reproducibility and accuracy. This nano-biosensor was proved to be sensitive, rapid, simple and tolerance of most interfering substances. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Detection of residual organochlorine and organophosphorus pesticides in agricultural soil in Rio Verde region of San Luis Potosi, Mexico.

    Science.gov (United States)

    Velasco, Antonio; Hernández, Sergio; Ramírez, Martha; Ortíz, Irmene

    2014-01-01

    Organochlorine pesticides were intensively used in Mexico from 1950 until their ban and restriction in 1991. However, the presence of these compounds is commonly reported in many regions of the country. The aim of the present study was to identify and quantify residual organochlorine and organophosphorus pesticides in agricultural soil in Rio Verde region, San Luis Potosi state, which has been identified as possibly polluted by pesticides. Composed samples from 24 zones covering an area of approximately 5,440 ha were analyzed. The most frequently found pesticides were p,p'-DDT followed by ,p,p'-DDE, heptachlor, endosulfan and γ-HCH whose frequency rates were 100, 91, 83 and 54%, respectively. The concentration of p,p'-DDT in the crops grown in these soils was in the following order: chili > maize > tomato > alfalfa. The results obtained in this study show that p,p'-DDT values are lower or similar to those found in other agricultural regions of Mexico. Methyl and ethyl parathion were the most frequent organophosphate pesticide detected in 100% and 62.5% of the samples with average concentrations of 25.20 and 47.48 μg kg(-1), respectively. More research is needed to establish the background levels of pesticides in agricultural soils and their potential ecological and human health effects in this region.

  17. Matrix solid-phase dispersion extraction of organophosphorus pesticide using SiO2-poly(N-vinylimidazole)

    International Nuclear Information System (INIS)

    Gutiérrez-Solís, M C; Muñoz-Rodríguez, D; Carrera-Figueiras, C; Ávila-Ortega, A; Medina-Peralta, S

    2013-01-01

    A sorbent material based on silica particles modified with poly(N-vinylimidazole) (SiO 2 -PVI) has been evaluated for the treatment of samples by matrix solid-phase dispersion (MSPD). The extraction of four organophosphorus pesticides was done from a spiked tomato and the extracts were analyzed by gas chromatography coupled to mass spectrometry. Six elution solvents were evaluated and acetone was selected due to better recovery of the four pesticides and low background signal in the chromatograms. A factorial design 2 4 was used for selection of extraction conditions. The factors were contact time, acetone volume, treatment (with or without freeze-drying) and adsorbent (SiO 2 or SiO 2 -PVI). The best recoveries were obtained using 15 minutes of contact, 2 mL of solvent and sorbent without freeze-drying. The recoveries were between 60 and 83% for SiO 2 -PVI in spiked tomato with 0.2 and 0.8μg/g.

  18. De novo amplification within a silent human cholinesterase gene in a family subjected to prolonged exposure to organophosphorus insecticides

    International Nuclear Information System (INIS)

    Prody, C.A.; Dreyfus, P.; Soreq, H.; Zamir, R.; Zakut, H.

    1989-01-01

    A 100-fold DNA amplification in the CHE gene, coding for serum butyrylcholinesterase (BtChoEase), was found in a farmer expressing silent CHE phenotype. Individuals homozygous for this gene display a defective serum BtChoEase and are particularly vulnerable to poisoning by agricultural organophosphorus insecticides, to which all members of this family had long been exposed. DNA blot hybridization with regional BtChoEase cDNA probes suggested that the amplification was most intense in regions encoding central sequences within BtChoEase cDNA, whereas distal sequences were amplified to a much lower extent. This is in agreement with the onion skin model, based on amplification of genes in cultured cells and primary tumors. The amplification was absent in the grandparents but present at the same extent in one of their sons and in a grandson, with similar DNA blot hybridization patterns. In situ hybridization experiments localized the amplified sequences to the long arm of chromosome 3, close to the site where the authors previously mapped the CHE gene. Altogether, these observations suggest that the initial amplification event occurred early in embryogenesis, spermatogenesis, or oogenesis, where the CHE gene is intensely active and where cholinergic functioning was indicated to be physiologically necessary. These findings demonstrate a de novo amplification in apparently healthy individuals within an autosomal gene producing a target protein to an inhibitor

  19. Molecular characterization of the amplified carboxylesterase gene associated with organophosphorus insecticide resistance in the brown planthopper, Nilaparvata lugens.

    Science.gov (United States)

    Small, G J; Hemingway, J

    2000-12-01

    Widespread resistance to organophosphorus insecticides (OPs) in Nilaparvata lugens is associated with elevation of carboxylesterase activity. A cDNA encoding a carboxylesterase, Nl-EST1, has been isolated from an OP-resistant Sri Lankan strain of N. lugens. The full-length cDNA codes for a 547-amino acid protein with high homology to other esterases/lipases. Nl-EST1 has an N-terminal hydrophobic signal peptide sequence of 24 amino acids which suggests that the mature protein is secreted from cells expressing it. The nucleotide sequence of the homologue of Nl-EST1 in an OP-susceptible, low esterase Sri Lankan strain of N. lugens is identical to Nl-EST1. Southern analysis of genomic DNA from the Sri Lankan OP-resistant and susceptible strains suggests that Nl-EST1 is amplified in the resistant strain. Therefore, resistance to OPs in the Sri Lankan strain is through amplification of a gene identical to that found in the susceptible strain.

  20. Development of a passive air sampler to measure airborne organophosphorus pesticides and oxygen analogs in an agricultural community.

    Science.gov (United States)

    Armstrong, Jenna L; Yost, Michael G; Fenske, Richard A

    2014-09-01

    Organophosphorus pesticides are some of the most widely used insecticides in the US, and spray drift may result in human exposures. We investigate sampling methodologies using the polyurethane foam passive air sampling device to measure cumulative monthly airborne concentrations of OP pesticides chlorpyrifos, azinphos-methyl, and oxygen analogs. Passive sampling rates (m(3)d(-1)) were determined using calculations using chemical properties, loss of depuration compounds, and calibration with side-by-side active air sampling in a dynamic laboratory exposure chamber and in the field. The effects of temperature, relative humidity, and wind velocity on outdoor sampling rates were examined at 23 sites in Yakima Valley, Washington. Indoor sampling rates were significantly lower than outdoors. Outdoor rates significantly increased with average wind velocity, with high rates (>4m(3)d(-1)) observed above 8ms(-1). In exposure chamber studies, very little oxygen analog was observed on the PUF-PAS, yet substantial amounts chlorpyrifos-oxon and azinphos methyl oxon were measured in outdoor samples. PUF-PAS is a practical and useful alternative to AAS because it results in little artificial transformation to the oxygen analog during sampling, it provides cumulative exposure estimates, and the measured sampling rates were comparable to rates for other SVOCs. It is ideal for community based participatory research due to low subject burden and simple deployment in remote areas. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. The structural requirements of organophosphorus insecticides (OPI) for reducing chicken embryo NAD(+) content in OPI-induced teratogenesis in chickens.

    Science.gov (United States)

    Seifert, Josef

    2016-05-01

    The objective of this study was to determine the structural requirements of organophosphorus insecticides (OPI) for reducing chicken embryo nicotinamide adenine dinucleotide (NAD(+)) content in OPI-induced teratogenesis and compare them with those needed for OPI inhibition of yolk sac membrane kynurenine formamidase (KFase), the proposed primary target for OPI teratogens in chicken embryos. The comparative molecular field analysis (COMFA) of three-dimensional quantitative structure-activity relationship (3D QSAR) revealed the electrostatic and steric fields as good predictors of OPI structural requirements to reduce NAD(+) content in chicken embryos. The dominant electrostatic interactions were localized at nitrogen-1, nitrogen-3, nitrogen of 2-amino substituent of the pyrimidinyl of pyrimidinyl phosphorothioates, and at the oxygen of crotonamide carbonyl in crotonamide phosphates. Bulkiness of the substituents at carbon-6 of the pyrimidinyls and/or N-substituents of crotonamides was the steric structural component that contributed to superiority of those OPI for reducing embryonic NAD(+) levels. Both electrostatic and steric requirements are similar to those defined in our previous study for OPI inhibition of chicken embryo yolk sac membrane KFase. The findings of this study provide another piece of evidence for the cause-and-effect relationship between yolk sac membrane KFase inhibition and reduced embryo NAD(+) content in NAD-associated OPI-induced teratogenesis in chickens. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Field studies on health effects from the application of two organophosphorus insecticide formulations by hand-held ULV to cotton.

    Science.gov (United States)

    Kummer, R; van Sittert, N J

    1986-10-01

    Two field studies to assess the health implications for farmers applying two different formulations containing organophosphorus (OP) pesticides to cotton by hand-held ULV are described. The first study, carried out in the Ivory Coast, involved the application of an endrin/DDT/methylparathion (MEP) formulation in an aromatic hydrocarbon solvent. The second study took place in Indonesia with a 20% monocrotophos formulation in a mixture of a glycol and a glycol ether. Both studies were carried out under actual field conditions. The purpose of the studies was to get a good assessment of the health hazards of the particular formulation, used under the specific circumstances and agronomic requirements of the area of application and taking into account all local, climatic and cultural conditions that could be of possible influence. The results showed that in both studies skin exposures took place during application and especially during handling, filling and cleaning, and that inhalation of spray mist was negligible. Absorption was confirmed by the presence in urine of metabolites of endrin and methylparathion in the Ivory Coast study, and of dimethyl phosphate in the Indonesia study. No clinical signs or symptoms of intoxication were discovered in either study, nor were inhibitions of cholinesterase (ChE) activity of health significance established under the conditions of the studies. In addition, various practical aspects such as choice of apparatus, of formulation, the application procedures etc. are discussed.

  3. Innovative approach for the electrochemical detection of non-electroactive organophosphorus pesticides using oxime as electroactive probe

    International Nuclear Information System (INIS)

    Dong, Jing; Hou, Juying; Jiang, Jianxia; Ai, Shiyun

    2015-01-01

    Highlights: • Novel approach for electrochemical detection of non-electroactive OPs was proposed. • PAM was used as electroactive probe for the first time. • The detection system displayed high sensitivity and promptness. • The developed sensor was used in real samples with satisfactory results. - Abstract: An innovative approach for sensitive and simple electrochemical detection of non-electroactive organophosphorus pesticides (OPs) was described in this report. The novel strategy emphasized the fabrication of an oxime-based sensor via attaching pralidoxime (PAM) on graphene quantum dots (GQDs) modified glassy carbon electrode. The introduction of GQDs significantly increased the effective electrode area, and then enlarged the immobilization quantity of PAM. Thus, the oxidation current of PAM was obviously increased. Relying on the nucleophilic substitution reaction between oxime and OPs, fenthion was detected using PAM as the electroactive probe. Under optimum conditions, the difference of oxidation current of PAM was proportional to fenthion concentration over the range from 1.0 × 10 −11 M to 5.0 × 10 −7 M with a detection limit of 6.8 × 10 −12 M (S/N = 3). Moreover, the favorable detection performance in water and soil samples heralded the promising applications in on-site OPs detection

  4. Application of Box-Behnken design for the removal of two organophosphorus pesticides by used Tea leaves

    Science.gov (United States)

    Albanis, Triantafyllos; Valileios, Sakkas; Islam, Azharul M.

    2016-04-01

    Removal of two organophosphorus pesticides bromophos methyl [BM: O, O- dimethyl - O - (2, 5-dichloro -4 bromophenyl) phosphorothioate] and quinalphos [QP: O, O-diethyl O-2-quinoxalinyl phosphorothioate] on used tea leaves were studied by batch equilibration method. Adsorption isotherms were conformed well to Langmuir for quinalphos and Freundlich equation for bromophos methyl. The kinetic data fitted well by the pseudo second order model for both pesticides. Box-Behnken design was successfully employed for experimental design and analysis of results. The interactions of pH, initial concentration and adsorbent dose on two pesticides adsorption by used tea leaves were investigated by this model. The optimum pH, initial concentration and adsorbent dose with their corresponding removal efficiency were found to be 7.88, 11.94 mg L-1, 0.37g and 100% for bromophos methyl respectively, for quinalphos 8.72, 6.44 mg L-1, 0.39g and 93.98% respectively. Keywords: Box-Behnken; quinalphos; bromophos methyl; Kinetics; used tea leaves

  5. Feline Immunodeficiency Virus (FIV Neutralization: A Review

    Directory of Open Access Journals (Sweden)

    Margaret J. Hosie

    2011-10-01

    Full Text Available One of the major obstacles that must be overcome in the design of effective lentiviral vaccines is the ability of lentiviruses to evolve in order to escape from neutralizing antibodies. The primary target for neutralizing antibodies is the highly variable viral envelope glycoprotein (Env, a glycoprotein that is essential for viral entry and comprises both variable and conserved regions. As a result of the complex trimeric nature of Env, there is steric hindrance of conserved epitopes required for receptor binding so that these are not accessible to antibodies. Instead, the humoral response is targeted towards decoy immunodominant epitopes on variable domains such as the third hypervariable loop (V3 of Env. For feline immunodeficiency virus (FIV, as well as the related human immunodeficiency virus-1 (HIV-1, little is known about the factors that lead to the development of broadly neutralizing antibodies. In cats infected with FIV and patients infected with HIV-1, only rarely are plasma samples found that contain antibodies capable of neutralizing isolates from other clades. In this review we examine the neutralizing response to FIV, comparing and contrasting with the response to HIV. We ask whether broadly neutralizing antibodies are induced by FIV infection and discuss the comparative value of studies of neutralizing antibodies in FIV infection for the development of more effective vaccine strategies against lentiviral infections in general, including HIV-1.

  6. Net Neutrality: Media Discourses and Public Perception

    Directory of Open Access Journals (Sweden)

    Christine Quail

    2010-01-01

    Full Text Available This paper analyzes media and public discourses surrounding net neutrality, with particular attention to public utility philosophy, from a critical perspective. The article suggests that further public education about net neutrality would be beneficial. The first portion of this paper provides a survey of the existing literature surrounding net neutrality, highlighting the contentious debate between market-based and public interest perspectives. In order to contextualize the debate, an overview of public utility philosophy is provided, shedding light on how the Internet can be conceptualized as a public good. Following this discussion, an analysis of mainstream media is presented, exploring how the media represents the issue of net neutrality and whether or not the Internet is discussed through the lens of public utility. To further examine how the net neutrality debate is being addressed, and to see the potential impacts of media discourses on the general public, the results of a focus group are reported and analyzed. Finally, a discussion assesses the implications of the net neutrality debate as presented through media discourses, highlighting the future of net neutrality as an important policy issue.

  7. Neutral Supersymmetric Higgs Boson Searches

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Stephen Luke [Imperial College, London (United Kingdom)

    2008-07-01

    In some Supersymmetric extensions of the Standard Model, including the Minimal Supersymmetric Standard Model (MSSM), the coupling of Higgs bosons to b-quarks is enhanced. This enhancement makes the associated production of the Higgs with b-quarks an interesting search channel for the Higgs and Supersymmetry at D0. The identification of b-quarks, both online and offline, is essential to this search effort. This thesis describes the author's involvement in the development of both types of b-tagging and in the application of these techniques to the MSSM Higgs search. Work was carried out on the Level-3 trigger b-tagging algorithms. The impact parameter (IP) b-tagger was retuned and the effects of increased instantaneous luminosity on the tagger were studied. An extension of the IP-tagger to use the z-tracking information was developed. A new b-tagger using secondary vertices was developed and commissioned. A tool was developed to allow the use of large multi-run samples for trigger studies involving b-quarks. Offline, a neural network (NN) b-tagger was trained combining the existing offline lifetime based b-tagging tools. The efficiency and fake rate of the NN b-tagger were measured in data and MC. This b-tagger was internally reviewed and certified by the Collaboration and now provides the official b-tagging for all analyses using the Run IIa dataset at D0. A search was performed for neutral MSSM Higgs bosons decaying to a b{bar b} pair and produced in association with one or more b-quarks. Limits are set on the cross-section times the branching ratio for such a process. The limits were interpreted in various MSSM scenarios. This analysis uses the NN b-tagger and was the first to use this tool. The analysis also relies on triggers using the Level-3 IP b-tagging tool described previously. A likelihood discriminant was used to improve the analysis and a neural network was developed to cross-check this technique. The result of the analysis has been submitted to PRL

  8. Silver(I)-directed growth of metal-organic complex nanocrystals with bidentate ligands of hydroquinine anthraquinone-1,4-diyl diethers as linkers at the water-chloroform interface

    Science.gov (United States)

    Tang, Ying; Wang, Hui-Ting; Chen, Meng; Qian, Dong-Jin; Zhang, Li; Liu, Minghua

    2014-09-01

    Immiscible liquid-liquid interfaces provide unique double phase regions for the design and construction of nanoscale materials. Here, we reported Ag(I)-directed growth of metal-organic complex nanocrystals by using AgNO3 as a connector in the aqueous solution and bidentate ligand of 1,4-bis(9-O-dihydroquininyl)anthraquinone [(DHQ)2AQN] and its enantiomer of (DHQD)2AQN in the chloroform solutions as linkers. The Ag-(DHQ)2AQN and Ag-(DHQD)2AQN complex nanocrystals were formed at the liquid-liquid interfaces and characterized by using UV-vis absorption and fluorescence spectroscopy and X-ray photoelectron spectroscopy, as well as by using scanning electron microscopy. Screw-like nanocrystals were formed at the initial 30 min after the interfacial coordination reaction started, then they grew into nanorods after several days, and finally became cubic microcrystals after 2 weeks. The pure ligand showed two emission bands centered at about 363 and 522 nm in the methanol solution, the second one of which was quenched and shifted to about 470 nm in the Ag-complex nanocrystals. Two couples of reversible redox waves were recorded for the Ag-complex nanocrystals; one centered at about -0.25 V (vs. Ag/AgCl) was designated to one electron transfer process of Ag - (DHQ)2AQN and Ag - (DHQ)2AQN+, and the other one centered at about 0.2 V was designated to one electron transfer process of Ag - (DHQ)2AQN and Ag+ - (DHQ)2AQN.

  9. Evaluation of smallpox vaccines using variola neutralization.

    Science.gov (United States)

    Damon, Inger K; Davidson, Whitni B; Hughes, Christine M; Olson, Victoria A; Smith, Scott K; Holman, Robert C; Frey, Sharon E; Newman, Frances; Belshe, Robert B; Yan, Lihan; Karem, Kevin

    2009-08-01

    The search for a 'third'-generation smallpox vaccine has resulted in the development and characterization of several vaccine candidates. A significant barrier to acceptance is the absence of challenge models showing induction of correlates of protective immunity against variola virus. In this light, virus neutralization provides one of few experimental methods to show specific 'in vitro' activity of vaccines against variola virus. Here, we provide characterization of the ability of a modified vaccinia virus Ankara vaccine to induce variola virus-neutralizing antibodies, and we provide comparison with the neutralization elicited by standard Dryvax vaccination.

  10. Neutral currents, supernovae neutrinos, and nucleosynthesis

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1988-01-01

    The inelastic interactions of neutrinos during stellar collapse and neutron star cooling are discussed. The primary mechanism for dissipative neutrino reactions is nuclear excitation by neutral current scattering, a process not included in standard descriptions of supernovae. Charge-current and neutral current ''preheating'' of iron lying outside the shock front appears to be significant in the few milliseconds near shock breakout. This could help produce a more energetic shock. During the cooling phase, the neutral current interactions of muon and taon neutrinos appear to be responsible for some interesting nucleosynthesis. I discuss two examples the production of fluorine and neutrino-induced r-process nucleosynthesis. 26 refs., 1 fig., 3 tabs

  11. Rare decays of neutral π and eta

    International Nuclear Information System (INIS)

    Poutissou, J.M.

    1983-09-01

    The decays of the pseudoscalar neutral mesons π degree and eta degree have provided a test of fundamental principles. The main branch, π degree → 2γ, was investigated in the late 60's in the context of current algebra and the decay rate calculated from the singular triangle diagram is in excellent agreement with experiment. Rare leptonic decays of the neutral pseudoscalar mesons are of interest because of the information they reveal about neutral currents or other exotic interactions between leptons and quarks. The author discusses recent information on the π degree → e + e - decay

  12. Soviet exoatmospheric neutral particle beam research

    International Nuclear Information System (INIS)

    Leiss, J.E.; Abrams, R.H.; Ehlers, K.W.; Farrell, J.A.; Gillespie, G.H.; Jameson, R.A.; Keefe, D.; Parker, R.K.

    1988-02-01

    This technical assessment was performed by a panel of eight U.S. scientists and engineers who are familiar with Soviet research through their own research experience, their knowledge of the published scientific literature and conference proceedings, and personal contacts with Soviet scientists and other foreign colleagues. Most of the technical components of a neutral particle beam generating system including the ion source, the accelerator, the accelerator radio frequency power supply, the beam conditioning and aiming system, and the beam neutralizer system are addressed. It does not address a number of other areas important to an exoatmospheric neutral beam system

  13. Fast Neutral Pressure Measurements in NSTX

    International Nuclear Information System (INIS)

    R. Raman; H.W. Kugel; T. Provost; R. Gernhardt; T.R. Jarboe; M.G. Bell

    2002-01-01

    Several fast neutral pressure gauges have been installed on NSTX [National Spherical Torus Experiment] to measure the vessel and divertor pressure during inductive and coaxial helicity injected (CHI) plasma operations. Modified, PDX [Poloidal Divertor Experiment]-type Penning gauges have been installed on the upper and lower divertors. Neutral pressure measurements during plasma operations from these and from two shielded fast Micro ion gauges at different toroidal locations on the vessel mid-plane are described. A new unshielded ion gauge, referred to as the In-vessel Neutral Pressure (INP) gauge is under development

  14. Negative ion formation and neutralization processes, (2)

    International Nuclear Information System (INIS)

    Sugiura, Toshio

    1982-09-01

    This review is 2nd part of the report published at January 1982 (JAERI-M-9902). A compilation includes the survey of the data of the cross sections of H - and D - ion formations and the neutralization of these ions. This is also presented new information about the photosensitization by laser beam in dissociative-resonance electron capture of sulfur hexafluoride reported by Chen et al., for reference to enhancement of D - ions in discharge. For neutralization, the data of mutual neutralization and photodetachment are also presented. (author)

  15. Liquid-liquid extraction from molten alkaline nitrates by using nitrogenous and organophosphorus derivatives

    International Nuclear Information System (INIS)

    Vittori, Olivier

    1971-01-01

    This research thesis reports the use of a system made of the LiNO 3 -KNO 3 eutectic at 160 deg. C and poly-phenyls in order to study the behaviour of phosphine and arsine oxides as extracting agents in a liquid-liquid process. In a first part, the author presents the studied system, its physical characteristics and its preparation, and the various analytical methods which have used. He discusses existing computation methods adapted to the separation of molten salts and organic phase, and proposes a specific method. Then, he reports the study of the behaviour of a phosphine oxide with Cobalt II and Nickel II, and discusses its application to the separation of this pair, Co II and Ni II. He highlights the different possibilities of three agents which are derivatives of phosphine and arsine in their ability to extract rare earths. A study of separation of rare earths is then addressed. The author reports the application of extraction equilibriums to the study of equilibriums in environments of molten salts with the Co II - chloride ions system. The author finally addresses the synergic phenomenon that pairs of neutral complexing agents of neighbouring structure or different donor central atom may display in liquid-liquid extraction

  16. Neutral Color Semitransparent Microstructured Perovskite Solar Cells

    KAUST Repository

    Eperon, Giles E.; Burlakov, Victor M.; Goriely, Alain; Snaith, Henry J.

    2014-01-01

    Neutral-colored semitransparent solar cells are commercially desired to integrate solar cells into the windows and cladding of buildings and automotive applications. Here, we report the use of morphological control of perovskite thin films to form

  17. Charge neutralization of small ion beam clumps

    Energy Technology Data Exchange (ETDEWEB)

    Welch, D R [Mission Research Corp., Albuquerque, NM (United States); Olson, C L; Hanson, D L [Sandia National Labs., Albuquerque, NM (United States)

    1997-12-31

    The mega-ampere currents associated with light ion fusion (LIF) require excellent charge neutralization to prevent divergence growth. As the size and space-charge potential of a beam clump or `beamlet` become small (submillimeter size and kilovolt potentials), the neutralization becomes increasingly difficult. Linear theory predicts that plasma electrons cannot neutralize potentials < {phi}{sub crit} = (1/2)m{sub e}v{sub i}{sup 2}/e, where m{sub e} is the electron mass and v{sub i} is the ion beam velocity. A non-uniform beam would, therefore, have regions with potentials sufficient to add divergence to beam clumps. The neutralization of small beamlets produced on the SABLE accelerator and in numerical simulation has supported the theory, showing a plateau in divergence growths as the potential in the beamlet exceeds {phi}{sub crit}. (author). 1 tab., 2 figs., 4 refs.

  18. UV Ionizer for Neutral Wind Mass Spectrometers

    Data.gov (United States)

    National Aeronautics and Space Administration — Current neutral particle instrumentation relies on hot cathode filaments or an electron gun for ionizing the target medium.  These ionization sources represent a...

  19. Kinetics of neutralization of Po-218

    International Nuclear Information System (INIS)

    Chu, K.D.

    1987-01-01

    In a well-defined experimental system the neutralization of polonium-218 ions was investigated as a function of the physical and chemical properties of the controlled composition atmosphere. The mobilities of Po + and PoO 2 + are determined by combining experimental results with a computer model of the system. Three neutralization mechanisms were individually studied. The small ion recombination rate has been found to be proportional to the square root of radon concentration. The electron scavenging mechanism is responsible for the neutralization of Po + in NO 2 or H 2 O in nitrogen. When PoO 2 + is formed, the electron transfer mechanism dominates the neutralization process. The electron is transferred to PoO 2 + from molecules with lower ionization potentials. The ionization potential of PoO 2 + is also determined to be 10.44 +/- 0.05 eV

  20. An experimenter's history of neutral currents

    International Nuclear Information System (INIS)

    Sciulli, F.

    1979-01-01

    The history of the experimental study of neutral currents, defined as the class of weak interactions engaged in by lepton pairs of net zero charge, is traced under the headings; historical motivations, experimental searches, first positive indications, neutral currents corroborated, neutrino experiments on neutral currents and some general experimental comments. It is concluded that the neutral current does exist and predicted on the basis of gauge theory ideas, and though to connect the weak and electromagnetic interactions, its very general experimental properties are quite consistent with those ideas. Among these are flavor conserving complicated isospin structure, complicated V, A structure and a structure which depends on the type (or quantum numbers) of the target. 50 references. (UK)

  1. RESEARCH ON ENVIRONMENTAL CONTAMINATION IN RAW MILK IN TURIN DEPARTEMENT : HEAVY METALS, P.C.B, ORGANOCHLORINE AND ORGANOPHOSPHORUS PESTICIDES – YEARS 2005 – 2008

    Directory of Open Access Journals (Sweden)

    S. Cavallera

    2013-02-01

    Full Text Available In the period between 2005 and 2008 was carried out a survey on 252 samples of raw bovine milk collected in Turin departement to certain levels of contamination by heavy metals (Cd, Cr, Fe, Hg, Pb, Zn, PCB and organophosphorus and organochlorine pesticides. These results argue that the levels of heavy metals, PCB and pesticides are well below what is expected by the European legislation and that the situation is under control and that raw milk meets the hygiene requirements for human health.

  2. Activity of Ca(2+,Mg(2+-ATPase of sarcoplasmic reticulum and contraction strength of the frog skeletal muscles under the effect of organophosphorus insecticides

    Directory of Open Access Journals (Sweden)

    D. M. Nozdrenko

    2015-08-01

    Full Text Available The results of an experimental study of organo­phosphorus insecticides, including pirimiphosmethyl, diazinon and chlorpyrifos caused a decline of the contraction properties in m. tibialis anterior fiber bundles of Rana temporaria, as well as sarcoplasmic reticulum Ca2+,Mg2+-ATPase enzymatic activity reduction are outlined in this paper. Concentration-dependent strengths response diminishing in isolated skeletal muscle fiber bundles as a result of non-cholinergic influence of organophosphorus insecticides were found. A decrease of Ca2+,Mg2+-ATPase enzymatic activity in sarcoplasmic reticulum was observed after administration of each insecticide. The most significant inhibition of this enzyme was observed when using chlorpyrifos.

  3. Recovery evaluation of organophosphorus pesticides from bee pollen by matrix solid-phase dispersion extraction using sorbents based on silica and titania

    International Nuclear Information System (INIS)

    Torres-Perea, C; Muñoz-Rodríguez, D; Carrera-Figueiras, C; Medina-Peralta, S; Moguel-Ordóñez, Y B

    2013-01-01

    This work focused on the evaluation of the recovery of organophosphorus pesticides from bee pollen after matrix solid phase-dispersion extraction (MSPD). Materials based on silica, titania and titania modified with polivylnylimidazole or polyestirene were used as adsorbents for the extraction of pesticides. Small amounts of fortified pollen (0.1 g, at 1 micro-g/g of pesticides), adsorbent (0.4 g) and solvent elution (1 mL de acetonitrile – ACN) were used in the extractions. For recovery evaluation, pollen extracts were analyzed by gas chromatography coupled with mass spectrometry.

  4. [COMPARATIVE SENSITIVITY OF CHOLINESTERASES IN VERTEBRATES AND INVERTEBRATES TO HIGHLY SPECIFIC ORGANOPHOSPHORUS INHIBITORS DIISOPROPYL FLUOROPHOSPHATE (DFP) AND (2-ETHOXYMETHYL PHOSPHORYL THIOETHYL) ETHYL (METHYL) SULPHONIUM SULPHOMETHYLAT (GD-42)].

    Science.gov (United States)

    Basova, N E; Kormilitsyn, B N; Perchenok, A Yu; Rozengart, E V; Saakov, V S; Suvorov, A A

    2015-01-01

    The review presents data on comparative reactivity of 68 cholinesterase preparation from various organs and tissues in a number of vertebrates and invertebrates based on sensitivity to two highly specific and most studied organophosphorus inhibitors--diisopropyl fluorophosphates (DFP) and (2-ethoxymethyl phosphoryl thioethyl) ethyl (methyl) sulphonium sulphomethylat (GD-42). Analysis of these data suggests a great diversity in enzymologic characteristics of cholinesterase preparation in representatives of vertebrates and invertebrates, this variety observed even for closely related enzymes in animals of almost the same level of development.

  5. ITER neutral beam system US conceptual design

    International Nuclear Information System (INIS)

    Purgalis, P.

    1990-09-01

    In this document we present the US conceptual design of a neutral beam system for International Thermonuclear Experimental Reactor (ITER). The design incorporates a barium surface conversion D - source feeding a linear array of accelerator channels. The system uses a dc accelerator with electrostatic quadrupoles for strong focusing. A high voltage power supply that is integrated with the accelerator is presented as an attractive option. A gas neutralizer is used and residual ions exiting the neutralizer are deflected to water-cooled dumps. Cryopanels are located at the accelerator exit to pump excess gas from the source and the neutralizer, and in the ion dump cavity to pump re-neutralized ions and neutralizer gas. All the above components are packaged in compact identical, independent modules which can be removed for remote maintenance. The neutral beam system delivers 75 MW of DO at 1.3 MeV, into three ports with a total of 9 modules arranged in stacks of three modules per port . To increase reliability each module is designed to deliver up to 10 MW; this allows eight modules operating at partial capacity to deliver the required power in the event one module is out of service, and provides 20% excess capacity to improve availability. Radiation protection is provided by shielding and by locating critical components in the source and accelerator 46.5 m from the torus centerline. Neutron shielding in the drift duct and neutralizer provides the added feature of limiting conductance and thus reducing gas flow to and from the torus

  6. Neutral-particle-beam production and injection

    International Nuclear Information System (INIS)

    Post, D.; Pyle, R.

    1982-07-01

    This paper is divided into two sections: the first is a discussion of the interactions of neutral beams with confined plasmas, the second is concerned with the production and diagnosis of the neutral beams. In general we are dealing with atoms, molecules, and ions of the isotopes of hydrogen, but some heavier elements (for example, oxygen) will be mentioned. The emphasis will be on single-particle collisions; selected atomic processes on surfaces will be included

  7. Neutral signature Walker-VSI metrics

    International Nuclear Information System (INIS)

    Coley, A; McNutt, D; Musoke, N; Brooks, D; Hervik, S

    2014-01-01

    We will construct explicit examples of four-dimensional neutral signature Walker (but not necessarily degenerate Kundt) spaces for which all of the polynomial scalar curvature invariants vanish. We then investigate the properties of some particular subclasses of Ricci flat spaces. We also briefly describe some four-dimensional neutral signature Einstein spaces for which all of the polynomial scalar curvature invariants are constant. (paper)

  8. Nitrogen-neutrality: a step towards sustainability

    Science.gov (United States)

    Leip, Adrian; Leach, Allison; Musinguzi, Patrick; Tumwesigye, Trust; Olupot, Giregon; Tenywa, John Stephen; Mudiope, Joseph; Hutton, Olivia; Cordovil, Claudia M. d. S.; Bekunda, Mateete; Galloway, James

    2014-11-01

    We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, N-neutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66 kg N. A total of US 3050 was collected from the participants and used to offset the conference’s N footprint by supporting the UN Millennium Village cluster Ruhiira in South-Western Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates.

  9. Γ-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...... and better output performance comparing with traditional two-level inverters. Integrating these two types of configurations can help neutral point inverters achieve enhanced votlage buck-boost capability....

  10. TFTR neutral beam injection system conceptual design

    International Nuclear Information System (INIS)

    1975-01-01

    Three subsystems are described in the following chapters: (1) Neutral Beam Injection Line; (2) Power Supplies; and (3) Controls. Each chapter contains two sections: (1) Functions and Design Requirements; this is a brief listing of the requirements of components of the subsystem. (2) Design Description; this section describes the design and cost estimates. The overall performance requirements of the neutral beam injection system are summarized. (MOW)

  11. Neutral currents without gauge theory prejudices

    International Nuclear Information System (INIS)

    Sakurai, J.J.

    1976-01-01

    The measurement of weak neutral current processes allows a determination of the space-time structure and the isospin structure of these currents. The inclusive production data and the elastic neutrino electron scattering rules out a pure V or A structure of the current. A pure isoscalar current is in disagreement with the experimental data for the one pion production off neutrinos. Further aspects of the neutral current can be determined in neutrino-nucleus-scattering experiments. (BJ) [de

  12. Negative ion formation and neutralization processes, (1)

    International Nuclear Information System (INIS)

    Sugiura, Toshio

    1982-01-01

    This review has been made preliminary for the purpose of contribute to the plasma heating by ''negative ion based neutral beam injection'' in the magnetic confinement fusion reactor. A compilation includes the survey of the general processes of negative ion formation, the data of the cross section of H - ion formation and the neutralization of H - ion, and some of new processes of H - ion formation. The data of cross section are mainly experimental, but partly include the results of theoretical calculation. (author)

  13. Nitrogen-neutrality: a step towards sustainability

    International Nuclear Information System (INIS)

    Leip, Adrian; Leach, Allison; Hutton, Olivia; Galloway, James; Musinguzi, Patrick; Tumwesigye, Trust; Olupot, Giregon; Stephen Tenywa, John; Mudiope, Joseph; Cordovil, Claudia M d S; Bekunda, Mateete

    2014-01-01

    We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, N-neutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66 kg N. A total of US$ 3050 was collected from the participants and used to offset the conference’s N footprint by supporting the UN Millennium Village cluster Ruhiira in South-Western Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates. (paper)

  14. Applications of neutral beam and rf technologies

    International Nuclear Information System (INIS)

    Haselton, H.H.

    1987-04-01

    This presentation provides an update on the applications of neutral beams and radiofrequency (rf) power in the fusion program; highlights of the ion cyclotron heating (ICH) experiments now in progress, as well as the neutral beam experiments; and heating requirements of future devices and some of the available options. Some remarks on current drive are presented because this area of technology is one that is being considered for future devices

  15. Apparatus for neutralization of accelerated ions

    International Nuclear Information System (INIS)

    Fink, J.H.; Frank, A.M.

    1979-01-01

    Apparatus is described for neutralization of a beam of accelerated ions, such as hydrogen negative ions (H - ), using relatively efficient strip diode lasers which emit monochromatically at an appropriate wavelength (lambda = 8000 A for H - ions) to strip the excess electrons by photodetachment. A cavity, formed by two or more reflectors spaced apart, causes the laser beams to undergo multiple reflections within the cavity, thus increasing the efficiency and reducing the illumination required to obtain an acceptable percentage (approx. 85%) of neutralization

  16. Negative ion based neutral beams for plasma heating

    International Nuclear Information System (INIS)

    Prelec, K.

    1978-01-01

    Neutral beam systems based on negative ions have been considered because of a high expected power efficiency. Methods for the production, acceleration and neutralization of negative ions will be reviewed and possibilities for an application in neutral beam lines explored

  17. Design of the ITER Neutral Beam injectors

    International Nuclear Information System (INIS)

    Hemsworth, R.S.; Feist, J.; Hanada, M.; Heinemann, B.; Inoue, T.; Kuessel, E.; Kulygin, V.; Krylov, A.; Lotte, P.; Miyamoto, K.; Miyamoto, N.; Murdoch, D.; Nagase, A.; Ohara, Y.; Okumura, Y.; Pamela, J.; Panasenkov, A.; Shibata, K.; Tanii, M.

    1996-01-01

    This paper describes the Neutral Beam Injection system which is presently being designed in Europe, Japan and Russia, with co-ordination by the Joint Central Team of ITER at Naka, Japan. The proposed system consists of three negative ion based neutral injectors, delivering a total of 50 MW of 1 MeV D 0 to the ITER plasma for pulse length of ≥1000 s. The injectors each use a single caesiated volume arc discharge negative ion source, and a multi-grid, multi-aperture accelerator, to produce about 40 A of 1 MeV D - . This will be neutralized in a sub-divided gas neutralizer, which has a conversion efficiency of about 60%. The charged fraction of the beam emerging from the neutralizer is dumped in an electrostatic residual ion dump. A water cooled calorimeter can be moved into the beam path to intercept the neutral beam, allowing commissioning of the injector independent of ITER. copyright 1996 American Institute of Physics

  18. Neutral particle kinetics in fusion devices

    International Nuclear Information System (INIS)

    Tendler, M.; Heifetz, D.

    1986-05-01

    The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub α/ emission rates, plenum pressures, and charge-exchange emission spectra

  19. Neutral particle kinetics in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Tendler, M.; Heifetz, D.

    1986-05-01

    The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub ..cap alpha../ emission rates, plenum pressures, and charge-exchange emission spectra.

  20. Automated Facial Coding Software Outperforms People in Recognizing Neutral Faces as Neutral from Standardized Datasets

    Directory of Open Access Journals (Sweden)

    Peter eLewinski

    2015-09-01

    Full Text Available Little is known about people’s accuracy of recognizing neutral faces as neutral. In this paper, I demonstrate the importance of knowing how well people recognize neutral faces. I contrasted human recognition scores of 100 typical, neutral front-up facial images with scores of an arguably objective judge – automated facial coding (AFC software. I hypothesized that the software would outperform humans in recognizing neutral faces because of the inherently objective nature of computer algorithms. Results confirmed this hypothesis. I provided the first-ever evidence that computer software (90% was more accurate in recognizing neutral faces than people were (59%. I posited two theoretical mechanisms, i.e. smile-as-a-baseline and false recognition of emotion, as possible explanations for my findings.

  1. Probabilistic acute risk assessment of cumulative exposure to organophosphorus and carbamate pesticides from dietary vegetables and fruits in Shanghai populations.

    Science.gov (United States)

    Li, Fan; Yuan, Yaqun; Meng, Pai; Wu, Min; Li, Shuguang; Chen, Bo

    2017-05-01

    Organophosphorus pesticides (OPs) and carbamate pesticides (CPs) are among the most widely used pesticides in China, playing a major role in protecting agricultural commodities. In this study, we determined the cumulative acute exposure to OPs and CPs of Shanghai residents from vegetables and fruits (VFs). The food consumption data were obtained from the Shanghai Food Consumption Survey (SHFCS) of 2012-14 including a total of 1973 participants aged 2-90 years. The pesticide residue data were obtained from the Shanghai monitoring programme during 2008-11 with 34 organophosphates and 11 carbamates analysed in a total of 5335 samples of VFs. A probabilistic approach was performed as recommended by the EFSA, using the optimistic model with non-detects set as zero and with processing factors (PFs) being used and the pessimistic model with non-detects replaced by limit of detection (LOD) and without PFs. We used the relative potency factor (RPF) method to normalise the various pesticides to the index compound (IC) of methamidophos and chlorpyrifos separately. Only in the pessimistic model using methamidophos as the IC was there was small risk of exposure exceeding the ARfD (3 µg kg - 1 bw day - 1 ) in the populations of preschool children (0.029%), school-age children (0.022%) and adults (0.002%). There were no risk of exposure exceeding the ARfD of methamidophos in the optimistic model and of chlorpyrifos (100 µg kg - 1 bw day - 1 ) in both optimistic and pessimistic models in all three populations. Considering the Chinese habits of overwhelmingly eating processed food (vegetables being cooked, and fruits being washed or peeled), we conclude that little acute risk was found for the exposure to VF-sourced OPs and CPs in Shanghai.

  2. Exposure assessment of organophosphorus and organobromine flame retardants via indoor dust from elementary schools and domestic houses.

    Science.gov (United States)

    Mizouchi, Shigekazu; Ichiba, Masayoshi; Takigami, Hidetaka; Kajiwara, Natsuko; Takamuku, Toshiyuki; Miyajima, Toru; Kodama, Hiroki; Someya, Takashi; Ueno, Daisuke

    2015-03-01

    To assess the exposure of flame retardants (FRs) for school-children, organophosphorus flame retardants and plasticizers (PFRs) and organobromine flame retardants (BFRs) were determined in the indoor dust samples collected from elementary schools and domestic houses in Japan in 2009 and 2010. PFRs were detected in all the dust samples analyzed and the highest concentration of total PFRs was thousand-fold higher than that of BFRs. Among the PFRs, tris(butoxyethyl)phosphate (TBOEP) showed the highest concentration with a median (med.) of 270,000 ng g(-1) dry weight (3700-5,500,000 ng g(-1) dry weight), followed by tris(methylphenyl)phosphate (TMPPs)>triphenyl phosphate (TPHP)=tris(1,3-dichloro-2-propyl)phosphate (TDCIPP)=tris(2-chloroisopropyl)phosphate (TCIPP)=tris(2chloroethyl)phosphate (TCEP)>ethylhexyl diphenyl phosphate (EHDPP). Significantly higher concentrations of TBOEP, tri-n-butyl phosphate (TNBP), TPHP, TMPPs, and total-PFRs were found in dust samples from elementary schools than from domestic houses. It might be due to that higher concentrations of TBOEP (as leveling agent) were detected from the floor polisher/wax products collected in those elementary schools. On the other hand, significantly higher concentrations of TCEP, TCIPPs, and total chloroalkyl-PFRs were found in domestic houses than in elementary schools. Exposure assessments of PFRs via indoor dust from elementary schools and domestic houses were conducted by calculating the hazard quotient (HQ). Among PFRs, HQs for TBOEP exceeded 1 (higher than reference dose: RfD) and its highest value was 1.9. To reduce the intake of TBOEP by school-children, it is recommended that the use of floor polisher/wax containing TBOEP be reduced in schools. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Determination of organophosphorus pesticides by dispersive liquid-liquid micro extraction coupled with gas chromatography-electron capture detection

    International Nuclear Information System (INIS)

    Mohd Marsin Sanagi; Siti Umairah Mokhtar; Mazidatul Akmam Miskam; Wan Aini Wan Ibrahim

    2011-01-01

    A simple, rapid and sensitive method termed as dispersive liquid-liquid micro extraction (DLLME) combined with gas chromatography-electron capture detector (GC-ECD) was developed for the determination of selected organophosphorus pesticides (OPPs) namely chloropyrifos, dimethoate and diazinon in water sample. In this method, a mixture of carbon disulfide, CS 2 (extraction solvent) and methanol (disperser solvent) was rapidly injected using syringe into the 5.00 mL water sample to form a cloudy solution where the OPPs were extracted into the fine droplets of extraction solvent. Upon centrifugation for 3 min at 3500 rpm, the fine droplets were sedimented at the bottom of the centrifuge tube. Sedimented phase (1 μL) was injected into the GC-ECD for separation and determination of OPPs. Important extraction parameters, such as type of disperser solvent, volume of extraction solvent and volume of disperser solvent were investigated. The optimized conditions for DLLME of the selected OPPs were methanol as disperser solvent, 30 μL of extraction solvent (CS 2 ) and 1.0 mL of disperser solvent (methanol). Under the optimum extraction conditions, the method showed good linearity in the range of 0.1 to 1.0 μg/ mL with correlation coefficient (r 2 ), in the range of 0.9976 to 0.9994 and low limits of detection (LOD) between 0.047 and 0.201 μg/ mL. The proposed method provided acceptable recoveries (72.67- 144 %) with good RSDs ranging from 2.74 % to 7.48 %. This method was successfully applied to the determination of OPPs in water samples obtained from a golf course and chloropyrifos and diazinon were detected at concentration 0.18 μg/ mL and 0.07 μg/ mL, respectively. (author)

  4. Galantamine counteracts development of learning impairment in guinea pigs exposed to the organophosphorus poison soman: Clinical significance

    Science.gov (United States)

    Mamczarz, Jacek; Kulkarni, Girish S.; Pereira, Edna F. R.; Albuquerque, Edson X.

    2017-01-01

    Galantamine, a drug used to treat Alzheimer’s disease, protects guinea pigs against the acute toxicity and lethality of organophosphorus (OP) compounds, including soman. Here, we tested the hypothesis that a single exposure of guinea pigs to 1xLD50 soman triggers cognitive impairments that can be counteracted by galantamine. Thus, animals were injected intramuscularly with saline (0.5 ml/kg) or galantamine (8 mg/kg) and 30 min later injected subcutaneously with soman (26.3 µg/kg) or saline. Cognitive performance was analyzed in the Morris water maze (MWM) four days or three months after the soman challenge. Fifty percent of the saline-injected animals that were challenged with soman survived with mild-to-moderate signs of acute toxicity that subsided within a few hours. These animals showed no learning impairment and no memory retention deficit, when training in the MWM started four days post-soman challenge. In contrast, animals presented significant learning impairment when testing started three months post-challenge. Though the magnitude of the impairment correlated with the severity of the acute toxicity, animals that presented no or only mild signs of toxicity were also learning impaired. All guinea pigs that were treated with galantamine survived the soman challenge with no signs of acute toxicity and learned the MWM task as control animals, regardless of when testing began. Galantamine also prevented memory extinction in both saline-and soman-challenged animals. In conclusion, learning impairment develops months after a single exposure to 1xLD50 soman, and galantamine prevents both the acute toxicity and the delayed cognitive deficits triggered by this OP poison. PMID:21784098

  5. Selectivity improvement of positive photoionization ion mobility spectrometry for rapid detection of organophosphorus pesticides by switching dopant concentration.

    Science.gov (United States)

    Zhou, Qinghua; Li, Jia; Wang, Bin; Wang, Shuang; Li, Haiyang; Chen, Jinyuan

    2018-01-01

    Ion mobility spectrometry (IMS) opened a potential avenue for the rapid detection of organophosphorus pesticides (OPPs), though an improved selectivity of stand-alone IMS was still in high demand. In this study, a stand-alone positive photoionization ion mobility spectrometry (PP-IMS) apparatus was constructed for the rapid detection of OPPs with acetone as dopant. The photoionization of acetone molecules was induced by the ultraviolet irradiation to produce the reactant ions (Ac) 2 H + , which were employed to ionize the OPPs including fenthion, imidan, phosphamidon, dursban, dimethoate and isocarbophos via the proton transfer reaction. Due to the difference in proton affinity, the tested OPPs exhibited the different dopant-dependent manners. Based on this observation, the switching of dopant concentration was implemented to improve the selectivity of PP-IMS for OPPs detection. For instance, a mixture of fenthion, dursban and dimethoate was tested. By switching the concentration of doped acetone from 0.07 to 2.33 to 19.94mgL -1 , the ion peaks of fenthion and dursban were inhibited in succession, achieving the selective detection of dimethoate at last. In addition, another mixture of imidan and phosphamidon was initially detected by PP-IMS with a dose of 0.07mgL -1 acetone, indicating that their ion peaks were severely overlapped; when the concentration of doped acetone was switched to 19.94mgL -1 , the inhibition of imidan signals promised the accurate identification of phosphamidon in mixture. Finally, the PP-IMS in combination of switching dopant concentration was applied to detect the mixed fenthion, dursban and dimethoate in Chinese cabbage, demonstrating the applicability of proposed method to real samples. Copyright © 2017. Published by Elsevier B.V.

  6. An Innovative Rapid Method for Analysis of 10 Organophosphorus Pesticide Residues in Wheat by HS-SPME-GC-FPD/MSD.

    Science.gov (United States)

    Du, Xin; Ren, YongLin; Beckett, Stephen J

    2016-01-01

    The rapid detection of pesticide residues in wheat has become a top food security priority. A solvent-free headspace solid-phase microextraction (HS-SPME) has been evaluated for rapid screening of organophosphorus pesticide (OPP) residues in wheat with high sensitivity. Individual wheat samples (1.7 g), spiked with 10 OPPs, were placed in a 4 mL sealed amber glass vial and heated at 60°C for 45 min. During this time, the OPP residues were extracted with a 50 μm/30 μm divinylbenzene (DVB)/carboxen (CAR)/plasma desorption mass spectroscopy polydimethylsiloxane (PDMS) fiber from the headspace above the sample. The fiber was then removed and injected into the GC injection port at 250°C for desorption of the extracted chemicals. The multiple residues were identified by a GC mass spectrometer detector (GC-MSD) and quantified with a GC flame photometric detector (GC-FPD). Seven spiked levels of 10 OPPs on wheat were analyzed. The GC responses for a 50 μm/30 μm DVB/CAR/PDMS fiber increased with increasing spiking levels, yielding significant (R(2) > 0.98) linear regressions. The lowest LODs of the multiple pesticide standards were evaluated under the conditions of the validation study in a range of levels from 0 (control) to 100 ng of pesticide residue per g of wheat that separated on a low-polar GC capillary column (Agilent DB-35UI). The results of the HS-SPME method were compared with the QuEChERS AOAC 2007.01 method and they showed several advantages over the latter. These included improved sensitivity, selectivity, and simplicity.

  7. Method development and validation for the simultaneous determination of organochlorine and organophosphorus pesticides in a complex sediment matrix.

    Science.gov (United States)

    Alcántara-Concepción, Victor; Cram, Silke; Gibson, Richard; Ponce de León, Claudia; Mazari-Hiriart, Marisa

    2013-01-01

    The Xochimilco area in the southeastern part of Mexico City has a variety of socioeconomic activities, such as periurban agriculture, which is of great importance in the Mexico City metropolitan area. Pesticides are used extensively, some being legal, mostly chlorpyrifos and malathion, and some illegal, mostly DDT. Sediments are a common sink for pesticides in aquatic systems near agricultural areas, and Xochimilco sediments have a complex composition with high contents of organic matter and clay that are ideal adsorption sites for organochlorine (OC) and organophosphorus (OP) pesticides. Therefore, it is important to have a quick, affordable, and reliable method to determine these pesticides. Conventional methods for the determination of OC and OP pesticides are long, laborious, and costly owing to the high volume of solvents and adsorbents. The present study developed and validated a method for determining 18 OC and five OP pesticides in sediments with high organic and clay contents. In contrast with other methods described in the literature, this method allows isolation of the 23 pesticides with a 12 min microwave-assisted extraction (MAE) and one-step cleanup of pesticides. The method developed is a simpler, time-saving procedure that uses only 3.5 g of dry sediment. The use of MAE eliminates excessive handling and the possible loss of analytes. It was shown that the use of LC-Si cartridges with hexane-ethyl acetate (75+25, v/v) in the cleanup procedure recovered all pesticides with rates between 70 and 120%. The validation parameters demonstrated good performance of the method, with intermediate precision ranging from 7.3 to 17.0%, HorRat indexes all below 0.5, and tests of accuracy with the 23 pesticides at three concentration levels demonstrating recoveries ranging from 74 to 114% and RSDs from 3.3 to 12.7%.

  8. Planarian cholinesterase: in vitro characterization of an evolutionarily ancient enzyme to study organophosphorus pesticide toxicity and reactivation.

    Science.gov (United States)

    Hagstrom, Danielle; Hirokawa, Hideto; Zhang, Limin; Radic, Zoran; Taylor, Palmer; Collins, Eva-Maria S

    2017-08-01

    The freshwater planarian Dugesia japonica has recently emerged as an animal model for developmental neurotoxicology and found to be sensitive to organophosphorus (OP) pesticides. While previous activity staining of D. japonica, which possess a discrete cholinergic nervous system, has shown acylthiocholine catalysis, it is unknown whether this is accomplished through an acetylcholinesterase (AChE), butyrylcholinesterase (BChE), or a hybrid esterase and how OP exposure affects esterase activity. Here, we show that the majority of D. japonica cholinesterase (DjChE) activity departs from conventional AChE and BChE classifications. Inhibition by classic protonable amine and quaternary reversible inhibitors (ethopropazine, donepezil, tacrine, edrophonium, BW284c51, propidium) shows that DjChE is far less sensitive to these inhibitors than human AChE, suggesting discrete differences in active center and peripheral site recognition and structures. Additionally, we find that different OPs (chlorpyrifos oxon, paraoxon, dichlorvos, diazinon oxon, malaoxon) and carbamylating agents (carbaryl, neostigmine, physostigmine, pyridostigmine) differentially inhibit DjChE activity in vitro. DjChE was most sensitive to diazinon oxon and neostigmine and least sensitive to malaoxon and carbaryl. Diazinon oxon-inhibited DjChE could be reactivated by the quaternary oxime, pralidoxime (2-PAM), and the zwitterionic oxime, RS194B, with RS194B being significantly more potent. Sodium fluoride (NaF) reactivates OP-DjChE faster than 2-PAM. As one of the most ancient true cholinesterases, DjChE provides insight into the evolution of a hybrid enzyme before the separation into distinct AChE and BChE enzymes found in higher vertebrates. The sensitivity of DjChE to OPs and capacity for reactivation validate the use of planarians for OP toxicology studies.

  9. A sensitive LC-MS/MS method for measurement of organophosphorus pesticides and their oxygen analogs in air sampling matrices.

    Science.gov (United States)

    Armstrong, Jenna L; Dills, Russell L; Yu, Jianbo; Yost, Michael G; Fenske, Richard A

    2014-01-01

    A rapid liquid chromatography tandem mass spectrometry (LC-MS/MS) method has been developed for determination of levels of the organophosphorus (OP) pesticides chlorpyrifos (CPF), azinphos methyl (AZM), and their oxygen analogs chlorpyrifos-oxon (CPF-O) and azinphos methyl-oxon (AZM-O) on common active air sampling matrices. XAD-2 resin and polyurethane foam (PUF) matrices were extracted with acetonitrile containing stable-isotope labeled internal standards (ISTD). Analysis was accomplished in Multiple Reaction Monitoring (MRM) mode, and analytes in unknown samples were identified by retention time (±0.1 min) and qualifier ratio (±30% absolute) as compared to the mean of calibrants. For all compounds, calibration linearity correlation coefficients were ≥0.996. Limits of detection (LOD) ranged from 0.15-1.1 ng/sample for CPF, CPF-O, AZM, and AZM-O on active sampling matrices. Spiked fortification recoveries were 78-113% from XAD-2 active air sampling tubes and 71-108% from PUF active air sampling tubes. Storage stability tests also yielded recoveries ranging from 74-94% after time periods ranging from 2-10 months. The results demonstrate that LC-MS/MS is a sensitive method for determining these compounds from two different matrices at the low concentrations that can result from spray drift and long range transport in non-target areas following agricultural applications. In an inter-laboratory comparison, the limit of quantification (LOQ) for LC-MS/MS was 100 times lower than a typical gas chromatography-mass spectrometry (GC-MS) method.

  10. A Disposable Organophosphorus Pesticides Enzyme Biosensor Based on Magnetic Composite Nano-Particles Modified Screen Printed Carbon Electrode

    Directory of Open Access Journals (Sweden)

    Weigang Wen

    2010-01-01

    Full Text Available A disposable organophosphorus pesticides (OPs enzyme biosensor based on magnetic composite nanoparticle-modified screen printed carbon electrodes (SPCE has been developed. Firstly, an acetylcholinesterase (AChE-coated Fe3O4/Au (GMP magnetic nanoparticulate (GMP-AChE was synthesized. Then, GMP-AChE was absorbed on the surface of a SPCE modified by carbon nanotubes (CNTs/nano-ZrO2/prussian blue (PB/Nafion (Nf composite membrane by an external magnetic field. Thus, the biosensor (SPCE|CNTs/ZrO2/PB/Nf|GMP-AChE for OPs was fabricated. The surface of the biosensor was characterized by scanning electron micrography (SEM and X-ray fluorescence spectrometery (XRFS and its electrochemical properties were studied by cyclic voltammetry (CV and differential pulse voltammetry (DPV. The degree of inhibition (A% of the AChE by OPs was determined by measuring the reduction current of the PB generated by the AChE-catalyzed hydrolysis of acetylthiocholine (ATCh. In pH = 7.5 KNO3 solution, the A was related linearly to the concentration of dimethoate in the range from 1.0 × 10-3–10 ng•mL-1 with a detection limit of 5.6 × 10-4 ng•mL-1. The recovery rates in Chinese cabbage exhibited a range of 88%–105%. The results were consistent with the standard gas chromatography (GC method. Compared with other enzyme biosensors the proposed biosensor exhibited high sensitivity, good selectivity with disposable, low consumption of sample. In particular its surface can be easily renewed by removal of the magnet. The convenient, fast and sensitive voltammetric measurement opens new opportunities for OPs analysis.

  11. Organophosphorus pesticide and ester analysis by using comprehensive two-dimensional gas chromatography with flame photometric detection.

    Science.gov (United States)

    Liu, Xiangping; Li, Dengkun; Li, Jiequan; Rose, Gavin; Marriott, Philip J

    2013-12-15

    Thirty-seven phosphorus (P)-containing compounds comprising organophosphorus pesticides and organophosphate esters were analyzed by using comprehensive two-dimensional gas chromatography with flame photometric detection in P mode (GC × GC-FPD(P)), with a non-polar/moderately polar column set. A suitable modulation temperature and period was chosen based on experimental observation. A number of co-eluting peak pairs on the (1)D column were well separated in 2D space. Excellent FPD(P) detection selectivity, responding to compounds containing the P atom, produces clear 2D GC × GC plots with little interference from complex hydrocarbon matrices. Limits of detection (LOD) were within the range of 0.0021-0.048 μmol L(-1), and linear calibration correlation coefficients (R(2)) for all 37 P-compounds were at least 0.998. The P-compounds were spiked in 2% diesel and good reproducibility for their response areas and retention times was obtained. Spiked recoveries were 88%-157% for 5 μg L(-1) and 80%-138% for 10 μg L(-1) spiked levels. Both (1)tR and (2)tR shifts were noted when the content of diesel was in excess of 5% in the matrix. Soil samples were analyzed by using the developed method; some P-compounds were positively detected. In general, this study shows that GC × GC-FPD(P) is an accurate, sensitive and simple method for P-compound analysis in complicated environmental samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Synthesis and application of molecularly imprinted polymers for the selective extraction of organophosphorus pesticides from vegetable oils.

    Science.gov (United States)

    Boulanouar, Sara; Combès, Audrey; Mezzache, Sakina; Pichon, Valérie

    2017-09-01

    The increasing use of pesticides in agriculture causes environmental issues and possible serious health risks to humans and animals. Their determination at trace concentrations in vegetable oils constitutes a significant analytical challenge. Therefore, their analysis often requires both an extraction and a purification step prior to separation with liquid chromatography (LC) and mass spectrometry (MS) detection. This work aimed at developing sorbents that are able to selectively extract from vegetable oil samples several organophosphorus (OPs) pesticides presenting a wide range of physico-chemical properties. Therefore, different conditions were screened to prepare molecularly imprinted polymers (MIPs) by a non-covalent approach. The selectivity of the resulting polymers was evaluated by studying the OPs retention in pure media on both MIPs and non-imprinted polymers (NIP) used as control. The most promising MIP sorbent was obtained using monocrotophos (MCP) as the template, methacrylic acid (MAA) as the monomer and ethylene glycol dimethacrylate (EGDMA) as the cross-linker with a molar ratio of 1/4/20 respectively. The repeatability of the extraction procedure and of the synthesis procedure was demonstrated in pure media. The capacity of this MIP was 1mg/g for malathion. This MIP was also able to selectively extract three OPs from almond oil by applying the optimized SPE procedure. Recoveries were between 73 and 99% with SD values between 4 and 6% in this oil sample. The calculated LOQs (between 0.3 and 2μg/kg) in almond seeds with a SD between 0.1 and 0.4μg/kg were lower than the Maximum Residue Levels (MRLs) established for the corresponding compounds in almond seed. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Multiwalled carbon nanotubes as solid-phase extraction materials for the gas chromatographic determination of organophosphorus pesticides in waters.

    Science.gov (United States)

    Ravelo-Pérez, Lidia M; Hernández-Borges, Javier; Angel Rodríguez-Delgado, Miguel

    2008-10-01

    In the present work, a GC method with nitrogen-phosphorus detection (NPD) was developed for the simultaneous determination of eight organophosphorus pesticide (OPP) residues (i.e., ethoprofos, diazinon, chlorpyrifos-methyl, fenitrothion, malathion, chlorpyrifos, fenamiphos, and buprofezin) in water samples. Preconcentration of the water samples was carried out using an SPE procedure with multiwalled carbon nanotubes (MWCNTs) of 10-15 nm od, 2-6 nm id, and 0.1-10 microm length as stationary phase. Extraction parameters, such as the amount of MWCNTs, sample volume, pH, and type and amount of the eluent were optimized. The most favorable conditions were as follows: 40 mg MWCNTs, 800 mL water, pH 6.0, and 20 mL dichloromethane, respectively. The MWCNTs-SPE-GC-NPD method was applied to the determination of these pesticides in real water samples: mineral and ground water as well as run-off water from an agricultural area collected shortly before opening out onto the sea. A recovery study was developed with five consecutive extractions of the three types of water spiked at three concentration levels (n = 15). Mean recovery values were in the range of 75-116% for mineral water (RSD water (RSD waters (RSDs waters, RSDs waters). The proposed method was also applied to the analysis of six water samples (two of each type: mineral, ground, and run-off waters) in which no residues of the selected pesticides were found. Results show that the MWCNTs used in this work have a high adsorbability of the pesticides under study. The main advantage of the use of these MWCNTs is their low cost when compared with those MWCNTs previously used in the literature and with conventional SPE cartridges.

  14. Organophosphorus insecticides chlorpyrifos and diazinon and oxidative stress in neuronal cells in a genetic model of glutathione deficiency

    International Nuclear Information System (INIS)

    Giordano, Gennaro; Afsharinejad, Zhara; Guizzetti, Marina; Vitalone, Annabella; Kavanagh, Terrance J.; Costa, Lucio G.

    2007-01-01

    Over the past several years evidence has been accumulating from in vivo animal studies, observations in humans, and in vitro studies, that organophosphorus (OP) insecticides may induce oxidative stress. Such effects may contribute to some of the toxic manifestations of OPs, particularly upon chronic or developmental exposures. The aim of this study was to investigate the role of oxidative stress in the neurotoxicity of two commonly used OPs, chlorpyrifos (CPF) and diazinon (DZ), their oxygen analogs (CPO and DZO), and their 'inactive' metabolites (TCP and IMP), in neuronal cells from a genetic model of glutathione deficiency. Cerebellar granule neurons from wild type mice (Gclm +/+) and mice lacking the modifier subunit of glutamate cysteine ligase (Gclm -/-), the first and limiting step in the synthesis of glutathione (GSH), were utilized. The latter display very low levels of GSH and are more susceptible to the toxicity of agents that increase oxidative stress. CPO and DZO were the most cytotoxic compounds, followed by CPF and DZ, while TCP and IMP displayed lower toxicity. Toxicity was significantly higher (10- to 25-fold) in neurons from Gclm (-/-) mice, and was antagonized by various antioxidants. Depletion of GSH from Gclm (+/+) neurons significantly increased their sensitivity to OP toxicity. OPs increased intracellular levels of reactive oxygen species and lipid peroxidation and in both cases the effects were greater in neurons from Gclm (-/-) mice. OPs did not alter intracellular levels of GSH, but significantly increased those of oxidized glutathione (GSSG). Cytotoxicity was not antagonized by cholinergic antagonists, but was decreased by the calcium chelator BAPTA-AM. These studies indicate that cytotoxicity of OPs involves generation of reactive oxygen species and is modulated by intracellular GSH, and suggest that it may involve disturbances in intracellular homeostasis of calcium

  15. Plasma esterases in the tegu lizard Tupinambis merianae (Reptilia, Teiidae): impact of developmental stage, sex, and organophosphorus in vitro exposure.

    Science.gov (United States)

    Basso, Agustín; Attademo, Andrés M; Lajmanovich, Rafael C; Peltzer, Paola M; Junges, Celina; Cabagna, Mariana C; Fiorenza, Gabriela S; Sanchez-Hernandez, Juan Carlos

    2012-01-01

    In this study, we determined normal serum butyrylcholinesterase (BChE) and carboxylesterase (CbE) activities in Tupinambis merianae in order to obtain reference values for organophosphorus pesticide monitoring. Forty-two T. merianae individuals were grouped by sex and size to identify potential differences in their enzyme levels to allow for proper representation of normal values for females, males, juveniles, and hatchlings. Mean CbE was determined using two model substrates: alpha-naphtylacetate (α-NA) and p-nitrophenyl valerate (4-NPV). BChE and CbE sensitivity to malaoxon (Mx) was also evaluated as well as the possibility of BChE reactivation with pyridine-2-aldoxime methochloride (2-PAM). Mean adult females' BChE was significantly higher than adult males, juveniles, and hatchlings. No significant differences were found between groups regarding CbE. CbE (4-NPV) activity showed slightly negative correlation with lizard snout-vent length, while BChE and CbE (α-NA) showed no correlation with body size. Apparent IC(50) values for BChE and CbE (α-NA) suggested different sensitivities among groups. CbE (4-NPV) could not be inhibited. All Mx-inhibited groups treated with 2-PAM in a final concentration of 2.8 mM showed clear signs of reactivation. In conclusion, the results demonstrate that (1) plasma esterase activity did not vary with age and sex, except for BChE activity, and (2) because biological and environmental variables could be confounding factors in the response of plasma cholinesterases, complementary biomarkers like CbE inhibition and oxime-induced reactivation of esterases are strongly recommended.

  16. Organophosphorus pesticide residues in vegetables from farms, markets, and a supermarket around Kwan Phayao Lake of Northern Thailand.

    Science.gov (United States)

    Sapbamrer, Ratana; Hongsibsong, Surat

    2014-07-01

    This study investigated organophosphorus (OP) residues in vegetables from 27 farms, 106 markets, and 1 supermarket around Kwan Phayao Lake, Northern Thailand, between August and September 2013. Types of vegetables sampled were all vegetables cultivated or sold around the study site. The most common OP pesticides detected in farm samples were chlorpyrifos (50 %), malathion (31.8 %), monocrotophos (31.8 %), diazinon (13.6 %), omethoate (13.6 %), and dicrotophos (9.1 %). The most common OP pesticides detected in market samples were chlorpyrifos (33.9 %), diazinon (18.6 %), parathion-methyl (3.4 %), profenofos (3.4 %), primiphos-ethyl (3.4 %), and fenitrothion (1.7 %). The OP pesticides detected in supermarket samples were chlorpyrifos (33.3 %), and diazinon (66.7 %). Among the compounds detected, chlorpyrifos was detected in most of the vegetable samples from all sources. The highest chlorpyrifos level in farm samples were found in lemon balm (2.423 mg/kg) followed by Vietnamese coriander (0.835 mg/kg), and cowpea (0.027 mg/kg). The highest level in markets samples were found in garlic (7.785 mg/kg) followed by Chinese cabbage (2.864 mg/kg) and Vietnamese coriander (1.308 mg/kg). Residues from supermarket samples were found only in parsley (0.027 mg/kg). The findings showed that 16 samples (59.3 %) from farms and 14 samples (13.2 %) from markets contained OP residues at or above the maximum residue limits established by the European Union. It is concluded that awareness, safety education, and strict regulation of pesticide use are necessary.

  17. Proton conducting membranes prepared by incorporation of organophosphorus acids into alcohol barrier polymers for direct methanol fuel cells

    Science.gov (United States)

    Jiang, Zhongyi; Zheng, Xiaohong; Wu, Hong; Pan, Fusheng

    A novel type of DMFC membrane was developed via incorporation of organophosphorus acids (OPAs) into alcohol barrier materials (polyvinyl alcohol/chitosan, PVA/CS) to simultaneously acquire high proton conductivity and low methanol permeability. Three kinds of OPAs including amino trimethylene phosphonic acid (ATMP), ethylene diamine tetra(methylene phosphonic acid) (EDTMP) and hexamethylene diamine tetra(methylene phosphonic acid) (HDTMP), with different molecular structure and phosphonic acid groups content were added into PVA/CS blends and served the dual functions as proton conductor as well as crosslinker. The as-prepared OPA-doped PVA/CS membranes exhibited remarkably enhanced proton conducting ability, 2-4 times higher than that of the pristine PVA/CS membrane, comparable with that for Nafion ®117 membrane (5.04 × 10 -2 S cm -1). The highest proton conductivities 3.58 × 10 -2, 3.51 × 10 -2 and 2.61 × 10 -2 S cm -1 for ATMP-, EDTMP- and HDTMP-doped membranes, respectively were all achieved at highest initial OPA doping content (23.1 wt.%) at room temperature. The EDTMP-doped PVA/CS membrane with an acid content of 13.9 wt.% showed the lowest methanol permeability of 2.32 × 10 -7 cm 2 s -1 which was 16 times lower than that of Nafion ®117 membrane. In addition, the thermal stability and oxidative durability were both significantly improved by the incorporation of OPAs in comparison with pristine PVA/CS membranes.

  18. Proton conducting membranes prepared by incorporation of organophosphorus acids into alcohol barrier polymers for direct methanol fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Zhongyi; Zheng, Xiaohong; Wu, Hong; Pan, Fusheng [Key Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)

    2008-10-15

    A novel type of DMFC membrane was developed via incorporation of organophosphorus acids (OPAs) into alcohol barrier materials (polyvinyl alcohol/chitosan, PVA/CS) to simultaneously acquire high proton conductivity and low methanol permeability. Three kinds of OPAs including amino trimethylene phosphonic acid (ATMP), ethylene diamine tetra(methylene phosphonic acid) (EDTMP) and hexamethylene diamine tetra(methylene phosphonic acid) (HDTMP), with different molecular structure and phosphonic acid groups content were added into PVA/CS blends and served the dual functions as proton conductor as well as crosslinker. The as-prepared OPA-doped PVA/CS membranes exhibited remarkably enhanced proton conducting ability, 2-4 times higher than that of the pristine PVA/CS membrane, comparable with that for Nafion {sup registered} 117 membrane (5.04 x 10{sup -2} S cm{sup -1}). The highest proton conductivities 3.58 x 10{sup -2}, 3.51 x 10{sup -2} and 2.61 x 10{sup -2} S cm{sup -1} for ATMP-, EDTMP- and HDTMP-doped membranes, respectively were all achieved at highest initial OPA doping content (23.1 wt.%) at room temperature. The EDTMP-doped PVA/CS membrane with an acid content of 13.9 wt.% showed the lowest methanol permeability of 2.32 x 10{sup -7} cm{sup 2} s{sup -1} which was 16 times lower than that of Nafion {sup registered} 117 membrane. In addition, the thermal stability and oxidative durability were both significantly improved by the incorporation of OPAs in comparison with pristine PVA/CS membranes. (author)

  19. Resistance to organophosphorus agent toxicity in transgenic mice expressing the G117H mutant of human butyrylcholinesterase

    International Nuclear Information System (INIS)

    Wang Yuxia; Ticu Boeck, Andreea; Duysen, Ellen G.; Van Keuren, Margaret; Saunders, Thomas L.; Lockridge, Oksana

    2004-01-01

    Organophosphorus toxicants (OP) include chemical nerve agents and pesticides. The goal of this work was to find out whether an animal could be made resistant to OP toxicity by genetic engineering. The human butyrylcholinesterase (BChE) mutant G117H was chosen for study because it has the unusual ability to hydrolyze OP as well as acetylcholine, and it is resistant to inhibition by OP. Human G117H BChE, under the control of the ROSA26 promoter, was expressed in all tissues of transgenic mice. A stable transgenic mouse line expressed 0.5 μg/ml of human G117H BChE in plasma as well as 2 μg/ml of wild-type mouse BChE. Intestine, kidneys, stomach, lungs, heart, spleen, liver, brain, and muscle expressed 0.6-0.15 μg/g of G117H BChE. Transgenic mice were normal in behavior and fertility. The LD50 dose of echothiophate for wild-type mice was 0.1 mg/kg sc. This dose caused severe cholinergic signs of toxicity and lethality in wild-type mice, but caused no deaths and only mild toxicity in transgenic animals. The mechanism of protection was investigated by measuring acetylcholinesterase (AChE) and BChE activity. It was found that AChE and endogenous BChE were inhibited to the same extent in echothiophate-treated wild type and transgenic mice. This led to the hypothesis that protection against echothiophate toxicity was not explained by hydrolysis of echothiophate. In conclusion, the transgenic G117H BChE mouse demonstrates the factors required to achieve protection from OP toxicity in a vertebrate animal

  20. Polyacrylic acid-coated cerium oxide nanoparticles: An oxidase mimic applied for colorimetric assay to organophosphorus pesticides.

    Science.gov (United States)

    Zhang, Shi-Xiang; Xue, Shi-Fan; Deng, Jingjing; Zhang, Min; Shi, Guoyue; Zhou, Tianshu

    2016-11-15

    It is important and urgent to develop reliable and highly sensitive methods that can provide on-site and rapid detection of extensively used organophosphorus pesticides (OPs) for their neurotoxicity. In this study, we developed a novel colorimetric assay for the detection of OPs based on polyacrylic acid-coated cerium oxide nanoparticles (PAA-CeO2) as an oxidase mimic and OPs as inhibitors to suppress the activity of acetylcholinesterase (AChE). Firstly, highly dispersed PAA-CeO2 was prepared in aqueous solution, which could catalyze the oxidation of TMB to produce a color reaction from colorless to blue. And the enzyme of AChE was used to catalyze the substrate of acetylthiocholine (ATCh) to produce thiocholine (TCh). As a thiol-containing compound with reducibility, TCh can decrease the oxidation of TMB catalyzed by PAA-CeO2. Upon incubated with OPs, the enzymatic activity of AChE was inhibited to produce less TCh, resulting in more TMB catalytically oxidized by PAA-CeO2 to show an increasing blue color. The two representative OPs, dichlorvos and methyl-paraoxon, were tested using our proposed assay. The novel assay showed notable color change in a concentration-dependent manner, and as low as 8.62 ppb dichlorvos and 26.73 ppb methyl-paraoxon can be readily detected. Therefore, taking advantage of such oxidase-like activity of PAA-CeO2, our proposed colorimetric assay can potentially be a screening tool for the precise and rapid evaluation of the neurotoxicity of a wealth of OPs. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Biodegradation and bioremediation potential of diazinon-degrading Serratia marcescens to remove other organophosphorus pesticides from soils.

    Science.gov (United States)

    Cycoń, Mariusz; Żmijowska, Agnieszka; Wójcik, Marcin; Piotrowska-Seget, Zofia

    2013-03-15

    The ability of diazinon-degrading Serratia marcescens to remove organophosphorus pesticides (OPPs), i.e. chlorpyrifos (CP), fenitrothion (FT), and parathion (PT) was studied in a mineral salt medium (MSM) and in three soils of different characteristics. This strain was capable of using all insecticides at concentration of 50 mg/l as the only carbon source when grown in MSM, and 58.9%, 70.5%, and 82.5% of the initial dosage of CP, FT, and PT, respectively was degraded within 14 days. The biodegradation experiment showed that autochthonous microflora in all soils was characterized by a degradation potential of all tested OPPs; however, the initial lag phases for degradation of CP and FT, especially in sandy soil, were observed. During the 42-day experiment, 45.3%, 61.4% and 72.5% of the initial dose of CP, FT, and PT, respectively, was removed in sandy soil whereas the degradation of CP, FT, and PT in the same period, in sandy loam and silty soils reached 61.4%, 79.7% and 64.2%, and 68.9%, 81.0% and 63.6%, respectively. S. marcescens introduced into sterile soils showed a higher degradation potential (5-13%) for OPPs removal than those observed in non-sterile soil with naturally occurring attenuation. Inoculation of non-sterile soils with S. marcescens enhanced the disappearance rates of all insecticides, and DT50 for CP, FT, and PT was reduced by 20.7, 11.3 and 13.0 days, and 11.9, 7.0 and 8.1 days, and 9.7, 14.5 and 12.6 days in sandy, sandy loam, and silty soils, respectively, in comparison with non-sterile soils with only indigenous microflora. This ability of S. marcescens makes it a suitable strain for bioremediation of soils contaminated with OPPs. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Lysophosphatidylcholine hydrolases of human erythrocytes, lymphocytes, and brain: Sensitive targets of conserved specificity for organophosphorus delayed neurotoxicants

    International Nuclear Information System (INIS)

    Vose, Sarah C.; Holland, Nina T.; Eskenazi, Brenda; Casida, John E.

    2007-01-01

    Brain neuropathy target esterase (NTE), associated with organophosphorus (OP)-induced delayed neuropathy, has the same OP inhibitor sensitivity and specificity profiles assayed in the classical way (paraoxon-resistant, mipafox-sensitive hydrolysis of phenyl valerate) or with lysophosphatidylcholine (LysoPC) as the substrate. Extending our earlier observation with mice, we now examine human erythrocyte, lymphocyte, and brain LysoPC hydrolases as possible sensitive targets for OP delayed neurotoxicants and insecticides. Inhibitor profiling of human erythrocytes and lymphocytes gave the surprising result of essentially the same pattern as with brain. Human erythrocyte LysoPC hydrolases are highly sensitive to OP delayed neurotoxicants, with in vitro IC 50 values of 0.13-85 nM for longer alkyl analogs, and poorly sensitive to the current OP insecticides. In agricultural workers, erythrocyte LysoPC hydrolyzing activities are similar for newborn children and their mothers and do not vary with paraoxonase status but have high intersample variation that limits their use as a biomarker. Mouse erythrocyte LysoPC hydrolase activity is also of low sensitivity in vitro and in vivo to the OP insecticides whereas the delayed neurotoxicant ethyl n-octylphosphonyl fluoride inhibits activity in vivo at 1-3 mg/kg. Overall, inhibition of blood LysoPC hydrolases is as good as inhibition of brain NTE as a predictor of OP inducers of delayed neuropathy. NTE and lysophospholipases (LysoPLAs) both hydrolyze LysoPC, yet they are in distinct enzyme families with no sequence homology and very different catalytic sites. The relative contributions of NTE and LysoPLAs to LysoPC hydrolysis and clearance from erythrocytes, lymphocytes, and brain remain to be defined

  3. Integrated Lateral Flow Test Strip with Electrochemical Sensor for Quantification of Phosphorylated Cholinesterase: Biomarker of Exposure to Organophosphorus Agents

    Energy Technology Data Exchange (ETDEWEB)

    Du, Dan; Wang, Jun; Wang, Limin; Lu, Donglai; Lin, Yuehe

    2012-02-08

    An integrated lateral flow test strip with electrochemical sensor (LFTSES) device with rapid, selective and sensitive response for quantification of exposure to organophosphorus (OP) pesticides and nerve agents has been developed. The principle of this approach is based on parallel measurements of post-exposure and baseline acetylcholinesterase (AChE) enzyme activity, where reactivation of the phosphorylated AChE is exploited to enable measurement of total amount of AChE (including inhibited and active) which is used as a baseline for calculation of AChE inhibition. Quantitative measurement of phosphorylated adduct (OP-AChE) was realized by subtracting the active AChE from the total amount of AChE. The proposed LFTSES device integrates immunochromatographic test strip technology with electrochemical measurement using a disposable screen printed electrode which is located under the test zone. It shows linear response between AChE enzyme activity and enzyme concentration from 0.05 to 10 nM, with detection limit of 0.02 nM. Based on this reactivation approach, the LFTSES device has been successfully applied for in vitro red blood cells inhibition studies using chlorpyrifos oxon as a model OP agent. This approach not only eliminates the difficulty in screening of low-dose OP exposure because of individual variation of normal AChE values, but also avoids the problem in overlapping substrate specificity with cholinesterases and avoids potential interference from other electroactive species in biological samples. It is baseline free and thus provides a rapid, sensitive, selective and inexpensive tool for in-field and point-of-care assessment of exposures to OP pesticides and nerve agents.

  4. An Age-Dependent Physiologically-Based Pharmacokinetic/Pharmacodynamic Model for the Organophosphorus Insecticide Chlorpyrifos in the Preweanling Rat

    Energy Technology Data Exchange (ETDEWEB)

    Timchalk, Chuck; Kousba, Ahmed A.; Poet, Torka S.

    2007-08-01

    Juvenile rats are more susceptible than adults to the acute toxicity of organophosphorus insecticides like chlorpyrifos (CPF). Age- and dose-dependent differences in metabolism may be responsible. Of importance is CYP450 activation and detoxification of CPF to chlorpyrifos-oxon (CPF-oxon) and trichloropyridinol (TCP), as well as B-esterase (cholinesterase; ChE) and A-esterase (PON-1) detoxification of CPF-oxon to TCP. In the current study, a modified physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) model incorporating age-dependent changes in CYP450, PON-1, and tissue ChE levels for rats was developed. In this model, age was used as a dependent function to estimate body weight which was then used to allometrically scale both metabolism and tissue ChE levels. Model simulations suggest that preweanling rats are particularly sensitive to CPF toxicity, with levels of CPF-oxon in blood and brain disproportionately increasing, relative to the response in adult rats. This age-dependent non-linear increase in CPF-oxon concentration may potentially result from the depletion of non-target B-esterases, and a lower PON-1 metabolic capacity in younger animals. These results indicate that the PBPK/PD model behaves consistently with the general understanding of CPF toxicity, pharmacokinetics and tissue ChE inhibition in neonatal and adult rats. Hence, this model represents an important starting point for developing a computational model to assess the neurotoxic potential of environmentally relevant organophosphate exposures in infants and children.

  5. Consumption of fruits and vegetables and probabilistic assessment of the cumulative acute exposure to organophosphorus and carbamate pesticides of schoolchildren in Slovenia.

    Science.gov (United States)

    Blaznik, Urška; Yngve, Agneta; Eržen, Ivan; Hlastan Ribič, Cirila

    2016-02-01

    Adequate consumption of fruits and vegetables is a part of recommendations for a healthy diet. The aim of the present study was to assess acute cumulative dietary exposure to organophosphorus and carbamate pesticides via fruit and vegetable consumption by the population of schoolchildren aged 11-12 years and the level of risk for their health. Cumulative probabilistic risk assessment methodology with the index compound approach was applied. Slovenia, primary schools. Schoolchildren (n 1145) from thirty-one primary schools in Slovenia. Children were part of the PRO GREENS study 2009/10 which assessed 11-year-olds' consumption of fruit and vegetables in ten European countries. The cumulative acute exposure amounted to 8.3 (95% CI 7.7, 10.6) % of the acute reference dose (ARfD) for acephate as index compound (100 µg/kg body weight per d) at the 99.9th percentile for daily intake and to 4.5 (95% CI 3.5, 4.7) % of the ARfD at the 99.9th percentile for intakes during school time and at lunch. Apples, bananas, oranges and lettuce contributed most to the total acute pesticides intake. The estimations showed that acute dietary exposure to organophosphorus and carbamate pesticides is not a health concern for schoolchildren with the assessed dietary patterns of fruit and vegetable consumption.

  6. Isolation of the opdE gene that encodes for a new hydrolase of Enterobacter sp. capable of degrading organophosphorus pesticides.

    Science.gov (United States)

    Chino-Flores, Concepción; Dantán-González, Edgar; Vázquez-Ramos, Alejandra; Tinoco-Valencia, Raunel; Díaz-Méndez, Rafael; Sánchez-Salinas, Enrique; Castrejón-Godínez, Maria Luisa; Ramos-Quintana, Fernando; Ortiz-Hernández, Maria Laura

    2012-06-01

    Microbial enzymes that can hydrolyze organophosphorus compounds have been isolated, identified and characterized from different microbial species in order to use them in biodegradation of organophosphorus compounds. We isolated a bacterial strain Cons002 from an agricultural soil bacterial consortium, which can hydrolyze methyl-parathion (MP) and other organophosphate pesticides. HPLC analysis showed that strain Cons002 is capable of degrading pesticides MP, parathion and phorate. Pulsed-field gel electrophoresis and 16S rRNA amplification were performed for strain characterization and identification, respectively, showing that the strain Cons002 is related to the genus Enterobacter sp. which has a single chromosome of 4.6 Mb and has no plasmids. Genomic library was constructed from DNA of Enterobacter sp. Cons002. A gene called opdE (Organophosphate Degradation from Enterobacter) consists of 753 bp and encodes a protein of 25 kDa, which was isolated using activity methods. This gene opdE had no similarity to any genes reported to degrade organophosphates. When kanamycin-resistance cassette was placed in the gene opdE, hydrolase activity was suppressed and Enterobacter sp. Cons002 had no growth with MP as a nutrients source.

  7. Simultaneous determination of organophosphorus pesticides in fruits and vegetables using atmospheric pressure gas chromatography quadrupole-time-of-flight mass spectrometry.

    Science.gov (United States)

    Cheng, Zhipeng; Dong, Fengshou; Xu, Jun; Liu, Xingang; Wu, Xiaohu; Chen, Zenglong; Pan, Xinglu; Gan, Jay; Zheng, Yongquan

    2017-09-15

    This paper describes the application of atmospheric pressure gas chromatography quadrupole-time-of-flight mass spectrometry for the simultaneous determination of organophosphorus pesticides in apple, pear, tomato, cucumber and cabbage. Soft ionization with atmospheric pressure ionization source was compared with traditional electron impact ionization (EI). The sensitivity of GC coupled to atmospheric pressure ionization (APGC) for all the analytes was enhanced by 1.0-8.2 times. The ionization modes with atmospheric pressure ionization source was studied by comparing the charge-transfer and proton-transfer conditions. The optimized QuEChERs method was used to pretreat the samples. The calibration curves were found linear from 10 to 1000μg/L, obtaining correlation coefficients higher than 0.9845. Satisfactory mean recovery values, in the range of 70.0-115.9%, and satisfactory precision, with all RSD r <19.7% and all RSD R values <19.5% at the three fortified concentration levels for all the fifteen OPPs. The results demonstrate the potential of APGC-QTOF-MS for routine quantitative analysis of organophosphorus pesticide in fruits and vegetables. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. [High throuput analysis of organophosphorus pesticide residues and their metabolites in animal original foods by dual gas chromatography-dual pulse flame photometric detection].

    Science.gov (United States)

    Yang, Lixin; Li, Heli; Miao, Hong; Zeng, Fangang; Li, Ruifeng; Chen, Huijing; Zhao, Yunfeng; Wu, Yongning

    2011-10-01

    A method was established for the quantitative determination of 54 organophosphorus pesticide residues and their metabolites in foods of animal origin by dual gas chromatography-dual pulse flame photometric detection. Homogenized samples were extracted with acetone and methylene chloride, and cleaned-up by gel permeation chromatography (GPC). The response of each analyte showed a good linearity with a correlation coefficient not less than 0. 99. The recovery experiments were performed by a blank sample spiked at low, medium and high fortification levels. The recoveries for beef, mutton, pork, chicken were in the range of 50. 5% -128. 1% with the relative standard deviations (n = 6) of 1. 1% -25. 5%, which demonstrated the good precision and accuracy of the present method. The limits of detection for the analytes were in the range of 0. 001 -0. 170 mg/kg, and the limits of quantification were in the range of 0. 002 -0. 455 mg/kg. Animal food samples collected from markets such as meat, liver and kidney were analyzed, and the residues of dichlorovos and disulfoton-sulfoxide were found in the some samples. The established method is sensitive and selective enough to detect organophosphorus pesticide residues in animal foods.

  9. Developmental exposure to terbutaline alters cell signaling in mature rat brain regions and augments the effects of subsequent neonatal exposure to the organophosphorus insecticide chlorpyrifos

    International Nuclear Information System (INIS)

    Meyer, Armando; Seidler, Frederic J.; Aldridge, Justin E.; Slotkin, Theodore A.

    2005-01-01

    Exposure to apparently unrelated neurotoxicants can nevertheless converge on common neurodevelopmental events. We examined the long-term effects of developmental exposure of rats to terbutaline, a β-adrenoceptor agonist used to arrest preterm labor, and the organophosphorus insecticide chlorpyrifos (CPF) separately and together. Treatments mimicked the appropriate neurodevelopmental stages for human exposures: terbutaline on postnatal days (PN) 2-5 and CPF on PN11-14, with assessments conducted on PN45. Although neither treatment affected growth or viability, each elicited alterations in CNS cell signaling mediated by adenylyl cyclase (AC), a transduction pathway shared by numerous neuronal and hormonal signals. Terbutaline altered signaling in the brainstem and cerebellum, with gender differences particularly notable in the cerebellum (enhanced AC in males, suppressed in females). By itself, CPF exposure elicited deficits in AC signaling in the midbrain, brainstem, and striatum. However, sequential exposure to terbutaline followed by CPF produced larger alterations and involved a wider spectrum of brain regions than were obtained with either agent alone. In the cerebral cortex, adverse effects of the combined treatment intensified between PN45 and PN60, suggesting that exposures alter the long-term program for development of synaptic communication, leading to alterations in AC signaling that emerge even after adolescence. These findings indicate that terbutaline, like CPF, is a developmental neurotoxicant, and reinforce the idea that its use in preterm labor may create a subpopulation that is sensitized to long-term CNS effects of organophosphorus insecticides

  10. Serbia's Military Neutrality: Origins, effects and challenges

    Directory of Open Access Journals (Sweden)

    Ejdus Filip

    2014-10-01

    Full Text Available Serbia is the only state in the Western Balkans that is not seeking NATO membership. In December 2007, Serbia declared military neutrality and in spite of its EU membership aspirations, developed very close relations with Moscow. The objective of this paper is threefold. First, I argue that in order to understand why Serbia declared military neutrality, one has to look both at the discursive terrain and domestic power struggles. The key narrative that was strategically used by mnemonic entrepreneurs, most importantly by the former Prime Minister Vojislav Koštunica, to legitimize military neutrality was the trauma of NATO intervention in 1999 and the ensuing secession of Kosovo. In the second part of the paper, I discuss the operational consequences of the military neutrality policy for Serbia's relations with NATO and Russia, as well as for military reform and EU accession. Finally, I spell out the challenges ahead in Serbia's neutrality policy and argue that its decision makers will increasingly be caught between pragmatic foreign policy requirements on the one hand and deeply entrenched traumatic memories on the other.

  11. Kinetic Properties of the Neutral Solar Wind

    International Nuclear Information System (INIS)

    Florinski, V.; Heerikhuisen, J.

    2017-01-01

    Charge-exchange collisions between the solar wind protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the solar-wind speed. This tenuous population, known as the neutral solar wind (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.

  12. Kinetic Properties of the Neutral Solar Wind

    Science.gov (United States)

    Florinski, V.; Heerikhuisen, J.

    2017-03-01

    Charge-exchange collisions between the solar wind protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the solar-wind speed. This tenuous population, known as the neutral solar wind (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.

  13. Neutral axis as damage sensitive feature

    International Nuclear Information System (INIS)

    Sigurdardottir, D H; Glisic, B

    2013-01-01

    Structural health monitoring (SHM) is the process of continuously or periodically measuring structural parameters and the transformation of the collected data into information on real structural conditions. The centroid of stiffness is a universal parameter and its position in a cross-section can be evaluated for any load-carrying beam structure as the position of the neutral axis under conveniently chosen loads. Thus, a change in the position of the neutral axis within a cross-section can indicate a change in the position of the centroid of stiffness, i.e., unusual structural behaviors. This paper proposes a novel monitoring method based on deterministic and probabilistic determination of the position of the neutral axis under conveniently chosen conditions. Therefore, the method proposed in this paper is potentially applicable to a large variety of beam-like structures. Data from two existing structures were used to validate the method and assess its performance: Streicker Bridge at Princeton University and the US202/NJ23 highway overpass in Wayne, NJ. The results show that the neutral axis location is varying even when damage is not present. Reasons for this variation are determined and the accuracy in the evaluation assessed. This paper concludes that the position of the neutral axis can be evaluated with sufficient accuracy using static and dynamic strain measurements performed on appropriate time-scales and indicates its potential to be used as a damage sensitive feature. (paper)

  14. Neutral axis as damage sensitive feature

    Science.gov (United States)

    Sigurdardottir, D. H.; Glisic, B.

    2013-07-01

    Structural health monitoring (SHM) is the process of continuously or periodically measuring structural parameters and the transformation of the collected data into information on real structural conditions. The centroid of stiffness is a universal parameter and its position in a cross-section can be evaluated for any load-carrying beam structure as the position of the neutral axis under conveniently chosen loads. Thus, a change in the position of the neutral axis within a cross-section can indicate a change in the position of the centroid of stiffness, i.e., unusual structural behaviors. This paper proposes a novel monitoring method based on deterministic and probabilistic determination of the position of the neutral axis under conveniently chosen conditions. Therefore, the method proposed in this paper is potentially applicable to a large variety of beam-like structures. Data from two existing structures were used to validate the method and assess its performance: Streicker Bridge at Princeton University and the US202/NJ23 highway overpass in Wayne, NJ. The results show that the neutral axis location is varying even when damage is not present. Reasons for this variation are determined and the accuracy in the evaluation assessed. This paper concludes that the position of the neutral axis can be evaluated with sufficient accuracy using static and dynamic strain measurements performed on appropriate time-scales and indicates its potential to be used as a damage sensitive feature.

  15. A Measurement of Coherent Neutral Pion Production in Neutrino Neutral Current Interactions in NOMAD experiment

    CERN Document Server

    Kullenberg, C T

    2009-01-01

    We present a study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to $1.44 \\times 10^6$ muon-neutrino Charged Current interactions in the energy range $2.5 \\leq E_{\

  16. The control of powerful neutral beams

    International Nuclear Information System (INIS)

    Theil, E.; Jacobson, V.

    1986-01-01

    While significant progress has been made in the development of neutral beams for the heating and sustaining of plasmas in large fusion experiments, the control of such devices has largely been a matter of hardware interlocks and operator experience. The need for computer-assisted control becomes more evident, however, with the initiation of multi-beamline experiments. This paper describes a software system that incorporates simple mathematical models coupled to Kalman filters for control of the high power (6 to 8 MW) beams currently under development at Lawrence Berkeley Laboratory's Neutral Beam Engineering Test Facility. Among the principal features of the system are: reduction of a large number of operator variables to just a few (usually one or two); the ability to describe most of the major neutral beams in use and under development; a foundation resting on statistical data analysis and control system principles rather than rules-of-thumb

  17. Neutralization kinetics of charged polymer surface

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Mukherjee, M. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: manabendra.mukherjee@saha.ac.in

    2008-04-15

    In case of photoemission spectroscopy of an insulating material the data obtained from the charged surface are normally distorted due to differential charging. Recently, we have developed a controlled surface neutralization technique to study the kinetics of the surface charging. Using this technique and the associated data analysis scheme with an effective charging model, quantitative information from the apparently distorted photoemission data from PTFE surfaces were extracted. The surface charging was controlled by tuning the electron flood current as well as the X-ray intensity. The effective model was found to describe the charging consistently for both the cases. It was shown that the non-linear neutralization response of differential charging around a critical neutralizing electron flux or a critical X-ray emission current was due to percolation of equipotential surface domains. The obtained value of the critical percolation exponent {gamma} close to unity indicates a percolation similar to that of avalanche breakdown or chain reaction.

  18. The Framing of Network Neutrality Governance

    DEFF Research Database (Denmark)

    Perry, James

    The neutrality of the internet with regard to applications (e.g. search, social networking, email, to mention only three) has been central to innovation and growth in the knowledge-economy over the past two decades. Until recently, neutrality was built into the internet's design via its core stan...... with a critical analysis of their respective operational paradigms, the paper seeks to understand who is framing the debate, how they are doing so, and to what (systemic) effect....... generative: Useful innovations in applications of the internet could take hold easily, and it was difficult – or indeed impossible - for incumbent business interests to disrupt or sabotage them. However, this neutrality is now under threat. New technologies have given incumbent businesses the ability...

  19. Current neutralization of converging ion beams

    International Nuclear Information System (INIS)

    Mosher, D.

    1978-01-01

    It is desired to consider the problem of current neutralization of heavy ion beams traversing gas backgrounds in which the conductivity changes due to beam heating and beam convergence. The procedure is to determine Green's-function solutions to the magnetic-diffusion equation derived from Maxwell's equations and an assumed scaler-plasma conductivity sigma for the background-electron current density j/sub e/. The present calculation is more general than some previously carried out in that arbitrary time variations for the beam current j/sub b/ and conductivity are allowed and the calculation is valid for both weak and strong neutralization. Results presented here must be combined with an appropriate energy-balance equation for the heated background in order to obtain the neutralization self-consistently

  20. Optimal neutral beam heating scenario for FED

    International Nuclear Information System (INIS)

    Hively, L.M.; Houlberg, W.A.; Attenberger, S.E.

    1981-01-01

    Optimal neutral beam heating scenarios are determined for FED based on a 1/one-half/-D transport analysis. Tradeoffs are examined between neutral beam energy, power, and species mix for positive ion systems. A ramped density startup is found to provide the most economical heating. The resulting plasma power requirements are reduced by 10-30% from a constant density startup. For beam energies between 100 and 200 keV, the power needed to heat the plasma does not decrease significantly as beam energy is increased. This is due to reduced ion heating, more power in the fractional energy components, and rising power supply requirements as beam energy increases

  1. Inducing Risk Neutral Preferences with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2013-01-01

    validity of any strategic equilibrium behavior, or even the customary independence axiom. We show that subjects sampled from our population are generally risk averse when lotteries are defined over monetary outcomes, and that the binary lottery procedure does indeed induce a statistically significant shift......We evaluate the binary lottery procedure for inducing risk neutral behavior. We strip the experimental implementation down to bare bones, taking care to avoid any potentially confounding assumptions about behavior having to be made. In particular, our evaluation does not rely on the assumed...... toward risk neutrality. This striking result generalizes to the case in which subjects make several lottery choices and one is selected for payment....

  2. Beam divergence scaling in neutral beam injectors

    International Nuclear Information System (INIS)

    Holmes, A.J.T.

    1976-01-01

    One of the main considerations in the design of neutral beam injectors is to monimize the divergence of the primary ion beam and hence maximize the beam transport and minimize the input of thermal gas. Experimental measurements of the divergence of a cylindrical ion beam are presented and these measurements are used to analyze the major components of ion beam divergence, namely: space charge expansion, gas-ion scattering, emittance and optical aberrations. The implication of these divergence components in the design of a neutral beam injector system is discussed and a method of maximizing the beam current is described for a given area of source plasma

  3. Simplified Stability Criteria for Delayed Neutral Systems

    Directory of Open Access Journals (Sweden)

    Xinghua Zhang

    2014-01-01

    Full Text Available For a class of linear time-invariant neutral systems with neutral and discrete constant delays, several existing asymptotic stability criteria in the form of linear matrix inequalities (LMIs are simplified by using matrix analysis techniques. Compared with the original stability criteria, the simplified ones include fewer LMI variables, which can obviously reduce computational complexity. Simultaneously, it is theoretically shown that the simplified stability criteria and original ones are equivalent; that is, they have the same conservativeness. Finally, a numerical example is employed to verify the theoretic results investigated in this paper.

  4. Neutral Naturalness from Orbifold Higgs Models

    Science.gov (United States)

    Craig, Nathaniel; Knapen, Simon; Longhi, Pietro

    2015-02-01

    We present a general class of natural theories in which the Higgs boson is a pseudo-Goldstone boson in an orbifolded gauge theory. The symmetry protecting the Higgs boson at low energies is an accidental global symmetry of the quadratic action, rather than a full continuous symmetry. The lightest degrees of freedom protecting the weak scale carry no standard model (SM) quantum numbers and interact with visible matter principally through the Higgs portal. This opens the door to the systematic study of "neutral naturalness": natural theories with SM-neutral states that are as yet untested by the LHC.

  5. Greenhouse gas neutral Germany in 2050

    International Nuclear Information System (INIS)

    Benndorf, Rosemarie; Bernicke, Maja; Bertram, Andreas

    2014-01-01

    In order to answer the question how a greenhouse gas neutral Germany would look like an interdisciplinary process was started by the Federal Environmental Agency. It was clear from the beginning of this work that a sustainable regenerative energy supply could not be sufficient. Therefore all relevant emission sources were included into the studies: traffic, industry, waste and waste water, agriculture, land usage, land usage changes and forestry. The necessary transformation paths to reach the aim of a greenhouse gas neutral Germany in 2050, economic considerations and political instruments were not part of this study.

  6. PDX neutral-beam reionization losses

    International Nuclear Information System (INIS)

    Kugel, H.W.; Dylla, H.F.; Eubank, H.P.; Kozub, T.A.; Moore, R.; Schilling, G.; Stewart, L.D.; von Halle, A.; Williams, M.D.

    1982-02-01

    Reionization losses for 1.5 MW H 0 and 2 MW D 0 neutral beams injected into the PDX tokamak were studied using pressure gauges, photo-transistors, thermocouples, surface shielding, and surface sample analysis. Considerable outgassing of conventionally prepared 304SS ducts occurred during initial injections and gradually decreased with the cumulative absorption of beam power. Reionization power losses are presently about 5% in the ducts and about 12% total for a beamline including the duct. Present duct pressures are attributed primarily to gas from the ion source and neutralizer with much smaller contributions from residual wall desorption. Physical mechanisms for the observed duct outgassing are discussed

  7. Water absorption in neutralized Nafion membranes

    International Nuclear Information System (INIS)

    Rodmacq, B.; Roche, E.; Pineri, M.; Escoubez, M.; Duplessix, R.; Eisenberg, A.

    1979-01-01

    In this paper some results are reported about the interactions between water and Nafion neutralized with different cations. The energy of water absorption have been measured in the whole range of relative humidity pressures. Moessbauer spectra permit to get information about the change of environment of the iron atoms during the hydration. Small angle neutron and X ray scattering experiments have then been performed to define a possible phase segregation. From these results a model of clustering in the Nafion membranes is proposed. The neutralized Nafion samples have been obtained by soaking the acid samples in solutions containing the different salts

  8. Neutral beam injection in 2XIIB

    International Nuclear Information System (INIS)

    Hibbs, S.M.

    1975-01-01

    Integrated into the operation of the 2XIIB controlled fusion experiment is a 600-A, 20-keV neutral injection system: the highest neutral-beam current capacity of any existing fusion machine. This paper outlines the requirements of the injection system and the design features to which they led. Both mechanical and electrical aspects are discussed. Also included is a brief description of some operational aspects of the system and some of the things we have learned along the way, as well as a short history of the most significant developments

  9. The net neutrality debate on Twitter

    Directory of Open Access Journals (Sweden)

    Wolf J. Schünemann

    2015-12-01

    Full Text Available The internet has been seen as a medium that empowers individual political actors in relation to established political elites and media gatekeepers. The present article discusses this “net empowerment hypothesis” and tests it empirically by analysing Twitter communication on the regulation of net neutrality. We extracted 503.839 tweets containing #NetNeutrality posted between January and March 2015 and analysed central developments and the network structure of the debate. The empirical results show that traditional actors from media and politics still maintain a central role.

  10. Establishment of Exposure to Organophosphorus Warfare Agents by Means of SPME-GSMS Analysis of Bodily Fluids

    International Nuclear Information System (INIS)

    Saveleva, E. I.; Koryagina, N. L.; Radilov, A. S.; Khlebnikova, N. S.; Khrustaleva, V. S.; Feld, V. E.

    2007-01-01

    Reliable chemical analytical procedures for revealing an exposure to toxic chemicals, identifying the active substance, and assessing the degree of exposure are necessary as a component of medical and forensic activities in cases of the possible use of highly toxic chemicals in war conflicts and terrorism acts, as well as emergency situations in chemical industry, specifically at chemical weapons storage and destruction facilities. According to Chemical Weapons Convention, Part XI, Appendix 4, e-17, 'samples of importance in the investigation of alleged use include biomedical samples from human or animal sources (blood, urine, excreta, tissue etc.)'. Urinary metabolites, O-alkyl esters of methylphosphic acid, offer one of the simplest means of confirming an exposure to organophosphorus warfare agents (OPWA). Urine, unlike blood or tissues, does not require invasive collection demanding in terms of sterility. Excretion with urine is the major route of elimination of OPWA from an organism. According to published data, 90% of OPWA metabolites are excreted within 48-72 h after intoxication. We developed an SPME-GCMS procedure for the determination of O-alkyl esters methylphosphonic acid in urine, with the following detection limits,: isopropyl and isobutyl esters 5 ng/ml and pinacolyl ester 1 ng/ml. The procedure involves derivatization of the target compounds directly on the microfiber. The total analysis time is 1-1.5 h. In animal experiments in vivo we could establish the exposure to OPWA at a half-LD50 level within no less than 48 h after intoxication. In principle, OPWA metabolites could be detected in urine within two weeks after intoxication but at higher doses. Retrospective analysis of urinary metabolites in cases of the exposure to low doses of OPWA requires lower detection limits (0.1-1 ng/ml). Optimal objects for the retrospective analysis of OPWA in an organism are long-lived blood protein adducts. We developed a procedure for revealing an exposure to

  11. Organophosphorus pesticide and ester analysis by using comprehensive two-dimensional gas chromatography with flame photometric detection

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiangping; Li, Dengkun; Li, Jiequan [Nanjing Centre for Disease Control and Prevention, Zizhulin Street, Gulou 210003, Nanjing (China); Rose, Gavin [Department of Environment and Primary Industries, Macleod Centre, Ernest Jones Drive, Macleod, Vic 3085 (Australia); Marriott, Philip J., E-mail: philip.marriott@monash.edu [Australian Centre for Research on Separation Science, School of Chemistry, Monash University, Wellington Road, Clayton 3800 (Australia)

    2013-12-15

    Highlights: • GC × GC-FPD(P-mode) was applied to detection of 37 phosphorus (P)-containing compounds. • The method improves resolution of P-compounds that coelute in the first dimension. • P-compounds are analyzed with excellent sensitivity supported by cryogenic modulation. • The FPD(P-mode) selectivity allows analysis in high hydrocarbon (H/C) matrix. • Soil samples and spiked chemical weapon compounds in H/C matrix are readily screened. -- Abstract: Thirty-seven phosphorus (P)-containing compounds comprising organophosphorus pesticides and organophosphate esters were analyzed by using comprehensive two-dimensional gas chromatography with flame photometric detection in P mode (GC × GC-FPD(P)), with a non-polar/moderately polar column set. A suitable modulation temperature and period was chosen based on experimental observation. A number of co-eluting peak pairs on the {sup 1}D column were well separated in 2D space. Excellent FPD(P) detection selectivity, responding to compounds containing the P atom, produces clear 2D GC × GC plots with little interference from complex hydrocarbon matrices. Limits of detection (LOD) were within the range of 0.0021–0.048 μmol L{sup −1}, and linear calibration correlation coefficients (R{sup 2}) for all 37 P-compounds were at least 0.998. The P-compounds were spiked in 2% diesel and good reproducibility for their response areas and retention times was obtained. Spiked recoveries were 88%–157% for 5 μg L{sup −1} and 80%–138% for 10 μg L{sup −1} spiked levels. Both {sup 1}t{sub R} and {sup 2}t{sub R} shifts were noted when the content of diesel was in excess of 5% in the matrix. Soil samples were analyzed by using the developed method; some P-compounds were positively detected. In general, this study shows that GC × GC-FPD(P) is an accurate, sensitive and simple method for P-compound analysis in complicated environmental samples.

  12. A set of triple-resonance nuclear magnetic resonance experiments for structural characterization of organophosphorus compounds in mixture samples

    Energy Technology Data Exchange (ETDEWEB)

    Koskela, Harri, E-mail: Harri.T.Koskela@helsinki.fi [VERIFIN, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki (Finland)

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer New {sup 1}H, {sup 13}C, {sup 31}P triple-resonance NMR pulse experiments. Black-Right-Pointing-Pointer Analysis of organophosphorus (OP) compounds in complex matrix. Black-Right-Pointing-Pointer Selective extraction of {sup 1}H, {sup 31}P, and {sup 13}C chemical shifts and connectivities. Black-Right-Pointing-Pointer More precise NMR identification of OP nerve agents and their degradation products. - Abstract: The {sup 1}H, {sup 13}C correlation NMR spectroscopy utilizes J{sub CH} couplings in molecules, and provides important structural information from small organic molecules in the form of carbon chemical shifts and carbon-proton connectivities. The full potential of the {sup 1}H, {sup 13}C correlation NMR spectroscopy has not been realized in the Chemical Weapons Convention (CWC) related verification analyses due to the sample matrix, which usually contains a high amount of non-related compounds obscuring the correlations of the relevant compounds. Here, the results of the application of {sup 1}H, {sup 13}C, {sup 31}P triple-resonance NMR spectroscopy in characterization of OP compounds related to the CWC are presented. With a set of two-dimensional triple-resonance experiments the J{sub HP}, J{sub CH} and J{sub PC} couplings are utilized to map the connectivities of the atoms in OP compounds and to extract the carbon chemical shift information. With the use of the proposed pulse sequences the correlations from the OP compounds can be recorded without significant artifacts from the non-OP compound impurities in the sample. Further selectivity of the observed correlations is achieved with the application of phosphorus band-selective pulse in the pulse sequences to assist the analysis of multiple OP compounds in mixture samples. The use of the triple-resonance experiments in the analysis of a complex sample is shown with a test mixture containing typical scheduled OP compounds, including the characteristic degradation

  13. First observations of partially neutralized and quasineutral plasmas in the Columbia Non-neutral Torus

    Science.gov (United States)

    Sarasola, Xabier; Brenner, Paul; Hahn, Michael; Pedersen, Thomas

    2009-11-01

    The Columbia Non-neutral Torus (CNT) is the first stellarator devoted to the study of pure electron, partially neutralized and positron-electron plasmas. To date, CNT usually operates with electron rich plasmas (with negligible ion density) [1], but a stellarator can also confine plasmas of arbitrary degree of neutralization. In CNT the accumulation of ions alters the equilibrium of electron plasmas and a global instability has been observed when the ion fraction exceeds 10 %. A characterization of this instability is presented in [2], analyzing its parameter dependence and spatial structure (non- resonant with rational surfaces). A new set of experiments is currently underway studying plasmas of arbitrary degree of neutralization, ranging from pure electron to quasineutral plasmas. Basic observations show that the plasma potential decouples from emitter bias when we increase the degree of the neutralization of our plasmas. Partially neutralized plasmas are also characterized by multiple mode behavior with dominant modes between 20 and 200 kHz. When the plasma becomes quasineutral, it reverts to single mode behavior. The first results on partially neutralized plasmas confined on magnetic surfaces will be presented. [1] J. Kremer, PRL 97, (2006) 095003 [2] Q. Marksteiner, PRL 100 (2008) 065002

  14. How Objective a Neutral Word Is? A Neutrosophic Approach for the Objectivity Degrees of Neutral Words

    Directory of Open Access Journals (Sweden)

    Mihaela Colhon

    2017-11-01

    Full Text Available In the latest studies concerning the sentiment polarity of words, the authors mostly consider the positive and negative constructions, without paying too much attention to the neutral words, which can have, in fact, significant sentiment degrees. More precisely, not all the neutral words have zero positivity or negativity scores, some of them having quite important nonzero scores for these polarities. At this moment, in the literature, a word is considered neutral if its positive and negative scores are equal, which implies two possibilities: (1 zero positive and negative scores; (2 nonzero, but equal positive and negative scores. It is obvious that these cases represent two different categories of neutral words that must be treated separately by a sentiment analysis task. In this paper, we present a comprehensive study about the neutral words applied to English as is developed with the aid of SentiWordNet 3.0: the publicly available lexical resource for opinion mining. We designed our study in order to provide an accurate classification of the so-called “neutral words” described in terms of sentiment scores and using measures from neutrosophy theory. The intended scope is to fill the gap concerning the neutrality aspect by giving precise measurements for the words’ objectivity.

  15. Neutralization escape mutants define a dominant immunogenic neutralization site on hepatitis A virus

    International Nuclear Information System (INIS)

    Stapleton, J.T.; Lemon, S.M.

    1987-01-01

    Hepatitis A virus is an hepatotrophic human picornavirus which demonstrates little antigenic variability. To topologically map immunogenic sites on hepatitis A virus which elicit neutralizing antibodies, eight neutralizing monoclonal antibodies were evaluated in competition immunoassays employing radiolabeled monoclonal antibodies and HM-175 virus. Whereas two antibodies (K3-4C8 and K3-2F2) bound to intimately overlapping epitopes, the epitope bound by a third antibody (B5-B3) was distinctly different as evidenced by a lack of competition between antibodies for binding to the virus. The other five antibodies variably blocked the binding of both K3-4C8-K3-2F2 and B5-B3, suggesting that these epitopes are closely spaced and perhaps part of a single neutralization immunogenic site. Several combinations of monoclonal antibodies blocked the binding of polyclonal human convalescent antibody by greater than 96%, indicating that the neutralization epitopes bound by these antibodies are immunodominant in humans. Spontaneously arising HM-175 mutants were selected for resistance to monoclonal antibody-mediated neutralization. Neutralization resistance was associated with reduced antibody binding. These results suggest that hepatitis A virus may differ from poliovirus in possessing a single, dominant neutralization immunogenic site and therefore may be a better candidate for synthetic peptide or antiidiotype vaccine development

  16. Is a neutral expression also a neutral stimulus? A study with functional magnetic resonance.

    Science.gov (United States)

    Carvajal, Fernando; Rubio, Sandra; Serrano, Juan M; Ríos-Lago, Marcos; Alvarez-Linera, Juan; Pacheco, Lara; Martín, Pilar

    2013-08-01

    Although neutral faces do not initially convey an explicit emotional message, it has been found that individuals tend to assign them an affective content. Moreover, previous research has shown that affective judgments are mediated by the task they have to perform. Using functional magnetic resonance imaging in 21 healthy participants, we focus this study on the cerebral activity patterns triggered by neutral and emotional faces in two different tasks (social or gender judgments). Results obtained, using conjunction analyses, indicated that viewing both emotional and neutral faces evokes activity in several similar brain areas indicating a common neural substrate. Moreover, neutral faces specifically elicit activation of cerebellum, frontal and temporal areas, while emotional faces involve the cuneus, anterior cingulated gyrus, medial orbitofrontal cortex, posterior superior temporal gyrus, precentral/postcentral gyrus and insula. The task selected was also found to influence brain activity, in that the social task recruited frontal areas while the gender task involved the posterior cingulated, inferior parietal lobule and middle temporal gyrus to a greater extent. Specifically, in the social task viewing neutral faces was associated with longer reaction times and increased activity of left dorsolateral frontal cortex compared with viewing facial expressions of emotions. In contrast, in the same task emotional expressions distinctively activated the left amygdale. The results are discussed taking into consideration the fact that, like other facial expressions, neutral expressions are usually assigned some emotional significance. However, neutral faces evoke a greater activation of circuits probably involved in more elaborate cognitive processing.

  17. Neutron production by neutral beam sources

    International Nuclear Information System (INIS)

    Berkner, K.H.; Massoletti, D.J.; McCaslin, J.B.; Pyle, R.V.; Ruby, L.

    1979-11-01

    Neutron yields, from interactions of multiampere 40- to 120-keV deuterium beams with deuterium atoms implanted in copper targets, have been measured in order to provide input data for shielding of neutral-deuterium beam facilities for magnetic fusion experiments

  18. Neutron production by neutral beam sources

    Energy Technology Data Exchange (ETDEWEB)

    Berkner, K.H.; Massoletti, D.J.; McCaslin, J.B.; Pyle, R.V.; Ruby, L.

    1979-11-01

    Neutron yields, from interactions of multiampere 40- to 120-keV deuterium beams with deuterium atoms implanted in copper targets, have been measured in order to provide input data for shielding of neutral-deuterium beam facilities for magnetic fusion experiments.

  19. The buffer effect in neutral electrolyte supercapacitors

    DEFF Research Database (Denmark)

    Thrane Vindt, Steffen; Skou, Eivind M.

    2016-01-01

    The observation that double-layer capacitors based on neutral aqueous electrolytes can have significantly wider usable potential windows than those based on acidic or alkaline electrolytes is studied. This effect is explained by a local pH change taking place at the electrode surfaces, leading...... potassium nitrate as the electrolyte and potassium phosphates as the buffer system....

  20. Special solutions of neutral functional differential equations

    Directory of Open Access Journals (Sweden)

    Győri István

    2001-01-01

    Full Text Available For a system of nonlinear neutral functional differential equations we prove the existence of an -parameter family of "special solutions" which characterize the asymptotic behavior of all solutions at infinity. For retarded functional differential equations the special solutions used in this paper were introduced by Ryabov.

  1. Engineering problems of future neutral beam injectors

    International Nuclear Information System (INIS)

    Fink, J.

    1977-01-01

    Because there is no limit to the energy or power that can be delivered by a neutral-beam injector, its use will be restricted by either its cost, size, or reliability. Studies show that these factors can be improved by the injector design, and several examples, taken from mirror reactor studies, are given

  2. Development of KSTAR Neutral Beam Heating System

    Energy Technology Data Exchange (ETDEWEB)

    Oh, B. H.; Song, W. S.; Yoon, B. J. (and others)

    2007-10-15

    The prototype components of a neutral beam injection (NBI) system have been developed for the KSTAR, and a capability of the manufactured components has been tested. High power ion source, acceleration power supply, other ion source power supplies, neutralizer, bending magnet for ion beam separation, calorimeter, and cryo-sorption pump have been developed by using the domestic technologies and tested for a neutral beam injection of 8 MW per beamline with a pulse duration of 300 seconds. The developed components have been continuously upgraded to achieve the design requirements. The development technology of high power and long pulse neutral beam injection system has been proved with the achievement of 5.2 MW output for a short pulse length and 1.6 MW output for a pulse length of 300 seconds. Using these development technologies, the domestic NB technology has been stabilized under the development of high power ion source, NB beamline components, high voltage and current power supplies, NB diagnostics, NB system operation and control.

  3. ICAN: High power neutral beam generation

    International Nuclear Information System (INIS)

    Moustaizis, S.D.; Lalousis, P.; Perrakis, K.; Auvray, P.; Larour, J.; Ducret, J.E.; Balcou, P.

    2015-01-01

    During the last few years there is an increasing interest on the development of alternative high power new negative ion source for Tokamak applications. The proposed new neutral beam device presents a number of advantages with respect to: the density current, the acceleration voltage, the relative compact dimension of the negative ion source, and the coupling of a high power laser beam for photo-neutralization of the negative ion beam. Here we numerically investigate, using a multi- fluid 1-D code, the acceleration and the extraction of high power ion beam from a Magnetically Insulated Diode (MID). The diode configuration will be coupled to a high power device capable of extracting a current up to a few kA with an accelerating voltage up to MeV. An efficiency of up to 92% of the coupling of the laser beam, is required in order to obtain a high power, up to GW, neutral beam. The new high energy, high average power, high efficiency (up to 30%) ICAN fiber laser is proposed for both the plasma generation and the photo-neutralizer configuration. (authors)

  4. elative controllability of nonlinear neutral Volterra Integrodiferential ...

    African Journals Online (AJOL)

    In this paper we established sufficient conditions for the relative controllability of the nonlinear neutral volterra integro-differential systems with distributed delays in the control. The results were established using the Schauder's fixed point theorem which is an extension of known results. Journal of the Nigerian Association of ...

  5. If It's Neutral, It's Not Technology

    Science.gov (United States)

    Strate, Lance

    2012-01-01

    Taking a media ecology perspective, this article argues that technology cannot be neutral, because it is a form of change, and it has an inherent bias based on the properties of its materials and methods. Additionally, the application of a technology is an intrinsic part of the technology itself, as is technique, instructions, software, or…

  6. Neutral beam data systems at ORNL

    International Nuclear Information System (INIS)

    Stewart, C.R.

    1982-01-01

    A control system for neutral injection beam lines has been designed, implemented, and used with much success. Despite the problems with very high power levels this system is very successful in relieving the operators burdens of slow conditioning, data recording, and mode switching. The use of computer control with multiple beam lines now appears very promising

  7. Risk neutral second best toll pricing.

    Science.gov (United States)

    2011-08-01

    We propose a risk-neutral second best toll pricing scheme to account for the possible no uniqueness : of user equilibrium solutions. The scheme is designed to optimize for the expected objective value : as the UE solution varies within the solution s...

  8. Neutral theory of chemical reaction networks

    International Nuclear Information System (INIS)

    Lee, Sang Hoon; Holme, Petter; Minnhagen, Petter; Bernhardsson, Sebastian; Kim, Beom Jun

    2012-01-01

    To what extent do the characteristic features of a chemical reaction network reflect its purpose and function? In general, one argues that correlations between specific features and specific functions are key to understanding a complex structure. However, specific features may sometimes be neutral and uncorrelated with any system-specific purpose, function or causal chain. Such neutral features are caused by chance and randomness. Here we compare two classes of chemical networks: one that has been subjected to biological evolution (the chemical reaction network of metabolism in living cells) and one that has not (the atmospheric planetary chemical reaction networks). Their degree distributions are shown to share the very same neutral system-independent features. The shape of the broad distributions is to a large extent controlled by a single parameter, the network size. From this perspective, there is little difference between atmospheric and metabolic networks; they are just different sizes of the same random assembling network. In other words, the shape of the degree distribution is a neutral characteristic feature and has no functional or evolutionary implications in itself; it is not a matter of life and death. (paper)

  9. Neutral gas transport modeling with DEGAS 2

    International Nuclear Information System (INIS)

    Karney, C.; Stotler, D.

    1993-01-01

    The authors are currently re-writing the neutral gas transport code, DEGAS, with a view to making it both faster and easier to include new physics. They present model calculations including ionization and charge exchange illustrating the way that reactions are included into DEGAS 2 and its operation on a distributed network of workstations

  10. Niche versus neutrality: a dynamical analysis

    Science.gov (United States)

    Michael Kalyuzhny; Efrat Seri; Rachel Chocron; Curtis H. Flather; Ronen Kadmon; Nadav M. Shnerb

    2014-01-01

    Understanding the forces shaping ecological communities is of crucial importance for basic science and conservation. After 50 years in which ecological theory has focused on either stable communities driven by niche-based forces or nonstable “neutral” communities driven by demographic stochasticity, contemporary theories suggest that ecological communities are driven...

  11. Neutral anion receptors: design and application

    NARCIS (Netherlands)

    Antonisse, M.M.G.; Reinhoudt, David

    1998-01-01

    After the development of synthetic cation receptors in the late 1960s, only in the past decade has work started on the development of synthetic neutral anion receptors. Combination and preorganization of different anion binding groups, like amides, urea moieties, or Lewis acidic metal centers lead

  12. Laser cooling and trapping of neutral atoms

    International Nuclear Information System (INIS)

    Phillips, W.D.

    1998-01-01

    The article is a translation of the lecture given on the occasion of the 1997 Nobel Prize awarding ceremony. The history of the discovery of laser cooling and trapping of neutral atoms is described. An explanation of this phenomenon is presented and the author's personal contribution to the discovery is highlighted. The article is completed by Dr. Phillips' autobiography. (Z.J.)

  13. Possible neutral beam requirements for TFTR upgrades

    International Nuclear Information System (INIS)

    Prichard, B.A. Jr.; Little, R.; Post, D.E.; Schmidt, J.A.

    1977-01-01

    A discussion is provided of possible neutral beam requirements and constraints for a TFTR upgrade. The time scale is the early 80s and beams of 250 keV D 0 , probably using 65 ampere negative ion sources, existing power supplies and vacuum enclosures would be required

  14. Transition radiation of ultrarelativistic neutral particles

    International Nuclear Information System (INIS)

    Grimus, W.; Neufeld, H.

    1994-10-01

    We perform a quantum theoretical calculation of transition radiation by neutral particles with spin 1/2 equipped with magnetic moments and/or electric dipole moments. The limit of vanishing masses is treated exactly for arbitrary refraction index. Finally we apply our result to the solar neutrino flux. (author)

  15. A storage ring for neutral molecules

    NARCIS (Netherlands)

    Crompvoets, F.M.H.

    2005-01-01

    Time-varying inhomogeneous electric fields can be used to manipulate the motion of neutral molecules in phase-space, i.e., position-momentum space, via their electric dipole moment. A theoretical background is given on the motion of the molecules in phase-space. As the forces exerted on the

  16. Modeling of the lithium based neutralizer for ITER neutral beam injector

    Energy Technology Data Exchange (ETDEWEB)

    Dure, F., E-mail: franck.dure@u-psud.fr [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France); Lifschitz, A.; Bretagne, J.; Maynard, G. [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France); Simonin, A. [IRFM, Institut de Recherche sur la Fusion Magnetique, CEA Cadarache, 13108 Saint-Paul lez Durance (France); Minea, T. [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France)

    2012-04-04

    Highlights: Black-Right-Pointing-Pointer We compare different lithium based neutraliser configurations to the deuterium one. Black-Right-Pointing-Pointer We study characteristics of the secondary plasma and the propagation of the 1 MeV beam. Black-Right-Pointing-Pointer Using lithium increases the neutralisation effiency keeping correct beam focusing. Black-Right-Pointing-Pointer Using lithium also reduces the backstreaming effect in direction of the ion source. - Abstract: To achieve thermonuclear temperatures necessary to produce fusion reactions in the ITER Tokamak, additional heating systems are required. One of the main method to heat the plasma ions in ITER will be the injection of energetic neutrals (NBI). In the neutral beam injector, negative ions (D{sup -}) are electrostatically accelerated to 1 MeV, and then stripped of their extra electron via collisions with a target gas, in a structure known as neutralizer. In the current ITER specification, the target gas is deuterium. It has been recently proposed to use lithium vapor instead of deuterium as target gas in the neutralizer. This would allow to reduce the gas load in the NBI vessel and to improve the neutralization efficiency. A Particle-in-Cell Monte Carlo code has been developed to study the transport of the beams and the plasma formation in the neutralizer. A comparison between Li and D{sub 2} based neutralizers made with this code is presented here, as well as a parametric study on the geometry of the Li based neutralizer. Results demonstrate the feasibility of a Li based neutralizer, and its advantages with respect to the deuterium based one.

  17. Gaz Phase IR and UV Spectroscopy of Neutral Contact Ion Pairs

    Science.gov (United States)

    Habka, Sana; Brenner, Valerie; Mons, Michel; Gloaguen, Eric

    2016-06-01

    Cations and anions, in solution, tend to pair up forming ion pairs. They play a crucial role in many fundamental processes in ion-concentrated solutions and living organisms. Despite their importance and vast applications in physics, chemistry and biochemistry, they remain difficult to characterize namely because of the coexistence of several types of pairing in solution. However, an interesting alternative consists in applying highly selective gas phase spectroscopy which can offer new insights on these neutral ion pairs. Our study consists in characterizing contact ion pairs (CIPs) in isolated model systems (M+, Ph-(CH2)n-COO- with M=Li, Na, K, Rb, Cs, and n=1-3), to determine their spectral signatures and compare them to ion pairs in solution. We have used laser desorption to vaporize a solid tablet containing the desired salt. Structural information for each system was obtained by mass-selective, UV and IR laser spectroscopy combined with high level quantum chemistry calculations1. Evidence of the presence of neutral CIPs was found by scanning the π-π* transition of the phenyl ring using resonant two-photon ionization (R2PI). Then, conformational selective IR/UV double resonance spectra were recorded in the CO2- stretch region for each conformation detected. The good agreement between theoretical data obtained at the BSSE-corrected-fullCCSD(T)/dhf-TZVPP//B97-D3/dhf-TZVPP level and experimental IR spectra led us to assign the 3D structure for each ion pair formed. Spectral signatures of (M+, Ph-CH2-COO-) pairs, were assigned to a bidentate CIPs between the alkali cation and the carboxylate group. In the case of (Li+, Ph-(CH2)3-COO-) pairs, the presence of a flexible side chain promotes a cation-π interaction leading to a tridentate O-O-π structure with its unique IR and UV signatures. IR spectra obtained on isolated CIPs were found very much alike the ones published on lithium and sodium acetate in solution2. However, in the case of sodium acetate, solution

  18. Misconceptions and false expectations in neutral evolution

    Directory of Open Access Journals (Sweden)

    CARLOS Y. VALENZUELA

    2000-01-01

    Full Text Available Neutral evolution results from random recurrent mutation and genetic drift. A small part of random evolution, that which is related to protein or DNA polymorphisms, is the subject of the Neutral Theory of Evolution. One of the foundations of this theory is the demonstration that the mutation rate (m is equal to the substitution rate. Since both rates are independent of population size, they are independent of drift, which is dependent upon population size. Neutralists have erroneously equated the substitution rate with the fixation rate, despite the fact that they are antithetical conceptions. The neutralists then applied the random walk stochastic model to justify alleles or bases that were fixated or eliminated. In this model, once the allele or base frequencies reach the monomorphic states (values of 1.0 or 0.0, the absorbing barriers, they can no longer return to the polymorphic state. This operates in a pure mathematical model. If recurrent mutation occurs (as in biotic real systems fixation and elimination are impossible. A population of bacteria in which m=10-8 base mutation (or substitution/site/generation and the reproduction rate is 1000 cell cycle/year should replace all its genome bases in approximately 100,000 years. The expected situation for all sites is polymorphism for the four bases rather than monomorphism at 1.0 or 0.0 frequencies. If fixation and elimination of a base for more than 500,000 years are impossible, then most of the neutral theory is untenable. A new complete neutral model, which allows for recurrent substitutions, is proposed here based on recurrent mutation or substitution and drift alone. The model fits a binomial or Poisson distribution and not a geometric one, as does neutral theory.

  19. Simultaneous determination of organophosphorus pesticides and phthalates in baby food samples by ultrasound-vortex-assisted liquid-liquid microextraction and GC-IT/MS.

    Science.gov (United States)

    Notardonato, Ivan; Salimei, Elisabetta; Russo, Mario Vincenzo; Avino, Pasquale

    2018-05-01

    Baby foods are either a soft, liquid paste or an easily chewed food since babies lack developed muscles and teeth to chew effectively. Babies typically move to consuming baby food once nursing or formula is not sufficient for the child's appetite. Some commercial baby foods have been criticized for their contents. This article focuses on the simultaneous determination of organophosphorus pesticides and phthalates by means of a method based on ultrasound-vortex-assisted liquid-liquid microextraction coupled with gas chromatography-ion trap mass spectrometry (GC-IT/MS). The protocol developed allowed the determination of six phthalates [dimethyl phthalate, diethyl phthalate, dibutyl phthalate, isobutyl cyclohexyl phthalate, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate] and 19 organophosphorus pesticides. Freeze-dried product samples (0.1-0.2 g) were dissolved in 10 mL of warm distilled water along with 5 μL of an internal standard (anthracene at 10 mg mL -1 in acetone): the choice of extraction solvent was studied, with the most suitable being n-heptane, which is used for phthalate determination in similar matrices. The solution, held for 5 min in a vortex mixer and for 6 min in a 100-W ultrasonic bath to favor solvent dispersion and consequently analyte extraction, was centrifuged at 4000 rpm for 30 min. Then 1 μL was injected into the GC-IT/MS system (SE-54 capillary column; length 30 m, inner diameter 250 μm, film thickness 0.25 μm). All analytical parameters investigated are discussed in depth. The method was applied to real commercial freeze-dried samples: significant contaminant concentrations were not found. Graphical abstract Simultaneous and sensitive determination of organophosphorus pesticides and phthalates in baby foods by the ultrasound-vortex-assisted liquid-liquid microextraction ֪gas chromatography-ion trap mass spectrometry procedure. 1 methacrifos, 2 pirofos, 3 phorate, 4 seraphos, 5 diazinon, 6 etrimphos, 7 dichlofenthion, 8

  20. Research on Stress Neutral Layer Offset in the Straightening Process

    Directory of Open Access Journals (Sweden)

    Hailian Gui

    2015-01-01

    Full Text Available The stress neutral layer offset is analyzed by theoretical and numerical calculation methods. In traditional straightening theory, the stress neutral layer was consistent with the geometric central layer. However, there is a phenomenon that the stress neutral layer has some offset with the geometric neutral layer. This offset is a very important factor for improving the precision of the straightening force. The formula of the stress neutral layer offset is obtained by a theoretical method and the change law is given by numerical calculation method. The neutral layer offset theory provides the theoretical basis for establishing the model of straightening force precisely.

  1. High-performance liquid chromatography using reversed-phase stationary phases dynamically modified with organophosphorus compound for the separation and determination of lanthanoid elements

    International Nuclear Information System (INIS)

    Tsuyoshi, Akira; Akiba, Kenichi

    2000-01-01

    An acidic organophosphorus compound, 2-ethylhexylphosphonic acid mono-2-ethlhexyl ester (EHPA), has been applied to reversed-phase high-performance liquid chromatography (RP-HPLC). The reversed-phase stationary phase was dynamically modified with EHPA by flowing the mobile phase of an acetone-water mixture containing the extracting regent. The retention of lanthanoid elements was widely varied by changing the conditions of the mobile phase, i.e., the pH, the EHPA concentration and the acetone content. The selectivity of EHPA is well reflected to the chromatographic systems, and a precise separation of lanthanoid elements was achieved with sufficient resolution. The determination of Sm was examined in the presence of a large amount of Nd. A linear calibration graph was obtained for Sm at the level of 10 -7 mol dm -3 , in the presence of 1x10 -4 mol dm -3 of Nd. (author)

  2. (IAM Series No 005) Are “Market Neutral” Hedge Funds Really Market Neutral?

    OpenAIRE

    Andrew Patton

    2004-01-01

    One can consider the concept of market neutrality for hedge funds as having breadth and depth: breadth reflects the number of market risks to which a fund is neutral, while depth reflects the completeness of the neutrality of the fund to market risks. We focus on market neutrality depth, and propose five different neutrality concepts. Mean neutrality nests the standard correlation-based definition of neutrality. Variance neutrality, Value-at-Risk neutrality and tail neutrality all relate to t...

  3. Acute effects of a sarin-like organophosphorus agent, bis(isopropyl methyl)phosphonate, on cardiovascular parameters in anaesthetized, artificially ventilated rats

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Yoshimasa [Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Itoh, Takeo, E-mail: titoh@med.nagoya-cu.ac.jp [Department of Pharmacology, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Shiraishi, Hiroaki [Department of Forensic Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Maeno, Yoshitaka [Department of Forensic Medical Science, Graduate School of Medical Sciences, Nagoya City University, Nagoya (Japan); Arima, Yosuke; Torikoshi, Aiko; Namera, Akira [Department of Forensic Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Makita, Ryosuke [Department of Nursing, Faculty of Health Sciences, Hiroshima Cosmopolitan University, Hiroshima (Japan); Yoshizumi, Masao [Department of Cardiovascular Physiology and Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Nagao, Masataka [Department of Forensic Medicine, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan)

    2013-10-01

    The organophosphorus compound sarin irreversibly inhibits acetylcholinesterase. We examined the acute cardiovascular effects of a sarin-like organophosphorus agent, bis(isopropyl methyl)phosphonate (BIMP), in anaesthetized, artificially ventilated rats. Intravenous administration of BIMP (0.8 mg/kg; the LD50 value) induced a long-lasting increase in blood pressure and tended to increase heart rate. In rats pretreated with the non-selective muscarinic-receptor antagonist atropine, BIMP significantly increased both heart rate and blood pressure. In atropine-treated rats, hexamethonium (antagonist of ganglionic nicotinic receptors) greatly attenuated the BIMP-induced increase in blood pressure without changing the BIMP-induced increase in heart rate. In rats treated with atropine plus hexamethonium, intravenous phentolamine (non-selective α-adrenergic receptor antagonist) plus propranolol (non-selective β-adrenergic receptor antagonist) completely blocked the BIMP-induced increases in blood pressure and heart rate. In atropine-treated rats, the reversible acetylcholinesterase inhibitor neostigmine (1 mg/kg) induced a transient increase in blood pressure, but had no effect on heart rate. These results suggest that in anaesthetized rats, BIMP induces powerful stimulation of sympathetic as well as parasympathetic nerves and thereby modulates heart rate and blood pressure. They may also indicate that an action independent of acetylcholinesterase inhibition contributes to the acute cardiovascular responses induced by BIMP. - Highlights: • A sarin-like agent BIMP markedly increased blood pressure in anaesthetized rats. • Muscarinic receptor blockade enhanced the BIMP-induced increase in blood pressure. • Ganglionic nicotinic receptor blockade attenuated the BIMP-induced response. • Blockade of α- as well as β-receptors attenuated the BIMP-induced response.

  4. Quantitative structure-activity analysis of acetylcholinesterase inhibition by oxono and thiono analogues of organophosphorus compounds. (Reannouncement with new availability information)

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, D.M.; Brecht, K.M.

    1992-02-01

    A comparison of the bimolecular rate constants (ki) for inhibition of electric eel acetylcholinesterase (AChE) by the oxono (i.e., P=O) and thiono (i.e., P=S) analogues of parathion, methylparathion, leptophos, fonofos, sarin, and soman revealed that the oxono/thiono ratios of ki values varied from 14 for soman to 1240 for parathion. Analysis of the relative importance of the dissociation equilibrium constant and the phosphorylation rate constant in producing this variation in ki values indicated that the oxono analogues had phosphorylation rate constant values that varied in a narrow range from 8- to 14-fold greater than their thiono counterparts, while the oxono/thiono ratios for dissociation constants varied widely from 1 for soman to 82 for fonofos. The lower affinities of thiono analogues for AChE probably resulted from differences in the hydrophobic binding of oxono and thiono analogues to the active site of AChE, inasmuch as the hydrophobicities (i.e., octanol/water partition coefficients) of thiono organophosphorus compounds were much greater than the hydrophobicities of their oxono analogues. Quantitative structure-activity analysis indicated that the hydrophobic effects of oxono and thiono moieties correlated with log ki for AChE inhibition to a greater extent (r2 = 0.79) than their electronic effects (r2 equal to or less than 0.48). These observations suggest that the differences in hydrophobicity of oxono and thiono analogues of organophosphorus compounds may be as important as their electronic differences in determining their effectiveness as AChE inhibitors. Acetylcholinesterase, soman (GD), structure-activity analysis inhibition, oxono analogues, thiono analogues.

  5. Acute effects of a sarin-like organophosphorus agent, bis(isopropyl methyl)phosphonate, on cardiovascular parameters in anaesthetized, artificially ventilated rats

    International Nuclear Information System (INIS)

    Watanabe, Yoshimasa; Itoh, Takeo; Shiraishi, Hiroaki; Maeno, Yoshitaka; Arima, Yosuke; Torikoshi, Aiko; Namera, Akira; Makita, Ryosuke; Yoshizumi, Masao; Nagao, Masataka

    2013-01-01

    The organophosphorus compound sarin irreversibly inhibits acetylcholinesterase. We examined the acute cardiovascular effects of a sarin-like organophosphorus agent, bis(isopropyl methyl)phosphonate (BIMP), in anaesthetized, artificially ventilated rats. Intravenous administration of BIMP (0.8 mg/kg; the LD50 value) induced a long-lasting increase in blood pressure and tended to increase heart rate. In rats pretreated with the non-selective muscarinic-receptor antagonist atropine, BIMP significantly increased both heart rate and blood pressure. In atropine-treated rats, hexamethonium (antagonist of ganglionic nicotinic receptors) greatly attenuated the BIMP-induced increase in blood pressure without changing the BIMP-induced increase in heart rate. In rats treated with atropine plus hexamethonium, intravenous phentolamine (non-selective α-adrenergic receptor antagonist) plus propranolol (non-selective β-adrenergic receptor antagonist) completely blocked the BIMP-induced increases in blood pressure and heart rate. In atropine-treated rats, the reversible acetylcholinesterase inhibitor neostigmine (1 mg/kg) induced a transient increase in blood pressure, but had no effect on heart rate. These results suggest that in anaesthetized rats, BIMP induces powerful stimulation of sympathetic as well as parasympathetic nerves and thereby modulates heart rate and blood pressure. They may also indicate that an action independent of acetylcholinesterase inhibition contributes to the acute cardiovascular responses induced by BIMP. - Highlights: • A sarin-like agent BIMP markedly increased blood pressure in anaesthetized rats. • Muscarinic receptor blockade enhanced the BIMP-induced increase in blood pressure. • Ganglionic nicotinic receptor blockade attenuated the BIMP-induced response. • Blockade of α- as well as β-receptors attenuated the BIMP-induced response

  6. Summary of fueling by neutral beams

    International Nuclear Information System (INIS)

    Jassby, D.L.

    1978-01-01

    Injected neutral beams supply energy, particles, and momentum to a plasma, while the thermalizing fast ions also increase the fusion reactivity by beam-target or hot-ion reactions. Magnetic mirror machines take advantage of all of these features, with the exception of the momentum input. Neutral-beam injection into toroidal plasmas has been proposed and has so far been utilized mainly as a source of heat, and secondarily as a source of increased neutron production. Nevertheless, fueling by injected beams can also play an important role in toroidal plasmas, especially in the start-up phase of ignited plasmas, or for the quasi-steady maintenance of low-Q plasmas where the average ion energy may exceed the electron energy by a large factor

  7. A new approach to entangling neutral atoms.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jongmin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Michael J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jau, Yuan-Yu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Deutsch, Ivan H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Biedermann, Grant W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    Our team has developed a new approach to entangling neutral atoms with a Rydberg-dressed interaction. Entangling neutral atoms is an essential key of quantum technologies such as quantum computation, many-body quantum simulation, and high-precision atomic sensors . The demonstrated Rydberg-dressed protocol involves adiabatically imposing a light shift on the ground state by coupling an excited Rydberg state with a tuned laser field. Using this technique, we have demonstrated a strong and tunable dipole - dipole interaction between two individually trapped atoms with energy shifts of order 1 MHz, which has been challenging to achieve in other protocols . During this program, we experimentally demonstrated Bell-state entanglement and the isomorphism to the Jaynes - Cumming model of a Rydberg-dressed two-atom system. Our theoretical calculations of a CPHASE quantum logic gate and arbitrary Dicke state quantum control in this system encourage further work.

  8. Particle reflection and TFTR neutral beam diagnostics

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Grisham, L.R.; Kugel, H.W.; O'Connor, T.E.; Newman, R.A.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1992-04-01

    Determination of two critical neutral beam parameters, power and divergence, are affected by the reflection of a fraction of the incident energy from the surface of the measuring calorimeter. On the TFTR Neutral Beam Test Stand, greater than 30% of the incident power directed at the target chamber calorimeter was unaccounted for. Most of this loss is believed due to reflection from the surface of the flat calorimeter, which was struck at a near grazing incidence (12 degrees). Beamline calorimeters, of a ''V''-shape design, while retaining the beam power, also suffer from reflection effects. Reflection, in this latter case, artificially peaks the power toward the apex of the ''V'', complicating the fitting technique, and increasing the power density on axis by 10 to 20%; an effect of import to future beamline designers. Agreement is found between measured and expected divergence values, even with 24% of the incident energy reflected

  9. Fast Neutral Pressure Gauges in NSTX

    International Nuclear Information System (INIS)

    Raman, R.; Kugel, H.W.; Gernhardt, R.; Provost, T.; Jarboe, T.R.; Soukhanovskii, V.

    2004-01-01

    Successful operation in NSTX of two prototype fast-response micro ionization gauges during plasma operations has motivated us to install five gauges at different toroidal and poloidal locations to measure the edge neutral pressure and its dependence on the type of discharge (L-mode, H-mode, CHI) and the fueling method and location. The edge neutral pressure is also used as an input to the transport analysis codes TRANSP and DEGAS-2. The modified PDX-type Penning gauges are well suited for pressure measurements in the NSTX divertor where the toroidal field is relatively high. Behind the NSTX outer divertor plates where the field is lower, an unshielded fast ion gauge of a new design has been installed. This gauge was developed after laboratory testing of several different designs in a vacuum chamber with applied magnetic fields

  10. Mass separated neutral particle energy analyser

    International Nuclear Information System (INIS)

    Takeuchi, Hiroshi; Matsuda, Toshiaki; Miura, Yukitoshi; Shiho, Makoto; Maeda, Hikosuke; Hashimoto, Kiyoshi; Hayashi, Kazuo.

    1983-09-01

    A mass separated neutral particle energy analyser which could simultaneously measure hydrogen and deuterium atoms emitted from tokamak plasma was constructed. The analyser was calibrated for the energy and mass separation in the energy range from 0.4 keV to 9 keV. In order to investigate the behavior of deuteron and proton in the JFT-2 tokamak plasma heated with ion cyclotron wave and neutral beam injection, this analyser was installed in JFT-2 tokamak. It was found that the energy spectrum could be determined with sufficient accuracy. The obtained ion temperature and ratio of deuteron and proton density from the energy spectrum were in good agreement with the value deduced from Doppler broadening of TiXIV line and the line intensities of H sub(α) and D sub(α) respectively. (author)

  11. Thermal Conductivity of the Multicomponent Neutral Atmosphere

    Science.gov (United States)

    Pavlov, A. V.

    2017-12-01

    Approximate expressions for the thermal conductivity coefficient of the multicomponent neutral atmosphere consisting of N2, O2, O, He, and H are analyzed and evaluated for the atmospheric conditions by comparing them with that given by the rigorous hydrodynamic theory. The new approximations of the thermal conductivity coefficients of simple gases N2, O2, O, He, and H are derived and used. It is proved that the modified Mason and Saxena approximation of the atmospheric thermal conductivity coefficient is more accurate in reproducing the atmospheric values of the rigorous hydrodynamic thermal conductivity coefficient in comparison with those that are generally accepted in atmospheric studies. This approximation of the thermal conductivity coefficient is recommended to use in calculations of the neutral temperature of the atmosphere.

  12. Biofilm community succession: a neutral perspective.

    Science.gov (United States)

    Woodcock, Stephen; Sloan, William T

    2017-05-22

    Although biofilms represent one of the dominant forms of life in aqueous environments, our understanding of the assembly and development of their microbial communities remains relatively poor. In recent years, several studies have addressed this and have extended the concepts of succession theory in classical ecology into microbial systems. From these datasets, niche-based conceptual models have been developed explaining observed biodiversity patterns and their dynamics. These models have not, however, been formulated mathematically and so remain untested. Here, we further develop spatially resolved neutral community models and demonstrate that these can also explain these patterns and offer alternative explanations of microbial succession. The success of neutral models suggests that stochastic effects alone may have a much greater influence on microbial community succession than previously acknowledged. Furthermore, such models are much more readily parameterised and can be used as the foundation of more complex and realistic models of microbial community succession.

  13. Neutralization method for a hydrofluoric acid release

    International Nuclear Information System (INIS)

    Williams, D.L.; Deacon, L.E.

    1976-01-01

    A laboratory investigation of methods for neutralizing a release at the hydrofluoric acid tank farm at the Portsmouth Gaseous Diffusion Plant has revealed that the best neutralization method incorporates the use of a lime/water slurry. In this method, settling of suspended solids in the liquid is enhanced by the application of sodium dodecyl sulfate, which causes immediate flocculation and settling. Dilution and expulsion of the supernatant liquid above the flocculated solids result in an effluent which meets the one part per million fluoride limit established by the U.S. Environmental Protection Agency. A fluoride specific ion electrode is used to determine fluoride concentration. This method presently is being adapted for use in the hydrofluoric acid tank farm and is being considered for use at the plant's fluorine generation facility. It could be adapted for use in any facility that contains fluoride in aqueous solution

  14. Capacitive Neutralization Dialysis for Direct Energy Generation.

    Science.gov (United States)

    Liu, Yue; Zhang, Yi; Ou-Yang, Wei; Bastos Sales, Bruno; Sun, Zhuo; Liu, Fei; Zhao, Ran

    2017-08-15

    Capacitive neutralization dialysis energy (CNDE) is proposed as a novel energy-harvesting technique that is able to utilize waste acid and alkaline solutions to produce electrical energy. CNDE is a modification based on neutralization dialysis. It was found that a higher NaCl concentration led to a higher open-circuit potential when the concentrations of acid and alkaline solutions were fixed. Upon closing of the circuit, the membrane potential was used as a driving force to move counter ions into the electrical double layers at the electrode-liquid interface, thereby creating an ionic current. Correspondingly, in the external circuit, electrons flow through an external resistor from one electrode to the other, thereby generating electrical energy directly. The influence of external resistances was studied to achieve greater energy extraction, with the maximum output of 110 mW/m 2 obtained by employing an external resistance of 5 Ω together with the AC-coated electrode.

  15. Neutral Particle Analyzer Diagnostic on NSTX

    International Nuclear Information System (INIS)

    Medley, S.S.; Roquemore, A.L.

    2004-01-01

    The Neutral Particle Analyzer (NPA) diagnostic on the National Spherical Torus Experiment (NSTX) utilizes a PPPL-designed E||B spectrometer that measures the energy spectra of minority hydrogen and bulk deuterium species simultaneously with 39 energy channels per mass specie and a time resolution of 1 ms. The calibrated energy range is E = 0.5-150 keV and the energy resolution varies from AE/E = 3-7% over the surface of the microchannel plate detector

  16. PLT neutral injection ignitron accelerating supply

    International Nuclear Information System (INIS)

    Ashcroft, D.L.; Murray, J.G.; Newman, R.A.; Peterson, F.L.

    1975-11-01

    A phase-controlled rectifier was designed for the accelerating supply on the PLT Neutral Beam Injection system at PPPL. The rectifier must furnish 70 amperes at up to 50 KV for 300 milliseconds, with a duty cycle of up to 10 percent. Protection of the injectors requires the supply to withstand repeated crowbarring. The rectifying element selected to satisfy these requirements was a commercially-available ignitron, installed in a supporting frame and using firing circuits and controls designed by PPPL

  17. Neutral Particle Analyzer Diagnostic on NSTX

    Energy Technology Data Exchange (ETDEWEB)

    S.S. Medley; A.L. Roquemore

    2004-03-16

    The Neutral Particle Analyzer (NPA) diagnostic on the National Spherical Torus Experiment (NSTX) utilizes a PPPL-designed E||B spectrometer that measures the energy spectra of minority hydrogen and bulk deuterium species simultaneously with 39 energy channels per mass specie and a time resolution of 1 ms. The calibrated energy range is E = 0.5-150 keV and the energy resolution varies from AE/E = 3-7% over the surface of the microchannel plate detector.

  18. Neutral beam source commercialization study. Final report

    International Nuclear Information System (INIS)

    King, H.J.

    1980-06-01

    The basic tasks of this Phase II project were to: generate a set of design drawings suitable for quantity production of sources of this design; fabricate a functional neutral beam source incorporating as many of the proposed design changes as proved feasible; and document the procedures and findings developed during the contract. These tasks have been accomplished and represent a demonstrated milestone in the industrialization of this complete device

  19. What is a truly neutral particle?

    International Nuclear Information System (INIS)

    Tsan, Ung Chan

    2004-01-01

    An electrically charged particle is necessarily different from its antiparticle while an electrically neutral particle is either identical with or different from its antiparticle. A truly neutral particle is a particle identical to its antiparticle, which means that all its algebraic intrinsic properties are equal to zero since particle and antiparticle have all their algebraic intrinsic properties opposite. We propose two complementary methods to recognize the true nature of any electrically neutral particle. On the one hand, any non-null algebraic intrinsic property of a particle (properties such as Q, magnetic moment already known from classical physics, or quantum numbers such as baryonic number A, lepton number L or flavors, which are meaningful only in the quantum world) reveals that it is distinct from its antiparticle. On the other hand, any particle decaying through a self-conjugate channel or/and through both two conjugate channels is a truly neutral particle implying then that all algebraic intrinsic properties, known or yet unknown, of this particle are null. According to these methods, the neutrino, like any fermion, cannot be its own antiparticle, so neutrinoless double beta decay cannot take place in nature. We point out the internal contradiction required by the existence of hypothetical neutrinoless double beta decay. We suggest that persistent failure to find experimental evidence for this decay mechanism despite huge efforts dedicated to this aim is consistent with the physics of this process. The immediate consequence would be that limits of neutrino mass deduced from neutrinoless double beta decay cannot be used as constraints in contrast with mass limits deduced from the behavior of the end-point in simple beta spectra. (author)

  20. PLT neutral injection ignitron accelerating supply

    International Nuclear Information System (INIS)

    Ashcroft, D.L.; Murray, J.G.; Newman, R.A.; Peterson, F.L.

    1976-03-01

    A phase-controlled rectifier has been designed for the accelerating supply on the PLT Neutral Beam Injection system at PPPL. The rectifier must furnish 70 amperes at up to 50 KV for 300 milliseconds, with a duty cycle of up to 10 percent. Protection of the injectors requires the supply to withstand repeated crowbarring. The rectifying element selected to satisfy these requirements was a commercially-available ignitron, installed in a supporting frame and using firing circuits and controls designed by PPPL