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Sample records for cetyl pyridinium bromide

  1. Flotation de-silicating from diasporic-bauxite with cetyl trimethylammonium bromide

    Institute of Scientific and Technical Information of China (English)

    王毓华; 胡岳华; 刘晓文

    2003-01-01

    Using cetyl trimethylammonium bromide (CTAB) as collector, the flotation de-silicating from diasporicbauxite was investigated. And the Zeta potentials and contact-angles of silicate minerals and diaspore were also stuite and illite become more positive, and the contact angles of these three silicates also increase evidently in the pH range of 2-8, but the Zeta potentials and contact angles of diaspore change little. So, the floatability of the four minerals is in the following order: pyrophyllite>kaolinite≈illite>diaspore. The open-circuit flotation results also show that a bauxite concentrate with m(Al2 O3 )/m(SiO2 ) over 9.3 and Al2 O3 recovery over 76% can be obtained from diasporic-bauxite ore. The result of XRD of the bauxite concentrate shows that pyrophyllite is easier to be removed from diasporic-bauxite than illite and kaolinite due to its better floatability.

  2. Precipitation of silicic acid from geothermal water by addition of cetyl-trimethyl-ammonium bromide

    Energy Technology Data Exchange (ETDEWEB)

    Kitsuki, Harumi; Yokoyama, Takushi; Shimada, Kanichi; Yamanaka, Chiho; Nishu, Keisuke; Shimizu, Shin; Tarutani, Toshikazu

    1986-01-25

    Cetyl-trimethyl-ammonium bromide (CTAB) was added to sodium silicate solution and geothermal hot water (Ohtake Geothermal Power Plant and Hatchobaru Geo-thermal Power Plant) to precipitate silica. 1) CTA ions do not react with monosilicic acid, but only the polymerization among the polysilicic acids proceeds and causes silica to precipitate. Optimum pH for the silica precipitation is 6 - 7 and the higher concentration of polysilicic acid will cause more precipitation. 2) When added to geothermal hot water, the silica precipita-tion increases with the increase of CTAB concentration within the range of 10/sup -7/ - 10/sup -4/ mol dm/sup 3/ concentration. Almost all poly-silicic acid precipitated at 10/sup -4/ mol dm/sup 3/ when measured for silica precipitation after 5 minutes. Total concentration of silicic acid was higher in the Hatchobaru geothermal water than that of the Ohtake geothermal water. (10 figs, 14 refs)

  3. Self-assembly Of cetyl trimethylammonium bromide in ethanol-water mixtures

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Zhang Ming; Zhang Jinli; Han Yongcai

    2006-01-01

    The critical micelle concentration (CMC) of cetyl trimethylammonium bromide (CTAB) in both water and ethanol-water-mixed solvent was determined using steady- state fluorescence techniques in order to investigate the effect of the self-assembling properties of the surfactant on the template synthesis of porous inorganic materials.Results indicated that the CMC increased with the increase of ethanol concentration in the mixed solvent.The CMC of CTAB is 0.0009 mol/L in water,while it is 0.24 mol/L in ethanol.Furthermore,the dissipative particle dynamics (DPD) was adopted to simulate the aggregation of CTAB in water and ethanol/water mixtures,and the energy difference was calculated for the surfactant tail groups after mixing with the solvent.The simulation results reflected a regularity similar to the experimental data,i.e.,tail groups of CTAB interacted more strongly with ethanol than with water,which elucidates the reason that the micelle is difficult to form in ethanol.

  4. Investigating Two-Photon-Induced Fluorescence in Rhodamine-6G in Presence of Cetyl-Trimethyl-Ammonium-Bromide.

    Science.gov (United States)

    Maurya, Sandeep Kumar; Yadav, Dheerendra; Goswami, Debabrata

    2016-09-01

    We investigate the effect of cetyl-trimethyl-ammonium-bromides (CTAB) concentration on the fluorescence of Rhodamine-6G in water. This spectroscopic study of Rhodamine-6G in presence of CTAB was performed using two-photon-induced-fluorescence at 780 nm wavelength using high repetition rate femtosecond laser pulses. We report an increment of ∼10 % in the fluorescence in accordance with ∼12 % enhancement in the absorption intensity of the dye molecule around the critical micellar concentration. We discuss the possible mechanism for the enhancement in the two-photon fluorescence intensity and the importance of critical micellar concentration. PMID:27324955

  5. Small angle neutron scattering studies of mixed micelles of sodium cumene sulphonate with cetyl trimethylammonium bromide and sodium dodecyl sulphate

    Indian Academy of Sciences (India)

    K V Padalkar; V G Gaikar; V K Aswal

    2008-11-01

    The aqueous solutions of sodium cumene sulphonate (NaCS) and its mixtures with each of cetyl trimethylammonium bromide (CTAB) and sodium dodecyl sulphate (SDS) are characterized by small angle neutron scattering (SANS). NaCS when added to CTAB solution leads to the formation of long rod-shaped micelles with a dramatic increase in the CTAB aggregation number. Its addition to SDS on the other hand results in the formation of smaller mixed micelles where part of SDS molecules in the micelle is replaced by NaCS molecules.

  6. Sorption and transport studies of cetyl trimethylammonium bromide (CTAB)and Triton X-100 in clayey soil

    Institute of Scientific and Technical Information of China (English)

    Sivaram Harendra; Cumaraswamy Vipulanandan

    2013-01-01

    Surfactants are soil washing agents and facilitators for subsurface remediation of hydrocarbon spills.It is important to understand the sorption and transport behavior of surfactants for enhanced soil remediation.The adsorption and desorption isotherms of cetyl trimethylammonium bromide (CTAB) and Triton X-100 with sand and kaolinite have been quantified.Kaolinite clay had the highest sorption capacity compared to blasting sand.Transport parameters such as diffusion coefficient (D) and retardation factor (R) of the above mentioned surfactant solutions were determined in clayey soils (82.5% sand and 17.5% kaolinite mixture) with near zero and 0.1 g/L ionic strength.NaCl was used as the electrolyte solution.Convection-Diffusion equation was used to model the breakthrough curves of the surfactants.Bromide ion was chosen as the tracer material in order to characterize the column.CTAB and Triton X-100 were used to flush the perchloroethylene (PCE) contaminated soil.The effectiveness of CTAB and Triton X-100 in flushing the PCE from the contaminated soil was quantified.

  7. Effect of cetyl trimethyl ammonium bromide concentration on structure, morphology and carbon dioxide adsorption capacity of calcium hydroxide based sorbents

    Science.gov (United States)

    Hlaing, Nwe Ni; Vignesh, K.; Sreekantan, Srimala; Pung, Swee-Yong; Hinode, Hirofumi; Kurniawan, Winarto; Othman, Radzali; Thant, Aye Aye; Mohamed, Abdul Rahman; Salim, Chris

    2016-02-01

    Calcium hydroxide (Ca(OH)2) has been proposed as an important material for industrial, architectural, and environmental applications. In this study, calcium acetate was used as a precursor and cetyl trimethyl ammonium bromide (CTAB) was used as a surfactant to synthesize Ca(OH)2 based adsorbents for carbon dioxide (CO2) capture. The effect of CTAB concentration (0.2-0.8 M) on the structure, morphology and CO2 adsorption performance of Ca(OH)2 was studied in detail. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), BET surfaced area and thermogravimetry-differential thermal analysis (TG-DTA) techniques. The phase purity, crystallite size, Brunauer-Emmett-Teller (BET) surface area and CO2 adsorption performance of Ca(OH)2 precursor adsorbents were significantly increased when the concentration of CTAB was increased. XRD results showed that pure Ca(OH)2 phase was obtained at the CTAB concentration of 0.8 M. TGA results exhibited that 0.8 M of CTAB-assisted Ca(OH)2 precursor adsorbent possessed a residual carbonation conversion of ∼56% after 10 cycles.

  8. Carboxymethylcellulose acetate butyrate/poly(4-vinyl-N-pentyl pyridinium bromide blends as antimicrobial coatings

    Directory of Open Access Journals (Sweden)

    L. S. Blachechen

    2015-09-01

    Full Text Available Blends of carboxymethyl cellulose acetate butyrate (CMCAB, a cellulose derivative, and poly(4-vinyl-N-pentyl pyridinium bromide (QPVP-C5, an antimicrobial polymer, were prepared by casting method and characterized by means of Fourier transform infrared vibrational spectroscopy (FTIR, scanning electron microscopy (SEM, thermogravimetric analysis (TGA, differential scanning calorimetry (DSC and contact angle measurements. Miscibility between CMCAB and QPVP-C5 was evidenced by DSC measurements of blends, which showed a single thermal event of Tg, and SEM images, which revealed homogenous morphology, regardless the blend composition. Moreover, thermal stability of QPVP-C5 was substantially enhanced, when it was mixed with CMCAB. Upon increasing the QPVP-C5 content in the blend the wettability and antimicrobial activity against Gram-positive bacteria Micrococcus luteus increased, indicating the surface enrichment by pyridinium groups. In fact, blends with 70 wt% QPVP-C5 reduced 5 log and 4 log the colony-forming units of Micrococcus luteus and Escherichia coli, respectively.

  9. Complete dechlorination of 2,4-dichlorophenol in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel composite electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhirong, E-mail: zrsun@bjut.edu.cn [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Wei, Xuefeng; Han, Yanbo; Tong, Shan [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Hu, Xiang, E-mail: huxiang99@163.com [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2013-01-15

    Highlights: ► Pd/PPy-CTAB/foam-Ni electrode with high surface area and low Pd content was prepared. ► The composite electrode was applied to dechlorination of 2,4-DCP in aqueous solution. ► Complete dechlorination of 2,4-DCP was achieved with higher current efficiency. ► Removal efficiency kept 100% after 10 times dechlorination on the stable electrode. ► The electrochemically reductive activation energy was 25.8 kJ mol{sup −1} in this system. -- Abstract: The electrochemically reductive dechlorination of 2,4-dichlorophenol (2,4-DCP) in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel electrode (Pd/PPy-CTAB/foam-Ni electrode) was investigated in this paper. Pd/PPy-CTAB/foam-Ni electrode was prepared and characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The influences of some experimental factors such as the dechlorination current, dechlorination time and the initial pH on the removal efficiency and the current efficiency of 2,4-DCP dechlorination on Pd/PPy-CTAB/foam-Ni electrode were studied. Complete removal of 2,4-DCP was achieved and the current efficiency of 47.4% could be obtained under the conditions of the initial pH of 2.2, the dechlorination current of 5 mA and the dechlorination time of 50 min when the initial 2,4-DCP concentration was 100 mg L{sup −1}. The analysis of high performance liquid chromatography (HPLC) identified that the intermediate products were 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP). The final products were mainly phenol. Its further reduction product cyclohexanone was also detected. The electrocatalytic dechlorination pathways of 2,4-DCP on Pd/PPy-CTAB/foam-Ni electrode were discussed. The stability of the electrode was favorable that it could keep dechlorination efficiency at 100% after having been reused

  10. Molecular interactions of 1,2-dihydroxyethyl-3,4-dihydroxyfuran-2-one in aqueous N-cetyl-N,N,N-trimethyl ammonium bromide solutions with reference to manifestation of solvation

    International Nuclear Information System (INIS)

    Highlights: ► φv0 values for ascorbic acid indicate the presence of strong solute–solvent interactions. ► B-coefficient values for ascorbic acid also indicate the presence of strong solute–solvent interactions. ► These interactions are further strengthened at higher temperatures and higher concentrations of cetrimonium bromide in ternary solutions. ► This study also reveals that ascorbic acid acts as a structure breaker in the solvent mixtures studied. - Abstract: Apparent molar volumes (φv) and viscosity B-coefficients for 1,2-dihydroxyethyl-3,4-dihydroxyfuran-2-one (ascorbic acid) in (0.001, 0.003, and 0.005) mol · dm−3 aqueous cetrimonium bromide (N-cetyl-N,N,N-trimethyl ammonium bromide) (C19H42BrN) solutions have been determined from solution density, ρ, and viscosity, η, measurements at T = (298.15, 308.15, and 318.15) K as a function of the concentration of ascorbic acid. Within the investigated temperature range, the relation: φv0=a0+a1T+a2T2 , hase been used to describe the partial molar volume φv0. These results, in conjunction with the results obtained in pure water, have been used to calculate the standard volumes of transfer Δφv0 and viscosity B-coefficients of transfer for ascorbic acid from water to aqueous cetrimonium bromide solutions for rationalizing various interactions in the ternary solutions. The structure making or breaking ability of ascorbic acid has been discussed in terms of the sign of (∂2φv0/∂T2)P. An increase in the transfer volume of ascorbic acid with increasing cetrimonium bromide concentration has been explained by the Friedman–Krishnan co-sphere model. The activation parameters of viscous flow for the ternary solutions studied have also been calculated and explained by the application of transition state theory. The 3-D representation of the investigated molecules concerned with this paper is shown below for a better understanding.▪

  11. Effect of Cetyl trimethylammonium bromide (CTAB) amount on phase constituents and magnetic properties of nano-sized NiFe{sub 2}O{sub 4} powders synthesized by sol–gel auto-combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Alamolhoda, S., E-mail: alamolhoda@iust.ac.ir; Mirkazemi, S.M.; Shahjooyi, T.; Benvidi, N.

    2015-07-25

    Highlights: • NiFe{sub 2}O{sub 4} was synthesized by sol–gel auto combustion with different CTAB contents. • CTAB addition affects phase constituents and refines the microstructure. • By 3 wt.% of CTAB addition M{sub max} of the synthesized powder reached to 51 emu/g. - Abstract: In this research nano-sized NiFe{sub 2}O{sub 4} powders were synthesized with and without Cetyl trimethylammonium bromide (CTAB) surfactant addition by sol–gel auto-combustion method. Phase constituents, microstructure and magnetic properties as a result of different CTAB addition amounts were evaluated by X-ray diffraction (XRD), Raman spectroscopy, field emission scanning electron microscope (FESEM) and vibration sample magnetometer (VSM) techniques. XRD results designated that the combustion product consists of NiFe{sub 2}O{sub 4} as the main phase and some amount of α-Fe{sub 2}O{sub 3} and FeNi{sub 3} phases. Raman spectroscopy represents the formation of NiO phase in addition to the mentioned phases. CTAB addition affects the phase constituents and elimination of α-Fe{sub 2}O{sub 3} residuals from the combustion product while facilitating the formation of FeNi{sub 3} phase. Also its addition leads to powder refinement based on FESEM images. Mean crystallite sizes of the samples by calculated by Scherrer equation showed a decreasing trend from 46 to 27 nm with increasing the amount of CTAB. Magnetic measurements showed that saturation magnetization increased from 36.96 emu/g to 51.07 emu/g by CTAB addition as a result of increased FeNi{sub 3} amount. The intrinsic coercivity values ({sub i}H{sub c}) of the samples are in the range of 164–175 Oe.

  12. The Catalytic Activity and Stereoselectivity of Lipase Immobilized in Cetyl Trimethyl Ammonium Bromide/Sorbitan Monostearate Microemulsion-based Gel%十六烷基三甲基溴化铵/山梨醇酐硬脂酸酯微乳液凝胶固定化脂肪酶的催化活性及立体选择性

    Institute of Scientific and Technical Information of China (English)

    王晶; 宋少芳; 路福绥

    2011-01-01

    Cetyl trimethyl ammonium bromide/sorbitan monostearate ( Span-60) microemulsion-based gel (CTAB/Span-60 MBG) having good stability in aqueous solution was successfully prepared. The mass percentage of Span-60 in emulsifier mixture( EM, the mixture of n-butanol and Span-60) was determined. The catalytic activity and stereoselectivity of lipase immobilized in CTAB/Span-60 MBG were tested using the esterification of hexanoic acid and hexanol, the hydrolysis of α-glyceryl monostearate and the stereoselective esterification of racemic ibuprofen and octanol as probes, respectively. The results showed that CTAB/Span-60 MBG with good mechanical strength could be achieved when the mass percentage of Span-60 in EM was less than 57%. In organic solvent, the catalytic esterification activity of lipase in this MBG increased gradually with the increase of the content of Span-60 in EM at the first stage and reached maximum at 35% and then decreased slightly with further increase of the content, and was higher than that in CTAB MBG, within the investigated content of Span-60. This immobilized lipase could catalyze the hydrolysis of α-glyceryl monostearate in aqueous solution and the reaction conversion rate didn't change any more after 24 h. The catalytic hydrolytic activity decreased by 13. 68% after 9 re-usage times. This suggests that lipase in CTAB/ Span-60 MBG could be separated and reused. Lipase in this MBG also selectively catalyzed S-enantiomer ibuprofen to S-enantiomer ester and the excessive enantiomeric product(eee) of the latter gradually decreased with the proceeding of the reaction, but showing better stereoselectivity than CTAB MBG. As a promising carrier for immobilizing lipase, CTAB/Span-60 MBG could be used in biosynthesis and biotransformation not only in organic solvent but also in aqueous solution.%制备了能在水溶液中长时间稳定存在的十六烷基三甲基溴化铵/山梨醇酐硬脂酸酯(CTAB/Span-60)

  13. Synthesis, characterization and comparative evaluation of phenoxy ring containing long chain gemini imidazolium and pyridinium amphiphiles.

    Science.gov (United States)

    Bhadani, Avinash; Kataria, Hardeep; Singh, Sukhprit

    2011-09-01

    Two series of phenoxy ring containing long chain imidazolium and pyridinium based gemini amphiphiles have been synthesized from renewable cardanol oil having different spacers (i. e. -S-(CH(2))(n)-S-, where n is 2, 3, 4 & 6). Critical micelle concentration (cmc) of these new gemini amphiphiles has been determined by conductivity method. Further, these new cationic amphiphiles have been evaluated for their DNA binding capability by agarose gel electrophoresis, ethidium bromide exclusion experiments and transmission electron microscopy (TEM). The cytotoxicity of these new amphiphiles have been evaluated by MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Comparative studies of these phenoxy ring containing long chain gemini imidazolium amphiphiles and their pyridinium analogues depicted low cmc values of the later but greater DNA interaction capability and low cytotoxicity of the former series of amphiphiles. PMID:21676409

  14. Preparation and Peactions of Pyridinium Ylids via Decarboxylation of Pyridinium Betaines

    Institute of Scientific and Technical Information of China (English)

    ShrongShiLIN; JianMeiWANG; 等

    2002-01-01

    Pyridinium ylids 4 were generated as reaction intermediates from the decarboxylation of pyridinium betaines 3, which were prepared from the reactions of α-amino acid ester hydrochlorides with 2,4,6-triphenylpyrylium tetrafluoroborate. Protonation,addition and substitution reactions of 4 with electrophiles were studied in this paper.

  15. Preparation and Reactions of Pyridinium Ylids via Decarboxylation of Pyridinium Betaines

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Pyridinium ylids 4 were generated as reaction intermediates from the decarboxylation of pyridinium bctaincs 3, which were preparcd from the reactions of x-amino acid ester hydrochlorides with 2, 4,6-triphenylpyrylium tetrafluoroborate. Protonation, addition and substitution reactions of 4 with electrophiles werc studied in this paper.

  16. Solvent-free enzymatic production of high quality cetyl esters.

    Science.gov (United States)

    Serrano-Arnaldos, Mar; Máximo-Martín, María Fuensanta; Montiel-Morte, María Claudia; Ortega-Requena, Salvadora; Gómez-Gómez, Elisa; Bastida-Rodríguez, Josefa

    2016-04-01

    A solvent-free biocatalytic process for the synthesis of high quality cetyl laurate, myristate, palmitate and stearate has been optimized. This enzymatic procedure follows the fundamental principles of the Green Chemistry and lead to sustainable products, which can be labeled as natural and conform to the principal requirements for its use in high value-added goods. The four esters selected are the main components of spermaceti, a mixture of waxes very appreciated in cosmetic and pharmacy because of its physical properties and emolliency, which was formerly extracted from the head of the sperm whales. In this paper, the influence of the amount of biocatalyst, the commercially available Novozym(®) 435, and the temperature were studied in an open-air batch reactor before carrying out the synthesis in a high performance vacuum reactor with dry nitrogen input to shift the equilibrium towards product formation. Under optimal conditions, conversion was higher than 98.5 %. The characterization of the enzymatic cetyl esters puts in evidence that these are ultra-pure compounds, which have similar properties to the ones obtained through the conventional industrial processes with the extra benefit of being environmentally friendly. PMID:26801670

  17. Asymmetric Hydrogenation of 3-Substituted Pyridinium Salts.

    Science.gov (United States)

    Renom-Carrasco, Marc; Gajewski, Piotr; Pignataro, Luca; de Vries, Johannes G; Piarulli, Umberto; Gennari, Cesare; Lefort, Laurent

    2016-07-01

    The use of an equivalent amount of an organic base leads to high enantiomeric excess in the asymmetric hydrogenation of N-benzylated 3-substituted pyridinium salts into the corresponding piperidines. Indeed, in the presence of Et3 N, a Rh-JosiPhos catalyst reduced a range of pyridinium salts with ee values up to 90 %. The role of the base was elucidated with a mechanistic study involving the isolation of the various reaction intermediates and isotopic labeling experiments. Additionally, this study provided some evidence for an enantiodetermining step involving a dihydropyridine intermediate. PMID:27140832

  18. Preferred Gauche Conformation in N-(2-Aminoethyl)Pyridinium Ions

    OpenAIRE

    Razenberg, J.A.S.J.; R.J.M. Nolte; Drenth, W.; Kanters, J.A.; Duijneveldt, F.B. van

    1984-01-01

    X-ray analysis of 1-[(2S, 3S)-2-N,N-dibenzylamino-3-methyl-1-pentyl]pyridinium p-toluenesulphonate and 1-[(2S)-2-N,N-dibenzylamino-1-propyl]pyridinium p-toluenesulphonate reveals that in both compounds the central N---C---C---N moiety is in the syn-clinal conformation. According to SCF-LCAO-MO calculations the syn-clinal conformation of the parent on, N-(2-aminomethyl)pyridinium is 23.4 kJ mol−1 lower in energy than the anti-periplanar conformation. The calculations suggest incipient bond for...

  19. CH-directed anion-pi interactions in the crystals of pentafluorobenzyl-substituted ammonium and pyridinium salts.

    Science.gov (United States)

    Albrecht, Markus; Müller, Michael; Mergel, Olga; Rissanen, Kari; Valkonen, Arto

    2010-05-01

    Simple pentafluorobenzyl-substituted ammonium and pyridinium salts with different anions can be easily obtained by treatment of the parent amine or pyridine with the respective pentafluorobenzyl halide. Hexafluorophosphate is introduced as the anion by salt metathesis. In the case of the ammonium salt 4, water co-crystallisation seems to suppress effective anion-pi interactions of bromide with the electron-deficient aromatic system, whereas with salts 5 and 6 such interactions are observed despite the presence of water. However, due to asymmetric hydrogen-bonding interactions with ammonium side chains, the anion of 5 is located close to the rim of the pentafluorophenyl group (eta(1) interaction). In 6 the CH-anion hydrogen bonding is more symmetric and fixes the anion on top of the ring (eta(6)). A similar structure-controlling effect is observed in case of the 1,4-diazabicyclo[2.2.2]octane derivatives 7. Here the position of the anion (Cl, Br, I) is shifted according to the length of the weak CH-halide interaction. The hexafluorophosphate 7 d reveals that this "non-coordinating" anion can be located on top of an aromatic pi system. In the methyl-substituted pyridinium salts 9 and 10 different locations of the bromide anions with respect to the pi system are observed. This is due to different conformations of the mono- versus disubstituted pyridine, which leads to different directions of the weak, but structurally important, H(Me)-Br bonds. PMID:20349467

  20. Preferred gauche conformation in N-(2-aminoethyl)pyridinium ions

    Science.gov (United States)

    Razenberg, Johannes A. S. J.; Nolte, Roeland J. M.; Drenth, Wiendelt; Kanters, Jan A.; Van Duijneveldt, Frans B.

    1984-01-01

    X-ray analysis of 1-[(2 S, 3 S)-2- N,N-dibenzylamino-3-methyl-1-pentyl]pyridinium p-toluenesulphonate and 1-[(2 S)-2- N,N-dibenzylamino-1-propyl]pyridinium p-toluenesulphonate reveals that in both compounds the central NCCN moiety is in the syn-clinal conformation. According to SCF-LCAO-MO calculations the syn-clinal conformation of the parent on, N-(2-aminomethyl)pyridinium is 23.4 kJ mol -1 lower in energy than the anti-periplanar conformation. The calculations suggest incipient bond formation between the amino nitrogen atom and the pyridinium ring in the syn-clinal conformation.

  1. Preferred gauche conformation in N-(2-aminoethyl)pyridinium ions

    NARCIS (Netherlands)

    Duijneveldt, F.B. van; Razenberg, J.A.S.J.; Nolte, R.J.M.; Drenth, W.; Kanters, J.A.

    1984-01-01

    X-ray analysis of 1-[(2S, 3S)-2-N,N-dibenzylamino-3-methyl-1-pentyl]pyridinium p-toluenesulphonate and 1-[(2S)-2-N,N-dibenzylamino-1-propyl]pyridinium p-toluenesulphonate reveals that in both compounds the central N---C---C---N moiety is in the syn-clinal conformation. According to SCF-LCAO-MO calcu

  2. Aggregation behavior and antimicrobial activity of ester-functionalized imidazolium- and pyridinium-based ionic liquids in aqueous solution.

    Science.gov (United States)

    Garcia, M Teresa; Ribosa, Isabel; Perez, Lourdes; Manresa, Angeles; Comelles, Francesc

    2013-02-26

    Two series of long chain imidazolium- and pyridinium-based ionic liquids containing an ester functional group in the alkyl side chain, 3-methyl-1-alkyloxycarbonylmethylimidazolium bromides (C(n)EMeImBr) and 1-alkyloxycarbonylmethylpyridinium bromides (C(n)EPyrBr), were synthesized and their thermal stability, aggregation behavior in aqueous medium, and antimicrobial activity investigated. The introduction of an ester group decreased the thermal stability of the functionalized ILs compared to simple alkyl chain containing ILs (1-alkyl-3-methylimidazolium bromides and 1-alkylpyridinium bromides). Tensiometry, conductimetry, and spectrofluorimetry were applied to study the self-aggregation of the amphiphilic ILs in aqueous solution. The ILs investigated displayed surface activity and the characteristic chain length dependence of the micellization process of surfactants. As compared to simple alkyl chain containing ILs bearing the same hydrocarbon chain, ester-functionalized ILs possess higher adsorption efficiency (pC(20)) and significantly lower critical micelle concentration (cmc) and surface tension at the cmc (γ(cmc)), indicating that the incorporation of an ester group promotes adsorption at the air/water interface and micelle formation. The antimicrobial activity was evaluated against Gram-negative and Gram-positive bacteria and fungi. ILs containing more than eight carbon atoms in the alkyl chain showed antimicrobial activity. Their efficiency as antimicrobial agents increased with the hydrophobicity of the amphiphilic cation being the C(12) homologous the most active compounds. The incorporation of an ester group particularly increased the biological activity against fungi.

  3. Preparation and Comparative Bioavailability Studies of Indomethacin-Loaded Cetyl Alcohol Microspheres

    Directory of Open Access Journals (Sweden)

    N. Vishal Gupta

    2013-01-01

    Full Text Available The purpose of the present study was to compare the in vitro release and to find out whether the bioavailability of a 75 mg indomethacin capsule (Microcid SR was equivalent to optimized formulation (indomethacin-loaded cetyl alcohol microspheres. Indomethacin-loaded cetyl alcohol microspheres were prepared by meltable emulsified cooling-induced technique. Surface morphology of microspheres has been evaluated using scanning electron microscopy. A single dose, randomized, complete cross over study of IM microspheres was carried out on 10 healthy male and female Albino sheep’s under fasting conditions. The plasma was separated and the concentrations of the drug were determined by HPLC-UV method. Plasma indomethacin concentrations and other pharmacokinetic parameters obtained were statistically analyzed. The SEM images revealed the spherical shape of fat microspheres, and more than 98.0% of the isolated microspheres were in the size range 12–32 μm. DSC, FTIR spectroscopy and stability studies indicated that the drug after encapsulation with fat microspheres was stable and compatible. Both formulations were found to be bioequivalent as evidenced by in vivo studies. Based on this study, it can be concluded that cetyl alcohol microspheres and Microcid SR capsule are bioequivalent in terms of the rate and extent of absorption.

  4. 4-Hydroxy-1,2,6-trimethylpyridinium bromide monohydrate

    Directory of Open Access Journals (Sweden)

    T. Seethalakshmi

    2013-06-01

    Full Text Available The title salt, C8H12NO+·Br−·H2O, is isomorphous with the chloride analogue [Seethalakshmi et al. (2013. Acta Cryst. E69, o835–o836]. In the solid state, the cations, anions and water molecules are interlinked by a network of O—H...O, O—H...Br and C—H...Br interactions. The water molecule makes two O—H...Br hydrogen bonds, generating [010] zigzag chains of alternating water molecules and bromide anions. The cation is involved in two intermolecular C—H...Cl interactions in the chloride salt, whereas three intermolecular C—H...Br interactions are observed in the title bromide salt. This additional intermolecular C—H...Br interaction links the adjacent water and bromide zigzag chains via cationic molecules. In addition, weak π–π stacking interactions are observed between pyridinium rings [centroid–centroid distance = 3.5664 (13 Å].

  5. Novel pyridinium surfactants for efficient, nontoxic in vitro gene delivery

    NARCIS (Netherlands)

    van der Woude, I; Wagenaar, A; Meekel, A A; ter Beest, M B; Ruiters, M H; Engberts, J B; Hoekstra, D

    1997-01-01

    Novel, double-chained pyridinium compounds have been developed that display highly efficient DNA transfection properties. The transfection efficiency of several of these compounds is enhanced by an order of magnitude, when compared with the transfection efficiency accomplished with the widely used c

  6. Statement on the safety of 'Cetyl Myristoleate Complex' as an ingredient in food supplements

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA

    2013-06-01

    Full Text Available Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to update its opinion on the safety of ‘Cetyl Myristoleate Complex’ (CMC as a novel food ingredient in the light of a new repeated dose 90-day oral toxicity study in mice. In its previous opinion of 2010, the Panel concluded that based on the available data, the safety of CMC as an ingredient in food supplements has not been established. This conclusion was based on the considerations that in the absence of appropriate data on absorption, distribution, metabolism and excretion, the provided toxicological data were insufficient. Whereas the applicant considers that the NOAEL of CMC in this new 90-day study was 1000 mg/kg body weight (bw, the highest dose tested, the Panel considers that this study and study report has many shortcomings to be a reliable source of information supporting the absence of adverse effects of the parent material CMC. The Panel concludes that the safety of 'Cetyl Myristoleate Complex' has not been established.

  7. The effect of cetylated fatty esters and physical therapy on myofascial pain syndrome of the neck.

    Science.gov (United States)

    Sharan, Deepak; Jacob, Biju Nirmal; Ajeesh, P S; Bookout, Jack B; Barathur, Raj R

    2011-07-01

    Participants with Myofascial Pain Syndrome (MPS) of the neck were randomly assigned into 2 groups of the double-blinded study: topical cetylated fatty ester complex (CFEC) cream application plus physical therapy (CF-PT; n=37), and placebo cream application plus physical therapy (PL-PT; n=35). There were 3 visits during 4 weeks of treatment. Physical Therapy (PT), given twice/week, included Ischaemic Compression, Deep Pressure Trigger Point Massage and Myofascial Releases. Topical cream [CFEC cream (5.6%) and 1.5% menthol] or placebo cream [1.5% menthol, in a cream base] was applied twice/day. CF-PT provided the fastest and most effective study treatment modality. The addition of CFEC cream to PT resulted in statistically significant improvements, compared to PL-PT, for reduction of pain, neck disability and life quality indicators. Our results indicate that cetylated derivatives of fatty acids can effectively reduce pain and symptoms associated with neck MPS, when combined with physical therapy.

  8. Disruption and activation of blood platelets in contact with an antimicrobial composite coating consisting of a pyridinium polymer and AgBr nanoparticles.

    Science.gov (United States)

    Stevens, Kris N; Knetsch, Menno L; Sen, Ayusman; Sambhy, Varun; Koole, Leo H

    2009-09-01

    Composite materials made up from a pyridinium polymer matrix and silver bromide nanoparticles embedded therein feature excellent antimicrobial properties. Most probably, the antimicrobial activity is related to the membrane-disrupting effect of both the polymer matrix and Ag(+) ions; both may work synergistically. One of the most important applications of antimicrobial materials would be their use as surface coatings for percutaneous (skin-penetrating) catheters, such as central venous catheters (CVCs). These are commonly used in critical care, and serious complications due to bacterial infection occur frequently. This study aimed at examining the possible effects of a highly antimicrobial pyridinium polymer/AgBr composite on the blood coagulation system, i.e., (i) on the coagulation cascade, leading to the formation of thrombin and a fibrin cross-linked network, and (ii) on blood platelets. Evidently, pyridinium/AgBr composites could not qualify as coatings for CVCs if they trigger blood coagulation. Using a highly antimicrobial composite of poly(4-vinylpyridine)-co-poly(4-vinyl-N-hexylpyridinium bromide) (NPVP) and AgBr nanoparticles as a thin adherent surface coating on Tygon elastomer tubes, it was found that contacting blood platelets rapidly acquire a highly activated state, after which they become substantially disrupted. This implies that NPVP/AgBr is by no means blood-compatible. This disqualifies the material for use as a CVC coating. This information, combined with earlier findings on the hemolytic effects (i.e., disruption of contacting red blood cells) of similar materials, implies that this class of antimicrobial materials affects not only bacteria but also mammalian cells. This would render them more useful outside the biomedical field.

  9. Action of reactive oxygen species in the antifungal mechanism of gemini-pyridinium salts against yeast.

    Science.gov (United States)

    Shirai, Akihiro; Ueta, Shouko; Maseda, Hideaki; Kourai, Hiroki; Omasa, Takeshi

    2012-06-01

    We previously found that the gemini quaternary salt (gemini-QUAT) containing two pyridinium residues per molecule, 3,3'- (2,7-dioxaoctane) bis (1-decylpyridinium bromide) (3DOBP-4,10) , exerted fungicidal activity against Saccharomyces cerevisiae and caused respiration inhibition and the cytoplasmic leakage of ATP, magnesium, and potassium ions. Here, we investigated how the gemini-QUAT, 3DOBP-4,10, exerts more powerful antimicrobial activity than the mono-QUAT N-cetylpyridinium chloride (CPC) and examined the association between reactive oxygen species (ROS) and the antimicrobial mechanism. Antifungal assays showed that the activity of 3DOBP-4,10 against two yeasts, S. cerevisiae and Candida albicans, was significantly elevated under aerobic conditions, and largely reduced under anaerobic conditions (nitrogen atmosphere) . Adding radical scavengers such as superoxide dismutase, catalase and potassium iodide (KI) also decreased the fungicidal activity of 3DOBP-4,10 but negligibly affected that of CPC. We measured survival under static conditions and found that the rapid fungicidal profile of 3DOBP-4,10 was lost, whereas that of CPC was slightly affected in the presence of KI. Our results suggest that 3DOBP-4,10 exerts powerful antimicrobial activity by penetrating the cell wall and membrane, which then allows oxygen to enter the cells, where it participates in the generation of intracellular ROS. The activity could thus be attributable to a synergic antimicrobial combination of the disruption of organelle membranes by the QUAT and oxidative stress imposed by ROS. PMID:22790843

  10. Investigation of the Pyridinium Ylide—Alkyne Cycloaddition as a Fluorogenic Coupling Reaction

    Directory of Open Access Journals (Sweden)

    Simon Bonte

    2016-03-01

    Full Text Available The cycloaddition of pyridinium ylides with alkynes was investigated under mild conditions. A series of 13 pyridinium salts was prepared by alkylation of 4-substituted pyridines. Their reactivity with propiolic ester or amide in various reaction conditions (different temperatures, solvents, added bases was studied, and 11 indolizines, with three points of structural variation, were, thus, isolated and characterized. The highest yields were obtained when electron-withdrawing groups were present on both the pyridinium ylide, generated in situ from the corresponding pyridinium salt, and the alkyne (X, Z = ester, amide, CN, carbonyl, etc.. Electron-withdrawing substituents, lowering the acid dissociation constant (pKa of the pyridinium salts, allow the cycloaddition to proceed at pH 7.5 in aqueous buffers at room temperature.

  11. Rapacuronium bromide (Organon Teknika).

    Science.gov (United States)

    Plowman, A N

    1999-07-01

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

  12. Methylnaltrexone bromide methanol monosolvate

    Directory of Open Access Journals (Sweden)

    Xinbo Zhou

    2012-03-01

    Full Text Available In the title compound [systematic name: (4R,4aS,7aR,12bS-3-cyclopropylmethyl-4a,9-hydroxy-7-oxo-2,3,4,4a,5,6,7,7a-octahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-3-ium bromide methanol monosolvate], C21H26NO4+·Br−·CH3OH, two of the three six-membered rings adopt chair conformations while the third, which contains a C=C double bond, adopts an approximate half-boat conformation. The 2,3-dihydrofuran ring adopts an envelope conformation. In the crystal, the components are linked by O—H...O and O—H...Br hydrogen bonds. The absolute stereochemistry was inferred from one of the starting materials.

  13. Iron bromide vapor laser

    Science.gov (United States)

    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.

  14. Ultraviolet photodissociation action spectroscopy of the N-pyridinium cation

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Christopher S., E-mail: csh297@uowmail.edu.au; Trevitt, Adam J., E-mail: adamt@uow.edu.au [School of Chemistry, University of Wollongong, NSW 2522 (Australia); Blanksby, Stephen J. [Central Analytical Research Facility, Queensland University of Technology, QLD 4000 (Australia); Chalyavi, Nahid; Bieske, Evan J. [School of Chemistry, The University of Melbourne, VIC 3010 (Australia); Reimers, Jeffrey R. [School of Physics and Materials Science, University of Technology Sydney, NSW 2007 (Australia); International Centre for Quantum and Molecular Structure, Shanghai University, Shanghai 200444 (China)

    2015-01-07

    The S{sub 1}←S{sub 0} electronic transition of the N-pyridinium ion (C{sub 5}H{sub 5}NH{sup +}) is investigated using ultraviolet photodissociation (PD) spectroscopy of the bare ion and also the N{sub 2}-tagged complex. Gas-phase N-pyridinium ions photodissociate by the loss of molecular hydrogen (H{sub 2}) in the photon energy range 37 000–45 000 cm{sup −1} with structurally diagnostic ion-molecule reactions identifying the 2-pyridinylium ion as the exclusive co-product. The photodissociation action spectra reveal vibronic details that, with the aid of electronic structure calculations, support the proposal that dissociation occurs through an intramolecular rearrangement on the ground electronic state following internal conversion. Quantum chemical calculations are used to analyze the measured spectra. Most of the vibronic features are attributed to progressions of totally symmetric ring deformation modes and out-of-plane modes active in the isomerization of the planar excited state towards the non-planar excited state global minimum.

  15. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2013 . S tatement on the safety of ' Cetyl Myristoleate Complex ' as an ingredient in food supplements

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to update its opinion on the safety of „Cetyl Myristoleate Complex‟ (CMC) as a novel food ingredient in the light of a new repeated dose 90-day oral toxicity study in mice. In its p...... supporting the absence of adverse effects of the parent material CMC. The Panel concludes that the safety of 'Cetyl Myristoleate Complex' has not been established. © European Food Safety Authority, 2013...

  16. 5-(Pyridinium-3-yltetrazol-1-ide hexaaquamagnesium dichloride

    Directory of Open Access Journals (Sweden)

    Jing Dai

    2011-02-01

    Full Text Available In the title compound, (C6H5N52[Mg(H2O6]Cl2, the asymmetric unit contains one zwitterionic 5-(pyridinium-3-yltetrazol-1-ide molecule, one half of an [Mg(H2O6]2+ cation (overline{1} symmetry and one chloride ion. The MgII ion is surrounded by six water molecules, with their O atoms located at the apices, exhibiting a slightly distorted octahedral coordination. Mg—O bond lengths range from 2.0526 (14 to 2.0965 (16 Å [mean value = 2.068 Å]. The pyridine and tetrazole rings are nearly coplanar and only twisted from each other by a dihedral angle of 5.68 (1°. The zwitterionic organic molecules, anions and cations are connected by O—H...Cl, O—H...N and N—H...Cl hydrogen bonds, leading to the formation of a three-dimensional network.

  17. Reverse Anomeric Effect in Large-Amplitude Pyridinium Amide-Containing Mannosyl [2]Rotaxane Molecular Shuttles.

    Science.gov (United States)

    Riss-Yaw, Benjamin; Waelès, Philip; Coutrot, Frédéric

    2016-06-17

    The reverse anomeric effect (RAE) was investigated in different mannosyl [2]rotaxane molecular shuttle isomers that contain dibenzo-24-crown-8 (DB24C8) as the macrocycle, and anilinium and pyridinium amide as molecular stations. The switching on or off of the RAE was possible depending on both the pyridinium amide motif and the localization of the DB24C8 along the thread. The (1) C4 mannopyranosyl chair-like conformation was observed in all the non-interlocked molecules because the anomeric carbon of the mannose is linked to the positively charged nitrogen of the pyridinium unit. In the protonated rotaxanes, the (1) C4 chair conformation of the mannose end remains because the DB24C8 resides around the best anilinium station, which is located at the other end of the axle. Upon deprotonation of the anilinium, the DB24C8 shuttles with a large-amplitude motion toward the pyridinium amide stations, where it interacts in a different fashion depending on the pyridinium motif. In one molecular shuttle, the RAE could be switched on or off with control at one end of the encircled thread upon protonation/deprotonation of the other end, through shuttling of the DB24C8. PMID:27062432

  18. Modulation of pyridinium cationic lipid-DNA complex properties by pyridinium gemini surfactants and its impact on lipoplex transfection properties.

    Science.gov (United States)

    Sharma, Vishnu Dutt; Lees, Julia; Hoffman, Nicholas E; Brailoiu, Eugen; Madesh, Muniswamy; Wunder, Stephanie L; Ilies, Marc A

    2014-02-01

    The study presents the effects of blending a cationic gemini surfactant into cationic lipid bilayers and its impact on the plasmid DNA compaction and delivery process. Using nanoDSC, dynamic light scattering, zeta potential, and electrophoretic mobility measurements, together with transfection (2D- and 3D-) and viability assays, we identified the main physicochemical parameters of the lipid bilayers, liposomes, and lipoplexes that are affected by the gemini surfactant addition. We also correlated the cationic bilayer composition with the dynamics of the DNA compaction process and with transfection efficiency, cytotoxicity, and the internalization mechanism of the resultant nucleic acid complexes. We found that the blending of gemini surfactant into the cationic bilayers fluidized the supramolecular assemblies, reduced the amount of positive charge required to fully compact the plasmid DNA and, in certain cases, changed the internalization mechanism of the lipoplexes. The transfection efficiency of select ternary lipoplexes derived from cationic gemini surfactants and lipids was several times superior to the transfection efficiency of corresponding binary lipoplexes, also surpassing standard transfection systems. The overall impact of gemini surfactants into the formation and dynamic of cationic bilayers was found to depend heavily on the presence of colipids, their nature, and amount present in lipoplexes. The study confirmed the possibility of combining the specific properties of pyridinium gemini surfactants and cationic lipids synergistically to obtain efficient synthetic transfection systems with negligible cytotoxicity useful for therapeutic gene delivery. PMID:24377350

  19. Preparation of Iron-nickel Alloy Nanostructures via Two Cationic Pyridinium Derivatives as Soft Templates

    Directory of Open Access Journals (Sweden)

    Jingxin Zhou

    2015-09-01

    Full Text Available In this paper, crystalline iron-nickel alloy nanostructures were successfully prepared from two cationic pyridinium derivatives as soft templates in solution. The crystal structure and micrograph of FeNi alloy nanostructures were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the content was confirmed by energy-dispersive spectrometry. The results indicated that the as-prepared nanostructures showed slightly different diameter ranges with the change of cationic pyridinium derivatives on the surface. The experimental data indicated that the adsorption of cationic pyridinium compounds on the surface of particles reduces the surface charge, leading to an isotropic distribution of the residual surface charges. The magnetic behaviours of as-prepared FeNi alloy nanostructures exhibited disparate behaviours, which could be attributed to their grain sizes and distinctive structures. The present work may give some insight into the synthesis and character of new alloy nanomaterials with special nanostructures using new soft templates.

  20. Disruption of insect isoprenoid biosynthesis with pyridinium bisphosphonates.

    Science.gov (United States)

    Sen, Stephanie E; Wood, Lyndsay; Jacob, Reshma; Xhambazi, Alisa; Pease, Britanny; Jones, Alexis; Horsfield, Taylor; Lin, Alice; Cusson, Michel

    2015-08-01

    Farnesyl diphosphate synthase (FPPS) catalyzes the condensation of the non-allylic diphosphate, isopentenyl diphosphate (IPP; C5), with the allylic diphosphate primer dimethylallyl diphosphate (DMAPP; C5) to generate the C15 prenyl chain (FPP) used for protein prenylation as well as sterol and terpene biosynthesis. Here, we designed and prepared a series of pyridinium bisphosphonate (PyrBP) compounds, with the aim of selectively inhibiting FPPS of the lepidopteran insect order. FPPSs of Drosophila melanogaster and the spruce budworm, Choristoneura fumiferana, were inhibited by several PyrBPs, and as hypothesized, larger bisphosphonates were more selective for the lepidopteran protein and completely inactive towards dipteran and vertebrate FPPSs. Cell growth of a D. melanogaster cell line was adversely affected by exposure to PyrPBs that were strongly inhibitory to insect FPPS, although their effect was less pronounced than that observed upon exposure to the electron transport disrupter, chlorfenapyr. To assess the impact of PyrBPs on lepidopteran insect growth and development, we performed feeding and topical studies, using the tobacco hornworm, Manduca sexta, as our insect model. The free acid form of a PyrBP and a known bisphosphonate inhibitor of vertebrate FPPS, alendronate, had little to no effect on larval M. sexta; however, the topical application of more lipophilic ester PyrBPs caused decreased growth, incomplete larval molting, cuticle darkening at the site of application, and for those insects that survived, the formation of larval-pupal hybrids. To gain a better understanding of the structural differences that produce selective lepidopteran FPPS inhibition, homology models of C. fumiferana and D. melanogaster FPPS (CfFPPS2, and DmFPPS) were prepared. Docking of substrates and PyrBPs demonstrates that differences at the -3 and -4 positions relative to the first aspartate rich motif (FARM) are important factors in the ability of the lepidopteran enzyme to

  1. Tandem dinucleophilic cyclization of cyclohexane-1,3-diones with pyridinium salts

    Directory of Open Access Journals (Sweden)

    Mostafa Kiamehr

    2013-06-01

    Full Text Available The cyclization of cyclohexane-1,3-diones with various substituted pyridinium salts afforded functionalized 8-oxa-10-aza-tricyclo[7.3.1.02,7]trideca-2(7,11-dienes. The reaction proceeds by regioselective attack of the central carbon atom of the 1,3-dicarbonyl unit to 4-position of the pyridinium salt and subsequent cyclization by base-assisted proton migration and nucleophilic addition of the oxygen atom to the 2-position, as was elucidated by DFT computations. Fairly extensive screening of bases and additives revealed that the presence of potassium cations is essential for formation of the product.

  2. Tandem dinucleophilic cyclization of cyclohexane-1,3-diones with pyridinium salts

    OpenAIRE

    Mostafa Kiamehr; Firouz Matloubi Moghaddam; Satenik Mkrtchyan; Volodymyr Semeniuchenko; Linda Supe; Alexander Villinger; Peter Langer; Iaroshenko, Viktor O.

    2013-01-01

    The cyclization of cyclohexane-1,3-diones with various substituted pyridinium salts afforded functionalized 8-oxa-10-aza-tricyclo[7.3.1.02,7]trideca-2(7),11-dienes. The reaction proceeds by regioselective attack of the central carbon atom of the 1,3-dicarbonyl unit to 4-position of the pyridinium salt and subsequent cyclization by base-assisted proton migration and nucleophilic addition of the oxygen atom to the 2-position, as was elucidated by DFT computations. Fairly extensive screening of ...

  3. 2-Alkynyl-N-propargyl pyridinium salts: pyridinium-based heterocyclic skipped aza-enediynes that cleave DNA by deoxyribosyl hydrogen-atom abstraction and guanine oxidation.

    Science.gov (United States)

    Tuesuwan, Bodin; Kerwin, Sean M

    2006-06-13

    Diradical-generating cyclizations such as the enediyne Bergman cyclization and the enyne allene Myers-Saito cyclization have been exploited by nature in the mechanism of DNA cleavage by a series of potent antitumor antibiotics. Alternative diradical-generating cyclizations have been proposed in the design of selective antitumor agents; however, little information is available concerning the utility of these alternative cyclizations in radical-based DNA cleavage chemistry. One such alternative diradical-generating cyclization, the aza-Myers-Saito cyclization of aza-enyne allenes that are derived from base-promoted isomerization of skipped aza-enediynes, has been recently reported. Here, we report the synthesis and DNA cleavage chemistry of a series of pyridinium skipped aza-enediynes (2-alkynyl-N-propargyl pyridinium salts). Efficient DNA cleavage requires the presence of the skipped aza-enediyne functionality, and optimal DNA cleavage occurs at basic pH. Within this series of compounds, the analogue bearing a p-methoxyphenyl group on the pyridinium 2-alkyne substituents was found to be the most effective DNA cleavage agent, displaying significant supercoiled DNA-nicking activity at concentrations as low as 1 microM. Detailed studies of this analogue show that DNA cleavage occurs through 4'-hydrogen-atom abstraction from the DNA backbone and oxidation of guanine bases. This is the first report of enediyne-like radical-based DNA cleavage by an agent designed to undergo an alternative diradical-generating cyclization. PMID:16752915

  4. Pyridinium hydrobromide perbromide: a versatile catalyst for aziridination of olefins using Chloramine-T.

    Science.gov (United States)

    Ali, S I; Nikalje, M D; Sudalai, A

    1999-09-01

    [reaction: see text] Pyridinium hydrobromide perbromide (Py x HBr3) catalyzes effectively the aziridination of electron-deficient as well as electron-rich olefins using Chloramine-T (N-chloro-N-sodio-p-toluenesulfonamide) as a nitrogen source to afford the corresponding aziridines in moderate to good yields. PMID:16118868

  5. Pyridinium tribromide catalyzed condensation of indoles and aldehydes to form bisindolylalkanes

    Institute of Scientific and Technical Information of China (English)

    Qin Yang; Zheng Lan Yin; Ban Lai Ouyang; Yi Yuan Peng

    2011-01-01

    An efficient synthetic method for bis(indol-3-yl)alkane derivatives has been developed. In the presence of 5 mol% of pyridinium tribromide (PTB), the condensation of indoles and aldehydes proceeded smoothly under mild conditions, giving rise to the corresponding bis(indol-3-yl)alkanes in good to excellent yields.

  6. The influence of detergents, sodium tripoly-phosphates and ethoxyled oleyl-cetyl alcohol on metabolism of the fungi Penicillium verrucosum peyronel

    OpenAIRE

    Stojanović Jelica; Jakovljević Violeta; Matović Ivana; Mijušković Z.; Nedeljković T.

    2010-01-01

    On the species of the fungi Penicillium verrucosum grown on liquid nutritious base, according to Czapek and on a variation of the same nutritious base with detergent MERIX ('Merima', Krusevac) and individual components of the same detergent: sodium tripolyphosphate and ethoxyled oleyl-cetyl alcohol in a concentration of 0.1%, the following analyses were performed: pH, redox potential, proteolytic activity, the quantity of free and total organic acids, amino acids, pr...

  7. Immobilized Rhizopus oryzae lipase catalyzed synthesis of palm stearin and cetyl alcohol wax esters: Optimization by Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Gargouri Youssef

    2011-06-01

    Full Text Available Abstract Background Waxes are esters of long-chain fatty acids and long-chain alcohols. Their principal natural sources are animals (sperm whale oil and vegetables (jojoba which are expensive and not easily available. Wax esters synthesized by enzymatic transesterification, using palm stearin as raw material, can be considered as an alternative to natural ones. Results Palm stearin is a solid fraction obtained by fractionation of palm oil. Palm stearin was esterified with cetyl alcohol to produce a mixture of wax esters. A non-commercial immobilized lipase from Rhizopus oryzae was used as biocatalyst. Response surface methodology was employed to determine the effects of the temperature (30-50°C, the enzyme concentration (33.34-300 IU/mL, the alcohol/palm stearin molar ratio (3-7 mol/mol and the substrate concentration (0.06-0.34 g/mL on the conversion yield of palm stearin. Under optimal conditions (temperature, 30°C; enzyme concentration, 300 IU/mL; molar ratio 3 and substrate concentration 0.21 g/mL a high conversion yield of 98.52% was reached within a reaction time of 2 h. Conclusions Response surface methodology was successfully applied to determine the optimum operational conditions for synthesis of palm stearin based wax esters. This study may provide useful tools to develop economical and efficient processes for the synthesis of wax esters.

  8. Methacryloxylethyl Cetyl Ammonium Chloride Induces DNA Damage and Apoptosis in Human Dental Pulp Cells via Generation of Oxidative Stress.

    Science.gov (United States)

    Jiao, Yang; Ma, Sai; Wang, Yirong; Li, Jing; Shan, Lequn; Sun, Jinlong; Chen, Jihua

    2016-01-01

    The polymerizable antibacterial monomer methacryloxylethyl cetyl ammonium chloride (DMAE-CB) has provided an effective strategy to combat dental caries. However, the application of such material raises the question about the biological safety and the question remains open. The mechanism of this toxic action, however, is not yet clearly understood. The present study aims at providing novel insight into the possible causal link between cellular oxidative stress and DNA damage, as well as apoptosis in human dental pulp cells exposed to DMAE-CB. The enhanced formation of reactive oxygen species and depletion of glutathione, as well as differential changes in activities of superoxide dismutase, glutathione peroxidase, and catalase in DMAE-CB-treated cells indicated oxidative stress. By using substances that can alter GSH synthesis, we found that GSH was the key component in the regulation of cell response towards oxidative stress induced by DMAE-CB. The increase in oxidative stress-sensitive 8-Oxo-2'-deoxyguanosine (8-OHdG) content, formation of γ-H2AX and cell cycle G1 phase arrest indicated that DNA damage occurred as a result of the interaction between DNA base and ROS beyond the capacities of antioxidant mechanisms in cells exposed to DMAE-CB. Such oxidative DNA damage thus triggers the activation of ataxia telangiectasia-mutated (ATM) signaling, the intrinsic apoptotic pathway, and destruction of mitochondrial morphology and function. PMID:27143955

  9. Conversion of Alcohols to Bromides by Trimethylsilane and lithium Bromide in Acetone

    Institute of Scientific and Technical Information of China (English)

    Wei Feng; Zhang Xiao-xia; Zhang Qing; Wang Ji-yu; Chen Dai-mo

    2004-01-01

    Conversion of alcohols to alkyl bromides is one of the most frequently used functional group transformation reactions. Phosphorus tribromide is one of the most popular classical reagents.Triphenylphosphine has been used in combination with bromine,carbon tetrabromide,N-halo imides and other bromide compounds as a mild reagents for the preparation of alkyl bromides.More reacently, halotrimethylsilanes were found to be useful for halogenation of alcohols. George A.Olah successfully converted alcohols to bromides with chlorotrimethylsilane/lithium bromide in acetonitrile. But in our research, we found that we got no bromides but methylation products when we planed to convered our substances to bromides according to Gerge's method. We did some experiments, and we found that when the substituent group in the 2-N was donor group,we got the methylation products,but when it was acceptor group,the bromide could be got.(Scheme 1).Then we did some experiments with several other solvents, we found excitedly that when the solvent was acetone ,the bromides could be got even the substituent group was donor.(Scheme 2).When we changed the substances to normal alcohols ,such as ethyl alcohol,benzyl alcohol,isopropyl alcohol and 3,4-dimethoxy benzyl alcohol,we also got the bromides.In conclusion, we found a simple method to convert alcohols to bromides with trimethylsilane/li thium bromide in acetone,which was better than Geroge's method.

  10. Oxygen versus nitrogen interactions in lithium dinitramidate dihydrate and pyridinium dinitramidate.

    Science.gov (United States)

    Klapötke, Thomas M; Krumm, Burkhard; Scherr, Matthias

    2008-01-01

    The title compounds, diaquadinitramidatolithium(I), [Li(N3O4)(H2O)2], (I), and pyridinium dinitramidate, C5H6N+ x N3O4(-), (II), differ significantly in their cation-anion contacts. The Li+ atom of (I) is coordinated by two O atoms of the dinitramide anion in a chelate and by four additional water molecules, with the Li and central N atom of the anion on a twofold rotation axis. The pyridinium cation of (II) exhibits a contact with the dinitramide anion via an intermolecular N-H...N hydrogen bridge. These interactions are compared with those found in reported anhydrous lithium dinitramide and ammonium dinitramide salts. PMID:18216429

  11. Densities and Derived Thermodynamic Properties of Imidazolium-, Pyridinium-, Pyrrolidinium-, and Piperidinium-Based Ionic Liquids

    OpenAIRE

    Gardas, Ramesh L.; Costa, Henrique F.; Freire, Mara G.; Carvalho, Pedro J.; Marrucho, Isabel M.; Fonseca, Isabel M. A.; Ferreira, Abel G. M.; Coutinho, João A. P.

    2008-01-01

    In the present work, experimental density measurements are reported along with the derived thermodynamic properties, such as the isothermal compressibility (κT), the isobaric expansivity (αp), and the thermal pressure coefficient (γv) for imidazolium-, pyridinium-, pyrrolidinium-, and piperidinium-based ionic liquids (ILs), namely, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate [C2mim][CF3SO3], 3-methyl-1-propylpyridinium bis(trifluoromethylsulfonyl)imide [C3mpy][NTf2], 1-methyl-1-prop...

  12. Stereoselective Synthesis of Polysubstituted Cyclopropanes from Poly(ethylene glycol)Supported Pyridinium Ylide

    Institute of Scientific and Technical Information of China (English)

    ZHAO Pan; LU Cui-fen; YANG Gui-chun; CHEN Zu-xing; DONG Nian-guo; SHI Jia-wei

    2011-01-01

    Polysubstituted cyclopropanes were efficiently prepared with poly(ethylene glycol)(PEG)as soluble support.The reaction of PEG-supported pyridinium ylide with arylidenemalononitrile(R=CN)or ethyl arylidenecyanoacetate(R=COOEt)in the presence of triethylamine(TEA)afforded PEG-supported cyclopropanecarboxylates,which were cleaved by 1% KCN/EtOH to obtain polysubstituted cyclopropanes with exclusive trans-selectivity and good yields.

  13. The interactions between lipase and pyridinium ligands investigated by electrochemical and spectrophotometric methods

    Directory of Open Access Journals (Sweden)

    Simona Patriche

    2016-04-01

    Full Text Available The interaction between pyridinium ligands derived from 4,4’-bipyridine (N,N’-bis(p-bromophenacyl-4,4’-bipyridinium dibromide – Lr and (N,N’-bis(p-bromophenacyl-1,2-bis (4-pyridyl ethane dibromide – Lm with lipase enzyme was evaluated. The stability of the pyridinium ligands, having an essential role in biological systems, in 0.1 M KNO3 as supporting electrolyte is influenced by the lipase concentration added. The pH and conductometry measurements in aqueous solution suggest a rapid ionic exchange process. The behavior of pyridinium ligands in the presence of lipase is investigated by cyclic voltammetry and UV/Vis spectroscopy, which indicated bindings and changes from the interaction between them. The voltammograms recorded on the glassy carbon electrode showed a more intense electronic transfer for the Lr interaction with lipase compared to Lm, which is due to the absence of mobile ethylene groups from Lr structure.

  14. Investigation of drug interactions with pinaverium bromide.

    Science.gov (United States)

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

    1986-01-01

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

  15. A one-dimensional CdII coordination polymer constructed from 4-(dimethylamino)pyridinium-1-acetate ligands and thiocyanate coordination bridges.

    Science.gov (United States)

    Wang, Hui-Ting; Zhou, Lin

    2015-07-01

    A new cadmium-thiocyanate complex, namely catena-poly[1-carboxymethyl-4-(dimethylamino)pyridinium [cadmium(II)-tri-μ-thiocyanato-κ(4)N:S;κ(2)S:N] [[[4-(dimethylamino)pyridinium-1-acetate-κ(2)O,O']cadmium(II)]-di-μ-thiocyanato-κ(2)N:S;κ(2)S:N

  16. Oxidative Desulfurization of Fuel Oil by Pyridinium-Based Ionic Liquids

    OpenAIRE

    Erhong Duan; Dishun Zhao; Yanan Wang

    2009-01-01

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF4 has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H2O2) = 1:1:0.4, temperature 55 °C, the time 30 min. The ...

  17. Synthesis and Characterization of Ammonium-, Pyridinium-, and Pyrrolidinium-Based Sulfonamido Functionalized Ionic Liquids

    DEFF Research Database (Denmark)

    Shunmugavel, Saravanamurugan; Fehrmann, Rasmus; Riisager, Anders

    2012-01-01

    New homologous ammonium-, pyridinium-, and pyrrolidinium-based sulfonamido functionalized ionic liquids have been synthesized in two steps using monoethanolamine, methanesulfonyl chloride, and tosyl chloride as precursors with ethanol as solvent. Attempts to synthesize dual amino functionalized...... ionic liquid containing both a primary and a secondary amine group in the same ionic liquid are also reported. All functionalized ionic liquids were characterized by 1H and 13C NMR. Melting point and thermal stability of the functionalized ionic liquids were measured by differential scanning calorimetry...

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

    Science.gov (United States)

    Guslandi, M

    1994-04-01

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

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

    Science.gov (United States)

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

    1986-01-01

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

  20. CuO nanostructures: optical properties and morphology control by pyridinium-based ionic liquids.

    Science.gov (United States)

    Sabbaghan, Maryam; Shahvelayati, Ashraf Sadat; Madankar, Kamelia

    2015-01-25

    Copper oxide nanostructures have been synthesized by a simple reflux method in aqueous medium of pyridinium based ionic liquids. The structural and optical properties of CuO nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence spectroscopy (PL) and UV-visible. The morphologies of the nanostructures can be controlled by changing the amount of NaOH and ionic liquids. The results show that the use identical pyridinium based ionic liquids in ratio of 4:1 NaOH/Cu(OAc)2⋅H2O yield minor differences in morphology of CuO nanostructures. Different morphologies of CuO nanostructures were obtained by changing the ratio NaOH/Cu(OAc)2⋅H2O to 2:1. Ionic liquids play an important role on optical properties of CuO nanostructures. The results of optical measurements of the CuO nanostructures illustrate that band gaps are estimated to be 1.67-1.85 eV. PL patterns studies show that the ionic liquids can be effect on PL patterns of the samples. The reasons of these phenomena are discussed.

  1. Using Pyridinium Styryl Dyes as the Standards of Time-Resolved Instrument Response.

    Science.gov (United States)

    Li, Lei; Chang, Mengfang; Yi, Hua; Jia, Menghui; Cao, Xiaodan; Zhou, Zhongneng; Zhang, Sanjun; Pan, Haifeng; Shih, Chun-Wei; Jimenez, Ralph; Xu, Jianhua

    2016-07-01

    In this paper, two pyridinium styryl dyes, [2-(4-dimethylamino-phenyl)-vinyl]-1-methylpyridinium iodide (DASPMI), were synthesized and characterized by steady state fluorescence spectroscopy as well as picosecond and femtosecond time-resolved fluorescence spectroscopies. Both dyes exhibit large Stokes shifts and fluorescence decays equivalent to the instrument response function (IRF) standards employed in time-correlated single-photon counting. Due to their styryl and pyridinium moieties, DASPMIs have higher peak fluorescence intensity and shorter excited-state lifetimes than iodide ion-quenched fluorophores. The fluorescence lifetimes of o-DASPMI and p-DASPMI were measured to be 6.6 ps and 12.4 ps, respectively. The fluorescence transients of these DASPMIs were used as the IRFs for iterative reconvolution fitting of the time-resolved fluorescence decay profiles of Rhodamine B (RhB), sulforhodamine B (SRB), and the SRB-SRB2m RNA aptamer complex. The quality of the fits employing the DASPMI-derived IRFs are consistently equivalent to those employing IRFs obtained from light scattering. These results indicate that DASPMI-derived IRFs may be suited for a broad range of applications in time-resolved spectroscopy and fluorescence lifetime imaging microscopy (FLIM), especially in the visible emission range. PMID:27231333

  2. Antibacterial/Antiviral Property and Mechanism of Dual-Functional Quaternized Pyridinium-type Copolymer

    Directory of Open Access Journals (Sweden)

    Yan Xue

    2015-11-01

    Full Text Available Due to the massive outbreaks of pathogen-caused diseases and the increase of drug-resistant pathogens, there is a particular interest in the development of novel disinfection agents with broad-spectrum antipathogenic activity. In the present study, water-soluble pyridinium-type polyvinylpyrrolidones with different counter anions were prepared. Structural characterization was conducted via 13C–1H heteronuclear single quantum coherence spectroscopy, static light scattering, UV spectrometry and apparent charge density. The influence of counter anion and polymer compositions on the antibacterial activity was studied against Staphylococcus aureus and Escherichia coli. Atomic force microscopy (AFM was applied for tracking the morphological alterations in bacterial cells induced by prepared polycations. It was found that the exposure of bacteria to the polycations resulted in the destruction of cell membranes and the leakage of cytoplasm. The antiviral activity of pyridinium-type polycations against enveloped influenza virus was evaluated via a plaque assay. The action mode against enveloped virus was depicted to rationalize the antiviral mechanism.

  3. Polymorphism of pyridinium amphiphiles for gene delivery : Influence of ionic strength, helper lipid content, and plasmid DNA complexation

    NARCIS (Netherlands)

    Scarzello, M; Chupin, [No Value; Wagenaar, A; Stuart, MCA; Engberts, JBFN; Hulst, R; Chupin, Vladimir

    2005-01-01

    Two double-tailed pyridinium cationic amphiphiles, differing only in the degree of unsaturation of the alkyl chains, have been selected for a detailed study of their aggregation behavior, under conditions employed for transfection experiments. The transfection efficiencies of the two molecules are r

  4. Electrical polarization of lead bromide crystals. I

    NARCIS (Netherlands)

    Schoonman, A.; Macke, A.J.H.

    1972-01-01

    An attempt was made to measure electronic conductivity in lead bromide in equilibrium with lead, since experimental data on the cell −Pb/PbBr2/C+ in the literature are not consistent with existing theories. Combination of our results with published data for bromine-induced hole conduction in lead br

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

    Science.gov (United States)

    Defrance, P; Casini, A

    1991-11-01

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

  6. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Statement on the safety of ‘Cetyl Myristoleate Complex’ as an ingredient in food supplements

    DEFF Research Database (Denmark)

    Tetens, Inge

    Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked to update its opinion on the safety of ‘Cetyl Myristoleate Complex’ (CMC) as a novel food ingredient in the light of additional information submitted by the applicant. In its previous...... opinion of 2010, the Panel concluded that the safety of CMC as an ingredient in food supplements at an intake of 3.3 g per day has not been established. This conclusion was based on the considerations that in the absence of appropriate data on absorption, distribution, metabolism and excretion...... 90-day study cannot serve as a reliable source of information supporting the absence of adverse effects of CMC. The dossier of this new mandate contains three new references which were not submitted and hence not considered in the previous assessments. The Panel notes that two references do...

  7. Oxidative Desulfurization of Fuel Oil by Pyridinium-Based Ionic Liquids

    Directory of Open Access Journals (Sweden)

    Erhong Duan

    2009-10-01

    Full Text Available In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF4 was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT was investigated. Ionic liquids and hydrogen peroxide (30% were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF4 has a better desulfurization effect. The best technological conditions are: V(IL/V(Oil /V(H2O2 = 1:1:0.4, temperature 55 °C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration.

  8. Oxidative desulfurization of fuel oil by pyridinium-based ionic liquids.

    Science.gov (United States)

    Zhao, Dishun; Wang, Yanan; Duan, Erhong

    2009-01-01

    In this work, an N-butyl-pyridinium-based ionic liquid [BPy]BF(4) was prepared. The effect of extraction desulfurization on model oil with thiophene and dibenzothiophene (DBT) was investigated. Ionic liquids and hydrogen peroxide (30%) were tested in extraction-oxidation desulfurization of model oil. The results show that the ionic liquid [BPy]BF(4) has a better desulfurization effect. The best technological conditions are: V(IL)/V(Oil) /V(H(2)O(2)) = 1:1:0.4, temperature 55 degrees C, the time 30 min. The ratio of desulfurization to thiophene and DBT reached 78.5% and 84.3% respectively, which is much higher than extraction desulfurization with simple ionic liquids. Under these conditions, the effect of desulfurization on gasoline was also investigated. The used ionic liquids can be recycled up to four times after regeneration. PMID:19924069

  9. Three silver (I) supramolecular compounds constructed from pyridinium or methylimidazolium polycations: Synthesis, crystal structure and properties

    Indian Academy of Sciences (India)

    Yao Li; Wen Li Zhang; Hai Juan Du; Chao-Hai Wang; Ya Bin Lu; Yun-Yin Niu

    2015-09-01

    Three metal halide cluster supramolecular polymers, {(TBP)[Ag3Br6]}n (1), {(TBI)[Ag3Br6]}n (2) and {(TBP)[Ag3I6]}n (3) (TBP=1, 3, 5-tris(N-pyridinium methyl)benzene, TBI=1, 3, 5-tris(methylimidazole methyl)benzene), have been synthesized and characterized by thermoanalysis and spectroscopic methods, as well as single-crystal X-ray diffraction. Complexes 1, 2 and 3 all feature a one-dimensional chain structure, which is further extended by electrostatic attraction. The TGA, UV-Vis diffuse reflectance spectra in the solid state and optical band gap properties of the three complexes were also investigated.

  10. Methyl bromide residues in fumigated cocoa beans

    International Nuclear Information System (INIS)

    The 14C activity in unroasted [14C]-methyl bromide fumigated cocoa beans was used to study the fate and persistence of CH3Br in the stored beans. About 70% of the residues occurred in the shells. Unchanged CH3Br could not be detected, all the sorbed CH3Br having reacted with bean constituents apparently to form 14C-methylated derivatives and inorganic bromide. No 14C activity was found in the lipid fraction. Roasting decreased the bound (non-volatile) residues, with corresponding changes in the activities and amounts of free sugars, free and protein amino acids. Roasted nibs and shells showed a two-fold increase in the volatile fraction of the 14C residue. This fraction may be related to the volatile aroma compounds formed by Maillard-type reactions. (author)

  11. An Eco-Friendly Ultrasound-Assisted Synthesis of Novel Fluorinated Pyridinium Salts-Based Hydrazones and Antimicrobial and Antitumor Screening

    OpenAIRE

    Nadjet Rezki; Salsabeel A. Al-Sodies; Mohamed R. Aouad; Sanaa Bardaweel; Mouslim Messali; El Ashry, El Sayed H.

    2016-01-01

    The present work reports an efficient synthesis of fluorinated pyridinium salts-based hydrazones under both conventional and eco-friendly ultrasound procedures. The synthetic approach first involves the preparation of halogenated pyridinium salts through the condensation of isonicotinic acid hydrazide (1) with p-fluorobenzaldehyde (2) followed by the nucleophilic alkylation of the resulting N-(4-fluorobenzylidene)isonicotinohydrazide (3) with a different alkyl iodide. The iodide counteranion ...

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

    Science.gov (United States)

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

    2014-12-01

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

  13. Small-angle neutron scattering study of aggregate structures of multi-headed pyridinium surfactants in aqueous solution

    Indian Academy of Sciences (India)

    J Haldar; V K Aswal; P S Goyal; S Bhattacharya

    2004-08-01

    The aggregate structures of a set of novel single-chain surfactants bearing one, two and three pyridinium headgroups have been studied using small-angle neutron scattering (SANS). It is found that the nature of aggregate structures of these cationic surfactants depend on the number of headgroups present in the surfactants. The single-headed pyridinium surfactant forms the lamellar structure, whereas surfactants with double and triple headgroups form micelles in water. The aggregates shrink in size with increase in the number of headgroups in the surfactants. The aggregation number () continually decreases and the fractional charge () increases with more number of headgroups on the surfactants. The semimajor axis () and semiminor axis ( = ) of the micelle also decrease with the increase in the number of headgroups in the surfactants. This indicates that hydrocarbon chains in such micelles prepared from multiheaded surfactants adopt bent conformation and no longer stay in extended conformation.

  14. Europium-doped barium bromide iodide

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. 2-((1E-1-{2-[(2Z-3,4-Diphenyl-2,3-dihydro-1,3-thiazol-2-ylidene]hydrazin-1-ylidene}ethylpyridin-1-ium bromide monohydrate

    Directory of Open Access Journals (Sweden)

    Mehmet Akkurt

    2014-04-01

    Full Text Available In the title compound, C22H19N4S+·Br−·H2O, the dihedral angles between the phenyl groups and the mean plane of the thiazolylidene ring are 34.69 (13 and 64.27 (13°, respectively, while that between the thiazolylidene and pyridinium rings is 14.73 (13°. In the crystal, zigzag chains of alternating bromide ions and water molecules associate through O—H...Br interactions run in channels approximately parallel to the b axis. These chains help form parallel chains of cations through N—H...O, C—H...N and C—H...Br hydrogen bonds.

  16. Density, dynamic viscosity, and electrical conductivity of pyridinium-based hydrophobic ionic liquids

    International Nuclear Information System (INIS)

    Highlights: • Targets of this research are hydrophobic series ionic liquids. • Density, dynamic viscosity and electrical conductivity were determined. • Influences of methylene to properties were discussed. • Influences of methyl group on pyridinium ring position to properties were discussed. • Relationship of ρ, η and σ were described systematically. -- Abstract: Air and water stable hydrophobic ionic liquids (ILs) were synthesized: N-propyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide [C33mpy][NTf2], N-hexyl-3-methylpyridinium bis(trifluoromethylsulfonyl)imide [C63mpy][NTf2], and N-hexyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide [C64mpy][NTf2]. Density, dynamic viscosity, and electrical conductivity of ILs were determined at atmospheric pressure in the temperature range of (278 to 353) K. The effects of methylene and methyl groups to density, dynamic viscosity, and electrical conductivity, respectively, were discussed. The thermal expansion coefficient, molecular volume, standard molar entropy, and lattice energy of the samples were estimated in terms of empirical and semi-empirical equations based on the density values. The temperature dependence on dynamic viscosity and electrical conductivity values of the ILs were discussed by Vogel–Fulcher–Tamman (VFT) and Arrhenius equations. The molar conductivities were calculated by density and electrical conductivity values

  17. Growth and characterization of dexterous nonlinear optical material: Dimethyl amino pyridinium 4-nitrophenolate 4-nitrophenol (DMAPNP)

    Science.gov (United States)

    Saravanan, M.

    2016-08-01

    The crystals (dimethyl amino pyridinium 4-nitrophenolate 4-nitrophenol [DMAPNP] suitable for NLO applications were grown by the slow cooling method. The solubility and metastable zone width measurement of DMAPNP specimen was studied. The material crystallizes in the orthorhombic crystal system with noncentrosymmetric space group of P212121. The ocular precision in the intact visible region was found to be good for non-linear optical claim. Quality of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of DMAPNP sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The third order nonlinear optical properties of DMAPNP crystals were premeditated by Z-scan method. Birefringence and optical homogeneity of the crystal were evaluated using modified channel spectrum method. The half wave voltage of the grown crystal deliberate from the elector optic experimentation. Photoconductivity measurement specified consummate of inducing dipoles owing to brawny incident radiation and also disclose the nonlinear activities of the grown specimen.

  18. Poly(phenyl sulfone) anion exchange membranes with pyridinium groups for vanadium redox flow battery applications

    Science.gov (United States)

    Zhang, Bengui; Zhang, Enlei; Wang, Guosheng; Yu, Ping; Zhao, Qiuxia; Yao, Fangbo

    2015-05-01

    To develop high performance and cost-effective membranes with low permeability of vanadium ions for vanadium redox flow battery (VRFB) application, poly(phenyl sulfone) anion exchange membranes with pyridinium groups (PyPPSU) are prepared and first investigated for VRFB application. PyPPSU membranes show much lower vanadium ions permeability (0.07 × 10-7-0.15 × 10-7 cm2 min-1) than that of Nafion 117 membrane (31.3 × 10-7 cm2 min-1). As a result, the self-discharge duration of the VRFB cell with PyPPSU membrane (418 h) is about four times longer than that of VRFB cell with Nafion 117 membrane (110 h). Furthermore, the VRFB cell with PyPPSU membrane exhibits higher battery efficiency (coulombic efficiency of 97.8% and energy efficiency of 80.2%) compare with that of VRFB cell with Nafion 117 membrane (coulombic efficiency of 96.1% and energy efficiency of 77.2%) at a high current density of 100 mA cm-2. In addition, PyPPSU membrane exhibits stable performance in 100-cycle test. The results indicate that PyPPSU membrane is high performance and low-cost alternative membrane for VRFB application.

  19. Improved Cross Validation of a Static Ubiquitin Structure Derived from High Precision Residual Dipolar Couplings Measured in a Drug-Based Liquid Crystalline Phase

    OpenAIRE

    Maltsev, Alexander S.; Grishaev, Alexander; Roche, Julien; Zasloff, Michael; Bax, Ad

    2014-01-01

    The antibiotic squalamine forms a lyotropic liquid crystal at very low concentrations in water (0.3-3.5% w/v), which remains stable over a wide range of temperature (1-40 °C) and pH (4-8). Squalamine is positively charged, and comparison of the alignment of ubiquitin relative to 36 previously reported alignment conditions shows that it differs substantially from most of these, but is closest to liquid crystalline cetyl pyridinium bromide. High precision residual dipolar couplings (RDCs) measu...

  20. 77 FR 20752 - Methyl Bromide; Proposed Pesticide Tolerance

    Science.gov (United States)

    2012-04-06

    ..., which means EPA will not know your identity or contact information unless you provide it in the body of... include your name and other contact information in the body of your comment and with any disk or CD-ROM... methyl bromide. And, although methyl bromide tends to be lipid soluble, the low octanol-water...

  1. Degradation of methyl bromide in anaerobic sediments

    Science.gov (United States)

    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.

  2. Kinetic spectrophotometric determination of bromide in clidinium-c drug

    Institute of Scientific and Technical Information of China (English)

    Ali Sheibani; M. Reza Shishehbore; Zahra Tavakolian Ardakani

    2011-01-01

    A simple, rapid and sensitive method has been described for the determination of the trace amounts of bromide. The method is based on the catalytic effect of bromide ion on the oxidation of methylene blue by bromate in sulfuric acid media. The reaction is monitored spectrophotometrically by measuring the decrease in the absorbance of methylene blue at 665 nm. Bromide was determined in the range of 0.05-1.90 μg/mL with the detection limit of 0.03 μg/mL. The relative standard deviations of five replicate determinations of 0.20 and 10.0 μg/mL of bromide were 2.4% and 1.8%, respectively. The influence of potential interfering ions and substances was studied. The method is applied to the analysis of bromide in clidinium-c tablet as a real sample.

  3. Interaction of pyridinium bis-retinoid (A2E) with bilayer lipid membranes.

    Science.gov (United States)

    Sokolov, V S; Sokolenko, E A; Sokolov, A V; Dontsov, A E; Chizmadzhev, Y A; Ostrovsky, M A

    2007-02-01

    The accumulation of lipofuscin granules within the retinal pigment epithelium (RPE) cells is correlated with the progression of age-related macular degeneration. One of the fluorophores contained in lipofiscin granules is pyridinium bis-retinoid (A2E). To test its membrane-toxic effect, the interaction of A2E with bilayer lipid membranes (BLM) was studied. The incorporation of charged A2E molecules into the membranes has been detected as a change of either zeta-potential of multilayer liposomes or boundary potential of BLM. It was shown that the presence of up to 25mol% of A2E did not destabilize the bilayers made of saturated phosphatidylcholine (PC). However, the destabilizing effect became very significant when BLM contained negatively charged lipids such as cardiolipin or phosphatidylserine. The electrical breakdown measurements revealed that the A2E-induced decrease of BLM stability was primarily associated with the growing probability of lipid pore formation. It was found from the measurements of boundary potential of BLM that exposure of A2E to light initiates its transformation into at least two products. One of them is epoxy-A2E, which, being hydrophilic, moves from the membrane into water solution. The other product is a non-identified hydrophobic substance. Illumination of A2E-containing BLM made from unsaturated PC by visible light caused the membrane damage presumably due to oxidation of these lipids by singlet oxygen generated by excited A2E molecules. However, this effect was very weak compared to the effect of known photosensitizers. The illumination of BLM with A2E also leads to the damage of gramicidin incorporated into the membrane, as was detected by measuring the conductance of channels formed by this peptide. PMID:17070694

  4. Rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography using a monolithic column

    Institute of Scientific and Technical Information of China (English)

    Xu Huang; Hong Yu; Ying Jie Dong

    2012-01-01

    A method for rapid and simultaneous determination of imidazolium and pyridinium ionic liquid cations by ion-pair chromatography with ultraviolet detection was developed.Chromatographic separations were performed on a reversed-phase silica-based monolithic column using 1-heptanesulfonic acid sodium-acetonitrile as mobile phase.The effects of ion-pair reagent and acetonitrile concentration on retention of the cations were investigated.The retention times of the cations accord with carbon number rule.The method has been successfully applied to the determination of four ionic liquids synthesized by organic chemistry laboratory.

  5. Anthracene appended pyridinium amide–urea conjugate in selective fluorometric sensing of L-N-acetylvaline salt

    OpenAIRE

    Kumaresh Ghosh; Tanmay Sarkar; Chattopadhyay, Asoke P

    2010-01-01

    A new anthracene labeled pyridinium amide–urea conjugate 1 has been designed and synthesized. The receptor shows a different fluorometric response with L-N-acetylvaline and L-N-acetylalanine salts in CH3CN in contrast to the other salts of L-N-acetyl α-amino acids and (S)-α-hydroxy acids studied. Upon complexation of the tetrabutylammonium salt of L-N-acetylvaline, the emission of 1 increases accompanied by the formation of a new band at higher wavelength and this characterist...

  6. Anthracene appended pyridinium amide–urea conjugate in selective fluorometric sensing of L-N-acetylvaline salt

    OpenAIRE

    Ghosh, Kumaresh; Sarkar, Tanmay; Chattopadhyay, Asoke P

    2010-01-01

    A new anthracene labeled pyridinium amide–urea conjugate 1 has been designed and synthesized. The receptor shows a different fluorometric response with L-N-acetylvaline and L-N-acetylalanine salts in CH3CN in contrast to the other salts of L-N-acetyl α-amino acids and (S)-α-hydroxy acids studied. Upon complexation of the tetrabutylammonium salt of L-N-acetylvaline, the emission of 1 increases accompanied by the formation of a new band at higher wavelength and this characteristic change distin...

  7. Organocatalyzed One-Step Synthesis of Functionalized N-Alkyl-Pyridinium Salts from Biomass Derived 5-Hydroxymethylfurfural.

    Science.gov (United States)

    Sowmiah, Subbiah; Veiros, Luís F; Esperança, José M S S; Rebelo, Luís P N; Afonso, Carlos A M

    2015-11-01

    An efficient and scalable method has been developed for the synthesis of N-alkylpyridinium salts from biomass derived 5-hydroxymethylfurfural and alkyl amines using a catalytic amount of formic acid. This protocol is also extended to various diamines providing the exclusive formation of mono-N-alkylpyridinium salts. In addition, the mechanism for the formation of pyridinium salts was studied by DFT and using H2(18)O isotope labeled experiments showing no incorporation of (18)O in the product. PMID:26493742

  8. Chloride, bromide and iodide scintillators with europium

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. A new convenient access to highly functionalized ()-2-arylvinyl bromides

    Indian Academy of Sciences (India)

    Yubo Jiang; Chunxiang Kuang

    2009-11-01

    Highly functionalized ()-2-arylvinyl bromides were prepared in high yields through a new convenient access by acylation of ()-4-(2-bromovinyl)phenol with fatty and aromatic acids at room temperature using dicyclohexyl carbodiimide (DCC) and dimethylaminopyridine (DMAP).

  10. Bromide space, total body water, and sick cell syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Schober, O.; Hundeshagen, H.; Lehr, L.

    1982-01-01

    Displacements of the bromide space (Br-82-C, as a marker for the extracellular fluid compartment) are caused by an enhanced anatomical space and/or increased permeability of cells to bromide. The ratio Br-82-C: total body water (TBW) was evaluated to be 0.83 +- 0.17 in critically ill patients (n = 38) compared with the normal value of 0.46 +- 0.04 (n = 10). Because of normal TBW in critically ill patients (TBW = 505 +- 68 ml/kg), an increased bromide penetration into cells seems to be responsible for the enlarged ratio Br-82-C: TBW. Taking into consideration measurements in patients with malabsorption (Br-82-C: TBW = 0.56 +- 0.13; n = 13) and carcinoma of the rectum and colon (Br-82-C: TBW = 0.66 +- 0.24; n = 18) we think that the bromide space is a good measurement of the effective extracellular water.

  11. (1-Butyl-4-methyl-pyridinium)[Cu(SCN)2]: a coordination polymer and ionic liquid.

    Science.gov (United States)

    Spielberg, Eike T; Edengeiser, Eugen; Mallick, Bert; Havenith, Martina; Mudring, Anja-Verena

    2014-04-25

    The compound (C4C1py)[Cu(SCN)2], (C4C1py = 1-Butyl-4-methyl-pyridinium), which can be obtained from CuSCN and the ionic liquid (C4C1py)(SCN), turns out to be a new organic-inorganic hybrid material as it qualifies both, as a coordination polymer and an ionic liquid. It features linked [Cu(SCN)2](-) units, in which the thiocyanates bridge the copper ions in a μ1,3-fashion. The resulting one-dimensional chains run along the a axis, separated by the C4C1py counterions. Powder X-ray diffraction not only confirms the single-crystal X-ray structure solution but proves the reformation of the coordination polymer from an isotropic melt. However, the materials shows a complex thermal behavior often encountered for ionic liquids such as a strong tendency to form a supercooled melt. At a relatively high cooling rate, glass formation is observed. When heating this melt in differential scanning calorimetry (DSC) and temperature-dependent polarizing optical microscopy (POM), investigations reveal the existence of a less thermodynamically stable crystalline polymorph. Raman measurements conducted at 10 and 100 °C point towards the formation of polyanionic chain fragments in the melt. Solid-state UV/Vis spectroscopy shows a broad absorption band around 18,870 cm(-1) (530 nm) and another strong one below 20,000 cm(-1) (<500 nm). The latter is attributed to the d(Cu(I))→π*(SCN)-MLCT (metal-to-ligand charge transfer) transition within the coordination polymer yielding an energy gap of 2.4 eV. At room temperature and upon irradiation with UV light, the material shows a weak fluorescence band at 15,870 cm(-1) (630 nm) with a quantum efficiency of 0.90(2) % and a lifetime of 131(2) ns. Upon lowering the temperature, the luminescence intensity strongly increases. Simultaneously, the band around 450 nm in the excitation spectrum decreases. PMID:24644064

  12. Effects of ipratropium bromide and fenoterol aerosols in pulmonary emphysema.

    OpenAIRE

    Hughes, J A; Tobin, M. J.; Bellamy, D; Hutchison, D. C.

    1982-01-01

    In patients with radiological evidence of pulmonary emphysema the bronchodilator drugs fenoterol and ipratropium bromide produced a considerable increase in vital capacity and reduction in residual volume. The response to fenoterol was virtually complete 15 minutes after administration, but after ipratropium bromide vital capacity was still increasing at 60 minutes. The change in vital capacity was slightly greater with a combination of the two drugs than with either used alone. Changes in FE...

  13. Quantum Chemistry Study on Dissociation of Oxalyl Bromide

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The multi-bond dissociation dynamics of oxalyl bromide ((BrCO)2) has been investigated by DFT and CIS calculations. Upon the results, conclusion could be drawn that dissociation of C-Br bond of oxalyl bromide at the ground state (S0) is of barrierless. After the absorption of a photon, (BrCO)2 is excited to the first excited state and one of its C-Br bonds is broken to yield dissociate.

  14. Assessment of Ethidium bromide and Ethidium monoazide bromide removal from aqueous matrices by adsorption on cupric oxide nanoparticles.

    Science.gov (United States)

    Fakhri, Ali

    2014-06-01

    The present study was undertaken to develop an effective adsorbent and to study the adsorption of Ethidium bromide and Ethidium monoazide bromide from aqueous solution using the CuO nanoparticles. The characteristics of CuO nanoparticles were determined and found to have a surface area 89.59m(2)/g. Operational parameters such as pH, contact time and adsorbent concentration, initial concentration and temperature were also studied. The amount of removal increases with the increase in pH from one to seven and reaches the maximum when the pH is nine. Adsorption data fitted well with the Langmuir, Freundlich and Florry-Huggins models. The results show that the best fit was achieved with the Langmuir isotherm equation with maximum adsorption capacities of 0.868 and 0.662mg/g for Ethidium bromide and Ethidium monoazide bromide, respectively. The adsorption process was found to follow pseudo-second-order kinetics. The calculated thermodynamic parameters, namely ΔG, ΔH and ΔS showed that adsorption of Ethidium bromide and Ethidium monoazide bromide was spontaneous and endothermic under examined conditions. PMID:24630576

  15. Molecular recognition of amino acids with some fluorescent ditopic pyrylium- and pyridinium-based crown ether receptors

    Science.gov (United States)

    Moghimi, A.; Maddah, B.; Yari, A.; Shamsipur, M.; Boostani, M.; Fall Rastegar, M.; Ghaderi, A. R.

    2005-10-01

    The molecular recognition of L-amino acids such as asparagine, glutamine, lysine and arginine with some crownpyryliums, CP's, and a crownpyridinium compound, as receptors, were examined in methanol. 1H NMR spectroscopy was used to examine the structural stability of the receptors in the presence of the amino acids. The fluorimetric titration of the receptors by specified amino acids, other than arginine, was followed within a few minutes and the stoichiometry and stability of the resulting amino acid complexes were evaluated. The data analysis clearly demonstrated the critical role of the terminal amino group to carboxylic acid distance of amino acids for their proper fixation on the receptor molecules. Ion pairing for the two oppositely charged carboxylate anion and pyrylium (or pyridinium) cation, as well as the hydrogen bonding between crown ethers' oxygens and ammonium hydrogens are expected as the main interaction sources in the host-guest complexations.

  16. Electrophysiological study of intravenous pinaverium bromide in cardiology.

    Science.gov (United States)

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

    1988-01-01

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

  17. 5,6-Dimethoxybenzofuran-3-one Derivatives: a Novel Series of Dual Acetylcholinesterase/Butyrylcholinesterase Inhibitors Bearing Benzyl Pyridinium Moiety

    Directory of Open Access Journals (Sweden)

    Mohammad Abdollahi

    2013-02-01

    Full Text Available Several studies have been focused on design and synthesis of multi-target anti Alzheimer compounds. Utilizing of the dual Acetylcholinesterase/Butyrylcholinesterase inhibitors has gained more interest to treat the Alzheimer’s disease. As a part of a research program to find a novel drug for treating Alzheimer disease, we have previously reported 6-alkoxybenzofuranone derivatives as potent acetylcholinesterase inhibitors. In continuation of our work, we would like to report the synthesis of 5,6-dimethoxy benzofuranone derivatives bearing a benzyl pyridinium moiety as dual Acetylcholinesterase/Butyrylcholinesterase inhibitors.MethodsThe synthesis of target compounds was carried out using a conventional method. Bayer-Villiger oxidation of 3,4-dimethoxybenzaldehyde furnished 3,4-dimethoxyphenol. The reaction of 3,4-dimethoxyphenol with chloroacetonitrile followed by treatment with HCl solution and then ring closure yielded the 5,6-dimethoxy benzofuranone. Condensation of the later compound with pyridine-4-carboxaldehyde and subsequent reaction with different benzyl halides afforded target compounds. The biological activity was measured using standard Ellman’s method. Docking studies were performed to get better insight into interaction of compounds with receptor.ResultsThe in vitro anti acetylcholinesterase/butyrylcholinesterase activity of compounds revealed that, all of the target compounds have good inhibitory activity against both Acetylcholinesterase/Butyrylcholinesterase enzymes in which compound 5b (IC50 = 52 ± 6.38nM was the most active compound against acetylcholinesterase. The same binding mode and interactions were observed for the reference drug donepezil and compound 5b in docking study.ConclusionsIn this study, we presented a new series of benzofuranone-based derivatives having pyridinium moiety as potent dual acting Acetylcholinesterase/Butyrylcholinesterase inhibitors.

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

    Science.gov (United States)

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

    2013-02-15

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

  19. Glycosylation with Disarmed Glycosyl Bromides Promoted by Iodonium Ions

    DEFF Research Database (Denmark)

    Lanz, Gyrithe; Madsen, Robert

    2016-01-01

    Iodonium ions have been developed for activating glycosyl bromides in the coupling to glycosyl acceptors. The iodonium ions are generated from N-iodosuccinimide and a protic acid such as camphorsulfonic acid or triflic acid, where the latter gives the most reactive promoter system. The couplings...... occur with the release of iodine monobromide, and the best results are obtained with benzoylated glycosyl donors and acceptors. In this way, disarmed glycosyl bromides can serve as glycosyl donors without the use of heavy-metal salts....

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

    Science.gov (United States)

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

    1985-08-01

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

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

    Science.gov (United States)

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

    1983-01-01

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

  2. (E)-4-[2-(4-Eth­oxy­phen­yl)ethen­yl]-1-methyl­pyridinium naphthalene-2-sulfonate

    OpenAIRE

    Balachandar, R. K.; S. Kalainathan; P. G. Aravindan; Eappen, Shibu M.; Podder, Jiban

    2013-01-01

    In the title salt, C16H18NO+·C10H7O3S−, the substituents attached to the central C=C bond adopt a trans conformation and the benzene and pyridinium rings are nearly coplanar, making a dihedral angle of 6.01 (9)°. The crystal structure features weak C—H⋯O hydrogen bonds and C—H⋯π inter­actions .

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    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. Preozonation of bromide-bearing source water in south China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effectiveness of preozonation was evaluated on treating a bromide-bearing dam source water in south China through batch-scale experiments. Preozonation at ozone doses of 0.5-1.0 mg/L (at ozone consumption base) enhanced total organic carbon(TOC) removal through coagulation, and resulted in an almost linear reduction of ultraviolet absorbance at 254 nm (UV254). The removals of TOC (after coagulation) and UV254 at the ozone dose of 1.0 mg/L were 36% and 70%, respectively. Preozonation at an ozone dose between 0.5 and 1.0 mg/L resulted in the removal of disinfection byproducts formation potential (DBFP) including trihalomethane formation potential (THMFP) and haloacetic acid formation potential (HAAFP) for about 50%. The removals of THMFP and HAAFP decreased with the further increase of ozone dose. Ozonation of bromide-bearing water (bromide concentration,34 μg/L) produced a bromate concentration under the detection limit(2 μg/L) at ozone doses < 1.5 mg/L. However, bromate >10 μg/L could be produced when the bromide concentration was increased to 96 μg/L.

  6. 7 CFR 305.6 - Methyl bromide fumigation treatment schedules.

    Science.gov (United States)

    2010-01-01

    ... to air temperature within the chamber. Fruit taken from a cooling room may have to be prewarmed... pure, type “Q” (for quarantine use only) methyl bromide per 1,000 cubic feet of chamber space. Dosage.... Water temperature in the volatilizer must never fall below 65.6 °C (150 °F) at any time during...

  7. Residues resulting from fumigation of food commodities with methyl bromide

    International Nuclear Information System (INIS)

    An investigation was undertaken to determine the nature and significance of residues remaining in methyl bromide-fumigated commodities using radiotracer techniques (14C-methyl bromide). Experiments with corn showed that the germ part of the kernel contained nearly half of the total 14C-residue remaining in the seed. Also preliminary tests with granny smith apples revealed that considerable residue may remain in seeds of treated apples with less in skin and the least in the fleshy pulp. In fumigated corn, fractionation revealed that radioactive residues were distributed throughout albumins, globulins, Zein 1, Zein 2 and glutelin with a large part in the aqueous extract (amino acids). Further investigation emphasized the characterization of volatile substances resulting from alkali treatment. It was found that methyl bromide readily methylated methionine and this constitutes a major site of methylation. A component of the volatile fraction was dimethyl sulfoxide, probably a product of oxidation of dimethyl sulphide. Work is in progress to determine whether methyl bromide will methylate purine and pyrimidine components. (author)

  8. Methyl bromide phase out could affect future reforestation efforts

    Science.gov (United States)

    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...

  9. Een ionchromatografische methode voor de simultane bepaling van nitriet, bromide en sulfiet in water

    NARCIS (Netherlands)

    Beld WA van den; Cleven RFMJ; LAC

    1996-01-01

    Betreft resultaten van een onderzoek naar het ontwikkelen van een geautomatiseerde ionchromatografische methode voor de bepaling van nitriet, bromide en sulfiet. Het onderzoek heeft geresulteerd in een betrouwbare, selectieve en gevoelige methode voor de simultane bepaling van nitriet, bromide e

  10. Association of defects in lead chloride and lead bromide: Ionic conductivity and dielectric loss measurements

    NARCIS (Netherlands)

    Brom, W.E. van den; Schoonman, J.; Wit, J.H.W. de

    1972-01-01

    The ionic conductivity data of pure and doped lead bromide without associated defects are used in order to explain the anomalous conductivity behaviour of copper (I) bromide and lead oxide-doped lead-bromide crystals. In these crystals precipitated dopant and associated defects are present. The asso

  11. Detection of lipopolysaccharides by ethidium bromide staining after sodium dodecyl sulfate-polyacrylamide gel electrophoresis.

    OpenAIRE

    Kido, N; Ohta, M; Kato, N

    1990-01-01

    A rapid and easy method for staining lipopolysaccharides with ethidium bromide is described. Lipopolysaccharides could be visualized by ethidium bromide with almost the same sensitivity as found with the silver-staining method in less than 30 min. The ethidium bromide-staining method was particularly suitable for staining lipopolysaccharides possessing acidic O-specific polysaccharides, which were poorly visualized by silver staining.

  12. 40 CFR 180.519 - Bromide ion and residual bromine; tolerances for residues.

    Science.gov (United States)

    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...

  13. The study of The study of the influence of temperature on surfactants – polyethylene glycol layers The study of the influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interface liquid-gas interfacethe influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interfaceThe study of the influence of temperature on surfactants – polyethylene glycol layers on liquid-gas interface

    Directory of Open Access Journals (Sweden)

    Seryk Boloshaan

    2015-03-01

    Full Text Available The surface tension of compositions consisting of nonionic polyethylene glycol and surface active substances of different nature and influence of temperatures on properties of their adsorption layers were studied. To be taken into account the basics of classical chemical thermodynamics and colloidal chemistry, the thermodynamic parameters were determined for the adsorption of glycol, cetyl pyridinium bromide, Tween- 80 and sodium dodecyl sulfate. Adsorption speed was valuated By Kinetic curves of a liquid /gas interfaces. As a surfactants were taken the anionic surfactant – sodium dodecylsulphate, cationic surfactant cetylpyridinium bromide and nonionic Tween-80. The reason of using nonionic polyethyleneglycol as polymer is that the polymer is not toxic, biodegradable and it has no harm to the human body. That is why they are largely used in food industry, pharmaceutics, cosmetics and household chemical products.

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

    Science.gov (United States)

    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

  15. A comparison of the effect of intranasal desmopressin and intramuscular hyoscine N-butyl bromide combination with intramuscular hyoscine N-butyl bromide alone in acute renal colic

    OpenAIRE

    Abdol-Reza Kheirollahi; Mohammad Tehrani; Mohammad Bashashati

    2010-01-01

    Background: Patients with acute renal colic usually require immediate diagnosis and treatment. In this clinical trial analgesic effect of hyoscine N-butyl bromide and desmopressin combination in comparison with hyoscine N-butyl bromide alone in patients with acute renal colic induced by urinary stones was assessed. Methods: The study included 114 patients randomly allocated in two groups (A and B). Patients in group A received 20 mg intramuscular hyoscine N-butyl bromide at admission tim...

  16. Mesomeric betaine chemistry in solution: Solvent effect on the structure and spectra of uracilyl-pyridinium betaine

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, A., E-mail: schmidt@ioc.tu-clausthal.de [Institute of Organic Chemistry, Clausthal University of Technology, Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld (Germany); Lindner, A.S. [Institute of Organic Chemistry, Clausthal University of Technology, Leibnizstrasse 6, D-38678 Clausthal-Zellerfeld (Germany); Casado, J.; Lopez Navarrete, J.T. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Malaga, Malaga 29071 (Spain); Ramirez, F.J., E-mail: ramirez@uma.es [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Malaga, Malaga 29071 (Spain)

    2010-05-25

    Graphical abstract: Vibrational Raman, UV-vis and fluorescence spectroscopies, supported by DFT calculations, demonstrate that a polar environment quinoidizes the cationic part and aromatizes the anionic moiety of cross-conjugated mesomeric betaines. - Abstract: The presence of positive and negative delocalized charges in a heterocyclic conjugated system gives rise to an interesting class of molecules known as mesomeric betaines. These can be conveniently represented by dipolar canonical formulae. Among them, cross-conjugation appears when the charges are placed in separated parts of the common {pi}-electron system. This fact makes cross-conjugated mesomeric betaines (CCMB) suitable systems to study intramolecular electron transfer processes. In this paper, we studied Raman and electronic spectra of an uracilyl-pyridinium CCMB in solution. Vibrational results demonstrated that the presence of a polar environment quinoidizes the cationic part and aromatizes the anionic moiety of this molecule, which gave us useful information to propose the more relevant mesomeric structures of this molecule in solution. Raman spectroscopy was able to account for cross-conjugation by characterizing conjugational-sensitive bands. The effect of the solvent polarity was studied by electronic spectroscopy, allowing us to establish spectroscopy-structure relationships.

  17. Aluminium Electroplating on Steel from a Fused Bromide Electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. [2,6-Bis(dimethylaminomethylphenyl]selenium bromide monohydrate

    Directory of Open Access Journals (Sweden)

    Richard A. Varga

    2010-04-01

    Full Text Available In the title hydrated molecular salt, C12H19N2Se+·Br−·H2O, the two independent bromide anions lie on a twofold rotation axis. Strong intramolecular N→Se interactions [2.185 (3 and 2.181 (3 Å] are established by both N atoms of the organic group in the cation, in trans positions to each other, with an N—Se—N angle of 161.6 (1°, resulting in a T-shaped (C,N,N′Se core. In the crystal, dimeric associations are formed by Br...Se [3.662 (2 Å] and Br...H interactions [2.56 (6 and 2.63 (7 Å] involving two bromide anions, two cations and two water molecules.

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

    Science.gov (United States)

    Ando, Yasuhiro; Tomita, Yuki; Haba, Yusuke

    2008-01-01

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

  20. High-speed Laser Micromachining with Copper Bromide Laser

    CERN Document Server

    Balchev, I I; Minkovski, N I; Sabotinov, N V; Balchev, Ivaylo I.; Kostadinov, Ivan K.; Minkovski, Nikolai I.; Sabotinov, Nikola V.

    2006-01-01

    The application of the copper bromide (CuBr) laser as an attractive tool in the micro-machining of different materials has been demonstrated. High-quality drilling by trepanning and precision cutting was established on several materials with a negligible heat-affected zone (HAZ). That good performance was a result of the combination of high power visible radiation, short pulses, and close to the diffraction-limited laser beam quality with high-speed galvo scanner beam steering.

  1. Criticality in aqueous solutions of 3-methylpyridine and sodium bromide.

    Science.gov (United States)

    Kostko, A F; Anisimov, M A; Sengers, J V

    2004-08-01

    We address a controversial issue regarding the nature of critical behavior in ternary electrolyte solutions of water, 3-methylpyridine, and sodium bromide. Earlier light-scattering studies showed an anomalous critical behavior in this system that was attributed to the formation of a microheterogeneous phase associated with ion-molecule clustering [M.A. Anisimov, J. Jacob, A. Kumar, V.A. Agayan, and J. V. Sengers, Phys. Rev. Lett. 85, 2336 (2000)

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

    Science.gov (United States)

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

    2003-01-01

    Heat and bromide were compared as tracers for examining stream/ground water exchanges along the middle reaches of the Santa Clara River, California, during a 10-hour surface water sodium bromide injection test. Three cross sections that comprise six shallow (sodium bromide injection test. Vertical, one-dimensional simulations of bromide concentrations in the sediments yielded a good match to the observed bromide concentrations, without adjustment of any model parameters except solute dispersivities. This indicates that, for the spatial and temporal scales examined on the Santa Clara River, the use of heat and bromide as tracers provide comparable information with respect to apparent hydraulic conductivities and fluxes for sediments near streams. In other settings, caution should be used due to differences in the nature of conservative (bromide) versus nonconservative (heat) tracers, particularly when preferential flowpaths are present.

  3. Use of 82Br and 131I radionuclides in studies of goitrogenic effects of exogenous bromide

    International Nuclear Information System (INIS)

    The interference of excessive bromide intake with iodine metabolism in the rat was studied using 82Br and 131I radionuclides. Mainly lactating rat dams and their pups were used, in addition to adult male rats, in the present studies. Particularly, the influence of high bromide intake in lactating rat dams on the transfer of iodine and bromide to suckling young through breast milk was evaluated. The induction of hypothyroid status in the pups by high bromide intake in the mothers was proved unambiguously. Excessive bromide in lactating rat dams caused a marked decrease in plasma levels of thyroid hormones both, in the mothers and in their sucklings. The effects of an enhanced bromide intake on the thyroid function in relation to iodine status in the animals were also followed. Marked goitrogenic and thyrotoxic effects of excessive bromide in adult rats were significantly enhanced under the conditions of simultaneous iodine deficiency in the experimental animals. (author)

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

    Science.gov (United States)

    Soifer, L; Varela, E; Olmos, J

    1992-01-01

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

  5. Structural, vibrational and theoretical studies of L-histidine bromide

    Science.gov (United States)

    Ahmed, A. Ben; Feki, H.; Abid, Y.; Boughzala, H.; Mlayah, A.

    2008-10-01

    This paper presents the results of our calculations of the geometric parameters, vibrational spectra and hyperpolarizability of a non linear optical material, L-histidine bromide. Due to the lack of sufficiently precise information on the geometric structure available in literature, theoretical calculations were preceded by re-determination of the crystal X-ray structure. Single crystals of L-histidine bromide have been grown by slow evaporation of an aqueous solution at room temperature. The compound crystallizes in the non-Centro symmetric space group P2 12 12 1 of the orthorhombic system. Raman spectra have been recorded in the range [200-3500 cm -1]. All observed vibrational bands have been discussed and assigned to normal mode or to combinations and overtones on the basis of our calculations. The optimized geometric bond lengths and bond angles obtained by using HF and DFT (B3LYP and BLYP) show good agreement with the experimental data. Comparison between the measured and the calculated vibrational frequencies indicate that B3LYP is superior to the scaled HF approach for molecular vibrational problems. To investigate microscopic second order non linear optical properties of L-histidine bromide, the electric dipole μ, the polarizability α and the hyperpolarizability β were computed using DFT//B3LYP/6-31G(d) method. According to our calculations, the title compound exhibits non-zero β value revealing microscopic second order NLO behaviour.

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

    Science.gov (United States)

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

    1998-05-01

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

  7. Synthesis and Crystal Structure of [ 1- (4' -fluorobenzyl )pyridinium ]2 [ Ni (dto)2 ] Complex(dto2- = dithiooxalate dianion)%配合物[1-(4'-fluorobenzyl)pyridinium]2[Ni(dto)2](dto2-=dithiooxalate dianion)的合成及晶体结构

    Institute of Scientific and Technical Information of China (English)

    刘玲; 谢景力; 任小明; 孟庆金

    2002-01-01

    The complex [ 1- (4'-fluorobenzyl) pyridinium ] 2 [ Ni (dto) 2 ] (dto2 - means dithiooxalate dianion) has been pre-pared by reaction of Na2[Ni(S2C2O2)2] and the 1-(4'-fluorobenzyl) pyridinium chloride salt. The crystallographicdata for the title complex: triclinic P1, a =8. 5698(8) A, b =9. 3461(9) A, c = 10. 5361(10) A, α =67. 177(2)°, β =67.398(2)°, γ =79. 611(2)°, V=717.59(12) A3, Z= 1. The [Ni(dto) 2] 2- anion with the Ni atomO is clearly observed. The nature and size of cation seems to play an important factor in the type of intermolecularinteractions as well as the crystal packing in this kind of complexes.

  8. Solid miscibility of common-anion lithium and sodium halides. Experimental determination of the region of demixing in lithium bromide + sodium bromide

    NARCIS (Netherlands)

    Oonk, H.A.J.; Wijk, H.J. van; Doornhof, D.

    1984-01-01

    The region of demixing of solid lithium bromide + sodium bromide mixtures has been measured by X-ray diffraction. The critical temperature of mixing corresponding to a thermodynamic fit of the experimental data is 513 K. Estimates are given of the regions of demixing in solid lithium chloride + sodi

  9. An Eco-Friendly Ultrasound-Assisted Synthesis of Novel Fluorinated Pyridinium Salts-Based Hydrazones and Antimicrobial and Antitumor Screening.

    Science.gov (United States)

    Rezki, Nadjet; Al-Sodies, Salsabeel A; Aouad, Mohamed R; Bardaweel, Sanaa; Messali, Mouslim; El Ashry, El Sayed H

    2016-01-01

    The present work reports an efficient synthesis of fluorinated pyridinium salts-based hydrazones under both conventional and eco-friendly ultrasound procedures. The synthetic approach first involves the preparation of halogenated pyridinium salts through the condensation of isonicotinic acid hydrazide (1) with p-fluorobenzaldehyde (2) followed by the nucleophilic alkylation of the resulting N-(4-fluorobenzylidene)isonicotinohydrazide (3) with a different alkyl iodide. The iodide counteranion of 5-10 was subjected to an anion exchange metathesis reaction in the presence of an excess of the appropriate metal salts to afford a new series of fluorinated pyridinium salts tethering a hydrazone linkage 11-40. Ultrasound irradiation led to higher yields in considerably less time than the conventional methods. The newly synthesized ILs were well-characterized with FT-IR, ¹H NMR, (13)C NMR, (11)B, (19)F, (31)P and mass spectral analyses. The ILs were also screened for their antimicrobial and antitumor activities. Within the series, the salts tethering fluorinated counter anions 11-13, 21-23, 31-33 and 36-38 were found to be more potent against all bacterial and fungal strains at MIC 4-8 µg/mL. The in vitro antiproliferative activity was also investigated against four tumor cell lines (human ductal breast epithelial tumor T47D, human breast adenocarcinoma MCF-7, human epithelial carcinoma HeLa and human epithelial colorectal adenocarcinoma Caco-2) using the MTT assay, which revealed that promising antitumor activity was exhibited by compounds 5, 12 and 14. PMID:27213367

  10. An Eco-Friendly Ultrasound-Assisted Synthesis of Novel Fluorinated Pyridinium Salts-Based Hydrazones and Antimicrobial and Antitumor Screening

    Directory of Open Access Journals (Sweden)

    Nadjet Rezki

    2016-05-01

    Full Text Available The present work reports an efficient synthesis of fluorinated pyridinium salts-based hydrazones under both conventional and eco-friendly ultrasound procedures. The synthetic approach first involves the preparation of halogenated pyridinium salts through the condensation of isonicotinic acid hydrazide (1 with p-fluorobenzaldehyde (2 followed by the nucleophilic alkylation of the resulting N-(4-fluorobenzylideneisonicotinohydrazide (3 with a different alkyl iodide. The iodide counteranion of 5–10 was subjected to an anion exchange metathesis reaction in the presence of an excess of the appropriate metal salts to afford a new series of fluorinated pyridinium salts tethering a hydrazone linkage 11–40. Ultrasound irradiation led to higher yields in considerably less time than the conventional methods. The newly synthesized ILs were well-characterized with FT-IR, 1H NMR, 13C NMR, 11B, 19F, 31P and mass spectral analyses. The ILs were also screened for their antimicrobial and antitumor activities. Within the series, the salts tethering fluorinated counter anions 11–13, 21–23, 31–33 and 36–38 were found to be more potent against all bacterial and fungal strains at MIC 4–8 µg/mL. The in vitro antiproliferative activity was also investigated against four tumor cell lines (human ductal breast epithelial tumor T47D, human breast adenocarcinoma MCF-7, human epithelial carcinoma HeLa and human epithelial colorectal adenocarcinoma Caco-2 using the MTT assay, which revealed that promising antitumor activity was exhibited by compounds 5, 12 and 14.

  11. 表面活性剂对十六烷基羟乙基纤维素溶液黏度的影响%Effects of surfactant on viscosity of cetyl hydroxyethylcellulose solution

    Institute of Scientific and Technical Information of China (English)

    徐强; 杨成

    2009-01-01

    Effects of surfactant on viscosity of cetyl hydroxyethylcellulose (CHEC) solution were investigated by rheometer. Experimental results indicated that the viscosity of CHEC solution increases with increasing of the surfactant concentration, and after a maximum value, then decreases with further addition of the surfactant. The effect of temperature on the viscosity of surfactant and CHEC solution depends upon the formation of surfactant/CHEC complex. The effect of variety of surfactant on the hydrophobic associate interaction of surfactant and CHEC is in the order of AES >6501 > CAB.%通过流变仪研究了几种表面活性剂对十六烷基羟乙基纤维素(CHEC)溶液黏度的影响.结果表明,CHEC溶液的黏度随表面活性剂质量分数的增加先升高,达到最大值后逐渐下降;温度对表面活性剂和CHEC混合溶液黏度的影响与表面活性剂和CHEC形成的复合物有关;表面活性剂与CHEC的疏水缔合作用强弱顺序是AES>6501>CAB.

  12. Interaction between gaseous ozone and crystalline potassium bromide

    Science.gov (United States)

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

    2016-07-01

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

  13. Suicide by intravenous injection of rocuronium-bromide: Case report

    Directory of Open Access Journals (Sweden)

    Nikolić Slobodan

    2005-01-01

    Full Text Available Suicides by intravenous injection of an overdose of medicaments are uncommon. In this paper, we present the case of a suicide by rocuronium-bromide injection in combination with an oral overdose of metoprolol. Unfortunately, in Belgrade, there is no toxicological laboratory capable of detecting rocuronium. The interpretation of autopsy and toxicological data in this case was made difficult due to the extreme putrefaction of the body of the deceased. So, by forensic investigation, the case was solved indirectly, through circumstantial evidence: an empty ampoule of rocuronium found near the body, as well as a plastic syringe and cloth-bandage found in the left hand of the deceased.

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

    OpenAIRE

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

    1996-01-01

    The oceans play an important role in the geochemical cycle of methyl bromide (CH_3Br), the major carrier of O_3-destroying bromine to the stratosphere. The quantity of CH_3Br 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 CH_3Br is consumed in situ by hydrolysis or reaction with chloride. The size of the fraction which escapes to the atmo...

  15. Enzyme activities in agricultural soils fumigated with methyl bromide alternatives

    OpenAIRE

    Klose, Susanne; Ajwa, H A

    2004-01-01

    Pre-plant fumigation of agricultural soils with a combination of methyl bromide (MeBr) and chloropicrin (CP) to control nematodes, soil-borne pathogens and weeds has been a common practice in strawberry (Fragaria X ananassa Duchesne) production since the 1960s. MeBr will be phased out by 2005, but little is known about the impacts of alternative fumigants on soil microbial processes. We investigated the response of microbial biomass and enzyme activities in soils fumigated over two years with...

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

    Science.gov (United States)

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

    1983-01-01

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

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

    Science.gov (United States)

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

    1985-09-01

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

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

    OpenAIRE

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

    1985-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Steinmetz Sonja

    2012-12-01

    Full Text Available Abstract 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.

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

    Science.gov (United States)

    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

  1. On the direct current electric conductivity and conduction mechanism of some stable disubstituted 4-(4-pyridyl)pyridinium ylides in thin films

    Energy Technology Data Exchange (ETDEWEB)

    Danac, R. [Faculty of Chemistry, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Leontie, L., E-mail: lleontie@uaic.ro [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania); Girtan, M. [Laboratoire LPhiA, Angers University, 2, Bd. Lavoisier, 49045 Angers (France); Prelipceanu, M.; Graur, A. [Faculty of Electrical Engineering and Computer Science, Stefan cel Mare University of Suceava, Str.Universitatii, Nr.13, RO-720229 Suceava (Romania); Carlescu, A.; Rusu, G.I. [Faculty of Physics, Alexandru Ioan Cuza University of Iasi, Bulevardul Carol I, Nr. 11, 700506 Iasi (Romania)

    2014-04-01

    Temperature-dependent d.c. electric conductivity of some recently synthesized organic compounds, stable disubstituted 4-(4-pyridyl)pyridinium ylides, is studied. Thin-film samples (d = 0.100.80 μm) spin-coated from dimethylformamide solutions onto glass substrates have been used. Organic films with reproducible electron transport properties can be obtained if, after deposition, they are submitted to a heat treatment within temperature range of 297 − 527 K. The studied polycrystalline compounds exhibit typical n-type semiconductor behavior. The activation energy of the electric conduction ranges between 0.59 and 0.94 eV. Some correlations between semiconducting parameters and molecular structure of the organic compounds have been discussed. In the higher temperature range (T > 400 K), the electron transport in examined compounds can be interpreted in terms of the band gap representation model, while in the lower temperature range, the Mott's variable-range hopping conduction model was found to be appropriate. Some of the investigated compounds hold promise for thermistor applications. - Highlights: • 4-(4-Pyridyl)pyridinium ylides in thin films behave as n-type semiconductors. • The electron transfer is favored by extended conjugation and packing capacity. • The band gap representation is suitable in the higher temperature range. • The Mott's variable-range hopping model may be used in the lower temperature range.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Copper, W.J. (Florida International Univ., Miami (United States)); Amy, G.L. (Univ. of Arizona, Tucson (United States)); Moore, C.A.; Zika, R.G. (Univ. of Miami, FL (United States))

    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.

  4. Synthesis and Characterization of Mercuric Bromide-Phenothiazine Complexes

    Directory of Open Access Journals (Sweden)

    Vidisha A. Alwani

    2014-12-01

    Full Text Available N-alkylphenothiazines (NAPTZs are biologically active heterocyclic compounds that find extensive applications in the field of medicine. In the pharmaceutical industry, they are used as psychotherapeutic, antiemetic, and antihistaminic drugs. In this study, complexation reactions of mercuric bromide with NAPTZs as principal ligands have been investigated in MeOH medium. Five mercuric bromide complexes of the NAPTZ ligands namely, chlorpromazine hydrochloride (CP.HCl, promethazine hydrochloride (PM.HCl, ethopropazine hydrochloride (EP.HCl, trifluoperazine dihydrochloride (TF.2HCl and thioridazine hydrochloride (TR.HCl have been synthesized. These complexes were subjected to elemental analysis, solubility, molar conductance and magnetic susceptibility, U.V-Vis, I.R, and NMR spectroscopy. The molecular formulations of the complexes have been found to be: [HgBr2(CP2].4H2O; [HgBr2(PM2].2H2O; [HgBr2(EP2]; [HgBr2(TF2].2H2O and [HgBr2(TR2]. Tentative molecular structures have been proposed and presented.

  5. Modeling water/lithium bromide absorption chillers in ASPEN Plus

    International Nuclear Information System (INIS)

    Highlights: → Single- and double-effect water/lithium bromide absorption chiller designs are numerically modeled using ASPEN. → The modeling procedure is described and the results are compared to published modeling data to access prediction accuracy. → Predictions for the single- and double-effect designs are within 3% and 5%, respectively of published data for all cycle parameters of interest. → The absorption cycle models presented allow investigation of using absorption chillers for waste heat utilization in the oil and gas industry. -- Abstract: Absorption chillers are a viable option for providing waste heat-powered cooling or refrigeration in oil and gas processing plants, thereby improving energy efficiency. In this paper, single- and double-effect water/lithium bromide absorption chiller designs are numerically modeled using ASPEN. The modeling procedure is described and the results are compared to published modeling data to access prediction accuracy. Predictions for the single- and double-effect designs are within 3% and 5%, respectively of published data for all cycle parameters of interest. The absorption cycle models presented not only allow investigation into the benefits of using absorption chillers for waste heat utilization in the oil and gas industry, but are also generically applicable to a wide range of other applications.

  6. Development of copper bromide laser master oscillator power amplifier system

    Indian Academy of Sciences (India)

    G N Tiwari; R K Mishra; R Khare; S V Nakhe

    2014-02-01

    Development of master oscillator power amplifier (MOPA) system of copper bromide laser (CBL) operating at 110 W average power is reported. The spectral distribution of power at green (510.6 nm) and yellow (578.2 nm) components in the output of a copper bromide laser is studied as a function of operating parameters. The electrical input power was varied from 2.6 to 4.3 kW, the pulse repetition frequency (PRF) was changed from 16 to 19 kHz, and the pressure of the buffer gas (neon) was kept fixed at 20 mbar. When the electrical input power was increased to 4.3 kW from 2.6 kW, the tube-wall temperature also increased to 488°C from 426°C but the ratio of the green to yellow power decreased to 1.53 from 3.73. The ratio of green to yellow power decreased to 1.53 from 1.63 when the PRF of the laser was increased to 19 kHz from 16 kHz. These observations are explained in terms of electron temperature, energy levels of transitions, and voltage and current waveforms across the laser head.

  7. Vapour pressures, densities, and viscosities of the (water + lithium bromide + potassium acetate) system and (water + lithium bromide + sodium lactate) system

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, Antonio de [Department of Chemical Engineering, University of Castilla - La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain); Donate, Marina [Department of Chemical Engineering, University of Castilla - La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain); Rodriguez, Juan F. [Department of Chemical Engineering, University of Castilla - La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain)]. E-mail: juan.rromero@uclm.es

    2006-02-15

    Measurements of thermophysical properties (vapour pressure, density, and viscosity) of the (water + lithium bromide + potassium acetate) system LiBr:CH{sub 3}COOK = 2:1 by mass ratio and the (water + lithium bromide + sodium lactate) system LiBr:CH{sub 3}CH(OH)COONa = 2:1 by mass ratio were measured. The system, a possible new working fluid for absorption heat pump, consists of absorbent (LiBr + CH{sub 3}COOK) or (LiBr + CH{sub 3}CH(OH)COONa) and refrigerant H{sub 2}O. The vapour pressures were measured in the ranges of temperature and absorbent concentration from T = (293.15 to 333.15) K and from mass fraction 0.20 to 0.50, densities and viscosities were measured from T = (293.15 to 323.15) K and from mass fraction 0.20 to 0.40. The experimental data were correlated with an Antoine-type equation. Densities and viscosities were measured in the same range of temperature and absorbent concentration as that of the vapour pressure. Regression equations for densities and viscosities were obtained with a minimum mean square error criterion.

  8. Characterization studies of 1-(4-cyano-2-oxo-1,2-dihydro-1-pyridyl)-3-(4-cyano-1,2-dihydro-1-pyridyl) propane formed from the reaction of hydroxide Ion with 1,3-Bis-(4-cyano pyridinium)propane

    Energy Technology Data Exchange (ETDEWEB)

    Fiori, Simone; Schuquel, Ivania T.A.; Meyer, Emerson; Hioka, Noboru, E-mail: nhioka@uem.br [Departamento de Quimica, Universidade Estadual de Maringa, PR (Brazil); Silva, Idelcio N. da [Fundacao Educacional do Municipio de Assis, Assis, SP (Brazil); Politi, Mario J.; Catalani, Luiz H.; Chaimovich, Hernan [Instituto de Quimica, Universidade de Sao Paulo, SP (Brazil)

    2011-09-15

    The aqueous alkaline reaction of 1,3.bis(4.cyanopyridinium)propane dibromide, a reactant constituted of two pyridinium rings linked by a three.methylene bridge, generates a novel compound, 1-(4-cyano-2-oxo-1,2-dihydro-1-pyridyl)-3-(4-cyano-1,2-dihydro-1-pyridyl) propane. The reaction pathway is attributed to the proximity of the OH. ion inserted between two pyridinium moieties, which occurs only in bis(pyridinium) derivatives connected by short methylene spacers, where charge-conformational effects are important. (author)

  9. 76 FR 7200 - Methyl Bromide; Notice of Receipt of Requests To Voluntarily Amend Registrations To Terminate...

    Science.gov (United States)

    2011-02-09

    ... Professional Products to voluntarily amend methyl bromide product registration 8536-12 to terminate or delete... identity or contact information unless you provide it in the body of your comment. If you send an e- mail... Cardinal Professional Products, and Trical, Inc.) to delete certain uses of methyl bromide...

  10. SYNTHESIS AND CATALYTIC PROPERTIES OF HYDROPHOBICALLY MODIFIED POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES)

    NARCIS (Netherlands)

    YANG, YJ; ENGBERTS, JBFN

    1991-01-01

    A series of hydrophobically modified homo- and copolymers of the poly(alkylmethyldiallylammonium bromide) type has been prepared by free-radical cyclo(co)polymerization of alkylmethyldiallylammonium bromide monomers in aqueous solution. Depending on the length of the alkyl side chain (varied between

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

    Science.gov (United States)

    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...

  12. Determination of micro-amount bromide in uranium trioxide by spectrophotometric method

    International Nuclear Information System (INIS)

    The content of bromide in the production of uranium trioxide is one of the most important control factors, so determining it accurately seems important. When uranium trioxide is dissolved in nitric acid, in the presence of AgNO3 solution, micro-amount bromide can be co- precipitated with AgCl. Bromide can be separated by centrifugation from a large amount of UO22+ and other anions. In the existing of KOH and H2O2, AgCl can be changed into free bromide. By adding ammonium molybdate as catalyst, bromide and excessive KBrO3 can react and produce Br2. In the medium of tert-butanol-ethanol, Br2 can react with basic fuchsine and produce a purple compound which is stable, the bromide content is determined by spectrophotometric method. The results show that it is a highly sensitive method with low detection limit. Its apparent molar absorption coefficient κ' is 1.7 x 104 L/(mol·cm). Its detection limit is 9 μg/L and determination limit is 0.13 mg/L. The linear relationship is in the range of 0.2-1.6 mg/L with a correlation coefficient of 0.997. The relative standard deviation is less than 10% after it is determed six times at the same time. For bromide content of 4.00 and 8.00 μg, the bromide recovery obtained are between 94% and 103%. (authors)

  13. Solvent effects in the reaction between piperazine and benzyl bromide

    Indian Academy of Sciences (India)

    S Ranga Reddy; P Manikyamba

    2007-11-01

    The reaction between piperazine and benzyl bromide was studied conductometrically and the second order rate constants were computed. These rate constants determined in 12 different protic and aprotic solvents indicate that the rate of the reaction is influenced by electrophilicity (), hydrogen bond donor ability () and dipolarity/polarizability (*) of the solvent. The LSER derived from the statistical analysis indicates that the transition state is more solvated than the reactants due to hydrogen bond donation and polarizability of the solvent while the reactant is more solvated than the transition state due to electrophilicity of the solvent. Study of the reaction in methanol, dimethyl formamide mixtures suggests that the rate is maximum when dipolar interactions between the two solvents are maximum.

  14. Mechanism of the Deaquation of Aquopentaaminocobalt(Ⅲ) Bromide

    Institute of Scientific and Technical Information of China (English)

    MA,Li-Dun(马礼敦); CHENG,Guang-Hui(程广辉); WU,Hong-Xiang(吴宏翔); LIN,Han-Yi(林涵毅); SHEN,Xiao-Liang(沈孝良); SHI,Guo-Shun(施国顺)

    2002-01-01

    There are two theories, SN1 and SN2, for the mechanism of the deaquation of aquopentaamincobalt(Ⅲ) bromide (AAC-B).Both of the theories are supported by some experimental and calculated data. But there are not any experiments to determine directly the structure of the intermediates at different reaction time. In this paper the structures of the intermediates at different reaction time in deaquation-anation of AACB were de-termined by extended X-ray absorption fine structure (EXAFS)and the reaction process wes studied by the combination of Xray powder diffraction and EXAFS. It was demonstrated that the deaquation-anation of AACB obeys the SN2 theory.

  15. Design and Fabrication of Externally heated Copper Bromide Laser

    Directory of Open Access Journals (Sweden)

    J.P. Dudeja

    1993-04-01

    Full Text Available An externally-heated, longitudinally-discharged, low-repetition-rate copper bromide laser, was designed and fabricated. The green-coloured wavelength at 5106 A from this laser can be used for underwater ranging and detection of submerged objects. Several new changes in the design of discharge tube, heating technique, buffer-gas-flow sub-system and electrical circuit have been conceived and incorporated advantageously in our system. Various parameters, for example, the type of buffer gas and its flow rate, mixture of gases, temperature of the discharge tube, delay between dissociation and excitation pulses, dissociation and excitation energies, and various resonator configurations are being optimised to get the maximum output power/energy from the laser system.

  16. Xanthine Biosensor Based on Didodecyldimethylammonium Bromide Modified Pyrolytic Graphite Electrode

    Institute of Scientific and Technical Information of China (English)

    TANG,Ji-Lin(唐纪琳); HAN,Xiao-Jun(韩晓军); HUANG,Wei-Min(黄卫民); WANG,Er-Kang(汪尔康)

    2002-01-01

    The vesicle of didodecyldimethylammonium bromide (DDAB)which contained tetrathiafulvalene (TTF) was mixed with xanthine oxidase, and the mixture was cast on the pyrolytic graphite electrode. The lipid films were used to supply a biological environment resembling biomembrane on the surface of the electrode. TTF was used as a mediator because of its high electron-transfer efficiency. A novel xanthine biosensor based on cast DDAB film was developed. The effects of pH and operating potential were explored for optimum analytical performance by using the amperometric method. The response time of the biosensor was less than 10 s. The detection limit of the biosensor was 3.2 × 10-7 mol/L and the liner range was from 4 × 10-7 mol/L to 2.4 × 10-6 mol/L.

  17. Irradiation as an alternative to methyl bromide: the Australian situation

    International Nuclear Information System (INIS)

    International agreement to phase out the fumigant Methyl bromide (MeBr) will have serious implications for pest and disease control in Australia, particularly grain pest control, quarantine usage on fresh horticultural produce and control of soil pathogens or nematodes. Irradiation is a practical alternative but is not currently approved for use in Australia. Other options are available but none of the viable methods except irradiation have the short application time needed for treatment of grams found to be infested during loading at export. This usage is vital, as Australian grain is exported at very high standards of freedom from insects, assured by Government regulatory requirements. Irradiation is contrasted against other alternatives including heat and cold, especially for fresh horticultural produce. (author)

  18. Mechanism of the Deaquation of Aquopentaaminocobalt(Ⅲ)Bromide

    Institute of Scientific and Technical Information of China (English)

    MA,Li-Dun; CHENG,Guang-Hui; 等

    2002-01-01

    There are two theories,SN1 and SN2, for the mechanism of the deaquation of aquopentaamincobalt(Ⅲ) bromide(AAC-B). Both of the theories are supported by some experimental and calculated data. But there are not any experiments to determine directly the structure of the intermediates at dififferent reaction time.In this paper the structures of the intermediates at different reaction time in deaquation-anation of AACB were determined by extended X-ray absorption fine structure (EXAFS) and the reaction process was studied by the combination of X-ray powder diffraction and EXAFS.It was demonstrated that the deaquation-anation of AACB obeys the SN2 theory.

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

    Science.gov (United States)

    Christen, M O

    1990-01-01

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

  20. 以溴代十六烷基吡啶为增敏剂催化动力学光度法测定痕量钴(Ⅱ)%Catalytic Spectrophotometric Method for Determination of Trace Cobalt(Ⅱ) with Cetyl Pyridine Bromide as Sensitizet

    Institute of Scientific and Technical Information of China (English)

    王晓菊; 郭飞君; 盖永胜

    2008-01-01

    在增敏剂溴代十六烷基吡啶和活化剂氨基乙酸存在下,钴对高碘酸钾氧化酸性铬兰K的反应具有催化作用,据此建立了一种测定痕量钴(Ⅱ)的新方法.考察该反应的最佳条件,测定反应动力学参数.在表面活性剂和活化剂存在下,本法灵敏度提高12倍.线性范围为0~100 μg/L,检出限为9.06×10-7g/L.此法用于茶叶、VB12等样品中钴的测定,结果令人满意.

  1. Enhanced degradation of carbon tetrachloride by surfactant-modified zero-valent iron

    Institute of Scientific and Technical Information of China (English)

    MENG Ya-feng; GUAN Bao-hong; WU Zhong-biao; WANG Da-hui

    2006-01-01

    Sorption of carbon tetrachloride (CT) by zero-valent iron (ZVI) is the rate-limiting step in the degradation of CT, so the sorption capacity of ZVI is of great importance. This experiment was aimed at enhancing the sorption of CT by ZVI and the degradation rate of CT by modification of surfactants. This study showed that ZVI modified by cationic surfactants has favorable synergistic effect on the degradation of CT. The CT degradation rate of ZVI modified by cetyl pyridinium bromide (CPB) was higher than that of the unmodified ZVI by 130%, and the CT degradation rate of ZVI modified by cetyl trimethyl ammonium bromide (CTAB) was higher than that of the unmodified ZVI by 81%. This study also showed that the best degradation effect is obtained at the near critical micelle concentrations (CMC) and that high loaded cationic surfactant does not have good synergistic effect on the degradation due to its hydrophilicity and the block in surface reduction sites. Furthermore degradation of CT by ZVI modified by nonionic surfactant has not positive effect on the degradation as the ionic surfactant and the ZVI modified by anionic surfactant has hardly any obvious effects on the degradation.

  2. An investigation of electronic structure and properties of new chromophore: 3,3'-bithiazolo[3,4-a]pyridinium perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Liu Shixia [Departement fuer Chemie und Biochemie, Universitaet Bern, Freiestrasse 3, CH-3012 Bern (Switzerland)]. E-mail: liu@iac.unibe.ch; Tanner, Christian [Departement fuer Chemie und Biochemie, Universitaet Bern, Freiestrasse 3, CH-3012 Bern (Switzerland); Leutwyler, Samuel [Departement fuer Chemie und Biochemie, Universitaet Bern, Freiestrasse 3, CH-3012 Bern (Switzerland); Bigler, Peter [Departement fuer Chemie und Biochemie, Universitaet Bern, Freiestrasse 3, CH-3012 Bern (Switzerland); Decurtins, Silvio [Departement fuer Chemie und Biochemie, Universitaet Bern, Freiestrasse 3, CH-3012 Bern (Switzerland)

    2007-01-15

    The chromophore 3,3'-bithiazolo[3,4-a]pyridinium 1, obtained by oxidative cyclization reactions using a tetrathiafulvalene as a leaving group, strongly absorbs at the violet end of the visible region as evidenced by its yellow color. The solution (MeCN) spectrum displays an intensive, broad absorption band around 377 nm with a {epsilon} value of 8x10{sup 3} l mol{sup -1} cm{sup -1}. The chromophore also shows a strongly Stokes-shifted fluorescence emission with a lifetime {tau} of 2.8{+-}0.1 ns in acetonitrile solution. Herein, we describe the photophysical properties and a theoretical investigation of the electronic structure of the chiral dicationic, bis(bicyclic) ring assembly 1.

  3. The second harmonic generation and the photoelectric property studies on a new dye, (E)- N-octadecyl-4-[2-(4-dimethylaminophenyl) enamine] pyridinium iodide

    Science.gov (United States)

    Zhai, Jin; Huang, Chun-Hui; Wei, Tian-Xin; Yu, An-Chi; Zhao, Xin-Sheng

    1999-03-01

    According to quantum chemistry calculation, a Schiff-base (E)- N-octadecyl-4-[2-(4-dimethylaminophenyl) enamine] pyridinium iodide with a large dipole moment difference between the excited state and the ground state (Δ μ), is designed and synthesized as a second-order non-linear optical material. Its second-order susceptibility ( χ(2)zzz) is evaluated to be 279.4 pm V -1, which is larger than that of the hemicyanine which is known as one of the best dyes in the second harmonic generation (SHG) behavior. Its LB film formation properties were studied. The photoelectric conversion property is not as good as expected. According to the experiments and the results of the quantum chemistry calculation, an explanation of this phenomenon is proposed.

  4. Aging Effects on the Properties of Imidazolium-, Quaternary Ammonium-, Pyridinium-, and Pyrrolidinium-Based Ionic Liquids Used in Fuel and Energy Production

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Elise B.; Smith, L. Taylor; Williamson, Tyler K.; Kendrick, Sarah E.

    2013-11-21

    Ionic liquids (ILs) are often cited for their excellent thermal stability, a key property for their use as solvents and in the chemical processing of biofuels. However, there has been little supporting data on the long-term aging effect of the temperature on these materials. Imizadolium-, quaternary ammonium-, pyridinium-, and pyrrolidnium-based ILs with the bis(trifluoromethylsulfonyl)imide and bis(perfluoroethylsulfonyl)imide anions were aged for 2520 h (15 weeks) at 200 °C in air to determine the effects of an oxidizing environment on their chemical structure and thermal stability over time. Finally, it was found that the minor changes in the cation chemistry could greatly affect the properties of the ILs over time.

  5. CuS Thin Films Obtained by Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Violeta POPESCU

    2004-02-01

    Full Text Available The paper presents a study concerning the influence of deposition parameters (reagents, electron donors, surfactants, temperature of the substrate, number of consecutive layers, spraying rate on the quality of CuS thin films achieved by spray pyrolysis on glass substrate, from solutions containing CuCl2·2H2O, thiourea, electron pair donors and surfactants. As electron pairs donors ammonia and triethanolamine were used and as surfactants C12 - C14 ether-sulphate, sodium lauryl-sulphate and cetyl-pyridinium bromide were used. The optimum conditions for the obtaining of optically clear, compact and adherent CuS thin films, showing different colors in reflected light (violet, yellow, brawn, green and exhibiting in VIS and NIR light appropriate reflectance and transmittance for utilization for solar control applications were established. The film thickness falls in the range 10- 50 nm.

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

    Science.gov (United States)

    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 (soils (Br content range in soils = 5-40 mg kg(-1)). Information about bromide determination in soils is also possible by analyzing the Br content in water soil extracts. In this case, the TXRF analysis can be directly performed by depositing 10 μL of the internal standardized soil extract sample on a quartz glass reflector in a measuring time of 1500 s. The bromide limit of detection by this approach was 10 μg L(-1). Good agreement was obtained between the TXRF results for the total bromine and bromide determinations in soils and those obtained by other popular analytical techniques, e.g. energy dispersive X-ray fluorescence spectrometry (total bromine) and ionic chromatography (bromide). As a study case, the TXRF method was applied to study bromine accumulation in two agricultural soils fumigated with a methyl bromide pesticide and irrigated with regenerated waste water. PMID:27179429

  7. Absorber performance of a water/lithium-bromide absorption chiller

    Energy Technology Data Exchange (ETDEWEB)

    Xie Guozhen [Beijing University of Civil Engineering and Architecture, Beijing 100044 (China)], E-mail: xieguozhen@bucea.edu.cn; Sheng Guogang [Beijing University of Civil Engineering and Architecture, Beijing 100044 (China); Bansal, Pradeep Kumar [Department of Mechanical Engineering, The University of Auckland, Private Bag 92019 (New Zealand); Li, Guang [Beijing University of Civil Engineering and Architecture, Beijing 100044 (China)

    2008-09-15

    An absorber is one of the most important components of a lithium-bromide absorption chiller (LBAC) as its absorbing characteristics directly influence the performance of the whole chiller. It has been indicated that the absorbing efficiency and cooling capacity could be improved by increasing the solution concentration. In this paper, based on the mechanism of falling film absorption on horizontal tubes, the theoretical models of falling film absorption on horizontal tubes have been established. A series of programs used for computing the theoretical mathematical models, including simulation of LBAC cycle and falling film absorption, have been programmed. The models have been validated reasonably by the experimental data. The results show that the cooling capacity of the LBAC varies in parabola shape of curve with the solution concentration from 52.5% to 58.5%, and that the best coefficient of performance (COP) occurs at concentration of 57%. The investigation proposes the absorbing process of sub-steady thermodynamic equilibrium for the duality solution under increase absorbing pressure.

  8. Absorber performance of a water/lithium-bromide absorption chiller

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Guozhen; Sheng, Guogang; Li, Guang [Beijing University of Civil Engineering and Architecture, Beijing 100044 (China); Bansal, Pradeep Kumar [Department of Mechanical Engineering, The University of Auckland, Private Bag 92019 (New Zealand)

    2008-09-15

    An absorber is one of the most important components of a lithium-bromide absorption chiller (LBAC) as its absorbing characteristics directly influence the performance of the whole chiller. It has been indicated that the absorbing efficiency and cooling capacity could be improved by increasing the solution concentration. In this paper, based on the mechanism of falling film absorption on horizontal tubes, the theoretical models of falling film absorption on horizontal tubes have been established. A series of programs used for computing the theoretical mathematical models, including simulation of LBAC cycle and falling film absorption, have been programmed. The models have been validated reasonably by the experimental data. The results show that the cooling capacity of the LBAC varies in parabola shape of curve with the solution concentration from 52.5% to 58.5%, and that the best coefficient of performance (COP) occurs at concentration of 57%. The investigation proposes the absorbing process of sub-steady thermodynamic equilibrium for the duality solution under increase absorbing pressure. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    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 the use of the model to determine the effect of the various design and input variables on the absorption unit performance. The performance parameters considered were coefficient of performance and cooling capacity. The sensitivity analysis was performed by selecting a nominal condition and determining performance sensitivity for each variable with others held constant. The variables considered in the study include source hot water, cooling water, and chilled water temperatures; source hot water, cooling water, and chilled water flow rates; solution circulation rate; heat exchanger areas; pressure drop between evaporator and absorber; solution pump characteristics; and refrigerant flow control methods. The performance sensitivity study indicated in particular that the distribution of heat exchanger area among the various (seven) heat exchange components is a very-important design consideration. Moreover, it indicated that the method of flow control of the first effect refrigerant vapor through the second effect is a critical design feature when absorption units operate over a significant range of cooling capacity. The model was used to predict the performance of the Trane absorption unit with fairly good accuracy.

  10. Chloride, bromide and iodide scintillators with europium doping

    Science.gov (United States)

    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.

  11. 4-Bromophenacyl bromide specifically inhibits rhoptry secretion during Toxoplasma invasion.

    Science.gov (United States)

    Ravindran, Sandeep; Lodoen, Melissa B; Verhelst, Steven H L; Bogyo, Matthew; Boothroyd, John C

    2009-01-01

    Toxoplasma gondii is a eukaryotic parasite of the phylum Apicomplexa that is able to infect a wide variety of host cells. During its active invasion process it secretes proteins from discrete secretory organelles: the micronemes, rhoptries and dense granules. Although a number of rhoptry proteins have been shown to be involved in important interactions with the host cell, very little is known about the mechanism of secretion of any Toxoplasma protein into the host cell. We used a chemical inhibitor of phospholipase A2s, 4-bromophenacyl bromide (4-BPB), to look at the role of such lipases in the secretion of Toxoplasma proteins. We found that 4-BPB was a potent inhibitor of rhoptry secretion in Toxoplasma invasion. This drug specifically blocked rhoptry secretion but not microneme secretion, thus effectively showing that the two processes can be de-coupled. It affected parasite motility and invasion, but not attachment or egress. Using propargyl- or azido-derivatives of the drug (so-called click chemistry derivatives) and a series of 4-BPB-resistant mutants, we found that the drug has a very large number of target proteins in the parasite that are involved in at least two key steps: invasion and intracellular growth. This potent compound, the modified "click-chemistry" forms of it, and the resistant mutants should serve as useful tools to further study the processes of Toxoplasma early invasion, in general, and rhoptry secretion, in particular. PMID:19956582

  12. Organomontmorillonites Modified with 2-Methacryloyloxy Ethyl Alkyl Dimethyl Ammonium Bromide

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-quan; WU Wen-hui

    2007-01-01

    Organomontmorillonites (organo-MMT) were synthesized by means of montmorillonites (MMT) modified with a series of 2-methacryloyloxy ethyl alkyl dimethyl ammonium bromide (MAAB) having different alkyl chain lengths as cationic surfactants through a cationic exchanging reaction, and were characterized by FTIR, TG, elemental analysis, and XRD. The microenvironment of the organic interlayer such as the orientation and arrangement of the alkyl chains of MAAB, as well as the properties of nanocomposite hydrogels, were also investigated. The amount of organic components absorbed on interlayer and the basal spacing of organo-MMT both increase with the increasing of alkyl length of MAAB. When carbon number of alkyl chain is in the region of 8 to 14, the alkyl chains between layers would adopt a disordered gauche conformation; while the carbon number is 16, an ordered all-trans conformation with a vertical orientation would be found together with the disordered gauche conformation according to the results of XRD and FTIR. Due to the difference of microenvironment of organic interlayer, the Young's moduli of the nanocomposite hydrogels increased as the alkyl chains of MAAB became longer.

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

    Directory of Open Access Journals (Sweden)

    M. Wachsmuth

    2002-01-01

    Full Text Available 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.

  14. Bioreactors for removing methyl bromide following contained fumigations

    Science.gov (United States)

    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.

  15. Evaluation of Alkali Bromide Salts for Potential Pyrochemical Applications

    Energy Technology Data Exchange (ETDEWEB)

    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.

  16. A comparison of the effect of intranasal desmopressin and intramuscular hyoscine N-butyl bromide combination with intramuscular hyoscine N-butyl bromide alone in acute renal colic

    Directory of Open Access Journals (Sweden)

    Abdol-Reza Kheirollahi

    2010-01-01

    Full Text Available Background: Patients with acute renal colic usually require immediate diagnosis and treatment. In this clinical trial analgesic effect of hyoscine N-butyl bromide and desmopressin combination in comparison with hyoscine N-butyl bromide alone in patients with acute renal colic induced by urinary stones was assessed. Methods: The study included 114 patients randomly allocated in two groups (A and B. Patients in group A received 20 mg intramuscular hyoscine N-butyl bromide at admission time and patients in group B received 20 μg of intranasal desmopressin in combination with 20 mg intramuscular hyoscine N-butyl bromide. A visual analogue scale (VAS; a 10-cm horizontal scale ranging from "zero or no pain" to "10 or unbearable pain" was hired to assess the patients′ pain severity at baseline, 30 and 60 minutes after the treatments. Results: On admission, the pain level was similar in both groups (group A: 8.95 ± 0.11 and group B: 8.95 ± 0.12. In group A, the mean of pain level showed a decrease after 30 minutes (group A: 7.26 ± 0.25 and group B: 5.95 ± 0.28 but further decreasing did not occur; however in group B, the pain consistently decreased and the mean after 60 minutes was significantly decreased (group A: 6.80 ± 0.31 and group B: 3.71 ± 0.31. No side effects were detected in this study. Conclusions: The combination of hyoscine N-butyl bromide and desmopressin is more effective than hyoscine N-butyl bromide alone in patients with renal colic. Further studies are recommended to validate these findings and compare the different doses of desmopressin.

  17. Plasmid DNA induces dodecyl triethyl ammonium bromide to aggregate into vesicle

    Institute of Scientific and Technical Information of China (English)

    Xiang Mei Ran; Xia Guo; Jia Tong Ding

    2012-01-01

    Single-chained cationic surfactant dodecyl triethyl ammonium bromide and plasmid DNA together can form vesicles once the concentration of plasmid DNA reaches a critical value (Ccvc).Bigger the size of plasmid DNA,higher the value of Ccvc.

  18. Corrosion Behavior of Austenitic and Duplex Stainless Steels in Lithium Bromide

    OpenAIRE

    Ayo Samuel AFOLABI; Alaneme, K.K.; Samson Oluwaseyi BADA

    2009-01-01

    The corrosion behavior of austenitic and duplex stainless steels in various concentrations of lithium, bromide solution was investigated by using the conventional weight loss measurement method. The results obtained show that corrosion of these steels occurred due to the aggressive bromide ion in the medium. Duplex stainless steel shows a greater resistance to corrosion than austenitic stainless steel in the medium. This was attributed to equal volume proportion of ferrite and austenite in th...

  19. A case report of QT prolongation with glycopyrronium bromide in a patient with chronic tamoxifen use

    OpenAIRE

    Chiu, Michael H.; Al-Majed, Nawaf S.; Stubbins, Ryan; Pollmann, Dylan; Sandhu, Roopinder K.

    2016-01-01

    Background Glycopyrronium bromide has recently been approved as a once daily maintenance inhalation therapy for moderate to severe chronic obstructive pulmonary disease (COPD). Efficacy and safety trial data have found rare cases of significant QT prolongation. To our knowledge, we describe the first case report of QT prolongation >600 ms with initiation of glycopyrronium bromide in a real world setting. Case presentation A 78-year-old female with moderate COPD recently started on glycopyrron...

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    Wöltje, M; Huchzermeyer, H

    1982-01-01

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

  2. Inhibition of methoxamine-induced bronchoconstriction by ipratropium bromide and disodium cromoglycate in asthmatic subjects.

    OpenAIRE

    Black, J.; Vincenc, K; Salome, C.

    1985-01-01

    We compared the effects of pretreatment with saline, ipratropium bromide, and disodium cromoglycate (DSCG) on bronchoconstriction induced by methoxamine--an alpha-adrenoceptor agonist, in asthmatic subjects. All 12 patients bronchoconstricted in response to methoxamine after saline. The PD20 (the dose of methoxamine causing a 20% fall in forced expiratory volume in 1 s [FEV1]) ranged from 0.3-18 mumol. Ipratropium bromide (200 micrograms administered by aerosol) significantly inhibited (P les...

  3. Tribromoisocyanuric acid/triphenylphosphine: a new system for conversion of alcohols into alkyl bromides

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Vitor S.C. de; Mattos, Marcio C.S. de, E-mail: mmattos@iq.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Instituto de Quimica. Departamento de Quimica Organica

    2014-05-15

    An efficient and facile method has been developed for the conversion of alcohols into alkyl bromides under neutral conditions using tribromoisocyanuric acid and triphenylphosphine (molar ratio 1.0:0.7:2.0, alcohol/tribromoisocyanuric acid/triphenylphosphine) in dichloromethane at room temperature. This method can be applied for the conversion of primary, secondary, benzilic and allylic alcohols, and their corresponding bromides are obtained in 67-82 % yield. Tertiary alcohols do not react under these conditions. (author)

  4. Electrochemical Recognition of Metalloproteins by Bromide-modified Silver Electrode - A New Method

    Directory of Open Access Journals (Sweden)

    Abbas Ali Rostami

    2007-07-01

    Full Text Available A bromide–modified silver electrode is reported, in the present study, to catalyzethe redox reactions of metalloproteins. This study describes that the bromide ions showvery good redox behavior with silver electrode. The cathodic and anodic peak potentialswere related to the concentration of bromide ions involved in making bromide-modifiedsilver electrode. The electrode reaction in the bromine solution was a diffusion-controlledprocess. Positive potential shift of the bromide ions was seen when different proteins wereadded to the solution using a silver electrode. New cathodic and anodic peaks wereobserved at different potential ranges for myoglobin, cytochrome c and catalase. A linearlyincreasing cathodic peak current of bromide ions was seen when the concentration ofsuperoxide dismutase was increased in the test solution. However, no change for albuminwas observed when its concentration was increased in the test solution. Present data provesour methodology as an easy-to-use analysis for comparing the redox potentials of differentmetalloproteins and differentiating the metallo- from non-metalloproteins. In this study, weintroduced an interesting method for bio-electrochemical analyses.

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

    Institute of Scientific and Technical Information of China (English)

    Shaogang Liu; Zhiliang Zhu; Yanling Qiu; Jianfu Zhao

    2011-01-01

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

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

    Science.gov (United States)

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

    2011-01-01

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

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

    Science.gov (United States)

    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.

  8. Bacterial oxidation of methyl bromide in fumigated agricultural soils

    Science.gov (United States)

    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.

  9. The killing of African trypanosomes by ethidium bromide.

    Directory of Open Access Journals (Sweden)

    Arnab Roy Chowdhury

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

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

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  13. Aclidinium bromide combined with formoterol inhibits remodeling parameters in lung epithelial cells through cAMP.

    Science.gov (United States)

    Lambers, Christopher; Costa, Luigi; Ying, Qi; Zhong, Jun; Lardinois, Didier; Dekan, Gerhard; Schuller, Elisabeth; Roth, Michael

    2015-12-01

    Combined muscarinic receptor antagonists and long acting β2-agonists improve symptom control in chronic obstructive pulmonary disease (COPD) significantly. In clinical studies aclidinium bromide achieved better beneficial effects than other bronchodilators; however, the underlying molecular mechanisms are unknown. This study assessed the effect of aclidinium bromide combined with formoterol on COPD lung (n=20) and non-COPD lung (n=10) derived epithelial cells stimulated with TGF-β1+carbachol on: (i) the generation of mesenchymal cells in relation to epithelial cells, (II) extracellular matrix (ECM) deposition, and (iii) the interaction of ECM on the generation of epithelial and mesenchymal cells. TGF-β1+carbachol enhanced the generation of mesenchymal cells, which was significantly reduced by aclidinium bromide or formoterol. The effect of combined drugs was additive. Inhibition of p38 MAP kinase and Smad by specific inhibitors or aclidinium bromide reduced the generation of mesenchymal cells. In mesenchymal cells, TGF-β1+carbachol induced the deposition of collagen-I and fibronectin which was prevented by both drugs dose-dependently. Formoterol alone reduced collagen-I deposition via cAMP, this however, was overruled by TGF-β1+carbachol and rescued by aclidinium bromide. Inhibition of fibronectin was cAMP independent, but involved p38 MAP kinase and Smad. Seeding epithelial cells on ECM collagen-I and fibronectin induced mesenchymal cell generation, which was reduced by aclidinium bromide and formoterol. Our results suggest that the beneficial effect of aclidinium bromide and formoterol involves cAMP affecting both, the accumulation of mesenchymal cells and ECM remodeling, which may explain the beneficial effect of the drugs on lung function in COPD. PMID:26546746

  14. Crystal structure of tris-[4-(di-methyl-amino)-pyridinium] tris-(oxalato-κ(2) O,O')chromate(III) tetra-hydrate.

    Science.gov (United States)

    Makon Ma Houga, Noé; Capet, Frédéric; Nenwa, Justin; Bebga, Gouet; Foulon, Michel

    2015-11-01

    In the title hybrid salt, (C7H11N2)3[Cr(C2O4)3]·4H2O, the central Cr(III) ion of the complex anion (point group symmetry 2) is coordinated by six O atoms from three chelating oxalate(2-) ligands in a slightly distorted octa-hedral coordination sphere. The Cr-O bond lengths vary from 1.9577 (11) to 1.9804 (11) Å, while the chelate O-Cr-O angles range from 82.11 (6) to 93.41 (5)°. The 4-(di-methyl-amino)-pyridinium cations (one situated in a general position and one on a twofold rotation axis) are protonated at the pyridine N atoms. In the crystal, N-H⋯O and O-H⋯O hydrogen bonds link the cations and anions into a three-dimensional network. π-π inter-actions between the pyridine rings of adjacent cations provide additional stabilization of the crystal packing, with the closest centroid-to-centroid distances being 3.541 (1) and 3.575 (1) Å. PMID:26594521

  15. Two-photon absorption effect and the intra-molecular charge transfer of p-substituted stilbene-type pyridinium salts

    Institute of Scientific and Technical Information of China (English)

    王筱梅; 周玉芳; 王春; 赵显; 刘志强; 蒋民华; 孙真荣; 丁良恩

    2001-01-01

    The relationships between two-photon absorption (TPA) effect and excited state intra-molecular charge transfer (ICT) of p-substituted stilbene-type pyridinium salts have been investigated. Two-photon absorption cross section (δTPA) for all the compounds has been determined by open aperture Z-scanning technique, while two-photon pumped (TPP) up-converted lasing efficiencies (η) and optical limiting behavior have been measured by two-channel energy-meter, pumped by a mode locked Nd: YAG ps laser. Streak camera was used to record two-photon induced fluorescence and the fluorescence lifetimes. The experimental and calculated results have shown that the excited state larger intra-molecular charge transfer, in the excited state characterized by the charge density difference between the ground state (S0) and the first excited state (S1), has contributed to enhancing TPA cross section and may result in better optical limiting effect. And high TPP up-converted lasing efficiency is related to not only the δTPA value, but also the lifetime of two-photon induced fluorescence, etc.

  16. Reversed phase-high performance liquid chromatographic method to measure migration of semivolatile compound, vanillin, in ipratropium bromide inhalation solution

    OpenAIRE

    Conkins, Dennis; Economou, Julia E; Boersma, James A; Dedhiya, Mehendra G; Hansen, Gordon

    1999-01-01

    Ipratropium bromide, a bronchodilator, is used as an inhalation solution. Commercial ipratropium bromide solution products are packaged in low-density polyethylene (LDPE) vials, through which semivolatile compounds are reported to migrate. In this article, a specific reversed phase-high performance liquid chromatographic method to assay vanillin, a semivolatile compound, in ipratropium bromide solution is described. The method was validated for a concentration range for vanillin from 30 ng/mL...

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

    Science.gov (United States)

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

    2016-03-01

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

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

    Science.gov (United States)

    Good, Kelly D; VanBriesen, Jeanne M

    2016-09-01

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

  19. Corrosion Behavior of Austenitic and Duplex Stainless Steels in Lithium Bromide

    Directory of Open Access Journals (Sweden)

    Ayo Samuel AFOLABI

    2009-07-01

    Full Text Available The corrosion behavior of austenitic and duplex stainless steels in various concentrations of lithium, bromide solution was investigated by using the conventional weight loss measurement method. The results obtained show that corrosion of these steels occurred due to the aggressive bromide ion in the medium. Duplex stainless steel shows a greater resistance to corrosion than austenitic stainless steel in the medium. This was attributed to equal volume proportion of ferrite and austenite in the structure of duplex stainless steel coupled with higher content of chromium in its composition. Both steels produced electrochemical noise at increased concentrations of lithium bromide due to continuous film breakdown and repair caused by reduction in medium concentration by the alkaline corrosion product while surface passivity observed in duplex stainless steel is attributed to film stability on this steel.

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

    International Nuclear Information System (INIS)

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

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

    Science.gov (United States)

    Itoh, Z; Takahashi, I

    1981-01-01

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

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

    International Nuclear Information System (INIS)

    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

  3. Thermodynamic evaluation of new absorbent mixtures of lithium bromide and organic salts for absorption refrigeration machines

    Energy Technology Data Exchange (ETDEWEB)

    Donate, Marina; Rodriguez, Luis; Lucas, Antonio De; Rodriguez, Juan F. [Department of Chemical Engineering, University of Castilla-La Mancha, Avda. de Camilo Jose Cela s/n, 13004 Ciudad Real (Spain)

    2006-01-01

    Mixtures of lithium bromide and organic salts of sodium and potassium (formate, acetate and lactate) have been evaluated as alternative absorbents for absorption refrigeration machines. The main objective is to overpass the limitations of lithium bromide and improve the characteristics and the efficiency of the refrigeration cycle. In order to select the mixture that presents better properties for its employment in absorption refrigeration cycles, a thermodynamic analysis have been done. Density, viscosity, enthalpies of dilution, solubility and vapour pressure data of the proposed mixtures have been measured. A simulation program has been developed to evaluate temperatures, heats exchanged in the different sections and the efficiency of the cycle. (author)

  4. COMPARISON OF ROCURONIUM BROMIDE AND SUCCINYLCHOLINE CHLORIDE FOR USE DURING RAPID SEQUENCE INTUBATION IN ADULTS

    Directory of Open Access Journals (Sweden)

    Ch. Penchalaiah

    2015-08-01

    Full Text Available BACKGROUND AND OBJECTIVE : The goal of rapid sequence intubation is to secure the patients airway smoothly and quickly, minimizing the chances of regurgitation and aspiration of gastric contents. Traditionally succinylcholine chloride has been the neuromuscular blocking drug of choi ce for use in rapid sequence intubation because of its rapid onset of action and profound relaxation. Succinylcholine chloride remains unsurpassed in providing ideal intubating conditions. However the use of succinylcholine chloride is associated with many side effects like muscle pain, bradycardia, hyperkalaemia and rise in intragastric and intraocular pressure. Rocuronium bromide is the only drug currently available which has the rapidity of onset of action like succinylcholine chloride. Hence the present study was undertaken to compare rocuronium bromide with succinylcholine chloride for use during rapid sequence intubation in adult patients. METHODOLOGY : The study population consisted of 90 patients aged between 18 - 60 years posted for various elective su rgeries requiring general anaesthesia . S tudy population was randomly divided into 3 groups with 30 patients in each sub group. 1. Group I : Intubated with 1 mg kg - 1 of succinylcholine chloride (n=30 . 2. Grou p II : Intubated with rocuronium bromide 0.6 mg kg - 1 (n=30 . 3. Group III : Intubated with rocuronium bromide 0.9 mg kg - 1 (n=30 . Intubating conditions were assessed at 60 seconds based on the scale adopted by Toni Magorian et al. 1993. The haemodynamic para meters in the present study were compared using p - value obtained from student t - test . RESULTS : It was noted that succinylcholine chloride 1 mg kg - 1 body weight produced excellent intubating conditions in all patients. Rocuronium bromide 0.6 mg kg - 1 body we ight produced excellent intubating conditions in 53.33% of patients but produced good to excellent intubating conditions in 96.67% of patients. Rocuronium bromide 0.9 mg kg - 1

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

    OpenAIRE

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

    2015-01-01

    Direct comparison between perovskite-structured hybrid organic-inorganic - methyl ammonium 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 MAPbB...

  6. Well-Defined Copper(I) Fluoroalkoxide Complexes for Trifluoroethoxylation of Aryl and Heteroaryl Bromides

    KAUST Repository

    Huang, Ronglu

    2015-03-17

    © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Copper(I) fluoroalkoxide complexes bearing dinitrogen ligands were synthesized and the structure and reactivity of the complexes toward trifluoroethoxylation, pentafluoropropoxylation, and tetrafluoropropoxylation of aryl and heteroaryl bromides were investigated. Efficiency drive: A series of copper(I) fluoroalkoxide complexes bearing N,N ligands have been prepared and structurally characterized. These well-defined complexes serve as efficient reagents for the fluoroalkoxylation of aryl and heteroaryl bromides to produce a wide range of trifluoroethyl, pentafluoropropyl, and tetrafluoropropyl (hetero)aryl ethers in good to excellent yields.

  7. Once-daily glycopyrronium bromide (Seebri Breezhaler(®)) for the treatment of chronic obstructive pulmonary disease (COPD)

    DEFF Research Database (Denmark)

    Ulrik, Charlotte Suppli

    2015-01-01

    also on health status. Furthermore, glycopyrronium bromide also has beneficial effects on dynamic hyperinflation and, probably by that, exercise tolerance. Glycopyrronium bromide has been shown to reduce the rate of exacerbations in patients with moderate to severe COPD, although as a secondary outcome...

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

    Science.gov (United States)

    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...

  9. Iodine catalyzed and tertiary butyl ammonium bromide promoted p reparation of b enzoxazaphosphininyl phenylboronates

    Directory of Open Access Journals (Sweden)

    K. R. Kishore K. Reddy,

    2009-05-01

    Full Text Available Benzoxazaphosphininyl Phenylboronates were prepared by O-Phosphorylation of potassium salt ofphenylboronic acid with cyclic phosphoromonochloridates in the presence of stoichiometric amount of Iodineand catalytic amount of tertiary butyl ammonium bromide at 50-60 °C in dry toluene.

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

    Science.gov (United States)

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

    2016-04-01

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

  11. Palladium-Catalyzed Carbonylation of Aryl Bromides with N-Substituted Cyanamides

    DEFF Research Database (Denmark)

    Lian, Zhong; Friis, Stig D.; Lindhardt, Anders T.;

    2014-01-01

    The palladium(0)-catalyzed three-component coupling reaction of aryl bromides, carbon monoxide, and N-alkyl cyan­amides has been developed employing a two-chamber system with ex situ generation of carbon monoxide from a silacarboxylic acid. The reactions proceeded well and were complete with a...

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

    Science.gov (United States)

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

    2014-08-15

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

  13. Palladium-catalyzed carbonylative sonogashira coupling of aryl bromides using near stoichiometric carbon monoxide

    DEFF Research Database (Denmark)

    Neumann, Karoline T.; Laursen, Simon R.; Lindhardt, Anders T.;

    2014-01-01

    A general procedure for the palladium-catalyzed carbonylative Sonogashira coupling of aryl bromides is reported, using near stoichiometric amounts of carbon monoxide. The method allows a broad substrate scope in moderate to excellent yields. The formed alkynone motive serves as a platform for...

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

    NARCIS (Netherlands)

    Leistra, M.; Boesten, J.J.T.I.

    2010-01-01

    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. R

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

    Science.gov (United States)

    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...

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

    Science.gov (United States)

    Fang, Jing-Yun; Shang, Chii

    2012-08-21

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

  17. Strontium and bromide as tracers in X-ray microanalysis of biological tissue

    Energy Technology Data Exchange (ETDEWEB)

    Wroblewski, J.; Sagstroem, S.M.; Mulders, H.; Roomans, G.M. (Karolinska Institutet, Stockholm (Sweden))

    1989-09-01

    Since energy dispersive X-ray microanalysis cannot distinguish between isotopes of the same element, alternative methods have to be used to get information similar to that obtained in experiments with radioactive tracers. In the present study, strontium was used as a tracer for calcium, and bromide as a tracer for chloride. Rats were injected with strontium chloride in vivo, and the uptake of strontium in the acinar cells of the submandibular gland was studied. Eventually a Sr/Ca ratio of 0.3 was reached. In some animals, secretion of mucus had been elicited by stimulation with isoproterenol 4 h prior to injection of strontium chloride. Exchange of calcium for strontium was enhanced by prior injection with isoproterenol. In a second experiment, rats were injected with sodium bromide, and the uptake of bromide by the submandibular acinar cells was followed in time, both in pilocarpine-stimulated and unstimulated glands. Under the experimental conditions, bromide was rapidly taken up by the cells, and the cellular Br/Cl ratio was close to that found in serum. Submandibular glands take up Br somewhat faster than other tissues (liver, heart muscle, skeletal muscle). The uptake of Br in pancreatic acinar cells was studied in vitro. These experiments showed a 1:1 ratio (molar) exchange of Cl for Br.

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

    International Nuclear Information System (INIS)

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

  19. Facile Syntheses of N-Substituted Imidazoles and Benzotriazoles from Baylis-Hillman Bromides

    Institute of Scientific and Technical Information of China (English)

    YE Dongyan; LI Jian; LI Chunju; JIA Xueshun

    2009-01-01

    A facile synthesis of N-substituted imidazole and benzotriazole derivatives from Baylis-Hiilman bromides with imidazole and benzotriazole at room temperature was reported. In view of the simple operation, mild reaction con-ditions, good to excellent yields, good regio- and stereoselectivity, the present method exhibited its superiority.

  20. Efficient loading of primary alcohols onto a solid phase using a trityl bromide linker

    DEFF Research Database (Denmark)

    Crestey, François; Ottesen, Lars Korsgaard; Jaroszewski, Jerzy Witold;

    2008-01-01

    The Letter describes an improved, rapid and mild strategy for the loading of primary alcohols onto a polystyrene trityl resin via a highly reactive trityl bromide linker. This protocol facilitates an efficient resin loading even of acid-sensitive or heat-labile alcohols, which otherwise require...

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

    Science.gov (United States)

    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...

  2. SYNTHESIS AND CATALYTIC PROPERTIES OF CROSS-LINKED HYDROPHOBICALLY ASSOCIATING POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES)

    NARCIS (Netherlands)

    WANG, GJ; ENGBERTS, JBFN

    1994-01-01

    Cross-linked, hydrophobically associating homo- and copolymers were synthesized by free-radical cyclo(co)polymerization of alkylmethyldiallylammonium bromide monomers with a small amount of N,N'-methylenebisacrylamide in aqueous solution using ammonium persulfate as the initiator. The cross-linked h

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

    Science.gov (United States)

    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.

  4. 76 FR 29238 - Methyl Bromide; Cancellation Order for Registration Amendments To Terminate Certain Soil Uses

    Science.gov (United States)

    2011-05-20

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

  5. Ozone decomposition under the irradiation of 253.7 nm in the presence of methyl bromide

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper the mechanism and kinetic of ozone decomposition under the irradiation of 253.7 nm UV-light were studied.The quantum yield of the ozone depletion in the presence of methyl bromide is further determined and a reaction model is provided to explain the experimental fact.

  6. COMPARISON OF ONSET TIME, DURATION OF ACTION AND INTUBATING CONDITION SACHIEVED WITH SUXAMETHONIUM AND ROCURONIUM BROMIDE

    OpenAIRE

    Ajit P; Alok P; Devendra Singh

    2013-01-01

    Adverse event profile ofSuxamethonium which is still the relaxant of choice to facilitate tracheal intubation inspired us to conduct a study in which we compared Onset time, Duration of Action and Intubating Conditions Achieved with Suxametho nium and Rocuronium Bromide with the Help of TOF Guard. AIMS : W e compared the onset of relaxation time, intubating condition, and duration of action, the ...

  7. Effect of pinaverium bromide on stress-induced colonic smooth muscle contractility disorder in rats

    OpenAIRE

    Dai, Yun; Liu, Jian-Xiang; Li, Jun-Xia; Xu, Yun-Feng

    2003-01-01

    AIM: To investigate the effect of pinaverium bromide, a L-type calcium channel blocker with selectivity for the gastrointestinal tract on contractile activity of colonic circular smooth muscle in normal or cold-restraint stressed rats and its possible mechanism.

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

    Science.gov (United States)

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

    1983-03-01

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

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

    Science.gov (United States)

    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...

  10. Reaction of Polymer-supported Selenovinyl Bromide with Grignard Reagents: A Facile Route to the Synthesis of(E)-1, 2-Disubstituted Olefins

    Institute of Scientific and Technical Information of China (English)

    E TANG; Xiang Jin LIN; Lu Ling WU

    2005-01-01

    Polymer-supported selenovinyl bromide, easily prepared from polymer-supported selenenyl bromide with acetylene, reacts with different Grignard reagents using a step-by-step strategy to obtain (E)-1, 2-disubstituted ethenes in good yields.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    1999-02-28

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

  13. (E-1-Methyl-4-[2-(2-naphthylvinyl]pyridinium iodideThis paper is dedicated to the late Her Royal Highness Princess Galyani Vadhana Krom Luang Naradhiwas Rajanagarindra for her patronage of Science in Thailand.

    Directory of Open Access Journals (Sweden)

    Hoong Kun Fun

    2009-06-01

    Full Text Available In the title compound, C18H16N+·I−, the cation is disordered over two orientations related by a 180° rotation about its long axis with occupancies of 0.554 (7 and 0.446 (7. Both disorder components exist in an E configuration. The dihedral angle between the pyridinium ring and the naphthalene ring system is 4.7 (6° in the major disorder component and 1.6 (8° in the minor component. In the crystal structure, centrosymmetrically related cations are stacked along the a axis, with significant π–π interactions between the pyridinium ring and the naphthalene ring system [centroid-centroid distance = 3.442 (9 Å]. The iodide ions are located between adjacent columns of cations. The cations are linked to the iodide ions by C—H...I interactions. Weak C—H...π interactions involving the methyl group are also observed.

  14. Determination of bromine contents in blood and hair of workers exposed to methyl by radioactivation analysis method bromide

    International Nuclear Information System (INIS)

    The bromine contained in blood and hair samples obtained from workers exposed to methyl bromide was analyzed by nondestructive activation analysis. The samples were irradiated for 1 min in pneumatic irradiation facility of Kyoto University research reactor with an estimated thermal neutron flux density at 2 x 1013 n.cm-2.sec-1. The irradiation was counted with Ge(Li) detector. The duration of measurement of radionuclide bromine in blood and hair was 200 sec within 2 - 10 min after irradiation. The bromine content of serum sample obtained from a worker suspected of methyl bromide poisoning was found to be 412 μg/g on 13 days apart from exposure to methyl bromide. The biological half-life of bromine in this case was found to be about 16 days. Then bromine contents in serum and hair samples obtained from workers exposed to methyl bromide were found to be 1.7 and 2.6 times higher respectively than those of nonexposed workers. Any correlations of bromine contents were not observed between serum and hair samples obtained from workers exposed to methyl bromide, nor between bromine amount in the serum of workers exposed to methyl bromide and the terms exposed to it, but statistically significant positive correlation was observed between bromine amount in the hair of workers exposed to methyl bromide and the terms exposed to it. (author)

  15. Comparative microvascular exchange kinetics of [{sup 77}Br]bromide and {sup 99m}Tc-DTPA in humans

    Energy Technology Data Exchange (ETDEWEB)

    Cousins, Claire [Department of Clinical Radiology, Addenbrooke' s Hospital, Cambridge (United Kingdom); Skehan, Stephen J.; Rolph, Susan M.; Flaxman, Mary E.; Ballinger, James R.; Bird, Nicholas J.; Barber, Robert W.; Peters, Michael A. [Department of Nuclear Medicine, Addenbrooke' s Hospital, Cambridge (United Kingdom)

    2002-05-01

    The plasma clearance curves of small hydrophilic solutes comprise three exponentials, consistent with a three-compartmental distribution model. A previous comparison between inulin and diethylene triamine penta-acetic acid (DTPA) suggested that these three compartments are in series, the first being plasma and the second and third representing compartments within the extravascular space. Moreover, whilst the total distribution volumes of these two indicators were similar, the volume of the second compartment was higher for DTPA. The purpose of the current study was to investigate whether a solute smaller than DTPA, namely bromide, fits the hypothesis that the second space volume is an inverse function of the size of the solute. Two groups of subjects were studied: group A comprised eight patients undergoing routine diagnostic arteriography and group B, eight patients referred for routine measurement of glomerular filtration rate plus two normal volunteers. {sup 99m}Tc-DTPA and sodium [{sup 77}Br]bromide were intravenously administered simultaneously. In group A, frequent arterial samples were obtained up to 40 min after injection, and antecubital venous samples 30 s after each arterial sample. In group B, frequent venous samples were obtained up to 280 min after injection. Volume measurements based on bromide were corrected for erythrocyte bromide accumulation. In both subject groups, the normalised venous concentration ratio of bromide to DTPA, corrected for red cell bromide uptake, was significantly less than unity in the earliest blood samples, being 0.56 (SD 0.08) at 1 min, consistent with faster diffusion of bromide from plasma to interstitial fluid. Furthermore, the extraction fraction of bromide from plasma to interstitial fluid in the forearm was about 0.6, higher than that of DTPA (about 0.5) in spite of red cell bromide accumulation which equilibrated with plasma bromide within 20 s and resulted in a red cell to plasma concentration ratio of 0.51 (0

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

    Science.gov (United States)

    Malik, Michał; Jarosz, Sławomir

    2016-02-01

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

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

    Directory of Open Access Journals (Sweden)

    Arievich Helen

    2012-12-01

    Full Text Available Abstract Background Glycopyrronium bromide (NVA237 is an inhaled long-acting muscarinic antagonist in development for treatment of COPD. This study compared the efficacy and safety of once-daily (OD and twice-daily (BID glycopyrronium bromide regimens, using a novel model-based approach, in patients with moderate-to-severe COPD. Methods Double-blind, randomized, dose-finding trial with an eight-treatment, two-period, balanced incomplete block design. Patients (smoking history ≥10 pack-years, post-bronchodilator FEV1 ≥30% and 1/FVC 1 at Day 28. Results 385 patients (mean age 61.2 years; mean post-bronchodilator FEV1 53% predicted were randomized; 88.6% completed. All OD and BID dosing regimens produced dose-dependent bronchodilation; at Day 28, increases in mean trough FEV1 versus placebo were statistically significant for all regimens, ranging from 51 mL (glycopyrronium bromide 12.5 μg OD to 160 mL (glycopyrronium bromide 50 μg BID. Pharmacodynamic steady-state was reached by Day 7. There was a small separation (≤37 mL between BID and OD dose–response curves for mean trough FEV1 at steady-state in favour of BID dosing. Over 24 hours, separation between OD and BID regimens was even smaller (FEV1 AUC0-24h maximum difference for equivalent daily dose regimens: 8 mL. Dose–response results for FEV1 at 12 hours, FEV1 AUC0-12h and FEV1 AUC0-4h at steady-state showed OD regimens provided greater improvement over placebo than BID regimens for total daily doses of 25 μg, 50 μg and 100 μg, while the reverse was true for OD versus BID regimens from 12–24 hours. The 12.5 μg BID dose produced a marginally higher improvement in trough FEV1 versus placebo than 50 μg OD, however, the response at 12 hours over placebo was suboptimal (74 mL. Glycopyrronium bromide was safe and well tolerated at all doses. Conclusions Glycopyrronium bromide 50 μg OD provides significant bronchodilation over a 24 hour period

  18. Facile Synthesis of Heterocycles via 2-Picolinium Bromide and Antimicrobial Activities of the Products

    Directory of Open Access Journals (Sweden)

    Elham S. Darwish

    2008-05-01

    Full Text Available The 2-picolinium N-ylide 4, generated in situ from the N-acylmethyl-2-picolinium bromide 3, underwent cycloaddition to N-phenylmaleimide or carbon disulfideto give the corresponding cycloadducts 6 and 8, respectively similar reactions ofcompound 3 with some electron-deficient alkenes in the presence of MnO2 yielded theproducts 11 and 12. In addition, reaction of 4 with arylidene cyanothioacetamide andmalononitrile derivatives afforded the thiophene and aniline derivatives 15 and 17,respectively. Heating of picolinium bromide 3 with triethylamine in benzene furnished 2-(2-thienylindolizine (18. The structures of the isolated products were confirmed byelemental analysis as well as by 1H- and 13C-NMR, IR, and MS data. Both thestereochemistry and the regioselectivity of the studied reactions are discussed. Thebiological activity of the newly synthesized compounds was examined and showedpromising results.

  19. Indirect complexometric determination of mercury(II) using potassium bromide as selective masking agent

    International Nuclear Information System (INIS)

    A complexometric method for the determination of mercury in presence of other metal ions based on the selective masking ability of potassium bromide towards mercury is described. Mercury(II) present in a given sample solution is first complexed with a known excess of EDTA and the surplus EDTA is titrated against zinc sulfate solution at pH 5-6 using xylenol orange as the indicator. A known excess of 10 % solution of potassium bromide is then added and the EDTA released from Hg-EDTA complex is titrated against standard zinc sulfate solution. Reproducible and accurate results are obtained for 8 mg to 250 mg of mercury(II) with a relative error ±0.28 % and standard deviations /leg 0.5 mg. The interference of various ions is studied. This method was applied to the determination of mercury(II) in its alloys. (author)

  20. Thermodynamic Properties of Hydrogen + Tetra-n-Butyl Ammonium Bromide Semi-Clathrate Hydrate

    Directory of Open Access Journals (Sweden)

    Shunsuke Hashimoto

    2010-01-01

    Full Text Available Thermodynamic stability and hydrogen occupancy on the hydrogen + tetra-n-butyl ammonium bromide semi-clathrate hydrate were investigated by means of Raman spectroscopic and phase equilibrium measurements under the three-phase equilibrium condition. The structure of mixed gas hydrates changes from tetragonal to another structure around 95 MPa and 292 K depending on surrounding hydrogen fugacity. The occupied amount of hydrogen in the semi-clathrate hydrate increases significantly associated with the structural transition. Tetra-n-butyl ammonium bromide semi-clathrate hydrates can absorb hydrogen molecules by a pressure-swing without destroying the hydrogen bonds of hydrate cages at 15 MPa or over.

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

    Science.gov (United States)

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

    1992-01-01

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

  2. Formation pathways of brominated products from benzophenone-4 chlorination in the presence of bromide ions

    Institute of Scientific and Technical Information of China (English)

    Ming Xiao; Dongbin Wei; Liping Li; Qi Liu; Huimin Zhao; Yuguo Du

    2014-01-01

    The brominated products,formed in chlorination treatment of benzophenone-4 in the presence of bromide ions,were identified,and the formation pathways were proposed.Under disinfection conditions,benzophenone-4 would undertake electrophilic substitution generating mono-or di-halogenated products,which would be oxidized to esters and further hydrolyzed to phenol derivatives.The generated catechol intermediate would be transformed into furan-like heterocyclic product.The product species were pH-dependent,while benzophenone-4 ehmination was chlorine dose-dependent.When the chlorination treatment was performed on ambient water spiked with benzophenone-4 and bromide ions,most of brominated byproducts could be detected,and the acute toxicity significantly increased as well.

  3. Synthesis of Dimethyl Aryl Acylsulfonium Bromides from Aryl Methyl Ketones in a DMSO-HBr System

    OpenAIRE

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

    2013-01-01

    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.

  4. Linear free energy relationship in reactions between diphenyl amine and benzyl bromides

    Indian Academy of Sciences (India)

    S Ranga Reddy; P Manikyamba

    2006-05-01

    Rate of reaction between benzyl bromide and diphenyl amine is retarded by electron-donating groups and enhanced by electron-withdrawing groups present on the benzene ring of the substrate. Hammett's reaction constant of the reaction decreases with increase in temperature according to the equation, \\rho = -11.92 + 3.54/ T. Minimal structural effects observed are attributed to the fact that the isokinetic temperature of the reaction is close to the reaction temperature.

  5. Comparison of injection drotaverine and injection valethamate bromide on duration and course of labor

    OpenAIRE

    Pradnya Rajendra Changede

    2016-01-01

    Background: Numerous drugs have been used to shorten the active phase of labor. How rationale is it to use these drugs to shorten the active phase of labor? Do they really shorten the duration of labor? What adverse effects do they have on the baby and the mother? These questions were the basis to perform the present study of comparing two of such drugs, injection drotaverine and injection Valethamate bromide with control subjects. Methods: This was a prospective study conducted in a terti...

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

    Energy Technology Data Exchange (ETDEWEB)

    Long, Yan; Lin, Zuoxian [Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China); Xia, Menghang; Zheng, Wei [National Center for Advancing Translational Sciences, National Institutes of Health, Bethesda, MD 20892 (United States); Li, Zhiyuan, E-mail: li_zhiyuan@gibh.ac.cn [Key Laboratory of Regenerative Biology, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530 (China)

    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.

  7. Effect of Impeller Agitation on Preparation of Tetra-n-Butyl Ammonium Bromide Semiclathrate Hydrate Slurries

    OpenAIRE

    Yoshiro Inoue; Kazunari Ohgaki; Shunsuke Hashimoto; Hiroyuki Ito

    2012-01-01

    The slurries-containing tetra-n-butyl ammonium bromide (TBAB) solution and its semiclathrate hydrate have attracted a lot of interest as latent heat transport media. These hydrate slurries contain some microparticles of crystal, and the size and shape of these hydrate particles could affect the mobility of slurries. Hence, it is essential to investigate the efficient hydrate-slurry preparation methods and the effect of hydrate particles on the fluid property of slurries for the application to...

  8. Acute hepatitis after starting pinaverium bromide in a patient taking mirtazapine

    OpenAIRE

    Tak, Sandeep; Tak, Shubhanjali

    2014-01-01

    A 56-year-old man presented with chronic abdominal pain. He had been evaluated extensively in the recent past undergoing upper gastrointestinal endoscopy, colonoscopy and CT scan of the abdomen with normal results. The provisional diagnosis of irritable bowel syndrome was performed and pinaverium bromide was started. The patient had pre-existing hypertension, a major depressive disorder and gastro-oesophageal reflux disease. He had been taking nebivolol and pantoprazole for several years and ...

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

    Science.gov (United States)

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

    1998-04-01

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

  10. Tetrabutylammonium Bromide (TBABr)-Based Deep Eutectic Solvents (DESs) and Their Physical Properties

    OpenAIRE

    Rizana Yusof; Emilia Abdulmalek; Kamaliah Sirat; Mohd. Basyaruddin Abdul Rahman

    2014-01-01

    Density, viscosity and ionic conductivity data sets of deep eutectic solvents (DESs) formed by tetrabutylammonium bromide (TBABr) paired with ethlyene glycol, 1,3-propanediol, 1,5-pentanediol and glycerol hydrogen bond donors (HBDs) are reported. The properties of DES were measured at temperatures between 303 K and 333 K for HBD percentages of 66.7% to 90%. The effects of HBDs under different temperature and percentages are systematically analyzed. As expected, the measured density and viscos...

  11. Tiotropium bromide in the routine care of GOLD stage II COPD patients: a pharmaeconomic evaluation

    OpenAIRE

    Orietta Zaniolo; Michela Carsi; Sergio Iannazzo

    2011-01-01

    Background: a secondary pre-specified analysis of the UPLIFT cohort demonstrated that the inclusion of tiotropium bromide in the routine care of GOLD stage II (moderate) chronic obstructive pulmonary disease (COPD) patients is associated with stronger improvements of survival, quality of life, and exacerbation rate than those shown in the total cohort; in this subgroup, tiotropium furthermore induces a significant reduction in the rate of FEV1 decline.Objective: to adapt the Spiriva® model, o...

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

    Science.gov (United States)

    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.

  13. A bio-product as alternative to methyl bromide for replant disease control on strawberry

    Institute of Scientific and Technical Information of China (English)

    Yu ZHANG; Tongle HU; Lijing JI; Keqiang CAO

    2008-01-01

    Pre-plant soil fumigation with methyl bromide (MB) is a standard practice for controlling soil-borne diseases especially for strawberry diseases. However, the application of MB will be forbidden in China in the year 2015. For this reason, a bio-product named Kangdi 3 was tested as an alternative to MB in strawberry greenhouses in Mancheng (Hebei Province) and Donggang (Liaoning province), China in 2005 and 2006. Methyl bromide at a normal dosage of 500 kg/hm2 and Kangdi 3 at three dosages of 750, 1500 and 2250 kg/hm2 were tested. Plots without any treatment were used as the control. During the growing stage, assessments were made on fungal communities in rhizosphere, growth status of strawberry, the disease levels on roots as well as the yields. Results showed that Kangdi 3 significantly reduced the quantity of fungi and the disease index, while enhancing strawberry growth and the yields compared with the untreated control. Therefore, Kangdi 3 is a great potential substitute for methyl bromide to control replant diseases in strawberry.

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

    Science.gov (United States)

    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.

  15. Recent trends in atmospheric methyl bromide: analysis of post-Montreal Protocol variability

    Directory of Open Access Journals (Sweden)

    S. A. Yvon-Lewis

    2009-03-01

    Full Text Available The atmospheric methyl bromide (CH3Br burden has declined in recent years, in response to the phaseout of agricultural and structural fumigation consumption under the amendments to the Montreal Protocol. The timing and magnitude of this decrease represents an opportunity to examine our current understanding of the CH3Br budget, the phaseout schedule, and recent estimates of interannual variability in biomass burning and global OH. In this study, simulations obtained from a time-dependent global model of atmospheric CH3Br emissions and uptake are compared to observations from the NOAA flask network. The model includes an updated global methyl bromide source inventory that includes biofuel combustion emissions estimated at 6.1±3 Gg yr−1 globally. The phaseout of CH3Br production for agricultural uses began in 1998, concurrent with the pulse in biomass burning associated with the 1998 El Niño. The combined effects of three factors (biomass burning, global OH, and anthropogenic phaseout appear to explain most of the observed atmospheric methyl bromide trend over the 1997–2005 period. The global budget remains imbalanced, with a large missing source. These results suggest that more than 80% of the missing source does not exhibit significant interannual variability during the phaseout period and, therefore, does not result from underestimating agricultural CH3Br emissions.

  16. Replacing methyl bromide in annual strawberry production with glucosinolate-containing green manure crops.

    Science.gov (United States)

    Lazzeri, Luca; Baruzzi, Gianluca; Malaguti, Lorena; Antoniacci, Loredana

    2003-09-01

    The use of biocidal green manure crops is an agronomic technique for amending soil with fresh organic matter containing volatile compounds active in controlling some soil-borne pests and diseases. Two new selections of the Brassicaceae family were cultivated, incorporated before planting strawberries and tested as an alternative to fumigation with methyl bromide. Two biocidal green manure crops (Brassica juncea L sel ISCI20, Eruca sativa Mill cv Nemat) containing glucosinolate-myrosinase systems, a conventional green manure (barley), untreated soil and a fumigated control were evaluated during two seasons. The effect of these soil management systems on subsequent strawberry performance was evaluated by monitoring yield and plant growth parameters. In both years, biocidal plant green manure treatments led to a fruit yield lower than with methyl bromide, but higher than with conventional green manure or untreated soil. These results confirm the good prospects for biocidal green manures, not only as an environmentally friendly alternative to methyl bromide in conventional agriculture, but also in organic agriculture as an alternative to conventional green manure crops.

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

    Science.gov (United States)

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

    2000-08-01

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

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

    Science.gov (United States)

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

    1988-01-01

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

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

    Science.gov (United States)

    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.

  20. The Effect of Ozonation Process on Bromide-Containing Groundwaters in Bandung Area and Its Surroundings

    Directory of Open Access Journals (Sweden)

    Mindriany Syafila

    2012-11-01

    Full Text Available Disinfection process was applied as the last step of the water treatment to kill pathogenic bacteria in the water. However, according to several studies, the ozonation disinfection process could form undesired by-products. One of the by-products potentially affecting human life is bromate produced from bromide ionic-containing water. This study was carried out to examine the effect of raw water characteristics and pH on bromate formation. Also, the performance of bromate formation for a period of exposure time was analyzed. Raw waters taken from four different areas around Bandung were exposed to ozone introduced to a reactor with a flow rate of 2 L/min. The pH of the raw waters varied from 4, 7 to 10. The results show that there was no evidence of an initial bromide ion concentration, whereas a change in pH value gives a significantly different outcome. In acidic condition (pH of 4 the bromate formation tends to decrease, whereas when the pH value increases to a pH of 10, the bromate formation increases. Therefore, for drinking water with a neutral pH, when bromide ions are detected in the raw water, the drinking water may be toxic due to the presence of bromate.

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

    Science.gov (United States)

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

    2015-08-21

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

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

    Science.gov (United States)

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

    2010-11-01

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

  3. Prostate cancer and toxicity from critical use exemptions of methyl bromide: Environmental protection helps protect against human health risks

    Directory of Open Access Journals (Sweden)

    Budnik Lygia T

    2012-01-01

    Full Text Available Abstract Background Although ozone-depleting methyl bromide was destined for phase-out by 2005, it is still widely applied as a consequence of various critical-use-exemptions and mandatory international regulations aiming to restrict the spread of pests and alien species (e.g. in globalized transport and storage. The withdrawal of methyl bromide because of its environmental risk could fortuitously help in the containment of its human toxicity. Methods We performed a systematic review of the literature, including in vitro toxicological and epidemiological studies of occupational and community exposure to the halogenated hydrocarbon pesticide methyl bromide. We focused on toxic (especially chronic or carcinogenic effects from the use of methyl bromide, on biomonitoring data and reference values. Eligible epidemiological studies were subjected to meta-analysis. Results Out of the 542 peer reviewed publications between 1990-2011, we found only 91 referring to toxicity of methyl bromide and 29 using the term "carcinogenic", "neoplastic" or "mutagenic". Several studies provide new additional data pertaining to the mechanistic aspects of methyl bromide toxicity. Few studies have performed a detailed exposure assessment including biomonitoring. Three evaluated epidemiological studies assessed a possible association between cancer and methyl bromide. Overall, exposure to methyl bromide is associated with an increased risk of prostate cancer OR, 1.21; 95% CI (0,98-1.49, P = 0.076. Two epidemiological studies have analyzed environmental, non-occupational exposure to methyl bromide providing evidence for its health risk to the general public. None of the epidemiological studies addressed its use as a fumigant in freight containers, although recent field and case reports do refer to its toxic effects associated with its use in shipping and storage. Conclusions Both the epidemiological evidence and toxicological data suggest a possible link between methyl

  4. Comparison of pinaverium bromide, manganese chloride and D600 effects on electrical and mechanical activities in rat uterine smooth muscle.

    Science.gov (United States)

    Mironneau, J; Lalanne, C; Mironneau, C; Savineau, J P; Lavie, J L

    1984-02-10

    The effects of pinaverium bromide, were compared with those of D600 and manganese chloride (Mn), on membrane potentials, ionic currents and isometric contractions in uterine smooth muscle strips from pregnant rats. Pinaverium bromide (10(-7) - 10(-6) M) depressed twitch contractions and K-contractures within 15-20 min while D600 (2 X 10(-6) M) and Mn (10(-3) M) abolished both contractions. D600 and pinaverium bromide were more potent inhibitors in K-depolarized preparations than in polarized tissues. At a supramaximal dose (10(-5) M), pinaverium bromide decreased the rate of rise, amplitude, and rate of repolarization of the action potential, and prolonged the potential duration. The inward Ca current was depressed and the reduction in Cai was responsible for the decrease in K current. Pinaverium bromide (10(-5) M) depressed the myometrial contractions induced in Ca-free solution by acetylcholine (10(-4) M) and by prolonged membrane depolarizations. Mn (2.5 X 10(-3) M) only reduced the Ach-induced contraction and D600 (10(-5) M) had no effect on intracellular Ca stores. The results indicate that pinaverium bromide has Ca channel blocking properties similar to those of currently used Ca antagonists; it may also exert an effect to depress contractions supported by intracellular Ca release. PMID:6325214

  5. Hydrolysis of Racemic Ibuprofen n-Octyl Ester Catalyzed by Lipase in Cetyl Trimethyl Ammonium Bromide/p-Octyl Polyethylene Glycol Phenyl Ether Microemulsion-based Gel%十六烷基三甲基溴化铵/聚乙二醇辛基苯基醚微乳液凝胶固定化脂肪酶催化水解消旋布洛芬辛酯

    Institute of Scientific and Technical Information of China (English)

    李斌; 王晶; 裘立群; 宋少芳

    2014-01-01

    初步考察了水溶液中影响十六烷基三甲基溴化铵(CTAB)/聚乙二醇辛基苯基醚(TX-100)微乳液凝胶(MBG)固定化脂肪酶催化水解消旋布洛芬辛酯的主要因素.结果表明,CTAB/TX-100 MBG固定化脂肪酶在水溶液中能顺利催化水解S-构型布洛芬辛酯生成S-构型布洛芬.随TX-100在EM(正丁醇与TX-100的混合物)中含量的增加,反应转化率(X)逐渐增大,而产物中S-构型布洛芬的对映体过量值(eei)有少许的降低;随凝胶含水量的增加,X及ee;均呈钟罩形变化,二者最大值时对应的凝胶水含量为27.3%,且磷酸缓冲溶液对二者的影响要比溶解明胶的水大;X在反应初期(16 h内)增加明显,随反应时间的继续延长增加缓慢,24h后趋于平衡,而eei随反应时间的延长呈逐渐降低的趋势;随固定化脂肪酶重复使用次数的增多,X在前3次中降幅不大,后几次中降幅逐渐增大,eei则呈逐渐稍微降低的趋势,重复使用10次后,二者分别降低了36.55%和0.52%.

  6. 溴化十六烷基三甲铵与邻{2-[α- (2-羟基-磺酸苯偶氮)-亚苄基]肼基}苯甲酸的显色反应及其应用%Colour Reaction of Cetyl Trimethyl Ammonium Bromide with o-{2-[α-(2-Hydroxy-5-sulphophenylazo)-   benzylidene]hydrazine}benzoic Acid and Its Application

    Institute of Scientific and Technical Information of China (English)

    迟燕华; 庄稼; 白进伟

    2001-01-01

    @@ 1 引言 表面活性剂在工农业生产及人类日常生活中的应用越来越广泛,研究表明活性剂在环境中的转化、迁移及对生理过程的影响以及对它的测定是十分有意义的课题,常规测定阳离子表面活性剂的方法有称重、萃取、滴定、电张力、交流示波极谱法、气相色谱法、光化学等,但这些方法大多操作繁琐、复杂,并且灵敏度不高.实验发现邻{2-[α-(2-羟基- 磺酸苯偶氮)-亚苄基]肼基}苯甲酸(ZCN)与溴化十六烷基三甲铵(CTMAB)在pH 5.0的缓冲溶液中相互作用,致使UV光谱发生变化,最大吸收峰红移80~110 nm,具有较好的对比性.同时发现此法具有较高的灵敏度和较宽的线性范围.

  7. 2-[(Diisopropylthiophosphorylamino]pyridinium tetrafluoroborate

    Directory of Open Access Journals (Sweden)

    Christian Holzhacker

    2012-06-01

    Full Text Available The title compound, C11H20N2PS+·BF4−, is a salt of 2-(diisopropylthiophosphorylaminopyridine, a chelating bidentate ligand that furnishes an S atom as a soft donor and a pyridine N atom as a hard atom for transition-metal complexation. The title salt crystallizes with two formula units in the asymmetric unit. The two independent cations are protonated at the pyridine N atoms and have the S atoms syn-oriented to them so as to form bent intramolecular N—H...S hydrogen bonds, one of which one is bifurcated by involving also an N—H...F interaction. The phosphorylamino NH groups form near linear hydrogen bonds to proximal tetrafluoroborate anions. Five weak C—H...F and three weak C—H...S interactions link the constituents into a three-dimensional framework. As a result of the crystal packing, the two cations differ notably in conformation, as can be seen from the S—P—N—C torsion angles of −18.7 (1° in the first and −35.1 (1° in the second cation.

  8. 4-tert-Butyl­pyridinium chloride–4,4′-(propane-2,2-di­yl)bis­(2,6-di­methyl­phenol)–toluene (2/2/1)

    OpenAIRE

    Alastair J. Nielson; Waters, Joyce M.

    2014-01-01

    In the title solvated salt, C9H14N+·Cl−·C19H24O2·0.5C7H7, two mol­ecules of 4,4′-(propane-2,2-di­yl)bis­(2,6-di­methyl­phenol) are linked via O—H⋯Cl hydrogen bonds to two chloride ions, each of which is also engaged in N—H⋯Cl hydrogen bonding to a 4-tert-butyl­pyridinium cation, giving a cyclic hydrogen-bonded entity centred at 1/2, 1/2, 1/2. The toluene solvent mol­ecule resides in the lattice and resides on an inversion centre; the disorder of the methyl group requires it to have a site-occ...

  9. 4-tert-Butyl-pyridinium chloride-4,4'-(propane-2,2-di-yl)bis-(2,6-di-methyl-phenol)-toluene (2/2/1).

    Science.gov (United States)

    Nielson, Alastair J; Waters, Joyce M

    2014-04-01

    In the title solvated salt, C9H14N(+)·Cl(-)·C19H24O2·0.5C7H7, two mol-ecules of 4,4'-(propane-2,2-di-yl)bis-(2,6-di-methyl-phenol) are linked via O-H⋯Cl hydrogen bonds to two chloride ions, each of which is also engaged in N-H⋯Cl hydrogen bonding to a 4-tert-butyl-pyridinium cation, giving a cyclic hydrogen-bonded entity centred at 1/2, 1/2, 1/2. The toluene solvent mol-ecule resides in the lattice and resides on an inversion centre; the disorder of the methyl group requires it to have a site-occupancy factor of 0.5. No crystal packing channels are observed. PMID:24826127

  10. Measurement and computation of movement of bromide ions and carbofuran in ridged humic-sandy soil.

    Science.gov (United States)

    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.

  11. ACCIDENTAL SUBCUTANEOUS INJECTION OF VECURONIUM BROMIDE IN A PATIENT WITH BURNS

    Directory of Open Access Journals (Sweden)

    Usha Dev

    2014-10-01

    Full Text Available BACKGROUND AND OBJECTIVES: In patients with burn injury drug pharmacology will be altered and this poses special anaesthetic challenge when an subcutaneous injection of a non- depolarizing muscle relaxant occurs in such a patient. Small studies remain an important source of knowledge and hence this study aims to provide information on the anaesthetic management in a case of accidental subcutaneous injection of vecuronium bromide in a burns patient. PRESENTATION, DIAGNOSIS & MANAGEMENT: A 22 year young male with 4 days old hot water induced grade 1 burns involving 45% of body surface area was posted for burns dressing. Anaesthesia was induced with propofol and vecuronium bromide through an external jugular vein to aid tracheal intubation. As the patient was not anaesthetized even after 10 minutes routine check lead to the discovery of fullness at the tip of the intravenous catheter indicating an extravasation of the drugs. Hence the other external jugular vein was cannulated and the patient induced and intubated using propofol, sevoflurane, nitrous oxide and oxygen. The action of vecuronium outlasted the duration of surgery. So the patient continued to receive support of mechanical ventilation with nitrous oxide and oxygen. It took 130 minutes for the clinical signs of recovery from the muscle relaxant to manifest. He was then reversed & extubated with subsequent good recovery. CONCLUSION: Subcutaneous injection of these drugs poses problems of delayed onset of action and prolonged duration of action. In an inadvertent accidental subcutaneous 0.1 mg/kg vecuronium bromide injection in a patient with 4 day old 45% burns showed delayed onset action and prolonged neuromuscular blockade due to subcutaneous deposition of the drug which was managed with mechanical ventilation .The reported resistance to the action of NDMR drugs in patient with burns was not noticed here probably because of the age of the thermal injury.

  12. Efficient SN2 fluorination of primary and secondary alkyl bromides by copper(I) fluoride complexes

    KAUST Repository

    Liu, Yanpin

    2013-11-11

    Copper(I) fluoride complexes ligated by phenanthroline derivatives have been synthesized and structurally characterized by X-ray crystallography. These complexes adopt as either ionic or neutral forms in the solid state, depending on the steric bulkiness of the substituent groups on the phenanthroline ligands. These complexes react with primary and secondary alkyl bromides to produce the corresponding alkyl fluorides in modest to good yields. This new method is compatible with a variety of important functional groups such as ether, thioether, amide, nitrile, methoxyl, hydroxyl, ketone, ester, and heterocycle moieties. © 2013 American Chemical Society.

  13. Radiation Induced Formation of Acrylated Palm Oil Nanoparticles using Cetyltrimethylammonium Bromide Microemulsion System

    International Nuclear Information System (INIS)

    In this study, we report the preparation of Acrylated Palm Oil (APO) nanoparticles using aqueous Cetyltrimethylammonium bromide (CTAB) microemulsion system. This microemulsion system which contains the dispersed APO nano droplets was subjected to the gamma irradiation to induce the formation of the crosslinked APO nanoparticle. After irradiation at higher doses, the size of APO nanoparticles was transformed from a submicron-sized to a nano-sized of the particles. Size decreasing might be due to the intermolecular and the intramolecular crosslinking reactions of the APO nanoparticles during the irradiation process. (author)

  14. Promotion of hexadecyltrimethyleamine bromide to the damage of Alexandrium sp. LC3 by cupric glutamate

    Institute of Scientific and Technical Information of China (English)

    LI Hao; MIAO Jin-lai; CUI Feng-xia; LI Guang-you

    2006-01-01

    The effect of hexadecyltrimethyleamine bromide (HDTMAB) on the removal of A lexandrium sp. LC3 under cupric glutamate stress was investigated. Toxic effect of cupric glutamate on A lexandrium sp. LC3 was significantly promoted in the presence of HDTMAB, especially at 3.0 cmc of HDTMAB. It was found that the sulfhydryl group content of the cell decreased, while the malonaldehyde content and membrane permeability increased when Alexandrium sp. LC3 was treated with HDTMAB and cupric glutamate complex, compared with cupric glutamate alone. The data suggest that HDTMAB might stimulate the damage of A lexandrium sp. LC3 by enhancing the membrane permeability.

  15. Efficient Stille cross-coupling reaction using aryl chlorides or bromides in water.

    Science.gov (United States)

    Wolf, Christian; Lerebours, Rachel

    2003-09-19

    An efficient Stille cross-coupling reaction using a variety of aryl halides in neat water has been developed. Employing palladium-phosphinous acid catalyst [(t-Bu)(2)P(OH)](2)PdCl(2) allows formation of biaryls from aryl chlorides and bromides in good to high yields. Functional groups such as ketones and nitriles are tolerated, and organic cosolvents are not required. The air stability and solubility in water of the palladium complexes used in this study facilitate operation of the coupling reaction and product isolation. The feasibility of catalyst recycling has also been demonstrated. PMID:12968920

  16. Highly stable, luminescent core-shell type methylammonium-octylammonium lead bromide layered perovskite nanoparticles.

    Science.gov (United States)

    Bhaumik, Saikat; Veldhuis, Sjoerd A; Ng, Yan Fong; Li, Mingjie; Muduli, Subas Kumar; Sum, Tze Chien; Damodaran, Bahulayan; Mhaisalkar, Subodh; Mathews, Nripan

    2016-06-01

    A new protocol for the synthesis of a highly stable (over 2 months under ambient conditions) solution-processed core-shell type structure of mixed methylammonium-octylammonium lead bromide perovskite nanoparticles (5-12 nm), having spherical shape, color tunability in the blue to green spectral region (438-521 nm) and a high photoluminescence quantum yield (PLQY) of up to 92% is described. The color tunability, high PLQY and stability are due to the quantum confinement imparted by the crystal engineering associated with core-shell nanoparticle formation during growth. PMID:27165565

  17. Rapid Consumption of Low Concentrations of Methyl Bromide by Soil Bacteria

    OpenAIRE

    Hines, Mark E.; Crill, Patrick M; Varner, Ruth K.; Talbot, Robert W; Shorter, Joanne H.; Kolb, Charles E.; Harriss, Robert C.

    1998-01-01

    A dynamic dilution system for producing low mixing ratios of methyl bromide (MeBr) and a sensitive analytical technique were used to study the uptake of MeBr by various soils. MeBr was removed within minutes from vials incubated with soils and ∼10 parts per billion by volume of MeBr. Killed controls did not consume MeBr, and a mixture of the broad-spectrum antibiotics chloramphenicol and tetracycline inhibited MeBr uptake by 98%, indicating that all of the uptake of MeBr was biological and by...

  18. Nitrate ion photolysis in thin water films in the presence of bromide ions.

    Science.gov (United States)

    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.

  19. Cytotoxicity evaluation of Clinacanthus nutans through dimethylthiazol diphenyltetrazolium bromide and neutral red uptake assays

    OpenAIRE

    Vajrabhaya, La-Ongthong; Korsuwannawong, Suwanna

    2016-01-01

    Objectives: The aim of this study was to compare the results of dimethylthiazol diphenyltetrazolium bromide (MTT) and neutral red uptake (NRU) assays of Clinacanthus nutans cytotoxicity. Materials and Methods: Mouse fibroblast (L929) cells were exposed to 0.01%, 0.1%, 0.25%, and 0.5% (W/V) C. nutans in a 96-cluster-well-culture plate for 24 h. The cell viability after exposure to C. nutans was determined by MTT and NRU assays in separate tissue culture plates. The two assays were compared thr...

  20. Ethidium bromide transport across Mycobacterium smegmatis cell-wall: correlation with antibiotic resistance

    OpenAIRE

    Couto Isabel; Ramos Jorge; Rodrigues Liliana; Amaral Leonard; Viveiros Miguel

    2011-01-01

    Abstract Background Active efflux systems and reduced cell-wall permeability are considered to be the main causes of mycobacterial intrinsic resistance to many antimicrobials. In this study, we have compared the Mycobacterium smegmatis wild-type strain mc2155 with knockout mutants for porins MspA (the main porin of M. smegmatis) and MspC, the efflux pump LfrA (the main efflux pump system of M. smegmatis) and its repressor LfrR for their ability to transport ethidium bromide (EtBr) on a real-t...

  1. Generation, spectroscopy, and structure of cyanoformyl chloride and cyanoformyl bromide, XC(O)CN.

    Science.gov (United States)

    Pasinszki, Tibor; Vass, Gábor; Klapstein, Dieter; Westwood, Nicholas P C

    2012-04-01

    Cyanoformyl chloride and cyanoformyl bromide, XC(O)CN (X = Cl and Br), have been investigated in the gas phase by UV photoelectron and mid-infrared spectroscopies. The ground-state geometries of the neutral molecules have been obtained from quantum-chemical calculations at the B3LYP and CCSD(T) levels using the aug-cc-pVTZ basis set. The individual spectroscopies provide a detailed investigation into the vibrational and electronic character of the molecules and are supported by quantum-chemical calculations. The results are compared to data for structurally and chemically related molecules.

  2. Bromine and bromide in rainfall, cloud, stream and groundwater in the Plynlimon area of mid-Wales

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Bromine in rainfall, cloud water, stream water and groundwater were measured in the upper River Severn catchments at Plynlimon in mid-Wales using two analytical procedures for bromide determination: a colorimetric method and, later, ion chromatography. Discrepancies between the methods indicated that the colorimetric method was measuring more than just bromide so it was "dissolved labile bromine" (DLBr (Neal et al., 2007. This paper reports the variation in DLBr and bromide across the Plynlimon region and assesses the differences between these two measures. The average DLBr concentration in the streams ranges between 18.3 and 27.8 µg l−1 compared with a rainfall average concentration of 15.6 µg l−1. The corresponding bromide concentrations in the streams are 13.8–18.6 µg l−1 and 13.2 µg l−1 in rainfall. For cloud water, throughfall and stemflow, DLBr concentrations are an order of magnitude higher than in rainfall and the concentrations are strongly correlated with chloride. Average values of bromide in rainfall and cloud water are similar to those of DLBr and are strongly correlated with chloride: unfortunately, no bromide measurements were taken in throughfall and stemflow. These results indicate that marine aerosol inputs are high and that the DLBr in these inputs is dominated by bromide. For cloud water, DLBr was correlated with dissolved organic carbon (DOC as well as with chloride; hence, there may well be an organic-associated component. Within the streams draining the forested areas, DLBr increases with time as DOC increases. DLBr concentrations in the streams are correlated with DOC in most cases and, to a lesser degree, with chloride. However, for bromide there is no correlation with DOC, but a weak correlation with chloride remains and the gradient is higher than for the DLBr case. Increasing concentrations of both DLBr and DOC may well reflect the wetting up of the catchments as transpiration diminshes as the trees age

  3. Using prechloramination to control trihalomethanes formation in River Huang water with high bromide

    Institute of Scientific and Technical Information of China (English)

    TAO Hui; CHEN Wei; LIN Tao; LIU Cheng; CHEN Jie; LI Gui-bai

    2008-01-01

    An effective technology in controlling trihalomethanes (THMs)formation in the case of large amounts of bromide presenting wag proposed,and the water of River Huang seriously polluted by bromide in winter in Tianjin City wag studied.The THMs formation characteristics during prechloramination using preformed chloramines and convened chloramines were studied through jar tests.Results show that,in prechloramination process,the formation of THMs by preformed chloramines is very few,while that by converted chloramines is a little higher.And the formation of THMs,especially Br-substituted THMs,increases with tIle increase of time and Cl2:N ratio as well as the decrease of pH.The result obtained in a pilot plant shows that compared with preehlorination,the prechlommination process can efficiendy control the formation of THMs,especially the Br-substituted species.With equal chlorine dosage.the prechloramination can maintain a hrser chlorine residue which offers a larger CT value than prechlorination.

  4. Moving away from methyl bromide: political economy of pesticide transition for California strawberries since 2004.

    Science.gov (United States)

    Mayfield, Erin N; Norman, Catherine Shelley

    2012-09-15

    We examine the progress of the phaseout of the use of the pesticide methyl bromide in the production of California field strawberries. This phaseout is required under the Montreal Protocol and has been contentious in this sector, which receives exemptions from the schedule initially agreed under the treaty, and in international negotiations over the future of the Protocol. We examine the various ex-ante predictions of the impacts on growers, consumers and trade patterns in light of several years of declining allocations under the Critical Use provisions of the Protocol and the 2010 approval of iodomethane for use in California and subsequent 2012 withdrawal of this alternative from the US market. We find that, contrary to ex-ante industry claims, the years of declining methyl bromide use have been years of rising yields, acreage, exports, revenues and market share for California growers, even when faced with a global recession and increased imports from Mexican growers who retain the right to use the chemical under the Protocol. This has implications for the Protocol as a whole and for the remainder of the US phaseout of this chemical in particular. PMID:22575205

  5. Model prediction uncertainty of bromide and pesticides transport in laboratory column

    Science.gov (United States)

    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.

  6. Recent trends in atmospheric methyl bromide: analysis of post-Montreal Protocol variability

    Directory of Open Access Journals (Sweden)

    S. A. Yvon-Lewis

    2009-08-01

    Full Text Available The atmospheric methyl bromide (CH3Br burden has declined in recent years, in response to the phaseout of agricultural and structural fumigation consumption under the amendments to the Montreal Protocol. The timing and magnitude of this decrease represents an opportunity to examine our current understanding of atmospheric CH3Br and its budget, response to the phaseout, and response to interannual variability in biomass burning and global OH. In this study, simulations obtained from a time-dependent global model of atmospheric CH3Br emissions and uptake are compared to observations from the NOAA flask network. The model includes a detailed gridded ocean model coupled to a time-dependant atmospheric 2-box model. The phaseout of CH3Br production for agricultural uses began in 1998, concurrent with the pulse in biomass burning associated with the 1998 El Niño. The combined effects of three factors (biomass burning, global OH, and anthropogenic phaseout appear to explain most of the observed atmospheric methyl bromide variability over the 1997–2008 period. The global budget remains imbalanced, with a large missing source indicated. The missing source does not exhibit a systematic decline during the phaseout period, and therefore, is not the result of significantly underestimating non-QPS agricultural CH3Br emissions. The model results suggest that the oceans should be less undersaturated than before the phaseout began.

  7. Thermodynamics of micellization of hexadecyltrimethylammonium bromide in propylene glycol-water mixture: A conductivity study

    Directory of Open Access Journals (Sweden)

    Janošević-Ležaić Aleksandra M.

    2014-01-01

    Full Text Available Micellization of hexadecyltrimethylammonium bromide (syn. cetyltrimethylammonium bromide, CTAB in propylene glycol-water (30% v/v binary mixture, as well as the thermodynamic properties of the resulting micelles, were investigated by electrical conductivity measurements. The conductivity data were used to determine both the critical micellar concentration (CMC and the micellar ionization degree (α of CTin the temperature range 298.2-310.2 K. The equilibrium model of micelle formation was applied in order to obtain the thermodynamic parameters (the standard molar Gibbs free energy, ΔGm0, enthalpy, ΔHm0 and entropy, ΔSm0 of the micellization process. The values of DGm0 and DHm0 were found to be negative at all investigated temperatures, while the values of ΔSm0 were positive and became more positive as temperature increased. A linear dependence between ΔSm0 and ΔHm0, i.e. an enthalpy-entropy compensation effect, was observed. [Projekat Ministarstva nauke Republike Srbije, br. 172015

  8. Natural Oxidation of Bromide to Bromine in Evaporated Dead Sea Brines

    Science.gov (United States)

    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 pHacidic 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.

  9. Modelling of a Tracer experiment (Bromide) at the lysimeter Wagna/Austria with MIKE-SHE

    Science.gov (United States)

    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.

  10. Modeling Water Flow and Bromide Transport in a Two-Scale-Structured Lignitic Mine Soil

    Science.gov (United States)

    Dusek, J.; Gerke, H. H.; Vogel, T.; Maurer, T.; Buczko, U.

    2008-12-01

    Two-dimensional single- and dual-permeability simulations are used to analyze water and solute fluxes in heterogeneous lignitic mine soil at a forest-reclaimed mine spoil heap. The soil heterogeneity on this experimental site "Barenbrucker Hohe" resulted from inclined dumping structures and sediment mixtures that consist of sand with lignitic dust and embedded lignitic fragments. Observations on undisturbed field suction- cell lysimeters including tracer experiments revealed funneling-type preferential flow with lateral water and bromide movement along inclined sediment structures. The spatial distribution of soil structures and fragment distributions was acquired by a digital camera and identified by a supervised classification of the digital profile image. First, a classical single-domain modeling approach was proposed with spatially variable scaling factors inferred from image analyses. In the next step, a two-continuum scenario was constructed to examine additional effects of nonequilibrium on the flow regime. The scaling factors used for the preferential flow domain are here obtained from the gradient of the grayscale images. So far, the single domain scenarios failed to predict the bromide leaching patterns although water effluent could be described. Dual-permeability model allows the incorporation of structural effects and can be used as a tool to further testing other approaches that account for structure effects. The numerical study suggests that additional experiments are required to obtain better understanding of the highly complex transport processes on this experimental site.

  11. Pressure-Induced Structural and Optical Properties of Organometal Halide Perovskite-Based Formamidinium Lead Bromide.

    Science.gov (United States)

    Wang, Lingrui; Wang, Kai; Zou, Bo

    2016-07-01

    Organometal halide perovskites (OMHPs) are attracting an ever-growing scientific interest as photovoltaic materials with moderate cost and compelling properties. In this Letter, pressure-induced optical and structural changes of OMHP-based formamidinium lead bromide (FAPbBr3) were systematically investigated. We studied the pressure dependence of optical absorption and photoluminescence, both of which showed piezochromism. Synchrotron X-ray diffraction indicated that FAPbBr3 underwent two phase transitions and subsequent amorphization, leading directly to the bandgap evolution with redshift followed by blueshift during compression. Raman experiments illustrated the high pressure behavior of organic cation and the surrounding inorganic octahedra. Additionally, the effect of cation size and the different intermolecular interactions between organic cation and inorganic octahedra result in the fact that FAPbBr3 is less compressible than the reported methylammonium lead bromide (MAPbBr3). High pressure studies of the structural evolution and optical properties of OMHPs provide important clues in optimizing photovoltaic performance and help to design novel OMHPs with higher stimuli-resistant ability. PMID:27321024

  12. Acute hepatitis after starting pinaverium bromide in a patient taking mirtazapine.

    Science.gov (United States)

    Tak, Sandeep; Tak, Shubhanjali

    2014-01-01

    A 56-year-old man presented with chronic abdominal pain. He had been evaluated extensively in the recent past undergoing upper gastrointestinal endoscopy, colonoscopy and CT scan of the abdomen with normal results. The provisional diagnosis of irritable bowel syndrome was performed and pinaverium bromide was started. The patient had pre-existing hypertension, a major depressive disorder and gastro-oesophageal reflux disease. He had been taking nebivolol and pantoprazole for several years and mirtazapine for the last 1 year. The patient developed nausea, vomiting and anorexia after 5 days of starting pinaverium bromide. Investigations revealed marked elevation of liver enzymes and bilirubin. He was negative for HIV, HBSAg, anti-hepatitis C virus, IgM for hepatitis A virus, hepatitis E virus, antinuclear antibody and antimitochondrial antibody. An ultrasound showed mild hepatomegaly with hypoechoic echo texture; the rest of scan was normal. Pinaverium and mirtazapine were stopped immediately. The patient was treated symptomatically and his liver profile returned to normal after 4 weeks. PMID:25015163

  13. The influence of nitrogen oxides on the activation of bromide and chloride in salt aerosol

    Science.gov (United States)

    Bleicher, S.; Buxmann, J. C.; Sander, R.; Riedel, T. P.; Thornton, J. A.; Platt, U.; Zetzsch, C.

    2014-04-01

    Experiments on salt aerosol with different salt contents were performed in a Teflon chamber under tropospheric light conditions with various initial contents of nitrogen oxides (NOx = NO + NO2). A strong activation of halogens was found at high NOx mixing ratios, even in samples with lower bromide contents such as road salts. The ozone depletion by reactive halogen species released from the aerosol, was found to be a function of the initial NOx mixing ratio. Besides bromine, large amounts of chlorine have been released in our smog chamber. Time profiles of the halogen species Cl2, Br2, ClNO2, BrNO2 and BrO, ClO, OClO and Cl atoms were simultaneously measured by various techniques (chemical ionization mass spectrometry, differential optical absorption spectrometry coupled with a multi-reflection cell and gas chromatography of hydrocarbon tracers for Cl and OH, employing cryogenic preconcentration and flame ionization detection). Measurements are compared to calculations by the CAABA/MECCA 0-D box model, which was adapted to the chamber conditions and took the aerosol liquid water content and composition into account. The model results agree reasonably with the observations and provide important information about the prerequisites for halogen release, such as the time profiles of the aerosol bromide and chloride contents as well as the aerosol pH.

  14. The application of activation analysis for the control of bromide accumulation in vegetable

    International Nuclear Information System (INIS)

    Soil desinfestation with methyl bromide increases the uptake of bromine by plants. The natural bromine content of crops and fruits was found in the range of 1 up to 5 ppm in fresh weight. The highest acceptable level is 50 ppm in fresh weight. By using methyl bromide as a soil fumigant, a bromine accumulation was found in the crops to levels up to 20-500 ppm in fresh matter. The uptake of bromine differs in various parts of the vegetable crops. The highest bromine concentration could be observed in the leaves. The bromine uptake by plants depends on (a) the fumigation technique (applied amounts, reaction time, date of cultivation); (b) the growing conditions (soil type, climate and irrigation); (c) the plants (species, rotation, harvesting time etc.). The INAA is a simple and rapid method to analyse bromine in vegetables within a wide range using Br-80 and Br-82. Since several years this method has also been used to control imported crops. The samples were subjected to a short irradiation (1-3 minutes at 1013ncm-2sec-1). After the decay time of a few minutes the induced activity was measured with a Ge(Li) detector coupled to a multi-channel analyzer. The limit of detection varies between 0.1 and 0.5 ppm Br in fresh vegetable samples. (T.G.)

  15. Bromide as a tracer for studying water movement and nitrate displacement in soils: comparison with stable isotope tracers; Bromid als Tracer zur Untersuchung der Wasserbewegung und der Nitratverlagerung in Boeden: Vergleich mit stabilisotopen Tracern

    Energy Technology Data Exchange (ETDEWEB)

    Russow, R.; Knappe, S. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Bad Lauchstaedt (Germany). Sektion Bodenforschung

    1999-02-01

    Tracers are an ideal means of studying water movement and associated nitrate displacement. Often bromide is preferred as a tracer because it is considered a representative tracer for water and because, being a conservative tracer (i.e. not involved in chemical and biological soil processes), it can be used for studying anion transport in soils. Moreover, it is less expensive and easier to measure than the stable isotopes deuterium and {sup 15}N. Its great advantage over radioactive tracers (e.g. tritium), which outweighs their extreme sensitivity and ease of measurement and which it has in common with stable isotopes, is that it does not require radiation protection measures. However, there are also constraints on the use of bromide as a tracer in soil/water/plant systems. Our own studies on different soils using D{sub 2}O, bromide and [{sup 15}N]-nitrate in lysimeters suggest that the above assumptions on bromide tracers need not always be valid under conditions as they prevail in biologically active soils. As the present paper shows, these studies permit a good assessment of the possibilities and limits to these tracers. [Deutsch] Fuer die Untersuchung der Wasserbewegung sowie der daran gekoppelten Nitrat-Verlagerung ist der Einsatz von Tracern das Mittel der Wahl. Dabei wird Bromid als Tracer haeufig bevorzugt, da es allgemein als ein repraesentativer Tracer fuer Wasser und als konservativer Tracer (nicht involviert in chemische und biologische Bodenprozesse) zur Untersuchung des Anionentransportes in Boeden angesehen wird und es gegenueber den stabilen Isotopen Deuterium und {sup 15}N billiger und einfacher zu bestimmen ist. Gegenueber den radioaktiven Tracern (z.B. Tritium), die zwar sehr empfindlich und einfach messbar sind, besteht der grosse Vorteil, dass, wie bei den stabilen Isotopen, keine Strahlenschutzmassnahmen ergriffen werden muessen. Es gibt jedoch auch einschraenkende Hinweise fuer die Verwendung von Bromid als Tracer im System Boden

  16. The Research on Programmable Control System of Lithium-Bromide Absorption Refrigerating Air Conditioner Based on the Network

    Directory of Open Access Journals (Sweden)

    Sun Lunan

    2016-01-01

    Full Text Available This article regard the solar lithium-bromide absorption refrigerating air conditioning system as the research object, and it was conducting adequate research of the working principle of lithium bromide absorption refrigerating machine, also it was analyzing the requirements of control system about solar energy air conditioning. Then the solar energy air conditioning control system was designed based on PLC, this system was given priority to field bus control system, and the remote monitoring is complementary, which was combining the network remote monitoring technology. So that it realized the automatic control and intelligent control of new lithium bromide absorption refrigerating air conditioning system with solar energy, also, it ensured the control system can automatically detect and adjust when the external conditions was random changing, to make air conditioning work effectively and steadily, ultimately ,it has great research significance to research the air conditioning control system with solar energy.

  17. Combination of ozonation and photocatalysis for purification of aqueous effluents containing formic acid as probe pollutant and bromide ion.

    Science.gov (United States)

    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.

  18. [Effects of bromide and ferric ions on formation of tri-halomethanes during disinfection of drinking water by chlorine].

    Science.gov (United States)

    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.

  19. Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Nava, N., E-mail: tnava@imp.mx; Likhanova, N. V. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Olivares-Xometl, O. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria Quimica (Mexico); Flores, E. A. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Lijanova, I. V. [CIITEC, Instituto Politecnico Nacional (Mexico)

    2011-11-15

    The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission {sup 57}Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ({alpha}-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

  20. Enhanced Degradation of the Volatile Fumigant-Nematicides 1,3-D and Methyl Bromide in Soil

    OpenAIRE

    Ou, L.-T.

    1998-01-01

    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 ci...

  1. Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

    International Nuclear Information System (INIS)

    The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission 57Fe Mössbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite (α-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

  2. Spectral and Non Radiative Decay Studies of Lead Di Bromide Single Crystals by Mode Matched Thermal Lens Technique.

    Science.gov (United States)

    Rejeena, I; Lillibai, B; Thomas, V; Nampoori, V P N; Radhakrishnan, P

    2016-07-01

    In the present paper, the investigations on the non radiative decay mechanism, optical band gap determination from absorption spectroscopic studies and fluorescence emission by photo luminescence techniques using different excitation wavelengths on gel derived lead di bromide single crystals are reported. Non radiative decay of the sample is studied using high sensitive dual beam mode matched thermal lens technique. For the thermal lensing experiment the crystal in solution phase is incorporated with rhodamine 6G dye for enhancing the absorption of the crystal sample. The thermal diffusivity of lead di bromide is determined using the probe beam intensity v/s time measurements. PMID:27165040

  3. Protective effect of testosterone on cognitive deficits induced by ethidium bromide in experimental model of multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Sallahadin Feizollah

    2015-11-01

    Full Text Available Background: Multiple Sclerosis (MS is a neurodegenerative disease of the central nervous system (CNS. The hippocampus is a vital center for learning and memory; it is extremely vulnerable to neurodegenerative diseases. The male hormones could be neuroprotective for the CNS. The current study is an attempt to investigate the effect of testosterone on learning and spatial memory following the demyelination of CA1 area by the injection of ethidium bromide in the rats' hippocampus. Methods: This experimental study has been conducted on healthy rats in the faculty of science of the Urmia University from September 2013 to February 2015. For demyelination in all previously gonadectomized healthy rats, 3µl ethidium bromide was injected into the CA1 area of rats by stereotaxic surgery. In addition, the treatment groups received 1µl testosterone (6µg/µl during a 20-day timeframe on a daily basis after demyelination by the ethidium bromide. The control groups had no drug injection. The process of the learning and spatial memory of the rats were closely monitored by the radial Maze. The demyelination and remyelination in the hippocampus were checked by the myelin-specific coloring (Luxol fast blue and Cresyl violet. Results: The histological results suggest that the testosterone is capable of minimizing the destructive impacts of ethidium bromide in the treatment group as well as enhancing the remyelination process. In the group treated by testosterone, the percentage of the pyknotic cells 20 days after demyelination induction, represented a significant reduction compared to that of ethidium bromide group (P=0.008. The behavioral studies analyses show that the amount of the food finding time in those groups received ethidium bromide was significantly longer than those of the control groups (P=0.001. Furthermore, the application of the testosterone in the treatment groups reduced the extent of demyelination while the memory impairment induced by the

  4. Physicochemical and thermodynamic characterization of N-alkyl-N-methylpyrrolidinium bromides and its aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zawadzki, Maciej, E-mail: mzawadzki@ch.pw.edu.pl; Królikowska, Marta; Lipiński, Paweł

    2014-08-10

    Highlights: • The aqueous solutions of bromide-based ionic liquids have been studied. • The synthesis and basic thermal characterization of pure IL have been done. • The density, dynamic viscosity, SLE and VLE have been determined. • The experimental data have been correlated using appropriate equations. - Abstract: This work is a continuation of our research of ionic liquids to investigate the physicochemical and thermodynamic properties of (ionic liquid + water) binary mixtures as a novel alternative working pair for the absorption heat pump cycle. In this work, a series of organic salts: N-propyl-N-methyl-pyrrolidinium bromide, [C{sub 1}C{sub 3}PYR]Br; N-butyl-N-methylpyrrolidinium, [C{sub 1}C{sub 4}PYR]Br and N-pentyl-N-methylpyrrolidinium bromide, [C{sub 1}C{sub 5}PYR]Br have been synthesized. The structures of new compounds have been confirmed using NMR spectra and elementary analysis. The basic thermal characterization of pure ILs, including temperature and enthalpy of phase transition (T{sub tr}, Δ{sub tr}H), temperature and enthalpy of melting (T{sub m,} Δ{sub m}H) have been measured using a differential scanning microcalorimetry technique (DSC). Decomposition temperature of the tested ILs were detected by the simultaneous TG/DTA experiments. The effect of temperature on the density (ρ) and dynamic viscosity (η) is reported over a wide temperature range from 298.15 to 343.15 K at ambient pressure. From experimental density data, the excess molar volumes (V{sup E}) were calculated and correlated using Redlich–Kister equation. The isothermal vapour–liquid phase equilibria (VLE) have been measured by an ebulliometric method at wide temperature range from 328.15 to 368.15 K and pressure up to 85 kPa. Experimental data have been correlated by means of NRTL equation. The solid–liquid phase equilibria (SLE) for the tested binary mixtures have been determined over whole composition range using dynamic method. The NRTL equation using parameters

  5. Nanosized sustained-release pyridostigmine bromide microcapsules: process optimization and evaluation of characteristics

    Directory of Open Access Journals (Sweden)

    Tan Q

    2013-02-01

    Full Text Available Qunyou Tan,1,* Rong Jiang,3,* Meiling Xu,2,4,* Guodong Liu,5,* Songlin Li,1 Jingqing Zhang21Department of Thoracic Surgery, Institute of Surgery Research, Daping Hospital, Third Military Medical University, 2Medicine Engineering Research Center, Chongqing Medical University, 3Stem Cells and Tissue Engineering Research, Chongqing Medical University, 4Department of Pharmacy, Chongqing Emergency Medical Center, 5Eighth Department, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, People’s Republic of China*These authors contributed equally to this workBackground: Pyridostigmine bromide (3-[[(dimethylamino-carbonyl]oxy]-1-methylpyridinium bromide, a reversible inhibitor of cholinesterase, is given orally in tablet form, and a treatment schedule of multiple daily doses is recommended for adult patients. Nanotechnology was used in this study to develop an alternative sustained-release delivery system for pyridostigmine, a synthetic drug with high solubility and poor oral bioavailability, hence a Class III drug according to the Biopharmaceutics Classification System. Novel nanosized pyridostigmine-poly(lactic acid microcapsules (PPNMCs were expected to have a longer duration of action than free pyridostigmine and previously reported sustained-release formulations of pyridostigmine.Methods: The PPNMCs were prepared using a double emulsion-solvent evaporation method to achieve sustained-release characteristics for pyridostigmine. The preparation process for the PPNMCs was optimized by single-factor experiments. The size distribution, zeta potential, and sustained-release behavior were evaluated in different types of release medium.Results: The optimal volume ratio of inner phase to external phase, poly(lactic acid concentration, polyvinyl alcohol concentration, and amount of pyridostigmine were 1:10, 6%, 3% and 40 mg, respectively. The negatively charged PPNMCs had an average particle size of 937.9 nm

  6. An innovative experimental design reveals the spatial correlation between landuse, irrigation properties, and bromide leaching

    Science.gov (United States)

    Schwen, A.; Yang, Y.; Walton, J.; Wendroth, O.

    2012-04-01

    Understanding the relationship between leaching of pesticides and soil hydraulic properties under different land use conditions is critical to our understanding of the flow of water and solutes in soils and efforts to model these flow characteristics. One problem inherent in the measurement of solute leaching in field experiments is the considerable high natural spatial variability of flow-controlling soil properties. Thus, analyzing treatment effects based on the mean and the variance of observations can become obsolete if there is a huge inherent variance in the set of measurements. Moreover, no spatial range of influence can be derived from the observations. To overcome this limitation, the spatial covariance and cross-variance between measurements was used as decision and quality criteria in the present study. This study aims to demonstrate that focussing on the spatial covariance of observations and considering their spatial process can provide a measure of spatial representativity or scale-specific variance. We introduce a novel experimental scheme, where the treatments are arranged in a scale-dependent manner. In a field trial in Lexington, Kentucky, bromide leaching under two contrasting land use systems (no-till agricultural crops vs. pasture) was compared. After surface application of tracer solution (KBr), the experimental field was irrigated using different time-delays (1, 4 and 24 hours) as well as two different irrigation amounts and two different intensities. At the end, the KBr-concentration in the soil profile was determined using auger samplings. The data was correlated with the applied boundary conditions by spatial statistical methods such as semivariograms, cross-semivariograms and spectral analysis. Our results show distinct differences in the leaching behaviour between the two analyzed land uses with an deeper infiltration in the no-till agricultural field. This can be partly related to a higher initial soil water content in this treatment

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

    Directory of Open Access Journals (Sweden)

    Ferguson GT

    2013-03-01

    Full Text Available Gary T Ferguson,1 Mo Ghafouri,2 Luyan Dai,2 Leonard J Dunn31Pulmonary Research Institute of Southeast Michigan, Livonia, MI, USA; 2Boehringer Ingelheim Pharmaceuticals, Inc, Ridgefield, CT, USA; 3Clinical Research of West Florida, Inc, Clearwater, FL, USABackground: 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

  8. Copper-catalysed N-arylation of arylsulfonamides with aryl bromides and aryl iodides using KF/Al2O3

    Indian Academy of Sciences (India)

    Rahman Hosseinzadeh; Mahmood Tajbakhsh; Maryam Mohadjerani; Mohammad Alikarami

    2010-03-01

    An efficient synthesis of -arylsulfonamides with a variety of aryl bromides, aryl iodides and heteroaryl bromides using KF/Al2O3 as a suitable base, CuI as an inexpensive catalyst and ,'-dimethylethylenediamine (,'-DMEDA) as an effective ligand is described.

  9. Carbon nanotubes as an efficient hole collector for high voltage methylammonium lead bromide perovskite solar cells.

    Science.gov (United States)

    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. PMID:26646241

  10. Increase in mitotic recombination in diploid cells of Aspergillus nidulans in response to ethidium bromide

    Directory of Open Access Journals (Sweden)

    Tânia C.A. Becker

    2003-01-01

    Full Text Available Ethidium bromide (EB is an intercalating inhibitor of topoisomerase II and its activities are related to chemotherapeutic drugs used in anti-cancer treatments. EB promotes several genotoxic effects in exposed cells by stabilising the DNA-enzyme complex. The recombinagenic potential of EB was evaluated in our in vivo study by the loss of heterozygosity of nutritional markers in diploid Aspergillus nidulans cells through Homozygotization Index (HI. A DNA repair mutation, uvsZ and a chromosome duplication DP (II-I were introduced in the genome of tested cells to obtain a sensitive system for the recombinagenesis detection. EB-treated diploid cells had HI values significantly greater than the control at both concentrations (4.0 x 10-3 and 5.0 x 10-3 mM. Results indicate that the intercalating agent is potentially capable of inducing mitotic crossing-over in diploid A. nidulans cells.

  11. Behavior of aqueous Tetrabutylammonium bromide - a combined approach of microscopic simulation and neutron scattering

    CERN Document Server

    Bhowmik, Debsindhu

    2016-01-01

    Aqueous solution of tetrabutylammonium bromide is studied by quasi-elastic neutron scattering, to give information on the dynamic modes involving the ions present. Using a careful combination of two techniques, time-of-flight (TOF) and neutron spin echo (NSE), we de- couple the dynamic information in both the coherently and incoherently scattered signal from this system. We take advantage of the different intensity ratio of the two signals, as detected by each of the techniques, to achieve this decoupling. By using heavy water as the sol- vent, the tetrabutylammonium cation is the only hydrogen-containing species in the system and gives rise to a significant incoherent scattered intensity. The dynamic analysis of the incoherent signal (measured by TOF) leads to a translational diffusion coefficient of the cation as that is in good agreement with previous NMR, neutron scattering and tracer diffusion measurements. The dynamic analysis of the coherent signal observed at wave-vectors < 0.6 angstrom^(-1) (measu...

  12. Copper bromide vapor brightness amplifiers with 100 kHz pulse repetition frequency

    Science.gov (United States)

    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.

  13. Spectroscopic study one thiosemicarbazone derivative with ctDNA using ethidium bromide as a fluorescence probe.

    Science.gov (United States)

    Geng, Shaoguang; Wu, Qing; Shi, Lei; Cui, Fengling

    2013-09-01

    In this study, a thiosemicarbazone derivative (E)-2-((1,4-dihydroxy-9,10-anthraquinone-2-yl)methylene)-N-(4-fluorophenyl)hydrazinecarbothioamide (DAFPT) was synthesized, and the interaction of DAFPT with calf thymus DNA (ctDNA) was explored using ethidium bromide (EB) as a fluorescence probe. The binding mode between DAFPT and ctDNA was investigated by UV absorption spectroscopy, fluorescence spectroscopy and molecular docking. The fluorescence quenching mechanism of EB-ctDNA by DAFPT might be a combined quenching type. Thermodynamic parameters showed that the reaction was spontaneous. According to ionic strength, fluorescence polarization and melting temperature (T(m)) curve results, DAFPT-ctDNA interaction was groove binding. The molecular modeling results indicated that DAFPT could slide into the A-T rich region of ctDNA. PMID:23769721

  14. Lithium bromide absorption machines: Pressure drop and mass transfer in solutions conical sheets

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, E. [Escuela Universitaria de Ingenieria Tecnica Industrial, U.P.M., Ronda de Valencia 3, Madrid 28012 (Spain); Izquierdo, M. [Instituto de Ciencias de la Construccion Eduardo Torroja. C.S.I.C., Serrano Galvache 4, Madrid 28033 (Spain); Lizarte, R. [Escuela Politecnica Superior, Universidad Carlos III de Madrid, Avda. de la Universidad 30, Madrid 28911 (Spain); Marcos, J.D. [Escuela Tecnica Superior de Ingenieria Industrial, U.N.E.D., Juan del Rosal 12, Madrid 28040 (Spain)

    2009-07-15

    Adiabatic vapour absorption in conical liquid sheets is studied with a view to use in air conditioning. The sheets consist in a lithium bromide aqueous solution sprayed at mass flow rates ranging from 0.0078 to 0.0116 kg/s (28-42 kg/h). The experimental results show that the deformation rate associated with conical sheet development has a significant effect on absorption, with 60% of the total reached by the time the liquid sheet disintegrates, 4 ms after injection. In the conical sheet configuration, about 150 g of vapour are absorbed per kJ of solution flow work. The vapour absorption rate per chamber absorption volume, in turn, is found to be over 1 g/s l in absorption chambers 75 mm long or less. (author)

  15. [Investigation of the oxidation reaction of O3 with bromide ion in aqueous solution].

    Science.gov (United States)

    Yu, Xiao-Ting; Zhang, Jia-Hui; Pan, Xun-Xi; Zhang, Ren-Xi; Hou, Hui-Qi

    2012-09-01

    The reaction mechanism of O3 with bromide ion in aqueous solution was studied by ion chromatography and UV-Vis spectrometry instruments. Ion chromatography analysis showed that only 10% of Br- which was oxidized by ozone was formed into bromate ion. The results demonstrated that the final products of the oxidation reaction were identified as Br2 and Br3- except for BrO3-. The formation of Br3- which was yielded from the reaction of Br2 with Br- was the major process in the reaction of Br attacked by O3. The characteristic absorption spectrum of Br3- with an absorption peak at 260 nm was also investigated. The results may provide helpful information about the mechanism of the oxidation reaction of Br- with O3 and fate of Br- or its derivatives in the environment by the oxidation processes.

  16. 2-(4-Methylsulfanylphenyl-1H-benzimidazol-3-ium bromide

    Directory of Open Access Journals (Sweden)

    Mohamed Ziaulla

    2011-02-01

    Full Text Available In the cation of the title compound, C14H13N2S+·Br−, the essentially planar benzimidazole system (r.m.s. deviation = 0.0082 Å is substituted with a 4-methylsulfanylphenyl ring. The dihedral angle between the benzimidazole system and the 4-methylsulfanylphenyl ring is 2.133 (2°. The crystal structure is characterized by strong and highly directional intermolecular N—H...Br hydrogen bonds involving the bromide ion. Moreover, C—H...S interactions result in chains of molecules along the c axis. The supramolecular assembly is further stabilized by π–π stacking interactions between the benzimidazole system and 4-methylsulfanylphenyl rings [centroid–centroid distance = 3.477 (4 Å].

  17. Solubilization Using Some Novel N-Methyl Diethanolammonium Bromide Cationic Surfactants

    International Nuclear Information System (INIS)

    A novel series of N-methyl diethanolammonium bromide cationic surfactants was used as solubilizing agent for nonpolar substrate (paraffin oil) at 25 degree C. The results of solubilization measurements showed good ability for the used surfactants towards solubilizing paraffin oil in aqueous medium. The results showed also, that the chemical structure of the soluble plays an important rule in its solubilization. Several factors were found to influence the extent of solubilization, which are: number of alkyl chains within surfactant molecule, symmetry of molecules and chain length of hydrophobic parts. The results were rationalized by the Kraft point and HLB values of the used surfactants. Furthermore, solubilization curves showed the steady state solubilization of each surfactant used

  18. Improved hydrogen evolution on glassy carbon electrode modified with novel Pt/cetyltrimethylammonium bromide nanoscale aggregates

    Institute of Scientific and Technical Information of China (English)

    Jahan-Bakhsh Raoof; Sayed Reza Hosseini; Seyedeh Zeinab Mousavi-Sani

    2015-01-01

    A novel, cost‐effective, and simple electrocatalyst based on a Pt‐modified glassy carbon electrode (GCE), using cetyltrimethylammonium bromide (CTAB) as a cationic surfactant, is reported. Am‐phiphilic CTAB molecules were adsorbed on GCE by immersion in a CTAB solution. The positively charged hydrophilic layer, which consisted of small aggregates of average size less than 100 nm, was used for accumulation and complexation of [PtCl6]2− anions by immersing the electrode in K2PtCl6 solution. The modified electrode was characterized using scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, impedance spectroscopy, and electrochemical methods. The electrocatalytic activity of the Pt particles in the hydrogen evolution reaction (HER) was investigat‐ed. The results show that the CTAB surfactant enhances the electrocatalytic activity of the Pt parti‐cles in the HER in acidic solution.

  19. Spectroscopic probe of the competitive binding of ethidium bromide and neomycin to DNA

    Science.gov (United States)

    Pal, Medini Kanta; Ghosh, Jimut Kanti

    1995-03-01

    The three spectroscopic changes of ethidium bromide (EB) on its binding to DNA, namely red-shift of the νmax, enhancement of fluorescence and induced dichroism are utilized to study the competitive binding of neomycin (NMC) and EB to DNA. Reversion of νmax, decrease in fluorescence and reduction of dichroism of DNA-EB on addition of NMC shows that the binding of NMC and EB to DNA is competitive in nature, over a limited concentration of the polymer. The binding constant of EB-DNA falls from 4.00 × 10 6 to 2.27 × 10 4 1 mol -1 in the presence of added NMC.

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

    Science.gov (United States)

    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. PMID:26797656

  1. The matlockite-type praseodymium(III oxide bromide PrOBr

    Directory of Open Access Journals (Sweden)

    Pia Talmon-Gros

    2011-12-01

    Full Text Available The crystal structure of the praseodymium(III oxide bromide, PrOBr, can be best described with layers of agglomerated square antiprisms [PrO4Br4]9−. These slabs are stacked along the c axis and linked via two different secondary contacts between Pr3+ and Br−. The Pr3+ cations occupy the Wyckoff site 2c with 4mm symmetry and carry four O2− 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 Pr3+ cations, the oxide anions are located at the Wyckoff position 2a with site symmetry overline{4}m2 and have four Pr3+ cations as neighbours, defining a tetrahedron.

  2. Bio-conjugated silver nanoparticles: from Ocimum sanctum and role of cetyltrimethyl ammonium bromide.

    Science.gov (United States)

    Zaheer, Zoya; Rafiuddin

    2013-08-01

    In this paper we have reported the spectrophotometeric and transmission electron microscopic (TEM) data to the shape-directing role of cetyltrimethylammonium bromide (CTAB) on the green extra-cellular synthesis of bio-conjugated Ag-nanoparticles using Ocimum sanctum leaves extract. TEM images revealed that the nanoparticles are mostly spherical (average particle size ranged from 18 to 35nm) with some truncated triangular nanoplates, aggregated in a beautiful manner to yield locket-like silver and capped by a thin layer of biomolecules of O. sanctum, whereas nanoparticles are highly poly-dispersed in presence of CTAB. The shape and position of wavelength maxima strongly depends on the reaction time, [leaves extract] and [CTAB]. The visual observations also suggest that the prefect transparent silver sol becomes turbid in presence of CTAB after some time. PMID:23524081

  3. Synthesis and photoluminescence of semiconductor quantum dots/cetyltrimethylammonium bromide vesicle core/shell nanostructures

    International Nuclear Information System (INIS)

    The synthesis and photoluminescence properties of the SiC quantum dots (QDs)/cetyltrimethylammonium bromide (CTAB) multilayered vesicle core/shell nanostructures are reported. The Coulomb attraction force between the negatively charged surface of the QD and the positively charged ionized CTAB molecules drives the formation of the core/shell nanostructures. The outer CTAB molecules are demonstrated to form multilayered vesicles. The core/shell nanostructures exhibit strong near-UV photoluminescence which is supposed to stem from the outer CTAB vesicles. This novel semiconductor QD/vesicle core/shell structures can serve as a prototype for studying the QD–organic molecule interaction as well as the building block for constructing nanoscale devices.

  4. Fluorescence studies on the interaction of ethidium bromide with duplex, triplex and quadruplex DNA structures

    Institute of Scientific and Technical Information of China (English)

    孙雪光; 曹恩华; 何裕建; 秦静芬

    1999-01-01

    Under different conditions, oligonucleotides can form several alternative DNA structures such as duplex, triplex and quadruplex. All these structures can interact with ethidium bromide (EB) and make its fluorescence intensity change. The fluorescence spectra and other related parameters provided by static fluorescence techniques showed that the interaction mechanisms between EB and these structures were not always the same. Among them, B type duplex and triplex DNA adopt an intercalative mode when binding to the EB, which has a relatively high efficiency of energy transfer and the fluorescence of EB cannot be quenched easily. While for the parallel duplex DNA, the interaction mode is an outside binding in which energy transfer can hardly happen and its fluorescence intensity as well as Stern-Volmer constant is almost the same to the free EB. For the quadruplex, the binding mechanism to EB is more complex. Results from the energy transfer and quenching studies indicate that the two interaction modes note

  5. Suzuki Reaction of Aryl Bromides Using a Phosphine-Free Magnetic Nanoparticle-Supported Palladium Catalyst

    Institute of Scientific and Technical Information of China (English)

    Nghia T. BUI; Trung B. DANG; Ha V. LE; Nam T. S. PHAN

    2011-01-01

    A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g.The catalyst was characterized using X-ray diffraction,scanning electron microscopy,transmission electron microscopy,vibrating sample magnetometry,thermogravimetric analysis,Fourier transform infrared,atomic absorption spectrophotometry,and nitrogen adsorption.The immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid.The recovery of catalyst was simply by magnetic decantation in the presence of a magnet.The immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity.No leaching of active palladium species into the reaction solution was detected.

  6. Tetrabutylammonium Bromide (TBABr-Based Deep Eutectic Solvents (DESs and Their Physical Properties

    Directory of Open Access Journals (Sweden)

    Rizana Yusof

    2014-06-01

    Full Text Available Density, viscosity and ionic conductivity data sets of deep eutectic solvents (DESs formed by tetrabutylammonium bromide (TBABr paired with ethlyene glycol, 1,3-propanediol, 1,5-pentanediol and glycerol hydrogen bond donors (HBDs are reported. The properties of DES were measured at temperatures between 303 K and 333 K for HBD percentages of 66.7% to 90%. The effects of HBDs under different temperature and percentages are systematically analyzed. As expected, the measured density and viscosity of the studied DESs decreased with an increase in temperature, while ionic conductivity increases with temperature. In general, DESs made of TBABr and glycerol showed the highest density and viscosity and the lowest ionic conductivity when compared to other DESs. The presence of an extra hydroxyl group on glycerol in a DES affected the properties of the DES.

  7. INTERACTION OF POLY(SODIUM SULFODECYL METHACRYLATE) WITH CETYLTRIMETHYL AMMONIUM BROMIDE IN AQUEOUS SOLUTION

    Institute of Scientific and Technical Information of China (English)

    Cong-hua Lu; Chuan-qiou Luo; Wei-xiao Cao

    2003-01-01

    The interaction of poly(sodium sulfodecyl methacrylate) (PSSM) with cetyltrimethyl ammonium bromide (CTAB)was studied. It was found that the precipitate formed from PSSM and CTAB will be dissolved by excessive CTAB, resultingin the appearance of two maxima of the solution viscosity at the molar ratio (CTAB/-SO3-) of ≈ 0.68 and ≈ 1.30,respectively. The first one is related closely to the aggregation of polymer chains via CTAB molecules and the second oneshould be ascribed to the formation of the mixed micelles comprising surfactant and the polymer's hydrophobic chains. Theeffect of NaCl on the viscosity, the transmittance of the aqueous solution and the solubility of oil-soluble dye (dimethylyellow) in the mixed system were also investigated.

  8. Direct electrochemistry and electrocatalysis of myoglobin in dodecyltrimethylammonium bromide film modified carbon ceramic electrode

    Institute of Scientific and Technical Information of China (English)

    Yuan Zhen Zhou; Hui Wang; She Ying Dong; An Xiang Tian; Zhi Xian He; Bin Chen

    2011-01-01

    Direct electrochemistry and electrocatalysis of myoglobin (Mb) were studied with Mb immobilized on dodecyltrimethylammonium bromide (DTAB) film modified carbon ceramic (CC) electrode. Cyclic voltammetry showed a pair of well-defined and nearly reversible redox peaks of Mb (FeⅡ/FeⅢ) at about -0.3 V vs. SCE (pH = 6.98). The currents of the redox peak were linear to scan rate, and rate constant (Ks) was estimated to be 3.03 s-1. The formal potential (E01) of Mb in the DTAB/CC electrodes shifted linearly with pH with a slope of-36.44 mV/pH, implying that the electron transfer between DTAB and CC electrodes is accompanied by proton transportation. The immobilized Mb exhibited excellent electrocatalytic response to the reduction of hydrogen peroxide (H2O2).

  9. Multimetallic catalysed cross-coupling of aryl bromides with aryl triflates

    Science.gov (United States)

    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

  10. Boron-doped diamond anodic oxidation of ethidium bromide: Process optimization by response surface methodology

    International Nuclear Information System (INIS)

    Highlights: ► Boron-doped diamond was used to degrade ethidium bromide. ► The process was optimized by a central composite rotatable design coupled with response surface methodology. ► Applied current is proved to be the most significant variable. ► A possible reaction sequence involving all the detected byproducts was proposed. - Abstract: The degradation of ethidium bromide (EtBr), a DNA intercalating pollutant, had been studied by anodic oxidation on boron-doped diamond (BDD) electrode under galvanostatic conditions. A central composite rotatable design coupled with response surface methodology was implemented to optimize the various operating parameters involved, among initial pH, flow rate, applied current and supporting electrolyte concentration, on the treatment efficiency; the latter was assessed in terms of color removal, COD removal, specific energy consumption and general current efficiency. Of the four parameters involved, applied current had a considerable effect on all the response factors. Optimum EtBr degradation was achieved by applying a current of 0.90 A, 9.0 mM Na2SO4, flow rate of 400 ml min−1 and pH 6.2 at 60 min of electrolysis, being reduced color by 80.2% and COD by 29.7%, with an energy consumption of 398.32 kW h (kg COD)−1 and a general current efficiency of 10.1%. Under these optimized conditions, EtBr decays followed pseudo first-order kinetics. Moreover, HPLC analysis of the BDD-treated solution allowed the detection of a number of reaction intermediates, and a possible reaction sequence involving all the detected byproducts was proposed for the electrochemical oxidation of EtBr on BDD anode.

  11. Carbon nanotubes as an efficient hole collector for high voltage methylammonium lead bromide perovskite solar cells

    Science.gov (United States)

    Li, Zhen; Boix, Pablo P.; Xing, Guichuan; Fu, Kunwu; Kulkarni, Sneha A.; Batabyal, Sudip K.; Xu, Wenjing; Cao, Anyuan; Sum, Tze Chien; Mathews, Nripan; Wong, Lydia Helena

    2016-03-01

    A high open circuit voltage (VOC) close to 1.4 V under AM 1.5, 100 mW cm-2 conditions is achieved when carbon nanotubes (CNTs) are used as a hole conductor in methyl ammonium lead bromide (MAPbBr3) perovskite solar cells. Time-resolved photoluminescence and impedance spectroscopy investigations suggest that the observed high VOC is a result of the better charge extraction and lower recombination of the CNT hole conductor. Tandem solar cells with all perovskite absorbers are demonstrated with a MAPbBr3/CNT top cell and a MAPbI3 bottom cell, achieving a VOC of 2.24 V in series connection. The semitransparent and high voltage MAPbBr3/CNT solar cells show great potential for applications in solar cell windows, tandem solar cells and solar driven water splitting.A high open circuit voltage (VOC) close to 1.4 V under AM 1.5, 100 mW cm-2 conditions is achieved when carbon nanotubes (CNTs) are used as a hole conductor in methyl ammonium lead bromide (MAPbBr3) perovskite solar cells. Time-resolved photoluminescence and impedance spectroscopy investigations suggest that the observed high VOC is a result of the better charge extraction and lower recombination of the CNT hole conductor. Tandem solar cells with all perovskite absorbers are demonstrated with a MAPbBr3/CNT top cell and a MAPbI3 bottom cell, achieving a VOC of 2.24 V in series connection. The semitransparent and high voltage MAPbBr3/CNT solar cells show great potential for applications in solar cell windows, tandem solar cells and solar driven water splitting. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06177f

  12. Thallium bromide chloride (TlBrxCl1-x) nuclear radiation detector

    International Nuclear Information System (INIS)

    Thallium bromide (TlBr) has been studied as an X- and gamma-ray detector material and relatively good spectrometric performances have been obtained from the detectors. However, the energy resolution of the TlBr detectors is limited by the relatively low resistivity of the crystals. Thallium bromide chloride (TlBrxCl1-x) is a mixed crystal of TlBr and thallium chloride (TlCl). TlBr0.8Cl0.2 crystals have been grown by the traveling molten zone method (TMZ) from purified materials. Nuclear radiation detectors have been fabricated from the grown TlBr0.8Cl0.2 crystals and the detector performance has been characterized. Optical transmittance was evaluated in order to characterize bandgap of the grown crystal. The results confirm that the bandgap of TlBr0.8Cl0.2 is wider than the bandgap of TlBr. Leakage currents of the detectors were measured as a function of the bias voltage at room temperature. The resistivity of the TlBr0.8Cl0.2 detector is approximately equal to the resistivity of typical TlBr detector. A TlBr0.8Cl0.2 detector operated at room temperature was irradiated with gamma-rays from 137Cs source. The detector exhibited a clear peak corresponding 662 keV gamma-rays. The resolution obtained by the TlBr0.8Cl0.2 detector, however, was presently not better than the resolution obtained by the typical TlBr detector. (M. Suetake)

  13. Ethidium bromide transport across Mycobacterium smegmatis cell-wall: correlation with antibiotic resistance

    Directory of Open Access Journals (Sweden)

    Couto Isabel

    2011-02-01

    Full Text Available Abstract Background Active efflux systems and reduced cell-wall permeability are considered to be the main causes of mycobacterial intrinsic resistance to many antimicrobials. In this study, we have compared the Mycobacterium smegmatis wild-type strain mc2155 with knockout mutants for porins MspA (the main porin of M. smegmatis and MspC, the efflux pump LfrA (the main efflux pump system of M. smegmatis and its repressor LfrR for their ability to transport ethidium bromide (EtBr on a real-time basis. This information was then correlated with minimum inhibitory concentrations (MICs of several antibiotics in the presence or absence of the efflux inhibitors chlorpromazine, thioridazine and verapamil. Results In the absence of porins MspA and MspC, accumulation of ethidium bromide decreased and the cells became more resistant to several antibiotics, whereas the knockout mutant for the LfrA pump showed increased accumulation of EtBr and increased susceptibility to EtBr, rifampicin, ethambutol and ciprofloxacin. Moreover, the efflux inhibitors caused a reduction of the MICs of streptomycin, rifampicin, amikacin, ciprofloxacin, clarithromycin and erythromycin in most of the strains tested. Conclusions The methodology used in this study demonstrated that porin MspA plays an important role in the influx of quaternary ammonium compounds and antibiotics and that efflux via the LfrA pump is involved in low-level resistance to several antimicrobial drugs in M. smegmatis. The results obtained with this non-pathogenic mycobacterium will be used in future studies as a model for the evaluation of the activity of the same efflux inhibitors on the susceptibility of multidrug resistant strains of Mycobacterium tuberculosis to isoniazid and rifampicin.

  14. The aqueous catanionic system sodium perfluorooctanoate-dodecyltrimethylammonium bromide at low concentration.

    Science.gov (United States)

    López-Fontán, José Luis; Blanco, Elena; Ruso, Juan M; Prieto, Gerardo; Schulz, Pablo C; Sarmiento, Félix

    2007-08-15

    The interaction between sodium perfluorooctanoate (SPFO) and dodecyltrimethylammonium bromide (DTAB) was studied by several methods and it was found strongly synergistic. Above a mole fraction of SPFO in the surfactant mixture (alpha(SPFO))=0.38, the interaction is repulsive and increases with the content of SPFO in both, the overall mixture and micelles, whereas the interaction is attractive if DTAB is in excess. At alpha(SPFO)=0.38 the low miscibility between hydrocarbon and fluorocarbon is counterbalanced by the electrostatic attraction between the opposite charged head groups, and the micelle composition is ideal (i.e., the mole fraction of SPFO in micelles X(SPFO)=alpha(SPFO)=0.38). The solubility of fluorocarbon in hydrocarbon is lower than that of hydrocarbon in fluorocarbon. Micelles of DTAB act as a solvent for SPFO without important structural changes, whilst micelles of SPFO undergo important changes when dissolve DTAB. This asymmetry may be interpreted as caused by the difference in chain length that favors the inclusion of the shorter chain in micelles of the longer surfactant, but disfavors the opposite process. Above X(SPFO)=0.5 there is an excess adsorption of bromide ions on the mixed micelles surface, giving rise to a high zeta potential. Micelles of pure SPFO or pure DTAB show an important energy barrier which prevents micelle flocculation. The inclusion of SPFO in DTAB micelles produces a reduction of the energy barrier, which disappeared when alpha(SPFO)=0.5. This produces the flocculation of micelles giving rise to the formation of a non-birefringent coacervate, which is probably formed by unordered isometric clusters of micelles.

  15. C-N Coupling of nitrogen nucleophiles with aryl and heteroaryl bromides using aminoarenethiolato-copper(I) (pre-)catalyst

    NARCIS (Netherlands)

    Sperotto, Elena; Klink, Gerard P.M. van; Vries, Johannes G. de; Koten, Gerard van

    2010-01-01

    The activity of a library of 2-aminoarenethiolato-copper(I) (CuSAr) (pre-)catalyst was explored in the arylation reaction of amines and N-containing heterocycles with aryl and heteroaryl bromides, respectively. These CuSAr pre-catalysts are thermally stable, are soluble in common organic solvents an

  16. Protective antiviral immune responses to pseudorabies virus induced by DNA vaccination using dimethyldioctadecylammonium bromide as an adjuvant

    NARCIS (Netherlands)

    Rooij, van E.M.A.; Glansbeek, H.L.; Hilgers, L.A.T.; Lintelo, te E.G.; Visser, de Y.E.; Boersma, W.J.A.; Haagmans, B.L.; Bianchi, A.T.J.

    2002-01-01

    To enhance the efficacy of a DNA vaccine against pseudorabies virus (PRV), we evaluated the adjuvant properties of plasmids coding for gamma interferon or interleukin-12, of CpG immunostimulatory motifs, and of the conventional adjuvants dimethyldioctadecylammonium bromide in water (DDA) and sulfoli

  17. Suzuki coupling reactions catalyzed by poly(N-ethyl-4-vinylpyridinium bromide stabilized palladium nanoparticles in aqueous solution

    Directory of Open Access Journals (Sweden)

    2008-04-01

    Full Text Available InIn this work, it was investigated to use of poly(N-ethyl-4-vinylpyridinium bromide stabilized palladium nanoparticles in the Suzuki reaction between phenylboronic acid and aryl halides in aqueous solution. The nanoparticles were isolated and re-used several times with low loss of activity.

  18. FLUORESCENCE SPECTROSCOPIC STUDY OF THE FORMATION OF HYDROPHOBIC MICRODOMAINS IN AQUEOUS-SOLUTIONS OF POLY(ALKYLMETHYLDIALLYLAMMONIUM BROMIDES)

    NARCIS (Netherlands)

    YANG, YJ; ENGBERTS, JBFN

    1991-01-01

    The conformational state of poly(alkylmethyldiallylammonium bromides) was studied in aqueous solutions using pyrene as a fluorescence probe. The results are indicative for the formation of hydrophobic microdomains in the case of several copolymers which possess sufficiently hydrophobic alkyl side ch

  19. Grafting, metham sodium, soil solarization and virtually impermeable films as alternative technologies to methyl bromide for Chinese protected tomatoes

    Institute of Scientific and Technical Information of China (English)

    Han Xuemei; Cao Zhiping; Chen Yunfeng; Chen Guokang; Andrea Camponogara; Yang Hang; Maria Lodovica Gullino

    2009-01-01

    In the frame of the Sino-ltalian Cooperation Program for Environmental Protection,jointly launched in the year 2000 by the Italian Ministry for Environment and Territory and Sea (IMETS) and the China State Environ nental Protection Administration (SEPA),experimental trials were carried out in Qingzhou city (Shandong Prov ince,China) during 2001-2003 to test several methyl bromide alternative methods to control soilborne diseases in greenhouse tomatoes.Grafting tomatoes on resistant rootstock (Lycopersicon lycopersicum×L.hirsutum),metham sodium applied under traditional polyethylene ptastic films,metham sodium applied at low rate under virtually im permeable films and soil solarization combined with biocontrol agents were the alternatives tested and compared to methyl bromide applied under virtually impermeable plastic films too.Collected data show that resistant rootstock (Lycopersicon lycopersicum × L.hirsutum) introduced from Italy is a promising alternative to methyl bromide for to cal tomato cultivars.Metham sodium applied under traditional polyethylene plastic films is an effective alternative Moreover,virtually impermeable.films demonstrate the help to reduce methyl bromide and metham sodium rates.Finally,soil solarization combined with biocontrol agents does not provide satisfactory resuhs in terms of disease control.

  20. High—Speed Analyzing PCR Products of M.tuberculosis Genome Stained by Ethidium Bromide on Microchip Gel Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    金庆辉; 陈继锋; 等

    2002-01-01

    The technique of microchip gel electrophoresis(MCGE) was used to analyze the polymerase chain reaction (PCR) products of M.tuberculosis Genome stained by ethidium bromide,The electrophoretic Process was completed within 3-4 min and the results show that the technique of microchip electrophoresis is a high-speed and high-sensitivity analyzing method.

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

    Directory of Open Access Journals (Sweden)

    Claudia Brandt

    Full Text Available 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.This retrospective cohort study estimated annual lung function decline utilizing longitudinal data for forced expiratory volume in 1 s (FEV1.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.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.

  2. Formation of halogenated organic byproducts during medium-pressure UV and chlorine coexposure of model compounds, NOM and bromide.

    Science.gov (United States)

    Zhao, Quan; Shang, Chii; Zhang, Xiangru; Ding, Guoyu; Yang, Xin

    2011-12-01

    When chlorine is applied before or during UV disinfection of bromide-containing water, interactions between chlorine, bromide and UV light are inevitable. Formation of halogenated organic byproducts was studied during medium-pressure UV (MPUV) and chlorine coexposure of phenol, nitrobenzene and benzoic acid and maleic acid, chosen to represent electron-donating aromatics, electron-withdrawing aromatics, and aliphatic structures in natural organic matter (NOM), respectively. All were evaluated in the presence and absence of bromide. MPUV and chlorine coexposure of phenol produced less total organic halogen (TOX, a collective parameter for halogenated organic byproducts) than chlorination in the dark, and more haloacetic acids instead of halophenols. Increases in TOX were found in the coexposure of nitrobenzene and benzoic acid, but maleic acid was rather inert during coexposure. The presence of bromide increased the formation of brominated TOX but did not significantly affect total TOX formation, in spite of the fact that it reduced hydroxyl radical levels. MPUV and chlorine coexposure of NOM gave a higher differential UV absorbance of NOM and a larger shift to lower molecular weight compounds than chlorination in the dark. However, TOX formation with NOM remained similar to that observed from dark chlorination.

  3. Impact of bromide on halogen incorporation into organic moieties in chlorinated drinking water treatment and distribution systems.

    Science.gov (United States)

    Tan, J; Allard, S; Gruchlik, Y; McDonald, S; Joll, C A; Heitz, A

    2016-01-15

    The impact of elevated bromide concentrations (399 to 750 μg/L) on the formation of halogenated disinfection by-products (DBPs), namely trihalomethanes, haloacetic acids, haloacetonitriles, and adsorbable organic halogen (AOX), in two drinking water systems was investigated. Bromine was the main halogen incorporated into all of the DBP classes and into organic carbon, even though chlorine was present in large excess to maintain a disinfectant residual. Due to the higher reactivity of bromine compared to chlorine, brominated DBPs were rapidly formed, followed by a slower increase in chlorinated DBPs. Higher bromine substitution and incorporation factors for individual DBP classes were observed for the chlorinated water from the groundwater source (lower concentration of dissolved organic carbon (DOC)), which contained a higher concentration of bromide, than for the surface water source (higher DOC). The molar distribution of adsorbable organic bromine to chlorine (AOBr/AOCl) for AOX in the groundwater distribution system was 1.5:1 and almost 1:1 for the surface water system. The measured (regulated) DBPs only accounted for 16 to 33% of the total organic halogen, demonstrating that AOX measurements are essential to provide a full understanding of the formation of halogenated DBPs in drinking waters. In addition, the study demonstrated that a significant proportion (up to 94%) of the bromide in source waters can be converted AOBr. An evaluation of AOBr and AOCl through a second groundwater treatment plant that uses conventional treatment processes for DOC removal produced 70% of AOX as AOBr, with 69% of the initial source water bromide converted to AOBr. Exposure to organobromine compounds is suspected to result in greater adverse health consequences than their chlorinated analogues. Therefore, this study highlights the need for improved methods to selectively reduce the bromide content in source waters.

  4. Melt sonoquenching: an affective process to obtain new hybrid material and achieve enhanced electrochromic performances based on V{sub 2}O{sub 5}/2,4,5-tris(1-methyl- 4-pyridinium)-imidazolide tetrafluoroborate nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Renato S. de; Goulart, Juliana da S.; Miranda, Fabio S.; Ponzio, Eduardo A., E-mail: eaponzio@vm.uff.br [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Instituto de Quimica

    2014-03-15

    Hybrid electrochromic materials are a very important class of compounds, because they enable new and/or better optical and electrochemical properties to be unfolded. This paper reports the synthesis of the new V{sub 2}O{sub 5}.1.26H{sub 2}O([C{sub 3}N{sub 2}(C{sub 6}H{sub 7}N){sub 3}]){sub 0.07} using the combination of two traditional methods, melting quenching and sonochemistry. The new material was characterized by several methods in order to verify the physical and chemical characteristics and its possible use as an electrochromic electrode. The organic guest provokes an interlayer spacing decrease of the inorganic matrix and the electrostatic interaction between the oxo groups of the V{sub 2}O{sub 5} matrix and the pyridinium rings of the organic guest demonstrate a strong interaction. The new hybrid nanostructure presented good reversibility and cyclability during 50 cycles, electrochromic efficiency of 22 cm{sup 2} C{sup -1} (410 nm) and 96 % color retention after 50 cycles of color changing. (author)'.

  5. Crystal structure of tris­[4-(di­methyl­amino)­pyridinium] tris­(oxalato-κ2 O,O′)chromate(III) tetra­hydrate

    Science.gov (United States)

    Makon ma Houga, Noé; Capet, Frédéric; Nenwa, Justin; Bebga, Gouet; Foulon, Michel

    2015-01-01

    In the title hybrid salt, (C7H11N2)3[Cr(C2O4)3]·4H2O, the central CrIII ion of the complex anion (point group symmetry 2) is coordinated by six O atoms from three chelating oxalate(2−) ligands in a slightly distorted octa­hedral coordination sphere. The Cr—O bond lengths vary from 1.9577 (11) to 1.9804 (11) Å, while the chelate O—Cr—O angles range from 82.11 (6) to 93.41 (5)°. The 4-(di­methyl­amino)­pyridinium cations (one situated in a general position and one on a twofold rotation axis) are protonated at the pyridine N atoms. In the crystal, N—H⋯O and O—H⋯O hydrogen bonds link the cations and anions into a three-dimensional network. π–π inter­actions between the pyridine rings of adjacent cations provide additional stabilization of the crystal packing, with the closest centroid-to-centroid distances being 3.541 (1) and 3.575 (1) Å. PMID:26594521

  6. Transport of Alachlor, Atrazine, Dicamba, and Bromide through Silt and Loam Soils

    Science.gov (United States)

    Tindall, J. A.

    2015-12-01

    The herbicides alachlor, atrazine, and dicamba, as well as bromide were applied to soils overlying the High Plains aquifer in Nebraska, to both macropore and non-macropore sites. Three of 6 study areas (exhibiting a high percentage of macropores) were used for analysis of chemical transport. Twelve intact soil cores (30 cm diameter; 40 cm height), were excavated (two each from 0-40 cm and 40-80 cm depths). The first three study areas and soil cores were used to study preferential flow characteristics using dye staining and to determine hydraulic properties; the remaining cores were treated the same as field macropore sites. Two undisturbed experimental field plots, each with a 1 m2 surface area, were established in each of the three macropore study areas. Each preferential plot was instrumented with suction lysimeters, tensiometers, and neutron access tubes - 10 cm increments to 80 cm - and planted in corn. Three study areas that did not exhibit macropores had alachlor, atrazine, and dicamba and bromide disked into the top 15 cm of soil; concentrations were tracked for 120 days - samples were collected on a grid, distributed within 3 plots measuring 50 m x 50 m each. Core samples were collected prior to and immediately after application, and then at 30, 60, and 120 days after application. Each lab core sample was in 15-cm lengths from 0-15 cm, 15-30 cm, 45-60 cm, and 75-90 cm. For areas exhibiting macropores, herbicides had begun to move between 10-15 days after application with concentrations peaking at various depths after heavy rainfall events. Field lysimeter samples showed increases in concentrations of herbicides at depths where laboratory data indicated greater percentages of preferential flowpaths. Concentrations of atrazine, alachlor and dicamba exceeding 0.30, 0.30, and 0.05 μg m1-1 respectively were observed with depth (10-30 cm and 50-70 cm) after two months following heavy rainfall events indicating that preferential flowpaths were a significant

  7. HYOSCINE BUTYL BROMIDE VERSUS DROTAVERINE HYDROCHLORIDE IN ACTIVE STAGE OF LABOUR-A COMPARATIVE STUDY OF RATE OF CERVICAL DILATATION

    Directory of Open Access Journals (Sweden)

    Misha Pepsi

    2014-05-01

    Full Text Available AIM: This study was conducted to compare the rate of cervical dilatation with hyoscine butyl bromide and drotaverine hydrochloride in active stage of labour. MATERIALS AND METHODOLOGY: This prospective study was conducted in the department of Obstetrics and Gynaecology. Inclusion Criteria: 1. All women with initial cervical dilatation of 3 cms. 2. When there is a slow rate of cervical dilatation of less than 1.5 cms per hour or decent of less than 1 cm per hour for nulliparous and if dilatation was less than 2cms per hour for a multigravida. 3. And all singleton and cephalic pregnancies were included in this study. Exclusion Criteria included complications like Antepartum haemorrhage, Breech, C.P.D. In this study 400 women were allocated into two groups to receive either Hyoscine butyl bromide or Drotaverine hydrochloride. Two hours after admission in the active stage of labour, progress of labour was reassessed. If the progress of labour was satisfactory, then the wait and watch policy was adopted. If there was no progress they were administered one of the two drugs. 200 patients were administered 10mg of hyoscine butyl bromide suppositories rectally, (GROUP-1 AND THE OTHER 200 WITH 40mg of drotaverine hydrochloride intravenously (GROUP-2. The progress of labour was monitored by the partogram. Not more than 3 doses of hyoscine butyl bromide were administered. RESULTS: The rate of cervical dilatation was 2 cms per hour in group 1 (Hyoscine butyl bromide as compared to 1cm per hour in group 2 (Drotaverine hydrochloride. The difference in rate of cervical dilatation in both the groups was statistically significant. CONCLUSION: There was significant improvement in the rate of cervical dilatation with Hyoscine butyl bromide group of patients. There was a significant reduction in the duration of active stage of labour, and there was no significant second and third stage complication when these drugs were used. No untoward side effects were noted when

  8. Bromate ion formation in dark chlorination and ultraviolet/chlorination processes for bromide-containing water

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Bormate (BrO3-) is a carcinogenic chemical produced in ozonation or chlorination of bromide-containing water. Although its formation in seawater with or without sunlight has been previously investigated, the formation of bromate in dilute solutions,particularly raw water for water treatment plant, is unknown. In this article, the results of bench scale tests to measure the formation rates of bromate formation in dilute solutions, including de-ionized water and raw water from Yangtze River, were presented in dark chlorination and ultraviolet (UV)/chlorination processes. And the effects of initial pH, initial concentration of NaOCl, and UV light intensity on bromate formation in UV/chlorination of the diluted solutions were investigated. Detectable bromate was formed in dark chlorination of the two water samples with a relatively slow production rate. Under routine disinfecting conditions, the amount of formed bromate is not likely to exceed the national standards (10 μg/L). UV irradiation enhanced the decay of free chlorine, and,simultaneously, 6.6%-32% of Br- was oxidized to BrO3-. And the formation of bromate exhibited three stages: rapid stage, slow stage and plateau. Under the experimental conditions (pH = 4.41-11.07, CCl2= 1.23-4.50 mg/L), low pH and high chlorine concentration favored the generation of bromate. High light intensity promoted the production rate of bromate, but decreased its total generation amount due to acceleration of chlorine decomposition.

  9. Ozone Therapy in Ethidium Bromide-Induced Demyelination in Rats: Possible Protective Effect.

    Science.gov (United States)

    Salem, Neveen A; Assaf, Naglaa; Ismail, Manal F; Khadrawy, Yasser A; Samy, Mohga

    2016-08-01

    Multiple sclerosis, an autoimmune inflammatory disease of the central nervous system, is characterized by excessive demyelination. The study aimed to investigate the possible protective effect of ozone (O3) therapy in ethidium bromide (EB)-induced demyelination in rats either alone or in combination with corticosteroids in order to decrease the dose of steroid therapy. Rats were divided into Group (1) normal control rats received saline, Group (2) Sham-operated rats received saline, Group (3) Sham-operated rats received vehicle (oxygen), Group (4) EB-treated rats received EB, Group (5) EB-treated rats received O3, Group (6) EB-treated rats received methylprednisolone (MP), and Group (7) EB-treated rats received half the dose of MP concomitant with O3. EB-treated rats showed a significant increase in the number of footfalls in the grid walk test, decreased brain GSH, and paraoxonase-1 enzyme activity, whereas brain MDA, TNF-α, IL-1β, INF-γ, Cox-2 immunoreactivity, and p53 protein levels were increased. A significant decline in brain serotonin, dopamine, norepinephrine, and MBP immunoreactivity was also reported. Significant improvement of the above-mentioned parameters was demonstrated with the administration of either MP or O3, whereas best amelioration was achieved by combining half the dose of MP with ozone. PMID:26467344

  10. Photocontrol of Voltage-Gated Ion Channel Activity by Azobenzene Trimethylammonium Bromide in Neonatal Rat Cardiomyocytes.

    Directory of Open Access Journals (Sweden)

    Sheyda R Frolova

    Full Text Available The ability of azobenzene trimethylammonium bromide (azoTAB to sensitize cardiac tissue excitability to light was recently reported. The dark, thermally relaxed trans- isomer of azoTAB suppressed spontaneous activity and excitation propagation speed, whereas the cis- isomer had no detectable effect on the electrical properties of cardiomyocyte monolayers. As the membrane potential of cardiac cells is mainly controlled by activity of voltage-gated ion channels, this study examined whether the sensitization effect of azoTAB was exerted primarily via the modulation of voltage-gated ion channel activity. The effects of trans- and cis- isomers of azoTAB on voltage-dependent sodium (INav, calcium (ICav, and potassium (IKv currents in isolated neonatal rat cardiomyocytes were investigated using the whole-cell patch-clamp technique. The experiments showed that azoTAB modulated ion currents, causing suppression of sodium (Na+ and calcium (Ca2+ currents and potentiation of net potassium (K+ currents. This finding confirms that azoTAB-effect on cardiac tissue excitability do indeed result from modulation of voltage-gated ion channels responsible for action potential.

  11. Pourbaix diagrams for titanium in concentrated aqueous lithium bromide solutions at 25 oC

    International Nuclear Information System (INIS)

    Research highlights: → The titanium solubility range increases slightly with increasing Br- activity. → The passivation area decreases slightly with increasing Br- activity. → Immunity area increases slightly with increasing Br- activity. → The titanium immunity disappears in the presence of titanium hydrides. → TiH2 is the stable species at low potentials in the presence of titanium hydrides. - Abstract: Pourbaix diagrams (electrode potential-pH diagrams) for Ti-Br--H2O system at 25 oC in the absence and presence of titanium hydrides were developed in 400, 700, 850, and 992 g/L LiBr solutions. The diagrams were compared with the simple Ti-H2O system at 25 oC. Comparison of the simple Ti-H2O system with the diagrams of the Ti-Br--H2O system at 25 oC showed that the titanium solubility range in the acid, neutral, and weak alkaline areas of the diagrams extended slightly to both higher pH values and potentials with increasing bromide ion activity and decreasing water activity.

  12. Influence of Low Cetyltrimethylammonium Bromide Concentration on the Interactions and Properties of Hemoglobin with Acyclovir

    Institute of Scientific and Technical Information of China (English)

    LIU Tian-Qing; GUO Rong

    2006-01-01

    The effects of cetyltrimethylammonium bromide (CTAB) on the properties of hemoglobin (Hb) at low CTAB concentration were studied in Hb/acyclovir/CTAB system by the methods of UV-Vis spectrum, fluorescence, zeta potential, conductivity and negative-staining transmission electron microscope (TEM). With the increase of CTAB concentration, the UV peak intensity at 276 nm, the intrinsic fluorescence, the zeta potential of Hb and the system conductivity were all enhanced. Hb was easily oxidized to oxyHb and hemichrome. In Hb/acyclovir/CTAB system,CTAB made the UV-Vis spectrum, fluorescence, conductivity and conformation of Hb tend to be returned to those of the original Hb but the zeta potential not to do so. The UV absorption peak of Hb-acyclovir complex disappeared,and the tight structure of Hb aroused by acyclovir was refolded. When CTAB concentration was higher than 5 ×10-5 mol/L, the two absorption peaks at 536 and 576 nm appeared again, and the Hb structure became looser again.

  13. Room temperature X- and gamma-ray detectors using thallium bromide crystals

    CERN Document Server

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

    1999-01-01

    Thallium bromide (TlBr) is a compound semiconductor with wide band gap (2.68 eV) and high X- and gamma-ray stopping power. The TlBr crystals were grown by the horizontal travelling molten zone (TMZ) method using purified material. Two types of room temperature X- and gamma-ray detectors were fabricated from the TlBr crystals: TlBr detectors with high detection efficiency for positron annihilation gamma-ray (511 keV) detection and TlBr detectors with high-energy resolution for low-energy X-ray detection. The detector of the former type demonstrated energy resolution of 56 keV FWHM (11%) for 511 keV gamma-rays. Energy resolution of 1.81 keV FWHM for 5.9 keV was obtained from the detector of the latter type. In order to analyze noise characteristics of the detector-preamplifier assembly, the equivalent noise charge (ENC) was measured as a function of the amplifier shaping time for the high-resolution detector. This analysis shows that parallel white noise and 1/f noise were dominant noise sources in the detector...

  14. Effects of Cholinergic Stimulation with Pyridostigmine Bromide on Chronic Chagasic Cardiomyopathic Mice

    Directory of Open Access Journals (Sweden)

    Marília Beatriz de Cuba

    2014-01-01

    Full Text Available The aim of the present study was to assess the effects of an anticholinesterase agent, pyridostigmine bromide (Pyrido, on experimental chronic Chagas heart disease in mice. To this end, male C57BL/6J mice noninfected (control:Con or chronically infected (5 months with Trypanosoma cruzi (chagasic:Chg were treated or not (NT with Pyrido for one month. At the end of this period, electrocardiogram (ECG; cardiac autonomic function; heart histopathology; serum cytokines; and the presence of blood and tissue parasites by means of immunohistochemistry and PCR were assessed. In NT-Chg mice, significant changes in the electrocardiographic, autonomic, and cardiac histopathological profiles were observed confirming a chronic inflammatory response. Treatment with Pyrido in Chagasic mice caused a significant reduction of myocardial inflammatory infiltration, fibrosis, and hypertrophy, which was accompanied by a decrease in serum levels of IFNγ with no change in IL-10 levels, suggesting a shift of immune response toward an anti-inflammatory profile. Lower nondifferent numbers of parasite DNA copies were observed in both treated and nontreated chagasic mice. In conclusion, our findings confirm the marked neuroimmunomodulatory role played by the parasympathetic autonomic nervous system in the evolution of the inflammatory-immune response to T. cruzi during experimental chronic Chagas heart disease in mice.

  15. The DNA intercalators ethidium bromide and propidium iodide also bind to core histones

    Directory of Open Access Journals (Sweden)

    Amrita Banerjee

    2014-01-01

    Full Text Available Eukaryotic DNA is compacted in the form of chromatin, in a complex with histones and other non-histone proteins. The intimate association of DNA and histones in chromatin raises the possibility that DNA-interactive small molecules may bind to chromatin-associated proteins such as histones. Employing biophysical and biochemical techniques we have characterized the interaction of a classical intercalator, ethidium bromide (EB and its structural analogue propidium iodide (PI with hierarchical genomic components: long chromatin, chromatosome, core octamer and chromosomal DNA. Our studies show that EB and PI affect both chromatin structure and function, inducing chromatin compaction and disruption of the integrity of the chromatosome. Calorimetric studies and fluorescence measurements of the ligands demonstrated and characterized the association of these ligands with core histones and the intact octamer in absence of DNA. The ligands affect acetylation of histone H3 at lysine 9 and acetylation of histone H4 at lysine 5 and lysine 8 ex vivo. PI alters the post-translational modifications to a greater extent than EB. This is the first report showing the dual binding (chromosomal DNA and core histones property of a classical intercalator, EB, and its longer analogue, PI, in the context of chromatin.

  16. Synthesis of zeolitic materials from volcanic ash in presence and absence of cetyltrimethylammonium bromide

    International Nuclear Information System (INIS)

    Zeolitic materials as Na-phillipsite, Na-K-phillipsite-like zeolites and the mixtures of zeolites (phillipsite+analcime and phillipsite+chabazite+analcime) were synthesized from volcanic ash, either in presence and absence of cetiltrimetilamonium bromide (CTAB). The ash sample used in the laboratory experiments contains 75.36% SiO2 and 14.11% Al2O3, abundances. The reaction time as well as the influence of CTAB were studied in the zeolitic materials crystallization. The experiments were carried out under hydrothermal conditions, autogenic pressure and temperature of 150 grades C, as well as reaction time from 8 to 116 h. Products from this hydrothermal treatment were identified by X-ray diffraction (XRD) and characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy (Sem-EDS). Of the zeolitic materials obtained the Na-K-phillipsite-like zeolite was found to be the most effective for the retention of cations Pb2+, Zn2+ and Ba2+. (Author)

  17. Shape-directing role of cetyltrimethylammonium bromide on the morphology of extracellular synthesis of silver nanoparticles

    Directory of Open Access Journals (Sweden)

    Shaeel Ahmed Al-Thabaiti

    2015-07-01

    Full Text Available Oriental plane leaf extracts were used as a reducing-, stabilizing- and capping-agent for the preparation of silver nanoparticles (AgNPs for the first time. The size, shape, size distribution and optical properties strongly depend on the experimental conditions, absence, and presence of shape-directing cetyltrimethylammonium bromide (CTAB. UV–vis spectroscopy, transmission electron microscopy and selected electron diffraction ring patterns were used to determine the morphology of resulting AgNPs at different time intervals. The spectra showed a surface Plasmon resonance (SPR peak at 450 nm which is the characteristic of spherical AgNPs (diameter ranging from 10 to 30 nm. The peak shifted to shorter wavelength (blue shift from 450 to 425 nm and sharpness of the peak also decreases in the presence of CTAB which might be due to the capping action of CTAB. A layer of ca. 3 nm around a group of the AgNPs in which the inner layer is bound to the AgNPs surface via the active groups of the extract has been observed.

  18. Interactions of cellulose-based comb polyelectrolyte with oppositely charged surfactant dodecyl-trimethylammonium bromide.

    Science.gov (United States)

    Pan, Hong; Chen, Pei-Yao; Liu, Hai-Xue; Chen, Yu; Wei, Yu-Ping; Zhang, Ming-Jie; Cheng, Fa

    2012-07-01

    A comb ethyl cellulose-g-sodium polyacrylate (EC-g-SPA) was synthesized by atom transfer radical polymerization. The amphiphilic properties of the EC-g-SPA were determined by surface tension measurements. The interactions between EC-g-SPA and the cationic surfactant dodecyl-trimethylammonium bromide (C12TAB) were investigated by surface tension, turbidity, dynamic light scattering and transmission electron microscopy (TEM). The results revealed that the critical aggregate concentration (CAC) of the complexes was 0.8mM. When the C12TAB concentration was lower than the CAC, the hydrodynamic diameter (Dh) of the complexes decreased as the surfactant concentration was increased. As the C12TAB concentration was increased above the CAC, the Dh initially increased slightly, followed by a sharp decrease. The changes in the sizes and shapes of the aggregates were studied by TEM. The interactions between two species and the structure of the EC-g-SPA/C12TAB complexes were also discussed. PMID:24750878

  19. Computational study of dissociative electron attachment to π-allyl ruthenium (II) tricarbonyl bromide

    Science.gov (United States)

    Thorman, Rachel M.; Bjornsson, Ragnar; Ingólfsson, Oddur

    2016-08-01

    Motivated by the current interest in low energy electron induced fragmentation of organometallic complexes in focused electron beam induced deposition (FEBID) we have evaluated different theoretical protocols for the calculation of thermochemical threshold energies for DEA to the organometallic complex π-allyl ruthenium (II) tricarbonyl bromide. Several different computational methods including density functional theory (DFT), hybrid-DFT and coupled cluster were evaluated for their ability to predict these threshold energies and compared with the respective experimental values. Density functional theory and hybrid DFT methods were surprisingly found to have poor reliability in the modelling of several DEA reactions; however, the coupled cluster method LPNO-pCCSD/2a was found to produce much more accurate results. Using the local correlation pair natural orbital (LPNO) methodology, high level coupled cluster calculations for open-shell systems of this size are now affordable, paving the way for reliable theoretical DEA predictions of such compounds. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  20. Water-lithium bromide double-effect absorption cooling analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

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

    1980-12-01

    This investigation involved the development of a numerical model for the transient simulation of the double-effect, water-lithium bromide absorption cooling machine, and the use of the model to determine the effect of the various design and input variables on the absorption unit performance. The performance parameters considered were coefficient of performance and cooling capacity. The sensitivity analysis was performed by selecting a nominal condition and determining performance sensitivity for each variable with others held constant. The variables considered in the study include source hot water, cooling water, and chilled water temperatures; source hot water, cooling water, and chilled water flow rates; solution circulation rate; heat exchanger areas; pressure drop between evaporator and absorber; solution pump characteristics; and refrigerant flow control methods. The performance sensitivity study indicated in particular that the distribution of heat exchanger area among the various (seven) heat exchange components is a very important design consideration. Moreover, it indicated that the method of flow control of the first effect refrigerant vapor through the second effect is a critical design feature when absorption units operate over a significant range of cooling capacity. The model was used to predict the performance of the Trane absorption unit with fairly good accuracy. The dynamic model should be valuable as a design tool for developing new absorption machines or modifying current machines to make them optimal based on current and future energy costs.

  1. Denaturation and intermediates study of two sturgeon hemoglobins by n-dodecyl trimethylammonium bromide

    Science.gov (United States)

    Ariaeenejad, Shohreh; Habibi-Rezaei, Mehran; Kavousi, Kaveh; Jamili, Shahla; Fatemi, Mohammad Reza; Hong, Jun; Poursasan, Najmeh; Sheibani, Nader; Moosavi-Movahedi, Ali. A.

    2013-01-01

    Varieties of hemoglobin (Hb) forms exist in fish, which are usually well adapted to the different ecological conditions or various habitats. In the current study, Hbs from two Sturgeon species of the Southern Caspian Sea Basin were purified and studied upon interaction with n-dodecyl trimethylammonium bromide (DTAB; as a cationic surfactant) by various methods including UV-visible absorption, dynamic light scattering (DLS), and ANS fluorescence spectrophotometry. The chemometric analysis of Hbs was investigated upon interaction with DTAB under titration, using UV-visible absorption spectra. The chemometric resolution techniques were used to determine the number of the components and mole fraction of the oxidized Hbs. These results provided the evidence for the existence of three different molecular components including native (N), intermediate (I) and denatured (D) in sturgeon Hbs. According to the distribution of intermediates, which were broadened in a range of DTAB concentration, the aggregation states, DLS experiments, and thermal stability (Tm obtained by differential scanning calorimetry (DSC)), the Acipenser stellatus Hb was more stable compared to Acipenser persicus Hb. These results demonstrate a significant relationship between the stability of fish Hbs and the habitat depth requirements. PMID:23142155

  2. The sorption behavior of DDT onto sediment in the presence of surfactant cetyltrimethylammonium bromide

    International Nuclear Information System (INIS)

    Highlights: → The sorption behavior of a complex system consists of DDT and CTAB onto marine sediment was studied. → Batch experiments were carried out to investigate the kinetics and thermodynamics. → The presence of CTAB could remarkably accelerate and enhance the sorption of DDT. → The sorption of DDT had relatively more negative ΔG0 and ΔH0 in the presence of CTAB. - Abstract: The sorption behavior of p,p'- and o,p'-dichlorodiphenyltrichloroethane (DDT) in the presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB) on sediment was studied. Batch experiments were carried out to investigate the kinetics and thermodynamics of the process. The kinetic behavior of these three chemicals on sediment was described by pseudo-second-order kinetic equations, and the isotherms followed the Freundlich model well. The presence of CTAB was able to remarkably accelerate and enhance the sorption of DDT, whereas DDT showed no effect on the sorption of CTAB in our considered concentration ranges. The thermodynamic parameters, such as standard enthalpy change (ΔH0), standard entropy change (ΔS0) and standard Gibbs free energy change (ΔG0) showed that the sorption process of p,p'- and o,p'-DDT was physical, spontaneous and exothermic, and the randomness at the solid-liquid interface increased during the process. In the presence of CTAB, the sorption of DDT showed significantly negative ΔG0 and ΔH0 values.

  3. Electrodeposition of Nanocrystalline Chromium Coatings Based on 1-Butyl-3-Methylimidazolium-Bromide Ionic Liquid.

    Science.gov (United States)

    He, Xinkuai; Zhu, Qingyun; Hou, Bailong; Cai, Youxing; Li, Chen; Fu, Liqin; Wu, Luye

    2015-12-01

    The electrochemical behavior of trivalent chromium reduction from 1-butyl-3-methylimidazolium-bromide ([BMIM]Br) ionic liquid is studied. The result of cyclic voltammetry shows that the Cr(III) reduction is irreversible and occurs in two steps, Cr(III)to Cr(II), and Cr(II) to Cr(0), respectively. In the electrochemical impedance spectroscopy measurements, the preferable equivalent circuit is made to fit the experimental data. The effects of electroplating parameters on coating thickness and electrodepositon rate are investigated by potentiostatic method on Cu electrode from Cr(III)-[BMIM]Br solution. The results show that the temperature and depositing potential have great effect on the coating thickness and electrodeposition rate. The surface morphology and composition of deposited Cr are investigated using scanning electron microscope (SEM) and energy-dispersive spectroscopy (EDS). SEM analysis shows that chromium electrodeposits obtained on Cu electrodes present a ball-like structure. EDS analysis shows that the coatings are composed of Cr. Moreover, the corrosion resistance of the as-deposited chromium layer is evaluated using polarization curves. The results show that the corrosion resistance of the chromium coatings obtained at higher potential is better. PMID:26682363

  4. Binding of dyes to hydroxyapatite treated with cetylpyridinium chloride or cetrimonium bromide.

    Science.gov (United States)

    Jensen, J E

    1978-03-01

    The effect of cetylpyridinium chloride (CPC) and cetrimonium bromide (CTAB) on the adsorption of some acidic food dyes to hydroxyapatite was studied. The dyes investigated were brilliant blue (FD&C Blue No. 1), tartrazine (FD&C Yellow No. 5), sunset yellow (FD&C Yellow No. 6) and amaranth (FD&C Red No. 2). The apatite had adsorbed 9.2 mumol CPC per g dry weight. The adsorbed CPC was in equilibrium with a free concentration of 20 microgram/ml (58 micrometer). The adsorption of CPC and CTAB to the apatite was followed by an increased ability of the crystals to bind the dyes. The dyes were very firmly adsorbed and were not released during a series of washings. Untreated apatite showed only a minor affinity for the dyes. The adsorbed dyes were easily washed out. CPC and CTAB showed the smae specific ability to increase the binding capacity of the apatite. The results are discussed and related to the formation of stains on the teeth in persons using quaternary ammonium compounds for mouthrinsing. A mechanism explaining the production of stains is proposed.

  5. Dehalogenative Homocoupling of Terminal Alkynyl Bromides on Au(111): Incorporation of Acetylenic Scaffolding into Surface Nanostructures.

    Science.gov (United States)

    Sun, Qiang; Cai, Liangliang; Ma, Honghong; Yuan, Chunxue; Xu, Wei

    2016-07-26

    On-surface C-C coupling reactions of molecular precursors with alkynyl functional groups demonstrate great potential for the controllable fabrication of low-dimensional carbon nanostructures/nanomaterials, such as carbyne, graphyne, and graphdiyne, which demand the incorporation of highly active sp-hybridized carbons. Recently, through a dehydrogenative homocoupling reaction of alkynes, the possibility was presented to fabricate surface nanostructures involving acetylenic linkages, while problems lie in the fact that different byproducts are inevitably formed when triggering the reactions at elevated temperatures. In this work, by delicately designing the molecular precursors with terminal alkynyl bromide, we introduce the dehalogenative homocoupling reactions on the surface. As a result, we successfully achieve the formation of dimer structures, one-dimensional molecular wires and two-dimensional molecular networks with acetylenic scaffoldings on an inert Au(111) surface, where the unexpected C-Au-C organometallic intermediates are also observed. This study further supplements the database of on-surface dehalogenative C-C coupling reactions, and more importantly, it provides us an alternative efficient way for incorporating the acetylenic scaffolding into low-dimensional surface nanostructures. PMID:27326451

  6. Spectroscopic study of tetradecyltrimethylammonium bromide Pt-C14TAB nanoparticles: Structure and Stability

    Energy Technology Data Exchange (ETDEWEB)

    Borodko, Y.; Jones, L.; Frei, H.; Somorjai, G.

    2009-01-09

    The vibrational spectra of platinum nanoparticles (12 nm) capped with tetradecyltrimethylammonium bromide, C{sub 14}TAB, were investigated by Fourier transform infrared (FTIR) spectroscopy. We have shown that the thermal decay of Pt-C{sub 14}TAB nanoparticles in N{sub 2}, H{sub 2} and O{sub 2} atmospheres leads to the release of hydrocarbon chain of surfactant and the formation of strongly bonded layer of ammonium cations on the platinum surface. The platinum atoms accessible to CO chemisorptions were not reducible by hydrogen in the temperature ranging from 30 C to 200 C. A FTIR spectrum of C{sub 14}TAB adsorbed on Pt nanoparticles dramatically perturbed as compared with pure C{sub 14}TAB. New intense and broad bands centered at 1450 cm{sup -1} and 760 cm{sup -1} are making their appearance in Pt-C{sub 14}TAB. It may be speculated, that new bands are result of coupling between conducting electrons of Pt and molecular vibrations of adsorbed C{sub 14}TAB and as a consequence specific vibrational modes of ammonium cation transformed into electron-vibrational modes.

  7. Methyl chloride and methyl bromide emissions from baking: an unrecognized anthropogenic source.

    Science.gov (United States)

    Thornton, Brett F; Horst, Axel; Carrizo, Daniel; Holmstrand, Henry

    2016-05-01

    Methyl chloride and methyl bromide (CH3Cl and CH3Br) are the largest natural sources of chlorine and bromine, respectively, to the stratosphere, where they contribute to ozone depletion. We report the anthropogenic production of CH3Cl and CH3Br during breadbaking, and suggest this production is an abiotic process involving the methyl ester functional groups in pectin and lignin structural polymers of plant cells. Wide variations in baking styles allow only rough estimates of this flux of methyl halides on a global basis. A simple model suggests that CH3Br emissions from breadbaking likely peaked circa 1990 at approximately 200tonnes per year (about 0.3% of industrial production), prior to restrictions on the dough conditioner potassium bromate. In contrast, CH3Cl emissions from breadbaking may be of similar magnitude as acknowledged present-day CH3Cl industrial emissions. Because the mechanisms involve functional groups and compounds widely found in plant materials, this type of methyl halide production may occur in other cooking techniques as well. PMID:26878644

  8. Swelling behaviour of amphiphilic poly (methacryloxyethl dimethylalkane ammonium bromide) gels in alcohol/water solvent systems

    International Nuclear Information System (INIS)

    Three kinds of amphiphilic PMADAB gels were prepared through radiation-induced polymerization and crosslinking of methacryloxyethyl dimethylalkane ammonium bromide (MADAB) with different alkyl side chains (butyl, octyl and dodecyl). The length of alkyl side chains had significant influence on swelling behavior of the PMADAB gels in alcohol/water solvent. Equilibrium swelling degree (EDS) of PMBDAB (butyl) gel in water was ca. 160 and decreased with increasing alcohol content (x), whereas EDS of PMODAB (octyl) and PMDDDAB (dodecyl) gels showed a convex-upward function of x, i.e., these two gels barely swelled in pure water and swelled with increasing x and then shrank gradually. This phenomenon was explained by the hydrophobic association of long alkyl chains and a cosolvency effect of PMADAB in alcohol and water. The swelling behavior of PMADAB gels in methanol, ethanol and isopropanol were similar, and their EDS are related with the dielectric constant of alcohol solvents. The results suggest that PMADAB gels may be potential absorbents for various kinds of alcohols. (authors)

  9. Application of cetyltrimethylammonium bromide bentonite-titanium dioxide photocatalysis technology for pretreatment of aging leachate.

    Science.gov (United States)

    Cai, Fei-Fei; Yang, Zhao-Hui; Huang, Jing; Zeng, Guang-Ming; Wang, Li-Ke; Yang, Jian

    2014-06-30

    Organobentonite-photocatalysis technology was applied to pretreat aging leachate containing refractory pollutants. The organobentonite was synthesized by organic modifier cetyltrimethylammonium bromide (CTMAB) and natural bentonite. In characterization experiments, we could confirm that organic functional groups of cetyltrimethylammonium (CTMA(+)) cations were successfully loaded on the surface of bentonite. The combination of CTMAB2.5 adsorption and TiO2 photocatalysis was superior to either running separately. Furthermore, removal efficiency of simultaneously utilizing CTMAB2.5 and TiO2 was better than them in succession. The combination technology was feasible and was optimized by response surface methodology (RSM) with COD and NH3-N removal rate as the target responses. The optimal operation conditions calculated from the regression equations were CTMAB2.5 dosage of 7.5 g/L, pH at 3.5, TiO2 dosage of 1.63 g/L, and reaction time for 60.02 min, which maintained the removal of COD and NH3-N at 82% and 37%, respectively.

  10. Irradiation as an alternative treatment to methyl bromide for insect control

    International Nuclear Information System (INIS)

    Methyl Bromide (MB) is widely used as a fumigant for the control of pests of stored grain, legumes, oil seeds, dry fruits and nuts, pest of timber, soil insects, soil nematodes, soil pathogens of plants, and as a quarantine treatment against pest of fresh horticultural products, and pests and diseases in propagation material. The global phase-out of MBB in advanced countries by 2005 and in developing countries by 2015 under the Montreal Protocol, because of its ozone depleting property, has prompted increasing interest in the use of irradiation as an alternative to MB for insect control in food and agricultural commodities in recent years. Irradiation at fairly low doses, of the order of 1 kGy or less is an effective alternative to chemical treatment of foods. The advantages of radiation processing include short treatment time in comparison to several days of exposure required in chemical fumigation, no undesirable chemical residues in the food, no resistance developed by the insects and no significant changes in the organoleptic, physicochemical and functional properties or the nutritive value of the treated products. Turkey is the leading country in the world, in production and exports of dried fig, apricot,raisin and hazelnut. One of the main problem in the export trade is infestation by stored product insects. In Turkey, the new legal regulations on food irradiation were published in Official Newspaper on November 6, 1999. (3 tables and 10 refs. included)

  11. Interferences in automated phenol red method for determination of bromide in water

    Science.gov (United States)

    Basel, C.L.; Defreese, J.D.; Whittemore, D.O.

    1982-01-01

    The phenol red method for the determination of bromide in water has been automated by segmented flow analysis. Samples can be analyzed at a rate of 20 samples/h with a method detection limit, defined, as the concentration giving a signal about three times the standard deviation of replicate anaiyte determinations in reagent water, of 10 ??g/L. Samples studied include oil-field brines, halite solution brines, ground-waters contaminated with these brines, and fresh groundwaters. Chloride and bicarbonate cause significant positive interferences at levels as low as 100 mg/L and 50 mg/L, respectively. Ammonia gives a negative interference that is important at levels as low as 0.05 mg/L. An ionic strength buffer is used to suppress a positive ionic strength interference, correction curves are used to compensate for the chloride interference, the bicarbonate interference is minimized by acidification, and the ammonia interference is eliminated by its removal by ion exchange. Reaction product studies are used to suggest a plausible mode of chloride interference. ?? 1982 American Chemical Society.

  12. Dual bronchodilator therapy with aclidinium bromide/formoterol fumarate for chronic obstructive pulmonary disease.

    Science.gov (United States)

    D'Urzo, Tony; Donohue, James F; Price, David; Miravitlles, Marc; Kerwin, Edward

    2015-10-01

    Inhaled bronchodilator therapy is a mainstay of treatment for chronic obstructive pulmonary disease (COPD). Despite the number and types of treatments available, the control of symptoms and exacerbations remains suboptimal, and adherence to, and persistence with, inhaled therapy is generally poor. Results from clinical studies suggest that dual bronchodilator therapy with long-acting muscarinic receptor antagonists (LAMAs) and long-acting β2 adrenergic receptor agonists (LABAs) may provide additional benefit over LAMA or LABA monotherapy without additive effects on safety and tolerability. Several combinations of a LAMA plus a LABA have recently become available in a single inhaler for maintenance therapy for adults with moderate-to-severe COPD, including aclidinium bromide/formoterol fumarate, glycopyrronium/indacaterol and umeclidinium/vilanterol. Here, we review clinical data demonstrating significant improvements in bronchodilation, 24-h symptoms, and health status with aclidinium/formoterol twice daily, and discuss how this treatment can be implemented in clinical practice as part of a patient-focused approach to disease control. PMID:26366803

  13. Prolonged use of pancuronium bromide and sensorineural hearing loss in childhood survivors of congenital diaphragmatic hernia.

    Science.gov (United States)

    Cheung, P Y; Tyebkhan, J M; Peliowski, A; Ainsworth, W; Robertson, C M

    1999-08-01

    Sensorineural hearing loss (SNHL) is a significant neurologic morbidity in survivors of neonatal congenital diaphragmatic hernia (CDH), with a reported incidence of up to 60%. In a historical cohort study of 37 neonates with CDH, we investigated the use of pancuronium bromide (PB) and common ototoxic drugs during the neonatal period and their relationship to SNHL in childhood survivors. Survivors with SNHL (n = 23) had significantly higher cumulative dose of PB administered during the neonatal illness than survivors without SNHL (n = 14). The cumulative dose and duration of PB use significantly correlated (r = 0.66-0.81) and independently predicted (adjusted r (2) = 0.42-0.64) the greatest intensity (in decibels) and the widest band (lowest frequency in hertz) loss of SNHL. No differences were identified between survivors with and without SNHL regarding demographic and neonatal characteristics (including oxygenation and ventilation variables and the cumulative dose and duration of therapy with aminoglycosides, vancomycin, and furosemide), although survivors with SNHL had received a modestly higher cumulative dose of ethacrynic acid than survivors without SNHL. Although we show that prolonged administration of PB during the neonatal period is associated with SNHL in childhood survivors of CDH, further multicenter studies are required to investigate the possible etiologies of SNHL in this high-risk population.

  14. Evaluation of methyl bromide alternatives efficacy against soil-borne pathogens, nematodes and soil microbial community.

    Directory of Open Access Journals (Sweden)

    Hongwei Xie

    Full Text Available Methyl bromide (MB and other alternatives were evaluated for suppression of Fusarium spp., Phytophthora spp., and Meloidogyne spp. and their influence on soil microbial communities. Both Fusarium spp. and Phytophthora spp. were significantly reduced by the MB (30.74 mg kg-1, methyl iodide (MI: 45.58 mg kg-1, metham sodium (MS: 53.92 mg kg-1 treatments. MS exhibited comparable effectiveness to MB in controlling Meloidogyne spp. and total nematodes, followed by MI at the tested rate. By contrast, sulfuryl fluoride (SF: 33.04 mg kg-1 and chloroform (CF: 23.68 mg kg-1 showed low efficacy in controlling Fusarium spp., Phytophthora spp., and Meloidogyne spp. MB, MI and MS significantly lowered the abundance of different microbial populations and microbial biomass in soil, whereas SF and CF had limited influence on them compared with the control. Diversity indices in Biolog studies decreased in response to fumigation, but no significant difference was found among treatments in PLFA studies. Principal component and cluster analyses of Biolog and PLFA data sets revealed that MB and MI treatments greatly influenced the soil microbial community functional and structural diversity compared with SF treatment. These results suggest that fumigants with high effectiveness in suppressing soil-borne disease could significantly influence soil microbial community.

  15. Corrosion rate of copper in aqueous lithium bromide concentrated solutions at room temperature by immersion tests

    Energy Technology Data Exchange (ETDEWEB)

    Munoz-Portero, M.J.; Garcia-Anton, J.; Guinon-Segura, J.L.; Perez-Herranz, V. [Departamento de Ingenieria Quimica y Nuclear, E.T.S.I. Industriales, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia (Spain)

    2004-07-01

    Concentrated solutions of lithium bromide (LiBr) are widely used in absorption refrigeration and heating systems. However, LiBr solutions can cause serious corrosion problems in structural materials (copper, steels, and other metals) in an absorption plant. The aim of the present work was the study of the corrosion rate of copper in 400 and 700 g/L (4.61 and 8.06 M) LiBr solutions pre-nitrogenous or pre-oxygenated at room temperature by immersion tests. The corroded copper concentration was determined with two techniques: weight-loss method and polarographic method. The corrosion curves of copper in LiBr solutions at room temperature as a function of the exposure time showed a similar tendency, and were fitted to a power function such as: C = kt{sup b}, where C was the corroded copper quantity per unit area (mg/cm{sup 2}), t was the exposure time (h), k was the corrosion coefficient, and b was the time exponent. From the corrosion coefficient values (k) it was deduced that the corrosion rate of copper in LiBr solutions at room temperature followed the order: 400 g/L (bubble of O{sub 2}) > 400 g/L (bubble of N{sub 2}) > 700 g/L (bubble of O{sub 2}) > 700 g/L (bubble of N{sub 2}). (authors)

  16. Synthesis of zeolitic materials from volcanic ash in presence and absence of cetyltrimethylammonium bromide

    Energy Technology Data Exchange (ETDEWEB)

    Sanhueza N, V. M.; Bennun T, L. D., E-mail: vsanhuez@udec.cl [Universidad de Concepcion, Facultad de Ciencias Quimicas, Edmundo Larenas 129, Region del Biobio (Chile)

    2015-07-01

    Zeolitic materials as Na-phillipsite, Na-K-phillipsite-like zeolites and the mixtures of zeolites (phillipsite+analcime and phillipsite+chabazite+analcime) were synthesized from volcanic ash, either in presence and absence of cetiltrimetilamonium bromide (CTAB). The ash sample used in the laboratory experiments contains 75.36% SiO{sub 2} and 14.11% Al{sub 2}O{sub 3}, abundances. The reaction time as well as the influence of CTAB were studied in the zeolitic materials crystallization. The experiments were carried out under hydrothermal conditions, autogenic pressure and temperature of 150 grades C, as well as reaction time from 8 to 116 h. Products from this hydrothermal treatment were identified by X-ray diffraction (XRD) and characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy (Sem-EDS). Of the zeolitic materials obtained the Na-K-phillipsite-like zeolite was found to be the most effective for the retention of cations Pb{sup 2+}, Zn{sup 2+} and Ba{sup 2+}. (Author)

  17. Effectiveness of pinaverium bromide in the treatment of primitive biliary dyskinesia: 99mTc-P-IDA scintigraphic evaluation.

    Science.gov (United States)

    Scaffidi, A; Costa, R; Frontespezi, S

    1987-09-01

    The 99mTc-P-IDA (technetium-p-iminodiacetic acid) hepatocholangiocholecystoscintigraphy is a diagnostic technique which allows information on the liver biligenetic and excretory capabilities to be obtained. It is, moreover, a test that mirrors closely the anatomic and functional conditions of the cholecyst and choledochus. In this study the authors wanted to verify whether pinaverium bromide, a drug with a documented musculotropic-spasmolytic activity, was able to induce changes in some abnormal instrumental parameters observed in 24 subjects with primitive biliary dyskinesia. The results revealed that the ti values, characteristically longer in those subjects, were significantly reduced in the group of patients treated with pinaverium bromide. On the contrary, in the group of patients treated with placebo, there was no change with respect to this parameter. PMID:3316061

  18. Vapor-liquid equilibria of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems

    Energy Technology Data Exchange (ETDEWEB)

    Mun, S.Y.; Lee, H.

    1999-12-01

    Vapor-liquid equilibrium data of the water + 1,3-propanediol and water + 1,3-propanediol + lithium bromide systems were measured at 60, 160, 300, and 760 mmHg at temperatures ranging from 315 to 488 K. The apparatus used in this work is a modified still especially designed for the measurement of low-pressure VLE, in which both liquid and vapor are continuously recirculated. For the analysis of salt-containing solutions, a method incorporating refractometry and gravimetry was used. From the experimental measurements, the effect of lithium bromide on the VLE behavior of water + 1,3-propanediol was investigated. The experimental data of the salt-free system were successfully correlated using the Wilson, NRTL, and UNIQUAC models. In addition, the extended UNIQUAC model of Sander et al. was applied to the VLE calculation of salt-containing mixtures.

  19. Palladium-Catalyzed α-Arylation of Aryl Acetic Acid Derivatives via Dienolate Intermediates with Aryl Chlorides and Bromides

    OpenAIRE

    Sha, Sheng-Chun; Zhang, Jiadi; Walsh, Patrick J.

    2015-01-01

    To date, examples of α-arylation of carboxylic acids remain scarce. Using a deprotonative cross-coupling process (DCCP), a method for palladium-catalyzed γ-arylation of aryl acetic acids with aryl halides has been developed. This protocol is applicable to a wide range of aryl bromides and chlorides. A procedure for the palladium-catalyzed α-arylation of styryl acetic acids is also described.

  20. Efficacy of Tiotropium Bromide and Rehabilitation Treatment on Pulmonary Function of Patients With Sulfur Mustard Lung Injury

    OpenAIRE

    2015-01-01

    Background: Chronic pulmonary complication is the most common delayed toxic effect of sulfur mustard (SM) and it has no treatment so far. Objectives: To evaluate short-term therapeutic effects of inhaled tiotropium bromide and pulmonary rehabilitation on pulmonary function of patients with SM induced lung injury. Patients and Methods: In a randomized clinical trial, using convenient sampling method, 54 patients with chronic lung disease due to SM exposure were recruited in Baqiyatallah Genera...

  1. Impurity aggregation during radiation-stimulated decomposition of trimetaphosphate molecular centre in potassium bromide monocrystals. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Vasil' ev, I.A.; Mel' nikova, I.N.; Shibaev, V.A. (Leningradskij Tekhnologicheskij Inst. (USSR))

    1984-05-01

    On the basis of results of radiochemical and IR-spectrophotometric analyses, regularities of ..gamma..-radiolysis of trimetaphosphate molecular centre in potassium bromide matrix are found. Reactions most completely reflecting changes in the system under the effect of ionizing radiation are suggested. Computer-aided design has permitted to choose optimum values of rate constants for chemical reactions. Radiation-stimulated diffusion coefficient is estimated.

  2. Palladium-Catalyzed Heck Coupling Reaction of Aryl Bromides in Aqueous Media Using Tetrahydropyrimidinium Salts as Carbene Ligands

    Directory of Open Access Journals (Sweden)

    İsmail Özdemir

    2010-01-01

    Full Text Available An efficient and stereoselective catalytic system for the Heck cross coupling reaction using novel 1,3-dialkyl-3,4,5,6-tetrahydropyrimidinium salts (1, LHX and Pd(OAc2 loading has been reported. The palladium complexes derived from the salts 1a-f prepared in situ exhibit good catalytic activity in the Heck coupling reaction of aryl bromides under mild conditions.

  3. Effects of Soil and Water Content on Methyl Bromide Oxidation by the Ammonia-Oxidizing Bacterium Nitrosomonas europaea†

    OpenAIRE

    Duddleston, Khrystyne N.; Bottomley, Peter J; Porter, Angela; Arp, Daniel J.

    2000-01-01

    Little information exists on the potential of NH3-oxidizing bacteria to cooxidize halogenated hydrocarbons in soil. A study was conducted to examine the cooxidation of methyl bromide (MeBr) by an NH3-oxidizing bacterium, Nitrosomonas europaea, under soil conditions. Soil and its water content modified the availability of NH4+ and MeBr and influenced the relative rates of substrate (NH3) and cosubstrate (MeBr) oxidations. These observations highlight the complexity associated with characterizi...

  4. Delivery of albuterol and ipratropium bromide from two nebulizer systems in chronic stable asthma. Efficacy and pulmonary deposition

    International Nuclear Information System (INIS)

    Bronchodilator responses to both nebulized albuterol (salbutamol) and ipratropium bromide and aerosol delivery to the tracheobronchial tree have been assessed in eight patients with chronic stable asthma (mean baseline FEV1, 50 percent; reversibility greater than 20 percent). Two commercially available nebulizer systems were used, namely, a Turret nebulizer operated at a compressed gas flow rate of 12 L/min (droplet MMD, 3.3 mu) and an Inspiron nebulizer driven at 6 L/min (MMD, 7.7 mu). Albuterol was given as doses of 250 micrograms, 250 micrograms, 500 micrograms, and 1,000 micrograms (cumulative dose, 2 mg) and ipratropium bromide as doses of 50 micrograms, 50 micrograms, 100 micrograms, and 200 micrograms (cumulative dose, 400 micrograms) at intervals of 35 minutes. For albuterol, bronchodilatation was significantly (p less than 0.05) greater at all dosage levels with the Turret. For ipratropium, bronchodilatation was similar for both nebulizers. Measurements of aerosol deposition using 99mTc-labelled pentetic acid (diethylenetriamine pentaacetic acid; DTPA) showed that 9.1 +/- 1.1 percent and 2.7 +/- 0.2 percent of the dose reached the lungs during nebulization to dryness for Turret and Inspiron, respectively (p less than 0.01); distribution within the lungs was similar for the two aerosols. Selection of nebulizer apparatus can influence delivery of aerosol and subsequent bronchodilator response to albuterol in patients with chronic stable asthma but is less important for aerosol delivery of ipratropium bromide in these patients

  5. Dual-permeability modeling of preferential bromide leaching from a tile-drained glacial till agricultural field

    Science.gov (United States)

    Gerke, Horst H.; Maximilian Köhne, J.

    2004-04-01

    A tile-drained agricultural field can be regarded as a 'field-scale' lysimeter that may be used to study soil water and chemical transport under relatively natural conditions. Tile discharge and effluent bromide concentrations measured in a previous field tracer experiment for a structured clayey loam at Bokhorst, Northern Germany, indicated strong preferential flow. Simulation using single domain HYDRUS numerical flow and transport model could nevertheless explain water outflow, however, completely failed to describe tile-drain leaching patterns of the conservative tracer. The objective of this paper was to analyze whether the nonequilibrium-type dual-permeability model concept could better capture soil structure related principle mechanisms of preferential leaching in the unsaturated soil at that study site. The dual-permeability model (DUAL) describes for soil matrix and fracture pore systems Darcian flow with coupled Richards' equations and convective-dispersive (CD) solute transport with coupled CD equations. The hydraulic parameters of the dual-permeability model were obtained from standard soil hydraulic measurements by adopting a bimodal fitting procedure, whereas transport parameters were inferred from soil column tracer experiments and geometrical transfer term parameters were derived using qualitative soil structure descriptions. The hydraulic conductivity Ka in the inter-domain water transfer term and the effective diffusion coefficient Da in the solute mass transfer term were calibrated by comparing simulated with measured tile flow and effluent concentrations. The DUAL approach described water flow similarly well as the single-domain model. Bromide concentrations in the tile effluent could be approximated with DUAL when decreasing the Ka and Da values by three orders of magnitude compared with the values of the soil matrix domain. The dual-permeability approach seems to reflect nonequilibrium transport mechanisms at this structured soil since it not

  6. The effect of ethidium bromide and chloramphenicol on mitochondrial biogenesis in primary human fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Li-Pin; Ovchinnikov, Dmitry; Wolvetang, Ernst, E-mail: e.wolvetang@uq.edu.au

    2012-05-15

    The expression of mitochondrial components is controlled by an intricate interplay between nuclear transcription factors and retrograde signaling from mitochondria. The role of mitochondrial DNA (mtDNA) and mtDNA-encoded proteins in mitochondrial biogenesis is, however, poorly understood and thus far has mainly been studied in transformed cell lines. We treated primary human fibroblasts with ethidium bromide (EtBr) or chloramphenicol for six weeks to inhibit mtDNA replication or mitochondrial protein synthesis, respectively, and investigated how the cells recovered from these insults two weeks after removal of the drugs. Although cellular growth and mitochondrial gene expression were severely impaired after both inhibitor treatments we observed marked differences in mitochondrial structure, membrane potential, glycolysis, gene expression, and redox status between fibroblasts treated with EtBr and chloramphenicol. Following removal of the drugs we further detected clear differences in expression of both mtDNA-encoded genes and nuclear transcription factors that control mitochondrial biogenesis, suggesting that the cells possess different compensatory mechanisms to recover from drug-induced mitochondrial dysfunction. Our data reveal new aspects of the interplay between mitochondrial retrograde signaling and the expression of nuclear regulators of mitochondrial biogenesis, a process with direct relevance to mitochondrial diseases and chloramphenicol toxicity in humans. -- Highlights: ► Cells respond to certain environmental toxins by increasing mitochondrial biogenesis. ► We investigated the effect of Chloramphenicol and EtBr in primary human fibroblasts. ► Inhibiting mitochondrial protein synthesis or DNA replication elicit different effects. ► We provide novel insights into the cellular responses toxins and antibiotics.

  7. Application of artificial neural network in 3D imaging with lanthanum bromide calorimeter

    Science.gov (United States)

    Gostojic, A.; Tatischeff, V.; Kiener, J.; Hamadache, C.; Karkour, N.; Linget, D.; Grave, X.; Gibelin, L.; Travers, B.; Blin, S.; Barrillon, P.

    2015-07-01

    Gamma-ray astronomy in the energy range from 0.1 up to 100 MeV holds many understudied questions connected with e.g. stellar nucleosynthesis, the active Sun, neutron stars and black holes. To access the physics behind, a significant improvement in detection sensitivity is needed compared to previous missions, e.g. CGRO and INTEGRAL. One of the promising concepts for a future gamma-ray mission is an Advanced Compton Telescope. Under the project of creating a prototype of such instrument, we study the perspectives of using a novel inorganic scintillator as a calorimeter part. Modern inorganic crystal or ceramics scintillators are constantly improving on qualities such as energy resolution and radiation hardness, and this makes them a smart choice for a new space-borne telescope. At CSNSM Orsay, we have assembled a detection module from a 5 × 5cm2 area and 1 cm thick, cerium-doped lanthanum (III) bromide (LaBr3:Ce) inorganic scintillator coupled to a 64 channel multi-anode photomultiplier. The readout of the PMT signals is carried out with the ASIC MAROC, used previously for the luminometer of the ATLAS detector (CERN). Characterization, thorough measurements with various radioactive sources, as well as, single photoelectron detection have been done. Furthermore, we made a comparison of measurements with a detailed GEANT4-based simulation which includes tracking of the optical photons. Finally, we have studied the 3D reconstruction of the first interaction point of incident gamma rays, utilizing a neural network algorithm. This spatial position resolution plays a crucial part in the future implementations and, together with the other measured properties, it makes our detector module very interesting for the next generation of space telescopes operating in the MeV range.

  8. Degradation of methyl bromide by methanotrophic bacteria in cell suspensions and soils

    Science.gov (United States)

    Oremland, R.S.; Miller, L.G.; Culbertson, C.W.; Connell, T.L.; Jahnke, L.

    1994-01-01

    Cell suspensions of Methylococcus capsulatus mineralized methyl bromide (MeBr), as evidenced by its removal from the gas phase, the quantitative recovery of Br- in the spent medium, and the production of 14CO2 from [14C]MeBr. Methyl fluoride (MeF) inhibited oxidation of methane as well as that of [14C]MeBr. The rate of MeBr consumption by cells varied inversely with the supply of methane, which suggested a competitive relationship between these two substrates. However, MeBr did not support growth of the methanotroph. In soils exposed to high levels (10,000 ppm) of MeBr, methane oxidation was completely inhibited. At this concentration, MeBr removal rates were equivalent in killed and live controls, which indicated a chemical rather than biological removal reaction. At lower concentrations (1,000 ppm) of MeBr, methanotrophs were active and MeBr consumption rates were 10-fold higher in live controls than in killed controls. Soils exposed to trace levels (10 ppm) of MeBr demonstrated complete consumption within 5 h of incubation, while controls inhibited with MeF or incubated without O2 had 50% lower removal rates. Aerobic soils oxidized [14C]MeBr to 14CO2, and MeF inhibited oxidation by 72%. Field experiments demonstrated slightly lower MeBr removal rates in chambers containing MeF than in chambers lacking MeF. Collectively, these results show that soil methanotrophic bacteria, as well as other microbes, can degrade MeBr present in the environment.

  9. The developmental toxicity of 1-methyl-3-octylimidazolium bromide on Daphnia magna.

    Science.gov (United States)

    Luo, Yan-Rui; Li, Xiao-Yu; Chen, Xiao-Xiao; Zhang, Bang-Jun; Sun, Zhen-Jun; Wang, Jian-Ji

    2008-12-01

    The developmental toxicity of 1-methyl-3-octylimidazolium bromide ([C(8)mim]Br) on Daphnia magna was investigated. The 24 and 48 h LC(50) values for [C(8)mim]Br in D. magna were 1.99 and 0.95 mg/L, respectively. A series of multigenerational toxicity tests were then used to explore [C(8)mim]Br effects in D. magna. [C(8)mim]Br significantly inhibited the body lengths of the F0 and F1 1st generations. After 21 days of exposure, [C(8)mim]Br lowered the reproductive ability of the F0 and F1 1st generations. In F1 3rd generation, 21 days of [C(8)mim]Br exposure prolonged the time to bear the first egg and the time to the first brood compared with the control, but the number of first-brood offspring and the number of broods produced by these animals were reduced. After the recovery period all the reproductive parameters returned to normal in F1 1st generation except for the number of broods. The dead neonates increased with prolonged exposure and increasing concentrations, and the dead neonates of the F1 3rd generation went far beyond that of the F1 1st and F0 generations. The intrinsic rate of natural increase (r) values of the three D. magna generations significantly decreased after exposure to higher concentrations of [C(8)mim]Br compared with control groups. Collectively, these results suggest that [C(8)mim]Br exerts a toxic effect on the development of D. magna. This study also highlights the importance of systematically evaluating the potential effects of aquatic ecosystems of ionic liquids that may be released into bodies of water. PMID:18442076

  10. Transport of atrazine versus bromide and δO18 in sand

    Science.gov (United States)

    Tindall, James A.; Friedel, Michael J.

    2016-01-01

    The objective of this research was to determine the process of atrazine transport compared to bromide and δO18 transport in sands near Denver. Three 1.5 × 2 × 1.5-m plots were installed and allowed to equilibrate for 2 years before research initiation and were instrumented with 1.5 × 2-m zero-tension pan lysimeters installed at 1.5-m depths. Additionally, each plot was instrumented with suction lysimeters, tensiometers, time domain reflectometry (TDR) moisture probes, and thermocouples (to measure soil temperature) at 15-cm depth increments. All plots were enclosed with a raised frame (of 8-cm height) to prevent surface runoff. During the 2-year period before research began, all suction and pan lysimeters were purged monthly and were sampled for fluids immediately prior to atrazine and KBr application to obtain background concentrations. Atrazine illustrated little movement until after a significant rainfall event, which peaked concentrations at depths of about 90 to 135 cm. Both Br− and δO18 moved rapidly through the soil, probably owing to soil porosity and anion exclusion for Br−. Concentrations of atrazine exceeding 5.0 μL−1 were observed with depth (90 to 150 cm) after several months. It appears that significant rainfall events were a key factor in the movement of atrazine in the sand, which allowed the chemicals to move to greater depths and thus avoid generally found biodegradation processes.

  11. Performance characteristics of single effect lithium bromide/ water absorption chiller for small data centers

    Science.gov (United States)

    Mysore, Abhishek Arun Babu

    A medium data center consists of servers performing operations such as file sharing, collaboration and email. There are a large number of small and medium data centers across the world which consume more energy and are less efficient when compared to large data center facilities of companies such as GOOGLE, APPLE and FACEBOOK. Such companies are making their data center facilities more environmental friendly by employing renewable energy solutions such as wind and solar to power the data center or in data center cooling. This not only reduces the carbon footprint significantly but also decreases the costs incurred over a period of time. Cooling of data center play a vital role in proper functioning of the servers. It is found that cooling consumes about 50% of the total power consumed by the data center. Traditional method of cooling includes the use of mechanical compression chillers which consume lot of power and is not desirable. In order to eliminate the use of mechanical compressor chillers renewable energy resources such as solar and wind should be employed. One such technology is solar thermal cooling by means of absorption chiller which is powered by solar energy. The absorption chiller unit can be coupled with either flat plate or evacuated tube collectors in order to achieve the required inlet temperature for the generator of the absorption chiller unit. In this study a modular data center is considered having a cooling load requirement of 23kw. The performance characteristics of a single stage Lithium Bromide/ water refrigeration is presented in this study considering the cooling load of 23kw. Performance characteristics of each of the 4 heat exchangers within the unit is discussed which helps in customizing the unit according to the users' specific needs. This analysis helps in studying the importance of different properties such as the effect of inlet temperatures of hot water for generator, inlet temperatures of cooling water for absorber and

  12. Antibacterial activity of starch/acrylamide/allyl triphenyl phosphonium bromide copolymers synthesized by gamma irradiation

    International Nuclear Information System (INIS)

    Starch/acrylamide/allyl triphenyl phosphonium bromide (St/AM/TP) copolymers were synthesized by simultaneous gamma irradiation and characterized by FTIR and 1H NMR techniques, weight measurement and titration method. Moreover, their antibacterial activities against Staphylococcus aureus were explored by the viable cell counting method in sterile distilled water. At St/AM/TP 6:8.4:5.6 g, copolymers with higher graft ratio (G) and higher (AM+TP) graft efficiency (EAM+TP) were obtained at 3 and 6 kGy, while cationic degree (CD) and TP graft efficiency (ETP) continuously increased with absorbed dose from 1 to 6 kGy. All of the copolymers were capable of killing >99.75% of 107 CFU/ml S. aureus within 30 mins. Moreover, at 3 kGy, G, EAM+TP and ETP increased with AM/TP from 0:14 to 11.2:2.8 g at St/(AM+TP) 6:14 g, while the optimum CD and antibacterial activity were achieved at AM/TP 7:7 and 8.4:5.6 g. In addition, at 3 kGy, G, EAM+TP and CD increased with St/(AM+TP) from 6:3 to 6:18 g at AM/TP 8.4:5.6 g, while the optimum antibacterial activity was achieved at 6:10 to 6:18 g, and the optimum ETP was achieved at 6:14. - Highlights: • Cationic starch is prepared from AM and TP by Gamma irradiation. • Cationic starch is characterized by FTIR, NMR, weight method and titration method. • Grafting ratio and cationic degree depend on absorbed dose and composition. • Cationic starch shows good antibacterial activity against Staphylococcus aureus

  13. Sol-gel Transition of Methylcellulose Solution in the Coexistence of Hexadecyltrimethylammonium Bromide and Sodium Chloride

    Institute of Scientific and Technical Information of China (English)

    Shah Zhou; Hai-yang Yang; Yong-jun Xie; Hua-zhen Li; Guang-ming Liu

    2011-01-01

    The sol-gel transition of methylcellulose (MC) solution in the presence of NaCl and hexadecyltrimethylammonium bromide (HTAB),together with MC/NaCl solution in the presence of HTAB and MC/HATB solution in the presence of NaCl,was investigated by the rheological measurements.It has been found that the sol-gel transition temperature of MC solution decreases linearly with the concentration of NaCl in solution but increases linearly with the concentration of HTAB in solution,respectively.However,the sol-gel transition temperature of MC/NaCl solution in the presence of HTAB keeps the same value,independent of the concentration of HTAB in solution.On the other hand,the sol-gel transition temperature of MC/HTAB solution decreases linearly with the concentration of NaCl in solution.The experimental results suggest that,for MC/NaCl solution in the presence of HTAB,the saltinduced spherical micelles of HTAB should have formed in bulk solution.For MC solution in the absence of NaCl,no spherical micelles have been formed in bulk solution,though the concentration of HTAB in our experiment is almost one order of magnitude higher than the critical micelle concentration of HTAB in polymer-free solution.In fact,due to adsorption of HTAB on MC chains,the realconcentration of HTAB in bulk solution,is much less than the apparent concentration of HTAB dissolved in MC solution.

  14. Spectroscopic study on the interaction of Bacillus subtilis α-amylase with cetyltrimethylammonium bromide

    International Nuclear Information System (INIS)

    The interaction between α-amylase from Bacillus subtilis and cetyltrimethylammonium bromide (CTAB) has been investigated at various temperature conditions using fluorescence and circular dichroism (CD) spectroscopic methods. Fluorescence data revealed that the fluorescence quenching of α-amylase by CTAB is the result of complex formation between CTAB and α-amylase. The thermodynamic analysis on the binding interaction data shows that the interactions are strongly exothermic (ΔHo=-17.92 kJ mol-1) accompanied with increase in entropy (ΔSo between 109 to 135 J mol-1 K-1). Thus the binding of CTAB to α-amylase is both enthalpic and entropic driven, which represent the predominate role of both electrostatic and hydrophobic interactions in complex formation process. The values of 2.17x10-3 M-1 and 1.30 have been obtained from associative binding constant (Ka) and stoichiometry of binding number (n), from analysis of fluorescence data, respectively. Circular dichroism spectra showed the substantial conformational changes in secondary structure of α-amylase due to binding of CTAB, which represents the complete destruction of both secondary and tertiary structure of α-amylase by CTAB. - Research highlights: → The Fluorescence quenching effect of α-amylase by CTAB is a consequence of formation α-amylase-CTAB complex. → The α-helical analyzing from the CD spectra in the various concentration of CTAB shows strongly deformation of α-amylase. → Thermodynamic analysis of quenching verify that the interactions are both enthalpy and entropic driven.

  15. Temperature effect on the transport of bromide and E. coli NAR in saturated soils

    Science.gov (United States)

    Gharabaghi, B.; Safadoust, A.; Mahboubi, A. A.; Mosaddeghi, M. R.; Unc, A.; Ahrens, B.; Sayyad, Gh.

    2015-03-01

    In this study we investigated the transport of nalidixic acid-resistant Escherichia coli (E. coli NAR) and bromide (Br-) through two soils, a sandy loam (SL) and clay loam (CL). Soils were repacked in columns (45 cm length × 22 cm diameter) and subjected to physical (freeze/thaw, and wet/dry cycles) and biological (by earthworms, Eisenia fetida) weathering for 12 months. Saturated flow conditions were maintained using a tension infiltrometer. Tests were carried out at either 5 or 20 °C. After steady-state flow conditions were established, a suspension containing E. coli NAR and Br- was sprayed onto the surface of soil columns. Leachate was sampled at three depths, 15, 30 and 45 cm. Time to maximum concentration (Cmax) of E. coli NAR was greater for SL at all depths. Both tracers had rapid breakthrough curves (BTCs) shortly after the suspension injection followed by prolonged tailing indicating the presence of preferential pathways and thus soil heterogeneity regenerated after the induced physical and biological weathering. About 40% of the E. coli NAR and 79% of the Br- leached through the entire 45 cm soil columns during the experiments. Leaching with cold water (5 °C) led to lower hydraulic conductivity and flow rate and consequently enhanced bacterial filtration for both soils. Very low values for the detachment coefficient for E. coli NAR at 5 °C suggest an irreversible process of bacterial attachment in heterogeneous soils. BTCs were well described by the mobile-immobile model (MIM) in HYDRUS-1D. Soil texture/structure and temperature had a significant effect on the model's fitted parameters.

  16. A comparison of the use of sodium iodide and lanthanum bromide scintillation crystals for airborne surveys

    Science.gov (United States)

    Bailey, Derek M.

    The Environmental Protection Agency (EPA) Aerial Spectral Environmental Collection Technology (ASPECT) program performs aerial radiological and chemical characterization of geographical regions of interest. Airborne surveys are performed to characterize environmental radionuclide content, for mineral exploration, as well as for emergency scenarios such as major releases or lost sources. Two radiological detection systems are used by the ASPECT team for gamma-ray detection and characterization: lanthanum bromide [LaBr 3(Ce)] and sodium iodide [NaI(Tl)] scintillation systems. An aerial survey of a uranium mine in the western United States was performed using both NaI(Tl) and LaBr3(Ce) detection systems. Analyses of the survey data were performed with RadAssist software and applying International Atomic Energy Agency (IAEA) airborne gamma ray mapping guidelines. The data for the survey were corrected for cross-over, which is spectral interference from higher energy photons as a result of Compton scattering, height attenuation, cosmic ray contribution to signal, and Radon contribution to signal. Two radiation survey contours were generated from each discrete data set. Based on analysis of the uranium mine survey results, LaBr3(Ce) produced a product comparable to that of NaI(Tl). The LaBr3(Ce) detection system contained 1/16th the scintillating volume and had a total system weight that was 1/4th that of the NaI(Tl) system. LaBr3(Ce) demonstrated a clear advantage over NaI(Tl) detectors in system mobility, and weight factors in airborne gamma ray spectroscopy.

  17. Rearrangement reaction of the hydroxyl group of ω-hydroxy-alkyltriphenyl phosphonium bromides

    Institute of Scientific and Technical Information of China (English)

    何美玉; 袁谷; 贺晓然

    2000-01-01

    No molecular ion peak from the Electron Impact Ionization of eight ω-hydroxyalkyltriphenyl phosphonium bromides (Ph3P+ (CH2)nOHBr, n = 2-6, 8--10) can be found, except a part of some relative powerful fragment ions can be observed only. Each c ompound forms a very characteristic ion (O= PPh3- 1)+ atm/z 277throughhydryl rearrangement reaction. The intensity of this ion is closely related with the size of the carbon chain of hydroxyalkyl and with temperature of ion source and temperature of sample probe. The above rearrangement reaction and the reaction to form ion at m/ z 262 take place simultaneonsly, thus leading to strong competition.At n =2, ion at m/z 277 is the most powerful and becomes continuously the base peak. At n = 3 and n = 4, the intensity of ion at m/z 262 reaches the maximum, and is always the base peak, and the relative abundance of m/z 277 is only around 2%. At n = 5, 6, 8, 9, 10, m/z 277 becomes base peak when the temperature of probe is below 300°C. But, when the temperature increases from 300°C to 350°C, m/z 262 suddenly becomes the base peak, which is not in direct proportional relation with the size of carbon chain. It is proved by MIKES and accurate mass that ion at m/z 277 produces a fragment ion (O= PPh2-2)+ at m/z 199 with the loss of the neutral benzene molecule.

  18. Spectroscopic study on the interaction of Bacillus subtilis {alpha}-amylase with cetyltrimethylammonium bromide

    Energy Technology Data Exchange (ETDEWEB)

    Omidyan, R., E-mail: r.omidyan@sci.ui.ac.i [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Kazemi, S.H. [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of); Bordbar, A.K. [Department of Chemistry, University of Isfahan, Isfahan 81746-73441 (Iran, Islamic Republic of); Zaynalpour, S. [Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731 (Iran, Islamic Republic of)

    2011-06-15

    The interaction between {alpha}-amylase from Bacillus subtilis and cetyltrimethylammonium bromide (CTAB) has been investigated at various temperature conditions using fluorescence and circular dichroism (CD) spectroscopic methods. Fluorescence data revealed that the fluorescence quenching of {alpha}-amylase by CTAB is the result of complex formation between CTAB and {alpha}-amylase. The thermodynamic analysis on the binding interaction data shows that the interactions are strongly exothermic ({Delta}H{sup o}=-17.92 kJ mol{sup -1}) accompanied with increase in entropy ({Delta}S{sup o} between 109 to 135 J mol{sup -1} K{sup -1}). Thus the binding of CTAB to {alpha}-amylase is both enthalpic and entropic driven, which represent the predominate role of both electrostatic and hydrophobic interactions in complex formation process. The values of 2.17x10{sup -3} M{sup -1} and 1.30 have been obtained from associative binding constant (K{sub a}) and stoichiometry of binding number (n), from analysis of fluorescence data, respectively. Circular dichroism spectra showed the substantial conformational changes in secondary structure of {alpha}-amylase due to binding of CTAB, which represents the complete destruction of both secondary and tertiary structure of {alpha}-amylase by CTAB. - Research highlights: {yields} The Fluorescence quenching effect of {alpha}-amylase by CTAB is a consequence of formation {alpha}-amylase-CTAB complex. {yields} The {alpha}-helical analyzing from the CD spectra in the various concentration of CTAB shows strongly deformation of {alpha}-amylase. {yields} Thermodynamic analysis of quenching verify that the interactions are both enthalpy and entropic driven.

  19. Binding-Induced Fluorescence of Serotonin Transporter Ligands

    DEFF Research Database (Denmark)

    Wilson, James; Ladefoged, Lucy Kate; Babinchak, Michael;

    2014-01-01

    The binding-induced fluorescence of 4-(4-(dimethylamino)-phenyl)-1-methylpyridinium (APP(+)) and two new serotonin transporter (SERT)-binding fluorescent analogues, 1-butyl-4-[4-(1-dimethylamino)phenyl]-pyridinium bromide (BPP(+)) and 1-methyl-4-[4-(1-piperidinyl)phenyl]-pyridinium (PPP(+)), has ...

  20. Direct injection, simple and robust analysis of trace-level bromate and bromide in drinking water by IC with suppressed conductivity detection.

    Science.gov (United States)

    Lawal, Wasiu; Gandhi, Jay; Zhang, Chunlong Carl

    2010-08-01

    Bromide is ubiquitously found in drinking water. It is introduced into source water primarily by contact with bromide-containing soils or seawater having high bromide content. Bromide is converted into carcinogenic bromate during ozonation processes employed in some drinking water and wastewater treatment plants. Therefore, monitoring of bromate in drinking water and its precursor bromide in source water is required. The purpose of this study was to survey bromide and bromate concentrations in randomly selected bottle waters of various brands and several tap water samples in the coastal Houston area using a direct-injection ion chromatography (IC) and a suppressed conductivity system. The method employs a simple isocratic IC with loop injection with calculated detection limit of 0.009 microg/L for bromate and 0.028 microg/L for bromide (250-microL sample volume). Allowing the detection of both species at the microg/L level in drinking water, this method does not require specialized instrumentation such as two-dimensional IC, expensive sample preparation, or post-column reactions. The results show that, whereas bromate remains undetected in all five tap water samples, there are significant high concentrations of bromide in the coastal Houston area (294.79 +/- 56.97 microg/L). Its link to potential seawater intrusion need to be further investigated. For bottle water samples randomly collected, 18.2% (2 out of 11) showed detectable amount of both bromide and bromate. The detection of bromate coincides with those bottle water samples that underwent ozonation treatment. Further sample campaign with exclusively ozonated bottle water samples (n = 19) showed 100% detection rate for both bromide and bromate. The 99% confidence intervals were 14.45-37.97 microg/L and 0.32-2.58 microg/L for bromide and bromate, respectively. The highest level of bromate among all ozonated bottle water samples was 7.57 microg/L, a concentration close to the U.S. EPA prescribed limit for

  1. Modelling the site of bromide binding in vanadate-dependent bromoperoxidases.

    Science.gov (United States)

    Kraehmer, Verena; Rehder, Dieter

    2012-05-01

    Treatment of Boc-protected (S)-serine (Ser) methyl ester with triphenylphosphine bromide Ph(3)PBr (intermittently generated from PPh(3) and N-bromosuccinimide) yields Boc-3-bromoalanine (R)-Boc-BrAlaMe and, after deprotection, bromoalanine methyl ester (R)-BrAlaMe in the form of its hydrobromide. Boc-BrAlaMe and BrAlaMe have been structurally characterised. The reaction between BrAlaMe, salicylaldehyde (sal) and VO(2+) results in the formation of Schiff base complexes of composition [VO(sal-BrAlaMe)solv](+) (solv = CH(3)OH: 3, THF: 5) and [VO(sal-BrAla)THF] 4. DFT calculations of the structures of 3, 4 and 5, based on the B3LYP functional and employing the triple zeta basis set 6-311++g(d,p), provide distances Br···V = 4.0 ± 0.1 Å, if some distortion of the dihedral angle ∠N-C-C-Br is allowed (affording a maximum energy of ca. 45 kJ mol(-1)), and thus model Br···V distances detected by X-ray methods in bromoperoxidases from the marine algae Ascophyllum nodosum and Corallina pilulifera. The DFT calculations have been validated by comparing calculated and found structures, including the new complex [V(V)O(Amp-sal)OMe(MeOH)] (1, Amp is the aminophenol moiety) and the known complex [VO(L-Ser-van)H(2)O] (van = vanillin). Additional validation has been undertaken by checking experimental against calculated (BHandHLYP) EPR spectroscopic hyperfine coupling constants. Complexes containing bromine as a substituent at the phenyl moiety of a Schiff base ligand do not allow for an appropriate simulation of the Br···V distance in peroxidases. The closest agreement, d(Br···V) = 4.87 Å, is achieved with [VO(3Br-salSer)THF] (6), where 3Brsal-Ser is the dianionic Schiff base formed between 3-Br-5-NO(2)-salicylaldehyde and serine. PMID:22415551

  2. Formation of bromate during ferrate(VI) oxidation of bromide in water.

    Science.gov (United States)

    Huang, Xin; Deng, Yang; Liu, Shuang; Song, Yali; Li, Nanzhu; Zhou, Jizhi

    2016-07-01

    Ferrate (VI) is traditionally recognized as a safe oxidant without production of disinfection byproducts (DBPs). However, here we detected probable carcinogenic bromate (BrO3(-)) during ferrate(VI) oxidation of bromide (Br(-))-containing water, and evaluated the effects of pH, ferrate(VI) dose, initial Br(-) concentration, and co-existing anions on the BrO3(-) formation. BrO3(-) was produced at a moderately-weakly acidic pH condition and in the absence of phosphate that was commonly applied as a buffer and stabilizing agent in previous ferrate(VI) studies. At pH 5.0, the produced BrO3(-) was increased from 12.5 to 273.8 μg/L with the increasing initial Br(-) concentration from 200 to 1000 μg/L at 10 mg/L Fe(VI), corresponding to an increase in the molar conversion ([BrO3(-)]/initial [Br(-)]) from 2.3% to 10.3%, in a bicarbonate-buffered solution. As pH increased to 7.0, the BrO3(-) concentration gradually dropped. The BrO3(-) production appeared to be associated with the oxidation by high valence iron species (i.e. Fe(VI), Fe(V) and Fe(IV)). Two key intermediate products (i.e. hypobromous acid/hypobromite (HOBr/OBr(-)) and hydrogen peroxide (H2O2)) relevant to the bromate formation were identified. The production of HOBr, a requisite intermediate for the ensuing bromate formation, was indirectly validated through identification of bromine-containing trihalomethanes and haloacetic acids during ferrate oxidation in a natural water, though these bromo-organic DBPs produced were insignificant. Furthermore, the inhibition effects of various anions on the formation of BrO3(-) followed chloride H2O2 was detected at higher phosphate concentration. It could reduce HOBr to Br(-), thereby inhibiting the bromate formation. PMID:27153235

  3. Effect of pinaverium bromide on stress-induced colonic smooth muscle contractility disorder in rats

    Institute of Scientific and Technical Information of China (English)

    Yun Dai; Jian-Xiang Liu; Jun-Xia Li; Yun-Feng Xu

    2003-01-01

    AIM: To investigate the effect of pinaverium bromide, a Ltype calcium channel blocker with selectivity for the gastrointestinal tract on contractile activity of colonic circular smooth muscle in normal or cold-restraint stressed rats and its possible mechanism.METHODS: Cold-restraint stress was conducted on rats to increase fecal pellets output. Each isolated colonic circular muscle strip was suspended in a tissue chamber containing warm oxygenated Tyrode-Ringer solution. The contractile response to ACh or KCl was measured isometrically on inkwriting recorder. Incubated muscle in different concentrations of pinaverium and the effects of pinaverium were investigated on ACh or KCl-induced contraction. Colon smooth muscle cells were cultured from rats and [Ca2+]i was measured in cell suspension using the Ca2+ fluorescent dye fura-2/AlMl.RESULTS: During stress, rats fecal pellet output increased 61% (P<0.01). Stimulated with ACh or KCl, the muscle contractility was higher in stress than that in control. Pinaverium inhibited the increment of [Ca2+]i and the muscle contraction in response to ACh or KCl in a dose dependent manner. A significant inhibition of pinaverium to ACh or KCl induced [Ca2+]i increment was observed at 10-6 mol/L. The IC50 values for inhibition of ACh induced contraction for the stress and control group were 1.66×10-6 mol/L and 0.91×10-6mol/L, respectively. The ICs0 values for inhibition of KCl induced contraction for the stress and control group were 8.13×10-7 mol/L and 3.80×10-7 mol/L, respectively.CONCLUSION: Increase in [Ca2+]i of smooth muscle cells is directly related to the generation of contraction force in colon. L-type Ca2+ channels represent the main route of Ca2+ entry.Pinaverium inhibits the calcium influx through L-type channels;decreases the contractile response to many kinds of agonists and regulates the stress-induced colon hypermotility.

  4. Tiotropium bromide in the routine care of GOLD stage II COPD patients: a pharmaeconomic evaluation

    Directory of Open Access Journals (Sweden)

    Orietta Zaniolo

    2011-06-01

    Full Text Available Background: a secondary pre-specified analysis of the UPLIFT cohort demonstrated that the inclusion of tiotropium bromide in the routine care of GOLD stage II (moderate chronic obstructive pulmonary disease (COPD patients is associated with stronger improvements of survival, quality of life, and exacerbation rate than those shown in the total cohort; in this subgroup, tiotropium furthermore induces a significant reduction in the rate of FEV1 decline.Objective: to adapt the Spiriva® model, originally built to evaluate cost-effectiveness of tiotropium inclusion in the general COPD population, to GOLD II patients.Methods: the Spiriva® model is a probabilistic Markov patient-level simulation developed over a lifetime horizon to compare outcomes associated with the inclusion of tiotropium in routine care (RC for COPD treatment with those obtained with RC alone. Patients are characterised by gender, age, height, smoking status and FEV1. Model structure and sources have been maintained unvaried, except for demographic characteristics, specific for GOLD II patients, as extrapolated from an Italian observational study, and tiotropium efficacy, based on the secondary analysis of GOLD II UPLIFT patients. As in the original model, only direct health care costs are considered.Results: patients treated with tiotropium on average (95% CI gain 0.70 (0.00/7.23 LYs or 0.77 (0.02/4.67 QALYs compared to RC. The incremental lifetime cost is € 3,520 (-6,391/26,686, meaning that the incremental cost required to gain a QALY (incremental cost-effectiveness ratio – ICER is equal to € 4,548. Sensitivity analysis shows that tiotropium has a 50% probability of being cost-effective for a willingness-to-pay (WTP around 4,600 €/QALY; 100% probability is achieved with a WTP of € 9,300.Conclusions: the adoption of a strategy based on the inclusion of tiotropium from the early COPD stages represents good value for money in Italy, as the ICER estimated for GOLD II

  5. COMPARISON OF ONSET TIME, DURATION OF ACTION AND INTUBATING CONDITION SACHIEVED WITH SUXAMETHONIUM AND ROCURONIUM BROMIDE

    Directory of Open Access Journals (Sweden)

    Ajit P

    2013-12-01

    Full Text Available Adverse event profile ofSuxamethonium which is still the relaxant of choice to facilitate tracheal intubation inspired us to conduct a study in which we compared Onset time, Duration of Action and Intubating Conditions Achieved with Suxametho nium and Rocuronium Bromide with the Help of TOF Guard. AIMS : W e compared the onset of relaxation time, intubating condition, and duration of action, the cardiovascular effect, side effects between Suxamethonium and Rocuronium to ascertain the place of Rocu ronium as a relaxant for rapid sequence intubation as compared to the Suxamethonium. METHODS AND MATERIAL : The present study was carried out with the association of Department of Anesthesiology, S.S. Medical College and Associated S.G.M. and G.M. Hospitals, Rewa (M.P., and Departmen t of Pharmacology NSCB Medical C ollege Jabalpur (M.P. in 100 patients of either sex of ASA grade I and II between the ages of 16 to 70 years. The patients were randomly divided in two groups of 50 each. Group I & II received Sux amethonium 1.5 mg/kg B.W. or Rocuronium 1.0 mg/kg B.W. RESULTS : Onset time of maximum relaxation is < 60 seconds in each relaxants under study i.e. Rocuronium 1 mg/kg and Suxamethonium 1.5 mg/kg. Intubating conditions after Rocuronium 1 mg/kg are clinically acceptable in 100% of cases and are equivalent to that after Suxamethonium 1.5 mg/kg. Rocuronium upto dose of 1 mg/kg does not have any clinically significant cardiovascular effect. Rocuronium does not have any side effects including the sign of histamine release and anaphylactic or anaphylactoid reactions. Duration of action after Rocuronium 1 mg/kg is about 2346.4 seconds (39.14 minutes so it is not suitable for surgeries of short duration. CONCLUSIONS : Rocuronium can replace Suxamethonium for rapid sequ ence intubation in conditions where use of Suxamethonium is eithe r hazardous or contraindicated p rovided there is no anticipated difficulty in intubation.

  6. Once-daily glycopyrronium bromide, a long-acting muscarinic antagonist, for chronic obstructive pulmonary disease: a systematic review of clinical benefit

    Directory of Open Access Journals (Sweden)

    Ulrik CS

    2012-09-01

    Full Text Available Charlotte Suppli UlrikDepartment of Pulmonary Medicine, Hvidovre Hospital and University of Copenhagen, Copenhagen, DenmarkBackground: Long-acting bronchodilators are central in the pharmacological management of patients with chronic obstructive pulmonary disease (COPD. The aim of this systematic review is to provide an overview of the studies evaluating the safety and clinical efficacy of inhaled glycopyrronium bromide, a novel long-acting muscarinic antagonist, in patients with COPD.Methods: This study was performed as a systematic literature review.Results: Inhaled glycopyrronium bromide seems to be a safe and well tolerated long-acting muscarinic antagonist with a fast onset of action. In patients suffering from moderate to severe COPD, glycopyrronium bromide has clinically important effects on level of forced expiratory volume in one second, use of relief medication, percentage of days with no use of rescue medication, daytime dyspnea scores, and probably also on health status. Furthermore, in this group of patients, glycopyrronium bromide has beneficial effects on dynamic hyperinflation and exercise tolerance. Glycopyrronium bromide has been shown to reduce the rate of exacerbations in patients with moderate to severe COPD, but long-term controlled trials with exacerbation rate as the primary outcome variable have not been published yet.Conclusion: Once-daily inhaled glycopyrronium bromide has characteristics important for use in COPD, including a fast onset of action, sustained 24-hour bronchodilatation, and improvement in exercise tolerance, and therefore appears to have the potential for a significant role in the future management of COPD.Keywords: chronic obstructive pulmonary disease, glycopyrronium bromide, long-acting bronchodilators

  7. CdTe quantum dots functionalized with 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide as luminescent nanoprobe for the sensitive recognition of bromide ion

    Energy Technology Data Exchange (ETDEWEB)

    Adegoke, Oluwasesan [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa); Hosten, Eric; McCleland, Cedric [Department of Chemistry, Nelson Mandela Metropolitan University (South Campus), Port Elizabeth 6031 (South Africa); Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za [Department of Chemistry, Rhodes University, Grahamstown 6140 (South Africa)

    2012-04-06

    Graphical abstract: A bromide ion-selective modified nanoprobe sensor based on 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4AT)-functionalized CdTe quantum dots (QDs-4AT) showed a high selectivity and sensitivity for the determination of bromide ion using fluorescence recovery. Highlights: Black-Right-Pointing-Pointer Water soluble CdTe quantum dots interact with tetramethylpiperidine-N-oxide. Black-Right-Pointing-Pointer Quantum dots fluorescence is quenched by the radical. Black-Right-Pointing-Pointer In the presence of bromide ions the fluorescence is restored. Black-Right-Pointing-Pointer The sensor is more selective to bromine ions than other common ions. - Abstract: A novel bromide ion-selective modified nanoprobe sensor based on 4-amino-2,2,6,6-tetramethylpiperidine-N-oxide (4AT)-functionalized CdTe quantum dots (QDs-4AT) has been developed. Fluorescence quenching of the QDs by 4AT was observed. The functionalized QDs-4AT nanoprobe allowed a highly sensitive determination of bromide ion via analyte-induced change in the photoluminescence (fluorescence recovery) of the modified QDs. A detection limit of 0.6 nM of bromide ion was obtained, while the interfering effect of other inorganic cations and anions was investigated to examine the selectivity of the nanoprobe. The linear range was between 0.01 and 0.13 {mu}M. Combined fluorescence lifetime and electron paramagnetic resonance measurements confirmed electron transfer processes between bromide ion and QDs-4AT.

  8. Titrimetric, spectrophotometric and kinetic methods for the assay of atenolol using bromate–bromide and methyl orange

    Directory of Open Access Journals (Sweden)

    KANAKAPURA BASAVAIAH

    2006-05-01

    Full Text Available Three new methods have been developed for the determination of atenolol in bulk drug and in tablet formulation. The methods are based on the oxidation–bromination reaction of the drug by bromine, generated in situ by the action of acid on a bromate–bromide mixture. In the titrimetric method, the drug is treated with a known excess of bromate–bromide mixture in hydrochloric acid medium, followed by the determination of the unreacted bromine iodometrically. The spectrophotometric method involves the addition of a measured excess of bromate–bromide reagent in hydrochloric acid medium to atenolol, and after ensuring the reaction had gone to completion, the unreacted bromine is treated with a fixed amount of methyl orange, and absorbance measured at 520 nm. The absorbance was found to increase linearly with increasing concentration of atenolol. The kinetic method depends on the existence of a linear relationship between the concentration of the drug and the time of the oxidation–bromination reaction, as indicated by the bleaching of methyl orange acid colour. The working conditions were optimized. The titrimetric method is based on a 1:1 reaction stoichiometry (atenolol:bromate and is applicable over the 3–20 mg range. The spectrophotometric method permits micro determination of the drug (0.5–4.0 mg ml-1with an apparentmolar absorptivity of 4.13x104 lmol-1 cm-1 and detection limit of 0.07 mg ml-1. The kinetic method is applicable in the concentration range 5–25 mg ml-1 with a detection limit of 3.72 mg ml-1. The proposed methods were successfully applied to the determination of atenolol in tablet preparations with mean recoveries of 97.63 to 101.78 %. The reliability of the assay was established by parallel determination by the reference method and by recovery studies using the standard addition technique.

  9. Synthesis, characterization and thermal properties of new aromatic quaternary ammonium bromides: precursors for ionic liquids and complexation studies

    Science.gov (United States)

    Busi, Sara; Lahtinen, Manu; Ropponen, Jarmo; Valkonen, Jussi; Rissanen, Kari

    2004-10-01

    Series of new aromatic R2R‧2N+Br- (R=benzyl, 4-methylbenzyl, 2-phenylethyl, 3-phenylpropyl; R‧=ethyl, methyl, isopropyl) or RR‧2NH+Br--type (R=benzyl, R‧=isopropyl) quaternary ammonium bromides were prepared by using novel synthetic route in which a formamide (N,N-diethylformamide, N,N-dimethylformamide, N,N-diisopropylformamide) is treated with aralkyl halide in presence of a weak base. The compounds were characterized by 1H-NMR and 13C-NMR spectroscopy and mass spectrometry. Structures of the crystalline compounds were determined by X-ray single crystal diffraction, and in addition the powder diffraction method was used to study the structural similarities between the single crystal and microcrystalline bulk material. Three of the compounds crystallized in monoclinic, two in orthorhombic and one in triclinic crystal system, showing ion pairs, which are interconnected by weak hydrogen bonds and weak π - π interactions between the phenyl rings. Three of the compounds appeared as viscous oil or waxes. Finally, TG/DTA and DSC methods were used to analyze thermal properties of the prepared compounds. The lowest melting points were obtained for diethyldi-(2-phenylethyl)ammonium bromide (122.2 °C) and for diethyldi-(3-phenylpropyl)-ammonium bromide (109.1 °C). In general, decomposition of the compounds started at 170-190 °C without identifiable cleavages, thus liquid ranges of 30-70 °C were observed for some of the compounds.

  10. A comparison of didodecyldimethylammonium bromide adsorbed at mica/water and silica/water interfaces using neutron reflection.

    Science.gov (United States)

    Griffin, Lucy R; Browning, Kathryn L; Truscott, Chris L; Clifton, Luke A; Webster, John; Clarke, Stuart M

    2016-09-15

    The layer structure of the dichain alkyl ammonium surfactant, didodecyldimethylammonium bromide (DDAB), adsorbed from water on to silica and mica surfaces has been determined using neutron reflection. Although sometimes considered interchangeable surfaces for study, we present evidence of significant differences in the adsorbed layer structure below the critical micelle concentration. A complete DDAB bilayer was assembled at the water/mica interface at concentrations below the critical micelle concentration (CMC). In contrast it is not until the CMC was reached that the complete bilayer structure formed on the oxidised silicon crystal. Removal of the complete bilayer on both surfaces was attempted by both washing and ion exchange yet the adsorbed structure proved tenacious.

  11. Efficacy and safety of eco-friendly inhalers: focus on combination ipratropium bromide and albuterol in chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Panos RJ

    2013-04-01

    Full Text Available Ralph J Panos1,2 1Pulmonary, Critical Care, and Sleep Medicine Division, Cincinnati Veterans Affairs Medical Center, 2Pulmonary, Critical Care, and Sleep Medicine Division, University of Cincinnati College of Medicine, Cincinnati, OH, USA Background: Chronic obstructive pulmonary disease (COPD is a major cause of morbidity and mortality and its treatment is critical to improve quality of life, reduce symptoms, and diminish the frequency of COPD exacerbations. Due to the harmful environmental effects of pressurized metered-dose inhalers (pMDIs containing chlorofluorocarbons (CFCs, newer systems for delivering respiratory medications have been developed. Methods: A search of the literature in the PubMed database was undertaken using the keywords “COPD,” “albuterol,” “ipratropium bromide,” and “Respimat® Soft Mist Inhaler™”; pertinent references within the identified citations were included. The environmental effect of CFC-pMDIs, the invention of the Respimat® Soft Mist Inhaler™ (SMI (Boehringer Ingelheim, Ingelheim, Germany, and its use to deliver the combination of albuterol and ipratropium bromide for the treatment of COPD were reviewed. Results: The adverse environmental effects of CFC-pMDIs stimulated the invention of novel delivery systems including the Respimat SMI. This review presents its development, internal mechanism, and use to deliver the combination of albuterol and ipratropium bromide. Conclusion: CFC-pMDIs contributed to the depletion of the ozone layer and the surge in disorders caused by harmful ultraviolet B radiation. The banning of CFCs spurred the development of novel delivery systems for respiratory medications. The Respimat SMI is an innovative device that produces a vapor of inhalable droplets with reduced velocity and prolonged aerosol duration that enhance deposition within the lower airway and is associated with improved patient satisfaction. Clinical trials have demonstrated that the Respimat SMI

  12. Non-conservative behavior of bromide in surface waters and brines of Central Andes : a release into the atmosphere ?

    OpenAIRE

    Risacher, François; Fritz, B; Alonso, H.

    2006-01-01

    The transfer of reactive bromine into the atmosphere was recently observed by Honninger et al. [Honninger, G., Bobrowski, N., Palenque, E.R., Torrez, R., Platt, U., 2004. Reactive bromine and sulfur emission at salar de Uyuni, Bolivia. Geophys. Res. Lett. 31, doi:10.1029/2003GL018818] in a large salt pan of the Bolivian Altiplano: the salar de Uyuni. However, bromide is considered to be an excellent conservative tracer, which leads to the questioning of its actual conservation in surficial ge...

  13. The application of pancuronium bromide (Pavulon) forensic analyses to tissue samples from an "Angel of Death" investigation.

    Science.gov (United States)

    Andresen, Brian D; Alcaraz, Armando; Grant, Patrick M

    2005-01-01

    The case report of a serial killer who worked at several hospitals as a respiratory therapist is presented. The suspect was initially labeled a benevolent Angel of Death who ended the suffering of elderly patients through mercy killing. However, his subsequently declared motive for homicide was very different from other similar cases in medical settings. The application of new analysis techniques for the detection of pancuronium bromide in a series of aged exhumation tissues gave positive results and led to the resultant conviction of the therapist.

  14. Solid-phase plate-reader quantification of specific PCR products by measurement of band-specific ethidium bromide fluorescence.

    Science.gov (United States)

    McCarthy, Michael T; O'Callaghan, Christopher A

    2014-02-15

    Real-time PCR is widely employed to quantify PCR products across a range of applications. However, accurate real-time PCR is not always technically feasible, and alternative methods for PCR product quantification can be expensive and time consuming to validate. We have developed an inexpensive, rapid, and immediately accessible protocol to quantify PCR products, by measuring ethidium bromide fluorescence of PCR products excised from agarose gels. This protocol has relevance to a broad range of methods in molecular biology where quantification of PCR products is necessary.

  15. Motor effects of locally administered pinaverium bromide in the sigmoid tract of patients with irritable bowel syndrome.

    Science.gov (United States)

    Passaretti, S; Sorghi, M; Colombo, E; Mazzotti, G; Tittobello, A; Guslandi, M

    1989-01-01

    The effects of pinaverium bromide, a non-absorbable antispasmodic agent, administered locally, on sigmoid-rectal motility was investigated in 20 patients with irritable bowel syndrome. The influence of either pinaverium (10 subjects) or placebo (10 subjects) on a neostigmine-induced increase of sigmoid pressure was assessed and compared by means of computerized electromanometry. The drug was found to counteract significantly the motor effects of neostigmine, thus appearing to be an effective compound for the treatment of functional disorders of the colon. PMID:2744907

  16. 1-Carboxymethyl-1′-carboxylatomethyl-3,3′-[p-phenylenebis(oxymethylene]dipyridinium bromide dihydrate

    Directory of Open Access Journals (Sweden)

    Wei-Cheng Pan

    2010-10-01

    Full Text Available In the crystal structure of the title salt, C22H21N2O6+·Br−·2H2O, pairs of betaine molecules are bridged by protons (the bridging proton is disordered, forming strong and symmetrical O—H...O hydrogen bonds, leading to an infinite chain along the b axis. The water molecules are linked to the betaine molecule and the bromide ion through O—H...O and O—H...Br interactions. The central ring, located on an inversion centre, makes dihedral angles of 1.2 (2° with the outer rings. One of the carboxylic acid groups is deprotonated.

  17. Study of the Ion Channel Behavior of Didodecyldimethylammonium Bromide Formed Bilayer Lipid Membrane Stimulated by PF-6

    Institute of Scientific and Technical Information of China (English)

    TONG,Yue-Hong; HAN,Xiao-Jun; WANG,Er-Kang

    2003-01-01

    Bilayer lipid membranes ( BLM ) formed from didodecyldimethylammonium bromide were made on the freshly exposed surface ofa glassy carbon (GC) ani were demonstrated by the ac impedance spectroscopy. The ion channels of membrane properties induced by PF6- were studied by the cyclic voltammetric methods.Experimental results indicated that the ion channel of BLM was open in the presence of the PF6- due to the interaction of PF6- with the BLM, while it was switched offin the absence of PF6-. Because the ion channel behavior was affected by the concentration of PF6-,a sensor for PF6- can be developed.

  18. New air-stable planar chiral ferrocenyl monophosphine ligands: Suzuki cross-coupling of aryl chlorides and bromides

    DEFF Research Database (Denmark)

    Jensen, Jakob Feldthusen; Johannsen, Mogens

    2003-01-01

    GraphicA novel class of planar chiral electron-rich monophosphine ligands has been developed. The modular design allows a short and efficient synthesis of an array of aryl-ferrocenyl derivatives carrying the donating bis(dicyclohexyl)phosphino moiety. These new ligands have successfully been appl...... applied in the palladium-catalyzed Suzuki cross-coupling of activated as well as nonactivated aryl chlorides at room temperature. The asymmetric coupling of an aryl bromide and an aryl boronic acid was also tested, giving ees up to 54%....

  19. 罗库溴铵合成路线图解%Graphical Synthetic Routes of Rocuronium Bromide

    Institute of Scientific and Technical Information of China (English)

    严慧; 邱飞; 刁勇

    2011-01-01

    @@ 罗库溴铵(rocuronium bromide,1),化学名为1-[(2β,3α,5α,16β,17β)-17-(乙酰氧基)-3-羟基-2-(4-吗啉基)雄甾烷-16-基]-1-(2-丙烯基)吡咯烷鎓溴化物,是荷兰Organon公司研发的一种非去极化甾醇类肌肉松弛药,1994年6月首次在美国上市.

  20. Investigation of Surfactant-Stain-Metal Interaction: Naphthochrome Green/Cetyltrimethylammonium Bromide/Rare Earths Ternary Complexation

    Institute of Scientific and Technical Information of China (English)

    郑立新; 沈荣; 郜洪文

    2003-01-01

    The ternary interaction of naphthochrome green (NCG) with cetyltrimethylammonium bromide (CTAB) and rare earths (Res: Yb, Dy, Er and Eu) has been investigated with the microsurface adsorption-spectral correction technique (MSASC). The aggregation of NCG on CTAB obeys the Langmuir isothermal adsorption. The enrichment of NCG on CTAB and the presence of NaCl sensitize the complexation between Res and NCG. Both the binary aggregate and the ternary complex were characterized in the presence and absence of NaCl at pH 8.30 at 20 and 40℃.

  1. Role of intravenously administered hyoscine butyl bromide in retrograde terminal ileoscopy: A randomized, double-blinded, placebo-controlled trial

    Institute of Scientific and Technical Information of China (English)

    SP Misra; M Dwivedi

    2007-01-01

    AIM:To evaluated the role of hyoscine butyl bromide in facilitating retrograde ileoscopy.METHODS:Retrograde terminal ileoscopy was attempted in 200 consecutive patients undergoing colonoscopy. After intubation of the cecum and visualization of the ileocecal valve,butyl bromide injection or normal saline was given intravenously to the patients in a double blind random fashion. The pulse rate and oxygen saturation were measured continuously. After completion of the procedure,endoscopists were then asked to score the ease of intubation and the ease of visualization of the terminal ileum on a visual scale of 1 to 10. The patients were also asked to score the pain after receiving hyoscine butyl bromide injection on a score of 1 to 10.RESULTS:Terminal ileoscopy could be performed in 188 patients. The mean (SD) visual analogue score for the ease of intubation of the cecum was 7.4 (0.65) in the injection group and 5.9 (0.8) in the placebo group (P<0.001). The mean (SD) length of ileum visualized in the injection group was 14.4 (3.3) cm and 10.4 (2.7) cm in the placebo group (P<0.001). The mean (SD) visual analogue score for ease of visualization of the terminal ileum was 7.5 (0.69) in the injection group and 5.9 (0.7) in the placebo group (P<0.001). The pain score experienced by the patients was 6.5 (0.7) in the injection group and 6.7 (0.69) in the placebo group (P<0.008). Although the pulse rate increased significantly in patients receiving the drug,no statistically significant difference was noted in the oxygen saturation between the two groups either before or after administration of the drug. No complications were observed in either of the groups.CONCLUSION:Hyoscine butyl bromide injection is a useful adjunct in helping the intubation and visualizationof terminal ileum during colonoscopy.

  2. A sensitive and specific liquid chromatography/tandem mass spectrometry method for determination of pinaverium bromide in human plasma: application to a pharmacokinetic study in healthy volunteers.

    Science.gov (United States)

    Ren, Jin-Min; Zhao, Xi; Wang, Chuan-Ping; Sun, Qian; Yin, Li-Xin; Zhang, Zhi-Qing

    2011-12-01

    A sensitive and specific method using liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) for the determination of pinaverium bromide in human plasma was developed and validated. Pinaverium bromide and an internal standard (paclitaxel) were isolated from plasma samples by precipitating plasma, and determined by LC-MS/MS in multiple-reaction monitoring mode. The main metabolite of pinaverium bromide and endogenous substances in plasma did not show any interference. The calibration curve was linear over the plasma concentration range of 10.0-10000.0 pg/mL with a correlation coefficient of 0.9979. The relative standard derivations intra- and inter-day at 30.0, 300.0 and 8000.0 pg/mL in plasma were less than 15%. The absolute recoveries of pinaverium bromide and the internal standard were 99.7-111.7 and 106.2%, respectively. The lower limit of quantitation was 10 pg/mL. The analytical method was successfully applied to study the pharmacokinetics of pinaverium bromide tablets in healthy Chinese volunteers. PMID:21308709

  3. Recent actions taken on methyl bromide under the Montreal Protocol: Their potential economic implications on international trade

    International Nuclear Information System (INIS)

    Methyl bromide (MB) produced and used by man is a versatile, highly effective, fastacting fumigant employed in a number of important ways to kill organisms destructive to plants. A wide spectrum of commodities is treated with MB. The compound is unique in that it provides a wide range of pest control, may be applied to a broad spectrum of both food and non-food commodities, can be used for fumigation of large and small quantities of materials, and, when applied properly, leaves no residues of toxicological significance. Recently, this compound has come under scientific scrutiny and has been identified as a potentially potent ozone depleting chemical. As a result, countries operating under the Montreal Protocol will be restricting its use, and, in some cases, eliminating its use altogether. To date there are no alternative chemical fumigants to replace methyl bromide. Non-chemical treatments such as irradiation, hot and cold treatments, modified atmosphere, etc., are the most promising. The paper focuses on the magnitude of the economic consequences on international trade and the necessity to have available alternative treatments that are highly effective, fast-acting, and practical. 8 refs, 12 tabs

  4. Linear optical properties and their bond length dependence of yttrium bromide from ab initio and density functional theory calculations

    Energy Technology Data Exchange (ETDEWEB)

    Alipour, Mojtaba, E-mail: malipour@shirazu.ac.ir [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Mohajeri, Afshan, E-mail: amohajeri@shirazu.ac.ir [Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of)

    2011-08-25

    Graphical abstract: The electronic properties such as the static dipole polarizability, anisotropy of the polarizability, and dipole moment of yttrium bromide, YBr (X{sup 1}{Sigma}) have been theoretically studied. Highlights: {yields} Conventional ab initio and density functional theory methods were employed to study linear optical properties of YBr molecule. {yields} Properties derivatives and their level of theory dependence were studied. {yields} Electron correlation effects and rovibrational corrections have also been discussed. - Abstract: We have employed conventional ab initio and density functional theory methods to study the electronic properties such as the mean static dipole polarizability, {alpha}-bar, anisotropy of the polarizability, {Delta}{alpha}, and dipole moment, {mu}, of yttrium bromide. The bond length dependence of properties is determined at different levels of theory and appropriate expansions around experimental internuclear distance have been presented. Moreover, the first and second geometrical derivatives for each property are quantified and their level of theory dependence has been analyzed. To study the effect of molecular rotation and vibration on the electronic properties, the rovibrational corrections have also been carried out. It is found that these corrections are less pronounced for considered properties of YBr. In all calculations, the electron correlation effects have been considered and discussed. The obtained results show that the electron correlation is more significant in the calculation of the mean and the anisotropy of dipole polarizability.

  5. Photoinduced Dissociation Of N-alkyl Bromides On Gallium Arsenide(110) And Gallium Arsenide(100) Electron And Fragment Dynamics

    CERN Document Server

    Khan, K A

    1999-01-01

    In this study we investigate the UV-initiated electron transfer and dissociation fragment dynamics of selected n-alkyl bromides physisorbed on single crystals of GaAs. By systematically varying different chemical and structural parameters of the adsorbate/substrate system we explore a number of fundamental questions regarding the basic physics and chemistry of photochemical processes on surfaces. Monolayers of methyl, ethyl and propyl bromide were deposited on the (110), Ga-terminated (100) and As- terminated (100) surfaces of GaAs without thermal decomposition at 80 K. Substrate-mediated electron transfer to the molecule, induced by exposure to UV light at 193, 248 and 351 nm, causes C-Br bond cleavage. The electron transfer dynamics of this mechanism are examined as a function of wavelength and molecular complexity of the adsorbate to better understand the flow of energy and charge across the adsorbate/substrate interface. The photodynamics of the alkyl fragments are studied using mass-, energy- and angle-r...

  6. Study on the toxicity of sodium bromide to different fresh water organisms. [Scenedesmus pannonicus; Daphnia magna; Poecilia reticulata; Oryzias latipas

    Energy Technology Data Exchange (ETDEWEB)

    Canton, J.H.; Wester, P.W.; Mathijssen-Spiekman, E.A.

    1983-08-01

    The toxicity of sodium bromide for fresh water organisms was tested using algae (Scenedesmus pannonicus), crustaceans (Daphnia magna) and fish (Poecilia reticulata and Oryzias latipes). Depending on the species tested, the acute toxicity varied from 44 to 5800 mg Br-/litre (EC50 values) and the No Observed Effect Concentrations (NOEC values) in the long-term tests varied from 7.8 to 250 mg Br-/litre. Bromide ion markedly impaired reproduction in both crustaceans and fish. Histologically no effects were observed in the long-term test with Oryzias, but in the reproduction test with Poecilia, hyperplasia of the thyroid, atrophy and degeneration of the musculature and regressive changes in the female reproductive tract were observed. As a criterion of water quality, 1 mg Br-/litre has been proposed, on the basis of reproductive performance in the Poecilia test. The concentrations found in surface water frequently exceed this value and sometimes reach levels at which acute effects on water organisms can be expected.

  7. The Efficacy and Safety of Topical Rocuronium Bromide to Induce Bilateral Mydriasis in Hispaniolan Amazon Parrots ( Amazona ventralis ).

    Science.gov (United States)

    Baine, Katherine; Hendrix, Diane V H; Kuhn, Sonia E; Souza, Marcy J; Jones, Michael P

    2016-03-01

    The efficacy and safety of topically applied rocuronium in Hispaniolan Amazon parrots ( Amazona ventralis ) was assessed in a group of 10 adult birds. A complete ophthalmic examination (including Schirmer tear test, ocular reflexes, applanation tonometry, fluorescein staining, and slit-lamp biomicroscopy) was performed, and rocuronium bromide (0.15 mg in both eyes) was administered. Pupillary light reflex (PLR) and pupillary diameter were recorded in a darkened room at the following time points: 0, 10, 20, 30, 40, 50, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 300, and 360 minutes, and 24 hours. Fluorescein staining in both eyes was performed at 24 hours. By 10 minutes, PLR was absent in all birds (at 5 minutes, 8 birds; at 10 minutes, remaining 2 birds). Pupil diameter differed significantly from baseline at all time points. Additionally, PLR was decreased in 7/10 birds at 360 minutes and normal in all birds at 24 hours. Superficial corneal ulceration was observed at 24 hours in the left eye of 2/10 of the birds after fluorescein stain application. This study demonstrated that rocuronium bromide was an effective mydriatic agent in Hispaniolan Amazon parrots with rapid onset and prolonged duration of action. PMID:27088739

  8. The Efficacy and Safety of Topical Rocuronium Bromide to Induce Bilateral Mydriasis in Hispaniolan Amazon Parrots ( Amazona ventralis ).

    Science.gov (United States)

    Baine, Katherine; Hendrix, Diane V H; Kuhn, Sonia E; Souza, Marcy J; Jones, Michael P

    2016-03-01

    The efficacy and safety of topically applied rocuronium in Hispaniolan Amazon parrots ( Amazona ventralis ) was assessed in a group of 10 adult birds. A complete ophthalmic examination (including Schirmer tear test, ocular reflexes, applanation tonometry, fluorescein staining, and slit-lamp biomicroscopy) was performed, and rocuronium bromide (0.15 mg in both eyes) was administered. Pupillary light reflex (PLR) and pupillary diameter were recorded in a darkened room at the following time points: 0, 10, 20, 30, 40, 50, 60, 80, 100, 120, 140, 160, 180, 200, 220, 240, 300, and 360 minutes, and 24 hours. Fluorescein staining in both eyes was performed at 24 hours. By 10 minutes, PLR was absent in all birds (at 5 minutes, 8 birds; at 10 minutes, remaining 2 birds). Pupil diameter differed significantly from baseline at all time points. Additionally, PLR was decreased in 7/10 birds at 360 minutes and normal in all birds at 24 hours. Superficial corneal ulceration was observed at 24 hours in the left eye of 2/10 of the birds after fluorescein stain application. This study demonstrated that rocuronium bromide was an effective mydriatic agent in Hispaniolan Amazon parrots with rapid onset and prolonged duration of action.

  9. High-performance liquid chromatographic assay for the simultaneous determination of ipratropium bromide, fenoterol, salbutamol and terbutaline in nebulizer solution.

    Science.gov (United States)

    Jacobson, G A; Peterson, G M

    1994-06-01

    A reversed-phase ion-pair high-performance liquid chromatography assay was developed for the simultaneous determination of ipratropium bromide, fenoterol hydrobromide, salbutamol sulphate and terbutaline sulphate in nebulizer solution. Chromatographic separation was achieved with a Nova-Pak C18 4 microns 10 cm x 8 mm i.d. Radial-pak cartridge inside a Waters RCM 8 x 10 compression module using ternary gradient analysis. Detection was performed using UV detection at 220 nm. The standard curves were linear over the following ranges: ipratropium bromide 20.8-250.0 micrograms ml-1, fenoterol hydrobromide 27.8-500.0 micrograms ml-1, salbutamol sulphate 34.7-2500.0 micrograms ml-1 and terbutaline sulphate 69.5-2500 micrograms ml-1. Inter-day and intra-day relative standard deviations for each compound ranged from 4.5-5.2% and 3.5-3.9%, respectively. The assay procedure was developed to allow the accurate determination of constituents in various combinations of nebulizer solution, as well as for stability indicating purposes. This provides a convenient means of testing long-term compatibility and stability following the post-manufacture mixing of commonly used nebulized preparations. PMID:7918785

  10. Interaction between dodecyl oxypropyl β-hydroxyltrimethylammonium bromide and Xanthan: MesoDyn simulation and binding isotherm measurements

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    MesoDyn density functional simulation method is used to study the interactions between dodecyl oxypropyl β-hydroxyltrimethylammonium bromide (C12NBr) and Xanthan (XC). The micro dynamic process of aggregate formation and the aggregate morphology are reported. Interaction between XC and nonyphenyloxypropylβ-hydroxyltrimethylammonium bromide (C9phNBr) is compared with that between XC and C12NBr. Simulation results show that the aggregate morphology of XC/C12NBr and XC/C9phNBr is of rod-like shape with helix characteristic. The binding of C9phNBr to XC is more difficult than that of C12NBr to XC. In addition, three stages for the dynamic evolution of surfactant binding to XC are observed. The simulation results agree with binding isotherms of C9phNBr (C12NBr) to XC obtained via the potentiometric titration method, which shows a typical cooperative binding between C9phNBr (C12NBr) and XC.

  11. Chlorination of bromide-containing waters: Enhanced bromate formation in the presence ofsynthetic metal oxides and deposits formed indrinking water distribution systems

    KAUST Repository

    Liu, Chao

    2013-09-01

    Bromate formation from the reaction between chlorine and bromide in homogeneous solution is a slow process. The present study investigated metal oxides enhanced bromate formation during chlorination of bromide-containing waters. Selected metal oxides enhanced the decay of hypobromous acid (HOBr), a requisite intermediate during the oxidation of bromide to bromate, via (i) disproportionation to bromate in the presence of nickel oxide (NiO) and cupric oxide (CuO), (ii) oxidation of a metal to a higher valence state in the presence of cuprous oxide (Cu2O) and (iii) oxygen formation by NiO and CuO. Goethite (α-FeOOH) did not enhance either of these pathways. Non-charged species of metal oxides seem to be responsible for the catalytic disproportionation which shows its highest rate in the pH range near the pKa of HOBr. Due to the ability to catalyze HOBr disproportionation, bromate was formed during chlorination of bromide-containing waters in the presence of CuO and NiO, whereas no bromate was detected in the presence of Cu2O and α-FeOOH for analogous conditions. The inhibition ability of coexisting anions on bromate formation at pH 8.6 follows the sequence of phosphate>>sulfate>bicarbonate/carbonate. A black deposit in a water pipe harvested from a drinking water distribution system exerted significant residual oxidant decay and bromate formation during chlorination of bromide-containing waters. Energy dispersive spectroscopy (EDS) analyses showed that the black deposit contained copper (14%, atomic percentage) and nickel (1.8%, atomic percentage). Cupric oxide was further confirmed by X-ray diffraction (XRD). These results indicate that bromate formation may be of concern during chlorination of bromide-containing waters in distribution systems containing CuO and/or NiO. © 2013 Elsevier Ltd.

  12. Development of a miniature dielectric barrier discharge–optical emission spectrometric system for bromide and bromate screening in environmental water samples

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Dielectric barrier discharge (DBD) is for the first time used as a radiation source for the excitation of bromine and its emission. •A DBD–optical emission spectrometric (OES) system was developed for the detection of bromide and bromate. •The DBD–OES system has been demonstrated by screening trace bromide and bromate in a series of environmental water samples. -- Abstract: Dielectric barrier discharge (DBD) at atmospheric pressure provides an efficient radiation source for the excitation of bromine and it is used for the first time for optical emission spectrometric (OES) detection of bromide and bromate. A portable DBD–OES system is developed for screening potential pollution from bromide and bromate in environmental waters. Bromide is on-line oxidized to bromine for in-situ generation of volatile bromine. Meanwhile, a helium stream carries bromine into the DBD micro-plasma for its excitation at a discharging voltage of 3.7 kV and optical emission spectrometric detection with a QE65000 charge-coupled device (CCD) spectrometer in the near-infrared spectral region. Similarly, the quantification of bromate is performed by its pre-reduction into bromide and then oxidized to bromine. The spectral characteristics and configuration of the DBD micro-plasma excitation source in addition to the oxidation vapor generation of bromine have been thoroughly investigated. With a sampling volume of 1 mL, a linear range of 0.05–10.0 mg L−1 is obtained with a detection limit of 0.014 mg L−1 by measuring the emission at 827 nm. A precision of 2.3% is achieved at 3 mg L−1 bromide. The system is validated by bromine detection in certified reference material of laver (GBW10023) at mg L−1 level, giving rise to satisfactory agreement. In addition, it is further demonstrated by screening trace bromide and bromate as well as spiking recoveries in a series of environmental water samples

  13. Preparation of Mesoporous Molecular Sieves Al-MSU-S Using Ionic Liquids as Template

    Institute of Scientific and Technical Information of China (English)

    YU Xin-Yu; LIU Cai-Hua; YANG Jian-Guo; WU Hai-Hong; WU Peng; HE Ming-Yuan

    2006-01-01

    Mesoporous molecular sieves Al-MSU-S has been prepared from the precursor of zeolite Y using ionic liquids l-hexadecane-3-methylimidazolium bromide (CMIMB) as a template in basic medium, which exhibited larger pore diameter, pore volume and surface area than that synthesized using cetyl trimethyl ammonium bromide (CTAB)template.

  14. Apparent and partial molar volumes of long-chain alkyldimethylbenzylammonium chlorides and bromides in aqueous solutions at T=15 deg. C and T=25 deg. C[Alkyldimethylbenzylammonium chlorides; Alkyldimethylbenzylammonium bromides; Micellization; Density; Apparent molar volumes

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Perez, A.; Ruso, J.M.; Nimo, J.; Rodriguez, J.R. E-mail: fmjulio@usc.es

    2003-12-01

    Density measurements of dodecyl- (C{sub 12}DBACl), tetradecyl- (C{sub 14}DBACl), hexadecyldimethylbenzylammonium chloride (C{sub 16}DBACl) and of decyl- (C{sub 10}DBABr) and dodecyldimethylbenzylammonium bromide (C{sub 12}DBABr) in aqueous solutions at T=15 deg. C and T=25 deg. C have been carried out. From these results, apparent and partial molar volumes were calculated. Positive deviations from the Debye-Hueckel limiting law provide evidence for limited association at concentrations below the critical micelle concentration. The change of the apparent molar volume upon micellization was calculated. The relevant parameters have been presented in function of the alkyl chain length. Apparent molar volumes of the present compounds in the micellar phase, V{sub phi}{sup m}, and the change upon micellization, {delta}V{sub phi}{sup m}, have been discussed in terms of temperature and type of counterion.

  15. Bromide and other ions in the snow, firn air, and atmospheric boundary layer at Summit during GSHOX

    Directory of Open Access Journals (Sweden)

    J. E. Dibb

    2010-10-01

    Full Text Available Measurements of gas phase soluble bromide in the boundary layer and in firn air, and Br in aerosol and snow, were made at Summit, Greenland (72.5° N, 38.4° W, 3200 m a.s.l. as part of a larger investigation into the influence of Br chemistry on HOx cycling. The soluble bromide measurements confirm that photochemical activation of Br in the snow causes release of active Br to the overlying air despite trace concentrations of Br in the snow (means 15 and 8 nmol Br kg−1 of snow in 2007 and 2008, respectively. Mixing ratios of soluble bromide above the snow were also found to be very small (mean <1 ppt both years, with maxima of 3 and 4 ppt in 2007 and 2008, respectively, but these levels clearly oxidize and deposit long-lived gaseous elemental mercury and may perturb HOx partitioning. Concentrations of Br in surface snow tended to increase/decrease in parallel with the specific activities of the aerosol-associated radionuclides 7Be and 210Pb. Earlier work has shown that ventilation of the boundary layer causes simultaneous increases in 7Be and 210Pb at Summit, suggesting there is a pool of Br in the free troposphere above Summit in summer time. Speciation and the source of this free tropospheric Br are not well constrained, but we suggest it may be linked to extensive regions of active Br chemistry in the Arctic basin which are known to cause ozone and mercury depletion events shortly after polar sunrise. If this hypothesis is correct, it implies persistence of the free troposphere Br for several months after peak Br activation in March/April. Alternatively, there may be a ubiquitous pool of Br in the free troposphere, sustained by currently unknown sources and processes.

  16. Bromide and other ions in the snow, firn air, and atmospheric boundary layer at Summit during GSHOX

    Directory of Open Access Journals (Sweden)

    J. E. Dibb

    2010-05-01

    Full Text Available Measurements of gas phase soluble bromide in the boundary layer and in firn air, and Br in aerosol and snow, were made at Summit, Greenland (72.5° N, 38.4° W, 3200 m a.s.l. as part of a larger investigation into the influence of Br chemistry on HOx cycling. The soluble bromide measurements confirm that photochemical activation of Br in the snow causes release of active Br to the overlying air despite trace concentrations of Br in the snow (means 15 and 8 nmol Br kg−1 of snow in 2007 and 2008, respectively. Mixing ratios of soluble bromide above the snow were also found to be very small (mean <1 ppt both years, with maxima of 3 and 4 ppt in 2007 and 2008, respectively, but these levels clearly oxidize and deposit long-lived gaseous elemental mercury and may perturb HOx partitioning. Concentrations of Br in surface snow tended to increase/decrease in parallel with the specific activities of the aerosol-associated radionuclides 7Be and 210Pb. Earlier work has shown that ventilation of the boundary layer causes simultaneous increases in 7Be and 210Pb at Summit, suggesting there is a pool of Br in the free troposphere above Summit in summer time. Speciation and the source of this free tropospheric Br are not well constrained, but we suggest it may be linked to extensive regions of active Br chemistry in the Arctic basin which are known to cause ozone and mercury depletion events shortly after polar sunrise. If this hypothesis is correct, it implies persistence of the free troposphere Br for several months after peak Br activation in March/April. Alternatively, there may be a~ubiquitous pool of Br in the free troposphere, sustained by currently unknown sources and processes.

  17. A COMPARATIVE CLINICAL EVALUATION OF INTUBATING CONDITIONS AND HAEMODYNAMIC EFFECTS AFTER ADMINISTRATION OF SUCCINYL CHOLINE & ROCURONIUM BROMIDE

    Directory of Open Access Journals (Sweden)

    Abhishek

    2015-04-01

    Full Text Available BACKGROUND: Rapid and safe endotracheal intubation is of paramount importance in practice of general anesthesia . Succinylcholine chloride , a depolarizing muscl e relaxant due to its quick onset of action and excellent intubating conditions has remained a muscle relaxant of choice . Rocuronium was proved to be safe alternative to Succinylcholine for endotracheal intubation . AIMS : Study was conducted to evaluate & c ompare the onset time , clinical duration and intubating condition of Succinylcholine and Rocuronium Bromide and Haemodynamic changes caused by these agents . METHODS & MATERIALS : 80 patients were randomly divided into two groups . Group - 1 , Succinylcholine ( 1 . 5mg/kg and group - 2 Rocuronium Bromide ( 0 . 6mg/kg . After 60 sec of administration of muscle relaxant , intubating conditions were judged according to scoring system by Cooper et al . 1 Onset time and duration of action was noted . Hemodynamic parameters ( H eart rate , Systolic Blood Pressure , Diastolic Blood Pressure , Mean Atrial pressure and SPO 2 were monitored before intubation , during intubation and just after intubation at 1 , 2 and 5 minutes . RESULTS : The mean onset time and duration of action was signi ficantly longer for Rocuronium ( 95 . 15±9 . 47 seconds than Succinylcholine ( 59 . 80±14 . 30 seconds and Rocuronium ( 42 . 60±13 . 15 minutes than Succinylcholine ( 5 . 10±2 . 35 minutes . Intubating conditions was excellent in 35 ( 87% and good in 5 ( 12 . 5% patients in su ccinylcholine whereas , in Rocuronium produced excellent intubation in only 23 ( 57 . 5% patients and good intubation in 14 ( 35% patients . The heart rate increased significantly after induction ( maximum at 1 minute with both Rocuronium ( 98 . 75±15 . 53 and Succi nylcholine ( 112 . 75±15 . 89 . But it gradually declined towards normal and change in heart rate with either drug was not significant at 5 minutes . The mean blood pressure increased significantly after induction

  18. Evaluation of the combination of dimethyl disulfide and dazomet as an efficient methyl bromide alternative for cucumber production in China.

    Science.gov (United States)

    Mao, Liangang; Yan, Dongdong; Wang, Qiuxia; Li, Yuan; Ouyang, Canbin; Liu, Pengfei; Shen, Jin; Guo, Meixia; Cao, Aocheng

    2014-05-28

    The combination of dimethyl disulfide (DMDS) and dazomet (DZ) is a potential alternative to methyl bromide (MB) for soil disinfestation. The efficacy of DMDS plus DZ in controlling key soilborne pests was evaluated in a laboratory study and in two commercial cucumber greenhouses. Laboratory studies found that all of the combinations had positive synergistic effects on root-knot nematodes, two key soilborne fungi, and two major weed seeds. Greenhouse trials revealed that the combination of DMDS and DZ (30 + 25 g m(-2)) successfully suppressed Meloidogyne spp. root galling, sharply reduced the colony-forming units of Fusarium spp. and Phytophthora spp. on media, maintained high cucumber yields, and was not significantly different from MB or DMDS alone, but better than DZ alone. All of the chemical treatments provided significantly better results than the nontreated control. The results indicate that the combination of DMDS and DZ is an efficient MB alternative for cucumber production. PMID:24820184

  19. CO2 capture from binary mixture via forming hydrate with the help of tetra-n-butyl ammonium bromide

    Institute of Scientific and Technical Information of China (English)

    Shifeng Li; Shuanshi Fan; Jingqu Wang; Xuemei Lang; Deqing Liang

    2009-01-01

    Hydrate formation rate and separation effect on the capture of CO2 from binary mixture v/a forming hydrate with 5 wt% tetra-n-butyl ammonium bromide (TBAB) solution were studied.The results showed that the induction time was 5 min,and the hydrate formation process pressure of 7.30 MPa.The CO2 recovery was about 45% in the feed pressure range from 4.30 to 7.30 MPa.Under the feed pressure of 4.30 MPa,the maximum separation factor and CO2 concentration in hydrate phase were 7.3 and 38.2 tool%,respectively.The results demonstrated that TBAB accelerated hydrate formation and enriched CO2 in hydrate phase under the gentle condition.

  20. A comparison of didodecyldimethylammonium bromide adsorbed at mica/water and silica/water interfaces using neutron reflection.

    Science.gov (United States)

    Griffin, Lucy R; Browning, Kathryn L; Truscott, Chris L; Clifton, Luke A; Webster, John; Clarke, Stuart M

    2016-09-15

    The layer structure of the dichain alkyl ammonium surfactant, didodecyldimethylammonium bromide (DDAB), adsorbed from water on to silica and mica surfaces has been determined using neutron reflection. Although sometimes considered interchangeable surfaces for study, we present evidence of significant differences in the adsorbed layer structure below the critical micelle concentration. A complete DDAB bilayer was assembled at the water/mica interface at concentrations below the critical micelle concentration (CMC). In contrast it is not until the CMC was reached that the complete bilayer structure formed on the oxidised silicon crystal. Removal of the complete bilayer on both surfaces was attempted by both washing and ion exchange yet the adsorbed structure proved tenacious. PMID:27318715

  1. Unilateral pupillary mydriasis from nebulized ipratropium bromide: A false sign of brain herniation in the intensive care unit

    Directory of Open Access Journals (Sweden)

    Priyanka Chaudhry

    2014-01-01

    Full Text Available Although there are many causes of anisocoria in the intensive care setting, the development of unilateral mydriasis in patients with intracranial hemorrhage or tumor is a neurological emergency, as it may herald the onset of uncal herniation. We describe two patients with a hemiparesis from neurosurgical disorder who subsequently developed a fixed and dilated pupil. The pupillary abnormality was caused by nebulized ipratropium bromide in both cases, and resolved when the medication was discontinued. Nebulized ipratropium may leak from the mask into ipsilateral eye and cause mydriasis in patients with facial weakness. This benign cause of anisocoria in the intensive care setting is distinguished from uncal herniation by the laterality of neurologic findings, and lack of mental status change, ptosis, and extraocular movement impairment.

  2. Spectrophotometric Method for Estimation of Tamsulosin Hydrochloride in Pharmaceutical Dosage Form Using Bromate-Bromide and Methyl Orange Reagent

    Directory of Open Access Journals (Sweden)

    Bharatkumar Ganeshbhai Chaudhari

    2012-09-01

    Full Text Available A simple, rapid, accurate and precise assay procedure based on Spectrophotometric method has been developed for the estimation of Tamsulosin hydrochloride in Pharmaceutical formulation. The method was based on the bromination of Tamsulosin hydrochloride with a known excess amount of Bromate-bromide mixture in acidic medium followed by the determination of surplus bromine by reacting with dye methyl orange and measuring the absorbance at 513 nm. Validation was carried out in compliance with International Conference on Harmonization guidelines. Linear regression analysis of method showed good linearity with the correlation co-efficient (r of 0.9978 with respect to absorbance in the concentration range of 2-12 μg/mL and the mean recovery for Tamsulosin hydrochloride was 99.65% ± 0.47 . The proposed method can be successfully applied for the analysis of tablet formulations.

  3. Characterization of Jamaican agro-industrial wastes. Part II, fatty acid profiling using HPLC: precolumn derivatization with phenacyl bromide.

    Science.gov (United States)

    Bailey-Shaw, Y A; Golden, K D; Pearson, A G M; Porter, R B R

    2012-09-01

    This paper describes the determination of fatty acid composition of coffee, citrus and rum distillery wastes using reversed-phase high-performance liquid chromatography (RP-HPLC). Lipid extracts of the waste samples are derivatized with phenacyl bromide and their phenacyl esters are separated on a C8 reversed-phase column by using continuous gradient elution with water and acetonitrile. The presence of saturated and unsaturated fatty acids in quantifiable amounts in the examined wastes, as well as the high percentage recoveries, are clear indications that these wastes have potential value as inexpensive sources of lipids. The HPLC procedures described here could be adopted for further analysis of materials of this nature. PMID:22595260

  4. Physicochemistry of hexadecylammonium bromide and its methyl and ethanolic head group analogues in buffered aqueous and gelatin solution

    Indian Academy of Sciences (India)

    Debolina Mitra; Satya P Moul

    2010-05-01

    In this work, the interfacial and bulk behaviour of the amphiphiles hexadecylammonium bromide and its methyl and ethanolic head group analogues in buffered aqueous and gelatin solution has been examined. The analogues are of two categories: the methyl and the combined methyl and ethanolic head group representatives are considered as Group A compounds, and all non-methyl but ethanolic head group species are taken as Group B compounds. Different physical techniques have been employed to ascertain the amphiphilic behaviour in solution. The self-aggregation of these surfactants at different pH has been studied along with pH dependent interfacial activity of gelatin. The interaction of the two categories of the surfactants with gelatin at different pH has been investigated. A scheme for this interaction at various stages of the process has been proposed. The influence of the surfactant head groups on the interaction process has been assessed.

  5. SiO{sub x} monolayer overcoating effect on the TiO{sub 2} photocatalytic oxidation of cetylpyridinium bromide

    Energy Technology Data Exchange (ETDEWEB)

    Tada, Hiroaki; Kubo, Yasuyuki; Akazawa, Manabu; Ito, Seishiro

    2000-01-15

    The effect of SiO{sub x} monolayer coverage on the rate of TiO{sub 2} photocatalytic oxidation of cetylpyridinium bromide (CPB) in aqueous solutions has been studied. The rate of CPB removal from the solution (5 < pH < 7) increases with the surface modification at concentrations below 4.5 x 10{sup {minus}4} M and its promoting effect is enhanced with decreasing concentration. A modified Langmuir-Hinshelwood model, where the rate of surface reaction is assumed to be proportional to the coverage of CPB at the photostationary state is proposed for dilute reaction systems. As a result of the kinetic analyses, the acceleration of the reaction with the SiO{sub x} monolayer coverage can be attributed to the increase in the rate of adsorption due to the electrostatic attraction of cetylpyridinium ion. The suppression of Br{sup {minus}} adsorption is also suggested as a minor contribution.

  6. An Efficient and General Method for Formylation of Aryl Bromides with CO2 and Poly(methylhydrosiloxane).

    Science.gov (United States)

    Yu, Bo; Yang, Zhenzhen; Zhao, Yanfei; Hao, Leiduan; Zhang, Hongye; Gao, Xiang; Han, Buxing; Liu, Zhimin

    2016-01-18

    The formylation of aryl halides with CO2 to generate aryl aldehydes is challenging. Herein, we report a novel synthesis of aryl aldehydes by formylation of aryl bromides with CO2 and a waste silane, poly(methylhydrosiloxane) (PMHS). It has been discovered that a simple combination of 1,3-bis(diphenyphosphino)propane (DPPP)-chelated Pd catalyst, Pd(DPPP)Cl2 , with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is able to effectively catalyze the reaction, leading to aryl aldehydes in moderate to excellent yields, and without any by-products in most cases. Moreover, this route could be extended to the formylation of aryl iodides with high efficiency. This approach is simple, less costly, and environmentally friendly, and also widens the applications of CO2 to form value-added chemicals by the construction of new C-C bonds.

  7. Purification of Zinc Bromide Solution used as shield in hot cells windows for handling of highly radioactive sources

    International Nuclear Information System (INIS)

    After some time of use zinc bromide solutions get a yellowish colour and form brownish precipitate, sticking on the walls of the windows that seem to be dirty caused by the effect of the solution penetrating into the packing and epoxy layer of the windows; all these effects cause the corrosive attack over the metallic parts of the window's frame and the same time the clarity and visibility inside the windows become defective. The aim and purpose of the present work was to set up a method intended for the recovery of all the solutions avoiding the use of a new one, the deviation of the original properties was corrected, and the recovered solutions could be used immediately; the experiments were done in the laboratory using a pyrex glass vacuum evaporator flash type, and the results were successful. The sample volume was 1500 1, and the time employed to 100 days. (Author)

  8. A kinetic study of the thermal degradation of cetyltrimethylammonium bromide inside the mesoporous SBA-3 molecular sieve

    Directory of Open Access Journals (Sweden)

    DJORDJE STOJAKOVIC

    2007-12-01

    Full Text Available The thermal degradation of cetyltrimethylammonium bromide (CTMAB inside the mesoporous SBA-3 was studied under non-isothermal conditions. There are two distinct and complex kinetic processes which partly overlap, each consisting of one dominant and three minor individual processes. The two dominant processes can be described by the Sestak–Berggren model. The main decomposition step (the first dominant process involves the overcoming of weak interactions between CTMAB and the silica network and proceeds with a lower Ea value (116±2 kJ mol‑1 than the second dominant process (153±5 kJ mol-1, which can be explained by the size reduction of the pore openings due to the contraction of the SBA-3 unit cell caused by the removal of CTMAB.

  9. Polarization versus Temperature in Pyridinium Ionic Liquids

    DEFF Research Database (Denmark)

    Chaban, V. V.; Prezhdo, O. V.

    2014-01-01

    Electronic polarization and charge transfer effects play a crucial role in thermodynamic, structural, and transport properties of room-temperature ionic liquids (RTILs). These nonadditive interactions constitute a useful tool for tuning physical chemical behavior of RTILs. Polarization and charge...... interactions changes negligibly between 300 and 900 K, while the average dipole moment increases due to thermal fluctuations of geometries. Our results contribute to the fundamental understanding of electronic effects in the condensed phase of ionic systems and foster progress in physical chemistry...

  10. Long-term efficacy and safety of otilonium bromide in the management of irritable bowel syndrome: a literature review

    Directory of Open Access Journals (Sweden)

    Triantafillidis JK

    2014-04-01

    Full Text Available John K Triantafillidis, George Malgarinos Inflammatory Bowel Disease Unit, IASO General Hospital, Athens, Greece Abstract: Irritable bowel syndrome (IBS is a very common functional gastrointestinal disorder characterized by abdominal pain or discomfort and altered bowel habits. The disease affects a large part of the world population. The clinical course is mostly characterized by a cyclic recurrence of symptoms. Therefore, IBS patients should receive, as an initial therapeutic approach, a short course of treatment, and long-term treatment should be reserved for those patients with recurrent symptoms. The available clinical trials show that significant improvement of the symptoms over placebo could be achieved with various drugs, although this improvement is frequently time dependent and with high relapse rates after the cessation of the treatment. In a proportion of patients, clinically obvious relapse could appear long after stopping the treatment. Some of the available pharmacologic agents, including otilonium bromide (OB, are able to significantly prolong the time to the appearance of relapse, compared with placebo. As a consequence, some authors suggest that a cyclic treatment could be of benefit. Antispasmodic drugs have been used for many years in an effort to control the symptoms of IBS. OB is a poorly absorbed spasmolytic drug, exerting significantly greater control of the symptoms of IBS compared with placebo. Recent data suggest that the drug could effectively be used for the long-term management of patients with IBS. The aim of this review is to provide the reader with an evidence-based overview of the efficacy and tolerability of OB in the long-term management of IBS patients, based on the results of the clinical trials published so far. Keywords: irritable bowel syndrome, IBS, treatment, otilonium bromide

  11. Transport of bromide and pesticides through an undisturbed soil column: a modeling study with global optimization analysis.

    Science.gov (United States)

    Dusek, Jaromir; Dohnal, Michal; Snehota, Michal; Sobotkova, Martina; Ray, Chittaranjan; Vogel, Tomas

    2015-01-01

    The fate of pesticides in tropical soils is still not understood as well as it is for soils in temperate regions. In this study, 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. The numerical model is based on Richards' equation for solving water flow, and the advection-dispersion equation for solving solute transport. Data from a laboratory column leaching experiment were used in the uncertainty analysis using a global optimization methodology to evaluate the model's sensitivity to transport parameters. All pesticides were found to be relatively mobile (sorption distribution coefficients lower than 2 cm(3) g(-1)). Experimental data indicated significant non-conservative behavior of bromide tracer. All pesticides, with the exception of imidacloprid, were found less persistent (degradation half-lives smaller than 45 days). 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. Uncertainty analysis using a physically-based Monte Carlo modeling of pesticide fate and transport provides useful information for the evaluation of chemical leaching in Hawaii soils. PMID:25703186

  12. Pharmacoeconomic evaluation of tiotropium bromide in the long-term treatment of chronic obstructive pulmonary disease (COPD) in Italy.

    Science.gov (United States)

    Zaniolo, O; Iannazzo, S; Pradelli, L; Miravitlles, M

    2012-02-01

    The randomized, double-blind trial UPLIFT(®) demonstrated in 5,993 patients with moderate to very severe COPD that 4 years of tiotropium bromide therapy were associated with improvements in lung function, exacerbations, quality of life, and mortality compared with placebo. The pharmacoeconomic evaluation was performed through a probabilistic, patient-level simulation Markov model. Routine COPD care (RC) was compared with the inclusion of tiotropium bromide on it. The analysis was conducted over a lifetime horizon, with 1 year cycles and a 3.5% annual discount rate. Patients were characterized by gender, age, height, smoking status, and forced expiratory volume in 1 s (FEV1). FEV1 time trend was modeled according to the annual decline recorded in UPLIFT®. Mortality derived from that of the general Italian population was adjusted by smoking status and FEV1. Health utilities derived from published Italian observational studies and were varied in time according to UPLIFT® data. Exacerbation rates were derived from a published Italian observational prospective study. The cost perspective was that of the Italian National Health Service. Healthcare resource consumption for RC and exacerbations derived from Italian observational studies were valued according to current price and tariffs. Simulated patients in the tiotropium arm gained an average (95% CI) 0.50 (-1.63 to 6.27) Life Years (LYs) and 0.42 (-0.25 to 3.05) Quality-Adjusted Life Years (QALYs). The incremental lifetime cost resulted €3,357 (-€10,669 to €29,820). The incremental cost-effectiveness ratio (ICER) was €6,698/LY and €7,916/QALY. In the cost-effectiveness acceptability curve (CEAC), tiotropium had a 90% probability of being cost-effective for a willingness to pay (WTP) threshold of € 10,000/QALY. PMID:21086017

  13. 1-Methyl-2-[(E-2,4,5-trimethoxystyryl]pyridinium iodideThis paper is dedicated to the late His Majesty King Chulalongkorn (King Rama V of Thailand for his numerous reforms to modernize the country on the occasion of Chulalongkorn Day (Piyamaharaj Day which fell on the 23rd October.

    Directory of Open Access Journals (Sweden)

    Hoong-Kun Fun

    2010-12-01

    Full Text Available In the title compound, C17H20NO3+·I−, the cation exists in the E configuration. The pyridinium and benzene rings are close to coplanar, with a dihedral angle of 7.43 (12° between them. The three methoxy groups of 2,4,5-trimethoxyphenyl are essentially coplanar with the benzene plane, with C—O—C—C torsion angles of 1.0 (3, −1.9 (3 and 3.6 (3°. A weak intramolecular C—H...O interaction generates an S(6 ring motif. In the crystal, the cations are stacked in columns in an antiparallel manner along the a axis through π–π interactions, with a centroid–centroid distance of 3.7714 (16 Å. The iodide anion is situated between the columns and linked to the cation by a weak C—H...I interaction.

  14. Rapid synthesis of an electron-deficient t-BuPHOX ligand: cross-coupling of aryl bromides with secondary phosphine oxides

    KAUST Repository

    McDougal, Nolan T.

    2010-10-01

    Herein an efficient and direct copper-catalyzed coupling of oxazoline-containing aryl bromides with electron-deficient secondary phosphine oxides is reported. The resulting tertiary phosphine oxides can be reduced to prepare a range of PHOX ligands. The presented strategy is a useful alternative to known methods for constructing PHOX derivatives.

  15. Practical synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides via conventional and decarboxylative copper-free Sonogashira coupling reactions

    Directory of Open Access Journals (Sweden)

    Andrea Caporale

    2014-02-01

    Full Text Available Two efficient protocols for the palladium-catalyzed synthesis of aryl-2-methyl-3-butyn-2-ols from aryl bromides in the absence of copper were developed. A simple catalytic system consisting of Pd(OAc2 and P(p-tol3 using DBU as the base and THF as the solvent was found to be highly effective for the coupling reaction of 2-methyl-3-butyn-2-ol (4 with a wide range of aryl bromides in good to excellent yields. Analogously, the synthesis of aryl-2-methyl-3-butyn-2-ols was performed also through the decarboxylative coupling reaction of 4-hydroxy-4-methyl-2-pentynoic acid with aryl bromides, using a catalyst containing Pd(OAc2 in combination with SPhos or XPhos in the presence of tetra-n-butylammonium fluoride (TBAF as the base and THF as the solvent. Therefore, new efficient approaches to the synthesis of terminal acetylenes from widely available aryl bromides rather than expensive iodides and using 4 or propiolic acid rather than TMS-acetylene as inexpensive alkyne sources are described.

  16. Copper-catalyzed tandem reaction of 2-bromobenzyl bromides with 1,3-dicarbonyl compounds leading to 4H-chromenes

    Institute of Scientific and Technical Information of China (English)

    Xin Ying Zhang; Liang Liang Fang; Nan Liu; Hua Yue Wu; Xue Sen Fan

    2012-01-01

    A Cu(I)-catalyzed one-pot tandem reaction of 2-bromobenzyl bromides with 1,3-dicarbonyl compounds leading to 4H-chromene derivatives has been developed.This new approach toward 4H-chromenes combines several reactions in one pot and builds molecular complexity from readily available starting materials.

  17. Synthesis and characterization of [BMIM]bromide using microwave-assisted organic synthesis method and its application for dissolution of palm empty fruit bunch

    International Nuclear Information System (INIS)

    The decrease of cellulose crystallinity index of palm empty fruit bunch is crucial for the next application of cellulose as raw material for various biofuel and its derivatives. The aim of this research is to decrease the cellulose crystallinity index of palm empty fruit bunch using 1-butyl-3-methylimidazoliumbromide or [BMIM] bromide which has been synthesized using Microwave-Assisted Organic Synthesis (MAOS) method. Conventional reaction method has also been carried out to synthesize [BMIM]bromide for comparison as well. The characterization of synthesized product using FTIR, 1H-NMR, 13C-NMR and LC-MS showed that these reactions have been carried out successfully. The results showed that MAOS method is up to 90% faster in producing [BMIM]bromide compare to the conventional method. The application of [BMIM]bromide for dissolution of palm empty fruit bunch showed that cellulose and lignin could be extracted using stirring process for 20 hours. The decrease of cellulose crystallinity index and its morphology changes were identified using FTIR and Scanning Electron Microscope

  18. Re-manufacture of cobalt-manganese-bromide as a liquid catalyst from spent catalyst containing cobalt generated from petrochemical processes via hydrometallurgy.

    Science.gov (United States)

    Joo, Sung-Ho; Shin, Dong Ju; Oh, Chang Hyun; Wang, Jei-Pil; Shin, Shun Myung

    2016-11-15

    Cobalt and manganese have been the subject of individual separation studies because their fields of application are different. However, this study shows that high-value products can be manufactured in the form of a cobalt-manganese-bromide (CMB) liquid catalyst by simultaneously recovering cobalt and manganese. Na-bis-(2,4,4-tri-methyl-pentyl)phosphinic acid was employed in order to manufacture the CMB liquid catalyst from the spent catalyst generated from petroleum chemistry processes. The pH-isotherm, degree of saponification of solvent and separation factor values were investigated. ΔpH50 and separation factor values show that Co and Mn can be separated from impurities such as Mg and Ca. Further, the extraction stages and organic/aqueous ratio isotherms were investigated using counter-current simulation extraction batch tests. To prepare CMB from a loaded organic phase obtained in a stripping study using hydrogen bromide, the Co and Mn were completely stripped and concentrated by a factor of 6 using a 2M hydrogen bromide solution. When compared with manufactured and commercial CMB, the CMB liquid catalyst could be produced by supplying a shortage of Mn in the form of manganese bromide. Finally, the method of manufacture of CMB was subjected to a real pilot plant test.

  19. Air conditioning using an air-cooled single effect lithium bromide absorption chiller: results of a trial conducted in Madrid in August 2005

    OpenAIRE

    Izquierdo, M.; Lizarte, R.; Marcos, J.D.; Gutiérrez, G.

    2008-01-01

    Air conditioning using an air-cooled single effect lithium bromide absorption chiller: results of a trial conducted in Madrid in August 2005 correspondence: Corresponding author. Tel.: + 34 91 871 32 48; fax: + 34 91 871 32 48. (Izquierdo, M.) (Izquierdo, M.) Instituto de Ciencias de la Construccion Eduardo Torroja (CSIC) c/Serrano Galvache 4 - 28033 Madrid--> - SPAIN (Izquierdo, M.) SPAIN (Izquierdo, M.)...

  20. Synthesis and characterization of [BMIM]bromide using microwave-assisted organic synthesis method and its application for dissolution of palm empty fruit bunch

    Energy Technology Data Exchange (ETDEWEB)

    Arianie, Lucy, E-mail: lucy205@yahoo.com [Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Tanjungpura, Jl. A.Yani, 73 Pontianak 78124 (Indonesia); Wahyuningrum, Deana, E-mail: deana@chem.itb.ac.id; Nurrachman, Zeily, E-mail: deana@chem.itb.ac.id; Natalia, Dessy, E-mail: deana@chem.itb.ac.id [Department of Chemistry, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Jl. Ganesha 10 Bandung 40132 (Indonesia)

    2014-03-24

    The decrease of cellulose crystallinity index of palm empty fruit bunch is crucial for the next application of cellulose as raw material for various biofuel and its derivatives. The aim of this research is to decrease the cellulose crystallinity index of palm empty fruit bunch using 1-butyl-3-methylimidazoliumbromide or [BMIM] bromide which has been synthesized using Microwave-Assisted Organic Synthesis (MAOS) method. Conventional reaction method has also been carried out to synthesize [BMIM]bromide for comparison as well. The characterization of synthesized product using FTIR, {sup 1}H-NMR, {sup 13}C-NMR and LC-MS showed that these reactions have been carried out successfully. The results showed that MAOS method is up to 90% faster in producing [BMIM]bromide compare to the conventional method. The application of [BMIM]bromide for dissolution of palm empty fruit bunch showed that cellulose and lignin could be extracted using stirring process for 20 hours. The decrease of cellulose crystallinity index and its morphology changes were identified using FTIR and Scanning Electron Microscope.

  1. Far-infrared laser action in vinyl chloride, vinyl bromide, and vinyl fluoride optically pumped by a CW N2O laser

    Science.gov (United States)

    Gastaud, C.; Redon, M.; Belland, P.; Fourrier, M.

    1984-06-01

    This paper reports the first use of a N2O laser for optically pumping vinyl halides, to obtain new cw submillimeter laser lines. Eighteen far-infrared (FIR) emissions have been observed in vinyl chloride, twenty five in vinyl bromide and thirty eight in vinyl flouride.

  2. Activated carbons from end-products of tree nut and tree fruit production as sorbents for removing methyl bromide in ventilation effluent from postharvest chamber fumigation

    Science.gov (United States)

    End-products of tree nuts and tree fruits grown in California, USA were evaluated for the ability to remove methyl bromide from the ventilation effluent of postharvest chamber fumigations. Activated carbon sorbents from walnut and almond shells as well as peach and prune pits were prepared using dif...

  3. Development of an activated carbon-based electrode for the capture and rapid electrolytic reductive debromination of methyl bromide from post-harvest fumigations

    Science.gov (United States)

    Due to concerns surrounding its ozone depletion potential, there is a need for technologies to capture and destroy methyl bromide (CH3Br) emissions from post-harvest fumigations applied to control agricultural pests. Previously we described a system in which CH3Br fumes vented from fumigation chambe...

  4. Synthesis and Catalytic Properties of Non-Cross-Linked and Cross-Linked Poly(alkylmethyldiallylammonium bromides) Having Decyl, Octyl, and Hexyl Side Chains

    NARCIS (Netherlands)

    Wang, G.J; Engberts, J.B.F.N.

    1995-01-01

    A family of non-cross-linked and cross-linked copolymers containing decyl, octyl, and hexyl groups as side chains ((CL)-CopolC1-10, (CL)-CopolC1-8, and (CL)-CopolC1-6, respectively) were synthesized by radical-initiated cyclocopolymerization of alkylmethyldiallylammonium bromide monomers without and

  5. Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide gemini surfactants as novel corrosion inhibitors for mild steel in formic acid

    Directory of Open Access Journals (Sweden)

    Mohammad Mobin

    2012-12-01

    Full Text Available Gemini surfactants, butanediyl 1,4-bis(dimethyl cetylammonium bromide, pentanediyl 1,5 - bis (dimethyl cetylammonium bromide and hexanediyl 1,6 - bis (dimethyl cetylammonium bromide from Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide series were synthesized in laboratory and were characterized by using Nuclear Magnetic Resonance (NMR spectroscopy. The surfactants were tested as corrosion inhibitors for mild steel in 20% formic acid. The influence of surfactants on mild steel corrosion inhibition was investigated by measuring the corrosion rate of mild steel in their absence and presence by weight loss measurements, solvent analysis of iron ions into the test solution and potentiodynamic polarization measurements. The surface morphology of the corroded steel samples in presence and absence of surfactants was evaluated by using Scanning Electron Microscopy (SEM. The synthesized gemini surfactants performed as excellent corrosion inhibitor, the inhibition efficiency (IE being in the range of 76.66-97.41%. The IE of surfactants is slightly affected by the spacer length. The IE increased with increase in surfactant concentration and temperature. The adsorption of gemini surfactants on the steel surface was found to obey Langmuir adsorption isotherm. The results of the potentiodynamic polarization studies are consistent with the results of weight loss studies.

  6. Involvement of a CCK-dependent capsaicin-sensitive afferent pathway in the inhibitory effect of pinaverium bromide on the colonic motor response to eating in rats.

    Science.gov (United States)

    Fioramonti, J; Christen, M O; Dupre, I; Bueno, L

    1997-01-01

    The effects of pinaverium bromide on the stimulation of colonic motility induced by meal and cholecystokinin (CCK) were investigated in rats chronically fitted with intraparietal electrodes on the proximal colon and previously treated or not by capsaicin. Pinaverium bromide inhibited in a dose-related manner (2-50 mg/kg, per os) the increase in colonic spike burst frequency induced by a 3 g meal or CCK-8 (2 micrograms/kg, i.v.). The CCK-A and CCK-B antagonists, devazepide and L 365260 (100 micrograms/kg, i.p.), respectively, inhibited the postprandial colonic motor response while only L 365260 reduced the CCK-induced stimulation. The effects of pinaverium bromide and CCK antagonists were not observed in capsaicin-treated animals. Moreover, CCK-8 (2 micrograms/kg, i.v.) did not stimulate colonic motility after capsaicin treatment. The inhibition of postprandial colonic motility by pinaverium bromide, given orally at therapeutic doses, involves a CCK-dependent pathway which requires the integrity of capsaicin-sensitive afferents. PMID:9243254

  7. Methyl bromide causes DNA methylation in rats and mice but fails to induce somatic mutations in λlacZ transgenic mice

    NARCIS (Netherlands)

    Pletsa, V.; Steenwinkel, M.-J.S.T.; Delft, J.H.M. van; Baan, R.A.; Kyrtopoulos, S.A.

    1998-01-01

    Following single or multiple oral treatments of rats or λlacZ transgenic mice with methyl bromide, methylated DNA adducts (N7- and/or O6-methylguanine) were found at comparable levels in various tissues, including among others the glandular stomach, the forestomach and the liver. Multiple rat treatm

  8. Palladium-phosphinous acid complexes catalyzed Suzuki cross-coupling reaction of heteroaryl bromides with phenylboronic acid in water/alcoholic solvents

    Institute of Scientific and Technical Information of China (English)

    Ben Li; Cuiping Wang; Guang Chen; Zhiqiang Zhang

    2013-01-01

    Highly active,air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl bromides under mild conditions in water/alcoholic solvents.Suzuki cross-coupling reaction of heteroaryl bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture,water/propanol mixture and neat water respectively,the corresponding yields of cross-coupling heteroaryl-aryls were satisfied.The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPdl and POPd2,and other two kinds of Pd-catalysts Pd(PPh3)4 and Pd2(dba)3.The mechanism of Suzuki cross-coupling reaction between heteroaryl bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step.Compared with other solid phase transfer catalysts,TBAB was tested as the ideal one.The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents.Notably,in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products.However in terms of the liquid phase transfer catalyst of PEGs,mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase,which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.

  9. Comparison of efficacy combination of inhaled phormoterol / budesonide turbuhaler vs. combination of nebulized salbutamol / ipratropium bromide on moderate asthma acute exacerbation in Persahabatan Hospital

    Directory of Open Access Journals (Sweden)

    Zulkarnain Barasila

    2006-03-01

    Full Text Available The aim of this study was to compare efficacy combination of phormoterol/budesonide turbuhaler vs. salbutamol/ipratropium bromide nebulization. Main therapy for acute asthma is inhaled short acting β2-agonist. Asthma patients are using two drugs, controller and reliever. Recently there is device-containing combination of long-acting β2-agonist with rapid onset and corticosteroid. This combination can act as reliever and controller. An opened randomized clinical trial of 76 patients between the ages of 12 and 60 years presenting to Persahabatan Hospital with asthma score between 8-12 participated in this study. After initial evaluation, patients were divided into two groups. Thirty-eight patients were administered combination of formoterol/budesonide 4.5/160 µg via turbuhaler (T-group every 20 minutes, total of three doses, and another 38 of salbutamol/ipratropium bromide 2.5/0.25 mg via nebulizer (N-group also with the same manner. There were no statistical difference in sex, mean age, high, weight, initial PEFR, and asthma score between two groups. The significant increased of PEFR and decreased of asthma score were observed in both groups. However, there were no significant difference of PEFR and asthma score between the two groups within every time-interval. Adverse events were mild including hoarseness, tremor and palpitation. Of T-group, 1 subject was suffered from 3 adverse events simultaneously (hoarseness, tremor and palpitation, 5 subjects were only tremor. Of N-group, all 6 subjects were only suffered from tremor. A combination of formoterol/budesonide turbuhaler and a combination of nebulized salbutamol/ipratropium bromide are clinically equivalent for treatment moderate acute asthma. However, nebulized salbutamol/ipratropium bromide had less adverse effects. (Med J Indones 2006; 15:34-42Keywords: phormoterol, budesonide, salbutamol, ipratropium bromide, acute asthma

  10. Communication: Coordination structure of bromide ions associated with hexyltrimethylammonium cations at liquid/liquid interfaces under potentiostatic control as studied by total-reflection X-ray absorption fine structure.

    Science.gov (United States)

    Nagatani, Hirohisa; Harada, Makoto; Tanida, Hajime; Sakae, Hiroki; Imura, Hisanori

    2014-03-14

    Total-reflection X-ray absorption fine structure (TR-XAFS) technique was applied for the first time to an interface between two immiscible electrolyte solutions under potentiostatic control. The hydration structure of bromide ions was investigated at polarized 2-octanone/water interfaces. TR-XAFS spectra at Br K-edge measured in the presence of hexyltrimethylammonium bromide (C6TAB) were slightly modified depending on the Galvani potential difference (Δ(o)(w)φ). The extended X-ray absorption fine structure analysis exposed hydration structure changes of bromide ions at the polarized interface. The coordination structure of bromide ions at the interface could be analyzed as compared with bromide ions dissolved in aqueous solution and Br(-)-exchanged resin having quaternary ammonium groups. The results indicated that bromide ions were associated with C6TA(+) at the polarized interface. The relative contribution of ion association form of bromide ions with quaternary ammonium groups was enhanced at a potential close to the ion transfer of C6TA(+), where the interfacial concentration of C6TA(+) is increased as a function of Δ(o)(w)φ.

  11. A sensitive electrochemical chlorophenols sensor based on nanocomposite of ZnSe quantum dots and cetyltrimethylammonium bromide

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jianjun; Li, Xiao [The College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001 (China); Yang, Ran, E-mail: yangran@zzu.edu.cn [The College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001 (China); Qu, Lingbo, E-mail: qulingbo@zzu.edu.cn [The College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001 (China); School of Chemistry and Chemical Engineering, Henan University of Technology, Zhengzhou 450001 (China); Harrington, Peter de B. [Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Clippinger Laboratories, OHIO University, Athens, OH 45701-2979 (United States)

    2013-12-04

    Graphical abstract: A very sensitive and simple electrochemical sensor for chlorophenols (CPs) based on nanocomposite of cetyltrimethylammonium bromide (CTAB) and ZnSe quantum dots (ZnSe–CTAB) through electrostatic self-assembly technology was built for the first time. The nanocomposite of ZnSe–CTAB introduced a favorable access for the electron transfer and showed excellent electrocatalytic activity for the oxidation of CPs. -- Highlights: •Nanocomposite based ZnSe QDs and CTAB was prepared and characterized. •A novel electrochemical sensor for the determination of CPs was built. •The proposed sensor was more sensitive, simple and environment-friendly. -- Abstract: In this work, a very sensitive and simple electrochemical sensor for chlorophenols (CPs) based on a nanocomposite of cetyltrimethylammonium bromide (CTAB) and ZnSe quantum dots (ZnSe–CTAB) through electrostatic self-assembly technology was built for the first time. The composite of ZnSe–CTAB introduced a favorable access for the electron transfer and gave superior electrocatalytic activity for the oxidation of CPs than ZnSe QDs and CTAB alone. Differential pulse voltammetry (DPV) was used for the quantitative determination of the CPs including 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and pentachlorophenol (PCP). Under the optimum conditions, the peak currents of the CPs were proportional to their concentrations in the range from 0.02 to 10.0 μM for 2-CP, 0.006 to 9.0 μM for 2,4-DCP, and 0.06 to 8.0 for PCP. The detection limits were 0.008 μM for 2-CP, 0.002 μM for 2,4-DCP, and 0.01 μM for PCP, respectively. The method was successfully applied for the determination of CPs in waste water with satisfactory recoveries. This ZnSe–CTAB electrode system provides operational access to design environment-friendly CPs sensors.

  12. Persistent modification of Na{sub v}1.9 following chronic exposure to insecticides and pyridostigmine bromide

    Energy Technology Data Exchange (ETDEWEB)

    Nutter, Thomas J., E-mail: tnutter@dental.ufl.edu; Cooper, Brian Y., E-mail: bcooper@dental.ufl.edu

    2014-06-15

    Many veterans of the 1991 Gulf War (GW) returned from that conflict with a widespread chronic pain affecting deep tissues. Recently, we have shown that a 60 day exposure to the insecticides permethrin, chlorpyrifos, and pyridostigmine bromide (NTPB) had little influence on nociceptor action potential forming Na{sub v}1.8, but increased K{sub v}7 mediated inhibitory currents 8 weeks after treatment. Using the same exposure regimen, we used whole cell patch methods to examine whether the influences of NTPB could be observed on Na{sub v}1.9 expressed in muscle and vascular nociceptors. During a 60 day exposure to NTPB, rats exhibited lowered muscle pain thresholds and increased rest periods, but these measures subsequently returned to normal levels. Eight and 12 weeks after treatments ceased, DRG neurons were excised from the sensory ganglia. Whole cell patch studies revealed little change in voltage dependent activation and deactivation of Na{sub v}1.9, but significant increases in the amplitude of Na{sub v}1.9 were observed 8 weeks after exposure. Cellular studies, at the 8 week delay, revealed that NTPB also significantly prolonged action potential duration and afterhyperpolarization (22 °C). Acute application of permethrin (10 μM) also increased the amplitude of Na{sub v}1.9 in skin, muscle and vascular nociceptors. In conclusion, chronic exposure to Gulf War agents produced long term changes in the amplitude of Na{sub v}1.9 expressed in muscle and vascular nociceptors. The reported increases in K{sub v}7 amplitude may have been an adaptive response to increased Na{sub v}1.9, and effectively suppressed behavioral pain measures in the post treatment period. Factors that alter the balance between Na{sub v}1.9 and K{sub v}7 could release spontaneous discharge and produce chronic deep tissue pain. - Highlights: • Rats were treated 60 days with permethrin, chlorpyrifos and pyridostigmine bromide. • 8 weeks after treatments, Nav1.9 activation and deactivation were

  13. Thermal and structural behavior of dioctadecyldimethylammonium bromide dispersions studied by differential scanning calorimetry and X-ray scattering.

    Directory of Open Access Journals (Sweden)

    Eloi Feitosa

    Full Text Available Dioctadecyldimethylammonium bromide (DODAB is a double chain cationic lipid, which assembles as bilayer structures in aqueous solution. The precise structures formed depend on, e.g., lipid concentration and temperature. We here combine differential scanning calorimetry (DSC and X-ray scattering (SAXS and WAXS to investigate the thermal and structural behavior of up to 120 mM DODAB in water within the temperature range 1-70 °C. Below 1 mM, this system is dominated by unilamellar vesicles (ULVs. Between 1 and 65 mM, ULVs and multilamellar structures (MLSs co-exist, while above 65 mM, the MLSs are the preferred structure. Depending on temperature, DSC and X-ray data show that the vesicles can be either in the subgel (SG, gel, or liquid crystalline (LC state, while the MLSs (with lattice distance d = 36.7 Å consist of interdigitated lamellae in the SG state, and ULVs in the LC state (no Bragg peak. Critical temperatures related to the thermal transitions of these bilayer structures obtained in the heating and cooling modes are reported, together with the corresponding transition enthalpies.

  14. Sensitive and selective turn-on fluorescence method for cetyltrimethylammonium bromide determination based on acridine orange-polystyrene sulfonate complex.

    Science.gov (United States)

    Li, Na; Hao, Xia; Kang, Bei Hua; Li, Nian Bing; Luo, Hong Qun

    2016-06-01

    This work proposed a rapid and novel fluorescence-sensing system using a complex of acridine orange (AO) and polystyrene sulfonate (PSS) to sensitively recognize and monitor cetyltrimethylammonium bromide (CTAB) in an aqueous medium. AO can interact with PSS and a complex is formed via electrostatic attraction and hydrophobic interaction. The fluorescence of AO is greatly quenched after the introduction of PSS. Upon its subsequent addition, CTAB can interact and form a complex with PSS because the electrostatic attraction between CTAB and PSS is much stronger than that between AO and PSS, which results in significant fluorescence recovery. Interestingly, the proposed method can be applied for the discrimination and detection of surfactants with different hydrocarbon chain lengths due to their different binding affinity toward PSS. The detection limit for CTAB is as low as 0.2 µg/mL and the linear range is from 0.5 to 3.5 µg/mL. Moreover, we applied the sensor to the successful detection of CTAB in water samples. Copyright © 2015 John Wiley & Sons, Ltd.

  15. A microcalorimetric study of {beta}-cyclodextrin with 3-alkoxyl-2-hydroxypropyl trimethyl ammonium bromides in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Sun Dezhi [Department of Chemistry, Liaocheng University, Wenhua Road, Liaocheng, Shandong 252059 (China)]. E-mail: sundezhisdz@163.com; Wang Shibing [Department of Chemistry, Liaocheng University, Wenhua Road, Liaocheng, Shandong 252059 (China); Wei Xilian [Department of Chemistry, Liaocheng University, Wenhua Road, Liaocheng, Shandong 252059 (China); Yin Baolin [Department of Chemistry, Liaocheng University, Wenhua Road, Liaocheng, Shandong 252059 (China)

    2005-05-15

    We have investigated with titration microcalorimetry {beta}-cyclodextrin with 3-alkoxyl-2-hydroxypropyl trimethyl ammonium bromides, which is a new surfactant synthesized in this laboratory, in aqueous solutions at a temperature of 298.15 K. The results are discussed in the light of amphiphilic interaction and the complex formed of water molecules around a hydrophobic surfactant tail. The stoichiometry of the (host + guest) complex changes from 1:1 to 2:1, as the number of carbon atoms n in the hydrophobic chain, C{sub n}H{sub 2n+1}O, increases from 8 to 14. All the complexes are stable with the apparent experimentally determined stability constants of {beta}{sub 1} 1.08 . 10{sup 3} dm{sup 3} . mol{sup -1}, {beta}{sub 1} = 28.66 . 10{sup 3} dm{sup 3} . mol{sup -1} and {beta}{sub 2} = 141.9 . 10{sup 3} dm{sup 6} . mol{sup -2} for n = 8, 12 and 14, respectively. The enthalpy decreases with increasing n of the hydrophobic chain.

  16. Adsorption-parallel catalytic waves of cinnamic acid in hydrogen peroxide-tetra-n-butylammonium bromide-acetate system

    Institute of Scientific and Technical Information of China (English)

    亢晓峰; 过玮; 赵川; 宋俊峰

    2000-01-01

    The mechanism of the adsorption-parallel catalytic wave of cinnamic acid (C6H5—CH = CH—COOH) in acetate buffer (pH = 4.0)-H2O2-tetra-n-butylammonium bromide (Bu4N · Br) solution was studied by the linear-sweep polarography, cyclic voltammetry and digital simulation approach. Experimental results indicate that the reduction mechanism of cinnamic acid is ECdimE’ process, in which the C = C double bond of cinnamic acid first undergoes 1 e, 1H+ reduction to produce an intermediate free radical C6H5—CH—CH2—COOH(E), then the further reduction of the free radical in 1e,1H+ addition (E’) occurs simultaneously with a dimerization reaction between two free radicals (Cdim). Bu4N · Br enhances the polarographic current of cinnamic acid and shifts the peak potential to positive direction. The enhancement action of Bu4N · Br is due to the adsorption of cinnamic acid induced by Bu4N+ species. In addition, H2O2 causes the parallel catalytic wave of cinnamic acid. The mechanism of the catalytic wave is EC’ proce

  17. Study on the enhanced fluorescent spectrum of ciprofloxacin + Al(III) + La(III) + cetyltrimethylammonium bromide system and its application

    Science.gov (United States)

    Wei, Leilei; Li, Guirong; Li, Haipeng

    2010-05-01

    The fluorescence of ciprofloxacin (CIP) in HAc-NaAc buffer solution and the presence of cetyltrimethylammonium bromide (CTMAB) enhanced visibly with adding Al(III) and La(III). This enhanced fluorescence spectra were studied, and a new co-luminescence system of CIP + Al(III) + La(III) + CTMAB was discovered. There was a linear relationship between the enhanced fluorescence intensity and the concentration of CIP in the range of 0.50-80.2 μg l -1 under the optimized condition. A novel enhanced fluorescence method for the determination of trace CIP was established by using this co-luminescence system. The detection limit of the proposed method was 0.17 μg l -1 for CIP. This method is simple, rapid and sensitive. The CIP in milk samples were analyzed by the proposed method with satisfactory results. The relative standard deviation and the recovery were in ranges of 3.21-4.34% and 97.1-100.1%, respectively. The mechanism of the co-luminescence reaction and the reasons for fluorescence enhancement has been discussed.

  18. Formation and distribution of disinfection by-products during chlorine disinfection in the presence of bromide ion

    Institute of Scientific and Technical Information of China (English)

    LI Bo; QU JiuHui; LIU HuiJuan; ZHAO Xu

    2008-01-01

    The influences of contact time and pH value on the formation and distribution of four species of triha-lomethanes and five species of haloacetic acids during chlorination in the presence of bromine were investigated. Results showed that the distribution of molar fraction of trihalomethanes varied with contact time due to the change of bromide ion concentration during chlorination. Most of the triha-lomethanes comprising bromine-containing species and the favored products of the haloacetic acids were chlorine-containing species after 24 h of chlorination. The extent of bromine incorporation in tri-halomethanes and haloacetic acids both decreased with time. The contact time also had influence on the formation rate of different species of haloacetic acids. The formation and distribution of triha-lomethanes and haloacetic acids strongly depended on the chlorination pH value. All of the triha-lomethanes species formation increased with the increase of pH value except the bromoform that had not been detected. The molar fraction of bromodichloromethane and dibromochloromethane contain-ing bromine increased with pH value while chloroform without bromine decreased. Under the pH range studied in this experiment, the predominant haloacetic acids species were trichloroacetic acid and dichloroacetic acid which all decreased with the increase of pH value and the level of TCAA was higher than that of DCAA.

  19. Theoretical and experimental study on surface tension and dynamic surface tension of aqueous lithium bromide and water with additive

    Institute of Scientific and Technical Information of China (English)

    程文龙; 陈则韶; 秋泽淳; 胡芃; 柏木孝夫

    2003-01-01

    The surface tensions of water and aqueous lithium bromide (LiBr) with 2-ethyl-1-hexa- nol (2EH) and 1-octanol were measured using Wilhelmy plate method, and the oscillation of surface tension under the open condition for LiBr solution was observed. The dynamic surface tensions of water and LiBr solution in the presence of the 2EH and 1-octanol vapor were measured in this paper. The results showed that the additives vapor could obviously affect surface tension. For water, the dynamic surface tension was also affected by the mass of the tested liquid; however, for LiBr solution, the dynamic surface tension was not related to the mass of the tested solution. According to the experimental results, the hypothesis that surface tension varies linearly with the surface excess concentration is advanced, which could overcome the limit of Gibbs equation. The equations of surface absorption and desorption are modified, the units of the adsorption coefficient and desorption coefficient are unified; the effects of the liquid and vapor of additive on the surface tension are unified; the theoretical relations of the static surface tension and dynamic surface tension with the relative contents of the liquid and vapor of additive are obtained under the combined actions of them; the theoretical equations are validated by the experiments results.

  20. Evaluation of the effect of tetraethylammonium bromide and chloride on the growth and development of terrestrial plants.

    Science.gov (United States)

    Pawłowska, Barbara; Biczak, Robert

    2016-04-01

    Quaternary ammonium salts (QAS), which also include ionic liquids, constitute a vast group of chemical compounds that are increasingly common in the commercial use. This situation may lead to the contamination of the natural environment and may constitute a potential threat to all its elements, including terrestrial higher plants. This paper presents the effect of tetraethylammonium chloride [TEA][Cl] and tetraethylammonium bromide [TEA][Br] on the growth and development of spring barley and common radish. The applied QAS were characterized with phytotoxicity dependent on the concentration of compound and characteristics of the study plants. Spring barley turned out to be highly susceptible plant to the analyzed compounds, which was confirmed by % inhibition of length of plants, root length and fresh weight of plants and by calculated values for EC50, NOEC as well as LOEC. On the contrary, a common radish revealed the resistance to QAS used in the study; although, phytotoxic symptoms were still observed when high concentrations of dry weight of soil were applied (1000, 3000 and 5000 mg/kg). The applied QAS caused oxidative stress symptoms, mainly in spring barley seedlings, which were manifested by decreased assimilation of pigments content, increased hydrogen peroxide (H2O2) and malondialdehyde (MDA) content in plant cells and with a changed activity of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). PMID:26844662

  1. Removal and degradation of β-lactam antibiotics in water using didodecyldimethylammonium bromide-modified montmorillonite organoclay.

    Science.gov (United States)

    Saitoh, Tohru; Shibayama, Takayoshi

    2016-11-01

    β-Lactam antibiotics including penicillin G, nafcillin, cefazolin, cefotaxime, and oxacilline in water were rapidly removed and degraded by using didodecyldimethylammonium bromide (DDAB)-montmorillonite (MT) organoclay. Removal of antibiotics increased with increasing the amount of organoclay added and the amount of DDAB sorbed on MT. Extents of organoclay sorption of antibiotics were represented by the binding constants to DDAB molecules and correlated to the aqueous-octanol distribution coefficients. The degradation rate of β-lactam antibiotics was found to significantly increase by the organoclay sorption. Even under the mild conditions (25°C and pH 7), penicillin G (m/z=335) nearly completely (>98%) degraded into penicilloic acid (m/z=353) missing β-lactam ring within 2h. The first-order reaction rate of the primary degradation increased with increasing in temperature. The activation energy estimated from the Arrhenius plot was 49kJmol(-1) and lower than the value (83.5kJmol(-1)) in water, strongly suggesting catalytic activity of DDAB-MT organoclay. The applicability to wastewater treatment was demonstrated by using secondary effluents of municipal sewage treatment plants and synthesized hospital wastewaters. PMID:27339949

  2. Influence of Sodium Bisulfite and Lithium Bromide Solutions on the Shape Fixation of Camel Guard Hairs in Slenderization Process

    Directory of Open Access Journals (Sweden)

    Xueliang Xiao

    2016-01-01

    Full Text Available Outstanding performance of natural camel hair has attracted much attention on the effective use of such specialty fiber to apparel textiles. In this paper, sodium bisulfide (SB and lithium bromide (LB solutions were used to process the camel guard hair before its slenderization. It is found that camel guard hair processed by SB solution shows the highest breaking elongation (~140% due to the breakage of disulfide bonds (reflected by Raman spectra. LB ions result in the disruption of hair crystalline phase with slight benefit to the slenderization (determined by X-ray diffraction and differential scanning calorimetry. IR spectra indicate that hydrogen bonds of camel guard hair act as fixation switch in the programmed tensile test. It is discovered that guard hair reveals the best water-induced shape memory with 90% of stretching shape recovery, whereas the value remained to be 70% and 60% for hair processed by LB and SB solutions after breaking partial crystalline phase and disulfide cross-links separately (polymer net-points. The poorer shape memory of processed guard hair benefits its slenderization for more stable fixation of stretched length.

  3. Structures and Magnetic Properties of Monomeric Copper(II) Bromide Complexes with a Pyridine-Containing Tridentate Schiff Base

    International Nuclear Information System (INIS)

    Two novel copper(II) bromide complexes with pyridine containing Schiff base ligands, Cu(pmed)Br2 and Cu(dpmed)Br2 where pmed = N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (pmed) and dpmed = N,N-diethyl-N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (dpmed) were synthesized and characterized using Xray single crystal structure analysis, optical and magnetic susceptibility measurements. Crystal structural analysis of Cu(pmed)Br2 showed that the copper(II) ion has a distorted square-pyramidal geometry with the trigonality index of τ = 0.35 and two intermolecular hydrogen bonds, which result in the formation of two dimensional networks in the ab plane. On the other hand, Cu(dpmed)Br2 displayed a near square-pyramidal geometry with the value of τ = 0.06. In both compounds, the NNN Schiff base and one Br atom occupy the basal plane, whereas the fifth apical position is occupied by the other Br atom at a greater Cu-Br apical distance. The reported complexes show gΠ > gΤ > 2.0023 with a dx2-y2 ground state and a penta-coordinated square pyramidal geometry. Variable temperature magnetic susceptibility measurements showed that the developed copper(II) complexes follow the Curie-Weiss law, that is there are no magnetic interactions between the copper(II) ions since the Cu--Cu distance is too far for magnetic contact

  4. Postharvest treatment of fresh fruit from California with methyl bromide for control of light brown apple moth (Lepidoptera: Tortricidae).

    Science.gov (United States)

    Walse, Spencer S; Myers, Scott W; Liu, Yong-Biao; Bellamy, David E; Obenland, David; Simmons, Greg S; Tebbets, Steve

    2013-06-01

    Methyl bromide (MB) chamber fumigations were evaluated for postharvest control of light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), in fresh fruit destined for export from California. To simulate external feeding, larvae were contained in gas-permeable cages and distributed throughout loads of peaches, plums, nectarines (all Prunus spp.), apples (Malus spp.), raspberries (Rubus spp.), or grapes (Vitis spp.). Varying the applied MB dose and the differential sorption of MB by the loads resulted in a range of exposures, expressed as concentration x time cross products (CTs) that were verified by gas-chromatographic quantification of MB in chamber headspace over the course of each fumigation. CTs > or = 60 and > or = 72 mg liter(-1) h at 10.0 +/- 0.5 and 15.6 +/- 0.5 degrees C (x +/- s, average +/- SD), respectively, yielded complete mortality of approximately 6,200 larvae at each temperature. These confirmatory fumigations corroborate E. postvittana mortality data for the first time in relation to measured MB exposures and collectively comprise the largest number of larval specimens tested to date. In addition, akinetic model of MB sorption was developed for the quarantine fumigation of fresh fruit based on the measurement of exposures and how they varied across the fumigation trials. The model describes how to manipulate the applied MB dose, the load factor, and the load geometry for different types of packaged fresh fruit so that the resultant exposure is adequate for insect control.

  5. Improving enzymatic hydrolysis of lignocellulosic substrates with pre-hydrolysates by adding cetyltrimethylammonium bromide to neutralize lignosulfonate.

    Science.gov (United States)

    Cai, Cheng; Qiu, Xueqing; Lin, Xuliang; Lou, Hongming; Pang, Yuxia; Yang, Dongjie; Chen, Siwei; Cai, Kaifan

    2016-09-01

    Two pretreatment methods to overcome recalcitrance of lignocelluloses, sulfite pretreatment (SPORL) and dilute acid (DA), were conducted to pretreat softwood masson pine and hardwood eucalyptus for enzymatic hydrolysis. In the presence of corresponding pre-hydrolysates, adding moderate cetyltrimethylammonium bromide (CTAB) could enhance the enzymatic hydrolysis of the SPORL-pretreated substrates, but had no enhancement for the DA-pretreated substrates. The results showed that sodium lignosulfonate (SL) in pre-hydrolysates and CTAB together had a strong enhancement on the enzymatic hydrolysis of lignocelluloses. The compound of commercial lignosulfonate SXSL and CTAB (SXSL-CTAB) could enhance the substrate enzymatic digestibility (SED) of SPORL-pretreated masson pine from 27.1% to 71.0%, and that of DA-pretreated eucalyptus from 37.6% to 67.9%. The mechanism that CTAB increased the adsorption of SL on lignin to form more effective steric hindrance and reduced the non-productive adsorption of cellulase on lignin by neutralizing the negative charge of SL was proposed. PMID:27343448

  6. Dynamics of cetyltrimethylammonium bromide mediated reaction of phenylsulfinylacetic acid with Cr(VI: Treatment of pseudo-phase models

    Directory of Open Access Journals (Sweden)

    Subramaniam Perumal

    2015-01-01

    The influence of cetyltrimethylammonium bromide, CTon the oxidative decarboxylation of phenylsulfinylacetic acid, PSAA and several meta- and para-substituted PSAAs by Cr(VI was investigated in 95 % H2O-5 % CH3CN medium. The rate profile displayed a peculiar trend with an initial rate increase at low [CTAB] followed by sharp rate inhibition at higher [CTAB]. The initial rate acceleration can be explained by strong binding of SO42- on the positively charged micellar surface. The specific partitioning of PSAA in micellar phase by hydrophobic interaction and the oxidizing species, HCrO3+ in aqueous phase by electrostatic repulsion accounted the rate retardation at higher [CTAB]. The Hammett plot with different substituted PSAAs showed an excellent correlation affording negative ρ value which supports the proposed mechanism involving a sulfonium cation intermediate formation. The obtained ρ value in CTmedium is found to be slightly lower than that in aqueous medium. The quantitative analysis of rate data for the inhibition shown by CTwas performed using Menger-Portnoy and Piszkiewicz pseudo-phase models. The binding constant for PSAA with micelle was evaluated from Piszkiewicz cooperative model.

  7. Aggregation behavior of 1-dodecyl-3-methylimidazolium bromide in aqueous solution: effect of ionic liquids with aromatic anions.

    Science.gov (United States)

    Gu, Yingqiu; Shi, Lijuan; Cheng, Xiyuan; Lu, Fei; Zheng, Liqiang

    2013-05-28

    The effects of ionic liquids (ILs), 1-butyl-3-methylimidazolium methylsulfonate (bmimMsa), 1-butyl-3-methylimidazolium benzenesulfonate (bmimBsa), and 1-butyl-3-methylimidazolium 2-naphthalenesulfonate (bmimNsa), on the aggregation behavior of 1-dodecyl-3-methylimidazolium bromide (C12mimBr) in aqueous solution were investigated by surface tension, dynamic light scattering measurements, and (1)H NMR spectroscopy. The ability to promote the surfactant aggregation is in the order bmimNsa > bmimBsa > bmimMsa. Nevertheless, only bmimNsa distinctly reduces both the CMC value and the surface tension at CMC. Due to the penetration of C10H7SO3(-)anions into the surfactant aggregate, bmimNsa is found to induce a phase transition from micelles to vesicles, whereas the other ILs only slightly increase the sizes of micelles. The combined effect of intermolecular interactions, such as hydrophobic effect, electrostatic attractions, and π-π stacking interactions, is supposed to be responsible for this structural transformation, in which π-π stacking plays an important role. PMID:23642150

  8. One-pot synthesis of magnetic hybrid materials based on ovoid-like carboxymethyl-cellulose/cetyltrimethylammonium-bromide templates

    International Nuclear Information System (INIS)

    A novel one-pot synthetic procedure to obtain magnetic hybrid nanostructured materials (HNM), based on magnetic spinel-metal-oxide (SMO) nanoparticles stabilized in ovoid-like carboxymethyl-cellulose (CMC)/cetyltrimethylammonium-bromide (CTAB) templates, is reported. The HNM were synthesized from the controlled hydrolysis of inorganic salts of Fe (II) and Fe (III) into aqueous dissolutions of CMC and CTAB. The synthesized HNM were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and static magnetic measurements. The experimental evidence suggests that, due to the competition between CTAB molecules and SMO nanoparticles to occupy CMC intermolecular sites nearby to its carboxylate functional groups, the size of both, SMO nanoparticles and ovoid-like CMC/CTAB templates can be tuned, varying the CTAB:SMO weight ratio. Moreover, it was found that the magnetic response of the HNM depends on the confinement degree of the SMO nanoparticles into the CMC/CTAB template. Hence, their magnetic characteristics can be adjusted controlling the size of the template, the quantity and distribution of the SMO nanoparticles within the template and their size. - Graphical abstract: Display Omitted - Highlights: • The synthesis of magnetic hybrid materials is reported. • The hybrid materials were synthesized following a novel one-pot procedure. • The magnetic nanoparticles were stabilized in ovoid-like templates. • The size of the templates was tuned adjusting nanoparticles weight content. • The magnetic properties of hybrid materials depend on the size of the template

  9. Formation potentials of bromate and brominated disinfection by-products in bromide-containing water by ozonation.

    Science.gov (United States)

    Lin, Tao; Wu, Shouke; Chen, Wei

    2014-12-01

    The ozonation involved in drinking water treatment raises issues of water quality security when the raw water contains bromide (Br(-)). Br(-) ions may be converted to bromate (BrO3 (-)) during ozonation and some brominated disinfection by-products (Br-DBPs) in the following chlorination. In this study, the effects of ozone (O3) dosage, contact time, pH, and Br(-) and ammonia (NH3-N) concentrations on the formation of BrO3 (-) and Br-DBPs have been investigated. The results show that decreasing the initial Br(-) concentration is an effective means of controlling the formation of BrO3 (-). When the concentration of Br(-) was lower than 100 μg/L, by keeping the ratio of O3 dosage to dissolved organic carbon (DOC) concentration at less than 1, BrO3 (-) production was effectively suppressed. The concentration of BrO3 (-) steadily increased with increasing O3 dosage at high Br(-) concentration (>900 μg/L). Additionally, a longer ozonation time increased the concentrations of BrO3 (-) and total organic bromine (TOBr), while it had less impact on the formation potentials of brominated trihalomethanes (Br-THMFP) and haloacetic acids (Br-HAAFP). Higher pH value and the presence of ammonia may lead to an increase in the formation potential of BrO3 (-) and Br-DBPs.

  10. Oxidative Carbonylation of Methanol to Dimethyl Carbonate Over Cu(II)-1,10-Phenanthroline Bromide Complexes☆

    Institute of Scientific and Technical Information of China (English)

    Zhiping Du⁎; Lihua Xiong; Zhikun Lin; Xuli Li; Yigang Ding; Yuanxin Wu

    2014-01-01

    In order to develop the catalysts with low corrosiveness for the oxidative carbonylation of methanol to dimethyl carbonate (DMC), CuBr2 was selected as the metal source to prepare Cu coordination compounds, Cu(phen)Br2, [Cu(phen)2Br]Br and [Cu(phen)3]Br2 (phen=1,10-phenanthroline). These complexes were characterized by thermogravimetric analysis and temperature-programmed reduction. Their catalytic performances were investigated. It was found that the metal coordination environments and thermal stability of the complexes played an important role in their catalytic activities. Cu(phen)Br2 exhibited the highest activity due to the lowest steric hindrance, the most positions occupied by the bromide ions and the highest thermal stability. The turnover number was up to 47.6 DMC mol·(Cu mol)−1 with selectivity of 92.8%under conditions of 120 °C, ratio of partial pressure of CO to O2 of 19:1 (below the explosion limit of CO) and catalyst concentration of 0.011 mol·L−1. Furthermore, a plausible reaction mechanism was suggested on the basis of the experimental data.

  11. Thermodynamic and elastic fluctuation analysis of Langmuir mixed monolayers composed by dehydrocholic acid (HDHC) and didodecyldimethylammonium bromide (DDAB).

    Science.gov (United States)

    Messina, Paula V; Prieto, Gerardo; Ruso, Juan Manuel; Fernández-Leyes, Marcos D; Schulz, Pablo C; Sarmiento, Félix

    2010-01-01

    The physicochemical and elastic properties of Langmuir mixed monolayers composed by dehydrocholic acid (HDHC) and didodecyldimethylammonium bromide (DDAB) were evaluated. The experiments were performed with a constant surface pressure penetration Langmuir balance based on Axisymmetric Drop Shape Analysis (ADSA). The behavior of such amphiphiles in monolayer was clearly non-ideal and would be seriously influenced by the amount of HDHC molecules present. The presence of bile acid type molecules caused the monolayer be more condensed (A(c) diminution) and the intermolecular attractive interactions be stronger (high epsilon(0) values). This fact would be related to H-bond formation between water and carboxilate and carbonile groups in the cholesteric ring and agreed with the existence of laterally structured microdomains at the monolayer (determined by the analysis of the first virial coefficient, b(0)35 mJ m(-2)) just with the obtained negative values of the free energy of mixing Delta G(mix), and the excess second virial coefficient (b(1))(E) obtained allows us to infer that net attractive interaction existed between HDHC and DDAB molecules at the monolayer and that mixed systems would be able to be used in the formulation of supramolecular assemblies.

  12. NIR photoluminescence of bismuth-doped CsCdBr{sub 3} – The first ternary bromide phase with a univalent bismuth impurity center

    Energy Technology Data Exchange (ETDEWEB)

    Romanov, Alexey N., E-mail: alexey.romanov@list.ru [N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119991 (Russian Federation); Veber, Alexander A. [Universität Erlangen-Nürnberg, Lehrstuhl für Glas und Keramik, Martensstraße 5, 91058 Erlangen (Germany); Vtyurina, Daria N. [N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119991 (Russian Federation); Kouznetsov, Mikhail S.; Zaramenskikh, Ksenia S.; Lisitsky, Igor S. [State Scientific-Research and Design Institute of Rare-Metal Industry “Giredmet” JSC, 5-1 B.Tolmachevsky Lane, 119017 Moscow (Russian Federation); Fattakhova, Zukhra T.; Haula, Elena V. [N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119991 (Russian Federation); Loiko, Pavel A.; Yumashev, Konstantin V. [Center for Optical Materials and Technologies, Belarusian National Technical University, 65/17 Nezavisimosti Avenue, 220013 Minsk (Belarus); Korchak, Vladimir N. [N.N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 4 Kosygina Street, 119991 (Russian Federation)

    2015-11-15

    Single crystals of ternary bromide phase CsCdBr{sub 3} doped with univalent bismuth cations are prepared for the first time by the Bridgman method. Bi{sup +} impurity center emits a broadband long-lived near-infrared photoluminescence with a maximum at ~1053 nm. The characteristics of this photoluminescence and its relations with the energy spectrum of Bi{sup +} impurity center are discussed. A comparison of Bi{sup +} photoluminescence in CsCdBr{sub 3} and ternary chlorides (studied previously) is performed. - Highlights: • Single crystals of Bi{sup +}-doped ternary bromide CsCdBr{sub 3} were prepared. • Broadband NIR photoluminescence was observed from Bi{sup +}-doped CsCdBr{sub 3}. • Single optical center is responsible for NIR emission in Bi{sup +}-doped CsCdBr{sub 3}.

  13. Niobium(v) chloride and imidazolium bromides as efficient dual catalyst systems for the cycloaddition of carbon dioxide and propylene oxide

    KAUST Repository

    Wilhelm, Michael E.

    2014-02-19

    The application of niobium(v) chloride and several imidazolium bromides as catalyst systems for the cycloaddition of propylene oxide (PO) with carbon dioxide to propylene carbonate (PC) is reported. A set of 31 different imidazolium bromides has been synthesized with varying substituents at all five imidazolium ring atoms, of which 17 have not been reported before. The impact of different substitution patterns (steric and electronic changes and solubility in PO) at the imidazolium ring on the catalytic activity was investigated. The optimisation of the catalyst structure allows for the valorisation of carbon dioxide under mild reaction conditions with high reaction rates in very good yield and selectivity for PC. This journal is © the Partner Organisations 2014.

  14. Initial test results from the RedFlow 5 kW, 10 kWh zinc-bromide module, phase 1.

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Summer Rhodes; Rose, David Martin

    2012-02-01

    In this paper the performance results of the RedFlow zinc-bromide module (ZBM) Gen 2.0 are reported for Phase 1 of testing, which includes initial characterization of the module. This included physical measurement, efficiency as a function of charge and discharge rates, efficiency as a function of maximum charge capacity, duration of maximum power supplied, and limited cycling with skipped strip cycles. The goal of this first phase of testing was to verify manufacturer specifications of the zinc-bromide flow battery. Initial characterization tests have shown that the ZBM meets the manufacturer's specifications. Further testing, including testing as a function of temperature and life cycle testing, will be carried out during Phase 2 of the testing, and these results will be issued in the final report, after Phase 2 testing has concluded.

  15. A chemical probe technique for the determination of reactive halogen species in aqueous solution: Part 2 – chloride solutions and mixed bromide/chloride solutions

    Directory of Open Access Journals (Sweden)

    C. Anastasio

    2006-02-01

    Full Text Available Although reactive halogen species (X*=X●, ●X2−, X2 and HOX, where X=Br, Cl, or I are important environmental oxidants, relatively little is known about their kinetics in condensed phases such as seawater and sea-salt particles. Here we describe a new technique to determine reactive chlorine and bromine species in aqueous solutions by using allyl alcohol (CH2=CHCH2OH as a chemical probe. This probe is combined with competition kinetics in order to determine steady state concentrations of X*(aq. In some cases the technique also can be used to determine the rates of formation and lifetimes of X* in aqueous solution. In a companion paper we reported the results of our method development for aqueous solutions containing only bromide (Br−. In this paper, we discuss method development for solutions containing chloride (Cl− alone, and for solutions containing both bromide and chloride.

  16. Niobium(v) chloride and imidazolium bromides as efficient dual catalyst systems for the cycloaddition of carbon dioxide and propylene oxide

    KAUST Repository

    Wilhelm, Michael E.

    2014-01-01

    The application of niobium(v) chloride and several imidazolium bromides as catalyst systems for the cycloaddition of propylene oxide (PO) with carbon dioxide to propylene carbonate (PC) is reported. A set of 31 different imidazolium bromides has been synthesized with varying substituents at all five imidazolium ring atoms, of which 17 have not been reported before. The impact of different substitution patterns (steric and electronic changes and solubility in PO) at the imidazolium ring on the catalytic activity was investigated. The optimisation of the catalyst structure allows for the valorisation of carbon dioxide under mild reaction conditions with high reaction rates in very good yield and selectivity for PC. This journal is © the Partner Organisations 2014.

  17. Behaviour of a binary solvent mixture constituted by an amphiphilic ionic liquid, 1-decyl-3-methylimidazolium bromide and water Potentiometric and conductimetric studies.

    Science.gov (United States)

    Sirieix-Plénet, Juliette; Gaillon, Laurent; Letellier, Pierre

    2004-07-01

    We investigated the properties of 1-decyl-3-methylimidazolium bromide (DMImBr), a molten salt at room temperature, and its mixtures with water in the whole proportions. At low concentrations, this salt behaved like a classical cationic amphiphile. Its critical micellar concentration (cmc) was determined by conductimetry and by measuring electromotive forces (EMF) with bromide or cationic surfactant-selective electrodes. Moreover, the association rate of the counter ion to micelle has been determined on a wide range of concentrations, allowing characterising the micellisation equilibrium by a solubility product. The conductivity of this liquid electrolyte in mixtures with water was maximal at high concentrations. We modelled this behaviour, taking into account the molar volume fraction of both phases. Our results show that these solutions, which are composed of dispersed aggregates, behave like mixtures of two phases that interpenetrate themselves.

  18. A Sustainable Synthesis of 2-Benzoxazyl and 2-Benzothiazyl Ketones from Alkynyl Bromides and 2-Amino(thio)phenols Promoted by a Recyclable Catalytic System

    Institute of Scientific and Technical Information of China (English)

    崔良艳; 何艳; 范学森

    2012-01-01

    An environmentally and economically sustainable synthesis of 2-benzoxazyl ketones and 2-benzothiazyl ke- tones through FeC13·6H2O catalyzed tandem reactions of alkynyl bromides with 2-amino(thio)phenols in [bmim]BF4 has been developed. Remarkable advantages of this new synthetic strategy include high efficiency, readily available starting materials, and recyclable catalyst and reaction medium.

  19. Extraction and Chromatographic Determination of Shikimic Acid in Chinese Conifer Needles with 1-Benzyl-3-methylimidazolium Bromide Ionic Liquid Aqueous Solutions

    OpenAIRE

    2014-01-01

    An ionic liquids-based ultrasound-assisted extraction (ILUAE) method was successfully developed for extracting shikimic acid from conifer needles. Eleven 1-alkyl-3-methylimidazolium ionic liquids with different cations and anions were investigated and 1-benzyl-3-methylimidazolium bromide solution was selected as the solvent. The conditions for ILUAE, including the ionic liquid concentration, ultrasound power, ultrasound time, and liquid-solid ratio, were optimized. The proposed method had goo...

  20. RNA extraction from various recalcitrant plant tissues with a cethyltrimethylammonium bromide-containing buffer followed by an acid guanidium thiocyanate-phenol-chloroform treatment.

    Science.gov (United States)

    Suzuki, Yuji; Mae, Tadahiko; Makino, Amane

    2008-07-01

    High-quality total RNA was extracted using a cethyltrimethylammonium bromide-containing buffer followed by an acid guanidium thiocyanate-phenol-chloroform treatment from recalcitrant plant tissues such as tree leaves (pine, Norway spruce, ginkgo, Japanese cedar, rose), flowers (rose, Lotus japonicus) and storage tissues (seeds of Lotus japonicus and rice, sweet potato tuber, banana fruit). This protocol greatly reduced the time required for RNA extraction.