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Sample records for 5-diphenyl tetrazolium bromide

  1. Kinetic tetrazolium microtiter assay

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L. (Inventor); Stowe, Raymond P. (Inventor); Koeing, David W. (Inventor)

    1992-01-01

    A method for conducting an in vitro cell assay using a tetrazolium indicator is disclosed. The indicator includes a nonionic detergent which solubilizes a tetrazolium reduction product in vitro and has low toxicity for the cells. The incubation of test cells in the presence of zolium bromide and octoxynol (TRITON X-100) permits kinetics of the cell metabolism to be determined.

  2. Nitroblue tetrazolium blood test

    MedlinePlus

    ... called nitroblue tetrazolium (NBT) into a deep blue color. ... If the sample does not change color when NBT is added, the white blood cells are missing the substance needed to kill bacteria. This may be due to chronic granulomatous disease.

  3. Kinetic Tetrazolium Microtiter Assay

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Stowe, Raymond; Koenig, David

    1993-01-01

    Kinetic tetrazolium microtiter assay (KTMA) involves use of tetrazolium salts and Triton X-100 (or equivalent), nontoxic, in vitro color developer solubilizing colored metabolite formazan without injuring or killing metabolizing cells. Provides for continuous measurement of metabolism and makes possible to determine rate of action of antimicrobial agent in real time as well as determines effective inhibitory concentrations. Used to monitor growth after addition of stimulatory compounds. Provides for kinetic determination of efficacy of biocide, greatly increasing reliability and precision of results. Also used to determine relative effectiveness of antimicrobial agent as function of time. Capability of generating results on day of test extremely important in treatment of water and waste, disinfection of hospital rooms, and in pharmaceutical, agricultural, and food-processing industries. Assay also used in many aspects of cell biology.

  4. Identification of anti-invasive but noncytotoxic chemotherapeutic agents using the tetrazolium dye MTT to quantitate viable cells in Matrigel.

    PubMed

    Sasaki, C Y; Passaniti, A

    1998-06-01

    Screening methods for chemotherapeutic agents usually rely on the cytotoxic properties of the drugs. However, agents that inhibit invasion may have more efficacy and cause fewer side effects. Various cellular invasion assays have been used to evaluate these types of compounds, including the modified Boyden chamber, monolayer wound models and Matrigel outgrowth assays. In this report, we have combined the use of the Matrigel outgrowth assay with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) visualization and cell viability dye to visualize invasive cells on Matrigel without magnification. Extraction of the dye's formazan byproduct allows cell viability to be assessed. Using several invasive and noninvasive cell lines, the utility of the method for various target cells was verified. Several established chemotherapeutic agents were also screened for their anti-invasive and/or cytotoxic effects when cultured on Matrigel. Our results suggest that this method may be an easy, inexpensive and nonradioactive alternative for both enumerating cells on Matrigel and screening various tumor cell lines treated with chemotherapeutic agent to look for compounds with noncytotoxic but anti-invasive properties.

  5. Comparison of tetrazolium salt assays for evaluation of drug activity against Leishmania spp.

    PubMed

    Ginouves, Marine; Carme, Bernard; Couppie, Pierre; Prevot, Ghislaine

    2014-06-01

    In French Guiana, leishmaniasis is an essentially cutaneous infection. It constitutes a major public health problem, with a real incidence of 0.2 to 0.3%. Leishmania guyanensis is the causal species most frequently encountered in French Guiana. The treatment of leishmaniasis is essentially drug based, but the therapeutic compounds available have major side effects (e.g., liver damage and diabetes) and must be administered parenterally or are costly. The efficacy of some of these agents has declined due to the emergence of resistance in certain strains of Leishmania. There is currently no vaccine against leishmaniasis, and it is therefore both necessary and urgent to identify new compounds effective against Leishmania. The search for new drugs requires effective tests for evaluations of the leishmanicidal activity of a particular molecule or extract. Microculture tetrazolium assays (MTAs) are colorimetric tests based on the use of tetrazolium salts. We compared the efficacies of three tetrazolium salts-3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT), and 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-8)-for quantification of the promastigotes of various species of Leishmania. We found that the capacity of Leishmania to metabolize a tetrazolium salt depended on the salt used and the species of Leishmania. WST-8 was the tetrazolium salt best metabolized by L. guyanensis and gave the best sensitivity. PMID:24719447

  6. Comparison of Tetrazolium Salt Assays for Evaluation of Drug Activity against Leishmania spp.

    PubMed Central

    Ginouves, Marine; Carme, Bernard; Couppie, Pierre

    2014-01-01

    In French Guiana, leishmaniasis is an essentially cutaneous infection. It constitutes a major public health problem, with a real incidence of 0.2 to 0.3%. Leishmania guyanensis is the causal species most frequently encountered in French Guiana. The treatment of leishmaniasis is essentially drug based, but the therapeutic compounds available have major side effects (e.g., liver damage and diabetes) and must be administered parenterally or are costly. The efficacy of some of these agents has declined due to the emergence of resistance in certain strains of Leishmania. There is currently no vaccine against leishmaniasis, and it is therefore both necessary and urgent to identify new compounds effective against Leishmania. The search for new drugs requires effective tests for evaluations of the leishmanicidal activity of a particular molecule or extract. Microculture tetrazolium assays (MTAs) are colorimetric tests based on the use of tetrazolium salts. We compared the efficacies of three tetrazolium salts—3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT), and 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium (WST-8)—for quantification of the promastigotes of various species of Leishmania. We found that the capacity of Leishmania to metabolize a tetrazolium salt depended on the salt used and the species of Leishmania. WST-8 was the tetrazolium salt best metabolized by L. guyanensis and gave the best sensitivity. PMID:24719447

  7. (1,5-Diphenyl­thio­carbazonato-κS)trimethyl­tin(IV)

    PubMed Central

    Von Eschwege, Karel G.; Swarts, Jannie C.; Aquino, Manuel A. S.; Cameron, T. Stanley

    2012-01-01

    In the title compound, [Sn(C13H11N4S)(CH3)3], the SnIV atom is coordinated by an S atom from the 1,5-diphenyl­thio­carbazonato (L) ligand [Sn—S 2.4710 (6) Å] and by three methyl groups [Sn—C 2.123 (3)–2.130 (2) Å] in a distorted tetra­hedral geometry. The aromatic rings of the L ligand form a dihedral angle of 2.1 (1)°. PMID:23468729

  8. [Development of a novel Francisella tularensis antigen stained with tetrazolium-blue for tularemia microagglutination test].

    PubMed

    Celebi, Bekir; Kılıç, Selçuk

    2013-07-01

    The isolation of Francisella tularensis in cultures is the reference method for the laboratory diagnosis of tularemia. However, due to the limitations such as the low sensitivity and need for high safety level and equipped laboratories, serologic methods are frequently used as diagnostic tools. F.tularensis-specific antibodies may be demonstrated by several methods, however microagglutination test (MA) remains the most common method with its high sensitivity and specificity. The aim of this study was to develop a novel MA test antigen prepared from whole F.tularensis cells and stained with tetrazolium-blue for more clear and easier evaluation. F.tularensis NCTC 10857 strain was cultured on the cysteine heart agar supplemented with 9% sheep blood and bacterial cells were harvested by scraping, collected in physiological saline (PS) and centrifuged at 1500 rpm for 10 minutes. For preparing stock antigen suspension cell concentration was adjusted to OD600=1.5, spectrophotometrically. Tetrazolium-blue solution (BTC [3,3'-(3,3'-Dimethoxy[1,1'-biphenyl]-4,4'-diyl) bis [2,5-diphenyl-2H-tetrazolium dichloride], T4375 Sigma-Aldrich) at the final concentration of 1% was added to cell suspension and incubated at 37°C for 5 hours for absorption. Then, the living cells were chemically inactivated by formaldehyde. Repeating centrifugations were performed to discard excess dye and formaline, then 0.4% formaline saline was added on the sediment. Optimum concentration of this novel antigen (BTC-Ag) for MA test was determined by plate titration method by using standard serum sample with a known MA titer (1/128). The performance of BTC-Ag in MA test was evaluated by using 100 patient sera positive for F.tularensis antibodies, and 100 tularemia negative patient sera (of them 50 were seropositive for brucellosis). All of the results were compared with standard MA test in which safranin-O stained antigen (SO-Ag) was used. There was 100% agreement between the two tests performed with

  9. Vinyl bromide

    Integrated Risk Information System (IRIS)

    Vinyl bromide ; CASRN 593 - 60 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  10. Cyanogen bromide

    Integrated Risk Information System (IRIS)

    Cyanogen bromide ; CASRN 506 - 68 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  11. Nitroblue tetrazolium (NBT) activity in human leucocytes after freezing.

    PubMed

    Hill, R S; Kennedy, M; Mackinder, C

    1978-01-01

    Human peripheral blood leucocytes (neutrophil-rich) were collected either with heparin or acid citrate dextrose, frozen with dimethyl sulphoxide at a controlled rate, stored in liquid nitrogen at--196 degrees C and reconstituted with a solution containing dextran. After reconstitution, 20.2% of cells (in absolute numbers 1 in 5 fresh cells) showed a strongly positive nitroblue tetrazolium (NBT) reaction. The quantitative NBT test confirmed the synthesis of formazan/10(6) reconstituted neutrophilsa s15% of the fresh capacity. A slow titration reconstitution method for cells did not improve the functional capacity of thawed leucocytes as judged by the NBT test. When comparing anticoagulants, heparin increased the post-reconstitution cell yields after freezing and increased the absolute number of reconstituted cells capable of developing a positive NBT reaction. PMID:643322

  12. [The nitroblue tetrazolium test in scarlet fever (author's transl)].

    PubMed

    Trojan, I; Weippl, G

    1975-04-18

    The nitroblue tetrazolium (NBT) test was originally used to diagnose chronic granulomatous disease in childhood. Now it is applied in the diagnosis of acute bacterial infectious diseases, too. The NBT reduction of neutrophils was tested in 27 children with scarlet fever using the modified technique described by K i m et al. The tests were performed in 24 patients between the second and fourth day of illness, before starting antibiotic treatment. In accordance with the results obtained by Humbert et al. in a series of patients with various infectious diseases, 83% of the investigated children showed NBT values of between 41% and 95% (mean value 72%). The percentage of NBT-positive cells was likewise raised in cases of recurrent scarlet fever. Children with scarlet fever complications had highly elevated NBT-reduction values. The control group, consisting of children without infectious diseases, showed values of between 28% and 66% (mean value 33%).

  13. [Bromide encephalopathies (author's transl)].

    PubMed

    Loubrieu, G; Bourin, M; Bizière, K; Breteau, M; Autret, A

    1979-07-01

    Bromide encephalopathies are frequently reported in Northern America and Great Britain. There is no characteristic clinical pattern, the neurological symptoms are multiple, this is readily explained by the diffusion of bromide ions to all regions in the central nervous system. An accurate history (bromide intake, followed by the slow onset of digestive and neuropsychiatric symptoms) as well as an apparent hyperchloremia are of the greatest aid in suggesting the diagnosis. The incidence of this type of intoxication is greater in women over 50. The association of a salt free diet to bromide therapy favors the onset of clinical symptoms because of the competition between bromide and chloride at the choroid plexus and at the renal tubule.

  14. Detection of oxygen species generated by WO{sub 3} modification fullerene/TiO{sub 2} in the degradation of 1,5-diphenyl carbazide

    SciTech Connect

    Meng, Ze-Da; Zhu, Lei; Ullah, Kefayat; Ye, Shu; Oh, Won-Chun

    2014-08-15

    Highlights: • Reactive oxygen species were detected through oxidation reaction from DPCI to DPCO. • Generated reactive oxygen species and hydroxyl radicals can be analysed by DPCI degradation. • C{sub 60} have good effect in photo/ultrasonic degradation process. • Enhanced adsorption capacity can increase the degradation effect. • Photocatalytic activity attributed to photo-absorption effect by C{sub 60} and cooperative effect of WO{sub 3} and TiO{sub 2}. - Abstract: In the present work, powders with different relative mole ratios of WO{sub 3}-fullerene/TiO{sub 2} were irradiated by visible light and ultrasonic. The composite obtained was characterized by BET surface area measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), fourier transform infrared (FT-IR), transmission electron microscopy (TEM) and UV–vis analysis. A methylene blue (MB) solution under visible light and ultrasonic irradiation was used to determine the catalytic activity. The generation of reactive oxygen species were detected through the oxidation reaction from 1,5-diphenyl carbazide (DPCI) to 1,5-diphenyl carbazone (DPCO). Finally, we performed experiments to find the optimum relative mole ratio of fullerene for the degradation of MB.

  15. Liquid-crystalline heterodimesogens and ABA-heterotrimesogens comprising a bent 3,5-diphenyl-1,2,4-oxadiazole central unit

    PubMed Central

    Shanker, Govindaswamy; Prehm, Marko

    2012-01-01

    Summary Three new types of terminally connected ABA-heterotrimesogens and heterodimesogens, composed of a bent 3,5-diphenyl-1,2,4-oxadiazole central unit and one or two rod-shaped 4-cyanobiphenyl cores or one 2-phenyl-1,3,4-thiadiazole core, connected by flexible spacers, have been synthesized, and their mesomorphic behavior was studied by optical polarizing microscopy (PM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD). All dimesogens exhibit broad ranges of cybotactic nematic phases (NcybA and NcybC), in some cases accompanied by additional mesophases (CybA or SmC) at lower temperature. The combination of the 3,5-diphenyl-1,2,4-oxadiazole unit with one cyanobiphenyl core leads to the removal of tilted smectic and cybotactic nematic phases (SmC, NcybC), which are replaced by the nontilted CybA phases and nematic phases composed of SmA-type clusters (NcybA). The orthogonal cybotactic nematic phases of bent-core mesogens are of special interest for achieving biaxial nematic phases of the orthorhombic type. The orthogonal (NcybA) and skewed (NcybC) cybotactic nematic phases were distinguished by XRD and optical observations. PMID:22509219

  16. Anticancer and structure-activity relationship evaluation of 3-(naphthalen-2-yl)-N,5-diphenyl-pyrazoline-1-carbothioamide analogs of chalcone.

    PubMed

    Lee, Youngshim; Kim, Beom Soo; Ahn, Seunghyun; Koh, Dongsoo; Lee, Young Han; Shin, Soon Young; Lim, Yoongho

    2016-10-01

    To identify new potent chemotherapeutic agents, we synthesized compounds with 3-(naphthalen-2-yl)-N,5-diphenyl-pyrazoline-1-carbothioamide (NDPC) skeletons and evaluated their cytotoxicities using a clonogenic long-term survival assay. Their half-maximal cell growth inhibitory concentrations ranged from a few hundred nanomolars to a few micromolars. Further biological experiments including flow cytometry and western blotting analysis were performed with the derivative showing the best cytotoxicity. To identify a target protein of the selected compound, an in vitro kinase assay was carried out, which revealed that aurora kinases A and B were inhibited by the test compound, and this was confirmed using western blot analysis. The molecular binding mode between the selected compound and the kinases was elucidated using in silico docking. The structural conditions required for good cytotoxicity were identified based on the quantitative relationships between the physicochemical properties of the derivatives and their cytotoxicities.

  17. Applicability of tetrazolium salts for the measurement of respiratory activity and viability of groundwater bacteria.

    PubMed

    Hatzinger, Paul B; Palmer, Patrick; Smith, Richard L; Peñarrieta, Cecilia T; Yoshinari, Tadashi

    2003-01-01

    A study was undertaken to measure aerobic respiration by indigenous bacteria in a sand and gravel aquifer on western Cape Cod, MA using tetrazolium salts and by direct oxygen consumption using gas chromatography (GC). In groundwater and aquifer slurries, the rate of aerobic respiration calculated from the direct GC assay was more than 600 times greater than that using the tetrazolium salt 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl tetrazolium chloride (INT). To explain this discrepancy, the toxicity of INT and two additional tetrazolium salts, sodium 3'-[1-(phenylamino)-carbonyl]-3,4-tetrazolium]-bis(4-methoxy-6-nitro) benzenesulfonic acid hydrate (XTT) and 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), to bacterial isolates from the aquifer was investigated. Each of the three tetrazolium salts was observed to be toxic to some of the groundwater isolates at concentrations normally used in electron transport system (ETS) and viability assays. For example, incubation of cells with XTT (3 mM) caused the density of four of the five groundwater strains tested to decline by more than four orders of magnitude. A reasonable percentage (>57%) of cells killed by CTC and INT contained visible formazan crystals (the insoluble, reduced form of the salts) after 4 h of incubation. Thus, many of the cells reduced enough CTC or INT prior to dying to be considered viable by microscopic evaluation. However, one bacterium (Pseudomonas fluorescens) that remained viable and culturable in the presence of INT and CTC, did not incorporate formazan crystals into more than a few percent of cells, even after 24 h of incubation. This strain would be considered nonviable based on traditional tetrazolium salt reduction assays. The data show that tetrazolium salt assays are likely to dramatically underestimate total ETS activity in groundwater and, although they may provide a reasonable overall estimate of viable cell numbers in a community of groundwater bacteria, some specific strains may be

  18. Applicability of tetrazolium salts for the measurement of respiratory activity and viability of groundwater bacteria

    USGS Publications Warehouse

    Hatzinger, P.B.; Palmer, P.; Smith, R.L.; Penarrieta, C.T.; Yoshinari, T.

    2003-01-01

    A study was undertaken to measure aerobic respiration by indigenous bacteria in a sand and gravel aquifer on western Cape Cod, MA using tetrazolium salts and by direct oxygen consumption using gas chromatography (GC). In groundwater and aquifer slurries, the rate of aerobic respiration calculated from the direct GC assay was more than 600 times greater than that using the tetrazolium salt 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl tetrazolium chloride (INT). To explain this discrepancy, the toxicity of INT and two additional tetrazolium salts, sodium 3???-[1-(phenylamino)-carbonyl]-3,4-tetrazolium]-bis(4-methoxy-6-nitro) benzenesulfonic acid hydrate (XTT) and 5-cyano-2,3-ditolyl tetrazolium chloride (CTC), to bacterial isolates from the aquifer was investigated. Each of the three tetrazolium salts was observed to be toxic to some of the groundwater isolates at concentrations normally used in electron transport system (ETS) and viability assays. For example, incubation of cells with XTT (3 mM) caused the density of four of the five groundwater strains tested to decline by more than four orders of magnitude. A reasonable percentage (>57%) of cells killed by CTC and INT contained visible formazan crystals (the insoluble, reduced form of the salts) after 4 h of incubation. Thus, many of the cells reduced enough CTC or INT prior to dying to be considered viable by microscopic evaluation. However, one bacterium (Pseudomonas fluorescens) that remained viable and culturable in the presence of INT and CTC, did not incorporate formazan crystals into more than a few percent of cells, even after 24 h of incubation. This strain would be considered nonviable based on traditional tetrazolium salt reduction assays. The data show that tetrazolium salt assays are likely to dramatically underestimate total ETS activity in groundwater and, although they may provide a reasonable overall estimate of viable cell numbers in a community of groundwater bacteria, some specific strains may

  19. Rapacuronium bromide (Organon Teknika).

    PubMed

    Plowman, A N

    1999-07-01

    Organon Teknika's rapacuronium bromide (Org-9487), the 16-N-allyl, 17-beta-propionate analog of vecuronium bromide, is in phase III clinical trials in the US and Europe for potential use as an anesthetic. It is a steroidal neuromuscular blocking drug characterized by low potency, rapid rate of block development and short time course of neuromuscular blocking action as compared with other non-depolarizing compounds [170210,221422]. A multicenter, randomized, assessor-blind, placebo-controlled, dose-finding study in patients undergoing tracheal intubation showed that the drug produced a dose dependent neuromuscular block. Doses of 1.5 to 2 mg/kg allowed rapid intubation and short duration of action [273336]. Another study showed that the drug does not cause cardiovascular side-effects [273336]. A meeting was held in Europe on 8 February 1999 to brief company employees on the registration and release of rapacuronium [319211] for which the company anticipates a launch in late 1999 [320706]. Organon estimates that the market value of Org-9487 is between dollar 100 m and dollar 250 m a year, each for Europe and the US [221422].

  20. Highly sensitive optical sensor that detects Hg2+ and Cu2+ by immobilizing dicarboxylate 1,5-diphenyl-3-thiocarbazone on surface functionalized PVA microspheres

    NASA Astrophysics Data System (ADS)

    Bai, Xue; Gu, Haixin; Hua, Zulin; Dai, Zhangyan; Yang, Bei; Li, Yulong

    2015-11-01

    A novel optical sensor to detect Hg2+ and Cu2+ is prepared by immobilizing a synthesized dicarboxylate 1,5-diphenyl-3-thiocarbazone (DDT) group on functionalized polyvinyl alcohol (PVA) microspheres. This optical sensor is successfully fabricated by extensive characterization with Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Its colorimetric properties, selectivity, sensitivity, and reversibility are investigated as well. In this sensing system, DDT-PVA selectively recognized multiple heavy metal ions, as indicated by the changes in color from orange to scarlet for Hg2+ and from orange to gray for Cu2+. In particular, this optical sensor exhibits the most apparent color changes at pH levels of 12 and 2. Hence, Hg2+ and Cu2+ can be detected in aqueous solution at minimum detection limits of 0.053 and 0.132 μM, respectively, with a UV-vis spectrometer. Furthermore, the sensor can be regenerated by ethylene diamine tetraacetic acid and reused several times. Therefore, the optical sensor can detect Hg2+ because of its selectivity, sensitivity, and reversibility.

  1. Iron bromide vapor laser

    NASA Astrophysics Data System (ADS)

    Sukhanov, V. B.; Shiyanov, D. V.; Trigub, M. V.; Dimaki, V. A.; Evtushenko, G. S.

    2016-03-01

    We have studied the characteristics of a pulsed gas-discharge laser on iron bromide vapor generating radiation with a wavelength of 452.9 nm at a pulse repetition frequency (PRF) of 5-30 kHz. The maximum output power amounted to 10 mW at a PRF within 5-15 kHz for a voltage of 20-25 kV applied to electrodes of the discharge tube. Addition of HBr to the medium produced leveling of the radial profile of emission. Initial weak lasing at a wavelength of 868.9 nm was observed for the first time, which ceased with buildup of the main 452.9-nm line.

  2. Potassium bromide-associated panniculitis.

    PubMed

    Boynosky, N A; Stokking, L B

    2014-12-01

    Two cases of panniculitis associated with administration of potassium bromide in dogs are reported. Both dogs were treated with potassium bromide for idiopathic epilepsy for over 1 year. Dose increases in both cases were associated with panniculitis, characterised by painful subcutaneous nodules in a generalised distribution over the trunk. Nodule eruption waxed and waned in one dog and was persistent in the other. In both cases, panniculitis was accompanied by lethargy and pyrexia. Panniculitis, lethargy and pyrexia resolved and failed to recur after discontinuation of potassium bromide. No other cause of panniculitis could be determined for either dog. Panniculitis has been reported after administration of potassium bromide in humans and may be a form of drug-induced erythema nodosum. To the authors' knowledge, these are the first reports of potassium bromide-associated panniculitis in dogs.

  3. Tetrazolium reduction as an aid for streptococcal growth detection with agar dilution susceptibility testing.

    PubMed Central

    Coudron, P E; Ford, J M; Dalton, H P

    1983-01-01

    A dye reduction method for determining a definitive endpoint with agar dilution susceptibility testing has been developed. Bacterial growth was determined by applying to the inoculum spot a dye solution containing 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride and phenazine methosulfate. Viable colonies reduced the tetrazolium salt to a visible red color within 3 to 5 min. The minimum inhibitory concentrations of six antimicrobial agents tested against 167 clinical streptococcal isolates were recorded before and after the addition of the tetrazolium-phenazine methosulfate solution. A total of 252 discrepancies (25%) were observed, and of these, 30 (12%) differed by more than one tested antibiotic concentration. Endpoint reproducibility of the dye procedure was assessed by four technologists in a double-blind study. A 2.7-fold reduction in disagreement was observed when the dye was used. Use of the tetrazolium-phenazine methosulfate solution involves little deviation from standard antimicrobial susceptibility test procedures and yields more accurate, as well as reproducible, susceptibility results. PMID:6630459

  4. Alcohol solutions of triphenyl-tetrazolium chloride as high-dose radiochromic dosimeters

    NASA Astrophysics Data System (ADS)

    Kovács, A.; Wojnárovits, L.; El-assy, N. B.; Afeefy, H. Y.; Al-Sheikhly, M.; Walker, M. L.; McLaughlin, W. L.

    1995-09-01

    The radiolytic reduction of colorless tetrazolium salts in aqueous solution to the highly colored formazan dye is a well-known acid-forming radiation chemical reaction. Radiochromic thin films and three-dimensional hydrocolloid gels have been used for imaging and mapping absorbed dose distributions. The high solubility of 2,3,5-triphenyl-tetrazolium chloride (TTC) in alcohols provides a useful liquid dosimeter (45 mM TTC in aerated ethanol) and shows a linear response of absorbance increase (λmax = 480 nm) with dose over the range 1-16 kGy. The linear molar absorption coefficient (ɛm) for the formazan at the absorption peak is 1.5 × 103 m2 mol-1, and the radiation chemical yield for the above solution is G (formazan) = 0.014 μmol J-1. The irradiation temperature coefficient is about 0.8 percent per degree Celsius rise in temperature over the temperature range 0-30 °C but is much larger between 30° and 60 °C. The unirradiated and irradiated solutions are stable over at least five days storage at normal laboratory temperature in the dark, but when stored in daylight at elevated temperature, the unirradiated solution in sealed amber glass ampoules undergoes slow photolytic dye formation, and the irradiated solution experiences initial fading and subsequent reversal (photochromism) when exposed to direct sunlight.

  5. Discovery of potent 3,5-diphenyl-1,2,4-oxadiazole sphingosine-1-phosphate-1 (S1P1) receptor agonists with exceptional selectivity against S1P2 and S1P3.

    PubMed

    Li, Zhen; Chen, Weirong; Hale, Jeffrey J; Lynch, Christopher L; Mills, Sander G; Hajdu, Richard; Keohane, Carol Ann; Rosenbach, Mark J; Milligan, James A; Shei, Gan-Ju; Chrebet, Gary; Parent, Stephen A; Bergstrom, James; Card, Deborah; Forrest, Michael; Quackenbush, Elizabeth J; Wickham, L Alexandra; Vargas, Hugo; Evans, Rose M; Rosen, Hugh; Mandala, Suzanne

    2005-10-01

    A class of 3,5-diphenyl-1,2,4-oxadiazole based compounds have been identified as potent sphingosine-1-phosphate-1 (S1P1) receptor agonists with minimal affinity for the S1P2 and S1P3 receptor subtypes. Analogue 26 (S1P1 IC50 = 0.6 nM) has an excellent pharmacokinetics profile in the rat and dog and is efficacious in a rat skin transplant model, indicating that S1P3 receptor agonism is not a component of immunosuppressive efficacy.

  6. A tetrazolium-based colorimetric assay for titration of neutralizing antibodies against vaccinia virus.

    PubMed

    Ifrah, M; Stienlauf, S; Shoresh, M; Katz, E

    1998-01-01

    A colorimetric assay for titration of neutralizing antibodies against vaccinia virus was developed. The test is based on the ability of live cells in culture to reduce the yellow tetrazolium salt MTT (thiazolyl-blue), to its blue formazan derivative. Antisera from individuals vaccinated with vaccinia virus against smallpox were serially diluted, incubated with 100 plaque-forming units (PFU) of vaccinia virus for 1 hour at 37 degrees C, and then transferred to a 96-well plate containing monolayers of B-SC-1 cells. After incubation for 3 to 4 days at 37 degrees C, when more than 80% of the control infected cultures exhibited high degree of cytopathogenic effect, MTT was added. The absorbance of the formazan formed and extracted by dimethylsulfoxide was read at 492 nm by an automatic microplate spectrophotometer. A good correlation was found between the results obtained using this newly developed method and those of the plaque-reduction assay.

  7. RAPID TETRAZOLIUM DYE REDUCTION ASSAY TO ASSESS THE BACTERICIDAL ACTIVITY OF OYSTER (CRASSOSTREA VIRGINICA) HEMOCYTES AGAINST VIBRIO PARAHAEMOLYTICUS

    EPA Science Inventory

    An assay was developed to assess the ability of oyster, Crassostrea virginica, hemocytes to kill the human pathogenic bacterium, Vibrio parahaemolyticus (ATCC 17802). Bacterial killing was estimated colorimetrically by the enzymatic reduction of a tetrazolium dye, 3-(4,5-dimethyl...

  8. A comparison of infarct identification with technetium-99m pyrophosphate and staining with triphenyl tetrazolium chloride

    SciTech Connect

    Izquierdo, C.; Devous, M.D. Sr.; Nicod, P.; Buja, L.M.; Parkey, R.W.; Bonte, F.J.; Willerson, J.T.; Lewis, S.E.

    1983-06-01

    The topographic relationship between the uptake of technetium-99m pyrophosphate (PPi) and myocardial infarction delineated by 2,3,5-triphenyl tetrazolium chloride (TTC) was studied in a canine model of permanent coronary occlusion (24-48 hr). Photographs of TTC staining and scintigraphic images of PPi uptake were planimetered for infarct area. In addition, narrow tissue samples (3 X 10 mm) were taken on both sides of the TTC border and counted for PPi uptake. A significant correlation (p less than 0.001) was found between area of PPi uptake and area of myocardium unstained by TTC (r . 0.84 in epicardium and r . 0.91 in endocardium). The slope relating PPi to TTC for all infarcts was 1.01 +/- 0.11, indicating that variations in infarct size were followed equally by the two techniques. Tissue counting showed the ratio of PPi activity just inside the infarct to activity just outside the infarct to be 9.2 +/- 0.6 (mean +/- s.e.m.). Thus, PPi is distributed topographically in a manner identical to the distribution of irreversibly injured myocardium as delineated by TTC.

  9. Optimizing a Candida Biofilm Microtiter Plate Model for Measurement of Antifungal Susceptibility by Tetrazolium Salt Assay▿

    PubMed Central

    Nett, Jeniel E.; Cain, Michael T.; Crawford, Kyler; Andes, David R.

    2011-01-01

    Candida spp. infect medical devices, such as venous and urinary catheters, by adhering to the surface and forming a community of drug-resistant cells surrounded by a matrix. The ability to measure drug activity during this biofilm mode of growth is of interest for the investigation of resistance mechanisms and novel antifungal therapies. The tetrazolium salt (XTT) reduction assay is the test most commonly used to estimate viable biofilm growth and to examine the impact of biofilm therapies. The primary goal of the current experiments was to identify assay variables that affect the XTT assay result in order to improve assay reproducibility, sensitivity, and throughput for the study of antifungal activity. The species used in the current studies included Candida albicans, C. parapsilosis, and C. glabrata. The assay variables that were studied included the impact of culture conditions, the duration of biofilm growth, the timing and frequency of drug administration, the XTT source and concentration, and the duration of XTT incubation. The conditions that impacted the assay readout and altered assay sensitivity included the duration of biofilm growth, the frequency of drug dosing, and the duration of XTT incubation. Several factors were found to reduce time and assay expense, including the elimination of washing steps, the shortening of incubation times, and the use of lower XTT concentrations. A description of assay pitfalls and troubleshooting is included. Recognition of these technical variables should allow investigators to better design reproducible biofilm therapeutic studies. PMID:21227984

  10. Vibrational spectroscopic studies, NMR, HOMO-LUMO, NLO and NBO analysis of 1-(2-nitrobenzoyl)-3,5-diphenyl-4,5-dihydro-1H-pyrazole with use X-ray diffractions and DFT calculations

    NASA Astrophysics Data System (ADS)

    Demir, Sibel; Tinmaz, Feyza; Dege, Necmi; Ilhan, Ilhan Ozer

    2016-03-01

    The crystal and molecular structure of the title compound, 1-(2-nitrobenzoyl)-3,5-diphenyl-4,5-dihydro-1H-pyrazole, was reported and confirmed by single crystal X-ray diffraction and spectroscopic data. The structure, geometry optimization, vibrational frequencies and nuclear magnetic resonance were also investigated. Stability of the molecule arising from hyperconjugative interactions and charge delocalisation was analysed using natural bond orbital analysis. The results show that charge in electron density (ED) in the σ∗ and π∗ antibonding orbitals and second-order delocalisation energies E(2) confirms the occurrence of intramolecular charge transfer within the molecule. Satisfactory theoretical aspects were made for the stable conformer of the molecule using density functional theory DFT-B3LYP methods with the 6-311G++(d,p) basis set.

  11. Lanthanum Bromide Detectors for Safeguards Measurements

    SciTech Connect

    Wright, J.

    2011-05-25

    Lanthanum bromide has advantages over other popular inorganic scintillator detectors. Lanthanum bromide offers superior resolution, and good efficiency when compared to sodium iodide and lanthanum chloride. It is a good alternative to high purity germanium detectors for some safeguards applications. This paper offers an initial look at lanthanum bromide detectors. Resolution of lanthanum bromide will be compared lanthanum chloride and sodium-iodide detectors through check source measurements. Relative efficiency and angular dependence will be looked at. Nuclear material spectra, to include plutonium and highly enriched uranium, will be compared between detector types.

  12. Measuring methyl bromide emissions from fields

    SciTech Connect

    Yates, S.R.; Gan, J.; Ernst, F.F.; Yates, M.V.

    1995-12-31

    Methyl bromide is used extensively for pest control. Recent evidence suggests that methyl bromide may react with stratospheric ozone and, due to the Clean Air Act, is scheduled for phase-out within the next 5 to 10 years. As indicated in a recent report from The National Agricultural Pesticide Impact Assessment Program, there will be substantial economic impact on the agricultural community if the use of methyl bromide is restricted. There are several areas of uncertainty concerning the agricultural use of methyl bromide. Foremost is the quantification of mass emitted to the atmosphere from agricultural fields. To address this, two field experiments were conducted to directly measure methyl bromide emissions. In the first experiment, methyl bromide was injected at approximately 25 cm depth and the soil was covered with 1 mil high-density polyethylene plastic. The second experiment was similar except that methyl bromide was injected at approximately 68 cm depth and the soil was not covered. From these experiments, the emission rate into the atmosphere and the subsurface transport of methyl bromide was determined. Both experiments include a field-scale mass balance to verify the accuracy of the flux-measurement methods as well as to check data consistency. The volatilization rate and mass lost was determined from estimates of the degradation and from several atmospheric and chamber flux methods.

  13. An evaluation of three new-generation tetrazolium salts for the measurement of respiratory activity in activated sludge microorganisms.

    PubMed

    McCluskey, C; Quinn, J P; McGrath, J W

    2005-04-01

    XTT (3'-[1-[(phenylamino)-carbonyl]-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzenesulfonic acid hydrate), MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt), and WST-1 (4-(3-4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio)-1,3-benzenedisulfonate) are tetrazolium salts that have become commercially available only in relatively recent years; they differ from earlier such compounds in that their reduction gives rise to a formazan product that is water soluble. We have established the sites in the prokaryotic respiratory chain at which each of the dyes is reduced to its corresponding formazan and have evaluated the suitability of each for the colorimetric estimation of electron transport system activity in populations of activated sludge microorganisms. Reduction of all three tetrazolium salts was shown to be proportional to cell biomass and oxygen uptake and to be susceptible to low levels of the reference toxicant 3,5-dichlorophenol. XTT, which was not inhibitory at concentrations of up to 2 mM and was reduced by 91% of isolates from a sample of culturable activated sludge bacteria, was chosen for further assay development. XTT-formazan production was found to be stimulated by the availability of an exogenous carbon and energy source, and by the presence of the electron-coupling agent phenazine methosulfate. Less than 3% of XTT reduction by an activated sludge sample was abiotic. An assay based on this compound could be a valuable and simple tool for the routine monitoring of the performance of wastewater treatment systems.

  14. Potassium bromide method of infrared sampling

    USGS Publications Warehouse

    Milkey, R.G.

    1958-01-01

    In the preparation of potassium bromide pressed windows for use in the infrared analysis of solids, severe grinding of the potassium bromide powder may produce strong absorption bands that could interfere seriously with the spectra of the sample. These absorption bands appear to be due to some crystal alteration of the potassium bromide as a result of the grinding process. They were less apt to occur when the coarser powder, which had received a relatively gentle grinding, was used. Window blanks prepared from the coarser powders showed smaller adsorbed water peaks and generally higher over-all transmittance readings than windows pressed from the very fine powders.

  15. Simple and sensitive high-performance liquid chromatographic determination of methamphetamines in human urine as derivatives of 4-(4,5-diphenyl-1H-imidazol-2-yl) benzoyl chloride, a new fluorescence derivatization reagent.

    PubMed

    Al-Dirbashi, O; Qvarnstrom, J; Irgum, K; Nakashima, K

    1998-08-01

    A simple, rapid and highly sensitive high-performance liquid chromatographic method for the determination of methamphetamine and its metabolites in human urine was developed. Without tedious pretreatment procedures, aliquots of methamphetamine spiked or abusers' urine samples were simply acidified, dried under a stream of N2 gas, and then derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl) benzoyl chloride in acetonitrile in the presence of traces of triethylamine. Five derivatives were isocratically separated within 33 min by an ODS column, and the effluent was monitored at 440 nm (lambda(ex), 330 nm). Using 1-phenylethylamine as an internal standard calibration curves were confirmed to be linear up to at least 2x10(-5) M in urine with correlation coefficients of 0.998-1.000, while the detection limits at S/N=3 were 0.6-5.2 fmol per 5-microl injection. The relative standard deviations (n=5) of inter- and intra-day variations were less than 8.9%. The correlation between the concentrations of methamphetamine and amphetamine in urine determined by the proposed method and another currently accepted one was satisfactory. The method was successfully applied to urine samples collected from methamphetamine addicts.

  16. Emission of methyl bromide from biomass burning

    SciTech Connect

    Manoe, S.; Andreae, M.O. )

    1994-03-04

    Bromine is, per atom, far more efficient than chlorine in destroying stratospheric ozone, and methyl bromide is the single largest source of stratospheric bromine. The two main previously known sources of this compound are emissions from the ocean and from the compound's use as an agricultural pesticide. Laboratory biomass combustion experiments showed that methyl bromide was emitted in the smoke from various fuels tested. Methyl bromide was also found in smoke plumes from wildfires in savannas, chaparral, and boreal forest. Global emissions of methyl bromide from biomass burning are estimated to be in the range of 10 to 50 gigagrams per year, which is comparable to the amount produced by ocean emission and pesticide use and represents a major contribution ([approximately]30 percent) to the stratospheric bromine budget.

  17. Investigation of drug interactions with pinaverium bromide.

    PubMed

    Devred, C; Godeau, P; Guerot, C; Librez, P; Mougeot, G; Orsetti, A; Segrestaa, J M

    1986-01-01

    A series of studies was carried out at 6 centres to investigate possible drug interaction between the spasmolytic, pinaverium bromide, and cardiac glycosides, anticoagulants and hypoglycaemic agents given to patients as part of the long-term treatment of their condition. The results of clinical and laboratory investigations did not show any evidence of pinaverium bromide interfering with the action or activity of any of the drugs studied. PMID:3084176

  18. Spiro-oxindole derivative 5-chloro-4',5'-diphenyl-3'-(4-(2-(piperidin-1-yl) ethoxy) benzoyl) spiro[indoline-3,2'-pyrrolidin]-2-one triggers apoptosis in breast cancer cells via restoration of p53 function.

    PubMed

    Saxena, Ruchi; Gupta, Garima; Manohar, Murli; Debnath, Utsab; Popli, Pooja; Prabhakar, Yenamandra S; Konwar, Rituraj; Kumar, Sandeep; Kumar, Atul; Dwivedi, Anila

    2016-01-01

    Breast cancer remains a significant health problem due to the involvement of multiple aberrant and redundant signaling pathways in tumorigenesis and the development of resistance to the existing therapeutic agents. Therefore, the search for novel chemotherapeutic agents for effective management of breast cancer is still warranted. In an effort to develop new anti-breast cancer agents, we have synthesized and identified novel spiro-oxindole derivative G613 i.e. 5-chloro-4',5'-diphenyl-3'-(4-(2-(piperidin-1-yl) ethoxy) benzoyl) spiro[indoline-3,2'-pyrrolidin]-2-one, which has shown growth inhibitory activity in breast cancer cells. The present study was aimed to explore the mechanism of anti-tumorigenic action of this newly identified spiro-oxindole compound. Compound G613 inhibited the Mdm2-p53 interaction in breast cancer cells and tumor xenograft. It caused restoration of p53 function by activating its promoter activity, triggering its nuclear accumulation and preventing its ubiquitination and proteasomal degradation. Supportively, molecular docking studies revealed considerable homology in the docking mode of G613 and the known Mdm2 inhibitor Nutlin-3, to p53 binding pocket of Mdm2. The activation of p53 led to upregulation of p53 dependent pro-apoptotic proteins, Bax, Pumaα and Noxa and enhanced interaction of p53 with bcl2 member proteins thus triggering both transcription-dependent and transcription-independent apoptosis, respectively. Additionally, the compound decreased estrogen receptor activity through sequestration of estrogen receptor α by p53 thereby causing a decreased transcriptional activation and expression of proliferation markers. In conclusion, G613 represents a potent small-molecule inhibitor of the Mdm2-p53 interaction and can serve as a promising lead for developing a new class of anti-cancer therapy for breast cancer patients.

  19. Mutagenic effects of lead (II) bromide.

    PubMed

    Maslat, A O; Haas, H J

    1989-12-01

    The mutagenicity of lead (II) bromide (a combustion product of the gasoline additives lead (IV) tetraethyl and 1,2-dibromoethane) was investigated using various strains of bacteria. Taking prodigiosin (the red pigment) production as a marker, lead (II) bromide was found to be mutagenic in S. marcescens, leading to the appearance of white mutant colonies that are unable to produce such a pigment. This compound was also found to be mutagenic in E. coli KMBL1851, resulting in the appearance of rifampicin-resistant mutants in addition to Met+ and His+ revertants. Some of the S. marcescens mutants were found to be reversible, able to resynthesize prodigiosin. Differences in the sensitivity to antibiotics as well as in the biochemical properties were detected between the mutants and their corresponding wild types. Lead (II) bromide gave positive results in the Ames test performed with strain TA 1535.

  20. Effects of pinaverium bromide on Oddi's sphincter.

    PubMed

    DiSomma, C; Reboa, G; Patrone, M G; Mortola, G P; Sala, G; Ciampini, M

    1986-01-01

    Twelve to 15 days after cholecystectomy, endocholedochal pressure was measured in ten patients before and one hour after oral administration of 15 mg of pinaverium bromide (six patients) or placebo. The mean endocholedochal pressure was 7.1 +/- 0.25 mmHg before and 3.1 +/- 0.2 mmHg after pinaverium (P less than 0.01), and 7.0 +/- 0.2 and 6.8 +/- 1.2 mmHg in the placebo-treated patients. The results suggest that pinaverium bromide has a specific effect on the common bile duct and probably on Oddi's sphincter. PMID:3815457

  1. [The clinical pharmacological profile of pinaverium bromide].

    PubMed

    Guslandi, M

    1994-04-01

    Pinaverium bromide is a locally acting spasmolytic agent of the digestive tract. Its mechanism of action relies upon inhibition of calcium ion entrance into smooth muscle cells (calcium-antagonist effect). In humans pinaverium facilitates gastric emptying and decreases intestinal transit time in patients with constipation. Pinaverium is very effective in improving symptoms of irritable bowel syndrome (abdominal pain, gas, diarrhea or constipation). In this respect the drug proved to be significantly superior to placebo, at least as effective as trimebutine and on the whole more active than otilonium and prifinium bromide, being always extremely well tolerated. PMID:8028745

  2. Titration of human-bovine rotavirus reassortants using a tetrazolium-based colorimetric end-point dilution assay.

    PubMed

    DiStefano, D J; Gould, S L; Munshi, S; Robinson, D K

    1995-10-01

    A colorimetric end-point dilution assay was developed for the titration of rotavirus-containing samples that uses commercially available tetrazolium dyes as an indicator of virus infection. This assay offers several advantages over both plaque assays and traditional end-point dilution methods. The latter assays require manual counting of plaques or the scoring of wells for the presence of virus based on observed cytopathic effects. The colorimetric end-point dilution assay enables the scoring of wells based upon absorbance readings alone, thereby eliminating time-consuming and subjective manual screenings. This method also has the potential for automating the analysis of large numbers of samples. Virus titers of human-bovine rotavirus reassortants obtained using this method are comparable to those determined by plaque assay. The scoring of wells based on absorbance readings was also found to agree with manual scoring of cytopathic effects and with the production of viral antigen.

  3. Methyl bromide emissions from tarped fields

    SciTech Connect

    Cicerone, R.J.; Williams, J.; Wang, N.Y.

    1995-12-31

    Once in the stratosphere, bromine atoms can destroy ozone effectively. Because of this potential effect, certain organobromine compounds including methyl bromide (MeBr) are being controlled or eliminated by national and international regulations. It would be valuable to determine the fraction of MeBr used in soil fumigations that subsequently enters the atmosphere to better assess the need for, and value of, strong regulations. We have designed and conducted several experiments accompanying field fumigations with MeBr/chloropicrin mixtures. In each of three field-fumigation experiments new Irvine, CA in which the fumigated field was covered immediately with plastic tarping, we have deployed static flux chambers on top of the tarping and measured escape fluxes of MeBr. After tarp removal, the same chambers were replaced on the bare soil to continue the measurements. We have also measured soil bromide contents before and after the fumigation. One experiment yielded an escape fraction of 80 to 87% (with 19% remaining as bromide) while the other two experiments yielded escape fractions of 30 to 35% (with about 70% remaining as bromide). This paper will summarize stratospheric bromine chemistry, describe the field experiments and discuss factors that influence emissions, including soil pH, moisture and organic content and injection technique. We acknowledge TriCal, Inc. for many helpful discussions and for professional field applications of MeBr.

  4. 77 FR 35295 - Methyl Bromide; Pesticide Tolerances

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-13

    .... Background In the Federal Register of April 6, 2012 (77 FR 20752) (FRL-9345- 1), EPA issued a proposed rule... methyl bromide in or on cotton, undelinted seed under the Federal Food, Drug, and Cosmetic Act (FFDCA... on cotton, undelinted seed at 150 parts per million (ppm). EPA issued a proposed rule that...

  5. Zinc Bromide Waste Solution Treatment Options

    SciTech Connect

    Langston, C.A.

    2001-01-16

    The objective of this effort was to identify treatment options for 20,000 gallons of low-level radioactively contaminated zinc bromide solution currently stored in C-Area. These options will be relevant when the solutions are declared waste.

  6. Can Georgia growers replace methyl bromide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The price and availability of methyl bromide is limiting its use on Georgia farms; the need for an alternative is essential for sustainable vegetable production in GA. Three alternatives were evaluated in on-farm trials in the spring 2007 in Tift, Colquitt and Echols Counties. Treatments were replic...

  7. A comparison of the action of otilonium bromide and pinaverium bromide: study conducted under clinical control.

    PubMed

    Defrance, P; Casini, A

    1991-11-01

    We studied 40 patients with irritable bowel syndrome (IBS) which received in a simple-blind fashion otilonium and pinaverium bromide (15 days each drug). During each 15-day period we evaluated: number of pain episodes, intensity of pain, number of bowel movements, side effects. Otilonium bromide, (OB), compared with pinaverium bromide was able to significantly (p less than 0.05) reduce the number of pain attacks, whereas no significant differences were found between the 2 groups as regards the other parameters. The occurrence of side effects was similar in the two treatment courses. We can conclude that the two types of treatment were similarly useful in IBS, although OB seems more effective than pinaverium bromide. PMID:1756286

  8. Flow injection determination of bromide ion in a developer using bromide ion-selective electrode detector.

    PubMed

    Masadome, T; Asano, Y; Nakamura, T

    1999-10-01

    A potentiometric flow injection determination method for bromide ion in a developer was proposed, by utilizing a flow-through type bromide ion-selective electrode detector. The sensing membrane of the electrode was Ag(2)S-AgBr membrane. The response of the electrode detector as a peak-shape signal was obtained for injected bromide ion in a developer. A linear relationship was found to exist between peak height and the concentration of the bromide ion in a developer in a concentration range from 1.0x10(-3) to 1.0x10(-2) mol l(-1). The relative standard deviation for 10 injections of a 6x10(-3) mol l(-1) bromide ion in a developer was 1.3% and the sampling rate was ca 17-20 samples h(-1). The present method was free from the interference of an organic reducing reagent, an organic substance in a developer sample solution for the determination of bromide ion in a developer.

  9. 21 CFR 522.275 - N-Butylscopolammonium bromide.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false N-Butylscopolammonium bromide. 522.275 Section 522....275 N-Butylscopolammonium bromide. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) N-butylscopolammonium bromide. (b) Sponsor. See No. 000010 in § 510.600(c) of this...

  10. 21 CFR 522.275 - N-Butylscopolammonium bromide.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false N-Butylscopolammonium bromide. 522.275 Section 522....275 N-Butylscopolammonium bromide. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) N-butylscopolammonium bromide. (b) Sponsor. See No. 000010 in § 510.600(c) of this...

  11. 40 CFR 180.124 - Methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Methyl bromide; tolerances for... § 180.124 Methyl bromide; tolerances for residues. (a) General. A tolerance is established for residues of the fumigant methyl bromide, including metabolites and degradates, in or on the commodity in...

  12. 21 CFR 522.275 - N-Butylscopolammonium bromide.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false N-Butylscopolammonium bromide. 522.275 Section 522....275 N-Butylscopolammonium bromide. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) N-butylscopolammonium bromide. (b) Sponsor. See No. 000010 in § 510.600(c) of this...

  13. 21 CFR 522.275 - N-Butylscopolammonium bromide.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false N-Butylscopolammonium bromide. 522.275 Section 522....275 N-Butylscopolammonium bromide. (a) Specifications. Each milliliter of solution contains 20 milligrams (mg) N-butylscopolammonium bromide. (b) Sponsor. See No. 000010 in § 510.600(c) of this...

  14. Toxic effects on bacterial metabolism of the redox dye 5-cyano-2,3-ditolyl tetrazolium chloride.

    PubMed

    Ullrich, S; Karrasch, B; Hoppe, H; Jeskulke, K; Mehrens, M

    1996-12-01

    The monotetrazolium redox dye 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) has been used as a vital stain of actively respiring bacteria for several years. In this study, inhibitory effects on bacterial metabolism of this redox dye have been examined in a brackish water environment (Kiel Fjord, Germany) and a freshwater environment (Elbe River, Germany). As the results from time series experiments (1 to 10 h) show, bacterial growth and respiration of the investigated natural communities were clearly reduced by CTC supply. Compared with untreated controls (100%), CTC-treated samples showed distinctly lower heterotrophic bacterial plate counts (0 to 24 and 11.8 to 23.7%, respectively), bacterial production (0.9 to 14.1 and 1.1 to 9.6%, respectively), bacterial respiration (4.1 to 9.4 and 6.8 to 43.8% for several concentrations of (sup14)C-labeled glucose), and [(sup14)C]glucose incorporation (0.2 to 4.2%). Additionally, toxicity of CTC was demonstrated by luminescence in a Microtox bioassay. CTC concentrations of 0.1 and 5.0 (mu)M required only 15 min for decreases of approximately 50 and 100%, respectively. The suppression of CTC on several bacterial metabolic processes suggests that determination by the CTC technique underestimates the actual number of active cells distinctly. This conclusion is confirmed by the comparison of generation times calculated on the basis of thymidine uptake data and active bacterial counts determined by the CTC assay and microautoradiography. While unrealistic short generation times (0.5 to 5 h) resulted from the CTC assay, the generation times calculated according to microautoradiography ranged within values (7 to 21 h) reported elsewhere for comparable aquatic environments. The inhibitory effect of CTC demonstrated in our experiments is an aspect with regard to the application of this tetrazolium dye for the estimation of active bacteria in natural aquatic environments which hitherto has not been considered. PMID:16535471

  15. Measurements of atmospheric methyl bromide and bromoform

    SciTech Connect

    Cicerone, R.J.; Heidt, L.E.; Pollock, W.H.

    1988-04-20

    We have measured gaseous methyl bromide (CH/sub 3/Br) and bromoform (CHBr/sub 3/) in air samples that were gathered approximately weekly from five ground-level sites: Point Barrow, Alaska; Mauna Loa Observatory and Cape Kumukahi, Hawaii; Matatula, Samoa; and Kaitorete Spit, New Zealand. Approximately 750 samples have been analyzed for CH/sub 3/Br between January 1985 and October 1987 and 990 samples have been analyzed for CHBr/sub 3/ between early 1984 and September 1987, all by gas chromatography/mass spectroscopy. Methyl bromide concentrations are typically 10--11 parts per trillion (ppt) by volume; there are no clear indications of temporal increases. Bromoform concentrations are typically 2--3 ppt, but large seasonal variations are seen at Point Barrow. copyright American Geophysical Union 1988

  16. Methyl bromide users search for science

    SciTech Connect

    Winegar, E.D.

    1995-01-01

    Workers, neighbors and the ozone are protected by regulation from this chemical, but those needing it complain that a solid foundation is lacking for the rules. Although not yet featured on {open_quotes}60 Minutes,{close_quotes} the pesticide methyl bromide is gaining widespread attention because of its central position in debates about worker health and safety, environmental toxics exposure and global ozone depletion.

  17. Removal of bromide and natural organic matter by anion exchange.

    PubMed

    Hsu, Susan; Singer, Philip C

    2010-04-01

    Bromide removal by anion exchange was explored for various water qualities, process configurations, and resin characteristics. Simulated natural waters containing different amounts of natural organic matter (NOM), bicarbonate, chloride, and bromide were treated with a polyacrylate-based magnetic ion exchange (MIEX) resin on a batch basis to evaluate the effectiveness of the resin for removal of bromide. While bromide removal was achieved to some degree, alkalinity (bicarbonate), dissolved organic carbon (DOC), and chloride were shown to inhibit bromide removal in waters with bromide concentrations of 100 and 300 microg/L. Water was also treated using a two-stage batch MIEX process. Two-stage treatment resulted in only a slight improvement in bromide removal compared to single-stage treatment, presumably due to competition with the high concentration of chloride which is present along with bromide in natural waters. In view of the relatively poor bromide removal results for the MIEX resin, a limited set of experiments was performed using polystyrene resins. DOC and bromide removal were compared by treating model waters with MIEX and two polystyrene resins, Ionac A-641 and Amberlite IRA910. The two polystyrene resins were seen to be more effective for bromide removal, while the MIEX resin was more effective at removing DOC.

  18. Indium-111-antimyosin images compared with triphenyl tetrazolium chloride staining in a patient six days after myocardial infarction

    SciTech Connect

    Jain, D.; Crawley, J.C.; Lahiri, A.; Raftery, E.B. )

    1990-02-01

    The results of indium-111 ({sup 111}In) antimyosin imaging during life and the findings on postmortem imaging and triphenyl tetrazolium chloride (TTC) staining of the heart are reported from a patient who received {sup 111}In-antimyosin on the sixth day following myocardial infarction and died after imaging the next day. The planar images obtained during life showed abnormal {sup 111}In-antimyosin uptake in the posterior, lateral, and apical walls of the left ventricle. Autopsy revealed extensive infarction of the left ventricular lateral and posterior walls with cardiac rupture, which was the cause of sudden death. Direct imaging of the sliced specimen of heart revealed abnormal tracer uptake in the lateral and posterior walls of the left ventricle, which correlated closely with the area of necrosis outlined by TTC staining. Our results confirm the experimental findings that antimyosin antibody binds specifically to the acute irreversibly damaged myocardial cells. A high degree of tracer uptake can be seen even when {sup 111}In-antimyosin is injected six days postinfarction.

  19. Development of an enzymatic chromatography strip with nicotinamide adenine dinucleotide-tetrazolium coupling reactions for quantitative l-lactate analysis.

    PubMed

    Kan, Shu-Chen; Chang, Wei-Feng; Lan, Min-Chi; Lin, Chia-Chi; Lai, Wei-Shiang; Shieh, Chwen-Jen; Hsiung, Kuang-Pin; Liu, Yung-Chuan

    2015-02-15

    In this study, a dry assay of l-lactate via the enzymatic chromatographic test (ECT) was developed. An l-lactate dehydrogenase plus a nicotinamide adenine dinucleotide (NADH) regeneration reaction were applied simultaneously. Various tetrazolium salts were screened to reveal visible color intensities capable of determining the lactate concentrations in the sample. The optimal analysis conditions were as follows. The diaphorase (0.5 μl, 2(-6)U/μl) was immobilized in the test line of the ECT strip. Nitrotetrazolium blue chloride (5 μl, 12 mM), l-lactate dehydrogenase (1 μl, 0.25U/μl), and NAD(+) (2μl, 1.5×10(-5)M) were added into the mobile phase (100 μl) composed of 0.1% (w/w) Tween 20 in 10mM phosphate buffer (pH 9.0), and the process was left to run for 10 min. This detection had a linear range of 0.039 to 5mM with a detection limit of 0.047 mM. This quantitative analysis process for l-lactate was easy to operate with good stability and was proper for the point-of-care testing applications. PMID:25454507

  20. Investigations of riboflavin photolysis via coloured light in the nitro blue tetrazolium assay for superoxide dismutase activity.

    PubMed

    Cheng, Chien-wei; Chen, Liang-yü; Chou, Chan-wei; Liang, Ji-yuan

    2015-07-01

    Determination of the superoxide dismutase activity is an important issue in the fields of biochemistry and the medical sciences. In the riboflavin/nitro blue tetrazolium (B2/NBT) method, the light sources used for generating superoxide anion radicals from light-excited riboflavin are normally fluorescent lamps. However, the conditions of B2/NBT experiments vary. This study investigated the effect of the light source on the light-excitation of riboflavin. The effectiveness of the photolysis was controlled by the wavelength of the light source. The spectra of fluorescent lamps are composed of multiple colour lights, and the emission spectra of fluorescent lamps made by different manufacturers may vary. Blue light was determined to be the most efficient for the photochemical reaction of riboflavin in visible region. The quality of the blue light in fluorescent lamps is critical to the photo-decomposition of riboflavin. A blue light is better than a fluorescent lamp for the photo-decomposition of riboflavin. The performance of the B2/NBT method is thereby optimized.

  1. [Research advances in methyl bromide in the ocean].

    PubMed

    Du, Hui-na; Xie, Wen-xia; Cui, Yu-qian; Chen, Jian-lei; Ye, Si-yuan

    2014-12-01

    Methyl bromide is an important atmospheric trace gas, which plays significant roles in the global warming and atmospheric chemistry. The ocean plays important and complex roles in the global biogeochemical cycles of methyl bromide, not only the source of atmospheric methyl bromide, but also the sink. Therefore, developing the chemical research of the soluble methyl bromide in the ocean, will not only have a certain guiding significance to the atmospheric ozone layer protection, but also provide a theoretical basis for estimating methyl bromide's contribution to the global environmental change on global scale. This paper reviewed the research advances on methyl bromide in the ocean, from the aspects of the biogeochemical cycle of methyl bromide in the ocean, the analysis and determination method, the concentration distribution, the sea-to-air flux and its sources and sinks in the atmosphere. Some deficiencies in the current studies were put forward, and the directions of the future studies were prospected. PMID:25876424

  2. [Research advances in methyl bromide in the ocean].

    PubMed

    Du, Hui-na; Xie, Wen-xia; Cui, Yu-qian; Chen, Jian-lei; Ye, Si-yuan

    2014-12-01

    Methyl bromide is an important atmospheric trace gas, which plays significant roles in the global warming and atmospheric chemistry. The ocean plays important and complex roles in the global biogeochemical cycles of methyl bromide, not only the source of atmospheric methyl bromide, but also the sink. Therefore, developing the chemical research of the soluble methyl bromide in the ocean, will not only have a certain guiding significance to the atmospheric ozone layer protection, but also provide a theoretical basis for estimating methyl bromide's contribution to the global environmental change on global scale. This paper reviewed the research advances on methyl bromide in the ocean, from the aspects of the biogeochemical cycle of methyl bromide in the ocean, the analysis and determination method, the concentration distribution, the sea-to-air flux and its sources and sinks in the atmosphere. Some deficiencies in the current studies were put forward, and the directions of the future studies were prospected.

  3. Methyl bromide: Ocean sources, ocean sinks, and climate sensitivity

    SciTech Connect

    Anbar, A.D.; Yung, Y.L.; Chavez, F.P.

    1996-03-01

    This study was performed to examine conflicting conclusions of two previously published studies which estimated the size of oceanic sources of methyl bromide. In addition, the sensitivity of atmospheric methyl bromide to climatic variations was examined. A steady state mass balance model was used to reexamine data from the previous studies. Linear scaling of methyl bromide production rates to chlorophyll content provided agreement between the two models. The results suggest that the open ocean is a small net sink for atmospheric methyl bromide, rather than a large net source. A high rate of biological production of methyl bromide in seawater is also strongly indicated. A coupled ocean-atmosphere model indicated that methyl bromide variations induced by climatic change can be larger than those resulting from 25% variations in anthropogenic sources. Quantifying marine production rates of methyl bromide is suggested as a necessary step in assessing stratospheric ozone loss. 63 refs., 10 figs., 2 tabs.

  4. Methyl bromide volatility measurements from treated fields

    SciTech Connect

    Majewski, M.S.; Woodrow, J.E.; Seiber, J.N. |

    1995-12-31

    Methyl bromide is used as an agricultural soil fumigant and concern is growing over the role it may play in the depletion of stratospheric ozone. Methyl bromide is applied using various techniques and little is known about how much of the applied fumigant volatilizes into the atmosphere after application. The post-application volatilization losses of methyl bromide from two fields using different application practices were measured using an aerodynamic-gradient technique. One field was covered with a high-barrier plastic film tarp during application and the other was left uncovered, but the furrows made by the injection shanks were bedded over. The cumulative volatilization losses from the tarped field were 22% of the nominal application within the first 5 days of the experiment and about 32% of the nominal application within 9 days including the one day after the tarp was removed on day 8. The nontarped field lost 89%of the nominal application by volatilization in 5 days. The error associated, with each flux measurement, as well as variations in daily flux losses with differing sampling period lengths show the degree of variability inherent in this type of study.

  5. Methyl bromide fate in fumigated soils

    SciTech Connect

    Anderson, T.A.; Rice, P.J.; Cink, J.H.

    1995-12-31

    Although widespread use of methyl bromide (MeBr) as a sail and structure fumigant has previously been recognized as a potential significant source of atmospheric MeBr, losses have not been well quantified. Our research indicates that, in laboratory studies, MeBr is volatilized rapidly from fumigated soils and that volatility increases with temperature (35{degrees}C > 25{degrees}C and 15{degrees}C) and moisture (0.03 bar and 0.3 bar > 1 bar > 3 bar). Degradation of MeBr in soil, as indicated by production of bromide ion, was also directly related to temperature and moisture. Most of the soil degradation of MeBr in these studies appears to be abiotic based on the observation of toxicity (reduced microbial respiration) in fumigated soils. We also determined the transformation and movement of MeBr in undisturbed soil columns. These studies also indicated that MeBT volatilizes rapidly (> 50% in 48 h) from soil. In addition, MeBr was not detected in the leachate from the soil columns, however, bromide ion was detected at levels above background 48 h after fumigation and peaked at 5 weeks.

  6. Europium-doped barium bromide iodide

    SciTech Connect

    Gundiah, Gautam; Hanrahan, Stephen M.; Hollander, Fredrick J.; Bourret-Courchesne, Edith D.

    2009-10-21

    Single crystals of Ba0.96Eu0.04BrI (barium europium bromide iodide) were grown by the Bridgman technique. The title compound adopts the ordered PbCl2 structure [Braekken (1932). Z. Kristallogr. 83, 222-282]. All atoms occupy the fourfold special positions (4c, site symmetry m) of the space group Pnma with a statistical distribution of Ba and Eu. They lie on the mirror planes, perpendicular to the b axis at y = +-0.25. Each cation is coordinated by nine anions in a tricapped trigonal prismatic arrangement.

  7. Advanced hydrogen electrode for hydrogen-bromide battery

    NASA Technical Reports Server (NTRS)

    Kosek, Jack A.; Laconti, Anthony B.

    1987-01-01

    Binary platinum alloys are being developed as hydrogen electrocatalysts for use in a hydrogen bromide battery system. These alloys were varied in terms of alloy component mole ratio and heat treatment temperature. Electrocatalyst evaluation, performed in the absence and presence of bromide ion, includes floating half cell polarization studies, electrochemical surface area measurements, X ray diffraction analysis, scanning electron microscopy analysis and corrosion measurements. Results obtained to date indicate a platinum rich alloy has the best tolerance to bromide ion poisoning.

  8. Mono-sulfonated tetrazolium salt based NAD(P)H detection reagents suitable for dehydrogenase and real-time cell viability assays.

    PubMed

    Zhang, Wei; Zhu, Min; Wang, Feng; Cao, Danhui; Ruan, Jennifer Jin; Su, Weike; Ruan, Benfang Helen

    2016-09-15

    Glutamate dehydrogenase (GDH) catalyzes the oxidative deamination of L-glutamate and is important for several biological processes. For GDH inhibitor screening, we developed a novel mono-sulfonated tetrazolium salt (EZMTT), which can be synthesized using H2O2 oxidation and purified easily on silica gel in large quantities. The EZMTT detection method showed linear dose responses to NAD(P)H, dehydrogenase concentration and cell numbers. In E. coli GDH assay, the EZMTT method showed excellent assay reproducibility with a Z factor of 0.9 and caused no false positives in the presence of antioxidants (such as BME). Using the EZMTT-formazan-NAD(P)H system, we showed that EGCG is a potent E. coli GDH inhibitor (IC50 45 nM) and identified that Ebselen, a multifunctional thioredoxin reductase inhibitor, inactivated E. coli GDH (IC50 213 nM). In cell-based assays at 0.5 mM tetrazolium concentration, EZMTT showed essentially no toxicity after a 3-day incubation, whereas 40% of inhibition was observed for WST-8. In conclusion, EZMTT is a novel tetrazolium salt which provides improved features that are suitable for dehydrogenases and real-time cell-based high-throughput screening (HTS). PMID:27387057

  9. A reliable non-separation fluorescence quenching assay for total glycated serum protein: a simple alternative to nitroblue tetrazolium reduction.

    PubMed

    Blincko, S; Colbert, D; John, W G; Edwards, R

    2000-05-01

    A simple non-separation assay for the measurement of total glycated serum protein is described. It was found that the fluorescence intensity of a solution of a fluorescein-boronic acid derivative was quenched in proportion to the amount of serum added. This led to the development of an assay in which 10 microL of serum is added to 4 mL of a solution of the fluorescein-boronic acid derivative and the fluorescence intensity is measured after 15 min. The results, as measured by drop in fluorescence intensity, calibrated by a single standard, were compared with the results for nitroblue tetrazolium (NBT) reduction of fructosamine and showed good correlation (r=0.936, n=114). The intra-assay precision (seven samples each measured 10 times) was less than 2.1% (concentration range 190-660 micromol/L); inter-assay precision for seven samples in 10 assays was less than 2.5% (over the same concentration range). Dilution of serum that had a high concentration of total glycated protein showed the assay to be linear. Serum samples (with low, medium and high total glycated protein concentrations) showed less than 2.1% difference from base results with added glucose (up to 60 mmol/L), less than 9.7% difference with added bilirubin (up to 250 micromol/L) and less than 6.9% with added triglycerides (up to 50 mmol/L). Addition of haemoglobin (up to 0.9 g/dL) with high glycation (11.7% HbA1c) to plasma (298 micromol/L total glycated protein) showed less than 10% difference from the base result. Assays performed over a range of temperatures (12-34 degrees C) showed no significant differences in the results. The assay gives similar results to the currently used NTB method but with significantly less susceptibility to interferences. As such the method should be a useful aid in the management of diabetes. PMID:10817254

  10. An Ill Wind: Methyl Bromide Use Near California Schools, 1998.

    ERIC Educational Resources Information Center

    Ross, Zev; Walker, Bill

    A California study investigates the use of the toxic pesticide methyl bromide near the state's public schools, explains why proposed safety rules have failed to protect children and others from exposure, and examines regions at particular exposure risk. Study results show an increasing exposure to methyl bromide near schools already at risk while…

  11. 40 CFR 180.124 - Methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Methyl bromide; tolerances for residues. 180.124 Section 180.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.124 Methyl bromide; tolerances...

  12. 40 CFR 180.124 - Methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Methyl bromide; tolerances for residues. 180.124 Section 180.124 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS TOLERANCES AND EXEMPTIONS FOR PESTICIDE CHEMICAL RESIDUES IN FOOD Specific Tolerances § 180.124 Methyl bromide; tolerances...

  13. Degradation of methyl bromide in anaerobic sediments

    USGS Publications Warehouse

    Oremland, R.S.; Miller, L.G.; Strohmaler, F.E.

    1994-01-01

    Methyl bromide (MeBr) was anaerobically degraded in saltmarsh sediments after reaction with sulfide. The product of this nucleophilic substitution reaction was methanethiol, which underwent further chemical and bacterial reactions to form dimethyl sulfide. These two gases appeared transiently during sediment incubations because they were metabolized by methanogenic and sulfate-reducing bacteria. A second, less significant reaction of MeBr was the exchange with chloride, forming methyl chloride, which was also susceptible to attack by sulfide. Incubation of 14C-labeled methyl iodide as an analogue of MeBr resulted in the formation of 14CH4 and 14CO2 and also indicated that sulfate-reducing bacteria as well as methanogens metabolized the methylated sulfur intermediates. These results suggest that exposed sediments with abundant free sulfide, such as coastal salt-marshes, may constitute a sink for atmospheric MeBr.

  14. Single ion dynamics in molten sodium bromide

    SciTech Connect

    Alcaraz, O.; Trullas, J.; Demmel, F.

    2014-12-28

    We present a study on the single ion dynamics in the molten alkali halide NaBr. Quasielastic neutron scattering was employed to extract the self-diffusion coefficient of the sodium ions at three temperatures. Molecular dynamics simulations using rigid and polarizable ion models have been performed in parallel to extract the sodium and bromide single dynamics and ionic conductivities. Two methods have been employed to derive the ion diffusion, calculating the mean squared displacements and the velocity autocorrelation functions, as well as analysing the increase of the line widths of the self-dynamic structure factors. The sodium diffusion coefficients show a remarkable good agreement between experiment and simulation utilising the polarisable potential.

  15. A new methyl bromide gas generator for inhalation toxicity studies.

    PubMed

    Hori, H; Hyakudo, T; Tanaka, I

    1992-09-01

    A simple generator for methyl bromide gas has been newly developed by us. For inhalation toxicity studies, until now, there have been few generators capable of producing a constant and stable concentration of methyl bromide gas easily because of its high volatility. The principle of this new generator is based on gas-liquid equilibrium. The gas is generated from the surface of liquid methyl bromide in an evaporator made of a Teflon tube. The generator can produce up to 10,000 ppm of methyl bromide gas in a 0.1 m3 exposure chamber, and the concentration of this generated gas is able to be kept within +/- 0.8% over a long period of time. The generator has proved to be useful for investigating the effects of methyl bromide on health in inhalation toxicity studies.

  16. Atmosphere-plant canopy interactions of methyl bromide

    SciTech Connect

    Taylor, G.E. Jr.; Leonard, T.D.; Gustin, M.S.

    1995-12-31

    In the planetary boundary layer, parcels of air containing background and elevated concentrations of methyl bromide commonly pass through plant canopies in managed (agriculture) and natural (forests, grasslands) ecosystems. It is hypothesized that leaf surfaces are a significant sink or methyl bromide on a local and regional scale and that failure to account for this sink results in a significant overestimation of methyl bromide transport to the stratosphere. Using highly controlled environments, studies are investigating the reactivity of leaf surfaces for methyl bromide at elevated and global background concentrations. Estimates of pathway resistances are being calculated and sites of deposition determined. The results indicate that plant canopies are a significant unrecognized sink for methyl bromide in the atmosphere.

  17. Indirect spectrophotometric determination of traces of bromide in water

    USGS Publications Warehouse

    Fishman, M. J.; Skougstad, M.W.

    1963-01-01

    A rapid, accurate, and sensitive indirect spectrophotometric method for the determination of bromide in natural waters is based on the catalytic effect of bromide on the oxidation of iodine to iodate by potassium permanganate in sulfuric acid solution. The method is applicable to concentrations ranging from 1 to 100 ??g. of bromide per liter, but may be modified to extend the concentration range. Most ions commonly occurring in water do not interfere. The standard deviation is 2.9 at bromide concentrations of 100 ??g. per liter and less at lower concentrations. The determination of bromide in samples containing known added amounts gave values ranging from 99 to 105% of the concentration calculated to be present.

  18. Selective oxidation of bromide in wastewater brines from hydraulic fracturing.

    PubMed

    Sun, Mei; Lowry, Gregory V; Gregory, Kelvin B

    2013-07-01

    Brines generated from oil and natural gas production, including flowback water and produced water from hydraulic fracturing of shale gas, may contain elevated concentrations of bromide (~1 g/L). Bromide is a broad concern due to the potential for forming brominated disinfection byproducts (DBPs) during drinking water treatment. Conventional treatment processes for bromide removal is costly and not specific. Selective bromide removal is technically challenging due to the presence of other ions in the brine, especially chloride as high as 30-200 g/L. This study evaluates the ability of solid graphite electrodes to selectively oxidize bromide to bromine in flowback water and produced water from a shale gas operation in Southwestern PA. The bromine can then be outgassed from the solution and recovered, as a process well understood in the bromine industry. This study revealed that bromide may be selectively and rapidly removed from oil and gas brines (~10 h(-1) m(-2) for produced water and ~60 h(-1) m(-2) for flowback water). The electrolysis occurs with a current efficiency between 60 and 90%, and the estimated energy cost is ~6 kJ/g Br. These data are similar to those for the chlor-alkali process that is commonly used for chlorine gas and sodium hydroxide production. The results demonstrate that bromide may be selectively removed from oil and gas brines to create an opportunity for environmental protection and resource recovery.

  19. Chloride, bromide and iodide scintillators with europium

    DOEpatents

    Zhuravleva, Mariya; Yang, Kan

    2016-09-27

    A halide scintillator material is disclosed where the halide may comprise chloride, bromide or iodide. The material is single-crystalline and has a composition of the general formula ABX.sub.3 where A is an alkali, B is an alkali earth and X is a halide which general composition was investigated. In particular, crystals of the formula ACa.sub.1-yEu.sub.yI.sub.3 where A=K, Rb and Cs were formed as well as crystals of the formula CsA.sub.1-yEu.sub.yX.sub.3 (where A=Ca, Sr, Ba, or a combination thereof and X=Cl, Br or I or a combination thereof) with divalent Europium doping where 0.ltoreq.y.ltoreq.1, and more particularly Eu doping has been studied at one to ten mol %. The disclosed scintillator materials are suitable for making scintillation detectors used in applications such as medical imaging and homeland security.

  20. Distinction of Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts with a selection medium.

    PubMed

    Tsukatani, Tadayuki; Suenaga, Hikaru; Higuchi, Tomoko; Shiga, Masanobu; Noguchi, Katsuya; Matsumoto, Kiyoshi

    2011-01-01

    Bacteria are fundamentally divided into two groups: Gram-positive and Gram-negative. Although the Gram stain and other techniques can be used to differentiate these groups, some issues exist with traditional approaches. In this study, we developed a method for differentiating Gram-positive and -negative bacteria using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt} (WST-8) via 2-methyl-1,4-napthoquinone with a selection medium. We optimized the composition of the selection medium to allow the growth of Gram-negative bacteria while inhibiting the growth of Gram-positive bacteria. When the colorimetric viability assay was carried out in a selection medium containing 0.5µg/ml crystal violet, 5.0 µg/ml daptomycin, and 5.0µg/ml vancomycin, the reduction in WST-8 by Gram-positive bacteria was inhibited. On the other hand, Gram-negative bacteria produced WST-8-formazan in the selection medium. The proposed method was also applied to determine the Gram staining characteristics of bacteria isolated from various foodstuffs. There was good agreement between the results obtained using the present method and those obtained using a conventional staining method. These results suggest that the WST-8 colorimetric assay with selection medium is a useful technique for accurately differentiating Gram-positive and -negative bacteria.

  1. Health and Environmental Effects Profile for methyl bromide

    SciTech Connect

    Not Available

    1986-06-01

    The Health and Environmental Effects Profile for methyl bromide was prepared to support listings of hazardous constituents of a wide range of waste streams under Section 3001 of the Resource Conservation and Recovery Act (RCRA) and to provide health-related limits for emergency actions under Section 101 of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). Both published literature and information obtained from Agency program office files were evaluated as they pertained to potential human health, aquatic life, and environmental effects. Quantitative estimates are presented provided sufficient data are available. Methyl bromide has been determined to be a systemic toxicant. An Acceptable Daily Intake (ADI), for methyl bromide is 0.0014 mg/kg/day for oral exposure. The Reportable Quantity (RQ) value for methyl bromide is 100.

  2. Methyl bromide as a microbicidal fumigant for tree nuts.

    PubMed Central

    Schade, J E; King, A D

    1977-01-01

    Methyl bromide (MeBr) has broad microbicidal activity, but its use as a disinfectant for food is limited by the resulting bromide residues. Increasing the MeBr concentration, exposure temperature, or exposure period of a treatment tended to increase both the microbicidal efficacy of MeBr and the bromide residues. Its sporicidal activity was less at high than at low relative humidity within the range of 20 to 99%. Both the efficacy and the resulting residues of a MeBr treatment varied inversely with the load of product in a fumigation chamber due to sorption of the fumigant. Fumigation tests with almond kernels inoculated with Escherichia coli or Salmonella typhimurium indicated that MeBr can be used to disinfect whole nut kernels without resulting in excessive bromide residues, although the MeBr level necessary is higher than that normally used for insect control. PMID:406844

  3. 7 CFR 305.6 - Methyl bromide fumigation treatment schedules.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., fumigation with methyl bromide for sapote fruit fly. Regulated citrus fruits originating inside an area quarantined for sapote fruit fly that are to be moved outside the quarantined area may be treated with...

  4. The oceans: A source or a sink of methyl bromide?

    SciTech Connect

    Pilinis, C.; King, D.B.; Saltzman, E.S.

    1996-04-15

    The global ocean/atmosphere flux of methyl bromide has been estimated from shipboard measurements of the saturation anomaly. When such data are extrapolated globally on the basis of constant saturation anomaly, the ocean is a net sink for methyl bromide [Lobert et al.]. The same data can also be extrapolated on the basis of steady-state production rate of methyl bromide in the water column, allowing regional and seasonal variations in temperature to affect the saturation anomaly. The authors have carried out this type of extrapolation, and they found that the oceans are a strong net source of methyl bromide to the atmosphere. The difference arises mainly due to slow degradation rates in water of higher latitudes. A reduction of the applied production rate by more than 35% is needed in order to switch the ocean from a source to a sink of methyl bromide. These results demonstrate the sensitivity of current estimates of oceanic flux to assumptions about methyl bromide production and destruction in the water column. 19 refs., 2 fig.

  5. Surface and bulk properties of aqueous decyltrimethylammonium bromide-hexadecyltrimethylammonium bromide mixed system.

    PubMed

    Rodríguez, J L; Sierra, M B; Messina, P V; Morini, M A; Schulz, P C; Del Burgo, P; Junquera, E; Rodríguez, A; Aicart, E

    2007-10-15

    The aqueous mixed system decyltrimethylammonium bromide (C(10)TAB)-hexadecyltrimethylammonium bromide (C(16)TAB) was studied by conductivity, ion-selective electrodes, surface tension, and fluorescence spectroscopy techniques. The mixture critical micelle concentration, cmc(*), aggregation number, N( *), and micelle molar conductivity, Lambda(M)(cmc), showed that the system aggregation is strongly nonideal. Both cmc(*) and N( *) results were analyzed with two different procedures: (i) the regular solution theory on mixed micelles or Rubingh's theory, and (ii) by the determination of the partial critical micelle concentration of the amphiphile component i in the presence of a constant concentration of the other amphiphile component, cmc(i)( *). The Rubingh procedure gives micelles richer in C(16)TAB than the overall mixtures, while procedure (ii) gives micelles having the same composition as in the complete surfactant mixture (alpha(C(10)TAB). Mixed micelles are larger than pure surfactant ones, with nonspherical shape. Using a literature model, the cause of the synergistic effect seems to be a reduction of the hydrocarbon/water contact at the micelle surface when mixed micelles form. Conductivity and ion-selective electrodes indicate that highly ionized premicelles form immediately before the cmc(*). The air/solution interface is strongly nonideal and much richer in C(16)TAB than the composition in the bulk. When micelles form there is a strong desorption from the air/solution interface because micelles are energetically favored when compared with the monolayer.

  6. Bromide therapy in refractory canine idiopathic epilepsy.

    PubMed

    Podell, M; Fenner, W R

    1993-01-01

    On a retrospective basis, the response to adding chronic oral bromide (BR) to phenobarbital (PB) administration in 23 refractory canine idiopathic epileptics between 1986 and 1991 was studied. The mean age for an observed first seizure was 24 months (range 7 to 72) for all dogs. Thirteen (57%) dogs were males with no breed predisposition observed. All dogs were diagnosed as having idiopathic epilepsy based on normal metabolic and neurologic diagnostic evaluations. Dogs were evaluated before BR therapy for a mean time of 22 months (range 5 to 75 months). Seventeen dogs (74%) received multiple antiepileptic drugs (AEDs) before BR therapy. All animals were maintained on PB at least 4 months before the onset of BR therapy, with a mean trough serum concentration of 37.8 mcg/mL and no improvement in seizure severity or recurrence. Twelve dogs presented with generalized isolated seizures and 11 with generalized cluster seizures (two or more seizures within 24 hours) as their first seizure. The effects of BR therapy were evaluated for a mean time of 15 months (range 4 to 33), with 17 dogs (74%) followed for 12 or more months. The mean BR serum concentration for the 0 to 4 months time period was 117 mg/dL compared with 161 mg/dL for the greater than 4 months period. Overall, response to BR therapy was associated with a reduction in the total number of seizures in 83% of the dogs when compared with their respective pre-BR period. For those followed for 1 year after BR, there was a 53% reduction in the number of seizures compared with the previous 12 months. Furthermore, owners reported a decrease in seizure intensity (65% of dogs) and change to a less severe seizure type (22% of dogs) in those dogs that continued to have seizures. Seizure-free status was obtained in 26% of the dogs with protection continuing up to 31 months in one dog. No correlations could be determined between response to BR and either age of onset of the first seizure or interval from the first AED

  7. Disposition of ( UC)methyl bromide in rats after inhalation

    SciTech Connect

    Bond, J.A.; Dutcher, J.S.; Medinsky, M.A.; Henderson, R.F.; Birnbaum, L.S.

    1985-01-01

    The purpose of this investigation was to determine the disposition and metabolism of ( UC)methyl bromide in rats after inhalation. Male Fischer-344 rats were exposed nose only to a vapor concentration of 337 nmol ( UC)methyl bromide/liter air (9.0 ppm, 25C, 620 torr) for 6 hr. Urine, feces, expired air, and tissues were collected for up to 65 hr after exposure. Elimination of UC as UCO2 was the major route of excretion with about 47% (3900 nmol/rat) of the total ( UC)methyl bromide absorbed excreted by this route. CO2 excretion exhibited a biphasic elimination pattern with 85% of the UCO2 being excreted with a half-time of 3.9 +/- 0.1 hr (anti x +/- SE) and 15% excreted with a half-time of 11.4 +/- 0.2 hr. Half-times for elimination of UC in urine and feces were 9.6 +/- 0.1 and 16.1 +/- 0.1 hr, respectively. By 65 hr after exposure, about 75% of the initial radioactivity had been excreted with 25% remaining in the body. Radioactivity was widely distributed in tissues immediately following exposure with lung (250 nmol equivalents/g), adrenal (240 nmol equivalents/g), and nasal turbinates (110 nmol equivalents/g) containing the highest concentrations of UC. Radioactivity in livers immediately after exposure accounted for about 17% of the absorbed methyl bromide. Radioactivity in all other tissues examined accounted for about 10% of the absorbed methyl bromide. Elimination half-times of UC from tissues were on the order of 1.5 to 8 hr. In all tissues examined, over 90% of the UC in the tissues was methyl bromide metabolities. The data from this study indicate that after inhalation methyl bromide is rapidly metabolized in tissues and readily excreted. 22 references, 4 figures, 4 tables.

  8. UV photodissociation of methyl bromide and methyl bromide cation studied by velocity map imaging

    SciTech Connect

    Blanchet, Valerie; Samartzis, Peter C.; Wodtke, Alec M.

    2009-01-21

    We employ the velocity map imaging technique to measure kinetic energy and angular distributions of state selected CH{sub 3} (v{sub 2}=0,1,2,3) and Br ({sup 2}P{sub 3/2}, {sup 2}P{sub 1/2}) photofragments produced by methyl bromide photolysis at 215.9 nm. These results show unambiguously that the Br and Br* forming channels result in different vibrational excitations of the umbrella mode of the methyl fragment. Low energy structured features appear on the images, which arise from CH{sub 3}Br{sup +} photodissociation near 330 nm. The excess energy of the probe laser photon is channeled into CH{sub 3}{sup +} vibrational excitation, most probably in the {nu}{sub 4} degenerate bend.

  9. NAD(P)H nitroblue tetrazolium reductase levels in apparently normoxic tissues: a histochemical study correlating enzyme activity with binding of radiolabelled misonidazole.

    PubMed

    Cobb, L M; Hacker, T; Nolan, J

    1990-04-01

    Hack and Helmy's method for the histochemical identification of NAD(P)H nitroblue tetrazolium reductase activity was employed to pinpoint reductase activity in certain cells in the mouse. High activity was observed in the following: lower airway epithelium, liver (centrilobular zone), eyelid (meibomian and sebaceous glands), vulval gland and parotid gland (striated cells of intralobular ducts). All of these cells had previously been identified as sites of binding of the reactive metabolites formed from the enzymic reduction of misonidazole (MISO) (Cobb et al., 1989). It had previously been thought that MISO binding would only take place in significant amounts in hypoxic tissues (tumour and possibly liver) since in normoxic tissues oxygen should reverse the initial one electron enzymic reduction, thus preventing progressive reduction to reactive species. We suggest that the very high levels of reductase in the above listed, probably normoxic, tissues contribute significantly to the accumulation of bound reactive MISO metabolite(s).

  10. Zinc Bromide Combustion: Implications for the Consolidated Incinerator Facility

    SciTech Connect

    Oji, L.N.

    1998-12-16

    In the nuclear industry, zinc bromide (ZnBr2) is used for radiation shielding. At Savannah River Site (SRS) zinc bromide solution, in appropriate configurations and housings, was used mainly for shielding in viewing windows in nuclear reactor and separation areas. Waste stream feeds that will be incinerated at the CIF will occasionally include zinc bromide solution/gel matrices.The CIF air pollution systems control uses a water-quench and steam atomizer scrubber that collects salts, ash and trace metals in the liquid phase. Water is re-circulated in the quench unit until a predetermined amount of suspended solids or dissolved salts are present. After reaching the threshold limit, "dirty liquid", also called "blowdown", is pumped to a storage tank in preparation for treatment and disposal. The air pollution control system is coupled to a HEPA pre-filter/filter unit, which removes particulate matter from the flue gas stream (1).The objective of this report is to review existing literature data on the stability of zinc bromide (ZnBr2) at CIF operating temperatures (>870 degrees C (1600 degrees F) and determine what the combustion products are in the presence of excess air. The partitioning of the combustion products among the quencher/scrubber solution, bottom ash and stack will also be evaluated. In this report, side reactions between zinc bromide and its combustion products with fuel oil were not taken into consideration.

  11. Electrophysiological study of intravenous pinaverium bromide in cardiology.

    PubMed

    Guerot, C; Khemache, A; Sebbah, J; Noel, B

    1988-01-01

    Pinaverium bromide is a musculotropic spasmolytic agent which acts by inhibiting transmembrane calcium movements, an effect similar to that of verapamil. Because of this, an investigation was carried out to see if it had any electrophysiological effects in patients with various cardiac disorders. In an open study, 10 patients received 2 mg pinaverium bromide intravenously. In a double-blind study, 10 patients received 4 mg pinaverium bromide intravenously and 10 patients placebo. Patients included those with either normal or pathological basal conduction, such as bundle-branch block and 1st degree atrioventricular block. Measurements were made of electrophysiological parameters before and 10 minutes after injection. The results showed that neither of the two doses of pinaverium bromide had any effect on atrial excitability, sino-atrial conduction, node and trunk atrioventricular conduction or on intraventricular conduction. No significant difference was seen in comparison with placebo. Pinaverium bromide had no anti-arrhythmic properties in these studies. Local, cardiac and general clinical tolerability was good in all patients. PMID:3219882

  12. Does bromide cause conversion of epilepsy to psychosis?

    PubMed

    Lund, M

    1997-04-01

    The aim of this study is to find out whether bromide was able to cause conversion of epilepsy to psychosis i.e., so-called paradoxical normalization such as has been seen in treatment with modern antiepileptic drugs. Spontaneous conversion has been known for three hundred years. Locock introduced bromide in the treatment of epilepsy in 1857. Belgrave wrote in 1868 on its effect on epileptic attacks and concommitant insanity. In 1868 Holm observed reduction of the frequency of seizures at the same time as psychotic symptoms or just dysphoria. In 1875 Voisin described a dose-dependent intoxication with psychosis and/or neurological signs. Stark in 1875 and Bannister in 1881 were the first to clearly describe the antagonism between epileptic seizures and psychotic symptoms, an antagonism or conversion described by many authors, both in cases with high and low dosage, and with and without intoxication. Thus, the title of this paper should be answered in the affirmative. Bromide has been used as a sedative and has rarely caused intoxication. Thus the presence of epilepsy is not a condition for the development of bromide intoxication. A case with epilepsy and fatal massive bromide intoxication is reported. It is discussed whether the pathological findings give support to Wolf's hypothesis of latent epileptic activity in subcortical pathways during "normalization".

  13. Effect of Bromide-Hypochlorite Bactericides on Microorganisms1

    PubMed Central

    Shere, Lewis; Kelley, Maurice J.; Richardson, J. Harold

    1962-01-01

    A new principle in compounding stable, granular bactericidal products led to unique combinations of a water-soluble inorganic bromide salt with a hypochlorite-type disinfectant of either inorganic or organic type. Microbiological results are shown for an inorganic bactericide composed of chlorinated trisodium phosphate containing 3.1% “available chlorine” and 2% potassium bromide, and for an organic bactericide formulated from sodium dichloroisocyanurate so as to contain 13.4% “available chlorine” and 8% potassium bromide. Comparison of these products with their nonbromide counterparts are reported for Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Streptococcus lactis, Aerobacter aerogenes, and Proteus vulgaris. Test methods employed were the Chambers test, the A.O.A.C. Germicidal and Detergent Sanitizer-Official test, and the Available Chlorine Germicidal Equivalent Concentration test. The minimal killing concentrations for the bromide-hypochlorite bactericides against this variety of organisms were reduced by a factor 2 to 24 times those required for similar hypochlorite-type disinfectants not containing the bromide. PMID:13977149

  14. Comparison of two colorimetric assays to determine viral infectivity in micro culture virus titration.

    PubMed

    Parida, M M; Pandya, G; Bhargava, R; Bhattacharya, R; Jana, A M

    1999-12-01

    Efficacy of two colorimetric assays, viz. MTT (3-4,5-dimethylthiazol-2-(yl-2,5-diphenyl tetrazolium bromide) and neutral red (NR) assays, performed by integrating them to micro culture virus titration (MCVT), was compared with the conventional MCVT method in terms of percentages of infectivity and 50% infectivity end points by employing Polio virus type-3 and Dengue virus type 4 as the candidate viruses. The results suggested that MTT assay has an edge over NR assay as well as conventional MCVT method. For the first time, NR assay has been successfully employed for the determination of virus infectivity titre.

  15. Screening and Antiviral Analysis of Phages That Display Peptides with an Affinity to Subunit C of Porcine Aminopeptidase

    PubMed Central

    Guo, Donghua; Zhu, Qinghe; Feng, Li

    2013-01-01

    The purified C subunit of the recombinant porcine aminopeptidase N (rpAPN-C) protein was used as an immobilized target to screen potential ligands against rpAPN-C from a 12-mer phage display random peptide library. After five rounds of biopanning, five phage clones showed specific binding affinities to rpAPN-C. In 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assays, the phage clone PM1, which contained the HDAISWTHYHPW peptide sequence, had a protective effect against TGEV infection in swine testis cells. Therefore, the HDAISWTHYHPW peptide sequence has a potential use as a small molecular therapeutic agent against TGEV infection. PMID:24111863

  16. Antiproliferative Effect of Solanum nigrum on Human Leukemic Cell Lines

    PubMed Central

    Gabrani, Reema; Jain, Ramya; Sharma, Anjali; Sarethy, Indira P.; Dang, Shweta; Gupta, S.

    2012-01-01

    Solanum nigrum is used in various traditional medical systems for antiproliferative, antiinflammatory, antiseizure and hepatoprotective activities. We have evaluated organic solvent and aqueous extracts obtained from berries of Solanum nigrum for antiproliferative activity on leukemic cell lines, Jurkat and HL-60 (Human promyelocytic leukemia cells). The cell viability after the treatment with Solanum nigrum extract was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay. Results indicated increased cytotoxicity with increasing extract concentrations. Comparative analysis indicated that 50% inhibitory concentration value of methanol extract is the lowest on both cell lines. PMID:23716874

  17. Scopararanes C-G: new oxygenated pimarane diterpenes from the marine sediment-derived fungus Eutypella scoparia FS26.

    PubMed

    Sun, Li; Li, Dongli; Tao, Meihua; Chen, Yuchan; Dan, Feijun; Zhang, Weimin

    2012-03-01

    Five new oxygenated pimarane diterpenes, named scopararanes C-G (1-5) were isolated from the culture of a marine sediment-derived fungus Eutypella scoparia FS26 obtained from the South China Sea. The structures of these compounds were established on the basis of extensive spectroscopic analysis. The absolute configurations of compounds 1-5, were determined by CD spectroscopic analysis and comparison with literature data. All isolated compounds (1-5) were evaluated for their cytotoxic activities against MCF-7, NCI-H460, and SF-268 tumor cell lines by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) method.

  18. IR, Raman and SERS spectra of propantheline bromide.

    PubMed

    Baraldi, C; Freguglia, G; Tinti, A; Sparta, M; Alexandrova, A N; Gamberini, M C

    2013-02-15

    The two known propantheline bromide polymorphs (form I and form II) were studied and characterized by a multianalytical approach. In the present work, the identification of propantheline bromide polymorphic forms through vibrational IR spectroscopies are presented and for the first time Raman microscopy and hot stage Raman microscopy (HSRM) studies are reported. Finally, quantum mechanical calculations were performed. For assisting the assignment of the experimental picks, the two IR spectra of the most and least stable representatives of a set of 56 conformers are calculated and studied. DSC thermograms data, are also reported. The surface enhanced Raman scattering (SERS) spectrum was also recorded in a silver colloid; it could be inferred that propantheline bromide is adsorbed on silver colloid through the oxygen atom with the molecular plane perpendicular to the metal surface.

  19. Intensification of sonochemical degradation of malachite green by bromide ions.

    PubMed

    Moumeni, Ouarda; Hamdaoui, Oualid

    2012-05-01

    Sonochemical oxidation has been investigated as a viable advanced oxidation process (AOP) for the destruction of various pollutants in water. Ultrasonic irradiation generates ()OH radicals that can recombine, react with other gaseous species present in the cavity, or diffuse out of the bubble into the bulk liquid medium where they are able to react with solute molecules. The extent of degradation of an organic dye such as malachite green (MG) is limited by the quantity of hydroxyl radicals diffused from cavitation bubbles. In this work, the effect of bromide ions on sonolytic degradation of MG was investigated. The obtained results clearly demonstrated the considerable enhancement of sonochemical destruction of MG in the presence of bromide. No significant differences were observed in the presence of chloride and sulfate, excluding the salting-out effect. Positive effect of bromide ions, which increases with increasing bromide level and decreasing MG concentration, is due to the generation of dibromine radical anion (Br(2)(-)) formed by reaction of Br(-) with ()OH radicals followed by rapid complexation with another anion. The generated Br(2)(-) radicals, reactive but less than ()OH, are likely able to migrate far from the cavitation bubbles towards the solution bulk and are suitable for degradation of an organic dye such as MG. Additionally, Br(2)(-) radicals undergo radical-radical recombination at a lesser extent than hydroxyl radicals and would be more available than ()OH for substrate degradation, both at the bubble surface and in the solution bulk. This effect compensates for the lower reactivity of Br(2)(-) compared to ()OH toward organic substrate. Addition of bromide to natural and sea waters induces a slight positive effect on MG degradation. In the absence of bromide, ultrasonic treatment for the removal of MG was promoted in complex matrices such as natural and sea waters.

  20. Methyl bromide emissions from a covered field: II. Volatilization

    SciTech Connect

    Yates, S.R.; Gan, J.; Ernst, F.F.

    1996-01-01

    An experiment to investigate the environmental fate and transport of methyl bromide in agricultural fields is described. The methyl bromide volatilization rate was determined as a function of time for conditions where methyl bromide was applied at a rate of 843 kg in a 3.5-ha (i.e., 240 kg/ha) field covered with plastic at a depth of 25 cm. Three methods were used to estimate the methyl bromide volatilization rate, including: the aerodynamic, theoretical profile shape and integrated horizontal flux methods. The highest methyl bromide volatilization rates were at the beginning of the experiment. Within the first 24 h, approximately 36% of the applied methyl bromide mass was lost. Diurnally, the largest volatilization rates occurred during the day when temperatures were high and the atmosphere was unstable. Cooler temperatures, light winds, and neutral to stable atmospheric conditions were present at night, reducing the flux. The total emission calculated using these methods was found to be approximately 64% ({+-} 10%) of the applied mass. A mass balance was calculated using each flux estimation technique and several methods for analyzing the data. The average mass recovery using all the flux methods was 867 kg ({+-}83 kg), which was 102.8% ({+-}9.8%) of the applied (i.e., 843 kg). The range in the mass balance percent (i.e., percent of applied mass that is measured) is from 88 to 112%. The averaged mass balance percent for the aerodynamic method, which involved using the measured data directly, was approximately 100.8%. The total emission calculated using the aerodynamic method was found to be approximately 62% ({+-}11%) of the applied mass. 29 refs., 7 figs., 1 tab.

  1. Photochemistry of alkyl bromides trapped in water ice films

    NASA Astrophysics Data System (ADS)

    Schrems, O.; Okaikwei, B.; Bluszcz, Th.

    2012-04-01

    Photochemical reactions of atmospheric trace gases taking place at the surface of atmospheric ice particles and in bulk ice are important in stratospheric and tropospheric chemistry but also in polar and alpine snowpack chemistry. Consequently, the understanding of the uptake und incorporation of atmospheric trace gases in water ice as well as their interactions with water molecules is very important for the understanding of processes which occur in ice particles and at the air/ice interface. Reactive atmospheric trace gases trapped in ice are subject of photochemical reactions when irradiated with solar UV radiation. Among such compounds bromine species are highly interesting due to their potential of depleting ozone both in the stratosphere and troposphere. Organic bromine gases can carry bromine to the stratosphere. Methyl bromide (CH3Br) is the largest bromine carrier to the stratosphere. It has both natural and anthropogenic sources. In this contribution we will present the results of our laboratory studies of alkyl bromides (methyl, bromide (CH3Br), dimethyl bromide (CH2Br2), n-propyl bromide (C3H7Br), 1,2-dibromoethane C2H4Br2)), trapped in water ice. We have simulated the UV photochemistry of these brominated alkanes isolated in ice films kept at 16 K and for comparison in solid argon matrices. The photoproducts formed in the ice have been identified by means of FTIR spectroscopy. Reflection absorption infrared spectroscopy (RAIRS) is especially useful to study nascent ice surfaces, kinetics of adsorption/decomposition, and heterogeneous catalysis. Among the observed photoproducts we could identify carbon monoxide and carbon dioxide for each alkyl bromide studied. The photoproduct HBr is dissociated in the bulk ice. Based on the experimental observations possible reaction mechanisms will be discussed.

  2. Investigation of possible interaction between pinaverium bromide and digoxin.

    PubMed

    Weitzel, O; Seidel, G; Engelbert, S; Berksoy, M; Eberhardt, G; Bode, R

    1983-01-01

    A single-blind study was carried out in 25 patients, who were receiving maintenance therapy for congestive heart failure with digoxin, to investigate the effect on steady-state plasma digoxin levels of concomitant administration of the spasmolytic, pinaverium bromide (50 mg 3-times daily). Patients received pinaverium bromide for 12 days followed by placebo for a further 7 days. Assessment of the results in 21 patients showed no evidence of any statistically significant variations in plasma digoxin levels during either treatment period or in the clinical observations which might indicate drug interaction. PMID:6653138

  3. Action of pinaverium bromide on calmodulin-regulated functions.

    PubMed

    Wuytack, F; De Schutter, G; Casteels, R

    1985-08-01

    Pinaverium bromide at concentrations below 10(-5) M did not inhibit calmodulin-dependent enzymes such as phosphodiesterase and the Ca transport ATPase of the plasma membrane. At higher concentrations the compound interacted with the stimulation of those enzymes by calmodulin and also inhibited the calmodulin-independent activity. A similar inhibitory action was observed for the NaK ATPase. It is concluded that the inhibitory action of pinaverium bromide on smooth muscle concentration at concentrations below 10(-5) M was due to its interaction with the voltage-dependent Ca channels and not to its interference with the calmodulin-dependent activation of the contractile proteins. PMID:2995077

  4. Adsorption Isotherm studies of Methyl Bromide adsorbed on Magnesium Oxide

    NASA Astrophysics Data System (ADS)

    Burns, Teresa; Sprung, Michael

    2005-03-01

    Understanding the interaction of polar molecules with ionic surfaces is technologically very important. Using high precision, volumetric adsorption isotherms the layering properties of methyl bromide on the MgO(100) surface were examined between 164 K and 179 K. Methyl bromide (Triple point = 179.49K) is found to exhibit two layering transitions within this temperature interval. Thermodynamic quantities derived from this study including the layering transition temperatures, the 2D compressibility, layer enthalpy and entropy of adsorption, and the isosteric enthalpy of adsorption will be presented. Comparisons with the adsorption properties of methyl chloride and methyl iodide will also be included.

  5. Versatile Route to Arylated Fluoroalkyl Bromide Building Blocks.

    PubMed

    Kaplan, Peter T; Vicic, David A

    2016-02-19

    New difunctionalized and fluoroalkylated silyl reagents have been prepared that react with silver and copper salts to afford active catalysts that can be used to synthesize arylated fluoroalkyl bromide building blocks. It has been shown that the [(phen)Ag(CF2)nBr] intermediates are capable of transferring both the phenanthroline ligand and the fluoroalkyl bromide chain to copper iodide, eliminating the need for a preligated copper salt precursor. The methodology is compatible with various chain lengths of the fluoroalkyl halide functionality. PMID:26820388

  6. Correlation of the melting points of potential ionic liquids (imidazolium bromides and benzimidazolium bromides) using the CODESSA program.

    PubMed

    Katritzky, Alan R; Jain, Ritu; Lomaka, Andre; Petrukhin, Ruslan; Karelson, Mati; Visser, Ann E; Rogers, Robin D

    2002-01-01

    The melting points of several imidazolium-based ionic liquids or ionic liquid analogues were correlated using the CODESSA program in order to develop predictive tools for determination of suitable ionic liquid salts. The data set consisted of melting point data (degrees C) for 104 substituted imidazolium bromides divided on the basis of the N-substituents into three subsets: A-57 compounds, B-29 compounds, and C-18 compounds. The 45 benzimidazolium bromides form set D. Five-parameter correlations were obtained for (i) set A with R2 = 0.7442, (ii) set B with R2 = 0.7517, and (iii) set D with R2 = 0.6899, while set C was correlated with a three parameter equation with R(2) = 0.9432. These descriptors for predicting the melting points of the imidazolium and benzimidazolium bromides were based on the size and electrostatic interactions in the cations.

  7. Magnesium Lewis Acid Assisted Oxidative Bromoetherification Involving Bromine Transfer from Alkyl Bromides with Aldehydes by Umpolung of Bromide.

    PubMed

    Moriyama, Katsuhiko; Nishinohara, Chihiro; Togo, Hideo

    2016-08-16

    An oxidative bromoetherification involving a bromine transfer from alkyl bromides upon reacting them with aldehydes in a Grignard reaction with a concurrent oxidation of bromide was developed to provide substituted tetrahydrofurans in high yields. This reaction, which proceeds through two types of bromine transfer, was promoted by the addition of a Brønsted acid. Mechanistic studies suggested that a magnesium Lewis acid activates hypobromate, which is generated in situ from the reaction of bromide and Oxone to improve the electrophilicity of the bromonium ion (Br(+) ) for the oxidative bromoetherification of alkenyl alcohols. Furthermore, the magnesium Lewis acid catalyzed oxidative bromoetherification of an alkenyl alcohol proceeded to provide a cyclization product in 92 % yield. PMID:27304660

  8. Magnesium Lewis Acid Assisted Oxidative Bromoetherification Involving Bromine Transfer from Alkyl Bromides with Aldehydes by Umpolung of Bromide.

    PubMed

    Moriyama, Katsuhiko; Nishinohara, Chihiro; Togo, Hideo

    2016-08-16

    An oxidative bromoetherification involving a bromine transfer from alkyl bromides upon reacting them with aldehydes in a Grignard reaction with a concurrent oxidation of bromide was developed to provide substituted tetrahydrofurans in high yields. This reaction, which proceeds through two types of bromine transfer, was promoted by the addition of a Brønsted acid. Mechanistic studies suggested that a magnesium Lewis acid activates hypobromate, which is generated in situ from the reaction of bromide and Oxone to improve the electrophilicity of the bromonium ion (Br(+) ) for the oxidative bromoetherification of alkenyl alcohols. Furthermore, the magnesium Lewis acid catalyzed oxidative bromoetherification of an alkenyl alcohol proceeded to provide a cyclization product in 92 % yield.

  9. Nickel-Catalyzed Reductive Cross-Coupling of Aryl Bromides with Alkyl Bromides: Et3N as the Terminal Reductant.

    PubMed

    Duan, Zhengli; Li, Wu; Lei, Aiwen

    2016-08-19

    Reductive cross-coupling has emerged as a direct method for the construction of carbon-carbon bonds. Most cobalt-, nickel-, and palladium-catalyzed reductive cross-coupling reactions to date are limited to stoichiometric Mn(0) or Zn(0) as the reductant. One nickel-catalyzed cross-coupling paradigm using Et3N as the terminal reductant is reported. By using this photoredox catalysis and nickel catalysis approach, a direct Csp(2)-Csp(3) reductive cross-coupling of aryl bromides with alkyl bromides is achieved under mild conditions without stoichiometric metal reductants. PMID:27472556

  10. REVIEW OF CONTROL OPTIONS FOR METHYL BROMIDE IN COMMODITY TREATMENT

    EPA Science Inventory

    The report describes recent developments in the control of methyl bromide (MeBr) and discusses technical considerations and requirements for and economic feasibility of recovery. (NOTE: MeBr, fumigant for agricultural commodities, is an ozone depleting chemical. The U.S. EPA has ...

  11. Pancuronium bromide induced joint contractures in the newborn.

    PubMed Central

    Sinha, S K; Levene, M I

    1984-01-01

    We report three infants paralysed with pancuronium bromide as an adjunct to mechanical ventilation, who developed multiple joint contractures. In two term infants, gentamicin and phenobarbitone given together with pancuronium may have potentiated its effect, and in one preterm infant contractures, which became more severe after paralysis, were present at birth. PMID:6696501

  12. Nickel-Catalyzed Reductive Amidation of Unactivated Alkyl Bromides.

    PubMed

    Serrano, Eloisa; Martin, Ruben

    2016-09-01

    A user-friendly, nickel-catalyzed reductive amidation of unactivated primary, secondary, and tertiary alkyl bromides with isocyanates is described. This catalytic strategy offers an efficient synthesis of a wide range of aliphatic amides under mild conditions and with an excellent chemoselectivity profile while avoiding the use of stoichiometric and sensitive organometallic reagents. PMID:27357076

  13. On the existence of 'L-alanine cadmium bromide'.

    PubMed

    Srinivasan, Bikshandarkoil R

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  14. Methyl bromide phase out could affect future reforestation efforts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide has long been an integral component in producing healthy tree seedlings in forest nurseries of California, Idaho, Montana, Oregon and Washington. The fumigant was supposed to be completely phased out of use in the United States of America by 2005, but many forest nurseries continue to...

  15. Investigation of bromide's spectra by high resolution UV-laser

    NASA Astrophysics Data System (ADS)

    Zhang, Jin; Ma, Jian-guo

    2011-12-01

    Experimental investigation has been carried out for dissociation/ionisation of methyl bromide using time of flight mass spectrometer, then, the mass signals were assigned to H+, CHm+ (m= 0-3), iBr+ (i = 79, 81), and the main processes of multi-photon ionization and dissociation of CH3Br were given.

  16. Ipratropium bromide spray as treatment for sialorrhea in Parkinson's disease.

    PubMed

    Thomsen, Teri R; Galpern, Wendy R; Asante, Abena; Arenovich, Tamara; Fox, Susan H

    2007-11-15

    Sialorrhea is a significant problem in advanced Parkinson's disease (PD). Current treatment options include systemic anticholinergics which frequently cause side effects. We hypothesized that sublingual application of ipratropium bromide spray, an anticholinergic agent that does not cross the blood brain barrier, may reduce drooling without systemic side effects. We performed a randomized, double blind, placebo-controlled, crossover study in 17 subjects with PD and bothersome drooling. Patients were randomized to receive ipratropium bromide or placebo (one to two sprays, maximum of four times per day) for 2 weeks followed by a 1 week washout and crossover for further 2 weeks of treatment. The primary outcome was an objective measure of weight of saliva production. Secondary outcomes were subjective rating of severity and frequency of sialorrhoea using home diaries, United Parkinson's Disease Rating Scale (UPDRS) part II salivation subscore, parkinsonian disability using UPDRS, and adverse events. Ipratropium bromide spray had no significant effect on weight of saliva produced. There was a mild effect of treatment on subjective measures of sialorrhea. There were no significant adverse events. Ipratropium bromide spray was well tolerated in subjects with PD. Although it did not affect objective measures of saliva production, further studies in parkinsonism may be warranted.

  17. Depleting methyl bromide residues in soil by reaction with bases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite generally being considered the most effective soil fumigant, methyl bromide (MeBr) use is being phased out because its emissions from soil can lead to stratospheric ozone depletion. However, a large amount is still currently used due to Critical Use Exemptions. As strategies for reducing the...

  18. EFFECT OF BROMIDE ION ON FORMATION OF HAAS DURING CHLORINATION

    EPA Science Inventory

    loacetic acids (HAAs) during chlorination and he effects of independent variables, including pH, reaction time, and chlorine dosage. Almost all of the indpendent loaetic acids (HAAs) during chlorin...designed to statistically evaluate the influence of bromide ion on the formatio...

  19. T-type Ca2+ channel modulation by otilonium bromide

    PubMed Central

    Strege, Peter R.; Sha, Lei; Beyder, Arthur; Bernard, Cheryl E.; Perez-Reyes, Edward; Evangelista, Stefano; Gibbons, Simon J.; Szurszewski, Joseph H.

    2010-01-01

    Antispasmodics are used clinically to treat a variety of gastrointestinal disorders by inhibition of smooth muscle contraction. The main pathway for smooth muscle Ca2+ entry is through L-type channels; however, there is increasing evidence that T-type Ca2+ channels also play a role in regulating contractility. Otilonium bromide, an antispasmodic, has previously been shown to inhibit L-type Ca2+ channels and colonic contractile activity. The objective of this study was to determine whether otilonium bromide also inhibits T-type Ca2+ channels. Whole cell currents were recorded by patch-clamp technique from HEK293 cells transfected with cDNAs encoding the T-type Ca2+ channels, CaV3.1 (α1G), CaV3.2 (α1H), or CaV3.3 (α1I) alpha subunits. Extracellular solution was exchanged with otilonium bromide (10−8 to 10−5 M). Otilonium bromide reversibly blocked all T-type Ca2+ channels with a significantly greater affinity for CaV3.3 than CaV3.1 or CaV3.2. Additionally, the drug slowed inactivation in CaV3.1 and CaV3.3. Inhibition of T-type Ca2+ channels may contribute to inhibition of contractility by otilonium bromide. This may represent a new mechanism of action for antispasmodics and may contribute to the observed increased clinical effectiveness of antispasmodics compared with selective L-type Ca2+ channel blockers. PMID:20203058

  20. Evaluation of the potential of alkylresorcinols as superoxide anion scavengers and sox-regulon modulators using nitroblue tetrazolium and bioluminescent cell-based assays.

    PubMed

    Gryazeva, Irina V; Davydova, Оlga K; Deryabin, Dmitrii G

    2015-03-01

    The antioxidant activities of five alkylresorcinol (AR) homologs with alkyl chains of 1, 3, 5 6 and 12 carbon atoms were studied using molecular and cellular assays for superoxide anions (O2.-). The effect of ARs as superoxide anion scavengers was assessed using the photochemical reaction of spontaneous photo-reduced flavin re-oxidation. In this system, ARs reaction with O2.- produced dye derivatives, as C6- and C12-AR prevented the O2.--induced conversion of nitroblue tetrazolium into formazan in AR-containing mixtures. The influence of ARs on soxS gene expression and bacterial cell viability was studied with the luminescent Escherichia coli K12 MG1655 psoxS'::luxCDABE-AmpR strain, showing low basal light emission. This increased significantly during paraquatinduced oxidative stress as a consequence of the simultaneous transcription of soxS-gene and lux-gene fusion. ARs with alkyl chains containing 5-12 carbon atoms at concentrations of 0.1-1.0 μM weakly induced soxS-gene expression, whereas 1-10 mM repressed it. This respectively increased or decreased the bacterial cell resistance to O2.- -related oxidative stress. AR derivatives lost their protective activity from reactions with superoxide anions, which required increased soxS gene expression for cell viability. These results show the dual nature of ARs, which possess direct antioxidant properties and the ability to indirectly regulate the activity of cellular antioxidative defense mechanisms.

  1. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  2. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  3. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  4. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 false Bromide ion and residual bromine... Tolerances § 180.519 Bromide ion and residual bromine; tolerances for residues. (a) General. The food additives, bromide ion and residual bromine, may be present in water, potable in accordance with...

  5. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  6. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Ethanaminium, N- -N-ethyl-, bromide... Substances § 721.4090 Ethanaminium, N- -N-ethyl-, bromide. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as ethanaminium, N- -N-ethyl-, bromide (PMN...

  7. Uptake of ozone to mixed sodium bromide/ citric acid solutions

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Tao; Steimle, Emilie; Bartels-Rausch, Thorsten; Kato, Shunsuke; Lampimäki, Markus; Brown, Matthew; van Bokhoven, Jeroen; Nolting, Frithjof; Kleibert, Armin; Türler, Andreas; Ammann, Markus

    2013-04-01

    Sea-salt solution - air interfaces play an important role in the chemistry of the marine boundary layer. The reaction of ozone (O3) with bromide is of interest in the context of formation of photolabile halogens (Br2, BrCl) in the marine boundary layer. Recent experiments have suggested that the bromide oxidation rate is related to the surface concentration of bromide [1] and inversely related to the gas phase concentration of O3, an indication for a precursor mediated reaction at the surface [2]. So far, the effect of organics (such as those occurring at the ocean surface or in marine aerosols) on the reaction of O3 with bromide aerosols has not been studied yet. In our study we investigate the uptake kinetics of O3 to a mixed solution of sodium bromide (NaBr) and citric acid (CA), which represents highly oxidized organic compounds present in the environment, with a well-established coated wall flow tube technique, which leads to exposure of the film to O3 allowing the heterogeneous reactions to take place and the loss of O3 being measured. The results indicate that the uptake of O3 to the films with the higher bromide concentrations (0.34M and 4M) is independent of the gas phase concentration and roughly consistent with uptake limited by reaction in the bulk. For the lower bromide concentration (84mM), however, we observe a trend of the uptake coefficient to decrease with increasing O3 concentration, indicating an increasing importance of a surface reaction. In an attempt to constrain the kinetic data, we employed X-ray photoelectron spectroscopy (XPS) to get insight into the surface composition of the aqueous solution - air interface. Previous XPS studies have shown that halide ion concentrations are enhanced at the aqueous solution air interface [3-4], which likely promotes the surface reactions of bromide or iodide with O3. A first XPS study of ternary solutions of KI with butanol indicated the importance of specific interactions of the cation with the alcohol

  8. Aluminum electroplating on steel from a fused bromide electrolyte

    SciTech Connect

    Prabhat K. Tripathy; Laura A. Wurth; Eric J. Dufek; Toni Y. Gutknecht; Natalie J. Gese; Paula Hahn; Steven M. Frank; Guy L. Frederickson; J. Stephen Herring

    2014-08-01

    A quaternary bromide bath (LiBr–KBr–CsBr–AlBr3) was used to electro-coat aluminum on steel substrates. The electrolytewas prepared by the addition of AlBr3 into the eutectic LiBr–KBr–CsBr melt. A smooth, thick, adherent and shiny aluminum coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminum coverage. Both salt immersion and open circuit potential measurement suggested that the coatings did display a good corrosionresistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminum coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminumcoating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

  9. Viscosity and density of some lower alkyl chlorides and bromides

    SciTech Connect

    Rutherford, W.M.

    1988-07-01

    A high-pressure capillary viscometer, used previously to measure the viscosity of methyl chloride was rebuilt to eliminate the first-order dependence of the measured viscosity on the value assumed for the density of the fluid being investigated. At the same time, the system was arranged so that part of the apparatus could be used to measure density by a volumetric displacement technique. Viscosity and density were measured for ethyl chloride, 1-chloropropane, 1-chlorobutane, methyl bromide, ethyl bromide, and 1-bromopropane. The temperature and pressure ranges of the experiments were 20-150 /sup 0/C and 0.27-6.99 MPa, respectively. The accuracy of the viscosity measurements was estimated to be +-1% and of the density measurements, +-0.2%.

  10. Preparation of ethyl magnesium bromide for regiospecific analysis of triacylglycerols.

    PubMed

    Ando, Yasuhiro; Tomita, Yuki; Haba, Yusuke

    2008-01-01

    This paper presents a procedure for preparation of a Grignard reagent, ethyl magnesium bromide, used for partial deacylation of triacylglycerols (TAG) in their regiospecific analysis. Magnesium turnings were reacted with ethereal solution of bromoethane in a screw-capped test tube to synthesize 2 mL of 1 M ethyl magnesium bromide. Continuously stirred with a vortex mixer, the reaction smoothly proceeded at room temperature. Regiospecific analysis of 1,3-distearoyl-2-oleoylglycerol using this product showed that fatty acid compositions of the sn-1(3) and sn-2 positions were contaminated by less than 2 mol% of fatty acids migrated from isomeric positions. The analyses of lard and cod liver/mackerel oil TAG showed typical distribution patterns of 16:0, 22:5n-3 and 22:6n-3 in pig and fish depot TAG. These results confirmed the view that the freshly prepared reagent is usable for regiospecific analysis of TAG.

  11. Study of ferroelectric characteristics of diisopropylammonium bromide films

    NASA Astrophysics Data System (ADS)

    Thirmal, C.; Biswas, P. P.; Shin, Y. J.; Noh, T. W.; Giridharan, N. V.; Venimadhav, A.; Murugavel, P.

    2016-09-01

    Organic molecular ferroelectrics are highly desirable due to their numerous advantages. In the present work, a thick film of diisopropylammonium bromide organic molecular ferroelectric is fabricated on the ITO/glass substrate. The grown film shows preferential orientation along the c-axis with a ferroelectric transition at 419 K. The piezoresponse force microscopic measurements are done in a dual ac resonance tracking mode for its switching characteristics. The amplitude and phase images of the oppositely written domain patterns exhibit a clear contrast with 180° phase difference. The dynamical spectroscopic studies reveal a butterfly loop in amplitude and hysteretic character of the phase which are the expected characteristics features of ferroelectrics. In addition, the macroscopic polarization versus electric field hysteresis gives an additional proof for ferroelectric character of the film with the maximum polarization of 3.5 μC/cm2. Overall, we have successfully fabricated diisopropylammonium bromide organic films and demonstrated its room temperature ferroelectric characteristics.

  12. Aluminium Electroplating on Steel from a Fused Bromide Electrolyte

    SciTech Connect

    Prabhat Tripathy; Laura Wurth; Eric Dufek; Toni Y. Gutknecht; Natalie Gese; Paula Hahn; Steven Frank; Guy Fredrickson; J Stephen Herring

    2014-08-01

    A quaternary bromide bath (LiBr-KBr-CsBr-AlBr3) was used to electro-coat aluminium on steel substrates. The electrolyte was prepared by the addition of AlBr3 into the eutectic LiBr-KBr-CsBr melt. A smooth, thick, adherent and shiny aluminium coating could be obtained with 80 wt.% AlBr3 in the ternary melt. The SEM photographs of the coated surfaces suggest the formation of thick and dense coatings with good aluminium coverage. Both salt immersion and open circuit potential measurement suggest that the coatings did display good corrosion-resistance behavior. Annealing of the coated surfaces, prior to corrosion tests, suggested the robustness of the metallic aluminium coating in preventing the corrosion of the steel surfaces. Studies also indicated that the quaternary bromide plating bath can potentially provide a better aluminium coating on both ferrous and non-ferrous metals, including complex surfaces/geometries.

  13. Oceanic Uptake of Methyl Bromide: Implications for Oceanic Production

    NASA Astrophysics Data System (ADS)

    Yvon-Lewis, S. A.; Butler, J. H.; King, D. B.; Saltzman, E. S.; Tokarczyk, R.

    2002-12-01

    Methyl bromide (CH3Br) is a source of inorganic bromine (Br) in the stratosphere, where it contributes to the depletion of stratospheric ozone. Unlike the chlorofluorocarbons, which are entirely anthropogenic, methyl bromide has both natural and anthropogenic sources. At ~10 parts per trillion in the troposphere, methyl bromide is believed to be the single largest contributor of stratospheric Br. Once in the stratosphere, Br is approximately 50 times more effective in depleting stratospheric ozone than Cl. However, the budget for CH3Br remains largely unbalanced with known sinks outweighing sources by ~50%. With production and degradation occurring in the ocean, the ocean is both a source and a sink for CH3Br. The balance between production and degradation results in the net undersaturation of CH3Br that has been observed over much of the world's ocean with an estimated global net ocean sink ranging from -11 to -20 Gg/y [King et al., 2000 and references therein]. However, effects of climate change, such as changes in windspeed distribution or sea-surface temperature could alter this balance. Modeling the potential effect of such forcing on the net flux of this important trace gas requires an understanding of the factors controlling the distributions of production and degradation in the surface ocean. During three recent research cruises (North Atlantic, North Pacific, and Southern Ocean), CH3Br degradation rate constants were measured along with saturation anomalies. Here we incorporate these data into a gridded global box model to examine the distribution of oceanic production rates necessary to support the observations. King, D.B., J.H. Butler, S.A. Montzka, S.A. Yvon-Lewis, and J.W. Elkins, Implications of methyl bromide supersaturations in the temperate North Atlantic Ocean, J. of Geophys. Res., 105 (D15), 19763-19769, 2000.

  14. Problems with NIOSH method 2520 for methyl bromide

    SciTech Connect

    Tharr, D.

    1994-03-01

    The National Institute for Occupational Safety and Health (NIOSH) publishes the NIOSH Manual of Analytical Methods (NMAM), a collection of analytical methods for characterizing exposures to environmental chemicals. When an industrial hygienist selects a method to monitor worker exposure, it is important to remember that not all the methods in the NMAM have undergone the same level of evaluation, as the following case demonstrates. As part of an industrywide study of the health effects resulting from methyl bromide exposure in structural and agricultural applicators, NIOSH researchers conducted industrial hygiene monitoring for methyl bromide in Florida during July 1990. NIOSH method 2520 was used. This method recommends use of two charcoal tubes (400 mg/100 mg) in series, desorption with carbon disulfide, and analysis by gas chromatography with a flame ionization detector. Sampling results from these surveys indicated a capacity problem. A project was then initiated to determine the reason for the methyl bromide breakthrough that occurred during industrial hygiene monitoring. While conducting research to define and solve this problem, several other problems were identified: reduced adsorption capacity caused by high humidity, difficulty in preparing standard solutions, sample instability, change in recovery with loading, and insufficiently low quantitation limit. The addition of a drying tube to the sampling train, as well as changes to the analytical technique, to the desorption solvent, and to the time till analysis, resulted in an improved method for methyl bromide. This case study demonstrates the importance of noting the conditions under which a method was evaluated and the benefit of testing method performance under conditions likely to exist at a field site. 5 refs.

  15. Cytotoxicity of Agaricus sylvaticus in non-tumor cells (NIH/3T3) and tumor (OSCC-3) using tetrazolium (MTT) assay.

    PubMed

    Orsine, Joice Vinhal Costa; Marques Brito, Luíssa; Silva, Renata Carvalho; Santos Almeida, Maria de Fátima Menezes; Novaes, Maria Rita Carvalho Garbi

    2013-01-01

    The purpose of this study was to assess the cytotoxic effect of the non-fractionated aqueous extract of A. sylvaticus mushroom in cultures of non-tumor cells (NIH3T3) and tumor cells (OSCC-3). The cells were maintained in DMEN cell culture medium added of 10% of fetal bovine serum and 1% antibiotic. For the cytotoxicity test we prepared the aqueous mushroom extract at concentrations of 0.01 mg.ml⁻¹, 0.02 mg.ml⁻¹, 0.04 mg.ml⁻¹, 0.08 mg.ml⁻¹, 0.16 mg.ml⁻¹, and 0.32 mg.ml⁻¹. For the culture, 2 x 10⁵ cells/ml was deposited in 96-well microplates during 24 hour incubation with subsequent exchange of medium by another containing the mushroom concentrations. After 24 hour incubation the medium was discarded and 100 ml of tetrazolium blue (MTT) was added at a concentration of 5 mg.ml⁻¹. The microplates were incubated for 2 h at 37° C. Spectrophotometric analysis was performed using 570 nm wavelength. From the values of the optical densities we determined the drug concentration capable of reducing cell viability by 50%. Therefore, the mushroom A. sylvaticus, at all concentrations tested, did not show cytotoxic effects, once the inhibitory concentration (IC₅₀) obtained for tumor cells OSCC-3 was 0.06194 mg.ml⁻¹, and the IC₅₀ checked for non-tumor cells NIH3T3 was 0,06468 mg.ml⁻¹. This test made it possible to determine that A. sylvaticus mushroom has no cytotoxic effects, suggesting its use safe for human consumption.

  16. [Detection method for the ability of hemp (Cannabis sativa L.) seed germination by the use of 2,3,5-triphenyl-2H-tetrazolium chloride (TTC)].

    PubMed

    Ogata, Jun; Kikura-Hanajiri, Ruri; Yoshimatsu, Kayo; Kiuchi, Fumiyuki; Goda, Yukihiro

    2008-11-01

    Cannabis plants show a high Delta9-tetrahydrocannabinol content and are used as a psychoactive drug. Therefore the cultivation of hemp and its possession are prohibited by law in Japan. Meanwhile, Cannabis seeds have been used as a component of shichimi-togarashi (a Japanese spice), bird feed, or a crude drug (mashinin). To exclude the possibility of germination, it is officially noticed that hemp seeds must be killed. However, the number of violators has increased in recent years. To judge the ability of seed germination, a germination test is performed. However, the test requires several days and thus has not been used for on-site inspection. In this study, we developed a rapid detection method to determine the ability of Cannabis seeds to germinate using 2,3,5-triphenyl-2H-tetrazolium chloride (TTC). The principle of the assay is as follows. The endogenous respiratory enzymes in hemp seeds convert added colorless TTC into red 1,3,5-triphenylformazan. Consequently, a living embryo is stained red, while red does not appear in the dead seeds. The reaction was active over a pH range of 8.0-9.0, and the optimum activity was found from 40 to 50 degrees C. Under the optimum conditions, we were able to determine the ability of seeds to germinate based on the presence of color within 20 min. Since this method is rapid and simple, it is applicable to on-site inspections. In addition, it could be used as an alternative technique to the germination test, because erroneous decisions is cannot occur under the assay principle.

  17. The Thz Absorption of Methyl Bromide (CH_3BR)

    NASA Astrophysics Data System (ADS)

    Ramos, Marlon; Drouin, Brian J.

    2011-06-01

    The possibility of monitoring Methyl Bromide is of interest for both environmental and health concerns. It has an ozone depletion potential of 0.2% and falls under regulations of the Clean Air Act. Neurological effects from long term exposure may result from its major use as a pesticide. Recent improvements in microwave limb sounding at mm & submm wavelengths have resulted in retrievals of Methyl Chloride from atmospheric spectra. It is conceivable that Methyl Bromide would also be measurable by this technique. In an effort to extend and improve the previous work, the THz spectrum of Methyl Bromide has been measured at JPL. We used an isotopically enriched 13CH_3Br (90%) sample and recorded spectra from 750 - 1200 GHz. Our assignment covers the CH_379Br, CH_381Br, 13CH_379Br and 13CH_381Br isotopologues with J< 66 and K< 17 for the ground vibrational state. We plan to assign vibrational satellites and investigate possible perturbations near K =12 in the ground state.

  18. [Manometric effects of pinaverium bromide in irritable bowel syndrome].

    PubMed

    Soifer, L; Varela, E; Olmos, J

    1992-01-01

    The effects of pinaverium bromide on colonic motility were investigated in a controlled, controlled, cross-over study in 32 patients with irritable bowel syndrome. Constipation was clearly predominant in one group of 16 patients, and diarrhea in the other group of 16. Manometric measurements were taken of the colonic motor response generated by distention of a balloon inserted to the rectosigmoid junction. Measurements were taken before and one hour after ingestion of two tablets containing placebo or two tablets each containing 50 mg of pinaverium bromide. Following intake of placebo the motility index increased from the basal value in patients with constipation, and resistance to distention decreased in the diarrhea group. These changes were attributable to repetition of the mechanical stimulus within a relatively brief time lapse, or more probably to the ingestion of liquid which accompanied intake of tablets. Compared with placebo, pinaverium bromide induced inhibition of both effects. From the therapeutic point of view, the decrease in motility index seen in patients with irritable bowel syndrome and constipation is particularly interesting. PMID:1295286

  19. Oral teratogenicity studies of methyl bromide in rats and rabbits.

    PubMed

    Kaneda, M; Hojo, H; Teramoto, S; Maita, K

    1998-05-01

    Teratogenicity studies of methyl bromide, a widely used fumigant, were conducted in rats and rabbits. Methyl bromide was dissolved in corn oil and administered orally to groups of 24 copulated female Crj:CD (SD) rats at dose levels of 0 (corn oil), 3, 10 or 30 mg/kg/day on days 6-15 of gestation and to groups of 18 artificially inseminated female Kbl:JW rabbits at 0, 1, 3 or 10 mg/kg/day on days 6-18 of gestation. Maternal rats and rabbits were euthanized on respective days 20 and 27 of gestation. Foetuses were examined for survival, growth and teratological alterations. Maternal toxicity was evident in the high-dose groups for both species. In these groups, maternal body weight gains and food consumption were significantly decreased during the dosing and post-dosing periods. Necropsy of maternal rats also revealed erosive lesions in the stomach and the surrounding organs. However, no treatment-related adverse effects were found in foetuses of the treated groups for both rat and rabbit studies. These results led to the conclusion that methyl bromide was not foetotoxic or teratogenic to rat and rabbit foetuses up to dose levels of 30 and 10 mg/kg/day, respectively, at which maternal toxicity was evident for both species.

  20. A simple, rapid, inexpensive assay for toxic chemicals using a bacterial indicator

    SciTech Connect

    Botsford, J.L.; Hillaker, T.; Robertson, B.; Gonzales, M.; Benavidez, M.; Jones, B.; Baker, R.; Steen, W.; Pacheco, F.; Homer, V.; Lucero, O.; Matthews, M.; Koehler, V.

    1996-12-31

    A simple test for toxic chemicals has been developed. Rhizobium meliloti is combined with the toxic chemical. A tetrazolium dye, MTT (3-[4,5-Dimethylthiazol-2-yl]2,5-diphenyl-tetrazolium bromide) is added. The bacterium reduces this dye, causing the optical absorbance to increase dramatically. The increase can be determined with a simple spectrophotometer. Toxic chemicals and minerals inhibit the reduction of the dye. Presumably the dye serves as a terminal electron acceptor for electron transport. Toxic substances presumably damage the electron transport system. The results compare favorably with published results of tests using the Microtox{trademark} assay and with the Polytox{trademark} assay. This assay is simpler and requires no specialized equipment. It should be possible to use this assay in a third world situation.

  1. Comparison of Heat and Bromide as Ground Water Tracers Near Streams

    USGS Publications Warehouse

    Constantz, J.; Cox, M.H.; Su, G.W.

    2003-01-01

    Heat and bromide were compared as tracers for examining stream/ground water exchanges along the middle reaches of the Santa Clara River, California, during a 10-hour surface water sodium bromide injection test. Three cross sections that comprise six shallow (<1 m) piezometers were installed at the upper, middle, and lower sections of a 17 km long study reach, to monitor temperatures and bromide concentrations in the shallow ground water beneath the stream. A heat and ground water transport simulation model and a closely related solute and ground water transport simulation model were matched up for comparison of simulated and observed temperatures and bromide concentrations in the streambed. Vertical, one-dimensional simulations of sediment temperature were fitted to observed temperature results, to yield apparent streambed hydraulic conductivities in each cross section. The temperature-based hydraulic conductivities were assigned to a solute and ground water transport model to predict sediment bromide concentrations, during the sodium bromide injection test. Vertical, one-dimensional simulations of bromide concentrations in the sediments yielded a good match to the observed bromide concentrations, without adjustment of any model parameters except solute dispersivities. This indicates that, for the spatial and temporal scales examined on the Santa Clara River, the use of heat and bromide as tracers provide comparable information with respect to apparent hydraulic conductivities and fluxes for sediments near streams. In other settings, caution should be used due to differences in the nature of conservative (bromide) versus nonconservative (heat) tracers, particularly when preferential flowpaths are present.

  2. Interaction between gaseous ozone and crystalline potassium bromide

    NASA Astrophysics Data System (ADS)

    Levanov, A. V.; Maksimov, I. B.; Isaikina, O. Ya.; Antipenko, E. E.; Lunin, V. V.

    2016-07-01

    The formation of nonvolatile products of the oxidation of a bromide ion during the interaction between gaseous ozone and powdered crystalline KBr is studied. It is found that potassium bromate KBrO3 is the main product of the reaction. The influence of major experimental factors (the duration of ozonation, the concentration of ozone, the humidity of the initial gas, and the temperature) on the rate of formation of bromate is studied. The effective constants of the formation of bromate during the interaction between O3 and Br- in a heterogeneous gas-solid body system and in a homogeneous aqueous solution are compared.

  3. Photodissociation of methyl chloride and methyl bromide in the atmosphere

    NASA Technical Reports Server (NTRS)

    Robbins, D. E.

    1976-01-01

    Methyl chloride (CH3Cl) and methyl bromide (CH3Br) have been suggested to be significant sources of the stratospheric halogens. The breakup of these compounds in the stratosphere by photodissociation or reaction with OH releases halogen atoms which catalytically destroy ozone. Experimental results are presented for ultraviolet photoabsorption cross sections of CH3Cl and CH3Br. Calculations are presented of loss rates for the methyl halides due to photodissociation and reaction with OH and of mixing ratios of these species in the stratosphere.

  4. Automated determination of bromide in waters by ion chromatography with an amperometric detector

    USGS Publications Warehouse

    Pyen, G.S.; Erdmann, D.E.

    1983-01-01

    An automated ion chromatograph, including a program controller, an automatic sampler, an integrator, and an amperometric detector, was used to develop a procedure for the determination of bromide in rain water and many ground waters. Approximately 10 min is required to obtain a chromatogram. The detection limit for bromide is 0.01 mg l-1 and the relative standard deivation is <5% for bromide concentrations between 0.05 and 0.5 mg l-1. Chloride interferes if the chloride-to-bromide ratio is greater than 1 000:1 for a range of 0.01-0.1 mg l-1 bromide; similarly, chloride interferes in the 0.1-1.0 mg l-1 range if the ratio is greater than 5 000:1. In the latter case, a maximum of 2 000 mg l-1 of chloride can be tolerated. Recoveries of known concentrations of bromide added to several samples, ranged from 97 to 110%. ?? 1983.

  5. Effects of pinaverium bromide and verapamil on the motility of the rat isolated colon.

    PubMed Central

    Baumgartner, A.; Drack, E.; Halter, F.; Scheurer, U.

    1985-01-01

    Pinaverium bromide was 30 times less potent than verapamil in inhibiting intraluminal pressure responses of in vitro rat colonic segments to barium chloride, acetylcholine, FK 33-824 or field stimulation. The inhibitory effects of both verapamil and pinaverium bromide on the pressure responses to field stimulation were antagonized similarly by exogenous calcium administration. These results support the concept that pinaverium bromide acts on calcium channels in the smooth muscle cell membrane. PMID:4052731

  6. Effects of pinaverium bromide and verapamil on the motility of the rat isolated colon.

    PubMed

    Baumgartner, A; Drack, E; Halter, F; Scheurer, U

    1985-09-01

    Pinaverium bromide was 30 times less potent than verapamil in inhibiting intraluminal pressure responses of in vitro rat colonic segments to barium chloride, acetylcholine, FK 33-824 or field stimulation. The inhibitory effects of both verapamil and pinaverium bromide on the pressure responses to field stimulation were antagonized similarly by exogenous calcium administration. These results support the concept that pinaverium bromide acts on calcium channels in the smooth muscle cell membrane. PMID:4052731

  7. The Renaissance of an Old Problem: Highly Regioselective Carboxylation of 2-Alkynyl Bromides with Carbon Dioxide.

    PubMed

    Miao, Bukeyan; Li, Gen; Ma, Shengming

    2015-11-23

    A steric effect-controlled, zinc-mediated carboxylation of different 2-alkynyl bromides under an atmospheric pressure of CO2 has been developed by careful tuning of different reaction parameters, including the metal, solvent, temperature, and additive. 2-Substituted 2,3-allenoic acids were afforded from primary 2-alkynyl bromides, whereas the carboxylation of secondary 2-alkynyl bromides yielded 3-alkynoic acids in decent yields. A rationale for the observed regioselectivity has been proposed.

  8. Transient neuromyopathy after bromide intoxication in a dog with idiopathic epilepsy

    PubMed Central

    2012-01-01

    A seven-year old Australian Shepherd, suffering from idiopathic epilepsy under treatment with phenobarbitone and potassium bromide, was presented with generalised lower motor neuron signs. Electrophysiology and muscle-nerve biopsies revealed a neuromyopathy. The serum bromide concentration was increased more than two-fold above the upper reference value. Clinical signs disappeared after applying diuretics and reducing the potassium bromide dose rate. This is the first case report describing electrophysiological and histopathological findings associated with bromide induced lower motor neuron dysfunction in a dog. PMID:23216950

  9. The in vitro and in vivo profile of aclidinium bromide in comparison with glycopyrronium bromide.

    PubMed

    Gavaldà, Amadeu; Ramos, Israel; Carcasona, Carla; Calama, Elena; Otal, Raquel; Montero, José Luis; Sentellas, Sonia; Aparici, Monica; Vilella, Dolors; Alberti, Joan; Beleta, Jorge; Miralpeix, Montserrat

    2014-08-01

    This study characterised the in vitro and in vivo profiles of two novel long-acting muscarinic antagonists, aclidinium bromide and glycopyrronium bromide, using tiotropium bromide and ipratropium bromide as comparators. All four antagonists had high affinity for the five muscarinic receptor sub-types (M1-M5); aclidinium had comparable affinity to tiotropium but higher affinity than glycopyrronium and ipratropium for all receptors. Glycopyrronium dissociated faster from recombinant M3 receptors than aclidinium and tiotropium but more slowly than ipratropium; all four compounds dissociated more rapidly from M2 receptors than from M3 receptors. In vitro, aclidinium, glycopyrronium and tiotropium had a long duration of action at native M3 receptors (>8 h versus 42 min for ipratropium). In vivo, all compounds were equi-potent at reversing acetylcholine-induced bronchoconstriction. Aclidinium, glycopyrronium and ipratropium had a faster onset of bronchodilator action than tiotropium. Aclidinium had a longer duration of action than glycopyronnium (time to 50% recovery of effect [t½ offset] = 29 h and 13 h, respectively); these compare with a t½ offset of 64 h and 8 h for tiotropium and ipratropium, respectively. Aclidinium was less potent than glycopyrronium and tiotropium at inhibiting salivation in conscious rats (dose required to produce half-maximal effect [ED50] = 38, 0.74 and 0.88 μg/kg, respectively) and was more rapidly hydrolysed in rat, guinea pig and human plasma compared with glycopyrronium or tiotropium. These results indicate that while aclidinium and glycopyrronium are both potent antagonists at muscarinic receptors with similar kinetic selectivity for M3 receptors versus M2, aclidinium has a longer dissociation half-life at M3 receptors and a longer duration of bronchodilator action in vivo than glycopyrronium. The rapid plasma hydrolysis of aclidinium, coupled to its kinetic selectivity, may confer a reduced propensity for systemic

  10. Bromoform formation in ozonated groundwater containing bromide and humic substances

    SciTech Connect

    Cooper, W.J.; Amy, G.L.; Moore, C.A.; Zika, R.G.

    1986-01-01

    The effect of bromide ion, organic carbon concentration (natural aquatic humic substances), pH, and solar irradiation on the formation of bromoform in ozonated groundwater has been studied. The studies were conducted on four unique samples of groundwater taken from different regions of the Biscayne Aquifer in southern Florida. All other conditions being equal, increases in bromide ion concentrations resulted in increases in CHBr/sub 3/ formation. In three of the four samples, CHBr/sub 3/ formation decreased as the pH level increased from 5 to 9. The fourth sample exhibited an opposite trend whereby the CHBr/sub 3/ concentration increased with increasing pH. Bromoform concentration increased with increased O/sub 3/ concentration over an ozone dosage range of 3.4 to 6.7 mg/L. Ozonated samples placed in sunlight immediately after ozone addition showed a decrease in the formation of CHBr/sub 3/ presumably due to the photodecomposition of HOBr/OBr.

  11. Validation of an automated fluorescein method for determining bromide in water

    USGS Publications Warehouse

    Fishman, M. J.; Schroder, L.J.; Friedman, L.C.

    1985-01-01

    Surface, atmospheric precipitation and deionized water samples were spiked with ??g l-1 concentrations of bromide, and the solutions stored in polyethylene and polytetrafluoroethylene bottles. Bromide was determined periodically for 30 days. Automated fluorescein and ion chromatography methods were used to determine bromide in these prepared samples. Analysis of the data by the paired t-test indicates that the two methods are not significantly different at a probability of 95% for samples containing from 0.015 to 0.5 mg l-1 of bromide. The correlation coefficient for the same sets of paired data is 0.9987. Recovery data, except for the surface water samples to which 0.005 mg l-1 of bromide was added, range from 89 to 112%. There appears to be no loss of bromide from solution in either type of container.Surface, atmospheric precipitation and deionized water samples were spiked with mu g l** minus **1 concentrations of bromide, and the solutions stored in polyethylene and polytetrafluoroethylene bottles. Bromide was determined periodically for 30 days. Automated fluorescein and ion chromatography methods were used to determine bromide in these prepared samples. Analysis of the data by the paired t-test indicates that the two methods are not significantly different at a probability of 95% for samples containing from 0. 015 to 0. 5 mg l** minus **1 of bromide. The correlation coefficient for the same sets of paired data is 0. 9987. Recovery data, except for the surface water samples to which 0. 005 mg l** minus **1 of bromide was added, range from 89 to 112%. Refs.

  12. The distribution of bromide in water in the Floridan aquifer system, Duval County, northeastern Florida

    USGS Publications Warehouse

    German, E.R.; Taylor, G.F.

    1995-01-01

    Although Duval County, Florida, has ample ground-water resources for public supply, the potential exists for a problem with excessive disinfectant by-products. These disinfectant by-products result from the treatment of raw water containing low concentrations of bromide and naturally occurring organic compounds. Because of this potential problem, the relation of bromide concentrations to aquifer tapped, well location and depth, and chemical characteristics of water in the Floridan aquifer system underlying Duval County were studied to determine if these relations could be applied to delineate water with low-bromide concentrations for future supplies. In 1992, water samples from 106 wells that tap the Floridan aquifer system were analyzed for bromide and major dissolved constituents. A comparison of bromide concentrations from the 1992 sampling with data from earlier studies (1979-80) indicates that higher bromide concentrations were detected during the earlier studies. The difference between the old and new data is probably because of a change in analytical methodology in the analysis of samples. Bromide concentrations exceeded the detection limit (0.10 milligrams per liter) in water from 28 of the 106 wells (26 percent) sampled in 1992. The maximum concentration was 0.56 milligrams per liter. There were no relations between bromide and major dissolved constituents, well depth, or aquifer tapped that would be useful for determining bromide concentrations. Areal patterns of bromide occurrence are not clearly defined, but areas with relatively high bromide concentrations tend to be located in a triangular area near the community of Sunbeam, Florida, and along the St. Johns River throughout Duval County.

  13. Methyl bromide fumigation of packed table grapes: Effect of shipping box on gas concentrations and phytotoxicity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Current methyl bromide schedules for table grapes to control mealybugs are approved for fruit packed in Toyon Kraft Veneer (TKV) boxes. The question arose concerning equivalence of exposure to methyl bromide if an Extruded Polystyrene (EPS) box was used in lieu of the TKV box for table grapes being ...

  14. 76 FR 7200 - Methyl Bromide; Notice of Receipt of Requests To Voluntarily Amend Registrations To Terminate...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-09

    ... Certain Soil Uses AGENCY: Environmental Protection Agency (EPA). ACTION: Notice. SUMMARY: In accordance... bromide product registrations to terminate or delete one or more soil uses. The requests would delete all methyl bromide soil uses that do not meet the definition of a ``critical use,'' a...

  15. Acrolein as Potential Alternative to Methyl Bromide in California-Grown Calla Lilies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cut flower and ornamental bulb industries rely heavily on a methyl bromide/chloropicrin (MB/Pic) mixture as a key pest management tool. The loss of methyl bromide (MB) will seriously affect the cut flower and bulb industry, and in the future, will require growers to use alternative fumigants. Theref...

  16. Enthalpies of complex formation of boron and aluminum bromides with organic bases of high donor power

    SciTech Connect

    Grigor-ev, A.A.; Kondrat'ev, Y.V.; Suvorov, A.V.

    1986-11-20

    By the calorimetric method enthalpies of complex formation were determined for boron and aluminum bromides with piperidine and hexamethylphosphoric triamide in benzene solutions and for boron bromide with pyridine in dichloroethane, and also enthalpies of solution were determined for BBr/sub 3/ and the adducts AlBr/sub 3/ x PPy and BBr/sub 2/ x Py in benzene and pyridine.

  17. Floriculture Production with Iodomethane, 1, 3-dichloropropene and Chloropicrin as an Alternatie to Methyl Bromide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cut flower growers in California have routinely used methyl bromide and chloropicrin soil fumigation to control soilborne pathogens and weeds. Because of the ban on methyl bromide production and import, alternative treatments are required. Three field trials were established to test alternative trea...

  18. Destruction of methyl bromide sorbed to activated carbon by thiosulfate and electrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide is widely used as a fumigant for post-harvest and quarantine uses at port facilities due to the low treatment times required, but it is vented to the atmosphere after its use. Due to the potential contributions of methyl bromide to stratospheric ozone depletion, technologies for the c...

  19. Perfluorooctyl bromide dispersions in aqueous media for biomedical applications.

    PubMed

    Habif, S S; Normand, P E; Oleksiak, C B; Rosano, H L

    1992-01-01

    In studying perfluorooctyl bromide (PFOB) dispersions in aqueous media, we have used two types of surfactant: egg yolk phospholipids (EYP) and polyglycerol esters (PGE). Our interest in these dispersions arises from their potential biomedical applications as imaging solutions and oxygen-carrying solutions (i.e., blood substitutes). For EYP systems, we have identified the dispersion structure as consisting of (a) PFOB droplets (250-nm diameter) stabilized by a phospholipid monolayer adsorbed irreversibly at the o/w interface and (b) small empty phospholipid vesicles. With both surfactants commercial preparations yielded stable systems, while purified samples, being non-dispersible, could not be made to act as emulsifiers. In both cases, minor components in the commercial surfactant were found to be necessary for the formation of a stable dispersion, enabling the transport of the pure surfactant to the PFOB/water interface.

  20. Tiotropium Bromide in Chronic Obstructive Pulmonary Disease and Bronchial Asthma

    PubMed Central

    Alvarado-Gonzalez, Alcibey; Arce, Isabel

    2015-01-01

    Inhaled bronchodilators are the mainstay of pharmacological treatment for stable chronic obstructive pulmonary disease (COPD), including β2-agonists and muscarinic antagonists. Tiotropium bromide, a long-acting antimuscarinic bronchodilator (LAMA), is a treatment choice for moderate-to-severe COPD; its efficacy and safety have been demonstrated in recent trials. Studies also point to a beneficial role of tiotropium in the treatment of difficult-to-control asthma and a potential function in the asthma-COPD overlap syndrome (ACOS). Combination of different bronchodilator molecules and addition of inhaled corticosteroids are viable therapeutic alternatives. A condensation of the latest trials and the rationale behind these therapies will be presented in this article. PMID:26491494

  1. Location of Bromide Ions in Tetragonal Lysozyme Crystals

    NASA Technical Reports Server (NTRS)

    Lim, Kap; Nadarajah, Arunan; Forsythe, Elizabeth L.; Pusey, Marc L.

    1998-01-01

    Anions have been shown to play a dominant role in the crystallization of chicken egg white lysozyme from salt solutions. Previous studies employing X-ray crystallography had found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. In this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from lysozyme crystal grown in bromide and chloride solutions. Five possible anion binding sites were found in this manner. Some of these sites were in pockets containing basic residues while others were near neutral, but polar, residues. The sole chloride ion binding site found in previous studies was confirmed, while four of these sites corresponded to four binding sites found for nitrate ions in monoclinic crystals. The study suggests that most of the anion binding sites in lysozyme remain unchanged, even when different anions and different crystal forms of lysozyme are employed.

  2. Unveiling Residual Molecular Binding in Triply Charged Hydrogen Bromide

    SciTech Connect

    Penent, F.; Lablanquie, P.; Palaudoux, J.; Gamblin, G.; Carniato, S.; Andric, L.; Hikosaka, Y.; Ito, K.

    2011-03-11

    We present an experimental and theoretical study of triply charged hydrogen bromide ions formed by photoionization of the inner 3d shell of Br. The experimental results, obtained by detecting the 3d photoelectron in coincidence with the two subsequent Auger electrons, are analyzed using calculated potential energy curves of HBr{sup 3+}. The competition between the short-range chemical binding potential and the Coulomb repulsion in the dissociative process is shown. Two different mechanisms are observed for double Auger decay: one, a direct process with simultaneous ejection of two Auger electrons to final HBr{sup 3+} ionic states and the other, a cascade process involving double Auger decay characterized by the autoionization of Br*{sup +} ion subsequent to the HBr{sup 2+} fragmentation.

  3. Error Evaluation of Methyl Bromide Aerodynamic Flux Measurements

    USGS Publications Warehouse

    Majewski, M.S.

    1997-01-01

    Methyl bromide volatilization fluxes were calculated for a tarped and a nontarped field using 2 and 4 hour sampling periods. These field measurements were averaged in 8, 12, and 24 hour increments to simulate longer sampling periods. The daily flux profiles were progressively smoothed and the cumulative volatility losses increased by 20 to 30% with each longer sampling period. Error associated with the original flux measurements was determined from linear regressions of measured wind speed and air concentration as a function of height, and averaged approximately 50%. The high errors resulted from long application times, which resulted in a nonuniform source strength; and variable tarp permeability, which is influenced by temperature, moisture, and thickness. The increase in cumulative volatilization losses that resulted from longer sampling periods were within the experimental error of the flux determination method.

  4. Perfluorooctyl bromide dispersions in aqueous media for biomedical applications.

    PubMed

    Habif, S S; Normand, P E; Oleksiak, C B; Rosano, H L

    1992-01-01

    In studying perfluorooctyl bromide (PFOB) dispersions in aqueous media, we have used two types of surfactant: egg yolk phospholipids (EYP) and polyglycerol esters (PGE). Our interest in these dispersions arises from their potential biomedical applications as imaging solutions and oxygen-carrying solutions (i.e., blood substitutes). For EYP systems, we have identified the dispersion structure as consisting of (a) PFOB droplets (250-nm diameter) stabilized by a phospholipid monolayer adsorbed irreversibly at the o/w interface and (b) small empty phospholipid vesicles. With both surfactants commercial preparations yielded stable systems, while purified samples, being non-dispersible, could not be made to act as emulsifiers. In both cases, minor components in the commercial surfactant were found to be necessary for the formation of a stable dispersion, enabling the transport of the pure surfactant to the PFOB/water interface. PMID:1369226

  5. N-(2-Bromo­benz­yl)cinchoninium bromide

    PubMed Central

    Skórska-Stania, Agnieszka; Jezierska-Zięba, Magdalena; Kąkol, Barbara; Fedoryński, Michał; Oleksyn, Barbara J.

    2012-01-01

    The title compound {systematic name: 1-(2-bromo­benz­yl)-5-ethenyl-2-[hy­droxy(quinolin-4-yl)meth­yl]-1-aza­bicyclo­[2.2.2]octan-1-ium bromide}, C26H28BrN2O+·Br−, is a chiral quater­nary ammonium salt of one of the Cinchona alkaloids. The planes of the quinoline and of the bromo­benzyl substituent are inclined to one another by 9.11 (9)°. A weak intra­molecular C—H⋯O hydrogen bond occurs. The crystal structure features strong O—H⋯Br hydrogen bonds and weak C—H⋯Br inter­actions. PMID:22969676

  6. Combined intranasal ipratropium bromide and oxymetazoline in experimental rhinovirus infection.

    PubMed

    Pitkäranta, A; Wecker, M T; Korts, D C; Hayden, F G

    1998-01-01

    The topical anticholinergic ipratropium bromide and topical decongestant oxymetazoline were tested to determine whether oxymetazoline alone and the combination were well tolerated and reduced rhinorrhea and middle ear pressure abnormalities during experimental rhinovirus infection. The study was double-bind, placebo-controlled, and double dummy in design. Healthy volunteers (n = 109) with low serum neutralizing antibody titer (< or = 1:2) were. Treatments inoculated with rhinovirus (type 39 or Hank's strain) and randomized to treatment with ipra-tropium bromide 0.06% two sprays per nostril (84 micrograms per treatment) and oxymetazoline 0.05% two sprays per nostril, oxymetazoline alone, or placebo. Treatments were self administered twice daily for 5 days beginning 1 day after rhinovirus inoculation. The overall infection rate was 83% and of those infected, 88% felt that they had a cold. During the 3-hour period after dosing, the increase in nasal discharge was significantly lower in the combined ipratropium and oxymetazoline (0.13 +/- 0.17 gm/3 hr, mean +/- SE) than after oxymetazoline alone (0.60 +/- 0.18 gm/3 hr) or vehicle (0.73 +/- 0.18 gm/3 hr). Over the 5-day observation period, total daily nasal discharge also tended to be lower in the ipratropium plus oxymetazoline group (3.67 +/- 0.70 gm/24 hr, mean +/- SE) compared to oxymetazoline (5.61 +/- 0.73: 35% reduction) or the vehicle (5.04 +/- 0.73; 27% reduction) recipients, but the differences were not statistically significant. Subjective assessments of rhinorrhea indicated that the severity of rhinorrhea was significantly better among patients receiving oxymetazoline alone or with ipratropium compared to the vehicle. No significant difference in the cumulative frequencies of middle ear pressure abnormalities (27-31%) were found among the treatment groups. Oxymetazoline does not consistently stimulate or decrease nasal mucus production, and ipratropium added to oxymetazoline is well tolerated and reduces

  7. Comparative mobility of sulfonamides and bromide tracer in three soils

    USGS Publications Warehouse

    Kurwadkar, S.T.; Adams, C.D.; Meyer, M.T.; Kolpin, D.W.

    2011-01-01

    In animal agriculture, sulfonamides are one of the routinely used groups of antimicrobials for therapeutic and sub-therapeutic purposes. It is observed that, the animals when administered the antimicrobials, often do not completely metabolize them; and excrete the partially metabolized forms into the environment. Due to the continued use of antimicrobials and disposal of untreated waste, widespread occurrence of partially metabolized antimicrobials in aquatic and terrestrial environments has been reported in various scientific journals. In this research, the mobility of two sulfonamides - sulfamethazine (SMN), sulfathiazole (STZ) and a conservative bromide tracer was investigated in three soils collected from regions in the United States with large number of concentrated animal-feed operations. Results of a series of column studies indicate that the mobility of these two sulfonamides was dependent on pH, soil charge density, and contact time. At low pH and high charge density, substantial retention of sulfonamides was observed in all three soils investigated, due to the increased fraction of cationic and neutral forms of the sulfonamides. Conversely, enhanced mobility was observed at high pH, where the sulfonamides are predominantly in the anionic form. The results indicate that when both SMN and STZ are predominantly in anionic forms, their mobility approximates the mobility of a conservative bromide tracer. This observation is consistent for the mobility of both SMN and STZ individually, and also in the presence of several other antimicrobials in all three soils investigated. Higher contact time indicates lower mobility due to increased interaction with soil material. ?? 2011.

  8. Action of pinaverium bromide, a calcium-antagonist, on gastrointestinal motility disorders.

    PubMed

    Christen, M O

    1990-01-01

    1. The evidence reviewed here indicates that pinaverium bromide (Dicetel) relaxes gastrointestinal (GI) structures primarily by inhibiting Ca2+ influx through potential-dependent channels of surface membranes of smooth muscle cells. 2. The in vivo selectivity of pinaverium bromide for the GI tract appears to be due mainly to its pharmacokinetic properties. Because of its low absorption (typical for quaternary ammonium compounds) and marked hepatobiliary excretion, most of the orally-administered dose of pinaverium bromide remains in the GI tract. 3. Orally-administered pinaverium bromide does not elicit adverse cardiovascular side-effects at doses that effectively relieve GI spasm, pain, transit disturbances and other symptoms related to motility disorders. 4. Pinaverium bromide is the only Ca2(+)-antagonist with known therapeutic efficacy in the treatment of irritable bowel syndrome and certain other functional intestinal disorders. PMID:2177709

  9. X-Ray absorption spectroscopy investigation of 1-alkyl-3-methylimidazolium bromide salts

    SciTech Connect

    D'Angelo, Paola; Zitolo, Andrea; Migliorati, Valentina; Bodo, Enrico; Caminiti, Ruggero; Aquilanti, Giuliana; Hazemann, Jean Louis; Testemale, Denis; Mancini, Giordano

    2011-08-21

    X-ray absorption spectroscopy (XAS) has been used to unveil the bromide ion local coordination structure in 1-alkyl-3-methylimidazolium bromide [C{sub n}mim]Br ionic liquids (ILs) with different alkyl chains. The XAS spectrum of 1-ethyl-3-methylimidazolium bromide has been found to be different from those of the other members of the series, from the butyl to the decyl derivatives, that have all identical XAS spectra. This result indicates that starting from 1-buthyl-3-methylimidazolium bromide the local molecular arrangement around the bromide anion is the same independently from the length of the alkyl chain, and that the imidazolium head groups in the liquid ILs with long alkyl chains assume locally the same orientation as in the [C{sub 4}mim]Br crystal. With this study we show that the XAS technique is an effective direct tool for unveiling the local structural arrangements around selected atoms in ILs.

  10. Methyl bromide emissions from a covered field: I. Experimental conditions and degradation in soil

    SciTech Connect

    Yates, S.R.; Gan, J.; Ernst, F.F.

    1996-01-01

    An experiment is described to investigate the environmental fate and transport of methyl bromide in agricultural systems. The experiment was designed to determine the dynamics of methyl bromide movement through soil, degradation, and total emissions to the atmosphere. This is of particular interest because it will allow an assessment of the environmental impacts (i.e., stratospheric ozone depletion) resulting from the agricultural use of methyl bromide. Methyl bromide was applied at a rate of 843 kg in a 3.5-ha (i.e., 240 kg/ha) field at a depth of 0.25 m and covered with a sheet of 1-mil polyethylene plastic. The maximum methyl bromide concentration in the atmosphere occurred at night between 0200 and 0600 h. During the first 3 d of the experiment, the maximum daily concentrations at 0.2 m above the soil surface were 30, 5, and 1 mg/(m{sup 3} of air), respectively. The trend of reduced emissions with time continued until the plastic was removed, when a momentary increase in the methyl bromide emissions occurred. The maximum soil gas concentration 24 h after injection was 30 g/m{sup 3} located at a 0.25-m depth. When the plastic was removed from the field (at 5.6 d), the maximum soil gas concentration was approximately 2 g/m{sup 3} at a 0.5-m depth. A mass-difference method for estimating the total methyl bromide emissions from the soil, based on degradation of methyl bromide to Br{sup -}, indicates that approximately 39% or 325 kg ({+-} 164 kg) of the applied methyl bromide was converted to Br{sup -} and, therefore, 61% or 518 kg ({+-} 164 kg) was lost via volatilization. 16 refs., 11 figs., 2 tabs.

  11. Palladium-Catalyzed Alkoxycarbonylation of Unactivated Secondary Alkyl Bromides at Low Pressure.

    PubMed

    Sargent, Brendon T; Alexanian, Erik J

    2016-06-22

    Catalytic carbonylations of organohalides are important C-C bond formations in chemical synthesis. Carbonylations of unactivated alkyl halides remain a challenge and currently require the use of alkyl iodides under harsh conditions and high pressures of CO. Herein we report a palladium-catalyzed alkoxycarbonylation of secondary alkyl bromides that proceeds at low pressure (2 atm CO) under mild conditions. Preliminary mechanistic studies are consistent with a hybrid organometallic-radical process. These reactions efficiently deliver esters from unactivated alkyl bromides across a diverse range of substrates and represent the first catalytic carbonylations of alkyl bromides with carbon monoxide.

  12. The action of structural analogues of ethidium bromide on the mitochondrial genome of yeast.

    PubMed

    Hall, R M; Mattick, J S; Nagley, P; Cobon, G S; Eastwood, F W; Linnane, A W

    1977-12-01

    We have studied the effects on the yeast mitochondrial genome of four analogues of ethidium bromide, in which the phenyl moieyt has been replaced by linear alkyl chains of lengths varying from seven to fifteen carbon atoms. These analogues are more efficient than ethidium bromide in inducing petite mutants in Saccharomyces cervisiae. The drugs also cause a loss of mtDNA from the cells in vivo; however these analogues are in fact less effective inhibitors of mitochondrial DNA replication per se, as shown by direct in vitro studies. It is concluded that these analogues are more efficient than ethidium bromide in causing the fragmentation of mitochondrial DNA in S. cervisiae. PMID:339057

  13. Evaluation of alkali bromide salts for potential pyrochemical applications

    SciTech Connect

    Tripathy, P.K.; Gutknecht, T.Y.; Herrmann, S.D.; Fredrickson, G.L.; Lister, T.E.

    2013-07-01

    Transient techniques were employed to study the electrochemical behavior, reduction mechanism and transport properties of REBr{sub 3} (RE - La, Nd and Gd) in pure LiBr, LiBr-KBr (eutectic) and LiBr-KBr-CsBr (eutectic) melts. Gd(III) showed a reversible single step soluble-insoluble exchange phenomenon in LiBr melt at 973 K. Although La (III), Nd(III) and Gd(III) ions showed reversible behavior in eutectic LiBr-KBr melts, these ions showed a combination of temperature dependent reversible and pseudo-reversible behavior. While both La(III) and Gd(III) showed one step reduction, the reduction of Nd(III) was observed to be a two step process. La metal could be electrodeposited from the ternary electrolyte at a temperature of 673 K. Various electrochemical measurements suggest that both binary and ternary bromide melts can potentially be used to electro-deposit high purity RE metals at comparatively lower operating temperatures. (authors)

  14. Atmospheric methyl bromide: Trends and global mass balance

    SciTech Connect

    Khalil, M.A.K.; Rasmussen, R.A.; Gunawardena, R. )

    1993-02-20

    Atmospheric methyl bromide is of considerable environmental importance as the largest reservoir of gaseous bromine in the atmosphere. Bromine gases can catalytically destroy stratospheric ozone. Since agricultural activities, automobiles, biomass burning, and other human activities produce CH[sub 3]Br, it is of interest to know its global mass balance and particularly the specific sources and sinks. In this paper the authors provide a decadal time series of global CH[sub 3]Br concentrations in the Earth's atmosphere. The data show that average concentrations are about 10 pptv and during the last 4 years may be increasing at 0.3 [plus minus] 0.1 pptv/yr (3%/yr [plus minus] 1%/yr). They estimate that the atmospheric lifetime of CH[sub 3]Br that is due to reaction with OH, is about 2 years, resulting in a calculated global emission rate of about 100 Gy/yr. Ocean supersaturations of 140-180% are observed, and atmospheric concentrations over the open oceans are higher than at comparably located coastal sites. The ocean source is estimated to be about 35 Gg/yr. The remaining emissions must come from other natural sources and anthropogenic activities. The results are based on some 2,200 samples obtained over more than a decade. Mass balance calculations explain most aspects of the present data but other implications are not easily reconciled, leaving open the possibility of undiscovered sources and sinks. 20 refs., 5 figs., 4 tabs.

  15. Bioreactors for removing methyl bromide following contained fumigations

    USGS Publications Warehouse

    Miller, L.G.; Baesman, S.M.; Oremland, R.S.

    2003-01-01

    Use of methyl bromide (MeBr) as a quarantine, commodity, or structural fumigant is under scrutiny because its release to the atmosphere contributes to the depletion of stratospheric ozone. A closed-system bioreactor consisting of 0.5 L of a growing culture of a previously described bacterium, strain IMB-1, removed MeBr (> 110 ??mol L-1) from recirculating air. Strain IMB-1 grew slowly to high cell densities in the bioreactor using MeBr as its sole carbon and energy source. Bacterial oxidation of MeBr produced CO2 and hydrobromic acid (HBr), which required continuous neutralization with NaOH for the system to operate effectively. Strain IMB-1 was capable of sustained oxidation of large amounts of MeBr (170 mmol in 46 d). In an open-system bioreactor (10-L fermenter), strain IMB-1 oxidized a continuous supply of MeBr (220 ??mol L-1 in air). Growth was continuous, and 0.5 mol of MeBr was removed from the air supply in 14 d. The specific rate of MeBr oxidation was 7 ?? 10-16 mol cell-1 h-1. Bioreactors such as these can therefore be used to remove large quantities of contaminant MeBr, which opens the possibility of biodegradation as a practical means for its disposal.

  16. Olfactory stimuli provoke diffuse esophageal spasm: reversal by ipratropium bromide.

    PubMed

    Triadafilopoulos, G; Tsang, H P

    1996-10-01

    Diffuse esophageal spasm (DES) is a motor disorder of the esophageal smooth muscle characterized by multiple spontaneous contractions and by swallow-induced contractions that are of simultaneous onset, large amplitude, long duration, and repetitive occurrence. Although the pathogenesis of DES is unknown, provocative studies with cholinergic stimulation, esophageal balloon distention, or acid instillation have suggested involvement of both sensory and motor mechanisms. This report describes a patient with DES who would predictably become symptomatic with dysphagia and chest pain upon inhalation of perfume or other strong odors. Using esophageal scintigraphy to quantitate and analyze esophageal transit in this patient, we report for the first time that olfactory stimulation triggers episodes of DES and that such phenomena are mediated through the vagus nerve, because they can be ameliorated by the administration of ipratropium bromide. These observations suggest a new (sensory) pathway for the induction of DES and raise the intriguing possibility that inhaled anticholinergics may have a therapeutic role in the management of spastic esophageal motility disorders.

  17. Improved spectrometric characteristics of thallium bromide nuclear radiation detectors

    NASA Astrophysics Data System (ADS)

    Hitomi, K.; Murayama, T.; Shoji, T.; Suehiro, T.; Hiratate, Y.

    1999-06-01

    Thallium bromide (TlBr) is a compound semiconductor with a high atomic number and wide band gap. In this study, nuclear radiation detectors have been fabricated from the TlBr crystals. The TlBr crystals were grown by the horizontal travelling molten zone (TMZ) method using the materials purified by many pass zone refining. The crystals were characterized by measuring the resistivity, the mobility-lifetime ( μτ) product and the energy required to create an electron-hole pair (the ɛ value). Improved energy resolution has been obtained by the TlBr radiation detectors. At room temperature the full-width at half-maximum (FWHM) for the 59.5, 122 and 662 keV γ-ray photo peak obtained from the detectors were 3.3, 8.8 and 29.5 keV, respectively. By comparing the saturated peak position of the TlBr detector with that of the CdTe detector, the ɛ value has been estimated to be about 5.85 eV for the TlBr crystal.

  18. Nanocapsules of perfluorooctyl bromide for theranostics: from formulation to targeting

    NASA Astrophysics Data System (ADS)

    Diou, O.; Fattal, E.; Payen, T.; Bridal, S. L.; Valette, J.; Tsapis, N.

    2014-03-01

    The need to detect cancer at its early stages, as well as, to deliver chemotherapy to targeted site motivates many researchers to build theranostic platforms which combine diagnostic and therapy. Among imaging modalities, ultrasonography and Magnetic Resonance Imaging (MRI) are widely available, non invasive and complement each other. Both techniques often require the use of contrast agents. We have developed nanocapsules of perfluorooctyl bromide as dual contrast agent for both imaging modalities. The soft, amorphous polymer shell provides echogenicity, while the high-density perfluorinated liquid core allows detection by 19F MRI. We have used a shell of poly(lactide-co-glycolide) (PLGA) since this polymer is biodegradable, biocompatible and can be loaded with drugs. These capsules were shown to be efficient in vitro as contrast agents for both 19F MRI and ultrasonography. In addition, for in vivo applications a poly(ethyleneglycol) (PEG) coating promotes stability and prolonged circulation. Being stealth, nanocapsule can accumulate passively into implanted tumors by the EPR effect. We will present nanocapsule formulation and characterization, and will show promising in vivo results obtained for both ultrasonography and 19F MRI.

  19. Spectrometric study on the interaction of dodecyltrimethylammonium bromide with curcumin.

    PubMed

    Ke, Dan; Wang, Xiaoyong; Yang, Qianqian; Niu, Yumeng; Chai, Shaohu; Chen, Zhiyun; An, Xueqin; Shen, Weiguo

    2011-12-01

    The interaction between dodecyltrimethylammonium bromide (DTAB) and curcumin has been studied in pH 5.0 sodium phosphate buffer using absorption and fluorescence measurements. With increasing DTAB concentration (C(DTAB)) from 0 to 20 mM, the absorption peak of curcumin at 430 nm, corresponding to the conjugated structure of curcumin, first weakens gradually into a shoulder but increases back into one peak with much higher absorption intensity. On the contrary, as C(DTAB) increases, the initial small absorption shoulder of curcumin at 355 nm, corresponding to the feruloyl unit of curcumin, first increases gradually into a clear peak but decreases back into one shoulder until almost disappeared finally. By remaining at nearly the same wavelength, the fluorescence of curcumin first decreases at C(DTAB) lower than 5 mM and then increases gradually up to C(DTAB) = 10 mM, which is followed by sharp increases of fluorescence intensity with marked blue-shifts at higher C(DTAB). The values of anisotropy and microviscosity of curcumin obtained from the fluorescence polarization technique also showed pronounced changes at different surfactant concentrations. The interaction mechanisms of DTAB with curcumin have been presented at low, intermediate, and high surfactant concentrations, which is relating to interaction forces, surfactant aggregations, as well as structural alterations of curcumin.

  20. Evaluation of Alkali Bromide Salts for Potential Pyrochemical Applications

    SciTech Connect

    Prabhat K. Tripathy; Steven D. Herrmann; Guy L. Fredrickson; Tedd E. Lister; Toni Y. Gutknecht

    2013-10-01

    Transient techniques were employed to study the electrochemical behavior, reduction mechanism and transport properties of REBr3 (RE - La, Nd and Gd) in pure LiBr, LiBr-KBr (eutectic) and LiBr-KBr-CsBr (eutectic) melts. Gd(III) showed a reversible single step soluble-insoluble exchange phenomenon in LiBr melt at 973K. Although La (III), Nd(III) and Gd(III) ions showed reversible behavior in eutectic LiBr-KBr melts, these ions showed a combination of temperature dependent reversible and pseudo-reversible behavior. While both La(III) and Gd(III) showed one step reduction, the reduction of Nd(III) was observed to be a two step process. La metal could be electrodeposited from the ternary electrolyte at a temperature of 673K. Various electrochemical measurements suggest that both binary and ternary bromide melts can potentially be used to electrodeposit high purity RE metals at comparatively lower operating temperatures.

  1. Bacterial oxidation of methyl bromide in Mono Lake, California

    USGS Publications Warehouse

    Connell, T.L.; Joye, S.B.; Miller, L.G.; Oremland, R.S.

    1997-01-01

    The oxidation of methyl bromide (MeBr) in the water column of Mono Lake, CA, was studied by measuring the formation of H14CO3 from [14C]MeBr. Potential oxidation was detected throughout the water column, with highest rates occurring in the epilimnion (5-12 m depth). The oxidation of MeBr was eliminated by filter-sterilization, thereby demonstrating the involvement of bacteria. Vertical profiles of MeBr activity differed from those obtained for nitrification and methane oxidation, indicating that MeBr oxidation is not simply a co-oxidation process by either nitrifiers or methanotrophs. Furthermore, specific inhibitors of methane oxidation and/or nitrification (e.g., methyl fluoride, acetylene, allyl sulfide) had no effect upon the rate of MeBr oxidation in live samples. Of a variety of potential electron donors added to Mono Lake water, only trimethylamine resulted in the stimulation of MeBr oxidation. Cumulatively, these results suggest that the oxidation of MeBr in Mono Lake waters is attributable to trimethylamine-degrading methylotrophs. Neither methyl chloride nor methanol inhibited the oxidation of [14C]MeBr in live samples, indicating that these bacteria directly oxidized MeBr rather than the products of MeBr nucleophilic substitution reactions.

  2. Polarization effects in thallium bromide x-ray detectors

    SciTech Connect

    Kozorezov, A.; Wigmore, J. K.; Gostilo, V.; Shorohov, M.; Owens, A.; Quarati, F.; Webb, M. A.

    2010-09-15

    We present the results of a detailed experimental study of polarization effects in thallium bromide planar x-ray detectors. Measurements were carried out in the range 10-100 keV by scanning a highly focused x-ray beam, 50 {mu}m in diameter, from a synchrotron source across the detector. Above a certain radiation threshold the detector response showed a systematic degradation of its spectroscopic characteristics, peak channel position, peak height, and energy resolution. Using a pump-and-probe technique, we studied the dynamics of spectral degradation, the spatial extent and relaxation of the polarized region, and the dependence of the detector response on bias voltage and temperature. For comparison, we modeled polarization effects induced by the charging of traps by both electrons and holes using a model based on recent theoretical work of Bale and Szeles. We calculated the charge collection efficiency and spectral line shapes as functions of exposure time, beam position, count rate, and photon energy, and obtained credible agreement with experimental results.

  3. Fabrication of double-sided thallium bromide strip detectors

    NASA Astrophysics Data System (ADS)

    Hitomi, Keitaro; Nagano, Nobumichi; Onodera, Toshiyuki; Kim, Seong-Yun; Ito, Tatsuya; Ishii, Keizo

    2016-07-01

    Double-sided strip detectors were fabricated from thallium bromide (TlBr) crystals grown by the traveling-molten zone method using zone-purified materials. The detectors had three 3.4-mm-long strips with 1-mm widths and a surrounding electrode placed orthogonally on opposite surfaces of the crystals at approximately 6.5×6.5 mm2 in area and 5 mm in thickness. Excellent charge transport properties for both electrons and holes were observed from the TlBr crystals. The mobility-lifetime products for electrons and holes in the detector were measured to be ~3×10-3 cm2/V and ~1×10-3 cm2/V, respectively. The 137Cs spectra corresponding to the gamma-ray interaction position were obtained from the detector. An energy resolution of 3.4% of full width at half maximum for 662-keV gamma rays was obtained from one "pixel" (an intersection of the strips) of the detector at room temperature.

  4. Locations of Bromide Ions in Tetragonal Lysozyme Crystals

    NASA Technical Reports Server (NTRS)

    Lim, Kap; Nadarajah, Arunan; Forsythe, Elizabeth L.; Pusey, Marc L.

    1998-01-01

    Anions have been shown to play a dominant role in the crystallization of chicken egg-white lysozyme from salt solutions. Previous studies employing X-ray crystallography have found one chloride ion binding site in the tetragonal crystal form of the protein and four nitrate ion binding sites in the monoclinic form. In this study the anion positions in the tetragonal form were determined from the difference Fourier map obtained from lysozyme crystals grown in bromide and chloride solutions. Five possible anion-binding sites were found in this manner. Some of these sites were in pockets containing basic residues while others were near neutral, but polar, residues. The sole chloride ion binding site found in previous studies was confirmed, while four further sites were found which corresponded to the four binding sites found for nitrate ions in monoclinic crystals. The study suggests that most of the anion-binding sites in lysozyme remain unchanged even when different anions and different crystal forms of lysozyme are employed.

  5. Reactive films for mitigating methyl bromide emissions from fumigated soil.

    PubMed

    Xuan, Richeng; Ashworth, Daniel J; Luo, Lifang; Yates, Scott R

    2011-03-15

    Emissions of methyl bromide (MeBr) from agricultural fumigation can lead to depletion of the stratospheric ozone layer, and so its use is being phased out. However, as MeBr is still widely used under Critical Use Exemptions, strategies are still required to control such emissions. In this work, novel reactive films (RFs) were designed and their efficacy in limiting loss of MeBr from soil was tested. A reactive layer, containing dry ammonium thiosulfate (ATS), was sandwiched between two layers of plastic film, the lower layer being HDPE (high-density polyethylene film, which is permeable to MeBr) and the upper layer HDPE or VIF (virtually impermeable film). MeBr diffusion through, and transformation by, the RFs were tested in a stainless-steel permeability cell. Although ineffective when dry, the RFs substantially depleted MeBr when activated with water to produce ATS solution. MeBr half-life (t(1/2)) was around 9.0 h at 20 °C in the presence of activated RF, and was sensitive to temperature (t(1/2) 15.7 and 2.9 h at 10 and 40 °C, respectively). When the upper film layer was VIF, less than 0.15% of the added MeBr diffused through the film, with the remainder being transformed within the reactive layer. These findings indicate that such films have good potential to reduce MeBr loss from fumigated soils to the atmosphere.

  6. Chloride, bromide and iodide scintillators with europium doping

    DOEpatents

    Zhuravleva, Mariya; Yang, Kan

    2014-08-26

    A halide scintillator material is disclosed where the halide may comprise chloride, bromide or iodide. The material is single-crystalline and has a composition of the general formula ABX.sub.3 where A is an alkali, B is an alkali earth and X is a halide which general composition was investigated. In particular, crystals of the formula ACa.sub.1-yEu.sub.yI.sub.3 where A=K, Rb and Cs were formed as well as crystals of the formula CsA.sub.1-yEu.sub.yX.sub.3 (where A=Ca, Sr, Ba, or a combination thereof and X=Cl, Br or I or a combination thereof) with divalent Europium doping where 0.ltoreq.y.ltoreq.1, and more particularly Eu doping has been studied at one to ten mol %. The disclosed scintillator materials are suitable for making scintillation detectors used in applications such as medical imaging and homeland security.

  7. The influence of perchlorates on the fluorescence quenching of 9,10-dichloroanthracene by bromide salts in acetone

    NASA Astrophysics Data System (ADS)

    Mac, Marek; Tokarczyk, Bogdan

    1999-05-01

    Fluorescence quenching of 9,10-dichloroanthracene by lithium bromide and tetra- n-butylammonium bromide in acetone has been investigated in the presence of perchlorate salts. In the presence of LiBr, the Stern-Volmer (S-V) plots exhibit downward curvatures indicating that two species are responsible for the quenching process, namely free bromide anions and lithium bromide ion pairs. The addition of a perchlorate salt modifies the S-V dependencies due to the influence of perchlorates on the degree of lithium bromide dissociation. The association constant of lithium bromide has been determined by conductivity measurements and it agrees well with the estimates made from the fluorescence quenching measurements. The mechanism of fluorescence quenching by lithium bromide is discussed on the basis of electron transfer and the heavy-atom effect.

  8. BROMIDE'S EFFECT ON DBP FORMATION, SPECIATION, AND CONTROL: PART 1, OZONATION

    EPA Science Inventory

    The effect of variable ozone dosage and bromide concentration on the formation of organic disinfection byproducts (DBPs) and bromate were evaluated. Low ozone dosages resulted in oxidation of organic precursors, yielding decreases in the formation potential for total trihalometha...

  9. CHLORPYRIFOS TRANSFORMATION BY AQUEOUS CHLORINE IN THE PRESENCE OF BROMIDE AND NATURAL ORGANIC MATTER

    EPA Science Inventory

    The aqueous chlorination of chlorpyrifos (CP) was investigated in the presence of bromide and natural organic matter (NOM), which were identified as naturally occurring aqueous constituents that could impact CP transformation rates to the toxic product chlorpyrifos oxon (CPO). Br...

  10. Uptake and excretion of ( UC)methyl bromide as influenced by exposure concentration

    SciTech Connect

    Medinsky, M.A.; Dutcher, J.S.; Bond, J.A.; Henderson, R.F.; Mauderly, J.L.; Snipes, M.B.; Mewhinney, J.A.; Cheng, Y.S.; Birnbaum, L.S.

    1985-01-01

    Uptake of methyl bromide and pathways for excretion of UC were investigated in male Fischer-344 rats after nose-only inhalation of 50, 300, 5700, or 10,400 nmol (1.6 to 310 ppm) of ( UC)methyl bromide/liter of air for 6 hr. Fractional uptake of methyl bromide decreased at the highest concentrations, 5700 and 10,400 nmol/liter, with 37 and 27% of the inhaled methyl bromide absorbed, respectively, compared to 48% at the lower levels. Total methyl bromide absorbed was 9 or 40 mol/kg body wt after exposure to 50 or 300 nmol/liter, respectively. Elimination of UC was linearly related to the amount of methyl bromide absorbed as determined from urine, feces, expired CO2, and parent compound collected for 66 hr after the end of exposure. Exhaled UCO2 was the dominant route of excretion, with from 1.2 to 110 mol (50% of amount absorbed) exhaled, and was described by a two-component negative exponential function; 85% was exhaled with t1/2 of 4 hr, and the remaining 15% was exhaled with a t1/2 of 17 hr. The rate of exhalation of UCO2 was not affected by the amount of ( UC)methyl bromide absorbed. From 0.4 to 54 mol was excreted in urine (20% of amount absorbed). The half-time for excretion of UC in urine was approximately 10 hr, and the rate of excretion was not dependent on the amount of ( UC)methyl bromide absorbed. Little UC was exhaled as methyl bromide (<4% of the dose) or excreted in feces (<2%). At the end of 66 hr, 25% of the UC absorbed remained in the rats. Liver, kidneys, adrenals, lungs, thymus, and turbinates (maxilloturbinates, ethmoturbinates, and nasal epithelial membrane) contained the highest concentrations of UC. Results indicated that uptake of inhaled methyl bromide could be saturated. Any ( UC)methyl bromide equivalents absorbed, however, would be excreted by concentration-independent mechanisms. 20 references, 5 figures, 4 tables.

  11. Characterizing unsaturated solute transport by simultaneous use of dye and bromide

    NASA Astrophysics Data System (ADS)

    Öhrström, P.; Hamed, Y.; Persson, M.; Berndtsson, R.

    2004-04-01

    Variability in solute transport properties in the unsaturated zone is of growing concern due to environmental hazards. By combining dye and salt tracers, a detailed description of the solute transport can be made in both time and space. In this paper, qualitative and quantitative effects of preferential flow were investigated in a sandy loam. The experimental site was equipped with 64 TDR probes. The plot was irrigated with pure water for 12 days to achieve steady state conditions. Then the plot was irrigated with a solution containing a dye tracer and KBr over three days. During the experiment, bromide concentration and soil moisture were measured hourly by the TDR probes. On the day following the last day of irrigation, a trench was dug and 14 vertical slices were excavated and photographed. A Sigma Probe (SP) was used to investigate the bromide concentration in an individual finger. The SP is a new dielectric measuring technique that gives readings of soil solution electrical conductivity. The dye photographs provided visualization of finger flow. Horizontal flow was evident in the E horizon at 0.3-0.4 m depth. Also the bromide concentration was elevated at these depths. The occurrences of high bromide as measured by the SP concentration corresponded fairly well to the dye patterns. The visible lower limit of dye stained soil corresponded to a bromide concentration of 0.10. A comparison between the bromide and dye penetration showed that the retardation factor of the dye as compared to bromide was 1.5. This is within the range reported by other authors and shows that the SP can be a useful tool to investigate the retardation of dyes as compared to bromide.

  12. The effect of pinaverium bromide (LA 1717) on the lower oesophageal sphincter.

    PubMed

    Wöltje, M; Huchzermeyer, H

    1982-01-01

    An acute, double-blind study was carried out in 8 healthy male volunteers to investigate any effect of a new antispasmodic, pinaverium bromide, compared with placebo on the lower oesophageal sphincter. Manometric measurements showed no significant differences in resting pressures either after placebo or a therapeutic dose (200 mg) of pinaverium bromide, suggesting that the active drug does not cause any impairment of function of the lower oesophageal sphincter. PMID:7128186

  13. Influence of bromide on the performance of the amphipod Hyalella azteca in reconstituted waters

    USGS Publications Warehouse

    Ivey, Chris D.; Ingersoll, Christopher G.

    2016-01-01

    Poor performance of the amphipod Hyalella azteca has been observed in exposures using reconstituted waters. Previous studies have reported success in H. azteca water-only exposures with the addition of relatively high concentrations of bromide. The present study evaluated the influence of lower environmentally representative concentrations of bromide on the response ofH. azteca in 42-d water-only exposures. Improved performance of H. azteca was observed in reconstituted waters with >0.02 mg Br/L.

  14. Reactions between a superoxide anion and alkyl bromides in dimethyl sulfoxide

    NASA Astrophysics Data System (ADS)

    Pomeshchenko, A. I.; Efimova, I. V.; Dmitruk, A. F.; Zarechnaya, O. M.; Opeida, I. A.

    2011-10-01

    The activation parameters of the reactions between a superoxide anion (O{2/·-}) and alkyl bromides are measured. An ab initio study of the transition states for various mechanisms of this reaction is performed. The mechanism of radical separation in a polar solvent becomes competitive upon an increase in the number of alkyl groups in an alkyl bromide molecule and depends on their arrangement relative to a reaction center.

  15. Stabilized thallium bromide radiation detectors and methods of making the same

    SciTech Connect

    Leao, Cedric Rocha; Lordi, Vincenzo

    2015-11-24

    According to one embodiment, a crystal includes thallium bromide (TlBr), one or more positively charged dopants, and one or more negatively charged dopants. According to another embodiment, a system includes a monolithic crystal including thallium bromide (TlBr), one or more positively charged dopants, and one or more negatively charged dopants; and a detector configured to detect a signal response of the crystal.

  16. Short gold nanorod growth revisited: the critical role of the bromide counterion.

    PubMed

    Si, Satyabrata; Leduc, Cecile; Delville, Marie-Hélène; Lounis, Brahim

    2012-01-16

    A one-step, surfactant-assisted, seed-mediated method has been utilized for the growth of short gold nanorods with reasonable yield by modifying an established synthesis protocol. Among the various parameters that influence nanorod growth, the impact of the bromide counterion has been closely scrutinized. During this study it has been shown that, irrespective of its origin, the bromide counterion [cetyltrimethylammonium bromide (CTAB) or NaBr] plays a crucial role in the formation of nanorods in the sense that there is a critical [Br(-)]/[Au(3+)] ratio (around 200) to achieve nanorods with a maximum aspect ratio. Beyond this value, bromide can be considered as a poisoning agent unless shorter nanorods are required. The use of AgNO(3) helps in symmetry breaking for gold nanorod growth, whereas the bromide counterion controls the growth kinetics by selective adsorption on the facets of the growth direction. Thus, a proper balance between bromide ions and gold cations is also one of the necessary parameters for controlling the size of the gold nanorods; this has been discussed thoroughly. The results have been discussed based on their absorption spectra and finally shape evolution has been confirmed by TEM. Due to their efficient absorption in the near-IR region, these short nanorods were used in photothermal imaging of living COS-7 cells with improved signal-to-background ratios.

  17. Effect of ferric and bromide ions on the formation and speciation of disinfection byproducts during chlorination.

    PubMed

    Liu, Shaogang; Zhu, Zhiliang; Qiu, Yanling; Zhao, Jianfu

    2011-01-01

    The effects of ferric ion, pH, and bromide on the formation and distribution of disinfection byproducts (DBPs) during chlorination were studied. Two raw water samples from Huangpu River and Yangtze River, two typical drinking water sources of Shanghai, were used for the investigation. Compared with the samples from Huangpu River, the raw water samples from Yangtze River had lower content of total organic carbon (TOC) and ferric ions, but higher bromide concentrations. Under controlled chlorination conditions, four trihalomethanes (THMs), nine haloacetic acids (HAAs), total organic halogen (TOX) and its halogen species fractions, including total organic chlorine (TOC1) and total organic bromide (TOBr), were determined. The results showed that co-existent ferric and bromide ions significantly promoted the formation of total THMs and HAAs for both raw water samples. Higher concentration of bromide ions significantly changed the speciation of the formed THMs and HAAs. There was an obvious shift to brominated species, which might result in a more adverse influence on the safety of drinking water. The results also indicated that high levels of bromide ions in raw water samples produced higher percentages of unknown TOBr.

  18. Clinical potential of aclidinium bromide in chronic obstructive pulmonary disease.

    PubMed

    Jones, Paul W

    2015-01-01

    Three long-acting muscarinic antagonists (LAMAs) are now available in Europe, providing clinicians and patients with a choice of interventions, which is important in COPD, which is clinically a heterogeneous disease. The first LAMA, tiotropium, has been widely used over the last decade as a once-daily maintenance therapy in stable COPD to improve patients' health-related quality of life and to reduce the risk of exacerbations. Administered via the HandiHaler(®) device, it is safe and well tolerated. Another new once-daily LAMA, glycopyrronium, has also been shown to improve health status and reduce exacerbations, and is well tolerated. The subject of this review is a third LAMA, aclidinium bromide, which was approved as a twice-daily maintenance bronchodilator treatment. In the pivotal Phase III clinical trials, patients receiving aclidinium achieved significantly greater improvements in lung function, reductions in breathlessness, and improvements in health status compared with placebo, for up to 24 weeks. In continuation studies, these improvements were sustained for up to 52 weeks. Pooled data showed exacerbation frequency was significantly reduced with aclidinium versus placebo. Preclinical and pharmacological studies demonstrating low systemic bioavailability and a low propensity to induce cardiac arrhythmias were translated into a favorable tolerability profile in the clinical trial program - the adverse event profile of aclidinium was similar to placebo, with a low incidence of anticholinergic and cardiac adverse events. While additional studies are needed to evaluate its full clinical potential, aclidinium is an important part of this recent expansion of LAMA therapeutic options, providing clinicians and patients with an effective and well-tolerated COPD treatment. PMID:25848244

  19. The killing of African trypanosomes by ethidium bromide.

    PubMed

    Roy Chowdhury, Arnab; Bakshi, Rahul; Wang, Jianyang; Yildirir, Gokben; Liu, Beiyu; Pappas-Brown, Valeria; Tolun, Gökhan; Griffith, Jack D; Shapiro, Theresa A; Jensen, Robert E; Englund, Paul T

    2010-12-16

    Introduced in the 1950s, ethidium bromide (EB) is still used as an anti-trypanosomal drug for African cattle although its mechanism of killing has been unclear and controversial. EB has long been known to cause loss of the mitochondrial genome, named kinetoplast DNA (kDNA), a giant network of interlocked minicircles and maxicircles. However, the existence of viable parasites lacking kDNA (dyskinetoplastic) led many to think that kDNA loss could not be the mechanism of killing. When recent studies indicated that kDNA is indeed essential in bloodstream trypanosomes and that dyskinetoplastic cells survive only if they have a compensating mutation in the nuclear genome, we investigated the effect of EB on kDNA and its replication. We here report some remarkable effects of EB. Using EM and other techniques, we found that binding of EB to network minicircles is low, probably because of their association with proteins that prevent helix unwinding. In contrast, covalently-closed minicircles that had been released from the network for replication bind EB extensively, causing them, after isolation, to become highly supertwisted and to develop regions of left-handed Z-DNA (without EB, these circles are fully relaxed). In vivo, EB causes helix distortion of free minicircles, preventing replication initiation and resulting in kDNA loss and cell death. Unexpectedly, EB also kills dyskinetoplastic trypanosomes, lacking kDNA, by inhibiting nuclear replication. Since the effect on kDNA occurs at a >10-fold lower EB concentration than that on nuclear DNA, we conclude that minicircle replication initiation is likely EB's most vulnerable target, but the effect on nuclear replication may also contribute to cell killing.

  20. Carbon isotope fractionation of methyl bromide during agricultural soil fumigations

    USGS Publications Warehouse

    Bill, M.; Miller, L.G.; Goldstein, Allen H.

    2002-01-01

    The isotopic composition of methyl bromide (CH3Br) has been suggested to be a potentially useful tracer for constraining the global CH3Br budget. In order to determine the carbon isotopic composition of CH3Br emitted from the most significant anthropogenic application (pre-plant fumigation) we directly measured the ??13C of CH3Br released during commercial fumigation. We also measured the isotopic fractionation associated with degradation in agricultural soil under typical field fumigation conditions. The isotopic composition of CH3Br collected in soil several hours after injection of the fumigant was -44.5??? and this value increased to -20.7??? over the following three days. The mean kinetic isotope effect (KIE) associated with degradation of CH3Br in agricultural soil (12???) was smaller than the reported value for methylotrophic bacterial strain IMB-1, isolated from previously fumigated agricultural soil, but was similar to methylotrophic bacterial strain CC495, isolated from a pristine forest litter zone. Using this fractionation associated with the degradation of CH3Br in agricultural soil and the mean ??13C of the industrially manufactured CH3Br (-54.4???), we calculate that the agricultural soil fumigation source has a carbon isotope signature that ranges from -52.8??? to -42.0???. Roughly 65% of industrially manufactured CH3Br is used for field fumigations. The remaining 35% is used for structural and post-harvest fumigations with a minor amount used during industrial chemical manufacturing. Assuming that the structural and post-harvest fumigation sources of CH3Br are emitted without substantial fractionation, we calculate that the ??13C of anthropogenically emitted CH3Br ranges from -53.2??? to -47.5???.

  1. Bacterial oxidation of methyl bromide in fumigated agricultural soils

    USGS Publications Warehouse

    Miller, L.G.; Connell, T.L.; Guidetti, J.R.; Oremland, R.S.

    1997-01-01

    The oxidation of [14C]methyl bromide ([14C]MeBr) to 14CO2 was measured in field experiments with soils collected from two strawberry plots fumigated with mixtures of MeBr and chloropicrin (CCI3NO2). Although these fumigants are considered potent biocides, we found that the highest rates of MeBr oxidation occurred 1 to 2 days after injection when the fields were tarped, rather than before or several days after injection. No oxidation of MeBr occurred in heat-killed soils, indicating that microbes were the causative agents of the oxidation. Degradation of MeBr by chemical and/or biological processes accounted for 20 to 50% of the loss of MeBr during fumigation, with evasion to the atmosphere inferred to comprise the remainder. In laboratory incubations, complete removal of [14C]MeBr occurred within a few days, with 47 to 67% of the added MeBr oxidized to 14CO2 and the remainder of counts associated with the solid phase. Chloropicrin inhibited the oxidation of MeBr, implying that use of this substance constrains the extent of microbial degradation of MeBr during fumigation. Oxidation was by direct bacterial attack of MeBr and not of methanol, a product of the chemical hydrolysis of MeBr. Neither nitrifying nor methane-oxidizing bacteria were sufficiently active in these soils to account for the observed oxidation of MeBr, nor could the microbial degradation of MeBr be linked to cooxidation with exogenously supplied electron donors. However, repeated addition of MeBr to live soils resulted in higher rates of its removal, suggesting that soil bacteria used MeBr as an electron donor for growth. To support this interpretation, we isolated a gram-negative, aerobic bacterium from these soils which grew with MeBr as a sole source of carbon and energy.

  2. Clinical potential of aclidinium bromide in chronic obstructive pulmonary disease

    PubMed Central

    Jones, Paul W

    2015-01-01

    Three long-acting muscarinic antagonists (LAMAs) are now available in Europe, providing clinicians and patients with a choice of interventions, which is important in COPD, which is clinically a heterogeneous disease. The first LAMA, tiotropium, has been widely used over the last decade as a once-daily maintenance therapy in stable COPD to improve patients’ health-related quality of life and to reduce the risk of exacerbations. Administered via the HandiHaler® device, it is safe and well tolerated. Another new once-daily LAMA, glycopyrronium, has also been shown to improve health status and reduce exacerbations, and is well tolerated. The subject of this review is a third LAMA, aclidinium bromide, which was approved as a twice-daily maintenance bronchodilator treatment. In the pivotal Phase III clinical trials, patients receiving aclidinium achieved significantly greater improvements in lung function, reductions in breathlessness, and improvements in health status compared with placebo, for up to 24 weeks. In continuation studies, these improvements were sustained for up to 52 weeks. Pooled data showed exacerbation frequency was significantly reduced with aclidinium versus placebo. Preclinical and pharmacological studies demonstrating low systemic bioavailability and a low propensity to induce cardiac arrhythmias were translated into a favorable tolerability profile in the clinical trial program – the adverse event profile of aclidinium was similar to placebo, with a low incidence of anticholinergic and cardiac adverse events. While additional studies are needed to evaluate its full clinical potential, aclidinium is an important part of this recent expansion of LAMA therapeutic options, providing clinicians and patients with an effective and well-tolerated COPD treatment. PMID:25848244

  3. Thermodynamic model for surfactant adsorption: Topical report. [Decyltrimethylammonium bromide

    SciTech Connect

    Woodbury, G.W. Jr.; Noll, L.A.

    1987-01-01

    A simple, semi-empirical thermodynamic model was constructed for the adsorption of solutions of surfactants onto solid surfaces. Essentially a modified finite-layer BET theory, the model is complete in that it predicts all surface thermodynamic properties. The properties of bulk solutions are considered in an exact way, and the availability of bulk thermodynamic properties is assumed. The theory has been applied satisfactorily to both the adsorption isotherm and the heat of adsorption curve for the adsorption of decyltrimethylammonium bromide (DTAB) on silica gel. In this system, the observed adsorption which occurs above the critical micelle concentration (CMC) depends on the detailed behavior of the bulk thermodynamic properties; since the measured surface properties are sensitive to bulk properties, the latter must be accounted for accurately. DTAB is the only reported surfactant system, for which both the isotherm and the heat have been measured and for which the bulk solution properties are known. A critical test of the theory awaits more data of this type; however, the theory has been tested against isotherms measured by Scamehorn, et al., and has been found to fit within experimental error below the CMC. There are many areas in which the adsorption of surfactants is of practical importance such as minerals processing, lubrication, and enhanced oil recovery. The theory should prove useful to all of these areas. In the scope of enhanced oil recovery, this theory is intended to be developed into an adsorption module for a reservoir simulator for surfactant-mineral systems whose behavior is too complex to be modeled by Henry's law or even a Langmuir isotherm. 15 refs., 6 figs., 2 tabs.

  4. Silica nanoparticles separation from water: aggregation by cetyltrimethylammonium bromide (CTAB).

    PubMed

    Liu, Y; Tourbin, M; Lachaize, S; Guiraud, P

    2013-07-01

    Nanoparticles will inevitably be found in industrial and domestic wastes in the near future and as a consequence soon in water resources. Due to their ultra-small size, nanoparticles may not only have new hazards for environment and human health, but also cause low separation efficiency by classical water treatments processes. Thus, it would be an important challenge to develop a specific treatment with suitable additives for recovery of nanoparticles from waters. For this propose, this paper presents aggregation of silica nanoparticles (Klebosol 30R50 (75nm) and 30R25 (30nm)) by cationic surfactant cetyltrimethylammonium bromide (CTAB). Different mechanisms such as charge neutralization, "depletion flocculation" or "volume-restriction", and "hydrophobic effect" between hydrocarbon tails of CTAB have been proposed to explicate aggregation results. One important finding is that for different volume concentrations between 0.05% and 0.51% of 30R50 suspensions, the same critical coagulation concentration was observed at CTAB=0.1mM, suggesting the optimized quantity of CTAB during the separation process for nanoparticles of about 75nm. Furthermore, very small quantities of CTAB (0.01mM) can make 30R25 nanosilica aggregated due to the "hydrophobic effect". It is then possible to minimize the sludge and allow the separation process as "greener" as possible by studying this case. It has also shown that aggregation mechanisms can be different for very small particles so that a special attention has to be paid to the treatment of nanoparticles contained in water and wastewaters.

  5. The fate of alternative soil fumigants to methyl bromide

    NASA Astrophysics Data System (ADS)

    Qin, R.; Gao, S.

    2011-12-01

    Soil fumigation is an important agricultural practice for the control of soil-borne pests. Since the phase-out of methyl bromide, due to its role in the depletion of stratospheric ozone, several alternatives such as 1,3-dichloropropene (1,3-D), chloropicrin (CP), and dimethyl disulfide (DMDS) are being increasingly used. The major processes and factors affecting the fate of these chemicals are evaluated. The high volatility of fumigants leads to high emission loss when no proper containment is used. Recent tarping technology using low permeability films can significantly reduce emissions. Fumigant degradation rate becomes critical to the determination of fumigation rate that affects efficacy and residence time in soil. A series of laboratory incubation experiments were carried out to determine degradation rate of 1,3-D isomers, CP and DMDS in five different soils collected from California and Florida. Fumigant degradation rates depend highly on the amounts of fumigants in soil, chemical characteristics, and soil conditions. Fumigant degradation rate were found to increase for all fumigants as the fumigant amounts in soil decreased. The changes were smaller for 1,3-D isomers compared to CP and DMDS. In soils with the lowest application rate, the degradation rate of fumigants is in the order of CP > DMDS > cis-1,3-D > trans-1,3-D. Soil and environmental factors also affect fumigant degradation rate. These findings suggest that a proper application rate should be determined for specific fumigants in a soil when using low permeability tarp in order to achieve sufficient fumigation efficacy during a certain period of time while minimizing potential surge of emissions after tarp removal and/or long residence time in soil that may cause phytotoxicity or leaching.

  6. Predicting bromide incorporation in a chlorinated indoor swimming pool.

    PubMed

    Chowdhury, Shakhawat; Mazumder, Abu Jafar; Husain, Tahir

    2016-06-01

    The water in and air above swimming pools often contain high levels of disinfection byproducts (DBPs) due to chemical reactions between chlorine- or bromine-based disinfectants and organic/inorganic matter in the source water and released from swimmers. Exposure to these DBPs, though inevitable, can pose health threats to humans. In this study, DBPs in tap water (S1), and water from a chlorinated indoor swimming pool before (S2) and after swimming (S3) were measured. The brominated species constituted the majority of DBPs formed in S1, S2, and S3. Trihalomethanes (THMs) in S3 was 6.9 (range 2.9-11.1) and 1.4 (range 0.52-2.9) times those in S1 and S2, respectively; and the haloacetic acids (HAAs) in S3 was 4.2 (range 2.5-7.5) and 1.2 (range 0.6-2.6) times those in S1 and S2, respectively. The mean THMs in air above the swimming pool before (S2-A) and after swimming (S3-A) were 72.2 and 93.0 μg/m(3), respectively, and their ranges were 36.3-105.8 and 44.1-133.6 μg/m(3), respectively. The average percentages of bromide incorporation (BI) into THMs in S1, S2, and S3 were 3.0, 9.3, and 10.6 %, respectively; and the BI into HAAs in S1, S2, and S3 were 6.6, 12.0, and 12.2 %, respectively. Several models were trained for predicting the BI into THMs and HAAs. The results indicate that additional information is required to develop predictive models for BI in swimming pools.

  7. The Killing of African Trypanosomes by Ethidium Bromide

    PubMed Central

    Roy Chowdhury, Arnab; Bakshi, Rahul; Wang, Jianyang; Yildirir, Gokben; Liu, Beiyu; Pappas-Brown, Valeria; Tolun, Gökhan; Griffith, Jack D.; Shapiro, Theresa A.; Jensen, Robert E.; Englund, Paul T.

    2010-01-01

    Introduced in the 1950s, ethidium bromide (EB) is still used as an anti-trypanosomal drug for African cattle although its mechanism of killing has been unclear and controversial. EB has long been known to cause loss of the mitochondrial genome, named kinetoplast DNA (kDNA), a giant network of interlocked minicircles and maxicircles. However, the existence of viable parasites lacking kDNA (dyskinetoplastic) led many to think that kDNA loss could not be the mechanism of killing. When recent studies indicated that kDNA is indeed essential in bloodstream trypanosomes and that dyskinetoplastic cells survive only if they have a compensating mutation in the nuclear genome, we investigated the effect of EB on kDNA and its replication. We here report some remarkable effects of EB. Using EM and other techniques, we found that binding of EB to network minicircles is low, probably because of their association with proteins that prevent helix unwinding. In contrast, covalently-closed minicircles that had been released from the network for replication bind EB extensively, causing them, after isolation, to become highly supertwisted and to develop regions of left-handed Z-DNA (without EB, these circles are fully relaxed). In vivo, EB causes helix distortion of free minicircles, preventing replication initiation and resulting in kDNA loss and cell death. Unexpectedly, EB also kills dyskinetoplastic trypanosomes, lacking kDNA, by inhibiting nuclear replication. Since the effect on kDNA occurs at a >10-fold lower EB concentration than that on nuclear DNA, we conclude that minicircle replication initiation is likely EB's most vulnerable target, but the effect on nuclear replication may also contribute to cell killing. PMID:21187912

  8. Chlorine-36, bromide, and the origin of spring water

    USGS Publications Warehouse

    Davis, S.N.; Cecil, L.D.; Zreda, M.; Moysey, S.

    2001-01-01

    Natural ratios of chlorine-36 (36Cl) to stable chlorine (i.e., 36Cl/Cl ?? 10-15) vary in shallow groundwater of the United States from about 50 in coastal areas to about 1400 in the northern Rocky Mountains. Ratios lower than these indicate the presence of chloride (Cl-) that has been isolated from the atmosphere for hundreds of thousands of years, if not longer. Higher ratios, which can exceed 5000, usually originate from fallout from testing thermonuclear devices in the western Pacific in the 1950s. Natural mass ratios of chloride to bromide (Cl-/Br-) in precipitation vary in the United States from about 250 in coastal areas to about 50 in the north-central states. Lower ratios may suggest contamination from human sources. Higher ratios, which may exceed 2000, commonly reflect the dissolution of halite. Seawater has a Cl-/Br- ratio of 290. Both 36Cl and Cl-/Br- ratios have been measured in 21 samples of spring water collected from springs in 10 different states. Brackish water from Saratoga Springs area in New York has low values for both 36Cl and Cl-/Br- ratios. This indicates that a large component of the water has a very deep origin. Brackish water from Alexander Springs in Florida has a low 36Cl ratio but a high Cl-/Br- ratio similar to seawater. This suggests the addition of ancient seawater that may be trapped in the aquifer. Big Spring in Iowa discharges water with a very high Cl-/Br- ratio but a moderate 36Cl ratio. The high ratio of Cl-/Br- may be produced by dissolution of road salt or agricultural chemicals. Of the 21 springs sampled, only 10 appeared to have potable water not significantly affected by human activity. Chlorine-36 from testing of nuclear devices is still being flushed out of four of the spring systems that were sampled. Thus, more than 45 years have passed since 36Cl was introduced into the aquifers feeding the springs and the systems, as yet, have not been purged. Published by Elsevier Science B.V.

  9. The ocean in near equilibrium with atmospheric methyl bromide

    NASA Astrophysics Data System (ADS)

    Hu, Lei; Yvon-Lewis, Shari; Liu, Yina; Bianchi, Thomas S.

    2012-09-01

    Saturation-anomaly measurements of methyl bromide (CH3Br) were made in the eastern Pacific (3/30-4/27, 2010) and the eastern Atlantic (10/25-11/26, 2010) to assess the oceanic saturation state as the phaseout of fumigation - non-Quarantine and Pre-Shipment (non-QPS) uses of CH3Br nears completion and atmospheric concentrations continue to decline. These cruises occurred 16 years after the Bromine Latitudinal Air-Sea Transect (BLAST) cruises, which were conducted in the same regions and first established a global oceanic net sink of -12.6 Gg yr-1 for atmospheric CH3Br in 1994. Results from this study suggest saturation anomalies of CH3Br in the surface ocean have become less negative than those observed 16 years ago as the atmospheric burden has declined over the past decade. The global net sea-to-air flux was estimated at 0 to 3 Gg yr-1 in 2010, suggesting that the ocean may become a net small source to atmospheric CH3Br. There are no significant differences between this study and previous studies for measured biological loss rate constants and calculated annual production rates, suggesting that annual production rates and biological degradation rate constants for CH3Br in the surface ocean have likely remained relatively constant over the past 16 years. When including the biological loss rate constants from this study and all previous studies, the mean global biological loss rate constant is constrained to 0.05 ± 0.01 d-1 (at a 95% confidence level). Combining chemical and eddy degradation rate constants, and using an updated gas transfer velocity, we estimate the CH3Br partial atmospheric lifetime with respect to oceanic loss to be 3.1 (2.3 to 5.0) years. Although the new partial atmospheric lifetime is about 1.3 years longer than the best prior estimate, it does not change the overall atmospheric lifetime of CH3Br, 0.8 (0.7-0.9) years.

  10. Residential Proximity to Methyl Bromide Use and Birth Outcomes in an Agricultural Population in California

    PubMed Central

    Gemmill, Alison; Gunier, Robert B.; Bradman, Asa; Eskenazi, Brenda

    2013-01-01

    Background: Methyl bromide, a fungicide often used in strawberry cultivation, is of concern for residents who live near agricultural applications because of its toxicity and potential for drift. Little is known about the effects of methyl bromide exposure during pregnancy. Objective: We investigated the relationship between residential proximity to methyl bromide use and birth outcomes. Methods: Participants were from the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) study (n = 442), a longitudinal cohort study examining the health effects of environmental exposures on pregnant women and their children in an agricultural community in northern California. Using data from the California Pesticide Use Reporting system, we employed a geographic information system to estimate the amount of methyl bromide applied within 5 km of a woman’s residence during pregnancy. Multiple linear regression models were used to estimate associations between trimester-specific proximity to use and birth weight, length, head circumference, and gestational age. Results: High methyl bromide use (vs. no use) within 5 km of the home during the second trimester was negatively associated with birth weight (β = –113.1 g; CI: –218.1, –8.1), birth length (β = –0.85 cm; CI: –1.44, –0.27), and head circumference (β = –0.33 cm; CI: –0.67, 0.01). These outcomes were also associated with moderate methyl bromide use during the second trimester. Negative associations with fetal growth parameters were stronger when larger (5 km and 8 km) versus smaller (1 km and 3 km) buffer zones were used to estimate exposure. Conclusions: Residential proximity to methyl bromide use during the second trimester was associated with markers of restricted fetal growth in our study. PMID:23603811

  11. Bromine and bromide content in soils: Analytical approach from total reflection X-ray fluorescence spectrometry.

    PubMed

    Gallardo, Helena; Queralt, Ignasi; Tapias, Josefina; Candela, Lucila; Margui, Eva

    2016-08-01

    Monitoring total bromine and bromide concentrations in soils is significant in many environmental studies. Thus fast analytical methodologies that entail simple sample preparation and low-cost analyses are desired. In the present work, the possibilities and drawbacks of low-power total reflection X-ray fluorescence spectrometry (TXRF) for the determination of total bromine and bromide contents in soils were evaluated. The direct analysis of a solid suspension using 20 mg of fine ground soil (<63 μm) gave a 3.7 mg kg(-1) limit of detection for bromine which, in most cases, was suitable for monitoring total bromine content in soils (Br content range in soils = 5-40 mg kg(-1)). Information about bromide determination in soils is also possible by analyzing the Br content in water soil extracts. In this case, the TXRF analysis can be directly performed by depositing 10 μL of the internal standardized soil extract sample on a quartz glass reflector in a measuring time of 1500 s. The bromide limit of detection by this approach was 10 μg L(-1). Good agreement was obtained between the TXRF results for the total bromine and bromide determinations in soils and those obtained by other popular analytical techniques, e.g. energy dispersive X-ray fluorescence spectrometry (total bromine) and ionic chromatography (bromide). As a study case, the TXRF method was applied to study bromine accumulation in two agricultural soils fumigated with a methyl bromide pesticide and irrigated with regenerated waste water. PMID:27179429

  12. Bromine and bromide content in soils: Analytical approach from total reflection X-ray fluorescence spectrometry.

    PubMed

    Gallardo, Helena; Queralt, Ignasi; Tapias, Josefina; Candela, Lucila; Margui, Eva

    2016-08-01

    Monitoring total bromine and bromide concentrations in soils is significant in many environmental studies. Thus fast analytical methodologies that entail simple sample preparation and low-cost analyses are desired. In the present work, the possibilities and drawbacks of low-power total reflection X-ray fluorescence spectrometry (TXRF) for the determination of total bromine and bromide contents in soils were evaluated. The direct analysis of a solid suspension using 20 mg of fine ground soil (<63 μm) gave a 3.7 mg kg(-1) limit of detection for bromine which, in most cases, was suitable for monitoring total bromine content in soils (Br content range in soils = 5-40 mg kg(-1)). Information about bromide determination in soils is also possible by analyzing the Br content in water soil extracts. In this case, the TXRF analysis can be directly performed by depositing 10 μL of the internal standardized soil extract sample on a quartz glass reflector in a measuring time of 1500 s. The bromide limit of detection by this approach was 10 μg L(-1). Good agreement was obtained between the TXRF results for the total bromine and bromide determinations in soils and those obtained by other popular analytical techniques, e.g. energy dispersive X-ray fluorescence spectrometry (total bromine) and ionic chromatography (bromide). As a study case, the TXRF method was applied to study bromine accumulation in two agricultural soils fumigated with a methyl bromide pesticide and irrigated with regenerated waste water.

  13. Determination of methyl bromide in air samples by headspace gas chromatography

    SciTech Connect

    Woodrow, J.E.; McChesney, M.M.; Seiber, J.N.

    1988-03-01

    Methyl bromide is extensively used in agriculture (4 x 10/sup 6/ kg for 1985 in California alone as a fumigant to control nematodes, weeds, and fungi in soil and insect pests in harvested grains and nuts. Given its low boiling point (3.8/sup 0/C) and high vapor pressure (approx. 1400 Torr at 20/sup 0/C), methyl bromide will readily diffuse if not rigorously contained. Methods for determining methyl bromide and other halocarbons in air vary widely. A common practice is to trap the material from air on an adsorbent, such as polymeric resins, followed by thermal desorption either directly into the analytical instrumentation or after intermediary cryofocusing. While in some cases analytical detection limits were reasonable (parts per million range), many of the published methods were labor intensive and required special handling techniques that precluded high sample throughput. They describe here a method for the sampling and analysis of airborne methyl bromide that was designed to handle large numbers of samples through automating some critical steps of the analysis. The result was a method that allowed around-the-clock operation with a minimum of operator attention. Furthermore, the method was not specific to methyl bromide and could be used to determine other halocarbons in air.

  14. Mepenzolate bromide promotes diabetic wound healing by modulating inflammation and oxidative stress

    PubMed Central

    Zheng, Yongjun; Wang, Xingtong; Ji, Shizhao; Tian, Song; Wu, Haibin; Luo, Pengfei; Fang, He; Wang, Li; Wu, Guosheng; Xiao, Shichu; Xia, Zhaofan

    2016-01-01

    Diabetic wounds are characterized by persistent inflammation and the excessive production of reactive oxygen species, thus resulting in impaired wound healing. Mepenzolate bromide, which was originally used to treat gastrointestinal disorders in clinical settings, has recently been shown to display beneficial effects in chronic obstructive pulmonary disease and pulmonary fibrosis of a mouse model by inhibiting inflammatory responses and reducing oxidative stress. However,the role of mepenzolate bromide in diabetic wound healing is still unclear. In this study, full-thickness excisional skin wounds were created on the backs of db/db mice, and mepenzolate bromide was topically applied to the wound bed. We found that mepenzolate bromide significantly promoted diabetic wound healing by measuring wound closure rate and histomorphometric analyses. Further studies showed that inflammation was inhibited by assessing the number of macrophages and levels of pro-inflammatory cytokines and pro-healing cytokines in the wounds. Furthermore, oxidative stress was reduced by monitoring the levels of MDA and H2O2 and the activities of glutathione peroxidase and catalase in the wounds. These results demonstrated the potential application of mepenzolate bromide for treating diabetic ulcers and other chronic wounds in clinics. PMID:27398156

  15. [Bowel obstruction-induced cholinergic crisis with progressive respiratory failure following distigmine bromide treatment].

    PubMed

    Kobayashi, Kazuki; Sekiguchi, Hiroshi; Sato, Nobuhiro; Hirose, Yasuo

    2016-03-01

    A 54-year-old female experienced rapid respiratory failure while being transported in an ambulance to our emergency department for evaluation and management of constipation and abdominal pain. The patient was on treatment with distigmine bromide for postoperative urination disorder and magnesium oxide for constipation. Increased salivary secretions, diminished respiratory excursion, type 2 respiratory failure (PaCO2 : 65 mmHg), low serum cholinesterase, and hypermagnesemia were detected. Imaging studies revealed that the patient had bilateral aspiration pneumonia, fecal impaction in the rectum, and a distended colon causing ileus. The patient was mechanically ventilated and was weaned off the ventilator on day 3. Therapeutic drug monitoring after discharge revealed that the serum level of distigmine bromide on admission was markedly elevated (377.8 ng/mL vs. the normal therapeutic level of 5-10 ng/mL). Distigmine bromide induced a cholinergic crisis with a resultant increase in airway secretions and respiratory failure. In this particular case, orally administered distigmine bromide was excessively absorbed because of prolonged intestinal transit time secondary to fecal impaction and sluggish bowel movement; this caused a cholinergic crisis and hypermagnesemia contributing to respiratory failure. Clinicians should be aware that bowel obstruction in a patient treated with distigmine bromide can increase the risk of a cholinergic crisis. PMID:27255021

  16. Mepenzolate bromide promotes diabetic wound healing by modulating inflammation and oxidative stress.

    PubMed

    Zheng, Yongjun; Wang, Xingtong; Ji, Shizhao; Tian, Song; Wu, Haibin; Luo, Pengfei; Fang, He; Wang, Li; Wu, Guosheng; Xiao, Shichu; Xia, Zhaofan

    2016-01-01

    Diabetic wounds are characterized by persistent inflammation and the excessive production of reactive oxygen species, thus resulting in impaired wound healing. Mepenzolate bromide, which was originally used to treat gastrointestinal disorders in clinical settings, has recently been shown to display beneficial effects in chronic obstructive pulmonary disease and pulmonary fibrosis of a mouse model by inhibiting inflammatory responses and reducing oxidative stress. However,the role of mepenzolate bromide in diabetic wound healing is still unclear. In this study, full-thickness excisional skin wounds were created on the backs of db/db mice, and mepenzolate bromide was topically applied to the wound bed. We found that mepenzolate bromide significantly promoted diabetic wound healing by measuring wound closure rate and histomorphometric analyses. Further studies showed that inflammation was inhibited by assessing the number of macrophages and levels of pro-inflammatory cytokines and pro-healing cytokines in the wounds. Furthermore, oxidative stress was reduced by monitoring the levels of MDA and H2O2 and the activities of glutathione peroxidase and catalase in the wounds. These results demonstrated the potential application of mepenzolate bromide for treating diabetic ulcers and other chronic wounds in clinics. PMID:27398156

  17. Methyl bromide: ocean sources, ocean sinks, and climate sensitivity.

    PubMed

    Anbar, A D; Yung, Y L; Chavez, F P

    1996-03-01

    The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

  18. Methyl bromide: ocean sources, ocean sinks, and climate sensitivity.

    PubMed

    Anbar, A D; Yung, Y L; Chavez, F P

    1996-03-01

    The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

  19. Methyl bromide: ocean sources, ocean sinks, and climate sensitivity

    NASA Technical Reports Server (NTRS)

    Anbar, A. D.; Yung, Y. L.; Chavez, F. P.

    1996-01-01

    The oceans play an important role in the geochemical cycle of methyl bromide (CH3Br), the major carrier of O3-destroying bromine to the stratosphere. The quantity of CH3Br produced annually in seawater is comparable to the amount entering the atmosphere each year from natural and anthropogenic sources. The production mechanism is unknown but may be biological. Most of this CH3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmosphere is poorly constrained; measurements in seawater and the atmosphere have been used to justify both a large oceanic CH3Br flux to the atmosphere and a small net ocean sink. Since the consumption reactions are extremely temperature-sensitive, small temperature variations have large effects on the CH3Br concentration in seawater, and therefore on the exchange between the atmosphere and the ocean. The net CH3Br flux is also sensitive to variations in the rate of CH3Br production. We have quantified these effects using a simple steady state mass balance model. When CH3Br production rates are linearly scaled with seawater chlorophyll content, this model reproduces the latitudinal variations in marine CH3Br concentrations observed in the east Pacific Ocean by Singh et al. [1983] and by Lobert et al. [1995]. The apparent correlation of CH3Br production with primary production explains the discrepancies between the two observational studies, strengthening recent suggestions that the open ocean is a small net sink for atmospheric CH3Br, rather than a large net source. The Southern Ocean is implicated as a possible large net source of CH3Br to the atmosphere. Since our model indicates that both the direction and magnitude of CH3Br exchange between the atmosphere and ocean are extremely sensitive to temperature and marine productivity, and since the rate of CH3Br production in the oceans is comparable to the rate at which this compound is introduced to the atmosphere, even small

  20. Current and Potential Future Bromide Loads from Coal-Fired Power Plants in the Allegheny River Basin and Their Effects on Downstream Concentrations.

    PubMed

    Good, Kelly D; VanBriesen, Jeanne M

    2016-09-01

    The presence of bromide in rivers does not affect ecosystems or present a human health risk; however, elevated concentrations of bromide in drinking water sources can lead to difficulty meeting drinking water disinfection byproduct (DBP) regulations. Recent attention has focused on oil and gas wastewater and coal-fired power plant wet flue gas desulfurization (FGD) wastewater bromide discharges. Bromide can be added to coal to enhance mercury removal, and increased use of bromide at some power plants is expected. Evaluation of potential increases in bromide concentrations from bromide addition for mercury control is lacking. The present work utilizes bromide monitoring data in the Allegheny River and a mass-balance approach to elucidate bromide contributions from anthropogenic and natural sources under current and future scenarios. For the Allegheny River, the current bromide is associated approximately 49% with oil- and gas-produced water discharges and 33% with coal-fired power plants operating wet FGD, with 18% derived from natural sources during mean flow conditions in August. Median wet FGD bromide loads could increase 3-fold from 610 to 1900 kg/day if all plants implement bromide addition for mercury control. Median bromide concentrations in the lower Allegheny River in August would rise to 410, 200, and 180 μg/L under low-, mean-, and high-flow conditions, respectively, for the bromide-addition scenario. PMID:27538590

  1. Current and Potential Future Bromide Loads from Coal-Fired Power Plants in the Allegheny River Basin and Their Effects on Downstream Concentrations.

    PubMed

    Good, Kelly D; VanBriesen, Jeanne M

    2016-09-01

    The presence of bromide in rivers does not affect ecosystems or present a human health risk; however, elevated concentrations of bromide in drinking water sources can lead to difficulty meeting drinking water disinfection byproduct (DBP) regulations. Recent attention has focused on oil and gas wastewater and coal-fired power plant wet flue gas desulfurization (FGD) wastewater bromide discharges. Bromide can be added to coal to enhance mercury removal, and increased use of bromide at some power plants is expected. Evaluation of potential increases in bromide concentrations from bromide addition for mercury control is lacking. The present work utilizes bromide monitoring data in the Allegheny River and a mass-balance approach to elucidate bromide contributions from anthropogenic and natural sources under current and future scenarios. For the Allegheny River, the current bromide is associated approximately 49% with oil- and gas-produced water discharges and 33% with coal-fired power plants operating wet FGD, with 18% derived from natural sources during mean flow conditions in August. Median wet FGD bromide loads could increase 3-fold from 610 to 1900 kg/day if all plants implement bromide addition for mercury control. Median bromide concentrations in the lower Allegheny River in August would rise to 410, 200, and 180 μg/L under low-, mean-, and high-flow conditions, respectively, for the bromide-addition scenario.

  2. Inhibitory effect of pinaverium bromide on gastrointestinal contractile activity in conscious dogs.

    PubMed

    Itoh, Z; Takahashi, I

    1981-01-01

    The inhibitory effect of 4-(6-bromoveratryl)-4-(2-[2-(6,6-dimethyl-2-norpinyl)-ethoxy]-ethyl)-morpholinium hydroxide (pinaverium bromide), a quaternary ammonium derivative, on the contractile activity of the gastrointestinal tract from the stomach to the colon was investigated in six conscious dogs. Gastrointestinal motor activity was monitored by means of chronically implanted force transducers. Pinaverium bromide was continuously administered i.v. for 30 min in doses of 10 and 20 mg/kg/h during both the digestive and interdigestive states. It was found that pinaverium bromide strongly inhibited gastrointestinal contractile activity during both the digestive and interdigestive states; contractions in the stomach were most strongly inhibited; however, those in the small and large bowels were also significantly inhibited. No significant side effects in the circulatory and respiratory systems and the gastrointestinal tract such as nausea, vomiting or diarrhea were observed during and after the infusion of this agent. PMID:7197953

  3. Efficient Planar Heterojunction Perovskite Solar Cells Based on Formamidinium Lead Bromide.

    PubMed

    Hanusch, Fabian C; Wiesenmayer, Erwin; Mankel, Eric; Binek, Andreas; Angloher, Philipp; Fraunhofer, Christina; Giesbrecht, Nadja; Feckl, Johann M; Jaegermann, Wolfram; Johrendt, Dirk; Bein, Thomas; Docampo, Pablo

    2014-08-21

    The development of medium-bandgap solar cell absorber materials is of interest for the design of devices such as tandem solar cells and building-integrated photovoltaics. The recently developed perovskite solar cells can be suitable candidates for these applications. At present, wide bandgap alkylammonium lead bromide perovskite absorbers require a high-temperature sintered mesoporous TiO2 photoanode in order to function efficiently, which makes them unsuitable for some of the above applications. Here, we present for the first time highly efficient wide bandgap planar heterojunction solar cells based on the structurally related formamidinium lead bromide. We show that this material exhibits much longer diffusion lengths of the photoexcited species than its methylammonium counterpart. This results in planar heterojunction solar cells exhibiting power conversion efficiencies approaching 7%. Hence, formamidinium lead bromide is a strong candidate as a wide bandgap absorber in perovskite solar cells.

  4. Dispersion characteristics and sinks for methyl bromide vapors downwind of treated agricultural fields

    SciTech Connect

    Seiber, J.N.; Woodrow, J.E.; Dowling, K.

    1995-12-31

    A study of methyl bromide volatilization and fate from a treated agricultural field was conducted in Monterey County, California, in 1994. Air concentrations were measured above and downwind from the field with the objective of comparing vertical and horizontal flux terms. Another objective was to compare observed downwind concentrations with those predicted by the Industrial Source Complex model, to begin the process of identifying potential sinks which might scavenge methyl bromide from the atmosphere. The final objective was to determine the limit of detection of our analytical method for airborne methyl bromide using field samples representing a wide range of concentrations. A description of the methods and results of the study will be presented, along with a discussion of data quality and interpretation.

  5. 2-O-substituted cyclodextrins as reversal agents for the neuromuscular blocker rocuronium bromide.

    PubMed

    Tarver, Gary J; Grove, Simon J A; Buchanan, Kirsteen; Bom, Anton; Cooke, Andrew; Rutherford, Samantha J; Zhang, Ming Qiang

    2002-06-01

    A series of secondary face modified cyclodextrins (CDs) were synthesised with the aim of constructing host molecules capable of forming host-guest complexes with neuromuscular blockers, especially with rocuronium bromide. Perfacial 2-O-substitution of gamma-CD with 4-carboxybenzyl resulted in a CD host molecule 1 that forms a 1:1 binary complex with rocuronium bromide (K(a) 6.2 x 10(5) M(-1)). The biological activities of this compound and other derivatives as reversal agents of rocuronium bromide were examined in vitro (mouse hemi-diaphragm) and in vivo (anaesthetized guinea pigs). The host molecule 1 was found to exert potent reversal activity (ED(50) 0.21 micromol/kg, iv) against rocuronium-induced neuromuscular block, and thus proved the viability of using host molecules as antidotes of a biologically active compound.

  6. Synthesis and Characterization of the Antimicrobial 4-AMINO-DECYLPYRIDINIUM Bromide Cationic Surfactant

    NASA Astrophysics Data System (ADS)

    Madaan, Parag; Tyagi, V. K.

    4-Amino-decylpyridinium bromide (ADPBr), an antimicrobial surface active agent, was synthesized by quaternization of 4-aminopyridine (AP) with decyl bromide (DBr). The reaction was carried out at 1:1.2 molar ratio of reactants (4-aminopyridine and decyl bromide, respectively) at 200°C for 10 min. The maximum yield of the product was 74.6%. The structure of the synthesized product was characterized by using modern analytical techniques, such as FT-IR, 1H NMR, and 13C NMR. The antimicrobial activity of the salt was evaluated with minimum inhibition concentration method and showed good activity against gram-negative bacteria. The MIC of the salt was found to be 600 ppm for 2 × 104 CFU/mL of E. coli.

  7. Seeded Growth of Monodisperse Gold Nanorods Using Bromide-Free Surfactant Mixtures

    SciTech Connect

    Ye, XC; Gao, YZ; Chen, J; Reifsnyder, DC; Zheng, C; Murray, CB

    2013-05-01

    We demonstrate for the first time that monodisperse gold nanorods (NRs) with broadly tunable dimensions and longitudinal surface plasmon resonances can be synthesized using a bromide-free surfactant mixture composed of alkyltrimethylammonium chloride and sodium oleate. It is found that uniform gold NRs can be obtained even with an iodide concentration approaching 100 mu M in the growth solution. In contrast to conventional wisdom, our results provide conclusive evidence that neither bromide as the surfactant counterion nor a high concentration of bromide ions in the growth solution is essential for gold NR formation. Correlated electron microscopy study of three-dimensional structures of gold NRs reveals a previously unprecedented octagonal prismatic structure enclosed predominantly by high index {310} crystal planes. These findings should have profound implications for a comprehensive mechanistic understanding of seeded growth of anisotropic metal nanocrystals.

  8. Chloride/bromide ratios in leachate derived from farm-animal waste.

    PubMed

    Hudak, Paul F

    2003-01-01

    Ratios of conservative chemicals have been used to identify sources of groundwater contamination. While chloride/bromide ratios have been reported for several common sources of groundwater contamination, little work has been done on leachate derived from farm-animal waste. In this study, chloride/bromide ratios were measured in leachate derived from longhorn-cattle, quarterhorse, and pygme-goat waste at a farm in Abilene, Texas, USA. (Minimum, median, and maximum) chloride/bromide ratios of (66.5, 85.6, and 167), (119, 146, and 156), and (35.4, 57.8, and 165) were observed for cattle, horses, and goats, respectively. These ratios are below typical values for domestic wastewater and within the range commonly observed for oilfield brine. Results of this study have important implications for identifying sources of contaminated groundwater in settings with significant livestock and/or oil production.

  9. Salty glycerol versus salty water surface organization: bromide and iodide surface propensities.

    PubMed

    Huang, Zishuai; Hua, Wei; Verreault, Dominique; Allen, Heather C

    2013-07-25

    Salty NaBr and NaI glycerol solution interfaces are examined in the OH stretching region using broadband vibrational sum frequency generation (VSFG) spectroscopy. Raman and infrared (IR) spectroscopy are used to further understand the VSFG spectroscopic signature. The VSFG spectra of salty glycerol solutions reveal that bromide and iodide anions perturb the interfacial glycerol organization in a manner similar as that found in aqueous halide salt solutions, thus confirming the presence of bromide and iodide anions at the glycerol surface. Surface tension measurements are consistent with the surface propensity suggested by the VSFG data and also show that the surface excess increases with increasing salt concentration, similar to that of water. In addition, iodide is shown to have more surface prevalence than bromide, as has also been determined from aqueous solutions. These results suggest that glycerol behaves similarly to water with respect to surface activity and solvation of halide anions at its air/liquid interface. PMID:23663033

  10. Disposition of [14C]methyl bromide in Fischer-344 rats after oral or intraperitoneal administration.

    PubMed

    Medinsky, M A; Bond, J A; Dutcher, J S; Birnbaum, L S

    1984-09-14

    Methyl bromide is used as a disinfectant to fumigate soil. The intent of our study was to determine the disposition of methyl bromide following a single acute administration. Male Fischer-344 rats were given 250 mumol of [14C] methyl bromide/kg body wt by either oral or i.p. administration. Urine, feces and expired air were collected and at the end of 72 h the rats were sacrificed and tissues analyzed to determine 14C excretion and tissue distribution. After i.p. administration of methyl bromide, the dominant route of excretion was exhalation of 14CO2, with 46% of the dose exhaled as 14CO2. In contrast, urinary excretion of 14C was the major route of elimination (43% of the dose) when methyl bromide was given orally. Very little of the 14C appeared in the feces (less than 3% of the dose) regardless of route of administration. In rats with bile duct cannulations, 46% of an oral dose appeared in the bile over a 24-h period. Collection of bile significantly decreased the exhalation of 14CO2 and 14C excreted in urine compared to controls. At 72 h after oral or i.p. administration, 14-17% of the 14C remained in the rats, with liver and kidney being the major organs of retention. Results indicate that route of administration can affect the pathways for excretion. In addition, excretion of 14C in bile, coupled with the low levels of radioactivity found in the feces, indicates that reabsorption of biliary metabolites from the gut plays a significant role in the disposition of [14C] methyl bromide.

  11. Effect of chloramphenicol and ethidium bromide on the level of ornithine carbamoyltransferase in Neurospora crassa

    SciTech Connect

    Zerez, C.R.; Weiss, R.L.

    1986-05-01

    The specific activity of the nuclear-gene-encoded, mitochondrial arginine biosynthetic enzyme ornithine carbamoyltransferase in Neurospora crassa was elevated in mycelia treated with chloramphenicol or ethidium bromide. The increase in specific activity was caused by an increase in the number of mature enzyme molecules rather than by the activation of a preexisting enzyme. Chloramphenicol and ethidium bromide appeared to act indirectly via arginine-mediated derepression. However, derepression did not appear to result from a drug-mediated decrease in the arginine pool.

  12. Active Control of Interface Shape During the Crystal Growth of Lead Bromide

    NASA Technical Reports Server (NTRS)

    Duval, W. M. B.; Batur, C.; Singh, N. B.

    2003-01-01

    A thermal model for predicting and designing the furnace temperature profile was developed and used for the crystal growth of lead bromide. The model gives the ampoule temperature as a function of the furnace temperature, thermal conductivity, heat transfer coefficients, and ampoule dimensions as variable parameters. Crystal interface curvature was derived from the model and it was compared with the predicted curvature for a particular furnace temperature and growth parameters. Large crystals of lead bromide were grown and it was observed that interface shape was in agreement with the shape predicted by this model.

  13. Breakdown of ionic character of molecular alkali bromides in inner-valence photoionization

    SciTech Connect

    Karpenko, A. Iablonskyi, D.; Kettunen, J. A.; Cao, W.; Huttula, M.; Aksela, H.; Urpelainen, S.

    2014-05-28

    The inner-valence region of alkali bromide XBr (X=Li, Na, K, Rb) vapours has been studied experimentally by means of synchrotron radiation excited photoelectron spectroscopy. Experimental spectra were analyzed by comparing them with available theoretical results and previous experiments. Ionic character of alkali bromides is seen to change in the inner-valence region with increasing atomic number of the alkali atom. A mechanism involving mixing between Br 4s and Rb 4p orbitals has been suggested to account for the fine structure observed in inner-valence ionization region of RbBr.

  14. Disposition of [14C]methyl bromide in rats after inhalation.

    PubMed

    Bond, J A; Dutcher, J S; Medinsky, M A; Henderson, R F; Birnbaum, L S

    1985-04-01

    Methyl bromide is used as a disinfectant to fumigate soil and a wide range of stored food commodities in warehouses and mills. Human exposure occurs during the manufacture and use of the chemical. The purpose of this investigation was to determine the disposition and metabolism of [14C]methyl bromide in rats after inhalation. Male Fischer-344 rats were exposed nose only to a vapor concentration of 337 nmol [14C]methyl bromide/liter air (9.0 ppm, 25 degrees C, 620 torr) for 6 hr. Urine, feces, expired air, and tissues were collected for up to 65 hr after exposure. Elimination of 14C as 14CO2 was the major route of excretion with about 47% (3900 nmol/rat) of the total [14C]methyl bromide absorbed excreted by this route. CO2 excretion exhibited a biphasic elimination pattern with 85% of the 14CO2 being excreted with a half-time of 3.9 +/- 0.1 hr (means +/- SE) and 15% excreted with a half-time of 11.4 +/- 0.2 hr. Half-times for elimination of 14C in urine and feces were 9.6 +/- 0.1 and 16.1 +/- 0.1 hr, respectively. By 65 hr after exposure, about 75% of the initial radioactivity had been excreted with 25% remaining in the body. Radioactivity was widely distributed in tissues immediately following exposure with lung (250 nmol equivalents/g), adrenal (240 nmol equivalents/g), kidney (180 nmol equivalents/g), liver (130 nmol equivalents/g), and nasal turbinates (110 nmol equivalents/g) containing the highest concentrations of 14C. Radioactivity in livers immediately after exposure accounted for about 17% of the absorbed methyl bromide. Radioactivity in all other tissues examined accounted for about 10% of the absorbed methyl bromide. Elimination half-times of 14C from tissues were on the order of 1.5 to 8 hr. In all tissues examined, over 90% of the 14C in the tissues was methyl bromide metabolites. The data from this study indicate that after inhalation methyl bromide is rapidly metabolized in tissues and readily excreted.

  15. Bromide, Chloride, and Sulfate Concentrations, and Specific Conductance, Lake Texoma, Texas and Oklahoma, 2007-08

    USGS Publications Warehouse

    Baldys, Stanley

    2009-01-01

    The U.S. Geological Survey, in cooperation with the City of Dallas Water Utilities Division, collected water-quality data from 11 sites on Lake Texoma, a reservoir on the Texas-Oklahoma border, during April 2007-September 2008. At 10 of the sites, physical properties (depth, specific conductance, pH, temperature, dissolved oxygen, and alkalinity) were measured and samples were collected for analysis of selected dissolved constituents (bromide, calcium, magnesium, potassium, sodium, carbonate, bicarbonate, chloride, and sulfate); at one site, only physical properties were measured. The primary constituent of interest was bromide. Bromate can form when ozone is used to disinfect raw water containing bromide, and bromate is a suspected human carcinogen. Chloride and sulfate were of secondary interest. Only the analytical results for bromide, chloride, sulfate, and measured specific conductance are discussed in this report. Median dissolved bromide concentrations ranged from 0.28 to 0.60 milligrams per liter. The largest median dissolved bromide concentration (0.60 milligram per liter at site 11) was from the Red River arm of Lake Texoma. Dissolved bromide concentrations generally were larger in the Red River arm of Lake Texoma than in the Washita arm of the lake. Median dissolved chloride concentrations were largest in the Red River arm of Lake Texoma at site 11 (431 milligrams per liter) and smallest at site 8 (122 milligrams per liter) in the Washita arm. At site 11 in the Red River arm, the mean and median chloride concentrations exceeded the secondary maximum contaminant level of 300 milligrams per liter for chloride established by the 'Texas Surface Water Quality Standards' for surface-water bodies designated for the public water supply use. Median dissolved sulfate concentrations ranged from 182 milligrams per liter at site 4 in the Big Mineral arm to 246 milligrams per liter at site 11 in the Red River arm. None of the mean or median sulfate concentrations

  16. Studies on Cytotoxic Activity against HepG-2 Cells of Naphthoquinones from Green Walnut Husks of Juglans mandshurica Maxim.

    PubMed

    Zhou, Yuanyuan; Yang, Bingyou; Jiang, Yanqiu; Liu, Zhaoxi; Liu, Yuxin; Wang, Xiaoli; Kuang, Haixue

    2015-08-26

    Twenty-seven naphthoquinones and their derivatives, including four new naphthalenyl glucosides and twenty-three known compounds, were isolated from green walnut husks, which came from Juglans mandshurica Maxim. The structures of four new naphthalenyl glucosides were elucidated based on extensive spectroscopic analyses. All of these compounds were evaluated for their cytotoxic activities against the growth of human cancer cells lines HepG-2 by MTT [3-(4,5-dimethylthiazo l-2-yl)-2,5 diphenyl tetrazolium bromide] assay. The results were shown that most naphthoquinones in an aglycone form exhibited better cytotoxicity in vitro than naphthalenyl glucosides with IC50 values in the range of 7.33-88.23 μM. Meanwhile, preliminary structure-activity relationships for these compounds were discussed.

  17. In vitro susceptibility of Pythium insidiosum to macrolides and tetracycline antibiotics.

    PubMed

    Loreto, Erico Silva; Mario, Débora Alves Nunes; Denardi, Laura Bedin; Alves, Sydney Hartz; Santurio, Janio Morais

    2011-07-01

    We describe the in vitro activity of macrolides and tetracycline antibiotics against Pythium insidiosum. The MICs were determined according to CLSI procedures (visual MIC) and by a colorimetric method [3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT)]. The lowest geometric mean (GM) MIC (MICs in μg/ml) (0.39 and 0.7 by visual reading and colorimetric method, respectively) and MIC ranges (0.125 to 2.0) were obtained for minocycline, while the highest MICs were shown for erythromycin (GM of 7.58 and 12.25 by visual reading and colorimetric method, respectively, and MIC ranged from 2 to 32). This significant in vitro activity makes these classes of antibiotics good candidates for experimental treatment of pythiosis. PMID:21537028

  18. In Vitro Susceptibility of Pythium insidiosum to Macrolides and Tetracycline Antibiotics ▿

    PubMed Central

    Loreto, Érico Silva; Mario, Débora Alves Nunes; Denardi, Laura Bedin; Alves, Sydney Hartz; Santurio, Janio Morais

    2011-01-01

    We describe the in vitro activity of macrolides and tetracycline antibiotics against Pythium insidiosum. The MICs were determined according to CLSI procedures (visual MIC) and by a colorimetric method [3-(4,5-dimethyl-2-thiazyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT)]. The lowest geometric mean (GM) MIC (MICs in μg/ml) (0.39 and 0.7 by visual reading and colorimetric method, respectively) and MIC ranges (0.125 to 2.0) were obtained for minocycline, while the highest MICs were shown for erythromycin (GM of 7.58 and 12.25 by visual reading and colorimetric method, respectively, and MIC ranged from 2 to 32). This significant in vitro activity makes these classes of antibiotics good candidates for experimental treatment of pythiosis. PMID:21537028

  19. Data in support of Gallium (Ga(3+)) antibacterial activities to counteract E. coli and S. epidermidis biofilm formation onto pro-osteointegrative titanium surfaces.

    PubMed

    Cochis, A; Azzimonti, B; Sorrentino, R; Della Valle, C; De Giglio, E; Bloise, N; Visai, L; Bruni, G; Cometa, S; Pezzoli, D; Candiani, G; Rimondini, L; Chiesa, R

    2016-03-01

    This paper contains original data supporting the antibacterial activities of Gallium (Ga(3+))-doped pro-osteointegrative titanium alloys, obtained via Anodic Spark Deposition (ASD), as described in "The effect of silver or gallium doped titanium against the multidrug resistant Acinetobacter baumannii" (Cochis et al. 2016) [1]. In this article we included an indirect cytocompatibility evaluation towards Saos2 human osteoblasts and extended the microbial evaluation of the Ga(3+) enriched titanium surfaces against the biofilm former Escherichia coli and Staphylococcus epidermidis strains. Cell viability was assayed by the Alamar Blue test, while bacterial viability was evaluated by the metabolic colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Finally biofilm morphology was analyzed by Scanning Electron Microscopy (SEM). Data regarding Ga(3+) activity were compared to Silver.

  20. Synthesis and characterization of Bodipy functionalized magnetic iron oxide nanoparticles for potential bioimaging applications.

    PubMed

    Topel, Seda Demirel; Topel, Önder; Bostancıoğlu, R Beklem; Koparal, A Tansu

    2015-04-01

    Multifunctional magnetic nanoparticles were synthesized for potential bio-imaging applications. Uniform PEI coated magnetic Fe3O4 (PEI-Fe3O4) nanoparticles were prepared by a modified co-precipitation method and then covalently conjugated with a fluorophore molecule, Bodipy-5 by the DCC/DMAP coupling reaction. The covalent binding of Bodipy-5 to the PEI coated magnetic Fe3O4 nanoparticles were confirmed by means of FTIR and XPS measurements. The imaging ability of the Bodipy coated magnetic nanoparticles was determined on two human cancer cells, A549 (human lung adenocarcinoma epithelial) and Ishikawa (endometrial adenocarcinoma), for the first time. Cytotoxicity of BOD-MNPs was evaluated in both cancer cells and healthy human umbilical vein endothelial cell line (HUVEC) by standard MTT (3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay. In vitro activities of the nanoparticles were also investigated.

  1. Cytotoxicity of macrolide antibiotics in a cultured human liver cell line.

    PubMed

    Viluksela, M; Vainio, P J; Tuominen, R K

    1996-09-01

    Cytotoxicity of erythromycin base, erythromycin estolate, erythromycin-11,12-cyclic carbonate, roxithromycin, clarithromycin and azithromycin was compared in cultured human non-malignant Chang liver cells using reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and cellular protein concentration as end points of toxicity. Erythromycin estolate was the most toxic macrolide in all tests differing clearly from all the other macrolides studied. Erythromycin-11,12-cyclic carbonate was also more toxic than the other macrolides. Roxithromycin and clarithromycin were the next toxic derivatives, while erythromycin base and azithromycin were least toxic. Thus, cytotoxicity of the new semisynthetic macrolides, roxithromycin, clarithromycin and azithromycin, is not substantially different from that of erythromycin base. In view of the low level of hepatotoxicity of macrolides hitherto reported in humans, the results do not suggest any substantial risk for hepatic disorders related to the use of azithromycin, clarithromycin and roxithromycin.

  2. Data in support of Gallium (Ga3+) antibacterial activities to counteract E. coli and S. epidermidis biofilm formation onto pro-osteointegrative titanium surfaces

    PubMed Central

    Cochis, A.; Azzimonti, B.; Sorrentino, R.; Della Valle, C.; De Giglio, E.; Bloise, N.; Visai, L.; Bruni, G.; Cometa, S.; Pezzoli, D.; Candiani, G.; Rimondini, L.; Chiesa, R.

    2016-01-01

    This paper contains original data supporting the antibacterial activities of Gallium (Ga3+)-doped pro-osteointegrative titanium alloys, obtained via Anodic Spark Deposition (ASD), as described in “The effect of silver or gallium doped titanium against the multidrug resistant Acinetobacter baumannii” (Cochis et al. 2016) [1]. In this article we included an indirect cytocompatibility evaluation towards Saos2 human osteoblasts and extended the microbial evaluation of the Ga3+ enriched titanium surfaces against the biofilm former Escherichia coli and Staphylococcus epidermidis strains. Cell viability was assayed by the Alamar Blue test, while bacterial viability was evaluated by the metabolic colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Finally biofilm morphology was analyzed by Scanning Electron Microscopy (SEM). Data regarding Ga3+ activity were compared to Silver. PMID:26909385

  3. Celecoxib, a COX-2 Selective Inhibitor, Induces Cell Cycle Arrest at the G2/M Phase in HeLa Cervical Cancer Cells.

    PubMed

    Setiawati, Agustina; Setiawati, Agustina

    2016-01-01

    Celecoxib, a selective inhibitor of COX-2, showed cytotoxic effects in many cancer cell lines including cervical cancer cells. This study investigated the effect of celecoxib on cell cycle arrest in HeLa cervical cancer cells through p53 expression. In vitro anticancer activity was determined with the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method. A double staining method was applied to investigate the mechanism of cell death, cell cycling was analyzed by flow cytometryand immunocytochemistry was employed to stain p53 expression in cells. Celecoxib showed strong cytotoxic effects and induced apoptosis with an IC50 value of 40 μM. It induced cell cycle arrest at G2/M phase by increasing level of p53 expression on HeLa cells. PMID:27221835

  4. Biocompatibility studies of polyacrylonitrile membranes modified with carboxylated polyetherimide.

    PubMed

    Senthilkumar, S; Rajesh, S; Jayalakshmi, A; Mohan, D

    2013-10-01

    Poly (ether-imide) (PEI) was carboxylated and used as the hydrophilic modification agent for the preparation of polyacrylonitrile (PAN) membranes. Membranes were prepared with different blend compositions of PAN and CPEI by diffusion induced precipitation. The modified membranes were characterized by thermo gravimetric analysis (TGA), mechanical analysis, scanning electron microscopy (SEM) and contact angle measurement to understand the influence of CPEI on the properties of the membranes. The biocompatibility studies exhibited reduced plasma protein adsorption, platelet adhesion and thrombus formation on the modified membrane surface. The complete blood count (CBC) results of CPEI incorporated membranes showed stable CBC values and significant decrease in the complement activation were also observed. In addition to good cytocompatibility, monocytes cultured on these modified membranes exhibited improved functional profiles in 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Thus it could be concluded that PAN/CPEI membranes with excellent biocompatibility can be useful for hemodialysis. PMID:23910257

  5. Scopararanes C-G: new oxygenated pimarane diterpenes from the marine sediment-derived fungus Eutypella scoparia FS26.

    PubMed

    Sun, Li; Li, Dongli; Tao, Meihua; Chen, Yuchan; Dan, Feijun; Zhang, Weimin

    2012-03-01

    Five new oxygenated pimarane diterpenes, named scopararanes C-G (1-5) were isolated from the culture of a marine sediment-derived fungus Eutypella scoparia FS26 obtained from the South China Sea. The structures of these compounds were established on the basis of extensive spectroscopic analysis. The absolute configurations of compounds 1-5, were determined by CD spectroscopic analysis and comparison with literature data. All isolated compounds (1-5) were evaluated for their cytotoxic activities against MCF-7, NCI-H460, and SF-268 tumor cell lines by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) method. PMID:22611352

  6. Sensitive detection of PDT-induced cell damages with luminescent oxygen nanosensors

    NASA Astrophysics Data System (ADS)

    Ma, Hong-Ru; Peng, Hong-shang; You, Fang-tian; Ping, Jian-tao; Zhou, Chao; Guo, Lan-ying

    2016-09-01

    In this work luminescent nanosensors specifically created for intracellular oxygen (ic-O2) were utilized to assess photodynamic therapy (PDT) -induced cell damages. Firstly, ic-O2 was demonstrated to be consumed much faster than extracellular O2 with respective O2 nanosensors. Using the ic-O2 nanosensors, PDT-treated cells with different degree of impairment were then resolved according to the oxygen consumption rate (OCR). The evolving trend of cytotoxicity derived from OCRs was in agreement with cell viability obtained from 3-(4,5-cimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Moreover, the direct damage of PDT on cell mitochondria was successfully detected by monitoring respiration instantly after PDT treatment, which is actually beyond the scope of MTT assay. These results suggest that fluorescence sensing of ic-O2-associated cell respiration is promising and even may become a standardized method, complementary to MTT assay, to evaluate PDT-induced cytotoxicity.

  7. Molecular docking study, synthesis and biological evaluation of Schiff bases as Hsp90 inhibitors.

    PubMed

    Dutta Gupta, Sayan; Snigdha, D; Mazaira, Gisela I; Galigniana, Mario D; Subrahmanyam, C V S; Gowrishankar, N L; Raghavendra, N M

    2014-04-01

    Heat shock protein 90 (Hsp90) is an emerging attractive target for the discovery of novel cancer therapeutic agents. Docking methods are powerful in silico tools for lead generation and optimization. In our mission to rationally develop novel effective small molecules against Hsp90, we predicted the potency of our designed compounds by Sybyl surflex Geom X docking method. The results of the above studies revealed that Schiff bases derived from 2,4-dihydroxy benzaldehyde/5-chloro-2,4-dihydroxy benzaldehyde demonstrated effective binding with the protein. Subsequently, a few of them were synthesized (1-10) and characterized by IR, (1)HNMR and mass spectral analysis. The synthesized molecules were evaluated for their potential to suppress Hsp90 ATPase activity by Malachite green assay. The anticancer studies were performed by 3-(4,5-dimethythiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay method. The software generated results was in satisfactory agreement with the evaluated biological activity.

  8. Data in support of Gallium (Ga(3+)) antibacterial activities to counteract E. coli and S. epidermidis biofilm formation onto pro-osteointegrative titanium surfaces.

    PubMed

    Cochis, A; Azzimonti, B; Sorrentino, R; Della Valle, C; De Giglio, E; Bloise, N; Visai, L; Bruni, G; Cometa, S; Pezzoli, D; Candiani, G; Rimondini, L; Chiesa, R

    2016-03-01

    This paper contains original data supporting the antibacterial activities of Gallium (Ga(3+))-doped pro-osteointegrative titanium alloys, obtained via Anodic Spark Deposition (ASD), as described in "The effect of silver or gallium doped titanium against the multidrug resistant Acinetobacter baumannii" (Cochis et al. 2016) [1]. In this article we included an indirect cytocompatibility evaluation towards Saos2 human osteoblasts and extended the microbial evaluation of the Ga(3+) enriched titanium surfaces against the biofilm former Escherichia coli and Staphylococcus epidermidis strains. Cell viability was assayed by the Alamar Blue test, while bacterial viability was evaluated by the metabolic colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Finally biofilm morphology was analyzed by Scanning Electron Microscopy (SEM). Data regarding Ga(3+) activity were compared to Silver. PMID:26909385

  9. Ex vivo uranium decontamination efficiency on wounded skin and in vitro skin toxicity of a calixarene-loaded nanoemulsion.

    PubMed

    Grives, Sophie; Phan, Guillaume; Morat, Guillaume; Suhard, David; Rebiere, Francois; Fattal, Elias

    2015-06-01

    The present work aims at studying the decontamination efficacy of a calixarene-loaded nanoemulsion on two ex vivo wounded skin models mimicking superficial stings or cuts contaminated with uranium, and on a third model using excoriation. The decontaminating formulation was compared with the currently used radio-decontaminating soapy water (Trait rouge®) treatment. Moreover, to assess skin damage potentially induced by the undiluted nanoemulsion, in vitro toxicity studies were conducted on an in vitro reconstructed human epidermis, coupled with three different toxicity tests [3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide, lactate dehydrogenase, and interleukin-1-α]. This work demonstrated not only a significant decontamination activity of the calixarene nanoemulsion on wounded skin, ranging from 92% to 94% of the applied uranium solution according to the ex vivo model used, but also the absence of side effects of this promising treatment.

  10. 40 CFR 180.123a - Inorganic bromide residues in peanut hay and peanut hulls; statement of policy.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Inorganic bromide residues in peanut hay and peanut hulls; statement of policy. 180.123a Section 180.123a Protection of Environment... RESIDUES IN FOOD Specific Tolerances § 180.123a Inorganic bromide residues in peanut hay and peanut...

  11. 40 CFR 180.123a - Inorganic bromide residues in peanut hay and peanut hulls; statement of policy.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 24 2011-07-01 2011-07-01 false Inorganic bromide residues in peanut hay and peanut hulls; statement of policy. 180.123a Section 180.123a Protection of Environment... RESIDUES IN FOOD Specific Tolerances § 180.123a Inorganic bromide residues in peanut hay and peanut...

  12. A general synthesis of fluoroalkylated alkenes by palladium-catalyzed Heck-type reaction of fluoroalkyl bromides.

    PubMed

    Feng, Zhang; Min, Qiao-Qiao; Zhao, Hai-Yang; Gu, Ji-Wei; Zhang, Xingang

    2015-01-19

    An efficient palladium-catalyzed Heck-type reaction of fluoroalkyl halides, including perfluoroalkyl bromides, trifluoromethyl iodides, and difluoroalkyl bromides, has been developed. The reaction proceeds under mild reaction conditions with high efficiency and broad substrate scope, and provides a general and straightforward access to fluoroalkylated alkenes which are of interest in life and material sciences.

  13. Synergistic growth inhibition by sorafenib and vitamin K2 in human hepatocellular carcinoma cells

    PubMed Central

    Zhang, Yafei; Zhang, Bicheng; Zhang, Anran; Zhao, Yong; Zhao, Jie; Liu, Jian; Gao, Jianfei; Fang, Dianchun; Rao, Zhiguo

    2012-01-01

    OBJECTIVE: Sorafenib is an oral multikinase inhibitor that has been proven effective as a single-agent therapy in hepatocellular carcinoma, and there is a strong rationale for investigating its use in combination with other agents. Vitamin K2 is nearly non-toxic to humans and has been shown to inhibit the growth of hepatocellular carcinoma. In this study, we evaluated the effects of a combination of sorafenib and vitamin K2 on the growth of hepatocellular carcinoma cells. METHODS: Flow cytometry, 3-(4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2H-tetrazolium bromide) and nude mouse xenograft assays were used to examine the effects of sorafenib and vitamin K2 on the growth of hepatocellular carcinoma cells. Western blotting was used to elucidate the possible mechanisms underlying these effects. RESULTS: Assays for 3-(4,5-dimethyl-2-thiazolyl-2,5-diphenyl-2H-tetrazolium bromide) revealed a strong synergistic growth-inhibitory effect between sorafenib and vitamin K2. Flow cytometry showed an increase in cell cycle arrest and apoptosis after treatment with a combination of these two drugs at low concentrations. Sorafenib-mediated inhibition of extracellular signal-regulated kinase phosphorylation was promoted by vitamin K2, and downregulation of Mcl-1, which is required for sorafenib-induced apoptosis, was observed after combined treatment. Vitamin K2 also attenuated the downregulation of p21 expression induced by sorafenib, which may represent the mechanism by which vitamin K2 promotes the inhibitory effects of sorafenib on cell proliferation. Moreover, the combination of sorafenib and vitamin K2 significantly inhibited the growth of hepatocellular carcinoma xenografts in nude mice. CONCLUSIONS: Our results determined that combined treatment with sorafenib and vitamin K2 can work synergistically to inhibit the growth of hepatocellular carcinoma cells. This finding raises the possibility that this combined treatment strategy might be promising as a new therapy against

  14. Integrin-linked kinase affects signaling pathways and migration in thyroid cancer cells and is a potential therapeutic target

    PubMed Central

    Shirley, Lawrence A.; McCarty, Samantha; Yang, Ming-Chen; Saji, Motoyasu; Zhang, Xiaoli; Phay, John; Ringel, Matthew D.; Chen, Ching-Shih

    2016-01-01

    Background Integrin-linked kinase (ILK) is a serine-threonine kinase that regulates interactions between the cell and the extracellular matrix. In many cancers, overexpression of ILK leads to increased cell proliferation, motility, and invasion. We hypothesized that ILK functions as a regulator of viability and migration in thyroid cancer cells. Methods Eleven human thyroid cancer cell lines were screened for ILK protein expression. The cell lines with the greatest expression were treated with either ILK small interfering RNA (siRNA) or a novel ILK inhibitor, T315, and the effects were evaluated via Western blot and migration assay. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assays were performed to assess cell viability. Results siRNA against ILK decreased phosphorylation of downstream effectors Akt and MLC, as well as decreased migration. Treatment with T315 showed a dose-related decrease in both Akt and MLC phosphorylation, as well as decreased migration. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assays showed T315 to have an half maximal inhibitory concentration of less than 1 µM in cell lines with high ILK expression. Conclusion ILK is expressed differentially in thyroid cancer cell lines. Both ILK siRNA and T315 inhibit motility of thyroid cancer cell lines, and T315 is shown to be cytotoxic at low concentrations. Altogether, our study suggests that ILK may represent an important kinase in aggressive thyroid cancers. PMID:26549818

  15. Inhibitory and Cytotoxic Activities of Chrysin on Human Breast Adenocarcinoma Cells by Induction of Apoptosis

    PubMed Central

    Samarghandian, Saeed; Azimi-Nezhad, Mohsen; Borji, Abasalt; Hasanzadeh, Malihe; Jabbari, Farahzad; Farkhondeh, Tahereh; Samini, Mohammad

    2016-01-01

    Objectives: Chrysin, an active natural bioflavonoid found in honey and many plant extracts, was first known for its antioxidant and anti-inflammatory effects. The fact that antioxidants have several inhibitory effects against different diseases, such as cancer, led to search for food rich in antioxidants. In this study, we investigated the antiproliferative and apoptotic effects of chrysin on the cultured human breast cancer cells (MCF-7). Materials and Methods: Cells were cultured in Roswell Park Memorial Institute medium and treated with different chrysin concentrations for three consecutive days. Cell viability was quantitated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The percentage of apoptotic cells was determined by flow cytometry using Annexin V-fluorescein isothiocyanate. Results: The MTT assay showed that chrysin had an antiproliferative effect on MCF-7 cells in a dose- and time-dependent manner. The 50% cell growth inhibition values for chrysin against MCF-7 cells were 19.5 and 9.2 μM after 48 and 72 h, respectively. Chrysin induced apoptosis in MCF-7 cells as determined by flow cytometry. Chrysin inhibits the growth of the breast cancer cells by inducing cancer cell apoptosis which may, in part, explain its anticancer activity. Conclusion: This study shows that chrysin could also be considered as a promising chemotherapeutic agent and anticancer activity in treatment of the breast cancer cells in future. SUMMARY Chrysin had an antiproliferative effect on human breast cancer cells (MCF-7) cells in a dose- and time-dependent mannerChrysin induced apoptosis in MCF-7 cells, as determined by flow cytometryChrysin inhibits the growth of the breast cancer cells by inducing cancer cell apoptosisChrysin may have anticancer activity. Abbreviations used: Human breast cancer cells (MCF-7), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), phosphate-buffered saline (PBS), normal fibroblast mouse (L929). PMID

  16. Tobacco Dust Induced Genotoxicity as an Occupational Hazard in Workers of Bidi Making Cottage Industry of Central India

    PubMed Central

    Khanna, Asha; Gautam, Daya Shankar; Gokhale, Mamta; Jain, Salil Kumar

    2014-01-01

    Context: To explore genotoxicity in bidi rollers occupationally exposed to bidi tobacco dust. Aims: To assess the extent of genotoxicity of tobacco dust to bidi rollers of Jabalpur, Madhya Pradesh, India and cytotoxicity of bidi tobacco extract. Settings and Design: Blood samples from 31 bidi rollers and 30 controls taken after written informed consent were analyzed for chromosome aberrations (CA) and comet assay. Materials and Methods: Genotoxicity was studied by CA in cultured peripheral blood lymphocytes of bidi rollers and the deoxyribonucleic acid (DNA) damage studies were done by comet assay of their blood. The toxicity of bidi tobacco extract to normal human lymphocytes was studied by MMT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay as drop in viability. Statistical Analysis Used: Student's t-test and DMRT. Results: There is a general trend of increase in CA% of both in exposed and control groups with age, but in every group the bidi rollers have a significantly higher CA% than the controls. The CA % is also directly related to exposure. The comet assay findings reveal that the mean comet length and tail length increases with exposure time. The toxicity of bidi tobacco extract (TE) to normal human lymphocytes was tested in vitro by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay at 2 h of incubation. The trend of drop in viability with increasing concentrations of TE was clearly evident from the data from four donors in spite of their individual differences in viability. Conclusions: The results obtained in this investigation indicate that bidi rollers seem to be facing the occupational hazard of genotoxicity due to handling bidi tobacco and inhalation of tobacco dust. They should be advised to work under well-ventilated conditions. PMID:24748730

  17. Use of thiazole orange homodimer as an alternative to ethidium bromide for DNA detection in agarose gels.

    PubMed

    Wilke, W W; Heller, M J; Iakoubova, O K; Robinson, R A

    1994-04-01

    Detection of polymerase chain reaction-amplified DNA fragments is commonly accomplished by visualizing the products in electrophoretic agarose beds with the use of ethidium bromide under ultraviolet light. However, ethidium bromide is mutagenic, and special handling and disposal precautions must be used. We report the use of a nonmutagenic dye, thiazole orange dimer (TOTO), which can be substituted for ethidium bromide. The excitation maximum for TOTO under ultraviolet light is 488 nm, and the absorption maximum is 510 nm, necessitating photographic filters different from those used for ethidium bromide for optimal results. Of particular importance in TOTO's use is the quantity used for each gel lane, since excess TOTO will cause unacceptable product mobility retardation. TOTO is only slightly more expensive than ethidium bromide. Overall, this stain provides very good visualization of polymerase chain reaction--amplified DNA bands in agarose gels. We believe the use of this safer reagent will become more widespread with increased regulation of laboratory activities.

  18. 77 FR 48153 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-13

    ... for 2015, Deadline Extension AGENCY: Environmental Protection Agency (EPA). ACTION: Extension to... 2015. On August 3, 2012, EPA received a letter from methyl bromide stakeholders requesting an extension... applicants. Critical Use Exemption Applications for 2015 are now due to the agency on or before August...

  19. Methyl bromide release from activated carbon and the soil/water/carbon interface

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl Bromide (MB) is a major source of stratospheric bromine radical, a known depletor of ozone. The use of ozone-depleting chemicals, including MB, is regulated by the Montreal Protocol. Critical uses of MB are permitted, such as when postharvest fumigation is mandated by an importing country. Fo...

  20. 75 FR 41177 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-15

    ... extent, and by means of the procedures, set forth under 40 CFR part 2 subpart B; 41 FR 36752, 43 FR 40000, 50 FR 51661. If no claim of confidentiality accompanies the information when EPA receives it, EPA may... AGENCY Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption...

  1. Reduced rates and alternatives to methyl bromide for snapdragon production in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A field trial was conducted to evaluate soil solarization, Midas™ (iodomethane:chloropicrin 50:50, Arysta LifeScience Corp., Cary, NC) and different rates and formulations of methyl bromide under standard and metalized films for the production of snapdragon (Antirrhinum majus) in Martin County, Flor...

  2. Quantitative gas chromatographic mass spectrometric determination of pinaverium-bromide in human serum.

    PubMed

    de Weerdt, G A; Beke, R P; Verdievel, H G; Barbier, F; Jonckheere, J A; de Leenheer, A P

    1983-03-01

    A method has been developed for quantitative determination of pinaverium-bromide, a quaternary ammonium derivative with papaverine-like activity, in human serum. The method involves a chloroform extraction of serum spiked with N-(6,6-dimethyl bicyclo[3.1.1]2-heptenyl-ethoxyethyl) perhydro-1,4-oxazine as internal standard. After evaporation of the solvent, and reduction of the residue with Raney-Nickel, the internal standard and the reduced pinaverium-bromide are re-extracted from the reaction mixture with toluene and analysed isothermally on a fused silica column coated with OV-101. Although chemical ionization with methane revealed intense protonated molecular ions for both pinaverium-bromide and the internal standard, selectivity and sensitivity were significantly lower in comparison with electron impact ionization at 70 e V. Therefore, quantification was performed in the electron impact mode by single ion monitoring of the common fragment ion at m/z 100.2. A linear detector response was observed up to 160 ng ml-1. A within-run assay precision better than 2% CV (n = 5) was found, and a detection limit of 1 ng pinaverium-bromide ml-1 of serum was attained. PMID:6850068

  3. WEED COMMUNITY COMPOSITION IN TREE FRUIT NURSERIES TREATED WITH METHYL BROMIDE AND ALTERNATIVE FUMIGANTS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several agricultural cropping systems, for decades, have relied on methyl bromide (MeBr) for pest control including weeds. Alternative fumigants are being sought worldwide because MeBr has been identified as an ozone-layer depleting substance. Weed communities respond dynamically to alterations in...

  4. Mild Pd-catalyzed aminocarbonylation of (hetero)aryl bromides with a palladacycle precatalyst.

    PubMed

    Friis, Stig D; Skrydstrup, Troels; Buchwald, Stephen L

    2014-08-15

    A palladacyclic precatalyst is employed to cleanly generate a highly active XantPhos-ligated Pd-catalyst. Its use in low temperature aminocarbonylations of (hetero)aryl bromides provides access to a range of challenging products in good to excellent yields with low catalyst loading and only a slight excess of CO. Some products are unattainable by traditional carbonylative coupling.

  5. Effects of intraoperative magnetic resonance imaging on the neuromuscular blockade of vecuronium bromide in neurosurgery.

    PubMed

    Guo, Ying; Zhang, Hong; Sun, Li

    2013-01-01

    The effects of intraoperative magnetic resonance (iMR) imaging on the neuromuscular blockade of vecuronium bromide were investigated in neurosurgery. Fifty patients with American Society of Anesthesiologists grades I-II scheduled for craniotomy operation were divided into two groups (n = 25 each) with no difference in demographic data: the iMR imaging group and control group. Train-of-four (TOF) stimulation through an accelerometer was used to monitor onset, maintenance, and recovery of muscle relaxation caused by vecuronium. Vecuronium bromide was intravenously injected after anesthesia induction. The dosage of vecuronium bromide in the iMR imaging group was larger than in the control group, but not significantly. Duration of vecuronium bromide administration and operation time were significantly longer in the iMR imaging group than in the control group. Time from drug discontinuation to operation termination, and to return to neurosurgery intensive care unit were not different. Time taken by first twitch (T1) in response to TOF stimulation to recover by 25%, and muscle relaxant recovery index were significantly greater in the control group than in the iMR imaging group. The body temperature of the patients increased gradually in the iMR imaging group but decreased in the control group. iMR imaging can prolong the operation time, increase the body temperature of the patient, and remarkably shorten the clinical action time and muscle relaxation recovery index of vecuronium.

  6. Forest nurseries face critical choices with the loss of methyl bromide fumigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forest nurseries in the western United States have relied for decades on methyl bromide for the control of soilborne pathogens such as Cylindrocarpoin, Fusarium, and Pythium species that affect bareroot tree seedling production. However, increased state and federal regulations have led to a substan...

  7. Recovery of bromine from methyl bromide using amorphous MnO{sub x} photocatalysts

    SciTech Connect

    Lin, Jung-Chou; Suib, S.L.; Cutlip, M.B.

    1996-07-01

    Amorphous MnO{sub x} (AMO) has been prepared by the reaction of potassium permanganate and oxalic acid. Surface area measurements and pore size distribution analyses show that AMO has high surface (200 m{sup 2}/g) area and a microporous structure. Kinetic results indicate that methyl bromide degradation using AMO photocatalysts is due to a combination of thermocatalytic and photocatalytic reactions; however, the photocatalytic reaction is predominant. Detailed studies show that both molecular oxygen and bulk lattice oxygen of AMO can be involved in the oxidation of methyl bromide to carbon dioxide. Kinetic data, Auger analyses, and FTIR spectra suggest that both oxidation state changes of Mn and the presence of bromide adsorbed on the surface might lead to deactivation of the catalyst. According to mass balance calculations and analyses with potassium iodide solutions with starch, the final products are bromine, carbon dioxide, and water. The overall reaction for methyl bromide degradation under illumination using AMO photocatalyst can be expressed as CH{sub 3}Br{sub (g)} + 7/4O{sub 2(g)} {yields} CO{sub 2(g)} + 3/2H{sub 2}O(g) + {1/2}Br{sub 2(g)}. 27 refs., 10 figs., 2 tabs.

  8. 77 FR 29341 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-17

    ... to the provisions of the Montreal Protocol on Substances that Deplete the Ozone Layer for... AGENCY Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications... FURTHER INFORMATION CONTACT: General Information: U.S. EPA Stratospheric Ozone Information Hotline,...

  9. Methyl bromide and sulfuryl fluoride effectiveness against red flour beetle life stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of methyl bromide (MB) and sulfuryl fluoride (SF) for managing all life stages of the red flour beetle, Tribolium castaneum, was investigated in the Hal Ross Flour Mill at Kansas State University. Eggs, young larvae, large larvae, pupae, and adults confined in plastic compartments with ...

  10. Steam disinfestation as a methyl bromide alternative in California cut flower nurseries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Steam may be an effective alternative to methyl bromide in cut flower production in California. Advantages of steam include broad spectrum pest control and a zero hour re-entry interval. The principle disadvantage of sheet steaming is cost effectiveness due to current energy prices and application...

  11. Evaluation of Reduced Methyl Bromide Rates in Field Grown Perennial Crop Nurseries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Preplant soil fumigation with methyl bromide (MB) has commonly been used in field grown nursery crops to provide broad-spectrum control of plant parasitic nematodes, disease pathogens, and weed propagules. Although MB use was officially phased out in 2005 due to negative effects on stratospheric oz...

  12. Hydrology and Water Quality near Bromide Pavilion in Chickasaw National Recreation Area, Murray County, Oklahoma, 2000

    USGS Publications Warehouse

    Andrews, William J.; Burrough, Steven P.

    2002-01-01

    The Bromide Pavilion in Chickasaw National Recreation Area drew many thousands of people annually to drink the mineral-rich waters piped from nearby Bromide and Medicine Springs. Periodic detection of fecal coliform bacteria in water piped to the pavilion from the springs, low yields of the springs, or flooding by adjacent Rock Creek prompted National Park Service officials to discontinue piping of the springs to the pavilion in the 1970s. Park officials would like to resume piping mineralized spring water to the pavilion to restore it as a visitor attraction, but they are concerned about the ability of the springs to provide sufficient quantities of potable water. Pumping and sampling of Bromide and Medicine Springs and Rock Creek six times during 2000 indicate that these springs may not provide sufficient water for Bromide Pavilion to supply large numbers of visitors. A potential problem with piping water from Medicine Spring is the presence of an undercut, overhanging cliff composed of conglomerate, which may collapse. Evidence of intermittent inundation of the springs by Rock Creek and seepage of surface water into the spring vaults from the adjoining creek pose a threat of contamination of the springs. Escherichia coli, fecal coliform, and fecal streptococcal bacteria were detected in some samples from the springs, indicating possible fecal contamination. Cysts of Giardia lamblia and oocysts of Cryptosporidium parvum protozoa were not detected in the creek or the springs. Total culturable enteric viruses were detected in only one water sample taken from Rock Creek.

  13. Experimental study of negative temperatures in lithium-bromide absorption refrigerating machines

    NASA Astrophysics Data System (ADS)

    Stepanov, K. I.; Mukhin, D. G.; Alekseenko, S. V.; Volkova, O. V.

    2015-07-01

    The authors have developed a method and presented experimental data for obtaining negative temperatures of evaporation in lithium-bromide absorption chillers driven by heat recovery. It has been found that the attainable temperature of the refrigerated medium is the value of -5 °C.

  14. 76 FR 29238 - Methyl Bromide; Cancellation Order for Registration Amendments To Terminate Certain Soil Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-20

    ... provided, EPA received no comments in response to the February 9, 2011, Federal Register notice (76 FR 7200... AGENCY Methyl Bromide; Cancellation Order for Registration Amendments To Terminate Certain Soil Uses... for the amendments to terminate soil uses, voluntarily requested by the registrants and accepted...

  15. A facile one-pot synthesis of deep blue luminescent lead bromide perovskite microdisks.

    PubMed

    Yuan, Zhao; Shu, Yu; Tian, Yu; Xin, Yan; Ma, Biwu

    2015-11-25

    We report a facile one-pot synthetic method to prepare highly luminescent layered lead(II) bromide perovskite microdisks with the lateral size of a few micrometers and thickness of 100-150 nm, featuring narrow deep blue emissions with quantum yields of up to 53% in toluene solutions and thin films at room temperature.

  16. OZONATION BYPRODUCTS: IDENTIFICATION OF BROMOHYDRINS FROM THE OZONATION OF NATURAL WATERS WITH ENHANCED BROMIDE LEVELS

    EPA Science Inventory

    When ozone is used in the treatment of drinking water, it reacts with both inorganic and organic compounds to form byproducts. f bromide is present, it may be oxidized to hydrobromous acid, which may than react with natural organic matter to form brominated organic compounds. he ...

  17. Effect of increasing bromide concentration on toxicity in treated drinking water.

    PubMed

    Sawade, Emma; Fabris, Rolando; Humpage, Andrew; Drikas, Mary

    2016-04-01

    Research is increasingly indicating the potential chronic health effects of brominated disinfection by-products (DBPs). This is likely to increase with elevated bromide concentrations resulting from the impacts of climate change, projected to include extended periods of drought and the sudden onset of water quality changes. This will demand more rigorous monitoring throughout distribution systems and improved water quality management at water treatment plants (WTPs). In this work the impact of increased bromide concentration on formation of DBPs following conventional treatment and chlorination was assessed for two water sources. Bioanalytical tests were utilised to determine cytotoxicity of the water post disinfection. Coagulation was shown to significantly reduce the cytotoxicity of the water, indicating that removal of natural organic matter DBP precursors continues to be an important factor in drinking water treatment. Most toxic species appear to form within the first half hour following disinfectant addition. Increasing bromide concentration across the two waters was shown to increase the formation of trihalomethanes and shifted the haloacetic acid species distribution from chlorinated to those with greater bromine substitution. This correlated with increasing cytotoxicity. This work demonstrates the challenges faced by WTPs and the possible effects increasing levels of bromide in source waters could have on public health.

  18. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... additives, bromide ion and residual bromine, may be present in water, potable in accordance with the following conditions: (1) The food additives are present as a result of treating water aboard ships with a...) Residual bromine levels are controlled to not exceed 1.0 part per million (ppm) in the final treated...

  19. Bromate formation from bromide oxidation by the UV/persulfate process.

    PubMed

    Fang, Jing-Yun; Shang, Chii

    2012-08-21

    Bromate formation from bromide oxidation by the UV/persulfate process was investigated, along with changes in pH, persulfate dosages, and bromide concentrations in ultrapure water and in bromide-spiked real water. In general, the bromate formation increased with increasing persulfate dosage and bromide concentration. The bromate formation was initiated and primarily driven by sulfate radicals (SO(4)(•-)) and involved the formation of hypobromous acid/hypobromite (HOBr/OBr(-)) as an intermediate and bromate as the final product. Under the test conditions, the rate of the first step driven by SO(4)(•-) is slower than that of the second step. Direct UV photolysis of HOBr/OBr(-) to form bromate and the photolysis of bromate are insignificant. The bromate formation was similar for pH 4-7 but decreased over 90% with increasing pH from 7 to above 9. Less bromate was formed in the real water sample than in ultrapure water, which was primarily attributable to the presence of natural organic matter that reacts with bromine atoms, HOBr/OBr(-) and SO(4)(•-). The extent of bromate formation and degradation of micropollutants are nevertheless coupled processes unless intermediate bromine species are consumed by NOM in real water. PMID:22831804

  20. Effect of increasing bromide concentration on toxicity in treated drinking water.

    PubMed

    Sawade, Emma; Fabris, Rolando; Humpage, Andrew; Drikas, Mary

    2016-04-01

    Research is increasingly indicating the potential chronic health effects of brominated disinfection by-products (DBPs). This is likely to increase with elevated bromide concentrations resulting from the impacts of climate change, projected to include extended periods of drought and the sudden onset of water quality changes. This will demand more rigorous monitoring throughout distribution systems and improved water quality management at water treatment plants (WTPs). In this work the impact of increased bromide concentration on formation of DBPs following conventional treatment and chlorination was assessed for two water sources. Bioanalytical tests were utilised to determine cytotoxicity of the water post disinfection. Coagulation was shown to significantly reduce the cytotoxicity of the water, indicating that removal of natural organic matter DBP precursors continues to be an important factor in drinking water treatment. Most toxic species appear to form within the first half hour following disinfectant addition. Increasing bromide concentration across the two waters was shown to increase the formation of trihalomethanes and shifted the haloacetic acid species distribution from chlorinated to those with greater bromine substitution. This correlated with increasing cytotoxicity. This work demonstrates the challenges faced by WTPs and the possible effects increasing levels of bromide in source waters could have on public health. PMID:27105403

  1. Headspace gas chromatographic method for determination of methyl bromide in food ingredients

    SciTech Connect

    DeVries, J.W.; Broge, J.M.; Schroeder, J.P.; Bowers, R.H.; Larson, P.A.; Burns, N.M.

    1985-11-01

    A headspace gas chromatographic (GC) method, which can be automated, has been developed for determination of methyl bromide. This method has been applied to wheat, flour, cocoa, and peanuts. Samples to be analyzed are placed in headspace sample vials, water is added, and the vials are sealed with Teflon-lined septa. After an appropriate equilibration time at 32 degrees C, the samples are analyzed within 10 h. A sample of the headspace is withdrawn and analyzed on a gas chromatograph equipped with an electron capture detector (ECD). Methyl bromide levels were quantitated by comparison of peak area with a standard. The standard was generated by adding a known amount of methyl bromide to a portion of the matrix being analyzed and which was known to be methyl bromide free. The detection limit of the method was 0.4 ppb. The coefficient of variation (CV) was 6.5% for wheat, 8.3% for flour, 3.3% for cocoa, and 11.6% for peanuts.

  2. TRIBROMOPYRROLE, BROMINATED ACIDS, AND OTHER DISINFECTION BYPRODUCTS PRODUCED BY DISINFECTION OF DRINKING WATER RICH IN BROMIDE

    EPA Science Inventory

    Using gas chromatography/mass spectrometry (GC/MS), we investigated the formation of disinfection byproducts (DBPs) from high bromide waters (2 mg/L) treated with chlorine or chlorine dioxide used in combination with chlorine and chloramines. This study represents the first comp...

  3. Copper-catalyzed conversion of aryl and heteroaryl bromides into the corresponding chlorides.

    PubMed

    Feng, Xiujuan; Qu, Yiping; Han, Yanlei; Yu, Xiaoqiang; Bao, Ming; Yamamoto, Yoshinori

    2012-10-01

    An efficient method for the synthesis of aryl and heteroaryl chlorides is described. The reactions of aryl and heteroaryl bromides with tetramethylammonium chloride proceeded smoothly in the presence of a copper catalyst under mild reaction conditions to produce the corresponding chlorides in satisfactory to excellent yields. PMID:22895409

  4. EVALUATION OF CONTAINMENT AND CONTROL OPTIONS FOR METHYL BROMIDE IN COMMODITY TREATMENT

    EPA Science Inventory

    The report gives results of an investigation of means for methyl bromide (MeBr) recovery, reuse, and destruction to prevent atmospheric emissions if its limited use were still allowed. (NOTE: MeBr is an ozone-depleting chemical scheduled to be phased out by the Clean Air Act by t...

  5. [Effectiveness of pinaverium bromide therapy on colonic motility disorders in irritable bowel syndrome].

    PubMed

    Wittmann, T; Fehér, A; Rosztóczy, A; Jánosi, J

    1999-02-28

    The special patterns of the slow wave activity in irrittable bowel syndrome by means of surface electromyography were examined and the effect of pinaverium bromide on the symptoms and on the colonic motility in this disease was estimated. Twenty two patients with irritable bowel syndrome and 7 healthy controls were selected to the study. The clinical symptoms were abdominal pain and bloating in all patients, constipation in 9, and diarrhoea in 6 cases. Surface electromyography was carried out before and on the 14th day of the treatment with pinaverium bromide (50 mg t. i. d). The colonic motility was analysed in a 2 hour fasting and a 2 hour postprandial period following a standard (800 kCal) meal. The slow wave frequency of 0.01-0.04 Hz were selected and analysed. The mean frequency of activity peaks (n/10 min) and power-index (area under curve, microV 10 min) were measured. For statistical analysis Student's t-test was applied. Electromyogram of patients with irritable bowel syndrome showed a significant increase of the measured colonic motility parameters both in fasting and postprandial states. Fourteen days of pinaverium bromide treatment was able to significantly reduce the intensity of the colonic motor activity. Administration of pinaverium bromide completely released in 6 and significantly improved the abdominal pain in other 12 patients, while the bloating disappeared in 12 and was significantly improved in 5 from 22 patients. Pinaverium bromide was able to normalise the stool frequency: the weekly number of stools was decreased from 16 to 7 in the patients complaining diarrhoea ant it was increased from 2 to 6 in the patients with constipation. PMID:10204402

  6. Kinetics of Chlorination of Benzophenone-3 in the Presence of Bromide and Ammonia.

    PubMed

    Abdallah, Pamela; Deborde, Marie; Dossier Berne, Florence; Karpel Vel Leitner, Nathalie

    2015-12-15

    The aim of this study was to assess the impact of chlorination on the degradation of one of the most commonly used UV filters (benzophenone-3 (BP-3)) and the effects of bromide and ammonia on the kinetics of BP-3 elimination. Bromide and ammonia are rapidly converted to bromine and chloramines during chlorination. At first, the rate constants of chlorine, bromine and monochloramine with BP-3 were determined at various pH levels. BP-3 was found to react rapidly with chlorine and bromine, with values of apparent second order rate constants equal to 1.25(±0.14) × 10(3) M(-1)·s(-1) and 4.04(±0.54) × 10(6) M(-1)·s(-1) at pH 8.5 for kChlorine/BP-3 and kBromine/BP-3, respectively, whereas low monochloramine reactivity was observed (kNH2Cl/BP-3 = 0.112 M(-1)·s(-1)). To assess the impact of the inorganic content of water on BP-3 degradation, chlorination experiments with different added concentrations of bromide and/or ammonia were conducted. Under these conditions, BP-3 degradation was found to be enhanced in the presence of bromide due to the formation of bromine, whereas it was inhibited in the presence of ammonia. However, the results obtained were pH dependent. Finally, a kinetic model considering 18 reactions was developed using Copasi to estimate BP-3 degradation during chlorination in the presence of bromide and ammonia.

  7. Utility of Bromide and Heat Tracers for Aquifer Characterization Affected by Highly Transient Flow Conditions

    SciTech Connect

    Ma, Rui; Zheng, Chunmiao; Zachara, John M.; Tonkin, Matthew J.

    2012-08-29

    A tracer test using both bromide and heat tracers conducted at the Integrated Field Research Challenge site in Hanford 300 Area (300A), Washington, provided an instrument for evaluating the utility of bromide and heat tracers for aquifer characterization. The bromide tracer data were critical to improving the calibration of the flow model complicated by the highly dynamic nature of the flow field. However, most bromide concentrations were obtained from fully screened observation wells, lacking depth-specific resolution for vertical characterization. On the other hand, depth-specific temperature data were relatively simple and inexpensive to acquire. However, temperature-driven fluid density effects influenced heat plume movement. Moreover, the temperature data contained “noise” caused by heating during fluid injection and sampling events. Using the hydraulic conductivity distribution obtained from the calibration of the bromide transport model, the temperature depth profiles and arrival times of temperature peaks simulated by the heat transport model were in reasonable agreement with observations. This suggested that heat can be used as a cost-effective proxy for solute tracers for calibration of the hydraulic conductivity distribution, especially in the vertical direction. However, a heat tracer test must be carefully designed and executed to minimize fluid density effects and sources of noise in temperature data. A sensitivity analysis also revealed that heat transport was most sensitive to hydraulic conductivity and porosity, less sensitive to thermal distribution factor, and least sensitive to thermal dispersion and heat conduction. This indicated that the hydraulic conductivity remains the primary calibration parameter for heat transport.

  8. Kinetics of Chlorination of Benzophenone-3 in the Presence of Bromide and Ammonia.

    PubMed

    Abdallah, Pamela; Deborde, Marie; Dossier Berne, Florence; Karpel Vel Leitner, Nathalie

    2015-12-15

    The aim of this study was to assess the impact of chlorination on the degradation of one of the most commonly used UV filters (benzophenone-3 (BP-3)) and the effects of bromide and ammonia on the kinetics of BP-3 elimination. Bromide and ammonia are rapidly converted to bromine and chloramines during chlorination. At first, the rate constants of chlorine, bromine and monochloramine with BP-3 were determined at various pH levels. BP-3 was found to react rapidly with chlorine and bromine, with values of apparent second order rate constants equal to 1.25(±0.14) × 10(3) M(-1)·s(-1) and 4.04(±0.54) × 10(6) M(-1)·s(-1) at pH 8.5 for kChlorine/BP-3 and kBromine/BP-3, respectively, whereas low monochloramine reactivity was observed (kNH2Cl/BP-3 = 0.112 M(-1)·s(-1)). To assess the impact of the inorganic content of water on BP-3 degradation, chlorination experiments with different added concentrations of bromide and/or ammonia were conducted. Under these conditions, BP-3 degradation was found to be enhanced in the presence of bromide due to the formation of bromine, whereas it was inhibited in the presence of ammonia. However, the results obtained were pH dependent. Finally, a kinetic model considering 18 reactions was developed using Copasi to estimate BP-3 degradation during chlorination in the presence of bromide and ammonia. PMID:26587868

  9. The role of bromide ions in seeding growth of Au nanorods.

    PubMed

    Garg, Niti; Scholl, Clark; Mohanty, Ashok; Jin, Rongchao

    2010-06-15

    We report our findings on the important role of bromide ions in the seeding growth process of Au nanorods. The seed-mediated process constitutes a well-developed method for synthesizing gold nanorods in high yield, which is facilitated by a micelle-forming surfactant, cetyltrimethylammonium bromide (CTA-Br). Despite the tremendous work in recent years, the growth mechanism of Au nanorods has not been fully understood. Contrary to the widely accepted mechanism of CTA(+) micelle-templated growth of Au nanorods, we have identified the critical role of bromide ions in the seeding growth of Au nanorods. We found that even when the micelle-forming agent (CTA(+)) concentration is below its critical micelle concentration (cmc), bromide ions added in the form of NaBr can successfully effect the growth of Au nanorods in good yield. By controlling the concentration of externally added bromide ions, the rod shape and dimensions of the resulting Au nanoparticles can be readily controlled in the presence of only a minimum amount of CTABr (as a steric stabilizer for nanorods). High-resolution TEM studies show that the as-formed nanorods are perfectly single crystalline, instead of penta-twinned ones, and are bound by {111} and {100} facets with a [110] direction as the elongation direction. A mechanism is proposed to account for the seeding growth of single crystalline Au nanorods. Overall, this work explicitly demonstrates that Br(-) indeed serves as an important shape-directing agent for gold nanorod formation in the seed-mediated process. PMID:20394386

  10. Solvation dynamics in aqueous anionic and cationic micelle solutions: sodium alkyl sulfate and alkyltrimethylammonium bromide.

    PubMed

    Tamoto, Yushi; Segawa, Hiroshi; Shirota, Hideaki

    2005-04-26

    Solvation dynamics of the fluorescence probe, coumarin 102, in anionic surfactant, sodium alkyl sulfate (C(n)H(2n+1)SO(4)Na; n = 8, 10, 12, and 14), and cationic surfactant, alkyltrimethylammonium bromide (C(n)H(2n+1)N(CH(3))(3)Br; n = 10, 12, 14, and 16), micelle solutions have been investigated by a picosecond streak camera system. The solvation dynamics in the time range of 10(-10)-10(-8) s is characterized by a biexponential function. The faster solvation time constants are about 110-160 ps for both anionic and cationic micelle solutions, and the slower solvation time constants for sodium alkyl sulfate and alkyltrimethylammonium bromide micelle solutions are about 1.2-2.6 ns and 450-740 ps, respectively. Both the faster and the slower solvation times become slower with longer alkyl chain surfactant micelles. The alkyl-chain-length dependence of the solvation dynamics in both sodium alkyl sulfate and alkyltrimethylammonium bromide micelles can be attributed to the variation of the micellar surface density of the polar headgroup by the change of the alkyl chain length. The slower solvation time constants of sodium alkyl sulfate micelle solutions are about 3.5 times slower than those of alkyltrimethylammonium bromide micelle solutions for the same alkyl-chain-length surfactants. The interaction energies of the geometry optimized mimic clusters (H(2)O-C(2)H(5)SO(4)(-) and H(2)O-C(2)H(5)N(CH(3))(3)(+)) have been estimated by the density functional theory calculations to understand the interaction strengths between water and alkyl sulfate and alkyltrimethylammonium headgroups. The difference of the slower solvation time constants between sodium alkyl sulfate and alkyltrimethylammonium bromide micelle solutions arises likely from their different specific interactions.

  11. Comparative study of β-glucan induced respiratory burst measured by nitroblue tetrazolium assay and real-time luminol-enhanced chemiluminescence assay in common carp (Cyprinus carpio L.).

    PubMed

    Vera-Jimenez, N I; Pietretti, D; Wiegertjes, G F; Nielsen, M E

    2013-05-01

    The respiratory burst is an important feature of the immune system. The increase in cellular oxygen uptake that marks the initiation of the respiratory burst is followed by the production of reactive oxygen species (ROS) such as superoxide anion and hydrogen peroxide which plays a role in the clearance of pathogens and tissue regeneration processes. Therefore, the respiratory burst and associated ROS constitute important indicators of fish health status. This paper compares two methods for quantitation of ROS produced during the respiratory burst in common carp: the widely used, single-point measurement based on the intracellular reduction of nitroblue tetrazolium (NBT) and a real-time luminol-enhanced assay based on the detection of native chemiluminescence. Both assays allowed for detection of dose-dependent changes in magnitude of the respiratory burst response induced by β-glucans in head kidney cells of carp. However, whereas the NBT assay was shown to detect the production of only superoxide anions, the real-time luminol-enhanced assay could detect the production of both superoxide anions and hydrogen peroxide. Only the chemiluminescence assay could reliably record the production of ROS on a real-time scale at frequent and continual time intervals for time course experiments, providing more detailed information on the respiratory burst response. The real-time chemiluminescence assay was used to measure respiratory burst activity in macrophage and neutrophilic granulocyte-enriched head kidney cell fractions and total head kidney cell suspensions and proved to be a fast, reliable, automated multiwell microplate assay to quantitate fish health status modulated by β-glucans.

  12. Effects of allergy and age on responses to salbutamol and ipratropium bromide in moderate asthma and chronic bronchitis.

    PubMed Central

    van Schayck, C P; Folgering, H; Harbers, H; Maas, K L; van Weel, C

    1991-01-01

    The bronchodilating responses to 400 micrograms salbutamol and 80 micrograms ipratropium bromide were studied in 188 patients with chronic bronchitis (n = 113) or asthma (n = 75) and mild to moderate airflow obstruction (forced expiratory volume in one second (FEV1) above 50% but below 2 SD of predicted value) in a crossover study on two days a week apart. Both the patients with asthma and the patients with chronic bronchitis varied considerably in their responses to the salbutamol and the ipratropium bromide. The mean increase in FEV1 in the subjects with asthma was higher after salbutamol (0.371 or 18% of the prebronchodilator value) than after ipratropium bromide (0.26 1 or 13%). In chronic bronchitis there was no difference between the increase in FEV1 after salbutamol (0.161 or 7%) and after ipratropium bromide (0.191 or 8%). When patients were categorised into those with a better response to salbutamol 400 micrograms and those with a better response to ipratropium bromide 80 micrograms, patients with chronic bronchitis responded better in general to ipratropium bromide whereas asthmatic patients responded better to salbutamol. The response pattern was also related to allergy and age, allergic patients and patients under 60 being more likely to respond better to salbutamol 400 micrograms than non-allergic patients and older patients, who benefited more from ipratropium bromide 80 micrograms. The response pattern was not related to sex, smoking habits, lung function, bronchial reactivity, respiratory symptoms, or number of exacerbations during the preceding year. PMID:1829865

  13. Severe Illness from Methyl Bromide Exposure at a Condominium Resort--U.S. Virgin Islands, March 2015.

    PubMed

    Kulkarni, Prathit A; Duncan, Mary Anne; Watters, Michelle T; Graziano, Leah T; Vaouli, Elena; Cseh, Larry F; Risher, John F; Orr, Maureen F; Hunte-Ceasar, Tai C; Ellis, Esther M

    2015-07-24

    On March 22, 2015, the Agency for Toxic Substances and Disease Registry (ATSDR) was notified by the U.S. Environmental Protection Agency (EPA) of four cases of suspected acute methyl bromide toxicity among family members vacationing at a condominium resort in the U.S. Virgin Islands. Methyl bromide is a pesticide that has been banned in the United States for use in homes and other residential settings. An investigation conducted by the U.S. Virgin Islands Department of Health (VIDOH), the U.S. Virgin Islands Department of Planning and Natural Resources (DPNR), and EPA confirmed that methyl bromide had been used as a fumigant on March 18 in the building where the family had been residing, 2 days before they were transported to the hospital; three family members had life-threatening illness. On March 25, 2015, a stop-use order for methyl bromide was issued by DPNR to the pest control company that had performed the fumigation. Subsequent investigation revealed that previous fumigation with methyl bromide had occurred on October 20, 2014, at the same condominium resort. In addition to the four ill family members, 37 persons who might have been exposed to methyl bromide as a result of the October 2014 or March 2015 fumigations were identified by VIDOH and ATSDR. Standardized health questionnaires were administered to 16 of the 20 persons for whom contact information was available; six of 16 had symptoms consistent with methyl bromide exposure, including headache and fatigue. Pest control companies should be aware that use of methyl bromide is banned in homes and other residential settings, and clinicians should be aware of the toxicologic syndrome that exposure to methyl bromide can cause.

  14. Synthesis of polyhydroxylated pyrrolidines from sugar-derived bromonitriles through a cascade addition of allylmagnesium bromide/cyclization/reduction.

    PubMed

    Malik, Michał; Jarosz, Sławomir

    2016-02-01

    The synthesis of polyhydroxylated 2-allylpyrrolidines from sugar-derived bromonitriles in a cascade addition of allylmagnesium bromide/SN2 cyclization/reduction with Zn(BH4)2 is described. The stereochemical course of the reduction step is rationalized. Two of the obtained compounds are transformed into stereoisomers of naturally-occurring iminosugar (+)-lentiginosine. In an alternative approach, 2,2-diallylpyrrolidines are obtained from bromonitriles in a cascade addition of allylmagnesium bromide/SN2 cyclization/addition of another equivalent of allylmagnesium bromide.

  15. Ba11La4Br34: a new barium lanthanum bromide

    PubMed Central

    Eagleman, Yetta; Wu, Guang; Gundiah, Gautam; Bourret-Courchesne, Edith; Derenzo, Stephen

    2011-01-01

    The structure of the title compound, barium lanthanum bromide (11/4/34), can be derived from the fluorite structure. The asymmetric unit contains two Ba sites (one with site symmetry 4/m..), one La site (site symmetry 4..), one mixed-occupied Ba and La site (ratio 1:1, site symmetry m..) and six Br sites (one with site symmetry \\=4.., one with 2.., one with m.., the latter being disordered over two positions with a 0.86:0.14 ratio). The fundamental building units of the structure are edge-sharing polyhedral clusters made up of Ba and La bromide clusters inter­connected to BaBr8 square prisms and BaBr10 groups. PMID:22064368

  16. Effect of pinaverium bromide on jejunal motility and colonic transit time in healthy humans.

    PubMed

    Bouchoucha, M; Salles, J P; Fallet, M; Frileux, P; Cugnenc, P H; Barbier, J P

    1992-01-01

    Pinaverium bromide is a specific calcium channel blocker used in the treatment of irritable bowel syndrome (IBS) for its spasmolytic activity. The aim of the present study was to evaluate the effect of orally administered pinaverium bromide on jejunal motility and total and segmental colonic transit time in control subjects. Gastrointestinal studies were performed in 10 healthy volunteers (30 +/- 3 years), before and after a treatment phase of 14 days (150 mg/d). Jejunal motility was measured by prolonged manometry (14 h) and colonic transit time by a multiple ingestion, single marker technique. No significant modification of phase III of the migrating motor complexes was demonstrated. On the contrary, a significant (p < 0.01) but weak decrease of the frequency of contraction was found. Unlike previous studies, no decrease of total or segmental colonic transit time was demonstrated. PMID:1421047

  17. Atmospheric methyl bromide (CH{sub 3}Br) from agricultural soil fumigations

    SciTech Connect

    Yagi, K.; Williams, J.; Wang, N.Y.; Cicerone, R.J.

    1995-03-31

    The treatment of agricultural soils with CH{sub 3}Br (MeBr) has been suggested to be a significant source of atmospheric MeBr which is involved in stratospheric ozone loss. A field fumigation experiment showed that, after 7 days, 34 percent of the applied MeBr had escaped into the atmosphere. The remaining 66 percent should have caused an increase in bromide in the soil; soil bromide increased by an amount equal to 70 percent of the applied MeBr, consistent with the flux measurements to within 4 percent. Comparison with an earlier experiment in which the escape of MeBr to the atmosphere was greater showed that higher soil pH, organic content and soil moisture, and deeper, more uniform injection of MeBr may in combination reduce the escape of MeBr. 17 refs., 3 figs., 1 tab.

  18. Atmospheric chemistry of toxic contaminants 4. Saturated halogenated aliphatics: Methyl bromide, epichlorhydrin, phosgene

    SciTech Connect

    Grosjean, D. )

    1991-01-01

    Mechanisms are outlined for the reactions that contribute to in-situ formation and atmospheric removal of the saturated halogenated aliphatic contaminants methyl bromide, epichlorhydrin, and phosgene. In-situ formation is important only for phosgene and involves the reaction of OH with chloroethenes and other chlorinated hydrocarbons. A ranking of these phosgene precursors is given using data for precursor ambient concentrations and chemical reactivity. The three toxic compounds studied are long-lived in the atmosphere, where removal of phosgene and methyl bromide by chemical reactions is negligibly slow. Epichlorhydrin is removed slowly by reaction with OH, leading to formaldehyde, chloroacetaldehyde, and the chlorinated peroxyacyl nitrate CH{sub 2}ClC(O)OONO{sub 2}.

  19. Intermolecular Photocatalyzed Heck-like Coupling of Unactivated Alkyl Bromides by a Dinuclear Gold Complex.

    PubMed

    Xie, Jin; Li, Jian; Weingand, Vanessa; Rudolph, Matthias; Hashmi, A Stephen K

    2016-08-26

    A practical protocol for a photocatalyzed alkyl-Heck-like reaction of unactivated alkyl bromides and different alkenes promoted by dinuclear gold photoredox catalysis in the presence of an inorganic base is reported. Primary, secondary, and tertiary unactivated alkyl bromides with β-hydrogen can be applied. Esters, aldehydes, ketones, nitriles, alcohols, heterocycles, alkynes, alkenes, ethers, and halogen moieties are all well tolerated. In addition to 1,1-diarylalkenes, silylenolethers and enamides can also be applied, which further increases the synthetic potential of the reaction. The mild reaction conditions, broad substrate scope, and an excellent functional-group tolerance deliver an ideal tool for synthetic chemists that can even be used for challenging late-stage modifications of complex natural products.

  20. A novel model-based approach for dose determination of glycopyrronium bromide in COPD

    PubMed Central

    2012-01-01

    Background Glycopyrronium bromide (NVA237) is an inhaled long-acting muscarinic antagonist in development for treatment of COPD. This study compared the efficacy and safety of once-daily (OD) and twice-daily (BID) glycopyrronium bromide regimens, using a novel model-based approach, in patients with moderate-to-severe COPD. Methods Double-blind, randomized, dose-finding trial with an eight-treatment, two-period, balanced incomplete block design. Patients (smoking history ≥10 pack-years, post-bronchodilator FEV1 ≥30% and <80% predicted, FEV1/FVC <0.7) were randomized to one of 16 independent sequences for 28 days. Primary endpoint: mean trough FEV1 at Day 28. Results 385 patients (mean age 61.2 years; mean post-bronchodilator FEV1 53% predicted) were randomized; 88.6% completed. All OD and BID dosing regimens produced dose-dependent bronchodilation; at Day 28, increases in mean trough FEV1 versus placebo were statistically significant for all regimens, ranging from 51 mL (glycopyrronium bromide 12.5 μg OD) to 160 mL (glycopyrronium bromide 50 μg BID). Pharmacodynamic steady-state was reached by Day 7. There was a small separation (≤37 mL) between BID and OD dose–response curves for mean trough FEV1 at steady-state in favour of BID dosing. Over 24 hours, separation between OD and BID regimens was even smaller (FEV1 AUC0-24h maximum difference for equivalent daily dose regimens: 8 mL). Dose–response results for FEV1 at 12 hours, FEV1 AUC0-12h and FEV1 AUC0-4h at steady-state showed OD regimens provided greater improvement over placebo than BID regimens for total daily doses of 25 μg, 50 μg and 100 μg, while the reverse was true for OD versus BID regimens from 12–24 hours. The 12.5 μg BID dose produced a marginally higher improvement in trough FEV1 versus placebo than 50 μg OD, however, the response at 12 hours over placebo was suboptimal (74 mL). Glycopyrronium bromide was safe and well tolerated at all doses

  1. Visible Light-Induced Photoredox Construction of Trifluoromethylated Quaternary Carbon Centers from Trifluoromethylated Tertiary Bromides.

    PubMed

    Huan, Feng; Chen, Qing-Yun; Guo, Yong

    2016-08-19

    A mild, operationally simple, visible light-induced photoredox method for constructing novel trifluoromethylated quaternary carbon centers from trifluoromethylated tertiary bromides has been developed. Using this method, a wide range of alkenes were successfully bifunctionalized to γ-butyrolactams. As for electron-rich alkenes, reactions catalyzed by Ir(dF(CF3)ppy)2(dtbbpy)(PF6) were kinetic processes with high yields and short times. For styrenes, reactions catalyzed by Ir(ppy)2(dtbbpy)(PF6) were thermodynamic processes with moderate yields and prolonged reaction times. For aliphatic alkenes, the reactions were neither thermodynamic nor kinetic and fac-Ir(ppy)3 was used as catalyst. Thus, reactions were not as efficient as electron-rich alkenes. The atom-transfer radical addition reactions of trifluoromethylated tertiary bromides with alkynes were also achieved. The configuration of products we separated was E type only. Some of the products exhibited bactericidal activity.

  2. Maintaining Flatness of a Large Aperture Potassium Bromide Beamsplitter Through Mounting and Vibration

    NASA Technical Reports Server (NTRS)

    Losch, Patricia; Lyons, James J., III; Morell, Armando; Heaney, Jim

    1998-01-01

    The Composite Infrared Spectrometer (CIRS) instrument on the Cassini Mission launched in October of 1997. The CIRS instrument contains a mid-infrared (MIR) and a far-infrared interferometer (FIR) and operates at 170 Kelvin. The MIR is a Michelson Fourier transform spectrometer utilizing a 76 mm (3 inch) diameter potassium bromide beamsplitter and compensator pair. The potassium bromide elements were tested to verify effects of cooldown and vibration prior to integration into the instrument. The instrument was then aligned at ambient temperatures, tested cryogenically and re-verified after vibration. 'Me stringent design optical figure requirements for the beamsplitter and compensator included fabrication errors, mounting stresses and vibration load effects. This paper describes the challenges encountered in mounting the elements to minimize distortion and to survive vibration.

  3. Maintaining Flatness of a Large Aperture Potassium Bromide Beamsplitter through Mounting and Vibration

    NASA Technical Reports Server (NTRS)

    Losch, Patricia; Lyons, James, III; Morell, Armando; Heaney, Jim

    1998-01-01

    The Composite Infrared Spectrometer (CIRS) instrument on the Cassini Mission launched in October of 1997. The CIRS instrument contains a mid-infrared and a far-infrared interferometer and operates at 170 Kelvin. The mid-infrared interferometer is a Michelson- type Fourier transform spectrometer utilizing a 3 inch diameter potassium bromide beamsplitter/compensator pair. The potassium bromide elements were tested to verify effects of cooldown and vibration prior to integration into the instrument. The instrument was then aligned at ambient temperatures, tested cryogenically and re-verified after vibration. The stringent design optical figure requirements for the beamsplitter and compensator included fabrication errors, mounting stresses and vibration load effects. This paper describes the challenges encountered in mounting the elements to minimize distortion and to survive vibration.

  4. Visible Light-Induced Photoredox Construction of Trifluoromethylated Quaternary Carbon Centers from Trifluoromethylated Tertiary Bromides.

    PubMed

    Huan, Feng; Chen, Qing-Yun; Guo, Yong

    2016-08-19

    A mild, operationally simple, visible light-induced photoredox method for constructing novel trifluoromethylated quaternary carbon centers from trifluoromethylated tertiary bromides has been developed. Using this method, a wide range of alkenes were successfully bifunctionalized to γ-butyrolactams. As for electron-rich alkenes, reactions catalyzed by Ir(dF(CF3)ppy)2(dtbbpy)(PF6) were kinetic processes with high yields and short times. For styrenes, reactions catalyzed by Ir(ppy)2(dtbbpy)(PF6) were thermodynamic processes with moderate yields and prolonged reaction times. For aliphatic alkenes, the reactions were neither thermodynamic nor kinetic and fac-Ir(ppy)3 was used as catalyst. Thus, reactions were not as efficient as electron-rich alkenes. The atom-transfer radical addition reactions of trifluoromethylated tertiary bromides with alkynes were also achieved. The configuration of products we separated was E type only. Some of the products exhibited bactericidal activity. PMID:27438228

  5. Synthesis and properties of PDMS/montmorillonite-cetyltrimethylammonium bromide-heparin films.

    PubMed

    Na Meng; Zhou, Ning-Lin

    2014-05-25

    In this study, poly(dimethylsiloxane)(PDMS)/montmorillonite-cetyltrimethylammonium bromide-heparin (PDMS/MMT-CTAB-HEP) films were prepared by solution intercalation technique. The cetyltrimethylammonium bromide-heparin (CTAB-HEP) was intercalated into montmorillonite (MMT) layers forming MMT-CTAB-HEP (modified MMT). The structure and properties of the film were characterized by XRD, TG and SEM. The modified MMT was homogeneously dispersed within the PDMS matrix. The effect of modified MMT on mechanical properties of the film was also investigated. As the modified MMT content was lower than 2wt%, the films showed excellent mechanical properties. The blood compatibility of PDMS/MMT-CTAB-HEP films was further evaluated by hemolysis test and platelet adhesion. Both hemolysis and platelet adhesions tests showed that PDMS/MMT-CTAB-HEP film had better blood compatibility than pure PDMS. PMID:24708954

  6. Role of pinaverium bromide in south Indian patients with irritable bowel syndrome.

    PubMed

    Jayanthi, V; Malathi, S; Ramathilakam, B; Dinakaran, N; Balasubramanian, V; Mathew, S

    1998-04-01

    The effect of pinaverium bromide in controlling gastrointestinal symptoms in 61 patients with irritable bowel syndrome was studied, as an open trial. Individually, there was significant relief in abdominal discomfort/pain as well as in bowel symptoms in most of the patients. Abdominal pain was reduced in 49%, stool consistency improved in 74%, straining and urgency decreased in 71% and mucus decreased in 64%. Tolerance to the drug administered was good and side-effects reported were few. PMID:11273320

  7. Reactions of ground-state and electronically excited sodium atoms with methyl bromide and molecular chlorine

    SciTech Connect

    Weiss, P.S.; Mestdagh, J.M.; Schmidt, H.; Covinsky, M.H.; Lee, Y.T. )

    1991-04-18

    The reactions of ground- and excited-state Na atoms with methyl bromide (CH{sub 3}Br) and chlorine (Cl{sub 2}) have been studied by using the crossed molecular beams method. For both reactions, the cross sections increase with increasing electronic energy. The product recoil energies change little with increasing Na electronic energy, implying that the product internal energies increase substantially. For Na + CH{sub 3}Br, the steric angle of acceptance opens with increasing electronic energy.

  8. Observation of micelle solution of decyltrimethylammonium bromide by electrospray ionization mass spectrometry.

    PubMed

    Nohara, D; Bitoh, M

    2000-12-01

    A micelle solution of decyltrimethylammonium bromide (DTAB) was analyzed by electrospray ionization mass spectrometry. Finding an appropriate range of a capillary-skimmer potential was a prerequisite for obtaining a satisfactory spectrum. The mean molecular weight of DTAB aggregates, 10,500, was deduced from a series of mass spectra acquired at different capillary-skimmer potentials. The value was comparable with the micelle weight, previously determined by the light-scattering method.

  9. Copper(I)-catalyzed aryl bromides to form intermolecular and intramolecular carbon-oxygen bonds.

    PubMed

    Niu, Jiajia; Guo, Pengran; Kang, Juntao; Li, Zhigang; Xu, Jingwei; Hu, Shaojing

    2009-07-17

    A highly efficient Cu-catalyzed C-O bond-forming reaction of alcohol and aryl bromides has been developed. This transformation was realized through the use of copper(I) iodide as a catalyst, 8-hydroxyquinoline as a ligand, and K(3)PO(4) as a base. A variety of functionalized substrates were found to react under these reaction conditions to provide products in good to excellent yields.

  10. Anharmonic force fields from analytic second derivatives: Method and application to methyl bromide

    NASA Astrophysics Data System (ADS)

    Schneider, Winfried; Thiel, Walter

    1989-05-01

    An efficient finite difference procedure is described for calculating anharmonic normal-coordinate force constants from quantum-chemical analytic second derivatives. Displacements along normal coordinates are used to generate those cubic and quartic force constants which are needed in a second-order perturbation treatment of anharmonicity. The anharmonic force field of methyl bromide is predicted, and the calculated spectroscopic constants compared with experimental data.

  11. Mechanism of HERG potassium channel inhibition by tetra-n-octylammonium bromide and benzethonium chloride

    SciTech Connect

    Long, Yan; Lin, Zuoxian; Xia, Menghang; Zheng, Wei; Li, Zhiyuan

    2013-03-01

    Tetra-n-octylammonium bromide and benzethonium chloride are synthetic quaternary ammonium salts that are widely used in hospitals and industries for the disinfection and surface treatment and as the preservative agent. Recently, the activities of HERG channel inhibition by these compounds have been found to have potential risks to induce the long QT syndrome and cardiac arrhythmia, although the mechanism of action is still elusive. This study was conducted to investigate the mechanism of HERG channel inhibition by these compounds by using whole-cell patch clamp experiments in a CHO cell line stably expressing HERG channels. Tetra-n-octylammonium bromide and benzethonium chloride exhibited concentration-dependent inhibitions of HERG channel currents with IC{sub 50} values of 4 nM and 17 nM, respectively, which were also voltage-dependent and use-dependent. Both compounds shifted the channel activation I–V curves in a hyperpolarized direction for 10–15 mV and accelerated channel activation and inactivation processes by 2-fold. In addition, tetra-n-octylammonium bromide shifted the inactivation I–V curve in a hyperpolarized direction for 24.4 mV and slowed the rate of channel deactivation by 2-fold, whereas benzethonium chloride did not. The results indicate that tetra-n-octylammonium bromide and benzethonium chloride are open-channel blockers that inhibit HERG channels in the voltage-dependent, use-dependent and state-dependent manners. - Highlights: ► Tetra-n-octylammonium and benzethonium are potent HERG channel inhibitors. ► Channel activation and inactivation processes are accelerated by the two compounds. ► Both compounds are the open-channel blockers to HERG channels. ► HERG channel inhibition by both compounds is use-, voltage- and state dependent. ► The in vivo risk of QT prolongation needs to be studied for the two compounds.

  12. Uses of chloride/bromide ratios in studies of potable water

    USGS Publications Warehouse

    Davis, S.N.; Whittemore, D.O.; Fabryka-Martin, J.

    1998-01-01

    In natural ground water systems, both chlorine and bromine occur primarily as monovalent anions, chloride and bromide. Although dissolution or precipitation of halite, biological activity in the root zone, anion sorption, and exchange can affect chloride/bromide ratios in some settings, movement of the ions in potable ground water is most often conservative. Atmospheric precipitation will generally have mass ratios between 50 and 150; shallow ground water, between 100 and 200; domestic sewage, between 300 and 600; water affected by dissolution of halite, between 1000 and 10,000; and summer runoff from urban streets, between 10 and 100. These, and other distinctive elemental ratios, are useful in the reconstruction of the origin and movement of ground water, as illustrated by case studies investigating sources of salinity in ground water from Alberta, Kansas, and Arizona, and infiltration rates and pathways at Yucca Mountain, Nevada.In natural ground water systems, both chlorine and bromine occur primarily as monovalent anions, chloride and bromide. Although dissolution or precipitation of halite, biological activity in the root zone, anion sorption, and exchange can affect chloride/bromide ratios in some settings, movement of the ions in potable ground water is most often conservative. Atmospheric precipitation will generally have mass ratios between 50 and 150; shallow ground water, between 100 and 200; domestic sewage, between 300 and 600; water affected by dissolution of halite, between 1000 and 10,000; and summer runoff from urban streets, between 10 and 100. These, and other distinctive elemental ratios, are useful in the reconstruction of the origin and movement of ground water; as illustrated by case studies investigating sources of salinity in ground water from Alberta, Kansas, and Arizona, and infiltration rates and pathways at Yucca Mountain, Nevada.

  13. Laboratory Evaluation of Drop-in Solvent Alternatives to n-Propyl Bromide for Vapor Degreasing

    NASA Technical Reports Server (NTRS)

    Mitchell, Mark A.; Lowrey, Nikki M.

    2012-01-01

    Based on this limited laboratory study, solvent blends of trans-1,2 dichloroethylene with HFEs, HFCs, or PFCs appear to be viable alternatives to n-propyl bromide for vapor degreasing. The lower boiling points of these blends may lead to greater solvent loss during use. Additional factors must be considered when selecting a solvent substitute, including stability over time, VOC, GWP, toxicity, and business considerations.

  14. Effect of Cetyltrimethylammonium Bromide (CTAB) on the Growth Rate and Morphology of Borax Crystals

    NASA Astrophysics Data System (ADS)

    Suharso; Parkinson, Gordon; Ogden, Mark

    An investigation of the effect of cetyltrimethylammonium bromide (CTAB) on both growth rate and morphology of borax crystal has been carried out. This experiment was carried out at temperature of 25°C and relative supersaturation of 0.21 and 0.74 under in situ cell optical microscopy method. The result shows that CTAB inhibits the growth rate and changes the morphology of borax crystal.

  15. Effects of oral pinaverium bromide on colonic response to food in irritable bowel syndrome patients.

    PubMed

    Bouchoucha, M; Faye, A; Devroede, G; Arsac, M

    2000-08-01

    We have recently developed a simple method to investigate the colonic response to food (CRF). This study describes the modifications of CRF induced by treatment with oral pinaverium bromide in irritable bowel syndrome (IBS) patients. Thirty healthy subjects and 43 patients suffering from IBS were studied. Colonic transit time (CTT) was measured in fasting conditions and after eating a standard test meal. Colonic response to food was quantified by calculating the variation in number of markers in each zone of interest of the large bowel between the X-ray films of the abdomen taken before and after eating. CRF is characterized by caudal propulsion of colonic contents in the two groups. In controls, there is emptying of the caecum-ascending colon region and filling of the rectosigmoid. In IBS patients, only the left transverse colon and the splenic flexure empty. Pinaverium bromide exerts no effect in controls but reverses the CRF of the right colon in IBS patients by inhibiting right colon emptying. These results suggest that the inhibitory action of pinaverium bromide on CRF may support the clinical efficacy of this calcium channel blocker in the treatment of IBS. PMID:10989977

  16. Inhibition of the colonic motor response to eating by pinaverium bromide in irritable bowel syndrome patients.

    PubMed

    Fioramonti, J; Frexinos, J; Staumont, G; Bueno, L

    1988-01-01

    The effect of pinaverium bromide on the colonic motor response to eating was investigated in 10 irritable bowel syndrome patients, by means of an intraluminal probe supporting 8 groups of electrodes. At each site examined from transverse to sigmoid colon, the electromyograms exhibited 2 kinds of spike bursts: short spike bursts (SSB) localized at one electrode, and long spike bursts (LSB), isolated, propagated orally or aborally over a few centimeters, or aborally propagated over the whole length of the colon investigated (migrating long spike bursts, MLSB). Recordings were continuously performed over 24 hr. Each patient received at 7.00 p.m. on day 1 and at noon on day 2 an 800-1000 Kcal meal preceded by IV administration of pinaverium bromide (4 mg) or placebo. After placebo administration, the duration of LSB activity and the number of MLSB were significantly increased over 3 postprandial hr by comparison with the 2 hr preceding the meal. After pinaverium injection no significant postprandial change in LSB and MLSB activity was noted. The SSB activity was not modified after the meals preceded by placebo or pinaverium injection. These results suggest that the inhibitory action of pinaverium bromide on postprandial colonic motility may support the clinical efficacy of this agent in the treatment of the irritable bowel syndrome. PMID:3371838

  17. Granular Activated Carbon Treatment May Result in Higher Predicted Genotoxicity in the Presence of Bromide.

    PubMed

    Krasner, Stuart W; Lee, Tiffany Chih Fen; Westerhoff, Paul; Fischer, Natalia; Hanigan, David; Karanfil, Tanju; Beita-Sandí, Wilson; Taylor-Edmonds, Liz; Andrews, Robert C

    2016-09-01

    Certain unregulated disinfection byproducts (DBPs) are more of a health concern than regulated DBPs. Brominated species are typically more cytotoxic and genotoxic than their chlorinated analogs. The impact of granular activated carbon (GAC) on controlling the formation of regulated and selected unregulated DBPs following chlorine disinfection was evaluated. The predicted cyto- and genotoxicity of DBPs was calculated using published potencies based on the comet assay for Chinese hamster ovary cells (assesses the level of DNA strand breaks). Additionally, genotoxicity was measured using the SOS-Chromotest (detects DNA-damaging agents). The class sum concentrations of trihalomethanes, haloacetic acids, and unregulated DBPs, and the SOS genotoxicity followed the breakthrough of dissolved organic carbon (DOC), however the formation of brominated species did not. The bromide/DOC ratio was higher than the influent through much of the breakthrough curve (GAC does not remove bromide), which resulted in elevated brominated DBP concentrations in the effluent. Based on the potency of the haloacetonitriles and halonitromethanes, these nitrogen-containing DBPs were the driving agents of the predicted genotoxicity. GAC treatment of drinking or reclaimed waters with appreciable levels of bromide and dissolved organic nitrogen may not control the formation of unregulated DBPs with higher genotoxicity potencies. PMID:27467860

  18. The suppression of opposed-jet methane-air flames by methyl bromide

    SciTech Connect

    Miller, E.; McMillion, L.G. )

    1992-04-01

    This paper reports on an opposed-jet diffusion flame burner that was used in conjunction with an emission infrared spectrometer to study the effects of the addition of methyl bromide on the combustion of methane with air. An optical system permitted incremental scanning of a laminar diffusion flame formed between two horizontally opposed burner tubes. The image of the flat flame was focused on an auxiliary slit of the spectrometer by optical mirrors and scanned by moving the slit passed the image. For a methane-air flame with an overall stoichiometric ratio, {phi}, of 0.86, the spectra for the 3700-2400 cm{sup {minus}1} region (H{sub 2}O, OH, CO{sub 2}, CH{sub 3}, and HCHO bands) and 2400 to 2000 cm{sup {minus}1} (CO and CO{sub 2} bands) were compared with the spectra obtained when methyl bromide was added to the air-side of the burner. Supplementary measurements were made on methane-air and methane-oxygen-nitrogen flames with {phi} values in the range of 0.74 - 2.0. In some cases, the methane was diluted with nitrogen, and the methyl bromide was added to either the fuel or the air side of the burner.

  19. Determination of methyl bromide in air resulting from pre-plant fumigations of plowed fields

    SciTech Connect

    Woodrow, J.E.; Honaganahalli, P.; Seiber, J.N.

    1995-12-31

    A method for measuring residues of methyl bromide in air entails concentrating the fumigant on charcoal from an airstream at a flowrate of 100 ml/min, desorption of the trapped material with benzyl alcohol solvent in a sealed vial at 60-110{degrees}C for 10-15 min, and then sampling of the equilibrated vapor for gas chromatographic assay using electron-capture detection. The desorbed vapor is chromatographed on a 27 in x 0.32 mm (id) porous-layer open tubular column, on which methyl bromide has a retention time of about 6 min at 90{degrees}C and at a carrier gas flowrate of 3-3.5 ml/min. Using this method, standard curves were linear over at least three orders of magnitude and a practical limit of detection for field air was about 20 ng/m{sup 3} ({approximately}5 ppt). This method has been used in studies concerned with methyl bromide volatilization from fumigated fields and with ambient background levels.

  20. Toxic impact of bromide and iodide on drinking water disinfected with chlorine or chloramines.

    PubMed

    Yang, Yang; Komaki, Yukako; Kimura, Susana Y; Hu, Hong-Ying; Wagner, Elizabeth D; Mariñas, Benito J; Plewa, Michael J

    2014-10-21

    Disinfectants inactivate pathogens in source water; however, they also react with organic matter and bromide/iodide to form disinfection byproducts (DBPs). Although only a few DBP classes have been systematically analyzed for toxicity, iodinated and brominated DBPs tend to be the most toxic. The objectives of this research were (1) to determine if monochloramine (NH2Cl) disinfection generated drinking water with less toxicity than water disinfected with free chlorine (HOCl) and (2) to determine the impact of added bromide and iodide in conjunction with HOCl or NH2Cl disinfection on mammalian cell cytotoxicity and genomic DNA damage induction. Water disinfected with chlorine was less cytotoxic but more genotoxic than water disinfected with chloramine. For both disinfectants, the addition of Br(-) and I(-) increased cytotoxicity and genotoxicity with a greater response observed with NH2Cl disinfection. Both cytotoxicity and genotoxicity were highly correlated with TOBr and TOI. However, toxicity was weakly and inversely correlated with TOCl. Thus, the forcing agents for cytotoxicity and genotoxicity were the generation of brominated and iodinated DBPs rather than the formation of chlorinated DBPs. Disinfection practices need careful consideration especially when using source waters containing elevated bromide and iodide.

  1. A Systematic Study on the Mesomorphic Behavior of Asymmetrical 1-Alkyl-3-dodecylimidazolium Bromides

    SciTech Connect

    Yang, Mei; Mallick, Bert; Mudring, Anja-Verena

    2014-04-02

    To determine the essential parameters for mesophase formation in imidazolium-based ionic liquids (ILs), a library of 1-alkyl-3-dodecylimidazolium bromides was synthesized, abbreviated as CnC12, where 0 ≤ n ≤ 13, as the general notion is that a dodecyl side chain would guarantee the formation of an ionic liquid crystal (ILC). All salts were fully characterized by NMR spectroscopy and mass spectrometry. Their thermal properties were recorded, and mesophase formation was assessed. An odd–even effect is observed for 5 ≤ n ≤ 10 in the temperatures of melting transitions. While the majority of this series, as expected, formed mesophases, surprisingly compounds C2C12 and C6C12 could not be classified as ILCs, the latter being a room temperature IL, while C2C12 is a crystalline solid with melting point at 37 °C. The single crystal structure of compound 1-ethyl-3-dodecylimidazolium bromide (C2C12) was successfully obtained. Remarkably, the arrangement of imidazolium cores in the structure is very complicated due to multiple nonclassical hydrogen bonds between bromide anions and imidazolium head groups. In this arrangement, neighboring imidazolium rings are forced by hydrogen bonds to form a “face-to-face” conformation. This seems to be responsible for the elimination of a mesophase. To conclude, the general view of a dodecyl chain being a functional group to generate a mesophase is not entirely valid.

  2. Room temperature synthesis of silver nanowires from tabular silver bromide crystals in the presence of gelatin

    SciTech Connect

    Liu Suwen; Wehmschulte, Rudolf J. . E-mail: rwehmsch@fit.edu; Lian Guoda; Burba, Christopher M.

    2006-03-15

    Long silver nanowires were synthesized at room temperature by a simple and fast process derived from the development of photographic films. A film consisting of an emulsion of tabular silver bromide grains in gelatin was treated with a photographic developer (4-(methylamino)phenol sulfate (metol), citric acid) in the presence of additional aqueous silver nitrate. The silver nanowires have lengths of more than 50 {mu}m, some even more than 100 {mu}m, and average diameters of about 80 nm. Approximately, 70% of the metallic silver formed in the reduction consists of silver nanowires. Selected area electron diffraction (SAED) results indicate that the silver nanowires grow along the [111] direction. It was found that the presence of gelatin, tabular silver bromide crystals and silver ions in solution are essential for the formation of the silver nanowires. The nanowires appear to originate from the edges of the silver bromide crystals. They were characterized by transmission electron microscopy (TEM), SAED, scanning electron microscopy (SEM), and powder X-ray diffraction (XRD)

  3. Leisingera methylohalidivorans gen. nov., sp. nov., a marine methylotroph that grows on methyl bromide

    USGS Publications Warehouse

    Schaefer, J.K.; Goodwin, K.D.; McDonald, I.R.; Murrell, J.C.; Oremland, R.S.

    2002-01-01

    A marine methylotroph, designated strain MB2T, was isolated for its ability to grow on methyl bromide as a sole carbon and energy source. Methyl chloride and methyl iodide also supported growth, as did methionine and glycine betaine. A limited amount of growth was observed with dimethyl sulfide. Growth was also noted with unidentified components of the complex media marine broth 2216, yeast extract and Casamino acids. No growth was observed on methylated amines, methanol, formate, acetate, glucose or a variety of other substrates. Growth on methyl bromide and methyl iodide resulted in their oxidation to CO2 with stoichiometric release of bromide and iodide, respectively. Strain MB2T exhibited growth optima at NaCl and Mg2+ concentrations similar to that of seawater. Phylogenetic analysis of the 16S rDNA sequence placed this strain in the ??-Proteobacteria in proximity to the genera Ruegeria and Roseobacter. It is proposed that strain MB2T (= ATCC BAA-92T = DSM 14336T) be designated Leisingera methylohalidivorans gen. nov., sp. nov.

  4. Hydration of alkylammonium salt micelles--influence of bromide and chloride counterions.

    PubMed

    Rózycka-Roszak, B; Zyłka, R; Sarapuk, J

    2000-01-01

    The micellization process of dodecyltrimethylammonium chloride (DTAC) and bromide (DTAB) was studied. Nuclear magnetic resonance method was used. The 1H NMR and 13C NMR spectra were taken at higher and lower concentrations than the critical micelle concentrations (CMC) of the compounds studied. Chemical shifts were analysed. The studies performed were prompted by earlier calorimetric measurements which showed that there were significant qualitative and quantitative differences in the micellization process of the compounds studied. Namely, DTAB micelle dissociation was found to be an endothermic process while that of DTAC was exothermic. The differences found must be the result of differentiated influence of bromide and chloride counterions on the micellization process, including the phenomenon of micelle hydration. The objective of the work was to check whether cationic surfactant counterions can influence the micelle hydration process. Indeed, DTAB and DTAC, as monomers, exhibit similar hydrophobic hydration, but DTAB micelles are more hydrated than DTAC ones. It seems that the differences found in micellization of both salts studied may be attributed to different physicochemical properties of bromide and chloride ions, such as their mobilities and radii of their hydrated forms. Moreover, the effect of anions on the water structure must be taken into account. It is important whether the anions can be classified as water ordering kosmotropes, that hold the first hydration shell tightly, or water disordering chaotropes, that hold water molecules in that shell loosely.

  5. Effects of oral pinaverium bromide on colonic response to food in irritable bowel syndrome patients.

    PubMed

    Bouchoucha, M; Faye, A; Devroede, G; Arsac, M

    2000-08-01

    We have recently developed a simple method to investigate the colonic response to food (CRF). This study describes the modifications of CRF induced by treatment with oral pinaverium bromide in irritable bowel syndrome (IBS) patients. Thirty healthy subjects and 43 patients suffering from IBS were studied. Colonic transit time (CTT) was measured in fasting conditions and after eating a standard test meal. Colonic response to food was quantified by calculating the variation in number of markers in each zone of interest of the large bowel between the X-ray films of the abdomen taken before and after eating. CRF is characterized by caudal propulsion of colonic contents in the two groups. In controls, there is emptying of the caecum-ascending colon region and filling of the rectosigmoid. In IBS patients, only the left transverse colon and the splenic flexure empty. Pinaverium bromide exerts no effect in controls but reverses the CRF of the right colon in IBS patients by inhibiting right colon emptying. These results suggest that the inhibitory action of pinaverium bromide on CRF may support the clinical efficacy of this calcium channel blocker in the treatment of IBS.

  6. Evaluation of the potential carcinogenicity of cadmium, cadium acetate, cadmium bromide, cadmium chloride. Final report

    SciTech Connect

    Not Available

    1988-06-01

    Cadmium is a probable human carcinogen, classified as weight-of-evidence Group B1 under the EPA Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986a). Evidence on potential carcinogenicity from animal studies is Sufficient, and the evidence from human studies is Limited. The potency factor (F) for cadmium is estimated to be 57.9/(mg/kg/day) (based on epidemiology data for cadmium workers), placing it in potency group 2 according to the CAG's methodology for evaluating potential carcinogens (U.S. EPA, 1986b). Cadmium weight of evidence and potency are based on epidemiology data for cadmium workers exposed to cadmium oxide and/or cadmium fume. Although human data for cadmium salts are lacking, due to the responsiveness of animals to soluble cadmium compounds, especially cadmium chloride, the weight of evidence and potency for cadmium acetate, cadmium bromide and cadmium chloride are considered to be the same as those cadmium compounds to which workers are exposed. Thus, cadmium acetate, cadmium bromide, and cadmium chloride are all classified as weight-of-evidence Group and the potency group, cadmium, cadmium acetate, cadmium bromide, and cadmium chloride are assigned MEDIUM hazard rankings for the purposes of RQ adjustment. Combining the weight-of-evidence group and the potency group, carbon tetrachloride is assigned a MEDIUM hazard ranking for the purposes of RQ adjustment.

  7. Improving food and agriculture productivity and the environment: Canadian initiatives in methyl bromide alternatives and emission control technologies. Revised edition

    SciTech Connect

    Marcotte, M.; Tibelius, C.

    1998-12-31

    Methyl bromide, a fumigant used in the agricultural sector, was listed as an ozone-depleting substance under the Montreal Protocol and is scheduled for phasing out in Canada. This report begins with a review of the joint industry/government approach being taken to plan and manage this phase-out. It then reviews alternative solutions that have been formulated and tested as replacements for the use of methyl bromide in greenhouse cultivation, soil fumigation, strawberry transplant production, tobacco production, grain production, and food processing facilities. Contact names and addresses are provided for those seeking further information. The final sections describe activities in methyl bromide recovery and recycling and list industry and government organizations that have expertise in methyl bromide alternatives.

  8. Detection of water contamination from hydraulic fracturing wastewater: a μPAD for bromide analysis in natural waters.

    PubMed

    Loh, Leslie J; Bandara, Gayan C; Weber, Genevieve L; Remcho, Vincent T

    2015-08-21

    Due to the rapid expansion in hydraulic fracturing (fracking), there is a need for robust, portable and specific water analysis techniques. Early detection of contamination is crucial for the prevention of lasting environmental damage. Bromide can potentially function as an early indicator of water contamination by fracking waste, because there is a high concentration of bromide ions in fracking wastewaters. To facilitate this, a microfluidic paper-based analytical device (μPAD) has been developed and optimized for the quantitative colorimetric detection of bromide in water using a smartphone. A paper microfluidic platform offers the advantages of inexpensive fabrication, elimination of unstable wet reagents, portability and high adaptability for widespread distribution. These features make this assay an attractive option for a new field test for on-site determination of bromide.

  9. The molecular structures, vibrational spectroscopies (FT-IR and Raman) and quantum chemical calculations of n-alkyltrimethylammonium bromides

    NASA Astrophysics Data System (ADS)

    Gökce, Halil; Bahçeli, Semiha

    2013-11-01

    The FT-IR and micro-Raman spectra of three n-alkyltrimethylammonium bromides (dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB) and hexadecyl(cetyl)trimethylammonium bromide (CTAB)) in powder form were recorded in the regions 4000-550 cm-1 and 3200-300 cm-1, respectively. The optimized geometries and vibrational frequencies of DTAB, TTAB and CTAB have been carried out with ab initio Hartree-Fock (HF) and density functional theory method B3LYP calculations with the 6-31 G (d, p) basis set in the ground state. The comparison of the observed fundamental vibrational frequencies and calculated results for the fundamental vibrational frequencies of DTAB, TTAB and CTAB indicate that the scaled B3LYP method is superior compared to the scaled HF method.

  10. Detection of water contamination from hydraulic fracturing wastewater: a μPAD for bromide analysis in natural waters.

    PubMed

    Loh, Leslie J; Bandara, Gayan C; Weber, Genevieve L; Remcho, Vincent T

    2015-08-21

    Due to the rapid expansion in hydraulic fracturing (fracking), there is a need for robust, portable and specific water analysis techniques. Early detection of contamination is crucial for the prevention of lasting environmental damage. Bromide can potentially function as an early indicator of water contamination by fracking waste, because there is a high concentration of bromide ions in fracking wastewaters. To facilitate this, a microfluidic paper-based analytical device (μPAD) has been developed and optimized for the quantitative colorimetric detection of bromide in water using a smartphone. A paper microfluidic platform offers the advantages of inexpensive fabrication, elimination of unstable wet reagents, portability and high adaptability for widespread distribution. These features make this assay an attractive option for a new field test for on-site determination of bromide. PMID:26161586

  11. Efficient ring-closing metathesis of alkenyl bromides: the importance of protecting the catalyst during the olefin approach.

    PubMed

    Gatti, Michele; Drinkel, Emma; Wu, Linglin; Pusterla, Ivano; Gaggia, Fiona; Dorta, Reto

    2010-11-01

    We present the first productive ring-closing metathesis reaction that leads to the construction of cyclic alkenyl bromides. Efficient catalysis employing commercially available Grubbs II catalyst is possible through appropriate modification of the starting bromoalkene moiety.

  12. Estimating Potential Increased Bladder Cancer Risk Due to Increased Bromide Concentrations in Sources of Disinfected Drinking Waters - slides

    EPA Science Inventory

    Public water systems are increasingly facing higher bromide levels in their source waters from anthropogenic contamination through coal-fired powerplants, conventional oil and gas extraction, and hydraulic fracturing. Climate change is likely to exacerbate this in coming years. W...

  13. Estimating Potential Increased Bladder Cancer Risk Due to Increased Bromide Concentrations in Sources of Disinfected Drinking Waters

    EPA Science Inventory

    Public water systems are increasingly facing higher bromide levels in their source waters from anthropogenic contamination through coal-fired power plants, conventional oil and gas extraction, and hydraulic fracturing. Climate change is likely to exacerbate this in coming years. ...

  14. Pharmacological characterization of the interaction between aclidinium bromide and formoterol fumarate on human isolated bronchi.

    PubMed

    Cazzola, Mario; Calzetta, Luigino; Page, Clive P; Rogliani, Paola; Facciolo, Francesco; Gavaldà, Amadeu; Matera, Maria Gabriella

    2014-12-15

    Long-acting muscarinic receptor antagonists (LAMAs) and long-acting β2-adrenoceptor agonists (LABAs) cause airway smooth muscle (ASM) relaxation via different signal transduction pathways, but there are limited data concerning the interaction between these two drug classes on human bronchi. The aim of this study was to investigate the potential synergistic interaction between aclidinium bromide and formoterol fumarate on the relaxation of human ASM. We evaluated the influence of aclidinium bromide and formoterol fumarate on the contractile response induced by acetylcholine or electrical field stimulation (EFS) on human isolated airways (segmental bronchi and bronchioles). We analyzed the potential synergistic interaction between the compounds when administered in combination by using Bliss independence (BI) theory. Both aclidinium bromide and formoterol fumarate completely relaxed segmental bronchi pre-contracted with acetylcholine (Emax: 97.5±2.6% and 96.4±1.1%; pEC50 8.5±0.1 and 8.8±0.1; respectively). Formoterol fumarate, but not aclidinium bromide, abolished the contraction induced by acetylcholine in bronchioles (Emax: 68.1±4.5% and 99.0±5.6%; pEC50 7.9±0.3 and 8.4±0.3; respectively). The BI analysis indicated synergistic interaction at low concentrations in segmental bronchi (+18.4±2.7%; P<0.05 versus expected effect) and from low to high concentrations in bronchioles (+19.7±0.9%; P<0.05 versus expected effect). Low concentrations of both drugs produced a synergistic relaxant interaction on isolated bronchi stimulated with EFS that was sustained for 6h post-treatment (+55.1±9.4%; P<0.05 versus expected effect). These results suggest that combining aclidinium bromide plus formoterol fumarate provides synergistic benefit on ASM relaxation of both medium and small human airways, which may have major implications for the use of this combination in the clinic.

  15. Pharmacological characterization of the interaction between aclidinium bromide and formoterol fumarate on human isolated bronchi.

    PubMed

    Cazzola, Mario; Calzetta, Luigino; Page, Clive P; Rogliani, Paola; Facciolo, Francesco; Gavaldà, Amadeu; Matera, Maria Gabriella

    2014-12-15

    Long-acting muscarinic receptor antagonists (LAMAs) and long-acting β2-adrenoceptor agonists (LABAs) cause airway smooth muscle (ASM) relaxation via different signal transduction pathways, but there are limited data concerning the interaction between these two drug classes on human bronchi. The aim of this study was to investigate the potential synergistic interaction between aclidinium bromide and formoterol fumarate on the relaxation of human ASM. We evaluated the influence of aclidinium bromide and formoterol fumarate on the contractile response induced by acetylcholine or electrical field stimulation (EFS) on human isolated airways (segmental bronchi and bronchioles). We analyzed the potential synergistic interaction between the compounds when administered in combination by using Bliss independence (BI) theory. Both aclidinium bromide and formoterol fumarate completely relaxed segmental bronchi pre-contracted with acetylcholine (Emax: 97.5±2.6% and 96.4±1.1%; pEC50 8.5±0.1 and 8.8±0.1; respectively). Formoterol fumarate, but not aclidinium bromide, abolished the contraction induced by acetylcholine in bronchioles (Emax: 68.1±4.5% and 99.0±5.6%; pEC50 7.9±0.3 and 8.4±0.3; respectively). The BI analysis indicated synergistic interaction at low concentrations in segmental bronchi (+18.4±2.7%; P<0.05 versus expected effect) and from low to high concentrations in bronchioles (+19.7±0.9%; P<0.05 versus expected effect). Low concentrations of both drugs produced a synergistic relaxant interaction on isolated bronchi stimulated with EFS that was sustained for 6h post-treatment (+55.1±9.4%; P<0.05 versus expected effect). These results suggest that combining aclidinium bromide plus formoterol fumarate provides synergistic benefit on ASM relaxation of both medium and small human airways, which may have major implications for the use of this combination in the clinic. PMID:25446566

  16. Bromide Sources and Loads in Swiss Surface Waters and Their Relevance for Bromate Formation during Wastewater Ozonation.

    PubMed

    Soltermann, Fabian; Abegglen, Christian; Götz, Christian; von Gunten, Urs

    2016-09-20

    Bromide measurements and mass balances in the catchments of major Swiss rivers revealed that chemical industry and municipal waste incinerators are the most important bromide sources and account for ∼50% and ∼20%, respectively, of the ∼2000 tons of bromide discharged in the Rhine river in 2014 in Switzerland. About 100 wastewater treatment plants (WWTPs) will upgrade their treatment for micropollutant abatement in the future to comply with Swiss regulations. An upgrade with ozonation may lead to unintended bromate formation in bromide-containing wastewaters. Measured bromide concentrations were <0.05 mg L(-1) in ∼75% of 69 WWTPs, while they ranged from 0.4 to ∼50 mg L(-1) in WWTPs with specific bromide sources (e.g., municipal waste incinerators, landfill leachate, and chemical industry). Wastewater ozonation formed little bromate at specific ozone doses of ≤0.4 mg O3/mg DOC, while the bromate yields were almost linearly correlated to the specific ozone dose for higher ozone doses. Molar bromate yields for typical specific ozone doses in wastewater treatment (0.4-0.6 mg O3/mg DOC) are ≤3%. In a modeled extreme scenario (in which all upgraded WWTPs release 10 μg L(-1) of bromate), bromate concentrations increased by <0.4 μg L(-1) in major Swiss rivers and by several micrograms per liter in receiving water bodies with a high fraction of municipal wastewater.

  17. Comparison of pinaverium bromide, manganese chloride and D600 effects on electrical and mechanical activities in rat uterine smooth muscle.

    PubMed

    Mironneau, J; Lalanne, C; Mironneau, C; Savineau, J P; Lavie, J L

    1984-02-10

    The effects of pinaverium bromide, were compared with those of D600 and manganese chloride (Mn), on membrane potentials, ionic currents and isometric contractions in uterine smooth muscle strips from pregnant rats. Pinaverium bromide (10(-7) - 10(-6) M) depressed twitch contractions and K-contractures within 15-20 min while D600 (2 X 10(-6) M) and Mn (10(-3) M) abolished both contractions. D600 and pinaverium bromide were more potent inhibitors in K-depolarized preparations than in polarized tissues. At a supramaximal dose (10(-5) M), pinaverium bromide decreased the rate of rise, amplitude, and rate of repolarization of the action potential, and prolonged the potential duration. The inward Ca current was depressed and the reduction in Cai was responsible for the decrease in K current. Pinaverium bromide (10(-5) M) depressed the myometrial contractions induced in Ca-free solution by acetylcholine (10(-4) M) and by prolonged membrane depolarizations. Mn (2.5 X 10(-3) M) only reduced the Ach-induced contraction and D600 (10(-5) M) had no effect on intracellular Ca stores. The results indicate that pinaverium bromide has Ca channel blocking properties similar to those of currently used Ca antagonists; it may also exert an effect to depress contractions supported by intracellular Ca release. PMID:6325214

  18. Bromide Sources and Loads in Swiss Surface Waters and Their Relevance for Bromate Formation during Wastewater Ozonation.

    PubMed

    Soltermann, Fabian; Abegglen, Christian; Götz, Christian; von Gunten, Urs

    2016-09-20

    Bromide measurements and mass balances in the catchments of major Swiss rivers revealed that chemical industry and municipal waste incinerators are the most important bromide sources and account for ∼50% and ∼20%, respectively, of the ∼2000 tons of bromide discharged in the Rhine river in 2014 in Switzerland. About 100 wastewater treatment plants (WWTPs) will upgrade their treatment for micropollutant abatement in the future to comply with Swiss regulations. An upgrade with ozonation may lead to unintended bromate formation in bromide-containing wastewaters. Measured bromide concentrations were <0.05 mg L(-1) in ∼75% of 69 WWTPs, while they ranged from 0.4 to ∼50 mg L(-1) in WWTPs with specific bromide sources (e.g., municipal waste incinerators, landfill leachate, and chemical industry). Wastewater ozonation formed little bromate at specific ozone doses of ≤0.4 mg O3/mg DOC, while the bromate yields were almost linearly correlated to the specific ozone dose for higher ozone doses. Molar bromate yields for typical specific ozone doses in wastewater treatment (0.4-0.6 mg O3/mg DOC) are ≤3%. In a modeled extreme scenario (in which all upgraded WWTPs release 10 μg L(-1) of bromate), bromate concentrations increased by <0.4 μg L(-1) in major Swiss rivers and by several micrograms per liter in receiving water bodies with a high fraction of municipal wastewater. PMID:27525579

  19. Alteration Behavior of High Burnup Spent Fuel in Salt Brine Under Hydrogen Overpressure and in Presence of Bromide

    SciTech Connect

    Loida, Andreas; Metz, Volker; Kienzler, Bernhard

    2007-07-01

    Recent studies have shown that in the presence of H2 overpressure, which forms due to the corrosion of the Fe based container, the dissolution rate of the spent fuel matrix is slowed down by a factor of about 10, associated with a distinct decrease of concentrations of important radionuclides. However, in a natural salt environment as well as in geological formations with chloride rich groundwater the presence of radiation chemically active impurities such as bromide must be taken in consideration. Bromide is known to react with {beta}/{gamma} radiolysis products, thus counteracting the protective H{sub 2} effect. In the present experiments using high burnup spent fuel, it is observed that during 212 days the matrix dissolution rate was enhanced by a factor of about 10 in the presence of up to 10{sup -3} M bromide and 3.2 bar H{sub 2} overpressure. However, concentrations of matrix bound actinides were found at the same level or below as found under identical conditions, but in the absence of bromide. In the long-term it is expected that the effect of bromide becomes less important, because the decrease of {beta}/{gamma}-activity results in a decrease of oxidative radicals, which react with bromide, while a-activity will dominate the radiation field. (authors)

  20. 1-Benzyl-2,5-diphenyl-3-tosylimidazol­idin-4-one

    PubMed Central

    Sakthimurugesan, K.; Ranjith, S.; SubbiahPandi, A.; Namitharan, K.; Pitchumani, K.

    2011-01-01

    In the title compound, C29H26N2O3S, the central imidazolidine ring adopts an envelope conformation with the N atom bearing the benzyl ring at the flap. The S atom has distorted tetra­hedral geometry. The benzyl and tosyl rings are oriented at a dihedral angle of 52.1 (1)°. The phenyl rings connected to the imidazolidine ring form a dihedral angle of 28.7 (1)°. PMID:22058970

  1. Examining the interrelationship between DOC, bromide and chlorine dose on DBP formation in drinking water--a case study.

    PubMed

    Bond, Tom; Huang, Jin; Graham, Nigel J D; Templeton, Michael R

    2014-02-01

    During drinking water treatment aqueous chlorine and bromine compete to react with natural organic matter (NOM). Among the products of these reactions are potentially harmful halogenated disinfection by-products, notably four trihalomethanes (THM4) and nine haloacetic acids (HAAs). Previous research has concentrated on the role of bromide in chlorination reactions under conditions of a given NOM type and/or concentration. In this study different concentrations of dissolved organic carbon (DOC) from U.K. lowland water were reacted with varying amounts of bromide and chlorine in order to examine the interrelationship between the three reactants in the formation of THM4, dihaloacetic acids (DHAAs) and trihaloacetic acids (THAAs). Results showed that, in general, molar yields of THM4 increased with DOC, bromide and chlorine concentrations, although yields did fluctuate versus chlorine dose. In contrast both DHAA and THAA yields were mainly independent of changes in bromide and chlorine dose at low DOC (1 mg·L(-1)), but increased with chlorine dose at higher DOC concentrations (4 mg·L(-1)). Bromine substitution factors reached maxima of 0.80, 0.67 and 0.65 for the THM4, DHAAs and THAAs, respectively, at the highest bromide/chlorine ratio studied. These results suggest that THM4 formation kinetics depend on both oxidation and halogenation steps, whereas for DHAAs and THAAs oxidation steps are more important. Furthermore, they indicate that high bromide waters may prove more problematic for water utilities with respect to THM4 formation than for THAAs or DHAAs. While mass concentrations of all three groups increased in response to increased bromide incorporation, only the THMs also showed an increase in molar yield. Overall, the formation behaviour of DHAA and THAA was more similar than that of THM4 and THAA.

  2. Aerodynamic measurements of methyl bromide volatilization from tarped and nontarped fields

    USGS Publications Warehouse

    Majewski, M.S.; McChesney, M.M.; Woodrow, J.E.; Prueger, J.H.; Seiber, J.N.

    1995-01-01

    Methyl bromide (MeBr) is used extensively in agriculture as a soil fumigant and there is growing concern over the role it may play in the depletion of stratospheric ozone. Methyl bromide is applied using various techniques and very little is known about how much of the applied fumigant volatilizes into the atmosphere after the application. This held study was designed to estimate the post-application methyl bromide volatilization loss rates from two different application practices. The fields were approximately 6 km apart in Monterey County, California, and were treated in conformity with local practices as of 1992. The MeBr was injected at a depth of 25 to 30 cm. One field was covered simultaneously with a high-barrier plastic film tarp during the application, and the other was left uncovered, but the furrows made by the injection shanks were bedded over. Volatilization fluxes were estimated using an aerodynamic-gradient technique immediately following the completion of the application process and continued for 9 d for the tarped held and 6 d for the nontarped field. The cumulative volatilization losses from the tarped field were 22% of the nominal application within the first 5 d of the experiment and about 32% of the nominal application within 9 d including the one day after the tarp was removed on Day 8 after application. In contrast, the nontarped field lost 89% of the nominal application by volatilization in 5 d. The volatilization rate from the tarped field was shown to he significantly lower than the nontarped field at a 95% confidence level.

  3. Aerodynamic measurements of methyl bromide volatilization from tarped and nontarped fields

    SciTech Connect

    Majewski, M.S.; McChesney, M.M.; Woodrow, J.E.; Seiber, J.N.

    1995-07-01

    Methyl bromide (MeBr) is used extensively in agriculture as a soil fumigant and there is growing concern over the role it may play in the depletion of stratospheric ozone. Methyl bromide is applied using various techniques and very little is known about how much of the applied fumigant volatilizes into the atmosphere after the application. This field study was designed to estimate the post-application methyl bromide volatilization loss rates from two different application practices. The fields were approximately 6 km apart in Monterey County, California, and were treated in conformity with local practices as of 1992. The MeBr was injected at a depth of 25 to 30 cm. One field was covered simultaneously with a high-barrier plastic film tarp during the application, and the other was left uncovered, but the furrows made by the injection shanks were bedded over. Volatilization fluxes were estimated using an aerodynamic-gradient technique immediately following the completion of the application process and continued for 9 d for the tarped field and 6 d for the nontarped field. The cumulative volatilization losses from the tarped field were 22% of the nominal application within the first 5 d of the experiment and about 32% of the nominal application within 9 d including the one day after the tarp was removed on Day 8 after application. In contrast, the nontarped field lost 89% of the nominal application by volatilization in 5 d. The volatilization rate from the tarped field was shown to be significantly lower than the nontarped field at a 95% confidence level. 43 refs., 5 figs., 3 tabs.

  4. Measurement and computation of movement of bromide ions and carbofuran in ridged humic-sandy soil.

    PubMed

    Leistra, Minze; Boesten, Jos J T I

    2010-07-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. Rainfall was supplemented by sprinkler irrigation. The distribution of the substances in the soil profile of the ridges and furrows was measured on three dates in the potato growing season. Separate ridge and furrow systems were simulated by using the pesticide emission assessment at regional and local scales (PEARL) model for pesticide behavior in soil-plant systems. The substances travelled deeper in the furrow soil than in the ridge soil, because of runoff from the ridges to the furrows. At 19 days after application, the peak of the bromide distribution was measured to be in the 0.1-0.2 m layer of the ridges, while it was in the 0.3-0.5 m layer of the furrows. After 65 days, the peak of the carbofuran distribution in the ridge soil was still in the 0.1 m top layer, while the pesticide was rather evenly distributed in the top 0.6 m of the furrow soil. The wide ranges in concentration measured with depth showed that preferential water flow and substance transport occurred in the sandy soil. Part of the bromide ion distribution was measured to move faster in soil than the computed wave. The runoff of water and pesticide from the ridges to the furrows, and the thinner root zone in the furrows, are expected to increase the risk of leaching to groundwater in ridged fields, in comparison with more level fields.

  5. Bromide oxidation by ferrate(VI): The formation of active bromine and bromate.

    PubMed

    Jiang, Yanjun; Goodwill, Joseph E; Tobiason, John E; Reckhow, David A

    2016-06-01

    Ferrate (VI) (abbreviated as Fe(VI)) has long been considered as a green oxidant that does not produce any known hazardous byproducts. However, this work shows that Fe(VI) can slowly oxidize bromide forming active bromine (HOBr/OBr(-)) and bromate, and in natural waters total organic bromine (TOBr) can also be detected. Results showed that the highest levels of active bromine and bromate were formed at lower pHs and in the absence of phosphate. Hydrogen peroxide, which forms from the reaction of Fe(VI) and water, plays an essential role in suppressing bromate formation by reducing active bromine back to bromide. Fe(VI) decomposition products (assumed to be particulate phase Fe(III)) can catalyze the decomposition of hydrogen peroxide by Fe(VI). Phosphate had a substantial inhibiting effect on the formation of active bromine, but less so on bromate formation. The presence of the raw water matrix in natural water suppressed bromate formation. For a natural water spiked with 0.1 mg/L of bromide, the bromate and TOBr concentrations after Fe(VI) oxidation were below 3.0 and 15 μg/L, respectively. No consistent trend regarding the effect of pH or buffer ions on TOBr formation was observed due to the competition between Fe(VI), hydrogen peroxide, and natural organic matter (NOM) for reaction with active bromine. Under environmentally relevant conditions, the formation of bromate and TOBr would not be a problem for Fe(VI) application as their concentration levels are quite low.

  6. Measurement and computation of movement of bromide ions and carbofuran in ridged humic-sandy soil.

    PubMed

    Leistra, Minze; Boesten, Jos J T I

    2010-07-01

    Water flow and pesticide transport in the soil of fields with ridges and furrows may be more complex than in the soil of more level fields. Prior to crop emergence, the tracer bromide ion and the insecticide carbofuran were sprayed on the humic-sandy soil of a potato field with ridges and furrows. Rainfall was supplemented by sprinkler irrigation. The distribution of the substances in the soil profile of the ridges and furrows was measured on three dates in the potato growing season. Separate ridge and furrow systems were simulated by using the pesticide emission assessment at regional and local scales (PEARL) model for pesticide behavior in soil-plant systems. The substances travelled deeper in the furrow soil than in the ridge soil, because of runoff from the ridges to the furrows. At 19 days after application, the peak of the bromide distribution was measured to be in the 0.1-0.2 m layer of the ridges, while it was in the 0.3-0.5 m layer of the furrows. After 65 days, the peak of the carbofuran distribution in the ridge soil was still in the 0.1 m top layer, while the pesticide was rather evenly distributed in the top 0.6 m of the furrow soil. The wide ranges in concentration measured with depth showed that preferential water flow and substance transport occurred in the sandy soil. Part of the bromide ion distribution was measured to move faster in soil than the computed wave. The runoff of water and pesticide from the ridges to the furrows, and the thinner root zone in the furrows, are expected to increase the risk of leaching to groundwater in ridged fields, in comparison with more level fields. PMID:20041324

  7. Evaluation of bromide mass discharge in a sandy aquifer at Vandenberg AFB, CA

    NASA Astrophysics Data System (ADS)

    Mackay, D. M.; Rasa, E.; Einarson, M.; Kaiser, P.; Chakraborty, I.; Scow, K. M.

    2009-12-01

    Side-by-side experiments were conducted by UC Davis research team at a former fuel station at Vandenberg Air Force Base (AFB) to evaluate the rate of transformation of methyl tert-butyl ether (MTBE) to tert-butyl alcohol (TBA) impacted by ethanol and to investigate evidence of TBA degradation under sulfate reducing conditions. On one side we injected groundwater amended with ethanol and MTBE. In the other lane we injected groundwater amended with TBA. On both sides, injected ground water was spiked with bromide tracer to provide estimates of groundwater flow direction variations, flow velocity, dispersion, and mobile mass loss resulting from diffusive sequestration into aquitards. 162 monitoring wells were aligned into seven transects located downgradient of the injection wells. The mass discharge approach was used to evaluate the natural attenuation of the injected constituents. In this talk we will focus on calculations of mass discharge of the bromide tracer at each of the seven monitoring well transects. The amount of bromide mass discharged through each transect was calculated for any sampling time using field measurements of break through curves. Cumulative mass discharges were estimated and, by iteration based on mass balance, the flow properties of the aquifer were estimated. The calibration process resulted in subtle but quantitatively important changes in our assumptions regarding key physical properties of the aquifer (thickness, porosity) which could be only approximately estimated by standard methods (coring, CPT, etc.). On the basis of this calibration, a more robust approach was devised for evaluating the source and fate of TBA in the aquifer.

  8. Effects of Pressure, Temperature, and Concentration on the Viscosity of Aqueous Ammonium Bromide Solution

    NASA Astrophysics Data System (ADS)

    Yoshimura, Yukihiro; Sawamura, Seiji; Taniguchi, Yoshihiro

    1995-03-01

    The viscosity of aqueous ammonium bromide solutions is measured at 0.1-1.0 mol kg-1, 278.2-323.2 K, and 0.1-375 MPa, using a high-pressure rolling-ball viscometer. The activation energy (Ev) for viscous flow and Jones-Dole's B coefficient are estimated. Ev against pressure yields a concave curve with a minimum and B yields a convex one with a maximum. These phenomena are attributed to pressure, temperature, and concentration effects on the water-structure.

  9. Nitrate ion photolysis in thin water films in the presence of bromide ions.

    PubMed

    Richards, Nicole K; Wingen, Lisa M; Callahan, Karen M; Nishino, Noriko; Kleinman, Michael T; Tobias, Douglas J; Finlayson-Pitts, Barbara J

    2011-06-16

    Nitrate ions commonly coexist with halide ions in aged sea salt particles, as well as in the Arctic snowpack, where NO(3)(-) photochemistry is believed to be an important source of NO(y) (NO + NO(2) + HONO + ...). The effects of bromide ions on nitrate ion photochemistry were investigated at 298 ± 2 K in air using 311 nm photolysis lamps. Reactions were carried out using NaBr/NaNO(3) and KBr/KNO(3) deposited on the walls of a Teflon chamber. Gas phase halogen products and NO(2) were measured as a function of photolysis time using long path FTIR, NO(y) chemiluminescence and atmospheric pressure ionization mass spectrometry (API-MS). Irradiated NaBr/NaNO(3) mixtures show an enhancement in the rates of production of NO(2) and Br(2) as the bromide mole fraction (χ(NaBr)) increased. However, this was not the case for KBr/KNO(3) mixtures where the rates of production of NO(2) and Br(2) remained constant over all values of χ(KBr). Molecular dynamics (MD) simulations show that the presence of bromide in the NaBr solutions pulls sodium toward the solution surface, which in turn attracts nitrate to the interfacial region, allowing for more efficient escape of NO(2) than in the absence of halides. However, in the case of KBr/KNO(3), bromide ions do not appreciably affect the distribution of nitrate ions at the interface. Clustering of Br(-) with NO(3)(-) and H(2)O predicted by MD simulations for sodium salts may facilitate a direct intermolecular reaction, which could also contribute to higher rates of NO(2) production. Enhanced photochemistry in the presence of halide ions may be important for oxides of nitrogen production in field studies such as in polar snowpacks where the use of quantum yields from laboratory studies in the absence of halide ions would lead to a significant underestimate of the photolysis rates of nitrate ions.

  10. General method for the preparation of active esters by palladium-catalyzed alkoxycarbonylation of aryl bromides.

    PubMed

    de Almeida, Angelina M; Andersen, Thomas L; Lindhardt, Anders T; de Almeida, Mauro V; Skrydstrup, Troels

    2015-02-01

    A useful method was developed for the synthesis of active esters by palladium-catalyzed alkoxycarbonylation of (hetero)aromatic bromides. The protocol was general for a range of oxygen nucleophiles including N-hydroxysuccinimide (NHS), pentafluorophenol (PFP), hexafluoroisopropyl alcohol (HFP), 4-nitrophenol, and N-hydroxyphthalimide. A high functional group tolerance was displayed, and several active esters were prepared with good to excellent isolated yields. The protocol was extended to access an important synthetic precursor to the HIV-protease inhibitor, saquinavir, by formation of an NHS ester followed by acyl substitution.

  11. Copper-Catalyzed Annulation: A Method for the Systematic Synthesis of Phenanthridinium Bromide.

    PubMed

    Jhang, Yuan-Ye; Fan-Chiang, Tai-Ting; Huang, Jun-Min; Hsieh, Jen-Chieh

    2016-03-01

    A novel procedure for the Cu-catalyzed systematic synthesis of phenanthridinium bromide is reported. This transformation was achieved with direct construction of central pyridinium core by using an in situ formed biaryl imine as a substrate. Tolerance of a very wide variety of N-substituents is indicated; this has never previously been disclosed by other reports. Application of this method to synthesis of the natural alkaloid bicolorine, and its derivatives, was also carried out in only three synthetic steps from commercially available compounds. PMID:26883677

  12. A New, More Stable Polymorphic Form of Otilonium Bromide: Solubility, Crystal Structure, and Phase Transformation.

    PubMed

    Vega, Daniel R; Halac, Emilia; Segovia, Luciano; Baggio, Ricardo

    2016-10-01

    A new polymorphic form of otilonium bromide is presented (Form I), and a thorough analysis of its crystal and molecular structure is performed. The compound suffers a temperature-driven first-order phase transition at about 396 K, which transforms it into the polymorph reported by Dapporto P and Sega A (Acta Cryst. 1986;C42:474-478) (Form II). Through thermal analysis and solubility experiments the relative stability of both crystal modifications were determined, confirming that at room temperature this new Form I is the more stable one, Form II existing just in a metastable state. PMID:27444388

  13. Generation, spectroscopy, and structure of cyanoformyl chloride and cyanoformyl bromide, XC(O)CN.

    PubMed

    Pasinszki, Tibor; Vass, Gábor; Klapstein, Dieter; Westwood, Nicholas P C

    2012-04-01

    Cyanoformyl chloride and cyanoformyl bromide, XC(O)CN (X = Cl and Br), have been investigated in the gas phase by UV photoelectron and mid-infrared spectroscopies. The ground-state geometries of the neutral molecules have been obtained from quantum-chemical calculations at the B3LYP and CCSD(T) levels using the aug-cc-pVTZ basis set. The individual spectroscopies provide a detailed investigation into the vibrational and electronic character of the molecules and are supported by quantum-chemical calculations. The results are compared to data for structurally and chemically related molecules.

  14. A simple model for calculating the performance of a lithium-bromide/water coil absorber

    SciTech Connect

    Seewald, J.S.; Perez-Blanco, H.

    1994-12-31

    The performance of an absorber is of paramount importance when considering the overall performance of an absorption-cycle heat pump. Thus, a thorough understanding of the absorption process and a means of predicting the performance of an absorber are useful. For these reasons, a model of the absorption process in a simple absorber, using lithium-bromide and water as the working fluids, was developed. Subsequently, the model was applied to a particular absorber through the use of a computer program. Using this program, the effect on absorber performance due to the variance of several parameters was analyzed. The results of the absorber performance simulations are also presented.

  15. Fabrication of concave and convex potassium bromide lens arrays by compression molding.

    PubMed

    de la Barrière, Florence; Druart, Guillaume; Guèrineau, Nicolas; Taboury, Jean; Gueugnot, Alain; Huc, Vincent

    2012-07-20

    A new simple and cost-effective method has been developed for the fabrication of both plano-convex and plano-concave lens arrays with potentially important sag heights. The process is based on the use of potassium bromide (KBr) powder. At ambient temperature and under pressure, KBr powder is compressed on a molding die with the desired shape to form a solid lens array. The quality of the lens arrays has been assessed, and we present the first image produced by a converging KBr lens array.

  16. Highly stable, luminescent core-shell type methylammonium-octylammonium lead bromide layered perovskite nanoparticles.

    PubMed

    Bhaumik, Saikat; Veldhuis, Sjoerd A; Ng, Yan Fong; Li, Mingjie; Muduli, Subas Kumar; Sum, Tze Chien; Damodaran, Bahulayan; Mhaisalkar, Subodh; Mathews, Nripan

    2016-06-01

    A new protocol for the synthesis of a highly stable (over 2 months under ambient conditions) solution-processed core-shell type structure of mixed methylammonium-octylammonium lead bromide perovskite nanoparticles (5-12 nm), having spherical shape, color tunability in the blue to green spectral region (438-521 nm) and a high photoluminescence quantum yield (PLQY) of up to 92% is described. The color tunability, high PLQY and stability are due to the quantum confinement imparted by the crystal engineering associated with core-shell nanoparticle formation during growth. PMID:27165565

  17. Copper(I) Bromide: An Alternative Emitter for Blue-Colored Flame Pyrotechnics.

    PubMed

    Juknelevicius, Dominykas; Karvinen, Eero; Klapötke, Thomas M; Kubilius, Rytis; Ramanavicius, Arunas; Rusan, Magdalena

    2015-10-19

    Copper(I) bromide was evaluated as an alternative emitter for blue flame pyrotechnic compositions. CuBr and CuCl emission spectra were recorded from a butane torch flame and compared. Cu(BrO3 )2 was synthesized and used in pyrotechnic compositions as an oxidizer and the source for the generation of CuBr species. Pyrotechnic compositions, which contained copper and potassium bromates as oxidizers, were optimized for the generation of blue flames. The experimental data, including emission spectra of the flames, chromaticity coordinates, burning rates, luminous intensities, and sensitivity tests, were analyzed and compared. PMID:26471445

  18. Synthesis of Allenamides by Copper-Catalyzed Coupling of Propargylic Bromides and Nitrogen Nucleophiles.

    PubMed

    Demmer, Charles S; Benoit, Emeline; Evano, Gwilherm

    2016-03-18

    An efficient and general synthesis of allenamides derived from oxazolidinones and hydantoins is reported. Upon activation with a combination of a copper catalyst and a 2,2'-bipyridine derivative in the presence of an inorganic base, propargylic bromides were found to be suitable reagents for the direct allenylation of nitrogen nucleophiles by a formal copper-catalyzed S(N)2' reaction. Besides the availability of the starting materials, notable features of this route to allenamides are its mild reaction conditions, the reaction being performed at room temperature in most cases, and its applicability to the preparation of mono-, di-, as well as trisubstituted allenamides. PMID:26936415

  19. A New, More Stable Polymorphic Form of Otilonium Bromide: Solubility, Crystal Structure, and Phase Transformation.

    PubMed

    Vega, Daniel R; Halac, Emilia; Segovia, Luciano; Baggio, Ricardo

    2016-10-01

    A new polymorphic form of otilonium bromide is presented (Form I), and a thorough analysis of its crystal and molecular structure is performed. The compound suffers a temperature-driven first-order phase transition at about 396 K, which transforms it into the polymorph reported by Dapporto P and Sega A (Acta Cryst. 1986;C42:474-478) (Form II). Through thermal analysis and solubility experiments the relative stability of both crystal modifications were determined, confirming that at room temperature this new Form I is the more stable one, Form II existing just in a metastable state.

  20. Temperature dependence of chloride, bromide, iodide, thiocyanate and salicylate transport in human red cells

    PubMed Central

    Dalmark, Mads; Wieth, Jens Otto

    1972-01-01

    1. The temperature dependence of the steady-state self-exchange of chloride between human red cells and a plasma-like electrolyte medium has been studied by measuring the rate of 36Cl- efflux from radioactively labelled cells. Between 0 and 10° C the rate increased by a factor of eight corresponding to an Arrhenius activation energy of 33 kcal/mole. 2. The rate of chloride exchange decreased significantly in experiments where 95% of the chloride ions in cells and medium were replaced by other monovalent anions of a lyotropic series. The rate of chloride self-exchange was increasingly reduced by bromide, bicarbonate, nitrate, iodide, thiocyanate, and salicylate. The latter aromatic anion was by far the most potent inhibitor, reducing the rate of chloride self-exchange to 0·2% of the value found in a chloride medium. 3. The temperature sensitivity of the chloride self-exchange was not affected significantly by the anionic inhibitors. The Arrhenius activation energies of chloride exchange were between 30 and 40 kcal/mole in the presence of the six inhibitory anions mentioned above. 4. The rate of self-exchange of bromide, thiocyanate, and iodide between human red cells and media was determined after washing and labelling cells in media containing 120 mM bromide, thiocyanate, or iodide respectively. The rate of self-exchange of the three anions were 12, 3, and 0·4% of the rate of chloride self-exchange found in the chloride medium. 5. The Arrhenius activation energies of the self-exchange of bromide, iodide, and thiocyanate were all between 29 and 37 kcal/mole, the same magnitude as found for the self-exchange of chloride. 6. Although approximately 40% of the intracellular iodide and salicylate ions appeared to be adsorbed to intracellular proteins, the rate of tracer anion efflux followed first order kinetics until at least 98% of the intracellular anions had been exchanged. 7. The self-exchange of salicylate across the human red cell membrane occurred by a

  1. Supported nickel bromide catalyst for atom transfer radical polymerization (ATRP) of methyl methacrylate.

    PubMed

    Duquesne, E; Degée, Ph; Habimana, J; Dubois, Ph

    2004-03-21

    A new supported catalytic system, i.e. nickel bromide catalyst ligated by triphenylphosphine (TPP) ligands immobilized onto crosslinked polystyrene resins (PS-TPP) is reported. Per se, this catalyst does not allow any control over the polymerization of methyl methacrylate (MMA) initiated by ethyl 2-bromoisobutyrate but, in the presence of a given amount of purposely added free TPP, it promotes controlled ATRP of MMA. Indeed colorless PMMA chains of low polydispersity indices are readily recovered, the molecular weight of which linearly increases with monomer conversion and agrees with the expected values. Recycling of the supported catalyst is evidenced and does not prevent the polymerization from being controlled. PMID:15010758

  2. Copper(I) Bromide: An Alternative Emitter for Blue-Colored Flame Pyrotechnics.

    PubMed

    Juknelevicius, Dominykas; Karvinen, Eero; Klapötke, Thomas M; Kubilius, Rytis; Ramanavicius, Arunas; Rusan, Magdalena

    2015-10-19

    Copper(I) bromide was evaluated as an alternative emitter for blue flame pyrotechnic compositions. CuBr and CuCl emission spectra were recorded from a butane torch flame and compared. Cu(BrO3 )2 was synthesized and used in pyrotechnic compositions as an oxidizer and the source for the generation of CuBr species. Pyrotechnic compositions, which contained copper and potassium bromates as oxidizers, were optimized for the generation of blue flames. The experimental data, including emission spectra of the flames, chromaticity coordinates, burning rates, luminous intensities, and sensitivity tests, were analyzed and compared.

  3. Studies on the interaction of fluorescein isothiocyanate and its sugar analogues with cetyltrimethylammonium bromide

    NASA Astrophysics Data System (ADS)

    Ghosh, Sujit Kumar; Ali, Mohammed; Chatterjee, Hirak

    2013-03-01

    The interaction of fluorescein isothiocyanate (FITC) and its two sugar analogues (viz., FITC-Dextran 40S and FITC-Dextran 2000S) with cetyltrimethylammonium bromide has been elucidated by absorption, fluorescence, Fourier transform infrared spectroscopy and fluorescence microscopic studies. It is seen that the emission of the probe molecules is uniquely sensitive to the changes in surfactant concentrations at a particular regime due to the formation of dye-surfactant supramolecular assembly. The formation of supramolecular assembly becomes effective at a lower surfactant concentration with increasing dextran size as a consequence of definite dye-surfactant interaction and could pave a facile strategy for designing hierarchical superstructures.

  4. Water vapor resistance of plasma-polymerized coatings on potassium bromide windows

    NASA Technical Reports Server (NTRS)

    Wydeven, T.; Johnson, C. C.

    1981-01-01

    Plasma-polymerized tetrafluoroethylene (PPTFE) coated potassium bromide IR window are shown to possess better resistance to moisture than either ethylene or chlorotrifluoroethylene. The PPTFE-coated windows tolerated an upper limit relative humidity of about 80% at 297 K, without visible damage to either window or coating, over a period of 24 hours. Elemental analysis of the bulk, and photoelectron spectroscopy of the coating surface, showed that PPTFE coatings deposited downstream of the internal plasma reactor electrodes contained less atmospheric oxygen than coatings deposited between the electrodes; perhaps accounting for the improved moisture resistance.

  5. Estimating Potential Increased Bladder Cancer Risk Due to Increased Bromide Concentrations in Sources of Disinfected Drinking Waters.

    PubMed

    Regli, Stig; Chen, Jimmy; Messner, Michael; Elovitz, Michael S; Letkiewicz, Frank J; Pegram, Rex A; Pepping, T J; Richardson, Susan D; Wright, J Michael

    2015-11-17

    Public water systems are increasingly facing higher bromide levels in their source waters from anthropogenic contamination through coal-fired power plants, conventional oil and gas extraction, textile mills, and hydraulic fracturing. Climate change is likely to exacerbate this in coming years. We estimate bladder cancer risk from potential increased bromide levels in source waters of disinfecting public drinking water systems in the United States. Bladder cancer is the health end point used by the United States Environmental Protection Agency (EPA) in its benefits analysis for regulating disinfection byproducts in drinking water. We use estimated increases in the mass of the four regulated trihalomethanes (THM4) concentrations (due to increased bromide incorporation) as the surrogate disinfection byproduct (DBP) occurrence metric for informing potential bladder cancer risk. We estimate potential increased excess lifetime bladder cancer risk as a function of increased source water bromide levels. Results based on data from 201 drinking water treatment plants indicate that a bromide increase of 50 μg/L could result in a potential increase of between 10(-3) and 10(-4) excess lifetime bladder cancer risk in populations served by roughly 90% of these plants. PMID:26489011

  6. Estimating Potential Increased Bladder Cancer Risk Due to Increased Bromide Concentrations in Sources of Disinfected Drinking Waters.

    PubMed

    Regli, Stig; Chen, Jimmy; Messner, Michael; Elovitz, Michael S; Letkiewicz, Frank J; Pegram, Rex A; Pepping, T J; Richardson, Susan D; Wright, J Michael

    2015-11-17

    Public water systems are increasingly facing higher bromide levels in their source waters from anthropogenic contamination through coal-fired power plants, conventional oil and gas extraction, textile mills, and hydraulic fracturing. Climate change is likely to exacerbate this in coming years. We estimate bladder cancer risk from potential increased bromide levels in source waters of disinfecting public drinking water systems in the United States. Bladder cancer is the health end point used by the United States Environmental Protection Agency (EPA) in its benefits analysis for regulating disinfection byproducts in drinking water. We use estimated increases in the mass of the four regulated trihalomethanes (THM4) concentrations (due to increased bromide incorporation) as the surrogate disinfection byproduct (DBP) occurrence metric for informing potential bladder cancer risk. We estimate potential increased excess lifetime bladder cancer risk as a function of increased source water bromide levels. Results based on data from 201 drinking water treatment plants indicate that a bromide increase of 50 μg/L could result in a potential increase of between 10(-3) and 10(-4) excess lifetime bladder cancer risk in populations served by roughly 90% of these plants.

  7. Modeling Water Flow and Bromide Transport in a Two-Scale-Structured Lignitic Mine Soil

    NASA Astrophysics Data System (ADS)

    Dusek, J.; Gerke, H. H.; Vogel, T.; Maurer, T.; Buczko, U.

    2008-12-01

    Two-dimensional single- and dual-permeability simulations are used to analyze water and solute fluxes in heterogeneous lignitic mine soil at a forest-reclaimed mine spoil heap. The soil heterogeneity on this experimental site "Barenbrucker Hohe" resulted from inclined dumping structures and sediment mixtures that consist of sand with lignitic dust and embedded lignitic fragments. Observations on undisturbed field suction- cell lysimeters including tracer experiments revealed funneling-type preferential flow with lateral water and bromide movement along inclined sediment structures. The spatial distribution of soil structures and fragment distributions was acquired by a digital camera and identified by a supervised classification of the digital profile image. First, a classical single-domain modeling approach was proposed with spatially variable scaling factors inferred from image analyses. In the next step, a two-continuum scenario was constructed to examine additional effects of nonequilibrium on the flow regime. The scaling factors used for the preferential flow domain are here obtained from the gradient of the grayscale images. So far, the single domain scenarios failed to predict the bromide leaching patterns although water effluent could be described. Dual-permeability model allows the incorporation of structural effects and can be used as a tool to further testing other approaches that account for structure effects. The numerical study suggests that additional experiments are required to obtain better understanding of the highly complex transport processes on this experimental site.

  8. Acute hepatitis after starting pinaverium bromide in a patient taking mirtazapine.

    PubMed

    Tak, Sandeep; Tak, Shubhanjali

    2014-01-01

    A 56-year-old man presented with chronic abdominal pain. He had been evaluated extensively in the recent past undergoing upper gastrointestinal endoscopy, colonoscopy and CT scan of the abdomen with normal results. The provisional diagnosis of irritable bowel syndrome was performed and pinaverium bromide was started. The patient had pre-existing hypertension, a major depressive disorder and gastro-oesophageal reflux disease. He had been taking nebivolol and pantoprazole for several years and mirtazapine for the last 1 year. The patient developed nausea, vomiting and anorexia after 5 days of starting pinaverium bromide. Investigations revealed marked elevation of liver enzymes and bilirubin. He was negative for HIV, HBSAg, anti-hepatitis C virus, IgM for hepatitis A virus, hepatitis E virus, antinuclear antibody and antimitochondrial antibody. An ultrasound showed mild hepatomegaly with hypoechoic echo texture; the rest of scan was normal. Pinaverium and mirtazapine were stopped immediately. The patient was treated symptomatically and his liver profile returned to normal after 4 weeks. PMID:25015163

  9. Acute hepatitis after starting pinaverium bromide in a patient taking mirtazapine

    PubMed Central

    Tak, Sandeep; Tak, Shubhanjali

    2014-01-01

    A 56-year-old man presented with chronic abdominal pain. He had been evaluated extensively in the recent past undergoing upper gastrointestinal endoscopy, colonoscopy and CT scan of the abdomen with normal results. The provisional diagnosis of irritable bowel syndrome was performed and pinaverium bromide was started. The patient had pre-existing hypertension, a major depressive disorder and gastro-oesophageal reflux disease. He had been taking nebivolol and pantoprazole for several years and mirtazapine for the last 1 year. The patient developed nausea, vomiting and anorexia after 5 days of starting pinaverium bromide. Investigations revealed marked elevation of liver enzymes and bilirubin. He was negative for HIV, HBSAg, anti-hepatitis C virus, IgM for hepatitis A virus, hepatitis E virus, antinuclear antibody and antimitochondrial antibody. An ultrasound showed mild hepatomegaly with hypoechoic echo texture; the rest of scan was normal. Pinaverium and mirtazapine were stopped immediately. The patient was treated symptomatically and his liver profile returned to normal after 4 weeks. PMID:25015163

  10. Model prediction uncertainty of bromide and pesticides transport in laboratory column

    NASA Astrophysics Data System (ADS)

    Dusek, Jaromir; Dohnal, Michal; Snehota, Michal; Sobotkova, Martina; Ray, Chittaranjan; Vogel, Tomas

    2016-04-01

    Knowledge of transport parameters of reactive solutes such as pesticides is a prerequisite for reliable predictions of their fate and transport in soil porous systems. Water flow and transport of bromide tracer and five pesticides (atrazine, imazaquin, sulfometuron methyl, S-metolachlor, and imidacloprid) through an undisturbed soil column of tropical Oxisol were analyzed using a one-dimensional numerical model. Laboratory column leaching experiment with three flow interruptions was conducted. The applied numerical model is based on Richards' equation for solving water flow and the advection-dispersion equation for solving solute transport. A global optimization method was used to evaluate the model's sensitivity to transport parameters and the uncertainty of model predictions. Within the Monte Carlo modeling framework, multiple forward simulations searching through the parametric space, were executed to describe the observed breakthrough curves. All pesticides were found to be relatively mobile. Experimental data indicated significant non-conservative behavior of bromide tracer. All pesticides, with the exception of imidacloprid, were found less persistent. Three of the five pesticides (atrazine, sulfometuron methyl, and S-metolachlor) were better described by the linear kinetic sorption model, while the breakthrough curves of imazaquin and imidacloprid were more appropriately approximated using nonlinear instantaneous sorption. Sensitivity analysis suggested that the model is most sensitive to sorption distribution coefficient. The prediction limits contained most of the measured points of the experimental breakthrough curves, indicating adequate model concept and model structure for the description of transport processes in the soil column under study.

  11. Iodide, bromide, and ammonium in hydraulic fracturing and oil and gas wastewaters: environmental implications.

    PubMed

    Harkness, Jennifer S; Dwyer, Gary S; Warner, Nathaniel R; Parker, Kimberly M; Mitch, William A; Vengosh, Avner

    2015-02-01

    The expansion of unconventional shale gas and hydraulic fracturing has increased the volume of the oil and gas wastewater (OGW) generated in the U.S. Here we demonstrate that OGW from Marcellus and Fayetteville hydraulic fracturing flowback fluids and Appalachian conventional produced waters is characterized by high chloride, bromide, iodide (up to 56 mg/L), and ammonium (up to 420 mg/L). Br/Cl ratios were consistent for all Appalachian brines, which reflect an origin from a common parent brine, while the I/Cl and NH4/Cl ratios varied among brines from different geological formations, reflecting geogenic processes. There were no differences in halides and ammonium concentrations between OGW originating from hydraulic fracturing and conventional oil and gas operations. Analysis of discharged effluents from three brine treatment sites in Pennsylvania and a spill site in West Virginia show elevated levels of halides (iodide up to 28 mg/L) and ammonium (12 to 106 mg/L) that mimic the composition of OGW and mix conservatively in downstream surface waters. Bromide, iodide, and ammonium in surface waters can impact stream ecosystems and promote the formation of toxic brominated-, iodinated-, and nitrogen disinfection byproducts during chlorination at downstream drinking water treatment plants. Our findings indicate that discharge and accidental spills of OGW to waterways pose risks to both human health and the environment.

  12. Modelling of a Tracer experiment (Bromide) at the lysimeter Wagna/Austria with MIKE-SHE

    NASA Astrophysics Data System (ADS)

    Reszler, Christian; Fank, Johann

    2015-04-01

    Data of a tracer experiment with Bromide at one of the three lysimeters in Wagna/Austria are used to test the unsaturated zone solute transport model in MIKE-SHE. On April 4th, 2005 50 mg/l of Bromide were applied on the lysimeter operated with conventional farming. At this time the lysimeter was covered with bare soil until the start of the cultivation of pumpkin one month later. Concentrations at the lysimeter bottom (180 cm depth) were measured and, after break-through, plant uptake was measured to quantify mass recovery. The model using the Richards-Van Genuchten-Mualem approach is setup by comprehensive data of vegetation and soil hydraulic properties available at the lysimeter. Water movement simulation in the unsaturated zone is tested against measured seepage rates at the lysimeter bottom and soil water contents in different soil depths in a period of five years. A sensitivity study shows that, particularly in the quaternary gravel zone two different parameter sets are necessary to represent the different dynamics of water content and seepage. With both two sets the general dynamics of the tracer experiment are simulated well. However, the early rapid rise of the measured concentrations could not be represented by either parameter set, which indicates a complex pore system consisting of different flow paths in the gravel zone, e.g., a system of matrix flow and macro-pore flow.

  13. Pressure-Induced Structural and Optical Properties of Organometal Halide Perovskite-Based Formamidinium Lead Bromide.

    PubMed

    Wang, Lingrui; Wang, Kai; Zou, Bo

    2016-07-01

    Organometal halide perovskites (OMHPs) are attracting an ever-growing scientific interest as photovoltaic materials with moderate cost and compelling properties. In this Letter, pressure-induced optical and structural changes of OMHP-based formamidinium lead bromide (FAPbBr3) were systematically investigated. We studied the pressure dependence of optical absorption and photoluminescence, both of which showed piezochromism. Synchrotron X-ray diffraction indicated that FAPbBr3 underwent two phase transitions and subsequent amorphization, leading directly to the bandgap evolution with redshift followed by blueshift during compression. Raman experiments illustrated the high pressure behavior of organic cation and the surrounding inorganic octahedra. Additionally, the effect of cation size and the different intermolecular interactions between organic cation and inorganic octahedra result in the fact that FAPbBr3 is less compressible than the reported methylammonium lead bromide (MAPbBr3). High pressure studies of the structural evolution and optical properties of OMHPs provide important clues in optimizing photovoltaic performance and help to design novel OMHPs with higher stimuli-resistant ability. PMID:27321024

  14. Mechanism of denaturation of bovine serum albumin by dodecyl trimethylammonium bromide.

    PubMed

    Moosavi-Movahedi, A A; Bordbar, A K; Taleshi, A A; Naderimanesh, H M; Ghadam, P

    1996-09-01

    Bovine serum albumin (BSA) denaturation has been extensively studied by different anionic and cationic surfactant. Dodecyl trimethylammonium bromide (DTAB) is a cationic surfactant, and it is suggested that it binds to the C-terminal section of BSA. In the present study, the thermodynamical denaturation of BSA by dodecyl trimethylammonium bromide (DTAB) has been studied with various experimental techniques. Equilibrium dialysis, thermal denaturation, gel electrophoresis, titration microcalorimetry at pH 7, I = 0.005, and different temperatures were all performed. The enthalpy obtained from the van't Hoff relation and calorimetry method as well as electrophoresis results were utilized to explain the BSA tranistion state. Major findings included: the binding isotherm shifts at a low free concentrations of DTAB and at a higher temperature suggest endothermicity for enthalpy of interaction; the calorimetry enthalpy (delta Hcal) of interaction was smaller than the van't Hoff enthalpy (delta HvH) for BSA-DTAB interaction; and the aggregation of BSA increased with increasing DTAB concentration. This study suggests that BSA unfolding induced by DTAB follows a multistate transition model and does not follow the two-state mechanism assumed for most single subunit proteins.

  15. Bromide transport in different soils under no till and conventional tillage

    NASA Astrophysics Data System (ADS)

    Okada, Elena; Costa, José Luis; Bedmar, Francisco

    2013-04-01

    Prediction and description of water and solute movement within different soil tillage systems is essential when investigating pesticide contamination of soils and groundwater resources. Tillage systems can modify the chemical and biological properties of soil, and furthermore it can alter the pore system and structure. Conservation tillage can accelerate leaching of non reactive solutes and pesticides. Alternatively, solute transport is reduced in conventional tillage by diminishing functional macropores. Our research focused on the study of bromide transport in undisturbed soil columns from three different soils of Argentina, from the provinces of Córdoba, Buenos Aires, and Paraná, managed under no till (NT) and conventional till (CT). Bromide was used as a tracer solute. Experimental data was fitted using the convection dispersion equation (CDE) with the program CXTFIT 2.0. The parameters pore water velocity (v) and hydrodynamic dispersion (D) where estimated. Both NT and CT soils from the province of Paraná had the highest v compared to the other examined soils. Paraná soil has the highest clay content, which may influence its structure (increasing the amount of macropores) and possibly decreasing lateral mass exchange. Additionally, this soil had a higher v under NT practices than CT, while no significant difference between NT and CT were found in soils from Córdoba and Buenos Aires. Dispersion was relatively high in all soils, particularly for Paraná soil under NT. Dispersion was considerably much higher with NT compared to CT columns of the same soil.

  16. Tailoring acidity of HZSM-5 nanoparticles for methyl bromide dehydrobromination by Al and Mg incorporation

    PubMed Central

    2014-01-01

    Three kinds of HZSM-5 nanoparticles with different acidity were tailored by impregnating MgO or varying Si/Al ratios. Both the textural and acidic properties of the as-prepared nanoparticles were characterized by nitrogen adsorption-desorption measurements, X-ray diffraction (XRD), scanning electron microscopy (SEM), ammonia temperature-programmed desorption (NH3-TPD) and Fourier transform infrared spectroscopy (FTIR or Py-FTIR). It was found that the intensity of Lewis acid sites with weak strength was enhanced by impregnating MgO or reducing Al concentration, and such an enhancement could be explained by the formation of Mg(OH)+ or charge unbalance of the MgO framework on the surface of HZSM-5 support. The effect of HZSM-5 nanoparticles' acidity on methyl bromide dehydrobromination as catalyst was evaluated. As the results, MgHZ-360 catalyst with the highest concentration of Lewis acid sites showed excellent stability, which maintained methyl bromide conversion of up 97% in a period of 400 h on stream. Coke characterization by BET measurements and TGA/DTA and GC/MS analysis revealed that polymethylated naphthalenes species were formed outside the channels of the catalyst with higher acid intensity and higher Brønsted acid concentration during the initial period of reaction, while graphitic carbon formed in the channels of catalyst with lower acid intensity and higher Lewis acid concentration during the stable stage. PMID:25328502

  17. Functional consequences of ethidium bromide demyelination of the mouse ventral spinal cord

    PubMed Central

    Kuypers, Nicholas J.; James, Kurtis T.; Enzmann, Gaby U.; Magnuson, David S.K.; Whittemore, Scott R.

    2013-01-01

    Ethidium bromide (EB) has been extensively used in the rat as a model of spinal cord demyelination. However, this lesion has not been addressed in the adult mouse, a model with unlimited genetic potential. Here we characterize behavioral function, inflammation, myelin status and axonal viability following bilateral injection of 0.20 mg/mL ethidium bromide or saline into the ventral white matter (VWM) of female C57Bl/6 mice. EB-induced VWM demyelination significantly reduced spared VWM and Basso Mouse Scale (BMS) scores persisting out to 2 months. Chronic hindlimb dysfunction was accompanied by a persistent inflammatory response (demonstrated by CD45+ immunofluorescence) and axonal loss (demonstrated by NF-M immunofluorescence and electron microscopy; EM). These cellular responses differ from the rat where inflammation resolves by 3–4 weeks and axon loss is minimal following EB demyelination. As these data suggest that EB-injection in the mouse spinal cord is a non-remyelinating lesion, we sought to ask whether wheel running could promote recovery by enhancing plasticity of local lumbar circuitry independent of remyelination. This did not occur as BMS and Treadscan® assessment revealed no significant effect of wheel running on recovery. However, this study defines the importance of descending ventral motor pathways to locomotor function in the mouse as VWM loss results in a chronic hindlimb deficit. PMID:23466931

  18. Natural Oxidation of Bromide to Bromine in Evaporated Dead Sea Brines

    NASA Astrophysics Data System (ADS)

    Gavrieli, Ittai; Golan, Rotem; Lazar, Boaz; Baer, Gidi; Zakon, Yevgeni; Ganor, Jiwchar

    2016-04-01

    Highly evaporated Dead Sea brines are found in isolated sinkholes along the Dead Sea. Many of these brines reach densities of over 1.3 kg/L and pH<5 and are the product of evaporation of Dead Sea brine that drain into the sinkholes. The low pH and the reddish to brownish hue of these brines were an enigma until recently. Despite the rather high total alkalinity (TA) of the Dead Sea (3.826 mmol/kg) the pH of the Dead Sea brine is known to be slightly acidic with a value of ~6.3. In comparison, seawater with the same alkalinity would have a pH value well above 8.3, meaning that H+ activity is 100 fold lower than that of Dead Sea brine. In the present work we assess the apparent dissociation constant value of boric acid (K`B) for the Dead Sea brine and use it to explain the brine's low pH value. We then show that pH decreases further as the brine evaporates and salinity increases. Finally we explain the reddish hue of the hypersaline brines in the sinkholes as due to the presence of dissolved bromine. The latter is the product of oxidation of dissolved bromide, a process that is enabled by the low pH of the hypersaline brines and their high bromide concentration.

  19. Moving away from methyl bromide: political economy of pesticide transition for California strawberries since 2004.

    PubMed

    Mayfield, Erin N; Norman, Catherine Shelley

    2012-09-15

    We examine the progress of the phaseout of the use of the pesticide methyl bromide in the production of California field strawberries. This phaseout is required under the Montreal Protocol and has been contentious in this sector, which receives exemptions from the schedule initially agreed under the treaty, and in international negotiations over the future of the Protocol. We examine the various ex-ante predictions of the impacts on growers, consumers and trade patterns in light of several years of declining allocations under the Critical Use provisions of the Protocol and the 2010 approval of iodomethane for use in California and subsequent 2012 withdrawal of this alternative from the US market. We find that, contrary to ex-ante industry claims, the years of declining methyl bromide use have been years of rising yields, acreage, exports, revenues and market share for California growers, even when faced with a global recession and increased imports from Mexican growers who retain the right to use the chemical under the Protocol. This has implications for the Protocol as a whole and for the remainder of the US phaseout of this chemical in particular. PMID:22575205

  20. Fumigation of jute bags with ethylene oxide and methyl bromide to eradicate potato ring rot bacteria.

    PubMed

    RICHARDSON, L T; MONRO, H A

    1962-09-01

    In a series of full-scale tests, the effectiveness of various fumigant treatments for the eradication of potato ring rot bacteria from bulk lots of contaminated jute bags was evaluated. Survival of these bacteria on infested sample fibers located at various positions within and around a tightly wired bale was determined quantitatively from the growth lag in a liquid medium as indicated by the rate of turbidity development.Ethylene oxide, though highly toxic to Corynebacterium sepedonicum in laboratory tests, failed to penetrate the jute sufficiently to be effective in the interior of a bale. Methyl bromide showed better penetration, but was not sufficiently toxic at practical dosage levels. A mixture of 5% ethylene oxide and 10% methyl bromide achieved complete eradication throughout a bale in an 18-hr exposure period. On the basis of these results, eradication of ring rot bacteria from contaminated jute bags by fumigation with a combination of these two gases would appear to be feasible under commercial conditions.

  1. Interaction of removal Ethidium Bromide with Carbon Nanotube: Equilibrium and Isotherm studies

    PubMed Central

    2014-01-01

    Drinking water resources may be contaminated with Ethidium Bromide (EtBr) which is commonly used in molecular biology laboratories for DNA identification in electrophoresis. Carbon nanotubes are expected to play an important role in sensing, pollution treatment and separation techniques. In this study adsorption of Ethidium Bromide on single-walled carbon nanotubes (SWCNTs) and carboxylate group functionalized single-walled carbon nanotube (SWCNT-COOH) surfaces have been investigated by UV–vis spectrophotometer. The effect of contact time, initial concentration and temperature were investigated. The adsorbents exhibits high efficiency for EtBr adsorption and equilibrium can be achieved in 6 and 3 min for SWCNTs and SWCNT-COOH, respectively. The effect of temperature on adsorption of EtBr by toward adsorbents shows the process in this research has been endothermic. The results showed that the equilibrium data were well described by the Langmuir isotherm model, with a maximum adsorption capacity of 0.770 and 0.830 mg/g for SWCNTs and SWCNT-COOH, respectively. The adsorption of EtBr on SWCNT-COOH is more than SWCNTs surfaces. A comparison of kinetic models was evaluated for the pseudo first-order, pseudo second-order models. Pseudo second-order was found to agree well with the experimental data. PMID:24401790

  2. Iodide, bromide, and ammonium in hydraulic fracturing and oil and gas wastewaters: environmental implications.

    PubMed

    Harkness, Jennifer S; Dwyer, Gary S; Warner, Nathaniel R; Parker, Kimberly M; Mitch, William A; Vengosh, Avner

    2015-02-01

    The expansion of unconventional shale gas and hydraulic fracturing has increased the volume of the oil and gas wastewater (OGW) generated in the U.S. Here we demonstrate that OGW from Marcellus and Fayetteville hydraulic fracturing flowback fluids and Appalachian conventional produced waters is characterized by high chloride, bromide, iodide (up to 56 mg/L), and ammonium (up to 420 mg/L). Br/Cl ratios were consistent for all Appalachian brines, which reflect an origin from a common parent brine, while the I/Cl and NH4/Cl ratios varied among brines from different geological formations, reflecting geogenic processes. There were no differences in halides and ammonium concentrations between OGW originating from hydraulic fracturing and conventional oil and gas operations. Analysis of discharged effluents from three brine treatment sites in Pennsylvania and a spill site in West Virginia show elevated levels of halides (iodide up to 28 mg/L) and ammonium (12 to 106 mg/L) that mimic the composition of OGW and mix conservatively in downstream surface waters. Bromide, iodide, and ammonium in surface waters can impact stream ecosystems and promote the formation of toxic brominated-, iodinated-, and nitrogen disinfection byproducts during chlorination at downstream drinking water treatment plants. Our findings indicate that discharge and accidental spills of OGW to waterways pose risks to both human health and the environment. PMID:25587644

  3. Ionic liquid crystalline phases in 3-hexadecylimidazolium bromide and binary mixtures with 1-decanol.

    PubMed

    Li, Cuihua; He, Jinhua; Chen, Jiahui; Liu, Jianhong; Zhang, Qianling; Yu, Zhenqiang

    2011-07-15

    3-Hexadecylimidazolium bromide was synthesized and characterized showing formation of thermotropic smectic liquid crystals at temperatures above its melting point from 48.5 to 150.9°C. With decreasing temperature, the peak intensities in XRD patterns increase and full widths at half-maximum decrease, suggesting structural order increases with decreasing temperature. Compared with 1,2-dimethyl-3-hexadecyl-imidazolium bromide and hexafluorophosphate, the IL shows a lower melting point and less degree of chain interdigitation. The main reason is due to a more symmetrical structure and denser assembly of the IL molecules, which results in more steric resistance for the alkyl chain to interdigitate. The self-assembly behavior of the hydrophobic IL in an organic solvent was investigated showing SmA(2) lyotropic liquid crystalline phases. The first-order scattering peak shifts to lower q values with increasing IL content, which is opposite to the shift directions of the binary mixtures of the soluble imidazolium IL and water, indicating a different packing behavior of the hydrophobic IL in 1-decanol.

  4. The influence of nitrogen oxides on the activation of bromide and chloride in salt aerosol

    NASA Astrophysics Data System (ADS)

    Bleicher, S.; Buxmann, J. C.; Sander, R.; Riedel, T. P.; Thornton, J. A.; Platt, U.; Zetzsch, C.

    2014-04-01

    Experiments on salt aerosol with different salt contents were performed in a Teflon chamber under tropospheric light conditions with various initial contents of nitrogen oxides (NOx = NO + NO2). A strong activation of halogens was found at high NOx mixing ratios, even in samples with lower bromide contents such as road salts. The ozone depletion by reactive halogen species released from the aerosol, was found to be a function of the initial NOx mixing ratio. Besides bromine, large amounts of chlorine have been released in our smog chamber. Time profiles of the halogen species Cl2, Br2, ClNO2, BrNO2 and BrO, ClO, OClO and Cl atoms were simultaneously measured by various techniques (chemical ionization mass spectrometry, differential optical absorption spectrometry coupled with a multi-reflection cell and gas chromatography of hydrocarbon tracers for Cl and OH, employing cryogenic preconcentration and flame ionization detection). Measurements are compared to calculations by the CAABA/MECCA 0-D box model, which was adapted to the chamber conditions and took the aerosol liquid water content and composition into account. The model results agree reasonably with the observations and provide important information about the prerequisites for halogen release, such as the time profiles of the aerosol bromide and chloride contents as well as the aerosol pH.

  5. Modeling the dissociation conditions of salt hydrates and gas semiclathrate hydrates: application to lithium bromide, hydrogen iodide, and tetra-n-butylammonium bromide + carbon dioxide systems.

    PubMed

    Paricaud, Patrice

    2011-01-20

    A thermodynamic approach is proposed to determine the dissociation conditions of salt hydrates and semiclathrate hydrates. The thermodynamic properties of the liquid phase are described with the SAFT-VRE equation of state, and the solid-liquid equilibria are solved by applying the Gibbs energy minimization criterion under stoichiometric constraints. The methodology is applied to water + halide salt systems, and an excellent description of the solid-liquid coexistence curves is obtained. The approach is extended to the water + tetra-n-butylammonium bromide (TBAB) binary mixture, and an accurate representation of the solid-liquid coexistence curves and dissociation enthalpies is obtained. The van der Waals-Platteeuw (vdW-P) theory combined with the new model for salt hydrates is used to determine the dissociation temperatures of semiclathrate hydrates of TBAB + carbon dioxide. A good description of the dissociation pressures of CO(2) semiclathrate hydrates is obtained over wide temperature, pressure, and TBAB composition ranges (AAD = 10.5%). For high TBAB weight fractions the new model predicts a change of hydrate structure from type A to type B as the partial pressure of CO(2) is increased. The model can also capture a change of behavior with respect to TBAB concentration, which has been observed experimentally: an increase of the TBAB weight fraction leads to a stabilization of the gas semiclathrate hydrate at low initial TBAB concentrations below the stoichiometric composition but leads to a destabilization of the hydrate at TBAB concentrations above the stoichiometric composition. PMID:21171658

  6. Off-site air monitoring following methyl bromide chamber and building fumigations and evaluation of the ISCST air dispersion model

    SciTech Connect

    Barry, T.; Swgawa, R.; Wofford, P.

    1995-12-31

    The Department of Pesticide Regulation`s preliminary risk characterization of methyl bromide indicated an inadequate margin of safety for several exposure scenarios. Characterization of the air concentrations associated with common methyl bromide use patterns was necessary to determine specific scenarios that result in an unacceptable margin of safety. Field monitoring data were used in conjunction with the Industrial Source Complex, Short Tenn (ISCST) air dispersion model to characterize air concentrations associated with various types of methyl bromide applications. Chamber and building fumigations were monitored and modelled. For each fumigation the emission rates, chamber or building specifications and on-site meteorological data were input into the ISCST model. The model predicted concentrations were compared to measured air concentrations. The concentrations predicted by the ISCST model reflect both the pattern and magnitude of the measured concentrations. Required buffer zones were calculated using the ISCST output.

  7. Modification of the surfaces of Wyoming montmorillonite by the cationic surfactants alkyl trimethyl, dialkyl dimethyl, and trialkyl methyl ammonium bromides.

    PubMed

    Xi, Yunfei; Frost, Ray L; He, Hongping

    2007-01-01

    Surfaces of a Wyoming SWy-2 sodium montmorillonite were modified using microwave radiation through intercalation with the cationic surfactants octadecyl-trimethyl ammonium bromide, dimethyldioctadecylammonium bromide, and methyl-tri-octadecyl ammonium bromide by an ion exchange mechanism. Changes in the surfaces and structure were characterized using X-ray diffraction (XRD), thermal analysis (TG) and infrared (IR) spectroscopy. Different configurations of surfactants within montmorillonite interlayer are proposed based on d(001) basal spacings. A range of surfactant molecular environments within the surface-modified montmorillonite are proposed based upon their thermal decomposition. IR spectroscopy using a smart endurance single bounce diamond attenuated total reflection (ATR) cell has been used to study the changes in the spectra of CH asymmetric and symmetric stretching modes of the surfactants to provide more information of the surfactant molecular configurations.

  8. Combination of ozonation and photocatalysis for purification of aqueous effluents containing formic acid as probe pollutant and bromide ion.

    PubMed

    Parrino, F; Camera-Roda, G; Loddo, V; Palmisano, G; Augugliaro, V

    2014-03-01

    The treatment by advanced oxidation processes (AOPs) of waters contaminated by organic pollutants and containing also innocuous bromide ions may generate bromate ions as a co-product. In the present work heterogeneous photocatalysis and ozonation have individually been applied and in combination (integrated process) to degrade the organic compounds in water containing also bromide anions. The results show that: i) the sole photocatalysis does not produce bromate ions and in the case of its presence, it is able to reduce bromate to innocuous bromide ions; ii) the integration of photocatalysis and ozonation synergistically enhances the oxidation capabilities; and iii) in the integrated process bromate ions are not produced as long as some oxidizable organics are present.

  9. Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

    NASA Astrophysics Data System (ADS)

    Li, Bao-Sheng; Wang, Yuhuang; Proctor, Rupert S. J.; Zhang, Yuexia; Webster, Richard D.; Yang, Song; Song, Baoan; Chi, Yonggui Robin

    2016-09-01

    Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Here we disclose the generation of (nitro)benzyl radicals via N-heterocyclic carbene (NHC) catalysis under reductive conditions. The radical intermediates generated via NHC catalysis undergo formal 1,2-addition with ketones to eventually afford tertiary alcohol products. The overall process constitutes a formal polarity-inversion of benzyl bromide, allowing a direct coupling of two initially electrophilic carbons. Our study provides a new carbene-catalysed reaction mode that should enable unconventional transformation of (nitro)benzyl bromides under mild organocatalytic conditions.

  10. Carbene-catalysed reductive coupling of nitrobenzyl bromides and activated ketones or imines via single-electron-transfer process

    PubMed Central

    Li, Bao-Sheng; Wang, Yuhuang; Proctor, Rupert S. J.; Zhang, Yuexia; Webster, Richard D.; Yang, Song; Song, Baoan; Chi, Yonggui Robin

    2016-01-01

    Benzyl bromides and related molecules are among the most common substrates in organic synthesis. They are typically used as electrophiles in nucleophilic substitution reactions. These molecules can also be activated via single-electron-transfer (SET) process for radical reactions. Representative recent progress includes α-carbon benzylation of ketones and aldehydes via photoredox catalysis. Here we disclose the generation of (nitro)benzyl radicals via N-heterocyclic carbene (NHC) catalysis under reductive conditions. The radical intermediates generated via NHC catalysis undergo formal 1,2-addition with ketones to eventually afford tertiary alcohol products. The overall process constitutes a formal polarity-inversion of benzyl bromide, allowing a direct coupling of two initially electrophilic carbons. Our study provides a new carbene-catalysed reaction mode that should enable unconventional transformation of (nitro)benzyl bromides under mild organocatalytic conditions. PMID:27671606

  11. [Effects of bromide and ferric ions on formation of tri-halomethanes during disinfection of drinking water by chlorine].

    PubMed

    Zhu, Zhi-Liang; Wang, Jing; Ge, Yuan-Xin; Ma, Hong-Mei; Zhao, Jian-Fu

    2007-06-01

    Effects of bromide and ferric ions on the formation and distribution of tri-halomethanes (THMs) have been investigated. As disinfection by-product (DBP) model precursors of natural water, humic acid solutions were used and a series of experiments were conducted. The results showed that bromide in this reaction system not only contributed to the increase of brominated species, but also the total tri-halomethanes. When the concentration of Br(-) was 1.0 mg/L, the total amount of produced THMs reached to 270% of that without bromide ions. In the presence of bromide, ferric ions decreased the production of THMs at pH 6, but increased the production of THMs at pH 8, especially for the amount of tri-bromomethanes. When the concentration of Fe3+ was 5 mg/L, the amount of produced tri-bromomethanes had an increment of 54% (from 51.7 microg/L to 79.4 microg/L), and the total amount of THMs increased from 113.49 microg/L to 162.09 microg/L. Bromide ions had a significant effect on carcinogenicity risk in disinfection of drinking water by chlorine, and the co-existence of ferric ion and bromide in alkalescent environment can result in the biggest challenge on carcinogenicity risk. Under the condition of 0.2 mg/L Br(-), 5 mg/L Fe3+ and pH 6, the carcinogenicity risk increased 2.5 times than that without Br(-) and Fe3+, and much higher increment of 5.1 times appeared when pH was 8.

  12. Observations of Halogen Concentrations in Polar Snow near Barrow, Alaska Indicate that Bromide is Highly Affected by Atmospheric Chemistry

    NASA Astrophysics Data System (ADS)

    Alvarez-Aviles, L.; Simpson, W. R.; Douglas, T. A.; Sturm, M.; Domine, F.

    2004-12-01

    The polar atmosphere shows unique and important atmospheric chemistry in the related phenomena of ozone depletion and mercury deposition. During these ozone depletion episodes (ODEs), ozone is depleted from background levels to nearly zero. At the same time, gas-phase mercury is oxidized to reactive gaseous mercury that subsequently deposits potentially providing a source of toxic mercury to the Arctic ecosystem. These ODEs are clearly related to reactive halogen chemistry and particularly gaseous bromine species (Br and BrO). The origin of these reactive halogen species is most likely sea salts that are liberated by poorly understood chemistry, possibly assisted by frost flower formation. These reactive halogen species eventually react to form the stable halogen anions (e.g. Bromide, Br-), that is subsequently deposited to the snowpack. Therefore, we undertook a study of halogens in the snow in the vicinity of Barrow, Alaska. Snow samples were collected in three phases along a 100 km transect from shore to inland in 2004. Phase I (29 Feb - 5 Mar), phase II (31 Mar - 13 Apr), and phase III (7 May - 11 May) snow samples were analyzed for ions to investigate snow-air interactions. Anions (F-, Cl-, Br-, NO3-, SO42-) were analyzed with ion chromatography, and cations (Ca2+, Mg2+ and Na+) with flame atomic absorption spectroscopy. Frost flower samples were approximately 4 times more concentrated in ions than sea water, but most ions (except sulfate and to a smaller extent sodium) were not fractionated with respect to sea water. The bromide to chloride ratio in the frost flowers was identical to that of sea water, indicating that possible fractionation of bromide during frost flower formation does not occur. The sulfate to chloride ratio in frost flowers was about half of that in sea water, indicating fractionation probably due to mirabalite (Na2SO4 hydrate) precipitation. In snow samples, the bromide to chloride ratio showed bromide depletion in salty samples (higher

  13. Influence of chloride on modification of unsaturated phosphatidylcholines by the myeloperoxidase/hydrogen peroxide/bromide system.

    PubMed

    Panasenko, Oleg M; Vakhrusheva, Tatyana; Tretyakov, Vadim; Spalteholz, Holger; Arnhold, Juergen

    2007-01-01

    The leukocyte enzyme myeloperoxidase (MPO) is capable of catalyzing the oxidation of chloride and bromide ions, at physiological concentrations of these substrates, by hydrogen peroxide, generating hypochlorous acid (HOCl) and hypobromous acid (HOBr), respectively. Our previous results showed that the hypohalous acids formed react with double bonds in phosphatidylcholines (PCs) to produce chloro- and bromohydrins. Lysophosphatidylcholine (lyso-PC) is additionally formed in PCs with two or more double bonds. This study was conducted to determine the effect physiological chloride concentration (140 mM) has on the formation of bromohydrins and lyso-PC from unsaturated PC upon treatment with the myeloperoxidase/hydrogen peroxide/bromide (MPO/H2O2/Br-) system using physiological bromide concentrations (20-100 microM). The composition of reaction products was analyzed by matrix-assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI-TOF MS). With monounsaturated PC, we demonstrated that the rate and extent of mono-bromohydrin formation were higher in the samples with 140 mM chloride compared to those with no added chloride. Moreover, mono-bromohydrin came to be the major product and no mono-chlorohydrin was observed already at 60 microM bromide. We attributed these effects to the involvement of HOBr arising from the reaction of MPO-derived HOCl with bromide rather than to the exchange of bromide with chlorine atoms of chlorohydrins or direct formation of HOBr by MPO. The presence of chloride shifted the pH optimum for mono-bromohydrin formation (pH 5.0) toward neutral values, and a significant yield of mono-bromohydrin was detected at physiological pH values (7.0-7.4). For polyunsaturated PC, chloride enhanced also lyso-PC production, the effect being pronounced at bromide concentrations below 40 microM. The results indicate that at physiological levels of chloride and bromide, chloride promotes MPO-mediated formation of bromohydrins and lyso

  14. Spectral and Non Radiative Decay Studies of Lead Di Bromide Single Crystals by Mode Matched Thermal Lens Technique.

    PubMed

    Rejeena, I; Lillibai, B; Thomas, V; Nampoori, V P N; Radhakrishnan, P

    2016-07-01

    In the present paper, the investigations on the non radiative decay mechanism, optical band gap determination from absorption spectroscopic studies and fluorescence emission by photo luminescence techniques using different excitation wavelengths on gel derived lead di bromide single crystals are reported. Non radiative decay of the sample is studied using high sensitive dual beam mode matched thermal lens technique. For the thermal lensing experiment the crystal in solution phase is incorporated with rhodamine 6G dye for enhancing the absorption of the crystal sample. The thermal diffusivity of lead di bromide is determined using the probe beam intensity v/s time measurements. PMID:27165040

  15. Comparative in vitro study of the effectiveness of Green tea extract and common storage media on periodontal ligament fibroblast viability

    PubMed Central

    Adeli, Fahimeh; Zabihi, Ebrahim; Abedian, Zeinab; Gharekhani, Samane; Pouramir, Mahdi; Khafri, Soraya; Ghasempour, Maryam

    2016-01-01

    Objective: Green tea extract (GTE) was shown to be effective in preserving periodontal ligament fibroblasts (PDLFs) of avulsed teeth. This study aimed at determining the potential of GTE in preserving the viability of PDLFs comparing with different storage media. Materials and Methods: Periodontal ligament cells were obtained from freshly extracted healthy impacted third molars and cultured in Dulbecco's Modified Eagle Medium (DMEM). Cell viability was determined by storing the cells in seven media; DMEM, tap water, Hank's balanced salt solution (HBSS), whole milk, hypotonic sucrose solution, GTE, and GTE + sucrose for 1, 2, 4, and 24 h at 37°C using tetrazolium salt-based colorimetric (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) assay. Statistical analysis was performed by one-way analysis of variance and post hoc tests. Results: GTE showed significantly higher protective effect than HBSS at 2, 4, and 24 h (P = 0.009, P = 0.02, P = 0.016), DMED at 2 h (P = 0.003), and milk at 4 h (P = 0.039). Conclusion: Although with undesirable osmolality and pH, GTE had a good ability in preserving the PDLFs comparing with other studied media. PMID:27403063

  16. An innovative experimental design reveals the spatial correlation between landuse, irrigation properties, and bromide leaching

    NASA Astrophysics Data System (ADS)

    Schwen, A.; Yang, Y.; Walton, J.; Wendroth, O.

    2012-04-01

    Understanding the relationship between leaching of pesticides and soil hydraulic properties under different land use conditions is critical to our understanding of the flow of water and solutes in soils and efforts to model these flow characteristics. One problem inherent in the measurement of solute leaching in field experiments is the considerable high natural spatial variability of flow-controlling soil properties. Thus, analyzing treatment effects based on the mean and the variance of observations can become obsolete if there is a huge inherent variance in the set of measurements. Moreover, no spatial range of influence can be derived from the observations. To overcome this limitation, the spatial covariance and cross-variance between measurements was used as decision and quality criteria in the present study. This study aims to demonstrate that focussing on the spatial covariance of observations and considering their spatial process can provide a measure of spatial representativity or scale-specific variance. We introduce a novel experimental scheme, where the treatments are arranged in a scale-dependent manner. In a field trial in Lexington, Kentucky, bromide leaching under two contrasting land use systems (no-till agricultural crops vs. pasture) was compared. After surface application of tracer solution (KBr), the experimental field was irrigated using different time-delays (1, 4 and 24 hours) as well as two different irrigation amounts and two different intensities. At the end, the KBr-concentration in the soil profile was determined using auger samplings. The data was correlated with the applied boundary conditions by spatial statistical methods such as semivariograms, cross-semivariograms and spectral analysis. Our results show distinct differences in the leaching behaviour between the two analyzed land uses with an deeper infiltration in the no-till agricultural field. This can be partly related to a higher initial soil water content in this treatment

  17. Studies on nitrile rubber degradation in zinc bromide completion fluid and its prevention by surface fluorination

    NASA Astrophysics Data System (ADS)

    Vega-Cantu, Yadira Itzel

    Poly(acrylonitrile-co-butadiene) or nitrile-butadiene rubber (NBR) is frequently used as an O-ring material in the oil extraction industry due to its excellent chemical properties and resistance to oil. However, degradation of NBR gaskets is known to occur during the well completion and oil extraction process where packers are exposed to completion fluids such as ZnBr2 brine. Under these conditions NBR exhibits accelerated chemical degradation resulting in embrittlement and cracking. Samples of NBR, poly(acrylonitrile) (PAN) and poly(butadiene) (PB) have been exposed to ZnBr2 based completion fluid, and analyzed by ATR and diffuse reflectance IR. Analysis shows the ZnBr2 based completion fluid promotes hydrolysis of the nitrile group to form amides and carboxylic groups. Analysis also shows that carbon-carbon double bonds in NBR are unaffected after short exposure to zinc bromide based completion fluid, but are quickly hydrolyzed in acidic bromide mixtures. Although fluoropolymers have excellent chemical resistance, their strength is less than nitrile rubber and replacing the usual gasket materials with fluoroelastomers is expensive. However, a fluoropolymer surface on a nitrile elastomer can provide the needed chemical resistance while retaining their strength. In this study, we have shown that this can be achieved by direct fluorination, a rather easy and inexpensive process. Samples of NBR O-rings have been fluorinated by exposure to F2 and F2/HF mixtures at various temperatures. Fluorination with F 2 produces the desired fluoropolymer layer; however, fluorination by F2/HF mixtures gave a smoother fluorinated layer at lower temperatures and shorter times. Fluorinated samples were exposed to ZnBr2 drilling fluid and solvents. Elemental analysis shows that the fluorinated layer eliminates ZnBr2 diffusion into the NBR polymeric matrix. It was also found that surface fluorination significantly retards the loss of mechanical properties such as elasticity, tensile

  18. Tribromopyrrole, brominated acids, and other disinfection byproducts produced by disinfection of drinking water rich in bromide.

    PubMed

    Richardson, Susan D; Thruston, Alfred D; Rav-Acha, Chaim; Groisman, Ludmila; Popilevsky, Inna; Juraev, Olga; Glezer, Victor; McKague, A Bruce; Plewa, Michael J; Wagner, Elizabeth D

    2003-09-01

    Using gas chromatography/mass spectrometry (GC/MS), we investigated the formation of disinfection byproducts (DBPs) from high bromide waters (2 mg/L) treated with chlorine or chlorine dioxide used in combination with chlorine and chloramines. This study represents the first comprehensive investigation of DBPs formed by chlorine dioxide under high bromide conditions. Drinking water from full-scale treatment plants in Israel was studied, along with source water (Sea of Galilee) treated under carefully controlled laboratory conditions. Select DBPs (trihalomethanes, haloacetic acids, aldehydes, chlorite, chlorate, and bromate) were quantified. Many of the DBPs identified have not been previously reported, and several of the identifications were confirmed through the analysis of authentic standards. Elevated bromide levels in the source water caused a significant shift in speciation to bromine-containing DBPs; bromoform and dibromoacetic acid were the dominant DBPs observed, with very few chlorine-containing compounds found. Iodo-trihalomethanes were also identified, as well as a number of new brominated carboxylic acids and 2,3,5-tribromopyrrole, which represents the first time a halogenated pyrrole has been reported as a DBP. Most of the bromine-containing DBPs were formed during pre-chlorination at the initial reservoir, and were not formed by chlorine dioxide itself. An exception wasthe iodo-THMs, which appeared to be formed by a combination of chlorine dioxide with chloramines or chlorine (either added deliberately or as an impurity in the chlorine dioxide). A separate laboratory study was also conducted to quantitatively determine the contribution of fulvic acids and humic acids (from isolated natural organic matter in the Sea of Galilee) as precursor material to several of the DBPs identified. Results showed that fulvic acid plays a greater role in the formation of THMs, haloacetic acids, and aldehydes, but 2,3,5-tribromopyrrole was produced primarily from humic

  19. Scale-Specific Field Bromide Transport and Identification of Leaching at Different Scales

    NASA Astrophysics Data System (ADS)

    Wendroth, O.; Matocha, C. J.; Vasquez, V.

    2012-04-01

    Inherent soil spatial variability complicates the experimental diagnosis and understanding of tracer transport at the field scale. Spatial soil processes vary at different scales and the study of rainfall scenarios on solute transport appears obsolete using a randomized treatment design. The objectives of this study were to derive a field experimental approach resulting in a spatially representative process of bromide leaching depth under different rainfall treatments and to develop a statistical protocol that helps to quantify the spatial covariance structure and decompose scale-specific treatment effects. In a Maury silt loam soil in Kentucky, treatments of rainfall amount, intensity and time between surface application of the tracer and subsequent rainfall initiation were laid out across different scales. Bromide concentrations were measured from soil samples taken every 0.5 m in horizontal distance at 0.1 cm depth increments down to 0.5 m. Spatial variation scales of the leaching behavior and their association with scales of spatial treatment distributions were identified using semi- and cross-semivariograms and co-spectral analysis. In a subsequent analysis, the impact of rainfall and intensity representing the variation at the large scale was separated from the small-scale effect imposed through the time delay between tracer application and rainfall. This decomposition of scale-specific variation was based on an additive state-space model approach adapted from time series analysis. The large-scale trend component was then described in an autoregressive state-space model. In our case, the origin of the large-scale component of bromide leaching was known. In many field and landscape experiments, the cause for large scale variation is unknown when small-scale treatments are imposed on top of large scale variation. The analysis applied here reveals opportunities to address and quantify the causes of large scale processes. Therefore, the experimental and

  20. Description of Toluene Inhibition of Methyl Bromide Biodegradation in Seawater and Isolation of a Marine Toluene Oxidizer That Degrades Methyl Bromide

    PubMed Central

    Goodwin, Kelly D.; Tokarczyk, Ryszard; Stephens, F. Carol; Saltzman, Eric S.

    2005-01-01

    Methyl bromide (CH3Br) and methyl chloride (CH3Cl) are important precursors for destruction of stratospheric ozone, and oceanic uptake is an important component of the biogeochemical cycle of these methyl halides. In an effort to identify and characterize the organisms mediating halocarbon biodegradation, we surveyed the effect of potential cometabolic substrates on CH3Br biodegradation using a 13CH3Br incubation technique. Toluene (160 to 200 nM) clearly inhibited CH3Br and CH3Cl degradation in seawater samples from the North Atlantic, North Pacific, and Southern Oceans. Furthermore, a marine bacterium able to co-oxidize CH3Br while growing on toluene was isolated from subtropical Western Atlantic seawater. The bacterium, Oxy6, was also able to oxidize o-xylene and the xylene monooxygenase (XMO) pathway intermediate 3-methylcatechol. Patterns of substrate oxidation, lack of acetylene inhibition, and the inability of the toluene 4-monooxygenase (T4MO)-containing bacterium Pseudomonas mendocina KR1 to degrade CH3Br ruled out participation of the T4MO pathway in Oxy6. Oxy6 also oxidized a variety of toluene (TOL) pathway intermediates such as benzyl alcohol, benzylaldehyde, benzoate, and catechol, but the inability of Pseudomonas putida mt-2 to degrade CH3Br suggested that the TOL pathway might not be responsible for CH3Br biodegradation. Molecular phylogenetic analysis identified Oxy6 to be a member of the family Sphingomonadaceae related to species within the Porphyrobacter genus. Although some Sphingomonadaceae can degrade a variety of xenobiotic compounds, this appears to be the first report of CH3Br degradation for this class of organism. The widespread inhibitory effect of toluene on natural seawater samples and the metabolic capabilities of Oxy6 indicate a possible link between aromatic hydrocarbon utilization and the biogeochemical cycle of methyl halides. PMID:16000753

  1. Description of toluene inhibition of methyl bromide biodegradation in seawater and isolation of a marine toluene oxidizer that degrades methyl bromide.

    PubMed

    Goodwin, Kelly D; Tokarczyk, Ryszard; Stephens, F Carol; Saltzman, Eric S

    2005-07-01

    Methyl bromide (CH3Br) and methyl chloride (CH3Cl) are important precursors for destruction of stratospheric ozone, and oceanic uptake is an important component of the biogeochemical cycle of these methyl halides. In an effort to identify and characterize the organisms mediating halocarbon biodegradation, we surveyed the effect of potential cometabolic substrates on CH3Br biodegradation using a 13CH3Br incubation technique. Toluene (160 to 200 nM) clearly inhibited CH3Br and CH3Cl degradation in seawater samples from the North Atlantic, North Pacific, and Southern Oceans. Furthermore, a marine bacterium able to co-oxidize CH3Br while growing on toluene was isolated from subtropical Western Atlantic seawater. The bacterium, Oxy6, was also able to oxidize o-xylene and the xylene monooxygenase (XMO) pathway intermediate 3-methylcatechol. Patterns of substrate oxidation, lack of acetylene inhibition, and the inability of the toluene 4-monooxygenase (T4MO)-containing bacterium Pseudomonas mendocina KR1 to degrade CH3Br ruled out participation of the T4MO pathway in Oxy6. Oxy6 also oxidized a variety of toluene (TOL) pathway intermediates such as benzyl alcohol, benzylaldehyde, benzoate, and catechol, but the inability of Pseudomonas putida mt-2 to degrade CH3Br suggested that the TOL pathway might not be responsible for CH3Br biodegradation. Molecular phylogenetic analysis identified Oxy6 to be a member of the family Sphingomonadaceae related to species within the Porphyrobacter genus. Although some Sphingomonadaceae can degrade a variety of xenobiotic compounds, this appears to be the first report of CH3Br degradation for this class of organism. The widespread inhibitory effect of toluene on natural seawater samples and the metabolic capabilities of Oxy6 indicate a possible link between aromatic hydrocarbon utilization and the biogeochemical cycle of methyl halides. PMID:16000753

  2. Effects of bromide and iodide ions on the formation of disinfection by-products during ozonation and subsequent chlorination of water containing biological source matters.

    PubMed

    Zha, Xiao-song; Liu, Yan; Liu, Xiang; Zhang, Qiang; Dai, Rui-hua; Ying, Ling-wen; Wu, Jin; Wang, Jing-ting; Ma, Luming

    2014-02-01

    This study aims to investigate the influence of the coexistence of halogen ions (bromide/iodide) and biological source matters on the speciation and yield of trihalomethanes (THMs), haloacetic acids (HAAs), and N-nitrosodimethylamine (NDMA) during the ozonation and subsequent chlorination of water. The results show that the concentrations of brominated THMs and iodinated THMs increased with increasing bromide and iodide concentration. These results may be attributed to the higher reactivity of hypobromous acid and hypoiodous acid generated from the ozonation and subsequent chlorination in the presence of bromide or iodide ions. The presence of bromide increased the species of brominated HAAs. There was a shift from chlorinated HAAs to brominated HAAs after increasing the concentration of bromide. The effect of iodide on HAA formation was more complex than bromide. For most samples, the concentration of total HAAs (T-HAAs) increased to the maximum and then decreased with increasing iodide concentration. The components of the organic precursors also significantly influenced the formation of brominated and iodinated disinfection by-products (Br-DBPs and I-DBPs). Humic acids produced more CHBr3 (596.60 μg/L) than other organic materials. Microcystis aeruginosa cells produced the most tribromoacetic acid (TBAA, 84.16 μg/L). Furthermore, the yield of NDMA decreased with increasing bromide concentration, indicating that the formation of NDMA was inhibited by the high concentration of bromide.

  3. [Investigation of the oxidation reaction of O3 with bromide ion in aqueous solution].

    PubMed

    Yu, Xiao-Ting; Zhang, Jia-Hui; Pan, Xun-Xi; Zhang, Ren-Xi; Hou, Hui-Qi

    2012-09-01

    The reaction mechanism of O3 with bromide ion in aqueous solution was studied by ion chromatography and UV-Vis spectrometry instruments. Ion chromatography analysis showed that only 10% of Br- which was oxidized by ozone was formed into bromate ion. The results demonstrated that the final products of the oxidation reaction were identified as Br2 and Br3- except for BrO3-. The formation of Br3- which was yielded from the reaction of Br2 with Br- was the major process in the reaction of Br attacked by O3. The characteristic absorption spectrum of Br3- with an absorption peak at 260 nm was also investigated. The results may provide helpful information about the mechanism of the oxidation reaction of Br- with O3 and fate of Br- or its derivatives in the environment by the oxidation processes.

  4. Biological properties of sodium alkyl methyl ester sulfonate/alkyltrimethylammonium bromide surfactant mixtures.

    PubMed

    Wong, S P; Lim, W H; Cheng, S F; Chuah, C H

    2012-01-01

    Quaternary ammonium compounds (QACs) are commonly used as disinfectant in medical care, food industry, detergents and glue industries. This is due to a small concentration of QACs is sufficient to inhibit the growth of various bacteria strains. In this work, the inhibitive power of cationic surfactants, alkyltrimethylammonium bromide (C(n)TAB) in the presence of anionic surfactants, sodium alkyl methyl ester α-sulfonate (C(n)MES) was studied. The growth inhibition test with gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria were used to determine the toxicity of single and mixed surfactants. Results from this work showed that certain mixed surfactants have lower minimum inhibition concentration (MIC) as compared to the single C(n)TAB surfactants. Besides that, it was also found that alkyl chain length and the mixing ratios of the surfactants play a significant role in determining the mixture inhibitive power.

  5. Degradation of tetraphenylphosphonium bromide at high pH and its effect on radionuclide solubility.

    PubMed

    Aldridge, S; Warwick, P; Evans, N; Vines, S

    2007-01-01

    Recently, tetraphenylphosphonium bromide (TPPB) has been used to remove technetium from some radioactive waste streams. However, before TPPB could be approved for use it was necessary to show that TPPB and its degradation products would not have a significant detrimental effect on post-closure performance of a radioactive waste repository. TPPB is known to be stable at neutral pH, however, under alkaline conditions it degrades by an alkaline hydrolysis mechanism to triphenylphosphonium oxide (TPPO). Degradation can also occur by radiolysis to produce triphenylphosphine (TPP). The kinetics of the alkaline hydrolysis degradation of TPPB is described and the solubility of europium, iodine, nickel, technetium(VII) and uranium(VI) in aqueous solutions of TPPB and its degradation products is reported. These results were used to support the use of TPPB in removing technetium from some waste streams.

  6. Palladium-Catalyzed Cross Coupling of Secondary and Tertiary Alkyl Bromides with a Nitrogen Nucleophile

    PubMed Central

    2016-01-01

    We report a new class of catalytic reaction: the thermal substitution of a secondary and or tertiary alkyl halide with a nitrogen nucleophile. The alkylation of a nitrogen nucleophile with an alkyl halide is a classical method for the construction of C–N bonds, but traditional substitution reactions are challenging to achieve with a secondary and or tertiary alkyl electrophile due to competing elimination reactions. A catalytic process could address this limitation, but thermal, catalytic coupling of alkyl halides with a nitrogen nucleophile and any type of catalytic coupling of an unactivated tertiary alkyl halide with a nitrogen nucleophile are unknown. We report the coupling of unactivated secondary and tertiary alkyl bromides with benzophenone imines to produce protected primary amines in the presence of palladium ligated by the hindered trialkylphosphine Cy2t-BuP. Mechanistic studies indicate that this amination of alkyl halides occurs by a reversible reaction to form a free alkyl radical. PMID:27725963

  7. Bio-conjugated silver nanoparticles: from Ocimum sanctum and role of cetyltrimethyl ammonium bromide.

    PubMed

    Zaheer, Zoya; Rafiuddin

    2013-08-01

    In this paper we have reported the spectrophotometeric and transmission electron microscopic (TEM) data to the shape-directing role of cetyltrimethylammonium bromide (CTAB) on the green extra-cellular synthesis of bio-conjugated Ag-nanoparticles using Ocimum sanctum leaves extract. TEM images revealed that the nanoparticles are mostly spherical (average particle size ranged from 18 to 35nm) with some truncated triangular nanoplates, aggregated in a beautiful manner to yield locket-like silver and capped by a thin layer of biomolecules of O. sanctum, whereas nanoparticles are highly poly-dispersed in presence of CTAB. The shape and position of wavelength maxima strongly depends on the reaction time, [leaves extract] and [CTAB]. The visual observations also suggest that the prefect transparent silver sol becomes turbid in presence of CTAB after some time. PMID:23524081

  8. Characterization of the major cyanogen bromide fragment of alpha-A crystallin

    NASA Technical Reports Server (NTRS)

    Ifeanyi, F.; Takemoto, L.; Spooner, B. S. (Principal Investigator)

    1991-01-01

    Alpha crystallin from the bovine lens has been digested with cyanogen bromide, and the major fragment (CB-1) has been purified using reverse phase HPLC. Characterization of this fragment by Edman degradation and antisera to synthetic peptides indicates that it originates from alpha-A crystallin, but lacks the N-terminal methionine and the last 35 amino acids from the C-terminus of the molecule. The purified CB-1 fragment binds as well as native alpha crystallin to lens membrane, but is unable to self-assemble into the correct size of high molecular weight oligomeric complexes characteristic of the intact alpha-A chain. Together, these results demonstrate that the alpha-A chain is comprised of at least two functional domains, one of which is involved in binding of alpha-A crystallin to lens membrane, and another which is necessary for correct self-assembly of the molecule into high molecular weight oligomers.

  9. Evaluation of containment and control options for methyl bromide in commodity treatment. Final report

    SciTech Connect

    DeWolf, G.B.; Harrison, M.R.

    1994-07-01

    Methyl bromide (MeBr), with the chemical formula CH3Br, also called bromomethane, is listed by the 1991 Montreal Protocol as an ozone depleting chemical similar to the other halogenated hydrocarbons such as the chloro-fluorocarbons (CFCs). The U.S. Environmental Protection Agency's (EPA's) regulations authorized by the Clean Air Act (CAA) call for a phaseout of MeBr by the year 2001. MeBr is widely used in United States agriculture as a fumigant. This study has gathered preliminary data that can be used to determine if some of the essential agricultural commodity fumigation applications for MeBr could be continued by the use of some emission control methods on those commodity fumigation applications.

  10. Growth and characterization of Cadmium Thiosemicarbazide Bromide crystals for antibacterial and nonlinear optical applications

    NASA Astrophysics Data System (ADS)

    Thomas Joseph Prakash, J.; Martin Sam Gnanaraj, J.

    2015-01-01

    Semiorganic nonlinear optical crystals of Cadmium Thiosemicarbazide Bromide was grown by slow evaporation solution growth technique. The unit cell parameters were estimated by subjecting the crystals to single crystal X-ray diffraction. The grown crystals were subjected to Powder X-ray diffraction for analyzing the crystalline nature of the sample. FTIR studies reveal the functional groups and the optical characters were analyzed by UV-Vis spectral studies. Mechanical stability of the sample was assessed by Vicker's micro hardness test. The presence of surface dislocations was identified by chemical etching technique. Antibacterial study was carried out against ACDP declared harmful pathogens. SHG efficiency of CTSB crystal was tested using Nd: YAG laser and it was found to be ∼1.8 times that of potassium dihydrogen phosphate.

  11. Growth, photoluminescence, thermal and mechanical behaviour of Ethyltriphenylphosphonium bromide dihydrate crystal

    NASA Astrophysics Data System (ADS)

    Parthasarathy, M.; Gopalakrishnan, R.

    2013-10-01

    Single crystal of Ethyltriphenylphosphonium bromide dihydrate (ETPB) was grown by slow evaporation solution growth technique. The grown crystal was confirmed by single crystal X-ray diffraction. The functional groups and vibrational frequencies were identified using FT-IR and FT-Raman spectral analyses. Optical properties were studied by UV-Visible and photoluminescence spectroscopic techniques to explore its efficacy towards device fabrication. Thermal characteristics of ETPB were studied using the TGA/DTA and DSC response curves. The mechanical behaviour of the grown crystal was studied using Vicker's microhardness tester and the work hardening coefficient was evaluated. The second harmonic generation of the title compound was tested by Kurtz-Perry powder technique.

  12. Spectroscopic probe of the competitive binding of ethidium bromide and neomycin to DNA

    NASA Astrophysics Data System (ADS)

    Pal, Medini Kanta; Ghosh, Jimut Kanti

    1995-03-01

    The three spectroscopic changes of ethidium bromide (EB) on its binding to DNA, namely red-shift of the νmax, enhancement of fluorescence and induced dichroism are utilized to study the competitive binding of neomycin (NMC) and EB to DNA. Reversion of νmax, decrease in fluorescence and reduction of dichroism of DNA-EB on addition of NMC shows that the binding of NMC and EB to DNA is competitive in nature, over a limited concentration of the polymer. The binding constant of EB-DNA falls from 4.00 × 10 6 to 2.27 × 10 4 1 mol -1 in the presence of added NMC.

  13. Copper bromide vapor brightness amplifiers with 100 kHz pulse repetition frequency

    NASA Astrophysics Data System (ADS)

    Trigub, M. V.; Evtushenko, G. S.; Torgaev, S. N.; Shiyanov, D. V.; Evtushenko, T. G.

    2016-10-01

    The paper presents a laser monitor with 10 μs time-resolution based on a high-frequency copper bromide vapor brightness amplifier. A sync circuit has been designed for single-pulse imaging. The analysis of amplifying characteristics of the active elements and active optical system (laser monitor) parameters allowed to determine the optimal concentration of HBr at which the images can be obtained with minimum distortions. For the active element operating at high frequencies (more than 50 kHz) as a brightness amplifier, the concentration of HBr must be lower than that needed for obtaining the maximum output power. The limiting brightness temperature of the background radiation which does not affect the image quality is determined. The potential feasibility of using a proposed brightness amplifier for visualizing processes blocked from viewing by the background radiation with the brightness temperature up to 8000 K is demonstrated.

  14. Modelling disinfection by-products formation in bromide-containing waters.

    PubMed

    Fabbricino, M; Korshin, G V

    2009-09-15

    A kinetic model capable of simulating by-products formation in bromide-containing waters during disinfection processes is presented in this paper. The model is based on two parallel sequences of incorporation and oxidation reactions induced by bromine or chlorine reacting with natural organic matter (NOM). Each sequence starts from a different type of NOM functionality that has its own set of specific reaction rate. Decay reactions of NOM and halogenated intermediates are assumed to follow a first order kinetic, while disinfection by-product (DBP) generation reactions are simulated introducing so-called splitting coefficients. This approach allows obtaining explicit expressions for DBP species. Model's results are compared with experimental data obtained for seawater samples. Comparison of the data confirms the model's ability to predict DBPs formation with high precision. PMID:19299084

  15. Interaction between DNA and trimethyl-ammonium bromides with different alkyl chain lengths.

    PubMed

    Cheng, Chao; Ran, Shi-Yong

    2014-01-01

    The interaction between λ--DNA and cationic surfactants with varying alkyl chain lengths was investigated. By dynamic light scattering method, the trimethyl-ammonium bromides-DNA complex formation was shown to be dependent on the length of the surfactant's alkyl chain. For surfactants with sufficient long alkyl chain (CTAB, TTAB, DTAB), the compacted particles exist with a size of ~60-110 nm at low surfactant concentrations. In contrast, high concentration of surfactants leads to aggregates with increased sizes. Atomic force microscope scanning also supports the above observation. Zeta potential measurements show that the potential of the particles decreases with the increase of surfactant concentration (CTAB, TTAB, DTAB), which contributes much to the coagulation of the particles. For OTAB, the surfactant with the shortest chain in this study, it cannot fully neutralize the charges of DNA molecules; consequently, the complex is looser than other surfactant-DNA structures.

  16. Morphology characterization and single-molecule study of DNA-dodecyltrimethylammonium bromide complex.

    PubMed

    Ran, Shi-Yong; Wang, Yan-Wei; Yang, Guang-Can; Zhang, Lin-Xi

    2011-04-28

    DNA compaction induced by dodecyltrimethylammonium bromide (DTAB) is studied using atomic force microscopy (AFM) and magnetic tweezers. The morphology of DNA-DTAB complex is dependent on the DTAB concentration and incubation time. With magnesium ions, the complexes show rod- and network-like structures after approximately 5 min of incubation at low DTAB concentrations. With increasing incubation time, more toroids and globules appeared, resulting in the formation of scattered condensed particles. At high DTAB concentrations, the complexes show swollen globular structures independent of the incubation time. The compaction and unraveling of the DNA-DTAB complex are also analyzed at the single-molecule level using magnetic tweezers. The extension-time curves show a staircase structure with typical sizes of ∼40, 60, 80, and 112 nm, suggesting that the complexes are well organized and more compacted than those induced by multivalent ions. Finally, the high DTAB concentration stabilized the complex and increased the unraveling energy barrier.

  17. Interaction between DNA and Trimethyl-Ammonium Bromides with Different Alkyl Chain Lengths

    PubMed Central

    Cheng, Chao; Ran, Shi-Yong

    2014-01-01

    The interaction between λ—DNA and cationic surfactants with varying alkyl chain lengths was investigated. By dynamic light scattering method, the trimethyl-ammonium bromides-DNA complex formation was shown to be dependent on the length of the surfactant's alkyl chain. For surfactants with sufficient long alkyl chain (CTAB, TTAB, DTAB), the compacted particles exist with a size of ~60–110 nm at low surfactant concentrations. In contrast, high concentration of surfactants leads to aggregates with increased sizes. Atomic force microscope scanning also supports the above observation. Zeta potential measurements show that the potential of the particles decreases with the increase of surfactant concentration (CTAB, TTAB, DTAB), which contributes much to the coagulation of the particles. For OTAB, the surfactant with the shortest chain in this study, it cannot fully neutralize the charges of DNA molecules; consequently, the complex is looser than other surfactant-DNA structures. PMID:24574926

  18. The matlockite-type praseodymium(III) oxide bromide PrOBr.

    PubMed

    Talmon-Gros, Pia; Schurz, Christian M; Schleid, Thomas

    2011-12-01

    The crystal structure of the praseodymium(III) oxide bromide, PrOBr, can be best described with layers of agglomerated square anti-prisms [PrO(4)Br(4)](9-). These slabs are stacked along the c axis and linked via two different secondary contacts between Pr(3+) and Br(-). The Pr(3+) cations occupy the Wyckoff site 2c with 4mm symmetry and carry four O(2-) anions as well as four primary Br(-) anions, yielding a coordination number of 8. While the Br(-) anions exhibit the same site symmetry as the Pr(3+) cations, the oxide anions are located at the Wyckoff position 2a with site symmetry [Formula: see text]m2 and have four Pr(3+) cations as neighbours, defining a tetra-hedron.

  19. Ultraviolet quantum detection efficiency of potassium bromide as an opaque photocathode applied to microchannel plates

    NASA Technical Reports Server (NTRS)

    Siegmund, Oswald H. W.; Everman, E.; Vallerga, J. V.; Sokolowski, J.; Lampton, M.

    1987-01-01

    The quantum detection efficiency (QDE) of potassium bromide as a photocathode applied directly to the surface of a microchannel plate over the 250-1600 A wavelength range has been measured. The contributions of the photocathode material in the channels and on the interchannel web to the QDE have been determined. Two broad peaks in the QDE centered at about 450 and about 1050 A are apparent, the former with about 50 percent peak QDE and the latter with about 40 percent peak QDE. The photoelectric threshold is observed at about 1600 A, and there is a narrow QDE minimum at about 750 A which correlates with 2X the band gap energy for KBr. The angular variation of the QDE from 0 to 40 deg to the channnel axis has also been examined. The stability of Kbr with time is shown to be good with no significant degradation of QDE at wavelengths below 1216 A over a 15-day period in air.

  20. Adsorption layer properties of alkyltrimethylammonium bromides at interfaces between water and different alkanes.

    PubMed

    Mucic, N; Kovalchuk, N M; Aksenenko, E V; Fainerman, V B; Miller, R

    2013-11-15

    We measured the interfacial tensions of aqueous solutions against different oil phases using drop profile analysis tensiometry (PAT-1, Sinterface Technologies, Germany) for decyl- and dodecyltrimethylammonium bromide (C10TAB and C12TAB) in phosphate buffer (10 mM, pH7). The following alkanes were used as oil phases: hexane, heptane, octane, nonane, decane, dodecane and tetradecane. The obtained equilibrium interfacial tension isotherms were fitted by the Frumkin Ionic Compressibility model (FIC). The surfactants adsorb at the water/oil interface in competition with the oil molecules. At high surfactant surface coverage this competitive adsorption is manifested in two ways. First, for short chain surfactants, the oil molecules are embedded into the adsorption layer. Second, for long chain surfactants, the short alkane chains of the oil molecules are squeezed out from the adsorption layer due to strong mutual interaction between surfactants' chains. PMID:24011787

  1. Viscosities of cetylpyridinium bromide solutions (aqueous and aqueous KBr) in the presence of alcohols and amines

    SciTech Connect

    David, S.L.; Kumar, S.; Kabir-ud-Din

    1997-01-01

    Among the large number of additives, alcohols hold a special place, being by far the most common cosurfactants which are added to surfactant-oil combinations to generate microemulsions. Though the studies using amines as cosurfactant in microemulsions are few, it has been proved that they are also potential candidates for such formulations. The effect of organic additives (aliphatic/aromatic amines or alcohols) on the viscosities of aqueous and 0.1 M KBr solutions of 0.05 or 0.1 M cetylpyridinium bromide have been measured under Newtonian flow conditions. The viscosity changed dramatically in the presence of KBr. This is explained by the favorable conditions produced by the salt which assists the micellar growth by organic additives with a concomitant enhancement in viscosity. Reasons for the effectiveness of these additives are suggested. The causes of the viscosity decrease at higher concentrations of the additive are also explained.

  2. The plant alkaloid piperine as a potential inhibitor of ethidium bromide efflux in Mycobacterium smegmatis.

    PubMed

    Jin, Jing; Zhang, Jiyu; Guo, Na; Feng, Haihua; Li, Lei; Liang, Junchao; Sun, Kai; Wu, Xiuping; Wang, Xuelin; Liu, Mingyuan; Deng, Xuming; Yu, Lu

    2011-02-01

    Piperine, a major plant alkaloid found in black pepper (Piper nigrum) and long pepper (Piper longum), has shown potential for inhibiting the efflux pump (EP) of Staphylococcus aureus. In this study, a modulation assay showed that piperine could decrease the MIC of ethidium bromide (EtBr) twofold at 32 μg ml(-1) and fourfold at 64 μg ml(-1) against Mycobacterium smegmatis mc(2) 155 ATCC 700084. A real-time, 96-well plate fluorometric method was employed to evaluate the EP inhibition ability of piperine in M. smegmatis. Reserpine, chlorpromazine, verapamil and carbonyl cyanide m-chlorophenylhydrazone were used as positive controls. Piperine significantly enhanced accumulation and decreased the efflux of EtBr in M. smegmatis, which suggests that it has the ability to inhibit mycobacterial EPs.

  3. Carbon nanotubes as an efficient hole collector for high voltage methylammonium lead bromide perovskite solar cells.

    PubMed

    Li, Zhen; Boix, Pablo P; Xing, Guichuan; Fu, Kunwu; Kulkarni, Sneha A; Batabyal, Sudip K; Xu, Wenjing; Cao, Anyuan; Sum, Tze Chien; Mathews, Nripan; Wong, Lydia Helena

    2016-03-28

    A high open circuit voltage (V(OC)) close to 1.4 V under AM 1.5, 100 mW cm(-2) conditions is achieved when carbon nanotubes (CNTs) are used as a hole conductor in methyl ammonium lead bromide (MAPbBr3) perovskite solar cells. Time-resolved photoluminescence and impedance spectroscopy investigations suggest that the observed high V(OC) is a result of the better charge extraction and lower recombination of the CNT hole conductor. Tandem solar cells with all perovskite absorbers are demonstrated with a MAPbBr3/CNT top cell and a MAPbI3 bottom cell, achieving a V(OC) of 2.24 V in series connection. The semitransparent and high voltage MAPbBr3/CNT solar cells show great potential for applications in solar cell windows, tandem solar cells and solar driven water splitting.

  4. Tetrabutylammonium bromide (TBABr)-based deep eutectic solvents (DESs) and their physical properties.

    PubMed

    Yusof, Rizana; Abdulmalek, Emilia; Sirat, Kamaliah; Rahman, Mohd Basyaruddin Abdul

    2014-06-13

    Density, viscosity and ionic conductivity data sets of deep eutectic solvents (DESs) formed by tetrabutylammonium bromide (TBABr) paired with ethlyene glycol, 1,3-propanediol, 1,5-pentanediol and glycerol hydrogen bond donors (HBDs) are reported. The properties of DES were measured at temperatures between 303 K and 333 K for HBD percentages of 66.7% to 90%. The effects of HBDs under different temperature and percentages are systematically analyzed. As expected, the measured density and viscosity of the studied DESs decreased with an increase in temperature, while ionic conductivity increases with temperature. In general, DESs made of TBABr and glycerol showed the highest density and viscosity and the lowest ionic conductivity when compared to other DESs. The presence of an extra hydroxyl group on glycerol in a DES affected the properties of the DES.

  5. Strain IMB-1, a novel bacterium for the removal of methyl bromide in fumigated agricultural soils

    USGS Publications Warehouse

    Connell, Hancock T.L.; Costello, A.M.; Lidstrom, M.E.; Oremland, R.S.

    1998-01-01

    A facultatively methylotrophic bacterium, strain IMB-1, that has been isolated from agricultural soil grows on methyl bromide (MeBr), methyl iodide, methyl chloride, and methylated amines, as well as on glucose, pyruvate, or acetate. Phylogenetic analysis of its 16S rRNA gene sequence indicates that strain IMB-1 classes in the alpha subgroup of the class Proteobacteria and is closely related to members of the genus Rhizobium. The ability of strain IMB-1 to oxidize MeBr to CO2 is constitutive in cells regardless of the growth substrate. Addition of cell suspensions of strain IMB-1 to soils greatly accelerates the oxidation of MeBr, as does pretreatment of soils with low concentrations of methyl iodide. These results suggest that soil treatment strategies can be devised whereby bacteria can effectively consume MeBr during field fumigations, which would diminish or eliminate the outward flux of MeBr to the atmosphere.

  6. Computational study of dissociative electron attachment to π-allyl ruthenium (II) tricarbonyl bromide

    NASA Astrophysics Data System (ADS)

    Thorman, Rachel M.; Bjornsson, Ragnar; Ingólfsson, Oddur

    2016-08-01

    Motivated by the current interest in low energy electron induced fragmentation of organometallic complexes in focused electron beam induced deposition (FEBID) we have evaluated different theoretical protocols for the calculation of thermochemical threshold energies for DEA to the organometallic complex π-allyl ruthenium (II) tricarbonyl bromide. Several different computational methods including density functional theory (DFT), hybrid-DFT and coupled cluster were evaluated for their ability to predict these threshold energies and compared with the respective experimental values. Density functional theory and hybrid DFT methods were surprisingly found to have poor reliability in the modelling of several DEA reactions; however, the coupled cluster method LPNO-pCCSD/2a was found to produce much more accurate results. Using the local correlation pair natural orbital (LPNO) methodology, high level coupled cluster calculations for open-shell systems of this size are now affordable, paving the way for reliable theoretical DEA predictions of such compounds.

  7. Role of combined indacaterol and glycopyrronium bromide (QVA149) for the treatment of COPD in Japan.

    PubMed

    Horita, Nobuyuki; Kaneko, Takeshi

    2015-01-01

    Once-daily dual-bronchodilator therapy with combined indacaterol and glycopyrronium bromide in one device (Ultibro, Breezhaler), often called QVA149, was first approved in 2013 in Japan and Europe. As of November 2014, more than 40 countries had approved this medication except for the USA. This is the first dual bronchodilator in one device. Now, the Breezhaler is the only device that can provide long-acting muscarinic antagonist (glycopyrronium bromide), long-acting beta agonist (indacaterol), and a combination of the two medications (QVA149). The choice among the three medications allows a patient to use the same inhalation device even when the regimen is changed from single-bronchodilator therapy to dual-bronchodilator therapy. In addition, the quick bronchodilation effect and once-daily administration can improve patient adherence to medical treatment for chronic obstructive pulmonary disease (COPD). To our knowledge, as of November 2014, the safety and the efficacy of QVA149 have been evaluated in 14 randomized controlled trials. The 14 trials generally showed good safety profiles, and there were better or not-inferior bronchodilator effects of QVA149 when compared with placebo, or other inhaled medication. According to the Japanese Respiratory Society guidelines, QVA149 is a combination of the two first-line bronchodilators. Our meta-analysis indicated that QVA149 is superior to the salmeterol-fluticasone combination to treat COPD in respect of the frequency of adverse effects, exacerbation, pneumonia, and improvement of trough forced expiratory volume in 1 second (FEV1). Thus, we believe that QVA149 can be a key medication for COPD treatments. PMID:25960646

  8. The aqueous catanionic system sodium perfluorooctanoate-dodecyltrimethylammonium bromide at low concentration.

    PubMed

    López-Fontán, José Luis; Blanco, Elena; Ruso, Juan M; Prieto, Gerardo; Schulz, Pablo C; Sarmiento, Félix

    2007-08-15

    The interaction between sodium perfluorooctanoate (SPFO) and dodecyltrimethylammonium bromide (DTAB) was studied by several methods and it was found strongly synergistic. Above a mole fraction of SPFO in the surfactant mixture (alpha(SPFO))=0.38, the interaction is repulsive and increases with the content of SPFO in both, the overall mixture and micelles, whereas the interaction is attractive if DTAB is in excess. At alpha(SPFO)=0.38 the low miscibility between hydrocarbon and fluorocarbon is counterbalanced by the electrostatic attraction between the opposite charged head groups, and the micelle composition is ideal (i.e., the mole fraction of SPFO in micelles X(SPFO)=alpha(SPFO)=0.38). The solubility of fluorocarbon in hydrocarbon is lower than that of hydrocarbon in fluorocarbon. Micelles of DTAB act as a solvent for SPFO without important structural changes, whilst micelles of SPFO undergo important changes when dissolve DTAB. This asymmetry may be interpreted as caused by the difference in chain length that favors the inclusion of the shorter chain in micelles of the longer surfactant, but disfavors the opposite process. Above X(SPFO)=0.5 there is an excess adsorption of bromide ions on the mixed micelles surface, giving rise to a high zeta potential. Micelles of pure SPFO or pure DTAB show an important energy barrier which prevents micelle flocculation. The inclusion of SPFO in DTAB micelles produces a reduction of the energy barrier, which disappeared when alpha(SPFO)=0.5. This produces the flocculation of micelles giving rise to the formation of a non-birefringent coacervate, which is probably formed by unordered isometric clusters of micelles.

  9. Carbon nanotubes as an efficient hole collector for high voltage methylammonium lead bromide perovskite solar cells

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Boix, Pablo P.; Xing, Guichuan; Fu, Kunwu; Kulkarni, Sneha A.; Batabyal, Sudip K.; Xu, Wenjing; Cao, Anyuan; Sum, Tze Chien; Mathews, Nripan; Wong, Lydia Helena

    2016-03-01

    A high open circuit voltage (VOC) close to 1.4 V under AM 1.5, 100 mW cm-2 conditions is achieved when carbon nanotubes (CNTs) are used as a hole conductor in methyl ammonium lead bromide (MAPbBr3) perovskite solar cells. Time-resolved photoluminescence and impedance spectroscopy investigations suggest that the observed high VOC is a result of the better charge extraction and lower recombination of the CNT hole conductor. Tandem solar cells with all perovskite absorbers are demonstrated with a MAPbBr3/CNT top cell and a MAPbI3 bottom cell, achieving a VOC of 2.24 V in series connection. The semitransparent and high voltage MAPbBr3/CNT solar cells show great potential for applications in solar cell windows, tandem solar cells and solar driven water splitting.A high open circuit voltage (VOC) close to 1.4 V under AM 1.5, 100 mW cm-2 conditions is achieved when carbon nanotubes (CNTs) are used as a hole conductor in methyl ammonium lead bromide (MAPbBr3) perovskite solar cells. Time-resolved photoluminescence and impedance spectroscopy investigations suggest that the observed high VOC is a result of the better charge extraction and lower recombination of the CNT hole conductor. Tandem solar cells with all perovskite absorbers are demonstrated with a MAPbBr3/CNT top cell and a MAPbI3 bottom cell, achieving a VOC of 2.24 V in series connection. The semitransparent and high voltage MAPbBr3/CNT solar cells show great potential for applications in solar cell windows, tandem solar cells and solar driven water splitting. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06177f

  10. Multimetallic catalysed cross-coupling of aryl bromides with aryl triflates

    NASA Astrophysics Data System (ADS)

    Ackerman, Laura K. G.; Lovell, Matthew M.; Weix, Daniel J.

    2015-08-01

    The advent of transition-metal catalysed strategies for forming new carbon-carbon bonds has revolutionized the field of organic chemistry, enabling the efficient synthesis of ligands, materials, and biologically active molecules. In cases where a single metal fails to promote a selective or efficient transformation, the synergistic cooperation of two distinct catalysts--multimetallic catalysis--can be used instead. Many important reactions rely on multimetallic catalysis, such as the Wacker oxidation of olefins and the Sonogashira coupling of alkynes with aryl halides, but this approach has largely been limited to the use of metals with distinct reactivities, with only one metal catalyst undergoing oxidative addition. Here, we demonstrate that cooperativity between two group 10 metal catalysts--(bipyridine)nickel and (1,3-bis(diphenylphosphino)propane)palladium--enables a general cross-Ullmann reaction (the cross-coupling of two different aryl electrophiles). Our method couples aryl bromides with aryl triflates directly, eliminating the use of arylmetal reagents and avoiding the challenge of differentiating between multiple carbon-hydrogen bonds that is required for direct arylation methods. Selectivity can be achieved without an excess of either substrate and originates from the orthogonal reactivity of the two catalysts and the relative stability of the two arylmetal intermediates. While (1,3-bis(diphenylphosphino)propane)palladium reacts preferentially with aryl triflates to afford a persistent intermediate, (bipyridine)nickel reacts preferentially with aryl bromides to form a transient, reactive intermediate. Although each catalyst forms less than 5 per cent cross-coupled product in isolation, together they are able to achieve a yield of up to 94 per cent. Our results reveal a new method for the synthesis of biaryls, heteroaryls, and dienes, as well as a general mechanism for the selective transfer of ligands between two metal catalysts. We anticipate that this

  11. High-resolution slice imaging of quantum state-to-state photodissociation of methyl bromide

    SciTech Connect

    Lipciuc, M. Laura; Janssen, Maurice H. M.

    2007-12-14

    The photodissociation of rotationally state-selected methyl bromide is studied in the wavelength region between 213 and 235 nm using slice imaging. A hexapole state selector is used to focus a single (JK=11) rotational quantum state of the parent molecule, and a high speed slice imaging detector measures directly the three-dimensional recoil distribution of the methyl fragment. Experiments were performed on both normal (CH{sub 3}Br) and deuterated (CD{sub 3}Br) parent molecules. The velocity distribution of the methyl fragment shows a rich structure, especially for the CD{sub 3} photofragment, assigned to the formation of vibrationally excited methyl fragments in the {nu}{sub 1} and {nu}{sub 4} vibrational modes. The CH{sub 3} fragment formed with ground state Br({sup 2}P{sub 3/2}) is observed to be rotationally more excited, by some 230-340 cm{sup -1}, compared to the methyl fragment formed with spin-orbit excited Br({sup 2}P{sub 1/2}). Branching ratios and angular distributions are obtained for various methyl product states and they are observed to vary with photodissociation energy. The nonadiabatic transition probability for the {sup 3}Q{sub 0+}{yields}{sup 1}Q{sub 1} transition is calculated from the images and differences between the isotopes are observed. Comparison with previous non-state-selected experiments indicates an enhanced nonadiabatic transition probability for state-selected K=1 methyl bromide parent molecules. From the state-to-state photodissociation experiments the dissociationenergy for both isotopes was determined, D{sub 0}(CH{sub 3}Br)=23 400{+-}133 cm{sup -1} and D{sub 0}(CD{sub 3}Br)=23 827{+-}94 cm{sup -1}.

  12. Development of SPME method for concomitant sample preparation of rocuronium bromide and tranexamic acid in plasma.

    PubMed

    Gorynski, Krzysztof; Bojko, Barbara; Kluger, Michael; Jerath, Angela; Wąsowicz, Marcin; Pawliszyn, Janusz

    2014-04-01

    A high-throughput method using solid-phase microextraction coupled to liquid chromatography-tandem mass spectrometry (SPME-LC-MS/MS) for determination of tranexamic acid and rocuronium bromide in human plasma was developed and validated. Standard analytical approaches employ acidification of the sample due to the instability of rocuronium bromide in collected plasma samples. However, acidification affects the binding equilibrium of the drug and consequently no information on the free/bound concentration can be obtained. Contrary to these protocols, the proposed method requires minimum sample handling and no ion pairing and/or derivatization procedure. A weak cation exchange coating was chosen as the best extracting phase for selected drugs, guaranteed a good recovery, minimum carry-over, reusability and reproducibility. SPME procedure met all Food and Drug Administration acceptance criteria for bioanalytical assays at three concentration levels, for both selected drugs. Post-extraction addition experiments showed that matrix effect was less than ±3%. Here, a weak cation exchange thin-film solid-phase microextraction (WCX TF-SPME) approach is presented, offering effective cleanup procedure and full quantitation of the drugs in plasma, undoubtedly one the most challenging matrices with regards to its complexity. In addition, the 96-well plate format of WCX TF-SPME system provides considerable advantages, such as high throughput analysis for up to 96 samples in 35min (22s/sample), requirement of small amounts of plasma samples (0.8mL), and a simple sample preparation protocol, all of which shows a promise for possible on-site application in hospitals to monitor concentrations of the drugs in close to real time. PMID:24525565

  13. Efficacy of Methyl Bromide for Control of Different Life Stages of Stored-Product Psocids.

    PubMed

    Athanassiou, Christos G; Hasan, M Mahbub; Phillips, Thomas W; Aikins, M Jamie; Throne, James E

    2015-06-01

    The psocid species Liposcelis paeta Pearman, Liposcelis entomophila (Enderlein), Liposcelis decolor (Pearman), Liposcelis bostrychophila Badonnel (Psocoptera: Liposcelididae), and Lepinotus reticulatus Enderlein (Psocoptera: Trogiidae) were evaluated in laboratory bioassays to determine their susceptibility to six concentrations of methyl bromide (0.027, 0.113, 0.280, 0.393, 0.452, and 0.616 g/m3) after 48 h of exposure at 27.5°C. The life stages that were evaluated were adults (for all species), nymphs (for all species except Lep. reticulatus), and eggs (for L. entomophila, L. decolor, and L. bostrychophila). Adults and nymphs were very susceptible, and complete mortality was recorded at concentrations between 0.027 and 0.280 g/m3. In contrast, eggs were by far more tolerant than adults and nymphs for all species tested. At 0.027 g/m3, mortality did not exceed 53%, while survival was high even at 0.113 g/m3. Complete (100%) egg mortality was recorded at 0.393 g/m3 for L. decolor and at 0.452 g/m3 for L. entomophila and L. bostrychophila; concentrations estimated to give 99% mortality for eggs of these three species were 0.710, 1.044, and 0.891 g/m3, respectively. These results show that stored-product psocids are susceptible to methyl bromide, but concentrations of ≥0.452 g/m3 should be used to control all life stages. PMID:26470271

  14. Antiestrogenic activity and related disinfection by-product formation induced by bromide during chlorine disinfection of sewage secondary effluent.

    PubMed

    Wu, Qian-Yuan; Tang, Xin; Huang, Huang; Li, Yi; Hu, Hong-Ying; Ding, Ya-Nan; Shao, Yi-Ru

    2014-05-30

    Chlorine disinfection, widely used in wastewater reclamation, can form toxic and harmful disinfection by-products (DBPs), some of which are associated with endocrine disruption. In this study, the presence of bromide was found to promote an increase in antiestrogenic activity using a yeast two-hybrid assay in the sewage secondary effluent during chlorine disinfection. Among the dissolved organic matters in the secondary effluent, hydrophobic acids and hydrophilic substance fractions were determined as potential precursors associated with increase in antiestrogenic activity in the secondary effluent induced by bromide. Further antiestrogenic activity evaluation and mass spectrum characterization following the semipreparative liquid chromatography fractionation of a natural organic matter precursor, tyrosine, after chlorination under the presence of bromide revealed, for the first time, that 2-(bromo-4-hydroxyphenyl) acetonitrile (Br-HPAN) and 2-(dibromo-4-hydroxyphenyl) acetonitrile (DBr-HPAN) exhibited antiestrogenic activity. Br-HPAN and DBr-HPAN were the DBPs involved in the increase in antiestrogenic activity in the tyrosine solution. Bromide was shown to induce the formation of Br-HPAN and DBr-HPAN in the secondary effluent during chlorine disinfection.

  15. Formation of halogenated organic byproducts during medium-pressure UV and chlorine coexposure of model compounds, NOM and bromide.

    PubMed

    Zhao, Quan; Shang, Chii; Zhang, Xiangru; Ding, Guoyu; Yang, Xin

    2011-12-01

    When chlorine is applied before or during UV disinfection of bromide-containing water, interactions between chlorine, bromide and UV light are inevitable. Formation of halogenated organic byproducts was studied during medium-pressure UV (MPUV) and chlorine coexposure of phenol, nitrobenzene and benzoic acid and maleic acid, chosen to represent electron-donating aromatics, electron-withdrawing aromatics, and aliphatic structures in natural organic matter (NOM), respectively. All were evaluated in the presence and absence of bromide. MPUV and chlorine coexposure of phenol produced less total organic halogen (TOX, a collective parameter for halogenated organic byproducts) than chlorination in the dark, and more haloacetic acids instead of halophenols. Increases in TOX were found in the coexposure of nitrobenzene and benzoic acid, but maleic acid was rather inert during coexposure. The presence of bromide increased the formation of brominated TOX but did not significantly affect total TOX formation, in spite of the fact that it reduced hydroxyl radical levels. MPUV and chlorine coexposure of NOM gave a higher differential UV absorbance of NOM and a larger shift to lower molecular weight compounds than chlorination in the dark. However, TOX formation with NOM remained similar to that observed from dark chlorination.

  16. 78 FR 14508 - Notice of Affirmation of Addition of a Treatment Schedule for Methyl Bromide Fumigation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-06

    ... Manual of the treatment described in the notice published at 77 FR 31564-31566 on May 29, 2012. FOR.... 305.3(b), we published a notice \\2\\ in the Federal Register on May 29, 2012 (77 FR 31564-31566, Docket... methyl bromide fumigation of cottonseed for the fungal plant pathogen Fusarium oxysporum f....

  17. Understanding the Impact of Bromide on the Photovoltaic Performance of CH3 NH3 PbI3 Solar Cells.

    PubMed

    Ibrahim Dar, M; Abdi-Jalebi, Mojtaba; Arora, Neha; Moehl, Thomas; Grätzel, Michael; Nazeeruddin, Mohammad Khaja

    2015-11-25

    An optimum amount of lead bromide (1%) can enhance the power conversion efficiency of CH3 NH3 PbI3-x Brx (where x ≈ 0) devices from 14.7% to 16.9% without altering the bandgap of the perovskite material.

  18. Optimizing postharvest methyl bromide treatments to control spotted wing drosophila, Drosophila suzukii, in sweet cherries from Western USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide (MB) chamber fumigations were evaluated for postharvest control of spotted wing drosophila (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), in fresh sweet cherry exports from Western USA. Sweet cherries were infested with SWD, incubated to maximize numbers of the most M...

  19. 40 CFR 721.10115 - 1-Hexadecanaminium, N,N-dibutyl-N-(2-hydroxyethyl)-, bromide (1:1).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false 1-Hexadecanaminium, N,N-dibutyl-N-(2... New Uses for Specific Chemical Substances § 721.10115 1-Hexadecanaminium, N,N-dibutyl-N-(2... chemical substance identified as 1-hexadecanaminium, N,N-dibutyl-N-(2-hydroxyethyl)-, bromide (1:1) (PMN...

  20. 40 CFR 721.10115 - 1-Hexadecanaminium, N,N-dibutyl-N-(2-hydroxyethyl)-, bromide (1:1).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false 1-Hexadecanaminium, N,N-dibutyl-N-(2... New Uses for Specific Chemical Substances § 721.10115 1-Hexadecanaminium, N,N-dibutyl-N-(2... chemical substance identified as 1-hexadecanaminium, N,N-dibutyl-N-(2-hydroxyethyl)-, bromide (1:1) (PMN...

  1. Aerosols and contact insecticides as alternatives to methyl bromide in flour mills, food production facilities, and food warehouses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fumigant methyl bromide (MB) is being phased out of production and usage to control stored product insects in flour and rice mills, as well as feed and food production plants, in the United States (US) and other developed countries throughout the world. A phase-out schedule has also been establi...

  2. Impact of bromide on halogen incorporation into organic moieties in chlorinated drinking water treatment and distribution systems.

    PubMed

    Tan, J; Allard, S; Gruchlik, Y; McDonald, S; Joll, C A; Heitz, A

    2016-01-15

    The impact of elevated bromide concentrations (399 to 750 μg/L) on the formation of halogenated disinfection by-products (DBPs), namely trihalomethanes, haloacetic acids, haloacetonitriles, and adsorbable organic halogen (AOX), in two drinking water systems was investigated. Bromine was the main halogen incorporated into all of the DBP classes and into organic carbon, even though chlorine was present in large excess to maintain a disinfectant residual. Due to the higher reactivity of bromine compared to chlorine, brominated DBPs were rapidly formed, followed by a slower increase in chlorinated DBPs. Higher bromine substitution and incorporation factors for individual DBP classes were observed for the chlorinated water from the groundwater source (lower concentration of dissolved organic carbon (DOC)), which contained a higher concentration of bromide, than for the surface water source (higher DOC). The molar distribution of adsorbable organic bromine to chlorine (AOBr/AOCl) for AOX in the groundwater distribution system was 1.5:1 and almost 1:1 for the surface water system. The measured (regulated) DBPs only accounted for 16 to 33% of the total organic halogen, demonstrating that AOX measurements are essential to provide a full understanding of the formation of halogenated DBPs in drinking waters. In addition, the study demonstrated that a significant proportion (up to 94%) of the bromide in source waters can be converted AOBr. An evaluation of AOBr and AOCl through a second groundwater treatment plant that uses conventional treatment processes for DOC removal produced 70% of AOX as AOBr, with 69% of the initial source water bromide converted to AOBr. Exposure to organobromine compounds is suspected to result in greater adverse health consequences than their chlorinated analogues. Therefore, this study highlights the need for improved methods to selectively reduce the bromide content in source waters.

  3. The Comparative Evaluation of Antibacterial Activity of Methacryloxydodecyl Pyridinium Bromide and Non-methacryloxydodecyl Pyridinium Bromide Dentin Bonding Systems Using Two Different Techniques: An In vitro Study

    PubMed Central

    Deshpande, Prashanth; Nainan, Mohan Thomas; Metta, Kiran Kumar; Shivanna, Vasundhara; Ravi, Ramkrishna; Prashanth, B R

    2014-01-01

    zones (P > 0.05), but the bonding resin of CPB did not produce any inhibition. When tested by the tooth cavity model technique, the application of CPB resulted in significantly less bacterial recovery than the PBNT (P < 0.05), demonstrating substantial antibacterial effects. Conclusion: The CPB that employs the antibacterial primer containing methacryloxydodecyl pyridinium bromide, was effective in inactivating the bacteria in the cavity compared to little antibacterial activity shown by PBNT. The tooth cavity mode test used in the present study is a reliable method to evaluate the antibacterial effects of dentin bonding agents simulating clinical situations. PMID:25395795

  4. Multimetallic Catalysis Enabled Cross-Coupling of Aryl Bromides with Aryl Triflates

    PubMed Central

    Ackerman, Laura K.G.; Lovell, Matthew M.

    2015-01-01

    Transition metal-catalyzed strategies for the formation of new C-C bonds have revolutionized the field of organic chemistry, enabling the efficient synthesis of ligands, materials, and biologically active molecules.1–3 In cases where a single metal fails to promote a selective or efficient transformation, the synergistic cooperation4 of two distinct catalysts – multimetallic catalysis – can be employed instead. Many important reactions rely on multimetallic catalysis,5 including the Wacker oxidation of olefins6–8 and the Sonogashira coupling of alkynes with aryl halides.9–10 However, the application of this strategy, even in recently developed methods11, has largely been limited to the use of metals with distinct reactivities, with only one metal catalyst undergoing an oxidative addition.12 In this manuscript, we demonstrate that cooperativity between two d10 metal catalysts, (bipyridine)nickel and (1,3-bis(diphenylphosphino)propane)palladium, enables a general cross-Ullman reaction.13–15 Our method couples aryl bromides with aryl triflates directly, eliminating the use of arylmetal reagents and avoiding the challenge of differentiating between multiple C–H bonds that is required for many C–H activation methods.16–17 The selectivity does not require an excess of either substrate and originates from the orthogonal activity of the two catalysts and the relative stability of the two arylmetal intermediates. While (dppp)Pd reacts preferentially with aryl triflates to afford a persistent intermediate, (bpy)Ni reacts preferentially with aryl bromides to form a transient, reactive intermediate. Although each catalyst forms less than 5% cross product in isolation, together they are able to achieve up to 94% yield. Our results reveal a new, general method for the synthesis of biaryls, heteroaryls, and dienes, as well as a new mechanism for selective transmetalation between two catalysts. We anticipate that this reaction will simplify the synthesis of

  5. Safety and pharmacokinetics of multiple doses of aclidinium bromide administered twice daily in healthy volunteers.

    PubMed

    Lasseter, K; Dilzer, S; Jansat, J M; Garcia Gil, E; Caracta, C F; Ortiz, S

    2012-04-01

    Chronic obstructive pulmonary disease (COPD) is characterized by progressive airway obstruction and increased cholinergic tone. The global initiative for chronic obstructive lung disease (GOLD) guidelines recommend long-acting anticholinergics for COPD maintenance treatment. Aclidinium bromide is a novel, long-acting muscarinic antagonist developed for the treatment of COPD. A phase I, randomized, single-blind, multiple-dose clinical trial was conducted to assess the safety and pharmacokinetics (PK) of multiple doses of twice-daily (BID) aclidinium in healthy subjects. Thirty healthy male and female subjects received aclidinium 200 μg, 400 μg, 800 μg, or placebo twice daily for 7 days. Subjects were randomized to 1 of 3 cohorts and 10 subjects in each cohort were randomized (8:2) to either aclidinium or placebo groups. Safety was assessed via adverse events (AEs), laboratory evaluations, vital signs, and ECGs. Plasma samples were obtained at multiple time points throughout the study and analyzed for aclidinium and its inactive acid and alcohol metabolites using a fully validated method of liquid chromatography coupled with tandem mass spectrometry. A total of 9 treatment-emergent AEs were reported (1, placebo; 3, aclidinium 400 μg; 5, aclidinium 800 μg), all of which were mild in severity. No serious AEs were reported. There were no clinically meaningful changes in laboratory parameters or vital signs. PK parameters on Day 7 following BID dosing of aclidinium showed that steady state was achieved for aclidinium and its metabolites. On Days 1 and 7, maximum plasma concentrations (Cmax) of aclidinium were generally observed at the first PK time point (5 min postdose) and rapidly declined, with plasma concentrations generally less than 10% of Cmax by 6 h postdose in all aclidinium groups. Mean effective t(½) after the evening dose on Day 7 ranged from 4.6 to 7.0 h for aclidinium 400 μg and 800 μg, similar to the terminal t(½) observed on Day 1 (4.5-5.9 h

  6. Transport of Alachlor, Atrazine, Dicamba, and Bromide through Silt and Loam Soils

    NASA Astrophysics Data System (ADS)

    Tindall, J. A.

    2015-12-01

    The herbicides alachlor, atrazine, and dicamba, as well as bromide were applied to soils overlying the High Plains aquifer in Nebraska, to both macropore and non-macropore sites. Three of 6 study areas (exhibiting a high percentage of macropores) were used for analysis of chemical transport. Twelve intact soil cores (30 cm diameter; 40 cm height), were excavated (two each from 0-40 cm and 40-80 cm depths). The first three study areas and soil cores were used to study preferential flow characteristics using dye staining and to determine hydraulic properties; the remaining cores were treated the same as field macropore sites. Two undisturbed experimental field plots, each with a 1 m2 surface area, were established in each of the three macropore study areas. Each preferential plot was instrumented with suction lysimeters, tensiometers, and neutron access tubes - 10 cm increments to 80 cm - and planted in corn. Three study areas that did not exhibit macropores had alachlor, atrazine, and dicamba and bromide disked into the top 15 cm of soil; concentrations were tracked for 120 days - samples were collected on a grid, distributed within 3 plots measuring 50 m x 50 m each. Core samples were collected prior to and immediately after application, and then at 30, 60, and 120 days after application. Each lab core sample was in 15-cm lengths from 0-15 cm, 15-30 cm, 45-60 cm, and 75-90 cm. For areas exhibiting macropores, herbicides had begun to move between 10-15 days after application with concentrations peaking at various depths after heavy rainfall events. Field lysimeter samples showed increases in concentrations of herbicides at depths where laboratory data indicated greater percentages of preferential flowpaths. Concentrations of atrazine, alachlor and dicamba exceeding 0.30, 0.30, and 0.05 μg m1-1 respectively were observed with depth (10-30 cm and 50-70 cm) after two months following heavy rainfall events indicating that preferential flowpaths were a significant

  7. Advanced oxidation of bromide-containing drinking water: a balance between bromate and trihalomethane formation control.

    PubMed

    Wang, Yongjing; Yu, Jianwei; Han, Po; Sha, Jing; An, Tao; Li, Wei; Liu, Juan; Yang, Min

    2013-11-01

    Addition of H202 has been employed to repress bromate formation during ozonation of bromide-containing source water. However, the addition of H2O2 will change the oxidation pathways of organic compounds due to the generation of abundant hydroxyl radicals, which could affect the removal efficacy of trihalomethane precursors via the combination of ozone and biological activated carbon (O3-BAC). In this study, we evaluated the effects of H2O2 addition on bromate formation and trihalomethane formation potential (THMFP) reduction during treatment of bromide-containing (97.6-129.1 microg/L) source water by the O3-BAC process. At an ozone dose of 4.2 mg/L, an H2O2/O3 (g/g) ratio of over 1.0 was required to maintain the bromate concentration below 10.0 microg/L, while a much lower H2O2/O3 ratio was sufficient for a lower ozone dose. An H2O2/O3 (g/g) ratio below 0.3 should be avoided since the bromate concentration will increase with increasing H2O2 dose below this ratio. However, the addition of H202 at an ozone dose of 3.2 mg/L and an H2O2/O3 ratio of 1.0 resulted in a 43% decrease in THMFP removal when comparedwith the O3-BAC process. The optimum H2O2/O3 (g/g) ratio for balancing bromate and trihalomethane control was about 0.7-1.0. Fractionation of organic materials showed that the addition of H2O2 decreased the removal efficacy of the hydrophilic matter fraction of DOC by ozonation and increased the reactivity of the hydrophobic fractions during formation of trihalomethane, which may be the two main reasons responsible for the decrease in THMFP reduction efficacy. Overall, this study clearly demonstrated that it is necessary to balance bromate reduction and THMFP control when adopting an H2O2 addition strategy.

  8. Improved delivery of fenoterol plus ipratropium bromide using Respimat compared with a conventional metered dose inhaler.

    PubMed

    Goldberg, J; Freund, E; Beckers, B; Hinzmann, R

    2001-02-01

    Asthma can be effectively treated by the use of bronchodilator therapies administered by inhalation. The objective of this study was to describe the dose-response relationship of combined doses of fenoterol hydrobromide (F) and ipratropium bromide (I) (F/I) delivered via Respimat, a soft mist inhaler, and to establish the Respimat dose which is as efficacious and as safe as the standard marketed dose of F/I (100/40 microg) which is delivered via a conventional metered dose inhaler (MDI). In a double-blind (within device) cross-over study with a balanced incomplete block design, 62 patients with stable bronchial asthma (mean forced expiratory volume in one second (FEV1) 63% predicted) were randomized at five study centres to receive five out of eight possible treatments: placebo, F/I 12.5/5, 25/10, 50/20, 100/40 or 200/80 microg delivered via Respimat; F/I 50/20 or 100/40 microg delivered via MDI. Pulmonary function results were based on the per-protocol dataset, comprising 47 patients. All F/I doses produced greater increases in FEV1 than placebo. A log-linear dose-response was obtained for the average increase in FEV1 up to 6 h (AUC0-6 h) and peak FEV1 across the dose range administered by Respimat. Statistically, therapeutic equivalence was not demonstrated between any F/I dose administered by Respimat compared with the MDI. However 12.5/5 and 25/10 microg F/I administered via Respimat were closest (slightly superior) to the F/I dose of 100/40 microg delivered via MDI. Pharmacokinetic data from 34 patients indicated a two-fold greater systemic availability of both drugs following inhalation by Respimat compared to MDI. In general, the active treatments were well tolerated and safe with regard to vital signs, electrocardiography, laboratory parameters and adverse events. In conclusion, combined administration of fenoterol hydrobromide and ipratropium bromide via Respimat, is as effective and as safe as higher doses given via a metered dose inhaler. PMID:11334124

  9. One-Pot Three-Component Synthesis of Novel Diethyl((2-oxo-1,2-dihydroquinolin-3-yl)(arylamino)methyl)phosphonate as Potential Anticancer Agents.

    PubMed

    Fang, Yi-Lin; Wu, Zhi-Lin; Xiao, Meng-Wu; Tang, Yu-Ting; Li, Kang-Ming; Ye, Jiao; Xiang, Jian-Nan; Hu, Ai-Xi

    2016-01-01

    With the aim of discovering new anticancer agents, we have designed and synthesized novel α-aminophosphonate derivatives containing a 2-oxoquinoline structure using a convenient one-pot three-component method. The newly synthesized compounds were evaluated for antitumor activities against the A549 (human lung adenocarcinoma cell), HeLa (human cervical carcinoma cell), MCF-7 (human breast cancer cell), and U2OS (human osteosarcoma cell) cancer cell lines in vitro, employing a standard 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The results of pharmacological screening indicated that many compounds exhibited moderate to high levels of antitumor activities against the tested cancer cell lines and that most compounds showed more potent inhibitory activities comparable to 5-fluorouracil (5-FU) which was used as a positive control. The mechanism of representative compound 4u (diethyl((2-oxo-1,2-dihydroquinolin-3-yl)(phenyl-amino)methyl)phosphonate) indicated that the compound mainly arrested HeLa cells in S and G2 stages and was accompanied by apoptosis in HeLa cells. This action was confirmed by acridine orange/ethidium bromide staining, Hoechst 33342 staining, and flow cytometry. PMID:27136538

  10. Anticancer activity and DNA-binding properties of novel cationic Pt(II) complexes.

    PubMed

    Jamshidi, Mehrnaz; Yousefi, Reza; Nabavizadeh, Seyed Masoud; Rashidi, Mehdi; Haghighi, Mohsen Golbon; Niazi, Ali; Moosavi-Movahedi, Ali-Akbar

    2014-05-01

    In this study, three structurally related cationic Pt complexes, [Pt(ppy)(dppe)]CF3CO2: C1, [Pt(bhq)(dppe)]CF3CO2: C2, and [Pt(bhq)(dppf)]CF3CO2: C3, in which ppy=deprotonated 2-phenylpyridine, bhq=deprotonated benzo[h]quinoline, dppe=bis(diphenylphosphino)ethane and dppf=1,1'-bis(diphenylphosphino)ferrocene, were used for the assessment of their anticancer activities against Jurkat and MCF-7 cancer cell lines. The Pt complexes (C1-C3) demonstrated significant level of anticancer properties, as measured using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Moreover, the changes in nuclear morphology with Acridine Orange (AO) staining reveal that these complexes are capable to induce apoptosis, and only C1 stimulates activity of Caspase-3 in Jurkat cancer cells. To get a better insight into the nature of binding between these cationic Pt complexes and DNA, different spectroscopic techniques and gel electrophoresis were applied. On the basis of the results of UV/vis absorption spectroscopy, CD experiment and fluorescence quenching of ethidium bromide (EB)-DNA, the interaction between DNA and the Pt complexes is likely to occur through a mixed-binding mode. Overall, the present work suggests that a controlled modification could result in new potentially antitumor complexes which can survive the repair mechanism and induce facile apoptosis. PMID:24530367

  11. Probit analysis of comparative assays on toxicities of lead chloride and lead acetate to in vitro cultured human umbilical cord blood lymphocytes

    PubMed Central

    Patnaik, Rajashree

    2015-01-01

    This work describes that cytotoxicity of lead chloride and lead acetate to in vitro cultured lymphocytes from human umbilical cord blood, using four monitoring methods namely, trypan blue staining, acridine orange/ethidium bromide staining, 3-[4,5-dimethylthiazol-2-yl] 2,5-diphenyl tetrazolium bromide (MTT) and neutral red uptake assays; lead genotoxicity to lymphocytes was monitored by comet assay. The MIC value in each method was invariably 300 mg/L for PbCl2. Lethal concentration25 (LC25) values were almost in an agreeable range: 691.83 to 831.76 mg/L; LC50 values in each method were almost in the range: 1174.9 to 1348.9 mg/L; LC100 values were in the range: 3000 to 3300 mg/L, for lead chloride. Similarly, The MIC value in each method were invariably 150 mg/L; LC25 values were almost in the range: 295.12 to 371.53 mg/L; LC50 values were in the range: 501.18 to 588.84 mg/L; LC100 value was 1500 mg/L in all assays, for lead acetate. The comet assay also indicated that the LC100 values were 3300 mg/L lead chloride and 1500 mg/L lead acetate. Thus, both cytotoxicity and genotoxicity were recorded at 3300 mg/L lead chloride and 1500 mg/L lead acetate with lymphocytes. PMID:27486358

  12. One-Pot Three-Component Synthesis of Novel Diethyl((2-oxo-1,2-dihydroquinolin-3-yl)(arylamino)methyl)phosphonate as Potential Anticancer Agents

    PubMed Central

    Fang, Yi-Lin; Wu, Zhi-Lin; Xiao, Meng-Wu; Tang, Yu-Ting; Li, Kang-Ming; Ye, Jiao; Xiang, Jian-Nan; Hu, Ai-Xi

    2016-01-01

    With the aim of discovering new anticancer agents, we have designed and synthesized novel α-aminophosphonate derivatives containing a 2-oxoquinoline structure using a convenient one-pot three-component method. The newly synthesized compounds were evaluated for antitumor activities against the A549 (human lung adenocarcinoma cell), HeLa (human cervical carcinoma cell), MCF-7 (human breast cancer cell), and U2OS (human osteosarcoma cell) cancer cell lines in vitro, employing a standard 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The results of pharmacological screening indicated that many compounds exhibited moderate to high levels of antitumor activities against the tested cancer cell lines and that most compounds showed more potent inhibitory activities comparable to 5-fluorouracil (5-FU) which was used as a positive control. The mechanism of representative compound 4u (diethyl((2-oxo-1,2-dihydroquinolin-3-yl)(phenyl-amino)methyl)phosphonate) indicated that the compound mainly arrested HeLa cells in S and G2 stages and was accompanied by apoptosis in HeLa cells. This action was confirmed by acridine orange/ethidium bromide staining, Hoechst 33342 staining, and flow cytometry. PMID:27136538

  13. One-Pot Three-Component Synthesis of Novel Diethyl((2-oxo-1,2-dihydroquinolin-3-yl)(arylamino)methyl)phosphonate as Potential Anticancer Agents.

    PubMed

    Fang, Yi-Lin; Wu, Zhi-Lin; Xiao, Meng-Wu; Tang, Yu-Ting; Li, Kang-Ming; Ye, Jiao; Xiang, Jian-Nan; Hu, Ai-Xi

    2016-01-01

    With the aim of discovering new anticancer agents, we have designed and synthesized novel α-aminophosphonate derivatives containing a 2-oxoquinoline structure using a convenient one-pot three-component method. The newly synthesized compounds were evaluated for antitumor activities against the A549 (human lung adenocarcinoma cell), HeLa (human cervical carcinoma cell), MCF-7 (human breast cancer cell), and U2OS (human osteosarcoma cell) cancer cell lines in vitro, employing a standard 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. The results of pharmacological screening indicated that many compounds exhibited moderate to high levels of antitumor activities against the tested cancer cell lines and that most compounds showed more potent inhibitory activities comparable to 5-fluorouracil (5-FU) which was used as a positive control. The mechanism of representative compound 4u (diethyl((2-oxo-1,2-dihydroquinolin-3-yl)(phenyl-amino)methyl)phosphonate) indicated that the compound mainly arrested HeLa cells in S and G2 stages and was accompanied by apoptosis in HeLa cells. This action was confirmed by acridine orange/ethidium bromide staining, Hoechst 33342 staining, and flow cytometry.

  14. Influence of pyridostigmine bromide on human thermoregulation during cold-water immersion

    SciTech Connect

    Cadarette, B.S.; Prusaczyk, W.K.; Sawka, M.N. )

    1991-03-11

    This study examined the effects of an oral 30 mg dose of pyridostigmine bromide (PYR) on thermoregulatory and physiological responses during cold stress. Six men were immersed in chilled stirred water for up to 180 minutes; once 2 hours following ingestion of PYR and once 2 hours following ingestion of a placebo (CON). With PYR, mean ({plus minus} SD) red blood cell cholinesterase inhibition was 33 ({plus minus}12)% at 110 minutes post-ingestion. Cholinesterase inhibition was negatively related to lean body mass. Abdominal discomfort caused termination in 3 of 6 PYR experiments ({bar X} immersion time = 117 min) but in no CON experiments ({bar X} immersion time = 142 min, p > 0.05). During immersion, metabolic rate increased significantly over pre-immersion levels, and increased with duration of immersion, but did not differ between conditions. PYR had no significant effect on rectal temperature, mean body temperature, thermal sensation, heart rate, or plasma cortisol concentration. It was concluded that a 30 mg dose of PYR does not increase susceptibility to hypothermia in humans immersed in cold-water; however, in combination with cold-stress, PYR may result in marked abdominal cramping and limit cold tolerance.

  15. Dual bronchodilator therapy with aclidinium bromide/formoterol fumarate for chronic obstructive pulmonary disease.

    PubMed

    D'Urzo, Tony; Donohue, James F; Price, David; Miravitlles, Marc; Kerwin, Edward

    2015-10-01

    Inhaled bronchodilator therapy is a mainstay of treatment for chronic obstructive pulmonary disease (COPD). Despite the number and types of treatments available, the control of symptoms and exacerbations remains suboptimal, and adherence to, and persistence with, inhaled therapy is generally poor. Results from clinical studies suggest that dual bronchodilator therapy with long-acting muscarinic receptor antagonists (LAMAs) and long-acting β2 adrenergic receptor agonists (LABAs) may provide additional benefit over LAMA or LABA monotherapy without additive effects on safety and tolerability. Several combinations of a LAMA plus a LABA have recently become available in a single inhaler for maintenance therapy for adults with moderate-to-severe COPD, including aclidinium bromide/formoterol fumarate, glycopyrronium/indacaterol and umeclidinium/vilanterol. Here, we review clinical data demonstrating significant improvements in bronchodilation, 24-h symptoms, and health status with aclidinium/formoterol twice daily, and discuss how this treatment can be implemented in clinical practice as part of a patient-focused approach to disease control. PMID:26366803

  16. The Challenge of Research and Extension to Define and Implement Alternatives to Methyl Bromide

    PubMed Central

    Noling, J. W.; Becker, J. O.

    1994-01-01

    Over the past 30 years, methyl bromide (MBr), a broad spectrum fumigant, has been used extensively for soilborne disease and pest control in the production of many fruit, vegetable, turf, and nursery crops. Recently, agricultural emissions of MBr were implicated as a potentially significant contributor to stratospheric ozone depletion. As a precautionary measure for global ozone protection, the U.S. Environmental Protection Agency has enforced federal legislation which mandates a complete phase-out of MBr use within the United States by 1 January 2001. Thus, new cost effective, environmentally compatible strategies for control of nematodes and other soilborne pests and pathogens must be developed and tested in a relatively short time to avoid significant losses in crop productivity. The extent to which certain agricultural industries that are now heavily reliant on MBr are affected will depend on the development of sustainable, integrated tactics to pest control, such as combinations of cultural, chemical, and biological tactics. New muhidisciplinary research and extension programs must be developed to address and overcome major constraints and incompatibilities that have prevented such tactics from being widely adopted. PMID:19279928

  17. Interaction between Pluronic F127 and dioctadecyldimethylammonium bromide (DODAB) vesicles studied by differential scanning calorimetry.

    PubMed

    Feitosa, Eloi; Winnik, Françoise M

    2010-12-01

    A number of fundamental studies on the interactions between lipid bilayers and (ethylene oxide)-b-(propylene oxide)-b-(ethylene oxide) copolymers (PEO-PPO-PEO, Pluronics) have been carried out recently as model systems for the complex behavior of cell membranes with this class of polymers often employed in pharmaceutical formulations. We report here a study by differential scanning calorimetry (DSC) of the interactions in water between Pluronic F127 (F127), and the cationic vesicles of di-n-octadecyldimethylammonium bromide (DODAB), as a function of concentration of the two components (DODAB 0.1 and 1.0 mM; F127 0.1 to 5.0 mM) and of the sample preparation protocol. The DSC studies follow the critical micellization temperature (cmt ≈ 27 °C at 1.0 mM) of F127 and the gel-liquid crystal transition (T(m) ≈ 45 °C) of the DODAB bilayer and of F127/DODAB mixtures. Upon heating past T(m), vesicle/polymer mixtures undergo an irreversible conversion into mixed DODAB/F127 micelles and/or F127-bearing vesicles, depending on the relative amount of each component, together with, in some cases, residual intact F127 micelles or DODAB vesicles. Sample preparation protocol is shown to have little impact on the composition of mixed systems once they are heated above T(m).

  18. Application of cetyltrimethylammonium bromide bentonite-titanium dioxide photocatalysis technology for pretreatment of aging leachate.

    PubMed

    Cai, Fei-Fei; Yang, Zhao-Hui; Huang, Jing; Zeng, Guang-Ming; Wang, Li-Ke; Yang, Jian

    2014-06-30

    Organobentonite-photocatalysis technology was applied to pretreat aging leachate containing refractory pollutants. The organobentonite was synthesized by organic modifier cetyltrimethylammonium bromide (CTMAB) and natural bentonite. In characterization experiments, we could confirm that organic functional groups of cetyltrimethylammonium (CTMA(+)) cations were successfully loaded on the surface of bentonite. The combination of CTMAB2.5 adsorption and TiO2 photocatalysis was superior to either running separately. Furthermore, removal efficiency of simultaneously utilizing CTMAB2.5 and TiO2 was better than them in succession. The combination technology was feasible and was optimized by response surface methodology (RSM) with COD and NH3-N removal rate as the target responses. The optimal operation conditions calculated from the regression equations were CTMAB2.5 dosage of 7.5 g/L, pH at 3.5, TiO2 dosage of 1.63 g/L, and reaction time for 60.02 min, which maintained the removal of COD and NH3-N at 82% and 37%, respectively. PMID:24853137

  19. Binding and relaxometric properties of heme complexes with cyanogen bromide fragments of human serum albumin.

    PubMed Central

    Monzani, Enrico; Curto, Maria; Galliano, Monica; Minchiotti, Lorenzo; Aime, Silvio; Baroni, Simona; Fasano, Mauro; Amoresano, Angela; Salzano, Anna Maria; Pucci, Piero; Casella, Luigi

    2002-01-01

    The spectroscopic and reactivity properties of hemin complexes formed with cyanogen bromide fragments B (residues 1-123), C (124-298), A (299-585), and D (1-298) of human serum albumin (HSA) have been investigated. The complex hemin-D exhibits binding, spectral, circular dichroism, and reactivity characteristics very similar to those of hemin-HSA, indicating that fragment D contains the entire HSA domain involved in heme binding. The characteristics of the other hemin complexes are different, and a detailed investigation of the properties of hemin-C has been carried out because this fragment contains the HSA binding region of several important drugs. Hemin-C contains a low-spin Fe(III) center, with two imidazole ligands, but the complex undergoes a reversible structural transition at basic pH leading to a high-spin, five-coordinated Fe(III) species. This change determines a marked increase in the relaxation rate of water protons. Limited proteolysis experiments and mass spectral analysis carried out on fragment C and hemin-C show that the region encompassing residues Glu-208 to Trp-214 is protected from activity of proteases in the complex and, therefore, is involved in the interaction with hemin. A structural model of fragment C enables us to propose that His-242 and His-288 are the axial ligands for the Fe(III) center. PMID:12324442

  20. Cytotoxic veraguamides, alkynyl bromide-containing cyclic depsipeptides from the marine cyanobacterium cf. Oscillatoria margaritifera.

    PubMed

    Mevers, Emily; Liu, Wei-Ting; Engene, Niclas; Mohimani, Hosein; Byrum, Tara; Pevzner, Pavel A; Dorrestein, Pieter C; Spadafora, Carmenza; Gerwick, William H

    2011-05-27

    A family of cancer cell cytotoxic cyclodepsipeptides, veraguamides A-C (1-3) and H-L (4-8), were isolated from a collection of cf. Oscillatoria margaritifera obtained from the Coiba National Park, Panama, as part of the Panama International Cooperative Biodiversity Group program. The planar structure of veraguamide A (1) was deduced by 2D NMR spectroscopy and mass spectrometry, whereas the structures of 2-8 were mainly determined by a combination of 1H NMR and MS2/MS3 techniques. These new compounds are analogous to the mollusk-derived kulomo'opunalide natural products, with two of the veraguamides (C and H) containing the same terminal alkyne moiety. However, four veraguamides, A, B, K, and L, also feature an alkynyl bromide, a functionality that has been previously observed in only one other marine natural product, jamaicamide A. Veraguamide A showed potent cytotoxicity to the H-460 human lung cancer cell line (LD50=141 nM).

  1. Binding of dyes to hydroxyapatite treated with cetylpyridinium chloride or cetrimonium bromide.

    PubMed

    Jensen, J E

    1978-03-01

    The effect of cetylpyridinium chloride (CPC) and cetrimonium bromide (CTAB) on the adsorption of some acidic food dyes to hydroxyapatite was studied. The dyes investigated were brilliant blue (FD&C Blue No. 1), tartrazine (FD&C Yellow No. 5), sunset yellow (FD&C Yellow No. 6) and amaranth (FD&C Red No. 2). The apatite had adsorbed 9.2 mumol CPC per g dry weight. The adsorbed CPC was in equilibrium with a free concentration of 20 microgram/ml (58 micrometer). The adsorption of CPC and CTAB to the apatite was followed by an increased ability of the crystals to bind the dyes. The dyes were very firmly adsorbed and were not released during a series of washings. Untreated apatite showed only a minor affinity for the dyes. The adsorbed dyes were easily washed out. CPC and CTAB showed the smae specific ability to increase the binding capacity of the apatite. The results are discussed and related to the formation of stains on the teeth in persons using quaternary ammonium compounds for mouthrinsing. A mechanism explaining the production of stains is proposed.

  2. Revealing the potential of Didodecyldimethylammonium bromide as efficient scaffold for fabrication of nano liquid crystalline structures.

    PubMed

    Kanwar, Rohini; Kaur, Gurpreet; Mehta, S K

    2016-03-01

    To exploit the potential of Didodecyldimethylammonium bromide (D12DAB) as a core lipidic constituent, an attempt was made to fabricate and optimize cationic nanostructured lipid carriers (cNLCs) using a cost-effective microemulsification methodology. Designed composition was optimized by studying the effect of different microemulsion components on D12DAB cNLCs characteristics. ​Spherical shaped D12DAB cNLCs were obtained with an average size of ∼160 nm and zeta potential of +30.2 mV. Differential Scanning Calorimetry (DSC) depicted the presence of thermotropic character, whereas polarized optical microscopy confirmed the mesophase like behavior of D12DAB based cNLCs. In addition, hemolysis analysis revealed that the toxicity was concentration dependent as LC50 was reached at a concentration of 50 μg/mL of cNLCs. This class of cNLCs is expected to become a potent candidate for a broad spectrum of medicaments as carriers, targeting for pharmaceutical and medicinal purposes, due to the combination of a hard lipid with a soft lipid, where the liquid crystalline structure of the lipid co-exists.

  3. Electrodeposition of Nanocrystalline Chromium Coatings Based on 1-Butyl-3-Methylimidazolium-Bromide Ionic Liquid.

    PubMed

    He, Xinkuai; Zhu, Qingyun; Hou, Bailong; Cai, Youxing; Li, Chen; Fu, Liqin; Wu, Luye

    2015-12-01

    The electrochemical behavior of trivalent chromium reduction from 1-butyl-3-methylimidazolium-bromide ([BMIM]Br) ionic liquid is studied. The result of cyclic voltammetry shows that the Cr(III) reduction is irreversible and occurs in two steps, Cr(III)to Cr(II), and Cr(II) to Cr(0), respectively. In the electrochemical impedance spectroscopy measurements, the preferable equivalent circuit is made to fit the experimental data. The effects of electroplating parameters on coating thickness and electrodepositon rate are investigated by potentiostatic method on Cu electrode from Cr(III)-[BMIM]Br solution. The results show that the temperature and depositing potential have great effect on the coating thickness and electrodeposition rate. The surface morphology and composition of deposited Cr are investigated using scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). SEM analysis shows that chromium electrodeposits obtained on Cu electrodes present a ball-like structure. EDS analysis shows that the coatings are composed of Cr. Moreover, the corrosion resistance of the as-deposited chromium layer is evaluated using polarization curves. The results show that the corrosion resistance of the chromium coatings obtained at higher potential is better.

  4. Effects of the ionic liquid 1-hexyl-3-methylimidazolium bromide on root gravitropism in Arabidopsis seedlings.

    PubMed

    Zhang, Liang; Wang, Tianqi; Zheng, Fengxia; Ma, Lingyu; Li, Jingyuan

    2016-03-01

    The toxic effects of ionic liquids (ILs) have attracted increasing attention in recent years. However, the knowledge about the toxic effects of ILs on tropism in organisms remains quite limited. In this study, the effects of 1-hexyl-3-methylimidazolium bromide [C6mim]Br on root gravitropism were evaluated using Arabidopsis seedlings. Our results showed that the root growth and gravity response were significantly inhibited with increasing IL concentration. [C6mim]Br treatment affected the amount and distribution pattern of amyloplasts in root cap compared with controls. The auxin distribution marked with DR5rev::VENUS was altered in IL-treated seedlings. The signal intensity and gene expression of auxin efflux carriers PIN2 and PIN3 were obviously decreased by IL stress. Moreover, as consequences in response to gravity stimulus, the asymmetric DR5 signals in control root apex were impaired by IL treatment. The predominant PIN2 signals along the lower flank of root and PIN3 polarization in columella cells were also significantly reduced in seedlings exposed to IL. Our results suggest that the ionic liquid [C6mim]Br affects the amount and distribution of amyloplasts and disturbs the deployment of PIN2 and PIN3, thus impairing auxin flows in response to gravity stimulus and causing deficient root gravitropism in Arabidopsis seedlings. PMID:26685782

  5. Topochemical and morphological characterization of wood cell wall treated with the ionic liquid, 1-ethylpyridinium bromide.

    PubMed

    Kanbayashi, Toru; Miyafuji, Hisashi

    2015-09-01

    MAIN CONCLUSION : [EtPy][Br] is more reactive toward lignin than toward the PSs in wood cell walls, and [EtPy][Br] treatment results in inhomogenous changes to the cell wall's ultrastructural and chemical components. The effects of the ionic liquid 1-ethylpyridinium bromide ([EtPy][Br]), which prefers to react with lignin rather than cellulose on the wood cell walls of Japanese cedar (Cryptomeria japonica), were investigated from a morphology and topochemistry point of view. The [EtPy][Br] treatment induced cell wall swelling, the elimination of warts, and the formation of countless pores in the tracheids. However, many of the pit membranes and the cellulose crystalline structure remained unchanged. Raman microscopic analyses revealed that chemical changes in the cell walls were different for different layers and that the lignin in the compound middle lamella and the cell corner resists interaction with [EtPy][Br]. Additionally, the interaction of [EtPy][Br] with the wood cell wall is different to that of other types of ionic liquid. PMID:25556160

  6. A Comprehensive Theoretical Investigation of the Molecular Properties of Methyl Bromide (CH3Br)

    NASA Astrophysics Data System (ADS)

    Yu, Ang-Yang; Efil, Kürşat; Yang, Rui; Hu, Qing-Miao

    2015-12-01

    The properties of the ground and the lowest excited state of methyl bromide (CH3Br) have been studied with and without inclusion of the solvent effects in this work. The geometric parameters, energies, and frequencies of the ground state and the triplet state are calculated by using the MP2(full)/6-311++G** level of theory. The vertical excitation for the singlet state is also investigated. It is found that the theoretical results performed by the TDDFT/B3P86/6-311++G** method are in the best agreement with the experimental results. In addition, the dissociation energy of CH3Br molecule is computed at MP2(full)/6-311++G** level of theory for the gas phase and in water. The ionisation potential (IP), electron affinity (EA), electronegativity (χ), electrophilicity index (ω), hardness (η), softness (S), and chemical potential (μ) values are calculated from HOMO-LUMO energies both in the gas phase and in solvent (water). These theoretical results could serve as a guide for future experimental investigations.

  7. 1-Pentamethylbenzyl-3-nbuthylbenzimidazolesilver(I)bromide complex: Synthesis, characterization and DFT calculations

    NASA Astrophysics Data System (ADS)

    Kunduracıoğlu, Ahmet; Tamer, Ömer; Avcı, Davut; Kani, İbrahim; Atalay, Yusuf; Çetinkaya, Bekir

    2014-03-01

    A novel NHC complex of silver(I) ion, 1-pentamethylbenzyl-3-nbuthylbenzimidazolesilver(I)bromide, was prepared and fully characterized by single crystal X-ray structure determination. FT-IR, NMR and UV-vis spectroscopies were employed to investigate the electronic transition behaviors of the complex. Additionally, the molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) 1H and 13C chemical shift and electronic transition values of silver(I) complex were calculated by using density functional theory levels (B3LYP and PBE1PBE) with LANL2DZ basis set. Also, the vibrational frequencies were supported on the basis of the potential energy distribution (PED) analysis calculated for PBE1PBE level. We were also investigated total static dipole moment (μ), the mean polarizability (<α>), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (<β>) of the title complex. Natural bond orbital (NBO) analysis was performed to determine the presence of hyperconjugative interactions, and charge distributions.

  8. 1-Pentamethylbenzyl-3-(n)buthylbenzimidazolesilver(I)bromide complex: synthesis, characterization and DFT calculations.

    PubMed

    Kunduracıoğlu, Ahmet; Tamer, Ömer; Avcı, Davut; Kani, Ibrahim; Atalay, Yusuf; Cetinkaya, Bekir

    2014-01-01

    A novel NHC complex of silver(I) ion, 1-pentamethylbenzyl-3-(n)buthylbenzimidazolesilver(I)bromide, was prepared and fully characterized by single crystal X-ray structure determination. FT-IR, NMR and UV-vis spectroscopies were employed to investigate the electronic transition behaviors of the complex. Additionally, the molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) (1)H and (13)C chemical shift and electronic transition values of silver(I) complex were calculated by using density functional theory levels (B3LYP and PBE1PBE) with LANL2DZ basis set. Also, the vibrational frequencies were supported on the basis of the potential energy distribution (PED) analysis calculated for PBE1PBE level. We were also investigated total static dipole moment (μ), the mean polarizability (〈α〉), the anisotropy of the polarizability (Δα), the mean first-order hyperpolarizability (〈β〉) of the title complex. Natural bond orbital (NBO) analysis was performed to determine the presence of hyperconjugative interactions, and charge distributions. PMID:24220668

  9. Ozone Therapy in Ethidium Bromide-Induced Demyelination in Rats: Possible Protective Effect.

    PubMed

    Salem, Neveen A; Assaf, Naglaa; Ismail, Manal F; Khadrawy, Yasser A; Samy, Mohga

    2016-08-01

    Multiple sclerosis, an autoimmune inflammatory disease of the central nervous system, is characterized by excessive demyelination. The study aimed to investigate the possible protective effect of ozone (O3) therapy in ethidium bromide (EB)-induced demyelination in rats either alone or in combination with corticosteroids in order to decrease the dose of steroid therapy. Rats were divided into Group (1) normal control rats received saline, Group (2) Sham-operated rats received saline, Group (3) Sham-operated rats received vehicle (oxygen), Group (4) EB-treated rats received EB, Group (5) EB-treated rats received O3, Group (6) EB-treated rats received methylprednisolone (MP), and Group (7) EB-treated rats received half the dose of MP concomitant with O3. EB-treated rats showed a significant increase in the number of footfalls in the grid walk test, decreased brain GSH, and paraoxonase-1 enzyme activity, whereas brain MDA, TNF-α, IL-1β, INF-γ, Cox-2 immunoreactivity, and p53 protein levels were increased. A significant decline in brain serotonin, dopamine, norepinephrine, and MBP immunoreactivity was also reported. Significant improvement of the above-mentioned parameters was demonstrated with the administration of either MP or O3, whereas best amelioration was achieved by combining half the dose of MP with ozone. PMID:26467344

  10. Methyl bromide emissions from a covered field: III. Correcting chamber flux for temperature

    SciTech Connect

    Yates, S.R.; Gan, J.; Ernst, F.F.; Wang, D.

    1996-07-01

    An experiment was conducted to investigate the environmental fate and transport of methyl bromide (MeBr) in agricultural systems. Part of this experiment involved the use of three flow-through chambers to estimate the MeBr flux through a sheet of clear polyethylene plastic covering the field. Using the chamber data, the total mass lost to the atmosphere was estimated to be 96% of the applied mass, and the results were highly variable between chambers (i.e., standard deviation of 298 kg or 35%). The air temperature inside the chamber was found to be much higher than the air temperature outside and was highly correlated with the diurnal variation in incoming solar radiation. Since the diffusion through polyethylene film was found to be strongly dependent on the temperature, a method was developed to correct the chamber flux density data for enhanced diffusion caused by increases in the temperature inside the chamber. After correcting for temperature, the estimated total MeBr emission was reduced to approximately 59% (21% standard deviation) of the applied amount, which is about 5% less than was measured using other methods. When chambers are used to measure volatilization of MeBr or other fumigants from fields covered with a sheet of polyethylene plastic, the chambers should be designed to minimize internal heating or some method should be used to correct the volatilization rate for the effects of temperature. 16 refs., 5 figs., 1 tab.

  11. Laboratory-scale measurements and simulations of effect of application methods on soil methyl bromide emission

    SciTech Connect

    Gan, J.; Yates, S.R.; Spencer, W.F.

    1997-01-01

    Methyl bromide (bromomethane, MeBr), which originates from the oceans, fumigation, and a few other sources, is reportedly contributing to the ozone depletion in the stratosphere. Due to the heavy reliance on this fumigant in the production of many crops, it is of particular importance to accurately quantify the atmospheric input of MeBr arising from agricultural uses, and develop feasible measures to minimize these emissions. In this study, we determined the effect of two important application variables, surface tarp and injection depth, on MeBr transport and transformation in the soil and its emission from the soil surface under controlled conditions. Following 20- and 30-cm injections, covering the soil surface with 1-mil (0.025 mm) high-density polyethylene film resulted in an average of 48% reduction in MeBr emission. Increasing the injection depth from 20 to 60 cm caused a decrease in MeBr emission of 54% under untarped conditions and 40% under tarped conditions. The influence of application methods on MeBr atmospheric emissions should be considered when estimating the contribution of agricultural fumigation to the overall atmospheric MeBr burden on a global scale. The results also indicate that MeBr emission after soil fumigation may be substantially minimized by using surface tarpaulins and deep injections. 34 refs., 5 figs., 1 tab.

  12. Growth and characterization of L-alanine cadmium bromide a semiorganic nonlinear optical crystals

    NASA Astrophysics Data System (ADS)

    Ilayabarathi, P.; Chandrasekaran, J.

    2012-10-01

    A new semiorganic nonlinear optical crystal, L-alanine cadmium bromide (LACB) was grown from aqueous solution by slow solvent evaporation method at room temperature. As grown crystals were characterized for its spectral, thermal, linear and second order nonlinear optical properties. LACB crystallizes in orthorhombic system and unit cell parameters a = 5.771(2) Å, b = 6.014(4) Å, c = 12.298(2) Å, α = β = γ = 90° and volume = 426.8(3) Å3. The mode of vibrations of different molecular groups present in the crystal was identified by FTIR study. The grown crystals were found to be transparent in the entire visible region. The thermal strength and the decomposition of the grown crystals were studied using TG/DTA and DSC analysis. Dielectric measurement revealed that the crystals had very low dielectric constant at higher frequency in room temperature. The mechanical behavior was studied by Vicker's microhardness tester. The grown crystal has negative photoconductivity nature. The fluorescence spectrum of the crystal was recorded and its optical band gap is about 3.356 eV. The NLO property of crystal using modified Kurtz-Perry powder technique with Nd:YAG laser light of wavelength 1064 nm indicated that their second harmonic generation (SHG) efficiency was half that of pure KDP.

  13. Water-lithium bromide double-effect absorption cooling analysis. Final report

    SciTech Connect

    Vliet, G.C.; Lawson, M.B.; Lithgow, R.A.

    1980-12-01

    This investigation involved the development of a numerical model for the transient simulation of the double-effect, water-lithium bromide absorption cooling machine, and the use of the model to determine the effect of the various design and input variables on the absorption unit performance. The performance parameters considered were coefficient of performance and cooling capacity. The sensitivity analysis was performed by selecting a nominal condition and determining performance sensitivity for each variable with others held constant. The variables considered in the study include source hot water, cooling water, and chilled water temperatures; source hot water, cooling water, and chilled water flow rates; solution circulation rate; heat exchanger areas; pressure drop between evaporator and absorber; solution pump characteristics; and refrigerant flow control methods. The performance sensitivity study indicated in particular that the distribution of heat exchanger area among the various (seven) heat exchange components is a very important design consideration. Moreover, it indicated that the method of flow control of the first effect refrigerant vapor through the second effect is a critical design feature when absorption units operate over a significant range of cooling capacity. The model was used to predict the performance of the Trane absorption unit with fairly good accuracy. The dynamic model should be valuable as a design tool for developing new absorption machines or modifying current machines to make them optimal based on current and future energy costs.

  14. Survey on fluoride, bromide and chloride contents in public drinking water supplies in Sicily (Italy).

    PubMed

    D'Alessandro, Walter; Bellomo, Sergio; Parello, Francesco; Brusca, Lorenzo; Longo, Manfredi

    2008-10-01

    Six hundred and sixty-seven water samples were collected from public drinking water supplies in Sicily and analysed for electric conductivity and for their Cl(-), Br(-) and F(-) contents. The samples were, as far as possible, collected evenly over the entire territory with an average sampling density of about one sample for every 7,600 inhabitants. The contents of Cl(-) and Br(-), ranging between 5.53 and 1,302 mg/l and between <0.025 and 4.76 mg/l respectively, correlated well with the electric conductivity, a parameter used as a proxy for water salinity. The highest values were found both along the NW and SE coasts, which we attributed to seawater contamination, and in the central part of Sicily, which we attributed to evaporitic rock dissolution. The fluoride concentrations ranged from 0.023 to 3.28 mg/l, while the highest values (only three exceeding the maximum admissible concentration of 1.5 mg/l) generally correlated either with the presence in the area of crystalline (volcanic or metamorphic) or evaporitic rocks or with contamination from hydrothermal activity. Apart from these limited cases of exceeding F(-) levels, the waters of public drinking water supplies in Sicily can be considered safe for human consumption for the analysed parameters. Some limited concern could arise from the intake of bromide-rich waters (about 3% exceeding 1 mg/l) because of the potential formation of dangerous disinfection by-products. PMID:18064536

  15. Electrochemical Sensing of Bisphenol A by a Didodecyldimethylammonium Bromide-Modified Expanded Graphite Paste Electrode.

    PubMed

    Zhang, Jing; Ma, Sa; Wang, Wenchang; Chen, Zhidong

    2016-07-01

    An electrochemical and sensitive sensing of 2,2-bis(4-hydroxyphenyl) propane [bisphenol A (BPA)] was developed based on a didodecyldimethylammonium bromide-modified expanded graphite paste electrode (DDAB-EGPE). The DDAB-EGPE was prepared by suspending an EGPE in a DDAB aqueous solution, and allowing the DDAB to form a hydrophobic film on the expanded graphite surface. Compared with the EGPE, the DDAB-EGPE showed improved electrochemical response of BPA because of the preconcentration of BPA in DDAB via hydrophobic interaction. Due to the electrocatalytic activity of BPA, a sensor for BPA was constructed based on the DDAB-EGPE. The DDAB-EGPE exhibited a wide linear response to BPA ranging from 6.0 × 10(-8) to 2.0 × 10(-5) mol/L with a detection limit of 7.1 nmol/L at S/N = 3. The designed sensor showed good reproducibility and stability. The proposed sensor was successfully applied to the determination of BPA in three types of real plastic product samples. This sensor presented a simple, rapid, and sensitive platform for the determination of BPA and could become a versatile and powerful tool for food safety. PMID:27213485

  16. Evaluation of potential performance additives for the advanced lithium bromide chiller

    SciTech Connect

    Reiner, R.H.; Del Cul, W.; Perez-Blanco, H.; Ally, M.R.; Zaltash, A.

    1991-04-01

    The effectiveness and stability of potential heat-and-mass transfer (performance) additives for an advanced lithium bromide (LiBr) chiller were evaluated in a series of experimental studies. These studies of additive effectiveness and stability were necessary because many currently used performance additives decompose at the high generator temperatures (220{degrees}C to 260{degrees}C) desired for this particular advanced LiBr chiller. For example, one common performance additive, 2-ethyl-l-hexanol (2EH), reacts with the corrosion inhibitor, lithium chromate (Li{sub 2}CrO{sub 4}), even at moderate generator temperatures ({ge}180{degrees}C). These stability problems can be mitigated by using less reactive corrosion inhibitors such as lithium molybdate (Li{sub 2}MoO{sub 4}) and by using more stable performance additives such as 1-heptanol (HEP) or 1H,1H,7H-dodecafluoro-1-heptanol (DFH). There seems to be a trade-off between additive stability and effectiveness: the most effective performance additives are not the most stable additives. These studies indicate that HEP or DFH may be effective additives in the advanced LiBr chiller if Li{sub 2}MoO{sub 4} is used as a corrosion inhibitor.

  17. Computational study of dissociative electron attachment to π-allyl ruthenium (II) tricarbonyl bromide

    NASA Astrophysics Data System (ADS)

    Thorman, Rachel M.; Bjornsson, Ragnar; Ingólfsson, Oddur

    2016-08-01

    Motivated by the current interest in low energy electron induced fragmentation of organometallic complexes in focused electron beam induced deposition (FEBID) we have evaluated different theoretical protocols for the calculation of thermochemical threshold energies for DEA to the organometallic complex π-allyl ruthenium (II) tricarbonyl bromide. Several different computational methods including density functional theory (DFT), hybrid-DFT and coupled cluster were evaluated for their ability to predict these threshold energies and compared with the respective experimental values. Density functional theory and hybrid DFT methods were surprisingly found to have poor reliability in the modelling of several DEA reactions; however, the coupled cluster method LPNO-pCCSD/2a was found to produce much more accurate results. Using the local correlation pair natural orbital (LPNO) methodology, high level coupled cluster calculations for open-shell systems of this size are now affordable, paving the way for reliable theoretical DEA predictions of such compounds. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  18. Instrument processing with lauryl dimethyl benzyl ammonium bromide: a challenge for patient safety.

    PubMed

    Bello-Gonzalez, Teresita; Rosales-Pantoja, Patricia; Acosta-Gio, A Enrique; de Waard, Jacobus H

    2008-10-01

    The quaternary ammonium compound (QUAT) lauryl dimethyl benzyl ammonium bromide (LDBAB) is commercialized in the Caribbean, Central, and South America under label claims to sterilize medical and dental instruments in 30 minutes or less. But QUAT formulations are classified as low-level disinfectants with no sporicidal activity or tuberculocidal efficacy. This study evaluated the presumptive sporicidal and tuberculocidal activities of 2 LDBAB formulations with label claims of high-level disinfectant action used widely in the Americas. In this study, sporicidal activity was evaluated against a challenge inoculum of 10(6)Bacillus atrophaeus spores. Tuberculocidal activity was evaluated against Mycobacterium tuberculosis H37Rv using the quantitative suspension test described in European Standard EN14348:2005. Tested at the recommended product concentrations indicated on their respective labels, both LDBAB solutions failed to demonstrate sporicidal activity and tuberculocidal efficacy. These findings underscore the need for public health authorities, as well as medical and dental professionals, to correctly identify LDBAB as a low-level disinfectant and avoid its use in instrument processing, a practice that may endanger lives.

  19. Methyl chloride and methyl bromide emissions from baking: an unrecognized anthropogenic source.

    PubMed

    Thornton, Brett F; Horst, Axel; Carrizo, Daniel; Holmstrand, Henry

    2016-05-01

    Methyl chloride and methyl bromide (CH3Cl and CH3Br) are the largest natural sources of chlorine and bromine, respectively, to the stratosphere, where they contribute to ozone depletion. We report the anthropogenic production of CH3Cl and CH3Br during breadbaking, and suggest this production is an abiotic process involving the methyl ester functional groups in pectin and lignin structural polymers of plant cells. Wide variations in baking styles allow only rough estimates of this flux of methyl halides on a global basis. A simple model suggests that CH3Br emissions from breadbaking likely peaked circa 1990 at approximately 200tonnes per year (about 0.3% of industrial production), prior to restrictions on the dough conditioner potassium bromate. In contrast, CH3Cl emissions from breadbaking may be of similar magnitude as acknowledged present-day CH3Cl industrial emissions. Because the mechanisms involve functional groups and compounds widely found in plant materials, this type of methyl halide production may occur in other cooking techniques as well. PMID:26878644

  20. Photocontrol of Voltage-Gated Ion Channel Activity by Azobenzene Trimethylammonium Bromide in Neonatal Rat Cardiomyocytes

    PubMed Central

    Frolova, Sheyda R.; Gaiko, Olga; Tsvelaya, Valeriya A.; Pimenov, Oleg Y.; Agladze, Konstantin I.

    2016-01-01

    The ability of azobenzene trimethylammonium bromide (azoTAB) to sensitize cardiac tissue excitability to light was recently reported. The dark, thermally relaxed trans- isomer of azoTAB suppressed spontaneous activity and excitation propagation speed, whereas the cis- isomer had no detectable effect on the electrical properties of cardiomyocyte monolayers. As the membrane potential of cardiac cells is mainly controlled by activity of voltage-gated ion channels, this study examined whether the sensitization effect of azoTAB was exerted primarily via the modulation of voltage-gated ion channel activity. The effects of trans- and cis- isomers of azoTAB on voltage-dependent sodium (INav), calcium (ICav), and potassium (IKv) currents in isolated neonatal rat cardiomyocytes were investigated using the whole-cell patch-clamp technique. The experiments showed that azoTAB modulated ion currents, causing suppression of sodium (Na+) and calcium (Ca2+) currents and potentiation of net potassium (K+) currents. This finding confirms that azoTAB-effect on cardiac tissue excitability do indeed result from modulation of voltage-gated ion channels responsible for action potential. PMID:27015602

  1. Application of cetyltrimethylammonium bromide bentonite-titanium dioxide photocatalysis technology for pretreatment of aging leachate.

    PubMed

    Cai, Fei-Fei; Yang, Zhao-Hui; Huang, Jing; Zeng, Guang-Ming; Wang, Li-Ke; Yang, Jian

    2014-06-30

    Organobentonite-photocatalysis technology was applied to pretreat aging leachate containing refractory pollutants. The organobentonite was synthesized by organic modifier cetyltrimethylammonium bromide (CTMAB) and natural bentonite. In characterization experiments, we could confirm that organic functional groups of cetyltrimethylammonium (CTMA(+)) cations were successfully loaded on the surface of bentonite. The combination of CTMAB2.5 adsorption and TiO2 photocatalysis was superior to either running separately. Furthermore, removal efficiency of simultaneously utilizing CTMAB2.5 and TiO2 was better than them in succession. The combination technology was feasible and was optimized by response surface methodology (RSM) with COD and NH3-N removal rate as the target responses. The optimal operation conditions calculated from the regression equations were CTMAB2.5 dosage of 7.5 g/L, pH at 3.5, TiO2 dosage of 1.63 g/L, and reaction time for 60.02 min, which maintained the removal of COD and NH3-N at 82% and 37%, respectively.

  2. Room temperature X- and gamma-ray detectors using thallium bromide crystals

    NASA Astrophysics Data System (ADS)

    Hitomi, K.; Muroi, O.; Shoji, T.; Suehiro, T.; Hiratate, Y.

    1999-10-01

    Thallium bromide (TlBr) is a compound semiconductor with wide band gap (2.68eV) and high X- and γ-ray stopping power. The TlBr crystals were grown by the horizontal travelling molten zone (TMZ) method using purified material. Two types of room temperature X- and γ-ray detectors were fabricated from the TlBr crystals: TlBr detectors with high detection efficiency for positron annihilation γ-ray (511keV) detection and TlBr detectors with high-energy resolution for low-energy X-ray detection. The detector of the former type demonstrated energy resolution of 56keV FWHM (11%) for 511keV γ-rays. Energy resolution of 1.81keV FWHM for 5.9keV was obtained from the detector of the latter type. In order to analyze noise characteristics of the detector-preamplifier assembly, the equivalent noise charge (ENC) was measured as a function of the amplifier shaping time for the high-resolution detector. This analysis shows that parallel white noise and /1/f noise were dominant noise sources in the detector system. Current-voltage characteristics of the TlBr detector with a small Peltier cooler were also measured. Significant reduction of the detector leakage current was observed for the cooled detectors.

  3. Aclidinium bromide/formoterol fixed-dose combination therapy for COPD: the evidence to date

    PubMed Central

    Moitra, Subhabrata; Bhome, Arvind B; Brashier, Bill B

    2015-01-01

    The quest for the right combination of bronchodilators with different mechanisms of action such as long-acting muscarinic antagonists and long-acting β-agonists in the management of stable moderate-to-severe chronic obstructive pulmonary disease (COPD) is a topic of intense research activity currently, given the rising morbidity and mortality due to this disease. The fixed-dose combination of aclidinium bromide and formoterol fumarate in a single inhaler seems to offer superior advantages over either drugs given alone or as separate inhalers concurrently. Since the fixed-dose combination needs to be given twice daily, it is likely to achieve control of symptoms most crucial to the quality of life in COPD, namely, the morning hours. This is reflected in significant trough FEV1 (forced expiratory volume in 1 second) improvements after the dose. This paper reviews the various studies related to this combination put in the perspective of its safety and efficacy and potential benefits over other therapeutic options. However, there is a dearth of data on the long-term safety and efficacy in terms of improvement in lung function. This combination could emerge as an excellent option in the management of stable COPD if data on exacerbation rates and patient-reported outcomes become available from longer-term studies. Moreover, we need some more studies to define the ideal phenotype of COPD best suited for the use of this combination. PMID:25897208

  4. Removal of bromide and bromate from drinking water using granular activated carbon.

    PubMed

    Zhang, Yong-Qing; Wu, Qing-Ping; Zhang, Ju-Mei; Yang, Xiu-Hua

    2015-03-01

    Granular activated carbon (GAC) was used to remove bromide (Br⁻) and bromate (BrO(3)(-)) from drinking water in both bench- and pilot-scale experiments. The present study aims to minimize BrO(3)(-) formation and eliminate BrO(3)(-) generated during the ozonation of drinking water, particularly in packaged drinking water. Results show that the Br⁻ and BrO(3)(-) levels in GAC-treated water decreased in both bench- and pilot-scale experiments. In the bench-scale experiments, when the empty bed contact time (EBCT) was 5 min, the highest reduction rates of Br(-) in the mineral and ultrapure water were found to be 74.9% and 91.2%, respectively, and those of BrO(3)(-) were 94.4% and 98.8%, respectively. The GAC capacity for Br⁻ and BrO(3)(-) removal increased with the increase in EBCT. Reduction efficiency was better in ultrapure water than in mineral water. In the pilot-scale experiments, the minimum reduction rates of Br⁻ and BrO(3)(-) were 38.5% and 73.2%, respectively. PMID:25719467

  5. Dehalogenative Homocoupling of Terminal Alkynyl Bromides on Au(111): Incorporation of Acetylenic Scaffolding into Surface Nanostructures.

    PubMed

    Sun, Qiang; Cai, Liangliang; Ma, Honghong; Yuan, Chunxue; Xu, Wei

    2016-07-26

    On-surface C-C coupling reactions of molecular precursors with alkynyl functional groups demonstrate great potential for the controllable fabrication of low-dimensional carbon nanostructures/nanomaterials, such as carbyne, graphyne, and graphdiyne, which demand the incorporation of highly active sp-hybridized carbons. Recently, through a dehydrogenative homocoupling reaction of alkynes, the possibility was presented to fabricate surface nanostructures involving acetylenic linkages, while problems lie in the fact that different byproducts are inevitably formed when triggering the reactions at elevated temperatures. In this work, by delicately designing the molecular precursors with terminal alkynyl bromide, we introduce the dehalogenative homocoupling reactions on the surface. As a result, we successfully achieve the formation of dimer structures, one-dimensional molecular wires and two-dimensional molecular networks with acetylenic scaffoldings on an inert Au(111) surface, where the unexpected C-Au-C organometallic intermediates are also observed. This study further supplements the database of on-surface dehalogenative C-C coupling reactions, and more importantly, it provides us an alternative efficient way for incorporating the acetylenic scaffolding into low-dimensional surface nanostructures. PMID:27326451

  6. Revealing the potential of Didodecyldimethylammonium bromide as efficient scaffold for fabrication of nano liquid crystalline structures.

    PubMed

    Kanwar, Rohini; Kaur, Gurpreet; Mehta, S K

    2016-03-01

    To exploit the potential of Didodecyldimethylammonium bromide (D12DAB) as a core lipidic constituent, an attempt was made to fabricate and optimize cationic nanostructured lipid carriers (cNLCs) using a cost-effective microemulsification methodology. Designed composition was optimized by studying the effect of different microemulsion components on D12DAB cNLCs characteristics. ​Spherical shaped D12DAB cNLCs were obtained with an average size of ∼160 nm and zeta potential of +30.2 mV. Differential Scanning Calorimetry (DSC) depicted the presence of thermotropic character, whereas polarized optical microscopy confirmed the mesophase like behavior of D12DAB based cNLCs. In addition, hemolysis analysis revealed that the toxicity was concentration dependent as LC50 was reached at a concentration of 50 μg/mL of cNLCs. This class of cNLCs is expected to become a potent candidate for a broad spectrum of medicaments as carriers, targeting for pharmaceutical and medicinal purposes, due to the combination of a hard lipid with a soft lipid, where the liquid crystalline structure of the lipid co-exists. PMID:26896840

  7. An investigation of the atmospheric sources and sinks of Methyl Bromide

    NASA Technical Reports Server (NTRS)

    Singh, Hanwant B.; Kanakidou, M.

    1993-01-01

    Methyl Bromide (CH3Br) is a ubiquitous component of the atmosphere and has been implicated as an important player in the depletion of stratospheric ozone. Atmospheric CH3Br abundances, interhemispheric gradients, oceanic concentrations, man-made emissions, and removal processes have been analyzed and interpreted with the help of a simple box model and a 2D global photochemical model. Its calculated atmospheric lifetime (T) of 1.7-1.9 years, based on reaction with OH radicals, is consistent with a global source of 90-110 Gg (10 exp 9 g)/year. Consequences of a much shorter lifetime of 1.2 years, due to possible deposition/hydrolysis losses, are also considered. Available data are used to estimate a CH3Br source that is 35 percent (20-50 percent) man-made and 65 percent (80-50 percent) natural. Oceans are substantially supersaturated and provide the most important natural source of about 60 (40-80) Gg/year.

  8. Absorption characteristics of lithium bromide (LiBr) solution constrained by superhydrophobic nanofibrous structures

    SciTech Connect

    Isfahani, RN; Moghaddam, S

    2013-08-01

    An experimental study on absorption characteristics of water vapor into a thin lithium bromide (LiBr) solution flow is presented. The LiBr solution flow is constrained between a superhydrophobic vapor permeable wall and a solid surface that removes the heat of absorption. As opposed to conventional falling film absorbers, in this configuration, the solution film thickness and velocity can be controlled independently to enhance the absorption rate. The effects of water vapor pressure, cooling surface temperature, solution film thickness, and solution flow velocity on the absorption rate are studied. An absorption rate of approximately 0.006 kg/m(2) s was measured at a LiBr solution channel thickness and flow velocity of 100 mu m and 5 mm/s, respectively. The absorption rate increased linearly with the water vapor driving potential at the test conditions of this study. It was demonstrated that decreasing the solution film thickness and increasing the solution velocity enhance the absorption rate. The high absorption rate and the inherently compact form of the proposed,absorber facilitate development of compact small-scale waste heat or solar-thermal driven cooling systems. Published by Elsevier Ltd.

  9. Factors affecting the stability and performance of ipratropium bromide; fenoterol hydrobromide pressurized-metered dose inhalers.

    PubMed

    Ninbovorl, Jenjira; Sawatdee, Somchai; Srichana, Teerapol

    2013-12-01

    The aim of the study was to investigate the factors affecting the stability and performance of ipratropium bromide and fenoterol hydrobromide in a pressurized-metered dose inhaler (pMDI). A factorial design was applied to investigate the effects of three parameters (propellant, water, and ethanol) on the performance of 27 designed formulations of a solution-based pMDI. The formulations that contained a hydrofluoroalkane (HFA) propellant lower than 72% v/v and an ethanol concentration higher than 27% v/v remained as clear solutions. Nine formulations that contained the HFA propellant higher than 74% v/v precipitated. The results indicated that it was not only the HFA propellant content of the formulations that was related to the formulation instability but also ethanol content. Only six formulations from the 18 formulations, that did not precipitate, produced drug contents that were within the acceptable range (80-120%). These six formulations generated aerosols with mass median aerodynamic diameters (MMAD) of approximately 2 μm with a fine particle fraction (FPF; particle size, <6.4 μm) between 45% and 52%. The MMAD and FPF did not change significantly after 6 months of storage (P > 0.05). PMID:23975571

  10. Methyl chloride and methyl bromide emissions from baking: an unrecognized anthropogenic source.

    PubMed

    Thornton, Brett F; Horst, Axel; Carrizo, Daniel; Holmstrand, Henry

    2016-05-01

    Methyl chloride and methyl bromide (CH3Cl and CH3Br) are the largest natural sources of chlorine and bromine, respectively, to the stratosphere, where they contribute to ozone depletion. We report the anthropogenic production of CH3Cl and CH3Br during breadbaking, and suggest this production is an abiotic process involving the methyl ester functional groups in pectin and lignin structural polymers of plant cells. Wide variations in baking styles allow only rough estimates of this flux of methyl halides on a global basis. A simple model suggests that CH3Br emissions from breadbaking likely peaked circa 1990 at approximately 200tonnes per year (about 0.3% of industrial production), prior to restrictions on the dough conditioner potassium bromate. In contrast, CH3Cl emissions from breadbaking may be of similar magnitude as acknowledged present-day CH3Cl industrial emissions. Because the mechanisms involve functional groups and compounds widely found in plant materials, this type of methyl halide production may occur in other cooking techniques as well.

  11. N-Phenacylthiazolium Bromide Reduces Bone Fragility Induced by Nonenzymatic Glycation

    PubMed Central

    Bradke, Brian S.; Vashishth, Deepak

    2014-01-01

    Nonenzymatic glycation (NEG) describes a series of post-translational modifications in the collagenous matrices of human tissues. These modifications, known as advanced glycation end-products (AGEs), result in an altered collagen crosslink profile which impacts the mechanical behavior of their constituent tissues. Bone, which has an organic phase consisting primarily of type I collagen, is significantly affected by NEG. Through constant remodeling by chemical resorption, deposition and mineralization, healthy bone naturally eliminates these impurities. Because bone remodeling slows with age, AGEs accumulate at a greater rate. An inverse correlation between AGE content and material-level properties, particularly in the post-yield region of deformation, has been observed and verified. Interested in reversing the negative effects of NEG, here we evaluate the ability of n-phenacylthiazolium bromide (PTB) to cleave AGE crosslinks in human cancellous bone. Cancellous bone cylinders were obtained from nine male donors, ages nineteen to eighty, and subjected to one of six PTB treatments. Following treatment, each specimen was mechanically tested under physiological conditions to failure and AGEs were quantified by fluorescence. Treatment with PTB showed a significant decrease in AGE content versus control NEG groups as well as a significant rebound in the post-yield material level properties (p<0.05). The data suggest that treatment with PTB could be an effective means to reduce AGE content and decrease bone fragility caused by NEG in human bone. PMID:25062024

  12. Pyridostigmine bromide does not alter thermoregulation during exercise in cold air

    SciTech Connect

    Roberts, D.E.; Sawka, M.N.; Young, A.J.; Freund, B.J.

    1994-12-31

    This study examined the effects of acute and chronic pyridostigmine bromide (PB) administration on thermoregulatory and metabolic responses to exercise in cold air (5 C). Seven healthy men completed two 7-day trials in a double-blind, crossover experimental design: during one trial they received PB (30 mg three times daily) and during the other trial they received placebo. For each trial, subjects attempted four (3 h) exercise tests: low-intensity exercise (25% Vo2max) and moderate- intensity exercise (-50% Vo2max), on days 2 and 3 and again on days 6 and 7. Metabolic rate, body temperatures, and venous blood samples were obtained before and during exercise. Red blood cell acerylcholinesterase inhibition induced by PB increased (p < 0.05) from 34% on day I to 43% on days 3-7 Metabolic rate, body temperatures, and regional heat conductance responses were not different between trials. Plasma glucose, glycerol, free fatty acid, lactate, sodium, and potassium concentrations were not different between trials. In addition. differences were not found between acute and chronic experiments for any thermoregulatory or metabolic responses. These findings demonstrate that the PB dosage used by military personnel, as a pharmacological defense against nerve-agent poisoning. should not cause any adverse thermoregulatory or metabolic effects during moderate activity in cold climates.

  13. Spectroscopic study of tetradecyltrimethylammonium bromide Pt-C14TAB nanoparticles: Structure and Stability

    SciTech Connect

    Borodko, Y.; Jones, L.; Frei, H.; Somorjai, G.

    2009-01-09

    The vibrational spectra of platinum nanoparticles (12 nm) capped with tetradecyltrimethylammonium bromide, C{sub 14}TAB, were investigated by Fourier transform infrared (FTIR) spectroscopy. We have shown that the thermal decay of Pt-C{sub 14}TAB nanoparticles in N{sub 2}, H{sub 2} and O{sub 2} atmospheres leads to the release of hydrocarbon chain of surfactant and the formation of strongly bonded layer of ammonium cations on the platinum surface. The platinum atoms accessible to CO chemisorptions were not reducible by hydrogen in the temperature ranging from 30 C to 200 C. A FTIR spectrum of C{sub 14}TAB adsorbed on Pt nanoparticles dramatically perturbed as compared with pure C{sub 14}TAB. New intense and broad bands centered at 1450 cm{sup -1} and 760 cm{sup -1} are making their appearance in Pt-C{sub 14}TAB. It may be speculated, that new bands are result of coupling between conducting electrons of Pt and molecular vibrations of adsorbed C{sub 14}TAB and as a consequence specific vibrational modes of ammonium cation transformed into electron-vibrational modes.

  14. Ion transport properties of magnesium bromide/dimethyl sulfoxide non-aqueous liquid electrolyte

    PubMed Central

    Sheha, E.

    2015-01-01

    Nonaqueous liquid electrolyte system based dimethyl sulfoxide DMSO and magnesium bromide (MgBr2) is synthesized via ‘Solvent-in-Salt’ method for the application in magnesium battery. Optimized composition of MgBr2/DMSO electrolyte exhibits high ionic conductivity of 10−2 S/cm at ambient temperature. This study discusses different concentrations from 0 to 5.4 M of magnesium salt, representing low, intermediate and high concentrations of magnesium salt which are examined in frequency dependence conductivity studies. The temperature dependent conductivity measurements have also been carried out to compute activation energy (Ea) by least square linear fitting of Arrhenius plot: ‘log σ − 1/T. The transport number of Mg2+ ion determined by means of a combination of d.c. and a.c. techniques is ∼0.7. A prototype cell was constructed using nonaqueous liquid electrolyte with Mg anode and graphite cathode. The Mg/graphite cell shows promising cycling. PMID:26843967

  15. Novel screen-printed electrode for the determination of dodecyltrimethylammonium bromide in water samples.

    PubMed

    Mohamed, Gehad G; Ali, Tamer Awad; El-Shahat, M F; Migahed, M A; Al-Sabagh, A M

    2012-12-01

    The construction and electrochemical response characteristics of a screen-printed electrode (SPE) for the determination of dodecyltrimethylammonium bromide (DTAB) are described. The sensor was based on the use of DTA-tetraphenylborate ion association complex as an electroactive material in screen-printed electrode with dioctylsebacate (DOS) as a solvent mediator. In aqueous solution of pH 3, the sensor displayed a stable response for six months with reproducible potential and linear response for surfactant over the concentration range 1.20 × 10(-2) -5.6 × 10(-7) mol L(-1) at 25 °C with Nernstian slope of 55.95 ± 0.58 mV decade(-1) for detection limit of 6.8 x 10(-6) mol L(-1) . The response time was 6-10 s. The selectivity coefficients indicate excellent selectivity for DTAB over many common cations (e.g. Mg(2+), Na(+), K+, Co(2+), Ni(2+), Ca(2+), Cl(-), I(-), SO(4)(-2) and cetylpyridinium chloride (CPC). The sensor was used successfully for the determining of DTAB in pure form and water samples with average recoveries of 99.98, 98.78, and 99.99%.

  16. Denaturation and intermediates study of two sturgeon hemoglobins by n-dodecyl trimethylammonium bromide.

    PubMed

    Ariaeenejad, Shohreh; Habibi-Rezaei, Mehran; Kavousi, Kaveh; Jamili, Shahla; Fatemi, Mohammad Reza; Hong, Jun; Poursasan, Najmeh; Sheibani, Nader; Moosavi-Movahedi, Ali A

    2013-02-01

    Varieties of hemoglobin (Hb) forms exist in fish, which are usually well adapted to the different ecological conditions or various habitats. In the current study, Hbs from two Sturgeon species of the Southern Caspian Sea Basin were purified and studied upon interaction with n-dodecyl trimethylammonium bromide (DTAB; as a cationic surfactant) by various methods including UV-visible absorption, dynamic light scattering (DLS), and ANS fluorescence spectrophotometry. The chemometric analysis of Hbs was investigated upon interaction with DTAB under titration, using UV-visible absorption spectra. The chemometric resolution techniques were used to determine the number of the components and mole fraction of the oxidized Hbs. These results provided the evidence for the existence of three different molecular components including native (N), intermediate (I) and denatured (D) in sturgeon Hbs. According to the distribution of intermediates, which were broadened in a range of DTAB concentration, the aggregation states, DLS experiments, and thermal stability (T(m) obtained by differential scanning calorimetry (DSC)), the Acipenser stellatus Hb was more stable compared to Acipenser persicus Hb. These results demonstrate a significant relationship between the stability of fish Hbs and the habitat depth requirements.

  17. Denaturation and intermediates study of two sturgeon hemoglobins by n-dodecyl trimethylammonium bromide

    PubMed Central

    Ariaeenejad, Shohreh; Habibi-Rezaei, Mehran; Kavousi, Kaveh; Jamili, Shahla; Fatemi, Mohammad Reza; Hong, Jun; Poursasan, Najmeh; Sheibani, Nader; Moosavi-Movahedi, Ali. A.

    2013-01-01

    Varieties of hemoglobin (Hb) forms exist in fish, which are usually well adapted to the different ecological conditions or various habitats. In the current study, Hbs from two Sturgeon species of the Southern Caspian Sea Basin were purified and studied upon interaction with n-dodecyl trimethylammonium bromide (DTAB; as a cationic surfactant) by various methods including UV-visible absorption, dynamic light scattering (DLS), and ANS fluorescence spectrophotometry. The chemometric analysis of Hbs was investigated upon interaction with DTAB under titration, using UV-visible absorption spectra. The chemometric resolution techniques were used to determine the number of the components and mole fraction of the oxidized Hbs. These results provided the evidence for the existence of three different molecular components including native (N), intermediate (I) and denatured (D) in sturgeon Hbs. According to the distribution of intermediates, which were broadened in a range of DTAB concentration, the aggregation states, DLS experiments, and thermal stability (Tm obtained by differential scanning calorimetry (DSC)), the Acipenser stellatus Hb was more stable compared to Acipenser persicus Hb. These results demonstrate a significant relationship between the stability of fish Hbs and the habitat depth requirements. PMID:23142155

  18. Energetic and binding properties of DNA upon interaction with dodecyl trimethylammonium bromide.

    PubMed

    Bathaie, S Z; Moosavi-Movahedi, A A; Saboury, A A

    1999-02-15

    The interaction of dodecyl trimethylammonium bromide (DTAB), a cationic surfactant, with calf thymus DNA has been studied by various methods, including potentiometric technique using DTAB-selective plastic membrane electrode at 27 and 37 degreesC, isothermal titration microcalorimetry and UV spectrophotometry at 27 degreesC using 0.05 M Tris buffer and 0.01 M NaCl at pH 7.4. The free energy is calculated from binding isotherms on the basis of Wyman binding potential theory and the enthalpy of binding according to van't Hoff relation. The enthalpy of unfolding has been determined by subtraction of the enthalpy of binding from the microcalorimetric enthalpy. The results show that, after the interaction of first DTAB molecule to DNA (base molarity) through the electrostatic interaction, the second DTAB molecule also binds to DNA through electrostatic interaction. At this stage, the predom-inant DNA conformational change occurs. Afterwards up to 20 DTAB molecules, below the critical micelle concentration of DTAB, bind through hydrophobic interactions.

  19. A Facile Electrochemical Sensor for Nonylphenol Determination Based on the Enhancement Effect of Cetyltrimethylammonium Bromide

    PubMed Central

    Lu, Qing; Zhang, Weina; Wang, Zhihui; Yu, Guangxia; Yuan, Yuan; Zhou, Yikai

    2013-01-01

    A facile electrochemical sensor for the determination of nonylphenol (NP) was fabricated in this work. Cetyltrimethylammonium bromide (CTAB), which formed a bilayer on the surface of the carbon paste (CP) electrode, displayed a remarkable enhancement effect for the electrochemical oxidation of NP. Moreover, the oxidation peak current of NP at the CTAB/CP electrode demonstrated a linear relationship with NP concentration, which could be applied in the direct determination of NP. Some experimental parameters were investigated, such as external solution pH, mode and time of accumulation, concentration and modification time of CTAB and so on. Under optimized conditions, a wide linear range from 1.0 × 10−7 mol·L−1 to 2.5 × 10−5 mol·L−1 was obtained for the sensor, with a low limit of detection at 1.0 × 10−8 mol·L−1. Several distinguishing advantages of the as-prepared sensor, including facile fabrication, easy operation, low cost and so on, suggest a great potential for its practical applications. PMID:23296332

  20. Molecular dynamics simulation of self-assembly of n-decyltrimethylammonium bromide micelles.

    PubMed

    Jorge, Miguel

    2008-06-01

    In this paper, a molecular dynamics simulation of surfactant self-assembly using realistic atomistic models is presented. The simulations are long enough to enable the observation of several processes leading to equilibrium, such as monomer addition and detachment, micelle dissolution, and micelle fusion. The self-assembly of DeTAB surfactants takes place in three stages: fast aggregation of monomers to form small disordered oligomers; ripening process by which larger aggregates grow at the expense of smaller ones; slower stage involving collisions between large micelles. The first two stages were described well by a simple kinetic model with a size-independent rate constant estimated from the self-diffusion coefficient and collision radius of an isolated monomer. The average cluster size, area per headgroup, degree of counterion dissociation, and critical micelle concentration estimated from the simulation are in reasonable agreement with experimental values. An all-atom and united-atom surfactant model were compared, and the results were seen to be almost independent of the choice of model. DeTAB micelles are spheroidal, with a hydrophobic core composed of tail atoms surrounded by a hydrophilic corona of head atoms. A Stern layer composed of bromide counterions was also identified. Water molecules solvate the counterions and the head atoms, penetrating into the micelle up to the location of the atom connecting the head to the aliphatic tail, in agreement with recent experimental observations.