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Sample records for 5-diphenyl tetrazolium bromide

  1. Ammonia-containing dimethyl sulfoxide: an improved solvent for the dissolution of formazan crystals in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay.

    PubMed

    Wang, Hengwei; Wang, Fengqing; Tao, Xinyi; Cheng, Hairong

    2012-02-01

    To reduce interference with the dissolution of formazan crystals in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay, we conducted a systematic investigation to study the effects of various buffers, HCl, NaOH, and ammonia. As a result, we identified an improved solvent, alkaline dimethyl sulfoxide (DMSO) containing 8 to 800 mM ammonia, which could dissolve formazan crystals in approximately 10 min so as to give a stable spectrum by eliminating buffering effects of the residual medium.

  2. Effects of the pH dependence of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide-formazan absorption on chemosensitivity determined by a novel tetrazolium-based assay.

    PubMed

    Plumb, J A; Milroy, R; Kaye, S B

    1989-08-15

    The tetrazolium dye, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), is reduced by live but not dead cells, and this reaction is used as the end point in a rapid drug-screening assay. It can also be used for accurate determinations of drug sensitivity but only if a quantitative relationship is established between cell number and MTT-formazan production. We have shown that reduction of MTT to MTT-formazan by cells is dependent on the amount of MTT in the incubation medium. The concentration required to give maximal MTT-formazan production differs widely between cell lines. The absorption spectrum of MTT-formazan varies with cell number and with pH. At a low cell density or a high pH, the absorption maximum is at a wavelength of 560 to 570 nm. However, at a high cell density or a low pH, there are two absorption maxima; one at 510 nm and a second at about 570 nm. Measurements of absorbance at 570 nm underestimate MTT-formazan production and, hence, cell number at high cell densities. This error can result in a 10-fold underestimation of chemosensitivity. Addition of a buffer at pH 10.5 to the solubilized MTT-formazan product can overcome the effects of both cell density and culture medium on the absorption spectrum. Provided that sufficient MTT is used and the pH of the MTT-formazan product is controlled, dye reduction can be used to estimate cell numbers in a simple chemosensitivity assay the results of which agree well with a commonly used clonogenic assay.

  3. 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.

  4. Potential of a soluble tetrazolium/formazan assay for the evaluation of filarial viability.

    PubMed

    Comley, J C; Turner, C H

    1990-04-01

    Using female Acanthocheilonema viteae we have investigated the bioreduction of the tetrazolium reagent XTT (2,3-bis(2-methoxy-4-nitro-sulphonyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide). Unlike the formazan formed by other tetrazolium salts, that derived from XTT readily diffuses out of A. viteae in vitro. Formazan formation can therefore be quantified by direct absorbance reading of the incubation medium, eliminating the need for a DMSO solubilization step. Optimum assay conditions involved a 4 h incubation, in the presence of the electron coupling agent phenazine methosulphate (PMS). Repeat 4 h incubations with XTT-PMS were well tolerated by worms for 5 consecutive days. This confirmed the low toxicity of XTT formazan and its usefulness in the semi-continuous assessment of filarial viability. In comparison to our previously reported MTT (3-(4, 5 dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide)-reduction assay XTT-PMS reduction showed comparable drug sensitivity and accuracy, however XTT-PMS appears to be at least 10-15 times less efficiently reduced by A. viteae females. A possible application of the XTT assay using female Onchocerca volvulus is discussed.

  5. Noncolorimetric measurement of cell activity in three-dimensional histoculture using the tetrazolium dye 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide: the pixel image analysis of formazan crystals.

    PubMed

    Colangelo, D; Guo, H Y; Connors, K M; Silvestro, L; Hoffman, R M

    1992-08-15

    We describe a novel system for measuring the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction in three-dimensional histoculture which is no longer dependent on colorimetric determination of extracted formazan, but rather is based on a pixel image analysis of formazan crystals, and which allows intratumor heterogeneity to be taken into account. The MTT test is based on the enzymatic reduction of the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-dipheniltetrazolium bromide to formazan crystals by living, metabolically active cells, but not in dead cells. The reaction was carried out in situ in six-well plates on gel-supported histocultured human tumors. After a 24-h incubation with different drugs the tumors were incubated with a solution of MTT. Frozen sections of the tumor pieces were made and the slides were then stained with a propidium iodide solution, whose fluorescence is proportional to the number of cells present. We demonstrate here that the formazan crystals, formed by MTT reduction, reflect polarized light and that this can be quantified by using an image analysis system based on bright-pixel quantitation directly on a frozen section of the original tissue. Combined with the use of the fluorescent dye propidium iodide, also measured by pixel analysis, we can express a ratio between the total amount of MTT reduction and the total number of cells present in the specimen that expresses the effect of drugs on the histocultured tumors. Since histology is well maintained in histoculture it is possible to take into account the heterogeneity present in the tumor with regard to drug response.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. The pyruvic acid analog 3-bromopyruvate interferes with the tetrazolium reagent MTS in the evaluation of cytotoxicity.

    PubMed

    Ganapathy-Kanniappan, Shanmugasundaram; Geschwind, Jean-Francois H; Kunjithapatham, Rani; Buijs, Manon; Syed, Labiq H; Rao, Pramod P; Ota, Shinichi; Vali, Mustafa

    2010-04-01

    3-Bromopyruvate (3BrPA) is a pyruvate analog known for its alkylating property. Recently, several reports have documented the antiglycolytic and anticancer effects of 3BrPA and its potential for therapeutic applications. 3BrPA-mediated cytotoxicity has been evaluated in vitro by various methods including tetrazolium salt (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide)-based assays such as MTT, MTS, and so on. However, growing body of evidences has shown that tetrazolium reagent may interfere with the test compounds. In this study, we investigated whether the tetrazolium reagent interferes with the assessment of 3BrPA cytotoxicity. The results of the tetrazolium-based MTS assay were compared with 3 distinct cell viability detection methods, that is, Trypan Blue staining, ATP depletion, and Annexin V staining in 2 different cell lines, Vx-2 and HepG2. The MTS assay data showed false positive results by indicating increased cell viability at 1 mM and 2 mM 3BrPA whereas the other cell viability assays demonstrated that both Vx-2 and HepG2 cells are not viable at the same treatment conditions. In order to validate the direct interaction of 3BrPA with MTS reagent, we tested cell-free media incubated with different concentrations of 3BrPA. The results of cell-free media showed an increase in absorbance in a dose-dependent manner confirming the interaction of MTS with 3BrPA. Thus, our data clearly demonstrate that 3BrPA interferes with the accuracy of MTS-based cytotoxicity evaluation. Hence, we suggest that employing multiple methods of biochemical as well as morphological cytotoxicity assays is critical to evaluate 3BrPA-mediated cell death.

  7. 4,5-Diphenyl-1-methylimidazole: An Undergraduate Laboratory Experiment.

    ERIC Educational Resources Information Center

    Anastas, Paul T.; And Others

    1985-01-01

    Background information and procedures used are provided for the synthesis of 4,5-diphenyl-methylimidazole. This experiment on the chemistry of heterocycles is ideally suited for beginning undergraduate organic chemistry students. (JN)

  8. Nitroblue tetrazolium blood test

    MedlinePlus

    ... chemical called nitroblue tetrazolium (NBT) into a deep blue color. ... Normally, the white blood cells turn blue when NBT is added. This means that the cells should be able to kill bacteria and protect the person ...

  9. 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.

  10. The response characteristics of tetrazolium violet solutions to gamma irradiation

    NASA Astrophysics Data System (ADS)

    Emi-Reynolds, G.; Kovács, András; Fletcher, J. J.

    2007-08-01

    The dosimetry characteristics of various solutions of tetrazolium violet, TV, (2,5-diphenyl-3-(1-naphthyl)-2H-tetrazolium chloride) to gamma irradiation are reported. The optical absorption spectra of these solutions show peaks between 400 and 600 nm with a shoulder at around 550 nm. The dose response of the optical absorbance values of aqueous and aqueous-alcoholic solutions containing different concentrations of TV was measured in the 250 Gy up to 75 kGy dose range. The formation of formazan product was observed due to radiolytic reduction in both solutions. Its formation was found more pronounced in N 2-saturated as well as in alkaline solutions. The results indicate that the 1 mM TV solution can be used for food irradiation and medical sterilization dosimetry at gamma irradiation facilities.

  11. Influence of medium acidity upon the luminescence properties of 2,5-diphenyl-1,3,4-oxadiazole and 2,5-diphenyl-1,3-oxazole

    NASA Astrophysics Data System (ADS)

    Trifonov, Rostislav E.; Rtishchev, Nikolai I.; Ostrovskii, Vladimir A.

    1996-12-01

    The luminescence properties of 2,5-diphenyl-1,3,4-oxadiazole and 2,5-diphenyl-1,3-oxazole in aqueous solutions of sulfuric acid (pH 7 to Ho - 10) were studied. The spectral parameters are essentially acidity dependent, which is due to the acid-base equilibria of these heterocycles both in the ground and in the first excited singlet states. The difference between these two compounds is governed by their dissimilar solvation. The basicity constants of 2,5-diphenyl-1,3,4-oxadiazole in the S0 state (p KBH+ = - 2.49) and 2,5-diphenyl-1,3-oxazole in the S0 and S1 states ( pK BH+ = -1.93, pK BH+∗ = 1.95) were experimentally obtained. The enthalpies of formation, electron charge density, and geometry of the bases and corresponding conjugate acids in the S0 and S1 states were calculated by the MNDO method.

  12. Theoretical and vibrational studies of 4,5-diphenyl-2-2 oxazole propionic acid (oxaprozin)

    NASA Astrophysics Data System (ADS)

    Sagdinc, Seda G.; Esme, Aslı

    2010-04-01

    The molecular structure, linear and nonlinear optical properties, and electronic properties of 4,5-diphenyl-2-2 oxazole propionic acid (oxaprozin) as a monomer were investigated by using Hartree-Fock (HF) and density functional theory (DFT) calculations that used 6-31G(d,p) basis set. The first-order hyperpolarizability of oxaprozin (OXA) was found to be 1.117 × 10 -30 esu. The structure of oxaprozin dimer with HF/6-31G(d) level caused by the shifts of O-H and C dbnd O bands in the vibrational spectra of oxaprozin were also studied. Moreover, these calculated frequencies of oxaprozin dimer were compared with the solid FT-IR and FT-Raman spectra. The theoretical frequencies and infrared intensities were showed a good agreement with experimental data.

  13. Structural and vibrational spectroscopy investigation of the 5-[(diphenyl) amino] isophthalic acid molecule

    NASA Astrophysics Data System (ADS)

    Kurt, M.; Şaş, E. Babur; Can, M.; Okur, S.; Icli, S.; Demic, S.

    2014-10-01

    The molecular structure and vibrations of 5-(diphenyl) amino] isophthalic acid (DPIFA) were investigated by different spectroscopic techniques (such as infrared and Raman). FT-IR, FT-Raman and dispersive Raman spectra were recorded in the solid phase. HOMO-LUMO analyses were performed. The theoretical calculations for the molecular structure and spectroscopic studies were performed with DFT (B3LYP) and 6-311G(d,p) basis set calculations using the Gaussian 09 program. After optimizing the geometry of the molecule, vibration wavenumbers and fundamental vibrations wavenumbers were assigned on the basis of the potential energy distribution (PED) of the vibrational modes calculated with VEDA 4 program. The results of theoretical calculations for the spectra of the title compound were compared with the observed spectra.

  14. Tetrazolium Oxidase Polymorphism in Rainbow Trout

    PubMed Central

    Cederbaum, Stephen D.; Yoshida, Akira

    1972-01-01

    Tetrazolium oxidase from the blood and liver of rainbow trout was found to be genetically polymorphic. The inheritance pattern of the liver enzyme was compatible only with a one locus-two allele hypothesis. The enzymes in the blood while having an electrophoretically identical polymorphism could differ genotypically from that of the liver in a given fish. The significance of these findings to the understanding of the evolution of the salmonid genome is discussed. PMID:4675090

  15. 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

  16. 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

  17. The tetrazolium-formazan system: design and histochemistry.

    PubMed

    Seidler, E

    1991-01-01

    Our increasing knowledge about the chemistry and the correlations between chemical structure and histochemical properties of the tetrazolium/formazan system is resulting in: a better understanding of existing histochemical tetrazolium techniques; the selection of optimal tetrazolium salts for qualified use in histochemistry, cytochemistry and biochemistry; both qualitative and quantitative improvements in histochemical techniques for purposes demonstrating the activities of various dehydrogenating enzymes; an extended insight into the "state" of the tested biological object by means of tetrazolium indicators with special properties; and the combination of histochemical enzyme determination with further morphological techniques. This article has attempted to illustrate the progress in the use of the tetrazolium/formazan-system for histochemical purposes.

  18. Use of an aqueous soluble tetrazolium/formazan assay for cell growth assays in culture.

    PubMed

    Cory, A H; Owen, T C; Barltrop, J A; Cory, J G

    1991-07-01

    A new tetrazolium analog of 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) was evaluated as a substitute for MTT in the microculture screening assay for in vitro cell growth. This new tetrazolium compound, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2- (4-sulfophenyl)-2H-tetrazolium, inner salt (MTS), in the presence of phenazine methosulfate (PMS), gave a water-soluble formazan product that had an absorbance maximum at 490-500 nm in phosphate-buffered saline. The amount of colored product formed was proportional to the number of cells and the time of incubation of the cells with MTS/PMS. MTS/PMS was reactive in all the cell lines tested which included mouse leukemia L1210 cells, mouse Ehrlich tumor cells, mouse 3T3 fibroblasts, and human colon tumor cells (HT-29). HT-29 and 3T3 fibroblasts reduced MTS/PMS more efficiently than they reduced MTT. Comparable to the amount of product formed from MTT, MTS/PMS gave excellent product formation. The IC50 value for pyrazoloimidazole obtained using MTS/PMS was 200 microM; for 5-fluoro-2'-deoxyuridine, the IC50 value was 0.9 nM. These values compared very favorably with the IC50 values obtained by direct cell counts. Further, the same IC50 values were obtained when the absorbances of the formazan product in the 96-well plates were determined after different times of incubation.

  19. Ipratropium bromide HFA.

    PubMed

    Wellington, Keri

    2005-01-01

    Ipratropium bromide is a nonselective antagonist of the muscarinic receptors located on airway smooth muscle, and is delivered via a metered-dose inhaler (MDI). Because of the requirement to phase out chlorofluorocarbon (CFC)-propelled MDIs, the ipratropium bromide inhalation aerosol MDI has been redesigned with a hydrofluoroalkane as the propellant (ipratropium bromide HFA). Ipratropium bromide HFA has recently been approved in the US for the maintenance treatment of bronchospasm associated with COPD. Ipratropium bromide HFA 42 microg four times daily (one dose [42 microg] is delivered via two puffs of the inhaler) demonstrated comparable efficacy to that of ipratropium bromide CFC 42 microg four times daily, as measured by spirometric testing, in a large, randomized, double-blind, placebo-controlled, 12-week trial in patients with stable COPD. Similarly, four-times-daily ipratropium bromide HFA 42 microg and ipratropium bromide CFC 42 microg provided a comparable degree of bronchodilation in patients with stable COPD during a 1-year, open-label study primarily designed to assess safety. In both studies, the tolerability profiles of ipratropium bromide HFA and ipratropium bromide CFC were comparable. The most common adverse events were related to respiratory system disorders. During the 1-year study, dry mouth was reported by 1.3% and 0.7% of patients in the ipratropium bromide HFA or ipratropium bromide CFC groups.

  20. Evaluation of a tetrazolium-based semiautomated colorimetric assay: assessment of radiosensitivity

    SciTech Connect

    Carmichael, J.; DeGraff, W.G.; Gazdar, A.F.; Minna, J.D.; Mitchell, J.B.

    1987-02-15

    Radiation survival curves were generated for V79 Chinese hamster and two human lung cancer cell lines (NCI-H460 and NCI-H249) with doubling times of 10, 20, and 85 h, respectively, using a standard clonogenic assay, a dye exclusion assay, and a semiautomated colorimetric assay utilizing a tetrazolium salt, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylformazan bromide. Comparable results for D0 and extrapolation number (n) were observed for all assays in the lines with doubling times of 10 and 20 h. In these instances the tumor cell lines had undergone seven or more doublings after radiation. For the tumor line (H249) with an 80-h doubling time the D0S were comparable between the assays while the extrapolation number was increased in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylformazan bromide assay, a result probably related to the lower number of doublings (less than 4) after radiation. We then tested the ability of the assays to detect radiation protection and sensitization using known agents. We found that cysteamine treatment resulted in radioprotection (by a factor of 8 at 8 Gy) while 5-bromo-2-deoxyuridine incorporation caused enhancement of radiation sensitivity in all three assays. We conclude that, while optimal conditions for each cell line (cell number plated and doubling time) must be established, using characterized tumor cell lines, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylformazan bromide assay could be automated and thus be of great value in screening large numbers of potential radiosensitizers or protectors.

  1. New visible and selective DNA staining method in gels with tetrazolium salts.

    PubMed

    Paredes, Aaron J; Naranjo-Palma, Tatiana; Alfaro-Valdés, Hilda M; Barriga, Andrés; Babul, Jorge; Wilson, Christian A M

    2017-01-15

    DNA staining in gels has historically been carried out using silver staining and fluorescent dyes like ethidium bromide and SYBR Green I (SGI). Using fluorescent dyes allows recovery of the analyte, but requires instruments such as a transilluminator or fluorimeter to visualize the DNA. Here we described a new and simple method that allows DNA visualization to the naked eye by generating a colored precipitate. It works by soaking the acrylamide or agarose DNA gel in SGI and nitro blue tetrazolium (NBT) solution that, when exposed to sunlight, produces a purple insoluble formazan precipitate that remains in the gel after exposure to light. A calibration curve made with a DNA standard established a detection limit of approximately 180 pg/band at 500 bp. Selectivity of this assay was determined using different biomolecules, demonstrating a high selectivity for DNA. Integrity and functionality of the DNA recovered from gels was determined by enzymatic cutting with a restriction enzyme and by transforming competent cells after the different staining methods, respectively. Our method showed the best performance among the dyes employed. Based on its specificity, low cost and its adequacy for field work, this new methodology has enormous potential benefits to research and industry.

  2. 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.

  3. Mercury Bromide Laser Research.

    DTIC Science & Technology

    1981-05-04

    Discharge", Optics Lett., 2(3), (March 1978). 7. R. Burnham, "Discharge Pumped Mercuric Halide Dissociation Lasers", Appl. Phys. Lett., 33: 15 (July 1978...laser and fluorescence signals. Neutral density filters served to prevent saturation of the detector during the laser measurements. F. Laser Output as a...REFERENCES . E. J. Schimitschek and J. E. Celto, " Mercuric Bromide Dissociation Laser in an Electric Discharge," Optics Lett. 2(3), March 1978. This

  4. 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.

  5. Study on the fluorescence properties of a new intramolecular charge transfer compound 1,5-diphenyl-3-( N-ethylcarbazole-3-yl)-2-pyrazoline

    NASA Astrophysics Data System (ADS)

    Li, J. F.; Guan, B.; Li, D. X.; Dong, C.

    2007-10-01

    The fluorescence properties of a newly synthesized compound, 1,5-diphenyl-3-( N-ethylcarbazole-3-yl)-2-pyrazoline (DEP) have been studied. On excitation at 352 nm, the fluorescence spectrum exhibits a large red shift with an increase in the polarity of solvents. The intensity of the band is different in different solvents as well. The change in the dipole moment in various solvents at room temperature has been characterized by the absorption and steady state fluorescence techniques and calculated based on the Lippert-Mataga equation. DEP has an increase of dipole moment of 2.83 D units on excitation to the lowest singlet state. It is concluded that photo-induced charge transfer from N (1) to C (3) actually exists in the excited state of the pyrazoline moiety. Its fluorescence property is relative to viscosity and temperature of solvents. The ϕf of DEP in neutral medium or basic medium is higher than acidic medium. In addition, when the concentration of DEP is higher than 10 -3 M, its fluorescence is quenched by the collision of each molecule. The red shift of the maximum emission of DEP attributes to the formation of aggregates and the conjugate system is strengthened.

  6. Managing Nematodes without Methyl Bromide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide is an effective pre-plant soil fumigant used to control nematodes in many high-input, high-value production systems including vegetables, nurseries, ornamentals, tree fruits, strawberries, and grapes. Because methyl bromide has provided a reliable return on investment for nematode c...

  7. 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.

  8. Evaluation of a soluble tetrazolium/formazan assay for cell growth and drug sensitivity in culture using human and other tumor cell lines.

    PubMed

    Scudiero, D A; Shoemaker, R H; Paull, K D; Monks, A; Tierney, S; Nofziger, T H; Currens, M J; Seniff, D; Boyd, M R

    1988-09-01

    We have previously described the application of an automated microculture tetrazolium assay (MTA) involving dimethyl sulfoxide solubilization of cellular-generated 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-formazan to the in vitro assessment of drug effects on cell growth (M.C. Alley et al., Proc. Am. Assoc. Cancer Res., 27:389, 1986; M.C. Alley et al., Cancer Res. 48:589-601, 1988). There are several inherent disadvantages of this assay, including the safety hazard of personnel exposure to large quantities of dimethyl sulfoxide, the deleterious effects of this solvent on laboratory equipment, and the inefficient metabolism of MTT by some human cell lines. Recognition of these limitations prompted development of possible alternative MTAs utilizing a different tetrazolium reagent, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl] -2H- tetrazolium hydroxide (XTT), which is metabolically reduced in viable cells to a water-soluble formazan product. This reagent allows direct absorbance readings, therefore eliminating a solubilization step and shortening the microculture growth assay procedure. Most human tumor cell lines examined metabolized XTT less efficiently than MTT; however, the addition of phenazine methosulfate (PMS) markedly enhanced cellular reduction of XTT. In the presence of PMS, the XTT reagent yielded usable absorbance values for growth and drug sensitivity evaluations with a variety of cell lines. Depending on the metabolic reductive capacity of a given cell line, the optimal conditions for a 4-h XTT incubation assay were 50 micrograms of XTT and 0.15 to 0.4 microgram of PMS per well. Drug profiles obtained with representative human tumor cell lines for several standard compounds utilizing the XTT-PMS methodology were similar to the profiles obtained with MTT. Addition of PMS appeared to have little effect on the metabolism of MTT. The new XTT reagent thus provides for a simplified, in vitro cell growth assay

  9. 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

  10. Radiolytic reactions of nitro blue tetrazolium under oxidative and reductive conditions: a pulse radiolysis study

    NASA Astrophysics Data System (ADS)

    Kovacs, A.; Wojnarovits, L.; Baranyai, M.; Moussa, A.; Othman, I.; McLaughlin, W. L.

    1999-08-01

    The radiolytic reactions of the ditetrazolium salt nitro blue tetrazolium chloride (NBTCl 2) were studied by pulse radiolysis technique in aqueous solution under reducing and oxidising conditions with the aim of potential dosimetry application. Under reducing conditions the fast formation of the tetrazolinyl radical is observed that is followed by the appearance of monoformazan (MF +), i.e. one of the tetrazolium rings is reduced to formazan. The formation of the water-insoluble diformazan, i.e. the result of the second reduction step was not observed in pulse radiolysis. Formazan formation was not found under oxidative conditions.

  11. Enhanced tetrazolium violet reduction of Salmonella spp. by magnesium addition to the culture media.

    PubMed

    Junillon, Thomas; Morand, Lucie; Flandrois, Jean Pierre

    2014-09-01

    Tetrazolium salts (TTZ), such as tetrazolium violet (TV), have been widely used for microbiological studies. The formation of the colored formazan product due to bacterial reduction of the uncolored reagent is extensively exploited to stain cells or colonies in agar or on filters. But an important toxic effect of tetrazolium salts on bacteria exists that limits their use at high concentrations, impairing the efficient staining of the colonies. This is especially the case for Salmonella spp. where we observed, using a classic photometric approach and mathematical modeling of the growth, an important impact of tetrazolium violet on the apparent growth rate below the inhibitory concentration. In this study, we demonstrate that adding magnesium to the medium in the presence of TV leads to a significant increase in the apparent growth rate. Moreover, when higher TV concentrations are used which lead to total inhibition of Salmonella strains, magnesium addition to the culture media allows growth and TV reduction. This effect of magnesium may allow the use of higher TTZ concentrations in liquid growth media and enhance bacteria detection capabilities.

  12. Bromide Adsorption by Reference Minerals and Soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bromide, Br-, adsorption behavior was investigated on amorphous Al and Fe oxide, montmorillonite, kaolinite, and temperate and tropical soils. Bromide adsorption decreased with increasing solution pH with minimal adsorption occurring above pH 7. Bromide adsorption was higher for amorphous oxides t...

  13. Ipratropium bromide-mediated myocardial injury in in vitro models of myocardial ischaemia/reperfusion.

    PubMed

    Harvey, Kate L; Hussain, Afthab; Maddock, Helen L

    2014-04-01

    Ipratropium bromide, a nonselective muscarinic antagonist, is widely prescribed for the treatment of chronic obstructive pulmonary disease (COPD). Analyses of COPD patients, with underlying ischaemic heart disease, receiving anticholinergics, have indicated increased risk of severity and occurrence of cardiovascular events (including myocardial infarction). The present study explored whether ipratropium bromide induces myocardial injury in nonclinical models of simulated myocardial ischaemia/reperfusion injury. Adult Sprague Dawley rat hearts/primary ventricular myocytes were exposed to simulated ischaemia/hypoxia prior to administration of ipratropium at the onset of reperfusion/reoxygenation. Infarct to risk ratio and cell viability was measured via triphenyl tetrazolium chloride staining and thiazolyl blue tetrazolium bromide (MTT) assay. The involvement of apoptosis and necrosis was evaluated by flow cytometry. Mitochondrial-associated responses were detected by tetramethylrhodamine methyl ester fluorescence and myocyte contracture. Ipratropium (1 × 10⁻¹¹ M - 1 × 10⁻⁴ M) significantly increased infarct/risk ratio and decreased cell viability in a dose-dependent manner. Increased levels of necrosis and apoptosis were observed via flow cytometry, accompanied by increased levels of cleaved caspase-3 following ipratropium treatment. Levels of endogenous myocardial acetylcholine were verified via use of an acetylcholine assay. In these experimental models, exogenous acetylcholine (1 × 10⁻⁷ M) showed protective properties, when administered alone, as well as abrogating the exacerbation of myocardial injury during ischaemia/reperfusion following ipratropium coadministration. In parallel experiments, under conditions of myocardial ischaemia/reperfusion, a similar injury was observed following atropine (1 × 10⁻⁷ M) administration. These data demonstrate for the first time in a nonclinical setting that ipratropium exacerbates ischaemia

  14. Synthesis, spectroscopic and theoretical studies of ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate butanol solvate.

    PubMed

    Koca, İrfan; Sert, Yusuf; Gümüş, Mehmet; Kani, İbrahim; Çırak, Çağrı

    2014-01-24

    We have synthesized ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate (2) by the reaction of 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonyl chloride (1), ammonium thiocyanate and ethyl 3-aminobut-2-enoate and then characterized by elemental analyses, IR, Raman, (1)H NMR, (13)C NMR and X-ray diffraction methods. The experimental and theoretical vibrational spectra of 2 were investigated. The experimental FT-IR (4000-400 cm(-1)) and Laser-Raman spectra (4000-100 cm(-1)) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles) were calculated using Ab Initio Hartree Fock (HF), Density Functional Theory (B3LYP) methods with 6-311++G(d,p) basis set by Gaussian 09W program. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. Also, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies were calculated.

  15. Synthesis, spectroscopic and theoretical studies of ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate butanol solvate

    NASA Astrophysics Data System (ADS)

    Koca, İrfan; Sert, Yusuf; Gümüş, Mehmet; Kani, İbrahim; Çırak, Çağrı

    2014-01-01

    We have synthesized ethyl (2E)-3-amino-2-({[(4-benzoyl-1,5-diphenyl-1H-pyrazol-3-yl)carbonyl]amino}carbonothioyl)but-2-enoate (2) by the reaction of 4-benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonyl chloride (1), ammonium thiocyanate and ethyl 3-aminobut-2-enoate and then characterized by elemental analyses, IR, Raman, 1H NMR, 13C NMR and X-ray diffraction methods. The experimental and theoretical vibrational spectra of 2 were investigated. The experimental FT-IR (4000-400 cm-1) and Laser-Raman spectra (4000-100 cm-1) of the molecule in the solid phase were recorded. Theoretical vibrational frequencies and geometric parameters (bond lengths, bond angles) were calculated using Ab Initio Hartree Fock (HF), Density Functional Theory (B3LYP) methods with 6-311++G(d,p) basis set by Gaussian 09W program. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. The assignments of the vibrational frequencies were performed by potential energy distribution (PED) analysis by using VEDA 4 program. The theoretical optimized geometric parameters and vibrational frequencies were compared with the corresponding experimental X-ray diffraction data, and they were seen to be in a good agreement with each other. Also, the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energies were calculated.

  16. Use of a soluble tetrazolium/formazan assay for chicken cells.

    PubMed

    Tajima, T; Hironao, T; Kajikawa, T; Kawamura, H

    1992-12-01

    We evaluated a soluble tetrazolium/formazan assay using 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)-carbonyl ]-2H- tetrazolium hydroxide (XTT) for chicken cell growth. Fifty microliter of solution containing 1 mg/ml of XTT and 0.025 mM phenazine methosulfate was added to the cells in a well of 96-well microplate. After 4 hr incubation at 37 degrees C, the absorbance was measured at 490 nm. Under this condition, absorbances were well correlated with cell number of Marek's disease tumor cells and chicken embryo fibroblasts. Proliferation of chicken lymphocytes stimulated with mitogens was also effectively measured. The formazan of XTT is water-soluble and can be quantitated in culture medium without the necessity for extraction with organic solvents. Thus XTT assay is simple and useful for the quantity assay with chicken cells.

  17. Copper ions interfere with the reduction of the water-soluble tetrazolium salt-8.

    PubMed

    Semisch, Annetta; Hartwig, Andrea

    2014-02-17

    Metabolic activity as a measure of cell viability is frequently determined using the water-soluble tetrazolium salt 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt (WST-8), commercially available as CCK-8 reagent. In this study, CCK-8 was investigated with respect to its suitability for investigating nano- and microscale copper oxide (CuO NP and CuO MP) as well as water-soluble copper chloride (CuCl2). The results were compared to cell number and colony forming ability. Our data demonstrate that the CCK-8 assay overestimates the loss of metabolic activity by CuCl2 and CuO NP, because of interference by copper ions with the reduction of the dye.

  18. Substrate-Specific Reduction of Tetrazolium Salts by Isolated Mitochondria, Tissues, and Leukocytes.

    PubMed

    Fedotcheva, N I; Litvinova, E G; Zakharchenko, M V; Khunderyakova, N V; Fadeev, R S; Teplova, V V; Fedotcheva, T A; Beloborodova, N V; Kondrashova, M N

    2017-02-01

    Tetrazolium salts are commonly used in cytochemical and biochemical studies as indicators of metabolic activity of cells. Formazans, formed by reduction of tetrazolium salts, behave as pseudo-solutions during initial incubation, which allows monitoring their optical density throughout incubation. The criteria and conditions for measuring oxidative activity of mitochondria and dehydrogenase activity in reduction of nitroblue tetrazolium (NBT) and methyl thiazolyl tetrazolium (MTT) in suspensions of isolated mitochondria, tissue homogenates, and leukocytes were investigated in this work. We found that the reduction of these two acceptors depended on the oxidized substrate - NBT was reduced more readily during succinate oxidation, while MTT - during oxidation of NAD-dependent substrates. Reduction of both acceptors was more sensitive to dehydrogenase inhibitors that to respiratory chain inhibitors. The reduction of NBT in isolated mitochondria, in leukocytes in the presence of digitonin, and in liver and kidney homogenates was completely blocked by succinate dehydrogenase inhibitors - malonate and TTFA. Based on these criteria, activation of succinate oxidation was revealed from the increase in malonate-sensitive fraction of the reduced NBT under physiological stress. The effect of progesterone and its synthetic analogs on oxidation of NAD-dependent substrates by mitochondria was investigated using MTT. Both acceptors are also reduced by superoxide anion; the impact of this reaction is negligible or completely absent under physiological conditions, but can become detectable on generation of superoxide induced by inhibitors of individual enzyme complexes or in the case of mitochondrial dysfunction. The results indicate that the recording of optical density of reduced NBT and MTT is a highly sensitive method for evaluation of metabolic activity of mitochondria applicable for different incubation conditions, it offers certain advantages in comparison with other methods

  19. Lifetime broadening in the rotationally resolved electronic spectra of dibenzothiophene, 2,5-diphenylfuran, and 2,5-diphenyl-1,3,4-oxadiazole in the gas phase. Intersystem crossing dynamics in the statistical limit.

    PubMed

    Alvarez-Valtierra, Leonardo; Yi, John T; Pratt, David W

    2009-03-19

    The fluorescence lifetime of the zero point vibrational level of the first excited electronic state of dibenzothiophene (DBT) has been determined to be 1.0 ns by analysis of its rotationally resolved S1 <-- S0 fluorescence excitation spectrum. The S1 lifetime of DBT is substantially shorter than those observed for fluorene (FLU), carbazole (CAR), and dibenzofuran (DBF), analogs of DBT in which the heavy sulfur atom is replaced by lighter ones. The electronic origin bands through the series CAR, FLU, DBF, and DBT exhibit a monotonic increase in Lorentzian broadening in their Voigt line shape profiles. Two other heterocyclic molecules manifest similar photophysical properties; 2,5-diphenylfuran and 2,5-diphenyl-1,3,4-oxadiazole. Lorentzian line shape broadenings of approximately 76 MHz were observed in the high-resolution spectra of their origin bands. Possible reasons for the short fluorescence lifetimes of these heterocycles are discussed.

  20. A N-(2-hydroxyethyl)piperazine dangled 2,5-diphenyl-1,3,4-oxadiazole-based fluorescent sensor for selective relay recognition of Cu(2+) and sulfide in water.

    PubMed

    Tang, Lijun; Zheng, Zhuxuan; Bian, Yanjiang

    2016-12-01

    A new 2,5-diphenyl-1,3,4-oxadiazole-based derivative (L) was synthesized and applied as a highly selective and sensitive fluorescent sensor for relay recognition of Cu(2+) and S(2-) in water (Tris-HCl 10 mM, pH = 7.0) solution. L exhibits an excellent selectivity to Cu(2+) over other examined metal ions with a prominent fluorescence 'turn-off' at 392 nm. L interacts with Cu(2+) through a 1:2 binding stoichiometry with a detection limit of 4.8 × 10(-7) M. The on-site formed L-2Cu(2+) complex exhibits excellent selectivity to S(2-) with a fluorescence 'off-on' response via a Cu(2+) displacement approach. Copyright © 2016 John Wiley & Sons, Ltd.

  1. 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.

  2. 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.

  3. Surface and volume properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide I. Surface properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide.

    PubMed

    Harkot, Joanna; Jańczuk, Bronisław

    2009-03-15

    Surface tension measurements were carried out for aqueous solutions of two cationic surfactants: dodecylethyldimethylammonium bromide (C(12)(EDMAB)) and benzyldimethyldodecylammonium bromide (BDDAB). Isotherms and thermodynamic adsorption parameters were determined from the surface tension data. Firstly, the surface excess concentration in the adsorbed monolayer and the total concentration of the surfactants were determined, then the standard free energy of adsorption was calculated by different methods. In the calculations, different orientations of the surfactants at the adsorbed monolayer were also taken into account. From the experimental and calculated data it results that the difference in the structure of the two cationic surfactants by changing the methyl group for aryl one in their heads causes an increase of the efficiency and a decrease of the effectiveness of adsorption at water-air interface, and that the standard free energy of adsorption can be predicted from the surface tension of the surfactants assuming the aryl group to be equivalent to 3.5 methylene groups. The experimentally obtained difference between the standard free energy of adsorption of the C(12)(EDMAB) and BDDAB was in good agreement with that theoretically accounted, corresponding to the standard free energy of adsorption of the aryl group. However, the best correlation between the values was obtained when a parallel orientation of the surfactant molecules at the adsorbed monolayer was taken into account.

  4. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be...) Bromoacetone, methyl bromide, chloropicrin and methyl bromide mixtures, chloropicrin and methyl...

  5. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be... Group I performance level. (b) Bromoacetone, methyl bromide, chloropicrin and methyl bromide...

  6. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be...) Bromoacetone, methyl bromide, chloropicrin and methyl bromide mixtures, chloropicrin and methyl...

  7. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... methyl bromide or methyl chloride mixtures, etc. 173.193 Section 173.193 Transportation Other Regulations... bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc. (a) Bromoacetone must be... Group I performance level. (b) Bromoacetone, methyl bromide, chloropicrin and methyl bromide...

  8. 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.

  9. Neurological manifestation of methyl bromide intoxication.

    PubMed

    Suwanlaong, Kanokrat; Phanthumchinda, Kammant

    2008-03-01

    Methyl bromide is a highly toxic gas with poor olfactory warning properties. It is widely used as insecticidal fumigant for dry foodstuffs and can be toxic to central and peripheral nervous systems. Most neurological manifestations of methyl bromide intoxication occur from inhalation. Acute toxicity characterized by headache, dizziness, abdominal pain, nausea, vomiting and visual disturbances. Tremor, convulsion, unconsciousness and permanent brain damage may occur in severe poisoning. Chronic exposure can cause neuropathy, pyramidal and cerebellar dysfunction, as well as neuropsychiatric disturbances. The first case of methyl bromide intoxication in Thailand has been described. The patient was a 24-year-old man who worked in a warehouse of imported vegetables fumigated with methyl bromide. He presented with unstable gait, vertigo and paresthesia of both feet, for two weeks. He had a history of chronic exposure to methyl bromide for three years. His fourteen co-workers also developed the same symptoms but less in severity. Neurological examination revealed ataxic gait, decreased pain and vibratory sense on both feet, impaired cerebellar signs and hyperactive reflex in all extremities. The serum concentration of methyl bromide was 8.18 mg/dl. Electrophysilogical study was normal. Magnetic resonance imaging of the brain (MRI) revealed bilateral symmetrical lesion of abnormal hypersignal intensity on T2 and fluid-attenuation inversion recovery (FLAIR) sequences at bilateral dentate nuclei of cerebellum and periventricular area of the fourth ventricle. This incident stresses the need for improvement of worker education and safety precautions during all stages of methyl bromide fumigation.

  10. Surface and volume properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide: II. Volumetric properties of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide.

    PubMed

    Harkot, Joanna; Jańczuk, Bronisław

    2009-02-15

    Density measurements were carried out for aqueous solutions of two cationic surfactants: dodecylethyldimethylammonium bromide (C(12)(EDMAB)) and benzyldimethyldodecylammonium bromide (BDDAB). On the basis of the obtained results of the measurements the CMC and partial molar volumes of the surfactants studied were also determined. The obtained CMC values were also analyzed with those accounted on the basis of the surface tension data from the previous paper [J. Harkot, B. Jańczuk, J. Colloid Interface Sci. (2008), submitted for publication]. The values of CMC determined from the surface tension and density measurements for C(12)(EDMAB) are equal to 9.9x10(-3) and 1.5x10(-2) M and for BDDAB to 5.25x10(-3) and 5.3x10(-3) M, respectively. These obtained values are very similar. However, in the literature it is difficult to find the CMC values for C(12)(EDMAB) and BDDAB determined by these two methods used by us-especially from the density measurements for BDDAB and surface tension measurements for C(12)(EDMAB). In the case of the apparent molar volumes of C(12)(EDMAB) there is a good agreement between the values obtained by us and those found in the literature. The CMC values for C(12)(EDMAB) and BDDAB were also determined on the basis of their surface tension and free energy of electrostatic interactions between the polar heads of these surfactants and compared with those obtained from the surface tension and density measurements. It was found that the theoretically obtained CMC values were close to those determined from the density and surface tension data for the C(12)(EDMAB) and that the ratios of the CMC values of the surfactants to their concentration at which the water surface tension decreased by about 20 mN/m proved that the presence of the aryl group in the BDDAB head instead of the methyl group caused that its micellization process was more inhibited in relation to its adsorption at air-water interface than that of C(12)(EDMAB).

  11. Synthesis, molecular structure, DFT studies and antimicrobial activities of some novel 3-(1-(3,4-dimethoxyphenethyl)-4,5-diphenyl-1H-imidazol-2-yl)-1H-indole derivatives and its molecular docking studies

    NASA Astrophysics Data System (ADS)

    Rajaraman, D.; Sundararajan, G.; Loganath, N. K.; Krishnasamy, K.

    2017-01-01

    A new series of 3-(1-(3,4-dimethoxyphenethyl)-4,5-diphenyl-1H-imidazol-2-yl)-1H-indole derivatives (5a-5j) are conveniently synthesized and characterized by IR, 1H NMR and 13C NMR spectral techniques. The compound 5f was also confirmed by single crystal XRD analysis and optimized bond parameters were calculated by density functional theory (DFT) at B3LYP/6-31G (d, p) level. The optimized geometrical parameters obtained by DFT calculation are in good agreement with single crystal XRD data. The experimentally observed FT-IR and FT-Raman bands were assigned to different normal modes of the molecule. The stability and charge delocalization of the molecule were also studied by Natural Bond Orbital (NBO) analysis. The overlapping of atomic orbital along with their predicted energy is explained on the basis of HOMO-LUMO energy gap calculations. Molecular Electrostatic Potential map (MEP) was studied for predicting the reactive sites. The reported molecule used as a potential NLO material since it has high μβ0 value. The antibacterial activities of these derivatives were studied using molecular docking studies and it is compared with their experimental results.

  12. Radiation-chemical reaction of 2,3,5-triphenyl-tetrazolium chloride in liquid and solid state

    NASA Astrophysics Data System (ADS)

    Kovács, A.; Wojnárovits, L.; McLaughlin, W. L.; Eid, S. E. Ebrahim; Miller, A.

    1996-03-01

    In pulse radiolysis of 2,3,5-triphenyl-tetrazolium chloride (TTC) at around 360 nm fast formation of intermediate tetrazolium radical was observed under both oxidizing and reducing conditions. In the latter case bimolecular formation of formazan, absorbing at around 480 nm, was observed. This reaction is accompanied by combination to the diformazan dimer, absorbing over the spectral range 500-550 nm. A polyvinyl-alcohol-based TTC film was produced and tested for dosimetry purposes: it gave a measurable response in the 1-100 kGy dose range by evaluating the 50 μm thick TTC films at the absorption maximum of 493 nm.

  13. Growth and characterization of lead bromide crystals

    NASA Technical Reports Server (NTRS)

    Singh, N. B.; Gottlieb, M.; Henningsen, T.; Hopkins, R. H.; Mazelsky, R.; Glicksman, M. E.; Coriell, S. R.; Santoro, G. J.; Duval, W. M. B.

    1992-01-01

    Lead(II) bromide was purified by a combination of directional freezing and zone-refining methods. Differential thermal analysis of the lead bromide showed that a destructive phase transformation occurs below the melting temperature. This transformation causes extensive cracking, making it very difficult to grow a large single crystal. Energy of phase transformation for pure lead bromide was determined to be 24.67 cal/g. To circumvent this limitation, crystals were doped by silver bromide which decreased the energy of phase transformation. The addition of silver helped in achieving the size, but enhanced the inhomogeneity in the crystal. The acoustic attenuation constant was almost identical for the pure and doped (below 3000 ppm) crystals.

  14. 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.

  15. 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...

  16. Effects of nitroblue tetrazolium and vitamin E on platelet ultrastructure, aggregation, and secretion

    PubMed Central

    White, James G.; Rao, Gundu H. R.; Gerrard, Jonathan M.

    1977-01-01

    All agents capable of triggering the platelet release reaction also stimulate prostaglandin biosynthesis in these cells. Information concerning the endoperoxides, thromboxanes, and more stable metabolites generated by the action of cyclooxygenase and lipoxygenase on arachidonic acid has accumulated rapidly, but little is known about the preliminary steps in the cleavage and preparation of arachidonic acid for insertion into the enzymatic pathways of prostaglandin synthesis. Studies in this laboratory have shown that the combination of nitroblue tetrazolium (NBT) and vitamin E which prevents oxygenation of arachidonic acid to a free radical also blocks platelet prostaglandin biosynthesis. The present study has evaluated the influence of NBT, vitamin E, and the combination of NBT and vitamin E on the fine structure and biochemistry of platelets during incubation, and the effects of these compounds on the aggregation and secretion of platelets stimulated by collagen, thrombin, epinephrine, and ADP. Results of the study demonstrate that NBT and vitamin E, rather than injuring platelets, appear to protect them during incubation. Together NBT and vitamin E blocked aggregation by epinephrine, collagen, and thrombin, but permitted a small first wave stimulated by ADP. Both ADP and thrombin induced shape change, pseudopod formation, and limited degrees of internal contraction in vitamin E-NBT-treated platelets, whereas epinephrine and collagen failed to significantly alter discoid form. This pattern of response to aggregating agents was identical to reactions observed in platelets pretreated with aspirin and indomethacin, both potent inhibitors of platelet prostaglandin synthesis. In addition, NBT-vitamin E virtually blocked the first wave of aggregation which is not affected by aspirin and indomethacin. The findings support the concept that conversion of arachidonic acid to an activated state is an important step in prostaglandin synthesis and that electron transfer or

  17. Nitroblue tetrazolium blocks BK channels in cerebrovascular smooth muscle cell membranes

    PubMed Central

    Ye, D; Pospisilik, J A; Mathers, D A

    2000-01-01

    The effects of p-nitroblue tetrazolium (NBT) on large conductance, calcium-activated potassium channels (BK channels) in enzymatically dispersed rat cerebrovascular smooth muscle cells (CVSMCs) were examined. Patch clamp methods were employed to record single BK channel currents from inside-out patches of CVMC membrane maintained at 21–23°C. When applied to the cytoplasmic face of inside-out membrane patches (internally applied NBT), micromolar concentrations of NBT reversible reduced the mean open time of BK channels, without changing channel conductance. NBT altered the frequency distribution of BK channel open times from a two exponential to a single exponential form. In the absence of NBT, mean channel open time increased on membrane depolarization. In the presence of internally applied NBT, mean channel open became essentially independent of membrane potential. Internally applied NBT also reduced the mean closed time of BK channels when measured at membrane potentials in the range −80 mV to +20 mV. The combined effects of internal NBT on mean open and closed times resulted in the suppression of BK channel open probability when measured at positive membrane potentials. When applied to the external membrane face, micromolar concentrations of NBT reduced mean channel open time progressively as the membrane was hyperpolarized, and also reduced open probability at negative membrane potentials. A model is proposed in which NBT alters channel gating by binding to a site at or near to the cytoplasmic membrane face. Externally applied NBT suppressed BK channel open probability at concentrations which also inhibit nitric oxide synthase (NOS). Therefore, the potential role of potassium channel block in NBT actions previously attributed to NOS inhibition is discussed. PMID:10696106

  18. A novel 3-(4,5-diphenyl-1,3-oxazol-2-yl)propanal oxime compound is a potent Transient Receptor Potential Ankyrin 1 and Vanilloid 1 (TRPA1 and V1) receptor antagonist.

    PubMed

    Payrits, M; Sághy, É; Mátyus, P; Czompa, A; Ludmerczki, R; Deme, R; Sándor, Z; Helyes, Zs; Szőke, É

    2016-06-02

    Transient Receptor Potential Ankyrin 1 and Vanilloid 1 (TRPA1, TRPV1) ion channels expressed on nociceptive primary sensory neurons are important regulators of pain and inflammation. TRPA1 is activated by several inflammatory mediators including formaldehyde and methylglyoxal that are products of the semicarbazide-sensitive amine-oxidase enzyme (SSAO). SZV-1287 is a new 3-(4,5-diphenyl-1,3-oxazol-2-yl)propanal oxime SSAO inhibitor, its chemical structure is similar to other oxime derivatives described as TRPA1 antagonists. Therefore, we investigated its effects on TRPA1 and TRPV1 receptor activation on the cell bodies and peripheral terminals of primary sensory neurons and TRPA1 or TRPV1 receptor-expressing cell lines. Calcium influx in response to the TRPA1 agonist allyl-isothiocyanate (AITC) (200 μM) and the TRPV1 stimulator capsaicin (330 nM) in rat trigeminal neurons or TRPA1 and TRPV1 receptor-expressing cell lines was measured by microfluorimetry or radioactive (45)Ca(2+) uptake experiments. Calcitonin gene-related peptide (CGRP) release as the indicator of 100 μM AITC - or 100 nM capsaicin-induced peripheral sensory nerve terminal activation was measured by radioimmunoassay. SZV-1287 (100, 500 and 1000 nM) exerted a concentration-dependent significant inhibition on both AITC- and capsaicin-evoked calcium influx in trigeminal neurons and TRPA1 or TRPV1 receptor-expressing cell lines. It also significantly inhibited the TRPA1, but not the TRPV1 activation-induced CGRP release from the peripheral sensory nerve endings in a concentration-dependent manner. In contrast, the reference SSAO inhibitor LJP 1207 with a different structure had no effect on TRPA1 or TRPV1 activation in either model system. This is the first evidence that our novel oxime compound SZV-1287 originally developed as a SSAO inhibitor has a potent dual antagonistic action on TRPA1 and TRPV1 ion channels on primary sensory neurons.

  19. Effects of molecular oxygen on detection of superoxide radical with nitroblue tetrazolium and on activity stains for catalase

    SciTech Connect

    Clare, D.A.; Duong, M.N.; Darr, D.; Archibald, F.; Fridovich, I.

    1984-08-01

    The usual method of staining polyacrylamide gel electropherograms for superoxide dismutase activity utilizes a photochemical flux of O/sub 2//sup -/ to reduce nitroblue tetrazolium. Superoxide dismutases intercept O/sub 2//sup -/, preventing formazan production and thus causing achromatic bands. In the presence of H/sub 2/O/sub 2/, catalase also yield achromatic bands during this staining procedure. This is due to local elevation of pO/sub 2/ by the catalytic decomposition of H/sub 2/O/sub 2/. O/sub 2/, in turn, inhibits the reduction of the tetrazolium by O/sub 2//sup -/. This phenomenon provides a new activity stain for catalase. A previously described activity stain for catalase has also been reexamined and significantly improved.

  20. METHYL BROMIDE ALTERNATIVES FOR CALIFORNIA STRAWBERRY NURSERIES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects of methyl bromide (MB) alternative fumigants on soil pests, plant productivity in nursery and fruiting fields, as well as production costs, were evaluated in California strawberry nurseries by an interdisciplinary team. Our trials followed nursery stock through low and high elevation ph...

  1. 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.

  2. Cherry angiomas associated with exposure to bromides.

    PubMed

    Cohen, A D; Cagnano, E; Vardy, D A

    2001-01-01

    Cherry angiomas are the most common vascular proliferation; however, little is known about the pathogenesis and etiology of these lesions. We present two laboratory technicians who were exposed to brominated compounds for prolonged periods and who developed multiple cherry angiomas on the trunk and extremities. We suggest that the association between exposure to bromides and cherry angiomas should be investigated by a controlled study.

  3. Methyl Bromide Investigation Expands to Puerto Rico

    EPA Pesticide Factsheets

    (New York, N.Y.) The U.S. Environmental Protection Agency, working with the Virgin Islands government, is investigating the March 2015 incident involving the use of a pesticide containing methyl bromide to fumigate a residence at the Sirenusa apartments on

  4. Use of an aqueous soluble tetrazolium/formazan assay to measure viability and proliferation of lymphokine-dependent cell lines.

    PubMed

    Buttke, T M; McCubrey, J A; Owen, T C

    1993-01-04

    A new tetrazolium compound, MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3- carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt), has recently been described which in the presence of phenazine methosulfate (PMS) is reduced by living cells to yield a formazan product that can be assayed colorimetrically. An important advantage of MTS/PMS over other tetrazolium dyes (e.g., MTT) is the aqueous solubility of the reduced formazan product which eliminates the need for detergent solubilization or organic solvent extraction steps. Its advantages over XTT/PMS, another tetrazolium which yields a water-soluble formazan product, include the absorbance range of color produced (515-580 nm as opposed to 450 nm), the rapidity of color development, and the storage stability of the MTS/PMS reagent solution. In the present study, MTS/PMS was used to assay viability and proliferation of the IL-2-dependent HT-2 and CTLL-2 cell lines and the IL-3-dependent FDC-P1 and FL5.12 cell lines. With each cell line, the amount of formazan product was time-dependent and proportional to the number of viable cells. Furthermore, with both HT-2 and CTLL-2 cells it was found that cultures could be simultaneously labeled with MTS/PMS and [3H]thymidine, with relatively little effect of the dye on uptake of the latter. This feature was further capitalized upon in studies with FDC-P1 cells, in which the co-addition of MTS/PMS and [3H]thymidine was used to distinguish between cell viability and proliferation.

  5. Aqueous soluble tetrazolium/formazan MTS as an indicator of NADH- and NADPH-dependent dehydrogenase activity.

    PubMed

    Dunigan, D D; Waters, S B; Owen, T C

    1995-10-01

    Recently a new tetrazolium was described for the use of monitoring cell viability in culture. This tetrazolium, commonly referred to as MTS [3-(4,5-dimethylthiazol-2-yl)- 5-(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt], has the unusual property that it can be reduced to a water-soluble formazan. beta-Nicotinamide adenine dinucleotide/reduced (NADH) and beta-nicotinamide adenine dinucleotide phosphate/reduced (NADPH) are examples of physiologically important reducing agents. In cell-free studies, MTS was reduce to the soluble formazan in the presence of NADH and NADPH, and reaction were compared to those with dithiothreitol (DTT) or 2-mercaptoethanol (2-ME). The efficiency of these reactions was enhanced 1000-fold by the presence of phenazine methosulfate. Selectivity in the electron transfer from NADPH was slightly greater than NADH, and NADPH or NADH was much greater than the thiols DTT or 2-ME. Generation of either NADH or NADPH in solution by malate dehydrogenase or isocitrate dehydrogenase, respectively, was monitored by the MTS reduction reaction. The rate of formazan formation was comparable to the formation of NADH or NADPH. This system represents a useful tool for evaluating reaction kinetics in solutions of NAD- or NADP-dependent dehydrogenase enzymes, and these reactions can be performed in typical biological buffers containing reducing agents without significant interference to the MTS/formazan system.

  6. 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.

  7. 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

  8. Thallium bromide iodide crystal acoustic anisotropy examination.

    PubMed

    Mantsevich, S N

    2017-03-01

    Thallium bromide iodide crystal also known as KRS-5 is the well known material used in far infrared radiation applications for optical windows and lenses fabrication. The main advantage of this material is the transparency in wide band of wavelengths from 0.53 to 50μm. Despite such advantages as transparency and large acousto-optic figure of merit values, KRS-5 is rarely used in acousto-optics. Nevertheless this material seems to be promising for far infrared acousto-optic applications. The acoustic and acousto-optic properties of KRS-5 needed for the full use in optoelectronics are not well understood to date. In this paper the detailed examination of thallium bromide iodide crystal acoustic properties is presented.

  9. Data for methyl bromide decon testing

    EPA Pesticide Factsheets

    Spreadsheets containing data for recovery of spores from different materials. Data on the fumigation parameters are also included.This dataset is associated with the following publication:Wood , J., M. Wendling, W. Richter, A. Lastivka, and L. Mickelsen. Evaluation of the Efficacy of Methyl Bromide in the Decontamination of Building and Interior Materials Contaminated with Bacillus anthracis Spores. APPLIED AND ENVIRONMENTAL MICROBIOLOGY. American Society for Microbiology, Washington, DC, USA, 1-28, (2016).

  10. Ipratropium bromide in children with asthma.

    PubMed Central

    Mann, N P; Hiller, E J

    1982-01-01

    Eighteen children between 6 and 14 years of age with perennial asthma were studied over two four-week treatment periods. Ipratropium bromide, given in addition to their current treatment, was compared with placebo using a double-blind crossover technique. The period of treatment with ipratropium was associated with a significant reduction in symptoms during both day and night and significantly higher morning peak expiratory flow rates. PMID:6461943

  11. 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.

  12. [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.

  13. 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.

  14. 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.

  15. The neurological effects of methyl bromide intoxication.

    PubMed

    de Souza, Aaron; Narvencar, Kedareshwar P S; Sindhoora, K V

    2013-12-15

    Used primarily as a fumigant or as a substrate in chemical processes, methyl bromide is a highly toxic gas. The gas is usually absorbed by inhalation and effects on the lungs, gastrointestinal tract, skin, and brain are seen. Numerous instances of acute and chronic neurologic injury have been reported: acute poisoning results in seizures, myoclonus, ataxia or cerebral oedema beginning as early as 30 min after exposure while subacute or chronic intoxication presents with diverse slowly progressive neurological and neurobehavioral symptoms. Serum bromide levels may be elevated, but often return rapidly to normal. Electroencephalography may show frontally-predominant slow waves or polyspikes with following slow wave, and MRI reveals characteristic involvement in the dentate nucleus of the cerebellum, the brainstem, and the splenium of the corpus callosum. Symmetric and selective lesions in characteristic sites are observed on imaging and on histopathological examination. These are likely produced by methylation of intracellular lipids, protein and glutathione; production of toxic metabolites; defective neurotransmitter function; and abnormal oxidative phosphorylation. This article reviews the toxic effects of this gas, the pathophysiology and symptoms of its effects on the nervous system, and characteristic findings on MRI; and presents an illustrative case of methyl bromide intoxication due to exposure at a factory producing the compound commercially.

  16. Tetrazolium-based assays for cellular viability: a critical examination of selected parameters affecting formazan production.

    PubMed

    Vistica, D T; Skehan, P; Scudiero, D; Monks, A; Pittman, A; Boyd, M R

    1991-05-15

    The hydrogen acceptor 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) is commonly utilized to estimate cellular viability in drug screening protocols. The present investigation was prompted, in part, by observations that reduction of MTT to its colored reaction product, MTT formazan, varied between cell lines and with culture age. A correlation was established between the D-glucose concentration of the culture medium at the time of assay and the production of MTT formazan for cell lines representing seven tumor histologies. A decrease in the concentration of D-glucose from culture medium was accompanied by a decrease in MTT specific activity (MTT formazan/microgram cell protein) for a number of cell lines. Cells which extensively metabolized D-glucose exhibited the greatest reduction in MTT specific activity. Further evidence that the D-glucose concentration of the culture medium played an important role in MTT reduction was provided by experiments which demonstrated that transfer of cells to a glucose-free medium (L-15) was accompanied by an immediate decrease in MTT reduction which was pH independent. These studies suggested that cellular transport and constant metabolism of glucose were required for maximum MTT reduction. Decreases in the cellular concentration of the reduced pyridine nucleotides NADH and NADPH were accompanied by concomitant decreases in MTT formazan production. MTT formazan varied significantly among cell lines in both the kinetics of its formation and the degree of saturability exhibited. Apparent IC50 values for Adriamycin varied, in a cell line-specific manner, with MTT exposure time. These results indicate that MTT specific activity is significantly influenced by a number of parameters and suggest that assay conditions should be established which minimize their effects.

  17. Evaluation of tetrazolium-based semiautomatic colorimetric assay for measurement of human antitumor cytotoxicity

    SciTech Connect

    Heo, D.S.; Park, J.G.; Hata, K.; Day, R.; Herberman, R.B.; Whiteside, T.L. )

    1990-06-15

    A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based colorimetric assay was developed and compared with 51Cr release from different adherent tumor cell targets (human squamous cell carcinoma lines of the head and neck established in our laboratory, melanoma, and colorectal carcinoma) using 5-7-day human lymphokine-activated killer cells and monocyte-depleted peripheral blood lymphocytes as effectors. With adherent tumor cell targets, MTT colorimetry was more sensitive than the 51Cr release assay in measuring the antitumor activity of effectors: median, 4385 (range, 988-8144) versus median, 1061 (range, 582-7294) lytic units (the number of effector cells required to lyse 20% of 5 x 10(3) targets)/10(7) effectors (P less than 0.01). Background effects (without effector cells) were comparable in 4-h assays (9% versus 10%) between MTT colorimetry and 51Cr release. In 24-h assays, MTT colorimetry showed higher antitumor activity (70-100% versus 40-60% lysis at 1:1 effector:target cell ratio) but lower background effects (6% versus 38%) than 51Cr release assay. Thus, MTT colorimetry was more sensitive, did not use radiolabeled targets, required fewer effector cells, and was easier, less expensive, and better adaptable to serial monitoring of effector cell function in cancer patients. This colorimetric assay is especially well suited to adherent tumor cell targets. The use of adherent tumor cell monolayers, as opposed to trypsinized single cell suspensions, provides an opportunity to measure interactions of effector cells with enzymatically unaltered solid tumor targets. Because of the greater sensitivity of the colorimetric assay, the transformation of MTT data into lytic units, as commonly used for 51Cr release assays, required an adjustment to avoid the extrapolation based on the exponential fit equation.

  18. Application of a tetrazolium salt with a water-soluble formazan as an indicator of viability in respiring bacteria.

    PubMed

    Roslev, P; King, G M

    1993-09-01

    The tetrazolium salt sodium 3'-{1-[(phenylamino)-carbonyl]-3,4-tetrazolium}-bis (4-methoxy-6-nitro)benzene-sulfonic acid hydrate (XTT) was examined for use as a colorimetric indicator of viability in respiring bacteria. XTT was reduced to an orange, water-soluble formazan product by Methylosinus trichosporium OB3b, Pseudomonas putida, Escherichia coli, and Bacillus subtilis. Formazan production was proportional to live cell biomass, and XTT was reduced by all cultures in the absence of added electron-coupling agents. XTT reduction by M. trichosporium OB3b was linear over several hours and was stimulated by the presence of an exogenous substrate (methanol). Addition of cyanide to cultures incubated under oxic conditions gave an initial 10-fold increase in XTT reduction. Viability of bacteria incubated in the absence of exogenous carbon substrates was measured as XTT reduction and compared with viability estimates from plate counts. Results obtained with the two methods were generally comparable, but the XTT assay was superior when cell recovery on plates was low. Incubation of E. coli for 7 days in the absence of exogenous carbon substrates decreased viability by 90%, whereas the corresponding decreases for cultures of M. trichosporium OB3b, P. putida, and B. subtilis were less than 40%.

  19. Application of a Tetrazolium Salt with a Water-Soluble Formazan as an Indicator of Viability in Respiring Bacteria

    PubMed Central

    Roslev, Peter; King, Gary M.

    1993-01-01

    The tetrazolium salt sodium 3′-{1-[(phenylamino)-carbonyl]-3,4-tetrazolium}-bis (4-methoxy-6-nitro)benzene-sulfonic acid hydrate (XTT) was examined for use as a colorimetric indicator of viability in respiring bacteria. XTT was reduced to an orange, water-soluble formazan product by Methylosinus trichosporium OB3b, Pseudomonas putida, Escherichia coli, and Bacillus subtilis. Formazan production was proportional to live cell biomass, and XTT was reduced by all cultures in the absence of added electron-coupling agents. XTT reduction by M. trichosporium OB3b was linear over several hours and was stimulated by the presence of an exogenous substrate (methanol). Addition of cyanide to cultures incubated under oxic conditions gave an initial 10-fold increase in XTT reduction. Viability of bacteria incubated in the absence of exogenous carbon substrates was measured as XTT reduction and compared with viability estimates from plate counts. Results obtained with the two methods were generally comparable, but the XTT assay was superior when cell recovery on plates was low. Incubation of E. coli for 7 days in the absence of exogenous carbon substrates decreased viability by 90%, whereas the corresponding decreases for cultures of M. trichosporium OB3b, P. putida, and B. subtilis were less than 40%. PMID:16349038

  20. 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.

  1. DNA binding and antiproliferative activity toward human carcinoma cells of copper(II) and zinc(II) complexes of a 2,5-diphenyl[1,3,4]oxadiazole derivative.

    PubMed

    Terenzi, Alessio; Fanelli, Mirco; Ambrosi, Gianluca; Amatori, Stefano; Fusi, Vieri; Giorgi, Luca; Turco Liveri, Vincenzo; Barone, Giampaolo

    2012-04-21

    The interaction of calf thymus DNA with [CuL(ClO(4))]ClO(4)·H(2)O (1) and [ZnLBr]Br·H(2)O (2) (L = 9,12,15,18,27,28-hexaaza-29-oxatetracyclo[24.2.1.0(2,7).0(20,25)]enneicosa-2,4,6,20,22,24,26,28(1)-octaene) dicationic complexes in aqueous solution at neutral pH, was investigated by variable-temperature UV-vis absorption, circular dichroism and fluorescence spectroscopy. The values of the DNA-binding constants of these complexes, determined by competitive binding spectrofluorimetric titrations of ethidium bromide (EB)-DNA solutions, are (6.7 ± 0.5) × 10(6) M(-1) for CuL(2+) and (4.7 ± 0.5) × 10(5) M(-1) for ZnL(2+). These data together with a through analysis of the spectroscopic behaviour consistently suggest that both compounds are effective DNA binders. Interestingly, the DNA-binding strength of these complexes has been found to be correlated to their in vitro cytotoxic activity toward human breast carcinoma cells, although the complex with lower DNA-binding affinity is more active. In fact, biological studies showed that when the compounds are delivered through the cell membrane by a lipidic carrier, the cell survival is sensibly reduced, up to 58% with 1 and to 31% with 2.

  2. 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.

  3. [Spectrophotometer detection of benzalkonium bromide concentration in seawater].

    PubMed

    Pan, Jianyu; Yin, Pinghe; Zhao, Ling; Qi, Yuzao; Xie, Longchu

    2003-07-01

    Benzalkonium bromide is a high-efficiency algaecide. Its concentration in seawater was measured by the method of spectrophotometer. The results indicated that the deposition appeared if the concentration of benzalkonium bromide in seawater was more than 50 mg.L-1, and affected the detection of benzalkonium bromide. But, there was a good linear relationship between concentration and absorbance when the concentration was lower than 50 mg.L-1 (R2 = 0.9996). Therefore, spectrophotometer could be used to detect benzalkonium bromide in seawater.

  4. Pulse radiolysis of tetrazolium violet in aqueous and aqueous-alcoholic solutions under oxidative and reductive conditions

    NASA Astrophysics Data System (ADS)

    Kovács, A.; Wojnárovits, L.; Pálfi, T.; Emi-Reynolds, G.; Fletcher, J.

    2008-09-01

    The radiolytic reduction of colourless tetrazolium salts to coloured formazans in liquid and solid state is suggested for dosimetry purposes. In order to clarify the reaction mechanism, a pulse radiolysis study was conducted in aqueous and aqueous-alcoholic solutions under oxidative and reductive conditions. Under reducing conditions, fast formation of the electron adduct tetrazolinyl radical was observed: coloured formazan final product formed during the decay of electron adduct. Both the decay of the tetrazolinyl radical and the formation of the formazan were found to be second order. The spectra of the formazan were similar in neutral and alkaline solutions, but with higher absorbance in the latter solutions due to the higher molar absorption coefficient. Under oxidative conditions formazan did not form; hydroxylated products through OH-adducts were observed in the pH range studied.

  5. 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.

  6. 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…

  7. 40 CFR 721.10393 - Sodium bromide MDA complex (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Sodium bromide MDA complex (generic... Specific Chemical Substances § 721.10393 Sodium bromide MDA complex (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as sodium...

  8. Sir Charles Locock and potassium bromide.

    PubMed

    Eadie, M J

    2012-01-01

    On 12 May 1857, Edward Sieveking read a paper on epilepsy to the Royal Medical and Chirurgical Society in London. During the discussion that followed Sir Charles Locock, obstetrician to Queen Victoria, was reported to have commented that during the past 14 months he had used potassium bromide to successfully stop epileptic seizures in all but one of 14 or 15 women with 'hysterical' or catamenial epilepsy. This report of Locock's comment has generally given him credit for introducing the first reasonably effective antiepileptic drug into medical practice. However examination of the original reports raises questions as to how soundly based the accounts of Locock's comments were. Subsequently, others using the drug to treat epilepsy failed to obtain the degree of benefit that the reports of Locock's comments would have led them to expect. The drug might not have come into more widespread use as a result, had not Samuel Wilks provided good, independent evidence for the drug's antiepileptic efficacy in 1861.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. A fluorescent redox dye. Influence of several substrates and electron carriers on the tetrazolium salt-formazan reaction of Ehrlich ascites tumour cells.

    PubMed

    Stellmach, J; Severin, E

    1987-01-01

    This study was performed to elaborate the best conditions for measuring the redox activity of Ehrlich ascites tumour cells by using a new tetrazolium salt, cyantolyl tetrazolium chloride (CTC). This tetrazolium salt forms a fluorescent water-insoluble formazan on reduction on the surface of intact vital cells. The influences of fixation and of various substrates and electron carriers on the cellular reduction of CTC were investigated quantitatively using an elution technique. The amount of formazan obtained after incubating vital cells with Meldola Blue as electron carrier was greater than that obtained with Methylene Blue, menadione, 2,6-dichloroindophenol, 1-methoxyphenazine methosulphate or phenazine methosulphate. Using flow cytometry, the formazan production per cell and, after staining the nuclear DNA, the distribution of the redox activity in the cell population can be visualized with satisfactory resolution. We conclude from our findings that dehydrogenases are only partially involved in the reduction of tetrazolium salts by intact cells and that a redox activity, probably related to a cell membrane-bound NAD(P)H-oxidase system, is mainly measured.

  14. 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.

  15. Methyl Bromide Commodity Fumigation Buffer Zone Lookup Tables

    EPA Pesticide Factsheets

    Product labels for methyl bromide used in commodity and structural fumigation include requirements for buffer zones around treated areas. The information on this page will allow you to find the appropriate buffer zone for your planned application.

  16. 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...

  17. Computational and vibrational spectroscopic studies of ipratropium bromide.

    PubMed

    Ali, H R H; Edwards, H G M; Kendrick, J; Scowen, I J

    2009-02-01

    In this study, ipratropium bromide is investigated using vibrational spectroscopy and quantum chemical calculations. The structure of ipratropium bromide was optimised using density functional theory calculations and the geometry optimisation has been carried out on two conformations with and without intramolecular hydrogen bonding. Infrared and Raman spectra were calculated from the optimised structures. Many modes in the calculated spectra could be matched with the experimental spectra and a description of the modes is given. By analysis of the theoretical vibrational modes, it is shown that ipratropium bromide specimens are likely to be a mixture of the two conformations with and without intramolecular hydrogen bonding. In addition, several spectral features and band intensities in the CH and OH stretching regions are explained. Quantum mechanical calculations allowed improved understanding of ipratropium bromide and its vibrational spectra.

  18. Multi-centre assessment of nitroblue tetrazolium reactivity in human semen as a potential marker of oxidative stress.

    PubMed

    Gosálvez, Jaime; Coppola, Lamberto; Fernández, Jose Luis; López-Fernández, Carmen; Góngora, Alfredo; Faundez, Ricardo; Kim, John; Sayme, Nabil; de la Casa, Moises; Santiso, Rebeca; Harrison, Keith; Agarwal, Ashok; Johnston, Stephen; Esteves, Sandro C

    2017-02-16

    The nitroblue tetrazolium (NBT) reaction as a tracer of oxidative stress was examined in 707 ejaculates from seven clinics. Semen was initially surveyed by classifying the NBT reaction using a pre-established rank for the Oxisperm® test based on three colourimetric levels: L1, low (n = 141 [20%]); L2, medium (n = 538 [76%]) and L3, high (n = 28 [4%]). L3 was indicative of a high level of superoxide anions. Halosperm® chromatin dispersion assay was used to analyse samples of ejaculates 30 min after ejaculation; no difference was found in DNA fragmentation of L1 or L3; L3 category semen samples incubated for 24 h at 37(o)C showed a significantly faster rate (P < 0.001) of DNA damage than those in L1. The NBT reaction was further characterized in the ejaculates of 100 patients to determine the relative contribution of seminal plasma, spermatozoa, or both. Seminal plasma was the most significant fraction of •O2(-) localization, whereas sperm fractions generated detectable reactive oxygen species in only 32% of the ejaculates. Formazan precipitates were primarily associated with the sperm mid-piece and seminal leukocytes; however, not all spermatozoa stained positive to formazan and not all leukocytes presented with equivalent production of superoxide anions.

  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.

  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. Pd-Catalyzed Nucleophilic Fluorination of Aryl Bromides

    PubMed Central

    2015-01-01

    On the basis of mechanism-driven reaction design, a Pd-catalyzed nucleophilic fluorination of aryl bromides and iodides has been developed. The method exhibits a broad substrate scope, especially with respect to nitrogen-containing heteroaryl bromides, and proceeds with minimal formation of the corresponding reduction products. A facilitated ligand modification process was shown to be critical to the success of the reaction. PMID:24559304

  2. Synthesis, self-aggregation and biological properties of alkylphosphocholine and alkylphosphohomocholine derivatives of cetyltrimethylammonium bromide, cetylpyridinium bromide, benzalkonium bromide (C16) and benzethonium chloride.

    PubMed

    Lukáč, Miloš; Mrva, Martin; Garajová, Mária; Mojžišová, Gabriela; Varinská, Lenka; Mojžiš, Ján; Sabol, Marián; Kubincová, Janka; Haragová, Hana; Ondriska, František; Devínsky, Ferdinand

    2013-08-01

    A series of alkylphosphocholine and alkylphosphohomocholine derivatives of cetyltrimethylammonium bromide, cetylpyridinium bromide, benzalkonium bromide (C16) and benzethonium chloride have been synthesized. Their physicochemical properties were also investigated. The critical micelle concentration (cmc), the surface tension value at the cmc (γcmc), and the surface area at the surface saturation per head group (Acmc) were determined by means of surface tension measurements. The prepared compounds exhibit significant cytotoxic, antifungal and antiprotozoal activities. Alkylphosphocholines and alkylphosphohomocholines possess higher antifungal activity against Candida albicans in comparison with quaternary ammonium compounds in general. However, quaternary ammonium compounds exhibit significantly higher activity against human tumor cells and pathogenic free-living amoebae Acanthamoeba lugdunensis and Acanthamoeba quina compared to alkylphosphocholines. The relationship between structure, physicochemical properties and biological activity of the tested compounds is discussed.

  3. Spectral characteristics of the bentonite loaded with benzyldimethyloctadecylammonium chloride, hexadecyltrimethylammonium bromide and dimethyldioctadecylammonium bromide

    NASA Astrophysics Data System (ADS)

    Majdan, Marek; Maryuk, Oksana; Gładysz-Płaska, Agnieszka; Pikus, Stanisław; Kwiatkowski, Ryszard

    2008-02-01

    The spectral characterization, including the FTIR, DRIFT (diffusive reflectance), SWAXS (small and wide angle X-ray scattering) spectra comparison of the sodium bentonite modified by BDMODA-Cl (benzyldimethyloctadecylammonium chloride), HDTMA-Br (hexadecyltrimethylammonium bromide), DDA-Br (dimethyldioctadecylammonium bromide) is presented in the paper. The FTIR spectra show the shift of C-H stretching vibrations: νsym(CH2), νasym(CH2) of surfactants methylene chains toward lower frequencies (from 2855 to 2851 cm -1 for νsym(CH2) and from 2927 to 2918 cm -1 for νansym(CH2) with the surfactant concentration in bentonite phase. The bending vibrations δH-O-H in water molecules change their positions in the direction of higher frequencies (from 1634 to 1647 cm -1) with the surfactant concentration for bentonite-BDMODA and bentonite-DDA contrary to bentonite-HDTMA, where the constant position δH-O-H is explained as the consequence of the lower concentration of the hydrogen bonded water in bentonite-HDTMA phase when compared with the remaining forms of bentonite. The DRIFT spectra reveal dramatic shift of the νSi-O stretching vibration toward higher frequencies upon intercalation of the sodium bentonite with the surfactant cations. The SWAXS spectra and SEM images of the bentonite are the evidence of somewhat different sorption mechanism of DDA-Br when compared with the BDMODA-Cl and HDTMA-Br, including remarkable external surface sorption contribution in the overall sorption.

  4. 49 CFR 173.193 - Bromoacetone, methyl bromide, chloropicrin and methyl bromide or methyl chloride mixtures, etc.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... pounds) water capacity (nominal). This capacity does not apply to shipments of methyl bromide. (c) Methyl... metal cans containing not over one pound each, or inside metal cans with a minimum wall thickness of...

  5. Alkene- and alkyne- substituted methylimidazolium bromides: structural effects and Physical properties (Postprint)

    DTIC Science & Technology

    2007-08-01

    1, 3 - butene - 2 , propargyl- 3 , 2 -butyne- 4, and 2 -pent- yne- 5 side chains and their structural and physical proper- ties have been investigated...pargyl bromide, 2 -butyne bromide, 3 - butene bromide and 2 -pen- tyne bromide), methanol (99.93 % A.C.S. HPLC grade) and diethyl ether (anhydrous, 99...zolium halides (X Cl, Br, I), and 1-( 2 -butyne)- 3 - methyl - imidazolium bromide have been mentioned earlier [20, 21, 2328, 38, 39]. However, detailed

  6. Use of 5-cyano-2,3-ditolyl tetrazolium chloride for quantifying planktonic and sessile respiring bacteria in drinking water.

    PubMed

    Schaule, G; Flemming, H C; Ridgway, H F

    1993-11-01

    Direct microscopic quantification of respiring (i.e., viable) bacteria was performed for drinking water samples and biofilms grown on different opaque substrata. Water samples or biofilms developed in flowing drinking water were incubated with the vital redox dye 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) and R2A medium. One hour of incubation with 0.5 mM CTC was sufficient to obtain intracellular reduction of CTC to the insoluble fluorescent formazan (CTF) product, which was indicative of cellular respiratory (i.e., electron transport) activity. This result was obtained with both planktonic and biofilm-associated cells. Planktonic bacteria were captured on 0.2-microns-pore-size polycarbonate membrane filters and examined by epifluorescence microscopy. Respiring cells containing CTF deposits were readily detected and quantified as red-fluorescing objects on a dark background. The number of CTC-reducing bacteria was consistently greater than the number of aerobic CFU determined on R2A medium. Approximately 1 to 10% of the total planktonic population (determined by counterstaining with 4,6-diamidino-2-phenylindole) were respirometrically active. The proportion of respiring bacteria in biofilms composed of drinking water microflora was greater, ranging from about 5 to 35%, depending on the substratum. Respiring cells were distributed more or less evenly in biofilms, as demonstrated by counterstaining with 4,6-diamidino-2-phenylindole. The amount of CTF deposited in single cells of Pseudomonas putida that formed monospecies biofilms was quantified by digital image analysis and used to indicate cumulative respiratory activity. These data indicated significant cell-to-cell variation in respiratory activity and reduced electron transport following a brief period of nutrient starvation.(ABSTRACT TRUNCATED AT 250 WORDS)

  7. The effect of local UVB skin irradiation on the rate of formazan deposition in the epidermis of hairless mice studied by means of a tetrazolium-reduction method.

    PubMed

    Fosså, J; Iversen, O H; Thune, P O

    1980-01-01

    One-hundred-and-twenty hairless mice were irradiated with UVB (310 nm, exposure 60 mJ/cm2) on a limited area of the dorsal skin. At different time intervals after irradiation, the rate of endogenous dehydrogenase activity per mg dry epidermis was measured by the tetrazolium reduction method. The amount of formazan deposited remained normal for 18 h, and then increased, reaching a peak significantly higher than normal at 24 h, and thereafter returned to normal. At day 8 there was a new, probably significant peak. The reaction was followed for 14 days. It was concluded that UVB irradiation provokes a period of increased formazan deposition in the epidermis, similar to what has been observed after ionizing radiation and chemical carcinogens. The validity of the tetrazolium test for skin carcinogenic irritaments was thus also confirmed.

  8. Pairing Heterocyclic Cations with closo-Icosahedral Borane and Carborane Anions, II: Benchtop Alternative Synthetic Methodologies for Binary Triazolium and Tetrazolium Salts with Significant Water Solubility (POSTPRINT)

    DTIC Science & Technology

    2012-01-01

    was verified by direct ion chromatography analysis for the [Cl]– titer. Other new binary heterocyclium (triazolium and tetrazolium) closo-icosahedral...product KCl, using anhydrous acetonitrile was essential for successful flash filtration. High- performance liquid chromatography (HPLC)–grade...after initially opening a new vessel . For this investigation, commercial silica gel of moderate sieve size (70–230 mesh; Merck) was optimal

  9. Clarithromycin Susceptibility Testing of Mycobacterium avium Complex Using 2,3-Diphenyl-5-thienyl-(2)-tetrazolium Chloride Microplate Assay with Middlebrook 7H9 Broth

    PubMed Central

    Park, Young Kil; Koh, Won-Jung; Kim, Shin Ok; Shin, Sonya; Kim, Bum Joon; Cho, Sang-Nae; Lee, Sun Min

    2009-01-01

    A series of 119 Mycobacterium avium complex isolates were subjected to clarithromycin susceptibility testing using microplates containing 2,3-diphenyl-5-thienyl-(2)-tetrazolium chloride (STC). Among 119 isolates, 114 (95.8%) were susceptible to clarithromycin and 5 were resistant according to the new and the standard method. STC counts the low cost and reduces the number of procedures needed for susceptibility testing. PMID:19543518

  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. Methyl bromide: effective pest management tool and environmental threat.

    PubMed

    Thomas, W B

    1996-12-01

    Methyl bromide is used extensively on a global basis as a pesticide against nematodes, weeds, insects, fungi, bacteria, and rodents. As a soil fumigant, it is used in significant quantities in the production of strawberry and tomato, as well as other agriculture commodities. Grain, fresh fruit, forestry products, and other materials are fumigated with methyl bromide to control pest infestations during transport and storage. Structures also are treated with this chemical to control wood-destroying insects and rodents. However, methyl bromide has been identified as a significant ozone-depleting substance, resulting in regulatory actions being taken by the U.S. Environmental Protection Agency and the United Nations Environment Program (Montreal Protocol). The science linking methyl bromide to ozone depletion is strong and was reinforced by the 1994 UNEP Montreal Protocol Science Assessment on Ozone Depletion, which states, "Methyl bromide continues to be viewed as a significant ozone-depleting compound." Identifying efficacious and viable alternatives in the near term is critical.

  12. Cross-coupling of aromatic bromides with allylic silanolate salts.

    PubMed

    Denmark, Scott E; Werner, Nathan S

    2008-12-03

    The sodium salts of allyldimethylsilanol and 2-butenyldimethylsilanol undergo palladium-catalyzed cross-coupling with a wide variety of aryl bromides to afford allylated and crotylated arenes. The coupling of both silanolates required extensive optimization to deliver the expected products in high yields. The reaction of the allyldimethylsilanolate takes place at 85 degrees C in 1,2-dimethoxyethane with allylpalladium chloride dimer (2.5 mol %) to afford 73-95% yields of the allylation products. Both electron-rich and sterically hindered bromides reacted smoothly, whereas electron-poor bromides cross-coupled in poor yield because of a secondary isomerization to the 1-propenyl isomer (and subsequent polymerization). The 2-butenyldimethylsilanolate (E/Z, 80:20) required additional optimization to maximize the formation of the branched (gamma-substitution) product. A remarkable influence of added alkenes (dibenzylideneacetone and norbornadiene) led to good selectivities for electron-rich and electron-poor bromides in 40-83% yields. However, bromides containing coordinating groups (particularly in the ortho position) gave lower, and in one case even reversed, selectivity. Configurationally homogeneous (E)-silanolates gave slightly higher gamma-selectivity than the pure (Z)-silanolates. A unified mechanistic picture involving initial gamma-transmetalation followed by direct reductive elimination or sigma-pi isomerization can rationalize all of the observed trends.

  13. Methyl Bromide: Effective Pest Management Tool and Environmental Threat

    PubMed Central

    Thomas, W. B.

    1996-01-01

    Methyl bromide is used extensively on a global basis as a pesticide against nematodes, weeds, insects, fungi, bacteria, and rodents. As a soil fumigant, it is used in significant quantities in the production of strawberry and tomato, as well as other agriculture commodities. Grain, fresh fruit, forestry products, and other materials are fumigated with methyl bromide to control pest infestations during transport and storage. Structures also are treated with this chemical to control wood-destroying insects and rodents. However, methyl bromide has been identified as a significant ozone-depleting substance, resulting in regulatory actions being taken by the U.S. Environmental Protection Agency and the United Nations Environment Program (Montreal Protocol). The science linking methyl bromide to ozone depletion is strong and was reinforced by the 1994 UNEP Montreal Protocol Science Assessment on Ozone Depletion, which states, "Methyl bromide continues to be viewed as a significant ozone-depleting compound." Identifying efficacious and viable alternatives in the near term is critical. PMID:19277178

  14. 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

  15. Cetyltrimethyl ammonium bromide assisted hydrothermal growth of hematite hollow cubes

    SciTech Connect

    Wang, Wei-Wei; Yao, Jia-Liang

    2010-11-15

    Hematite hollow cubes have been prepared by forced hydrolysis of ferric chloride solutions under hydrothermal conditions. The effects of reaction time, reaction temperature and cetyltrimethyl ammonium bromide on the transformation process from akageneite to hematite were investigated in detail. The products were characterized by X-ray powder diffraction, scanning electron microscopy and transmission electron microscopy. It is found that cetyltrimethyl ammonium bromide was a critical factor influencing the phase transformation process of akageneite and the final morphology of the as-prepared products. With cetyltrimethyl ammonium bromide, hematite hollow cubes and porous spheres were obtained. Otherwise only dense cubes were observed even prolonging reaction time or increasing reaction temperature. The mechanism was proposed.

  16. [Tiotropium bromide for treating chronic obstructive pulmonary disease].

    PubMed

    Uteshev, D B; Buniatian, N D; Kovaleva, V L

    2010-11-01

    Five different types of muscarine-sensitive receptors were identified until now. In routine practice, the nonselective antagonist of cholinoreceptors are replaced by ipratropium bromide that is selectively blocking M1, M2, and M3 subtypes with the same affinity to each of them. However, the blockage of M2 subtype leads to bronchoconstriction and is accompanied by inhibition of M3 receptors in bronchial smooth muscles. The new drug tiotropium bromide selectively inhibits only the M1 and M3 types of receptors and does not affect the M2 subtype. This drug is administered only once a day, which is very important in clinical practice. Thus tiotropium bromide is the drug of choice for basic therapy of COPD.

  17. Sodium cromoglycate and ipratropium bromide in exercise-induced asthma.

    PubMed Central

    Thomson, N C; Patel, K R; Kerr, J W

    1978-01-01

    In thirteen patients with extrinsic asthma the effects of placebo, sodium cromoglycate, ipratropium bromide, and ipratropium bromide plus sodium cromoglycate were studied in a random double-blind fashion to assess their inhibitory action in exercise-induced asthma (EIA). Exercise testing consisted of steady state running on an inclined treadmill for up to eight minutes. In eight of the 13 patients studied the baseline ratio of expiratory flow at 50% vital capacity (VC) breathing helium-oxygen (V50He) to V50air was over 1.20 and they were called responders; the remaining five patients were called non-responders. There was a significantly lower baseline maximum mid-expiratory flow rate (MMEF) in non-responders (P less than 0.02) as compared to responders but no difference in forced expiratory volume in one second (FEV1) or forced vital capacity (FVC). Sodium cromoglycate (P less than 0.02), ipratropium bromide (P less than 0.01), and ipratropium bromide plus spdium cromoglycate (P less than 0.01) all significantly inhibited the percentage fall in FEV1 after exercise in the responders. Ipratropium bromide had no preventive action on non-responders, unlike sodium cromoglycate (P less than 0.05) and ipratropium bromide plus sodium cromoglycate (P less than 0.02). It is postulated that mediator release is an important factor in development of EIA in most extrinsic asthmatics, whereas cholinergic mechanisms are relevant only in those patients in whom the main site of airflow obstruction is in the large central airways. PMID:154747

  18. 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.

  19. The noncellular reduction of MTT tetrazolium salt by TiO₂ nanoparticles and its implications for cytotoxicity assays.

    PubMed

    Lupu, A R; Popescu, T

    2013-08-01

    We report results of noncellular tests, revealing the occurrence of photocatalytic interactions between titanium dioxide (TiO2, titania) nanoparticles and the MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium-bromide] cytotoxicity indicator. These interactions induce the reduction of MTT and formation of purple formazan under biologically relevant conditions. Classical MTT assays have been performed to evaluate the production of formazan in DMEM-F12 and RPMI-1640 cell culture media (containing 10% fetal bovine serum-FBS) treated with Degussa-P25 TiO2 nanoparticles, in the absence of cells. The colorimetric determinations revealed the noncellular MTT to formazan transformation induced by TiO2 nanoparticles, under conditions commonly used for in vitro cytotoxicity testing of nanomaterials. The formazan precipitation was found to be proportional to the TiO2 concentration, being enhanced under laboratory daylight exposure. The photocatalytic nature of the studied effect was assessed under UV irradiation at 365nm. The biological significance of the reported reaction was established with respect to cellular reference experiments performed on V79-4, HeLa and B16 cell lines. The results show false viability increases with up to 14% (for TiO2 concentrations generally higher than 50μg/ml), induced by the TiO2-MTT reaction. This type of artifacts may lead to underestimated toxicity or false proliferation results.

  20. 1-Bromo-3,5-diphenyl­benzene

    PubMed Central

    Wang, Zhi-Qiang; Li, Hong-Mei; Sun, Xiao-Juan; Cen, Fei-Fei; Ji, Bao-Ming

    2009-01-01

    The title compound, C18H13Br, crystallizes with two crystallographically independent mol­ecules in the asymmetric unit. The C—Br bond lengths and the C—C bond lengths between the benzene rings are slightly different in the two mol­ecules. The dihedral angles between adjacent benzene rings are 26.85 (2) and 39.99 (2)° in one mol­ecule, and 29.90 (2) and 38.01 (2)° in the other. There are three types of inter­molecular C—H⋯π inter­actions in the crystal structure. PMID:21578812

  1. Chemical alternatives to methyl bromide for Florida ornamental production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This project is a cooperative effort among USDA, ARS and University of Florida researchers, Florida in-ground ornamental producers, and fumigant industry representatives. Funding is provided through the USDA-ARS Area-wide Pest Management Program for Alternatives to Methyl Bromide. The ornamental i...

  2. Status of Alternatives for Methyl Bromide in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide is a fumigant used for disinfestation of soils, commodities and structures. Listed as an ozone-depleting chemical international environmental protocols and the U.S. Clean Air Act require that its use be severely restricted. Although use of this fumigant has fallen considerably, the U....

  3. 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...

  4. 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...

  5. 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 ...

  6. Evaluation of the Efficacy of Methyl Bromide in the ...

    EPA Pesticide Factsheets

    Journal Article The objective of this article is to determine the required conditions for the effective inactivation of Bacillus anthracis (B.a.) spores on materials using methyl bromide (MeBr) and to obtain comparative efficacy data with three avirulent microorganisms, to assess their potential as surrogates for B.a. Ames.

  7. The Fate of Alternative Soil Funigants to Methyl Bromide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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 b...

  8. 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.

  9. Actual hazard of methyl bromide fumigation in soil disinfection.

    PubMed Central

    Van Den Oever, R U; Roosels, D; Lahaye, D

    1982-01-01

    Methyl bromide, a highly toxic and ready penetrating fumigant, is widely used against rodents, insects, mites, and a range of pathogenic organisms in soil, compost, and timber. To disinfect soil in greenhouses, methyl bromide is brought under pressure from outside by a vaporiser and blown on to ground under a polyethylene cover. The gas being three times heavier than air easily penetrates the ground. Depending on the local ventilation, a considerable amount of gas evaporates into the surrounding atmosphere, this emission being especially serious during the fumigation procedure and at the removal of the plastic cover. Previously, mechanical injection of methyl bromide on to the ground within closed areas was prohibited, since this technique exposed at least four disinfection workers at a time, who were provided with only a canister respirator, to gas concentrations of over 1000 ppm CH3Br. The present study established that fumigation with methyl bromide also carries risks for the well-protected worker inside, as well as for the one controlling the vaporiser. The concentration during application varies from 30 to 3000 ppm. Concentration in the air declines with time to 4 ppm CH3Br five days after application. Discarding the plastic sheet involves exposure to peak values as high as 200 ppm for a few seconds. On the ninth day after application, milling the soil can expose workers to up to 15 ppm; on the eleventh day no CH3Br concentration in the air could be found. PMID:7066229

  10. Bromide ion effect on N-nitrosodimethylamine formation by monochloramine.

    PubMed

    Luh, Jeanne; Mariñas, Benito J

    2012-05-01

    N-Nitrosodimethylamine (NDMA) formation experiments conducted in phosphate buffer demonstrated that in waters containing monochloramine, the presence of bromide ion enhanced NDMA formation at the relatively high pH values of 8 and 9 after 24 h of reaction time, which was consistent with literature results. However, at relatively low to neutral pH (6 to 7), the presence of bromide resulted in lower NDMA formation as compared to results obtained in the absence of bromide. The hypothesis that bromamines were the species directly responsible for enhanced NDMA formation at high pH was tested and was shown not to be valid. Additional active bromine species were also tested, including hypobromous acid, hypobromite ion, and tribromide ion, with no species showing an ability to directly enhance NDMA formation. Analysis of the UV spectral data corresponding to the NDMA experiments suggest that the mechanism by which bromide enhances NDMA formation lies in the formation of a haloamine compound, possibly the mixed dihaloamine bromochloramine.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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, nove...

  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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  14. 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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  15. 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 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  16. On the existence of ‘L-alanine cadmium bromide'

    NASA Astrophysics Data System (ADS)

    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.

  17. 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.

  18. 75 FR 5582 - Methyl Bromide; Amendments to Terminate Uses

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-03

    ... or on alfalfa hay and cottonseed for these product registrations. These are the last products containing the pesticide methyl bromide registered for use on alfalfa hay and cotton seed in the United... post-harvest alfalfa hay and post-harvest cottonseed uses is prohibited after October 31, 2009,...

  19. 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...

  20. 40 CFR 180.123 - Inorganic bromide residues resulting from fumigation with methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... fumigated with the antimicrobial agent and insecticide methyl bromide after harvest (with the exception of... None Pumpkin, postharvest 20.0 None Quince, postharvest 5.0 None Radish, postharvest 30.0 None Rice..., postharvest 20.0 None Turnip, roots, postharvest 30.0 None Walnut, postharvest 200.0 None...

  1. 40 CFR 180.123 - Inorganic bromide residues resulting from fumigation with methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... fumigated with the antimicrobial agent and insecticide methyl bromide after harvest (with the exception of... None Pumpkin, postharvest 20.0 None Quince, postharvest 5.0 None Radish, postharvest 30.0 None Rice..., postharvest 20.0 None Turnip, roots, postharvest 30.0 None Walnut, postharvest 200.0 None...

  2. 40 CFR 180.123 - Inorganic bromide residues resulting from fumigation with methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... fumigated with the antimicrobial agent and insecticide methyl bromide after harvest (with the exception of... None Pumpkin, postharvest 20.0 None Quince, postharvest 5.0 None Radish, postharvest 30.0 None Rice..., postharvest 20.0 None Turnip, roots, postharvest 30.0 None Walnut, postharvest 200.0 None...

  3. 40 CFR 180.123 - Inorganic bromide residues resulting from fumigation with methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... fumigated with the antimicrobial agent and insecticide methyl bromide after harvest (with the exception of... None Pumpkin, postharvest 20.0 None Quince, postharvest 5.0 None Radish, postharvest 30.0 None Rice..., postharvest 20.0 None Turnip, roots, postharvest 30.0 None Walnut, postharvest 200.0 None...

  4. 40 CFR 180.123 - Inorganic bromide residues resulting from fumigation with methyl bromide; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... fumigated with the antimicrobial agent and insecticide methyl bromide after harvest (with the exception of..., postharvest 5.0 Radish, postharvest 30.0 Rice, grain, postharvest 50.0 Rutabaga, roots, postharvest 30.0..., roots, postharvest 30.0 Walnut, postharvest 200.0 Watermelon, postharvest 20.0 Wheat 50.0 (2)...

  5. Heat capacities of the water + lithium bromide + ethanolamine and water + lithium bromide + 1,3-propanediol systems

    SciTech Connect

    Kim, J.S.; Park, Y.; Lee, H.; Yu, S.I.

    1997-03-01

    Heat capacities of the water + lithium bromide + ethanolamine (LiBr/H{sub 2}N(CH{sub 2}){sub 2}OH mass ratio = 3.5) and water + lithium bromide + 1,3-propanediol (LiBr/HO(CH{sub 2}){sub 3}OH mass ratio = 3.5) systems were measured by using an isoperibol solution calorimeter at four temperatures (283.15, 298.15, 313.15, and 333.15 K) and absorbent (LiBr + H{sub 2}N(CH{sub 2}){sub 2}OH and LiBr + HO(CH{sub 2}){sub 3}OH) concentration ranges of (29.2 to 70.7)% and (30.7 to 68.3)%, respectively. The measured values were fitted with a simple equation by a least-squares method and the average absolute deviations between experimental and calculated values were 0.21% for the water + lithium bromide + ethanolamine system and 0.15% for the water + lithium bromide + 1,3-propanediol system, respectively.

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  8. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  9. 40 CFR 721.4090 - Ethanaminium, N-[bis(diethylamino)-methylene]-N-ethyl-, bromide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  10. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 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...

  11. 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...

  12. 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...

  13. 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...

  14. 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...

  15. 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...

  16. 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

  17. A comparative evaluation of whole blood total antioxidant capacity using a novel nitroblue tetrazolium reduction test in patients with periodontitis and healthy subjects: A randomized, controlled trial.

    PubMed

    Konuganti, Kranti; Seshan, Hema; Zope, Sameer; Silvia, Wilma Delphine

    2012-10-01

    The investigation of disease-related oxidant-antioxidant imbalance is difficult due to the limited availability of specific biomarkers of oxidative stress, and the fact that measurement of individual antioxidant may give misleading picture because antioxidants work in concert through chain breaking reactions. Therefore, analysis of total antioxidant capacity may be the most relevant investigation. As the total blood is continuously exposed to oxidative stress, the aim of the current study was to investigate total blood antioxidant capacity in healthy and periodontitis patients by using novel Nitroblue Tetrazolium reduction test. The study was conducted on 30 non-smoking volunteers with age ranging between 18-40 years. They were categorized into two groups; chronic periodontitis group and healthy group, respectively. Total antioxidant capacity in whole blood was assessed using Nitroblue Tetrazolium reduction test. Results of the present study has shown that the total antioxidant capacity in whole blood in patients with periodontitis was significantly (P<0.005) lower than in control subjects. The reduced total blood antioxidant status in periodontitis subjects warrants further investigation as it may provide a mechanistic link between periodontal disease and several other free radical-associated chronic inflammatory diseases.

  18. 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.

  19. 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.

  20. A novel and robust conditioning lesion induced by ethidium bromide

    PubMed Central

    Hollis, Edmund R; Ishiko, Nao; Tolentino, Kristine; Doherty, Ernest; Rodriguez, Maria J.; Calcutt, Nigel A.; Zou, Yimin

    2015-01-01

    Molecular and cellular mechanisms underlying the peripheral conditioning lesion remain unsolved. We show here that injection of a chemical demyelinating agent, ethidium bromide, into the sciatic nerve induces a similar set of regeneration-associated genes and promotes a 2.7-fold greater extent of sensory axon regeneration in the spinal cord than sciatic nerve crush. We found that more severe peripheral demyelination correlates with more severe functional and electrophysiological deficits, but more robust central regeneration. Ethidium bromide injection does not activate macrophages at the demyelinated sciatic nerve site, as observed after nerve crush, but briefly activates macrophages in the dorsal root ganglion. This study provides a new method for investigating the underlying mechanisms of the conditioning response and suggests that loss of the peripheral myelin may be a major signal to change the intrinsic growth state of adult sensory neurons and promote regeneration. PMID:25541322

  1. Thermal stability of octadecyltrimethylammonium bromide modified montmorillonite organoclay.

    PubMed

    Xi, Yunfei; Zhou, Qin; Frost, Ray L; He, Hongping

    2007-07-15

    Organoclays are significant for providing a mechanism for the adsorption of organic molecules from potable water. As such their thermal stability is important. A combination of thermogravimetric analysis and infrared emission spectroscopy was used to determine this stability. Infrared emission spectroscopy (IES) was used to investigate the changes in the structure and surface characteristics of water and surfactant molecules in montmorillonite, octadecyltrimethylammonium bromide and organoclays prepared with the surfactant octadecyltrimethylammonium bromide with different surfactant loadings. These spectra collected at different temperatures give support to the results obtained from the thermal analysis and also provide additional evidence for the dehydration which is difficult to obtain by normal thermoanalytical techniques. The spectra provide information on the conformation of the surfactant molecules in the clay layers and the thermal decomposition of the organoclays. Infrared emission spectroscopy proved to be a useful tool for the study of the thermal stability of the organoclays.

  2. 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.

  3. 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.

  4. [The compatibility between packing material and ipratropium bromide aerosol].

    PubMed

    Yue, Zhi-hua; Shen, Dian-dian; Hu, Chang-qin

    2010-08-01

    With the establishment of HPLC and LC-MS methods to determine the related substances and the content of active pharmaceutical ingredient (API) in ipratropium bromide aerosol products, several packing material-related impurities were identified, including antioxygen BHT and antioxygen 2246. Results showed that these leachable additives from the packing materials may present at a relative high level in the drug solution, and the low content of API in the drug products is usually due to the adsorption of the packing material as well as the leaking of contents. The current available assay methods for the control of ipratropium bromide aerosol products are often lack of specificity and unable to assure the drug quality effectively. To meet the increasing attention on the regulations of drug packing materials, our research would be a pilot study, indicating that the inappropriate packing materials could cause the migration and adsorption of the active ingredients, and the importance to have compatibility studies between packing materials and drugs.

  5. Effect of bromide and nitrite on the degradation of monochloramine

    SciTech Connect

    Valentine, R.L.; Selleck, R.E.

    1981-10-01

    The results indicate that relatively small concentrations of nitrite can greatly accelerate the degradation of monochloramine in the presence of bromide. It does not appear that nitrite is being significantly consumed in a 1:1 stoichiometric oxidation by monochloramine. If the effect of nitrite is catalytic then these results suggest that the presence of nitrite may also accelerate other oxidation-reduction reactions. For example, nitrite may play an important role in oxidant decay in partially nitrified sewage effluents where both monochloramine and nitrite may be present. If not a complex oxidation-reduction possibly involving bromide as a catalyst is indicated. The results also suggest that the presence of other potentially oxidizable species may affect oxidant decay in a manner not attributable to a simple parallel oxidation.

  6. A Lithium Bromide Absorption Chiller with Cold Storage

    DTIC Science & Technology

    2011-01-15

    TO R A G E A LITHIUM BROMIDE ABSORPTION CHILLER WITH COLD STORAGE William Gerstler, et al, General Electric Global Research UNCLASSIFIED UNLIMITED...Research ABSTRACT A LiBr-based absorption chiller can use waste heat or solar energy to produce useful space cooling for small buildings...However, operating this absorption chiller at high ambient tem- peratures may result in performance degradation, crystallization in the absorber, and

  7. Conservative tracer bromide inhibits pesticide mineralisation in soil.

    PubMed

    Bech, Tina B; Rosenbom, Annette E; Sørensen, Sebastian R; Jacobsen, Carsten S

    2017-03-01

    Bromide is a conservative tracer that is often applied with non-conservative solutes such as pesticides to estimate their retardation in the soil. It has been applied in concentrations of up to 250 g Br L(-1), levels at which the growth of single-celled organisms can be inhibited. Bromide applications may therefore affect the biodegradation of non-conservative solutes in soil. The present study investigated the effect of potassium bromide (KBr) on the mineralisation of three pesticides - glyphosate, MCPA and metribuzin - in four agricultural A-horizon soils. KBr was added to soil microcosms at concentrations of 0, 0.5, 2.5 and 5 g Br(-) L(-1) in the soil solution. The study concluded that KBr had a negative effect on pesticide mineralisation. The inhibitory effect varied depending on the KBr concentration, the type of pesticide and the type of soil. Furthermore, 16 S amplicon sequencing revealed that the KBr treatment generally reduced the abundance of bacteroidetes and proteobacteria on both an RNA and DNA level. Therefore, in order to reduce the effect of KBr on the soil bacterial community and consequently also on xenobiotic degradation, it is recommended that KBr be applied in a concentration that does not exceed 0.5 g Br(-) L(-1) in the soil water.

  8. 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.

  9. In vitro screening of six anthelmintic plant products against larval Haemonchus contortus with a modified methyl-thiazolyl-tetrazolium reduction assay.

    PubMed

    Hördegen, P; Cabaret, J; Hertzberg, H; Langhans, W; Maurer, V

    2006-11-03

    Because of the increasing anthelmintic resistance and the impact of conventional anthelmintics on the environment, it is important to look for alternative strategies against gastrointestinal nematodes. Phytotherapy could be one of the major options to control these pathologies. Extracts or ingredients of six different plant species were tested against exsheathed infective larvae of Haemonchus contortus using a modified methyl-thiazolyl-tetrazolium (MTT) reduction assay. Pyrantel tartrate was used as reference anthelmintic. Bromelain, the enzyme complex of the stem of Ananas comosus (Bromeliaceae), the ethanolic extracts of seeds of Azadirachta indica (Meliaceae), Caesalpinia crista (Caesalpiniaceae) and Vernonia anthelmintica (Asteraceae), and the ethanolic extracts of the whole plant of Fumaria parviflora (Papaveraceae) and of the fruit of Embelia ribes (Myrsinaceae) showed an anthelmintic efficacy of up to 93%, relative to pyrantel tartrate. Based on these results obtained with larval Haemonchus contortus, the modified MTT reduction assay could be a possible method for testing plant products with anthelmintic properties.

  10. Effect of electron beam irradiation on the structural properties of poly(vinyl alcohol) formulations with triphenyl tetrazolium chloride dye (TTC)

    NASA Astrophysics Data System (ADS)

    Ali, Z. I.; Said, Hossam M.; Ali, H. E.

    2006-01-01

    Films of poly(vinyl alcohol) (PVA) composites with triphenyl tetrazolium chloride (TTC) dye were prepared and exposed to various radiation doses delivered by accelerated electrons. The results showed that at a low dose of 50 kGy, the colour difference (Δ E*) of PVA/TTC films was increased by ˜10 times of the initial value. However, the change in colour differences did not go systematically with increasing the TTC content, in which the composite with 1.5 wt% displayed higher value than that with 3.5 wt%. The differential scanning calorimetry (DSC) showed that the presence of the TTC dye caused a depression in the melting point ( Tm) and heat of fusion (Δ Hf) of the PVA bulk polymer. However, the thermogravimetric analysis (TGA) showed that the presence of the TTC dye improved the thermal stability of PVA. Also, the tensile strength at break of PVA/TTC composites was improved after electron beam irradiation.

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

    PubMed

    Alvarado-Gonzalez, Alcibey; Arce, Isabel

    2015-11-01

    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.

  12. Induced Adsorption of Chloride and Bromide by Submonolayer Amounts of Copper Underpotentially Deposited on Pt(111)

    DTIC Science & Technology

    1994-03-14

    S GD Induced Adsorption Of Chloride And Bromide By Submonolayer Amounts Of Copper Underpotentially Deposited On Pt(111). R. G6mez, J.M. Feliu, and...The underpotential deposition of submonolayer amounts of copper induces an enhanced adsorption of chloride and bromide on Pt(111) and is reflected in...nhinoItO _. •- Induced Adsorption of Chloride and Bromide by Submonolayer Amounts of Copper Underpotentially Deposited on Pt(1 11). R. G6mez1 , J.M

  13. Mixed Iodide-Bromide Methylammonium Lead Perovskite-based Diodes for Light Emission and Photovoltaics.

    PubMed

    Gil-Escrig, Lidón; Miquel-Sempere, Araceli; Sessolo, Michele; Bolink, Henk J

    2015-09-17

    Vacuum deposition techniques are used to prepare mixed iodide-bromide methylammonium lead perovskite diodes via an intermediate double layer of the pure iodide and bromide perovskites. The diodes lead to bright electroluminescence, whose emission spectra maxima shift from the infrared toward the visible with increasing bromide content. When illuminated with AM1.5 simulated sunlight the devices function as efficient solar cells with power conversion efficiencies as high as 12.9%.

  14. Comparison of Heat and Bromide as Tracers of Stream Exchanges With Shallow Ground Water

    NASA Astrophysics Data System (ADS)

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

    2002-12-01

    Heat and bromide were compared as tracers for examining stream/groundwater exchanges along the middle reaches of the Santa Clara River, CA, during a 10-hour surface-water sodium bromide injection. Three cross-sections comprised of 6 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. The heat and ground-water transport simulation model, VS2DH, and a closely related solute and ground-water transport simulation model, VS2DT, were matched up for comparison of simulated and observed temperatures and bromide concentrations in the streambed. Simulated sediment temperature were fitted to observed temperature results to yield apparent streambed hydraulic conductivities in each cross-section. Saturated hydraulic conductivities ranged from 1.39 x 10-5 m/s in the upper reach to 5.56 x 10-4 m/s in the lower reach. The temperature-based hydraulic conductivities were inserted into VS2DT to predict sediment bromide concentrations during the sodium bromide injection. The predicted bromide concentration curves in the sediments yielded an excellent match to the observed bromide concentrations, without adjustment of any model parameters. 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 water fluxes in near-stream environments.

  15. 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

  16. Solubilities of bromide salts of aluminum, cobalt, lead, manganese, potassium, and sodium when sparged with hydrogen bromide

    SciTech Connect

    Noble, E.G.; Shanks, D.E.

    1988-01-01

    The effects of HBr concentration and temperature on the solubility and hydration state of AlBr/sub 3/, CoBr/sub 2/, PbBr/sub 2/, MnBr/sub 2/, KBr, and NaBr were investigated by the Bureau of Mines. Saturated aqueous solutions of the Al, Pb, K, and Na bromides were sparged with HBr gas at 20/sup 0/, 40/sup 0/, and 60/sup 0/C, and saturated solutions of Co and Mn bromides were sparged at 20/sup 0/C. Increased HBr concentration caused decreased salt solubility because of the common ion effect for all the investigated bromides except PbBr/sub 2/. Aqueous solubilities at 20/sup 0/C were, in percent, 51.7 for AlBr/sub 3/, 53.2 for CoBr/sub 2/, 1.1 for PbBr/sub 2/, 59.6 for MnBr/sub 2/, 39.5 for KBr, and 47.4 for Na Br. At 60/sup 0/C,the solubilities were, in percent, 53.3 for AlBr/sub 3/, 2.2 for PbBr/sub 2/, 46.0 for KBr, and 53.8 for NaBr. Solubilities in solutions sparged to HBr saturation at 20/sup 0/C were, in percent, 0.5 for AlBr/sub 3/, 42.0 for CoBr/sub 2/, 32.2 for Br/sub 2/, 21.0 for MnBr/sub 2/, 0.6 for KBr, and 0.3 for NaBr. At 60/sup 0/C, the solubilities at HBr saturation were, in percent, 1.8 for AlBr/sub 3/, 41.4 for PbBr/sub 2/, 1.3 for KBr, and 0.4 for NaBr. CoBr/sub 2/ precipitated out to a minimum solubility of 27.2 pct at 28.7-pct-HBr concentration. Further increases in HBr concentration increased CoBr/sub 2/ solubility because of the formation of bromide complexes. PbBr/sub 2/ increased in solubility as HBr concentration increased.

  17. 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

  18. 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.

  19. A drinking water utility's perspective on bromide, bromate, and ozonation.

    PubMed

    Bonacquisti, Thomas P

    2006-04-17

    Application of ozone in drinking water treatment plants in the US is growing because of ozone's multiple benefits. Ozone functions as a powerful oxidizing agent and disinfecting agent, it improves finished water quality by reducing turbidity, it reduces the formation of many halogenated disinfection by-products, and it is capable of treating chlorine resistant organisms like cryptosporidia. However, when bromide ion is present, e.g. from the geology, runoff, or sea water intrusion, ozone will convert some of the bromide to bromate depending upon the treatment reaction conditions. Bromate can also be introduced into drinking water as a contaminant in the chlorine used for disinfection. The current maximum contaminant level (MCL) in the USA is 0.010 mg/L, and the maximum contaminant level goal (MCLG) is zero, because of the possibility that bromate may function as a genotoxic carcinogen. The level of the MCL, especially if it is lowered, will significantly impact the ability of many water suppliers to utilize ozone in their water treatment processes and also raise the costs of those applications.

  20. Octahedral Rotation Preferences in Perovskite Iodides and Bromides.

    PubMed

    Young, Joshua; Rondinelli, James M

    2016-03-03

    Phase transitions in ABX3 perovskites are often accompanied by rigid rotations of the corner-connected BX6 octahedral network. Although the mechanisms for the preferred rotation patterns of perovskite oxides are fairly well recognized, the same cannot be said of halide variants (i.e., X = Cl, Br, or I), several of which undergo an unusual displacive transition to a tetragonal phase exhibiting in-phase rotations about one axis (a(0)a(0)c(+) in Glazer notation). To discern the chemical factors stabilizing this unique phase, we investigated a series of 12 perovskite bromides and iodides using density functional theory calculations and compared them with similar oxides. We find that in-phase tilting provides a better arrangement of the larger bromide and iodide anions, which minimizes the electrostatic interactions, improves the bond valence of the A-site cations, and enhances the covalency between the A-site metal and Br(-) or I(-) ions. The opposite effect is present in the oxides, with out-of-phase tilting maximizing these factors.

  1. Deswelling kinetics of polyacrylate gels in solutions of cetyltrimethylammonium bromide.

    PubMed

    Nilsson, Peter; Hansson, Per

    2007-08-23

    The deswelling kinetics of single sodium polyacrylate gel beads (radius 40-160 microm) in aqueous solutions of cetyltrimethylammonium bromide under conditions of forced convection are investigated using micromanipulator assisted light microscopy. The purpose of the study is to further evaluate a previously published model (J. Phys. Chem. B 2003, 107, 9203) using a higher homolog surfactant. For gels with expected fast deswelling (small gel size/low surfactant concentration) and/or in low electrolyte concentration, the model is found to correctly predict the deswelling characteristics of the gel beads. However, for some gels with expected slow deswelling, especially in high electrolyte concentration (10 mM NaBr), the model widely underestimates the required deswelling time. The reason for this is argued to be the longer time frame and high bromide concentration allowing the formation of a denser, more ordered structure in the surface phase, which resists the deformation and reorganization of material necessary for deswelling. Unexpectedly long lag times before the start of deswelling are also found for gels in low surfactant concentration, indicating that a relatively high surfactant concentration in the gel, greatly exceeding the critical aggregation concentration, is needed to start formation of a collapsed surface phase. This critical surfactant concentration is found to be dependent on initial gel radius, as small gels require a relatively higher concentration to initiate collapse.

  2. 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.

  3. Optical and Rheological Properties of a Semi-Diluted Equimolar Solution of Cetyltrimethylammonium Bromide and Potassium Bromide

    NASA Astrophysics Data System (ADS)

    Decruppe, J. P.; Cappelaere, E.; Cressely, R.

    1997-02-01

    We report in this paper the results of rheological and optical experiments performed on a semi-diluted viscoelastic solution of cetyltrimethylammonium bromide (CTAB) in water with sodium bromide at a concentration of 0.3 M l^{-1} in surfactant and salt. This concentration in surfactant is much smaller than the concentration which gives a nematic phase at rest. The solution behaves like a Maxwell fluid with a single relaxation time. When submitted to a shear flow, this solution shows a behaviour typical of a system undergoing a phase transition. When observed between crossed polarizer and analyzer, the gap of the Couette cell appears divided in two bands the optical properties of which are different; in rheology, the curves σ(dot{γ}) are also characteristic of these systems where the shear stress presents a plateau extending between two critical values, dot{γ}_{1c}, and dot{γ}_{2c} of the shear rate. We finally compare the results with previous experiments performed on a concentrated solution of CTAB containing no salt.

  4. Budget of Methyl Bromide in the Atmosphere: Isotopic Constraints

    NASA Astrophysics Data System (ADS)

    Bill, M.; Miller, L. G.; Rhew, R. C.; Goldstein, A. H.

    2001-12-01

    Bromine radicals contribute significantly to stratospheric ozone loss through coupled reactions with ClO, HO2, and NO2 radicals. Bromine is approximately 40-100 times more effective, atom for atom, at destroying ozone than chlorine. For instance, Br coupled reactions are responsible for 30 to 50% of the total ozone loss in the polar vortex. The largest source of bromine to the stratosphere is methyl bromide (CH3Br). CH3Br has a concentration in the troposphere of about 10 pptv, a total estimated lifetime of 0.6 to 0.9 years, and has the highest concentration of any long lived organobromine. Unlike chlorofluorocarbons, which are produced entirely by humans, methyl bromide is produced by both anthropogenic and natural processes. We are developing the use of stable isotopes to constrain the budget of CH3Br through quantification of the source signatures and the isotopic fractionations associated with sinks. The largest natural sources appear to be biological production in oceans ( ~35%), biomass burning ( ~13%), and salt marshes ( ~10%). Thus far, the only natural emissions to be isotopically characterized is from salt marsh plants. Carbon isotopic ratios of CH3Br emitted from the salt marsh have a strong diurnal variation from -65\\permil during daytime when emission rates are highest to -12\\permil at night when emissions are ~13% of the daytime rates. The \\delta13C weighted mean of salt marsh emission is -43\\permil CH3Br. Anthropogenically produced CH3Br is used for fumigation of soils, harvested crops and structures, and represents approximately 30% of the total source flux. The fumigation of harvested crops and structures constitutes approximately one third of the anthropogenic source to the atmosphere and, because the release rate of applied CH3Br approaches 100%, it should have a mean isotopic composition equal to industrially manufactured CH3Br, -54.4\\permil. However during soil fumigation, some of the CH3Br is consumed insitu causing isotopic fractionation

  5. The first barium tin(II) bromide fluoride

    NASA Astrophysics Data System (ADS)

    Dénès, Georges; Merazig, Hocine; Muntasar, Abdualhafeed; Porterfield, Robyn

    2014-04-01

    In an effort to prepare barium tin(II) bromide fluorides for the first time, possibly similar to the chloride fluorides obtained earlier in our laboratory, precipitation reactions were carried out by mixing aqueous solutions of SnF2 and of BaBr2.2H2O. In contrast with the chloride fluoride system, a single powdered phase was obtained throughout the SnF2 - BaBr2 system, with the yield being maximum at X ≈ 0.25, where X is the molar fraction of barium bromide in the reaction mixture. Phase identification with the JCPDS database failed to produce a match, confirming that a new phase had been produced. The exact chemical composition of the new compound has not been obtained yet. Based on the X value for the maximum yield, the Sn/Ba ratio is likely to be 3/1 or 2/1. The Mössbauer spectrum at ambient conditions shows that bonding to tin(II) is covalent, therefore with the tin lone pair being stereoactive. The Mössbauer parameters ( δ = 3.68 mm/s, Δ = 0.99 mm/s) are similar to those of SnBrF and of Sn2BrF5, thereby showing that tin is bonded to both fluorine and bromine. The larger isomer shift and lower quadrupole splitting than in tin(II) fluorides show that the stereoactivity of the tin lone pair is lower than in the fluorides. The Mössbauer parameters fit well the linear correlation of the quadrupole splitting versus the isomer shift" that has been shown to be present in other series of tin(II) compounds. The linear decrease on this correlation shows that the contribution of non-spherical orbitals ( p and d) to the lone pair is a much larger contributor to the quadrupole splitting than lattice distortions. The structure is likely made of Ba2+ cations and tin(II) fluoride bromide polyatomic anions, with covalent bonding withinthe anions.

  6. Solid phase microextraction for active or passive sampling of methyl bromide during fumigations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The high diffusivity and volatility of methyl bromide make it an ideal compound for Solid Phase Micro Extraction (SPME)-based sampling of air prior to gas-chromatographic quantifications. SPME fibers can be used as active methyl bromide samplers, with high capacities and an equilibrium time of 1-2 m...

  7. Synergistic Actions of Pyridostigmine Bromide and Insecticides on Muscle and Vascular Nociceptors

    DTIC Science & Technology

    2014-01-01

    TITLE: Synergistic Actions of Pyridostigmine Bromide and Insecticides on Muscle and Vascular Nociceptors PRINCIPAL INVESTIGATOR: Brian...pyridostigmine bromide (PB) and a variety of insecticides /repellants co-varied with the development of this condition (Research Advisory Committee on Gulf War...might occur between insecticides , repellants and nerve agent prophylactics used during the GW could modify or damage the machinery of protein

  8. 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...

  9. 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

    ... 2013 control period? U.S. consumption of methyl bromide in the U.S. has declined significantly over the... Act, 42 U.S.C. 7671c. Under EPA implementing regulations, methyl bromide production and consumption... Montreal Protocol provides that the Parties may exempt ``the level of production or consumption that...

  10. Classifying the Basic Parameters of Ultraviolet Copper Bromide Laser

    NASA Astrophysics Data System (ADS)

    Gocheva-Ilieva, S. G.; Iliev, I. P.; Temelkov, K. A.; Vuchkov, N. K.; Sabotinov, N. V.

    2009-10-01

    The performance of deep ultraviolet copper bromide lasers is of great importance because of their applications in medicine, microbiology, high-precision processing of new materials, high-resolution laser lithography in microelectronics, high-density optical recording of information, laser-induced fluorescence in plasma and wide-gap semiconductors and more. In this paper we present a statistical study on the classification of 12 basic lasing parameters, by using different agglomerative methods of cluster analysis. The results are based on a big amount of experimental data for UV Cu+ Ne-CuBr laser with wavelengths 248.6 nm, 252.9 nm, 260.0 nm and 270.3 nm, obtained in Georgi Nadjakov Institute of Solid State Physics, Bulgarian Academy of Sciences. The relevant influence of parameters on laser generation is also evaluated. The results are applicable in computer modeling and planning the experiments and further laser development with improved output characteristics.

  11. Accommodation coefficient of HOBr on deliquescent sodium bromide aerosol particles

    NASA Astrophysics Data System (ADS)

    Wachsmuth, M.; Gäggeler, H. W.; von Glasow, R.; Ammann, M.

    2002-06-01

    Uptake of HOBr on sea salt aerosol, sea salt brine or ice is believed to be a key process providing a source of photolabile bromine (Br2) and sustaining ozone depletion cycles in the Arctic troposphere. In the present study, uptake of HOBr on sodium bromide (NaBr) aerosol particles was investigated at an extremely low HOBr concentration of 300 cm-3 using the short-lived radioactive isotopes 83-86Br. Under these conditions, at maximum one HOBr molecule was taken up per particle. The rate of uptake was clearly limited by the mass accommodation coefficient, which was calculated to be 0.6 ± 0.2. This value is a factor of 10 larger than estimates used in earlier models. The atmospheric implications are discussed using the box model "MOCCA'', showing that the increase of the accommodation coefficient of HOBr by a factor of 10 only slightly affects net ozone loss, but significantly increases chlorine release.

  12. Theoretical and experimental studies of silver bromide clusters

    NASA Astrophysics Data System (ADS)

    Zhang, Hongguang

    2000-11-01

    This work consists of three parts: Experimental synthesis of silver bromide clusters via the electroporation of unilamellar dioleoylphosphatidylcholine (DOPC) vesicles, theoretical study of the structure and electronic properties of (AgBr)n clusters, and characterization of silver bromide clusters grown and their interaction with the surface of DOPC vesicles. In the first part, we successfully synthesized AgBr quantum dots via the electroporation of vesicles. For the first time, we observed the entire blue-shift followed by red-shift of the absorption band (274nm --> 5h 269nm --> 6h 273nm) that is associated with the growth of the silver bromide clusters. The turn-around point is at 269 nm. In the second part, we have theoretically investigated the structures and UV absorption spectra of (AgBr)n clusters (n = 1-9) in both the gas phase and in a dielectric medium. The structures of clusters were determined at the B3P86/SB level with full geometry optimization. For clusters with n = 1-6, extensive searches of the potential energy surface yielded only one minimum, while larger clusters displayed two or more minima. UV absorption spectra were calculated by the configuration interaction singlet (CIS) method with a much larger basis set. Our computational results parallel the experimental trends, and show that the turn- around point occurs at the trimer according to HOMO-LUMO gap calculation and at the tetramer according to CIS calculation. The molecular origin of the blue/red shift associated with AgBr cluster growth can be readily explained by examining the orbital interactions which dominate the process and by the structure of the clusters. The detailed molecular orbital energy level correlation diagram for the dimerization, trimerization and tetramerization will be presented. In the third part, TEM characterization of the quantum dots show

  13. 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.

  14. Reactions of buffers in cyanogen bromide-induced ligations.

    PubMed

    Vogel, Heike; Gerlach, Claudia; Richert, Clemens

    2013-01-01

    Rapid, template-directed ligation reactions between a phosphate-terminated oligonucleotide and an unphosphorylated reaction partner may be induced by cyanogen bromide (BrCN). Frequently, however, the reaction is low yielding, and even a large excess of the condensing agent can fail to induce quantitative conversions. In this study, we used BrCN to induce chemical primer extension reactions. Here, we report that buffers containing hydroxyl groups react with short oligodeoxynucleotides in the presence of BrCN. One stable adduct between HEPBS buffer and cytosine was characterized by mass spectrometry and NMR after HPLC purification, indicating that a side reaction occurred at this nucleobase. Further, a first example of a primer extension reaction between an unmodified oligodeoxynucleotide as primer and dGMP is reported. Together, our results shed light on the potency, as well as the drawbacks of BrCN as a highly reactive condensing reagent for the ligation of unmodified nucleic acids.

  15. 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.

  16. 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.

  17. Effects of pyridostigmine bromide on in-flight aircrew performance.

    PubMed

    Gawron, V J; Schiflett, S G; Miller, J C; Slater, T; Ball, J F

    1990-02-01

    The effects of a chemical defense pretreatment drug, pyridostigmine bromide (PB), on in-flight aircrew performance were assessed using the Total In-Flight Simulator (TIFS) aircraft. TIFS was used to supply appropriate control dynamics, handling characteristics, and cockpit instrumentation for a tactical transport airdrop simulation. Twenty-one C-130 pilots flew two familiarization and four data flights. During two data flights PB was given to both members of the aircrew using the dosage regimen of 30 mg/8 h prescribed by the U.S. Air Force surgeon general. The drug was administered using a double-blind technique. The results indicated that (1) aircrews successfully completed their assigned mission, (2) airdrop inaccuracies and navigation errors in time and distance were not specifically related to PB, (3) performance and crew coordination were not affected by PB, (4) PB and pilot/copilot not discriminate beyond chance between PB and placebo conditions.

  18. 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

  19. N-(2-Bromo-benz-yl)cinchoninium bromide.

    PubMed

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

    2012-09-01

    The title compound {systematic name: 1-(2-bromo-benz-yl)-5-ethenyl-2-[hy-droxy(quinolin-4-yl)meth-yl]-1-aza-bicyclo-[2.2.2]octan-1-ium bromide}, C(26)H(28)BrN(2)O(+)·Br(-), is a chiral quater-nary ammonium salt of one of the Cinchona alkaloids. The planes of the quinoline and of the bromo-benzyl substituent are inclined to one another by 9.11 (9)°. A weak intra-molecular C-H⋯O hydrogen bond occurs. The crystal structure features strong O-H⋯Br hydrogen bonds and weak C-H⋯Br inter-actions.

  20. 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

  1. Electrochemical and spectroscopic study of octadecyltrimethylammonium bromide/DNA surfoplexes.

    PubMed

    Rodríguez-Pulido, Alberto; Aicart, Emilio; Junquera, Elena

    2009-04-21

    The use of cationic micelles consisting of octadecyltrimethylammonium bromide (C18TAB) to compact calf thymus DNA has been investigated in aqueous buffered solution at 310.15 K by means of conductometry, electrophoretic mobility, and several fluorescence spectroscopy methods. The results indicate that C18TAB micelles, consisting of 44 monomers on average, may compact DNA molecule by an electrostatic interaction that takes place at the cationic spherical micelle surface. The surfoplexes thus formed show a surface density charge that goes from negative to positive values at a Lmic/D mass ratio of around 1.0 (where Lmic and D are the masses of micellized cationic surfactant and DNA), called the isoneutrality ratio (Lmic/D)phi. Values of this characteristic parameter, determined in this work not only from the electrochemical experimental data but also from spectroscopic measurements, are in very good agreement with those ones calculated from molecular parameters and some other properties also obtained in this work. The electrostatic character of the DNA-micelle interaction has been confirmed by analyzing the decrease in fluorescence emission of the fluorophore ethidium bromide, EtBr, initially intercalated between DNA base pairs, as long as the surfoplexes are formed. Fluorescence anisotropy experiments have revealed that micelle packing becomes more rigid in the presence of DNA, but once the surfoplex is formed, the fluidity increases with the Lmic/D mass ratio, attaining its maximum when the isoneutrality ratio is exceeded. This fact, together with the net positive charge of the surfoplexes with the Lmic/D mass ratio over the isoneutrality ratio, makes this regimen of lipid and DNA content the optimum for efficiency in the transfection process.

  2. 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.

  3. Nebulised ipratropium bromide and sodium cromoglycate in the first two years of life.

    PubMed Central

    Henry, R L; Hiller, E J; Milner, A D; Hodges, I G; Stokes, G M

    1984-01-01

    In a double blind crossover trial, we compared sodium cromoglycate, ipratropium bromide, and water in 23 asthmatic children less than 2 years old (mean age 11.8 months). Each child received nebulised solutions containing 20 mg of sodium cromoglycate, 250 micrograms of ipratropium bromide, or 2 ml water three times a day for three two month periods. Daily symptom scores did not show significant differences between the treatments but parental preferences indicated that both sodium cromoglycate and ipratropium bromide were superior to placebo. Sodium cromoglycate was prophylactic and was more likely to help the older patients. Ipratropium bromide produced an immediate clinical benefit and the response was not age dependent. We were unable to pick responders from non-responders on the basis of lung function tests performed on a routine outpatient basis. Both ipratropium bromide and sodium cromoglycate help some but not all asthmatic children aged less than 2 years. PMID:6230059

  4. 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.

  5. Bromide's effect on DBP formation, speciation, and control; Part 1: Ozonation

    SciTech Connect

    Shukairy, H.M.; Summers, R.S. ); Miltner, R.J. . Drinking Water Research Div.)

    1994-06-01

    The effect of variable ozone dosage and bromide concentration on the formation of organic disinfection by-products (DBPs) and bromate were evaluated. Low ozone dosages resulted in oxidation of organic precursors, yielding decreases in the formation potential for total trihalomethanes (THMs), six haloacetic acids (HAAs), and total organic halide (TOX). Increasing the ozone dosage oxidized bromide to bromate, decreasing the bromide for incorporation into DBPs. Bromate concentrations were linearly correlated with ozone residuals. Changes in the bromine incorporation factors n and n[prime] reflected differences in the resulting speciation of THMs and HAAs, respectively. Because TOX measurements based on chloride equivalence may underestimate the halogenated DBP yield for high-bromide waters, a procedure is described whereby bromide and bromate concentrations were used to correct the TOX measurement.

  6. Derivation of an occupational exposure limit (OEL) for n-propyl bromide using an improved methodology.

    PubMed

    Rozman, Karl K; Doull, John

    2002-10-01

    n-Propyl bromide is an industrial solvent with increasing production volume due to its use as a replacement for fluorohydrocarbons. Therefore, the number of occupationally exposed workers is growing accordingly. This manuscript presents a thorough evaluation of available animal and human data to derive an occupational exposure limit (OEL) for n-propyl bromide. In addition, structure activity relationship within the homologous series of methyl, ethyl, and n-propyl bromide and an identical spectrum of effects caused by similar doses of 2-propyl bromide are used to increase the confidence of the analysis. The structure activity relationship was entirely consistent for acute and subchronic (neurologic, reproductive, and hematopoietic) toxicities and for mutagenic potency in that CH3Br was more toxic than CH3CH2Br, which in turn was more toxic than CH3CH2CH2Br in every case in all species studied, including humans. Animals appeared to be similarly susceptible as, or slightly more susceptible than, humans to n-propyl bromide's toxicity. An OEL (60-90 ppm) was derived from a limited human study and supported by an across-the-toxic-spectrum comparison of animal and human data for both n-propyl and 2-propyl bromide. A carcinogenic classification was not deemed necessary at the recommended OEL based on very low mutagenic potency and the consistent structure activity relationship across the homologous series of these alkyl bromides.

  7. Efficacy and safety of ipratropium bromide/albuterol delivered via Respimat inhaler versus MDI.

    PubMed

    Zuwallack, R; De Salvo, M C; Kaelin, T; Bateman, E D; Park, C S; Abrahams, R; Fakih, F; Sachs, P; Pudi, K; Zhao, Y; Wood, C C

    2010-08-01

    We compared the efficacy and safety of ipratropium bromide/albuterol delivered via Respimat inhaler, a novel propellant-free inhaler, versus chlorofluorocarbon (CFC)-metered dose inhaler (MDI) and ipratropium Respimat inhaler in patients with COPD. This was a multinational, randomized, double-blind, double-dummy, 12-week, parallel-group, active-controlled study. Patients with moderate to severe COPD were randomized to ipratropium bromide/albuterol (20/100mcg) Respimat inhaler, ipratropium bromide/albuterol MDI [36mcg/206mcg (Combivent Inhalation Aerosol MDI)], or ipratropium bromide (20mcg) Respimat inhaler. Each medication was administered four times daily. Serial spirometry was performed over 6h (0.15min, then hourly) on 4 test days. The primary efficacy variable was forced expiratory volume in 1s (FEV(1)) change from test day baseline at 12 weeks. A total of 1209 of 1480 randomized, treated patients completed the study; the majority were male (65%) with a mean age of 64 yrs and a mean screening pre-bronchodilator FEV(1) (percent predicted) of 41%. Ipratropium bromide/albuterol Respimat inhaler had comparable efficacy to ipratropium bromide/albuterol MDI for FEV(1) area under the curve at 0-6h (AUC(0-6)), superior efficacy to ipratropium Respimat inhaler for FEV(1) AUC(0-4) and comparable efficacy to ipratropium Respimat inhaler for FEV(1) AUC(4-6). All active treatments were well tolerated. This study demonstrates that ipratropium bromide/albuterol 20/100mcg inhaler administered four times daily for 12 weeks had equivalent bronchodilator efficacy and comparable safety to ipratropium bromide/albuterol 36mcg/206mcg MDI, and significantly improved lung function compared with the mono-component ipratropium bromide 20 mcg Respimat inhaler. [Clinical Trial Identifier Number: NCT00400153].

  8. The role of tiotropium bromide, a long-acting anticholinergic bronchodilator, in the management of COPD.

    PubMed

    Saberi, Farzad; O'Donnell, Denis E

    2005-01-01

    Bronchodilator therapy forms the mainstay of treatment for symptomatic patients with COPD. Long-acting bronchodilators, which maintain sustained airway patency over a 24-hour period, represent an advance in therapy. Tiotropium bromide is a new long-acting inhaled anticholinergic agent with superior pharmacodynamic properties compared with the short-acting anticholinergic, ipratropium bromide. Tiotropium bromide has been consistently shown to have a greater impact than ipratropium bromide on clinically important outcome measures such as health status. The mechanisms of clinical benefit with tiotropium bromide are multifactorial, but improved airway function, which enhances lung emptying and allows sustained deflation of over-inflated lungs, appears to explain improvements in dyspnea and exercise endurance in COPD. Inhaled tiotropium bromide therapy has also been associated with reduction in acute exacerbations of COPD as well as reduced hospitalizations. The safety profile of tiotropium bromide is impressive: dry mouth is the most common adverse event and rarely necessitates termination of the drug. No tachyphylaxis to tiotropium bromide has been demonstrated in clinical trials lasting up to 1 year. There is preliminary information that the combination of long-acting anticholinergics and long-acting beta2-adrenoceptor agonists provides additive physiological and clinical benefits. According to recent international guidelines, long-acting bronchodilators should be considered early in the management of symptomatic patients with COPD in order to achieve effective symptom alleviation and reduction in activity limitation. Tiotropium bromide, because of its once-daily administration and its established efficacy and tolerability profile, has emerged as an attractive therapeutic option for this condition.

  9. 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.

  10. Use of 5-Cyano-2,3-Ditolyl-Tetrazolium Chloride Staining as an Indicator of Biocidal Activity in a Rapid Assay for Anti-Acanthamoeba Agents

    PubMed Central

    Kobayashi, Takeshi; Mito, Tsuyoshi; Watanabe, Narumi; Suzuki, Takashi; Ohashi, Yuichi

    2012-01-01

    The usefulness of 5-cyano-2,3-ditolyl-tetrazolium chloride (CTC) staining to determine the respiratory activity of Acanthamoeba was evaluated in this study. Acanthamoeba trophozoites and cysts have a red fluorescence after staining with CTC. To determine the effectiveness of CTC staining as a CTC biocidal assay for Acanthamoeba, the trophozoites and cysts of Acanthamoeba castellanii (ATCC 5037) were treated with serial concentrations of disinfectant solutions, namely, polyhexamethylene biguanide (PHMB) and commercial soft contact lens (SCL) disinfectant solutions. The treated Acanthamoeba organisms were stained with CTC, and their respiratory activity was determined by the intensity of fluorescence in a fluorescence microplate reader. The survival rates of the same samples were determined by a culture-dependent biocidal assay using the Spearman-Karber method. Our results showed that the respiratory activities determined by the CTC biocidal assay and the survival rates determined by the culture-dependent biocidal assay for Acanthamoeba trophozoites and cysts decreased in a dose-dependent way after PHMB treatments, and the results were significantly correlated (r = 0.83 and P < 0.01 for trophozoites; r = 0.60 and P < 0.01 for cysts; Spearman rank correlation test). The respiratory activities in the trophozoites and cysts treated with SCL disinfectant solutions were significantly correlated with the survival rate (r = 0.70 and P < 0.01 for trophozoites; r = 0.64 and P < 0.01 for cysts; Spearman rank correlation test). The significant correlation of the results indicated that the CTC biocidal assay can be used as an alternative method to a culture-dependent biocidal assay. The CTC biocidal assay is a rapid and simple method to test the effectiveness of disinfectant solutions against Acanthamoeba trophozoites and cysts. PMID:22337974

  11. [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.

  12. Rapid, easy cyanation of aryl bromides and chlorides using nickel salts in conjunction with microwave promotion.

    PubMed

    Arvela, Riina K; Leadbeater, Nicholas E

    2003-11-14

    We report here a fast, easy, and efficient method for the preparation of aryl nitriles from aryl bromides and chlorides. The methodology for aryl bromides involves the use of either Ni(CN)(2) or NaCN and NiBr(2). With aryl chlorides, a mix of NaCN and NiBr(2) is used and the reaction proceeds via the in situ formation of the corresponding aryl bromide. The reaction can be performed in air and is complete within 10 min.

  13. Bronchodilating effect of combined therapy with ipratropium bromide and ondansetron in patients with COPD.

    PubMed

    Pauwels, Romain; Joos, Guy F; Fogarty, Charles; Faiferman, Isidore; Hirschberg, Sandra; Vessey, Rupert; Wouters, Emiel F M

    2008-01-01

    The objectives of this study were to determine the effect of single and repeat dosing with oral ondansetron, a 5-HT3-specific receptor blocker, on the degree and duration of bronchodilation induced by inhaled ipratropium bromide in patients with COPD. Five clinics and university medical centers in four countries participated in the study; 47 patients with COPD were randomized to treatment; 44 completed all treatments. Patients had a baseline (pre-bronchodilator) FEV1>1L and post-bronchodilator (200 mcg salbutamol) FEV1<90% of predicted, with FEV1 reversibility (to 80 mcg inhaled ipratropium bromide and 400 mcg salbutamol) of at least 12% or 200 mL over baseline. The study was divided into two parts. In Part A, each patient received in a random order, four-way crossover manner, single doses of ondansetron placebo (oral) plus ipratropium bromide placebo (inhaled), ondansetron placebo plus ipratropium bromide 40 mcg inhaled via MDI, ondansetron 24 mg oral plus ipratropium bromide placebo and ondansetron 24 mg plus ipratropium bromide 40 mcg. In Part B, each patient received in a random order, two-way crossover manner, ipratropium bromide 40 mcg tid via MDI plus ondansetron 8 mg oral, qid, for 2 days; on day 3 patients received a single dose of ipratropium bromide 40 mcg plus 8 mg oral ondansetron. Alternatively, patients received ipratropium bromide via MDI and oral ondansetron placebo, as described above. Statistically significant differences in weighted mean FEV1 (0-6h), peak FEV1 and FEV1 determined 6h post-dose were noted comparing ipratropium bromide to placebo. Similar positive results were observed for sGaw and FVC. Addition of ondansetron to ipratropium bromide did not significantly modify values obtained with ipratropium alone. Ipratropium bromide induced a marked bronchodilation, compared to placebo. Addition of ondansetron (single or repeated doses) did not significantly increase the degree or duration of bronchodilation induced by ipratropium alone. s

  14. 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.

  15. Structural and electronic properties of Diisopropylammonium bromide molecular ferroelectric crystal

    NASA Astrophysics Data System (ADS)

    Alsaad, A.; Qattan, I. A.; Ahmad, A. A.; Al-Aqtash, N.; Sabirianov, R. F.

    2015-10-01

    We report the results of ab-initio calculations based on Generalized Gradient Approximation (GGA) and hybrid functional (HSE06) of electronic band structure, density of states and partial density of states to get a deep insight into structural and electronic properties of P21 ferroelectric phase of Diisopropylammonium Bromide molecular crystal (DIPAB). We found that the optical band gap of the polar phase of DIPAB is ∼ 5 eV confirming it as a good dielectric. Examination of the density of states and partial density of states reveal that the valence band maximum is mainly composed of bromine 4p orbitals and the conduction band minimum is dominated by carbon 2p, carbon 2s, and nitrogen 2s orbitals. A unique aspect of P21 ferroelectric phase is the permanent dipole within the material. We found that P21 DIPAB has a spontaneous polarization of 22.64 consistent with recent findings which make it good candidate for the creation of ferroelectric tunneling junctions (FTJs) which have the potential to be used as memory devices.

  16. Factors affecting a cyanogen bromide-based assay of thiamin.

    PubMed

    Wyatt, D T; Lee, M; Hillman, R E

    1989-11-01

    We analyzed extensively a modified thiochrome method for thiamin analysis. Acid phosphatase (EC 3.1.3.2) from potato was superior to either alpha-amylase or acid phosphatase from wheat germ as a dephosphorylating agent. Timing of cyanogen bromide exposure was important, but the assay had good precision and accuracy. The standard curve was linear from 10 to 3000 nmol/L. The within-run and between-run coefficients of variation for total thiamin in whole blood were 3.6% and 7.4%, respectively. Analytical recoveries for low, intermediate, and high additions of thiamin to whole blood were 93-109%. Sample yield was increased by 41% (+/- 29% SD) with pre-assay freezing. Samples were stable for two days at room temperature, for seven days when refrigerated, and for two years when frozen. Previously unreported interference was seen with penicillin derivatives, and with several commonly used diuretic and antiepileptic medications. This assay may be suitable for population screening; 200 samples could be analyzed weekly at a cost of +0.20 per sample.

  17. 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.

  18. 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.

  19. High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices.

    PubMed

    Perumal, Ajay; Shendre, Sushant; Li, Mingjie; Tay, Yong Kang Eugene; Sharma, Vijay Kumar; Chen, Shi; Wei, Zhanhua; Liu, Qing; Gao, Yuan; Buenconsejo, Pio John S; Tan, Swee Tiam; Gan, Chee Lip; Xiong, Qihua; Sum, Tze Chien; Demir, Hilmi Volkan

    2016-11-09

    Formamidinium lead halide (FAPbX3) has attracted greater attention and is more prominent recently in photovoltaic devices due to its broad absorption and higher thermal stability in comparison to more popular methylammonium lead halide MAPbX3. Herein, a simple and highly reproducible room temperature synthesis of device grade high quality formamidinium lead bromide CH(NH2)2PbBr3 (FAPbBr3) colloidal nanocrystals (NC) having high photoluminescence quantum efficiency (PLQE) of 55-65% is reported. In addition, we demonstrate high brightness perovskite light emitting device (Pe-LED) with these FAPbBr3 perovskite NC thin film using 2,2',2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) commonly known as TPBi and 4,6-Bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) as electron transport layers (ETL). The Pe-LED device with B3PYMPM as ETL has bright electroluminescence of up to 2714 cd/m(2), while the Pe-LED device with TPBi as ETL has higher peak luminous efficiency of 6.4 cd/A and peak luminous power efficiency of 5.7 lm/W. To our knowledge this is the first report on high brightness light emitting device based on CH(NH2)2PbBr3 widely known as FAPbBr3 nanocrystals in literature.

  20. 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.

  1. Water-lithium bromide double-effect absorption cooling analysis

    NASA Astrophysics Data System (ADS)

    Vliet, G. C.; Lawson, M. B.; Lithgow, R. A.

    1980-12-01

    A numerical model was developed for the transient simulation of the double-effect, water-lithium bromide absorption cooling machine and was used 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 variables considered 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 indicates 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.

  2. [Treatment of cetyltrimethyl ammonium bromide wastewater by potassium ferrate].

    PubMed

    Yang, Wei-hua; Wang, Hong-hui; Zeng, Xiao-xu; Huang, Ting-ting

    2009-08-15

    A novel oxidant potassium ferrate (K2FeO4) was used to remove cetyltrimethyl ammonium bromide (CTAB) at room temperature. The effects of various conditions on the removal ratio, such as reaction time, dosing quantity of K2FeO4 and initial pH, were investigated. The experiments results show that the removal ratio reaches 79.4% when the reaction time is 30 min, the dosing quantity of K2FeO4 to CTAB is 1:1, the initial pH of the solution is 7. In the reaction progress, the oxidation of K2FeO4 and the flocculation of the reduction product have synergistic effect on the removal of CTAB. In addition, infrared spectra of CTAB before and after being treated with K2FeO4 were further studied. The results indicate that the degradation process involves the interruption of chain and the subsequent mineralization to inorganic molecules. Furthermore, the reaction of K2FeO4 and CTAB follows second order kinetics law.

  3. 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.

  4. 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.

  5. Associated anisotropy decays of ethidium bromide interacting with DNA

    NASA Astrophysics Data System (ADS)

    Chib, Rahul; Raut, Sangram; Sabnis, Sarika; Singhal, Preeti; Gryczynski, Zygmunt; Gryczynski, Ignacy

    2014-03-01

    Ethidium Bromide (EB) is a commonly used dye in a deoxyribonucleic acid (DNA) study. Upon an intercalation, this dye significantly increases its brightness and fluorescence lifetime. In this report we have studied the time resolved fluorescence properties of EB existing simultaneously in free and DNA-bound forms in the solution. Fluorescence intensity decays were fitted globally to a double exponential model with lifetimes corresponding to free (1.6 ns) and bound (22 ns) forms, and molar fractions were determined for all used solutions. Anisotropy decays displayed characteristic time dependence with an initial rapid decline followed by recovery and slow decay. The short-lived fraction associated with free EB molecules decreases faster than long-lived fraction associated with EB bound to DNA. Consequently, contribution from fast rotation leads to initial rapid decay in anisotropy. On the other hand bound fraction, due to slow rotation helps recover anisotropy in time. This effect of associated anisotropy decays in systems such as EB free/EB-DNA is clearly visible in a wide range of concentrations, and should be taken into account in polarization assays and biomolecule dynamics studies.

  6. High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices

    PubMed Central

    Perumal, Ajay; Shendre, Sushant; Li, Mingjie; Tay, Yong Kang Eugene; Sharma, Vijay Kumar; Chen, Shi; Wei, Zhanhua; Liu, Qing; Gao, Yuan; Buenconsejo, Pio John S.; Tan, Swee Tiam; Gan, Chee Lip; Xiong, Qihua; Sum, Tze Chien; Demir, Hilmi Volkan

    2016-01-01

    Formamidinium lead halide (FAPbX3) has attracted greater attention and is more prominent recently in photovoltaic devices due to its broad absorption and higher thermal stability in comparison to more popular methylammonium lead halide MAPbX3. Herein, a simple and highly reproducible room temperature synthesis of device grade high quality formamidinium lead bromide CH(NH2)2PbBr3 (FAPbBr3) colloidal nanocrystals (NC) having high photoluminescence quantum efficiency (PLQE) of 55–65% is reported. In addition, we demonstrate high brightness perovskite light emitting device (Pe-LED) with these FAPbBr3 perovskite NC thin film using 2,2′,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) commonly known as TPBi and 4,6-Bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) as electron transport layers (ETL). The Pe-LED device with B3PYMPM as ETL has bright electroluminescence of up to 2714 cd/m2, while the Pe-LED device with TPBi as ETL has higher peak luminous efficiency of 6.4 cd/A and peak luminous power efficiency of 5.7 lm/W. To our knowledge this is the first report on high brightness light emitting device based on CH(NH2)2PbBr3 widely known as FAPbBr3 nanocrystals in literature. PMID:27827424

  7. High brightness formamidinium lead bromide perovskite nanocrystal light emitting devices

    NASA Astrophysics Data System (ADS)

    Perumal, Ajay; Shendre, Sushant; Li, Mingjie; Tay, Yong Kang Eugene; Sharma, Vijay Kumar; Chen, Shi; Wei, Zhanhua; Liu, Qing; Gao, Yuan; Buenconsejo, Pio John S.; Tan, Swee Tiam; Gan, Chee Lip; Xiong, Qihua; Sum, Tze Chien; Demir, Hilmi Volkan

    2016-11-01

    Formamidinium lead halide (FAPbX3) has attracted greater attention and is more prominent recently in photovoltaic devices due to its broad absorption and higher thermal stability in comparison to more popular methylammonium lead halide MAPbX3. Herein, a simple and highly reproducible room temperature synthesis of device grade high quality formamidinium lead bromide CH(NH2)2PbBr3 (FAPbBr3) colloidal nanocrystals (NC) having high photoluminescence quantum efficiency (PLQE) of 55–65% is reported. In addition, we demonstrate high brightness perovskite light emitting device (Pe-LED) with these FAPbBr3 perovskite NC thin film using 2,2‧,2″-(1,3,5-Benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) commonly known as TPBi and 4,6-Bis(3,5-di(pyridin-3-yl)phenyl)-2-methylpyrimidine (B3PYMPM) as electron transport layers (ETL). The Pe-LED device with B3PYMPM as ETL has bright electroluminescence of up to 2714 cd/m2, while the Pe-LED device with TPBi as ETL has higher peak luminous efficiency of 6.4 cd/A and peak luminous power efficiency of 5.7 lm/W. To our knowledge this is the first report on high brightness light emitting device based on CH(NH2)2PbBr3 widely known as FAPbBr3 nanocrystals in literature.

  8. Superoxide generated by pyrogallol reduces highly water-soluble tetrazolium salt to produce a soluble formazan: a simple assay for measuring superoxide anion radical scavenging activities of biological and abiological samples.

    PubMed

    Xu, Chen; Liu, Shu; Liu, Zhiqiang; Song, Fengrui; Liu, Shuying

    2013-09-02

    Superoxide anion radical (O2(˙-)) plays an important role in several human diseases. The xanthine/xanthine oxidase system is frequently utilized to produce O2(˙-). However, false positive results are easily got by using this system. The common spectrophotometric probes for O2(˙-) are nitroblue tetrazolium (NBT) and cytochrome c. Nevertheless, the application of NBT method is limited because of the water-insolubility of NBT formazan and the assay using cytochrome c lacks sensitivity and is not suitable for microplate measurement. We overcome these problems by using 1,2,3-trihydroxybenzene (pyrogallol) as O2(˙-)-generating system and a highly water-soluble tetrazolium salt, 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium sodium salt (WST-1) which can be reduced by superoxide anion radical to a stable water-soluble formazan with a high absorbance at 450 nm. The method is simple, rapid and sensitive. Moreover, it can be adapted to microplate format. In this study, the O2(˙-) scavenging activities of superoxide dismutase (SOD), L-ascorbic acid, N-acetyl-L-cysteine (NAC), albumin from human serum, flavonoids and herbal extracts were assessed by using this method. Meanwhile, the activities of tissue homogenates and serum were determined by using this validated method. This method, applicable to tissue homogenates, serum and herbal extracts, proved to be efficient for measuring O2(˙-) scavenging activities of biological and abiological samples.

  9. Serum albumin leads to false-positive results in the XTT and the MTT assay.

    PubMed

    Funk, Dorothee; Schrenk, Hans-Hermann; Frei, Eva

    2007-08-01

    Tetrazolium salts like 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) or sodium 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) that form formazans after reduction are widely used to investigate cell viability. Besides cellular enzymes, some constituents of cell media and other substances reduce tetrazolium salts, thereby interfering with these assays. We describe here that different preparations of serum albumin from bovine or human origin can lead to a concentration-dependent increase in the signals of the XTT assay; therefore leading to an overestimation of cell numbers and to an underestimation of potential cytotoxic effects of compounds to be tested. The same effect was seen in the MTT assay with human serum albumin (HSA). We demonstrate that this reductive activity cannot be inactivated by proteolytic digestion, but that it is due to the free cysteine residue in albumin, and is also observed when cysteine or glutathione (GSH) are used. Binding of N-ethylmaleimide (NEM) to the free cysteine residue leads to a decrease of the albumin interference in the XTT assay.

  10. 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...

  11. Palladium-catalyzed carbonylation reaction of aryl bromides with 2-hydroxyacetophenones to form flavones.

    PubMed

    Wu, Xiao-Feng; Neumann, Helfried; Beller, Matthias

    2012-10-01

    Flavone of the month: a general and efficient method for the palladium-catalyzed carbonylative synthesis of flavones has been developed. Starting from aryl bromides and 2-hydroxyacetophenones, the corresponding flavones have been isolated in good yields.

  12. 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...

  13. 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.

  14. 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.

  15. Small airways ventilation heterogeneity and hyperinflation in COPD: response to tiotropium bromide.

    PubMed

    Verbanck, Sylvia; Schuermans, Daniël; Vincken, Walter

    2007-01-01

    In chronic obstructive pulmonary disease (COPD) patients tiotropium bromide has been shown to improve forced expiratory volume in one second (FEV1) and inspiratory capacity (IC). We investigated whether the mechanism leading to these improvements is related to small airways ventilation heterogeneity, assessed by multiple breath washout tests. Forty stable tiotropium-free COPD patients (FEV1: 27%-78% predicted) were studied before and 90 min after administration of tiotropium bromide on visit0, and following 3 and 6 weeks of tiotropium bromide treatment (visit3wks, visit6wks). After study completion, COPD patients were classified into two subgroups according to degree of hyperinflation at visit0 (Hyp-, Hyp+). The Hyp+ group showed significant increases in trough (ie, pre-dose) FEV1 and IC after 3 and 6 weeks of tiotropium bromide, and the 90 min tiotropium bromide responses of FEV1 and IC were significant at visit0 (p < or = 0.001 for both) but not during subsequent visits. The Hyp- group showed significant FEV1 increases 90 min after tiotropium bromide on all three visits (all p < 0.005) but no sustained increase in trough values. In both COPD subgroups, the grossly abnormal ventilation heterogeneity barely showed any significant improvements with tiotropium bromide in the conductive airways (without changes in trough value) and no changes at all in the acinar airways. We conclude that the sustained improvements in trough IC and FEV1 with tiotropium bromide predominantly observed in COPD patients with considerable hyperinflation, are unrelated to small airways ventilation heterogeneity.

  16. Flow Boiling Heat Transfer to Lithium Bromide Aqueous Solution in Subcooled Region

    NASA Astrophysics Data System (ADS)

    Furukawa, Masahiro; Kaji, Masao; Nishizumi, Takeharu; Ozaki, Shinji; Sekoguchi, Kotohiko

    To improve the thermal performance of high temperature generator of absorption chiller/heater, heat transfer characteristics of flow boiling of lithium bromide aqueous solution in the subcooled region were experimentally investigated. Experiments were made for water and lithium bromide aqueous solution flowing in a rectangular channel (5 mm × 20 mm cross section) with one side wall heated. Boiling onset quality of lithium bromide aqueous solution is greater than that of water. The heat transfer coefficient of lithium bromide aqueous solution is about a half of that of water under the same experimental conditions of inlet velocity and heat flux. The experimental data of heat transfer coefficient for water are compared with the empirical correlation of Thom et al.11) and a fairly good agreement is obtained. The predictive calculations by the method of Sekoguchi et al.12) are compared with the data for water and lithium bromide aqueous solution. Agreement between them is good for water, while the results for lithium bromide aqueous solution are not satisfactory.

  17. Preferential bromide and pesticide movement to tile drains under different cropping practices.

    PubMed

    Fortin, J; Gagnon-Bertrand, E; Vézina, L; Rompré, M

    2002-01-01

    Subsurface drainage systems are useful tools to study chemical leaching in soils. Our objective was to compare the breakthrough behavior of bromide, atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamid] to tile drains under two fall tillage practices (conventional tillage [CT] with a moldboard plow, and reduced tillage [RT] with a chisel plow) in field plots cultivated with corn (Zea mays L.). Leachate volume were greater in RT than in CT, with no statistical differences. Soil analysis showed that bromide migrated deeper in the soil profile than both herbicides, with little tillage effect. All chemicals were detected in drainage water at the same time and followed an event-driven behavior. Tillage had no effect on atrazine and metolachlor found in drainage water, while bromide concentration peaks were higher in RT than in CT in 1999. Concentration peaks were recorded earlier for atrazine and metolachlor than for bromide. Plots of cumulative relative chemical mass (cumulative mass divided by total mass measured in drainage) as a function of cumulative drainage were mostly linear for bromide, while they were S-shaped for both herbicides. Drainage that corresponded to 50% of relative cumulative mass ranged from 40 to 55% for bromide and from 5 to 28% for both herbicides. Rapid chemical movement to tile drains suggested that preferential flow was important in both CT and RT, and that these tillage practices had little influence on this phenomena.

  18. Dicationic alkylammonium bromide gemini surfactants. Membrane perturbation and skin irritation.

    PubMed

    Almeida, João A S; Faneca, Henrique; Carvalho, Rui A; Marques, Eduardo F; Pais, Alberto A C C

    2011-01-01

    Dicationic alkylammonium bromide gemini surfactants represent a class of amphiphiles potentially effective as skin permeation enhancers. However, only a limited number of studies has been dedicated to the evaluation of the respective cytotoxicity, and none directed to skin irritation endpoints. Supported on a cell viability study, the cytotoxicity of gemini surfactants of variable tail and spacer length was assessed. For this purpose, keratinocyte cells from human skin (NCTC 2544 cell line), frequently used as a model for skin irritation, were employed. The impact of the different gemini surfactants on the permeability and morphology of model vesicles was additionally investigated by measuring the leakage of calcein fluorescent dye and analyzing the NMR spectra of ³¹P, respectively. Detail on the interaction of gemini molecules with model membranes was also provided by a systematic differential scanning calorimetry (DSC) and molecular dynamics (MD) simulation. An irreversible impact on the viability of the NCTC 2544 cell line was observed for gemini concentrations higher than 25 mM, while no cytotoxicity was found for any of the surfactants in a concentration range up to 10 mM. A higher cytotoxicity was also found for gemini surfactants presenting longer spacer and shorter tails. The same trend was obtained in the calorimetric and permeability studies, with the gemini of longest spacer promoting the highest degree of membrane destabilization. Additional structural and dynamical characterization of the various systems, obtained by ³¹P NMR and MD, provide some insight on the relationship between the architecture of gemini surfactants and the respective perturbation mechanism.

  19. 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.

  20. Dicationic Alkylammonium Bromide Gemini Surfactants. Membrane Perturbation and Skin Irritation

    PubMed Central

    Almeida, João A. S.; Faneca, Henrique; Carvalho, Rui A.; Marques, Eduardo F.; Pais, Alberto A. C. C.

    2011-01-01

    Dicationic alkylammonium bromide gemini surfactants represent a class of amphiphiles potentially effective as skin permeation enhancers. However, only a limited number of studies has been dedicated to the evaluation of the respective cytotoxicity, and none directed to skin irritation endpoints. Supported on a cell viability study, the cytotoxicity of gemini surfactants of variable tail and spacer length was assessed. For this purpose, keratinocyte cells from human skin (NCTC 2544 cell line), frequently used as a model for skin irritation, were employed. The impact of the different gemini surfactants on the permeability and morphology of model vesicles was additionally investigated by measuring the leakage of calcein fluorescent dye and analyzing the NMR spectra of 31P, respectively. Detail on the interaction of gemini molecules with model membranes was also provided by a systematic differential scanning calorimetry (DSC) and molecular dynamics (MD) simulation. An irreversible impact on the viability of the NCTC 2544 cell line was observed for gemini concentrations higher than 25 mM, while no cytotoxicity was found for any of the surfactants in a concentration range up to 10 mM. A higher cytotoxicity was also found for gemini surfactants presenting longer spacer and shorter tails. The same trend was obtained in the calorimetric and permeability studies, with the gemini of longest spacer promoting the highest degree of membrane destabilization. Additional structural and dynamical characterization of the various systems, obtained by 31P NMR and MD, provide some insight on the relationship between the architecture of gemini surfactants and the respective perturbation mechanism. PMID:22102870

  1. 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.

  2. 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.

  3. 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.

  4. Eudragit RS PO nanoparticles for sustained release of pyridostigmine bromide

    NASA Astrophysics Data System (ADS)

    Hoobakht, Fatemeh; Ganji, Fariba; Vasheghani-Farahani, Ebrahim; Mousavi, Seyyed Mohammad

    2013-09-01

    Pyridostigmine bromide (PB) is an inhibitor of cholinesterase, which is used in the treatment of myasthenia gravis and administered for protection against exposure to toxic nerve agents. Tests were done to investigate prolonging the half-life of PB and improving its release behavior. PB was loaded in nanoparticles (NPs) of Eudragit RS PO (Eu-RS) prepared using the technique of quasi emulsion solvent diffusion. Variables of output power of the sonicator, bath temperature and mixing time, were chosen as the optimization factors to obtain the minimum sized NPs. In addition, emulsions were tested at different ratios of drug-to-polymer by dynamic light scattering to determine size and zeta potential of NPs. UV-spectroscopy was used to determine PB content of the NPs. Drug-loaded NPs were characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectra. Results determined that mixing time had a significant impact on the size of Eu-RS NPs, but power output of sonicator and bath temperature had no significant effect. The particle size obtained at the optimum condition (power output of 70 W, bath temperature of 33 °C, and mixing time of 7 min) was less than 200 nm (optimum sizes were 138.9 and 179.5 nm for Eu-RS and PB-loaded Eu-RS NPs, respectively). The optimum PB-loaded Eu-RS NPs at the PB to Eu-RS weight ratio of 1-4 and 20 % of loaded PB released from the nanocarriers within 100 h.

  5. 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

  6. 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???.

  7. Inhalable Ipratropium Bromide Particle Engineering with Multicriteria Optimization.

    PubMed

    Vinjamuri, Bhavani Prasad; Haware, Rahul V; Stagner, William C

    2016-11-21

    Spray-dried ipratropium bromide (IPB) microspheres for oral inhalation were engineered using Quality by Design. The interrogation of material properties, process parameters, and critical product quality attributes interplay enabled rational product design. A 2(7-3) screening design exhibited the Maillard reaction between L-leucine (LL) and lactose at studied outlet temperatures (OT) >130°C. A response surface custom design was used in conjunction with multicriteria optimization to determine the operating design space to achieve inhalable microparticles. Statistically significant predictive models were developed for volume median diameter (p = 0.0001, adjusted R (2)  = 0.9938), span (p = 0.0278, adjusted R (2)  = 0.7912), yield (p = 0.0020, adjusted R (2)  = 0.9320), and OT (p = 0.0082, adjusted R (2)  = 0.8768). An independent verification batch confirmed the model's predictive capability. The prediction and actual values were in good agreement. Particle size and span were 3.32 ± 0.09 μm and 1.71 ± 0.18, which were 4.7 and 5.3% higher than the predicted values. The process yield was 50.3%, compared to the predicted value of 65.3%. The OT was 100°C versus the predicted value of 105°C. The label strength of IPB microparticles was 99.0 to 105.9% w/w suggesting that enrichment occurred during the spray-drying process. The present study can be utilized to initiate the design of the first commercial IPB dry powder inhaler.

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

    PubMed

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

    2010-12-01

    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 postfumigation emissions of MeBr from soil, Ca(OH)(2), K(2)CO(3), and NH(3) were assessed as means of promoting MeBr degradation. Ammonia aqueous solution (NH(4)OH) was the most effective, because MeBr can be degraded by both hydrolysis and ammonolysis. At 20 °C, the half-lives (t(1/2)) of MeBr were 18.0, 2.5, and 1.3 h in 0.1, 1.0, and 2.0 M NH(4)OH, respectively. In 1.0 M NH(4)OH, increasing the solution temperature to 40 °C reduced the half-life of MeBr to 0.23 h. Ammonia amendment to moist soil also promoted MeBr transformation, and the MeBr degradation rate increased with increasing soil temperature. NH(4)OH (30%, 16 M) very effectively reacted with MeBr that was contained under plastic film. Under Hytibar (a virtually impermeable film, VIF), over 99.5% of the MeBr could be destroyed by 30% NH(4)OH in 8 h at 20 °C. On the basis of these results, good management practices (i.e., VIF plus NH(4)OH) could be developed for continued use of MeBr as a soil fumigant under Critical Use Exemptions, without significant emissions.

  9. Tiotropium bromide inhalation powder: a review of its use in the management of chronic obstructive pulmonary disease.

    PubMed

    Keating, Gillian M

    2012-01-22

    The anticholinergic agent tiotropium bromide (Spiriva®) is a long-acting bronchodilator that is indicated for the treatment of chronic obstructive pulmonary disease (COPD). This article reviews the clinical efficacy and tolerability of tiotropium bromide inhalation powder, administered using the HandiHaler® device, in patients with COPD, as well as reviewing its pharmacological properties and the results of pharmacoeconomic analyses. Shorter-term placebo-controlled trials in patients with COPD demonstrated significantly higher trough forced expiratory volume in 1 second (FEV(1)) responses with tiotropium bromide than with placebo, confirming it has a duration of action of ≥24 hours and is suitable for once-daily administration. Lung function improved to a greater extent with tiotropium bromide than with ipratropium bromide or, in most instances, salmeterol. Indacaterol was shown to be noninferior to tiotropium bromide in terms of the trough FEV(1) response. The large, 4-year UPLIFT® trial did not show a significant reduction in the annual rate of decline in FEV(1) with tiotropium bromide versus placebo in patients with COPD, although subgroup analyses demonstrated a significantly lower rate of decline with tiotropium bromide than with placebo in some patient groups (e.g. patients with moderate COPD, patients aged ≥50 years, patients not receiving maintenance therapy at baseline). Tiotropium bromide prevented exacerbations in patients with COPD, with a significantly lower exacerbation rate and a significantly longer time to first exacerbation seen with tiotropium bromide than with placebo or salmeterol. Exacerbation rates did not significantly differ between patients receiving tiotropium bromide and those receiving salmeterol/fluticasone propionate. Tiotropium bromide also had beneficial effects on health-related quality of life (HR-QOL) and other endpoints, such as dyspnoea and rescue medication use. Combination therapy with tiotropium bromide plus

  10. 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.

  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.

  12. Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS

    NASA Astrophysics Data System (ADS)

    Liao, J.; Huey, L. G.; Scheuer, E.; Dibb, J. E.; Stickel, R. E.; Tanner, D. J.; Neuman, J. A.; Nowak, J. B.; Choi, S.; Wang, Y.; Salawitch, R. J.; Canty, T.; Chance, K.; Kurosu, T.; Suleiman, R.; Weinheimer, A. J.; Shetter, R. E.; Fried, A.; Brune, W.; Anderson, B.; Zhang, X.; Chen, G.; Crawford, J.; Hecobian, A.; Ingall, E. D.

    2012-02-01

    A focus of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was examination of bromine photochemistry in the spring time high latitude troposphere based on aircraft and satellite measurements of bromine oxide (BrO) and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometer (CIMS) to measure BrO and a mist chamber (MC) to measure soluble bromide. We have determined that the MC detection efficiency to molecular bromine (Br2), hypobromous acid (HOBr), bromine oxide (BrO), and hydrogen bromide (HBr) as soluble bromide (Br-) was 0.9±0.1, 1.06+0.30/-0.35, 0.4±0.1, and 0.95±0.1, respectively. These efficiency factors were used to estimate soluble bromide levels along the DC-8 flight track of 17 April 2008 from photochemical calculations constrained to in situ BrO measured by CIMS. During this flight, the highest levels of soluble bromide and BrO were observed and atmospheric conditions were ideal for the space-borne observation of BrO. The good agreement (R2 = 0.76; slope = 0.95; intercept = -3.4 pmol mol-1) between modeled and observed soluble bromide, when BrO was above detection limit (>2 pmol mol-1) under unpolluted conditions (NO<10 pmol mol-1), indicates that the CIMS BrO measurements were consistent with the MC soluble bromide and that a well characterized MC can be used to derive mixing ratios of some reactive bromine compounds. Tropospheric BrO vertical column densities (BrOVCD) derived from CIMS BrO observations compare well with BrOTROPVCD from OMI on 17 April 2008.

  13. Characterization of soluble bromide measurements and a case study of BrO observations during ARCTAS

    NASA Astrophysics Data System (ADS)

    Liao, J.; Huey, L. G.; Scheuer, E.; Dibb, J. E.; Stickel, R. E.; Tanner, D. J.; Neuman, J. A.; Nowak, J. B.; Choi, S.; Wang, Y.; Salawitch, R. J.; Canty, T.; Chance, K.; Kurosu, T.; Suleiman, R.; Weinheimer, A. J.; Shetter, R. E.; Fried, A.; Brune, W.; Anderson, B.; Zhang, X.; Chen, G.; Crawford, J.; Hecobian, A.; Ingall, E. D.

    2011-09-01

    A focus of the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) mission was examination of bromine photochemistry in the spring time, high latitude troposphere based on aircraft and satellite measurements of BrO and related species. The NASA DC-8 aircraft utilized a chemical ionization mass spectrometry (CIMS) instrument to measure BrO and a mist chamber (MC) to measure soluble bromide. We have determined that the MC detection efficiency to molecular bromine (Br2), hypobromous acid (HOBr), bromine oxide (BrO), and hydrogen bromide (HBr) as soluble bromide (Br-) was 0.9±0.1, 1.06±0.30, 0.4±0.1, and 0.95±0.1, respectively. These efficiency factors were used to estimate soluble bromide levels along the DC-8 flight track of 17 April 2008 from photochemical calculations constrained to in situ BrO measured by CIMS. During this flight, the highest levels of soluble bromide and BrO were observed and atmospheric conditions were ideal for the space-borne observation of BrO. The good agreement (R2 = 0.76; slope = 0.98; intercept = -3.5 pptv) between modeled and observed soluble bromide, when BrO was above detection limit (>2 pptv) under unpolluted conditions (NO < 100 pptv), indicates that the CIMS BrO measurements were consistent with the MC soluble bromide. Tropospheric BrO vertical column densities (BROTROPVCD) derived from CIMS BrO observations compare well with BROTROPVCD from OMI on 17 April 2008.

  14. A novel explicit approach to model bromide and pesticide transport in soils containing macropores

    NASA Astrophysics Data System (ADS)

    Klaus, J.; Zehe, E.

    2011-01-01

    The present study tests whether an explicit treatment of worm burrows is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in the spatially highly resolved model domain. A recent Monte Carlo study (Klaus and Zehe, 2010) revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide and Isoproturon (IPU) for the 13 spatial model setups, which performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of IPU, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

  15. Utility of bromide and heat tracers for aquifer characterization affected by highly transient flow conditions

    NASA Astrophysics Data System (ADS)

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

    2012-08-01

    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.

  16. 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

  17. [Successful lobectomy in 3 lung cancer cases with severe COPD after treatment with tiotropium bromide].

    PubMed

    Matsuyama, Wataru; Suetsugu, Takayuki; Kawabata, Takashi; Kubota, Shingo; Iwakawa, Jun; Higashimoto, Ikkou; Osame, Mitsuhiro; Arimura, Kimiyoshi

    2007-02-01

    It is well known that lung cancer patients with severe chronic obstructive pulmonary disease (COPD) have a higher risk of postoperative complications than patients without COPD. However, the information regarding preoperative treatment to improve pulmonary function of the lung cancer patients with severe COPD is limited. Here, we report 3 lung cancer cases with severe COPD. Although all patients received medication without tiotropium bromide in combination with pulmonary rehabilitation for 1 or 2 months, their pulmonary function did not improve and the predicted postoperative FEV1/predicted FEV1 was below 40% in all cases. After the approval in Japan for use of tiotropium bromide in the treatment of COPD, all patients were treated with tiotropium bromide. The pulmonary function in all patients improved 2-4 weeks after the start of tiotropium bromide, and we performed lobectomy safely. Currently all patients maintain good pulmonary function without recurrence of lung cancer. We propose that treatment of tiotropium bromide might be one of the effective preoperative methods to improve pulmonary function of lung cancer patients with severe COPD.

  18. Assessment of cytotoxicity of carbon nanoparticles using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) cell viability assay.

    PubMed

    Schrand, Amanda M; Lin, Jonathan B; Hussain, Saber M

    2012-01-01

    Ever since the discovery of carbon nanotubes, there has been an increasing interest in technologies that rely upon these incredibly small particles for their unique properties. However, assessment of their biological consequences has been riddled with assay limitations. Here, we describe application of a 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium cell viability assay to study cytotoxicity of various carbon-based nanomaterials on cells and discuss some pitfalls of this method.

  19. Rocuronium Bromide Inhibits Inflammation and Pain by Suppressing Nitric Oxide Production and Enhancing Prostaglandin E2 Synthesis in Endothelial Cells

    PubMed Central

    2016-01-01

    Purpose Rocuronium bromide is a nondepolarizing neuromuscular blocking drug and has been used as an adjunct for relaxation or paralysis of the skeletal muscles, facilitation of endotracheal intubation, and improving surgical conditions during general anesthesia. However, intravenous injection of rocuronium bromide induces injection pain or withdrawal movement. The exact mechanism of rocuronium bromide-induced injection pain or withdrawal movement is not yet understood. We investigated whether rocuronium bromide treatment is involved in the induction of inflammation and pain in vascular endothelial cells. Methods For this study, calf pulmonary artery endothelial (CPAE) cells were used, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Western blot, nitric oxide detection, and prostaglandin E2 immunoassay were conducted. Results Rocuronium bromide treatment inhibited endothelial nitric oxide synthase and suppressed nitric oxide production in CPAE cells. Rocuronium bromide activated cyclooxygenase-2, inducible nitric oxide synthase and increased prostaglandin E2 synthesis in CPAE cells. Conclusions Rocuronium bromide induced inflammation and pain in CPAE cells. Suppressing nitric oxide production and enhancing prostaglandin E2 synthesis might be associated with rocuronium bromide-induced injection pain or withdrawal movement. PMID:28043117

  20. 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

  1. 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

  2. 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

    2016-09-06

    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.

  3. Kinetics adsorption study of the ethidium bromide by graphene oxide as adsorbent from aqueous matrices

    NASA Astrophysics Data System (ADS)

    Rajabi, M.; Moradi, O.; Zare, K.

    2017-01-01

    In this study of ethidium bromide, adsorption from aqueous matrices by graphene oxide as adsorbent was investigated. Influencing parameters in the adsorption study included contact time, temperature, and pH. The optimum time was selected 17 min, and the best value of pH was determined at 8. All adsorption experiments were performed at 298 K temperature. The maximum wavelength of ethidium bromide was 475 nm. The Elovich, four types of the pseudo-second-order, the pseudo-first-order, and intra-particle diffusion kinetic adsorption models were used for kinetic study, and the results show that adsorption of ethidium bromide on graphene oxide surface best complied with type (I) of the pseudo-second-order kinetic model.

  4. A comparison between the gastric and salivary concentration of iodide, pertechnetate, and bromide in man

    PubMed Central

    Harden, R. McG.; Alexander, W. D.; Shimmins, J.; Chisholm, D.

    1969-01-01

    The concentration of iodide (I−) and pertechnetate (TcO4−) and bromide (Br−) has been measured simultaneously in gastric juice and parotid saliva. The combined gastric and salivary clearance for iodide and pertechnetate is more than twice the clearance of these ions by the thyroid gland. The concentration of the ions was in the order I−>TcO4−>Br− in both gastric juice and saliva. Differences exist between the secretion of iodide, pertechnetate, and bromide. Bromide, in contrast to iodide and pertechnetate, was found to be more concentrated in gastric juice than in saliva. The ratio of the iodide to pertechnetate clearance was greater in gastric juice than in saliva. PMID:5358585

  5. Characterization of micelle formation of dodecyldimethyl-N-2-phenoxyethylammonium bromide in aqueous solution.

    PubMed

    Khatua, Dibyendu; Gupta, Abhisek; Dey, Joykrishna

    2006-06-01

    Aggregation behavior of dodecyldimethyl-N-2-phenoxyethylammonium bromide commonly called domiphen bromide (DB) was studied in aqueous solution. The Krafft temperature of the surfactant was measured. The surfactant has been shown to form micellar structures in a wide concentration range. The critical micelle concentration was determined by surface tension, conductivity, and fluorescence methods. The conductivity data were also employed to determine the degree of surfactant counterion dissociation. The changes in Gibb's free energy, enthalpy, and entropy of the micellization process were determined at different temperature. The steady-state fluorescence quenching measurements with pyrene and N-phenyl-1-naphthylamine as fluorescence probes were performed to obtain micellar aggregation number. The results were compared with those of dodecyltrimethylammonium bromide (DTAB) surfactant. The micelle formation is energetically more favored in DB compared to that in DTAB. The 1H-NMR spectra were used to show that the 2-phenoxyethyl group, which folds back onto the micellar surface facilitates aggregate formation in DB.

  6. 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.

  7. [Extraction-spectrophotometric determination of carbethopendecinium-bromide in drug preparations].

    PubMed

    Lasková, M; Blesová, M

    2003-09-01

    The paper elaborated the conditions for the determination of carbethopendecinium bromide with bromthymol blue and methyl orange (concentration of the drug and the colouring agent, pH of the aqueous phase, period of extraction with chloroform). Within a carbethopendecinium bromide concentration range of 1.10(-5) to 6.10(-5) mol/l, the linear dependence of absorbance of the ion-associate with the colouring agent on concentration was confirmed. At pH 3 and pH 10, the above-described procedure was used to determine the content of carbethopendecinium bromide in medicinal preparations (eye and nasal drops) using the calibration curve and comparison with one standard. The results were reproducible and the found deviations from the declared content ranged within a tolerance of +/- 10%.

  8. 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.

  9. In-Depth Assessment of the Palladium-Catalyzed Fluorination of Five-Membered Heteroaryl Bromides.

    PubMed

    Milner, Phillip J; Yang, Yang; Buchwald, Stephen L

    2015-10-12

    A thorough investigation of the challenging Pd-catalyzed fluorination of five-membered heteroaryl bromides is presented. Crystallographic studies and density functional theory (DFT) calculations suggest that the challenging step of this transformation is C-F reductive elimination of five-membered heteroaryl fluorides from Pd(II) complexes. On the basis of these studies, we have found that various heteroaryl bromides bearing phenyl groups in the ortho position can be effectively fluorinated under catalytic conditions. Highly activated 2-bromoazoles, such as 8-bromocaffeine, are also viable substrates for this reaction.

  10. Lithium bromide-induced structural changes in a nickel bis-alkoxide complex.

    PubMed

    Ichiokai, Hiromi; Vicic, David A

    2013-01-01

    The bis-alkoxide [(DEAMP)2Ni] (1, DEAMP = 1-(diethylamino)-2-methylpropan-2-olate) was found to react with trace amounts of lithium bromide to afford the bis-LiBr adduct 2, in which the oxygens of the DEAMP ligand coordinate to lithium to form a chiral-at-metal complex. This new complex is five-coordinate at nickel, and contains nickel and oxygen atoms which are all chiral. One diastereomer precipitates from pentane solution. The two lithium ions rigidify the new structure in the solid state by coordinating to the oxygen and bromide atoms.

  11. One-pot synthesis of 1-iodoalkynes and trisubstituted alkenes from benzylic and allylic bromides.

    PubMed

    Pelletier, Guillaume; Lie, Sharon; Mousseau, James J; Charette, André B

    2012-11-02

    1-Iodoalkynes are formed in moderate to high yields from readily accessible benzylic and allylic alkyl bromides by a one-pot homologation/double elimination procedure with iodoform (CHI(3)). The developed conditions include facile purification and avoid the use of an excess of triphenylphosphine (PPh(3)), as described in classical Corey-Fuchs iodoalkynylation conditions. Replacing CHI(3) with CHI(2)Cl allows the isolation of the corresponding gem-(Z)-chloro-(E)-iodoalkene in good yield and stereoselectivity. Moreover, the use of benzhydryl bromides as nucleophiles enables the synthesis of trisubstituted alkenes under similar reaction conditions.

  12. Improved light olefin yield from methyl bromide coupling over modified SAPO-34 molecular sieves.

    PubMed

    Zhang, Aihua; Sun, Shouli; Komon, Zachary J A; Osterwalder, Neil; Gadewar, Sagar; Stoimenov, Peter; Auerbach, Daniel J; Stucky, Galen D; McFarland, Eric W

    2011-02-21

    As an alternative to the partial oxidation of methane to synthesis gas followed by methanol synthesis and the subsequent generation of olefins, we have studied the production of light olefins (ethylene and propylene) from the reaction of methyl bromide over various modified microporous silico-aluminophosphate molecular-sieve catalysts with an emphasis on SAPO-34. Some comparisons of methyl halides and methanol as reaction intermediates in their conversion to olefins are presented. Increasing the ratio of Si/Al and incorporation of Co into the catalyst framework improved the methyl bromide yield of light olefins over that obtained using standard SAPO-34.

  13. Bromidotetra-kis-(2-ethyl-1H-imidazole-κN (3))copper(II) bromide.

    PubMed

    Godlewska, Sylwia; Kelm, Harald; Krüger, Hans-Jörg; Dołęga, Anna

    2012-12-01

    The Cu(II) ion in the title mol-ecular salt, [CuBr(C5H8N2)4]Br, is coordinated in a square-pyramidal geometry by four N atoms of imidazole ligands and one bromide anion in the apical position. In the crystal, the ions are linked by N-H⋯Br hydrogen bonds involving both the coordinating and the free bromide species as acceptors. A C-H⋯Br inter-action is also observed. Overall, a three-dimensional network results.

  14. 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.

  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. In-Depth Assessment of the Palladium-Catalyzed Fluorination of Five-Membered Heteroaryl Bromides

    PubMed Central

    2015-01-01

    A thorough investigation of the challenging Pd-catalyzed fluorination of five-membered heteroaryl bromides is presented. Crystallographic studies and density functional theory (DFT) calculations suggest that the challenging step of this transformation is C–F reductive elimination of five-membered heteroaryl fluorides from Pd(II) complexes. On the basis of these studies, we have found that various heteroaryl bromides bearing phenyl groups in the ortho position can be effectively fluorinated under catalytic conditions. Highly activated 2-bromoazoles, such as 8-bromocaffeine, are also viable substrates for this reaction. PMID:27056379

  17. Improved synthesis of aryltriethoxysilanes via palladium(0)-catalyzed silylation of aryl iodides and bromides with triethoxysilane.

    PubMed

    Manoso, A S; DeShong, P

    2001-11-02

    The scope of the palladium-catalyzed silylation of aryl halides with triethoxysilane has been expanded to include aryl bromides. A more general Pd(0) catalyst/ligand system has been developed that activates bromides and iodides: palladium(0) dibenzylideneacetone (Pd(dba)(2)) is activated with 2-(di-tert-butylphosphino)biphenyl (Buchwald's ligand) (1:2 mol ratio of Pd/phosphine). Electron-rich para- and meta-substituted aryl halides (including unprotected aniline and phenol derivatives) undergo silylation to form the corresponding aryltriethoxysilane in fair to excellent yield; however, ortho-substituted aryl halides failed to be silylated.

  18. Structure and dynamics of cetyltrimethylammonium bromide water-in-oil microemulsions

    SciTech Connect

    Lang, J.; Zana, R. ); Mascolo, G.; Luisi, P.L. )

    1990-04-05

    The state of water, the droplet size, and interdroplet exchange of reactants between colliding droplets have been investigated by NMR, time-resolved fluorescence quenching, and electrical conductivity in water-in-oil microemulsions made of cetyltrimethylammonium bromide (CTAB) in chloroform/isooctane (2/1, v/v). The effect of the two additives cetyl bromide (CB) and trimethylamine (TMA) on the properties of the droplets has also been investigated. No interdroplet exchange of reactants has been detected in the absence of additives.

  19. 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.

  20. Screen anticancer drug in vitro using resonance light scattering technique.

    PubMed

    Chen, Zhanguang; Liu, Guoliang; Chen, Meizhen; Xu, Benjie; Peng, Yurui; Chen, Maohuai; Wu, Mingyao

    2009-02-15

    An in vitro screening model using resonance light scattering (RLS) technique with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) reagent as the reactive probe to target cancer cell was firstly developed. In this model, MTT was reduced by viable cancer cells to produce a purple formazan. Cell viability was proportional to the number of formazan induced strong light scattering signal. The inhibition rate of anticancer drug was found to vary inversely with the H(22)-MTT system RLS intensity. So it was intuitive to see the sequence of the tumor suppressive activity of six anticancer drugs without data processing by RLS/MTT screening spectra. Compared with the traditional MTT method, this method has high sensitivity, low detection limit and quite intuitive screening results which were identical to those obtained from the MTT colorimetric assay.

  1. In vitro cytotoxicity assays of solid lipid nanoparticles in epithelial and dermal cells

    NASA Astrophysics Data System (ADS)

    Ridolfi, D. M.; Marcato, P. D.; Machado, D.; Silva, R. A.; Justo, G. Z.; Durán, N.

    2011-07-01

    In recent years, the interest in nanostructured systems to drug delivery has increased because they offer several advantages over conventional dosage forms. Solid Lipid Nanoparticles (SLN) have been highlighted among these systems because they have advantages such as high physical stability, protection against drug degradation and ease of scale-up and manufacturing, without using organic solvent. The aim of this work was to evaluate the potential of SLN, by in vitro cytotoxicity assays, for dermal drug delivery. SLN of three different lipids were prepared by hot high pressure homogenization and the cytotoxicity was assessed by 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test in mouse 3T3 fibroblasts and human HaCaT keratinocytes. SLN showed no cytotoxic potential suggesting a great potential for dermal application.

  2. PEG-phospholipid-encapsulated bismuth sulfide and CdSe/ZnS quantum dot core-shell nanoparticle and its computed tomography/fluorescence performance

    NASA Astrophysics Data System (ADS)

    Chen, Jun; Yang, Xiao-Quan; Qin, Meng-Yao; Zhang, Xiao-Shuai; Xuan, Yang; Zhao, Yuan-Di

    2015-11-01

    In this paper, polyethylene glycol-phospholipid structure is used to synthesize hybrid cluster of 40-50 nm diameter that contains hydrophobic bismuth sulfide nanoparticles and CdSe/ZnS quantum dots. The composite probe's toxicity, CT imaging, and fluorescence imaging performance are also studied. Experimental results show that the nanocomposite hybrid cluster has obvious CT contrast enhancement and fluorescence imaging capability in vitro even after cellular uptake. It gives a CT number of 700 (Hounsfield units) at 15 mg/mL, higher than that of the current iobitridol CT contrast agent. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide experiment reveals that it has low cytotoxicity at concentration up to of 3.14 mg/mL of Bi, indicating the composite probe has potential ability for CT and fluorescence bimodal imaging.

  3. Sensitivity of two in vitro assays for evaluating plant activity against the infective stage of Haemonchus contortus strains.

    PubMed

    Al-Rofaai, A; Rahman, W A; Abdulghani, Mahfoudh

    2013-02-01

    The sensitivity of larval paralysis assay (LPA) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide-formazan (MTT-formazan) assay was compared to evaluate the anthelmintic activity of plant extracts. In this study, the methanolic extract of Azadirachta indica (neem) was evaluated for its activity against the infective-stage larvae (L(3)) of susceptible and resistant Haemonchus contortus strains using the two aforementioned assays. In both in vitro assays, the same serial concentrations of the extract were used, and the median lethal concentrations were determined to compare the sensitivity of both assays. The results revealed a significant difference (P < 0.05) in the sensitivity of the LPA and the MTT-formazan assay. The MTT-formazan assay is more feasible for practical applications because it measured the L(3) mortality more accurately than LPA. This study may help find a suitable assay for investigating the anthelmintic activity of plant extracts against trichostrongylid nematodes.

  4. DEVD-Based Hydrogelator Minimizes Cellular Apoptosis Induction

    PubMed Central

    Tang, An-Ming; Wang, Wei-Juan; Mei, Bin; Hu, Wang-Lai; Wu, Mian; Liang, Gao-Lin

    2013-01-01

    Herein, we report the rational design of a DEVD-based heptapeptide hydrogelator 1 which is susceptible to caspase-3 (CASP3), and its isomeric control hydrogelator 2 with a DEDV-based heptapeptide sequence. Self-assembly of 1 in water results in flexuous, long nanofibers to form supramolecular hydrogel I with higher mechanical strength than that of hydrogel II which is composed of rigid, short nanofibers of 2. In vitro enzymatic analysis indicated that 1 is susceptive to CASP3 while 2 is not. 3-(4,5-dimethylthiazol-2-yl) 2,5 diphenyl tetrazolium bromide (MTT) and Western blot analyses indicated that DEDV-based hydrogelator 2 induces cell death via apoptotic pathway while the DEVD-based hydrogelator 1 minimizes cellular apoptosis induction. PMID:23673405

  5. Toxicity study of cerium oxide nanoparticles in human neuroblastoma cells.

    PubMed

    Kumari, Monika; Singh, Shailendra Pratap; Chinde, Srinivas; Rahman, Mohammed Fazlur; Mahboob, Mohammed; Grover, Paramjit

    2014-01-01

    The present study consisted of cytotoxic, genotoxic, and oxidative stress responses of human neuroblastoma cell line (IMR32) following exposure to different doses of cerium oxide nanoparticles (CeO2 NPs; nanoceria) and its microparticles (MPs) for 24 hours. Cytotoxicity was evaluated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assays whereas genotoxicity was assessed using the cytokinesis-block micronucleus and comet assays. A battery of assays including lipid peroxidation, reactive oxygen species (ROS), hydrogen peroxide, reduced glutathione, nitric oxide, glutathione reductase, glutathione peroxidase, superoxide dismutase, catalase, and glutathione S-transferase were performed to test the hypothesis that ROS was responsible for the toxicity of nanoceria. The results showed that nanosized CeO2 was more toxic than cerium oxide MPs. Hence, further study on safety evaluation of CeO2 NPs on other models is recommended.

  6. Cytotoxicities and genotoxicities of cements based on calcium silicate and of dental formocresol.

    PubMed

    Ko, Hyunjung; Jeong, Youngdan; Kim, Miri

    2017-03-01

    Increasing interest is being paid to the toxicities of dental materials. The purpose of this study was to determine the cytotoxicities and genotoxicities of endodontic compounds to Chinese hamster ovary (CHO-K1) reproductive cells. Cultured CHO-K1 cells were treated with dental formocresol, two types of calcium hydroxide paste, and two types of mineral trioxide aggregate cement for 24h. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay was performed on each culture, and the micronucleus frequency was determined by performing a micronucleus assay. Alkaline comet assay and γ-H2AX immunofluorescence assay were used to detect DNA damage. Out of the five materials tested, only dental formocresol significantly increased DNA damage. The mineral trioxide aggregate cements based on calcium silicate were not found to be potentially genotoxic. The data suggest that dental formocresol should not be recommended for use in vital pulp therapy on young teeth.

  7. 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.

  8. Cell viability and adhesion on diamond-like carbon films containing titanium dioxide nanoparticles

    NASA Astrophysics Data System (ADS)

    Wachesk, C. C.; Pires, C. A. F.; Ramos, B. C.; Trava-Airoldi, V. J.; Lobo, A. O.; Pacheco-Soares, C.; Marciano, F. R.; Da-Silva, N. S.

    2013-02-01

    The combination of low friction, wear resistance, high hardness, biocompatibility and chemical inertness makes diamond-like carbon (DLC) films suitable in a numerous applications in biomedical engineering. The cell viability and adhesion of L929 mouse fibroblasts was investigated using two different colorimetric assays: (i) 2-(4,5-dimethyl-2-thiazolyl)-3,5-diphenyl-2H-tetrazolium bromide (MTT), and (ii) lactate dehydrogenase (LDH). The films were growth on 316L stainless steel substrates using plasma enhanced chemical vapor deposition technique from a dispersion of TiO2 nanopowder in hexane. The increasing concentration of TiO2 nanoparticles in DLC films enhanced the mitochondrial activity and decreases the LDH activity on these samples. Fluorescence and scanning electron microscopy corroborate the results. These experiments show the potential use of DLC and TiO2-DLC films in biomedical applications.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Synthesis of biocompatible glycodendrimer based on fluorescent perylene bisimides and its bioimaging.

    PubMed

    Wang, Ke-Rang; An, Hong-Wei; Rong, Rui-Xue; Cao, Zhi-Ran; Li, Xiao-Liu

    2014-04-01

    A novel water-soluble fluorescent glycodendrimer based on perylene bisimides is synthesized, which exhibits high fluorescence quantum yield of 54%. While the binding interactions of PBI-Man with Concanavalin A (Con A) are studied by fluorescence spectra and CD spectra, which show strong binding affinity for Con A with the binding constant of 3.8 × 10(7) m(-1) for monomeric mannose, nearly four orders of magnitude higher affinity than the monovalent mannose ligand. Furthermore, the fluorescence imaging of macrophage cell with PBI-Man is investigated, and shows selectively binding interaction with the mannose receptor-medicated cell entry. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) activities of PBI-Man show that PBI-Man as a biocompatible agent is noncytotoxic to living cells.

  14. Antitumor and antioxidant activity of protocatechualdehyde produced from Streptomyces lincolnensis M-20.

    PubMed

    Kim, Kyoung-Ja; Kim, Mi-Ae; Jung, Jee-Hyung

    2008-12-01

    We characterized the biological functions of protocatechualdehyde (PA) isolated from the butanol extract of culture supernatant from Streptomyces lincolnensis M-20. Following butanol extraction, it was purified by silica gel and Sephadex LH-20 column chromatography. PA was analyzed by Furier Transform Infrared Spectroscopy (FT-IR), Gas chromatograph-Mass Spectrometer (GC-MS), and Nuclear Magnetic Resonance (NMR). PA had potent antioxidant activity, as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Antitumor activity against MCF-7 human breast cancer cells was evaluated by the 3-(4,5-dimethylthazol-2-yl)-2,5-diphenyl tetrazolium-bromide (MTT) assay. PA treatment (0 approximately 150 muM) dose-dependently blocked apoptosis, as shown by improved cell viability and inter-nucleosomal DNA fragmentation. Our findings suggest that Streptomyces lincolnensis M-20, a lincomycin producer, also produces protocatechualdehyde.

  15. 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...

  16. 40 CFR 180.123a - Inorganic bromide residues in peanut hay and peanut hulls; statement of policy.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 24 2014-07-01 2014-07-01 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...

  17. 40 CFR 180.123a - Inorganic bromide residues in peanut hay and peanut hulls; statement of policy.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 25 2013-07-01 2013-07-01 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...

  18. 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...

  19. 40 CFR 180.123a - Inorganic bromide residues in peanut hay and peanut hulls; statement of policy.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 25 2012-07-01 2012-07-01 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...

  20. 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

  1. EPA Takes Action Against Illegal Methyl Bromide Use in Puerto Rico

    EPA Pesticide Factsheets

    (New York, N.Y.) As part of its ongoing work to address the illegal use of toxic pesticides containing methyl bromide in the Caribbean, the U.S. Environmental Protection Agency has issued legal complaints against two individuals and a pest control company

  2. 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.

  3. 78 FR 36507 - Notice of Availability of a Treatment Evaluation Document; Methyl Bromide Fumigation of Blueberries

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-18

    ... schedule for methyl bromide fumigation of blueberries for Mediterranean fruit fly and South American fruit... explains why we have determined that it is effective at neutralizing these fruit flies. We are making the... risk from two fruit fly species, Ceratitis capitata (Mediterranean fruit fly, or Medfly) and...

  4. Methyl Bromide Alternatives Area-Wide Pest Management Project - South Atlantic Progress Report

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protocols and Standard Operational Procedures (SOPs) were developed for collecting environmental and soil edaphic information during and after application of methyl bromide alternatives. Parameters measured included soil moisture, soil bulk density, percent moisture at field capacity (-0.3 bars wat...

  5. IDENTIFICATION OF NEW DRINKING WATER DISINFECTION BY-PRODUCTS FORMED IN THE PRESENCE OF BROMIDE

    EPA Science Inventory

    Using a combination of mass spectrometry and infrared spectroscopy, disinfection by-products (DBPs) were identified in ozonated drinking water containing elevated bromide levels, and in ozonated water treated with secondary chlorine or chloramine. Only one brominated by-product-d...

  6. Removal of methyl bromide in coastal seawater: Chemical and biological rates

    NASA Astrophysics Data System (ADS)

    King, Daniel B.; Saltzman, Eric S.

    1997-08-01

    A stable isotope tracer technique was used to investigate the loss rate of methyl bromide in surface ocean waters. Unfiltered and 0.2 μm-filtered or autoclaved aliquants of Biscayne Bay seawater samples were spiked with 13CH3Br at roughly 10-100 times ambient concentrations (50-800 pM) and incubated for 10-30 hours. The concentration of 13CH3Br was monitored using gas chromatography with isotope dilution mass spectrometry, with CD3Br as the isotope spike. Removal rates in unfiltered aliquants were significantly faster than in the 0.2 μm-filtered or autoclaved aliquants, indicating that some of the loss of methyl bromide was associated with particulate matter. Filtration experiments indicate that the particulate material responsible for methyl bromide loss is between 0.2 and 1.2 μm in diameter, suggesting that bacteria are likely to be responsible. The particulate-related removal of methyl bromide was inhibited by autoclaving, supporting a biological mechanism.

  7. Charging of silver bromide aqueous interface: evaluation of interfacial equilibrium constants from surface potential data.

    PubMed

    Preočanin, Tajana; Supljika, Filip; Kallay, Nikola

    2010-06-01

    A single crystal silver bromide electrode (SCr-AgBr) was used to measure the inner surface potential (Ψ(0)) at the silver bromide aqueous electrolyte interface as a function of the activities of Br(-) and Ag(+). Absolute values of the surface potential were calculated from electrode potentials of SCr-AgBr using the value of point of zero charge (pBr(pzc)=6.9 [H.A. Hoyen, R.M. Cole, J. Colloid Interface Sci. 41 (1972) 93.]) as the value of point of zero potential. Measurements were performed in potassium nitrate aqueous solutions. The Ψ(0)(pBr) function was linear and slightly dependent on the ionic strength. The reduction values of the slope with respect to the Nernst equation, expressed by the α coefficient, were 0.880,0.935, and 0.950 at ionic strengths of 10(-4), 10(-3), and 10(-2) mol dm(-3), respectively. The results were successfully interpreted by employing the surface complexation model, developed originally for metal oxides and adapted for silver halides. The thermodynamic ("intrinsic") equilibrium constants for binding of bromide (K(n)(∘)) and silver (K(p)(∘)) ions on the corresponding sites at the silver bromide surface were evaluated as lgK(n)(∘)=3.98; lgK(p)(∘)=2.48. Symmetrical counterion surface association was assumed and equilibrium constants were obtained as lgK(NO(3)(-))(∘)=lgK(K(+))(∘)=4.30.

  8. Chlorine utilization during trihalomethane formation in the presence of ammonia and bromide

    SciTech Connect

    Amy, G.L.; Chadik, P.A.; King, P.H.; Cooper, W.J.

    1984-10-01

    The chlorination of humic substances in the presence of ammonia and bromide and the resultant formation of trihalomethanes (THM) are described. The presence of ammonia substantially reduced but did not eliminate THM production during the chlorination of waters containing humic substances. The presence of bromide ion in waters containing humic substances leads to increased THM formation, both in the presence and in the absence of ammonia. In waters containing ammonia, bromide, and humic substances, brominated haloforms can form upon chlorination. Brominated species comprise a larger portion of the total THMs at higher chlorine doses within the free chlorine region of the breakpoint curve than at lower dose in the subbreakpoint region. Although the THM formation reaction is slow and may not be complete even after 1 week of reaction time, the initial rate of formation is competitive with the relatively rapid reactions of bromide oxidation and chloramine formation. After free chlorine is converted to chloramines, THM production should theoretically cease. THMs will form in parallel with chloramine formation. This behavior has important implications for water utilities that use a raw water source containing low but significant levels of ammonia such as the Biscayne Aquifer, or are considering chloramine disinfection as a THM control strategy.

  9. The use of agricultural by-products to capture methyl bromide following post-harvest fumigation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Activated carbons were prepared from plum and peach stone as well as almond and walnut shell and comparatively evaluated as sorbents to minimize the atmospheric emission of methyl bromide following postharvest fumigations. A variety of methods were used to make the activated carbons and each is desc...

  10. 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.

  11. Study of the antibacterial and antifungal activities of synthetic benzyl bromides, ketones, and corresponding chalcone derivatives

    PubMed Central

    Shakhatreh, Muhamad Ali K; Al-Smadi, Mousa L; Khabour, Omar F; Shuaibu, Fatima A; Hussein, Emad I; Alzoubi, Karem H

    2016-01-01

    Several applications of chalcones and their derivatives encouraged researchers to increase their synthesis as an alternative for the treatment of pathogenic bacterial and fungal infections. In the present study, chalcone derivatives were synthesized through cross aldol condensation reaction between 4-(N,N-dimethylamino)benzaldehyde and multiarm aromatic ketones. The multiarm aromatic ketones were synthesized through nucleophilic substitution reaction between 4-hydroxy acetophenone and benzyl bromides. The benzyl bromides, multiarm aromatic ketones, and corresponding chalcone derivatives were evaluated for their activities against eleven clinical pathogenic Gram-positive, Gram-negative bacteria, and three pathogenic fungi by the disk diffusion method. The minimum inhibitory concentration was determined by the microbroth dilution technique. The results of the present study demonstrated that benzyl bromide derivatives have strong antibacterial and antifungal properties as compared to synthetic chalcone derivatives and ketones. Benzyl bromides (1a and 1c) showed high ester activity against Gram-positive bacteria and fungi but moderate activity against Gram-negative bacteria. Therefore, these compounds may be considered as good antibacterial and antifungal drug discovery. However, substituted ketones (2a–b) as well as chalcone derivatives (3a–c) showed no activity against all the tested strains except for ketone (2c), which showed moderate activity against Candida albicans. PMID:27877017

  12. SYBR safe(TM) efficiently replaces ethidium bromide in Aspergillus fumigatus gene disruption.

    PubMed

    Canela, H M S; Takami, L A; Ferreira, M E S

    2017-02-08

    Invasive aspergillosis is a disease responsible for high mortality rates, caused mainly by Aspergillus fumigatus. The available drugs are limited and this disease continues to occur at an unacceptable frequency. Gene disruption is essential in the search for new drug targets. An efficient protocol for A. fumigatus gene disruption was described but it requires ethidium bromide, a genotoxic agent, for DNA staining. Therefore, the present study tested SYBR safe(TM), a non-genotoxic DNA stain, in A. fumigatus gene disruption protocol. The chosen gene was cipC, which has already been disrupted successfully in our laboratory. A deletion cassette was constructed in Saccharomyces cerevisiae and used in A. fumigatus transformation. There was no statistical difference between the tested DNA stains. The success rate of S. cerevisiae transformation was 63.3% for ethidium bromide and 70% for SYBR safe(TM). For A. fumigatus gene disruption, the success rate for ethidium bromide was 100 and 97% for SYBR safe(TM). In conclusion, SYBR safe(TM) efficiently replaced ethidium bromide, making this dye a safe and efficient alternative for DNA staining in A. fumigatus gene disruption.

  13. 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...

  14. Kinetics and mechanism of the oxidation of bromide by periodate in aqueous acidic solution.

    PubMed

    Szél, Viktor; Csekő, György; Horváth, Attila K

    2014-11-13

    The periodate–bromide reaction has been studied spectrophotometrically mainly in excess of bromide ion, monitoring the formation of the total amount of bromine at 450 nm at acidic buffered conditions and at a constant ionic strength in the presence of a phosphoric acid/dihydrogen phosphate buffer. The stoichiometry of the reaction was established to be strictly IO4(–) + 2Br(–) + 2H(+) → Br2 + IO3(–) + H2O. The formal kinetic order of the reactants was found to be perfectly one and two in the cases of periodate and bromide, respectively, but that of the hydrogen ion lies between one and two. We have also provided experimental evidence that dihydrogen phosphate accelerates the formation of bromine, suggesting the appearance of strong buffer assistance. On the basis of the experiments, a simple two-step kinetic model is proposed involving BrIO3 as a key intermediate that perfectly explains all of the experimental findings. Furthermore, we have also shown that in huge excess of bromide, the apparent rate coefficient obtained from the individual curve fitting method of the absorbance–time series is necessarily independent of the initial periodate concentration that may falsely be interpreted as the rate of bromine formation is also independent of the concentration of periodate.

  15. Ninety-Day Subchronic Oral Toxicity Study of Pyridostigmine Bromide in Rats. Volume 1

    DTIC Science & Technology

    1990-05-01

    myasthenia gravis because of its relative lack of untoward effects in comparison with other anticholinesterases (2). This relative lack of clinical...treatment of myasthenia gravis . Objecrive of Study The objective of this study was to determine the 90-day subchronic toxicity of pyridostigmine bromide in

  16. 77 FR 31564 - Notice of Availability of a Treatment Evaluation Document; Methyl Bromide Fumigation of Cottonseed

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-29

    ... Animal and Plant Health Inspection Service Notice of Availability of a Treatment Evaluation Document... add to the Plant Protection and Quarantine Treatment Manual a treatment schedule for methyl bromide... prepared a treatment evaluation document that describes the new treatment schedule and explains why we...

  17. 76 FR 34700 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-14

    ... 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, 1-800-296-1996; also http://www.epa.gov/ozone/mbr . Technical Information: Bill Chism, U.S....

  18. 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...

  19. 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...

  20. 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...

  1. Highly efficient synthesis of phenols by copper-catalyzed hydroxylation of aryl iodides, bromides, and chlorides.

    PubMed

    Yang, Kai; Li, Zheng; Wang, Zhaoyang; Yao, Zhiyi; Jiang, Sheng

    2011-08-19

    8-Hydroxyquinolin-N-oxide was found to be a very efficient ligand for the copper-catalyzed hydroxylation of aryl iodides, aryl bromides, or aryl chlorides under mild reaction conditions. This methodology provides a direct transformation of aryl halides to phenols and to alkyl aryl ethers. The inexpensive catalytic system showed great functional group tolerance and excellent selectivity.

  2. Practical Cross-Coupling between O-Based Electrophiles and Aryl Bromides via Ni Catalysis.

    PubMed

    Cao, Zhi-Chao; Luo, Qin-Yu; Shi, Zhang-Jie

    2016-12-02

    Cross-coupling of various O-based electrophiles with aryl bromides was developed through Ni-catalyzed C-O activation in the presence of magnesium. Beside carboxylates, carbamates, and ethers, phenols exhibited excellent reactivity under modified conditions. This chemistry was featured as a simple and environmentally benign process with low catalyst loading and easy manipulations. The method exhibited broad substrate scopes.

  3. Efficient palladium-catalyzed coupling reactions of aryl bromides and chlorides with phenols.

    PubMed

    Hu, Tongjie; Schulz, Thomas; Torborg, Christian; Chen, Xiaorong; Wang, Jun; Beller, Matthias; Huang, Jun

    2009-12-21

    A convenient and general palladium-catalyzed coupling reaction of aryl bromides and chlorides with phenols was developed. Various functional groups such as nitriles, aldehydes, ketones and esters are well tolerated and the corresponding products are obtained in good to excellent yield.

  4. Synthesis of Vinyl Trifluoromethyl Thioethers via Copper-Mediated Trifluoromethylthiolation of Vinyl Bromides.

    PubMed

    Huang, Yangjie; Ding, Jianping; Wu, Chuyi; Zheng, Huidong; Weng, Zhiqiang

    2015-03-06

    A copper-mediated trifluoromethylthiolation of vinyl bromides has been developed. This method provides ready access to vinyl trifluoromethyl thioethers in good to high yields from simple, inexpensive starting materials. A broad substrate scope is achieved, and the reaction is compatible with various functional groups, including cyano, nitro, trifluoromethyl, alkoxy, amino, halide, and heterocyclic groups.

  5. 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.

  6. Methods to facilitate the adoption of alternatives to methyl bromide soil fumigation by California strawberry growers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The goal of this project is to facilitate the adoption of strawberry production systems that do not use methyl bromide (MB). The five year project initially focused on fumigant alternatives to MB. The project has resulted in increased use of barrier films that reduce fumigant emission. The focus s...

  7. 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...

  8. Neuropsychological Functioning in Gulf War Veterans Exposed to Pesticides and Pyridostigmine Bromide

    DTIC Science & Technology

    2008-08-01

    this sweeping pesticide review, the EPA also suggested that some OP pesticides may have endocrine disrupting properties at doses much lower than would...EPA because of its persistence in the environment, ability to bioaccumulate, potential as a carcinogen and evidence as an endocrine disruptor (http...War Veterans Exposed to Pesticides and Pyridostigmine Bromide PRINCIPAL INVESTIGATOR: Maxine Krengel, Ph.D. CONTRACTING

  9. 78 FR 32646 - Protection of Stratospheric Ozone: Request for Methyl Bromide Critical Use Exemption Applications...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-31

    ... on Substances that Deplete the Ozone Layer for industrialized countries and to allow EPA to provide a... 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,...

  10. 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,...

  11. 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.

  12. 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 ...

  13. Spectrophotometric quantitation of DNA on blots after ethanol-solubilization of the MTT-formazan from anti-digoxigenin-based detection of nucleic acids.

    PubMed

    Colgan, D J

    1993-01-01

    The tetrazolium salt, 3-(4,5-dimethyl-thiazolyl-2)-2,5-diphenyl tetrazolium bromide (MTT) has recently been established as a substitute for Nitro-blue tetrazolium (NBT) in stain mixtures using antibody-conjugated alkaline phosphatase for the location of proteins on Western blots (Heegaard, 1990). Experiments reported here show that MTT is as sensitive as NBT in digoxigenin-labeled probe localization (on nucleic acid blots) utilizing alkaline-phosphatase-labelled, anti-digoxigenin antibodies. Moreover, as the formazan from MTT is soluble in ethanol, it is shown that spectrophotometric quantitation can be used to estimate the amount of target DNA on dot and Southern blots. For dot blotting, pBR328 was used as the probe and pBR322 as target. For Southern blots, human rDNA was used as the probe and total genomic calf DNA as the target. Staining response was linear over at least six twofold DNA dilutions in both types of blot.

  14. A novel explicit approach to model bromide and pesticide transport in connected soil structures

    NASA Astrophysics Data System (ADS)

    Klaus, J.; Zehe, E.

    2011-07-01

    The present study tests whether an explicit treatment of worm burrows and tile drains as connected structures is feasible for simulating water flow, bromide and pesticide transport in structured heterogeneous soils at hillslope scale. The essence is to represent worm burrows as morphologically connected paths of low flow resistance in a hillslope model. A recent Monte Carlo study (Klaus and Zehe, 2010, Hydrological Processes, 24, p. 1595-1609) revealed that this approach allowed successful reproduction of tile drain event discharge recorded during an irrigation experiment at a tile drained field site. However, several "hillslope architectures" that were all consistent with the available extensive data base allowed a good reproduction of tile drain flow response. Our second objective was thus to find out whether this "equifinality" in spatial model setups may be reduced when including bromide tracer data in the model falsification process. We thus simulated transport of bromide for the 13 spatial model setups that performed best with respect to reproduce tile drain event discharge, without any further calibration. All model setups allowed a very good prediction of the temporal dynamics of cumulated bromide leaching into the tile drain, while only four of them matched the accumulated water balance and accumulated bromide loss into the tile drain. The number of behavioural model architectures could thus be reduced to four. One of those setups was used for simulating transport of Isoproturon, using different parameter combinations to characterise adsorption according to the Footprint data base. Simulations could, however, only reproduce the observed leaching behaviour, when we allowed for retardation coefficients that were very close to one.

  15. 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.

  16. 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.

  17. Comparison of salbutamol and ipratropium bromide versus salbutamol alone in the treatment of acute severe asthma.

    PubMed

    Hossain, A S; Barua, U K; Roy, G C; Sutradhar, S R; Rahman, I; Rahman, G

    2013-04-01

    The use of nebulized Ipratropium bromide, quaternary anticholinergic bronchodilators in combination with beta-agonist for the treatment of acute asthma in adults is controversial. In a view of different recommendation the present study is undertaken in Bangladeshi patients. Combination of inhaled Ipratropium bromide and Salbutamol provides greater bronchodilatation than mono therapy with Salbutamol alone in acute severe asthma. Patients of severe asthma (PEFR <50% of predicted) were enrolled into control group (Salbutamol only) and case (Salbutamol + Ipratropium bromide) group. After measurement of peak expiratory flow, patient received 3 doses of 2.5 mg Salbutamol (n=40) only or 3 doses of both 2.5mg Salbutamol and 500mcg Ipratropium bromide at an interval of 20 minutes (n=40) through a jet nebulizer. Peak flow was reassessed 30 & 60 minutes after treatment. Peak flow at baseline was similar in two groups. Then at 30 minutes after nebulization, the mean±SD percentage increase in peak flow was greater in combination group (60.01±35.01%) than Salbutamol group (44.47±25.03%) with difference of 16% (p=0.025). At 60 minutes the percentage increase in peak flow was about 32% greater in combination group than Salbutamol group (94.44±33.70% vs. 62.57±29.26%, p=0.000) and combination group reached percentage predicted peak flow more than 60% while Sabutamol group did not. Ipratropium Bromide and Salbutamol nebulized combinedly have better bronchodilating effect than Salbultamol alone in acute severe asthma.

  18. Superoxide produced by activated neutrophils efficiently reduces the tetrazolium salt, WST-1 to produce a soluble formazan: a simple colorimetric assay for measuring respiratory burst activation and for screening anti-inflammatory agents.

    PubMed

    Tan, A S; Berridge, M V

    2000-04-21

    Activation of the respiratory burst of granulocytes and macrophages by invading microorganisms is a key first line cellular defence against infection. Failure to generate this response leads to persistent life-threatening infection unless appropriate antibiotic treatment is given. The respiratory burst of neutrophils is usually measured spectrophotometrically by following ferricytochrome c reduction, and histologically by using the tetrazolium salt, nitroblue tetrazolium, which is reduced intracellularly to an insoluble formazan. In both assays, reduction is mediated by superoxide generated via NADPH oxidase. Because ferricytochrome c has a high molecular mass and high background absorbance at 550 nm, the assay lacks sensitivity and is not ideally suited to microplate measurement. We have circumvented these limitations by using the cell-impermeable, sulfonated tetrazolium salt, WST-1, which exhibits very low background absorbance and is efficiently reduced by superoxide to a stable water-soluble formazan with high molar absorptivity. This has permitted adaptation of the WST-1 assay to microplate format while retaining sensitivity. Reduction of WST-1 by activated human peripheral blood neutrophils correlated closely with ferricytochrome c reduction across a range of PMA concentrations and with time of activation by PMA and fMLP. Reduction of WST-1 was inhibited by 98% by superoxide dismutase (20 microg/ml) and by 88% by the NADPH oxidase inhibitor, diphenyleneiodinium (10 microM) but was resistant to catalase, azide and the NADH oxidase inhibitor, resiniferatoxin. WST-1 and ferricytochrome c reduction were also compared using xanthine/xanthine oxidase to generate superoxide. Under optimised assay conditions, both WST-1 and ferricytochrome c reduction were directly proportional to added xanthine. WST-1 generated approximately 2-fold greater increase in absorbance than ferricytochrome c at their respective wavelengths, and this translated into increased assay

  19. Improvement of Quality of Nonanesthetic Colonoscopy by Preoperative Administration of Pinaverium Bromide

    PubMed Central

    Wang, Xiao-Lin; Zhou, Jian-Ning; Ren, Li; Pan, Xiao-Li; Ren, Hong-Yu; Liu, Jun

    2017-01-01

    Background: Nonanesthetic colonoscopy is popular in clinical practice in China. However, intestinal spasms often result in a prolonged examination time, increased operating difficulties, decreased polyp detection rate, and failure to complete the procedure clinically. Therefore, exploring alternative approaches that can reduce the pain in patients during colonoscopy is of utmost importance, and finding the optimal preoperative administration to improve the quality of nonanesthetic colonoscopy is also necessary. This study aimed to investigate the effects of the prophylactic administration of pinaverium bromide before colonoscopy and the effects of pinaverium bromide alone at different time points or combined with scopolamine butylbromide. Methods: A randomized controlled trial was performed on a cohort of 1000 patients who underwent colonoscopy in outpatient clinic of Wuhan Union Hospital. The patients were randomly assigned to the following groups: Group A, given oral pinaverium bromide (100 mg, three times a day) one day before examination combined with intramuscular injection of scopolamine butylbromide (20 mg) 10 min before colonoscopy; Group B0, given pinaverium bromide alone on the day of colonoscopy (100 mg, three times a day); Group B1, given pinaverium bromide alone (100 mg, three times a day) one day before colonoscopy; Group B2, given pinaverium bromide alone (100 mg, three times a day) two days before colonoscopy; and Group C, given scopolamine butylbromide alone (20 mg) before colonoscopy. The successful rate of colonoscopy, procedure time, degree of abdominal pain, and polyp detection rate were recorded and compared among all groups. Results: The successful rate of colonoscopy in Group B1 (82.0%) and Group B2 (83.0%) was significantly higher than that in Group B0 (62.0%, all P < 0.01). The time to reach the ileocecal region in Group B1 and Group B2 were lower than those in Group B0 (all P < 0.05). However, no significant differences were observed in

  20. Improved localization of glucose-6-phosphate dehydrogenase activity in cells with 5-cyano-2,3-ditolyl-tetrazolium chloride as fluorescent redox dye reveals its cell cycle-dependent regulation.

    PubMed

    Frederiks, Wilma M; van Marle, Jan; van Oven, Carel; Comin-Anduix, Begonya; Cascante, Marta

    2006-01-01

    Since the introduction of cyano-ditolyl-tetrazolium chloride (CTC), a tetrazolium salt that gives rise to a fluorescent formazan after reduction, it has been applied to quantify activity of dehydrogenases in individual cells using flow cytometry. Confocal laser scanning microscopy (CLSM) showed that the fluorescent formazan was exclusively localized at the surface of individual cells and not at intracellular sites of enzyme activity. In the present study, the technique has been optimized to localize activity of glucose-6-phosphate dehydrogenase (G6PD) intracellularly in individual cells. Activity was demonstrated in cultured fibrosarcoma cells in different stages of the cell cycle. Cells were incubated for the detection of G6PD activity using a medium containing 6% (w/v) polyvinyl alcohol, 5 mM CTC, magnesium chloride, sodium azide, the electron carrier methoxyphenazine methosulphate, NADP, and glucose-6-phosphate. Before incubation, cells were permeabilized with 0.025% glutaraldehyde. Fluorescent formazan was localized exclusively in the cytoplasm of fibrosarcoma cells. The amount of fluorescent formazan in cells increased linearly with incubation time when measured with flow cytometry and CLSM. When combining the Hoechst staining for DNA with the CTC method for the demonstration of G6PD activity, flow cytometry showed that G6PD activity of cells in S phase and G2/M phase is 27 +/- 4% and 43 +/- 4% higher, respectively, than that of cells in G1 phase. CLSM revealed that cells in all phases of mitosis as well as during apoptosis contained considerably lower G6PD activity than cells in interphase. It is concluded that posttranslational regulation of G6PD is responsible for this cell cycle-dependent activity.

  1. 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.

  2. Bromate formation in bromide-containing water through the cobalt-mediated activation of peroxymonosulfate.

    PubMed

    Li, Zhaobing; Chen, Zhi; Xiang, Yingying; Ling, Li; Fang, Jingyun; Shang, Chii; Dionysiou, Dionysios D

    2015-10-15

    Bromate formation in bromide-containing water through the cobalt (Co)-mediated activation of peroxymonosulfate (PMS) was investigated. Increasing the PMS dosage and the cobalt dosage increased the formation of bromate and bromate yields of up to 100% were recorded under the test conditions. The bromate yield increased to a maximum as the pH rose from 2.7 to 6 before decreasing by over 90% as the pH rose further from 6 to above 9. The bromate formation is a two-step process involving free bromine as a key intermediate and bromate as the final product. In the first step, apart from the known oxidation of bromide to free bromine and of free bromine to bromate by sulfate radicals (SO4(-)), Co(III) produced from the oxidation of Co(II) by PMS and SO4(-) also oxidizes bromide to free bromine. The contribution of Co(III) to the bromate formation was verified with the addition of methanol and EDTA, a radical scavenger and a Co(III) ligand, respectively. In the presence of methanol, free bromine formation increased with increasing Co(II) dosage but no bromate was detected, indicating that Co(III) oxidized bromide to form free bromine but not bromate. In the presence of both EDTA and methanol, no free bromine or bromate was detected, as Co(III) was stabilized by EDTA to form the Co(III)EDTA(-) complex, which could not oxidize bromide. Mathematical simulation further suggested that Co(III) outweighed SO4(-) to oxidize bromide to free bromine. On the other hand, SO4(-) is essential for the oxidation of free bromine to bromate in the second step. In real water, the presence of NOM significantly decreased the bromate formation but caused the brominated organic DBP formation with high quantity. This is the first study to demonstrate the significant bromate formation in the Co/PMS system and the substantial contribution of Co(III) to the formation.

  3. Atmospheric volatilization of methyl bromide, 1,3-dichloropropene, and propargyl bromide through two plastic films: transfer coefficient and temperature effect

    NASA Astrophysics Data System (ADS)

    Wang, D.; Yates, S. R.; Gan, J.; Knuteson, J. A.

    Atmospheric emission of methyl bromide (MeBr) and its potential alternative chemicals such as 1,3-dichloropropene (1,3-D) and propargyl bromide (PrBr) can contribute to air pollution and ozone depletion (for MeBr). One of the main sources of these chemicals is from agricultural soil fumigation. To understand the volatilization dynamics, emission of MeBr, 1,3-D, and PrBr through a polyethylene-based high-barrier film (HBF) and a virtually impermeable film (VIF) was measured using an air flow and sampling system that produced >90% mass balance. The experiment was conducted outdoors and was subjected to ambient daily temperature variations. The HBF film was found to be very permeable to 1,3-D and PrBr, but somewhat less permeable to MeBr. The VIF film was very impermeable to 1,3-D, PrBr, or MeBr. Measured volatilization flux, in general, exhibited strong diurnal variations which were controlled by film temperature. Unlike the HBF film, a time lag (˜12 h) was observed between high-temperatures and high-emission flux values for the VIF film. An impermeable film may be used as an effective means of controlling the atmospheric emission of MeBr and its alternative chemicals.

  4. Underpotential deposition of Cu on Pt(001): Interface structure and the influence of adsorbed bromide

    NASA Astrophysics Data System (ADS)

    Lucas, C. A.; Markovic, N. M.; Ross, P. N.

    1998-05-01

    Using in situ x-ray diffraction, we studied the underpotential deposition (UPD) of copper onto a Pt(001) electrode both in pure perchloric acid and in the presence of bromide anions. In pure perchloric acid, the Cu is deposited in pseudomorphic p(1×1) islands. In the presence of bromide anions, the strong Pt-Br interaction significantly broadens the potential range of Cu UPD. We propose that Br remains in the interface region throughout the UPD process, at first in a disordered Cu-Br phase and then, at more negative potential, forming a c(2×2) closed-packed monolayer on top of the completed p(1×1) Cu monolayer. The structures are compared to those found during Cu UPD onto Pt(111), and explained in terms of the metal-halide interactions and the Pt surface atomic geometry.

  5. 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.

  6. 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.

  7. Flow Boiling Heat Transfer to Lithium Bromide Aqueous Solution in Subcooled Region

    NASA Astrophysics Data System (ADS)

    Kaji, Masao; Furukawa, Masahiro; Nishizumi, Takeharu; Ozaki, Shinji; Sekoguchi, Kotohiko

    A theoretical prediction model of the boiling heat transfer coefficient in the subcooled region for water and lithium bromide aqueous solution flowing in a rectangular channel is proposed. In the present heat transfer model, a heat flux is assumed to consist of both the forced convective and the boiling effect components. The forced convective component is evaluated from the empirical correlation of convective heat transfer coefficient for single-phase flow considering the effect of increase of liquid velocity due to net vapor generation. Empirical correlations for determining the heat flux due to the boiling effect and the quality at the onset point of net vapor generation are obtained from the data presented in the first report1). Agreement between the present theoretical prediction and the experimental data is satisfactorily good both for water and lithium bromide aqueous solution.

  8. Effect of Concentration on Evaporation Rate for Lithium Bromide Aqueous Solution in a Falling Film Heater

    NASA Astrophysics Data System (ADS)

    Matsuda, Akira; Ide, Tetsuo

    Experiments on evaporation for lithium bromide aqueous solution (0-55 wt% LiBr) were made in Summary a externally heated wetted-wall column under reduced pressures. The evaporation rates of 5 and 8 wt% LiBr-water solutions were similar to those of water. The evaporation rates, however, owered with further increase of the concentration of LiBr, and at low feed rates the evaporation rates lowered with decrease of the feed rate because the temperature of the falling film rose. On the other hand, at high feed rates the evaporation rates lowered with increase of feed rates because the heat transfer coefficients of the falling film decreased. Therefore, a maximum evaporation rate existed and it was supposed that there is the optimum feed rate. The experimental data agreed with the values that were calculated numerically based on the unidirectional model that lithium bromide didn't move through falling film.

  9. Waveguide Chirped-Pulse Fourier Transform Microwave Spectroscopy of Allyl Bromide

    NASA Astrophysics Data System (ADS)

    McCabe, Morgan N.; Shipman, Steven

    2014-06-01

    The rotational spectrum of allyl bromide was recorded from 8.7 to 26.5 GHz at -20 °C with a waveguide chirped-pulse Fourier transform microwave spectrometer. The rotational spectrum of allyl bromide has been previously studied by Niide and coworkers. However, previous assignments of this spectrum only extended to J = 12 and K_a = 1. Newly acquired data from our spectrometer has allowed us to extend the previous work to higher values of J and K_a, leading to significant improvements in the distortion constants in particular. Comparisons between the spectra and conformational preferences of the allyl halides will also be discussed. Y. Niide, M, Takano,T. Satoh, and Y. Sasada J. Mol. Spectrosc., 63, 108(1976) Niide, Yuzuru, J. Sci. Hiroshima Univ., Ser. A, 48, 1(1984)

  10. Structure, temperature effect and bonding order analysis of hydrated bromide clusters

    NASA Astrophysics Data System (ADS)

    Wen, Hui; Huang, Teng; Liu, Yi-Rong; Jiang, Shuai; Peng, Xiu-Qiu; Miao, Shou-Kui; Wang, Chun-Yu; Hong, Yu; Huang, Wei

    2016-11-01

    Halide ions have been received intense interest in charactering and understanding their implications in atmospheric chemistry since they are related to the ozone destruction in the stratosphere. In the current study, structures, thermodynamic properties, and spectroscopic signatures of hydrated bromide Br-(H2O)n (n = 1-8) clusters are thoroughly studied and compared with available studies, the new global minima were observed for the larger size Br-(H2O)7,8 clusters. The numbers of isomer increase with the increasing water molecules, considering the growing complexity, the isomer populations of each size clusters are provided under a wide temperature range, it was shown that different type of structures possess different temperature dependences. In addition, the bond order of different bond types of hydrated bromide has been systematically investigated for the first time.

  11. Surface tension of aqueous lithium bromide solutions containing 1-octanol as a heat-transfer additive

    SciTech Connect

    Ishida, Kenji; Mori, Y.H.

    1996-11-01

    The surface tension of simulated heat-pump working fluids, aqueous solutions of lithium bromide containing 1-octanol, has been measured, for the first time using a recently developed technique (Ishida et al., Rev. Sci. Instrum. 64, 1,324 (1993)) which is inherently suitable for characterizing the surfactant solution surfaces from the aspects of thermodynamic adsorption equilibrium and adsorption kinetics. The measurement has revealed that even the highest-grade reagents of lithium bromide commercially available are not necessarily free from surfactant impurities. Obtained data on the surface tension vs 1-octanol concentration have been examined on the basis of an equilibrium adsorption model. Through the optimal fitting of the Langmuir-type surface equation of state to the data, they have calculated the surface tension vs surface excess relation and also the variation in surface tension vs 1-octanol concentration relation with the surface area per unit volume of a given solution.

  12. Evaluation of alternatives to methyl bromide in melon crops in Guatemala.

    PubMed

    Díaz-Pérez, M; Camacho-Ferre, F; Diánez-Martínez, F; De Cara-García, M; Tello-Marquina, J C

    2009-02-01

    The monoculture of melon in Guatemala has caused the massive appearance of plants with an analogous syndrome for the well-known disease commonly called melon collapse, or vine decline, causing significant losses in crops. Methyl bromide is commonly used to sterilize soil prior to planting in Guatemala, but it must be phased out by 2015. The objective of this study was to evaluate the technique of grafting melon onto hybrids of Cucurbita (Cucurbita maxima x Cucurbita moschata), as an alternative to using soil disinfectants (such as Metam sodium, 1,3-dichloropropene, and methyl bromide) for the control of collapse. The results suggested that both soil disinfection and grafting were not necessary in these locations, since there were no statistical differences in terms of yields between the treatments and the untreated control. Furthermore, these results demonstrate that decisions to disinfect the soil must be based on the firm identification of the causal agents, in addition to preliminary assessments of yield losses.

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

    PubMed

    Ivey, Chris D; Ingersoll, Chris G

    2016-10-01

    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 of H. azteca in 42-d water-only exposures. Improved performance of H. azteca was observed in reconstituted waters with >0.02 mg Br/L. Environ Toxicol Chem 2016;35:2425-2429. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

  14. Replacing Conventional Carbon Nucleophiles with Electrophiles: Nickel-Catalyzed Reductive Alkylation of Aryl Bromides and Chlorides

    PubMed Central

    2012-01-01

    A general method is presented for the synthesis of alkylated arenes by the chemoselective combination of two electrophilic carbons. Under the optimized conditions, a variety of aryl and vinyl bromides are reductively coupled with alkyl bromides in high yields. Under similar conditions, activated aryl chlorides can also be coupled with bromoalkanes. The protocols are highly functional-group tolerant (−OH, −NHTs, −OAc, −OTs, −OTf, −COMe, −NHBoc, −NHCbz, −CN, −SO2Me), and the reactions are assembled on the benchtop with no special precautions to exclude air or moisture. The reaction displays different chemoselectivity than conventional cross-coupling reactions, such as the Suzuki–Miyaura, Stille, and Hiyama–Denmark reactions. Substrates bearing both an electrophilic and nucleophilic carbon result in selective coupling at the electrophilic carbon (R–X) and no reaction at the nucleophilic carbon (R–[M]) for organoboron (−Bpin), organotin (−SnMe3), and organosilicon (−SiMe2OH) containing organic halides (X–R–[M]). A Hammett study showed a linear correlation of σ and σ(−) parameters with the relative rate of reaction of substituted aryl bromides with bromoalkanes. The small ρ values for these correlations (1.2–1.7) indicate that oxidative addition of the bromoarene is not the turnover-frequency determining step. The rate of reaction has a positive dependence on the concentration of alkyl bromide and catalyst, no dependence upon the amount of zinc (reducing agent), and an inverse dependence upon aryl halide concentration. These results and studies with an organic reductant (TDAE) argue against the intermediacy of organozinc reagents. PMID:22463689

  15. Effect of lignocaine, sodium cromoglycate, and ipratropium bromide in exercise-induced asthma

    PubMed Central

    Tullett, WM; Patel, KR; Berkin, KE; Kerr, JW

    1982-01-01

    Eight patients with exercise-induced asthma participated in a single-blind trial comparing the protective effects of inhaled lignocaine (estimated dose 48 mg), sodium cromoglycate (estimated dose 12 mg), and ipratropium bromide (estimated dose 120 μg). Saline was used as control. Effects were assessed from the mean maximal percentage fall in forced expiratory volume in one second (FEV1) and maximal mid-expiratory flow rates (MMFR) after they had run on a treadmill for eight minutes. There was no significant change in baseline FEV1 or MMFR before each agent was given. Saline, lignocaine, and sodium cromoglycate did not alter the mean baseline FEV1 or MMFR significantly. Ipratropium caused bronchodilatation with an increase of 16·3% in the mean FEV1 (p<0·001) and of 43·4% in the mean MMFR (p<0·05). After exercise the maximal percentage falls in FEV1 (means and SEM) after saline, lignocaine, sodium cromoglycate, and ipratropium bromide were 38·1% (5·0), 34·5% (6·1), 11·3% (3·7), and 19·3% (7·4) respectively. Similarly, the mean maximal falls in MMFR after saline, lignocaine, sodium cromoglycate, and ipratropium bromide were 54·4% (5·2), 52·9% (7·7), 23·6% (6·6), and 32·1% (10·5) respectively. The inhibitory effects of sodium cromoglycate and ipratropium bromide were significant whereas lignocaine failed to produce an effect. These results suggest that mediator release is an important factor in exercise-induced asthma and that in some patients the effects of the mediators may be on the postsynaptic muscarinic receptors. Local anaesthesia of sensory vagal receptors, on the other hand, does not prevent exercise asthma and these receptors do not appear to have any important role in exercise-induced bronchoconstriction. PMID:6218645

  16. Ruthenium-catalyzed meta/ortho-selective C-H alkylation of azoarenes using alkyl bromides.

    PubMed

    Li, Gang; Ma, Xingxing; Jia, Chunqi; Han, Qingqing; Wang, Ya; Wang, Junjie; Yu, Liuyang; Yang, Suling

    2017-01-19

    meta/ortho-Selective CAr-H (di)alkylation reactions of azoarenes have been achieved via [Ru(p-cymene)Cl2]2 catalyzed ortho-metalation using various types of alkyl bromides. Particularly, dual meta-alkylation of azoarene and reduction offer an attractive strategy for the synthesis of meta-alkylanilines, which are difficult to access via traditional aniline functionalization methods.

  17. High resolution single strand conformation polymorphism analysis using formamide and ethidium bromide staining.

    PubMed Central

    Xie, T; Ho, S L; Ma, O C

    1997-01-01

    Single strand conformation polymorphism (SSCP) analysis using ethidium bromide can be improved by adding formamide as the denaturant. This gives higher resolution than previous SSCP methods; it had 100% sensitivity in the discrimination of 14 PCR samples from two different genes, even for a long fragment close to the upper limit of 250 base pairs. This modified procedure is a rapid, simple, safe, and yet highly sensitive method for detecting structural differences in DNA fragments. Images PMID:9497922

  18. Synthesis of dimethyl aryl acylsulfonium bromides from aryl methyl ketones in a DMSO-HBr system.

    PubMed

    Cao, Zhiling; Shi, Dahua; Qu, Yingying; Tao, Chuanzhou; Liu, Weiwei; Yao, Guowei

    2013-12-16

    A new, simplified method for the synthesis of dimethyl aryl acylsulfonium salts has been developed. A series of dimethyl aryl acylsulfonium bromides were prepared by the reaction of aryl methyl ketones with hydrobromic acid and dimethylsulfoxide (DMSO). This sulfonium salt confirms that bromine production and the bromination reaction take place in the DMSO-HBr oxidation system. What's more, it is also a key intermediate for the synthesis of arylglyoxals.

  19. Nickel-catalyzed cross-electrophile coupling of 2-chloropyridines with alkyl bromides.

    PubMed

    Everson, Daniel A; Buonomo, Joseph A; Weix, Daniel J

    2014-01-01

    The synthesis of 2-alkylated pyridines by the nickel-catalyzed cross-coupling of two different electrophiles, 2-chloropyridines with alkyl bromides, is described. Compared to our previously published conditions for aryl halides, this method uses the different, more rigid bathophenanthroline ligand and is conducted at high concentration in DMF solvent. The method displays promising functional group compatibility and the conditions are orthogonal to the Stille coupling.

  20. Volatilization Mechanism of 1-Ethyl-3-methylimidazolium Bromide Ionic Liquid (Briefing Charts)

    DTIC Science & Technology

    2012-04-01

    116.1±6.6 kJ/mol and H.‡(CH3CH2Br) = 122.9±7.2 kJ/mol, and the results are found to be in agreement with calculated values for the SN2 reactions ...bromides and alkylimidazoles, presumably through alkyl abstraction via an SN2 type mechanism, and that vaporization of intact ion pairs or the formation

  1. Quartz Crystal Microbalance Studies of Deposition and Dissolution Mechanisms of Electrochromic Films of Diheptylviologen Bromide

    DTIC Science & Technology

    1988-07-07

    to I (3 H*- ~" 2 study monolayer oxide formation on gold electrodes (28a), underpotential deposition of various metals (27b,c), bulk metal deposition ...total delivery of reactant to the surface. Thus, as was recently pointed out by Deakin and Melroy for the case of underpotential deposition (27c), the...Microbalance Studies of Deposition and Dissolution Mechanisms of Electrochromic Films of Diheptylviologen Bromide 12. PERSONAL AUTHOR(S) Gregory S. Ostrom

  2. 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.

  3. Bromidotetra-kis-(2-isopropyl-1H-imidazole-κN)copper(II) bromide.

    PubMed

    Godlewska, Sylwia; Socha, Joanna; Baranowska, Katarzyna; Dołęga, Anna

    2011-10-01

    The Cu(II) atom in the title salt, [CuBr(C(6)H(10)N(2))(4)]Br, is coordinated in a square-pyramidal geometry by four imidazole N atoms and one bromide anion that is located at the apex of the pyramid. The cations and the anions form a two-dimensional network parallel to (001) through N-H⋯Br hydrogen bonds.

  4. 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.

  5. Fast analysis of glycosaminoglycans by microchip electrophoresis with in situ fluorescent detection using ethidium bromide.

    PubMed

    Matsuno, Yu-ki; Kinoshita, Mitsuhiro; Kakehi, Kazuaki

    2005-03-09

    We analyzed some glycosaminoglycans and natural and artificial acidic polysaccharides using microchip electrophoresis in the buffer containing ethidium bromide, and found that they were successfully separated and detected within 150 s with comparable sensitivity with that of conventional electrophoresis using cellulose acetate membrane. We applied the technique to the analysis of glycosaminoglycans in pharmaceutical preparations and also in cultured cancer cells. Rapidness and easy operation of the proposed technique are quite useful for routine analysis of glycosaminoglycans.

  6. 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.

  7. Study on Durability and Stability of an Aqueous Electrolyte Solution for Zinc Bromide Hybrid Flow Batteries

    NASA Astrophysics Data System (ADS)

    Kim, Donghyeon; Jeon, Joonhyeon

    2015-01-01

    Zinc-bromine flow battery using aqueous electrolyte has advantages of cost effective and high energy density, but there still remains a problem improving stability and durability of electrolyte materials during long-time cell operation. This paper focuses on providing a homogeneous aqueous solution for durability and stability of zinc bromide electrolyte. For performance experiments of conventional and proposed electrolyte solutions, detailed cyclic voltammetry (CV) measurements (at a scan rate of 20 mV s-1 in the range of -1.5 V~1.5 V) are carried out for 40 cycles and five kinds of electrolytes containing which has one of additives, such as (conventionally) zinc chloride, potassium chloride, (newly) lithium perchlorate, sodium perchlorate and zeolite-Y are compared with the 2.0 M ZnBr2 electrolyte, respectively. Experimental results show that using the proposed three additives provides higher anodic and cathodic peak current density of electrolytes than using other two conventional additives, and can lead to improved chemical reversibility of zinc bromide electrolyte. Especially, the solution of which the zeolite-Y added, shows enhanced electrochemical stability of zinc bromide electrolyte. Consequently, proposed electrolytes have a significant advantage in comparison with conventional electrolytes on higher stability and durability.

  8. Flight Experiment to Study Double-Diffusive Instabilities in Silver-Doped Lead Bromide Crystals

    NASA Technical Reports Server (NTRS)

    Singh, N. B.; Rosch, W. R.; Suhre, D. R.; Coriell, S. R.; Duval, W. M. B.

    1999-01-01

    A detailed study on the effect of convection on crystal quality was carried out by growing lead bromide crystals in transparent Bridgman furnace. Direct observations were made on the solid-liquid interface and a new kind of instability was observed. This could be explained on the basis of toroidal flow in the AgBr-doped lead bromide sample. With the increasing translation velocity, the interface changed from flat to depressed, and then formed a cavity in the center of the growth tube. The crystal grown at the lowest thermal Rayleigh number showed the highest quality and crystal grown at the largest thermal Rayleigh number showed the worst quality. Numerical studies were carried out to provide a framework for interpreting the observed convective and morphological instabilities, and to determine the critical (limiting) concentration of dopant for a particular growth velocity and gravity level. Theoretical instability diagrams were compared with data obtained from the experimental studies. These studies provided basic data on convective behavior in doped lead bromide crystals grown by the commercially important Bridgman process.

  9. 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.

  10. 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.

  11. Transport of bromide measured by soil coring, suction plates, and lysimeters under transient flow conditions.

    NASA Astrophysics Data System (ADS)

    Kasteel, R.; Pütz, Th.; Vereecken, H.

    2003-04-01

    Lysimeter studies are one step within the registration procedure of pesticides. Flow and transport in these free-draining lysimeters do not reflect the field situation mainly because of the occurence of a zone of local saturation at the lower boundary (seepage face). The objective of this study is to evaluate the impact of flow and transport behaviour of bromide detected with different measuring devices (lysimeters, suction plates, and soil coring) by comparing experimental results with numerical simulations in heterogeneous flow domains. We applied bromide as a small pulse to the bare soil surface (Orthic Luvisol) of the three devices and the displacement of bromide was regurlarly sampled for three years under natural wheather conditions. Based on the mean breakthrough curves we observe experimentally that lysimeters have a lower effective pore-water velocity and exhibit more solute spreading resulting in a larger dispersivity than the suction plates. This can be ascribed to the artefact of the lower boundary. We performed numerical transport simulations in 2-D heterogeneous flow fields (scaling approach) choosing appropriate boundary conditions for the various devices. The simulations allow to follow the temporal evolution of flow and transport processes in the various devices and to gain additional process understanding. We conclude that the model is essentially capable to reproduce the main experimental findings only if we account for the spatial correlation structure of the hydraulic properties, i.e. soil heterogeneity.

  12. The influence of ipratropium bromide and sodium cromoglycate on benzalkonium chloride-induced bronchoconstriction in asthma.

    PubMed Central

    Miszkiel, K A; Beasley, R; Holgate, S T

    1988-01-01

    1. Benzalkonium chloride, an antibacterial preservative that is added to nebuliser solutions, has been shown to cause bronchoconstriction when inhaled by asthmatic subjects. 2. To investigate the potential role of reflex and mast cell-dependent mechanisms in the pathogenesis of bronchoconstriction produced by benzalkonium chloride we examined the effects of ipratropium bromide and sodium cromoglycate on this response in both concentration-response and time-course studies in nine asthmatic subjects. 3. Pretreatment with inhaled ipratropium bromide (1 mg) and sodium cromoglycate (40 mg) displaced the benzalkonium chloride concentration-response curves to the right by a mean 2.2 fold and 3.1 fold respectively. 4. Ipratropium bromide and sodium cromoglycate markedly attenuated the airway response to benzalkonium chloride throughout the 45 min time course period, inhibiting the overall response by 56% and 78% respectively. 5. We conclude that benzalkonium chloride provokes bronchoconstriction in asthmatic subjects through a combination of mast cell activation and stimulation of peripheral and central neural pathways. PMID:2972308

  13. Interaction of ozone and carbon dioxide with polycrystalline potassium bromide and its atmospheric implication

    NASA Astrophysics Data System (ADS)

    Levanov, Alexander V.; Isaikina, Oksana Ya.; Maksimov, Ivan B.; Lunin, Valerii V.

    2017-03-01

    It has been discovered for the first time that gaseous ozone in the presence of carbon dioxide and water vapor interacts with crystalline potassium bromide giving gaseous Br2 and solid salts KHCO3 and KBrO3. Molecular bromine and hydrocarbonate ion are the products of one and the same reaction described by the stoichiometric equation 2KBr(cr.) + O3(gas) + 2CO2(gas) + H2O(gas) → 2KHCO3(cr.) + Br2(gas) + O2(gas). The dependencies of Br2, KHCO3 and KBrO3 formation rates on the concentrations of O3 and CO2, humidity of initial gas mixture, and temperature have been investigated. A kinetic scheme has been proposed that explains the experimental regularities found in this work on the quantitative level. According to the scheme, the formation of molecular bromine and hydrocarbonate is due to the reaction between hypobromite BrO-, the primary product of bromide oxidation by ozone, with carbon dioxide and water; bromate results from consecutive oxidation of bromide ion by ozone Br- → +O3 , -O2 BrO- → +O3 , -O2 BrO2- → +O3, -O2 BrO3- .

  14. 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)

  15. Enhancement of pool boiling heat transfer to lithium bromide aqueous solution

    NASA Astrophysics Data System (ADS)

    Kaji, Masuo; Furukawa, Masahiro; Suyama, Takayuki; Sekoguchi, Kotohiko

    1995-04-01

    An experimental study on enhancement of nucleate pool boiling heat transfer by placing a sponge metal, which had a three-dimensional mesh structure like sponge, close to a plain smooth heat transfer surface was conducted to improve the heat transfer performance of the high temperature generator of absorption chiller/heaters. Boiling curves of water and lithium bromide aqueous solution of mass concentration of 55 to 58% at the atmospheric pressure were presented. Heat transfer characteristics were improved by two to three times both for water and lithium bromide aqueous solution when the sponge metal was attached with an appropriate clearance. Three kinds of sponge metals were tested for lithium bromide aqueous solution under a reduced pressure (24 kPa). The sponge metal #6, which had the finest mesh among the three sponge metals, brought about excellent results at lower heat fluxes, but it caused deterioration of heat transfer at higher heat fluxes. For the wide range of heat flux (5 x 10(exp 4) approximately 2 x 10(exp 5) W/m(exp 2), it was found that the sponge metal #4 with the middle fineness was the most suitable and the optimal clearance was in the range of 0.1 approximately 0.5 mm. The employment of sponge metals for enhancing boiling heat transfer is practically excellent, since no special manufacturing is required to mount them on the heated surface.

  16. Enhancement of Pool Boiling Heat Transfer to Lithium Bromide Aqueous Solution

    NASA Astrophysics Data System (ADS)

    Furukawa, Masahiro; Kaji, Masuo; Suyama, Takayuki; Sekoguchi, Kotohiko

    An experimental study on enhancement of nucleate pool boiling heat tranfer by placing a sponge metal close to a plain heated surface was conducted in order to improve the heat transfer performance of the high temperature generator of absorption chiller/heater. The sponge metal has three dimensional porous mesh framework like sponge. Boiling curves of water under the atmospheric pressure were compared with those of lithium bromide aqueous solution of mass concentration 55 to 58%. Heat transfer characteristics were improved by 2 to3 times both for water and lithium bromide aqueous solution when the sponge metal was placed on the heated surface with and without cleareance. Three kinds of sponge metals were used for lithium bromide aqueous solution under the reduced pressure (24 kPa). At lower heat fluxes,#6 sponge metal which has the finest mesh and the lowest porosity shows excellent results. At high heat fluxes, however,it causes deterioration of heat transfer. Over the wide range of heat fluxes,# 4 sponge metal was found to be most suitable and the optimal clearence was determined as 0.5 mm. The sponge metal is of good practical use as a device to enhance the boiling, since no special manufacturing is required for placing it on the heated surface.

  17. Continuous Inhalation of Ipratropium Bromide for Acute Asthma Refractory to β2-agonist Treatment.

    PubMed

    Koumbourlis, Anastassios C; Mastropietro, Christopher

    2015-01-01

    To present the case of a patient with persistent bronchospasm, refractory to treatment with β2-agonists, that resolved promptly with continuous inhalation of large dose (1000 mcg/hr) ipratropium bromide, and to discuss the possibility of tolerance to β2-agonists as the cause for his failure to respond to adrenergic medications. The patient had received multiple doses of albuterol, as well as subcutaneous terbutaline (0.3 mg), intravenous magnesium sulfate (1 g) and intravenous dexamethasone (10 mg) prior to his admission to the intensive care unit. He remained symptomatic despite systemic intravenous steroids, continuous intravenous terbutaline (up to 0.6 mcg/kg/min), and continuous nebulized albuterol (up to 20 mg/hr for 57 hr) followed by 49 hours of continuous levalbuterol (7 mg/hr). Due to the lack of response, all β2-agonists were discontinued at 106 hours post-admission, and he was started on large dose ipratropium bromide (1000 mcg/hr) by continuous nebulization. Clinical improvement was evident within 1 hour and complete resolution of his symptoms within 4 hours. Continuous inhalation of large dose ipratropium bromide may be an effective regimen for the treatment of patients hospitalized with acute asthma who are deemed to be nonresponsive and/or tolerant to β2-agonist therapy.

  18. 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

    2016-09-06

    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.

  19. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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. ...

  4. Scenario Analysis of the Impact on Drinking Water Intakes from Bromide in the Discharge of Treated Oil and Gas Wastewater

    EPA Pesticide Factsheets

    EPA scientists created different scenarios for conventional commercial wastewater treatment plants that treat oil and gas wastewaters to evaluate the impact from bromide in discharges by the CWTP plants.

  5. Effect of substituents and protonation on photolysis of the 2,5-diphenyl-oxazole molecule

    NASA Astrophysics Data System (ADS)

    Bazyl', O. K.; Artyukhov, V. Ya.; Maier, G. V.; Pomogaev, V. A.

    1997-07-01

    Based on quantum chemical calculations, we consider the effect of substitution by groups with different donor-acceptor properties and protonation on the probability of opening of the oxazole ring of the 2,5-diphenyloxazole molecule (PPO). We show the determining role of the hydrogen-containing medium in this photoconversion. We have established that a substituent introduced into the para position of the 5-phenyl radical, depending on its donor-acceptor properties, can either enhance the efficiency of photolysis (donor substituent) or weaken it (acceptor substituent). We have found the photodissociative states and have determined their multiplicity for the considered substituted PPOs.

  6. Trihalomethane formation by chlorination of ammonium- and bromide-containing groundwater in water supplies of Hanoi, Vietnam.

    PubMed

    Duong, Hong Anh; Berg, Michael; Hoang, Minh Hang; Pham, Hung Viet; Gallard, Hervé; Giger, Walter; von Gunten, Urs

    2003-07-01

    The occurrence and the fate of trihalomethanes (THMs) in the water supply system of Hanoi City, Vietnam was investigated from 1998 to 2001. The chlorination efficiency, THM speciation, and, THM formation potential (THMFP) was determined in the water works and in tap water. With regard to THM formation, three types of groundwater resources were identified: (I) high bromide, (II) low bromide, and (III) high bromide combined with high ammonia and high dissolved organic carbon (DOC) concentrations. Under typical treatment conditions (total chlorine residual 0.5-0.8 mg/L), the total THM formation was always below WHO, EU, and USEPA drinking water standards and decreased in the order type I > type II > type III, although the THMFP was > 400 micrograms/L for type III water. The speciation showed > 80% of bromo-THMs in type I water due to the noticeable high bromide level (< or = 140 micrograms/L). In type II water, the bromo-THMs still accounted for some 40% although the bromide concentration is significantly lower (< or = 30 micrograms/L). In contrast, only traces of bromo-THMs were formed (approximately 5%) in type III water, despite bromide levels were high (< or = 240 micrograms/L). This observation could be explained by competition kinetics of chlorine reacting with ammonia and bromide. Based on chlorine exposure (CT) estimations, it was concluded that the current chlorination practice for type I and II waters is sufficient for > or = 2-log inactivation of Giardia lamblia cysts. However, in type III water the applied chlorine is masked as chloramine with a much lower disinfection efficiency. In addition to high levels of ammonia, type III groundwater is also contaminated by arsenic that is not satisfactory removed during treatment. N-nitrosodimethylamine, a potential carcinogen suspected to be formed during chloramination processes, was below the detection limit of 0.02 microgram/L in type III water.

  7. 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.

  8. Enhanced degradation of the volatile fumigant-nematicides 1,3-d and methyl bromide in soil.

    PubMed

    Ou, L T

    1998-03-01

    The use of the gaseous funaigant-nematicide methyl bromide in agriculture is scheduled to be phased out in the year 2001.1,3-Dichloropropene (1,3-D) in combination with chloropicrin and an herbicide is considered to be a viable alternative to methyl bromide for some crops. 1,3-Dichloropropene consists of two isomers, cis- and trans-l,3-D. A number of soil bacteria have been shown to initially degrade 1,3-D or one of its isomers, cis-l,3-D, via hydrolysis. Until recently, the degradation of cis- and trans-l,3-D in soils was considered to exhibit similar kinetics, witla their degradation rates increasing with increases in soil temperature. Enhanced degradation of 1,3-D in soil from a site in Florida with a history of repeated annual applications of 1,3-D was observed in 1994. Biological hydrolysis was involved in the initial degradation of cis- and trans-l,3-D. The two isomers were degraded at different rates, with the trans isomer being degraded more rapidly than the cis isomer. Cis- and trans-l,3-D in soil from the control site were degraded at a similar rate but more slowly than in the enhanced soil. Methyl bromide in soils can be degraded through chemical hydrolysis and methylation to soil organic matter. Some methanotrophic bacteria and ammonia-oxidation bacteria during the oxidation of their primary substrates (methane and ammonia) also have the capacity to cooxidize methyl bromide to formaldehyde and bromide ion. It was recently observed that degradation of methyl bromide was stimulated in methanotrophic soils and in soils treated with ammonium sulfate. Soil methanotrophic bacteria and soil nitrifiers are apparently responsible for cooxidation of methyl bromide in methanotrophic and ammonia treated soils, respectively.

  9. The structure of adsorbed bromide concurrent with the underpotential deposition (UPD) of Cu on Pt(111)

    NASA Astrophysics Data System (ADS)

    Marković, Nenad M.; Lucas, Chris A.; Gasteiger, Hubert A.; Ross, Philip N.

    1997-02-01

    The adsorption of bromide anions concurrent with the underpotential deposition (UPD) of Cu on Pt(111) was examined utilizing ex-situ LEED and in-situ surface X-ray scattering for structure determination, in combination with coverage determination by rotating ring disk flux measurements with the Pt(111) single crystal as the disk electrode. The results show definitively that Cu UPD on Pt(111) in the presence of bromide is a two-step process, with the total amount of Cu deposited at underpotentials ˜0.95 ± 5% ML (1 ML = 1 adatom per Pt atom). The results also indicate that the surface coverage by adsorbed bromide undergoes only a small (<0.05 ML) change upon the deposition of Cu, even up to a nominal monolayer. We propose a model wherein the first stage of deposition occurs by displacement of the close-packed hexagonal layer of Br adatoms by Cu adatoms through a "turn-over" process, in which Cu is sandwiched between the Pt surface and the Br overlayer, leading to the formation of an ordered Pt(111)CuBr bilayer intermediate phase which closely resembles the (111) planes of the Cu(I)Br crystal. The coverage of both Cu and Br in this intermediate phase is ˜0.5 ML. The second stage is the filling-in of the Cu plane of the bilayer to form a pseudomorphic (1 × 1) Cu monolayer and a disordered Br adlayer with a coverage of ˜0.4 ML. The same mechanism is suggested for Cu UPD on Pt(111) in solutions containing chloride anions.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Measurement and Computation of Movement of Bromide Ions and Carbofuran in Ridged Humic-Sandy Soil

    PubMed Central

    Boesten, Jos J. T. I.

    2009-01-01

    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

  15. A rapid, micro-scale preliminary screening method for active components in Galangal with protective effect against hydrogen peroxide induced cell apoptosis through "thin layer chromatography" and "tetrazolium-based colorimetric assay" array correspondence.

    PubMed

    Cheng, Yuan; Li, Yuanting; Li, Jin; Deng, Yifeng

    2015-05-22

    A new method has been established for rapid preliminary screening active ingredients in natural products through thin layer chromatography (TLC) array responding with tetrazolium-based colorimetric assay (MTT assay) along with post LC-MS in micro-scale. The extract of the natural product was first separated by TLC. The separated spots obtained from TLC were visualized in situ with vanillin-ethanolic sulfuric acid agent to define the array correspondence between TLC spots and 384-cell culture plate for MTT cell viability assay. The TLC spots from the replicate TLC plates were then eluted and transferred into the wells of 384-cell culture plates according to the array respondence. The TLC spots with significant antioxidant activities were further screened by MTT assay, and subsequently traced and identified by LC-MS based on the TLC-MTT assay array correspondence. This new method was successfully applied to screen active ingredients in a Chinese medicine known as Galangal. Two major inhibitors for the decline of PC12 cell survival (Galangin, m/z 269.1, and 5-hydroxy-7-(4'-hydroxy-3'-methoxyphenyl)-1-phenyl-3-heptanone, m/z 327.2) were effectively screened and identified by this method.

  16. Mixed micelles of benzyldimethyltetradecylammonium chloride with tetradecyltrimethylammonium and tetradecyltriphenylphosphonium bromides: a head group contribution.

    PubMed

    Bakshi, Mandeep Singh; Kaur, Ishpinder; Sood, Rohit; Singh, Jasmeet; Singh, Kulbir; Sachar, Shweta; Singh, Kanwar Jit; Kaur, Gurinder

    2004-03-01

    Mixed micelle formation by tetradecyltrimethylammonium (TTAB) and tetradecyltriphenylphosphonium bromides (TTPB) with benzyldimethyltetradecylammonium chloride (BTDACl) was studied with the help of conductivity and Kraft point measurements. The BTDACl + TTAB mixtures showed synergistic interactions whereas those of BTDACl + TTPB indicated weak antagonistic behavior. From Kraft temperature measurements, the enthalpy of fusion (H(1)(0)) from solid hydrated BTDACl to the liquid state in the presence of TTAB or TTPB was computed. It was found that DeltaH(1)(0) was much more positive for BTDACl + TTPB than for BTDACl + TTAB mixtures.

  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.

  18. The effect of ethidium bromide on the liquid crystalline phases of aqueous DNA.

    PubMed

    Gottarelli, G; Spada, G P; Mariani, P; Miranda de Morais, M

    1991-01-01

    The influence of the intercalation of ethidium bromide (EB) on the characteristics of the DNA cholesteric and hexagonal mesophases is studied by optical microscopy, circular dichroism, and X-ray diffraction. The distance between DNA rods in the hexagonal phase is not modified by the presence of EB whereas the pitch of the cholesteric mesophase is considerably shortened by the dye. This seems to be related to the stereochemical effect of the intercalation rather than to the presence of a random distribution of the positive charge of the dye.

  19. 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.

  20. Corrosion inhibition in lithium bromide absorption fluid for advanced and current absorption cycle machines

    SciTech Connect

    Verma, S.K.; Mekhjian, M.S.; Sandor, G.R.; Nakada, N.

    1999-07-01

    This paper presents the results of a novel corrosion inhibitor that exhibits improved protection of carbon steel over the inhibitors currently in practice. This inhibitor, formulated in 65 wt% lithium bromide solution, offers excellent corrosion protection to carbon steel. Corrosion rates were determined using autoclave coupon testing. The corrosion rate in the 300 F to 450 F range was found to be low (1 to 4 mils per year), and the product also showed very low hydrogen generation (0.03 mg/in.{sup 2} of carbon steel per week). The metal was protected with a stable and adherent film.

  1. Thermal and optical studies of some di-methyl-di-alkyl ammonium bromides

    NASA Astrophysics Data System (ADS)

    Witko, Waclaw; Godlewska, Malgorzata; Dynarowicz, Patrycja

    1998-01-01

    Phase situation of homologous series of di-alkyl-di-methyl ammonium bromides represented by the general formula: 2CnN+2C1Br-, with n equals 10, 12, 14, 16, 18, was investigated by means of differential scanning calorimetry and optical microscopy methods in the temperature range 20-180 degrees C. A more complex polymorphism as already reported was detected. All the compounds studied show at least tow anomalies on the DSC curves. The high-temperature phase which appears below the isotropic phase has lancet-like dendritic texture which can be attributed to SmB phase. The enthalpy changes at the transitions were calculated.

  2. 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.

  3. Phase diagram of tetradecyltrimethylammonium bromide (TTAB) + water + octanol system with application of mechanical deformation

    NASA Astrophysics Data System (ADS)

    Yavuz, Aykut Evren; Masalci, Özgür; Kazanci, Nadide

    2014-11-01

    Morphological properties of tetradecyltrimethylammonium bromide (TTAB) + water + octanol system in different concentrations have been studied. In the process, isotropic phase (L1) and nematic calamitic (NC), nematic discotic (ND), hexagonal E and lamellar D anizotropic mesophases have been determined by polarizing microscopy method and partial ternary phase diagram of the system set up. Textural properties of the anisotropic mesophases of the system have been discussed and their birefringence values measured. Mechanical deformation has been applied to the mesophases. The textural properties and the birefringence values have been observed to be changed by the deformation, after and before which changes have been compared.

  4. 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.

  5. Pharmacological mydriasis secondary to ipratropium bromide: a cause of unilateral dilated pupil.

    PubMed

    Sharma, Neil S; Ooi, Ju-Lee; Papalkar, Daya; Sharma, Shanel; Francis, Ian C; Fung, Victor S C

    2008-03-01

    Ipratropium bromide is a commonly used bronchodilator which has been rarely reported to cause pharmacological mydriasis. We report a 22-year-old woman using 6-hourly nebulised ipratropium from a multi-dose preparation, who presented with a unilateral dilated pupil which resolved spontaneously over 24h after discontinuation of her ill-fitting nebuliser mask which had been directing the drug toward that eye. No alternative cause was found despite extensive investigations. Greater recognition of this iatrogenic cause of reversible pupillary dilatation may avoid the need for unnecessary investigations.

  6. The kinetics of monochloramine decomposition in the presence of bromide. Topical report, April 1978-May 1979

    SciTech Connect

    Trofe, T.W.; Johnson, J.D.; Inman, G.W. Jr.

    1980-03-01

    Monochloramine, a major product formed by chlorine added to natural waters, is a problem because of its persistence and fish toxicity. One major route for its decomposition is through its reaction with bromide. The reaction was found to obey a rate law. The principal reaction product is postulated to be a mixed haloamine, NHBrCl, not previously identified. The electric power industry has traditionally used chlorine as an effective biocide in controlling the growth of microbial slimes and biofoulers throughout power plant cooling water systems.

  7. Cetyltrimethyl ammonium bromide-Mg/Al hydrotalcite for removal phenol in water

    NASA Astrophysics Data System (ADS)

    Kurniawati, Puji; Wiyantoko, Bayu; Purbaningtias, Tri Esti; Muzdalifah

    2017-03-01

    Hydrotalcite materials was synthesized by using Cetyltrimethyl Ammonium Bromide (CTAB) and Mg/Al layered double hydroxide with ratio molar 3:1. Synthesis of CTAB-Mg/Al hydrotalcite was carried out using ex situ co-precipitation method at pH 10±0.5. Removal of phenol was optimum at medium pH 6 and it had optimum contact time in 300 min. It followed pseudo second order with adsorption rate constant was 1.15.10-4 mM-1.min-1. The maximum adsorption capacities obtained from the Langmuir model was 35.71 mg.g-1 at room temperature.

  8. Copper bromide vapour laser with an output pulse duration of up to 320 ns

    SciTech Connect

    Gubarev, F A; Fedorov, K V; Evtushenko, G S; Fedorov, V F; Shiyanov, D V

    2016-01-31

    We report the development of a copper bromide vapour laser with an output pulse duration of up to 320 ns. To lengthen the pulse, the discharge current was limited using a compound switch comprising a pulsed hydrogen thyratron and a tacitron. This technique permits limiting the excitation of the working levels at the initial stage of the discharge development to lengthen the inversion lifetime. The longest duration of a laser pulse was reached in tubes 25 and 50 mm in diameter for a pulse repetition rate of 2 – 4 kHz. (lasers and laser beams)

  9. Total lattice potential energy of sodium bromide dihydrate NaBr · 2H 2O

    NASA Astrophysics Data System (ADS)

    Herzig, P.; Jenkins, H. D. B.; Pritchett, M. S. F.

    1984-08-01

    In addition to presenting comparative calculations by two approaches for the total lattice potential energy of sodium bromide dihydrate, NaBr · 2H 2O, found to take the value 803.9 kJ mol -1, we investigate the influence of the size and nature of the basis set used to generate multipole moments in a Hartee-Fock calculation which are in turn used to calculate the Madelung constant. The requirement is one of critical size of the basis set and once this is reached the electrostatic energy will be reliable.

  10. Formation of bromo-substituted triclosan during chlorination by chlorine in the presence of trace levels of bromide.

    PubMed

    Inaba, Kazuho; Doi, Taeko; Isobe, Noriki; Yamamoto, Takashi

    2006-08-01

    The side reactions of triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether, TC) and chlorine in the presence of sodium chloride were investigated. In the absence of sodium chloride, three chloro-derivatives of TC, 2',3,4,4'-tetrachloro-2-hydroxydiphenyl ether (3-Cl-TC), 2',4,4',5-tetrachloro-2-hydroxydiphenyl ether (5-Cl-TC), and 2',3,4,4',5-pentachloro-2-hydroxydiphenyl ether (3,5-Cl(2)-TC) were formed, whereas in the presence of sodium chloride, 3-bromo-2',4,4'-trichloro-2-hydroxydiphenyl ether (3-Br-TC), 5-bromo-2',4,4'-trichloro-2-hydroxydiphenyl ether (5-Br-TC), (3 or 5)-bromo-2',4,4',(5 or 3)-chloro-2-hydroxydiphenyl ether ((3,5)-(BrCl)-TC), and 3,5-dibromo-2',4,4'-trichloro-2-hydroxydiphenyl ether (3,5-Br(2)-TC) were additionally formed. Radiochemical neutron activation analysis indicated that 1g of commercially available sodium chloride contained 73 microg of bromide and the bromide ion was determined to be the source of the side reactions. The rate of decrease of TC due to reaction with chlorine was greatly accelerated by the presence of bromide ion in the system: the rate with only 1 x 10(-5) M bromide ion was three times the rate in the absence of bromide.

  11. p-Bromophenacyl bromide prevents cumene hydroperoxide-induced mitochondrial permeability transition by inhibiting pyridine nucleotide oxidation.

    PubMed

    Zhukova, A; Gogvadze, G; Gogvadze, V

    2004-01-01

    Mitochondrial permeability transition is commonly characterized as a Ca2+ -dependent non-specific increase in inner membrane permeability that results in swelling of mitochondria and their de-energization. In the present study, the effect of different inhibitors of phospholipase A2--p-bromophenacyl bromide, dibucaine, and aristolochic acid--on hydroperoxide-induced permeability transitions in rat liver mitochondria was tested. p-Bromophenacyl bromide completely prevented the hydroperoxide-induced mitochondrial permeability transition while the effects of dibucaine or aristolochic acid were negligible. Organic hydroperoxides added to mitochondria undergo reduction to corresponding alcohols by mitochondrial glutathione peroxidase. This reduction occurs at the expense of GSH which, in turn, can be reduced by glutathione reductase via oxidation of mitochondrial pyridine nucleotides. The latter is considered a prerequisite step for mitochondrial permeability transition. Among all the inhibitors tested, only p-bromophenacyl bromide completely prevented hydroperoxide-induced oxidation of mitochondrial pyridine nucleotides. Interestingly, p-bromophenacyl bromide had no affect on mitochondrial glutathione peroxidase, but reacted with mitochondrial glutathione that prevented pyridine nucleotides from being oxidized. Our data suggest that p-bromophenacyl bromide prevents hydroperoxide-induced deterioration of mitochondria via interaction with glutathione rather than through inhibition of phospholipase A2.

  12. 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.

  13. 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.

  14. Exchange equilibria between bicarbonate, carbonate, chloride and bromide on dowex 1 x 8.

    PubMed

    Lundström, U; Olin, A

    1984-07-01

    The exchange reaction 2R(+)HCO(3)(2-) + CO(3)(2-) right harpoon over left harpoon R(2)(+) CO(3)(2-) + 2HCO(3)(2-) has been studied on Dowex 1 x 8 in the presence of bicarbonate solution in equilibrium with atmospheric carbon dioxide (open system). The experiments showed, as theory predicts, that the composition of the resin phase is independent of the concentration of the bicarbonate solution. The mole fraction of carbonate at equilibrium is about 0.4 and the equilibrium constant is 0.15M at 20 degrees . With this value of the constant, the composition of the ion-exchanger for various bicarbonate concentrations has been calculated for a closed system. At [HCO(3)(-)] < 0.01M a substantial part of the resin is in the carbonate form, whereas for [HCO(3)(-)] 0.05M the resin is present almost exclusively in bicarbonate form. The exchange constants of bromide at trace level have been determined for the bicarbonate and mixed carbonate forms of the ion-exchanger. The exchange constant K(Cl)(HCO(3)) has been determined over the whole composition range and the results can be represented by K(Cl)(HCO(3))= 0.428 -0.063x(Cl) -0.115x(Cl)(2), where X(Cl) is the mole fraction of chloride in the resin. The constants are used to discuss the conditions for the Chromatographie enrichment of bromide from fresh water.

  15. 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

  16. Cesium Enhances Long-Term Stability of Lead Bromide Perovskite-Based Solar Cells.

    PubMed

    Kulbak, Michael; Gupta, Satyajit; Kedem, Nir; Levine, Igal; Bendikov, Tatyana; Hodes, Gary; Cahen, David

    2016-01-07

    Direct comparison between perovskite-structured hybrid organic-inorganic methylammonium lead bromide (MAPbBr3) and all-inorganic cesium lead bromide (CsPbBr3), allows identifying possible fundamental differences in their structural, thermal and electronic characteristics. Both materials possess a similar direct optical band gap, but CsPbBr3 demonstrates a higher thermal stability than MAPbBr3. In order to compare device properties, we fabricated solar cells, with similarly synthesized MAPbBr3 or CsPbBr3, over mesoporous titania scaffolds. Both cell types demonstrated comparable photovoltaic performances under AM1.5 illumination, reaching power conversion efficiencies of ∼6% with a poly aryl amine-based derivative as hole transport material. Further analysis shows that Cs-based devices are as efficient as, and more stable than methylammonium-based ones, after aging (storing the cells for 2 weeks in a dry (relative humidity 15-20%) air atmosphere in the dark) for 2 weeks, under constant illumination (at maximum power), and under electron beam irradiation.

  17. 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

    2015-02-03

    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.

  18. 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.

  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.

  20. 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

  1. 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.

  2. Enhancement of frequency domain indices of heart rate variability by cholinergic stimulation with pyridostigmine bromide.

    PubMed

    Zarei, Ali Asghar; Foroutan, Seyyed Abbas; Foroutan, Seyyed Mohsen; Erfanian Omidvar, Abbas

    2011-01-01

    Pyridostigmine bromide (PB) is a reversible cholinesterase inhibitor. The aim of this study was to determine the effect of orally administration of single dose sustained-released tablet of pyridostigmine bromide (PBSR) on the frequency domain indices of heart rate variability (HRV). Thirty-two healthy young men were participated in this study. They were divided into 2 groups; the pyridostigmine group (n = 22) and the placebo group (n = 10). Electrocardiogram (ECG) was recorded at 10, 30, 60, 90, 120, 150, 180, 210, 240, 300 and 420 min after PBSR administration. At each time, simultaneously, a blood sample was prepared and PB plasma concentration was measured by high-performance liquid chromatography (HPLC) method. Statistical analysis showed that in different indices of HRV, there is a significant increase in low frequency (LF) band at 300 min, but no difference in high frequency band (HF). It also showed significant decreases in normalized high frequency band (Hfnu), normalized low frequency band (Lfnu) and LF/HF ratio at 120, 240 and 300 min after PBSR administration. Maximum plasma concentration of PB was 150 min after the administration. In conclusion, administration of a single dose PBSR can enhance the frequency domains indices of HRV and improvesympathovagal balance.

  3. [Comparative effects of terbutaline sulphate and ipratropium bromide on the respiratory system (author's transl)].

    PubMed

    Villate Navarro, J I; Sobradillo Peña, V; Atxotequi Iaraoligoitia, V; Salaverri Nalda, A; Orive Martínez, C

    1980-04-10

    Bronchodilator action of two pharmacologically different drugs have been compared. Ipratropium bromide (Sch 1000) is a synthetic atropine derivative and terbutaline sulphate is a beta-stimulating agent. Twelve asthmatic patients and eight patients with chronic bronquitis received terbutaline 0.50 mg. and ipratropium 0.04 mg by aerosol inhalation. Both drugs were given at random on a consecutive-day schedule. All patients were clinically stable before treatment (basal FEV/VC less than 60 percent). Total lung capacity (TLC) forced expiratory volume (FEV), SRaw, and V'/V curves before and at 15, 60, 120, and 240 minutes after the produce administration were registered. Presence of side-effects was also checked. An intensive bronchodilator action was observed either after inhalation of ipratropium bromide or terbutaline, but statistical studies showed no significant differences between both drugs in relation to intensity and duration of their actions. Sch 1000 caused similar bronchodilator effects in all cases; a more intense effect in patients with chronic bronchitis could not be noticed. Evaluation of V'/V curve, and especially its relation to a same pulmonary volume, pointed out that both drugs act upon small respiratory airways. Advance side-effects were not present.

  4. 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.

  5. Illness associated with exposure to methyl bromide-fumigated produce--California, 2010.

    PubMed

    2011-07-15

    Methyl bromide (MeBr) is a toxic gas used to fumigate agricultural fields and some produce. The U.S. Department of Agriculture (USDA) requires MeBr fumigation of grapes imported from Chile to prevent invasion by the Chilean false red mite, Brevipalpus chilensis. In 2010, two workers were exposed intermittently to MeBr over several months as part of their job inspecting produce at a cold-storage facility in Carson, California. Both workers had disabling neurologic symptoms (e.g., ataxia, memory difficulties, and dizziness) and elevated serum bromide concentrations. An environmental investigation revealed the potential for MeBr to accumulate in enclosed areas during the transportation and storage of fumigated grapes. Some MeBr air concentrations measured at a single point in time exceeded current 8-hour exposure limits, suggesting that exposure in confined areas could result in poisoning. Possible measures for facilities managers to consider to reduce postfumigation MeBr exposures include 1) increased aeration time, 2) reduction of packaging that might absorb MeBr or limit aeration, and 3) changes in the stacking of pallets to improve air flow. Facilities should monitor air MeBr levels if they store MeBr-fumigated commodities in enclosed spaces entered by workers. Clinicians should consider occupational and environmental exposures in their differential diagnosis, and workers who might become exposed to fumigants should be informed of the health hazards related to these pesticides.

  6. Mild copper-catalyzed vinylation reactions of azoles and phenols with vinyl bromides.

    PubMed

    Taillefer, Marc; Ouali, Armelle; Renard, Brice; Spindler, Jean-Francis

    2006-07-05

    An efficient and straightforward copper-catalyzed method allowing vinylation of N- or O-nucleophiles with di- or trisubstituted vinyl bromides is reported. The procedure is applicable to a broad range of substrates since N-vinylation of mono-, di-, and triazoles as well as O-vinylation of phenol derivatives can be performed with catalytic amounts of copper iodide and inexpensive nitrogen ligands 3 or 8. In the case of more hindered vinyl bromides, the use of the original bidentate chelator 8 was shown to be more efficient to promote the coupling reactions than our key tetradentate ligand 3. The corresponding N-(1-alkenyl)azoles and alkenyl aryl ethers are obtained in high yields and selectivities under very mild temperature conditions (35-110 degrees C for N-vinylation reactions and 50-80 degrees C for O-vinylation reactions). Moreover, to our knowledge, this method is the first example of a copper-catalyzed vinylation of various azoles. Finally, this protocol, practical on a laboratory scale and easily adaptable to an industrial scale, is very competitive compared to the existing methods that allow the synthesis of such compounds.

  7. Chemical vapor transport and solid-state exchange synthesis of new copper selenite bromides

    NASA Astrophysics Data System (ADS)

    Charkin, Dmitri O.; Kayukov, Roman A.; Zagidullin, Karim A.; Siidra, Oleg I.

    2017-02-01

    A new dimorphic copper selenite bromide, Cu5(SeO3)4Br2 was obtained via chemical transport reactions. α-Cu5(SeO3)4Br2, monoclinic (1m) and β-Cu5(SeO3)4Br2, triclinic (1a) polymorphs were produced simultaneously upon reaction of amorphous, partially dehydrated copper selenite and copper bromide. 1m is similar to Cu5(SeO3)4Cl2, whereas 1a is distantly related to Ni5(SeO3)4Br2 and Co5(SeO3)4Br2. Attempts to reproduce synthesis of 1a via exchange reaction between Na2SeO3 and CuBr2 resulted in a new Na2[Cu7O2](SeO3)4Br4 (2). Current study demonstrates for the first time, that both chemical vapor and exchange reactions can be employed in preparation of new selenite halides.

  8. 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.

  9. Determinants of Long-Term Persistence with Tiotropium Bromide for Chronic Obstructive Pulmonary Disease.

    PubMed

    Tanaka, Kyuto; Kamiishi, Nobufumi; Miyata, Jun; Kabata, Hiroki; Masaki, Katsunori; Ogura-Tomomatsu, Hiromi; Tomomatsu, Katsuyoshi; Suzuki, Yusuke; Fukunaga, Koichi; Sayama, Koichi; Betsuyaku, Tomoko; Asano, Koichiro

    2015-06-01

    Tiotropium bromide, a long-acting anticholinergic agent, improves pulmonary function and quality of life of patients suffering from chronic obstructive pulmonary disease (COPD). We retrospectively examined the factors that determine the long-term persistence with tiotropium bromide. Among 6,301 patients who underwent pulmonary function tests in our pulmonary clinic between 2006 and 2009, 644 met the following criteria: 1) age > 40 years, 2) ≥ 20 pack-years smoking history, and 3) forced expiratory volume in 1 sec / forced vital capacity ratio < 0.7. The clinical information, including the prescription of tiotropium, was obtained from the patients' records. Tiotropium was administered to 255 patients (40%), of whom 48 (19%) discontinued treatment within 1 year, and 65 (25%) discontinued treatment within the median observation period of 32 months. The drug was discontinued because of ineffectiveness in 35 patients (73%), and because of adverse drug effects in 13 patients (27%). Young age, current smoking, absence of respiratory symptoms alleviation, and less severe disease characterized by a) mild airflow limitation, b) mild to moderate emphysema, or c) no exacerbation of COPD during the 1(st) year of treatment were predictors of drug discontinuation.

  10. Inhibition of multi-species oral biofilm by bromide doped bioactive glass.

    PubMed

    Galarraga-Vinueza, M E; Passoni, B; Benfatti, C A M; Mesquita-Guimarães, J; Henriques, B; Magini, R S; Fredel, M C; Meerbeek, B V; Teughels, W; Souza, J C M

    2017-03-06

    Bioactive glass is an attractive biomaterial that has shown excellent osteogenic and angiogenic effects for oral bone repairing procedures. However, anti-biofilm potential related to such biomaterial has not been completely validated, mainly against multi-species biofilms involved in early tissue infections. The aim of the present study was to evaluate the anti-biofilm effect of 58S bioactive glass embedding calcium bromide compounds at different concentrations. Bioactive glass containing 0, 5, or 10wt% CaBr2 was synthesized by alkali sol-gel method and then characterized by physco-chemical and scanning electron microscopy (SEM). Then, samples were tested by microbiological assays using optical density, real time q-PCR, and SEM. Bioactive glass particles showed accurate chemical composition and an angular shape with a bimodal size distribution ranging from 0.6 to 110 µm. The mean particle size was around 29 µm. A significant anti-biofilm effect was recorded for 5wt% CaBr2 -doped bioactive glass against S. mitis, V. parvula, P. gingivais, S. gordoni, A. viscosus, F, nucleatum, P. gingivais. F. nucleatum and P. gingivalis. Such species are involved in the biofilm structure related to infections on hard and soft tissues in the oral cavity. The incorporation of calcium bromide into bioactive glass can be a strategy to enhance the anti-biofilm potential of bioactive glasses for bone healing and infection treatment. This article is protected by copyright. All rights reserved.

  11. One- and two-dimensional polymers from proline and calcium bromide.

    PubMed

    Lamberts, Kevin; Şerb, Mihaela-Diana; Englert, Ulli

    2015-04-01

    Reactions of calcium bromide with enantiopure and racemic proline in aqueous solution lead to two solids in which the zwitterionic amino acid acts as a bridging ligand between neighbouring cations. Depending on the chirality of the amino acid, topologically very different products are obtained. With racemic proline, bromide acts as a simple uncoordinated counter-anion for the cationic heterochiral chains in catena-poly[[aquacalcium(II)]-μ-aqua-μ3-DL-proline-μ2-DL-proline], {[Ca(C5H9NO2)2(H2O)2]Br2}n. In agreement with chemical intuition, only carboxylate and aqua O atoms coordinate the alkaline earth cation in a low-symmetry arrangement. In contrast, L-proline affords the two-dimensional network poly[dibromidobis(μ2-L-proline)calcium(II)], [CaBr2(C5H9NO2)2]n, with an unexpected CaBr2 unit in a more regular coordination sphere.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. Tetrazolium compounds: synthesis and applications in medicine.

    PubMed

    Wei, Cheng-Xi; Bian, Ming; Gong, Guo-Hua

    2015-03-27

    Tetrazoles represent a class of five-membered heterocyclic compounds with polynitrogen electron-rich planar structural features. This special structure makes tetrazole derivatives useful drugs, explosives, and other functional materials with a wide range of applications in many fields of medicine, agriculture, material science, etc. Based on our research works on azoles and other references in recent years, this review covers reported work on the synthesis and biological activities of tetrazole derivatives.

  17. [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.

  18. Irradiation as a disinfestation method — update on methyl bromide phase out, regulatory action and emerging opportunities

    NASA Astrophysics Data System (ADS)

    Marcotte, Michelle

    1998-06-01

    Methyl bromide (MeBr), is the most widely used agricultural fumigant in the world for the control of pests and plant diseases. It is used to control pests and diseases in food, agricultural and forestry commodities after harvest, before or during storage or transportation and/or at time of import to control quarantine or storage pests. Knowing MeBr will be phased out has spurred a search for alternative treatments and products, and has placed pressure on regulatory authorities to approve alternatives. Some of methyl bromide use could be replaced with irradiation. Methyl bromide is also used for soil and structural fumigation, and although there is some use of irradiation for packaged soil or greenhouse products, in general, these uses can not be replaced by irradiation. Some radiation processing facilities have either seen increased business to disinfest commodities, or have experienced more inquiries for service. There are many other processes and products competing for this market and irradiation will not win its share of the business without an improved regulatory picture, improved marketing to methyl bromide users and improved information to answer questions from commodity sectors. The United Nations Environment Program — Methyl Bromide Technical Options Committee (MBTOC) provides a venue for the publication or information about the use and availability of irradiation as an alternative to methyl bromide. It provides the technical base to the Montreal Protocol contributing to the setting of phase out dates; this committee is actively researching and assessing all alternatives and needs information about irradiation. The author is a member of the MBTOC committee.

  19. Hydrogen bonding. Part 21. Infrared spectral study of the high-temperature phases of choline bromide and choline iodide

    NASA Astrophysics Data System (ADS)

    Harmon, Kenneth M.; Avci, Günself F.; Thiel, Anne C.

    1986-06-01

    Infrared spectra have been obtained for the high-temperature phase of choline bromide, and for the three high-temperature phases of choline iodide, and the results correlated with our previous studies on choline chloride. All eight known phases of the choline halides contain OH⋯X hydrogen bonds. β-Choline chloride, β-choline bromide, and δ- choline iodide appear to have identical environments; thus, when secondary interionic interactions are overcome by elevated temperatures, a face-centered cubic crystal habit is preferred for all three halides.

  20. 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

  1. Bromidotetra­kis­(2-ethyl-1H-imidazole-κN 3)copper(II) bromide

    PubMed Central

    Godlewska, Sylwia; Kelm, Harald; Krüger, Hans-Jörg; Dołęga, Anna

    2012-01-01

    The CuII ion in the title mol­ecular salt, [CuBr(C5H8N2)4]Br, is coordinated in a square-pyramidal geometry by four N atoms of imidazole ligands and one bromide anion in the apical position. In the crystal, the ions are linked by N—H⋯Br hydrogen bonds involving both the coordinating and the free bromide species as acceptors. A C—H⋯Br inter­action is also observed. Overall, a three-dimensional network results. PMID:23468738

  2. 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

  3. 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.

  4. 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.

  5. COPD patient satisfaction with ipratropium bromide/albuterol delivered via Respimat: a randomized, controlled study

    PubMed Central

    Ferguson, Gary T; Ghafouri, Mo; Dai, Luyan; Dunn, Leonard J

    2013-01-01

    Background Ipratropium bromide/albuterol Respimat inhaler (CVT-R) was developed as an environmentally friendly alternative to ipratropium bromide/albuterol metered-dose inhaler (CVT-MDI), which uses a chlorofluorocarbon propellant. Objective The objective of this study was to evaluate patient satisfaction, device usage, and long-term safety of CVT-R compared to CVT-MDI, and to the simultaneous administration of ipratropium bromide hydrofluoroalkane (HFA; I) and albuterol HFA (A) metered-dose inhalers as dual monotherapies (I + A). Design This is a 48-week, open-label, randomized, active-controlled, parallel-group study (n = 470) comparing CVT-R to CVT-MDI and to I + A. Participants Patients were at least 40 years of age, diagnosed with chronic obstructive pulmonary disease (COPD), and current or exsmokers. Interventions Patients were randomized to receive: (1) CVT-R, one inhalation four times daily (QID); or (2) CVT-MDI, two inhalations QID; or (3) I + A two inhalations of each inhaler QID. Main measures Patient Satisfaction and Preference Questionnaire (PASAPQ) performance score (primary endpoint) and adverse events. Key results PASAPQ performance score was significantly higher (CVT-R versus CVT-MDI, 9.6; and CVT-R versus I + A, 6.2; both P < 0.001) when using CVT-R compared to CVT-MDI or I + A at all visits starting from week 3, while CVT-MDI and I + A treatment groups were similar. Time to first COPD exacerbation was slightly longer in the CVT-R group compared to the other treatment groups, although it did not reach statistical significance (CVT-R versus CVT-MDI, P = 0.57; CVT-R versus I + A, P = 0.22). Rates of withdrawal and patient refusal to continue treatment were lower in CVT-R compared with CVT-MDI and I + A groups (CVT-R versus CVT-MDI, P = 0.09; CVT-R versus I + A, P = 0.005). The percentage of patients reporting adverse events and serious adverse events was similar across all three treatment groups. Conclusion CVT-R is an effective, environmentally

  6. Percutaneous toxicity of anticoagulant warfarin in rats.

    PubMed

    Kataranovski, Milena; Mirkov, Ivana; Vrankovic, Jelena; Kataranovski, Dragan; Subota, Vesna

    2008-01-01

    Percutaneous toxicity of anticoagulant rodenticides is usually manifested by coagulopathy and/or fatal outcome. There are, however, virtually no data on other biological effects of this class of pesticides that gain access into the organism via skin. In this study, percutaneous toxicity of epicutaneously applied warfarin was evaluated by measuring changes in peripheral blood granulocytes in rats. Application of 10 mug (0.05 mg/kg) or 100 mug (0.5 mg/kg) of warfarin (WF) for 3 consecutive days resulted in an increase in prothrombin time, documenting the access of warfarin to systemic circulation. Application of warfarin led to an increase in relative numbers of granulocytes at higher dose, whereas both doses resulted in increased metabolical viability, evaluated by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT) reduction assay. Higher warfarin dose resulted in both granulocyte activation and priming (evaluated by cytochemical nitroblue tetrazolium, NBT, reduction assay of respiratory burst), whereas only a tendency toward activation was noted at lower WF dose. Soluble mediators from the circulation seem responsible for the observed effects, as exogenous plasma from WF-treated animals stimulated NBT reduction by isologous or naïve granulocytes. Data presented in this study are relevant for the recognition of biological effects, other than those affecting hemostasis, of anticoagulant rodenticides that gain access to systemic circulation through the skin.

  7. 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

  8. Hydrogen bonding Part 53. Correlation of differential scanning calorimetric data with IR and dissociation vapor pressure studies of transitions of hexamethonium chloride and bromide dihydrates and hexamethonium bromide monohydrate

    NASA Astrophysics Data System (ADS)

    Snider, Barbara L.; Harmon, Kenneth M.

    1994-03-01

    Differential scanning calorimetry of hexamethonium chloride dihydrate shows an endothermic transition of 2.70 kcal mol -1 at 36.81°C. This correlates well with the temperatures observed by IR spectra (36°C) and equilibrium dissociation vapor pressure studies (37°C) for the transition between Type I planar cluster and Type II extended linear HOH⋯Cl - hydrogen bonding, and with the value of 2.77 kcal mol -1 for this transition derived by Hess' law treatment of dissociation vapor pressure data. Differential scanning calorimetry of hexamethonium bromide shows a rapid endothermic transition of 2.38 kcal mol -1 at 35.15°C and a very slow endothermic transition of about 12-13 kcal mol -1 centered near 50°C. This latter endotherm corresponds to the transition between Type I and Type II HOH⋯Br - hydrogen bonding observed by IR and vapor pressure studies at 49°C. The nature of the 35.15°C endotherm is not known. Hexamethonium bromide also shows a third endotherm at 142.91°C, which presumably results from melting of hydrate in the sealed DSC cell. Combined analysis of differential scanning calorimetry and dissociation vapor pressure data predicts a value of about -13 kcal mol -1 for an exothermic disproportionation at 52°C of two hexamethonium bromide monohydrate to Type II dihydrate and anhydrous bromide.

  9. The role of adsorption of dodecylethyldimethylammonium bromide and benzyldimethyldodecylammonium bromide surfactants in wetting of polytetrafluoroethylene and poly(methyl methacrylate) surfaces

    NASA Astrophysics Data System (ADS)

    Harkot, Joanna; Jańczuk, Bronisław

    2009-01-01

    The role of adsorption of dodecylethyldimethylammonium bromide (C 12(EDMAB)) and benzyldimethyldodecylammonium bromide (BDDAB) at water-air and polytetrafluoroethylene (PTFE)-water and poly(methyl methacrylate) (PMMA)-water interface, in wetting of PTFE and PMMA surface, was established from the measured values of the contact angle ( θ) of aqueous C 12(EDMAB) and BDDAB solutions in PTFE (PMMA)-solution drop-air system, and from the measured values of the surface tension of aqueous C 12(EDMAB) and BDDAB solutions. Adsorption of C 12(EDMAB) and BDDAB at water-air interface was determined earlier from the Gibbs equation. Adsorption at solid-water interface was deduced from the Lucassen-Reynders equation based on the relationship between adhesion tension ( γLV cos θ) and surface tension ( γLV). The slope of the γLV cos θ- γLV curve was found to be constant and equal to -1, and about -0.3 for PTFE and PMMA surface, respectively (in the case of both surfactant studied: C 12(EDMAB) and BDDAB, and in the whole range of surfactants concentration in solution). It means that the amount of the surfactant adsorbed at the PTFE-water interface, ΓSL, was essentially equal to its amount adsorbed at water-air interface, ΓLV. However, ΓSL at the PMMA-water interface was about three times smaller as compared to that at water-air interface. By extrapolating the linear dependence between γLV cos θ- γLV and dependence between cos θ- γLV and cos θ = 1 we determined the value of the critical surface tension of PTFE and PMMA surface wetting, γc. The obtained values of γc for PTFE surface were equal 23.4 and 23.8 mN/m, 23.1 and 23.2 mN/m for C 12(EDMAB) and BDDAB, respectively and they were higher than the surface tension of PTFE (20.24 mN/m). On the other hand, the obtained values of γc for PMMA surface were equal 31.4 and 30.9 mN/m, 31.7 and 31.3 mN/m for C 12(EDMAB) and BDDAB, respectively and they were smaller than the surface tension of PMMA (39.21 mN/m). Using the

  10. Crystal structure of 2-carboxy- N,N,N- trimethylethanaminium bromide monohydrate

    NASA Astrophysics Data System (ADS)

    Chen, Xiao-Ming; Mak, Thomas C. W.

    1991-05-01

    A new betaine derivative, 2-carboxy- N,N,N-trimethylethanaminium bromide monohydrate, (Me 3NCH 2CH 2COOH)Br·H 2O, I, has been synthesized and characterized by X-ray crystallography. Compound I crystallizes in space group Pnma (no. 62), with a=10.452(2), b=6.855(2), c=13.737(2)Å, and Z=4. The structure ( RF=0.047 for 881 observed (⋎ FO⋎&>;6⋎ FO⋎) Mo Kα data) features a hydrogen-bonded (BR -·H 2O) ∞zigzag chain running parallel to the a axis. The quaternary ammonium ions, each attaining Cs molecular symmetry, are laterally attached by donor hydrogen bonds to the exposed water molecules of the zigzag chain. The crystal structure consists of layers each having a zipper-like arrangement of the quaternary ammonium "side-chains".

  11. Recovery of bromine from waste gas-phase hydrogen bromide streams using an electrolytic membrane

    SciTech Connect

    Wauters, C.N; Winnick, J.

    1996-09-01

    An electrochemical cell is used to demonstrate a significant improvement in the recovery of bromine (Br{sub 2}) from waste gas-phase hydrogen bromide (HBr) streams. The continuous process operates at 300 C and utilizes reticulated vitreous carbon gas-diffusion electrodes, a molten (Li{sub 0.575}K{sub 0.133}Cs{sub 0.292})Br electrolyte, and borosilicate glass fiber membrane. HBr is simultaneously electrolytically decomposed and separated into a hydrogen enriched waste stream and pure anhydrous Br{sub 2} product stream. Simulated industrial waste streams containing HBr, nitrogen, water vapor, and organic compounds have been tested. These results include removals of greater than 90% and current densities approaching 1.0 A/cm{sup 2}.

  12. 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.

  13. Micellization of alkyltrimethylammonium bromide surfactants in choline chloride:glycerol deep eutectic solvent.

    PubMed

    Sanchez-Fernandez, Adrian; Arnold, Thomas; Jackson, Andrew J; Fussell, Sian L; Heenan, Richard K; Campbell, Richard A; Edler, Karen J

    2016-12-07

    Deep eutectic solvents have shown the ability to promote the self-assembly of surfactants in solution. However, some differences have been found compared with self-assembly in pure water and other polar organic solvents. The behaviour of alkyltrimethylammonium bromides in choline chloride:glycerol deep eutectic solvent has been studied by means of surface tension, X-ray and neutron reflectivity and small-angle neutron scattering. The surfactants were found to remain surface active and showed comparable critical micelle concentrations to the same surfactants in water. Our scattering studies demonstrate that these surfactants form globular micelles with ellipsoidal shape in solution. The size, shape and aggregation number of the aggregates were found to vary with the chain length of the surfactant. Specific solvent-headgroup interactions were not found in this system, unlike those we have previously postulated for anionic surfactants in choline chloride deep eutectic solvents.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. On-line sample preconcentration by sweeping with dodecyltrimethylammonium bromide in capillary zone electrophoresis

    PubMed Central

    Gong, Maojun; Wehmeyer, Kenneth R.; Limbach, Patrick A.; Heineman, William R.

    2008-01-01

    On-line sample preconcentration of oligonucleotides with a new sweeping carrier was developed by using dodecyltrimethylammonium bromide (DTAB) below the critical micelle concentration (CMC). The sweeping results with DTAB below and above the CMC were compared. The use of DTAB below the CMC benefits the preconcentration of the oligonucleotides, while the use of DTAB above the CMC is good for hydrophobic small molecules. The factors affecting the sweeping results were optimized and this method was evaluated by constructing calibration curves for thrombin aptamers. The sweeping scheme produced a 112-fold sensitivity enhancement for the oligonucleotides relative to that run in a running buffer without DTAB. The sweeping method developed here can be a good reinforcement of the preconcentration scheme by sweeping when less-hydrophobic analytes or large negatively-charged molecules need to be preconcentrated. PMID:16808920

  19. 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

  20. Evaporation for Lithium Bromide Aqueous Solution in a Falling Film Heater under Reduced Pressures

    NASA Astrophysics Data System (ADS)

    Matsuda, Akira; Ide, Tetsuo; Yukino, Keiji

    Experiments on evaporation for water and lithium bromide (LiBr) aqueous solution were made in a externally heated wetted-wall column under reduced pressures. For water, evaporation rate increased slightly as feed rate decreased. The heat transfer coefficients of falling film agreed with those for filmwise condensation. For LiBr solution, evaporation rate decreased and outlet temperature of LiBr solution increased as feed rate decreased. The equations of continuity, diffusion and energy which assume that only water moves to the surface and LiBr doesn't move through falling film of LiBr solution were solved numerically. Calculated values of evaporation rate and outlet temperature of solution agreed with experimental results. The results of this work were compared with pool boiling data reported previously, and it was shown that falling film heater is superior to pool boiling heater concerning heat transfer.

  1. Interaction between dimethyldioctadecylammonium bromide-modified PLGA microspheres and hyaluronic acid

    NASA Astrophysics Data System (ADS)

    Mulia, Kamarza; Devi, Krisanti, Elsa

    2017-02-01

    In application of intravitreal injection, an extended drug delivery system is desired so that the frequency of injection to treat diabetic retinopathy may be reduced. Poly(lactic-co-glycolic acid) polymer (PLGA) was used to encapsulate a model drug in the form of microspheres. The zeta potential of dimethyldioctadecylammonium bromide (DDAB)-modified PLGA microspheres in water was proportional to the DDAB concentration used in the preparation step, up to +57.8 mV. The scanning electron microscope pictures and the zeta potential data (SEM) confirmed that the surface of the PLGA has been modified by the cationic surfactant and that electrostatic interaction between the positively charged microspheres and the negatively charged vitreous were present.

  2. Bromidotetra-kis-(1H-2-ethyl-5-methyl-imidazole-κN)copper(II) bromide.

    PubMed

    Godlewska, Sylwia; Baranowska, Katarzyna; Socha, Joanna; Dołęga, Anna

    2011-12-01

    The Cu(II) ion in the title compound, [CuBr(C(6)H(10)N(2))(4)]Br, is coordinated in a square-based-pyramidal geometry by the N atoms of four imidazole ligands and a bromide anion in the apical site. Both the Cu(II) and Br(-) atoms lie on a crystallographic fourfold axis. In the crystal, the [CuBr(C(6)H(10)N(2))(4)](+) complex cations are linked to the uncoordinated Br(-) anions (site symmetry [Formula: see text]) by N-H⋯Br hydrogen bonds, generating a three-dimensional network. The ethyl group of the imidazole ligand was modelled as disordered over two orientations with occupancies of 0.620 (8) and 0.380 (8).

  3. Successful treatment of migrating partial seizures in Wolf-Hirschhorn syndrome with bromide.

    PubMed

    Itakura, Ayako; Saito, Yoshiaki; Nishimura, Yoko; Okazaki, Tetsuya; Ohno, Koyo; Sejima, Hitoshi; Yamamoto, Toshiyuki; Maegaki, Yoshihiro

    2016-08-01

    A girl with mild psychomotor developmental delay developed right or left hemiclonic convulsion at 10months of age. One month later, clusters of hemiclonic or bilateral tonic seizures with eyelid twitching emerged, resulting in status epilepticus. Treatment with phenobarbital and potassium bromide completely terminated the seizures within 10days. Ictal electroencephalography revealed a migrating focus of rhythmic 3-4Hz waves from the right temporal to right frontal regions and then to the left frontal regions. Genetic analysis was conducted based on the characteristic facial appearance of the patient, which identified a 2.1-Mb terminal deletion on chromosome 4p. This is the first case of Wolf-Hirschhorn syndrome complicated by epilepsy with migrating partial seizures.

  4. Effect of surfactant additive on pool boiling of concentrated lithium bromide solution

    SciTech Connect

    Wu, W.T.; Yang, Y.M.; Maa, J.R.

    1998-11-01

    The measurements of nucleate pool boiling heat transfer rate and surface tension were made for pure water and 50 wt.% lithium bromide solution with various amounts of n-octanol. Regardless of low concentration, n-octanol additive depresses considerably the surface tension of the liquids. The pool boiling data, however, reveal that the addition of surfactant results in insignificant enhancement of heat transfer for both pure water and the concentrated LiBr solution. With the results of this work, the performance improvement received from using n-octanol additive in working liquid of an absorption heat pump (AHP) is consequently due to the enhancement of heat and mass transfer in the absorber (but not generator) by the induced interfacial turbulence.

  5. Cobalt-catalyzed hydroalkylation of [60]fullerene with active alkyl bromides: selective synthesis of monoalkylated fullerenes.

    PubMed

    Lu, Shirong; Jin, Tienan; Bao, Ming; Yamamoto, Yoshinori

    2011-08-17

    The Co-catalyzed hydroalkylation of C(60) with reactive alkyl bromides 1 (RBr) in the presence of Mn reductant and H(2)O at ambient temperature gave the monoalkylated C(60) (2) in good to high yields. The use of CoLn/Mn/H(2)O under Ar atmosphere is crucial for the success of the present transformation. The reaction most probably proceeds through the Co(0 or I) complex-promoted generation of a radical (R(•)) followed by addition to C(60). This hydroalkylation method was applied to the synthesis of zinc porphyrin attached C(60) (2l), dendrimer attached C(60) (2m), and fullerene dimer (2n), which were not easily available through the previously known methods.

  6. Neuromuscular complications in patients given Pavulon (pancuronium bromide) during artificial ventilation.

    PubMed

    Op de Coul, A A; Lambregts, P C; Koeman, J; van Puyenbroek, M J; Ter Laak, H J; Gabreëls-Festen, A A

    1985-01-01

    This paper reports on 12 patients in a 3-year period (from 1st July 1980 to 1st July 1983) who were treated with artificial ventilation and with the muscle relaxant pancuronium bromide (Pavulon), over a period of 6 days or longer. After discontinuation of this drug these patients developed severe tetraparesis with areflexia, sometimes combined with disturbances of the extraocular and facial muscles and diffuse muscular atrophy, without sensory disturbances. Seven patients recovered completely after 2-5 months, two made an incomplete recovery and three died due to the primary disease. It is suggested that these neuromuscular complications were caused by prolonged high-dosage Pavulon treatment in combination with renal and hepatic disturbances and/or the use of aminoglucosides.

  7. 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.

  8. Bilateral acute angle closure developing due to use of ipratropium bromide and salbutamol.

    PubMed

    Kola, Mehmet; Hacıoğlu, Dilek; Erdöl, Hidayet; Türk, Adem

    2017-02-06

    Acute angle closure can be seen as a side effect of some medications that can be used systemically. In this article, clinical characteristics of 54-year-old female patient who applied to our clinic with bilateral acute angle closure and has been received nebulized form of salbutamol and ipratropium bromide due to asthma for 4 days was evaluated. Right and left eye IOP were measured as 50 and 48 mmHg. IOP was reduced with anti-glaucomatous treatment. and peripheral iridectomy was done, and then the patient was discharged. It is necessary to be careful to prevent contact with the eye of nebulized form of these drugs which may result in angle closure glaucoma when used systemically.

  9. Characterization of potassium bromide crystals grown in the aqueous solution of picric acid

    NASA Astrophysics Data System (ADS)

    Maheswari, J. Uma; Krishnan, C.; Kalyanaraman, S.; Selvarajan, P.

    2016-12-01

    Potassium bromide crystals were grown in the aqueous solution of picric acid by slow evaporation technique at room temperature. X-ray Diffraction (XRD) analysis ensures that the grown sample is in Fm3m space group and FCC structure. Energy Dispersive X-ray Spectroscopy (EDX) reveals the presence of elements in the title compound. UV-Vis-NIR spectrum reveals that the grown sample is a promising nonlinear optical (NLO) material. FTIR analysis confirms the functional groups present in the sample. The thermogravimetric (TG) and differential thermogravimetric (DTA) analyses ensure that the sample material is thermally stable up to 160 °C. The second harmonic efficiency of the sample is 1.3 times greater than that of standard KDP. The mechanical strength of the grown sample is estimated by Vickers microhardness tester. The electrical properties were investigated by impedance analysis and the results of various studies of the grown crystals are discussed.

  10. 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.

  11. 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.

  12. 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.

  13. Permanganate-bromide-silver nanoparticles as a new chemiluminescence system and its application to captopril determination.

    PubMed

    Amjadi, Mohammad; Manzoori, Jamshid L; Hassanzadeh, Javad; Sorouraddin, Mohammad H

    2013-10-15

    A novel chemiluminescence (CL) system based on the oxidation of bromide by permanganate in sulfuric acid medium is introduced. The enhancing effect of silver nanoparticles (NPs), synthesized by chemical reduction method, on this reaction was studied. It was demonstrated that spherical silver nanoparticles with average size of 18 nm had a most remarkable catalytic effect on this reaction. CL emission wavelengths and UV-vis spectra were used to characterize the system and propose a possible mechanism. Furthermore, it was found that captopril inhibits the action of NPs and decreases the intensity of CL. Based on this phenomenon, a new CL method was developed for the determination of captopril in the 3.0 × 10(-10) to 1.0 × 10(-7) mol L(-1) concentration range with a detection limit (3s) of 0.12 nmol L(-1). The method was successfully applied to the determination of captopril in pharmaceutical formulations, human urine and serum samples.

  14. The distribution of toluene in intercalation complexes of a vermiculite and alkyl trimethylammonium bromides.

    PubMed

    Williams-Daryn, S; Thomas, R K; Castro, M A; Becerro, A I

    2003-11-15

    Neutron diffraction and isotopic labeling have been used to determine the distribution of toluene sorbed into the interlamellar space of complexes of vermiculite with alkyl trimethylammonium bromide complex of alkyl chain lengths C(12), C(14), and C(16) and in a mixed C(12)/C(16) complex. The toluene remains in a liquid-like form and fills and swells the interlamellar space space up to a point where there remains a small amount of overlap of the alkyl chains of the surfactant. If the complex is between vermiculite and one surfactant only this results in the toluene concentration being reduced in the center of the interlamellar space, with maxima on either side. On the other hand, in a complex of mixed-length surfactants, the toluene distribution reaches its maximum at the center of the interlamellar space.

  15. Determination of hexabromocyclododecane in waste waters with a bromide-selective electrode

    SciTech Connect

    Paama, L.A.; Kokk, K.Y.

    1985-11-01

    This paper presents a method for the determination of microquantities of hexabromocyclodecane (HBCD), an antipyrene for the reduction of the flammability of frothing polystyrene in industrial waste waters. The method is based on the extraction of HBCD from waste waters with chloroform, evaporation of the chloroform from the extracts in a stream of air, mineralization of the dry residues, and determination of the bromide ions with a bromine-selective electrode. One of the simpler approaches is given as based on alkaline hydrolysis with dimethyl formamide or in the presence of metallic cadmium. The dry residues after evaporation of the chloroform were decomposed by boiling in a KOH solution in the presence of metallic zinc.

  16. Fabrication of diisopropylammonium bromide aligned microcrystals with in-plane uniaxial polarization

    NASA Astrophysics Data System (ADS)

    Poddar, Shashi; Lu, Haidong; Song, Jingfeng; Goit, Om; Valloppilly, Shah; Gruverman, Alexei; Ducharme, Stephen

    2016-12-01

    Textured arrays of ferroelectric microcrystals of diisopropylammonium bromide were grown from solution at room temperature onto silicon substrates and studied by means of x-ray diffraction, atomic force microscopy, electron microscopy, and piezoresponse force microscopy. The needle-shaped crystals had dimensions of approximately 50 µm  ×  5 µm in the plane and were approximately 200 nm thick, where the dimensions and arrangement were influenced by growth conditions. The observations suggest an Ostwald ripening mechanism of the microcrystal growth. The crystals had the structure of the ferroelectric phase, where the polarization axis was in-plane and parallel to the long axis of the crystals. The in-plane polarization could be switched at will with a scanning probe tip bias of 15 V and could be arranged in stable domain patterns with both charged and uncharged 180° domain walls.

  17. Copper-Mediated Perfluoroalkylation of Heteroaryl Bromides with (phen)CuRF

    PubMed Central

    2015-01-01

    The attachment of perfluoroalkyl groups onto organic compounds has been a major synthetic goal over the past several decades. Previously, our group reported phenanthroline-ligated perfluoroalkyl copper reagents, (phen)CuRF, which react with aryl iodides and aryl boronates to form the corresponding benzotrifluorides. Herein the perfluoroalkylation of a series of heteroaryl bromides with (phen)CuCF3 and (phen)CuCF2CF3 is reported. The mild reaction conditions allow the process to tolerate many common functional groups. Perfluoroethylation with (phen)CuCF2CF3 occurs in somewhat higher yields than trifluoromethylation with (phen)CuCF3, creating a method to generate fluoroalkyl heteroarenes that are less accessible from trifluoroacetic acid derivatives. PMID:24621138

  18. Reaction of myeloperoxidase compound I with chloride, bromide, iodide, and thiocyanate.

    PubMed

    Furtmüller, P G; Burner, U; Obinger, C

    1998-12-22

    Myeloperoxidase plays a fundamental role in oxidant production by neutrophils. The enzyme uses hydrogen peroxide to oxidize chloride (Cl-), bromide (Br-), iodide (I-), and the pseudohalide thiocyanate (SCN-) to their respective hypohalous acids. This study for the first time presents transient kinetic measurements of the oxidation of these halides and thiocyanate by the myeloperoxidase intermediate compound I, using the sequential mixing stopped-flow technique. At pH 7 and 15 degrees C, the two-electron reduction of compound I to the native enzyme by Cl- has a second-order rate constant of (2.5 +/- 0.3) x 10(4) M(-1) s(-1), whereas reduction of compound I by SCN- has a second-order rate constant of (9.6 +/- 0.5) x 10(6) M(-1) s(-1). Iodide [(7.2 +/- 0.7) x 10(6) M(-1) s(-1)] is shown to be a better electron donor for compound I than Br- [(1.1 +/- 0.1) x 10(6) M(-1) s(-1)]. The pH dependence studies suggest that compound I reduction by (pseudo-)halides is controlled by a residue with a pKa of about 4.6. The protonation of this group is necessary for optimum (pseudo-)halide anion oxidation. These transient kinetic results are underlined by steady-state spectral and kinetic investigations. SCN- is shown to be most effective in shifting the system myeloperoxidase/hydrogen peroxide from the peroxidatic cycle to the halogenation cycle, whereas iodide is shown to be more effective than bromide which in turn is much more effective than chloride. Decreasing pH increases the rate of this transition. Our results show that thiocyanate is an important substrate of myeloperoxidase in most environments and that hypothiocyanate is likely to contribute to leukocyte antimicrobial activity.

  19. 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

  20. Acetylcholine-induced proliferation of fibroblasts and myofibroblasts in vitro is inhibited by tiotropium bromide.

    PubMed

    Pieper, M P; Chaudhary, N I; Park, J E

    2007-05-30

    Acetylcholine (ACh) has been suggested to exert various pathophysiological activities in the airways in addition to vagally-induced bronchoconstriction. This archetypal neurotransmitter and other components of the cholinergic system are expressed in a number of non-neuronal cells in the airways. Non-neuronal ACh released from these cells may affect fibroblasts (Fb) as well as inflammatory cells in lung tissue. Tiotropium bromide is a once-a-day antimuscarinic drug, marketed under the brand name Spiriva, for the treatment of chronic obstructive pulmonary disease (COPD). Besides its proven direct bronchodilatory activity, recent evidence suggests that tiotropium may be able to reduce the frequency of exacerbations and attenuate the decline in lung function, thus improving the course of obstructive airway diseases. The aim of the present study was to investigate the effects of tiotropium on the ACh-induced proliferation of primary human Fb isolated from biopsies of lung fibrosis patients and myofibroblasts (MyFb) derived from these cells. A human lung Fb cell line acted as control. Expression of muscarinic receptor subtypes M1, M2 and M3 was demonstrated by RT-PCR in both cell types. Acetylcholine stimulated proliferation in all cells investigated. Tiotropium concentration-dependently inhibited the ACh-induced proliferation in both the Fb and MyFb with a maximum effect at 30 nM. These results suggest that cholinergic stimuli mediated by muscarinic receptors could contribute to remodeling processes in chronic airway disease. Tiotropium bromide may have a beneficial influence on airway remodeling processes in chronic airway diseases through antiproliferative effects on fibroblasts and myofibroblasts.

  1. 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}.

  2. Role of combined indacaterol and glycopyrronium bromide (QVA149) for the treatment of COPD in Japan

    PubMed Central

    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

  3. A clean start to productive orchards and vineyards: recent research on methyl bromide alternatives for perennial crop nurseries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide (MB) is an important pest management tool in open field perennial crop nurseries in California for control of many soil borne pests including plant parasitic nematodes, pathogens, and weeds. Because MB is being phased out under the provisions of the Montreal Protocol, alternatives are...

  4. 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...

  5. 40 CFR 721.10115 - 1-Hexadecanaminium, N,N-dibutyl-N-(2-hydroxyethyl)-, bromide (1:1).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 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...

  6. 40 CFR 721.10115 - 1-Hexadecanaminium, N,N-dibutyl-N-(2-hydroxyethyl)-, bromide (1:1).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 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...

  7. 40 CFR 721.10115 - 1-Hexadecanaminium, N,N-dibutyl-N-(2-hydroxyethyl)-, bromide (1:1).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 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...

  8. Effect of bromide on the transformation and genotoxicity of octyl-dimethyl-p-aminobenzoic acid during chlorination.

    PubMed

    Chai, Qiwan; Zhang, Shujuan; Wang, Xiaomao; Yang, Hongwei; Xie, Yuefeng F

    2017-02-15

    Octyl-dimethyl-p-aminobenzoic acid (ODPABA), one of the most commonly used organic UV filters, can undergo considerable transformation in water when entering into the disinfection process. The impacts of bromide on degradation kinetics, formation and speciation of transformation products, regulated disinfection by-products (DBPs) as well as genotoxicity changes during ODPABA chlorination were investigated in this study. Results indicated that the reaction of ODPABA with chlorine followed pseudo-first-order and second-order kinetics. Adding bromide noticeably enhanced the degradation rate of ODPABA, but reduced the impact of chlorine dose. Four halogenated transformation products (Cl-ODPABA, Br-ODPABA, Cl-Br-ODPABA and Br2-ODPABA) were detected by LC-MS/MS. Mono-halogenated products were stable during 24-h chlorination, while di-halogenated products constantly increased. The total yields of trihalomethanes (THMs) and haloacetic acids (HAAs) were both low, but predominated by bromine substitution at high levels of bromide. In addition, SOS/umu tests showed that genotoxicity was generated after ODPABA chlorination, which was increased at least 1.5 times in the presence of bromine. Whereas, no significant genotoxicity variation was observed following bromide concentration change.

  9. 78 FR 68021 - Notice of Affirmation of Addition of a Treatment Schedule for Methyl Bromide Fumigation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-13

    ... fumigation of blueberries for Mediterranean fruit fly and South American fruit fly. In a previous notice, we... fruit flies. DATES: Effective Date: Effective on November 13, 2013, we are affirming the addition to the... our determination that a new methyl bromide treatment schedule to mitigate risk from two fruit...

  10. Current Pyridostigmine Bromide and Huperzine A Studies and Future Cholinesterase Screening Using the WRAIR Whole Blood Cholinesterase Assay

    DTIC Science & Technology

    2004-11-15

    with pyridostigmine bromide, its therapeutic advantage being to increase the muscle strength in myasthenia gravis patients by inhibiting...exposure in military and civilian populations and also monitoring therapeutic regimens for neurological diseases e.g., myasthenia gravis or...against the lethal effects of GD nerve agent poisoning. Given the extensive cumulative experience with the use of PB in patients with myasthenia

  11. 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...

  12. 1,2,3,4-Tetrahydro-8-hydroxyquinoline-promoted copper-catalyzed coupling of nitrogen nucleophiles and aryl bromides.

    PubMed

    Wang, Huifeng; Li, Yaming; Sun, Fangfang; Feng, Yang; Jin, Kun; Wang, Xiuna

    2008-11-07

    Based on the dramatic accelerating effect of 2-aminophenol, three ligands derived from 2-aminophenol were developed. Copper-catalyzed coupling reaction of nitrogen-containing nucleophiles with aryl bromides was efficiently carried out under mild conditions using 1,2,3,4-tetrahydro-8-hydroxyquinoline as a novel, simple, and versatile ligand.

  13. (2-Pyridyl)acetone-promoted Cu-catalyzed O-arylation of phenols with aryl iodides, bromides, and chlorides.

    PubMed

    Zhang, Qi; Wang, Deping; Wang, Xianyang; Ding, Ke

    2009-09-18

    Employing (2-pyridyl)acetone as a new supporting ligand, the copper-catalyzed coupling reactions of aryl chlorides, aryl bromides, and aryl iodides with various phenols successfully proceeded in good yields under mild conditions. This reaction displays great functional groups compatibility and excellent reactive selectivity.

  14. Evaluation of the efficacy of the methyl bromide fumigation schedule against Mexican fruit fly (Diptera: Tephritidae) in citrus fruit

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide fumigation is a major phytosanitary treatment for a wide variety of quarantine pests, including tephritid fruit flies. Mexican fruit fly, Anastrepha ludens (Loew), is a quarantine pest of a number of fruits, including citrus exported from Texas, Mexico and Central American countries....

  15. 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...

  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

    ... Treatment Schedule for Methyl Bromide Fumigation of Cottonseed AGENCY: Animal and Plant Health Inspection... to immediately add to the Plant Protection and Quarantine Treatment Manual a treatment schedule for...: Effective on March 6, 2013, we are affirming the addition to the Plant Protection and Quarantine...

  17. Indium-mediated one-pot three-component reaction of aromatic amines, enol ethers, and allylic bromides.

    PubMed

    Jang, Taeg-Su; Ku, Il Whea; Jang, Min Seok; Keum, Gyochang; Kang, Soon Bang; Chung, Bong Young; Kim, Youseung

    2006-01-19

    [reaction: see text] A new and efficient indium-mediated one-pot three-component reaction for the synthesis of N-aryl-substituted homoallylamines from aromatic amines, enol ethers, and allylic bromides in THF at room temperature is described.

  18. Alternative fumigants to methyl bromide for killing pupae and preventing emergence of apple maggot fly (Diptera:Tephritidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effects of methyl bromide, ECO2FUME (phosphine gas + CO2), Vapam (sodium methyldithiocarbamate), chloropicrin, Telone II (1, 3 dichloropropene), and chloropicrin + Telone II on killing the pupae and preventing adult emergence of apple maggot fly, Rhagoletis pomonella (Walsh) was determined. In an e...

  19. [In vitro tests for the reduction of high norepinephrine, barbiturate and bromide concentrations in blood by hemofiltration (author's transl)].

    PubMed

    Beer, H; Franken, W; Greuer, W

    1978-01-01

    In vitro tests have shown that a treatment of blood according to the principle of hemofiltration is suitable both for the normalisation of excessive norepinephrine plasma level, e.g. following severe burns, and also for the elimination of toxic quantities of barbiturate and bromide resulting from poisoning by sedatives.

  20. Impact of Long-Term Tiotropium Bromide Therapy on Annual Lung Function Decline in Adult Patients with Cystic Fibrosis

    PubMed Central

    Brandt, Claudia; Thronicke, Anja; Roehmel, Jobst F.; Krannich, Alexander; Staab, Doris; Schwarz, Carsten

    2016-01-01

    Background Chronic lung disease is the leading cause of death in patients with Cystic Fibrosis (CF) and is often treated with bronchodilators. It is not known whether long-term tiotropium bromide treatment may have a positive impact on lung function. Methods This retrospective cohort study estimated annual lung function decline utilizing longitudinal data for forced expiratory volume in 1 s (FEV1). Results A total of 160 adult patients with CF were analyzed. The subjects treated for 24 months with tiotropium bromide had a significantly slower decline of mean annual change of FEV1 (treated: -0.3±4.0%; control: -2.3±5.0%; p = 0.0130). In patients with FEV1 ≥70% predicted, long-term tiotropium bromide treatment was associated with greater improvements in annual lung function decline (FEV1 ≥70% predicted: treated: +0.5±4.7%; control: -4.0±6.3%; p = 0.0132; FEV1 50–69% predicted: treated: -0.5±4.4%; control: -0.8±3.8%; p = 0.7142; FEV1 ≤49% predicted: treated: -0.6±3.4%; control: -2.4±4.8%; p = 0.0898). Conclusion This study suggests that long-term tiotropium bromide treatment may be associated with reduced annual decline of FEV1 in patients with CF, particularly in adults with a mild degree of severity. PMID:27351829