WorldWideScience

Sample records for bidentate neutral organophosphorus

  1. Method for purifying bidentate organophosphorus compounds

    Science.gov (United States)

    Schulz, Wallace 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. Extraction chemistry of some bidentate organophosphorus compounds

    Energy Technology Data Exchange (ETDEWEB)

    Martella, L.L.; Navratil, J.D.; Santiago, W.F.

    1978-01-01

    The extraction chemistry of methylenediphosphonates, carbamoylphosphonates, and carbamoylmethylenephosphonates has been investigated. The bidentate organophosphorus compounds extract actinides strongly, extract lanthanides, iron, gallium, molybdenum, titanium, vanadium, and zirconium partially, and do not extract most other elements from 5 to 7 M nitric acid. The properties of the extractants and extraction mechanisms are discussed. The effect of complexing agents on the extraction of actinides and lanthanides is also presented.

  3. Bidentate organophosphorus extraction of americium and plutonium from Hanford Plutonium Reclamation Facility waste

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.W.

    1974-09-01

    Applicability of bidentate organiphosphorus reagents to recovery of americium and plutonium from Hanford's Plutonium Reclamation Facility acid (approx. 2M HNO/sub 3/) waste stream (CAW solution) was studied. A solvent extraction process which employs a 30% DHDECMP (dihexyl-N, N-diethylcarbamylmethylene phosphonate)-CCl/sub 4/ extractant was devised and successfully tested in mixer-settler runs with actual CAW solution. Substitution of DHDECMP for DBBP eliminates the need to perform careful neutralization of unbuffered CAW soluton and increases overall americium recovery from the present 60 to 80% level to greater than or equal to 90%. Disadvantages to such substitution include the high cost (approx. $50/liter) of DHDECMP and the need to purify it (by acid (6M HCl) hydrolysis and alkaline washing) from small amounts of an unidentified impurity which prevents stripping of americium with dilute HNO/sub 3/. Distribution data obtained in this study confirm Siddall's earlier contention that bidentate organophosphorus regents can be used to remove actinides from concentrated high-level Purex process acid waste; a conceptual flowsheet for such an extraction process is given.

  4. Bidentate organophosphorus compounds as extractants from acidic waste solutions: a comparative and systematic study

    Energy Technology Data Exchange (ETDEWEB)

    Shoun, R.R.; McDowell, W.J.; Weaver, B.

    1977-01-01

    A comparative study has been made of several bidentate organophosphorus compounds. Tetraalkyl carbamoylmethylphosphonates and tetraalkylalkyl diphosphonates were tested for their ability to extract americium from nitric acid. Aromatic, aliphatic, and mixed diluents were compared as to the effect on extraction behavior, aqueous-phase solubility, and organic-phase solubility. Reagent and acid dependences are presented for selected compounds.

  5. Bidentate organophosphorus solvent extraction process for actinide recovery and partition

    Science.gov (United States)

    Schulz, Wallace W.

    1976-01-01

    A liquid-liquid extraction process for the recovery and partitioning of actinide values from acidic nuclear waste aqueous solutions, the actinide values including trivalent, tetravalent and hexavalent oxidation states is provided and includes the steps of contacting the aqueous solution with a bidentate organophosphorous extractant to extract essentially all of the actinide values into the organic phase. Thereafter the respective actinide fractions are selectively partitioned into separate aqueous solutions by contact with dilute nitric or nitric-hydrofluoric acid solutions. The hexavalent uranium is finally removed from the organic phase by contact with a dilute sodium carbonate solution.

  6. Influence of the structure of bidentate organophosphorus compounds and their extraction capacity

    International Nuclear Information System (INIS)

    This paper studies the variation of the extraction capacity within a broad series of didentate organophosphorus compounds, from diphosphine dioxides to carbamoylphosphine oxides and phosphonates. The authors consider the disputed questions of the coordination of the actinides when carbamoyl compounds are used and they consider whether an effect of anomalous aryl strenghening exists in these systems. The compounds used are presented. The extraction of microquantities of americium and other actinides was performed from nitric acid media

  7. Method of purifying neutral organophosphorus extractants

    Science.gov (United States)

    Horwitz, E. Philip; Gatrone, Ralph C.; Chiarizia, Renato

    1988-01-01

    A method for removing acidic contaminants from neutral mono and bifunctional organophosphorous extractants by contacting the extractant with a macroporous cation exchange resin in the H.sup.+ state followed by contact with a macroporous anion exchange resin in the OH.sup.- state, whereupon the resins take up the acidic contaminants from the extractant, purifying the extractant and improving its extraction capability.

  8. Separation of rare earthes by extraction with neutral organophosphorus compounds in presence of complexones

    Science.gov (United States)

    Kopyrin, A. A.; Pyartman, A. K.; Keskinov, V. A.

    1999-01-01

    Physico-chemical and mathematical models of distribution of lanthanides(III) between watersalt solutions, containing salting-out agents, complexones (ethylendiaminetetraacetic (EDTA) and diethylen-thriaminepentaacetic acids (DTPA)) and neutral organophosphorus compounds (NOPC) are introduced. Examples of separation of rare earth elements concentrates with application of NOPC, complexones and ammonium nitrate is considered.

  9. Syntheses and structural characterization of mercury (II) coordination polymers with neutral bidentate flexible pyrazole-based ligands

    Science.gov (United States)

    Lalegani, Arash; Khaledi Sardashti, Mohammad; Salavati, Hossein; Asadi, Amin; Gajda, Roman; Woźniak, Krzysztof

    2016-03-01

    Mercury(II) coordination compounds [Hg(μ-bbd)(μ-SCN)4]n(1) and [Hg(bpp)(SCN)2] (2) were synthesized by using the neutral flexible bidentate N-donor ligands 1,4-bis(3,5-dimethypyrazol-1-yl)butane (bbd) and 1,3-bis(3,5-dimethylpyrazolyl)propane (bpp), NCS- ligand and appropriate mercury(II) salts. Compound 1 forms a polymeric network with moieties which are connected by SCN groups and the mercury ions present as HgN3S2 trigonal bipyramides. The crystal structure of 2 is build of monomers and the mercury(II) ion adopts an HgN2S2 tetrahedral geometry. In the complex 1, each bbd acts as bridging ligand connecting Hg(μ-SCN)4 ions, while in the complex 2, the bpp ligand is coordinated to an mercury(II) ion in a cyclic-bidentate fashion forming an eight-membered metallocyclic ring. Moreover, in the tetrahedral structure of 2, the neutral molecules form a 1D chain structure through the C-H···N hydrogen bonds, whereas in 1 no hydrogen bonds are observed. Coordination compounds 1 and 2 have been characterized by infrared spectroscopy, elemental analyses and single-crystal X-ray diffraction.

  10. Synergistic extraction of dioxoplutonium with 1-phenyl, 3-methyl, 4-benzoyl pyrazolone-5(HPMBP) and bi-dentate neutral donors (DBDECMP, DHDECMP and CMPO)

    International Nuclear Information System (INIS)

    Synergistic extraction of plutonyl ion was studied with HPMBP in combination with (bidentate neutral donors) DBDECMP, DHDECMP or CMPO using benzene as the diluent. The species extracted was established to be, PuO2(PMBP)2.S. Equilibrium constants (log Ks) of the organic phase addition reaction were found to follow the order of basicity (Kh) of the neutral donors. (author). 2 refs., 3 figs., 1 tab

  11. Solvent extraction of hexavalent plutonium with 1-phenyl, 3-methyl, 4-benzoyl pyrazolone-5 (HPMBP) and bi-dentate neutral donors (DBDECMP, DHDECMP and CMPO): synergism and thermodynamics

    International Nuclear Information System (INIS)

    Synergistic extraction of hexavalent plutonium was studied with HPMBP in combination with DBDECMP, DHDECMP or CMPO in benzene medium at various fixed temperatures. The equilibrium constants for the organic phase addition reaction (log Ks) were found to follow the trend in basicity of the neutral donors. Thermodynamic parameters were evaluated and these indicated that organic phase reaction is an addition and not a substitution reaction. Further, the bidentate donors act as monodentates. (orig.)

  12. Tricarbonylrhenium (I) complexes with neutral bidentate N-methyl-2-pyridinecarboamide as a precursor of therapeutic radiopharmaceuticals

    International Nuclear Information System (INIS)

    Coordination chemistry of technetium and rhenium attracts considerable interest due to the nuclear medicine applications of their radionuclides. 99mTc (γ-emitter) is the 'working horse' in diagnostic nuclear medicine, used in more than 80 percent of routine studies in this field. The β- -emitting rhenium isotopes, 186Re and 188Re, are used in radioimmuno therapy. The coordination behaviour of tricarbonylmetal(I) with chelating ligands, important for designing new metal-based radiopharmaceuticals, has been intensively studied by numerous authors. Particularly stable bonds have been found between the [M(CO)3]+ core (M Re, Tc) and aromatic nitrogen donor atoms of multidentate ligands. In this paper we report the complex formation (in mg quantities) of the tricarbonylrhenium(I) moiety with N-methyl-2-pyridinecarboamide (1), an analogue of the thio-compound recently studied. Ligand 1 was obtained according to the general procedure described in. The Re(I) precursor (2) was obtained. The investigated complex [ReI(CO)3LCl] (3), where L denotes 1, was obtained from 2, following the synthetic procedure worked out at the Paul Scherrer Institute. Molecular structure of the investigated complex 3 is presented. As it was expected, the ligand coordinates the cation bidentately, via the pyridine nitrogen and the oxygen atoms, and forms a five-membered ring with the metal centre. Stability of 3 towards oxidation was studied in the aerated 0.9% NaCl aqueous solution by registering its UV-Vis spectra as a function of time. Within one week no distinct change in the spectrum was detected. Infrared spectra of the ligand 1 and the complex 3 are shown. All the main bands of the 'fingerprint region' of the pyridinecarboamides (1300 / 700 cm-1) can be found in both spectra. The spectrum of 3 shows the typical pattern for a facial tricarbonyl moiety with bands at 2085, 1998 and 1879 cm-1 (CO ligands vibrations), and a very sharp signal of valency stretching of C=O in the amide group at

  13. Tricarbonyltechnetium(I) complexes with neutral bidentate ligands: n-methyl-2-pyridinecarboamide and n-methyl-2-pyridinecarbothioamide

    International Nuclear Information System (INIS)

    These thermodynamically stable and kinetically inert 99mTc chelates are good candidates for radiopharmaceuticals or their precursors. The aim of the present work is to select ligands that form very stable tricarbonyl complexes of technetium(I), and after further functionalization can be precursors for radiopharmaceuticals of the second generation. Two kinds of [Tc(CO)3LB] complexes were obtained and studied, where L is a neutral chelating ligand with either N,S donor atoms, N-methyl-2-pyridinecarbothioamide, LNS, or its analog with N,O donor atoms, N-methyl-2-pyridinecarboamide, LNO, while B is a monovalent anion or H2O. The complexes were prepared both with 99mTc at n.c.a. level (B=OH- or H2O) and with 99Tc in mg quantities (B=Cl-). The 99mTc complexes were investigated by HPLC and those of 99Tc - by IR measurements. Structural and hydrolytic properties of the obtained species are discussed

  14. Organophosphorus poisoning (acute)

    OpenAIRE

    Eddleston, Michael; Singh, Surjit; Buckley, Nick

    2007-01-01

    Acetylcholinesterase inhibition by organophosphorus pesticides or nerve gases 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.

  15. Organophosphorus poisoning (acute)

    OpenAIRE

    Blain, Peter G

    2011-01-01

    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.

  16. Nano-Intercalated Organophosphorus-Hydrolyzing Enzymes in Organophosphorus Antagonism

    OpenAIRE

    Petrikovics Ilona; Wales, Melinda E.; Budai Marianna; Yu, Jorn C. C.; Szilasi Mária

    2011-01-01

    A dendritic poly(2-alkyloxazoline)-based polymer was studied as a new carrier system for the organophosphorus-hydrolyzing recombinant enzymes, organophosphorus acid anhydrolase and organophosphorus hydrolase. Paraoxon (PO) and diisopropylfluorophosphate (DFP) were used as model organophosphorus compounds. Changes in plasma cholinesterase activity were monitored. The cholinesterase activity was proportional to the concentrations of DFP or PO. Plasma cholinesterase activity was higher in animal...

  17. The organophosphorus extractants

    International Nuclear Information System (INIS)

    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, D2EHPA 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

  18. Highly Strained Organophosphorus Compounds

    NARCIS (Netherlands)

    Slootweg, J.C.

    2005-01-01

    In our research on small, strained organophosphorus ring systems we became interested in the synthesis and applications of species that are even more strained than the parent phosphirane, by introducing an exocyclic double bond (methylenephosphirane), and by cyclopropyl spirofusion to the edge (e.g

  19. Organophosphorus Compounds in Organic Electronics.

    Science.gov (United States)

    Shameem, Muhammad Anwar; Orthaber, Andreas

    2016-07-25

    This Minireview describes recent advances of organophosphorus compounds as opto-electronic materials in the field of organic electronics. The progress of (hetero-) phospholes, unsaturated phosphanes, and trivalent and pentavalent phosphanes since 2010 is covered. The described applications of organophosphorus materials range from single molecule sensors, field effect transistors, organic light emitting diodes, to polymeric materials for organic photovoltaic applications. PMID:27276233

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

    International Nuclear Information System (INIS)

    The extraction of Ce (III) from aqueous solutions containing Al (NO3)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 (Kex) 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 Kd = (KexCMP [CMP]3 + KexCMPO [CMPO]3) [NO3-]3 by using these extraction constants. The extraction rate was found to be controlled by diffusion of Ce-complex [Ce(NO3)3 (CMPO)3 or Ce(NO3)3 (CMP)3] through the gel. The diffusion coefficient (Ds) was inversely proportional to the viscosity of extractant (η) and represented by an expression similar to the Stokes-Einstein equation, Dsη/T = constant. A decrease in the viscosity of extractant was effective for increasing the extraction rate. (author)

  1. Six-coordinate uranium complexes featuring a bidentate anilide ligand

    Energy Technology Data Exchange (ETDEWEB)

    Fox, A.R.; Silvia, J.S.; Townsend, E.M.; Cummins, Ch.C. [Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA (United States)

    2010-06-15

    The synthesis of a new bidentate anilide ligand and four uranium amide complexes utilizing the ligand are reported. The secondary aniline HN[R]Ar{sub Met} (R = C(CD{sub 3}){sub 2}CH{sub 3}, Ar{sub Met} = 2-NMe{sub 2}-5-MeC{sub 6}H{sub 3}) is prepared by condensation of H{sub 2}NAr{sub Met} and acetone-d6 followed by alkylation of the resulting imine with MeLi. The ligand precursors (Et{sub 2}O)Li(N[R]Ar{sub Met}) and K(N[R]Ar{sub Met}) are prepared through deprotonation of HN[R]Ar{sub Met} with n-BuLi and KH, respectively. Treatment of UI{sub 3}(THF){sub 4} with (Et{sub 2}O)Li(N[R]Ar{sub Met}) (2 equiv) provides the uranium(III) -ate complex Li[I{sub 2}U(N[R]Ar{sub Met}){sub 2}] (Li[1]), while treatment of UI{sub 3} with three equiv. of K(N[R]Ar{sub Met}) provides the neutral uranium(III) complex U(N[R]Ar{sub Met}){sub 3} (2). Both uranium(III) complexes are susceptible to 1e oxidation, as is demonstrated by the syntheses of the uranium(IV) derivatives I{sub 2}U(N[R]Ar{sub Met}){sub 2} (1) and [U(N[R]Ar{sub Met}){sub 3}][OTf] ([2][OTf]; OTf=CF{sub 3}SO{sub 3}). The spectroscopic and X-ray structural characterization of all four uranium complexes is described. The structures of 2 and [2][OTf] exhibit a large degree of steric pressure about the uranium center, effectively preventing the [2]{sup +} ion from achieving a seven-coordinate structure. (authors)

  2. Identification tree based on fragmentation rules for structure elucidation of organophosphorus esters by electrospray mass spectrometry.

    Science.gov (United States)

    Schwarzenberg, Adrián; Ichou, Farid; Cole, Richard B; Machuron-Mandard, Xavier; Junot, Christophe; Lesage, Denis; Tabet, Jean-Claude

    2013-05-01

    Organophosphorus compounds have played important roles as pesticides, chemical warfare agents and extractors of radioactive material. Structural elucidation of phosphonates poses a particular challenge because their initial forms can be hydrolyzed, thus, degradation products may predominate in samples acquired in the field. The analysis of non-volatile organophosphorus compounds and their degradation products is possible using electrospray tandem mass spectrometry ESI-MS/MS. Here, we present a generic strategy that allows the unambiguous identification of substituents for two families of organophosphorus compounds: the phosphonates and phosphates. General fragmentation rules were deduced based on the study of decomposition pathways of 55 organophosphorus esters, including examples found in the literature. Multistage MS (MS(n)) experiments at high resolution in a hybrid mass spectrometer provide accurate mass measurements, whereas collision-induced dissociation experiments in a triple quadrupole give access to small fragment ions. The creation of a specific nomenclature for each possible structure of organophosphorus compound, depending on the alkyl side chain linked to the oxygen, was achieved by applying these fragmentation rules. This led to the creation of an 'identification tree' based upon the unique consecutive decomposition pathways uncovered for each individual compound. Hence, seven structural motifs were created that orient an unequivocal identification using the 'identification tree'. Despite the similar structures of the ensemble of phosphate and phosphonate esters, distinct identifications based upon characteristic neutral losses and diagnostic fragment ions were possible in all cases. PMID:23674282

  3. Organopalladium complexes with bidentate phosphorus and nitrogen containing ligands

    NARCIS (Netherlands)

    Koten, G. van; Graaf, W. de; Harder, Sjoerd; Boersma, J.; Kanters, J.A.

    1988-01-01

    Organopalladium complexes containing the potentially P, N-bidentate ligands o-diphenylphosphino-N,N-dimethylbenzylamine (PN) and o-diphenylphosphino-@a-methyl-N,N-dimethylbenzylamine (PN}*{) have been studied. The palladium(0) complexes Pd(P@?N){3} (P@?N = PN or PN}*{) have been prepared: the ligand

  4. Mixed ligand oxovanadium(IV) complexes with salicylic acid and N,N-bidentate ligands

    International Nuclear Information System (INIS)

    Two mixed-ligand oxovanadium(IV) complexes VO(A)(B) [where H2A=salicylic acid and B=2,2'-bipyridine or 1,10-phenanthroline (hereafter, bipy and phen respectively)] have been synthesized and characterized by magnetic moment and spectral (IR, UV/VIS and EPR) data. The A2- ion acts as a bidentate dinegative ligand while B ligands acts as a neutral bidentate. The magnetic susceptibility values indicate the existence of a small amount of antiferromagnetic interaction. The vanadium atoms in the complexes are hexacoordinated and the coordination sphere is of the type [VO(OO)(NN)], where O atoms are of oxo, carboxylic and phenolic type and N atoms are of pyridine type. The sixth coordination site is occupied by phenolic oxygen of the neighbouring molecule forming a bridge. The vv=o confirms the hexacoordination. All the complexes have dxy1 type axial EPR spectra and they exhibit two ligand field transitions at 740 and 440 nm. (author)

  5. Extraction of neptunium and plutonium by bi- and polydentate organophosphorus compounds

    International Nuclear Information System (INIS)

    The extraction of neptunium(IV) and plutonium(IV) by six bidentate organophosphorus compounds (diphosphine dioxides, carbamoylphosphoryl compounds) and two tridentate compounds was studied. It was shown that on transition from tetraalkyl- to tetraarylmethylenediphosphine dioxide, an apparent aryl strengthening of the complexes is observed: The distribution coefficients of Np(IV) and Pu(IV) increase, and the extraction constants decrease. A similar phenomenon is observed during the extraction of Np(IV) in the series of octylphenyl-ditolyl-carbamoyl-phosphine oxide. For the tridentate extractants studied, an inherent anomalous aryl strengthening is observed when the methyl substituent is replaced by phenyl (both the distribution coefficients and the extraction constants increase). The extraction of neptunium(IV) and plutonium(IV) increases in the series of carbamoylmethyl phosphonate-phosphinate-phosphine oxide. The quantitative characteristics of the equilibria were found

  6. 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.

    2008-01-01

    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 dela

  7. Catalytic hydrolysis for the degradation of organophosphorus pesticides in water

    International Nuclear Information System (INIS)

    The kinetic studies of catalytic hydrolysis revealed that the concentration of two kinds of organophosphorus pesticides (omethoate and methidathion) in solution apparently decays according to the second order reaction. It was found that the rate constant value was highest at strong acidic conditions and it continued to decrease as the pH of the solution was increased. At basic conditions the rate constant value decreased to minimum. Manganese dioxide under acidic conditions converted into Mn/sup 2+/ ions and then these ions in water form hexaaquomanganese (II) ion. This hexaaquomanganese (II ion then adsorbed itself on the S or O atom of the organophosphorus compound and thus weakens the bond between P-S. This reaction facilitated the attack of H/sub 2/O or OH/sup -/ ion and thus enhanced the efficiency of hydrolysis. It was studied that methidathion hydrolyzed more efficiently than omethoate The rate constants of catalytic hydrolysis were increased with increasing the amount of MnO/sub 2/. It was found that the pesticides had undergone adsorption on catalyst in the first few minutes and there was the rapid drop of total phosphorus concentration. The decrease of total phosphorus adsorption with increasing pH was also observed. After the addition of alkaline earth metal cations (Ca/sup 2+/ and Mg/sup 2+/) along with magnesium, the enhancement in the efficiency of hydrolysis at near neutral conditions occurred. (author)

  8. IMPROVED SILICA GEL CLEANUP METHOD FOR ORGANOPHOSPHORUS PESTICIDES

    Science.gov (United States)

    Quantitative recovery of some organophosphorus pesticide residues has not been possible with existing silica gel-cleanup procedures. The authors have developed a modification that permits quantitative recovery of all organophosphorus pesticides tested, except those with a carbama...

  9. EFFECT OF ORGANOPHOSPHORUS FLAME RETARDANTS ON NEURONAL DEVELOPMENT IN VITRO

    Science.gov (United States)

    The increased use of organophosphorus compounds as alternatives to brominated flame retardants (BFRs) has led to widespread human exposure, There is, however, limited information on their potential health effects. This study compared the effects of nii ne organophosphorus flame...

  10. Morbidity in newborns exposed to organophosphorus pesticides

    Directory of Open Access Journals (Sweden)

    Đorđević Momčilo

    2010-01-01

    Full Text Available Introduction. Insecticides are toxines by which we destroy harmful insects. The most frequent insecticides which are used today are organophosphorus pesticides. This group of compounds make substances whose activity mechanism is based on the inhibition of acetylcho­linesterase in nerve synapsis, thus producing holynergic syndrome, resulting from the accumulation of acetylcholine which developed due to the absence of decomposition under the influence of cholinesterase. In the clinical picture of acute toxication by cholinesterase inhibitors there is a clear difference between muscarinic and nicotine effects. The basic aim of the study was to establish the effects of organophosphorus pesticides present in blood and breast milk of mothers on newborns morbidity. Material and methods. The study group consisted of 18 newborns whose mothers had isolated organophosphorus pesticides in their blood and breast­milk on the third day after delivery, and the control group consisted of 84 newborns whose mothers did not have isolated organophosphorus pesticides in their blood and breastmilk. Results. Morbidity is three times greater, often in combination with some disorders of the central nervous system, and the relative risk for its appearance is eight time greater in newborns exposed to organophosphorus pesticides. Disscusion. Disorders that appear in newborns exposed to pesticides are mutagenic, cancerogenic and neurotoxic and some agenses could disturb the immune system which is reflected in morbidity increase, primarly of the central nervous system. Conclusion. The presence of organophosphorus pesticides in blood and breast milk has negative effects on newborns. In addition to acetylcho­linesterase inhibition, organophosphorus pesticides react by means of other mechanisms as well.

  11. Lysophospholipase inhibition by organophosphorus toxicants

    International Nuclear Information System (INIS)

    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 (r2 = 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

  12. Organophosphorus and carbamate insecticide poisoning.

    Science.gov (United States)

    Vale, Allister; Lotti, Marcello

    2015-01-01

    Both organophosphorus (OP) and carbamate insecticides inhibit acetylcholinesterase (AChE), which results in accumulation of acetylcholine (ACh) at autonomic and some central synapses and at autonomic postganglionic and neuromuscular junctions. As a consequence, ACh binds to, and stimulates, muscarinic and nicotinic receptors, thereby producing characteristic features. With OP insecticides (but not carbamates), "aging" may also occur by partial dealkylation of the serine group at the active site of AChE; recovery of AChE activity requires synthesis of new enzyme in the liver. Relapse after apparent resolution of cholinergic symptoms has been reported with OP insecticides and is termed the intermediate syndrome. This involves the onset of muscle paralysis affecting particularly upper-limb muscles, neck flexors, and cranial nerves some 24-96 hours after OP exposure and is often associated with the development of respiratory failure. OP-induced delayed neuropathy results from phosphorylation and subsequent aging of at least 70% of neuropathy target esterase. Cramping muscle pain in the lower limbs, distal numbness, and paresthesiae are followed by progressive weakness, depression of deep tendon reflexes in the lower limbs and, in severe cases, in the upper limbs. The therapeutic combination of oxime, atropine, and diazepam is well established experimentally in the treatment of OP pesticide poisoning. However, there has been controversy as to whether oximes improve morbidity and mortality in human poisoning. The explanation may be that the solvents in many formulations are primarily responsible for the high morbidity and mortality; oximes would not be expected to reduce toxicity in these circumstances. even if given in appropriate dose. PMID:26563788

  13. Phthalates and organophosphorus compounds in indoor dust

    Czech Academy of Sciences Publication Activity Database

    Hwang, H.; Lee, S.; Lim, J.; Joen, S.; Mikuška, Pavel; Kumar, A.

    Pensacola: Society of Environmental Toxicology and Chemistry (SETAC), 2010. s. 360. ISBN 1087-8939. [SETAC North America Annual Meeting /31./. 07.11.2010-11.11.2010, Portland] Institutional research plan: CEZ:AV0Z40310501 Keywords : indoor floor dust * phthalates * organophosphorus compounds Subject RIV: CB - Analytical Chemistry, Separation

  14. CUMULATIVE EFFECTS OF ORGANOPHOSPHORUS OR CARBAMATE PESTICIDES.

    Science.gov (United States)

    This book chapter strives to summarize the body of literature exploring the toxic interaction of organophosphorus and carbamate pesticides in mixtures. This review represents one of the only reviews of the subject that has been published within the last 20 years. Specifically, th...

  15. Interactions of cyclodextrins and their derivatives with toxic organophosphorus compounds

    Science.gov (United States)

    Letort, Sophie; Balieu, Sébastien; Erb, William; Gouhier, Géraldine

    2016-01-01

    Summary The aim of this review is to provide an update on the current use of cyclodextrins against organophosphorus compound intoxications. Organophosphorus pesticides and nerve agents play a determinant role in the inhibition of cholinesterases. The cyclic structure of cyclodextrins and their toroidal shape are perfectly suitable to design new chemical scavengers able to trap and hydrolyze the organophosphorus compounds before they reach their biological target. PMID:26977180

  16. Synergistic extraction equilibrium of lanthanoids(III) with 2-thenoyltrifluoroacetone and nitrogen-containing bidentate ligands, ethylenediamine derivatives

    International Nuclear Information System (INIS)

    The synergistic extraction of lanthanoids(III), Ln(III), i.e., La, Sm, Tb, Tm and Lu, using 2-thenoyltrifluoroacetone (Htta) and nitrogen-containing neutral bidentate ligands (S), i.e., three ethylenediamine derivatives, such as N,N'-dimethylethylenediamine (dmen), N,N'-diethylethylenediamine (deen) and cis-1,2-cyclohexanediamine (chda), was studied in the benzene and aqueous system. The synergistic enhancement in these extraction systems was mainly attributed to the formation of an adduct, Ln(tta)3S, in the benzene phase. The variation of the adduct formation constants (βS,1) was discussed with the basicity of ligands and structure hindrance around the metal ion

  17. Chiral P,N-bidentate ligands in coordination chemistry and organic catalysis involving rhodium and palladium

    International Nuclear Information System (INIS)

    Published data on the synthesis of rhodium and palladium complexes with optically active P,N-bidentate ligands and their applications in homogeneous asymmetric catalysis are summarised and discussed. The effect of the nature of the P,N-bidentate compounds on the structure of the metal complexes and on enantioselectivity in catalysis is examined. Allylic substitution, cross-coupling, hydroboration and hydrosilylation catalysed by Rh or Pd complexes with optically active P,N-bidentate ligands are considered. The prospects for the development of this field of chemistry are demonstrated. The bibliography includes 186 references.

  18. Aromaticity as stabilizing element in the bidentate activation for the catalytic reduction of carbon dioxide.

    Science.gov (United States)

    Lu, Zhenpin; Hausmann, Heike; Becker, Sabine; Wegner, Hermann A

    2015-04-29

    A new transition-metal-free mode for the catalytic reduction of carbon dioxide via bidentate interaction has been developed. In the presence of Li2[1,2-C6H4(BH3)2], CO2 can be selectively transformed to either methane or methanol, depending on the reducing agent. The bidentate nature of binding is supported by X-ray analysis of an intermediate analogue, which experiences special stabilization due to aromatic character in the bidentate interaction. Kinetic studies revealed a first-order reaction rate. The transformation can be conducted without any solvent. PMID:25871326

  19. [Today's threat of use of organophosphorus compounds].

    Science.gov (United States)

    Sokołowski, Rafał; Płusa, Tadeusz

    2015-09-01

    Organophosphates are stable cholinesterases inhibitors (AChE). Inhibition of AChE activity leads to the accumulation of large amounts of acetylcholine and hyperactivity of the cholinergic system by stimulating acetylcholine receptors - muscarinic and nicotinic. This group included tabun, sarin, soman and VX gases. Exposure to gaseous form causes symptoms within a few seconds of exposure. This depends on the gas concentration in the atmosphere. The most sensitive organ is the eyes and the respiratory system. Severe poisoning are characterized by the immediate loss of consciousness with convulsions. Therapeutic management of acute poisoning organophosphorus compounds boils down to treating symptomatic and supportive vital functions. Monitoring of cardiovascular, respiratory and renal failure in intensive care gives only guarantee the effective treatment of poisoning. Properties toxic organophosphorus compounds also are of interest to terrorist groups. PMID:26449583

  20. Morbidity in newborns exposed to organophosphorus pesticides

    OpenAIRE

    Đorđević Momčilo; Sazdanović Predrag; Đorđević Gordana; Jovanović Božidar

    2010-01-01

    Introduction. Insecticides are toxines by which we destroy harmful insects. The most frequent insecticides which are used today are organophosphorus pesticides. This group of compounds make substances whose activity mechanism is based on the inhibition of acetylcho­linesterase in nerve synapsis, thus producing holynergic syndrome, resulting from the accumulation of acetylcholine which developed due to the absence of decomposition under the influence of cholinesterase. In the clinical pi...

  1. Effects of organophosphorus insecticides on sage grouse in southeastern Idaho

    Science.gov (United States)

    Blus, L.J.; Staley, C.S.; Henny, C.J.; Pendleton, G.W.; Craig, T.H.; Craig, E.H.; Halford, D.K.

    1989-01-01

    Unverified reports indicated die-offs of sage grouse have occurred since the 1970s in southeastern Idaho. Some verification that organophosphorus insecticides were involved was obtained in 1981 and 1983. A radio telemetry study indicated that dimethoate was responsible for most mortality. Methamidophos also acounted for mortality. Sage grouse populations may be adversely affected by organophosphorus insecticides.

  2. Efforts toward treatments against aging of organophosphorus-inhibited acetylcholinesterase.

    Science.gov (United States)

    Zhuang, Qinggeng; Young, Amneh; Callam, Christopher S; McElroy, Craig A; Ekici, Özlem Dogan; Yoder, Ryan J; Hadad, Christopher M

    2016-06-01

    Aging is a dealkylation reaction of organophosphorus (OP)-inhibited acetylcholinesterase (AChE). Despite many studies to date, aged AChE cannot be reactivated directly by traditional pyridinium oximes. This review summarizes strategies that are potentially valuable in the treatment against aging in OP poisoning. Among them, retardation of aging seeks to lower the rate of aging through the use of AChE effectors. These drugs should be administered before AChE is completely aged. For postaging treatment, realkylation of aged AChE by appropriate alkylators may pave the way for oxime treatment by neutralizing the oxyanion at the active site of aged AChE. The other two strategies, upregulation of AChE expression and introduction of exogenous AChE, cannot resurrect aged AChE but may compensate for lowered active AChE levels by in situ production or external introduction of active AChE. Upregulation of AChE expression can be triggered by some peptides. Sources of exogenous AChE can be whole blood or purified AChE, either from human or nonhuman species. PMID:27327269

  3. New Genetic Constructs for Generation of Stable Therapeutic Antibodies to Organophosphorus Toxins in Methylotrophic Yeasts Pichia Pastoris.

    Science.gov (United States)

    Mokrushina, Yu A; Stepanova, A V; Bobik, T V; Smirnov, I V; Gabibov, A G

    2016-05-01

    We propose a new method of obtaining of stable Fab-fragments of antibodies in Pichia pastoris expression system. Recently, we obtained Fab-fragments of antibodies neutralizing organophosphorus toxins. However, high yield of the target products was not attained because of high level of proteolytic degradation. In the present study, we identified sites of proteolytic degradation in Fab-fragments and endogenous proteases performing degradation, which allowed obtaining optimized genetic constructs for expression of antibody heavy chains (IgGγ1) and kappa and lambda isotypes of light chains. Co-transformation of these vectors allowed obtaining Fab-fragments of antibodies to organophosphorus toxins without proteolytic degradation of the product. PMID:27270933

  4. Stimuli-responsive chromism in organophosphorus chemistry.

    Science.gov (United States)

    Reus, Christian; Baumgartner, Thomas

    2016-02-01

    Changes in color are one of the most obvious and easily followed responses that can be induced by an external stimulus. π-Conjugated organophosphorus compounds are on the rise to challenge established systems by opening up new and simple pathways to diversely modified optoelectronic properties--the main challenge for the development of new chromic materials. Relevant stimuli highlighted in this Frontier article include electronic current (electrochromism), light (photochromism), solvent polarity (solvatochromism), aggregation formation (aggregation induced emission, AIE), mechanical force (mechanochromism), temperature (thermochromism), organic solvent vapor (vapochromism), and pH (halochromism). PMID:26286166

  5. 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...

  6. Flame retardant cotton fabrics treated with organophosphorus polymer.

    Science.gov (United States)

    Abou-Okeil, A; El-Sawy, S M; Abdel-Mohdy, F A

    2013-02-15

    Organo-phosphorus compounds was prepared and applied onto cotton fabrics as flame retarding agent. methacryloloxyethylorthophoshor tetraethyl diamidate (MPD) was prepared and its structure was confirmed by IR, NMR and mass spectroscopy. Pyrovatex as commercial flame retardant was used for comparative study. Impregnation method was used as coating for the application of the organophosphorus compounds to cotton fabrics. The major factors affecting the reaction were studied. The results show that the prepared organophosphorus compound can be successfully used as flame retardant for cotton fabrics. PMID:23399290

  7. Chloramination of Organophosphorus Pesticides Found in Drinking Water Sources

    Science.gov (United States)

    The degradation of commonly detected organophosphorus (OP) pesticides, in drinking water sources, was investigated under simulated chloramination conditions. Due to monochloramine autodecomposition, it is difficult to observe the direct reaction of monochloramine with each OP pe...

  8. ORGANOPHOSPHORUS PESTICIDE DEGRADATION PATHWAYS DURING DRINKING WATER TREATMENT

    Science.gov (United States)

    The objective of this work was to investigate organophosphorus (OP) pesticide transformation pathways as a class in the presence of aqueous chlorine. Seven priority OP pesticides were examined for their reactivity with aqueous chlorine: chlorpyrifos (CP), parathion (PA), diazino...

  9. Mechanism of action of organophosphorus and carbamate insecticides.

    OpenAIRE

    Fukuto, T R

    1990-01-01

    Organophosphorus and carbamate insecticides are toxic to insects and mammals by virtue of their ability to inactivate the enzyme acetylcholinesterase. This review addresses the mechanism of inhibition of acetylcholinesterase by organophosphorus and carbamate esters, focusing on structural requirements necessary for anticholinesterase activity. The inhibition of acetylcholinesterase by these compounds is discussed in terms of reactivity and steric effects. The role of metabolic activation or d...

  10. Competitive reactions of organophosphorus radicals on coke surfaces.

    Science.gov (United States)

    Catak, Saron; Hemelsoet, Karen; Hermosilla, Laura; Waroquier, Michel; Van Speybroeck, Veronique

    2011-10-17

    The efficacy of organophosphorus radicals as anticoking agents was subjected to a computational study in which a representative set of radicals derived from industrially relevant organophosphorus additives was used to explore competitive reaction pathways on the graphene-like coke surface formed during thermal cracking. The aim was to investigate the nature of the competing reactions of different organophosphorus radicals on coke surfaces, and elucidate their mode of attack and inhibiting effect on the forming coke layer by use of contemporary computational methods. Density functional calculations on benzene and a larger polyaromatic hydrocarbon, namely, ovalene, showed that organophosphorus radicals have a high propensity to add to the periphery of the coke surface, inhibiting methyl radical induced hydrogen abstraction, which is known to be a key step in coke growth. Low addition barriers reported for a phosphatidyl radical suggest competitive aptitude against coke formation. Moreover, organophosphorus additives bearing aromatic substituents, which were shown to interact with the coke surface through dispersive π-π stacking interactions, are suggested to play a nontrivial role in hindering further stacking among coke surfaces. This may be the underlying rationale behind experimental observation of softer coke in the presence of organophosphorus radicals. The ultimate goal is to provide information that will be useful in building single-event microkinetic models. This study presents pertinent information on potential reactions that could be taken up in these models. PMID:21956815

  11. Limited Neutrality

    DEFF Research Database (Denmark)

    Nielsen, Morten Ebbe Juul

    2006-01-01

    Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."......Article Concerning the prospect of a kind of limited neutrality in place of the standard liberal egalitarian "neutrality of justification."...

  12. Profile of acute mixed organophosphorus poisoning.

    Science.gov (United States)

    Thunga, Girish; Sam, Kishore Gnana; Khera, Kanav; Xavier, Vidya; Verma, Murlidhar

    2009-06-01

    Organophosphorus (OP) pesticide self-poisoning is a major clinical and public health problem across much of rural Asia and responsible for two thirds of suicidal deaths. However, clinical reports or evidence for the management of mixed poisoning are lacking. Patients are often treated based on the type of symptoms they exhibit, and there are no specific guidelines available to treat mixed poisoning. In this case series, we report 3 acute OP poisoning cases with mixed poisons such as organochlorine, fungicide, copper sulfate, and kerosene. All 3 patients were treated successfully, with a greater focus on OP poisoning with pralidoxime and atropine infusion along with standard decontamination procedures. Because patients developed complications due to the concomitant poisons ingested, they were later treated symptomatically, and in one case, D-penicillamine was administered as antidote for copper poisoning. Mixed poisoning especially with OP compounds makes the diagnosis difficult because the clinical symptoms of OP predominate, whereas damage produced by other pesticides is late to develop and often neglected. Common treatment procedures are focused mainly on the OP poisoning ignoring the complications of other concomitant pesticides ingested. Treating physicians should be prepared and consider the possibility of mixed poisoning prevalent in that region before initiating therapy. PMID:19497478

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

    International Nuclear Information System (INIS)

    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)

  14. Synthesis and characterization of uranyl acetate complexes with some potentially bidentate ligands

    International Nuclear Information System (INIS)

    Complexes of uranyl acetate with three potentially bidentate ligands-nicotinic acid (NA), 2,2'-bipyridyl(2,2'-Bipy) and 4,4'-bipyridyl N,N'-dioxide (4,4'-BipyO2) have been synthesized and characterized on the basis of analytical data, electrical conductance, electronic and IR spectral studies. Uranyl acetate forms 1:1 complexes with 2,2'-Bipy and 4,4'-BipyO2 and a 1:2 complex with NA. It is shown that UO2(NA)2(CH3COO)2 and UO2(2,2'-Bipy)(CH3COO)2 have monomeric structures while UO2(4,4'-BipyO2)(CH3COO)2 has a polymeric chain structure. The acetate groups act as bidentate chelating ligands in these complexes. All the compounds studied are considered to have an overall coordination number eight around uranium(VI). (author). 16 refs

  15. Critical evaluation of some equilibrium constants involving organophosphorus extractants

    CERN Document Server

    Marcus, Y

    2013-01-01

    Critical Evaluation of Some Equilibrium Constants Involving Organophosphorus Extractants is a supplementary text to the compilation ""Equilibrium Constants of Liquid-Liquid Distribution Reactions (Introduction, and Part I: Organophosphorus Extractants).The book contains a number of well documented chemical reactions that are critically evaluated. The reactions evaluated comprise those from List 1 for which data are available. There are, however, a great variety of reactions that cannot be critically evaluated due to lack of experimental data and unverifiable results.Chemists will find this com

  16. Toxic action of organophosphorus compounds and esterase inhibition in houseflies

    NARCIS (Netherlands)

    Asperen, K. van

    1960-01-01

    The paper deals with investigations on the inhibition in vivo of the cholin-esterase and the aliesterase in houseflies poisoned by treatment with organophosphorus insecticides. The kinetics of the inhibition of esterases by DDVP, paraoxon and diazoxon in the presence and in the absence of substrate

  17. Respiratory Failure in Acute Organophosphorus Pesticide Self-Poisoning

    OpenAIRE

    Eddleston, Michael; Mohamed, Fahim; Davies, James OJ; Eyer, Peter; Worek, Franz; Sheriff, Mh Rezvi; Buckley, Nick A.

    2006-01-01

    Background: Acute organophosphorus (OP) pesticide poisoning is a major clinical problem in the developing world. Textbooks ascribe most deaths to respiratory failure occurring in one of two distinct clinical syndromes - acute cholinergic respiratory failure or the intermediate syndrome. The delayed failure appears to be due to respiratory muscle weakness, but its pathophysiology is not yet clear.

  18. 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.

  19. Sorption of triazine and organophosphorus pesticides on soil and biochar

    Science.gov (United States)

    Although a large number of reports are available on sorption and degradation of triazine and organophosphorus pesticides in soils, systematic studies are lacking to directly compare and predict the fate of agrochemicals having different susceptibilities for hydrolysis and other degradation pathways....

  20. Synthesis of novel organo-phosphorus C60 dimers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Carbon bridged organophosphorus C60 dimers were obtained by the reaction of aminome- thylenebisphosphonate anion with C60 and fully characterized by 1HNMR, 31PNMR, 13CNMR, FT- MALDI-MS, FT-IR, UV-Vis, DEPT and HMBC, and the dimeric compounds undergo hydrolysis by using TMSI.

  1. Bidentate forms of β-triketimines: syntheses, characterization and outstanding performance of enamine-diimine cobalt complexes in isoprene polymerization.

    Science.gov (United States)

    Alnajrani, Mohammed N; Mair, Francis S

    2016-06-21

    New cationic enamine-β-diimine cobalt complex [LCoBr·THF][BArF] () and its neutral analogue [LCoBr2] () where L = [(2,4,6-Me3-C6H2)NHCMe[double bond, length as m-dash]C{CMe[double bond, length as m-dash](N-2,4,6-Me3(C6H2))}2] and BArF(-) = [{3,5-(CF3)2C6H3}4B](-), were synthesised and then characterized by single-crystal X-ray diffraction, MALDI-MS, IR and elemental analysis. These complexes, the first examples reported where putatively tridentate β-triketimines prefer a bidentate coordination mode, were examined as catalysts for the polymerization of isoprene, activated by diethylaluminium chloride (DEAC) or ethylaluminium sesquichloride (EASC). The weakly coordinating BArF anion in strongly improved activity in comparison to . Both and produced polyisoprene of ca. 80% cis-1,4 and 20% 3,4 enchainment, with trace levels of trans-1,4 and no 1, 2 polymer. A kinetic study for both and demonstrated that the polymerization was first-order in monomer and that approximately 46% and 50% of cobalt formed active centres for and respectively. EASC was the most active of a range of organoaluminium compounds screened for both and . The resulting activities of up to 6 × 10(5) mol isoprene per mol Co per h are the highest yet recorded for catalysts selective for cis-1,4 enchained polyisoprene. PMID:27264840

  2. OH initiated heterogeneous degradation of organophosphorus compounds

    Science.gov (United States)

    Liggio, J.; Liu, Y.; Harner, T.; Jantunen, L.; Shoeib, M.; Li, S.

    2013-12-01

    Organophosphorus compounds (OPs) have been extensively used worldwide as flame retardants, plasticizers, antifoaming agents, and additives because of their favorable physicochemical characteristics. The global consumption of OPs is likely to greatly increase due to the phasing out of bromine-containing flame retardants (BFRs) with OPs identified as possible substitutes. In most applications, OPs easily leach out of the material into the environment via volatilization, abrasion, and dissolution and have been observed widely in atmospheric particles even in polar regions. However, little is known about their atmospheric fate. The Canadian Chemicals Management Plan (CMP) has targeted OP FRs for risk assessment, including assessing stability and atmospheric transport potential of OP FRs and other priority chemicals that are associated primarily with particles. In the current study, OH initiated heterogeneous reaction kinetics of tris(1,3-dichloro-2-propyl) phosphate (TDCPP), tris-2-ethylhexyl-phosphate (TEHP), tris-2-butoxyethyl-phosphate (TBEP), and tri-phenyl phosphate (TPhP) coated on (NH4)2SO4 were investigated using a photo-chemical flow tube which was coupled to an Aerosol Mass Spectrometer (AMS) and Proton Transfer Reaction Mass Spectrometer (PTR-MS). second-order rate constants (k2) for the heterogeneous loss of TPhP, TEHP and TDCPP were (2.07×0.19)×10-12, (2.69×0.63)×10-12 and (9.22×0.92)×10-13 cm3 molecule-1 s-1, respectively, from which approximate atmospheric lifetimes were estimated to be 5.6 (5.2-6.0), 4.3 (3.5-5.6), and 12.6 (11.4-14.0) days. These results represent the first reported estimates of heterogeneous rate constants for these species, and suggest that particle bound OPEs will be highly persistent in the atmosphere, supporting the assumption that OPEs can undergo medium or long-range transport, as proposed on the basis of field measurements.

  3. 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.

  4. Syntheses, magnetic and spectral studies on polystyrene supported coordination compounds of bidentate and tetradentate Schiff bases

    Indian Academy of Sciences (India)

    D Kumar; P K Gupta; A Syamal

    2005-05-01

    The reaction of aminomethylated polystyrene (PSCH2-NH2) and 2-hydroxyacetanilide in DMF results in the formation of polystyrene-anchored monobasic bidentate Schiff base, PSCH2-LH (I). On the other hand, the reaction of chloromethylated polystyrene (PSCH2-Cl), 3-formylsalicylic acid, ethylenediamine and acetylacetone in DMF in presence of ethyl acetate (EA) and triethylamine (TEA) produces another polystyrene-anchored dibasic tetradentate Schiff base, PSCH2-L'H2 (II). Both I and II react with a number of di-, tri- and hexavalent metal ions like Co, Ni, Cu, Zn and Cd to form polystyreneanchored coordination compounds, and these have been characterized and discussed.

  5. 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.

  6. Large Enhancement of Optical Nonlinearities of New Organophosphorus Fullerene Derivative

    Institute of Scientific and Technical Information of China (English)

    刘智波; 田建国; 臧维平; 周文远; 张春平; 郑建禺; 周迎春; 徐华

    2003-01-01

    Optical nonlinearities of new organophosphorus fullerene derivative were determined by the Z-scan method with a pulsed Q-switch Nd:YAG laser at 532nm. The experimental results demonstrated that the derivative has much larger excited-states nonlinear absorption and nonlinear refraction than C60. A five-level model was utilized to fit the experimental data, and a good agreement is reached. Some parameters such as excited-state absorption cross and refraction cross were obtained. To our knowledge, the excited-state cross section of new organophosphorus fullerene derivative and its effective ratio to the ground-state cross section are the largest values among the fullerene derivatives reported to date.

  7. 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. PMID:25672037

  8. Particulate matter formation from photochemical degradation of organophosphorus pesticides

    Science.gov (United States)

    Borrás, E.; Ródenas, M.; Vera, T.; Muñoz, A.

    2015-12-01

    Several experiments were performed in the European Photo-reactor - EUPHORE - for studying aerosol formation from organophosphorus pesticides such as diazinon, chlorpyrifos, chlorpyrifos-methyl and pirimiphos-methyl. The mass concentration yields obtained (Y) were in the range 5 - 44% for the photo-oxidation reactions in the presence and the absence of NOx. These results confirm the importance of studying pesticides as significant precursors of atmospheric particulate matter due to the serious risks associated to them. The studies based on the use of EUPHORE photoreactor provide useful data about atmospheric degradation processes of organophosphorus pesticides to the atmosphere. Knowledge of the specific degradation products, including the formation of secondary particulate matter, could complete the assessment of their potential impact, since the formation of those degradation products plays a significant role in the atmospheric chemistry, global climate change, radiative force, and are related to health effects.

  9. The application of green chemistry methods in organophosphorus synthesis

    International Nuclear Information System (INIS)

    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.

  10. Have Regulatory Efforts to Reduce Organophosphorus Insecticide Exposures Been Effective?

    OpenAIRE

    Clune, Alison L.; Ryan, P. Barry; Barr, Dana Boyd

    2012-01-01

    Background: The Food Quality Protection Act (FQPA) was signed into law in 1996 to strengthen the regulation of pesticide tolerances in food. Organophosphorus (OP) insecticides were the first group of pesticides reviewed by the U.S. Environmental Protection Agency (EPA) under the new law. Objective: Our goal was to determine whether urinary concentrations of dialkylphosphate (DAP) metabolites of OP pesticides declined between the National Health and Nutrition Examination Survey (NHANES) III an...

  11. Acetylcholinesterase Biosensors for Electrochemical Detection of Organophosphorus Compounds: A Review

    OpenAIRE

    Vikas Dhull; Anjum Gahlaut; Neeraj Dilbaghi; Vikas Hooda

    2013-01-01

    The exponentially growing population, with limited resources, has exerted an intense pressure on the agriculture sector. In order to achieve high productivity the use of pesticide has increased up to many folds. These pesticides contain organophosphorus (OP) toxic compounds which interfere with the proper functioning of enzyme acetylcholinesterase (AChE) and finally affect the central nervous system (CNS). So, there is a need for routine, continuous, on spot detection of OP compounds which ar...

  12. Presence of organophosphorus pesticide oxygen analogs in air samples

    OpenAIRE

    Armstrong, Jenna L.; Fenske, Richard A; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

    2013-01-01

    A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and lab...

  13. Prognostic Significance of Various Biochemical Parameters in Acute Organophosphorus Poisoning

    OpenAIRE

    Sumathi, M. E.; Kumar, S. Harish; Shashidhar, K N; Takkalaki, Nandini

    2014-01-01

    Background: Organophosphorus (OP) compounds are a heterogeneous group of insecticides widely used in agricultural industry. These OP compounds are likely to have more adverse effects in developing countries like India due to its easy availability and less awareness which results in high morbidity and mortality. Aims and objectives: 1. To estimate plasma cholinesterase, amylase, lipase and, creatine phosphokinase (CPK) in acute OP poisoning. 2. To correlate these biochemical parameters with pl...

  14. The application of green chemistry methods in organophosphorus synthesis

    Science.gov (United States)

    Odinets, Irina L.; Matveeva, E. V.

    2012-03-01

    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.

  15. 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.

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

    International Nuclear Information System (INIS)

    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

  17. Wildlife mortality attributed to organophosphorus and carbamate pesticides

    Science.gov (United States)

    Glaser, L.C.

    1995-01-01

    Organophosphorus (OP) and carbamate pesticides are used widely in agricultural and residential applications as insecticides, herbicides, fungicities. and rodenticides. This family of chemicals replaced the organochlorine pesticides banned for use in the United States in the 1970's. Unlike organochlorine pesticides, which are long-lived in the environment and cause biological damage when they accumulate in an organism's system over time. OP and carbamate pesticides are short-lived in the environment and fast-acting on their 'target pest.' Direct mortality of wildlife from organochlorine pesticides was uncommon (Hayes and Wayland 1975): however, mortality is the primary documented effect on wildlife from OP and carbamate pesticides (Grue et al. 1983). Organophosphorus and carbamate pesticide toxicity is not specific to a target 'pest,' and lethal effects are seen in nontarget organisms: birds appear to be the most sensitive class of animals affected by these pesticides. Organophosphorus and carbamate pesticides primainly affect the nervous system by inhibiting acetylcholinesterase (AChE) enzyme activity. This enzyme's main function in the nervous system is to break down the neurotransmitter acetylcholine. When AChE is altered by OP and carbamate pesticides, it cannot perform this breakdown function and acetylcholine accumulates. Acetylcholine accumulation increases nerve impulse transmission and leads to nerve exhaustion and. ultimately, failure of the nervous system. When the nervous system fails, muscles do not receive the electrical input they require to move. The respiratory muscles are the most critical muscle group affected, and respiratory paralysis is often the immediate cause of death.

  18. Detection of organophosphorus compound based on a sol-gel silica planar waveguide doped with a green fluorescent protein and an organophosphorus hydrolase

    Science.gov (United States)

    Enami, Y.; Tsuchiya, K.; Suye, S.

    2011-06-01

    In this letter, the authors report the real-time detection of an organophosphorus compound using a sol-gel silica planar waveguide doped with a green fluorescent protein and an organophosphorus hydrolase on a yeast-cell surface display. The waveguide was pumped at 488 nm, and it emitted green fluorescence at the far field. The green fluorescent light at 550 nm changed by 50% from the original power 1 min after application of the organophosphorus compound. The results enable the real-time detection of sarin and other biochemicals by using an in-line fiber sensor network.

  19. Influence of N-P base fiber reactive organophosphorus flame retardant on cotton thermal behavior

    Science.gov (United States)

    An efficient synergistic effect between a nitrogen-containing organophosphorus compound in the presence of a catalytic amount of chlorine is proposed based on the cyanuric chloride-linked organophosphorus flame retardant, tetraethyl-2,2'-(6-chloro-1,3,5-triazine-2,4-diyl)bis(azanediyl)bis(ethane-2,1...

  20. Antiproliferative activity of ruthenium(ii) arene complexes with mono- and bidentate pyridine-based ligands.

    Science.gov (United States)

    Richter, Stefan; Singh, Sushma; Draca, Dijana; Kate, Anup; Kumbhar, Anupa; Kumbhar, Avinash S; Maksimovic-Ivanic, Danijela; Mijatovic, Sanja; Lönnecke, Peter; Hey-Hawkins, Evamarie

    2016-08-16

    A series of Ru(II) arene complexes of mono- and bidentate N-donor ligands with carboxyl or ester groups and chlorido ancillary ligands were synthesised and structurally characterised. The complexes have a distorted tetrahedral piano-stool geometry. The binding interaction was studied with calf thymus DNA (CT-DNA) by absorption titration, viscosity measurement, thermal melting, circular dichroism, ethidium bromide displacement assay and DNA cleavage of plasmid DNA (pBR322), investigated by gel electrophoresis. The dichlorido complexes bind covalently to DNA in the dark, similar to cisplatin, while the monochlorido complexes bind covalently on irradiation, similar to cisplatin analogues. The compounds are selectively cytotoxic against several tumour cell lines and show specific nonlinear correlation between dose and activity. This phenomenon is closely related to their potential to act preferentially as inhibitors of cell division. PMID:27264161

  1. Imino sulfinamidines: synthesis and coordination chemistry of a novel class of chiral bidentate ligands.

    Science.gov (United States)

    Barrett, Anthony G M; Gray, Andrew A; Hill, Michael S; Hitchcock, Peter B; Procopiou, Panayiotis A; White, Andrew J P

    2006-04-17

    The new imino sulfinamidine ligand PhS(NHt-Bu)=NC(Me)=N(C6H3-2,6-iPr2), LH (11) was synthesized from N-(2,6-diisopropylphenyl)acetamidine (9) and N-tert-butyl phenylsulfinimidoyl chloride (10). Reaction of LH (11) with ZnEt2 or AlMe3 gave the complexes LZnEt (12) and LAlMe2 (13), respectively. The structures of 12 and 13 were determined by X-ray diffraction and were shown to contain L as a kappa2-N1,N5 bidentate ligand in a six-membered chelate. Formation of the magnesium complex (LMgN(TMS)2 x L2Mg) (14) from 11, MgI2, and KN(SiMe3)2 highlighted a secondary coordination mode of L, binding through the sulfinamidine nitrogens in a four-membered chelate. PMID:16602794

  2. Ruthenium(II) complexes containing bidentate Schiff bases and triphenylphosphine or triphenylarsine

    Indian Academy of Sciences (India)

    P Viswanathamurthi; R Karvembu; V Tharaneeswaran; K Natarajan

    2005-05-01

    Reactions of ruthenium(II) complexes [RuHX(CO)(EPh3)2(B)] (X = H or Cl; B = EPh3, pyridine (py) or piperidine (pip); E = P or As) with bidentate Schiff base ligands derived by condensing - hydroxyacetophenone with aniline, - or -methylaniline have been carried out. The products were characterized by analytical, IR, electronic and 1H-NMR spectral studies and are formulated as [Ru(X)(CO) (L)(EPh3)(B)] (L = Schiff base anion; X = H or Cl; B = EPh3, py or pip; E = P or As). An octahedral structure has been tentatively proposed for the new complexes. The new complexes were tested for their catalytic activities in the oxidation of benzyl alcohol to benzaldehyde.

  3. 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.

  4. Versatility of bidentate aniline derivatives as ligands for rhenium (V) and technetium (V)

    International Nuclear Information System (INIS)

    The versatility of aniline derivatives as ligands for Re(V) and Tc(V) has been investigated. The reaction of (n-Bu4N)[MOCl4](M=Re, Tc) with 1,2-diaminobenzene (H2dab) and 2,3-diaminopyridine (H2dap) gave the products (Bu4N)[MO(dab)2] (1) and [MO(dapH)2]Cl (2) respectively. Both chelates in 1 and 2 are coordinated as diamides; however, in 2 the pyridine nitrogens of dapH are protonated. With trans-[ReOCl3(PPh3)2] as a starting complex, a number of products were isolated, depending on the reaction conditions. For example, with 3-hydroxy-1,2-diamino-benzene (H2dab-OH) under N2, [Re(dab-OH)Cl3(PPh3)2] (3) was produced, in which dab-OH substituted the oxo group and is coordinated as a monodentate imide. With 3-nitro-1,2-diaminobenzene (H2dab-NO2), the oxo-free complex [ReCl(PPh3)(dab-NO2)2] (4) was obtained, with bidentate diamido coordination of each chelate. Using trans-[ReO2(py)4]Cl as a starting complex, complexes of the type [Re(sbqdi-OH)3]Cl (5) and cis-[ReO2(Hdab)(py)2] (6) were isolated, where sbqdi-OH coordinates as the monoanionic semibenzoquinonediimine and Hdab as a bidentate monoamide. The crystal structures of these complexes are discussed in this account. (author)

  5. Neutral currents

    International Nuclear Information System (INIS)

    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

  6. Approach to synthesis and structure of chiral multi-functionalized organophosphorus derivatives

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The diastereomerically pure organophosphorus derivatives containing multiple chiral centers 5 and 5( were obtained, respectively, in 62%-84% yields with ≥98% de (diastereomeric excess) via asymmetric reaction of the chiron, 3-bromo-2(5H)-furanone 4 with racemic diethyl (-hydroxyl- substituted-phosphonates 3+ 3( and further through the separation of the diastereomeric mixture by chromatography. The structures of the chiral organophosphorus derivatives were identified on the basis of their elementary and spectroscopic data, such as IR, 1H NMR,13C NMR, MS and X-ray crystallography. In this report, the synthetic methods ofthe active organophosphorus substrates, the structure characterization and resolution, the optical purity and the stereochemistry of the chiral products were discussed. These results provide a new idea and a good method for synthesizing some natural organophosphorus compounds and approaching their biological activities, also a facile route to the application of organophosphorus substrates.

  7. Synthesis, spectroscopic characterisation, DNA cleavage, superoxidase dismutase activity and antibacterial properties of some transition metal complexes of a novel bidentate Schiff base derived from isatin and 2-aminopyrimidine

    Science.gov (United States)

    Nitha, L. P.; Aswathy, R.; Mathews, Niecy Elsa; Sindhu kumari, B.; Mohanan, K.

    2014-01-01

    Complexes of manganese(II), cobalt(II), nickel(II), copper(II) and zinc(II) with a Schiff base, formed by the condensation of isatin with 2-aminopyrimidine have been synthesised and characterised through elemental analysis, molar conductance measurements, magnetic susceptibility, IR, UV-Vis, 1HNMR, FAB mass and EPR spectral studies. The spectral data revealed that the ligand acts as neutral bidentate, coordinating to the metal ion through the carbonyl oxygen and azomethine nitrogen. Molar conductance values adequately support the electrolytic nature of the complexes. On the basis of the above observations the complexes have been formulated as [M(ISAP)2]X2, where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II); X = Cl, OAc; ISAP = 2-[N-indole-2-one]aminopyrimidine. The ligand and copper(II) complex were subjected to X-ray diffraction studies. The DNA cleavage study was monitored by gel electrophoresis method. The superoxide dismutase (SOD) mimetic activities of the ligand and the metal complexes were checked using NBT assay. The in vitro antibacterial activity of the synthesized compounds has been tested against gram negative and gram positive bacteria.

  8. In vitro and in vivo evaluation of bidentate, water-soluble phosphine ligands as anchor groups for the organometallic fac-[99mTc(CO)3]+-core

    International Nuclear Information System (INIS)

    The organometallic precursor fac-[99mTc(OH2)3(CO)3]+, 1a, was reacted with the bidentate, water-soluble phosphine ligands bis(bis(hydroxymethyl)phosphino)ethane (HMPE) and bis(bis(hydroxymethyl)phosphino)benzene (HMPB) in 0.9% saline to produce complexes in >95% yields. High performance liquid chromatography analyses indicate the initial formation of the complexes fac-[99mTcCl(CO)3L] (L=HMPE 2a,HMPB 3a). The neutral complexes ultimately lose the coordinated chloride to produce the cationic species fac-[99mTc(OH2)(CO)3L]+ 2b/3b. In vitro studies showed a high stability of 2b/3b over a wide pH range for >24 h. No decomposition or alteration of the complexes was observed even in the presence of excess histidine, cysteine, or human serum albumin. Experiments performed in normal mice demonstrated a fast clearance of the cationic compounds 2b/3b from the blood pool and clearance through the hepatobiliary and the urinary pathways

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

    Science.gov (United States)

    Blasius, Clemens K; Intorp, Sebastian N; Wadepohl, Hubert

    2016-01-01

    Summary 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. PMID:27340475

  10. Neutral Current $\

    CERN Document Server

    Chauhan, S; Singh, S K

    2011-01-01

    We calculate cross sections for the neutral current induced neutrino/antineutrino reaction from $^{208}Pb$ target and applied it to study Supernova neutrino event rates. The calculations are done in local density approximation taking into account Pauli blocking, Fermi motion effects and renormalization of weak transition strengths in the nuclear medium. The numerical results for the neutrino nucleus total cross sections have been averaged over the various Supernova neutrino/antineutrino fluxes available in literature.

  11. Monetary Neutrality

    OpenAIRE

    Apostolos Serletis; Zisimos Koustas

    2015-01-01

    We test the long-run neutrality of money proposition for the United States using the King and Watson (1997) methodology paying attention to the integration and cointegration properties of the variables. We use quarterly data (over the period from 1967:1 to 2014:1) and the new Center for Financial Stability Divisia monetary aggregates, documented in detail in Barnett et al. (2013). We make a comparison among the narrower monetary aggregates, M1 M2M, M2M, M2, and ALL, and the broad monetary agg...

  12. Synthesis, spectral and catalytic dehydrogenation studies of ruthenium complexes containing NO bidentate ligands

    Science.gov (United States)

    Shoair, A. F.; El-Bindary, A. A.

    2014-10-01

    The synthesis and characterization of ruthenium mononuclear complexes containing NO bidentate ligands are reported. The complexes cis-[RuII(bpy)2L](PF6)n (1a-c), [RuIIICl(L)2(H2O)] (2a-b) and [RuIIICl2(L)2]Cl (2c) were prepared by the reaction of cis-[RuIICl2(bpy)2]·2H2O (bpy = 2,2";-bipyridine) and/or RuCl3·nH2O with the Ligands: 2-aminophenol (2-aph), 8-hydroxyquinoline (8-hq) and 4-aminoantipyrine (4-apy). These complexes were characterized by elemental analysis, spectroscopic (IR, UV-Vis, 1H NMR, ESR) and magnetic susceptibility measurements. The ligand field parameters, Δo (splitting parameter), B (Racah parameter of interelectronic repulsion), and β (nephelauxetic ratio) were calculated. The redox properties were also investigated electrochemically by cyclic voltammetry. The complexes cis-[RuII(bpy)2(8-hq)](PF6)2 (1b) and [RuIIICl(8-hq)2(H2O)] (2b) have been investigated in conjunction with N-methylmorpholine-N-oxide (NMO) as co-oxidant for the catalytic dehydrogenation of benzyl amine, p-methyl benzylamine and p-nitrobenzylamine to their respective nitriles.

  13. Mesogenic copper(II) complexes with [1,2,3]-triazole-based bidentate Schiff bases

    Indian Academy of Sciences (India)

    Guan-Yeow Yeap; Boon-Teck Heng

    2014-01-01

    The first mesogenic Cu(II) complex with [1,2,3]-triazole-based bidentate Schiff bases with flexible terminal alkyl chain, CnH2n+1 (even parity of n = 10-18) has been successfully synthesized. The heterocyclic triazole core was introduced into the target compound through the click reaction between azidoalkane and propargyl aldehyde. All the uncoordinated ligands and target complexes were characterized by elemental analysis, FT-IR, 1H-NMR and UV-visible spectroscopic techniques. The observation under the polarized light and differential scanning calometry (DSC) shows that the triazole-based ligands exhibit unstable SmA phase which are not reproducible upon subsequent heating and cooling. Interestingly, the whole homologues of Cu(II) complexes show exclusively stable focal conic fan-shaped texture characteristic of SmA phase. This can be ascribed to the presence of Cu-N and Cu-O coordination modes which enhance the collinearity and molecular anisotropy. On the other hand, the Cu(II) complexes are thermally more stable as compared to their corresponding ligands.

  14. Bidentate RNA–magnesium clamps: On the origin of the special role of magnesium in RNA folding

    OpenAIRE

    Petrov, Anton S.; Bowman, Jessica C.; Harvey, Stephen C.; Williams, Loren Dean

    2011-01-01

    Magnesium plays a special role in RNA function and folding. Although water is magnesium's most common first-shell ligand, the oxyanions of RNA have significant affinity for magnesium. Here we provide a quantum mechanical description of first-shell RNA–magnesium and DNA–magnesium interactions, demonstrating the unique features that characterize the energetics and geometry of magnesium complexes within large folded RNAs. Our work focuses on bidentate chelation of magnesium by RNA or DNA, where ...

  15. RELATIONSHIP OF NEUROPATHY TARGET ESTERASE INHIBITION TO NEUROPATHOLOGY AND ATAXIA IN HENS GIVEN ORGANOPHOSPHORUS ESTERS

    Science.gov (United States)

    Adult WhiteLeghorn hens were acutely exposed to 3 dosages of the following organophosphorus esters: mipafox, tri-ortho-tolyl phosphate (TOTP), penyl saligenin phosphate, diisppropylophosphoro-fluoridate (DFP), malathion and dichlorvos. europathy target esterase (NTE) activity was...

  16. Levels of Organophosphorus Pesticides in Medicinal Plants Commonly Consumed in Iran

    Directory of Open Access Journals (Sweden)

    Parisa Sarkhail

    2012-08-01

    Full Text Available 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.

  17. Organophosphorus Compound DEPBT as a Coupling Reagent for Oligopeptides and Peptoids Synthesis: Studies on Its Mechanism

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Some oligopeptidcs and peptoids were synthesized by applying the organophosphorus compound DEPBT as a coupling rcagent. D-Biotin-OOBt was obtained unexpcctcdly. A proposed reaction mechanism for DEPBT-mediated coupling was proved.

  18. 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.

  19. Characterization of organophosphorus flame retardants' sorption on building materials and consumer products

    Science.gov (United States)

    Better understanding the transport mechanisms of organophosphorus flame-retardants (OPFRs) in the residential environment is important to more accurately estimate their indoor exposure and develop risk management strategies that protect human health. This study describes an impro...

  20. HIGH PERFORMANCE LIQUID CHROMATOGRAPHIC SEPARATION OF THE ENANTIOMERS OF ORGANOPHOSPHORUS PESTICIDES ON POLYSACCHARIDE CHIRAL STATIONARY PHASES

    Science.gov (United States)

    High-performance liquid chromatographic separation of the individual enantiomers of 12 organophosphorus pesticides (OPs) was obtained on polysaccharide enantioselective HPLC columns using alkane-alcohol mobile phase. The OP pesticides were crotoxyphos, dialifor, fonofos, fenamiph...

  1. HPLC SEPARATION OF CHIRAL ORGANOPHOSPHORUS PESTICIDES ON POLYSACCHARIDE CHIRAL STATIONARY PHASES

    Science.gov (United States)

    High-performance liquid chromatographic separation of the individual enantiomers of 12 organophosphorus pesticides (OPs) were obtained on polysaccharide chiral HPLC columns using an alkane-alcohol mobile phase. The OP pesticides were crotoxyphos, dialifor, dyfonate, fenamiphos, ...

  2. Cumulative risk assessment of the intake of organophosphorus and carbamate pesticides in the Danish diet

    DEFF Research Database (Denmark)

    Jensen, A. F.; Petersen, Annette; Granby, Kit

    2003-01-01

    in the Danish nation-wide food consumption survey in 1995. The pesticide data are based on the Danish pesticide residue-monitoring programme from 1996-2001. The amount of 35 organophosphorus pesticides and carbamates were included in the cumulative risk assessment. Processing factors, such as reduction......The aim of the study is to evaluate the potential cumulative effects of organophosphorus and carbamate pesticides that act through a common mechanism of toxicity, and to assess the long- and short-term risks for the Danish population. The intake estimates are based on dietary intake data collected...... of pesticide levels by rinsing and peeling, were applied in the exposure assessment. The "Toxicity Equivalence Factor" (TEF) approach was used to normalise the toxicity of the different organophosphorus and carbamate pesticides. Cumulative chronic exposure of organophosphorus and carbamates pesticides via...

  3. Comparative Toxicological Study between Exposed and Non-Exposed Farmers to Organophosphorus Pesticides

    OpenAIRE

    Fariba Taghavian; Gholamhassan Vaezi; Mohammad Abdollahi; Ali Akbar Malekirad

    2016-01-01

    Objective: The purpose of this work was to compare DNA damage, acetylcholinesterase (AChE) activity, inflammatory markers and clinical symptoms in farmers exposed to organophosphorus pesticides to individuals that had no pesticide exposure. Materials and Methods: We conducted a cross-sectional survey with a total of 134 people. The subject group consisted of 67 farmers who were exposed to organophosphorus pesticides. The control group consisted of 67 people without any contact ...

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

    OpenAIRE

    Joshi, P.; P Manoria; Joseph, D., T.; Z Gandhi

    2013-01-01

    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 report...

  5. A nano-silver enzyme electrode for organophosphorus pesticide detection.

    Science.gov (United States)

    Zheng, Qiqi; Yu, Yonghua; Fan, Kai; Ji, Feng; Wu, Jian; Ying, Yibin

    2016-08-01

    A nano-silver electrode immobilizing acetylcholinesterase (AChE) for the detection of organophosphorus (OPPs) pesticides is reported. Scanning electron microscopy (SEM) was used to characterize the surface structure of two kinds of electrodes fabricated with different sizes of silver powders and the interface between chitosan layer and nano-silver powder layer. Cyclic voltammetry was carried out to characterize the response of silver/chitosan electrode in the absence and in the presence of thiocholine (TCh). It was also used to evaluate the insulativity of the chitosan layer. An amperometric method was performed to measure the response of the electrode to TCh, which is the product of the enzymatic reaction for detecting organophosphorus pesticides indirectly. Although there are many kinds of nanoparticles, silver was chosen for its internal advantage in detecting TCh at low potential without further modification. The result shows nano-silver powder has better performance than usual silver powder, and the limit of detection of paraoxon is 4 ppb under optimized conditions. One percent (w/v) chitosan solution was used as binder for the immobilization of nano-silver powder and AChE, which made it possible for independent electrode fabrication at room temperature, whereas 3% (w/v) chitosan solution was used as insulating compound for controlling the electrode area. Unlike traditional organic insulating ink, chitosan is safe and environmentally friendly, and it is used as insulating material for the first time. The flexible nano-silver/AChE/chitosan electrode was evaluated in Chinese chives and cabbage, and the recoveries of standard addition were 105.11 and 96.41%, respectively. Owing to the antibacterial property of nano-silver and the biocompatibility, safety, and biodegradability of chitosan, the proposed method is safe, facile, environmentally friendly, and has great potential in organophosphorus pesticide detection for food safety. Graphical Abstract Current

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

    Energy Technology Data Exchange (ETDEWEB)

    Moeller, Axel, E-mail: axel.moeller@hzg.de [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of Coastal Research, Department for Environmental Chemistry, Max-Planck-Strasse 1, 21502 Geesthacht (Germany); Xie Zhiyong; Caba, Armando; Sturm, Renate; Ebinghaus, Ralf [Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, Institute of Coastal Research, Department for Environmental Chemistry, Max-Planck-Strasse 1, 21502 Geesthacht (Germany)

    2011-12-15

    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 {Sigma}{sub 8}OPs concentration ranged from 110 to 1400 pg m{sup -3} while tris(2-chloroisopropyl) phosphate (TCPP) dominated all samples with individual concentrations up to 1200 pg m{sup -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{sup -2} d{sup -1} for {Sigma}{sub 8}OPs were estimated leading to a minimum annual flux of 710 {+-} 580 kg y{sup -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{sup 3}. - Organophosphorus flame retardants, in particular tris(2-chloroisopropyl) phosphate, are emitted into the North Sea atmosphere by Western European countries.

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

    International Nuclear Information System (INIS)

    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 Σ8OPs 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 Σ8OPs 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/m3. - Organophosphorus flame retardants, in particular tris(2-chloroisopropyl) phosphate, are emitted into the North Sea atmosphere by Western European countries.

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

    International Nuclear Information System (INIS)

    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.

  9. Environmental Fate of Organophosphorus Compounds Related to Chemical Weapons

    Energy Technology Data Exchange (ETDEWEB)

    Davisson, M L; Love, A H; Vance, A; Reynolds, J G

    2005-02-08

    Man-made organophosphorus compounds have been widely distributed throughout our environment as pesticides since their development during and after WWII. Many important studies have documented their relative persistence and toxicity. Development and use of some organophosphorus compounds as nerve agents gave rise to a separate but parallel effort to understand environmental persistence. In this latter case, the experiments have focused mainly on evaporation rates and first-order reaction kinetics. However, because organophosphorus compounds are easily polarized, the ionic content of a surrounding media directly factors into these reaction rates, but limited work in this regard has been done under environmentally relevant conditions. Furthermore, limited experiments investigating persistence of these agents on soil has resulted in widely varying degradation rates. Not surprisingly, no studies have investigated affinities of organophosphorus nerve agents to mineral or organic matter typically found in soil. As a result, we initiated laboratory experiments on dilute concentrations of nerve agent O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothiolate (VX) to quantify persistence in simulated environmental aqueous conditions. A quantitative analytical method was developed for VX and its degradation products using High Performance Liquid Chromatography-Electrospray Ionization-Mass Spectrometry (HPLC-ESI-MS). VX hydrolysis rate is known to have a pH-dependency, however, the type of buffer and the relative proportion of different nucleophiles in solution significantly affect the overall rate and mechanism of degradation. For example, dissolved carbonate, a weak nucleophile dominating natural water, yielded pseudo-first order rate constants of {approx} 8 x 10{sup -3}/hr at pH 5 and 2 x 10{sup -2}/hr at pH 11. This small pH-dependent variation departs significantly from widely accepted rates at this pH range (4 x 10{sup -4}/hr to 8 x 10{sup -2}/hr) that were based on

  10. Development of the Artificial Antigens for the Organophosphorus Insecticide chlorpyrifos

    Institute of Scientific and Technical Information of China (English)

    ZHU Guo-nian; WU Gang; WU Hui-ming

    2004-01-01

    This study reported that the hapten of the organophosphorus insecticide chlorpyrifos,O,Odiethyl-O-[3,5-dichloro-6-(2-carboxyethyl)thio-2-pyridyl]phosphorothioate(named AR) was synthesized by using technical grade chlorpyrifos reacted with 3-marcapropanoic acid in hot alkaline solution.The hapten was conjugated to bovine serum albumin (BSA) with the modified active ester method to form artificial immune antigen.The ratio of AR:BSA was 39:1.The artificial coating antigen for chlorpyrifos was synthesized by conjugating AR to ovalbumin (OVA) with the mixed-anhydride method,and the ratio was 13:1.The anti-chlorpyrifos polyclonal antibodies were obtained by using the artificial immune antigen (AR-BSA) to immune in the rabbits.

  11. Fluorescent chemosensors for toxic organophosphorus pesticides: a review.

    Science.gov (United States)

    Obare, Sherine O; De, Chandrima; Guo, Wen; Haywood, Tajay L; Samuels, Tova A; Adams, Clara P; Masika, Noah O; Murray, Desmond H; Anderson, Ginger A; Campbell, Keith; Fletcher, Kenneth

    2010-01-01

    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. PMID:22163587

  12. 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.

  13. Organophosphorus agent induced delayed neuropathy: a case report

    Directory of Open Access Journals (Sweden)

    Harshit Acharya

    2016-02-01

    Full Text Available A 40-year old male, was presented with complaint of difficulty in walking with inability to flex foot and toes in bilateral feet ( and ldquo;foot drop and rdquo;, which was acute at the onset and gradually progressive since the past 7 days. The patient's wife and their 2 children had similar complaint with the same period of onset. At home, his family used cottonseed oil as cooking oil with wheat grain mixed with castor oil. On neurological examination, he was found to have lower motor neuron weakness with spasticity. After ruling out other common causes of polyneuropathy and lower motor weakness; due to high suspicion of poisoning by food adulterant, RBC acetyl cholinesterase (AChE and plasma cholinesterase (BuChE were tested at National Institute of Occupational Health (NIOH, which came low and confirmed diagnosis of Organophosphorus (OP poisoning. Nerve conduction study was done; which showed decreased amplitude of conduction in bilateral peroneal and right tibial nerve along with decreased mean nerve conduction velocity of bilateral median nerve. Thus patient was diagnosed with organophosphorus agent induced delayed axonal type of polyneuropathy and physiotherapy was started as treatment. OP compounds are a diverse group of chemicals which are principally used as insecticides in agriculture. Following organophosphate poisoning (OPP, 3 well-defined neurological syndromes are recognised: cholinergic crisis, intermediate syndrome and delayed polyneuropathy. Some organophosphates, particularly triorthocresyl phosphate (TOCP and tricresyl phosphate (TCP, produce delayed neuropathy. On ingestion, they do not produce significant cholinergic crisis, but 7 to 20 days later it leads to a pure motor axonal neuropathy with wrist and foot drop. The mechanism may involve inhibition of neuropathy target esterase (NTE, which is found in the brain, peripheral nerves, and lymphocytes. This form of toxicity has been seen occasionally in small epidemics in

  14. Neutral currents

    International Nuclear Information System (INIS)

    A short survey of the new experimental data on weak neutral currents is given, followed by a comparison with modern theoretical models. Cross sections of the anti νsub(e)e → anti νsub(e)e, anti νsub(μ)e→ νsub(μ)e, νp → νp and anti νp → anti νp elastic scattering as well as inclusive cross sections of the ν+N → ν+X and anti ν+N → anti ν+X deep inelastic scattering are presented. On the basis of the comparison the Weinberg-Salam model is concluded to be in a good agreement with the shape of the cross sections. Six-quark vector models appear to be ruled out. The five-quark model due to Achiman, Koller and Walsh and two versions of the Gursey-Sikivie model satisfactorily account for the observed data in shape and in magnitude

  15. Reactivity of pentacoordinate ferrous porphyrins with exo-bidentate nitrogenous bases. Mononuclear and binuclear complexes in dynamic equilibrium

    International Nuclear Information System (INIS)

    The reaction of several exo-bidentate nitrogenous bases with thiocarbonyl(5,10,15,20-tetraphenylporphinato)iron(II) afforded six-coordinate mononuclear and binuclear porphyrin complexes in dynamic equilibrium. This reaction was carried out in halocarbon solvents and monitored both spectrally and electrochemically. Within the potential limits of the solvent/supporting electrolyte system, each complex underwent at least four separate electron-transfer reactions with retention of the thiocarbonyl ligand. An electron-transfer pathway is presented and supported by the combined results of infrared and electronic absorption spectra, variable-temperature proton NMR, variable-temperature electrochemical, and spectroelectrochemical experiments. 46 references, 5 figures, 2 tables

  16. Bidentate Lewis Acid Catalyzed Domino Diels-Alder Reaction of Phthalazine for the Synthesis of Bridged Oligocyclic Tetrahydronaphthalenes.

    Science.gov (United States)

    Schweighauser, Luca; Bodoky, Ina; Kessler, Simon N; Häussinger, Daniel; Donsbach, Carsten; Wegner, Hermann A

    2016-03-18

    A domino process consisting of an inverse and a normal electron-demand Diels-Alder reaction is presented for the formation of bridged tri- and tetracyclic 1,2,3,4-tetrahydronaphthalenes catalyzed by a bidentate Lewis acid. The products were synthesized in a one-pot reaction from commercially available starting materials and contain up to six stereogenic centers. The tetrahydronaphthalenes were isolated as single diastereomers and are derivatives of phenylethylamine, which is well-known as a scaffold of amphetamine or dopamine. PMID:26943286

  17. The Synthesis of Iron Sulphide Nanocrystals from Iron(II) Complexes with O-alkylxanthates and Bidentate Nitrogen Donor Ligands

    OpenAIRE

    Fei, Zhengkai

    2013-01-01

    A series of iron(II) complexes with O-alkylxanthates and bidentate nitrogen donor ligands, Fe(S2COR)2·L (where R = Et, L = TMEDA (1); R = nPr, L = TMEDA (2); R = Et, L = bipy (3); R = nPr, L = bipy (4); R = iPr, L = bipy (5); R = Et, L = phen (6); R = nPr, L = phen (7); R= iPr, L = phen (8)), were synthesized as single source precursors for nanocrystals. Among them, (2) and (6) have been crystallized and their structures were determined by single-crystal X-ray crystallography.The precursors f...

  18. POLYKETONE FROM ETHYLENE WITH CARBON MONOXIDE CATALYZED BY NOVEL CATALYST SYSTEMS BASED ON COPPER WITH BIDENTATE PHOSPHORUS CHELATING LIGANDS

    Institute of Scientific and Technical Information of China (English)

    Jun Huang; Feng-bo Li; Jin Zou; Guo-qing Yuan; Xiu-li Shi; Ding-sheng Yu

    2003-01-01

    Copolymerization of ethylene with carbon monoxide was performed with Cu catalyst systems. Novel catalyst systems based on Cu (Cu(CH3COO)2/ligand/acid) were firstly reported for the copolymerization of ethylene with carbon monoxide, in which the ligand was a bidentate phosphorus chelating ligand. The experimental results showed that this kind of Cu catalyst system exhibited high activity. When DPPP (1,3-bis(diphenylphosphine)propane) and CH3COOH were used catalyst system had the advantages of high stability and low cost.

  19. Multiresidue determination of organophosphorus pesticides in solid waste environmental samples by gas chromatography.

    Science.gov (United States)

    Wu, Shijian; Zhang, Huanyan; Chen, Beibei; Liu, Ming; Shen, Yanjun; Sha, Qichao; Zhi, Yuee; Zhou, Pei

    2014-01-01

    The method for the determination of 12 organophosphorus pesticides in solid waste was established. The organophosphorus pesticides were analyzed by Soxhlet extraction or accelerated solvent extraction (ASE)-SPE cartridge-flame photometric detector (FPD), and leaching solution by rotary oscillation-positive pressure filtration-liquid-liquid extraction-SPE cartridge-FPD. The differences of extraction efficiencies between Soxhlet and ASE were compared. Solvent of Soxhlet extraction, purification and recovery of organophosphorus pesticides in leaching conditions were also studied. The recoveries were 54.2-119.8%, and the average recovery was 87.7%. The RSD was 1.89-9.10% (n = 6), the average RSD was 6.88%, and the detection limit was 0.27-0.69 μg/kg. PMID:25903001

  20. Transient expression of organophosphorus hydrolase to enhance the degrading activity of tomato fruit on coumaphos

    Institute of Scientific and Technical Information of China (English)

    Jie-hong ZHAO; De-gang ZHAO

    2009-01-01

    We constructed an expression cassette of the organophosphorus pesticide degrading (opd)gene under the control of the E8 promoter.Then opd was transformed into tomato fruit using an agroinfiltration transient expression system.β-Glueuronidase (GUS) staining,reverse transcription-polymerase chain reaction (RT-PCR),wavelength scanning,and fluorescent reaction were performed to examine the expression of the opd gene and the hydrolysis activity on eoumaphos of organophosphorus hydrolase (OPH) in tomato fruit.The results show that the agroinfiltrated tomato fruit-expressed OPH had the maximum hydrolysis activity of about 11.59 U/mg total soluble protein.These results will allow us to focus on breeding transgenie plants that could not only enhance the degrading capability of fruit and but also hold no negative effects on pest control when spraying organophosphorus pesticides onto the seedlings in fields.

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

    International Nuclear Information System (INIS)

    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

  2. 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.

  3. Clinico-epidemiological characteristics of patients presenting with organophosphorus poisoning

    Directory of Open Access Journals (Sweden)

    Indranil Banerjee

    2012-01-01

    Full Text Available Background: Organophosphorus (OP poisoning is a major health problem all over the world, particularly in the developing countries. Aim: The present study aims to explore the clinical and epidemiological features found in patients presenting with OP poisoning. Materials and Methods: A 1-year cross-sectional study was conducted on patients presenting with clinical features of OP poisoning in a tertiary care medical college. Results: A total of 968 patients presented during the study period. Poisoning with suicidal intent (82.02% was more common than the accidental one (17.98%. Majority of the patients were housewives (42% followed by farmers, shopkeepers, laborers, students. Methyl parathion was the most common poison consumed by the patients (35.74% followed by diazinon, chlorpyriphos, dimicron. Nausea and vomiting (85.02% was the most common symptom while miosis was the most common sign observed in 91.94% patients. A total of 56 patients of OP poisoning died (5.78% with respiratory failure being the primary cause of death followed by CNS depression, cardiac arrest, and septicaemia. Conclusion: The present study showed that majority of the patients were of young age with females outnumbering males. Poisoning with suicidal intent was more common than accidental. Nausea and vomiting was the most common symptom reported by the patients while miosis was the most common sign observed by the treating physicians of the research team.

  4. 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. PMID:27396650

  5. Subchronic organophosphorus ester-induced delayed neurotoxicity in mallards

    Science.gov (United States)

    Hoffman, D.J.; Sileo, L.; Murray, H.C.

    1984-01-01

    Eighteen-week-old mallard hens received 0, 10, 30, 90, or 270 ppm technical grade EPN (phenylphosphonothioic acid O-ethyl-O-4-nitrophenyl ester) in the diet for 90 days. Ataxia was first observed in the 270-ppm group after 16 days, in the 90-ppm group after 20 days, in the 30-ppm group after 38 days; 10 ppm failed to produce ataxia. By the end of 90 days all 6 birds in the 270-ppm group exhibited ataxia or paralysis whereas 5 of 6 birds in the 90-ppm group and 2 of 6 birds in the 30-ppm group were visibly affected. Treatment with 30 ppm or more resulted in a significant reduction in body weight. Brain neurotoxic esterase activity was inhibited by averages of 16, 69, 73, and 74% in the 10-, 30-, 90-, and 270-ppm groups, respectively. Brain acetylcholinesterase, plasma cholinesterase, and plasma alkaline phosphatase were significantly inhibited as well. Distinct histopathological effects were seen in the 30-, 90-, and 270-ppm groups which included demyelination and degeneration of axons of the spinal cord. Additional ducks were exposed in a similar manner to 60-, 270-, or 540-ppm leptophos (phosphonothioic acid O-4-bromo-2,5-dichlorophenyl-O-methylphenyl ester) which resulted in similar behavioral, biochemical, and histopathological alterations. These findings indicate that adult mallards are probably somewhat less sensitive than chickens to subchronic dietary exposure to organophosphorus insecticides that induce delayed neurotoxicity.

  6. Recovery of cholinesterase activity in mallard ducklings administered organophosphorus pesticides

    Science.gov (United States)

    Fleming, W.J.; Bradbury, S.P.

    1981-01-01

    Oral doses of the organophosphorus pesticides acephate, dicrotophos, fensulfothion, fonofos, malathion, and parathion were administered to mallard ducklings (Anas platyrhynchos), and brain and plasma cholinesterase (ChE) activities were determined for up to 77 d after dosing. In vivo recovery of brain ChE activity to within 2 standard deviations of the mean activity of undosed birds occurred within 8 d, after being depressed an average of 25-58% at 24 h after dosing. In vivo recovery of plasma ChE appeared as fast as or faster than that of brain, but the pattern of recovery was more erratic and therefore statistical comparison with brain ChE recovery was not attempted. In vitro tests indicated that the potential for dephosphorylation to contribute to in vivo recovery of inhibited brain ChE differed among chemical treatments. Some ducklings died as a result of organophosphate dosing. In an experiment in which ducklings within each treatment group received the same dose (mg/kg), the brain ChE activity in birds that died was less than that in birds that survived. Brain ChE activities in ducklings that died were significantly different among pesticide treatments: fensulfothion > parathion> acephate > malathion (p < 0.05).

  7. 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

  8. Effect of organophosphorus insecticides on phosphorylation of the M2 muscarinic acetylcholine receptor

    Institute of Scientific and Technical Information of China (English)

    Shuyin Li; Liming Zou; Carry Pope

    2008-01-01

    BACKGROUND: Organophosphorus insecticides may promote the accumulation of acetylcholine at synapses and the neuromuscular junction by inhibiting acetylcholinesterase activity to cause disturbance of neural signal conduction and induce a toxic reaction. Organophosphorus insecticides may act on M2 muscarinic acetylcholine receptors, whose combination with G proteins is regulated by phosphorylation of G protein-coupled receptor kinase 2.OBJECTIVE: To investigate the effects of organophosphorus insecticides on the phosphorylation of G protein-coupled receptor kinase 2-mediated M2 muscarinic acetylcholine receptors and to reveal other possible actions of organophosphorus insecticides.DESIGN, TIME AND SETTING: An observational study, which was performed in the Central Laboratory of Shenyang Medical College, and Department of Physiological Sciences, College of Veterinary Medicine, Oklahoma State University from June 2002 to December 2004.METHODS: The M2 muscarinic acetylcholine receptor was extracted and purified from pig brain using affinity chromatography. Subsequently, the purified M2 muscarinic acetylcholine receptor, G protein-coupled receptor kinase 2, and [OP32] ATP were incubated with different concentrations of paraoxon and chlorpyrifos oxon together. The mixture then underwent polyacrylamide gel electrophoresis, and the gel film was dried and radioactively autographed to detect phosphorylation of the M2 muscarinic acetylcholine receptor. Finally, the radio-labeled phosphorylated M2 receptor protein band was excised for counting with an isotope liquid scintillation counter.MAIN OUTCOME MEASURES: Effects of chlorpyrifos oxon, paraoxon, chlorpyrifos, and parathion in different concentrations on the phosphorylation of the M2 muscarinic acetylcholine receptor; effects of chlorpyrifos oxon on the phosphorylation of the adrenergic receptor.CONCLUSION: Different kinds of organophosphorus insecticides have different effects on the phosphorylation of the G protein

  9. A field evaluation of frogs as a potential source of secondary organophosphorus insecticide poisoning

    Science.gov (United States)

    Powell, G.V.N.; DeWeese, L.R.; Lamont, T.G.

    1982-01-01

    Because amphibians are relatively resistant to organophosphorus insecticides and can bioaccumulate residues to high levels, they may be a source of secondary poisoning for vertebrates that feed on them. This hypothesis was tested by determining residues in breeding upland chorus frogs Pseudacris triseriata, that were collected from ponds treated with the organophosphorus insecticide fenthion. Frogs were collected up to 3-days posttreatment in four areas that were treated with fenthion formulated in either diesel oil or water. No residues of fenthion were detected above the 0.01 ppm level of analytical sensitivity. These results indicate that the frogs were not a likely source of secondary poisoning for predatory vertebrates.

  10. Synthesis of bidentate o-carborane-containing phosphine and arsine ligands and preparation of their complexes with chromium-, molybdenum-, tungsten-, iron- and nickel carbonyls

    International Nuclear Information System (INIS)

    A number of bidentate o-carborane phosphine and arsine ligands have been synthesized and their chelate complexes with carbonyls of chromium, molybdenum, tungsten, iron and nickel are obtained. 1-mercapto-2-dimethylarsnomethyl-o-carborane and 1-mercapto-2-diethylaminomethyl-o-carborane with molybdenum and tungsten carbonyls provide substitution products of only one CO group. 1-diphenylphosphino-2-diphenylphosphinomethyl-o-carborane and 1,2-bis(diphenylphosphinomethyl)-o-carborane form complexes with NiCl2. Simplicity of complex formation of bidentate carborane ligands with group 6 metal carbonyls increases in the series Cr(CO)6 6 6

  11. QSAR for cholinesterase inhibition by organophosphorus esters and CNDO/2 calculations for organophosphorus ester hydrolysis. [quantitative structure-activity relationship, complete neglect of differential overlap

    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 cationic groups on the inhibitor, but not with steric substituent constants. CNDO/2 calculations were performed on a separate set of organophosphorus esters, RR-primeP(O)X, where R and R-prime 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 hydrolysis rate constant.

  12. [ORGANOPHOSPHORUS FLAME RETARDANTS - TOXICITY AND INFLUENCE ON HUMAN HEALTH].

    Science.gov (United States)

    Bruchajzer, Elżbieta; Frydrych, Barbara; Szymańska, Jadwiga Anna

    2015-01-01

    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-ethylhexyl)phosphate (TEHP), tris(2-butoxyethyl)phosphate (TBEP), triphenyl phosphate (TPP), tris(2-chloroethyl)phosphate (TCEP), tetrakis(hydroxymethyl)-phosphonium chloride (THPC), tributyl phosphate (TBP), tricresyl phosphate (TCP), tris(2-chloroisopropyl)phosphate (TCPP), tris(1,3-dichloroisopropyl)phosphate (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. PMID:26294315

  13. 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

  14. Complexation Studies of Bidentate Heterocyclic N-Donor Ligands with Nd(III) and Am(III)

    Energy Technology Data Exchange (ETDEWEB)

    Ogden, Mark; Hoch, Courtney L.; Sinkov, Sergey I.; Meier, Patrick; Lumetta, Gregg J.; Nash, Kenneth L.

    2011-11-28

    A new bidentate nitrogen donor complexing agent that combines pyridine and triazole functional groups, 2-((4-phenyl-1H-1,2,3-triazol-1-yl)methyl)pyridine (PTMP), has been synthesized. The strength of its complexes with trivalent americium (Am3+) and neodymium (Nd3+) in anhydrous methanol has been evaluated using spectrophotometric techniques. The purpose of this investigation is to assess this ligand (as representative of a class of similarly structured species) as a possible model compound for the challenging separation of trivalent actinides from lanthanides. This separation, important in the development of advanced nuclear fuel cycles, is best achieved through the agency of multidentate chelating agents containing some number of nitrogen or sulfur donor groups. To evaluate the relative strength of the bidentate complexes, the derived constants are compared to those of the same metal ions with 2,2*-bipyridyl (bipy), 1,10-phenanthroline (phen), and 2-pyridin-2-yl-1H-benzimidazole (PBIm). At issue is the relative affinity of the triazole moiety for trivalent f element ions. For all ligands, the derived stability constants are higher for Am3+ than Nd3+. In the case of Am3+ complexes with phen and PBIm, the presence of 1:2 (AmL2) species is indicated. Possible separations are suggested based on the relative stability and stoichiometry of the Am3+ and Nd3+ complexes. It can be noted that the 1,2,3-triazolyl group imparts a potentially useful selectivity for trivalent actinides (An(III)) over trivalent lanthanides (Ln(III)), though the attainment of higher complex stoichiometries in actinide compared with lanthanide complexes may be an important driver for developing successful separations.

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

    OpenAIRE

    M.C. Abete; G. Puzone; Fornasero, S; R Tarasco; B. Vivaldi; C. Biglia; S. Chiarelli; G. Amisano

    2009-01-01

    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.

  16. Occurrence and risk assessment of organophosphorus and brominated flame retardants in the River Aire (UK)

    International Nuclear Information System (INIS)

    This study presents the occurrence and risk of PBDEs, new brominated and organophosphorus flame retardants along a river affected by urban and industrial pressures (River Aire, UK). Tris(2-choroethyl) phosphate (TCEP), tris(2-chloro-1-methylethyl) phosphate (TCPP), tris[2-chloro-1-(chloromethyl)ethyl] phosphate (TDCP) and triphenyl phosphate (TPhP) were detected in all samples, with TCPP present at the highest concentrations, ranging from 113 to 26 050 ng L-1. BDE-209 was detected in most of the sampled sites, ranging from 17 to 295 ng L−1, while hexabromobenzene (HBB) and pentabromoethyl benzene (PBEB) were seldom detected. A risk quotients based on predicted no effect concentrations (PNEC) and flame retardants water concentration proved significant risk for adverse effects for algae, Daphnia and fish in sites close to industrial and urban sewage discharges. This study provides a protocol for the risk estimation of priority and new generation flame retardants based on river concentrations and toxicological values. -- Highlights: •Brominated and organophosphorus flame retardants were monitored in River Aire (UK). •BDE-209 and organophosphorus flame retardants were detected at high concentrations. •A risk assessment was performed based on water concentration and acute toxicity data. •Low to significant risk for adverse effects was observed for algae, fish and Daphnia. -- Organophosphorus flame retardants and BDE-209 were detected at high concentrations along River Aire (UK) and a risk assessment indicated significant risk for adverse effects to aquatic organisms

  17. Studies on the effect of organophosphorus insecticide (dichlorovos) on nucleic acids and its toxicity on mice

    International Nuclear Information System (INIS)

    The effect of organophosphorus insecticide dichlorovos on nucleic acids and its toxicity in mice was investigated. The studies carried out included distribution study of the insecticide in different organs of mice, its effect on acetyl cholinesterase both on blood and in brain and alkylation capability on guanine in urine and in intact DNA of mouse liver

  18. 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.

  19. Effects of Organophosphorus Flame Retardants on Spontaneous Activity in Neuronal Networks Grown on Microelectrode Arrays

    Science.gov (United States)

    EFFECTS OF ORGANOPHOSPHORUS FLAME RETARDANTS ON SPONTANEOUS ACTIVITY IN NEURONAL NETWORKS GROWN ON MICROELECTRODE ARRAYS TJ Shafer1, K Wallace1, WR Mundy1, M Behl2,. 1Integrated Systems Toxicology Division, NHEERL, USEPA, RTP, NC, USA, 2National Toxicology Program, NIEHS, RTP, NC...

  20. Comparative Toxicological Study between Exposed and Non-Exposed Farmers to Organophosphorus Pesticides

    Directory of Open Access Journals (Sweden)

    Fariba Taghavian

    2016-04-01

    Full Text Available Objective: The purpose of this work was to compare DNA damage, acetylcholinesterase (AChE activity, inflammatory markers and clinical symptoms in farmers exposed to organophosphorus pesticides to individuals that had no pesticide exposure. Materials and Methods: We conducted a cross-sectional survey with a total of 134 people. The subject group consisted of 67 farmers who were exposed to organophosphorus pesticides. The control group consisted of 67 people without any contact with pesticides matched with the subject group in terms of age, gender, and didactics. Oxidative DNA damage, the activities of AChE, interleukin-6 (IL6, IL10 and C-reactive protein (CRP in serum were measured and clinical examinations conducted in order to register all clinical signs. Results: Compared with the control group, substantial gains were observed in the farmers’ levels of oxidative DNA damage, IL10 and CRP. There was significantly less AChE activity in farmers exposed to organophosphorus pesticides. The levels of IL6 in both groups did not significantly differ. Conclusion: The outcomes show that exposure to organophosphorus pesticides may cause DNA oxidative damage, inhibit AChE activity and increase the serum levels of inflammatory markers. Using biological materials instead of chemical pesticides and encouraging the use of safety equipment by farmers are some solutions to the adverse effects of exposure to organophosphorous pesticides.

  1. DEVELOPMENT OF RISK ASSESSMENT TECHNIQUES FOR SOIL BIOAVAILABILITY AND BIOACCUMULATION OF AN ORGANOPHOSPHORUS PESTICIDE

    Science.gov (United States)

    There is increased concern about the 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 pesticides...

  2. 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...

  3. 40 CFR 798.6560 - Subchronic delayed neuro-toxicity of organophosphorus substances.

    Science.gov (United States)

    2010-07-01

    ...) Test report. In addition to the reporting requirements specified under 40 CFR part 792, subpart J the... organophosphorus substances. 798.6560 Section 798.6560 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... sacrificed. (ii) Pathology—(A) Gross necropsy. In the presence of clinical signs of delayed...

  4. Biologic monitoring of exposure to organophosphorus pesticides in 195 Italian children.

    OpenAIRE

    Aprea, C.; Strambi, M; Novelli, M T; Lunghini, L; Bozzi, N

    2000-01-01

    One hundred ninety-five 6- to 7-year-old children who lived in the municipality of Siena (Tuscany, Italy), underwent biologic monitoring to evaluate urinary excretion of several alkylphosphates that are metabolites of organophosphorus pesticides. We evaluated dimethylphosphate (DMP), dimethylthiophosphate (DMTP), dimethyldithiophosphate (DMDTP), diethylphosphate (DEP), diethylthiophosphate (DETP), and diethyldithiophosphate (DEDTP). We obtained urine samples taken in the children's schools, a...

  5. Carboxylic Esterase and Its Associations With Long-term Effects of Organophosphorus Pesticides

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To examine a) the effect of organophosphorus pesticide exposure on activity of carboxylic esterases, namely butyrylcholinesterase (BChE), carboxylesterase (CarbE) and paraoxonase (PonE); and b) the association of polymorphisms of BChE and PonE with individual genetic susceptibility to organophosphorus pesticide exposure. Methods A cross-sectional study was conducted in 75 workers exposed to organophosphorus pesticides and 100 non-exposed controls. The serum activity of these enzymes was measured. Variant forms of BCHE-K, PON-192, and PON-55 were detected. A symptom score was developed as a proxy measure of clinical outcomes. Results Activities of both BChE and CarbE were lower in exposed exposed workers with BCHE-K genotype UU (61 cases), genotype UK (12 cases) and genotype KK (2 cases) was 105.05, 84.42 activity in the exposed workers with PON-192 genotype BB (37), genotype AB (27) and genotype AA (11) was 116.8, 91.2, and 9.20. The symptom score was the highest in individuals with abnormal homozygote for each of the three gene loci. Conclusions Long-term exposure to organophosphorus pesticides can inhibit BChE and CarbE activity, but exerts no inhibitory effect on PonE activity. Different genotypes of BCHE-K, PON-192, and PON-55 may be related to the severity of adverse health effects of organophosphorus pesticide exposure. Implications of potentially higher susceptibility of workers with mutant homozygotes should be evaluated to reduce health risks.

  6. N-acetylcysteine in Acute Organophosphorus Pesticide Poisoning: A Randomized, Clinical Trial.

    Science.gov (United States)

    El-Ebiary, Ahmad A; Elsharkawy, Rasha E; Soliman, Nema A; Soliman, Mohammed A; Hashem, Ahmed A

    2016-08-01

    Organophosphorus poisoning is a major global health problem with hundreds of thousands of deaths each year. Research interest in N-acetylcysteine has grown among increasing evidence of the role of oxidative stress in organophosphorus poisoning. We aimed to assess the safety and efficacy of N-acetylcysteine as an adjuvant treatment in patients with acute organophosphorus poisoning. This was a randomized, controlled, parallel-group trial on 30 patients suffering from acute organophosphorus poisoning, who were admitted to the Poison Control Center of Tanta University Emergency Hospital, Tanta, Egypt, between April and September 2014. Interventions included oral N-acetylcysteine (600 mg three times daily for 3 days) as an added treatment to the conventional measures versus only the conventional treatment. Outcome measures included mortality, total dose of atropine administered, duration of hospitalization and the need for ICU admission and/or mechanical ventilation. A total of 46 patients were screened and 30 were randomized. No significant difference was found between both groups regarding demographic characteristics and the nature or severity of baseline clinical manifestations. No major adverse effects to N-acetylcysteine therapy were reported. Malondialdehyde significantly decreased and reduced glutathione significantly increased only in the NAC-treated patients. The patients on NAC therapy required less atropine doses than those who received only the conventional treatment; however, the length of hospital stay showed no significant difference between both groups. The study concluded that the use of N-acetylcysteine as an added treatment was apparently safe, and it reduced atropine requirements in patients with acute organophosphorus pesticide poisoning. PMID:26786042

  7. Using the Chiral Organophosphorus Derivatizing Agents for Determination of the Enantiomeric Composition of Chiral Carboxylic Acids by 31PNMR Spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Chao CHE; Zhong Ning ZHANG; Gui Lan HUANG; Xin Xing WANG; Zhao Hai QIN

    2004-01-01

    The use of chiral organophosphorus derivatizing agents prepared in situ from chiral tartrate or chiral diamine for the 31PNMR determination of the enantiomeric composition of chiral carboxylic acids is described. The method is accurate, reliable and convenient.

  8. Organophosphorus Compound DEPBT as a Coupling Reagent for Oligopeptides and Peptoids Synthesis:Studies on Its Mechanism

    Institute of Scientific and Technical Information of China (English)

    HuiLIU; YunHuaYE; 等

    2002-01-01

    Some oligopeptides and peptoids were synthesized by applying the organophosphorus compound DEPBT as a coupling reagent. D-Biotin-OOBt was obtained unexpectedly. A proposed reaction mechanism for DEPBT-mediated coupling was proved.

  9. Conformational Variability of Organophosphorus Hydrolase upon Soman and Paraoxon Binding

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Diego Eb; Lins, Roberto D.; Pascutti, Pedro G.; Lei, Chenghong; Soares, Thereza A.

    2011-12-31

    The bacterial enzyme organophosphorus hydrolase (OPH) exhibits both catalytic and substrate promiscuity. It hydrolyzes bonds in a variety of phosphotriester (P-O), phosphonothioate (P-S), phosphofluoridate (P-F) and phosphonocyanate (F-CN) compounds. However, its catalytic efficiency varies markedly for different substrates, limiting the broad-range application of OPH as catalyst in the bioremediation of pesticides and chemical war agents. In the present study, pK{sub a} calculations and multiple explicit-solvent molecular dynamics (MD) simulations were performed to characterize and contrast the structural dynamics of OPH bound to two substrates hydrolyzed with very distinct catalytic efficiencies: the nerve agent soman (O-pinacolyl-methyl-phosphonofluoridate) and the pesticide paraoxon (diethyl p-nitrophenyl phosphate). pK{sub a} calculations for the substrate-bound and unbound enzyme showed a significant pK{sub a} shift from standard values ({Delta}pK{sub a} = {+-} 3 units) for residues 254His and 275Arg. MD simulations of the doubly protonated 254His revealed a dynamic hydrogen bond network connecting the catalytic residue 301Asp via 254His to 232Asp, 233Asp, 275Arg and 235Asp, and is consistent with a previously postulated proton relay mechanism to ferry protons away from the active site with substrates that do not require activation of the leaving group. Hydrogen bonds between 301Asp and 254His were persistent in the OPH-paraoxon complex but not in the OPH-soman one, suggesting a potential role for such interaction in the more efficient hydrolysis of paraoxon over soman by OPH. These results are in line with previous mutational studies of residue 254His, which led to an increase of the catalytic efficiency of OPH over soman yet decreased its efficiency for paraoxon. In addition, comparative analysis of the molecular trajectories for OPH bound to soman and paraoxon suggests that binding of the latter facilitates the conformational transition of OPH from the

  10. Synthesis, Spectral Characterization, and Biological Evaluation of Transition Metal Complexes of Bidentate N, O Donor Schiff Bases

    Directory of Open Access Journals (Sweden)

    Sajjad Hussain Sumrra

    2014-01-01

    Full Text Available New series of three bidentate N, O donor type Schiff bases (L1–(L3 were prepared by using ethylene-1,2-diamine with 5-methyl furfural, 2-anisaldehyde, and 2-hydroxybenzaldehyde in an equimolar ratio. These ligands were further complexed with Co(II, Cu(II, Ni(II, and Zn(II metals to produce their new metal complexes having an octahedral geometry. These compounds were characterized on the basis of their physical, spectral, and analytical data. Elemental analysis and spectral data of the uncomplexed ligands and their metal(II complexes were found to be in good agreement with their structures, indicating high purity of all the compounds. All ligands and their metal complexes were screened for antimicrobial activity. The results of antimicrobial activity indicated that metal complexes have significantly higher activity than corresponding ligands. This higher activity might be due to chelation process which reduces the polarity of metal ion by coordinating with ligands.

  11. Synthesis, spectral characterization, molecular modeling, thermal study and biological evaluation of transition metal complexes of a bidentate Schiff base ligand

    Science.gov (United States)

    Chandra, Sulekh; Bargujar, Savita; Nirwal, Rita; Qanungo, Kushal; Sharma, Saroj K.

    2013-09-01

    Complexes of copper(II) and nickel(II) of general composition M(L)2X2, have been synthesized [where L = 3-Bromoacetophenone thiosemicarbazone and X = CH3COO-, Cl- and NO3-]. All the complexes were characterized by elemental analysis, magnetic moments, IR, electronic and EPR spectral studies. The ligand behaved as bidentate and coordinated through sulfur of sbnd Cdbnd S group and nitrogen atoms of sbnd Cdbnd N group. The copper(II) and nickel(II) complexes were found to have magnetic moments 1.94-2.02 BM, 2.96-3.02 BM respectively which was corresponding to one and two unpaired electrons respectively. The molar conductance of the complexes in solution of DMSO lies in the range of 10-20 Ω-1 cm2 mol-1 indicating their non-electrolytic behavior. On the basis of EPR, electronic and infrared spectral studies, tetragonal geometry has been assigned for copper(II) complexes and an octahedral geometry for nickel(II) complexes. The values of Nephelauxetic parameter β lie in the range 0.19-0.37 which indicated the covalent character in metal ligand ‘σ' bond. Synthesized ligand and its copper(II) and nickel(II) complexes have also been screened against different bacterial and fungal species which suggested that complexes are more active than the ligands in antimicrobial activities.

  12. Search for neutral leptons

    International Nuclear Information System (INIS)

    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

  13. Organochlorine and organophosphorus pesticide residues in raw buffalo milk from agroindustrial areas in Assiut, Egypt.

    Science.gov (United States)

    Shaker, Eman M; Elsharkawy, Eman E

    2015-01-01

    Raw buffalo milk samples from the agroindustrial zone in upper Egypt were analyzed for the presence of organochlorine and organophosphorus pesticides using gas chromatography-mass spectroscopy. Five organochlorine pesticides namely, alachlor, dieldrin, hexachlorobenzene, lindane and methoxychlor and three organophosphorus pesticides chlorpyrifos, malathion, and parathion-methyl were detected in the milk samples. In 44% of the samples, the concentrations of lindane and malathion residues exceeded tolerance levels set by the European Commission (EC) in 2008. In addition, the concentrations of chlorpyrifos, methoxychlor, and hexachlorobenzene residues exceeded the 2008 EC maximum residual limits (MRLs) by 33, 66, and 88% of the examined samples, respectively. However, the levels of alachlor, dieldrin, and parathion-methyl residues were below EC MRLs. The results of this study confirm the risks of pesticide residues exposure that threaten consumer health in Egypt. Thus, we recommend that pesticide residue monitoring programs be instituted in all the developing countries. PMID:25575291

  14. Supercritical fluid extraction of uranium and thorium from nitric acid solutions with organophosphorus reagents

    International Nuclear Information System (INIS)

    Extraction techniques for the recovery of uranium and transuranic elements from acid waste solutions are important in nuclear waste management. This paper examines the feasibility of extracting uranyl and thorium ions from nitric acid solutions with supercritical CO2 containing the different organophosphorus reagents. In this study, an organophosphorus reagent is dissolved in supercritical CO2 by passing the fluid through a reagent vessel placed upstream of the sample vessel in the extractor. Using TBPO or TOPO in supercritical CO2, effective extraction of uranyl and thorium ions can be achieved even in dilute HNO3 solutions, thus yielding the possibility of reducing acidic waste volumes in nuclear waste treatment. The results may form the basis of a novel extraction process for the treatment of acidified nuclear wastes, while minimizing the production of secondary wastes. 12 refs., 2 figs., 2 tabs

  15. Effect of organophosphorus pesticide on plasma transaminases and amino acids in rats

    International Nuclear Information System (INIS)

    Pesticides are added to the environment for killing or injuring some of life. Most of the chemicals that are used as pesticides are not highly selective but are generally toxic to man, and other desirable form of life. in case of organophosphorus pesticides, the problem of accumulated residual physiological effects of these pesticides has lead to some studies on their effects on animals. the present investigation was undertaken to show the effect of repeated administered doses of organophosphorus pesticide, curacron, for different periods on brain and liver free amino acids. the toxic effects of repeated oral doses of curacron were evaluated by measuring serum alkaline phosphatase, glutamic pyruvic and glutamic oxaloacetic transaminases. also radioimmunoassay technique was used to study the effect of different repeated doses of curacron at different periods on triiodothyronine (T3) and tetraiodothyronine (T4) hormones using 125I labelled triiodothyronine and 125I labelled thyroxine

  16. A screen-printed, amperometric biosensor for the determination of organophosphorus pesticides in water samples

    Institute of Scientific and Technical Information of China (English)

    Junfeng Dou; Fuqiang Fan; Aizhong Ding; Lirong Cheng; Raju Sekar; Hongting Wang; Shuairan Li

    2012-01-01

    An amperometric biosensor based on screen-printed electrodes (SPEs) was developed for the determination of organophosphorus pesticides in water samples.The extent of acetylcholinesterase (AChE) deactivation was determined and quantified for pesticideconcentrations in water samples.An enzyme immobilization adsorption procedure and polyacrylamide gel matrix polymerization were used for fabrication of the biosensor,with minimal losses in enzyme activity.The optimal conditions for enzyme catalytic reaction on the SPEs surfaces were acetylthiocholine chloride (ATChC(1)) concentration of 5 mmol/L,pH 7 and reaction time of 4 min.The detectionlimits for three organophosphorus pesticides (dichlorvos,monocrotophs and parathion) were in the range of 4 to 7 μg/L when an AChE amount of 0.1 U was used for immobilization.

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

    OpenAIRE

    Korrapati Kotinagu; Nelapati Krishnaiah

    2015-01-01

    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...

  18. Nanomaterials - Acetylcholinesterase Enzyme Matrices for Organophosphorus Pesticides Electrochemical Sensors: A Review

    OpenAIRE

    Shen-Ming Chen; Arun Prakash Periasamy; Yogeswaran Umasankar

    2009-01-01

    Acetylcholinesterase (AChE) is an important cholinesterase enzyme present in the synaptic clefts of living organisms. It maintains the levels of the neurotransmitter acetylcholine by catalyzing the hydrolysis reaction of acetylcholine to thiocholine. This catalytic activity of AChE is drastically inhibited by trace amounts of organophosphorus (OP) pesticides present in the environment. As a result, effective monitoring of OP pesticides in the environment is very desirable and has been done su...

  19. Assessing Exposure to Organophosphorus Pesticides by Biomonitoring in Epidemiologic Studies of Birth Outcomes

    OpenAIRE

    Needham, Larry L.

    2005-01-01

    For epidemiologic studies that evaluate the relation between potential exposures to environmental chemicals and adverse outcomes, accurate assessments of exposures and health outcomes are needed. Three prospective cohort studies recently evaluated the relation between exposure, as assessed by biomonitoring, of pregnant women to organophosphorus pesticides and several birth outcomes. Here these three studies are compared in terms of the exposure scenarios and exposure assessments. The primary ...

  20. 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

  1. An efficient method for synthesis of organophosphorus compounds in aqueous media

    Institute of Scientific and Technical Information of China (English)

    Reza Heydari; Malek Taher Maghsoodlou; Razieh Nejat Yami

    2009-01-01

    A convenient and facile one-pot synthesis of stable phosphorus ylides and 1,4-diionic organophosphorus compounds is reported by the reaction of triphenyiphosphine, dialkylacetylenedicarboxylates and N-H, C-H or S-H acids in the presence of poly-ethyleneglycol (PEG), β-cyclodextrin (β-CD), glycerine (Gly) or ethyleneglycol (EG) in water. This methodology is of interest due to the use of water as a solvent, thus minimizing the cost operational hazards, and environmental pollution.

  2. Study on the toxic effect of the mixture of organophosphorus pesticide on perinatal rats

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To observe the toxic effect of the mixture of organophosphorus pesticide (MOP) on maternal rats and on the growth and development of their offspring. Methods Totally 40 Sprague-Dawley pregnant rats were randomly divided into three MOP dose groups and one control to which their offspring would be assigned. The experimental dosage of MOP and distilled water were administered orally starting on gestation day 15 and continued for 35 days. The physical development indices and the learning ability of F1...

  3. 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

  4. STUDY OF CARBONYLATION OF METHANOL TO ACETIC ACID AND ACETIC ANHYDRIDE OVER A BIDENTATE POLYMER BOUND CIS-DICARBONYLRHODIUM COMPLEX AS CATALYST

    Institute of Scientific and Technical Information of China (English)

    WANG Xiaojun; LIU Zhongyang; PAN Pinglai; YUAN Guoqing

    1996-01-01

    Copolymer of 2-vinylpyridine and vinylacetate coordinated with dicarbonylrhodium used as a catalyst for carbonylation of methanol to acetic acid and anhydride has been studied. The structural characteristics of the copolymer ligand and complex, and the influences of the reaction conditions on the carbonylation catalyzed by this polymer complex have been investigated. In comparison with small molecule catalyst of Rh complex, the bidentate copolymer coordinated complex has better thermal stability. The reaction mechanism of the carbonylation reaction is also illustrated.

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

    International Nuclear Information System (INIS)

    A few Zn(II), Cd(II) and Hg(II) complexes of the bis(bidentate) Schiff bases derived from p-phenylenediamine and salicylaldehyde (H2 Salpphen), and o-phenylenediamine and o-vanillin (H2 Vanophen), of the type MCl2.H2L(H2L = H2 Salpphen or H2 Vanophen) have been synthesised. The complexes have been characterized by elemental analysis, infrared, 1H and 13C NMR and mass spectra. (author)

  6. Entropy-Driven Conformational Control of α,ω-Difunctional Bidentate-Dithiol Azo-Based Adsorbates Enables the Fabrication of Thermally Stable Surface-Grafted Polymer Films.

    Science.gov (United States)

    Lee, Han Ju; Jamison, Andrew C; Lee, T Randall

    2016-06-22

    Thermally stable radical initiator monolayers were prepared from uniquely designed α,ω-difunctional adsorbates with bidentate headgroups for the growth of nanoscale polymer films on metal surfaces. The length of the spacer separating the bidentate headgroups was varied to afford 4,4'-(diazene-1,2-diyl)bis(N-(16-(3,5-bis(mercaptomethyl)phenoxy)hexadecyl)-4-cyanopentanamide) (B16), 4,4'-(diazene-1,2-diyl)bis(N-(16-(3,5-bis(mercapto-methyl)phenoxy)decyl)-4-cyanopentanamide) (B10), and 4,4'-(diazene-1,2-diyl)bis(N-(4-(3,5-bis(mercaptomethyl)phenoxy)butyl)-4-cyanopentanamide) (B4). The structural features of the self-assembled monolayers (SAMs) derived from B16, B10, and B4 were characterized by X-ray photoelectron spectroscopy (XPS), ellipsometry, and polarization modulation infrared reflection-absorption spectroscopy (PM-IRRAS) and compared to those derived from an analogous α,ω-difunctional adsorbate with monodentate headgroups, 4,4'-(diazene-1,2-diyl)bis(4-cyano-N-(16-mercaptohexadecyl)pentanamide (M). These studies demonstrate that the conformation (i.e., hairpin vs standing up) of the bidentate initiator adsorbates on gold surfaces was easily controlled by adjusting the concentration of the adsorbates in solution. The results of solution-phase thermal desorption tests revealed that the radical initiator monolayers generated from B16, B10, and B4 exhibit an enhanced thermal stability when compared to those generated from M. Furthermore, a study of the growth of polymer films was performed to evaluate the utility of these new bidentate adsorbate SAMs as film-development platforms for new functional materials and devices. Specifically, surface-grafted polystyrene films were successfully generated from SAMs derived from B16. In contrast, attempts to grow polystyrene films from SAMs derived from M under a variety of analogous conditions were unsuccessful. PMID:27219525

  7. Integrated microwave processing system for the extraction of organophosphorus pesticides in fresh vegetables.

    Science.gov (United States)

    Wu, Lijie; Song, Ying; Hu, Mingzhu; Xu, Xu; Zhang, Hanqi; Yu, Aimin; Ma, Qiang; Wang, Ziming

    2015-03-01

    A simple and efficient integrated microwave processing system (IMPS) was firstly assembled and validated for the extraction of organophosphorus pesticides in fresh vegetables. Two processes under microwave irradiation, dynamic microwave-assisted extraction (DMAE) and microwave-accelerated solvent elution (MASE), were integrated for simplifying the pretreatment of the sample. Extraction, separation, enrichment and elution were finished in a simple step. The organophosphorus pesticides were extracted from the fresh vegetables into hexane with DMAE, and then the extract was directly introduced into the enrichment column packed with active carbon fiber (ACF). Subsequently, the organophosphorus pesticides trapped on the ACF were eluted with ethyl acetate under microwave irradiation. No further filtration or cleanup was required before analysis of the eluate by gas chromatography-mass spectrometry. Some experimental parameters affecting extraction efficiency were investigated and optimized, such as microwave output power, kind and volume of extraction solvent, extraction time, amount of sorbent, elution microwave power, kind and volume of elution solvent, elution solvent flow rate. Under the optimized conditions, the recoveries were in the range of 71.5-105.2%, and the relative standard deviations were lower than 11.6%. The experiment results prove that the present method is a simple and effective sample preparation method for the determination of pesticides in solid samples. PMID:25618681

  8. Induction of plasma acetylcholinesterase activity in mice challenged with organophosphorus poisons

    International Nuclear Information System (INIS)

    The restoration of plasma acetylcholinesterase activity in mice following inhibition by organophosphorus pesticides and nerve agents has been attributed to synthesis of new enzyme. It is generally assumed that activity levels return to normal, are stable and do not exceed the normal level. We have observed over the past 10 years that recovery of acetylcholinesterase activity levels in mice treated with organophosphorus agents (OP) exceeds pretreatment levels and remains elevated for up to 2 months. The most dramatic case was in mice treated with tri-cresyl phosphate and tri-ortho-cresyl phosphate, where plasma acetylcholinesterase activity rebounded to a level 250% higher than the pretreatment activity. The present report summarizes our observations on plasma acetylcholinesterase activity in mice treated with chlorpyrifos, chlorpyrifos oxon, diazinon, tri-ortho-cresyl phosphate, tri-cresyl phosphate, tabun thiocholine, parathion, dichlorvos, and diisopropylfluorophosphate. We have developed a hypothesis to explain the excess acetylcholinesterase activity, based on published observations. We hypothesize that acetylcholinesterase activity is induced when cells undergo apoptosis and that consequently there is a rise in the level of plasma acetylcholinesterase. - Highlights: → Acetylcholinesterase activity is induced by organophosphorus agents. → AChE induction is related to apoptosis. → Induction of AChE activity by OP is independent of BChE.

  9. Degradation of organophosphorus pesticides and their transformation products in estuarine waters

    International Nuclear Information System (INIS)

    The degradation of 10 organophosphorus pesticides in natural estuarine waters was studied. Estuarine water samples were spiked with organophosphorus pesticides at 50 μg/L level and were placed into 2-L Pyrexflasks being exposed outdoor to ambient sunlight and temperature. A sample of 10-75 mL of water was collected every week for analysis during a period of 5-6 weeks from January to March. The analytical determinations were performed by solid-phase extraction (SPE) with C18 Emporedisks followed by GC-NPD and GC-MS with EI and by on-line SPE using PLRP-s exchangeable cartridges (Prospekt) followed by LC-DAD and LC-thermospray MS in PI mode. Five organophosphorus pesticides were stable for less than 1 week (disulfoton, fenamiphos, fenthion, malathion, and temephos), others had a half-life of ca. 1 week (chlorpyrifos-methyl, methidathion, and diazinon), and the rest showed a half-life of ca. 10 days (isofenphos and pyridafenthion). The half-life of three pesticidetransformation products: disulfoton sulfoxide, disulfoton sulfone, and fenthion sulfoxide varied from 7 to 12 days

  10. 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.

  11. Mechanism of the selective toxicity of organophosphorus compounds in the armyworm, Leucania separata Walker, 1

    International Nuclear Information System (INIS)

    As the first step to clarify the selective toxicity of four organophosphorus compounds in the armyworm, L. separata, the bioassay and in vitro anticholinesterase activity were studied by use of acetyl [1-14C]-choline chloride. Comparing their relative toxicities by LD50 Values, it was found that the toxic index of fenitrothion, phenthoate and diazinon to methyl parathion were 297, 383 and 1080 respectively. The results of in vitro anticholinesterase activity with oxon isomers of the compounds were orderly accomplished; phenthoate-oxon > methyl paraoxon > diaz-oxon > fenitroxon. The correlation between the toxicity of the organophosphorus compounds and the anticholinesterase activities of their oxygen analogs was examined. Statistically it seems that there is poor correlation between toxicity and the antiactivity data among 4 compounds but positive correlation among 3 compounds, methyl parathion, fenitrothion and diazinon. Unexpectedly, phenthoate was an exception where its antiactivity was highest, exhibiting about 5 times higher inhibitory activity whereas it was 3.8 times less toxic compound. This might indicate that the mechanism of selective toxicity of phenthoate against the armyworm is attributable to the different feature from those of other 3 organophosphorus compounds. (Kobatake, H.)

  12. 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.

  13. A niche for neutrality.

    Science.gov (United States)

    Adler, Peter B; Hillerislambers, Janneke; Levine, Jonathan M

    2007-02-01

    Ecologists now recognize that controversy over the relative importance of niches and neutrality cannot be resolved by analyzing species abundance patterns. Here, we use classical coexistence theory to reframe the debate in terms of stabilizing mechanisms (niches) and fitness equivalence (neutrality). The neutral model is a special case where stabilizing mechanisms are absent and species have equivalent fitness. Instead of asking whether niches or neutral processes structure communities, we advocate determining the degree to which observed diversity reflects strong stabilizing mechanisms overcoming large fitness differences or weak stabilization operating on species of similar fitness. To answer this question, we propose combining data on per capita growth rates with models to: (i) quantify the strength of stabilizing processes; (ii) quantify fitness inequality and compare it with stabilization; and (iii) manipulate frequency dependence in growth to test the consequences of stabilization and fitness equivalence for coexistence. PMID:17257097

  14. Ultracold Neutral Plasmas

    OpenAIRE

    Killian, T. C.; Pattard, T.; Pohl, T.; Rost, J. M.

    2006-01-01

    Ultracold neutral plasmas, formed by photoionizing laser-cooled atoms near the ionization threshold, have electron temperatures in the 1-1000 kelvin range and ion temperatures from tens of millikelvin to a few kelvin. They represent a new frontier in the study of neutral plasmas, which traditionally deals with much hotter systems, but they also blur the boundaries of plasma, atomic, condensed matter, and low temperature physics. Modelling these plasmas challenges computational techniques and ...

  15. The neutral comet assay

    International Nuclear Information System (INIS)

    The single-cell gel electrophoresis (or comet) assay is a rapid and sensitive fluorescence microscopic method that is used for the detection of DNA damage at the individual cell level. Comet assay under neutral conditions allows the detection of DNA double-strand breaks, considered to the biologically relevant radiation-induced lesion. In this report we describe modifications of the neutral comet method and its use for studying DNA damage and its repair in irradiated human lymphocytes. (author)

  16. Probabilistic assessment of the cumulative dietary acute exposure of the population of Denmark to organophosphorus and carbamate pesticides

    DEFF Research Database (Denmark)

    Jensen, Bodil Hamborg; Petersen, Annette; Christensen, Tue

    2009-01-01

    Organophosphorus and carbamate pesticides are acetylcholinesterase-inhibiting pesticides and as such have a common mode of action. We assessed the cumulative acute exposure of the population of Denmark to 25 organophosphorus and carbamate pesticide residues from the consumption of fruit, vegetables...... and cereals. The probabilistic approach was used in the assessments. Residue data obtained from the Danish monitoring programme carried out in the period 2004-2007, which included 6704 samples of fruit, vegetables and cereals, were used in the calculations. Food consumption data were obtained from...... the nationwide dietary survey conducted in 2000-2002. Contributions from 43 commodities were included in the calculations. We used the relative potency factor (RPF) approach to normalize the toxicity of the various organophosphorus and carbamate pesticides to the two index compounds chlorpyriphos...

  17. Determination of organophosphorus pesticides in ginseng by carbon nanotube envelope-based solvent extraction combined with ultrahigh-performance liquid chromatography mass spectrometry.

    Science.gov (United States)

    Su, Rui; Li, Dan; Wang, Xinghua; Yang, Hongmei; Shi, Xiaoyu; Liu, Shuying

    2016-06-01

    A miniature extraction envelope containing multiwall carbon nanotubes, diatomite, neutral alumina, and anhydrous magnesium sulfate was developed for the solvent extraction of organophosphorus pesticides in dried ginseng. After the powder of dried ginseng sample was introduced into the envelope, the envelope was heat sealed and sonicated in acetonitrile for the extraction and clean-up of analytes. The resulting extracts were analyzed by an ultrahigh-performance liquid chromatograph with an electrospray ion source and a quadrupole orbitrap mass spectrometer (UHPLC-ESI/Q-Orbitrap MS) under target-MS(2) mode, and the analytes were quantified by matrix-match calibration. Finally, the simultaneous identification and quantification of 19 pesticide residues were carried out by the present method. It is noteworthy that in this method the processes of extraction and clean-up for the analytes could be carried out and accomplished in one step. The recoveries and relative standard deviations (RSDs) of analytes were in the range of 82.6-110.8% and 1.0-10.6%, respectively. The limits of detection (LODs) and quantification (LOQs) for analytes were determined to be 0.08-0.29μgkg(-1) and 0.26-0.98μgkg(-1), respectively. Several pesticide residues investigated in this study were found in 4 real samples, with the concentrations lower than the maximum residue limit (0.050mgkg(-1)) established by European Union. PMID:27093495

  18. Antimalarial activity of ruthenium(II) and osmium(II) arene complexes with mono- and bidentate chloroquine analogue ligands.

    Science.gov (United States)

    Ekengard, Erik; Glans, Lotta; Cassells, Irwin; Fogeron, Thibault; Govender, Preshendren; Stringer, Tameryn; Chellan, Prinessa; Lisensky, George C; Hersh, William H; Doverbratt, Isa; Lidin, Sven; de Kock, Carmen; Smith, Peter J; Smith, Gregory S; Nordlander, Ebbe

    2015-11-28

    Eight new ruthenium and five new osmium p-cymene half-sandwich complexes have been synthesized, characterized and evaluated for antimalarial activity. All complexes contain ligands that are based on a 4-chloroquinoline framework related to the antimalarial drug chloroquine. Ligands HL(1-8) are salicylaldimine derivatives, where HL(1) = N-(2-((2-hydroxyphenyl)methylimino)ethyl)-7-chloroquinolin-4-amine, and HL(2-8) contain non-hydrogen substituents in the 3-position of the salicylaldimine ring, viz. F, Cl, Br, I, NO2, OMe and (t)Bu for HL(2-8), respectively. Ligand HL(9) is also a salicylaldimine-containing ligand with substitutions in both 3- and 5-positions of the salicylaldimine moiety, i.e. N-(2-((2-hydroxy-3,5-di-tert-butylphenyl)methyl-imino)ethyl)-7-chloroquinolin-4-amine, while HL(10) is N-(2-((1-methyl-1H-imidazol-2-yl)methylamino)ethyl)-7-chloroquinolin-4-amine) The half sandwich metal complexes that have been investigated are [Ru(η(6)-cym)(L(1-8))Cl] (Ru-1-Ru-8, cym = p-cymene), [Os(η(6)-cym)(L(1-3,5,7))Cl] (Os-1-Os-3, Os-5, and Os-7), [M(η(6)-cym)(HL(9))Cl2] (M = Ru, Ru-HL(9); M = Os, Os-HL(9)) and [M(η(6)-cym)(L(10))Cl]Cl (M = Ru, Ru-10; M = Os, Os-10). In complexes Ru-1-Ru-8 and Ru-10, Os-1-Os-3, Os-5 and Os-7 and Os-10, the ligands were found to coordinate as bidentate N,O- and N,N-chelates, while in complexes Ru-HL(9) and Os-HL(9), monodentate coordination of the ligands through the quinoline nitrogen was established. The antimalarial activity of the new ligands and complexes was evaluated against chloroquine sensitive (NF54 and D10) and chloroquine resistant (Dd2) Plasmodium falciparum malaria parasite strains. Coordination of ruthenium and osmium arene moieties to the ligands resulted in lower antiplasmodial activities relative to the free ligands, but the resistance index is better for the ruthenium complexes compared to chloroquine. Overall, osmium complexes appeared to be less active than the corresponding ruthenium complexes. PMID:26491831

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

    International Nuclear Information System (INIS)

    Organophosphorus compounds (OPCs) and stable isotope ratios (δ13C and δ15N) 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 δ15N, 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joon-Woo [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Senior Research Fellow Center, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Isobe, Tomohiko, E-mail: t.isobe@agr.ehime-u.ac.jp [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Senior Research Fellow Center, Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan); Chang, Kwang-Hyeon [Department of Environmental Science and Engineering, Kyung Hee University, Seochen-dong 1, Giheung-gu, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of); Amano, Atsuko [National Institute of Advanced Industrial Science and Technology, Tsukuba 305-8567 (Japan); Maneja, Rommel H.; Zamora, Peter B.; Siringan, Fernando P. [Marine Science Institute, University of the Philippines, Diliman, Quezon City 1101 (Philippines); Tanabe, Shinsuke [Center for Marine Environmental Studies (CMES), Ehime University, 2-5 Bunkyo-cho, Matsuyama 790-8577 (Japan)

    2011-12-15

    Organophosphorus compounds (OPCs) and stable isotope ratios ({delta}{sup 13}C and {delta}{sup 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 {mu}g/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 {delta}{sup 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 {mu}g/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.

  1. Biochemical alterations in the rat following exposure to the organophosphorus insecticide cyanox

    International Nuclear Information System (INIS)

    Cyanox is an organophosphorus insecticide with an oral LD50 of 580 mg/kg for male rats. For the assessment of the subacute toxicity, two groups of male rats were treated with 11.6 and 29 mg/kg/day of the pesticide for 28 days. Animals were sacrificed on day 2,4,10,16,22 and 8. The compound significantly altered plasma protein electrophoretic pattern, brain and erythrocytes acetylcholinesterase (AchE), serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), serum alkaline phosphatase (ALP), creatinine, inorganic phosphorus, triiodothyronine (T3) and thyroxine (T4)

  2. Some liver and brain disorders induced by anachronistical organophosphorus pesticide in rats subjected to gamma irradiation

    International Nuclear Information System (INIS)

    The present study deals with the changes produced in liver, brain and serum of animals subjected to cumulative doses up to 7 Gy and/or oral administration of 7.5 mg/kg body weight of the organophosphorus pesticide tamaron. The data obtained revealed that treatment with tamaron or exposure to radiation induced highly highly significant inhibition of cholinesterase activity in brain, liver and serum. Radiation exposure alone caused significant inhibition of cholinesterase in liver and serum,whereas, no change was observed in brain. These results indicated that the study of cholinesterase activity in serum is of great use in diagnosing liver disorder

  3. Application of brain cholinesterase reactivation to differentiate between organophosphorus and carbamate pesticide exposure in wild birds

    Science.gov (United States)

    Smith, M.R.; Thomas, N.J.; Hulse, C.

    1995-01-01

    Brain cholinesterase activity was measured to evaluate pesticide exposure in wild birds. Thermal reactivation of brain cholinesterase was used to differentiate between carbamate and organophosphorus pesticide exposure. Brain cholinesterase activity was compared with gas chromatography and mass spectrometry of stomach contents. Pesticides were identified and confirmed in 86 of 102 incidents of mortality from 29 states within the USA from 1986 through 1991. Thermal reactivation of cholinesterase activity was used to correctly predict carbamates in 22 incidents and organophosphates in 59 incidents. Agreement (P < 0.001) between predictions based on cholinesterase activities and GC/MS results was significant.

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

    Directory of Open Access Journals (Sweden)

    Michael Eddleston

    2009-06-01

    Full Text Available BACKGROUND: 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. METHODS AND FINDINGS: 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

  5. 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.

  6. Recovery of cholinesterase activity in five avian species exposed to dicrotophos, an organophosphorus pesticide

    Science.gov (United States)

    Fleming, W.J.; Grue, C.E.

    1981-01-01

    The responses of brain and plasma cholinesterase (ChE) activities were examined in mallard ducks, bobwhite quail, barn owls, starlings, and common grackles given oral doses of dicrotophos, an organophosphorus insecticide. Up to an eightfold difference in response of brain ChE activity to dicrotophos was found among these species. Brain ChE activity recovered to within 2 SD of normal within 26 days after being depressed 55 to 64%. Recovery of brain ChE activity was similar among species and followed the model Y = a + b (log10X).

  7. Organophosphorus insecticide induced decrease in plasma luteinizing hormone concentration in white-footed mice

    Science.gov (United States)

    Rattner, B.A.; Michael, S.D.

    1985-01-01

    Oral intubation of 50 and 100 mg/kg acephate inhibited brain acetylcholinesterase (AChE) activity by 45% and 56%, and reduced basal luteinizing hormone (LH) concentration by 29% and 25% after 4 h in white-footed mice (Peromyscus leucopus noveboracensis). Dietary exposure to 25, 100, and 400 ppm acephate for 5 days substantially inhibited brain AChE activity, but did not affect plasma LH concentration. These preliminary findings suggest that acute exposure to organophosphorus insecticides may affect LH secretion and possibly reproductive function.

  8. Extraction studies of Am(III) and Nd(III) by diphenyl-N, N di isobutyl carbamoyl methyl phosphine oxide (DφCMPO)

    International Nuclear Information System (INIS)

    The neutral bidentate organophosphorus extractant, diphenyl N,N di isobutyl carbamoyl methyl phosphine oxide (DφCMPO) has been synthesised and characterised. Extraction studies of Am(III) at various nitric acid concentrations were studied and reported. Extraction chromatographic column runs with Nd(III) using DφCMPO loaded Amberlite/XAD7 were carried out for the first time and the results are reported. (author)

  9. Ultracold neutral plasmas.

    Science.gov (United States)

    Killian, Thomas C

    2007-05-01

    Ultracold neutral plasmas occupy an exotic regime of plasma physics in which electrons form a swarming, neutralizing background for ions that sluggishly move in a correlated manner. Strong interactions between the charged particles give rise to surprising dynamics such as oscillations of the average kinetic energy during equilibration and extremely fast recombination. Such phenomena offer stimulating and challenging problems for computational scientists, and the physics can be applied to other environments, such as the interior of gas giant planets and plasmas created by short-pulse laser irradiation of solid, liquid, and cluster targets. PMID:17478712

  10. 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)

    Consideration is given to the method for determination of basicity of neutral organophosphorus compounds of XGZP=0 type (X, G, Z=C4H9, C8H17, C6H5). The method is based on change of chemical shift of phosphorus-31 nuclei in two-phase extraction system depending on acidity function HO, HA, HPO. It is shown that the method can be used for evaluation and forecasting of phosphine oxide ability in the processes of UO2SO4 solvent extraction from aqueous solutions of sulfuric acid

  11. ITER neutral beam system

    International Nuclear Information System (INIS)

    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)

  12. CO2-Neutral Fuels

    Science.gov (United States)

    Goede, Adelbert; van de Sanden, Richard

    2016-06-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy efficiency.

  13. Issues in neutral currents

    International Nuclear Information System (INIS)

    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.)

  14. Bleach Neutralizes Mold Allergens

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    Researchers at National Jewish Medical and Research Center have demonstrated that dilute bleach not only kills common household mold, but may also neutralize the mold allergens that cause most mold-related health complaints. The study, published in the Journal of Allergy and Clinical Immunology, is the first to test the effect on allergic…

  15. 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...

  16. Draft Genome Sequence of the Organophosphorus Compound-Degrading Burkholderia zhejiangensis Strain CEIB S4-3

    OpenAIRE

    Hernández-Mendoza, Armando; Martínez-Ocampo, Fernando; Lozano-Aguirre Beltrán, Luis Fernando; Popoca-Ursino, Elida Carolina; Ortiz-Hernández, Laura; Sánchez-Salinas, Enrique; Dantán-González, Edgar

    2014-01-01

    Burkholderia species are widely distributed in the environment. A Burkholderia zhejiangensis strain was isolated from pesticide-contaminated soil from an agricultural field in Mexico and identified as an organophosphorus compound-degrading bacterium. In this study, we report the draft genome sequence of Burkholderia zhejiangensis strain CEIB S4-3.

  17. Transformation of Organophosphorus Pesticides in the Presence of Aqueous Chlorine: Kinetics, Pathways, and Structure-Activity Relationships

    Science.gov (United States)

    The fate of organophosphorus (OP) pesticides in the presence of aqueous chlorine was investigated under simulated drinking water treatment conditions. Intrinsic rate coefficients were found for the reaction of hypochlorous acid (kHOCl,OP) and hypochlorite ion (kOCl,OP) for eight...

  18. 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 ...

  19. Determination of polar organophosphorus pesticides in vegetables and fruits using liquid chromatography with tandem mass spectrometry: Selection of extraction solvent

    NARCIS (Netherlands)

    Mol, H.G.J.; Dam, R.C.J. van; Steijger, O.M.

    2003-01-01

    A method based on liquid chromatography (LC)-mass spectrometry (MS)/MS was developed for sensitive determination of a number of less gas chromatography (GC)-amenable organophosphorus pesticides (OPs; acephate, methamidophos, monocrotophos, omethoate, oxydemeton-methyl and vamidothion) in cabbage and

  20. Nursing experience of organophosphorus pesticide poisoning%有机磷农药中毒护理体会

    Institute of Scientific and Technical Information of China (English)

    董丽仙

    2015-01-01

    Due to the use or an improper protection of organophosphorus pesticide, poisoning events occur. Organophosphorus pesticide poisoning harm for human life is bigger, the rescue is not timely mortality is higher. Agricultural production in the process of organophosphorus pesticide use many, poisoning, and often happen, so we must strengthen the organophosphorus pesticide poisoning the clinical diagnosis and treatment and nursing of patients, and improve the success rate of rescue and reduce mortality.%有机磷农药的使用或防护不当致中毒事件时有发生,有机磷农药中毒对人的生命危害较大,抢救不及时死亡率较高,我县是农业县,农业生产过程中有机磷农药使用相对多,中毒事件时有发生,必须加强对有机磷农药中毒患者的临床诊治与护理,提高患者抢救成功率,降低死亡率。

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

    International Nuclear Information System (INIS)

    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

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

    International Nuclear Information System (INIS)

    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)

  3. Organophosphorus pesticides detection using broad-specific single-stranded DNA based fluorescence polarization aptamer assay.

    Science.gov (United States)

    Zhang, Cunzheng; Wang, Li; Tu, Zhui; Sun, Xing; He, Qinghua; Lei, Zhaojing; Xu, Chongxin; Liu, Yuan; Zhang, Xiao; Yang, Jingyi; Liu, Xianjin; Xu, Yang

    2014-05-15

    An approach is developed to detect the organophosphorus pesticides via competitive binding to a recombinant broad-specificity DNA aptamer with a molecular beacon (MB), the binding of the MB to the aptamer results in the activation of a fluorescent signal, which can be measured for pesticide quantification. Aptamers selected via the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) were structurally modified and truncated to narrow down the binding region of the target, which indicated that loops of the aptamer contributed different functions for different chemical recognition. Thereafter, a variant fused by two different minimum functional structures, was clarified with broad specificity and increased affinity. Further molecular docking and molecular dynamics simulations was conducted to understand the molecular interaction between DNA structure and chemicals. 3D modeling revealed a hot spot area formed by 3 binding sites, forces including hydrogen bonds and van der Waals interactions appear to play a significant role in enabling and stabilizing the binding of chemicals. Finally, an engineered aptamer based approach for the detection of organophosphorus pesticides was successfully applied in a test using a real sample, the limit of quantification (LOQ) for phorate, profenofos, isocarbophos, and omethoate reached 19.2, 13.4, 17.2, and 23.4 nM (0.005 mg L(-1)), respectively. PMID:24384262

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

    Science.gov (United States)

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

    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. PMID:25976884

  5. Organophosphorus Pesticide Extraction and Cleanup from Soils and Measurement Using GC-NPD

    Institute of Scientific and Technical Information of China (English)

    WANG Li-Gang; JIANG Xin; MAO Ying-Ming; ZHAO Zhen-Hua; BIAN Yong-Rong

    2005-01-01

    The objectives of this study were to optimize instrumental parameters and conditions for analysis of selected organophosphorus pesticides (OPPs) by gas chromatography (GC) with nitrogen-phosphorus detection (NPD) (GC-NPD); to select an appropriate solvent system; to conduct a comparison of sonication and shaking extractions; and to select an appropriate procedure for extracting organophosphorus pesticides from soils. Procedure Ⅰ consisted of n-hexane or petroleum ether together with acetone used as solvents, while Procedure Ⅱ contained several solvents including acetone,methanol, dichloromethane, and n-hexane or petroleum ether. Experimental results indicated that a mixture of petroleum ether/acetone (2:1, v/v) could be used in place of n-hexane/acetone (2:1, v/v) as it was a less expensive solvent system.In addition, shaking under a water bath at 20 ℃ was more effective than sonication. Also, Procedure Ⅰ was more effective,safer, and more timesaving than Procedure Ⅱ. Procedure I was applied to three soil types of different organic matter content, with recoveries of the OPPs from the yellow-brown soils, which had a higher organic matter content, being lower than those from the yellow and red soils.

  6. The Influencing Factors of Disposable Acetylcho linesterase Biosensor for in Situ Detection of Organophosphorus Pesticide

    Institute of Scientific and Technical Information of China (English)

    Xiaowen Xu; Xiaohao Wang; Fei Tang; Zhaoying Zhou

    2006-01-01

    An amperometric biosensor based on acetylcholinesterase (AChE) is assembled by simple adsorption of the AChE on 7,7,8,8-tetracyanoquinodimethane (TCNQ) modified screen-printed electrodes. This biosensor is used to detect the inhibitory effect of organophosphorus pesticides on AChE activity. The detection of organophosphorus pesticides is done with acetylthiocholine chloride (ATCh) as substrate. In order to obtain the optimized response to substrate, the influencing factors of the biosensor are investigated, including temperature, pH, incubation time, substrate concentration and AChE concentration.The measurements were performed after inhibition by immersing the enzyme electrode into the parathion methyl solution.Under the optimized conditions, that is, 500 U/ml AChE concentration, pH 7.2, 10 min incubation time, 2 mmol/L substrate concentration and temperature of 37℃, from 5×10-8 mol/L to 5×10-5 mol/L is close to linear (regression equation:y(%)=124.055+15.7991gx, R2=0.99644), which corresponds to 8.7%~56.1% AChE inhibition. With the optimized conditions,the lowest detectable amount of parathion methyl is 13 × 10-9.

  7. Application of Current Hapten in the Production of Broad Specificity Antibodies Against Organophosphorus Pesticides

    Institute of Scientific and Technical Information of China (English)

    LIU Xian-jin; YAN Chun-rong; LIU Yuan; YU Xiang-yang; ZHANG Cun-zheng

    2008-01-01

    Diethylphosphono acetic acid (DPA) was used as a current hapten to generate broad specificity polycolonal antibodies against a group of organophosphorus pesticides. Six New Zealand white rabbits were immunized with immunogens synthesized by the active ester method (AEM) or 1-ethyl-3-(3-dimethylaminopropyl)-carbodimide method (EDC). The titers of antisera reached 25 600 by AEM and 6 400 by EDC, respectively. Polyclonal antibodies raised against DPA were screened and selected for the competitive indirect enzyme-linked immunosorbent assay (CI-ELISA). A CI-ELISA for DPA was developed with a detection limit of 3.536 ng mL-1 and an I50 value of 0.182 ug mL-1. The assay specificity was evaluated by obtaining competitive curves for several structurally related compounds as competitors. The antiserum showed high affinities to chlorpyrifos, diazinon, omethoate, parathion-ethyl and profenofos with I50 of 0.12, 0.15, 0.21, 0.88, 0.97 and 2.5 ug mL-1, respectively. The results indicate that the assay could be a screening tool for quantitation and semi-quantitation determination of the above former five organophosphorus pesticides.

  8. 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.

  9. 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.

  10. Liquid-phase microextraction of organophosphorus pesticides using supramolecular solvent as a carrier for ferrofluid.

    Science.gov (United States)

    Zohrabi, Parvin; Shamsipur, Mojtaba; Hashemi, Mahdi; Hashemi, Beshare

    2016-11-01

    A liquid-phase microextraction based on application of supramolecular solvent as a carrier for ferrofluid has been developed for the extraction and determination of three organophosphorus pesticides (OPPs). The ferrofluid was produced from combination of oleic acid coated magnetic particles and supramolecular solvent as the extractant solvent. Ferrofluid can be attracted by a magnet, and no centrifugation step was needed for phase separation. A response surface methodology (RSM) based on central composite design (CCD) was used for efficient optimization of the main variables in the extraction procedure. Under the optimum experimental conditions, the calibration curves found to be linear in the range of 0.5-400µgL(-1) with correlation coefficients ranging from 0.9967 to 0.9984. The intra-day and inter-day precision (RSD %) for 100 and 200µgL(-1) of each pesticides were in the range of 2.0-5.3% and 2.6-5.7%, respectively. The limit of detection (S/N=3), ranged from 0.1 to 0.35μgL(-1). The proposed method was successfully applied to the extraction and determination of organophosphorus pesticide residues in water and fruit juice samples. PMID:27591622

  11. Formation of ternary complexes with MgATP: effects on the detection of Mg2+ in biological samples by bidentate fluorescent sensors.

    Science.gov (United States)

    Schwartz, Sarina C; Pinto-Pacheco, Brismar; Pitteloud, Jean-Philippe; Buccella, Daniela

    2014-03-17

    Fluorescent indicators based on β-keto-acid bidentate coordination motifs display superior metal selectivity profiles compared to current o-aminophenol-N,N,O-triacetic acid (APTRA) based chelators for the study of biological magnesium. These low denticity chelators, however, may allow for the formation of ternary complexes with Mg(2+) and common ligands present in the cellular milieu. In this work, absorption, fluorescence, and NMR spectroscopy were employed to study the interaction of turn-on and ratiometric fluorescent indicators based on 4-oxo-4H-quinolizine-3-carboxylic acid with Mg(2+) and ATP, the most abundant chelator of biological magnesium, thus revealing the formation of ternary complexes under conditions relevant to fluorescence imaging. The formation of ternary species elicits comparable or greater optical changes than those attributed to the formation of binary complexes alone. Dissociation of the fluorescent indicators from both ternary and binary species have apparent equilibrium constants in the low millimolar range at pH 7 and 25 °C. These results suggest that these bidentate sensors are incapable of distinguishing between free Mg(2+) and MgATP based on ratio or intensity-based steady-state fluorescence measurements, thus posing challenges in the interpretation of results from fluorescence imaging of magnesium in nucleotide-rich biological samples. PMID:24593871

  12. Neutral muonic helium(3)

    International Nuclear Information System (INIS)

    Neutral muonic helium, He++μ-e-, can be considered in two pieces. The (He++μ-)+-system is a hydrogenic ion halfway in size between an atom and a nucleus. It acts like a singly charged pseudo-nucleus to the electron surrounding it. The whole system appears like one hydrogen inside another. Neutral muonic helium can be formed in the ground state in which the coupling of the magnetic moments gives rise to a hyperfine structure (hfs). 3He++μ-e- has three spin one half particles interact without any restrictions by the Pauli exclusion principle. The level diagram of the ground state is shown. There is a large muonic hfs splitting corresponding to the He++μ- ion to be in one of the two spin states with total spin quantum number G = 0 and G = 1. To measure the atomic hfs superimposed on the G = 1 triplet state is the aim of this experiment. (Auth.)

  13. Ultracold Neutral Plasmas

    CERN Document Server

    Killian, T C; Pohl, T; Rost, J M

    2006-01-01

    Ultracold neutral plasmas, formed by photoionizing laser-cooled atoms near the ionization threshold, have electron temperatures in the 1-1000 kelvin range and ion temperatures from tens of millikelvin to a few kelvin. They represent a new frontier in the study of neutral plasmas, which traditionally deals with much hotter systems, but they also blur the boundaries of plasma, atomic, condensed matter, and low temperature physics. Modelling these plasmas challenges computational techniques and theories of non-equilibrium systems, so the field has attracted great interest from the theoretical and computational physics communities. By varying laser intensities and wavelengths it is possible to accurately set the initial plasma density and energy, and charged-particle-detection and optical diagnostics allow precise measurements for comparison with theoretical predictions. Recent experiments using optical probes demonstrated that ions in the plasma equilibrate in a strongly coupled fluid phase. Strongly coupled pla...

  14. Neutral atom traps.

    Energy Technology Data Exchange (ETDEWEB)

    Pack, Michael Vern

    2008-12-01

    This report describes progress in designing a neutral atom trap capable of trapping sub millikelvin atom in a magnetic trap and shuttling the atoms across the atom chip from a collection area to an optical cavity. The numerical simulation and atom chip design are discussed. Also, discussed are preliminary calculations of quantum noise sources in Kerr nonlinear optics measurements based on electromagnetically induced transparency. These types of measurements may be important for quantum nondemolition measurements at the few photon limit.

  15. Neutral beams for mirrors

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. 高压氧对动物有机磷中毒后神经损害恢复的实验研究%Effect of hyperbaric oxygen on nerve impairment recovery of animals after organophosphorus: an experimental study

    Institute of Scientific and Technical Information of China (English)

    林忠豪; 张鸣春; 肖鹏

    2002-01-01

    Objective To investigate the effect of hyperbarci oxygen(HBO) on recovery of nerves injury in rats suffered from acute organophosphorus poisoning. Method We established organophosphorus poisoning models and observed effect of HBO on recovery of injure nerves. Results Compared with control group, cerebrospinal fluid induced peak potential and incubation period in HBO group were significantly recovered(P<0.05).HBO could accelerated repair of injured nerves. Conclusion HBO could relieve injury of nerves during treatment of organophosphorus poisoning. ``

  18. Organophosphorus pentavalent compounds: history, synthetic methods of preparation and application as insecticides and antitumor agents; Compostos organofosforados pentavalentes: historico, metodos sinteticos de preparacao e aplicacoes como inseticidas e agentes antitumorais

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Viviane Martins Rebello dos; Donnici, Claudio Luis [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil). Dept. de Quimica; DaCosta, Joao Batista Neves; Caixeiro, Janaina Marques Rodrigues [Universidade Federal Rural do Rio de Janeiro, Seropedica, RJ (Brazil). Dept. de Quimica]. E-mail: dacosta@ufrrj.br

    2007-01-15

    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)

  19. Synergic extraction of rare earths with 2-thenoyltrifluoroacetone and phosphoryl-type bidentate ligands such as tetraphenyldiphosphine dioxide or bis(diphenylphosphinyl)methane

    International Nuclear Information System (INIS)

    The synergic extraction of rare earth(III) ions (RE; La, Sm, Tb and Lu) using 2-thenoyltrifluoroacetone (Htta) and phosphoryl-type uncharged bidentate ligands, such as tetraphenyldiphosphine dioxide (tpdpo) or bis(diphenylphosphinyl)methane (bdppm), was investigated in benzene. The synergic enhancement was attributed to the formation of the adduct RE(tta)3Sn (n=1 or 2 for tpdpo and n=1 for bdppm) in benzene, where S denotes the uncharged ligand. The adduct formation constants (βS) and the synergic extraction constants were determined. For each RE(III), the βS,1 value for bdppm is larger than the βS,1 and βS,2 values for tpdpo and the βS values for both ligands decrease with increasing atomic number of RE(III)

  20. Mn(II) and Cu(II) complexes of a bidentate Schiff's base ligand: Spectral, thermal, molecular modelling and mycological studies

    Science.gov (United States)

    Tyagi, Monika; Chandra, Sulekh; Tyagi, Prateek

    2014-01-01

    Complexes of manganese(II) and copper(II) of general composition M(L)2X2 have been synthesized [L = 2-acetyl thiophene thiosemicarbazone and X = Cl- and NO3-]. The elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, UV, NMR and EPR spectral studies of the compounds led to the conclusion that the ligand acts as a bidentate manner. The Schiff's base ligand forms hexacoordinated complexes having octahedral geometry for Mn(II) and tetragonal geometry for Cu(II) complexes. The thermal studies suggested that the complexes are more stable as compared to ligand. In molecular modelling the geometries of Schiff's base and metal complexes were fully optimized with respect to the energy using the 6-31g(d,p) basis set. The mycological studies of the compounds were examined against the plant pathogenic fungi i.e. Rhizoctonia bataticola, Macrophomina phaseolina, Fusarium odum.

  1. Case histories of bald eagles and other raptors killed by organophosphorus insecticides topically applied to livestock

    Science.gov (United States)

    Henny, C.J.; Kolbe, E.J.; Hill, E.F.; Blus, L.J.

    1987-01-01

    Since 1982 when secondary poisoning of a red-tailed hawk (Buteo jamaicensis) was documented following the recommended use of famphur applied topically to cattle, the Patuxent Wildlife Research Center has tested dead birds of prey for poisoning by famphur and other pour-on organophosphorus (OP) insecticides. Brain cholinesterase (ChE) activity was first determined, then if ChE was depressed greater than or equal to 50%, stomach and/or crop contents were evaluated for anti-ChE compounds. This report presents the circumstances surrounding the OP-caused deaths of eight bald eagles (Haliaeetus leucocephalus), two red-tailed hawks, and one great horned owl (Bubo virginianus) between March 1984 and March 1985. OP poisoning of raptors by pour-on insecticides in the United States is widespread, but its magnitude is unknown.

  2. Influence of organophosphorus pesticides on peroxidase and chlorination activity of human myeloperoxidase.

    Science.gov (United States)

    Lazarević-Pašti, Tamara; Momić, Tatjana; Radojević, Miloš M; Vasić, Vesna

    2013-09-01

    Inhibitory effects of five organophosphorus pesticides (diazinon, malathion, chlorpyrifos, azinphos-methyl and phorate) and their oxo-analogs on human myeloperoxidase (MPO) activity were investigated. While inspecting separately peroxidase and chlorination activity, it was observed that investigated OPs affect peroxidase activity, but not chlorination activity. Among investigated pesticides, malathion and malaoxon have showed the highest power to inhibit MPO peroxidase activity with IC50 values of the order of 3×10(-7) and 5×10(-9) M, respectively. It was proposed that inhibition trend is rendered by molecular structure which invokes steric hindrance for OPs interaction with MPO active center responsible for peroxidase activity. In addition, it was concluded that physiological function of MPO is not affected by any of the investigated OPs. PMID:25149236

  3. Study on Carrier Material of Immobilization Acetylcholinesterase For Biosensor in Detectionof Organophosphorus Pesticide Residues

    Science.gov (United States)

    Sun, Xia; Wang, Xiangyou; Jia, Chuandong

    A comparison between several immobilization materials of AChE on surface of glassy carbon electrode(GCE) was presented. The immobilization methods employed crosslinking method with glutaraldehyde as a cross-linking agent and bovine serum albumin(BSA) as a protectant, AChE was immobilized on different membranes including nylon membrane, cellulose nitrate membrane and chitosan membrane respectively. The enzyme membrane was then fixed on the surface of glassy carbon electrode(GCE) with O-ring to prepare an amperometric biosensor for the detection of organophosphorus pesticides. The activity of immobilization AChE was detected by measuring the oxidation current of thiocholine, the results showed that the activity of immobilization AChE were all different with different membrane as carrier material.Compared with nylon membrane and cellulose nitrate membrane, chitosan membrane was obviously good. So chitosan membrane can be selected as immobilized AChE carrier material.

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

    International Nuclear Information System (INIS)

    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 LD50). 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 (T4) and triiodothyronine (T3) also fluctuated

  5. Combined effect of exposure to gamma radiation and /or an organophosphorus insecticide in male rats

    International Nuclear Information System (INIS)

    The effect of a single whole body gamma irradiation at 5 Gy and/or the organophosphorus insecticide (cyanox) at the levels of 29 or 58 mg/kg body weight for three consecutive days has been studied. Activities of ornithine carbamyl transferase (OCT), alanine (ALT) and aspartate (AST) aminotransferases, lactic dehydrogenase (LDH), gamma glutamyl transferase (gamma GT), creatinine phosphokinase (CPK) as well as the ionic contents of Na+ and K+ in serum were measured. Gamma irradiation or cyanox treatment significantly altered serum levels of OCT, ALT, AST, CPK as well as the ionic contents of Na+ and K+. However, the combined treatment of gamma radiation and cyanox did not prove to be synergistic

  6. Anticonvulsant discovery through animal models of status epilepticus induced by organophosphorus nerve agents and pesticides.

    Science.gov (United States)

    McCarren, Hilary S; McDonough, John H

    2016-06-01

    Organophosphorus pesticides (OPs) and nerve agents (NAs) are highly toxic chemicals that pose a significant threat to human health worldwide. These compounds induce status epilepticus (SE) by irreversibly blocking the ability of acetylcholinesterase to break down acetylcholine at neural synapses. Animal models of organophosphate-induced SE are a crucial resource for identifying new anticonvulsant therapies. Here, we describe the development of various animal models of SE induced by NA or OP exposure. Experiments in nonhuman primates, rats, mice, and guinea pigs have helped to identify novel therapeutic targets in the central nervous system, with particular success at modulating GABAergic and glutamatergic receptors. The anticonvulsants identified by NA- and OP-induced SE models are well poised for fast advancement into clinical development, and their potential utility in the broader field of epilepsy should make them all the more attractive for commercial pursuit. PMID:27258770

  7. Pharmacotherapy to protect the neuromuscular junction after acute organophosphorus pesticide poisoning.

    Science.gov (United States)

    Bird, Steven B; Krajacic, Predrag; Sawamoto, Keigo; Bunya, Naofumi; Loro, Emanuele; Khurana, Tejvir S

    2016-06-01

    Organophosphorus (OP) pesticide poisoning is a leading cause of morbidity and mortality in the developing world, affecting an estimated three million people annually. Much of the morbidity is directly related to muscle weakness, which develops 1-4 days after poisoning. This muscle weakness, termed the intermediate syndrome (IMS), leads to respiratory, bulbar, and proximal limb weakness and frequently necessitates the use of mechanical ventilation. While not entirely understood, the IMS is most likely due to persistently elevated acetylcholine (ACh), which activates nicotinic ACh receptors at the neuromuscular junction (NMJ). Thus, the NMJ is potentially a target-rich area for the development of new therapies for acute OP poisoning. In this manuscript, we discuss what is known about the IMS and studies investigating the use of nicotinic ACh receptor antagonists to prevent or mitigate NMJ dysfunction after acute OP poisoning. PMID:27258847

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

    International Nuclear Information System (INIS)

    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)

  9. A Survey of Determination for Organophosphorus Pesticide Residue in Agricultural Products

    Directory of Open Access Journals (Sweden)

    Wen Li

    2013-04-01

    Full Text Available In order to find a fast, high efficient determination method of Organophosphorus Pesticides (OPPs residue because OPPs widely used in crops pest control fields in China are causing fearful risks for environment as well as animals and human health, traditional and advanced determination methods were discussed in the study. Based on the spectrum analysis technology combined colorimetric OPPs residue detection experiments in leafy vegetables showed that the absorbance of color reaction between OPPs residues and suitable colorimetric reagents can be distinguished in ppm level of OPPs residues. The detection limit of chlorpyrifos after color reaction with 0.5% Pbcl2 in acetic acid solution is 0.5 ppm. The conclusion was drawn that the detection technologies were diversified, however, a simple, efficient, rapid and nondestructive detection method is lacking and the spectrum analysis technology combined colorimetric can be a new fast and efficient determination method in the future.

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

    International Nuclear Information System (INIS)

    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

  11. Synthesis, characterization and crystal structures of the bidentate Schiff base N,N'-bis(2-nitrocinnamaldehyde)ethylenediamine and its complex with CuNCS and triphenylphosphane.

    Science.gov (United States)

    Clegg, William; Harrington, Ross W; Barati, Kazem; Habibi, Mohammad Hossein; Montazerozohori, Morteza; Lalegani, Arash

    2015-07-01

    Reaction of copper(I) thiocyanate and triphenylphosphane with the bidentate Schiff base N,N'-bis(trans-2-nitrocinnamaldehyde)ethylenediamine {Nca2en, (1); systematic name (1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]}, C20H18N4O4, in a 1:1:1 molar ratio in acetonitrile resulted in the formation of the complex {(1E,1'E,2E,2'E)-N,N'-(ethane-1,2-diyl)bis[3-(2-nitrophenyl)prop-2-en-1-imine]-κ(2)N,N'}(thiocyanato-κN)(triphenylphosphane-κP)copper(I)], [Cu(NCS)(C20H18N4O4)(C18H15P)] or [Cu(NCS)(Nca2en)(PPh3)], (2). The Schiff base and copper(I) complex have been characterized by elemental analyses, IR, electronic and (1)H NMR spectroscopy, and X-ray crystallography [from synchrotron data for (1)]. The molecule of (1) lies on a crystallographic inversion centre, with a trans conformation for the ethylenediamine unit, and displays significant twists from coplanarity of its nitro group, aromatic ring, conjugated chain and especially ethylenediamine segments. It acts as a bidentate ligand coordinating via the imine N atoms to the Cu(I) atom in complex (2), in which the ethylenediamine unit necessarily adopts a somewhat flattened gauche conformation, resulting in a rather bowed shape overall for the ligand. The NCS(-) ligand is coordinated through its N atom. The geometry around the Cu(I) atom is distorted tetrahedral, with a small N-Cu-N bite angle of 81.56 (12)° and an enlarged opposite angle of 117.29 (9)° for SCN-Cu-P. Comparisons are made with the analogous Schiff base having no nitro substituents and with metal complexes of both ligands. PMID:26146396

  12. Supercritical fluid extraction of thorium from tissue paper matrix employing organophosphorus reagents

    International Nuclear Information System (INIS)

    Feasibility of supercritical CO2 extraction of thorium from tissue paper matrix was studied and various organophosphorus reagents (TBP, TOPO, TPP, TPPO, TBPO) were evaluated as co-solvent. Effects of pressure (100-300 atm), temperature (313-353 K), flow rate (0.5-3 mL min-1), static time (0-40 min) and extraction time (0.5-40 min) on thorium extraction efficiency were investigated. Pressure of 200 atm, temperature of 333 K, CO2 flow rate of 2 mL min-1, 20 min static period followed by 20 min of extraction were found to be optimum. Under optimum conditions employing various organophosphorus reagents as co-solvent, extraction efficiency indicated the trends: (i) Among phosphates, if aliphatic group attached to P was replaced by aromatic group, then extraction efficiency decreased e.g. TBP (53 ± 8%) and TPP (39 ± 5%). (ii) Among the phosphine oxides, higher the aliphatic chain length attached to P, higher was the extraction efficiency e.g. TOPO (68 ± 4%) and TBPO (50 ± 9%). (iii) In case of phosphine oxides, if phenyl group was attached to P i.e. TPPO (59 ± 15%) then extraction efficiency was intermediate to TOPO and TBPO. (iv) Between phosphates and phosphine oxides, for aliphatic hydrocarbons, the extraction efficiencies were comparable e.g. TBP and TBPO. For aromatic ring, extraction efficiency was higher in phosphine oxides e.g. TPP and TPPO. Both TBPO and TPP have shown higher extraction efficiency in combination with TBP. The solvents dissolving oraganophosphorus reagents were found to influence extraction efficiency. The extraction efficiency was found to decrease slightly with increasing aliphatic chain length of the alcohol. The maximum extraction efficiency was obtained with 0.2 M TOPO in methanol where thorium was extractable with 68 ± 4% efficiency. (orig.)

  13. Comparison Between the Efficiency of Advanced Oxidation Process and Coagulation for Removal Organophosphorus and Carbamat Pesticides

    Directory of Open Access Journals (Sweden)

    A.R Rahmani

    2011-10-01

    Full Text Available Background and Objectives: Water pollution by pesticides has adverse effects on the environment and human health, as well .In recent years, advanced oxidation processes, have been gone through to a very high degree for pesticides removal. Poly-Aluminum chloride (PAC used for water treatment, can be effective on pesticides removal. The aim of this research was to study the use of UV/O3 and PAC in the removal of pesticides from drinking water.Materials and Methods: In this descriptive- analytical survey, specific concentrations of pesticides (1,5,10,15,20 ppm;namely Diazinon, Chlorpyrifos, Carbaril were prepared through addition to deionized water. Dichloromethane was used for samples' extraction, samples extracted with Liquid- Liquid & Solid-phase extraction , finally entered bath reactor at pH (6,7,9 .The samples then exposed to UV/O3at contact time of (0.5,1,1.5 and 2 hours . In the PAC pilot , the effects of various concentrations of pesticides, and PAC - ranging (12/24 and 36 ppm were investigated for the efficacy of pesticides removal. All samples analyzed by GC/MS/MS and HPLC. Results: It was found that in UV/O3 reactor, with the rise of pH, decrease in pesticides concentration, and rise of contact time, the efficiency of removal increased too. In the PAC pilot, increase in PAC concentration and decrease in pesticides concentration , both increased the efficiency. Besides, both of the methods showed high efficiencies in the removal of both pesticides,i-e. halogenated Organophosphorus (Chlorpyrifos , non- halogenated Organophosphorus (Diazinon at the degree of over (%80 ; In case of carbamate pesticides (e.g. Carbaril efficiency was over (>%90. One-Way Anova & Two -Way Anova were used to analyze the obtained data.Conclusion: According these results these two methods are suggested for the removal of pesticides from aqueous solutions.

  14. Nonexotic Neutral Gauge Bosons

    OpenAIRE

    Appelquist, Thomas; Dobrescu, Bogdan A.; Hopper, Adam R.

    2002-01-01

    We study theoretical and experimental constraints on electroweak theories including a new color-singlet and electrically-neutral gauge boson. We first note that the electric charges of the observed fermions imply that any such Z' boson may be described by a gauge theory in which the Abelian gauge groups are the usual hypercharge along with another U(1) component in a kinetic-diagonal basis. Assuming that the observed quarks and leptons have generation-independent U(1) charges, and that no new...

  15. Protective Effect of Selenium-Based Medicines on Toxicity of Three Common Organophosphorus Compounds in Human Erythrocytes In Vitro

    OpenAIRE

    Fakhri-Bafghi, Maryam Sadat; Ghasemi-Niri, Seyedeh Farnaz; Mostafalou, Sara; Navaei-Nigjeh, Mona; Baeeri, Maryam; Mohammadirad, Azadeh; Abdollahi, Mohammad

    2016-01-01

    Objective Organophosphorus (OP) compounds are used to control pests, however they can reach the food chain and enter the human body causing serious health problems by means of acetylcholinesterase (AChE) inhibition and oxidative stress (OS). Among the OPs, chlorpyrifos (CHP), malathion (MAL), and diazinon (DIA) are commonly used for commercial extermination purposes, in addition to veterinary practices, domestic, agricul- ture and public health applications. Two new recently registered medici...

  16. Delayed Reduction of Hippocampal Synaptic Transmission and Spines Following Exposure to Repeated Subclinical Doses of Organophosphorus Pesticide in Adult Mice

    OpenAIRE

    Speed, Haley E.; Blaiss, Cory A.; Kim, Ahleum; Haws, Michael E.; Melvin, Neal R.; Jennings, Michael; Eisch, Amelia J.; Powell, Craig M.

    2011-01-01

    Agricultural and household organophosphorus (OP) pesticides inhibit acetylcholinesterase (AchE), resulting in increased acetylcholine (Ach) in the central nervous system. In adults, acute and prolonged exposure to high doses of AchE inhibitors causes severe, clinically apparent symptoms, followed by lasting memory impairments and cognitive dysfunction. The neurotoxicity of repeated environmental exposure to lower, subclinical doses of OP pesticides in adults is not as well studied. However, r...

  17. Genome-Wide Gene Expression Analysis in Response to Organophosphorus Pesticide Chlorpyrifos and Diazinon in C. elegans

    OpenAIRE

    Viñuela, Ana; Snoek, L Basten; Joost A. G. Riksen; Kammenga, Jan E

    2010-01-01

    Organophosphorus pesticides (OPs) were originally designed to affect the nervous system by inhibiting the enzyme acetylcholinesterase, an important regulator of the neurotransmitter acetylcholine. Over the past years evidence is mounting that these compounds affect many other processes. Little is known, however, about gene expression responses against OPs in the nematode Caenorhabditis elegans. This is surprising because C. elegans is extensively used as a model species in toxicity studies. T...

  18. Quantum dot-DNA aptamer conjugates coupled with capillary electrophoresis: A universal strategy for ratiometric detection of organophosphorus pesticides.

    Science.gov (United States)

    Tang, Tingting; Deng, Jingjing; Zhang, Min; Shi, Guoyue; Zhou, Tianshu

    2016-01-01

    Based on the highly sensitivity and stable-fluorescence of water-soluble CdTe/CdS core-shell quantum dots (QDs) with broad-specificity DNA aptamers, a novel ratiometric detection strategy was proposed for the sensitive detection of organophosphorus pesticides by capillary electrophoresis with laser-induced fluorescence (CE-LIF). The as-prepared QDs were first conjugated with the amino-modified oligonucleotide (AMO) by amidation reaction, which is partial complementary to the DNA aptamer of organophosphorus pesticides. Then QD-labeled AMO (QD-AMO) was incubated with the DNA aptamer to form QD-AMO-aptamer duplex. When the target organophosphorus pesticides were added, they could specifically bind the DNA aptamer, leading to the cleavage of QD-AMO-aptamer duplex, accompany with the release of QD-AMO. As a result, the ratio of peak height between QD-AMO and QD-AMO-aptamer duplex changed in the detection process of CE-LIF. This strategy was subsequently applied for the detection of phorate, profenofos, isocarbophos, and omethoate with the detection limits of 0.20, 0.10, 0.17, and 0.23μM, respectively. This is the first report about using QDs as the signal indicators for organophosphorus pesticides detection based on broad-specificity DNA aptamers by CE-LIF, thus contributing to extend the scope of application of QDs in different fields. The proposed method has great potential to be a universal strategy for rapid detection of aptamer-specific small molecule targets by simply changing the types of aptamer sequences. PMID:26695234

  19. Recent approaches to improving selectivity and sensitivity of enzyme-based biosensors for organophosphorus pesticides: A review.

    Science.gov (United States)

    Songa, Everlyne A; Okonkwo, Jonathan O

    2016-08-01

    Pesticide determination has attracted great attention due to the fact that they exhibit high acute toxicity and can cause long-term damage to the environment and human lives even at trace levels. Although classical analytical methods (including gas chromatography, high performance liquid chromatography, capillary electrophoresis and mass spectrometry) have been effectively used for analysis of pesticides in contaminated samples, they present certain limitations such as time-consuming sample preparation, complexity, and the requirement of expensive instrumentation and highly skilled personnel. For these reasons, there is an expanding need for analytical methods able to provide simple, rapid, sensitive, selective, low cost and reliable detection of pesticides at trace levels. Over the past decades, acetylcholinesterase (AChE) biosensors have emerged as simple, rapid and ultra-sensitive tools for toxicity detection of pesticides in the environment and food. These biosensors have the potential to complement or replace the classical analytical methods by simplifying or eliminating sample preparation and making field-testing easier and faster with significant decrease in cost per analysis. With the recent engineering of more sensitive AChE enzymes, the development of more reliable immobilization matrices and the progress in the area of microelectronics, AChE biosensors could become competitive for multi-analyte screening and soon be used for the development of portable instrumentation for rapid toxicity testing of samples. The enzymes organophosphorus hydrolase (OPH) and organophosphorus acid anhydrolase (OPAA) have also shown considerable potential in OP biosensor applications and they have been used for direct detection of OPs. This review presents the recent advances in the fabrication of enzyme biosensors for organophosphorus pesticides (OPs) and their possible applications for toxicity monitoring of organophosphorus pesticide residues in real samples. The focus will

  20. Detection of Organochlorine and Organophosphorus Pesticides Residues in Water Samples of Taragong Thana in Rangpur District in Bangladesh

    Directory of Open Access Journals (Sweden)

    Arafin Gulsan Ara

    2014-02-01

    Full Text Available This study was undertaken to identify Organochlorine and Organophosphorous pesticides residues in water samples of some paddy fields, ponds and tubewells in Rangpur district (Taragong Thana of Bangladesh by using High Performance Liquid Chromatography (HPLC. Among thirty samples, Organophosphorus (Malathion pesticide was found in twelve samples while Organocholorine was absent. The level of the pesticide residues (Malathion were found in the range of 2 to 221 ppm, which were above the maximum acceptable levels of total and individual pesticide contamination.

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

    OpenAIRE

    Ashok Mulchandani; Wilfred Chen; Priti Mulchandani; Michael Arzdorf; Michael J. Schöning

    2003-01-01

    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 refere...

  2. Comparison of Search Engines Non-Neutral and Neutral Behaviors

    OpenAIRE

    COUCHENEY, Pierre; Maillé, Patrick; Tuffin, Bruno

    2012-01-01

    Network neutrality has recently attracted a lot of attention but search neutrality is also becoming a vivid subject of discussion because a non-neutral search may prevent some relevant content from being accessed by users. We propose in this paper to model two situations of a non-neutral search engine behavior, which can rank the link propositions according to the pro t a search can generate for it instead of just relevance: the case when the search engine owns some content, and the case when...

  3. 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.

  4. Antihypertensive neutral lipid

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-06-17

    A method is described for treating a warm-blooded animal comprising administering to the animal a neutral glycerolipid with a 12 to 20 carbon alkyl group at the sn-1 position, a short carbon chain acyl group at the sn-2 position and a hydroxyl group at the sn-3 position in an amount sufficient to lower the arterial blood pressure of the animal. A method is also described for treating a warm-blooded animal comprising administering a composition consisting essentially of a 1-alkyl-2-acetyl (or propionyl)-sn glycerol in combination with a 1-alkyl-2-acetyl-sn-glycero-3-phosphocholine, wherein the 1-alkyl groups contain 12 to 20 carbon atoms, dissolved in an inert pharmaceutically acceptable solvent in amounts sufficient to lower the arterial blood pressure of the animal.

  5. Accessibility control on copper(II) complexes in mesostructured porous silica obtained by direct synthesis using bidentate organosilane ligands.

    Science.gov (United States)

    Zhou, Wen-Juan; Albela, Belén; Perriat, Pascal; He, Ming-Yuan; Bonneviot, Laurent

    2010-08-17

    The accessibility of metal(II) complexes in 2D hexagonal mesostructured porous silicas obtained by direct synthesis is controlled using an appropriate organosilane ligand. This is exemplified here using copper(II) as a transition metal probe and a neutral or negatively charged ligand: N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, L(A), and, N-salicylaldimine-propylamine-trimethoxysilane, L(B)(-), respectively. L(A) leads to inaccessible complexes located into the pore wall and called "embedded" sites here where silanolate groups from the siliceous network block the access to Cu(II) ions. By contrast, L(B)(-) generates accessible complexes, named "showing-on" sites here. The copper-containing silicas were synthesized with various metal molar ratios (M/SiO(2) = 0.5-3%) in basic media, with cetyltrimethylammonium p-toluenesulfonate (CTATos) as template and with sodium silicate solution as silicon source. A soft template extraction procedure has been developed to preserve the complex integrity of the showing-on copper sites during the treatment. The embedded copper(II) and nickel(II) sites were compared. Materials containing embedded, showing-on, and grafted sites were also compared with regard to pore size, surface polarity, and metal leaching. The material containing showing-on sites was found to be catalytically active for the hydroxylation of phenol into catechol and hydroquinone. Both textural and structural properties of the material and the copper sites were investigated using XRD, TEM, N(2) sorption isotherms, TGA, FT-IR, UV-visible, and EPR spectroscopies. PMID:20695596

  6. CO2-neutral fuels

    Science.gov (United States)

    Goede, A. P. H.

    2015-08-01

    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 cycle is

  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. Synthesis, spectroscopic characterization, photochemical and photophysical properties and biological activities of ruthenium complexes with mono- and bi-dentate histamine ligand.

    Science.gov (United States)

    Cardoso, Carolina R; de Aguiar, Inara; Camilo, Mariana R; Lima, Márcia V S; Ito, Amando S; Baptista, Maurício S; Pavani, Christiane; Venâncio, Tiago; Carlos, Rose M

    2012-06-14

    The monodentate cis-[Ru(phen)(2)(hist)(2)](2+)1R and the bidentate cis-[Ru(phen)(2)(hist)](2+)2A complexes were prepared and characterized using spectroscopic ((1)H, ((1)H-(1)H)COSY and ((1)H-(13)C)HSQC NMR, UV-vis, luminescence) techniques. The complexes presented absorption and emission in the visible region, as well as a tri-exponential emission decay. The complexes are soluble in aqueous and non-aqueous solution with solubility in a buffer solution of pH 7.4 of 1.14 × 10(-3) mol L(-1) for (1R + 2A) and 6.43 × 10(-4) mol L(-1) for 2A and lipophilicity measured in an aqueous-octanol solution of -1.14 and -0.96, respectively. Photolysis in the visible region in CH(3)CN converted the starting complexes into cis-[Ru(phen)(2)(CH(3)CN)(2)](2+). Histamine photorelease was also observed in pure water and in the presence of BSA (1.0 × 10(-6) mol L(-1)). The bidentate coordination of the histamine to the ruthenium center in relation to the monodentate coordination increased the photosubstitution quantum yield by a factor of 3. Pharmacological studies showed that the complexes present a moderate inhibition of AChE with an IC(50) of 21 μmol L(-1) (referred to risvagtini, IC(50) 181 μmol L(-1) and galantamine IC(50) 0.006 μmol L(-1)) with no appreciable cytotoxicity toward to the HeLa cells (50% cell viability at 925 μmol L(-1)). Cell uptake of the complexes into HeLa cells was detected by fluorescence confocal microscopy. Overall, the observation of a luminescent complex that penetrates the cell wall and has low cytotoxicity, but is reactive photochemically, releasing histamine when irradiated with visible light, are interesting features for application of these complexes as phototherapeutic agents. PMID:22539182

  9. The merits of neutral theory

    NARCIS (Netherlands)

    Alonso, David; Etienne, Rampal S.; McKane, Alan 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 al

  10. Self-neutralizing well acidizing

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, E.A.; Scheuerman, R.F.

    1974-07-30

    A process for acidizing a subterranean region by contacting it with an acidic solution is improved by dissolving in the solution a pH-increasing reactant that subsequently adjusts the pH of the solution to a selected relatively neutral value. Urea is an example of the acid neutralizer. (10 claims)

  11. 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

  12. Enhanced photocatalytic H2 production on CdS nanorods with simple molecular bidentate cobalt complexes as cocatalysts under visible light.

    Science.gov (United States)

    Irfan, Rana Muhammad; Jiang, Daochuan; Sun, Zijun; Lu, Dapeng; Du, Pingwu

    2016-08-01

    Photocatalytic hydrogen production via water splitting has attracted much attention for future clean energy application. Herein we report a noble-metal-free photocatalytic hydrogen production system containing a simple bidentate cobalt Schiff base complex as the molecular cocatalyst, CdS nanorods as the photosensitizer, and ascorbic acid as the electron donor. The system shows highly enhanced photocatalytic activity compared to pure CdS NRs under visible light (λ > 420 nm). Under optimal conditions, the turnover numbers (TONs) for hydrogen production reached ∼15 200 after 12 hours of irradiation, and an apparent quantum yield of ∼27% was achieved at 420 nm monochromatic light. Steady-state photoluminescence (PL) spectra indicated efficient charge transfer between the excited CdS NRs and the cobalt cocatalyst for improved hydrogen production. Spectroscopic studies of the photocatalytic reaction revealed the reduction of the Co(ii) complex to Co(i) species, which are probably active intermediates for hydrogen evolution. On the basis of the spectroscopic studies, we propose a reaction mechanism for hydrogen production in the present photocatalytic system. PMID:27476445

  13. Synthesis of a series of new platinum organometallic complexes derived from bidentate Schiff-base ligands and their catalytic activity in the hydrosilylation and dehydrosilylation of styrene.

    Science.gov (United States)

    Lachachi, M Belhadj; Benabdallah, Tayeb; Aguiar, Pedro M; Youcef, M Hadj; Whitwood, Adrian C; Lynam, Jason M

    2015-07-14

    The synthesis and properties of a novel class of platinum complexes containing Schiff bases as O,N-bidentate ligands is described as are the solution and solid state properties of the uncomplexed ligands. The platinum complexes were prepared from [PtBr2(COD)] (COD = 1,5-cyclooctadiene) and N-(2-hydroxy-1-naphthalidene)aniline derivatives in the presence of base (NaOBu(t)). Instead of a substitution reaction to afford cationic species, the addition of the Schiff base ligands results in both the formal loss of two equivalents of bromide and addition of hydroxide to the COD ligand of the complexes. It is proposed that this reaction proceeds through a cationic platinum complex [Pt(N-O)(COD)]Br which then undergoes addition of water and loss of HBr. An example of a dinuclear platinum complex in which two cyclo-octene ligands are bridged by an ether linkage is also reported. The platinum complexes were evaluated as catalysts for the hydrogenative and dehydrogenative silylation of styrene, the resulting behaviour is substituent, time and temperature dependent. PMID:26061657

  14. Thiocyanato complexes of Co(II), Ni(II), Zn(II), Cd(II), Cr(III) and U(IV) containing unidentate and bidentate auxiliary ligands

    International Nuclear Information System (INIS)

    Several thiocyananato complexes of Co(II), Ni(II), Zn(II), Cd(II), Cr(III) and U(VI) containing some unidentate and bidentate auxiliary ligands have been synthesised and characterized by elemental analyses, magnetic and conductivity measurement, IR and electronic spectral studies. The complexes have the composition [Co(SCN)/sub 2/4L], [Ni(SCN)/sub 2/2L.H/sub 2/O], [Zn(SCN)/sub 2/.2L], [Cd(SCN)/sub 2/.L'] [Cd(SCN)/sub 2/.2L] H/sub 2/O, [UO/sub 2/(NCS)/sub 2/.3L] and UO/sub 2/(NCS)2L'] H/sub 2/O where L=NH/sub 2/-NH/sub 2/; L'=NH/sub 2/CH/sub 2/CH/sub 2/NH/sub 2/ and C/sub 6/H/sub 4/-(NH/sub 2)/sub 2/. The molar conductance data indicate that all the complexes behave as 2:1 electrolyte in DMSO magnetic and spectral data are in support of octahedral geometry for cobalt, nickel, chromium and uranium complexes whereas the zinc and cadmium complexes are probably tetrahedral in nature. (author)

  15. New bidentate non-centrosymmetric borate-malate: Synthesis, structure and characterization of RbB(DL-C4H4O5)2.H2O

    International Nuclear Information System (INIS)

    Highlights: → We obtained a new nonlinear optical compound, RbB(DL-C4H4O5)2.H2O, with a bidentate structure. → The crystal structure, thermal behaviour and second order nonlinear optical properties were presented. → RbB(DL-C4H4O5)2.H2O exhibits a strong SHG signal about 2 times that of produced by KH2PO4. - Abstract: A single crystal of RbB(DL-C4H4O5)2.H2O (RBC) has been grown with a size of up to 11 mm x 8 mm x 3 mm through slow evaporation of its precursors' solution at room temperature. The structure of RBC was determined by single-crystal X-ray diffraction. Crystal data: RBC, Mr = 378.44; orthorhombic, space group Pna21 (No. 33); cell parameters, a = 11.4938(9) A, b = 5.4021(5) A, c = 21.1696(12) A and Z = 4. It exhibits a two-dimensional layer structure down the b axis, consisting of RbO7 polyhedra, BO4 tetrahedra, malate groups, and H2O molecules. The material is second harmonic generation (SHG) active; its SHG intensity is about 2 times that of KH2PO4 (KDP).

  16. The Sarin-like Organophosphorus Agent bis (isopropyl methyl)phosphonate Induces Apoptotic Cell Death and COX-2 Expression in SK-N-SH Cells.

    Science.gov (United States)

    Arima, Yosuke; Yoshimoto, Kanji; Namera, Akira; Makita, Ryosuke; Murata, Kazuhiro; Nagao, Masataka

    2016-03-01

    Organophosphorus compounds, such as sarin, are highly toxic nerve agents that inhibit acetylcholinesterase (AChE), but not cholinesterase, via multiple mechanisms. Recent studies have shown that organophosphorus compounds increase cyclooxygenase-2 (COX-2) expression and induce neurotoxicity. In this study, we examined the toxicity of the sarin-like organophosphorus agent bis(isopropyl methyl)phosphonate (BIMP) and the effects of BIMP on COX-2 expression in SK-N-SH human neuroblastoma cells. Exposure to BIMP changed cell morphology and induced caspase-dependent apoptotic cell death accompanied by cleavage of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). It also increased COX-2 expression, while pretreatment with a COX inhibitor, ibuprofen, decreased BIMP-dependent cell death and COX-2 expression in SK-N-SH cells. Thus, our findings suggest that BIMP induces apoptotic cell death and upregulates COX-2 expression. PMID:27348899

  17. Separation of chlorinated hydrocarbons and organophosphorus,pyrethroid pesticides by silicagel fractionation chromatography and their simultaneous determination by GC-MS

    Institute of Scientific and Technical Information of China (English)

    WANG Li-gang; JIANG Xin; WANG Fang; BIAN Yong-rong; Stephan Forster; Dieter Martens

    2004-01-01

    A silicagel fractionation procedure for environmental sample extracts, which separates chlorinatedhydrocarbons(CHCs) and organophosphorus, pyrethroid pesticides into two groups for subsequent instrumentalanalysis, was developed in this study. This method was achieved by optimizing the fraction cut-off volume of elutionand different solvents. Using fully activated silica gel and cut-off CHCs collection after 10 mi 10% dichloromethane(DCM) in n-hexane passing through the column resulted in satisfactory separation of CHCs and organophosphorus,pyrethroid pesticides. This procedure had a higher reliability for CHCs than for organophosphorus, pyrethroidpesticides, because there is a relatively reliable recovery for CHCs. This approach is less expensive due to reducingsample pre-treatment time and solvent consumption.

  18. Organophosphorus pesticide residues in raw milk and infant formulas from Spanish northwest.

    Science.gov (United States)

    Melgar, M J; Santaeufemia, M; Garcia, M A

    2010-10-01

    Residue levels of seven organophosphorus pesticides (OPPs), widely used as dairy cattle ectoparasiticides or in crops used for animal feed, were determined in raw milk and infant formulas. A total of 312 samples were collected (70 from infant formulas and 242 from raw milk) biweekly during a 24-month period. Pesticides were extracted by means of a solid phase system into acetone. An extract aliquot of acetone was injected into a gas chromatograph (GC) with a nitrogen-phosphorus detector. Recoveries of pesticides spiked in milk samples were 62.2 - 97.2 %. The frequency of total samples containing detectable levels of OPP residues was 6.73 % in total milk and 8.67 % in raw milk. The highest percentage incidence measured was for dichlorvos (5.78 %), followed by coumaphos (2.06 %), and parathion methyl (0.83 %). The range of positive results was calculated to be between 0.005 and 0.220 mg kg(- 1). No residue was detected in the final product (infant formulas), so any risk to consumer health, especially to children's health, would be limited. PMID:20803361

  19. Prediction of gas chromatographic retention indices of organophosphorus compounds by holographic QSRR

    Institute of Scientific and Technical Information of China (English)

    WANG HaiYan; ZHANG AiQian; SUN Cheng; WANG LianSheng

    2009-01-01

    A new molecular structure representation, molecular hologram, is employed to investigate the quanti-tative relationship between gas chromatographic retention indices and molecular structures for 41 methyl-esterified organophosphorus compounds (OPs). The quantitative structure-retention relation-ship (QSRR) model has been constructed for GC-RI of the selected OPs through partial least squares regression, which shows high statistical quality and predictive value with non-cross validation corre-lation coefficient r2 of 0.994, and cross validation correlation coefficient q2LOO values of 0.984. In order to verify the robustness and prediction capacity of the model, 30 OPs were randomly selected from the database as the training set, while the rest were used as the testing set. The result of PLS re-gressive analysis of the training set yields r2 of 0.995 and q2LOO of 0.982, suggesting the excellent ability to predict the GC-RIs of OPs in the testing set. Furthermore, the retention behavior of the compounds in GC stationary phase is discussed, and the effects of different groups on the OP side-chain in the in-teraction between OPs and the stationary phase are explored using HQSAR color code, which provides useful guideline for the retention rules of OPs and related compounds.

  20. Simultaneous determination of three organophosphorus pesticides in different food commodities by gas chromatography with mass spectrometry.

    Science.gov (United States)

    Vijaya Bhaskar Reddy, Ambavaram; Yusop, Zulkifli; Jaafar, Jafariah; Bin Aris, Azmi; Abdul Majid, Zaiton; Umar, Khalid; Talib, Juhaizah

    2016-06-01

    A sensitive and selective gas chromatography with mass spectrometry method was developed for the simultaneous determination of three organophosphorus pesticides, namely, chlorpyrifos, malathion, and diazinon in three different food commodities (milk, apples, and drinking water) employing solid-phase extraction for sample pretreatment. Pesticide extraction from different sample matrices was carried out on Chromabond C18 cartridges using 3.0 mL of methanol and 3.0 mL of a mixture of dichloromethane/acetonitrile (1:1 v/v) as the eluting solvent. Analysis was carried out by gas chromatography coupled with mass spectrometry using selected-ion monitoring mode. Good linear relationships were obtained in the range of 0.1-50 μg/L for chlorpyrifos, and 0.05-50 μg/L for both malathion and diazinon pesticides. Good repeatability and recoveries were obtained in the range of 78.54-86.73% for three pesticides under the optimized experimental conditions. The limit of detection ranged from 0.02 to 0.03 μg/L, and the limit of quantification ranged from 0.05 to 0.1 μg/L for all three pesticides. Finally, the developed method was successfully applied for the determination of three targeted pesticides in milk, apples, and drinking water samples each in triplicate. No pesticide was found in apple and milk samples, but chlorpyrifos was found in one drinking water sample below the quantification level. PMID:27095506

  1. Nanomaterials - Acetylcholinesterase Enzyme Matrices for Organophosphorus Pesticides Electrochemical Sensors: A Review

    Directory of Open Access Journals (Sweden)

    Shen-Ming Chen

    2009-05-01

    Full Text Available Acetylcholinesterase (AChE is an important cholinesterase enzyme present in the synaptic clefts of living organisms. It maintains the levels of the neurotransmitter acetylcholine by catalyzing the hydrolysis reaction of acetylcholine to thiocholine. This catalytic activity of AChE is drastically inhibited by trace amounts of organophosphorus (OP pesticides present in the environment. As a result, effective monitoring of OP pesticides in the environment is very desirable and has been done successfully in recent years with the use of nanomaterial-based AChE sensors. In such sensors, the enzyme AChE has been immobilized onto nanomaterials like multiwalled carbon nanotubes, gold nanoparticles, zirconia nanoparticles, cadmium sulphide nano particles or quantum dots. These nanomaterial matrices promote significant enhancements of OP pesticide determinations, with the thiocholine oxidation occurring at much lower oxidation potentials. Moreover, nanomaterial-based AChE sensors with rapid response, increased operational and long storage stability are extremely well suited for OP pesticide determination over a wide concentration range. In this review, the unique advantages of using nanomaterials as AChE immobilization matrices are discussed. Further, detection limits, sensitivities and correlation coefficients obtained using various electroanalytical techniques have also been compared with chromatographic techniques.

  2. Miniaturized counter current liquid–liquid extraction for organophosphorus pesticides determination

    Directory of Open Access Journals (Sweden)

    Jalal Hassan

    2016-01-01

    Full Text Available In the present work, a simple, rapid, sensitive and economical sample pre-treatment technique; miniaturized counter current liquid–liquid extraction was developed for the determination of organophosphorus pesticide (OPP residue in water samples and compared with conventional dispersive liquid–liquid microextraction. Gas chromatography–flame ionization detector (GC/FID was used for OPP quantification. Two OPPs (diazinon and malathion were selected as model compounds and the proposed methods were carried out for their preconcentration from water samples. The presented method was based on dispersive liquid–liquid extraction with methanol containing butyl acetate as a solvent with density lower than water. After phase separation, butyl acetate was injected into the GC/FID instrument. The linearity was obtained in the concentration range of 0.4–1000.0 μg L−1 and correlation coefficients were in the range of 0.999–0.997 for diazinon and malathion, respectively. The limits of detection (LODs, was based on signal-to-noise ratio (S/N of 0.1 μg L−1 for two pesticides.

  3. Evaluation of two commercial capillary columns for the enantioselective gas chromatographic separation of organophosphorus pesticides.

    Science.gov (United States)

    Fidalgo-Used, Natalia; Blanco-González, Elisa; Sanz-Medel, Alfredo

    2006-12-15

    The separation of the enantiomers of 13 organophosphorus pesticides (OPPs) has been investigated by gas chromatography (GC) with flame ionisation detection (FID) using two different commercially available chiral columns, Chirasil-Val (l-valine-tert-butylamide) and CP-Chirasil-Dex CB (heptakis (2,3,6-tri-O-metil)-beta-cyclodextrin). Using the Chirasil-Val column no chiral resolution was obtained for the OPPs investigated under any tested experimental condition. The use of the CP-Chirasil-Dex CB stationary phase enabled good individual enantiomeric separation of two OPPs, ruelene and trichlorfon and partial separation of naled, chloretoxyphos, isophenphos and metamidophos. Also, the obtained chromatographic results showed that Chirasil-Dex could resolve enantiomers through the combination of different mechanism (e.g. formation of inclusion complexes and/or interactions outside the cyclodextrin cavity). Under optimised conditions, precision, linearity range and detection limits were evaluated for the enantiomers of ruelene and trichlorfon using CP-Chirasil-Dex CB column and electron capture detection (ECD). By using the GC-ECD method the enantiomers of these OPPs could be satisfactorily detected at very low concentration levels. The detection limits observed were 1.5ngmL(-1) and 11.5ngmL(-1) for the enantiomers of trichlorfon and ruelene, respectively. PMID:18970881

  4. 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. PMID:26143468

  5. Magnetic titanium oxide nanoparticles for hemimicelle extraction and HPLC determination of organophosphorus pesticides in environmental water

    International Nuclear Information System (INIS)

    We report on a method for the extraction of organophosphorus pesticides (OPPs) from water samples using mixed hemimicelles and magnetic titanium dioxide nanoparticles (Fe3O4 . TiO2) modified by cetyltrimethylammonium. Fe3O4 . TiO2 nanoparticles were synthesized by a hydrothermal process and then characterized by scanning electron microscopy and Fourier transform IR spectrometry. The effects of the quantity of surfactant, extraction time, desorption solvent, pH value, extraction volume and reuse of the sorbent were optimized with respect to the extraction of OPPs including chlorpyrifos, dimethoate, and trichlorfon. The extraction method was applied to analyze OPPs in environmental water using HPLC along with UV detection. The method has a wide linear range (100–15,000 ng L−1), good linearity (r > 0.999), and low detection limits (26–30 ng L−1). The enrichment factor is ∼1,000. The recoveries (at spiked levels of 100, 1,000 and 10,000 ng L−1) are in the range of 88.5–96.7 %, and the relative standard deviations range from 2.4 % to 8.7 %. (author)

  6. Hypothesis for synergistic toxicity of organophosphorus poisoning-induced cholinergic crisis and anaphylactoid reactions

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, F.M.; Shih, T.M.; Lenz, D.E.; Madsen, J.M.; Broomfield, C.A.

    1996-08-01

    The neurotoxicity of organophosphorus (OP) compounds Involves the Inhibition of acetylchollnesterase (AChE), causing accumulation of acetyicholine (ACh) at synapses. However, cholinergic crisis may not be the sole mechanism of OP toxicity. Adverse drug reactions caused by synergistic toxicity between drugs with distinct pharmacological mechanisms are a common problem. Likewise, the multiple pharmacological activities of a single molecule might also contribute to either toxicity or efficacy. For example, certain OP compounds (e.g. soman) exhibit anti-AChE activity and also act as secretagogues by inducing mast cell degranulation with associated autacoid release and anaphylactoid reactions. Anaphylactoid shock can produce a lethal syndrome with symptoms of respiratory failure and circulatory collapse similar to the physiological sequelae observed for OP poisoning. Moreover, the major classes of drugs used as antidotes for OP intoxication can affect anaphylaxis. Acetylcholine can act as an agonist of autacoid release, and autacoids such as histamine can augment soman-Induced bronchial spasm. In concert with the demonstrably critical role of cholinergic crisis In OP toxicity, the precepts of neuroimmunology indicate that secondary adverse reactions encompassing anaphylactold reactions may complicate OP toxicity.

  7. Evaluation of organophosphorus and synthetic pyrethroid insecticides against six vector mosquitoe species

    Directory of Open Access Journals (Sweden)

    Domingo Montada Dorta

    1993-12-01

    Full Text Available Three organophosphorus compounds- malathion, folithion and temephos- and two synthetic pyrethroids- alphamethrin and deltamethrin- were used for monitoring the susceptibility status of larvae and adults of six vector mosquitoe species: Culex quinquefasciatus (Filariasis and Aedes albopictus (Dengue (both laboratory and field strains; laboratory strains of Aedes aegypti (Dengue, Anopheles slephensi and Anopheles culicifacies (Malaria, and Culex tritaeniorhynchus (Japanese encephalitis in India. From the LC50 values obtained for these insecticides, it was found that all mosquito species including the field strains of Cx. quinquefasciatus and Ae. albopictus were highly susceptible Except for Cx. quinquefasciatus (field strain against malathion, 100% mortality was observed at the discriminating dosages recommended by World Health Organization. The residual effect of alphamethrin, deltamethrin, malathion and folithion at 25 mg (ai/m² on different surfaces against six species of vector mosquitoes showed that alphamethrin was the most effective on all four treated surfaces (mud, plywood, cement and thatch. Nevertheless, residual efficacy lasted longer on thatch than on the other surfaces. Therefore, synthetic pyrethroids such as alphamethrin can be effectively employed in integrated vector control operations.

  8. Evaluation of organophosphorus and synthetic pyrethroid insecticides against six vector mosquitoe species

    Directory of Open Access Journals (Sweden)

    Montada Dorta Domingo

    1993-01-01

    Full Text Available Three organophosphorus compounds- malathion, folithion and temephos- and two synthetic pyrethroids- alphamethrin and deltamethrin- were used for monitoring the susceptibility status of larvae and adults of six vector mosquitoe species: Culex quinquefasciatus (Filariasis and Aedes albopictus (Dengue (both laboratory and field strains; laboratory strains of Aedes aegypti (Dengue, Anopheles slephensi and Anopheles culicifacies (Malaria, and Culex tritaeniorhynchus (Japanese encephalitis in India. From the LC50 values obtained for these insecticides, it was found that all mosquito species including the field strains of Cx. quinquefasciatus and Ae. albopictus were highly susceptible Except for Cx. quinquefasciatus (field strain against malathion, 100% mortality was observed at the discriminating dosages recommended by World Health Organization. The residual effect of alphamethrin, deltamethrin, malathion and folithion at 25 mg (ai/m² on different surfaces against six species of vector mosquitoes showed that alphamethrin was the most effective on all four treated surfaces (mud, plywood, cement and thatch. Nevertheless, residual efficacy lasted longer on thatch than on the other surfaces. Therefore, synthetic pyrethroids such as alphamethrin can be effectively employed in integrated vector control operations.

  9. Determination of the Organophosphorus Pesticide Diclorvos by Enzymatic Flow- Injection Analysis with Conductimetric Detection

    Directory of Open Access Journals (Sweden)

    Khan S.

    2013-04-01

    Full Text Available Brazil is one of the world largest consumers of pesticides. When used properly pesticides help increase production. But when misused they can be extremely detrimental to the environment and to the population, which has led civil society to demand tighter control from environmental agencies and increased the demand for analytical data. In this work, we developed a scanning method for the determination of organophosphorus pesticides using a FIA procedure associated with an enzymatic biosensor based on acetyl cholinesterase. Although immunosensor systems have been proposed as powerful pesticide monitoring tools. The method is based on the generation of acetic acid by the reaction of acetylcholine with the enzyme cholinesterase. Which was chemically immobilized on “CPG” the acetic acid formed permeate through a poly- (tetrauoroethylene (PTFE membrane into a de-ionized water stream. The developed method is extremely simple, sensitive and low cost and selective for inhibitors of this enzyme. For the pesticide paroxon the detection limit was about 10–18 mol L–1, the correlation coefficient was 0.9966 and the standard deviation of 0.0403 (n = 6.

  10. 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

    2015-06-01

    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 (R2 = 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.

  11. 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. PMID:27349770

  12. A novel nanoparticle-based disposable electrochemical immunosensor for diagnosis of exposure to toxic organophosphorus agents

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Donglai; Wang, Jun; Wang, Limin; Du, Dan; Timchalk, Charles; Barry, Richard C.; Lin, Yuehe

    2011-11-15

    We present a novel disposable electrochemical immunosensor for highly selective and sensitive detection of organophosphorylated butyrylcholinesterase (OP-BChE), a specific biomarker for exposure to toxic organophosphorus agents. In our new approach, the zirconia nanoparticles (ZrO-2) were employed to selectively capture the OP moiety of OP-BChE adducts, and followed by quantum dot (QD)-tagged anti-BChE antibodies for amplified quantification. The captured CdSe-QD tags can be sensitively detected by stripping voltammetry using in situ bismuth-plating method. The OP agent, diisopropylfluorophosphate (DFP), was selected to prepare OP-BChE adducts in various matrices. The formation of OP-BChE adducts in plasma sample was confirmed using mass spectroscopy. The developed electrochemical immunosensor demonstrates a highly linear voltammetric response over the range of 0.1 to 30 nM OP-BChE. Moreover, the immunosensor has been successfully applied for the detection of OP-BChE adducts in the plasma samples. This novel nanoparticle-based electrochemical immunosensor thus provides an alternative way for designing simple, fast, sensitive, and cost-effective sensing platform for on-site screening/evaluating exposure to a variety of OP agents.

  13. Biosensor based on Prussian blue nanocubes/reduced graphene oxide nanocomposite for detection of organophosphorus pesticides

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Lin; Zhang, Aidong; Du, Dan; Lin, Yuehe

    2012-07-13

    We demonstrate a facile procedure to efficiently prepare Prussian blue nanocubes/reduced graphene oxide (PBNCs/rGO) nanocomposite by directly mixing Fe3+ and [Fe(CN)6]3 in the presence of GO in polyethyleneimine aqueous solution, resulting in a novel acetylcholinesterase (AChE) biosensor for detection of organophosphorus pesticides (OPs). The obtained nanocomposite was characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) microanalysis. It was clearly observed that the nanosheet has been decorated with cubic PB nanoparticles and nearly all the nanoparticles are distributed uniformly only on the surface of the reduced GO. No isolated PB nanoparticles were observed, indicating the strong interaction between PB nanocubes and the reduced GO and the formation of PBNCs/rGO nanocomposite. The obtained PBNCs/rGO based AChE biosensor make the peak potential shift negatively to 220 mV. The AChE biosensor shows rapid response and high sensitivity for detection of monocrotophos. These results suggest that the PBNCs/rGO hybrids nanocomposite exhibited high electrocatalytic activity towards the oxidation of thiocholine, which lead to the sensitive detection of OP pesticides.

  14. Study on the toxic effect of the mixture of organophosphorus pesticide on perinatal rats

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To observe the toxic effect of the mixture of organophosphorus pesticide (MOP) on maternal rats and on the growth and development of their offspring. Methods Totally 40 Sprague-Dawley pregnant rats were randomly divided into three MOP dose groups and one control to which their offspring would be assigned. The experimental dosage of MOP and distilled water were administered orally starting on gestation day 15 and continued for 35 days. The physical development indices and the learning ability of F1 rats were measured during lactation. The pathological changes of uterus and liver of F0 rats were observed after weaning, while the weight ratio of uterus and some viscera to body of the F1 were examined. Results There were obvious changes of uterus and liver in the high-dose group of F0. The body-weight accretion of the F1 in high-dose group was obviously lower than that in control group (P<0.05). Some of the MOP F1 rats development indices delayed significantly (P<0.05), the learning ability decreased obviously, and the time of setting up memory prolonged (P<0.05). The ratio of the uterus weight to body-weight in the F1 MOP groups was significantly higher than that in control group (P<0.05). Conclusion The experiment doses of MOP are proved to have significant reproductive toxicity on perinatal rats.

  15. Postfledging survival of European starlings exposed as nestlings to an organophosphorus insecticide

    Science.gov (United States)

    Stromborg, K.L.; Grue, C.E.; Nichols, J.D.; Hepp, G.R.; Hines, J.E.; Bourne, H.C.

    1988-01-01

    To test the hypothesis that exposure to organophosphorus (OP) insecticides reduces postfledging survival of altricial birds, 16-d-old European Starlings (Sturnus vulgaris) were weighed and orally dosed with corn oil containing 6.0 mg of dicrotophos per kilogram of body mass or an equivalent exposure of pure corn oil (controls). Two days later, each survivor was weighed again and patagially tagged for identification after fledging. Resightings of marked fledglings were made during weekly 2-d intensive observations yielding four estimates of postfledging survival. Before fledging, only OP-dosed birds died (18.5%), and OP-dosed survivors lost more mass (5.2%, P = .001) than controls (1.4%) but their masses on day 18 were only slightly lower (2% of control mean, P = .10). Brain cholinesterase activity, a sensitive indicator of OP exposure in birds, was depressed and average of 93% in OP-dosed nestlings that died compared to controls, and an average of 46% in OP-dosed nestlings alive on day 18. Age at fledging, postfledging survival, flocking behavior, and habitat use, however, did not differ between OP-dosed and control birds. The effects of the OP on the nestlings appeared to be rapid, to be reversible in survivors, and did not extend into the postfledging period. In addition, we found no relationship between body mass at fledging and postfledging survival.

  16. Gestational Hypertension and Organophosphorus Pesticide Exposure: A Cross-Sectional Study

    Directory of Open Access Journals (Sweden)

    Caterina Ledda

    2015-01-01

    Full Text Available Hypertension is the most common medical problem encountered during pregnancy, complicating 2-3% of pregnancies. High blood pressure (BP with diastolic BP ≥ 90 mm Hg and/or systolic BP ≥ 140 mm Hg arising after week 22 of pregnancy and resolving after delivery is defined as gestational hypertension (GHY. The aim of this cross-sectional study was to investigate whether occupational and/or environmental exposure to organophosphorus (OP pesticide affects GHY. Women at approximately 22 weeks of gestation were recruited. OP pesticide exposure in the first trimester of pregnancy was classified into four categories: no exposure, indirect exposure, domestic exposure, and occupational exposure. Application of the exclusion criteria left 2203 participants (mean age 30.4 ± 11.6 years. Data analysis showed that in women with indirect OP pesticide exposure the incidence of GHY was slightly higher than that in the world population, whereas domestic exposure involved a 7% increase and occupational exposure a 12% increase. Analysis of the pesticides used by participants highlighted a possible role for malathion and diazinon (adjusted OR 1.09 and 1.14, resp.. Further investigation of exposed workers and the general population is clearly warranted given the broad diffusion of OP pesticides and their possible public health impact, maybe by including a wider range of health outcomes.

  17. 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.

  18. 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; Cristina Silva, Maria; 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. PMID:26898655

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

    International Nuclear Information System (INIS)

    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

  20. 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.

  1. Repeated exposure to sublethal doses of the organophosphorus compound VX activates BDNF expression in mouse brain.

    Science.gov (United States)

    Pizarro, Jose M; Chang, Wenling E; Bah, Mariama J; Wright, Linnzi K M; Saviolakis, George A; Alagappan, Arun; Robison, Christopher L; Shah, Jinesh D; Meyerhoff, James L; Cerasoli, Douglas M; Midboe, Eric G; Lumley, Lucille A

    2012-04-01

    The highly toxic organophosphorus compound VX [O-ethyl S-[2-(diisopropylamino)ethyl]methylphosphonate] is an irreversible inhibitor of the enzyme acetylcholinesterase (AChE). Prolonged inhibition of AChE increases endogenous levels of acetylcholine and is toxic at nerve synapses and neuromuscular junctions. We hypothesized that repeated exposure to sublethal doses of VX would affect genes associated with cell survival, neuronal plasticity, and neuronal remodeling, including brain-derived neurotrophic factor (BDNF). We examined the time course of BDNF expression in C57BL/6 mouse brain following repeated exposure (1/day × 5 days/week × 2 weeks) to sublethal doses of VX (0.2 LD(50) and 0.4 LD(50)). BDNF messenger RNA expression was significantly (p LD(50) VX exposure. BDNF protein expression, however, was only increased in the CA3 region of the hippocampus. Whether increased BDNF in response to sublethal doses of VX exposure is an adaptive response to prevent cellular damage or a precursor to impending brain damage remains to be determined. If elevated BDNF is an adaptive response, exogenous BDNF may be a potential therapeutic target to reduce the toxic effects of nerve agent exposure. PMID:22240983

  2. Organophosphorus flame retardants (PFRs) in human breast milk from several Asian countries.

    Science.gov (United States)

    Kim, Joon-Woo; Isobe, Tomohiko; Muto, Mamoru; Tue, Nguyen Minh; Katsura, Kana; Malarvannan, Govindan; Sudaryanto, Agus; Chang, Kwang-Hyeon; Prudente, Maricar; Viet, Pham Hung; Takahashi, Shin; Tanabe, Shinsuke

    2014-12-01

    In this study, the concentrations of 10 organophosphorus flame retardants (PFRs) were determined in 89 human breast milk samples collected from Japan, the Philippines and Vietnam. Among the targeted PFRs, tris(2-chloroexyl) phosphate (TCEP) and triphenyl phosphate (TPHP) were the predominant compounds and were detected in more than 60% of samples in all three countries. The concentrations of PFRs in human breast milk were significantly higher (pVietnam (median 10 ng g(-1) lipid wt.). The present results suggest that the usage of products containing PFRs in the Philippines is higher than those of Japan and Vietnam. Comparing with a previous literature survey in Sweden, the levels of PFRs in human breast milk from the Philippines were 1.5-2 times higher, whereas levels in Japan and Vietnam were 4-20 times lower, suggesting that these differences might be due to their variation in the usage of flame-retarded products utilized in each country. When daily intake of PFRs to infants via human breast milk was estimated, some individuals accumulated tris(2-butoxyethyl) phosphate (TBOEP) and TCEP were close to reference dose (RfD). This is the first report to identify PFRs in human breast milk samples from Asian countries. PMID:24630247

  3. The Myth of Neutral Taxation

    OpenAIRE

    Murray N. Rothbard

    1981-01-01

    Economists have long believed that government’s tax and expendi- ture policy either is, or can readily be made to be, neutral to the market. Free-market economists have advocated such neutrality of government, and even economists favoring redistributive actions by government have believed that the service activities and the re- distributive activities of government can easily be distinguished, at least in concept. The purpose of this paper is to examine the nature and implications of fiscal...

  4. The Economics of Net Neutrality

    OpenAIRE

    Hahn, Robert W.; Wallsten, Scott

    2006-01-01

    This essay examines the economics of "net neutrality" and broadband Internet access. We argue that mandating net neutrality would be likely to reduce economic welfare. Instead, the government should focus on creating competition in the broadband market by liberalizing more spectrum and reducing entry barriers created by certain local regulations. In cases where a broadband provider can exercise market power the government should use its antitrust enforcement authority to police anticompetitiv...

  5. Neutral theory in community ecology

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    One of the central goals of community ecology is to understand the forces that maintain species diversity within communities. The traditional niche-assembly theory asserts that species live together in a community only when they differ from one another in resource uses. But this theory has some difficulties in explaining the diversity often observed in specie-rich communities such as tropical forests. As an alternative to the niche theory, Hubbell and other ecologists introduced a neutral model. Hubbell argues that the number of species in a community is controlled by species extinction and immigration or speciation of new species. Assuming that all individuals of all species in a trophically similar com-munity are ecologically equivalent, Hubbell's neutral theory predicts two important statistical distributions. One is the asymptotic log-series distribution for the metacommunities under point mutation speciation, and the other is the zero-sum multinomial distribution for both local communities under dispersal limitation and metacommunities under random fission speciation. Unlike the niche-assembly theory, the neutral theory takes similarity in species and individuals as a starting point for investigating species diversity. Based on the fundamental processes of birth, death, dispersal and spe-ciation, the neutral theory provided the first mechanistic explanation of species abundance distribution commonly observed in natural communities. Since the publication of the neutral theory, there has been much discussion about it, pro and con. In this paper, we summarize recent progress in the assumption, prediction and speciation mode of the neutral theory, including progress in the theory itself, tests about the assumption of the theory, prediction and speciation mode at the metacommunity level. We also suggest that the most important task in the future is to bridge the niche-assembly theory and the neutral theory, and to add species differences to the neutral theory and

  6. Cold ion-neutral reactions

    OpenAIRE

    Hall, Felix Henry Joynson

    2013-01-01

    Cold ion-neutral reactive processes were studied in an hybrid trap down to average collision energies /k_B > 20 mK. The atomic ion-neutral systems Ca^+ + Rb and Ba^+ + Rb were studied, and the results interpreted with high-level quantum chemical and quantum scattering calculations. Three reactive processes were found to be in competition, namely non-radiative charge transfer induced by non-adiabatic couplings between potential energy surfaces, radiative charge transfer, and radiative associat...

  7. Two-dimensional supramolecular networks via C-H$\\cdots$Cl and N-H$\\cdots$Cl interactions utilizing bidentate neutral pyridine amide coordinated MnIICl2 tectons

    Indian Academy of Sciences (India)

    Wilson Jacob; Rabindranath Mukherjee

    2008-09-01

    Reaction of -(phenyl)-2-pyridinecarboxamide (HL1) and -(-tolyl)-2-pyridinecarboxamide (HL2) ligands with MnCl2.4H2O affords complexes [(HL1)2MnCl2] 1 and [(HL2)2MnCl2] 2. The structures of 1 and 2 were determined by three-dimensional X-ray crystallography revealing that the MnII ions assume distorted octahedral geometry with coordination by two HL1/HL2 ligands providing two pyridine N and two amide O and two chloride ions. Notably, secondary interactions [C-H$\\cdots$Cl (pyridine 3-H hydrogen) and N-H$\\cdots$Cl (amide NH hydrogen)] triggered by MnII-coordinated chloride ions acting as hydrogen bonding acceptors generate self-complementary dimeric tectons, which lead to 2D supramolecular architectures.

  8. Detections of eleven organophosphorus insecticides and one herbicide threatening Pacific salmonids, Oncorhynchus spp., in California, 1991-2010.

    Science.gov (United States)

    Lisker, Emily B; Ensminger, Michael P; Gill, Sheryl L; Goh, Kean S

    2011-10-01

    California's surface water monitoring results from 1991 through 2010 were analyzed to determine whether 12 organophosphorus insecticides and herbicides (i.e., azinphos methyl, bensulide, dimethoate, disulfoton, ethoprop, fenamiphos, methamidophos, methidathion, methyl parathion, naled, phorate, and phosmet) and their degradates have been detected above maximum concentration limits (MCLs) in Pacific salmonid habitats. Methidathion, methyl parathion, phorate, phosmet, and the oxygen analogue of naled (DDVP) detections exceeded MCLs. Methyl parathion detections may be accounted for by monthly use trends, while methidathion detections may be explained by yearly use trends. There were inadequate phorate, phosmet, or DDVP data to evaluate for correlations with use. PMID:21710164

  9. Effects of organophosphorus donors in the extraction of Uranium(VI) with N-acetyl benzamide in chloroform

    International Nuclear Information System (INIS)

    The liquid-liquid extraction of Uranium(VI) from aqueous nitrate solution by a mixture of N-acetyl benzamide and Organophosphorus donors in chloroform is reported. Concentration of the metal was measured by fluorescence technique and synergism was observed in the extraction of Uranium(VI). Stoichiometries of extracted species in both individual and mixed extraction were ascertained by slope ratio analysis. From the extraction data, overall equilibrium constants for binary and ternary extractions were calculated. Thermodynamic parameters controlling the nature of extraction were also evaluated. (author)

  10. Vendor neutral archive in PACS

    Directory of Open Access Journals (Sweden)

    Tapesh Kumar Agarwal

    2012-01-01

    Full Text Available 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.

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

    International Nuclear Information System (INIS)

    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.

  12. Organophosphorus flame retardants and phthalate esters in indoor dust from different microenvironments: Bioaccessibility and risk assessment.

    Science.gov (United States)

    He, Ruiwen; Li, Yunzi; Xiang, Ping; Li, Chao; Zhou, Chunyang; Zhang, Shujun; Cui, Xinyi; Ma, Lena Q

    2016-05-01

    Incidental ingestion of indoor dust is an important pathway for human exposure to organophosphorus flame retardants (OPFRs) and phthalate esters (PAEs). However, little is known about their bioaccessibility in indoor dust. In this study, indoor dust samples were collected from houses, offices, public microenvironments (PMEs), and university dorms, and physiologically based extraction test (PBET) was used to measure the bioaccessibility of OPFRs and PAEs in these dust samples. Total concentrations of OPFRs in dust samples ranged from 0.01 to 63.2 μg g(-1), with significantly lower concentrations in dorm dust (median = 0.30 μg g(-1)) than those in houses (3.12), offices (5.94), and PMEs (11.6). Total PAEs ranged from 5.49 to 2161 μg g(-1) with significantly lower concentrations in dorm dust (379 μg g(-1)) than those in the other three types of dust (767, 515, and 731 μg g(-1)). When subject to PBET, the bioaccessibility of OPFRs ranged from 8.18% (triphenyl phosphate) to 54.5% (Tris(2-chloroisopropyl) phosphate) for OPFRs, and from 1.21% (di-2-ethylhexyl phthalate, DEHP) to 81.1% (dimethyl phthalate) for PAEs. Estimated exposure doses for adults and infants to OPFRs via dust ingestion were much lower than the reference doses (RfD), but intake dose of DEHP for infants was higher than the RfD of 20 μg kg(-1) d(-1). However, the DEHP intake dose did not exceed the RfD after incorporating bioaccessibility into risk assessment. Our data indicated the importance of considering contaminant bioaccessibility during risk assessment of indoor dust. PMID:26585356

  13. Dialkylphosphates (DAPs) in fruits and vegetables may confound biomonitoring in organophosphorus insecticide exposure and risk assessment.

    Science.gov (United States)

    Zhang, Xiaofei; Driver, Jeffrey H; Li, Yanhong; Ross, John H; Krieger, Robert I

    2008-11-26

    Trace residues of organophosphorus (OP) pesticides are associated with fruits and vegetables that have been sprayed with those OP pesticides to guard against insect pests. Human dietary exposure to these OP pesticides is commonly estimated by measuring the amount of OP metabolites in urine, assuming a stoichiometric relationship between a metabolite and its parent insecticide. Dialkylphosphates (DAPs) are the OP metabolites that are most often used as markers in such biomonitoring studies. However, abiotic hydrolysis, photolysis, and plant metabolism can convert OP chemicals (OP residues) to DAP residues on or in the fruits and vegetables. To evaluate the extent of these conversions, OPs and DAPs were measured in 153 produce samples. These samples from 2 lots were known to contain OP insecticide residues based on routine monitoring by California producers and shippers. A total of 12 OPs were quantified, including mevinphos, naled, acephate, methamidophos, oxidemeton-methyl, azinphos-methyl, dimethoate, malathion, methidathion, phosmet, chlorpyrifos, and diazinon. All OP insecticide residues were below their respective residue tolerances in 2002-2004. A total of 91 of 153 samples (60%) contained more DAP residues than parent OPs. The mean mole fractions [DAPs/(DAPs + OPs)] for the first and second lots of produce were 0.62 and 0.50, respectively, and the corresponding geometric means were 0.55 and 0.34. The corresponding mean mole ratios (DAPs/OP) were 7.1 and 3.4, with geometric means of 2.1 and 0.9. Any preformed DAPs ingested in the diet that are excreted in urine may inflate the estimated absorbed OP insecticide doses in occupational and environmental studies. In subsequent prospective studies, time-dependent production of dimethylphosphate (DMP) and dimethylthiophosphate (DMTP) in strawberries and leaves following malathion sprays occurred concomitant with the disappearance of the parent insecticide and its oxon. DAPs are more persistent in plants and produce

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

    International Nuclear Information System (INIS)

    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 (T3), thyroxine (T4) 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 T3 and T4 levels, mephosfolan increased T4 and decreased T3 levels, whereas phosfolan pesticide decreased T4 and increased T3 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.

  15. Mechanism and kinetics study on the OH-initiated oxidation of organophosphorus pesticide trichlorfon in atmosphere

    International Nuclear Information System (INIS)

    Trichlorfon [O,O-dimethyl-(2,2,2-trichloro-1-hydroxy-ethyl) phosphonate] (TCF) is a kind of widely used organophosphorus pesticides. In this paper, the mechanism and possible oxidation products for the OH-initiated reactions of TCF are studied at the MPWB1K/6–311 + G(3df,2p)//MPWB1K/6–31 + G(d,p) level. The study shows that H abstraction reaction from the CH3 group and the CH group as well as OH addition reaction to the P atom are energetically favorable for the reactions of TCF and the main products are (CH3O)2POOH (P1), CCl3CHOHPOOH(OCH3) (P2), CH3OPO2 (P3), CCl3COPO(OCH3)2 (P6) and HCHO. On the basis of the quantum chemical information, the kinetic calculation is performed and the rate constants are calculated over a temperature range of 200–800 K using the transition state theory and canonical variational transition state theory with small-curvature tunneling effect. The Arrhenius formulas of rate constants with the temperature are fitted and the lifetimes of the reaction species in the troposphere are estimated according to the rate constants, which can provide helpful information for the model simulation study. - Highlights: ► The H-abstracted reaction and OH addition reaction are favorable channels. ► The Arrhenius formulas of rate constants with the temperature are fitted. ► The rate constants of TCF relative to OH radical is 4.95 × 10−15 cm3 molecule−1 s−1.

  16. Paraoxonase 1 (PON1) modulates the toxicity of mixed organophosphorus compounds

    International Nuclear Information System (INIS)

    A transgenic mouse model of the human hPON1Q192R polymorphism was used to address the role of paraoxonase (PON1) in modulating toxicity associated with exposure to mixtures of organophosphorus (OP) compounds. Chlorpyrifos oxon (CPO), diazoxon (DZO), and paraoxon (PO) are potent inhibitors of carboxylesterases (CaE). We hypothesized that a prior exposure to these OPs would increase sensitivity to malaoxon (MO), a CaE substrate, and the degree of the effect would vary among PON1 genotypes if the OP was a physiologically significant PON1 substrate in vivo. CPO and DZO are detoxified by PON1. For CPO hydrolysis, hPON1R192 has a higher catalytic efficiency than hPON1Q192. For DZO hydrolysis, the two alloforms have nearly equal catalytic efficiencies. For PO hydrolysis, the catalytic efficiency of PON1 is too low to be physiologically relevant. When wild-type mice were exposed dermally to CPO, DZO, or PO followed 4-h later by increasing doses of MO, toxicity was increased compared to mice receiving MO alone, presumably due to CaE inhibition. Potentiation of MO toxicity by CPO and DZO was greater in PON1-/- mice, which have greatly reduced capacity to detoxify CPO or DZO. Potentiation by CPO was more pronounced in hPON1Q192 mice than in hPON1R192 mice due to the decreased efficiency of hPON1Q192 for detoxifying CPO. Potentiation by DZO was similar in hPON1Q192 and hPON1R192 mice, which are equally efficient at hydrolyzing DZO. Potentiation by PO was equivalent among all four genotypes. These results indicate that PON1 status can have a major influence on CaE-mediated detoxication of OP compounds.

  17. 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. PMID:27328881

  18. Levels of Blood Organophosphorus Flame Retardants and Association with Changes in Human Sphingolipid Homeostasis.

    Science.gov (United States)

    Zhao, Fanrong; Wan, Yi; Zhao, Haoqi; Hu, Wenxin; Mu, Di; Webster, Thomas F; Hu, Jianying

    2016-08-16

    While a recent toxicological study has shown that organophosphorus flame retardants (OPFRs) may disrupt sphingolipid homeostasis, epidemiologic evidence is currently lacking. In this study, a total of 257 participants were recruited from Shenzhen, China. Eleven OPFRs were for the first time simultaneously determined in the human blood samples by ultraperformance liquid chromatography and tandem mass spectrometry. Six OPFRs, tributyl phosphate (TNBP), 2-ethylhexyl diphenyl phosphate (EHDPP), tris(2-chloroisopropyl) phosphate (TCIPP), tris(2-butoxyethyl) phosphate (TBOEP), triethyl phosphate (TEP), and TPHP, were detectable in at least 90% of participants, with median concentrations of 37.8, 1.22, 0.71, 0.54, 0.49, and 0.43 ng/mL, respectively. Sphingomyelin (SM) levels in the highest quartile of EHDPP, TPHP, TNBP, TBOEP, TEP, and TCIPP were 45.3% [95% confidence interval; 38.1%, 53.0%], 51.9% (45.5%, 58.6%), 153.6% (145.1%, 162.3%), 20.6% (14.5%, 27.0%), 59.0% (52.1%, 66.2%), and 62.8% (55.2%, 70.6%) higher than those in the lowest quartile, respectively, after adjusting for covariates. Sphingosine 1-phosphate (S1P) levels in the highest quartile of EHDPP, TPHP, and TNBP were 36% (-39%, -33%), 16% (-19%, -14%), and 36% (-38%, -33%) lower than those in the lowest quartile, respectively. A similar pattern emerged when exposures were modeled continuously. We for the first time found the associations between OPFRs and changes in human sphingolipid homeostasis. PMID:27434659

  19. Mechanism and kinetics study on the OH-initiated oxidation of organophosphorus pesticide trichlorfon in atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Yuan; Zhang, Chenxi; Yang, Wenbo; Hu, Jingtian [Environment Research Institute, Shandong University, Jinan 250100 (China); Sun, Xiaomin, E-mail: sxmwch@sdu.edu.cn [Environment Research Institute, Shandong University, Jinan 250100 (China); State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy Of Science, Lanzhou 730000 (China)

    2012-03-01

    Trichlorfon [O,O-dimethyl-(2,2,2-trichloro-1-hydroxy-ethyl) phosphonate] (TCF) is a kind of widely used organophosphorus pesticides. In this paper, the mechanism and possible oxidation products for the OH-initiated reactions of TCF are studied at the MPWB1K/6-311 + G(3df,2p)//MPWB1K/6-31 + G(d,p) level. The study shows that H abstraction reaction from the CH{sub 3} group and the CH group as well as OH addition reaction to the P atom are energetically favorable for the reactions of TCF and the main products are (CH{sub 3}O){sub 2}POOH (P1), CCl{sub 3}CHOHPOOH(OCH{sub 3}) (P2), CH{sub 3}OPO{sub 2} (P3), CCl{sub 3}COPO(OCH{sub 3}){sub 2} (P6) and HCHO. On the basis of the quantum chemical information, the kinetic calculation is performed and the rate constants are calculated over a temperature range of 200-800 K using the transition state theory and canonical variational transition state theory with small-curvature tunneling effect. The Arrhenius formulas of rate constants with the temperature are fitted and the lifetimes of the reaction species in the troposphere are estimated according to the rate constants, which can provide helpful information for the model simulation study. - Highlights: Black-Right-Pointing-Pointer The H-abstracted reaction and OH addition reaction are favorable channels. Black-Right-Pointing-Pointer The Arrhenius formulas of rate constants with the temperature are fitted. Black-Right-Pointing-Pointer The rate constants of TCF relative to OH radical is 4.95 Multiplication-Sign 10{sup -15} cm{sup 3} molecule{sup -1} s{sup -1}.

  20. The Mechanism of Organophosphorus Pesticide-Induced Inhibition of Cytolytic Activity of Killer Cells

    Institute of Scientific and Technical Information of China (English)

    Qing Li; Tomoyuki Kawada

    2006-01-01

    The main toxicity of organophosphorus pesticides (OPs) is neurotoxicity, which is caused by the inhibition of acetylcholinesterase. OPs also affect immune responses including effects on antibody production, IL-2 production,T cell proliferation, decreasement of CD5 cells, and increasement of CD26 cells and autoantibodies. However, there have been few papers investigating the mechanism of OP-induced inhibition of cytolytic activity of killer cells. This study reviews the new mechanism of OP-induced inhibition of activities of natural killer (NK),lymphokine-activated killer (LAK) and cytotoxic T lymphocytes (CTL). NK, LAK and CTL induce cell death in tumor or virus-infected target cells by two main mechanisms. The first mechanism is direct release of cytolytic granules that contain perforin, granzymes, and granulysin by exocytosis to kill target cells, which is called the granule exocytosis pathway. The second mechanism is mediated by the Fas !igand (Fas-L)/Fas pathway. To date, it has been reported that OPs inhibit NK, LAK and CTL activities by at least the following three mechanisms: 1) OPs impair the granule exocytosis pathway of NK, LAK and CTL cells by inhibiting the activity of granzymes, and by decreasing the intracellular level of perforin, granzyme A and granulysin, which was mediated by inducing degranulation of NK cells and by inhibiting the transcript of mRNA of perforin, granzyme A and granulysin; 2)OPs impair the FasL/Fas pathway of NK, LAK and CTL cells, as investigated by using perforin-knockout mice, in which the granule exocytosis pathway of NK cells does not function and only the FasL/Fas pathway remains functional; 3) OPs induce apoptosis of immune cells.

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

    International Nuclear Information System (INIS)

    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 [3H]thymidine incorporation with a very similar potency (IC50 between 45 and 57 μM). Among the other metabolites, PNP was the most potent (IC50 = 70-80 μM), while TCP and IMP were much less effective (IC50 > 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 [3H]thymidine incorporation when cells were synchronized in the G0/G1 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 G0/G1 to the S/G2 phase of the cell cycle may be particularly sensitive to the action of these compounds

  2. Crystal structure of patatin-17 in complex with aged and non-aged organophosphorus compounds.

    Directory of Open Access Journals (Sweden)

    Sanjeeva J Wijeyesakere

    Full Text Available Patatin is a non-specific plant lipase and the eponymous member of a broad class of serine hydrolases termed the patatin-like phospholipase domain containing proteins (PNPLAs. Certain PNPLA family members can be inhibited by organophosphorus (OP compounds. Currently, no structural data are available on the modes of interaction between the PNPLAs and OP compounds or their native substrates. To this end, we present the crystal structure of patatin-17 (pat17 in its native state as well as following inhibition with methyl arachidonyl fluorophosphonate (MAFP and inhibition/aging with diisopropylphosphorofluoridate (DFP. The native pat17 structure revealed the existence of two portals (portal1 and portal2 that lead to its active-site chamber. The DFP-inhibited enzyme underwent the aging process with the negatively charged phosphoryl oxygen, resulting from the loss of an isopropyl group, being within hydrogen-binding distance to the oxyanion hole. The MAFP-inhibited pat17 structure showed that MAFP did not age following its interaction with the nucleophilic serine residue (Ser77 of pat17 since its O-methyl group was intact. The MAFP moiety is oriented with its phosphoryl oxygen in close proximity to the oxyanion hole of pat17 and its O-methyl group located farther away from the oxyanion hole of pat17 relative to the DFP-bound state. The orientation of the alkoxy oxygens within the two OP compounds suggests a role for the oxyanion hole in stabilizing the emerging negative charge on the oxygen during the aging reaction. The arachidonic acid side chain of MAFP could be contained within portals 1 or 2. Comparisons of pat17 in the native, inhibited, and aged states showed no significant global conformational changes with respect to their Cα backbones, consistent with observations from other α/β hydrolases such as group VIIA phospholipase A2.

  3. IN VITRO SENSITIVITY OF CHOLINESTERASES AND [3H]OXOTREMORINE-M BINDING IN HEART AND BRAIN OF ADULT AND AGING RATS TO ORGANOPHOSPHORUS ANTICHOLINESTERASES

    OpenAIRE

    Mirajkar, Nikita; Pope, Carey N.

    2008-01-01

    Organophosphorus (OP) insecticides elicit toxicity via acetylcholinesterase inhibition, allowing acetylcholine accumulation and excessive stimulation of cholinergic receptors. Some OP insecticides bind to additional macromolecules including butyrylcholinesterase and cholinergic receptors. While neurotoxicity from OP anticholinesterases has been extensively studied, effects on cardiac function have received less attention. We compared the in vitro sensitivity of acetylcholinesterase, butyrylch...

  4. Broad-specificity immunoassay for O,O-diethyl organophosphorus pesticides: Application of molecular modeling to improve assay sensitivity and study antibody recognition

    Science.gov (United States)

    A monoclonal antibody (MAb) against 4-(diethoxyphosphorothioyloxy)benzoic acid (hapten 1) was raised and used to develop a broad-specificity competitive indirect enzyme-linked immunosorbent assay (ciELISA) for 14 O,O-diethyl organophosphorus pesticides (OPs). Computer-assisted molecular modeling was...

  5. Manganese(III) Acetate-Promoted Cross-Coupling Reaction of Benzothiazole/Thiazole Derivatives with Organophosphorus Compounds under Ball-Milling Conditions.

    Science.gov (United States)

    Li, Liang; Wang, Jun-Jie; Wang, Guan-Wu

    2016-07-01

    The first solvent-free manganese(III) acetate-promoted reaction of benzothiazole/thiazole derivatives with organophosphorus compounds including phosphine oxides, phosphinate ester, and phosphonate diester has been efficiently developed under ball-milling conditions, providing a highly efficient and green protocol to structurally diverse C2-phosphonylated benzothiazole/thiazole derivatives with remarkable functional group tolerance and excellent yields. PMID:27248000

  6. A simple, rapid, and high-throughput fluorescence polarization immunoassay for simultaneous detection of organophosphorus pesticides in vegetable and environmental water samples

    Science.gov (United States)

    A simple, rapid, and high-throughput fluorescent polarization immunoassay (FPIA) for simultaneous determination of organophosphorus pesticides (OPs) was developed. Three haptens were labeled with a fluorescein probe and used as tracers to develop a homogenous FPIA using a broad-specificity monoclon...

  7. Production and characterization of a broad-specificity polyclonal antibody for O,O-diethyl organophosphorus pesticides and a quantitative structure-activity relationship study of antibody recognition

    Science.gov (United States)

    Polyclonal antibody (PAb) with broad-specificity for O,O-diethyl organophosphorus pesticides (OPs) against a generic hapten, 4-(diethoxyphosphoro thioyloxy) benzoic acid, was produced. The obtained PAb showed high sensitivity to seven commonly used O,O-diethyl OPs in a competitive indirect enzyme-l...

  8. Organohalogen and organophosphorus pesticides in mixed feed rations: findings from FDA's domestic surveillance during fiscal years 1989-1994.

    Science.gov (United States)

    Lovell, R A; McChesney, D G; Price, W D

    1996-01-01

    During Fiscal Years 1989-1994, the U.S. Food and Drug Administration (FDA) collected and analyzed 545 domestic surveillance samples of mixed feed rations (172 for cattle, 125 for poultry, 83 for swine, 61 for pets, 56 for fish, and 48 miscellaneous). All samples were analyzed by gas-liquid chromatography for organohalogen and organophosphorus pesticides. Of the 545 samples, 88 (16.1%) did not contain detectable pesticide residues. In the 457 samples with detectable pesticide levels, 804 residues (654 quantitable and 150 trace) were found. None of these 804 residues exceeded regulatory guidance. Malathion, chlorpyrifos-methyl, diazinon, chlorpyrifos, and pirimiphos-methyl were the most commonly detected pesticides. These 5 organophosphorus pesticides accounted for 93.4% of all pesticide residues detected (malathion, 52.9%; chlorpyrifos-methyl, 25.2%; diazinon, 7.7%; chlorpyrifos, 4.9%; and pirimiphos-methyl, 2.7%). Their median values in samples containing quantitable levels ranged from 0.014 to 0.098 ppm. The most commonly detected organohalogen compounds were methoxychlor, DDE, PCB, dieldrin, pentachloronitrobenzene, and lindane. These 6 compounds combined accounted for only 4.1% of all residues detected. FDA is continuing its pesticide surveillance of feeds to help ensure animal safety and prevent violative residues in food derived from animals. PMID:8920144

  9. Method for the determination of organophosphorus and pyrethroid pesticides in food via gas chromatography with electron-capture detection.

    Science.gov (United States)

    Hunter, Ronald E; Riederer, Anne M; Ryan, P Barry

    2010-02-10

    We have developed a rapid, high-throughput, accurate, multiresidue method for the analysis of selected organophosphorus and pyrethroid pesticides in a variety of food samples suitable for use in public health and epidemiologic investigations of high-use pesticides using modifications of existing methods. The procedure involves a pesticide extraction from the food sample with acetonitrile followed by a salting-out with NaCl and cleanup of the extract with a multilayer solid-phase extraction cartridge composed of a Supelclean ENVI-CARB-II top layer and a primary-secondary amine bottom layer separated by a polyethylene frit. To evaluate the method, we performed fortification studies at 50, 100, and 200 ng/g for 3 organophosphorus and 4 pyrethroid pesticides in 16 different foods. Instrumental analysis was carried out by capillary gas chromatography with electron-capture detection (GC-ECD). Confirmatory analysis was performed by GC coupled with mass spectrometry (MS) in the selected-ion monitoring (SIM) mode. Average recoveries for each fortification level ranged from 49 to 146% with 80% of recoveries between 80 and 120%. PMID:20073464

  10. Poly(ionic liquid) immobilized magnetic nanoparticles as new adsorbent for extraction and enrichment of organophosphorus pesticides from tea drinks.

    Science.gov (United States)

    Zheng, Xiaoyan; He, Lijun; Duan, Yajing; Jiang, Xiuming; Xiang, Guoqiang; Zhao, Wenjie; Zhang, Shusheng

    2014-09-01

    New poly(ionic liquid) immobilized magnetic nanoparticles (PIL-MNPs) were synthesized via co-polymerization of 1-vinyl-3-hexylimidazolium-based ionic liquid and vinyl-modified magnetic particles and were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and magnetic measurements. The PIL-MNPs were utilized as adsorbent phases in magnetic solid-phase extraction (MSPE). The extraction and enrichment efficiency were evaluated by using four organophosphorus pesticides (parathion, fenthion, phoxim and temephos) as test analytes. Various parameters, such as amount of adsorbent, adsorption time, desorption solvent and time, and ionic strength were investigated. The proposed method showed good linearity for the analytes in the concentration range of 1-200μgL(-1) with a correlation coefficient (R)>0.9963. Low limit of detection of 0.01μgL(-1) and high enrichment factors ranging from 84 to 161 were achieved. The proposed method has been successfully used to determine organophosphorus pesticides from three tea drink samples with satisfactory recovery of 81.4-112.6% and RSDs of 4.5-11.3%. The PIL-MNP adsorbent can be reused for 20 times without a noticeable decrease in extraction efficiency. PMID:25022482

  11. THE SPECTRUM OF INTERMEDIATE SYNDROME FOLLOWING ACUTE ORGANOPHOSPHORUS POISONING: A RETROSPECTIVE COHORT STUDY FROM A TEACHING HOSPITAL OF CHHATTISGARH

    Directory of Open Access Journals (Sweden)

    Murthy

    2014-05-01

    Full Text Available Intermediate syndrome is a common complication found in patients with organo-phosphorus poisoning. The aim of this study was to find its incidence in this tribal dominated area of Chhattisgarh state. This is a retrospective study carried out at the ICU of a teaching Medical College hospital. In a period of one year, 720 cases of acute poisoning were admitted in the medical ICU ward, out of which, 682 cases (94.7% were of organo-phosphorus poisoning. 64 cases (9.3% had signs & symptoms of intermediate syndrome, which included inability to flex the neck, respiratory difficulty, convulsions and other features. All the 64 cases of intermediate syndrome required ventilatory support. Male: female ratio was 8:10. The commonest compound implicated in poisoning was Fenthion. Mortality was 18%. Patients with respiratory muscle weakness & proximal muscle paresis were the definitive predictors for the development of intermediate syndrome. Early recognition & prompt treatment has often proved successful, but, in mixed poisoning, recovery is variable and unpredictable.

  12. Comparison of Two Procedures for Extraction and Clean-up of Organophosphorus and Pyrethroid Pesticides in Sediment

    Institute of Scientific and Technical Information of China (English)

    WANG Li-Gang; JIANG Xin; YAN Dong-Yun; S.FORSTER; D.MARTENS

    2004-01-01

    Two procedures were compared for extraction and clean-up of 20 organophosphorus and 19 pyrethroid pesticides in sediment to identify the more effective procedure for groups of pesticides or individual compounds. In Procedure Ⅰ,methanol/water and n-hexane were used for extraction,and 1:10 (v/v) dichloromethane in n-hexane and acetone were used as eluents for eluting the analyte through the cartridge,with one evaporating steps on a rotary evaporator and two eluting steps on the cartridge. n-hexane/acetone (2:1,v/v) was used for extraction and elution in Procedure Ⅱ with one evaporating step on a rotary evaporator and one eluting step on the cartridge. All extractions were performed under an ultrasonic bath and gas chromatography and mass spectrometry were utilized for measurements. Procedure Ⅱ was developed as a rapid,timesaving,less costly and safer substitute for Procedure Ⅰ which was an old method. Procedure Ⅱ was more effective for ahnost all the organophosphorus pesticides tested and 11 of the 19 pyrethroid pesticides,while Procedure Ⅰ was more appropriate for analysis of 5 pyrethroid pesticides. However,recoveries of most pyrethroid pesticides were fairly low. Thus,further studies should focus on adjustment and formulation of solvents for more efficient extraction and clean-up of pyrethroid pesticides from sediment samples.

  13. 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.

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

    International Nuclear Information System (INIS)

    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 T0.5 (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

  15. Neutral beams for magnetic fusion

    International Nuclear Information System (INIS)

    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 (1014 particles/cm3) 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

  16. Neutral B meson flavor tagging

    CERN Document Server

    Wilson, R J

    2001-01-01

    We present an investigation of the use of net charge and kaon identification to tag the flavor of neutral B mesons. The net charge of the neutral B meson decay products is zero if all charged particles are used and slightly non-zero if only undiscriminated hadronic final states are used. The net charge of the kaons alone correctly tags the identity of the neutral meson in at least a third of all decays. We have parametrized the particle identification capability of several techniques, such as dE/dx in time projection chambers, LEP/SLC ring-imaging chambers and an enhanced BaBar DIRC. Using these parametrisations we compare the relative tagging power of each technique to that of an ideal detector. (8 refs).

  17. ATF neutral beam injection system

    International Nuclear Information System (INIS)

    The Advanced Toroidal Facility is a stellarator torsatron being built at Oak Ridge National Laboratory to investigate improved plasma confinement schemes. Plasmas heating will be carried out predominantly by means of neutral beam injection. This paper describes the basic parameters of the injection system. Numerical calculations were done to optimize the aiming of the injectors. The results of these calculations and their implications on the neutral power to the machine are elaborated. The effects of improving the beam optics and altering the focal length on the power transmitted to the plasma are discussed

  18. 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.

  19. ITER Neutral Beam Injection System

    International Nuclear Information System (INIS)

    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)

  20. Net Neutrality in the Netherlands

    NARCIS (Netherlands)

    N. van Eijk

    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

  1. Neutralization kinetics for polonium-218

    International Nuclear Information System (INIS)

    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 diffusion coefficient of polonium-218 under various concentrations of trace gas NO2 in nitrogen was measured. The mobilities of Po+ and PoO2+ 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 NO2 or H2O in nitrogen. When PoO2+ is formed, the electron-transfer mechanism dominates the neutralization process. The electron is transferred to PoO2+ from molecules with lower ionization potentials. The ionization molecules with lower ionization potentials. The ionization potential of PoO2+ is also determined to be 10.44 +/- 0.05 eV

  2. Neutral Models with Generalised Speciation

    NARCIS (Netherlands)

    Haegeman, Bart; Etienne, Rampal S.

    2009-01-01

    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

  3. Earthworm-induced carboxylesterase activity in soil: Assessing the potential for detoxification and monitoring organophosphorus pesticides.

    Science.gov (United States)

    Sanchez-Hernandez, Juan C; Notario del Pino, J; Domínguez, Jorge

    2015-12-01

    Soil enzyme activities are attracting widespread interest due to its potential use in contaminant breakdown, and as indicators of soil deterioration. However, given the multiple environmental and methodological factors affecting their activity levels, assessment of soil pollution using these biochemical endpoints is still complex. Taking advantage of the well-known stimulatory effect of earthworms on soil microbes, and their associated enzyme activities, we explored some toxicological features of carboxylesterases (CbEs) in soils inoculated with Lumbricus terrestris. A microplate-scale spectrophotometric assay using soil-water suspensions was first optimized, in which kinetic assay parameters (Km, Vmax, dilution of soil homogenate, and duration of soil homogenization) were established for further CbE determinations. Optimal conditions included a soil-to-water ratio of 1:50 (w/v), 30-min of shaking, and 2.5mM of substrate concentration. As expected, CbE activity increased significantly in soils treated with L. terrestris. This bioturbed soil was used for exploring the role of CbE activity as a bioscavenger for organophosphorus (OP) pesticides. Soil treated with two formulations of chlorpyrifos revealed that CbE activity was a significant molecular sink for this pesticide, reducing its impact on soil microbial activity as shown by the unchanged dehydrogenase activity. Dose-dependent curves were adjusted to an exponential kinetic model, and the median ecological dose (ED50) for both pesticide formulations was calculated. ED50 values decreased as the time of pesticide exposure increased (14 d-ED50s=20.4-26.7 mg kg(-1), and 28 d-ED50s=1.8-2.3 mg kg(-1)), which suggested that chlorpyrifos was progressively transformed into its highly toxic metabolite chlorpyrifos-oxon, but simultaneously was inactivated by CbEs. These results were confirmed by in vitro assays that showed chlorpyrifos-oxon was a more potent CbE inhibitor (IC50=35.5-4.67 nM) than chlorpyrifos (0.41-0.84

  4. Swine models in the design of more effective medical countermeasures against organophosphorus poisoning.

    Science.gov (United States)

    Dorandeu, F; Mikler, J R; Thiermann, H; Tenn, C; Davidson, C; Sawyer, T W; Lallement, G; Worek, F

    2007-04-20

    Although the three most commonly used large mammal species in the safety assessment of drugs remain the dog, the macaque and the marmoset, swine, especially minipigs, have also been widely used over the years in many toxicological studies. Swine present a number of interesting biological and physiological characteristics. Similarities in skin properties with humans have led to extensive in vitro and in vivo studies. There is a specific interest in cardiovascular research, as well as in anaesthesiology and critical care medicine due to common features of swine and human physiology. Although knowledge of swine brain structure and functions remains incomplete, data does exist. The multiple blood sampling that is necessary in pharmacokinetic and toxicokinetic studies are possible, as well as multiparametric monitoring and interventions with equipment used in human clinical settings. Practicality (handling), scientific (stress reduction) and ethical (invasive monitoring) reasons have led research teams to incorporate anaesthesia into their paradigms which makes the analysis of data increasingly difficult. Although not substantiated by scientific data, the swine appears to have an intermediate position in the scale of public perception between non-human primates and animals commonly referred to as pets (i.e. dogs and cats) and rodents. The benefits of the swine model justify the use of these animals in the design of more effective medical countermeasures against known chemical warfare agents (nerve agents, vesicants and lung damaging agents). Exposure to organophosphorus (OP) pesticides represents a severe health issue in developing countries, while OP intoxication with the more lethal military nerve agents is not only of military concern but also a terrorist threat. Tailoring therapeutic regimens to the reality of OP poisoning is of the utmost importance when little experimental data and sparse human clinical data are available in the decision making process. We will

  5. Is it possible to reverse aged acetylcholinesterase inhibited by organophosphorus compounds? Insight from the theoretical study.

    Science.gov (United States)

    An, Yun; Zhu, Yali; Yao, Yuan; Liu, Junjun

    2016-04-14

    The main treatment for organophosphorus (OP) compound poisoning in clinics is to restore the activity of acetylcholinesterase (AChE) through oxime-induced reactivation of the phosphorylated OP-AChE adduct. It suffers from a competitive and irreversible aging reaction of the phosphorylated OP-AChE adduct, resulting in permanent inactivity of AChE. However, it was recently reported that N-methyl-2-methoxypyridinium species can act as methylating agents to methylate the methyl methane-phosphonate monoanion, in which the reaction mimics the reverse of the aging reaction of the phosphorylated OP-AChE adduct. If the aging reaction could be really reversed, the efficiency for the OP detoxification should be significantly improved, bringing up the possibility to develop an agent to reverse the aging process of the phosphorylated OP-AChE adduct. However, such a reaction with the N-methyl-2-methoxypyridinium species in the enzyme is still not reported so far. It is of great interest to know whether or not this reaction is observable in the enzyme, and more importantly, if it turns out to be not observable in the enzyme, why such a reaction proceeds quickly in aqueous solution but not in the enzyme. In the present study, we performed DFT calculations and quantum mechanical/molecular mechanical (QM/MM) calculations to reveal the fundamental mechanism for the methylation of both the methyl methane-phosphonate monoanion and the aged sarin-AChE adduct by N-methyl-2-methoxypyridinium species, respectively. The obtained results support the SN2 reaction mechanism, not the stepwise mechanism, for the methylation of the methyl methane-phosphonate monoanion by 9 reported N-methyl-2-methoxypyridinium compounds. The calculated free energy barriers are in good agreement with the experimental data. The methylation of the aged sarin-AChE adduct by one N-methyl-2-methoxypyridinium compound (labeled as compound 2) also employs the SN2 reaction mechanism with an extremely high free energy

  6. Swine models in the design of more effective medical countermeasures against organophosphorus poisoning

    International Nuclear Information System (INIS)

    Although the three most commonly used large mammal species in the safety assessment of drugs remain the dog, the macaque and the marmoset, swine, especially minipigs, have also been widely used over the years in many toxicological studies. Swine present a number of interesting biological and physiological characteristics. Similarities in skin properties with humans have led to extensive in vitro and in vivo studies. There is a specific interest in cardiovascular research, as well as in anaesthesiology and critical care medicine due to common features of swine and human physiology. Although knowledge of swine brain structure and functions remains incomplete, data does exist. The multiple blood sampling that is necessary in pharmacokinetic and toxicokinetic studies are possible, as well as multiparametric monitoring and interventions with equipment used in human clinical settings. Practicality (handling), scientific (stress reduction) and ethical (invasive monitoring) reasons have led research teams to incorporate anaesthesia into their paradigms which makes the analysis of data increasingly difficult. Although not substantiated by scientific data, the swine appears to have an intermediate position in the scale of public perception between non-human primates and animals commonly referred to as pets (i.e. dogs and cats) and rodents. The benefits of the swine model justify the use of these animals in the design of more effective medical countermeasures against known chemical warfare agents (nerve agents, vesicants and lung damaging agents). Exposure to organophosphorus (OP) pesticides represents a severe health issue in developing countries, while OP intoxication with the more lethal military nerve agents is not only of military concern but also a terrorist threat. Tailoring therapeutic regimens to the reality of OP poisoning is of the utmost importance when little experimental data and sparse human clinical data are available in the decision making process. We will

  7. Relationship between Acute Organophosphorus Pesticide Poisoning and Damages Induced by Free Radicals

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To study the relationship between abnormal reactions of free radicals in bodies of patients with acute organophosphorus pesticide poisoning (AOPP) and damages induced by free radicals. Methods 58 AOPP patients and 58 healthy adult volunteers (HAV) were enrolled in an independent samples control design, in which spectrophotometric methods were used to determine the concentrations of nitric oxide (NO) and lipoperoxides (LPO) in plasma, and LPO in erythrocytes, vitamin C (VC), vitamin E (VE) and b-carotene (b-CAR) in plasma as well as activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px) and acetylcholinesterase (AChE) in erythrocytes. Results Compared with the average values of every biochemical parameter in the HAV group, the average values of LPO in plasma and in erythrocytes, and NO in plasma in the AOPP group were significantly increased (P=0.000001), while the average values of VC, VE, a-CAR in plasma as well as SOD, CAT, GSH-Px and AChE in erythrocytes in the AOPP group were significantly decreased (P=0.000001). The findings of Pearson product-moment correlation analysis between the value of AChE in erythrocytes and the values of above biochemical parameters for 58 AOPP patients showed that there was a significant linear negative correlation between AChE in erythrocytes and LPO, NO in plasma, and LPO in erythrocytes (P=0.000001~0.001319), while there was a significant linear positive correlation between AChE in erythrocytes and VC, VE, a-CAR in plasma as well as SOD, CAT, GSH-Px in erythrocytes (P=0.000013~0.000824). The results of discriminant analysis of above chemical parameters for 58 AOPP patients and 58 HAV suggested that the correct rates of discriminant analysis were increased to 100 % when the values of AChE and LPO in plasma and in erythrocytes, or AChE and others, were jointly used for the discriminant analysis. Conclusion The findings of the present study suggest that a series of free radical

  8. A Novel Copper(Ⅱ) Coordination Polymer with Figure-of-eight-shaped Channels Occupied by Flexible Monodentate and Bidentate N,N'-bipyrdyl Ligands%A Novel Copper(Ⅱ) Coordination Polymer with Figure-of-eight-shaped Channels Occupied by Flexible Monodentate and Bidentate N,N'-bipyrdyl Ligands

    Institute of Scientific and Technical Information of China (English)

    PAN Peng-Bin; ZHANG Xin; YANG Jin-Xia; YIN Pei-Xiu; YAO Yuan-Gen

    2011-01-01

    A copper(Ⅱ) coordination polymer, [Cu3(HOA)2(bpp)4]n (1, HnOA = 3,3',4,4'- oxidiphthalic acid, bpp = 1,3-bis(4-pyridyl) propane), has been hydrothermally synthesized. The crystal structure is of monoclinic, space group P21/c with a = 11.544(3), b = 16.129(4), c = 21.181 (6) A, β = 98.848(5), V= 3897.0(2) A3, C84018N8H70Cu3, Mr = 1670.13, Z = 2, De = 1.423 g/cm^3, F(000) = 1722, μ = 0.887 mm^-1, R = 0.0878 and wR = 0.2583 for 8496 observed reflections (I 〉 2σ(I)). Single-crystal X-ray structural analysis reveals that 1 is a three-dimensional (3D) framework based on a two-dimensional (2D) mesomeric layer of alternating left- and fight-handed helical chains. The monodentate terminal and bidentate bridging bpp ligands in the same conformation are all encapsulated in the figure-of-eight-shaped channels, thus further stabilizing the whole three-dimensional framework.

  9. 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.

  10. Extraction profile of zirconium from HNO3 and Purex high-level waste solutions using organophosphorus extractants

    International Nuclear Information System (INIS)

    The extraction profile of Zr4+ from HNO3 and synthetic pressured heavy water reactor high level waste (PHWR-HLW) solutions has been studied using two important organophosphorus extractants from the minor actinide partitioning point of view. These are octyl (phenyl)-N,N-diisobutyl- carbamoylmethylphosphine oxide (CMPO) and Cyanex-923 (trialkyl phosphine oxide, TRPO). With CMPO, DZr increases with increasing HNO3 concentration up to ∼ 2 M and then it remains constant. From PHWR-HLW also, Zr could be easily extracted with CMPO solution. Using 30% TRPO/dodecane DZr was almost constant between 0.5 to 3.0 M HNO3 and then it slightly increases up to 6.6 M. From both the organic phases Zr could be stripped with different concentrations of oxalic acid. (author)

  11. A glassy carbon electrode modified with graphene and tyrosinase immobilized on platinum nanoparticles for sensing organophosphorus pesticides

    International Nuclear Information System (INIS)

    An amperometric biosensor is described for the detection of organophosphorus pesticides. It is based on the enzyme tyrosinase immobilized on platinum nanoparticles and the use of a glassy carbon electrode modified with graphene. Tyrosinase was immobilized on the electrode surface via electrostatic interaction between a monolayer of cysteamine and the enzyme. In the presence of catechol as a substrate, the pesticides chlorpyrifos, profenofos and malathion can be determined as a result of their inhibition of the enzyme which catalyzes the oxidation of catechol to o-quinone. Platinum nanoparticles and graphene effectively enhance the efficiency of the electrochemical reduction of o-quinone, thus improving sensitivity. Under optimum experimental conditions, the inhibition effect of the pesticides investigated is proportional to their concentrations in the lower ppb-range. The detection limits are 0.2, 0.8 and 3 ppb for chlorpyrifos, profenofos and malathion, respectively. The biosensor displays good repeatability and acceptable stability. (author)

  12. 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.

  13. A PRELIMINARY TRIAL OF THE MASS-TREATMENT OF URINARY BILHARZIASIS WITH AN ORGANO-PHOSPHORUS COMPOUND

    Directory of Open Access Journals (Sweden)

    I. Farahmandian

    1974-07-01

    Full Text Available In the course of an evaluation of various schistosomicidal drugs In Iran, the effect of an organo-phosphorus compound in the-treatment of 45 mild cases of urinary bilhariziasis was assessed and the drug was given in 3 doses of 10 mg/kg body weight each with 3-week intervals. Follow-up examinations undertaken 3 weeks after the 1st, 2nd and 3rd doses as well as 3 months after completion of therapy showed cure rates of 71, 82, 91 and 90% responsively. A reverse correlation was observed between the mean number of eggs excreted in the urine and the cure rate. Side-effects were mild and were observed in only 20% of the patients. In order of their frequency, they were abdumina1 pain, nausea, headache, vertigo and vomiting. The administration of Atropine together with each dose of the drug did not have any effect on the reduction of side-effects.

  14. Prolonged Apnea During Modified Electroconvulsive Therapy in a Patient of Suicidal Attempt by Organophosphorus Poisoning: A Case Report.

    Science.gov (United States)

    Dhakne, Rajesh; Mishra, Kshirod K; Kumar, Vinay; Khairkar, Praveen

    2016-06-01

    Organophosphorus (OP) pesticides are commonly used in agricultural fields to control pests in India. However, exposure to it can cause poisoning in humans and animals, or it can be taken intentionally as poison to commit suicide. We present a case of a 35-year-old suicidal man who developed prolonged apnea for almost 4 hours on day 13 of OP poisoning after brief general anesthesia induced by propofol and 1 mg/kg of suxamethonium, during the first session of the third cycle of modified electroconvulsive therapy, despite all due precautions. Such prolonged apnea secondary to complex interactions has been reported very rarely in literature. This case therefore, highlights the importance of careful evaluation and monitoring while giving anesthesia to OP-poisoning patients. PMID:26595234

  15. Radiative lifetimes of neutral neodymium

    International Nuclear Information System (INIS)

    This work is part of an on-going study of radiative properties of rare earth neutral atoms. This work is motivated by research needs in several disparate fields including astrophysics and lighting technology. Radiative lifetimes of 100 levels of neutral neodymium are measured using the technique of time-resolved laser-induced fluorescence on a slow atomic beam. Of the 100 levels, 3 are even parity ranging in energy from 25 746 to 26 835 cm-1, and the remaining 97 are odd parity ranging from 17 787 to 27 786 cm-1. This set of Nd i lifetimes represents a significant extension to the available published data, with 51 of the 100 level lifetimes measured for the first time. These data, which are accurate to ±5%, provide the absolute normalization for a large set of measured Nd i transition probabilities.

  16. Radiative lifetimes of neutral gadolinium

    Energy Technology Data Exchange (ETDEWEB)

    Den Hartog, E A; Bilty, K A; Lawler, J E, E-mail: eadenhar@wisc.edu, E-mail: biltyka@uwec.edu, E-mail: jelawler@wisc.edu [Department of Physics, University of Wisconsin, 1150 University Ave, Madison, WI 53706 (United States)

    2011-03-14

    The current work is part of an ongoing study of radiative properties of rare earth neutral atoms motivated by research needs in several disparate fields including astrophysics, laser chemistry and lighting technology. Time-resolved laser-induced fluorescence on a slow atomic beam has been used to measure radiative lifetimes, accurate to {+-}5%, for 136 levels of neutral gadolinium. Of the 136 levels, 6 are odd parity ranging in energy from 32 929 to 36 654 cm{sup -1}, and the remaining 130 are even parity ranging from 17 750 to 34 175 cm{sup -1}. This set of Gd i lifetimes represents a significant extension to the available published data, with 93 of the 136 level lifetimes measured for the first time. These lifetimes will provide the absolute normalization for a large set of measured Gd i transition probabilities.

  17. Radiative lifetimes of neutral gadolinium

    International Nuclear Information System (INIS)

    The current work is part of an ongoing study of radiative properties of rare earth neutral atoms motivated by research needs in several disparate fields including astrophysics, laser chemistry and lighting technology. Time-resolved laser-induced fluorescence on a slow atomic beam has been used to measure radiative lifetimes, accurate to ±5%, for 136 levels of neutral gadolinium. Of the 136 levels, 6 are odd parity ranging in energy from 32 929 to 36 654 cm-1, and the remaining 130 are even parity ranging from 17 750 to 34 175 cm-1. This set of Gd i lifetimes represents a significant extension to the available published data, with 93 of the 136 level lifetimes measured for the first time. These lifetimes will provide the absolute normalization for a large set of measured Gd i transition probabilities.

  18. Radiative lifetimes of neutral samarium

    International Nuclear Information System (INIS)

    Radiative lifetimes of 120 odd-parity levels of neutral samarium, ranging in energy from 17 190 to 33 507 cm−1, are measured using the technique of time-resolved laser-induced fluorescence on a slow atomic beam. This work is part of an ongoing study of radiative properties of rare earth neutral atoms, and is motivated by research needs in astrophysics and lighting technology. This set of Sm i lifetimes substantially increases the available published lifetime data, with 49 of the 120 level lifetimes measured for the first time. These data, most of which are accurate to ±5%, will be combined with branching fractions determined from Fourier transform spectroscopy to produce a large set of measured Sm i transition probabilities. (paper)

  19. High power neutral beam systems

    International Nuclear Information System (INIS)

    Spurred by the requirement to supply megawatts of power to heat magnetically confined plasmas to temperatures of interest for fusion research, a new class of low energy, high power accelerators termed neutral beam injectors has been developed. Industry has played an important role in building upon technology advances at the national laboratories to engineer neutral beam injectors to meet the needs of specific users. A brief retrospective of the field is presented, with emphasis upon one particular application, that of DIII-D, a large tokamak at General Atomics. In this instance, the role of industry has been especially extensive because the user/system integrator is itself an industrial concern. 4 refs., 7 figs., 2 tabs

  20. Money neutrality: Rethinking the myth

    OpenAIRE

    Issaoui Fakhri; Boufateh Talel; Guesmi Mourad

    2015-01-01

    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...

  1. Optimization of Neutral Atom Imagers

    Science.gov (United States)

    Shappirio, M.; Coplan, M.; Balsamo, E.; Chornay, D.; Collier, M.; Hughes, P.; Keller, J.; Ogilvie, K.; Williams, E.

    2008-01-01

    The interactions between plasma structures and neutral atom populations in interplanetary space can be effectively studied with energetic neutral atom imagers. For neutral atoms with energies less than 1 keV, the most efficient detection method that preserves direction and energy information is conversion to negative ions on surfaces. We have examined a variety of surface materials and conversion geometries in order to identify the factors that determine conversion efficiency. For chemically and physically stable surfaces smoothness is of primary importance while properties such as work function have no obvious correlation to conversion efficiency. For the noble metals, tungsten, silicon, and graphite with comparable smoothness, conversion efficiency varies by a factor of two to three. We have also examined the way in which surface conversion efficiency varies with the angle of incidence of the neutral atom and have found that the highest efficiencies are obtained at angles of incidence greater then 80deg. The conversion efficiency of silicon, tungsten and graphite were examined most closely and the energy dependent variation of conversion efficiency measured over a range of incident angles. We have also developed methods for micromachining silicon in order to reduce the volume to surface area over that of a single flat surface and have been able to reduce volume to surface area ratios by up to a factor of 60. With smooth micro-machined surfaces of the optimum geometry, conversion efficiencies can be increased by an order of magnitude over instruments like LENA on the IMAGE spacecraft without increase the instruments mass or volume.

  2. The Economics of Network Neutrality

    OpenAIRE

    Nicholas Economides; Benjamin Hermalin

    2010-01-01

    Pricing of Internet access has been characterized by two properties. Parties are directly billed only by the Internet Service Provider (ISP) through which they connect to the Internet and the ISP charges them on the basis of the amount of information transmitted rather than its content. These properties define a regime known as “network neutrality.” In 2005, some large ISPs proposed that application and content providers directly pay them additional fees for accessing the ISPs’ residential cl...

  3. Net neutrality and investment incentives

    OpenAIRE

    Choi, Jay Pil; Kim, Byung-Cheol

    2008-01-01

    This paper analyzes the effects of net neutrality regulation on investment incentives for Internet service providers (ISPs) and content providers (CPs), and their implications for social welfare. We show that the ISP's decision on the introduction of discrimination across content depends on a potential trade-off between network access fee and the revenue from the trade of the first-priority. Concerning the ISP's investment incentives, we find that capacity expansion affects the sale price of ...

  4. Neutral and Charged Anyon Fluids

    OpenAIRE

    Hosotani, Yutaka

    1993-01-01

    (Review) Properties of neutral and charged anyon fluids are examined, with the main focus on the question whether or not a charged anyon fluid exhibits a superconductivity at zero and finite temperature. Quantum mechanics of anyon fluids is precisely described by Chern-Simons gauge theory. The random phase approximation (RPA), the linearized self-consistent field method (SCF), and the hydrodynamic approach employed in the early analysis of anyon fluids are all equivalent. Relations and differ...

  5. 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

  6. Efficient Surface Display of Diisopropylfluorophosphatase (DFPase) in E. coli for Biodegradation of Toxic Organophosphorus Compounds (DFP and Cp).

    Science.gov (United States)

    Latifi, Ali Mohammad; Karami, Ali; Khodi, Samaneh

    2015-10-01

    Compounds including organophosphorus pesticides (OPs) and chemical nerve agents are toxic compounds synthesized recently which disrupt the mechanisms of neural transmission. Therefore, a critical requirement is the development of a bio-refining technology to facilitate the biodegradation of organophosphorus pollutants. The diisopropylfluorophosphatase (DFPase, EC 3.1.8.2) from the ganglion and brain of Loligo vulgaris acts on P-F bonds present in some OPs. Intracellular production of OPs-degrading enzymes or the use of native bacteria and fungi leads to a low degradation rate of OPs due to a mass transfer issue which reduces the overall catalytic efficiency. To overcome this challenge, we expressed DFPase on the surface of E. coli for the first time by employing the N-terminal domain of the ice nucleation protein (InaV-N) as an anchoring motif. Tracking the recombinant protein confirmed that DFPase is successfully located on the outer membrane. Further studies on its activity to degrade diisopropylfluorophosphate (DFP) showed its significant ability for the biodegradation of diisopropylfluorophosphate (DFP) with a specific activity of 500 U/mg of wet cell weight. Recombinant cells could also degrade chlorpyrifos (Cp) with an activity equivalent to a maximum value of 381.44 U/ml with a specific activity of 476.75 U/mg of cell, analyzed using HPLC technique. The optimum activity of purified DFPase was found at 30 °C. A more increased activity was also obtained in the presence of glucose-mineral-salt (GMS) supplemented with tryptone and 100 mg/L Co(2+) ion. These results highlight the high potential of the InaV-N anchoring domain to produce an engineered bacterium that can be used in the bioremediation of pesticide-contaminated environments. PMID:26239441

  7. Identification of new binding sites of human transferrin incubated with organophosphorus agents via Q Exactive LC-MS/MS.

    Science.gov (United States)

    Sun, Fengjuan; Ding, Junjie; Yu, Huilan; Gao, Runli; Wang, Hongmei; Pei, Chengxin

    2016-06-01

    Organophosphorus agents (OPs) like sarin, VX, or soman could inhibit acetylcholinesterase activity and cause poisoning. OPs could bind many proteins, such as butyrylcholinesterase and albumin, and the adducts formed could identify the exposure. In this paper, we studied human transferrin, which was one of the proteins that could be labeled by OPs. Pure human transferrin was incubated with an overdose of organophosphorus agents, including sarin, soman, VX, tabun, cyclosarin, ethyl tabun, and propyl tabun, and then additional OPs was removed through dialysis. Trypsin was used to cleave the OP-treated proteins and Q Exactive liquid chromatography tandem mass spectrometry (Q Exactive LC-MS/MS) was used to identify them. The present study set out to accomplish two goals. The first goal was to find a good method for identifying multiple binding sites on a given protein through Q Exactive LC-MS/MS. The second goal was to investigate the labeled peptides when transferrin was incubated with a numerous molar excess of OPs. Results showed that tyrosine, lysine, and serine formed covalent bonds with OPs. Twenty OP-labeled sites were found: ten tyrosine sites (including two reported sites), seven lysine sites, and three serine sites. Characteristic fragments for labeled-tyrosine and labeled-lysine adducts were summarized in detail. In conclusion, the method by Q Exactive LC-MS/MS using in this present work is a good way to diagnose exposure to OPs accurately when the binding sites of OPs are uncertain. Novel modified peptides and the characteristic ions found in this work could help investigators assess exposure to OPs. PMID:27128859

  8. Steady state neutral beam injector

    International Nuclear Information System (INIS)

    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 >105 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/m2, 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)

  9. 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.

  10. Net Neutrality, Business Models, and Internet Interconnection

    OpenAIRE

    Jay Pil Choi; Doh-Shin Jeon; Byung-Cheol Kim

    2015-01-01

    We analyze the effect of net neutrality regulation in a two-sided market framework when content is heterogeneous in its sensitivity to delivery quality. We characterize the equilibrium in a neutral network constrained to offer the same quality vis-à-vis a non neutral network where Internet service providers are allowed to engage in second degree price discrimination with a menu of quality-price pairs. We find that the merit of net neutrality regulation depends crucially on content providers' ...

  11. 46 CFR 502.404 - Neutrals.

    Science.gov (United States)

    2010-10-01

    ... Dispute Resolution § 502.404 Neutrals. (a) A neutral may be a permanent or temporary officer or employee of the Federal Government or any other individual who is acceptable to the parties to a dispute... Maritime Commission Dispute Resolution Specialist will seek to provide a neutral in dispute...

  12. Electroweak Chiral Lagrangian for Neutral Higgs Boson

    Institute of Scientific and Technical Information of China (English)

    WANG Shun-Zhi; WANG Qing

    2008-01-01

    A neutral Higgs boson is added into the traditional electroweak chiral Lagrangian by writing down all possible high dimension operators. The matter part of the Lagrangian is investigated in detail. We find that if Higgs field dependence of Yukawa couplings can be factorized out, there will be no flavour changing neutral couplings; neutral Higgs can induce coupling between light and heavy neutrinos.

  13. 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.

  14. Rapid method for the determination of some organophosphorus insecticides in a small amount of serum in emergency and occupational toxicology cases

    Directory of Open Access Journals (Sweden)

    Singh Bhoopendra

    2009-01-01

    Full Text Available A simple and rapid method is described for the estimation of some organophosphorus insecticides in the serum of occupationally exposed persons. The compounds are extracted with a mixture of acetone and diethyl ether (1:1 v/v in acidic medium and the extraction residue is analyzed by gas chromatography with nitrogen phosphorus detection method. Linearity was acceptable over concentrations from 0.25 to 4.0 µg/mL. The method percentile recovery for the six different organophosphorus insecticides was 86.3% for phorate, 78.3% for dimethoate, 82.3% for malathion, 79.4% for chlorpyrifos, 80.2% for diazinon, and 68.5% for ethion at the µg/mL level. Serum samples of nine workers who had been occupationally exposed to malathion in an insecticide manufacturing factory, were analyzed and malathion was found at low levels in all the samples.

  15. 6种有机磷农药标准溶液不确定度分析%Uncertainty analyse of six organophosphorus pesticides standard solution

    Institute of Scientific and Technical Information of China (English)

    孙晓梅; 刘慈玉

    2011-01-01

    分析了乙酰甲胺磷、乙硫磷、丙线磷、苯硫磷、特丁磷、硫线磷6种有机磷农药标准溶液研制过程中测量不确定度的影响因素,并计算出有机磷标准溶液质量浓度的扩展不确定度.不确定度分量中,配制过程和溶液稳定性的不确定度是主要的.%The influence factors during the measument of uncertainty for the acephate, ethion, ethoprophos, EPN, terbufos, cadusafos 6 organophosphorus pesticides standard solution were analyzed. The expanding uncertainty of organophosphorus pesticides standard solution was calculated. The preparation process and stability of solution were the mainfactors which most affected uncertainty of measurement system.

  16. 微生物降解有机磷农药残留的研究进展%A review on microbial degradation of residues of organophosphorus pesticide

    Institute of Scientific and Technical Information of China (English)

    何霞; 白红娟

    2011-01-01

    This article focused on the review of the types of microbial degradation of Organophosphorus pesticide,degradation mechanism and degradation genes in recent years and discussed development trend of microbial degradation of organophosphorus pesticide,and exhibited some suggestions for further research.%从微生物降解有机磷农药的种类、降解机理、降解基因等方面综述了微生物降解有机磷农药近年来的研究进展,探讨了微生物降解有机磷农药研究领域的发展趋势及进一步的研究方向,并提出建议。

  17. Gas Flow Measurements of a Novel Geometry for Neutral Beam Neutralizers.

    Science.gov (United States)

    Pirkle, David Ross

    The gas flow characteristics of a novel geometry (pumped neutralizer) for decreasing the flow of gas from neutral beam neutralizers were measured and compared with a conventional (passive) neutralizer. A passive neutralizer is typically a duct attached to the ion source. For the pumped neutralizer the top and bottom surfaces of the duct are replaced by a Venetian blind geometry which opens into ballast vacuum pumping volumes. With guidance from a Monte Carlo program which models gas flow at low pressure, a one-half scale model with pumped neutralizer geometry was built and compared to a passive neutralizer with comparable dimensions. With the vanes on the pumped neutralizer opened to 55 degrees, the line density of the pumped neutralizer was 1.6 times less than the passive neutralizer. The amount of gas flowing from the exit of the pumped neutralizer was from 2 to 5 times less than the amount flowing from the pumped neutralizer. Hence, the pumped neutralizer geometry appears to be a promising method of limiting the flow of gas from neutral beam gas cell neutralizers.

  18. RESEARCH ON ENVIRONMENTAL CONTAMINATION IN RAW MILK IN TURIN DEPARTEMENT : HEAVY METALS, P.C.B, ORGANOCHLORINE AND ORGANOPHOSPHORUS PESTICIDES – YEARS 2005 – 2008

    OpenAIRE

    S. Cavallera; M.C. Abete; M. Garrone; R Tarasco; S Gavinelli; B. Vivaldi; S. Chiarelli

    2013-01-01

    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.

  19. Determination of organophosphorus pesticide residues in vegetables by an enzyme inhibition method using α-naphthyl acetate esterase extracted from wheat flour*

    OpenAIRE

    WANG, JUN-LIANG; Xia, Qing; Zhang, An-Ping; Hu, Xiao-Yan; Lin, Chun-mian

    2012-01-01

    The widespread use of organophosphorus pesticides (OPs) poses a great threat to human health and has made the detection of OP residues in food an important task, especially in view of the fact that easy and rapid detection methods are needed. Because OPs have inhibitory effects on the activity of α-naphthyl acetate esterase (ANAE) in plants, in this work we evaluated the possibility of detecting OPs in vegetables with ANAE extracted from commercial flour. The limits of detection (LODs) obtain...

  20. 急性有机磷农药中毒50例治疗分析%Clinical Analysis of 50 Cases of Acute Organophosphorus Pesticide Poisoning

    Institute of Scientific and Technical Information of China (English)

    高喜生

    2014-01-01

    Objective To analyze the clinical characteristics of patients with acute organophosphorus pesticide poisoning,and to give timely and effective treatment measures.Methods In our hospital in 2006~2008 in two years of 50 patients treated in patients with organophosphorus pesticide for analysis.Results To take timely and ef ective after checking measures,50 cases were completely cured,no excessive toxic reaction of atropine and rebound phenomenon of organophosphorus pesticide poisoning.Conclusion Acute organophosphorus pesticide poisoning is the clinical common emergency medicine,early and timely give just the right amount of drug detoxification treatment,treatment is the key to success.%目的探析急性有机磷农药中毒患者的临床表现特点,并给予及时有效的救治措施。方法对我院2006年~2008年2年来收治的50例服入有机磷农药的患者进行分析。结果采取及时有效求治措施后,50例患者均完全治愈,无1例出现阿托品过量的中毒反应及有机磷农药中毒反跳现象。结论急性有机磷农药中毒是临床内科常见的急诊,进行早期及时、给予适量的解毒药物治疗措施,是治疗成功的关键。

  1. ORNL positive ion neutral beam program

    International Nuclear Information System (INIS)

    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

  2. Advanced neutral-beam technology

    International Nuclear Information System (INIS)

    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

  3. 急性有机磷农药中毒患者的急救护理%Emergency nursing care of patients with acute organophosphorus pesticide poisoning

    Institute of Scientific and Technical Information of China (English)

    马鑫

    2014-01-01

    目的:探讨急性有机磷农药中毒患者的急救和护理措施。方法:我院收治35例有机磷农药中毒患者,采取急救措施和护理措施,实施治疗。结果:35例患者在经过精心的救护后,治愈34例,死亡1例。结论:对急性有机磷农药中毒患者,采取一定的急救措施,并给予相应的护理干预,具有较好治疗效果,值得推广。%Objective:To investigate the first aid and nursing measuresof acute organophosphorus pesticide poisoning patients. Methods Patients in our hospital 35 cases of organophosphorus pesticide poisoning, take emergency measures and nursing measures, the implementation of treatment. Results:35 patients after carefultreatment, 34 cases were cured, 1 cases died. Conclusion:Patients with acute organophosphorus pesticide poisoning, take someemergency measures, and give the corresponding nursing intervention, has better curative effect, is worth promoting.

  4. 免疫分析技术在有机磷农药残留检测中应用%Application of immunoassay in organophosphorus pesticide residue analysis

    Institute of Scientific and Technical Information of China (English)

    梁彦

    2013-01-01

    In this review,the harm of organophosphorus pesticide and the commonly used detection methods are introduced,especially that the immunoassay in detection of organophosphorus pesticide residue. The several key factors to affect the immunoassay are reviewed. The main directions of the further development of immunoassay techniques for determining organophosphorus pesticides are also discussed.%  该文简介有机磷农药危害及常用几种检测方法,对免疫分析技术在有机磷农药残留检测中应用进行归纳分析;着重介绍研究最多的酶联免疫分析法,对影响免疫分析方法几个关键因素进行综述,并探讨免疫分析技术在有机磷农药检测领域发展。

  5. Syntheses and solid state structures of zinc (II) complexes with Bi-dentate -(Aryl)imino-acenapthenone (Ar-BIAO) ligands

    Indian Academy of Sciences (India)

    Srinivas Anga; Supriya Rej; Kishor Naktode; Tigmansu Pal; Tarun K Panda

    2015-01-01

    We have synthesized five zinc complexes of molecular formulae [ZnCl2(2,6-dimethylphenyl-BIAO)]2 (1a), [ZnBr2(2,6-dimethylphenyl-BIAO)]2 (1b), [ZnI2(2,6-dimethylphenyl-BIAO)]2(1c), [ZnBr2(mes-BIAO)]2(2b) and [ZnBr2(dipp-BIAO)] (3b) with rigid unsymmetrical iminoacenaphthenone ligands, (2,6-dimethylphenyl-BIAO) (1), (mesityl-BIAO) (2) and (2,6-diisopropylphenyl-BIAO) (3). The zinc complex 1a was prepared by the reaction of ZnCl2 and neutral (mesityl-BIAO) (1). However, complexes 1b, 2b and 3b were obtained by the treatment of ZnBr2 and neutral ligands 1-3 respectively in 1:1 molar ratio in dichloromethane at ambient temperature. In a similar reaction of ZnI2 with (2,6-dimethylphenyl-BIAO) (1) in dichloromethane the corresponding iodo-complex 1c was obtained in good yield. All the zinc (II) complexes are characterized by FT-IR, 1H and 13C{1H} NMR spectroscopic techniques. The solid state structures of the complexes 1a, 1b, 1c, 2b and 3b are confirmed by single crystal X-ray diffraction analysis. The molecular structures of complexes 1a, 1b, 1c and 2b reveal the dimeric nature of the complexes and subsequently the centre atom zinc is penta-coordinated to adopt distorted trigonal bipyramidal geometry around it. In contrast, the complex 3b is in monomeric in nature due to bulkier size of the ligand and zinc ion is tetra coordinated to adopt distorted tetrahedral geometry.

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

    International Nuclear Information System (INIS)

    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.

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

    International Nuclear Information System (INIS)

    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)(H2O)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

  8. 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

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Radiative lifetimes of neutral cerium

    International Nuclear Information System (INIS)

    Radiative lifetimes, accurate to ±5%, have been measured for 153 levels of neutral cerium using time-resolved laser-induced fluorescence (TRLIF) on a slow beam of cerium atoms. Of the 153 levels studied, 150 are even parity and 3 are odd parity. The levels range in energy from 16 869 to 28 557 cm-1. This set of Ce I lifetimes is much more extensive than others published to date, and will provide the absolute calibration for a very large set of measured Ce I transition probabilities. Accurate transition probabilities for lines in the visible and ultraviolet are needed both in astrophysics, for the determination of elemental abundances, and by the lighting community, for research and development of metal halide high-intensity discharge lamps.

  14. Radiative lifetimes of neutral erbium

    Energy Technology Data Exchange (ETDEWEB)

    Den Hartog, E A; Chisholm, J P; Lawler, J E, E-mail: eadenhar@wisc.ed, E-mail: chisholm@astro.wisc.ed, E-mail: jelawler@wisc.ed [Department of Physics, University of Wisconsin, 1150 University Ave., Madison, WI 53706 (United States)

    2010-08-14

    Radiative lifetimes have been measured for 123 levels of neutral erbium using time-resolved laser-induced fluorescence on a slow beam of erbium atoms. Of the 123 levels, 56 are even parity and range in energy from 26 993 to 40 440 cm{sup -1} and 67 are odd parity ranging from 16 070 to 38 401 cm{sup -1}. This set of Er i lifetimes is much more extensive than others published to date, with 90 of the 123 level lifetimes measured for the first time. These lifetimes will provide the absolute calibration for a large set of measured Er i transition probabilities. Spectroscopic studies of rare earth elements including erbium are motivated by research needs in both the astrophysics and lighting communities.

  15. Radiative lifetimes of neutral erbium

    International Nuclear Information System (INIS)

    Radiative lifetimes have been measured for 123 levels of neutral erbium using time-resolved laser-induced fluorescence on a slow beam of erbium atoms. Of the 123 levels, 56 are even parity and range in energy from 26 993 to 40 440 cm-1 and 67 are odd parity ranging from 16 070 to 38 401 cm-1. This set of Er i lifetimes is much more extensive than others published to date, with 90 of the 123 level lifetimes measured for the first time. These lifetimes will provide the absolute calibration for a large set of measured Er i transition probabilities. Spectroscopic studies of rare earth elements including erbium are motivated by research needs in both the astrophysics and lighting communities.

  16. Radiative lifetimes of neutral cerium

    Energy Technology Data Exchange (ETDEWEB)

    Den Hartog, E A; Buettner, K P; Lawler, J E [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States)], E-mail: eadenhar@wisc.edu, E-mail: Kevin.Buettner@usma.edu, E-mail: jelawler@wisc.edu

    2009-04-28

    Radiative lifetimes, accurate to {+-}5%, have been measured for 153 levels of neutral cerium using time-resolved laser-induced fluorescence (TRLIF) on a slow beam of cerium atoms. Of the 153 levels studied, 150 are even parity and 3 are odd parity. The levels range in energy from 16 869 to 28 557 cm{sup -1}. This set of Ce I lifetimes is much more extensive than others published to date, and will provide the absolute calibration for a very large set of measured Ce I transition probabilities. Accurate transition probabilities for lines in the visible and ultraviolet are needed both in astrophysics, for the determination of elemental abundances, and by the lighting community, for research and development of metal halide high-intensity discharge lamps.

  17. Happy birthday, little neutral one

    International Nuclear Information System (INIS)

    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)

  18. After treatment ends: neutral time.

    Science.gov (United States)

    Hurt, G J; McQuellon, R P; Barrett, R J

    1994-01-01

    For persons diagnosed with cancer, the remission period may be marked by increased anxiety and distress. While the medical team may view remission as an eagerly anticipated milestone, the decreased medical surveillance during this time can cause a heightened fear of recurrence for the patient. One author has called this period of remission "neutral time," a time characterized by uncertainty. The safety signal hypothesis, developed by Martin Seligman, may help to explain the anxiety experienced by some patients during the remission period. Because cancer is frequently a silent disease with no overt symptoms, patients in remission often have no safety signal to indicate that the disease will not return. A case study is presented and discussed in light of these two concepts. PMID:7697080

  19. 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)

    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)

  20. 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)

    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 CD50 value of 2.5 /μg/ml. (author)

  1. 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)

    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)2Cl2], in particular, was found to be active against all the fungi tested. The complexes were however inactive against leukemic cell lines (CEM-SS). (author)

  2. Tenure neutral and equitable housing taxation

    OpenAIRE

    Thalmann, Philippe

    2007-01-01

    Equity and neutrality are distinct concepts in housing taxation and weak and strong tenure neutrality should be distinguished. When a tax system is tested for those criteria, the taxes paid by landlords must be included, as they affect the rents renters pay. This paper defines appropriate tests, applies them to a stylised tax system and proposes tax changes designed to restore tenure equity and/or neutrality. It shows how the homeowner's implicit income should be computed for taxes to be fund...

  3. Irish neutrality and the Lisbon Treaty

    OpenAIRE

    Devine, Karen

    2009-01-01

    One of the main themes of the conference focused on the definition of neutrality. The convenors of the conference frequently raised the question, “what do we mean when we talk of ‘neutrality’?” This paper explains the differences between the public concept of neutrality and government concepts of ‘military neutrality’ and evaluates whether the Lisbon Treaty, including the June 2009 ‘clarification’ declarations, contravene or protect neutrality.

  4. Evaluating Neutrality Properties of Corporate Tax Reforms

    OpenAIRE

    Michael P. Devereux; Simon Loretz

    2010-01-01

    We propose a methodology for assessing the neutrality of corporate tax reform proposals in an open economy. The methodology identifies variation in effective tax rates to assess the proximity of a tax system to capital export neutrality (CEN) and to market neutrality (MN, which holds if all potential competitors in a single market face the same effective tax rate). We apply the methodology to two reform options in the EU. Optional international loss consolidation would move the EU tax system ...

  5. The Research Progress of Degradation Method for Organophosphorus Pesticide Residues from Vegetables%蔬菜中有机磷农药残留降解方法的研究进展

    Institute of Scientific and Technical Information of China (English)

    何迪; 李明浩; 李晓东

    2012-01-01

    At present,organophosphorus pesticide is one of the most widely used chemical pesticides and mainly applied in vegetables. Organophosphorus pesticide residues brought serious threat to human health. Degradation methods for organophosphorus pesticide residues mainly include physical degradation,chemical degradation and biodegradation,during which biodegradation has the most widely application prospect.%目前有机磷农药是应用最为广泛的化学农药之一,蔬菜是其主要作用对象,有机磷农药带来的药残严重威胁人类的健康.对于有机磷药残的降解方法主要有物理降解、化学降解和生物降解,其中生物降解法是应用前景最为广泛的降解方法之一.

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

    Science.gov (United States)

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

    2013-06-01

    A sorbent material based on silica particles modified with poly(N-vinylimidazole) (SiO2-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 24 was used for selection of extraction conditions. The factors were contact time, acetone volume, treatment (with or without freeze-drying) and adsorbent (SiO2 or SiO2-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 SiO2-PVI in spiked tomato with 0.2 and 0.8μg/g.

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

    International Nuclear Information System (INIS)

    A sorbent material based on silica particles modified with poly(N-vinylimidazole) (SiO2-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 24 was used for selection of extraction conditions. The factors were contact time, acetone volume, treatment (with or without freeze-drying) and adsorbent (SiO2 or SiO2-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 SiO2-PVI in spiked tomato with 0.2 and 0.8μg/g.

  8. 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.

  9. Organophosphorus flame retardants and plasticizers in the aquatic environment: A case study of the Elbe River, Germany.

    Science.gov (United States)

    Wolschke, Hendrik; Sühring, Roxana; Xie, Zhiyong; Ebinghaus, Ralf

    2015-11-01

    This study reports the occurrence and distribution of organophosphorus flame retardants and plasticizers (OPEs) in the Elbe and Rhine rivers. A special focus of this investigation concerns the potential impacts of a major flood event in 2013 on the OPE patterns and levels in the Elbe River. In this river, 6 of 13 OPEs were detected, with tris-ethyl-phosphate (TEP, 168 ± 44 ng/L), tris-1,3-dichloro-2-propyl-phosphate (TDCPP, 155 ± 14 ng/L) and tris-1-chloro-2-propyl phosphate (TCPP, 126 ± 14 ng/L) identified as the dominant compounds. Relative to previous studies, an increase in the concentrations and relative contributions of TDCPP to the total level of OPEs was observed, which was likely caused by its increased use as a replacement for the technical pentaBDE formulation. During the flood event, the concentrations of OPEs were similar to the normal situation, but the mass fluxes increased by a factor of approximately ten (∼16 kg/d normal versus ∼160 kg/d flood peak). No input hotspots were identified along the transects of the Elbe and Rhine rivers, and the mass flux of OPEs appeared to be driven by water discharge. PMID:26284344

  10. 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. PMID:24813984

  11. Genome-wide gene expression analysis in response to organophosphorus pesticide chlorpyrifos and diazinon in C. elegans.

    Directory of Open Access Journals (Sweden)

    Ana Viñuela

    Full Text Available Organophosphorus pesticides (OPs were originally designed to affect the nervous system by inhibiting the enzyme acetylcholinesterase, an important regulator of the neurotransmitter acetylcholine. Over the past years evidence is mounting that these compounds affect many other processes. Little is known, however, about gene expression responses against OPs in the nematode Caenorhabditis elegans. This is surprising because C. elegans is extensively used as a model species in toxicity studies. To address this question we performed a microarray study in C. elegans which was exposed for 72 hrs to two widely used Ops, chlorpyrifos and diazinon, and a low dose mixture of these two compounds. Our analysis revealed transcriptional responses related to detoxification, stress, innate immunity, and transport and metabolism of lipids in all treatments. We found that for both compounds as well as in the mixture, these processes were regulated by different gene transcripts. Our results illustrate intense, and unexpected crosstalk between gene pathways in response to chlorpyrifos and diazinon in C. elegans.

  12. In vivo tracing of organochloride and organophosphorus pesticides in different organs of hydroponically grown malabar spinach (Basella alba L.).

    Science.gov (United States)

    Qiu, Junlang; Chen, Guosheng; Xu, Jianqiao; Luo, Erlun; Liu, Yan; Wang, Fuxin; Zhou, Hong; Liu, Yuan; Zhu, Fang; Ouyang, Gangfeng

    2016-10-01

    An in vivo uptake and elimination tracing study based on solid phase microextraction (SPME) was conducted to investigate the accumulation, persistence and distribution of organochloride pesticides (OCPs) and organophosphorus pesticides (OPPs) in malabar spinach (Basella alba L.) plants. Uptake and elimination of the pesticides were traced in leaves, stems and roots of living malabar spinach plants. Root concentration factor (RCF), distribution concentration factor (DCF) and transpiration stream concentration factor (TSCF) were calculated based on the in vivo tracing data. The tracing data showed that the OCPs were much more accumulative and persistent than the OPPs in roots, while they were similarly accumulative and persistent in leaves and stems. RCF values of the OPPs or OCPs were likely to increase with the increase in LogKow values except fenthion. Obtained DCF values indicated that OPPs and OCPs were more accumulative in the organs containing more lipids. TSCF values showed that the translocation of OPPs and OCPs from roots to foliage was firstly dependent on the hydrophobicity of the compounds, but also significantly affected by the water solubility. This is the first study of generating RCF, DCF and TSCF data in living plants by in vivo sampling method, which provides a foundation to promote the application of in vivo SPME and improve understanding of contaminant behaviors in living plants. PMID:27209519

  13. A study on oxidative stress and antioxidant status of agricultural workers exposed to organophosphorus insecticides during spraying

    Directory of Open Access Journals (Sweden)

    Rastogi S

    2009-01-01

    Full Text Available Oxidative stress status and Acetylcholinesterase (AChE activity were studied in blood samples obtained from 61 agricultural workers engaged in spraying organophosphorus (OP insecticides in the mango plantation, with a minimum work history of one year, in the age range of 12-55 years. Controls were age-matched, unexposed workers, who never had any exposure to OP pesticides. They were evaluated for oxidative stress markers MDA (end product of lipid peroxidation, reduced glutathione (GSH, and Acetylcholinesterase (AChE and butyrylcholinesterase (BChE levels in blood. The results showed a marked inhibition of the AChE and BChE activities in the sprayers as compared to the controls. The malondialdehyde(MDA, the last product of lipid peroxidation was found to be increased significantly in sprayers(p< 0.05, while depletion in the concentration of antioxidant glutathione(GSH was also observed in the sprayers but the difference was statistically not significant. It was concluded on the basis of biochemical analysis that pesticides sprayers are exposed to more oxidative stress as evidenced by the changes in antioxidant status. The measurement of the AChE and BChE activities in agricultural workers who spray OPs could be a good biomonitoring factor and is recommended to be performed on a regular basis.

  14. 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.

  15. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Jing; Hou, Juying; Jiang, Jianxia; Ai, Shiyun, E-mail: ashy@sdau.edu.cn

    2015-07-23

    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{sup −11} M to 5.0 × 10{sup −7} M with a detection limit of 6.8 × 10{sup −12} M (S/N = 3). Moreover, the favorable detection performance in water and soil samples heralded the promising applications in on-site OPs detection.

  17. 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

  18. Mechanistic insights into the luminescent sensing of organophosphorus chemical warfare agents and simulants using trivalent lanthanide complexes.

    Science.gov (United States)

    Dennison, Genevieve H; Johnston, Martin R

    2015-04-20

    Organophosphorus chemical warfare agents (OP CWAs) are potent acetylcholinesterase inhibitors that can cause incapacitation and death within minutes of exposure, and furthermore are largely undetectable by the human senses. Fast, efficient, sensitive and selective detection of these compounds is therefore critical to minimise exposure. Traditional molecular-based sensing approaches have exploited the chemical reactivity of the OP CWAs, whereas more recently supramolecular-based approaches using non-covalent interactions have gained momentum. This is due, in part, to the potential development of sensors with second-generation properties, such as reversibility and multifunction capabilities. Supramolecular sensors also offer opportunities for incorporation of metal ions allowing for the exploitation of their unique properties. In particular, trivalent lanthanide ions are being increasingly used in the OP CWA sensing event and their use in supramolecular sensors is discussed in this Minireview. We focus on the fundamental interactions of simple lanthanide systems with OP CWAs and simulants, along with the development of more elaborate and complex systems including those containing nanotubes, polymers and gold nanoparticles. Whilst literature investigations into lanthanide-based OP CWA detection systems are relatively scarce, their unique and versatile properties provide a promising platform for the development of more efficient and complex sensing systems into the future. PMID:25649522

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

    International Nuclear Information System (INIS)

    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

  20. Efficient laser production of energetic neutral beams

    Science.gov (United States)

    Mollica, F.; Antonelli, L.; Flacco, A.; Braenzel, J.; Vauzour, B.; Folpini, G.; Birindelli, G.; Schnuerer, M.; Batani, D.; Malka, V.

    2016-03-01

    Laser-driven ion acceleration by intense, ultra-short, laser pulse has received increasing attention in recent years, and the availability of much compact and versatile ions sources motivates the study of laser-driven sources of energetic neutral atoms. We demonstrate the production of a neutral and directional beam of hydrogen and carbon atoms up to 200 keV per nucleon, with a peak flow of 2.7× {{10}13} atom s-1. Laser accelerated ions are neutralized in a pulsed, supersonic argon jet with tunable density between 1.5× {{10}17} cm-3and 6× {{10}18} cm-3. The neutralization efficiency has been measured by a time-of-flight detector for different argon densities. An optimum is found, for which complete neutralization occurs. The neutralization rate can be explained only at high areal densities (>1× {{10}17} cm-2) by single electron charge transfer processes. These results suggest a new perspective for the study of neutral production by laser and open discussion of neutralization at a lower density.

  1. On the possible eigenoscillations of neutral sheets

    International Nuclear Information System (INIS)

    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

  2. Transportation Cost Inequalities for Neutral Functional SDEs

    OpenAIRE

    Bao, Jianhai; Yuan, Chenggui

    2012-01-01

    A class of functional differential equations are investigated. Using the Girsanov-transformation argument we establish the quadratic transportation cost inequalities for a class of finite-dimensional neutral functional stochastic differential equations and infinite-dimensional neutral functional stochastic partial differential equations under different metrics.

  3. 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...

  4. "Unconventional" Neutralizing Activity of Antibodies Against HIV

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Neutralizing antibodies are recognized to be one of the essential elements of the adaptive immune response that must be induced by an effective vaccine against HIV. However, only a limited number of antibodies have been identified to neutralize a broad range of primary isolates of HIV-1 and attempts to induce such antibodies by immunization were unsuccessful. The difficulties to generate such antibodies are mainly due to intrinsic properties of HIV-1 envelope spikes, such as high sequence diversity, heavy glycosylation, and inducible and transient nature of certain epitopes. In vitro neutralizing antibodies are identified using "conventional" neutralization assay which uses phytohemagglutinin (PHA)-stimulated human PBMCs as target cells. Thus, in essence the assay evaluates HIV-1 replication in CD4+ T cells. Recently, several laboratories including us demonstrated that some monoclonal antibodies and HIV-1-specific polyclonal IgG purified from patient sera, although they do not have neutralizing activity when tested by the "conventional" neutralization assay, do exhibit potent and broad neutralizing activity in "unconventional" ways. The neutralizing activity of these antibodies and IgG fractions is acquired through post-translational modifications, through opsonization of virus particles into macrophages and immature dendritic cells (iDCs), or through expression of antibodies on the surface of HIV-1-susceptible cells. This review will focus on recent findings of this area and point out their potential applications in the development of preventive strategies against HIV.

  5. Neutralizing antibodies in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Mirjam B Zeisel; Samira Fafi-Kremer; Isabel Fofana; Heidi Barth; Fran(c)oise Stoll-Keller; Michel Doffo(e)l; Thomas F Baumert

    2007-01-01

    Hepatitis C virus (HCV) is a major cause of hepatitis world-wide. The majority of infected individuals develop chronic hepatitis which can then progress to liver cirrhosis and hepatocellular carcinoma. Spontaneous viral clearance occurs in about 20%-30% of acutely infected individuals and results in resolution of infection without sequaelae. Both viral and host factors appear to play an important role for resolution of acute infection. A large body of evidence suggests that a strong, multispecific and long-lasting cellular immune response appears to be important for control of viral infection in acute hepatitis C. Due too the lack of convenient neutralization assays,the impact of neutralizing responses for control of viral infection had been less defined. In recent years, the development of robust tissue culture model systems for HCV entry and infection has finally allowed study of antibody-mediated neutralization and to gain further insights into viral targets of host neutralizing responses.In addition, detailed analysis of antibody-mediated neutralization in individual patients as well as cohorts with well defined viral isolates has enabled the study of neutralizing responses in the course of HCV infection and characterization of the impact of neutralizing antibodies for control of viral infection. This review will summarize recent progress in the understanding of the molecular mechanisms of antibody-mediated neutralization and its impact for HCV pathogenesis.(C) 2007 The WJG Press. All rights reserved.

  6. Spontaneous CP violation and neutral flavour conservation

    International Nuclear Information System (INIS)

    The conditions for one-loop stability of neutral flavour conservation in SU(2)LxU(1) models with spontaneous CP violation are analysed. In addition to previously known cases there is an essentially unique two-generation model with two Higgs doublets where neutral flavour conservation is guaranteed to all orders by a non-standard CP symmetry. (orig.)

  7. Neutralization of low energy broad ion beam

    International Nuclear Information System (INIS)

    The paper is devoted to experimental and theoretical investigation of a low energy broad ion beam space charge and current compensation and ion-beam plasma (IBP), which would be created in transport space of the beam. The beam had cylindrical symmetry. The continuous uniform and hole tube like ion beams are used in the experiments. Different channels of electron appearing have been investigated for cases of neutralization due to secondary γ-electrons from the target and by electrons from glow cathode-neutralizer with metal or dielectric target. Results of neutralizing electrons energy distributions function measurements are presented as well as dependences of electron temperature and self-consisted plasma potential vs. beam parameters, ambient gas pressure, neutralizer parameters. Role of the thermoelectrons and dependence of IBP parameters on neutralizer area, location and potential are discussed. Significant role in neutralization of spatial collisional processes has been revealed even in neutralization by thermocathode. On the base of the experimental results self-consistent theoretical model have been developed, which describes the behavior of intense ion beam passing through the neutral gas at low pressure within conductive walls. The collisionless approach is used which means absence of collisional relaxation of the beam. This theory is used to derive the plasma potential and electron temperature within the beam

  8. A quantum eraser for neutral kaons

    International Nuclear Information System (INIS)

    Full text: Entangled neutral kaon pairs are shown to be very appropriate to discuss extensions and tests of Bohr's complementarity principle through quantum marking and erasure techniques. Neutral kaons cover in a unified way not only a lot of different quantum erasure concepts of already performed experiments, moreover, they offer a new possibility through their decay property. (author)

  9. On plasma-neutral gas interaction

    International Nuclear Information System (INIS)

    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 1017-1021m-3. (auth.)

  10. Measuring the Evolvability Landscape to study Neutrality

    CERN Document Server

    Verel, Sébastien; Clergue, Manuel

    2007-01-01

    This theoretical work defines the measure of autocorrelation of evolvability in the context of neutral fitness landscape. This measure has been studied on the classical MAX-SAT problem. This work highlight a new characteristic of neutral fitness landscapes which allows to design new adapted metaheuristic.

  11. A new sampling formula for neutral biodiversity

    NARCIS (Netherlands)

    Etienne, R.S.

    2005-01-01

    The neutral model of biodiversity, proposed by Hubbell (The Unified Neutral Theory of Biodiversity and Biogeography, Princeton University Press, Princeton, NJ, 2001) to explain the diversity of functionally equivalent species, has been subject of hot debate in community ecology. Whereas Hubbell stud

  12. Geometrically focused neutral beam accelerators

    International Nuclear Information System (INIS)

    A more reliable 40 kV, 65 A power supply drain at 0.4 A/cm2, neutral-beam accelerator was developed for the Tandem Mirror Experiment (TMX). Multiple slotted aperture grids of 60% transparency are fabricated from refractory metal wires mounted to form a spherical surface. This geometrically focuses the beam by aiming individual beamlets at the center of curvature of the spherical grid (r = 3.2 m). We attain greater reliability and faster conditioning with geometrical focusing than with the previous technique of electrostatically steering beamlets to a common point. Electrostatic steering, accomplished by offsetting grid wires, is satisfactory if the offset of a beamlet is much less than the distance from the beamlet to the grids. It was found that Pierce Angle entrance grids performed better if sharper edged. A redesigned accelerator grid support structure reduced the number of ceramic-to-metal vacuum joints, and eliminated O rings between precisely aligned parts. The suppressor grid feedthrough is required to withstand a maximum voltage of 15 kV occurring during breakdown, greatly exceeding the operating voltage of 1.5 kV. Convenient fabrication and assembly techniques have been developed. Assembly of accelerators and plasma sources in a clean room appears to reduce the conditioning time. Following the successful testing of the prototype, eight 40 kV accelerators were built for TMX. Furthermore, ten 20 kV versions were built that are modifiable to 40 kV by exchanging the entrance grid

  13. A 1,2,3-dithiazolyl-o-naphthoquinone: a neutral radical with isolable cation and anion oxidation states.

    Science.gov (United States)

    Smithson, Chad S; MacDonald, Daniel J; Matt Letvenuk, T; Carello, Christian E; Jennings, Michael; Lough, Alan J; Britten, James; Decken, Andreas; Preuss, Kathryn E

    2016-06-21

    Under aprotic conditions, the reaction of 4-amino-1,2-naphthoquinone with excess S2Cl2 generates 4,5-dioxo-naphtho[1,2-d][1,2,3]dithiazol-2-ium chloride in a typical Herz condensation. By contrast, prior literature reports an imine (NH) product, 4,5-dioxo-1H-naphtho[1,2-d][1,2,3]dithiazole, for the same reaction performed in acetic acid. Herein, the cation product is isolated with four different counter-anions (Cl(-), GaCl4(-), FeCl4(-) and OTf(-)). Reduction of the cation generates a neutral radical 1,2,3-dithiazolyl-o-naphthoquinone, with potential ligand properties. Further reduction generates a closed shell anion, isolated as a water-stable Li(+) complex and exhibiting O,O-bidentate chelation. The hydroxy (OH) isomer of the original imine (NH) product is reported, and this can be readily deprotonated and acylated (OAc). All species are structurally characterized. Solution redox behaviour and EPR are discussed where appropriate. PMID:27216412

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

    International Nuclear Information System (INIS)

    This research thesis reports the use of a system made of the LiNO3-KNO3 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

  15. STUDY ON 52 PATIENTS WITH ACUTE SEVERE ORGANOPHOSPHORUS PESTICIDE POISONING%急性重度有机磷中毒52例临床研究

    Institute of Scientific and Technical Information of China (English)

    孟瑞; 卢敏

    2011-01-01

    Objective To evaluate the clinical application of hemoperfusion combined with hemodialysis and continuous micropump infusion of atropine in the treatment of acute severe organophosphorus pesticide poisoning( ASOPP ). Methods A total of 104 patients with ASOPP were retrospectively analysed, all patients were treated with gastric lavage and so on, the treated group adopted hemoperfusion combined with hemodialysis and continuous micropump infusion of atropine in addition to basic therapy. The clinical data was compared. Results The treated group was superior to the control group in time from coma to consciousness, total amount of atropine and recovery time of cholinesterase etc. The recovery rate was 84.6%. Conclusion It is effective to apply hemoperfusion combined with hemodialysis and continuous micropump iffusion of atropine in rescuing the acute severe organophosphorus pesticide poisoning.%目的 评价血液灌流联合血液透析、阿托品微量泵持续泵入治疗急性重度有机磷中毒(acute severe organophosphorus pesticide poisoning,ASOPP)的临床应用价值.方法 对104例ASOPP患者进行回顾性分析,所有患者均给予洗胃等治疗,治疗组在对照组基础上加用血液灌流联合血液透析、阿托品微量泵治疗,比较2组各项临床资料.结果 治疗组昏迷至清醒时间、阿托品总量、胆碱酯酶恢复时间等明显优于对照组,治愈率为84.6%.结论 应用血液灌流联合血液透析、阿托品微量泵治疗ASOPP效果较好.

  16. Tests for complete breakdown of discrete symmetry in D neutral-anti D neutral

    International Nuclear Information System (INIS)

    Implications of the conservation of probability without assuming CPT invariance, but allowing for the existence of a direct superweak (δC=2) interaction are studied for the charmed system D neutral-anti D neutral. We find that the values of the decay widths of the particles with definite mass lead to considerable simplifications in the phenomenological description of this neutral system. These simplifications do not occur in the K neutral-anti K neutral system. In particular, we obtain the expressions for the particle number per unit time, at time tau measured in the D neutral meson rest frame, arising from an initially pure beam of D neutral-mesons. By considering the anomalous part of the particle number expression, we find means of distinguishing between the various forms of discrete symmetry breakdown. (author)

  17. Enantiomeric separation of organophosphorus pesticides by capillary electrophoresis. Application to the determination of malathion in water samples after preconcentration by off-line solid-phase extraction

    OpenAIRE

    García Ruiz, Carmen; Álvarez Llamas, Gloria; Puerta, Ángel; Blanco, Elisa; Sanz Medel, Alfredo; Marina Alegre, María Luisa

    2005-01-01

    The separation of the enantiomers of a group of organophosphorus pesticides (OPs) has been investigated by electrokinetic chromatography (EKC) using different anionic cyclodextrins as chiral selectors. The use of a 25 mM Tris buffer (pH 7.0), 20 mM in CM-β-CD together with an applied voltage of 24 kV and a temperature of 25 °C enabled the individual enantiomeric separation of malathion and phenthoate each one into its two enantiomers, the partial separation of the enantiomers of phenamiphos a...

  18. 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)

    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.

  19. Purification of Sulphate Leach Liquor of Spent Raneynickel Catalyst Containing Al and Ni by Solvent Extraction with Organophosphorus-Based Extractants

    OpenAIRE

    Satunuri Venkateswar Rao; Dong Hyo Yang; Jeong Soo Sohn; Soo-Kyung Kim

    2012-01-01

    Solvent extraction (SX) separation of Al from Ni sulphate leach liquor (LL) of spent Raneynickel catalyst containing 0.12 M Al and 1.448 M Ni using organophosphorus extractants has been investigated. Optimization of process conditions includes aqueous pH, extractant concentration, phase ratio, and stripping. Comparison of Al extraction efficiency with 0.45 M extractant concentration for TOPS 99, PC 88 A, and Cyanex 272 at an equilibrium pH of 2.23 was 81.8%, 98.6%, and 75%, respectively. The ...

  20. Extraction of rare earth elements from their oxides using organophosphorus reagent complexes with HNO_3 and H_2O in supercritical CO_2

    Institute of Scientific and Technical Information of China (English)

    段五华; 曹丕佳; 朱永(贝睿)

    2010-01-01

    Direct extraction of metals from solids with complexing agents in supercritical CO2(SC-CO2) has recently attracted interests in separation,purification,recovery,and analysis of metals.In the present study,the static/dynamic extraction of rare earth elements(Nd,Ce) from their oxides(Nd2O3,CeO2) with organophosphorus complexes with HNO3 and H2O in SC-CO2 was investigated.The static extraction efficiency of Nd from Nd2O3 with the tri-n-butylphosphate(TBP)-HNO3 complex could reach 95% under optimized experiment...

  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. Rare decays of neutral π and eta

    International Nuclear Information System (INIS)

    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

  3. Neutral Supersymmetric Higgs Boson Searches

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Stephen Luke; /Imperial Coll., London

    2009-09-01

    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

  4. 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

  5. A set of triple-resonance nuclear magnetic resonance experiments for structural characterization of organophosphorus compounds in mixture samples

    International Nuclear Information System (INIS)

    Highlights: ► New 1H, 13C, 31P triple-resonance NMR pulse experiments. ► Analysis of organophosphorus (OP) compounds in complex matrix. ► Selective extraction of 1H, 31P, and 13C chemical shifts and connectivities. ► More precise NMR identification of OP nerve agents and their degradation products. - Abstract: The 1H, 13C correlation NMR spectroscopy utilizes JCH 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 1H, 13C 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 1H, 13C, 31P 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 JHP, JCH and JPC 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 products of nerve agents sarin, soman, and VX. The viability of the approach in verification analysis is demonstrated in the analysis of the 30th OPCW Proficiency Test sample.

  6. Sorption and degradation of chlorophenols, nitrophenols and organophosphorus pesticides in the subsoil under landfills — laboratory studies

    Science.gov (United States)

    Kjeldsen, Peter; Kjølholt, Jesper; Schultz, Birgit; Christensen, Thomas H.; Tjell, Jens Christian

    1990-09-01

    Landfills and old industrial plant sites have been identified in an increasing number of cases as point sources of groundwater pollution, dissipating a wide range of industrial chemicals and pesticides. To study the fate of co-disposed chemicals in the subsoil of landfills, anaerobic soil columns loaded with anaerobic leachate from a municipal landfill were set up. The leachate was spiked with eleven compounds representing three groups of chemicals: chlorophenols, nitrophenols and organophosphates. Two subsoils were used in the study. The columns were maintained at Danish groundwater temperature (8-10°C), and were run for a period of 10 months. Analysis of the influent leachate concentrations of the spiked compounds showed that the concentrations were constant during the entire experimental period. Many of the compounds showed delayed breakthrough (compared to chloride breakthrough) in both soils, followed by a constant effluent concentration ratio of less than unity indicating that degradation was occuring. The velocities for the chloro- and nitrophenols were in the range of 10-100% of the water velocity in the two subsoils. The distribution coefficient for the specific phenol, the acidity and the pH of the soil apparently governed the retardation of the phenolic compounds. Degradation of most of the phenols was observed with half-like values of 30-150 days. The four organophosphorus pesticides, Dimethoate ®, Malathion ®, Sulfotep ® and Fenitrothion ®, showed relative velocities from < 10% to ≈ 100%. Malathion ® and Sulfotep ® were degraded with half-life values of 10-20 days, while Dimethoate ® was not significantly degraded in the two soil columns. Fenitrothion ® did not appear in the effluent from the columns within the experimental period of time, probably due to high retardation.

  7. 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.

  8. 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.

  9. 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. PMID:27208478

  10. 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.

  11. Crystal structures of human group-VIIA phospholipase A2 inhibited by organophosphorus nerve agents exhibit non-aged complexes

    Energy Technology Data Exchange (ETDEWEB)

    Samanta, Uttamkumar; Kirby, Stephen D.; Srinivasan, Prabhavathi; Cerasoli, Douglas M.; Bahnson, Brian J.; (Delaware); (USAMRIID)

    2009-09-02

    The enzyme group-VIIA phospholipase A2 (gVIIA-PLA2) is bound to lipoproteins in human blood and hydrolyzes the ester bond at the sn-2 position of phospholipid substrates with a short sn-2 chain. The enzyme belongs to a serine hydrolase superfamily of enzymes, which react with organophosphorus (OP) nerve agents. OPs ultimately exert their toxicity by inhibiting human acetycholinesterase at nerve synapses, but may additionally have detrimental effects through inhibition of other serine hydrolases. We have solved the crystal structures of gVIIA-PLA2 following inhibition with the OPs diisopropylfluorophosphate, sarin, soman and tabun. The sarin and soman complexes displayed a racemic mix of P{sub R} and P{sub S} stereoisomers at the P-chiral center. The tabun complex displayed only the P{sub R} stereoisomer in the crystal. In all cases, the crystal structures contained intact OP adducts that had not aged. Aging refers to a secondary process OP complexes can go through, which dealkylates the nerve agent adduct and results in a form that is highly resistant to either spontaneous or oxime-mediated reactivation. Non-aged OP complexes of the enzyme were corroborated by trypsin digest and matrix-assisted laser desorption ionization mass spectrometry of OP-enzyme complexes. The lack of stereoselectivity of sarin reaction was confirmed by gas chromatography/mass spectrometry using a chiral column to separate and quantitate the unbound stereoisomers of sarin following incubation with enzyme. The structural details and characterization of nascent reactivity of several toxic nerve agents is discussed with a long-term goal of developing gVIIA-PLA2 as a catalytic bioscavenger of OP nerve agents.

  12. Predictors of morbidity and mortality in organophosphorus poisoning: A case study in rural hospital in Karnataka, India

    Directory of Open Access Journals (Sweden)

    Tanveer Hassan Banday

    2015-01-01

    Full Text Available Background: Organophosphorus (OP pesticides poisoning can result from occupational, accidental or intentional exposure. Clinical manifestations include cholinergic syndromes, central nervous (CNS system and cardiovascular disorders. Death is usually due to cardiovascular and respiratory failure. Aim: To evaluate various parameters that can predict outcome of patients in OP poisoning. Materials and Methods: A prospective study conducted in Department of Medicine, Adichunchingiri Institute Of medical Sciences and Research Centre, Karnataka, over period of 1 year. Diagnosis of OP poisoning was based on clinical history of exposure to OP compound and low serum pseudocholinesterase levels. Results: In the present study 133 patients were enrolled, out of which 98.5% were suicidal cases and only 1.5% had accidental exposure. Majority of cases were young male, with F/M ratio 1:3.2. Mortality rates were higher in younger people and in patients who required prolonged ventilator support. The mortality rate was directly proportional to amount of poison consumed, lag time, organ failure (Acute Renal Failure and plasma pseudocholinesterase levels. Acute complications were frequently noted and were related to morbidity and mortality. No strict relationship was found between liver dysfunction, electrolyte disturbance and clinical outcome. Conclusion: This case study concluded that mortality is directly proportionate to the lag time, amount of OP substances consumed, clinical severity, pseudocholinesterase levels, Acute renal failure and duration of ventilatory support. This study highlights the importance of rapid diagnosis, and initiation of early and effective treatment, which may result in less number complications and also decreases the mortality rates.

  13. Organophosphorus insecticides chlorpyrifos and diazinon and oxidative stress in neuronal cells in a genetic model of glutathione deficiency

    International Nuclear Information System (INIS)

    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

  14. Monoacylglycerol lipase inhibition by organophosphorus compounds leads to elevation of brain 2-arachidonoylglycerol and the associated hypomotility in mice

    International Nuclear Information System (INIS)

    Three components of the cannabinoid system are sensitive to selected organophosphorus (OP) compounds: monoacylglycerol (MAG) lipase that hydrolyzes the major endogenous agonist 2-arachidonoylglycerol (2-AG); fatty acid amide hydrolase (FAAH) that cleaves the agonist anandamide present in smaller amounts; the CB1 receptor itself. This investigation considers which component of the cannabinoid system is the most likely contributor to OP-induced hypomotility in mice. Structure-activity studies by our laboratory and others rule against major involvement of a direct toxicant-CB1 receptor interaction for selected OPs. Attention was therefore focused on the OP sensitivities of MAG lipase and FAAH, assaying 19 structurally diverse OP chemicals (pesticides, their metabolites and designer compounds) for in vitro inhibition of both enzymes. Remarkably high potency and low selectivity is observed with three O-alkyl (C1, C2, C3) alkylphosphonofluoridates (C8, C12) (IC50 0.60-3.0 nM), five S-alkyl (C5, C7, C9) and alkyl (C1, C12) benzodioxaphosphorin oxides (IC50 0.15-5.7 nM) and one OP insecticide metabolite (chlorpyrifos oxon, IC50 34-40 nM). In ip-treated mice, the OPs at 1-30 mg/kg more potently inhibit brain FAAH than MAG lipase, but FAAH inhibition is not correlated with hypomotility. However, the alkylphosphonofluoridate-treated mice show dose-dependent increases in severity of hypomotility, inhibition of MAG lipase activity and elevation of 2-AG. Moderate to severe hypomotility is accompanied by 64 to 86% MAG lipase inhibition and about 6-fold elevation of brain 2-AG level. It therefore appears that OP-induced MAG lipase inhibition leads to elevated 2-AG and the associated hypomotility

  15. 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

    2016-03-01

    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. PMID:26964527

  16. Lysophosphatidylcholine hydrolases of human erythrocytes, lymphocytes, and brain: Sensitive targets of conserved specificity for organophosphorus delayed neurotoxicants

    International Nuclear Information System (INIS)

    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 IC50 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

  17. Resistance to organophosphorus agent toxicity in transgenic mice expressing the G117H mutant of human butyrylcholinesterase

    International Nuclear Information System (INIS)

    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

  18. Neutral gas heating in helium microplasmas

    Science.gov (United States)

    Jugroot, M.

    2009-01-01

    The present study details a self-consistent model of charged and neutral particle dynamics which is applied to atmospheric small-space (200 μm) discharges in helium. Hydrodynamic transport equations of the self-consistent and time-dependant model are described with an emphasis on the different terms involved in the close coupling among charged species, neutral species, and the electric field. Those equations are solved by two-dimensional numerical schemes for both species transport and electric field. The microplasmas are studied from an initial cloud until the stages of charged particle overamplification in small spaces, where transients are particularly important. Gas heating, neutral depletion initiation, and electric field reversal are observed, highlighting the close interaction between neutral gas and charged species in governing the evolution of the microplasma.

  19. Neutral gas heating in helium microplasmas

    International Nuclear Information System (INIS)

    The present study details a self-consistent model of charged and neutral particle dynamics which is applied to atmospheric small-space (200 μm) discharges in helium. Hydrodynamic transport equations of the self-consistent and time-dependant model are described with an emphasis on the different terms involved in the close coupling among charged species, neutral species, and the electric field. Those equations are solved by two-dimensional numerical schemes for both species transport and electric field. The microplasmas are studied from an initial cloud until the stages of charged particle overamplification in small spaces, where transients are particularly important. Gas heating, neutral depletion initiation, and electric field reversal are observed, highlighting the close interaction between neutral gas and charged species in governing the evolution of the microplasma

  20. Neutral beam production using negative ions

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, E.B. Jr.

    1978-06-14

    Techniques for producing intense negative ion beams are discussed. These beams are required for intense neutral beam development at energies greater than 150 keV. Handling, acceleration, and stripping of negative ion beams are described.

  1. Neutralized transport of high intensity beams

    International Nuclear Information System (INIS)

    The NTX experiment at the Heavy Ion Fusion Virtual National Laboratory is exploring the performance of neutralized final focus systems for high perveance heavy ion beams. A converging ion beam at the exit of the final focus magnetic system is injected into a neutralized drift section. The neutralization is provided by a metal arc source and an RF plasma source. Effects of a ''plasma plug'', where electrons are extracted from a localized plasma in the upstream end of the drift section, and are then dragged along by the ion potential, as well as the ''volumetric plasma'', where neutralization is provided by the plasma laid down along the ion path, are both studied and their relative effects on the beam spot size are compared. Comparisons with 3-D PIC code predictions will also be presented

  2. The Ethics of Evaluation Neutrality and Advocacy.

    Science.gov (United States)

    Datta, Lois-ellin

    1999-01-01

    Examines arguments for and against evaluation advocacy in terms of the American Evaluation Association's "Guiding Principles for Evaluators" and other statements on advocacy and neutrality. Suggests revision of the "Guiding Principles." (Author/SLD)

  3. Kinetics of neutralization of Po-218

    International Nuclear Information System (INIS)

    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 PoO2+ 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 NO2 or H2O in nitrogen. When PoO2+ is formed, the electron transfer mechanism dominates the neutralization process. The electron is transferred to PoO2+ from molecules with lower ionization potentials. The ionization potential of PoO2+ is also determined to be 10.44 +/- 0.05 eV

  4. TFTR neutral beam injection system conceptual design

    International Nuclear Information System (INIS)

    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)

  5. Nitrogen-neutrality: a step towards sustainability

    International Nuclear Information System (INIS)

    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)

  6. 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....

  7. Negative ion formation and neutralization processes, (1)

    International Nuclear Information System (INIS)

    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)

  8. Economists’ Statement on Network Neutrality Policy

    OpenAIRE

    Kahn, Alfred E.; Bruce M. Owen; Mayo, John; Vernon, John; Lawrence J. White; Waverman, Leonard; Cave, Martin; Patrick A. Messerlin; Joskow, Paul L.; Cramton, Peter; Litan, Robert E.; Robert S. Pindyck; Hahn, Robert W.; Savage, Scott J; Wallsten, Scott

    2007-01-01

    Network neutrality is a policy proposal that would regulate how network providers manage and price the use of their networks. Congress has introduced several bills on network neutrality. Proposed legislation generally would mandate that Internet service providers exercise no control over the content that flows over their lines and would bar providers from charging more for preferentially faster access to the Internet. These proposals must be considered carefully in light of the underlying eco...

  9. Charm Changing Neutral Currents and Supersymmetry

    OpenAIRE

    Lau, Kwong

    2003-01-01

    Flavor changing neutral currents (FCNCs) in the charm system are highly suppressed in the standard model (SM). The theoretical strategies used to suppress FCNCs induced by supersymmetry in the strange and beauty systems need not apply to the charm system. The charm changing neutral current decay D^0-> mu^+ mu^- is studied phenomenologically in the framework of supersymmetric extensions of the standard model. It is found that the decay branching ratio can be enhanced to about 10^{-10}, by havi...

  10. Applications of neutral beam and rf technologies

    International Nuclear Information System (INIS)

    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

  11. Broome and the Intuition of Neutrality

    OpenAIRE

    Rabinowicz, Wlodek

    2009-01-01

    In “Weighing Lives” (2004) John Broome criticizes a view common to many population axiologists. This is the view that population increases with extra people leading decent lives are axiologically neutral: they make the world neither better nor worse, ceteris paribus. Broome argues that this intuition, however, attractive, cannot be sustained, for several independent reasons. I respond to his criticisms and suggest that the neutrality intuition, if correctly interpreted, can after all be defen...

  12. Nonparametric Estimation of Risk-Neutral Densities

    OpenAIRE

    Grith, Maria; Härdle, Wolfgang Karl; Schienle, Melanie

    2010-01-01

    This chapter deals with nonparametric estimation of the risk neutral density. We present three different approaches which do not require parametric functional assumptions on the underlying asset price dynamics nor on the distributional form of the risk neutral density. The first estimator is a kernel smoother of the second derivative of call prices, while the second procedure applies kernel type smoothing in the implied volatility domain. In the conceptually different third approach we assume...

  13. 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.

  14. Extensions of the TEP neutral transport methodology

    International Nuclear Information System (INIS)

    Recent extensions of the Transmission and Escape Probability methodology and its implementation in the 2-D neutral transport code GTNEUT are presented. These extensions address the issues of anisotropy of the neutral distribution function at the interfaces and the non-uniformity of the first collision source in short mean free path regions. Comparisons with Monte Carlo for a number of model problems are discussed. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Production and characterization of a single-chain variable fragment linked alkaline phosphatase fusion protein for detection of O,O-diethyl organophosphorus pesticides in a one-step enzyme-linked immunosorbent assay

    Science.gov (United States)

    A single-chain variable fragment (scFv) and alkaline phosphatase (AP) fusion protein for detection of O, O-diethyl organophosphorus pesticides (OPs) was produced and characterized. The scFv gene was prepared by cloning VL and VH genes from a hybridoma cell secreting monoclonal antibody with broad-s...

  16. 一起由有机磷农药引起食物中毒的调查报告%Investigation report on a case of food poisoning caused by organophosphorus pesticide

    Institute of Scientific and Technical Information of China (English)

    叶瑞国; 罗铭; 梁阳; 覃彦琳; 彭丽; 柒挺

    2011-01-01

    Objective:To analyze field epidemiological investigation and laboratory test results on food poisoning caused by or-ganophosphorus pesticide contamination, providing reference for handling food poisoning cases. Methods: Samples from the patients' vomit, blood and leftover were collected and detection of four common physical and chemical poisoning indexes; organo-phosphorus, tetramine, carbamate esters and fluorine ethyl amide were detected according to the clinical symptoms. Results: or-ganophosphorus pesticide were detected from the pickled food the patients took, the leftover and vomit of patients. Conclusion: This case of food poisoning was caused by organophosphorus pesticide.%目的:总结分析有机磷农药污染引起的食物中毒的现场流行病学调查和实验室检测情况,为类似食物中毒处理提供参考资料.方法:采集患者的呕吐物、血液及剩余食物,根据临床症状进行了有机磷、毒鼠强、氨基甲酸酯、氟乙酰胺四项常见理化中毒指标检测.结果:从患者吃剩的酸料食物和呕吐物中均检出有机磷农药.结论:本起食物中毒由有机磷农药引起.

  17. Trace analysis of some organophosphorus pesticides in rice samples using ultrasound-assisted dispersive liquid-liquid microextraction and high-performance liquid chromatography.

    Science.gov (United States)

    Sharafi, Kiomars; Fattahi, Nazir; Mahvi, Amir Hossein; Pirsaheb, Meghdad; Azizzadeh, Nahid; Noori, Masomeh

    2015-03-01

    An ultrasound-assisted dispersive liquid-liquid microextraction based on solidification of a floating organic drop method followed by high-performance liquid chromatography was developed for the extraction, preconcentration, and determination of trace amounts of organophosphorus pesticides in rice samples. Variables affecting the performance of both steps were thoroughly investigated. Some effective parameters on extraction were studied and optimized. Under the optimum conditions, recoveries for rice sample are in the range of 58.0-66.0%. The calibration graphs are linear in the range of 4-800 μg/kg and, limits of detection and limits of quantification are in the range of 1.5-3 and 4.2-8.5 μg/kg, respectively. The relative standard deviation for 50.0 μg/kg of organophosphorus pesticides in rice sample are in the range of 4.4-5.1% (n = 5). The obtained results show that proposed method is a fast and simple method for the determination of pesticides in cereals. PMID:25641828

  18. Determination of organophosphorus fire retardants and plasticizers in wastewater samples using MAE-SPME with GC-ICPMS and GC-TOFMS detection.

    Science.gov (United States)

    Ellis, Jenny; Shah, Monika; Kubachka, Kevin M; Caruso, Joseph A

    2007-12-01

    Determination of organophosphorus fire retardants and plasticizers at trace levels in wastewater is described. In this work, microwave assisted extraction (MAE) and solid-phase microextraction (SPME) are used for sample preparation to extract and preconcentrate the analytes, followed by analysis by gas chromatography coupled to inductively coupled plasma mass spectrometry (GC-ICP-MS) for phosphorus-specific detection. Gas chromatography coupled to time of flight mass spectrometry (GC-TOF-MS) was used to confirm the organphosphorus fire retardants in wastewater. The detection limits of organophosphorus fire retardants (OPFRs) were 29 ng L(-1) for tri-n-butyl phosphate (TnBP), 45 ng for L(-1) for tris(2-butoxyethyl)phosphate (TBEP), and 50 ng L(-1) for tris(2-ethylhexyl)phosphate (TEHP). Optimized extraction conditions were performed at 65 degrees C for 30 min and with 10% NaCl. Application of MAE during the sample preparation prior to the SPME allowed the detection of tris(2-ethylhexyl) phosphate, which has been difficult to determine in previous work. Application of the method to wastewater samples resulted in detecting 3.1 microg L(-1) P from TnBP, 5.0 microg L(-1) P from TBEP, and 4.0 microg L(-1) P from TEHP. The presence of these compounds were also confirmed by SPME-GC-TOF-MS. PMID:18049771

  19. 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)

    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

  20. [Determination of 21 organophosphorus pesticides in tea by gas chromatography-mass spectrometry coupled with hydroxylated multi-walled carbon nanotubes based on dispersive solid-phase extraction].

    Science.gov (United States)

    Rong, Jiefeng; Wei, Hang; Li, Yijun; Huang, Huoshui; Xu, Meizhu

    2016-02-01

    A rapid determination method of 21 organophosphorus pesticides in tea was developed by QuEChERS method using modified multi-walled carbon nanotubes (MWCNTs-OH), primary-secondary amine (PSA) and MgSO4 coupled with gas chromatography-mass spectrometry. The pesticide residues in tea were extracted with a hexane-acetone (2:1, v/v) mixture, and cleaned up by dispersive solid-phase extraction using MWCNTs-OH and primary-secondary amine (PSA) as the sorbents. After centrifugation and filtration, the target compounds were analyzed by gas chromatography-mass spectrometry and quantified by the external standard method. Under the optimized conditions, good linearities were obtained in the range of 0. 01- 0. 50 mg/kg. The average recoveries were in the range of 81. 5% -109. 4% at three spiked levels, with relative standard deviations (RSDs, n = 5 ) of 2. 3% - 10. 6%. The limits of quantification were 0. 001-0. 040 mg/kg. This method is simple, fast, sensitive, cheap, and can meet the requirements of the rapid detection of organophosphorus pesticides in tea. PMID:27382726

  1. The Phobos neutral and ionized torus

    Science.gov (United States)

    Poppe, A. R.; Curry, S. M.; Fatemi, S.

    2016-05-01

    Charged particle sputtering, micrometeoroid impact vaporization, and photon-stimulated desorption are fundamental processes operating at airless surfaces throughout the solar system. At larger bodies, such as Earth's Moon and several of the outer planet moons, these processes generate tenuous surface-bound exospheres that have been observed by a variety of methods. Phobos and Deimos, in contrast, are too gravitationally weak to keep ejected neutrals bound and, thus, are suspected to generate neutral tori in orbit around Mars. While these tori have not yet been detected, the distribution and density of both the neutral and ionized components are of fundamental interest. We combine a neutral Monte Carlo model and a hybrid plasma model to investigate both the neutral and ionized components of the Phobos torus. We show that the spatial distribution of the neutral torus is highly dependent on each individual species (due to ionization rates that span nearly 4 orders of magnitude) and on the location of Phobos with respect to Mars. Additionally, we present the flux distribution of torus pickup ions throughout the Martian system and estimate typical pickup ion fluxes. We find that the predicted pickup ion fluxes are too low to perturb the ambient plasma, consistent with previous null detections by spacecraft around Mars.

  2. 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.

  3. The neutral losses from C{sub 60}{sup +x} by neutralization-reionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McHale, K.J.; Poice, M.J.; Wesdemiotis, C. [Univ. of Akron, OH (United States)

    1994-12-31

    The most obvious shortcoming of mass spectrometry is the fact that only ions can be detected. However, since the development of neutralization-reionization mass spectrometry (NRMS), neutrals produced by unimolecular reactions in the gas phase can also be observed. One particular case where NRMS is useful is for the determination of the neutral losses from Buckminsterfullerene ions. Due to the high symmetry of Buckminsterfullerene and its very regular pattern of dissociation, as seen in the EI and collisionally activated dissociation (CAD) spectra, the problem of whether the neutrals produced from C{sub 60}{sup +x} ions are sequential C{sub 2} losses or larger C{sub 2n} (n=1,2,3,4,{hor_ellipsis}) clusters has not been solved. Here, the NRMS technique of neutral fragment reionization (N,R) is used to investigate the neutral CAD fragments from C{sub 60}{sup +x}.

  4. Modeling Neutral Densities Downstream of a Gridded Ion Thruster

    Science.gov (United States)

    Soulas, George C.

    2010-01-01

    The details of a model for determining the neutral density downstream of a gridded ion thruster are presented. An investigation of the possible sources of neutrals emanating from and surrounding a NEXT ion thruster determined that the most significant contributors to the downstream neutral density include discharge chamber neutrals escaping through the perforated grids, neutrals escaping from the neutralizer, and vacuum facility background neutrals. For the neutral flux through the grids, near- and far-field equations are presented for rigorously determining the neutral density downstream of a cylindrical aperture. These equations are integrated into a spherically-domed convex grid geometry with a hexagonal array of apertures for determining neutral densities downstream of the ion thruster grids. The neutrals escaping from an off-center neutralizer are also modeled assuming diffuse neutral emission from the neutralizer keeper orifice. Finally, the effect of the surrounding vacuum facility neutrals is included and assumed to be constant. The model is used to predict the neutral density downstream of a NEXT ion thruster with and without neutralizer flow and a vacuum facility background pressure. The impacts of past simplifying assumptions for predicting downstream neutral densities are also examined for a NEXT ion thruster.

  5. [Fe2L3]4+ Cylinders Derived from Bis(bidentate 2-Pyridyl-1,2,3-triazole “Click” Ligands: Synthesis, Structures and Exploration of Biological Activity

    Directory of Open Access Journals (Sweden)

    James D. Crowley

    2013-05-01

    Full Text Available A series of metallosupramolecular [Fe2L3](BF44 “click” cylinders have been synthesized in excellent yields (90%–95% from [Fe(H2O6](BF42 and bis(bidentate pyridyl-1,2,3-triazole ligands. All complexes were characterized by elemental analysis, IR, UV-vis, 1H-, 13C- and DOSY-NMR spectroscopies and, in four cases, the structures confirmed by X-ray crystallography. Molecular modeling indicated that some of these “click” complexes were of similar size and shape to related biologically active pyridylimine-based iron(II helicates and suggested that the “click” complexes may bind both duplex and triplex DNA. Cell-based agarose diffusion assays showed that the metallosupramolecular [Fe2L3](BF44 “click” cylinders display no antifungal activity against S. cerevisiae. This observed lack of antifungal activity appears to be due to the poor stability of the “click” complexes in DMSO and biological media.

  6. Imidazolidine ring as a reduced heterocyclic spacer in a new all-N-donor -bis(bidentate) Schiff base ligand: Synthesis, characterization and electron transfer properties of imidazolidine-bridged dicopper complexes

    Indian Academy of Sciences (India)

    Manindranath Bera; Prasant Kumar Nanda; Uday Mukhopadhyay; Debashis Ray

    2004-03-01

    Low-temperature stoichiometric Schiff base reaction in air in 3 : 1 mole ratio between benzaldehyde and triethylenetetramine (trien) in methanol yields a novel tetraaza m-bis(bidentate) acyclic ligand L. It was characterized by elemental analysis, IR, EI mass and NMR (1H and 13C) spectra. The formation of a five-membered imidazolidine ring from the ethylenediamine backbone as a spacer-cumbridging unit gives rise to a new type of imidazolidine-bridged ligand. A geometric optimisation was made of the synthesized ligand and its complexes by the method of molecular mechanics (MM2) method in order to establish the stable conformations. This hitherto unknown tetraaza acyclic ligand affords new cationic dicopper(I/I) and dicopper(II/II) complexes in good yield. Dicopper(II/II) complex displays weak - transition bands in the visible region, while dicopper(I/I) complex displays strong MLCT band in the same region. Both the dinuclear complexes are of non-intimate nature and show interesting solution electrochemical behaviour. EPR spectral study of -bis(imidazolidino) bridged dicopper(II/II) complex also supports the non-communicative nature of the two copper centres within the same molecule.

  7. Influence of background neutrals on charge exchange neutral spectra in ohmically heated JT-60 plasmas

    International Nuclear Information System (INIS)

    Neutrals emitted from ohmically heated JT-60 plasmas were measured by two neutral particle analysers with different sight-lines. Measured charge exchange spectra presented clear distortion arising from poloidal asymmetry of neutral sources. Ion temperature from charge exchange measurements was 10 - 30 % less than the central temperature at n-bare = (0.5 - 4.0) x 1019 m-3. From the magnitude of the spectra, we determined the neutral density in the core region. At n-bare 19 m-3, the obtained neutral density n0 decreased as n-bare increased, and agreed with the neutral density expected by electron-ion recombination alone at n-bare = (2.5 - 4.0) x 1019 m-3. The result indicates that the neutral density in the core region is determined by penetration of cold neutrals and their generations at n-bare 19 m-3, and also shows that at n-bare > approx 2.5 x 1019 m-3 the neutrals are mainly generated by recombination of protons and electrons. (author)

  8. Age-dependent pharmacokinetic and pharmacodynamic response in preweanling rats following oral exposure to the organophosphorus insecticide chlorpyrifos

    Energy Technology Data Exchange (ETDEWEB)

    Timchalk, Chuck; Poet, Torka S.; Kousba, Ahmed A.

    2006-03-01

    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 CPF-oxon and 3,5,6-trichloro-2-pyridinol (TCP), as well as B-esterase (cholinesterase; ChE) and A-esterase (PON-1) detoxification of CPF-oxon to TCP. The pharmacokinetics of CPF, TCP, and the extent of blood (plasma/RBC), and brain ChE inhibition in rats were determined on postnatal days (PND) -5, -12, and -17 following oral gavage administration of 1 and 10 mg CPF/kg of body weight. For all neonatal ages the blood TCP exceeded the CPF concentration, and within each age group there was no evidence of non-linear kinetics over the dose range evaluated. Younger animals demonstrated a greater sensitivity to ChE inhibition as evident by the dose- and age-dependent inhibition of plasma, RBC, and brain ChE. Of particular importance was the observation that even in rats as young as PND-5, the CYP450 metabolic capacity was adequate to metabolize CPF to both TCP and CPF-oxon based on the detection of TCP in blood and extensive ChE inhibition (biomarker of CPF-oxon) at all ages. In addition, the increase in the blood TCP concentration ({approx}3-fold) in PND-17 rats relative to the response in the younger animals, and the higher blood concentrations of CPF in neonatal rats (1.7 to 7.5-fold) relative to adults was consistent with an increase in CYP450 metabolic capacity with age. This is the first reported study that evaluated both the pharmacokinetics of the parent pesticide, the major metabolite and the extent of ChE inhibition dynamics in the same animals as a function of neonatal age. The results suggest that in the neonatal rat, CPF was rapidly absorbed and metabolized, and the extent of metabolism was age-dependent.

  9. Organophosphorus pesticide and ester analysis by using comprehensive two-dimensional gas chromatography with flame photometric detection

    International Nuclear Information System (INIS)

    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 1D 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 (R2) 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 1tR and 2tR 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

  10. 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

  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. Establishment of Exposure to Organophosphorus Warfare Agents by Means of SPME-GSMS Analysis of Bodily Fluids

    International Nuclear Information System (INIS)

    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

  13. Evidence for neutral-current diffractive neutral pion production from hydrogen in neutrino interactions on hydrocarbon

    CERN Document Server

    Wolcott, J; Altinok, O; Bercellie, A; Betancourt, M; Bodek, A; Bravar, A; Budd, H; Cai, T; Carneiro, M F; Chvojka, J; Devan, J; Dytman, S A; Diaz, G A; Eberly, B; Endress, E; Felix, J; Fields, L; Galindo, R; Gallagher, H; Golan, T; Gran, R; Harris, D A; Higuera, A; Hurtado, K; Kiveni, M; Kleykamp, J; Kordosky, M; Le, T; Maher, E; Manly, S; Mann, W A; Marshall, C M; Caicedo, D A Martinez; McFarland, K S; McGivern, C L; McGowan, A M; Messerly, B; Miller, J; Mislivec, A; Morfin, J G; Mousseau, J; Naples, D; Nelson, J K; Norrick, A; Nuruzzaman,; Paolone, V; Park, J; Patrick, C E; Perdue, G N; Rakotondravohitra, L; Ramirez, M A; Ray, H; Ren, L; Rimal, D; Rodrigues, P A; Ruterbories, D; Schellman, H; Schmitz, D W; Salinas, C J Solano; Sanchez, S F; Tagg, N; Tice, B G; Valencia, E; Walton, T; Wospakrik, M; Zhang, D

    2016-01-01

    The MINERvA experiment observes an excess of events containing electromagnetic showers relative to the expectation from Monte Carlo simulations in neutral-current neutrino interactions with mean beam energy of 4.5 GeV on a hydrocarbon target. The excess is characterized and found to be consistent with neutral-current neutral pion production with a broad energy distribution peaking at 7 GeV and a total cross section of 0.26 +- 0.02 (stat) +- 0.08 (sys) x 10^{-39} cm^{2}. The angular distribution, electromagnetic shower energy, and spatial distribution of the energy depositions of the excess are consistent with expectations from neutrino neutral-current diffractive neutral pion production from hydrogen in the hydrocarbon target. These data comprise the first direct experimental observation and constraint for a reaction that poses an important background process in neutrino oscillation experiments searching for muon neutrino to electron neutrino oscillations.

  14. 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...... from the internet, but also whether it remains an open platform for future growth and innovation. This paper examines the interaction between the key professions driving Network Neutrality policymaking, namely Lawyers, Economists and Engineers. Combining a mapping of their observable policy inputs...... standard, Internet Protocol (IP), which rendered obsolete many of the "normal" restrictive business practises deployed by dominant telecoms companies. As both legal scholars and technologists have explained, the engineering "purity" of IP made the internet a platform for development that was truly...

  15. Biosensor for direct determination of organophosphate nerve agents using recombinant Escherichia coli with surface-expressed organophosphorus hydrolase. 2. Fiber-optic microbial biosensor.

    Science.gov (United States)

    Mulchandani, A; Kaneva, I; Chen, W

    1998-12-01

    A fiber-optic microbial biosensor suitable for direct measurement of organophosphate nerve agents was developed. The unique features of this novel microbial biosensor were the recombinant Escherichia coli cells expressing the enzyme organophosphorus hydrolase on the cell surface and the optical detection of the products of enzyme-catalyzed organophosphate hydrolysis. The use of cells with the metabolic enzyme expressed on the cell surface as a biological sensing element provides advantages of no resistance to mass transport of the analyte and product across the cell membrane and low cost due to elimination of enzyme purification, over the conventional microbial biosensors based on cells expressing enzyme intracellularly and enzyme-based sensors, respectively. The use of an optical transducer allows the detection of different organophosphates in a mixture, presently not feasible with acetylcholinesterase-based biosensors. E. coli cells expressing organophosphorus hydrolase (OPH) on the cell surface were immobilized in low melting temperature agarose on a nylon membrane and attached to the common end of a bifurcated fiber-optic bundle. OPH-expressing E. coli cells catalyzed the hydrolysis of organophosphorus pesticides to form stoichiometric amounts of chromophoric products that absorb light at specific wavelengths. The backscattered radiation of the specific wavelength incident light was measured using a photomultiplier detector and correlated to the organophosphate concentration. The best sensitivity and response time were obtained using a sensor constructed with 1.5 mg of cells operating in pH 9, 50 mM HEPES buffer with 100 mM NaCl and 0.05 mM CoCl2 at 30 degrees C. At optimized conditions, the biosensor measured paraoxon, parathion, and coumaphos pesticides with high selectivity against triazine and carbamate pesticides in approximately 10 min. The lower detection limits were 3 microM for paraoxon and parathion and 5 microM for coumaphos. When stored in the

  16. Treatment experience of acute organophosphorus pesticide poisoning%急性有机磷农药中毒的救治体会

    Institute of Scientific and Technical Information of China (English)

    胡相东

    2014-01-01

    目的:探讨急性有机磷农药中毒的救治体会。方法:2010年3月-2013年10月收治急性有机磷农药中毒患者78例,作为研究对象,回顾性分析所有患者的临床资料。结果:78例患者中,75例患者在经过洗胃、服用阿托品、输血治疗、其他症状治疗等系列治疗后均痊愈出院,有效率96.1%;有3例患者因口服有机磷农药中毒且治疗不及时,抢救无效死亡,死亡率3.9%。结论:及时给予患者彻底的洗胃、正确使用阿托品是及时抢救急性有机磷农药中毒的关键,同时有针对性治疗患者的其他症状可以显著提高治疗效果。%Objective:To explore the treatment experience of acute organophosphorus pesticide poisoning.Methods:78 cases with acute organophosphorus pesticide poisoning were selected from March 2010 to October 2013.They were as the study objects.The clinical data of all patients were retrospectively analyzed.Results:In 78 cases,75 cases were recovered discharge after a series of treatment method,such as gastric lavage,taking atropine,blood transfusion treatment and other symptoms treatment.The effective rate was 96.1%.3 cases with oral excessive pesticide poisoning and delayed treatment were rescue invalid death.The mortality was 3.9%.Conclusion:The timely and thorough gastric lavage for patients and the correct use of atropine are the key to timely rescue acute organophosphorus pesticide poisoning.And targeted therapy in patients with other symptoms can significantly improve the treatment effect.

  17. Neutral fermions in superstring E6-model

    International Nuclear Information System (INIS)

    The mass spectrum of neutral fermion has been studied within the framework of the superstring inspired E6-model. The subgroup SU3CxSU2RxUL(1)xUR(1) is contained in E6 is considered as an intermediate gauge group surviving after flux breaking. At the intermediate energy scale ∼1011 GeV it is spontaneously broken. The obtained mass matrix is consistent with weak universality and allows existence of a light, possibly massless, Majorana neutrino and an additional neutral lepton in the spectrum. The mass of the lepton can be in the region of quark masses

  18. Inducing Risk Neutral Preferences with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2013-01-01

    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...... 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...... toward risk neutrality. This striking result generalizes to the case in which subjects make several lottery choices and one is selected for payment....

  19. Greenhouse gas neutral Germany in 2050

    International Nuclear Information System (INIS)

    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.

  20. Carbon-neutral fuels and energy carriers

    CERN Document Server

    Muradov, Nazim Z

    2011-01-01

    Concerns over an unstable energy supply and the adverse environmental impact of carbonaceous fuels have triggered considerable efforts worldwide to find carbon-free or low-carbon alternatives to conventional fossil fuels. Carbon-Neutral Fuels and Energy Carriers emphasizes the vital role of carbon-neutral energy sources, transportation fuels, and associated technologies for establishing a sustainable energy future. Each chapter draws on the insight of world-renowned experts in such diverse fields as photochemistry and electrochemistry, solar and nuclear energy, biofuels and synthetic fuels, ca

  1. Apparatus for neutralization of accelerated ions

    Science.gov (United States)

    Fink, Joel H.; Frank, Alan M.

    1979-01-01

    Apparatus for neutralization of a beam of accelerated ions, such as hydrogen negative ions (H.sup.-), using relatively efficient strip diode lasers which emit monochromatically at an appropriate wavelength (.lambda. = 8000 A for H.sup.- 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 (.about. 85%) of neutralization.

  2. Direct CP violation in neutral kaon decays

    Indian Academy of Sciences (India)

    Wojciech Wiślicki

    2004-03-01

    The final result of the NA48 experiment is presented and performed at the CERN SPS neutral kaon beams, on the direct CP violation parameter Re$('/)$, as measured from the decay rates of neutral kaons into two pions. The data collected in the years 1997-2001 yield the evidence for the direct CP violation with Re$('/)=(14.7± 2.2)× 10^{-4}$. Description of experimental method and systematics, comparison with the corresponding FNAL result and discussion of some implications for the theory are given.

  3. Shock acceleration in partially neutral plasmas

    OpenAIRE

    Morlino, G.; Amato, E.; P. Blasi(INAF Arcetri); Caprioli, D.

    2010-01-01

    We present the non-linear theory of shock acceleration applied to SNRs expanding into partially neutral plasma. Using this theory we show how the Balmer lines detected from young SNRs can be used to test the efficiency of shocks in the production of cosmic rays. In particular we investigate the effect of charge-exchange between protons and neutral hydrogen occurring in the precursor formed ahead of the shock. In this precursor the CR pressure accelerate the ionized component of the plasma and...

  4. Autologous HIV-1 neutralizing antibodies: emergence of neutralization-resistant escape virus and subsequent development of escape virus neutralizing antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Nielsen, C; Hansen, J E;

    1992-01-01

    The capacity of consecutive human sera to neutralize sequentially obtained autologous virus isolates was studied. HIV-1 was isolated three times over a 48-164-week period from three individuals immediately after seroconversion and from two individuals in later stages of infection. Development of ...

  5. Magnetospheric imaging with low-energy neutral atoms.

    OpenAIRE

    1991-01-01

    Global imaging of the magnetospheric charged particle population can be achieved by remote measurement of the neutral atoms produced when magnetospheric ions undergo charge exchange with cold exospheric neutral atoms. Previously suggested energetic neutral atom imagers were only able to measure neutral atoms with energies typically greater than several tens of keV. A laboratory prototype has been built and tested for a different type of space plasma neutral imaging instrument, which allows ne...

  6. Synthesis of polystyrene supported chelating resin containing an oxygen-nitrogen donor bidentate Schiff base and its nickel(II), cobalt(II), copper(II), iron(III), zinc(II), molybdenum(VI) and uranium(VI) complexes

    International Nuclear Information System (INIS)

    A new bidentate oxygen-nitrogen donor Schiff base supported on polystyrene matrix has been synthesized by the reaction of aminomethylated polystyrene and salicylaldehyde. The chelating resin reacts with metal complex/metal salt and forms metal bound polymers of the formulae: PS-LNi(CH3COO).3DMF, PS-LCo(CH3COO).DMF, PS-LCu(CH3COO).DMF, PS-LCu(CH3COO).CH3OH, PS-LFeCL2.2DMF, PS-LZnCl.CH3OH, PS-LCd(CH3COO).DMF, PS-LCdCl.CH3OH, PS-LMoO2(acetylacetonato) and PS-LUO2(CH3COO).DMF (where PS-L=deprotonated anion of polymer-anchored ligand). The metal bound polymers have been characterized by elemental analysis, IR, electronic spectra and magnetic susceptibility measurements. The complexes PS-LNi(CH3COO).3DMF, PS-LCo(CH3COO).DMF, PS-LCu(CH3COO).DMF, PS-LCu(CH3COO).CH3OH and PS-LFeCl2.2DMF are paramagnetic while the Zn(II), Cd(II), Mo(VI) and U(VI) complexes are diamagnetic. The Co(II) and Cu(II) complexes exhibit a square planar structure, whereas Ni(II), Fe(III), Mo(VI) and U(VI) complexes are octahedral and Zn(II) and Cd(II) complexes are tetrahedral. (author). 29 refs., 1 tab

  7. Neutralization escape mutants define a dominant immunogenic neutralization site on hepatitis A virus

    International Nuclear Information System (INIS)

    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

  8. Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission.

    Science.gov (United States)

    Chrystal, C; Burrell, K H; Grierson, B A; Pace, D C

    2015-10-01

    Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination (CER) diagnostic at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain information about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. The methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access. PMID:26520957

  9. Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission

    Energy Technology Data Exchange (ETDEWEB)

    Chrystal, C. [Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831 (United States); Burrell, K. H.; Pace, D. C. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Grierson, B. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543-0451 (United States)

    2015-10-15

    Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination (CER) diagnostic at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain information about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. The methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access.

  10. Neutralization of rainwater acidity at Kanpur, India

    Science.gov (United States)

    Shukla, Sheo Prasad; Sharma, Mukesh

    2010-07-01

    Particulate matter (PM) levels show significant seasonal variability and this can influence the neutralization of rainwater acidity. Months were grouped in two periods: monsoon (July to October) and non-monsoon (November to June) for studying the seasonal variability in PM and rainwater composition. To clearly establish the cause effect relationship of acid rain neutralization, a two tier model was proposed involving source apportionment of particulates at two levels: (i) ambient air and (ii) rainwater particulate interaction. For modelling purpose, PM10 (n = 100), soil (n = 4) and rainwater (n = 83) samples were collected at Kanpur, India during 2000-2002. The collected samples were analysed for metals and water soluble ion composition to employ factor analysis for source identification. Knowledge of statistical correlation and chemistry fundamentals were combined to estimate the sources for acid rain neutralization. NH4+ was a dominating ion responsible for neutralizing the acidity of rainwater in monsoon period and Ca2+ was dominating in non-monsoon period. Components of secondary particles (SO42- and NO3-) showed affinity with NH4+, signifying the major role that ammonia can play if present in excess of stoichiometric requirements.

  11. The LIPSS search for light neutral bosons

    Energy Technology Data Exchange (ETDEWEB)

    Andrei Afanasev; Oliver K. Baker; Kevin Beard; George Biallas; James Boyce; Minarni Minarni; Roopchan Ramdon; Michelle D. Shinn; Penny Slocum

    2009-07-01

    An overview is presented of the LIPSS experimental search for very light neutral bosons using laser light from Jefferson Lab's Free Electron Laser. This facility provides very high power beams of photons over a large optical range, particularly at infrared wavelengths. Data has been collected in several experimental runs during the course of the past three years, most recently in the Fall of 2009.

  12. 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.

  13. Toxic emissions and devalued CO2-neutrality

    DEFF Research Database (Denmark)

    Czeskleba-Dupont, Rolf

    friendly effects of substituting wood burning for fossil fuels. With reference to Bent Sørensen's classical work on 'Renewable Energy' the assumption of CO2-neutrality regarding incineration is problematised when applied to plants with long rotation periods as trees. Registered CO2-emissions from wood...

  14. Doublet III vacuum vessel neutral beam armor

    International Nuclear Information System (INIS)

    The evolution of the Doublet III neutral beam armor is followed from the initial design of a radiation cooled metallic tile to the present actively cooled graphite design. Results of the thermal and stress analyses that dictated the present design are reviewed

  15. Neutral beam data systems at ORNL

    International Nuclear Information System (INIS)

    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

  16. 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.

  17. Neutrino emissivity under neutral kaon condensation

    OpenAIRE

    Kubis, Sebastian

    2005-01-01

    Neutrino emissivity from neutron star matter with neutral kaon condensate is considered. It is shown that a new cooling channel is opened, and what is more, all previously known channels acquire the greater emissivity reaching the level of the direct URCA cycle in normal matter.

  18. Atomic Structure Calculations for Neutral Oxygen

    OpenAIRE

    Alonizan, Norah; Qindeel, Rabia; Ben Nessib, Nabil

    2016-01-01

    Energy levels and oscillator strengths for neutral oxygen have been calculated using the Cowan (CW), SUPERSTRUCTURE (SS), and AUTOSTRUCTURE (AS) atomic structure codes. The results obtained with these atomic codes have been compared with MCHF calculations and experimental values from the National Institute of Standards and Technology (NIST) database.

  19. SODA ASH TREATMENT OF NEUTRALIZED MINE DRAINAGE

    Science.gov (United States)

    Utilization of acid mine drainage (AMD) streams as a source of potable and industrial water has become a major goal of several proposed AMD treatment schemes. From among the various schemes available, the lime neutralization/soda ash softening process was selected for use at Alto...

  20. Neutral kaons without Weisskopf-Wigner approximation

    International Nuclear Information System (INIS)

    The model-independent formalism is constructed to describe decays of mixed particles without using the Weisskopf-Wigner approximation (WWA). Limitations due to various symmetries are traced for neutral K mesons. As an application we show that effects of CPT violation and going beyond WWA may be separated and studied independently. 16 refs